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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
4 * Copyright (C) 2006-2008 Red Hat GmbH
5 *
6 * This file is released under the GPL.
7 */
8
9#include "dm-exception-store.h"
10
11#include <linux/mm.h>
12#include <linux/pagemap.h>
13#include <linux/vmalloc.h>
14#include <linux/export.h>
15#include <linux/slab.h>
16#include <linux/dm-io.h>
17
18#define DM_MSG_PREFIX "transient snapshot"
19
20/*
21 *---------------------------------------------------------------
22 * Implementation of the store for non-persistent snapshots.
23 *---------------------------------------------------------------
24 */
25struct transient_c {
26 sector_t next_free;
27};
28
29static void transient_dtr(struct dm_exception_store *store)
30{
31 kfree(store->context);
32}
33
34static int transient_read_metadata(struct dm_exception_store *store,
35 int (*callback)(void *callback_context,
36 chunk_t old, chunk_t new),
37 void *callback_context)
38{
39 return 0;
40}
41
42static int transient_prepare_exception(struct dm_exception_store *store,
43 struct dm_exception *e)
44{
45 struct transient_c *tc = store->context;
46 sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
47
48 if (size < (tc->next_free + store->chunk_size))
49 return -1;
50
51 e->new_chunk = sector_to_chunk(store, tc->next_free);
52 tc->next_free += store->chunk_size;
53
54 return 0;
55}
56
57static void transient_commit_exception(struct dm_exception_store *store,
58 struct dm_exception *e, int valid,
59 void (*callback)(void *, int success),
60 void *callback_context)
61{
62 /* Just succeed */
63 callback(callback_context, valid);
64}
65
66static void transient_usage(struct dm_exception_store *store,
67 sector_t *total_sectors,
68 sector_t *sectors_allocated,
69 sector_t *metadata_sectors)
70{
71 *sectors_allocated = ((struct transient_c *) store->context)->next_free;
72 *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
73 *metadata_sectors = 0;
74}
75
76static int transient_ctr(struct dm_exception_store *store, char *options)
77{
78 struct transient_c *tc;
79
80 tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
81 if (!tc)
82 return -ENOMEM;
83
84 tc->next_free = 0;
85 store->context = tc;
86
87 return 0;
88}
89
90static unsigned int transient_status(struct dm_exception_store *store,
91 status_type_t status, char *result,
92 unsigned int maxlen)
93{
94 unsigned int sz = 0;
95
96 switch (status) {
97 case STATUSTYPE_INFO:
98 break;
99 case STATUSTYPE_TABLE:
100 DMEMIT(" N %llu", (unsigned long long)store->chunk_size);
101 break;
102 case STATUSTYPE_IMA:
103 *result = '\0';
104 break;
105 }
106
107 return sz;
108}
109
110static struct dm_exception_store_type _transient_type = {
111 .name = "transient",
112 .module = THIS_MODULE,
113 .ctr = transient_ctr,
114 .dtr = transient_dtr,
115 .read_metadata = transient_read_metadata,
116 .prepare_exception = transient_prepare_exception,
117 .commit_exception = transient_commit_exception,
118 .usage = transient_usage,
119 .status = transient_status,
120};
121
122static struct dm_exception_store_type _transient_compat_type = {
123 .name = "N",
124 .module = THIS_MODULE,
125 .ctr = transient_ctr,
126 .dtr = transient_dtr,
127 .read_metadata = transient_read_metadata,
128 .prepare_exception = transient_prepare_exception,
129 .commit_exception = transient_commit_exception,
130 .usage = transient_usage,
131 .status = transient_status,
132};
133
134int dm_transient_snapshot_init(void)
135{
136 int r;
137
138 r = dm_exception_store_type_register(&_transient_type);
139 if (r) {
140 DMWARN("Unable to register transient exception store type");
141 return r;
142 }
143
144 r = dm_exception_store_type_register(&_transient_compat_type);
145 if (r) {
146 DMWARN("Unable to register old-style transient exception store type");
147 dm_exception_store_type_unregister(&_transient_type);
148 return r;
149 }
150
151 return r;
152}
153
154void dm_transient_snapshot_exit(void)
155{
156 dm_exception_store_type_unregister(&_transient_type);
157 dm_exception_store_type_unregister(&_transient_compat_type);
158}
1/*
2 * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2006-2008 Red Hat GmbH
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-exception-store.h"
9
10#include <linux/mm.h>
11#include <linux/pagemap.h>
12#include <linux/vmalloc.h>
13#include <linux/export.h>
14#include <linux/slab.h>
15#include <linux/dm-io.h>
16
17#define DM_MSG_PREFIX "transient snapshot"
18
19/*-----------------------------------------------------------------
20 * Implementation of the store for non-persistent snapshots.
21 *---------------------------------------------------------------*/
22struct transient_c {
23 sector_t next_free;
24};
25
26static void transient_dtr(struct dm_exception_store *store)
27{
28 kfree(store->context);
29}
30
31static int transient_read_metadata(struct dm_exception_store *store,
32 int (*callback)(void *callback_context,
33 chunk_t old, chunk_t new),
34 void *callback_context)
35{
36 return 0;
37}
38
39static int transient_prepare_exception(struct dm_exception_store *store,
40 struct dm_exception *e)
41{
42 struct transient_c *tc = store->context;
43 sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
44
45 if (size < (tc->next_free + store->chunk_size))
46 return -1;
47
48 e->new_chunk = sector_to_chunk(store, tc->next_free);
49 tc->next_free += store->chunk_size;
50
51 return 0;
52}
53
54static void transient_commit_exception(struct dm_exception_store *store,
55 struct dm_exception *e, int valid,
56 void (*callback) (void *, int success),
57 void *callback_context)
58{
59 /* Just succeed */
60 callback(callback_context, valid);
61}
62
63static void transient_usage(struct dm_exception_store *store,
64 sector_t *total_sectors,
65 sector_t *sectors_allocated,
66 sector_t *metadata_sectors)
67{
68 *sectors_allocated = ((struct transient_c *) store->context)->next_free;
69 *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
70 *metadata_sectors = 0;
71}
72
73static int transient_ctr(struct dm_exception_store *store, char *options)
74{
75 struct transient_c *tc;
76
77 tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
78 if (!tc)
79 return -ENOMEM;
80
81 tc->next_free = 0;
82 store->context = tc;
83
84 return 0;
85}
86
87static unsigned transient_status(struct dm_exception_store *store,
88 status_type_t status, char *result,
89 unsigned maxlen)
90{
91 unsigned sz = 0;
92
93 switch (status) {
94 case STATUSTYPE_INFO:
95 break;
96 case STATUSTYPE_TABLE:
97 DMEMIT(" N %llu", (unsigned long long)store->chunk_size);
98 break;
99 case STATUSTYPE_IMA:
100 *result = '\0';
101 break;
102 }
103
104 return sz;
105}
106
107static struct dm_exception_store_type _transient_type = {
108 .name = "transient",
109 .module = THIS_MODULE,
110 .ctr = transient_ctr,
111 .dtr = transient_dtr,
112 .read_metadata = transient_read_metadata,
113 .prepare_exception = transient_prepare_exception,
114 .commit_exception = transient_commit_exception,
115 .usage = transient_usage,
116 .status = transient_status,
117};
118
119static struct dm_exception_store_type _transient_compat_type = {
120 .name = "N",
121 .module = THIS_MODULE,
122 .ctr = transient_ctr,
123 .dtr = transient_dtr,
124 .read_metadata = transient_read_metadata,
125 .prepare_exception = transient_prepare_exception,
126 .commit_exception = transient_commit_exception,
127 .usage = transient_usage,
128 .status = transient_status,
129};
130
131int dm_transient_snapshot_init(void)
132{
133 int r;
134
135 r = dm_exception_store_type_register(&_transient_type);
136 if (r) {
137 DMWARN("Unable to register transient exception store type");
138 return r;
139 }
140
141 r = dm_exception_store_type_register(&_transient_compat_type);
142 if (r) {
143 DMWARN("Unable to register old-style transient "
144 "exception store type");
145 dm_exception_store_type_unregister(&_transient_type);
146 return r;
147 }
148
149 return r;
150}
151
152void dm_transient_snapshot_exit(void)
153{
154 dm_exception_store_type_unregister(&_transient_type);
155 dm_exception_store_type_unregister(&_transient_compat_type);
156}