static int is_mounted(struct libmnt_fs *fs)
{
int rc;
const char *src;
src = mnt_fs_get_source(fs);
if (!src)
return 0;
if (!mntcache)
mntcache = mnt_new_cache();
if (!mtab) {
mtab = mnt_new_table();
if (!mtab)
err(FSCK_EX_ERROR, ("failed to initialize libmount table"));
mnt_table_set_cache(mtab, mntcache);
mnt_table_parse_mtab(mtab, NULL);
}
rc = mnt_table_find_source(mtab, src, MNT_ITER_BACKWARD) ? 1 : 0;
if (verbose) {
if (rc)
printf(_("%s is mounted\n"), src);
else
printf(_("%s is not mounted\n"), src);
}
return rc;
}
static int fprintf_utab_fs(FILE *f, struct libmnt_fs *fs)
{
char *p;
int rc = 0;
assert(fs);
assert(f);
if (!fs || !f)
return -EINVAL;
p = mangle(mnt_fs_get_source(fs));
if (p) {
rc = fprintf(f, "SRC=%s ", p);
free(p);
}
if (rc >= 0) {
p = mangle(mnt_fs_get_target(fs));
if (p) {
rc = fprintf(f, "TARGET=%s ", p);
free(p);
}
}
if (rc >= 0) {
p = mangle(mnt_fs_get_root(fs));
if (p) {
rc = fprintf(f, "ROOT=%s ", p);
free(p);
}
}
if (rc >= 0) {
p = mangle(mnt_fs_get_bindsrc(fs));
if (p) {
rc = fprintf(f, "BINDSRC=%s ", p);
free(p);
}
}
if (rc >= 0) {
p = mangle(mnt_fs_get_attributes(fs));
if (p) {
rc = fprintf(f, "ATTRS=%s ", p);
free(p);
}
}
if (rc >= 0) {
p = mangle(mnt_fs_get_user_options(fs));
if (p) {
rc = fprintf(f, "OPTS=%s", p);
free(p);
}
}
if (rc >= 0)
rc = fprintf(f, "\n");
if (rc > 0)
rc = 0; /* success */
return rc;
}
/* 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;
}
/**
* mnt_table_add_fs:
* @tb: tab pointer
* @fs: new entry
*
* Adds a new entry to tab and increment @fs reference counter. Don't forget to
* use mnt_unref_fs() after mnt_table_add_fs() you want to keep the @fs
* referenced by the table only.
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_add_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
{
if (!tb || !fs)
return -EINVAL;
mnt_ref_fs(fs);
list_add_tail(&fs->ents, &tb->ents);
tb->nents++;
DBG(TAB, ul_debugobj(tb, "add entry: %s %s",
mnt_fs_get_source(fs), mnt_fs_get_target(fs)));
return 0;
}
static int swapoff_all(void)
{
int status = 0;
struct libmnt_table *tb;
struct libmnt_fs *fs;
struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_BACKWARD);
if (!itr)
err(EXIT_FAILURE, _("failed to initialize libmount iterator"));
/*
* In case /proc/swaps exists, unswap stuff listed there. We are quiet
* but report errors in status. Errors might mean that /proc/swaps
* exists as ordinary file, not in procfs. do_swapoff() exits
* immediately on EPERM.
*/
tb = get_swaps();
while (tb && mnt_table_find_next_fs(tb, itr, match_swap, NULL, &fs) == 0)
status |= do_swapoff(mnt_fs_get_source(fs), QUIET, CANONIC);
/*
* Unswap stuff mentioned in /etc/fstab. Probably it was unmounted
* already, so errors are not bad. Doing swapoff -a twice should not
* give error messages.
*/
tb = get_fstab();
mnt_reset_iter(itr, MNT_ITER_FORWARD);
while (tb && mnt_table_find_next_fs(tb, itr, match_swap, NULL, &fs) == 0) {
if (!is_active_swap(mnt_fs_get_source(fs)))
do_swapoff(mnt_fs_get_source(fs), QUIET, !CANONIC);
}
mnt_free_iter(itr);
return status;
}
/**
* mnt_table_add_fs:
* @tb: tab pointer
* @fs: new entry
*
* Adds a new entry to tab.
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_add_fs(struct libmnt_table *tb, struct libmnt_fs *fs)
{
assert(tb);
assert(fs);
if (!tb || !fs)
return -EINVAL;
list_add_tail(&fs->ents, &tb->ents);
DBG(TAB, mnt_debug_h(tb, "add entry: %s %s",
mnt_fs_get_source(fs), mnt_fs_get_target(fs)));
tb->nents++;
return 0;
}
static char *dir_to_device(const char *spec)
{
struct libmnt_table *tb = mnt_new_table_from_file("/proc/self/mountinfo");
struct libmnt_fs *fs;
char *res = NULL;
if (!tb)
return NULL;
fs = mnt_table_find_target(tb, spec, MNT_ITER_BACKWARD);
if (fs && mnt_fs_get_target(fs))
res = xstrdup(mnt_fs_get_source(fs));
mnt_free_table(tb);
return res;
}
/*
* This function works like mnt_resolve_tag(), but it's able to read UUiD/LABEL
* from regular swap files too (according to entries in /proc/swaps). Note that
* mnt_resolve_tag() and mnt_resolve_spec() works with system visible block
* devices only.
*/
static char *swapoff_resolve_tag(const char *name, const char *value,
struct libmnt_cache *cache)
{
char *path;
struct libmnt_table *tb;
struct libmnt_iter *itr;
struct libmnt_fs *fs;
/* this is usual case for block devices (and it's really fast as it uses
* udev /dev/disk/by-* symlinks by default */
path = mnt_resolve_tag(name, value, cache);
if (path)
return path;
/* try regular files from /proc/swaps */
tb = get_swaps();
if (!tb)
return NULL;
itr = mnt_new_iter(MNT_ITER_BACKWARD);
if (!itr)
err(EXIT_FAILURE, _("failed to initialize libmount iterator"));
while (tb && mnt_table_next_fs(tb, itr, &fs) == 0) {
blkid_probe pr = NULL;
const char *src = mnt_fs_get_source(fs);
const char *type = mnt_fs_get_swaptype(fs);
const char *data = NULL;
if (!src || !type || strcmp(type, "file") != 0)
continue;
pr = get_swap_prober(src);
if (!pr)
continue;
blkid_probe_lookup_value(pr, name, &data, NULL);
if (data && strcmp(data, value) == 0)
path = xstrdup(src);
blkid_free_probe(pr);
if (path)
break;
}
mnt_free_iter(itr);
return path;
}
int main (int argc, char *argv[])
{
struct libmnt_fs *fs;
struct libmnt_table *tab;
mnt_init_debug(0xffff);
tab = mnt_new_table_from_file("/proc/self/mounts");
fs = mnt_table_find_target(tab, argv[2], MNT_ITER_BACKWARD);
char *source = mnt_fs_get_source(fs);
if (strcmp(source, argv[1]) == 0)
printf("is mounted\n");
else
printf("could not find fs in tab\n");
mnt_free_table(tab);
#if 0
int rc;
struct libmnt_fs *fs;
struct libmnt_context *cxt = mnt_new_context();
mnt_init_debug(0xffff);
mnt_context_set_source(cxt, argv[1]);
mnt_context_set_target(cxt, argv[2]);
fs = mnt_context_get_fs(cxt);
if (fs != NULL)
{
if (mnt_context_is_fs_mounted(cxt, fs, &rc))
rc = 1;
else
printf("can't find fs in mtab\n");
}
else
printf("Can't get fs from mnt context\n");
mnt_free_context(cxt);
#endif
return 0;
}
/*
* fs from fstab might contains real device name as well as symlink,
* LABEL or UUID, this function returns canonicalized result.
*/
static const char *fs_get_device(struct libmnt_fs *fs)
{
struct fsck_fs_data *data = mnt_fs_get_userdata(fs);
if (!data || !data->eval_device) {
const char *spec = mnt_fs_get_source(fs);
if (!data)
data = fs_create_data(fs);
data->eval_device = 1;
data->device = mnt_resolve_spec(spec, mnt_table_get_cache(fstab));
if (!data->device)
data->device = xstrdup(spec);
}
return data->device;
}
static int try_mount(struct libmnt_context *cxt, int bg)
{
struct libmnt_fs *fs;
const char *p;
char *src = NULL, *tgt = NULL, *type = NULL, *opts = NULL;
unsigned long flags = 0;
int fake, ret = 0;
fs = mnt_context_get_fs(cxt);
/* libmount returns read-only pointers (const char)
* so, reallocate for nfsmount() functions.
*/
if ((p = mnt_fs_get_source(fs))) /* spec */
src = strdup(p);
if ((p = mnt_fs_get_target(fs))) /* mountpoint */
tgt = strdup(p);
if ((p = mnt_fs_get_fstype(fs))) /* FS type */
type = strdup(p);
if ((p = mnt_fs_get_fs_options(fs))) /* mount options */
opts = strdup(p);
mnt_context_get_mflags(cxt, &flags); /* mount(2) flags */
fake = mnt_context_is_fake(cxt);
if (string)
ret = nfsmount_string(src, tgt, type, flags, &opts, fake, bg);
else if (strcmp(type, "nfs4") == 0)
ret = nfs4mount(src, tgt, flags, &opts, fake, bg);
else
ret = nfsmount(src, tgt, flags, &opts, fake, bg);
/* Store mount options if not called with mount --no-mtab */
if (!ret && !mnt_context_is_nomtab(cxt))
store_mount_options(fs, opts);
free(src);
free(tgt);
free(type);
free(opts);
return ret;
}
/**
* 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;
}
/*
* See if device has been mounted by looking in mount table. If so, set
* device name and mount point name, and return 1, otherwise return 0.
*/
static int device_get_mountpoint(char **devname, char **mnt)
{
struct libmnt_fs *fs;
int rc;
*mnt = NULL;
if (!mtab) {
mtab = mnt_new_table();
if (!mtab)
err(EXIT_FAILURE, _("failed to initialize libmount table"));
cache = mnt_new_cache();
mnt_table_set_cache(mtab, cache);
if (p_option)
rc = mnt_table_parse_file(mtab, _PATH_PROC_MOUNTINFO);
else
rc = mnt_table_parse_mtab(mtab, NULL);
if (rc)
err(EXIT_FAILURE, _("failed to parse mount table"));
}
fs = mnt_table_find_source(mtab, *devname, MNT_ITER_BACKWARD);
if (!fs) {
/* maybe 'devname' is mountpoint rather than a real device */
fs = mnt_table_find_target(mtab, *devname, MNT_ITER_BACKWARD);
if (fs) {
free(*devname);
*devname = xstrdup(mnt_fs_get_source(fs));
}
}
if (fs) {
*mnt = xstrdup(mnt_fs_get_target(fs));
/* We'll call umount(), so remove the filesystem from the table
* to avoid duplicate results in the next device_get_mountpoint()
* call */
mnt_free_fs(fs);
}
return *mnt ? 0 : -1;
}
/*
* See if device has been mounted by looking in mount table. If so, set
* device name and mount point name, and return 1, otherwise return 0.
*/
static int device_get_mountpoint(char **devname, char **mnt)
{
struct libmnt_fs *fs;
int rc;
*mnt = NULL;
if (!mtab) {
struct libmnt_cache *cache;
mtab = mnt_new_table();
if (!mtab)
err(EXIT_FAILURE, _("failed to initialize libmount table"));
cache = mnt_new_cache();
mnt_table_set_cache(mtab, cache);
mnt_unref_cache(cache);
if (p_option)
rc = mnt_table_parse_file(mtab, _PATH_PROC_MOUNTINFO);
else
rc = mnt_table_parse_mtab(mtab, NULL);
if (rc)
err(EXIT_FAILURE, _("failed to parse mount table"));
}
fs = mnt_table_find_source(mtab, *devname, MNT_ITER_BACKWARD);
if (!fs) {
/* maybe 'devname' is mountpoint rather than a real device */
fs = mnt_table_find_target(mtab, *devname, MNT_ITER_BACKWARD);
if (fs) {
free(*devname);
*devname = xstrdup(mnt_fs_get_source(fs));
}
}
if (fs)
*mnt = xstrdup(mnt_fs_get_target(fs));
return *mnt ? 0 : -1;
}
/* mtab and fstab update -- returns zero on success
*/
static int fprintf_mtab_fs(FILE *f, struct libmnt_fs *fs)
{
const char *o, *src, *fstype;
char *m1, *m2, *m3, *m4;
int rc;
assert(fs);
assert(f);
src = mnt_fs_get_source(fs);
fstype = mnt_fs_get_fstype(fs);
o = mnt_fs_get_options(fs);
m1 = src ? mangle(src) : "none";
m2 = mangle(mnt_fs_get_target(fs));
m3 = fstype ? mangle(fstype) : "none";
m4 = o ? mangle(o) : "rw";
if (m1 && m2 && m3 && m4) {
rc = fprintf(f, "%s %s %s %s %d %d\n",
m1, m2, m3, m4,
mnt_fs_get_freq(fs),
mnt_fs_get_passno(fs));
if (rc > 0)
rc = 0;
} else
rc = -ENOMEM;
if (src)
free(m1);
free(m2);
if (fstype)
free(m3);
if (o)
free(m4);
return rc;
}
static int lookup_umount_fs(struct libmnt_context *cxt)
{
int rc, loopdev = 0;
const char *tgt;
struct libmnt_table *mtab = NULL;
struct libmnt_fs *fs;
struct libmnt_cache *cache = NULL;
char *cn_tgt = NULL;
assert(cxt);
assert(cxt->fs);
DBG(CXT, mnt_debug_h(cxt, "umount: lookup FS"));
tgt = mnt_fs_get_target(cxt->fs);
if (!tgt) {
DBG(CXT, mnt_debug_h(cxt, "umount: undefined target"));
return -EINVAL;
}
/*
* The mtab file maybe huge and on systems with utab we have to merge
* userspace mount options into /proc/self/mountinfo. This all is
* expensive. The mtab filter allows to filter out entries, then
* mtab and utab are very tiny files.
*
* *but*... the filter uses mnt_fs_streq_{target,srcpath} functions
* where LABEL, UUID or symlinks are to canonicalized. It means that
* it's usable only for canonicalized stuff (e.g. kernel mountinfo).
*/
if (!cxt->mtab_writable && *tgt == '/' &&
!mnt_context_is_force(cxt) && !mnt_context_is_lazy(cxt)) {
struct stat st;
if (stat(tgt, &st) == 0 && S_ISDIR(st.st_mode)) {
/* we'll canonicalized /proc/self/mountinfo */
cache = mnt_context_get_cache(cxt);
cn_tgt = mnt_resolve_path(tgt, cache);
if (cn_tgt)
mnt_context_set_tabfilter(cxt, mtab_filter, cn_tgt);
}
}
rc = mnt_context_get_mtab(cxt, &mtab);
if (cn_tgt) {
mnt_context_set_tabfilter(cxt, NULL, NULL);
if (!cache)
free(cn_tgt);
}
if (rc) {
DBG(CXT, mnt_debug_h(cxt, "umount: failed to read mtab"));
return rc;
}
try_loopdev:
fs = mnt_table_find_target(mtab, tgt, MNT_ITER_BACKWARD);
if (!fs && mnt_context_is_swapmatch(cxt)) {
/*
* Maybe the option is source rather than target (sometimes
* people use e.g. "umount /dev/sda1")
*/
fs = mnt_table_find_source(mtab, tgt, MNT_ITER_BACKWARD);
if (fs) {
struct libmnt_fs *fs1 = mnt_table_find_target(mtab,
mnt_fs_get_target(fs),
MNT_ITER_BACKWARD);
if (!fs1) {
DBG(CXT, mnt_debug_h(cxt, "mtab is broken?!?!"));
return -EINVAL;
}
if (fs != fs1) {
/* Something was stacked over `file' on the
* same mount point. */
DBG(CXT, mnt_debug_h(cxt,
"umount: %s: %s is mounted "
"over it on the same point",
tgt, mnt_fs_get_source(fs1)));
return -EINVAL;
}
}
}
if (!fs && !loopdev && mnt_context_is_swapmatch(cxt)) {
/*
* Maybe the option is /path/file.img, try to convert to /dev/loopN
*/
struct stat st;
if (stat(tgt, &st) == 0 && S_ISREG(st.st_mode)) {
char *dev = NULL;
int count = loopdev_count_by_backing_file(tgt, &dev);
if (count == 1) {
DBG(CXT, mnt_debug_h(cxt,
"umount: %s --> %s (retry)", tgt, dev));
mnt_fs_set_source(cxt->fs, tgt);
mnt_fs_set_target(cxt->fs, dev);
free(dev);
tgt = mnt_fs_get_target(cxt->fs);
loopdev = 1; /* to avoid endless loop */
goto try_loopdev;
} else if (count > 1)
DBG(CXT, mnt_debug_h(cxt,
"umount: warning: %s is associated "
"with more than one loopdev", tgt));
}
}
if (!fs) {
DBG(CXT, mnt_debug_h(cxt, "umount: cannot find %s in mtab", tgt));
return 0;
}
if (fs != cxt->fs) {
/* copy from mtab to our FS description
*/
mnt_fs_set_source(cxt->fs, NULL);
mnt_fs_set_target(cxt->fs, NULL);
if (!mnt_copy_fs(cxt->fs, fs)) {
DBG(CXT, mnt_debug_h(cxt, "umount: failed to copy FS"));
return -errno;
}
DBG(CXT, mnt_debug_h(cxt, "umount: mtab applied"));
}
cxt->flags |= MNT_FL_TAB_APPLIED;
return rc;
}
/*
* Note that cxt->fs contains relevant mtab entry!
*/
static int evaluate_permissions(struct libmnt_context *cxt)
{
struct libmnt_table *fstab;
unsigned long u_flags = 0;
const char *tgt, *src, *optstr;
int rc, ok = 0;
struct libmnt_fs *fs;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!cxt || !cxt->fs)
return -EINVAL;
if (!mnt_context_is_restricted(cxt))
return 0; /* superuser mount */
DBG(CXT, mnt_debug_h(cxt, "umount: evaluating permissions"));
if (!(cxt->flags & MNT_FL_TAB_APPLIED)) {
DBG(CXT, mnt_debug_h(cxt,
"cannot find %s in mtab and you are not root",
mnt_fs_get_target(cxt->fs)));
goto eperm;
}
if (cxt->user_mountflags & MNT_MS_UHELPER) {
/* on uhelper= mount option based helper */
rc = prepare_helper_from_options(cxt, "uhelper");
if (rc)
return rc;
if (cxt->helper)
return 0; /* we'll call /sbin/umount.<uhelper> */
}
/*
* User mounts has to be in /etc/fstab
*/
rc = mnt_context_get_fstab(cxt, &fstab);
if (rc)
return rc;
tgt = mnt_fs_get_target(cxt->fs);
src = mnt_fs_get_source(cxt->fs);
if (mnt_fs_get_bindsrc(cxt->fs)) {
src = mnt_fs_get_bindsrc(cxt->fs);
DBG(CXT, mnt_debug_h(cxt,
"umount: using bind source: %s", src));
}
/* If fstab contains the two lines
* /dev/sda1 /mnt/zip auto user,noauto 0 0
* /dev/sda4 /mnt/zip auto user,noauto 0 0
* then "mount /dev/sda4" followed by "umount /mnt/zip" used to fail.
* So, we must not look for file, but for the pair (dev,file) in fstab.
*/
fs = mnt_table_find_pair(fstab, src, tgt, MNT_ITER_FORWARD);
if (!fs) {
/*
* It's possible that there is /path/file.img in fstab and
* /dev/loop0 in mtab -- then we have to check releation
* between loopdev and the file.
*/
fs = mnt_table_find_target(fstab, tgt, MNT_ITER_FORWARD);
if (fs) {
const char *dev = mnt_fs_get_srcpath(cxt->fs); /* devname from mtab */
if (!dev || !is_associated_fs(dev, fs))
fs = NULL;
}
if (!fs) {
DBG(CXT, mnt_debug_h(cxt,
"umount %s: mtab disagrees with fstab",
tgt));
goto eperm;
}
}
/*
* User mounting and unmounting is allowed only if fstab contains one
* of the options `user', `users' or `owner' or `group'.
*
* The option `users' allows arbitrary users to mount and unmount -
* this may be a security risk.
*
* The options `user', `owner' and `group' only allow unmounting by the
* user that mounted (visible in mtab).
*/
optstr = mnt_fs_get_user_options(fs); /* FSTAB mount options! */
if (!optstr)
goto eperm;
if (mnt_optstr_get_flags(optstr, &u_flags,
mnt_get_builtin_optmap(MNT_USERSPACE_MAP)))
goto eperm;
if (u_flags & MNT_MS_USERS) {
DBG(CXT, mnt_debug_h(cxt,
"umount: promiscuous setting ('users') in fstab"));
return 0;
}
/*
* Check user=<username> setting from mtab if there is user, owner or
* group option in /etc/fstab
*/
if (u_flags & (MNT_MS_USER | MNT_MS_OWNER | MNT_MS_GROUP)) {
char *curr_user = NULL;
char *mtab_user = NULL;
size_t sz;
DBG(CXT, mnt_debug_h(cxt,
"umount: checking user=<username> from mtab"));
curr_user = mnt_get_username(getuid());
if (!curr_user) {
DBG(CXT, mnt_debug_h(cxt, "umount %s: cannot "
"convert %d to username", tgt, getuid()));
goto eperm;
}
/* get options from mtab */
optstr = mnt_fs_get_user_options(cxt->fs);
if (optstr && !mnt_optstr_get_option(optstr,
"user", &mtab_user, &sz) && sz)
ok = !strncmp(curr_user, mtab_user, sz);
}
if (ok) {
DBG(CXT, mnt_debug_h(cxt, "umount %s is allowed", tgt));
return 0;
}
eperm:
DBG(CXT, mnt_debug_h(cxt, "umount is not allowed for you"));
return -EPERM;
}
/**
* mnt_context_find_umount_fs:
* @cxt: mount context
* @tgt: mountpoint, device, ...
* @pfs: returns point to filesystem
*
* Returns: 0 on success, <0 on error, 1 if target filesystem not found
*/
int mnt_context_find_umount_fs(struct libmnt_context *cxt,
const char *tgt,
struct libmnt_fs **pfs)
{
int rc;
struct libmnt_table *mtab = NULL;
struct libmnt_fs *fs;
char *loopdev = NULL;
if (pfs)
*pfs = NULL;
if (!cxt || !tgt || !pfs)
return -EINVAL;
DBG(CXT, ul_debugobj(cxt, "umount: lookup FS for '%s'", tgt));
if (!*tgt)
return 1; /* empty string is not an error */
/*
* The mount table may be huge, and on systems with utab we have to merge
* userspace mount options into /proc/self/mountinfo. This all is
* expensive. The tab filter allows to filter out entries, then
* a mount table and utab are very tiny files.
*
* *but*... the filter uses mnt_fs_streq_{target,srcpath} functions
* where LABEL, UUID or symlinks are canonicalized. It means that
* it's usable only for canonicalized stuff (e.g. kernel mountinfo).
*/
if (!mnt_context_mtab_writable(cxt) && *tgt == '/' &&
!mnt_context_is_force(cxt) && !mnt_context_is_lazy(cxt))
rc = mnt_context_get_mtab_for_target(cxt, &mtab, tgt);
else
rc = mnt_context_get_mtab(cxt, &mtab);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "umount: failed to read mtab"));
return rc;
}
if (mnt_table_get_nents(mtab) == 0) {
DBG(CXT, ul_debugobj(cxt, "umount: mtab empty"));
return 1;
}
try_loopdev:
fs = mnt_table_find_target(mtab, tgt, MNT_ITER_BACKWARD);
if (!fs && mnt_context_is_swapmatch(cxt)) {
/*
* Maybe the option is source rather than target (sometimes
* people use e.g. "umount /dev/sda1")
*/
fs = mnt_table_find_source(mtab, tgt, MNT_ITER_BACKWARD);
if (fs) {
struct libmnt_fs *fs1 = mnt_table_find_target(mtab,
mnt_fs_get_target(fs),
MNT_ITER_BACKWARD);
if (!fs1) {
DBG(CXT, ul_debugobj(cxt, "mtab is broken?!?!"));
rc = -EINVAL;
goto err;
}
if (fs != fs1) {
/* Something was stacked over `file' on the
* same mount point. */
DBG(CXT, ul_debugobj(cxt,
"umount: %s: %s is mounted "
"over it on the same point",
tgt, mnt_fs_get_source(fs1)));
rc = -EINVAL;
goto err;
}
}
}
if (!fs && !loopdev && mnt_context_is_swapmatch(cxt)) {
/*
* Maybe the option is /path/file.img, try to convert to /dev/loopN
*/
struct stat st;
if (mnt_stat_mountpoint(tgt, &st) == 0 && S_ISREG(st.st_mode)) {
int count;
struct libmnt_cache *cache = mnt_context_get_cache(cxt);
const char *bf = cache ? mnt_resolve_path(tgt, cache) : tgt;
count = loopdev_count_by_backing_file(bf, &loopdev);
if (count == 1) {
DBG(CXT, ul_debugobj(cxt,
"umount: %s --> %s (retry)", tgt, loopdev));
tgt = loopdev;
goto try_loopdev;
} else if (count > 1)
DBG(CXT, ul_debugobj(cxt,
"umount: warning: %s is associated "
"with more than one loopdev", tgt));
}
}
if (pfs)
*pfs = fs;
free(loopdev);
DBG(CXT, ul_debugobj(cxt, "umount fs: %s", fs ? mnt_fs_get_target(fs) :
"<not found>"));
return fs ? 0 : 1;
err:
free(loopdev);
return rc;
}
static int lookup_umount_fs(struct libmnt_context *cxt)
{
int rc, loopdev = 0;
const char *tgt;
struct libmnt_table *mtab = NULL;
struct libmnt_fs *fs;
assert(cxt);
assert(cxt->fs);
DBG(CXT, mnt_debug_h(cxt, "umount: lookup FS"));
tgt = mnt_fs_get_target(cxt->fs);
if (!tgt) {
DBG(CXT, mnt_debug_h(cxt, "umount: undefined target"));
return -EINVAL;
}
rc = mnt_context_get_mtab(cxt, &mtab);
if (rc) {
DBG(CXT, mnt_debug_h(cxt, "umount: failed to read mtab"));
return rc;
}
try_loopdev:
fs = mnt_table_find_target(mtab, tgt, MNT_ITER_BACKWARD);
if (!fs) {
/* maybe the option is source rather than target (mountpoint) */
fs = mnt_table_find_source(mtab, tgt, MNT_ITER_BACKWARD);
if (fs) {
struct libmnt_fs *fs1 = mnt_table_find_target(mtab,
mnt_fs_get_target(fs),
MNT_ITER_BACKWARD);
if (!fs1) {
DBG(CXT, mnt_debug_h(cxt, "mtab is broken?!?!"));
return -EINVAL;
}
if (fs != fs1) {
/* Something was stacked over `file' on the
* same mount point. */
DBG(CXT, mnt_debug_h(cxt,
"umount: %s: %s is mounted "
"over it on the same point",
tgt, mnt_fs_get_source(fs1)));
return -EINVAL;
}
}
}
if (!fs && !loopdev) {
/*
* Maybe target is /path/file.img, try to convert to /dev/loopN
*/
struct stat st;
if (stat(tgt, &st) == 0 && S_ISREG(st.st_mode)) {
char *dev = NULL;
int count = loopdev_count_by_backing_file(tgt, &dev);
if (count == 1) {
DBG(CXT, mnt_debug_h(cxt,
"umount: %s --> %s (retry)", tgt, dev));
mnt_fs_set_source(cxt->fs, tgt);
mnt_fs_set_target(cxt->fs, dev);
free(dev);
tgt = mnt_fs_get_target(cxt->fs);
loopdev = 1; /* to avoid endless loop */
goto try_loopdev;
} else if (count > 1)
DBG(CXT, mnt_debug_h(cxt,
"umount: warning: %s is associated "
"with more than one loodev", tgt));
}
}
if (!fs) {
DBG(CXT, mnt_debug_h(cxt, "umount: cannot find %s in mtab", tgt));
return 0;
}
if (fs != cxt->fs) {
/* copy from mtab to our FS description
*/
mnt_fs_set_source(cxt->fs, NULL);
mnt_fs_set_target(cxt->fs, NULL);
if (!mnt_copy_fs(cxt->fs, fs)) {
DBG(CXT, mnt_debug_h(cxt, "umount: failed to copy FS"));
return -errno;
}
DBG(CXT, mnt_debug_h(cxt, "umount: mtab applied"));
}
cxt->flags |= MNT_FL_TAB_APPLIED;
return rc;
}
