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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm.h"
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/blkdev.h>
12#include <linux/bio.h>
13#include <linux/dax.h>
14#include <linux/slab.h>
15#include <linux/device-mapper.h>
16
17#define DM_MSG_PREFIX "linear"
18
19/*
20 * Linear: maps a linear range of a device.
21 */
22struct linear_c {
23 struct dm_dev *dev;
24 sector_t start;
25};
26
27/*
28 * Construct a linear mapping: <dev_path> <offset>
29 */
30static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
31{
32 struct linear_c *lc;
33 unsigned long long tmp;
34 char dummy;
35 int ret;
36
37 if (argc != 2) {
38 ti->error = "Invalid argument count";
39 return -EINVAL;
40 }
41
42 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
43 if (lc == NULL) {
44 ti->error = "Cannot allocate linear context";
45 return -ENOMEM;
46 }
47
48 ret = -EINVAL;
49 if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
50 ti->error = "Invalid device sector";
51 goto bad;
52 }
53 lc->start = tmp;
54
55 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
56 if (ret) {
57 ti->error = "Device lookup failed";
58 goto bad;
59 }
60
61 ti->num_flush_bios = 1;
62 ti->num_discard_bios = 1;
63 ti->num_secure_erase_bios = 1;
64 ti->num_write_zeroes_bios = 1;
65 ti->flush_bypasses_map = true;
66 ti->private = lc;
67 return 0;
68
69bad:
70 kfree(lc);
71 return ret;
72}
73
74static void linear_dtr(struct dm_target *ti)
75{
76 struct linear_c *lc = ti->private;
77
78 dm_put_device(ti, lc->dev);
79 kfree(lc);
80}
81
82static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
83{
84 struct linear_c *lc = ti->private;
85
86 return lc->start + dm_target_offset(ti, bi_sector);
87}
88
89int linear_map(struct dm_target *ti, struct bio *bio)
90{
91 struct linear_c *lc = ti->private;
92
93 bio_set_dev(bio, lc->dev->bdev);
94 bio->bi_iter.bi_sector = linear_map_sector(ti, bio->bi_iter.bi_sector);
95
96 return DM_MAPIO_REMAPPED;
97}
98
99static void linear_status(struct dm_target *ti, status_type_t type,
100 unsigned int status_flags, char *result, unsigned int maxlen)
101{
102 struct linear_c *lc = ti->private;
103 size_t sz = 0;
104
105 switch (type) {
106 case STATUSTYPE_INFO:
107 result[0] = '\0';
108 break;
109
110 case STATUSTYPE_TABLE:
111 DMEMIT("%s %llu", lc->dev->name, (unsigned long long)lc->start);
112 break;
113
114 case STATUSTYPE_IMA:
115 DMEMIT_TARGET_NAME_VERSION(ti->type);
116 DMEMIT(",device_name=%s,start=%llu;", lc->dev->name,
117 (unsigned long long)lc->start);
118 break;
119 }
120}
121
122static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
123{
124 struct linear_c *lc = ti->private;
125 struct dm_dev *dev = lc->dev;
126
127 *bdev = dev->bdev;
128
129 /*
130 * Only pass ioctls through if the device sizes match exactly.
131 */
132 if (lc->start || ti->len != bdev_nr_sectors(dev->bdev))
133 return 1;
134 return 0;
135}
136
137#ifdef CONFIG_BLK_DEV_ZONED
138static int linear_report_zones(struct dm_target *ti,
139 struct dm_report_zones_args *args, unsigned int nr_zones)
140{
141 struct linear_c *lc = ti->private;
142
143 return dm_report_zones(lc->dev->bdev, lc->start,
144 linear_map_sector(ti, args->next_sector),
145 args, nr_zones);
146}
147#else
148#define linear_report_zones NULL
149#endif
150
151static int linear_iterate_devices(struct dm_target *ti,
152 iterate_devices_callout_fn fn, void *data)
153{
154 struct linear_c *lc = ti->private;
155
156 return fn(ti, lc->dev, lc->start, ti->len, data);
157}
158
159#if IS_ENABLED(CONFIG_FS_DAX)
160static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
161{
162 struct linear_c *lc = ti->private;
163 sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
164
165 *pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT;
166 return lc->dev->dax_dev;
167}
168
169static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
170 long nr_pages, enum dax_access_mode mode, void **kaddr,
171 pfn_t *pfn)
172{
173 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
174
175 return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
176}
177
178static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
179 size_t nr_pages)
180{
181 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
182
183 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
184}
185
186static size_t linear_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
187 void *addr, size_t bytes, struct iov_iter *i)
188{
189 struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
190
191 return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
192}
193
194#else
195#define linear_dax_direct_access NULL
196#define linear_dax_zero_page_range NULL
197#define linear_dax_recovery_write NULL
198#endif
199
200static struct target_type linear_target = {
201 .name = "linear",
202 .version = {1, 4, 0},
203 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
204 DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
205 .report_zones = linear_report_zones,
206 .module = THIS_MODULE,
207 .ctr = linear_ctr,
208 .dtr = linear_dtr,
209 .map = linear_map,
210 .status = linear_status,
211 .prepare_ioctl = linear_prepare_ioctl,
212 .iterate_devices = linear_iterate_devices,
213 .direct_access = linear_dax_direct_access,
214 .dax_zero_page_range = linear_dax_zero_page_range,
215 .dax_recovery_write = linear_dax_recovery_write,
216};
217
218int __init dm_linear_init(void)
219{
220 int r = dm_register_target(&linear_target);
221
222 if (r < 0)
223 DMERR("register failed %d", r);
224
225 return r;
226}
227
228void dm_linear_exit(void)
229{
230 dm_unregister_target(&linear_target);
231}
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) {
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_same_bios = 1;
64 ti->num_write_zeroes_bios = 1;
65 ti->private = lc;
66 return 0;
67
68 bad:
69 kfree(lc);
70 return ret;
71}
72
73static void linear_dtr(struct dm_target *ti)
74{
75 struct linear_c *lc = (struct linear_c *) ti->private;
76
77 dm_put_device(ti, lc->dev);
78 kfree(lc);
79}
80
81static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
82{
83 struct linear_c *lc = ti->private;
84
85 return lc->start + dm_target_offset(ti, bi_sector);
86}
87
88static void linear_map_bio(struct dm_target *ti, struct bio *bio)
89{
90 struct linear_c *lc = ti->private;
91
92 bio_set_dev(bio, lc->dev->bdev);
93 if (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET)
94 bio->bi_iter.bi_sector =
95 linear_map_sector(ti, bio->bi_iter.bi_sector);
96}
97
98static int linear_map(struct dm_target *ti, struct bio *bio)
99{
100 linear_map_bio(ti, bio);
101
102 return DM_MAPIO_REMAPPED;
103}
104
105static int linear_end_io(struct dm_target *ti, struct bio *bio,
106 blk_status_t *error)
107{
108 struct linear_c *lc = ti->private;
109
110 if (!*error && bio_op(bio) == REQ_OP_ZONE_REPORT)
111 dm_remap_zone_report(ti, bio, lc->start);
112
113 return DM_ENDIO_DONE;
114}
115
116static void linear_status(struct dm_target *ti, status_type_t type,
117 unsigned status_flags, char *result, unsigned maxlen)
118{
119 struct linear_c *lc = (struct linear_c *) ti->private;
120
121 switch (type) {
122 case STATUSTYPE_INFO:
123 result[0] = '\0';
124 break;
125
126 case STATUSTYPE_TABLE:
127 snprintf(result, maxlen, "%s %llu", lc->dev->name,
128 (unsigned long long)lc->start);
129 break;
130 }
131}
132
133static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
134{
135 struct linear_c *lc = (struct linear_c *) ti->private;
136 struct dm_dev *dev = lc->dev;
137
138 *bdev = dev->bdev;
139
140 /*
141 * Only pass ioctls through if the device sizes match exactly.
142 */
143 if (lc->start ||
144 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
145 return 1;
146 return 0;
147}
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_DAX_DRIVER)
158static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
159 long nr_pages, void **kaddr, pfn_t *pfn)
160{
161 long ret;
162 struct linear_c *lc = ti->private;
163 struct block_device *bdev = lc->dev->bdev;
164 struct dax_device *dax_dev = lc->dev->dax_dev;
165 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
166
167 dev_sector = linear_map_sector(ti, sector);
168 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
169 if (ret)
170 return ret;
171 return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
172}
173
174static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
175 void *addr, size_t bytes, struct iov_iter *i)
176{
177 struct linear_c *lc = ti->private;
178 struct block_device *bdev = lc->dev->bdev;
179 struct dax_device *dax_dev = lc->dev->dax_dev;
180 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
181
182 dev_sector = linear_map_sector(ti, sector);
183 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
184 return 0;
185 return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
186}
187
188#else
189#define linear_dax_direct_access NULL
190#define linear_dax_copy_from_iter NULL
191#endif
192
193static struct target_type linear_target = {
194 .name = "linear",
195 .version = {1, 4, 0},
196 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM,
197 .module = THIS_MODULE,
198 .ctr = linear_ctr,
199 .dtr = linear_dtr,
200 .map = linear_map,
201 .end_io = linear_end_io,
202 .status = linear_status,
203 .prepare_ioctl = linear_prepare_ioctl,
204 .iterate_devices = linear_iterate_devices,
205 .direct_access = linear_dax_direct_access,
206 .dax_copy_from_iter = linear_dax_copy_from_iter,
207};
208
209int __init dm_linear_init(void)
210{
211 int r = dm_register_target(&linear_target);
212
213 if (r < 0)
214 DMERR("register failed %d", r);
215
216 return r;
217}
218
219void dm_linear_exit(void)
220{
221 dm_unregister_target(&linear_target);
222}