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);
}
/* check if @devname is loopdev and if the device is associated
* with a source from @fstab_fs
*/
static int is_associated_fs(const char *devname, struct libmnt_fs *fs)
{
uintmax_t offset = 0;
const char *src;
char *val, *optstr;
size_t valsz;
int flags = 0;
/* check if it begins with /dev/loop */
if (strncmp(devname, _PATH_DEV_LOOP, sizeof(_PATH_DEV_LOOP) - 1))
return 0;
src = mnt_fs_get_srcpath(fs);
if (!src)
return 0;
/* check for offset option in @fs */
optstr = (char *) mnt_fs_get_user_options(fs);
if (optstr &&
mnt_optstr_get_option(optstr, "offset", &val, &valsz) == 0) {
flags |= LOOPDEV_FL_OFFSET;
if (mnt_parse_offset(val, valsz, &offset) != 0)
return 0;
}
return loopdev_is_used(devname, src, offset, flags);
}
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;
}
/*
* Store mount options to mtab (or /dev/.mount/utab), called from mount.nfs.
*
* Note that on systems without /etc/mtab the fs-specific options are not
* managed by libmount at all. We have to use "mount attributes" that are
* private for mount.<type> helpers.
*/
static void store_mount_options(struct libmnt_fs *fs, const char *nfs_opts)
{
char *o = NULL;
mnt_fs_set_attributes(fs, nfs_opts); /* for non-mtab systems */
/* for mtab create a new options list */
mnt_optstr_append_option(&o, mnt_fs_get_vfs_options(fs), NULL);
mnt_optstr_append_option(&o, nfs_opts, NULL);
mnt_optstr_append_option(&o, mnt_fs_get_user_options(fs), NULL);
mnt_fs_set_options(fs, o);
free(o);
}
/*
* 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;
}
/*
* 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_next_mount:
* @cxt: context
* @itr: iterator
* @fs: returns the current filesystem
* @mntrc: returns the return code from mnt_context_mount()
* @ignored: returns 1 for not matching and 2 for already mounted filesystems
*
* This function tries to mount the next filesystem from fstab (as returned by
* mnt_context_get_fstab()). See also mnt_context_set_fstab().
*
* You can filter out filesystems by:
* mnt_context_set_options_pattern() to simulate mount -a -O pattern
* mnt_context_set_fstype_pattern() to simulate mount -a -t pattern
*
* If the filesystem is already mounted or does not match defined criteria,
* then the mnt_context_next_mount() function returns zero, but the @ignored is
* non-zero. Note that the root filesystem and filesystems with "noauto" option
* are always ignored.
*
* If mount(2) syscall or mount.type helper failed, then the
* mnt_context_next_mount() function returns zero, but the @mntrc is non-zero.
* Use also mnt_context_get_status() to check if the filesystem was
* successfully mounted.
*
* Returns: 0 on success,
* <0 in case of error (!= mount(2) errors)
* 1 at the end of the list.
*/
int mnt_context_next_mount(struct libmnt_context *cxt,
struct libmnt_iter *itr,
struct libmnt_fs **fs,
int *mntrc,
int *ignored)
{
struct libmnt_table *fstab, *mtab;
const char *o, *tgt;
int rc, mounted = 0;
if (ignored)
*ignored = 0;
if (mntrc)
*mntrc = 0;
if (!cxt || !fs || !itr)
return -EINVAL;
mtab = cxt->mtab;
cxt->mtab = NULL; /* do not reset mtab */
mnt_reset_context(cxt);
cxt->mtab = mtab;
rc = mnt_context_get_fstab(cxt, &fstab);
if (rc)
return rc;
rc = mnt_table_next_fs(fstab, itr, fs);
if (rc != 0)
return rc; /* more filesystems (or error) */
o = mnt_fs_get_user_options(*fs);
tgt = mnt_fs_get_target(*fs);
DBG(CXT, mnt_debug_h(cxt, "next-mount: trying %s", tgt));
/* ignore swap */
if (mnt_fs_is_swaparea(*fs) ||
/* ignore root filesystem */
(tgt && (strcmp(tgt, "/") == 0 || strcmp(tgt, "root") == 0)) ||
/* ignore noauto filesystems */
(o && mnt_optstr_get_option(o, "noauto", NULL, NULL) == 0) ||
/* ignore filesystems not match with options patterns */
(cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
cxt->fstype_pattern)) ||
/* ignore filesystems not match with type patterns */
(cxt->optstr_pattern && !mnt_fs_match_options(*fs,
cxt->optstr_pattern))) {
if (ignored)
*ignored = 1;
DBG(CXT, mnt_debug_h(cxt, "next-mount: not-match "
"[fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]",
mnt_fs_get_fstype(*fs),
cxt->fstype_pattern,
mnt_fs_get_options(*fs),
cxt->optstr_pattern));
return 0;
}
/* ignore already mounted filesystems */
rc = mnt_context_is_fs_mounted(cxt, *fs, &mounted);
if (rc)
return rc;
if (mounted) {
if (ignored)
*ignored = 2;
return 0;
}
if (mnt_context_is_fork(cxt)) {
rc = mnt_fork_context(cxt);
if (rc)
return rc; /* fork error */
if (mnt_context_is_parent(cxt)) {
return 0; /* parent */
}
}
/* child or non-forked */
rc = mnt_context_set_fs(cxt, *fs);
if (!rc) {
rc = mnt_context_mount(cxt);
if (mntrc)
*mntrc = rc;
}
if (mnt_context_is_child(cxt)) {
DBG(CXT, mnt_debug_h(cxt, "next-mount: child exit [rc=%d]", rc));
DBG_FLUSH;
exit(rc);
}
return 0;
}
int mnt_context_setup_loopdev(struct libmnt_context *cxt)
{
const char *backing_file, *optstr, *loopdev = NULL;
char *val = NULL, *loopval = NULL;
size_t len;
struct loopdev_cxt lc;
int rc = 0, lo_flags = 0;
uint64_t offset = 0, sizelimit = 0;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
backing_file = mnt_fs_get_srcpath(cxt->fs);
if (!backing_file)
return -EINVAL;
DBG(LOOP, ul_debugobj(cxt, "trying to setup device for %s", backing_file));
if (cxt->mountflags & MS_RDONLY) {
DBG(LOOP, ul_debugobj(cxt, "enabling READ-ONLY flag"));
lo_flags |= LO_FLAGS_READ_ONLY;
}
optstr = mnt_fs_get_user_options(cxt->fs);
/*
* loop=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_LOOP) &&
mnt_optstr_get_option(optstr, "loop", &val, &len) == 0 && val) {
loopval = strndup(val, len);
rc = loopval ? 0 : -ENOMEM;
}
/*
* offset=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_OFFSET) &&
mnt_optstr_get_option(optstr, "offset", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &offset);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to parse offset="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* sizelimit=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_SIZELIMIT) &&
mnt_optstr_get_option(optstr, "sizelimit", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &sizelimit);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to parse sizelimit="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* encryption=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_ENCRYPTION) &&
mnt_optstr_get_option(optstr, "encryption", &val, &len) == 0) {
DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported"));
rc = -MNT_ERR_MOUNTOPT;
}
if (rc == 0 && is_mounted_same_loopfile(cxt,
mnt_context_get_target(cxt),
backing_file, offset))
rc = -EBUSY;
if (rc)
goto done_no_deinit;
/* It is possible to mount the same file more times. If we set more
* than one loop device referring to the same file, kernel has no
* mechanism to detect it. To prevent data corruption, the same loop
* device has to be recycled.
*/
if (backing_file) {
rc = loopcxt_init(&lc, 0);
if (rc)
goto done_no_deinit;
rc = loopcxt_find_overlap(&lc, backing_file, offset, sizelimit);
switch (rc) {
case 0: /* not found */
DBG(LOOP, ul_debugobj(cxt, "not found overlaping loopdev"));
loopcxt_deinit(&lc);
break;
case 1: /* overlap */
DBG(LOOP, ul_debugobj(cxt, "overlaping %s detected",
loopcxt_get_device(&lc)));
rc = -MNT_ERR_LOOPOVERLAP;
goto done;
case 2: /* overlap -- full size and offset match (reuse) */
{
uint32_t lc_encrypt_type;
DBG(LOOP, ul_debugobj(cxt, "re-using existing loop device %s",
loopcxt_get_device(&lc)));
/* Once a loop is initialized RO, there is no
* way to change its parameters. */
if (loopcxt_is_readonly(&lc)
&& !(lo_flags & LO_FLAGS_READ_ONLY)) {
DBG(LOOP, ul_debugobj(cxt, "%s is read-only",
loopcxt_get_device(&lc)));
rc = -EROFS;
goto done;
}
/* This is no more supported, but check to be safe. */
if (loopcxt_get_encrypt_type(&lc, &lc_encrypt_type) == 0
&& lc_encrypt_type != LO_CRYPT_NONE) {
DBG(LOOP, ul_debugobj(cxt, "encryption no longer supported for device %s",
loopcxt_get_device(&lc)));
rc = -MNT_ERR_LOOPOVERLAP;
goto done;
}
rc = 0;
goto success;
}
default: /* error */
goto done;
}
}
DBG(LOOP, ul_debugobj(cxt, "not found; create a new loop device"));
rc = loopcxt_init(&lc, 0);
if (rc)
goto done_no_deinit;
if (loopval) {
rc = loopcxt_set_device(&lc, loopval);
if (rc == 0)
loopdev = loopcxt_get_device(&lc);
}
if (rc)
goto done;
/* since 2.6.37 we don't have to store backing filename to mtab
* because kernel provides the name in /sys.
*/
if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
!mnt_context_mtab_writable(cxt)) {
DBG(LOOP, ul_debugobj(cxt, "enabling AUTOCLEAR flag"));
lo_flags |= LO_FLAGS_AUTOCLEAR;
}
do {
/* found free device */
if (!loopdev) {
rc = loopcxt_find_unused(&lc);
if (rc)
goto done;
DBG(LOOP, ul_debugobj(cxt, "trying to use %s",
loopcxt_get_device(&lc)));
}
/* set device attributes
* -- note that loopcxt_find_unused() resets "lc"
*/
rc = loopcxt_set_backing_file(&lc, backing_file);
if (!rc && offset)
rc = loopcxt_set_offset(&lc, offset);
if (!rc && sizelimit)
rc = loopcxt_set_sizelimit(&lc, sizelimit);
if (!rc)
loopcxt_set_flags(&lc, lo_flags);
if (rc) {
DBG(LOOP, ul_debugobj(cxt, "failed to set loop attributes"));
goto done;
}
/* setup the device */
rc = loopcxt_setup_device(&lc);
if (!rc)
break; /* success */
if (loopdev || rc != -EBUSY) {
DBG(LOOP, ul_debugobj(cxt, "failed to setup device"));
rc = -MNT_ERR_LOOPDEV;
goto done;
}
DBG(LOOP, ul_debugobj(cxt, "device stolen...trying again"));
} while (1);
success:
if (!rc)
rc = mnt_fs_set_source(cxt->fs, loopcxt_get_device(&lc));
if (!rc) {
/* success */
cxt->flags |= MNT_FL_LOOPDEV_READY;
if ((cxt->user_mountflags & MNT_MS_LOOP) &&
loopcxt_is_autoclear(&lc)) {
/*
* autoclear flag accepted by the kernel, don't store
* the "loop=" option to mtab.
*/
DBG(LOOP, ul_debugobj(cxt, "removing unnecessary loop= from mtab"));
cxt->user_mountflags &= ~MNT_MS_LOOP;
mnt_optstr_remove_option(&cxt->fs->user_optstr, "loop");
}
if (!(cxt->mountflags & MS_RDONLY) &&
loopcxt_is_readonly(&lc))
/*
* mount planned read-write, but loopdev is read-only,
* let's fix mount options...
*/
mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
/* we have to keep the device open until mount(1),
* otherwise it will be auto-cleared by kernel
*/
cxt->loopdev_fd = loopcxt_get_fd(&lc);
if (cxt->loopdev_fd < 0) {
DBG(LOOP, ul_debugobj(cxt, "failed to get loopdev FD"));
rc = -errno;
} else
loopcxt_set_fd(&lc, -1, 0);
}
done:
loopcxt_deinit(&lc);
done_no_deinit:
free(loopval);
return rc;
}
int mnt_context_setup_loopdev(struct libmnt_context *cxt)
{
const char *backing_file, *optstr, *loopdev = NULL;
char *val = NULL;
size_t len;
struct loopdev_cxt lc;
int rc = 0, lo_flags = 0;
uint64_t offset = 0, sizelimit = 0;
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!cxt)
return -EINVAL;
backing_file = mnt_fs_get_srcpath(cxt->fs);
if (!backing_file)
return -EINVAL;
DBG(CXT, ul_debugobj(cxt, "trying to setup loopdev for %s", backing_file));
if (cxt->mountflags & MS_RDONLY) {
DBG(CXT, ul_debugobj(cxt, "enabling READ-ONLY flag"));
lo_flags |= LO_FLAGS_READ_ONLY;
}
rc = loopcxt_init(&lc, 0);
if (rc)
return rc;
ON_DBG(CXT, loopcxt_enable_debug(&lc, 1));
optstr = mnt_fs_get_user_options(cxt->fs);
/*
* loop=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_LOOP) &&
mnt_optstr_get_option(optstr, "loop", &val, &len) == 0 && val) {
val = strndup(val, len);
rc = val ? loopcxt_set_device(&lc, val) : -ENOMEM;
free(val);
if (rc == 0)
loopdev = loopcxt_get_device(&lc);
}
/*
* offset=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_OFFSET) &&
mnt_optstr_get_option(optstr, "offset", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &offset);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to parse offset="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* sizelimit=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_SIZELIMIT) &&
mnt_optstr_get_option(optstr, "sizelimit", &val, &len) == 0) {
rc = mnt_parse_offset(val, len, &sizelimit);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to parse sizelimit="));
rc = -MNT_ERR_MOUNTOPT;
}
}
/*
* encryption=
*/
if (rc == 0 && (cxt->user_mountflags & MNT_MS_ENCRYPTION) &&
mnt_optstr_get_option(optstr, "encryption", &val, &len) == 0) {
DBG(CXT, ul_debugobj(cxt, "encryption no longer supported"));
rc = -MNT_ERR_MOUNTOPT;
}
if (rc == 0 && is_mounted_same_loopfile(cxt,
mnt_context_get_target(cxt),
backing_file, offset))
rc = -EBUSY;
if (rc)
goto done;
/* since 2.6.37 we don't have to store backing filename to mtab
* because kernel provides the name in /sys.
*/
if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
!mnt_context_mtab_writable(cxt)) {
DBG(CXT, ul_debugobj(cxt, "enabling AUTOCLEAR flag"));
lo_flags |= LO_FLAGS_AUTOCLEAR;
}
do {
/* found free device */
if (!loopdev) {
rc = loopcxt_find_unused(&lc);
if (rc)
goto done;
DBG(CXT, ul_debugobj(cxt, "trying to use %s",
loopcxt_get_device(&lc)));
}
/* set device attributes
* -- note that loopcxt_find_unused() resets "lc"
*/
rc = loopcxt_set_backing_file(&lc, backing_file);
if (!rc && offset)
rc = loopcxt_set_offset(&lc, offset);
if (!rc && sizelimit)
rc = loopcxt_set_sizelimit(&lc, sizelimit);
if (!rc)
loopcxt_set_flags(&lc, lo_flags);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to set loopdev attributes"));
goto done;
}
/* setup the device */
rc = loopcxt_setup_device(&lc);
if (!rc)
break; /* success */
if (loopdev || rc != -EBUSY) {
DBG(CXT, ul_debugobj(cxt, "failed to setup device"));
rc = -MNT_ERR_LOOPDEV;
goto done;
}
DBG(CXT, ul_debugobj(cxt, "loopdev stolen...trying again"));
} while (1);
if (!rc)
rc = mnt_fs_set_source(cxt->fs, loopcxt_get_device(&lc));
if (!rc) {
/* success */
cxt->flags |= MNT_FL_LOOPDEV_READY;
if ((cxt->user_mountflags & MNT_MS_LOOP) &&
loopcxt_is_autoclear(&lc)) {
/*
* autoclear flag accepted by the kernel, don't store
* the "loop=" option to mtab.
*/
cxt->user_mountflags &= ~MNT_MS_LOOP;
mnt_optstr_remove_option(&cxt->fs->user_optstr, "loop");
}
if (!(cxt->mountflags & MS_RDONLY) &&
loopcxt_is_readonly(&lc))
/*
* mount planned read-write, but loopdev is read-only,
* let's fix mount options...
*/
mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
/* we have to keep the device open until mount(1),
* otherwise it will be auto-cleared by kernel
*/
cxt->loopdev_fd = loopcxt_get_fd(&lc);
loopcxt_set_fd(&lc, -1, 0);
}
done:
loopcxt_deinit(&lc);
return rc;
}
/*
* Allocates utab entry (upd->fs) for mount/remount. This function should be
* called *before* mount(2) syscall. The @fs is used as a read-only template.
*
* Returns: 0 on success, negative number on error, 1 if utabs update is
* unnecessary.
*/
static int utab_new_entry(struct libmnt_update *upd, struct libmnt_fs *fs,
unsigned long mountflags)
{
int rc = 0;
const char *o = NULL, *a = NULL;
char *u = NULL;
assert(fs);
assert(upd);
assert(upd->fs == NULL);
assert(!(mountflags & MS_MOVE));
DBG(UPDATE, mnt_debug("prepare utab entry"));
o = mnt_fs_get_user_options(fs);
a = mnt_fs_get_attributes(fs);
upd->fs = NULL;
if (o) {
/* remove non-mtab options */
rc = mnt_optstr_get_options(o, &u,
mnt_get_builtin_optmap(MNT_USERSPACE_MAP),
MNT_NOMTAB);
if (rc)
goto err;
}
if (!u && !a) {
DBG(UPDATE, mnt_debug("utab entry unnecessary (no options)"));
return 1;
}
/* allocate the entry */
upd->fs = mnt_copy_fs(NULL, fs);
if (!upd->fs) {
rc = -ENOMEM;
goto err;
}
rc = mnt_fs_set_options(upd->fs, u);
if (rc)
goto err;
rc = mnt_fs_set_attributes(upd->fs, a);
if (rc)
goto err;
if (!(mountflags & MS_REMOUNT)) {
rc = set_fs_root(upd, fs, mountflags);
if (rc)
goto err;
}
free(u);
DBG(UPDATE, mnt_debug("utab entry OK"));
return 0;
err:
free(u);
mnt_free_fs(upd->fs);
upd->fs = NULL;
return rc;
}
