Commit b908c334 authored by David Sterba's avatar David Sterba
Browse files

btrfs: move root node locking helpers to locking.c 



The helpers are related to locking so move them there, update comments.

Reviewed-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 00246528

fs/btrfs/ctree.c

+0 −38
Original line number Diff line number Diff line
@@ -143,44 +143,6 @@ struct extent_buffer *btrfs_root_node(struct btrfs_root *root) 
	return eb;

}



/* loop around taking references on and locking the root node of the

 * tree until you end up with a lock on the root.  A locked buffer

 * is returned, with a reference held.

 */

struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)

{

	struct extent_buffer *eb;



	while (1) {

		eb = btrfs_root_node(root);

		btrfs_tree_lock(eb);

		if (eb == root->node)

			break;

		btrfs_tree_unlock(eb);

		free_extent_buffer(eb);

	}

	return eb;

}



/* loop around taking references on and locking the root node of the

 * tree until you end up with a lock on the root.  A locked buffer

 * is returned, with a reference held.

 */

struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)

{

	struct extent_buffer *eb;



	while (1) {

		eb = btrfs_root_node(root);

		btrfs_tree_read_lock(eb);

		if (eb == root->node)

			break;

		btrfs_tree_read_unlock(eb);

		free_extent_buffer(eb);

	}

	return eb;

}



/* cowonly root (everything not a reference counted cow subvolume), just get

 * put onto a simple dirty list.  transaction.c walks this to make sure they

 * get properly updated on disk.

fs/btrfs/locking.c

+42 −0
Original line number Diff line number Diff line
@@ -523,3 +523,45 @@ void btrfs_unlock_up_safe(struct btrfs_path *path, int level) 
		path->locks[i] = 0;

	}

}



/*

 * Loop around taking references on and locking the root node of the tree until

 * we end up with a lock on the root node.

 *

 * Return: root extent buffer with write lock held

 */

struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)

{

	struct extent_buffer *eb;



	while (1) {

		eb = btrfs_root_node(root);

		btrfs_tree_lock(eb);

		if (eb == root->node)

			break;

		btrfs_tree_unlock(eb);

		free_extent_buffer(eb);

	}

	return eb;

}



/*

 * Loop around taking references on and locking the root node of the tree until

 * we end up with a lock on the root node.

 *

 * Return: root extent buffer with read lock held

 */

struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)

{

	struct extent_buffer *eb;



	while (1) {

		eb = btrfs_root_node(root);

		btrfs_tree_read_lock(eb);

		if (eb == root->node)

			break;

		btrfs_tree_read_unlock(eb);

		free_extent_buffer(eb);

	}

	return eb;

}