Merge tag 'xtensa-20220804' of https://github.com/jcmvbkbc/linux-xtensa
[linux-2.6-block.git] / drivers / md / dm-linear.c
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"
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>
15
16 #define DM_MSG_PREFIX "linear"
17
18 /*
19  * Linear: maps a linear range of a device.
20  */
21 struct linear_c {
22         struct dm_dev *dev;
23         sector_t start;
24 };
25
26 /*
27  * Construct a linear mapping: <dev_path> <offset>
28  */
29 static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
30 {
31         struct linear_c *lc;
32         unsigned long long tmp;
33         char dummy;
34         int ret;
35
36         if (argc != 2) {
37                 ti->error = "Invalid argument count";
38                 return -EINVAL;
39         }
40
41         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
42         if (lc == NULL) {
43                 ti->error = "Cannot allocate linear context";
44                 return -ENOMEM;
45         }
46
47         ret = -EINVAL;
48         if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
49                 ti->error = "Invalid device sector";
50                 goto bad;
51         }
52         lc->start = tmp;
53
54         ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
55         if (ret) {
56                 ti->error = "Device lookup failed";
57                 goto bad;
58         }
59
60         ti->num_flush_bios = 1;
61         ti->num_discard_bios = 1;
62         ti->num_secure_erase_bios = 1;
63         ti->num_write_zeroes_bios = 1;
64         ti->private = lc;
65         return 0;
66
67       bad:
68         kfree(lc);
69         return ret;
70 }
71
72 static void linear_dtr(struct dm_target *ti)
73 {
74         struct linear_c *lc = (struct linear_c *) ti->private;
75
76         dm_put_device(ti, lc->dev);
77         kfree(lc);
78 }
79
80 static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
81 {
82         struct linear_c *lc = ti->private;
83
84         return lc->start + dm_target_offset(ti, bi_sector);
85 }
86
87 static int linear_map(struct dm_target *ti, struct bio *bio)
88 {
89         struct linear_c *lc = ti->private;
90
91         bio_set_dev(bio, lc->dev->bdev);
92         bio->bi_iter.bi_sector = linear_map_sector(ti, bio->bi_iter.bi_sector);
93
94         return DM_MAPIO_REMAPPED;
95 }
96
97 static void linear_status(struct dm_target *ti, status_type_t type,
98                           unsigned status_flags, char *result, unsigned maxlen)
99 {
100         struct linear_c *lc = (struct linear_c *) ti->private;
101         size_t sz = 0;
102
103         switch (type) {
104         case STATUSTYPE_INFO:
105                 result[0] = '\0';
106                 break;
107
108         case STATUSTYPE_TABLE:
109                 DMEMIT("%s %llu", lc->dev->name, (unsigned long long)lc->start);
110                 break;
111
112         case STATUSTYPE_IMA:
113                 DMEMIT_TARGET_NAME_VERSION(ti->type);
114                 DMEMIT(",device_name=%s,start=%llu;", lc->dev->name,
115                        (unsigned long long)lc->start);
116                 break;
117         }
118 }
119
120 static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
121 {
122         struct linear_c *lc = (struct linear_c *) ti->private;
123         struct dm_dev *dev = lc->dev;
124
125         *bdev = dev->bdev;
126
127         /*
128          * Only pass ioctls through if the device sizes match exactly.
129          */
130         if (lc->start || ti->len != bdev_nr_sectors(dev->bdev))
131                 return 1;
132         return 0;
133 }
134
135 #ifdef CONFIG_BLK_DEV_ZONED
136 static int linear_report_zones(struct dm_target *ti,
137                 struct dm_report_zones_args *args, unsigned int nr_zones)
138 {
139         struct linear_c *lc = ti->private;
140
141         return dm_report_zones(lc->dev->bdev, lc->start,
142                                linear_map_sector(ti, args->next_sector),
143                                args, nr_zones);
144 }
145 #else
146 #define linear_report_zones NULL
147 #endif
148
149 static int linear_iterate_devices(struct dm_target *ti,
150                                   iterate_devices_callout_fn fn, void *data)
151 {
152         struct linear_c *lc = ti->private;
153
154         return fn(ti, lc->dev, lc->start, ti->len, data);
155 }
156
157 #if IS_ENABLED(CONFIG_FS_DAX)
158 static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
159 {
160         struct linear_c *lc = ti->private;
161         sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
162
163         *pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT;
164         return lc->dev->dax_dev;
165 }
166
167 static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
168                 long nr_pages, enum dax_access_mode mode, void **kaddr,
169                 pfn_t *pfn)
170 {
171         struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
172
173         return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
174 }
175
176 static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
177                                       size_t nr_pages)
178 {
179         struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
180
181         return dax_zero_page_range(dax_dev, pgoff, nr_pages);
182 }
183
184 static size_t linear_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
185                 void *addr, size_t bytes, struct iov_iter *i)
186 {
187         struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
188
189         return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
190 }
191
192 #else
193 #define linear_dax_direct_access NULL
194 #define linear_dax_zero_page_range NULL
195 #define linear_dax_recovery_write NULL
196 #endif
197
198 static struct target_type linear_target = {
199         .name   = "linear",
200         .version = {1, 4, 0},
201         .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
202                     DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
203         .report_zones = linear_report_zones,
204         .module = THIS_MODULE,
205         .ctr    = linear_ctr,
206         .dtr    = linear_dtr,
207         .map    = linear_map,
208         .status = linear_status,
209         .prepare_ioctl = linear_prepare_ioctl,
210         .iterate_devices = linear_iterate_devices,
211         .direct_access = linear_dax_direct_access,
212         .dax_zero_page_range = linear_dax_zero_page_range,
213         .dax_recovery_write = linear_dax_recovery_write,
214 };
215
216 int __init dm_linear_init(void)
217 {
218         int r = dm_register_target(&linear_target);
219
220         if (r < 0)
221                 DMERR("register failed %d", r);
222
223         return r;
224 }
225
226 void dm_linear_exit(void)
227 {
228         dm_unregister_target(&linear_target);
229 }