From patchwork Sun Apr 2 09:12:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13197301 X-Patchwork-Delegate: song@kernel.org 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 204FFC77B60 for ; Sun, 2 Apr 2023 09:13:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230315AbjDBJNQ (ORCPT ); Sun, 2 Apr 2023 05:13:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230294AbjDBJNL (ORCPT ); Sun, 2 Apr 2023 05:13:11 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B4A5C66C; Sun, 2 Apr 2023 02:13:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Pq7bf5PCPz4f3l8k; Sun, 2 Apr 2023 17:13:02 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3X7MeRylkVUE8Gg--.50168S5; Sun, 02 Apr 2023 17:13:04 +0800 (CST) From: Yu Kuai To: logang@deltatee.com, song@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH v4 1/5] md: pass a md_thread pointer to md_register_thread() Date: Sun, 2 Apr 2023 17:12:32 +0800 Message-Id: <20230402091236.976723-2-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230402091236.976723-1-yukuai1@huaweicloud.com> References: <20230402091236.976723-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3X7MeRylkVUE8Gg--.50168S5 X-Coremail-Antispam: 1UD129KBjvJXoW3JFy3uFykCryfGF15KF1ftFb_yoWfAr4xpa yxWFyayr48ArW3ZrWDAa4Dua45uw10gFWjyry3C34fA3ZxK3y3JFyY9FyUJryDAa4rAF43 tw15KFW8uF4kKr7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9v14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r1I6r4UM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMxC20s 026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_ JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14 v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xva j40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JV W8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbec_DUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai Prepare to protect md_thread with rcu, there are no functional changes. Signed-off-by: Yu Kuai --- drivers/md/md-cluster.c | 11 +++++------ drivers/md/md-multipath.c | 6 +++--- drivers/md/md.c | 27 ++++++++++++++------------- drivers/md/md.h | 7 +++---- drivers/md/raid1.c | 5 ++--- drivers/md/raid10.c | 15 ++++++--------- drivers/md/raid5-cache.c | 5 ++--- drivers/md/raid5.c | 15 ++++++--------- 8 files changed, 41 insertions(+), 50 deletions(-) diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index 10e0c5381d01..c19e29cb73bf 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -362,9 +362,8 @@ static void __recover_slot(struct mddev *mddev, int slot) set_bit(slot, &cinfo->recovery_map); if (!cinfo->recovery_thread) { - cinfo->recovery_thread = md_register_thread(recover_bitmaps, - mddev, "recover"); - if (!cinfo->recovery_thread) { + if (md_register_thread(&cinfo->recovery_thread, recover_bitmaps, + mddev, "recover")) { pr_warn("md-cluster: Could not create recovery thread\n"); return; } @@ -888,9 +887,9 @@ static int join(struct mddev *mddev, int nodes) goto err; } /* Initiate the communication resources */ - ret = -ENOMEM; - cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv"); - if (!cinfo->recv_thread) { + ret = md_register_thread(&cinfo->recv_thread, recv_daemon, mddev, + "cluster_recv"); + if (ret) { pr_err("md-cluster: cannot allocate memory for recv_thread!\n"); goto err; } diff --git a/drivers/md/md-multipath.c b/drivers/md/md-multipath.c index 66edf5e72bd6..ceec9e4b2a60 100644 --- a/drivers/md/md-multipath.c +++ b/drivers/md/md-multipath.c @@ -400,9 +400,9 @@ static int multipath_run (struct mddev *mddev) if (ret) goto out_free_conf; - mddev->thread = md_register_thread(multipathd, mddev, - "multipath"); - if (!mddev->thread) + ret = md_register_thread(&mddev->thread, multipathd, mddev, + "multipath"); + if (ret) goto out_free_conf; pr_info("multipath: array %s active with %d out of %d IO paths\n", diff --git a/drivers/md/md.c b/drivers/md/md.c index 9bc05f451d42..1459c2cfb0dd 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7896,29 +7896,32 @@ void md_wakeup_thread(struct md_thread *thread) } EXPORT_SYMBOL(md_wakeup_thread); -struct md_thread *md_register_thread(void (*run) (struct md_thread *), - struct mddev *mddev, const char *name) +int md_register_thread(struct md_thread **threadp, + void (*run)(struct md_thread *), + struct mddev *mddev, const char *name) { struct md_thread *thread; thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL); if (!thread) - return NULL; + return -ENOMEM; init_waitqueue_head(&thread->wqueue); thread->run = run; thread->mddev = mddev; thread->timeout = MAX_SCHEDULE_TIMEOUT; - thread->tsk = kthread_run(md_thread, thread, - "%s_%s", - mdname(thread->mddev), - name); + thread->tsk = kthread_run(md_thread, thread, "%s_%s", + mdname(thread->mddev), name); if (IS_ERR(thread->tsk)) { + int err = PTR_ERR(thread->tsk); + kfree(thread); - return NULL; + return err; } - return thread; + + *threadp = thread; + return 0; } EXPORT_SYMBOL(md_register_thread); @@ -9199,10 +9202,8 @@ static void md_start_sync(struct work_struct *ws) { struct mddev *mddev = container_of(ws, struct mddev, del_work); - mddev->sync_thread = md_register_thread(md_do_sync, - mddev, - "resync"); - if (!mddev->sync_thread) { + if (md_register_thread(&mddev->sync_thread, md_do_sync, mddev, + "resync")) { pr_warn("%s: could not start resync thread...\n", mdname(mddev)); /* leave the spares where they are, it shouldn't hurt */ diff --git a/drivers/md/md.h b/drivers/md/md.h index e148e3c83b0d..344e055e4d0f 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -730,10 +730,9 @@ extern int register_md_cluster_operations(struct md_cluster_operations *ops, extern int unregister_md_cluster_operations(void); extern int md_setup_cluster(struct mddev *mddev, int nodes); extern void md_cluster_stop(struct mddev *mddev); -extern struct md_thread *md_register_thread( - void (*run)(struct md_thread *thread), - struct mddev *mddev, - const char *name); +int md_register_thread(struct md_thread **threadp, + void (*run)(struct md_thread *thread), + struct mddev *mddev, const char *name); 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); diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 68a9e2d9985b..1217c1db0a40 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -3083,9 +3083,8 @@ static struct r1conf *setup_conf(struct mddev *mddev) } } - err = -ENOMEM; - conf->thread = md_register_thread(raid1d, mddev, "raid1"); - if (!conf->thread) + err = md_register_thread(&conf->thread, raid1d, mddev, "raid1"); + if (err) goto abort; return conf; diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 6c66357f92f5..0171ba4f19b0 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -4077,9 +4077,8 @@ static struct r10conf *setup_conf(struct mddev *mddev) init_waitqueue_head(&conf->wait_barrier); atomic_set(&conf->nr_pending, 0); - err = -ENOMEM; - conf->thread = md_register_thread(raid10d, mddev, "raid10"); - if (!conf->thread) + err = md_register_thread(&conf->thread, raid10d, mddev, "raid10"); + if (err) goto out; conf->mddev = mddev; @@ -4273,9 +4272,8 @@ static int raid10_run(struct mddev *mddev) clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - mddev->sync_thread = md_register_thread(md_do_sync, mddev, - "reshape"); - if (!mddev->sync_thread) + if (md_register_thread(&mddev->sync_thread, md_do_sync, mddev, + "reshape")) goto out_free_conf; } @@ -4686,9 +4684,8 @@ static int raid10_start_reshape(struct mddev *mddev) set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - mddev->sync_thread = md_register_thread(md_do_sync, mddev, - "reshape"); - if (!mddev->sync_thread) { + if (md_register_thread(&mddev->sync_thread, md_do_sync, mddev, + "reshape")) { ret = -EAGAIN; goto abort; } diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 46182b955aef..0464d4d551fc 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -3121,9 +3121,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) spin_lock_init(&log->tree_lock); INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN); - log->reclaim_thread = md_register_thread(r5l_reclaim_thread, - log->rdev->mddev, "reclaim"); - if (!log->reclaim_thread) + if (md_register_thread(&log->reclaim_thread, r5l_reclaim_thread, + log->rdev->mddev, "reclaim")) goto reclaim_thread; log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL; diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7b820b81d8c2..04b1093195d0 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7665,11 +7665,10 @@ static struct r5conf *setup_conf(struct mddev *mddev) } sprintf(pers_name, "raid%d", mddev->new_level); - conf->thread = md_register_thread(raid5d, mddev, pers_name); - if (!conf->thread) { + ret = md_register_thread(&conf->thread, raid5d, mddev, pers_name); + if (ret) { pr_warn("md/raid:%s: couldn't allocate thread.\n", mdname(mddev)); - ret = -ENOMEM; goto abort; } @@ -7989,9 +7988,8 @@ static int raid5_run(struct mddev *mddev) clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - mddev->sync_thread = md_register_thread(md_do_sync, mddev, - "reshape"); - if (!mddev->sync_thread) + if (md_register_thread(&mddev->sync_thread, md_do_sync, mddev, + "reshape")) goto abort; } @@ -8567,9 +8565,8 @@ static int raid5_start_reshape(struct mddev *mddev) clear_bit(MD_RECOVERY_DONE, &mddev->recovery); set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - mddev->sync_thread = md_register_thread(md_do_sync, mddev, - "reshape"); - if (!mddev->sync_thread) { + if (md_register_thread(&mddev->sync_thread, md_do_sync, mddev, + "reshape")) { mddev->recovery = 0; spin_lock_irq(&conf->device_lock); write_seqcount_begin(&conf->gen_lock); From patchwork Sun Apr 2 09:12:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13197298 X-Patchwork-Delegate: song@kernel.org 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 A58BFC7619A for ; Sun, 2 Apr 2023 09:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230301AbjDBJNM (ORCPT ); Sun, 2 Apr 2023 05:13:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230090AbjDBJNK (ORCPT ); Sun, 2 Apr 2023 05:13:10 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B4DCCC19; Sun, 2 Apr 2023 02:13:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Pq7bg0rxTz4f3lX9; Sun, 2 Apr 2023 17:13:03 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3X7MeRylkVUE8Gg--.50168S6; Sun, 02 Apr 2023 17:13:04 +0800 (CST) From: Yu Kuai To: logang@deltatee.com, song@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH v4 2/5] md: factor out a helper to wake up md_thread directly Date: Sun, 2 Apr 2023 17:12:33 +0800 Message-Id: <20230402091236.976723-3-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230402091236.976723-1-yukuai1@huaweicloud.com> References: <20230402091236.976723-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3X7MeRylkVUE8Gg--.50168S6 X-Coremail-Antispam: 1UD129KBjvJXoW7KryktrWfAw15uw43tFykGrg_yoW5JFy8pa y8tF15Wr48ArZxZFZrJa4qya45Xr10qFy7try3C3yrJw1rKw45tFya9Fyjya4DAF95Ar45 Xw15tFWruw4vkF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9v14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMxC20s 026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_ JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14 v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xva j40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JV W8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUjYiiDUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai md_wakeup_thread() can't wakeup md_thread->tsk if md_thread->run is still in progress, and in some cases md_thread->tsk need to be woke up directly, like md_set_readonly(), do_md_stop(), and perhaps later in action_store(). This patch factor out a helper to wake up md_thread directly, prepare to protect md_thread with rcu. Signed-off-by: Yu Kuai --- drivers/md/md.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 1459c2cfb0dd..139c7b0202e3 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -92,6 +92,7 @@ static struct workqueue_struct *md_rdev_misc_wq; static int remove_and_add_spares(struct mddev *mddev, struct md_rdev *this); static void mddev_detach(struct mddev *mddev); +static void md_wakeup_thread_directly(struct md_thread *thread); enum md_ro_state { MD_RDWR, @@ -6269,10 +6270,12 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev) } if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) set_bit(MD_RECOVERY_INTR, &mddev->recovery); - if (mddev->sync_thread) - /* Thread might be blocked waiting for metadata update - * which will now never happen */ - wake_up_process(mddev->sync_thread->tsk); + + /* + * Thread might be blocked waiting for metadata update which will now + * never happen + */ + md_wakeup_thread_directly(mddev->sync_thread); if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) return -EBUSY; @@ -6333,10 +6336,12 @@ static int do_md_stop(struct mddev *mddev, int mode, } if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) set_bit(MD_RECOVERY_INTR, &mddev->recovery); - if (mddev->sync_thread) - /* Thread might be blocked waiting for metadata update - * which will now never happen */ - wake_up_process(mddev->sync_thread->tsk); + + /* + * Thread might be blocked waiting for metadata update which will now + * never happen + */ + md_wakeup_thread_directly(mddev->sync_thread); mddev_unlock(mddev); wait_event(resync_wait, (mddev->sync_thread == NULL && @@ -7886,6 +7891,12 @@ static int md_thread(void *arg) return 0; } +static void md_wakeup_thread_directly(struct md_thread *thread) +{ + if (thread) + wake_up_process(thread->tsk); +} + void md_wakeup_thread(struct md_thread *thread) { if (thread) { From patchwork Sun Apr 2 09:12:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13197299 X-Patchwork-Delegate: song@kernel.org 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 D0E41C76196 for ; Sun, 2 Apr 2023 09:13:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230309AbjDBJNP (ORCPT ); Sun, 2 Apr 2023 05:13:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230295AbjDBJNL (ORCPT ); Sun, 2 Apr 2023 05:13:11 -0400 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78BAACC36; Sun, 2 Apr 2023 02:13:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Pq7bg22Y6z4f3lKM; Sun, 2 Apr 2023 17:13:03 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3X7MeRylkVUE8Gg--.50168S7; Sun, 02 Apr 2023 17:13:05 +0800 (CST) From: Yu Kuai To: logang@deltatee.com, song@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH v4 3/5] md: add a helper to access md_thread() directly Date: Sun, 2 Apr 2023 17:12:34 +0800 Message-Id: <20230402091236.976723-4-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230402091236.976723-1-yukuai1@huaweicloud.com> References: <20230402091236.976723-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3X7MeRylkVUE8Gg--.50168S7 X-Coremail-Antispam: 1UD129KBjvJXoWxuFy5tw18ZFWrWry5Jr4ktFb_yoWrCFy8pa yvqFyY9w48AFW3Zr1DAaykuFyFqwn2gF9rKryfC3yrC3W5G398Jry5CFyjyr1DZF1FyF43 tF15Kr48GF4vgr7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9v14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMxC20s 026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_ JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14 v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xva j40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JV W8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbJ73DUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai In some context it's safe to access md_thread directly without protection, this patch add a helper to do that. There are no functional changes, prepare to protect md_thread with rcu. Signed-off-by: Yu Kuai --- drivers/md/md-bitmap.c | 7 ++++--- drivers/md/md.c | 4 +++- drivers/md/md.h | 6 ++++++ drivers/md/raid10.c | 2 +- drivers/md/raid5-cache.c | 7 ++++--- 5 files changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index e7cc6ba1b657..f670c72d97be 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -1246,7 +1246,7 @@ void md_bitmap_daemon_work(struct mddev *mddev) bitmap->daemon_lastrun = jiffies; if (bitmap->allclean) { - mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; + get_md_thread(mddev->thread)->timeout = MAX_SCHEDULE_TIMEOUT; goto done; } bitmap->allclean = 1; @@ -1343,7 +1343,7 @@ void md_bitmap_daemon_work(struct mddev *mddev) done: if (bitmap->allclean == 0) - mddev->thread->timeout = + get_md_thread(mddev->thread)->timeout = mddev->bitmap_info.daemon_sleep; mutex_unlock(&mddev->bitmap_info.mutex); } @@ -1941,7 +1941,8 @@ int md_bitmap_load(struct mddev *mddev) /* Kick recovery in case any bits were set */ set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery); - mddev->thread->timeout = mddev->bitmap_info.daemon_sleep; + get_md_thread(mddev->thread)->timeout = + mddev->bitmap_info.daemon_sleep; md_wakeup_thread(mddev->thread); md_bitmap_update_sb(bitmap); diff --git a/drivers/md/md.c b/drivers/md/md.c index 139c7b0202e3..d5a29ccb24ec 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -458,7 +458,9 @@ static void md_submit_bio(struct bio *bio) */ void mddev_suspend(struct mddev *mddev) { - WARN_ON_ONCE(mddev->thread && current == mddev->thread->tsk); + struct md_thread *thread = get_md_thread(mddev->thread); + + WARN_ON_ONCE(thread && current == thread->tsk); lockdep_assert_held(&mddev->reconfig_mutex); if (mddev->suspended++) return; diff --git a/drivers/md/md.h b/drivers/md/md.h index 344e055e4d0f..5acdd704a922 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -718,6 +718,12 @@ struct md_io_acct { #define THREAD_WAKEUP 0 +/* caller need to make sured returned md_thread won't be freed */ +static inline struct md_thread *get_md_thread(struct md_thread *t) +{ + return t; +} + static inline void safe_put_page(struct page *p) { if (p) put_page(p); diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 0171ba4f19b0..fc8d07fb1c7d 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -996,7 +996,7 @@ static bool stop_waiting_barrier(struct r10conf *conf) return true; /* move on if recovery thread is blocked by us */ - if (conf->mddev->thread->tsk == current && + if (get_md_thread(conf->mddev->thread)->tsk == current && test_bit(MD_RECOVERY_RUNNING, &conf->mddev->recovery) && conf->nr_queued > 0) return true; diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 0464d4d551fc..7e45df3e093f 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1582,11 +1582,11 @@ void r5l_quiesce(struct r5l_log *log, int quiesce) /* make sure r5l_write_super_and_discard_space exits */ mddev = log->rdev->mddev; wake_up(&mddev->sb_wait); - kthread_park(log->reclaim_thread->tsk); + kthread_park(get_md_thread(log->reclaim_thread)->tsk); r5l_wake_reclaim(log, MaxSector); r5l_do_reclaim(log); } else - kthread_unpark(log->reclaim_thread->tsk); + kthread_unpark(get_md_thread(log->reclaim_thread)->tsk); } bool r5l_log_disk_error(struct r5conf *conf) @@ -3124,7 +3124,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) if (md_register_thread(&log->reclaim_thread, r5l_reclaim_thread, log->rdev->mddev, "reclaim")) goto reclaim_thread; - log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL; + get_md_thread(log->reclaim_thread)->timeout = + R5C_RECLAIM_WAKEUP_INTERVAL; init_waitqueue_head(&log->iounit_wait); From patchwork Sun Apr 2 09:12:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13197297 X-Patchwork-Delegate: song@kernel.org 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 EEF64C76196 for ; Sun, 2 Apr 2023 09:13:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230290AbjDBJNL (ORCPT ); Sun, 2 Apr 2023 05:13:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjDBJNK (ORCPT ); Sun, 2 Apr 2023 05:13:10 -0400 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 796ABCDCC; Sun, 2 Apr 2023 02:13:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Pq7bg4ghZz4f3lwR; Sun, 2 Apr 2023 17:13:03 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3X7MeRylkVUE8Gg--.50168S8; Sun, 02 Apr 2023 17:13:05 +0800 (CST) From: Yu Kuai To: logang@deltatee.com, song@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH v4 4/5] dm-raid: remove useless checking in raid_message() Date: Sun, 2 Apr 2023 17:12:35 +0800 Message-Id: <20230402091236.976723-5-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230402091236.976723-1-yukuai1@huaweicloud.com> References: <20230402091236.976723-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3X7MeRylkVUE8Gg--.50168S8 X-Coremail-Antispam: 1UD129KBjvdXoWrZrW7trWxXryfJF1fKFW8tFb_yoWfuwbEgF s5Zr9rXrnruw1fA3W2vw40vr90ywn5uF1kWF4rtFyayFy8KryrXryrurn8CwnrZFW7Cryj krWUCr4fCrn5CjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbT8FF20E14v26rWj6s0DM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAVCq3wA2048vs2 IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28E F7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJVW8Jr 1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI 8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwAC jcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1l42xK82IYc2Ij64vIr41l4I 8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AK xVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcV AFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8I cIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r 4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUOBTYUUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai md_wakeup_thread() handle the case that pass in md_thread is NULL, there is no need to checking this. Prepare to protect md_thread with rcu. Signed-off-by: Yu Kuai --- drivers/md/dm-raid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 60632b409b80..5c952a209214 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3754,11 +3754,11 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, * canceling read-auto mode */ mddev->ro = 0; - if (!mddev->suspended && mddev->sync_thread) + if (!mddev->suspended) md_wakeup_thread(mddev->sync_thread); } set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); - if (!mddev->suspended && mddev->thread) + if (!mddev->suspended) md_wakeup_thread(mddev->thread); return 0; From patchwork Sun Apr 2 09:12:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13197302 X-Patchwork-Delegate: song@kernel.org 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 1EB2FC77B6E for ; Sun, 2 Apr 2023 09:13:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbjDBJNR (ORCPT ); Sun, 2 Apr 2023 05:13:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230297AbjDBJNL (ORCPT ); Sun, 2 Apr 2023 05:13:11 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BBE2CDE2; Sun, 2 Apr 2023 02:13:08 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Pq7bh1mxDz4f3lY3; Sun, 2 Apr 2023 17:13:04 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3X7MeRylkVUE8Gg--.50168S9; Sun, 02 Apr 2023 17:13:05 +0800 (CST) From: Yu Kuai To: logang@deltatee.com, song@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH v4 5/5] md: protect md_thread with rcu Date: Sun, 2 Apr 2023 17:12:36 +0800 Message-Id: <20230402091236.976723-6-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230402091236.976723-1-yukuai1@huaweicloud.com> References: <20230402091236.976723-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3X7MeRylkVUE8Gg--.50168S9 X-Coremail-Antispam: 1UD129KBjvJXoWfJFWkWrWkXw13Zr18GrW3ZFb_yoWkZFW7p3 yxta43Ar4UArW5Zr1UAa4DCa4Yqw10qFWqyryfCw1rA3ZFg3y3JFy5GFyUZwn8AF15GFya q3W5KFZ8ur4DKF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9G14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr 1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0D M2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjx v20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1l F7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMx C20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAF wI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20x vE14v26r1I6r4UMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v2 0xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxV W8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbmZX7UUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai Our test reports a uaf for 'mddev->sync_thread': T1 T2 md_start_sync md_register_thread // mddev->sync_thread is set raid1d md_check_recovery md_reap_sync_thread md_unregister_thread kfree md_wakeup_thread wake_up ->sync_thread was freed Root cause is that there is a small windown between register thread and wake up thread, where the thread can be freed concurrently. Currently, a global spinlock 'pers_lock' is borrowed to protect 'mddev->thread', this problem can be fixed likewise, however, there might be similar problem for other md_thread, and I really don't like the idea to borrow a global lock. This patch protect md_thread with rcu. Signed-off-by: Yu Kuai --- drivers/md/md-bitmap.c | 21 ++++++++++---- drivers/md/md.c | 62 ++++++++++++++++++---------------------- drivers/md/md.h | 14 ++++----- drivers/md/raid1.c | 4 +-- drivers/md/raid1.h | 2 +- drivers/md/raid10.c | 4 +-- drivers/md/raid10.h | 2 +- drivers/md/raid5-cache.c | 2 +- drivers/md/raid5.c | 4 +-- drivers/md/raid5.h | 2 +- 10 files changed, 61 insertions(+), 56 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index f670c72d97be..dc2ea2ce0ae9 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -1784,6 +1784,7 @@ void md_bitmap_wait_behind_writes(struct mddev *mddev) void md_bitmap_destroy(struct mddev *mddev) { struct bitmap *bitmap = mddev->bitmap; + struct md_thread *thread; if (!bitmap) /* there was no bitmap */ return; @@ -1797,8 +1798,12 @@ void md_bitmap_destroy(struct mddev *mddev) mddev->bitmap = NULL; /* disconnect from the md device */ spin_unlock(&mddev->lock); mutex_unlock(&mddev->bitmap_info.mutex); - if (mddev->thread) - mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; + + rcu_read_lock(); + thread = rcu_dereference(mddev->thread); + if (thread) + thread->timeout = MAX_SCHEDULE_TIMEOUT; + rcu_read_unlock(); md_bitmap_free(bitmap); } @@ -2433,6 +2438,7 @@ timeout_store(struct mddev *mddev, const char *buf, size_t len) { /* timeout can be set at any time */ unsigned long timeout; + struct md_thread *thread; int rv = strict_strtoul_scaled(buf, &timeout, 4); if (rv) return rv; @@ -2448,16 +2454,21 @@ timeout_store(struct mddev *mddev, const char *buf, size_t len) if (timeout < 1) timeout = 1; mddev->bitmap_info.daemon_sleep = timeout; - if (mddev->thread) { + + rcu_read_lock(); + thread = rcu_dereference(mddev->thread); + if (thread) { /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then * the bitmap is all clean and we don't need to * adjust the timeout right now */ - if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) { - mddev->thread->timeout = timeout; + if (thread->timeout < MAX_SCHEDULE_TIMEOUT) { + thread->timeout = timeout; md_wakeup_thread(mddev->thread); } } + rcu_read_unlock(); + return len; } diff --git a/drivers/md/md.c b/drivers/md/md.c index d5a29ccb24ec..5609b7e3abab 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -70,11 +70,7 @@ #include "md-bitmap.h" #include "md-cluster.h" -/* pers_list is a list of registered personalities protected - * by pers_lock. - * pers_lock does extra service to protect accesses to - * mddev->thread when the mutex cannot be held. - */ +/* pers_list is a list of registered personalities protected by pers_lock. */ static LIST_HEAD(pers_list); static DEFINE_SPINLOCK(pers_lock); @@ -92,7 +88,7 @@ static struct workqueue_struct *md_rdev_misc_wq; static int remove_and_add_spares(struct mddev *mddev, struct md_rdev *this); static void mddev_detach(struct mddev *mddev); -static void md_wakeup_thread_directly(struct md_thread *thread); +static void md_wakeup_thread_directly(struct md_thread __rcu *thread); enum md_ro_state { MD_RDWR, @@ -803,13 +799,8 @@ void mddev_unlock(struct mddev *mddev) } else mutex_unlock(&mddev->reconfig_mutex); - /* As we've dropped the mutex we need a spinlock to - * make sure the thread doesn't disappear - */ - spin_lock(&pers_lock); md_wakeup_thread(mddev->thread); wake_up(&mddev->sb_wait); - spin_unlock(&pers_lock); } EXPORT_SYMBOL_GPL(mddev_unlock); @@ -7893,23 +7884,33 @@ static int md_thread(void *arg) return 0; } -static void md_wakeup_thread_directly(struct md_thread *thread) +static void md_wakeup_thread_directly(struct md_thread __rcu *thread) { - if (thread) - wake_up_process(thread->tsk); + struct md_thread *t; + + rcu_read_lock(); + t = rcu_dereference(thread); + if (t) + wake_up_process(t->tsk); + rcu_read_unlock(); } -void md_wakeup_thread(struct md_thread *thread) +void md_wakeup_thread(struct md_thread __rcu *thread) { - if (thread) { - pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm); - set_bit(THREAD_WAKEUP, &thread->flags); - wake_up(&thread->wqueue); + struct md_thread *t; + + rcu_read_lock(); + t = rcu_dereference(thread); + if (t) { + pr_debug("md: waking up MD thread %s.\n", t->tsk->comm); + set_bit(THREAD_WAKEUP, &t->flags); + wake_up(&t->wqueue); } + rcu_read_unlock(); } EXPORT_SYMBOL(md_wakeup_thread); -int md_register_thread(struct md_thread **threadp, +int md_register_thread(struct md_thread __rcu **threadp, void (*run)(struct md_thread *), struct mddev *mddev, const char *name) { @@ -7933,27 +7934,20 @@ int md_register_thread(struct md_thread **threadp, return err; } - *threadp = thread; + rcu_assign_pointer(*threadp, thread); return 0; } EXPORT_SYMBOL(md_register_thread); -void md_unregister_thread(struct md_thread **threadp) +void md_unregister_thread(struct md_thread __rcu **threadp) { - struct md_thread *thread; + struct md_thread *thread = rcu_access_pointer(*threadp); - /* - * Locking ensures that mddev_unlock does not wake_up a - * non-existent thread - */ - spin_lock(&pers_lock); - thread = *threadp; - if (!thread) { - spin_unlock(&pers_lock); + if (!thread) return; - } - *threadp = NULL; - spin_unlock(&pers_lock); + + rcu_assign_pointer(*threadp, NULL); + synchronize_rcu(); pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk)); kthread_stop(thread->tsk); diff --git a/drivers/md/md.h b/drivers/md/md.h index 5acdd704a922..0525f6d66a4d 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -367,8 +367,8 @@ struct mddev { int new_chunk_sectors; int reshape_backwards; - struct md_thread *thread; /* management thread */ - struct md_thread *sync_thread; /* doing resync or reconstruct */ + struct md_thread __rcu *thread; /* management thread */ + struct md_thread __rcu *sync_thread; /* doing resync or reconstruct */ /* 'last_sync_action' is initialized to "none". It is set when a * sync operation (i.e "data-check", "requested-resync", "resync", @@ -719,9 +719,9 @@ struct md_io_acct { #define THREAD_WAKEUP 0 /* caller need to make sured returned md_thread won't be freed */ -static inline struct md_thread *get_md_thread(struct md_thread *t) +static inline struct md_thread *get_md_thread(struct md_thread __rcu *t) { - return t; + return rcu_access_pointer(t); } static inline void safe_put_page(struct page *p) @@ -736,11 +736,11 @@ extern int register_md_cluster_operations(struct md_cluster_operations *ops, extern int unregister_md_cluster_operations(void); extern int md_setup_cluster(struct mddev *mddev, int nodes); extern void md_cluster_stop(struct mddev *mddev); -int md_register_thread(struct md_thread **threadp, +int md_register_thread(struct md_thread __rcu **threadp, void (*run)(struct md_thread *thread), struct mddev *mddev, const char *name); -extern void md_unregister_thread(struct md_thread **threadp); -extern void md_wakeup_thread(struct md_thread *thread); +extern void md_unregister_thread(struct md_thread __rcu **threadp); +extern void md_wakeup_thread(struct md_thread __rcu *thread); extern void md_check_recovery(struct mddev *mddev); extern void md_reap_sync_thread(struct mddev *mddev); extern int mddev_init_writes_pending(struct mddev *mddev); diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 1217c1db0a40..64f019e3615f 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -3176,8 +3176,8 @@ static int raid1_run(struct mddev *mddev) /* * Ok, everything is just fine now */ - mddev->thread = conf->thread; - conf->thread = NULL; + rcu_assign_pointer(mddev->thread, conf->thread); + rcu_assign_pointer(conf->thread, NULL); mddev->private = conf; set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags); diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h index ebb6788820e7..468f189da7a0 100644 --- a/drivers/md/raid1.h +++ b/drivers/md/raid1.h @@ -130,7 +130,7 @@ struct r1conf { /* When taking over an array from a different personality, we store * the new thread here until we fully activate the array. */ - struct md_thread *thread; + struct md_thread __rcu *thread; /* Keep track of cluster resync window to send to other * nodes. diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index fc8d07fb1c7d..5509955b79ec 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -4140,8 +4140,8 @@ static int raid10_run(struct mddev *mddev) } } - mddev->thread = conf->thread; - conf->thread = NULL; + rcu_assign_pointer(mddev->thread, conf->thread); + rcu_assign_pointer(conf->thread, NULL); if (mddev->queue) { blk_queue_max_write_zeroes_sectors(mddev->queue, 0); diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h index 8c072ce0bc54..63e48b11b552 100644 --- a/drivers/md/raid10.h +++ b/drivers/md/raid10.h @@ -100,7 +100,7 @@ struct r10conf { /* When taking over an array from a different personality, we store * the new thread here until we fully activate the array. */ - struct md_thread *thread; + struct md_thread __rcu *thread; /* * Keep track of cluster resync window to send to other nodes. diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 7e45df3e093f..b677441d8889 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -120,7 +120,7 @@ struct r5l_log { struct bio_set bs; mempool_t meta_pool; - struct md_thread *reclaim_thread; + struct md_thread __rcu *reclaim_thread; unsigned long reclaim_target; /* number of space that need to be * reclaimed. if it's 0, reclaim spaces * used by io_units which are in diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 04b1093195d0..a7e47c37daf3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7888,8 +7888,8 @@ static int raid5_run(struct mddev *mddev) } conf->min_offset_diff = min_offset_diff; - mddev->thread = conf->thread; - conf->thread = NULL; + rcu_assign_pointer(mddev->thread, conf->thread); + rcu_assign_pointer(conf->thread, NULL); mddev->private = conf; for (i = 0; i < conf->raid_disks && conf->previous_raid_disks; diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index e873938a6125..f19707189a7b 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -679,7 +679,7 @@ struct r5conf { /* When taking over an array from a different personality, we store * the new thread here until we fully activate the array. */ - struct md_thread *thread; + struct md_thread __rcu *thread; struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS]; struct r5worker_group *worker_groups; int group_cnt;