xref: /linux/drivers/md/dm-rq.h (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda)
1 /*
2  * Internal header file for device mapper
3  *
4  * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
5  *
6  * This file is released under the LGPL.
7  */
8 
9 #ifndef DM_RQ_INTERNAL_H
10 #define DM_RQ_INTERNAL_H
11 
12 #include <linux/bio.h>
13 #include <linux/kthread.h>
14 
15 #include "dm-stats.h"
16 
17 struct mapped_device;
18 
19 /*
20  * One of these is allocated per request.
21  */
22 struct dm_rq_target_io {
23 	struct mapped_device *md;
24 	struct dm_target *ti;
25 	struct request *orig, *clone;
26 	struct kthread_work work;
27 	int error;
28 	union map_info info;
29 	struct dm_stats_aux stats_aux;
30 	unsigned long duration_jiffies;
31 	unsigned n_sectors;
32 };
33 
34 /*
35  * For request-based dm - the bio clones we allocate are embedded in these
36  * structs.
37  *
38  * We allocate these with bio_alloc_bioset, using the front_pad parameter when
39  * the bioset is created - this means the bio has to come at the end of the
40  * struct.
41  */
42 struct dm_rq_clone_bio_info {
43 	struct bio *orig;
44 	struct dm_rq_target_io *tio;
45 	struct bio clone;
46 };
47 
48 bool dm_use_blk_mq_default(void);
49 bool dm_use_blk_mq(struct mapped_device *md);
50 
51 int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t);
52 int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t);
53 void dm_mq_cleanup_mapped_device(struct mapped_device *md);
54 
55 void dm_start_queue(struct request_queue *q);
56 void dm_stop_queue(struct request_queue *q);
57 
58 void dm_mq_kick_requeue_list(struct mapped_device *md);
59 
60 unsigned dm_get_reserved_rq_based_ios(void);
61 
62 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
63 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
64 						     const char *buf, size_t count);
65 
66 #endif
67