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. 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 pali@kernel.org --- fs/ubifs/super.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index e3a4c0bca270..7677dcc2a140 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
@@ -2328,13 +2330,13 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) out_umount: ubifs_umount(c); out_unlock: - mutex_unlock(&c->umount_mutex); #ifndef __UBOOT__ + mutex_unlock(&c->umount_mutex); out_bdi: bdi_destroy(&c->bdi); out_close: -#endif ubi_close_volume(c->ubi); +#endif out: return err; }