Commit 562d4254 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: factor out eb uptodate check from do_walk_down() 



do_walk_down() already has a bunch of things going on, and there's a bit
of code related to reading in the next eb if we decide we need it.  Move
this code off into it's own helper to clean up do_walk_down() a little
bit.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 7fcee18d

fs/btrfs/extent-tree.c

+45 −20
Original line number Diff line number Diff line
@@ -5409,6 +5409,48 @@ static int check_ref_exists(struct btrfs_trans_handle *trans, 
	return 1;

}



/*

 * We may not have an uptodate block, so if we are going to walk down into this

 * block we need to drop the lock, read it off of the disk, re-lock it and

 * return to continue dropping the snapshot.

 */

static int check_next_block_uptodate(struct btrfs_trans_handle *trans,

				     struct btrfs_root *root,

				     struct btrfs_path *path,

				     struct walk_control *wc,

				     struct extent_buffer *next)

{

	struct btrfs_tree_parent_check check = { 0 };

	u64 generation;

	int level = wc->level;

	int ret;



	btrfs_assert_tree_write_locked(next);



	generation = btrfs_node_ptr_generation(path->nodes[level], path->slots[level]);



	if (btrfs_buffer_uptodate(next, generation, 0))

		return 0;



	check.level = level - 1;

	check.transid = generation;

	check.owner_root = btrfs_root_id(root);

	check.has_first_key = true;

	btrfs_node_key_to_cpu(path->nodes[level], &check.first_key, path->slots[level]);



	btrfs_tree_unlock(next);

	if (level == 1)

		reada_walk_down(trans, root, wc, path);

	ret = btrfs_read_extent_buffer(next, &check);

	if (ret) {

		free_extent_buffer(next);

		return ret;

	}

	btrfs_tree_lock(next);

	wc->lookup_info = 1;

	return 0;

}



/*

 * helper to process tree block pointer.

 *
@@ -5431,7 +5473,6 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
	u64 bytenr;

	u64 generation;

	u64 owner_root = 0;

	struct btrfs_tree_parent_check check = { 0 };

	struct btrfs_key key;

	struct extent_buffer *next;

	int level = wc->level;
@@ -5453,13 +5494,6 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 


	bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);



	check.level = level - 1;

	check.transid = generation;

	check.owner_root = btrfs_root_id(root);

	check.has_first_key = true;

	btrfs_node_key_to_cpu(path->nodes[level], &check.first_key,

			      path->slots[level]);



	next = btrfs_find_create_tree_block(fs_info, bytenr, btrfs_root_id(root),

					    level - 1);

	if (IS_ERR(next))
@@ -5507,18 +5541,9 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
			goto skip;

	}



	if (!btrfs_buffer_uptodate(next, generation, 0)) {

		btrfs_tree_unlock(next);

		if (level == 1)

			reada_walk_down(trans, root, wc, path);

		ret = btrfs_read_extent_buffer(next, &check);

		if (ret) {

			free_extent_buffer(next);

	ret = check_next_block_uptodate(trans, root, path, wc, next);

	if (ret)

		return ret;

		}

		btrfs_tree_lock(next);

		wc->lookup_info = 1;

	}



	level--;

	ASSERT(level == btrfs_header_level(next));