From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kulikov Vasiliy Subject: [PATCH] md: do not use ++ in rcu_dereference() argument Date: Sun, 5 Sep 2010 22:32:18 +0400 Message-ID: <1283711539-7123-1-git-send-email-segooon@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-kernel-owner@vger.kernel.org To: kernel-janitors@vger.kernel.org Cc: Vasiliy Kulikov , Neil Brown , Jens Axboe , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-raid.ids =46rom: 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 =E2=80=98read_balance=E2=80=99: drivers/md/raid1.c:445: warning: operation on =E2=80=98new_disk=E2=80=99= 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_b= io) r1_bio->bios[new_disk] =3D=3D IO_BLOCKED || !rdev || !test_bit(In_sync, &rdev->flags) || test_bit(WriteMostly, &rdev->flags); - rdev =3D rcu_dereference(conf->mirrors[++new_disk].rdev)) { + rdev =3D rcu_dereference(conf->mirrors[new_disk].rdev)) { =20 if (rdev && test_bit(In_sync, &rdev->flags) && r1_bio->bios[new_disk] !=3D IO_BLOCKED) @@ -452,6 +452,7 @@ static int read_balance(conf_t *conf, r1bio_t *r1_b= io) new_disk =3D wonly_disk; break; } + new_disk++; } goto rb_out; } --=20 1.7.0.4