From patchwork Tue Mar 5 07:23:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13581757 X-Patchwork-Delegate: snitzer@redhat.com Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) (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 93B848062F for ; Tue, 5 Mar 2024 07:29:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709623779; cv=none; b=EVO78rne2BWM6SSClgji6w+PCMBsbkCKb8TafoHpQImprWb+49J7NWOPdMHGyg3KvLKVyof8+YzVJB4pUB9uVN1Y9HrRr78M1nUbr5vfpTwC46Wu916OsCPHi++72YuVem+iCdL4DQTL/nKtQaPCMfyLedw8ylHc6iYgQvXpFME= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709623779; c=relaxed/simple; bh=XvvAbpEePZjEC0cSUPQ2s2dg9t4q+qLsBBKfup6+WvE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GjaVc6EfVR5vinqQR7kDiVeHNv4MYgQrC/sa7Ja0tCdUUX3RqN9KFtFq91OIooqjbfIswJWUSoPF0aRf+PJ0o0Z8RIU+uR4mBVu0Y+fVq6OvS3DrsqwZuPABz1xOCGJJM8B11AQ0LpbLw5zKuUSvKrbz9r3a5lg1Ch6zhM45fno= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4TpnJ32f2qz4f3jrc for ; Tue, 5 Mar 2024 15:29:23 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id BE63C1A0568 for ; Tue, 5 Mar 2024 15:29:28 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgBHGBHRyeZlGnf+Fw--.17927S9; Tue, 05 Mar 2024 15:29:28 +0800 (CST) From: Yu Kuai To: xni@redhat.com, zkabelac@redhat.com, agk@redhat.com, snitzer@kernel.org, mpatocka@redhat.com, dm-devel@lists.linux.dev, song@kernel.org, yukuai3@huawei.com, heinzm@redhat.com, jbrassow@redhat.com, neilb@suse.de Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH md-6.8 v2 5/9] dm-raid: really frozen sync_thread during suspend Date: Tue, 5 Mar 2024 15:23:02 +0800 Message-Id: <20240305072306.2562024-6-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240305072306.2562024-1-yukuai1@huaweicloud.com> References: <20240305072306.2562024-1-yukuai1@huaweicloud.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgBHGBHRyeZlGnf+Fw--.17927S9 X-Coremail-Antispam: 1UD129KBjvJXoWxtry3CryrWw1rXw13tw13Arb_yoW7Zr1rpr WrtFs8Ar4UJrW7ZFZFy3WvqFW5ZwnIqrZrtry3W3yrA3WfKwsakFy09a47ZFWDGas7Ja4Y yan8tFW3u3WDKrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPF14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_WrylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUOBTY UUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ From: Yu Kuai 1) commit f52f5c71f3d4 ("md: fix stopping sync thread") remove MD_RECOVERY_FROZEN from __md_stop_writes() and doesn't realize that dm-raid relies on __md_stop_writes() to frozen sync_thread indirectly. Fix this problem by adding MD_RECOVERY_FROZEN in md_stop_writes(), and since stop_sync_thread() is only used for dm-raid in this case, also move stop_sync_thread() to md_stop_writes(). 2) The flag MD_RECOVERY_FROZEN doesn't mean that sync thread is frozen, it only prevent new sync_thread to start, and it can't stop the running sync thread; In order to frozen sync_thread, after seting the flag, stop_sync_thread() should be used. 3) The flag MD_RECOVERY_FROZEN doesn't mean that writes are stopped, use it as condition for md_stop_writes() in raid_postsuspend() doesn't look correct. Consider that reentrant stop_sync_thread() do nothing, always call md_stop_writes() in raid_postsuspend(). 4) raid_message can set/clear the flag MD_RECOVERY_FROZEN at anytime, and if MD_RECOVERY_FROZEN is cleared while the array is suspended, new sync_thread can start unexpected. Fix this by disallow raid_message() to change sync_thread status during suspend. Note that after commit f52f5c71f3d4 ("md: fix stopping sync thread"), the test shell/lvconvert-raid-reshape.sh start to hang in stop_sync_thread(), and with previous fixes, the test won't hang there anymore, however, the test will still fail and complain that ext4 is corrupted. And with this patch, the test won't hang due to stop_sync_thread() or fail due to ext4 is corrupted anymore. However, there is still a deadlock related to dm-raid456 that will be fixed in following patches. Reported-by: Mikulas Patocka Closes: https://lore.kernel.org/all/e5e8afe2-e9a8-49a2-5ab0-958d4065c55e@redhat.com/ Fixes: 1af2048a3e87 ("dm raid: fix deadlock caused by premature md_stop_writes()") Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer --- drivers/md/dm-raid.c | 25 +++++++++++++++---------- drivers/md/md.c | 3 ++- 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index eb009d6bb03a..e2d7a73c0f87 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3240,11 +3240,12 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv) rs->md.ro = 1; rs->md.in_sync = 1; - /* Keep array frozen until resume. */ - set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery); - /* Has to be held on running the array */ mddev_suspend_and_lock_nointr(&rs->md); + + /* Keep array frozen until resume. */ + md_frozen_sync_thread(&rs->md); + r = md_run(&rs->md); rs->md.in_sync = 0; /* Assume already marked dirty */ if (r) { @@ -3722,6 +3723,9 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; + if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) + return -EBUSY; + if (!strcasecmp(argv[0], "frozen")) set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); else @@ -3796,10 +3800,11 @@ static void raid_postsuspend(struct dm_target *ti) struct raid_set *rs = ti->private; if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) { - /* Writes have to be stopped before suspending to avoid deadlocks. */ - if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery)) - md_stop_writes(&rs->md); - + /* + * sync_thread must be stopped during suspend, and writes have + * to be stopped before suspending to avoid deadlocks. + */ + md_stop_writes(&rs->md); mddev_suspend(&rs->md, false); } } @@ -4012,8 +4017,6 @@ static int raid_preresume(struct dm_target *ti) } /* Check for any resize/reshape on @rs and adjust/initiate */ - /* Be prepared for mddev_resume() in raid_resume() */ - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) { set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); mddev->resync_min = mddev->recovery_cp; @@ -4055,10 +4058,12 @@ static void raid_resume(struct dm_target *ti) if (mddev->delta_disks < 0) rs_set_capacity(rs); + WARN_ON_ONCE(!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)); + WARN_ON_ONCE(test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)); mddev_lock_nointr(mddev); - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); mddev->ro = 0; mddev->in_sync = 0; + md_unfrozen_sync_thread(mddev); mddev_unlock_and_resume(mddev); } } diff --git a/drivers/md/md.c b/drivers/md/md.c index 306cbbf92fcf..e9e666240e9f 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6335,7 +6335,6 @@ static void md_clean(struct mddev *mddev) static void __md_stop_writes(struct mddev *mddev) { - stop_sync_thread(mddev, true, false); del_timer_sync(&mddev->safemode_timer); if (mddev->pers && mddev->pers->quiesce) { @@ -6360,6 +6359,8 @@ static void __md_stop_writes(struct mddev *mddev) void md_stop_writes(struct mddev *mddev) { mddev_lock_nointr(mddev); + set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + stop_sync_thread(mddev, true, false); __md_stop_writes(mddev); mddev_unlock(mddev); }