From nobody Mon Feb 9 09:29:09 2026 Received: from canpmsgout03.his.huawei.com (canpmsgout03.his.huawei.com [113.46.200.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83EF636999F for ; Fri, 16 Jan 2026 12:11:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.218 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768565494; cv=none; b=WZ70ctlVKrY4fz0Opw9lYww5pU9MMrbvaUUulDuF7hiZ6Fjl4hjXAX59khhozVbFQgycDBvjdUSsa4kGcMVMqE6uE0ufai+eaH7R4w3L5ekt7gtJNwgVEJwmrgFRHvy6BVrzRa/POTIr7jlccNNfLbbHCQPSlEa5n1/SM/A108s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768565494; c=relaxed/simple; bh=/Yd34El++CCt08toxVD8Oe+2GJdlGtPi5iTl12UsvJg=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=AXCiQf9lIp4Cii437dCDaxxNnWZWSsrcwYFlNZoXtkEh7yjPlFD0Acm7esK1meYsOsVGptkZQZ1WAQIFxT8CD2x0OmmDB8Ki+eL9MBXBg7ov52uiSuaeQRJNIzR3e26LECY9Xen4xfaujQHJbfUlh5CL6YyH/x3fEau5Vt0TjTQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=D8HfNTRW; arc=none smtp.client-ip=113.46.200.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="D8HfNTRW" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=nYmaYPLH2er8UG6enM6EeoVcPjWY0mCAQvIGP55CyfE=; b=D8HfNTRWRHbiGPmsG/tQ7VXp1tMWTofz8Dn/cJfF1qpGhS1wa8yV0OOln/hjjAMcJO3RehEqi tL24dhTdZDzKFOWIKYnsLi04YNMThwIvKE91VVQxSa1JU5/7BhGT+1tP/UY+RHkdcgQ9pdAkPpO tVjco/AUuApKBmy1L1yuDBs= Received: from mail.maildlp.com (unknown [172.19.163.0]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4dszBZ3dXJzpStc; Fri, 16 Jan 2026 20:07:50 +0800 (CST) Received: from kwepemk500005.china.huawei.com (unknown [7.202.194.90]) by mail.maildlp.com (Postfix) with ESMTPS id BD11D405AA; Fri, 16 Jan 2026 20:11:27 +0800 (CST) Received: from huawei.com (10.50.85.155) by kwepemk500005.china.huawei.com (7.202.194.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 16 Jan 2026 20:11:27 +0800 From: Zhihao Cheng To: , , , CC: , , , , Subject: [PATCH] dm: pass origin bio's bdev to bio_alloc_clone Date: Fri, 16 Jan 2026 20:07:44 +0800 Message-ID: <20260116120744.908987-1-chengzhihao1@huawei.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemk500005.china.huawei.com (7.202.194.90) Content-Type: text/plain; charset="utf-8" The origin bio carries blk-cgroup information which could be set from foreground(task_css(css) - wbc->wb->blkcg_css), so the blkcg won't control buffer io since commit ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone"). The synchronous io is still under control by blkcg, because 'bio->bi_blkg' is set by io submitting task which has been added into 'cgroup.procs'. Fix it by passing origin bio's bdev to bio_alloc_clone. Fetch a reproducer in [Link]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D220985 Fixes: ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone") Signed-off-by: Zhihao Cheng Reported-by: Zhihao Cheng Tested-by: Zhihao Cheng --- drivers/md/dm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b63279202260..e763e3b02a9f 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -574,7 +574,8 @@ static struct dm_io *alloc_io(struct mapped_device *md,= struct bio *bio, gfp_t g struct dm_target_io *tio; struct bio *clone; =20 - clone =3D bio_alloc_clone(NULL, bio, gfp_mask, &md->mempools->io_bs); + clone =3D bio_alloc_clone(bio->bi_bdev, bio, + gfp_mask, &md->mempools->io_bs); if (unlikely(!clone)) return NULL; tio =3D clone_to_tio(clone); @@ -623,7 +624,7 @@ static struct bio *alloc_tio(struct clone_info *ci, str= uct dm_target *ti, /* alloc_io() already initialized embedded clone */ clone =3D &tio->clone; } else { - clone =3D bio_alloc_clone(NULL, ci->bio, gfp_mask, + clone =3D bio_alloc_clone(ci->bio->bi_bdev, ci->bio, gfp_mask, &md->mempools->bs); if (!clone) return NULL; --=20 2.52.0