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1/*
2 * Functions related to setting various queue properties from drivers
3 */
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/bio.h>
7#include <linux/blkdev.h>
8
9#include "blk.h"
10
11/*
12 * for max sense size
13 */
14#include <scsi/scsi_cmnd.h>
15
16/**
17 * blk_end_sync_rq - executes a completion event on a request
18 * @rq: request to complete
19 * @error: end I/O status of the request
20 */
21static void blk_end_sync_rq(struct request *rq, int error)
22{
23 struct completion *waiting = rq->end_io_data;
24
25 rq->end_io_data = NULL;
26 __blk_put_request(rq->q, rq);
27
28 /*
29 * complete last, if this is a stack request the process (and thus
30 * the rq pointer) could be invalid right after this complete()
31 */
32 complete(waiting);
33}
34
35/**
36 * blk_execute_rq_nowait - insert a request into queue for execution
37 * @q: queue to insert the request in
38 * @bd_disk: matching gendisk
39 * @rq: request to insert
40 * @at_head: insert request at head or tail of queue
41 * @done: I/O completion handler
42 *
43 * Description:
44 * Insert a fully prepared request at the back of the I/O scheduler queue
45 * for execution. Don't wait for completion.
46 */
47void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
48 struct request *rq, int at_head,
49 rq_end_io_fn *done)
50{
51 int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
52
53 WARN_ON(irqs_disabled());
54 spin_lock_irq(q->queue_lock);
55
56 if (unlikely(blk_queue_dead(q))) {
57 spin_unlock_irq(q->queue_lock);
58 rq->errors = -ENXIO;
59 if (rq->end_io)
60 rq->end_io(rq, rq->errors);
61 return;
62 }
63
64 rq->rq_disk = bd_disk;
65 rq->end_io = done;
66 __elv_add_request(q, rq, where);
67 __blk_run_queue(q);
68 /* the queue is stopped so it won't be run */
69 if (rq->cmd_type == REQ_TYPE_PM_RESUME)
70 q->request_fn(q);
71 spin_unlock_irq(q->queue_lock);
72}
73EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
74
75/**
76 * blk_execute_rq - insert a request into queue for execution
77 * @q: queue to insert the request in
78 * @bd_disk: matching gendisk
79 * @rq: request to insert
80 * @at_head: insert request at head or tail of queue
81 *
82 * Description:
83 * Insert a fully prepared request at the back of the I/O scheduler queue
84 * for execution and wait for completion.
85 */
86int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
87 struct request *rq, int at_head)
88{
89 DECLARE_COMPLETION_ONSTACK(wait);
90 char sense[SCSI_SENSE_BUFFERSIZE];
91 int err = 0;
92 unsigned long hang_check;
93
94 /*
95 * we need an extra reference to the request, so we can look at
96 * it after io completion
97 */
98 rq->ref_count++;
99
100 if (!rq->sense) {
101 memset(sense, 0, sizeof(sense));
102 rq->sense = sense;
103 rq->sense_len = 0;
104 }
105
106 rq->end_io_data = &wait;
107 blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
108
109 /* Prevent hang_check timer from firing at us during very long I/O */
110 hang_check = sysctl_hung_task_timeout_secs;
111 if (hang_check)
112 while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
113 else
114 wait_for_completion(&wait);
115
116 if (rq->errors)
117 err = -EIO;
118
119 return err;
120}
121EXPORT_SYMBOL(blk_execute_rq);
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 = NULL;
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 /*
59 * don't check dying flag for MQ because the request won't
60 * be reused after dying flag is set
61 */
62 blk_mq_sched_insert_request(rq, at_head, true, false);
63}
64EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
65
66/**
67 * blk_execute_rq - insert a request into queue for execution
68 * @q: queue to insert the request in
69 * @bd_disk: matching gendisk
70 * @rq: request to insert
71 * @at_head: insert request at head or tail of queue
72 *
73 * Description:
74 * Insert a fully prepared request at the back of the I/O scheduler queue
75 * for execution and wait for completion.
76 */
77void blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
78 struct request *rq, int at_head)
79{
80 DECLARE_COMPLETION_ONSTACK(wait);
81 unsigned long hang_check;
82
83 rq->end_io_data = &wait;
84 blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
85
86 /* Prevent hang_check timer from firing at us during very long I/O */
87 hang_check = sysctl_hung_task_timeout_secs;
88 if (hang_check)
89 while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
90 else
91 wait_for_completion_io(&wait);
92}
93EXPORT_SYMBOL(blk_execute_rq);