From patchwork Thu Apr 15 01:50:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 422127 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 683C3C433ED for ; Thu, 15 Apr 2021 01:50:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4415B6120E for ; Thu, 15 Apr 2021 01:50:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229481AbhDOBvH (ORCPT ); Wed, 14 Apr 2021 21:51:07 -0400 Received: from smtp.infotech.no ([82.134.31.41]:33139 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229458AbhDOBvH (ORCPT ); Wed, 14 Apr 2021 21:51:07 -0400 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 69C4920423A; Thu, 15 Apr 2021 03:50:43 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ady2RQB76u14; Thu, 15 Apr 2021 03:50:35 +0200 (CEST) Received: from xtwo70.bingwo.ca (host-45-58-219-4.dyn.295.ca [45.58.219.4]) by smtp.infotech.no (Postfix) with ESMTPA id 05007204191; Thu, 15 Apr 2021 03:50:33 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, kashyap.desai@broadcom.com, ming.lei@redhat.com, john.garry@huawei.com, axboe@kernel.dk Subject: [PATCH] scsi_debug: fix cmd_per_lun, set to max_queue Date: Wed, 14 Apr 2021 21:50:31 -0400 Message-Id: <20210415015031.607153-1-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Make sure that the cmd_per_lun value placed in the host template never exceeds the can_queue value. If the max_queue driver parameter is not specified then both cmd_per_lun and can_queue are set to CAN_QUEUE. CAN_QUEUE is a compile time constant and is used to dimension an array to hold queued requests. If the max_queue driver parameter is given it is must be less than or equal to CAN_QUEUE and if so, the host template values are adjusted. Remove undocumented code that allowed queue_depth to exceed CAN_QUEUE and cause stack full type errors. There is a documented way to do that with every_nth and echo 0x8000 > /sys/bus/pseudo/drivers/scsi_debug/opts See: https://sg.danny.cz/sg/scsi_debug.html Tweak some formatting, and add a suggestion to the "trim poll_queues" warning. Reported-by: Kashyap Desai Signed-off-by: Douglas Gilbert Signed-off-by: John Garry Reviewed-by: John Garry --- drivers/scsi/scsi_debug.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 70165be10f00..a5d1633b5bd8 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -218,7 +218,7 @@ static const char *sdebug_version_date = "20200710"; */ #define SDEBUG_CANQUEUE_WORDS 3 /* a WORD is bits in a long */ #define SDEBUG_CANQUEUE (SDEBUG_CANQUEUE_WORDS * BITS_PER_LONG) -#define DEF_CMD_PER_LUN 255 +#define DEF_CMD_PER_LUN SDEBUG_CANQUEUE /* UA - Unit Attention; SA - Service Action; SSU - Start Stop Unit */ #define F_D_IN 1 /* Data-in command (e.g. READ) */ @@ -5695,8 +5695,8 @@ MODULE_PARM_DESC(lbpu, "enable LBP, support UNMAP command (def=0)"); MODULE_PARM_DESC(lbpws, "enable LBP, support WRITE SAME(16) with UNMAP bit (def=0)"); MODULE_PARM_DESC(lbpws10, "enable LBP, support WRITE SAME(10) with UNMAP bit (def=0)"); MODULE_PARM_DESC(lowest_aligned, "lowest aligned lba (def=0)"); -MODULE_PARM_DESC(max_luns, "number of LUNs per target to simulate(def=1)"); MODULE_PARM_DESC(lun_format, "LUN format: 0->peripheral (def); 1 --> flat address method"); +MODULE_PARM_DESC(max_luns, "number of LUNs per target to simulate(def=1)"); MODULE_PARM_DESC(max_queue, "max number of queued commands (1 to max(def))"); MODULE_PARM_DESC(medium_error_count, "count of sectors to return follow on MEDIUM error"); MODULE_PARM_DESC(medium_error_start, "starting sector number to return MEDIUM error"); @@ -5710,7 +5710,7 @@ MODULE_PARM_DESC(opt_xferlen_exp, "optimal transfer length granularity exponent MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)"); MODULE_PARM_DESC(per_host_store, "If set, next positive add_host will get new store (def=0)"); MODULE_PARM_DESC(physblk_exp, "physical block exponent (def=0)"); -MODULE_PARM_DESC(poll_queues, "support for iouring iopoll queues (1 to max(submit_queues - 1)"); +MODULE_PARM_DESC(poll_queues, "support for iouring iopoll queues (1 to max(submit_queues - 1))"); MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])"); MODULE_PARM_DESC(random, "If set, uniformly randomize command duration between 0 and delay_in_ns"); MODULE_PARM_DESC(removable, "claim to have removable media (def=0)"); @@ -7165,12 +7165,15 @@ static int sdebug_change_qdepth(struct scsi_device *sdev, int qdepth) } num_in_q = atomic_read(&devip->num_in_q); + if (qdepth > SDEBUG_CANQUEUE) { + qdepth = SDEBUG_CANQUEUE; + pr_warn("%s: requested qdepth [%d] exceeds canqueue [%d], trim\n", __func__, + qdepth, SDEBUG_CANQUEUE); + } if (qdepth < 1) qdepth = 1; - /* allow to exceed max host qc_arr elements for testing */ - if (qdepth > SDEBUG_CANQUEUE + 10) - qdepth = SDEBUG_CANQUEUE + 10; - scsi_change_queue_depth(sdev, qdepth); + if (qdepth != sdev->queue_depth) + scsi_change_queue_depth(sdev, qdepth); if (SDEBUG_OPT_Q_NOISE & sdebug_opts) { sdev_printk(KERN_INFO, sdev, "%s: qdepth=%d, num_in_q=%d\n", @@ -7558,6 +7561,7 @@ static int sdebug_driver_probe(struct device *dev) sdbg_host = to_sdebug_host(dev); sdebug_driver_template.can_queue = sdebug_max_queue; + sdebug_driver_template.cmd_per_lun = sdebug_max_queue; if (!sdebug_clustering) sdebug_driver_template.dma_boundary = PAGE_SIZE - 1; @@ -7593,7 +7597,11 @@ static int sdebug_driver_probe(struct device *dev) * If condition not met, trim poll_queues to 1 (just for simplicity). */ if (poll_queues >= submit_queues) { - pr_warn("%s: trim poll_queues to 1\n", my_name); + if (submit_queues < 3) + pr_warn("%s: trim poll_queues to 1\n", my_name); + else + pr_warn("%s: trim poll_queues to 1. Perhaps try poll_queues=%d\n", + my_name, submit_queues - 1); poll_queues = 1; } if (poll_queues)