1 files changed, 18 insertions, 14 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index b3268f4ea5f3..02d7d7b2563b 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -544,7 +544,18 @@ static int resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 	int level = ref->level;
 	struct btrfs_key search_key = ref->key_for_search;
 
-	root = btrfs_get_fs_root(fs_info, ref->root_id, false);
+	/*
+	 * If we're search_commit_root we could possibly be holding locks on
+	 * other tree nodes.  This happens when qgroups does backref walks when
+	 * adding new delayed refs.  To deal with this we need to look in cache
+	 * for the root, and if we don't find it then we need to search the
+	 * tree_root's commit root, thus the btrfs_get_fs_root_commit_root usage
+	 * here.
+	 */
+	if (path->search_commit_root)
+		root = btrfs_get_fs_root_commit_root(fs_info, path, ref->root_id);
+	else
+		root = btrfs_get_fs_root(fs_info, ref->root_id, false);
 	if (IS_ERR(root)) {
 		ret = PTR_ERR(root);
 		goto out_free;
@@ -772,8 +783,8 @@ static int add_missing_keys(struct btrfs_fs_info *fs_info,
 		BUG_ON(ref->key_for_search.type);
 		BUG_ON(!ref->wanted_disk_byte);
 
-		eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0,
-				     ref->level - 1, NULL);
+		eb = read_tree_block(fs_info, ref->wanted_disk_byte,
+				     ref->root_id, 0, ref->level - 1, NULL);
 		if (IS_ERR(eb)) {
 			free_pref(ref);
 			return PTR_ERR(eb);
@@ -1320,7 +1331,7 @@ again:
 				struct extent_buffer *eb;
 
 				eb = read_tree_block(fs_info, ref->parent, 0,
-						     ref->level, NULL);
+						     0, ref->level, NULL);
 				if (IS_ERR(eb)) {
 					ret = PTR_ERR(eb);
 					goto out;
@@ -1330,14 +1341,12 @@ again:
 					goto out;
 				}
 
-				if (!path->skip_locking) {
+				if (!path->skip_locking)
 					btrfs_tree_read_lock(eb);
-					btrfs_set_lock_blocking_read(eb);
-				}
 				ret = find_extent_in_eb(eb, bytenr,
 							*extent_item_pos, &eie, ignore_offset);
 				if (!path->skip_locking)
-					btrfs_tree_read_unlock_blocking(eb);
+					btrfs_tree_read_unlock(eb);
 				free_extent_buffer(eb);
 				if (ret < 0)
 					goto out;
@@ -1660,13 +1669,11 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 	s64 bytes_left = ((s64)size) - 1;
 	struct extent_buffer *eb = eb_in;
 	struct btrfs_key found_key;
-	int leave_spinning = path->leave_spinning;
 	struct btrfs_inode_ref *iref;
 
 	if (bytes_left >= 0)
 		dest[bytes_left] = '\0';
 
-	path->leave_spinning = 1;
 	while (1) {
 		bytes_left -= name_len;
 		if (bytes_left >= 0)
@@ -1674,7 +1681,7 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 					   name_off, name_len);
 		if (eb != eb_in) {
 			if (!path->skip_locking)
-				btrfs_tree_read_unlock_blocking(eb);
+				btrfs_tree_read_unlock(eb);
 			free_extent_buffer(eb);
 		}
 		ret = btrfs_find_item(fs_root, path, parent, 0,
@@ -1694,8 +1701,6 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 		eb = path->nodes[0];
 		/* make sure we can use eb after releasing the path */
 		if (eb != eb_in) {
-			if (!path->skip_locking)
-				btrfs_set_lock_blocking_read(eb);
 			path->nodes[0] = NULL;
 			path->locks[0] = 0;
 		}
@@ -1712,7 +1717,6 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 	}
 
 	btrfs_release_path(path);
-	path->leave_spinning = leave_spinning;
 
 	if (ret)
 		return ERR_PTR(ret);