static struct libmnt_fs *add_dummy_fs(const char *device)
{
struct libmnt_fs *fs = mnt_new_fs();
if (fs && mnt_fs_set_source(fs, device) == 0 &&
mnt_table_add_fs(fstab, fs) == 0)
return fs;
mnt_free_fs(fs);
err(FSCK_EX_ERROR, _("failed to setup description for %s"), device);
}
static int test_move(struct libmnt_test *ts, int argc, char *argv[])
{
struct libmnt_fs *fs = mnt_new_fs();
int rc;
if (argc < 3)
return -1;
mnt_fs_set_source(fs, argv[1]);
mnt_fs_set_target(fs, argv[2]);
rc = update(NULL, fs, MS_MOVE);
mnt_free_fs(fs);
return rc;
}
static int test_add(struct libmnt_test *ts, int argc, char *argv[])
{
struct libmnt_fs *fs = mnt_new_fs();
int rc;
if (argc < 5 || !fs)
return -1;
mnt_fs_set_source(fs, argv[1]);
mnt_fs_set_target(fs, argv[2]);
mnt_fs_set_fstype(fs, argv[3]);
mnt_fs_set_options(fs, argv[4]);
rc = update(NULL, fs, 0);
mnt_free_fs(fs);
return rc;
}
/*
* Parses one line from /proc/swaps
*/
static int mnt_parse_swaps_line(struct libmnt_fs *fs, char *s)
{
uintmax_t fsz, usz;
int rc;
char *src = NULL;
rc = sscanf(s, UL_SCNsA" " /* (1) source */
UL_SCNsA" " /* (2) type */
"%jd" /* (3) size */
"%jd" /* (4) used */
"%d", /* priority */
&src,
&fs->swaptype,
&fsz,
&usz,
&fs->priority);
if (rc == 5) {
size_t sz;
fs->size = fsz;
fs->usedsize = usz;
unmangle_string(src);
/* remove "(deleted)" suffix */
sz = strlen(src);
if (sz > PATH_DELETED_SUFFIX_SZ) {
char *p = src + (sz - PATH_DELETED_SUFFIX_SZ);
if (strcmp(p, PATH_DELETED_SUFFIX) == 0)
*p = '\0';
}
rc = mnt_fs_set_source(fs, src);
if (!rc)
mnt_fs_set_fstype(fs, "swap");
free(src);
} else {
DBG(TAB, mnt_debug("tab parse error: [sscanf rc=%d]: '%s'", rc, s));
rc = -EINVAL;
}
return rc;
}
/*
* Sets fs-root and fs-type to @upd->fs according to the @fs template and
* @mountfalgs. For MS_BIND mountflag it reads information about source
* filesystem from /proc/self/mountinfo.
*/
static int set_fs_root(struct libmnt_update *upd, struct libmnt_fs *fs,
unsigned long mountflags)
{
struct libmnt_fs *src_fs;
char *fsroot = NULL;
const char *src;
int rc = 0;
DBG(UPDATE, mnt_debug("setting FS root"));
assert(upd);
assert(upd->fs);
assert(fs);
if (mountflags & MS_BIND) {
if (!upd->mountinfo)
upd->mountinfo = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
src = mnt_fs_get_srcpath(fs);
if (src) {
rc = mnt_fs_set_bindsrc(upd->fs, src);
if (rc)
goto err;
}
}
src_fs = mnt_table_get_fs_root(upd->mountinfo, fs,
mountflags, &fsroot);
if (src_fs) {
src = mnt_fs_get_srcpath(src_fs);
rc = mnt_fs_set_source(upd->fs, src);
if (rc)
goto err;
mnt_fs_set_fstype(upd->fs, mnt_fs_get_fstype(src_fs));
}
upd->fs->root = fsroot;
return 0;
err:
free(fsroot);
return rc;
}
static int kernel_fs_postparse(struct libmnt_table *tb,
struct libmnt_fs *fs, pid_t *tid,
const char *filename)
{
int rc = 0;
const char *src = mnt_fs_get_srcpath(fs);
/* This is a filesystem description from /proc, so we're in some process
* namespace. Let's remember the process PID.
*/
if (filename && *tid == -1)
*tid = path_to_tid(filename);
fs->tid = *tid;
/*
* Convert obscure /dev/root to something more usable
*/
if (src && strcmp(src, "/dev/root") == 0) {
char *spec = mnt_get_kernel_cmdline_option("root=");
char *real = NULL;
DBG(TAB, mnt_debug_h(tb, "root FS: %s", spec));
if (spec)
real = mnt_resolve_spec(spec, tb->cache);
if (real) {
DBG(TAB, mnt_debug_h(tb, "canonical root FS: %s", real));
rc = mnt_fs_set_source(fs, real);
if (!tb->cache)
free(real);
}
free(spec);
}
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;
}
/* this is umount replacement to mnt_context_apply_fstab(), use
* mnt_context_tab_applied() to check result.
*/
static int lookup_umount_fs(struct libmnt_context *cxt)
{
const char *tgt;
struct stat st;
struct libmnt_fs *fs = NULL;
int rc = 0;
assert(cxt);
assert(cxt->fs);
tgt = mnt_fs_get_target(cxt->fs);
if (!tgt) {
DBG(CXT, ul_debugobj(cxt, "umount: undefined target"));
return -EINVAL;
}
/*
* Let's try to avoid mountinfo usage at all to minimize performance
* degradation. Don't forget that kernel has to compose *whole*
* mountinfo about all mountpoints although we look for only one entry.
*
* All we need is fstype and to check if there is no userspace mount
* options for the target (e.g. helper=udisks to call /sbin/umount.udisks).
*
* So, let's use statfs() if possible (it's bad idea for --lazy/--force
* umounts as target is probably unreachable NFS, also for --detach-loop
* as this additionally needs to know the name of the loop device).
*/
if (!mnt_context_is_restricted(cxt)
&& *tgt == '/'
&& !(cxt->flags & MNT_FL_HELPER)
&& !mnt_context_mtab_writable(cxt)
&& !mnt_context_is_force(cxt)
&& !mnt_context_is_lazy(cxt)
&& !mnt_context_is_loopdel(cxt)
&& mnt_stat_mountpoint(tgt, &st) == 0 && S_ISDIR(st.st_mode)
&& !has_utab_entry(cxt, tgt)) {
const char *type = mnt_fs_get_fstype(cxt->fs);
/* !mnt_context_mtab_writable(cxt) && has_utab_entry() verified that there
* is no stuff in utab, so disable all mtab/utab related actions */
mnt_context_disable_mtab(cxt, TRUE);
if (!type) {
struct statfs vfs;
if (statfs(tgt, &vfs) == 0)
type = mnt_statfs_get_fstype(&vfs);
if (type) {
rc = mnt_fs_set_fstype(cxt->fs, type);
if (rc)
return rc;
}
}
if (type) {
DBG(CXT, ul_debugobj(cxt,
"umount: mountinfo unnecessary [type=%s]", type));
return 0;
}
}
rc = mnt_context_find_umount_fs(cxt, tgt, &fs);
if (rc < 0)
return rc;
if (rc == 1 || !fs) {
DBG(CXT, ul_debugobj(cxt, "umount: cannot find '%s' in mtab", tgt));
return 0; /* this is correct! */
}
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, ul_debugobj(cxt, "umount: failed to copy FS"));
return -errno;
}
DBG(CXT, ul_debugobj(cxt, "umount: mtab applied"));
}
cxt->flags |= MNT_FL_TAB_APPLIED;
return rc;
}
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;
}
int mnt_context_setup_loopdev(struct libmnt_context *cxt)
{
const char *backing_file;
char *loopdev = NULL;
size_t len;
struct loopdev_cxt lc;
int rc, lo_flags = 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(CXT, mnt_debug_h(cxt, "trying to setup loopdev for %s", backing_file));
if (cxt->mountflags & MS_RDONLY) {
DBG(CXT, mnt_debug_h(cxt, "enabling READ-ONLY flag"));
lo_flags |= LO_FLAGS_READ_ONLY;
}
loopcxt_init(&lc, 0);
if ((cxt->user_mountflags & MNT_MS_LOOP) &&
mnt_fs_get_option(cxt->fs, "loop", &loopdev, &len) == 0 && loopdev) {
char *tmp = strndup(loopdev, len);
if (!tmp)
rc = -ENOMEM;
else {
rc = loopcxt_set_device(&lc, tmp);
free(tmp);
}
}
/* 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) ||
!cxt->mtab_writable) {
DBG(CXT, mnt_debug_h(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, mnt_debug_h(cxt, "trying to use %s",
loopcxt_get_device(&lc)));
}
/* set device attributes */
rc = loopcxt_set_backing_file(&lc, backing_file);
if (rc)
goto done;
loopcxt_set_flags(&lc, lo_flags);
/* setup the device */
rc = loopcxt_setup_device(&lc);
if (!rc)
break; /* success */
if (loopdev || rc != -EBUSY) {
DBG(CXT, mnt_debug_h(cxt, "failed to setup device"));
break;
}
DBG(CXT, mnt_debug_h(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 kernel, don't store
* the "loop=" option to mtab.
*/
cxt->user_mountflags &= ~MNT_MS_LOOP;
if (!(cxt->mountflags & MS_RDONLY) &&
loopcxt_is_readonly(&lc))
/*
* mount planned read-write, but loopdev is read-only,
* let's fix mount options...
*/
cxt->mountflags |= MS_RDONLY;
/* we have to keep the device open until mount(1),
* otherwise it will auto-cleared by kernel
*/
cxt->loopdev_fd = loopcxt_get_fd(&lc);
loopcxt_set_fd(&lc, -1, 0);
}
done:
loopcxt_deinit(&lc);
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;
}
