Commit e8b0d724 authored Oct 15, 2013 by Filipe David Borba Manana Committed by Chris Mason Nov 11, 2013

Btrfs: fix btrfs_prev_leaf() previous key computation



If we decrement the key type, we must reset its offset to the largest
possible offset (u64)-1. If we decrement the key's objectid, then we
must reset the key's type and offset to their largest possible values,
(u8)-1 and (u64)-1 respectively. Not doing so can make us miss an
items in the tree.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

parent e93ae26f

fs/btrfs/ctree.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -4827,14 +4827,18 @@ static int btrfs_prev_leaf(struct btrfs_root root, struct btrfs_path path)

		btrfs_item_key_to_cpu(path->nodes[0], &key, 0);

		if (key.offset > 0)
		if (key.offset > 0) {
		key.offset--;
		else if (key.type > 0)
		} else if (key.type > 0) {
		key.type--;
		else if (key.objectid > 0)
		key.offset = (u64)-1;
		} else if (key.objectid > 0) {
		key.objectid--;
		else
		key.type = (u8)-1;
		key.offset = (u64)-1;
		} else {
		return 1;
		}

		btrfs_release_path(path);
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);