From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kulikov Vasiliy Date: Sun, 05 Sep 2010 18:32:18 +0000 Subject: [PATCH] md: do not use ++ in rcu_dereference() argument Message-Id: <1283711539-7123-1-git-send-email-segooon@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: kernel-janitors@vger.kernel.org Cc: Vasiliy Kulikov , Neil Brown , Jens Axboe , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org From: Vasiliy Kulikov rcu_dereference() is macro, so it might use its argument twice. Argument must not has side effects. It was found by compiler warning: drivers/md/raid1.c: In function ‘read_balance’: drivers/md/raid1.c:445: warning: operation on ‘new_disk’ may be undefined Signed-off-by: Vasiliy Kulikov --- drivers/md/raid1.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index ad83a4d..12194df 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -442,7 +442,7 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) r1_bio->bios[new_disk] = IO_BLOCKED || !rdev || !test_bit(In_sync, &rdev->flags) || test_bit(WriteMostly, &rdev->flags); - rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) { + rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) { if (rdev && test_bit(In_sync, &rdev->flags) && r1_bio->bios[new_disk] != IO_BLOCKED) @@ -452,6 +452,7 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) new_disk = wonly_disk; break; } + new_disk++; } goto rb_out; } -- 1.7.0.4