From patchwork Mon Jan 8 18:50:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 10150299 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D707460210 for ; Mon, 8 Jan 2018 18:50:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E3BE9289D7 for ; Mon, 8 Jan 2018 18:50:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D7A82289DF; Mon, 8 Jan 2018 18:50:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CB9C8289D7 for ; Mon, 8 Jan 2018 18:50:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755930AbeAHSuV (ORCPT ); Mon, 8 Jan 2018 13:50:21 -0500 Received: from esa4.hgst.iphmx.com ([216.71.154.42]:60235 "EHLO esa4.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406AbeAHSuT (ORCPT ); Mon, 8 Jan 2018 13:50:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1515437420; x=1546973420; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=L4QsEyYsp4fFZUejcs7BBlvmbsdQYuWvp8n7SfsDMv8=; b=JNYp6dCHYwk7qtn/SXzwDPVCsf4MdNkFjr62eqg7zPv9y+2C7rCGdS8S 6zoF0D/h9cYqvgZaH2yy1Q9fpevX80KZmuuXGvgsYhaqTCwbKZZ6+rYc2 db3AX4q9e19uf/ZAOu3hLSvEEeIa+AjRhttN+RoZGwqwVdd9qjBTkhyPa WH25STla4E7v8QZm8CsHinAXGcfYwjIBIX0NlcWYokdE7NeSYEzUN35yA NZcj0vjPnreu7PlfruDyJWA/WDcY+oA10fX3mVUDlk44pnmVp4U4cUqa9 +K3LpctDztins03fVFuNwW4Bv8nC2nQkTPrY4y/wtzKAcoxEzs+mHq1nT A==; X-IronPort-AV: E=Sophos;i="5.46,332,1511798400"; d="scan'208";a="68074227" Received: from uls-op-cesaip02.wdc.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 09 Jan 2018 02:50:13 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP; 08 Jan 2018 10:45:48 -0800 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.171.236]) by uls-op-cesaip02.wdc.com with ESMTP; 08 Jan 2018 10:50:13 -0800 From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, "Martin K . Petersen" , Christoph Hellwig , Jason Gunthorpe , Doug Ledford , linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, Bart Van Assche Subject: [PATCH 4/4] IB/srp: Fix a sleep-in-invalid-context bug Date: Mon, 8 Jan 2018 10:50:11 -0800 Message-Id: <20180108185011.30018-5-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180108185011.30018-1-bart.vanassche@wdc.com> References: <20180108185011.30018-1-bart.vanassche@wdc.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The previous two patches guarantee that srp_queuecommand() does not get invoked while reconnecting occurs. Hence remove the code from srp_queuecommand() that prevents command queueing while reconnecting. This patch avoids that the following can appear in the kernel log: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 5600, name: scsi_eh_9 1 lock held by scsi_eh_9/5600: #0: (rcu_read_lock){....}, at: [<00000000cbb798c7>] __blk_mq_run_hw_queue+0xf1/0x1e0 Preemption disabled at: [<00000000139badf2>] __blk_mq_delay_run_hw_queue+0x78/0xf0 CPU: 9 PID: 5600 Comm: scsi_eh_9 Tainted: G W 4.15.0-rc4-dbg+ #1 Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.5.4 01/22/2016 Call Trace: dump_stack+0x67/0x99 ___might_sleep+0x16a/0x250 [ib_srp] __mutex_lock+0x46/0x9d0 srp_queuecommand+0x356/0x420 [ib_srp] scsi_dispatch_cmd+0xf6/0x3f0 scsi_queue_rq+0x4a8/0x5f0 blk_mq_dispatch_rq_list+0x73/0x440 blk_mq_sched_dispatch_requests+0x109/0x1a0 __blk_mq_run_hw_queue+0x131/0x1e0 __blk_mq_delay_run_hw_queue+0x9a/0xf0 blk_mq_run_hw_queue+0xc0/0x1e0 blk_mq_start_hw_queues+0x2c/0x40 scsi_run_queue+0x18e/0x2d0 scsi_run_host_queues+0x22/0x40 scsi_error_handler+0x18d/0x5f0 kthread+0x11c/0x140 ret_from_fork+0x24/0x30 Signed-off-by: Bart Van Assche Cc: Jason Gunthorpe Cc: Doug Ledford Reviewed-by: Hannes Reinecke --- drivers/infiniband/ulp/srp/ib_srp.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 972d4b3c5223..670f187ecb91 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -2149,7 +2149,6 @@ static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc, static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) { struct srp_target_port *target = host_to_target(shost); - struct srp_rport *rport = target->rport; struct srp_rdma_ch *ch; struct srp_request *req; struct srp_iu *iu; @@ -2159,16 +2158,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) u32 tag; u16 idx; int len, ret; - const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler; - - /* - * The SCSI EH thread is the only context from which srp_queuecommand() - * can get invoked for blocked devices (SDEV_BLOCK / - * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by - * locking the rport mutex if invoked from inside the SCSI EH. - */ - if (in_scsi_eh) - mutex_lock(&rport->mutex); scmnd->result = srp_chkready(target->rport); if (unlikely(scmnd->result)) @@ -2230,13 +2219,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) goto err_unmap; } - ret = 0; - -unlock_rport: - if (in_scsi_eh) - mutex_unlock(&rport->mutex); - - return ret; + return 0; err_unmap: srp_unmap_data(scmnd, ch, req); @@ -2258,7 +2241,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) ret = SCSI_MLQUEUE_HOST_BUSY; } - goto unlock_rport; + return ret; } /*