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1da177e4 LT |
1 | /* |
2 | linear.c : Multiple Devices driver for Linux | |
3 | Copyright (C) 1994-96 Marc ZYNGIER | |
4 | <zyngier@ufr-info-p7.ibp.fr> or | |
5 | <maz@gloups.fdn.fr> | |
6 | ||
7 | Linear mode management functions. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2, or (at your option) | |
12 | any later version. | |
f72ffdd6 | 13 | |
1da177e4 LT |
14 | You should have received a copy of the GNU General Public License |
15 | (for example /usr/src/linux/COPYING); if not, write to the Free | |
f72ffdd6 | 16 | Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
1da177e4 LT |
17 | */ |
18 | ||
bff61975 N |
19 | #include <linux/blkdev.h> |
20 | #include <linux/raid/md_u.h> | |
bff61975 | 21 | #include <linux/seq_file.h> |
056075c7 | 22 | #include <linux/module.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
43b2e5d8 | 24 | #include "md.h" |
ef740c37 | 25 | #include "linear.h" |
1da177e4 | 26 | |
1da177e4 | 27 | /* |
f72ffdd6 | 28 | * find which device holds a particular offset |
1da177e4 | 29 | */ |
a7120771 | 30 | static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector) |
1da177e4 | 31 | { |
aece3d1f | 32 | int lo, mid, hi; |
e849b938 | 33 | struct linear_conf *conf; |
1da177e4 | 34 | |
aece3d1f SS |
35 | lo = 0; |
36 | hi = mddev->raid_disks - 1; | |
3be260cc | 37 | conf = mddev->private; |
1da177e4 | 38 | |
aece3d1f SS |
39 | /* |
40 | * Binary Search | |
41 | */ | |
42 | ||
43 | while (hi > lo) { | |
44 | ||
45 | mid = (hi + lo) / 2; | |
46 | if (sector < conf->disks[mid].end_sector) | |
47 | hi = mid; | |
48 | else | |
49 | lo = mid + 1; | |
50 | } | |
51 | ||
52 | return conf->disks + lo; | |
1da177e4 LT |
53 | } |
54 | ||
5c675f83 | 55 | static int linear_congested(struct mddev *mddev, int bits) |
26be34dc | 56 | { |
e849b938 | 57 | struct linear_conf *conf; |
26be34dc N |
58 | int i, ret = 0; |
59 | ||
3be260cc | 60 | conf = mddev->private; |
af11c397 | 61 | |
26be34dc | 62 | for (i = 0; i < mddev->raid_disks && !ret ; i++) { |
165125e1 | 63 | struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev); |
26be34dc N |
64 | ret |= bdi_congested(&q->backing_dev_info, bits); |
65 | } | |
af11c397 | 66 | |
26be34dc N |
67 | return ret; |
68 | } | |
69 | ||
fd01b88c | 70 | static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks) |
80c3a6ce | 71 | { |
e849b938 | 72 | struct linear_conf *conf; |
af11c397 | 73 | sector_t array_sectors; |
80c3a6ce | 74 | |
3be260cc | 75 | conf = mddev->private; |
80c3a6ce DW |
76 | WARN_ONCE(sectors || raid_disks, |
77 | "%s does not support generic reshape\n", __func__); | |
af11c397 | 78 | array_sectors = conf->array_sectors; |
80c3a6ce | 79 | |
af11c397 | 80 | return array_sectors; |
80c3a6ce DW |
81 | } |
82 | ||
e849b938 | 83 | static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks) |
1da177e4 | 84 | { |
e849b938 | 85 | struct linear_conf *conf; |
3cb03002 | 86 | struct md_rdev *rdev; |
45d4582f | 87 | int i, cnt; |
f1cad2b6 | 88 | bool discard_supported = false; |
1da177e4 | 89 | |
a7120771 | 90 | conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info), |
1da177e4 LT |
91 | GFP_KERNEL); |
92 | if (!conf) | |
7c7546cc N |
93 | return NULL; |
94 | ||
1da177e4 | 95 | cnt = 0; |
d6e22150 | 96 | conf->array_sectors = 0; |
1da177e4 | 97 | |
dafb20fa | 98 | rdev_for_each(rdev, mddev) { |
1da177e4 | 99 | int j = rdev->raid_disk; |
a7120771 | 100 | struct dev_info *disk = conf->disks + j; |
13f2682b | 101 | sector_t sectors; |
1da177e4 | 102 | |
13864515 | 103 | if (j < 0 || j >= raid_disks || disk->rdev) { |
2dc40f80 N |
104 | printk(KERN_ERR "md/linear:%s: disk numbering problem. Aborting!\n", |
105 | mdname(mddev)); | |
1da177e4 LT |
106 | goto out; |
107 | } | |
108 | ||
109 | disk->rdev = rdev; | |
13f2682b N |
110 | if (mddev->chunk_sectors) { |
111 | sectors = rdev->sectors; | |
112 | sector_div(sectors, mddev->chunk_sectors); | |
113 | rdev->sectors = sectors * mddev->chunk_sectors; | |
114 | } | |
1da177e4 | 115 | |
8f6c2e4b MP |
116 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
117 | rdev->data_offset << 9); | |
1da177e4 | 118 | |
dd8ac336 | 119 | conf->array_sectors += rdev->sectors; |
1da177e4 | 120 | cnt++; |
4db7cdc8 | 121 | |
f1cad2b6 SL |
122 | if (blk_queue_discard(bdev_get_queue(rdev->bdev))) |
123 | discard_supported = true; | |
1da177e4 | 124 | } |
7c7546cc | 125 | if (cnt != raid_disks) { |
2dc40f80 N |
126 | printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n", |
127 | mdname(mddev)); | |
1da177e4 LT |
128 | goto out; |
129 | } | |
130 | ||
f1cad2b6 SL |
131 | if (!discard_supported) |
132 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); | |
133 | else | |
134 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); | |
135 | ||
1da177e4 | 136 | /* |
45d4582f | 137 | * Here we calculate the device offsets. |
1da177e4 | 138 | */ |
4db7cdc8 SS |
139 | conf->disks[0].end_sector = conf->disks[0].rdev->sectors; |
140 | ||
a778b73f | 141 | for (i = 1; i < raid_disks; i++) |
4db7cdc8 SS |
142 | conf->disks[i].end_sector = |
143 | conf->disks[i-1].end_sector + | |
144 | conf->disks[i].rdev->sectors; | |
15945fee | 145 | |
7c7546cc N |
146 | return conf; |
147 | ||
148 | out: | |
149 | kfree(conf); | |
150 | return NULL; | |
151 | } | |
152 | ||
fd01b88c | 153 | static int linear_run (struct mddev *mddev) |
7c7546cc | 154 | { |
e849b938 | 155 | struct linear_conf *conf; |
98d5561b | 156 | int ret; |
7c7546cc | 157 | |
0894cc30 AN |
158 | if (md_check_no_bitmap(mddev)) |
159 | return -EINVAL; | |
7c7546cc N |
160 | conf = linear_conf(mddev, mddev->raid_disks); |
161 | ||
162 | if (!conf) | |
163 | return 1; | |
164 | mddev->private = conf; | |
1f403624 | 165 | md_set_array_sectors(mddev, linear_size(mddev, 0, 0)); |
7c7546cc | 166 | |
98d5561b | 167 | ret = md_integrity_register(mddev); |
168 | if (ret) { | |
169 | kfree(conf); | |
170 | mddev->private = NULL; | |
171 | } | |
172 | return ret; | |
7c7546cc | 173 | } |
1da177e4 | 174 | |
fd01b88c | 175 | static int linear_add(struct mddev *mddev, struct md_rdev *rdev) |
7c7546cc N |
176 | { |
177 | /* Adding a drive to a linear array allows the array to grow. | |
178 | * It is permitted if the new drive has a matching superblock | |
179 | * already on it, with raid_disk equal to raid_disks. | |
180 | * It is achieved by creating a new linear_private_data structure | |
181 | * and swapping it in in-place of the current one. | |
182 | * The current one is never freed until the array is stopped. | |
183 | * This avoids races. | |
184 | */ | |
e849b938 | 185 | struct linear_conf *newconf, *oldconf; |
7c7546cc | 186 | |
a778b73f | 187 | if (rdev->saved_raid_disk != mddev->raid_disks) |
7c7546cc N |
188 | return -EINVAL; |
189 | ||
a778b73f | 190 | rdev->raid_disk = rdev->saved_raid_disk; |
09cd9270 | 191 | rdev->saved_raid_disk = -1; |
a778b73f | 192 | |
7c7546cc N |
193 | newconf = linear_conf(mddev,mddev->raid_disks+1); |
194 | ||
195 | if (!newconf) | |
196 | return -ENOMEM; | |
197 | ||
3be260cc N |
198 | mddev_suspend(mddev); |
199 | oldconf = mddev->private; | |
7c7546cc | 200 | mddev->raid_disks++; |
3be260cc | 201 | mddev->private = newconf; |
1f403624 | 202 | md_set_array_sectors(mddev, linear_size(mddev, 0, 0)); |
f233ea5c | 203 | set_capacity(mddev->gendisk, mddev->array_sectors); |
3be260cc | 204 | mddev_resume(mddev); |
449aad3e | 205 | revalidate_disk(mddev->gendisk); |
3be260cc | 206 | kfree(oldconf); |
7c7546cc | 207 | return 0; |
1da177e4 LT |
208 | } |
209 | ||
afa0f557 | 210 | static void linear_free(struct mddev *mddev, void *priv) |
1da177e4 | 211 | { |
afa0f557 | 212 | struct linear_conf *conf = priv; |
af11c397 | 213 | |
495d3573 | 214 | kfree(conf); |
1da177e4 LT |
215 | } |
216 | ||
b4fdcb02 | 217 | static void linear_make_request(struct mddev *mddev, struct bio *bio) |
1da177e4 | 218 | { |
20d0189b | 219 | char b[BDEVNAME_SIZE]; |
a7120771 | 220 | struct dev_info *tmp_dev; |
20d0189b KO |
221 | struct bio *split; |
222 | sector_t start_sector, end_sector, data_offset; | |
1da177e4 | 223 | |
28a8f0d3 | 224 | if (unlikely(bio->bi_rw & REQ_PREFLUSH)) { |
e9c7469b | 225 | md_flush_request(mddev, bio); |
5a7bbad2 | 226 | return; |
e5dcdd80 N |
227 | } |
228 | ||
20d0189b | 229 | do { |
20d0189b KO |
230 | tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector); |
231 | start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors; | |
232 | end_sector = tmp_dev->end_sector; | |
233 | data_offset = tmp_dev->rdev->data_offset; | |
234 | bio->bi_bdev = tmp_dev->rdev->bdev; | |
6283815d | 235 | |
20d0189b KO |
236 | if (unlikely(bio->bi_iter.bi_sector >= end_sector || |
237 | bio->bi_iter.bi_sector < start_sector)) | |
238 | goto out_of_bounds; | |
239 | ||
240 | if (unlikely(bio_end_sector(bio) > end_sector)) { | |
241 | /* This bio crosses a device boundary, so we have to | |
242 | * split it. | |
243 | */ | |
244 | split = bio_split(bio, end_sector - | |
245 | bio->bi_iter.bi_sector, | |
246 | GFP_NOIO, fs_bio_set); | |
247 | bio_chain(split, bio); | |
248 | } else { | |
249 | split = bio; | |
250 | } | |
f1cad2b6 | 251 | |
20d0189b KO |
252 | split->bi_iter.bi_sector = split->bi_iter.bi_sector - |
253 | start_sector + data_offset; | |
254 | ||
796a5cf0 | 255 | if (unlikely((bio_op(split) == REQ_OP_DISCARD) && |
20d0189b KO |
256 | !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { |
257 | /* Just ignore it */ | |
4246a0b6 | 258 | bio_endio(split); |
20d0189b KO |
259 | } else |
260 | generic_make_request(split); | |
261 | } while (split != bio); | |
262 | return; | |
263 | ||
264 | out_of_bounds: | |
265 | printk(KERN_ERR | |
266 | "md/linear:%s: make_request: Sector %llu out of bounds on " | |
267 | "dev %s: %llu sectors, offset %llu\n", | |
268 | mdname(mddev), | |
269 | (unsigned long long)bio->bi_iter.bi_sector, | |
270 | bdevname(tmp_dev->rdev->bdev, b), | |
271 | (unsigned long long)tmp_dev->rdev->sectors, | |
272 | (unsigned long long)start_sector); | |
273 | bio_io_error(bio); | |
1da177e4 LT |
274 | } |
275 | ||
fd01b88c | 276 | static void linear_status (struct seq_file *seq, struct mddev *mddev) |
1da177e4 LT |
277 | { |
278 | ||
9d8f0363 | 279 | seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2); |
1da177e4 LT |
280 | } |
281 | ||
3be260cc N |
282 | static void linear_quiesce(struct mddev *mddev, int state) |
283 | { | |
284 | } | |
285 | ||
84fc4b56 | 286 | static struct md_personality linear_personality = |
1da177e4 LT |
287 | { |
288 | .name = "linear", | |
2604b703 | 289 | .level = LEVEL_LINEAR, |
1da177e4 LT |
290 | .owner = THIS_MODULE, |
291 | .make_request = linear_make_request, | |
292 | .run = linear_run, | |
afa0f557 | 293 | .free = linear_free, |
1da177e4 | 294 | .status = linear_status, |
7c7546cc | 295 | .hot_add_disk = linear_add, |
80c3a6ce | 296 | .size = linear_size, |
3be260cc | 297 | .quiesce = linear_quiesce, |
5c675f83 | 298 | .congested = linear_congested, |
1da177e4 LT |
299 | }; |
300 | ||
301 | static int __init linear_init (void) | |
302 | { | |
2604b703 | 303 | return register_md_personality (&linear_personality); |
1da177e4 LT |
304 | } |
305 | ||
306 | static void linear_exit (void) | |
307 | { | |
2604b703 | 308 | unregister_md_personality (&linear_personality); |
1da177e4 LT |
309 | } |
310 | ||
1da177e4 LT |
311 | module_init(linear_init); |
312 | module_exit(linear_exit); | |
313 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 314 | MODULE_DESCRIPTION("Linear device concatenation personality for MD"); |
d9d166c2 N |
315 | MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/ |
316 | MODULE_ALIAS("md-linear"); | |
2604b703 | 317 | MODULE_ALIAS("md-level--1"); |