1 files changed, 30 insertions, 33 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3014a1a23efd..957230abd827 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -70,20 +70,17 @@ static int block_group_bits(struct btrfs_block_group *cache, u64 bits)
 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
 {
 	struct btrfs_root *root = btrfs_extent_root(fs_info, start);
-	int ret;
 	struct btrfs_key key;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
 
 	key.objectid = start;
-	key.offset = len;
 	key.type = BTRFS_EXTENT_ITEM_KEY;
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	btrfs_free_path(path);
-	return ret;
+	key.offset = len;
+	return btrfs_search_slot(NULL, root, &key, path, 0, 0);
 }
 
 /*
@@ -103,7 +100,7 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 	struct btrfs_root *extent_root;
 	struct btrfs_delayed_ref_head *head;
 	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct btrfs_key key;
 	u64 num_refs;
 	u64 extent_flags;
@@ -125,16 +122,16 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 
 search_again:
 	key.objectid = bytenr;
-	key.offset = offset;
 	if (metadata)
 		key.type = BTRFS_METADATA_ITEM_KEY;
 	else
 		key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = offset;
 
 	extent_root = btrfs_extent_root(fs_info, bytenr);
 	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
 	if (ret < 0)
-		goto out_free;
+		return ret;
 
 	if (ret > 0 && key.type == BTRFS_METADATA_ITEM_KEY) {
 		if (path->slots[0]) {
@@ -159,7 +156,7 @@ search_again:
 			"unexpected extent item size, has %u expect >= %zu",
 				  item_size, sizeof(*ei));
 			btrfs_abort_transaction(trans, ret);
-			goto out_free;
+			return ret;
 		}
 
 		ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@@ -170,7 +167,7 @@ search_again:
 		"unexpected zero reference count for extent item (%llu %u %llu)",
 				  key.objectid, key.type, key.offset);
 			btrfs_abort_transaction(trans, ret);
-			goto out_free;
+			return ret;
 		}
 		extent_flags = btrfs_extent_flags(leaf, ei);
 		owner = btrfs_get_extent_owner_root(fs_info, leaf, path->slots[0]);
@@ -216,8 +213,7 @@ search_again:
 		*flags = extent_flags;
 	if (owning_root)
 		*owning_root = owner;
-out_free:
-	btrfs_free_path(path);
+
 	return ret;
 }
 
@@ -1487,7 +1483,7 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 				  struct btrfs_delayed_ref_node *node,
 				  struct btrfs_delayed_extent_op *extent_op)
 {
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct extent_buffer *leaf;
 	struct btrfs_extent_item *item;
 	struct btrfs_key key;
@@ -1508,7 +1504,7 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 					   node->parent, node->ref_root, owner,
 					   offset, refs_to_add, extent_op);
 	if ((ret < 0 && ret != -EAGAIN) || !ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Ok we had -EAGAIN which means we didn't have space to insert and
@@ -1533,8 +1529,7 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 
 	if (ret)
 		btrfs_abort_transaction(trans, ret);
-out:
-	btrfs_free_path(path);
+
 	return ret;
 }
 
@@ -1631,7 +1626,7 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_root *root;
 	struct btrfs_key key;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct btrfs_extent_item *ei;
 	struct extent_buffer *leaf;
 	u32 item_size;
@@ -1662,7 +1657,7 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
 again:
 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 	if (ret < 0) {
-		goto out;
+		return ret;
 	} else if (ret > 0) {
 		if (metadata) {
 			if (path->slots[0] > 0) {
@@ -1679,8 +1674,8 @@ again:
 				metadata = 0;
 
 				key.objectid = head->bytenr;
-				key.offset = head->num_bytes;
 				key.type = BTRFS_EXTENT_ITEM_KEY;
+				key.offset = head->num_bytes;
 				goto again;
 			}
 		} else {
@@ -1688,7 +1683,7 @@ again:
 			btrfs_err(fs_info,
 		  "missing extent item for extent %llu num_bytes %llu level %d",
 				  head->bytenr, head->num_bytes, head->level);
-			goto out;
+			return ret;
 		}
 	}
 
@@ -1701,13 +1696,12 @@ again:
 			  "unexpected extent item size, has %u expect >= %zu",
 			  item_size, sizeof(*ei));
 		btrfs_abort_transaction(trans, ret);
-		goto out;
+		return ret;
 	}
 
 	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 	__run_delayed_extent_op(extent_op, leaf, ei);
-out:
-	btrfs_free_path(path);
+
 	return ret;
 }
 
@@ -2348,8 +2342,8 @@ static noinline int check_committed_ref(struct btrfs_inode *inode,
 	int ret;
 
 	key.objectid = bytenr;
-	key.offset = (u64)-1;
 	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = (u64)-1;
 
 	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
 	if (ret < 0)
@@ -2874,7 +2868,15 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
 						   block_group->length,
 						   &trimmed);
 
+		/*
+		 * Not strictly necessary to lock, as the block_group should be
+		 * read-only from btrfs_delete_unused_bgs().
+		 */
+		ASSERT(block_group->ro);
+		spin_lock(&fs_info->unused_bgs_lock);
 		list_del_init(&block_group->bg_list);
+		spin_unlock(&fs_info->unused_bgs_lock);
+
 		btrfs_unfreeze_block_group(block_group);
 		btrfs_put_block_group(block_group);
 
@@ -5465,7 +5467,7 @@ static int check_ref_exists(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct btrfs_delayed_ref_head *head;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct btrfs_extent_inline_ref *iref;
 	int ret;
 	bool exists = false;
@@ -5482,7 +5484,6 @@ again:
 		 * If we get 0 then we found our reference, return 1, else
 		 * return the error if it's not -ENOENT;
 		 */
-		btrfs_free_path(path);
 		return (ret < 0 ) ? ret : 1;
 	}
 
@@ -5517,7 +5518,6 @@ again:
 	mutex_unlock(&head->mutex);
 out:
 	spin_unlock(&delayed_refs->lock);
-	btrfs_free_path(path);
 	return exists ? 1 : 0;
 }
 
@@ -6285,7 +6285,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 			struct extent_buffer *parent)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct walk_control *wc;
 	int level;
 	int parent_level;
@@ -6298,10 +6298,8 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 		return -ENOMEM;
 
 	wc = kzalloc(sizeof(*wc), GFP_NOFS);
-	if (!wc) {
-		btrfs_free_path(path);
+	if (!wc)
 		return -ENOMEM;
-	}
 
 	btrfs_assert_tree_write_locked(parent);
 	parent_level = btrfs_header_level(parent);
@@ -6338,7 +6336,6 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	}
 
 	kfree(wc);
-	btrfs_free_path(path);
 	return ret;
 }