+ ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map.patch added to mm-nonmm-unstable branch

+ ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: ocfs2: use flexible array in 'struct ocfs2_recovery_map'
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: ocfs2: use flexible array in 'struct ocfs2_recovery_map'
Date: Sun, 16 Jul 2023 20:48:56 +0200

Turn 'rm_entries' in 'struct ocfs2_recovery_map' into a flexible array.

The advantages are:
   - save the size of a pointer when the new undo structure is allocated
   - avoid some always ugly pointer arithmetic to get the address of
    'rm_entries'
   - avoid an indirection when the array is accessed

While at it, use struct_size() to compute the size of the new undo
structure.

Link: https://lkml.kernel.org/r/c645911ffd2720fce5e344c17de642518cd0db52.1689533270.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/journal.c |    5 +----
 fs/ocfs2/journal.h |    2 +-
 2 files changed, 2 insertions(+), 5 deletions(-)

--- a/fs/ocfs2/journal.c~ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map
+++ a/fs/ocfs2/journal.c
@@ -178,16 +178,13 @@ int ocfs2_recovery_init(struct ocfs2_sup
 	osb->recovery_thread_task = NULL;
 	init_waitqueue_head(&osb->recovery_event);
 
-	rm = kzalloc(sizeof(struct ocfs2_recovery_map) +
-		     osb->max_slots * sizeof(unsigned int),
+	rm = kzalloc(struct_size(rm, rm_entries, osb->max_slots),
 		     GFP_KERNEL);
 	if (!rm) {
 		mlog_errno(-ENOMEM);
 		return -ENOMEM;
 	}
 
-	rm->rm_entries = (unsigned int *)((char *)rm +
-					  sizeof(struct ocfs2_recovery_map));
 	osb->recovery_map = rm;
 
 	return 0;
--- a/fs/ocfs2/journal.h~ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map
+++ a/fs/ocfs2/journal.h
@@ -29,7 +29,7 @@ struct ocfs2_dinode;
 
 struct ocfs2_recovery_map {
 	unsigned int rm_used;
-	unsigned int *rm_entries;
+	unsigned int rm_entries[];
 };
 
 
_

Patches currently in -mm which might be from christophe.jaillet@wanadoo.fr are

ipc-sem-use-flexible-array-in-struct-sem_undo.patch
ocfs2-use-flexible-array-in-struct-ocfs2_recovery_map.patch
ocfs2-use-struct_size.patch