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hwmon: (adt7475) fan stall prevention
[linux/fpc-iii.git] / drivers / md / raid0.c
blobd6c0bc76e837dff8636253f4daaea0aa16ce4d89
1 /*
2 raid0.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 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
7
8 RAID-0 management functions.
9
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
13 any later version.
14
15 You should have received a copy of the GNU General Public License
16 (for example /usr/src/linux/COPYING); if not, write to the Free
17 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20 #include <linux/blkdev.h>
21 #include <linux/seq_file.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <trace/events/block.h>
25 #include "md.h"
26 #include "raid0.h"
27 #include "raid5.h"
28
29 #define UNSUPPORTED_MDDEV_FLAGS \
30 ((1L << MD_HAS_JOURNAL) | \
31 (1L << MD_JOURNAL_CLEAN) | \
32 (1L << MD_FAILFAST_SUPPORTED) |\
33 (1L << MD_HAS_PPL))
34
35 static int raid0_congested(struct mddev *mddev, int bits)
36 {
37 struct r0conf *conf = mddev->private;
38 struct md_rdev **devlist = conf->devlist;
39 int raid_disks = conf->strip_zone[0].nb_dev;
40 int i, ret = 0;
41
42 for (i = 0; i < raid_disks && !ret ; i++) {
43 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
44
45 ret |= bdi_congested(q->backing_dev_info, bits);
46 }
47 return ret;
48 }
49
50 /*
51 * inform the user of the raid configuration
52 */
53 static void dump_zones(struct mddev *mddev)
54 {
55 int j, k;
56 sector_t zone_size = 0;
57 sector_t zone_start = 0;
58 char b[BDEVNAME_SIZE];
59 struct r0conf *conf = mddev->private;
60 int raid_disks = conf->strip_zone[0].nb_dev;
61 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
62 mdname(mddev),
63 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
64 for (j = 0; j < conf->nr_strip_zones; j++) {
65 char line[200];
66 int len = 0;
67
68 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
69 len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
70 bdevname(conf->devlist[j*raid_disks
71 + k]->bdev, b));
72 pr_debug("md: zone%d=[%s]\n", j, line);
73
74 zone_size = conf->strip_zone[j].zone_end - zone_start;
75 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
76 (unsigned long long)zone_start>>1,
77 (unsigned long long)conf->strip_zone[j].dev_start>>1,
78 (unsigned long long)zone_size>>1);
79 zone_start = conf->strip_zone[j].zone_end;
80 }
81 }
82
83 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
84 {
85 int i, c, err;
86 sector_t curr_zone_end, sectors;
87 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
88 struct strip_zone *zone;
89 int cnt;
90 char b[BDEVNAME_SIZE];
91 char b2[BDEVNAME_SIZE];
92 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
93 unsigned short blksize = 512;
94
95 *private_conf = ERR_PTR(-ENOMEM);
96 if (!conf)
97 return -ENOMEM;
98 rdev_for_each(rdev1, mddev) {
99 pr_debug("md/raid0:%s: looking at %s\n",
100 mdname(mddev),
101 bdevname(rdev1->bdev, b));
102 c = 0;
103
104 /* round size to chunk_size */
105 sectors = rdev1->sectors;
106 sector_div(sectors, mddev->chunk_sectors);
107 rdev1->sectors = sectors * mddev->chunk_sectors;
108
109 blksize = max(blksize, queue_logical_block_size(
110 rdev1->bdev->bd_disk->queue));
111
112 rdev_for_each(rdev2, mddev) {
113 pr_debug("md/raid0:%s: comparing %s(%llu)"
114 " with %s(%llu)\n",
115 mdname(mddev),
116 bdevname(rdev1->bdev,b),
117 (unsigned long long)rdev1->sectors,
118 bdevname(rdev2->bdev,b2),
119 (unsigned long long)rdev2->sectors);
120 if (rdev2 == rdev1) {
121 pr_debug("md/raid0:%s: END\n",
122 mdname(mddev));
123 break;
124 }
125 if (rdev2->sectors == rdev1->sectors) {
126 /*
127 * Not unique, don't count it as a new
128 * group
129 */
130 pr_debug("md/raid0:%s: EQUAL\n",
131 mdname(mddev));
132 c = 1;
133 break;
134 }
135 pr_debug("md/raid0:%s: NOT EQUAL\n",
136 mdname(mddev));
137 }
138 if (!c) {
139 pr_debug("md/raid0:%s: ==> UNIQUE\n",
140 mdname(mddev));
141 conf->nr_strip_zones++;
142 pr_debug("md/raid0:%s: %d zones\n",
143 mdname(mddev), conf->nr_strip_zones);
144 }
145 }
146 pr_debug("md/raid0:%s: FINAL %d zones\n",
147 mdname(mddev), conf->nr_strip_zones);
148 /*
149 * now since we have the hard sector sizes, we can make sure
150 * chunk size is a multiple of that sector size
151 */
152 if ((mddev->chunk_sectors << 9) % blksize) {
153 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
154 mdname(mddev),
155 mddev->chunk_sectors << 9, blksize);
156 err = -EINVAL;
157 goto abort;
158 }
159
160 err = -ENOMEM;
161 conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
162 conf->nr_strip_zones, GFP_KERNEL);
163 if (!conf->strip_zone)
164 goto abort;
165 conf->devlist = kzalloc(sizeof(struct md_rdev*)*
166 conf->nr_strip_zones*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;
280 abort:
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 */
291 static 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 */
311 static 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
344 static 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
359 static void raid0_free(struct mddev *mddev, void *priv);
360
361 static 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 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
402 else
403 queue_flag_set_unlocked(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
436 static 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 */
448 static 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
462 static 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 generic_make_request(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 if (mddev->gendisk)
543 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
544 discard_bio, disk_devt(mddev->gendisk),
545 bio->bi_iter.bi_sector);
546 generic_make_request(discard_bio);
547 }
548 bio_endio(bio);
549 }
550
551 static void raid0_make_request(struct mddev *mddev, struct bio *bio)
552 {
553 struct strip_zone *zone;
554 struct md_rdev *tmp_dev;
555 sector_t bio_sector;
556 sector_t sector;
557 unsigned chunk_sects;
558 unsigned sectors;
559
560 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
561 md_flush_request(mddev, bio);
562 return;
563 }
564
565 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
566 raid0_handle_discard(mddev, bio);
567 return;
568 }
569
570 bio_sector = bio->bi_iter.bi_sector;
571 sector = bio_sector;
572 chunk_sects = mddev->chunk_sectors;
573
574 sectors = chunk_sects -
575 (likely(is_power_of_2(chunk_sects))
576 ? (sector & (chunk_sects-1))
577 : sector_div(sector, chunk_sects));
578
579 /* Restore due to sector_div */
580 sector = bio_sector;
581
582 if (sectors < bio_sectors(bio)) {
583 struct bio *split = bio_split(bio, sectors, GFP_NOIO, mddev->bio_set);
584 bio_chain(split, bio);
585 generic_make_request(bio);
586 bio = split;
587 }
588
589 zone = find_zone(mddev->private, &sector);
590 tmp_dev = map_sector(mddev, zone, sector, &sector);
591 bio->bi_bdev = tmp_dev->bdev;
592 bio->bi_iter.bi_sector = sector + zone->dev_start +
593 tmp_dev->data_offset;
594
595 if (mddev->gendisk)
596 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
597 bio, disk_devt(mddev->gendisk),
598 bio_sector);
599 mddev_check_writesame(mddev, bio);
600 mddev_check_write_zeroes(mddev, bio);
601 generic_make_request(bio);
602 }
603
604 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
605 {
606 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
607 return;
608 }
609
610 static void *raid0_takeover_raid45(struct mddev *mddev)
611 {
612 struct md_rdev *rdev;
613 struct r0conf *priv_conf;
614
615 if (mddev->degraded != 1) {
616 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
617 mdname(mddev),
618 mddev->degraded);
619 return ERR_PTR(-EINVAL);
620 }
621
622 rdev_for_each(rdev, mddev) {
623 /* check slot number for a disk */
624 if (rdev->raid_disk == mddev->raid_disks-1) {
625 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
626 mdname(mddev));
627 return ERR_PTR(-EINVAL);
628 }
629 rdev->sectors = mddev->dev_sectors;
630 }
631
632 /* Set new parameters */
633 mddev->new_level = 0;
634 mddev->new_layout = 0;
635 mddev->new_chunk_sectors = mddev->chunk_sectors;
636 mddev->raid_disks--;
637 mddev->delta_disks = -1;
638 /* make sure it will be not marked as dirty */
639 mddev->recovery_cp = MaxSector;
640 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
641
642 create_strip_zones(mddev, &priv_conf);
643
644 return priv_conf;
645 }
646
647 static void *raid0_takeover_raid10(struct mddev *mddev)
648 {
649 struct r0conf *priv_conf;
650
651 /* Check layout:
652 * - far_copies must be 1
653 * - near_copies must be 2
654 * - disks number must be even
655 * - all mirrors must be already degraded
656 */
657 if (mddev->layout != ((1 << 8) + 2)) {
658 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
659 mdname(mddev),
660 mddev->layout);
661 return ERR_PTR(-EINVAL);
662 }
663 if (mddev->raid_disks & 1) {
664 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
665 mdname(mddev));
666 return ERR_PTR(-EINVAL);
667 }
668 if (mddev->degraded != (mddev->raid_disks>>1)) {
669 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
670 mdname(mddev));
671 return ERR_PTR(-EINVAL);
672 }
673
674 /* Set new parameters */
675 mddev->new_level = 0;
676 mddev->new_layout = 0;
677 mddev->new_chunk_sectors = mddev->chunk_sectors;
678 mddev->delta_disks = - mddev->raid_disks / 2;
679 mddev->raid_disks += mddev->delta_disks;
680 mddev->degraded = 0;
681 /* make sure it will be not marked as dirty */
682 mddev->recovery_cp = MaxSector;
683 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
684
685 create_strip_zones(mddev, &priv_conf);
686 return priv_conf;
687 }
688
689 static void *raid0_takeover_raid1(struct mddev *mddev)
690 {
691 struct r0conf *priv_conf;
692 int chunksect;
693
694 /* Check layout:
695 * - (N - 1) mirror drives must be already faulty
696 */
697 if ((mddev->raid_disks - 1) != mddev->degraded) {
698 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
699 mdname(mddev));
700 return ERR_PTR(-EINVAL);
701 }
702
703 /*
704 * a raid1 doesn't have the notion of chunk size, so
705 * figure out the largest suitable size we can use.
706 */
707 chunksect = 64 * 2; /* 64K by default */
708
709 /* The array must be an exact multiple of chunksize */
710 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
711 chunksect >>= 1;
712
713 if ((chunksect << 9) < PAGE_SIZE)
714 /* array size does not allow a suitable chunk size */
715 return ERR_PTR(-EINVAL);
716
717 /* Set new parameters */
718 mddev->new_level = 0;
719 mddev->new_layout = 0;
720 mddev->new_chunk_sectors = chunksect;
721 mddev->chunk_sectors = chunksect;
722 mddev->delta_disks = 1 - mddev->raid_disks;
723 mddev->raid_disks = 1;
724 /* make sure it will be not marked as dirty */
725 mddev->recovery_cp = MaxSector;
726 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
727
728 create_strip_zones(mddev, &priv_conf);
729 return priv_conf;
730 }
731
732 static void *raid0_takeover(struct mddev *mddev)
733 {
734 /* raid0 can take over:
735 * raid4 - if all data disks are active.
736 * raid5 - providing it is Raid4 layout and one disk is faulty
737 * raid10 - assuming we have all necessary active disks
738 * raid1 - with (N -1) mirror drives faulty
739 */
740
741 if (mddev->bitmap) {
742 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
743 mdname(mddev));
744 return ERR_PTR(-EBUSY);
745 }
746 if (mddev->level == 4)
747 return raid0_takeover_raid45(mddev);
748
749 if (mddev->level == 5) {
750 if (mddev->layout == ALGORITHM_PARITY_N)
751 return raid0_takeover_raid45(mddev);
752
753 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
754 mdname(mddev), ALGORITHM_PARITY_N);
755 }
756
757 if (mddev->level == 10)
758 return raid0_takeover_raid10(mddev);
759
760 if (mddev->level == 1)
761 return raid0_takeover_raid1(mddev);
762
763 pr_warn("Takeover from raid%i to raid0 not supported\n",
764 mddev->level);
765
766 return ERR_PTR(-EINVAL);
767 }
768
769 static void raid0_quiesce(struct mddev *mddev, int state)
770 {
771 }
772
773 static struct md_personality raid0_personality=
774 {
775 .name = "raid0",
776 .level = 0,
777 .owner = THIS_MODULE,
778 .make_request = raid0_make_request,
779 .run = raid0_run,
780 .free = raid0_free,
781 .status = raid0_status,
782 .size = raid0_size,
783 .takeover = raid0_takeover,
784 .quiesce = raid0_quiesce,
785 .congested = raid0_congested,
786 };
787
788 static int __init raid0_init (void)
789 {
790 return register_md_personality (&raid0_personality);
791 }
792
793 static void raid0_exit (void)
794 {
795 unregister_md_personality (&raid0_personality);
796 }
797
798 module_init(raid0_init);
799 module_exit(raid0_exit);
800 MODULE_LICENSE("GPL");
801 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
802 MODULE_ALIAS("md-personality-2"); /* RAID0 */
803 MODULE_ALIAS("md-raid0");
804 MODULE_ALIAS("md-level-0");
Linux with added FPC-III support