Commit | Line | Data |
---|---|---|
1da177e4 LT |
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" | |
1da177e4 LT |
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> | |
586e80e6 | 13 | #include <linux/device-mapper.h> |
1da177e4 | 14 | |
72d94861 AK |
15 | #define DM_MSG_PREFIX "linear" |
16 | ||
1da177e4 LT |
17 | /* |
18 | * Linear: maps a linear range of a device. | |
19 | */ | |
20 | struct linear_c { | |
21 | struct dm_dev *dev; | |
22 | sector_t start; | |
23 | }; | |
24 | ||
25 | /* | |
26 | * Construct a linear mapping: <dev_path> <offset> | |
27 | */ | |
28 | static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
29 | { | |
30 | struct linear_c *lc; | |
4ee218cd | 31 | unsigned long long tmp; |
31998ef1 | 32 | char dummy; |
e80d1c80 | 33 | int ret; |
1da177e4 LT |
34 | |
35 | if (argc != 2) { | |
72d94861 | 36 | ti->error = "Invalid argument count"; |
1da177e4 LT |
37 | return -EINVAL; |
38 | } | |
39 | ||
40 | lc = kmalloc(sizeof(*lc), GFP_KERNEL); | |
41 | if (lc == NULL) { | |
00272c85 | 42 | ti->error = "Cannot allocate linear context"; |
1da177e4 LT |
43 | return -ENOMEM; |
44 | } | |
45 | ||
e80d1c80 | 46 | ret = -EINVAL; |
31998ef1 | 47 | if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) { |
00272c85 | 48 | ti->error = "Invalid device sector"; |
1da177e4 LT |
49 | goto bad; |
50 | } | |
4ee218cd | 51 | lc->start = tmp; |
1da177e4 | 52 | |
e80d1c80 VG |
53 | ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev); |
54 | if (ret) { | |
00272c85 | 55 | ti->error = "Device lookup failed"; |
1da177e4 LT |
56 | goto bad; |
57 | } | |
58 | ||
55a62eef AK |
59 | ti->num_flush_bios = 1; |
60 | ti->num_discard_bios = 1; | |
61 | ti->num_write_same_bios = 1; | |
1da177e4 LT |
62 | ti->private = lc; |
63 | return 0; | |
64 | ||
65 | bad: | |
66 | kfree(lc); | |
e80d1c80 | 67 | return ret; |
1da177e4 LT |
68 | } |
69 | ||
70 | static 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 | ||
7bc3447b | 78 | static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector) |
1da177e4 | 79 | { |
7bc3447b MB |
80 | struct linear_c *lc = ti->private; |
81 | ||
b441a262 | 82 | return lc->start + dm_target_offset(ti, bi_sector); |
7bc3447b MB |
83 | } |
84 | ||
85 | static void linear_map_bio(struct dm_target *ti, struct bio *bio) | |
86 | { | |
87 | struct linear_c *lc = ti->private; | |
1da177e4 LT |
88 | |
89 | bio->bi_bdev = lc->dev->bdev; | |
433bcac5 | 90 | if (bio_sectors(bio)) |
4f024f37 KO |
91 | bio->bi_iter.bi_sector = |
92 | linear_map_sector(ti, bio->bi_iter.bi_sector); | |
7bc3447b MB |
93 | } |
94 | ||
7de3ee57 | 95 | static int linear_map(struct dm_target *ti, struct bio *bio) |
7bc3447b MB |
96 | { |
97 | linear_map_bio(ti, bio); | |
1da177e4 | 98 | |
d2a7ad29 | 99 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
100 | } |
101 | ||
fd7c092e MP |
102 | static void linear_status(struct dm_target *ti, status_type_t type, |
103 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
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: | |
4ee218cd AM |
113 | snprintf(result, maxlen, "%s %llu", lc->dev->name, |
114 | (unsigned long long)lc->start); | |
1da177e4 LT |
115 | break; |
116 | } | |
1da177e4 LT |
117 | } |
118 | ||
e56f81e0 CH |
119 | static int linear_prepare_ioctl(struct dm_target *ti, |
120 | struct block_device **bdev, fmode_t *mode) | |
ab17ffa4 MB |
121 | { |
122 | struct linear_c *lc = (struct linear_c *) ti->private; | |
ec8013be | 123 | struct dm_dev *dev = lc->dev; |
e56f81e0 CH |
124 | |
125 | *bdev = dev->bdev; | |
ec8013be PB |
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) | |
e56f81e0 CH |
132 | return 1; |
133 | return 0; | |
ab17ffa4 MB |
134 | } |
135 | ||
af4874e0 MS |
136 | static 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 | ||
5dea271b | 141 | return fn(ti, lc->dev, lc->start, ti->len, data); |
af4874e0 MS |
142 | } |
143 | ||
1da177e4 LT |
144 | static struct target_type linear_target = { |
145 | .name = "linear", | |
fd7c092e | 146 | .version = {1, 2, 1}, |
1da177e4 LT |
147 | .module = THIS_MODULE, |
148 | .ctr = linear_ctr, | |
149 | .dtr = linear_dtr, | |
150 | .map = linear_map, | |
151 | .status = linear_status, | |
e56f81e0 | 152 | .prepare_ioctl = linear_prepare_ioctl, |
af4874e0 | 153 | .iterate_devices = linear_iterate_devices, |
1da177e4 LT |
154 | }; |
155 | ||
156 | int __init dm_linear_init(void) | |
157 | { | |
158 | int r = dm_register_target(&linear_target); | |
159 | ||
160 | if (r < 0) | |
72d94861 | 161 | DMERR("register failed %d", r); |
1da177e4 LT |
162 | |
163 | return r; | |
164 | } | |
165 | ||
166 | void dm_linear_exit(void) | |
167 | { | |
10d3bd09 | 168 | dm_unregister_target(&linear_target); |
1da177e4 | 169 | } |