Btrfs: remove assertion when searching for a key in a node/leaf

fdmanana · kdave · commit 253002f2e3f4 · 2019-02-25T14:19:23.000+01:00
At ctree.c:key_search(), the assertion that verifies the first key on a child extent buffer corresponds to the key at a specific slot in the parent has a disadvantage: we effectively hit a BUG_ON() which requires rebooting the machine later. It also does not tell any information about which extent buffer is affected, from which root, the expected and found keys, etc. However as of commit 581c176 ("btrfs: Validate child tree block's level and first key"), that assertion is not needed since at the time we read an extent buffer from disk we validate that its first key matches the key, at the respective slot, in the parent extent buffer. Therefore just remove the assertion at key_search(). Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
@@ -2544,26 +2544,6 @@ setup_nodes_for_search(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static void key_search_validate(struct extent_buffer *b,
-				const struct btrfs_key *key,
-				int level)
-{
-#ifdef CONFIG_BTRFS_ASSERT
-	struct btrfs_disk_key disk_key;
-
-	btrfs_cpu_key_to_disk(&disk_key, key);
-
-	if (level == 0)
-		ASSERT(!memcmp_extent_buffer(b, &disk_key,
-		    offsetof(struct btrfs_leaf, items[0].key),
-		    sizeof(disk_key)));
-	else
-		ASSERT(!memcmp_extent_buffer(b, &disk_key,
-		    offsetof(struct btrfs_node, ptrs[0].key),
-		    sizeof(disk_key)));
-#endif
-}
-
 static int key_search(struct extent_buffer *b, const struct btrfs_key *key,
 		      int level, int *prev_cmp, int *slot)
 {
@@ -2572,7 +2552,6 @@ static int key_search(struct extent_buffer *b, const struct btrfs_key *key,
 		return *prev_cmp;
 	}
 
-	key_search_validate(b, key, level);
 	*slot = 0;
 
 	return 0;
