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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 char dummy;
33
34 if (argc != 2) {
35 ti->error = "Invalid argument count";
36 return -EINVAL;
37 }
38
39 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
40 if (lc == NULL) {
41 ti->error = "dm-linear: Cannot allocate linear context";
42 return -ENOMEM;
43 }
44
45 if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
46 ti->error = "dm-linear: Invalid device sector";
47 goto bad;
48 }
49 lc->start = tmp;
50
51 if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
52 ti->error = "dm-linear: Device lookup failed";
53 goto bad;
54 }
55
56 ti->num_flush_requests = 1;
57 ti->num_discard_requests = 1;
58 ti->private = lc;
59 return 0;
60
61 bad:
62 kfree(lc);
63 return -EINVAL;
64}
65
66static void linear_dtr(struct dm_target *ti)
67{
68 struct linear_c *lc = (struct linear_c *) ti->private;
69
70 dm_put_device(ti, lc->dev);
71 kfree(lc);
72}
73
74static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
75{
76 struct linear_c *lc = ti->private;
77
78 return lc->start + dm_target_offset(ti, bi_sector);
79}
80
81static void linear_map_bio(struct dm_target *ti, struct bio *bio)
82{
83 struct linear_c *lc = ti->private;
84
85 bio->bi_bdev = lc->dev->bdev;
86 if (bio_sectors(bio))
87 bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
88}
89
90static int linear_map(struct dm_target *ti, struct bio *bio,
91 union map_info *map_context)
92{
93 linear_map_bio(ti, bio);
94
95 return DM_MAPIO_REMAPPED;
96}
97
98static int linear_status(struct dm_target *ti, status_type_t type,
99 char *result, unsigned int maxlen)
100{
101 struct linear_c *lc = (struct linear_c *) ti->private;
102
103 switch (type) {
104 case STATUSTYPE_INFO:
105 result[0] = '\0';
106 break;
107
108 case STATUSTYPE_TABLE:
109 snprintf(result, maxlen, "%s %llu", lc->dev->name,
110 (unsigned long long)lc->start);
111 break;
112 }
113 return 0;
114}
115
116static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
117 unsigned long arg)
118{
119 struct linear_c *lc = (struct linear_c *) ti->private;
120 struct dm_dev *dev = lc->dev;
121 int r = 0;
122
123 /*
124 * Only pass ioctls through if the device sizes match exactly.
125 */
126 if (lc->start ||
127 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
128 r = scsi_verify_blk_ioctl(NULL, cmd);
129
130 return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
131}
132
133static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
134 struct bio_vec *biovec, int max_size)
135{
136 struct linear_c *lc = ti->private;
137 struct request_queue *q = bdev_get_queue(lc->dev->bdev);
138
139 if (!q->merge_bvec_fn)
140 return max_size;
141
142 bvm->bi_bdev = lc->dev->bdev;
143 bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector);
144
145 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
146}
147
148static int linear_iterate_devices(struct dm_target *ti,
149 iterate_devices_callout_fn fn, void *data)
150{
151 struct linear_c *lc = ti->private;
152
153 return fn(ti, lc->dev, lc->start, ti->len, data);
154}
155
156static struct target_type linear_target = {
157 .name = "linear",
158 .version = {1, 1, 0},
159 .module = THIS_MODULE,
160 .ctr = linear_ctr,
161 .dtr = linear_dtr,
162 .map = linear_map,
163 .status = linear_status,
164 .ioctl = linear_ioctl,
165 .merge = linear_merge,
166 .iterate_devices = linear_iterate_devices,
167};
168
169int __init dm_linear_init(void)
170{
171 int r = dm_register_target(&linear_target);
172
173 if (r < 0)
174 DMERR("register failed %d", r);
175
176 return r;
177}
178
179void dm_linear_exit(void)
180{
181 dm_unregister_target(&linear_target);
182}
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}