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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 || 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_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) || op_is_zone_mgmt(bio_op(bio)))
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 void linear_status(struct dm_target *ti, status_type_t type,
106 unsigned status_flags, char *result, unsigned maxlen)
107{
108 struct linear_c *lc = (struct linear_c *) ti->private;
109
110 switch (type) {
111 case STATUSTYPE_INFO:
112 result[0] = '\0';
113 break;
114
115 case STATUSTYPE_TABLE:
116 snprintf(result, maxlen, "%s %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 = (struct linear_c *) 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 ||
133 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
134 return 1;
135 return 0;
136}
137
138#ifdef CONFIG_BLK_DEV_ZONED
139static int linear_report_zones(struct dm_target *ti,
140 struct dm_report_zones_args *args, unsigned int nr_zones)
141{
142 struct linear_c *lc = ti->private;
143 sector_t sector = linear_map_sector(ti, args->next_sector);
144
145 args->start = lc->start;
146 return blkdev_report_zones(lc->dev->bdev, sector, nr_zones,
147 dm_report_zones_cb, args);
148}
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_DAX_DRIVER)
160static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
161 long nr_pages, void **kaddr, pfn_t *pfn)
162{
163 long ret;
164 struct linear_c *lc = ti->private;
165 struct block_device *bdev = lc->dev->bdev;
166 struct dax_device *dax_dev = lc->dev->dax_dev;
167 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
168
169 dev_sector = linear_map_sector(ti, sector);
170 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
171 if (ret)
172 return ret;
173 return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
174}
175
176static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
177 void *addr, size_t bytes, struct iov_iter *i)
178{
179 struct linear_c *lc = ti->private;
180 struct block_device *bdev = lc->dev->bdev;
181 struct dax_device *dax_dev = lc->dev->dax_dev;
182 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
183
184 dev_sector = linear_map_sector(ti, sector);
185 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
186 return 0;
187 return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
188}
189
190static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
191 void *addr, size_t bytes, struct iov_iter *i)
192{
193 struct linear_c *lc = ti->private;
194 struct block_device *bdev = lc->dev->bdev;
195 struct dax_device *dax_dev = lc->dev->dax_dev;
196 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
197
198 dev_sector = linear_map_sector(ti, sector);
199 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
200 return 0;
201 return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
202}
203
204static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
205 size_t nr_pages)
206{
207 int ret;
208 struct linear_c *lc = ti->private;
209 struct block_device *bdev = lc->dev->bdev;
210 struct dax_device *dax_dev = lc->dev->dax_dev;
211 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
212
213 dev_sector = linear_map_sector(ti, sector);
214 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
215 if (ret)
216 return ret;
217 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
218}
219
220#else
221#define linear_dax_direct_access NULL
222#define linear_dax_copy_from_iter NULL
223#define linear_dax_copy_to_iter NULL
224#define linear_dax_zero_page_range NULL
225#endif
226
227static struct target_type linear_target = {
228 .name = "linear",
229 .version = {1, 4, 0},
230#ifdef CONFIG_BLK_DEV_ZONED
231 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM,
232 .report_zones = linear_report_zones,
233#else
234 .features = DM_TARGET_PASSES_INTEGRITY,
235#endif
236 .module = THIS_MODULE,
237 .ctr = linear_ctr,
238 .dtr = linear_dtr,
239 .map = linear_map,
240 .status = linear_status,
241 .prepare_ioctl = linear_prepare_ioctl,
242 .iterate_devices = linear_iterate_devices,
243 .direct_access = linear_dax_direct_access,
244 .dax_copy_from_iter = linear_dax_copy_from_iter,
245 .dax_copy_to_iter = linear_dax_copy_to_iter,
246 .dax_zero_page_range = linear_dax_zero_page_range,
247};
248
249int __init dm_linear_init(void)
250{
251 int r = dm_register_target(&linear_target);
252
253 if (r < 0)
254 DMERR("register failed %d", r);
255
256 return r;
257}
258
259void dm_linear_exit(void)
260{
261 dm_unregister_target(&linear_target);
262}