Commit 253002f2 authored Feb 20, 2019 by Filipe Manana Committed by David Sterba Feb 25, 2019

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



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 581c1760 ("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>

parent cbca7d59

fs/btrfs/ctree.c

+0 −21

Original line number	Diff line number	Diff line
		@@ -2544,26 +2544,6 @@ done:
		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;

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