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_secure_erase_bios = 1;
63 ti->num_write_same_bios = 1;
64 ti->num_write_zeroes_bios = 1;
73 static void linear_dtr(struct dm_target *ti)
75 struct linear_c *lc = (struct linear_c *) ti->private;
77 dm_put_device(ti, lc->dev);
81 static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
83 struct linear_c *lc = ti->private;
85 return lc->start + dm_target_offset(ti, bi_sector);
88 static void linear_map_bio(struct dm_target *ti, struct bio *bio)
90 struct linear_c *lc = ti->private;
92 bio_set_dev(bio, lc->dev->bdev);
93 if (bio_sectors(bio) || op_is_zone_mgmt(bio_op(bio)))
94 bio->bi_iter.bi_sector =
95 linear_map_sector(ti, bio->bi_iter.bi_sector);
98 static int linear_map(struct dm_target *ti, struct bio *bio)
100 linear_map_bio(ti, bio);
102 return DM_MAPIO_REMAPPED;
105 static void 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);
122 static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
124 struct linear_c *lc = (struct linear_c *) ti->private;
125 struct dm_dev *dev = lc->dev;
130 * Only pass ioctls through if the device sizes match exactly.
133 ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
138 #ifdef CONFIG_BLK_DEV_ZONED
139 static int linear_report_zones(struct dm_target *ti,
140 struct dm_report_zones_args *args, unsigned int nr_zones)
142 struct linear_c *lc = ti->private;
144 return dm_report_zones(lc->dev->bdev, lc->start,
145 linear_map_sector(ti, args->next_sector),
149 #define linear_report_zones NULL
152 static int linear_iterate_devices(struct dm_target *ti,
153 iterate_devices_callout_fn fn, void *data)
155 struct linear_c *lc = ti->private;
157 return fn(ti, lc->dev, lc->start, ti->len, data);
160 #if IS_ENABLED(CONFIG_DAX_DRIVER)
161 static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
162 long nr_pages, void **kaddr, pfn_t *pfn)
165 struct linear_c *lc = ti->private;
166 struct block_device *bdev = lc->dev->bdev;
167 struct dax_device *dax_dev = lc->dev->dax_dev;
168 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
170 dev_sector = linear_map_sector(ti, sector);
171 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
174 return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
177 static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
178 void *addr, size_t bytes, struct iov_iter *i)
180 struct linear_c *lc = ti->private;
181 struct block_device *bdev = lc->dev->bdev;
182 struct dax_device *dax_dev = lc->dev->dax_dev;
183 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
185 dev_sector = linear_map_sector(ti, sector);
186 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
188 return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
191 static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
192 void *addr, size_t bytes, struct iov_iter *i)
194 struct linear_c *lc = ti->private;
195 struct block_device *bdev = lc->dev->bdev;
196 struct dax_device *dax_dev = lc->dev->dax_dev;
197 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
199 dev_sector = linear_map_sector(ti, sector);
200 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
202 return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
205 static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
209 struct linear_c *lc = ti->private;
210 struct block_device *bdev = lc->dev->bdev;
211 struct dax_device *dax_dev = lc->dev->dax_dev;
212 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
214 dev_sector = linear_map_sector(ti, sector);
215 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
218 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
222 #define linear_dax_direct_access NULL
223 #define linear_dax_copy_from_iter NULL
224 #define linear_dax_copy_to_iter NULL
225 #define linear_dax_zero_page_range NULL
228 static struct target_type linear_target = {
230 .version = {1, 4, 0},
231 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
232 DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
233 .report_zones = linear_report_zones,
234 .module = THIS_MODULE,
238 .status = linear_status,
239 .prepare_ioctl = linear_prepare_ioctl,
240 .iterate_devices = linear_iterate_devices,
241 .direct_access = linear_dax_direct_access,
242 .dax_copy_from_iter = linear_dax_copy_from_iter,
243 .dax_copy_to_iter = linear_dax_copy_to_iter,
244 .dax_zero_page_range = linear_dax_zero_page_range,
247 int __init dm_linear_init(void)
249 int r = dm_register_target(&linear_target);
252 DMERR("register failed %d", r);
257 void dm_linear_exit(void)
259 dm_unregister_target(&linear_target);