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3bd94003 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
18a5bf27 SB |
2 | /* |
3 | * Copyright (C) 2017 Intel Corporation. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include "dm.h" | |
9 | ||
10 | #include <linux/module.h> | |
18a5bf27 SB |
11 | |
12 | struct unstripe_c { | |
13 | struct dm_dev *dev; | |
14 | sector_t physical_start; | |
15 | ||
16 | uint32_t stripes; | |
17 | ||
18 | uint32_t unstripe; | |
19 | sector_t unstripe_width; | |
20 | sector_t unstripe_offset; | |
21 | ||
22 | uint32_t chunk_size; | |
23 | u8 chunk_shift; | |
24 | }; | |
25 | ||
26 | #define DM_MSG_PREFIX "unstriped" | |
27 | ||
28 | static void cleanup_unstripe(struct unstripe_c *uc, struct dm_target *ti) | |
29 | { | |
30 | if (uc->dev) | |
31 | dm_put_device(ti, uc->dev); | |
32 | kfree(uc); | |
33 | } | |
34 | ||
35 | /* | |
36 | * Contruct an unstriped mapping. | |
37 | * <number of stripes> <chunk size> <stripe #> <dev_path> <offset> | |
38 | */ | |
39 | static int unstripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
40 | { | |
41 | struct unstripe_c *uc; | |
cc656619 | 42 | sector_t tmp_len; |
18a5bf27 SB |
43 | unsigned long long start; |
44 | char dummy; | |
45 | ||
46 | if (argc != 5) { | |
47 | ti->error = "Invalid number of arguments"; | |
48 | return -EINVAL; | |
49 | } | |
50 | ||
51 | uc = kzalloc(sizeof(*uc), GFP_KERNEL); | |
52 | if (!uc) { | |
53 | ti->error = "Memory allocation for unstriped context failed"; | |
54 | return -ENOMEM; | |
55 | } | |
56 | ||
57 | if (kstrtouint(argv[0], 10, &uc->stripes) || !uc->stripes) { | |
58 | ti->error = "Invalid stripe count"; | |
59 | goto err; | |
60 | } | |
61 | ||
62 | if (kstrtouint(argv[1], 10, &uc->chunk_size) || !uc->chunk_size) { | |
63 | ti->error = "Invalid chunk_size"; | |
64 | goto err; | |
65 | } | |
66 | ||
18a5bf27 SB |
67 | if (kstrtouint(argv[2], 10, &uc->unstripe)) { |
68 | ti->error = "Invalid stripe number"; | |
69 | goto err; | |
70 | } | |
71 | ||
72 | if (uc->unstripe > uc->stripes && uc->stripes > 1) { | |
73 | ti->error = "Please provide stripe between [0, # of stripes]"; | |
74 | goto err; | |
75 | } | |
76 | ||
77 | if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &uc->dev)) { | |
78 | ti->error = "Couldn't get striped device"; | |
79 | goto err; | |
80 | } | |
81 | ||
ef87bfc2 | 82 | if (sscanf(argv[4], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) { |
18a5bf27 SB |
83 | ti->error = "Invalid striped device offset"; |
84 | goto err; | |
85 | } | |
86 | uc->physical_start = start; | |
87 | ||
88 | uc->unstripe_offset = uc->unstripe * uc->chunk_size; | |
89 | uc->unstripe_width = (uc->stripes - 1) * uc->chunk_size; | |
2ae600cd | 90 | uc->chunk_shift = is_power_of_2(uc->chunk_size) ? fls(uc->chunk_size) - 1 : 0; |
18a5bf27 | 91 | |
cc656619 | 92 | tmp_len = ti->len; |
18a5bf27 SB |
93 | if (sector_div(tmp_len, uc->chunk_size)) { |
94 | ti->error = "Target length not divisible by chunk size"; | |
95 | goto err; | |
96 | } | |
97 | ||
98 | if (dm_set_target_max_io_len(ti, uc->chunk_size)) { | |
99 | ti->error = "Failed to set max io len"; | |
100 | goto err; | |
101 | } | |
102 | ||
103 | ti->private = uc; | |
104 | return 0; | |
105 | err: | |
106 | cleanup_unstripe(uc, ti); | |
107 | return -EINVAL; | |
108 | } | |
109 | ||
110 | static void unstripe_dtr(struct dm_target *ti) | |
111 | { | |
112 | struct unstripe_c *uc = ti->private; | |
113 | ||
114 | cleanup_unstripe(uc, ti); | |
115 | } | |
116 | ||
117 | static sector_t map_to_core(struct dm_target *ti, struct bio *bio) | |
118 | { | |
119 | struct unstripe_c *uc = ti->private; | |
120 | sector_t sector = bio->bi_iter.bi_sector; | |
2ae600cd | 121 | sector_t tmp_sector = sector; |
18a5bf27 SB |
122 | |
123 | /* Shift us up to the right "row" on the stripe */ | |
2ae600cd HM |
124 | if (uc->chunk_shift) |
125 | tmp_sector >>= uc->chunk_shift; | |
126 | else | |
127 | sector_div(tmp_sector, uc->chunk_size); | |
18a5bf27 | 128 | |
2ae600cd | 129 | sector += uc->unstripe_width * tmp_sector; |
18a5bf27 | 130 | |
2ae600cd HM |
131 | /* Account for what stripe we're operating on */ |
132 | return sector + uc->unstripe_offset; | |
18a5bf27 SB |
133 | } |
134 | ||
135 | static int unstripe_map(struct dm_target *ti, struct bio *bio) | |
136 | { | |
137 | struct unstripe_c *uc = ti->private; | |
138 | ||
139 | bio_set_dev(bio, uc->dev->bdev); | |
140 | bio->bi_iter.bi_sector = map_to_core(ti, bio) + uc->physical_start; | |
141 | ||
142 | return DM_MAPIO_REMAPPED; | |
143 | } | |
144 | ||
145 | static void unstripe_status(struct dm_target *ti, status_type_t type, | |
146 | unsigned int status_flags, char *result, unsigned int maxlen) | |
147 | { | |
148 | struct unstripe_c *uc = ti->private; | |
149 | unsigned int sz = 0; | |
150 | ||
151 | switch (type) { | |
152 | case STATUSTYPE_INFO: | |
153 | break; | |
154 | ||
155 | case STATUSTYPE_TABLE: | |
156 | DMEMIT("%d %llu %d %s %llu", | |
157 | uc->stripes, (unsigned long long)uc->chunk_size, uc->unstripe, | |
158 | uc->dev->name, (unsigned long long)uc->physical_start); | |
159 | break; | |
8ec45662 TS |
160 | |
161 | case STATUSTYPE_IMA: | |
162 | *result = '\0'; | |
163 | break; | |
18a5bf27 SB |
164 | } |
165 | } | |
166 | ||
167 | static int unstripe_iterate_devices(struct dm_target *ti, | |
168 | iterate_devices_callout_fn fn, void *data) | |
169 | { | |
170 | struct unstripe_c *uc = ti->private; | |
171 | ||
172 | return fn(ti, uc->dev, uc->physical_start, ti->len, data); | |
173 | } | |
174 | ||
175 | static void unstripe_io_hints(struct dm_target *ti, | |
176 | struct queue_limits *limits) | |
177 | { | |
178 | struct unstripe_c *uc = ti->private; | |
179 | ||
180 | limits->chunk_sectors = uc->chunk_size; | |
181 | } | |
182 | ||
183 | static struct target_type unstripe_target = { | |
184 | .name = "unstriped", | |
2ae600cd | 185 | .version = {1, 1, 0}, |
410fe220 | 186 | .features = DM_TARGET_NOWAIT, |
18a5bf27 SB |
187 | .module = THIS_MODULE, |
188 | .ctr = unstripe_ctr, | |
189 | .dtr = unstripe_dtr, | |
190 | .map = unstripe_map, | |
191 | .status = unstripe_status, | |
192 | .iterate_devices = unstripe_iterate_devices, | |
193 | .io_hints = unstripe_io_hints, | |
194 | }; | |
3664ff82 | 195 | module_dm(unstripe); |
18a5bf27 SB |
196 | |
197 | MODULE_DESCRIPTION(DM_NAME " unstriped target"); | |
ba5dfbb7 | 198 | MODULE_ALIAS("dm-unstriped"); |
18a5bf27 SB |
199 | MODULE_AUTHOR("Scott Bauer <scott.bauer@intel.com>"); |
200 | MODULE_LICENSE("GPL"); |