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block: unify flags for struct bio and struct request
[net-next-2.6.git] / drivers / md / raid0.c
CommitLineData
1da177e4
LT
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
9 RAID-0 management functions.
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2, or (at your option)
14 any later version.
15
16 You should have received a copy of the GNU General Public License
17 (for example /usr/src/linux/COPYING); if not, write to the Free
18 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19*/
20
bff61975 21#include <linux/blkdev.h>
bff61975 22#include <linux/seq_file.h>
5a0e3ad6 23#include <linux/slab.h>
43b2e5d8 24#include "md.h"
ef740c37 25#include "raid0.h"
9af204cf 26#include "raid5.h"
1da177e4 27
165125e1 28static void raid0_unplug(struct request_queue *q)
1da177e4
LT
29{
30 mddev_t *mddev = q->queuedata;
070ec55d 31 raid0_conf_t *conf = mddev->private;
b414579f 32 mdk_rdev_t **devlist = conf->devlist;
84707f38 33 int raid_disks = conf->strip_zone[0].nb_dev;
1da177e4
LT
34 int i;
35
84707f38 36 for (i=0; i < raid_disks; i++) {
165125e1 37 struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev);
1da177e4 38
2ad8b1ef 39 blk_unplug(r_queue);
1da177e4
LT
40 }
41}
42
26be34dc
N
43static int raid0_congested(void *data, int bits)
44{
45 mddev_t *mddev = data;
070ec55d 46 raid0_conf_t *conf = mddev->private;
b414579f 47 mdk_rdev_t **devlist = conf->devlist;
84707f38 48 int raid_disks = conf->strip_zone[0].nb_dev;
26be34dc
N
49 int i, ret = 0;
50
3fa841d7
N
51 if (mddev_congested(mddev, bits))
52 return 1;
53
84707f38 54 for (i = 0; i < raid_disks && !ret ; i++) {
165125e1 55 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
26be34dc
N
56
57 ret |= bdi_congested(&q->backing_dev_info, bits);
58 }
59 return ret;
60}
61
46994191 62/*
63 * inform the user of the raid configuration
64*/
65static void dump_zones(mddev_t *mddev)
66{
67 int j, k, h;
68 sector_t zone_size = 0;
69 sector_t zone_start = 0;
70 char b[BDEVNAME_SIZE];
71 raid0_conf_t *conf = mddev->private;
84707f38 72 int raid_disks = conf->strip_zone[0].nb_dev;
46994191 73 printk(KERN_INFO "******* %s configuration *********\n",
74 mdname(mddev));
75 h = 0;
76 for (j = 0; j < conf->nr_strip_zones; j++) {
77 printk(KERN_INFO "zone%d=[", j);
78 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
b5a20961 79 printk(KERN_CONT "%s/",
84707f38 80 bdevname(conf->devlist[j*raid_disks
46994191 81 + k]->bdev, b));
b5a20961 82 printk(KERN_CONT "]\n");
46994191 83
84 zone_size = conf->strip_zone[j].zone_end - zone_start;
85 printk(KERN_INFO " zone offset=%llukb "
86 "device offset=%llukb size=%llukb\n",
87 (unsigned long long)zone_start>>1,
88 (unsigned long long)conf->strip_zone[j].dev_start>>1,
89 (unsigned long long)zone_size>>1);
90 zone_start = conf->strip_zone[j].zone_end;
91 }
92 printk(KERN_INFO "**********************************\n\n");
93}
94
9af204cf 95static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf)
1da177e4 96{
a9f326eb 97 int i, c, err;
49f357a2 98 sector_t curr_zone_end, sectors;
b414579f 99 mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev;
1da177e4
LT
100 struct strip_zone *zone;
101 int cnt;
102 char b[BDEVNAME_SIZE];
ed7b0038
AN
103 raid0_conf_t *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
104
105 if (!conf)
106 return -ENOMEM;
159ec1fc 107 list_for_each_entry(rdev1, &mddev->disks, same_set) {
b5a20961
N
108 printk(KERN_INFO "md/raid0:%s: looking at %s\n",
109 mdname(mddev),
110 bdevname(rdev1->bdev, b));
1da177e4 111 c = 0;
13f2682b
N
112
113 /* round size to chunk_size */
114 sectors = rdev1->sectors;
115 sector_div(sectors, mddev->chunk_sectors);
116 rdev1->sectors = sectors * mddev->chunk_sectors;
117
159ec1fc 118 list_for_each_entry(rdev2, &mddev->disks, same_set) {
b5a20961
N
119 printk(KERN_INFO "md/raid0:%s: comparing %s(%llu)",
120 mdname(mddev),
1da177e4 121 bdevname(rdev1->bdev,b),
dd8ac336 122 (unsigned long long)rdev1->sectors);
b5a20961 123 printk(KERN_CONT " with %s(%llu)\n",
1da177e4 124 bdevname(rdev2->bdev,b),
dd8ac336 125 (unsigned long long)rdev2->sectors);
1da177e4 126 if (rdev2 == rdev1) {
b5a20961
N
127 printk(KERN_INFO "md/raid0:%s: END\n",
128 mdname(mddev));
1da177e4
LT
129 break;
130 }
dd8ac336 131 if (rdev2->sectors == rdev1->sectors) {
1da177e4
LT
132 /*
133 * Not unique, don't count it as a new
134 * group
135 */
b5a20961
N
136 printk(KERN_INFO "md/raid0:%s: EQUAL\n",
137 mdname(mddev));
1da177e4
LT
138 c = 1;
139 break;
140 }
b5a20961
N
141 printk(KERN_INFO "md/raid0:%s: NOT EQUAL\n",
142 mdname(mddev));
1da177e4
LT
143 }
144 if (!c) {
b5a20961
N
145 printk(KERN_INFO "md/raid0:%s: ==> UNIQUE\n",
146 mdname(mddev));
1da177e4 147 conf->nr_strip_zones++;
b5a20961
N
148 printk(KERN_INFO "md/raid0:%s: %d zones\n",
149 mdname(mddev), conf->nr_strip_zones);
1da177e4
LT
150 }
151 }
b5a20961
N
152 printk(KERN_INFO "md/raid0:%s: FINAL %d zones\n",
153 mdname(mddev), conf->nr_strip_zones);
ed7b0038 154 err = -ENOMEM;
9ffae0cf 155 conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
1da177e4
LT
156 conf->nr_strip_zones, GFP_KERNEL);
157 if (!conf->strip_zone)
ed7b0038 158 goto abort;
9ffae0cf 159 conf->devlist = kzalloc(sizeof(mdk_rdev_t*)*
1da177e4
LT
160 conf->nr_strip_zones*mddev->raid_disks,
161 GFP_KERNEL);
162 if (!conf->devlist)
ed7b0038 163 goto abort;
1da177e4 164
1da177e4
LT
165 /* The first zone must contain all devices, so here we check that
166 * there is a proper alignment of slots to devices and find them all
167 */
168 zone = &conf->strip_zone[0];
169 cnt = 0;
170 smallest = NULL;
b414579f 171 dev = conf->devlist;
ed7b0038 172 err = -EINVAL;
159ec1fc 173 list_for_each_entry(rdev1, &mddev->disks, same_set) {
1da177e4
LT
174 int j = rdev1->raid_disk;
175
e93f68a1 176 if (mddev->level == 10) {
9af204cf
TM
177 /* taking over a raid10-n2 array */
178 j /= 2;
e93f68a1
N
179 rdev1->new_raid_disk = j;
180 }
9af204cf 181
1da177e4 182 if (j < 0 || j >= mddev->raid_disks) {
b5a20961
N
183 printk(KERN_ERR "md/raid0:%s: bad disk number %d - "
184 "aborting!\n", mdname(mddev), j);
1da177e4
LT
185 goto abort;
186 }
b414579f 187 if (dev[j]) {
b5a20961
N
188 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - "
189 "aborting!\n", mdname(mddev), j);
1da177e4
LT
190 goto abort;
191 }
b414579f 192 dev[j] = rdev1;
1da177e4 193
8f6c2e4b
MP
194 disk_stack_limits(mddev->gendisk, rdev1->bdev,
195 rdev1->data_offset << 9);
1da177e4 196 /* as we don't honour merge_bvec_fn, we must never risk
627a2d3c
N
197 * violating it, so limit ->max_segments to 1, lying within
198 * a single page.
1da177e4
LT
199 */
200
627a2d3c
N
201 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) {
202 blk_queue_max_segments(mddev->queue, 1);
203 blk_queue_segment_boundary(mddev->queue,
204 PAGE_CACHE_SIZE - 1);
205 }
dd8ac336 206 if (!smallest || (rdev1->sectors < smallest->sectors))
1da177e4
LT
207 smallest = rdev1;
208 cnt++;
209 }
210 if (cnt != mddev->raid_disks) {
b5a20961
N
211 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - "
212 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks);
1da177e4
LT
213 goto abort;
214 }
215 zone->nb_dev = cnt;
49f357a2 216 zone->zone_end = smallest->sectors * cnt;
1da177e4 217
49f357a2 218 curr_zone_end = zone->zone_end;
1da177e4
LT
219
220 /* now do the other zones */
221 for (i = 1; i < conf->nr_strip_zones; i++)
222 {
a9f326eb
N
223 int j;
224
1da177e4 225 zone = conf->strip_zone + i;
b414579f 226 dev = conf->devlist + i * mddev->raid_disks;
1da177e4 227
b5a20961
N
228 printk(KERN_INFO "md/raid0:%s: zone %d\n",
229 mdname(mddev), i);
d27a43ab 230 zone->dev_start = smallest->sectors;
1da177e4
LT
231 smallest = NULL;
232 c = 0;
233
234 for (j=0; j<cnt; j++) {
b414579f 235 rdev = conf->devlist[j];
b5a20961
N
236 printk(KERN_INFO "md/raid0:%s: checking %s ...",
237 mdname(mddev),
238 bdevname(rdev->bdev, b));
d27a43ab 239 if (rdev->sectors <= zone->dev_start) {
b5a20961 240 printk(KERN_CONT " nope.\n");
dd8ac336
AN
241 continue;
242 }
b5a20961 243 printk(KERN_CONT " contained as device %d\n", c);
b414579f 244 dev[c] = rdev;
dd8ac336
AN
245 c++;
246 if (!smallest || rdev->sectors < smallest->sectors) {
247 smallest = rdev;
b5a20961
N
248 printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n",
249 mdname(mddev),
250 (unsigned long long)rdev->sectors);
dd8ac336 251 }
1da177e4
LT
252 }
253
254 zone->nb_dev = c;
49f357a2 255 sectors = (smallest->sectors - zone->dev_start) * c;
b5a20961
N
256 printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
257 mdname(mddev),
258 zone->nb_dev, (unsigned long long)sectors);
1da177e4 259
49f357a2 260 curr_zone_end += sectors;
d27a43ab 261 zone->zone_end = curr_zone_end;
1da177e4 262
b5a20961
N
263 printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n",
264 mdname(mddev),
265 (unsigned long long)smallest->sectors);
1da177e4 266 }
1da177e4 267 mddev->queue->unplug_fn = raid0_unplug;
26be34dc
N
268 mddev->queue->backing_dev_info.congested_fn = raid0_congested;
269 mddev->queue->backing_dev_info.congested_data = mddev;
1da177e4 270
92e59b6b 271 /*
272 * now since we have the hard sector sizes, we can make sure
273 * chunk size is a multiple of that sector size
274 */
9d8f0363 275 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) {
b5a20961 276 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n",
92e59b6b 277 mdname(mddev),
9d8f0363 278 mddev->chunk_sectors << 9);
92e59b6b 279 goto abort;
280 }
8f6c2e4b
MP
281
282 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
283 blk_queue_io_opt(mddev->queue,
284 (mddev->chunk_sectors << 9) * mddev->raid_disks);
285
b5a20961 286 printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev));
9af204cf
TM
287 *private_conf = conf;
288
1da177e4 289 return 0;
5568a603 290abort:
ed7b0038
AN
291 kfree(conf->strip_zone);
292 kfree(conf->devlist);
293 kfree(conf);
9af204cf 294 *private_conf = NULL;
ed7b0038 295 return err;
1da177e4
LT
296}
297
298/**
299 * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged
300 * @q: request queue
cc371e66 301 * @bvm: properties of new bio
1da177e4
LT
302 * @biovec: the request that could be merged to it.
303 *
304 * Return amount of bytes we can accept at this offset
305 */
cc371e66
AK
306static int raid0_mergeable_bvec(struct request_queue *q,
307 struct bvec_merge_data *bvm,
308 struct bio_vec *biovec)
1da177e4
LT
309{
310 mddev_t *mddev = q->queuedata;
cc371e66 311 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
1da177e4 312 int max;
9d8f0363 313 unsigned int chunk_sectors = mddev->chunk_sectors;
cc371e66 314 unsigned int bio_sectors = bvm->bi_size >> 9;
1da177e4 315
d6e412ea 316 if (is_power_of_2(chunk_sectors))
fbb704ef 317 max = (chunk_sectors - ((sector & (chunk_sectors-1))
318 + bio_sectors)) << 9;
319 else
320 max = (chunk_sectors - (sector_div(sector, chunk_sectors)
321 + bio_sectors)) << 9;
1da177e4
LT
322 if (max < 0) max = 0; /* bio_add cannot handle a negative return */
323 if (max <= biovec->bv_len && bio_sectors == 0)
324 return biovec->bv_len;
325 else
326 return max;
327}
328
80c3a6ce
DW
329static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks)
330{
331 sector_t array_sectors = 0;
332 mdk_rdev_t *rdev;
333
334 WARN_ONCE(sectors || raid_disks,
335 "%s does not support generic reshape\n", __func__);
336
337 list_for_each_entry(rdev, &mddev->disks, same_set)
338 array_sectors += rdev->sectors;
339
340 return array_sectors;
341}
342
8f79cfcd 343static int raid0_run(mddev_t *mddev)
1da177e4 344{
9af204cf 345 raid0_conf_t *conf;
5568a603 346 int ret;
1da177e4 347
9d8f0363 348 if (mddev->chunk_sectors == 0) {
b5a20961
N
349 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n",
350 mdname(mddev));
2604b703
N
351 return -EINVAL;
352 }
0894cc30
AN
353 if (md_check_no_bitmap(mddev))
354 return -EINVAL;
086fa5ff 355 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
e7e72bf6 356 mddev->queue->queue_lock = &mddev->queue->__queue_lock;
1da177e4 357
9af204cf
TM
358 /* if private is not null, we are here after takeover */
359 if (mddev->private == NULL) {
360 ret = create_strip_zones(mddev, &conf);
361 if (ret < 0)
362 return ret;
363 mddev->private = conf;
364 }
365 conf = mddev->private;
1da177e4
LT
366
367 /* calculate array device size */
1f403624 368 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
1da177e4 369
b5a20961
N
370 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n",
371 mdname(mddev),
372 (unsigned long long)mddev->array_sectors);
1da177e4
LT
373 /* calculate the max read-ahead size.
374 * For read-ahead of large files to be effective, we need to
375 * readahead at least twice a whole stripe. i.e. number of devices
376 * multiplied by chunk size times 2.
377 * If an individual device has an ra_pages greater than the
378 * chunk size, then we will not drive that device as hard as it
379 * wants. We consider this a configuration error: a larger
380 * chunksize should be used in that case.
381 */
382 {
9d8f0363
AN
383 int stripe = mddev->raid_disks *
384 (mddev->chunk_sectors << 9) / PAGE_SIZE;
1da177e4
LT
385 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
386 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
387 }
388
1da177e4 389 blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec);
46994191 390 dump_zones(mddev);
ac5e7113 391 md_integrity_register(mddev);
1da177e4 392 return 0;
1da177e4
LT
393}
394
fb5ab4b5 395static int raid0_stop(mddev_t *mddev)
1da177e4 396{
070ec55d 397 raid0_conf_t *conf = mddev->private;
1da177e4
LT
398
399 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
990a8baf 400 kfree(conf->strip_zone);
fb5ab4b5 401 kfree(conf->devlist);
990a8baf 402 kfree(conf);
1da177e4 403 mddev->private = NULL;
1da177e4
LT
404 return 0;
405}
406
49f357a2
N
407/* Find the zone which holds a particular offset
408 * Update *sectorp to be an offset in that zone
409 */
dc582663 410static struct strip_zone *find_zone(struct raid0_private_data *conf,
49f357a2 411 sector_t *sectorp)
dc582663
AN
412{
413 int i;
414 struct strip_zone *z = conf->strip_zone;
49f357a2 415 sector_t sector = *sectorp;
dc582663
AN
416
417 for (i = 0; i < conf->nr_strip_zones; i++)
49f357a2
N
418 if (sector < z[i].zone_end) {
419 if (i)
420 *sectorp = sector - z[i-1].zone_end;
dc582663 421 return z + i;
49f357a2 422 }
dc582663
AN
423 BUG();
424}
425
fbb704ef 426/*
427 * remaps the bio to the target device. we separate two flows.
428 * power 2 flow and a general flow for the sake of perfromance
429*/
430static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone,
431 sector_t sector, sector_t *sector_offset)
1da177e4 432{
fbb704ef 433 unsigned int sect_in_chunk;
434 sector_t chunk;
070ec55d 435 raid0_conf_t *conf = mddev->private;
84707f38 436 int raid_disks = conf->strip_zone[0].nb_dev;
9d8f0363 437 unsigned int chunk_sects = mddev->chunk_sectors;
fbb704ef 438
d6e412ea 439 if (is_power_of_2(chunk_sects)) {
fbb704ef 440 int chunksect_bits = ffz(~chunk_sects);
441 /* find the sector offset inside the chunk */
442 sect_in_chunk = sector & (chunk_sects - 1);
443 sector >>= chunksect_bits;
444 /* chunk in zone */
445 chunk = *sector_offset;
446 /* quotient is the chunk in real device*/
447 sector_div(chunk, zone->nb_dev << chunksect_bits);
448 } else{
449 sect_in_chunk = sector_div(sector, chunk_sects);
450 chunk = *sector_offset;
451 sector_div(chunk, chunk_sects * zone->nb_dev);
452 }
453 /*
454 * position the bio over the real device
455 * real sector = chunk in device + starting of zone
456 * + the position in the chunk
457 */
458 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
84707f38 459 return conf->devlist[(zone - conf->strip_zone)*raid_disks
fbb704ef 460 + sector_div(sector, zone->nb_dev)];
461}
462
463/*
464 * Is io distribute over 1 or more chunks ?
465*/
466static inline int is_io_in_chunk_boundary(mddev_t *mddev,
467 unsigned int chunk_sects, struct bio *bio)
468{
d6e412ea 469 if (likely(is_power_of_2(chunk_sects))) {
fbb704ef 470 return chunk_sects >= ((bio->bi_sector & (chunk_sects-1))
471 + (bio->bi_size >> 9));
472 } else{
473 sector_t sector = bio->bi_sector;
474 return chunk_sects >= (sector_div(sector, chunk_sects)
475 + (bio->bi_size >> 9));
476 }
477}
478
21a52c6d 479static int raid0_make_request(mddev_t *mddev, struct bio *bio)
fbb704ef 480{
fbb704ef 481 unsigned int chunk_sects;
482 sector_t sector_offset;
1da177e4
LT
483 struct strip_zone *zone;
484 mdk_rdev_t *tmp_dev;
1da177e4 485
7b6d91da 486 if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
a2826aa9 487 md_barrier_request(mddev, bio);
e5dcdd80
N
488 return 0;
489 }
490
9d8f0363 491 chunk_sects = mddev->chunk_sectors;
fbb704ef 492 if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) {
493 sector_t sector = bio->bi_sector;
1da177e4
LT
494 struct bio_pair *bp;
495 /* Sanity check -- queue functions should prevent this happening */
496 if (bio->bi_vcnt != 1 ||
497 bio->bi_idx != 0)
498 goto bad_map;
499 /* This is a one page bio that upper layers
500 * refuse to split for us, so we need to split it.
501 */
d6e412ea 502 if (likely(is_power_of_2(chunk_sects)))
fbb704ef 503 bp = bio_split(bio, chunk_sects - (sector &
504 (chunk_sects-1)));
505 else
506 bp = bio_split(bio, chunk_sects -
507 sector_div(sector, chunk_sects));
21a52c6d 508 if (raid0_make_request(mddev, &bp->bio1))
1da177e4 509 generic_make_request(&bp->bio1);
21a52c6d 510 if (raid0_make_request(mddev, &bp->bio2))
1da177e4
LT
511 generic_make_request(&bp->bio2);
512
513 bio_pair_release(bp);
514 return 0;
515 }
1da177e4 516
fbb704ef 517 sector_offset = bio->bi_sector;
518 zone = find_zone(mddev->private, &sector_offset);
519 tmp_dev = map_sector(mddev, zone, bio->bi_sector,
520 &sector_offset);
1da177e4 521 bio->bi_bdev = tmp_dev->bdev;
fbb704ef 522 bio->bi_sector = sector_offset + zone->dev_start +
523 tmp_dev->data_offset;
1da177e4
LT
524 /*
525 * Let the main block layer submit the IO and resolve recursion:
526 */
527 return 1;
528
529bad_map:
b5a20961
N
530 printk("md/raid0:%s: make_request bug: can't convert block across chunks"
531 " or bigger than %dk %llu %d\n",
532 mdname(mddev), chunk_sects / 2,
533 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
1da177e4 534
6712ecf8 535 bio_io_error(bio);
1da177e4
LT
536 return 0;
537}
8299d7f7 538
1b961429 539static void raid0_status(struct seq_file *seq, mddev_t *mddev)
1da177e4
LT
540{
541#undef MD_DEBUG
542#ifdef MD_DEBUG
543 int j, k, h;
544 char b[BDEVNAME_SIZE];
070ec55d 545 raid0_conf_t *conf = mddev->private;
84707f38 546 int raid_disks = conf->strip_zone[0].nb_dev;
8299d7f7 547
1b961429 548 sector_t zone_size;
549 sector_t zone_start = 0;
1da177e4 550 h = 0;
1b961429 551
1da177e4
LT
552 for (j = 0; j < conf->nr_strip_zones; j++) {
553 seq_printf(seq, " z%d", j);
1da177e4
LT
554 seq_printf(seq, "=[");
555 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
8299d7f7 556 seq_printf(seq, "%s/", bdevname(
84707f38 557 conf->devlist[j*raid_disks + k]
1b961429 558 ->bdev, b));
559
560 zone_size = conf->strip_zone[j].zone_end - zone_start;
561 seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n",
562 (unsigned long long)zone_start>>1,
563 (unsigned long long)conf->strip_zone[j].dev_start>>1,
564 (unsigned long long)zone_size>>1);
565 zone_start = conf->strip_zone[j].zone_end;
1da177e4
LT
566 }
567#endif
9d8f0363 568 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
1da177e4
LT
569 return;
570}
571
049d6c1e 572static void *raid0_takeover_raid45(mddev_t *mddev)
9af204cf
TM
573{
574 mdk_rdev_t *rdev;
575 raid0_conf_t *priv_conf;
576
577 if (mddev->degraded != 1) {
b5a20961
N
578 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
579 mdname(mddev),
9af204cf
TM
580 mddev->degraded);
581 return ERR_PTR(-EINVAL);
582 }
583
584 list_for_each_entry(rdev, &mddev->disks, same_set) {
585 /* check slot number for a disk */
586 if (rdev->raid_disk == mddev->raid_disks-1) {
b5a20961
N
587 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n",
588 mdname(mddev));
9af204cf
TM
589 return ERR_PTR(-EINVAL);
590 }
591 }
592
593 /* Set new parameters */
594 mddev->new_level = 0;
001048a3 595 mddev->new_layout = 0;
9af204cf
TM
596 mddev->new_chunk_sectors = mddev->chunk_sectors;
597 mddev->raid_disks--;
598 mddev->delta_disks = -1;
599 /* make sure it will be not marked as dirty */
600 mddev->recovery_cp = MaxSector;
601
602 create_strip_zones(mddev, &priv_conf);
603 return priv_conf;
604}
605
606static void *raid0_takeover_raid10(mddev_t *mddev)
607{
608 raid0_conf_t *priv_conf;
609
610 /* Check layout:
611 * - far_copies must be 1
612 * - near_copies must be 2
613 * - disks number must be even
614 * - all mirrors must be already degraded
615 */
616 if (mddev->layout != ((1 << 8) + 2)) {
b5a20961
N
617 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n",
618 mdname(mddev),
9af204cf
TM
619 mddev->layout);
620 return ERR_PTR(-EINVAL);
621 }
622 if (mddev->raid_disks & 1) {
b5a20961
N
623 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n",
624 mdname(mddev));
9af204cf
TM
625 return ERR_PTR(-EINVAL);
626 }
627 if (mddev->degraded != (mddev->raid_disks>>1)) {
b5a20961
N
628 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n",
629 mdname(mddev));
9af204cf
TM
630 return ERR_PTR(-EINVAL);
631 }
632
633 /* Set new parameters */
634 mddev->new_level = 0;
001048a3 635 mddev->new_layout = 0;
9af204cf
TM
636 mddev->new_chunk_sectors = mddev->chunk_sectors;
637 mddev->delta_disks = - mddev->raid_disks / 2;
638 mddev->raid_disks += mddev->delta_disks;
639 mddev->degraded = 0;
640 /* make sure it will be not marked as dirty */
641 mddev->recovery_cp = MaxSector;
642
643 create_strip_zones(mddev, &priv_conf);
9af204cf
TM
644 return priv_conf;
645}
646
647static void *raid0_takeover(mddev_t *mddev)
648{
649 /* raid0 can take over:
049d6c1e 650 * raid4 - if all data disks are active.
9af204cf
TM
651 * raid5 - providing it is Raid4 layout and one disk is faulty
652 * raid10 - assuming we have all necessary active disks
653 */
049d6c1e
MT
654 if (mddev->level == 4)
655 return raid0_takeover_raid45(mddev);
656
9af204cf
TM
657 if (mddev->level == 5) {
658 if (mddev->layout == ALGORITHM_PARITY_N)
049d6c1e 659 return raid0_takeover_raid45(mddev);
9af204cf 660
b5a20961
N
661 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
662 mdname(mddev), ALGORITHM_PARITY_N);
9af204cf
TM
663 }
664
665 if (mddev->level == 10)
666 return raid0_takeover_raid10(mddev);
667
668 return ERR_PTR(-EINVAL);
669}
670
671static void raid0_quiesce(mddev_t *mddev, int state)
672{
673}
674
2604b703 675static struct mdk_personality raid0_personality=
1da177e4
LT
676{
677 .name = "raid0",
2604b703 678 .level = 0,
1da177e4
LT
679 .owner = THIS_MODULE,
680 .make_request = raid0_make_request,
681 .run = raid0_run,
682 .stop = raid0_stop,
683 .status = raid0_status,
80c3a6ce 684 .size = raid0_size,
9af204cf
TM
685 .takeover = raid0_takeover,
686 .quiesce = raid0_quiesce,
1da177e4
LT
687};
688
689static int __init raid0_init (void)
690{
2604b703 691 return register_md_personality (&raid0_personality);
1da177e4
LT
692}
693
694static void raid0_exit (void)
695{
2604b703 696 unregister_md_personality (&raid0_personality);
1da177e4
LT
697}
698
699module_init(raid0_init);
700module_exit(raid0_exit);
701MODULE_LICENSE("GPL");
0efb9e61 702MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
1da177e4 703MODULE_ALIAS("md-personality-2"); /* RAID0 */
d9d166c2 704MODULE_ALIAS("md-raid0");
2604b703 705MODULE_ALIAS("md-level-0");