diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 46947ed0c657..c154103d892c 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -658,29 +658,12 @@ int ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap, set_host_byte(scmd, DID_OK); ata_qc_for_each_raw(ap, qc, i) { - if (qc->scsicmd != scmd) - continue; - if ((qc->flags & ATA_QCFLAG_ACTIVE) || - qc == qc->dev->link->deferred_qc) + if (qc->scsicmd == scmd && + qc->flags & ATA_QCFLAG_ACTIVE) break; } - if (i < ATA_MAX_QUEUE && qc == qc->dev->link->deferred_qc) { - /* - * This is a deferred command that timed out while - * waiting for the command queue to drain. Since the qc - * is not active yet (deferred_qc is still set, so the - * deferred qc work has not issued the command yet), - * simply signal the timeout by finishing the SCSI - * command and clear the deferred qc to prevent the - * deferred qc work from issuing this qc. - */ - WARN_ON_ONCE(qc->flags & ATA_QCFLAG_ACTIVE); - qc->dev->link->deferred_qc = NULL; - cancel_work(&qc->dev->link->deferred_qc_work); - set_host_byte(scmd, DID_TIME_OUT); - scsi_eh_finish_cmd(scmd, &ap->eh_done_q); - } else if (i < ATA_MAX_QUEUE) { + if (i < ATA_MAX_QUEUE) { /* the scmd has an associated qc */ if (!(qc->flags & ATA_QCFLAG_EH)) { /* which hasn't failed yet, timeout */ @@ -956,10 +939,10 @@ static void ata_eh_set_pending(struct ata_port *ap, bool fastdrain) ap->pflags |= ATA_PFLAG_EH_PENDING; /* - * If we have a deferred qc, requeue it so that it is retried once EH - * completes. + * If we have deferred QCs, requeue them so that the SCSI EH task can + * run. */ - ata_scsi_requeue_deferred_qc(ap); + ata_scsi_requeue_deferred_qc(ap, NULL); if (!fastdrain) return; diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 5868526301a2..02b04de925f9 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -1685,26 +1685,80 @@ void ata_scsi_deferred_qc_work(struct work_struct *work) spin_unlock_irqrestore(ap->lock, flags); } -void ata_scsi_requeue_deferred_qc(struct ata_port *ap) +enum scsi_timeout_action ata_scsi_requeue_deferred_qc(struct ata_port *ap, + struct scsi_cmnd *timedout_scmd) { + enum scsi_timeout_action action = SCSI_EH_NOT_HANDLED; + struct ata_queued_cmd *qc; struct ata_link *link; + u32 host_byte; lockdep_assert_held(ap->lock); /* - * If we have a deferred qc when a reset occurs or NCQ commands fail, - * do not try to be smart about what to do with this deferred command - * and simply requeue it by completing it with DID_REQUEUE. + * If we have deferred QCs when a reset, a timeout or an NCQ command + * fails, do not try to be smart about what to do with the deferred + * commands and simply terminate them and let the SCSI layer decide + * what to do. */ ata_for_each_link(link, ap, PMP_FIRST) { - struct ata_queued_cmd *qc = link->deferred_qc; + qc = link->deferred_qc; + if (!qc) + continue; - if (qc) { - link->deferred_qc = NULL; - cancel_work(&link->deferred_qc_work); - ata_scsi_qc_done(qc, true, DID_REQUEUE << 16); + /* + * Clear the deferred QC so that the deferred work does not try + * to issue it. + */ + link->deferred_qc = NULL; + cancel_work(&link->deferred_qc_work); + + /* + * We are going to complete some scsi command, either with + * DID_TIME_OUT if the command timed out while waiting for being + * issued, or with DID_REQUEUE if another command timed out or + * we had a failed command. However, the block layer may re-issue + * these commands immediately, keeping the scsi host busy and + * thus preventing the SCSI EH task from running. + * So schedule EH on the port to prevent accepting new commands + * until everything is sorted out with the error or timeout that + * got us here in the first place. Note that we set EH pending + * on the port before calling ata_port_schedule_eh() so that we + * do not reenter this function from ata_eh_set_pending() with + * timedout_scmd being NULL and erroneously retry deferred QCs + * that have timed out on other links. + */ + if (!ata_port_eh_scheduled(ap)) { + ap->pflags |= ATA_PFLAG_EH_PENDING; + ata_port_schedule_eh(ap); } + + /* + * If we are being called from scsi_timeout(), then we have a + * non-NULL timedout_scmd. If the timed out command is for a + * deferred QC, terminate that deferred QC with DID_TIME_OUT and + * requeue all other deferred QCs. In this case we need to + * return SCSI_EH_DONE, because the timed out command was + * handled. + * If the timed out command is not for a deferred QC, we need to + * requeue all deferred QCs, and return SCSI_EH_NOT_HANDLED so + * that the timed out command gets added to the EH work queue + * with scsi_eh_scmd_add(), for later handling with libata EH + * ata_scsi_cmd_error_handler(). + * If timedout_scmd is NULL, we simply need to requeue all + * deferred QCs and the return value does not matter as we were + * not called from scsi_timeout(). + */ + if (timedout_scmd && qc->scsicmd == timedout_scmd) { + host_byte = DID_TIME_OUT; + action = SCSI_EH_DONE; + } else { + host_byte = DID_REQUEUE; + } + ata_scsi_qc_done(qc, true, host_byte << 16); } + + return action; } static void ata_scsi_schedule_deferred_qc(struct ata_link *link) @@ -1723,13 +1777,41 @@ static void ata_scsi_schedule_deferred_qc(struct ata_link *link) return; if (ata_port_eh_scheduled(ap)) { - ata_scsi_requeue_deferred_qc(ap); + ata_scsi_requeue_deferred_qc(ap, NULL); return; } if (!ap->ops->qc_defer(qc)) queue_work(system_highpri_wq, &link->deferred_qc_work); } +static enum scsi_timeout_action +ata_scsi_retry_deferred_qc(struct ata_port *ap, struct scsi_cmnd *scmd) +{ + enum scsi_timeout_action action; + unsigned long flags; + + spin_lock_irqsave(ap->lock, flags); + action = ata_scsi_requeue_deferred_qc(ap, scmd); + spin_unlock_irqrestore(ap->lock, flags); + + return action; +} + +enum scsi_timeout_action ata_scsi_eh_timed_out(struct scsi_cmnd *scmd) +{ + struct ata_port *ap = ata_shost_to_port(scmd->device->host); + + /* + * ata_scsi_cmd_error_handler() takes care of commands that timed out + * while executing. However, if we have deferred QCs while a timeout + * triggers, we must requeue these commands for retry so that we do not + * unnecessarily delay starting the SCSI EH task until these deferred + * commands also time out. + */ + return ata_scsi_retry_deferred_qc(ap, scmd); +} +EXPORT_SYMBOL_GPL(ata_scsi_eh_timed_out); + static void ata_scsi_qc_complete(struct ata_queued_cmd *qc) { struct ata_link *link = qc->dev->link; @@ -2936,7 +3018,15 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc) if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev) qc->dev->sdev->locked = 0; - ata_scsi_qc_done(qc, true, SAM_STAT_CHECK_CONDITION); + if (cmd->result) + ata_scsi_qc_done(qc, false, 0); + else + ata_scsi_qc_done(qc, true, SAM_STAT_CHECK_CONDITION); + return; + } + + if (cmd->result) { + ata_scsi_qc_done(qc, false, 0); return; } diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h index 700627596ce1..8dacc1daabf0 100644 --- a/drivers/ata/libata.h +++ b/drivers/ata/libata.h @@ -180,7 +180,8 @@ enum scsi_qc_status __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_port *ap) __must_hold(ap->lock); void ata_scsi_deferred_qc_work(struct work_struct *work); -void ata_scsi_requeue_deferred_qc(struct ata_port *ap); +enum scsi_timeout_action ata_scsi_requeue_deferred_qc(struct ata_port *ap, + struct scsi_cmnd *scmd); /* libata-eh.c */ extern unsigned int ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd); diff --git a/include/linux/libata.h b/include/linux/libata.h index 6c0d385b2cde..f10b3287b507 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1153,6 +1153,7 @@ extern int ata_scsi_ioctl(struct scsi_device *dev, unsigned int cmd, #endif extern enum scsi_qc_status ata_scsi_queuecmd(struct Scsi_Host *h, struct scsi_cmnd *cmd); +enum scsi_timeout_action ata_scsi_eh_timed_out(struct scsi_cmnd *cmd); #if IS_REACHABLE(CONFIG_ATA) bool ata_scsi_dma_need_drain(struct request *rq); #else @@ -1464,6 +1465,7 @@ extern const struct attribute_group *ata_common_sdev_groups[]; .ioctl = ata_scsi_ioctl, \ ATA_SCSI_COMPAT_IOCTL \ .queuecommand = ata_scsi_queuecmd, \ + .eh_timed_out = ata_scsi_eh_timed_out, \ .dma_need_drain = ata_scsi_dma_need_drain, \ .this_id = ATA_SHT_THIS_ID, \ .emulated = ATA_SHT_EMULATED, \