Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Mikulas Patocka | 586e80e | 2008-10-21 17:44:59 +0100 | [diff] [blame] | 13 | #include <linux/device-mapper.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 15 | #define DM_MSG_PREFIX "linear" |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 31 | unsigned long long tmp; |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 32 | char dummy; |
Vivek Goyal | e80d1c8 | 2015-07-31 09:20:36 -0400 | [diff] [blame] | 33 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
| 35 | if (argc != 2) { |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 36 | ti->error = "Invalid argument count"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | return -EINVAL; |
| 38 | } |
| 39 | |
| 40 | lc = kmalloc(sizeof(*lc), GFP_KERNEL); |
| 41 | if (lc == NULL) { |
| 42 | ti->error = "dm-linear: Cannot allocate linear context"; |
| 43 | return -ENOMEM; |
| 44 | } |
| 45 | |
Vivek Goyal | e80d1c8 | 2015-07-31 09:20:36 -0400 | [diff] [blame] | 46 | ret = -EINVAL; |
Mikulas Patocka | 31998ef | 2012-03-28 18:41:26 +0100 | [diff] [blame] | 47 | if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | ti->error = "dm-linear: Invalid device sector"; |
| 49 | goto bad; |
| 50 | } |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 51 | lc->start = tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Vivek Goyal | e80d1c8 | 2015-07-31 09:20:36 -0400 | [diff] [blame] | 53 | ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev); |
| 54 | if (ret) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | ti->error = "dm-linear: Device lookup failed"; |
| 56 | goto bad; |
| 57 | } |
| 58 | |
Alasdair G Kergon | 55a62ee | 2013-03-01 22:45:47 +0000 | [diff] [blame] | 59 | ti->num_flush_bios = 1; |
| 60 | ti->num_discard_bios = 1; |
| 61 | ti->num_write_same_bios = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | ti->private = lc; |
| 63 | return 0; |
| 64 | |
| 65 | bad: |
| 66 | kfree(lc); |
Vivek Goyal | e80d1c8 | 2015-07-31 09:20:36 -0400 | [diff] [blame] | 67 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Milan Broz | 7bc3447 | 2008-07-21 12:00:38 +0100 | [diff] [blame] | 78 | static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector) |
| 79 | { |
| 80 | struct linear_c *lc = ti->private; |
| 81 | |
Alasdair G Kergon | b441a262 | 2010-08-12 04:14:11 +0100 | [diff] [blame] | 82 | return lc->start + dm_target_offset(ti, bi_sector); |
Milan Broz | 7bc3447 | 2008-07-21 12:00:38 +0100 | [diff] [blame] | 83 | } |
| 84 | |
| 85 | static 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; |
Mikulas Patocka | 433bcac | 2009-06-22 10:12:22 +0100 | [diff] [blame] | 90 | if (bio_sectors(bio)) |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 91 | bio->bi_iter.bi_sector = |
| 92 | linear_map_sector(ti, bio->bi_iter.bi_sector); |
Milan Broz | 7bc3447 | 2008-07-21 12:00:38 +0100 | [diff] [blame] | 93 | } |
| 94 | |
Mikulas Patocka | 7de3ee5 | 2012-12-21 20:23:41 +0000 | [diff] [blame] | 95 | static int linear_map(struct dm_target *ti, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | { |
Milan Broz | 7bc3447 | 2008-07-21 12:00:38 +0100 | [diff] [blame] | 97 | linear_map_bio(ti, bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | |
Kiyoshi Ueda | d2a7ad2 | 2006-12-08 02:41:06 -0800 | [diff] [blame] | 99 | return DM_MAPIO_REMAPPED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | } |
| 101 | |
Mikulas Patocka | fd7c092 | 2013-03-01 22:45:44 +0000 | [diff] [blame] | 102 | static void linear_status(struct dm_target *ti, status_type_t type, |
| 103 | unsigned status_flags, char *result, unsigned maxlen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Andrew Morton | 4ee218c | 2006-03-27 01:17:48 -0800 | [diff] [blame] | 113 | snprintf(result, maxlen, "%s %llu", lc->dev->name, |
| 114 | (unsigned long long)lc->start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | break; |
| 116 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | } |
| 118 | |
Al Viro | 647b3d0 | 2007-08-28 22:15:59 -0400 | [diff] [blame] | 119 | static int linear_ioctl(struct dm_target *ti, unsigned int cmd, |
Milan Broz | ab17ffa | 2006-10-03 01:15:18 -0700 | [diff] [blame] | 120 | unsigned long arg) |
| 121 | { |
| 122 | struct linear_c *lc = (struct linear_c *) ti->private; |
Paolo Bonzini | ec8013b | 2012-01-12 16:01:29 +0100 | [diff] [blame] | 123 | struct dm_dev *dev = lc->dev; |
| 124 | int r = 0; |
| 125 | |
| 126 | /* |
| 127 | * Only pass ioctls through if the device sizes match exactly. |
| 128 | */ |
| 129 | if (lc->start || |
| 130 | ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT) |
| 131 | r = scsi_verify_blk_ioctl(NULL, cmd); |
| 132 | |
| 133 | return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg); |
Milan Broz | ab17ffa | 2006-10-03 01:15:18 -0700 | [diff] [blame] | 134 | } |
| 135 | |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 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 | |
Mike Snitzer | 5dea271 | 2009-07-23 20:30:42 +0100 | [diff] [blame] | 141 | return fn(ti, lc->dev, lc->start, ti->len, data); |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 142 | } |
| 143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | static struct target_type linear_target = { |
| 145 | .name = "linear", |
Mikulas Patocka | fd7c092 | 2013-03-01 22:45:44 +0000 | [diff] [blame] | 146 | .version = {1, 2, 1}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | .module = THIS_MODULE, |
| 148 | .ctr = linear_ctr, |
| 149 | .dtr = linear_dtr, |
| 150 | .map = linear_map, |
| 151 | .status = linear_status, |
Milan Broz | ab17ffa | 2006-10-03 01:15:18 -0700 | [diff] [blame] | 152 | .ioctl = linear_ioctl, |
Mike Snitzer | af4874e | 2009-06-22 10:12:33 +0100 | [diff] [blame] | 153 | .iterate_devices = linear_iterate_devices, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | }; |
| 155 | |
| 156 | int __init dm_linear_init(void) |
| 157 | { |
| 158 | int r = dm_register_target(&linear_target); |
| 159 | |
| 160 | if (r < 0) |
Alasdair G Kergon | 72d9486 | 2006-06-26 00:27:35 -0700 | [diff] [blame] | 161 | DMERR("register failed %d", r); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
| 163 | return r; |
| 164 | } |
| 165 | |
| 166 | void dm_linear_exit(void) |
| 167 | { |
Mikulas Patocka | 10d3bd0 | 2009-01-06 03:04:58 +0000 | [diff] [blame] | 168 | dm_unregister_target(&linear_target); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | } |