| /* |
| * Functions related to setting various queue properties from drivers |
| */ |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/bio.h> |
| #include <linux/blkdev.h> |
| #include <linux/blk-mq.h> |
| #include <linux/sched/sysctl.h> |
| |
| #include "blk.h" |
| #include "blk-mq-sched.h" |
| |
| /* |
| * for max sense size |
| */ |
| #include <scsi/scsi_cmnd.h> |
| |
| /** |
| * blk_end_sync_rq - executes a completion event on a request |
| * @rq: request to complete |
| * @error: end I/O status of the request |
| */ |
| static void blk_end_sync_rq(struct request *rq, int error) |
| { |
| struct completion *waiting = rq->end_io_data; |
| |
| rq->end_io_data = NULL; |
| |
| /* |
| * complete last, if this is a stack request the process (and thus |
| * the rq pointer) could be invalid right after this complete() |
| */ |
| complete(waiting); |
| } |
| |
| /** |
| * blk_execute_rq_nowait - insert a request into queue for execution |
| * @q: queue to insert the request in |
| * @bd_disk: matching gendisk |
| * @rq: request to insert |
| * @at_head: insert request at head or tail of queue |
| * @done: I/O completion handler |
| * |
| * Description: |
| * Insert a fully prepared request at the back of the I/O scheduler queue |
| * for execution. Don't wait for completion. |
| * |
| * Note: |
| * This function will invoke @done directly if the queue is dead. |
| */ |
| void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, |
| struct request *rq, int at_head, |
| rq_end_io_fn *done) |
| { |
| int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; |
| |
| WARN_ON(irqs_disabled()); |
| WARN_ON(rq->cmd_type == REQ_TYPE_FS); |
| |
| rq->rq_disk = bd_disk; |
| rq->end_io = done; |
| |
| /* |
| * don't check dying flag for MQ because the request won't |
| * be reused after dying flag is set |
| */ |
| if (q->mq_ops) { |
| blk_mq_sched_insert_request(rq, at_head, true, false, false); |
| return; |
| } |
| |
| spin_lock_irq(q->queue_lock); |
| |
| if (unlikely(blk_queue_dying(q))) { |
| rq->rq_flags |= RQF_QUIET; |
| rq->errors = -ENXIO; |
| __blk_end_request_all(rq, rq->errors); |
| spin_unlock_irq(q->queue_lock); |
| return; |
| } |
| |
| __elv_add_request(q, rq, where); |
| __blk_run_queue(q); |
| spin_unlock_irq(q->queue_lock); |
| } |
| EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); |
| |
| /** |
| * blk_execute_rq - insert a request into queue for execution |
| * @q: queue to insert the request in |
| * @bd_disk: matching gendisk |
| * @rq: request to insert |
| * @at_head: insert request at head or tail of queue |
| * |
| * Description: |
| * Insert a fully prepared request at the back of the I/O scheduler queue |
| * for execution and wait for completion. |
| */ |
| int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, |
| struct request *rq, int at_head) |
| { |
| DECLARE_COMPLETION_ONSTACK(wait); |
| char sense[SCSI_SENSE_BUFFERSIZE]; |
| int err = 0; |
| unsigned long hang_check; |
| |
| if (!rq->sense) { |
| memset(sense, 0, sizeof(sense)); |
| rq->sense = sense; |
| rq->sense_len = 0; |
| } |
| |
| rq->end_io_data = &wait; |
| blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq); |
| |
| /* Prevent hang_check timer from firing at us during very long I/O */ |
| hang_check = sysctl_hung_task_timeout_secs; |
| if (hang_check) |
| while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2))); |
| else |
| wait_for_completion_io(&wait); |
| |
| if (rq->errors) |
| err = -EIO; |
| |
| if (rq->sense == sense) { |
| rq->sense = NULL; |
| rq->sense_len = 0; |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL(blk_execute_rq); |