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, mnt_debug_h(upd, "%s: updating", upd->filename));
fd = mnt_open_uniq_filename(upd->filename, &uq);
if (fd < 0)
return fd; /* error */
f = fdopen(fd, "w");
if (f) {
struct stat st;
struct libmnt_iter itr;
struct libmnt_fs *fs;
int fd;
mnt_reset_iter(&itr, MNT_ITER_FORWARD);
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, mnt_debug_h(upd,
"%s: write entry failed: %m", uq));
goto leave;
}
}
if (fflush(f) != 0) {
rc = -errno;
DBG(UPDATE, mnt_debug_h(upd, "%s: fflush failed: %m", uq));
goto leave;
}
fd = fileno(f);
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);
rc = rename(uq, upd->filename) ? -errno : 0;
} else {
rc = -errno;
close(fd);
}
leave:
unlink(uq); /* be paranoid */
free(uq);
return rc;
}
/*
* The default is to use fstype from cxt->fs, this could be overwritten by
* @try_type argument.
*
* 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;
}
if (cxt->helper)
return exec_helper(cxt);
flags = cxt->mountflags;
src = mnt_fs_get_srcpath(cxt->fs);
target = mnt_fs_get_target(cxt->fs);
if (!src || !target)
return -EINVAL;
type = try_type ? : mnt_fs_get_fstype(cxt->fs);
if (!(flags & MS_MGC_MSK))
flags |= MS_MGC_VAL;
DBG(CXT, mnt_debug_h(cxt, "%smount(2) "
"[source=%s, target=%s, type=%s, "
" mountflags=0x%08lx, mountdata=%s]",
(cxt->flags & MNT_FL_FAKE) ? "(FAKE) " : "",
src, target, type,
flags, cxt->mountdata ? "yes" : "<none>"));
if (cxt->flags & MNT_FL_FAKE)
cxt->syscall_status = 0;
else {
if (mount(src, target, type, flags, cxt->mountdata)) {
cxt->syscall_status = -errno;
DBG(CXT, mnt_debug_h(cxt, "mount(2) failed [errno=%d %m]",
-cxt->syscall_status));
return -cxt->syscall_status;
}
DBG(CXT, mnt_debug_h(cxt, "mount(2) success"));
cxt->syscall_status = 0;
}
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;
}
/**
* 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 nlines = 0;
int rc = -1;
int flags = 0;
pid_t tid = -1;
assert(tb);
assert(f);
assert(filename);
DBG(TAB, mnt_debug_h(tb, "%s: start parsing [entries=%d, filter=%s]",
filename, mnt_table_get_nents(tb),
tb->fltrcb ? "yes" : "not"));
/* 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;
while (!feof(f)) {
struct libmnt_fs *fs = mnt_new_fs();
if (!fs)
goto err;
rc = mnt_table_parse_next(tb, f, fs, filename, &nlines);
if (!rc && tb->fltrcb && tb->fltrcb(fs, tb->fltrcb_data))
rc = 1; /* filtered out by callback... */
if (!rc) {
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);
}
mnt_unref_fs(fs);
if (rc) {
if (rc == 1)
continue; /* recoverable error */
if (feof(f))
break;
goto err; /* fatal error */
}
}
DBG(TAB, mnt_debug_h(tb, "%s: stop parsing (%d entries)",
filename, mnt_table_get_nents(tb)));
return 0;
err:
DBG(TAB, mnt_debug_h(tb, "%s: parse error (rc=%d)", filename, rc));
return rc;
}
/* Check, if there already exists a mounted loop device on the mountpoint node
* with the same parameters.
*/
static int 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;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!target || !backing_file || mnt_context_get_mtab(cxt, &tb))
return 0;
DBG(CXT, mnt_debug_h(cxt, "checking if %s mounted on %s",
backing_file, target));
cache = mnt_context_get_cache(cxt);
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
/* Search for mountpoint node in mtab, procceed if any of these has the
* loop option set or the device is a loop device
*/
while (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;
int res = 0;
if (!src || !mnt_fs_match_target(fs, target, cache))
continue;
if (strncmp(src, "/dev/loop", 9) == 0) {
res = loopdev_is_used((char *) src, backing_file,
offset, 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);
res = loopdev_is_used((char *) val, backing_file,
offset, LOOPDEV_FL_OFFSET);
free(val);
}
if (res) {
DBG(CXT, mnt_debug_h(cxt, "%s already mounted", backing_file));
return 1;
}
}
return 0;
}
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(CXT, mnt_debug_h(cxt, "loopdev specific options detected"));
return 1;
}
if (cxt->mountflags & (MS_BIND | MS_MOVE | MS_PROPAGATION))
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 empty loopdev where
* is no mountable filesystem...
*
* Note that there is not a restriction (on kernel side) that prevents 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(CXT, mnt_debug_h(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;
}
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;
assert(cxt);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!neg && pattern) {
/*
* try all types from the list
*/
char *p, *p0;
DBG(CXT, mnt_debug_h(cxt, "trying to mount by FS pattern list"));
p0 = p = strdup(pattern);
if (!p)
return -ENOMEM;
do {
char *end = strchr(p, ',');
if (end)
*end = '\0';
rc = do_mount(cxt, p);
p = end ? end + 1 : NULL;
} while (!mnt_context_get_status(cxt) && p);
free(p0);
if (mnt_context_get_status(cxt))
return rc;
}
/*
* try /etc/filesystems and /proc/filesystems
*/
DBG(CXT, mnt_debug_h(cxt, "trying to mount by filesystems lists"));
rc = mnt_get_filesystems(&filesystems, neg ? pattern : NULL);
if (rc)
return rc;
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)
break;
}
mnt_free_filesystems(filesystems);
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 nlines = 0;
int rc = -1;
int flags = 0;
pid_t tid = -1;
assert(tb);
assert(f);
assert(filename);
DBG(TAB, mnt_debug_h(tb, "%s: start parsing (%d entries)",
filename, mnt_table_get_nents(tb)));
/* 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;
while (!feof(f)) {
struct libmnt_fs *fs = mnt_new_fs();
if (!fs)
goto err;
rc = mnt_table_parse_next(tb, f, fs, filename, &nlines);
if (!rc) {
rc = mnt_table_add_fs(tb, fs);
fs->flags |= flags;
if (tb->fmt == MNT_FMT_MOUNTINFO && filename) {
if (tid == -1)
tid = path_to_tid(filename);
fs->tid = tid;
}
}
if (rc) {
mnt_free_fs(fs);
if (rc == 1)
continue; /* recoverable error */
if (feof(f))
break;
goto err; /* fatal error */
}
}
DBG(TAB, mnt_debug_h(tb, "%s: stop parsing (%d entries)",
filename, mnt_table_get_nents(tb)));
return 0;
err:
DBG(TAB, mnt_debug_h(tb, "%s: parse error (rc=%d)", filename, rc));
return rc;
}
/*
* This function uses @uf to found 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;
assert(tb);
assert(uf);
if (!tb || !uf)
return NULL;
DBG(TAB, mnt_debug_h(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 *s = mnt_fs_get_srcpath(fs),
*t = mnt_fs_get_target(fs),
*r = mnt_fs_get_root(fs);
if (fs->flags & MNT_FS_MERGED)
continue;
if (s && t && r && !strcmp(t, target) &&
!strcmp(s, src) && !strcmp(r, root))
break;
}
if (fs) {
DBG(TAB, mnt_debug_h(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, mnt_debug_h(tb, "found fs:"));
DBG(TAB, mnt_fs_print_debug(fs, stderr));
}
return fs;
}
/**
* 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;
assert(token);
assert(value);
DBG(CACHE, mnt_debug_h(cache, "resolving tag token=%s value=%s",
token, value));
if (!token || !value)
return NULL;
if (cache)
p = (char *) mnt_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 &&
mnt_cache_add_tag(cache, token, value, p, 0))
goto error;
}
return p;
error:
free(p);
return NULL;
}
/* note that the @native could be tha same pointer as @real */
static int mnt_cache_add_entry(struct libmnt_cache *cache, char *native,
char *real, int flag)
{
struct mnt_cache_entry *e;
assert(cache);
assert(real);
assert(native);
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->native = native;
e->real = real;
e->flag = flag;
cache->nents++;
DBG(CACHE, mnt_debug_h(cache, "add entry [%2zd] (%s): %s: %s",
cache->nents,
(flag & MNT_CACHE_ISPATH) ? "path" : "tag",
real, native));
return 0;
}
static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *lc)
{
struct libmnt_table *tb = NULL;
int rc = 0;
DBG(UPDATE, mnt_debug_h(upd, "%s: modify target", upd->filename));
if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
tb = __mnt_new_table_from_file(upd->filename,
upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB);
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_free_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, mnt_debug_h(upd, "%s: remove entry", upd->filename));
if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
tb = __mnt_new_table_from_file(upd->filename,
upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB);
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);
mnt_free_fs(rem);
}
}
if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
return rc;
}
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, mnt_debug_h(upd, "%s: add entry", upd->filename));
if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
tb = __mnt_new_table_from_file(upd->filename,
upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB);
if (tb) {
struct libmnt_fs *fs = mnt_copy_fs(NULL, upd->fs);
if (!fs)
rc = -ENOMEM;
else {
mnt_table_add_fs(tb, fs);
rc = update_table(upd, tb);
}
}
if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
return rc;
}
/* note that the @key could be tha 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, mnt_debug_h(cache, "add entry [%2zd] (%s): %s: %s",
cache->nents,
(flag & MNT_CACHE_ISPATH) ? "path" : "tag",
value, key));
return 0;
}
/**
* 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, mnt_debug_h(cache, "get %s FS type", devname));
if (cache)
return mnt_cache_find_tag_value(cache, devname, "TYPE");
if (cache_get_probe(NULL, devname, &pr))
return NULL;
blkid_probe_enable_superblocks(pr, 1);
blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_TYPE);
rc = blkid_do_safeprobe(pr);
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;
}
/**
* mnt_table_get_root_fs:
* @tb: mountinfo file (/proc/self/mountinfo)
* @root: returns pointer to the root filesystem (/)
*
* The function uses parent ID from mountinfo file to determine root filesystem
* (the filesystem with the smallest ID). The function is designed mostly for
* applications where is necessary to sort mountpoints by IDs to get the tree
* of the mountpoints (e.g. findmnt default output).
*
* If you're not sure than use
*
* mnt_table_find_target(tb, "/", MNT_ITER_BACKWARD);
*
* this is more robust and usable for arbitrary tab file (including fstab).
*
* Returns: 0 on success or less then zero 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;
assert(tb);
assert(root);
if (!tb || !root)
return -EINVAL;
DBG(TAB, mnt_debug_h(tb, "lookup root fs"));
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 (!id)
break; /* @tab is not mountinfo file? */
if (!*root || id < root_id) {
*root = fs;
root_id = id;
}
}
return root_id ? 0 : -EINVAL;
}
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, mnt_debug_h(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;
}
static int prepare_helper_from_options(struct libmnt_context *cxt,
const char *name)
{
char *suffix = NULL;
const char *opts;
size_t valsz;
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, mnt_debug_h(cxt, "umount: umount.%s %s requested", suffix, name));
return mnt_context_prepare_helper(cxt, "umount", suffix);
}
/**
* mnt_table_parse_mtab:
* @tb: table
* @filename: overwrites default (/etc/mtab or $LIBMOUNT_MTAB) or NULL
*
* This function parses /etc/mtab or /proc/self/mountinfo +
* /run/mount/utabs or /proc/mounts.
*
* 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)
{
int rc;
const char *utab = NULL;
struct libmnt_table *u_tb;
assert(tb);
if (mnt_has_regular_mtab(&filename, NULL)) {
DBG(TAB, mnt_debug_h(tb, "force %s usage", filename));
rc = mnt_table_parse_file(tb, filename);
if (!rc)
return 0;
filename = NULL; /* failed */
}
/*
* useless /etc/mtab
* -- read kernel information from /proc/self/mountinfo
*/
tb->fmt = MNT_FMT_MOUNTINFO;
rc = mnt_table_parse_file(tb, _PATH_PROC_MOUNTINFO);
if (rc) {
/* hmm, old kernel? ...try /proc/mounts */
tb->fmt = MNT_FMT_MTAB;
return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
}
if (mnt_table_get_nents(tb) == 0)
return 0; /* empty, ignore utab */
/*
* try to read the user specific information from /run/mount/utabs
*/
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);
if (mnt_table_parse_file(u_tb, utab) == 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);
}
mnt_unref_table(u_tb);
return 0;
}
/**
* 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, mnt_debug_h(cache, "alloc"));
return cache;
}
/**
* mnt_free_table:
* @tb: tab pointer
*
* Deallocates tab struct and all entries.
*/
void mnt_free_table(struct libmnt_table *tb)
{
if (!tb)
return;
mnt_reset_table(tb);
DBG(TAB, mnt_debug_h(tb, "free"));
free(tb);
}
/**
* 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;
assert(cxt);
assert(cxt->fs);
assert(cxt->helper_exec_status == 1);
assert(cxt->syscall_status == 1);
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;
cxt->action = MNT_ACT_MOUNT;
DBG(CXT, mnt_debug_h(cxt, "mount: preparing"));
/* TODO: fstab is unnecessary for MS_{MOVE,BIND,STARED,...} */
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_prepare_target(cxt);
if (!rc)
rc = mnt_context_guess_fstype(cxt);
if (!rc)
rc = mnt_context_prepare_helper(cxt, "mount", NULL);
if (rc) {
DBG(CXT, mnt_debug_h(cxt, "mount: preparing failed"));
return rc;
}
cxt->flags |= MNT_FL_PREPARED;
return rc;
}
/**
* 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;
assert(cxt);
assert(cxt->fs);
assert(cxt->helper_exec_status == 1);
assert(cxt->syscall_status == 1);
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;
free(cxt->helper); /* be paranoid */
cxt->helper = NULL;
cxt->action = MNT_ACT_UMOUNT;
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, mnt_debug_h(cxt, "umount: preparing failed"));
return rc;
}
cxt->flags |= MNT_FL_PREPARED;
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 than you have to call mnt_reset_context().
*
* If you want to call mount(2) for the same source and target with a diffrent
* 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!
*
* 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;
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, mnt_debug_h(cxt, "mount: do mount"));
if (!(cxt->flags & MNT_FL_MOUNTDATA))
cxt->mountdata = (char *) mnt_fs_get_fs_options(cxt->fs);
type = mnt_fs_get_fstype(cxt->fs);
if (type)
res = do_mount(cxt, NULL);
else
res = do_mount_by_pattern(cxt, cxt->fstype_pattern);
if (mnt_context_get_status(cxt)
&& !mnt_context_is_fake(cxt)
&& !cxt->helper) {
/*
* Mounted by mount(2), do some post-mount checks
*
* Kernel allows 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)
&& !mnt_is_readonly(mnt_context_get_target(cxt)))
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_PROPAGATION | MS_MOVE))
&& mnt_is_readonly(mnt_context_get_target(cxt)))
mnt_context_set_mflags(cxt,
cxt->mountflags | MS_RDONLY);
}
return res;
}
/*
* 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)
{
assert(tb);
DBG(TAB, mnt_debug_h(tb, "%s table parser filter", cb ? "set" : "unset"));
tb->fltrcb = cb;
tb->fltrcb_data = data;
return 0;
}
/**
* 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, mnt_debug_h(upd, "allocate"));
return upd;
}
/**
* 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 how was mounted (according to
* IDs in /proc/self/mountinfo).
*
* Returns: 0 on success, negative number in case of error or 1 at 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)
return -EINVAL;
DBG(TAB, mnt_debug_h(tb, "lookup next child of '%s'",
mnt_fs_get_target(parent)));
parent_id = mnt_fs_get_id(parent);
if (!parent_id)
return -EINVAL;
/* 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 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_id)
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_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
* the 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;
assert(upd);
if (!upd->filename || !upd)
return -EINVAL;
if (!upd->ready)
return 0;
DBG(UPDATE, mnt_debug_h(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, mnt_debug_h(upd, "%s: update tab: done [rc=%d]",
upd->filename, rc));
if (lc != lc0)
mnt_free_lock(lc);
return rc;
}
/**
* 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, mnt_debug_h(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, mnt_debug_h(cache, "liblkid 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;
}
/**
* 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, mnt_debug_h(tb, "alloc"));
INIT_LIST_HEAD(&tb->ents);
return tb;
}
