2 * Functions related to setting various queue properties from drivers
4 #include <linux/kernel.h>
5 #include <linux/module.h>
7 #include <linux/blkdev.h>
8 #include <linux/blk-mq.h>
9 #include <linux/sched/sysctl.h>
16 #include <scsi/scsi_cmnd.h>
19 * blk_end_sync_rq - executes a completion event on a request
20 * @rq: request to complete
21 * @error: end I/O status of the request
23 static void blk_end_sync_rq(struct request
*rq
, int error
)
25 struct completion
*waiting
= rq
->end_io_data
;
27 rq
->end_io_data
= NULL
;
30 * complete last, if this is a stack request the process (and thus
31 * the rq pointer) could be invalid right after this complete()
37 * blk_execute_rq_nowait - insert a request into queue for execution
38 * @q: queue to insert the request in
39 * @bd_disk: matching gendisk
40 * @rq: request to insert
41 * @at_head: insert request at head or tail of queue
42 * @done: I/O completion handler
45 * Insert a fully prepared request at the back of the I/O scheduler queue
46 * for execution. Don't wait for completion.
49 * This function will invoke @done directly if the queue is dead.
51 void blk_execute_rq_nowait(struct request_queue
*q
, struct gendisk
*bd_disk
,
52 struct request
*rq
, int at_head
,
55 int where
= at_head
? ELEVATOR_INSERT_FRONT
: ELEVATOR_INSERT_BACK
;
58 WARN_ON(irqs_disabled());
60 rq
->rq_disk
= bd_disk
;
64 * don't check dying flag for MQ because the request won't
65 * be resued after dying flag is set
68 blk_mq_insert_request(q
, rq
, true);
73 * need to check this before __blk_run_queue(), because rq can
74 * be freed before that returns.
76 is_pm_resume
= rq
->cmd_type
== REQ_TYPE_PM_RESUME
;
78 spin_lock_irq(q
->queue_lock
);
80 if (unlikely(blk_queue_dying(q
))) {
81 rq
->cmd_flags
|= REQ_QUIET
;
83 __blk_end_request_all(rq
, rq
->errors
);
84 spin_unlock_irq(q
->queue_lock
);
88 __elv_add_request(q
, rq
, where
);
90 /* the queue is stopped so it won't be run */
92 __blk_run_queue_uncond(q
);
93 spin_unlock_irq(q
->queue_lock
);
95 EXPORT_SYMBOL_GPL(blk_execute_rq_nowait
);
98 * blk_execute_rq - insert a request into queue for execution
99 * @q: queue to insert the request in
100 * @bd_disk: matching gendisk
101 * @rq: request to insert
102 * @at_head: insert request at head or tail of queue
105 * Insert a fully prepared request at the back of the I/O scheduler queue
106 * for execution and wait for completion.
108 int blk_execute_rq(struct request_queue
*q
, struct gendisk
*bd_disk
,
109 struct request
*rq
, int at_head
)
111 DECLARE_COMPLETION_ONSTACK(wait
);
112 char sense
[SCSI_SENSE_BUFFERSIZE
];
114 unsigned long hang_check
;
117 memset(sense
, 0, sizeof(sense
));
122 rq
->end_io_data
= &wait
;
123 blk_execute_rq_nowait(q
, bd_disk
, rq
, at_head
, blk_end_sync_rq
);
125 /* Prevent hang_check timer from firing at us during very long I/O */
126 hang_check
= sysctl_hung_task_timeout_secs
;
128 while (!wait_for_completion_io_timeout(&wait
, hang_check
* (HZ
/2)));
130 wait_for_completion_io(&wait
);
137 EXPORT_SYMBOL(blk_execute_rq
);