summaryrefslogtreecommitdiffstats
path: root/drivers/md/dm-cache-policy-internal.h
blob: 808ee0e2b2c4703d4dd837efde064f479966a5c1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 * Copyright (C) 2012 Red Hat. All rights reserved.
 *
 * This file is released under the GPL.
 */

#ifndef DM_CACHE_POLICY_INTERNAL_H
#define DM_CACHE_POLICY_INTERNAL_H

#include <linux/vmalloc.h>
#include "dm-cache-policy.h"

/*----------------------------------------------------------------*/

/*
 * Little inline functions that simplify calling the policy methods.
 */
static inline int policy_map(struct dm_cache_policy *p, dm_oblock_t oblock,
			     bool can_block, bool can_migrate, bool discarded_oblock,
			     struct bio *bio, struct policy_locker *locker,
			     struct policy_result *result)
{
	return p->map(p, oblock, can_block, can_migrate, discarded_oblock, bio, locker, result);
}

static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
{
	BUG_ON(!p->lookup);
	return p->lookup(p, oblock, cblock);
}

static inline void policy_set_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
{
	if (p->set_dirty)
		p->set_dirty(p, oblock);
}

static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
{
	if (p->clear_dirty)
		p->clear_dirty(p, oblock);
}

static inline int policy_load_mapping(struct dm_cache_policy *p,
				      dm_oblock_t oblock, dm_cblock_t cblock,
				      uint32_t hint, bool hint_valid)
{
	return p->load_mapping(p, oblock, cblock, hint, hint_valid);
}

static inline uint32_t policy_get_hint(struct dm_cache_policy *p,
				       dm_cblock_t cblock)
{
	return p->get_hint ? p->get_hint(p, cblock) : 0;
}

static inline int policy_writeback_work(struct dm_cache_policy *p,
					dm_oblock_t *oblock,
					dm_cblock_t *cblock,
					bool critical_only)
{
	return p->writeback_work ? p->writeback_work(p, oblock, cblock, critical_only) : -ENOENT;
}

static inline void policy_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock)
{
	p->remove_mapping(p, oblock);
}

static inline int policy_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)
{
	return p->remove_cblock(p, cblock);
}

static inline void policy_force_mapping(struct dm_cache_policy *p,
					dm_oblock_t current_oblock, dm_oblock_t new_oblock)
{
	return p->force_mapping(p, current_oblock, new_oblock);
}

static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
{
	return p->residency(p);
}

static inline void policy_tick(struct dm_cache_policy *p, bool can_block)
{
	if (p->tick)
		return p->tick(p, can_block);
}

static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result,
					    unsigned maxlen, ssize_t *sz_ptr)
{
	ssize_t sz = *sz_ptr;
	if (p->emit_config_values)
		return p->emit_config_values(p, result, maxlen, sz_ptr);

	DMEMIT("0 ");
	*sz_ptr = sz;
	return 0;
}

static inline int policy_set_config_value(struct dm_cache_policy *p,
					  const char *key, const char *value)
{
	return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
}

/*----------------------------------------------------------------*/

/*
 * Some utility functions commonly used by policies and the core target.
 */
static inline size_t bitset_size_in_bytes(unsigned nr_entries)
{
	return sizeof(unsigned long) * dm_div_up(nr_entries, BITS_PER_LONG);
}

static inline unsigned long *alloc_bitset(unsigned nr_entries)
{
	size_t s = bitset_size_in_bytes(nr_entries);
	return vzalloc(s);
}

static inline void clear_bitset(void *bitset, unsigned nr_entries)
{
	size_t s = bitset_size_in_bytes(nr_entries);
	memset(bitset, 0, s);
}

static inline void free_bitset(unsigned long *bits)
{
	vfree(bits);
}

/*----------------------------------------------------------------*/

/*
 * Creates a new cache policy given a policy name, a cache size, an origin size and the block size.
 */
struct dm_cache_policy *dm_cache_policy_create(const char *name, dm_cblock_t cache_size,
					       sector_t origin_size, sector_t block_size);

/*
 * Destroys the policy.  This drops references to the policy module as well
 * as calling it's destroy method.  So always use this rather than calling
 * the policy->destroy method directly.
 */
void dm_cache_policy_destroy(struct dm_cache_policy *p);

/*
 * In case we've forgotten.
 */
const char *dm_cache_policy_get_name(struct dm_cache_policy *p);

const unsigned *dm_cache_policy_get_version(struct dm_cache_policy *p);

size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);

/*----------------------------------------------------------------*/

#endif /* DM_CACHE_POLICY_INTERNAL_H */