xref: /linux/drivers/md/dm-rq.h (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
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 	blk_status_t error;
28 	union map_info info;
29 	struct dm_stats_aux stats_aux;
30 	unsigned long duration_jiffies;
31 	unsigned n_sectors;
32 	unsigned completed;
33 };
34 
35 /*
36  * For request-based dm - the bio clones we allocate are embedded in these
37  * structs.
38  *
39  * We allocate these with bio_alloc_bioset, using the front_pad parameter when
40  * the bioset is created - this means the bio has to come at the end of the
41  * struct.
42  */
43 struct dm_rq_clone_bio_info {
44 	struct bio *orig;
45 	struct dm_rq_target_io *tio;
46 	struct bio clone;
47 };
48 
49 bool dm_use_blk_mq_default(void);
50 bool dm_use_blk_mq(struct mapped_device *md);
51 
52 int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t);
53 int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t);
54 void dm_mq_cleanup_mapped_device(struct mapped_device *md);
55 
56 void dm_start_queue(struct request_queue *q);
57 void dm_stop_queue(struct request_queue *q);
58 
59 void dm_mq_kick_requeue_list(struct mapped_device *md);
60 
61 unsigned dm_get_reserved_rq_based_ios(void);
62 
63 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
64 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
65 						     const char *buf, size_t count);
66 
67 #endif
68