From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8C416EAD0; Fri, 15 Nov 2024 06:50:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731653422; cv=none; b=CQWNpK6UtTCF5z4yBgkdsk+r8aN+fe9u9LVt0P+h85varFL7vVAYoOvJ4tA2QaABEN1ozrIMtZGXLpetMvtxchAIMt/8nu7AGq4bhz4ppGkc8n8arRe1/DsDWtVJ4GMnXUf0OMv1VFyFyOoSrQ2OreBg8zuuthNBEDaTwelXQH8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731653422; c=relaxed/simple; bh=it5nsr6uh6OoXlvjZo4B1z4fHnt5yXyj6hO8LJvZyZ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ikiKZiASxsi/rogBfP8laY6M/HVcUl4XMDy05hsMuQK0WprSNj2aWTZYiboN3mKR1jlRLZEanQvSqLArXg82y8frvM3gx/TsurPlRQ8/E3iHV8Dvxvif/Dkuf9wDbRXMbNLiJLN0on4/y4mJ6P748p9heFlCjd58BuxadOtEV3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wOby+qNI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wOby+qNI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED72AC4CECF; Fri, 15 Nov 2024 06:50:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731653422; bh=it5nsr6uh6OoXlvjZo4B1z4fHnt5yXyj6hO8LJvZyZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wOby+qNIoGEBKwBVjdpqrsNFDFm/y787BTon7xWHzIo+5K6q6vwNGNQU0iozzw2Yl WzY7nqfws05OimHQtIVIz9klYevVCvb23TpGhI5cDk6UdmCfpPfIWpHk1kEUZrYW2c YYiaHf1PPypiq3m1RTqR+GUE7Af1QK1VaJedkdq8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hannes Reinecke , Christoph Hellwig , Keith Busch , Sasha Levin Subject: [PATCH 6.6 18/48] nvme-multipath: defer partition scanning Date: Fri, 15 Nov 2024 07:38:07 +0100 Message-ID: <20241115063723.621886625@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241115063722.962047137@linuxfoundation.org> References: <20241115063722.962047137@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Keith Busch [ Upstream commit 1f021341eef41e77a633186e9be5223de2ce5d48 ] We need to suppress the partition scan from occuring within the controller's scan_work context. If a path error occurs here, the IO will wait until a path becomes available or all paths are torn down, but that action also occurs within scan_work, so it would deadlock. Defer the partion scan to a different context that does not block scan_work. Reported-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Sasha Levin --- drivers/nvme/host/multipath.c | 33 +++++++++++++++++++++++++++++++++ drivers/nvme/host/nvme.h | 1 + 2 files changed, 34 insertions(+) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 37ea0fa421da8..ede2a14dad8be 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -499,6 +499,20 @@ static int nvme_add_ns_head_cdev(struct nvme_ns_head *head) return ret; } +static void nvme_partition_scan_work(struct work_struct *work) +{ + struct nvme_ns_head *head = + container_of(work, struct nvme_ns_head, partition_scan_work); + + if (WARN_ON_ONCE(!test_and_clear_bit(GD_SUPPRESS_PART_SCAN, + &head->disk->state))) + return; + + mutex_lock(&head->disk->open_mutex); + bdev_disk_changed(head->disk, false); + mutex_unlock(&head->disk->open_mutex); +} + static void nvme_requeue_work(struct work_struct *work) { struct nvme_ns_head *head = @@ -525,6 +539,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) bio_list_init(&head->requeue_list); spin_lock_init(&head->requeue_lock); INIT_WORK(&head->requeue_work, nvme_requeue_work); + INIT_WORK(&head->partition_scan_work, nvme_partition_scan_work); /* * Add a multipath node if the subsystems supports multiple controllers. @@ -540,6 +555,16 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) return -ENOMEM; head->disk->fops = &nvme_ns_head_ops; head->disk->private_data = head; + + /* + * We need to suppress the partition scan from occuring within the + * controller's scan_work context. If a path error occurs here, the IO + * will wait until a path becomes available or all paths are torn down, + * but that action also occurs within scan_work, so it would deadlock. + * Defer the partion scan to a different context that does not block + * scan_work. + */ + set_bit(GD_SUPPRESS_PART_SCAN, &head->disk->state); sprintf(head->disk->disk_name, "nvme%dn%d", ctrl->subsys->instance, head->instance); @@ -589,6 +614,7 @@ static void nvme_mpath_set_live(struct nvme_ns *ns) return; } nvme_add_ns_head_cdev(head); + kblockd_schedule_work(&head->partition_scan_work); } mutex_lock(&head->lock); @@ -889,6 +915,12 @@ void nvme_mpath_shutdown_disk(struct nvme_ns_head *head) kblockd_schedule_work(&head->requeue_work); if (test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { nvme_cdev_del(&head->cdev, &head->cdev_device); + /* + * requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared + * to allow multipath to fail all I/O. + */ + synchronize_srcu(&head->srcu); + kblockd_schedule_work(&head->requeue_work); del_gendisk(head->disk); } } @@ -900,6 +932,7 @@ void nvme_mpath_remove_disk(struct nvme_ns_head *head) /* make sure all pending bios are cleaned up */ kblockd_schedule_work(&head->requeue_work); flush_work(&head->requeue_work); + flush_work(&head->partition_scan_work); put_disk(head->disk); } diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 799f8a2bb0b4f..14a867245c29f 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -476,6 +476,7 @@ struct nvme_ns_head { struct bio_list requeue_list; spinlock_t requeue_lock; struct work_struct requeue_work; + struct work_struct partition_scan_work; struct mutex lock; unsigned long flags; #define NVME_NSHEAD_DISK_LIVE 0 -- 2.43.0