linux-kernel - [PATCH 2/2] btrfs: Prefer using the _

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Message-ID: <20250919145816.959845-3-mssola@mssola.com>
Date: Fri, 19 Sep 2025 16:58:16 +0200
From: Miquel Sabaté Solà <mssola@...ola.com>
To: linux-btrfs@...r.kernel.org
Cc: clm@...com,
	dsterba@...e.com,
	linux-kernel@...r.kernel.org,
	Miquel Sabaté Solà <mssola@...ola.com>
Subject: [PATCH 2/2] btrfs: Prefer using the __free cleanup attribute

In delayed-node.c and tree-log.c there were a couple of instances where
the __free(kfree) cleanup attribute allowed for more clear code and
safer for future changes, as they were in large functions with multiple
exit points and the end cleanup code was simply calling 'kfree' for the
ins_data variable.

Signed-off-by: Miquel Sabaté Solà <mssola@...ola.com>
---
 fs/btrfs/delayed-inode.c | 14 ++++++--------
 fs/btrfs/tree-log.c      | 21 ++++++++-------------
 2 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 81577a0c601f..dbc63dc414bb 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -668,7 +668,7 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 	struct btrfs_key first_key;
 	const u32 first_data_size = first_item->data_len;
 	int total_size;
-	char *ins_data = NULL;
+	char *ins_data __free(kfree) = NULL;
 	int ret;
 	bool continuous_keys_only = false;
 
@@ -740,10 +740,9 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 
 		ins_data = kmalloc_array(batch.nr,
 					 sizeof(u32) + sizeof(struct btrfs_key), GFP_NOFS);
-		if (!ins_data) {
-			ret = -ENOMEM;
-			goto out;
-		}
+		if (!ins_data)
+			return -ENOMEM;
+
 		ins_sizes = (u32 *)ins_data;
 		ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
 		batch.keys = ins_keys;
@@ -759,7 +758,7 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_insert_empty_items(trans, root, path, &batch);
 	if (ret)
-		goto out;
+		return ret;
 
 	list_for_each_entry(curr, &item_list, tree_list) {
 		char *data_ptr;
@@ -814,8 +813,7 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 		list_del(&curr->tree_list);
 		btrfs_release_delayed_item(curr);
 	}
-out:
-	kfree(ins_data);
+
 	return ret;
 }
 
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index d6471cd33f7f..c376514cf844 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3302,7 +3302,7 @@ static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
 	mutex_unlock(&root->log_mutex);
 }
 
-/* 
+/*
  * Invoked in log mutex context, or be sure there is no other task which
  * can access the list.
  */
@@ -4038,7 +4038,7 @@ static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
 				 int count)
 {
 	struct btrfs_root *log = inode->root->log_root;
-	char *ins_data = NULL;
+	char *ins_data __free(kfree) = NULL;
 	struct btrfs_item_batch batch;
 	struct extent_buffer *dst;
 	unsigned long src_offset;
@@ -4083,7 +4083,7 @@ static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
 	if (ret)
-		goto out;
+		return ret;
 
 	dst = dst_path->nodes[0];
 	/*
@@ -4115,8 +4115,6 @@ static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
 
 	if (btrfs_get_first_dir_index_to_log(inode) == 0)
 		btrfs_set_first_dir_index_to_log(inode, batch.keys[0].offset);
-out:
-	kfree(ins_data);
 
 	return ret;
 }
@@ -4786,7 +4784,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 	struct btrfs_key *ins_keys;
 	u32 *ins_sizes;
 	struct btrfs_item_batch batch;
-	char *ins_data;
+	char *ins_data __free(kfree) = NULL;
 	int dst_index;
 	const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
 	const u64 i_size = i_size_read(&inode->vfs_inode);
@@ -4914,7 +4912,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 					      disk_bytenr + extent_num_bytes - 1,
 					      &ordered_sums, false);
 		if (ret < 0)
-			goto out;
+			return ret;
 		ret = 0;
 
 		list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
@@ -4924,7 +4922,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 			kfree(sums);
 		}
 		if (ret)
-			goto out;
+			return ret;
 
 add_to_batch:
 		ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
@@ -4938,11 +4936,11 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 	 * so we don't need to do anything.
 	 */
 	if (batch.nr == 0)
-		goto out;
+		return 0;
 
 	ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
 	if (ret)
-		goto out;
+		return ret;
 
 	dst_index = 0;
 	for (int i = 0; i < nr; i++) {
@@ -4995,8 +4993,6 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 	}
 
 	btrfs_release_path(dst_path);
-out:
-	kfree(ins_data);
 
 	return ret;
 }
@@ -8082,4 +8078,3 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 		btrfs_end_log_trans(root);
 	free_extent_buffer(ctx.scratch_eb);
 }
-
-- 
2.51.0