From patchwork Mon Feb 21 08:49:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 544805 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 C28C2C433FE for ; Mon, 21 Feb 2022 09:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349946AbiBUJ36 (ORCPT ); Mon, 21 Feb 2022 04:29:58 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:51996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349304AbiBUJ2r (ORCPT ); Mon, 21 Feb 2022 04:28:47 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DB54240A2; Mon, 21 Feb 2022 01:12:58 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id BE9D9CE0E79; Mon, 21 Feb 2022 09:12:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC855C340E9; Mon, 21 Feb 2022 09:12:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645434775; bh=SK0woKC69aS1dpqIlWjbdHwaagPL1JG3IRZDlQJKPpE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MInopzXv/njEdN/Jd0UCf5TwgpFJKAOfjcRuewGE5YFCxsCv2ybbJmHxGdFNDdFJL cJthextqUH6iEvTYm7Jg+Z5piEEjUAWxQFAV1fOq/GJouBWC3TPy+msidFF/+xNw2s EXTNbP3I9tjxGtdNn6Z3cdSuU4OWLUapAsjnyYIo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bean Huo , Adrian Hunter , Bart Van Assche , "Martin K. Petersen" Subject: [PATCH 5.15 127/196] scsi: ufs: Fix a deadlock in the error handler Date: Mon, 21 Feb 2022 09:49:19 +0100 Message-Id: <20220221084935.189662360@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220221084930.872957717@linuxfoundation.org> References: <20220221084930.872957717@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bart Van Assche commit 945c3cca05d78351bba29fa65d93834cb7934c7b upstream. The following deadlock has been observed on a test setup: - All tags allocated - The SCSI error handler calls ufshcd_eh_host_reset_handler() - ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler() - ufshcd_err_handler() locks up as follows: Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt Call trace: __switch_to+0x298/0x5d8 __schedule+0x6cc/0xa94 schedule+0x12c/0x298 blk_mq_get_tag+0x210/0x480 __blk_mq_alloc_request+0x1c8/0x284 blk_get_request+0x74/0x134 ufshcd_exec_dev_cmd+0x68/0x640 ufshcd_verify_dev_init+0x68/0x35c ufshcd_probe_hba+0x12c/0x1cb8 ufshcd_host_reset_and_restore+0x88/0x254 ufshcd_reset_and_restore+0xd0/0x354 ufshcd_err_handler+0x408/0xc58 process_one_work+0x24c/0x66c worker_thread+0x3e8/0xa4c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved request. Link: https://lore.kernel.org/r/20211203231950.193369-10-bvanassche@acm.org Tested-by: Bean Huo Reviewed-by: Adrian Hunter Reviewed-by: Bean Huo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/ufs/ufshcd.c | 53 ++++++++++++---------------------------------- drivers/scsi/ufs/ufshcd.h | 2 + 2 files changed, 16 insertions(+), 39 deletions(-) --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -125,8 +125,9 @@ EXPORT_SYMBOL_GPL(ufshcd_dump_regs); enum { UFSHCD_MAX_CHANNEL = 0, UFSHCD_MAX_ID = 1, - UFSHCD_CMD_PER_LUN = 32, - UFSHCD_CAN_QUEUE = 32, + UFSHCD_NUM_RESERVED = 1, + UFSHCD_CMD_PER_LUN = 32 - UFSHCD_NUM_RESERVED, + UFSHCD_CAN_QUEUE = 32 - UFSHCD_NUM_RESERVED, }; /* UFSHCD error handling flags */ @@ -2185,6 +2186,7 @@ static inline int ufshcd_hba_capabilitie hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1; hba->nutmrs = ((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1; + hba->reserved_slot = hba->nutrs - 1; /* Read crypto capabilities */ err = ufshcd_hba_init_crypto_capabilities(hba); @@ -2910,30 +2912,15 @@ static int ufshcd_wait_for_dev_cmd(struc static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, int timeout) { - struct request_queue *q = hba->cmd_queue; DECLARE_COMPLETION_ONSTACK(wait); - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err; - int tag; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - /* - * Get free slot, sleep if slots are unavailable. - * Even though we use wait_event() which sleeps indefinitely, - * the maximum wait time is bounded by SCSI request timeout. - */ - req = blk_get_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); - /* Set the timeout such that the SCSI error handler is not activated. */ - req->timeout = msecs_to_jiffies(2 * timeout); - blk_mq_start_request(req); + down_read(&hba->clk_scaling_lock); lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); @@ -2951,8 +2938,6 @@ static int ufshcd_exec_dev_cmd(struct uf (struct utp_upiu_req *)lrbp->ucd_rsp_ptr); out: - blk_put_request(req); -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -6640,23 +6625,16 @@ static int ufshcd_issue_devman_upiu_cmd( enum dev_cmd_type cmd_type, enum query_opcode desc_op) { - struct request_queue *q = hba->cmd_queue; DECLARE_COMPLETION_ONSTACK(wait); - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err = 0; - int tag; u8 upiu_flags; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - req = blk_get_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); + down_read(&hba->clk_scaling_lock); lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); @@ -6725,9 +6703,6 @@ static int ufshcd_issue_devman_upiu_cmd( ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR : UFS_QUERY_COMP, (struct utp_upiu_req *)lrbp->ucd_rsp_ptr); - blk_put_request(req); - -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -9418,8 +9393,8 @@ int ufshcd_init(struct ufs_hba *hba, voi /* Configure LRB */ ufshcd_host_memory_configure(hba); - host->can_queue = hba->nutrs; - host->cmd_per_lun = hba->nutrs; + host->can_queue = hba->nutrs - UFSHCD_NUM_RESERVED; + host->cmd_per_lun = hba->nutrs - UFSHCD_NUM_RESERVED; host->max_id = UFSHCD_MAX_ID; host->max_lun = UFS_MAX_LUNS; host->max_channel = UFSHCD_MAX_CHANNEL; --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -725,6 +725,7 @@ struct ufs_hba_monitor { * @capabilities: UFS Controller Capabilities * @nutrs: Transfer Request Queue depth supported by controller * @nutmrs: Task Management Queue depth supported by controller + * @reserved_slot: Used to submit device commands. Protected by @dev_cmd.lock. * @ufs_version: UFS Version to which controller complies * @vops: pointer to variant specific operations * @priv: pointer to variant specific private data @@ -813,6 +814,7 @@ struct ufs_hba { u32 capabilities; int nutrs; int nutmrs; + u32 reserved_slot; u32 ufs_version; const struct ufs_hba_variant_ops *vops; struct ufs_hba_variant_params *vps;