Commit | Line | Data |
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86db1e29 JA |
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 io status of the request | |
20 | */ | |
21 | 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 | EXPORT_SYMBOL(blk_end_sync_rq); | |
35 | ||
36 | /** | |
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 | |
43 | * | |
44 | * Description: | |
45 | * Insert a fully prepared request at the back of the io scheduler queue | |
46 | * for execution. Don't wait for completion. | |
47 | */ | |
48 | void 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 | int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; | |
53 | ||
54 | rq->rq_disk = bd_disk; | |
55 | rq->cmd_flags |= REQ_NOMERGE; | |
56 | rq->end_io = done; | |
57 | WARN_ON(irqs_disabled()); | |
58 | spin_lock_irq(q->queue_lock); | |
59 | __elv_add_request(q, rq, where, 1); | |
60 | __generic_unplug_device(q); | |
61 | spin_unlock_irq(q->queue_lock); | |
62 | } | |
63 | EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); | |
64 | ||
65 | /** | |
66 | * blk_execute_rq - insert a request into queue for execution | |
67 | * @q: queue to insert the request in | |
68 | * @bd_disk: matching gendisk | |
69 | * @rq: request to insert | |
70 | * @at_head: insert request at head or tail of queue | |
71 | * | |
72 | * Description: | |
73 | * Insert a fully prepared request at the back of the io scheduler queue | |
74 | * for execution and wait for completion. | |
75 | */ | |
76 | int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, | |
77 | struct request *rq, int at_head) | |
78 | { | |
79 | DECLARE_COMPLETION_ONSTACK(wait); | |
80 | char sense[SCSI_SENSE_BUFFERSIZE]; | |
81 | int err = 0; | |
82 | ||
83 | /* | |
84 | * we need an extra reference to the request, so we can look at | |
85 | * it after io completion | |
86 | */ | |
87 | rq->ref_count++; | |
88 | ||
89 | if (!rq->sense) { | |
90 | memset(sense, 0, sizeof(sense)); | |
91 | rq->sense = sense; | |
92 | rq->sense_len = 0; | |
93 | } | |
94 | ||
95 | rq->end_io_data = &wait; | |
96 | blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq); | |
97 | wait_for_completion(&wait); | |
98 | ||
99 | if (rq->errors) | |
100 | err = -EIO; | |
101 | ||
102 | return err; | |
103 | } | |
86db1e29 | 104 | EXPORT_SYMBOL(blk_execute_rq); |