From 2171b6d08bf8c2b826922b94e24ba36b00cb78b3 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Thu, 6 Apr 2017 15:36:34 +0200 Subject: scsi: make scsi_eh_scmd_add() always succeed scsi_eh_scmd_add() currently only will fail if no error handler thread is started (which will never be the case) or if the state machine encounters an illegal transition. But if we're encountering an invalid state transition chances is we cannot fixup things with the error handler. So better add a WARN_ON for illegal host states and make scsi_dh_scmd_add() a void function. Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_priv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/scsi/scsi_priv.h') diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 99bfc985e190..5be6cbf69df6 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -72,7 +72,7 @@ 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 int scsi_eh_scmd_add(struct scsi_cmnd *, int); +extern void scsi_eh_scmd_add(struct scsi_cmnd *, int); void scsi_eh_ready_devs(struct Scsi_Host *shost, struct list_head *work_q, struct list_head *done_q); -- cgit v1.2.3 From a06586325f371c0f0f6095454b5beca0602eaab4 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Thu, 6 Apr 2017 15:36:35 +0200 Subject: scsi: make asynchronous aborts mandatory 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 Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- Documentation/scsi/scsi_eh.txt | 18 ++++------ 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, 15 insertions(+), 94 deletions(-) (limited to 'drivers/scsi/scsi_priv.h') diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt index 4edb9c1cbef5..11e447bdb3a5 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. @@ -103,9 +103,7 @@ 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. + 2. scsi_abort_command() is invoked to schedule an asynchrous abort. Asynchronous abort are not invoked for commands which the SCSI_EH_ABORT_SCHEDULED flag is set (this indicates that the command already had been aborted once, and this is a retry which failed), @@ -127,16 +125,13 @@ 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 @@ -252,7 +247,6 @@ 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 bbc431897606..53e334356f31 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); } /** @@ -221,9 +221,8 @@ static void scsi_eh_reset(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; @@ -239,9 +238,6 @@ 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; scsi_eh_reset(scmd); list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q); shost->host_failed++; @@ -275,10 +271,9 @@ 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); } } @@ -331,7 +326,7 @@ 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; @@ -1154,8 +1149,7 @@ 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; @@ -1295,61 +1289,6 @@ 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 @@ -1692,11 +1631,6 @@ 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; @@ -2140,8 +2074,7 @@ 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 ba8da904e774..9822fdeed0ce 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1593,7 +1593,7 @@ 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 5be6cbf69df6..e20ab10623fb 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) \ @@ -72,7 +71,7 @@ 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 3cd8c3bec638..afb04811b7b9 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -451,11 +451,6 @@ struct scsi_host_template { /* True if the controller does not support WRITE SAME */ 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. */ -- cgit v1.2.3