UBIFS: support mounting of UBI volume character devices
This patch makes it possible to mount UBI character device
nodes, and use something like:
$ mount -t ubifs /dev/ubi_volume_name /mnt/ubifs
instead of the old restrictive 'nodev' semantics:
$ mount -t ubifs ubi0_0 /mnt/ubifs
[Comments and the patch were amended a bit by Artem]
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 333e181e..943ad56 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1842,22 +1842,32 @@
* @name: UBI volume name
* @mode: UBI volume open mode
*
- * There are several ways to specify UBI volumes when mounting UBIFS:
- * o ubiX_Y - UBI device number X, volume Y;
- * o ubiY - UBI device number 0, volume Y;
+ * The primary method of mounting UBIFS is by specifying the UBI volume
+ * character device node path. However, UBIFS may also be mounted withoug any
+ * character device node using one of the following methods:
+ *
+ * o ubiX_Y - mount UBI device number X, volume Y;
+ * o ubiY - mount UBI device number 0, volume Y;
* o ubiX:NAME - mount UBI device X, volume with name NAME;
* o ubi:NAME - mount UBI device 0, volume with name NAME.
*
* Alternative '!' separator may be used instead of ':' (because some shells
* like busybox may interpret ':' as an NFS host name separator). This function
- * returns ubi volume object in case of success and a negative error code in
- * case of failure.
+ * returns UBI volume description object in case of success and a negative
+ * error code in case of failure.
*/
static struct ubi_volume_desc *open_ubi(const char *name, int mode)
{
+ struct ubi_volume_desc *ubi;
int dev, vol;
char *endptr;
+ /* First, try to open using the device node path method */
+ ubi = ubi_open_volume_path(name, mode);
+ if (!IS_ERR(ubi))
+ return ubi;
+
+ /* Try the "nodev" method */
if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
return ERR_PTR(-EINVAL);