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/dax.h>
13 #include <linux/slab.h>
14 #include <linux/device-mapper.h>
16 #define DM_MSG_PREFIX "linear"
19 * Linear: maps a linear range of a device.
27 * Construct a linear mapping: <dev_path> <offset>
29 static int linear_ctr(struct dm_target
*ti
, unsigned int argc
, char **argv
)
32 unsigned long long tmp
;
37 ti
->error
= "Invalid argument count";
41 lc
= kmalloc(sizeof(*lc
), GFP_KERNEL
);
43 ti
->error
= "Cannot allocate linear context";
48 if (sscanf(argv
[1], "%llu%c", &tmp
, &dummy
) != 1 || tmp
!= (sector_t
)tmp
) {
49 ti
->error
= "Invalid device sector";
54 ret
= dm_get_device(ti
, argv
[0], dm_table_get_mode(ti
->table
), &lc
->dev
);
56 ti
->error
= "Device lookup failed";
60 ti
->num_flush_bios
= 1;
61 ti
->num_discard_bios
= 1;
62 ti
->num_write_same_bios
= 1;
63 ti
->num_write_zeroes_bios
= 1;
72 static void linear_dtr(struct dm_target
*ti
)
74 struct linear_c
*lc
= (struct linear_c
*) ti
->private;
76 dm_put_device(ti
, lc
->dev
);
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_set_dev(bio
, lc
->dev
->bdev
);
92 if (bio_sectors(bio
) || bio_op(bio
) == REQ_OP_ZONE_RESET
)
93 bio
->bi_iter
.bi_sector
=
94 linear_map_sector(ti
, bio
->bi_iter
.bi_sector
);
97 static int linear_map(struct dm_target
*ti
, struct bio
*bio
)
99 linear_map_bio(ti
, bio
);
101 return DM_MAPIO_REMAPPED
;
104 #ifdef CONFIG_BLK_DEV_ZONED
105 static int linear_end_io(struct dm_target
*ti
, struct bio
*bio
,
108 struct linear_c
*lc
= ti
->private;
110 if (!*error
&& bio_op(bio
) == REQ_OP_ZONE_REPORT
)
111 dm_remap_zone_report(ti
, bio
, lc
->start
);
113 return DM_ENDIO_DONE
;
117 static void linear_status(struct dm_target
*ti
, status_type_t type
,
118 unsigned status_flags
, char *result
, unsigned maxlen
)
120 struct linear_c
*lc
= (struct linear_c
*) ti
->private;
123 case STATUSTYPE_INFO
:
127 case STATUSTYPE_TABLE
:
128 snprintf(result
, maxlen
, "%s %llu", lc
->dev
->name
,
129 (unsigned long long)lc
->start
);
134 static int linear_prepare_ioctl(struct dm_target
*ti
,
135 struct block_device
**bdev
, fmode_t
*mode
)
137 struct linear_c
*lc
= (struct linear_c
*) ti
->private;
138 struct dm_dev
*dev
= lc
->dev
;
143 * Only pass ioctls through if the device sizes match exactly.
146 ti
->len
!= i_size_read(dev
->bdev
->bd_inode
) >> SECTOR_SHIFT
)
151 static int linear_iterate_devices(struct dm_target
*ti
,
152 iterate_devices_callout_fn fn
, void *data
)
154 struct linear_c
*lc
= ti
->private;
156 return fn(ti
, lc
->dev
, lc
->start
, ti
->len
, data
);
159 static long linear_dax_direct_access(struct dm_target
*ti
, pgoff_t pgoff
,
160 long nr_pages
, void **kaddr
, pfn_t
*pfn
)
163 struct linear_c
*lc
= ti
->private;
164 struct block_device
*bdev
= lc
->dev
->bdev
;
165 struct dax_device
*dax_dev
= lc
->dev
->dax_dev
;
166 sector_t dev_sector
, sector
= pgoff
* PAGE_SECTORS
;
168 dev_sector
= linear_map_sector(ti
, sector
);
169 ret
= bdev_dax_pgoff(bdev
, dev_sector
, nr_pages
* PAGE_SIZE
, &pgoff
);
172 return dax_direct_access(dax_dev
, pgoff
, nr_pages
, kaddr
, pfn
);
175 static size_t linear_dax_copy_from_iter(struct dm_target
*ti
, pgoff_t pgoff
,
176 void *addr
, size_t bytes
, struct iov_iter
*i
)
178 struct linear_c
*lc
= ti
->private;
179 struct block_device
*bdev
= lc
->dev
->bdev
;
180 struct dax_device
*dax_dev
= lc
->dev
->dax_dev
;
181 sector_t dev_sector
, sector
= pgoff
* PAGE_SECTORS
;
183 dev_sector
= linear_map_sector(ti
, sector
);
184 if (bdev_dax_pgoff(bdev
, dev_sector
, ALIGN(bytes
, PAGE_SIZE
), &pgoff
))
186 return dax_copy_from_iter(dax_dev
, pgoff
, addr
, bytes
, i
);
189 static struct target_type linear_target
= {
191 .version
= {1, 4, 0},
192 #ifdef CONFIG_BLK_DEV_ZONED
193 .end_io
= linear_end_io
,
194 .features
= DM_TARGET_PASSES_INTEGRITY
| DM_TARGET_ZONED_HM
,
196 .features
= DM_TARGET_PASSES_INTEGRITY
,
198 .module
= THIS_MODULE
,
202 .status
= linear_status
,
203 .prepare_ioctl
= linear_prepare_ioctl
,
204 .iterate_devices
= linear_iterate_devices
,
205 .direct_access
= linear_dax_direct_access
,
206 .dax_copy_from_iter
= linear_dax_copy_from_iter
,
209 int __init
dm_linear_init(void)
211 int r
= dm_register_target(&linear_target
);
214 DMERR("register failed %d", r
);
219 void dm_linear_exit(void)
221 dm_unregister_target(&linear_target
);