From patchwork Thu Dec 3 07:17:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 7756781 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AADF7BEEE1 for ; Thu, 3 Dec 2015 07:17:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7B0242054C for ; Thu, 3 Dec 2015 07:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B3FC20549 for ; Thu, 3 Dec 2015 07:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756283AbbLCHRt (ORCPT ); Thu, 3 Dec 2015 02:17:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:56194 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040AbbLCHRq (ORCPT ); Thu, 3 Dec 2015 02:17:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BA6A8ABA3; Thu, 3 Dec 2015 07:17:44 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: Christoph Hellwig , James Bottomley , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH 4/5] scsi: make asynchronous aborts mandatory Date: Thu, 3 Dec 2015 08:17:42 +0100 Message-Id: <1449127063-94512-5-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1449127063-94512-1-git-send-email-hare@suse.de> References: <1449127063-94512-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There hasn't been any reports for HBAs where asynchronous abort would not work, so we should make it mandatory and remove the fallback. Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn --- Documentation/scsi/scsi_eh.txt | 28 +++++++-------- drivers/scsi/scsi_error.c | 81 ++++-------------------------------------- drivers/scsi/scsi_lib.c | 2 +- drivers/scsi/scsi_priv.h | 3 +- include/scsi/scsi_host.h | 5 --- 5 files changed, 22 insertions(+), 97 deletions(-) diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt index 745eed5..6e07245fb 100644 --- a/Documentation/scsi/scsi_eh.txt +++ b/Documentation/scsi/scsi_eh.txt @@ -70,7 +70,7 @@ with the command. scmd is requeued to blk queue. - otherwise - scsi_eh_scmd_add(scmd, 0) is invoked for the command. See + scsi_eh_scmd_add(scmd) is invoked for the command. See [1-3] for details of this function. @@ -103,13 +103,15 @@ function eh_timed_out() callback did not handle the command. Step #2 is taken. - 2. If the host supports asynchronous completion (as indicated by the - no_async_abort setting in the host template) scsi_abort_command() - is invoked to schedule an asynchrous abort. If that fails - Step #3 is taken. + 2. scsi_abort_command() is invoked to schedule an asynchrous abort + (Seee [1-3] for more information). + Asynchronous abort are not invoked for commands which have + SCSI_EH_ABORT_SCHEDULED set (this indicates that the command + already had been aborted once, and this is a retry which failed), + or when the EH deadline is expired. In these case Step #3 is taken. - 2. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the - command. See [1-3] for more information. + 3. scsi_eh_scmd_add(scmd) is invoked for the + command. See [1-4] for more information. [1-3] Asynchronous command aborts @@ -124,16 +126,13 @@ function scmds enter EH via scsi_eh_scmd_add(), which does the following. - 1. Turns on scmd->eh_eflags as requested. It's 0 for error - completions and SCSI_EH_CANCEL_CMD for timeouts. + 1. Links scmd->eh_entry to shost->eh_cmd_q - 2. Links scmd->eh_entry to shost->eh_cmd_q + 2. Sets SHOST_RECOVERY bit in shost->shost_state - 3. Sets SHOST_RECOVERY bit in shost->shost_state + 3. Increments shost->host_failed - 4. Increments shost->host_failed - - 5. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed + 4. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed As can be seen above, once any scmd is added to shost->eh_cmd_q, SHOST_RECOVERY shost_state bit is turned on. This prevents any new @@ -249,7 +248,6 @@ scmd->allowed. 1. Error completion / time out ACTION: scsi_eh_scmd_add() is invoked for scmd - - set scmd->eh_eflags - add scmd to shost->eh_cmd_q - set SHOST_RECOVERY - shost->host_failed++ diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index eb0f19f..cf47b81 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -162,7 +162,7 @@ scmd_eh_abort_handler(struct work_struct *work) } } - scsi_eh_scmd_add(scmd, 0); + scsi_eh_scmd_add(scmd); } /** @@ -216,9 +216,8 @@ scsi_abort_command(struct scsi_cmnd *scmd) /** * scsi_eh_scmd_add - add scsi cmd to error handling. * @scmd: scmd to run eh on. - * @eh_flag: optional SCSI_EH flag. */ -void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag) +void scsi_eh_scmd_add(struct scsi_cmnd *scmd) { struct Scsi_Host *shost = scmd->device->host; unsigned long flags; @@ -236,9 +235,6 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag) if (shost->eh_deadline != -1 && !shost->last_reset) shost->last_reset = jiffies; - if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) - eh_flag &= ~SCSI_EH_CANCEL_CMD; - scmd->eh_eflags |= eh_flag; list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q); shost->host_failed++; scsi_eh_wakeup(shost); @@ -273,10 +269,9 @@ enum blk_eh_timer_return scsi_times_out(struct request *req) rtn = host->hostt->eh_timed_out(scmd); if (rtn == BLK_EH_NOT_HANDLED) { - if (host->hostt->no_async_abort || - scsi_abort_command(scmd) != SUCCESS) { + if (scsi_abort_command(scmd) != SUCCESS) { set_host_byte(scmd, DID_TIME_OUT); - scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD); + scsi_eh_scmd_add(scmd); } } @@ -329,7 +324,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost, list_for_each_entry(scmd, work_q, eh_entry) { if (scmd->device == sdev) { ++total_failures; - if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) + if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ++cmd_cancel; else ++cmd_failed; @@ -1152,8 +1147,7 @@ int scsi_eh_get_sense(struct list_head *work_q, * should not get sense. */ list_for_each_entry_safe(scmd, next, work_q, eh_entry) { - if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) || - (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) || + if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) || SCSI_SENSE_VALID(scmd)) continue; @@ -1293,61 +1287,6 @@ static int scsi_eh_test_devices(struct list_head *cmd_list, return list_empty(work_q); } - -/** - * scsi_eh_abort_cmds - abort pending commands. - * @work_q: &list_head for pending commands. - * @done_q: &list_head for processed commands. - * - * Decription: - * Try and see whether or not it makes sense to try and abort the - * running command. This only works out to be the case if we have one - * command that has timed out. If the command simply failed, it makes - * no sense to try and abort the command, since as far as the shost - * adapter is concerned, it isn't running. - */ -static int scsi_eh_abort_cmds(struct list_head *work_q, - struct list_head *done_q) -{ - struct scsi_cmnd *scmd, *next; - LIST_HEAD(check_list); - int rtn; - struct Scsi_Host *shost; - - list_for_each_entry_safe(scmd, next, work_q, eh_entry) { - if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD)) - continue; - shost = scmd->device->host; - if (scsi_host_eh_past_deadline(shost)) { - list_splice_init(&check_list, work_q); - SCSI_LOG_ERROR_RECOVERY(3, - scmd_printk(KERN_INFO, scmd, - "%s: skip aborting cmd, past eh deadline\n", - current->comm)); - return list_empty(work_q); - } - SCSI_LOG_ERROR_RECOVERY(3, - scmd_printk(KERN_INFO, scmd, - "%s: aborting cmd\n", current->comm)); - rtn = scsi_try_to_abort_cmd(shost->hostt, scmd); - if (rtn == FAILED) { - SCSI_LOG_ERROR_RECOVERY(3, - scmd_printk(KERN_INFO, scmd, - "%s: aborting cmd failed\n", - current->comm)); - list_splice_init(&check_list, work_q); - return list_empty(work_q); - } - scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD; - if (rtn == FAST_IO_FAIL) - scsi_eh_finish_cmd(scmd, done_q); - else - list_move_tail(&scmd->eh_entry, &check_list); - } - - return scsi_eh_test_devices(&check_list, work_q, done_q, 0); -} - /** * scsi_eh_try_stu - Send START_UNIT to device. * @scmd: &scsi_cmnd to send START_UNIT @@ -1690,11 +1629,6 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q, sdev_printk(KERN_INFO, scmd->device, "Device offlined - " "not ready after error recovery\n"); scsi_device_set_state(scmd->device, SDEV_OFFLINE); - if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) { - /* - * FIXME: Handle lost cmds. - */ - } scsi_eh_finish_cmd(scmd, done_q); } return; @@ -2138,8 +2072,7 @@ static void scsi_unjam_host(struct Scsi_Host *shost) SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q)); if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q)) - if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q)) - scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q); + scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q); spin_lock_irqsave(shost->host_lock, flags); if (shost->eh_deadline != -1) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 2dd7d0a..616e074 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1647,7 +1647,7 @@ static void scsi_softirq_done(struct request *rq) scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); break; default: - scsi_eh_scmd_add(cmd, 0); + scsi_eh_scmd_add(cmd); break; } } diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 8c26823..5534825 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -18,7 +18,6 @@ struct scsi_nl_hdr; /* * Scsi Error Handler Flags */ -#define SCSI_EH_CANCEL_CMD 0x0001 /* Cancel this cmd */ #define SCSI_EH_ABORT_SCHEDULED 0x0002 /* Abort has been scheduled */ #define SCSI_SENSE_VALID(scmd) \ @@ -71,7 +70,7 @@ extern enum blk_eh_timer_return scsi_times_out(struct request *req); extern int scsi_error_handler(void *host); extern int scsi_decide_disposition(struct scsi_cmnd *cmd); extern void scsi_eh_wakeup(struct Scsi_Host *shost); -extern void scsi_eh_scmd_add(struct scsi_cmnd *, int); +extern void scsi_eh_scmd_add(struct scsi_cmnd *); void scsi_eh_ready_devs(struct Scsi_Host *shost, struct list_head *work_q, struct list_head *done_q); diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index ed52712..ef7fff6 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -444,11 +444,6 @@ struct scsi_host_template { unsigned no_write_same:1; /* - * True if asynchronous aborts are not supported - */ - unsigned no_async_abort:1; - - /* * Countdown for host blocking with no commands outstanding. */ unsigned int max_host_blocked;