Original ubifs code was designed that after ubifs_umount() call it is
required to also call ubi_close_volume() which closes underlying UBI
volume. But U-Boot ubifs modification have not implemented it properly
which caused that ubifsumount command contains resource leak. It can be
observed by calling simple sequence of commands:
=> ubi part mtd2
ubi0: attaching mtd2
...
=> ubifsmount ubi0
=> ubifsumount
Unmounting UBIFS volume rootfs!
=> ubi detach
ubi0 error: ubi_detach_mtd_dev: ubi0 reference count 1, destroy anyway
ubi0: detaching mtd2
ubi0: mtd2 is detached
Fix this issue by calling ubi_close_volume() and mutex_unlock() in
directly in ubifs_umount() function before freeing U-Boot's global
ubifs_sb. And remove duplicate calls of these two functions in remaining
places. Note that when ubifs_umount() is not called then during error
handling is still needed to call ubi_close_volume() and mutex_unlock.
With this change ubifsumount command does not throw that error anymore:
=> ubi part rootfs
ubi0: attaching mtd2
...
=> ubifsmount ubi0
=> ubifsumount
Unmounting UBIFS volume rootfs!
=> ubi detach
ubi0: detaching mtd2
ubi0: mtd2 is detached
Signed-off-by: Pali Rohár <p...@kernel.org>
---
Changes in v2:
* Fix error handling in ubifs_fill_super()
---
fs/ubifs/super.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index e3a4c0bca270..034c41a70356 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1757,6 +1757,8 @@ void ubifs_umount(struct ubifs_info *c)
kfree(c->bottom_up_buf);
ubifs_debugging_exit(c);
#ifdef __UBOOT__
+ ubi_close_volume(c->ubi);
+ mutex_unlock(&c->umount_mutex);
/* Finally free U-Boot's global copy of superblock */
if (ubifs_sb != NULL) {
free(ubifs_sb->s_fs_info);
@@ -2058,9 +2060,9 @@ static void ubifs_put_super(struct super_block *sb)
ubifs_umount(c);
#ifndef __UBOOT__
bdi_destroy(&c->bdi);
-#endif
ubi_close_volume(c->ubi);
mutex_unlock(&c->umount_mutex);
+#endif
}
#endif
@@ -2327,6 +2329,9 @@ static int ubifs_fill_super(struct super_block *sb, void
*data, int silent)
out_umount:
ubifs_umount(c);
+#ifdef __UBOOT__
+ goto out;
+#endif
out_unlock:
mutex_unlock(&c->umount_mutex);
#ifndef __UBOOT__
--
2.20.1
