btrfs: declare free_ipath() via DEFINE_FREE()

The free_ipath() function was being used as a cleanup function
everywhere. Declare it via DEFINE_FREE() so we can use this function
with the __free() helper.

The name has also been adjusted so it's closer to the type's name.

Signed-off-by: Miquel Sabaté Solà <[e-mail]>
Reviewed-by: David Sterba <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/backref.c

···
  * allocates space to return multiple file system paths for an inode.
  * total_bytes to allocate are passed, note that space usable for actual path
  * information will be total_bytes - sizeof(struct inode_fs_paths).
- * the returned pointer must be freed with free_ipath() in the end.
+ * the returned pointer must be freed with __free_inode_fs_paths() in the end.
  */
 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
 					struct btrfs_path *path)
···
 	ifp->fs_root = fs_root;
 
 	return ifp;
-}
-
-void free_ipath(struct inode_fs_paths *ipath)
-{
-	if (!ipath)
-		return;
-	kvfree(ipath->fspath);
-	kfree(ipath);
 }
 
 struct btrfs_backref_iter *btrfs_backref_iter_alloc(struct btrfs_fs_info *fs_info)

fs/btrfs/backref.h

···
 struct btrfs_data_container *init_data_container(u32 total_bytes);
 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
 					struct btrfs_path *path);
-void free_ipath(struct inode_fs_paths *ipath);
+
+DEFINE_FREE(inode_fs_paths, struct inode_fs_paths *,
+	if (_T) {
+		kvfree(_T->fspath);
+		kfree(_T);
+	})
 
 int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
 			  u64 start_off, struct btrfs_path *path,

fs/btrfs/inode.c

···
 	struct btrfs_fs_info *fs_info = warn->fs_info;
 	struct extent_buffer *eb;
 	struct btrfs_inode_item *inode_item;
-	struct inode_fs_paths *ipath = NULL;
+	struct inode_fs_paths *ipath __free(inode_fs_paths) = NULL;
 	struct btrfs_root *local_root;
 	struct btrfs_key key;
 	unsigned int nofs_flag;
···
 	}
 
 	btrfs_put_root(local_root);
-	free_ipath(ipath);
 	return 0;
 
 err:
···
 "checksum error at logical %llu mirror %u root %llu inode %llu offset %llu, path resolving failed with ret=%d",
 		   warn->logical, warn->mirror_num, root, inum, offset, ret);
 
-	free_ipath(ipath);
 	return ret;
 }
 

fs/btrfs/ioctl.c

···
 	u64 rel_ptr;
 	int size;
 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
-	struct inode_fs_paths *ipath = NULL;
+	struct inode_fs_paths *ipath __free(inode_fs_paths) = NULL;
 	struct btrfs_path *path;
 
 	if (!capable(CAP_DAC_READ_SEARCH))
···
 
 out:
 	btrfs_free_path(path);
-	free_ipath(ipath);
 	kfree(ipa);
 
 	return ret;

fs/btrfs/scrub.c

···
 	struct btrfs_inode_item *inode_item;
 	struct scrub_warning *swarn = warn_ctx;
 	struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
-	struct inode_fs_paths *ipath = NULL;
+	struct inode_fs_paths *ipath __free(inode_fs_paths) = NULL;
 	struct btrfs_root *local_root;
 	struct btrfs_key key;
 
···
 				  (char *)(unsigned long)ipath->fspath->val[i]);
 
 	btrfs_put_root(local_root);
-	free_ipath(ipath);
 	return 0;
 
 err:
···
 			  swarn->physical,
 			  root, inum, offset, ret);
 
-	free_ipath(ipath);
 	return 0;
 }