1 files changed, 52 insertions, 5 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b394ba4737e4..140fe98f5e38 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2897,16 +2897,56 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 	return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
+/*
+ * Describes a batch of items to insert in a btree. This is used by
+ * btrfs_insert_empty_items() and setup_items_for_insert().
+ */
+struct btrfs_item_batch {
+	/*
+	 * Pointer to an array containing the keys of the items to insert (in
+	 * sorted order).
+	 */
+	const struct btrfs_key *keys;
+	/* Pointer to an array containing the data size for each item to insert. */
+	const u32 *data_sizes;
+	/*
+	 * The sum of data sizes for all items. The caller can compute this while
+	 * setting up the data_sizes array, so it ends up being more efficient
+	 * than having btrfs_insert_empty_items() or setup_item_for_insert()
+	 * doing it, as it would avoid an extra loop over a potentially large
+	 * array, and in the case of setup_item_for_insert(), we would be doing
+	 * it while holding a write lock on a leaf and often on upper level nodes
+	 * too, unnecessarily increasing the size of a critical section.
+	 */
+	u32 total_data_size;
+	/* Size of the keys and data_sizes arrays (number of items in the batch). */
+	int nr;
+};
+
 void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
-			    const struct btrfs_key *cpu_key, u32 *data_size,
-			    int nr);
+			    const struct btrfs_item_batch *batch);
+
+static inline void setup_item_for_insert(struct btrfs_root *root,
+					 struct btrfs_path *path,
+					 const struct btrfs_key *key,
+					 u32 data_size)
+{
+	struct btrfs_item_batch batch;
+
+	batch.keys = key;
+	batch.data_sizes = &data_size;
+	batch.total_data_size = data_size;
+	batch.nr = 1;
+
+	setup_items_for_insert(root, path, &batch);
+}
+
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		      const struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path,
-			     const struct btrfs_key *cpu_key, u32 *data_size,
-			     int nr);
+			     const struct btrfs_item_batch *batch);
 
 static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
@@ -2914,7 +2954,14 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 					  const struct btrfs_key *key,
 					  u32 data_size)
 {
-	return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
+	struct btrfs_item_batch batch;
+
+	batch.keys = key;
+	batch.data_sizes = &data_size;
+	batch.total_data_size = data_size;
+	batch.nr = 1;
+
+	return btrfs_insert_empty_items(trans, root, path, &batch);
 }
 
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);