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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
22static int default_layout = 0;
23module_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*/
35static void dump_zones(struct mddev *mddev)
36{
37 int j, k;
38 sector_t zone_size = 0;
39 sector_t zone_start = 0;
40 char b[BDEVNAME_SIZE];
41 struct r0conf *conf = mddev->private;
42 int raid_disks = conf->strip_zone[0].nb_dev;
43 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
44 mdname(mddev),
45 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
46 for (j = 0; j < conf->nr_strip_zones; j++) {
47 char line[200];
48 int len = 0;
49
50 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
51 len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
52 bdevname(conf->devlist[j*raid_disks
53 + k]->bdev, b));
54 pr_debug("md: zone%d=[%s]\n", j, line);
55
56 zone_size = conf->strip_zone[j].zone_end - zone_start;
57 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
58 (unsigned long long)zone_start>>1,
59 (unsigned long long)conf->strip_zone[j].dev_start>>1,
60 (unsigned long long)zone_size>>1);
61 zone_start = conf->strip_zone[j].zone_end;
62 }
63}
64
65static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
66{
67 int i, c, err;
68 sector_t curr_zone_end, sectors;
69 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
70 struct strip_zone *zone;
71 int cnt;
72 char b[BDEVNAME_SIZE];
73 char b2[BDEVNAME_SIZE];
74 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
75 unsigned blksize = 512;
76
77 *private_conf = ERR_PTR(-ENOMEM);
78 if (!conf)
79 return -ENOMEM;
80 rdev_for_each(rdev1, mddev) {
81 pr_debug("md/raid0:%s: looking at %s\n",
82 mdname(mddev),
83 bdevname(rdev1->bdev, b));
84 c = 0;
85
86 /* round size to chunk_size */
87 sectors = rdev1->sectors;
88 sector_div(sectors, mddev->chunk_sectors);
89 rdev1->sectors = sectors * mddev->chunk_sectors;
90
91 blksize = max(blksize, queue_logical_block_size(
92 rdev1->bdev->bd_disk->queue));
93
94 rdev_for_each(rdev2, mddev) {
95 pr_debug("md/raid0:%s: comparing %s(%llu)"
96 " with %s(%llu)\n",
97 mdname(mddev),
98 bdevname(rdev1->bdev,b),
99 (unsigned long long)rdev1->sectors,
100 bdevname(rdev2->bdev,b2),
101 (unsigned long long)rdev2->sectors);
102 if (rdev2 == rdev1) {
103 pr_debug("md/raid0:%s: END\n",
104 mdname(mddev));
105 break;
106 }
107 if (rdev2->sectors == rdev1->sectors) {
108 /*
109 * Not unique, don't count it as a new
110 * group
111 */
112 pr_debug("md/raid0:%s: EQUAL\n",
113 mdname(mddev));
114 c = 1;
115 break;
116 }
117 pr_debug("md/raid0:%s: NOT EQUAL\n",
118 mdname(mddev));
119 }
120 if (!c) {
121 pr_debug("md/raid0:%s: ==> UNIQUE\n",
122 mdname(mddev));
123 conf->nr_strip_zones++;
124 pr_debug("md/raid0:%s: %d zones\n",
125 mdname(mddev), conf->nr_strip_zones);
126 }
127 }
128 pr_debug("md/raid0:%s: FINAL %d zones\n",
129 mdname(mddev), conf->nr_strip_zones);
130
131 if (conf->nr_strip_zones == 1) {
132 conf->layout = RAID0_ORIG_LAYOUT;
133 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
134 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
135 conf->layout = mddev->layout;
136 } else if (default_layout == RAID0_ORIG_LAYOUT ||
137 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
138 conf->layout = default_layout;
139 } else {
140 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
141 mdname(mddev));
142 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
143 err = -ENOTSUPP;
144 goto abort;
145 }
146 /*
147 * now since we have the hard sector sizes, we can make sure
148 * chunk size is a multiple of that sector size
149 */
150 if ((mddev->chunk_sectors << 9) % blksize) {
151 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
152 mdname(mddev),
153 mddev->chunk_sectors << 9, blksize);
154 err = -EINVAL;
155 goto abort;
156 }
157
158 err = -ENOMEM;
159 conf->strip_zone = kcalloc(conf->nr_strip_zones,
160 sizeof(struct strip_zone),
161 GFP_KERNEL);
162 if (!conf->strip_zone)
163 goto abort;
164 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
165 conf->nr_strip_zones,
166 mddev->raid_disks),
167 GFP_KERNEL);
168 if (!conf->devlist)
169 goto abort;
170
171 /* The first zone must contain all devices, so here we check that
172 * there is a proper alignment of slots to devices and find them all
173 */
174 zone = &conf->strip_zone[0];
175 cnt = 0;
176 smallest = NULL;
177 dev = conf->devlist;
178 err = -EINVAL;
179 rdev_for_each(rdev1, mddev) {
180 int j = rdev1->raid_disk;
181
182 if (mddev->level == 10) {
183 /* taking over a raid10-n2 array */
184 j /= 2;
185 rdev1->new_raid_disk = j;
186 }
187
188 if (mddev->level == 1) {
189 /* taiking over a raid1 array-
190 * we have only one active disk
191 */
192 j = 0;
193 rdev1->new_raid_disk = j;
194 }
195
196 if (j < 0) {
197 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
198 mdname(mddev));
199 goto abort;
200 }
201 if (j >= mddev->raid_disks) {
202 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
203 mdname(mddev), j);
204 goto abort;
205 }
206 if (dev[j]) {
207 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
208 mdname(mddev), j);
209 goto abort;
210 }
211 dev[j] = rdev1;
212
213 if (!smallest || (rdev1->sectors < smallest->sectors))
214 smallest = rdev1;
215 cnt++;
216 }
217 if (cnt != mddev->raid_disks) {
218 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
219 mdname(mddev), cnt, mddev->raid_disks);
220 goto abort;
221 }
222 zone->nb_dev = cnt;
223 zone->zone_end = smallest->sectors * cnt;
224
225 curr_zone_end = zone->zone_end;
226
227 /* now do the other zones */
228 for (i = 1; i < conf->nr_strip_zones; i++)
229 {
230 int j;
231
232 zone = conf->strip_zone + i;
233 dev = conf->devlist + i * mddev->raid_disks;
234
235 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
236 zone->dev_start = smallest->sectors;
237 smallest = NULL;
238 c = 0;
239
240 for (j=0; j<cnt; j++) {
241 rdev = conf->devlist[j];
242 if (rdev->sectors <= zone->dev_start) {
243 pr_debug("md/raid0:%s: checking %s ... nope\n",
244 mdname(mddev),
245 bdevname(rdev->bdev, b));
246 continue;
247 }
248 pr_debug("md/raid0:%s: checking %s ..."
249 " contained as device %d\n",
250 mdname(mddev),
251 bdevname(rdev->bdev, b), c);
252 dev[c] = rdev;
253 c++;
254 if (!smallest || rdev->sectors < smallest->sectors) {
255 smallest = rdev;
256 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
257 mdname(mddev),
258 (unsigned long long)rdev->sectors);
259 }
260 }
261
262 zone->nb_dev = c;
263 sectors = (smallest->sectors - zone->dev_start) * c;
264 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
265 mdname(mddev),
266 zone->nb_dev, (unsigned long long)sectors);
267
268 curr_zone_end += sectors;
269 zone->zone_end = curr_zone_end;
270
271 pr_debug("md/raid0:%s: current zone start: %llu\n",
272 mdname(mddev),
273 (unsigned long long)smallest->sectors);
274 }
275
276 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
277 *private_conf = conf;
278
279 return 0;
280abort:
281 kfree(conf->strip_zone);
282 kfree(conf->devlist);
283 kfree(conf);
284 *private_conf = ERR_PTR(err);
285 return err;
286}
287
288/* Find the zone which holds a particular offset
289 * Update *sectorp to be an offset in that zone
290 */
291static struct strip_zone *find_zone(struct r0conf *conf,
292 sector_t *sectorp)
293{
294 int i;
295 struct strip_zone *z = conf->strip_zone;
296 sector_t sector = *sectorp;
297
298 for (i = 0; i < conf->nr_strip_zones; i++)
299 if (sector < z[i].zone_end) {
300 if (i)
301 *sectorp = sector - z[i-1].zone_end;
302 return z + i;
303 }
304 BUG();
305}
306
307/*
308 * remaps the bio to the target device. we separate two flows.
309 * power 2 flow and a general flow for the sake of performance
310*/
311static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
312 sector_t sector, sector_t *sector_offset)
313{
314 unsigned int sect_in_chunk;
315 sector_t chunk;
316 struct r0conf *conf = mddev->private;
317 int raid_disks = conf->strip_zone[0].nb_dev;
318 unsigned int chunk_sects = mddev->chunk_sectors;
319
320 if (is_power_of_2(chunk_sects)) {
321 int chunksect_bits = ffz(~chunk_sects);
322 /* find the sector offset inside the chunk */
323 sect_in_chunk = sector & (chunk_sects - 1);
324 sector >>= chunksect_bits;
325 /* chunk in zone */
326 chunk = *sector_offset;
327 /* quotient is the chunk in real device*/
328 sector_div(chunk, zone->nb_dev << chunksect_bits);
329 } else{
330 sect_in_chunk = sector_div(sector, chunk_sects);
331 chunk = *sector_offset;
332 sector_div(chunk, chunk_sects * zone->nb_dev);
333 }
334 /*
335 * position the bio over the real device
336 * real sector = chunk in device + starting of zone
337 * + the position in the chunk
338 */
339 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
340 return conf->devlist[(zone - conf->strip_zone)*raid_disks
341 + sector_div(sector, zone->nb_dev)];
342}
343
344static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
345{
346 sector_t array_sectors = 0;
347 struct md_rdev *rdev;
348
349 WARN_ONCE(sectors || raid_disks,
350 "%s does not support generic reshape\n", __func__);
351
352 rdev_for_each(rdev, mddev)
353 array_sectors += (rdev->sectors &
354 ~(sector_t)(mddev->chunk_sectors-1));
355
356 return array_sectors;
357}
358
359static void raid0_free(struct mddev *mddev, void *priv);
360
361static int raid0_run(struct mddev *mddev)
362{
363 struct r0conf *conf;
364 int ret;
365
366 if (mddev->chunk_sectors == 0) {
367 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
368 return -EINVAL;
369 }
370 if (md_check_no_bitmap(mddev))
371 return -EINVAL;
372
373 /* if private is not null, we are here after takeover */
374 if (mddev->private == NULL) {
375 ret = create_strip_zones(mddev, &conf);
376 if (ret < 0)
377 return ret;
378 mddev->private = conf;
379 }
380 conf = mddev->private;
381 if (mddev->queue) {
382 struct md_rdev *rdev;
383 bool discard_supported = false;
384
385 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
386 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
387 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
388 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
389
390 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
391 blk_queue_io_opt(mddev->queue,
392 (mddev->chunk_sectors << 9) * mddev->raid_disks);
393
394 rdev_for_each(rdev, mddev) {
395 disk_stack_limits(mddev->gendisk, rdev->bdev,
396 rdev->data_offset << 9);
397 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
398 discard_supported = true;
399 }
400 if (!discard_supported)
401 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue);
402 else
403 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
404 }
405
406 /* calculate array device size */
407 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
408
409 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
410 mdname(mddev),
411 (unsigned long long)mddev->array_sectors);
412
413 if (mddev->queue) {
414 /* calculate the max read-ahead size.
415 * For read-ahead of large files to be effective, we need to
416 * readahead at least twice a whole stripe. i.e. number of devices
417 * multiplied by chunk size times 2.
418 * If an individual device has an ra_pages greater than the
419 * chunk size, then we will not drive that device as hard as it
420 * wants. We consider this a configuration error: a larger
421 * chunksize should be used in that case.
422 */
423 int stripe = mddev->raid_disks *
424 (mddev->chunk_sectors << 9) / PAGE_SIZE;
425 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
426 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
427 }
428
429 dump_zones(mddev);
430
431 ret = md_integrity_register(mddev);
432
433 return ret;
434}
435
436static void raid0_free(struct mddev *mddev, void *priv)
437{
438 struct r0conf *conf = priv;
439
440 kfree(conf->strip_zone);
441 kfree(conf->devlist);
442 kfree(conf);
443}
444
445/*
446 * Is io distribute over 1 or more chunks ?
447*/
448static inline int is_io_in_chunk_boundary(struct mddev *mddev,
449 unsigned int chunk_sects, struct bio *bio)
450{
451 if (likely(is_power_of_2(chunk_sects))) {
452 return chunk_sects >=
453 ((bio->bi_iter.bi_sector & (chunk_sects-1))
454 + bio_sectors(bio));
455 } else{
456 sector_t sector = bio->bi_iter.bi_sector;
457 return chunk_sects >= (sector_div(sector, chunk_sects)
458 + bio_sectors(bio));
459 }
460}
461
462static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
463{
464 struct r0conf *conf = mddev->private;
465 struct strip_zone *zone;
466 sector_t start = bio->bi_iter.bi_sector;
467 sector_t end;
468 unsigned int stripe_size;
469 sector_t first_stripe_index, last_stripe_index;
470 sector_t start_disk_offset;
471 unsigned int start_disk_index;
472 sector_t end_disk_offset;
473 unsigned int end_disk_index;
474 unsigned int disk;
475
476 zone = find_zone(conf, &start);
477
478 if (bio_end_sector(bio) > zone->zone_end) {
479 struct bio *split = bio_split(bio,
480 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
481 &mddev->bio_set);
482 bio_chain(split, bio);
483 submit_bio_noacct(bio);
484 bio = split;
485 end = zone->zone_end;
486 } else
487 end = bio_end_sector(bio);
488
489 if (zone != conf->strip_zone)
490 end = end - zone[-1].zone_end;
491
492 /* Now start and end is the offset in zone */
493 stripe_size = zone->nb_dev * mddev->chunk_sectors;
494
495 first_stripe_index = start;
496 sector_div(first_stripe_index, stripe_size);
497 last_stripe_index = end;
498 sector_div(last_stripe_index, stripe_size);
499
500 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
501 mddev->chunk_sectors;
502 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
503 mddev->chunk_sectors) +
504 first_stripe_index * mddev->chunk_sectors;
505 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
506 mddev->chunk_sectors;
507 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
508 mddev->chunk_sectors) +
509 last_stripe_index * mddev->chunk_sectors;
510
511 for (disk = 0; disk < zone->nb_dev; disk++) {
512 sector_t dev_start, dev_end;
513 struct bio *discard_bio = NULL;
514 struct md_rdev *rdev;
515
516 if (disk < start_disk_index)
517 dev_start = (first_stripe_index + 1) *
518 mddev->chunk_sectors;
519 else if (disk > start_disk_index)
520 dev_start = first_stripe_index * mddev->chunk_sectors;
521 else
522 dev_start = start_disk_offset;
523
524 if (disk < end_disk_index)
525 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
526 else if (disk > end_disk_index)
527 dev_end = last_stripe_index * mddev->chunk_sectors;
528 else
529 dev_end = end_disk_offset;
530
531 if (dev_end <= dev_start)
532 continue;
533
534 rdev = conf->devlist[(zone - conf->strip_zone) *
535 conf->strip_zone[0].nb_dev + disk];
536 if (__blkdev_issue_discard(rdev->bdev,
537 dev_start + zone->dev_start + rdev->data_offset,
538 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
539 !discard_bio)
540 continue;
541 bio_chain(discard_bio, bio);
542 bio_clone_blkg_association(discard_bio, bio);
543 if (mddev->gendisk)
544 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
545 discard_bio, disk_devt(mddev->gendisk),
546 bio->bi_iter.bi_sector);
547 submit_bio_noacct(discard_bio);
548 }
549 bio_endio(bio);
550}
551
552static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
553{
554 struct r0conf *conf = mddev->private;
555 struct strip_zone *zone;
556 struct md_rdev *tmp_dev;
557 sector_t bio_sector;
558 sector_t sector;
559 sector_t orig_sector;
560 unsigned chunk_sects;
561 unsigned sectors;
562
563 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
564 && md_flush_request(mddev, bio))
565 return true;
566
567 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
568 raid0_handle_discard(mddev, bio);
569 return true;
570 }
571
572 bio_sector = bio->bi_iter.bi_sector;
573 sector = bio_sector;
574 chunk_sects = mddev->chunk_sectors;
575
576 sectors = chunk_sects -
577 (likely(is_power_of_2(chunk_sects))
578 ? (sector & (chunk_sects-1))
579 : sector_div(sector, chunk_sects));
580
581 /* Restore due to sector_div */
582 sector = bio_sector;
583
584 if (sectors < bio_sectors(bio)) {
585 struct bio *split = bio_split(bio, sectors, GFP_NOIO,
586 &mddev->bio_set);
587 bio_chain(split, bio);
588 submit_bio_noacct(bio);
589 bio = split;
590 }
591
592 orig_sector = sector;
593 zone = find_zone(mddev->private, §or);
594 switch (conf->layout) {
595 case RAID0_ORIG_LAYOUT:
596 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
597 break;
598 case RAID0_ALT_MULTIZONE_LAYOUT:
599 tmp_dev = map_sector(mddev, zone, sector, §or);
600 break;
601 default:
602 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
603 bio_io_error(bio);
604 return true;
605 }
606
607 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) {
608 bio_io_error(bio);
609 return true;
610 }
611
612 bio_set_dev(bio, tmp_dev->bdev);
613 bio->bi_iter.bi_sector = sector + zone->dev_start +
614 tmp_dev->data_offset;
615
616 if (mddev->gendisk)
617 trace_block_bio_remap(bio->bi_disk->queue, bio,
618 disk_devt(mddev->gendisk), bio_sector);
619 mddev_check_writesame(mddev, bio);
620 mddev_check_write_zeroes(mddev, bio);
621 submit_bio_noacct(bio);
622 return true;
623}
624
625static void raid0_status(struct seq_file *seq, struct mddev *mddev)
626{
627 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
628 return;
629}
630
631static void *raid0_takeover_raid45(struct mddev *mddev)
632{
633 struct md_rdev *rdev;
634 struct r0conf *priv_conf;
635
636 if (mddev->degraded != 1) {
637 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
638 mdname(mddev),
639 mddev->degraded);
640 return ERR_PTR(-EINVAL);
641 }
642
643 rdev_for_each(rdev, mddev) {
644 /* check slot number for a disk */
645 if (rdev->raid_disk == mddev->raid_disks-1) {
646 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
647 mdname(mddev));
648 return ERR_PTR(-EINVAL);
649 }
650 rdev->sectors = mddev->dev_sectors;
651 }
652
653 /* Set new parameters */
654 mddev->new_level = 0;
655 mddev->new_layout = 0;
656 mddev->new_chunk_sectors = mddev->chunk_sectors;
657 mddev->raid_disks--;
658 mddev->delta_disks = -1;
659 /* make sure it will be not marked as dirty */
660 mddev->recovery_cp = MaxSector;
661 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
662
663 create_strip_zones(mddev, &priv_conf);
664
665 return priv_conf;
666}
667
668static void *raid0_takeover_raid10(struct mddev *mddev)
669{
670 struct r0conf *priv_conf;
671
672 /* Check layout:
673 * - far_copies must be 1
674 * - near_copies must be 2
675 * - disks number must be even
676 * - all mirrors must be already degraded
677 */
678 if (mddev->layout != ((1 << 8) + 2)) {
679 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
680 mdname(mddev),
681 mddev->layout);
682 return ERR_PTR(-EINVAL);
683 }
684 if (mddev->raid_disks & 1) {
685 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
686 mdname(mddev));
687 return ERR_PTR(-EINVAL);
688 }
689 if (mddev->degraded != (mddev->raid_disks>>1)) {
690 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
691 mdname(mddev));
692 return ERR_PTR(-EINVAL);
693 }
694
695 /* Set new parameters */
696 mddev->new_level = 0;
697 mddev->new_layout = 0;
698 mddev->new_chunk_sectors = mddev->chunk_sectors;
699 mddev->delta_disks = - mddev->raid_disks / 2;
700 mddev->raid_disks += mddev->delta_disks;
701 mddev->degraded = 0;
702 /* make sure it will be not marked as dirty */
703 mddev->recovery_cp = MaxSector;
704 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
705
706 create_strip_zones(mddev, &priv_conf);
707 return priv_conf;
708}
709
710static void *raid0_takeover_raid1(struct mddev *mddev)
711{
712 struct r0conf *priv_conf;
713 int chunksect;
714
715 /* Check layout:
716 * - (N - 1) mirror drives must be already faulty
717 */
718 if ((mddev->raid_disks - 1) != mddev->degraded) {
719 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
720 mdname(mddev));
721 return ERR_PTR(-EINVAL);
722 }
723
724 /*
725 * a raid1 doesn't have the notion of chunk size, so
726 * figure out the largest suitable size we can use.
727 */
728 chunksect = 64 * 2; /* 64K by default */
729
730 /* The array must be an exact multiple of chunksize */
731 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
732 chunksect >>= 1;
733
734 if ((chunksect << 9) < PAGE_SIZE)
735 /* array size does not allow a suitable chunk size */
736 return ERR_PTR(-EINVAL);
737
738 /* Set new parameters */
739 mddev->new_level = 0;
740 mddev->new_layout = 0;
741 mddev->new_chunk_sectors = chunksect;
742 mddev->chunk_sectors = chunksect;
743 mddev->delta_disks = 1 - mddev->raid_disks;
744 mddev->raid_disks = 1;
745 /* make sure it will be not marked as dirty */
746 mddev->recovery_cp = MaxSector;
747 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
748
749 create_strip_zones(mddev, &priv_conf);
750 return priv_conf;
751}
752
753static void *raid0_takeover(struct mddev *mddev)
754{
755 /* raid0 can take over:
756 * raid4 - if all data disks are active.
757 * raid5 - providing it is Raid4 layout and one disk is faulty
758 * raid10 - assuming we have all necessary active disks
759 * raid1 - with (N -1) mirror drives faulty
760 */
761
762 if (mddev->bitmap) {
763 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
764 mdname(mddev));
765 return ERR_PTR(-EBUSY);
766 }
767 if (mddev->level == 4)
768 return raid0_takeover_raid45(mddev);
769
770 if (mddev->level == 5) {
771 if (mddev->layout == ALGORITHM_PARITY_N)
772 return raid0_takeover_raid45(mddev);
773
774 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
775 mdname(mddev), ALGORITHM_PARITY_N);
776 }
777
778 if (mddev->level == 10)
779 return raid0_takeover_raid10(mddev);
780
781 if (mddev->level == 1)
782 return raid0_takeover_raid1(mddev);
783
784 pr_warn("Takeover from raid%i to raid0 not supported\n",
785 mddev->level);
786
787 return ERR_PTR(-EINVAL);
788}
789
790static void raid0_quiesce(struct mddev *mddev, int quiesce)
791{
792}
793
794static struct md_personality raid0_personality=
795{
796 .name = "raid0",
797 .level = 0,
798 .owner = THIS_MODULE,
799 .make_request = raid0_make_request,
800 .run = raid0_run,
801 .free = raid0_free,
802 .status = raid0_status,
803 .size = raid0_size,
804 .takeover = raid0_takeover,
805 .quiesce = raid0_quiesce,
806};
807
808static int __init raid0_init (void)
809{
810 return register_md_personality (&raid0_personality);
811}
812
813static void raid0_exit (void)
814{
815 unregister_md_personality (&raid0_personality);
816}
817
818module_init(raid0_init);
819module_exit(raid0_exit);
820MODULE_LICENSE("GPL");
821MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
822MODULE_ALIAS("md-personality-2"); /* RAID0 */
823MODULE_ALIAS("md-raid0");
824MODULE_ALIAS("md-level-0");
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
22static int default_layout = 0;
23module_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*/
35static 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 += scnprintf(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
63static 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;
277abort:
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 */
288static 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*/
308static 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
341static 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
356static void free_conf(struct mddev *mddev, struct r0conf *conf)
357{
358 kfree(conf->strip_zone);
359 kfree(conf->devlist);
360 kfree(conf);
361}
362
363static 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
371static 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
402 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
403 blk_queue_io_opt(mddev->queue,
404 (mddev->chunk_sectors << 9) * mddev->raid_disks);
405
406 rdev_for_each(rdev, mddev) {
407 disk_stack_limits(mddev->gendisk, rdev->bdev,
408 rdev->data_offset << 9);
409 }
410 }
411
412 /* calculate array device size */
413 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
414
415 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
416 mdname(mddev),
417 (unsigned long long)mddev->array_sectors);
418
419 dump_zones(mddev);
420
421 ret = md_integrity_register(mddev);
422 if (ret)
423 goto free;
424
425 return ret;
426
427free:
428 free_conf(mddev, conf);
429exit_acct_set:
430 acct_bioset_exit(mddev);
431 return ret;
432}
433
434static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
435{
436 struct r0conf *conf = mddev->private;
437 struct strip_zone *zone;
438 sector_t start = bio->bi_iter.bi_sector;
439 sector_t end;
440 unsigned int stripe_size;
441 sector_t first_stripe_index, last_stripe_index;
442 sector_t start_disk_offset;
443 unsigned int start_disk_index;
444 sector_t end_disk_offset;
445 unsigned int end_disk_index;
446 unsigned int disk;
447
448 zone = find_zone(conf, &start);
449
450 if (bio_end_sector(bio) > zone->zone_end) {
451 struct bio *split = bio_split(bio,
452 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
453 &mddev->bio_set);
454 bio_chain(split, bio);
455 submit_bio_noacct(bio);
456 bio = split;
457 end = zone->zone_end;
458 } else
459 end = bio_end_sector(bio);
460
461 if (zone != conf->strip_zone)
462 end = end - zone[-1].zone_end;
463
464 /* Now start and end is the offset in zone */
465 stripe_size = zone->nb_dev * mddev->chunk_sectors;
466
467 first_stripe_index = start;
468 sector_div(first_stripe_index, stripe_size);
469 last_stripe_index = end;
470 sector_div(last_stripe_index, stripe_size);
471
472 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
473 mddev->chunk_sectors;
474 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
475 mddev->chunk_sectors) +
476 first_stripe_index * mddev->chunk_sectors;
477 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
478 mddev->chunk_sectors;
479 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
480 mddev->chunk_sectors) +
481 last_stripe_index * mddev->chunk_sectors;
482
483 for (disk = 0; disk < zone->nb_dev; disk++) {
484 sector_t dev_start, dev_end;
485 struct md_rdev *rdev;
486
487 if (disk < start_disk_index)
488 dev_start = (first_stripe_index + 1) *
489 mddev->chunk_sectors;
490 else if (disk > start_disk_index)
491 dev_start = first_stripe_index * mddev->chunk_sectors;
492 else
493 dev_start = start_disk_offset;
494
495 if (disk < end_disk_index)
496 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
497 else if (disk > end_disk_index)
498 dev_end = last_stripe_index * mddev->chunk_sectors;
499 else
500 dev_end = end_disk_offset;
501
502 if (dev_end <= dev_start)
503 continue;
504
505 rdev = conf->devlist[(zone - conf->strip_zone) *
506 conf->strip_zone[0].nb_dev + disk];
507 md_submit_discard_bio(mddev, rdev, bio,
508 dev_start + zone->dev_start + rdev->data_offset,
509 dev_end - dev_start);
510 }
511 bio_endio(bio);
512}
513
514static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
515{
516 struct r0conf *conf = mddev->private;
517 struct strip_zone *zone;
518 struct md_rdev *tmp_dev;
519 sector_t bio_sector;
520 sector_t sector;
521 sector_t orig_sector;
522 unsigned chunk_sects;
523 unsigned sectors;
524
525 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
526 && md_flush_request(mddev, bio))
527 return true;
528
529 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
530 raid0_handle_discard(mddev, bio);
531 return true;
532 }
533
534 bio_sector = bio->bi_iter.bi_sector;
535 sector = bio_sector;
536 chunk_sects = mddev->chunk_sectors;
537
538 sectors = chunk_sects -
539 (likely(is_power_of_2(chunk_sects))
540 ? (sector & (chunk_sects-1))
541 : sector_div(sector, chunk_sects));
542
543 /* Restore due to sector_div */
544 sector = bio_sector;
545
546 if (sectors < bio_sectors(bio)) {
547 struct bio *split = bio_split(bio, sectors, GFP_NOIO,
548 &mddev->bio_set);
549 bio_chain(split, bio);
550 submit_bio_noacct(bio);
551 bio = split;
552 }
553
554 if (bio->bi_pool != &mddev->bio_set)
555 md_account_bio(mddev, &bio);
556
557 orig_sector = sector;
558 zone = find_zone(mddev->private, §or);
559 switch (conf->layout) {
560 case RAID0_ORIG_LAYOUT:
561 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
562 break;
563 case RAID0_ALT_MULTIZONE_LAYOUT:
564 tmp_dev = map_sector(mddev, zone, sector, §or);
565 break;
566 default:
567 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
568 bio_io_error(bio);
569 return true;
570 }
571
572 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) {
573 bio_io_error(bio);
574 return true;
575 }
576
577 bio_set_dev(bio, tmp_dev->bdev);
578 bio->bi_iter.bi_sector = sector + zone->dev_start +
579 tmp_dev->data_offset;
580
581 if (mddev->gendisk)
582 trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
583 bio_sector);
584 mddev_check_write_zeroes(mddev, bio);
585 submit_bio_noacct(bio);
586 return true;
587}
588
589static void raid0_status(struct seq_file *seq, struct mddev *mddev)
590{
591 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
592 return;
593}
594
595static void *raid0_takeover_raid45(struct mddev *mddev)
596{
597 struct md_rdev *rdev;
598 struct r0conf *priv_conf;
599
600 if (mddev->degraded != 1) {
601 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
602 mdname(mddev),
603 mddev->degraded);
604 return ERR_PTR(-EINVAL);
605 }
606
607 rdev_for_each(rdev, mddev) {
608 /* check slot number for a disk */
609 if (rdev->raid_disk == mddev->raid_disks-1) {
610 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
611 mdname(mddev));
612 return ERR_PTR(-EINVAL);
613 }
614 rdev->sectors = mddev->dev_sectors;
615 }
616
617 /* Set new parameters */
618 mddev->new_level = 0;
619 mddev->new_layout = 0;
620 mddev->new_chunk_sectors = mddev->chunk_sectors;
621 mddev->raid_disks--;
622 mddev->delta_disks = -1;
623 /* make sure it will be not marked as dirty */
624 mddev->recovery_cp = MaxSector;
625 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
626
627 create_strip_zones(mddev, &priv_conf);
628
629 return priv_conf;
630}
631
632static void *raid0_takeover_raid10(struct mddev *mddev)
633{
634 struct r0conf *priv_conf;
635
636 /* Check layout:
637 * - far_copies must be 1
638 * - near_copies must be 2
639 * - disks number must be even
640 * - all mirrors must be already degraded
641 */
642 if (mddev->layout != ((1 << 8) + 2)) {
643 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
644 mdname(mddev),
645 mddev->layout);
646 return ERR_PTR(-EINVAL);
647 }
648 if (mddev->raid_disks & 1) {
649 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
650 mdname(mddev));
651 return ERR_PTR(-EINVAL);
652 }
653 if (mddev->degraded != (mddev->raid_disks>>1)) {
654 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
655 mdname(mddev));
656 return ERR_PTR(-EINVAL);
657 }
658
659 /* Set new parameters */
660 mddev->new_level = 0;
661 mddev->new_layout = 0;
662 mddev->new_chunk_sectors = mddev->chunk_sectors;
663 mddev->delta_disks = - mddev->raid_disks / 2;
664 mddev->raid_disks += mddev->delta_disks;
665 mddev->degraded = 0;
666 /* make sure it will be not marked as dirty */
667 mddev->recovery_cp = MaxSector;
668 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
669
670 create_strip_zones(mddev, &priv_conf);
671 return priv_conf;
672}
673
674static void *raid0_takeover_raid1(struct mddev *mddev)
675{
676 struct r0conf *priv_conf;
677 int chunksect;
678
679 /* Check layout:
680 * - (N - 1) mirror drives must be already faulty
681 */
682 if ((mddev->raid_disks - 1) != mddev->degraded) {
683 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
684 mdname(mddev));
685 return ERR_PTR(-EINVAL);
686 }
687
688 /*
689 * a raid1 doesn't have the notion of chunk size, so
690 * figure out the largest suitable size we can use.
691 */
692 chunksect = 64 * 2; /* 64K by default */
693
694 /* The array must be an exact multiple of chunksize */
695 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
696 chunksect >>= 1;
697
698 if ((chunksect << 9) < PAGE_SIZE)
699 /* array size does not allow a suitable chunk size */
700 return ERR_PTR(-EINVAL);
701
702 /* Set new parameters */
703 mddev->new_level = 0;
704 mddev->new_layout = 0;
705 mddev->new_chunk_sectors = chunksect;
706 mddev->chunk_sectors = chunksect;
707 mddev->delta_disks = 1 - mddev->raid_disks;
708 mddev->raid_disks = 1;
709 /* make sure it will be not marked as dirty */
710 mddev->recovery_cp = MaxSector;
711 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
712
713 create_strip_zones(mddev, &priv_conf);
714 return priv_conf;
715}
716
717static void *raid0_takeover(struct mddev *mddev)
718{
719 /* raid0 can take over:
720 * raid4 - if all data disks are active.
721 * raid5 - providing it is Raid4 layout and one disk is faulty
722 * raid10 - assuming we have all necessary active disks
723 * raid1 - with (N -1) mirror drives faulty
724 */
725
726 if (mddev->bitmap) {
727 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
728 mdname(mddev));
729 return ERR_PTR(-EBUSY);
730 }
731 if (mddev->level == 4)
732 return raid0_takeover_raid45(mddev);
733
734 if (mddev->level == 5) {
735 if (mddev->layout == ALGORITHM_PARITY_N)
736 return raid0_takeover_raid45(mddev);
737
738 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
739 mdname(mddev), ALGORITHM_PARITY_N);
740 }
741
742 if (mddev->level == 10)
743 return raid0_takeover_raid10(mddev);
744
745 if (mddev->level == 1)
746 return raid0_takeover_raid1(mddev);
747
748 pr_warn("Takeover from raid%i to raid0 not supported\n",
749 mddev->level);
750
751 return ERR_PTR(-EINVAL);
752}
753
754static void raid0_quiesce(struct mddev *mddev, int quiesce)
755{
756}
757
758static struct md_personality raid0_personality=
759{
760 .name = "raid0",
761 .level = 0,
762 .owner = THIS_MODULE,
763 .make_request = raid0_make_request,
764 .run = raid0_run,
765 .free = raid0_free,
766 .status = raid0_status,
767 .size = raid0_size,
768 .takeover = raid0_takeover,
769 .quiesce = raid0_quiesce,
770};
771
772static int __init raid0_init (void)
773{
774 return register_md_personality (&raid0_personality);
775}
776
777static void raid0_exit (void)
778{
779 unregister_md_personality (&raid0_personality);
780}
781
782module_init(raid0_init);
783module_exit(raid0_exit);
784MODULE_LICENSE("GPL");
785MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
786MODULE_ALIAS("md-personality-2"); /* RAID0 */
787MODULE_ALIAS("md-raid0");
788MODULE_ALIAS("md-level-0");