Btrfs: remove duplicated ino cache's inode lookup

We're doing a unnecessary extra lookup of the ino cache's
inode when we already have it (and holding a reference)
during the process of saving the ino cache contents to disk.
Therefore remove this extra lookup.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

fs/btrfs/free-space-cache.c

@@ -2967,19 +2967,15 @@ out:
 
 int btrfs_write_out_ino_cache(struct btrfs_root *root,
 			      struct btrfs_trans_handle *trans,
-			      struct btrfs_path *path)
+			      struct btrfs_path *path,
+			      struct inode *inode)
 {
 	struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
-	struct inode *inode;
 	int ret;
 
 	if (!btrfs_test_opt(root, INODE_MAP_CACHE))
 		return 0;
 
-	inode = lookup_free_ino_inode(root, path);
-	if (IS_ERR(inode))
-		return 0;
-
 	ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
 	if (ret) {
 		btrfs_delalloc_release_metadata(inode, inode->i_size);
@@ -2990,7 +2986,6 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
 #endif
 	}
 
-	iput(inode);
 	return ret;
 }
 

fs/btrfs/free-space-cache.h

@@ -76,7 +76,8 @@ int load_free_ino_cache(struct btrfs_fs_info *fs_info,
 			struct btrfs_root *root);
 int btrfs_write_out_ino_cache(struct btrfs_root *root,
 			      struct btrfs_trans_handle *trans,
-			      struct btrfs_path *path);
+			      struct btrfs_path *path,
+			      struct inode *inode);
 
 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group);
 int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,

fs/btrfs/inode-map.c

@@ -503,7 +503,7 @@ again:
 	}
 	btrfs_free_reserved_data_space(inode, prealloc);
 
-	ret = btrfs_write_out_ino_cache(root, trans, path);
+	ret = btrfs_write_out_ino_cache(root, trans, path, inode);
 out_put:
 	iput(inode);
 out_release: