From f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 1 Nov 2018 16:36:27 -0600 Subject: scsi: kill off the legacy IO path This removes the legacy (non-mq) IO path for SCSI. Cc: linux-scsi@vger.kernel.org Acked-by: Himanshu Madhani Reviewed-by: Hannes Reinecke Tested-by: Ming Lei Reviewed-by: Omar Sandoval Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe --- drivers/scsi/scsi_lib.c | 603 ++++-------------------------------------------- 1 file changed, 42 insertions(+), 561 deletions(-) (limited to 'drivers/scsi/scsi_lib.c') diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 8b0345924a92..651be30ba96a 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -168,8 +168,6 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) { struct scsi_device *device = cmd->device; - struct request_queue *q = device->request_queue; - unsigned long flags; SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, "Inserting command %p into mlqueue\n", cmd)); @@ -190,26 +188,20 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) * before blk_cleanup_queue() finishes. */ cmd->result = 0; - if (q->mq_ops) { - /* - * Before a SCSI command is dispatched, - * get_device(&sdev->sdev_gendev) is called and the host, - * target and device busy counters are increased. Since - * requeuing a request causes these actions to be repeated and - * since scsi_device_unbusy() has already been called, - * put_device(&device->sdev_gendev) must still be called. Call - * put_device() after blk_mq_requeue_request() to avoid that - * removal of the SCSI device can start before requeueing has - * happened. - */ - blk_mq_requeue_request(cmd->request, true); - put_device(&device->sdev_gendev); - return; - } - spin_lock_irqsave(q->queue_lock, flags); - blk_requeue_request(q, cmd->request); - kblockd_schedule_work(&device->requeue_work); - spin_unlock_irqrestore(q->queue_lock, flags); + + /* + * Before a SCSI command is dispatched, + * get_device(&sdev->sdev_gendev) is called and the host, + * target and device busy counters are increased. Since + * requeuing a request causes these actions to be repeated and + * since scsi_device_unbusy() has already been called, + * put_device(&device->sdev_gendev) must still be called. Call + * put_device() after blk_mq_requeue_request() to avoid that + * removal of the SCSI device can start before requeueing has + * happened. + */ + blk_mq_requeue_request(cmd->request, true); + put_device(&device->sdev_gendev); } /* @@ -370,10 +362,7 @@ void scsi_device_unbusy(struct scsi_device *sdev) static void scsi_kick_queue(struct request_queue *q) { - if (q->mq_ops) - blk_mq_run_hw_queues(q, false); - else - blk_run_queue(q); + blk_mq_run_hw_queues(q, false); } /* @@ -534,10 +523,7 @@ static void scsi_run_queue(struct request_queue *q) if (!list_empty(&sdev->host->starved_list)) scsi_starved_list_run(sdev->host); - if (q->mq_ops) - blk_mq_run_hw_queues(q, false); - else - blk_run_queue(q); + blk_mq_run_hw_queues(q, false); } void scsi_requeue_run_queue(struct work_struct *work) @@ -550,42 +536,6 @@ void scsi_requeue_run_queue(struct work_struct *work) scsi_run_queue(q); } -/* - * Function: scsi_requeue_command() - * - * Purpose: Handle post-processing of completed commands. - * - * Arguments: q - queue to operate on - * cmd - command that may need to be requeued. - * - * Returns: Nothing - * - * Notes: After command completion, there may be blocks left - * over which weren't finished by the previous command - * this can be for a number of reasons - the main one is - * I/O errors in the middle of the request, in which case - * we need to request the blocks that come after the bad - * sector. - * Notes: Upon return, cmd is a stale pointer. - */ -static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) -{ - struct scsi_device *sdev = cmd->device; - struct request *req = cmd->request; - unsigned long flags; - - spin_lock_irqsave(q->queue_lock, flags); - blk_unprep_request(req); - req->special = NULL; - scsi_put_command(cmd); - blk_requeue_request(q, req); - spin_unlock_irqrestore(q->queue_lock, flags); - - scsi_run_queue(q); - - put_device(&sdev->sdev_gendev); -} - void scsi_run_host_queues(struct Scsi_Host *shost) { struct scsi_device *sdev; @@ -626,42 +576,6 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) scsi_del_cmd_from_list(cmd); } -/* - * Function: scsi_release_buffers() - * - * Purpose: Free resources allocate for a scsi_command. - * - * Arguments: cmd - command that we are bailing. - * - * Lock status: Assumed that no lock is held upon entry. - * - * Returns: Nothing - * - * Notes: In the event that an upper level driver rejects a - * command, we must release resources allocated during - * the __init_io() function. Primarily this would involve - * the scatter-gather table. - */ -static void scsi_release_buffers(struct scsi_cmnd *cmd) -{ - if (cmd->sdb.table.nents) - sg_free_table_chained(&cmd->sdb.table, false); - - memset(&cmd->sdb, 0, sizeof(cmd->sdb)); - - if (scsi_prot_sg_count(cmd)) - sg_free_table_chained(&cmd->prot_sdb->table, false); -} - -static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) -{ - struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; - - sg_free_table_chained(&bidi_sdb->table, false); - kmem_cache_free(scsi_sdb_cache, bidi_sdb); - cmd->request->next_rq->special = NULL; -} - /* Returns false when no more bytes to process, true if there are more */ static bool scsi_end_request(struct request *req, blk_status_t error, unsigned int bytes, unsigned int bidi_bytes) @@ -687,37 +601,22 @@ static bool scsi_end_request(struct request *req, blk_status_t error, destroy_rcu_head(&cmd->rcu); } - if (req->mq_ctx) { - /* - * In the MQ case the command gets freed by __blk_mq_end_request, - * so we have to do all cleanup that depends on it earlier. - * - * We also can't kick the queues from irq context, so we - * will have to defer it to a workqueue. - */ - scsi_mq_uninit_cmd(cmd); - - __blk_mq_end_request(req, error); - - if (scsi_target(sdev)->single_lun || - !list_empty(&sdev->host->starved_list)) - kblockd_schedule_work(&sdev->requeue_work); - else - blk_mq_run_hw_queues(q, true); - } else { - unsigned long flags; - - if (bidi_bytes) - scsi_release_bidi_buffers(cmd); - scsi_release_buffers(cmd); - scsi_put_command(cmd); + /* + * In the MQ case the command gets freed by __blk_mq_end_request, + * so we have to do all cleanup that depends on it earlier. + * + * We also can't kick the queues from irq context, so we + * will have to defer it to a workqueue. + */ + scsi_mq_uninit_cmd(cmd); - spin_lock_irqsave(q->queue_lock, flags); - blk_finish_request(req, error); - spin_unlock_irqrestore(q->queue_lock, flags); + __blk_mq_end_request(req, error); - scsi_run_queue(q); - } + if (scsi_target(sdev)->single_lun || + !list_empty(&sdev->host->starved_list)) + kblockd_schedule_work(&sdev->requeue_work); + else + blk_mq_run_hw_queues(q, true); put_device(&sdev->sdev_gendev); return false; @@ -766,13 +665,7 @@ static void scsi_io_completion_reprep(struct scsi_cmnd *cmd, struct request_queue *q) { /* A new command will be prepared and issued. */ - if (q->mq_ops) { - scsi_mq_requeue_cmd(cmd); - } else { - /* Unprep request and put it back at head of the queue. */ - scsi_release_buffers(cmd); - scsi_requeue_command(q, cmd); - } + scsi_mq_requeue_cmd(cmd); } /* Helper for scsi_io_completion() when special action required. */ @@ -1147,9 +1040,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) */ int scsi_init_io(struct scsi_cmnd *cmd) { - struct scsi_device *sdev = cmd->device; struct request *rq = cmd->request; - bool is_mq = (rq->mq_ctx != NULL); int error = BLKPREP_KILL; if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq))) @@ -1160,17 +1051,6 @@ int scsi_init_io(struct scsi_cmnd *cmd) goto err_exit; if (blk_bidi_rq(rq)) { - if (!rq->q->mq_ops) { - struct scsi_data_buffer *bidi_sdb = - kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC); - if (!bidi_sdb) { - error = BLKPREP_DEFER; - goto err_exit; - } - - rq->next_rq->special = bidi_sdb; - } - error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special); if (error) goto err_exit; @@ -1210,14 +1090,7 @@ int scsi_init_io(struct scsi_cmnd *cmd) return BLKPREP_OK; err_exit: - if (is_mq) { - scsi_mq_free_sgtables(cmd); - } else { - scsi_release_buffers(cmd); - cmd->request->special = NULL; - scsi_put_command(cmd); - put_device(&sdev->sdev_gendev); - } + scsi_mq_free_sgtables(cmd); return error; } EXPORT_SYMBOL(scsi_init_io); @@ -1423,75 +1296,6 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req) return ret; } -static int -scsi_prep_return(struct request_queue *q, struct request *req, int ret) -{ - struct scsi_device *sdev = q->queuedata; - - switch (ret) { - case BLKPREP_KILL: - case BLKPREP_INVALID: - scsi_req(req)->result = DID_NO_CONNECT << 16; - /* release the command and kill it */ - if (req->special) { - struct scsi_cmnd *cmd = req->special; - scsi_release_buffers(cmd); - scsi_put_command(cmd); - put_device(&sdev->sdev_gendev); - req->special = NULL; - } - break; - case BLKPREP_DEFER: - /* - * If we defer, the blk_peek_request() returns NULL, but the - * queue must be restarted, so we schedule a callback to happen - * shortly. - */ - if (atomic_read(&sdev->device_busy) == 0) - blk_delay_queue(q, SCSI_QUEUE_DELAY); - break; - default: - req->rq_flags |= RQF_DONTPREP; - } - - return ret; -} - -static int scsi_prep_fn(struct request_queue *q, struct request *req) -{ - struct scsi_device *sdev = q->queuedata; - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); - int ret; - - ret = scsi_prep_state_check(sdev, req); - if (ret != BLKPREP_OK) - goto out; - - if (!req->special) { - /* Bail if we can't get a reference to the device */ - if (unlikely(!get_device(&sdev->sdev_gendev))) { - ret = BLKPREP_DEFER; - goto out; - } - - scsi_init_command(sdev, cmd); - req->special = cmd; - } - - cmd->tag = req->tag; - cmd->request = req; - cmd->prot_op = SCSI_PROT_NORMAL; - - ret = scsi_setup_cmnd(sdev, req); -out: - return scsi_prep_return(q, req, ret); -} - -static void scsi_unprep_fn(struct request_queue *q, struct request *req) -{ - scsi_uninit_cmd(blk_mq_rq_to_pdu(req)); -} - /* * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else * return 0. @@ -1511,14 +1315,8 @@ static inline int scsi_dev_queue_ready(struct request_queue *q, /* * unblock after device_blocked iterates to zero */ - if (atomic_dec_return(&sdev->device_blocked) > 0) { - /* - * For the MQ case we take care of this in the caller. - */ - if (!q->mq_ops) - blk_delay_queue(q, SCSI_QUEUE_DELAY); + if (atomic_dec_return(&sdev->device_blocked) > 0) goto out_dec; - } SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, "unblocking device at zero depth\n")); } @@ -1653,13 +1451,13 @@ out_dec: * needs to return 'not busy'. Otherwise, request stacking drivers * may hold requests forever. */ -static int scsi_lld_busy(struct request_queue *q) +static bool scsi_mq_lld_busy(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; if (blk_queue_dying(q)) - return 0; + return false; shost = sdev->host; @@ -1670,48 +1468,9 @@ static int scsi_lld_busy(struct request_queue *q) * in SCSI layer. */ if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) - return 1; - - return 0; -} - -static bool scsi_mq_lld_busy(struct request_queue *q) -{ - return scsi_lld_busy(q); -} - -/* - * Kill a request for a dead device - */ -static void scsi_kill_request(struct request *req, struct request_queue *q) -{ - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); - struct scsi_device *sdev; - struct scsi_target *starget; - struct Scsi_Host *shost; - - blk_start_request(req); - - scmd_printk(KERN_INFO, cmd, "killing request\n"); - - sdev = cmd->device; - starget = scsi_target(sdev); - shost = sdev->host; - scsi_init_cmd_errh(cmd); - cmd->result = DID_NO_CONNECT << 16; - atomic_inc(&cmd->device->iorequest_cnt); - - /* - * SCSI request completion path will do scsi_device_unbusy(), - * bump busy counts. To bump the counters, we need to dance - * with the locks as normal issue path does. - */ - atomic_inc(&sdev->device_busy); - atomic_inc(&shost->host_busy); - if (starget->can_queue > 0) - atomic_inc(&starget->target_busy); + return true; - blk_complete_request(req); + return false; } static void scsi_softirq_done(struct request *rq) @@ -1834,158 +1593,6 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) return 0; } -/** - * scsi_done - Invoke completion on finished SCSI command. - * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives - * ownership back to SCSI Core -- i.e. the LLDD has finished with it. - * - * Description: This function is the mid-level's (SCSI Core) interrupt routine, - * which regains ownership of the SCSI command (de facto) from a LLDD, and - * calls blk_complete_request() for further processing. - * - * This function is interrupt context safe. - */ -static void scsi_done(struct scsi_cmnd *cmd) -{ - trace_scsi_dispatch_cmd_done(cmd); - blk_complete_request(cmd->request); -} - -/* - * Function: scsi_request_fn() - * - * Purpose: Main strategy routine for SCSI. - * - * Arguments: q - Pointer to actual queue. - * - * Returns: Nothing - * - * Lock status: request queue lock assumed to be held when called. - * - * Note: See sd_zbc.c sd_zbc_write_lock_zone() for write order - * protection for ZBC disks. - */ -static void scsi_request_fn(struct request_queue *q) - __releases(q->queue_lock) - __acquires(q->queue_lock) -{ - struct scsi_device *sdev = q->queuedata; - struct Scsi_Host *shost; - struct scsi_cmnd *cmd; - struct request *req; - - /* - * To start with, we keep looping until the queue is empty, or until - * the host is no longer able to accept any more requests. - */ - shost = sdev->host; - for (;;) { - int rtn; - /* - * get next queueable request. We do this early to make sure - * that the request is fully prepared even if we cannot - * accept it. - */ - req = blk_peek_request(q); - if (!req) - break; - - if (unlikely(!scsi_device_online(sdev))) { - sdev_printk(KERN_ERR, sdev, - "rejecting I/O to offline device\n"); - scsi_kill_request(req, q); - continue; - } - - if (!scsi_dev_queue_ready(q, sdev)) - break; - - /* - * Remove the request from the request list. - */ - if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) - blk_start_request(req); - - spin_unlock_irq(q->queue_lock); - cmd = blk_mq_rq_to_pdu(req); - if (cmd != req->special) { - printk(KERN_CRIT "impossible request in %s.\n" - "please mail a stack trace to " - "linux-scsi@vger.kernel.org\n", - __func__); - blk_dump_rq_flags(req, "foo"); - BUG(); - } - - /* - * We hit this when the driver is using a host wide - * tag map. For device level tag maps the queue_depth check - * in the device ready fn would prevent us from trying - * to allocate a tag. Since the map is a shared host resource - * we add the dev to the starved list so it eventually gets - * a run when a tag is freed. - */ - if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) { - spin_lock_irq(shost->host_lock); - if (list_empty(&sdev->starved_entry)) - list_add_tail(&sdev->starved_entry, - &shost->starved_list); - spin_unlock_irq(shost->host_lock); - goto not_ready; - } - - if (!scsi_target_queue_ready(shost, sdev)) - goto not_ready; - - if (!scsi_host_queue_ready(q, shost, sdev)) - goto host_not_ready; - - if (sdev->simple_tags) - cmd->flags |= SCMD_TAGGED; - else - cmd->flags &= ~SCMD_TAGGED; - - /* - * Finally, initialize any error handling parameters, and set up - * the timers for timeouts. - */ - scsi_init_cmd_errh(cmd); - - /* - * Dispatch the command to the low-level driver. - */ - cmd->scsi_done = scsi_done; - rtn = scsi_dispatch_cmd(cmd); - if (rtn) { - scsi_queue_insert(cmd, rtn); - spin_lock_irq(q->queue_lock); - goto out_delay; - } - spin_lock_irq(q->queue_lock); - } - - return; - - host_not_ready: - if (scsi_target(sdev)->can_queue > 0) - atomic_dec(&scsi_target(sdev)->target_busy); - not_ready: - /* - * lock q, handle tag, requeue req, and decrement device_busy. We - * must return with queue_lock held. - * - * Decrementing device_busy without checking it is OK, as all such - * cases (host limits or settings) should run the queue at some - * later time. - */ - spin_lock_irq(q->queue_lock); - blk_requeue_request(q, req); - atomic_dec(&sdev->device_busy); -out_delay: - if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev)) - blk_delay_queue(q, SCSI_QUEUE_DELAY); -} - static inline blk_status_t prep_to_mq(int ret) { switch (ret) { @@ -2248,77 +1855,6 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) } EXPORT_SYMBOL_GPL(__scsi_init_queue); -static int scsi_old_init_rq(struct request_queue *q, struct request *rq, - gfp_t gfp) -{ - struct Scsi_Host *shost = q->rq_alloc_data; - const bool unchecked_isa_dma = shost->unchecked_isa_dma; - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); - - memset(cmd, 0, sizeof(*cmd)); - - if (unchecked_isa_dma) - cmd->flags |= SCMD_UNCHECKED_ISA_DMA; - cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp, - NUMA_NO_NODE); - if (!cmd->sense_buffer) - goto fail; - cmd->req.sense = cmd->sense_buffer; - - if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { - cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp); - if (!cmd->prot_sdb) - goto fail_free_sense; - } - - return 0; - -fail_free_sense: - scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer); -fail: - return -ENOMEM; -} - -static void scsi_old_exit_rq(struct request_queue *q, struct request *rq) -{ - struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); - - if (cmd->prot_sdb) - kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); - scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, - cmd->sense_buffer); -} - -struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev) -{ - struct Scsi_Host *shost = sdev->host; - struct request_queue *q; - - q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, NULL); - if (!q) - return NULL; - q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; - q->rq_alloc_data = shost; - q->request_fn = scsi_request_fn; - q->init_rq_fn = scsi_old_init_rq; - q->exit_rq_fn = scsi_old_exit_rq; - q->initialize_rq_fn = scsi_initialize_rq; - - if (blk_init_allocated_queue(q) < 0) { - blk_cleanup_queue(q); - return NULL; - } - - __scsi_init_queue(shost, q); - blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q); - blk_queue_prep_rq(q, scsi_prep_fn); - blk_queue_unprep_rq(q, scsi_unprep_fn); - blk_queue_softirq_done(q, scsi_softirq_done); - blk_queue_rq_timed_out(q, scsi_times_out); - blk_queue_lld_busy(q, scsi_lld_busy); - return q; -} - static const struct blk_mq_ops scsi_mq_ops = { .get_budget = scsi_mq_get_budget, .put_budget = scsi_mq_put_budget, @@ -2386,10 +1922,7 @@ struct scsi_device *scsi_device_from_queue(struct request_queue *q) { struct scsi_device *sdev = NULL; - if (q->mq_ops) { - if (q->mq_ops == &scsi_mq_ops) - sdev = q->queuedata; - } else if (q->request_fn == scsi_request_fn) + if (q->mq_ops == &scsi_mq_ops) sdev = q->queuedata; if (!sdev || !get_device(&sdev->sdev_gendev)) sdev = NULL; @@ -2992,39 +2525,6 @@ void sdev_evt_send_simple(struct scsi_device *sdev, } EXPORT_SYMBOL_GPL(sdev_evt_send_simple); -/** - * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() - * @sdev: SCSI device to count the number of scsi_request_fn() callers for. - */ -static int scsi_request_fn_active(struct scsi_device *sdev) -{ - struct request_queue *q = sdev->request_queue; - int request_fn_active; - - WARN_ON_ONCE(sdev->host->use_blk_mq); - - spin_lock_irq(q->queue_lock); - request_fn_active = q->request_fn_active; - spin_unlock_irq(q->queue_lock); - - return request_fn_active; -} - -/** - * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls - * @sdev: SCSI device pointer. - * - * Wait until the ongoing shost->hostt->queuecommand() calls that are - * invoked from scsi_request_fn() have finished. - */ -static void scsi_wait_for_queuecommand(struct scsi_device *sdev) -{ - WARN_ON_ONCE(sdev->host->use_blk_mq); - - while (scsi_request_fn_active(sdev)) - msleep(20); -} - /** * scsi_device_quiesce - Block user issued commands. * @sdev: scsi device to quiesce. @@ -3148,7 +2648,6 @@ EXPORT_SYMBOL(scsi_target_resume); int scsi_internal_device_block_nowait(struct scsi_device *sdev) { struct request_queue *q = sdev->request_queue; - unsigned long flags; int err = 0; err = scsi_device_set_state(sdev, SDEV_BLOCK); @@ -3164,14 +2663,7 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev) * block layer from calling the midlayer with this device's * request queue. */ - if (q->mq_ops) { - blk_mq_quiesce_queue_nowait(q); - } else { - spin_lock_irqsave(q->queue_lock, flags); - blk_stop_queue(q); - spin_unlock_irqrestore(q->queue_lock, flags); - } - + blk_mq_quiesce_queue_nowait(q); return 0; } EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); @@ -3202,12 +2694,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev) mutex_lock(&sdev->state_mutex); err = scsi_internal_device_block_nowait(sdev); - if (err == 0) { - if (q->mq_ops) - blk_mq_quiesce_queue(q); - else - scsi_wait_for_queuecommand(sdev); - } + if (err == 0) + blk_mq_quiesce_queue(q); mutex_unlock(&sdev->state_mutex); return err; @@ -3216,15 +2704,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev) void scsi_start_queue(struct scsi_device *sdev) { struct request_queue *q = sdev->request_queue; - unsigned long flags; - if (q->mq_ops) { - blk_mq_unquiesce_queue(q); - } else { - spin_lock_irqsave(q->queue_lock, flags); - blk_start_queue(q); - spin_unlock_irqrestore(q->queue_lock, flags); - } + blk_mq_unquiesce_queue(q); } /** -- cgit v1.2.3-59-g8ed1b