This is a note to let you know that I've just added the patch titled
btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-handle-chunk-tree-lookup-error-in-btrfs_reloca.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d2faececc38907c88d41eec572916ef5c7c02229
Author: David Sterba <dsterba@xxxxxxxx>
Date: Tue Jan 23 23:42:29 2024 +0100
btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()
[ Upstream commit 7411055db5ce64f836aaffd422396af0075fdc99 ]
The unhandled case in btrfs_relocate_sys_chunks() loop is a corruption,
as it could be caused only by two impossible conditions:
- at first the search key is set up to look for a chunk tree item, with
offset -1, this is an inexact search and the key->offset will contain
the correct offset upon a successful search, a valid chunk tree item
cannot have an offset -1
- after first successful search, the found_key corresponds to a chunk
item, the offset is decremented by 1 before the next loop, it's
impossible to find a chunk item there due to alignment and size
constraints
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index ceced5e56c5a9..30b5646b2c0de 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2948,7 +2948,17 @@ static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
}
- BUG_ON(ret == 0); /* Corruption */
+ if (ret == 0) {
+ /*
+ * On the first search we would find chunk tree with
+ * offset -1, which is not possible. On subsequent
+ * loops this would find an existing item on an invalid
+ * offset (one less than the previous one, wrong
+ * alignment and size).
+ */
+ ret = -EUCLEAN;
+ goto error;
+ }
ret = btrfs_previous_item(chunk_root, path, key.objectid,
key.type);
