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