This source file includes following definitions.
- linear_ctr
- linear_dtr
- linear_map_sector
- linear_map_bio
- linear_map
- linear_status
- linear_prepare_ioctl
- linear_report_zones
- linear_iterate_devices
- linear_dax_direct_access
- linear_dax_copy_from_iter
- linear_dax_copy_to_iter
- dm_linear_init
- dm_linear_exit
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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
20
21 struct linear_c {
22 struct dm_dev *dev;
23 sector_t start;
24 };
25
26
27
28
29 static 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
73 static 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
81 static 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
88 static 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
98 static 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
105 static 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
122 static 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
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
139 static int linear_report_zones(struct dm_target *ti, sector_t sector,
140 struct blk_zone *zones, unsigned int *nr_zones)
141 {
142 struct linear_c *lc = (struct linear_c *) ti->private;
143 int ret;
144
145
146 ret = blkdev_report_zones(lc->dev->bdev, linear_map_sector(ti, sector),
147 zones, nr_zones);
148 if (ret != 0)
149 return ret;
150
151 if (*nr_zones)
152 dm_remap_zone_report(ti, lc->start, zones, nr_zones);
153 return 0;
154 }
155 #endif
156
157 static int linear_iterate_devices(struct dm_target *ti,
158 iterate_devices_callout_fn fn, void *data)
159 {
160 struct linear_c *lc = ti->private;
161
162 return fn(ti, lc->dev, lc->start, ti->len, data);
163 }
164
165 #if IS_ENABLED(CONFIG_DAX_DRIVER)
166 static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
167 long nr_pages, void **kaddr, pfn_t *pfn)
168 {
169 long ret;
170 struct linear_c *lc = ti->private;
171 struct block_device *bdev = lc->dev->bdev;
172 struct dax_device *dax_dev = lc->dev->dax_dev;
173 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
174
175 dev_sector = linear_map_sector(ti, sector);
176 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
177 if (ret)
178 return ret;
179 return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
180 }
181
182 static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
183 void *addr, size_t bytes, struct iov_iter *i)
184 {
185 struct linear_c *lc = ti->private;
186 struct block_device *bdev = lc->dev->bdev;
187 struct dax_device *dax_dev = lc->dev->dax_dev;
188 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
189
190 dev_sector = linear_map_sector(ti, sector);
191 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
192 return 0;
193 return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
194 }
195
196 static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
197 void *addr, size_t bytes, struct iov_iter *i)
198 {
199 struct linear_c *lc = ti->private;
200 struct block_device *bdev = lc->dev->bdev;
201 struct dax_device *dax_dev = lc->dev->dax_dev;
202 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
203
204 dev_sector = linear_map_sector(ti, sector);
205 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
206 return 0;
207 return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
208 }
209
210 #else
211 #define linear_dax_direct_access NULL
212 #define linear_dax_copy_from_iter NULL
213 #define linear_dax_copy_to_iter NULL
214 #endif
215
216 static struct target_type linear_target = {
217 .name = "linear",
218 .version = {1, 4, 0},
219 #ifdef CONFIG_BLK_DEV_ZONED
220 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM,
221 .report_zones = linear_report_zones,
222 #else
223 .features = DM_TARGET_PASSES_INTEGRITY,
224 #endif
225 .module = THIS_MODULE,
226 .ctr = linear_ctr,
227 .dtr = linear_dtr,
228 .map = linear_map,
229 .status = linear_status,
230 .prepare_ioctl = linear_prepare_ioctl,
231 .iterate_devices = linear_iterate_devices,
232 .direct_access = linear_dax_direct_access,
233 .dax_copy_from_iter = linear_dax_copy_from_iter,
234 .dax_copy_to_iter = linear_dax_copy_to_iter,
235 };
236
237 int __init dm_linear_init(void)
238 {
239 int r = dm_register_target(&linear_target);
240
241 if (r < 0)
242 DMERR("register failed %d", r);
243
244 return r;
245 }
246
247 void dm_linear_exit(void)
248 {
249 dm_unregister_target(&linear_target);
250 }