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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/*
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}