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(LOOP, ul_debugobj(cxt, "loopdev specific options detected"));
return 1;
}
if ((cxt->mountflags & (MS_BIND | MS_MOVE))
|| mnt_context_propagation_only(cxt))
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 an empty loopdev with
* no mountable filesystem...
*
* Note that there is no restriction (on kernel side) that would prevent a 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(LOOP, ul_debugobj(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;
}
int mnt_context_is_loopdev(struct libmnt_context *cxt)
{
const char *type, *src;
int fl;
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))
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).
*
* 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);
fl = __mnt_fs_get_flags(cxt->fs);
if (!(fl && (MNT_FS_PSEUDO | MNT_FS_NET | MNT_FS_SWAP)) &&
(!type || strcmp(type, "auto") == 0 || blkid_known_fstype(type))) {
struct stat st;
if (stat(src, &st) || !S_ISREG(st.st_mode))
return 0;
}
return 1;
}
static virStoragePoolProbeResult
virStorageBackendFileSystemProbe(const char *device,
const char *format) {
virStoragePoolProbeResult ret = FILESYSTEM_PROBE_ERROR;
blkid_probe probe = NULL;
const char *fstype = NULL;
char *names[2], *libblkid_format = NULL;
VIR_DEBUG("Probing for existing filesystem of type %s on device %s",
format, device);
if (blkid_known_fstype(format) == 0) {
virStorageReportError(VIR_ERR_STORAGE_PROBE_FAILED,
_("Not capable of probing for "
"filesystem of type %s"),
format);
goto error;
}
probe = blkid_new_probe_from_filename(device);
if (probe == NULL) {
virStorageReportError(VIR_ERR_STORAGE_PROBE_FAILED,
_("Failed to create filesystem probe "
"for device %s"),
device);
goto error;
}
if ((libblkid_format = strdup(format)) == NULL) {
virReportOOMError();
goto error;
}
names[0] = libblkid_format;
names[1] = NULL;
blkid_probe_filter_superblocks_type(probe,
BLKID_FLTR_ONLYIN,
names);
if (blkid_do_probe(probe) != 0) {
VIR_INFO("No filesystem of type '%s' found on device '%s'",
format, device);
ret = FILESYSTEM_PROBE_NOT_FOUND;
} else if (blkid_probe_lookup_value(probe, "TYPE", &fstype, NULL) == 0) {
virStorageReportError(VIR_ERR_STORAGE_POOL_BUILT,
_("Existing filesystem of type '%s' found on "
"device '%s'"),
fstype, device);
ret = FILESYSTEM_PROBE_FOUND;
}
if (blkid_do_probe(probe) != 1) {
virStorageReportError(VIR_ERR_STORAGE_PROBE_FAILED,
_("Found additional probes to run, "
"filesystem probing may be incorrect"));
ret = FILESYSTEM_PROBE_ERROR;
}
error:
VIR_FREE(libblkid_format);
if (probe != NULL) {
blkid_free_probe(probe);
}
return ret;
}
int
fsprobe_known_fstype(const char *fstype)
{
return blkid_known_fstype(fstype);
}
