Adding upstream version 2.36.1.upstream/2.36.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1343 insertions, 0 deletions

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);
+}