Commit 14ae60c7 authored by Roger L. Beckermeyer III's avatar Roger L. Beckermeyer III Committed by David Sterba
Browse files

btrfs: update prelim_ref_insert() to use rb helpers 



Update prelim_ref_insert() to use rb_find_add_cached().

There is a special change that the existing prelim_ref_compare() is
called with the first parameter as the existing ref in the rbtree.

But the newer rb_find_add_cached() expects the cmp() function to have
the first parameter as the to-be-added node, thus the new helper
prelim_ref_rb_add_cmp() need to adapt this new order.

Signed-off-by: default avatarRoger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 372484f2

fs/btrfs/backref.c

+39 −40
Original line number Diff line number Diff line
@@ -250,6 +250,21 @@ static int prelim_ref_compare(const struct prelim_ref *ref1, 
	return 0;

}



static int prelim_ref_rb_add_cmp(const struct rb_node *new,

				 const struct rb_node *exist)

{

	const struct prelim_ref *ref_new =

		rb_entry(new, struct prelim_ref, rbnode);

	const struct prelim_ref *ref_exist =

		rb_entry(exist, struct prelim_ref, rbnode);



	/*

	 * prelim_ref_compare() expects the first parameter as the existing one,

	 * different from the rb_find_add_cached() order.

	 */

	return prelim_ref_compare(ref_exist, ref_new);

}



static void update_share_count(struct share_check *sc, int oldcount,

			       int newcount, const struct prelim_ref *newref)

{
@@ -278,25 +293,12 @@ static void prelim_ref_insert(const struct btrfs_fs_info *fs_info, 
			      struct share_check *sc)

{

	struct rb_root_cached *root;

	struct rb_node **p;

	struct rb_node *parent = NULL;

	struct prelim_ref *ref;

	int result;

	bool leftmost = true;

	struct rb_node *exist;



	root = &preftree->root;

	p = &root->rb_root.rb_node;



	while (*p) {

		parent = *p;

		ref = rb_entry(parent, struct prelim_ref, rbnode);

		result = prelim_ref_compare(ref, newref);

		if (result < 0) {

			p = &(*p)->rb_left;

		} else if (result > 0) {

			p = &(*p)->rb_right;

			leftmost = false;

		} else {

	exist = rb_find_add_cached(&newref->rbnode, root, prelim_ref_rb_add_cmp);

	if (exist) {

		struct prelim_ref *ref = rb_entry(exist, struct prelim_ref, rbnode);

		/* Identical refs, merge them and free @newref */

		struct extent_inode_elem *eie = ref->inode_list;
@@ -320,13 +322,10 @@ static void prelim_ref_insert(const struct btrfs_fs_info *fs_info, 
		free_pref(newref);

		return;

	}

	}



	update_share_count(sc, 0, newref->count, newref);

	preftree->count++;

	trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count);

	rb_link_node(&newref->rbnode, parent, p);

	rb_insert_color_cached(&newref->rbnode, root, leftmost);

}



/*