btrfs: eliminate total_size parameter from setup_items_for_insert

The value of this argument can be derived from the total_data as it's
simply the value of the data size + size of btrfs_items being touched.
Move the parameter calculation inside the function. This results in a
simpler interface and also a minor size reduction:

./scripts/bloat-o-meter ctree.original fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-34 (-34)
Function                                     old     new   delta
btrfs_duplicate_item                         260     259      -1
setup_items_for_insert                      1200    1190     -10
btrfs_insert_empty_items                     177     154     -23

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

@@ -4580,9 +4580,7 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
 		return ret;
 
 	path->slots[0]++;
-	setup_items_for_insert(root, path, new_key, &item_size,
+	setup_items_for_insert(root, path, new_key, &item_size, item_size, 1);
-			       item_size, item_size +
-			       sizeof(struct btrfs_item), 1);
 	leaf = path->nodes[0];
 	memcpy_extent_buffer(leaf,
 			     btrfs_item_ptr_offset(leaf, path->slots[0]),
@@ -4762,7 +4760,7 @@ void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
  */
 void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
 			    const struct btrfs_key *cpu_key, u32 *data_size,
-			    u32 total_data, u32 total_size, int nr)
+			    u32 total_data, int nr)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_item *item;
@@ -4773,6 +4771,7 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
 	struct extent_buffer *leaf;
 	int slot;
 	struct btrfs_map_token token;
+	const u32 total_size = total_data + (nr * sizeof(struct btrfs_item));
 
 	if (path->slots[0] == 0) {
 		btrfs_cpu_key_to_disk(&disk_key, cpu_key);
@@ -4875,8 +4874,7 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 	slot = path->slots[0];
 	BUG_ON(slot < 0);
 
-	setup_items_for_insert(root, path, cpu_key, data_size,
+	setup_items_for_insert(root, path, cpu_key, data_size, total_data, nr);
-			       total_data, total_size, nr);
 	return 0;
 }
 

fs/btrfs/ctree.h

@@ -2744,7 +2744,7 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 
 void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
 			    const struct btrfs_key *cpu_key, u32 *data_size,
-			    u32 total_data, u32 total_size, int nr);
+			    u32 total_data, int nr);
 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,

fs/btrfs/delayed-inode.c

@@ -768,8 +768,8 @@ static int btrfs_batch_insert_items(struct btrfs_root *root,
 	}
 
 	/* insert the keys of the items */
-	setup_items_for_insert(root, path, keys, data_size,
+	setup_items_for_insert(root, path, keys, data_size, total_data_size,
-			       total_data_size, total_size, nitems);
+			       nitems);
 
 	/* insert the dir index items */
 	slot = path->slots[0];

fs/btrfs/file.c

@@ -1057,10 +1057,7 @@ delete_extent_item:
 			if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
 				path->slots[0]++;
 		}
-		setup_items_for_insert(root, path, &key,
+		setup_items_for_insert(root, path, &key, &extent_item_size,
-				       &extent_item_size,
-				       extent_item_size,
-				       sizeof(struct btrfs_item) +
 				       extent_item_size, 1);
 		*key_inserted = 1;
 	}

fs/btrfs/tests/extent-buffer-tests.c

@@ -60,8 +60,7 @@ static int test_btrfs_split_item(u32 sectorsize, u32 nodesize)
 	key.type = BTRFS_EXTENT_CSUM_KEY;
 	key.offset = 0;
 
-	setup_items_for_insert(root, path, &key, &value_len, value_len,
+	setup_items_for_insert(root, path, &key, &value_len, value_len, 1);
-			       value_len + sizeof(struct btrfs_item), 1);
 	item = btrfs_item_nr(0);
 	write_extent_buffer(eb, value, btrfs_item_ptr_offset(eb, 0),
 			    value_len);

fs/btrfs/tests/inode-tests.c

@@ -33,8 +33,7 @@ static void insert_extent(struct btrfs_root *root, u64 start, u64 len,
 	key.type = BTRFS_EXTENT_DATA_KEY;
 	key.offset = start;
 
-	setup_items_for_insert(root, &path, &key, &value_len, value_len,
+	setup_items_for_insert(root, &path, &key, &value_len, value_len, 1);
-			       value_len + sizeof(struct btrfs_item), 1);
 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 	btrfs_set_file_extent_generation(leaf, fi, 1);
 	btrfs_set_file_extent_type(leaf, fi, type);
@@ -64,8 +63,7 @@ static void insert_inode_item_key(struct btrfs_root *root)
 	key.type = BTRFS_INODE_ITEM_KEY;
 	key.offset = 0;
 
-	setup_items_for_insert(root, &path, &key, &value_len, value_len,
+	setup_items_for_insert(root, &path, &key, &value_len, value_len, 1);
-			       value_len + sizeof(struct btrfs_item), 1);
 }
 
 /*