From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B19E8C433EF for ; Wed, 29 Sep 2021 22:06:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CEEC6124D for ; Wed, 29 Sep 2021 22:06:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347043AbhI2WIA (ORCPT ); Wed, 29 Sep 2021 18:08:00 -0400 Received: from mail-pg1-f172.google.com ([209.85.215.172]:40815 "EHLO mail-pg1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344298AbhI2WH7 (ORCPT ); Wed, 29 Sep 2021 18:07:59 -0400 Received: by mail-pg1-f172.google.com with SMTP id h3so4140269pgb.7 for ; Wed, 29 Sep 2021 15:06:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=TfTiZ3edd6c86PtaAT6AwyYW9o+FdCauqGDHiHet/BU=; b=uZ+9u5kPiS27Jgi2ahV8x9uzthu0Ek2x4XtCbq8XUSXqqPYPcplB/aeQ62Nz/3PGWk b0o4tijIVO01wGNPuQcysHQ8FJeqGrmCtqqkg6g1G3Ww6ci4aLFyjl1Gd6NOY5vSxCsH RggYKDOyr3VlV0w5S5cSokyYMQTmKcH9gmZZQ6Q54hmoVXx8ovlcMXTCLpLAdJpsyDP7 iEVAUJ3RlTOag/TM9uZ8P2orRoWnmANkWLoHbGQ70YPONKrvAh24XOpXDfIk7T2isVno t15W8dMX8TBkRiwBKs9Z5puKo3n2znLl7EhaqXpwaiVlTihxP0UK/rS77pIJEkf0GEgo ByuQ== X-Gm-Message-State: AOAM530PWRk6rB+F2iJlHRQ0DXRWxtFI1vcXNILW2l+3X9wiZnkCJyE0 qV4RSFjiV/v5hx4d4U3xNnY= X-Google-Smtp-Source: ABdhPJwI1L/WDxeouJ2no0xlfgS5Zov4LcwZYAkQMQ3qL8wHe4beXOlTLaZ4edqLlalCLkSDLWclqQ== X-Received: by 2002:a05:6a00:1390:b0:447:961d:39b9 with SMTP id t16-20020a056a00139000b00447961d39b9mr2002307pfg.83.1632953178067; Wed, 29 Sep 2021 15:06:18 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:5c11:c4f:db56:119]) by smtp.gmail.com with ESMTPSA id gk14sm2785585pjb.35.2021.09.29.15.06.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Sep 2021 15:06:17 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Bart Van Assche , Hannes Reinecke , Ming Lei , Christoph Hellwig , "James E.J. Bottomley" Subject: [PATCH v2 01/84] scsi: core: Use a member variable to track the SCSI command submitter Date: Wed, 29 Sep 2021 15:04:37 -0700 Message-Id: <20210929220600.3509089-2-bvanassche@acm.org> X-Mailer: git-send-email 2.33.0.685.g46640cef36-goog In-Reply-To: <20210929220600.3509089-1-bvanassche@acm.org> References: <20210929220600.3509089-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Conditional statements are faster than indirect calls. Use a member variable to track the SCSI command submitter such that later patches can call scsi_done(scmd) instead of scmd->scsi_done(scmd). The asymmetric behavior that scsi_send_eh_cmnd() sets the submission context to the SCSI error handler and that it does not restore the submission context to the SCSI core is retained. Cc: Hannes Reinecke Cc: Ming Lei Cc: Christoph Hellwig Signed-off-by: Bart Van Assche --- drivers/scsi/scsi_error.c | 18 +++++++----------- drivers/scsi/scsi_lib.c | 10 ++++++++++ drivers/scsi/scsi_priv.h | 1 + include/scsi/scsi_cmnd.h | 7 +++++++ 4 files changed, 25 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index b6c86cce57bf..26f1388decef 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -50,8 +50,6 @@ #include -static void scsi_eh_done(struct scsi_cmnd *scmd); - /* * These should *probably* be handled by the host itself. * Since it is allowed to sleep, it probably should. @@ -520,7 +518,8 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd) /* handler does not care. Drop down to default handling */ } - if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done) + if (scmd->cmnd[0] == TEST_UNIT_READY && + scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER) /* * nasty: for mid-layer issued TURs, we need to return the * actual sense data without any recovery attempt. For eh @@ -782,7 +781,7 @@ static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd) * scsi_eh_done - Completion function for error handling. * @scmd: Cmd that is done. */ -static void scsi_eh_done(struct scsi_cmnd *scmd) +void scsi_eh_done(struct scsi_cmnd *scmd) { struct completion *eh_action; @@ -986,6 +985,7 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses, ses->prot_op = scmd->prot_op; ses->eh_eflags = scmd->eh_eflags; + WARN_ON_ONCE(scmd->submitter != SUBMITTED_BY_BLOCK_LAYER); scmd->prot_op = SCSI_PROT_NORMAL; scmd->eh_eflags = 0; scmd->cmnd = ses->eh_cmnd; @@ -1082,7 +1082,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd, shost->eh_action = &done; scsi_log_send(scmd); - scmd->scsi_done = scsi_eh_done; + scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER; /* * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can @@ -1109,6 +1109,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd, if (rtn) { if (timeleft > stall_for) { scsi_eh_restore_cmnd(scmd, &ses); + timeleft -= stall_for; msleep(jiffies_to_msecs(stall_for)); goto retry; @@ -2338,11 +2339,6 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) } EXPORT_SYMBOL(scsi_report_device_reset); -static void -scsi_reset_provider_done_command(struct scsi_cmnd *scmd) -{ -} - /** * scsi_ioctl_reset: explicitly reset a host/bus/target/device * @dev: scsi_device to operate on @@ -2379,7 +2375,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) scsi_init_command(dev, scmd); scmd->cmnd = scsi_req(rq)->cmd; - scmd->scsi_done = scsi_reset_provider_done_command; + scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL; memset(&scmd->sdb, 0, sizeof(scmd->sdb)); scmd->cmd_len = 0; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index dcf105287a76..c0c1f1ca0382 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1577,6 +1577,15 @@ static blk_status_t scsi_prepare_cmd(struct request *req) static void scsi_mq_done(struct scsi_cmnd *cmd) { + switch (cmd->submitter) { + case SUBMITTED_BY_BLOCK_LAYER: + break; + case SUBMITTED_BY_SCSI_ERROR_HANDLER: + return scsi_eh_done(cmd); + case SUBMITTED_BY_SCSI_RESET_IOCTL: + return; + } + if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) return; if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) @@ -1683,6 +1692,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, scsi_set_resid(cmd, 0); memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); + cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; cmd->scsi_done = scsi_mq_done; blk_mq_start_request(req); diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 6d9152031a40..b7f963149352 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -84,6 +84,7 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, int scsi_eh_get_sense(struct list_head *work_q, struct list_head *done_q); int scsi_noretry_cmd(struct scsi_cmnd *scmd); +void scsi_eh_done(struct scsi_cmnd *scmd); /* scsi_lib.c */ extern int scsi_maybe_unblock_host(struct scsi_device *sdev); diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index a2315aac93c7..893c24aab8e4 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -64,6 +64,12 @@ struct scsi_pointer { #define SCMD_STATE_COMPLETE 0 #define SCMD_STATE_INFLIGHT 1 +enum scsi_cmnd_submitter { + SUBMITTED_BY_BLOCK_LAYER = 0, + SUBMITTED_BY_SCSI_ERROR_HANDLER = 1, + SUBMITTED_BY_SCSI_RESET_IOCTL = 2, +} __packed; + struct scsi_cmnd { struct scsi_request req; struct scsi_device *device; @@ -89,6 +95,7 @@ struct scsi_cmnd { unsigned char prot_op; unsigned char prot_type; unsigned char prot_flags; + enum scsi_cmnd_submitter submitter; unsigned short cmd_len; enum dma_data_direction sc_data_direction;