1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Functions related to setting various queue properties from drivers 4 */ 5#include <linux/kernel.h> 6#include <linux/module.h> 7#include <linux/bio.h> 8#include <linux/blkdev.h> 9#include <linux/blk-mq.h> 10#include <linux/sched/sysctl.h> 11 12#include "blk.h" 13#include "blk-mq-sched.h" 14 15/** 16 * blk_end_sync_rq - executes a completion event on a request 17 * @rq: request to complete 18 * @error: end I/O status of the request 19 */ 20static void blk_end_sync_rq(struct request *rq, blk_status_t error) 21{ 22 struct completion *waiting = rq->end_io_data; 23 24 rq->end_io_data = (void *)(uintptr_t)error; 25 26 /* 27 * complete last, if this is a stack request the process (and thus 28 * the rq pointer) could be invalid right after this complete() 29 */ 30 complete(waiting); 31} 32 33/** 34 * blk_execute_rq_nowait - insert a request into queue for execution 35 * @q: queue to insert the request in 36 * @bd_disk: matching gendisk 37 * @rq: request to insert 38 * @at_head: insert request at head or tail of queue 39 * @done: I/O completion handler 40 * 41 * Description: 42 * Insert a fully prepared request at the back of the I/O scheduler queue 43 * for execution. Don't wait for completion. 44 * 45 * Note: 46 * This function will invoke @done directly if the queue is dead. 47 */ 48void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, 49 struct request *rq, int at_head, 50 rq_end_io_fn *done) 51{ 52 WARN_ON(irqs_disabled()); 53 WARN_ON(!blk_rq_is_passthrough(rq)); 54 55 rq->rq_disk = bd_disk; 56 rq->end_io = done; 57 58 blk_account_io_start(rq); 59 60 /* 61 * don't check dying flag for MQ because the request won't 62 * be reused after dying flag is set 63 */ 64 blk_mq_sched_insert_request(rq, at_head, true, false); 65} 66EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); 67 68/** 69 * blk_execute_rq - insert a request into queue for execution 70 * @q: queue to insert the request in 71 * @bd_disk: matching gendisk 72 * @rq: request to insert 73 * @at_head: insert request at head or tail of queue 74 * 75 * Description: 76 * Insert a fully prepared request at the back of the I/O scheduler queue 77 * for execution and wait for completion. 78 * Return: The blk_status_t result provided to blk_mq_end_request(). 79 */ 80blk_status_t blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, 81 struct request *rq, int at_head) 82{ 83 DECLARE_COMPLETION_ONSTACK(wait); 84 unsigned long hang_check; 85 86 rq->end_io_data = &wait; 87 blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq); 88 89 /* Prevent hang_check timer from firing at us during very long I/O */ 90 hang_check = sysctl_hung_task_timeout_secs; 91 if (hang_check) 92 while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2))); 93 else 94 wait_for_completion_io(&wait); 95 96 return (blk_status_t)(uintptr_t)rq->end_io_data; 97} 98EXPORT_SYMBOL(blk_execute_rq); 99