[v4,1/3] btrfs: DEFINE_FREE for btrfs_free_path

Commit Message

Leo Martins Sept. 3, 2024, 6:19 p.m. UTC

CHANGELOG:
Move BTRFS_PATH_AUTO_FREE macro definition next to btrfs_path struct.

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.

Signed-off-by: Leo Martins <[e-mail]>
---
 fs/btrfs/ctree.c | 2 +-
 fs/btrfs/ctree.h | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

Patch

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 c8568b1a61c43..7a7b051e994ac 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>
@@ -84,6 +85,9 @@  struct btrfs_path {
 	unsigned int nowait:1;
 };
 
+#define BTRFS_PATH_AUTO_FREE(path_name) \
+	struct btrfs_path *path_name __free(btrfs_free_path) = NULL;
+
 /*
  * The state of btrfs root
  */
@@ -598,6 +602,7 @@  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 *, btrfs_free_path(_T))
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		   struct btrfs_path *path, int slot, int nr);