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Diffstat (limited to 'libmount/src/fs.c')
| -rw-r--r-- | libmount/src/fs.c | 1602 |
1 files changed, 1602 insertions, 0 deletions
diff --git a/libmount/src/fs.c b/libmount/src/fs.c new file mode 100644 index 0000000..9971d6a --- /dev/null +++ b/libmount/src/fs.c @@ -0,0 +1,1602 @@ +/* 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; +} + +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->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 (cpy_str_at_offset(n, fs, offsetof(struct libmnt_fs, source))) + goto err; + if (cpy_str_at_offset(n, fs, offsetof(struct libmnt_fs, target))) + goto err; + if (cpy_str_at_offset(n, fs, offsetof(struct libmnt_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 (cpy_str_at_offset(n, fs, offsetof(struct libmnt_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_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; +} |