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));
* 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);
}
/*
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);
}
/*
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)
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;
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)
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;
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. */
*/
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)))
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;
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);
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.
/*
* 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"));
}
* 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;
* 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)
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) {
}
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,
{
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;
}
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.
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);
* 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);
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;
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);
}
/**
projects / openwrt / staging / blogic.git / commitdiff