From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C92FC433FE for ; Wed, 12 Oct 2022 09:12:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229600AbiJLJMC (ORCPT ); Wed, 12 Oct 2022 05:12:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbiJLJMB (ORCPT ); Wed, 12 Oct 2022 05:12:01 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4608140F0 for ; Wed, 12 Oct 2022 02:11:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665565919; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=RffXF9uyy/RyxQnExvSTJHQB+wqUrWV456Sz30I3FSk=; b=VitYFRCf4t0bMxEkvj7g+MfKGGobyVIqtrEJPek9iGyHmfCAI1r8KJl7OJvPBSdqkBr5a0 EN57uyt/UIc5zCZ75cwrsSHGWSfdzntzSFIn7w2huuubZA3qFFWY1C/GFYEiU8s8Ew3VGd nfYg/Kw+Gq5TlWzFy2JyGfjplKRe+8g= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-34-qc0TeawDMPWZe63xuKeBew-1; Wed, 12 Oct 2022 05:11:55 -0400 X-MC-Unique: qc0TeawDMPWZe63xuKeBew-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7B6A81C05ACA; Wed, 12 Oct 2022 09:11:55 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-42.pek2.redhat.com [10.72.12.42]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6E71D4EA47; Wed, 12 Oct 2022 09:11:53 +0000 (UTC) From: Xiao Ni To: song@kernel.org Cc: ffan@redhat.com, guoqing.jiang@linux.dev, linux-raid@vger.kernel.org Subject: [PATCH 1/1] Add mddev->io_acct_cnt for raid0_quiesce Date: Wed, 12 Oct 2022 17:11:51 +0800 Message-Id: <20221012091151.71241-1-xni@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org It has added io_acct_set for raid0/raid5 io accounting and it needs to alloc md_io_acct in the i/o path. They are free when the bios come back from member disks. Now we don't have a method to monitor if those bios are all come back. In the takeover process, it needs to free the raid0 memory resource including the memory pool for md_io_acct. But maybe some bios are still not returned. When those bios are returned, it can cause panic bcause of introducing NULL pointer or invalid address. This patch adds io_acct_cnt. So when stopping raid0, it can use this to wait until all bios come back. Reported-by: Fine Fan Signed-off-by: Xiao Ni --- drivers/md/md.c | 10 +++++++++- drivers/md/md.h | 8 +++++--- drivers/md/raid0.c | 8 ++++++++ drivers/md/raid0.h | 1 + 4 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 9dc0175280b4..d6e9fa914087 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8600,15 +8600,18 @@ int acct_bioset_init(struct mddev *mddev) { int err = 0; - if (!bioset_initialized(&mddev->io_acct_set)) + if (!bioset_initialized(&mddev->io_acct_set)) { + atomic_set(&mddev->io_acct_cnt, 0); err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE, offsetof(struct md_io_acct, bio_clone), 0); + } return err; } EXPORT_SYMBOL_GPL(acct_bioset_init); void acct_bioset_exit(struct mddev *mddev) { + WARN_ON(atomic_read(&mddev->io_acct_cnt) != 0); bioset_exit(&mddev->io_acct_set); } EXPORT_SYMBOL_GPL(acct_bioset_exit); @@ -8617,12 +8620,15 @@ static void md_end_io_acct(struct bio *bio) { struct md_io_acct *md_io_acct = bio->bi_private; struct bio *orig_bio = md_io_acct->orig_bio; + struct mddev *mddev = md_io_acct->mddev; orig_bio->bi_status = bio->bi_status; bio_end_io_acct(orig_bio, md_io_acct->start_time); bio_put(bio); bio_endio(orig_bio); + + atomic_dec(&mddev->io_acct_cnt); } /* @@ -8642,6 +8648,8 @@ void md_account_bio(struct mddev *mddev, struct bio **bio) md_io_acct = container_of(clone, struct md_io_acct, bio_clone); md_io_acct->orig_bio = *bio; md_io_acct->start_time = bio_start_io_acct(*bio); + md_io_acct->mddev = mddev; + atomic_inc(&mddev->io_acct_cnt); clone->bi_end_io = md_end_io_acct; clone->bi_private = md_io_acct; diff --git a/drivers/md/md.h b/drivers/md/md.h index b4e2d8b87b61..29d30642e13f 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -513,6 +513,7 @@ struct mddev { * metadata and bitmap writes */ struct bio_set io_acct_set; /* for raid0 and raid5 io accounting */ + atomic_t io_acct_cnt; /* Generic flush handling. * The last to finish preflush schedules a worker to submit @@ -710,9 +711,10 @@ struct md_thread { }; struct md_io_acct { - struct bio *orig_bio; - unsigned long start_time; - struct bio bio_clone; + struct bio *orig_bio; + unsigned long start_time; + struct bio bio_clone; + struct mddev *mddev; }; #define THREAD_WAKEUP 0 diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 857c49399c28..1d2e098e0d52 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -73,6 +73,8 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) *private_conf = ERR_PTR(-ENOMEM); if (!conf) return -ENOMEM; + + init_waitqueue_head(&conf->wait_quiesce); rdev_for_each(rdev1, mddev) { pr_debug("md/raid0:%s: looking at %pg\n", mdname(mddev), @@ -754,6 +756,12 @@ static void *raid0_takeover(struct mddev *mddev) static void raid0_quiesce(struct mddev *mddev, int quiesce) { + struct r0conf *conf = mddev->private; + + /* It doesn't use a separate struct to count how many bios are submitted + * to member disks to avoid memory alloc and performance decrease + */ + wait_event(conf->wait_quiesce, atomic_read(&mddev->io_acct_cnt) == 0); } static struct md_personality raid0_personality= diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h index 3816e5477db1..560dec93d459 100644 --- a/drivers/md/raid0.h +++ b/drivers/md/raid0.h @@ -27,6 +27,7 @@ struct r0conf { * by strip_zone->dev */ int nr_strip_zones; enum r0layout layout; + wait_queue_head_t wait_quiesce; }; #endif -- 2.32.0 (Apple Git-132)