Btrfs: Add inode item and backref in one insert, reducing cpu usage

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/ctree.c

@@ -2332,27 +2332,34 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
  * Given a key and some data, insert an item into the tree.
  * This does all the path init required, making room in the tree if needed.
  */
-int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 data_size)
+			    struct btrfs_key *cpu_key, u32 *data_size,
+			    int nr)
 {
 	struct extent_buffer *leaf;
 	struct btrfs_item *item;
 	int ret = 0;
 	int slot;
 	int slot_orig;
+	int i;
 	u32 nritems;
+	u32 total_size = 0;
+	u32 total_data = 0;
 	unsigned int data_end;
 	struct btrfs_disk_key disk_key;
 
-	btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+	for (i = 0; i < nr; i++) {
+		total_data += data_size[i];
+	}
 
 	/* create a root if there isn't one */
 	if (!root->node)
 		BUG();
 
-	ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
+	total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
+	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
 	if (ret == 0) {
 		return -EEXIST;
 	}
@@ -2366,10 +2373,10 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 	data_end = leaf_data_end(root, leaf);
 
 	if (btrfs_leaf_free_space(root, leaf) <
-	    sizeof(struct btrfs_item) + data_size) {
+	    sizeof(struct btrfs_item) + total_size) {
 		btrfs_print_leaf(root, leaf);
 		printk("not enough freespace need %u have %d\n",
-		       data_size, btrfs_leaf_free_space(root, leaf));
+		       total_size, btrfs_leaf_free_space(root, leaf));
 		BUG();
 	}
 
@@ -2404,7 +2411,7 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 			}
 
 			ioff = btrfs_item_offset(leaf, item);
-			btrfs_set_item_offset(leaf, item, ioff - data_size);
+			btrfs_set_item_offset(leaf, item, ioff - total_data);
 		}
 		if (leaf->map_token) {
 			unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
@@ -2412,23 +2419,27 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 		}
 
 		/* shift the items */
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
+		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
 			      btrfs_item_nr_offset(slot),
 			      (nritems - slot) * sizeof(struct btrfs_item));
 
 		/* shift the data */
 		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end - data_size, btrfs_leaf_data(leaf) +
+			      data_end - total_data, btrfs_leaf_data(leaf) +
 			      data_end, old_data - data_end);
 		data_end = old_data;
 	}
 
 	/* setup the item for the new data */
-	btrfs_set_item_key(leaf, &disk_key, slot);
-	item = btrfs_item_nr(leaf, slot);
-	btrfs_set_item_offset(leaf, item, data_end - data_size);
-	btrfs_set_item_size(leaf, item, data_size);
-	btrfs_set_header_nritems(leaf, nritems + 1);
+	for (i = 0; i < nr; i++) {
+		btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+		btrfs_set_item_key(leaf, &disk_key, slot + i);
+		item = btrfs_item_nr(leaf, slot + i);
+		btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+		data_end -= data_size[i];
+		btrfs_set_item_size(leaf, item, data_size[i]);
+	}
+	btrfs_set_header_nritems(leaf, nritems + nr);
 	btrfs_mark_buffer_dirty(leaf);
 
 	ret = 0;

fs/btrfs/ctree.h

@@ -1050,9 +1050,20 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_key *key, void *data, u32 data_size);
-int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			    *root, struct btrfs_path *path, struct btrfs_key
-			    *cpu_key, u32 data_size);
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root,
+			     struct btrfs_path *path,
+			     struct btrfs_key *cpu_key, u32 *data_size, int nr);
+
+static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct btrfs_path *path,
+					  struct btrfs_key *key,
+					  u32 data_size)
+{
+	return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
+}
+
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);

fs/btrfs/inode.c

@@ -1500,6 +1500,8 @@ void btrfs_dirty_inode(struct inode *inode)
 
 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
+				     const char *name, int name_len,
+				     u64 ref_objectid,
 				     u64 objectid,
 				     struct btrfs_block_group_cache *group,
 				     int mode)
@@ -1508,6 +1510,10 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_item *inode_item;
 	struct btrfs_key *location;
 	struct btrfs_path *path;
+	struct btrfs_inode_ref *ref;
+	struct btrfs_key key[2];
+	u32 sizes[2];
+	unsigned long ptr;
 	int ret;
 	int owner;
 
@@ -1530,10 +1536,25 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	group = btrfs_find_block_group(root, group, 0, 0, owner);
 	BTRFS_I(inode)->block_group = group;
 	BTRFS_I(inode)->flags = 0;
-	ret = btrfs_insert_empty_inode(trans, root, path, objectid);
-	if (ret)
+
+	key[0].objectid = objectid;
+	btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
+	key[0].offset = 0;
+
+	key[1].objectid = objectid;
+	btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
+	key[1].offset = ref_objectid;
+
+	sizes[0] = sizeof(struct btrfs_inode_item);
+	sizes[1] = name_len + sizeof(*ref);
+
+	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
+	if (ret != 0)
 		goto fail;
 
+	if (objectid > root->highest_inode)
+		root->highest_inode = objectid;
+
 	inode->i_uid = current->fsuid;
 	inode->i_gid = current->fsgid;
 	inode->i_mode = mode;
@@ -1543,6 +1564,13 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				  struct btrfs_inode_item);
 	fill_inode_item(path->nodes[0], inode_item, inode);
+
+	ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+			     struct btrfs_inode_ref);
+	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+	ptr = (unsigned long)(ref + 1);
+	write_extent_buffer(path->nodes[0], name, ptr, name_len);
+
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	btrfs_free_path(path);
 
@@ -1564,7 +1592,8 @@ static inline u8 btrfs_inode_type(struct inode *inode)
 }
 
 static int btrfs_add_link(struct btrfs_trans_handle *trans,
-			    struct dentry *dentry, struct inode *inode)
+			    struct dentry *dentry, struct inode *inode,
+			    int add_backref)
 {
 	int ret;
 	struct btrfs_key key;
@@ -1580,11 +1609,13 @@ static int btrfs_add_link(struct btrfs_trans_handle *trans,
 				    dentry->d_parent->d_inode->i_ino,
 				    &key, btrfs_inode_type(inode));
 	if (ret == 0) {
-		ret = btrfs_insert_inode_ref(trans, root,
-				     dentry->d_name.name,
-				     dentry->d_name.len,
-				     inode->i_ino,
-				     dentry->d_parent->d_inode->i_ino);
+		if (add_backref) {
+			ret = btrfs_insert_inode_ref(trans, root,
+					     dentry->d_name.name,
+					     dentry->d_name.len,
+					     inode->i_ino,
+					     dentry->d_parent->d_inode->i_ino);
+		}
 		parent_inode = dentry->d_parent->d_inode;
 		parent_inode->i_size += dentry->d_name.len * 2;
 		parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
@@ -1595,9 +1626,10 @@ static int btrfs_add_link(struct btrfs_trans_handle *trans,
 }
 
 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
-			    struct dentry *dentry, struct inode *inode)
+			    struct dentry *dentry, struct inode *inode,
+			    int backref)
 {
-	int err = btrfs_add_link(trans, dentry, inode);
+	int err = btrfs_add_link(trans, dentry, inode, backref);
 	if (!err) {
 		d_instantiate(dentry, inode);
 		return 0;
@@ -1635,14 +1667,16 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 		goto out_unlock;
 	}
 
-	inode = btrfs_new_inode(trans, root, objectid,
+	inode = btrfs_new_inode(trans, root, dentry->d_name.name,
+				dentry->d_name.len,
+				dentry->d_parent->d_inode->i_ino, objectid,
 				BTRFS_I(dir)->block_group, mode);
 	err = PTR_ERR(inode);
 	if (IS_ERR(inode))
 		goto out_unlock;
 
 	btrfs_set_trans_block_group(trans, inode);
-	err = btrfs_add_nondir(trans, dentry, inode);
+	err = btrfs_add_nondir(trans, dentry, inode, 0);
 	if (err)
 		drop_inode = 1;
 	else {
@@ -1692,14 +1726,16 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 		goto out_unlock;
 	}
 
-	inode = btrfs_new_inode(trans, root, objectid,
-				BTRFS_I(dir)->block_group, mode);
+	inode = btrfs_new_inode(trans, root, dentry->d_name.name,
+				dentry->d_name.len,
+				dentry->d_parent->d_inode->i_ino,
+				objectid, BTRFS_I(dir)->block_group, mode);
 	err = PTR_ERR(inode);
 	if (IS_ERR(inode))
 		goto out_unlock;
 
 	btrfs_set_trans_block_group(trans, inode);
-	err = btrfs_add_nondir(trans, dentry, inode);
+	err = btrfs_add_nondir(trans, dentry, inode, 0);
 	if (err)
 		drop_inode = 1;
 	else {
@@ -1755,7 +1791,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 
 	btrfs_set_trans_block_group(trans, dir);
 	atomic_inc(&inode->i_count);
-	err = btrfs_add_nondir(trans, dentry, inode);
+	err = btrfs_add_nondir(trans, dentry, inode, 1);
 
 	if (err)
 		drop_inode = 1;
@@ -1810,7 +1846,9 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 		goto out_unlock;
 	}
 
-	inode = btrfs_new_inode(trans, root, objectid,
+	inode = btrfs_new_inode(trans, root, dentry->d_name.name,
+				dentry->d_name.len,
+				dentry->d_parent->d_inode->i_ino, objectid,
 				BTRFS_I(dir)->block_group, S_IFDIR | mode);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
@@ -1827,7 +1865,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	if (err)
 		goto out_fail;
 
-	err = btrfs_add_link(trans, dentry, inode);
+	err = btrfs_add_link(trans, dentry, inode, 0);
 	if (err)
 		goto out_fail;
 
@@ -2320,7 +2358,8 @@ static int noinline create_subvol(struct btrfs_root *root, char *name,
 	trans = btrfs_start_transaction(new_root, 1);
 	BUG_ON(!trans);
 
-	inode = btrfs_new_inode(trans, new_root, new_dirid,
+	inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
+				new_dirid,
 				BTRFS_I(dir)->block_group, S_IFDIR | 0700);
 	if (IS_ERR(inode))
 		goto fail;
@@ -2817,7 +2856,7 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
 		if (ret)
 			goto out_fail;
 	}
-	ret = btrfs_add_link(trans, new_dentry, old_inode);
+	ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
 	if (ret)
 		goto out_fail;
 
@@ -2865,14 +2904,16 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 		goto out_unlock;
 	}
 
-	inode = btrfs_new_inode(trans, root, objectid,
+	inode = btrfs_new_inode(trans, root, dentry->d_name.name,
+				dentry->d_name.len,
+				dentry->d_parent->d_inode->i_ino, objectid,
 				BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
 	err = PTR_ERR(inode);
 	if (IS_ERR(inode))
 		goto out_unlock;
 
 	btrfs_set_trans_block_group(trans, inode);
-	err = btrfs_add_nondir(trans, dentry, inode);
+	err = btrfs_add_nondir(trans, dentry, inode, 0);
 	if (err)
 		drop_inode = 1;
 	else {