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1/*
2 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm.h"
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/blkdev.h>
11#include <linux/bio.h>
12#include <linux/slab.h>
13#include <linux/device-mapper.h>
14
15#define DM_MSG_PREFIX "linear"
16
17/*
18 * Linear: maps a linear range of a device.
19 */
20struct linear_c {
21 struct dm_dev *dev;
22 sector_t start;
23};
24
25/*
26 * Construct a linear mapping: <dev_path> <offset>
27 */
28static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
29{
30 struct linear_c *lc;
31 unsigned long long tmp;
32
33 if (argc != 2) {
34 ti->error = "Invalid argument count";
35 return -EINVAL;
36 }
37
38 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
39 if (lc == NULL) {
40 ti->error = "dm-linear: Cannot allocate linear context";
41 return -ENOMEM;
42 }
43
44 if (sscanf(argv[1], "%llu", &tmp) != 1) {
45 ti->error = "dm-linear: Invalid device sector";
46 goto bad;
47 }
48 lc->start = tmp;
49
50 if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
51 ti->error = "dm-linear: Device lookup failed";
52 goto bad;
53 }
54
55 ti->num_flush_requests = 1;
56 ti->num_discard_requests = 1;
57 ti->private = lc;
58 return 0;
59
60 bad:
61 kfree(lc);
62 return -EINVAL;
63}
64
65static void linear_dtr(struct dm_target *ti)
66{
67 struct linear_c *lc = (struct linear_c *) ti->private;
68
69 dm_put_device(ti, lc->dev);
70 kfree(lc);
71}
72
73static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
74{
75 struct linear_c *lc = ti->private;
76
77 return lc->start + dm_target_offset(ti, bi_sector);
78}
79
80static void linear_map_bio(struct dm_target *ti, struct bio *bio)
81{
82 struct linear_c *lc = ti->private;
83
84 bio->bi_bdev = lc->dev->bdev;
85 if (bio_sectors(bio))
86 bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
87}
88
89static int linear_map(struct dm_target *ti, struct bio *bio,
90 union map_info *map_context)
91{
92 linear_map_bio(ti, bio);
93
94 return DM_MAPIO_REMAPPED;
95}
96
97static int linear_status(struct dm_target *ti, status_type_t type,
98 char *result, unsigned int maxlen)
99{
100 struct linear_c *lc = (struct linear_c *) ti->private;
101
102 switch (type) {
103 case STATUSTYPE_INFO:
104 result[0] = '\0';
105 break;
106
107 case STATUSTYPE_TABLE:
108 snprintf(result, maxlen, "%s %llu", lc->dev->name,
109 (unsigned long long)lc->start);
110 break;
111 }
112 return 0;
113}
114
115static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
116 unsigned long arg)
117{
118 struct linear_c *lc = (struct linear_c *) ti->private;
119 return __blkdev_driver_ioctl(lc->dev->bdev, lc->dev->mode, cmd, arg);
120}
121
122static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
123 struct bio_vec *biovec, int max_size)
124{
125 struct linear_c *lc = ti->private;
126 struct request_queue *q = bdev_get_queue(lc->dev->bdev);
127
128 if (!q->merge_bvec_fn)
129 return max_size;
130
131 bvm->bi_bdev = lc->dev->bdev;
132 bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector);
133
134 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
135}
136
137static int linear_iterate_devices(struct dm_target *ti,
138 iterate_devices_callout_fn fn, void *data)
139{
140 struct linear_c *lc = ti->private;
141
142 return fn(ti, lc->dev, lc->start, ti->len, data);
143}
144
145static struct target_type linear_target = {
146 .name = "linear",
147 .version = {1, 1, 0},
148 .module = THIS_MODULE,
149 .ctr = linear_ctr,
150 .dtr = linear_dtr,
151 .map = linear_map,
152 .status = linear_status,
153 .ioctl = linear_ioctl,
154 .merge = linear_merge,
155 .iterate_devices = linear_iterate_devices,
156};
157
158int __init dm_linear_init(void)
159{
160 int r = dm_register_target(&linear_target);
161
162 if (r < 0)
163 DMERR("register failed %d", r);
164
165 return r;
166}
167
168void dm_linear_exit(void)
169{
170 dm_unregister_target(&linear_target);
171}
1/*
2 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm.h"
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/blkdev.h>
11#include <linux/bio.h>
12#include <linux/dax.h>
13#include <linux/slab.h>
14#include <linux/device-mapper.h>
15
16#define DM_MSG_PREFIX "linear"
17
18/*
19 * Linear: maps a linear range of a device.
20 */
21struct linear_c {
22 struct dm_dev *dev;
23 sector_t start;
24};
25
26/*
27 * Construct a linear mapping: <dev_path> <offset>
28 */
29static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
30{
31 struct linear_c *lc;
32 unsigned long long tmp;
33 char dummy;
34 int ret;
35
36 if (argc != 2) {
37 ti->error = "Invalid argument count";
38 return -EINVAL;
39 }
40
41 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
42 if (lc == NULL) {
43 ti->error = "Cannot allocate linear context";
44 return -ENOMEM;
45 }
46
47 ret = -EINVAL;
48 if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
49 ti->error = "Invalid device sector";
50 goto bad;
51 }
52 lc->start = tmp;
53
54 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
55 if (ret) {
56 ti->error = "Device lookup failed";
57 goto bad;
58 }
59
60 ti->num_flush_bios = 1;
61 ti->num_discard_bios = 1;
62 ti->num_secure_erase_bios = 1;
63 ti->num_write_zeroes_bios = 1;
64 ti->private = lc;
65 return 0;
66
67 bad:
68 kfree(lc);
69 return ret;
70}
71
72static void linear_dtr(struct dm_target *ti)
73{
74 struct linear_c *lc = (struct linear_c *) ti->private;
75
76 dm_put_device(ti, lc->dev);
77 kfree(lc);
78}
79
80static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
81{
82 struct linear_c *lc = ti->private;
83
84 return lc->start + dm_target_offset(ti, bi_sector);
85}
86
87static int linear_map(struct dm_target *ti, struct bio *bio)
88{
89 struct linear_c *lc = ti->private;
90
91 bio_set_dev(bio, lc->dev->bdev);
92 bio->bi_iter.bi_sector = linear_map_sector(ti, bio->bi_iter.bi_sector);
93
94 return DM_MAPIO_REMAPPED;
95}
96
97static void linear_status(struct dm_target *ti, status_type_t type,
98 unsigned status_flags, char *result, unsigned maxlen)
99{
100 struct linear_c *lc = (struct linear_c *) ti->private;
101 size_t sz = 0;
102
103 switch (type) {
104 case STATUSTYPE_INFO:
105 result[0] = '\0';
106 break;
107
108 case STATUSTYPE_TABLE:
109 DMEMIT("%s %llu", lc->dev->name, (unsigned long long)lc->start);
110 break;
111
112 case STATUSTYPE_IMA:
113 DMEMIT_TARGET_NAME_VERSION(ti->type);
114 DMEMIT(",device_name=%s,start=%llu;", lc->dev->name,
115 (unsigned long long)lc->start);
116 break;
117 }
118}
119
120static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
121{
122 struct linear_c *lc = (struct linear_c *) ti->private;
123 struct dm_dev *dev = lc->dev;
124
125 *bdev = dev->bdev;
126
127 /*
128 * Only pass ioctls through if the device sizes match exactly.
129 */
130 if (lc->start || ti->len != bdev_nr_sectors(dev->bdev))
131 return 1;
132 return 0;
133}
134
135#ifdef CONFIG_BLK_DEV_ZONED
136static int linear_report_zones(struct dm_target *ti,
137 struct dm_report_zones_args *args, unsigned int nr_zones)
138{
139 struct linear_c *lc = ti->private;
140
141 return dm_report_zones(lc->dev->bdev, lc->start,
142 linear_map_sector(ti, args->next_sector),
143 args, nr_zones);
144}
145#else
146#define linear_report_zones NULL
147#endif
148
149static int linear_iterate_devices(struct dm_target *ti,
150 iterate_devices_callout_fn fn, void *data)
151{
152 struct linear_c *lc = ti->private;
153
154 return fn(ti, lc->dev, lc->start, ti->len, data);
155}
156
157#if IS_ENABLED(CONFIG_FS_DAX)
158static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
159{
160 struct linear_c *lc = ti->private;
161 sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
162
163 *pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT;
164 return lc->dev->dax_dev;
165}
166
167static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
168 long nr_pages, enum dax_access_mode mode, void **kaddr,
169 pfn_t *pfn)
170{
171 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
172
173 return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
174}
175
176static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
177 size_t nr_pages)
178{
179 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
180
181 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
182}
183
184static size_t linear_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
185 void *addr, size_t bytes, struct iov_iter *i)
186{
187 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
188
189 return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
190}
191
192#else
193#define linear_dax_direct_access NULL
194#define linear_dax_zero_page_range NULL
195#define linear_dax_recovery_write NULL
196#endif
197
198static struct target_type linear_target = {
199 .name = "linear",
200 .version = {1, 4, 0},
201 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
202 DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
203 .report_zones = linear_report_zones,
204 .module = THIS_MODULE,
205 .ctr = linear_ctr,
206 .dtr = linear_dtr,
207 .map = linear_map,
208 .status = linear_status,
209 .prepare_ioctl = linear_prepare_ioctl,
210 .iterate_devices = linear_iterate_devices,
211 .direct_access = linear_dax_direct_access,
212 .dax_zero_page_range = linear_dax_zero_page_range,
213 .dax_recovery_write = linear_dax_recovery_write,
214};
215
216int __init dm_linear_init(void)
217{
218 int r = dm_register_target(&linear_target);
219
220 if (r < 0)
221 DMERR("register failed %d", r);
222
223 return r;
224}
225
226void dm_linear_exit(void)
227{
228 dm_unregister_target(&linear_target);
229}