1 // SPDX-License-Identifier: GPL-2.0
3 * Functions related to setting various queue properties from drivers
5 #include <linux/kernel.h>
6 #include <linux/module.h>
8 #include <linux/blkdev.h>
9 #include <linux/blk-mq.h>
10 #include <linux/sched/sysctl.h>
13 #include "blk-mq-sched.h"
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
20 static void blk_end_sync_rq(struct request
*rq
, blk_status_t error
)
22 struct completion
*waiting
= rq
->end_io_data
;
24 rq
->end_io_data
= (void *)(uintptr_t)error
;
27 * complete last, if this is a stack request the process (and thus
28 * the rq pointer) could be invalid right after this complete()
34 * blk_execute_rq_nowait - insert a request to I/O scheduler for execution
35 * @bd_disk: matching gendisk
36 * @rq: request to insert
37 * @at_head: insert request at head or tail of queue
38 * @done: I/O completion handler
41 * Insert a fully prepared request at the back of the I/O scheduler queue
42 * for execution. Don't wait for completion.
45 * This function will invoke @done directly if the queue is dead.
47 void blk_execute_rq_nowait(struct gendisk
*bd_disk
, struct request
*rq
,
48 int at_head
, rq_end_io_fn
*done
)
50 WARN_ON(irqs_disabled());
51 WARN_ON(!blk_rq_is_passthrough(rq
));
53 rq
->rq_disk
= bd_disk
;
56 blk_account_io_start(rq
);
59 * don't check dying flag for MQ because the request won't
60 * be reused after dying flag is set
62 blk_mq_sched_insert_request(rq
, at_head
, true, false);
64 EXPORT_SYMBOL_GPL(blk_execute_rq_nowait
);
66 static bool blk_rq_is_poll(struct request
*rq
)
68 return rq
->mq_hctx
&& rq
->mq_hctx
->type
== HCTX_TYPE_POLL
;
71 static void blk_rq_poll_completion(struct request
*rq
, struct completion
*wait
)
74 blk_poll(rq
->q
, request_to_qc_t(rq
->mq_hctx
, rq
), true);
76 } while (!completion_done(wait
));
80 * blk_execute_rq - insert a request into queue for execution
81 * @bd_disk: matching gendisk
82 * @rq: request to insert
83 * @at_head: insert request at head or tail of queue
86 * Insert a fully prepared request at the back of the I/O scheduler queue
87 * for execution and wait for completion.
88 * Return: The blk_status_t result provided to blk_mq_end_request().
90 blk_status_t
blk_execute_rq(struct gendisk
*bd_disk
, struct request
*rq
, int at_head
)
92 DECLARE_COMPLETION_ONSTACK(wait
);
93 unsigned long hang_check
;
95 rq
->end_io_data
= &wait
;
96 blk_execute_rq_nowait(bd_disk
, rq
, at_head
, blk_end_sync_rq
);
98 /* Prevent hang_check timer from firing at us during very long I/O */
99 hang_check
= sysctl_hung_task_timeout_secs
;
101 if (blk_rq_is_poll(rq
))
102 blk_rq_poll_completion(rq
, &wait
);
104 while (!wait_for_completion_io_timeout(&wait
, hang_check
* (HZ
/2)));
106 wait_for_completion_io(&wait
);
108 return (blk_status_t
)(uintptr_t)rq
->end_io_data
;
110 EXPORT_SYMBOL(blk_execute_rq
);