From: Josef Bacik josef@toxicpanda.com
commit ad24466588ab7d7c879053c5afd919b0c555fec0 upstream.
When flipping over to the rw_semaphore I noticed I'd get a lockdep splat in replace_path(), which is weird because we're swapping the reloc root with the actual target root. Turns out this is because we're using the root->root_key.objectid as the root id for the newly allocated tree block when setting the lockdep class, however we need to be using the actual owner of this new block, which is saved in owner.
The affected path is through btrfs_copy_root as all other callers of btrfs_alloc_tree_block (which calls init_new_buffer) have root_objectid == root->root_key.objectid .
CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Filipe Manana fdmanana@suse.com Reviewed-by: Nikolay Borisov nborisov@suse.com Signed-off-by: Josef Bacik josef@toxicpanda.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/extent-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4527,7 +4527,7 @@ btrfs_init_new_buffer(struct btrfs_trans return ERR_PTR(-EUCLEAN); }
- btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level); + btrfs_set_buffer_lockdep_class(owner, buf, level); btrfs_tree_lock(buf); btrfs_clean_tree_block(buf); clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);