diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ad1476fb5035..e047747d4ecf 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -231,6 +231,12 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, goto fail; } + if (shost->nr_reserved_cmds && !sht->queue_reserved_command) { + shost_printk(KERN_ERR, shost, + "nr_reserved_cmds set but no method to queue\n"); + goto fail; + } + /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */ shost->cmd_per_lun = min_t(int, shost->cmd_per_lun, shost->can_queue); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 53ff348b3a4c..d4e874bbf2ea 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1534,6 +1534,14 @@ static void scsi_complete(struct request *rq) struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); enum scsi_disposition disposition; + if (blk_mq_is_reserved_rq(rq)) { + /* Only pass-through requests are supported in this code path. */ + WARN_ON_ONCE(!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))); + scsi_mq_uninit_cmd(cmd); + __blk_mq_end_request(rq, scsi_result_to_blk_status(cmd->result)); + return; + } + INIT_LIST_HEAD(&cmd->eh_entry); atomic_inc(&cmd->device->iodone_cnt); @@ -1823,25 +1831,31 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, WARN_ON_ONCE(cmd->budget_token < 0); /* - * If the device is not in running state we will reject some or all - * commands. + * Bypass the SCSI device, SCSI target and SCSI host checks for + * reserved commands. */ - if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { - ret = scsi_device_state_check(sdev, req); - if (ret != BLK_STS_OK) - goto out_put_budget; - } + if (!blk_mq_is_reserved_rq(req)) { + /* + * If the device is not in running state we will reject some or + * all commands. + */ + if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { + ret = scsi_device_state_check(sdev, req); + if (ret != BLK_STS_OK) + goto out_put_budget; + } - ret = BLK_STS_RESOURCE; - if (!scsi_target_queue_ready(shost, sdev)) - goto out_put_budget; - if (unlikely(scsi_host_in_recovery(shost))) { - if (cmd->flags & SCMD_FAIL_IF_RECOVERING) - ret = BLK_STS_OFFLINE; - goto out_dec_target_busy; + ret = BLK_STS_RESOURCE; + if (!scsi_target_queue_ready(shost, sdev)) + goto out_put_budget; + if (unlikely(scsi_host_in_recovery(shost))) { + if (cmd->flags & SCMD_FAIL_IF_RECOVERING) + ret = BLK_STS_OFFLINE; + goto out_dec_target_busy; + } + if (!scsi_host_queue_ready(q, shost, sdev, cmd)) + goto out_dec_target_busy; } - if (!scsi_host_queue_ready(q, shost, sdev, cmd)) - goto out_dec_target_busy; /* * Only clear the driver-private command data if the LLD does not supply @@ -1870,6 +1884,14 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; blk_mq_start_request(req); + if (blk_mq_is_reserved_rq(req)) { + reason = shost->hostt->queue_reserved_command(shost, cmd); + if (reason) { + ret = BLK_STS_RESOURCE; + goto out_put_budget; + } + return BLK_STS_OK; + } reason = scsi_dispatch_cmd(cmd); if (reason) { scsi_set_blocked(cmd, reason); diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 4f945a20d198..e87cf7eadd26 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -86,6 +86,12 @@ struct scsi_host_template { */ int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *); + /* + * Queue a reserved command (BLK_MQ_REQ_RESERVED). The .queuecommand() + * documentation also applies to the .queue_reserved_command() callback. + */ + int (*queue_reserved_command)(struct Scsi_Host *, struct scsi_cmnd *); + /* * The commit_rqs function is used to trigger a hardware * doorbell after some requests have been queued with