Re: [PATCH v2 1/3] btrfs: DEFINE_FREE for btrfs_free_path

[Josef Bacik <josef@toxicpanda.com>]

On Tue, Aug 27, 2024 at 12:08:43PM -0700, Leo Martins wrote:
> Add a DEFINE_FREE for btrfs_free_path. This defines a function that can
> be called using the __free attribute. Defined a macro
> BTRFS_PATH_AUTO_FREE to make the declaration of an auto freeing path
> very clear.
> ---
>  fs/btrfs/ctree.c | 2 +-
>  fs/btrfs/ctree.h | 4 ++++
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index 451203055bbfb..f0bdea206d672 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -196,7 +196,7 @@ struct btrfs_path *btrfs_alloc_path(void)
>  /* this also releases the path */
>  void btrfs_free_path(struct btrfs_path *p)
>  {
> -	if (!p)
> +	if (IS_ERR_OR_NULL(p))
>  		return;
>  	btrfs_release_path(p);
>  	kmem_cache_free(btrfs_path_cachep, p);
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 75fa563e4cacb..babc86af564a2 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -6,6 +6,7 @@
>  #ifndef BTRFS_CTREE_H
>  #define BTRFS_CTREE_H
>  
> +#include "linux/cleanup.h"
>  #include <linux/pagemap.h>
>  #include <linux/spinlock.h>
>  #include <linux/rbtree.h>
> @@ -599,6 +600,9 @@ int btrfs_search_slot_for_read(struct btrfs_root *root,
>  void btrfs_release_path(struct btrfs_path *p);
>  struct btrfs_path *btrfs_alloc_path(void);
>  void btrfs_free_path(struct btrfs_path *p);
> +DEFINE_FREE(btrfs_free_path, struct btrfs_path *, if (!IS_ERR_OR_NULL(_T)) btrfs_free_path(_T))

Remember to run "git commit -s" so you get your signed-off-by automatically
added.

You don't need the extra IS_ERR_OR_NULL bit if the free has it, so you can keep
the change above and just have btrfs_free_path(_T) here.  Thanks,

Josef