From patchwork Fri Sep 1 09:41:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wenchao Hao X-Patchwork-Id: 13372341 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 254C2CA0FE8 for ; Fri, 1 Sep 2023 09:42:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349019AbjIAJmp (ORCPT ); Fri, 1 Sep 2023 05:42:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348922AbjIAJmW (ORCPT ); Fri, 1 Sep 2023 05:42:22 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 583561732; Fri, 1 Sep 2023 02:42:01 -0700 (PDT) Received: from kwepemm600012.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RcY013mYyzVkSC; Fri, 1 Sep 2023 17:39:29 +0800 (CST) Received: from build.huawei.com (10.175.101.6) by kwepemm600012.china.huawei.com (7.193.23.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Fri, 1 Sep 2023 17:41:57 +0800 From: Wenchao Hao To: "James E . J . Bottomley" , "Martin K . Petersen" , CC: Hannes Reinecke , , , , Wenchao Hao Subject: [RFC PATCH v2 11/19] scsi: scsi_error: Add a general target based error handler Date: Fri, 1 Sep 2023 17:41:19 +0800 Message-ID: <20230901094127.2010873-12-haowenchao2@huawei.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20230901094127.2010873-1-haowenchao2@huawei.com> References: <20230901094127.2010873-1-haowenchao2@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600012.china.huawei.com (7.193.23.74) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Add a general target based error handler which can be used by drivers directly. This error handler implements an scsi_target_eh, when handling error commands, it would call helper function scsi_starget_eh() added before to try recover error commands. The behavior if scsi_starget_eh() can not recover all error commands depends on fallback flag, which is initialized when scsi_target is allocated. If fallback is set, it would fallback to further error recover strategy like old host based error handle; else it would mark this scsi devices of this target offline and flush all error commands. To using this error handler, drivers should call scsi_target_setup_eh() in its target_alloc() to setup it's target based error handler; call scsi_device_clear_eh() in its target_destroy() to clear this target based error handler. Signed-off-by: Wenchao Hao --- drivers/scsi/scsi_error.c | 161 ++++++++++++++++++++++++++++++++++++++ include/scsi/scsi_eh.h | 2 + 2 files changed, 163 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 50cd8104175d..1338742e55b9 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -101,6 +101,19 @@ static inline void shost_clear_eh_done(struct Scsi_Host *shost) } } +static inline void starget_clear_eh_done(struct scsi_target *starget) +{ + struct scsi_device *sdev; + + list_for_each_entry(sdev, &starget->devices, same_target_siblings) { + if (!sdev->eh) + continue; + sdev->eh->get_sense_done = 0; + sdev->eh->stu_done = 0; + sdev->eh->reset_done = 0; + } +} + void scsi_eh_wakeup(struct Scsi_Host *shost) { lockdep_assert_held(shost->host_lock); @@ -3058,3 +3071,151 @@ void scsi_device_clear_eh(struct scsi_device *sdev) sdev->eh = NULL; } EXPORT_SYMBOL_GPL(scsi_device_clear_eh); + +struct starget_eh { + spinlock_t eh_lock; + unsigned int eh_num; + struct list_head eh_cmd_q; + struct scsi_target *starget; + struct work_struct eh_handle_work; + unsigned int fallback:1; +}; + +static void starget_eh_work(struct work_struct *work) +{ + struct scsi_cmnd *scmd, *next; + unsigned long flags; + LIST_HEAD(eh_work_q); + LIST_HEAD(eh_done_q); + struct starget_eh *stargeteh = + container_of(work, struct starget_eh, eh_handle_work); + struct scsi_target *starget = stargeteh->starget; + struct scsi_target_eh *eh = starget->eh; + + spin_lock_irqsave(&stargeteh->eh_lock, flags); + list_splice_init(&stargeteh->eh_cmd_q, &eh_work_q); + spin_unlock_irqrestore(&stargeteh->eh_lock, flags); + + if (scsi_starget_eh(starget, &eh_work_q, &eh_done_q)) + goto out_clear_flag; + + if (!stargeteh->fallback) { + scsi_eh_offline_sdevs(&eh_work_q, &eh_done_q); + goto out_clear_flag; + } + + /* + * fallback to host based error handle + */ + SCSI_LOG_ERROR_RECOVERY(2, starget_printk(KERN_INFO, starget, + "%s:targeteh fallback to further recovery\n", current->comm)); + eh->reset_done = 1; + list_for_each_entry_safe(scmd, next, &eh_work_q, eh_entry) { + list_del_init(&scmd->eh_entry); + __scsi_eh_scmd_add(scmd); + } + goto out_flush_done; + +out_clear_flag: + starget_clear_eh_done(starget); + +out_flush_done: + scsi_eh_flush_done_q(&eh_done_q); + spin_lock_irqsave(&stargeteh->eh_lock, flags); + stargeteh->eh_num = 0; + spin_unlock_irqrestore(&stargeteh->eh_lock, flags); +} + +static void starget_eh_add_cmnd(struct scsi_cmnd *scmd) +{ + unsigned long flags; + struct scsi_target *starget = scmd->device->sdev_target; + struct starget_eh *eh; + + eh = (struct starget_eh *)starget->eh->driver_data; + + spin_lock_irqsave(&eh->eh_lock, flags); + list_add_tail(&scmd->eh_entry, &eh->eh_cmd_q); + eh->eh_num++; + spin_unlock_irqrestore(&eh->eh_lock, flags); +} + +static int starget_eh_is_busy(struct scsi_target *starget) +{ + int ret = 0; + unsigned long flags; + struct starget_eh *eh; + + eh = (struct starget_eh *)starget->eh->driver_data; + + spin_lock_irqsave(&eh->eh_lock, flags); + ret = eh->eh_num; + spin_unlock_irqrestore(&eh->eh_lock, flags); + + return ret; +} + +static int starget_eh_wakeup(struct scsi_target *starget) +{ + unsigned long flags; + unsigned int nr_error; + unsigned int nr_busy; + struct starget_eh *eh; + + eh = (struct starget_eh *)starget->eh->driver_data; + + spin_lock_irqsave(&eh->eh_lock, flags); + nr_error = eh->eh_num; + spin_unlock_irqrestore(&eh->eh_lock, flags); + + nr_busy = atomic_read(&starget->target_busy); + + if (!nr_error || nr_busy != nr_error) { + SCSI_LOG_ERROR_RECOVERY(5, starget_printk(KERN_INFO, starget, + "%s:targeteh: do not wake up, busy/error is %d/%d\n", + current->comm, nr_busy, nr_error)); + return 0; + } + + SCSI_LOG_ERROR_RECOVERY(2, starget_printk(KERN_INFO, starget, + "%s:targeteh: waking up, busy/error is %d/%d\n", + current->comm, nr_busy, nr_error)); + + return schedule_work(&eh->eh_handle_work); +} + +int scsi_target_setup_eh(struct scsi_target *starget, int fallback) +{ + struct scsi_target_eh *eh; + struct starget_eh *stargeteh; + + eh = kzalloc(sizeof(struct scsi_device_eh) + sizeof(struct starget_eh), + GFP_KERNEL); + if (!eh) { + starget_printk(KERN_ERR, starget, "failed to setup eh\n"); + return -ENOMEM; + } + stargeteh = (struct starget_eh *)eh->driver_data; + + eh->add_cmnd = starget_eh_add_cmnd; + eh->is_busy = starget_eh_is_busy; + eh->wakeup = starget_eh_wakeup; + stargeteh->starget = starget; + stargeteh->fallback = fallback; + + spin_lock_init(&stargeteh->eh_lock); + INIT_LIST_HEAD(&stargeteh->eh_cmd_q); + INIT_WORK(&stargeteh->eh_handle_work, starget_eh_work); + + starget->eh = eh; + + return 0; +} +EXPORT_SYMBOL_GPL(scsi_target_setup_eh); + +void scsi_target_clear_eh(struct scsi_target *starget) +{ + kfree(starget->eh); + starget->eh = NULL; +} +EXPORT_SYMBOL_GPL(scsi_target_clear_eh); diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h index 80e2f130e884..011f63030589 100644 --- a/include/scsi/scsi_eh.h +++ b/include/scsi/scsi_eh.h @@ -24,6 +24,8 @@ extern int scsi_starget_eh(struct scsi_target *starget, struct list_head *workq, struct list_head *doneq); extern int scsi_device_setup_eh(struct scsi_device *sdev, int fallback); extern void scsi_device_clear_eh(struct scsi_device *sdev); +extern int scsi_target_setup_eh(struct scsi_target *starget, int fallback); +extern void scsi_target_clear_eh(struct scsi_target *starget); static inline bool scsi_sense_is_deferred(const struct scsi_sense_hdr *sshdr) {