25 files changed, 22690 insertions, 0 deletions

diff --git a/libmount/src/Makemodule.am b/libmount/src/Makemodule.am
new file mode 100644
index 0000000..eaa69c1
--- /dev/null
+++ b/libmount/src/Makemodule.am
@@ -0,0 +1,176 @@
+
+# libmount.h is generated, so it's store in builddir!
+mountincdir = $(includedir)/libmount
+nodist_mountinc_HEADERS = libmount/src/libmount.h
+
+usrlib_exec_LTLIBRARIES += libmount.la
+libmount_la_SOURCES = \
+	include/list.h \
+	lib/monotonic.c \
+	\
+	libmount/src/mountP.h \
+	libmount/src/cache.c \
+	libmount/src/fs.c \
+	libmount/src/init.c \
+	libmount/src/iter.c \
+	libmount/src/lock.c \
+	libmount/src/optmap.c \
+	libmount/src/optstr.c \
+	libmount/src/tab.c \
+	libmount/src/tab_diff.c \
+	libmount/src/tab_parse.c \
+	libmount/src/tab_update.c \
+	libmount/src/test.c \
+	libmount/src/utils.c \
+	libmount/src/version.c
+
+if LINUX
+libmount_la_SOURCES += \
+	libmount/src/context.c \
+	libmount/src/context_loopdev.c \
+	libmount/src/context_veritydev.c \
+	libmount/src/context_mount.c \
+	libmount/src/context_umount.c \
+	libmount/src/monitor.c
+
+if HAVE_BTRFS
+libmount_la_SOURCES += libmount/src/btrfs.c
+endif
+
+endif # LINUX
+
+
+libmount_la_LIBADD = \
+	libcommon.la \
+	libblkid.la \
+	$(SELINUX_LIBS) \
+	$(REALTIME_LIBS)
+
+if HAVE_CRYPTSETUP
+if CRYPTSETUP_VIA_DLOPEN
+libmount_la_LIBADD += -ldl
+else
+libmount_la_LIBADD += $(CRYPTSETUP_LIBS)
+endif
+endif
+
+libmount_la_CFLAGS = \
+	$(AM_CFLAGS) \
+	$(SOLIB_CFLAGS) \
+	$(CRYPTSETUP_CFLAGS) \
+	-I$(ul_libblkid_incdir) \
+	-I$(ul_libmount_incdir) \
+	-I$(top_srcdir)/libmount/src
+
+EXTRA_libmount_la_DEPENDENCIES = \
+	libmount/src/libmount.sym
+
+libmount_la_LDFLAGS = $(SOLIB_LDFLAGS)
+if HAVE_VSCRIPT
+libmount_la_LDFLAGS += $(VSCRIPT_LDFLAGS),$(top_srcdir)/libmount/src/libmount.sym
+endif
+libmount_la_LDFLAGS += -version-info $(LIBMOUNT_VERSION_INFO)
+
+
+EXTRA_DIST += \
+	libmount/src/libmount.sym
+
+if BUILD_LIBMOUNT_TESTS
+check_PROGRAMS += \
+	test_mount_cache \
+	test_mount_lock \
+	test_mount_optstr \
+	test_mount_tab \
+	test_mount_tab_diff \
+	test_mount_tab_update \
+	test_mount_utils \
+	test_mount_version \
+	test_mount_debug
+if LINUX
+check_PROGRAMS += test_mount_context
+check_PROGRAMS += test_mount_monitor
+endif
+
+libmount_tests_cflags  = -DTEST_PROGRAM $(libmount_la_CFLAGS) $(NO_UNUSED_WARN_CFLAGS)
+libmount_tests_ldflags = libblkid.la -static
+libmount_tests_ldadd   = libmount.la $(LDADD) $(REALTIME_LIBS)
+
+if HAVE_SELINUX
+libmount_tests_ldadd += $(SELINUX_LIBS)
+endif
+
+test_mount_cache_SOURCES = libmount/src/cache.c
+test_mount_cache_CFLAGS = $(libmount_tests_cflags)
+test_mount_cache_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_cache_LDADD = $(libmount_tests_ldadd)
+
+test_mount_context_SOURCES = libmount/src/context.c
+test_mount_context_CFLAGS = $(libmount_tests_cflags)
+test_mount_context_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_context_LDADD = $(libmount_tests_ldadd)
+
+test_mount_lock_SOURCES = libmount/src/lock.c
+test_mount_lock_CFLAGS = $(libmount_tests_cflags)
+test_mount_lock_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_lock_LDADD = $(libmount_tests_ldadd)
+
+test_mount_optstr_SOURCES = libmount/src/optstr.c
+test_mount_optstr_CFLAGS = $(libmount_tests_cflags)
+test_mount_optstr_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_optstr_LDADD = $(libmount_tests_ldadd)
+
+test_mount_tab_SOURCES = libmount/src/tab.c
+test_mount_tab_CFLAGS = $(libmount_tests_cflags)
+test_mount_tab_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_tab_LDADD = $(libmount_tests_ldadd)
+
+test_mount_tab_diff_SOURCES = libmount/src/tab_diff.c
+test_mount_tab_diff_CFLAGS = $(libmount_tests_cflags)
+test_mount_tab_diff_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_tab_diff_LDADD = $(libmount_tests_ldadd)
+
+test_mount_monitor_SOURCES = libmount/src/monitor.c
+test_mount_monitor_CFLAGS = $(libmount_tests_cflags)
+test_mount_monitor_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_monitor_LDADD = $(libmount_tests_ldadd)
+
+test_mount_tab_update_SOURCES = libmount/src/tab_update.c
+test_mount_tab_update_CFLAGS = $(libmount_tests_cflags)
+test_mount_tab_update_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_tab_update_LDADD = $(libmount_tests_ldadd)
+
+test_mount_utils_SOURCES = libmount/src/utils.c
+test_mount_utils_CFLAGS = $(libmount_tests_cflags)
+test_mount_utils_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_utils_LDADD = $(libmount_tests_ldadd)
+
+test_mount_version_SOURCES = libmount/src/version.c
+test_mount_version_CFLAGS = $(libmount_tests_cflags)
+test_mount_version_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_version_LDADD = $(libmount_tests_ldadd)
+
+test_mount_debug_SOURCES = libmount/src/init.c
+test_mount_debug_CFLAGS = $(libmount_tests_cflags)
+test_mount_debug_LDFLAGS = $(libmount_tests_ldflags)
+test_mount_debug_LDADD = $(libmount_tests_ldadd)
+
+endif # BUILD_LIBMOUNT_TESTS
+
+
+# move lib from $(usrlib_execdir) to $(libdir) if needed
+install-exec-hook-libmount:
+	if test "$(usrlib_execdir)" != "$(libdir)" -a -f "$(DESTDIR)$(usrlib_execdir)/libmount.so"; then \
+		$(MKDIR_P) $(DESTDIR)$(libdir); \
+		mv $(DESTDIR)$(usrlib_execdir)/libmount.so.* $(DESTDIR)$(libdir); \
+		so_img_name=$$(readlink $(DESTDIR)$(usrlib_execdir)/libmount.so); \
+		so_img_rel_target=$$(echo $(usrlib_execdir) | sed 's,\(^/\|\)[^/][^/]*,..,g'); \
+		(cd $(DESTDIR)$(usrlib_execdir) && \
+			rm -f libmount.so && \
+			$(LN_S) $$so_img_rel_target$(libdir)/$$so_img_name libmount.so); \
+	fi
+
+uninstall-hook-libmount:
+	rm -f $(DESTDIR)$(libdir)/libmount.so*
+
+INSTALL_EXEC_HOOKS += install-exec-hook-libmount
+UNINSTALL_HOOKS += uninstall-hook-libmount
diff --git a/libmount/src/btrfs.c b/libmount/src/btrfs.c
new file mode 100644
index 0000000..a831ce8
--- /dev/null
+++ b/libmount/src/btrfs.c
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2016 David Sterba <dsterba@suse.cz>
+ * Copyright (C) 2016 Stanislav Brabec <sbrabec@suse.cz>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * Based on kernel ctree.h, rbtree.h and btrfs-progs.
+ */
+#include <dirent.h>
+#include <sys/ioctl.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <linux/btrfs.h>
+
+#include "mountP.h"
+#include "bitops.h"
+
+
+/* linux/btrfs.h lacks large parts of stuff needed for getting default
+ * sub-volume. Suppose that if BTRFS_DIR_ITEM_KEY is not defined, all
+ * declarations are still missing.
+ */
+#ifndef BTRFS_DIR_ITEM_KEY
+
+/*
+ * dir items are the name -> inode pointers in a directory.  There is one
+ * for every name in a directory.
+ */
+#define BTRFS_DIR_ITEM_KEY	84
+
+/* holds pointers to all of the tree roots */
+#define BTRFS_ROOT_TREE_OBJECTID 1ULL
+
+/* directory objectid inside the root tree */
+#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
+
+/*
+ * the key defines the order in the tree, and so it also defines (optimal)
+ * block layout.  objectid corresponds with the inode number.  The flags
+ * tells us things about the object, and is a kind of stream selector.
+ * so for a given inode, keys with flags of 1 might refer to the inode
+ * data, flags of 2 may point to file data in the btree and flags == 3
+ * may point to extents.
+ *
+ * offset is the starting byte offset for this key in the stream.
+ *
+ * btrfs_disk_key is in disk byte order.  struct btrfs_key is always
+ * in cpu native order.  Otherwise they are identical and their sizes
+ * should be the same (ie both packed)
+ */
+struct btrfs_disk_key {
+	uint64_t objectid; /* little endian */
+	uint8_t type;
+	uint64_t offset; /* little endian */
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_item {
+	struct btrfs_disk_key location;
+	uint64_t transid; /* little endian */
+	uint16_t data_len; /* little endian */
+	uint16_t name_len; /* little endian */
+	uint8_t type;
+} __attribute__ ((__packed__));
+
+#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)		\
+static inline uint##bits##_t btrfs_##name(const type *s)		\
+{									\
+	return le##bits##_to_cpu(s->member);				\
+}
+
+/* struct btrfs_disk_key */
+BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
+			 objectid, 64)
+
+BTRFS_SETGET_STACK_FUNCS(stack_dir_name_len, struct btrfs_dir_item, name_len, 16)
+
+/*
+  Red Black Trees
+*/
+struct rb_node {
+	unsigned long  __rb_parent_color;
+	struct rb_node *rb_right;
+	struct rb_node *rb_left;
+} __attribute__((aligned(sizeof(long))));
+    /* The alignment might seem pointless, but allegedly CRIS needs it */
+
+#endif /* BTRFS_DIR_ITEM_KEY */
+
+/*
+ * btrfs_get_default_subvol_id:
+ * @path: Path to mounted btrfs volume
+ *
+ * Searches for the btrfs default subvolume id.
+ *
+ * Returns: default subvolume id or UINT64_MAX (-1) in case of no
+ * default subvolume or error. In case of error, errno is set
+ * properly.
+ */
+uint64_t btrfs_get_default_subvol_id(const char *path)
+{
+	int iocret;
+	int fd;
+	DIR *dirstream;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	uint64_t found = UINT64_MAX;
+
+	dirstream = opendir(path);
+	if (!dirstream) {
+		DBG(BTRFS, ul_debug("opendir() failed for \"%s\" [errno=%d %m]", path, errno));
+		return UINT64_MAX;
+	}
+	fd = dirfd(dirstream);
+	if (fd < 0) {
+		DBG(BTRFS, ul_debug("dirfd(opendir()) failed for \"%s\" [errno=%d %m]", path, errno));
+		goto out;
+	}
+
+	memset(&args, 0, sizeof(args));
+	sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+	sk->min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
+	sk->max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
+	sk->min_type = BTRFS_DIR_ITEM_KEY;
+	sk->max_type = BTRFS_DIR_ITEM_KEY;
+	sk->max_offset = UINT64_MAX;
+	sk->max_transid = UINT64_MAX;
+	sk->nr_items = 1;
+
+	iocret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+	if (iocret < 0) {
+		DBG(BTRFS, ul_debug("ioctl() failed for \"%s\" [errno=%d %m]", path, errno));
+		goto out;
+	}
+
+	/* the ioctl returns the number of items it found in nr_items */
+	if (sk->nr_items == 0) {
+		DBG(BTRFS, ul_debug("root tree dir object id not found"));
+		goto out;
+	}
+	DBG(BTRFS, ul_debug("found %d root tree dir object id items", sk->nr_items));
+
+	sh = (struct btrfs_ioctl_search_header *)args.buf;
+
+	if (sh->type == BTRFS_DIR_ITEM_KEY) {
+		struct btrfs_dir_item *di;
+		int name_len;
+		char *name;
+
+		di = (struct btrfs_dir_item *)(sh + 1);
+		name_len = btrfs_stack_dir_name_len(di);
+		name = (char *)(di + 1);
+
+		if (!strncmp("default", name, name_len)) {
+			found = btrfs_disk_key_objectid(&di->location);
+			DBG(BTRFS, ul_debug("\"default\" id is %llu", (unsigned long long)found));
+		} else {
+			DBG(BTRFS, ul_debug("\"default\" id not found in tree root"));
+			goto out;
+		}
+	} else {
+		DBG(BTRFS, ul_debug("unexpected type found: %d", (int)sh->type));
+		goto out;
+	}
+
+out:
+	closedir(dirstream);
+	return found;
+}
diff --git a/libmount/src/cache.c b/libmount/src/cache.c
new file mode 100644
index 0000000..2fafdd0
--- /dev/null
+++ b/libmount/src/cache.c
@@ -0,0 +1,840 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: cache
+ * @title: Cache
+ * @short_description: paths and tags (UUID/LABEL) caching
+ *
+ * The cache is a very simple API for working with tags (LABEL, UUID, ...) and
+ * paths. The cache uses libblkid as a backend for TAGs resolution.
+ *
+ * All returned paths are always canonicalized.
+ */
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <blkid.h>
+
+#include "canonicalize.h"
+#include "mountP.h"
+#include "loopdev.h"
+#include "strutils.h"
+
+/*
+ * Canonicalized (resolved) paths & tags cache
+ */
+#define MNT_CACHE_CHUNKSZ	128
+
+#define MNT_CACHE_ISTAG		(1 << 1) /* entry is TAG */
+#define MNT_CACHE_ISPATH	(1 << 2) /* entry is path */
+#define MNT_CACHE_TAGREAD	(1 << 3) /* tag read by mnt_cache_read_tags() */
+
+/* path cache entry */
+struct mnt_cache_entry {
+	char			*key;	/* search key (e.g. uncanonicalized path) */
+	char			*value;	/* value (e.g. canonicalized path) */
+	int			flag;
+};
+
+struct libmnt_cache {
+	struct mnt_cache_entry	*ents;
+	size_t			nents;
+	size_t			nallocs;
+	int			refcount;
+
+	/* blkid_evaluate_tag() works in two ways:
+	 *
+	 * 1/ all tags are evaluated by udev /dev/disk/by-* symlinks,
+	 *    then the blkid_cache is NULL.
+	 *
+	 * 2/ all tags are read from blkid.tab and verified by /dev
+	 *    scanning, then the blkid_cache is not NULL and then it's
+	 *    better to reuse the blkid_cache.
+	 */
+	blkid_cache		bc;
+
+	struct libmnt_table	*mtab;
+};
+
+/**
+ * mnt_new_cache:
+ *
+ * Returns: new struct libmnt_cache instance or NULL in case of ENOMEM error.
+ */
+struct libmnt_cache *mnt_new_cache(void)
+{
+	struct libmnt_cache *cache = calloc(1, sizeof(*cache));
+	if (!cache)
+		return NULL;
+	DBG(CACHE, ul_debugobj(cache, "alloc"));
+	cache->refcount = 1;
+	return cache;
+}
+
+/**
+ * mnt_free_cache:
+ * @cache: pointer to struct libmnt_cache instance
+ *
+ * Deallocates the cache. This function does not care about reference count. Don't
+ * use this function directly -- it's better to use mnt_unref_cache().
+ */
+void mnt_free_cache(struct libmnt_cache *cache)
+{
+	size_t i;
+
+	if (!cache)
+		return;
+
+	DBG(CACHE, ul_debugobj(cache, "free [refcount=%d]", cache->refcount));
+
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (e->value != e->key)
+			free(e->value);
+		free(e->key);
+	}
+	free(cache->ents);
+	if (cache->bc)
+		blkid_put_cache(cache->bc);
+	free(cache);
+}
+
+/**
+ * mnt_ref_cache:
+ * @cache: cache pointer
+ *
+ * Increments reference counter.
+ */
+void mnt_ref_cache(struct libmnt_cache *cache)
+{
+	if (cache) {
+		cache->refcount++;
+		/*DBG(CACHE, ul_debugobj(cache, "ref=%d", cache->refcount));*/
+	}
+}
+
+/**
+ * mnt_unref_cache:
+ * @cache: cache pointer
+ *
+ * De-increments reference counter, on zero the cache is automatically
+ * deallocated by mnt_free_cache().
+ */
+void mnt_unref_cache(struct libmnt_cache *cache)
+{
+	if (cache) {
+		cache->refcount--;
+		/*DBG(CACHE, ul_debugobj(cache, "unref=%d", cache->refcount));*/
+		if (cache->refcount <= 0) {
+			mnt_unref_table(cache->mtab);
+
+			mnt_free_cache(cache);
+		}
+	}
+}
+
+/**
+ * mnt_cache_set_targets:
+ * @cache: cache pointer
+ * @mtab: table with already canonicalized mountpoints
+ *
+ * Add to @cache reference to @mtab. This can be used to avoid unnecessary paths
+ * canonicalization in mnt_resolve_target().
+ *
+ * Returns: negative number in case of error, or 0 o success.
+ */
+int mnt_cache_set_targets(struct libmnt_cache *cache,
+				struct libmnt_table *mtab)
+{
+	if (!cache)
+		return -EINVAL;
+
+	mnt_ref_table(mtab);
+	mnt_unref_table(cache->mtab);
+	cache->mtab = mtab;
+	return 0;
+}
+
+
+/* note that the @key could be the same pointer as @value */
+static int cache_add_entry(struct libmnt_cache *cache, char *key,
+					char *value, int flag)
+{
+	struct mnt_cache_entry *e;
+
+	assert(cache);
+	assert(value);
+	assert(key);
+
+	if (cache->nents == cache->nallocs) {
+		size_t sz = cache->nallocs + MNT_CACHE_CHUNKSZ;
+
+		e = realloc(cache->ents, sz * sizeof(struct mnt_cache_entry));
+		if (!e)
+			return -ENOMEM;
+		cache->ents = e;
+		cache->nallocs = sz;
+	}
+
+	e = &cache->ents[cache->nents];
+	e->key = key;
+	e->value = value;
+	e->flag = flag;
+	cache->nents++;
+
+	DBG(CACHE, ul_debugobj(cache, "add entry [%2zd] (%s): %s: %s",
+			cache->nents,
+			(flag & MNT_CACHE_ISPATH) ? "path" : "tag",
+			value, key));
+	return 0;
+}
+
+/* add tag to the cache, @devname has to be an allocated string */
+static int cache_add_tag(struct libmnt_cache *cache, const char *tagname,
+				const char *tagval, char *devname, int flag)
+{
+	size_t tksz, vlsz;
+	char *key;
+	int rc;
+
+	assert(cache);
+	assert(devname);
+	assert(tagname);
+	assert(tagval);
+
+	/* add into cache -- cache format for TAGs is
+	 *	key    = "TAG_NAME\0TAG_VALUE\0"
+	 *	value  = "/dev/foo"
+	 */
+	tksz = strlen(tagname);
+	vlsz = strlen(tagval);
+
+	key = malloc(tksz + vlsz + 2);
+	if (!key)
+		return -ENOMEM;
+
+	memcpy(key, tagname, tksz + 1);	   /* include '\0' */
+	memcpy(key + tksz + 1, tagval, vlsz + 1);
+
+	rc = cache_add_entry(cache, key, devname, flag | MNT_CACHE_ISTAG);
+	if (!rc)
+		return 0;
+
+	free(key);
+	return rc;
+}
+
+
+/*
+ * Returns cached canonicalized path or NULL.
+ */
+static const char *cache_find_path(struct libmnt_cache *cache, const char *path)
+{
+	size_t i;
+
+	if (!cache || !path)
+		return NULL;
+
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (!(e->flag & MNT_CACHE_ISPATH))
+			continue;
+		if (streq_paths(path, e->key))
+			return e->value;
+	}
+	return NULL;
+}
+
+/*
+ * Returns cached path or NULL.
+ */
+static const char *cache_find_tag(struct libmnt_cache *cache,
+			const char *token, const char *value)
+{
+	size_t i;
+	size_t tksz;
+
+	if (!cache || !token || !value)
+		return NULL;
+
+	tksz = strlen(token);
+
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (!(e->flag & MNT_CACHE_ISTAG))
+			continue;
+		if (strcmp(token, e->key) == 0 &&
+		    strcmp(value, e->key + tksz + 1) == 0)
+			return e->value;
+	}
+	return NULL;
+}
+
+static char *cache_find_tag_value(struct libmnt_cache *cache,
+			const char *devname, const char *token)
+{
+	size_t i;
+
+	assert(cache);
+	assert(devname);
+	assert(token);
+
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (!(e->flag & MNT_CACHE_ISTAG))
+			continue;
+		if (strcmp(e->value, devname) == 0 &&	/* dev name */
+		    strcmp(token, e->key) == 0)	/* tag name */
+			return e->key + strlen(token) + 1;	/* tag value */
+	}
+
+	return NULL;
+}
+
+/**
+ * mnt_cache_read_tags
+ * @cache: pointer to struct libmnt_cache instance
+ * @devname: path device
+ *
+ * Reads @devname LABEL and UUID to the @cache.
+ *
+ * Returns: 0 if at least one tag was added, 1 if no tag was added or
+ *          negative number in case of error.
+ */
+int mnt_cache_read_tags(struct libmnt_cache *cache, const char *devname)
+{
+	blkid_probe pr;
+	size_t i, ntags = 0;
+	int rc;
+	const char *tags[] = { "LABEL", "UUID", "TYPE", "PARTUUID", "PARTLABEL" };
+	const char *blktags[] = { "LABEL", "UUID", "TYPE", "PART_ENTRY_UUID", "PART_ENTRY_NAME" };
+
+	if (!cache || !devname)
+		return -EINVAL;
+
+	DBG(CACHE, ul_debugobj(cache, "tags for %s requested", devname));
+
+	/* check if device is already cached */
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (!(e->flag & MNT_CACHE_TAGREAD))
+			continue;
+		if (strcmp(e->value, devname) == 0)
+			/* tags have already been read */
+			return 0;
+	}
+
+	pr =  blkid_new_probe_from_filename(devname);
+	if (!pr)
+		return -1;
+
+	blkid_probe_enable_superblocks(pr, 1);
+	blkid_probe_set_superblocks_flags(pr,
+			BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
+			BLKID_SUBLKS_TYPE);
+
+	blkid_probe_enable_partitions(pr, 1);
+	blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS);
+
+	rc = blkid_do_safeprobe(pr);
+	if (rc)
+		goto error;
+
+	DBG(CACHE, ul_debugobj(cache, "reading tags for: %s", devname));
+
+	for (i = 0; i < ARRAY_SIZE(tags); i++) {
+		const char *data;
+		char *dev;
+
+		if (cache_find_tag_value(cache, devname, tags[i])) {
+			DBG(CACHE, ul_debugobj(cache,
+					"\ntag %s already cached", tags[i]));
+			continue;
+		}
+		if (blkid_probe_lookup_value(pr, blktags[i], &data, NULL))
+			continue;
+		dev = strdup(devname);
+		if (!dev)
+			goto error;
+		if (cache_add_tag(cache, tags[i], data, dev,
+					MNT_CACHE_TAGREAD)) {
+			free(dev);
+			goto error;
+		}
+		ntags++;
+	}
+
+	DBG(CACHE, ul_debugobj(cache, "\tread %zd tags", ntags));
+	blkid_free_probe(pr);
+	return ntags ? 0 : 1;
+error:
+	blkid_free_probe(pr);
+	return rc < 0 ? rc : -1;
+}
+
+/**
+ * mnt_cache_device_has_tag:
+ * @cache: paths cache
+ * @devname: path to the device
+ * @token: tag name (e.g "LABEL")
+ * @value: tag value
+ *
+ * Look up @cache to check if @tag+@value are associated with @devname.
+ *
+ * Returns: 1 on success or 0.
+ */
+int mnt_cache_device_has_tag(struct libmnt_cache *cache, const char *devname,
+				const char *token, const char *value)
+{
+	const char *path = cache_find_tag(cache, token, value);
+
+	if (path && devname && strcmp(path, devname) == 0)
+		return 1;
+	return 0;
+}
+
+static int __mnt_cache_find_tag_value(struct libmnt_cache *cache,
+		const char *devname, const char *token, char **data)
+{
+	int rc = 0;
+
+	if (!cache || !devname || !token || !data)
+		return -EINVAL;
+
+	rc = mnt_cache_read_tags(cache, devname);
+	if (rc)
+		return rc;
+
+	*data = cache_find_tag_value(cache, devname, token);
+	return *data ? 0 : -1;
+}
+
+/**
+ * mnt_cache_find_tag_value:
+ * @cache: cache for results
+ * @devname: device name
+ * @token: tag name ("LABEL" or "UUID")
+ *
+ * Returns: LABEL or UUID for the @devname or NULL in case of error.
+ */
+char *mnt_cache_find_tag_value(struct libmnt_cache *cache,
+		const char *devname, const char *token)
+{
+	char *data = NULL;
+
+	if (__mnt_cache_find_tag_value(cache, devname, token, &data) == 0)
+		return data;
+	return NULL;
+}
+
+/**
+ * mnt_get_fstype:
+ * @devname: device name
+ * @ambi: returns TRUE if probing result is ambivalent (optional argument)
+ * @cache: cache for results or NULL
+ *
+ * Returns: filesystem type or NULL in case of error. The result has to be
+ * deallocated by free() if @cache is NULL.
+ */
+char *mnt_get_fstype(const char *devname, int *ambi, struct libmnt_cache *cache)
+{
+	blkid_probe pr;
+	const char *data;
+	char *type = NULL;
+	int rc;
+
+	DBG(CACHE, ul_debugobj(cache, "get %s FS type", devname));
+
+	if (cache) {
+		char *val = NULL;
+		rc = __mnt_cache_find_tag_value(cache, devname, "TYPE", &val);
+		if (ambi)
+			*ambi = rc == -2 ? TRUE : FALSE;
+		return rc ? NULL : val;
+	}
+
+	/*
+	 * no cache, probe directly
+	 */
+	pr =  blkid_new_probe_from_filename(devname);
+	if (!pr)
+		return NULL;
+
+	blkid_probe_enable_superblocks(pr, 1);
+	blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_TYPE);
+
+	rc = blkid_do_safeprobe(pr);
+
+	DBG(CACHE, ul_debugobj(cache, "libblkid rc=%d", rc));
+
+	if (!rc && !blkid_probe_lookup_value(pr, "TYPE", &data, NULL))
+		type = strdup(data);
+
+	if (ambi)
+		*ambi = rc == -2 ? TRUE : FALSE;
+
+	blkid_free_probe(pr);
+	return type;
+}
+
+static char *canonicalize_path_and_cache(const char *path,
+						struct libmnt_cache *cache)
+{
+	char *p;
+	char *key;
+	char *value;
+
+	DBG(CACHE, ul_debugobj(cache, "canonicalize path %s", path));
+	p = canonicalize_path(path);
+
+	if (p && cache) {
+		value = p;
+		key = strcmp(path, p) == 0 ? value : strdup(path);
+
+		if (!key || !value)
+			goto error;
+
+		if (cache_add_entry(cache, key, value,
+				MNT_CACHE_ISPATH))
+			goto error;
+	}
+
+	return p;
+error:
+	if (value != key)
+		free(value);
+	free(key);
+	return NULL;
+}
+
+/**
+ * mnt_resolve_path:
+ * @path: "native" path
+ * @cache: cache for results or NULL
+ *
+ * Converts path:
+ *	- to the absolute path
+ *	- /dev/dm-N to /dev/mapper/name
+ *
+ * Returns: absolute path or NULL in case of error. The result has to be
+ * deallocated by free() if @cache is NULL.
+ */
+char *mnt_resolve_path(const char *path, struct libmnt_cache *cache)
+{
+	char *p = NULL;
+
+	/*DBG(CACHE, ul_debugobj(cache, "resolving path %s", path));*/
+
+	if (!path)
+		return NULL;
+	if (cache)
+		p = (char *) cache_find_path(cache, path);
+	if (!p)
+		p = canonicalize_path_and_cache(path, cache);
+
+	return p;
+}
+
+/**
+ * mnt_resolve_target:
+ * @path: "native" path, a potential mount point
+ * @cache: cache for results or NULL.
+ *
+ * Like mnt_resolve_path(), unless @cache is not NULL and
+ * mnt_cache_set_targets(cache, mtab) was called: if @path is found in the
+ * cached @mtab and the matching entry was provided by the kernel, assume that
+ * @path is already canonicalized. By avoiding a call to realpath(2) on
+ * known mount points, there is a lower risk of stepping on a stale mount
+ * point, which can result in an application freeze. This is also faster in
+ * general, as stat(2) on a mount point is slower than on a regular file.
+ *
+ * Returns: absolute path or NULL in case of error. The result has to be
+ * deallocated by free() if @cache is NULL.
+ */
+char *mnt_resolve_target(const char *path, struct libmnt_cache *cache)
+{
+	char *p = NULL;
+
+	/*DBG(CACHE, ul_debugobj(cache, "resolving target %s", path));*/
+
+	if (!cache || !cache->mtab)
+		return mnt_resolve_path(path, cache);
+
+	p = (char *) cache_find_path(cache, path);
+	if (p)
+		return p;
+
+	{
+		struct libmnt_iter itr;
+		struct libmnt_fs *fs = NULL;
+
+		mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
+		while (mnt_table_next_fs(cache->mtab, &itr, &fs) == 0) {
+
+			if (!mnt_fs_is_kernel(fs)
+			     || mnt_fs_is_swaparea(fs)
+			     || !mnt_fs_streq_target(fs, path))
+				continue;
+
+			p = strdup(path);
+			if (!p)
+				return NULL;	/* ENOMEM */
+
+			if (cache_add_entry(cache, p, p, MNT_CACHE_ISPATH)) {
+				free(p);
+				return NULL;	/* ENOMEM */
+			}
+			break;
+		}
+	}
+
+	if (!p)
+		p = canonicalize_path_and_cache(path, cache);
+	return p;
+}
+
+/**
+ * mnt_pretty_path:
+ * @path: any path
+ * @cache: NULL or pointer to the cache
+ *
+ * Converts path:
+ *	- to the absolute path
+ *	- /dev/dm-N to /dev/mapper/name
+ *	- /dev/loopN to the loop backing filename
+ *	- empty path (NULL) to 'none'
+ *
+ * Returns: newly allocated string with path, result always has to be deallocated
+ *          by free().
+ */
+char *mnt_pretty_path(const char *path, struct libmnt_cache *cache)
+{
+	char *pretty = mnt_resolve_path(path, cache);
+
+	if (!pretty)
+		return strdup("none");
+
+#ifdef __linux__
+	/* users assume backing file name rather than /dev/loopN in
+	 * output if the device has been initialized by mount(8).
+	 */
+	if (strncmp(pretty, "/dev/loop", 9) == 0) {
+		struct loopdev_cxt lc;
+
+		if (loopcxt_init(&lc, 0) || loopcxt_set_device(&lc, pretty))
+			goto done;
+
+		if (loopcxt_is_autoclear(&lc)) {
+			char *tmp = loopcxt_get_backing_file(&lc);
+			if (tmp) {
+				loopcxt_deinit(&lc);
+				if (!cache)
+					free(pretty);	/* not cached, deallocate */
+				return tmp;		/* return backing file */
+			}
+		}
+		loopcxt_deinit(&lc);
+
+	}
+#endif
+
+done:
+	/* don't return pointer to the cache, allocate a new string */
+	return cache ? strdup(pretty) : pretty;
+}
+
+/**
+ * mnt_resolve_tag:
+ * @token: tag name
+ * @value: tag value
+ * @cache: for results or NULL
+ *
+ * Returns: device name or NULL in case of error. The result has to be
+ * deallocated by free() if @cache is NULL.
+ */
+char *mnt_resolve_tag(const char *token, const char *value,
+		      struct libmnt_cache *cache)
+{
+	char *p = NULL;
+
+	/*DBG(CACHE, ul_debugobj(cache, "resolving tag token=%s value=%s",
+				token, value));*/
+
+	if (!token || !value)
+		return NULL;
+
+	if (cache)
+		p = (char *) cache_find_tag(cache, token, value);
+
+	if (!p) {
+		/* returns newly allocated string */
+		p = blkid_evaluate_tag(token, value, cache ? &cache->bc : NULL);
+
+		if (p && cache &&
+		    cache_add_tag(cache, token, value, p, 0))
+				goto error;
+	}
+
+	return p;
+error:
+	free(p);
+	return NULL;
+}
+
+
+
+/**
+ * mnt_resolve_spec:
+ * @spec: path or tag
+ * @cache: paths cache
+ *
+ * Returns: canonicalized path or NULL. The result has to be
+ * deallocated by free() if @cache is NULL.
+ */
+char *mnt_resolve_spec(const char *spec, struct libmnt_cache *cache)
+{
+	char *cn = NULL;
+	char *t = NULL, *v = NULL;
+
+	if (!spec)
+		return NULL;
+
+	if (blkid_parse_tag_string(spec, &t, &v) == 0 && mnt_valid_tagname(t))
+		cn = mnt_resolve_tag(t, v, cache);
+	else
+		cn = mnt_resolve_path(spec, cache);
+
+	free(t);
+	free(v);
+	return cn;
+}
+
+
+#ifdef TEST_PROGRAM
+
+static int test_resolve_path(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char line[BUFSIZ];
+	struct libmnt_cache *cache;
+
+	cache = mnt_new_cache();
+	if (!cache)
+		return -ENOMEM;
+
+	while(fgets(line, sizeof(line), stdin)) {
+		size_t sz = strlen(line);
+		char *p;
+
+		if (sz > 0 && line[sz - 1] == '\n')
+			line[sz - 1] = '\0';
+
+		p = mnt_resolve_path(line, cache);
+		printf("%s : %s\n", line, p);
+	}
+	mnt_unref_cache(cache);
+	return 0;
+}
+
+static int test_resolve_spec(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char line[BUFSIZ];
+	struct libmnt_cache *cache;
+
+	cache = mnt_new_cache();
+	if (!cache)
+		return -ENOMEM;
+
+	while(fgets(line, sizeof(line), stdin)) {
+		size_t sz = strlen(line);
+		char *p;
+
+		if (sz > 0 && line[sz - 1] == '\n')
+			line[sz - 1] = '\0';
+
+		p = mnt_resolve_spec(line, cache);
+		printf("%s : %s\n", line, p);
+	}
+	mnt_unref_cache(cache);
+	return 0;
+}
+
+static int test_read_tags(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char line[BUFSIZ];
+	struct libmnt_cache *cache;
+	size_t i;
+
+	cache = mnt_new_cache();
+	if (!cache)
+		return -ENOMEM;
+
+	while(fgets(line, sizeof(line), stdin)) {
+		size_t sz = strlen(line);
+		char *t = NULL, *v = NULL;
+
+		if (sz > 0 && line[sz - 1] == '\n')
+			line[sz - 1] = '\0';
+
+		if (!strcmp(line, "quit"))
+			break;
+
+		if (*line == '/') {
+			if (mnt_cache_read_tags(cache, line) < 0)
+				fprintf(stderr, "%s: read tags failed\n", line);
+
+		} else if (blkid_parse_tag_string(line, &t, &v) == 0) {
+			const char *cn = NULL;
+
+			if (mnt_valid_tagname(t))
+				cn = cache_find_tag(cache, t, v);
+			free(t);
+			free(v);
+
+			if (cn)
+				printf("%s: %s\n", line, cn);
+			else
+				printf("%s: not cached\n", line);
+		}
+	}
+
+	for (i = 0; i < cache->nents; i++) {
+		struct mnt_cache_entry *e = &cache->ents[i];
+		if (!(e->flag & MNT_CACHE_ISTAG))
+			continue;
+
+		printf("%15s : %5s : %s\n", e->value, e->key,
+				e->key + strlen(e->key) + 1);
+	}
+
+	mnt_unref_cache(cache);
+	return 0;
+
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test ts[] = {
+		{ "--resolve-path", test_resolve_path, "  resolve paths from stdin" },
+		{ "--resolve-spec", test_resolve_spec, "  evaluate specs from stdin" },
+		{ "--read-tags", test_read_tags,       "  read devname or TAG from stdin (\"quit\" to exit)" },
+		{ NULL }
+	};
+
+	return mnt_run_test(ts, argc, argv);
+}
+#endif
diff --git a/libmount/src/context.c b/libmount/src/context.c
new file mode 100644
index 0000000..6196c71
--- /dev/null
+++ b/libmount/src/context.c
@@ -0,0 +1,3442 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: context
+ * @title: Library high-level context
+ * @short_description: high-level API to mount/umount devices.
+ *
+ * <informalexample>
+ *   <programlisting>
+ *	struct libmnt_context *cxt = mnt_new_context();
+ *
+ *	mnt_context_set_options(cxt, "aaa,bbb,ccc=CCC");
+ *	mnt_context_set_mflags(cxt, MS_NOATIME|MS_NOEXEC);
+ *	mnt_context_set_target(cxt, "/mnt/foo");
+ *
+ *	if (!mnt_context_mount(cxt))
+ *		printf("successfully mounted\n");
+ *	mnt_free_context(cxt);
+ *
+ *   </programlisting>
+ * </informalexample>
+ *
+ * This code is similar to:
+ *
+ *   mount -o aaa,bbb,ccc=CCC,noatime,noexec /mnt/foo
+ *
+ */
+
+#include "mountP.h"
+#include "fileutils.h"
+#include "strutils.h"
+#include "namespace.h"
+
+#include <sys/wait.h>
+
+/**
+ * mnt_new_context:
+ *
+ * Returns: newly allocated mount context
+ */
+struct libmnt_context *mnt_new_context(void)
+{
+	struct libmnt_context *cxt;
+	uid_t ruid, euid;
+
+	cxt = calloc(1, sizeof(*cxt));
+	if (!cxt)
+		return NULL;
+
+	INIT_LIST_HEAD(&cxt->addmounts);
+
+	ruid = getuid();
+	euid = geteuid();
+
+	mnt_context_reset_status(cxt);
+
+	cxt->loopdev_fd = -1;
+
+	cxt->ns_orig.fd = -1;
+	cxt->ns_tgt.fd = -1;
+	cxt->ns_cur = &cxt->ns_orig;
+
+	/* if we're really root and aren't running setuid */
+	cxt->restricted = (uid_t) 0 == ruid && ruid == euid ? 0 : 1;
+
+	DBG(CXT, ul_debugobj(cxt, "----> allocate %s",
+				cxt->restricted ? "[RESTRICTED]" : ""));
+
+
+	return cxt;
+}
+
+/**
+ * mnt_free_context:
+ * @cxt: mount context
+ *
+ * Deallocates context struct.
+ */
+void mnt_free_context(struct libmnt_context *cxt)
+{
+	if (!cxt)
+		return;
+
+	mnt_reset_context(cxt);
+
+	free(cxt->fstype_pattern);
+	free(cxt->optstr_pattern);
+	free(cxt->tgt_prefix);
+
+	mnt_unref_table(cxt->fstab);
+	mnt_unref_cache(cxt->cache);
+	mnt_unref_fs(cxt->fs);
+	mnt_unref_fs(cxt->fs_template);
+
+	mnt_context_clear_loopdev(cxt);
+	mnt_free_lock(cxt->lock);
+	mnt_free_update(cxt->update);
+
+	mnt_context_set_target_ns(cxt, NULL);
+
+	free(cxt->children);
+
+	DBG(CXT, ul_debugobj(cxt, "<---- free"));
+	free(cxt);
+}
+
+/**
+ * mnt_reset_context:
+ * @cxt: mount context
+ *
+ * Resets all information in the context that is directly related to
+ * the latest mount (spec, source, target, mount options, ...).
+ *
+ * The match patterns, target namespace, prefix, cached fstab, cached canonicalized
+ * paths and tags and [e]uid are not reset. You have to use
+ *
+ *	mnt_context_set_fstab(cxt, NULL);
+ *	mnt_context_set_cache(cxt, NULL);
+ *	mnt_context_set_fstype_pattern(cxt, NULL);
+ *	mnt_context_set_options_pattern(cxt, NULL);
+ *	mnt_context_set_target_ns(cxt, NULL);
+ *
+ *
+ * to reset this stuff.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_reset_context(struct libmnt_context *cxt)
+{
+	int fl;
+
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "<---- reset [status=%d] ---->",
+				mnt_context_get_status(cxt)));
+
+	fl = cxt->flags;
+
+	mnt_unref_fs(cxt->fs);
+	mnt_unref_table(cxt->mtab);
+	mnt_unref_table(cxt->utab);
+
+	free(cxt->helper);
+	free(cxt->orig_user);
+
+	cxt->fs = NULL;
+	cxt->mtab = NULL;
+	cxt->utab = NULL;
+	cxt->helper = NULL;
+	cxt->orig_user = NULL;
+	cxt->mountflags = 0;
+	cxt->user_mountflags = 0;
+	cxt->mountdata = NULL;
+	cxt->flags = MNT_FL_DEFAULT;
+
+	/* free additional mounts list */
+	while (!list_empty(&cxt->addmounts)) {
+		struct libmnt_addmount *ad = list_entry(cxt->addmounts.next,
+				                  struct libmnt_addmount,
+						  mounts);
+		mnt_free_addmount(ad);
+	}
+
+	mnt_context_reset_status(cxt);
+
+	if (cxt->table_fltrcb)
+		mnt_context_set_tabfilter(cxt, NULL, NULL);
+
+	/* restore non-resettable flags */
+	cxt->flags |= (fl & MNT_FL_NOMTAB);
+	cxt->flags |= (fl & MNT_FL_FAKE);
+	cxt->flags |= (fl & MNT_FL_SLOPPY);
+	cxt->flags |= (fl & MNT_FL_VERBOSE);
+	cxt->flags |= (fl & MNT_FL_NOHELPERS);
+	cxt->flags |= (fl & MNT_FL_LOOPDEL);
+	cxt->flags |= (fl & MNT_FL_LAZY);
+	cxt->flags |= (fl & MNT_FL_FORK);
+	cxt->flags |= (fl & MNT_FL_FORCE);
+	cxt->flags |= (fl & MNT_FL_NOCANONICALIZE);
+	cxt->flags |= (fl & MNT_FL_RDONLY_UMOUNT);
+	cxt->flags |= (fl & MNT_FL_RWONLY_MOUNT);
+	cxt->flags |= (fl & MNT_FL_NOSWAPMATCH);
+	cxt->flags |= (fl & MNT_FL_TABPATHS_CHECKED);
+
+	mnt_context_apply_template(cxt);
+
+	return 0;
+}
+
+/*
+ * Saves the current context FS setting (mount options, etc) to make it usable after
+ * mnt_reset_context() or by mnt_context_apply_template(). This is usable for
+ * example for mnt_context_next_mount() where for the next mount operation we
+ * need to restore to the original context setting.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_save_template(struct libmnt_context *cxt)
+{
+	struct libmnt_fs *fs = NULL;
+
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "save FS as template"));
+
+	if (cxt->fs) {
+		fs = mnt_copy_fs(NULL, cxt->fs);
+		if (!fs)
+			return -ENOMEM;
+	}
+
+	mnt_unref_fs(cxt->fs_template);
+	cxt->fs_template = fs;
+
+	return 0;
+}
+
+/*
+ * Restores context FS setting from previously saved template (see
+ * mnt_context_save_template()).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_apply_template(struct libmnt_context *cxt)
+{
+	struct libmnt_fs *fs = NULL;
+	int rc = 0;
+
+	if (!cxt)
+		return -EINVAL;
+
+	if (cxt->fs_template) {
+		DBG(CXT, ul_debugobj(cxt, "copy FS from template"));
+		fs = mnt_copy_fs(NULL, cxt->fs_template);
+		if (!fs)
+			return -ENOMEM;
+		rc = mnt_context_set_fs(cxt, fs);
+		mnt_unref_fs(fs);
+	} else {
+		DBG(CXT, ul_debugobj(cxt, "no FS template, reset only"));
+		mnt_unref_fs(cxt->fs);
+		cxt->fs = NULL;
+	}
+
+	return rc;
+}
+
+int mnt_context_has_template(struct libmnt_context *cxt)
+{
+	return cxt && cxt->fs_template ? 1 : 0;
+}
+
+struct libmnt_context *mnt_copy_context(struct libmnt_context *o)
+{
+	struct libmnt_context *n;
+
+	n = mnt_new_context();
+	if (!n)
+		return NULL;
+
+	DBG(CXT, ul_debugobj(n, "<---- clone ---->"));
+
+	n->flags = o->flags;
+
+	if (o->fs) {
+		n->fs = mnt_copy_fs(NULL, o->fs);
+		if (!n->fs)
+			goto failed;
+	}
+
+	n->mtab = o->mtab;
+	mnt_ref_table(n->mtab);
+
+	n->mtab = o->utab;
+	mnt_ref_table(n->utab);
+
+	if (strdup_between_structs(n, o, tgt_prefix))
+		goto failed;
+	if (strdup_between_structs(n, o, helper))
+		goto failed;
+	if (strdup_between_structs(n, o, orig_user))
+		goto failed;
+
+	n->mountflags = o->mountflags;
+	n->mountdata = o->mountdata;
+
+	mnt_context_reset_status(n);
+
+	n->table_fltrcb = o->table_fltrcb;
+	n->table_fltrcb_data = o->table_fltrcb_data;
+
+	return n;
+failed:
+	mnt_free_context(n);
+	return NULL;
+}
+
+/**
+ * mnt_context_reset_status:
+ * @cxt: context
+ *
+ * Resets mount(2) and mount.type statuses, so mnt_context_do_mount() or
+ * mnt_context_do_umount() could be again called with the same settings.
+ *
+ * BE CAREFUL -- after this soft reset the libmount will NOT parse mount
+ * options, evaluate permissions or apply stuff from fstab.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_reset_status(struct libmnt_context *cxt)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	cxt->syscall_status = 1;		/* means not called yet */
+	cxt->helper_exec_status = 1;
+	cxt->helper_status = 0;
+	return 0;
+}
+
+static int context_init_paths(struct libmnt_context *cxt, int writable)
+{
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	if (!cxt->mtab_path) {
+		cxt->mtab_path = mnt_get_mtab_path();
+		DBG(CXT, ul_debugobj(cxt, "mtab path initialized to: %s", cxt->mtab_path));
+	}
+#endif
+	if (!cxt->utab_path) {
+		cxt->utab_path = mnt_get_utab_path();
+		DBG(CXT, ul_debugobj(cxt, "utab path initialized to: %s", cxt->utab_path));
+	}
+
+	if (!writable)
+		return 0;		/* only paths wanted */
+	if (mnt_context_is_nomtab(cxt))
+		return 0;		/* write mode overridden by mount -n */
+	if (cxt->flags & MNT_FL_TABPATHS_CHECKED)
+		return 0;
+
+	DBG(CXT, ul_debugobj(cxt, "checking for writable tab files"));
+
+	cxt->mtab_writable = 0;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	mnt_has_regular_mtab(&cxt->mtab_path, &cxt->mtab_writable);
+	if (!cxt->mtab_writable)
+#endif
+		/* use /run/mount/utab if /etc/mtab is useless */
+		mnt_has_regular_utab(&cxt->utab_path, &cxt->utab_writable);
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	cxt->flags |= MNT_FL_TABPATHS_CHECKED;
+	return 0;
+}
+
+int mnt_context_mtab_writable(struct libmnt_context *cxt)
+{
+	assert(cxt);
+
+	context_init_paths(cxt, 1);
+	return cxt->mtab_writable == 1;
+}
+
+int mnt_context_utab_writable(struct libmnt_context *cxt)
+{
+	assert(cxt);
+
+	context_init_paths(cxt, 1);
+	return cxt->utab_writable == 1;
+}
+
+const char *mnt_context_get_writable_tabpath(struct libmnt_context *cxt)
+{
+	assert(cxt);
+
+	context_init_paths(cxt, 1);
+	return cxt->mtab_writable ? cxt->mtab_path : cxt->utab_path;
+}
+
+
+static int set_flag(struct libmnt_context *cxt, int flag, int enable)
+{
+	if (!cxt)
+		return -EINVAL;
+	if (enable) {
+		DBG(CXT, ul_debugobj(cxt, "enabling flag %04x", flag));
+		cxt->flags |= flag;
+	} else {
+		DBG(CXT, ul_debugobj(cxt, "disabling flag %04x", flag));
+		cxt->flags &= ~flag;
+	}
+	return 0;
+}
+
+/**
+ * mnt_context_is_restricted:
+ * @cxt: mount context
+ *
+ * Returns: 0 for an unrestricted mount (user is root), or 1 for non-root mounts
+ */
+int mnt_context_is_restricted(struct libmnt_context *cxt)
+{
+	return cxt->restricted;
+}
+
+/**
+ * mnt_context_force_unrestricted:
+ * @cxt: mount context
+ *
+ * This function is DANGEROURS as it disables all security policies in libmount.
+ * Don't use if not sure. It removes "restricted" flag from the context, so
+ * libmount will use the current context as for root user.
+ *
+ * This function is designed for case you have no any suid permissions, so you
+ * can depend on kernel.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ *
+ * Since: 2.35
+ */
+int mnt_context_force_unrestricted(struct libmnt_context *cxt)
+{
+	if (mnt_context_is_restricted(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "force UNRESTRICTED"));
+		cxt->restricted = 0;
+	}
+
+	return 0;
+}
+
+/**
+ * mnt_context_set_optsmode
+ * @cxt: mount context
+ * @mode: MNT_OMODE_* flags
+ *
+ * Controls how to use mount optionssource and target paths from fstab/mtab.
+ *
+ * @MNT_OMODE_IGNORE: ignore mtab/fstab options
+ *
+ * @MNT_OMODE_APPEND: append mtab/fstab options to existing options
+ *
+ * @MNT_OMODE_PREPEND: prepend mtab/fstab options to existing options
+ *
+ * @MNT_OMODE_REPLACE: replace existing options with options from mtab/fstab
+ *
+ * @MNT_OMODE_FORCE: always read mtab/fstab (although source and target are defined)
+ *
+ * @MNT_OMODE_FSTAB: read from fstab
+ *
+ * @MNT_OMODE_MTAB: read from mtab if fstab not enabled or failed
+ *
+ * @MNT_OMODE_NOTAB: do not read fstab/mtab at all
+ *
+ * @MNT_OMODE_AUTO: default mode (MNT_OMODE_PREPEND | MNT_OMODE_FSTAB | MNT_OMODE_MTAB)
+ *
+ * @MNT_OMODE_USER: default for non-root users (MNT_OMODE_REPLACE | MNT_OMODE_FORCE | MNT_OMODE_FSTAB)
+ *
+ * Notes:
+ *
+ * - MNT_OMODE_USER is always used if mount context is in restricted mode
+ * - MNT_OMODE_AUTO is used if nothing else is defined
+ * - the flags are evaluated in this order: MNT_OMODE_NOTAB, MNT_OMODE_FORCE,
+ *   MNT_OMODE_FSTAB, MNT_OMODE_MTAB and then the mount options from fstab/mtab
+ *   are set according to MNT_OMODE_{IGNORE,APPEND,PREPEND,REPLACE}
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_optsmode(struct libmnt_context *cxt, int mode)
+{
+	if (!cxt)
+		return -EINVAL;
+	cxt->optsmode = mode;
+	return 0;
+}
+
+/**
+ * mnt_context_get_optsmode
+ * @cxt: mount context
+ *
+ * Returns: MNT_OMODE_* mask or zero.
+ */
+
+int mnt_context_get_optsmode(struct libmnt_context *cxt)
+{
+	return cxt->optsmode;
+}
+
+/**
+ * mnt_context_disable_canonicalize:
+ * @cxt: mount context
+ * @disable: TRUE or FALSE
+ *
+ * Enable/disable paths canonicalization and tags evaluation. The libmount context
+ * canonicalizes paths when searching in fstab and when preparing source and target paths
+ * for mount(2) syscall.
+ *
+ * This function has an effect on the private (within context) fstab instance only
+ * (see mnt_context_set_fstab()). If you want to use an external fstab then you
+ * need to manage your private struct libmnt_cache (see mnt_table_set_cache(fstab,
+ * NULL).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_disable_canonicalize(struct libmnt_context *cxt, int disable)
+{
+	return set_flag(cxt, MNT_FL_NOCANONICALIZE, disable);
+}
+
+/**
+ * mnt_context_is_nocanonicalize:
+ * @cxt: mount context
+ *
+ * Returns: 1 if no-canonicalize mode is enabled or 0.
+ */
+int mnt_context_is_nocanonicalize(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_NOCANONICALIZE ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_lazy:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable lazy umount (see umount(8) man page, option -l).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_lazy(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_LAZY, enable);
+}
+
+/**
+ * mnt_context_is_lazy:
+ * @cxt: mount context
+ *
+ * Returns: 1 if lazy umount is enabled or 0
+ */
+int mnt_context_is_lazy(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_LAZY ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_fork:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable fork(2) call in mnt_context_next_mount() (see mount(8) man
+ * page, option -F).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_fork(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_FORK, enable);
+}
+
+/**
+ * mnt_context_is_fork:
+ * @cxt: mount context
+ *
+ * Returns: 1 if fork (mount -F) is enabled or 0
+ */
+int mnt_context_is_fork(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_FORK ? 1 : 0;
+}
+
+/**
+ * mnt_context_is_parent:
+ * @cxt: mount context
+ *
+ * Return: 1 if mount -F enabled and the current context is parent, or 0
+ */
+int mnt_context_is_parent(struct libmnt_context *cxt)
+{
+	return mnt_context_is_fork(cxt) && cxt->pid == 0;
+}
+
+/**
+ * mnt_context_is_child:
+ * @cxt: mount context
+ *
+ * Return: 1 f the current context is child, or 0
+ */
+int mnt_context_is_child(struct libmnt_context *cxt)
+{
+	/* See mnt_fork_context(), the for fork flag is always disabled
+	 * for children to avoid recursive forking.
+	 */
+	return !mnt_context_is_fork(cxt) && cxt->pid;
+}
+
+/**
+ * mnt_context_enable_rdonly_umount:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable read-only remount on failed umount(2)
+ * (see umount(8) man page, option -r).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_rdonly_umount(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_RDONLY_UMOUNT, enable);
+}
+
+/**
+ * mnt_context_is_rdonly_umount
+ * @cxt: mount context
+ *
+ * See also mnt_context_enable_rdonly_umount() and umount(8) man page,
+ * option -r.
+ *
+ * Returns: 1 if read-only remount failed umount(2) is enables or 0
+ */
+int mnt_context_is_rdonly_umount(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_RDONLY_UMOUNT ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_rwonly_mount:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Force read-write mount; if enabled libmount will never try MS_RDONLY
+ * after failed mount(2) EROFS. (See mount(8) man page, option -w).
+ *
+ * Since: 2.30
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_rwonly_mount(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_RWONLY_MOUNT, enable);
+}
+
+/**
+ * mnt_context_is_rwonly_mount
+ * @cxt: mount context
+ *
+ * See also mnt_context_enable_rwonly_mount() and mount(8) man page,
+ * option -w.
+ *
+ * Since: 2.30
+ *
+ * Returns: 1 if only read-write mount is allowed.
+ */
+int mnt_context_is_rwonly_mount(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_RWONLY_MOUNT ? 1 : 0;
+}
+
+/**
+ * mnt_context_forced_rdonly:
+ * @cxt: mount context
+ *
+ * See also mnt_context_enable_rwonly_mount().
+ *
+ * Since: 2.30
+ *
+ * Returns: 1 if mounted read-only on write-protected device.
+ */
+int mnt_context_forced_rdonly(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_FORCED_RDONLY ? 1 : 0;
+}
+
+/**
+ * mnt_context_disable_helpers:
+ * @cxt: mount context
+ * @disable: TRUE or FALSE
+ *
+ * Enable/disable /sbin/[u]mount.* helpers (see mount(8) man page, option -i).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_disable_helpers(struct libmnt_context *cxt, int disable)
+{
+	return set_flag(cxt, MNT_FL_NOHELPERS, disable);
+}
+
+/**
+ * mnt_context_is_nohelpers
+ * @cxt: mount context
+ *
+ * Returns: 1 if helpers are disabled (mount -i) or 0
+ */
+int mnt_context_is_nohelpers(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_NOHELPERS ? 1 : 0;
+}
+
+
+/**
+ * mnt_context_enable_sloppy:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Set/unset sloppy mounting (see mount(8) man page, option -s).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_sloppy(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_SLOPPY, enable);
+}
+
+/**
+ * mnt_context_is_sloppy:
+ * @cxt: mount context
+ *
+ * Returns: 1 if sloppy flag is enabled or 0
+ */
+int mnt_context_is_sloppy(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_SLOPPY ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_fake:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable fake mounting (see mount(8) man page, option -f).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_fake(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_FAKE, enable);
+}
+
+/**
+ * mnt_context_is_fake:
+ * @cxt: mount context
+ *
+ * Returns: 1 if fake flag is enabled or 0
+ */
+int mnt_context_is_fake(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_FAKE ? 1 : 0;
+}
+
+/**
+ * mnt_context_disable_mtab:
+ * @cxt: mount context
+ * @disable: TRUE or FALSE
+ *
+ * Disable/enable mtab update (see mount(8) man page, option -n).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_disable_mtab(struct libmnt_context *cxt, int disable)
+{
+	return set_flag(cxt, MNT_FL_NOMTAB, disable);
+}
+
+/**
+ * mnt_context_is_nomtab:
+ * @cxt: mount context
+ *
+ * Returns: 1 if no-mtab is enabled or 0
+ */
+int mnt_context_is_nomtab(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_NOMTAB ? 1 : 0;
+}
+
+/**
+ * mnt_context_disable_swapmatch:
+ * @cxt: mount context
+ * @disable: TRUE or FALSE
+ *
+ * Disable/enable swap between source and target for mount(8) if only one path
+ * is specified.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_disable_swapmatch(struct libmnt_context *cxt, int disable)
+{
+	return set_flag(cxt, MNT_FL_NOSWAPMATCH, disable);
+}
+
+/**
+ * mnt_context_is_swapmatch:
+ * @cxt: mount context
+ *
+ * Returns: 1 if swap between source and target is allowed (default is 1) or 0.
+ */
+int mnt_context_is_swapmatch(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_NOSWAPMATCH ? 0 : 1;
+}
+
+/**
+ * mnt_context_enable_force:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable force umounting (see umount(8) man page, option -f).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_force(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_FORCE, enable);
+}
+
+/**
+ * mnt_context_is_force
+ * @cxt: mount context
+ *
+ * Returns: 1 if force umounting flag is enabled or 0
+ */
+int mnt_context_is_force(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_FORCE ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_verbose:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable verbose output (TODO: not implemented yet)
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_verbose(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_VERBOSE, enable);
+}
+
+/**
+ * mnt_context_is_verbose
+ * @cxt: mount context
+ *
+ * Returns: 1 if verbose flag is enabled or 0
+ */
+int mnt_context_is_verbose(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_VERBOSE ? 1 : 0;
+}
+
+/**
+ * mnt_context_enable_loopdel:
+ * @cxt: mount context
+ * @enable: TRUE or FALSE
+ *
+ * Enable/disable the loop delete (destroy) after umount (see umount(8), option -d)
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_enable_loopdel(struct libmnt_context *cxt, int enable)
+{
+	return set_flag(cxt, MNT_FL_LOOPDEL, enable);
+}
+
+/**
+ * mnt_context_is_loopdel:
+ * @cxt: mount context
+ *
+ * Returns: 1 if loop device should be deleted after umount (umount -d) or 0.
+ */
+int mnt_context_is_loopdel(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_LOOPDEL ? 1 : 0;
+}
+
+/**
+ * mnt_context_set_fs:
+ * @cxt: mount context
+ * @fs: filesystem description
+ *
+ * The mount context uses private @fs by default. This function can be used to
+ * overwrite the private @fs with an external instance. This function
+ * increments @fs reference counter (and decrement reference counter of the
+ * old fs).
+ *
+ * The @fs will be modified by mnt_context_set_{source,target,options,fstype}
+ * functions, If the @fs is NULL, then all current FS specific settings (source,
+ * target, etc., exclude spec) are reset.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_fs(struct libmnt_context *cxt, struct libmnt_fs *fs)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "setting new FS"));
+	mnt_ref_fs(fs);			/* new */
+	mnt_unref_fs(cxt->fs);		/* old */
+	cxt->fs = fs;
+	return 0;
+}
+
+/**
+ * mnt_context_get_fs:
+ * @cxt: mount context
+ *
+ * The FS contains the basic description of mountpoint, fs type and so on.
+ * Note that the FS is modified by mnt_context_set_{source,target,options,fstype}
+ * functions.
+ *
+ * Returns: pointer to FS description or NULL in case of a calloc() error.
+ */
+struct libmnt_fs *mnt_context_get_fs(struct libmnt_context *cxt)
+{
+	if (!cxt)
+		return NULL;
+	if (!cxt->fs)
+		cxt->fs = mnt_new_fs();
+	return cxt->fs;
+}
+
+/**
+ * mnt_context_get_fs_userdata:
+ * @cxt: mount context
+ *
+ * Returns: pointer to userdata or NULL.
+ */
+void *mnt_context_get_fs_userdata(struct libmnt_context *cxt)
+{
+	return cxt->fs ? mnt_fs_get_userdata(cxt->fs) : NULL;
+}
+
+/**
+ * mnt_context_get_fstab_userdata:
+ * @cxt: mount context
+ *
+ * Returns: pointer to userdata or NULL.
+ */
+void *mnt_context_get_fstab_userdata(struct libmnt_context *cxt)
+{
+	return cxt->fstab ? mnt_table_get_userdata(cxt->fstab) : NULL;
+}
+
+/**
+ * mnt_context_get_mtab_userdata:
+ * @cxt: mount context
+ *
+ * Returns: pointer to userdata or NULL.
+ */
+void *mnt_context_get_mtab_userdata(struct libmnt_context *cxt)
+{
+	return cxt->mtab ? mnt_table_get_userdata(cxt->mtab) : NULL;
+}
+
+/**
+ * mnt_context_set_source:
+ * @cxt: mount context
+ * @source: mount source (device, directory, UUID, LABEL, ...)
+ *
+ * Note that libmount does not interpret "nofail" (MNT_MS_NOFAIL)
+ * mount option. The real return code is always returned, when
+ * the device does not exist then it's usually MNT_ERR_NOSOURCE
+ * from libmount or ENOENT, ENOTDIR, ENOTBLK, ENXIO from mount(2).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_source(struct libmnt_context *cxt, const char *source)
+{
+	return mnt_fs_set_source(mnt_context_get_fs(cxt), source);
+}
+
+/**
+ * mnt_context_get_source:
+ * @cxt: mount context
+ *
+ * Returns: returns pointer or NULL in case of error or if not set.
+ */
+const char *mnt_context_get_source(struct libmnt_context *cxt)
+{
+	return mnt_fs_get_source(mnt_context_get_fs(cxt));
+}
+
+/**
+ * mnt_context_set_target:
+ * @cxt: mount context
+ * @target: mountpoint
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_target(struct libmnt_context *cxt, const char *target)
+{
+	return mnt_fs_set_target(mnt_context_get_fs(cxt), target);
+}
+
+/**
+ * mnt_context_get_target:
+ * @cxt: mount context
+ *
+ * Returns: returns pointer or NULL in case of error or if not set.
+ */
+const char *mnt_context_get_target(struct libmnt_context *cxt)
+{
+	return mnt_fs_get_target(mnt_context_get_fs(cxt));
+}
+
+/**
+ * mnt_context_set_target_prefix:
+ * @cxt: mount context
+ * @path: mountpoint prefix
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_target_prefix(struct libmnt_context *cxt, const char *path)
+{
+	char *p = NULL;
+
+	if (!cxt)
+		return -EINVAL;
+	if (path) {
+		p = strdup(path);
+		if (!p)
+			return -ENOMEM;
+	}
+	free(cxt->tgt_prefix);
+	cxt->tgt_prefix = p;
+
+	return 0;
+}
+
+/**
+ * mnt_context_get_target_prefix:
+ * @cxt: mount context
+ *
+ * Returns: returns pointer or NULL in case of error or if not set.
+ */
+const char *mnt_context_get_target_prefix(struct libmnt_context *cxt)
+{
+	return cxt ? cxt->tgt_prefix : NULL;
+}
+
+
+/**
+ * mnt_context_set_fstype:
+ * @cxt: mount context
+ * @fstype: filesystem type
+ *
+ * Note that the @fstype has to be a FS type. For patterns with
+ * comma-separated list of filesystems or for the "nofs" notation, use
+ * mnt_context_set_fstype_pattern().
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_fstype(struct libmnt_context *cxt, const char *fstype)
+{
+	return mnt_fs_set_fstype(mnt_context_get_fs(cxt), fstype);
+}
+
+/**
+ * mnt_context_get_fstype:
+ * @cxt: mount context
+ *
+ * Returns: pointer or NULL in case of error or if not set.
+ */
+const char *mnt_context_get_fstype(struct libmnt_context *cxt)
+{
+	return mnt_fs_get_fstype(mnt_context_get_fs(cxt));
+}
+
+/**
+ * mnt_context_set_options:
+ * @cxt: mount context
+ * @optstr: comma delimited mount options
+ *
+ * Note that MS_MOVE cannot be specified as "string". It's operation that
+ * is no supported in fstab (etc.)
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_options(struct libmnt_context *cxt, const char *optstr)
+{
+	return mnt_fs_set_options(mnt_context_get_fs(cxt), optstr);
+}
+
+/**
+ * mnt_context_append_options:
+ * @cxt: mount context
+ * @optstr: comma delimited mount options
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_append_options(struct libmnt_context *cxt, const char *optstr)
+{
+	return mnt_fs_append_options(mnt_context_get_fs(cxt), optstr);
+}
+
+/**
+ * mnt_context_get_options:
+ * @cxt: mount context
+ *
+ * This function returns mount options set by mnt_context_set_options() or
+ * mnt_context_append_options().
+ *
+ * Note that *after* mnt_context_prepare_mount(), the mount options string
+ * may also include options set by mnt_context_set_mflags() or other options
+ * generated by this library.
+ *
+ * Returns: pointer or NULL
+ */
+const char *mnt_context_get_options(struct libmnt_context *cxt)
+{
+	return mnt_fs_get_options(mnt_context_get_fs(cxt));
+}
+
+/**
+ * mnt_context_set_fstype_pattern:
+ * @cxt: mount context
+ * @pattern: FS name pattern (or NULL to reset the current setting)
+ *
+ * See mount(8), option -t.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_fstype_pattern(struct libmnt_context *cxt, const char *pattern)
+{
+	char *p = NULL;
+
+	if (!cxt)
+		return -EINVAL;
+	if (pattern) {
+		p = strdup(pattern);
+		if (!p)
+			return -ENOMEM;
+	}
+	free(cxt->fstype_pattern);
+	cxt->fstype_pattern = p;
+	return 0;
+}
+
+/**
+ * mnt_context_set_options_pattern:
+ * @cxt: mount context
+ * @pattern: options pattern (or NULL to reset the current setting)
+ *
+ * See mount(8), option -O.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_options_pattern(struct libmnt_context *cxt, const char *pattern)
+{
+	char *p = NULL;
+
+	if (!cxt)
+		return -EINVAL;
+	if (pattern) {
+		p = strdup(pattern);
+		if (!p)
+			return -ENOMEM;
+	}
+	free(cxt->optstr_pattern);
+	cxt->optstr_pattern = p;
+	return 0;
+}
+
+/**
+ * mnt_context_set_fstab:
+ * @cxt: mount context
+ * @tb: fstab
+ *
+ * The mount context reads /etc/fstab to the private struct libmnt_table by default.
+ * This function can be used to overwrite the private fstab with an external
+ * instance.
+ *
+ * This function modify the @tb reference counter. This function does not set
+ * the cache for the @tb. You have to explicitly call mnt_table_set_cache(tb,
+ * mnt_context_get_cache(cxt));
+ *
+ * The fstab is used read-only and is not modified, it should be possible to
+ * share the fstab between more mount contexts (TODO: test it.)
+ *
+ * If the @tb argument is NULL, then the current private fstab instance is
+ * reset.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_fstab(struct libmnt_context *cxt, struct libmnt_table *tb)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	mnt_ref_table(tb);		/* new */
+	mnt_unref_table(cxt->fstab);	/* old */
+
+	cxt->fstab = tb;
+	return 0;
+}
+
+/**
+ * mnt_context_get_fstab:
+ * @cxt: mount context
+ * @tb: returns fstab
+ *
+ * See also mnt_table_parse_fstab() for more details about fstab.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_get_fstab(struct libmnt_context *cxt, struct libmnt_table **tb)
+{
+	struct libmnt_ns *ns_old;
+
+	if (!cxt)
+		return -EINVAL;
+	if (!cxt->fstab) {
+		int rc;
+
+		cxt->fstab = mnt_new_table();
+		if (!cxt->fstab)
+			return -ENOMEM;
+		if (cxt->table_errcb)
+			mnt_table_set_parser_errcb(cxt->fstab, cxt->table_errcb);
+
+		ns_old = mnt_context_switch_target_ns(cxt);
+		if (!ns_old)
+			return -MNT_ERR_NAMESPACE;
+
+		mnt_table_set_cache(cxt->fstab, mnt_context_get_cache(cxt));
+		rc = mnt_table_parse_fstab(cxt->fstab, NULL);
+
+		if (!mnt_context_switch_ns(cxt, ns_old))
+			return -MNT_ERR_NAMESPACE;
+
+		if (rc)
+			return rc;
+	}
+
+	if (tb)
+		*tb = cxt->fstab;
+	return 0;
+}
+
+/**
+ * mnt_context_get_mtab:
+ * @cxt: mount context
+ * @tb: returns mtab
+ *
+ * See also mnt_table_parse_mtab() for more details about mtab/mountinfo. The
+ * result will be deallocated by mnt_free_context(@cxt).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_get_mtab(struct libmnt_context *cxt, struct libmnt_table **tb)
+{
+	int rc = 0;
+	struct libmnt_ns *ns_old = NULL;
+
+	if (!cxt)
+		return -EINVAL;
+	if (!cxt->mtab) {
+		ns_old = mnt_context_switch_target_ns(cxt);
+		if (!ns_old)
+			return -MNT_ERR_NAMESPACE;
+
+		context_init_paths(cxt, 0);
+
+		cxt->mtab = mnt_new_table();
+		if (!cxt->mtab) {
+			rc = -ENOMEM;
+			goto end;
+		}
+
+		if (cxt->table_errcb)
+			mnt_table_set_parser_errcb(cxt->mtab, cxt->table_errcb);
+		if (cxt->table_fltrcb)
+			mnt_table_set_parser_fltrcb(cxt->mtab,
+					cxt->table_fltrcb,
+					cxt->table_fltrcb_data);
+
+		mnt_table_set_cache(cxt->mtab, mnt_context_get_cache(cxt));
+
+		/*
+		 * Note that mtab_path is NULL if mtab is useless or unsupported
+		 */
+		if (cxt->utab)
+			/* utab already parsed, don't parse it again */
+			rc = __mnt_table_parse_mtab(cxt->mtab,
+						    cxt->mtab_path, cxt->utab);
+		else
+			rc = mnt_table_parse_mtab(cxt->mtab, cxt->mtab_path);
+		if (rc)
+			goto end;
+	}
+
+	if (tb)
+		*tb = cxt->mtab;
+
+	DBG(CXT, ul_debugobj(cxt, "mtab requested [nents=%d]",
+				mnt_table_get_nents(cxt->mtab)));
+
+end:
+	if (ns_old && !mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/*
+ * Called by mtab parser to filter out entries, non-zero means that
+ * an entry has to be filtered out.
+ */
+static int mtab_filter(struct libmnt_fs *fs, void *data)
+{
+	if (!fs || !data)
+		return 0;
+	if (mnt_fs_streq_target(fs, data))
+		return 0;
+	if (mnt_fs_streq_srcpath(fs, data))
+		return 0;
+	return 1;
+}
+
+/*
+ * The same like mnt_context_get_mtab(), but does not read all mountinfo/mtab
+ * file, but only entries relevant for @tgt.
+ */
+int mnt_context_get_mtab_for_target(struct libmnt_context *cxt,
+				    struct libmnt_table **mtab,
+				    const char *tgt)
+{
+	struct stat st;
+	struct libmnt_cache *cache = NULL;
+	char *cn_tgt = NULL;
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	if (mnt_context_is_nocanonicalize(cxt))
+		mnt_context_set_tabfilter(cxt, mtab_filter, (void *) tgt);
+
+	else if (mnt_stat_mountpoint(tgt, &st) == 0 && S_ISDIR(st.st_mode)) {
+		cache = mnt_context_get_cache(cxt);
+		cn_tgt = mnt_resolve_path(tgt, cache);
+		if (cn_tgt)
+			mnt_context_set_tabfilter(cxt, mtab_filter, cn_tgt);
+	}
+
+	rc = mnt_context_get_mtab(cxt, mtab);
+	mnt_context_set_tabfilter(cxt, NULL, NULL);
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	if (cn_tgt && !cache)
+		free(cn_tgt);
+
+	return rc;
+}
+
+/*
+ * Allows to specify a filter for tab file entries. The filter is called by
+ * the table parser. Currently used for mtab and utab only.
+ */
+int mnt_context_set_tabfilter(struct libmnt_context *cxt,
+			      int (*fltr)(struct libmnt_fs *, void *),
+			      void *data)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	cxt->table_fltrcb = fltr;
+	cxt->table_fltrcb_data = data;
+
+	if (cxt->mtab)
+		mnt_table_set_parser_fltrcb(cxt->mtab,
+				cxt->table_fltrcb,
+				cxt->table_fltrcb_data);
+
+	DBG(CXT, ul_debugobj(cxt, "tabfilter %s", fltr ? "ENABLED!" : "disabled"));
+	return 0;
+}
+
+/**
+ * mnt_context_get_table:
+ * @cxt: mount context
+ * @filename: e.g. /proc/self/mountinfo
+ * @tb: returns the table
+ *
+ * This function allocates a new table and parses the @file. The parser error
+ * callback and cache for tags and paths is set according to the @cxt setting.
+ * See also mnt_table_parse_file().
+ *
+ * It's strongly recommended to use the mnt_context_get_mtab() and
+ * mnt_context_get_fstab() functions for mtab and fstab files. This function
+ * does not care about LIBMOUNT_* env.variables and does not merge userspace
+ * options.
+ *
+ * The result will NOT be deallocated by mnt_free_context(@cxt).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_get_table(struct libmnt_context *cxt,
+			  const char *filename, struct libmnt_table **tb)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	if (!cxt || !tb)
+		return -EINVAL;
+
+	*tb = mnt_new_table();
+	if (!*tb)
+		return -ENOMEM;
+
+	if (cxt->table_errcb)
+		mnt_table_set_parser_errcb(*tb, cxt->table_errcb);
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	rc = mnt_table_parse_file(*tb, filename);
+
+	if (rc) {
+		mnt_unref_table(*tb);
+		goto end;
+	}
+
+	mnt_table_set_cache(*tb, mnt_context_get_cache(cxt));
+
+end:
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/**
+ * mnt_context_set_tables_errcb
+ * @cxt: mount context
+ * @cb: pointer to callback function
+ *
+ * The error callback is used for all tab files (e.g. mtab, fstab)
+ * parsed within the context.
+ *
+ * See also mnt_context_get_mtab(),
+ *          mnt_context_get_fstab(),
+ *          mnt_table_set_parser_errcb().
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_tables_errcb(struct libmnt_context *cxt,
+	int (*cb)(struct libmnt_table *tb, const char *filename, int line))
+{
+	if (!cxt)
+		return -EINVAL;
+
+	if (cxt->mtab)
+		mnt_table_set_parser_errcb(cxt->mtab, cb);
+	if (cxt->fstab)
+		mnt_table_set_parser_errcb(cxt->fstab, cb);
+
+	cxt->table_errcb = cb;
+	return 0;
+}
+
+/**
+ * mnt_context_set_cache:
+ * @cxt: mount context
+ * @cache: cache instance or NULL
+ *
+ * The mount context maintains a private struct libmnt_cache by default. This
+ * function can be used to overwrite the private cache with an external instance.
+ * This function increments cache reference counter.
+ *
+ * If the @cache argument is NULL, then the current cache instance is reset.
+ * This function apply the cache to fstab and mtab instances (if already
+ * exists).
+ *
+ * The old cache instance reference counter is de-incremented.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_cache(struct libmnt_context *cxt, struct libmnt_cache *cache)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	mnt_ref_cache(cache);			/* new */
+	mnt_unref_cache(cxt->cache);		/* old */
+
+	cxt->cache = cache;
+
+	if (cxt->mtab)
+		mnt_table_set_cache(cxt->mtab, cache);
+	if (cxt->fstab)
+		mnt_table_set_cache(cxt->fstab, cache);
+
+	return 0;
+}
+
+/**
+ * mnt_context_get_cache
+ * @cxt: mount context
+ *
+ * See also mnt_context_set_cache().
+ *
+ * Returns: pointer to cache or NULL if canonicalization is disabled.
+ */
+struct libmnt_cache *mnt_context_get_cache(struct libmnt_context *cxt)
+{
+	if (!cxt || mnt_context_is_nocanonicalize(cxt))
+		return NULL;
+
+	if (!cxt->cache) {
+		struct libmnt_cache *cache = mnt_new_cache();
+		mnt_context_set_cache(cxt, cache);
+		mnt_unref_cache(cache);
+	}
+	return cxt->cache;
+}
+
+/**
+ * mnt_context_set_passwd_cb:
+ * @cxt: mount context
+ * @get: callback to get password
+ * @release: callback to release (deallocate) password
+ *
+ * Sets callbacks for encryption password (e.g encrypted loopdev). This
+ * function is deprecated (encrypted loops are no longer supported).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_passwd_cb(struct libmnt_context *cxt,
+			      char *(*get)(struct libmnt_context *),
+			      void (*release)(struct libmnt_context *, char *))
+{
+	if (!cxt)
+		return -EINVAL;
+	cxt->pwd_get_cb = get;
+	cxt->pwd_release_cb = release;
+	return 0;
+}
+
+/**
+ * mnt_context_get_lock:
+ * @cxt: mount context
+ *
+ * The libmount applications don't have to care about mtab locking, but with a
+ * small exception: the application has to be able to remove the lock file when
+ * interrupted by signal or signals have to be ignored when the lock is locked.
+ *
+ * The default behavior is to ignore all signals (except SIGALRM and
+ * SIGTRAP for mtab update) when the lock is locked. If this behavior
+ * is unacceptable, then use:
+ *
+ *	lc = mnt_context_get_lock(cxt);
+ *	if (lc)
+ *		mnt_lock_block_signals(lc, FALSE);
+ *
+ * and don't forget to call mnt_unlock_file(lc) before exit.
+ *
+ * Returns: pointer to lock struct or NULL.
+ */
+struct libmnt_lock *mnt_context_get_lock(struct libmnt_context *cxt)
+{
+	/*
+	 * DON'T call this function within libmount, it will always allocate
+	 * the lock. The mnt_update_* functions are able to allocate the lock
+	 * only when mtab/utab update is really necessary.
+	 */
+	if (!cxt || mnt_context_is_nomtab(cxt))
+		return NULL;
+
+	if (!cxt->lock) {
+		cxt->lock = mnt_new_lock(
+				mnt_context_get_writable_tabpath(cxt), 0);
+		if (cxt->lock)
+			mnt_lock_block_signals(cxt->lock, TRUE);
+	}
+	return cxt->lock;
+}
+
+/**
+ * mnt_context_set_mflags:
+ * @cxt: mount context
+ * @flags: mount(2) flags (MS_* flags)
+ *
+ * Sets mount flags (see mount(2) man page).
+ *
+ * Note that mount context can be used to define mount options by mount flags. It
+ * means you can for example use
+ *
+ *	mnt_context_set_mflags(cxt, MS_NOEXEC | MS_NOSUID);
+ *
+ * rather than
+ *
+ *	mnt_context_set_options(cxt, "noexec,nosuid");
+ *
+ * both of these calls have the same effect.
+ *
+ * Be careful if you want to use MS_REC flag -- in this case the bit is applied
+ * to all bind/slave/etc. options. If you want to mix more propadation flags
+ * and/or bind operations than it's better to specify mount options by
+ * strings.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_mflags(struct libmnt_context *cxt, unsigned long flags)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	cxt->mountflags = flags;
+
+	if ((cxt->flags & MNT_FL_MOUNTOPTS_FIXED) && cxt->fs)
+		/*
+		 * the final mount options are already generated, refresh...
+		 */
+		return mnt_optstr_apply_flags(
+				&cxt->fs->vfs_optstr,
+				cxt->mountflags,
+				mnt_get_builtin_optmap(MNT_LINUX_MAP));
+
+	return 0;
+}
+
+/**
+ * mnt_context_get_mflags:
+ * @cxt: mount context
+ * @flags: returns MS_* mount flags
+ *
+ * Converts mount options string to MS_* flags and bitwise-OR the result with
+ * the already defined flags (see mnt_context_set_mflags()).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_get_mflags(struct libmnt_context *cxt, unsigned long *flags)
+{
+	int rc = 0;
+	struct list_head *p;
+
+	if (!cxt || !flags)
+		return -EINVAL;
+
+	*flags = 0;
+	if (!(cxt->flags & MNT_FL_MOUNTFLAGS_MERGED) && cxt->fs) {
+		const char *o = mnt_fs_get_options(cxt->fs);
+		if (o)
+			rc = mnt_optstr_get_flags(o, flags,
+				    mnt_get_builtin_optmap(MNT_LINUX_MAP));
+	}
+
+	list_for_each(p, &cxt->addmounts) {
+		struct libmnt_addmount *ad =
+				list_entry(p, struct libmnt_addmount, mounts);
+
+		*flags |= ad->mountflags;
+	}
+
+	if (!rc)
+		*flags |= cxt->mountflags;
+	return rc;
+}
+
+/**
+ * mnt_context_set_user_mflags:
+ * @cxt: mount context
+ * @flags: mount(2) flags (MNT_MS_* flags, e.g. MNT_MS_LOOP)
+ *
+ * Sets userspace mount flags.
+ *
+ * See also notes for mnt_context_set_mflags().
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_user_mflags(struct libmnt_context *cxt, unsigned long flags)
+{
+	if (!cxt)
+		return -EINVAL;
+	cxt->user_mountflags = flags;
+	return 0;
+}
+
+/**
+ * mnt_context_get_user_mflags:
+ * @cxt: mount context
+ * @flags: returns mount flags
+ *
+ * Converts mount options string to MNT_MS_* flags and bitwise-OR the result
+ * with the already defined flags (see mnt_context_set_user_mflags()).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_get_user_mflags(struct libmnt_context *cxt, unsigned long *flags)
+{
+	int rc = 0;
+
+	if (!cxt || !flags)
+		return -EINVAL;
+
+	*flags = 0;
+	if (!(cxt->flags & MNT_FL_MOUNTFLAGS_MERGED) && cxt->fs) {
+		const char *o = mnt_fs_get_user_options(cxt->fs);
+		if (o)
+			rc = mnt_optstr_get_flags(o, flags,
+				mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
+	}
+	if (!rc)
+		*flags |= cxt->user_mountflags;
+	return rc;
+}
+
+/**
+ * mnt_context_set_mountdata:
+ * @cxt: mount context
+ * @data: mount(2) data
+ *
+ * The mount context generates mountdata from mount options by default. This
+ * function can be used to overwrite this behavior, and @data will be used instead
+ * of mount options.
+ *
+ * The libmount does not deallocate the data by mnt_free_context(). Note that
+ * NULL is also valid mount data.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_set_mountdata(struct libmnt_context *cxt, void *data)
+{
+	if (!cxt)
+		return -EINVAL;
+	cxt->mountdata = data;
+	cxt->flags |= MNT_FL_MOUNTDATA;
+	return 0;
+}
+
+/*
+ * Translates LABEL/UUID/path to mountable path
+ */
+int mnt_context_prepare_srcpath(struct libmnt_context *cxt)
+{
+	const char *path = NULL;
+	struct libmnt_cache *cache;
+	const char *t, *v, *src;
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "preparing source path"));
+
+	src = mnt_fs_get_source(cxt->fs);
+
+	if (!src && mnt_context_propagation_only(cxt))
+		/* mount --make-{shared,private,...} */
+		return mnt_fs_set_source(cxt->fs, "none");
+
+	/* ignore filesystems without source or filesystems
+	 * where the source is a quasi-path (//foo/bar)
+	 */
+	if (!src || mnt_fs_is_netfs(cxt->fs))
+		return 0;
+
+	DBG(CXT, ul_debugobj(cxt, "srcpath '%s'", src));
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	cache = mnt_context_get_cache(cxt);
+
+	if (!mnt_fs_get_tag(cxt->fs, &t, &v)) {
+		/*
+		 * Source is TAG (evaluate)
+		 */
+		if (cache)
+			path = mnt_resolve_tag(t, v, cache);
+
+		rc = path ? mnt_fs_set_source(cxt->fs, path) : -MNT_ERR_NOSOURCE;
+
+	} else if (cache && !mnt_fs_is_pseudofs(cxt->fs)) {
+		/*
+		 * Source is PATH (canonicalize)
+		 */
+		path = mnt_resolve_path(src, cache);
+		if (path && strcmp(path, src) != 0)
+			rc = mnt_fs_set_source(cxt->fs, path);
+	 }
+
+	if (rc) {
+		DBG(CXT, ul_debugobj(cxt, "failed to prepare srcpath [rc=%d]", rc));
+		goto end;
+	}
+
+	if (!path)
+		path = src;
+
+	if ((cxt->mountflags & (MS_BIND | MS_MOVE | MS_REMOUNT))
+	    || mnt_fs_is_pseudofs(cxt->fs)) {
+		DBG(CXT, ul_debugobj(cxt, "REMOUNT/BIND/MOVE/pseudo FS source: %s", path));
+		goto end;
+	}
+
+
+	/*
+	 * Initialize verity or loop device
+	 * ENOTSUP means verity options were requested, but the library is built without
+	 * libcryptsetup so integrity cannot be enforced, and this should be an error
+	 * rather than a silent fallback to a simple loopdev mount
+	 */
+	rc = mnt_context_is_veritydev(cxt);
+	if (rc == -ENOTSUP) {
+			goto end;
+	} else if (rc) {
+		rc = mnt_context_setup_veritydev(cxt);
+		if (rc)
+			goto end;
+	} else if (mnt_context_is_loopdev(cxt)) {
+		rc = mnt_context_setup_loopdev(cxt);
+		if (rc)
+			goto end;
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "final srcpath '%s'",
+				mnt_fs_get_source(cxt->fs)));
+
+end:
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+static int is_mkdir_required(const char *tgt, struct libmnt_fs *fs, mode_t *mode, int *rc)
+{
+	char *mstr = NULL;
+	size_t mstr_sz = 0;
+	struct stat st;
+
+	assert(tgt);
+	assert(fs);
+	assert(mode);
+	assert(rc);
+
+	*mode = 0;
+	*rc = 0;
+
+	if (mnt_optstr_get_option(fs->user_optstr, "X-mount.mkdir", &mstr, &mstr_sz) != 0 &&
+	    mnt_optstr_get_option(fs->user_optstr, "x-mount.mkdir", &mstr, &mstr_sz) != 0)   	/* obsolete */
+		return 0;
+
+	if (mnt_stat_mountpoint(tgt, &st) == 0)
+		return 0;
+
+	DBG(CXT, ul_debug("mkdir %s (%s) wanted", tgt, mstr));
+
+	if (mstr && mstr_sz) {
+		char *end = NULL;
+
+		errno = 0;
+		*mode = strtol(mstr, &end, 8);
+
+		if (errno || !end || mstr + mstr_sz != end) {
+			DBG(CXT, ul_debug("failed to parse mkdir mode '%s'", mstr));
+			*rc = -MNT_ERR_MOUNTOPT;
+			return 0;
+		}
+	}
+
+	if (!*mode)
+		*mode = S_IRWXU |			/* 0755 */
+		       S_IRGRP | S_IXGRP |
+		       S_IROTH | S_IXOTH;
+
+	return 1;
+}
+
+int mnt_context_prepare_target(struct libmnt_context *cxt)
+{
+	const char *tgt, *prefix;
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+	mode_t mode = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "preparing target path"));
+
+	tgt = mnt_fs_get_target(cxt->fs);
+	if (!tgt)
+		return 0;
+
+	/* apply prefix */
+	prefix = mnt_context_get_target_prefix(cxt);
+	if (prefix) {
+		const char *p = *tgt == '/' ? tgt + 1 : tgt;
+
+		if (!*p)
+			/* target is "/", use "/prefix" */
+			rc = mnt_fs_set_target(cxt->fs, prefix);
+		else {
+			char *path = NULL;
+
+			if (asprintf(&path, "%s/%s", prefix, p) <= 0)
+				rc = -ENOMEM;
+			else {
+				rc = mnt_fs_set_target(cxt->fs, path);
+				free(path);
+			}
+		}
+		if (rc)
+			return rc;
+		tgt = mnt_fs_get_target(cxt->fs);
+	}
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	/* X-mount.mkdir target */
+	if (cxt->action == MNT_ACT_MOUNT
+	    && (cxt->user_mountflags & MNT_MS_XCOMMENT ||
+		cxt->user_mountflags & MNT_MS_XFSTABCOMM)
+	    && is_mkdir_required(tgt, cxt->fs, &mode, &rc)) {
+
+		/* supported only for root or non-suid mount(8) */
+		if (!mnt_context_is_restricted(cxt)) {
+			rc = mkdir_p(tgt, mode);
+			if (rc)
+				DBG(CXT, ul_debug("mkdir %s failed: %m", tgt));
+		} else
+			rc = -EPERM;
+	}
+
+	/* canonicalize the path */
+	if (rc == 0) {
+		struct libmnt_cache *cache = mnt_context_get_cache(cxt);
+
+		if (cache) {
+			char *path = mnt_resolve_path(tgt, cache);
+			if (path && strcmp(path, tgt) != 0)
+				rc = mnt_fs_set_target(cxt->fs, path);
+		}
+	}
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	DBG(CXT, ul_debugobj(cxt, "final target '%s' [rc=%d]",
+				mnt_fs_get_target(cxt->fs), rc));
+	return rc;
+}
+
+/* Guess type, but not set to cxt->fs, always use free() for the result. It's
+ * no error when we're not able to guess a filesystem type. Note that error
+ * does not mean that result in @type is NULL.
+ */
+int mnt_context_guess_srcpath_fstype(struct libmnt_context *cxt, char **type)
+{
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+	const char *dev;
+
+	assert(type);
+	assert(cxt);
+
+	*type = NULL;
+
+	dev = mnt_fs_get_srcpath(cxt->fs);
+	if (!dev)
+		return 0;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	if (access(dev, F_OK) == 0) {
+		struct libmnt_cache *cache = mnt_context_get_cache(cxt);
+		int ambi = 0;
+
+		*type = mnt_get_fstype(dev, &ambi, cache);
+		if (ambi)
+			rc = -MNT_ERR_AMBIFS;
+
+		if (cache && *type) {
+			*type = strdup(*type);
+			if (!*type)
+				rc = -ENOMEM;
+		}
+	} else {
+		DBG(CXT, ul_debugobj(cxt, "access(%s) failed [%m]", dev));
+		if (strchr(dev, ':') != NULL) {
+			*type = strdup("nfs");
+			if (!*type)
+				rc = -ENOMEM;
+		} else if (!strncmp(dev, "//", 2)) {
+			*type = strdup("cifs");
+			if (!*type)
+				rc = -ENOMEM;
+		}
+	}
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/*
+ * It's usually no error when we're not able to detect the filesystem type -- we
+ * will try to use the types from /{etc,proc}/filesystems.
+ */
+int mnt_context_guess_fstype(struct libmnt_context *cxt)
+{
+	char *type;
+	int rc = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "preparing fstype"));
+
+	if ((cxt->mountflags & (MS_BIND | MS_MOVE))
+	    || mnt_context_propagation_only(cxt))
+		goto none;
+
+	type = (char *) mnt_fs_get_fstype(cxt->fs);
+	if (type && !strcmp(type, "auto")) {
+		mnt_fs_set_fstype(cxt->fs, NULL);
+		type = NULL;
+	}
+
+	if (type)
+		goto done;
+	if (cxt->mountflags & MS_REMOUNT)
+		goto none;
+	if (cxt->fstype_pattern)
+		goto done;
+
+	rc = mnt_context_guess_srcpath_fstype(cxt, &type);
+	if (rc == 0 && type)
+		__mnt_fs_set_fstype_ptr(cxt->fs, type);
+	else
+		free(type);
+done:
+	DBG(CXT, ul_debugobj(cxt, "FS type: %s [rc=%d]",
+				mnt_fs_get_fstype(cxt->fs), rc));
+	return rc;
+none:
+	return mnt_fs_set_fstype(cxt->fs, "none");
+}
+
+/*
+ * The default is to use fstype from cxt->fs, this could be overwritten by
+ * @type. The @act is MNT_ACT_{MOUNT,UMOUNT}.
+ *
+ * Returns: 0 on success or negative number in case of error. Note that success
+ * does not mean that there is any usable helper, you have to check cxt->helper.
+ */
+int mnt_context_prepare_helper(struct libmnt_context *cxt, const char *name,
+				const char *type)
+{
+	char search_path[] = FS_SEARCH_PATH;		/* from config.h */
+	char *p = NULL, *path;
+	struct libmnt_ns *ns_old;
+	int rc = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!type)
+		type = mnt_fs_get_fstype(cxt->fs);
+
+	if (type && strchr(type, ','))
+		return 0;			/* type is fstype pattern */
+
+	if (mnt_context_is_nohelpers(cxt)
+	    || !type
+	    || !strcmp(type, "none")
+	    || strstr(type, "/..")		/* don't try to smuggle path */
+	    || mnt_fs_is_swaparea(cxt->fs))
+		return 0;
+
+	ns_old = mnt_context_switch_origin_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	/* Ignore errors when search in $PATH and do not modify
+	 * @rc due to stat() etc.
+	 */
+	path = strtok_r(search_path, ":", &p);
+	while (path) {
+		char helper[PATH_MAX];
+		struct stat st;
+		int xrc;
+
+		xrc = snprintf(helper, sizeof(helper), "%s/%s.%s",
+						path, name, type);
+		path = strtok_r(NULL, ":", &p);
+
+		if (xrc < 0 || (size_t) xrc >= sizeof(helper))
+			continue;
+
+		xrc = stat(helper, &st);
+		if (xrc == -1 && errno == ENOENT && strchr(type, '.')) {
+			/* If type ends with ".subtype" try without it */
+			char *hs = strrchr(helper, '.');
+			if (hs)
+				*hs = '\0';
+			xrc = stat(helper, &st);
+		}
+
+		DBG(CXT, ul_debugobj(cxt, "%-25s ... %s", helper,
+					xrc ? "not found" : "found"));
+		if (xrc)
+			continue;
+
+		/* success */
+		rc = strdup_to_struct_member(cxt, helper, helper);
+		break;
+	}
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		rc = -MNT_ERR_NAMESPACE;
+
+	/* make sure helper is not set on error */
+	if (rc) {
+		free(cxt->helper);
+		cxt->helper = NULL;
+	}
+	return rc;
+}
+
+int mnt_context_merge_mflags(struct libmnt_context *cxt)
+{
+	unsigned long fl = 0;
+	int rc;
+
+	assert(cxt);
+
+	DBG(CXT, ul_debugobj(cxt, "merging mount flags"));
+
+	rc = mnt_context_get_mflags(cxt, &fl);
+	if (rc)
+		return rc;
+	cxt->mountflags = fl;
+
+	fl = 0;
+	rc = mnt_context_get_user_mflags(cxt, &fl);
+	if (rc)
+		return rc;
+	cxt->user_mountflags = fl;
+
+	DBG(CXT, ul_debugobj(cxt, "final flags: VFS=%08lx user=%08lx",
+			cxt->mountflags, cxt->user_mountflags));
+
+	cxt->flags |= MNT_FL_MOUNTFLAGS_MERGED;
+	return 0;
+}
+
+/*
+ * Prepare /etc/mtab or /run/mount/utab
+ */
+int mnt_context_prepare_update(struct libmnt_context *cxt)
+{
+	int rc;
+	const char *target;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->action);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "prepare update"));
+
+	if (mnt_context_propagation_only(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "skip update: only MS_PROPAGATION"));
+		return 0;
+	}
+
+	target = mnt_fs_get_target(cxt->fs);
+
+	if (cxt->action == MNT_ACT_UMOUNT && target && !strcmp(target, "/")) {
+		DBG(CXT, ul_debugobj(cxt, "root umount: setting NOMTAB"));
+		mnt_context_disable_mtab(cxt, TRUE);
+	}
+	if (mnt_context_is_nomtab(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "skip update: NOMTAB flag"));
+		return 0;
+	}
+	if (!mnt_context_get_writable_tabpath(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "skip update: no writable destination"));
+		return 0;
+	}
+	/* 0 = success, 1 = not called yet */
+	if (cxt->syscall_status != 1 && cxt->syscall_status != 0) {
+		DBG(CXT, ul_debugobj(cxt,
+				"skip update: syscall failed [status=%d]",
+				cxt->syscall_status));
+		return 0;
+	}
+
+	if (!cxt->update) {
+		const char *name = mnt_context_get_writable_tabpath(cxt);
+
+		if (cxt->action == MNT_ACT_UMOUNT && is_file_empty(name)) {
+			DBG(CXT, ul_debugobj(cxt,
+				"skip update: umount, no table"));
+			return 0;
+		}
+
+		cxt->update = mnt_new_update();
+		if (!cxt->update)
+			return -ENOMEM;
+
+		mnt_update_set_filename(cxt->update, name,
+				!mnt_context_mtab_writable(cxt));
+	}
+
+	if (cxt->action == MNT_ACT_UMOUNT)
+		rc = mnt_update_set_fs(cxt->update, cxt->mountflags,
+					mnt_context_get_target(cxt), NULL);
+	else
+		rc = mnt_update_set_fs(cxt->update, cxt->mountflags,
+					NULL, cxt->fs);
+
+	return rc < 0 ? rc : 0;
+}
+
+int mnt_context_update_tabs(struct libmnt_context *cxt)
+{
+	unsigned long fl;
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+
+	if (mnt_context_is_nomtab(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "don't update: NOMTAB flag"));
+		return 0;
+	}
+	if (!cxt->update || !mnt_update_is_ready(cxt->update)) {
+		DBG(CXT, ul_debugobj(cxt, "don't update: no update prepared"));
+		return 0;
+	}
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	/* check utab update when external helper executed */
+	if (mnt_context_helper_executed(cxt)
+	    && mnt_context_get_helper_status(cxt) == 0
+	    && mnt_context_utab_writable(cxt)) {
+
+		if (mnt_update_already_done(cxt->update, cxt->lock)) {
+			DBG(CXT, ul_debugobj(cxt, "don't update: error evaluate or already updated"));
+			goto end;
+		}
+	} else if (cxt->helper) {
+		DBG(CXT, ul_debugobj(cxt, "don't update: external helper"));
+		goto end;
+	}
+
+	if (cxt->syscall_status != 0
+	    && !(mnt_context_helper_executed(cxt) &&
+		 mnt_context_get_helper_status(cxt) == 0)) {
+
+		DBG(CXT, ul_debugobj(cxt, "don't update: syscall/helper failed/not called"));
+		goto end;
+	}
+
+	fl = mnt_update_get_mflags(cxt->update);
+	if ((cxt->mountflags & MS_RDONLY) != (fl & MS_RDONLY))
+		/*
+		 * fix MS_RDONLY in options
+		 */
+		mnt_update_force_rdonly(cxt->update,
+				cxt->mountflags & MS_RDONLY);
+
+	rc = mnt_update_table(cxt->update, cxt->lock);
+
+end:
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+/* apply @fs to @cxt -- use mnt_context_apply_fstab() if not sure
+ */
+int mnt_context_apply_fs(struct libmnt_context *cxt, struct libmnt_fs *fs)
+{
+	int rc;
+
+	if (!cxt->optsmode) {
+		if (mnt_context_is_restricted(cxt)) {
+			DBG(CXT, ul_debugobj(cxt, "force fstab usage for non-root users!"));
+			cxt->optsmode = MNT_OMODE_USER;
+		} else {
+			DBG(CXT, ul_debugobj(cxt, "use default optsmode"));
+			cxt->optsmode = MNT_OMODE_AUTO;
+		}
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "apply entry:"));
+	DBG(CXT, mnt_fs_print_debug(fs, stderr));
+	DBG(CXT, ul_debugobj(cxt, "OPTSMODE (opt-part): ignore=%d, append=%d, prepend=%d, replace=%d",
+				  cxt->optsmode & MNT_OMODE_IGNORE ? 1 : 0,
+				  cxt->optsmode & MNT_OMODE_APPEND ? 1 : 0,
+				  cxt->optsmode & MNT_OMODE_PREPEND ? 1 : 0,
+				  cxt->optsmode & MNT_OMODE_REPLACE ? 1 : 0));
+
+	/* copy from fs to our FS description
+	 */
+	rc = mnt_fs_set_source(cxt->fs, mnt_fs_get_source(fs));
+	if (!rc)
+		rc = mnt_fs_set_target(cxt->fs, mnt_fs_get_target(fs));
+
+	if (!rc && !mnt_fs_get_fstype(cxt->fs))
+		rc = mnt_fs_set_fstype(cxt->fs, mnt_fs_get_fstype(fs));
+
+	if (!rc && !mnt_fs_get_root(cxt->fs) && mnt_fs_get_root(fs))
+		rc = mnt_fs_set_root(cxt->fs, mnt_fs_get_root(fs));
+
+	if (rc)
+		goto done;
+
+	if (cxt->optsmode & MNT_OMODE_IGNORE)
+		;
+	else if (cxt->optsmode & MNT_OMODE_REPLACE)
+		rc = mnt_fs_set_options(cxt->fs, mnt_fs_get_options(fs));
+
+	else if (cxt->optsmode & MNT_OMODE_APPEND)
+		rc = mnt_fs_append_options(cxt->fs, mnt_fs_get_options(fs));
+
+	else if (cxt->optsmode & MNT_OMODE_PREPEND)
+		rc = mnt_fs_prepend_options(cxt->fs, mnt_fs_get_options(fs));
+
+	if (!rc)
+		cxt->flags |= MNT_FL_TAB_APPLIED;
+
+done:
+	DBG(CXT, ul_debugobj(cxt, "final entry [rc=%d]:", rc));
+	DBG(CXT, mnt_fs_print_debug(cxt->fs, stderr));
+
+	return rc;
+}
+
+static int apply_table(struct libmnt_context *cxt, struct libmnt_table *tb,
+		     int direction)
+{
+	struct libmnt_fs *fs = NULL;
+	const char *src, *tgt;
+
+	assert(cxt);
+	assert(cxt->fs);
+
+	src = mnt_fs_get_source(cxt->fs);
+	tgt = mnt_fs_get_target(cxt->fs);
+
+	if (tgt && src)
+		fs = mnt_table_find_pair(tb, src, tgt, direction);
+	else {
+		if (src)
+			fs = mnt_table_find_source(tb, src, direction);
+		else if (tgt)
+			fs = mnt_table_find_target(tb, tgt, direction);
+
+		if (!fs && mnt_context_is_swapmatch(cxt)) {
+			/* swap source and target (if @src is not LABEL/UUID),
+			 * for example in
+			 *
+			 *	mount /foo/bar
+			 *
+			 * the path could be a mountpoint as well as a source (for
+			 * example bind mount, symlink to a device, ...).
+			 */
+			if (src && !mnt_fs_get_tag(cxt->fs, NULL, NULL))
+				fs = mnt_table_find_target(tb, src, direction);
+			if (!fs && tgt)
+				fs = mnt_table_find_source(tb, tgt, direction);
+		}
+	}
+
+	if (!fs)
+		return -MNT_ERR_NOFSTAB;	/* not found */
+
+	return mnt_context_apply_fs(cxt, fs);
+}
+
+/**
+ * mnt_context_apply_fstab:
+ * @cxt: mount context
+ *
+ * This function is optional.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_apply_fstab(struct libmnt_context *cxt)
+{
+	int rc = -1, isremount = 0, iscmdbind = 0;
+	struct libmnt_ns *ns_old;
+	struct libmnt_table *tab = NULL;
+	const char *src = NULL, *tgt = NULL;
+	unsigned long mflags = 0;
+
+	if (!cxt || !cxt->fs)
+		return -EINVAL;
+
+	if (mnt_context_tab_applied(cxt)) {	/* already applied */
+		DBG(CXT, ul_debugobj(cxt, "fstab already applied -- skip"));
+		return 0;
+	}
+
+	if (mnt_context_is_restricted(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "force fstab usage for non-root users!"));
+		cxt->optsmode = MNT_OMODE_USER;
+	} else if (cxt->optsmode == 0) {
+		DBG(CXT, ul_debugobj(cxt, "use default optsmode"));
+		cxt->optsmode = MNT_OMODE_AUTO;
+	} else if (cxt->optsmode & MNT_OMODE_NOTAB) {
+		cxt->optsmode &= ~MNT_OMODE_FSTAB;
+		cxt->optsmode &= ~MNT_OMODE_MTAB;
+		cxt->optsmode &= ~MNT_OMODE_FORCE;
+	}
+
+	if (mnt_context_get_mflags(cxt, &mflags) == 0) {
+		isremount = !!(mflags & MS_REMOUNT);
+		iscmdbind = !!(mflags & MS_BIND);
+	}
+
+	if (cxt->fs) {
+		src = mnt_fs_get_source(cxt->fs);
+		tgt = mnt_fs_get_target(cxt->fs);
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "OPTSMODE (file-part): force=%d, fstab=%d, mtab=%d",
+				  cxt->optsmode & MNT_OMODE_FORCE ? 1 : 0,
+				  cxt->optsmode & MNT_OMODE_FSTAB ? 1 : 0,
+				  cxt->optsmode & MNT_OMODE_MTAB ? 1 : 0));
+
+	/* fstab is not required if source and target are specified */
+	if (src && tgt && !(cxt->optsmode & MNT_OMODE_FORCE)) {
+		DBG(CXT, ul_debugobj(cxt, "fstab not required -- skip"));
+		return 0;
+	}
+
+	if (!src && tgt
+	    && !(cxt->optsmode & MNT_OMODE_FSTAB)
+	    && !(cxt->optsmode & MNT_OMODE_MTAB)) {
+		DBG(CXT, ul_debugobj(cxt, "only target; fstab/mtab not required "
+					  "-- skip, probably MS_PROPAGATION"));
+		return 0;
+	}
+
+	/* let's initialize cxt->fs */
+	ignore_result( mnt_context_get_fs(cxt) );
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	/* try fstab */
+	if (cxt->optsmode & MNT_OMODE_FSTAB) {
+		DBG(CXT, ul_debugobj(cxt, "trying to apply fstab (src=%s, target=%s)", src, tgt));
+		rc = mnt_context_get_fstab(cxt, &tab);
+		if (!rc)
+			rc = apply_table(cxt, tab, MNT_ITER_FORWARD);
+	}
+
+	/* try mtab */
+	if (rc < 0 && (cxt->optsmode & MNT_OMODE_MTAB)
+	    && (isremount || cxt->action == MNT_ACT_UMOUNT)) {
+		DBG(CXT, ul_debugobj(cxt, "trying to apply mtab (src=%s, target=%s)", src, tgt));
+		if (tgt)
+			rc = mnt_context_get_mtab_for_target(cxt, &tab, tgt);
+		else
+			rc = mnt_context_get_mtab(cxt, &tab);
+		if (!rc)
+			rc = apply_table(cxt, tab, MNT_ITER_BACKWARD);
+	}
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	if (rc) {
+		if (!mnt_context_is_restricted(cxt)
+		    && tgt && !src
+		    && isremount) {
+			DBG(CXT, ul_debugobj(cxt, "only target; ignore missing mtab entry on remount"));
+			return 0;
+		}
+
+		DBG(CXT, ul_debugobj(cxt, "failed to find entry in fstab/mtab [rc=%d]: %m", rc));
+
+		/* force to "not found in fstab/mtab" error, the details why
+		 * not found are not so important and may be misinterpreted by
+		 * applications... */
+		rc = -MNT_ERR_NOFSTAB;
+
+
+	} else if (isremount && !iscmdbind) {
+
+		/* remove "bind" from fstab (or no-op if not present) */
+		mnt_optstr_remove_option(&cxt->fs->optstr, "bind");
+	}
+	return rc;
+}
+
+/**
+ * mnt_context_tab_applied:
+ * @cxt: mount context
+ *
+ * Returns: 1 if fstab (or mtab) has been applied to the context, or 0.
+ */
+int mnt_context_tab_applied(struct libmnt_context *cxt)
+{
+	return cxt->flags & MNT_FL_TAB_APPLIED;
+}
+
+/*
+ * This is not a public function!
+ *
+ * Returns 1 if *only propagation flags* change is requested.
+ */
+int mnt_context_propagation_only(struct libmnt_context *cxt)
+{
+	if (cxt->action != MNT_ACT_MOUNT)
+		return 0;
+
+	/* has to be called after context_mount.c: fix_opts() */
+	assert((cxt->flags & MNT_FL_MOUNTOPTS_FIXED));
+
+	/* all propagation mounts are in cxt->addmount */
+	return !list_empty(&cxt->addmounts)
+	       && (cxt->mountflags == 0 || cxt->mountflags == MS_SILENT)
+	       && cxt->fs
+	       && (!cxt->fs->fstype || strcmp(cxt->fs->fstype, "none") == 0)
+	       && (!cxt->fs->source || strcmp(cxt->fs->source, "none") == 0);
+}
+
+/**
+ * mnt_context_get_status:
+ * @cxt: mount context
+ *
+ * Global libmount status.
+ *
+ * The real exit code of the mount.type helper has to be tested by
+ * mnt_context_get_helper_status(). The mnt_context_get_status() only informs
+ * that exec() has been successful.
+ *
+ * Returns: 1 if mount.type or mount(2) syscall has been successfully called.
+ */
+int mnt_context_get_status(struct libmnt_context *cxt)
+{
+	return !cxt->syscall_status || !cxt->helper_exec_status;
+}
+
+/**
+ * mnt_context_helper_executed:
+ * @cxt: mount context
+ *
+ * Returns: 1 if mount.type helper has been executed, or 0.
+ */
+int mnt_context_helper_executed(struct libmnt_context *cxt)
+{
+	return cxt->helper_exec_status != 1;
+}
+
+/**
+ * mnt_context_get_helper_status:
+ * @cxt: mount context
+ *
+ * Return: mount.type helper exit status, result is reliable only if
+ *         mnt_context_helper_executed() returns 1.
+ */
+int mnt_context_get_helper_status(struct libmnt_context *cxt)
+{
+	return cxt->helper_status;
+}
+
+/**
+ * mnt_context_syscall_called:
+ * @cxt: mount context
+ *
+ * Returns: 1 if mount(2) syscall has been called, or 0.
+ */
+int mnt_context_syscall_called(struct libmnt_context *cxt)
+{
+	return cxt->syscall_status != 1;
+}
+
+/**
+ * mnt_context_get_syscall_errno:
+ * @cxt: mount context
+ *
+ * The result from this function is reliable only if
+ * mnt_context_syscall_called() returns 1.
+ *
+ * Returns: mount(2) errno if the syscall failed or 0.
+ */
+int mnt_context_get_syscall_errno(struct libmnt_context *cxt)
+{
+	if (cxt->syscall_status < 0)
+		return -cxt->syscall_status;
+	return 0;
+}
+
+/**
+ * mnt_context_set_syscall_status:
+ * @cxt: mount context
+ * @status: mount(2) status
+ *
+ * The @status should be 0 on success, or negative number on error (-errno).
+ *
+ * This function should only be used if the [u]mount(2) syscall is NOT called by
+ * libmount code.
+ *
+ * Returns: 0 or negative number in case of error.
+ */
+int mnt_context_set_syscall_status(struct libmnt_context *cxt, int status)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "syscall status set to: %d", status));
+	cxt->syscall_status = status;
+	return 0;
+}
+
+/**
+ * mnt_context_strerror
+ * @cxt: context
+ * @buf: buffer
+ * @bufsiz: size of the buffer
+ *
+ * Not implemented, deprecated in favor or mnt_context_get_excode().
+ *
+ * Returns: 0 or negative number in case of error.
+ */
+int mnt_context_strerror(struct libmnt_context *cxt __attribute__((__unused__)),
+			 char *buf __attribute__((__unused__)),
+			 size_t bufsiz __attribute__((__unused__)))
+{
+	/* TODO: based on cxt->syscall_errno or cxt->helper_status */
+	return 0;
+}
+
+
+int mnt_context_get_generic_excode(int rc, char *buf, size_t bufsz, char *fmt, ...)
+{
+	va_list va;
+
+	if (rc == 0)
+		return MNT_EX_SUCCESS;
+
+	va_start(va, fmt);
+
+	/* we need to support "%m" */
+	errno = rc < 0 ? -rc : rc;
+
+	if (buf && bufsz && vsnprintf(buf, bufsz, fmt, va) < 0)
+		*buf = '\0';
+
+	switch (errno) {
+	case EINVAL:
+	case EPERM:
+		rc = MNT_EX_USAGE;
+		break;
+	case ENOMEM:
+		rc = MNT_EX_SYSERR;
+		break;
+	default:
+		rc = MNT_EX_FAIL;
+		break;
+	}
+	va_end(va);
+	return rc;
+}
+
+/**
+ * mnt_context_get_excode:
+ * @cxt: context
+ * @rc: return code of the previous operation
+ * @buf: buffer to print error message (optional)
+ * @bufsz: size of the buffer
+ *
+ * This function analyzes context, [u]mount syscall and external helper status
+ * and @mntrc and generates unified return code (see MNT_EX_*) as expected
+ * from mount(8) or umount(8).
+ *
+ * If the external helper (e.g. /sbin/mount.type) has been executed than it
+ * returns status from wait() of the helper. It's not libmount fail if helper
+ * returns some crazy undocumented codes...  See mnt_context_helper_executed()
+ * and mnt_context_get_helper_status(). Note that mount(8) and umount(8) utils
+ * always return code from helper without extra care about it.
+ *
+ * If the argument @buf is not NULL then error message is generated (if
+ * anything failed).
+ *
+ * The @mntrc is usually return code from mnt_context_mount(),
+ * mnt_context_umount(), or 'mntrc' as returned by mnt_context_next_mount().
+ *
+ * Since: 2.30
+ *
+ * Returns: MNT_EX_* codes.
+ */
+int mnt_context_get_excode(
+			struct libmnt_context *cxt,
+			int rc,
+			char *buf,
+			size_t bufsz)
+{
+	if (buf) {
+		*buf = '\0'; /* for sure */
+
+		if (!cxt->enabled_textdomain) {
+			bindtextdomain(LIBMOUNT_TEXTDOMAIN, LOCALEDIR);
+			cxt->enabled_textdomain = 1;
+		}
+	}
+
+	switch (cxt->action) {
+	case MNT_ACT_MOUNT:
+		rc = mnt_context_get_mount_excode(cxt, rc, buf, bufsz);
+		break;
+	case MNT_ACT_UMOUNT:
+		rc = mnt_context_get_umount_excode(cxt, rc, buf, bufsz);
+		break;
+	default:
+		if (rc)
+			rc = mnt_context_get_generic_excode(rc, buf, bufsz,
+				_("operation failed: %m"));
+		else
+			rc = MNT_EX_SUCCESS;
+		break;
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "excode: rc=%d message=\"%s\"", rc,
+				buf ? buf : "<no-message>"));
+	return rc;
+}
+
+
+/**
+ * mnt_context_init_helper
+ * @cxt: mount context
+ * @action: MNT_ACT_{UMOUNT,MOUNT}
+ * @flags: not used now
+ *
+ * This function informs libmount that used from [u]mount.type helper.
+ *
+ * The function also calls mnt_context_disable_helpers() to avoid recursive
+ * mount.type helpers calling. It you really want to call another
+ * mount.type helper from your helper, then you have to explicitly enable this
+ * feature by:
+ *
+ *	 mnt_context_disable_helpers(cxt, FALSE);
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_context_init_helper(struct libmnt_context *cxt, int action,
+			    int flags __attribute__((__unused__)))
+{
+	int rc;
+
+	if (!cxt)
+		return -EINVAL;
+
+	rc = mnt_context_disable_helpers(cxt, TRUE);
+	if (!rc)
+		rc = set_flag(cxt, MNT_FL_HELPER, 1);
+	if (!rc)
+		cxt->action = action;
+
+	DBG(CXT, ul_debugobj(cxt, "initialized for [u]mount.<type> helper [rc=%d]", rc));
+	return rc;
+}
+
+/**
+ * mnt_context_helper_setopt:
+ * @cxt: context
+ * @c: getopt() result
+ * @arg: getopt() optarg
+ *
+ * This function applies the [u]mount.type command line option (for example parsed
+ * by getopt or getopt_long) to @cxt. All unknown options are ignored and
+ * then 1 is returned.
+ *
+ * Returns: negative number on error, 1 if @c is unknown option, 0 on success.
+ */
+int mnt_context_helper_setopt(struct libmnt_context *cxt, int c, char *arg)
+{
+	if (cxt) {
+		switch(cxt->action) {
+		case MNT_ACT_MOUNT:
+			return mnt_context_mount_setopt(cxt, c, arg);
+		case MNT_ACT_UMOUNT:
+			return mnt_context_umount_setopt(cxt, c, arg);
+		}
+	}
+	return -EINVAL;
+}
+
+/**
+ * mnt_context_is_fs_mounted:
+ * @cxt: context
+ * @fs: filesystem
+ * @mounted: returns 1 for mounted and 0 for non-mounted filesystems
+ *
+ * Please, read the mnt_table_is_fs_mounted() description!
+ *
+ * Returns: 0 on success and negative number in case of error.
+ */
+int mnt_context_is_fs_mounted(struct libmnt_context *cxt,
+			      struct libmnt_fs *fs, int *mounted)
+{
+	struct libmnt_table *mtab, *orig;
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	if (!cxt || !fs || !mounted)
+		return -EINVAL;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	orig = cxt->mtab;
+	rc = mnt_context_get_mtab(cxt, &mtab);
+	if (rc == -ENOENT && mnt_fs_streq_target(fs, "/proc") &&
+	    (!cxt->mtab_path || startswith(cxt->mtab_path, "/proc/"))) {
+		if (!orig) {
+			mnt_unref_table(cxt->mtab);
+			cxt->mtab = NULL;
+		}
+		*mounted = 0;
+		return 0;	/* /proc not mounted */
+	}
+
+	if (rc)
+		return rc;
+
+	*mounted = __mnt_table_is_fs_mounted(mtab, fs,
+				mnt_context_get_target_prefix(cxt));
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return 0;
+}
+
+static int mnt_context_add_child(struct libmnt_context *cxt, pid_t pid)
+{
+	pid_t *pids;
+
+	if (!cxt)
+		return -EINVAL;
+
+	pids = realloc(cxt->children, sizeof(pid_t) * cxt->nchildren + 1);
+	if (!pids)
+		return -ENOMEM;
+
+	DBG(CXT, ul_debugobj(cxt, "add new child %d", pid));
+	cxt->children = pids;
+	cxt->children[cxt->nchildren++] = pid;
+
+	return 0;
+}
+
+int mnt_fork_context(struct libmnt_context *cxt)
+{
+	int rc = 0;
+	pid_t pid;
+
+	assert(cxt);
+	if (!mnt_context_is_parent(cxt))
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "forking context"));
+
+	DBG_FLUSH;
+
+	pid = fork();
+
+	switch (pid) {
+	case -1: /* error */
+		DBG(CXT, ul_debugobj(cxt, "fork failed %m"));
+		return -errno;
+
+	case 0: /* child */
+		cxt->pid = getpid();
+		mnt_context_enable_fork(cxt, FALSE);
+		DBG(CXT, ul_debugobj(cxt, "child created"));
+		break;
+
+	default:
+		rc = mnt_context_add_child(cxt, pid);
+		break;
+	}
+
+	return rc;
+}
+
+int mnt_context_wait_for_children(struct libmnt_context *cxt,
+				  int *nchildren, int *nerrs)
+{
+	int i;
+
+	if (!cxt)
+		return -EINVAL;
+
+	assert(mnt_context_is_parent(cxt));
+
+	for (i = 0; i < cxt->nchildren; i++) {
+		pid_t pid = cxt->children[i];
+		int rc = 0, ret = 0;
+
+		if (!pid)
+			continue;
+		do {
+			DBG(CXT, ul_debugobj(cxt,
+					"waiting for child (%d/%d): %d",
+					i + 1, cxt->nchildren, pid));
+			errno = 0;
+			rc = waitpid(pid, &ret, 0);
+
+		} while (rc == -1 && errno == EINTR);
+
+		if (nchildren)
+			(*nchildren)++;
+
+		if (rc != -1 && nerrs) {
+			if (WIFEXITED(ret))
+				(*nerrs) += WEXITSTATUS(ret) == 0 ? 0 : 1;
+			else
+				(*nerrs)++;
+		}
+		cxt->children[i] = 0;
+	}
+
+	cxt->nchildren = 0;
+	free(cxt->children);
+	cxt->children = NULL;
+	return 0;
+}
+
+static void close_ns(struct libmnt_ns *ns)
+{
+	if (ns->fd == -1)
+		return;
+
+	close(ns->fd);
+	ns->fd = -1;
+
+	mnt_unref_cache(ns->cache);
+	ns->cache = NULL;
+}
+
+/**
+ * mnt_context_set_target_ns:
+ * @cxt: mount context
+ * @path: path to target namespace or NULL
+ *
+ * Sets target namespace to namespace represented by @path. If @path is NULL,
+ * target namespace is cleared.
+ *
+ * This function sets errno to ENOSYS and returns error if libmount is
+ * compiled without namespaces support.
+*
+ * Returns: 0 on success, negative number in case of error.
+ *
+ * Since: 2.33
+ */
+int mnt_context_set_target_ns(struct libmnt_context *cxt, const char *path)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "Setting %s as target namespace", path));
+
+	/* cleanup only */
+	if (!path) {
+		close_ns(&cxt->ns_orig);
+		close_ns(&cxt->ns_tgt);
+		return 0;
+	}
+
+#ifdef USE_LIBMOUNT_SUPPORT_NAMESPACES
+	int errsv = 0;
+	int tmp;
+
+	errno = 0;
+
+	/* open original namespace */
+	if (cxt->ns_orig.fd == -1) {
+		cxt->ns_orig.fd = open("/proc/self/ns/mnt", O_RDONLY | O_CLOEXEC);
+		if (cxt->ns_orig.fd == -1)
+			return -errno;
+		cxt->ns_orig.cache = NULL;
+	}
+
+	/* open target (wanted) namespace */
+	tmp = open(path, O_RDONLY | O_CLOEXEC);
+	if (tmp == -1)
+		return -errno;
+
+	/* test whether namespace switching works */
+	DBG(CXT, ul_debugobj(cxt, "Trying whether namespace is valid"));
+	if (setns(tmp, CLONE_NEWNS)
+	    || setns(cxt->ns_orig.fd, CLONE_NEWNS)) {
+		errsv = errno;
+		DBG(CXT, ul_debugobj(cxt, "setns(2) failed [errno=%d %m]", errno));
+		goto err;
+	}
+
+	close_ns(&cxt->ns_tgt);
+
+	cxt->ns_tgt.fd = tmp;
+	cxt->ns_tgt.cache = NULL;
+
+	return 0;
+err:
+	close(tmp);
+	errno = errsv;
+
+#else /* ! USE_LIBMOUNT_SUPPORT_NAMESPACES */
+	errno = ENOSYS;
+#endif
+	return -errno;
+}
+
+/**
+ * mnt_context_get_target_ns:
+ * @cxt: mount context
+ *
+ * Returns: pointer to target namespace
+ *
+ * Since: 2.33
+ */
+struct libmnt_ns *mnt_context_get_target_ns(struct libmnt_context *cxt)
+{
+	return &cxt->ns_tgt;
+}
+
+/**
+ * mnt_context_get_origin_ns:
+ * @cxt: mount context
+ *
+ * Returns: pointer to original namespace
+ *
+ * Since: 2.33
+ */
+struct libmnt_ns *mnt_context_get_origin_ns(struct libmnt_context *cxt)
+{
+	return &cxt->ns_orig;
+}
+
+
+/**
+ * mnt_context_switch_ns:
+ * @cxt: mount context
+ * @ns: namespace to switch to
+ *
+ * Switch to namespace specified by ns
+ *
+ * Typical usage:
+ * <informalexample>
+ *   <programlisting>
+ *	struct libmnt_ns *ns_old;
+ *	ns_old = mnt_context_switch_ns(cxt, mnt_context_get_target_ns(cxt));
+ *	... code ...
+ *	mnt_context_switch_ns(cxt, ns_old);
+ *   </programlisting>
+ * </informalexample>
+ *
+ * Returns: pointer to previous namespace or NULL on error
+ *
+ * Since: 2.33
+ */
+struct libmnt_ns *mnt_context_switch_ns(struct libmnt_context *cxt, struct libmnt_ns *ns)
+{
+	struct libmnt_ns *old = NULL;
+
+	if (!cxt || !ns)
+		return NULL;
+
+	/*
+	 * If mnt_context_set_target_ns() has never been used than @ns file
+	 * descriptor is -1 and this function is noop.
+	 */
+	old = cxt->ns_cur;
+	if (ns == old || ns->fd == -1)
+		return old;
+
+#ifdef USE_LIBMOUNT_SUPPORT_NAMESPACES
+	/* remember the current cache */
+	if (old->cache != cxt->cache) {
+		mnt_unref_cache(old->cache);
+		old->cache = cxt->cache;
+		mnt_ref_cache(old->cache);
+	}
+
+	/* switch */
+	DBG(CXT, ul_debugobj(cxt, "Switching to %s namespace",
+		ns == mnt_context_get_target_ns(cxt) ? "target" :
+		ns == mnt_context_get_origin_ns(cxt) ? "original" : "other"));
+
+	if (setns(ns->fd, CLONE_NEWNS)) {
+		int errsv = errno;
+
+		DBG(CXT, ul_debugobj(cxt, "setns(2) failed [errno=%d %m]", errno));
+		errno = errsv;
+		return NULL;
+	}
+
+	/* update pointer to the current namespace */
+	cxt->ns_cur = ns;
+
+	/* update pointer to the cache */
+	mnt_unref_cache(cxt->cache);
+	cxt->cache = ns->cache;
+	mnt_ref_cache(cxt->cache);
+#endif /* USE_LIBMOUNT_SUPPORT_NAMESPACES */
+
+	return old;
+}
+
+/**
+ * mnt_context_switch_origin_ns:
+ * @cxt: mount context
+ *
+ * Switch to original namespace
+ *
+ * This is shorthand for
+ * <informalexample>
+ *   <programlisting>
+ *	mnt_context_switch_ns(cxt, mnt_context_get_origin_ns(cxt));
+ *   </programlisting>
+ * </informalexample>
+ *
+ * Returns: pointer to previous namespace or NULL on error
+ *
+ * Since: 2.33
+ */
+struct libmnt_ns *mnt_context_switch_origin_ns(struct libmnt_context *cxt)
+{
+	return mnt_context_switch_ns(cxt, mnt_context_get_origin_ns(cxt));
+}
+
+/**
+ * mnt_context_switch_target_ns:
+ * @cxt: mount context
+ *
+ * Switch to target namespace
+ *
+ * This is shorthand for
+ * <informalexample>
+ *   <programlisting>
+ *	mnt_context_switch_ns(cxt, mnt_context_get_target_ns(cxt));
+ *   </programlisting>
+ * </informalexample>
+ *
+ * Returns: pointer to previous namespace or NULL on error
+ *
+ * Since: 2.33
+ */
+struct libmnt_ns *mnt_context_switch_target_ns(struct libmnt_context *cxt)
+{
+	return mnt_context_switch_ns(cxt, mnt_context_get_target_ns(cxt));
+}
+
+
+#ifdef TEST_PROGRAM
+
+static int test_search_helper(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_context *cxt;
+	const char *type;
+	int rc;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	cxt = mnt_new_context();
+	if (!cxt)
+		return -ENOMEM;
+
+	type = argv[1];
+
+	mnt_context_get_fs(cxt);		/* just to fill cxt->fs */
+	cxt->flags |= MNT_FL_MOUNTFLAGS_MERGED;	/* fake */
+
+	rc = mnt_context_prepare_helper(cxt, "mount", type);
+	printf("helper is: %s\n", cxt->helper ? cxt->helper : "not found");
+
+	mnt_free_context(cxt);
+	return rc;
+}
+
+
+static struct libmnt_lock *lock;
+
+static void lock_fallback(void)
+{
+	if (lock)
+		mnt_unlock_file(lock);
+}
+
+static int test_mount(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int idx = 1, rc = 0;
+	struct libmnt_context *cxt;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	cxt = mnt_new_context();
+	if (!cxt)
+		return -ENOMEM;
+
+	if (!strcmp(argv[idx], "-o")) {
+		mnt_context_set_options(cxt, argv[idx + 1]);
+		idx += 2;
+	}
+	if (!strcmp(argv[idx], "-t")) {
+		/* TODO: use mnt_context_set_fstype_pattern() */
+		mnt_context_set_fstype(cxt, argv[idx + 1]);
+		idx += 2;
+	}
+
+	if (argc == idx + 1)
+		/* mount <mountpoint>|<device> */
+		mnt_context_set_target(cxt, argv[idx++]);
+
+	else if (argc == idx + 2) {
+		/* mount <device> <mountpoint> */
+		mnt_context_set_source(cxt, argv[idx++]);
+		mnt_context_set_target(cxt, argv[idx++]);
+	}
+
+	/* this is unnecessary! -- libmount is able to internally
+	 * create and manage the lock
+	 */
+	lock = mnt_context_get_lock(cxt);
+	if (lock)
+		atexit(lock_fallback);
+
+	rc = mnt_context_mount(cxt);
+	if (rc)
+		warn("failed to mount");
+	else
+		printf("successfully mounted\n");
+
+	lock = NULL;	/* because we use atexit lock_fallback */
+	mnt_free_context(cxt);
+	return rc;
+}
+
+static int test_umount(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int idx = 1, rc = 0;
+	struct libmnt_context *cxt;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	cxt = mnt_new_context();
+	if (!cxt)
+		return -ENOMEM;
+
+	if (!strcmp(argv[idx], "-t")) {
+		mnt_context_set_fstype(cxt, argv[idx + 1]);
+		idx += 2;
+	}
+
+	if (!strcmp(argv[idx], "-f")) {
+		mnt_context_enable_force(cxt, TRUE);
+		idx++;
+	}
+
+	if (!strcmp(argv[idx], "-l")) {
+		mnt_context_enable_lazy(cxt, TRUE);
+		idx++;
+	}
+
+	if (!strcmp(argv[idx], "-r")) {
+		mnt_context_enable_rdonly_umount(cxt, TRUE);
+		idx++;
+	}
+
+	if (argc == idx + 1) {
+		/* mount <mountpoint>|<device> */
+		mnt_context_set_target(cxt, argv[idx++]);
+	} else {
+		rc = -EINVAL;
+		goto err;
+	}
+
+	lock = mnt_context_get_lock(cxt);
+	if (lock)
+		atexit(lock_fallback);
+
+	rc = mnt_context_umount(cxt);
+	if (rc)
+		printf("failed to umount\n");
+	else
+		printf("successfully umounted\n");
+err:
+	lock = NULL;	/* because we use atexit lock_fallback */
+	mnt_free_context(cxt);
+	return rc;
+}
+
+static int test_flags(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int idx = 1, rc = 0;
+	struct libmnt_context *cxt;
+	const char *opt = NULL;
+	unsigned long flags = 0;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	cxt = mnt_new_context();
+	if (!cxt)
+		return -ENOMEM;
+
+	if (!strcmp(argv[idx], "-o")) {
+		mnt_context_set_options(cxt, argv[idx + 1]);
+		idx += 2;
+	}
+
+	if (argc == idx + 1)
+		/* mount <mountpoint>|<device> */
+		mnt_context_set_target(cxt, argv[idx++]);
+
+	rc = mnt_context_prepare_mount(cxt);
+	if (rc)
+		printf("failed to prepare mount %s\n", strerror(-rc));
+
+	opt = mnt_fs_get_options(cxt->fs);
+	if (opt)
+		fprintf(stdout, "options: %s\n", opt);
+
+	mnt_context_get_mflags(cxt, &flags);
+	fprintf(stdout, "flags: %08lx\n", flags);
+
+	mnt_free_context(cxt);
+	return rc;
+}
+
+static int test_mountall(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_context *cxt;
+	struct libmnt_iter *itr;
+	struct libmnt_fs *fs;
+	int mntrc, ignored, idx = 1;
+
+	cxt = mnt_new_context();
+	itr = mnt_new_iter(MNT_ITER_FORWARD);
+
+	if (!cxt || !itr)
+		return -ENOMEM;
+
+	if (argc > 2) {
+		if (argv[idx] && !strcmp(argv[idx], "-O")) {
+			mnt_context_set_options_pattern(cxt, argv[idx + 1]);
+			idx += 2;
+		}
+		if (argv[idx] && !strcmp(argv[idx], "-t")) {
+			mnt_context_set_fstype_pattern(cxt, argv[idx + 1]);
+			idx += 2;
+		}
+	}
+
+	while (mnt_context_next_mount(cxt, itr, &fs, &mntrc, &ignored) == 0) {
+
+		const char *tgt = mnt_fs_get_target(fs);
+
+		if (ignored == 1)
+			printf("%s: ignored: not match\n", tgt);
+		else if (ignored == 2)
+			printf("%s: ignored: already mounted\n", tgt);
+
+		else if (!mnt_context_get_status(cxt)) {
+			if (mntrc > 0) {
+				errno = mntrc;
+				warn("%s: mount failed", tgt);
+			} else
+				warnx("%s: mount failed", tgt);
+		} else
+			printf("%s: successfully mounted\n", tgt);
+	}
+
+	mnt_free_context(cxt);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+	{ "--mount",  test_mount,  "[-o <opts>] [-t <type>] <spec>|<src> <target>" },
+	{ "--umount", test_umount, "[-t <type>] [-f][-l][-r] <src>|<target>" },
+	{ "--mount-all", test_mountall,  "[-O <pattern>] [-t <pattern] mount all filesystems from fstab" },
+	{ "--flags", test_flags,   "[-o <opts>] <spec>" },
+	{ "--search-helper", test_search_helper, "<fstype>" },
+	{ NULL }};
+
+	umask(S_IWGRP|S_IWOTH);	/* to be compatible with mount(8) */
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/context_loopdev.c b/libmount/src/context_loopdev.c
new file mode 100644
index 0000000..c5fc80d
--- /dev/null
+++ b/libmount/src/context_loopdev.c
@@ -0,0 +1,446 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2011-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/*
+ * DOCS: - "lo@" prefix for fstype is unsupported
+ */
+
+#include <blkid.h>
+#include <stdbool.h>
+
+#include "mountP.h"
+#include "loopdev.h"
+#include "linux_version.h"
+
+
+int mnt_context_is_loopdev(struct libmnt_context *cxt)
+{
+	const char *type, *src;
+
+	assert(cxt);
+
+	/* The mount flags have to be merged, otherwise we have to use
+	 * expensive mnt_context_get_user_mflags() instead of cxt->user_mountflags. */
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!cxt->fs)
+		return 0;
+	src = mnt_fs_get_srcpath(cxt->fs);
+	if (!src)
+		return 0;		/* backing file not set */
+
+	if (cxt->user_mountflags & (MNT_MS_LOOP |
+				    MNT_MS_OFFSET |
+				    MNT_MS_SIZELIMIT)) {
+
+		DBG(LOOP, ul_debugobj(cxt, "loopdev specific options detected"));
+		return 1;
+	}
+
+	if ((cxt->mountflags & (MS_BIND | MS_MOVE))
+	    || mnt_context_propagation_only(cxt))
+		return 0;
+
+	/* Automatically create a loop device from a regular file if a
+	 * filesystem is not specified or the filesystem is known for libblkid
+	 * (these filesystems work with block devices only). The file size
+	 * should be at least 1KiB, otherwise we will create an empty loopdev with
+	 * no mountable filesystem...
+	 *
+	 * Note that there is no restriction (on kernel side) that would prevent a regular
+	 * file as a mount(2) source argument. A filesystem that is able to mount
+	 * regular files could be implemented.
+	 */
+	type = mnt_fs_get_fstype(cxt->fs);
+
+	if (mnt_fs_is_regular(cxt->fs) &&
+	    (!type || strcmp(type, "auto") == 0 || blkid_known_fstype(type))) {
+		struct stat st;
+
+		if (stat(src, &st) == 0 && S_ISREG(st.st_mode) &&
+		    st.st_size > 1024) {
+			DBG(LOOP, ul_debugobj(cxt, "automatically enabling loop= option"));
+			cxt->user_mountflags |= MNT_MS_LOOP;
+			mnt_optstr_append_option(&cxt->fs->user_optstr, "loop", NULL);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+
+/* Check if there already exists a mounted loop device on the mountpoint node
+ * with the same parameters.
+ */
+static int __attribute__((nonnull))
+is_mounted_same_loopfile(struct libmnt_context *cxt,
+				    const char *target,
+				    const char *backing_file,
+				    uint64_t offset)
+{
+	struct libmnt_table *tb;
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+	struct libmnt_cache *cache;
+	const char *bf;
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (mnt_context_get_mtab(cxt, &tb))
+		return 0;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	DBG(LOOP, ul_debugobj(cxt, "checking if %s mounted on %s",
+				backing_file, target));
+
+	cache = mnt_context_get_cache(cxt);
+	mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
+
+	bf = cache ? mnt_resolve_path(backing_file, cache) : backing_file;
+
+	/* Search for a mountpoint node in mtab, proceed if any of these have the
+	 * loop option set or the device is a loop device
+	 */
+	while (rc == 0 && mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		const char *src = mnt_fs_get_source(fs);
+		const char *opts = mnt_fs_get_user_options(fs);
+		char *val;
+		size_t len;
+
+		if (!src || !mnt_fs_match_target(fs, target, cache))
+			continue;
+
+		rc = 0;
+
+		if (strncmp(src, "/dev/loop", 9) == 0) {
+			rc = loopdev_is_used((char *) src, bf, offset, 0, LOOPDEV_FL_OFFSET);
+
+		} else if (opts && (cxt->user_mountflags & MNT_MS_LOOP) &&
+		    mnt_optstr_get_option(opts, "loop", &val, &len) == 0 && val) {
+
+			val = strndup(val, len);
+			rc = loopdev_is_used((char *) val, bf, offset, 0, LOOPDEV_FL_OFFSET);
+			free(val);
+		}
+	}
+	if (rc)
+		DBG(LOOP, ul_debugobj(cxt, "%s already mounted", backing_file));
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+int mnt_context_setup_loopdev(struct libmnt_context *cxt)
+{
+	const char *backing_file, *optstr, *loopdev = NULL;
+	char *val = NULL, *loopval = NULL;
+	size_t len;
+	struct loopdev_cxt lc;
+	int rc = 0, lo_flags = 0;
+	uint64_t offset = 0, sizelimit = 0;
+	bool reuse = FALSE;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	backing_file = mnt_fs_get_srcpath(cxt->fs);
+	if (!backing_file)
+		return -EINVAL;
+
+	DBG(LOOP, ul_debugobj(cxt, "trying to setup device for %s", backing_file));
+
+	if (cxt->mountflags & MS_RDONLY) {
+		DBG(LOOP, ul_debugobj(cxt, "enabling READ-ONLY flag"));
+		lo_flags |= LO_FLAGS_READ_ONLY;
+	}
+
+	optstr = mnt_fs_get_user_options(cxt->fs);
+
+	/*
+	 * loop=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_LOOP) &&
+	    mnt_optstr_get_option(optstr, "loop", &val, &len) == 0 && val) {
+		loopval = strndup(val, len);
+		rc = loopval ? 0 : -ENOMEM;
+	}
+
+	/*
+	 * offset=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_OFFSET) &&
+	    mnt_optstr_get_option(optstr, "offset", &val, &len) == 0) {
+		rc = mnt_parse_offset(val, len, &offset);
+		if (rc) {
+			DBG(LOOP, ul_debugobj(cxt, "failed to parse offset="));
+			rc = -MNT_ERR_MOUNTOPT;
+		}
+	}
+
+	/*
+	 * sizelimit=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_SIZELIMIT) &&
+	    mnt_optstr_get_option(optstr, "sizelimit", &val, &len) == 0) {
+		rc = mnt_parse_offset(val, len, &sizelimit);
+		if (rc) {
+			DBG(LOOP, ul_debugobj(cxt, "failed to parse sizelimit="));
+			rc = -MNT_ERR_MOUNTOPT;
+		}
+	}
+
+	/*
+	 * encryption=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_ENCRYPTION) &&
+	    mnt_optstr_get_option(optstr, "encryption", &val, &len) == 0) {
+		DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported"));
+		rc = -MNT_ERR_MOUNTOPT;
+	}
+
+	if (rc == 0 && is_mounted_same_loopfile(cxt,
+				mnt_context_get_target(cxt),
+				backing_file, offset))
+		rc = -EBUSY;
+
+	if (rc)
+		goto done_no_deinit;
+
+	/* It is possible to mount the same file more times. If we set more
+	 * than one loop device referring to the same file, kernel has no
+	 * mechanism to detect it. To prevent data corruption, the same loop
+	 * device has to be recycled.
+	*/
+	if (backing_file) {
+		rc = loopcxt_init(&lc, 0);
+		if (rc)
+			goto done_no_deinit;
+
+		rc = loopcxt_find_overlap(&lc, backing_file, offset, sizelimit);
+		switch (rc) {
+		case 0: /* not found */
+			DBG(LOOP, ul_debugobj(cxt, "not found overlapping loopdev"));
+			loopcxt_deinit(&lc);
+			break;
+
+		case 1:	/* overlap */
+			DBG(LOOP, ul_debugobj(cxt, "overlapping %s detected",
+						loopcxt_get_device(&lc)));
+			rc = -MNT_ERR_LOOPOVERLAP;
+			goto done;
+
+		case 2: /* overlap -- full size and offset match (reuse) */
+		{
+			uint32_t lc_encrypt_type;
+
+			DBG(LOOP, ul_debugobj(cxt, "re-using existing loop device %s",
+				loopcxt_get_device(&lc)));
+
+			/* Once a loop is initialized RO, there is no
+			 * way to change its parameters. */
+			if (loopcxt_is_readonly(&lc)
+			    && !(lo_flags & LO_FLAGS_READ_ONLY)) {
+				DBG(LOOP, ul_debugobj(cxt, "%s is read-only",
+						loopcxt_get_device(&lc)));
+				rc = -EROFS;
+				goto done;
+			}
+
+			/* This is no more supported, but check to be safe. */
+			if (loopcxt_get_encrypt_type(&lc, &lc_encrypt_type) == 0
+			    && lc_encrypt_type != LO_CRYPT_NONE) {
+				DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported for device %s",
+					loopcxt_get_device(&lc)));
+				rc = -MNT_ERR_LOOPOVERLAP;
+				goto done;
+			}
+			rc = 0;
+			/* loop= used with argument. Conflict will occur. */
+			if (loopval) {
+				rc = -MNT_ERR_LOOPOVERLAP;
+				goto done;
+			} else {
+				reuse = TRUE;
+				goto success;
+			}
+		}
+		default: /* error */
+			goto done;
+		}
+	}
+
+	DBG(LOOP, ul_debugobj(cxt, "not found; create a new loop device"));
+	rc = loopcxt_init(&lc, 0);
+	if (rc)
+		goto done_no_deinit;
+	if (loopval) {
+		rc = loopcxt_set_device(&lc, loopval);
+		if (rc == 0)
+			loopdev = loopcxt_get_device(&lc);
+	}
+	if (rc)
+		goto done;
+
+	/* since 2.6.37 we don't have to store backing filename to mtab
+	 * because kernel provides the name in /sys.
+	 */
+	if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
+	    !mnt_context_mtab_writable(cxt)) {
+		DBG(LOOP, ul_debugobj(cxt, "enabling AUTOCLEAR flag"));
+		lo_flags |= LO_FLAGS_AUTOCLEAR;
+	}
+
+	do {
+		/* found free device */
+		if (!loopdev) {
+			rc = loopcxt_find_unused(&lc);
+			if (rc)
+				goto done;
+			DBG(LOOP, ul_debugobj(cxt, "trying to use %s",
+						loopcxt_get_device(&lc)));
+		}
+
+		/* set device attributes
+		 * -- note that loopcxt_find_unused() resets "lc"
+		 */
+		rc = loopcxt_set_backing_file(&lc, backing_file);
+
+		if (!rc && offset)
+			rc = loopcxt_set_offset(&lc, offset);
+		if (!rc && sizelimit)
+			rc = loopcxt_set_sizelimit(&lc, sizelimit);
+		if (!rc)
+			loopcxt_set_flags(&lc, lo_flags);
+		if (rc) {
+			DBG(LOOP, ul_debugobj(cxt, "failed to set loop attributes"));
+			goto done;
+		}
+
+		/* setup the device */
+		rc = loopcxt_setup_device(&lc);
+		if (!rc)
+			break;		/* success */
+
+		if (loopdev || rc != -EBUSY) {
+			DBG(LOOP, ul_debugobj(cxt, "failed to setup device"));
+			rc = -MNT_ERR_LOOPDEV;
+			goto done;
+		}
+		DBG(LOOP, ul_debugobj(cxt, "device stolen...trying again"));
+	} while (1);
+
+success:
+	if (!rc)
+		rc = mnt_fs_set_source(cxt->fs, loopcxt_get_device(&lc));
+
+	if (!rc) {
+		/* success */
+		cxt->flags |= MNT_FL_LOOPDEV_READY;
+
+		if (reuse || ( (cxt->user_mountflags & MNT_MS_LOOP) &&
+		    loopcxt_is_autoclear(&lc))) {
+			/*
+			 * autoclear flag accepted by the kernel, don't store
+			 * the "loop=" option to mtab.
+			 */
+			DBG(LOOP, ul_debugobj(cxt, "removing unnecessary loop= from mtab"));
+			cxt->user_mountflags &= ~MNT_MS_LOOP;
+			mnt_optstr_remove_option(&cxt->fs->user_optstr, "loop");
+		}
+
+		if (!(cxt->mountflags & MS_RDONLY) &&
+		    loopcxt_is_readonly(&lc))
+			/*
+			 * mount planned read-write, but loopdev is read-only,
+			 * let's fix mount options...
+			 */
+			mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
+
+		/* we have to keep the device open until mount(1),
+		 * otherwise it will be auto-cleared by kernel
+		 */
+		cxt->loopdev_fd = loopcxt_get_fd(&lc);
+		if (cxt->loopdev_fd < 0) {
+			DBG(LOOP, ul_debugobj(cxt, "failed to get loopdev FD"));
+			rc = -errno;
+		} else
+			loopcxt_set_fd(&lc, -1, 0);
+	}
+done:
+	loopcxt_deinit(&lc);
+done_no_deinit:
+	free(loopval);
+	return rc;
+}
+
+/*
+ * Deletes loop device
+ */
+int mnt_context_delete_loopdev(struct libmnt_context *cxt)
+{
+	const char *src;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->fs);
+
+	src = mnt_fs_get_srcpath(cxt->fs);
+	if (!src)
+		return -EINVAL;
+
+	if (cxt->loopdev_fd > -1)
+		close(cxt->loopdev_fd);
+
+	rc = loopdev_delete(src);
+	cxt->flags &= ~MNT_FL_LOOPDEV_READY;
+	cxt->loopdev_fd = -1;
+
+	DBG(LOOP, ul_debugobj(cxt, "deleted [rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * Clears loopdev stuff in context, should be called after
+ * failed or successful mount(2).
+ */
+int mnt_context_clear_loopdev(struct libmnt_context *cxt)
+{
+	assert(cxt);
+
+	if (mnt_context_get_status(cxt) == 0 &&
+	    (cxt->flags & MNT_FL_LOOPDEV_READY)) {
+		/*
+		 * mount(2) failed, delete loopdev
+		 */
+		mnt_context_delete_loopdev(cxt);
+
+	} else if (cxt->loopdev_fd > -1) {
+		/*
+		 * mount(2) success, close the device
+		 */
+		DBG(LOOP, ul_debugobj(cxt, "closing FD"));
+		close(cxt->loopdev_fd);
+	}
+	cxt->loopdev_fd = -1;
+	return 0;
+}
+
diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c
new file mode 100644
index 0000000..8c394c1
--- /dev/null
+++ b/libmount/src/context_mount.c
@@ -0,0 +1,1935 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: context-mount
+ * @title: Mount context
+ * @short_description: high-level API to mount operation.
+ */
+
+#ifdef HAVE_LIBSELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#endif
+
+#include <sys/wait.h>
+#include <sys/mount.h>
+
+#include "linux_version.h"
+#include "mountP.h"
+#include "strutils.h"
+
+/*
+ * Kernel supports only one MS_PROPAGATION flag change by one mount(2) syscall,
+ * to bypass this restriction we call mount(2) per flag. It's really not a perfect
+ * solution, but it's the same like to execute multiple mount(8) commands.
+ *
+ * We use cxt->addmounts (additional mounts) list to keep order of the requested
+ * flags changes.
+ */
+struct libmnt_addmount *mnt_new_addmount(void)
+{
+	struct libmnt_addmount *ad = calloc(1, sizeof(*ad));
+	if (!ad)
+		return NULL;
+
+	INIT_LIST_HEAD(&ad->mounts);
+	return ad;
+}
+
+void mnt_free_addmount(struct libmnt_addmount *ad)
+{
+	if (!ad)
+		return;
+	list_del(&ad->mounts);
+	free(ad);
+}
+
+static int mnt_context_append_additional_mount(struct libmnt_context *cxt,
+					       struct libmnt_addmount *ad)
+{
+	assert(cxt);
+	assert(ad);
+
+	if (!list_empty(&ad->mounts))
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt,
+			"mount: add additional flag: 0x%08lx",
+			ad->mountflags));
+
+	list_add_tail(&ad->mounts, &cxt->addmounts);
+	return 0;
+}
+
+/*
+ * add additional mount(2) syscall requests when necessary to set propagation flags
+ * after regular mount(2).
+ */
+static int init_propagation(struct libmnt_context *cxt)
+{
+	char *name;
+	char *opts = (char *) mnt_fs_get_vfs_options(cxt->fs);
+	size_t namesz;
+	struct libmnt_optmap const *maps[1];
+	int rec_count = 0;
+
+	if (!opts)
+		return 0;
+
+	DBG(CXT, ul_debugobj(cxt, "mount: initialize additional propagation mounts"));
+
+	maps[0] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
+
+	while (!mnt_optstr_next_option(&opts, &name, &namesz, NULL, NULL)) {
+		const struct libmnt_optmap *ent;
+		struct libmnt_addmount *ad;
+		int rc;
+
+		if (!mnt_optmap_get_entry(maps, 1, name, namesz, &ent) || !ent)
+			continue;
+
+		DBG(CXT, ul_debugobj(cxt, " checking %s", ent->name));
+
+		/* Note that MS_REC may be used for more flags, so we have to keep
+		 * track about number of recursive options to keep the MS_REC in the
+		 * mountflags if necessary.
+		 */
+		if (ent->id & MS_REC)
+			rec_count++;
+
+		if (!(ent->id & MS_PROPAGATION))
+			continue;
+
+		ad = mnt_new_addmount();
+		if (!ad)
+			return -ENOMEM;
+
+		ad->mountflags = ent->id;
+		DBG(CXT, ul_debugobj(cxt, " adding extra mount(2) call for %s", ent->name));
+		rc = mnt_context_append_additional_mount(cxt, ad);
+		if (rc)
+			return rc;
+
+		DBG(CXT, ul_debugobj(cxt, " removing %s from primary mount(2) call", ent->name));
+		cxt->mountflags &= ~ent->id;
+
+		if (ent->id & MS_REC)
+			rec_count--;
+	}
+
+	if (rec_count)
+		cxt->mountflags |= MS_REC;
+
+	return 0;
+}
+
+/*
+ * add additional mount(2) syscall request to implement "bind,<flags>", the first regular
+ * mount(2) is the "bind" operation, the second is "remount,bind,<flags>" call.
+ */
+static int init_bind_remount(struct libmnt_context *cxt)
+{
+	struct libmnt_addmount *ad;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->mountflags & MS_BIND);
+	assert(!(cxt->mountflags & MS_REMOUNT));
+
+	DBG(CXT, ul_debugobj(cxt, "mount: initialize additional ro,bind mount"));
+
+	ad = mnt_new_addmount();
+	if (!ad)
+		return -ENOMEM;
+
+	ad->mountflags = cxt->mountflags;
+	ad->mountflags |= (MS_REMOUNT | MS_BIND);
+
+	rc = mnt_context_append_additional_mount(cxt, ad);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+#if defined(HAVE_LIBSELINUX) || defined(HAVE_SMACK)
+struct libmnt_optname {
+	const char *name;
+	size_t namesz;
+};
+
+#define DEF_OPTNAME(n)		{ .name = n, .namesz = sizeof(n) - 1 }
+#define DEF_OPTNAME_LAST	{ .name = NULL }
+
+static int is_option(const char *name, size_t namesz,
+		     const struct libmnt_optname *names)
+{
+	const struct libmnt_optname *p;
+
+	for (p = names; p && p->name; p++) {
+		if (p->namesz == namesz
+		    && strncmp(name, p->name, namesz) == 0)
+			return 1;
+	}
+
+	return 0;
+}
+#endif /* HAVE_LIBSELINUX || HAVE_SMACK */
+
+/*
+ * this has to be called after mnt_context_evaluate_permissions()
+ */
+static int fix_optstr(struct libmnt_context *cxt)
+{
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+	char *next;
+	char *name, *val;
+	size_t namesz, valsz;
+	struct libmnt_fs *fs;
+#ifdef HAVE_LIBSELINUX
+	int se_fix = 0, se_rem = 0;
+	static const struct libmnt_optname selinux_options[] = {
+		DEF_OPTNAME("context"),
+		DEF_OPTNAME("fscontext"),
+		DEF_OPTNAME("defcontext"),
+		DEF_OPTNAME("rootcontext"),
+		DEF_OPTNAME("seclabel"),
+		DEF_OPTNAME_LAST
+	};
+#endif
+#ifdef HAVE_SMACK
+	int sm_rem = 0;
+	static const struct libmnt_optname smack_options[] = {
+		DEF_OPTNAME("smackfsdef"),
+		DEF_OPTNAME("smackfsfloor"),
+		DEF_OPTNAME("smackfshat"),
+		DEF_OPTNAME("smackfsroot"),
+		DEF_OPTNAME("smackfstransmute"),
+		DEF_OPTNAME_LAST
+	};
+#endif
+	assert(cxt);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!cxt->fs || (cxt->flags & MNT_FL_MOUNTOPTS_FIXED))
+		return 0;
+
+	fs = cxt->fs;
+
+	DBG(CXT, ul_debugobj(cxt, "mount: fixing options, current "
+		"vfs: '%s' fs: '%s' user: '%s', optstr: '%s'",
+		fs->vfs_optstr, fs->fs_optstr, fs->user_optstr, fs->optstr));
+
+	/*
+	 * The "user" options is our business (so we can modify the option),
+	 * the exception is command line for /sbin/mount.<type> helpers. Let's
+	 * save the original user=<name> to call the helpers with an unchanged
+	 * "user" setting.
+	 */
+	if (cxt->user_mountflags & MNT_MS_USER) {
+		if (!mnt_optstr_get_option(fs->user_optstr,
+					"user", &val, &valsz) && val) {
+			cxt->orig_user = strndup(val, valsz);
+			if (!cxt->orig_user) {
+				rc = -ENOMEM;
+				goto done;
+			}
+		}
+		cxt->flags |= MNT_FL_SAVED_USER;
+	}
+
+	/*
+	 * Sync mount options with mount flags
+	 */
+	DBG(CXT, ul_debugobj(cxt, "mount: fixing vfs optstr"));
+	rc = mnt_optstr_apply_flags(&fs->vfs_optstr, cxt->mountflags,
+				mnt_get_builtin_optmap(MNT_LINUX_MAP));
+	if (rc)
+		goto done;
+
+	DBG(CXT, ul_debugobj(cxt, "mount: fixing user optstr"));
+	rc = mnt_optstr_apply_flags(&fs->user_optstr, cxt->user_mountflags,
+				mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
+	if (rc)
+		goto done;
+
+	if (fs->vfs_optstr && *fs->vfs_optstr == '\0') {
+		free(fs->vfs_optstr);
+		fs->vfs_optstr = NULL;
+	}
+	if (fs->user_optstr && *fs->user_optstr == '\0') {
+		free(fs->user_optstr);
+		fs->user_optstr = NULL;
+	}
+	if (cxt->mountflags & MS_PROPAGATION) {
+		rc = init_propagation(cxt);
+		if (rc)
+			return rc;
+	}
+	if ((cxt->mountflags & MS_BIND)
+	    && (cxt->mountflags & MNT_BIND_SETTABLE)
+	    && !(cxt->mountflags & MS_REMOUNT)) {
+		rc = init_bind_remount(cxt);
+		if (rc)
+			return rc;
+	}
+
+	next = fs->fs_optstr;
+
+#ifdef HAVE_LIBSELINUX
+	if (!is_selinux_enabled())
+		/* Always remove SELinux garbage if SELinux disabled */
+		se_rem = 1;
+	else if (cxt->mountflags & MS_REMOUNT)
+		/*
+		 * Linux kernel < 2.6.39 does not support remount operation
+		 * with any selinux specific mount options.
+		 *
+		 * Kernel 2.6.39 commits:  ff36fe2c845cab2102e4826c1ffa0a6ebf487c65
+		 *                         026eb167ae77244458fa4b4b9fc171209c079ba7
+		 * fix this odd behavior, so we don't have to care about it in
+		 * userspace.
+		 */
+		se_rem = get_linux_version() < KERNEL_VERSION(2, 6, 39);
+	else
+		/* For normal mount, contexts are translated */
+		se_fix = 1;
+
+	if (!se_rem) {
+		/* de-duplicate SELinux options */
+		const struct libmnt_optname *p;
+		for (p = selinux_options; p && p->name; p++)
+			mnt_optstr_deduplicate_option(&fs->fs_optstr, p->name);
+	}
+#endif
+#ifdef HAVE_SMACK
+	if (access("/sys/fs/smackfs", F_OK) != 0)
+		sm_rem = 1;
+#endif
+	while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
+
+		if (namesz == 3 && !strncmp(name, "uid", 3))
+			rc = mnt_optstr_fix_uid(&fs->fs_optstr, val, valsz, &next);
+		else if (namesz == 3 && !strncmp(name, "gid", 3))
+			rc = mnt_optstr_fix_gid(&fs->fs_optstr, val, valsz, &next);
+#ifdef HAVE_LIBSELINUX
+		else if ((se_rem || se_fix)
+			 && is_option(name, namesz, selinux_options)) {
+
+			if (se_rem) {
+				/* remove context= option */
+				next = name;
+				rc = mnt_optstr_remove_option_at(&fs->fs_optstr,
+						name,
+						val ? val + valsz :
+						      name + namesz);
+			} else if (se_fix && val && valsz)
+				/* translate selinux contexts */
+				rc = mnt_optstr_fix_secontext(&fs->fs_optstr,
+							val, valsz, &next);
+		}
+#endif
+#ifdef HAVE_SMACK
+		else if (sm_rem && is_option(name, namesz, smack_options)) {
+
+			next = name;
+			rc = mnt_optstr_remove_option_at(&fs->fs_optstr,
+					name,
+					val ? val + valsz : name + namesz);
+		}
+#endif
+		if (rc)
+			goto done;
+	}
+
+
+	if (!rc && mnt_context_is_restricted(cxt) && (cxt->user_mountflags & MNT_MS_USER)) {
+		ns_old = mnt_context_switch_origin_ns(cxt);
+		if (!ns_old)
+			return -MNT_ERR_NAMESPACE;
+
+		rc = mnt_optstr_fix_user(&fs->user_optstr);
+
+		if (!mnt_context_switch_ns(cxt, ns_old))
+			return -MNT_ERR_NAMESPACE;
+	}
+
+	/* refresh merged optstr */
+	free(fs->optstr);
+	fs->optstr = NULL;
+	fs->optstr = mnt_fs_strdup_options(fs);
+done:
+	cxt->flags |= MNT_FL_MOUNTOPTS_FIXED;
+
+	DBG(CXT, ul_debugobj(cxt, "fixed options [rc=%d]: "
+		"vfs: '%s' fs: '%s' user: '%s', optstr: '%s'", rc,
+		fs->vfs_optstr, fs->fs_optstr, fs->user_optstr, fs->optstr));
+
+	if (rc)
+		rc = -MNT_ERR_MOUNTOPT;
+	return rc;
+}
+
+/*
+ * Converts the already evaluated and fixed options to the form that is compatible
+ * with /sbin/mount.type helpers.
+ */
+static int generate_helper_optstr(struct libmnt_context *cxt, char **optstr)
+{
+	struct libmnt_optmap const *maps[2];
+	char *next, *name, *val;
+	size_t namesz, valsz;
+	int rc = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(optstr);
+
+	DBG(CXT, ul_debugobj(cxt, "mount: generate helper mount options"));
+
+	*optstr = mnt_fs_strdup_options(cxt->fs);
+	if (!*optstr)
+		return -ENOMEM;
+
+	if ((cxt->user_mountflags & MNT_MS_USER) ||
+	    (cxt->user_mountflags & MNT_MS_USERS)) {
+		/*
+		 * This is unnecessary for real user-mounts as mount.<type>
+		 * helpers always have to follow fstab rather than mount
+		 * options on the command line.
+		 *
+		 * However, if you call mount.<type> as root, then the helper follows
+		 * the command line. If there is (for example) "user,exec" in fstab,
+		 * then we have to manually append the "exec" back to the options
+		 * string, because there is nothing like MS_EXEC (we only have
+		 * MS_NOEXEC in mount flags and we don't care about the original
+		 * mount string in libmount for VFS options).
+		 */
+		if (!(cxt->mountflags & MS_NOEXEC))
+			mnt_optstr_append_option(optstr, "exec", NULL);
+		if (!(cxt->mountflags & MS_NOSUID))
+			mnt_optstr_append_option(optstr, "suid", NULL);
+		if (!(cxt->mountflags & MS_NODEV))
+			mnt_optstr_append_option(optstr, "dev", NULL);
+		if (!(cxt->mountflags & MS_NOSYMFOLLOW))
+			mnt_optstr_append_option(optstr, "symfollow", NULL);
+	}
+
+
+	if (cxt->flags & MNT_FL_SAVED_USER)
+		rc = mnt_optstr_set_option(optstr, "user", cxt->orig_user);
+	if (rc)
+		goto err;
+
+	/* remove userspace options with MNT_NOHLPS flag */
+	maps[0] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
+	maps[1] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
+	next = *optstr;
+
+	while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
+		const struct libmnt_optmap *ent;
+
+		mnt_optmap_get_entry(maps, 2, name, namesz, &ent);
+		if (ent && ent->id && (ent->mask & MNT_NOHLPS)) {
+			next = name;
+			rc = mnt_optstr_remove_option_at(optstr, name,
+					val ? val + valsz : name + namesz);
+			if (rc)
+				goto err;
+		}
+	}
+
+	return rc;
+err:
+	free(*optstr);
+	*optstr = NULL;
+	return rc;
+}
+
+/*
+ * this has to be called before fix_optstr()
+ *
+ * Note that user=<name> may be used by some filesystems as a filesystem
+ * specific option (e.g. cifs). Yes, developers of such filesystems have
+ * allocated pretty hot place in hell...
+ */
+static int evaluate_permissions(struct libmnt_context *cxt)
+{
+	unsigned long u_flags = 0;
+
+	assert(cxt);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!cxt->fs)
+		return 0;
+
+	DBG(CXT, ul_debugobj(cxt, "mount: evaluating permissions"));
+
+	mnt_context_get_user_mflags(cxt, &u_flags);
+
+	if (!mnt_context_is_restricted(cxt)) {
+		/*
+		 * superuser mount
+		 */
+		cxt->user_mountflags &= ~MNT_MS_OWNER;
+		cxt->user_mountflags &= ~MNT_MS_GROUP;
+	} else {
+		/*
+		 * user mount
+		 */
+		if (!mnt_context_tab_applied(cxt))
+		{
+			DBG(CXT, ul_debugobj(cxt, "perms: fstab not applied, ignore user mount"));
+			return -EPERM;
+		}
+
+		/*
+		 * MS_OWNERSECURE and MS_SECURE mount options are already
+		 * applied by mnt_optstr_get_flags() in mnt_context_merge_mflags()
+		 * if "user" (but no user=<name> !) options is set.
+		 *
+		 * Let's ignore all user=<name> (if <name> is set) requests.
+		 */
+		if (cxt->user_mountflags & MNT_MS_USER) {
+			size_t valsz = 0;
+
+			if (!mnt_optstr_get_option(cxt->fs->user_optstr,
+					"user", NULL, &valsz) && valsz) {
+
+				DBG(CXT, ul_debugobj(cxt, "perms: user=<name> detected, ignore"));
+				cxt->user_mountflags &= ~MNT_MS_USER;
+			}
+		}
+
+		/*
+		 * MS_OWNER: Allow owners to mount when fstab contains the
+		 * owner option.  Note that this should never be used in a high
+		 * security environment, but may be useful to give people at
+		 * the console the possibility of mounting a floppy.  MS_GROUP:
+		 * Allow members of device group to mount. (Martin Dickopp)
+		 */
+		if (u_flags & (MNT_MS_OWNER | MNT_MS_GROUP)) {
+			struct stat sb;
+			struct libmnt_cache *cache = NULL;
+			char *xsrc = NULL;
+			const char *srcpath = mnt_fs_get_srcpath(cxt->fs);
+
+			if (!srcpath) {					/* Ah... source is TAG */
+				cache = mnt_context_get_cache(cxt);
+				xsrc = mnt_resolve_spec(
+						mnt_context_get_source(cxt),
+						cache);
+				srcpath = xsrc;
+			}
+			if (!srcpath) {
+				DBG(CXT, ul_debugobj(cxt, "perms: src undefined"));
+				return -EPERM;
+			}
+
+			if (strncmp(srcpath, "/dev/", 5) == 0 &&
+			    stat(srcpath, &sb) == 0 &&
+			    (((u_flags & MNT_MS_OWNER) && getuid() == sb.st_uid) ||
+			     ((u_flags & MNT_MS_GROUP) && mnt_in_group(sb.st_gid))))
+
+				cxt->user_mountflags |= MNT_MS_USER;
+
+			if (!cache)
+				free(xsrc);
+		}
+
+		if (!(cxt->user_mountflags & (MNT_MS_USER | MNT_MS_USERS))) {
+			DBG(CXT, ul_debugobj(cxt, "permissions evaluation ends with -EPERMS"));
+			return -EPERM;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * mnt_context_helper_setopt() backend
+ *
+ * This function applies the mount.type command line option (for example parsed
+ * by getopt() or getopt_long()) to @cxt. All unknown options are ignored and
+ * then 1 is returned.
+ *
+ * Returns: negative number on error, 1 if @c is unknown option, 0 on success.
+ */
+int mnt_context_mount_setopt(struct libmnt_context *cxt, int c, char *arg)
+{
+	int rc = -EINVAL;
+
+	assert(cxt);
+	assert(cxt->action == MNT_ACT_MOUNT);
+
+	switch(c) {
+	case 'f':
+		rc = mnt_context_enable_fake(cxt, TRUE);
+		break;
+	case 'n':
+		rc = mnt_context_disable_mtab(cxt, TRUE);
+		break;
+	case 'r':
+		rc = mnt_context_append_options(cxt, "ro");
+		break;
+	case 'v':
+		rc = mnt_context_enable_verbose(cxt, TRUE);
+		break;
+	case 'w':
+		rc = mnt_context_append_options(cxt, "rw");
+		break;
+	case 'o':
+		if (arg)
+			rc = mnt_context_append_options(cxt, arg);
+		break;
+	case 's':
+		rc = mnt_context_enable_sloppy(cxt, TRUE);
+		break;
+	case 't':
+		if (arg)
+			rc = mnt_context_set_fstype(cxt, arg);
+		break;
+	case 'N':
+		if (arg)
+			rc = mnt_context_set_target_ns(cxt, arg);
+		break;
+	default:
+		return 1;
+	}
+
+	return rc;
+}
+
+static int exec_helper(struct libmnt_context *cxt)
+{
+	char *o = NULL, *namespace = NULL;
+	struct libmnt_ns *ns_tgt = mnt_context_get_target_ns(cxt);
+	int rc;
+	pid_t pid;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "mount: executing helper %s", cxt->helper));
+
+	rc = generate_helper_optstr(cxt, &o);
+	if (rc)
+		return -EINVAL;
+
+	if (ns_tgt->fd != -1
+	    && asprintf(&namespace, "/proc/%i/fd/%i",
+			getpid(), ns_tgt->fd) == -1) {
+		free(o);
+		return -ENOMEM;
+	}
+
+	DBG_FLUSH;
+
+	pid = fork();
+	switch (pid) {
+	case 0:
+	{
+		const char *args[14], *type;
+		int i = 0;
+
+		if (setgid(getgid()) < 0)
+			_exit(EXIT_FAILURE);
+
+		if (setuid(getuid()) < 0)
+			_exit(EXIT_FAILURE);
+
+		if (!mnt_context_switch_origin_ns(cxt))
+			_exit(EXIT_FAILURE);
+
+		type = mnt_fs_get_fstype(cxt->fs);
+
+		args[i++] = cxt->helper;		/* 1 */
+		args[i++] = mnt_fs_get_srcpath(cxt->fs);/* 2 */
+		args[i++] = mnt_fs_get_target(cxt->fs);	/* 3 */
+
+		if (mnt_context_is_sloppy(cxt))
+			args[i++] = "-s";		/* 4 */
+		if (mnt_context_is_fake(cxt))
+			args[i++] = "-f";		/* 5 */
+		if (mnt_context_is_nomtab(cxt))
+			args[i++] = "-n";		/* 6 */
+		if (mnt_context_is_verbose(cxt))
+			args[i++] = "-v";		/* 7 */
+		if (o) {
+			args[i++] = "-o";		/* 8 */
+			args[i++] = o;			/* 9 */
+		}
+		if (type
+		    && strchr(type, '.')
+		    && !endswith(cxt->helper, type)) {
+			args[i++] = "-t";		/* 10 */
+			args[i++] = type;		/* 11 */
+		}
+		if (namespace) {
+			args[i++] = "-N";		/* 11 */
+			args[i++] = namespace;		/* 12 */
+		}
+		args[i] = NULL;				/* 13 */
+		for (i = 0; args[i]; i++)
+			DBG(CXT, ul_debugobj(cxt, "argv[%d] = \"%s\"",
+							i, args[i]));
+		DBG_FLUSH;
+		execv(cxt->helper, (char * const *) args);
+		_exit(EXIT_FAILURE);
+	}
+	default:
+	{
+		int st;
+
+		if (waitpid(pid, &st, 0) == (pid_t) -1) {
+			cxt->helper_status = -1;
+			rc = -errno;
+		} else {
+			cxt->helper_status = WIFEXITED(st) ? WEXITSTATUS(st) : -1;
+			cxt->helper_exec_status = rc = 0;
+		}
+		DBG(CXT, ul_debugobj(cxt, "%s executed [status=%d, rc=%d%s]",
+				cxt->helper,
+				cxt->helper_status, rc,
+				rc ? " waitpid failed" : ""));
+		break;
+	}
+
+	case -1:
+		cxt->helper_exec_status = rc = -errno;
+		DBG(CXT, ul_debugobj(cxt, "fork() failed"));
+		break;
+	}
+
+	free(o);
+	return rc;
+}
+
+static int do_mount_additional(struct libmnt_context *cxt,
+			       const char *target,
+			       unsigned long flags,
+			       int *syserr)
+{
+	struct list_head *p;
+
+	assert(cxt);
+	assert(target);
+
+	if (syserr)
+		*syserr = 0;
+
+	list_for_each(p, &cxt->addmounts) {
+		int rc;
+		struct libmnt_addmount *ad =
+				list_entry(p, struct libmnt_addmount, mounts);
+
+		DBG(CXT, ul_debugobj(cxt, "mount(2) changing flag: 0x%08lx %s",
+				ad->mountflags,
+				ad->mountflags & MS_REC ? " (recursive)" : ""));
+
+		rc = mount("none", target, NULL,
+				ad->mountflags | (flags & MS_SILENT), NULL);
+		if (rc) {
+			if (syserr)
+				*syserr = -errno;
+			DBG(CXT, ul_debugobj(cxt,
+					"mount(2) failed [errno=%d %m]",
+					errno));
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * The default is to use fstype from cxt->fs, this could be overwritten by
+ * @try_type argument. If @try_type is specified then mount with MS_SILENT.
+ *
+ * Returns: 0 on success,
+ *         >0 in case of mount(2) error (returns syscall errno),
+ *         <0 in case of other errors.
+ */
+static int do_mount(struct libmnt_context *cxt, const char *try_type)
+{
+	int rc = 0;
+	const char *src, *target, *type;
+	unsigned long flags;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (try_type && !cxt->helper) {
+		rc = mnt_context_prepare_helper(cxt, "mount", try_type);
+		if (rc)
+			return rc;
+	}
+
+	flags = cxt->mountflags;
+	src = mnt_fs_get_srcpath(cxt->fs);
+	target = mnt_fs_get_target(cxt->fs);
+
+	if (cxt->helper) {
+		rc = exec_helper(cxt);
+
+		if (mnt_context_helper_executed(cxt)
+		    && mnt_context_get_helper_status(cxt) == 0
+		    && !list_empty(&cxt->addmounts)
+		    && do_mount_additional(cxt, target, flags, NULL))
+
+			return -MNT_ERR_APPLYFLAGS;
+		return rc;
+	}
+
+	if (!target)
+		return -EINVAL;
+	if (!src) {
+		/* unnecessary, should be already resolved in
+		 * mnt_context_prepare_srcpath(), but to be sure... */
+		DBG(CXT, ul_debugobj(cxt, "WARNING: source is NULL -- using \"none\"!"));
+		src = "none";
+	}
+	type = try_type ? : mnt_fs_get_fstype(cxt->fs);
+
+	if (try_type)
+		flags |= MS_SILENT;
+
+	DBG(CXT, ul_debugobj(cxt, "%smount(2) "
+			"[source=%s, target=%s, type=%s, "
+			" mountflags=0x%08lx, mountdata=%s]",
+			mnt_context_is_fake(cxt) ? "(FAKE) " : "",
+			src, target, type,
+			flags, cxt->mountdata ? "yes" : "<none>"));
+
+	if (mnt_context_is_fake(cxt)) {
+		/*
+		 * fake
+		 */
+		cxt->syscall_status = 0;
+
+	} else if (mnt_context_propagation_only(cxt)) {
+		/*
+		 * propagation flags *only*
+		 */
+		if (do_mount_additional(cxt, target, flags, &cxt->syscall_status))
+			return -MNT_ERR_APPLYFLAGS;
+	} else {
+		/*
+		 * regular mount
+		 */
+		if (mount(src, target, type, flags, cxt->mountdata)) {
+			cxt->syscall_status = -errno;
+			DBG(CXT, ul_debugobj(cxt, "mount(2) failed [errno=%d %m]",
+							-cxt->syscall_status));
+			return -cxt->syscall_status;
+		}
+		DBG(CXT, ul_debugobj(cxt, "  success"));
+		cxt->syscall_status = 0;
+
+		/*
+		 * additional mounts for extra propagation flags
+		 */
+		if (!list_empty(&cxt->addmounts)
+		    && do_mount_additional(cxt, target, flags, NULL)) {
+
+			/* TODO: call umount? */
+			return -MNT_ERR_APPLYFLAGS;
+		}
+	}
+
+	if (try_type && cxt->update) {
+		struct libmnt_fs *fs = mnt_update_get_fs(cxt->update);
+		if (fs)
+			rc = mnt_fs_set_fstype(fs, try_type);
+	}
+
+	return rc;
+}
+
+/* try mount(2) for all items in comma separated list of the filesystem @types */
+static int do_mount_by_types(struct libmnt_context *cxt, const char *types)
+{
+	int rc = -EINVAL;
+	char *p, *p0;
+
+	assert(cxt);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	DBG(CXT, ul_debugobj(cxt, "trying to mount by FS list '%s'", types));
+
+	p0 = p = strdup(types);
+	if (!p)
+		return -ENOMEM;
+	do {
+		char *autotype = NULL;
+		char *end = strchr(p, ',');
+
+		if (end)
+			*end = '\0';
+
+		DBG(CXT, ul_debugobj(cxt, "-->trying '%s'", p));
+
+		/* Let's support things like "udf,iso9660,auto" */
+		if (strcmp(p, "auto") == 0) {
+			rc = mnt_context_guess_srcpath_fstype(cxt, &autotype);
+			if (rc) {
+				DBG(CXT, ul_debugobj(cxt, "failed to guess FS type [rc=%d]", rc));
+				free(p0);
+				free(autotype);
+				return rc;
+			}
+			p = autotype;
+			DBG(CXT, ul_debugobj(cxt, "   --> '%s'", p));
+		}
+
+		if (p)
+			rc = do_mount(cxt, p);
+		p = end ? end + 1 : NULL;
+		free(autotype);
+	} while (!mnt_context_get_status(cxt) && p);
+
+	free(p0);
+	return rc;
+}
+
+
+static int do_mount_by_pattern(struct libmnt_context *cxt, const char *pattern)
+{
+	int neg = pattern && strncmp(pattern, "no", 2) == 0;
+	int rc = -EINVAL;
+	char **filesystems, **fp;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	/*
+	 * Use the pattern as list of the filesystems
+	 */
+	if (!neg && pattern) {
+		DBG(CXT, ul_debugobj(cxt, "use FS pattern as FS list"));
+		return do_mount_by_types(cxt, pattern);
+	}
+
+	DBG(CXT, ul_debugobj(cxt, "trying to mount by FS pattern '%s'", pattern));
+
+	/*
+	 * Apply pattern to /etc/filesystems and /proc/filesystems
+	 */
+	ns_old = mnt_context_switch_origin_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+	rc = mnt_get_filesystems(&filesystems, neg ? pattern : NULL);
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	if (rc)
+		return rc;
+
+	if (filesystems == NULL)
+		return -MNT_ERR_NOFSTYPE;
+
+	for (fp = filesystems; *fp; fp++) {
+		rc = do_mount(cxt, *fp);
+		if (mnt_context_get_status(cxt))
+			break;
+		if (mnt_context_get_syscall_errno(cxt) != EINVAL &&
+		    mnt_context_get_syscall_errno(cxt) != ENODEV)
+			break;
+	}
+	mnt_free_filesystems(filesystems);
+	return rc;
+}
+
+/**
+ * mnt_context_prepare_mount:
+ * @cxt: context
+ *
+ * Prepare context for mounting, unnecessary for mnt_context_mount().
+ *
+ * Returns: negative number on error, zero on success
+ */
+int mnt_context_prepare_mount(struct libmnt_context *cxt)
+{
+	int rc = -EINVAL;
+	struct libmnt_ns *ns_old;
+
+	if (!cxt || !cxt->fs || mnt_fs_is_swaparea(cxt->fs))
+		return -EINVAL;
+	if (!mnt_fs_get_source(cxt->fs) && !mnt_fs_get_target(cxt->fs))
+		return -EINVAL;
+	if (cxt->flags & MNT_FL_PREPARED)
+		return 0;
+
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+
+	cxt->action = MNT_ACT_MOUNT;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	DBG(CXT, ul_debugobj(cxt, "mount: preparing"));
+
+	rc = mnt_context_apply_fstab(cxt);
+	if (!rc)
+		rc = mnt_context_merge_mflags(cxt);
+	if (!rc)
+		rc = evaluate_permissions(cxt);
+	if (!rc)
+		rc = fix_optstr(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_srcpath(cxt);
+	if (!rc)
+		rc = mnt_context_guess_fstype(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_target(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_helper(cxt, "mount", NULL);
+	if (rc) {
+		DBG(CXT, ul_debugobj(cxt, "mount: preparing failed"));
+		goto end;
+	}
+	cxt->flags |= MNT_FL_PREPARED;
+
+end:
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/**
+ * mnt_context_do_mount
+ * @cxt: context
+ *
+ * Call mount(2) or mount.type helper. Unnecessary for mnt_context_mount().
+ *
+ * Note that this function could be called only once. If you want to mount
+ * another source or target, then you have to call mnt_reset_context().
+ *
+ * If you want to call mount(2) for the same source and target with different
+ * mount flags or fstype, then call mnt_context_reset_status() and then try
+ * again mnt_context_do_mount().
+ *
+ * WARNING: non-zero return code does not mean that mount(2) syscall or
+ *          mount.type helper wasn't successfully called.
+ *
+ * Check mnt_context_get_status() after error! See mnt_context_mount() for more
+ * details about errors and warnings.
+ *
+ * Returns: 0 on success;
+ *         >0 in case of mount(2) error (returns syscall errno),
+ *         <0 in case of other errors.
+ */
+int mnt_context_do_mount(struct libmnt_context *cxt)
+{
+	const char *type;
+	int res;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert((cxt->flags & MNT_FL_PREPARED));
+	assert((cxt->action == MNT_ACT_MOUNT));
+
+	DBG(CXT, ul_debugobj(cxt, "mount: do mount"));
+
+	if (!(cxt->flags & MNT_FL_MOUNTDATA))
+		cxt->mountdata = (char *) mnt_fs_get_fs_options(cxt->fs);
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	type = mnt_fs_get_fstype(cxt->fs);
+	if (type) {
+		if (strchr(type, ','))
+			/* this only happens if fstab contains a list of filesystems */
+			res = do_mount_by_types(cxt, type);
+		else
+			res = do_mount(cxt, NULL);
+	} else
+		res = do_mount_by_pattern(cxt, cxt->fstype_pattern);
+
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	if (mnt_context_get_status(cxt)
+	    && !mnt_context_is_fake(cxt)
+	    && !cxt->helper
+	    && mnt_context_mtab_writable(cxt)) {
+
+		int is_rdonly = -1;
+
+		DBG(CXT, ul_debugobj(cxt, "checking for RDONLY mismatch"));
+
+		/*
+		 * Mounted by mount(2), do some post-mount checks
+		 *
+		 * Kernel can be used to use MS_RDONLY for bind mounts, but the
+		 * read-only request could be silently ignored. Check it to
+		 * avoid 'ro' in mtab and 'rw' in /proc/mounts.
+		 */
+		if ((cxt->mountflags & MS_BIND)
+		    && (cxt->mountflags & MS_RDONLY)) {
+
+			if (is_rdonly < 0)
+				is_rdonly = mnt_is_readonly(mnt_context_get_target(cxt));
+			if (!is_rdonly)
+				mnt_context_set_mflags(cxt, cxt->mountflags & ~MS_RDONLY);
+		}
+
+
+		/* Kernel can silently add MS_RDONLY flag when mounting file
+		 * system that does not have write support. Check this to avoid
+		 * 'ro' in /proc/mounts and 'rw' in mtab.
+		 */
+		if (!(cxt->mountflags & (MS_RDONLY | MS_MOVE))
+		    && !mnt_context_propagation_only(cxt)) {
+
+			if (is_rdonly < 0)
+				is_rdonly = mnt_is_readonly(mnt_context_get_target(cxt));
+			if (is_rdonly)
+				mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
+		}
+	}
+#endif
+
+	/* Cleanup will be immediate on failure, and deferred to umount on success */
+	if (mnt_context_is_veritydev(cxt))
+		mnt_context_deferred_delete_veritydev(cxt);
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return res;
+}
+
+/*
+ * Returns mountinfo FS entry of context source patch if the source is already
+ * mounted. This function is used for "already mounted" message or to get FS of
+ * re-used loop device.
+ */
+static struct libmnt_fs *get_already_mounted_source(struct libmnt_context *cxt)
+{
+	const char *src;
+	struct libmnt_table *tb;
+
+	assert(cxt);
+
+	src = mnt_fs_get_srcpath(cxt->fs);
+
+	if (src && mnt_context_get_mtab(cxt, &tb) == 0) {
+		struct libmnt_iter itr;
+		struct libmnt_fs *fs;
+
+		mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+		while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+			const char *s = mnt_fs_get_srcpath(fs),
+				   *t = mnt_fs_get_target(fs);
+
+			if (t && s && mnt_fs_streq_srcpath(fs, src))
+				return fs;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Checks if source filesystem superblock is already ro-mounted. Note that we
+ * care about FS superblock as VFS node is irrelevant here.
+ */
+static int is_source_already_rdonly(struct libmnt_context *cxt)
+{
+	struct libmnt_fs *fs = get_already_mounted_source(cxt);
+	const char *opts = fs ? mnt_fs_get_fs_options(fs) : NULL;
+
+	return opts && mnt_optstr_get_option(opts, "ro", NULL, NULL) == 0;
+}
+
+/**
+ * mnt_context_finalize_mount:
+ * @cxt: context
+ *
+ * Mtab update, etc. Unnecessary for mnt_context_mount(), but should be called
+ * after mnt_context_do_mount(). See also mnt_context_set_syscall_status().
+ *
+ * Returns: negative number on error, 0 on success.
+ */
+int mnt_context_finalize_mount(struct libmnt_context *cxt)
+{
+	int rc;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert((cxt->flags & MNT_FL_PREPARED));
+
+	rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);
+	return rc;
+}
+
+/**
+ * mnt_context_mount:
+ * @cxt: mount context
+ *
+ * High-level, mounts the filesystem by mount(2) or fork()+exec(/sbin/mount.type).
+ *
+ * This is similar to:
+ *
+ *	mnt_context_prepare_mount(cxt);
+ *	mnt_context_do_mount(cxt);
+ *	mnt_context_finalize_mount(cxt);
+ *
+ * See also mnt_context_disable_helpers().
+ *
+ * Note that this function should be called only once. If you want to mount with
+ * different settings, then you have to call mnt_reset_context(). It's NOT enough
+ * to call mnt_context_reset_status(). If you want to call this function more than
+ * once, the whole context has to be reset.
+ *
+ * WARNING: non-zero return code does not mean that mount(2) syscall or
+ *          mount.type helper wasn't successfully called.
+ *
+ * Always use mnt_context_get_status():
+ *
+ * <informalexample>
+ *   <programlisting>
+ *       rc = mnt_context_mount(cxt);
+ *
+ *       if (mnt_context_helper_executed(cxt))
+ *               return mnt_context_get_helper_status(cxt);
+ *       if (rc == 0 && mnt_context_get_status(cxt) == 1)
+ *               return MNT_EX_SUCCESS;
+ *       return MNT_EX_FAIL;
+ *   </programlisting>
+ * </informalexample>
+ *
+ * or mnt_context_get_excode() to generate mount(8) compatible error
+ * or warning message:
+ *
+ * <informalexample>
+ *   <programlisting>
+ *       rc = mnt_context_mount(cxt);
+ *       rc = mnt_context_get_excode(cxt, rc, buf, sizeof(buf));
+ *       if (buf)
+ *               warnx(_("%s: %s"), mnt_context_get_target(cxt), buf);
+ *	 return rc;   // MNT_EX_*
+ *   </programlisting>
+ * </informalexample>
+ *
+ * Returns: 0 on success;
+ *         >0 in case of mount(2) error (returns syscall errno),
+ *         <0 in case of other errors.
+ */
+int mnt_context_mount(struct libmnt_context *cxt)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+again:
+	rc = mnt_context_prepare_mount(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_do_mount(cxt);
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);
+
+	/*
+	 * Read-only device or already read-only mounted FS.
+	 * Try mount the filesystem read-only.
+	 */
+	if ((rc == -EROFS && !mnt_context_syscall_called(cxt))	/* before syscall; rdonly loopdev */
+	     || mnt_context_get_syscall_errno(cxt) == EROFS	/* syscall failed with EROFS */
+	     || mnt_context_get_syscall_errno(cxt) == EACCES	/* syscall failed with EACCES */
+	     || (mnt_context_get_syscall_errno(cxt) == EBUSY	/* already ro-mounted FS */
+		 && is_source_already_rdonly(cxt)))
+	{
+		unsigned long mflags = 0;
+
+		mnt_context_get_mflags(cxt, &mflags);
+
+		if (!(mflags & MS_RDONLY)			/* not yet RDONLY */
+		    && !(mflags & MS_REMOUNT)			/* not remount */
+		    && !(mflags & MS_BIND)			/* not bin mount */
+		    && !mnt_context_is_rwonly_mount(cxt)) {	/* no explicit read-write */
+
+			assert(!(cxt->flags & MNT_FL_FORCED_RDONLY));
+			DBG(CXT, ul_debugobj(cxt, "write-protected source, trying RDONLY."));
+
+			mnt_context_reset_status(cxt);
+			mnt_context_set_mflags(cxt, mflags | MS_RDONLY);
+			cxt->flags |= MNT_FL_FORCED_RDONLY;
+			goto again;
+		}
+	}
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+/**
+ * mnt_context_next_mount:
+ * @cxt: context
+ * @itr: iterator
+ * @fs: returns the current filesystem
+ * @mntrc: returns the return code from mnt_context_mount()
+ * @ignored: returns 1 for non-matching and 2 for already mounted filesystems
+ *
+ * This function tries to mount the next filesystem from fstab (as returned by
+ * mnt_context_get_fstab()). See also mnt_context_set_fstab().
+ *
+ * You can filter out filesystems by:
+ *	mnt_context_set_options_pattern() to simulate mount -a -O pattern
+ *	mnt_context_set_fstype_pattern()  to simulate mount -a -t pattern
+ *
+ * If the filesystem is already mounted or does not match defined criteria,
+ * then the mnt_context_next_mount() function returns zero, but the @ignored is
+ * non-zero. Note that the root filesystem and filesystems with "noauto" option
+ * are always ignored.
+ *
+ * If mount(2) syscall or mount.type helper failed, then the
+ * mnt_context_next_mount() function returns zero, but the @mntrc is non-zero.
+ * Use also mnt_context_get_status() to check if the filesystem was
+ * successfully mounted.
+ *
+ * See mnt_context_mount() for more details about errors and warnings.
+ *
+ * Returns: 0 on success,
+ *         <0 in case of error (!= mount(2) errors)
+ *          1 at the end of the list.
+ */
+int mnt_context_next_mount(struct libmnt_context *cxt,
+			   struct libmnt_iter *itr,
+			   struct libmnt_fs **fs,
+			   int *mntrc,
+			   int *ignored)
+{
+	struct libmnt_table *fstab, *mtab;
+	const char *o, *tgt;
+	int rc, mounted = 0;
+
+	if (ignored)
+		*ignored = 0;
+	if (mntrc)
+		*mntrc = 0;
+
+	if (!cxt || !fs || !itr)
+		return -EINVAL;
+
+	rc = mnt_context_get_fstab(cxt, &fstab);
+	if (rc)
+		return rc;
+
+	rc = mnt_table_next_fs(fstab, itr, fs);
+	if (rc != 0)
+		return rc;	/* more filesystems (or error) */
+
+	o = mnt_fs_get_user_options(*fs);
+	tgt = mnt_fs_get_target(*fs);
+
+	DBG(CXT, ul_debugobj(cxt, "next-mount: trying %s", tgt));
+
+	/*  ignore swap */
+	if (mnt_fs_is_swaparea(*fs) ||
+
+	/* ignore root filesystem */
+	   (tgt && (strcmp(tgt, "/") == 0 || strcmp(tgt, "root") == 0)) ||
+
+	/* ignore noauto filesystems */
+	   (o && mnt_optstr_get_option(o, "noauto", NULL, NULL) == 0) ||
+
+	/* ignore filesystems which don't match options patterns */
+	   (cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
+					cxt->fstype_pattern)) ||
+
+	/* ignore filesystems which don't match type patterns */
+	   (cxt->optstr_pattern && !mnt_fs_match_options(*fs,
+					cxt->optstr_pattern))) {
+		if (ignored)
+			*ignored = 1;
+		DBG(CXT, ul_debugobj(cxt, "next-mount: not-match "
+				"[fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]",
+				mnt_fs_get_fstype(*fs),
+				cxt->fstype_pattern,
+				mnt_fs_get_options(*fs),
+				cxt->optstr_pattern));
+		return 0;
+	}
+
+	/* ignore already mounted filesystems */
+	rc = mnt_context_is_fs_mounted(cxt, *fs, &mounted);
+	if (rc)
+		return rc;
+	if (mounted) {
+		if (ignored)
+			*ignored = 2;
+		return 0;
+	}
+
+	/* Save mount options, etc. -- this is effective for the first
+	 * mnt_context_next_mount() call only. Make sure that cxt has not set
+	 * source, target or fstype.
+	 */
+	if (!mnt_context_has_template(cxt)) {
+		mnt_context_set_source(cxt, NULL);
+		mnt_context_set_target(cxt, NULL);
+		mnt_context_set_fstype(cxt, NULL);
+		mnt_context_save_template(cxt);
+	}
+
+	/* reset context, but protect mtab */
+	mtab = cxt->mtab;
+	cxt->mtab = NULL;
+	mnt_reset_context(cxt);
+	cxt->mtab = mtab;
+
+	if (mnt_context_is_fork(cxt)) {
+		rc = mnt_fork_context(cxt);
+		if (rc)
+			return rc;		/* fork error */
+
+		if (mnt_context_is_parent(cxt)) {
+			return 0;		/* parent */
+		}
+	}
+
+	/*
+	 * child or non-forked
+	 */
+
+	/* copy stuff from fstab to context */
+	rc = mnt_context_apply_fs(cxt, *fs);
+	if (!rc) {
+		/*
+		 * "-t <pattern>" is used to filter out fstab entries, but for ordinary
+		 * mount operation -t means "-t <type>". We have to zeroize the pattern
+		 * to avoid misinterpretation.
+		 */
+		char *pattern = cxt->fstype_pattern;
+		cxt->fstype_pattern = NULL;
+
+		rc = mnt_context_mount(cxt);
+
+		cxt->fstype_pattern = pattern;
+
+		if (mntrc)
+			*mntrc = rc;
+	}
+
+	if (mnt_context_is_child(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "next-mount: child exit [rc=%d]", rc));
+		DBG_FLUSH;
+		_exit(rc);
+	}
+	return 0;
+}
+
+
+/**
+ * mnt_context_next_remount:
+ * @cxt: context
+ * @itr: iterator
+ * @fs: returns the current filesystem
+ * @mntrc: returns the return code from mnt_context_mount()
+ * @ignored: returns 1 for non-matching
+ *
+ * This function tries to remount the next mounted filesystem (as returned by
+ * mnt_context_get_mtab()).
+ *
+ * You can filter out filesystems by:
+ *	mnt_context_set_options_pattern() to simulate mount -a -O pattern
+ *	mnt_context_set_fstype_pattern()  to simulate mount -a -t pattern
+ *
+ * If the filesystem does not match defined criteria, then the
+ * mnt_context_next_remount() function returns zero, but the @ignored is
+ * non-zero.
+ *
+ * IMPORTANT -- the mount operation is performed in the current context.
+ * The context is reset before the next mount (see mnt_reset_context()).
+ * The context setting related to the filesystem (e.g. mount options,
+ * etc.) are protected.
+
+ * If mount(2) syscall or mount.type helper failed, then the
+ * mnt_context_next_mount() function returns zero, but the @mntrc is non-zero.
+ * Use also mnt_context_get_status() to check if the filesystem was
+ * successfully mounted.
+ *
+ * See mnt_context_mount() for more details about errors and warnings.
+ *
+ * Returns: 0 on success,
+ *         <0 in case of error (!= mount(2) errors)
+ *          1 at the end of the list.
+ *
+ * Since: 2.34
+ */
+int mnt_context_next_remount(struct libmnt_context *cxt,
+			   struct libmnt_iter *itr,
+			   struct libmnt_fs **fs,
+			   int *mntrc,
+			   int *ignored)
+{
+	struct libmnt_table *mtab;
+	const char *tgt;
+	int rc;
+
+	if (ignored)
+		*ignored = 0;
+	if (mntrc)
+		*mntrc = 0;
+
+	if (!cxt || !fs || !itr)
+		return -EINVAL;
+
+	rc = mnt_context_get_mtab(cxt, &mtab);
+	if (rc)
+		return rc;
+
+	rc = mnt_table_next_fs(mtab, itr, fs);
+	if (rc != 0)
+		return rc;	/* more filesystems (or error) */
+
+	tgt = mnt_fs_get_target(*fs);
+
+	DBG(CXT, ul_debugobj(cxt, "next-remount: trying %s", tgt));
+
+	/* ignore filesystems which don't match options patterns */
+	if ((cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
+					cxt->fstype_pattern)) ||
+
+	/* ignore filesystems which don't match type patterns */
+	   (cxt->optstr_pattern && !mnt_fs_match_options(*fs,
+					cxt->optstr_pattern))) {
+		if (ignored)
+			*ignored = 1;
+		DBG(CXT, ul_debugobj(cxt, "next-remount: not-match "
+				"[fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]",
+				mnt_fs_get_fstype(*fs),
+				cxt->fstype_pattern,
+				mnt_fs_get_options(*fs),
+				cxt->optstr_pattern));
+		return 0;
+	}
+
+	/* Save mount options, etc. -- this is effective for the first
+	 * mnt_context_next_remount() call only. Make sure that cxt has not set
+	 * source, target or fstype.
+	 */
+	if (!mnt_context_has_template(cxt)) {
+		mnt_context_set_source(cxt, NULL);
+		mnt_context_set_target(cxt, NULL);
+		mnt_context_set_fstype(cxt, NULL);
+		mnt_context_save_template(cxt);
+	}
+
+	/* restore original, but protect mtab */
+	cxt->mtab = NULL;
+	mnt_reset_context(cxt);
+	cxt->mtab = mtab;
+
+	rc = mnt_context_set_target(cxt, tgt);
+	if (!rc) {
+		/*
+		 * "-t <pattern>" is used to filter out fstab entries, but for ordinary
+		 * mount operation -t means "-t <type>". We have to zeroize the pattern
+		 * to avoid misinterpretation.
+		 */
+		char *pattern = cxt->fstype_pattern;
+		cxt->fstype_pattern = NULL;
+
+		rc = mnt_context_mount(cxt);
+
+		cxt->fstype_pattern = pattern;
+
+		if (mntrc)
+			*mntrc = rc;
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/*
+ * Returns 1 if @dir parent is shared
+ */
+static int is_shared_tree(struct libmnt_context *cxt, const char *dir)
+{
+	struct libmnt_table *tb = NULL;
+	struct libmnt_fs *fs;
+	unsigned long mflags = 0;
+	char *mnt = NULL, *p;
+	int rc = 0;
+	struct libmnt_ns *ns_old;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	if (!dir)
+		return 0;
+	if (mnt_context_get_mtab(cxt, &tb) || !tb)
+		goto done;
+
+	mnt = strdup(dir);
+	if (!mnt)
+		goto done;
+	p = strrchr(mnt, '/');
+	if (!p)
+		goto done;
+	if (p > mnt)
+		*p = '\0';
+	fs = mnt_table_find_mountpoint(tb, mnt, MNT_ITER_BACKWARD);
+
+	rc = fs && mnt_fs_is_kernel(fs)
+		&& mnt_fs_get_propagation(fs, &mflags) == 0
+		&& (mflags & MS_SHARED);
+done:
+	free(mnt);
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+int mnt_context_get_mount_excode(
+			struct libmnt_context *cxt,
+			int rc,
+			char *buf,
+			size_t bufsz)
+{
+	int syserr;
+	struct stat st;
+	unsigned long uflags = 0, mflags = 0;
+
+	int restricted = mnt_context_is_restricted(cxt);
+	const char *tgt = mnt_context_get_target(cxt);
+	const char *src = mnt_context_get_source(cxt);
+
+	if (mnt_context_helper_executed(cxt)) {
+		/*
+		 * /sbin/mount.<type> called, return status
+		 */
+		if (rc == -MNT_ERR_APPLYFLAGS && buf)
+			snprintf(buf, bufsz, _("WARNING: failed to apply propagation flags"));
+
+		return mnt_context_get_helper_status(cxt);
+	}
+
+	if (rc == 0 && mnt_context_get_status(cxt) == 1) {
+		/*
+		 * Libmount success && syscall success.
+		 */
+		if (buf && mnt_context_forced_rdonly(cxt))
+			snprintf(buf, bufsz, _("WARNING: source write-protected, mounted read-only"));
+		return MNT_EX_SUCCESS;
+	}
+
+	mnt_context_get_mflags(cxt, &mflags);		/* mount(2) flags */
+	mnt_context_get_user_mflags(cxt, &uflags);	/* userspace flags */
+
+	if (!mnt_context_syscall_called(cxt)) {
+		/*
+		 * libmount errors (extra library checks)
+		 */
+		switch (rc) {
+		case -EPERM:
+			if (buf)
+				snprintf(buf, bufsz, _("operation permitted for root only"));
+			return MNT_EX_USAGE;
+		case -EBUSY:
+			if (buf)
+				snprintf(buf, bufsz, _("%s is already mounted"), src);
+			return MNT_EX_USAGE;
+		case -MNT_ERR_NOFSTAB:
+			if (!buf)
+				return MNT_EX_USAGE;
+			if (mnt_context_is_swapmatch(cxt))
+				snprintf(buf, bufsz, _("can't find in %s"),
+						mnt_get_fstab_path());
+			else if (tgt)
+				snprintf(buf, bufsz, _("can't find mount point in %s"),
+						mnt_get_fstab_path());
+			else if (src)
+				snprintf(buf, bufsz, _("can't find mount source %s in %s"),
+						src, mnt_get_fstab_path());
+			return MNT_EX_USAGE;
+		case -MNT_ERR_AMBIFS:
+			if (buf)
+				snprintf(buf, bufsz, _("more filesystems detected on %s; use -t <type> or wipefs(8)"), src);
+			return MNT_EX_USAGE;
+		case -MNT_ERR_NOFSTYPE:
+			if (buf)
+				snprintf(buf, bufsz, restricted ?
+						_("failed to determine filesystem type") :
+						_("no filesystem type specified"));
+			return MNT_EX_USAGE;
+		case -MNT_ERR_NOSOURCE:
+			if (uflags & MNT_MS_NOFAIL)
+				return MNT_EX_SUCCESS;
+			if (buf) {
+				if (src)
+					snprintf(buf, bufsz, _("can't find %s"), src);
+				else
+					snprintf(buf, bufsz, _("no mount source specified"));
+			}
+			return MNT_EX_USAGE;
+		case -MNT_ERR_MOUNTOPT:
+			if (buf)
+				snprintf(buf, bufsz, errno ?
+						_("failed to parse mount options: %m") :
+						_("failed to parse mount options"));
+			return MNT_EX_USAGE;
+		case -MNT_ERR_LOOPDEV:
+			if (buf)
+				snprintf(buf, bufsz, _("failed to setup loop device for %s"), src);
+			return MNT_EX_FAIL;
+		case -MNT_ERR_LOOPOVERLAP:
+			if (buf)
+				snprintf(buf, bufsz, _("overlapping loop device exists for %s"), src);
+			return MNT_EX_FAIL;
+		case -MNT_ERR_LOCK:
+			if (buf)
+				snprintf(buf, bufsz, _("locking failed"));
+			return MNT_EX_FILEIO;
+		case -MNT_ERR_NAMESPACE:
+			if (buf)
+				snprintf(buf, bufsz, _("failed to switch namespace"));
+			return MNT_EX_SYSERR;
+		default:
+			return mnt_context_get_generic_excode(rc, buf, bufsz, _("mount failed: %m"));
+		}
+
+	} else if (mnt_context_get_syscall_errno(cxt) == 0) {
+		/*
+		 * mount(2) syscall success, but something else failed
+		 * (probably error in mtab processing).
+		 */
+		if (rc == -MNT_ERR_LOCK) {
+			if (buf)
+				snprintf(buf, bufsz, _("filesystem was mounted, but failed to update userspace mount table"));
+			return MNT_EX_FILEIO;
+		}
+
+		if (rc == -MNT_ERR_NAMESPACE) {
+			if (buf)
+				snprintf(buf, bufsz, _("filesystem was mounted, but failed to switch namespace back"));
+			return MNT_EX_SYSERR;
+
+		}
+
+		if (rc < 0)
+			return mnt_context_get_generic_excode(rc, buf, bufsz,
+				_("filesystem was mounted, but any subsequent operation failed: %m"));
+
+		return MNT_EX_SOFTWARE;	/* internal error */
+
+	}
+
+	/*
+	 * mount(2) errors
+	 */
+	syserr = mnt_context_get_syscall_errno(cxt);
+
+
+	switch(syserr) {
+	case EPERM:
+		if (!buf)
+			break;
+		if (geteuid() == 0) {
+			if (mnt_stat_mountpoint(tgt, &st) || !S_ISDIR(st.st_mode))
+				snprintf(buf, bufsz, _("mount point is not a directory"));
+			else
+				snprintf(buf, bufsz, _("permission denied"));
+		} else
+			snprintf(buf, bufsz, _("must be superuser to use mount"));
+		break;
+
+	case EBUSY:
+		if (!buf)
+			break;
+		if (mflags & MS_REMOUNT) {
+			snprintf(buf, bufsz, _("mount point is busy"));
+			break;
+		}
+		if (src) {
+			struct libmnt_fs *fs = get_already_mounted_source(cxt);
+
+			if (fs && mnt_fs_get_target(fs))
+				snprintf(buf, bufsz, _("%s already mounted on %s"),
+						src, mnt_fs_get_target(fs));
+		}
+		if (!*buf)
+			snprintf(buf, bufsz, _("%s already mounted or mount point busy"), src);
+		break;
+	case ENOENT:
+		if (tgt && mnt_lstat_mountpoint(tgt, &st)) {
+			if (buf)
+				snprintf(buf, bufsz, _("mount point does not exist"));
+		} else if (tgt && mnt_stat_mountpoint(tgt, &st)) {
+			if (buf)
+				snprintf(buf, bufsz, _("mount point is a symbolic link to nowhere"));
+		} else if (src && stat(src, &st)) {
+			if (uflags & MNT_MS_NOFAIL)
+				return MNT_EX_SUCCESS;
+			if (buf)
+				snprintf(buf, bufsz, _("special device %s does not exist"), src);
+		} else if (buf) {
+			errno = syserr;
+			snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
+		}
+		break;
+
+	case ENOTDIR:
+		if (mnt_stat_mountpoint(tgt, &st) || ! S_ISDIR(st.st_mode)) {
+			if (buf)
+				snprintf(buf, bufsz, _("mount point is not a directory"));
+		} else if (src && stat(src, &st) && errno == ENOTDIR) {
+			if (uflags & MNT_MS_NOFAIL)
+				return MNT_EX_SUCCESS;
+			if (buf)
+				snprintf(buf, bufsz, _("special device %s does not exist "
+					 "(a path prefix is not a directory)"), src);
+		} else if (buf) {
+			errno = syserr;
+			snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
+		}
+		break;
+
+	case EINVAL:
+		if (!buf)
+			break;
+		if (mflags & MS_REMOUNT)
+			snprintf(buf, bufsz, _("mount point not mounted or bad option"));
+		else if (rc == -MNT_ERR_APPLYFLAGS)
+			snprintf(buf, bufsz, _("not mount point or bad option"));
+		else if ((mflags & MS_MOVE) && is_shared_tree(cxt, src))
+			snprintf(buf, bufsz,
+				_("bad option; moving a mount "
+				  "residing under a shared mount is unsupported"));
+		else if (mnt_fs_is_netfs(mnt_context_get_fs(cxt)))
+			snprintf(buf, bufsz,
+				_("bad option; for several filesystems (e.g. nfs, cifs) "
+				  "you might need a /sbin/mount.<type> helper program"));
+		else
+			snprintf(buf, bufsz,
+				_("wrong fs type, bad option, bad superblock on %s, "
+				  "missing codepage or helper program, or other error"),
+				src);
+		break;
+
+	case EMFILE:
+		if (buf)
+			snprintf(buf, bufsz, _("mount table full"));
+		break;
+
+	case EIO:
+		if (buf)
+			snprintf(buf, bufsz, _("can't read superblock on %s"), src);
+		break;
+
+	case ENODEV:
+		if (!buf)
+			break;
+		if (mnt_context_get_fstype(cxt))
+			snprintf(buf, bufsz, _("unknown filesystem type '%s'"),
+					mnt_context_get_fstype(cxt));
+		else
+			snprintf(buf, bufsz, _("unknown filesystem type"));
+		break;
+
+	case ENOTBLK:
+		if (uflags & MNT_MS_NOFAIL)
+			return MNT_EX_SUCCESS;
+		if (!buf)
+			break;
+		if (src && stat(src, &st))
+			snprintf(buf, bufsz, _("%s is not a block device, and stat(2) fails?"), src);
+		else if (src && S_ISBLK(st.st_mode))
+			snprintf(buf, bufsz,
+				_("the kernel does not recognize %s as a block device; "
+				  "maybe \"modprobe driver\" is necessary"), src);
+		else if (src && S_ISREG(st.st_mode))
+			snprintf(buf, bufsz, _("%s is not a block device; try \"-o loop\""), src);
+		else
+			snprintf(buf, bufsz, _("%s is not a block device"), src);
+		break;
+
+	case ENXIO:
+		if (uflags & MNT_MS_NOFAIL)
+			return MNT_EX_SUCCESS;
+		if (buf)
+			snprintf(buf, bufsz, _("%s is not a valid block device"), src);
+		break;
+
+	case EACCES:
+	case EROFS:
+		if (!buf)
+			break;
+		if (mflags & MS_RDONLY)
+			snprintf(buf, bufsz, _("cannot mount %s read-only"), src);
+		else if (mnt_context_is_rwonly_mount(cxt))
+			snprintf(buf, bufsz, _("%s is write-protected but explicit read-write mode requested"), src);
+		else if (mflags & MS_REMOUNT)
+			snprintf(buf, bufsz, _("cannot remount %s read-write, is write-protected"), src);
+		else if (mflags & MS_BIND)
+			snprintf(buf, bufsz, _("bind %s failed"), src);
+		else {
+			errno = syserr;
+			snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
+		}
+		break;
+
+	case ENOMEDIUM:
+		if (uflags & MNT_MS_NOFAIL)
+			return MNT_EX_SUCCESS;
+		if (buf)
+			snprintf(buf, bufsz, _("no medium found on %s"), src);
+		break;
+
+	case EBADMSG:
+		/* Bad CRC for classic filesystems (e.g. extN or XFS) */
+		if (buf && src && stat(src, &st) == 0
+		    && (S_ISBLK(st.st_mode) || S_ISREG(st.st_mode))) {
+			snprintf(buf, bufsz, _("cannot mount; probably corrupted filesystem on %s"), src);
+			break;
+		}
+		/* fallthrough */
+
+	default:
+		if (buf) {
+			errno = syserr;
+			snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
+		}
+		break;
+	}
+
+	return MNT_EX_FAIL;
+}
+
diff --git a/libmount/src/context_umount.c b/libmount/src/context_umount.c
new file mode 100644
index 0000000..df9a2eb
--- /dev/null
+++ b/libmount/src/context_umount.c
@@ -0,0 +1,1333 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: context-umount
+ * @title: Umount context
+ * @short_description: high-level API to umount operation.
+ */
+
+#include <sys/wait.h>
+#include <sys/mount.h>
+
+#include "pathnames.h"
+#include "loopdev.h"
+#include "strutils.h"
+#include "mountP.h"
+
+/*
+ * umount2 flags
+ */
+#ifndef MNT_FORCE
+# define MNT_FORCE        0x00000001	/* Attempt to forcibly umount */
+#endif
+
+#ifndef MNT_DETACH
+# define MNT_DETACH       0x00000002	/* Just detach from the tree */
+#endif
+
+#ifndef UMOUNT_NOFOLLOW
+# define UMOUNT_NOFOLLOW  0x00000008	/* Don't follow symlink on umount */
+#endif
+
+#ifndef UMOUNT_UNUSED
+# define UMOUNT_UNUSED    0x80000000	/* Flag guaranteed to be unused */
+#endif
+
+/* search in mountinfo/mtab */
+static int __mtab_find_umount_fs(struct libmnt_context *cxt,
+			    const char *tgt,
+			    struct libmnt_fs **pfs)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+	struct libmnt_table *mtab = NULL;
+	struct libmnt_fs *fs;
+	char *loopdev = NULL;
+
+	assert(cxt);
+	assert(tgt);
+	assert(pfs);
+
+	*pfs = NULL;
+	DBG(CXT, ul_debugobj(cxt, " search %s in mountinfo", tgt));
+
+	/*
+	 * The mount table may be huge, and on systems with utab we have to
+	 * merge userspace mount options into /proc/self/mountinfo. This all is
+	 * expensive. The tab filter can be used to filter out entries, then a mount
+	 * table and utab are very tiny files.
+	 *
+	 * The filter uses mnt_fs_streq_{target,srcpath} function where all
+	 * paths should be absolute and canonicalized. This is done within
+	 * mnt_context_get_mtab_for_target() where LABEL, UUID or symlinks are
+	 * canonicalized. If --no-canonicalize is enabled than the target path
+	 * is expected already canonical.
+	 *
+	 * Anyway it's better to read huge mount table than canonicalize target
+	 * paths. It means we use the filter only if --no-canonicalize enabled.
+	 *
+	 * It also means that we have to read mount table from kernel
+	 * (non-writable mtab).
+	 */
+	if (mnt_context_is_nocanonicalize(cxt) &&
+	    !mnt_context_mtab_writable(cxt) && *tgt == '/')
+		rc = mnt_context_get_mtab_for_target(cxt, &mtab, tgt);
+	else
+		rc = mnt_context_get_mtab(cxt, &mtab);
+
+	if (rc) {
+		DBG(CXT, ul_debugobj(cxt, "umount: failed to read mtab"));
+		return rc;
+	}
+
+	if (mnt_table_get_nents(mtab) == 0) {
+		DBG(CXT, ul_debugobj(cxt, "umount: mtab empty"));
+		return 1;
+	}
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+try_loopdev:
+	fs = mnt_table_find_target(mtab, tgt, MNT_ITER_BACKWARD);
+	if (!fs && mnt_context_is_swapmatch(cxt)) {
+		/*
+		 * Maybe the option is source rather than target (sometimes
+		 * people use e.g. "umount /dev/sda1")
+		 */
+		fs = mnt_table_find_source(mtab, tgt, MNT_ITER_BACKWARD);
+
+		if (fs) {
+			struct libmnt_fs *fs1 = mnt_table_find_target(mtab,
+							mnt_fs_get_target(fs),
+							MNT_ITER_BACKWARD);
+			if (!fs1) {
+				DBG(CXT, ul_debugobj(cxt, "mtab is broken?!?!"));
+				rc = -EINVAL;
+				goto err;
+			}
+			if (fs != fs1) {
+				/* Something was stacked over `file' on the
+				 * same mount point. */
+				DBG(CXT, ul_debugobj(cxt,
+						"umount: %s: %s is mounted "
+						"over it on the same point",
+						tgt, mnt_fs_get_source(fs1)));
+				rc = -EINVAL;
+				goto err;
+			}
+		}
+	}
+
+	if (!fs && !loopdev && mnt_context_is_swapmatch(cxt)) {
+		/*
+		 * Maybe the option is /path/file.img, try to convert to /dev/loopN
+		 */
+		struct stat st;
+
+		if (mnt_stat_mountpoint(tgt, &st) == 0 && S_ISREG(st.st_mode)) {
+			int count;
+			struct libmnt_cache *cache = mnt_context_get_cache(cxt);
+			const char *bf = cache ? mnt_resolve_path(tgt, cache) : tgt;
+
+			count = loopdev_count_by_backing_file(bf, &loopdev);
+			if (count == 1) {
+				DBG(CXT, ul_debugobj(cxt,
+					"umount: %s --> %s (retry)", tgt, loopdev));
+				tgt = loopdev;
+				goto try_loopdev;
+
+			} else if (count > 1)
+				DBG(CXT, ul_debugobj(cxt,
+					"umount: warning: %s is associated "
+					"with more than one loopdev", tgt));
+		}
+	}
+
+	*pfs = fs;
+	free(loopdev);
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	DBG(CXT, ul_debugobj(cxt, "umount fs: %s", fs ? mnt_fs_get_target(fs) :
+							"<not found>"));
+	return fs ? 0 : 1;
+err:
+	free(loopdev);
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+	return rc;
+}
+
+/**
+ * mnt_context_find_umount_fs:
+ * @cxt: mount context
+ * @tgt: mountpoint, device, ...
+ * @pfs: returns point to filesystem
+ *
+ * Returns: 0 on success, <0 on error, 1 if target filesystem not found
+ */
+int mnt_context_find_umount_fs(struct libmnt_context *cxt,
+			       const char *tgt,
+			       struct libmnt_fs **pfs)
+{
+	if (pfs)
+		*pfs = NULL;
+
+	if (!cxt || !tgt || !pfs)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "umount: lookup FS for '%s'", tgt));
+
+	if (!*tgt)
+		return 1; /* empty string is not an error */
+
+	/* In future this function should be extended to support for example
+	 * fsinfo() (or another cheap way kernel will support), for now the
+	 * default is expensive mountinfo/mtab.
+	 */
+	return __mtab_find_umount_fs(cxt, tgt, pfs);
+}
+
+/* Check if there is something important in the utab file. The parsed utab is
+ * stored in context->utab and deallocated by mnt_free_context().
+ *
+ * This function exists to avoid (if possible) /proc/self/mountinfo usage, so
+ * don't use things like mnt_resolve_target(), mnt_context_get_mtab() etc here.
+ * See lookup_umount_fs() for more details.
+ */
+static int has_utab_entry(struct libmnt_context *cxt, const char *target)
+{
+	struct libmnt_cache *cache = NULL;
+	struct libmnt_fs *fs;
+	struct libmnt_iter itr;
+	char *cn = NULL;
+	int rc = 0;
+
+	assert(cxt);
+
+	if (!cxt->utab) {
+		const char *path = mnt_get_utab_path();
+
+		if (!path || is_file_empty(path))
+			return 0;
+		cxt->utab = mnt_new_table();
+		if (!cxt->utab)
+			return 0;
+		cxt->utab->fmt = MNT_FMT_UTAB;
+		if (mnt_table_parse_file(cxt->utab, path))
+			return 0;
+	}
+
+	/* paths in utab are canonicalized */
+	cache = mnt_context_get_cache(cxt);
+	cn = mnt_resolve_path(target, cache);
+	mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
+
+	while (mnt_table_next_fs(cxt->utab, &itr, &fs) == 0) {
+		if (mnt_fs_streq_target(fs, cn)) {
+			rc = 1;
+			break;
+		}
+	}
+
+	if (!cache)
+		free(cn);
+	return rc;
+}
+
+/* returns: 1 not found; <0 on error; 1 success */
+static int lookup_umount_fs_by_statfs(struct libmnt_context *cxt, const char *tgt)
+{
+	struct stat st;
+	const char *type;
+
+	DBG(CXT, ul_debugobj(cxt, " lookup by statfs"));
+
+	/*
+	 * Let's try to avoid mountinfo usage at all to minimize performance
+	 * degradation. Don't forget that kernel has to compose *whole*
+	 * mountinfo about all mountpoints although we look for only one entry.
+	 *
+	 * All we need is fstype and to check if there is no userspace mount
+	 * options for the target (e.g. helper=udisks to call /sbin/umount.udisks).
+	 *
+	 * So, let's use statfs() if possible (it's bad idea for --lazy/--force
+	 * umounts as target is probably unreachable NFS, also for --detach-loop
+	 * as this additionally needs to know the name of the loop device).
+	 */
+	if (mnt_context_is_restricted(cxt)
+	    || *tgt != '/'
+	    || (cxt->flags & MNT_FL_HELPER)
+	    || mnt_context_mtab_writable(cxt)
+	    || mnt_context_is_force(cxt)
+	    || mnt_context_is_lazy(cxt)
+	    || mnt_context_is_nocanonicalize(cxt)
+	    || mnt_context_is_loopdel(cxt)
+	    || mnt_stat_mountpoint(tgt, &st) != 0 || !S_ISDIR(st.st_mode)
+	    || has_utab_entry(cxt, tgt))
+		return 1; /* not found */
+
+	type = mnt_fs_get_fstype(cxt->fs);
+
+	DBG(CXT, ul_debugobj(cxt, "  umount: disabling mtab"));
+	mnt_context_disable_mtab(cxt, TRUE);
+
+	if (!type) {
+		struct statfs vfs;
+		int fd;
+
+		DBG(CXT, ul_debugobj(cxt, "  trying fstatfs()"));
+
+		/* O_PATH avoids triggering automount points. */
+		fd = open(tgt, O_PATH);
+		if (fd >= 0) {
+			if (fstatfs(fd, &vfs) == 0)
+				type = mnt_statfs_get_fstype(&vfs);
+			close(fd);
+		}
+		if (type) {
+			int rc = mnt_fs_set_fstype(cxt->fs, type);
+			if (rc)
+				return rc;
+		}
+	}
+	if (type) {
+		DBG(CXT, ul_debugobj(cxt,
+			"  mountinfo unnecessary [type=%s]", type));
+		return 0;
+	}
+
+	return 1; /* not found */
+}
+
+/* returns: 1 not found; <0 on error; 1 success */
+static int lookup_umount_fs_by_mountinfo(struct libmnt_context *cxt, const char *tgt)
+{
+	struct libmnt_fs *fs = NULL;
+	int rc;
+
+	DBG(CXT, ul_debugobj(cxt, " lookup by mountinfo"));
+
+	/* search */
+	rc = __mtab_find_umount_fs(cxt, tgt, &fs);
+	if (rc != 0)
+		return rc;
+
+	/* apply result */
+	if (fs != cxt->fs) {
+		mnt_fs_set_source(cxt->fs, NULL);
+		mnt_fs_set_target(cxt->fs, NULL);
+
+		if (!mnt_copy_fs(cxt->fs, fs)) {
+			DBG(CXT, ul_debugobj(cxt, "  failed to copy FS"));
+			return -errno;
+		}
+		DBG(CXT, ul_debugobj(cxt, "  mtab applied"));
+	}
+
+	cxt->flags |= MNT_FL_TAB_APPLIED;
+	return 0;
+}
+
+/* This finction search for FS according to cxt->fs->target,
+ * apply result to cxt->fs and it's umount replacement to
+ * mnt_context_apply_fstab(), use mnt_context_tab_applied()
+ * to check result.
+ *
+ * The goal is to minimize situations when we need to parse
+ * /proc/self/mountinfo.
+ */
+static int lookup_umount_fs(struct libmnt_context *cxt)
+{
+	const char *tgt;
+	int rc = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+
+	DBG(CXT, ul_debugobj(cxt, "umount: lookup FS"));
+
+	tgt = mnt_fs_get_target(cxt->fs);
+	if (!tgt) {
+		DBG(CXT, ul_debugobj(cxt, " undefined target"));
+		return -EINVAL;
+	}
+
+	/* try get fs type by statfs() */
+	rc = lookup_umount_fs_by_statfs(cxt, tgt);
+	if (rc <= 0)
+		return rc;
+
+	/* get complete fs from fs entry from mountinfo */
+	rc = lookup_umount_fs_by_mountinfo(cxt, tgt);
+	if (rc <= 0)
+		return rc;
+
+	DBG(CXT, ul_debugobj(cxt, " cannot find '%s'", tgt));
+	return 0;	/* this is correct! */
+}
+
+/* check if @devname is loopdev and if the device is associated
+ * with a source from @fstab_fs
+ */
+static int is_associated_fs(const char *devname, struct libmnt_fs *fs)
+{
+	uintmax_t offset = 0;
+	const char *src, *optstr;
+	char *val;
+	size_t valsz;
+	int flags = 0;
+
+	/* check if it begins with /dev/loop */
+	if (strncmp(devname, _PATH_DEV_LOOP, sizeof(_PATH_DEV_LOOP) - 1) != 0)
+		return 0;
+
+	src = mnt_fs_get_srcpath(fs);
+	if (!src)
+		return 0;
+
+	/* check for the offset option in @fs */
+	optstr = mnt_fs_get_user_options(fs);
+
+	if (optstr &&
+	    mnt_optstr_get_option(optstr, "offset", &val, &valsz) == 0) {
+		flags |= LOOPDEV_FL_OFFSET;
+
+		if (mnt_parse_offset(val, valsz, &offset) != 0)
+			return 0;
+	}
+
+	return loopdev_is_used(devname, src, offset, 0, flags);
+}
+
+static int prepare_helper_from_options(struct libmnt_context *cxt,
+				       const char *name)
+{
+	char *suffix = NULL;
+	const char *opts;
+	size_t valsz;
+	int rc;
+
+	if (mnt_context_is_nohelpers(cxt))
+		return 0;
+
+	opts = mnt_fs_get_user_options(cxt->fs);
+	if (!opts)
+		return 0;
+
+	if (mnt_optstr_get_option(opts, name, &suffix, &valsz))
+		return 0;
+
+	suffix = strndup(suffix, valsz);
+	if (!suffix)
+		return -ENOMEM;
+
+	DBG(CXT, ul_debugobj(cxt, "umount: umount.%s %s requested", suffix, name));
+
+	rc = mnt_context_prepare_helper(cxt, "umount", suffix);
+	free(suffix);
+
+	return rc;
+}
+
+static int is_fuse_usermount(struct libmnt_context *cxt, int *errsv)
+{
+	struct libmnt_ns *ns_old;
+	const char *type = mnt_fs_get_fstype(cxt->fs);
+	const char *optstr;
+	char *user_id = NULL;
+	size_t sz;
+	uid_t uid;
+	char uidstr[sizeof(stringify_value(ULONG_MAX))];
+
+	*errsv = 0;
+
+	if (!type)
+		return 0;
+
+	if (strcmp(type, "fuse") != 0 &&
+	    strcmp(type, "fuseblk") != 0 &&
+	    strncmp(type, "fuse.", 5) != 0 &&
+	    strncmp(type, "fuseblk.", 8) != 0)
+		return 0;
+
+	/* get user_id= from mount table */
+	optstr = mnt_fs_get_fs_options(cxt->fs);
+	if (!optstr)
+		return 0;
+
+	if (mnt_optstr_get_option(optstr, "user_id", &user_id, &sz) != 0)
+		return 0;
+
+	if (sz == 0 || user_id == NULL)
+		return 0;
+
+	/* get current user */
+	ns_old = mnt_context_switch_origin_ns(cxt);
+	if (!ns_old) {
+		*errsv = -MNT_ERR_NAMESPACE;
+		return 0;
+	}
+
+	uid = getuid();
+
+	if (!mnt_context_switch_ns(cxt, ns_old)) {
+		*errsv = -MNT_ERR_NAMESPACE;
+		return 0;
+	}
+
+	snprintf(uidstr, sizeof(uidstr), "%lu", (unsigned long) uid);
+	return strncmp(user_id, uidstr, sz) == 0;
+}
+
+/*
+ * Note that cxt->fs contains relevant mtab entry!
+ */
+static int evaluate_permissions(struct libmnt_context *cxt)
+{
+	struct libmnt_table *fstab;
+	unsigned long u_flags = 0;
+	const char *tgt, *src, *optstr;
+	int rc = 0, ok = 0;
+	struct libmnt_fs *fs;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!mnt_context_is_restricted(cxt))
+		 return 0;		/* superuser mount */
+
+	DBG(CXT, ul_debugobj(cxt, "umount: evaluating permissions"));
+
+	if (!mnt_context_tab_applied(cxt)) {
+		DBG(CXT, ul_debugobj(cxt,
+				"cannot find %s in mtab and you are not root",
+				mnt_fs_get_target(cxt->fs)));
+		goto eperm;
+	}
+
+	if (cxt->user_mountflags & MNT_MS_UHELPER) {
+		/* on uhelper= mount option based helper */
+		rc = prepare_helper_from_options(cxt, "uhelper");
+		if (rc)
+			return rc;
+		if (cxt->helper)
+			return 0;	/* we'll call /sbin/umount.<uhelper> */
+	}
+
+	/*
+	 * Check if this is a fuse mount for the current user,
+	 * if so then unmounting is allowed
+	 */
+	if (is_fuse_usermount(cxt, &rc)) {
+		DBG(CXT, ul_debugobj(cxt, "fuse user mount, umount is allowed"));
+		return 0;
+	}
+	if (rc)
+		return rc;
+
+	/*
+	 * User mounts have to be in /etc/fstab
+	 */
+	rc = mnt_context_get_fstab(cxt, &fstab);
+	if (rc)
+		return rc;
+
+	tgt = mnt_fs_get_target(cxt->fs);
+	src = mnt_fs_get_source(cxt->fs);
+
+	if (mnt_fs_get_bindsrc(cxt->fs)) {
+		src = mnt_fs_get_bindsrc(cxt->fs);
+		DBG(CXT, ul_debugobj(cxt,
+				"umount: using bind source: %s", src));
+	}
+
+	/* If fstab contains the two lines
+	 *	/dev/sda1 /mnt/zip auto user,noauto  0 0
+	 *	/dev/sda4 /mnt/zip auto user,noauto  0 0
+	 * then "mount /dev/sda4" followed by "umount /mnt/zip" used to fail.
+	 * So, we must not look for the file, but for the pair (dev,file) in fstab.
+	  */
+	fs = mnt_table_find_pair(fstab, src, tgt, MNT_ITER_FORWARD);
+	if (!fs) {
+		/*
+		 * It's possible that there is /path/file.img in fstab and
+		 * /dev/loop0 in mtab -- then we have to check the relation
+		 * between loopdev and the file.
+		 */
+		fs = mnt_table_find_target(fstab, tgt, MNT_ITER_FORWARD);
+		if (fs) {
+			struct libmnt_cache *cache = mnt_context_get_cache(cxt);
+			const char *sp = mnt_fs_get_srcpath(cxt->fs);		/* devname from mtab */
+			const char *dev = sp && cache ? mnt_resolve_path(sp, cache) : sp;
+
+			if (!dev || !is_associated_fs(dev, fs))
+				fs = NULL;
+		}
+		if (!fs) {
+			DBG(CXT, ul_debugobj(cxt,
+					"umount %s: mtab disagrees with fstab",
+					tgt));
+			goto eperm;
+		}
+	}
+
+	/*
+	 * User mounting and unmounting is allowed only if fstab contains one
+	 * of the options `user', `users' or `owner' or `group'.
+	 *
+	 * The option `users' allows arbitrary users to mount and unmount -
+	 * this may be a security risk.
+	 *
+	 * The options `user', `owner' and `group' only allow unmounting by the
+	 * user that mounted (visible in mtab).
+	 */
+	optstr = mnt_fs_get_user_options(fs);	/* FSTAB mount options! */
+	if (!optstr)
+		goto eperm;
+
+	if (mnt_optstr_get_flags(optstr, &u_flags,
+				mnt_get_builtin_optmap(MNT_USERSPACE_MAP)))
+		goto eperm;
+
+	if (u_flags & MNT_MS_USERS) {
+		DBG(CXT, ul_debugobj(cxt,
+			"umount: promiscuous setting ('users') in fstab"));
+		return 0;
+	}
+	/*
+	 * Check user=<username> setting from mtab if there is a user, owner or
+	 * group option in /etc/fstab
+	 */
+	if (u_flags & (MNT_MS_USER | MNT_MS_OWNER | MNT_MS_GROUP)) {
+
+		char *curr_user;
+		char *mtab_user = NULL;
+		size_t sz;
+		struct libmnt_ns *ns_old;
+
+		DBG(CXT, ul_debugobj(cxt,
+				"umount: checking user=<username> from mtab"));
+
+		ns_old = mnt_context_switch_origin_ns(cxt);
+		if (!ns_old)
+			return -MNT_ERR_NAMESPACE;
+
+		curr_user = mnt_get_username(getuid());
+
+		if (!mnt_context_switch_ns(cxt, ns_old)) {
+			free(curr_user);
+			return -MNT_ERR_NAMESPACE;
+		}
+		if (!curr_user) {
+			DBG(CXT, ul_debugobj(cxt, "umount %s: cannot "
+				"convert %d to username", tgt, getuid()));
+			goto eperm;
+		}
+
+		/* get options from mtab */
+		optstr = mnt_fs_get_user_options(cxt->fs);
+		if (optstr && !mnt_optstr_get_option(optstr,
+					"user", &mtab_user, &sz) && sz)
+			ok = !strncmp(curr_user, mtab_user, sz);
+
+		free(curr_user);
+	}
+
+	if (ok) {
+		DBG(CXT, ul_debugobj(cxt, "umount %s is allowed", tgt));
+		return 0;
+	}
+eperm:
+	DBG(CXT, ul_debugobj(cxt, "umount is not allowed for you"));
+	return -EPERM;
+}
+
+static int exec_helper(struct libmnt_context *cxt)
+{
+	char *namespace = NULL;
+	struct libmnt_ns *ns_tgt = mnt_context_get_target_ns(cxt);
+	int rc;
+	pid_t pid;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert(cxt->helper_exec_status == 1);
+
+	if (mnt_context_is_fake(cxt)) {
+		DBG(CXT, ul_debugobj(cxt, "fake mode: does not execute helper"));
+		cxt->helper_exec_status = rc = 0;
+		return rc;
+	}
+
+	if (ns_tgt->fd != -1
+	    && asprintf(&namespace, "/proc/%i/fd/%i",
+			getpid(), ns_tgt->fd) == -1) {
+		return -ENOMEM;
+	}
+
+	DBG_FLUSH;
+
+	pid = fork();
+	switch (pid) {
+	case 0:
+	{
+		const char *args[12], *type;
+		int i = 0;
+
+		if (setgid(getgid()) < 0)
+			_exit(EXIT_FAILURE);
+
+		if (setuid(getuid()) < 0)
+			_exit(EXIT_FAILURE);
+
+		if (!mnt_context_switch_origin_ns(cxt))
+			_exit(EXIT_FAILURE);
+
+		type = mnt_fs_get_fstype(cxt->fs);
+
+		args[i++] = cxt->helper;			/* 1 */
+		args[i++] = mnt_fs_get_target(cxt->fs);		/* 2 */
+
+		if (mnt_context_is_nomtab(cxt))
+			args[i++] = "-n";			/* 3 */
+		if (mnt_context_is_lazy(cxt))
+			args[i++] = "-l";			/* 4 */
+		if (mnt_context_is_force(cxt))
+			args[i++] = "-f";			/* 5 */
+		if (mnt_context_is_verbose(cxt))
+			args[i++] = "-v";			/* 6 */
+		if (mnt_context_is_rdonly_umount(cxt))
+			args[i++] = "-r";			/* 7 */
+		if (type
+		    && strchr(type, '.')
+		    && !endswith(cxt->helper, type)) {
+			args[i++] = "-t";			/* 8 */
+			args[i++] = type;			/* 9 */
+		}
+		if (namespace) {
+			args[i++] = "-N";			/* 10 */
+			args[i++] = namespace;			/* 11 */
+		}
+
+		args[i] = NULL;					/* 12 */
+		for (i = 0; args[i]; i++)
+			DBG(CXT, ul_debugobj(cxt, "argv[%d] = \"%s\"",
+							i, args[i]));
+		DBG_FLUSH;
+		execv(cxt->helper, (char * const *) args);
+		_exit(EXIT_FAILURE);
+	}
+	default:
+	{
+		int st;
+
+		if (waitpid(pid, &st, 0) == (pid_t) -1) {
+			cxt->helper_status = -1;
+			rc = -errno;
+		} else {
+			cxt->helper_status = WIFEXITED(st) ? WEXITSTATUS(st) : -1;
+			cxt->helper_exec_status = rc = 0;
+		}
+		DBG(CXT, ul_debugobj(cxt, "%s executed [status=%d, rc=%d%s]",
+				cxt->helper,
+				cxt->helper_status, rc,
+				rc ? " waitpid failed" : ""));
+		break;
+	}
+
+	case -1:
+		cxt->helper_exec_status = rc = -errno;
+		DBG(CXT, ul_debugobj(cxt, "fork() failed"));
+		break;
+	}
+
+	return rc;
+}
+
+/*
+ * mnt_context_helper_setopt() backend.
+ *
+ * This function applies umount.type command line option (for example parsed
+ * by getopt() or getopt_long()) to @cxt. All unknown options are ignored and
+ * then 1 is returned.
+ *
+ * Returns: negative number on error, 1 if @c is unknown option, 0 on success.
+ */
+int mnt_context_umount_setopt(struct libmnt_context *cxt, int c, char *arg)
+{
+	int rc = -EINVAL;
+
+	assert(cxt);
+	assert(cxt->action == MNT_ACT_UMOUNT);
+
+	switch(c) {
+	case 'n':
+		rc = mnt_context_disable_mtab(cxt, TRUE);
+		break;
+	case 'l':
+		rc = mnt_context_enable_lazy(cxt, TRUE);
+		break;
+	case 'f':
+		rc = mnt_context_enable_force(cxt, TRUE);
+		break;
+	case 'v':
+		rc = mnt_context_enable_verbose(cxt, TRUE);
+		break;
+	case 'r':
+		rc = mnt_context_enable_rdonly_umount(cxt, TRUE);
+		break;
+	case 't':
+		if (arg)
+			rc = mnt_context_set_fstype(cxt, arg);
+		break;
+	case 'N':
+		if (arg)
+			rc = mnt_context_set_target_ns(cxt, arg);
+		break;
+	default:
+		return 1;
+	}
+
+	return rc;
+}
+
+/* Check whether the kernel supports the UMOUNT_NOFOLLOW flag */
+static int umount_nofollow_support(void)
+{
+	int res = umount2("", UMOUNT_UNUSED);
+	if (res != -1 || errno != EINVAL)
+		return 0;
+
+	res = umount2("", UMOUNT_NOFOLLOW);
+	if (res != -1 || errno != ENOENT)
+		return 0;
+
+	return 1;
+}
+
+static int do_umount(struct libmnt_context *cxt)
+{
+	int rc = 0, flags = 0;
+	const char *src, *target;
+	char *tgtbuf = NULL;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert(cxt->syscall_status == 1);
+
+	if (cxt->helper)
+		return exec_helper(cxt);
+
+	src = mnt_fs_get_srcpath(cxt->fs);
+	target = mnt_fs_get_target(cxt->fs);
+
+	if (!target)
+		return -EINVAL;
+
+	DBG(CXT, ul_debugobj(cxt, "do umount"));
+
+	if (mnt_context_is_restricted(cxt) && !mnt_context_is_fake(cxt)) {
+		/*
+		 * extra paranoia for non-root users
+		 * -- chdir to the parent of the mountpoint and use NOFOLLOW
+		 *    flag to avoid races and symlink attacks.
+		 */
+		if (umount_nofollow_support())
+			flags |= UMOUNT_NOFOLLOW;
+
+		rc = mnt_chdir_to_parent(target, &tgtbuf);
+		if (rc)
+			return rc;
+		target = tgtbuf;
+	}
+
+	if (mnt_context_is_lazy(cxt))
+		flags |= MNT_DETACH;
+
+	if (mnt_context_is_force(cxt))
+		flags |= MNT_FORCE;
+
+	DBG(CXT, ul_debugobj(cxt, "umount(2) [target='%s', flags=0x%08x]%s",
+				target, flags,
+				mnt_context_is_fake(cxt) ? " (FAKE)" : ""));
+
+	if (mnt_context_is_fake(cxt))
+		rc = 0;
+	else {
+		rc = flags ? umount2(target, flags) : umount(target);
+		if (rc < 0)
+			cxt->syscall_status = -errno;
+		free(tgtbuf);
+	}
+
+	/*
+	 * try remount read-only
+	 */
+	if (rc < 0
+	    && cxt->syscall_status == -EBUSY
+	    && mnt_context_is_rdonly_umount(cxt)
+	    && src) {
+
+		mnt_context_set_mflags(cxt, (cxt->mountflags |
+					     MS_REMOUNT | MS_RDONLY));
+		mnt_context_enable_loopdel(cxt, FALSE);
+
+		DBG(CXT, ul_debugobj(cxt,
+			"umount(2) failed [errno=%d] -- trying to remount read-only",
+			-cxt->syscall_status));
+
+		rc = mount(src, mnt_fs_get_target(cxt->fs), NULL,
+			    MS_REMOUNT | MS_RDONLY, NULL);
+		if (rc < 0) {
+			cxt->syscall_status = -errno;
+			DBG(CXT, ul_debugobj(cxt,
+				"read-only re-mount(2) failed [errno=%d]",
+				-cxt->syscall_status));
+
+			return -cxt->syscall_status;
+		}
+		cxt->syscall_status = 0;
+		DBG(CXT, ul_debugobj(cxt, "read-only re-mount(2) success"));
+		return 0;
+	}
+
+	if (rc < 0) {
+		DBG(CXT, ul_debugobj(cxt, "umount(2) failed [errno=%d]",
+			-cxt->syscall_status));
+		return -cxt->syscall_status;
+	}
+
+	cxt->syscall_status = 0;
+	DBG(CXT, ul_debugobj(cxt, "umount(2) success"));
+	return 0;
+}
+
+/**
+ * mnt_context_prepare_umount:
+ * @cxt: mount context
+ *
+ * Prepare context for umounting, unnecessary for mnt_context_umount().
+ *
+ * Returns: 0 on success, and negative number in case of error.
+ */
+int mnt_context_prepare_umount(struct libmnt_context *cxt)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	if (!cxt || !cxt->fs || mnt_fs_is_swaparea(cxt->fs))
+		return -EINVAL;
+	if (!mnt_context_get_source(cxt) && !mnt_context_get_target(cxt))
+		return -EINVAL;
+	if (cxt->flags & MNT_FL_PREPARED)
+		return 0;
+
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+
+	free(cxt->helper);	/* be paranoid */
+	cxt->helper = NULL;
+	cxt->action = MNT_ACT_UMOUNT;
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	rc = lookup_umount_fs(cxt);
+	if (!rc)
+		rc = mnt_context_merge_mflags(cxt);
+	if (!rc)
+		rc = evaluate_permissions(cxt);
+
+	if (!rc && !cxt->helper) {
+
+		if (cxt->user_mountflags & MNT_MS_HELPER)
+			/* on helper= mount option based helper */
+			rc = prepare_helper_from_options(cxt, "helper");
+
+		if (!rc && !cxt->helper)
+			/* on fstype based helper */
+			rc = mnt_context_prepare_helper(cxt, "umount", NULL);
+	}
+
+	if (!rc && (cxt->user_mountflags & MNT_MS_LOOP))
+		/* loop option explicitly specified in mtab, detach this loop */
+		mnt_context_enable_loopdel(cxt, TRUE);
+
+	if (!rc && mnt_context_is_loopdel(cxt) && cxt->fs) {
+		const char *src = mnt_fs_get_srcpath(cxt->fs);
+
+		if (src && (!is_loopdev(src) || loopdev_is_autoclear(src)))
+			mnt_context_enable_loopdel(cxt, FALSE);
+	}
+
+	if (rc) {
+		DBG(CXT, ul_debugobj(cxt, "umount: preparing failed"));
+		return rc;
+	}
+	cxt->flags |= MNT_FL_PREPARED;
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/**
+ * mnt_context_do_umount:
+ * @cxt: mount context
+ *
+ * Umount filesystem by umount(2) or fork()+exec(/sbin/umount.type).
+ * Unnecessary for mnt_context_umount().
+ *
+ * See also mnt_context_disable_helpers().
+ *
+ * WARNING: non-zero return code does not mean that umount(2) syscall or
+ *          umount.type helper wasn't successfully called.
+ *
+ *          Check mnt_context_get_status() after error!
+*
+ * Returns: 0 on success;
+ *         >0 in case of umount(2) error (returns syscall errno),
+ *         <0 in case of other errors.
+ */
+int mnt_context_do_umount(struct libmnt_context *cxt)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+	assert((cxt->flags & MNT_FL_PREPARED));
+	assert((cxt->action == MNT_ACT_UMOUNT));
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	rc = do_umount(cxt);
+	if (rc)
+		goto end;
+
+	if (mnt_context_get_status(cxt) && !mnt_context_is_fake(cxt)) {
+		/*
+		 * Umounted, do some post-umount operations
+		 *	- remove loopdev
+		 *	- refresh in-memory mtab stuff if remount rather than
+		 *	  umount has been performed
+		 */
+		if (mnt_context_is_loopdel(cxt)
+		    && !(cxt->mountflags & MS_REMOUNT))
+			rc = mnt_context_delete_loopdev(cxt);
+
+		if (!mnt_context_is_nomtab(cxt)
+		    && mnt_context_get_status(cxt)
+		    && !cxt->helper
+		    && mnt_context_is_rdonly_umount(cxt)
+		    && (cxt->mountflags & MS_REMOUNT)) {
+
+			/* use "remount" instead of "umount" in /etc/mtab */
+			if (!rc && cxt->update && mnt_context_mtab_writable(cxt))
+				rc = mnt_update_set_fs(cxt->update,
+						       cxt->mountflags, NULL, cxt->fs);
+		}
+	}
+end:
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+/**
+ * mnt_context_finalize_umount:
+ * @cxt: context
+ *
+ * Mtab update, etc. Unnecessary for mnt_context_umount(), but should be called
+ * after mnt_context_do_umount(). See also mnt_context_set_syscall_status().
+ *
+ * Returns: negative number on error, 0 on success.
+ */
+int mnt_context_finalize_umount(struct libmnt_context *cxt)
+{
+	int rc;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_PREPARED));
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);
+	return rc;
+}
+
+
+/**
+ * mnt_context_umount:
+ * @cxt: umount context
+ *
+ * High-level, umounts filesystem by umount(2) or fork()+exec(/sbin/umount.type).
+ *
+ * This is similar to:
+ *
+ *	mnt_context_prepare_umount(cxt);
+ *	mnt_context_do_umount(cxt);
+ *	mnt_context_finalize_umount(cxt);
+ *
+ * See also mnt_context_disable_helpers().
+ *
+ * WARNING: non-zero return code does not mean that umount(2) syscall or
+ *          umount.type helper wasn't successfully called.
+ *
+ *          Check mnt_context_get_status() after error!
+ *
+ * Returns: 0 on success;
+ *         >0 in case of umount(2) error (returns syscall errno),
+ *         <0 in case of other errors.
+ */
+int mnt_context_umount(struct libmnt_context *cxt)
+{
+	int rc;
+	struct libmnt_ns *ns_old;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+
+	DBG(CXT, ul_debugobj(cxt, "umount: %s", mnt_context_get_target(cxt)));
+
+	ns_old = mnt_context_switch_target_ns(cxt);
+	if (!ns_old)
+		return -MNT_ERR_NAMESPACE;
+
+	rc = mnt_context_prepare_umount(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_do_umount(cxt);
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);
+
+	if (!mnt_context_switch_ns(cxt, ns_old))
+		return -MNT_ERR_NAMESPACE;
+
+	return rc;
+}
+
+
+/**
+ * mnt_context_next_umount:
+ * @cxt: context
+ * @itr: iterator
+ * @fs: returns the current filesystem
+ * @mntrc: returns the return code from mnt_context_umount()
+ * @ignored: returns 1 for not matching
+ *
+ * This function tries to umount the next filesystem from mtab (as returned by
+ * mnt_context_get_mtab()).
+ *
+ * You can filter out filesystems by:
+ *	mnt_context_set_options_pattern() to simulate umount -a -O pattern
+ *	mnt_context_set_fstype_pattern()  to simulate umount -a -t pattern
+ *
+ * If the filesystem is not mounted or does not match the defined criteria,
+ * then the function mnt_context_next_umount() returns zero, but the @ignored is
+ * non-zero. Note that the root filesystem is always ignored.
+ *
+ * If umount(2) syscall or umount.type helper failed, then the
+ * mnt_context_next_umount() function returns zero, but the @mntrc is non-zero.
+ * Use also mnt_context_get_status() to check if the filesystem was
+ * successfully umounted.
+ *
+ * Returns: 0 on success,
+ *         <0 in case of error (!= umount(2) errors)
+ *          1 at the end of the list.
+ */
+int mnt_context_next_umount(struct libmnt_context *cxt,
+			   struct libmnt_iter *itr,
+			   struct libmnt_fs **fs,
+			   int *mntrc,
+			   int *ignored)
+{
+	struct libmnt_table *mtab;
+	const char *tgt;
+	int rc;
+
+	if (ignored)
+		*ignored = 0;
+	if (mntrc)
+		*mntrc = 0;
+
+	if (!cxt || !fs || !itr)
+		return -EINVAL;
+
+	rc = mnt_context_get_mtab(cxt, &mtab);
+	cxt->mtab = NULL;		/* do not reset mtab */
+	mnt_reset_context(cxt);
+
+	if (rc)
+		return rc;
+
+	cxt->mtab = mtab;
+
+	do {
+		rc = mnt_table_next_fs(mtab, itr, fs);
+		if (rc != 0)
+			return rc;	/* no more filesystems (or error) */
+
+		tgt = mnt_fs_get_target(*fs);
+	} while (!tgt);
+
+	DBG(CXT, ul_debugobj(cxt, "next-umount: trying %s [fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]", tgt,
+				 mnt_fs_get_fstype(*fs), cxt->fstype_pattern, mnt_fs_get_options(*fs), cxt->optstr_pattern));
+
+	/* ignore filesystems which don't match options patterns */
+	if ((cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
+					cxt->fstype_pattern)) ||
+
+	/* ignore filesystems which don't match type patterns */
+	   (cxt->optstr_pattern && !mnt_fs_match_options(*fs,
+					cxt->optstr_pattern))) {
+		if (ignored)
+			*ignored = 1;
+
+		DBG(CXT, ul_debugobj(cxt, "next-umount: not-match"));
+		return 0;
+	}
+
+	rc = mnt_context_set_fs(cxt, *fs);
+	if (rc)
+		return rc;
+	rc = mnt_context_umount(cxt);
+	if (mntrc)
+		*mntrc = rc;
+	return 0;
+}
+
+
+int mnt_context_get_umount_excode(
+			struct libmnt_context *cxt,
+			int rc,
+			char *buf,
+			size_t bufsz)
+{
+	if (mnt_context_helper_executed(cxt))
+		/*
+		 * /sbin/umount.<type> called, return status
+		 */
+		return mnt_context_get_helper_status(cxt);
+
+	if (rc == 0 && mnt_context_get_status(cxt) == 1)
+		/*
+		 * Libmount success && syscall success.
+		 */
+		return MNT_EX_SUCCESS;
+
+	if (!mnt_context_syscall_called(cxt)) {
+		/*
+		 * libmount errors (extra library checks)
+		 */
+		if (rc == -EPERM && !mnt_context_tab_applied(cxt)) {
+			/* failed to evaluate permissions because not found
+			 * relevant entry in mtab */
+			if (buf)
+				snprintf(buf, bufsz, _("not mounted"));
+			return MNT_EX_USAGE;
+		}
+
+		if (rc == -MNT_ERR_LOCK) {
+			if (buf)
+				snprintf(buf, bufsz, _("locking failed"));
+			return MNT_EX_FILEIO;
+		}
+
+		if (rc == -MNT_ERR_NAMESPACE) {
+			if (buf)
+				snprintf(buf, bufsz, _("failed to switch namespace"));
+			return MNT_EX_SYSERR;
+		}
+		return mnt_context_get_generic_excode(rc, buf, bufsz,
+					_("umount failed: %m"));
+
+	} if (mnt_context_get_syscall_errno(cxt) == 0) {
+		/*
+		 * umount(2) syscall success, but something else failed
+		 * (probably error in mtab processing).
+		 */
+		if (rc == -MNT_ERR_LOCK) {
+			if (buf)
+				snprintf(buf, bufsz, _("filesystem was unmounted, but failed to update userspace mount table"));
+			return MNT_EX_FILEIO;
+		}
+
+		if (rc == -MNT_ERR_NAMESPACE) {
+			if (buf)
+				snprintf(buf, bufsz, _("filesystem was unmounted, but failed to switch namespace back"));
+			return MNT_EX_SYSERR;
+
+		}
+
+		if (rc < 0)
+			return mnt_context_get_generic_excode(rc, buf, bufsz,
+				_("filesystem was unmounted, but any subsequent operation failed: %m"));
+
+		return MNT_EX_SOFTWARE;	/* internal error */
+	}
+
+	/*
+	 * umount(2) errors
+	 */
+	if (buf) {
+		int syserr = mnt_context_get_syscall_errno(cxt);
+
+		switch (syserr) {
+		case ENXIO:
+			snprintf(buf, bufsz, _("invalid block device"));	/* ??? */
+			break;
+		case EINVAL:
+			snprintf(buf, bufsz, _("not mounted"));
+			break;
+		case EIO:
+			snprintf(buf, bufsz, _("can't write superblock"));
+			break;
+		case EBUSY:
+			snprintf(buf, bufsz, _("target is busy"));
+			break;
+		case ENOENT:
+			snprintf(buf, bufsz, _("no mount point specified"));
+			break;
+		case EPERM:
+			snprintf(buf, bufsz, _("must be superuser to unmount"));
+			break;
+		case EACCES:
+			snprintf(buf, bufsz, _("block devices are not permitted on filesystem"));
+			break;
+		default:
+			return mnt_context_get_generic_excode(syserr, buf, bufsz,_("umount(2) system call failed: %m"));
+		}
+	}
+	return MNT_EX_FAIL;
+}
diff --git a/libmount/src/context_veritydev.c b/libmount/src/context_veritydev.c
new file mode 100644
index 0000000..d663456
--- /dev/null
+++ b/libmount/src/context_veritydev.c
@@ -0,0 +1,520 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2019 Microsoft Corporation
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "mountP.h"
+
+#if defined(HAVE_CRYPTSETUP)
+
+#ifdef CRYPTSETUP_VIA_DLOPEN
+#include <dlfcn.h>
+#endif
+#include <libcryptsetup.h>
+#include "path.h"
+
+#ifdef CRYPTSETUP_VIA_DLOPEN
+static void *get_symbol(struct libmnt_context *cxt, void *dl, const char *name, int *rc)
+{
+	char *dl_error = NULL;
+	void *sym = dlsym(dl, name);
+
+	*rc = 0;
+	if ((dl_error = dlerror()) == NULL)
+		return sym;
+
+	DBG(VERITY, ul_debugobj(cxt, "veritydev specific options detected but cannot dlopen symbol %s: %s", name, dl_error));
+	*rc = -ENOTSUP;
+
+	return NULL;
+}
+#endif
+
+/* Taken from https://gitlab.com/cryptsetup/cryptsetup/blob/master/lib/utils_crypt.c#L225 */
+static size_t crypt_hex_to_bytes(const char *hex, char **result)
+{
+	char buf[3] = "xx\0", *endp, *bytes;
+	size_t i, len;
+
+	len = strlen(hex);
+	if (len % 2)
+		return -EINVAL;
+	len /= 2;
+
+	bytes = malloc(len);
+	if (!bytes)
+		return -ENOMEM;
+
+	for (i = 0; i < len; i++) {
+		memcpy(buf, &hex[i * 2], 2);
+		bytes[i] = strtoul(buf, &endp, 16);
+		if (endp != &buf[2]) {
+			free(bytes);
+			return -EINVAL;
+		}
+	}
+	*result = bytes;
+	return i;
+}
+
+
+int mnt_context_setup_veritydev(struct libmnt_context *cxt)
+{
+	const char *backing_file, *optstr;
+	char *val = NULL, *key = NULL, *root_hash_binary = NULL, *mapper_device = NULL,
+		*mapper_device_full = NULL, *backing_file_basename = NULL, *root_hash = NULL,
+		*hash_device = NULL, *root_hash_file = NULL, *fec_device = NULL, *hash_sig = NULL;
+	size_t len, hash_size, hash_sig_size = 0, keysize = 0;
+	struct crypt_params_verity crypt_params = {};
+	struct crypt_device *crypt_dev = NULL;
+	int rc = 0;
+	/* Use the same default for FEC parity bytes as cryptsetup uses */
+	uint64_t offset = 0, fec_offset = 0, fec_roots = 2;
+	struct stat hash_sig_st;
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	/* To avoid linking libmount to libcryptsetup, and keep the default dependencies list down, use dlopen */
+	void *dl = NULL;
+	int (*sym_crypt_init_data_device)(struct crypt_device **, const char *, const char *) = NULL;
+	int (*sym_crypt_load)(struct crypt_device *, const char *, void *) = NULL;
+	int (*sym_crypt_get_volume_key_size)(struct crypt_device *) = NULL;
+#ifdef HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+	int (*sym_crypt_activate_by_signed_key)(struct crypt_device *, const char *, const char *, size_t, const char *, size_t, uint32_t) = NULL;
+#endif
+	int (*sym_crypt_activate_by_volume_key)(struct crypt_device *, const char *, const char *, size_t, uint32_t) = NULL;
+	void (*sym_crypt_free)(struct crypt_device *) = NULL;
+	int (*sym_crypt_init_by_name)(struct crypt_device **, const char *) = NULL;
+	int (*sym_crypt_get_verity_info)(struct crypt_device *, struct crypt_params_verity *) = NULL;
+	int (*sym_crypt_volume_key_get)(struct crypt_device *, int, char *, size_t *, const char *, size_t) = NULL;
+#else
+	int (*sym_crypt_init_data_device)(struct crypt_device **, const char *, const char *) = &crypt_init_data_device;
+	int (*sym_crypt_load)(struct crypt_device *, const char *, void *) = &crypt_load;
+	int (*sym_crypt_get_volume_key_size)(struct crypt_device *) = &crypt_get_volume_key_size;
+#ifdef HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+	int (*sym_crypt_activate_by_signed_key)(struct crypt_device *, const char *, const char *, size_t, const char *, size_t, uint32_t) = &crypt_activate_by_signed_key;
+#endif
+	int (*sym_crypt_activate_by_volume_key)(struct crypt_device *, const char *, const char *, size_t, uint32_t) = &crypt_activate_by_volume_key;
+	void (*sym_crypt_free)(struct crypt_device *) = &crypt_free;
+	int (*sym_crypt_init_by_name)(struct crypt_device **, const char *) = &crypt_init_by_name;
+	int (*sym_crypt_get_verity_info)(struct crypt_device *, struct crypt_params_verity *) = &crypt_get_verity_info;
+	int (*sym_crypt_volume_key_get)(struct crypt_device *, int, char *, size_t *, const char *, size_t) = &crypt_volume_key_get;
+#endif
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	/* dm-verity volumes are read-only, and mount will fail if not set */
+	mnt_context_set_mflags(cxt, (cxt->mountflags | MS_RDONLY));
+
+	backing_file = mnt_fs_get_srcpath(cxt->fs);
+	if (!backing_file)
+		return -EINVAL;
+
+	/* To avoid clashes, prefix libmnt_ to all mapper devices */
+	backing_file_basename = basename(backing_file);
+	mapper_device = calloc(strlen(backing_file_basename) + strlen("libmnt_") + 1, sizeof(char));
+	if (!mapper_device)
+		return -ENOMEM;
+	strcat(mapper_device, "libmnt_");
+	strcat(mapper_device, backing_file_basename);
+
+	DBG(VERITY, ul_debugobj(cxt, "trying to setup verity device for %s", backing_file));
+
+	optstr = mnt_fs_get_user_options(cxt->fs);
+
+	/*
+	 * verity.hashdevice=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_HASH_DEVICE) &&
+	    mnt_optstr_get_option(optstr, "verity.hashdevice", &val, &len) == 0 && val) {
+		hash_device = strndup(val, len);
+		rc = hash_device ? 0 : -ENOMEM;
+	}
+
+	/*
+	 * verity.roothash=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_ROOT_HASH) &&
+	    mnt_optstr_get_option(optstr, "verity.roothash", &val, &len) == 0 && val) {
+		root_hash = strndup(val, len);
+		rc = root_hash ? 0 : -ENOMEM;
+	}
+
+	/*
+	 * verity.hashoffset=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_HASH_OFFSET) &&
+	    mnt_optstr_get_option(optstr, "verity.hashoffset", &val, &len) == 0) {
+		rc = mnt_parse_offset(val, len, &offset);
+		if (rc) {
+			DBG(VERITY, ul_debugobj(cxt, "failed to parse verity.hashoffset="));
+			rc = -MNT_ERR_MOUNTOPT;
+		}
+	}
+
+	/*
+	 * verity.roothashfile=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_ROOT_HASH_FILE) &&
+	    mnt_optstr_get_option(optstr, "verity.roothashfile", &val, &len) == 0 && val) {
+		root_hash_file = strndup(val, len);
+		rc = root_hash_file ? 0 : -ENOMEM;
+	}
+
+	/*
+	 * verity.fecdevice=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_FEC_DEVICE) &&
+	    mnt_optstr_get_option(optstr, "verity.fecdevice", &val, &len) == 0 && val) {
+		fec_device = strndup(val, len);
+		rc = fec_device ? 0 : -ENOMEM;
+	}
+
+	/*
+	 * verity.fecoffset=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_FEC_OFFSET) &&
+	    mnt_optstr_get_option(optstr, "verity.fecoffset", &val, &len) == 0) {
+		rc = mnt_parse_offset(val, len, &fec_offset);
+		if (rc) {
+			DBG(VERITY, ul_debugobj(cxt, "failed to parse verity.fecoffset="));
+			rc = -MNT_ERR_MOUNTOPT;
+		}
+	}
+
+	/*
+	 * verity.fecroots=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_FEC_ROOTS) &&
+	    mnt_optstr_get_option(optstr, "verity.fecroots", &val, &len) == 0) {
+		rc = mnt_parse_offset(val, len, &fec_roots);
+		if (rc) {
+			DBG(VERITY, ul_debugobj(cxt, "failed to parse verity.fecroots="));
+			rc = -MNT_ERR_MOUNTOPT;
+		}
+	}
+
+	/*
+	 * verity.roothashsig=
+	 */
+	if (rc == 0 && (cxt->user_mountflags & MNT_MS_ROOT_HASH_SIG) &&
+	    mnt_optstr_get_option(optstr, "verity.roothashsig", &val, &len) == 0 && val) {
+		rc = ul_path_stat(NULL, &hash_sig_st, val);
+		if (rc == 0)
+			rc = !S_ISREG(hash_sig_st.st_mode) || !hash_sig_st.st_size ? -EINVAL : 0;
+		if (rc == 0) {
+			hash_sig_size = hash_sig_st.st_size;
+			hash_sig = malloc(hash_sig_size);
+			rc = hash_sig ? 0 : -ENOMEM;
+		}
+		if (rc == 0) {
+			rc = ul_path_read(NULL, hash_sig, hash_sig_size, val);
+			rc = rc < (int)hash_sig_size ? -1 : 0;
+		}
+	}
+
+	if (!rc && root_hash && root_hash_file) {
+		DBG(VERITY, ul_debugobj(cxt, "verity.roothash and verity.roothashfile are mutually exclusive"));
+		rc = -EINVAL;
+	} else if (!rc && root_hash_file) {
+		rc = ul_path_read_string(NULL, &root_hash, root_hash_file);
+		rc = rc < 1 ? rc : 0;
+	}
+
+	if (!rc && (!hash_device || !root_hash)) {
+		DBG(VERITY, ul_debugobj(cxt, "verity.hashdevice and one of verity.roothash or verity.roothashfile are mandatory"));
+		rc = -EINVAL;
+	}
+
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	if (rc == 0) {
+		int dl_flags = RTLD_LAZY | RTLD_LOCAL;
+		/* glibc extension: mnt_context_deferred_delete_veritydev is called immediately after, don't unload on dl_close */
+#ifdef RTLD_NODELETE
+		dl_flags |= RTLD_NODELETE;
+#endif
+		/* glibc extension: might help to avoid further symbols clashes */
+#ifdef RTLD_DEEPBIND
+		dl_flags |= RTLD_DEEPBIND;
+#endif
+		dl = dlopen("libcryptsetup.so.12", dl_flags);
+		if (!dl) {
+			DBG(VERITY, ul_debugobj(cxt, "veritydev specific options detected but cannot dlopen libcryptsetup"));
+			rc = -ENOTSUP;
+		}
+	}
+
+	/* clear errors first, then load all the libcryptsetup symbols */
+	dlerror();
+
+	if (rc == 0)
+		*(void **)(&sym_crypt_init_data_device) = get_symbol(cxt, dl, "crypt_init_data_device", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_load) = get_symbol(cxt, dl, "crypt_load", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_get_volume_key_size) = get_symbol(cxt, dl, "crypt_get_volume_key_size", &rc);
+#ifdef HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+	if (rc == 0)
+		*(void **)(&sym_crypt_activate_by_signed_key) = get_symbol(cxt, dl, "crypt_activate_by_signed_key", &rc);
+#endif
+	if (rc == 0)
+		*(void **)(&sym_crypt_activate_by_volume_key) = get_symbol(cxt, dl, "crypt_activate_by_volume_key", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_free) = get_symbol(cxt, dl, "crypt_free", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_init_by_name) = get_symbol(cxt, dl, "crypt_init_by_name", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_get_verity_info) = get_symbol(cxt, dl, "crypt_get_verity_info", &rc);
+	if (rc == 0)
+		*(void **)(&sym_crypt_volume_key_get) = get_symbol(cxt, dl, "crypt_volume_key_get", &rc);
+#endif
+	if (rc)
+		goto done;
+
+	rc = (*sym_crypt_init_data_device)(&crypt_dev, hash_device, backing_file);
+	if (rc)
+		goto done;
+
+	memset(&crypt_params, 0, sizeof(struct crypt_params_verity));
+	crypt_params.hash_area_offset = offset;
+	crypt_params.fec_area_offset = fec_offset;
+	crypt_params.fec_roots = fec_roots;
+	crypt_params.fec_device = fec_device;
+	crypt_params.flags = 0;
+	rc = (*sym_crypt_load)(crypt_dev, CRYPT_VERITY, &crypt_params);
+	if (rc < 0)
+		goto done;
+
+	hash_size = (*sym_crypt_get_volume_key_size)(crypt_dev);
+	if (crypt_hex_to_bytes(root_hash, &root_hash_binary) != hash_size) {
+		DBG(VERITY, ul_debugobj(cxt, "root hash %s is not of length %zu", root_hash, hash_size));
+		rc = -EINVAL;
+		goto done;
+	}
+	if (hash_sig) {
+#ifdef HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+		rc = (*sym_crypt_activate_by_signed_key)(crypt_dev, mapper_device, root_hash_binary, hash_size,
+				hash_sig, hash_sig_size, CRYPT_ACTIVATE_READONLY);
+#else
+		rc = -EINVAL;
+		DBG(VERITY, ul_debugobj(cxt, "verity.roothashsig=%s passed but libcryptsetup does not provide crypt_activate_by_signed_key()", hash_sig));
+#endif
+	} else
+		rc = (*sym_crypt_activate_by_volume_key)(crypt_dev, mapper_device, root_hash_binary, hash_size,
+				CRYPT_ACTIVATE_READONLY);
+	/*
+	 * If the mapper device already exists, and if libcryptsetup supports it, get the root
+	 * hash associated with the existing one and compare it with the parameter passed by
+	 * the user. If they match, then we can be sure the user intended to mount the exact
+	 * same device, and simply reuse it and return success.
+	 * The kernel does the refcounting for us.
+	 * If libcryptsetup does not support getting the root hash out of an existing device,
+	 * then return an error and tell the user that the device is already in use.
+	 * Pass through only OOM errors or mismatching root hash errors.
+	 */
+	if (rc == -EEXIST) {
+		DBG(VERITY, ul_debugobj(cxt, "%s already in use as /dev/mapper/%s", backing_file, mapper_device));
+		(*sym_crypt_free)(crypt_dev);
+		rc = (*sym_crypt_init_by_name)(&crypt_dev, mapper_device);
+		if (!rc) {
+			rc = (*sym_crypt_get_verity_info)(crypt_dev, &crypt_params);
+			if (!rc) {
+				key = calloc(hash_size, 1);
+				if (!key) {
+					rc = -ENOMEM;
+					goto done;
+				}
+			}
+			if (!rc) {
+				keysize = hash_size;
+				rc = (*sym_crypt_volume_key_get)(crypt_dev, CRYPT_ANY_SLOT, key, &keysize, NULL, 0);
+			}
+			if (!rc) {
+				DBG(VERITY, ul_debugobj(cxt, "comparing root hash of existing device with %s", root_hash));
+				if (memcmp(key, root_hash_binary, hash_size)) {
+					DBG(VERITY, ul_debugobj(cxt, "existing device's hash does not match with %s", root_hash));
+					rc = -EINVAL;
+					goto done;
+				}
+			} else {
+				DBG(VERITY, ul_debugobj(cxt, "libcryptsetup does not support extracting root hash of existing device"));
+			}
+		}
+		if (rc) {
+			rc = -EEXIST;
+		} else {
+			/*
+			 * Ensure that, if signatures are supported, we only reuse the device if the previous mount
+			 * used the same settings, so that a previous unsigned mount will not be reused if the user
+			 * asks to use signing for the new one, and viceversa.
+			 */
+#ifdef HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+			if (!!hash_sig != !!(crypt_params.flags & CRYPT_VERITY_ROOT_HASH_SIGNATURE)) {
+				rc = -EINVAL;
+				DBG(VERITY, ul_debugobj(cxt, "existing device and new mount have to either be both opened with signature or both without"));
+				goto done;
+			}
+#endif
+			DBG(VERITY, ul_debugobj(cxt, "root hash of %s matches %s, reusing device", mapper_device, root_hash));
+		}
+	}
+
+	if (!rc) {
+		cxt->flags |= MNT_FL_VERITYDEV_READY;
+		mapper_device_full = calloc(strlen(mapper_device) + strlen("/dev/mapper/") + 1, sizeof(char));
+		if (!mapper_device_full)
+			rc = -ENOMEM;
+		else {
+			strcat(mapper_device_full, "/dev/mapper/");
+			strcat(mapper_device_full, mapper_device);
+			rc = mnt_fs_set_source(cxt->fs, mapper_device_full);
+		}
+	}
+
+done:
+	if (sym_crypt_free)
+		(*sym_crypt_free)(crypt_dev);
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	if (dl)
+		dlclose(dl);
+#endif
+	free(root_hash_binary);
+	free(mapper_device_full);
+	free(mapper_device);
+	free(hash_device);
+	free(root_hash);
+	free(root_hash_file);
+	free(fec_device);
+	free(hash_sig);
+	free(key);
+	return rc;
+}
+
+int mnt_context_deferred_delete_veritydev(struct libmnt_context *cxt)
+{
+	const char *src;
+	struct crypt_device *crypt_dev = NULL;
+	/* If mounting failed delete immediately, otherwise setup auto cleanup for user umount */
+	uint32_t flags = mnt_context_get_status(cxt) ? CRYPT_DEACTIVATE_DEFERRED : 0;
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	void *dl = NULL;
+	int dl_flags = RTLD_LAZY | RTLD_LOCAL;
+	/* glibc extension: might help to avoid further symbols clashes */
+#ifdef RTLD_DEEPBIND
+	dl_flags |= RTLD_DEEPBIND;
+#endif
+	int (*sym_crypt_init_by_name)(struct crypt_device **, const char *) = NULL;
+	int (*sym_crypt_deactivate_by_name)(struct crypt_device *, const char *, uint32_t) = NULL;
+	void (*sym_crypt_free)(struct crypt_device *) = NULL;
+#else
+	int (*sym_crypt_init_by_name)(struct crypt_device **, const char *) = &crypt_init_by_name;
+	int (*sym_crypt_deactivate_by_name)(struct crypt_device *, const char *, uint32_t) = &crypt_deactivate_by_name;
+	void (*sym_crypt_free)(struct crypt_device *) = &crypt_free;
+#endif
+	int rc = 0;
+
+	assert(cxt);
+	assert(cxt->fs);
+
+	if (!(cxt->flags & MNT_FL_VERITYDEV_READY))
+		return 0;
+
+	src = mnt_fs_get_srcpath(cxt->fs);
+	if (!src)
+		return -EINVAL;
+
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	dl = dlopen("libcryptsetup.so.12", dl_flags);
+	if (!dl) {
+		DBG(VERITY, ul_debugobj(cxt, "veritydev specific options detected but cannot dlopen libcryptsetup"));
+		return -ENOTSUP;
+	}
+
+	/* clear errors first */
+	dlerror();
+
+	if (!rc)
+		*(void **)(&sym_crypt_init_by_name) = get_symbol(cxt, dl, "crypt_init_by_name", &rc);
+	if (!rc)
+		*(void **)(&sym_crypt_deactivate_by_name) = get_symbol(cxt, dl, "crypt_deactivate_by_name", &rc);
+	if (!rc)
+		*(void **)(&sym_crypt_free) = get_symbol(cxt, dl, "crypt_free", &rc);
+#endif
+	if (!rc) {
+		rc = (*sym_crypt_init_by_name)(&crypt_dev, src);
+		if (!rc) {
+			rc = (*sym_crypt_deactivate_by_name)(crypt_dev, src, flags);
+			if (!rc)
+				cxt->flags &= ~MNT_FL_VERITYDEV_READY;
+		}
+
+		(*sym_crypt_free)(crypt_dev);
+	}
+
+#ifdef CRYPTSETUP_VIA_DLOPEN
+	dlclose(dl);
+#endif
+	DBG(VERITY, ul_debugobj(cxt, "deleted [rc=%d]", rc));
+	return rc;
+}
+
+#else
+
+int mnt_context_setup_veritydev(struct libmnt_context *cxt __attribute__ ((__unused__)))
+{
+	return 0;
+}
+
+int mnt_context_deferred_delete_veritydev(struct libmnt_context *cxt __attribute__ ((__unused__)))
+{
+	return 0;
+}
+#endif
+
+int mnt_context_is_veritydev(struct libmnt_context *cxt)
+{
+	const char *src;
+
+	assert(cxt);
+
+	/* The mount flags have to be merged, otherwise we have to use
+	 * expensive mnt_context_get_user_mflags() instead of cxt->user_mountflags. */
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+
+	if (!cxt->fs)
+		return 0;
+	src = mnt_fs_get_srcpath(cxt->fs);
+	if (!src)
+		return 0;		/* backing file not set */
+
+	if (cxt->user_mountflags & (MNT_MS_HASH_DEVICE |
+				    MNT_MS_ROOT_HASH |
+				    MNT_MS_HASH_OFFSET)) {
+#ifndef HAVE_CRYPTSETUP
+		DBG(VERITY, ul_debugobj(cxt, "veritydev specific options detected but libmount built without libcryptsetup"));
+		return -ENOTSUP;
+#else
+		DBG(VERITY, ul_debugobj(cxt, "veritydev specific options detected"));
+		return 1;
+#endif
+	}
+
+	if (!strncmp(src, "/dev/mapper/libmnt_", strlen("/dev/mapper/libmnt_"))) {
+#ifndef HAVE_CRYPTSETUP
+		DBG(VERITY, ul_debugobj(cxt, "veritydev prefix detected in source device but libmount built without libcryptsetup"));
+		return -ENOTSUP;
+#else
+		DBG(VERITY, ul_debugobj(cxt, "veritydev prefix detected in source device"));
+		return 1;
+#endif
+	}
+
+	return 0;
+}
diff --git a/libmount/src/fs.c b/libmount/src/fs.c
new file mode 100644
index 0000000..52f937a
--- /dev/null
+++ b/libmount/src/fs.c
@@ -0,0 +1,1624 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: fs
+ * @title: Filesystem
+ * @short_description: represents one entry from fstab, mtab, or mountinfo file
+ *
+ */
+#include <ctype.h>
+#include <blkid.h>
+#include <stddef.h>
+
+#include "mountP.h"
+#include "strutils.h"
+
+/**
+ * mnt_new_fs:
+ *
+ * The initial refcount is 1, and needs to be decremented to
+ * release the resources of the filesystem.
+ *
+ * Returns: newly allocated struct libmnt_fs.
+ */
+struct libmnt_fs *mnt_new_fs(void)
+{
+	struct libmnt_fs *fs = calloc(1, sizeof(*fs));
+	if (!fs)
+		return NULL;
+
+	fs->refcount = 1;
+	INIT_LIST_HEAD(&fs->ents);
+	DBG(FS, ul_debugobj(fs, "alloc"));
+	return fs;
+}
+
+/**
+ * mnt_free_fs:
+ * @fs: fs pointer
+ *
+ * Deallocates the fs. This function does not care about reference count. Don't
+ * use this function directly -- it's better to use mnt_unref_fs().
+ *
+ * The reference counting is supported since util-linux v2.24.
+ */
+void mnt_free_fs(struct libmnt_fs *fs)
+{
+	if (!fs)
+		return;
+
+	DBG(FS, ul_debugobj(fs, "free [refcount=%d]", fs->refcount));
+
+	mnt_reset_fs(fs);
+	free(fs);
+}
+
+/**
+ * mnt_reset_fs:
+ * @fs: fs pointer
+ *
+ * Resets (zeroize) @fs.
+ */
+void mnt_reset_fs(struct libmnt_fs *fs)
+{
+	int ref;
+
+	if (!fs)
+		return;
+
+	ref = fs->refcount;
+
+	list_del(&fs->ents);
+	free(fs->source);
+	free(fs->bindsrc);
+	free(fs->tagname);
+	free(fs->tagval);
+	free(fs->root);
+	free(fs->swaptype);
+	free(fs->target);
+	free(fs->fstype);
+	free(fs->optstr);
+	free(fs->vfs_optstr);
+	free(fs->fs_optstr);
+	free(fs->user_optstr);
+	free(fs->attrs);
+	free(fs->opt_fields);
+	free(fs->comment);
+
+	memset(fs, 0, sizeof(*fs));
+	INIT_LIST_HEAD(&fs->ents);
+	fs->refcount = ref;
+}
+
+/**
+ * mnt_ref_fs:
+ * @fs: fs pointer
+ *
+ * Increments reference counter.
+ */
+void mnt_ref_fs(struct libmnt_fs *fs)
+{
+	if (fs) {
+		fs->refcount++;
+		/*DBG(FS, ul_debugobj(fs, "ref=%d", fs->refcount));*/
+	}
+}
+
+/**
+ * mnt_unref_fs:
+ * @fs: fs pointer
+ *
+ * De-increments reference counter, on zero the @fs is automatically
+ * deallocated by mnt_free_fs().
+ */
+void mnt_unref_fs(struct libmnt_fs *fs)
+{
+	if (fs) {
+		fs->refcount--;
+		/*DBG(FS, ul_debugobj(fs, "unref=%d", fs->refcount));*/
+		if (fs->refcount <= 0)
+			mnt_free_fs(fs);
+	}
+}
+
+static inline int update_str(char **dest, const char *src)
+{
+	size_t sz;
+	char *x;
+
+	assert(dest);
+
+	if (!src) {
+		free(*dest);
+		*dest = NULL;
+		return 0;	/* source (old) is empty */
+	}
+
+	sz = strlen(src) + 1;
+	x = realloc(*dest, sz);
+	if (!x)
+		return -ENOMEM;
+	*dest = x;
+	memcpy(*dest, src, sz);
+	return 0;
+}
+
+/* This function do NOT overwrite (replace) the string in @new, the string in
+ * the @new has to be NULL otherwise this is no-op */
+static inline int cpy_str_at_offset(void *new, const void *old, size_t offset)
+{
+	char **o = (char **) ((char *) old + offset);
+	char **n = (char **) ((char *) new + offset);
+
+	if (*n)
+		return 0;	/* already set, don't overwrite */
+
+	return update_str(n, *o);
+}
+
+/**
+ * mnt_copy_fs:
+ * @dest: destination FS
+ * @src: source FS
+ *
+ * If @dest is NULL, then a new FS is allocated, if any @dest field is already
+ * set, then the field is NOT overwritten.
+ *
+ * This function does not copy userdata (se mnt_fs_set_userdata()). A new copy is
+ * not linked with any existing mnt_tab.
+ *
+ * Returns: @dest or NULL in case of error
+ */
+struct libmnt_fs *mnt_copy_fs(struct libmnt_fs *dest,
+			      const struct libmnt_fs *src)
+{
+	const struct libmnt_fs *org = dest;
+
+	if (!src)
+		return NULL;
+	if (!dest) {
+		dest = mnt_new_fs();
+		if (!dest)
+			return NULL;
+
+		dest->tab	 = NULL;
+	}
+
+	dest->id         = src->id;
+	dest->parent     = src->parent;
+	dest->devno      = src->devno;
+	dest->tid        = src->tid;
+
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, source)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, tagname)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, tagval)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, root)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, swaptype)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, target)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, fstype)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, optstr)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, vfs_optstr)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, fs_optstr)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, user_optstr)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, attrs)))
+		goto err;
+	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, bindsrc)))
+		goto err;
+
+	dest->freq       = src->freq;
+	dest->passno     = src->passno;
+	dest->flags      = src->flags;
+	dest->size	 = src->size;
+	dest->usedsize   = src->usedsize;
+	dest->priority   = src->priority;
+
+	return dest;
+err:
+	if (!org)
+		mnt_free_fs(dest);
+	return NULL;
+}
+
+/*
+ * This function copies all @fs description except information that does not
+ * belong to /etc/mtab (e.g. VFS and userspace mount options with MNT_NOMTAB
+ * mask).
+ *
+ * Returns: copy of @fs.
+ */
+struct libmnt_fs *mnt_copy_mtab_fs(const struct libmnt_fs *fs)
+{
+	struct libmnt_fs *n = mnt_new_fs();
+
+	assert(fs);
+	if (!n)
+		return NULL;
+
+	if (strdup_between_structs(n, fs, source))
+		goto err;
+	if (strdup_between_structs(n, fs, target))
+		goto err;
+	if (strdup_between_structs(n, fs, fstype))
+		goto err;
+
+	if (fs->vfs_optstr) {
+		char *p = NULL;
+		mnt_optstr_get_options(fs->vfs_optstr, &p,
+				mnt_get_builtin_optmap(MNT_LINUX_MAP),
+				MNT_NOMTAB);
+		n->vfs_optstr = p;
+	}
+
+	if (fs->user_optstr) {
+		char *p = NULL;
+		mnt_optstr_get_options(fs->user_optstr, &p,
+				mnt_get_builtin_optmap(MNT_USERSPACE_MAP),
+				MNT_NOMTAB);
+		n->user_optstr = p;
+	}
+
+	if (strdup_between_structs(n, fs, fs_optstr))
+		goto err;
+
+	/* we cannot copy original optstr, the new optstr has to be without
+	 * non-mtab options -- so, let's generate a new string */
+	n->optstr = mnt_fs_strdup_options(n);
+
+	n->freq       = fs->freq;
+	n->passno     = fs->passno;
+	n->flags      = fs->flags;
+
+	return n;
+err:
+	mnt_free_fs(n);
+	return NULL;
+
+}
+
+/**
+ * mnt_fs_get_userdata:
+ * @fs: struct libmnt_file instance
+ *
+ * Returns: private data set by mnt_fs_set_userdata() or NULL.
+ */
+void *mnt_fs_get_userdata(struct libmnt_fs *fs)
+{
+	if (!fs)
+		return NULL;
+	return fs->userdata;
+}
+
+/**
+ * mnt_fs_set_userdata:
+ * @fs: struct libmnt_file instance
+ * @data: user data
+ *
+ * The "userdata" are library independent data.
+ *
+ * Returns: 0 or negative number in case of error (if @fs is NULL).
+ */
+int mnt_fs_set_userdata(struct libmnt_fs *fs, void *data)
+{
+	if (!fs)
+		return -EINVAL;
+	fs->userdata = data;
+	return 0;
+}
+
+/**
+ * mnt_fs_get_srcpath:
+ * @fs: struct libmnt_file (fstab/mtab/mountinfo) fs
+ *
+ * The mount "source path" is:
+ * - a directory for 'bind' mounts (in fstab or mtab only)
+ * - a device name for standard mounts
+ *
+ * See also mnt_fs_get_tag() and mnt_fs_get_source().
+ *
+ * Returns: mount source path or NULL in case of error or when the path
+ * is not defined.
+ */
+const char *mnt_fs_get_srcpath(struct libmnt_fs *fs)
+{
+	if (!fs)
+		return NULL;
+
+	/* fstab-like fs */
+	if (fs->tagname)
+		return NULL;	/* the source contains a "NAME=value" */
+	return fs->source;
+}
+
+/**
+ * mnt_fs_get_source:
+ * @fs: struct libmnt_file (fstab/mtab/mountinfo) fs
+ *
+ * Returns: mount source. Note that the source could be unparsed TAG
+ * (LABEL/UUID). See also mnt_fs_get_srcpath() and mnt_fs_get_tag().
+ */
+const char *mnt_fs_get_source(struct libmnt_fs *fs)
+{
+	return fs ? fs->source : NULL;
+}
+
+/*
+ * Used by the parser ONLY (@source has to be freed on error)
+ */
+int __mnt_fs_set_source_ptr(struct libmnt_fs *fs, char *source)
+{
+	char *t = NULL, *v = NULL;
+
+	assert(fs);
+
+	if (source && blkid_parse_tag_string(source, &t, &v) == 0 &&
+	    !mnt_valid_tagname(t)) {
+		/* parsable but unknown tag -- ignore */
+		free(t);
+		free(v);
+		t = v = NULL;
+	}
+
+	if (fs->source != source)
+		free(fs->source);
+
+	free(fs->tagname);
+	free(fs->tagval);
+
+	fs->source = source;
+	fs->tagname = t;
+	fs->tagval = v;
+	return 0;
+}
+
+/**
+ * mnt_fs_set_source:
+ * @fs: fstab/mtab/mountinfo entry
+ * @source: new source
+ *
+ * This function creates a private copy (strdup()) of @source.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_source(struct libmnt_fs *fs, const char *source)
+{
+	char *p = NULL;
+	int rc;
+
+	if (!fs)
+		return -EINVAL;
+
+	if (source) {
+		p = strdup(source);
+		if (!p)
+			return -ENOMEM;
+	}
+
+	rc = __mnt_fs_set_source_ptr(fs, p);
+	if (rc)
+		free(p);
+	return rc;
+}
+
+/**
+ * mnt_fs_streq_srcpath:
+ * @fs: fs
+ * @path: source path
+ *
+ * Compares @fs source path with @path. The redundant slashes are ignored.
+ * This function compares strings and does not canonicalize the paths.
+ * See also more heavy and generic mnt_fs_match_source().
+ *
+ * Returns: 1 if @fs source path equal to @path, otherwise 0.
+ */
+int mnt_fs_streq_srcpath(struct libmnt_fs *fs, const char *path)
+{
+	const char *p;
+
+	if (!fs)
+		return 0;
+
+	p = mnt_fs_get_srcpath(fs);
+
+	if (!mnt_fs_is_pseudofs(fs))
+		return streq_paths(p, path);
+
+	if (!p && !path)
+		return 1;
+
+	return p && path && strcmp(p, path) == 0;
+}
+
+/**
+ * mnt_fs_get_table:
+ * @fs: table entry
+ * @tb: table that contains @fs
+ *
+ * Returns: 0 or negative number on error (if @fs or @tb is NULL).
+ *
+ * Since: 2.34
+ */
+int mnt_fs_get_table(struct libmnt_fs *fs, struct libmnt_table **tb)
+{
+	if (!fs || !tb)
+		return -EINVAL;
+
+	*tb = fs->tab;
+	return 0;
+}
+
+/**
+ * mnt_fs_streq_target:
+ * @fs: fs
+ * @path: mount point
+ *
+ * Compares @fs target path with @path. The redundant slashes are ignored.
+ * This function compares strings and does not canonicalize the paths.
+ * See also more generic mnt_fs_match_target().
+ *
+ * Returns: 1 if @fs target path equal to @path, otherwise 0.
+ */
+int mnt_fs_streq_target(struct libmnt_fs *fs, const char *path)
+{
+	return fs && streq_paths(mnt_fs_get_target(fs), path);
+}
+
+/**
+ * mnt_fs_get_tag:
+ * @fs: fs
+ * @name: returns pointer to NAME string
+ * @value: returns pointer to VALUE string
+ *
+ * "TAG" is NAME=VALUE (e.g. LABEL=foo)
+ *
+ * The TAG is the first column in the fstab file. The TAG or "srcpath" always has
+ * to be set for all entries.
+ *
+ * See also mnt_fs_get_source().
+ *
+ * <informalexample>
+ *   <programlisting>
+ *	char *src;
+ *	struct libmnt_fs *fs = mnt_table_find_target(tb, "/home", MNT_ITER_FORWARD);
+ *
+ *	if (!fs)
+ *		goto err;
+ *
+ *	src = mnt_fs_get_srcpath(fs);
+ *	if (!src) {
+ *		char *tag, *val;
+ *		if (mnt_fs_get_tag(fs, &tag, &val) == 0)
+ *			printf("%s: %s\n", tag, val);	// LABEL or UUID
+ *	} else
+ *		printf("device: %s\n", src);		// device or bind path
+ *   </programlisting>
+ * </informalexample>
+ *
+ * Returns: 0 on success or negative number in case a TAG is not defined.
+ */
+int mnt_fs_get_tag(struct libmnt_fs *fs, const char **name, const char **value)
+{
+	if (fs == NULL || !fs->tagname)
+		return -EINVAL;
+	if (name)
+		*name = fs->tagname;
+	if (value)
+		*value = fs->tagval;
+	return 0;
+}
+
+/**
+ * mnt_fs_get_target:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: pointer to mountpoint path or NULL
+ */
+const char *mnt_fs_get_target(struct libmnt_fs *fs)
+{
+	return fs ? fs->target : NULL;
+}
+
+/**
+ * mnt_fs_set_target:
+ * @fs: fstab/mtab/mountinfo entry
+ * @tgt: mountpoint
+ *
+ * This function creates a private copy (strdup()) of @tgt.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_target(struct libmnt_fs *fs, const char *tgt)
+{
+	return strdup_to_struct_member(fs, target, tgt);
+}
+
+static int mnt_fs_get_flags(struct libmnt_fs *fs)
+{
+	return fs ? fs->flags : 0;
+}
+
+/**
+ * mnt_fs_get_propagation:
+ * @fs: mountinfo entry
+ * @flags: returns propagation MS_* flags as present in the mountinfo file
+ *
+ * Note that this function sets @flags to zero if no propagation flags are found
+ * in the mountinfo file. The kernel default is MS_PRIVATE, this flag is not stored
+ * in the mountinfo file.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_get_propagation(struct libmnt_fs *fs, unsigned long *flags)
+{
+	if (!fs || !flags)
+		return -EINVAL;
+
+	*flags = 0;
+
+	if (!fs->opt_fields)
+		return 0;
+
+	 /*
+	 * The optional fields format is incompatible with mount options
+	 * ... we have to parse the field here.
+	 */
+	*flags |= strstr(fs->opt_fields, "shared:") ? MS_SHARED : MS_PRIVATE;
+
+	if (strstr(fs->opt_fields, "master:"))
+		*flags |= MS_SLAVE;
+	if (strstr(fs->opt_fields, "unbindable"))
+		*flags |= MS_UNBINDABLE;
+
+	return 0;
+}
+
+/**
+ * mnt_fs_is_kernel:
+ * @fs: filesystem
+ *
+ * Returns: 1 if the filesystem description is read from kernel e.g. /proc/mounts.
+ */
+int mnt_fs_is_kernel(struct libmnt_fs *fs)
+{
+	return mnt_fs_get_flags(fs) & MNT_FS_KERNEL;
+}
+
+/**
+ * mnt_fs_is_swaparea:
+ * @fs: filesystem
+ *
+ * Returns: 1 if the filesystem uses "swap" as a type
+ */
+int mnt_fs_is_swaparea(struct libmnt_fs *fs)
+{
+	return mnt_fs_get_flags(fs) & MNT_FS_SWAP;
+}
+
+/**
+ * mnt_fs_is_pseudofs:
+ * @fs: filesystem
+ *
+ * Returns: 1 if the filesystem is a pseudo fs type (proc, cgroups)
+ */
+int mnt_fs_is_pseudofs(struct libmnt_fs *fs)
+{
+	return mnt_fs_get_flags(fs) & MNT_FS_PSEUDO;
+}
+
+/**
+ * mnt_fs_is_netfs:
+ * @fs: filesystem
+ *
+ * Returns: 1 if the filesystem is a network filesystem
+ */
+int mnt_fs_is_netfs(struct libmnt_fs *fs)
+{
+	return mnt_fs_get_flags(fs) & MNT_FS_NET;
+}
+
+/**
+ * mnt_fs_get_fstype:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: pointer to filesystem type.
+ */
+const char *mnt_fs_get_fstype(struct libmnt_fs *fs)
+{
+	return fs ? fs->fstype : NULL;
+}
+
+/* Used by the struct libmnt_file parser only */
+int __mnt_fs_set_fstype_ptr(struct libmnt_fs *fs, char *fstype)
+{
+	assert(fs);
+
+	if (fstype != fs->fstype)
+		free(fs->fstype);
+
+	fs->fstype = fstype;
+	fs->flags &= ~MNT_FS_PSEUDO;
+	fs->flags &= ~MNT_FS_NET;
+	fs->flags &= ~MNT_FS_SWAP;
+
+	/* save info about pseudo filesystems */
+	if (fs->fstype) {
+		if (mnt_fstype_is_pseudofs(fs->fstype))
+			fs->flags |= MNT_FS_PSEUDO;
+		else if (mnt_fstype_is_netfs(fs->fstype))
+			fs->flags |= MNT_FS_NET;
+		else if (!strcmp(fs->fstype, "swap"))
+			fs->flags |= MNT_FS_SWAP;
+	}
+	return 0;
+}
+
+/**
+ * mnt_fs_set_fstype:
+ * @fs: fstab/mtab/mountinfo entry
+ * @fstype: filesystem type
+ *
+ * This function creates a private copy (strdup()) of @fstype.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_fstype(struct libmnt_fs *fs, const char *fstype)
+{
+	char *p = NULL;
+
+	if (!fs)
+		return -EINVAL;
+	if (fstype) {
+		p = strdup(fstype);
+		if (!p)
+			return -ENOMEM;
+	}
+	return  __mnt_fs_set_fstype_ptr(fs, p);
+}
+
+/*
+ * Merges @vfs and @fs options strings into a new string.
+ * This function cares about 'ro/rw' options. The 'ro' is
+ * always used if @vfs or @fs is read-only.
+ * For example:
+ *
+ *    mnt_merge_optstr("rw,noexec", "ro,journal=update")
+ *
+ *           returns: "ro,noexec,journal=update"
+ *
+ *    mnt_merge_optstr("rw,noexec", "rw,journal=update")
+ *
+ *           returns: "rw,noexec,journal=update"
+ */
+static char *merge_optstr(const char *vfs, const char *fs)
+{
+	char *res, *p;
+	size_t sz;
+	int ro = 0, rw = 0;
+
+	if (!vfs && !fs)
+		return NULL;
+	if (!vfs || !fs)
+		return strdup(fs ? fs : vfs);
+	if (!strcmp(vfs, fs))
+		return strdup(vfs);		/* e.g. "aaa" and "aaa" */
+
+	/* leave space for the leading "r[ow],", "," and the trailing zero */
+	sz = strlen(vfs) + strlen(fs) + 5;
+	res = malloc(sz);
+	if (!res)
+		return NULL;
+	p = res + 3;			/* make a room for rw/ro flag */
+
+	snprintf(p, sz - 3, "%s,%s", vfs, fs);
+
+	/* remove 'rw' flags */
+	rw += !mnt_optstr_remove_option(&p, "rw");	/* from vfs */
+	rw += !mnt_optstr_remove_option(&p, "rw");	/* from fs */
+
+	/* remove 'ro' flags if necessary */
+	if (rw != 2) {
+		ro += !mnt_optstr_remove_option(&p, "ro");
+		if (ro + rw < 2)
+			ro += !mnt_optstr_remove_option(&p, "ro");
+	}
+
+	if (!strlen(p))
+		memcpy(res, ro ? "ro" : "rw", 3);
+	else
+		memcpy(res, ro ? "ro," : "rw,", 3);
+	return res;
+}
+
+/**
+ * mnt_fs_strdup_options:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Merges all mount options (VFS, FS and userspace) to one options string
+ * and returns the result. This function does not modify @fs.
+ *
+ * Returns: pointer to string (can be freed by free(3)) or NULL in case of error.
+ */
+char *mnt_fs_strdup_options(struct libmnt_fs *fs)
+{
+	char *res;
+
+	if (!fs)
+		return NULL;
+
+	errno = 0;
+	if (fs->optstr)
+		return strdup(fs->optstr);
+
+	res = merge_optstr(fs->vfs_optstr, fs->fs_optstr);
+	if (!res && errno)
+		return NULL;
+	if (fs->user_optstr &&
+	    mnt_optstr_append_option(&res, fs->user_optstr, NULL)) {
+		free(res);
+		res = NULL;
+	}
+	return res;
+}
+
+/**
+ * mnt_fs_get_options:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: pointer to string or NULL in case of error.
+ */
+const char *mnt_fs_get_options(struct libmnt_fs *fs)
+{
+	return fs ? fs->optstr : NULL;
+}
+
+/**
+ * mnt_fs_get_optional_fields
+ * @fs: mountinfo entry pointer
+ *
+ * Returns: pointer to string with mountinfo optional fields
+ *          or NULL in case of error.
+ */
+const char *mnt_fs_get_optional_fields(struct libmnt_fs *fs)
+{
+	return fs ? fs->opt_fields : NULL;
+}
+
+/**
+ * mnt_fs_set_options:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ * @optstr: options string
+ *
+ * Splits @optstr to VFS, FS and userspace mount options and updates relevant
+ * parts of @fs.
+ *
+ * Returns: 0 on success, or negative number in case of error.
+ */
+int mnt_fs_set_options(struct libmnt_fs *fs, const char *optstr)
+{
+	char *v = NULL, *f = NULL, *u = NULL, *n = NULL;
+
+	if (!fs)
+		return -EINVAL;
+	if (optstr) {
+		int rc = mnt_split_optstr(optstr, &u, &v, &f, 0, 0);
+		if (rc)
+			return rc;
+		n = strdup(optstr);
+		if (!n) {
+			free(u);
+			free(v);
+			free(f);
+			return -ENOMEM;
+		}
+	}
+
+	free(fs->fs_optstr);
+	free(fs->vfs_optstr);
+	free(fs->user_optstr);
+	free(fs->optstr);
+
+	fs->fs_optstr = f;
+	fs->vfs_optstr = v;
+	fs->user_optstr = u;
+	fs->optstr = n;
+
+	return 0;
+}
+
+/**
+ * mnt_fs_append_options:
+ * @fs: fstab/mtab/mountinfo entry
+ * @optstr: mount options
+ *
+ * Parses (splits) @optstr and appends results to VFS, FS and userspace lists
+ * of options.
+ *
+ * If @optstr is NULL, then @fs is not modified and 0 is returned.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_append_options(struct libmnt_fs *fs, const char *optstr)
+{
+	char *v = NULL, *f = NULL, *u = NULL;
+	int rc;
+
+	if (!fs)
+		return -EINVAL;
+	if (!optstr)
+		return 0;
+
+	rc = mnt_split_optstr(optstr, &u, &v, &f, 0, 0);
+	if (rc)
+		return rc;
+
+	if (!rc && v)
+		rc = mnt_optstr_append_option(&fs->vfs_optstr, v, NULL);
+	if (!rc && f)
+		rc = mnt_optstr_append_option(&fs->fs_optstr, f, NULL);
+	if (!rc && u)
+		rc = mnt_optstr_append_option(&fs->user_optstr, u, NULL);
+	if (!rc)
+		rc = mnt_optstr_append_option(&fs->optstr, optstr, NULL);
+
+	free(v);
+	free(f);
+	free(u);
+
+	return rc;
+}
+
+/**
+ * mnt_fs_prepend_options:
+ * @fs: fstab/mtab/mountinfo entry
+ * @optstr: mount options
+ *
+ * Parses (splits) @optstr and prepends the results to VFS, FS and userspace lists
+ * of options.
+ *
+ * If @optstr is NULL, then @fs is not modified and 0 is returned.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_prepend_options(struct libmnt_fs *fs, const char *optstr)
+{
+	char *v = NULL, *f = NULL, *u = NULL;
+	int rc;
+
+	if (!fs)
+		return -EINVAL;
+	if (!optstr)
+		return 0;
+
+	rc = mnt_split_optstr(optstr, &u, &v, &f, 0, 0);
+	if (rc)
+		return rc;
+
+	if (!rc && v)
+		rc = mnt_optstr_prepend_option(&fs->vfs_optstr, v, NULL);
+	if (!rc && f)
+		rc = mnt_optstr_prepend_option(&fs->fs_optstr, f, NULL);
+	if (!rc && u)
+		rc = mnt_optstr_prepend_option(&fs->user_optstr, u, NULL);
+	if (!rc)
+		rc = mnt_optstr_prepend_option(&fs->optstr, optstr, NULL);
+
+	free(v);
+	free(f);
+	free(u);
+
+	return rc;
+}
+
+/*
+ * mnt_fs_get_fs_options:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: pointer to superblock (fs-depend) mount option string or NULL.
+ */
+const char *mnt_fs_get_fs_options(struct libmnt_fs *fs)
+{
+	return fs ? fs->fs_optstr : NULL;
+}
+
+/**
+ * mnt_fs_get_vfs_options:
+ * @fs: fstab/mtab entry pointer
+ *
+ * Returns: pointer to fs-independent (VFS) mount option string or NULL.
+ */
+const char *mnt_fs_get_vfs_options(struct libmnt_fs *fs)
+{
+	return fs ? fs->vfs_optstr : NULL;
+}
+
+/**
+ * mnt_fs_get_user_options:
+ * @fs: fstab/mtab entry pointer
+ *
+ * Returns: pointer to userspace mount option string or NULL.
+ */
+const char *mnt_fs_get_user_options(struct libmnt_fs *fs)
+{
+	return fs ? fs->user_optstr : NULL;
+}
+
+/**
+ * mnt_fs_get_attributes:
+ * @fs: fstab/mtab entry pointer
+ *
+ * Returns: pointer to attributes string or NULL.
+ */
+const char *mnt_fs_get_attributes(struct libmnt_fs *fs)
+{
+	return fs ? fs->attrs : NULL;
+}
+
+/**
+ * mnt_fs_set_attributes:
+ * @fs: fstab/mtab/mountinfo entry
+ * @optstr: options string
+ *
+ * Sets mount attributes. The attributes are mount(2) and mount(8) independent
+ * options, these options are not sent to the kernel and are not interpreted by
+ * libmount. The attributes are stored in /run/mount/utab only.
+ *
+ * The attributes are managed by libmount in userspace only. It's possible
+ * that information stored in userspace will not be available for libmount
+ * after CLONE_FS unshare. Be careful, and don't use attributes if possible.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_attributes(struct libmnt_fs *fs, const char *optstr)
+{
+	return strdup_to_struct_member(fs, attrs, optstr);
+}
+
+/**
+ * mnt_fs_append_attributes
+ * @fs: fstab/mtab/mountinfo entry
+ * @optstr: options string
+ *
+ * Appends mount attributes. (See mnt_fs_set_attributes()).
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_append_attributes(struct libmnt_fs *fs, const char *optstr)
+{
+	if (!fs)
+		return -EINVAL;
+	if (!optstr)
+		return 0;
+	return mnt_optstr_append_option(&fs->attrs, optstr, NULL);
+}
+
+/**
+ * mnt_fs_prepend_attributes
+ * @fs: fstab/mtab/mountinfo entry
+ * @optstr: options string
+ *
+ * Prepends mount attributes. (See mnt_fs_set_attributes()).
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_prepend_attributes(struct libmnt_fs *fs, const char *optstr)
+{
+	if (!fs)
+		return -EINVAL;
+	if (!optstr)
+		return 0;
+	return mnt_optstr_prepend_option(&fs->attrs, optstr, NULL);
+}
+
+
+/**
+ * mnt_fs_get_freq:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: dump frequency in days.
+ */
+int mnt_fs_get_freq(struct libmnt_fs *fs)
+{
+	return fs ? fs->freq : 0;
+}
+
+/**
+ * mnt_fs_set_freq:
+ * @fs: fstab/mtab entry pointer
+ * @freq: dump frequency in days
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_freq(struct libmnt_fs *fs, int freq)
+{
+	if (!fs)
+		return -EINVAL;
+	fs->freq = freq;
+	return 0;
+}
+
+/**
+ * mnt_fs_get_passno:
+ * @fs: fstab/mtab entry pointer
+ *
+ * Returns: "pass number on parallel fsck".
+ */
+int mnt_fs_get_passno(struct libmnt_fs *fs)
+{
+	return fs ? fs->passno: 0;
+}
+
+/**
+ * mnt_fs_set_passno:
+ * @fs: fstab/mtab entry pointer
+ * @passno: pass number
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_passno(struct libmnt_fs *fs, int passno)
+{
+	if (!fs)
+		return -EINVAL;
+	fs->passno = passno;
+	return 0;
+}
+
+/**
+ * mnt_fs_get_root:
+ * @fs: /proc/self/mountinfo entry
+ *
+ * Returns: root of the mount within the filesystem or NULL
+ */
+const char *mnt_fs_get_root(struct libmnt_fs *fs)
+{
+	return fs ? fs->root : NULL;
+}
+
+/**
+ * mnt_fs_set_root:
+ * @fs: mountinfo entry
+ * @path: root path
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_root(struct libmnt_fs *fs, const char *path)
+{
+	return strdup_to_struct_member(fs, root, path);
+}
+
+/**
+ * mnt_fs_get_swaptype:
+ * @fs: /proc/swaps entry
+ *
+ * Returns: swap type or NULL
+ */
+const char *mnt_fs_get_swaptype(struct libmnt_fs *fs)
+{
+	return fs ? fs->swaptype : NULL;
+}
+
+/**
+ * mnt_fs_get_size:
+ * @fs: /proc/swaps entry
+ *
+ * Returns: size
+ */
+off_t mnt_fs_get_size(struct libmnt_fs *fs)
+{
+	return fs ? fs->size : 0;
+}
+
+/**
+ * mnt_fs_get_usedsize:
+ * @fs: /proc/swaps entry
+ *
+ * Returns: used size
+ */
+off_t mnt_fs_get_usedsize(struct libmnt_fs *fs)
+{
+	return fs ? fs->usedsize : 0;
+}
+
+/**
+ * mnt_fs_get_priority:
+ * @fs: /proc/swaps entry
+ *
+ * Returns: priority
+ */
+int mnt_fs_get_priority(struct libmnt_fs *fs)
+{
+	return fs ? fs->priority : 0;
+}
+
+/**
+ * mnt_fs_set_priority:
+ * @fs: /proc/swaps entry
+ * @prio: priority
+ *
+ * Since: 2.28
+ *
+ * Returns: 0 or -1 in case of error
+ */
+int mnt_fs_set_priority(struct libmnt_fs *fs, int prio)
+{
+	if (!fs)
+		return -EINVAL;
+	fs->priority = prio;
+	return 0;
+}
+
+/**
+ * mnt_fs_get_bindsrc:
+ * @fs: /run/mount/utab entry
+ *
+ * Returns: full path that was used for mount(2) on MS_BIND
+ */
+const char *mnt_fs_get_bindsrc(struct libmnt_fs *fs)
+{
+	return fs ? fs->bindsrc : NULL;
+}
+
+/**
+ * mnt_fs_set_bindsrc:
+ * @fs: filesystem
+ * @src: path
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_set_bindsrc(struct libmnt_fs *fs, const char *src)
+{
+	return strdup_to_struct_member(fs, bindsrc, src);
+}
+
+/**
+ * mnt_fs_get_id:
+ * @fs: /proc/self/mountinfo entry
+ *
+ * Returns: mount ID (unique identifier of the mount) or negative number in case of error.
+ */
+int mnt_fs_get_id(struct libmnt_fs *fs)
+{
+	return fs ? fs->id : -EINVAL;
+}
+
+/**
+ * mnt_fs_get_parent_id:
+ * @fs: /proc/self/mountinfo entry
+ *
+ * Returns: parent mount ID or negative number in case of error.
+ */
+int mnt_fs_get_parent_id(struct libmnt_fs *fs)
+{
+	return fs ? fs->parent : -EINVAL;
+}
+
+/**
+ * mnt_fs_get_devno:
+ * @fs: /proc/self/mountinfo entry
+ *
+ * Returns: value of st_dev for files on filesystem or 0 in case of error.
+ */
+dev_t mnt_fs_get_devno(struct libmnt_fs *fs)
+{
+	return fs ? fs->devno : 0;
+}
+
+/**
+ * mnt_fs_get_tid:
+ * @fs: /proc/tid/mountinfo entry
+ *
+ * Returns: TID (task ID) for filesystems read from the mountinfo file
+ */
+pid_t mnt_fs_get_tid(struct libmnt_fs *fs)
+{
+	return fs ? fs->tid : 0;
+}
+
+/**
+ * mnt_fs_get_option:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ * @name: option name
+ * @value: returns pointer to the beginning of the value (e.g. name=VALUE) or NULL
+ * @valsz: returns size of options value or 0
+ *
+ * Returns: 0 on success, 1 when @name not found or negative number in case of error.
+ */
+int mnt_fs_get_option(struct libmnt_fs *fs, const char *name,
+		char **value, size_t *valsz)
+{
+	char rc = 1;
+
+	if (!fs)
+		return -EINVAL;
+	if (fs->fs_optstr)
+		rc = mnt_optstr_get_option(fs->fs_optstr, name, value, valsz);
+	if (rc == 1 && fs->vfs_optstr)
+		rc = mnt_optstr_get_option(fs->vfs_optstr, name, value, valsz);
+	if (rc == 1 && fs->user_optstr)
+		rc = mnt_optstr_get_option(fs->user_optstr, name, value, valsz);
+	return rc;
+}
+
+/**
+ * mnt_fs_get_attribute:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ * @name: option name
+ * @value: returns pointer to the beginning of the value (e.g. name=VALUE) or NULL
+ * @valsz: returns size of options value or 0
+ *
+ * Returns: 0 on success, 1 when @name not found or negative number in case of error.
+ */
+int mnt_fs_get_attribute(struct libmnt_fs *fs, const char *name,
+		char **value, size_t *valsz)
+{
+	char rc = 1;
+
+	if (!fs)
+		return -EINVAL;
+	if (fs->attrs)
+		rc = mnt_optstr_get_option(fs->attrs, name, value, valsz);
+	return rc;
+}
+
+/**
+ * mnt_fs_get_comment:
+ * @fs: fstab/mtab/mountinfo entry pointer
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case of error.
+ */
+const char *mnt_fs_get_comment(struct libmnt_fs *fs)
+{
+	if (!fs)
+		return NULL;
+	return fs->comment;
+}
+
+/**
+ * mnt_fs_set_comment:
+ * @fs: fstab entry pointer
+ * @comm: comment string
+ *
+ * Note that the comment has to be terminated by '\n' (new line), otherwise
+ * the whole filesystem entry will be written as a comment to the tabfile (e.g.
+ * fstab).
+ *
+ * Returns: 0 on success or <0 in case of error.
+ */
+int mnt_fs_set_comment(struct libmnt_fs *fs, const char *comm)
+{
+	return strdup_to_struct_member(fs, comment, comm);
+}
+
+/**
+ * mnt_fs_append_comment:
+ * @fs: fstab entry pointer
+ * @comm: comment string
+ *
+ * See also mnt_fs_set_comment().
+ *
+ * Returns: 0 on success or <0 in case of error.
+ */
+int mnt_fs_append_comment(struct libmnt_fs *fs, const char *comm)
+{
+	if (!fs)
+		return -EINVAL;
+
+	return append_string(&fs->comment, comm);
+}
+
+/**
+ * mnt_fs_match_target:
+ * @fs: filesystem
+ * @target: mountpoint path
+ * @cache: tags/paths cache or NULL
+ *
+ * Possible are three attempts:
+ *	1) compare @target with @fs->target
+ *
+ *	2) realpath(@target) with @fs->target
+ *
+ *	3) realpath(@target) with realpath(@fs->target) if @fs is not from
+ *	   /proc/self/mountinfo.
+ *
+ *	   However, if mnt_cache_set_targets(cache, mtab) was called, and the
+ *	   path @target or @fs->target is found in the @mtab, the canonicalization is
+ *	   is not performed (see mnt_resolve_target()).
+ *
+ * The 2nd and 3rd attempts are not performed when @cache is NULL.
+ *
+ * Returns: 1 if @fs target is equal to @target, else 0.
+ */
+int mnt_fs_match_target(struct libmnt_fs *fs, const char *target,
+			struct libmnt_cache *cache)
+{
+	int rc = 0;
+
+	if (!fs || !target || !fs->target)
+		return 0;
+
+	/* 1) native paths */
+	rc = mnt_fs_streq_target(fs, target);
+
+	if (!rc && cache) {
+		/* 2) - canonicalized and non-canonicalized */
+		char *cn = mnt_resolve_target(target, cache);
+		rc = (cn && mnt_fs_streq_target(fs, cn));
+
+		/* 3) - canonicalized and canonicalized */
+		if (!rc && cn && !mnt_fs_is_kernel(fs) && !mnt_fs_is_swaparea(fs)) {
+			char *tcn = mnt_resolve_target(fs->target, cache);
+			rc = (tcn && strcmp(cn, tcn) == 0);
+		}
+	}
+
+	return rc;
+}
+
+/**
+ * mnt_fs_match_source:
+ * @fs: filesystem
+ * @source: tag or path (device or so) or NULL
+ * @cache: tags/paths cache or NULL
+ *
+ * Four attempts are possible:
+ *	1) compare @source with @fs->source
+ *	2) compare realpath(@source) with @fs->source
+ *	3) compare realpath(@source) with realpath(@fs->source)
+ *	4) compare realpath(@source) with evaluated tag from @fs->source
+ *
+ * The 2nd, 3rd and 4th attempts are not performed when @cache is NULL. The
+ * 2nd and 3rd attempts are not performed if @fs->source is tag.
+ *
+ * Returns: 1 if @fs source is equal to @source, else 0.
+ */
+int mnt_fs_match_source(struct libmnt_fs *fs, const char *source,
+			struct libmnt_cache *cache)
+{
+	char *cn;
+	const char *src, *t, *v;
+
+	if (!fs)
+		return 0;
+
+	/* 1) native paths... */
+	if (mnt_fs_streq_srcpath(fs, source) == 1)
+		return 1;
+
+	if (!source || !fs->source)
+		return 0;
+
+	/* ... and tags */
+	if (fs->tagname && strcmp(source, fs->source) == 0)
+		return 1;
+
+	if (!cache)
+		return 0;
+	if (fs->flags & (MNT_FS_NET | MNT_FS_PSEUDO))
+		return 0;
+
+	cn = mnt_resolve_spec(source, cache);
+	if (!cn)
+		return 0;
+
+	/* 2) canonicalized and native */
+	src = mnt_fs_get_srcpath(fs);
+	if (src && mnt_fs_streq_srcpath(fs, cn))
+		return 1;
+
+	/* 3) canonicalized and canonicalized */
+	if (src) {
+		src = mnt_resolve_path(src, cache);
+		if (src && !strcmp(cn, src))
+			return 1;
+	}
+	if (src || mnt_fs_get_tag(fs, &t, &v))
+		/* src path does not match and the tag is not defined */
+		return 0;
+
+	/* read @source's tags to the cache */
+	if (mnt_cache_read_tags(cache, cn) < 0) {
+		if (errno == EACCES) {
+			/* we don't have permissions to read TAGs from
+			 * @source, but can translate the @fs tag to devname.
+			 *
+			 * (because libblkid uses udev symlinks and this is
+			 * accessible for non-root uses)
+			 */
+			char *x = mnt_resolve_tag(t, v, cache);
+			if (x && !strcmp(x, cn))
+				return 1;
+		}
+		return 0;
+	}
+
+	/* 4) has the @source a tag that matches with the tag from @fs ? */
+	if (mnt_cache_device_has_tag(cache, cn, t, v))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * mnt_fs_match_fstype:
+ * @fs: filesystem
+ * @types: filesystem name or comma delimited list of filesystems
+ *
+ * For more details see mnt_match_fstype().
+ *
+ * Returns: 1 if @fs type is matching to @types, else 0. The function returns
+ * 0 when types is NULL.
+ */
+int mnt_fs_match_fstype(struct libmnt_fs *fs, const char *types)
+{
+	return mnt_match_fstype(fs->fstype, types);
+}
+
+/**
+ * mnt_fs_match_options:
+ * @fs: filesystem
+ * @options: comma delimited list of options (and nooptions)
+ *
+ * For more details see mnt_match_options().
+ *
+ * Returns: 1 if @fs type is matching to @options, else 0. The function returns
+ * 0 when types is NULL.
+ */
+int mnt_fs_match_options(struct libmnt_fs *fs, const char *options)
+{
+	return mnt_match_options(mnt_fs_get_options(fs), options);
+}
+
+/**
+ * mnt_fs_print_debug
+ * @fs: fstab/mtab/mountinfo entry
+ * @file: file stream
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_print_debug(struct libmnt_fs *fs, FILE *file)
+{
+	if (!fs || !file)
+		return -EINVAL;
+	fprintf(file, "------ fs:\n");
+	fprintf(file, "source: %s\n", mnt_fs_get_source(fs));
+	fprintf(file, "target: %s\n", mnt_fs_get_target(fs));
+	fprintf(file, "fstype: %s\n", mnt_fs_get_fstype(fs));
+
+	if (mnt_fs_get_options(fs))
+		fprintf(file, "optstr: %s\n", mnt_fs_get_options(fs));
+	if (mnt_fs_get_vfs_options(fs))
+		fprintf(file, "VFS-optstr: %s\n", mnt_fs_get_vfs_options(fs));
+	if (mnt_fs_get_fs_options(fs))
+		fprintf(file, "FS-opstr: %s\n", mnt_fs_get_fs_options(fs));
+	if (mnt_fs_get_user_options(fs))
+		fprintf(file, "user-optstr: %s\n", mnt_fs_get_user_options(fs));
+	if (mnt_fs_get_optional_fields(fs))
+		fprintf(file, "optional-fields: '%s'\n", mnt_fs_get_optional_fields(fs));
+	if (mnt_fs_get_attributes(fs))
+		fprintf(file, "attributes: %s\n", mnt_fs_get_attributes(fs));
+
+	if (mnt_fs_get_root(fs))
+		fprintf(file, "root:   %s\n", mnt_fs_get_root(fs));
+
+	if (mnt_fs_get_swaptype(fs))
+		fprintf(file, "swaptype: %s\n", mnt_fs_get_swaptype(fs));
+	if (mnt_fs_get_size(fs))
+		fprintf(file, "size: %jd\n", mnt_fs_get_size(fs));
+	if (mnt_fs_get_usedsize(fs))
+		fprintf(file, "usedsize: %jd\n", mnt_fs_get_usedsize(fs));
+	if (mnt_fs_get_priority(fs))
+		fprintf(file, "priority: %d\n", mnt_fs_get_priority(fs));
+
+	if (mnt_fs_get_bindsrc(fs))
+		fprintf(file, "bindsrc: %s\n", mnt_fs_get_bindsrc(fs));
+	if (mnt_fs_get_freq(fs))
+		fprintf(file, "freq:   %d\n", mnt_fs_get_freq(fs));
+	if (mnt_fs_get_passno(fs))
+		fprintf(file, "pass:   %d\n", mnt_fs_get_passno(fs));
+	if (mnt_fs_get_id(fs))
+		fprintf(file, "id:     %d\n", mnt_fs_get_id(fs));
+	if (mnt_fs_get_parent_id(fs))
+		fprintf(file, "parent: %d\n", mnt_fs_get_parent_id(fs));
+	if (mnt_fs_get_devno(fs))
+		fprintf(file, "devno:  %d:%d\n", major(mnt_fs_get_devno(fs)),
+						minor(mnt_fs_get_devno(fs)));
+	if (mnt_fs_get_tid(fs))
+		fprintf(file, "tid:    %d\n", mnt_fs_get_tid(fs));
+	if (mnt_fs_get_comment(fs))
+		fprintf(file, "comment: '%s'\n", mnt_fs_get_comment(fs));
+
+	return 0;
+}
+
+/**
+ * mnt_free_mntent:
+ * @mnt: mount entry
+ *
+ * Deallocates the "mntent.h" mount entry.
+ */
+void mnt_free_mntent(struct mntent *mnt)
+{
+	if (mnt) {
+		free(mnt->mnt_fsname);
+		free(mnt->mnt_dir);
+		free(mnt->mnt_type);
+		free(mnt->mnt_opts);
+		free(mnt);
+	}
+}
+
+/**
+ * mnt_fs_to_mntent:
+ * @fs: filesystem
+ * @mnt: mount description (as described in mntent.h)
+ *
+ * Copies the information from @fs to struct mntent @mnt. If @mnt is already set,
+ * then the struct mntent items are reallocated and updated. See also
+ * mnt_free_mntent().
+ *
+ * Returns: 0 on success and a negative number in case of error.
+ */
+int mnt_fs_to_mntent(struct libmnt_fs *fs, struct mntent **mnt)
+{
+	int rc;
+	struct mntent *m;
+
+	if (!fs || !mnt)
+		return -EINVAL;
+
+	m = *mnt;
+	if (!m) {
+		m = calloc(1, sizeof(*m));
+		if (!m)
+			return -ENOMEM;
+	}
+
+	if ((rc = update_str(&m->mnt_fsname, mnt_fs_get_source(fs))))
+		goto err;
+	if ((rc = update_str(&m->mnt_dir, mnt_fs_get_target(fs))))
+		goto err;
+	if ((rc = update_str(&m->mnt_type, mnt_fs_get_fstype(fs))))
+		goto err;
+
+	errno = 0;
+	m->mnt_opts = mnt_fs_strdup_options(fs);
+	if (!m->mnt_opts && errno) {
+		rc = -errno;
+		goto err;
+	}
+
+	m->mnt_freq = mnt_fs_get_freq(fs);
+	m->mnt_passno = mnt_fs_get_passno(fs);
+
+	if (!m->mnt_fsname) {
+		m->mnt_fsname = strdup("none");
+		if (!m->mnt_fsname)
+			goto err;
+	}
+	*mnt = m;
+
+	return 0;
+err:
+	if (m != *mnt)
+		mnt_free_mntent(m);
+	return rc;
+}
diff --git a/libmount/src/init.c b/libmount/src/init.c
new file mode 100644
index 0000000..2410fcc
--- /dev/null
+++ b/libmount/src/init.c
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: init
+ * @title: Library initialization
+ * @short_description: initialize debugging
+ */
+
+#include <stdarg.h>
+
+#include "mountP.h"
+
+UL_DEBUG_DEFINE_MASK(libmount);
+UL_DEBUG_DEFINE_MASKNAMES(libmount) =
+{
+	{ "all", MNT_DEBUG_ALL,		"info about all subsystems" },
+	{ "cache", MNT_DEBUG_CACHE,	"paths and tags cache" },
+	{ "cxt", MNT_DEBUG_CXT,		"library context (handler)" },
+	{ "diff", MNT_DEBUG_DIFF,	"mountinfo changes tracking" },
+	{ "fs", MNT_DEBUG_FS,		"FS abstraction" },
+	{ "help", MNT_DEBUG_HELP,	"this help" },
+	{ "locks", MNT_DEBUG_LOCKS,	"mtab and utab locking" },
+	{ "loop", MNT_DEBUG_LOOP,	"loop devices routines" },
+	{ "options", MNT_DEBUG_OPTIONS,	"mount options parsing" },
+	{ "tab", MNT_DEBUG_TAB,		"fstab, mtab, mountinfo routines" },
+	{ "update", MNT_DEBUG_UPDATE,	"mtab, utab updates" },
+	{ "utils", MNT_DEBUG_UTILS,	"misc library utils" },
+	{ "monitor", MNT_DEBUG_MONITOR,	"mount tables monitor" },
+	{ "btrfs", MNT_DEBUG_BTRFS,	"btrfs specific routines" },
+	{ "verity", MNT_DEBUG_VERITY,	"verity specific routines" },
+
+	{ NULL, 0 }
+};
+
+/**
+ * mnt_init_debug:
+ * @mask: debug mask (0xffff to enable full debugging)
+ *
+ * If the @mask is not specified, then this function reads
+ * the LIBMOUNT_DEBUG environment variable to get the mask.
+ *
+ * Already initialized debugging stuff cannot be changed. Calling
+ * this function twice has no effect.
+ */
+void mnt_init_debug(int mask)
+{
+	if (libmount_debug_mask)
+		return;
+
+	__UL_INIT_DEBUG_FROM_ENV(libmount, MNT_DEBUG_, mask, LIBMOUNT_DEBUG);
+
+	if (libmount_debug_mask != MNT_DEBUG_INIT
+	    && libmount_debug_mask != (MNT_DEBUG_HELP|MNT_DEBUG_INIT)) {
+		const char *ver = NULL;
+		const char **features = NULL, **p;
+
+		mnt_get_library_version(&ver);
+		mnt_get_library_features(&features);
+
+		DBG(INIT, ul_debug("library debug mask: 0x%04x", libmount_debug_mask));
+		DBG(INIT, ul_debug("library version: %s", ver));
+		p = features;
+		while (p && *p)
+			DBG(INIT, ul_debug("    feature: %s", *p++));
+	}
+
+	ON_DBG(HELP, ul_debug_print_masks("LIBMOUNT_DEBUG",
+				UL_DEBUG_MASKNAMES(libmount)));
+}
+
+#ifdef TEST_PROGRAM
+
+#include <errno.h>
+#include <stdlib.h>
+int main(int argc, char *argv[])
+{
+	if (argc == 2) {
+		int mask;
+
+		errno = 0;
+		mask = strtoul(argv[1], 0, 0);
+
+		if (errno)
+			return 1;
+
+		mnt_init_debug(mask);
+	}
+	else if (argc == 1) {
+		mnt_init_debug(0);
+	} else
+		return 1;
+
+	return 0;
+}
+#endif /* TEST_PROGRAM */
+
diff --git a/libmount/src/iter.c b/libmount/src/iter.c
new file mode 100644
index 0000000..891e2c8
--- /dev/null
+++ b/libmount/src/iter.c
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: iter
+ * @title: Iterator
+ * @short_description: unified iterator
+ *
+ * The iterator keeps the direction and the last position
+ * for access to the internal library tables/lists.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "mountP.h"
+
+/**
+ * mnt_new_iter:
+ * @direction: MNT_INTER_{FOR,BACK}WARD direction
+ *
+ * Returns: newly allocated generic libmount iterator.
+ */
+struct libmnt_iter *mnt_new_iter(int direction)
+{
+	struct libmnt_iter *itr = calloc(1, sizeof(*itr));
+	if (!itr)
+		return NULL;
+	itr->direction = direction;
+	return itr;
+}
+
+/**
+ * mnt_free_iter:
+ * @itr: iterator pointer
+ *
+ * Deallocates the iterator.
+ */
+void mnt_free_iter(struct libmnt_iter *itr)
+{
+	free(itr);
+}
+
+/**
+ * mnt_reset_iter:
+ * @itr: iterator pointer
+ * @direction: MNT_INTER_{FOR,BACK}WARD or -1 to keep the direction unchanged
+ *
+ * Resets the iterator.
+ */
+void mnt_reset_iter(struct libmnt_iter *itr, int direction)
+{
+	if (direction == -1)
+		direction = itr->direction;
+
+	memset(itr, 0, sizeof(*itr));
+	itr->direction = direction;
+}
+
+/**
+ * mnt_iter_get_direction:
+ * @itr: iterator pointer
+ *
+ * Returns: MNT_INTER_{FOR,BACK}WARD
+ */
+int mnt_iter_get_direction(struct libmnt_iter *itr)
+{
+	return itr->direction;
+}
diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in
new file mode 100644
index 0000000..e6710ae
--- /dev/null
+++ b/libmount/src/libmount.h.in
@@ -0,0 +1,1016 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * libmount.h - libmount API
+ *
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _LIBMOUNT_MOUNT_H
+#define _LIBMOUNT_MOUNT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <mntent.h>
+#include <sys/types.h>
+
+/* Make sure libc MS_* definitions are used by default. Note that MS_* flags
+ * may be already defined by linux/fs.h or another file -- in this case we
+ * don't want to include sys/mount.h at all to avoid collisions.
+ */
+#if defined(__linux__) && !defined(MS_RDONLY)
+# include <sys/mount.h>
+#endif
+
+#define LIBMOUNT_VERSION   "@LIBMOUNT_VERSION@"
+#define LIBMOUNT_MAJOR_VERSION   @LIBMOUNT_MAJOR_VERSION@
+#define LIBMOUNT_MINOR_VERSION   @LIBMOUNT_MINOR_VERSION@
+#define LIBMOUNT_PATCH_VERSION   @LIBMOUNT_PATCH_VERSION@
+
+/**
+ * libmnt_cache:
+ *
+ * Stores canonicalized paths and evaluated tags
+ */
+struct libmnt_cache;
+
+/**
+ * libmnt_lock:
+ *
+ * Stores information about the locked file (e.g. /etc/mtab)
+ */
+struct libmnt_lock;
+
+/**
+ * libmnt_iter:
+ *
+ * Generic iterator (stores state about lists)
+ */
+struct libmnt_iter;
+
+/**
+ * libmnt_optmap:
+ * @name: option name[=type] where type is printf-like type specifier")
+ * @id: option ID or MS_* flags (e.g MS_RDONLY)
+ * @mask: MNT_{NOMTAB,INVERT,...} mask
+ *
+ * Mount options description (map)
+ */
+struct libmnt_optmap
+{
+	const char	*name;
+	int		id;
+	int		mask;
+};
+
+/*
+ * mount options map masks
+ */
+#define MNT_INVERT	(1 << 1) /* invert the mountflag */
+#define MNT_NOMTAB	(1 << 2) /* skip in the mtab option string */
+#define MNT_PREFIX	(1 << 3) /* prefix used for some options (e.g. "x-foo") */
+#define MNT_NOHLPS	(1 << 4) /* don't add the option to mount.<type> helpers command line */
+
+/**
+ * libmnt_fs:
+ *
+ * Parsed fstab/mtab/mountinfo entry
+ */
+struct libmnt_fs;
+
+/**
+ * libmnt_table:
+ *
+ * List of struct libmnt_fs entries (parsed fstab/mtab/mountinfo)
+ */
+struct libmnt_table;
+
+/**
+ * libmnt_update
+ *
+ * /etc/mtab or utab update description
+ */
+struct libmnt_update;
+
+/**
+ * libmnt_context
+ *
+ * Mount/umount status
+ */
+struct libmnt_context;
+
+/**
+ * libmnt_monitor
+ *
+ * Mount tables monitor
+ */
+struct libmnt_monitor;
+
+/**
+ * libmnt_tabdiff:
+ *
+ * Stores mountinfo state
+ */
+struct libmnt_tabdiff;
+
+/**
+ * libmnt_ns:
+ *
+ * Describes mount namespace
+ */
+struct libmnt_ns;
+
+/*
+ * Actions
+ */
+enum {
+	MNT_ACT_MOUNT = 1,
+	MNT_ACT_UMOUNT
+};
+
+/*
+ * Errors -- by default libmount returns -errno for generic errors (ENOMEM,
+ * EINVAL, ...) and for mount(2) errors, but for some specific operations it
+ * returns private error codes. Note that maximum system errno value should be
+ * 4095 on UNIXes.
+ *
+ * See also mnt_context_get_syscall_errno() and mnt_context_get_helper_status().
+ */
+/**
+ * MNT_ERR_NOFSTAB:
+ *
+ * not found required entry in fstab
+ */
+#define MNT_ERR_NOFSTAB      5000
+/**
+ * MNT_ERR_NOFSTYPE:
+ *
+ * failed to detect filesystem type
+ */
+#define MNT_ERR_NOFSTYPE     5001
+/**
+ * MNT_ERR_NOSOURCE:
+ *
+ * required mount source undefined
+ */
+#define MNT_ERR_NOSOURCE     5002
+/**
+ * MNT_ERR_LOOPDEV:
+ *
+ * loopdev setup failed, errno set by libc
+ */
+#define MNT_ERR_LOOPDEV      5003
+/**
+ * MNT_ERR_MOUNTOPT:
+ *
+ * failed to parse/use userspace mount options
+ */
+#define MNT_ERR_MOUNTOPT     5004
+/**
+ * MNT_ERR_APPLYFLAGS:
+ *
+ * failed to apply MS_PROPAGATION flags
+ */
+#define MNT_ERR_APPLYFLAGS   5005
+/**
+ * MNT_ERR_AMBIFS:
+ *
+ * libblkid detected more filesystems on the device
+ */
+#define MNT_ERR_AMBIFS       5006
+/**
+ * MNT_ERR_LOOPOVERLAP:
+ *
+ * detected overlapping loop device that cannot be re-used
+ */
+#define MNT_ERR_LOOPOVERLAP 5007
+/**
+ * MNT_ERR_LOCK:
+ *
+ * failed to lock mtab/utab or so.
+ */
+#define MNT_ERR_LOCK         5008
+/**
+ * MNT_ERR_NAMESPACE:
+ *
+ * failed to switch namespace
+ */
+#define MNT_ERR_NAMESPACE    5009
+
+
+/*
+ * Overall return codes -- based on mount(8) and umount(8) return codes.
+ * See mnt_context_get_excode() for more details.
+ */
+
+/**
+ * MNT_EX_SUCCESS:
+ *
+ * [u]mount(8) exit code: no errors
+ */
+#define MNT_EX_SUCCESS	0
+
+/**
+ * MNT_EX_USAGE:
+ *
+ * [u]mount(8) exit code: incorrect invocation or permission
+ */
+#define MNT_EX_USAGE	1
+
+/**
+ * MNT_EX_SYSERR:
+ *
+ * [u]mount(8) exit code: out of memory, cannot fork, ...
+ */
+
+#define MNT_EX_SYSERR	2
+
+/**
+ * MNT_EX_SOFTWARE:
+ *
+ * [u]mount(8) exit code: internal mount bug or wrong version
+ */
+#define MNT_EX_SOFTWARE	4
+
+/**
+ * MNT_EX_USER:
+ *
+ * [u]mount(8) exit code: user interrupt
+ */
+#define MNT_EX_USER	8
+
+/**
+ * MNT_EX_FILEIO:
+ *
+ * [u]mount(8) exit code: problems writing, locking, ... mtab/utab
+ */
+#define MNT_EX_FILEIO	16
+
+/**
+ * MNT_EX_FAIL:
+ *
+ * [u]mount(8) exit code: mount failure
+ */
+#define MNT_EX_FAIL	32
+
+/**
+ * MNT_EX_SOMEOK:
+ *
+ * [u]mount(8) exit code: some mount succeeded; usually when executed with
+ * --all options. Never returned by libmount.
+ */
+#define MNT_EX_SOMEOK	64
+
+
+
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+#  define __GNUC_PREREQ(maj, min)  ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+# else
+#  define __GNUC_PREREQ(maj, min) 0
+# endif
+#endif
+
+#ifndef __ul_attribute__
+# if __GNUC_PREREQ (3, 4)
+#  define __ul_attribute__(_a_) __attribute__(_a_)
+# else
+#  define __ul_attribute__(_a_)
+# endif
+#endif
+
+
+/* init.c */
+extern void mnt_init_debug(int mask);
+
+/* version.c */
+extern int mnt_parse_version_string(const char *ver_string);
+extern int mnt_get_library_version(const char **ver_string);
+extern int mnt_get_library_features(const char ***features);
+
+/* utils.c */
+extern char *mnt_mangle(const char *str)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_unmangle(const char *str)
+			__ul_attribute__((warn_unused_result));
+
+extern int mnt_tag_is_valid(const char *tag);
+extern int mnt_fstype_is_netfs(const char *type);
+extern int mnt_fstype_is_pseudofs(const char *type);
+
+extern int mnt_match_fstype(const char *type, const char *pattern)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_match_options(const char *optstr, const char *pattern)
+			__ul_attribute__((warn_unused_result));
+extern const char *mnt_get_fstab_path(void);
+extern const char *mnt_get_swaps_path(void);
+extern const char *mnt_get_mtab_path(void);
+extern int mnt_has_regular_mtab(const char **mtab, int *writable);
+extern char *mnt_get_mountpoint(const char *path)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_guess_system_root(dev_t devno, struct libmnt_cache *cache, char **path)
+			__ul_attribute__((nonnull(3)));
+
+/* cache.c */
+extern struct libmnt_cache *mnt_new_cache(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_cache(struct libmnt_cache *cache);
+
+extern void mnt_ref_cache(struct libmnt_cache *cache);
+extern void mnt_unref_cache(struct libmnt_cache *cache);
+
+extern int mnt_cache_set_targets(struct libmnt_cache *cache,
+				struct libmnt_table *mtab);
+extern int mnt_cache_read_tags(struct libmnt_cache *cache, const char *devname);
+
+extern int mnt_cache_device_has_tag(struct libmnt_cache *cache,
+				const char *devname,
+                                const char *token,
+				const char *value);
+
+extern char *mnt_cache_find_tag_value(struct libmnt_cache *cache,
+				const char *devname, const char *token);
+
+extern char *mnt_get_fstype(const char *devname, int *ambi,
+			    struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_resolve_path(const char *path, struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_resolve_target(const char *path, struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_resolve_tag(const char *token, const char *value,
+			     struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_resolve_spec(const char *spec, struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+extern char *mnt_pretty_path(const char *path, struct libmnt_cache *cache)
+			__ul_attribute__((warn_unused_result));
+
+/* optstr.c */
+extern int mnt_optstr_next_option(char **optstr, char **name, size_t *namesz,
+				char **value, size_t *valuesz);
+extern int mnt_optstr_append_option(char **optstr, const char *name,
+				const char *value);
+extern int mnt_optstr_prepend_option(char **optstr, const char *name,
+				const char *value);
+
+extern int mnt_optstr_get_option(const char *optstr, const char *name,
+				char **value, size_t *valsz);
+extern int mnt_optstr_set_option(char **optstr, const char *name,
+				const char *value);
+extern int mnt_optstr_remove_option(char **optstr, const char *name);
+extern int mnt_optstr_deduplicate_option(char **optstr, const char *name);
+
+extern int mnt_split_optstr(const char *optstr,
+			    char **user, char **vfs, char **fs,
+			    int ignore_user, int ignore_vfs);
+
+extern int mnt_optstr_get_options(const char *optstr, char **subset,
+                            const struct libmnt_optmap *map, int ignore);
+
+extern int mnt_optstr_get_flags(const char *optstr, unsigned long *flags,
+				const struct libmnt_optmap *map);
+
+extern int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
+                                const struct libmnt_optmap *map);
+
+/* iter.c */
+enum {
+
+	MNT_ITER_FORWARD = 0,
+	MNT_ITER_BACKWARD
+};
+extern struct libmnt_iter *mnt_new_iter(int direction)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_iter(struct libmnt_iter *itr);
+
+extern void mnt_reset_iter(struct libmnt_iter *itr, int direction)
+			__ul_attribute__((nonnull));
+extern int mnt_iter_get_direction(struct libmnt_iter *itr)
+			__ul_attribute__((nonnull));
+
+/* optmap.c */
+enum {
+	MNT_LINUX_MAP = 1,
+	MNT_USERSPACE_MAP
+};
+extern const struct libmnt_optmap *mnt_get_builtin_optmap(int id);
+
+/* lock.c */
+extern struct libmnt_lock *mnt_new_lock(const char *datafile, pid_t id)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_lock(struct libmnt_lock *ml);
+
+extern void mnt_unlock_file(struct libmnt_lock *ml);
+extern int mnt_lock_file(struct libmnt_lock *ml);
+extern int mnt_lock_block_signals(struct libmnt_lock *ml, int enable);
+
+/* fs.c */
+extern struct libmnt_fs *mnt_new_fs(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_fs(struct libmnt_fs *fs);
+extern void mnt_ref_fs(struct libmnt_fs *fs);
+extern void mnt_unref_fs(struct libmnt_fs *fs);
+
+extern void mnt_reset_fs(struct libmnt_fs *fs);
+extern struct libmnt_fs *mnt_copy_fs(struct libmnt_fs *dest,
+				     const struct libmnt_fs *src)
+			__ul_attribute__((warn_unused_result));
+extern void *mnt_fs_get_userdata(struct libmnt_fs *fs);
+extern int mnt_fs_set_userdata(struct libmnt_fs *fs, void *data);
+extern const char *mnt_fs_get_source(struct libmnt_fs *fs);
+extern int mnt_fs_set_source(struct libmnt_fs *fs, const char *source);
+extern const char *mnt_fs_get_srcpath(struct libmnt_fs *fs);
+extern int mnt_fs_get_table(struct libmnt_fs *fs, struct libmnt_table **tb);
+
+extern int mnt_fs_get_tag(struct libmnt_fs *fs, const char **name,
+			  const char **value);
+extern const char *mnt_fs_get_target(struct libmnt_fs *fs);
+extern int mnt_fs_set_target(struct libmnt_fs *fs, const char *tgt);
+extern const char *mnt_fs_get_fstype(struct libmnt_fs *fs);
+extern int mnt_fs_set_fstype(struct libmnt_fs *fs, const char *fstype);
+
+extern int mnt_fs_streq_srcpath(struct libmnt_fs *fs, const char *path)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_fs_streq_target(struct libmnt_fs *fs, const char *path)
+			__ul_attribute__((warn_unused_result));
+
+extern char *mnt_fs_strdup_options(struct libmnt_fs *fs)
+			__ul_attribute__((warn_unused_result));
+extern const char *mnt_fs_get_options(struct libmnt_fs *fs)
+			__ul_attribute__((warn_unused_result));
+extern const char *mnt_fs_get_optional_fields(struct libmnt_fs *fs)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_fs_get_propagation(struct libmnt_fs *fs, unsigned long *flags);
+
+extern int mnt_fs_set_options(struct libmnt_fs *fs, const char *optstr);
+extern int mnt_fs_append_options(struct libmnt_fs *fs, const char *optstr);
+extern int mnt_fs_prepend_options(struct libmnt_fs *fs, const char *optstr);
+
+extern int mnt_fs_get_option(struct libmnt_fs *fs, const char *name,
+				char **value, size_t *valsz);
+
+extern const char *mnt_fs_get_fs_options(struct libmnt_fs *fs);
+extern const char *mnt_fs_get_vfs_options(struct libmnt_fs *fs);
+extern const char *mnt_fs_get_user_options(struct libmnt_fs *fs);
+
+extern const char *mnt_fs_get_attributes(struct libmnt_fs *fs);
+extern int mnt_fs_set_attributes(struct libmnt_fs *fs, const char *optstr);
+extern int mnt_fs_get_attribute(struct libmnt_fs *fs, const char *name,
+				char **value, size_t *valsz);
+extern int mnt_fs_append_attributes(struct libmnt_fs *fs, const char *optstr);
+extern int mnt_fs_prepend_attributes(struct libmnt_fs *fs, const char *optstr);
+
+extern int mnt_fs_get_freq(struct libmnt_fs *fs);
+extern int mnt_fs_set_freq(struct libmnt_fs *fs, int freq);
+extern int mnt_fs_get_passno(struct libmnt_fs *fs);
+extern int mnt_fs_set_passno(struct libmnt_fs *fs, int passno);
+extern const char *mnt_fs_get_root(struct libmnt_fs *fs);
+extern int mnt_fs_set_root(struct libmnt_fs *fs, const char *path);
+extern const char *mnt_fs_get_bindsrc(struct libmnt_fs *fs);
+extern int mnt_fs_set_bindsrc(struct libmnt_fs *fs, const char *src);
+extern int mnt_fs_get_id(struct libmnt_fs *fs);
+extern int mnt_fs_get_parent_id(struct libmnt_fs *fs);
+extern dev_t mnt_fs_get_devno(struct libmnt_fs *fs);
+extern pid_t mnt_fs_get_tid(struct libmnt_fs *fs);
+
+extern const char *mnt_fs_get_swaptype(struct libmnt_fs *fs);
+extern off_t mnt_fs_get_size(struct libmnt_fs *fs);
+extern off_t mnt_fs_get_usedsize(struct libmnt_fs *fs);
+extern int mnt_fs_get_priority(struct libmnt_fs *fs);
+extern int mnt_fs_set_priority(struct libmnt_fs *fs, int prio);
+
+extern const char *mnt_fs_get_comment(struct libmnt_fs *fs);
+extern int mnt_fs_set_comment(struct libmnt_fs *fs, const char *comm);
+extern int mnt_fs_append_comment(struct libmnt_fs *fs, const char *comm);
+
+extern int mnt_fs_match_target(struct libmnt_fs *fs, const char *target,
+			       struct libmnt_cache *cache);
+extern int mnt_fs_match_source(struct libmnt_fs *fs, const char *source,
+			       struct libmnt_cache *cache);
+extern int mnt_fs_match_fstype(struct libmnt_fs *fs, const char *types);
+extern int mnt_fs_match_options(struct libmnt_fs *fs, const char *options);
+extern int mnt_fs_print_debug(struct libmnt_fs *fs, FILE *file);
+
+extern int mnt_fs_is_kernel(struct libmnt_fs *fs);
+extern int mnt_fs_is_swaparea(struct libmnt_fs *fs);
+extern int mnt_fs_is_netfs(struct libmnt_fs *fs);
+extern int mnt_fs_is_pseudofs(struct libmnt_fs *fs);
+
+extern void mnt_free_mntent(struct mntent *mnt);
+extern int mnt_fs_to_mntent(struct libmnt_fs *fs, struct mntent **mnt);
+
+/* tab-parse.c */
+extern struct libmnt_table *mnt_new_table_from_file(const char *filename)
+			__ul_attribute__((warn_unused_result));
+extern struct libmnt_table *mnt_new_table_from_dir(const char *dirname)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f,
+				  const char *filename);
+extern int mnt_table_parse_file(struct libmnt_table *tb, const char *filename);
+extern int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname);
+
+extern int mnt_table_parse_fstab(struct libmnt_table *tb, const char *filename);
+extern int mnt_table_parse_swaps(struct libmnt_table *tb, const char *filename);
+extern int mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename);
+extern int mnt_table_set_parser_errcb(struct libmnt_table *tb,
+                int (*cb)(struct libmnt_table *tb, const char *filename, int line));
+
+/* tab.c */
+extern struct libmnt_table *mnt_new_table(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_table(struct libmnt_table *tb);
+
+extern void mnt_ref_table(struct libmnt_table *tb);
+extern void mnt_unref_table(struct libmnt_table *tb);
+
+extern int mnt_reset_table(struct libmnt_table *tb);
+extern int mnt_table_get_nents(struct libmnt_table *tb);
+extern int mnt_table_is_empty(struct libmnt_table *tb);
+
+extern int mnt_table_set_userdata(struct libmnt_table *tb, void *data);
+extern void *mnt_table_get_userdata(struct libmnt_table *tb);
+
+extern void mnt_table_enable_comments(struct libmnt_table *tb, int enable);
+extern int mnt_table_with_comments(struct libmnt_table *tb);
+extern const char *mnt_table_get_intro_comment(struct libmnt_table *tb);
+extern int mnt_table_set_intro_comment(struct libmnt_table *tb, const char *comm);
+extern int mnt_table_append_intro_comment(struct libmnt_table *tb, const char *comm);
+extern int mnt_table_set_trailing_comment(struct libmnt_table *tb, const char *comm);
+extern const char *mnt_table_get_trailing_comment(struct libmnt_table *tb);
+extern int mnt_table_append_trailing_comment(struct libmnt_table *tb, const char *comm);
+
+extern int mnt_table_set_cache(struct libmnt_table *tb, struct libmnt_cache *mpc);
+extern struct libmnt_cache *mnt_table_get_cache(struct libmnt_table *tb);
+extern int mnt_table_add_fs(struct libmnt_table *tb, struct libmnt_fs *fs);
+extern int mnt_table_find_fs(struct libmnt_table *tb, struct libmnt_fs *fs);
+extern int mnt_table_insert_fs(struct libmnt_table *tb, int before,
+				struct libmnt_fs *pos, struct libmnt_fs *fs);
+extern int mnt_table_move_fs(struct libmnt_table *src, struct libmnt_table *dst,
+                      int before, struct libmnt_fs *pos, struct libmnt_fs *fs);
+extern int mnt_table_remove_fs(struct libmnt_table *tb, struct libmnt_fs *fs);
+extern int mnt_table_first_fs(struct libmnt_table *tb, struct libmnt_fs **fs);
+extern int mnt_table_last_fs(struct libmnt_table *tb, struct libmnt_fs **fs);
+extern int mnt_table_next_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
+			     struct libmnt_fs **fs);
+extern int mnt_table_next_child_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
+	                        struct libmnt_fs *parent, struct libmnt_fs **chld);
+extern int mnt_table_get_root_fs(struct libmnt_table *tb, struct libmnt_fs **root);
+extern int mnt_table_set_iter(struct libmnt_table *tb, struct libmnt_iter *itr,
+			      struct libmnt_fs *fs);
+
+enum {
+	MNT_UNIQ_FORWARD  = (1 << 1),	/* default is backward */
+	MNT_UNIQ_KEEPTREE = (1 << 2)
+};
+extern int mnt_table_uniq_fs(struct libmnt_table *tb, int flags,
+				int (*cmp)(struct libmnt_table *,
+					   struct libmnt_fs *,
+					   struct libmnt_fs *));
+
+extern struct libmnt_fs *mnt_table_find_mountpoint(struct libmnt_table *tb,
+				const char *path, int direction);
+extern struct libmnt_fs *mnt_table_find_target(struct libmnt_table *tb,
+				const char *path, int direction);
+extern struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb,
+				const char *path, int direction);
+extern struct libmnt_fs *mnt_table_find_tag(struct libmnt_table *tb, const char *tag,
+				const char *val, int direction);
+extern struct libmnt_fs *mnt_table_find_target_with_option(struct libmnt_table *tb, const char *path,
+			const char *option, const char *val, int direction);
+extern struct libmnt_fs *mnt_table_find_source(struct libmnt_table *tb,
+				const char *source, int direction);
+extern struct libmnt_fs *mnt_table_find_pair(struct libmnt_table *tb,
+				const char *source,
+				const char *target, int direction);
+extern struct libmnt_fs *mnt_table_find_devno(struct libmnt_table *tb,
+				dev_t devno, int direction);
+
+extern int mnt_table_find_next_fs(struct libmnt_table *tb,
+			struct libmnt_iter *itr,
+			int (*match_func)(struct libmnt_fs *, void *),
+			void *userdata,
+		        struct libmnt_fs **fs);
+
+extern int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs);
+
+/* tab_update.c */
+extern struct libmnt_update *mnt_new_update(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_update(struct libmnt_update *upd);
+
+extern int mnt_table_replace_file(struct libmnt_table *tb, const char *filename);
+extern int mnt_table_write_file(struct libmnt_table *tb, FILE *file);
+
+extern int mnt_update_is_ready(struct libmnt_update *upd);
+extern int mnt_update_set_fs(struct libmnt_update *upd, unsigned long mountflags,
+	                      const char *target, struct libmnt_fs *fs);
+extern int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc);
+extern unsigned long mnt_update_get_mflags(struct libmnt_update *upd);
+extern int mnt_update_force_rdonly(struct libmnt_update *upd, int rdonly);
+extern const char *mnt_update_get_filename(struct libmnt_update *upd);
+extern struct libmnt_fs *mnt_update_get_fs(struct libmnt_update *upd);
+
+/* tab_diff.c */
+enum {
+	MNT_TABDIFF_MOUNT = 1,
+	MNT_TABDIFF_UMOUNT,
+	MNT_TABDIFF_MOVE,
+	MNT_TABDIFF_REMOUNT,
+	MNT_TABDIFF_PROPAGATION,	/* not implemented yet (TODO) */
+};
+
+extern struct libmnt_tabdiff *mnt_new_tabdiff(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_tabdiff(struct libmnt_tabdiff *df);
+
+extern int mnt_diff_tables(struct libmnt_tabdiff *df,
+			   struct libmnt_table *old_tab,
+			   struct libmnt_table *new_tab);
+
+extern int mnt_tabdiff_next_change(struct libmnt_tabdiff *df,
+				   struct libmnt_iter *itr,
+				   struct libmnt_fs **old_fs,
+				   struct libmnt_fs **new_fs,
+				   int *oper);
+
+/* monitor.c */
+enum {
+	MNT_MONITOR_TYPE_USERSPACE = 1,	/* userspace mount options */
+	MNT_MONITOR_TYPE_KERNEL		/* kernel mount table */
+};
+
+extern struct libmnt_monitor *mnt_new_monitor(void);
+extern void mnt_ref_monitor(struct libmnt_monitor *mn);
+extern void mnt_unref_monitor(struct libmnt_monitor *mn);
+
+extern int mnt_monitor_enable_kernel(struct libmnt_monitor *mn, int enable);
+extern int mnt_monitor_enable_userspace(struct libmnt_monitor *mn,
+				int enable, const char *filename);
+
+extern int mnt_monitor_get_fd(struct libmnt_monitor *mn);
+extern int mnt_monitor_close_fd(struct libmnt_monitor *mn);
+extern int mnt_monitor_wait(struct libmnt_monitor *mn, int timeout);
+
+extern int mnt_monitor_next_change(struct libmnt_monitor *mn,
+			     const char **filename, int *type);
+extern int mnt_monitor_event_cleanup(struct libmnt_monitor *mn);
+
+
+/* context.c */
+
+/*
+ * Mode for mount options from fstab (or mtab), see mnt_context_set_optsmode().
+ */
+enum {
+	MNT_OMODE_IGNORE  = (1 << 1),	/* ignore mtab/fstab options */
+	MNT_OMODE_APPEND  = (1 << 2),	/* append mtab/fstab options to existing options */
+	MNT_OMODE_PREPEND = (1 << 3),	/* prepend mtab/fstab options to existing options */
+	MNT_OMODE_REPLACE = (1 << 4),	/* replace existing options with options from mtab/fstab */
+
+	MNT_OMODE_FORCE   = (1 << 5),   /* always read mtab/fstab options */
+
+	MNT_OMODE_FSTAB   = (1 << 10),	/* read from fstab */
+	MNT_OMODE_MTAB    = (1 << 11),	/* read from mtab if fstab not enabled or failed */
+	MNT_OMODE_NOTAB   = (1 << 12),	/* do not read fstab/mtab at all */
+
+	/* default */
+	MNT_OMODE_AUTO   = (MNT_OMODE_PREPEND | MNT_OMODE_FSTAB | MNT_OMODE_MTAB),
+	/* non-root users */
+	MNT_OMODE_USER   = (MNT_OMODE_REPLACE | MNT_OMODE_FORCE | MNT_OMODE_FSTAB)
+};
+
+extern struct libmnt_context *mnt_new_context(void)
+			__ul_attribute__((warn_unused_result));
+extern void mnt_free_context(struct libmnt_context *cxt);
+
+extern int mnt_reset_context(struct libmnt_context *cxt);
+extern int mnt_context_is_restricted(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_force_unrestricted(struct libmnt_context *cxt);
+
+extern int mnt_context_init_helper(struct libmnt_context *cxt,
+				   int action, int flags);
+extern int mnt_context_helper_setopt(struct libmnt_context *cxt, int c, char *arg);
+
+extern int mnt_context_set_optsmode(struct libmnt_context *cxt, int mode);
+extern int mnt_context_disable_canonicalize(struct libmnt_context *cxt, int disable);
+extern int mnt_context_enable_lazy(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_rdonly_umount(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_rwonly_mount(struct libmnt_context *cxt, int enable);
+extern int mnt_context_disable_helpers(struct libmnt_context *cxt, int disable);
+extern int mnt_context_enable_sloppy(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_fake(struct libmnt_context *cxt, int enable);
+extern int mnt_context_disable_mtab(struct libmnt_context *cxt, int disable);
+extern int mnt_context_enable_force(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_verbose(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_loopdel(struct libmnt_context *cxt, int enable);
+extern int mnt_context_enable_fork(struct libmnt_context *cxt, int enable);
+extern int mnt_context_disable_swapmatch(struct libmnt_context *cxt, int disable);
+
+extern int mnt_context_get_optsmode(struct libmnt_context *cxt);
+
+extern int mnt_context_is_lazy(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_rdonly_umount(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_rwonly_mount(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_sloppy(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_fake(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_nomtab(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_force(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_verbose(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_loopdel(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_nohelpers(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_nocanonicalize(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_swapmatch(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_forced_rdonly(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+
+extern int mnt_context_is_fork(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_parent(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+extern int mnt_context_is_child(struct libmnt_context *cxt)
+			__ul_attribute__((nonnull));
+
+extern int mnt_context_wait_for_children(struct libmnt_context *cxt,
+                                  int *nchildren, int *nerrs);
+
+extern int mnt_context_is_fs_mounted(struct libmnt_context *cxt,
+                              struct libmnt_fs *fs, int *mounted);
+extern int mnt_context_set_fs(struct libmnt_context *cxt, struct libmnt_fs *fs);
+extern struct libmnt_fs *mnt_context_get_fs(struct libmnt_context *cxt);
+
+extern int mnt_context_set_source(struct libmnt_context *cxt, const char *source);
+extern int mnt_context_set_target(struct libmnt_context *cxt, const char *target);
+extern int mnt_context_set_fstype(struct libmnt_context *cxt, const char *fstype);
+extern int mnt_context_set_target_prefix(struct libmnt_context *cxt, const char *path);
+
+extern const char *mnt_context_get_source(struct libmnt_context *cxt);
+extern const char *mnt_context_get_target(struct libmnt_context *cxt);
+extern const char *mnt_context_get_fstype(struct libmnt_context *cxt);
+extern const char *mnt_context_get_target_prefix(struct libmnt_context *cxt);
+
+extern void *mnt_context_get_mtab_userdata(struct libmnt_context *cxt);
+extern void *mnt_context_get_fstab_userdata(struct libmnt_context *cxt);
+extern void *mnt_context_get_fs_userdata(struct libmnt_context *cxt);
+
+extern int mnt_context_set_options(struct libmnt_context *cxt, const char *optstr);
+extern int mnt_context_append_options(struct libmnt_context *cxt, const char *optstr);
+
+extern const char *mnt_context_get_options(struct libmnt_context *cxt);
+
+extern int mnt_context_set_fstype_pattern(struct libmnt_context *cxt, const char *pattern);
+extern int mnt_context_set_options_pattern(struct libmnt_context *cxt, const char *pattern);
+
+extern int mnt_context_set_passwd_cb(struct libmnt_context *cxt,
+			      char *(*get)(struct libmnt_context *),
+			      void (*release)(struct libmnt_context *, char *))
+			__ul_attribute__((deprecated));
+
+extern int mnt_context_set_tables_errcb(struct libmnt_context *cxt,
+        int (*cb)(struct libmnt_table *tb, const char *filename, int line));
+extern int mnt_context_set_fstab(struct libmnt_context *cxt,
+				 struct libmnt_table *tb);
+extern int mnt_context_get_fstab(struct libmnt_context *cxt,
+				 struct libmnt_table **tb);
+
+extern int mnt_context_get_mtab(struct libmnt_context *cxt,
+				struct libmnt_table **tb);
+extern int mnt_context_get_table(struct libmnt_context *cxt,
+				const char *filename,
+				struct libmnt_table **tb);
+extern int mnt_context_set_cache(struct libmnt_context *cxt,
+				 struct libmnt_cache *cache);
+extern struct libmnt_cache *mnt_context_get_cache(struct libmnt_context *cxt);
+extern struct libmnt_lock *mnt_context_get_lock(struct libmnt_context *cxt);
+extern int mnt_context_set_mflags(struct libmnt_context *cxt,
+				      unsigned long flags);
+extern int mnt_context_get_mflags(struct libmnt_context *cxt,
+				      unsigned long *flags);
+extern int mnt_context_set_user_mflags(struct libmnt_context *cxt,
+						unsigned long flags);
+extern int mnt_context_get_user_mflags(struct libmnt_context *cxt,
+						unsigned long *flags);
+
+extern int mnt_context_set_mountdata(struct libmnt_context *cxt, void *data);
+extern int mnt_context_apply_fstab(struct libmnt_context *cxt);
+
+extern int mnt_context_reset_status(struct libmnt_context *cxt);
+extern int mnt_context_get_status(struct libmnt_context *cxt);
+
+extern int mnt_context_helper_executed(struct libmnt_context *cxt);
+extern int mnt_context_get_helper_status(struct libmnt_context *cxt);
+
+extern int mnt_context_syscall_called(struct libmnt_context *cxt);
+
+extern int mnt_context_get_syscall_errno(struct libmnt_context *cxt);
+
+extern int mnt_context_strerror(struct libmnt_context *cxt, char *buf,
+				size_t bufsiz)
+				__ul_attribute__((deprecated));
+
+extern int mnt_context_get_excode(struct libmnt_context *cxt,
+                        int rc, char *buf, size_t bufsz);
+
+extern int mnt_context_set_target_ns(struct libmnt_context *cxt, const char *path);
+extern struct libmnt_ns *mnt_context_get_target_ns(struct libmnt_context *cxt);
+extern struct libmnt_ns *mnt_context_get_origin_ns(struct libmnt_context *cxt);
+extern struct libmnt_ns *mnt_context_switch_ns(struct libmnt_context *cxt, struct libmnt_ns *ns);
+extern struct libmnt_ns *mnt_context_switch_origin_ns(struct libmnt_context *cxt);
+extern struct libmnt_ns *mnt_context_switch_target_ns(struct libmnt_context *cxt);
+
+
+/* context_mount.c */
+extern int mnt_context_mount(struct libmnt_context *cxt);
+extern int mnt_context_umount(struct libmnt_context *cxt);
+extern int mnt_context_next_mount(struct libmnt_context *cxt,
+				struct libmnt_iter *itr,
+				struct libmnt_fs **fs,
+				int *mntrc, int *ignored);
+
+extern int mnt_context_next_remount(struct libmnt_context *cxt,
+                           struct libmnt_iter *itr,
+                           struct libmnt_fs **fs,
+                           int *mntrc,
+                           int *ignored);
+
+extern int mnt_context_prepare_mount(struct libmnt_context *cxt)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_context_do_mount(struct libmnt_context *cxt);
+extern int mnt_context_finalize_mount(struct libmnt_context *cxt);
+
+/* context_umount.c */
+extern int mnt_context_find_umount_fs(struct libmnt_context *cxt,
+			       const char *tgt,
+			       struct libmnt_fs **pfs);
+extern int mnt_context_next_umount(struct libmnt_context *cxt,
+				struct libmnt_iter *itr,
+				struct libmnt_fs **fs,
+				int *mntrc, int *ignored);
+
+extern int mnt_context_prepare_umount(struct libmnt_context *cxt)
+			__ul_attribute__((warn_unused_result));
+extern int mnt_context_do_umount(struct libmnt_context *cxt);
+extern int mnt_context_finalize_umount(struct libmnt_context *cxt);
+
+extern int mnt_context_tab_applied(struct libmnt_context *cxt);
+extern int mnt_context_set_syscall_status(struct libmnt_context *cxt, int status);
+
+/*
+ * mount(8) userspace options masks (MNT_MAP_USERSPACE map)
+ */
+#define MNT_MS_NOAUTO	(1 << 2)
+#define MNT_MS_USER	(1 << 3)
+#define MNT_MS_USERS	(1 << 4)
+#define MNT_MS_OWNER	(1 << 5)
+#define MNT_MS_GROUP	(1 << 6)
+#define MNT_MS_NETDEV	(1 << 7)
+#define MNT_MS_COMMENT  (1 << 8)
+#define MNT_MS_LOOP     (1 << 9)
+#define MNT_MS_NOFAIL   (1 << 10)
+#define MNT_MS_UHELPER  (1 << 11)
+#define MNT_MS_HELPER   (1 << 12)
+#define MNT_MS_XCOMMENT (1 << 13)
+#define MNT_MS_OFFSET   (1 << 14)
+#define MNT_MS_SIZELIMIT (1 << 15)
+#define MNT_MS_ENCRYPTION (1 << 16)
+#define MNT_MS_XFSTABCOMM (1 << 17)
+#define MNT_MS_HASH_DEVICE (1 << 18)
+#define MNT_MS_ROOT_HASH (1 << 19)
+#define MNT_MS_HASH_OFFSET (1 << 20)
+#define MNT_MS_ROOT_HASH_FILE (1 << 21)
+#define MNT_MS_FEC_DEVICE (1 << 22)
+#define MNT_MS_FEC_OFFSET (1 << 23)
+#define MNT_MS_FEC_ROOTS (1 << 24)
+#define MNT_MS_ROOT_HASH_SIG (1 << 25)
+
+/*
+ * mount(2) MS_* masks (MNT_MAP_LINUX map)
+ */
+#ifndef MS_RDONLY
+#define MS_RDONLY	 1	/* Mount read-only */
+#endif
+#ifndef MS_NOSUID
+#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
+#endif
+#ifndef MS_NODEV
+#define MS_NODEV	 4	/* Disallow access to device special files */
+#endif
+#ifndef MS_NOEXEC
+#define MS_NOEXEC	 8	/* Disallow program execution */
+#endif
+#ifndef MS_SYNCHRONOUS
+#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
+#endif
+#ifndef MS_REMOUNT
+#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
+#endif
+#ifndef MS_MANDLOCK
+#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
+#endif
+#ifndef MS_DIRSYNC
+#define MS_DIRSYNC	128	/* Directory modifications are synchronous */
+#endif
+#ifndef MS_NOSYMFOLLOW
+#define MS_NOSYMFOLLOW	256	/* Don't follow symlinks */
+#endif
+#ifndef MS_NOATIME
+#define MS_NOATIME	0x400	/* 1024: Do not update access times. */
+#endif
+#ifndef MS_NODIRATIME
+#define MS_NODIRATIME   0x800	/* 2048: Don't update directory access times */
+#endif
+#ifndef MS_BIND
+#define	MS_BIND		0x1000	/* 4096: Mount existing tree elsewhere as well */
+#endif
+#ifndef MS_MOVE
+#define MS_MOVE		0x2000	/* 8192: Atomically move the tree */
+#endif
+#ifndef MS_REC
+#define MS_REC		0x4000	/* 16384: Recursive loopback */
+#endif
+#ifndef MS_SILENT
+#define MS_SILENT	0x8000	/* 32768: Don't emit certain kernel messages */
+#endif
+#ifndef MS_UNBINDABLE
+#define MS_UNBINDABLE	(1<<17)	/* 131072: Make unbindable */
+#endif
+#ifndef MS_PRIVATE
+#define MS_PRIVATE	(1<<18)	/* 262144: Make private */
+#endif
+#ifndef MS_SLAVE
+#define MS_SLAVE	(1<<19)	/* 524288: Make slave */
+#endif
+#ifndef MS_SHARED
+#define MS_SHARED	(1<<20)	/* 1048576: Make shared */
+#endif
+#ifndef MS_RELATIME
+#define MS_RELATIME	(1<<21) /* 2097152: Update atime relative to mtime/ctime */
+#endif
+#ifndef MS_I_VERSION
+#define MS_I_VERSION	(1<<23)	/* Update the inode I_version field */
+#endif
+#ifndef MS_STRICTATIME
+#define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
+#endif
+#ifndef MS_LAZYTIME
+#define MS_LAZYTIME     (1<<25) /* Update the on-disk [acm]times lazily */
+#endif
+
+
+/*
+ * Magic mount flag number. Had to be or-ed to the flag values.  Deprecated and
+ * no more used since libmount v2.33; required for Linux <= 2.4.
+ */
+#ifndef MS_MGC_VAL
+#define MS_MGC_VAL 0xC0ED0000	/* magic flag number to indicate "new" flags */
+#endif
+#ifndef MS_MGC_MSK
+#define MS_MGC_MSK 0xffff0000	/* magic flag number mask */
+#endif
+
+
+/* Shared-subtree options */
+#define MS_PROPAGATION  (MS_SHARED|MS_SLAVE|MS_UNBINDABLE|MS_PRIVATE)
+
+/* Options that we make ordinary users have by default.  */
+#define MS_SECURE	(MS_NOEXEC|MS_NOSUID|MS_NODEV)
+
+/* Options that we make owner-mounted devices have by default */
+#define MS_OWNERSECURE	(MS_NOSUID|MS_NODEV)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _LIBMOUNT_MOUNT_H */
diff --git a/libmount/src/libmount.sym b/libmount/src/libmount.sym
new file mode 100644
index 0000000..792d117
--- /dev/null
+++ b/libmount/src/libmount.sym
@@ -0,0 +1,358 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2011-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ *
+ * The symbol versioning ensures that a new application requiring symbol foo,
+ * can't run with old library.so not providing foo.
+ *
+ * Version info can't enforce this since we never change the SONAME.
+ */
+MOUNT_2.19 {
+global:
+	mnt_cache_device_has_tag;
+	mnt_cache_find_tag_value;
+	mnt_cache_read_tags;
+	mnt_context_append_options;
+	mnt_context_apply_fstab;
+	mnt_context_disable_canonicalize;
+	mnt_context_disable_helpers;
+	mnt_context_disable_mtab;
+	mnt_context_do_mount;
+	mnt_context_do_umount;
+	mnt_context_enable_fake;
+	mnt_context_enable_force;
+	mnt_context_enable_lazy;
+	mnt_context_enable_loopdel;
+	mnt_context_enable_rdonly_umount;
+	mnt_context_enable_sloppy;
+	mnt_context_enable_verbose;
+	mnt_context_finalize_mount;
+	mnt_context_finalize_umount;
+	mnt_context_get_cache;
+	mnt_context_get_fs;
+	mnt_context_get_fstab;
+	mnt_context_get_fstype;
+	mnt_context_get_lock;
+	mnt_context_get_mflags;
+	mnt_context_get_mtab;
+	mnt_context_get_optsmode;
+	mnt_context_get_source;
+	mnt_context_get_status;
+	mnt_context_get_target;
+	mnt_context_get_user_mflags;
+	mnt_context_helper_setopt;
+	mnt_context_init_helper;
+	mnt_context_is_fake;
+	mnt_context_is_force;
+	mnt_context_is_lazy;
+	mnt_context_is_nomtab;
+	mnt_context_is_rdonly_umount;
+	mnt_context_is_restricted;
+	mnt_context_is_sloppy;
+	mnt_context_is_verbose;
+	mnt_context_mount;
+	mnt_context_prepare_mount;
+	mnt_context_prepare_umount;
+	mnt_context_set_cache;
+	mnt_context_set_fs;
+	mnt_context_set_fstab;
+	mnt_context_set_fstype;
+	mnt_context_set_fstype_pattern;
+	mnt_context_set_mflags;
+	mnt_context_set_mountdata;
+	mnt_context_set_options;
+	mnt_context_set_options_pattern;
+	mnt_context_set_optsmode;
+	mnt_context_set_source;
+	mnt_context_set_syscall_status;
+	mnt_context_set_target;
+	mnt_context_set_user_mflags;
+	mnt_context_strerror;
+	mnt_context_umount;
+	mnt_copy_fs;
+	mnt_free_cache;
+	mnt_free_context;
+	mnt_free_fs;
+	mnt_free_iter;
+	mnt_free_lock;
+	mnt_free_mntent;
+	mnt_free_table;
+	mnt_free_update;
+	mnt_fs_append_attributes;
+	mnt_fs_append_options;
+	mnt_fs_get_attribute;
+	mnt_fs_get_attributes;
+	mnt_fs_get_bindsrc;
+	mnt_fs_get_devno;
+	mnt_fs_get_freq;
+	mnt_fs_get_fs_options;
+	mnt_fs_get_fstype;
+	mnt_fs_get_id;
+	mnt_fs_get_option;
+	mnt_fs_get_parent_id;
+	mnt_fs_get_passno;
+	mnt_fs_get_root;
+	mnt_fs_get_source;
+	mnt_fs_get_srcpath;
+	mnt_fs_get_tag;
+	mnt_fs_get_target;
+	mnt_fs_get_userdata;
+	mnt_fs_get_user_options;
+	mnt_fs_get_vfs_options;
+	mnt_fs_is_kernel;
+	mnt_fs_match_fstype;
+	mnt_fs_match_options;
+	mnt_fs_match_source;
+	mnt_fs_match_target;
+	mnt_fs_prepend_attributes;
+	mnt_fs_prepend_options;
+	mnt_fs_print_debug;
+	mnt_fs_set_attributes;
+	mnt_fs_set_bindsrc;
+	mnt_fs_set_freq;
+	mnt_fs_set_fstype;
+	mnt_fs_set_options;
+	mnt_fs_set_passno;
+	mnt_fs_set_root;
+	mnt_fs_set_source;
+	mnt_fs_set_target;
+	mnt_fs_set_userdata;
+	mnt_fs_strdup_options;
+	mnt_fs_to_mntent;
+	mnt_fstype_is_netfs;
+	mnt_fstype_is_pseudofs;
+	mnt_get_builtin_optmap;
+	mnt_get_fstab_path;
+	mnt_get_fstype;
+	mnt_get_library_version;
+	mnt_get_mtab_path;
+	mnt_has_regular_mtab;
+	mnt_init_debug;
+	mnt_iter_get_direction;
+	mnt_lock_file;
+	mnt_mangle;
+	mnt_match_fstype;
+	mnt_match_options;
+	mnt_new_cache;
+	mnt_new_context;
+	mnt_new_fs;
+	mnt_new_iter;
+	mnt_new_lock;
+	mnt_new_table;
+	mnt_new_table_from_dir;
+	mnt_new_table_from_file;
+	mnt_new_update;
+	mnt_optstr_append_option;
+	mnt_optstr_apply_flags;
+	mnt_optstr_get_flags;
+	mnt_optstr_get_option;
+	mnt_optstr_get_options;
+	mnt_optstr_next_option;
+	mnt_optstr_prepend_option;
+	mnt_optstr_remove_option;
+	mnt_optstr_set_option;
+	mnt_parse_version_string;
+	mnt_reset_context;
+	mnt_reset_fs;
+	mnt_reset_iter;
+	mnt_resolve_path;
+	mnt_resolve_spec;
+	mnt_resolve_tag;
+	mnt_split_optstr;
+	mnt_table_add_fs;
+	mnt_table_find_next_fs;
+	mnt_table_find_pair;
+	mnt_table_find_source;
+	mnt_table_find_srcpath;
+	mnt_table_find_tag;
+	mnt_table_find_target;
+	mnt_table_get_cache;
+	mnt_table_get_nents;
+	mnt_table_get_root_fs;
+	mnt_table_next_child_fs;
+	mnt_table_next_fs;
+	mnt_table_parse_file;
+	mnt_table_parse_fstab;
+	mnt_table_parse_mtab;
+	mnt_table_parse_stream;
+	mnt_table_remove_fs;
+	mnt_table_set_cache;
+	mnt_table_set_iter;
+	mnt_table_set_parser_errcb;
+	mnt_unlock_file;
+	mnt_unmangle;
+	mnt_update_force_rdonly;
+	mnt_update_get_filename;
+	mnt_update_get_fs;
+	mnt_update_get_mflags;
+	mnt_update_is_ready;
+	mnt_update_set_fs;
+	mnt_update_table;
+local:
+	*;
+};
+
+MOUNT_2.20 {
+global:
+	mnt_context_get_table;
+	mnt_context_is_fs_mounted;
+	mnt_context_next_mount;
+	mnt_context_set_tables_errcb;
+	mnt_diff_tables;
+	mnt_free_tabdiff;
+	mnt_fs_get_options;
+	mnt_lock_block_signals;
+	mnt_new_tabdiff;
+	mnt_pretty_path;
+	mnt_reset_table;
+	mnt_tabdiff_next_change;
+	mnt_table_is_fs_mounted;
+} MOUNT_2.19;
+
+MOUNT_2.21 {
+global:
+	mnt_context_enable_fork;
+	mnt_context_get_helper_status;
+	mnt_context_get_syscall_errno;
+	mnt_context_helper_executed;
+	mnt_context_is_child;
+	mnt_context_is_fork;
+	mnt_context_is_parent;
+	mnt_context_next_umount;
+	mnt_context_reset_status;
+	mnt_context_set_passwd_cb;
+	mnt_context_syscall_called;
+	mnt_context_wait_for_children;
+	mnt_fs_is_netfs;
+	mnt_fs_is_pseudofs;
+	mnt_fs_is_swaparea;
+	mnt_get_library_features;
+	mnt_table_parse_dir;
+} MOUNT_2.20;
+
+MOUNT_2.22 {
+global:
+	mnt_context_disable_swapmatch;
+	mnt_context_get_options;
+	mnt_context_is_loopdel;
+	mnt_context_is_nocanonicalize;
+	mnt_context_is_nohelpers;
+	mnt_context_is_swapmatch;
+	mnt_context_tab_applied;
+	mnt_fs_get_priority;
+	mnt_fs_get_size;
+	mnt_fs_get_swaptype;
+	mnt_fs_get_tid;
+	mnt_fs_get_usedsize;
+	mnt_fs_streq_srcpath;
+	mnt_fs_streq_target;
+	mnt_get_mountpoint;
+	mnt_get_swaps_path;
+	mnt_optstr_deduplicate_option;
+	mnt_table_find_devno;
+	mnt_table_parse_swaps;
+} MOUNT_2.21;
+
+MOUNT_2.23 {
+global:
+	mnt_fs_get_optional_fields;
+	mnt_fs_get_propagation;
+	mnt_context_find_umount_fs;
+	mnt_table_find_mountpoint;
+} MOUNT_2.22;
+
+MOUNT_2.24 {
+global:
+	mnt_context_get_fstab_userdata;
+	mnt_context_get_fs_userdata;
+	mnt_context_get_mtab_userdata;
+	mnt_fs_append_comment;
+	mnt_fs_get_comment;
+	mnt_fs_set_comment;
+	mnt_ref_cache;
+	mnt_ref_fs;
+	mnt_ref_table;
+	mnt_table_append_intro_comment;
+	mnt_table_append_trailing_comment;
+	mnt_table_enable_comments;
+	mnt_table_first_fs;
+	mnt_table_get_intro_comment;
+	mnt_table_get_trailing_comment;
+	mnt_table_get_userdata;
+	mnt_table_is_empty;
+	mnt_table_last_fs;
+	mnt_table_replace_file;
+	mnt_table_set_intro_comment;
+	mnt_table_set_trailing_comment;
+	mnt_table_set_userdata;
+	mnt_table_with_comments;
+	mnt_table_write_file;
+	mnt_unref_cache;
+	mnt_unref_fs;
+	mnt_unref_table;
+} MOUNT_2.23;
+
+MOUNT_2.25 {
+	mnt_cache_set_targets;
+	mnt_resolve_target;
+	mnt_table_uniq_fs;
+	mnt_tag_is_valid;
+} MOUNT_2.24;
+
+MOUNT_2.26 {
+	mnt_monitor_close_fd;
+	mnt_monitor_enable_userspace;
+	mnt_monitor_enable_kernel;
+	mnt_monitor_event_cleanup;
+	mnt_monitor_get_fd;
+	mnt_monitor_next_change;
+	mnt_monitor_wait;
+	mnt_new_monitor;
+	mnt_ref_monitor;
+	mnt_unref_monitor;
+} MOUNT_2.25;
+
+MOUNT_2.28 {
+	mnt_table_find_target_with_option;
+	mnt_fs_set_priority;
+} MOUNT_2.26;
+
+MOUNT_2.30 {
+	mnt_context_is_rwonly_mount;
+	mnt_context_forced_rdonly;
+	mnt_context_enable_rwonly_mount;
+	mnt_context_get_excode;
+} MOUNT_2.28;
+
+MOUNT_2.33 {
+	mnt_context_get_origin_ns;
+	mnt_context_get_target_ns;
+	mnt_context_set_target_ns;
+	mnt_context_switch_ns;
+	mnt_context_switch_origin_ns;
+	mnt_context_switch_target_ns;
+} MOUNT_2.30;
+
+MOUNT_2.34 {
+	mnt_context_next_remount;
+	mnt_fs_get_table;
+	mnt_guess_system_root;
+	mnt_table_find_fs;
+	mnt_table_insert_fs;
+	mnt_table_move_fs;
+} MOUNT_2.33;
+
+MOUNT_2_35 {
+	mnt_context_force_unrestricted;
+	mnt_context_get_target_prefix;
+	mnt_context_set_target_prefix;
+} MOUNT_2.34;
diff --git a/libmount/src/lock.c b/libmount/src/lock.c
new file mode 100644
index 0000000..cc5340d
--- /dev/null
+++ b/libmount/src/lock.c
@@ -0,0 +1,732 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: lock
+ * @title: Locking
+ * @short_description: locking methods for /etc/mtab or another libmount files
+ *
+ * The mtab lock is backwards compatible with the standard linux /etc/mtab
+ * locking.  Note, it's necessary to use the same locking schema in all
+ * applications that access the file.
+ */
+#include <sys/time.h>
+#include <time.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/file.h>
+
+#include "strutils.h"
+#include "closestream.h"
+#include "pathnames.h"
+#include "mountP.h"
+#include "monotonic.h"
+
+/*
+ * lock handler
+ */
+struct libmnt_lock {
+	char	*lockfile;	/* path to lock file (e.g. /etc/mtab~) */
+	char	*linkfile;	/* path to link file (e.g. /etc/mtab~.<id>) */
+	int	lockfile_fd;	/* lock file descriptor */
+
+	unsigned int	locked :1,	/* do we own the lock? */
+			sigblock :1,	/* block signals when locked */
+			simplelock :1;	/* use flock rather than normal mtab lock */
+
+	sigset_t oldsigmask;
+};
+
+
+/**
+ * mnt_new_lock:
+ * @datafile: the file that should be covered by the lock
+ * @id: unique linkfile identifier or 0 (default is getpid())
+ *
+ * Returns: newly allocated lock handler or NULL on case of error.
+ */
+struct libmnt_lock *mnt_new_lock(const char *datafile, pid_t id)
+{
+	struct libmnt_lock *ml = NULL;
+	char *lo = NULL, *ln = NULL;
+	size_t losz;
+
+	if (!datafile)
+		return NULL;
+
+	/* for flock we use "foo.lock, for mtab "foo~"
+	 */
+	losz = strlen(datafile) + sizeof(".lock");
+	lo = malloc(losz);
+	if (!lo)
+		goto err;
+
+	/* default is mtab~ lock */
+	snprintf(lo, losz, "%s~", datafile);
+
+	if (asprintf(&ln, "%s~.%d", datafile, id ? : getpid()) == -1) {
+		ln = NULL;
+		goto err;
+	}
+	ml = calloc(1, sizeof(*ml) );
+	if (!ml)
+		goto err;
+
+	ml->lockfile_fd = -1;
+	ml->linkfile = ln;
+	ml->lockfile = lo;
+
+	DBG(LOCKS, ul_debugobj(ml, "alloc: default linkfile=%s, lockfile=%s", ln, lo));
+	return ml;
+err:
+	free(lo);
+	free(ln);
+	free(ml);
+	return NULL;
+}
+
+
+/**
+ * mnt_free_lock:
+ * @ml: struct libmnt_lock handler
+ *
+ * Deallocates mnt_lock.
+ */
+void mnt_free_lock(struct libmnt_lock *ml)
+{
+	if (!ml)
+		return;
+	DBG(LOCKS, ul_debugobj(ml, "free%s", ml->locked ? " !!! LOCKED !!!" : ""));
+	free(ml->lockfile);
+	free(ml->linkfile);
+	free(ml);
+}
+
+/**
+ * mnt_lock_block_signals:
+ * @ml: struct libmnt_lock handler
+ * @enable: TRUE/FALSE
+ *
+ * Block/unblock signals when the lock is locked, the signals are not blocked
+ * by default.
+ *
+ * Returns: <0 on error, 0 on success.
+ */
+int mnt_lock_block_signals(struct libmnt_lock *ml, int enable)
+{
+	if (!ml)
+		return -EINVAL;
+	DBG(LOCKS, ul_debugobj(ml, "signals: %s", enable ? "BLOCKED" : "UNBLOCKED"));
+	ml->sigblock = enable ? 1 : 0;
+	return 0;
+}
+
+/* don't export this to API
+ */
+int mnt_lock_use_simplelock(struct libmnt_lock *ml, int enable)
+{
+	size_t sz;
+
+	if (!ml)
+		return -EINVAL;
+
+	assert(ml->lockfile);
+
+	DBG(LOCKS, ul_debugobj(ml, "flock: %s", enable ? "ENABLED" : "DISABLED"));
+	ml->simplelock = enable ? 1 : 0;
+
+	sz = strlen(ml->lockfile);
+	assert(sz);
+
+	if (sz < 1)
+		return -EINVAL;
+
+	/* Change lock name:
+	 *
+	 *	flock:     "<name>.lock"
+	 *	mtab lock: "<name>~"
+	 */
+	if (ml->simplelock && endswith(ml->lockfile, "~"))
+		memcpy(ml->lockfile + sz - 1, ".lock", 6);
+
+	else if (!ml->simplelock && endswith(ml->lockfile, ".lock"))
+		 memcpy(ml->lockfile + sz - 5, "~", 2);
+
+	DBG(LOCKS, ul_debugobj(ml, "new lock filename: '%s'", ml->lockfile));
+	return 0;
+}
+
+/*
+ * Returns path to lockfile.
+ */
+static const char *mnt_lock_get_lockfile(struct libmnt_lock *ml)
+{
+	return ml ? ml->lockfile : NULL;
+}
+
+/*
+ * Note that the filename is generated by mnt_new_lock() and depends on
+ * getpid() or 'id' argument of the mnt_new_lock() function.
+ *
+ * Returns: unique (per process/thread) path to linkfile.
+ */
+static const char *mnt_lock_get_linkfile(struct libmnt_lock *ml)
+{
+	return ml ? ml->linkfile : NULL;
+}
+
+/*
+ * Simple flocking
+ */
+static void unlock_simplelock(struct libmnt_lock *ml)
+{
+	assert(ml);
+	assert(ml->simplelock);
+
+	if (ml->lockfile_fd >= 0) {
+		DBG(LOCKS, ul_debugobj(ml, "%s: unflocking",
+					mnt_lock_get_lockfile(ml)));
+		close(ml->lockfile_fd);
+	}
+}
+
+static int lock_simplelock(struct libmnt_lock *ml)
+{
+	const char *lfile;
+	int rc;
+	struct stat sb;
+	const mode_t lock_mask = S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH;
+
+	assert(ml);
+	assert(ml->simplelock);
+
+	lfile = mnt_lock_get_lockfile(ml);
+
+	DBG(LOCKS, ul_debugobj(ml, "%s: locking", lfile));
+
+	if (ml->sigblock) {
+		sigset_t sigs;
+		sigemptyset(&ml->oldsigmask);
+		sigfillset(&sigs);
+		sigprocmask(SIG_BLOCK, &sigs, &ml->oldsigmask);
+	}
+
+	ml->lockfile_fd = open(lfile, O_RDONLY|O_CREAT|O_CLOEXEC,
+				      S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH);
+	if (ml->lockfile_fd < 0) {
+		rc = -errno;
+		goto err;
+	}
+
+	rc = fstat(ml->lockfile_fd, &sb);
+	if (rc < 0) {
+		rc = -errno;
+		goto err;
+	}
+
+	if ((sb.st_mode & lock_mask) != lock_mask) {
+		rc = fchmod(ml->lockfile_fd, lock_mask);
+		if (rc < 0) {
+			rc = -errno;
+			goto err;
+		}
+	}
+
+	while (flock(ml->lockfile_fd, LOCK_EX) < 0) {
+		int errsv;
+		if ((errno == EAGAIN) || (errno == EINTR))
+			continue;
+		errsv = errno;
+		close(ml->lockfile_fd);
+		ml->lockfile_fd = -1;
+		rc = -errsv;
+		goto err;
+	}
+	ml->locked = 1;
+	return 0;
+err:
+	if (ml->sigblock)
+		sigprocmask(SIG_SETMASK, &ml->oldsigmask, NULL);
+	return rc;
+}
+
+/*
+ * traditional mtab locking
+ */
+
+static void mnt_lockalrm_handler(int sig __attribute__((__unused__)))
+{
+	/* do nothing, say nothing, be nothing */
+}
+
+/*
+ * Waits for F_SETLKW, unfortunately we have to use SIGALRM here to interrupt
+ * fcntl() to avoid neverending waiting.
+ *
+ * Returns: 0 on success, 1 on timeout, -errno on error.
+ */
+static int mnt_wait_mtab_lock(struct libmnt_lock *ml, struct flock *fl, time_t maxtime)
+{
+	struct timeval now;
+	struct sigaction sa, osa;
+	int ret = 0;
+
+	gettime_monotonic(&now);
+	DBG(LOCKS, ul_debugobj(ml, "(%d) waiting for F_SETLKW (now=%lu, maxtime=%lu, diff=%lu)",
+				getpid(),
+				(unsigned long) now.tv_sec,
+				(unsigned long) maxtime,
+				(unsigned long) (maxtime - now.tv_sec)));
+
+	if (now.tv_sec >= maxtime)
+		return 1;		/* timeout */
+
+	/* setup ALARM handler -- we don't want to wait forever */
+	sa.sa_flags = 0;
+	sa.sa_handler = mnt_lockalrm_handler;
+	sigfillset (&sa.sa_mask);
+
+	sigaction(SIGALRM, &sa, &osa);
+
+
+	alarm(maxtime - now.tv_sec);
+	if (fcntl(ml->lockfile_fd, F_SETLKW, fl) == -1)
+		ret = errno == EINTR ? 1 : -errno;
+	alarm(0);
+
+	/* restore old sigaction */
+	sigaction(SIGALRM, &osa, NULL);
+
+	DBG(LOCKS, ul_debugobj(ml, "(%d) leaving mnt_wait_setlkw(), rc=%d",
+				getpid(), ret));
+	return ret;
+}
+
+/*
+ * Create the mtab lock file.
+ *
+ * The old code here used flock on a lock file /etc/mtab~ and deleted
+ * this lock file afterwards. However, as rgooch remarks, that has a
+ * race: a second mount may be waiting on the lock and proceed as
+ * soon as the lock file is deleted by the first mount, and immediately
+ * afterwards a third mount comes, creates a new /etc/mtab~, applies
+ * flock to that, and also proceeds, so that the second and third mount
+ * are now both scribbling in /etc/mtab.
+ *
+ * The new code uses a link() instead of a creat(), where we proceed
+ * only if it was us that created the lock, and hence we always have
+ * to delete the lock afterwards. Now the use of flock() is in principle
+ * superfluous, but avoids an arbitrary sleep().
+ *
+ * Where does the link point to? Obvious choices are mtab and mtab~~.
+ * HJLu points out that the latter leads to races. Right now we use
+ * mtab~.pid instead.
+ *
+ *
+ * The original mount locking code has used sleep(1) between attempts and
+ * maximal number of attempts has been 5.
+ *
+ * There was a very small number of attempts and extremely long waiting (1s)
+ * that is useless on machines with large number of mount processes.
+ *
+ * Now we wait for a few thousand microseconds between attempts and we have a global
+ * time limit (30s) rather than a limit for the number of attempts. The advantage
+ * is that this method also counts time which we spend in fcntl(F_SETLKW) and
+ * the number of attempts is not restricted.
+ * -- kzak@redhat.com [Mar-2007]
+ *
+ *
+ * This mtab locking code has been refactored and moved to libmount. The mtab
+ * locking is really not perfect (e.g. SIGALRM), but it's stable, reliable and
+ * backwardly compatible code.
+ *
+ * Don't forget that this code has to be compatible with 3rd party mounts
+ * (/sbin/mount.foo) and has to work with NFS.
+ * -- kzak@redhat.com [May-2009]
+ */
+
+/* maximum seconds between the first and the last attempt */
+#define MOUNTLOCK_MAXTIME		30
+
+/* sleep time (in microseconds, max=999999) between attempts */
+#define MOUNTLOCK_WAITTIME		5000
+
+static void unlock_mtab(struct libmnt_lock *ml)
+{
+	if (!ml)
+		return;
+
+	if (!ml->locked && ml->lockfile && ml->linkfile)
+	{
+		/* We (probably) have all the files, but we don't own the lock,
+		 * Really? Check it! Maybe ml->locked wasn't set properly
+		 * because the code was interrupted by a signal. Paranoia? Yes.
+		 *
+		 * We own the lock when linkfile == lockfile.
+		 */
+		struct stat lo, li;
+
+		if (!stat(ml->lockfile, &lo) && !stat(ml->linkfile, &li) &&
+		    lo.st_dev == li.st_dev && lo.st_ino == li.st_ino)
+			ml->locked = 1;
+	}
+
+	if (ml->linkfile)
+		unlink(ml->linkfile);
+	if (ml->lockfile_fd >= 0)
+		close(ml->lockfile_fd);
+	if (ml->locked && ml->lockfile) {
+		unlink(ml->lockfile);
+		DBG(LOCKS, ul_debugobj(ml, "unlink %s", ml->lockfile));
+	}
+}
+
+static int lock_mtab(struct libmnt_lock *ml)
+{
+	int i, rc = -1;
+	struct timespec waittime;
+	struct timeval maxtime;
+	const char *lockfile, *linkfile;
+
+	if (!ml)
+		return -EINVAL;
+	if (ml->locked)
+		return 0;
+
+	lockfile = mnt_lock_get_lockfile(ml);
+	if (!lockfile)
+		return -EINVAL;
+	linkfile = mnt_lock_get_linkfile(ml);
+	if (!linkfile)
+		return -EINVAL;
+
+	if (ml->sigblock) {
+		/*
+		 * Block all signals when locked, mnt_unlock_file() will
+		 * restore the old mask.
+		 */
+		sigset_t sigs;
+
+		sigemptyset(&ml->oldsigmask);
+		sigfillset(&sigs);
+		sigdelset(&sigs, SIGTRAP);
+		sigdelset(&sigs, SIGALRM);
+		sigprocmask(SIG_BLOCK, &sigs, &ml->oldsigmask);
+	}
+
+	i = open(linkfile, O_WRONLY|O_CREAT|O_CLOEXEC, S_IRUSR|S_IWUSR);
+	if (i < 0) {
+		/* linkfile does not exist (as a file) and we cannot create it.
+		 * Read-only or full filesystem? Too many files open in the system?
+		 */
+		if (errno > 0)
+			rc = -errno;
+		goto failed;
+	}
+	close(i);
+
+	gettime_monotonic(&maxtime);
+	maxtime.tv_sec += MOUNTLOCK_MAXTIME;
+
+	waittime.tv_sec = 0;
+	waittime.tv_nsec = (1000 * MOUNTLOCK_WAITTIME);
+
+	/* Repeat until it was us who made the link */
+	while (!ml->locked) {
+		struct timeval now;
+		struct flock flock;
+		int j;
+
+		j = link(linkfile, lockfile);
+		if (j == 0)
+			ml->locked = 1;
+
+		if (j < 0 && errno != EEXIST) {
+			if (errno > 0)
+				rc = -errno;
+			goto failed;
+		}
+		ml->lockfile_fd = open(lockfile, O_WRONLY|O_CLOEXEC);
+
+		if (ml->lockfile_fd < 0) {
+			/* Strange... Maybe the file was just deleted? */
+			int errsv = errno;
+			gettime_monotonic(&now);
+			if (errsv == ENOENT && now.tv_sec < maxtime.tv_sec) {
+				ml->locked = 0;
+				continue;
+			}
+			if (errsv > 0)
+				rc = -errsv;
+			goto failed;
+		}
+
+		flock.l_type = F_WRLCK;
+		flock.l_whence = SEEK_SET;
+		flock.l_start = 0;
+		flock.l_len = 0;
+
+		if (ml->locked) {
+			/* We made the link. Now claim the lock. */
+			if (fcntl (ml->lockfile_fd, F_SETLK, &flock) == -1) {
+				DBG(LOCKS, ul_debugobj(ml,
+					"%s: can't F_SETLK lockfile, errno=%d\n",
+					lockfile, errno));
+				/* proceed, since it was us who created the lockfile anyway */
+			}
+			break;
+		}
+
+		/* Someone else made the link. Wait. */
+		int err = mnt_wait_mtab_lock(ml, &flock, maxtime.tv_sec);
+
+		if (err == 1) {
+			DBG(LOCKS, ul_debugobj(ml,
+				"%s: can't create link: time out (perhaps "
+				"there is a stale lock file?)", lockfile));
+			rc = -ETIMEDOUT;
+			goto failed;
+
+		} else if (err < 0) {
+			rc = err;
+			goto failed;
+		}
+		nanosleep(&waittime, NULL);
+		close(ml->lockfile_fd);
+		ml->lockfile_fd = -1;
+	}
+	DBG(LOCKS, ul_debugobj(ml, "%s: (%d) successfully locked",
+					lockfile, getpid()));
+	unlink(linkfile);
+	return 0;
+
+failed:
+	mnt_unlock_file(ml);
+	return rc;
+}
+
+
+/**
+ * mnt_lock_file
+ * @ml: pointer to struct libmnt_lock instance
+ *
+ * Creates a lock file (e.g. /etc/mtab~). Note that this function may
+ * use alarm().
+ *
+ * Your application always has to call mnt_unlock_file() before exit.
+ *
+ * Traditional mtab locking scheme:
+ *
+ *   1. create linkfile (e.g. /etc/mtab~.$PID)
+ *   2. link linkfile --> lockfile (e.g. /etc/mtab~.$PID --> /etc/mtab~)
+ *   3. a) link() success: setups F_SETLK lock (see fcntl(2))
+ *      b) link() failed:  wait (max 30s) on F_SETLKW lock, goto 2.
+ *
+ * Note that when the lock is used by mnt_update_table() interface then libmount
+ * uses flock() for private library file /run/mount/utab. The fcntl(2) is used only
+ * for backwardly compatible stuff like /etc/mtab.
+ *
+ * Returns: 0 on success or negative number in case of error (-ETIMEOUT is case
+ * of stale lock file).
+ */
+int mnt_lock_file(struct libmnt_lock *ml)
+{
+	if (!ml)
+		return -EINVAL;
+
+	if (ml->simplelock)
+		return lock_simplelock(ml);
+
+	return lock_mtab(ml);
+}
+
+/**
+ * mnt_unlock_file:
+ * @ml: lock struct
+ *
+ * Unlocks the file. The function could be called independently of the
+ * lock status (for example from exit(3)).
+ */
+void mnt_unlock_file(struct libmnt_lock *ml)
+{
+	if (!ml)
+		return;
+
+	DBG(LOCKS, ul_debugobj(ml, "(%d) %s", getpid(),
+			ml->locked ? "unlocking" : "cleaning"));
+
+	if (ml->simplelock)
+		unlock_simplelock(ml);
+	else
+		unlock_mtab(ml);
+
+	ml->locked = 0;
+	ml->lockfile_fd = -1;
+
+	if (ml->sigblock) {
+		DBG(LOCKS, ul_debugobj(ml, "restoring sigmask"));
+		sigprocmask(SIG_SETMASK, &ml->oldsigmask, NULL);
+	}
+}
+
+#ifdef TEST_PROGRAM
+
+static struct libmnt_lock *lock;
+
+/*
+ * read number from @filename, increment the number and
+ * write the number back to the file
+ */
+static void increment_data(const char *filename, int verbose, int loopno)
+{
+	long num;
+	FILE *f;
+	char buf[256];
+
+	if (!(f = fopen(filename, "r" UL_CLOEXECSTR)))
+		err(EXIT_FAILURE, "%d: failed to open: %s", getpid(), filename);
+
+	if (!fgets(buf, sizeof(buf), f))
+		err(EXIT_FAILURE, "%d failed read: %s", getpid(), filename);
+
+	fclose(f);
+	num = atol(buf) + 1;
+
+	if (!(f = fopen(filename, "w" UL_CLOEXECSTR)))
+		err(EXIT_FAILURE, "%d: failed to open: %s", getpid(), filename);
+
+	fprintf(f, "%ld", num);
+
+	if (close_stream(f) != 0)
+		err(EXIT_FAILURE, "write failed: %s", filename);
+
+	if (verbose)
+		fprintf(stderr, "%d: %s: %ld --> %ld (loop=%d)\n", getpid(),
+				filename, num - 1, num, loopno);
+}
+
+static void clean_lock(void)
+{
+	if (!lock)
+		return;
+	mnt_unlock_file(lock);
+	mnt_free_lock(lock);
+}
+
+static void __attribute__((__noreturn__)) sig_handler(int sig)
+{
+	errx(EXIT_FAILURE, "\n%d: catch signal: %s\n", getpid(), strsignal(sig));
+}
+
+static int test_lock(struct libmnt_test *ts, int argc, char *argv[])
+{
+	time_t synctime = 0;
+	unsigned int usecs;
+	const char *datafile = NULL;
+	int verbose = 0, loops = 0, l, idx = 1;
+
+	if (argc < 3)
+		return -EINVAL;
+
+	if (strcmp(argv[idx], "--synctime") == 0) {
+		synctime = (time_t) atol(argv[idx + 1]);
+		idx += 2;
+	}
+	if (idx < argc && strcmp(argv[idx], "--verbose") == 0) {
+		verbose = 1;
+		idx++;
+	}
+
+	if (idx < argc)
+		datafile = argv[idx++];
+	if (idx < argc)
+		loops = atoi(argv[idx++]);
+
+	if (!datafile || !loops)
+		return -EINVAL;
+
+	if (verbose)
+		fprintf(stderr, "%d: start: synctime=%u, datafile=%s, loops=%d\n",
+			 getpid(), (int) synctime, datafile, loops);
+
+	atexit(clean_lock);
+
+	/* be paranoid and call exit() (=clean_lock()) for all signals */
+	{
+		int sig = 0;
+		struct sigaction sa;
+
+		sa.sa_handler = sig_handler;
+		sa.sa_flags = 0;
+		sigfillset(&sa.sa_mask);
+
+		while (sigismember(&sa.sa_mask, ++sig) != -1 && sig != SIGCHLD)
+			sigaction (sig, &sa, (struct sigaction *) 0);
+	}
+
+	/* start the test in exactly defined time */
+	if (synctime) {
+		struct timeval tv;
+
+		gettimeofday(&tv, NULL);
+		if (synctime && synctime - tv.tv_sec > 1) {
+			usecs = ((synctime - tv.tv_sec) * 1000000UL) -
+						(1000000UL - tv.tv_usec);
+			xusleep(usecs);
+		}
+	}
+
+	for (l = 0; l < loops; l++) {
+		lock = mnt_new_lock(datafile, 0);
+		if (!lock)
+			return -1;
+
+		if (mnt_lock_file(lock) != 0) {
+			fprintf(stderr, "%d: failed to lock %s file\n",
+					getpid(), datafile);
+			return -1;
+		}
+
+		increment_data(datafile, verbose, l);
+
+		mnt_unlock_file(lock);
+		mnt_free_lock(lock);
+		lock = NULL;
+
+		/* The mount command usually finishes after a mtab update. We
+		 * simulate this via short sleep -- it's also enough to make
+		 * concurrent processes happy.
+		 */
+		if (synctime)
+			xusleep(25000);
+	}
+
+	return 0;
+}
+
+/*
+ * Note that this test should be executed from a script that creates many
+ * parallel processes, otherwise this test does not make sense.
+ */
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+	{ "--lock", test_lock,  " [--synctime <time_t>] [--verbose] <datafile> <loops> "
+				"increment a number in datafile" },
+	{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/monitor.c b/libmount/src/monitor.c
new file mode 100644
index 0000000..dada02e
--- /dev/null
+++ b/libmount/src/monitor.c
@@ -0,0 +1,980 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2014-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: monitor
+ * @title: Monitor
+ * @short_description: interface to monitor mount tables
+ *
+ * For example monitor VFS (/proc/self/mountinfo) for changes:
+ *
+ * <informalexample>
+ *   <programlisting>
+ * const char *filename;
+ * struct libmount_monitor *mn = mnt_new_monitor();
+ *
+ * mnt_monitor_enable_kernel(mn, TRUE));
+ *
+ * printf("waiting for changes...\n");
+ * while (mnt_monitor_wait(mn, -1) > 0) {
+ *    while (mnt_monitor_next_change(mn, &filename, NULL) == 0)
+ *       printf(" %s: change detected\n", filename);
+ * }
+ * mnt_unref_monitor(mn);
+ *   </programlisting>
+ * </informalexample>
+ *
+ */
+
+#include "fileutils.h"
+#include "mountP.h"
+#include "pathnames.h"
+
+#include <sys/inotify.h>
+#include <sys/epoll.h>
+
+
+struct monitor_opers;
+
+struct monitor_entry {
+	int			fd;		/* private entry file descriptor */
+	char			*path;		/* path to the monitored file */
+	int			type;		/* MNT_MONITOR_TYPE_* */
+	uint32_t		events;		/* wanted epoll events */
+
+	const struct monitor_opers *opers;
+
+	unsigned int		enable : 1,
+				changed : 1;
+
+	struct list_head	ents;
+};
+
+struct libmnt_monitor {
+	int			refcount;
+	int			fd;		/* public monitor file descriptor */
+
+	struct list_head	ents;
+};
+
+struct monitor_opers {
+	int (*op_get_fd)(struct libmnt_monitor *, struct monitor_entry *);
+	int (*op_close_fd)(struct libmnt_monitor *, struct monitor_entry *);
+	int (*op_event_verify)(struct libmnt_monitor *, struct monitor_entry *);
+};
+
+static int monitor_modify_epoll(struct libmnt_monitor *mn,
+				struct monitor_entry *me, int enable);
+
+/**
+ * mnt_new_monitor:
+ *
+ * The initial refcount is 1, and needs to be decremented to
+ * release the resources of the filesystem.
+ *
+ * Returns: newly allocated struct libmnt_monitor.
+ */
+struct libmnt_monitor *mnt_new_monitor(void)
+{
+	struct libmnt_monitor *mn = calloc(1, sizeof(*mn));
+	if (!mn)
+		return NULL;
+
+	mn->refcount = 1;
+	mn->fd = -1;
+	INIT_LIST_HEAD(&mn->ents);
+
+	DBG(MONITOR, ul_debugobj(mn, "alloc"));
+	return mn;
+}
+
+/**
+ * mnt_ref_monitor:
+ * @mn: monitor pointer
+ *
+ * Increments reference counter.
+ */
+void mnt_ref_monitor(struct libmnt_monitor *mn)
+{
+	if (mn)
+		mn->refcount++;
+}
+
+static void free_monitor_entry(struct monitor_entry *me)
+{
+	if (!me)
+		return;
+	list_del(&me->ents);
+	if (me->fd >= 0)
+		close(me->fd);
+	free(me->path);
+	free(me);
+}
+
+/**
+ * mnt_unref_monitor:
+ * @mn: monitor pointer
+ *
+ * Decrements the reference counter, on zero the @mn is automatically
+ * deallocated.
+ */
+void mnt_unref_monitor(struct libmnt_monitor *mn)
+{
+	if (!mn)
+		return;
+
+	mn->refcount--;
+	if (mn->refcount <= 0) {
+		mnt_monitor_close_fd(mn);	/* destroys all file descriptors */
+
+		while (!list_empty(&mn->ents)) {
+			struct monitor_entry *me = list_entry(mn->ents.next,
+						  struct monitor_entry, ents);
+			free_monitor_entry(me);
+		}
+
+		free(mn);
+	}
+}
+
+static struct monitor_entry *monitor_new_entry(struct libmnt_monitor *mn)
+{
+	struct monitor_entry *me;
+
+	assert(mn);
+
+	me = calloc(1, sizeof(*me));
+	if (!me)
+		return NULL;
+        INIT_LIST_HEAD(&me->ents);
+	list_add_tail(&me->ents, &mn->ents);
+
+	me->fd = -1;
+
+	return me;
+}
+
+static int monitor_next_entry(struct libmnt_monitor *mn,
+			      struct libmnt_iter *itr,
+			      struct monitor_entry **me)
+{
+	int rc = 1;
+
+	assert(mn);
+	assert(itr);
+	assert(me);
+
+	*me = NULL;
+
+	if (!itr->head)
+		MNT_ITER_INIT(itr, &mn->ents);
+	if (itr->p != itr->head) {
+		MNT_ITER_ITERATE(itr, *me, struct monitor_entry, ents);
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/* returns entry by type */
+static struct monitor_entry *monitor_get_entry(struct libmnt_monitor *mn, int type)
+{
+	struct libmnt_iter itr;
+	struct monitor_entry *me;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while (monitor_next_entry(mn, &itr, &me) == 0) {
+		if (me->type == type)
+			return me;
+	}
+	return NULL;
+}
+
+
+/*
+ * Userspace monitor
+ */
+
+static int userspace_monitor_close_fd(struct libmnt_monitor *mn __attribute__((__unused__)),
+				    struct monitor_entry *me)
+{
+	assert(me);
+
+	if (me->fd >= 0)
+		close(me->fd);
+	me->fd = -1;
+	return 0;
+}
+
+static int userspace_add_watch(struct monitor_entry *me, int *final, int *fd)
+{
+	char *filename = NULL;
+	int wd, rc = -EINVAL;
+
+	assert(me);
+	assert(me->path);
+
+	/*
+	 * libmount uses rename(2) to atomically update utab, monitor
+	 * rename changes is too tricky. It seems better to monitor utab
+	 * lockfile close.
+	 */
+	if (asprintf(&filename, "%s.lock", me->path) <= 0) {
+		rc = -errno;
+		goto done;
+	}
+
+	/* try lock file if already exists */
+	errno = 0;
+	wd = inotify_add_watch(me->fd, filename, IN_CLOSE_NOWRITE);
+	if (wd >= 0) {
+		DBG(MONITOR, ul_debug(" added inotify watch for %s [fd=%d]", filename, wd));
+		rc = 0;
+		if (final)
+			*final = 1;
+		if (fd)
+			*fd = wd;
+		goto done;
+	} else if (errno != ENOENT) {
+		rc = -errno;
+		goto done;
+	}
+
+	while (strchr(filename, '/')) {
+		stripoff_last_component(filename);
+		if (!*filename)
+			break;
+
+		/* try directory where is the lock file */
+		errno = 0;
+		wd = inotify_add_watch(me->fd, filename, IN_CREATE|IN_ISDIR);
+		if (wd >= 0) {
+			DBG(MONITOR, ul_debug(" added inotify watch for %s [fd=%d]", filename, wd));
+			rc = 0;
+			if (fd)
+				*fd = wd;
+			break;
+		}
+
+		if (errno != ENOENT) {
+			rc = -errno;
+			break;
+		}
+	}
+done:
+	free(filename);
+	return rc;
+}
+
+static int userspace_monitor_get_fd(struct libmnt_monitor *mn,
+				    struct monitor_entry *me)
+{
+	int rc;
+
+	if (!me || me->enable == 0)	/* not-initialized or disabled */
+		return -EINVAL;
+	if (me->fd >= 0)
+		return me->fd;		/* already initialized */
+
+	assert(me->path);
+	DBG(MONITOR, ul_debugobj(mn, " open userspace monitor for %s", me->path));
+
+	me->fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
+	if (me->fd < 0)
+		goto err;
+
+	if (userspace_add_watch(me, NULL, NULL) < 0)
+		goto err;
+
+	return me->fd;
+err:
+	rc = -errno;
+	if (me->fd >= 0)
+		close(me->fd);
+	me->fd = -1;
+	DBG(MONITOR, ul_debugobj(mn, "failed to create userspace monitor [rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * verify and drain inotify buffer
+ */
+static int userspace_event_verify(struct libmnt_monitor *mn,
+					struct monitor_entry *me)
+{
+	char buf[sizeof(struct inotify_event) + NAME_MAX + 1];
+	int status = 0;
+
+	if (!me || me->fd < 0)
+		return 0;
+
+	DBG(MONITOR, ul_debugobj(mn, "drain and verify userspace monitor inotify"));
+
+	/* the me->fd is non-blocking */
+	do {
+		ssize_t len;
+		char *p;
+		const struct inotify_event *e;
+
+		len = read(me->fd, buf, sizeof(buf));
+		if (len < 0)
+			break;
+
+		for (p = buf; p < buf + len;
+		     p += sizeof(struct inotify_event) + e->len) {
+
+			int fd = -1;
+
+			e = (const struct inotify_event *) p;
+			DBG(MONITOR, ul_debugobj(mn, " inotify event 0x%x [%s]\n", e->mask, e->len ? e->name : ""));
+
+			if (e->mask & IN_CLOSE_NOWRITE)
+				status = 1;
+			else {
+				/* event on lock file */
+				userspace_add_watch(me, &status, &fd);
+
+				if (fd != e->wd) {
+					DBG(MONITOR, ul_debugobj(mn, " removing watch [fd=%d]", e->wd));
+					inotify_rm_watch(me->fd, e->wd);
+				}
+			}
+		}
+	} while (1);
+
+	DBG(MONITOR, ul_debugobj(mn, "%s", status == 1 ? " success" : " nothing"));
+	return status;
+}
+
+/*
+ * userspace monitor operations
+ */
+static const struct monitor_opers userspace_opers = {
+	.op_get_fd		= userspace_monitor_get_fd,
+	.op_close_fd		= userspace_monitor_close_fd,
+	.op_event_verify	= userspace_event_verify
+};
+
+/**
+ * mnt_monitor_enable_userspace:
+ * @mn: monitor
+ * @enable: 0 or 1
+ * @filename: overwrites default
+ *
+ * Enables or disables userspace monitoring. If the userspace monitor does not
+ * exist and enable=1 then allocates new resources necessary for the monitor.
+ *
+ * If the top-level monitor has been already created (by mnt_monitor_get_fd()
+ * or mnt_monitor_wait()) then it's updated according to @enable.
+ *
+ * The @filename is used only the first time when you enable the monitor. It's
+ * impossible to have more than one userspace monitor. The recommended is to
+ * use NULL as filename.
+ *
+ * The userspace monitor is unsupported for systems with classic regular
+ * /etc/mtab file.
+ *
+ * Return: 0 on success and <0 on error
+ */
+int mnt_monitor_enable_userspace(struct libmnt_monitor *mn, int enable, const char *filename)
+{
+	struct monitor_entry *me;
+	int rc = 0;
+
+	if (!mn)
+		return -EINVAL;
+
+	me = monitor_get_entry(mn, MNT_MONITOR_TYPE_USERSPACE);
+	if (me) {
+		rc = monitor_modify_epoll(mn, me, enable);
+		if (!enable)
+			userspace_monitor_close_fd(mn, me);
+		return rc;
+	}
+	if (!enable)
+		return 0;
+
+	DBG(MONITOR, ul_debugobj(mn, "allocate new userspace monitor"));
+
+	if (!filename)
+		filename = mnt_get_utab_path();		/* /run/mount/utab */
+	if (!filename) {
+		DBG(MONITOR, ul_debugobj(mn, "failed to get userspace mount table path"));
+		return -EINVAL;
+	}
+
+	me = monitor_new_entry(mn);
+	if (!me)
+		goto err;
+
+	me->type = MNT_MONITOR_TYPE_USERSPACE;
+	me->opers = &userspace_opers;
+	me->events = EPOLLIN;
+	me->path = strdup(filename);
+	if (!me->path)
+		goto err;
+
+	return monitor_modify_epoll(mn, me, TRUE);
+err:
+	rc = -errno;
+	free_monitor_entry(me);
+	DBG(MONITOR, ul_debugobj(mn, "failed to allocate userspace monitor [rc=%d]", rc));
+	return rc;
+}
+
+
+/*
+ * Kernel monitor
+ */
+
+static int kernel_monitor_close_fd(struct libmnt_monitor *mn __attribute__((__unused__)),
+				   struct monitor_entry *me)
+{
+	assert(me);
+
+	if (me->fd >= 0)
+		close(me->fd);
+	me->fd = -1;
+	return 0;
+}
+
+static int kernel_monitor_get_fd(struct libmnt_monitor *mn,
+				 struct monitor_entry *me)
+{
+	int rc;
+
+	if (!me || me->enable == 0)	/* not-initialized or disabled */
+		return -EINVAL;
+	if (me->fd >= 0)
+		return me->fd;		/* already initialized */
+
+	assert(me->path);
+	DBG(MONITOR, ul_debugobj(mn, " open kernel monitor for %s", me->path));
+
+	me->fd = open(me->path, O_RDONLY|O_CLOEXEC);
+	if (me->fd < 0)
+		goto err;
+
+	return me->fd;
+err:
+	rc = -errno;
+	DBG(MONITOR, ul_debugobj(mn, "failed to create kernel  monitor [rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * kernel monitor operations
+ */
+static const struct monitor_opers kernel_opers = {
+	.op_get_fd		= kernel_monitor_get_fd,
+	.op_close_fd		= kernel_monitor_close_fd,
+};
+
+/**
+ * mnt_monitor_enable_kernel:
+ * @mn: monitor
+ * @enable: 0 or 1
+ *
+ * Enables or disables kernel VFS monitoring. If the monitor does not exist and
+ * enable=1 then allocates new resources necessary for the monitor.
+ *
+ * If the top-level monitor has been already created (by mnt_monitor_get_fd()
+ * or mnt_monitor_wait()) then it's updated according to @enable.
+ *
+ * Return: 0 on success and <0 on error
+ */
+int mnt_monitor_enable_kernel(struct libmnt_monitor *mn, int enable)
+{
+	struct monitor_entry *me;
+	int rc = 0;
+
+	if (!mn)
+		return -EINVAL;
+
+	me = monitor_get_entry(mn, MNT_MONITOR_TYPE_KERNEL);
+	if (me) {
+		rc = monitor_modify_epoll(mn, me, enable);
+		if (!enable)
+			kernel_monitor_close_fd(mn, me);
+		return rc;
+	}
+	if (!enable)
+		return 0;
+
+	DBG(MONITOR, ul_debugobj(mn, "allocate new kernel monitor"));
+
+	/* create a new entry */
+	me = monitor_new_entry(mn);
+	if (!me)
+		goto err;
+
+	/* If you want to use epoll FD in another epoll then top level
+	 * epoll_wait() will drain all events from low-level FD if the
+	 * low-level FD is not added with EPOLLIN. It means without EPOLLIN it
+	 * it's impossible to detect which low-level FD has been active.
+	 *
+	 * Unfortunately, use EPOLLIN for mountinfo is tricky because in this
+	 * case kernel returns events all time (we don't read from the FD).
+	 * The solution is to use also edge-triggered (EPOLLET) flag, then
+	 * kernel generate events on mountinfo changes only. The disadvantage is
+	 * that we have to drain initial event generated by EPOLLIN after
+	 * epoll_ctl(ADD). See monitor_modify_epoll().
+	 */
+	me->events = EPOLLIN | EPOLLET;
+
+	me->type = MNT_MONITOR_TYPE_KERNEL;
+	me->opers = &kernel_opers;
+	me->path = strdup(_PATH_PROC_MOUNTINFO);
+	if (!me->path)
+		goto err;
+
+	return monitor_modify_epoll(mn, me, TRUE);
+err:
+	rc = -errno;
+	free_monitor_entry(me);
+	DBG(MONITOR, ul_debugobj(mn, "failed to allocate kernel monitor [rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * Add/Remove monitor entry to/from monitor epoll.
+ */
+static int monitor_modify_epoll(struct libmnt_monitor *mn,
+				struct monitor_entry *me, int enable)
+{
+	assert(mn);
+	assert(me);
+
+	me->enable = enable ? 1 : 0;
+	me->changed = 0;
+
+	if (mn->fd < 0)
+		return 0;	/* no epoll, ignore request */
+
+	if (enable) {
+		struct epoll_event ev = { .events = me->events };
+		int fd = me->opers->op_get_fd(mn, me);
+
+		if (fd < 0)
+			goto err;
+
+		DBG(MONITOR, ul_debugobj(mn, " add fd=%d (for %s)", fd, me->path));
+
+		ev.data.ptr = (void *) me;
+
+		if (epoll_ctl(mn->fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
+			if (errno != EEXIST)
+				goto err;
+		}
+		if (me->events & (EPOLLIN | EPOLLET)) {
+			/* Drain initial events generated for /proc/self/mountinfo */
+			struct epoll_event events[1];
+			while (epoll_wait(mn->fd, events, 1, 0) > 0);
+		}
+	} else if (me->fd) {
+		DBG(MONITOR, ul_debugobj(mn, " remove fd=%d (for %s)", me->fd, me->path));
+		if (epoll_ctl(mn->fd, EPOLL_CTL_DEL, me->fd, NULL) < 0) {
+			if (errno != ENOENT)
+				goto err;
+		}
+	}
+
+	return 0;
+err:
+	return -errno;
+}
+
+/**
+ * mnt_monitor_close_fd:
+ * @mn: monitor
+ *
+ * Close monitor file descriptor. This is usually unnecessary, because
+ * mnt_unref_monitor() cleanups all.
+ *
+ * The function is necessary only if you want to reset monitor setting. The
+ * next mnt_monitor_get_fd() or mnt_monitor_wait() will use newly initialized
+ * monitor.  This restart is unnecessary for mnt_monitor_enable_*() functions.
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int mnt_monitor_close_fd(struct libmnt_monitor *mn)
+{
+	struct libmnt_iter itr;
+	struct monitor_entry *me;
+
+	if (!mn)
+		return -EINVAL;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	/* disable all monitor entries */
+	while (monitor_next_entry(mn, &itr, &me) == 0) {
+
+		/* remove entry from epoll */
+		if (mn->fd >= 0)
+			monitor_modify_epoll(mn, me, FALSE);
+
+		/* close entry FD */
+		me->opers->op_close_fd(mn, me);
+	}
+
+	if (mn->fd >= 0) {
+		DBG(MONITOR, ul_debugobj(mn, "closing top-level monitor fd"));
+		close(mn->fd);
+	}
+	mn->fd = -1;
+	return 0;
+}
+
+/**
+ * mnt_monitor_get_fd:
+ * @mn: monitor
+ *
+ * The file descriptor is associated with all monitored files and it's usable
+ * for example for epoll. You have to call mnt_monitor_event_cleanup() or
+ * mnt_monitor_next_change() after each event.
+ *
+ * Returns: >=0 (fd) on success, <0 on error
+ */
+int mnt_monitor_get_fd(struct libmnt_monitor *mn)
+{
+	struct libmnt_iter itr;
+	struct monitor_entry *me;
+	int rc = 0;
+
+	if (!mn)
+		return -EINVAL;
+	if (mn->fd >= 0)
+		return mn->fd;
+
+	DBG(MONITOR, ul_debugobj(mn, "create top-level monitor fd"));
+	mn->fd = epoll_create1(EPOLL_CLOEXEC);
+	if (mn->fd < 0)
+		return -errno;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	DBG(MONITOR, ul_debugobj(mn, "adding monitor entries to epoll (fd=%d)", mn->fd));
+	while (monitor_next_entry(mn, &itr, &me) == 0) {
+		if (!me->enable)
+			continue;
+		rc = monitor_modify_epoll(mn, me, TRUE);
+		if (rc)
+			goto err;
+	}
+
+	DBG(MONITOR, ul_debugobj(mn, "successfully created monitor"));
+	return mn->fd;
+err:
+	rc = errno ? -errno : -EINVAL;
+	close(mn->fd);
+	mn->fd = -1;
+	DBG(MONITOR, ul_debugobj(mn, "failed to create monitor [rc=%d]", rc));
+	return rc;
+}
+
+/**
+ * mnt_monitor_wait:
+ * @mn: monitor
+ * @timeout: number of milliseconds, -1 block indefinitely, 0 return immediately
+ *
+ * Waits for the next change, after the event it's recommended to use
+ * mnt_monitor_next_change() to get more details about the change and to
+ * avoid false positive events.
+ *
+ * Returns: 1 success (something changed), 0 timeout, <0 error.
+ */
+int mnt_monitor_wait(struct libmnt_monitor *mn, int timeout)
+{
+	int rc;
+	struct monitor_entry *me;
+	struct epoll_event events[1];
+
+	if (!mn)
+		return -EINVAL;
+
+	if (mn->fd < 0) {
+		rc = mnt_monitor_get_fd(mn);
+		if (rc < 0)
+			return rc;
+	}
+
+	do {
+		DBG(MONITOR, ul_debugobj(mn, "calling epoll_wait(), timeout=%d", timeout));
+		rc = epoll_wait(mn->fd, events, 1, timeout);
+		if (rc < 0)
+			return -errno;		/* error */
+		if (rc == 0)
+			return 0;		/* timeout */
+
+		me = (struct monitor_entry *) events[0].data.ptr;
+		if (!me)
+			return -EINVAL;
+
+		if (me->opers->op_event_verify == NULL ||
+		    me->opers->op_event_verify(mn, me) == 1) {
+			me->changed = 1;
+			break;
+		}
+	} while (1);
+
+	return 1;			/* success */
+}
+
+
+static struct monitor_entry *get_changed(struct libmnt_monitor *mn)
+{
+	struct libmnt_iter itr;
+	struct monitor_entry *me;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while (monitor_next_entry(mn, &itr, &me) == 0) {
+		if (me->changed)
+			return me;
+	}
+	return NULL;
+}
+
+/**
+ * mnt_monitor_next_change:
+ * @mn: monitor
+ * @filename: returns changed file (optional argument)
+ * @type: returns MNT_MONITOR_TYPE_* (optional argument)
+ *
+ * The function does not wait and it's designed to provide details about changes.
+ * It's always recommended to use this function to avoid false positives.
+ *
+ * Returns: 0 on success, 1 no change, <0 on error
+ */
+int mnt_monitor_next_change(struct libmnt_monitor *mn,
+			     const char **filename,
+			     int *type)
+{
+	int rc;
+	struct monitor_entry *me;
+
+	if (!mn || mn->fd < 0)
+		return -EINVAL;
+
+	/*
+	 * if we previously called epoll_wait() (e.g. mnt_monitor_wait()) then
+	 * info about unread change is already stored in monitor_entry.
+	 *
+	 * If we get nothing, then ask kernel.
+	 */
+	me = get_changed(mn);
+	while (!me) {
+		struct epoll_event events[1];
+
+		DBG(MONITOR, ul_debugobj(mn, "asking for next changed"));
+
+		rc = epoll_wait(mn->fd, events, 1, 0);	/* no timeout! */
+		if (rc < 0) {
+			DBG(MONITOR, ul_debugobj(mn, " *** error"));
+			return -errno;
+		}
+		if (rc == 0) {
+			DBG(MONITOR, ul_debugobj(mn, " *** nothing"));
+			return 1;
+		}
+
+		me = (struct monitor_entry *) events[0].data.ptr;
+		if (!me)
+			return -EINVAL;
+
+		if (me->opers->op_event_verify != NULL &&
+		    me->opers->op_event_verify(mn, me) != 1)
+			me = NULL;
+	}
+
+	me->changed = 0;
+
+	if (filename)
+		*filename = me->path;
+	if (type)
+		*type = me->type;
+
+	DBG(MONITOR, ul_debugobj(mn, " *** success [changed: %s]", me->path));
+	return 0;
+}
+
+/**
+ * mnt_monitor_event_cleanup:
+ * @mn: monitor
+ *
+ * This function cleanups (drain) internal buffers. It's necessary to call
+ * this function after event if you do not call mnt_monitor_next_change().
+ *
+ * Returns: 0 on success, <0 on error
+ */
+int mnt_monitor_event_cleanup(struct libmnt_monitor *mn)
+{
+	int rc;
+
+	if (!mn || mn->fd < 0)
+		return -EINVAL;
+
+	while ((rc = mnt_monitor_next_change(mn, NULL, NULL)) == 0);
+	return rc < 0 ? rc : 0;
+}
+
+#ifdef TEST_PROGRAM
+
+static struct libmnt_monitor *create_test_monitor(int argc, char *argv[])
+{
+	struct libmnt_monitor *mn;
+	int i;
+
+	mn = mnt_new_monitor();
+	if (!mn) {
+		warn("failed to allocate monitor");
+		goto err;
+	}
+
+	for (i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "userspace") == 0) {
+			if (mnt_monitor_enable_userspace(mn, TRUE, NULL)) {
+				warn("failed to initialize userspace monitor");
+				goto err;
+			}
+
+		} else if (strcmp(argv[i], "kernel") == 0) {
+			if (mnt_monitor_enable_kernel(mn, TRUE)) {
+				warn("failed to initialize kernel monitor");
+				goto err;
+			}
+		}
+	}
+	if (i == 1) {
+		warnx("No monitor type specified");
+		goto err;
+	}
+
+	return mn;
+err:
+	mnt_unref_monitor(mn);
+	return NULL;
+}
+
+/*
+ * create a monitor and add the monitor fd to epoll
+ */
+static int __test_epoll(struct libmnt_test *ts, int argc, char *argv[], int cleanup)
+{
+	int fd, efd = -1, rc = -1;
+	struct epoll_event ev;
+	struct libmnt_monitor *mn = create_test_monitor(argc, argv);
+
+	if (!mn)
+		return -1;
+
+	fd = mnt_monitor_get_fd(mn);
+	if (fd < 0) {
+		warn("failed to initialize monitor fd");
+		goto done;
+	}
+
+	efd = epoll_create1(EPOLL_CLOEXEC);
+	if (efd < 0) {
+		warn("failed to create epoll");
+		goto done;
+	}
+
+	ev.events = EPOLLIN;
+	ev.data.fd = fd;
+
+	rc = epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev);
+	if (rc < 0) {
+		warn("failed to add fd to epoll");
+		goto done;
+	}
+
+	printf("waiting for changes...\n");
+	do {
+		const char *filename = NULL;
+		struct epoll_event events[1];
+		int n = epoll_wait(efd, events, 1, -1);
+
+		if (n < 0) {
+			rc = -errno;
+			warn("polling error");
+			goto done;
+		}
+		if (n == 0 || events[0].data.fd != fd)
+			continue;
+
+		printf(" top-level FD active\n");
+		if (cleanup)
+			mnt_monitor_event_cleanup(mn);
+		else {
+			while (mnt_monitor_next_change(mn, &filename, NULL) == 0)
+				printf("  %s: change detected\n", filename);
+		}
+	} while (1);
+
+	rc = 0;
+done:
+	if (efd >= 0)
+		close(efd);
+	mnt_unref_monitor(mn);
+	return rc;
+}
+
+/*
+ * create a monitor and add the monitor fd to epoll
+ */
+static int test_epoll(struct libmnt_test *ts, int argc, char *argv[])
+{
+	return __test_epoll(ts, argc, argv, 0);
+}
+
+static int test_epoll_cleanup(struct libmnt_test *ts, int argc, char *argv[])
+{
+	return __test_epoll(ts, argc, argv, 1);
+}
+
+/*
+ * create a monitor and wait for a change
+ */
+static int test_wait(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *filename;
+	struct libmnt_monitor *mn = create_test_monitor(argc, argv);
+
+	if (!mn)
+		return -1;
+
+	printf("waiting for changes...\n");
+	while (mnt_monitor_wait(mn, -1) > 0) {
+		printf("notification detected\n");
+
+		while (mnt_monitor_next_change(mn, &filename, NULL) == 0)
+			printf(" %s: change detected\n", filename);
+
+	}
+	mnt_unref_monitor(mn);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+		{ "--epoll", test_epoll, "<userspace kernel ...>  monitor in epoll" },
+		{ "--epoll-clean", test_epoll_cleanup, "<userspace kernel ...>  monitor in epoll and clean events" },
+		{ "--wait",  test_wait,  "<userspace kernel ...>  monitor wait function" },
+		{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
new file mode 100644
index 0000000..d8ba0ab
--- /dev/null
+++ b/libmount/src/mountP.h
@@ -0,0 +1,485 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * mountP.h - private library header file
+ *
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef _LIBMOUNT_PRIVATE_H
+#define _LIBMOUNT_PRIVATE_H
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/vfs.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "c.h"
+#include "list.h"
+#include "debug.h"
+#include "libmount.h"
+
+/*
+ * Debug
+ */
+#define MNT_DEBUG_HELP		(1 << 0)
+#define MNT_DEBUG_INIT		(1 << 1)
+#define MNT_DEBUG_CACHE		(1 << 2)
+#define MNT_DEBUG_OPTIONS	(1 << 3)
+#define MNT_DEBUG_LOCKS		(1 << 4)
+#define MNT_DEBUG_TAB		(1 << 5)
+#define MNT_DEBUG_FS		(1 << 6)
+#define MNT_DEBUG_UPDATE	(1 << 7)
+#define MNT_DEBUG_UTILS		(1 << 8)
+#define MNT_DEBUG_CXT		(1 << 9)
+#define MNT_DEBUG_DIFF		(1 << 10)
+#define MNT_DEBUG_MONITOR	(1 << 11)
+#define MNT_DEBUG_BTRFS		(1 << 12)
+#define MNT_DEBUG_LOOP		(1 << 13)
+#define MNT_DEBUG_VERITY	(1 << 14)
+
+#define MNT_DEBUG_ALL		0xFFFF
+
+UL_DEBUG_DECLARE_MASK(libmount);
+#define DBG(m, x)	__UL_DBG(libmount, MNT_DEBUG_, m, x)
+#define ON_DBG(m, x)	__UL_DBG_CALL(libmount, MNT_DEBUG_, m, x)
+#define DBG_FLUSH	__UL_DBG_FLUSH(libmount, MNT_DEBUG_)
+
+#define UL_DEBUG_CURRENT_MASK	UL_DEBUG_MASK(libmount)
+#include "debugobj.h"
+
+/*
+ * NLS -- the library has to be independent on main program, so define
+ * UL_TEXTDOMAIN_EXPLICIT before you include nls.h.
+ *
+ * Now we use util-linux.po (=PACKAGE), rather than maintain the texts
+ * in the separate libmount.po file.
+ */
+#define LIBMOUNT_TEXTDOMAIN	PACKAGE
+#define UL_TEXTDOMAIN_EXPLICIT	LIBMOUNT_TEXTDOMAIN
+#include "nls.h"
+
+
+/* extension for files in the directory */
+#define MNT_MNTTABDIR_EXT	".fstab"
+
+/* library private paths */
+#define MNT_RUNTIME_TOPDIR	"/run"
+#define MNT_RUNTIME_TOPDIR_OLD	"/dev"
+
+#define MNT_PATH_UTAB		MNT_RUNTIME_TOPDIR "/mount/utab"
+#define MNT_PATH_UTAB_OLD	MNT_RUNTIME_TOPDIR_OLD "/.mount/utab"
+
+#define MNT_UTAB_HEADER	"# libmount utab file\n"
+
+#ifdef TEST_PROGRAM
+struct libmnt_test {
+	const char	*name;
+	int		(*body)(struct libmnt_test *ts, int argc, char *argv[]);
+	const char	*usage;
+};
+
+/* test.c */
+extern int mnt_run_test(struct libmnt_test *tests, int argc, char *argv[]);
+#endif
+
+/* utils.c */
+extern int mnt_valid_tagname(const char *tagname);
+extern int append_string(char **a, const char *b);
+
+extern const char *mnt_statfs_get_fstype(struct statfs *vfs);
+extern int is_procfs_fd(int fd);
+extern int is_file_empty(const char *name);
+
+extern int mnt_is_readonly(const char *path)
+			__attribute__((nonnull));
+
+extern int mnt_parse_offset(const char *str, size_t len, uintmax_t *res);
+
+extern int mnt_chdir_to_parent(const char *target, char **filename);
+
+extern char *mnt_get_username(const uid_t uid);
+extern int mnt_get_uid(const char *username, uid_t *uid);
+extern int mnt_get_gid(const char *groupname, gid_t *gid);
+extern int mnt_in_group(gid_t gid);
+
+extern int mnt_open_uniq_filename(const char *filename, char **name);
+
+extern int mnt_has_regular_utab(const char **utab, int *writable);
+extern const char *mnt_get_utab_path(void);
+
+extern int mnt_get_filesystems(char ***filesystems, const char *pattern);
+extern void mnt_free_filesystems(char **filesystems);
+
+extern char *mnt_get_kernel_cmdline_option(const char *name);
+extern int mnt_stat_mountpoint(const char *target, struct stat *st);
+extern int mnt_lstat_mountpoint(const char *target, struct stat *st);
+extern FILE *mnt_get_procfs_memstream(int fd, char **membuf);
+
+/* tab.c */
+extern int is_mountinfo(struct libmnt_table *tb);
+extern int mnt_table_set_parser_fltrcb(	struct libmnt_table *tb,
+					int (*cb)(struct libmnt_fs *, void *),
+					void *data);
+
+extern int __mnt_table_parse_mtab(struct libmnt_table *tb,
+					const char *filename,
+					struct libmnt_table *u_tb);
+
+extern struct libmnt_fs *mnt_table_get_fs_root(struct libmnt_table *tb,
+					struct libmnt_fs *fs,
+					unsigned long mountflags,
+					char **fsroot);
+
+extern int __mnt_table_is_fs_mounted(	struct libmnt_table *tb,
+					struct libmnt_fs *fstab_fs,
+					const char *tgt_prefix);
+
+/*
+ * Generic iterator
+ */
+struct libmnt_iter {
+        struct list_head        *p;		/* current position */
+        struct list_head        *head;		/* start position */
+	int			direction;	/* MNT_ITER_{FOR,BACK}WARD */
+};
+
+#define IS_ITER_FORWARD(_i)	((_i)->direction == MNT_ITER_FORWARD)
+#define IS_ITER_BACKWARD(_i)	((_i)->direction == MNT_ITER_BACKWARD)
+
+#define MNT_ITER_INIT(itr, list) \
+	do { \
+		(itr)->p = IS_ITER_FORWARD(itr) ? \
+				(list)->next : (list)->prev; \
+		(itr)->head = (list); \
+	} while(0)
+
+#define MNT_ITER_ITERATE(itr, res, restype, member) \
+	do { \
+		res = list_entry((itr)->p, restype, member); \
+		(itr)->p = IS_ITER_FORWARD(itr) ? \
+				(itr)->p->next : (itr)->p->prev; \
+	} while(0)
+
+
+/*
+ * This struct represents one entry in a mtab/fstab/mountinfo file.
+ * (note that fstab[1] means the first column from fstab, and so on...)
+ */
+struct libmnt_fs {
+	struct list_head ents;
+	struct libmnt_table *tab;
+
+	int		refcount;	/* reference counter */
+	int		id;		/* mountinfo[1]: ID */
+	int		parent;		/* mountinfo[2]: parent */
+	dev_t		devno;		/* mountinfo[3]: st_dev */
+
+	char		*bindsrc;	/* utab, full path from fstab[1] for bind mounts */
+
+	char		*source;	/* fstab[1], mountinfo[10], swaps[1]:
+                                         * source dev, file, dir or TAG */
+	char		*tagname;	/* fstab[1]: tag name - "LABEL", "UUID", ..*/
+	char		*tagval;	/*           tag value */
+
+	char		*root;		/* mountinfo[4]: root of the mount within the FS */
+	char		*target;	/* mountinfo[5], fstab[2]: mountpoint */
+	char		*fstype;	/* mountinfo[9], fstab[3]: filesystem type */
+
+	char		*optstr;	/* fstab[4], merged options */
+	char		*vfs_optstr;	/* mountinfo[6]: fs-independent (VFS) options */
+	char		*opt_fields;	/* mountinfo[7]: optional fields */
+	char		*fs_optstr;	/* mountinfo[11]: fs-dependent options */
+	char		*user_optstr;	/* userspace mount options */
+	char		*attrs;		/* mount attributes */
+
+	int		freq;		/* fstab[5]: dump frequency in days */
+	int		passno;		/* fstab[6]: pass number on parallel fsck */
+
+	/* /proc/swaps */
+	char		*swaptype;	/* swaps[2]: device type (partition, file, ...) */
+	off_t		size;		/* swaps[3]: swaparea size */
+	off_t		usedsize;	/* swaps[4]: used size */
+	int		priority;	/* swaps[5]: swap priority */
+
+	int		flags;		/* MNT_FS_* flags */
+	pid_t		tid;		/* /proc/<tid>/mountinfo otherwise zero */
+
+	char		*comment;	/* fstab comment */
+
+	void		*userdata;	/* library independent data */
+};
+
+/*
+ * fs flags
+ */
+#define MNT_FS_PSEUDO	(1 << 1) /* pseudo filesystem */
+#define MNT_FS_NET	(1 << 2) /* network filesystem */
+#define MNT_FS_SWAP	(1 << 3) /* swap device */
+#define MNT_FS_KERNEL	(1 << 4) /* data from /proc/{mounts,self/mountinfo} */
+#define MNT_FS_MERGED	(1 << 5) /* already merged data from /run/mount/utab */
+
+#define mnt_fs_is_regular(_f)	(!(mnt_fs_is_pseudofs(_f) \
+				   || mnt_fs_is_netfs(_f) \
+				   || mnt_fs_is_swaparea(_f)))
+
+/*
+ * mtab/fstab/mountinfo file
+ */
+struct libmnt_table {
+	int		fmt;		/* MNT_FMT_* file format */
+	int		nents;		/* number of entries */
+	int		refcount;	/* reference counter */
+	int		comms;		/* enable/disable comment parsing */
+	char		*comm_intro;	/* First comment in file */
+	char		*comm_tail;	/* Last comment in file */
+
+	struct libmnt_cache *cache;		/* canonicalized paths/tags cache */
+
+        int		(*errcb)(struct libmnt_table *tb,
+				 const char *filename, int line);
+
+	int		(*fltrcb)(struct libmnt_fs *fs, void *data);
+	void		*fltrcb_data;
+
+
+	struct list_head	ents;	/* list of entries (libmnt_fs) */
+	void		*userdata;
+};
+
+extern struct libmnt_table *__mnt_new_table_from_file(const char *filename, int fmt, int empty_for_enoent);
+
+/*
+ * Tab file format
+ */
+enum {
+	MNT_FMT_GUESS,
+	MNT_FMT_FSTAB,			/* /etc/{fs,m}tab */
+	MNT_FMT_MTAB = MNT_FMT_FSTAB,	/* alias */
+	MNT_FMT_MOUNTINFO,		/* /proc/#/mountinfo */
+	MNT_FMT_UTAB,			/* /run/mount/utab */
+	MNT_FMT_SWAPS			/* /proc/swaps */
+};
+
+/*
+ * Additional mounts
+ */
+struct libmnt_addmount {
+	unsigned long mountflags;
+
+	struct list_head	mounts;
+};
+
+struct libmnt_ns {
+	int fd;				/* file descriptor of namespace, -1 when inactive */
+	struct libmnt_cache *cache;	/* paths cache associated with NS */
+};
+
+/*
+ * Mount context -- high-level API
+ */
+struct libmnt_context
+{
+	int	action;		/* MNT_ACT_{MOUNT,UMOUNT} */
+	int	restricted;	/* root or not? */
+
+	char	*fstype_pattern;	/* for mnt_match_fstype() */
+	char	*optstr_pattern;	/* for mnt_match_options() */
+
+	struct libmnt_fs *fs;		/* filesystem description (type, mountpoint, device, ...) */
+	struct libmnt_fs *fs_template;	/* used for @fs on mnt_reset_context() */
+
+	struct libmnt_table *fstab;	/* fstab (or mtab for some remounts) entries */
+	struct libmnt_table *mtab;	/* mtab entries */
+	struct libmnt_table *utab;	/* rarely used by umount only */
+
+	int	(*table_errcb)(struct libmnt_table *tb,	/* callback for libmnt_table structs */
+			 const char *filename, int line);
+
+	int	(*table_fltrcb)(struct libmnt_fs *fs, void *data);	/* callback for libmnt_table structs */
+	void	*table_fltrcb_data;
+
+	char	*(*pwd_get_cb)(struct libmnt_context *);		/* get encryption password */
+	void	(*pwd_release_cb)(struct libmnt_context *, char *);	/* release password */
+
+	int	optsmode;	/* fstab optstr mode MNT_OPTSMODE_{AUTO,FORCE,IGNORE} */
+	int	loopdev_fd;	/* open loopdev */
+
+	unsigned long	mountflags;	/* final mount(2) flags */
+	const void	*mountdata;	/* final mount(2) data, string or binary data */
+
+	unsigned long	user_mountflags;	/* MNT_MS_* (loop=, user=, ...) */
+
+	struct list_head	addmounts;	/* additional mounts */
+
+	struct libmnt_cache	*cache;	/* paths cache */
+	struct libmnt_lock	*lock;	/* mtab lock */
+	struct libmnt_update	*update;/* mtab/utab update */
+
+	const char	*mtab_path; /* path to mtab */
+	int		mtab_writable; /* is mtab writable */
+
+	const char	*utab_path; /* path to utab */
+	int		utab_writable; /* is utab writable */
+
+	char		*tgt_prefix;	/* path used for all targets */
+
+	int	flags;		/* private context flags */
+
+	char	*helper;	/* name of the used /sbin/[u]mount.<type> helper */
+	int	helper_status;	/* helper wait(2) status */
+	int	helper_exec_status; /* 1: not called yet, 0: success, <0: -errno */
+
+	char	*orig_user;	/* original (non-fixed) user= option */
+
+	pid_t	*children;	/* "mount -a --fork" PIDs */
+	int	nchildren;	/* number of children */
+	pid_t	pid;		/* 0=parent; PID=child */
+
+
+	int	syscall_status;	/* 1: not called yet, 0: success, <0: -errno */
+
+	struct libmnt_ns	ns_orig;	/* original namespace */
+	struct libmnt_ns	ns_tgt;		/* target namespace */
+	struct libmnt_ns	*ns_cur;	/* pointer to current namespace */
+
+	unsigned int	enabled_textdomain : 1;		/* bindtextdomain() called */
+};
+
+/* flags */
+#define MNT_FL_NOMTAB		(1 << 1)
+#define MNT_FL_FAKE		(1 << 2)
+#define MNT_FL_SLOPPY		(1 << 3)
+#define MNT_FL_VERBOSE		(1 << 4)
+#define MNT_FL_NOHELPERS	(1 << 5)
+#define MNT_FL_LOOPDEL		(1 << 6)
+#define MNT_FL_LAZY		(1 << 7)
+#define MNT_FL_FORCE		(1 << 8)
+#define MNT_FL_NOCANONICALIZE	(1 << 9)
+#define MNT_FL_RDONLY_UMOUNT	(1 << 11)	/* remount,ro after EBUSY umount(2) */
+#define MNT_FL_FORK		(1 << 12)
+#define MNT_FL_NOSWAPMATCH	(1 << 13)
+#define MNT_FL_RWONLY_MOUNT	(1 << 14)	/* explicit mount -w; never try read-only  */
+
+#define MNT_FL_MOUNTDATA	(1 << 20)
+#define MNT_FL_TAB_APPLIED	(1 << 21)	/* mtab/fstab merged to cxt->fs */
+#define MNT_FL_MOUNTFLAGS_MERGED (1 << 22)	/* MS_* flags was read from optstr */
+#define MNT_FL_SAVED_USER	(1 << 23)
+#define MNT_FL_PREPARED		(1 << 24)
+#define MNT_FL_HELPER		(1 << 25)	/* [u]mount.<type> */
+#define MNT_FL_LOOPDEV_READY	(1 << 26)	/* /dev/loop<N> initialized by the library */
+#define MNT_FL_MOUNTOPTS_FIXED  (1 << 27)
+#define MNT_FL_TABPATHS_CHECKED	(1 << 28)
+#define MNT_FL_FORCED_RDONLY	(1 << 29)	/* mounted read-only on write-protected device */
+#define MNT_FL_VERITYDEV_READY	(1 << 30)	/* /dev/mapper/<FOO> initialized by the library */
+
+/* default flags */
+#define MNT_FL_DEFAULT		0
+
+/* Flags usable with MS_BIND|MS_REMOUNT */
+#define MNT_BIND_SETTABLE	(MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_NOATIME|MS_NODIRATIME|MS_RELATIME|MS_RDONLY)
+
+/* lock.c */
+extern int mnt_lock_use_simplelock(struct libmnt_lock *ml, int enable);
+
+/* optmap.c */
+extern const struct libmnt_optmap *mnt_optmap_get_entry(
+			     struct libmnt_optmap const **maps,
+                             int nmaps,
+			     const char *name,
+                             size_t namelen,
+			     const struct libmnt_optmap **mapent);
+
+/* optstr.c */
+extern int mnt_optstr_remove_option_at(char **optstr, char *begin, char *end);
+extern int mnt_optstr_fix_gid(char **optstr, char *value, size_t valsz, char **next);
+extern int mnt_optstr_fix_uid(char **optstr, char *value, size_t valsz, char **next);
+extern int mnt_optstr_fix_secontext(char **optstr, char *value, size_t valsz, char **next);
+extern int mnt_optstr_fix_user(char **optstr);
+
+/* fs.c */
+extern struct libmnt_fs *mnt_copy_mtab_fs(const struct libmnt_fs *fs)
+			__attribute__((nonnull));
+extern int __mnt_fs_set_source_ptr(struct libmnt_fs *fs, char *source)
+			__attribute__((nonnull(1)));
+extern int __mnt_fs_set_fstype_ptr(struct libmnt_fs *fs, char *fstype)
+			__attribute__((nonnull(1)));
+
+/* context.c */
+extern struct libmnt_context *mnt_copy_context(struct libmnt_context *o);
+extern int mnt_context_mtab_writable(struct libmnt_context *cxt);
+extern int mnt_context_utab_writable(struct libmnt_context *cxt);
+extern const char *mnt_context_get_writable_tabpath(struct libmnt_context *cxt);
+
+extern int mnt_context_get_mtab_for_target(struct libmnt_context *cxt,
+				    struct libmnt_table **mtab, const char *tgt);
+
+extern int mnt_context_prepare_srcpath(struct libmnt_context *cxt);
+extern int mnt_context_prepare_target(struct libmnt_context *cxt);
+extern int mnt_context_guess_srcpath_fstype(struct libmnt_context *cxt, char **type);
+extern int mnt_context_guess_fstype(struct libmnt_context *cxt);
+extern int mnt_context_prepare_helper(struct libmnt_context *cxt,
+				      const char *name, const char *type);
+extern int mnt_context_prepare_update(struct libmnt_context *cxt);
+extern int mnt_context_merge_mflags(struct libmnt_context *cxt);
+extern int mnt_context_update_tabs(struct libmnt_context *cxt);
+
+extern int mnt_context_umount_setopt(struct libmnt_context *cxt, int c, char *arg);
+extern int mnt_context_mount_setopt(struct libmnt_context *cxt, int c, char *arg);
+
+extern int mnt_context_is_loopdev(struct libmnt_context *cxt)
+			__attribute__((nonnull));
+
+extern int mnt_context_propagation_only(struct libmnt_context *cxt)
+			__attribute__((nonnull));
+
+extern struct libmnt_addmount *mnt_new_addmount(void);
+extern void mnt_free_addmount(struct libmnt_addmount *ad);
+
+extern int mnt_context_setup_loopdev(struct libmnt_context *cxt);
+extern int mnt_context_delete_loopdev(struct libmnt_context *cxt);
+extern int mnt_context_clear_loopdev(struct libmnt_context *cxt);
+
+extern int mnt_fork_context(struct libmnt_context *cxt);
+
+extern int mnt_context_set_tabfilter(struct libmnt_context *cxt,
+				     int (*fltr)(struct libmnt_fs *, void *),
+				     void *data);
+
+extern int mnt_context_get_generic_excode(int rc, char *buf, size_t bufsz, char *fmt, ...);
+extern int mnt_context_get_mount_excode(struct libmnt_context *cxt, int mntrc, char *buf, size_t bufsz);
+extern int mnt_context_get_umount_excode(struct libmnt_context *cxt, int mntrc, char *buf, size_t bufsz);
+
+extern int mnt_context_has_template(struct libmnt_context *cxt);
+extern int mnt_context_apply_template(struct libmnt_context *cxt);
+extern int mnt_context_save_template(struct libmnt_context *cxt);
+
+extern int mnt_context_apply_fs(struct libmnt_context *cxt, struct libmnt_fs *fs);
+
+extern int mnt_context_is_veritydev(struct libmnt_context *cxt)
+			__attribute__((nonnull));
+extern int mnt_context_setup_veritydev(struct libmnt_context *cxt);
+extern int mnt_context_deferred_delete_veritydev(struct libmnt_context *cxt);
+
+/* tab_update.c */
+extern int mnt_update_set_filename(struct libmnt_update *upd,
+				   const char *filename, int userspace_only);
+extern int mnt_update_already_done(struct libmnt_update *upd,
+				   struct libmnt_lock *lc);
+
+#if __linux__
+/* btrfs.c */
+extern uint64_t btrfs_get_default_subvol_id(const char *path);
+#endif
+
+#endif /* _LIBMOUNT_PRIVATE_H */
diff --git a/libmount/src/optmap.c b/libmount/src/optmap.c
new file mode 100644
index 0000000..49e8113
--- /dev/null
+++ b/libmount/src/optmap.c
@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: optmap
+ * @title: Option maps
+ * @short_description: description for mount options
+ *
+ * The mount(2) linux syscall uses two arguments for mount options:
+ *
+ *	@mountflags: (see MS_* macros in linux/fs.h)
+ *
+ *	@mountdata: (usually a comma separated string of options)
+ *
+ * The libmount uses options-map(s) to describe mount options.
+ *
+ * The option description (map entry) includes:
+ *
+ *	@name: and argument name
+ *
+ *	@id: (in the map unique identifier or a mountflags, e.g MS_RDONLY)
+ *
+ *	@mask: (MNT_INVERT, MNT_NOMTAB)
+ *
+ * The option argument value is defined by:
+ *
+ *	"="   -- required argument, e.g "comment="
+ *
+ *	"[=]" -- optional argument, e.g. "loop[=]"
+ *
+ * Example:
+ *
+ * <informalexample>
+ *   <programlisting>
+ *     #define MY_MS_FOO   (1 << 1)
+ *     #define MY_MS_BAR   (1 << 2)
+ *
+ *     libmnt_optmap myoptions[] = {
+ *       { "foo",   MY_MS_FOO },
+ *       { "nofoo", MY_MS_FOO | MNT_INVERT },
+ *       { "bar=",  MY_MS_BAR },
+ *       { NULL }
+ *     };
+ *   </programlisting>
+ * </informalexample>
+ *
+ * The libmount defines two basic built-in options maps:
+ *
+ *	@MNT_LINUX_MAP: fs-independent kernel mount options (usually MS_* flags)
+ *
+ *	@MNT_USERSPACE_MAP: userspace specific mount options (e.g. "user", "loop")
+ *
+ * For more details about option map struct see "struct mnt_optmap" in
+ * mount/mount.h.
+ */
+#include "mountP.h"
+#include "strutils.h"
+
+/*
+ * fs-independent mount flags (built-in MNT_LINUX_MAP)
+ */
+static const struct libmnt_optmap linux_flags_map[] =
+{
+   { "ro",       MS_RDONLY },                 /* read-only */
+   { "rw",       MS_RDONLY, MNT_INVERT },     /* read-write */
+   { "exec",     MS_NOEXEC, MNT_INVERT },     /* permit execution of binaries */
+   { "noexec",   MS_NOEXEC },                 /* don't execute binaries */
+   { "suid",     MS_NOSUID, MNT_INVERT },     /* honor suid executables */
+   { "nosuid",   MS_NOSUID },                 /* don't honor suid executables */
+   { "dev",      MS_NODEV, MNT_INVERT },      /* interpret device files  */
+   { "nodev",    MS_NODEV },                  /* don't interpret devices */
+
+   { "sync",     MS_SYNCHRONOUS },            /* synchronous I/O */
+   { "async",    MS_SYNCHRONOUS, MNT_INVERT },/* asynchronous I/O */
+
+   { "dirsync",  MS_DIRSYNC },                /* synchronous directory modifications */
+   { "remount",  MS_REMOUNT, MNT_NOMTAB },    /* alter flags of mounted FS */
+   { "bind",     MS_BIND },                   /* Remount part of the tree elsewhere */
+   { "rbind",    MS_BIND | MS_REC },          /* Idem, plus mounted subtrees */
+#ifdef MS_NOSUB
+   { "sub",      MS_NOSUB, MNT_INVERT },      /* allow submounts */
+   { "nosub",    MS_NOSUB },                  /* don't allow submounts */
+#endif
+#ifdef MS_SILENT
+   { "silent",	 MS_SILENT },                 /* be quiet  */
+   { "loud",     MS_SILENT, MNT_INVERT },     /* print out messages. */
+#endif
+#ifdef MS_MANDLOCK
+   { "mand",     MS_MANDLOCK },               /* Allow mandatory locks on this FS */
+   { "nomand",   MS_MANDLOCK, MNT_INVERT },   /* Forbid mandatory locks on this FS */
+#endif
+#ifdef MS_NOATIME
+   { "atime",    MS_NOATIME, MNT_INVERT },    /* Update access time */
+   { "noatime",	 MS_NOATIME },                /* Do not update access time */
+#endif
+#ifdef MS_I_VERSION
+   { "iversion", MS_I_VERSION },              /* Update inode I_version time */
+   { "noiversion", MS_I_VERSION,  MNT_INVERT},/* Don't update inode I_version time */
+#endif
+#ifdef MS_NODIRATIME
+   { "diratime", MS_NODIRATIME, MNT_INVERT }, /* Update dir access times */
+   { "nodiratime", MS_NODIRATIME },           /* Do not update dir access times */
+#endif
+#ifdef MS_RELATIME
+   { "relatime", MS_RELATIME },               /* Update access times relative to mtime/ctime */
+   { "norelatime", MS_RELATIME, MNT_INVERT }, /* Update access time without regard to mtime/ctime */
+#endif
+#ifdef MS_STRICTATIME
+   { "strictatime", MS_STRICTATIME },         /* Strict atime semantics */
+   { "nostrictatime", MS_STRICTATIME, MNT_INVERT }, /* kernel default atime */
+#endif
+#ifdef MS_LAZYTIME
+   { "lazytime", MS_LAZYTIME },               /* Update {a,m,c}time on the in-memory inode only */
+   { "nolazytime", MS_LAZYTIME, MNT_INVERT },
+#endif
+#ifdef MS_PROPAGATION
+   { "unbindable",  MS_UNBINDABLE,          MNT_NOHLPS | MNT_NOMTAB }, /* Unbindable */
+   { "runbindable", MS_UNBINDABLE | MS_REC, MNT_NOHLPS | MNT_NOMTAB },
+   { "private",     MS_PRIVATE,             MNT_NOHLPS | MNT_NOMTAB }, /* Private */
+   { "rprivate",    MS_PRIVATE | MS_REC,    MNT_NOHLPS | MNT_NOMTAB },
+   { "slave",       MS_SLAVE,               MNT_NOHLPS | MNT_NOMTAB }, /* Slave */
+   { "rslave",      MS_SLAVE | MS_REC,      MNT_NOHLPS | MNT_NOMTAB },
+   { "shared",      MS_SHARED,              MNT_NOHLPS | MNT_NOMTAB }, /* Shared */
+   { "rshared",     MS_SHARED | MS_REC,     MNT_NOHLPS | MNT_NOMTAB },
+#endif
+#ifdef MS_NOSYMFOLLOW
+   { "symfollow", MS_NOSYMFOLLOW, MNT_INVERT }, /* Don't follow symlinks */
+   { "nosymfollow", MS_NOSYMFOLLOW },
+#endif
+   { NULL, 0, 0 }
+};
+
+/*
+ * userspace mount option (built-in MNT_USERSPACE_MAP)
+ */
+static const struct libmnt_optmap userspace_opts_map[] =
+{
+   { "defaults", 0, 0 },               /* default options */
+
+   { "auto",    MNT_MS_NOAUTO, MNT_NOHLPS | MNT_INVERT | MNT_NOMTAB },  /* Can be mounted using -a */
+   { "noauto",  MNT_MS_NOAUTO, MNT_NOHLPS | MNT_NOMTAB },  /* Can only be mounted explicitly */
+
+   { "user[=]", MNT_MS_USER },                             /* Allow ordinary user to mount (mtab) */
+   { "nouser",  MNT_MS_USER, MNT_INVERT | MNT_NOMTAB },    /* Forbid ordinary user to mount */
+
+   { "users",   MNT_MS_USERS, MNT_NOMTAB },                /* Allow ordinary users to mount */
+   { "nousers", MNT_MS_USERS, MNT_INVERT | MNT_NOMTAB },   /* Forbid ordinary users to mount */
+
+   { "owner",   MNT_MS_OWNER, MNT_NOMTAB },                /* Let the owner of the device mount */
+   { "noowner", MNT_MS_OWNER, MNT_INVERT | MNT_NOMTAB },   /* Device owner has no special privs */
+
+   { "group",   MNT_MS_GROUP, MNT_NOMTAB },                /* Let the group of the device mount */
+   { "nogroup", MNT_MS_GROUP, MNT_INVERT | MNT_NOMTAB },   /* Device group has no special privs */
+
+   /*
+    * Note that traditional init scripts assume the _netdev option in /etc/mtab to
+    * umount network block devices on shutdown.
+    */
+   { "_netdev", MNT_MS_NETDEV },                           /* Device requires network */
+
+   { "comment=", MNT_MS_COMMENT, MNT_NOHLPS | MNT_NOMTAB },/* fstab comment only */
+
+   { "x-",      MNT_MS_XCOMMENT,   MNT_NOHLPS | MNT_PREFIX },              /* persistent comments (utab) */
+   { "X-",      MNT_MS_XFSTABCOMM, MNT_NOHLPS | MNT_NOMTAB | MNT_PREFIX }, /* fstab only comments */
+
+   { "loop[=]", MNT_MS_LOOP, MNT_NOHLPS },                             /* use the loop device */
+   { "offset=", MNT_MS_OFFSET, MNT_NOHLPS | MNT_NOMTAB },		   /* loop device offset */
+   { "sizelimit=", MNT_MS_SIZELIMIT, MNT_NOHLPS | MNT_NOMTAB },	   /* loop device size limit */
+   { "encryption=", MNT_MS_ENCRYPTION, MNT_NOHLPS | MNT_NOMTAB },	   /* loop device encryption */
+
+   { "nofail",  MNT_MS_NOFAIL, MNT_NOMTAB },               /* Do not fail if ENOENT on dev */
+
+   { "uhelper=", MNT_MS_UHELPER },			   /* /sbin/umount.<helper> */
+
+   { "helper=", MNT_MS_HELPER },			   /* /sbin/mount.<helper> */
+
+   { "verity.hashdevice=", MNT_MS_HASH_DEVICE, MNT_NOHLPS | MNT_NOMTAB },     /* mount a verity device */
+   { "verity.roothash=",   MNT_MS_ROOT_HASH, MNT_NOHLPS | MNT_NOMTAB },		   /* verity device root hash */
+   { "verity.hashoffset=", MNT_MS_HASH_OFFSET, MNT_NOHLPS | MNT_NOMTAB },	   /* verity device hash offset */
+   { "verity.roothashfile=", MNT_MS_ROOT_HASH_FILE, MNT_NOHLPS | MNT_NOMTAB },/* verity device root hash (read from file) */
+   { "verity.fecdevice=",   MNT_MS_FEC_DEVICE, MNT_NOHLPS | MNT_NOMTAB },		/* verity FEC device */
+   { "verity.fecoffset=", MNT_MS_FEC_OFFSET, MNT_NOHLPS | MNT_NOMTAB },	      /* verity FEC area offset */
+   { "verity.fecroots=", MNT_MS_FEC_ROOTS, MNT_NOHLPS | MNT_NOMTAB },	      /* verity FEC roots */
+   { "verity.roothashsig=",    MNT_MS_ROOT_HASH_SIG, MNT_NOHLPS | MNT_NOMTAB },	/* verity device root hash signature file */
+
+   { NULL, 0, 0 }
+};
+
+/**
+ * mnt_get_builtin_map:
+ * @id: map id -- MNT_LINUX_MAP or MNT_USERSPACE_MAP
+ *
+ * MNT_LINUX_MAP - Linux kernel fs-independent mount options
+ *                 (usually MS_* flags, see linux/fs.h)
+ *
+ * MNT_USERSPACE_MAP - userspace mount(8) specific mount options
+ *                     (e.g user=, _netdev, ...)
+ *
+ * Returns: static built-in libmount map.
+ */
+const struct libmnt_optmap *mnt_get_builtin_optmap(int id)
+{
+	assert(id);
+
+	if (id == MNT_LINUX_MAP)
+		return linux_flags_map;
+	if (id == MNT_USERSPACE_MAP)
+		return userspace_opts_map;
+	return NULL;
+}
+
+/*
+ * Looks up the @name in @maps and returns a map and in @mapent
+ * returns the map entry
+ */
+const struct libmnt_optmap *mnt_optmap_get_entry(
+				struct libmnt_optmap const **maps,
+				int nmaps,
+				const char *name,
+				size_t namelen,
+				const struct libmnt_optmap **mapent)
+{
+	int i;
+
+	assert(maps);
+	assert(nmaps);
+	assert(name);
+	assert(namelen);
+
+	if (mapent)
+		*mapent = NULL;
+
+	for (i = 0; i < nmaps; i++) {
+		const struct libmnt_optmap *map = maps[i];
+		const struct libmnt_optmap *ent;
+		const char *p;
+
+		for (ent = map; ent && ent->name; ent++) {
+			if (ent->mask & MNT_PREFIX) {
+				if (startswith(name, ent->name)) {
+					if (mapent)
+						*mapent = ent;
+					return map;
+				}
+				continue;
+			}
+			if (strncmp(ent->name, name, namelen) != 0)
+				continue;
+			p = ent->name + namelen;
+			if (*p == '\0' || *p == '=' || *p == '[') {
+				if (mapent)
+					*mapent = ent;
+				return map;
+			}
+		}
+	}
+	return NULL;
+}
+
diff --git a/libmount/src/optstr.c b/libmount/src/optstr.c
new file mode 100644
index 0000000..ea933c6
--- /dev/null
+++ b/libmount/src/optstr.c
@@ -0,0 +1,1442 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: optstr
+ * @title: Options string
+ * @short_description: low-level API for working with mount options
+ *
+ * This is a simple and low-level API to working with mount options that are stored
+ * in a string.
+ */
+#include <ctype.h>
+
+#ifdef HAVE_LIBSELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#endif
+
+#include "strutils.h"
+#include "mountP.h"
+
+/*
+ * Option location
+ */
+struct libmnt_optloc {
+	char	*begin;
+	char	*end;
+	char	*value;
+	size_t	valsz;
+	size_t  namesz;
+};
+
+#define mnt_init_optloc(_ol)	(memset((_ol), 0, sizeof(struct libmnt_optloc)))
+
+#define mnt_optmap_entry_novalue(e) \
+		(e && (e)->name && !strchr((e)->name, '=') && !((e)->mask & MNT_PREFIX))
+
+/*
+ * Parses the first option from @optstr. The @optstr pointer is set to the beginning
+ * of the next option.
+ *
+ * Returns -EINVAL on parse error, 1 at the end of optstr and 0 on success.
+ */
+static int mnt_optstr_parse_next(char **optstr,	 char **name, size_t *namesz,
+					char **value, size_t *valsz)
+{
+	int open_quote = 0;
+	char *start = NULL, *stop = NULL, *p, *sep = NULL;
+	char *optstr0;
+
+	assert(optstr);
+	assert(*optstr);
+
+	optstr0 = *optstr;
+
+	if (name)
+		*name = NULL;
+	if (namesz)
+		*namesz = 0;
+	if (value)
+		*value = NULL;
+	if (valsz)
+		*valsz = 0;
+
+	/* trim leading commas as to not invalidate option
+	 * strings with multiple consecutive commas */
+	while (optstr0 && *optstr0 == ',')
+		optstr0++;
+
+	for (p = optstr0; p && *p; p++) {
+		if (!start)
+			start = p;		/* beginning of the option item */
+		if (*p == '"')
+			open_quote ^= 1;	/* reverse the status */
+		if (open_quote)
+			continue;		/* still in quoted block */
+		if (!sep && p > start && *p == '=')
+			sep = p;		/* name and value separator */
+		if (*p == ',')
+			stop = p;		/* terminate the option item */
+		else if (*(p + 1) == '\0')
+			stop = p + 1;		/* end of optstr */
+		if (!start || !stop)
+			continue;
+		if (stop <= start)
+			goto error;
+
+		if (name)
+			*name = start;
+		if (namesz)
+			*namesz = sep ? sep - start : stop - start;
+		*optstr = *stop ? stop + 1 : stop;
+
+		if (sep) {
+			if (value)
+				*value = sep + 1;
+			if (valsz)
+				*valsz = stop - sep - 1;
+		}
+		return 0;
+	}
+
+	return 1;				/* end of optstr */
+
+error:
+	DBG(OPTIONS, ul_debug("parse error: \"%s\"", optstr0));
+	return -EINVAL;
+}
+
+/*
+ * Locates the first option that matches @name. The @end is set to the
+ * char behind the option (it means ',' or \0).
+ *
+ * Returns negative number on parse error, 1 when not found and 0 on success.
+ */
+static int mnt_optstr_locate_option(char *optstr, const char *name,
+					struct libmnt_optloc *ol)
+{
+	char *n;
+	size_t namesz, nsz;
+	int rc;
+
+	if (!optstr)
+		return 1;
+
+	assert(name);
+
+	namesz = strlen(name);
+
+	do {
+		rc = mnt_optstr_parse_next(&optstr, &n, &nsz,
+					&ol->value, &ol->valsz);
+		if (rc)
+			break;
+
+		if (namesz == nsz && strncmp(n, name, nsz) == 0) {
+			ol->begin = n;
+			ol->end = *(optstr - 1) == ',' ? optstr - 1 : optstr;
+			ol->namesz = nsz;
+			return 0;
+		}
+	} while(1);
+
+	return rc;
+}
+
+/**
+ * mnt_optstr_next_option:
+ * @optstr: option string, returns the position of the next option
+ * @name: returns the option name
+ * @namesz: returns the option name length
+ * @value: returns the option value or NULL
+ * @valuesz: returns the option value length or zero
+ *
+ * Parses the first option in @optstr.
+ *
+ * Returns: 0 on success, 1 at the end of @optstr or negative number in case of
+ * error.
+ */
+int mnt_optstr_next_option(char **optstr, char **name, size_t *namesz,
+					char **value, size_t *valuesz)
+{
+	if (!optstr || !*optstr)
+		return -EINVAL;
+	return mnt_optstr_parse_next(optstr, name, namesz, value, valuesz);
+}
+
+static int __mnt_optstr_append_option(char **optstr,
+			const char *name, size_t nsz,
+			const char *value, size_t vsz)
+{
+	char *p;
+	size_t sz, osz;
+
+	assert(name);
+	assert(*name);
+	assert(nsz);
+	assert(optstr);
+
+	osz = *optstr ? strlen(*optstr) : 0;
+
+	sz = osz + nsz + 1;		/* 1: '\0' */
+	if (osz)
+		sz++;			/* ',' options separator */
+	if (value)
+		sz += vsz + 1;		/* 1: '=' */
+
+	p = realloc(*optstr, sz);
+	if (!p)
+		return -ENOMEM;
+	*optstr = p;
+
+	if (osz) {
+		p += osz;
+		*p++ = ',';
+	}
+
+	memcpy(p, name, nsz);
+	p += nsz;
+
+	if (value) {
+		*p++ = '=';
+		memcpy(p, value, vsz);
+		p += vsz;
+	}
+	*p = '\0';
+
+	return 0;
+}
+
+/**
+ * mnt_optstr_append_option:
+ * @optstr: option string or NULL, returns a reallocated string
+ * @name: value name
+ * @value: value
+ *
+ * Returns: 0 on success or <0 in case of error. After an error the @optstr should
+ *          be unmodified.
+ */
+int mnt_optstr_append_option(char **optstr, const char *name, const char *value)
+{
+	size_t vsz, nsz;
+
+	if (!optstr)
+		return -EINVAL;
+	if (!name || !*name)
+		return 0;
+
+	nsz = strlen(name);
+	vsz = value ? strlen(value) : 0;
+
+	return __mnt_optstr_append_option(optstr, name, nsz, value, vsz);
+}
+
+/**
+ * mnt_optstr_prepend_option:
+ * @optstr: option string or NULL, returns a reallocated string
+ * @name: value name
+ * @value: value
+ *
+ * Returns: 0 on success or <0 in case of error. After an error the @optstr should
+ *          be unmodified.
+ */
+int mnt_optstr_prepend_option(char **optstr, const char *name, const char *value)
+{
+	int rc = 0;
+	char *tmp;
+
+	if (!optstr)
+		return -EINVAL;
+	if (!name || !*name)
+		return 0;
+
+	tmp = *optstr;
+	*optstr = NULL;
+
+	rc = mnt_optstr_append_option(optstr, name, value);
+	if (!rc && tmp && *tmp)
+		rc = mnt_optstr_append_option(optstr, tmp, NULL);
+	if (!rc) {
+		free(tmp);
+		return 0;
+	}
+
+	free(*optstr);
+	*optstr = tmp;
+
+	DBG(OPTIONS, ul_debug("failed to prepend '%s[=%s]' to '%s'",
+				name, value, *optstr));
+	return rc;
+}
+
+/**
+ * mnt_optstr_get_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ * @value: returns a pointer to the beginning of the value (e.g. name=VALUE) or NULL
+ * @valsz: returns size of the value or 0
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_get_option(const char *optstr, const char *name,
+			  char **value, size_t *valsz)
+{
+	struct libmnt_optloc ol;
+	int rc;
+
+	if (!optstr || !name)
+		return -EINVAL;
+
+	mnt_init_optloc(&ol);
+
+	rc = mnt_optstr_locate_option((char *) optstr, name, &ol);
+	if (!rc) {
+		if (value)
+			*value = ol.value;
+		if (valsz)
+			*valsz = ol.valsz;
+	}
+	return rc;
+}
+
+/**
+ * mnt_optstr_deduplicate_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ *
+ * Removes all instances of @name except the last one.
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_deduplicate_option(char **optstr, const char *name)
+{
+	int rc;
+	char *begin = NULL, *end = NULL, *opt;
+
+	if (!optstr || !name)
+		return -EINVAL;
+
+	opt = *optstr;
+	do {
+		struct libmnt_optloc ol;
+
+		mnt_init_optloc(&ol);
+
+		rc = mnt_optstr_locate_option(opt, name, &ol);
+		if (!rc) {
+			if (begin) {
+				/* remove the previous instance */
+				size_t shift = strlen(*optstr);
+
+				mnt_optstr_remove_option_at(optstr, begin, end);
+
+				/* now all the offsets are not valid anymore - recount */
+				shift -= strlen(*optstr);
+				ol.begin -= shift;
+				ol.end -= shift;
+			}
+			begin = ol.begin;
+			end = ol.end;
+			opt = end && *end ? end + 1 : NULL;
+		}
+		if (opt == NULL)
+			break;
+	} while (rc == 0 && *opt);
+
+	return rc < 0 ? rc : begin ? 0 : 1;
+}
+
+/*
+ * The result never starts or ends with a comma or contains two commas
+ *    (e.g. ",aaa,bbb" or "aaa,,bbb" or "aaa,")
+ */
+int mnt_optstr_remove_option_at(char **optstr, char *begin, char *end)
+{
+	size_t sz;
+
+	if (!optstr || !begin || !end)
+		return -EINVAL;
+
+	if ((begin == *optstr || *(begin - 1) == ',') && *end == ',')
+		end++;
+
+	sz = strlen(end);
+
+	memmove(begin, end, sz + 1);
+	if (!*begin && (begin > *optstr) && *(begin - 1) == ',')
+		*(begin - 1) = '\0';
+
+	return 0;
+}
+
+/* insert 'substr' or '=substr' to @str on position @pos */
+static int __attribute__((nonnull(1,2,3)))
+insert_value(char **str, char *pos, const char *substr, char **next)
+{
+	size_t subsz = strlen(substr);			/* substring size */
+	size_t strsz = strlen(*str);
+	size_t possz = strlen(pos);
+	size_t posoff;
+	char *p;
+	int sep;
+
+	/* is it necessary to prepend '=' before the substring ? */
+	sep = !(pos > *str && *(pos - 1) == '=');
+
+	/* save an offset of the place where we need to add substr */
+	posoff = pos - *str;
+
+	p = realloc(*str, strsz + sep + subsz + 1);
+	if (!p)
+		return -ENOMEM;
+
+	/* zeroize the newly allocated memory -- valgrind loves us... */
+	memset(p + strsz, 0, sep + subsz + 1);
+
+	/* set pointers to the reallocated string */
+	*str = p;
+	pos = p + posoff;
+
+	if (possz)
+		/* create a room for the new substring */
+		memmove(pos + subsz + sep, pos, possz + 1);
+	if (sep)
+		*pos++ = '=';
+
+	memcpy(pos, substr, subsz);
+
+	if (next) {
+		/* set pointer to the next option */
+		*next = pos + subsz;
+		if (**next == ',')
+			(*next)++;
+	}
+	return 0;
+}
+
+/**
+ * mnt_optstr_set_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option
+ * @value: new value or NULL
+ *
+ * Set or unset the option @value.
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_set_option(char **optstr, const char *name, const char *value)
+{
+	struct libmnt_optloc ol;
+	char *nameend;
+	int rc = 1;
+
+	if (!optstr || !name)
+		return -EINVAL;
+
+	mnt_init_optloc(&ol);
+
+	if (*optstr)
+		rc = mnt_optstr_locate_option(*optstr, name, &ol);
+	if (rc < 0)
+		return rc;			/* parse error */
+	if (rc == 1)
+		return mnt_optstr_append_option(optstr, name, value);	/* not found */
+
+	nameend = ol.begin + ol.namesz;
+
+	if (value == NULL && ol.value && ol.valsz)
+		/* remove unwanted "=value" */
+		mnt_optstr_remove_option_at(optstr, nameend, ol.end);
+
+	else if (value && ol.value == NULL)
+		/* insert "=value" */
+		rc = insert_value(optstr, nameend, value, NULL);
+
+	else if (value && ol.value && strlen(value) == ol.valsz)
+		/* simply replace =value */
+		memcpy(ol.value, value, ol.valsz);
+
+	else if (value && ol.value) {
+		mnt_optstr_remove_option_at(optstr, nameend, ol.end);
+		rc = insert_value(optstr, nameend, value, NULL);
+	}
+	return rc;
+}
+
+/**
+ * mnt_optstr_remove_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_remove_option(char **optstr, const char *name)
+{
+	struct libmnt_optloc ol;
+	int rc;
+
+	if (!optstr || !name)
+		return -EINVAL;
+
+	mnt_init_optloc(&ol);
+
+	rc = mnt_optstr_locate_option(*optstr, name, &ol);
+	if (rc != 0)
+		return rc;
+
+	mnt_optstr_remove_option_at(optstr, ol.begin, ol.end);
+	return 0;
+}
+
+/**
+ * mnt_split_optstr:
+ * @optstr: string with comma separated list of options
+ * @user: returns newly allocated string with userspace options
+ * @vfs: returns newly allocated string with VFS options
+ * @fs: returns newly allocated string with FS options
+ * @ignore_user: option mask for options that should be ignored
+ * @ignore_vfs: option mask for options that should be ignored
+ *
+ * For example:
+ *
+ *	mnt_split_optstr(optstr, &u, NULL, NULL, MNT_NOMTAB, 0);
+ *
+ * returns all userspace options, the options that do not belong to
+ * mtab are ignored.
+ *
+ * Note that FS options are all options that are undefined in MNT_USERSPACE_MAP
+ * or MNT_LINUX_MAP.
+ *
+ * Returns: 0 on success, or a negative number in case of error.
+ */
+int mnt_split_optstr(const char *optstr, char **user, char **vfs,
+		     char **fs, int ignore_user, int ignore_vfs)
+{
+	char *name, *val, *str = (char *) optstr;
+	size_t namesz, valsz;
+	struct libmnt_optmap const *maps[2];
+
+	if (!optstr)
+		return -EINVAL;
+
+	maps[0] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
+	maps[1] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
+
+	if (vfs)
+		*vfs = NULL;
+	if (fs)
+		*fs = NULL;
+	if (user)
+		*user = NULL;
+
+	while (!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
+		int rc = 0;
+		const struct libmnt_optmap *ent = NULL;
+		const struct libmnt_optmap *m =
+			 mnt_optmap_get_entry(maps, 2, name, namesz, &ent);
+
+		if (ent && !ent->id)
+			continue;	/* ignore undefined options (comments) */
+
+		/* ignore name=<value> if options map expects <name> only */
+		if (valsz && mnt_optmap_entry_novalue(ent))
+			m = NULL;
+
+		if (ent && m && m == maps[0] && vfs) {
+			if (ignore_vfs && (ent->mask & ignore_vfs))
+				continue;
+			rc = __mnt_optstr_append_option(vfs, name, namesz,
+								val, valsz);
+		} else if (ent && m && m == maps[1] && user) {
+			if (ignore_user && (ent->mask & ignore_user))
+				continue;
+			rc = __mnt_optstr_append_option(user, name, namesz,
+								val, valsz);
+		} else if (!m && fs)
+			rc = __mnt_optstr_append_option(fs, name, namesz,
+								val, valsz);
+		if (rc) {
+			if (vfs) {
+				free(*vfs);
+				*vfs = NULL;
+			}
+			if (fs) {
+				free(*fs);
+				*fs = NULL;
+			}
+			if (user) {
+				free(*user);
+				*user = NULL;
+			}
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * mnt_optstr_get_options
+ * @optstr: string with a comma separated list of options
+ * @subset: returns newly allocated string with options
+ * @map: options map
+ * @ignore: mask of the options that should be ignored
+ *
+ * Extracts options from @optstr that belong to the @map, for example:
+ *
+ *	 mnt_optstr_get_options(optstr, &p,
+ *			mnt_get_builtin_optmap(MNT_LINUX_MAP),
+ *			MNT_NOMTAB);
+ *
+ * the 'p' returns all VFS options, the options that do not belong to mtab
+ * are ignored.
+ *
+ * Returns: 0 on success, or a negative number in case of error.
+ */
+int mnt_optstr_get_options(const char *optstr, char **subset,
+			    const struct libmnt_optmap *map, int ignore)
+{
+	struct libmnt_optmap const *maps[1];
+	char *name, *val, *str = (char *) optstr;
+	size_t namesz, valsz;
+
+	if (!optstr || !subset)
+		return -EINVAL;
+
+	maps[0] = map;
+	*subset = NULL;
+
+	while(!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
+		int rc = 0;
+		const struct libmnt_optmap *ent;
+
+		mnt_optmap_get_entry(maps, 1, name, namesz, &ent);
+
+		if (!ent || !ent->id)
+			continue;	/* ignore undefined options (comments) */
+
+		if (ignore && (ent->mask & ignore))
+			continue;
+
+		/* ignore name=<value> if options map expects <name> only */
+		if (valsz && mnt_optmap_entry_novalue(ent))
+			continue;
+
+		rc = __mnt_optstr_append_option(subset, name, namesz, val, valsz);
+		if (rc) {
+			free(*subset);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+
+/**
+ * mnt_optstr_get_flags:
+ * @optstr: string with comma separated list of options
+ * @flags: returns mount flags
+ * @map: options map
+ *
+ * Returns in @flags IDs of options from @optstr as defined in the @map.
+ *
+ * For example:
+ *
+ *	"bind,exec,foo,bar"   --returns->   MS_BIND
+ *
+ *	"bind,noexec,foo,bar" --returns->   MS_BIND|MS_NOEXEC
+ *
+ * Note that @flags are not zeroized by this function! This function sets/unsets
+ * bits in the @flags only.
+ *
+ * Returns: 0 on success or negative number in case of error
+ */
+int mnt_optstr_get_flags(const char *optstr, unsigned long *flags,
+		const struct libmnt_optmap *map)
+{
+	struct libmnt_optmap const *maps[2];
+	char *name, *str = (char *) optstr;
+	size_t namesz = 0, valsz = 0;
+	int nmaps = 0;
+
+	if (!optstr || !flags || !map)
+		return -EINVAL;
+
+	maps[nmaps++] = map;
+
+	if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP))
+		/*
+		 * Add userspace map -- the "user" is interpreted as
+		 *                      MS_NO{EXEC,SUID,DEV}.
+		 */
+		maps[nmaps++] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
+
+	while(!mnt_optstr_next_option(&str, &name, &namesz, NULL, &valsz)) {
+		const struct libmnt_optmap *ent;
+		const struct libmnt_optmap *m;
+
+		m = mnt_optmap_get_entry(maps, nmaps, name, namesz, &ent);
+		if (!m || !ent || !ent->id)
+			continue;
+
+		/* ignore name=<value> if options map expects <name> only */
+		if (valsz && mnt_optmap_entry_novalue(ent))
+			continue;
+
+		if (m == map) {				/* requested map */
+			if (ent->mask & MNT_INVERT)
+				*flags &= ~ent->id;
+			else
+				*flags |= ent->id;
+
+		} else if (nmaps == 2 && m == maps[1] && valsz == 0) {
+			/*
+			 * Special case -- translate "user" (but no user=) to
+			 * MS_ options
+			 */
+			if (ent->mask & MNT_INVERT)
+				continue;
+			if (ent->id & (MNT_MS_OWNER | MNT_MS_GROUP))
+				*flags |= MS_OWNERSECURE;
+			else if (ent->id & (MNT_MS_USER | MNT_MS_USERS))
+				*flags |= MS_SECURE;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * mnt_optstr_apply_flags:
+ * @optstr: string with comma separated list of options
+ * @flags: returns mount flags
+ * @map: options map
+ *
+ * Removes/adds options to the @optstr according to flags. For example:
+ *
+ *	MS_NOATIME and "foo,bar,noexec"   --returns->  "foo,bar,noatime"
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
+				const struct libmnt_optmap *map)
+{
+	struct libmnt_optmap const *maps[1];
+	char *name, *next, *val;
+	size_t namesz = 0, valsz = 0;
+	unsigned long fl;
+	int rc = 0;
+
+	if (!optstr || !map)
+		return -EINVAL;
+
+	DBG(CXT, ul_debug("applying 0x%08lx flags to '%s'", flags, *optstr));
+
+	maps[0] = map;
+	next = *optstr;
+	fl = flags;
+
+	/*
+	 * There is a convention that 'rw/ro' flags are always at the beginning of
+	 * the string (although the 'rw' is unnecessary).
+	 */
+	if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP)) {
+		const char *o = (fl & MS_RDONLY) ? "ro" : "rw";
+
+		if (next &&
+		    (!strncmp(next, "rw", 2) || !strncmp(next, "ro", 2)) &&
+		    (*(next + 2) == '\0' || *(next + 2) == ',')) {
+
+			/* already set, be paranoid and fix it */
+			memcpy(next, o, 2);
+		} else {
+			rc = mnt_optstr_prepend_option(optstr, o, NULL);
+			if (rc)
+				goto err;
+			next = *optstr;		/* because realloc() */
+		}
+		fl &= ~MS_RDONLY;
+		next += 2;
+		if (*next == ',')
+			next++;
+	}
+
+	if (next && *next) {
+		/*
+		 * scan @optstr and remove options that are missing in
+		 * @flags
+		 */
+		while(!mnt_optstr_next_option(&next, &name, &namesz,
+							&val, &valsz)) {
+			const struct libmnt_optmap *ent;
+
+			if (mnt_optmap_get_entry(maps, 1, name, namesz, &ent)) {
+				/*
+				 * remove unwanted option (rw/ro is already set)
+				 */
+				if (!ent || !ent->id)
+					continue;
+				/* ignore name=<value> if options map expects <name> only */
+				if (valsz && mnt_optmap_entry_novalue(ent))
+					continue;
+
+				if (ent->id == MS_RDONLY ||
+				    (ent->mask & MNT_INVERT) ||
+				    (fl & ent->id) != (unsigned long) ent->id) {
+
+					char *end = val ? val + valsz :
+							  name + namesz;
+					next = name;
+					rc = mnt_optstr_remove_option_at(
+							optstr, name, end);
+					if (rc)
+						goto err;
+				}
+				if (!(ent->mask & MNT_INVERT)) {
+					fl &= ~ent->id;
+					if (ent->id & MS_REC)
+						fl |= MS_REC;
+				}
+			}
+		}
+	}
+
+	/* add missing options (but ignore fl if contains MS_REC only) */
+	if (fl && fl != MS_REC) {
+		const struct libmnt_optmap *ent;
+		char *p;
+
+		for (ent = map; ent && ent->name; ent++) {
+			if ((ent->mask & MNT_INVERT)
+			    || ent->id == 0
+			    || (fl & ent->id) != (unsigned long) ent->id)
+				continue;
+
+			/* don't add options which require values (e.g. offset=%d) */
+			p = strchr(ent->name, '=');
+			if (p) {
+				if (p > ent->name && *(p - 1) == '[')
+					p--;			/* name[=] */
+				else
+					continue;		/* name= */
+
+				p = strndup(ent->name, p - ent->name);
+				if (!p) {
+					rc = -ENOMEM;
+					goto err;
+				}
+				mnt_optstr_append_option(optstr, p, NULL);
+				free(p);
+			} else
+				mnt_optstr_append_option(optstr, ent->name, NULL);
+		}
+	}
+
+	DBG(CXT, ul_debug("new optstr '%s'", *optstr));
+	return rc;
+err:
+	DBG(CXT, ul_debug("failed to apply flags [rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * @optstr: string with comma separated list of options
+ * @value: pointer to the begin of the context value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+ *
+ * Translates SELinux context from human to raw format. The function does not
+ * modify @optstr and returns zero if libmount is compiled without SELinux
+ * support.
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+#ifndef HAVE_LIBSELINUX
+int mnt_optstr_fix_secontext(char **optstr __attribute__ ((__unused__)),
+			     char *value   __attribute__ ((__unused__)),
+			     size_t valsz  __attribute__ ((__unused__)),
+			     char **next   __attribute__ ((__unused__)))
+{
+	return 0;
+}
+#else
+int mnt_optstr_fix_secontext(char **optstr,
+			     char *value,
+			     size_t valsz,
+			     char **next)
+{
+	int rc = 0;
+
+	security_context_t raw = NULL;
+	char *p, *val, *begin, *end;
+	size_t sz;
+
+	if (!optstr || !*optstr || !value || !valsz)
+		return -EINVAL;
+
+	DBG(CXT, ul_debug("fixing SELinux context"));
+
+	begin = value;
+	end = value + valsz;
+
+	/* the selinux contexts are quoted */
+	if (*value == '"') {
+		if (valsz <= 2 || *(value + valsz - 1) != '"')
+			return -EINVAL;		/* improperly quoted option string */
+		value++;
+		valsz -= 2;
+	}
+
+	p = strndup(value, valsz);
+	if (!p)
+		return -ENOMEM;
+
+
+	/* translate the context */
+	rc = selinux_trans_to_raw_context((security_context_t) p, &raw);
+
+	DBG(CXT, ul_debug("SELinux context '%s' translated to '%s'",
+			p, rc == -1 ? "FAILED" : (char *) raw));
+
+	free(p);
+	if (rc == -1 ||	!raw)
+		return -EINVAL;
+
+
+	/* create a quoted string from the raw context */
+	sz = strlen((char *) raw);
+	if (!sz)
+		return -EINVAL;
+
+	p = val = malloc(valsz + 3);
+	if (!val)
+		return -ENOMEM;
+
+	*p++ = '"';
+	memcpy(p, raw, sz);
+	p += sz;
+	*p++ = '"';
+	*p = '\0';
+
+	freecon(raw);
+
+	/* set new context */
+	mnt_optstr_remove_option_at(optstr, begin, end);
+	rc = insert_value(optstr, begin, val, next);
+	free(val);
+
+	return rc;
+}
+#endif
+
+static int set_uint_value(char **optstr, unsigned int num,
+			char *begin, char *end, char **next)
+{
+	char buf[40];
+	snprintf(buf, sizeof(buf), "%u", num);
+
+	mnt_optstr_remove_option_at(optstr, begin, end);
+	return insert_value(optstr, begin, buf, next);
+}
+
+/*
+ * @optstr: string with a comma separated list of options
+ * @value: pointer to the beginning of the uid value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+
+ * Translates "username" or "useruid" to the real UID.
+ *
+ * For example:
+ *	if (!mnt_optstr_get_option(optstr, "uid", &val, &valsz))
+ *		mnt_optstr_fix_uid(&optstr, val, valsz, NULL);
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+int mnt_optstr_fix_uid(char **optstr, char *value, size_t valsz, char **next)
+{
+	char *end;
+
+	if (!optstr || !*optstr || !value || !valsz)
+		return -EINVAL;
+
+	DBG(CXT, ul_debug("fixing uid"));
+
+	end = value + valsz;
+
+	if (valsz == 7 && !strncmp(value, "useruid", 7) &&
+	    (*(value + 7) == ',' || !*(value + 7)))
+		return set_uint_value(optstr, getuid(), value, end, next);
+
+	if (!isdigit(*value)) {
+		uid_t id;
+		int rc;
+		char *p = strndup(value, valsz);
+		if (!p)
+			return -ENOMEM;
+		rc = mnt_get_uid(p, &id);
+		free(p);
+
+		if (!rc)
+			return set_uint_value(optstr, id, value, end, next);
+	}
+
+	if (next) {
+		/* no change, let's keep the original value */
+		*next = value + valsz;
+		if (**next == ',')
+			(*next)++;
+	}
+
+	return 0;
+}
+
+/*
+ * @optstr: string with a comma separated list of options
+ * @value: pointer to the beginning of the uid value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+
+ * Translates "groupname" or "usergid" to the real GID.
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+int mnt_optstr_fix_gid(char **optstr, char *value, size_t valsz, char **next)
+{
+	char *end;
+
+	if (!optstr || !*optstr || !value || !valsz)
+		return -EINVAL;
+
+	DBG(CXT, ul_debug("fixing gid"));
+
+	end = value + valsz;
+
+	if (valsz == 7 && !strncmp(value, "usergid", 7) &&
+	    (*(value + 7) == ',' || !*(value + 7)))
+		return set_uint_value(optstr, getgid(), value, end, next);
+
+	if (!isdigit(*value)) {
+		int rc;
+		gid_t id;
+		char *p = strndup(value, valsz);
+		if (!p)
+			return -ENOMEM;
+		rc = mnt_get_gid(p, &id);
+		free(p);
+
+		if (!rc)
+			return set_uint_value(optstr, id, value, end, next);
+
+	}
+
+	if (next) {
+		/* nothing */
+		*next = value + valsz;
+		if (**next == ',')
+			(*next)++;
+	}
+	return 0;
+}
+
+/*
+ * Converts "user" to "user=<username>".
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_optstr_fix_user(char **optstr)
+{
+	char *username;
+	struct libmnt_optloc ol;
+	int rc = 0;
+
+	DBG(CXT, ul_debug("fixing user"));
+
+	mnt_init_optloc(&ol);
+
+	rc = mnt_optstr_locate_option(*optstr, "user", &ol);
+	if (rc)
+		return rc == 1 ? 0 : rc;	/* 1: user= not found */
+
+	username = mnt_get_username(getuid());
+	if (!username)
+		return -ENOMEM;
+
+	if (!ol.valsz || (ol.value && strncmp(ol.value, username, ol.valsz) != 0)) {
+		if (ol.valsz)
+			/* remove old value */
+			mnt_optstr_remove_option_at(optstr, ol.value, ol.end);
+
+		rc = insert_value(optstr, ol.value ? ol.value : ol.end,
+				  username, NULL);
+	}
+
+	free(username);
+	return rc;
+}
+
+/**
+ * mnt_match_options:
+ * @optstr: options string
+ * @pattern: comma delimited list of options
+ *
+ * The "no" could be used for individual items in the @options list. The "no"
+ * prefix does not have a global meaning.
+ *
+ * Unlike fs type matching, nonetdev,user and nonetdev,nouser have
+ * DIFFERENT meanings; each option is matched explicitly as specified.
+ *
+ * The "no" prefix interpretation could be disabled by the "+" prefix, for example
+ * "+noauto" matches if @optstr literally contains the "noauto" string.
+ *
+ * "xxx,yyy,zzz" : "nozzz"	-> False
+ *
+ * "xxx,yyy,zzz" : "xxx,noeee"	-> True
+ *
+ * "bar,zzz"     : "nofoo"      -> True		(does not contain "foo")
+ *
+ * "nofoo,bar"   : "nofoo"      -> True		(does not contain "foo")
+ *
+ * "nofoo,bar"   : "+nofoo"     -> True		(contains "nofoo")
+ *
+ * "bar,zzz"     : "+nofoo"     -> False	(does not contain "nofoo")
+ *
+ *
+ * Returns: 1 if pattern is matching, else 0. This function also returns 0
+ *          if @pattern is NULL and @optstr is non-NULL.
+ */
+int mnt_match_options(const char *optstr, const char *pattern)
+{
+	char *name, *pat = (char *) pattern;
+	char *buf, *patval;
+	size_t namesz = 0, patvalsz = 0;
+	int match = 1;
+
+	if (!pattern && !optstr)
+		return 1;
+	if (!pattern)
+		return 0;
+
+	buf = malloc(strlen(pattern) + 1);
+	if (!buf)
+		return 0;
+
+	/* walk on pattern string
+	 */
+	while (match && !mnt_optstr_next_option(&pat, &name, &namesz,
+						&patval, &patvalsz)) {
+		char *val;
+		size_t sz;
+		int no = 0, rc;
+
+		if (*name == '+')
+			name++, namesz--;
+		else if ((no = (startswith(name, "no") != NULL)))
+			name += 2, namesz -= 2;
+
+		xstrncpy(buf, name, namesz + 1);
+
+		rc = mnt_optstr_get_option(optstr, buf, &val, &sz);
+
+		/* check also value (if the pattern is "foo=value") */
+		if (rc == 0 && patvalsz > 0 &&
+		    (patvalsz != sz || strncmp(patval, val, sz) != 0))
+			rc = 1;
+
+		switch (rc) {
+		case 0:		/* found */
+			match = no == 0 ? 1 : 0;
+			break;
+		case 1:		/* not found */
+			match = no == 1 ? 1 : 0;
+			break;
+		default:	/* parse error */
+			match = 0;
+			break;
+		}
+
+	}
+
+	free(buf);
+	return match;
+}
+
+#ifdef TEST_PROGRAM
+
+static int test_append(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *value = NULL, *name;
+	char *optstr;
+	int rc;
+
+	if (argc < 3)
+		return -EINVAL;
+	optstr = strdup(argv[1]);
+	name = argv[2];
+
+	if (argc == 4)
+		value = argv[3];
+
+	rc = mnt_optstr_append_option(&optstr, name, value);
+	if (!rc)
+		printf("result: >%s<\n", optstr);
+	free(optstr);
+	return rc;
+}
+
+static int test_prepend(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *value = NULL, *name;
+	char *optstr;
+	int rc;
+
+	if (argc < 3)
+		return -EINVAL;
+	optstr = strdup(argv[1]);
+	name = argv[2];
+
+	if (argc == 4)
+		value = argv[3];
+
+	rc = mnt_optstr_prepend_option(&optstr, name, value);
+	if (!rc)
+		printf("result: >%s<\n", optstr);
+	free(optstr);
+	return rc;
+}
+
+static int test_split(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr, *user = NULL, *fs = NULL, *vfs = NULL;
+	int rc;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	optstr = strdup(argv[1]);
+
+	rc = mnt_split_optstr(optstr, &user, &vfs, &fs, 0, 0);
+	if (!rc) {
+		printf("user : %s\n", user);
+		printf("vfs  : %s\n", vfs);
+		printf("fs   : %s\n", fs);
+	}
+
+	free(user);
+	free(vfs);
+	free(fs);
+	free(optstr);
+	return rc;
+}
+
+static int test_flags(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr;
+	int rc;
+	unsigned long fl = 0;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	optstr = strdup(argv[1]);
+
+	rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_LINUX_MAP));
+	if (rc)
+		return rc;
+	printf("mountflags:           0x%08lx\n", fl);
+
+	fl = 0;
+	rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
+	if (rc)
+		return rc;
+	printf("userspace-mountflags: 0x%08lx\n", fl);
+
+	free(optstr);
+	return rc;
+}
+
+static int test_apply(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr;
+	int rc, map;
+	unsigned long flags;
+
+	if (argc < 4)
+		return -EINVAL;
+
+	if (!strcmp(argv[1], "--user"))
+		map = MNT_USERSPACE_MAP;
+	else if (!strcmp(argv[1], "--linux"))
+		map = MNT_LINUX_MAP;
+	else {
+		fprintf(stderr, "unknown option '%s'\n", argv[1]);
+		return -EINVAL;
+	}
+
+	optstr = strdup(argv[2]);
+	flags = strtoul(argv[3], NULL, 16);
+
+	printf("flags:  0x%08lx\n", flags);
+
+	rc = mnt_optstr_apply_flags(&optstr, flags, mnt_get_builtin_optmap(map));
+	printf("optstr: %s\n", optstr);
+
+	free(optstr);
+	return rc;
+}
+
+static int test_set(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *value = NULL, *name;
+	char *optstr;
+	int rc;
+
+	if (argc < 3)
+		return -EINVAL;
+	optstr = strdup(argv[1]);
+	name = argv[2];
+
+	if (argc == 4)
+		value = argv[3];
+
+	rc = mnt_optstr_set_option(&optstr, name, value);
+	if (!rc)
+		printf("result: >%s<\n", optstr);
+	free(optstr);
+	return rc;
+}
+
+static int test_get(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr;
+	const char *name;
+	char *val = NULL;
+	size_t sz = 0;
+	int rc;
+
+	if (argc < 2)
+		return -EINVAL;
+	optstr = argv[1];
+	name = argv[2];
+
+	rc = mnt_optstr_get_option(optstr, name, &val, &sz);
+	if (rc == 0) {
+		printf("found; name: %s", name);
+		if (sz) {
+			printf(", argument: size=%zd data=", sz);
+			if (fwrite(val, 1, sz, stdout) != sz)
+				return -1;
+		}
+		printf("\n");
+	} else if (rc == 1)
+		printf("%s: not found\n", name);
+	else
+		printf("parse error: %s\n", optstr);
+	return rc;
+}
+
+static int test_remove(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *name;
+	char *optstr;
+	int rc;
+
+	if (argc < 3)
+		return -EINVAL;
+	optstr = strdup(argv[1]);
+	name = argv[2];
+
+	rc = mnt_optstr_remove_option(&optstr, name);
+	if (!rc)
+		printf("result: >%s<\n", optstr);
+	free(optstr);
+	return rc;
+}
+
+static int test_dedup(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *name;
+	char *optstr;
+	int rc;
+
+	if (argc < 3)
+		return -EINVAL;
+	optstr = strdup(argv[1]);
+	name = argv[2];
+
+	rc = mnt_optstr_deduplicate_option(&optstr, name);
+	if (!rc)
+		printf("result: >%s<\n", optstr);
+	free(optstr);
+	return rc;
+}
+
+static int test_fix(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr;
+	int rc = 0;
+	char *name, *val, *next;
+	size_t valsz, namesz;
+
+	if (argc < 2)
+		return -EINVAL;
+
+	next = optstr = strdup(argv[1]);
+
+	printf("optstr: %s\n", optstr);
+
+	while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
+
+		if (!strncmp(name, "uid", 3))
+			rc = mnt_optstr_fix_uid(&optstr, val, valsz, &next);
+		else if (!strncmp(name, "gid", 3))
+			rc = mnt_optstr_fix_gid(&optstr, val, valsz, &next);
+		else if (!strncmp(name, "context", 7))
+			rc = mnt_optstr_fix_secontext(&optstr, val, valsz, &next);
+		if (rc)
+			break;
+	}
+	if (rc)
+		rc = mnt_optstr_fix_user(&optstr);
+
+	printf("fixed:  %s\n", optstr);
+
+	free(optstr);
+	return rc;
+
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+		{ "--append", test_append, "<optstr> <name> [<value>]  append value to optstr" },
+		{ "--prepend",test_prepend,"<optstr> <name> [<value>]  prepend value to optstr" },
+		{ "--set",    test_set,    "<optstr> <name> [<value>]  (un)set value" },
+		{ "--get",    test_get,    "<optstr> <name>            search name in optstr" },
+		{ "--remove", test_remove, "<optstr> <name>            remove name in optstr" },
+		{ "--dedup",  test_dedup,  "<optstr> <name>            deduplicate name in optstr" },
+		{ "--split",  test_split,  "<optstr>                   split into FS, VFS and userspace" },
+		{ "--flags",  test_flags,  "<optstr>                   convert options to MS_* flags" },
+		{ "--apply",  test_apply,  "--{linux,user} <optstr> <mask>    apply mask to optstr" },
+		{ "--fix",    test_fix,    "<optstr>                   fix uid=, gid=, user, and context=" },
+
+		{ NULL }
+	};
+	return  mnt_run_test(tss, argc, argv);
+}
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/tab.c b/libmount/src/tab.c
new file mode 100644
index 0000000..e91254a
--- /dev/null
+++ b/libmount/src/tab.c
@@ -0,0 +1,2206 @@
+
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: table
+ * @title: Table of filesystems
+ * @short_description: container for entries from fstab, mtab or mountinfo
+ *
+ * Note that mnt_table_find_* functions are mount(8) compatible. These functions
+ * try to find an entry in more iterations, where the first attempt is always
+ * based on comparison with unmodified (non-canonicalized or un-evaluated)
+ * paths or tags. For example a fstab with two entries:
+ * <informalexample>
+ *   <programlisting>
+ *	LABEL=foo	/foo	auto   rw
+ *	/dev/foo	/foo	auto   rw
+ *  </programlisting>
+ * </informalexample>
+ *
+ * where both lines are used for the *same* device, then
+ * <informalexample>
+ *  <programlisting>
+ *	mnt_table_find_source(tb, "/dev/foo", &fs);
+ *  </programlisting>
+ * </informalexample>
+ * will returns the second line, and
+ * <informalexample>
+ *  <programlisting>
+ *	mnt_table_find_source(tb, "LABEL=foo", &fs);
+ *  </programlisting>
+ * </informalexample>
+ * will returns the first entry, and
+ * <informalexample>
+ *  <programlisting>
+ *	mnt_table_find_source(tb, "UUID=anyuuid", &fs);
+ *  </programlisting>
+ * </informalexample>
+ * will return the first entry (if UUID matches with the device).
+ */
+#include <blkid.h>
+
+#include "mountP.h"
+#include "strutils.h"
+#include "loopdev.h"
+#include "fileutils.h"
+#include "canonicalize.h"
+
+int is_mountinfo(struct libmnt_table *tb)
+{
+	struct libmnt_fs *fs;
+
+	if (!tb)
+		return 0;
+
+	fs = list_first_entry(&tb->ents, struct libmnt_fs, ents);
+	if (fs && mnt_fs_is_kernel(fs) && mnt_fs_get_root(fs))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * mnt_new_table:
+ *
+ * The tab is a container for struct libmnt_fs entries that usually represents a fstab,
+ * mtab or mountinfo file from your system.
+ *
+ * See also mnt_table_parse_file().
+ *
+ * Returns: newly allocated tab struct.
+ */
+struct libmnt_table *mnt_new_table(void)
+{
+	struct libmnt_table *tb = NULL;
+
+	tb = calloc(1, sizeof(*tb));
+	if (!tb)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "alloc"));
+	tb->refcount = 1;
+	INIT_LIST_HEAD(&tb->ents);
+	return tb;
+}
+
+/**
+ * mnt_reset_table:
+ * @tb: tab pointer
+ *
+ * Removes all entries (filesystems) from the table. The filesystems with zero
+ * reference count will be deallocated.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_reset_table(struct libmnt_table *tb)
+{
+	if (!tb)
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "reset"));
+
+	while (!list_empty(&tb->ents)) {
+		struct libmnt_fs *fs = list_entry(tb->ents.next,
+				                  struct libmnt_fs, ents);
+		mnt_table_remove_fs(tb, fs);
+	}
+
+	tb->nents = 0;
+	return 0;
+}
+
+/**
+ * mnt_ref_table:
+ * @tb: table pointer
+ *
+ * Increments reference counter.
+ */
+void mnt_ref_table(struct libmnt_table *tb)
+{
+	if (tb) {
+		tb->refcount++;
+		/*DBG(FS, ul_debugobj(tb, "ref=%d", tb->refcount));*/
+	}
+}
+
+/**
+ * mnt_unref_table:
+ * @tb: table pointer
+ *
+ * De-increments reference counter, on zero the @tb is automatically
+ * deallocated by mnt_free_table().
+ */
+void mnt_unref_table(struct libmnt_table *tb)
+{
+	if (tb) {
+		tb->refcount--;
+		/*DBG(FS, ul_debugobj(tb, "unref=%d", tb->refcount));*/
+		if (tb->refcount <= 0)
+			mnt_free_table(tb);
+	}
+}
+
+
+/**
+ * mnt_free_table:
+ * @tb: tab pointer
+ *
+ * Deallocates the table. This function does not care about reference count. Don't
+ * use this function directly -- it's better to use mnt_unref_table().
+ *
+ * The table entries (filesystems) are unreferenced by mnt_reset_table() and
+ * cache by mnt_unref_cache().
+ */
+void mnt_free_table(struct libmnt_table *tb)
+{
+	if (!tb)
+		return;
+
+	mnt_reset_table(tb);
+	DBG(TAB, ul_debugobj(tb, "free [refcount=%d]", tb->refcount));
+
+	mnt_unref_cache(tb->cache);
+	free(tb->comm_intro);
+	free(tb->comm_tail);
+	free(tb);
+}
+
+/**
+ * mnt_table_get_nents:
+ * @tb: pointer to tab
+ *
+ * Returns: number of entries in table.
+ */
+int mnt_table_get_nents(struct libmnt_table *tb)
+{
+	return tb ? tb->nents : 0;
+}
+
+/**
+ * mnt_table_is_empty:
+ * @tb: pointer to tab
+ *
+ * Returns: 1 if the table is without filesystems, or 0.
+ */
+int mnt_table_is_empty(struct libmnt_table *tb)
+{
+	return tb == NULL || list_empty(&tb->ents) ? 1 : 0;
+}
+
+/**
+ * mnt_table_set_userdata:
+ * @tb: pointer to tab
+ * @data: pointer to user data
+ *
+ * Sets pointer to the private user data.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_userdata(struct libmnt_table *tb, void *data)
+{
+	if (!tb)
+		return -EINVAL;
+
+	tb->userdata = data;
+	return 0;
+}
+
+/**
+ * mnt_table_get_userdata:
+ * @tb: pointer to tab
+ *
+ * Returns: pointer to user's data.
+ */
+void *mnt_table_get_userdata(struct libmnt_table *tb)
+{
+	return tb ? tb->userdata : NULL;
+}
+
+/**
+ * mnt_table_enable_comments:
+ * @tb: pointer to tab
+ * @enable: TRUE or FALSE
+ *
+ * Enables parsing of comments.
+ *
+ * The initial (intro) file comment is accessible by
+ * mnt_table_get_intro_comment(). The intro and the comment of the first fstab
+ * entry has to be separated by blank line.  The filesystem comments are
+ * accessible by mnt_fs_get_comment(). The trailing fstab comment is accessible
+ * by mnt_table_get_trailing_comment().
+ *
+ * <informalexample>
+ *  <programlisting>
+ *	#
+ *	# Intro comment
+ *	#
+ *
+ *	# this comments belongs to the first fs
+ *	LABEL=foo /mnt/foo auto defaults 1 2
+ *	# this comments belongs to the second fs
+ *	LABEL=bar /mnt/bar auto defaults 1 2
+ *	# tailing comment
+ *  </programlisting>
+ * </informalexample>
+ */
+void mnt_table_enable_comments(struct libmnt_table *tb, int enable)
+{
+	if (tb)
+		tb->comms = enable;
+}
+
+/**
+ * mnt_table_with_comments:
+ * @tb: pointer to table
+ *
+ * Returns: 1 if comments parsing is enabled, or 0.
+ */
+int mnt_table_with_comments(struct libmnt_table *tb)
+{
+	assert(tb);
+	return tb ? tb->comms : 0;
+}
+
+/**
+ * mnt_table_get_intro_comment:
+ * @tb: pointer to tab
+ *
+ * Returns: initial comment in tb
+ */
+const char *mnt_table_get_intro_comment(struct libmnt_table *tb)
+{
+	return tb ? tb->comm_intro : NULL;
+}
+
+/**
+ * mnt_table_set_into_comment:
+ * @tb: pointer to tab
+ * @comm: comment or NULL
+ *
+ * Sets the initial comment in tb.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_intro_comment(struct libmnt_table *tb, const char *comm)
+{
+	return strdup_to_struct_member(tb, comm_intro, comm);
+}
+
+/**
+ * mnt_table_append_into_comment:
+ * @tb: pointer to tab
+ * @comm: comment of NULL
+ *
+ * Appends the initial comment in tb.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_append_intro_comment(struct libmnt_table *tb, const char *comm)
+{
+	if (!tb)
+		return -EINVAL;
+	return append_string(&tb->comm_intro, comm);
+}
+
+/**
+ * mnt_table_get_trailing_comment:
+ * @tb: pointer to tab
+ *
+ * Returns: table trailing comment
+ */
+const char *mnt_table_get_trailing_comment(struct libmnt_table *tb)
+{
+	return tb ? tb->comm_tail : NULL;
+}
+
+/**
+ * mnt_table_set_trailing_comment
+ * @tb: pointer to tab
+ * @comm: comment string
+ *
+ * Sets the trailing comment in table.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_trailing_comment(struct libmnt_table *tb, const char *comm)
+{
+	return strdup_to_struct_member(tb, comm_tail, comm);
+}
+
+/**
+ * mnt_table_append_trailing_comment:
+ * @tb: pointer to tab
+ * @comm: comment of NULL
+ *
+ * Appends to the trailing table comment.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_append_trailing_comment(struct libmnt_table *tb, const char *comm)
+{
+	if (!tb)
+		return -EINVAL;
+	return append_string(&tb->comm_tail, comm);
+}
+
+/**
+ * mnt_table_set_cache:
+ * @tb: pointer to tab
+ * @mpc: pointer to struct libmnt_cache instance
+ *
+ * Sets up a cache for canonicalized paths and evaluated tags (LABEL/UUID). The
+ * cache is recommended for mnt_table_find_*() functions.
+ *
+ * The cache could be shared between more tabs. Be careful when you share the
+ * same cache between more threads -- currently the cache does not provide any
+ * locking method.
+ *
+ * This function increments cache reference counter. It's recommended to use
+ * mnt_unref_cache() after mnt_table_set_cache() if you want to keep the cache
+ * referenced by @tb only.
+ *
+ * See also mnt_new_cache().
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_cache(struct libmnt_table *tb, struct libmnt_cache *mpc)
+{
+	if (!tb)
+		return -EINVAL;
+
+	mnt_ref_cache(mpc);			/* new */
+	mnt_unref_cache(tb->cache);		/* old */
+	tb->cache = mpc;
+	return 0;
+}
+
+/**
+ * mnt_table_get_cache:
+ * @tb: pointer to tab
+ *
+ * Returns: pointer to struct libmnt_cache instance or NULL.
+ */
+struct libmnt_cache *mnt_table_get_cache(struct libmnt_table *tb)
+{
+	return tb ? tb->cache : NULL;
+}
+
+/**
+ * mnt_table_find_fs:
+ * @tb: tab pointer
+ * @fs: entry to look for
+ *
+ * Checks if @fs is part of table @tb.
+ *
+ * Returns: index of @fs in table, 0 if not found or negative number in case of error.
+ *
+ * Since: 2.34
+ */
+int mnt_table_find_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
+{
+	struct list_head *p;
+	int i = 0;
+
+	if (!tb || !fs)
+		return -EINVAL;
+
+	if (list_empty(&fs->ents))
+		return 0;
+
+	/* Let's use directly list rather than mnt_table_next_fs() as we
+	 * compare list entry with fs only.
+	 */
+	list_for_each(p, &tb->ents) {
+		++i;
+		if (list_entry(p, struct libmnt_fs, ents) == fs)
+			return i;
+	}
+
+	return 0;
+}
+
+/**
+ * mnt_table_add_fs:
+ * @tb: tab pointer
+ * @fs: new entry
+ *
+ * Adds a new entry to tab and increment @fs reference counter. Don't forget to
+ * use mnt_unref_fs() after mnt_table_add_fs() you want to keep the @fs
+ * referenced by the table only.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_add_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
+{
+	if (!tb || !fs)
+		return -EINVAL;
+
+	if (fs->tab)
+		return -EBUSY;
+
+	mnt_ref_fs(fs);
+	list_add_tail(&fs->ents, &tb->ents);
+	fs->tab = tb;
+	tb->nents++;
+
+	DBG(TAB, ul_debugobj(tb, "add entry: %s %s",
+			mnt_fs_get_source(fs), mnt_fs_get_target(fs)));
+	return 0;
+}
+
+static int __table_insert_fs(
+			struct libmnt_table *tb, int before,
+			struct libmnt_fs *pos, struct libmnt_fs *fs)
+{
+	struct list_head *head = pos ? &pos->ents : &tb->ents;
+
+	if (before)
+		list_add(&fs->ents, head);
+	else
+		list_add_tail(&fs->ents, head);
+
+	fs->tab = tb;
+	tb->nents++;
+
+	DBG(TAB, ul_debugobj(tb, "insert entry: %s %s",
+			mnt_fs_get_source(fs), mnt_fs_get_target(fs)));
+	return 0;
+}
+
+/**
+ * mnt_table_insert_fs:
+ * @tb: tab pointer
+ * @before: 1 to insert before pos, 0 to insert after pos
+ * @pos: entry to specify position or NULL
+ * @fs: new entry
+ *
+ * Adds a new entry to @tb before or after a specific table entry @pos. If the
+ * @pos is NULL than add the begin of the @tab if @before is 1; or to the tail
+ * of the @tb if @before is 0.
+ *
+ * This function increments reference to @fs. Don't forget to use
+ * mnt_unref_fs() after mnt_table_insert_fs() if you want to keep the @fs
+ * referenced by the table only.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ *
+ * Since: 2.34
+ */
+int mnt_table_insert_fs(struct libmnt_table *tb, int before,
+			struct libmnt_fs *pos, struct libmnt_fs *fs)
+{
+	if (!tb || !fs)
+		return -EINVAL;
+
+	if (fs->tab)
+		return -EBUSY;
+
+	if (pos && pos->tab != tb)
+		return -ENOENT;
+
+	mnt_ref_fs(fs);
+	return __table_insert_fs(tb, before, pos, fs);
+}
+
+/**
+ * mnt_table_move_fs:
+ * @src: tab pointer of source table
+ * @dst: tab pointer of destination table
+ * @before: 1 to move before position, 0 to move after position
+ * @pos: entry to specify position or NULL
+ * @fs: entry to move
+ *
+ * Removes @fs from @src table and adds it before/after a specific entry @pos
+ * of @dst table. If the @pos is NULL than add the begin of the @dst if @before
+ * is 1; or to the tail of the @dst if @before is 0.
+ *
+ * The reference counter of @fs is not modified.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ *
+ * Since: 2.34
+ */
+int mnt_table_move_fs(struct libmnt_table *src, struct libmnt_table *dst,
+                      int before, struct libmnt_fs *pos, struct libmnt_fs *fs)
+{
+	if (!src || !dst || !fs)
+		return -EINVAL;
+
+	if (fs->tab != src || (pos && pos->tab != dst))
+		return -ENOENT;
+
+	/* remove from source */
+	list_del_init(&fs->ents);
+	src->nents--;
+
+	/* insert to the destination */
+	return __table_insert_fs(dst, before, pos, fs);
+}
+
+
+/**
+ * mnt_table_remove_fs:
+ * @tb: tab pointer
+ * @fs: new entry
+ *
+ * Removes the @fs from the table and de-increment reference counter of the @fs. The
+ * filesystem with zero reference counter will be deallocated. Don't forget to use
+ * mnt_ref_fs() before call mnt_table_remove_fs() if you want to use @fs later.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_remove_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
+{
+	if (!tb || !fs || fs->tab != tb)
+		return -EINVAL;
+
+	fs->tab = NULL;
+	list_del_init(&fs->ents);
+
+	mnt_unref_fs(fs);
+	tb->nents--;
+	return 0;
+}
+
+static inline struct libmnt_fs *get_parent_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *x;
+	int parent_id = mnt_fs_get_parent_id(fs);
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while (mnt_table_next_fs(tb, &itr, &x) == 0) {
+		if (mnt_fs_get_id(x) == parent_id)
+			return x;
+	}
+
+	return NULL;
+}
+
+/**
+ * mnt_table_get_root_fs:
+ * @tb: mountinfo file (/proc/self/mountinfo)
+ * @root: returns pointer to the root filesystem (/)
+ *
+ * The function uses the parent ID from the mountinfo file to determine the
+ * root filesystem (the filesystem with the smallest ID with parent ID missing
+ * in the table). The function is designed mostly for applications where it is
+ * necessary to sort mountpoints by IDs to get the tree of the mountpoints
+ * (e.g. findmnt default output).
+ *
+ * If you're not sure, then use
+ *
+ *	mnt_table_find_target(tb, "/", MNT_ITER_BACKWARD);
+ *
+ * this is more robust and usable for arbitrary tab files (including fstab).
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_get_root_fs(struct libmnt_table *tb, struct libmnt_fs **root)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+	int root_id = 0;
+
+	if (!tb || !root || !is_mountinfo(tb))
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup root fs"));
+
+	*root = NULL;
+
+	/* get smallest possible ID from the table */
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		int id = mnt_fs_get_parent_id(fs);
+
+		if (!*root || id < root_id) {
+			*root = fs;
+			root_id = id;
+		}
+	}
+
+	/* go to the root node by "parent_id -> id" relation */
+	while (*root) {
+		struct libmnt_fs *x = get_parent_fs(tb, *root);
+		if (!x || x == *root)
+			break;
+		DBG(TAB, ul_debugobj(tb, " messy mountinfo, walk to %s", mnt_fs_get_target(x)));
+		*root = x;
+	}
+
+	return *root ? 0 : -EINVAL;
+}
+
+/**
+ * mnt_table_next_child_fs:
+ * @tb: mountinfo file (/proc/self/mountinfo)
+ * @itr: iterator
+ * @parent: parental FS
+ * @chld: returns the next child filesystem
+ *
+ * Note that filesystems are returned in the order of mounting (according to
+ * IDs in /proc/self/mountinfo).
+ *
+ * Returns: 0 on success, negative number in case of error or 1 at the end of list.
+ */
+int mnt_table_next_child_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
+			struct libmnt_fs *parent, struct libmnt_fs **chld)
+{
+	struct libmnt_fs *fs;
+	int parent_id, lastchld_id = 0, chld_id = 0;
+
+	if (!tb || !itr || !parent || !is_mountinfo(tb))
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup next child of '%s'",
+				mnt_fs_get_target(parent)));
+
+	parent_id = mnt_fs_get_id(parent);
+
+	/* get ID of the previously returned child */
+	if (itr->head && itr->p != itr->head) {
+		MNT_ITER_ITERATE(itr, fs, struct libmnt_fs, ents);
+		lastchld_id = mnt_fs_get_id(fs);
+	}
+
+	*chld = NULL;
+
+	mnt_reset_iter(itr, MNT_ITER_FORWARD);
+	while(mnt_table_next_fs(tb, itr, &fs) == 0) {
+		int id;
+
+		if (mnt_fs_get_parent_id(fs) != parent_id)
+			continue;
+
+		id = mnt_fs_get_id(fs);
+
+		/* avoid an infinite loop. This only happens in rare cases
+		 * such as in early userspace when the rootfs is its own parent */
+		if (id == parent_id)
+			continue;
+
+		if ((!lastchld_id || id > lastchld_id) &&
+		    (!*chld || id < chld_id)) {
+			*chld = fs;
+			chld_id = id;
+		}
+	}
+
+	if (!*chld)
+		return 1;	/* end of iterator */
+
+	/* set the iterator to the @chld for the next call */
+	mnt_table_set_iter(tb, itr, *chld);
+
+	return 0;
+}
+
+/**
+ * mnt_table_next_fs:
+ * @tb: tab pointer
+ * @itr: iterator
+ * @fs: returns the next tab entry
+ *
+ * Returns: 0 on success, negative number in case of error or 1 at the end of list.
+ *
+ * Example:
+ * <informalexample>
+ *   <programlisting>
+ *	while(mnt_table_next_fs(tb, itr, &fs) == 0) {
+ *		const char *dir = mnt_fs_get_target(fs);
+ *		printf("mount point: %s\n", dir);
+ *	}
+ *   </programlisting>
+ * </informalexample>
+ *
+ * lists all mountpoints from fstab in reverse order.
+ */
+int mnt_table_next_fs(struct libmnt_table *tb, struct libmnt_iter *itr, struct libmnt_fs **fs)
+{
+	int rc = 1;
+
+	if (!tb || !itr || !fs)
+		return -EINVAL;
+	*fs = NULL;
+
+	if (!itr->head)
+		MNT_ITER_INIT(itr, &tb->ents);
+	if (itr->p != itr->head) {
+		MNT_ITER_ITERATE(itr, *fs, struct libmnt_fs, ents);
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/**
+ * mnt_table_first_fs:
+ * @tb: tab pointer
+ * @fs: returns the first tab entry
+ *
+ * Returns: 0 on success, negative number in case of error or 1 at the end of list.
+ */
+int mnt_table_first_fs(struct libmnt_table *tb, struct libmnt_fs **fs)
+{
+	if (!tb || !fs)
+		return -EINVAL;
+	if (list_empty(&tb->ents))
+		return 1;
+	*fs = list_first_entry(&tb->ents, struct libmnt_fs, ents);
+	return 0;
+}
+
+/**
+ * mnt_table_last_fs:
+ * @tb: tab pointer
+ * @fs: returns the last tab entry
+ *
+ * Returns: 0 on success, negative number in case of error or 1 at the end of list.
+ */
+int mnt_table_last_fs(struct libmnt_table *tb, struct libmnt_fs **fs)
+{
+	if (!tb || !fs)
+		return -EINVAL;
+	if (list_empty(&tb->ents))
+		return 1;
+	*fs = list_last_entry(&tb->ents, struct libmnt_fs, ents);
+	return 0;
+}
+
+/**
+ * mnt_table_find_next_fs:
+ * @tb: table
+ * @itr: iterator
+ * @match_func: function returning 1 or 0
+ * @userdata: extra data for match_func
+ * @fs: returns pointer to the next matching table entry
+ *
+ * This function allows searching in @tb.
+ *
+ * Returns: negative number in case of error, 1 at end of table or 0 o success.
+ */
+int mnt_table_find_next_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
+		int (*match_func)(struct libmnt_fs *, void *), void *userdata,
+		struct libmnt_fs **fs)
+{
+	if (!tb || !itr || !fs || !match_func)
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup next fs"));
+
+	if (!itr->head)
+		MNT_ITER_INIT(itr, &tb->ents);
+
+	do {
+		if (itr->p != itr->head)
+			MNT_ITER_ITERATE(itr, *fs, struct libmnt_fs, ents);
+		else
+			break;			/* end */
+
+		if (match_func(*fs, userdata))
+			return 0;
+	} while(1);
+
+	*fs = NULL;
+	return 1;
+}
+
+static int mnt_table_move_parent(struct libmnt_table *tb, int oldid, int newid)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+
+	if (!tb)
+		return -EINVAL;
+	if (list_empty(&tb->ents))
+		return 0;
+
+	DBG(TAB, ul_debugobj(tb, "moving parent ID from %d -> %d", oldid, newid));
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (fs->parent == oldid)
+			fs->parent = newid;
+	}
+	return 0;
+}
+
+/**
+ * mnt_table_uniq_fs:
+ * @tb: table
+ * @flags: MNT_UNIQ_*
+ * @cmp: function to compare filesystems
+ *
+ * This function de-duplicate the @tb, but does not change order of the
+ * filesystems. The @cmp function has to return 0 if the filesystems are
+ * equal, otherwise non-zero.
+ *
+ * The default is to keep in the table later mounted filesystems (function uses
+ * backward mode iterator).
+ *
+ * @MNT_UNIQ_FORWARD:  remove later mounted filesystems
+ * @MNT_UNIQ_KEEPTREE: keep parent->id relationship still valid
+ *
+ * Returns: negative number in case of error, or 0 o success.
+ */
+int mnt_table_uniq_fs(struct libmnt_table *tb, int flags,
+				int (*cmp)(struct libmnt_table *,
+					   struct libmnt_fs *,
+					   struct libmnt_fs *))
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+	int direction = MNT_ITER_BACKWARD;
+
+	if (!tb || !cmp)
+		return -EINVAL;
+	if (list_empty(&tb->ents))
+		return 0;
+
+	if (flags & MNT_UNIQ_FORWARD)
+		direction = MNT_ITER_FORWARD;
+
+	DBG(TAB, ul_debugobj(tb, "de-duplicate"));
+	mnt_reset_iter(&itr, direction);
+
+	if ((flags & MNT_UNIQ_KEEPTREE) && !is_mountinfo(tb))
+		flags &= ~MNT_UNIQ_KEEPTREE;
+
+	while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		int want = 1;
+		struct libmnt_iter xtr;
+		struct libmnt_fs *x;
+
+		mnt_reset_iter(&xtr, direction);
+		while (want && mnt_table_next_fs(tb, &xtr, &x) == 0) {
+			if (fs == x)
+				break;
+			want = cmp(tb, x, fs) != 0;
+		}
+
+		if (!want) {
+			if (flags & MNT_UNIQ_KEEPTREE)
+				mnt_table_move_parent(tb, mnt_fs_get_id(fs),
+							  mnt_fs_get_parent_id(fs));
+
+			DBG(TAB, ul_debugobj(tb, "remove duplicate %s",
+						mnt_fs_get_target(fs)));
+			mnt_table_remove_fs(tb, fs);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * mnt_table_set_iter:
+ * @tb: tab pointer
+ * @itr: iterator
+ * @fs: tab entry
+ *
+ * Sets @iter to the position of @fs in the file @tb.
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_table_set_iter(struct libmnt_table *tb, struct libmnt_iter *itr, struct libmnt_fs *fs)
+{
+	if (!tb || !itr || !fs)
+		return -EINVAL;
+
+	if (fs->tab != tb)
+		return -ENOENT;
+
+	MNT_ITER_INIT(itr, &tb->ents);
+	itr->p = &fs->ents;
+
+	return 0;
+}
+
+/**
+ * mnt_table_find_mountpoint:
+ * @tb: tab pointer
+ * @path: directory
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Same as mnt_get_mountpoint(), except this function does not rely on
+ * st_dev numbers.
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_mountpoint(struct libmnt_table *tb,
+					    const char *path,
+					    int direction)
+{
+	char *mnt;
+	struct stat st;
+
+	if (!tb || !path || !*path)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup MOUNTPOINT: '%s'", path));
+
+	if (mnt_stat_mountpoint(path, &st))
+		return NULL;
+
+	mnt = strdup(path);
+	if (!mnt)
+		return NULL;
+
+	do {
+		char *p;
+		struct libmnt_fs *fs;
+
+		fs = mnt_table_find_target(tb, mnt, direction);
+		if (fs) {
+			free(mnt);
+			return fs;
+		}
+
+		p = stripoff_last_component(mnt);
+		if (!p)
+			break;
+	} while (mnt && *(mnt + 1) != '\0');
+
+	free(mnt);
+	return mnt_table_find_target(tb, "/", direction);
+}
+
+/**
+ * mnt_table_find_target:
+ * @tb: tab pointer
+ * @path: mountpoint directory
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Try to lookup an entry in the given tab, three iterations are possible, the first
+ * with @path, the second with realpath(@path) and the third with realpath(@path)
+ * against realpath(fs->target). The 2nd and 3rd iterations are not performed when
+ * the @tb cache is not set (see mnt_table_set_cache()). If
+ * mnt_cache_set_targets(cache, mtab) was called, the 3rd iteration skips any
+ * @fs->target found in @mtab (see mnt_resolve_target()).
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_target(struct libmnt_table *tb, const char *path, int direction)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs = NULL;
+	char *cn;
+
+	if (!tb || !path || !*path)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup TARGET: '%s'", path));
+
+	/* native @target */
+	mnt_reset_iter(&itr, direction);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (mnt_fs_streq_target(fs, path))
+			return fs;
+	}
+
+	/* try absolute path */
+	if (is_relative_path(path) && (cn = absolute_path(path))) {
+		DBG(TAB, ul_debugobj(tb, "lookup absolute TARGET: '%s'", cn));
+		mnt_reset_iter(&itr, direction);
+		while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+			if (mnt_fs_streq_target(fs, cn)) {
+				free(cn);
+				return fs;
+			}
+		}
+		free(cn);
+	}
+
+	if (!tb->cache || !(cn = mnt_resolve_path(path, tb->cache)))
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup canonical TARGET: '%s'", cn));
+
+	/* canonicalized paths in struct libmnt_table */
+	mnt_reset_iter(&itr, direction);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (mnt_fs_streq_target(fs, cn))
+			return fs;
+	}
+
+	/* non-canonical path in struct libmnt_table
+	 * -- note that mountpoint in /proc/self/mountinfo is already
+	 *    canonicalized by the kernel
+	 */
+	mnt_reset_iter(&itr, direction);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		char *p;
+
+		if (!fs->target
+		    || mnt_fs_is_swaparea(fs)
+		    || mnt_fs_is_kernel(fs)
+		    || (*fs->target == '/' && *(fs->target + 1) == '\0'))
+		       continue;
+
+		p = mnt_resolve_target(fs->target, tb->cache);
+		/* both canonicalized, strcmp() is fine here */
+		if (p && strcmp(cn, p) == 0)
+			return fs;
+	}
+	return NULL;
+}
+
+/**
+ * mnt_table_find_srcpath:
+ * @tb: tab pointer
+ * @path: source path (devname or dirname) or NULL
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Try to lookup an entry in the given tab, four iterations are possible, the first
+ * with @path, the second with realpath(@path), the third with tags (LABEL, UUID, ..)
+ * from @path and the fourth with realpath(@path) against realpath(entry->srcpath).
+ *
+ * The 2nd, 3rd and 4th iterations are not performed when the @tb cache is not
+ * set (see mnt_table_set_cache()).
+ *
+ * For btrfs returns tab entry for default id.
+ *
+ * Note that NULL is a valid source path; it will be replaced with "none". The
+ * "none" is used in /proc/{mounts,self/mountinfo} for pseudo filesystems.
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb, const char *path, int direction)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs = NULL;
+	int ntags = 0, nents;
+	char *cn;
+	const char *p;
+
+	if (!tb || !path || !*path)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup SRCPATH: '%s'", path));
+
+	/* native paths */
+	mnt_reset_iter(&itr, direction);
+
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+
+		if (mnt_fs_streq_srcpath(fs, path)) {
+#ifdef HAVE_BTRFS_SUPPORT
+			if (fs->fstype && !strcmp(fs->fstype, "btrfs")) {
+				uint64_t default_id = btrfs_get_default_subvol_id(mnt_fs_get_target(fs));
+				char *val;
+				size_t len;
+
+				if (default_id == UINT64_MAX)
+					DBG(TAB, ul_debug("not found btrfs volume setting"));
+
+				else if (mnt_fs_get_option(fs, "subvolid", &val, &len) == 0) {
+					uint64_t subvol_id;
+
+					if (mnt_parse_offset(val, len, &subvol_id)) {
+						DBG(TAB, ul_debugobj(tb, "failed to parse subvolid="));
+						continue;
+					}
+					if (subvol_id != default_id)
+						continue;
+				}
+			}
+#endif /* HAVE_BTRFS_SUPPORT */
+			return fs;
+		}
+		if (mnt_fs_get_tag(fs, NULL, NULL) == 0)
+			ntags++;
+	}
+
+	if (!path || !tb->cache || !(cn = mnt_resolve_path(path, tb->cache)))
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup canonical SRCPATH: '%s'", cn));
+
+	nents = mnt_table_get_nents(tb);
+
+	/* canonicalized paths in struct libmnt_table */
+	if (ntags < nents) {
+		mnt_reset_iter(&itr, direction);
+		while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+			if (mnt_fs_streq_srcpath(fs, cn))
+				return fs;
+		}
+	}
+
+	/* evaluated tag */
+	if (ntags) {
+		int rc = mnt_cache_read_tags(tb->cache, cn);
+
+		mnt_reset_iter(&itr, direction);
+
+		if (rc == 0) {
+			/* @path's TAGs are in the cache */
+			while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+				const char *t, *v;
+
+				if (mnt_fs_get_tag(fs, &t, &v))
+					continue;
+
+				if (mnt_cache_device_has_tag(tb->cache, cn, t, v))
+					return fs;
+			}
+		} else if (rc < 0 && errno == EACCES) {
+			/* @path is inaccessible, try evaluating all TAGs in @tb
+			 * by udev symlinks -- this could be expensive on systems
+			 * with a huge fstab/mtab */
+			 while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+				 const char *t, *v, *x;
+				 if (mnt_fs_get_tag(fs, &t, &v))
+					 continue;
+				 x = mnt_resolve_tag(t, v, tb->cache);
+
+				 /* both canonicalized, strcmp() is fine here */
+				 if (x && strcmp(x, cn) == 0)
+					 return fs;
+			 }
+		}
+	}
+
+	/* non-canonicalized paths in struct libmnt_table */
+	if (ntags <= nents) {
+		mnt_reset_iter(&itr, direction);
+		while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+			if (mnt_fs_is_netfs(fs) || mnt_fs_is_pseudofs(fs))
+				continue;
+			p = mnt_fs_get_srcpath(fs);
+			if (p)
+				p = mnt_resolve_path(p, tb->cache);
+
+			/* both canonicalized, strcmp() is fine here */
+			if (p && strcmp(p, cn) == 0)
+				return fs;
+		}
+	}
+
+	return NULL;
+}
+
+
+/**
+ * mnt_table_find_tag:
+ * @tb: tab pointer
+ * @tag: tag name (e.g "LABEL", "UUID", ...)
+ * @val: tag value
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Try to lookup an entry in the given tab, the first attempt is to lookup by @tag and
+ * @val, for the second attempt the tag is evaluated (converted to the device
+ * name) and mnt_table_find_srcpath() is performed. The second attempt is not
+ * performed when @tb cache is not set (see mnt_table_set_cache()).
+
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_tag(struct libmnt_table *tb, const char *tag,
+			const char *val, int direction)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs = NULL;
+
+	if (!tb || !tag || !*tag || !val)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup by TAG: %s %s", tag, val));
+
+	/* look up by TAG */
+	mnt_reset_iter(&itr, direction);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (fs->tagname && fs->tagval &&
+		    strcmp(fs->tagname, tag) == 0 &&
+		    strcmp(fs->tagval, val) == 0)
+			return fs;
+	}
+
+	if (tb->cache) {
+		/* look up by device name */
+		char *cn = mnt_resolve_tag(tag, val, tb->cache);
+		if (cn)
+			return mnt_table_find_srcpath(tb, cn, direction);
+	}
+	return NULL;
+}
+
+/**
+ * mnt_table_find_target_with_option:
+ * @tb: tab pointer
+ * @path: mountpoint directory
+ * @option: option name (e.g "subvol", "subvolid", ...)
+ * @val: option value or NULL
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Try to lookup an entry in the given tab that matches combination of @path
+ * and @option. In difference to mnt_table_find_target(), only @path iteration
+ * is done. No lookup by device name, no canonicalization.
+ *
+ * Returns: a tab entry or NULL.
+ *
+ * Since: 2.28
+ */
+struct libmnt_fs *mnt_table_find_target_with_option(
+			struct libmnt_table *tb, const char *path,
+			const char *option, const char *val, int direction)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs = NULL;
+	char *optval = NULL;
+	size_t optvalsz = 0, valsz = val ? strlen(val) : 0;
+
+	if (!tb || !path || !*path || !option || !*option || !val)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup TARGET: '%s' with OPTION %s %s", path, option, val));
+
+	/* look up by native @target with OPTION */
+	mnt_reset_iter(&itr, direction);
+	while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (mnt_fs_streq_target(fs, path)
+		    && mnt_fs_get_option(fs, option, &optval, &optvalsz) == 0
+		    && (!val || (optvalsz == valsz
+				 && strncmp(optval, val, optvalsz) == 0)))
+			return fs;
+	}
+	return NULL;
+}
+
+/**
+ * mnt_table_find_source:
+ * @tb: tab pointer
+ * @source: TAG or path
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * This is a high-level API for mnt_table_find_{srcpath,tag}. You needn't care
+ * about the @source format (device, LABEL, UUID, ...). This function parses
+ * the @source and calls mnt_table_find_tag() or mnt_table_find_srcpath().
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_source(struct libmnt_table *tb,
+					const char *source, int direction)
+{
+	struct libmnt_fs *fs;
+	char *t = NULL, *v = NULL;
+
+	if (!tb)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup SOURCE: '%s'", source));
+
+	if (blkid_parse_tag_string(source, &t, &v) || !mnt_valid_tagname(t))
+		fs = mnt_table_find_srcpath(tb, source, direction);
+	else
+		fs = mnt_table_find_tag(tb, t, v, direction);
+
+	free(t);
+	free(v);
+
+	return fs;
+}
+
+/**
+ * mnt_table_find_pair
+ * @tb: tab pointer
+ * @source: TAG or path
+ * @target: mountpoint
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * This function is implemented by mnt_fs_match_source() and
+ * mnt_fs_match_target() functions. It means that this is more expensive than
+ * others mnt_table_find_* function, because every @tab entry is fully evaluated.
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_pair(struct libmnt_table *tb, const char *source,
+				      const char *target, int direction)
+{
+	struct libmnt_fs *fs = NULL;
+	struct libmnt_iter itr;
+
+	if (!tb || !target || !*target || !source || !*source)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup SOURCE: %s TARGET: %s", source, target));
+
+	mnt_reset_iter(&itr, direction);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+
+		if (mnt_fs_match_target(fs, target, tb->cache) &&
+		    mnt_fs_match_source(fs, source, tb->cache))
+			return fs;
+	}
+
+	return NULL;
+}
+
+/**
+ * mnt_table_find_devno
+ * @tb: /proc/self/mountinfo
+ * @devno: device number
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * Note that zero could be a valid device number for the root pseudo filesystem (e.g.
+ * tmpfs).
+ *
+ * Returns: a tab entry or NULL.
+ */
+struct libmnt_fs *mnt_table_find_devno(struct libmnt_table *tb,
+				       dev_t devno, int direction)
+{
+	struct libmnt_fs *fs = NULL;
+	struct libmnt_iter itr;
+
+	if (!tb)
+		return NULL;
+	if (direction != MNT_ITER_FORWARD && direction != MNT_ITER_BACKWARD)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "lookup DEVNO: %d", (int) devno));
+
+	mnt_reset_iter(&itr, direction);
+
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		if (mnt_fs_get_devno(fs) == devno)
+			return fs;
+	}
+
+	return NULL;
+}
+
+static char *remove_mountpoint_from_path(const char *path, const char *mnt)
+{
+        char *res;
+	const char *p;
+	size_t sz;
+
+	sz = strlen(mnt);
+	p = sz > 1 ? path + sz : path;
+
+	res = *p ? strdup(p) : strdup("/");
+	DBG(UTILS, ul_debug("%s fs-root is %s", path, res));
+	return res;
+}
+
+#ifdef HAVE_BTRFS_SUPPORT
+static int get_btrfs_fs_root(struct libmnt_table *tb, struct libmnt_fs *fs, char **root)
+{
+	char *vol = NULL, *p;
+	size_t sz, volsz = 0;
+
+	DBG(BTRFS, ul_debug("lookup for btrfs FS root"));
+	*root = NULL;
+
+	if (mnt_fs_get_option(fs, "subvolid", &vol, &volsz) == 0) {
+		char *target;
+		struct libmnt_fs *f;
+		char subvolidstr[sizeof(stringify_value(UINT64_MAX))];
+
+		DBG(BTRFS, ul_debug(" found subvolid=%s, checking", vol));
+
+		assert (volsz + 1 < sizeof(stringify_value(UINT64_MAX)));
+		memcpy(subvolidstr, vol, volsz);
+		subvolidstr[volsz] = '\0';
+
+		target = mnt_resolve_target(mnt_fs_get_target(fs), tb->cache);
+		if (!target)
+			goto err;
+
+		DBG(BTRFS, ul_debug(" trying target=%s subvolid=%s", target, subvolidstr));
+		f = mnt_table_find_target_with_option(tb, target,
+					"subvolid", subvolidstr,
+					MNT_ITER_BACKWARD);
+		if (!tb->cache)
+			free(target);
+		if (!f)
+			goto not_found;
+
+		/* Instead of set of BACKREF queries constructing subvol path
+		 * corresponding to a particular subvolid, use the one in
+		 * mountinfo. Kernel keeps subvol path up to date.
+		 */
+		if (mnt_fs_get_option(f, "subvol", &vol, &volsz) != 0)
+			goto not_found;
+
+	} else if (mnt_fs_get_option(fs, "subvol", &vol, &volsz) != 0) {
+		/* If fstab entry does not contain "subvol", we have to
+		 * check, whether btrfs has default subvolume defined.
+		 */
+		uint64_t default_id;
+		char *target;
+		struct libmnt_fs *f;
+		char default_id_str[sizeof(stringify_value(UINT64_MAX))];
+
+		DBG(BTRFS, ul_debug(" subvolid/subvol not found, checking default"));
+
+		default_id = btrfs_get_default_subvol_id(mnt_fs_get_target(fs));
+		if (default_id == UINT64_MAX)
+			goto not_found;
+
+		/* Volume has default subvolume. Check if it matches to
+		 * the one in mountinfo.
+		 *
+		 * Only kernel >= 4.2 reports subvolid. On older
+		 * kernels, there is no reasonable way to detect which
+		 * subvolume was mounted.
+		 */
+		target = mnt_resolve_target(mnt_fs_get_target(fs), tb->cache);
+		if (!target)
+			goto err;
+
+		snprintf(default_id_str, sizeof(default_id_str), "%llu",
+				(unsigned long long int) default_id);
+
+		DBG(BTRFS, ul_debug(" trying target=%s default subvolid=%s",
+					target, default_id_str));
+
+		f = mnt_table_find_target_with_option(tb, target,
+					"subvolid", default_id_str,
+					MNT_ITER_BACKWARD);
+		if (!tb->cache)
+			free(target);
+		if (!f)
+			goto not_found;
+
+		/* Instead of set of BACKREF queries constructing
+		 * subvol path, use the one in mountinfo. Kernel does
+		 * the evaluation for us.
+		 */
+		DBG(BTRFS, ul_debug("setting FS root: btrfs default subvolid = %s",
+					default_id_str));
+
+		if (mnt_fs_get_option(f, "subvol", &vol, &volsz) != 0)
+			goto not_found;
+	}
+
+	DBG(BTRFS, ul_debug(" using subvol=%s", vol));
+	sz = volsz;
+	if (*vol != '/')
+		sz++;
+	*root = malloc(sz + 1);
+	if (!*root)
+		goto err;
+	p = *root;
+	if (*vol != '/')
+		*p++ = '/';
+	memcpy(p, vol, volsz);
+	*(*root + sz) = '\0';
+	return 0;
+
+not_found:
+	DBG(BTRFS, ul_debug(" not found btrfs volume setting"));
+	return 1;
+err:
+	DBG(BTRFS, ul_debug(" error on btrfs volume setting evaluation"));
+	return errno ? -errno : -1;
+}
+#endif /* HAVE_BTRFS_SUPPORT */
+
+static const char *get_cifs_unc_subdir_path (const char *unc)
+{
+	/*
+	 *  1 or more slash:     %*[/]
+	 *  1 or more non-slash: %*[^/]
+	 *  number of byte read: %n
+	 */
+	int share_end = 0;
+	int r = sscanf(unc, "%*[/]%*[^/]%*[/]%*[^/]%n", &share_end);
+	if (r == EOF || share_end == 0)
+		return NULL;
+	return unc + share_end;
+}
+
+/*
+ * tb: /proc/self/mountinfo
+ * fs: filesystem
+ * mountflags: MS_BIND or 0
+ * fsroot: fs-root that will probably be used in the mountinfo file
+ *          for @fs after mount(2)
+ *
+ * For btrfs subvolumes this function returns NULL, but @fsroot properly set.
+ *
+ * If @tb is NULL then defaults to '/'.
+ *
+ * Returns: entry from @tb that will be used as a source for @fs if the @fs is
+ *          bindmount.
+ *
+ * Don't export to library API!
+ */
+struct libmnt_fs *mnt_table_get_fs_root(struct libmnt_table *tb,
+					struct libmnt_fs *fs,
+					unsigned long mountflags,
+					char **fsroot)
+{
+	char *root = NULL;
+	const char *mnt = NULL;
+	struct libmnt_fs *src_fs = NULL;
+
+	assert(fs);
+	assert(fsroot);
+
+	DBG(TAB, ul_debug("lookup fs-root for '%s'", mnt_fs_get_source(fs)));
+
+	if (tb && (mountflags & MS_BIND)) {
+		const char *src, *src_root;
+		char *xsrc = NULL;
+
+		DBG(TAB, ul_debug("fs-root for bind"));
+
+		src = xsrc = mnt_resolve_spec(mnt_fs_get_source(fs), tb->cache);
+		if (src) {
+			struct libmnt_fs *f = mnt_table_find_mountpoint(tb,
+							src, MNT_ITER_BACKWARD);
+			if (f)
+				mnt = mnt_fs_get_target(f);
+		}
+		if (mnt)
+			root = remove_mountpoint_from_path(src, mnt);
+
+		if (xsrc && !tb->cache) {
+			free(xsrc);
+			src = NULL;
+		}
+		if (!mnt)
+			goto err;
+
+		src_fs = mnt_table_find_target(tb, mnt, MNT_ITER_BACKWARD);
+		if (!src_fs)  {
+			DBG(TAB, ul_debug("not found '%s' in mountinfo -- using default", mnt));
+			goto dflt;
+		}
+
+		/* It's possible that fstab_fs source is subdirectory on btrfs
+		 * subvolume or another bind mount. For example:
+		 *
+		 * /dev/sdc        /mnt/test       btrfs   subvol=/anydir
+		 * /dev/sdc        /mnt/test       btrfs   defaults
+		 * /mnt/test/foo   /mnt/test2      auto    bind
+		 *
+		 * in this case, the root for /mnt/test2 will be /anydir/foo on
+		 * /dev/sdc. It means we have to compose the final root from
+		 * root and src_root.
+		 */
+		src_root = mnt_fs_get_root(src_fs);
+
+		DBG(FS, ul_debugobj(fs, "source root: %s, source FS root: %s", root, src_root));
+
+		if (src_root && !startswith(root, src_root)) {
+			if (strcmp(root, "/") == 0) {
+				free(root);
+				root = strdup(src_root);
+				if (!root)
+					goto err;
+			} else {
+				char *tmp;
+				if (asprintf(&tmp, "%s%s", src_root, root) < 0)
+					goto err;
+				free(root);
+				root = tmp;
+			}
+		}
+	}
+
+#ifdef HAVE_BTRFS_SUPPORT
+	/*
+	 * btrfs-subvolume mount -- get subvolume name and use it as a root-fs path
+	 */
+	else if (tb && fs->fstype &&
+		 (!strcmp(fs->fstype, "btrfs") || !strcmp(fs->fstype, "auto"))) {
+		if (get_btrfs_fs_root(tb, fs, &root) < 0)
+			goto err;
+	}
+#endif /* HAVE_BTRFS_SUPPORT */
+
+dflt:
+	if (!root) {
+		root = strdup("/");
+		if (!root)
+			goto err;
+	}
+	*fsroot = root;
+
+	DBG(TAB, ul_debug("FS root result: %s", root));
+
+	return src_fs;
+err:
+	free(root);
+	return NULL;
+}
+
+
+int __mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs,
+			      const char *tgt_prefix)
+{
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+
+	char *root = NULL;
+	char *src2 = NULL;
+	const char *src = NULL, *tgt = NULL;
+	char *xtgt = NULL, *tgt_buf = NULL;
+	int rc = 0;
+	dev_t devno = 0;
+
+	DBG(FS, ul_debugobj(fstab_fs, "mnt_table_is_fs_mounted: target=%s, source=%s",
+				mnt_fs_get_target(fstab_fs),
+				mnt_fs_get_source(fstab_fs)));
+
+	if (mnt_fs_is_swaparea(fstab_fs) || mnt_table_is_empty(tb)) {
+		DBG(FS, ul_debugobj(fstab_fs, "- ignore (swap or no data)"));
+		return 0;
+	}
+
+	if (is_mountinfo(tb)) {
+		/* @tb is mountinfo, so we can try to use fs-roots */
+		struct libmnt_fs *rootfs;
+		int flags = 0;
+
+		if (mnt_fs_get_option(fstab_fs, "bind", NULL, NULL) == 0 ||
+		    mnt_fs_get_option(fstab_fs, "rbind", NULL, NULL) == 0)
+			flags = MS_BIND;
+
+		rootfs = mnt_table_get_fs_root(tb, fstab_fs, flags, &root);
+		if (rootfs) {
+			const char *fstype = mnt_fs_get_fstype(rootfs);
+
+			src = mnt_fs_get_srcpath(rootfs);
+			if (fstype && strncmp(fstype, "nfs", 3) == 0 && root) {
+				/* NFS stores the root at the end of the source */
+				src = src2 = strappend(src, root);
+				free(root);
+				root = NULL;
+			}
+		}
+	}
+
+	if (!src)
+		src = mnt_fs_get_source(fstab_fs);
+
+	if (src && tb->cache && !mnt_fs_is_pseudofs(fstab_fs))
+		src = mnt_resolve_spec(src, tb->cache);
+
+	if (src && root) {
+		struct stat st;
+
+		devno = mnt_fs_get_devno(fstab_fs);
+		if (!devno && stat(src, &st) == 0 && S_ISBLK(st.st_mode))
+			devno = st.st_rdev;
+	}
+
+	tgt = mnt_fs_get_target(fstab_fs);
+
+	if (!tgt || !src) {
+		DBG(FS, ul_debugobj(fstab_fs, "- ignore (no source/target)"));
+		goto done;
+	}
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	DBG(FS, ul_debugobj(fstab_fs, "mnt_table_is_fs_mounted: src=%s, tgt=%s, root=%s", src, tgt, root));
+
+	while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
+
+		int eq = mnt_fs_streq_srcpath(fs, src);
+
+		if (!eq && devno && mnt_fs_get_devno(fs) == devno)
+			eq = 1;
+
+		if (!eq) {
+			/* The source does not match. Maybe the source is a loop
+			 * device backing file.
+			 */
+			uint64_t offset = 0;
+			char *val;
+			size_t len;
+			int flags = 0;
+
+			if (!mnt_fs_get_srcpath(fs) ||
+			    !startswith(mnt_fs_get_srcpath(fs), "/dev/loop"))
+				continue;	/* does not look like loopdev */
+
+			if (mnt_fs_get_option(fstab_fs, "offset", &val, &len) == 0) {
+				if (mnt_parse_offset(val, len, &offset)) {
+					DBG(FS, ul_debugobj(fstab_fs, "failed to parse offset="));
+					continue;
+				}
+				flags = LOOPDEV_FL_OFFSET;
+			}
+
+			DBG(FS, ul_debugobj(fs, "checking for loop: src=%s", mnt_fs_get_srcpath(fs)));
+#if __linux__
+			if (!loopdev_is_used(mnt_fs_get_srcpath(fs), src, offset, 0, flags))
+				continue;
+
+			DBG(FS, ul_debugobj(fs, "used loop"));
+#endif
+		}
+
+		if (root) {
+			const char *fstype = mnt_fs_get_fstype(fs);
+
+			if (fstype && (strcmp(fstype, "cifs") == 0 ||
+				       strcmp(fstype, "smb3") == 0)) {
+
+				const char *sub = get_cifs_unc_subdir_path(src);
+				const char *r = mnt_fs_get_root(fs);
+
+				if (!sub || !r || (!streq_paths(sub, r) &&
+						   !streq_paths("/", r)))
+					continue;
+			} else {
+				const char *r = mnt_fs_get_root(fs);
+				if (!r || strcmp(r, root) != 0)
+					continue;
+			}
+		}
+
+		/*
+		 * Compare target, try to minimize the number of situations when we
+		 * need to canonicalize the path to avoid readlink() on
+		 * mountpoints.
+		 */
+		if (!xtgt) {
+			if (tgt_prefix) {
+				const char *p = *tgt == '/' ? tgt + 1 : tgt;
+				if (!*p)
+					tgt = tgt_prefix;	/* target is '/' */
+				else {
+					if (asprintf(&tgt_buf, "%s/%s", tgt_prefix, p) <= 0) {
+						rc = -ENOMEM;
+						goto done;
+					}
+					tgt = tgt_buf;
+				}
+			}
+
+			if (mnt_fs_streq_target(fs, tgt))
+				break;
+			if (tb->cache)
+				xtgt = mnt_resolve_path(tgt, tb->cache);
+		}
+		if (xtgt && mnt_fs_streq_target(fs, xtgt))
+			break;
+	}
+
+	if (fs)
+		rc = 1;		/* success */
+done:
+	free(root);
+	free(tgt_buf);
+
+	DBG(TAB, ul_debugobj(tb, "mnt_table_is_fs_mounted: %s [rc=%d]", src, rc));
+	free(src2);
+	return rc;
+}
+
+/**
+ * mnt_table_is_fs_mounted:
+ * @tb: /proc/self/mountinfo file
+ * @fstab_fs: /etc/fstab entry
+ *
+ * Checks if the @fstab_fs entry is already in the @tb table. The "swap" is
+ * ignored. This function explicitly compares the source, target and root of the
+ * filesystems.
+ *
+ * Note that source and target are canonicalized only if a cache for @tb is
+ * defined (see mnt_table_set_cache()). The target canonicalization may
+ * trigger automount on autofs mountpoints!
+ *
+ * Don't use it if you want to know if a device is mounted, just use
+ * mnt_table_find_source() on the device.
+ *
+ * This function is designed mostly for "mount -a".
+ *
+ * Returns: 0 or 1
+ */
+int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs)
+{
+	return __mnt_table_is_fs_mounted(tb, fstab_fs, NULL);
+}
+
+
+#ifdef TEST_PROGRAM
+#include "pathnames.h"
+
+static int parser_errcb(struct libmnt_table *tb, const char *filename, int line)
+{
+	fprintf(stderr, "%s:%d: parse error\n", filename, line);
+
+	return 1;	/* all errors are recoverable -- this is the default */
+}
+
+static struct libmnt_table *create_table(const char *file, int comments)
+{
+	struct libmnt_table *tb;
+
+	if (!file)
+		return NULL;
+	tb = mnt_new_table();
+	if (!tb)
+		goto err;
+
+	mnt_table_enable_comments(tb, comments);
+	mnt_table_set_parser_errcb(tb, parser_errcb);
+
+	if (mnt_table_parse_file(tb, file) != 0)
+		goto err;
+	return tb;
+err:
+	fprintf(stderr, "%s: parsing failed\n", file);
+	mnt_unref_table(tb);
+	return NULL;
+}
+
+static int test_copy_fs(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb;
+	struct libmnt_fs *fs;
+	int rc = -1;
+
+	tb = create_table(argv[1], FALSE);
+	if (!tb)
+		return -1;
+
+	fs = mnt_table_find_target(tb, "/", MNT_ITER_FORWARD);
+	if (!fs)
+		goto done;
+
+	printf("ORIGINAL:\n");
+	mnt_fs_print_debug(fs, stdout);
+
+	fs = mnt_copy_fs(NULL, fs);
+	if (!fs)
+		goto done;
+
+	printf("COPY:\n");
+	mnt_fs_print_debug(fs, stdout);
+	mnt_unref_fs(fs);
+	rc = 0;
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_parse(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb = NULL;
+	struct libmnt_iter *itr = NULL;
+	struct libmnt_fs *fs;
+	int rc = -1;
+	int parse_comments = FALSE;
+
+	if (argc == 3 && !strcmp(argv[2], "--comments"))
+		parse_comments = TRUE;
+
+	tb = create_table(argv[1], parse_comments);
+	if (!tb)
+		return -1;
+
+	itr = mnt_new_iter(MNT_ITER_FORWARD);
+	if (!itr)
+		goto done;
+
+	if (mnt_table_get_intro_comment(tb))
+		fprintf(stdout, "Initial comment:\n\"%s\"\n",
+				mnt_table_get_intro_comment(tb));
+
+	while(mnt_table_next_fs(tb, itr, &fs) == 0)
+		mnt_fs_print_debug(fs, stdout);
+
+	if (mnt_table_get_trailing_comment(tb))
+		fprintf(stdout, "Trailing comment:\n\"%s\"\n",
+				mnt_table_get_trailing_comment(tb));
+	rc = 0;
+done:
+	mnt_free_iter(itr);
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_find_idx(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb;
+	struct libmnt_fs *fs = NULL;
+	struct libmnt_cache *mpc = NULL;
+	const char *file, *what;
+	int rc = -1;
+
+	if (argc != 3) {
+		fprintf(stderr, "try --help\n");
+		return -EINVAL;
+	}
+
+	file = argv[1], what = argv[2];
+
+	tb = create_table(file, FALSE);
+	if (!tb)
+		goto done;
+
+	/* create a cache for canonicalized paths */
+	mpc = mnt_new_cache();
+	if (!mpc)
+		goto done;
+	mnt_table_set_cache(tb, mpc);
+	mnt_unref_cache(mpc);
+
+	fs = mnt_table_find_target(tb, what, MNT_ITER_BACKWARD);
+
+	if (!fs)
+		fprintf(stderr, "%s: not found '%s'\n", file, what);
+	else {
+		int idx = mnt_table_find_fs(tb, fs);
+
+		if (idx < 1)
+			fprintf(stderr, "%s: not found '%s' fs pointer", file, what);
+		else {
+			printf("%s index is %d\n", what, idx);
+			rc = 0;
+		}
+	}
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_find(struct libmnt_test *ts, int argc, char *argv[], int dr)
+{
+	struct libmnt_table *tb;
+	struct libmnt_fs *fs = NULL;
+	struct libmnt_cache *mpc = NULL;
+	const char *file, *find, *what;
+	int rc = -1;
+
+	if (argc != 4) {
+		fprintf(stderr, "try --help\n");
+		return -EINVAL;
+	}
+
+	file = argv[1], find = argv[2], what = argv[3];
+
+	tb = create_table(file, FALSE);
+	if (!tb)
+		goto done;
+
+	/* create a cache for canonicalized paths */
+	mpc = mnt_new_cache();
+	if (!mpc)
+		goto done;
+	mnt_table_set_cache(tb, mpc);
+	mnt_unref_cache(mpc);
+
+	if (strcasecmp(find, "source") == 0)
+		fs = mnt_table_find_source(tb, what, dr);
+	else if (strcasecmp(find, "target") == 0)
+		fs = mnt_table_find_target(tb, what, dr);
+
+	if (!fs)
+		fprintf(stderr, "%s: not found %s '%s'\n", file, find, what);
+	else {
+		mnt_fs_print_debug(fs, stdout);
+		rc = 0;
+	}
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_find_bw(struct libmnt_test *ts, int argc, char *argv[])
+{
+	return test_find(ts, argc, argv, MNT_ITER_BACKWARD);
+}
+
+static int test_find_fw(struct libmnt_test *ts, int argc, char *argv[])
+{
+	return test_find(ts, argc, argv, MNT_ITER_FORWARD);
+}
+
+static int test_find_pair(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb;
+	struct libmnt_fs *fs;
+	struct libmnt_cache *mpc = NULL;
+	int rc = -1;
+
+	tb = create_table(argv[1], FALSE);
+	if (!tb)
+		return -1;
+	mpc = mnt_new_cache();
+	if (!mpc)
+		goto done;
+	mnt_table_set_cache(tb, mpc);
+	mnt_unref_cache(mpc);
+
+	fs = mnt_table_find_pair(tb, argv[2], argv[3], MNT_ITER_FORWARD);
+	if (!fs)
+		goto done;
+
+	mnt_fs_print_debug(fs, stdout);
+	rc = 0;
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_find_mountpoint(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb;
+	struct libmnt_fs *fs;
+	struct libmnt_cache *mpc = NULL;
+	int rc = -1;
+
+	tb = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
+	if (!tb)
+		return -1;
+	mpc = mnt_new_cache();
+	if (!mpc)
+		goto done;
+	mnt_table_set_cache(tb, mpc);
+	mnt_unref_cache(mpc);
+
+	fs = mnt_table_find_mountpoint(tb, argv[1], MNT_ITER_BACKWARD);
+	if (!fs)
+		goto done;
+
+	mnt_fs_print_debug(fs, stdout);
+	rc = 0;
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int test_is_mounted(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb = NULL, *fstab = NULL;
+	struct libmnt_fs *fs;
+	struct libmnt_iter *itr = NULL;
+	struct libmnt_cache *mpc = NULL;
+	int writable = 0;
+	const char *path = NULL;
+
+	if (mnt_has_regular_mtab(&path, &writable) == 1 && writable == 0)
+		tb = mnt_new_table_from_file(path);
+	else
+		tb = mnt_new_table_from_file("/proc/self/mountinfo");
+
+	if (!tb) {
+		fprintf(stderr, "failed to parse mountinfo\n");
+		return -1;
+	}
+
+	fstab = create_table(argv[1], FALSE);
+	if (!fstab)
+		goto done;
+
+	itr = mnt_new_iter(MNT_ITER_FORWARD);
+	if (!itr)
+		goto done;
+
+	mpc = mnt_new_cache();
+	if (!mpc)
+		goto done;
+	mnt_table_set_cache(tb, mpc);
+	mnt_unref_cache(mpc);
+
+	while (mnt_table_next_fs(fstab, itr, &fs) == 0) {
+		if (mnt_table_is_fs_mounted(tb, fs))
+			printf("%s already mounted on %s\n",
+					mnt_fs_get_source(fs),
+					mnt_fs_get_target(fs));
+		else
+			printf("%s not mounted on %s\n",
+					mnt_fs_get_source(fs),
+					mnt_fs_get_target(fs));
+	}
+
+done:
+	mnt_unref_table(tb);
+	mnt_unref_table(fstab);
+	mnt_free_iter(itr);
+	return 0;
+}
+
+/* returns 0 if @a and @b targets are the same */
+static int test_uniq_cmp(struct libmnt_table *tb __attribute__((__unused__)),
+			 struct libmnt_fs *a,
+			 struct libmnt_fs *b)
+{
+	assert(a);
+	assert(b);
+
+	return mnt_fs_streq_target(a, mnt_fs_get_target(b)) ? 0 : 1;
+}
+
+static int test_uniq(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb;
+	int rc = -1;
+
+	if (argc != 2) {
+		fprintf(stderr, "try --help\n");
+		return -EINVAL;
+	}
+
+	tb = create_table(argv[1], FALSE);
+	if (!tb)
+		goto done;
+
+	if (mnt_table_uniq_fs(tb, 0, test_uniq_cmp) == 0) {
+		struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_FORWARD);
+		struct libmnt_fs *fs;
+		if (!itr)
+			goto done;
+		while (mnt_table_next_fs(tb, itr, &fs) == 0)
+			mnt_fs_print_debug(fs, stdout);
+		mnt_free_iter(itr);
+		rc = 0;
+	}
+done:
+	mnt_unref_table(tb);
+	return rc;
+}
+
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+	{ "--parse",    test_parse,        "<file> [--comments] parse and print tab" },
+	{ "--find-forward",  test_find_fw, "<file> <source|target> <string>" },
+	{ "--find-backward", test_find_bw, "<file> <source|target> <string>" },
+	{ "--uniq-target",   test_uniq,    "<file>" },
+	{ "--find-pair",     test_find_pair, "<file> <source> <target>" },
+	{ "--find-fs",       test_find_idx, "<file> <target>" },
+	{ "--find-mountpoint", test_find_mountpoint, "<path>" },
+	{ "--copy-fs",       test_copy_fs, "<file>  copy root FS from the file" },
+	{ "--is-mounted",    test_is_mounted, "<fstab> check what from fstab is already mounted" },
+	{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/tab_diff.c b/libmount/src/tab_diff.c
new file mode 100644
index 0000000..81694bc
--- /dev/null
+++ b/libmount/src/tab_diff.c
@@ -0,0 +1,377 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2011-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: tabdiff
+ * @title: Compare changes in mount tables
+ * @short_description: compare changes in the list of the mounted filesystems
+ */
+#include "mountP.h"
+
+struct tabdiff_entry {
+	int	oper;			/* MNT_TABDIFF_* flags; */
+
+	struct libmnt_fs *old_fs;	/* pointer to the old FS */
+	struct libmnt_fs *new_fs;	/* pointer to the new FS */
+
+	struct list_head changes;
+};
+
+struct libmnt_tabdiff {
+	int nchanges;			/* number of changes */
+
+	struct list_head changes;	/* list with modified entries */
+	struct list_head unused;	/* list with unused entries */
+};
+
+/**
+ * mnt_new_tabdiff:
+ *
+ * Allocates a new table diff struct.
+ *
+ * Returns: new diff handler or NULL.
+ */
+struct libmnt_tabdiff *mnt_new_tabdiff(void)
+{
+	struct libmnt_tabdiff *df = calloc(1, sizeof(*df));
+
+	if (!df)
+		return NULL;
+
+	DBG(DIFF, ul_debugobj(df, "alloc"));
+
+	INIT_LIST_HEAD(&df->changes);
+	INIT_LIST_HEAD(&df->unused);
+	return df;
+}
+
+static void free_tabdiff_entry(struct tabdiff_entry *de)
+{
+	if (!de)
+		return;
+	list_del(&de->changes);
+	mnt_unref_fs(de->new_fs);
+	mnt_unref_fs(de->old_fs);
+	free(de);
+}
+
+/**
+ * mnt_free_tabdiff:
+ * @df: tab diff
+ *
+ * Deallocates tab diff struct and all entries.
+ */
+void mnt_free_tabdiff(struct libmnt_tabdiff *df)
+{
+	if (!df)
+		return;
+
+	DBG(DIFF, ul_debugobj(df, "free"));
+
+	while (!list_empty(&df->changes)) {
+		struct tabdiff_entry *de = list_entry(df->changes.next,
+			                  struct tabdiff_entry, changes);
+		free_tabdiff_entry(de);
+	}
+
+	free(df);
+}
+
+/**
+ * mnt_tabdiff_next_change:
+ * @df: tabdiff pointer
+ * @itr: iterator
+ * @old_fs: returns the old entry or NULL if new entry added
+ * @new_fs: returns the new entry or NULL if old entry removed
+ * @oper: MNT_TABDIFF_{MOVE,UMOUNT,REMOUNT,MOUNT} flags
+ *
+ * The options @old_fs, @new_fs and @oper are optional.
+ *
+ * Returns: 0 on success, negative number in case of error or 1 at the end of list.
+ */
+int mnt_tabdiff_next_change(struct libmnt_tabdiff *df, struct libmnt_iter *itr,
+		struct libmnt_fs **old_fs, struct libmnt_fs **new_fs, int *oper)
+{
+	int rc = 1;
+	struct tabdiff_entry *de = NULL;
+
+	if (!df || !itr)
+		return -EINVAL;
+
+	if (!itr->head)
+		MNT_ITER_INIT(itr, &df->changes);
+	if (itr->p != itr->head) {
+		MNT_ITER_ITERATE(itr, de, struct tabdiff_entry, changes);
+		rc = 0;
+	}
+
+	if (old_fs)
+		*old_fs = de ? de->old_fs : NULL;
+	if (new_fs)
+		*new_fs = de ? de->new_fs : NULL;
+	if (oper)
+		*oper = de ? de->oper : 0;
+
+	return rc;
+}
+
+static int tabdiff_reset(struct libmnt_tabdiff *df)
+{
+	assert(df);
+
+	DBG(DIFF, ul_debugobj(df, "resetting"));
+
+	/* zeroize all entries and move them to the list of unused
+	 */
+	while (!list_empty(&df->changes)) {
+		struct tabdiff_entry *de = list_entry(df->changes.next,
+			                  struct tabdiff_entry, changes);
+
+		list_del_init(&de->changes);
+		list_add_tail(&de->changes, &df->unused);
+
+		mnt_unref_fs(de->new_fs);
+		mnt_unref_fs(de->old_fs);
+
+		de->new_fs = de->old_fs = NULL;
+		de->oper = 0;
+	}
+
+	df->nchanges = 0;
+	return 0;
+}
+
+static int tabdiff_add_entry(struct libmnt_tabdiff *df, struct libmnt_fs *old,
+			     struct libmnt_fs *new, int oper)
+{
+	struct tabdiff_entry *de;
+
+	assert(df);
+
+	DBG(DIFF, ul_debugobj(df, "add change on %s",
+				mnt_fs_get_target(new ? new : old)));
+
+	if (!list_empty(&df->unused)) {
+		de = list_entry(df->unused.next, struct tabdiff_entry, changes);
+		list_del(&de->changes);
+	} else {
+		de = calloc(1, sizeof(*de));
+		if (!de)
+			return -ENOMEM;
+	}
+
+	INIT_LIST_HEAD(&de->changes);
+
+	mnt_ref_fs(new);
+	mnt_ref_fs(old);
+
+	mnt_unref_fs(de->new_fs);
+	mnt_unref_fs(de->old_fs);
+
+	de->old_fs = old;
+	de->new_fs = new;
+	de->oper = oper;
+
+	list_add_tail(&de->changes, &df->changes);
+	df->nchanges++;
+	return 0;
+}
+
+static struct tabdiff_entry *tabdiff_get_mount(struct libmnt_tabdiff *df,
+					       const char *src,
+					       int id)
+{
+	struct list_head *p;
+
+	assert(df);
+
+	list_for_each(p, &df->changes) {
+		struct tabdiff_entry *de;
+
+		de = list_entry(p, struct tabdiff_entry, changes);
+
+		if (de->oper == MNT_TABDIFF_MOUNT && de->new_fs &&
+		    mnt_fs_get_id(de->new_fs) == id) {
+
+			const char *s = mnt_fs_get_source(de->new_fs);
+
+			if (s == NULL && src == NULL)
+				return de;
+			if (s && src && strcmp(s, src) == 0)
+				return de;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * mnt_diff_tables:
+ * @df: diff handler
+ * @old_tab: old table
+ * @new_tab: new table
+ *
+ * Compares @old_tab and @new_tab, the result is stored in @df and accessible by
+ * mnt_tabdiff_next_change().
+ *
+ * Returns: number of changes, negative number in case of error.
+ */
+int mnt_diff_tables(struct libmnt_tabdiff *df, struct libmnt_table *old_tab,
+		    struct libmnt_table *new_tab)
+{
+	struct libmnt_fs *fs;
+	struct libmnt_iter itr;
+	int no, nn;
+
+	if (!df || !old_tab || !new_tab)
+		return -EINVAL;
+
+	tabdiff_reset(df);
+
+	no = mnt_table_get_nents(old_tab);
+	nn = mnt_table_get_nents(new_tab);
+
+	if (!no && !nn)			/* both tables are empty */
+		return 0;
+
+	DBG(DIFF, ul_debugobj(df, "analyze new (%d entries), "
+				          "old (%d entries)",
+				nn, no));
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	/* all mounted or umounted */
+	if (!no && nn) {
+		while(mnt_table_next_fs(new_tab, &itr, &fs) == 0)
+			tabdiff_add_entry(df, NULL, fs, MNT_TABDIFF_MOUNT);
+		goto done;
+
+	} else if (no && !nn) {
+		while(mnt_table_next_fs(old_tab, &itr, &fs) == 0)
+			tabdiff_add_entry(df, fs, NULL, MNT_TABDIFF_UMOUNT);
+		goto done;
+	}
+
+	/* search newly mounted or modified */
+	while(mnt_table_next_fs(new_tab, &itr, &fs) == 0) {
+		struct libmnt_fs *o_fs;
+		const char *src = mnt_fs_get_source(fs),
+			   *tgt = mnt_fs_get_target(fs);
+
+		o_fs = mnt_table_find_pair(old_tab, src, tgt, MNT_ITER_FORWARD);
+		if (!o_fs)
+			/* 'fs' is not in the old table -- so newly mounted */
+			tabdiff_add_entry(df, NULL, fs, MNT_TABDIFF_MOUNT);
+		else {
+			/* is modified? */
+			const char *v1 = mnt_fs_get_vfs_options(o_fs),
+				   *v2 = mnt_fs_get_vfs_options(fs),
+				   *f1 = mnt_fs_get_fs_options(o_fs),
+				   *f2 = mnt_fs_get_fs_options(fs);
+
+			if ((v1 && v2 && strcmp(v1, v2) != 0) || (f1 && f2 && strcmp(f1, f2) != 0))
+				tabdiff_add_entry(df, o_fs, fs, MNT_TABDIFF_REMOUNT);
+		}
+	}
+
+	/* search umounted or moved */
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while(mnt_table_next_fs(old_tab, &itr, &fs) == 0) {
+		const char *src = mnt_fs_get_source(fs),
+			   *tgt = mnt_fs_get_target(fs);
+
+		if (!mnt_table_find_pair(new_tab, src, tgt, MNT_ITER_FORWARD)) {
+			struct tabdiff_entry *de;
+
+			de = tabdiff_get_mount(df, src,	mnt_fs_get_id(fs));
+			if (de) {
+				mnt_ref_fs(fs);
+				mnt_unref_fs(de->old_fs);
+				de->oper = MNT_TABDIFF_MOVE;
+				de->old_fs = fs;
+			} else
+				tabdiff_add_entry(df, fs, NULL, MNT_TABDIFF_UMOUNT);
+		}
+	}
+done:
+	DBG(DIFF, ul_debugobj(df, "%d changes detected", df->nchanges));
+	return df->nchanges;
+}
+
+#ifdef TEST_PROGRAM
+
+static int test_diff(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_table *tb_old, *tb_new;
+	struct libmnt_tabdiff *diff;
+	struct libmnt_iter *itr;
+	struct libmnt_fs *old, *new;
+	int rc = -1, change;
+
+	tb_old = mnt_new_table_from_file(argv[1]);
+	tb_new = mnt_new_table_from_file(argv[2]);
+	diff = mnt_new_tabdiff();
+	itr = mnt_new_iter(MNT_ITER_FORWARD);
+
+	if (!tb_old || !tb_new || !diff || !itr) {
+		warnx("failed to allocate resources");
+		goto done;
+	}
+
+	rc = mnt_diff_tables(diff, tb_old, tb_new);
+	if (rc < 0)
+		goto done;
+
+	while(mnt_tabdiff_next_change(diff, itr, &old, &new, &change) == 0) {
+
+		printf("%s on %s: ", mnt_fs_get_source(new ? new : old),
+				     mnt_fs_get_target(new ? new : old));
+
+		switch(change) {
+		case MNT_TABDIFF_MOVE:
+			printf("MOVED to %s\n", mnt_fs_get_target(new));
+			break;
+		case MNT_TABDIFF_UMOUNT:
+			printf("UMOUNTED\n");
+			break;
+		case MNT_TABDIFF_REMOUNT:
+			printf("REMOUNTED from '%s' to '%s'\n",
+					mnt_fs_get_options(old),
+					mnt_fs_get_options(new));
+			break;
+		case MNT_TABDIFF_MOUNT:
+			printf("MOUNTED\n");
+			break;
+		default:
+			printf("unknown change!\n");
+		}
+	}
+
+	rc = 0;
+done:
+	mnt_unref_table(tb_old);
+	mnt_unref_table(tb_new);
+	mnt_free_tabdiff(diff);
+	mnt_free_iter(itr);
+	return rc;
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+		{ "--diff", test_diff, "<old> <new> prints change" },
+		{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/tab_parse.c b/libmount/src/tab_parse.c
new file mode 100644
index 0000000..fa2d31b
--- /dev/null
+++ b/libmount/src/tab_parse.c
@@ -0,0 +1,1343 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+#ifdef HAVE_SCANDIRAT
+#ifndef __USE_GNU
+#define __USE_GNU
+#endif	/* !__USE_GNU */
+#endif	/* HAVE_SCANDIRAT */
+
+#include <ctype.h>
+#include <limits.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+#include "fileutils.h"
+#include "mangle.h"
+#include "mountP.h"
+#include "pathnames.h"
+#include "strutils.h"
+
+struct libmnt_parser {
+	FILE	*f;		/* fstab, mtab, swaps or mountinfo ... */
+	const char *filename;	/* file name or NULL */
+	char	*buf;		/* buffer (the current line content) */
+	size_t	bufsiz;		/* size of the buffer */
+	size_t	line;		/* current line */
+};
+
+static void parser_cleanup(struct libmnt_parser *pa)
+{
+	if (!pa)
+		return;
+	free(pa->buf);
+	memset(pa, 0, sizeof(*pa));
+}
+
+static const char *next_s32(const char *s, int *num, int *rc)
+{
+	char *end = NULL;
+
+	if (!s || !*s)
+		return s;
+
+	*rc = -EINVAL;
+	*num = strtol(s, &end, 10);
+	if (end == NULL || s == end)
+	       return s;
+	if (*end == ' ' || *end == '\t' || *end == '\0')
+		*rc = 0;
+	return end;
+}
+
+static const char *next_u64(const char *s, uint64_t *num, int *rc)
+{
+	char *end = NULL;
+
+	if (!s || !*s)
+		return s;
+
+	*rc = -EINVAL;
+	*num = (uint64_t) strtoumax(s, &end, 10);
+	if (end == NULL || s == end)
+	       return s;
+	if (*end == ' ' || *end == '\t' || *end == '\0')
+		*rc = 0;
+	return end;
+}
+
+static inline const char *skip_separator(const char *p)
+{
+	while (p && (*p == ' ' || *p == '\t'))
+		++p;
+	return p;
+}
+
+static inline const char *skip_nonspearator(const char *p)
+{
+	while (p && *p && !(*p == ' ' || *p == '\t'))
+		p++;
+	return p;
+}
+
+/*
+ * Parses one line from {fs,m}tab
+ */
+static int mnt_parse_table_line(struct libmnt_fs *fs, const char *s)
+{
+	int rc = 0;
+	char *p = NULL;
+
+	fs->passno = fs->freq = 0;
+
+	/* (1) source */
+	p = unmangle(s, &s);
+	if (!p || (rc = __mnt_fs_set_source_ptr(fs, p))) {
+		DBG(TAB, ul_debug("tab parse error: [source]"));
+		free(p);
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (2) target */
+	fs->target = unmangle(s, &s);
+	if (!fs->target) {
+		DBG(TAB, ul_debug("tab parse error: [target]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (3) FS type */
+	p = unmangle(s, &s);
+	if (!p || (rc = __mnt_fs_set_fstype_ptr(fs, p))) {
+		DBG(TAB, ul_debug("tab parse error: [fstype]"));
+		free(p);
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (4) options (optional) */
+	p = unmangle(s, &s);
+	if (p && (rc = mnt_fs_set_options(fs, p))) {
+		DBG(TAB, ul_debug("tab parse error: [options]"));
+		free(p);
+		goto fail;
+	}
+	if (!p)
+		goto done;
+	free(p);
+
+	s = skip_separator(s);
+	if (!s || !*s)
+		goto done;
+
+	/* (5) freq (optional) */
+	s = next_s32(s, &fs->freq, &rc);
+	if (s && *s && rc) {
+		DBG(TAB, ul_debug("tab parse error: [freq]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+	if (!s || !*s)
+		goto done;
+
+	/* (6) passno (optional) */
+	s = next_s32(s, &fs->passno, &rc);
+	if (s && *s && rc) {
+		DBG(TAB, ul_debug("tab parse error: [passno]"));
+		goto fail;
+	}
+
+done:
+	return 0;
+fail:
+	if (rc == 0)
+		rc = -EINVAL;
+	DBG(TAB, ul_debug("tab parse error on: '%s' [rc=%d]", s, rc));
+	return rc;
+}
+
+
+/*
+ * Parses one line from a mountinfo file
+ */
+static int mnt_parse_mountinfo_line(struct libmnt_fs *fs, const char *s)
+{
+	int rc = 0;
+	unsigned int maj, min;
+	char *p;
+
+	fs->flags |= MNT_FS_KERNEL;
+
+	/* (1) id */
+	s = next_s32(s, &fs->id, &rc);
+	if (!s || !*s || rc) {
+		DBG(TAB, ul_debug("tab parse error: [id]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (2) parent */
+	s = next_s32(s, &fs->parent, &rc);
+	if (!s || !*s || rc) {
+		DBG(TAB, ul_debug("tab parse error: [parent]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (3) maj:min */
+	if (sscanf(s, "%u:%u", &maj, &min) != 2) {
+		DBG(TAB, ul_debug("tab parse error: [maj:min]"));
+		goto fail;
+	}
+	fs->devno = makedev(maj, min);
+	s = skip_nonspearator(s);
+	s = skip_separator(s);
+
+	/* (4) mountroot */
+	fs->root = unmangle(s, &s);
+	if (!fs->root) {
+		DBG(TAB, ul_debug("tab parse error: [mountroot]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (5) target */
+	fs->target = unmangle(s, &s);
+	if (!fs->target) {
+		DBG(TAB, ul_debug("tab parse error: [target]"));
+		goto fail;
+	}
+
+	/* remove "\040(deleted)" suffix */
+	p = (char *) endswith(fs->target, PATH_DELETED_SUFFIX);
+	if (p && *p)
+		*p = '\0';
+
+	s = skip_separator(s);
+
+	/* (6) vfs options (fs-independent) */
+	fs->vfs_optstr = unmangle(s, &s);
+	if (!fs->vfs_optstr) {
+		DBG(TAB, ul_debug("tab parse error: [VFS options]"));
+		goto fail;
+	}
+
+	/* (7) optional fields, terminated by " - " */
+	p = strstr(s, " - ");
+	if (!p) {
+		DBG(TAB, ul_debug("mountinfo parse error: separator not found"));
+		return -EINVAL;
+	}
+	if (p > s + 1)
+		fs->opt_fields = strndup(s + 1, p - s - 1);
+
+	s = skip_separator(p + 3);
+
+	/* (8) FS type */
+	p = unmangle(s, &s);
+	if (!p || (rc = __mnt_fs_set_fstype_ptr(fs, p))) {
+		DBG(TAB, ul_debug("tab parse error: [fstype]"));
+		free(p);
+		goto fail;
+	}
+
+	/* (9) source -- maybe empty string */
+	if (!s || !*s) {
+		DBG(TAB, ul_debug("tab parse error: [source]"));
+		goto fail;
+	} else if (*s == ' ' && *(s+1) == ' ') {
+		if ((rc = mnt_fs_set_source(fs, ""))) {
+			DBG(TAB, ul_debug("tab parse error: [empty source]"));
+			goto fail;
+		}
+	} else {
+		s = skip_separator(s);
+		p = unmangle(s, &s);
+		if (!p || (rc = __mnt_fs_set_source_ptr(fs, p))) {
+			DBG(TAB, ul_debug("tab parse error: [regular source]"));
+			free(p);
+			goto fail;
+		}
+	}
+
+	s = skip_separator(s);
+
+	/* (10) fs options (fs specific) */
+	fs->fs_optstr = unmangle(s, &s);
+	if (!fs->fs_optstr) {
+		DBG(TAB, ul_debug("tab parse error: [FS options]"));
+		goto fail;
+	}
+
+	/* merge VFS and FS options to one string */
+	fs->optstr = mnt_fs_strdup_options(fs);
+	if (!fs->optstr) {
+		rc = -ENOMEM;
+		DBG(TAB, ul_debug("tab parse error: [merge VFS and FS options]"));
+		goto fail;
+	}
+
+	return 0;
+fail:
+	if (rc == 0)
+		rc = -EINVAL;
+	DBG(TAB, ul_debug("tab parse error on: '%s' [rc=%d]", s, rc));
+	return rc;
+}
+
+/*
+ * Parses one line from utab file
+ */
+static int mnt_parse_utab_line(struct libmnt_fs *fs, const char *s)
+{
+	const char *p = s;
+
+	assert(fs);
+	assert(s);
+	assert(!fs->source);
+	assert(!fs->target);
+
+	while (p && *p) {
+		const char *end = NULL;
+
+		while (*p == ' ') p++;
+		if (!*p)
+			break;
+
+		if (!fs->source && !strncmp(p, "SRC=", 4)) {
+			char *v = unmangle(p + 4, &end);
+			if (!v)
+				goto enomem;
+			if (__mnt_fs_set_source_ptr(fs, v))
+				free(v);
+
+		} else if (!fs->target && !strncmp(p, "TARGET=", 7)) {
+			fs->target = unmangle(p + 7, &end);
+			if (!fs->target)
+				goto enomem;
+
+		} else if (!fs->root && !strncmp(p, "ROOT=", 5)) {
+			fs->root = unmangle(p + 5, &end);
+			if (!fs->root)
+				goto enomem;
+
+		} else if (!fs->bindsrc && !strncmp(p, "BINDSRC=", 8)) {
+			fs->bindsrc = unmangle(p + 8, &end);
+			if (!fs->bindsrc)
+				goto enomem;
+
+		} else if (!fs->user_optstr && !strncmp(p, "OPTS=", 5)) {
+			fs->user_optstr = unmangle(p + 5, &end);
+			if (!fs->user_optstr)
+				goto enomem;
+
+		} else if (!fs->attrs && !strncmp(p, "ATTRS=", 6)) {
+			fs->attrs = unmangle(p + 6, &end);
+			if (!fs->attrs)
+				goto enomem;
+
+		} else {
+			/* unknown variable */
+			while (*p && *p != ' ') p++;
+		}
+		if (end)
+			p = end;
+	}
+
+	return 0;
+enomem:
+	DBG(TAB, ul_debug("utab parse error: ENOMEM"));
+	return -ENOMEM;
+}
+
+/*
+ * Parses one line from /proc/swaps
+ */
+static int mnt_parse_swaps_line(struct libmnt_fs *fs, const char *s)
+{
+	uint64_t num;
+	int rc = 0;
+	char *p;
+
+	/* (1) source */
+	p = unmangle(s, &s);
+	if (p) {
+		char *x = (char *) endswith(p, PATH_DELETED_SUFFIX);
+		if (x && *x)
+			*x = '\0';
+	}
+	if (!p || (rc = __mnt_fs_set_source_ptr(fs, p))) {
+		DBG(TAB, ul_debug("tab parse error: [source]"));
+		free(p);
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (2) type */
+	fs->swaptype = unmangle(s, &s);
+	if (!fs->swaptype) {
+		DBG(TAB, ul_debug("tab parse error: [swaptype]"));
+		goto fail;
+	}
+
+	s = skip_separator(s);
+
+	/* (3) size */
+	s = next_u64(s, &num, &rc);
+	if (!s || !*s || rc) {
+		DBG(TAB, ul_debug("tab parse error: [size]"));
+		goto fail;
+	}
+	fs->size = num;
+
+	s = skip_separator(s);
+
+	/* (4) size */
+	s = next_u64(s, &num, &rc);
+	if (!s || !*s || rc) {
+		DBG(TAB, ul_debug("tab parse error: [used size]"));
+		goto fail;
+	}
+	fs->usedsize = num;
+
+	s = skip_separator(s);
+
+	/* (5) priority */
+	s = next_s32(s, &fs->priority, &rc);
+	if (rc) {
+		DBG(TAB, ul_debug("tab parse error: [priority]"));
+		goto fail;
+	}
+
+	mnt_fs_set_fstype(fs, "swap");
+	return 0;
+fail:
+	if (rc == 0)
+		rc = -EINVAL;
+	DBG(TAB, ul_debug("tab parse error on: '%s' [rc=%d]", s, rc));
+	return rc;
+}
+
+
+/*
+ * Returns {m,fs}tab or mountinfo file format (MNT_FMT_*)
+ *
+ * Note that we aren't trying to guess the utab file format, because this file
+ * always has to be parsed by private libmount routines with an explicitly defined
+ * format.
+ *
+ * mountinfo: "<number> <number> ... "
+ */
+static int guess_table_format(const char *line)
+{
+	unsigned int a, b;
+
+	DBG(TAB, ul_debug("trying to guess table type"));
+
+	if (sscanf(line, "%u %u", &a, &b) == 2)
+		return MNT_FMT_MOUNTINFO;
+
+	if (strncmp(line, "Filename\t", 9) == 0)
+		return MNT_FMT_SWAPS;
+
+	return MNT_FMT_FSTAB;		/* fstab, mtab or /proc/mounts */
+}
+
+static int is_comment_line(const char *line)
+{
+	const char *p = skip_blank(line);
+
+	if (p && (*p == '#' || *p == '\n'))
+		return 1;
+	return 0;
+}
+
+/* returns 1 if the last line in the @str is blank */
+static int is_terminated_by_blank(const char *str)
+{
+	size_t sz = str ? strlen(str) : 0;
+	const char *p = sz ? str + (sz - 1) : NULL;
+
+	if (!sz || !p || *p != '\n')
+		return 0;		/* empty or not terminated by '\n' */
+	if (p == str)
+		return 1;		/* only '\n' */
+	p--;
+	while (p >= str && (*p == ' ' || *p == '\t'))
+		p--;
+	return *p == '\n' ? 1 : 0;
+}
+
+/*
+ * Reads the next line from the file.
+ *
+ * Returns 0 if the line is a comment
+ *         1 if the line is not a comment
+ *        <0 on error
+ */
+static int next_comment_line(struct libmnt_parser *pa, char **last)
+{
+	if (getline(&pa->buf, &pa->bufsiz, pa->f) < 0)
+		return feof(pa->f) ? 1 : -errno;
+
+	pa->line++;
+	*last = strchr(pa->buf, '\n');
+
+	return is_comment_line(pa->buf) ? 0 : 1;
+}
+
+static int append_comment(struct libmnt_table *tb,
+			  struct libmnt_fs *fs,
+			  const char *comm,
+			  int eof)
+{
+	int rc, intro = mnt_table_get_nents(tb) == 0;
+
+	if (intro && is_terminated_by_blank(mnt_table_get_intro_comment(tb)))
+		intro = 0;
+
+	DBG(TAB, ul_debugobj(tb, "appending %s comment",
+			intro ? "intro" :
+			eof ? "trailing" : "fs"));
+	if (intro)
+		rc = mnt_table_append_intro_comment(tb, comm);
+	else if (eof) {
+		rc = mnt_table_set_trailing_comment(tb,
+				mnt_fs_get_comment(fs));
+		if (!rc)
+			rc = mnt_table_append_trailing_comment(tb, comm);
+		if (!rc)
+			rc = mnt_fs_set_comment(fs, NULL);
+	} else
+		rc = mnt_fs_append_comment(fs, comm);
+	return rc;
+}
+
+/*
+ * Read and parse the next line from {fs,m}tab or mountinfo
+ */
+static int mnt_table_parse_next(struct libmnt_parser *pa,
+				struct libmnt_table *tb,
+				struct libmnt_fs *fs)
+{
+	char *s;
+	int rc;
+
+	assert(tb);
+	assert(pa);
+	assert(fs);
+
+	/* read the next non-blank non-comment line */
+next_line:
+	do {
+		if (getline(&pa->buf, &pa->bufsiz, pa->f) < 0)
+			return -EINVAL;
+		pa->line++;
+		s = strchr(pa->buf, '\n');
+		if (!s) {
+			/* Missing final newline?  Otherwise an extremely */
+			/* long line - assume file was corrupted */
+			if (feof(pa->f)) {
+				DBG(TAB, ul_debugobj(tb,
+					"%s: no final newline",	pa->filename));
+				s = strchr(pa->buf, '\0');
+			} else {
+				DBG(TAB, ul_debugobj(tb,
+					"%s:%zu: missing newline at line",
+					pa->filename, pa->line));
+				goto err;
+			}
+		}
+
+		/* comments parser */
+		if (tb->comms
+		    && (tb->fmt == MNT_FMT_GUESS || tb->fmt == MNT_FMT_FSTAB)
+		    && is_comment_line(pa->buf)) {
+			do {
+				rc = append_comment(tb, fs, pa->buf, feof(pa->f));
+				if (!rc)
+					rc = next_comment_line(pa, &s);
+			} while (rc == 0);
+
+			if (rc == 1 && feof(pa->f))
+				rc = append_comment(tb, fs, NULL, 1);
+			if (rc < 0)
+				return rc;
+
+		}
+
+		*s = '\0';
+		if (--s >= pa->buf && *s == '\r')
+			*s = '\0';
+		s = (char *) skip_blank(pa->buf);
+	} while (*s == '\0' || *s == '#');
+
+	if (tb->fmt == MNT_FMT_GUESS) {
+		tb->fmt = guess_table_format(s);
+		if (tb->fmt == MNT_FMT_SWAPS)
+			goto next_line;			/* skip swap header */
+	}
+
+	switch (tb->fmt) {
+	case MNT_FMT_FSTAB:
+		rc = mnt_parse_table_line(fs, s);
+		break;
+	case MNT_FMT_MOUNTINFO:
+		rc = mnt_parse_mountinfo_line(fs, s);
+		break;
+	case MNT_FMT_UTAB:
+		rc = mnt_parse_utab_line(fs, s);
+		break;
+	case MNT_FMT_SWAPS:
+		if (strncmp(s, "Filename\t", 9) == 0)
+			goto next_line;			/* skip swap header */
+		rc = mnt_parse_swaps_line(fs, s);
+		break;
+	default:
+		rc = -1;	/* unknown format */
+		break;
+	}
+
+	if (rc == 0)
+		return 0;
+err:
+	DBG(TAB, ul_debugobj(tb, "%s:%zu: %s parse error", pa->filename, pa->line,
+				tb->fmt == MNT_FMT_MOUNTINFO ? "mountinfo" :
+				tb->fmt == MNT_FMT_SWAPS ? "swaps" :
+				tb->fmt == MNT_FMT_FSTAB ? "tab" : "utab"));
+
+	/* by default all errors are recoverable, otherwise behavior depends on
+	 * the errcb() function. See mnt_table_set_parser_errcb().
+	 */
+	return tb->errcb ? tb->errcb(tb, pa->filename, pa->line) : 1;
+}
+
+static pid_t path_to_tid(const char *filename)
+{
+	char *path = mnt_resolve_path(filename, NULL);
+	char *p, *end = NULL;
+	pid_t tid = 0;
+
+	if (!path)
+		goto done;
+	p = strrchr(path, '/');
+	if (!p)
+		goto done;
+	*p = '\0';
+	p = strrchr(path, '/');
+	if (!p)
+		goto done;
+	p++;
+
+	errno = 0;
+	tid = strtol(p, &end, 10);
+	if (errno || p == end || (end && *end)) {
+		tid = 0;
+		goto done;
+	}
+	DBG(TAB, ul_debug("TID for %s is %d", filename, tid));
+done:
+	free(path);
+	return tid;
+}
+
+static int kernel_fs_postparse(struct libmnt_table *tb,
+			       struct libmnt_fs *fs, pid_t *tid,
+			       const char *filename)
+{
+	int rc = 0;
+	const char *src = mnt_fs_get_srcpath(fs);
+
+	/* This is a filesystem description from /proc, so we're in some process
+	 * namespace. Let's remember the process PID.
+	 */
+	if (filename && *tid == -1)
+		*tid = path_to_tid(filename);
+
+	fs->tid = *tid;
+
+	/*
+	 * Convert obscure /dev/root to something more usable
+	 */
+	if (src && strcmp(src, "/dev/root") == 0) {
+		char *real = NULL;
+
+		rc = mnt_guess_system_root(fs->devno, tb->cache, &real);
+		if (rc < 0)
+			return rc;
+
+		if (rc == 0 && real) {
+			DBG(TAB, ul_debugobj(tb, "canonical root FS: %s", real));
+			rc = __mnt_fs_set_source_ptr(fs, real);
+
+		} else if (rc == 1) {
+			/* mnt_guess_system_root() returns 1 if not able to convert to
+			 * the real devname; ignore this problem */
+			rc = 0;
+		}
+	}
+
+	return rc;
+}
+
+static int __table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
+{
+	int rc = -1;
+	int flags = 0;
+	pid_t tid = -1;
+	struct libmnt_parser pa = { .line = 0 };
+
+	assert(tb);
+	assert(f);
+	assert(filename);
+
+	DBG(TAB, ul_debugobj(tb, "%s: start parsing [entries=%d, filter=%s]",
+				filename, mnt_table_get_nents(tb),
+				tb->fltrcb ? "yes" : "not"));
+
+	pa.filename = filename;
+	pa.f = f;
+
+	/* necessary for /proc/mounts only, the /proc/self/mountinfo
+	 * parser sets the flag properly
+	 */
+	if (filename && strcmp(filename, _PATH_PROC_MOUNTS) == 0)
+		flags = MNT_FS_KERNEL;
+
+	do {
+		struct libmnt_fs *fs;
+
+		if (feof(f)) {
+			DBG(TAB, ul_debugobj(tb, "end-of-file"));
+			break;
+		}
+		fs = mnt_new_fs();
+		if (!fs)
+			goto err;
+
+		/* parse */
+		rc = mnt_table_parse_next(&pa, tb, fs);
+
+		if (rc == 0 && tb->fltrcb && tb->fltrcb(fs, tb->fltrcb_data))
+			rc = 1;	/* filtered out by callback... */
+
+		/* add to the table */
+		if (rc == 0) {
+			rc = mnt_table_add_fs(tb, fs);
+			fs->flags |= flags;
+
+			if (rc == 0 && tb->fmt == MNT_FMT_MOUNTINFO) {
+				rc = kernel_fs_postparse(tb, fs, &tid, filename);
+				if (rc)
+					mnt_table_remove_fs(tb, fs);
+			}
+		}
+
+		/* remove reference (or deallocate on error) */
+		mnt_unref_fs(fs);
+
+		/* recoverable error */
+		if (rc > 0) {
+			DBG(TAB, ul_debugobj(tb, "recoverable error (continue)"));
+			continue;
+		}
+
+		/* fatal errors */
+		if (rc < 0 && !feof(f)) {
+			DBG(TAB, ul_debugobj(tb, "fatal error"));
+			goto err;
+		}
+	} while (1);
+
+	DBG(TAB, ul_debugobj(tb, "%s: stop parsing (%d entries)",
+				filename, mnt_table_get_nents(tb)));
+	parser_cleanup(&pa);
+	return 0;
+err:
+	DBG(TAB, ul_debugobj(tb, "%s: parse error (rc=%d)", filename, rc));
+	parser_cleanup(&pa);
+	return rc;
+}
+
+/**
+ * mnt_table_parse_stream:
+ * @tb: tab pointer
+ * @f: file stream
+ * @filename: filename used for debug and error messages
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
+{
+	int fd, rc;
+	FILE *memf = NULL;
+	char *membuf = NULL;
+
+	/*
+	 * For /proc/#/{mountinfo,mount} we read all file to memory and use it
+	 * as memory stream. For more details see mnt_read_procfs_file().
+	 */
+	if ((fd = fileno(f)) >= 0
+	    && (tb->fmt == MNT_FMT_GUESS ||
+		tb->fmt == MNT_FMT_MOUNTINFO ||
+		tb->fmt == MNT_FMT_MTAB)
+	    && is_procfs_fd(fd)
+	    && (memf = mnt_get_procfs_memstream(fd, &membuf))) {
+
+		rc = __table_parse_stream(tb, memf, filename);
+		fclose(memf);
+		free(membuf);
+	} else
+		rc = __table_parse_stream(tb, f, filename);
+
+	return rc;
+}
+
+/**
+ * mnt_table_parse_file:
+ * @tb: tab pointer
+ * @filename: file
+ *
+ * Parses the whole table (e.g. /etc/fstab) and appends new records to the @tab.
+ *
+ * The libmount parser ignores broken (syntax error) lines, these lines are
+ * reported to the caller by the errcb() function (see mnt_table_set_parser_errcb()).
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_table_parse_file(struct libmnt_table *tb, const char *filename)
+{
+	FILE *f;
+	int rc, fd = -1;
+
+	if (!filename || !tb)
+		return -EINVAL;
+
+	/*
+	 * Try to use read()+poll() to realiably read all
+	 * /proc/#/{mount,mountinfo} file to memory
+	 */
+	if (tb->fmt != MNT_FMT_SWAPS
+	    && strncmp(filename, "/proc/", 6) == 0) {
+
+		FILE *memf;
+		char *membuf = NULL;
+
+		fd = open(filename, O_RDONLY|O_CLOEXEC);
+		if (fd < 0) {
+			rc = -errno;
+			goto done;
+		}
+		memf = mnt_get_procfs_memstream(fd, &membuf);
+		if (memf) {
+			rc = __table_parse_stream(tb, memf, filename);
+
+			fclose(memf);
+			free(membuf);
+			close(fd);
+			goto done;
+		}
+		/* else fallback to fopen/fdopen() */
+	}
+
+	if (fd >= 0)
+		f = fdopen(fd, "r" UL_CLOEXECSTR);
+	else
+		f = fopen(filename, "r" UL_CLOEXECSTR);
+
+	if (f) {
+		rc = __table_parse_stream(tb, f, filename);
+		fclose(f);
+	} else
+		rc = -errno;
+done:
+	DBG(TAB, ul_debugobj(tb, "parsing done [filename=%s, rc=%d]", filename, rc));
+	return rc;
+}
+
+static int mnt_table_parse_dir_filter(const struct dirent *d)
+{
+	size_t namesz;
+
+#ifdef _DIRENT_HAVE_D_TYPE
+	if (d->d_type != DT_UNKNOWN && d->d_type != DT_REG &&
+	    d->d_type != DT_LNK)
+		return 0;
+#endif
+	if (*d->d_name == '.')
+		return 0;
+
+#define MNT_MNTTABDIR_EXTSIZ	(sizeof(MNT_MNTTABDIR_EXT) - 1)
+
+	namesz = strlen(d->d_name);
+	if (!namesz || namesz < MNT_MNTTABDIR_EXTSIZ + 1 ||
+	    strcmp(d->d_name + (namesz - MNT_MNTTABDIR_EXTSIZ),
+		   MNT_MNTTABDIR_EXT) != 0)
+		return 0;
+
+	/* Accept this */
+	return 1;
+}
+
+#ifdef HAVE_SCANDIRAT
+static int __mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
+{
+	int n = 0, i;
+	int dd;
+	struct dirent **namelist = NULL;
+
+	dd = open(dirname, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
+	if (dd < 0)
+	        return -errno;
+
+	n = scandirat(dd, ".", &namelist, mnt_table_parse_dir_filter, versionsort);
+	if (n <= 0) {
+	        close(dd);
+	        return 0;
+	}
+
+	for (i = 0; i < n; i++) {
+		struct dirent *d = namelist[i];
+		struct stat st;
+		FILE *f;
+
+		if (fstatat(dd, d->d_name, &st, 0) ||
+		    !S_ISREG(st.st_mode))
+			continue;
+
+		f = fopen_at(dd, d->d_name, O_RDONLY|O_CLOEXEC, "r" UL_CLOEXECSTR);
+		if (f) {
+			__table_parse_stream(tb, f, d->d_name);
+			fclose(f);
+		}
+	}
+
+	for (i = 0; i < n; i++)
+		free(namelist[i]);
+	free(namelist);
+	close(dd);
+	return 0;
+}
+#else
+static int __mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
+{
+	int n = 0, i, r = 0;
+	DIR *dir = NULL;
+	struct dirent **namelist = NULL;
+
+	n = scandir(dirname, &namelist, mnt_table_parse_dir_filter, versionsort);
+	if (n <= 0)
+		return 0;
+
+	/* let's use "at" functions rather than playing crazy games with paths... */
+	dir = opendir(dirname);
+	if (!dir) {
+		r = -errno;
+		goto out;
+	}
+
+	for (i = 0; i < n; i++) {
+		struct dirent *d = namelist[i];
+		struct stat st;
+		FILE *f;
+
+		if (fstatat(dirfd(dir), d->d_name, &st, 0) ||
+		    !S_ISREG(st.st_mode))
+			continue;
+
+		f = fopen_at(dirfd(dir), d->d_name,
+				O_RDONLY|O_CLOEXEC, "r" UL_CLOEXECSTR);
+		if (f) {
+			__table_parse_stream(tb, f, d->d_name);
+			fclose(f);
+		}
+	}
+
+out:
+	for (i = 0; i < n; i++)
+		free(namelist[i]);
+	free(namelist);
+	if (dir)
+		closedir(dir);
+	return r;
+}
+#endif
+
+/**
+ * mnt_table_parse_dir:
+ * @tb: mount table
+ * @dirname: directory
+ *
+ * The directory:
+ *	- files are sorted by strverscmp(3)
+ *	- files that start with "." are ignored (e.g. ".10foo.fstab")
+ *	- files without the ".fstab" extension are ignored
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
+{
+	return __mnt_table_parse_dir(tb, dirname);
+}
+
+struct libmnt_table *__mnt_new_table_from_file(const char *filename, int fmt, int empty_for_enoent)
+{
+	struct libmnt_table *tb;
+	struct stat st;
+
+	if (!filename)
+		return NULL;
+	if (stat(filename, &st))
+		return empty_for_enoent ? mnt_new_table() : NULL;
+
+	tb = mnt_new_table();
+	if (tb) {
+		DBG(TAB, ul_debugobj(tb, "new tab for file: %s", filename));
+		tb->fmt = fmt;
+		if (mnt_table_parse_file(tb, filename) != 0) {
+			mnt_unref_table(tb);
+			tb = NULL;
+		}
+	}
+	return tb;
+}
+
+/**
+ * mnt_new_table_from_file:
+ * @filename: /etc/{m,fs}tab or /proc/self/mountinfo path
+ *
+ * Same as mnt_new_table() + mnt_table_parse_file(). Use this function for private
+ * files only. This function does not allow using the error callback, so you
+ * cannot provide any feedback to end-users about broken records in files (e.g.
+ * fstab).
+ *
+ * Returns: newly allocated tab on success and NULL in case of error.
+ */
+struct libmnt_table *mnt_new_table_from_file(const char *filename)
+{
+	if (!filename)
+		return NULL;
+
+	return __mnt_new_table_from_file(filename, MNT_FMT_GUESS, 0);
+}
+
+/**
+ * mnt_new_table_from_dir
+ * @dirname: directory with *.fstab files
+ *
+ * Returns: newly allocated tab on success and NULL in case of error.
+ */
+struct libmnt_table *mnt_new_table_from_dir(const char *dirname)
+{
+	struct libmnt_table *tb;
+
+	if (!dirname)
+		return NULL;
+	tb = mnt_new_table();
+	if (tb && mnt_table_parse_dir(tb, dirname) != 0) {
+		mnt_unref_table(tb);
+		tb = NULL;
+	}
+	return tb;
+}
+
+/**
+ * mnt_table_set_parser_errcb:
+ * @tb: pointer to table
+ * @cb: pointer to callback function
+ *
+ * The error callback function is called by table parser (mnt_table_parse_file())
+ * in case of a syntax error. The callback function could be used for error
+ * evaluation, libmount will continue/stop parsing according to callback return
+ * codes:
+ *
+ *   <0  : fatal error (abort parsing)
+ *    0	 : success (parsing continues)
+ *   >0  : recoverable error (the line is ignored, parsing continues).
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_set_parser_errcb(struct libmnt_table *tb,
+		int (*cb)(struct libmnt_table *tb, const char *filename, int line))
+{
+	if (!tb)
+		return -EINVAL;
+	tb->errcb = cb;
+	return 0;
+}
+
+/*
+ * Filter out entries during tab file parsing. If @cb returns 1, then the entry
+ * is ignored.
+ */
+int mnt_table_set_parser_fltrcb(struct libmnt_table *tb,
+		int (*cb)(struct libmnt_fs *, void *),
+		void *data)
+{
+	if (!tb)
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "%s table parser filter", cb ? "set" : "unset"));
+	tb->fltrcb = cb;
+	tb->fltrcb_data = data;
+	return 0;
+}
+
+/**
+ * mnt_table_parse_swaps:
+ * @tb: table
+ * @filename: overwrites default (/proc/swaps or $LIBMOUNT_SWAPS) or NULL
+ *
+ * This function parses /proc/swaps and appends new lines to the @tab.
+ *
+ * See also mnt_table_set_parser_errcb().
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_parse_swaps(struct libmnt_table *tb, const char *filename)
+{
+	if (!tb)
+		return -EINVAL;
+	if (!filename) {
+		filename = mnt_get_swaps_path();
+		if (!filename)
+			return -EINVAL;
+	}
+
+	tb->fmt = MNT_FMT_SWAPS;
+
+	return mnt_table_parse_file(tb, filename);
+}
+
+/**
+ * mnt_table_parse_fstab:
+ * @tb: table
+ * @filename: overwrites default (/etc/fstab or $LIBMOUNT_FSTAB) or NULL
+ *
+ * This function parses /etc/fstab and appends new lines to the @tab. If the
+ * @filename is a directory, then mnt_table_parse_dir() is called.
+ *
+ * See also mnt_table_set_parser_errcb().
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_parse_fstab(struct libmnt_table *tb, const char *filename)
+{
+	struct stat st;
+	int rc = 0;
+
+	if (!tb)
+		return -EINVAL;
+	if (!filename)
+		filename = mnt_get_fstab_path();
+	if (!filename)
+		return -EINVAL;
+	if (stat(filename, &st) != 0)
+		return -errno;
+
+	tb->fmt = MNT_FMT_FSTAB;
+
+	if (S_ISREG(st.st_mode))
+		rc = mnt_table_parse_file(tb, filename);
+	else if (S_ISDIR(st.st_mode))
+		rc = mnt_table_parse_dir(tb, filename);
+	else
+		rc = -EINVAL;
+
+	return rc;
+}
+
+/*
+ * This function uses @uf to find a corresponding record in @tb, then the record
+ * from @tb is updated (user specific mount options are added).
+ *
+ * Note that @uf must contain only user specific mount options instead of
+ * VFS options (note that FS options are ignored).
+ *
+ * Returns modified filesystem (from @tb) or NULL.
+ */
+static struct libmnt_fs *mnt_table_merge_user_fs(struct libmnt_table *tb, struct libmnt_fs *uf)
+{
+	struct libmnt_fs *fs;
+	struct libmnt_iter itr;
+	const char *optstr, *src, *target, *root, *attrs;
+
+	if (!tb || !uf)
+		return NULL;
+
+	DBG(TAB, ul_debugobj(tb, "merging user fs"));
+
+	src = mnt_fs_get_srcpath(uf);
+	target = mnt_fs_get_target(uf);
+	optstr = mnt_fs_get_user_options(uf);
+	attrs = mnt_fs_get_attributes(uf);
+	root = mnt_fs_get_root(uf);
+
+	if (!src || !target || !root || (!attrs && !optstr))
+		return NULL;
+
+	mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
+
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		const char *r = mnt_fs_get_root(fs);
+
+		if (fs->flags & MNT_FS_MERGED)
+			continue;
+
+		if (r && strcmp(r, root) == 0
+		    && mnt_fs_streq_target(fs, target)
+		    && mnt_fs_streq_srcpath(fs, src))
+			break;
+	}
+
+	if (fs) {
+		DBG(TAB, ul_debugobj(tb, "found fs -- appending user optstr"));
+		mnt_fs_append_options(fs, optstr);
+		mnt_fs_append_attributes(fs, attrs);
+		mnt_fs_set_bindsrc(fs, mnt_fs_get_bindsrc(uf));
+		fs->flags |= MNT_FS_MERGED;
+
+		DBG(TAB, ul_debugobj(tb, "found fs:"));
+		DBG(TAB, mnt_fs_print_debug(fs, stderr));
+	}
+	return fs;
+}
+
+/* default filename is /proc/self/mountinfo
+ */
+int __mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename,
+			   struct libmnt_table *u_tb)
+{
+	int rc = 0, priv_utab = 0;
+	int explicit_file = filename ? 1 : 0;
+
+	assert(tb);
+
+	if (filename)
+		DBG(TAB, ul_debugobj(tb, "%s requested as mtab", filename));
+
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	if (mnt_has_regular_mtab(&filename, NULL)) {
+
+		DBG(TAB, ul_debugobj(tb, "force mtab usage [filename=%s]", filename));
+
+		rc = mnt_table_parse_file(tb, filename);
+
+		/*
+		 * If @filename forces us to read from /proc then also read
+		 * utab file to merge userspace mount options.
+		 */
+		if (rc == 0 && is_mountinfo(tb))
+			goto read_utab;
+
+		if (!rc)
+			return 0;
+		filename = NULL;	/* failed */
+	} else
+		filename = NULL;	/* mtab useless */
+#endif
+
+	if (!filename || strcmp(filename, _PATH_PROC_MOUNTINFO) == 0) {
+		filename = _PATH_PROC_MOUNTINFO;
+		tb->fmt = MNT_FMT_MOUNTINFO;
+		DBG(TAB, ul_debugobj(tb, "mtab parse: #1 read mountinfo"));
+	} else
+		tb->fmt = MNT_FMT_GUESS;
+
+	rc = mnt_table_parse_file(tb, filename);
+	if (rc) {
+		if (explicit_file)
+			return rc;
+
+		/* hmm, old kernel? ...try /proc/mounts */
+		tb->fmt = MNT_FMT_MTAB;
+		return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
+	}
+
+	if (!is_mountinfo(tb))
+		return 0;
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+read_utab:
+#endif
+	DBG(TAB, ul_debugobj(tb, "mtab parse: #2 read utab"));
+
+	if (mnt_table_get_nents(tb) == 0)
+		return 0;			/* empty, ignore utab */
+	/*
+	 * try to read the user specific information from /run/mount/utabs
+	 */
+	if (!u_tb) {
+		const char *utab = mnt_get_utab_path();
+
+		if (!utab || is_file_empty(utab))
+			return 0;
+
+		u_tb = mnt_new_table();
+		if (!u_tb)
+			return -ENOMEM;
+
+		u_tb->fmt = MNT_FMT_UTAB;
+		mnt_table_set_parser_fltrcb(u_tb, tb->fltrcb, tb->fltrcb_data);
+
+		rc = mnt_table_parse_file(u_tb, utab);
+		priv_utab = 1;
+	}
+
+	DBG(TAB, ul_debugobj(tb, "mtab parse: #3 merge utab"));
+
+	if (rc == 0) {
+		struct libmnt_fs *u_fs;
+		struct libmnt_iter itr;
+
+		mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
+
+		/*  merge user options into mountinfo from the kernel */
+		while(mnt_table_next_fs(u_tb, &itr, &u_fs) == 0)
+			mnt_table_merge_user_fs(tb, u_fs);
+	}
+
+
+	if (priv_utab)
+		mnt_unref_table(u_tb);
+	return 0;
+}
+/**
+ * mnt_table_parse_mtab:
+ * @tb: table
+ * @filename: overwrites default or NULL
+ *
+ * The default filename is /proc/self/mountinfo. If the mount table is a
+ * mountinfo file then /run/mount/utabs is parsed too and both files are merged
+ * to the one libmnt_table.
+ *
+ * If libmount is compiled with classic mtab file support, and the /etc/mtab is
+ * a regular file then this file is parsed.
+ *
+ * It's strongly recommended to use NULL as a @filename to keep code portable.
+ *
+ * See also mnt_table_set_parser_errcb().
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename)
+{
+	return __mnt_table_parse_mtab(tb, filename, NULL);
+}
diff --git a/libmount/src/tab_update.c b/libmount/src/tab_update.c
new file mode 100644
index 0000000..b685535
--- /dev/null
+++ b/libmount/src/tab_update.c
@@ -0,0 +1,1065 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2011-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: update
+ * @title: Tables update
+ * @short_description: userspace mount information management
+ *
+ * The struct libmnt_update provides an abstraction to manage mount options in
+ * userspace independently of system configuration. This low-level API works on
+ * systems both with and without /etc/mtab. On systems without the regular /etc/mtab
+ * file, the userspace mount options (e.g. user=) are stored in the /run/mount/utab
+ * file.
+ *
+ * It's recommended to use high-level struct libmnt_context API.
+ */
+#include <sys/file.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include "mountP.h"
+#include "mangle.h"
+#include "pathnames.h"
+
+struct libmnt_update {
+	char		*target;
+	struct libmnt_fs *fs;
+	char		*filename;
+	unsigned long	mountflags;
+	int		userspace_only;
+	int		ready;
+
+	struct libmnt_table *mountinfo;
+};
+
+static int set_fs_root(struct libmnt_update *upd, struct libmnt_fs *fs, unsigned long mountflags);
+static int utab_new_entry(struct libmnt_update *upd, struct libmnt_fs *fs, unsigned long mountflags);
+
+/**
+ * mnt_new_update:
+ *
+ * Returns: newly allocated update handler
+ */
+struct libmnt_update *mnt_new_update(void)
+{
+	struct libmnt_update *upd;
+
+	upd = calloc(1, sizeof(*upd));
+	if (!upd)
+		return NULL;
+
+	DBG(UPDATE, ul_debugobj(upd, "allocate"));
+	return upd;
+}
+
+/**
+ * mnt_free_update:
+ * @upd: update
+ *
+ * Deallocates struct libmnt_update handler.
+ */
+void mnt_free_update(struct libmnt_update *upd)
+{
+	if (!upd)
+		return;
+
+	DBG(UPDATE, ul_debugobj(upd, "free"));
+
+	mnt_unref_fs(upd->fs);
+	mnt_unref_table(upd->mountinfo);
+	free(upd->target);
+	free(upd->filename);
+	free(upd);
+}
+
+/*
+ * Returns 0 on success, <0 in case of error.
+ */
+int mnt_update_set_filename(struct libmnt_update *upd, const char *filename,
+			    int userspace_only)
+{
+	const char *path = NULL;
+	int rw = 0;
+
+	if (!upd)
+		return -EINVAL;
+
+	/* filename explicitly defined */
+	if (filename) {
+		char *p = strdup(filename);
+		if (!p)
+			return -ENOMEM;
+
+		upd->userspace_only = userspace_only;
+		free(upd->filename);
+		upd->filename = p;
+	}
+
+	if (upd->filename)
+		return 0;
+
+	/* detect tab filename -- /etc/mtab or /run/mount/utab
+	 */
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	mnt_has_regular_mtab(&path, &rw);
+#endif
+	if (!rw) {
+		path = NULL;
+		mnt_has_regular_utab(&path, &rw);
+		if (!rw)
+			return -EACCES;
+		upd->userspace_only = TRUE;
+	}
+	upd->filename = strdup(path);
+	if (!upd->filename)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * mnt_update_get_filename:
+ * @upd: update
+ *
+ * This function returns the file name (e.g. /etc/mtab) of the up-dated file.
+ *
+ * Returns: pointer to filename that will be updated or NULL in case of error.
+ */
+const char *mnt_update_get_filename(struct libmnt_update *upd)
+{
+	return upd ? upd->filename : NULL;
+}
+
+/**
+ * mnt_update_is_ready:
+ * @upd: update handler
+ *
+ * Returns: 1 if entry described by @upd is successfully prepared and will be
+ * written to the mtab/utab file.
+ */
+int mnt_update_is_ready(struct libmnt_update *upd)
+{
+	return upd ? upd->ready : FALSE;
+}
+
+/**
+ * mnt_update_set_fs:
+ * @upd: update handler
+ * @mountflags: MS_* flags
+ * @target: umount target, must be NULL for mount
+ * @fs: mount filesystem description, must be NULL for umount
+ *
+ * Returns: <0 in case on error, 0 on success, 1 if update is unnecessary.
+ */
+int mnt_update_set_fs(struct libmnt_update *upd, unsigned long mountflags,
+		      const char *target, struct libmnt_fs *fs)
+{
+	int rc;
+
+	if (!upd)
+		return -EINVAL;
+	if ((mountflags & MS_MOVE) && (!fs || !mnt_fs_get_srcpath(fs)))
+		return -EINVAL;
+	if (target && fs)
+		return -EINVAL;
+
+	DBG(UPDATE, ul_debugobj(upd,
+			"resetting FS [target=%s, flags=0x%08lx]",
+			target, mountflags));
+	if (fs) {
+		DBG(UPDATE, ul_debugobj(upd, "FS template:"));
+		DBG(UPDATE, mnt_fs_print_debug(fs, stderr));
+	}
+
+	mnt_unref_fs(upd->fs);
+	free(upd->target);
+	upd->ready = FALSE;
+	upd->fs = NULL;
+	upd->target = NULL;
+	upd->mountflags = 0;
+
+	if (mountflags & MS_PROPAGATION)
+		return 1;
+
+	upd->mountflags = mountflags;
+
+	rc = mnt_update_set_filename(upd, NULL, 0);
+	if (rc) {
+		DBG(UPDATE, ul_debugobj(upd, "no writable file available [rc=%d]", rc));
+		return rc;	/* error or no file available (rc = 1) */
+	}
+	if (target) {
+		upd->target = strdup(target);
+		if (!upd->target)
+			return -ENOMEM;
+
+	} else if (fs) {
+		if (upd->userspace_only && !(mountflags & MS_MOVE)) {
+			rc = utab_new_entry(upd, fs, mountflags);
+			if (rc)
+				return rc;
+		} else {
+			upd->fs = mnt_copy_mtab_fs(fs);
+			if (!upd->fs)
+				return -ENOMEM;
+
+		}
+	}
+
+
+	DBG(UPDATE, ul_debugobj(upd, "ready"));
+	upd->ready = TRUE;
+	return 0;
+}
+
+/**
+ * mnt_update_get_fs:
+ * @upd: update
+ *
+ * Returns: update filesystem entry or NULL
+ */
+struct libmnt_fs *mnt_update_get_fs(struct libmnt_update *upd)
+{
+	return upd ? upd->fs : NULL;
+}
+
+/**
+ * mnt_update_get_mflags:
+ * @upd: update
+ *
+ * Returns: mount flags as was set by mnt_update_set_fs()
+ */
+unsigned long mnt_update_get_mflags(struct libmnt_update *upd)
+{
+	return upd ? upd->mountflags : 0;
+}
+
+/**
+ * mnt_update_force_rdonly:
+ * @upd: update
+ * @rdonly: is read-only?
+ *
+ * Returns: 0 on success and negative number in case of error.
+ */
+int mnt_update_force_rdonly(struct libmnt_update *upd, int rdonly)
+{
+	int rc = 0;
+
+	if (!upd || !upd->fs)
+		return -EINVAL;
+
+	if (rdonly && (upd->mountflags & MS_RDONLY))
+		return 0;
+	if (!rdonly && !(upd->mountflags & MS_RDONLY))
+		return 0;
+
+	if (!upd->userspace_only) {
+		/* /etc/mtab -- we care about VFS options there */
+		const char *o = mnt_fs_get_options(upd->fs);
+		char *n = o ? strdup(o) : NULL;
+
+		if (n)
+			mnt_optstr_remove_option(&n, rdonly ? "rw" : "ro");
+		if (!mnt_optstr_prepend_option(&n, rdonly ? "ro" : "rw", NULL))
+			rc = mnt_fs_set_options(upd->fs, n);
+
+		free(n);
+	}
+
+	if (rdonly)
+		upd->mountflags &= ~MS_RDONLY;
+	else
+		upd->mountflags |= MS_RDONLY;
+
+	return rc;
+}
+
+
+/*
+ * Allocates an utab entry (upd->fs) for mount/remount. This function should be
+ * called *before* mount(2) syscall. The @fs is used as a read-only template.
+ *
+ * Returns: 0 on success, negative number on error, 1 if utab's update is
+ *          unnecessary.
+ */
+static int utab_new_entry(struct libmnt_update *upd, struct libmnt_fs *fs,
+			  unsigned long mountflags)
+{
+	int rc = 0;
+	const char *o, *a;
+	char *u = NULL;
+
+	assert(fs);
+	assert(upd);
+	assert(upd->fs == NULL);
+	assert(!(mountflags & MS_MOVE));
+
+	DBG(UPDATE, ul_debug("prepare utab entry"));
+
+	o = mnt_fs_get_user_options(fs);
+	a = mnt_fs_get_attributes(fs);
+	upd->fs = NULL;
+
+	if (o) {
+		/* remove non-mtab options */
+		rc = mnt_optstr_get_options(o, &u,
+				mnt_get_builtin_optmap(MNT_USERSPACE_MAP),
+				MNT_NOMTAB);
+		if (rc)
+			goto err;
+	}
+
+	if (!u && !a) {
+		DBG(UPDATE, ul_debug("utab entry unnecessary (no options)"));
+		return 1;
+	}
+
+	/* allocate the entry */
+	upd->fs = mnt_copy_fs(NULL, fs);
+	if (!upd->fs) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	rc = mnt_fs_set_options(upd->fs, u);
+	if (rc)
+		goto err;
+	rc = mnt_fs_set_attributes(upd->fs, a);
+	if (rc)
+		goto err;
+
+	if (!(mountflags & MS_REMOUNT)) {
+		rc = set_fs_root(upd, fs, mountflags);
+		if (rc)
+			goto err;
+	}
+
+	free(u);
+	DBG(UPDATE, ul_debug("utab entry OK"));
+	return 0;
+err:
+	free(u);
+	mnt_unref_fs(upd->fs);
+	upd->fs = NULL;
+	return rc;
+}
+
+/*
+ * Sets fs-root and fs-type to @upd->fs according to the @fs template and
+ * @mountfalgs. For MS_BIND mountflag it reads information about the source
+ * filesystem from /proc/self/mountinfo.
+ */
+static int set_fs_root(struct libmnt_update *upd, struct libmnt_fs *fs,
+		       unsigned long mountflags)
+{
+	struct libmnt_fs *src_fs;
+	char *fsroot = NULL;
+	const char *src, *fstype;
+	int rc = 0;
+
+	DBG(UPDATE, ul_debug("setting FS root"));
+
+	assert(upd);
+	assert(upd->fs);
+	assert(fs);
+
+	fstype = mnt_fs_get_fstype(fs);
+
+	if (mountflags & MS_BIND) {
+		if (!upd->mountinfo)
+			upd->mountinfo = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
+		src = mnt_fs_get_srcpath(fs);
+		if (src) {
+			 rc = mnt_fs_set_bindsrc(upd->fs, src);
+			 if (rc)
+				 goto err;
+		}
+
+	} else if (fstype && (strcmp(fstype, "btrfs") == 0 || strcmp(fstype, "auto") == 0)) {
+		if (!upd->mountinfo)
+			upd->mountinfo = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
+	}
+
+	src_fs = mnt_table_get_fs_root(upd->mountinfo, fs,
+					mountflags, &fsroot);
+	if (src_fs) {
+		src = mnt_fs_get_srcpath(src_fs);
+		rc = mnt_fs_set_source(upd->fs, src);
+		if (rc)
+			goto err;
+
+		mnt_fs_set_fstype(upd->fs, mnt_fs_get_fstype(src_fs));
+	}
+
+	upd->fs->root = fsroot;
+	return 0;
+err:
+	free(fsroot);
+	return rc;
+}
+
+/* mtab and fstab update -- returns zero on success
+ */
+static int fprintf_mtab_fs(FILE *f, struct libmnt_fs *fs)
+{
+	const char *o, *src, *fstype, *comm;
+	char *m1, *m2, *m3, *m4;
+	int rc;
+
+	assert(fs);
+	assert(f);
+
+	comm = mnt_fs_get_comment(fs);
+	src = mnt_fs_get_source(fs);
+	fstype = mnt_fs_get_fstype(fs);
+	o = mnt_fs_get_options(fs);
+
+	m1 = src ? mangle(src) : "none";
+	m2 = mangle(mnt_fs_get_target(fs));
+	m3 = fstype ? mangle(fstype) : "none";
+	m4 = o ? mangle(o) : "rw";
+
+	if (m1 && m2 && m3 && m4) {
+		if (comm)
+			fputs(comm, f);
+		rc = fprintf(f, "%s %s %s %s %d %d\n",
+				m1, m2, m3, m4,
+				mnt_fs_get_freq(fs),
+				mnt_fs_get_passno(fs));
+		if (rc > 0)
+			rc = 0;
+	} else
+		rc = -ENOMEM;
+
+	if (src)
+		free(m1);
+	free(m2);
+	if (fstype)
+		free(m3);
+	if (o)
+		free(m4);
+
+	return rc;
+}
+
+static int fprintf_utab_fs(FILE *f, struct libmnt_fs *fs)
+{
+	char *p;
+	int rc = 0;
+
+	if (!fs || !f)
+		return -EINVAL;
+
+	p = mangle(mnt_fs_get_source(fs));
+	if (p) {
+		rc = fprintf(f, "SRC=%s ", p);
+		free(p);
+	}
+	if (rc >= 0) {
+		p = mangle(mnt_fs_get_target(fs));
+		if (p) {
+			rc = fprintf(f, "TARGET=%s ", p);
+			free(p);
+		}
+	}
+	if (rc >= 0) {
+		p = mangle(mnt_fs_get_root(fs));
+		if (p) {
+			rc = fprintf(f, "ROOT=%s ", p);
+			free(p);
+		}
+	}
+	if (rc >= 0) {
+		p = mangle(mnt_fs_get_bindsrc(fs));
+		if (p) {
+			rc = fprintf(f, "BINDSRC=%s ", p);
+			free(p);
+		}
+	}
+	if (rc >= 0) {
+		p = mangle(mnt_fs_get_attributes(fs));
+		if (p) {
+			rc = fprintf(f, "ATTRS=%s ", p);
+			free(p);
+		}
+	}
+	if (rc >= 0) {
+		p = mangle(mnt_fs_get_user_options(fs));
+		if (p) {
+			rc = fprintf(f, "OPTS=%s", p);
+			free(p);
+		}
+	}
+	if (rc >= 0)
+		rc = fprintf(f, "\n");
+
+	if (rc > 0)
+		rc = 0;	/* success */
+	return rc;
+}
+
+static int update_table(struct libmnt_update *upd, struct libmnt_table *tb)
+{
+	FILE *f;
+	int rc, fd;
+	char *uq = NULL;
+
+	if (!tb || !upd->filename)
+		return -EINVAL;
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: updating", upd->filename));
+
+	fd = mnt_open_uniq_filename(upd->filename, &uq);
+	if (fd < 0)
+		return fd;	/* error */
+
+	f = fdopen(fd, "w" UL_CLOEXECSTR);
+	if (f) {
+		struct stat st;
+		struct libmnt_iter itr;
+		struct libmnt_fs *fs;
+
+		mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+		if (tb->comms && mnt_table_get_intro_comment(tb))
+			fputs(mnt_table_get_intro_comment(tb), f);
+
+		while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+			if (upd->userspace_only)
+				rc = fprintf_utab_fs(f, fs);
+			else
+				rc = fprintf_mtab_fs(f, fs);
+			if (rc) {
+				DBG(UPDATE, ul_debugobj(upd,
+					"%s: write entry failed: %m", uq));
+				goto leave;
+			}
+		}
+		if (tb->comms && mnt_table_get_trailing_comment(tb))
+			fputs(mnt_table_get_trailing_comment(tb), f);
+
+		if (fflush(f) != 0) {
+			rc = -errno;
+			DBG(UPDATE, ul_debugobj(upd, "%s: fflush failed: %m", uq));
+			goto leave;
+		}
+
+		rc = fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) ? -errno : 0;
+
+		if (!rc && stat(upd->filename, &st) == 0)
+			/* Copy uid/gid from the present file before renaming. */
+			rc = fchown(fd, st.st_uid, st.st_gid) ? -errno : 0;
+
+		fclose(f);
+		f = NULL;
+
+		if (!rc)
+			rc = rename(uq, upd->filename) ? -errno : 0;
+	} else {
+		rc = -errno;
+		close(fd);
+	}
+
+leave:
+	if (f)
+		fclose(f);
+
+	unlink(uq);	/* be paranoid */
+	free(uq);
+	DBG(UPDATE, ul_debugobj(upd, "%s: done [rc=%d]", upd->filename, rc));
+	return rc;
+}
+
+/**
+ * mnt_table_write_file
+ * @tb: parsed file (e.g. fstab)
+ * @file: target
+ *
+ * This function writes @tb to @file.
+ *
+ * Returns: 0 on success, negative number on error.
+ */
+int mnt_table_write_file(struct libmnt_table *tb, FILE *file)
+{
+	int rc = 0;
+	struct libmnt_iter itr;
+	struct libmnt_fs *fs;
+
+	if (tb->comms && mnt_table_get_intro_comment(tb))
+		fputs(mnt_table_get_intro_comment(tb), file);
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		rc = fprintf_mtab_fs(file, fs);
+		if (rc)
+			return rc;
+	}
+	if (tb->comms && mnt_table_get_trailing_comment(tb))
+		fputs(mnt_table_get_trailing_comment(tb), file);
+
+	if (fflush(file) != 0)
+		rc = -errno;
+
+	DBG(TAB, ul_debugobj(tb, "write file done [rc=%d]", rc));
+	return rc;
+}
+
+/**
+ * mnt_table_replace_file
+ * @tb: parsed file (e.g. fstab)
+ * @filename: target
+ *
+ * This function replaces @file by the new content from @tb.
+ *
+ * Returns: 0 on success, negative number on error.
+ */
+int mnt_table_replace_file(struct libmnt_table *tb, const char *filename)
+{
+	int fd, rc = 0;
+	FILE *f;
+	char *uq = NULL;
+
+	DBG(TAB, ul_debugobj(tb, "%s: replacing", filename));
+
+	fd = mnt_open_uniq_filename(filename, &uq);
+	if (fd < 0)
+		return fd;	/* error */
+
+	f = fdopen(fd, "w" UL_CLOEXECSTR);
+	if (f) {
+		struct stat st;
+
+		mnt_table_write_file(tb, f);
+
+		if (fflush(f) != 0) {
+			rc = -errno;
+			DBG(UPDATE, ul_debug("%s: fflush failed: %m", uq));
+			goto leave;
+		}
+
+		rc = fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) ? -errno : 0;
+
+		if (!rc && stat(filename, &st) == 0)
+			/* Copy uid/gid from the present file before renaming. */
+			rc = fchown(fd, st.st_uid, st.st_gid) ? -errno : 0;
+
+		fclose(f);
+		f = NULL;
+
+		if (!rc)
+			rc = rename(uq, filename) ? -errno : 0;
+	} else {
+		rc = -errno;
+		close(fd);
+	}
+
+leave:
+	if (f)
+		fclose(f);
+	unlink(uq);
+	free(uq);
+
+	DBG(TAB, ul_debugobj(tb, "replace done [rc=%d]", rc));
+	return rc;
+}
+
+static int add_file_entry(struct libmnt_table *tb, struct libmnt_update *upd)
+{
+	struct libmnt_fs *fs;
+
+	assert(upd);
+
+	fs = mnt_copy_fs(NULL, upd->fs);
+	if (!fs)
+		return -ENOMEM;
+
+	mnt_table_add_fs(tb, fs);
+	mnt_unref_fs(fs);
+
+	return update_table(upd, tb);
+}
+
+static int update_add_entry(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_table *tb;
+	int rc = 0;
+
+	assert(upd);
+	assert(upd->fs);
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: add entry", upd->filename));
+
+	if (lc)
+		rc = mnt_lock_file(lc);
+	if (rc)
+		return -MNT_ERR_LOCK;
+
+	tb = __mnt_new_table_from_file(upd->filename,
+			upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB, 1);
+	if (tb)
+		rc = add_file_entry(tb, upd);
+	if (lc)
+		mnt_unlock_file(lc);
+
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int update_remove_entry(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_table *tb;
+	int rc = 0;
+
+	assert(upd);
+	assert(upd->target);
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: remove entry", upd->filename));
+
+	if (lc)
+		rc = mnt_lock_file(lc);
+	if (rc)
+		return -MNT_ERR_LOCK;
+
+	tb = __mnt_new_table_from_file(upd->filename,
+			upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB, 1);
+	if (tb) {
+		struct libmnt_fs *rem = mnt_table_find_target(tb, upd->target, MNT_ITER_BACKWARD);
+		if (rem) {
+			mnt_table_remove_fs(tb, rem);
+			rc = update_table(upd, tb);
+		}
+	}
+	if (lc)
+		mnt_unlock_file(lc);
+
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_table *tb = NULL;
+	int rc = 0;
+
+	assert(upd);
+	DBG(UPDATE, ul_debugobj(upd, "%s: modify target", upd->filename));
+
+	if (lc)
+		rc = mnt_lock_file(lc);
+	if (rc)
+		return -MNT_ERR_LOCK;
+
+	tb = __mnt_new_table_from_file(upd->filename,
+			upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB, 1);
+	if (tb) {
+		struct libmnt_fs *cur = mnt_table_find_target(tb,
+				mnt_fs_get_srcpath(upd->fs), MNT_ITER_BACKWARD);
+		if (cur) {
+			rc = mnt_fs_set_target(cur, mnt_fs_get_target(upd->fs));
+			if (!rc)
+				rc = update_table(upd, tb);
+		}
+	}
+
+	if (lc)
+		mnt_unlock_file(lc);
+
+	mnt_unref_table(tb);
+	return rc;
+}
+
+static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_table *tb = NULL;
+	int rc = 0;
+	struct libmnt_fs *fs;
+
+	assert(upd);
+	assert(upd->fs);
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: modify options", upd->filename));
+
+	fs = upd->fs;
+
+	if (lc)
+		rc = mnt_lock_file(lc);
+	if (rc)
+		return -MNT_ERR_LOCK;
+
+	tb = __mnt_new_table_from_file(upd->filename,
+			upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB, 1);
+	if (tb) {
+		struct libmnt_fs *cur = mnt_table_find_target(tb,
+					mnt_fs_get_target(fs),
+					MNT_ITER_BACKWARD);
+		if (cur) {
+			if (upd->userspace_only)
+				rc = mnt_fs_set_attributes(cur,	mnt_fs_get_attributes(fs));
+			if (!rc)
+				rc = mnt_fs_set_options(cur, mnt_fs_get_options(fs));
+			if (!rc)
+				rc = update_table(upd, tb);
+		} else
+			rc = add_file_entry(tb, upd);	/* not found, add new */
+	}
+
+	if (lc)
+		mnt_unlock_file(lc);
+
+	mnt_unref_table(tb);
+	return rc;
+}
+
+/**
+ * mnt_update_table:
+ * @upd: update
+ * @lc: lock or NULL
+ *
+ * High-level API to update /etc/mtab (or private /run/mount/utab file).
+ *
+ * The @lc lock is optional and will be created if necessary. Note that
+ * an automatically created lock blocks all signals.
+ *
+ * See also mnt_lock_block_signals() and mnt_context_get_lock().
+ *
+ * Returns: 0 on success, negative number on error.
+ */
+int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_lock *lc0 = lc;
+	int rc = -EINVAL;
+
+	if (!upd || !upd->filename)
+		return -EINVAL;
+	if (!upd->ready)
+		return 0;
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: update tab", upd->filename));
+	if (upd->fs) {
+		DBG(UPDATE, mnt_fs_print_debug(upd->fs, stderr));
+	}
+	if (!lc) {
+		lc = mnt_new_lock(upd->filename, 0);
+		if (lc)
+			mnt_lock_block_signals(lc, TRUE);
+	}
+	if (lc && upd->userspace_only)
+		mnt_lock_use_simplelock(lc, TRUE);	/* use flock */
+
+	if (!upd->fs && upd->target)
+		rc = update_remove_entry(upd, lc);	/* umount */
+	else if (upd->mountflags & MS_MOVE)
+		rc = update_modify_target(upd, lc);	/* move */
+	else if (upd->mountflags & MS_REMOUNT)
+		rc = update_modify_options(upd, lc);	/* remount */
+	else if (upd->fs)
+		rc = update_add_entry(upd, lc);	/* mount */
+
+	upd->ready = FALSE;
+	DBG(UPDATE, ul_debugobj(upd, "%s: update tab: done [rc=%d]",
+				upd->filename, rc));
+	if (lc != lc0)
+		 mnt_free_lock(lc);
+	return rc;
+}
+
+int mnt_update_already_done(struct libmnt_update *upd, struct libmnt_lock *lc)
+{
+	struct libmnt_table *tb = NULL;
+	struct libmnt_lock *lc0 = lc;
+	int rc = 0;
+
+	if (!upd || !upd->filename || (!upd->fs && !upd->target))
+		return -EINVAL;
+
+	DBG(UPDATE, ul_debugobj(upd, "%s: checking for previous update", upd->filename));
+
+	if (!lc) {
+		lc = mnt_new_lock(upd->filename, 0);
+		if (lc)
+			mnt_lock_block_signals(lc, TRUE);
+	}
+	if (lc && upd->userspace_only)
+		mnt_lock_use_simplelock(lc, TRUE);	/* use flock */
+	if (lc) {
+		rc = mnt_lock_file(lc);
+		if (rc) {
+			rc = -MNT_ERR_LOCK;
+			goto done;
+		}
+	}
+
+	tb = __mnt_new_table_from_file(upd->filename,
+			upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB, 1);
+	if (lc)
+		mnt_unlock_file(lc);
+	if (!tb)
+		goto done;
+
+	if (upd->fs) {
+		/* mount */
+		const char *tgt = mnt_fs_get_target(upd->fs);
+		const char *src = mnt_fs_get_bindsrc(upd->fs) ?
+					mnt_fs_get_bindsrc(upd->fs) :
+					mnt_fs_get_source(upd->fs);
+
+		if (mnt_table_find_pair(tb, src, tgt, MNT_ITER_BACKWARD)) {
+			DBG(UPDATE, ul_debugobj(upd, "%s: found %s %s",
+						upd->filename, src, tgt));
+			rc = 1;
+		}
+	} else if (upd->target) {
+		/* umount */
+		if (!mnt_table_find_target(tb, upd->target, MNT_ITER_BACKWARD)) {
+			DBG(UPDATE, ul_debugobj(upd, "%s: not-found (umounted) %s",
+						upd->filename, upd->target));
+			rc = 1;
+		}
+	}
+
+	mnt_unref_table(tb);
+done:
+	if (lc && lc != lc0)
+		mnt_free_lock(lc);
+	DBG(UPDATE, ul_debugobj(upd, "%s: previous update check done [rc=%d]",
+				upd->filename, rc));
+	return rc;
+}
+
+
+#ifdef TEST_PROGRAM
+
+static int update(const char *target, struct libmnt_fs *fs, unsigned long mountflags)
+{
+	int rc;
+	struct libmnt_update *upd;
+
+	DBG(UPDATE, ul_debug("update test"));
+
+	upd = mnt_new_update();
+	if (!upd)
+		return -ENOMEM;
+
+	rc = mnt_update_set_fs(upd, mountflags, target, fs);
+	if (rc == 1) {
+		/* update is unnecessary */
+		rc = 0;
+		goto done;
+	}
+	if (rc) {
+		fprintf(stderr, "failed to set FS\n");
+		goto done;
+	}
+
+	/* [... mount(2) call should be here...]  */
+
+	rc = mnt_update_table(upd, NULL);
+done:
+	mnt_free_update(upd);
+	return rc;
+}
+
+static int test_add(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_fs *fs = mnt_new_fs();
+	int rc;
+
+	if (argc < 5 || !fs)
+		return -1;
+	mnt_fs_set_source(fs, argv[1]);
+	mnt_fs_set_target(fs, argv[2]);
+	mnt_fs_set_fstype(fs, argv[3]);
+	mnt_fs_set_options(fs, argv[4]);
+
+	rc = update(NULL, fs, 0);
+	mnt_unref_fs(fs);
+	return rc;
+}
+
+static int test_remove(struct libmnt_test *ts, int argc, char *argv[])
+{
+	if (argc < 2)
+		return -1;
+	return update(argv[1], NULL, 0);
+}
+
+static int test_move(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_fs *fs = mnt_new_fs();
+	int rc;
+
+	if (argc < 3)
+		return -1;
+	mnt_fs_set_source(fs, argv[1]);
+	mnt_fs_set_target(fs, argv[2]);
+
+	rc = update(NULL, fs, MS_MOVE);
+
+	mnt_unref_fs(fs);
+	return rc;
+}
+
+static int test_remount(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_fs *fs = mnt_new_fs();
+	int rc;
+
+	if (argc < 3)
+		return -1;
+	mnt_fs_set_target(fs, argv[1]);
+	mnt_fs_set_options(fs, argv[2]);
+
+	rc = update(NULL, fs, MS_REMOUNT);
+	mnt_unref_fs(fs);
+	return rc;
+}
+
+static int test_replace(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct libmnt_fs *fs = mnt_new_fs();
+	struct libmnt_table *tb = mnt_new_table();
+	int rc;
+
+	if (argc < 3)
+		return -1;
+
+	mnt_table_enable_comments(tb, TRUE);
+	mnt_table_parse_fstab(tb, NULL);
+
+	mnt_fs_set_source(fs, argv[1]);
+	mnt_fs_set_target(fs, argv[2]);
+	mnt_fs_append_comment(fs, "# this is new filesystem\n");
+
+	mnt_table_add_fs(tb, fs);
+	mnt_unref_fs(fs);
+
+	rc = mnt_table_replace_file(tb, mnt_get_fstab_path());
+	mnt_unref_table(tb);
+	return rc;
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+	{ "--add",    test_add,     "<src> <target> <type> <options>  add a line to mtab" },
+	{ "--remove", test_remove,  "<target>                      MS_REMOUNT mtab change" },
+	{ "--move",   test_move,    "<old_target>  <target>        MS_MOVE mtab change" },
+	{ "--remount",test_remount, "<target>  <options>           MS_REMOUNT mtab change" },
+	{ "--replace",test_replace, "<src> <target>                Add a line to LIBMOUNT_FSTAB and replace the original file" },
+	{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/test.c b/libmount/src/test.c
new file mode 100644
index 0000000..0e3388c
--- /dev/null
+++ b/libmount/src/test.c
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ *
+ * Routines for TEST_PROGRAMs
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#ifndef TEST_PROGRAM
+#define TEST_PROGRAM
+#endif
+
+#include "mountP.h"
+
+int mnt_run_test(struct libmnt_test *tests, int argc, char *argv[])
+{
+	int rc = -1;
+	struct libmnt_test *ts;
+
+	assert(tests);
+	assert(argc);
+	assert(argv);
+
+	if (argc < 2 ||
+	    strcmp(argv[1], "--help") == 0 ||
+	    strcmp(argv[1], "-h") == 0)
+		goto usage;
+
+	mnt_init_debug(0);
+
+	for (ts = tests; ts->name; ts++) {
+		if (strcmp(ts->name, argv[1]) == 0) {
+			rc = ts->body(ts, argc - 1, argv + 1);
+			if (rc)
+				printf("FAILED [rc=%d]", rc);
+			break;
+		}
+	}
+
+	if (rc < 0 && ts->name == NULL)
+		goto usage;
+
+	return rc == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+usage:
+	printf("\nUsage:\n\t%s <test> [testoptions]\nTests:\n",
+			program_invocation_short_name);
+	for (ts = tests; ts->name; ts++) {
+		printf("\t%-15s", ts->name);
+		if (ts->usage)
+			printf(" %s\n", ts->usage);
+	}
+	printf("\n");
+	return EXIT_FAILURE;
+}
diff --git a/libmount/src/utils.c b/libmount/src/utils.c
new file mode 100644
index 0000000..92829eb
--- /dev/null
+++ b/libmount/src/utils.c
@@ -0,0 +1,1524 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: utils
+ * @title: Utils
+ * @short_description: misc utils.
+ */
+#include <ctype.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+#include <poll.h>
+#include <blkid.h>
+
+#include "strutils.h"
+#include "pathnames.h"
+#include "mountP.h"
+#include "mangle.h"
+#include "canonicalize.h"
+#include "env.h"
+#include "match.h"
+#include "fileutils.h"
+#include "statfs_magic.h"
+#include "sysfs.h"
+
+int append_string(char **a, const char *b)
+{
+	size_t al, bl;
+	char *tmp;
+
+	assert(a);
+
+	if (!b || !*b)
+		return 0;
+	if (!*a) {
+		*a = strdup(b);
+		return !*a ? -ENOMEM : 0;
+	}
+
+	al = strlen(*a);
+	bl = strlen(b);
+
+	tmp = realloc(*a, al + bl + 1);
+	if (!tmp)
+		return -ENOMEM;
+	*a = tmp;
+	memcpy((*a) + al, b, bl + 1);
+	return 0;
+}
+
+/*
+ * Return 1 if the file is not accessible or empty
+ */
+int is_file_empty(const char *name)
+{
+	struct stat st;
+	assert(name);
+
+	return (stat(name, &st) != 0 || st.st_size == 0);
+}
+
+int mnt_valid_tagname(const char *tagname)
+{
+	if (tagname && *tagname && (
+	    strcmp("ID", tagname) == 0 ||
+	    strcmp("UUID", tagname) == 0 ||
+	    strcmp("LABEL", tagname) == 0 ||
+	    strcmp("PARTUUID", tagname) == 0 ||
+	    strcmp("PARTLABEL", tagname) == 0))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * mnt_tag_is_valid:
+ * @tag: NAME=value string
+ *
+ * Returns: 1 if the @tag is parsable and tag NAME= is supported by libmount, or 0.
+ */
+int mnt_tag_is_valid(const char *tag)
+{
+	char *t = NULL;
+	int rc = tag && blkid_parse_tag_string(tag, &t, NULL) == 0
+		     && mnt_valid_tagname(t);
+
+	free(t);
+	return rc;
+}
+
+int mnt_parse_offset(const char *str, size_t len, uintmax_t *res)
+{
+	char *p;
+	int rc = 0;
+
+	if (!str || !*str)
+		return -EINVAL;
+
+	p = strndup(str, len);
+	if (!p)
+		return -errno;
+
+	if (strtosize(p, res))
+		rc = -EINVAL;
+	free(p);
+	return rc;
+}
+
+/* used as a callback by bsearch in mnt_fstype_is_pseudofs() */
+static int fstype_cmp(const void *v1, const void *v2)
+{
+	const char *s1 = *(char * const *)v1;
+	const char *s2 = *(char * const *)v2;
+
+	return strcmp(s1, s2);
+}
+
+int mnt_stat_mountpoint(const char *target, struct stat *st)
+{
+#ifdef AT_NO_AUTOMOUNT
+	return fstatat(AT_FDCWD, target, st, AT_NO_AUTOMOUNT);
+#else
+	return stat(target, st);
+#endif
+}
+
+int mnt_lstat_mountpoint(const char *target, struct stat *st)
+{
+#ifdef AT_NO_AUTOMOUNT
+	return fstatat(AT_FDCWD, target, st, AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW);
+#else
+	return lstat(target, st);
+#endif
+}
+
+
+/*
+ * Note that the @target has to be an absolute path (so at least "/").  The
+ * @filename returns an allocated buffer with the last path component, for example:
+ *
+ * mnt_chdir_to_parent("/mnt/test", &buf) ==> chdir("/mnt"), buf="test"
+ */
+int mnt_chdir_to_parent(const char *target, char **filename)
+{
+	char *buf, *parent, *last = NULL;
+	char cwd[PATH_MAX];
+	int rc = -EINVAL;
+
+	if (!target || *target != '/')
+		return -EINVAL;
+
+	DBG(UTILS, ul_debug("moving to %s parent", target));
+
+	buf = strdup(target);
+	if (!buf)
+		return -ENOMEM;
+
+	if (*(buf + 1) != '\0') {
+		last = stripoff_last_component(buf);
+		if (!last)
+			goto err;
+	}
+
+	parent = buf && *buf ? buf : "/";
+
+	if (chdir(parent) == -1) {
+		DBG(UTILS, ul_debug("failed to chdir to %s: %m", parent));
+		rc = -errno;
+		goto err;
+	}
+	if (!getcwd(cwd, sizeof(cwd))) {
+		DBG(UTILS, ul_debug("failed to obtain current directory: %m"));
+		rc = -errno;
+		goto err;
+	}
+	if (strcmp(cwd, parent) != 0) {
+		DBG(UTILS, ul_debug(
+		    "unexpected chdir (expected=%s, cwd=%s)", parent, cwd));
+		goto err;
+	}
+
+	DBG(CXT, ul_debug(
+		"current directory moved to %s [last_component='%s']",
+		parent, last));
+
+	if (filename) {
+		*filename = buf;
+
+		if (!last || !*last)
+			memcpy(*filename, ".", 2);
+		else
+			memmove(*filename, last, strlen(last) + 1);
+	} else
+		free(buf);
+	return 0;
+err:
+	free(buf);
+	return rc;
+}
+
+/*
+ * Check if @path is on a read-only filesystem independently of file permissions.
+ */
+int mnt_is_readonly(const char *path)
+{
+	if (access(path, W_OK) == 0)
+		return 0;
+	if (errno == EROFS)
+		return 1;
+	if (errno != EACCES)
+		return 0;
+
+#ifdef HAVE_UTIMENSAT
+	/*
+	 * access(2) returns EACCES on read-only FS:
+	 *
+	 * - for set-uid application if one component of the path is not
+	 *   accessible for the current rUID. (Note that euidaccess(2) does not
+	 *   check for EROFS at all).
+	 *
+	 * - for a read-write filesystem with a read-only VFS node (aka -o remount,ro,bind)
+	 */
+	{
+		struct timespec times[2];
+
+		DBG(UTILS, ul_debug(" doing utimensat() based write test"));
+
+		times[0].tv_nsec = UTIME_NOW;	/* atime */
+		times[1].tv_nsec = UTIME_OMIT;	/* mtime */
+
+		if (utimensat(AT_FDCWD, path, times, 0) == -1)
+			return errno == EROFS;
+	}
+#endif
+	return 0;
+}
+
+/**
+ * mnt_mangle:
+ * @str: string
+ *
+ * Encode @str to be compatible with fstab/mtab
+ *
+ * Returns: newly allocated string or NULL in case of error.
+ */
+char *mnt_mangle(const char *str)
+{
+	return mangle(str);
+}
+
+/**
+ * mnt_unmangle:
+ * @str: string
+ *
+ * Decode @str from fstab/mtab
+ *
+ * Returns: newly allocated string or NULL in case of error.
+ */
+char *mnt_unmangle(const char *str)
+{
+	return unmangle(str, NULL);
+}
+
+/**
+ * mnt_fstype_is_pseudofs:
+ * @type: filesystem name
+ *
+ * Returns: 1 for filesystems like proc, sysfs, ... or 0.
+ */
+int mnt_fstype_is_pseudofs(const char *type)
+{
+	/* This array must remain sorted when adding new fstypes */
+	static const char *pseudofs[] = {
+		"anon_inodefs",
+		"apparmorfs",
+		"autofs",
+		"bdev",
+		"binder",
+		"binfmt_misc",
+		"bpf",
+		"cgroup",
+		"cgroup2",
+		"configfs",
+		"cpuset",
+		"debugfs",
+		"devfs",
+		"devpts",
+		"devtmpfs",
+		"dlmfs",
+		"dmabuf",
+		"drm",
+		"efivarfs",
+		"fuse", /* Fallback name of fuse used by many poorly written drivers. */
+		"fuse.archivemount", /* Not a true pseudofs (has source), but source is not reported. */
+		"fuse.avfsd", /* Not a true pseudofs (has source), but source is not reported. */
+		"fuse.dumpfs", /* In fact, it is a netfs, but source is not reported. */
+		"fuse.encfs", /* Not a true pseudofs (has source), but source is not reported. */
+		"fuse.gvfs-fuse-daemon", /* Old name, not used by gvfs any more. */
+		"fuse.gvfsd-fuse",
+		"fuse.lxcfs",
+		"fuse.rofiles-fuse",
+		"fuse.vmware-vmblock",
+		"fuse.xwmfs",
+		"fusectl",
+		"hugetlbfs",
+		"ipathfs",
+		"mqueue",
+		"nfsd",
+		"none",
+		"nsfs",
+		"overlay",
+		"pipefs",
+		"proc",
+		"pstore",
+		"ramfs",
+		"resctrl",
+		"rootfs",
+		"rpc_pipefs",
+		"securityfs",
+		"selinuxfs",
+		"smackfs",
+		"sockfs",
+		"spufs",
+		"sysfs",
+		"tmpfs",
+		"tracefs"
+	};
+
+	assert(type);
+
+	return !(bsearch(&type, pseudofs, ARRAY_SIZE(pseudofs),
+				sizeof(char*), fstype_cmp) == NULL);
+}
+
+/**
+ * mnt_fstype_is_netfs:
+ * @type: filesystem name
+ *
+ * Returns: 1 for filesystems like cifs, nfs, ... or 0.
+ */
+int mnt_fstype_is_netfs(const char *type)
+{
+	if (strcmp(type, "cifs")   == 0 ||
+	    strcmp(type, "smb3")   == 0 ||
+	    strcmp(type, "smbfs")  == 0 ||
+	    strncmp(type,"nfs", 3) == 0 ||
+	    strcmp(type, "afs")    == 0 ||
+	    strcmp(type, "ncpfs")  == 0 ||
+	    strcmp(type, "fuse.curlftpfs") == 0 ||
+	    strcmp(type, "fuse.sshfs") == 0 ||
+	    strncmp(type,"9p", 2)  == 0)
+		return 1;
+	return 0;
+}
+
+const char *mnt_statfs_get_fstype(struct statfs *vfs)
+{
+	assert(vfs);
+
+	switch (vfs->f_type) {
+	case STATFS_ADFS_MAGIC:		return "adfs";
+	case STATFS_AFFS_MAGIC:		return "affs";
+	case STATFS_AFS_MAGIC:		return "afs";
+	case STATFS_AUTOFS_MAGIC:	return "autofs";
+	case STATFS_BDEVFS_MAGIC:	return "bdev";
+	case STATFS_BEFS_MAGIC:		return "befs";
+	case STATFS_BFS_MAGIC:		return "befs";
+	case STATFS_BINFMTFS_MAGIC:	return "binfmt_misc";
+	case STATFS_BTRFS_MAGIC:	return "btrfs";
+	case STATFS_CEPH_MAGIC:		return "ceph";
+	case STATFS_CGROUP_MAGIC:	return "cgroup";
+	case STATFS_CIFS_MAGIC:		return "cifs";
+	case STATFS_CODA_MAGIC:		return "coda";
+	case STATFS_CONFIGFS_MAGIC:	return "configfs";
+	case STATFS_CRAMFS_MAGIC:	return "cramfs";
+	case STATFS_DEBUGFS_MAGIC:	return "debugfs";
+	case STATFS_DEVPTS_MAGIC:	return "devpts";
+	case STATFS_ECRYPTFS_MAGIC:	return "ecryptfs";
+	case STATFS_EFIVARFS_MAGIC:	return "efivarfs";
+	case STATFS_EFS_MAGIC:		return "efs";
+	case STATFS_EXOFS_MAGIC:	return "exofs";
+	case STATFS_EXT4_MAGIC:		return "ext4";	   /* all extN use the same magic */
+	case STATFS_F2FS_MAGIC:		return "f2fs";
+	case STATFS_FUSE_MAGIC:		return "fuse";
+	case STATFS_FUTEXFS_MAGIC:	return "futexfs";
+	case STATFS_GFS2_MAGIC:		return "gfs2";
+	case STATFS_HFSPLUS_MAGIC:	return "hfsplus";
+	case STATFS_HOSTFS_MAGIC:	return "hostfs";
+	case STATFS_HPFS_MAGIC:		return "hpfs";
+	case STATFS_HPPFS_MAGIC:	return "hppfs";
+	case STATFS_HUGETLBFS_MAGIC:	return "hugetlbfs";
+	case STATFS_ISOFS_MAGIC:	return "iso9660";
+	case STATFS_JFFS2_MAGIC:	return "jffs2";
+	case STATFS_JFS_MAGIC:		return "jfs";
+	case STATFS_LOGFS_MAGIC:	return "logfs";
+	case STATFS_MINIX2_MAGIC:
+	case STATFS_MINIX2_MAGIC2:
+	case STATFS_MINIX3_MAGIC:
+	case STATFS_MINIX_MAGIC:
+	case STATFS_MINIX_MAGIC2:	return "minix";
+	case STATFS_MQUEUE_MAGIC:	return "mqueue";
+	case STATFS_MSDOS_MAGIC:	return "vfat";
+	case STATFS_NCP_MAGIC:		return "ncp";
+	case STATFS_NFS_MAGIC:		return "nfs";
+	case STATFS_NILFS_MAGIC:	return "nilfs2";
+	case STATFS_NTFS_MAGIC:		return "ntfs";
+	case STATFS_OCFS2_MAGIC:	return "ocfs2";
+	case STATFS_OMFS_MAGIC:		return "omfs";
+	case STATFS_OPENPROMFS_MAGIC:	return "openpromfs";
+	case STATFS_PIPEFS_MAGIC:	return "pipefs";
+	case STATFS_PROC_MAGIC:		return "proc";
+	case STATFS_PSTOREFS_MAGIC:	return "pstore";
+	case STATFS_QNX4_MAGIC:		return "qnx4";
+	case STATFS_QNX6_MAGIC:		return "qnx6";
+	case STATFS_RAMFS_MAGIC:	return "ramfs";
+	case STATFS_REISERFS_MAGIC:	return "reiser4";
+	case STATFS_ROMFS_MAGIC:	return "romfs";
+	case STATFS_SECURITYFS_MAGIC:	return "securityfs";
+	case STATFS_SELINUXFS_MAGIC:	return "selinuxfs";
+	case STATFS_SMACKFS_MAGIC:	return "smackfs";
+	case STATFS_SMB_MAGIC:		return "smb";
+	case STATFS_SOCKFS_MAGIC:	return "sockfs";
+	case STATFS_SQUASHFS_MAGIC:	return "squashfs";
+	case STATFS_SYSFS_MAGIC:	return "sysfs";
+	case STATFS_TMPFS_MAGIC:	return "tmpfs";
+	case STATFS_UBIFS_MAGIC:	return "ubifs";
+	case STATFS_UDF_MAGIC:		return "udf";
+	case STATFS_UFS2_MAGIC:
+	case STATFS_UFS_MAGIC:		return "ufs";
+	case STATFS_V9FS_MAGIC:		return "9p";
+	case STATFS_VXFS_MAGIC:		return "vxfs";
+	case STATFS_XENFS_MAGIC:	return "xenfs";
+	case STATFS_XFS_MAGIC:		return "xfs";
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+int is_procfs_fd(int fd)
+{
+	struct statfs sfs;
+
+	return fstatfs(fd, &sfs) == 0 && sfs.f_type == STATFS_PROC_MAGIC;
+}
+
+/**
+ * mnt_match_fstype:
+ * @type: filesystem type
+ * @pattern: filesystem name or comma delimited list of names
+ *
+ * The @pattern list of filesystems can be prefixed with a global
+ * "no" prefix to invert matching of the whole list. The "no" could
+ * also be used for individual items in the @pattern list. So,
+ * "nofoo,bar" has the same meaning as "nofoo,nobar".
+ *
+ * "bar"  : "nofoo,bar"		-> False   (global "no" prefix)
+ *
+ * "bar"  : "foo,bar"		-> True
+ *
+ * "bar" : "foo,nobar"		-> False
+ *
+ * Returns: 1 if type is matching, else 0. This function also returns
+ *          0 if @pattern is NULL and @type is non-NULL.
+ */
+int mnt_match_fstype(const char *type, const char *pattern)
+{
+	return match_fstype(type, pattern);
+}
+
+void mnt_free_filesystems(char **filesystems)
+{
+	char **p;
+
+	if (!filesystems)
+		return;
+	for (p = filesystems; *p; p++)
+		free(*p);
+	free(filesystems);
+}
+
+static int add_filesystem(char ***filesystems, char *name)
+{
+	int n = 0;
+
+	assert(filesystems);
+	assert(name);
+
+	if (*filesystems) {
+		char **p;
+		for (n = 0, p = *filesystems; *p; p++, n++) {
+			if (strcmp(*p, name) == 0)
+				return 0;
+		}
+	}
+
+	#define MYCHUNK	16
+
+	if (n == 0 || !((n + 1) % MYCHUNK)) {
+		size_t items = ((n + 1 + MYCHUNK) / MYCHUNK) * MYCHUNK;
+		char **x = realloc(*filesystems, items * sizeof(char *));
+
+		if (!x)
+			goto err;
+		*filesystems = x;
+	}
+	name = strdup(name);
+	(*filesystems)[n] = name;
+	(*filesystems)[n + 1] = NULL;
+	if (!name)
+		goto err;
+	return 0;
+err:
+	mnt_free_filesystems(*filesystems);
+	return -ENOMEM;
+}
+
+static int get_filesystems(const char *filename, char ***filesystems, const char *pattern)
+{
+	int rc = 0;
+	FILE *f;
+	char line[129];
+
+	f = fopen(filename, "r" UL_CLOEXECSTR);
+	if (!f)
+		return 1;
+
+	DBG(UTILS, ul_debug("reading filesystems list from: %s", filename));
+
+	while (fgets(line, sizeof(line), f)) {
+		char name[sizeof(line)];
+
+		if (*line == '#' || strncmp(line, "nodev", 5) == 0)
+			continue;
+		if (sscanf(line, " %128[^\n ]\n", name) != 1)
+			continue;
+		if (strcmp(name, "*") == 0) {
+			rc = 1;
+			break;		/* end of the /etc/filesystems */
+		}
+		if (pattern && !mnt_match_fstype(name, pattern))
+			continue;
+		rc = add_filesystem(filesystems, name);
+		if (rc)
+			break;
+	}
+
+	fclose(f);
+	return rc;
+}
+
+/*
+ * Always check the @filesystems pointer!
+ *
+ * man mount:
+ *
+ * ...mount will try to read the file /etc/filesystems, or, if that does not
+ * exist, /proc/filesystems. All of the filesystem  types  listed  there  will
+ * be tried,  except  for  those  that  are  labeled  "nodev"  (e.g.,  devpts,
+ * proc  and  nfs).  If /etc/filesystems ends in a line with a single * only,
+ * mount will read /proc/filesystems afterwards.
+ */
+int mnt_get_filesystems(char ***filesystems, const char *pattern)
+{
+	int rc;
+
+	if (!filesystems)
+		return -EINVAL;
+
+	*filesystems = NULL;
+
+	rc = get_filesystems(_PATH_FILESYSTEMS, filesystems, pattern);
+	if (rc != 1)
+		return rc;
+
+	rc = get_filesystems(_PATH_PROC_FILESYSTEMS, filesystems, pattern);
+	if (rc == 1 && *filesystems)
+		rc = 0;			/* /proc/filesystems not found */
+
+	return rc;
+}
+
+/*
+ * Returns an allocated string with username or NULL.
+ */
+char *mnt_get_username(const uid_t uid)
+{
+        struct passwd pwd;
+	struct passwd *res;
+	char *buf, *username = NULL;
+
+	buf = malloc(UL_GETPW_BUFSIZ);
+	if (!buf)
+		return NULL;
+
+	if (!getpwuid_r(uid, &pwd, buf, UL_GETPW_BUFSIZ, &res) && res)
+		username = strdup(pwd.pw_name);
+
+	free(buf);
+	return username;
+}
+
+int mnt_get_uid(const char *username, uid_t *uid)
+{
+	int rc = -1;
+        struct passwd pwd;
+	struct passwd *pw;
+	char *buf;
+
+	if (!username || !uid)
+		return -EINVAL;
+
+	buf = malloc(UL_GETPW_BUFSIZ);
+	if (!buf)
+		return -ENOMEM;
+
+	if (!getpwnam_r(username, &pwd, buf, UL_GETPW_BUFSIZ, &pw) && pw) {
+		*uid= pw->pw_uid;
+		rc = 0;
+	} else {
+		DBG(UTILS, ul_debug(
+			"cannot convert '%s' username to UID", username));
+		rc = errno ? -errno : -EINVAL;
+	}
+
+	free(buf);
+	return rc;
+}
+
+int mnt_get_gid(const char *groupname, gid_t *gid)
+{
+	int rc = -1;
+        struct group grp;
+	struct group *gr;
+	char *buf;
+
+	if (!groupname || !gid)
+		return -EINVAL;
+
+	buf = malloc(UL_GETPW_BUFSIZ);
+	if (!buf)
+		return -ENOMEM;
+
+	if (!getgrnam_r(groupname, &grp, buf, UL_GETPW_BUFSIZ, &gr) && gr) {
+		*gid= gr->gr_gid;
+		rc = 0;
+	} else {
+		DBG(UTILS, ul_debug(
+			"cannot convert '%s' groupname to GID", groupname));
+		rc = errno ? -errno : -EINVAL;
+	}
+
+	free(buf);
+	return rc;
+}
+
+int mnt_in_group(gid_t gid)
+{
+	int rc = 0, n, i;
+	gid_t *grps = NULL;
+
+	if (getgid() == gid)
+		return 1;
+
+	n = getgroups(0, NULL);
+	if (n <= 0)
+		goto done;
+
+	grps = malloc(n * sizeof(*grps));
+	if (!grps)
+		goto done;
+
+	if (getgroups(n, grps) == n) {
+		for (i = 0; i < n; i++) {
+			if (grps[i] == gid) {
+				rc = 1;
+				break;
+			}
+		}
+	}
+done:
+	free(grps);
+	return rc;
+}
+
+static int try_write(const char *filename, const char *directory)
+{
+	int rc = 0;
+
+	if (!filename)
+		return -EINVAL;
+
+	DBG(UTILS, ul_debug("try write %s dir: %s", filename, directory));
+
+#ifdef HAVE_EACCESS
+	/* Try eaccess() first, because open() is overkill, may be monitored by
+	 * audit and we don't want to fill logs by our checks...
+	 */
+	if (eaccess(filename, R_OK|W_OK) == 0) {
+		DBG(UTILS, ul_debug(" access OK"));
+		return 0;
+	}
+
+	if (errno != ENOENT) {
+		DBG(UTILS, ul_debug(" access FAILED"));
+		return -errno;
+	}
+
+	if (directory) {
+		/* file does not exist; try if directory is writable */
+		if (eaccess(directory, R_OK|W_OK) != 0)
+			rc = -errno;
+
+		DBG(UTILS, ul_debug(" access %s [%s]", rc ? "FAILED" : "OK", directory));
+		return rc;
+	}
+#endif
+
+	DBG(UTILS, ul_debug(" doing open-write test"));
+
+	int fd = open(filename, O_RDWR|O_CREAT|O_CLOEXEC,
+		    S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH);
+	if (fd < 0)
+		rc = -errno;
+	else
+		close(fd);
+
+	return rc;
+}
+
+/**
+ * mnt_has_regular_mtab:
+ * @mtab: returns path to mtab
+ * @writable: returns 1 if the file is writable
+ *
+ * If the file does not exist and @writable argument is not NULL, then it will
+ * try to create the file.
+ *
+ * Returns: 1 if /etc/mtab is a regular file, and 0 in case of error (check
+ *          errno for more details).
+ */
+int mnt_has_regular_mtab(const char **mtab, int *writable)
+{
+	struct stat st;
+	int rc;
+	const char *filename = mtab && *mtab ? *mtab : mnt_get_mtab_path();
+
+	if (writable)
+		*writable = 0;
+	if (mtab && !*mtab)
+		*mtab = filename;
+
+	DBG(UTILS, ul_debug("mtab: %s", filename));
+
+	rc = lstat(filename, &st);
+
+	if (rc == 0) {
+		/* file exists */
+		if (S_ISREG(st.st_mode)) {
+			if (writable)
+				*writable = !try_write(filename, NULL);
+			DBG(UTILS, ul_debug("%s: writable", filename));
+			return 1;
+		}
+		goto done;
+	}
+
+	/* try to create the file */
+	if (writable) {
+		*writable = !try_write(filename, NULL);
+		if (*writable) {
+			DBG(UTILS, ul_debug("%s: writable", filename));
+			return 1;
+		}
+	}
+
+done:
+	DBG(UTILS, ul_debug("%s: irregular/non-writable", filename));
+	return 0;
+}
+
+/*
+ * Don't export this to libmount API -- utab is private library stuff.
+ *
+ * If the file does not exist and @writable argument is not NULL, then it will
+ * try to create the directory (e.g. /run/mount) and the file.
+ *
+ * Returns: 1 if utab is a regular file, and 0 in case of
+ *          error (check errno for more details).
+ */
+int mnt_has_regular_utab(const char **utab, int *writable)
+{
+	struct stat st;
+	int rc;
+	const char *filename = utab && *utab ? *utab : mnt_get_utab_path();
+
+	if (writable)
+		*writable = 0;
+	if (utab && !*utab)
+		*utab = filename;
+
+	DBG(UTILS, ul_debug("utab: %s", filename));
+
+	rc = lstat(filename, &st);
+
+	if (rc == 0) {
+		/* file exists */
+		if (S_ISREG(st.st_mode)) {
+			if (writable)
+				*writable = !try_write(filename, NULL);
+			return 1;
+		}
+		goto done;	/* it's not a regular file */
+	}
+
+	if (writable) {
+		char *dirname = strdup(filename);
+
+		if (!dirname)
+			goto done;
+
+		stripoff_last_component(dirname);	/* remove filename */
+
+		rc = mkdir(dirname, S_IWUSR|
+				    S_IRUSR|S_IRGRP|S_IROTH|
+				    S_IXUSR|S_IXGRP|S_IXOTH);
+		if (rc && errno != EEXIST) {
+			free(dirname);
+			goto done;			/* probably EACCES */
+		}
+
+		*writable = !try_write(filename, dirname);
+		free(dirname);
+		if (*writable)
+			return 1;
+	}
+done:
+	DBG(UTILS, ul_debug("%s: irregular/non-writable file", filename));
+	return 0;
+}
+
+/**
+ * mnt_get_swaps_path:
+ *
+ * Returns: path to /proc/swaps or $LIBMOUNT_SWAPS.
+ */
+const char *mnt_get_swaps_path(void)
+{
+	const char *p = safe_getenv("LIBMOUNT_SWAPS");
+	return p ? : _PATH_PROC_SWAPS;
+}
+
+/**
+ * mnt_get_fstab_path:
+ *
+ * Returns: path to /etc/fstab or $LIBMOUNT_FSTAB.
+ */
+const char *mnt_get_fstab_path(void)
+{
+	const char *p = safe_getenv("LIBMOUNT_FSTAB");
+	return p ? : _PATH_MNTTAB;
+}
+
+/**
+ * mnt_get_mtab_path:
+ *
+ * This function returns the *default* location of the mtab file. The result does
+ * not have to be writable. See also mnt_has_regular_mtab().
+ *
+ * Returns: path to /etc/mtab or $LIBMOUNT_MTAB.
+ */
+const char *mnt_get_mtab_path(void)
+{
+	const char *p = safe_getenv("LIBMOUNT_MTAB");
+	return p ? : _PATH_MOUNTED;
+}
+
+/*
+ * Don't export this to libmount API -- utab is private library stuff.
+ *
+ * Returns: path to /run/mount/utab (or /dev/.mount/utab) or $LIBMOUNT_UTAB.
+ */
+const char *mnt_get_utab_path(void)
+{
+	struct stat st;
+	const char *p = safe_getenv("LIBMOUNT_UTAB");
+
+	if (p)
+		return p;
+
+	if (stat(MNT_RUNTIME_TOPDIR, &st) == 0)
+		return MNT_PATH_UTAB;
+
+	return MNT_PATH_UTAB_OLD;
+}
+
+
+/* returns file descriptor or -errno, @name returns a unique filename
+ */
+int mnt_open_uniq_filename(const char *filename, char **name)
+{
+	int rc, fd;
+	char *n;
+	mode_t oldmode;
+
+	if (!filename)
+		return -EINVAL;
+	if (name)
+		*name = NULL;
+
+	rc = asprintf(&n, "%s.XXXXXX", filename);
+	if (rc <= 0)
+		return -errno;
+
+	/* This is for very old glibc and for compatibility with Posix, which says
+	 * nothing about mkstemp() mode. All sane glibc use secure mode (0600).
+	 */
+	oldmode = umask(S_IRGRP|S_IWGRP|S_IXGRP|
+			S_IROTH|S_IWOTH|S_IXOTH);
+	fd = mkostemp(n, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC);
+	if (fd < 0)
+		fd = -errno;
+	umask(oldmode);
+
+	if (fd >= 0 && name)
+		*name = n;
+	else
+		free(n);
+
+	return fd;
+}
+
+/**
+ * mnt_get_mountpoint:
+ * @path: pathname
+ *
+ * This function finds the mountpoint that a given path resides in. @path
+ * should be canonicalized. The returned pointer should be freed by the caller.
+ *
+ * WARNING: the function compares st_dev of the @path elements. This traditional
+ * way may be insufficient on filesystems like Linux "overlay". See also
+ * mnt_table_find_target().
+ *
+ * Returns: allocated string with the target of the mounted device or NULL on error
+ */
+char *mnt_get_mountpoint(const char *path)
+{
+	char *mnt;
+	struct stat st;
+	dev_t dir, base;
+
+	if (!path)
+		return NULL;
+
+	mnt = strdup(path);
+	if (!mnt)
+		return NULL;
+	if (*mnt == '/' && *(mnt + 1) == '\0')
+		goto done;
+
+	if (mnt_stat_mountpoint(mnt, &st))
+		goto err;
+	base = st.st_dev;
+
+	do {
+		char *p = stripoff_last_component(mnt);
+
+		if (!p)
+			break;
+		if (mnt_stat_mountpoint(*mnt ? mnt : "/", &st))
+			goto err;
+		dir = st.st_dev;
+		if (dir != base) {
+			if (p > mnt)
+				*(p - 1) = '/';
+			goto done;
+		}
+		base = dir;
+	} while (mnt && *(mnt + 1) != '\0');
+
+	memcpy(mnt, "/", 2);
+done:
+	DBG(UTILS, ul_debug("%s mountpoint is %s", path, mnt));
+	return mnt;
+err:
+	free(mnt);
+	return NULL;
+}
+
+/*
+ * Search for @name kernel command parameter.
+ *
+ * Returns newly allocated string with a parameter argument if the @name is
+ * specified as "name=" or returns pointer to @name or returns NULL if not
+ * found.  If it is specified more than once, we grab the last copy.
+ *
+ * For example cmdline: "aaa bbb=BBB ccc"
+ *
+ *	@name is "aaa"	--returns--> "aaa" (pointer to @name)
+ *	@name is "bbb=" --returns--> "BBB" (allocated)
+ *	@name is "foo"  --returns--> NULL
+ *
+ * Note: It is not really feasible to parse the command line exactly the same
+ * as the kernel does since we don't know which options are valid.  We can use
+ * the -- marker though and not walk past that.
+ */
+char *mnt_get_kernel_cmdline_option(const char *name)
+{
+	FILE *f;
+	size_t len;
+	int val = 0;
+	char *p, *res = NULL, *mem = NULL;
+	char buf[BUFSIZ];	/* see kernel include/asm-generic/setup.h: COMMAND_LINE_SIZE */
+	const char *path = _PATH_PROC_CMDLINE;
+
+	if (!name || !name[0])
+		return NULL;
+
+#ifdef TEST_PROGRAM
+	path = getenv("LIBMOUNT_KERNEL_CMDLINE");
+	if (!path)
+		path = _PATH_PROC_CMDLINE;
+#endif
+	f = fopen(path, "r" UL_CLOEXECSTR);
+	if (!f)
+		return NULL;
+
+	p = fgets(buf, sizeof(buf), f);
+	fclose(f);
+
+	if (!p || !*p || *p == '\n')
+		return NULL;
+
+	p = strstr(p, " -- ");
+	if (p) {
+		/* no more kernel args after this */
+		*p = '\0';
+	} else {
+		len = strlen(buf);
+		buf[len - 1] = '\0';	/* remove last '\n' */
+	}
+
+	len = strlen(name);
+	if (name[len - 1] == '=')
+		val = 1;
+
+	for (p = buf; p && *p; p++) {
+		if (!(p = strstr(p, name)))
+			break;			/* not found the option */
+		if (p != buf && !isblank(*(p - 1)))
+			continue;		/* no space before the option */
+		if (!val && *(p + len) != '\0' && !isblank(*(p + len)))
+			continue;		/* no space after the option */
+		if (val) {
+			char *v = p + len;
+			int end;
+
+			while (*p && !isblank(*p))	/* jump to the end of the argument */
+				p++;
+			end = (*p == '\0');
+			*p = '\0';
+			free(mem);
+			res = mem = strdup(v);
+			if (end)
+				break;
+		} else
+			res = (char *) name;	/* option without '=' */
+		/* don't break -- keep scanning for more options */
+	}
+
+	return res;
+}
+
+/**
+ * mnt_guess_system_root:
+ * @devno: device number or zero
+ * @cache: paths cache or NULL
+ * @path: returns allocated path
+ *
+ * Converts @devno to the real device name if devno major number is greater
+ * than zero, otherwise use root= kernel cmdline option to get device name.
+ *
+ * The function uses /sys to convert devno to device name.
+ *
+ * Returns: 0 = success, 1 = not found, <0 = error
+ *
+ * Since: 2.34
+ */
+int mnt_guess_system_root(dev_t devno, struct libmnt_cache *cache, char **path)
+{
+	char buf[PATH_MAX];
+	char *dev = NULL, *spec = NULL;
+	unsigned int x, y;
+	int allocated = 0;
+
+	assert(path);
+
+	DBG(UTILS, ul_debug("guessing system root [devno %u:%u]", major(devno), minor(devno)));
+
+	/* The pseudo-fs, net-fs or btrfs devno is useless, otherwise it
+	 * usually matches with the source device, let's try to use it.
+	 */
+	if (major(devno) > 0) {
+		dev = sysfs_devno_to_devpath(devno, buf, sizeof(buf));
+		if (dev) {
+			DBG(UTILS, ul_debug("  devno converted to %s", dev));
+			goto done;
+		}
+	}
+
+	/* Let's try to use root= kernel command line option
+	 */
+	spec = mnt_get_kernel_cmdline_option("root=");
+	if (!spec)
+		goto done;
+
+	/* maj:min notation */
+	if (sscanf(spec, "%u:%u", &x, &y) == 2) {
+		dev = sysfs_devno_to_devpath(makedev(x, y), buf, sizeof(buf));
+		if (dev) {
+			DBG(UTILS, ul_debug("  root=%s converted to %s", spec, dev));
+			goto done;
+		}
+
+	/* hexhex notation */
+	} else if (isxdigit_string(spec)) {
+		char *end = NULL;
+		uint32_t n;
+
+		errno = 0;
+		n = strtoul(spec, &end, 16);
+
+		if (errno || spec == end || (end && *end))
+			DBG(UTILS, ul_debug("  failed to parse root='%s'", spec));
+		else {
+			/* kernel new_decode_dev() */
+			x = (n & 0xfff00) >> 8;
+			y = (n & 0xff) | ((n >> 12) & 0xfff00);
+			dev = sysfs_devno_to_devpath(makedev(x, y), buf, sizeof(buf));
+			if (dev) {
+				DBG(UTILS, ul_debug("  root=%s converted to %s", spec, dev));
+				goto done;
+			}
+		}
+
+	/* devname or PARTUUID= etc. */
+	} else {
+		DBG(UTILS, ul_debug("  converting root='%s'", spec));
+
+		dev = mnt_resolve_spec(spec, cache);
+		if (dev && !cache)
+			allocated = 1;
+	}
+done:
+	free(spec);
+	if (dev) {
+		*path = allocated ? dev : strdup(dev);
+		if (!*path)
+			return -ENOMEM;
+		return 0;
+	}
+
+	return 1;
+}
+
+#if defined(HAVE_FMEMOPEN) || defined(TEST_PROGRAM)
+
+/*
+ * This function tries to minimize possible races when we read
+ * /proc/#/{mountinfo,mount} files.
+ *
+ * The idea is to minimize number of read()s and check by poll() that during
+ * the read the mount table has not been modified. If yes, than re-read it
+ * (with some limitations to avoid never ending loop).
+ *
+ * Returns: <0 error, 0 success, 1 too many attempts
+ */
+static int read_procfs_file(int fd, char **buf, size_t *bufsiz)
+{
+	size_t bufmax = 0;
+	int rc = 0, tries = 0, ninters = 0;
+	char *bufptr = NULL;
+
+	assert(buf);
+	assert(bufsiz);
+
+	*bufsiz = 0;
+	*buf = NULL;
+
+	do {
+		ssize_t ret;
+
+		if (!bufptr || bufmax == *bufsiz) {
+			char *tmp;
+
+			bufmax = bufmax ? bufmax * 2 : (16 * 1024);
+			tmp = realloc(*buf, bufmax);
+			if (!tmp)
+				break;
+			*buf = tmp;
+			bufptr = tmp + *bufsiz;
+		}
+
+		errno = 0;
+		ret = read(fd, bufptr, bufmax - *bufsiz);
+
+		if (ret < 0) {
+			/* error */
+			if ((errno == EAGAIN || errno == EINTR) && (ninters++ < 5)) {
+				xusleep(200000);
+				continue;
+			}
+			break;
+
+		} if (ret > 0) {
+			/* success -- verify no event during read */
+			struct pollfd fds[] = {
+				{ .fd = fd, .events = POLLPRI }
+			};
+
+			rc = poll(fds, 1, 0);
+			if (rc < 0)
+				break;		/* poll() error */
+			if (rc > 0) {
+				/* event -- read all again */
+				if (lseek(fd, 0, SEEK_SET) != 0)
+					break;
+				*bufsiz = 0;
+				bufptr = *buf;
+				tries++;
+
+				if (tries > 10)
+					/* busy system? -- wait */
+					xusleep(10000);
+				continue;
+			}
+
+			/* successful read() without active poll() */
+			(*bufsiz) += (size_t) ret;
+			bufptr += ret;
+			tries = ninters = 0;
+		} else {
+			/* end-of-file */
+			goto success;
+		}
+	} while (tries <= 100);
+
+	rc = errno ? -errno : 1;
+	free(*buf);
+	return rc;
+
+success:
+	return 0;
+}
+
+/*
+ * Create FILE stream for data from read_procfs_file()
+ */
+FILE *mnt_get_procfs_memstream(int fd, char **membuf)
+{
+	size_t sz = 0;
+	off_t cur;
+
+	*membuf = NULL;
+
+	/* in case of error, rewind to the original position */
+	cur = lseek(fd, 0, SEEK_CUR);
+
+	if (read_procfs_file(fd, membuf, &sz) == 0 && sz > 0) {
+		FILE *memf = fmemopen(*membuf, sz, "r");
+		if (memf)
+			return memf;	/* success */
+
+		free(*membuf);
+		*membuf = NULL;
+	}
+
+	/* error */
+	if (cur != (off_t) -1)
+		lseek(fd, cur, SEEK_SET);
+	return NULL;
+}
+#else
+FILE *mnt_get_procfs_memstream(int fd __attribute((__unused__)),
+		               char **membuf __attribute((__unused__)))
+{
+	return NULL;
+}
+#endif /* HAVE_FMEMOPEN */
+
+
+#ifdef TEST_PROGRAM
+static int test_proc_read(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *buf = NULL;
+	char *filename = argv[1];
+	size_t bufsiz = 0;
+	int rc = 0, fd = open(filename, O_RDONLY);
+
+	if (fd <= 0) {
+		warn("%s: cannot open", filename);
+		return -errno;
+	}
+
+	rc = read_procfs_file(fd, &buf, &bufsiz);
+	close(fd);
+
+	switch (rc) {
+	case 0:
+		fwrite(buf, 1, bufsiz, stdout);
+		free(buf);
+		break;
+	case 1:
+		warnx("too many attempts");
+		break;
+	default:
+		warn("%s: cannot read", filename);
+		break;
+	}
+
+	return rc;
+}
+
+static int test_match_fstype(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *type = argv[1];
+	char *pattern = argv[2];
+
+	printf("%s\n", mnt_match_fstype(type, pattern) ? "MATCH" : "NOT-MATCH");
+	return 0;
+}
+
+static int test_match_options(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr = argv[1];
+	char *pattern = argv[2];
+
+	printf("%s\n", mnt_match_options(optstr, pattern) ? "MATCH" : "NOT-MATCH");
+	return 0;
+}
+
+static int test_startswith(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr = argv[1];
+	char *pattern = argv[2];
+
+	printf("%s\n", startswith(optstr, pattern) ? "YES" : "NOT");
+	return 0;
+}
+
+static int test_endswith(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *optstr = argv[1];
+	char *pattern = argv[2];
+
+	printf("%s\n", endswith(optstr, pattern) ? "YES" : "NOT");
+	return 0;
+}
+
+static int test_appendstr(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *str = strdup(argv[1]);
+	const char *ap = argv[2];
+
+	append_string(&str, ap);
+	printf("new string: '%s'\n", str);
+
+	free(str);
+	return 0;
+}
+
+static int test_mountpoint(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *path = canonicalize_path(argv[1]),
+	     *mnt = path ? mnt_get_mountpoint(path) :  NULL;
+
+	printf("%s: %s\n", argv[1], mnt ? : "unknown");
+	free(mnt);
+	free(path);
+	return 0;
+}
+
+static int test_filesystems(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char **filesystems = NULL;
+	int rc;
+
+	rc = mnt_get_filesystems(&filesystems, argc ? argv[1] : NULL);
+	if (!rc) {
+		char **p;
+		for (p = filesystems; *p; p++)
+			printf("%s\n", *p);
+		mnt_free_filesystems(filesystems);
+	}
+	return rc;
+}
+
+static int test_chdir(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int rc;
+	char *path = canonicalize_path(argv[1]),
+	     *last = NULL;
+
+	if (!path)
+		return -errno;
+
+	rc = mnt_chdir_to_parent(path, &last);
+	if (!rc) {
+		printf("path='%s', abs='%s', last='%s'\n",
+				argv[1], path, last);
+	}
+	free(path);
+	free(last);
+	return rc;
+}
+
+static int test_kernel_cmdline(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *name = argv[1];
+	char *res;
+
+	res = mnt_get_kernel_cmdline_option(name);
+	if (!res)
+		printf("'%s' not found\n", name);
+	else if (res == name)
+		printf("'%s' found\n", name);
+	else {
+		printf("'%s' found, argument: '%s'\n", name, res);
+		free(res);
+	}
+
+	return 0;
+}
+
+
+static int test_guess_root(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int rc;
+	char *real;
+	dev_t devno = 0;
+
+	if (argc) {
+		unsigned int x, y;
+
+		if (sscanf(argv[1], "%u:%u", &x, &y) != 2)
+			return -EINVAL;
+		devno = makedev(x, y);
+	}
+
+	rc = mnt_guess_system_root(devno, NULL, &real);
+	if (rc < 0)
+		return rc;
+	if (rc == 1)
+		fputs("not found\n", stdout);
+	else {
+		printf("%s\n", real);
+		free(real);
+	}
+	return 0;
+}
+
+static int test_mkdir(struct libmnt_test *ts, int argc, char *argv[])
+{
+	int rc;
+
+	rc = mkdir_p(argv[1], S_IRWXU |
+			 S_IRGRP | S_IXGRP |
+			 S_IROTH | S_IXOTH);
+	if (rc)
+		printf("mkdir %s failed\n", argv[1]);
+	return rc;
+}
+
+static int test_statfs_type(struct libmnt_test *ts, int argc, char *argv[])
+{
+	struct statfs vfs;
+	int rc;
+
+	rc = statfs(argv[1], &vfs);
+	if (rc)
+		printf("%s: statfs failed: %m\n", argv[1]);
+	else
+		printf("%-30s: statfs type: %-12s [0x%lx]\n", argv[1],
+				mnt_statfs_get_fstype(&vfs),
+				(long) vfs.f_type);
+	return rc;
+}
+
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test tss[] = {
+	{ "--match-fstype",  test_match_fstype,    "<type> <pattern>     FS types matching" },
+	{ "--match-options", test_match_options,   "<options> <pattern>  options matching" },
+	{ "--filesystems",   test_filesystems,	   "[<pattern>] list /{etc,proc}/filesystems" },
+	{ "--starts-with",   test_startswith,      "<string> <prefix>" },
+	{ "--ends-with",     test_endswith,        "<string> <prefix>" },
+	{ "--append-string", test_appendstr,       "<string> <appendix>" },
+	{ "--mountpoint",    test_mountpoint,      "<path>" },
+	{ "--cd-parent",     test_chdir,           "<path>" },
+	{ "--kernel-cmdline",test_kernel_cmdline,  "<option> | <option>=" },
+	{ "--guess-root",    test_guess_root,      "[<maj:min>]" },
+	{ "--mkdir",         test_mkdir,           "<path>" },
+	{ "--statfs-type",   test_statfs_type,     "<path>" },
+	{ "--read-procfs",   test_proc_read,       "<path>" },
+
+	{ NULL }
+	};
+
+	return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
diff --git a/libmount/src/version.c b/libmount/src/version.c
new file mode 100644
index 0000000..b69b09a
--- /dev/null
+++ b/libmount/src/version.c
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
+ *
+ * libmount is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ * SECTION: version-utils
+ * @title: Version functions
+ * @short_description: functions to get the library version.
+ */
+
+#include <ctype.h>
+
+#include "mountP.h"
+
+static const char *lib_version = LIBMOUNT_VERSION;
+static const char *lib_features[] = {
+#ifdef HAVE_LIBSELINUX
+	"selinux",
+#endif
+#ifdef HAVE_SMACK
+	"smack",
+#endif
+#ifdef HAVE_BTRFS_SUPPORT
+	"btrfs",
+#endif
+#ifdef HAVE_CRYPTSETUP
+	"verity",
+#endif
+#ifdef USE_LIBMOUNT_SUPPORT_MTAB
+	"mtab",
+#endif
+#ifdef USE_LIBMOUNT_SUPPORT_NAMESPACES
+	"namespaces",
+#endif
+#if !defined(NDEBUG)
+	"assert",	/* libc assert.h stuff */
+#endif
+	"debug",	/* always enabled */
+	NULL
+};
+
+/**
+ * mnt_parse_version_string:
+ * @ver_string: version string (e.g "2.18.0")
+ *
+ * Returns: release version code.
+ */
+int mnt_parse_version_string(const char *ver_string)
+{
+	const char *cp;
+	int version = 0;
+
+	assert(ver_string);
+
+	for (cp = ver_string; *cp; cp++) {
+		if (*cp == '.')
+			continue;
+		if (!isdigit(*cp))
+			break;
+		version = (version * 10) + (*cp - '0');
+	}
+	return version;
+}
+
+/**
+ * mnt_get_library_version:
+ * @ver_string: return pointer to the static library version string if not NULL
+ *
+ * Returns: release version number.
+ */
+int mnt_get_library_version(const char **ver_string)
+{
+	if (ver_string)
+		*ver_string = lib_version;
+
+	return mnt_parse_version_string(lib_version);
+}
+
+/**
+ * mnt_get_library_features:
+ * @features: returns a pointer to the static array of strings, the array is
+ *            terminated by NULL.
+ *
+ * Returns: number of items in the features array not including the last NULL,
+ *          or less than zero in case of error
+ *
+ * Example:
+ * <informalexample>
+ *   <programlisting>
+ *	const char **features;
+ *
+ *	mnt_get_library_features(&features);
+ *	while (features && *features)
+ *		printf("%s\n", *features++);
+ *   </programlisting>
+ * </informalexample>
+ *
+ */
+int mnt_get_library_features(const char ***features)
+{
+	if (!features)
+		return -EINVAL;
+
+	*features = lib_features;
+	return ARRAY_SIZE(lib_features) - 1;
+}
+
+#ifdef TEST_PROGRAM
+static int test_version(struct libmnt_test *ts, int argc, char *argv[])
+{
+	const char *ver;
+	const char **features;
+
+	if (argc == 2)
+		printf("Your version: %d\n",
+				mnt_parse_version_string(argv[1]));
+
+	mnt_get_library_version(&ver);
+
+	printf("Library version: %s\n", ver);
+	printf("Library API version: " LIBMOUNT_VERSION "\n");
+	printf("Library features:");
+
+	mnt_get_library_features(&features);
+	while (features && *features)
+		printf(" %s", *features++);
+
+	printf("\n");
+
+	if (mnt_get_library_version(NULL) ==
+			mnt_parse_version_string(LIBMOUNT_VERSION))
+		return 0;
+
+	return -1;
+}
+
+int main(int argc, char *argv[])
+{
+	struct libmnt_test ts[] = {
+		{ "--print", test_version, "print versions" },
+		{ NULL }
+	};
+
+	return mnt_run_test(ts, argc, argv);
+}
+#endif