From patchwork Mon Oct 23 21:53:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 13433607 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 98890C00A8F for ; Mon, 23 Oct 2023 21:57:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233420AbjJWV5G (ORCPT ); Mon, 23 Oct 2023 17:57:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232738AbjJWV5D (ORCPT ); Mon, 23 Oct 2023 17:57:03 -0400 Received: from mail-pj1-f50.google.com (mail-pj1-f50.google.com [209.85.216.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AE6310D8; Mon, 23 Oct 2023 14:57:01 -0700 (PDT) Received: by mail-pj1-f50.google.com with SMTP id 98e67ed59e1d1-27d45f5658fso3030010a91.3; Mon, 23 Oct 2023 14:57:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698098220; x=1698703020; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=H20lDRhK4GDyaMBBwpn1BdMOXepbGFTFy7qq+KEqdsE=; b=gy6EVAYX6Mx1yFWDVLX4QWY+v7lgzwue12T7u/pfRTA7ZOE6OG55jG7o0x2XE2pox/ t7XoDFQSGxGmBpoAnfRaudywxFS5prjKViptX2sQD2GkWQ699127yUc8UDyejJfZL/K8 jADuYZC3XXoYO4B1zZn/C9wBz8UVMnYRq6uYUUxEPQYupJ3CRtdW5ceRKldddNYwOHJs PUcNG4RoeqOuc2Hk9u1oWhAAtjHlKwSN6I0sp9tFd1GDEnZVaRu87dbLt+qBjAlvmFc3 +NUJSY5BCs43mas7/wkO7NpE5SQrPcJK209M++8ifeLiOdCpJb1qXsVkcDqoKqGwY5zK yYzQ== X-Gm-Message-State: AOJu0YyH3CgJjspj+cS7Gl/Iqc+YCaQCQuJsLenceke87uYQNXp8j9sE yM2L3kynftDwBFx0I85V9Pw= X-Google-Smtp-Source: AGHT+IFj8GUj8LPTAdQXglCzvPWwsAuByUWUeLoVRF/+ro182nUvxiD+SRguSfOtgymzVY6i0GsK9A== X-Received: by 2002:a17:90a:c087:b0:27e:277:3015 with SMTP id o7-20020a17090ac08700b0027e02773015mr10152039pjs.16.1698098220452; Mon, 23 Oct 2023 14:57:00 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:14f9:170e:9304:1c4e]) by smtp.gmail.com with ESMTPSA id b12-20020a17090acc0c00b0027d12b1e29dsm7851029pju.25.2023.10.23.14.56.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Oct 2023 14:57:00 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "Martin K . Petersen" , Christoph Hellwig , Bart Van Assche , Damien Le Moal , Ming Lei , "James E.J. Bottomley" Subject: [PATCH v14 06/19] scsi: core: Introduce a mechanism for reordering requests in the error handler Date: Mon, 23 Oct 2023 14:53:57 -0700 Message-ID: <20231023215638.3405959-7-bvanassche@acm.org> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog In-Reply-To: <20231023215638.3405959-1-bvanassche@acm.org> References: <20231023215638.3405959-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Introduce the .eh_needs_prepare_resubmit and the .eh_prepare_resubmit function pointers in struct scsi_driver. Make the error handler call .eh_prepare_resubmit() before resubmitting commands if any of the .eh_needs_prepare_resubmit() invocations return true. A later patch will use this functionality to sort SCSI commands by LBA from inside the SCSI disk driver before these are resubmitted by the error handler. Cc: Martin K. Petersen Cc: Damien Le Moal Cc: Christoph Hellwig Cc: Ming Lei Signed-off-by: Bart Van Assche Reviewed-by: Damien Le Moal --- drivers/scsi/scsi_error.c | 51 ++++++++++++++++++++++++++++++++++++++ drivers/scsi/scsi_priv.h | 2 ++ include/scsi/scsi_driver.h | 1 + include/scsi/scsi_host.h | 6 +++++ 4 files changed, 60 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 7390131e7f0a..a9588188e8a6 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -2186,6 +2187,54 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, } EXPORT_SYMBOL_GPL(scsi_eh_ready_devs); +/* + * Comparison function for sorting SCSI commands by ULD driver. + */ +static int scsi_cmp_uld(void *priv, const struct list_head *_a, + const struct list_head *_b) +{ + struct scsi_cmnd *a = list_entry(_a, typeof(*a), eh_entry); + struct scsi_cmnd *b = list_entry(_b, typeof(*b), eh_entry); + + /* See also the comment above the list_sort() definition. */ + return scsi_cmd_to_driver(a) > scsi_cmd_to_driver(b); +} + +void scsi_call_prepare_resubmit(struct Scsi_Host *shost, + struct list_head *done_q) +{ + struct scsi_cmnd *scmd, *next; + + if (!shost->hostt->needs_prepare_resubmit) + return; + + if (list_empty(done_q)) + return; + + /* Sort pending SCSI commands by ULD. */ + list_sort(NULL, done_q, scsi_cmp_uld); + + /* + * Call .eh_prepare_resubmit for each range of commands with identical + * ULD driver pointer. + */ + list_for_each_entry_safe(scmd, next, done_q, eh_entry) { + struct scsi_driver *uld = + scmd->device ? scsi_cmd_to_driver(scmd) : NULL; + struct list_head *prev, uld_cmd_list; + + while (&next->eh_entry != done_q && + scsi_cmd_to_driver(next) == uld) + next = list_next_entry(next, eh_entry); + if (!uld->eh_prepare_resubmit) + continue; + prev = scmd->eh_entry.prev; + list_cut_position(&uld_cmd_list, prev, next->eh_entry.prev); + uld->eh_prepare_resubmit(&uld_cmd_list); + list_splice(&uld_cmd_list, prev); + } +} + /** * scsi_eh_flush_done_q - finish processed commands or retry them. * @shost: SCSI host pointer. @@ -2195,6 +2244,8 @@ void scsi_eh_flush_done_q(struct Scsi_Host *shost, struct list_head *done_q) { struct scsi_cmnd *scmd, *next; + scsi_call_prepare_resubmit(shost, done_q); + list_for_each_entry_safe(scmd, next, done_q, eh_entry) { list_del_init(&scmd->eh_entry); if (scsi_device_online(scmd->device) && diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 3f0dfb97db6b..2caf4bcb072a 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -101,6 +101,8 @@ int scsi_eh_get_sense(struct list_head *work_q, struct list_head *done_q); bool scsi_noretry_cmd(struct scsi_cmnd *scmd); void scsi_eh_done(struct scsi_cmnd *scmd); +void scsi_call_prepare_resubmit(struct Scsi_Host *shost, + struct list_head *done_q); /* scsi_lib.c */ extern void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd); diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h index 4ce1988b2ba0..2b11be896eee 100644 --- a/include/scsi/scsi_driver.h +++ b/include/scsi/scsi_driver.h @@ -18,6 +18,7 @@ struct scsi_driver { int (*done)(struct scsi_cmnd *); int (*eh_action)(struct scsi_cmnd *, int); void (*eh_reset)(struct scsi_cmnd *); + void (*eh_prepare_resubmit)(struct list_head *cmd_list); }; #define to_scsi_driver(drv) \ container_of((drv), struct scsi_driver, gendrv) diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 49f768d0ff37..3e07e5b1a70c 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -461,6 +461,12 @@ struct scsi_host_template { /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ unsigned queuecommand_may_block:1; + /* + * The scsi_driver .eh_prepare_resubmit function must be called by + * the SCSI error handler. + */ + unsigned needs_prepare_resubmit:1; + /* * Countdown for host blocking with no commands outstanding. */