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 pali@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__