2 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
4 * This file is released under the GPL.
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>
15 #define DM_MSG_PREFIX "linear"
18 * Linear: maps a linear range of a device.
26 * Construct a linear mapping: <dev_path> <offset>
28 int dm_linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
31 unsigned long long tmp;
36 ti->error = "Invalid argument count";
40 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
42 ti->error = "Cannot allocate linear context";
47 if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
48 ti->error = "Invalid device sector";
53 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
55 ti->error = "Device lookup failed";
59 ti->num_flush_bios = 1;
60 ti->num_discard_bios = 1;
61 ti->num_write_same_bios = 1;
69 EXPORT_SYMBOL_GPL(dm_linear_ctr);
71 void dm_linear_dtr(struct dm_target *ti)
73 struct linear_c *lc = (struct linear_c *) ti->private;
75 dm_put_device(ti, lc->dev);
78 EXPORT_SYMBOL_GPL(dm_linear_dtr);
80 static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
82 struct linear_c *lc = ti->private;
84 return lc->start + dm_target_offset(ti, bi_sector);
87 static void linear_map_bio(struct dm_target *ti, struct bio *bio)
89 struct linear_c *lc = ti->private;
91 bio->bi_bdev = lc->dev->bdev;
93 bio->bi_iter.bi_sector =
94 linear_map_sector(ti, bio->bi_iter.bi_sector);
97 int dm_linear_map(struct dm_target *ti, struct bio *bio)
99 linear_map_bio(ti, bio);
101 return DM_MAPIO_REMAPPED;
103 EXPORT_SYMBOL_GPL(dm_linear_map);
105 void dm_linear_status(struct dm_target *ti, status_type_t type,
106 unsigned status_flags, char *result, unsigned maxlen)
108 struct linear_c *lc = (struct linear_c *) ti->private;
111 case STATUSTYPE_INFO:
115 case STATUSTYPE_TABLE:
116 snprintf(result, maxlen, "%s %llu", lc->dev->name,
117 (unsigned long long)lc->start);
121 EXPORT_SYMBOL_GPL(dm_linear_status);
123 int dm_linear_prepare_ioctl(struct dm_target *ti,
124 struct block_device **bdev, fmode_t *mode)
126 struct linear_c *lc = (struct linear_c *) ti->private;
127 struct dm_dev *dev = lc->dev;
132 * Only pass ioctls through if the device sizes match exactly.
135 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
139 EXPORT_SYMBOL_GPL(dm_linear_prepare_ioctl);
141 int dm_linear_iterate_devices(struct dm_target *ti,
142 iterate_devices_callout_fn fn, void *data)
144 struct linear_c *lc = ti->private;
146 return fn(ti, lc->dev, lc->start, ti->len, data);
148 EXPORT_SYMBOL_GPL(dm_linear_iterate_devices);
150 static struct target_type linear_target = {
152 .version = {1, 2, 1},
153 .module = THIS_MODULE,
154 .ctr = dm_linear_ctr,
155 .dtr = dm_linear_dtr,
156 .map = dm_linear_map,
157 .status = dm_linear_status,
158 .prepare_ioctl = dm_linear_prepare_ioctl,
159 .iterate_devices = dm_linear_iterate_devices,
162 int __init dm_linear_init(void)
164 int r = dm_register_target(&linear_target);
167 DMERR("register failed %d", r);
172 void dm_linear_exit(void)
174 dm_unregister_target(&linear_target);