From patchwork Tue Aug 22 19:16:59 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: 716403 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 31B0EEE49B5 for ; Tue, 22 Aug 2023 19:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230075AbjHVTSv (ORCPT ); Tue, 22 Aug 2023 15:18:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229958AbjHVTSv (ORCPT ); Tue, 22 Aug 2023 15:18:51 -0400 Received: from mail-pj1-f42.google.com (mail-pj1-f42.google.com [209.85.216.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7276BCED; Tue, 22 Aug 2023 12:18:49 -0700 (PDT) Received: by mail-pj1-f42.google.com with SMTP id 98e67ed59e1d1-26f9521de4cso639294a91.0; Tue, 22 Aug 2023 12:18:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692731929; x=1693336729; 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=CZv/GCTChROxyk79tHpawLiGp2hTN5F6+jFSRDwuk9c=; b=Hdbmy7M6J3g0MYWoBrBs+lHLkWuWxOs2Nk8jFzZ1HciElm8ad3qfuRLXh5VTxGxNxD XGVObclcknZ/g6yeuaEhLkunCwg721EX/7kmcR0eweP971dmLCElcE3F8Wk2nU61DTCe awhRs3+r8fSIEebqvgTxTMVzTd4PNA3K52J72KUg0rDnnbCBqFzT0HLIheFfMaPhyIN4 CAacVGUE0buVk0/7eSexMH/hpW7COVJpu1i9FVnlRZwC2XESu/s1VNA7oo9hkh0gx8Be OI+iNrUTmGNI8bIFh/6BITFJvqa1VouDdR4ghmaXZYnUFLap5ofGHN/fSFYfR3QFkeQU Mk3Q== X-Gm-Message-State: AOJu0YxyN09aeVyG9TfUL0ryIv3fYx4/ygFz/c2BBPgLsYFrGtIumENB xyJqKfFMaYmTk42DFXaz4SY= X-Google-Smtp-Source: AGHT+IHBfms/6a3mxq/qYBN4wm+paRd10JqgMtg49IbgeoVs01JLgywZDFrr4/V31wQf5qrS2ONH7A== X-Received: by 2002:a17:90a:674e:b0:268:dd0:3497 with SMTP id c14-20020a17090a674e00b002680dd03497mr7467774pjm.7.1692731928843; Tue, 22 Aug 2023 12:18:48 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:88be:bf57:de29:7cc]) by smtp.gmail.com with ESMTPSA id m11-20020a17090a414b00b002696bd123e4sm8081632pjg.46.2023.08.22.12.18.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Aug 2023 12:18:48 -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 v11 04/16] scsi: core: Introduce a mechanism for reordering requests in the error handler Date: Tue, 22 Aug 2023 12:16:59 -0700 Message-ID: <20230822191822.337080-5-bvanassche@acm.org> X-Mailer: git-send-email 2.42.0.rc1.204.g551eb34607-goog In-Reply-To: <20230822191822.337080-1-bvanassche@acm.org> References: <20230822191822.337080-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@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 --- drivers/scsi/scsi_error.c | 65 ++++++++++++++++++++++++++++++++++++++ drivers/scsi/scsi_priv.h | 1 + include/scsi/scsi_driver.h | 2 ++ 3 files changed, 68 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index c67cdcdc3ba8..c4d817f044a0 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 +2187,68 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, } EXPORT_SYMBOL_GPL(scsi_eh_ready_devs); +/* + * Returns true if .eh_prepare_resubmit should be called for the commands in + * @done_q. + */ +static bool scsi_needs_preparation(struct list_head *done_q) +{ + struct scsi_cmnd *scmd; + + list_for_each_entry(scmd, done_q, eh_entry) { + struct scsi_driver *uld = scsi_cmd_to_driver(scmd); + bool (*npr)(struct scsi_cmnd *) = uld->eh_needs_prepare_resubmit; + + if (npr && npr(scmd)) + return true; + } + + return false; +} + +/* + * Comparison function that allows to sort 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 list_head *done_q) +{ + struct scsi_cmnd *scmd, *next; + + if (!scsi_needs_preparation(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 = scsi_cmd_to_driver(scmd); + 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. * @done_q: list_head of processed commands. @@ -2194,6 +2257,8 @@ void scsi_eh_flush_done_q(struct list_head *done_q) { struct scsi_cmnd *scmd, *next; + scsi_call_prepare_resubmit(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 f42388ecb024..df4af4645430 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -101,6 +101,7 @@ 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 list_head *done_q); /* scsi_lib.c */ extern int scsi_maybe_unblock_host(struct scsi_device *sdev); diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h index 4ce1988b2ba0..00ffa470724a 100644 --- a/include/scsi/scsi_driver.h +++ b/include/scsi/scsi_driver.h @@ -18,6 +18,8 @@ struct scsi_driver { int (*done)(struct scsi_cmnd *); int (*eh_action)(struct scsi_cmnd *, int); void (*eh_reset)(struct scsi_cmnd *); + bool (*eh_needs_prepare_resubmit)(struct scsi_cmnd *cmd); + void (*eh_prepare_resubmit)(struct list_head *cmd_list); }; #define to_scsi_driver(drv) \ container_of((drv), struct scsi_driver, gendrv)