All cleanup paths lead to btrfs_path_free so we can define path with the
automatic free callback.

And David Sterba point out that: 
	We may still find cases worth converting, the typical pattern is
	btrfs_path_alloc() somewhere near top of the function and
	btrfs_free_path() called right before a return.

So let's convert it.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
---
 fs/btrfs/inode-item.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 3530de0618c8..c9d37f6bb099 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -456,7 +456,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 			       struct btrfs_truncate_control *control)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct extent_buffer *leaf;
 	struct btrfs_file_extent_item *fi;
 	struct btrfs_key key;
@@ -743,6 +743,5 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	if (!ret && control->last_size > new_size)
 		control->last_size = new_size;
 
-	btrfs_free_path(path);
 	return ret;
 }
-- 
2.39.0

On Fri, 11 Apr 2025 at 05:25, Yangtao Li <frank.li@vivo.com> wrote:
>
> All cleanup paths lead to btrfs_path_free so we can define path with the
> automatic free callback.
>
> And David Sterba point out that:
>         We may still find cases worth converting, the typical pattern is
>         btrfs_path_alloc() somewhere near top of the function and
>         btrfs_free_path() called right before a return.
>
> So let's convert it.
>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> ---
>  fs/btrfs/inode-item.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

And what about the other functions in that file? We could even get rid
of two allocations passing the path from ..._inode_ref() to
..._inode_extref().

> diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
> index 3530de0618c8..c9d37f6bb099 100644
> --- a/fs/btrfs/inode-item.c
> +++ b/fs/btrfs/inode-item.c
> @@ -456,7 +456,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
>                                struct btrfs_truncate_control *control)
>  {
>         struct btrfs_fs_info *fs_info = root->fs_info;
> -       struct btrfs_path *path;
> +       BTRFS_PATH_AUTO_FREE(path);
>         struct extent_buffer *leaf;
>         struct btrfs_file_extent_item *fi;
>         struct btrfs_key key;
> @@ -743,6 +743,5 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
>         if (!ret && control->last_size > new_size)
>                 control->last_size = new_size;
>
> -       btrfs_free_path(path);
>         return ret;
>  }
> --
> 2.39.0
>
>

On Fri, Apr 11, 2025 at 04:17:38PM +0200, Daniel Vacek wrote:
> On Fri, 11 Apr 2025 at 05:25, Yangtao Li <frank.li@vivo.com> wrote:
> >
> > All cleanup paths lead to btrfs_path_free so we can define path with the
> > automatic free callback.
> >
> > And David Sterba point out that:
> >         We may still find cases worth converting, the typical pattern is
> >         btrfs_path_alloc() somewhere near top of the function and
> >         btrfs_free_path() called right before a return.
> >
> > So let's convert it.
> >
> > Signed-off-by: Yangtao Li <frank.li@vivo.com>
> > ---
> >  fs/btrfs/inode-item.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> And what about the other functions in that file? We could even get rid
> of two allocations passing the path from ..._inode_ref() to
> ..._inode_extref().

If you mean to pass the path object from btrfs_del_inode_ref() to
btrfs_del_inode_extref() yeah this looks like a good optimization and
reducing the allocations (and potential failures).

The other cases in the "..._inode_ref" is btrfs_insert_inode_ref() ->
btrfs_insert_inode_extref().