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 541E9210C0E; Wed, 23 Oct 2024 14:32:27 +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=1729693947; cv=none; b=O1d+6QnNU2JF/TG8qQ5aUc1TRWYdzOLiDQzYaROMOaxJ/txHXYVbb2mJ59KE34SIbl5cBxXC2gDctHxAlT/yO3MNwF7ON/e8WhC75iqYurrcnKSCQPVvj9qQ5RVA4xrtHM6mwENGTs/uNRLeJw5M2/07WRh5nPc1K6WdHSSJQfk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729693947; c=relaxed/simple; bh=l8kydYeUsOiZtm3dihKoja2wxm6KX1Xk3/XsqqFT4EM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e/zpZs9EykaILprLfo8I7jMLFqXOisqxlv50edKiWJNOpXEPgqHVlIjwqpuDT5YUxHJZOVETaXWxdQTWfiWIZbUM9aZ/T64XEOg/g4bWQ1ul7qZx459c4UG9U3cLWFCwidJmc9kumElh/RL78ls+3NQT+8+EYorRmo5K8MbjBaw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rROSW2uB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rROSW2uB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41A0CC4CEE4; Wed, 23 Oct 2024 14:32:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729693947; bh=l8kydYeUsOiZtm3dihKoja2wxm6KX1Xk3/XsqqFT4EM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rROSW2uBO7QmfGFTSC0nEj7W19EfvGUzzTep1Qo64arkWbLW5u2hqnUCNzGM6j9/o IPLqEEDP7hR+JIPm9q+mJhQYB4YLkxwbalx8csKWX/OeTuDSMa8I4Otcp2nXVUDA+q Gp6MZIH20MGWInFOZRauifbIWDKO8j1Y46AI3EAlYg9OLpIjncNn+nRWYoFviyUpMH L64kRi9nD71f8iq0h+luUgC5Tj+5pUHYs+feequqGAPoIoIZcZOpY51+Sr5HBmBhyY 9jJYEiqaOFJDX8uJSFrLYiwUAw99BkGVy5t68k4TkeHt7Y4/lQW9yq/xaExLtZX3Sk BTxN0pz5ImlZQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Keith Busch , Hannes Reinecke , Christoph Hellwig , Sasha Levin , sagi@grimberg.me, linux-nvme@lists.infradead.org Subject: [PATCH AUTOSEL 6.1 15/17] nvme-multipath: defer partition scanning Date: Wed, 23 Oct 2024 10:31:54 -0400 Message-ID: <20241023143202.2981992-15-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241023143202.2981992-1-sashal@kernel.org> References: <20241023143202.2981992-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.114 Content-Transfer-Encoding: 8bit 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 93ada8941a4c5..43b89c7d585f0 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -463,6 +463,20 @@ 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 = @@ -489,6 +503,7 @@ 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. @@ -504,6 +519,16 @@ 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); @@ -552,6 +577,7 @@ 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); @@ -851,6 +877,12 @@ 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); } } @@ -862,6 +894,7 @@ 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 5f8a146b70148..0f49b779dec65 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -460,6 +460,7 @@ 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