1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 raid0.c : Multiple Devices driver for Linux
4 Copyright (C) 1994-96 Marc ZYNGIER
5 <zyngier@ufr-info-p7.ibp.fr> or
6 <maz@gloups.fdn.fr>
7 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
8
9 RAID-0 management functions.
10
11 */
12
13 #include <linux/blkdev.h>
14 #include <linux/seq_file.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <trace/events/block.h>
18 #include "md.h"
19 #include "raid0.h"
20 #include "raid5.h"
21
22 static int default_layout = 0;
23 module_param(default_layout, int, 0644);
24
25 #define UNSUPPORTED_MDDEV_FLAGS \
26 ((1L << MD_HAS_JOURNAL) | \
27 (1L << MD_JOURNAL_CLEAN) | \
28 (1L << MD_FAILFAST_SUPPORTED) |\
29 (1L << MD_HAS_PPL) | \
30 (1L << MD_HAS_MULTIPLE_PPLS))
31
32 /*
33 * inform the user of the raid configuration
34 */
dump_zones(struct mddev * mddev)35 static void dump_zones(struct mddev *mddev)
36 {
37 int j, k;
38 sector_t zone_size = 0;
39 sector_t zone_start = 0;
40 struct r0conf *conf = mddev->private;
41 int raid_disks = conf->strip_zone[0].nb_dev;
42 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
43 mdname(mddev),
44 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
45 for (j = 0; j < conf->nr_strip_zones; j++) {
46 char line[200];
47 int len = 0;
48
49 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
50 len += snprintf(line+len, 200-len, "%s%pg", k?"/":"",
51 conf->devlist[j * raid_disks + k]->bdev);
52 pr_debug("md: zone%d=[%s]\n", j, line);
53
54 zone_size = conf->strip_zone[j].zone_end - zone_start;
55 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
56 (unsigned long long)zone_start>>1,
57 (unsigned long long)conf->strip_zone[j].dev_start>>1,
58 (unsigned long long)zone_size>>1);
59 zone_start = conf->strip_zone[j].zone_end;
60 }
61 }
62
create_strip_zones(struct mddev * mddev,struct r0conf ** private_conf)63 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
64 {
65 int i, c, err;
66 sector_t curr_zone_end, sectors;
67 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
68 struct strip_zone *zone;
69 int cnt;
70 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
71 unsigned blksize = 512;
72
73 *private_conf = ERR_PTR(-ENOMEM);
74 if (!conf)
75 return -ENOMEM;
76 rdev_for_each(rdev1, mddev) {
77 pr_debug("md/raid0:%s: looking at %pg\n",
78 mdname(mddev),
79 rdev1->bdev);
80 c = 0;
81
82 /* round size to chunk_size */
83 sectors = rdev1->sectors;
84 sector_div(sectors, mddev->chunk_sectors);
85 rdev1->sectors = sectors * mddev->chunk_sectors;
86
87 blksize = max(blksize, queue_logical_block_size(
88 rdev1->bdev->bd_disk->queue));
89
90 rdev_for_each(rdev2, mddev) {
91 pr_debug("md/raid0:%s: comparing %pg(%llu)"
92 " with %pg(%llu)\n",
93 mdname(mddev),
94 rdev1->bdev,
95 (unsigned long long)rdev1->sectors,
96 rdev2->bdev,
97 (unsigned long long)rdev2->sectors);
98 if (rdev2 == rdev1) {
99 pr_debug("md/raid0:%s: END\n",
100 mdname(mddev));
101 break;
102 }
103 if (rdev2->sectors == rdev1->sectors) {
104 /*
105 * Not unique, don't count it as a new
106 * group
107 */
108 pr_debug("md/raid0:%s: EQUAL\n",
109 mdname(mddev));
110 c = 1;
111 break;
112 }
113 pr_debug("md/raid0:%s: NOT EQUAL\n",
114 mdname(mddev));
115 }
116 if (!c) {
117 pr_debug("md/raid0:%s: ==> UNIQUE\n",
118 mdname(mddev));
119 conf->nr_strip_zones++;
120 pr_debug("md/raid0:%s: %d zones\n",
121 mdname(mddev), conf->nr_strip_zones);
122 }
123 }
124 pr_debug("md/raid0:%s: FINAL %d zones\n",
125 mdname(mddev), conf->nr_strip_zones);
126
127 /*
128 * now since we have the hard sector sizes, we can make sure
129 * chunk size is a multiple of that sector size
130 */
131 if ((mddev->chunk_sectors << 9) % blksize) {
132 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
133 mdname(mddev),
134 mddev->chunk_sectors << 9, blksize);
135 err = -EINVAL;
136 goto abort;
137 }
138
139 err = -ENOMEM;
140 conf->strip_zone = kcalloc(conf->nr_strip_zones,
141 sizeof(struct strip_zone),
142 GFP_KERNEL);
143 if (!conf->strip_zone)
144 goto abort;
145 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
146 conf->nr_strip_zones,
147 mddev->raid_disks),
148 GFP_KERNEL);
149 if (!conf->devlist)
150 goto abort;
151
152 /* The first zone must contain all devices, so here we check that
153 * there is a proper alignment of slots to devices and find them all
154 */
155 zone = &conf->strip_zone[0];
156 cnt = 0;
157 smallest = NULL;
158 dev = conf->devlist;
159 err = -EINVAL;
160 rdev_for_each(rdev1, mddev) {
161 int j = rdev1->raid_disk;
162
163 if (mddev->level == 10) {
164 /* taking over a raid10-n2 array */
165 j /= 2;
166 rdev1->new_raid_disk = j;
167 }
168
169 if (mddev->level == 1) {
170 /* taiking over a raid1 array-
171 * we have only one active disk
172 */
173 j = 0;
174 rdev1->new_raid_disk = j;
175 }
176
177 if (j < 0) {
178 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
179 mdname(mddev));
180 goto abort;
181 }
182 if (j >= mddev->raid_disks) {
183 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
184 mdname(mddev), j);
185 goto abort;
186 }
187 if (dev[j]) {
188 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
189 mdname(mddev), j);
190 goto abort;
191 }
192 dev[j] = rdev1;
193
194 if (!smallest || (rdev1->sectors < smallest->sectors))
195 smallest = rdev1;
196 cnt++;
197 }
198 if (cnt != mddev->raid_disks) {
199 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
200 mdname(mddev), cnt, mddev->raid_disks);
201 goto abort;
202 }
203 zone->nb_dev = cnt;
204 zone->zone_end = smallest->sectors * cnt;
205
206 curr_zone_end = zone->zone_end;
207
208 /* now do the other zones */
209 for (i = 1; i < conf->nr_strip_zones; i++)
210 {
211 int j;
212
213 zone = conf->strip_zone + i;
214 dev = conf->devlist + i * mddev->raid_disks;
215
216 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
217 zone->dev_start = smallest->sectors;
218 smallest = NULL;
219 c = 0;
220
221 for (j=0; j<cnt; j++) {
222 rdev = conf->devlist[j];
223 if (rdev->sectors <= zone->dev_start) {
224 pr_debug("md/raid0:%s: checking %pg ... nope\n",
225 mdname(mddev),
226 rdev->bdev);
227 continue;
228 }
229 pr_debug("md/raid0:%s: checking %pg ..."
230 " contained as device %d\n",
231 mdname(mddev),
232 rdev->bdev, c);
233 dev[c] = rdev;
234 c++;
235 if (!smallest || rdev->sectors < smallest->sectors) {
236 smallest = rdev;
237 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
238 mdname(mddev),
239 (unsigned long long)rdev->sectors);
240 }
241 }
242
243 zone->nb_dev = c;
244 sectors = (smallest->sectors - zone->dev_start) * c;
245 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
246 mdname(mddev),
247 zone->nb_dev, (unsigned long long)sectors);
248
249 curr_zone_end += sectors;
250 zone->zone_end = curr_zone_end;
251
252 pr_debug("md/raid0:%s: current zone start: %llu\n",
253 mdname(mddev),
254 (unsigned long long)smallest->sectors);
255 }
256
257 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
258 conf->layout = RAID0_ORIG_LAYOUT;
259 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
260 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
261 conf->layout = mddev->layout;
262 } else if (default_layout == RAID0_ORIG_LAYOUT ||
263 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
264 conf->layout = default_layout;
265 } else {
266 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
267 mdname(mddev));
268 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
269 err = -EOPNOTSUPP;
270 goto abort;
271 }
272
273 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
274 *private_conf = conf;
275
276 return 0;
277 abort:
278 kfree(conf->strip_zone);
279 kfree(conf->devlist);
280 kfree(conf);
281 *private_conf = ERR_PTR(err);
282 return err;
283 }
284
285 /* Find the zone which holds a particular offset
286 * Update *sectorp to be an offset in that zone
287 */
find_zone(struct r0conf * conf,sector_t * sectorp)288 static struct strip_zone *find_zone(struct r0conf *conf,
289 sector_t *sectorp)
290 {
291 int i;
292 struct strip_zone *z = conf->strip_zone;
293 sector_t sector = *sectorp;
294
295 for (i = 0; i < conf->nr_strip_zones; i++)
296 if (sector < z[i].zone_end) {
297 if (i)
298 *sectorp = sector - z[i-1].zone_end;
299 return z + i;
300 }
301 BUG();
302 }
303
304 /*
305 * remaps the bio to the target device. we separate two flows.
306 * power 2 flow and a general flow for the sake of performance
307 */
map_sector(struct mddev * mddev,struct strip_zone * zone,sector_t sector,sector_t * sector_offset)308 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
309 sector_t sector, sector_t *sector_offset)
310 {
311 unsigned int sect_in_chunk;
312 sector_t chunk;
313 struct r0conf *conf = mddev->private;
314 int raid_disks = conf->strip_zone[0].nb_dev;
315 unsigned int chunk_sects = mddev->chunk_sectors;
316
317 if (is_power_of_2(chunk_sects)) {
318 int chunksect_bits = ffz(~chunk_sects);
319 /* find the sector offset inside the chunk */
320 sect_in_chunk = sector & (chunk_sects - 1);
321 sector >>= chunksect_bits;
322 /* chunk in zone */
323 chunk = *sector_offset;
324 /* quotient is the chunk in real device*/
325 sector_div(chunk, zone->nb_dev << chunksect_bits);
326 } else{
327 sect_in_chunk = sector_div(sector, chunk_sects);
328 chunk = *sector_offset;
329 sector_div(chunk, chunk_sects * zone->nb_dev);
330 }
331 /*
332 * position the bio over the real device
333 * real sector = chunk in device + starting of zone
334 * + the position in the chunk
335 */
336 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
337 return conf->devlist[(zone - conf->strip_zone)*raid_disks
338 + sector_div(sector, zone->nb_dev)];
339 }
340
raid0_size(struct mddev * mddev,sector_t sectors,int raid_disks)341 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
342 {
343 sector_t array_sectors = 0;
344 struct md_rdev *rdev;
345
346 WARN_ONCE(sectors || raid_disks,
347 "%s does not support generic reshape\n", __func__);
348
349 rdev_for_each(rdev, mddev)
350 array_sectors += (rdev->sectors &
351 ~(sector_t)(mddev->chunk_sectors-1));
352
353 return array_sectors;
354 }
355
free_conf(struct mddev * mddev,struct r0conf * conf)356 static void free_conf(struct mddev *mddev, struct r0conf *conf)
357 {
358 kfree(conf->strip_zone);
359 kfree(conf->devlist);
360 kfree(conf);
361 }
362
raid0_free(struct mddev * mddev,void * priv)363 static void raid0_free(struct mddev *mddev, void *priv)
364 {
365 struct r0conf *conf = priv;
366
367 free_conf(mddev, conf);
368 acct_bioset_exit(mddev);
369 }
370
raid0_run(struct mddev * mddev)371 static int raid0_run(struct mddev *mddev)
372 {
373 struct r0conf *conf;
374 int ret;
375
376 if (mddev->chunk_sectors == 0) {
377 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
378 return -EINVAL;
379 }
380 if (md_check_no_bitmap(mddev))
381 return -EINVAL;
382
383 if (acct_bioset_init(mddev)) {
384 pr_err("md/raid0:%s: alloc acct bioset failed.\n", mdname(mddev));
385 return -ENOMEM;
386 }
387
388 /* if private is not null, we are here after takeover */
389 if (mddev->private == NULL) {
390 ret = create_strip_zones(mddev, &conf);
391 if (ret < 0)
392 goto exit_acct_set;
393 mddev->private = conf;
394 }
395 conf = mddev->private;
396 if (mddev->queue) {
397 struct md_rdev *rdev;
398
399 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
400 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
401 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
402
403 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
404 blk_queue_io_opt(mddev->queue,
405 (mddev->chunk_sectors << 9) * mddev->raid_disks);
406
407 rdev_for_each(rdev, mddev) {
408 disk_stack_limits(mddev->gendisk, rdev->bdev,
409 rdev->data_offset << 9);
410 }
411 }
412
413 /* calculate array device size */
414 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
415
416 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
417 mdname(mddev),
418 (unsigned long long)mddev->array_sectors);
419
420 dump_zones(mddev);
421
422 ret = md_integrity_register(mddev);
423 if (ret)
424 goto free;
425
426 return ret;
427
428 free:
429 free_conf(mddev, conf);
430 exit_acct_set:
431 acct_bioset_exit(mddev);
432 return ret;
433 }
434
raid0_handle_discard(struct mddev * mddev,struct bio * bio)435 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
436 {
437 struct r0conf *conf = mddev->private;
438 struct strip_zone *zone;
439 sector_t start = bio->bi_iter.bi_sector;
440 sector_t end;
441 unsigned int stripe_size;
442 sector_t first_stripe_index, last_stripe_index;
443 sector_t start_disk_offset;
444 unsigned int start_disk_index;
445 sector_t end_disk_offset;
446 unsigned int end_disk_index;
447 unsigned int disk;
448
449 zone = find_zone(conf, &start);
450
451 if (bio_end_sector(bio) > zone->zone_end) {
452 struct bio *split = bio_split(bio,
453 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
454 &mddev->bio_set);
455 bio_chain(split, bio);
456 submit_bio_noacct(bio);
457 bio = split;
458 end = zone->zone_end;
459 } else
460 end = bio_end_sector(bio);
461
462 if (zone != conf->strip_zone)
463 end = end - zone[-1].zone_end;
464
465 /* Now start and end is the offset in zone */
466 stripe_size = zone->nb_dev * mddev->chunk_sectors;
467
468 first_stripe_index = start;
469 sector_div(first_stripe_index, stripe_size);
470 last_stripe_index = end;
471 sector_div(last_stripe_index, stripe_size);
472
473 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
474 mddev->chunk_sectors;
475 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
476 mddev->chunk_sectors) +
477 first_stripe_index * mddev->chunk_sectors;
478 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
479 mddev->chunk_sectors;
480 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
481 mddev->chunk_sectors) +
482 last_stripe_index * mddev->chunk_sectors;
483
484 for (disk = 0; disk < zone->nb_dev; disk++) {
485 sector_t dev_start, dev_end;
486 struct md_rdev *rdev;
487
488 if (disk < start_disk_index)
489 dev_start = (first_stripe_index + 1) *
490 mddev->chunk_sectors;
491 else if (disk > start_disk_index)
492 dev_start = first_stripe_index * mddev->chunk_sectors;
493 else
494 dev_start = start_disk_offset;
495
496 if (disk < end_disk_index)
497 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
498 else if (disk > end_disk_index)
499 dev_end = last_stripe_index * mddev->chunk_sectors;
500 else
501 dev_end = end_disk_offset;
502
503 if (dev_end <= dev_start)
504 continue;
505
506 rdev = conf->devlist[(zone - conf->strip_zone) *
507 conf->strip_zone[0].nb_dev + disk];
508 md_submit_discard_bio(mddev, rdev, bio,
509 dev_start + zone->dev_start + rdev->data_offset,
510 dev_end - dev_start);
511 }
512 bio_endio(bio);
513 }
514
raid0_make_request(struct mddev * mddev,struct bio * bio)515 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
516 {
517 struct r0conf *conf = mddev->private;
518 struct strip_zone *zone;
519 struct md_rdev *tmp_dev;
520 sector_t bio_sector;
521 sector_t sector;
522 sector_t orig_sector;
523 unsigned chunk_sects;
524 unsigned sectors;
525
526 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
527 && md_flush_request(mddev, bio))
528 return true;
529
530 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
531 raid0_handle_discard(mddev, bio);
532 return true;
533 }
534
535 bio_sector = bio->bi_iter.bi_sector;
536 sector = bio_sector;
537 chunk_sects = mddev->chunk_sectors;
538
539 sectors = chunk_sects -
540 (likely(is_power_of_2(chunk_sects))
541 ? (sector & (chunk_sects-1))
542 : sector_div(sector, chunk_sects));
543
544 /* Restore due to sector_div */
545 sector = bio_sector;
546
547 if (sectors < bio_sectors(bio)) {
548 struct bio *split = bio_split(bio, sectors, GFP_NOIO,
549 &mddev->bio_set);
550 bio_chain(split, bio);
551 submit_bio_noacct(bio);
552 bio = split;
553 }
554
555 if (bio->bi_pool != &mddev->bio_set)
556 md_account_bio(mddev, &bio);
557
558 orig_sector = sector;
559 zone = find_zone(mddev->private, §or);
560 switch (conf->layout) {
561 case RAID0_ORIG_LAYOUT:
562 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
563 break;
564 case RAID0_ALT_MULTIZONE_LAYOUT:
565 tmp_dev = map_sector(mddev, zone, sector, §or);
566 break;
567 default:
568 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
569 bio_io_error(bio);
570 return true;
571 }
572
573 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) {
574 bio_io_error(bio);
575 return true;
576 }
577
578 bio_set_dev(bio, tmp_dev->bdev);
579 bio->bi_iter.bi_sector = sector + zone->dev_start +
580 tmp_dev->data_offset;
581
582 if (mddev->gendisk)
583 trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
584 bio_sector);
585 mddev_check_write_zeroes(mddev, bio);
586 submit_bio_noacct(bio);
587 return true;
588 }
589
raid0_status(struct seq_file * seq,struct mddev * mddev)590 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
591 {
592 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
593 return;
594 }
595
raid0_takeover_raid45(struct mddev * mddev)596 static void *raid0_takeover_raid45(struct mddev *mddev)
597 {
598 struct md_rdev *rdev;
599 struct r0conf *priv_conf;
600
601 if (mddev->degraded != 1) {
602 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
603 mdname(mddev),
604 mddev->degraded);
605 return ERR_PTR(-EINVAL);
606 }
607
608 rdev_for_each(rdev, mddev) {
609 /* check slot number for a disk */
610 if (rdev->raid_disk == mddev->raid_disks-1) {
611 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
612 mdname(mddev));
613 return ERR_PTR(-EINVAL);
614 }
615 rdev->sectors = mddev->dev_sectors;
616 }
617
618 /* Set new parameters */
619 mddev->new_level = 0;
620 mddev->new_layout = 0;
621 mddev->new_chunk_sectors = mddev->chunk_sectors;
622 mddev->raid_disks--;
623 mddev->delta_disks = -1;
624 /* make sure it will be not marked as dirty */
625 mddev->recovery_cp = MaxSector;
626 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
627
628 create_strip_zones(mddev, &priv_conf);
629
630 return priv_conf;
631 }
632
raid0_takeover_raid10(struct mddev * mddev)633 static void *raid0_takeover_raid10(struct mddev *mddev)
634 {
635 struct r0conf *priv_conf;
636
637 /* Check layout:
638 * - far_copies must be 1
639 * - near_copies must be 2
640 * - disks number must be even
641 * - all mirrors must be already degraded
642 */
643 if (mddev->layout != ((1 << 8) + 2)) {
644 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
645 mdname(mddev),
646 mddev->layout);
647 return ERR_PTR(-EINVAL);
648 }
649 if (mddev->raid_disks & 1) {
650 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
651 mdname(mddev));
652 return ERR_PTR(-EINVAL);
653 }
654 if (mddev->degraded != (mddev->raid_disks>>1)) {
655 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
656 mdname(mddev));
657 return ERR_PTR(-EINVAL);
658 }
659
660 /* Set new parameters */
661 mddev->new_level = 0;
662 mddev->new_layout = 0;
663 mddev->new_chunk_sectors = mddev->chunk_sectors;
664 mddev->delta_disks = - mddev->raid_disks / 2;
665 mddev->raid_disks += mddev->delta_disks;
666 mddev->degraded = 0;
667 /* make sure it will be not marked as dirty */
668 mddev->recovery_cp = MaxSector;
669 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
670
671 create_strip_zones(mddev, &priv_conf);
672 return priv_conf;
673 }
674
raid0_takeover_raid1(struct mddev * mddev)675 static void *raid0_takeover_raid1(struct mddev *mddev)
676 {
677 struct r0conf *priv_conf;
678 int chunksect;
679
680 /* Check layout:
681 * - (N - 1) mirror drives must be already faulty
682 */
683 if ((mddev->raid_disks - 1) != mddev->degraded) {
684 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
685 mdname(mddev));
686 return ERR_PTR(-EINVAL);
687 }
688
689 /*
690 * a raid1 doesn't have the notion of chunk size, so
691 * figure out the largest suitable size we can use.
692 */
693 chunksect = 64 * 2; /* 64K by default */
694
695 /* The array must be an exact multiple of chunksize */
696 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
697 chunksect >>= 1;
698
699 if ((chunksect << 9) < PAGE_SIZE)
700 /* array size does not allow a suitable chunk size */
701 return ERR_PTR(-EINVAL);
702
703 /* Set new parameters */
704 mddev->new_level = 0;
705 mddev->new_layout = 0;
706 mddev->new_chunk_sectors = chunksect;
707 mddev->chunk_sectors = chunksect;
708 mddev->delta_disks = 1 - mddev->raid_disks;
709 mddev->raid_disks = 1;
710 /* make sure it will be not marked as dirty */
711 mddev->recovery_cp = MaxSector;
712 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
713
714 create_strip_zones(mddev, &priv_conf);
715 return priv_conf;
716 }
717
raid0_takeover(struct mddev * mddev)718 static void *raid0_takeover(struct mddev *mddev)
719 {
720 /* raid0 can take over:
721 * raid4 - if all data disks are active.
722 * raid5 - providing it is Raid4 layout and one disk is faulty
723 * raid10 - assuming we have all necessary active disks
724 * raid1 - with (N -1) mirror drives faulty
725 */
726
727 if (mddev->bitmap) {
728 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
729 mdname(mddev));
730 return ERR_PTR(-EBUSY);
731 }
732 if (mddev->level == 4)
733 return raid0_takeover_raid45(mddev);
734
735 if (mddev->level == 5) {
736 if (mddev->layout == ALGORITHM_PARITY_N)
737 return raid0_takeover_raid45(mddev);
738
739 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
740 mdname(mddev), ALGORITHM_PARITY_N);
741 }
742
743 if (mddev->level == 10)
744 return raid0_takeover_raid10(mddev);
745
746 if (mddev->level == 1)
747 return raid0_takeover_raid1(mddev);
748
749 pr_warn("Takeover from raid%i to raid0 not supported\n",
750 mddev->level);
751
752 return ERR_PTR(-EINVAL);
753 }
754
raid0_quiesce(struct mddev * mddev,int quiesce)755 static void raid0_quiesce(struct mddev *mddev, int quiesce)
756 {
757 }
758
759 static struct md_personality raid0_personality=
760 {
761 .name = "raid0",
762 .level = 0,
763 .owner = THIS_MODULE,
764 .make_request = raid0_make_request,
765 .run = raid0_run,
766 .free = raid0_free,
767 .status = raid0_status,
768 .size = raid0_size,
769 .takeover = raid0_takeover,
770 .quiesce = raid0_quiesce,
771 };
772
raid0_init(void)773 static int __init raid0_init (void)
774 {
775 return register_md_personality (&raid0_personality);
776 }
777
raid0_exit(void)778 static void raid0_exit (void)
779 {
780 unregister_md_personality (&raid0_personality);
781 }
782
783 module_init(raid0_init);
784 module_exit(raid0_exit);
785 MODULE_LICENSE("GPL");
786 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
787 MODULE_ALIAS("md-personality-2"); /* RAID0 */
788 MODULE_ALIAS("md-raid0");
789 MODULE_ALIAS("md-level-0");
790