From: Josef Bacik <josef@toxicpanda.com>
Date: Thu, 20 Jun 2019 15:37:52 -0400
Subject: btrfs: make caching_thread use btrfs_find_next_key
Git-commit: 6a9fb468f1152d6254f49fee6ac28c3cfa3367e5
Patch-mainline: v5.4-rc1
References: bsc#1165949

extent-tree.c has a find_next_key that just walks up the path to find
the next key, but it is used for both the caching stuff and the snapshot
delete stuff.  The snapshot deletion stuff is special so it can't really
use btrfs_find_next_key, but the caching thread stuff can.  We just need
to fix btrfs_find_next_key to deal with ->skip_locking and then it works
exactly the same as the private find_next_key helper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/ctree.c       | 4 ++--
 fs/btrfs/extent-tree.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9d1d0a926cb0..f8dc582db690 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -5623,7 +5623,7 @@ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
 	int slot;
 	struct extent_buffer *c;
 
-	WARN_ON(!path->keep_locks);
+	WARN_ON(!path->keep_locks && !path->skip_locking);
 	while (level < BTRFS_MAX_LEVEL) {
 		if (!path->nodes[level])
 			return 1;
@@ -5639,7 +5639,7 @@ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
 			    !path->nodes[level + 1])
 				return 1;
 
-			if (path->locks[level + 1]) {
+			if (path->locks[level + 1] || path->skip_locking) {
 				level++;
 				continue;
 			}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 6cae152a4812..3348f9a4e15c 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -331,7 +331,7 @@ static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
 		if (path->slots[0] < nritems) {
 			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 		} else {
-			ret = find_next_key(path, 0, &key);
+			ret = btrfs_find_next_key(extent_root, path, &key, 0, 0);
 			if (ret)
 				break;