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Commit 4d081c41 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: change btrfs_del_leaf to drop locks earlier 



btrfs_del_leaf does two things.  First it removes the pointer in the
parent, and then it frees the block that has the leaf.  It has the
parent node locked for both operations.

But, it only needs the parent locked while it is deleting the pointer.
After that it can safely free the block without the parent locked.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 06d9a8d7

fs/btrfs/ctree.c

+9 −2
Original line number Diff line number Diff line
@@ -3630,15 +3630,22 @@ noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, 
{

	int ret;

	u64 root_gen = btrfs_header_generation(path->nodes[1]);

	u64 parent_start = path->nodes[1]->start;

	u64 parent_owner = btrfs_header_owner(path->nodes[1]);



	ret = del_ptr(trans, root, path, 1, path->slots[1]);

	if (ret)

		return ret;



	/*

	 * btrfs_free_extent is expensive, we want to make sure we

	 * aren't holding any locks when we call it

	 */

	btrfs_unlock_up_safe(path, 0);



	ret = btrfs_free_extent(trans, root, bytenr,

				btrfs_level_size(root, 0),

				path->nodes[1]->start,

				btrfs_header_owner(path->nodes[1]),

				parent_start, parent_owner,

				root_gen, 0, 1);

	return ret;

}