| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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" |
| |
| /** |
| * 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, blk_status_t error) |
| { |
| struct completion *waiting = rq->end_io_data; |
| |
| rq->end_io_data = (void *)(uintptr_t)error; |
| |
| /* |
| * 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 to I/O scheduler for execution |
| * @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 gendisk *bd_disk, struct request *rq, |
| int at_head, rq_end_io_fn *done) |
| { |
| WARN_ON(irqs_disabled()); |
| WARN_ON(!blk_rq_is_passthrough(rq)); |
| |
| rq->rq_disk = bd_disk; |
| rq->end_io = done; |
| |
| blk_account_io_start(rq); |
| |
| /* |
| * don't check dying flag for MQ because the request won't |
| * be reused after dying flag is set |
| */ |
| blk_mq_sched_insert_request(rq, at_head, true, false); |
| } |
| EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); |
| |
| static bool blk_rq_is_poll(struct request *rq) |
| { |
| return rq->mq_hctx && rq->mq_hctx->type == HCTX_TYPE_POLL; |
| } |
| |
| static void blk_rq_poll_completion(struct request *rq, struct completion *wait) |
| { |
| do { |
| blk_poll(rq->q, request_to_qc_t(rq->mq_hctx, rq), 0); |
| cond_resched(); |
| } while (!completion_done(wait)); |
| } |
| |
| /** |
| * blk_execute_rq - insert a request into queue for execution |
| * @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. |
| * Return: The blk_status_t result provided to blk_mq_end_request(). |
| */ |
| blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head) |
| { |
| DECLARE_COMPLETION_ONSTACK(wait); |
| unsigned long hang_check; |
| |
| rq->end_io_data = &wait; |
| blk_execute_rq_nowait(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 (blk_rq_is_poll(rq)) |
| blk_rq_poll_completion(rq, &wait); |
| else if (hang_check) |
| while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2))); |
| else |
| wait_for_completion_io(&wait); |
| |
| return (blk_status_t)(uintptr_t)rq->end_io_data; |
| } |
| EXPORT_SYMBOL(blk_execute_rq); |