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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CAD47CCA47E for ; Tue, 7 Jun 2022 17:57:40 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-500-_KRzbt39M4iz--PWFick_A-1; Tue, 07 Jun 2022 13:57:36 -0400 X-MC-Unique: _KRzbt39M4iz--PWFick_A-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BAA8A800971; Tue, 7 Jun 2022 17:57:34 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id A89E5492CA3; Tue, 7 Jun 2022 17:57:34 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 6F0141947B83; Tue, 7 Jun 2022 17:57:34 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id C053A19452D2 for ; Tue, 7 Jun 2022 17:57:32 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id B23A61121315; Tue, 7 Jun 2022 17:57:32 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast09.extmail.prod.ext.rdu2.redhat.com [10.11.55.25]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AE8A91121314 for ; Tue, 7 Jun 2022 17:57:32 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8E4AF29ABA05 for ; Tue, 7 Jun 2022 17:57:32 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-622-u22SfOyWMN6y8dD0v6bATw-1; Tue, 07 Jun 2022 13:57:30 -0400 X-MC-Unique: u22SfOyWMN6y8dD0v6bATw-1 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AAFDA618A6; Tue, 7 Jun 2022 17:57:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D721FC385A5; Tue, 7 Jun 2022 17:57:27 +0000 (UTC) From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Date: Tue, 7 Jun 2022 13:55:30 -0400 Message-Id: <20220607175552.479948-31-sashal@kernel.org> In-Reply-To: <20220607175552.479948-1-sashal@kernel.org> References: <20220607175552.479948-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Mimecast-Bulk-Signature: yes X-Mimecast-Spam-Signature: bulk X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Subject: [dm-devel] [PATCH AUTOSEL 5.15 31/51] md: don't unregister sync_thread with reconfig_mutex held X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Guoqing Jiang , snitzer@kernel.org, linux-raid@vger.kernel.org, Song Liu , dm-devel@redhat.com, Donald Buczek , agk@redhat.com Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit From: Guoqing Jiang [ Upstream commit 8b48ec23cc51a4e7c8dbaef5f34ebe67e1a80934 ] Unregister sync_thread doesn't need to hold reconfig_mutex since it doesn't reconfigure array. And it could cause deadlock problem for raid5 as follows: 1. process A tried to reap sync thread with reconfig_mutex held after echo idle to sync_action. 2. raid5 sync thread was blocked if there were too many active stripes. 3. SB_CHANGE_PENDING was set (because of write IO comes from upper layer) which causes the number of active stripes can't be decreased. 4. SB_CHANGE_PENDING can't be cleared since md_check_recovery was not able to hold reconfig_mutex. More details in the link: https://lore.kernel.org/linux-raid/5ed54ffc-ce82-bf66-4eff-390cb23bc1ac@molgen.mpg.de/T/#t And add one parameter to md_reap_sync_thread since it could be called by dm-raid which doesn't hold reconfig_mutex. Reported-and-tested-by: Donald Buczek Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/dm-raid.c | 2 +- drivers/md/md.c | 14 +++++++++----- drivers/md/md.h | 2 +- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index d9ef52159a22..dbfdc13988dc 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3730,7 +3730,7 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) { if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, false); } } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle) return -EBUSY; diff --git a/drivers/md/md.c b/drivers/md/md.c index 5ce2648cbe5b..8d569db21b1a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4842,7 +4842,7 @@ action_store(struct mddev *mddev, const char *page, size_t len) flush_workqueue(md_misc_wq); if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); } mddev_unlock(mddev); } @@ -6204,7 +6204,7 @@ static void __md_stop_writes(struct mddev *mddev) flush_workqueue(md_misc_wq); if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); } del_timer_sync(&mddev->safemode_timer); @@ -9301,7 +9301,7 @@ void md_check_recovery(struct mddev *mddev) * ->spare_active and clear saved_raid_disk */ set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags); @@ -9336,7 +9336,7 @@ void md_check_recovery(struct mddev *mddev) goto unlock; } if (mddev->sync_thread) { - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); goto unlock; } /* Set RUNNING before clearing NEEDED to avoid @@ -9409,14 +9409,18 @@ void md_check_recovery(struct mddev *mddev) } EXPORT_SYMBOL(md_check_recovery); -void md_reap_sync_thread(struct mddev *mddev) +void md_reap_sync_thread(struct mddev *mddev, bool reconfig_mutex_held) { struct md_rdev *rdev; sector_t old_dev_sectors = mddev->dev_sectors; bool is_reshaped = false; + if (reconfig_mutex_held) + mddev_unlock(mddev); /* resync has finished, collect result */ md_unregister_thread(&mddev->sync_thread); + if (reconfig_mutex_held) + mddev_lock_nointr(mddev); if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && mddev->degraded != mddev->raid_disks) { diff --git a/drivers/md/md.h b/drivers/md/md.h index 62852d701145..3aa09e0d9f89 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -711,7 +711,7 @@ extern struct md_thread *md_register_thread( extern void md_unregister_thread(struct md_thread **threadp); extern void md_wakeup_thread(struct md_thread *thread); extern void md_check_recovery(struct mddev *mddev); -extern void md_reap_sync_thread(struct mddev *mddev); +extern void md_reap_sync_thread(struct mddev *mddev, bool reconfig_mutex_held); extern int mddev_init_writes_pending(struct mddev *mddev); extern bool md_write_start(struct mddev *mddev, struct bio *bi); extern void md_write_inc(struct mddev *mddev, struct bio *bi); -- 2.35.1 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel 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 C20D1CCA483 for ; Tue, 7 Jun 2022 18:34:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352564AbiFGSev (ORCPT ); Tue, 7 Jun 2022 14:34:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352290AbiFGSdh (ORCPT ); Tue, 7 Jun 2022 14:33:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0130F17F800; Tue, 7 Jun 2022 10:57:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 58094B82239; Tue, 7 Jun 2022 17:57:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D721FC385A5; Tue, 7 Jun 2022 17:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654624649; bh=djfkJGyl9Urrz2t1OhokRNIKnl9BVSRu5D6W8hRQ91M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mMpskNmouCJ8GdR5o8pmpIPP3NDjci51pOZiZ9bR1u56wxDauIbKA6zLPViGOh1/r VwingW3JCUky2caRohyi56NIjtyqzU1xKkIAQfn/wdmo0LzWpiGpVnCpfV09K2MJxq DaOsECyuepO5sjjKI1cTgriNSfVNCHNe4PGEAF+kVhb4Q9Y5eCAha1TsHNtQ5S3+Fv hDP9Pf2kuH7lVCf13dTWQMnt7QJzVzDyoeW09u+mB0c+kBLw5GNodJyA7uP7e7QDOf /Uwq+jprnaatOPkWfHbBsRVtFHIFmm6tkPFLR4QQTsyeo7L6yQYH70wm8kqE+riq7K 82NiCWXoMRNdw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Guoqing Jiang , Donald Buczek , Song Liu , Sasha Levin , agk@redhat.com, snitzer@kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 31/51] md: don't unregister sync_thread with reconfig_mutex held Date: Tue, 7 Jun 2022 13:55:30 -0400 Message-Id: <20220607175552.479948-31-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220607175552.479948-1-sashal@kernel.org> References: <20220607175552.479948-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Guoqing Jiang [ Upstream commit 8b48ec23cc51a4e7c8dbaef5f34ebe67e1a80934 ] Unregister sync_thread doesn't need to hold reconfig_mutex since it doesn't reconfigure array. And it could cause deadlock problem for raid5 as follows: 1. process A tried to reap sync thread with reconfig_mutex held after echo idle to sync_action. 2. raid5 sync thread was blocked if there were too many active stripes. 3. SB_CHANGE_PENDING was set (because of write IO comes from upper layer) which causes the number of active stripes can't be decreased. 4. SB_CHANGE_PENDING can't be cleared since md_check_recovery was not able to hold reconfig_mutex. More details in the link: https://lore.kernel.org/linux-raid/5ed54ffc-ce82-bf66-4eff-390cb23bc1ac@molgen.mpg.de/T/#t And add one parameter to md_reap_sync_thread since it could be called by dm-raid which doesn't hold reconfig_mutex. Reported-and-tested-by: Donald Buczek Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/dm-raid.c | 2 +- drivers/md/md.c | 14 +++++++++----- drivers/md/md.h | 2 +- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index d9ef52159a22..dbfdc13988dc 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3730,7 +3730,7 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) { if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, false); } } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle) return -EBUSY; diff --git a/drivers/md/md.c b/drivers/md/md.c index 5ce2648cbe5b..8d569db21b1a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4842,7 +4842,7 @@ action_store(struct mddev *mddev, const char *page, size_t len) flush_workqueue(md_misc_wq); if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); } mddev_unlock(mddev); } @@ -6204,7 +6204,7 @@ static void __md_stop_writes(struct mddev *mddev) flush_workqueue(md_misc_wq); if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); } del_timer_sync(&mddev->safemode_timer); @@ -9301,7 +9301,7 @@ void md_check_recovery(struct mddev *mddev) * ->spare_active and clear saved_raid_disk */ set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags); @@ -9336,7 +9336,7 @@ void md_check_recovery(struct mddev *mddev) goto unlock; } if (mddev->sync_thread) { - md_reap_sync_thread(mddev); + md_reap_sync_thread(mddev, true); goto unlock; } /* Set RUNNING before clearing NEEDED to avoid @@ -9409,14 +9409,18 @@ void md_check_recovery(struct mddev *mddev) } EXPORT_SYMBOL(md_check_recovery); -void md_reap_sync_thread(struct mddev *mddev) +void md_reap_sync_thread(struct mddev *mddev, bool reconfig_mutex_held) { struct md_rdev *rdev; sector_t old_dev_sectors = mddev->dev_sectors; bool is_reshaped = false; + if (reconfig_mutex_held) + mddev_unlock(mddev); /* resync has finished, collect result */ md_unregister_thread(&mddev->sync_thread); + if (reconfig_mutex_held) + mddev_lock_nointr(mddev); if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && mddev->degraded != mddev->raid_disks) { diff --git a/drivers/md/md.h b/drivers/md/md.h index 62852d701145..3aa09e0d9f89 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -711,7 +711,7 @@ extern struct md_thread *md_register_thread( extern void md_unregister_thread(struct md_thread **threadp); extern void md_wakeup_thread(struct md_thread *thread); extern void md_check_recovery(struct mddev *mddev); -extern void md_reap_sync_thread(struct mddev *mddev); +extern void md_reap_sync_thread(struct mddev *mddev, bool reconfig_mutex_held); extern int mddev_init_writes_pending(struct mddev *mddev); extern bool md_write_start(struct mddev *mddev, struct bio *bi); extern void md_write_inc(struct mddev *mddev, struct bio *bi); -- 2.35.1