blob: 7492d6033ac634250c74f84e9e66273f83ff06b6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * raid10.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 2000-2004 Neil Brown
5 *
6 * RAID-10 support for md.
7 *
8 * Base on code in raid1.c. See raid1.c for futher copyright information.
9 *
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
NeilBrown6cce3b22006-01-06 00:20:16 -080021#include "dm-bio-list.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/raid/raid10.h>
NeilBrown6cce3b22006-01-06 00:20:16 -080023#include <linux/raid/bitmap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25/*
26 * RAID10 provides a combination of RAID0 and RAID1 functionality.
27 * The layout of data is defined by
28 * chunk_size
29 * raid_disks
30 * near_copies (stored in low byte of layout)
31 * far_copies (stored in second byte of layout)
NeilBrownc93983b2006-06-26 00:27:41 -070032 * far_offset (stored in bit 16 of layout )
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 *
34 * The data to be stored is divided into chunks using chunksize.
35 * Each device is divided into far_copies sections.
36 * In each section, chunks are laid out in a style similar to raid0, but
37 * near_copies copies of each chunk is stored (each on a different drive).
38 * The starting device for each section is offset near_copies from the starting
39 * device of the previous section.
NeilBrownc93983b2006-06-26 00:27:41 -070040 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 * drive.
42 * near_copies and far_copies must be at least one, and their product is at most
43 * raid_disks.
NeilBrownc93983b2006-06-26 00:27:41 -070044 *
45 * If far_offset is true, then the far_copies are handled a bit differently.
46 * The copies are still in different stripes, but instead of be very far apart
47 * on disk, there are adjacent stripes.
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 */
49
50/*
51 * Number of guaranteed r10bios in case of extreme VM load:
52 */
53#define NR_RAID10_BIOS 256
54
55static void unplug_slaves(mddev_t *mddev);
56
NeilBrown0a27ec92006-01-06 00:20:13 -080057static void allow_barrier(conf_t *conf);
58static void lower_barrier(conf_t *conf);
59
Al Virodd0fc662005-10-07 07:46:04 +010060static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070061{
62 conf_t *conf = data;
63 r10bio_t *r10_bio;
64 int size = offsetof(struct r10bio_s, devs[conf->copies]);
65
66 /* allocate a r10bio with room for raid_disks entries in the bios array */
NeilBrown9ffae0c2006-01-06 00:20:32 -080067 r10_bio = kzalloc(size, gfp_flags);
68 if (!r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 unplug_slaves(conf->mddev);
70
71 return r10_bio;
72}
73
74static void r10bio_pool_free(void *r10_bio, void *data)
75{
76 kfree(r10_bio);
77}
78
79#define RESYNC_BLOCK_SIZE (64*1024)
80//#define RESYNC_BLOCK_SIZE PAGE_SIZE
81#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
82#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
83#define RESYNC_WINDOW (2048*1024)
84
85/*
86 * When performing a resync, we need to read and compare, so
87 * we need as many pages are there are copies.
88 * When performing a recovery, we need 2 bios, one for read,
89 * one for write (we recover only one drive per r10buf)
90 *
91 */
Al Virodd0fc662005-10-07 07:46:04 +010092static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
94 conf_t *conf = data;
95 struct page *page;
96 r10bio_t *r10_bio;
97 struct bio *bio;
98 int i, j;
99 int nalloc;
100
101 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
102 if (!r10_bio) {
103 unplug_slaves(conf->mddev);
104 return NULL;
105 }
106
107 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
108 nalloc = conf->copies; /* resync */
109 else
110 nalloc = 2; /* recovery */
111
112 /*
113 * Allocate bios.
114 */
115 for (j = nalloc ; j-- ; ) {
116 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
117 if (!bio)
118 goto out_free_bio;
119 r10_bio->devs[j].bio = bio;
120 }
121 /*
122 * Allocate RESYNC_PAGES data pages and attach them
123 * where needed.
124 */
125 for (j = 0 ; j < nalloc; j++) {
126 bio = r10_bio->devs[j].bio;
127 for (i = 0; i < RESYNC_PAGES; i++) {
128 page = alloc_page(gfp_flags);
129 if (unlikely(!page))
130 goto out_free_pages;
131
132 bio->bi_io_vec[i].bv_page = page;
133 }
134 }
135
136 return r10_bio;
137
138out_free_pages:
139 for ( ; i > 0 ; i--)
NeilBrown1345b1d2006-01-06 00:20:40 -0800140 safe_put_page(bio->bi_io_vec[i-1].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 while (j--)
142 for (i = 0; i < RESYNC_PAGES ; i++)
NeilBrown1345b1d2006-01-06 00:20:40 -0800143 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 j = -1;
145out_free_bio:
146 while ( ++j < nalloc )
147 bio_put(r10_bio->devs[j].bio);
148 r10bio_pool_free(r10_bio, conf);
149 return NULL;
150}
151
152static void r10buf_pool_free(void *__r10_bio, void *data)
153{
154 int i;
155 conf_t *conf = data;
156 r10bio_t *r10bio = __r10_bio;
157 int j;
158
159 for (j=0; j < conf->copies; j++) {
160 struct bio *bio = r10bio->devs[j].bio;
161 if (bio) {
162 for (i = 0; i < RESYNC_PAGES; i++) {
NeilBrown1345b1d2006-01-06 00:20:40 -0800163 safe_put_page(bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 bio->bi_io_vec[i].bv_page = NULL;
165 }
166 bio_put(bio);
167 }
168 }
169 r10bio_pool_free(r10bio, conf);
170}
171
172static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
173{
174 int i;
175
176 for (i = 0; i < conf->copies; i++) {
177 struct bio **bio = & r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -0800178 if (*bio && *bio != IO_BLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 bio_put(*bio);
180 *bio = NULL;
181 }
182}
183
Arjan van de Ven858119e2006-01-14 13:20:43 -0800184static void free_r10bio(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 conf_t *conf = mddev_to_conf(r10_bio->mddev);
187
188 /*
189 * Wake up any possible resync thread that waits for the device
190 * to go idle.
191 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800192 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 put_all_bios(conf, r10_bio);
195 mempool_free(r10_bio, conf->r10bio_pool);
196}
197
Arjan van de Ven858119e2006-01-14 13:20:43 -0800198static void put_buf(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
200 conf_t *conf = mddev_to_conf(r10_bio->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 mempool_free(r10_bio, conf->r10buf_pool);
203
NeilBrown0a27ec92006-01-06 00:20:13 -0800204 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207static void reschedule_retry(r10bio_t *r10_bio)
208{
209 unsigned long flags;
210 mddev_t *mddev = r10_bio->mddev;
211 conf_t *conf = mddev_to_conf(mddev);
212
213 spin_lock_irqsave(&conf->device_lock, flags);
214 list_add(&r10_bio->retry_list, &conf->retry_list);
NeilBrown4443ae12006-01-06 00:20:28 -0800215 conf->nr_queued ++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 spin_unlock_irqrestore(&conf->device_lock, flags);
217
218 md_wakeup_thread(mddev->thread);
219}
220
221/*
222 * raid_end_bio_io() is called when we have finished servicing a mirrored
223 * operation and are ready to return a success/failure code to the buffer
224 * cache layer.
225 */
226static void raid_end_bio_io(r10bio_t *r10_bio)
227{
228 struct bio *bio = r10_bio->master_bio;
229
230 bio_endio(bio, bio->bi_size,
231 test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO);
232 free_r10bio(r10_bio);
233}
234
235/*
236 * Update disk head position estimator based on IRQ completion info.
237 */
238static inline void update_head_pos(int slot, r10bio_t *r10_bio)
239{
240 conf_t *conf = mddev_to_conf(r10_bio->mddev);
241
242 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
243 r10_bio->devs[slot].addr + (r10_bio->sectors);
244}
245
246static int raid10_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
247{
248 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
249 r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private);
250 int slot, dev;
251 conf_t *conf = mddev_to_conf(r10_bio->mddev);
252
253 if (bio->bi_size)
254 return 1;
255
256 slot = r10_bio->read_slot;
257 dev = r10_bio->devs[slot].devnum;
258 /*
259 * this branch is our 'one mirror IO has finished' event handler:
260 */
NeilBrown4443ae12006-01-06 00:20:28 -0800261 update_head_pos(slot, r10_bio);
262
263 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 /*
265 * Set R10BIO_Uptodate in our master bio, so that
266 * we will return a good error code to the higher
267 * levels even if IO on some other mirrored buffer fails.
268 *
269 * The 'master' represents the composite IO operation to
270 * user-side. So if something waits for IO, then it will
271 * wait for the 'master' bio.
272 */
273 set_bit(R10BIO_Uptodate, &r10_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 raid_end_bio_io(r10_bio);
NeilBrown4443ae12006-01-06 00:20:28 -0800275 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 /*
277 * oops, read error:
278 */
279 char b[BDEVNAME_SIZE];
280 if (printk_ratelimit())
281 printk(KERN_ERR "raid10: %s: rescheduling sector %llu\n",
282 bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector);
283 reschedule_retry(r10_bio);
284 }
285
286 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
287 return 0;
288}
289
290static int raid10_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
291{
292 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
293 r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private);
294 int slot, dev;
295 conf_t *conf = mddev_to_conf(r10_bio->mddev);
296
297 if (bio->bi_size)
298 return 1;
299
300 for (slot = 0; slot < conf->copies; slot++)
301 if (r10_bio->devs[slot].bio == bio)
302 break;
303 dev = r10_bio->devs[slot].devnum;
304
305 /*
306 * this branch is our 'one mirror IO has finished' event handler:
307 */
NeilBrown6cce3b22006-01-06 00:20:16 -0800308 if (!uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
NeilBrown6cce3b22006-01-06 00:20:16 -0800310 /* an I/O failed, we can't clear the bitmap */
311 set_bit(R10BIO_Degraded, &r10_bio->state);
312 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 /*
314 * Set R10BIO_Uptodate in our master bio, so that
315 * we will return a good error code for to the higher
316 * levels even if IO on some other mirrored buffer fails.
317 *
318 * The 'master' represents the composite IO operation to
319 * user-side. So if something waits for IO, then it will
320 * wait for the 'master' bio.
321 */
322 set_bit(R10BIO_Uptodate, &r10_bio->state);
323
324 update_head_pos(slot, r10_bio);
325
326 /*
327 *
328 * Let's see if all mirrored write operations have finished
329 * already.
330 */
331 if (atomic_dec_and_test(&r10_bio->remaining)) {
NeilBrown6cce3b22006-01-06 00:20:16 -0800332 /* clear the bitmap if all writes complete successfully */
333 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
334 r10_bio->sectors,
335 !test_bit(R10BIO_Degraded, &r10_bio->state),
336 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 md_write_end(r10_bio->mddev);
338 raid_end_bio_io(r10_bio);
339 }
340
341 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
342 return 0;
343}
344
345
346/*
347 * RAID10 layout manager
348 * Aswell as the chunksize and raid_disks count, there are two
349 * parameters: near_copies and far_copies.
350 * near_copies * far_copies must be <= raid_disks.
351 * Normally one of these will be 1.
352 * If both are 1, we get raid0.
353 * If near_copies == raid_disks, we get raid1.
354 *
355 * Chunks are layed out in raid0 style with near_copies copies of the
356 * first chunk, followed by near_copies copies of the next chunk and
357 * so on.
358 * If far_copies > 1, then after 1/far_copies of the array has been assigned
359 * as described above, we start again with a device offset of near_copies.
360 * So we effectively have another copy of the whole array further down all
361 * the drives, but with blocks on different drives.
362 * With this layout, and block is never stored twice on the one device.
363 *
364 * raid10_find_phys finds the sector offset of a given virtual sector
NeilBrownc93983b2006-06-26 00:27:41 -0700365 * on each device that it is on.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 *
367 * raid10_find_virt does the reverse mapping, from a device and a
368 * sector offset to a virtual address
369 */
370
371static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio)
372{
373 int n,f;
374 sector_t sector;
375 sector_t chunk;
376 sector_t stripe;
377 int dev;
378
379 int slot = 0;
380
381 /* now calculate first sector/dev */
382 chunk = r10bio->sector >> conf->chunk_shift;
383 sector = r10bio->sector & conf->chunk_mask;
384
385 chunk *= conf->near_copies;
386 stripe = chunk;
387 dev = sector_div(stripe, conf->raid_disks);
NeilBrownc93983b2006-06-26 00:27:41 -0700388 if (conf->far_offset)
389 stripe *= conf->far_copies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
391 sector += stripe << conf->chunk_shift;
392
393 /* and calculate all the others */
394 for (n=0; n < conf->near_copies; n++) {
395 int d = dev;
396 sector_t s = sector;
397 r10bio->devs[slot].addr = sector;
398 r10bio->devs[slot].devnum = d;
399 slot++;
400
401 for (f = 1; f < conf->far_copies; f++) {
402 d += conf->near_copies;
403 if (d >= conf->raid_disks)
404 d -= conf->raid_disks;
405 s += conf->stride;
406 r10bio->devs[slot].devnum = d;
407 r10bio->devs[slot].addr = s;
408 slot++;
409 }
410 dev++;
411 if (dev >= conf->raid_disks) {
412 dev = 0;
413 sector += (conf->chunk_mask + 1);
414 }
415 }
416 BUG_ON(slot != conf->copies);
417}
418
419static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev)
420{
421 sector_t offset, chunk, vchunk;
422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 offset = sector & conf->chunk_mask;
NeilBrownc93983b2006-06-26 00:27:41 -0700424 if (conf->far_offset) {
425 int fc;
426 chunk = sector >> conf->chunk_shift;
427 fc = sector_div(chunk, conf->far_copies);
428 dev -= fc * conf->near_copies;
429 if (dev < 0)
430 dev += conf->raid_disks;
431 } else {
432 while (sector > conf->stride) {
433 sector -= conf->stride;
434 if (dev < conf->near_copies)
435 dev += conf->raid_disks - conf->near_copies;
436 else
437 dev -= conf->near_copies;
438 }
439 chunk = sector >> conf->chunk_shift;
440 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 vchunk = chunk * conf->raid_disks + dev;
442 sector_div(vchunk, conf->near_copies);
443 return (vchunk << conf->chunk_shift) + offset;
444}
445
446/**
447 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
448 * @q: request queue
449 * @bio: the buffer head that's been built up so far
450 * @biovec: the request that could be merged to it.
451 *
452 * Return amount of bytes we can accept at this offset
453 * If near_copies == raid_disk, there are no striping issues,
454 * but in that case, the function isn't called at all.
455 */
456static int raid10_mergeable_bvec(request_queue_t *q, struct bio *bio,
457 struct bio_vec *bio_vec)
458{
459 mddev_t *mddev = q->queuedata;
460 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
461 int max;
462 unsigned int chunk_sectors = mddev->chunk_size >> 9;
463 unsigned int bio_sectors = bio->bi_size >> 9;
464
465 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
466 if (max < 0) max = 0; /* bio_add cannot handle a negative return */
467 if (max <= bio_vec->bv_len && bio_sectors == 0)
468 return bio_vec->bv_len;
469 else
470 return max;
471}
472
473/*
474 * This routine returns the disk from which the requested read should
475 * be done. There is a per-array 'next expected sequential IO' sector
476 * number - if this matches on the next IO then we use the last disk.
477 * There is also a per-disk 'last know head position' sector that is
478 * maintained from IRQ contexts, both the normal and the resync IO
479 * completion handlers update this position correctly. If there is no
480 * perfect sequential match then we pick the disk whose head is closest.
481 *
482 * If there are 2 mirrors in the same 2 devices, performance degrades
483 * because position is mirror, not device based.
484 *
485 * The rdev for the device selected will have nr_pending incremented.
486 */
487
488/*
489 * FIXME: possibly should rethink readbalancing and do it differently
490 * depending on near_copies / far_copies geometry.
491 */
492static int read_balance(conf_t *conf, r10bio_t *r10_bio)
493{
494 const unsigned long this_sector = r10_bio->sector;
495 int disk, slot, nslot;
496 const int sectors = r10_bio->sectors;
497 sector_t new_distance, current_distance;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800498 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
500 raid10_find_phys(conf, r10_bio);
501 rcu_read_lock();
502 /*
503 * Check if we can balance. We can balance on the whole
NeilBrown6cce3b22006-01-06 00:20:16 -0800504 * device if no resync is going on (recovery is ok), or below
505 * the resync window. We take the first readable disk when
506 * above the resync window.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 */
508 if (conf->mddev->recovery_cp < MaxSector
509 && (this_sector + sectors >= conf->next_resync)) {
510 /* make sure that disk is operational */
511 slot = 0;
512 disk = r10_bio->devs[slot].devnum;
513
Suzanne Woodd6065f72005-11-08 21:39:27 -0800514 while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800515 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800516 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 slot++;
518 if (slot == conf->copies) {
519 slot = 0;
520 disk = -1;
521 break;
522 }
523 disk = r10_bio->devs[slot].devnum;
524 }
525 goto rb_out;
526 }
527
528
529 /* make sure the disk is operational */
530 slot = 0;
531 disk = r10_bio->devs[slot].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800532 while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800533 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800534 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 slot ++;
536 if (slot == conf->copies) {
537 disk = -1;
538 goto rb_out;
539 }
540 disk = r10_bio->devs[slot].devnum;
541 }
542
543
NeilBrown3ec67ac2005-09-09 16:23:40 -0700544 current_distance = abs(r10_bio->devs[slot].addr -
545 conf->mirrors[disk].head_position);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547 /* Find the disk whose head is closest */
548
549 for (nslot = slot; nslot < conf->copies; nslot++) {
550 int ndisk = r10_bio->devs[nslot].devnum;
551
552
Suzanne Woodd6065f72005-11-08 21:39:27 -0800553 if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800554 r10_bio->devs[nslot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800555 !test_bit(In_sync, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 continue;
557
NeilBrown22dfdf52005-11-28 13:44:09 -0800558 /* This optimisation is debatable, and completely destroys
559 * sequential read speed for 'far copies' arrays. So only
560 * keep it for 'near' arrays, and review those later.
561 */
562 if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 disk = ndisk;
564 slot = nslot;
565 break;
566 }
567 new_distance = abs(r10_bio->devs[nslot].addr -
568 conf->mirrors[ndisk].head_position);
569 if (new_distance < current_distance) {
570 current_distance = new_distance;
571 disk = ndisk;
572 slot = nslot;
573 }
574 }
575
576rb_out:
577 r10_bio->read_slot = slot;
578/* conf->next_seq_sect = this_sector + sectors;*/
579
Suzanne Woodd6065f72005-11-08 21:39:27 -0800580 if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
NeilBrown29fc7e32006-02-03 03:03:41 -0800582 else
583 disk = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 rcu_read_unlock();
585
586 return disk;
587}
588
589static void unplug_slaves(mddev_t *mddev)
590{
591 conf_t *conf = mddev_to_conf(mddev);
592 int i;
593
594 rcu_read_lock();
595 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800596 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800597 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
599
600 atomic_inc(&rdev->nr_pending);
601 rcu_read_unlock();
602
603 if (r_queue->unplug_fn)
604 r_queue->unplug_fn(r_queue);
605
606 rdev_dec_pending(rdev, mddev);
607 rcu_read_lock();
608 }
609 }
610 rcu_read_unlock();
611}
612
613static void raid10_unplug(request_queue_t *q)
614{
NeilBrown6cce3b22006-01-06 00:20:16 -0800615 mddev_t *mddev = q->queuedata;
616
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 unplug_slaves(q->queuedata);
NeilBrown6cce3b22006-01-06 00:20:16 -0800618 md_wakeup_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619}
620
621static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk,
622 sector_t *error_sector)
623{
624 mddev_t *mddev = q->queuedata;
625 conf_t *conf = mddev_to_conf(mddev);
626 int i, ret = 0;
627
628 rcu_read_lock();
629 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800630 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800631 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 struct block_device *bdev = rdev->bdev;
633 request_queue_t *r_queue = bdev_get_queue(bdev);
634
635 if (!r_queue->issue_flush_fn)
636 ret = -EOPNOTSUPP;
637 else {
638 atomic_inc(&rdev->nr_pending);
639 rcu_read_unlock();
640 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
641 error_sector);
642 rdev_dec_pending(rdev, mddev);
643 rcu_read_lock();
644 }
645 }
646 }
647 rcu_read_unlock();
648 return ret;
649}
650
NeilBrown0d129222006-10-03 01:15:54 -0700651static int raid10_congested(void *data, int bits)
652{
653 mddev_t *mddev = data;
654 conf_t *conf = mddev_to_conf(mddev);
655 int i, ret = 0;
656
657 rcu_read_lock();
658 for (i = 0; i < mddev->raid_disks && ret == 0; i++) {
659 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
660 if (rdev && !test_bit(Faulty, &rdev->flags)) {
661 request_queue_t *q = bdev_get_queue(rdev->bdev);
662
663 ret |= bdi_congested(&q->backing_dev_info, bits);
664 }
665 }
666 rcu_read_unlock();
667 return ret;
668}
669
670
NeilBrown0a27ec92006-01-06 00:20:13 -0800671/* Barriers....
672 * Sometimes we need to suspend IO while we do something else,
673 * either some resync/recovery, or reconfigure the array.
674 * To do this we raise a 'barrier'.
675 * The 'barrier' is a counter that can be raised multiple times
676 * to count how many activities are happening which preclude
677 * normal IO.
678 * We can only raise the barrier if there is no pending IO.
679 * i.e. if nr_pending == 0.
680 * We choose only to raise the barrier if no-one is waiting for the
681 * barrier to go down. This means that as soon as an IO request
682 * is ready, no other operations which require a barrier will start
683 * until the IO request has had a chance.
684 *
685 * So: regular IO calls 'wait_barrier'. When that returns there
686 * is no backgroup IO happening, It must arrange to call
687 * allow_barrier when it has finished its IO.
688 * backgroup IO calls must call raise_barrier. Once that returns
689 * there is no normal IO happeing. It must arrange to call
690 * lower_barrier when the particular background IO completes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 */
692#define RESYNC_DEPTH 32
693
NeilBrown6cce3b22006-01-06 00:20:16 -0800694static void raise_barrier(conf_t *conf, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695{
NeilBrown6cce3b22006-01-06 00:20:16 -0800696 BUG_ON(force && !conf->barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 spin_lock_irq(&conf->resync_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
NeilBrown6cce3b22006-01-06 00:20:16 -0800699 /* Wait until no block IO is waiting (unless 'force') */
700 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
NeilBrown0a27ec92006-01-06 00:20:13 -0800701 conf->resync_lock,
702 raid10_unplug(conf->mddev->queue));
703
704 /* block any new IO from starting */
705 conf->barrier++;
706
707 /* No wait for all pending IO to complete */
708 wait_event_lock_irq(conf->wait_barrier,
709 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
710 conf->resync_lock,
711 raid10_unplug(conf->mddev->queue));
712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 spin_unlock_irq(&conf->resync_lock);
714}
715
NeilBrown0a27ec92006-01-06 00:20:13 -0800716static void lower_barrier(conf_t *conf)
717{
718 unsigned long flags;
719 spin_lock_irqsave(&conf->resync_lock, flags);
720 conf->barrier--;
721 spin_unlock_irqrestore(&conf->resync_lock, flags);
722 wake_up(&conf->wait_barrier);
723}
724
725static void wait_barrier(conf_t *conf)
726{
727 spin_lock_irq(&conf->resync_lock);
728 if (conf->barrier) {
729 conf->nr_waiting++;
730 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
731 conf->resync_lock,
732 raid10_unplug(conf->mddev->queue));
733 conf->nr_waiting--;
734 }
735 conf->nr_pending++;
736 spin_unlock_irq(&conf->resync_lock);
737}
738
739static void allow_barrier(conf_t *conf)
740{
741 unsigned long flags;
742 spin_lock_irqsave(&conf->resync_lock, flags);
743 conf->nr_pending--;
744 spin_unlock_irqrestore(&conf->resync_lock, flags);
745 wake_up(&conf->wait_barrier);
746}
747
NeilBrown4443ae12006-01-06 00:20:28 -0800748static void freeze_array(conf_t *conf)
749{
750 /* stop syncio and normal IO and wait for everything to
NeilBrownf1885932006-01-06 00:20:42 -0800751 * go quiet.
NeilBrown4443ae12006-01-06 00:20:28 -0800752 * We increment barrier and nr_waiting, and then
753 * wait until barrier+nr_pending match nr_queued+2
754 */
755 spin_lock_irq(&conf->resync_lock);
756 conf->barrier++;
757 conf->nr_waiting++;
758 wait_event_lock_irq(conf->wait_barrier,
759 conf->barrier+conf->nr_pending == conf->nr_queued+2,
760 conf->resync_lock,
761 raid10_unplug(conf->mddev->queue));
762 spin_unlock_irq(&conf->resync_lock);
763}
764
765static void unfreeze_array(conf_t *conf)
766{
767 /* reverse the effect of the freeze */
768 spin_lock_irq(&conf->resync_lock);
769 conf->barrier--;
770 conf->nr_waiting--;
771 wake_up(&conf->wait_barrier);
772 spin_unlock_irq(&conf->resync_lock);
773}
774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775static int make_request(request_queue_t *q, struct bio * bio)
776{
777 mddev_t *mddev = q->queuedata;
778 conf_t *conf = mddev_to_conf(mddev);
779 mirror_info_t *mirror;
780 r10bio_t *r10_bio;
781 struct bio *read_bio;
782 int i;
783 int chunk_sects = conf->chunk_mask + 1;
Jens Axboea3623572005-11-01 09:26:16 +0100784 const int rw = bio_data_dir(bio);
NeilBrown6cce3b22006-01-06 00:20:16 -0800785 struct bio_list bl;
786 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787
NeilBrowne5dcdd82005-09-09 16:23:41 -0700788 if (unlikely(bio_barrier(bio))) {
789 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
790 return 0;
791 }
792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 /* If this request crosses a chunk boundary, we need to
794 * split it. This will only happen for 1 PAGE (or less) requests.
795 */
796 if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
797 > chunk_sects &&
798 conf->near_copies < conf->raid_disks)) {
799 struct bio_pair *bp;
800 /* Sanity check -- queue functions should prevent this happening */
801 if (bio->bi_vcnt != 1 ||
802 bio->bi_idx != 0)
803 goto bad_map;
804 /* This is a one page bio that upper layers
805 * refuse to split for us, so we need to split it.
806 */
807 bp = bio_split(bio, bio_split_pool,
808 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
809 if (make_request(q, &bp->bio1))
810 generic_make_request(&bp->bio1);
811 if (make_request(q, &bp->bio2))
812 generic_make_request(&bp->bio2);
813
814 bio_pair_release(bp);
815 return 0;
816 bad_map:
817 printk("raid10_make_request bug: can't convert block across chunks"
818 " or bigger than %dk %llu %d\n", chunk_sects/2,
819 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
820
821 bio_io_error(bio, bio->bi_size);
822 return 0;
823 }
824
NeilBrown3d310eb2005-06-21 17:17:26 -0700825 md_write_start(mddev, bio);
NeilBrown06d91a52005-06-21 17:17:12 -0700826
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 /*
828 * Register the new request and wait if the reconstruction
829 * thread has put up a bar for new requests.
830 * Continue immediately if no resync is active currently.
831 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800832 wait_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833
Jens Axboea3623572005-11-01 09:26:16 +0100834 disk_stat_inc(mddev->gendisk, ios[rw]);
835 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
838
839 r10_bio->master_bio = bio;
840 r10_bio->sectors = bio->bi_size >> 9;
841
842 r10_bio->mddev = mddev;
843 r10_bio->sector = bio->bi_sector;
NeilBrown6cce3b22006-01-06 00:20:16 -0800844 r10_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845
Jens Axboea3623572005-11-01 09:26:16 +0100846 if (rw == READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 /*
848 * read balancing logic:
849 */
850 int disk = read_balance(conf, r10_bio);
851 int slot = r10_bio->read_slot;
852 if (disk < 0) {
853 raid_end_bio_io(r10_bio);
854 return 0;
855 }
856 mirror = conf->mirrors + disk;
857
858 read_bio = bio_clone(bio, GFP_NOIO);
859
860 r10_bio->devs[slot].bio = read_bio;
861
862 read_bio->bi_sector = r10_bio->devs[slot].addr +
863 mirror->rdev->data_offset;
864 read_bio->bi_bdev = mirror->rdev->bdev;
865 read_bio->bi_end_io = raid10_end_read_request;
866 read_bio->bi_rw = READ;
867 read_bio->bi_private = r10_bio;
868
869 generic_make_request(read_bio);
870 return 0;
871 }
872
873 /*
874 * WRITE:
875 */
876 /* first select target devices under spinlock and
877 * inc refcount on their rdev. Record them by setting
878 * bios[x] to bio
879 */
880 raid10_find_phys(conf, r10_bio);
881 rcu_read_lock();
882 for (i = 0; i < conf->copies; i++) {
883 int d = r10_bio->devs[i].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800884 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
885 if (rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800886 !test_bit(Faulty, &rdev->flags)) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800887 atomic_inc(&rdev->nr_pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 r10_bio->devs[i].bio = bio;
NeilBrown6cce3b22006-01-06 00:20:16 -0800889 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 r10_bio->devs[i].bio = NULL;
NeilBrown6cce3b22006-01-06 00:20:16 -0800891 set_bit(R10BIO_Degraded, &r10_bio->state);
892 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 }
894 rcu_read_unlock();
895
NeilBrown6cce3b22006-01-06 00:20:16 -0800896 atomic_set(&r10_bio->remaining, 0);
NeilBrown06d91a52005-06-21 17:17:12 -0700897
NeilBrown6cce3b22006-01-06 00:20:16 -0800898 bio_list_init(&bl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 for (i = 0; i < conf->copies; i++) {
900 struct bio *mbio;
901 int d = r10_bio->devs[i].devnum;
902 if (!r10_bio->devs[i].bio)
903 continue;
904
905 mbio = bio_clone(bio, GFP_NOIO);
906 r10_bio->devs[i].bio = mbio;
907
908 mbio->bi_sector = r10_bio->devs[i].addr+
909 conf->mirrors[d].rdev->data_offset;
910 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
911 mbio->bi_end_io = raid10_end_write_request;
912 mbio->bi_rw = WRITE;
913 mbio->bi_private = r10_bio;
914
915 atomic_inc(&r10_bio->remaining);
NeilBrown6cce3b22006-01-06 00:20:16 -0800916 bio_list_add(&bl, mbio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 }
918
NeilBrown6cce3b22006-01-06 00:20:16 -0800919 bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0);
920 spin_lock_irqsave(&conf->device_lock, flags);
921 bio_list_merge(&conf->pending_bio_list, &bl);
922 blk_plug_device(mddev->queue);
923 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 return 0;
926}
927
928static void status(struct seq_file *seq, mddev_t *mddev)
929{
930 conf_t *conf = mddev_to_conf(mddev);
931 int i;
932
933 if (conf->near_copies < conf->raid_disks)
934 seq_printf(seq, " %dK chunks", mddev->chunk_size/1024);
935 if (conf->near_copies > 1)
936 seq_printf(seq, " %d near-copies", conf->near_copies);
NeilBrownc93983b2006-06-26 00:27:41 -0700937 if (conf->far_copies > 1) {
938 if (conf->far_offset)
939 seq_printf(seq, " %d offset-copies", conf->far_copies);
940 else
941 seq_printf(seq, " %d far-copies", conf->far_copies);
942 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
NeilBrown76186dd2006-10-03 01:15:48 -0700944 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 for (i = 0; i < conf->raid_disks; i++)
946 seq_printf(seq, "%s",
947 conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800948 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 seq_printf(seq, "]");
950}
951
952static void error(mddev_t *mddev, mdk_rdev_t *rdev)
953{
954 char b[BDEVNAME_SIZE];
955 conf_t *conf = mddev_to_conf(mddev);
956
957 /*
958 * If it is not operational, then we have already marked it as dead
959 * else if it is the last working disks, ignore the error, let the
960 * next level up know.
961 * else mark the drive as failed
962 */
NeilBrownb2d444d2005-11-08 21:39:31 -0800963 if (test_bit(In_sync, &rdev->flags)
NeilBrown76186dd2006-10-03 01:15:48 -0700964 && conf->raid_disks-mddev->degraded == 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 /*
966 * Don't fail the drive, just return an IO error.
967 * The test should really be more sophisticated than
968 * "working_disks == 1", but it isn't critical, and
969 * can wait until we do more sophisticated "is the drive
970 * really dead" tests...
971 */
972 return;
NeilBrownc04be0a2006-10-03 01:15:53 -0700973 if (test_and_clear_bit(In_sync, &rdev->flags)) {
974 unsigned long flags;
975 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -0700977 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 /*
979 * if recovery is running, make sure it aborts.
980 */
981 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
982 }
NeilBrownb2d444d2005-11-08 21:39:31 -0800983 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -0700984 set_bit(MD_CHANGE_DEVS, &mddev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n"
986 " Operation continuing on %d devices\n",
NeilBrown76186dd2006-10-03 01:15:48 -0700987 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988}
989
990static void print_conf(conf_t *conf)
991{
992 int i;
993 mirror_info_t *tmp;
994
995 printk("RAID10 conf printout:\n");
996 if (!conf) {
997 printk("(!conf)\n");
998 return;
999 }
NeilBrown76186dd2006-10-03 01:15:48 -07001000 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 conf->raid_disks);
1002
1003 for (i = 0; i < conf->raid_disks; i++) {
1004 char b[BDEVNAME_SIZE];
1005 tmp = conf->mirrors + i;
1006 if (tmp->rdev)
1007 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08001008 i, !test_bit(In_sync, &tmp->rdev->flags),
1009 !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 bdevname(tmp->rdev->bdev,b));
1011 }
1012}
1013
1014static void close_sync(conf_t *conf)
1015{
NeilBrown0a27ec92006-01-06 00:20:13 -08001016 wait_barrier(conf);
1017 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
1019 mempool_destroy(conf->r10buf_pool);
1020 conf->r10buf_pool = NULL;
1021}
1022
NeilBrown6d508242005-09-09 16:24:03 -07001023/* check if there are enough drives for
1024 * every block to appear on atleast one
1025 */
1026static int enough(conf_t *conf)
1027{
1028 int first = 0;
1029
1030 do {
1031 int n = conf->copies;
1032 int cnt = 0;
1033 while (n--) {
1034 if (conf->mirrors[first].rdev)
1035 cnt++;
1036 first = (first+1) % conf->raid_disks;
1037 }
1038 if (cnt == 0)
1039 return 0;
1040 } while (first != 0);
1041 return 1;
1042}
1043
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044static int raid10_spare_active(mddev_t *mddev)
1045{
1046 int i;
1047 conf_t *conf = mddev->private;
1048 mirror_info_t *tmp;
1049
1050 /*
1051 * Find all non-in_sync disks within the RAID10 configuration
1052 * and mark them in_sync
1053 */
1054 for (i = 0; i < conf->raid_disks; i++) {
1055 tmp = conf->mirrors + i;
1056 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08001057 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07001058 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
1059 unsigned long flags;
1060 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07001062 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 }
1064 }
1065
1066 print_conf(conf);
1067 return 0;
1068}
1069
1070
1071static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1072{
1073 conf_t *conf = mddev->private;
1074 int found = 0;
1075 int mirror;
1076 mirror_info_t *p;
1077
1078 if (mddev->recovery_cp < MaxSector)
1079 /* only hot-add to in-sync arrays, as recovery is
1080 * very different from resync
1081 */
1082 return 0;
NeilBrown6d508242005-09-09 16:24:03 -07001083 if (!enough(conf))
1084 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085
NeilBrown6cce3b22006-01-06 00:20:16 -08001086 if (rdev->saved_raid_disk >= 0 &&
1087 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1088 mirror = rdev->saved_raid_disk;
1089 else
1090 mirror = 0;
1091 for ( ; mirror < mddev->raid_disks; mirror++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 if ( !(p=conf->mirrors+mirror)->rdev) {
1093
1094 blk_queue_stack_limits(mddev->queue,
1095 rdev->bdev->bd_disk->queue);
1096 /* as we don't honour merge_bvec_fn, we must never risk
1097 * violating it, so limit ->max_sector to one PAGE, as
1098 * a one page request is never in violation.
1099 */
1100 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1101 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1102 mddev->queue->max_sectors = (PAGE_SIZE>>9);
1103
1104 p->head_position = 0;
1105 rdev->raid_disk = mirror;
1106 found = 1;
NeilBrown6cce3b22006-01-06 00:20:16 -08001107 if (rdev->saved_raid_disk != mirror)
1108 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08001109 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 break;
1111 }
1112
1113 print_conf(conf);
1114 return found;
1115}
1116
1117static int raid10_remove_disk(mddev_t *mddev, int number)
1118{
1119 conf_t *conf = mddev->private;
1120 int err = 0;
1121 mdk_rdev_t *rdev;
1122 mirror_info_t *p = conf->mirrors+ number;
1123
1124 print_conf(conf);
1125 rdev = p->rdev;
1126 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08001127 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 atomic_read(&rdev->nr_pending)) {
1129 err = -EBUSY;
1130 goto abort;
1131 }
1132 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07001133 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 if (atomic_read(&rdev->nr_pending)) {
1135 /* lost the race, try later */
1136 err = -EBUSY;
1137 p->rdev = rdev;
1138 }
1139 }
1140abort:
1141
1142 print_conf(conf);
1143 return err;
1144}
1145
1146
1147static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1148{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private);
1150 conf_t *conf = mddev_to_conf(r10_bio->mddev);
1151 int i,d;
1152
1153 if (bio->bi_size)
1154 return 1;
1155
1156 for (i=0; i<conf->copies; i++)
1157 if (r10_bio->devs[i].bio == bio)
1158 break;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001159 BUG_ON(i == conf->copies);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 update_head_pos(i, r10_bio);
1161 d = r10_bio->devs[i].devnum;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001162
1163 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1164 set_bit(R10BIO_Uptodate, &r10_bio->state);
NeilBrown4dbcdc72006-01-06 00:20:52 -08001165 else {
1166 atomic_add(r10_bio->sectors,
1167 &conf->mirrors[d].rdev->corrected_errors);
1168 if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
1169 md_error(r10_bio->mddev,
1170 conf->mirrors[d].rdev);
1171 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
1173 /* for reconstruct, we always reschedule after a read.
1174 * for resync, only after all reads
1175 */
1176 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1177 atomic_dec_and_test(&r10_bio->remaining)) {
1178 /* we have read all the blocks,
1179 * do the comparison in process context in raid10d
1180 */
1181 reschedule_retry(r10_bio);
1182 }
1183 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
1184 return 0;
1185}
1186
1187static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1188{
1189 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1190 r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private);
1191 mddev_t *mddev = r10_bio->mddev;
1192 conf_t *conf = mddev_to_conf(mddev);
1193 int i,d;
1194
1195 if (bio->bi_size)
1196 return 1;
1197
1198 for (i = 0; i < conf->copies; i++)
1199 if (r10_bio->devs[i].bio == bio)
1200 break;
1201 d = r10_bio->devs[i].devnum;
1202
1203 if (!uptodate)
1204 md_error(mddev, conf->mirrors[d].rdev);
1205 update_head_pos(i, r10_bio);
1206
1207 while (atomic_dec_and_test(&r10_bio->remaining)) {
1208 if (r10_bio->master_bio == NULL) {
1209 /* the primary of several recovery bios */
1210 md_done_sync(mddev, r10_bio->sectors, 1);
1211 put_buf(r10_bio);
1212 break;
1213 } else {
1214 r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio;
1215 put_buf(r10_bio);
1216 r10_bio = r10_bio2;
1217 }
1218 }
1219 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1220 return 0;
1221}
1222
1223/*
1224 * Note: sync and recover and handled very differently for raid10
1225 * This code is for resync.
1226 * For resync, we read through virtual addresses and read all blocks.
1227 * If there is any error, we schedule a write. The lowest numbered
1228 * drive is authoritative.
1229 * However requests come for physical address, so we need to map.
1230 * For every physical address there are raid_disks/copies virtual addresses,
1231 * which is always are least one, but is not necessarly an integer.
1232 * This means that a physical address can span multiple chunks, so we may
1233 * have to submit multiple io requests for a single sync request.
1234 */
1235/*
1236 * We check if all blocks are in-sync and only write to blocks that
1237 * aren't in sync
1238 */
1239static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1240{
1241 conf_t *conf = mddev_to_conf(mddev);
1242 int i, first;
1243 struct bio *tbio, *fbio;
1244
1245 atomic_set(&r10_bio->remaining, 1);
1246
1247 /* find the first device with a block */
1248 for (i=0; i<conf->copies; i++)
1249 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
1250 break;
1251
1252 if (i == conf->copies)
1253 goto done;
1254
1255 first = i;
1256 fbio = r10_bio->devs[i].bio;
1257
1258 /* now find blocks with errors */
NeilBrown0eb3ff12006-01-06 00:20:29 -08001259 for (i=0 ; i < conf->copies ; i++) {
1260 int j, d;
1261 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 tbio = r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001264
1265 if (tbio->bi_end_io != end_sync_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 continue;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001267 if (i == first)
1268 continue;
1269 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
1270 /* We know that the bi_io_vec layout is the same for
1271 * both 'first' and 'i', so we just compare them.
1272 * All vec entries are PAGE_SIZE;
1273 */
1274 for (j = 0; j < vcnt; j++)
1275 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
1276 page_address(tbio->bi_io_vec[j].bv_page),
1277 PAGE_SIZE))
1278 break;
1279 if (j == vcnt)
1280 continue;
1281 mddev->resync_mismatches += r10_bio->sectors;
1282 }
NeilBrown18f08812006-01-06 00:20:25 -08001283 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1284 /* Don't fix anything. */
1285 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 /* Ok, we need to write this bio
1287 * First we need to fixup bv_offset, bv_len and
1288 * bi_vecs, as the read request might have corrupted these
1289 */
1290 tbio->bi_vcnt = vcnt;
1291 tbio->bi_size = r10_bio->sectors << 9;
1292 tbio->bi_idx = 0;
1293 tbio->bi_phys_segments = 0;
1294 tbio->bi_hw_segments = 0;
1295 tbio->bi_hw_front_size = 0;
1296 tbio->bi_hw_back_size = 0;
1297 tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1298 tbio->bi_flags |= 1 << BIO_UPTODATE;
1299 tbio->bi_next = NULL;
1300 tbio->bi_rw = WRITE;
1301 tbio->bi_private = r10_bio;
1302 tbio->bi_sector = r10_bio->devs[i].addr;
1303
1304 for (j=0; j < vcnt ; j++) {
1305 tbio->bi_io_vec[j].bv_offset = 0;
1306 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
1307
1308 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1309 page_address(fbio->bi_io_vec[j].bv_page),
1310 PAGE_SIZE);
1311 }
1312 tbio->bi_end_io = end_sync_write;
1313
1314 d = r10_bio->devs[i].devnum;
1315 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1316 atomic_inc(&r10_bio->remaining);
1317 md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
1318
1319 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
1320 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1321 generic_make_request(tbio);
1322 }
1323
1324done:
1325 if (atomic_dec_and_test(&r10_bio->remaining)) {
1326 md_done_sync(mddev, r10_bio->sectors, 1);
1327 put_buf(r10_bio);
1328 }
1329}
1330
1331/*
1332 * Now for the recovery code.
1333 * Recovery happens across physical sectors.
1334 * We recover all non-is_sync drives by finding the virtual address of
1335 * each, and then choose a working drive that also has that virt address.
1336 * There is a separate r10_bio for each non-in_sync drive.
1337 * Only the first two slots are in use. The first for reading,
1338 * The second for writing.
1339 *
1340 */
1341
1342static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1343{
1344 conf_t *conf = mddev_to_conf(mddev);
1345 int i, d;
1346 struct bio *bio, *wbio;
1347
1348
1349 /* move the pages across to the second bio
1350 * and submit the write request
1351 */
1352 bio = r10_bio->devs[0].bio;
1353 wbio = r10_bio->devs[1].bio;
1354 for (i=0; i < wbio->bi_vcnt; i++) {
1355 struct page *p = bio->bi_io_vec[i].bv_page;
1356 bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page;
1357 wbio->bi_io_vec[i].bv_page = p;
1358 }
1359 d = r10_bio->devs[1].devnum;
1360
1361 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1362 md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
NeilBrown0eb3ff12006-01-06 00:20:29 -08001363 if (test_bit(R10BIO_Uptodate, &r10_bio->state))
1364 generic_make_request(wbio);
1365 else
1366 bio_endio(wbio, wbio->bi_size, -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367}
1368
1369
1370/*
1371 * This is a kernel thread which:
1372 *
1373 * 1. Retries failed read operations on working mirrors.
1374 * 2. Updates the raid superblock when problems encounter.
NeilBrown6814d532006-10-03 01:15:45 -07001375 * 3. Performs writes following reads for array synchronising.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 */
1377
NeilBrown6814d532006-10-03 01:15:45 -07001378static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
1379{
1380 int sect = 0; /* Offset from r10_bio->sector */
1381 int sectors = r10_bio->sectors;
1382 mdk_rdev_t*rdev;
1383 while(sectors) {
1384 int s = sectors;
1385 int sl = r10_bio->read_slot;
1386 int success = 0;
1387 int start;
1388
1389 if (s > (PAGE_SIZE>>9))
1390 s = PAGE_SIZE >> 9;
1391
1392 rcu_read_lock();
1393 do {
1394 int d = r10_bio->devs[sl].devnum;
1395 rdev = rcu_dereference(conf->mirrors[d].rdev);
1396 if (rdev &&
1397 test_bit(In_sync, &rdev->flags)) {
1398 atomic_inc(&rdev->nr_pending);
1399 rcu_read_unlock();
1400 success = sync_page_io(rdev->bdev,
1401 r10_bio->devs[sl].addr +
1402 sect + rdev->data_offset,
1403 s<<9,
1404 conf->tmppage, READ);
1405 rdev_dec_pending(rdev, mddev);
1406 rcu_read_lock();
1407 if (success)
1408 break;
1409 }
1410 sl++;
1411 if (sl == conf->copies)
1412 sl = 0;
1413 } while (!success && sl != r10_bio->read_slot);
1414 rcu_read_unlock();
1415
1416 if (!success) {
1417 /* Cannot read from anywhere -- bye bye array */
1418 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
1419 md_error(mddev, conf->mirrors[dn].rdev);
1420 break;
1421 }
1422
1423 start = sl;
1424 /* write it back and re-read */
1425 rcu_read_lock();
1426 while (sl != r10_bio->read_slot) {
1427 int d;
1428 if (sl==0)
1429 sl = conf->copies;
1430 sl--;
1431 d = r10_bio->devs[sl].devnum;
1432 rdev = rcu_dereference(conf->mirrors[d].rdev);
1433 if (rdev &&
1434 test_bit(In_sync, &rdev->flags)) {
1435 atomic_inc(&rdev->nr_pending);
1436 rcu_read_unlock();
1437 atomic_add(s, &rdev->corrected_errors);
1438 if (sync_page_io(rdev->bdev,
1439 r10_bio->devs[sl].addr +
1440 sect + rdev->data_offset,
1441 s<<9, conf->tmppage, WRITE)
1442 == 0)
1443 /* Well, this device is dead */
1444 md_error(mddev, rdev);
1445 rdev_dec_pending(rdev, mddev);
1446 rcu_read_lock();
1447 }
1448 }
1449 sl = start;
1450 while (sl != r10_bio->read_slot) {
1451 int d;
1452 if (sl==0)
1453 sl = conf->copies;
1454 sl--;
1455 d = r10_bio->devs[sl].devnum;
1456 rdev = rcu_dereference(conf->mirrors[d].rdev);
1457 if (rdev &&
1458 test_bit(In_sync, &rdev->flags)) {
1459 char b[BDEVNAME_SIZE];
1460 atomic_inc(&rdev->nr_pending);
1461 rcu_read_unlock();
1462 if (sync_page_io(rdev->bdev,
1463 r10_bio->devs[sl].addr +
1464 sect + rdev->data_offset,
1465 s<<9, conf->tmppage, READ) == 0)
1466 /* Well, this device is dead */
1467 md_error(mddev, rdev);
1468 else
1469 printk(KERN_INFO
1470 "raid10:%s: read error corrected"
1471 " (%d sectors at %llu on %s)\n",
1472 mdname(mddev), s,
Randy Dunlap969b7552006-10-28 10:38:32 -07001473 (unsigned long long)(sect+
1474 rdev->data_offset),
NeilBrown6814d532006-10-03 01:15:45 -07001475 bdevname(rdev->bdev, b));
1476
1477 rdev_dec_pending(rdev, mddev);
1478 rcu_read_lock();
1479 }
1480 }
1481 rcu_read_unlock();
1482
1483 sectors -= s;
1484 sect += s;
1485 }
1486}
1487
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488static void raid10d(mddev_t *mddev)
1489{
1490 r10bio_t *r10_bio;
1491 struct bio *bio;
1492 unsigned long flags;
1493 conf_t *conf = mddev_to_conf(mddev);
1494 struct list_head *head = &conf->retry_list;
1495 int unplug=0;
1496 mdk_rdev_t *rdev;
1497
1498 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499
1500 for (;;) {
1501 char b[BDEVNAME_SIZE];
1502 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown6cce3b22006-01-06 00:20:16 -08001503
1504 if (conf->pending_bio_list.head) {
1505 bio = bio_list_get(&conf->pending_bio_list);
1506 blk_remove_plug(mddev->queue);
1507 spin_unlock_irqrestore(&conf->device_lock, flags);
1508 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1509 if (bitmap_unplug(mddev->bitmap) != 0)
1510 printk("%s: bitmap file write failed!\n", mdname(mddev));
1511
1512 while (bio) { /* submit pending writes */
1513 struct bio *next = bio->bi_next;
1514 bio->bi_next = NULL;
1515 generic_make_request(bio);
1516 bio = next;
1517 }
1518 unplug = 1;
1519
1520 continue;
1521 }
1522
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 if (list_empty(head))
1524 break;
1525 r10_bio = list_entry(head->prev, r10bio_t, retry_list);
1526 list_del(head->prev);
NeilBrown4443ae12006-01-06 00:20:28 -08001527 conf->nr_queued--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 spin_unlock_irqrestore(&conf->device_lock, flags);
1529
1530 mddev = r10_bio->mddev;
1531 conf = mddev_to_conf(mddev);
1532 if (test_bit(R10BIO_IsSync, &r10_bio->state)) {
1533 sync_request_write(mddev, r10_bio);
1534 unplug = 1;
1535 } else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) {
1536 recovery_request_write(mddev, r10_bio);
1537 unplug = 1;
1538 } else {
1539 int mirror;
NeilBrown4443ae12006-01-06 00:20:28 -08001540 /* we got a read error. Maybe the drive is bad. Maybe just
1541 * the block and we can fix it.
1542 * We freeze all other IO, and try reading the block from
1543 * other devices. When we find one, we re-write
1544 * and check it that fixes the read error.
1545 * This is all done synchronously while the array is
1546 * frozen.
1547 */
NeilBrown6814d532006-10-03 01:15:45 -07001548 if (mddev->ro == 0) {
1549 freeze_array(conf);
1550 fix_read_error(conf, mddev, r10_bio);
1551 unfreeze_array(conf);
NeilBrown4443ae12006-01-06 00:20:28 -08001552 }
1553
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554 bio = r10_bio->devs[r10_bio->read_slot].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001555 r10_bio->devs[r10_bio->read_slot].bio =
1556 mddev->ro ? IO_BLOCKED : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557 bio_put(bio);
1558 mirror = read_balance(conf, r10_bio);
1559 if (mirror == -1) {
1560 printk(KERN_ALERT "raid10: %s: unrecoverable I/O"
1561 " read error for block %llu\n",
1562 bdevname(bio->bi_bdev,b),
1563 (unsigned long long)r10_bio->sector);
1564 raid_end_bio_io(r10_bio);
1565 } else {
1566 rdev = conf->mirrors[mirror].rdev;
1567 if (printk_ratelimit())
1568 printk(KERN_ERR "raid10: %s: redirecting sector %llu to"
1569 " another mirror\n",
1570 bdevname(rdev->bdev,b),
1571 (unsigned long long)r10_bio->sector);
1572 bio = bio_clone(r10_bio->master_bio, GFP_NOIO);
1573 r10_bio->devs[r10_bio->read_slot].bio = bio;
1574 bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr
1575 + rdev->data_offset;
1576 bio->bi_bdev = rdev->bdev;
1577 bio->bi_rw = READ;
1578 bio->bi_private = r10_bio;
1579 bio->bi_end_io = raid10_end_read_request;
1580 unplug = 1;
1581 generic_make_request(bio);
1582 }
1583 }
1584 }
1585 spin_unlock_irqrestore(&conf->device_lock, flags);
1586 if (unplug)
1587 unplug_slaves(mddev);
1588}
1589
1590
1591static int init_resync(conf_t *conf)
1592{
1593 int buffs;
1594
1595 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001596 BUG_ON(conf->r10buf_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
1598 if (!conf->r10buf_pool)
1599 return -ENOMEM;
1600 conf->next_resync = 0;
1601 return 0;
1602}
1603
1604/*
1605 * perform a "sync" on one "block"
1606 *
1607 * We need to make sure that no normal I/O request - particularly write
1608 * requests - conflict with active sync requests.
1609 *
1610 * This is achieved by tracking pending requests and a 'barrier' concept
1611 * that can be installed to exclude normal IO requests.
1612 *
1613 * Resync and recovery are handled very differently.
1614 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
1615 *
1616 * For resync, we iterate over virtual addresses, read all copies,
1617 * and update if there are differences. If only one copy is live,
1618 * skip it.
1619 * For recovery, we iterate over physical addresses, read a good
1620 * value for each non-in_sync drive, and over-write.
1621 *
1622 * So, for recovery we may have several outstanding complex requests for a
1623 * given address, one for each out-of-sync device. We model this by allocating
1624 * a number of r10_bio structures, one for each out-of-sync device.
1625 * As we setup these structures, we collect all bio's together into a list
1626 * which we then process collectively to add pages, and then process again
1627 * to pass to generic_make_request.
1628 *
1629 * The r10_bio structures are linked using a borrowed master_bio pointer.
1630 * This link is counted in ->remaining. When the r10_bio that points to NULL
1631 * has its remaining count decremented to 0, the whole complex operation
1632 * is complete.
1633 *
1634 */
1635
NeilBrown57afd892005-06-21 17:17:13 -07001636static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637{
1638 conf_t *conf = mddev_to_conf(mddev);
1639 r10bio_t *r10_bio;
1640 struct bio *biolist = NULL, *bio;
1641 sector_t max_sector, nr_sectors;
1642 int disk;
1643 int i;
NeilBrown6cce3b22006-01-06 00:20:16 -08001644 int max_sync;
1645 int sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646
1647 sector_t sectors_skipped = 0;
1648 int chunks_skipped = 0;
1649
1650 if (!conf->r10buf_pool)
1651 if (init_resync(conf))
NeilBrown57afd892005-06-21 17:17:13 -07001652 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001653
1654 skipped:
1655 max_sector = mddev->size << 1;
1656 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1657 max_sector = mddev->resync_max_sectors;
1658 if (sector_nr >= max_sector) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001659 /* If we aborted, we need to abort the
1660 * sync on the 'current' bitmap chucks (there can
1661 * be several when recovering multiple devices).
1662 * as we may have started syncing it but not finished.
1663 * We can find the current address in
1664 * mddev->curr_resync, but for recovery,
1665 * we need to convert that to several
1666 * virtual addresses.
1667 */
1668 if (mddev->curr_resync < max_sector) { /* aborted */
1669 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1670 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1671 &sync_blocks, 1);
1672 else for (i=0; i<conf->raid_disks; i++) {
1673 sector_t sect =
1674 raid10_find_virt(conf, mddev->curr_resync, i);
1675 bitmap_end_sync(mddev->bitmap, sect,
1676 &sync_blocks, 1);
1677 }
1678 } else /* completed sync */
1679 conf->fullsync = 0;
1680
1681 bitmap_close_sync(mddev->bitmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 close_sync(conf);
NeilBrown57afd892005-06-21 17:17:13 -07001683 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 return sectors_skipped;
1685 }
1686 if (chunks_skipped >= conf->raid_disks) {
1687 /* if there has been nothing to do on any drive,
1688 * then there is nothing to do at all..
1689 */
NeilBrown57afd892005-06-21 17:17:13 -07001690 *skipped = 1;
1691 return (max_sector - sector_nr) + sectors_skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692 }
1693
1694 /* make sure whole request will fit in a chunk - if chunks
1695 * are meaningful
1696 */
1697 if (conf->near_copies < conf->raid_disks &&
1698 max_sector > (sector_nr | conf->chunk_mask))
1699 max_sector = (sector_nr | conf->chunk_mask) + 1;
1700 /*
1701 * If there is non-resync activity waiting for us then
1702 * put in a delay to throttle resync.
1703 */
NeilBrown0a27ec92006-01-06 00:20:13 -08001704 if (!go_faster && conf->nr_waiting)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 msleep_interruptible(1000);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
1707 /* Again, very different code for resync and recovery.
1708 * Both must result in an r10bio with a list of bios that
1709 * have bi_end_io, bi_sector, bi_bdev set,
1710 * and bi_private set to the r10bio.
1711 * For recovery, we may actually create several r10bios
1712 * with 2 bios in each, that correspond to the bios in the main one.
1713 * In this case, the subordinate r10bios link back through a
1714 * borrowed master_bio pointer, and the counter in the master
1715 * includes a ref from each subordinate.
1716 */
1717 /* First, we decide what to do and set ->bi_end_io
1718 * To end_sync_read if we want to read, and
1719 * end_sync_write if we will want to write.
1720 */
1721
NeilBrown6cce3b22006-01-06 00:20:16 -08001722 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1724 /* recovery... the complicated one */
1725 int i, j, k;
1726 r10_bio = NULL;
1727
1728 for (i=0 ; i<conf->raid_disks; i++)
1729 if (conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001730 !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001731 int still_degraded = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732 /* want to reconstruct this device */
1733 r10bio_t *rb2 = r10_bio;
NeilBrown6cce3b22006-01-06 00:20:16 -08001734 sector_t sect = raid10_find_virt(conf, sector_nr, i);
1735 int must_sync;
1736 /* Unless we are doing a full sync, we only need
1737 * to recover the block if it is set in the bitmap
1738 */
1739 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1740 &sync_blocks, 1);
1741 if (sync_blocks < max_sync)
1742 max_sync = sync_blocks;
1743 if (!must_sync &&
1744 !conf->fullsync) {
1745 /* yep, skip the sync_blocks here, but don't assume
1746 * that there will never be anything to do here
1747 */
1748 chunks_skipped = -1;
1749 continue;
1750 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001751
1752 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
NeilBrown6cce3b22006-01-06 00:20:16 -08001753 raise_barrier(conf, rb2 != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 atomic_set(&r10_bio->remaining, 0);
1755
1756 r10_bio->master_bio = (struct bio*)rb2;
1757 if (rb2)
1758 atomic_inc(&rb2->remaining);
1759 r10_bio->mddev = mddev;
1760 set_bit(R10BIO_IsRecover, &r10_bio->state);
NeilBrown6cce3b22006-01-06 00:20:16 -08001761 r10_bio->sector = sect;
1762
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 raid10_find_phys(conf, r10_bio);
NeilBrown6cce3b22006-01-06 00:20:16 -08001764 /* Need to check if this section will still be
1765 * degraded
1766 */
1767 for (j=0; j<conf->copies;j++) {
1768 int d = r10_bio->devs[j].devnum;
1769 if (conf->mirrors[d].rdev == NULL ||
NeilBrowna24a8dd2006-01-06 00:20:35 -08001770 test_bit(Faulty, &conf->mirrors[d].rdev->flags)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001771 still_degraded = 1;
NeilBrowna24a8dd2006-01-06 00:20:35 -08001772 break;
1773 }
NeilBrown6cce3b22006-01-06 00:20:16 -08001774 }
1775 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1776 &sync_blocks, still_degraded);
1777
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778 for (j=0; j<conf->copies;j++) {
1779 int d = r10_bio->devs[j].devnum;
1780 if (conf->mirrors[d].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001781 test_bit(In_sync, &conf->mirrors[d].rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782 /* This is where we read from */
1783 bio = r10_bio->devs[0].bio;
1784 bio->bi_next = biolist;
1785 biolist = bio;
1786 bio->bi_private = r10_bio;
1787 bio->bi_end_io = end_sync_read;
1788 bio->bi_rw = 0;
1789 bio->bi_sector = r10_bio->devs[j].addr +
1790 conf->mirrors[d].rdev->data_offset;
1791 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
1792 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1793 atomic_inc(&r10_bio->remaining);
1794 /* and we write to 'i' */
1795
1796 for (k=0; k<conf->copies; k++)
1797 if (r10_bio->devs[k].devnum == i)
1798 break;
1799 bio = r10_bio->devs[1].bio;
1800 bio->bi_next = biolist;
1801 biolist = bio;
1802 bio->bi_private = r10_bio;
1803 bio->bi_end_io = end_sync_write;
1804 bio->bi_rw = 1;
1805 bio->bi_sector = r10_bio->devs[k].addr +
1806 conf->mirrors[i].rdev->data_offset;
1807 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1808
1809 r10_bio->devs[0].devnum = d;
1810 r10_bio->devs[1].devnum = i;
1811
1812 break;
1813 }
1814 }
1815 if (j == conf->copies) {
NeilBrown87fc7672005-09-09 16:24:04 -07001816 /* Cannot recover, so abort the recovery */
1817 put_buf(r10_bio);
1818 r10_bio = rb2;
1819 if (!test_and_set_bit(MD_RECOVERY_ERR, &mddev->recovery))
1820 printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n",
1821 mdname(mddev));
1822 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823 }
1824 }
1825 if (biolist == NULL) {
1826 while (r10_bio) {
1827 r10bio_t *rb2 = r10_bio;
1828 r10_bio = (r10bio_t*) rb2->master_bio;
1829 rb2->master_bio = NULL;
1830 put_buf(rb2);
1831 }
1832 goto giveup;
1833 }
1834 } else {
1835 /* resync. Schedule a read for every block at this virt offset */
1836 int count = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08001837
1838 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1839 &sync_blocks, mddev->degraded) &&
1840 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1841 /* We can skip this block */
1842 *skipped = 1;
1843 return sync_blocks + sectors_skipped;
1844 }
1845 if (sync_blocks < max_sync)
1846 max_sync = sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
1848
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 r10_bio->mddev = mddev;
1850 atomic_set(&r10_bio->remaining, 0);
NeilBrown6cce3b22006-01-06 00:20:16 -08001851 raise_barrier(conf, 0);
1852 conf->next_resync = sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853
1854 r10_bio->master_bio = NULL;
1855 r10_bio->sector = sector_nr;
1856 set_bit(R10BIO_IsSync, &r10_bio->state);
1857 raid10_find_phys(conf, r10_bio);
1858 r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
1859
1860 for (i=0; i<conf->copies; i++) {
1861 int d = r10_bio->devs[i].devnum;
1862 bio = r10_bio->devs[i].bio;
1863 bio->bi_end_io = NULL;
1864 if (conf->mirrors[d].rdev == NULL ||
NeilBrownb2d444d2005-11-08 21:39:31 -08001865 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001866 continue;
1867 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1868 atomic_inc(&r10_bio->remaining);
1869 bio->bi_next = biolist;
1870 biolist = bio;
1871 bio->bi_private = r10_bio;
1872 bio->bi_end_io = end_sync_read;
1873 bio->bi_rw = 0;
1874 bio->bi_sector = r10_bio->devs[i].addr +
1875 conf->mirrors[d].rdev->data_offset;
1876 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
1877 count++;
1878 }
1879
1880 if (count < 2) {
1881 for (i=0; i<conf->copies; i++) {
1882 int d = r10_bio->devs[i].devnum;
1883 if (r10_bio->devs[i].bio->bi_end_io)
1884 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1885 }
1886 put_buf(r10_bio);
1887 biolist = NULL;
1888 goto giveup;
1889 }
1890 }
1891
1892 for (bio = biolist; bio ; bio=bio->bi_next) {
1893
1894 bio->bi_flags &= ~(BIO_POOL_MASK - 1);
1895 if (bio->bi_end_io)
1896 bio->bi_flags |= 1 << BIO_UPTODATE;
1897 bio->bi_vcnt = 0;
1898 bio->bi_idx = 0;
1899 bio->bi_phys_segments = 0;
1900 bio->bi_hw_segments = 0;
1901 bio->bi_size = 0;
1902 }
1903
1904 nr_sectors = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08001905 if (sector_nr + max_sync < max_sector)
1906 max_sector = sector_nr + max_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 do {
1908 struct page *page;
1909 int len = PAGE_SIZE;
1910 disk = 0;
1911 if (sector_nr + (len>>9) > max_sector)
1912 len = (max_sector - sector_nr) << 9;
1913 if (len == 0)
1914 break;
1915 for (bio= biolist ; bio ; bio=bio->bi_next) {
1916 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1917 if (bio_add_page(bio, page, len, 0) == 0) {
1918 /* stop here */
1919 struct bio *bio2;
1920 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1921 for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) {
1922 /* remove last page from this bio */
1923 bio2->bi_vcnt--;
1924 bio2->bi_size -= len;
1925 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
1926 }
1927 goto bio_full;
1928 }
1929 disk = i;
1930 }
1931 nr_sectors += len>>9;
1932 sector_nr += len>>9;
1933 } while (biolist->bi_vcnt < RESYNC_PAGES);
1934 bio_full:
1935 r10_bio->sectors = nr_sectors;
1936
1937 while (biolist) {
1938 bio = biolist;
1939 biolist = biolist->bi_next;
1940
1941 bio->bi_next = NULL;
1942 r10_bio = bio->bi_private;
1943 r10_bio->sectors = nr_sectors;
1944
1945 if (bio->bi_end_io == end_sync_read) {
1946 md_sync_acct(bio->bi_bdev, nr_sectors);
1947 generic_make_request(bio);
1948 }
1949 }
1950
NeilBrown57afd892005-06-21 17:17:13 -07001951 if (sectors_skipped)
1952 /* pretend they weren't skipped, it makes
1953 * no important difference in this case
1954 */
1955 md_done_sync(mddev, sectors_skipped, 1);
1956
Linus Torvalds1da177e2005-04-16 15:20:36 -07001957 return sectors_skipped + nr_sectors;
1958 giveup:
1959 /* There is nowhere to write, so all non-sync
1960 * drives must be failed, so try the next chunk...
1961 */
1962 {
NeilBrown57afd892005-06-21 17:17:13 -07001963 sector_t sec = max_sector - sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 sectors_skipped += sec;
1965 chunks_skipped ++;
1966 sector_nr = max_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967 goto skipped;
1968 }
1969}
1970
1971static int run(mddev_t *mddev)
1972{
1973 conf_t *conf;
1974 int i, disk_idx;
1975 mirror_info_t *disk;
1976 mdk_rdev_t *rdev;
1977 struct list_head *tmp;
NeilBrownc93983b2006-06-26 00:27:41 -07001978 int nc, fc, fo;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 sector_t stride, size;
1980
NeilBrown2604b702006-01-06 00:20:36 -08001981 if (mddev->chunk_size == 0) {
1982 printk(KERN_ERR "md/raid10: non-zero chunk size required.\n");
1983 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 }
NeilBrown2604b702006-01-06 00:20:36 -08001985
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 nc = mddev->layout & 255;
1987 fc = (mddev->layout >> 8) & 255;
NeilBrownc93983b2006-06-26 00:27:41 -07001988 fo = mddev->layout & (1<<16);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989 if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
NeilBrownc93983b2006-06-26 00:27:41 -07001990 (mddev->layout >> 17)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n",
1992 mdname(mddev), mddev->layout);
1993 goto out;
1994 }
1995 /*
1996 * copy the already verified devices into our private RAID10
1997 * bookkeeping area. [whatever we allocate in run(),
1998 * should be freed in stop()]
1999 */
NeilBrown4443ae12006-01-06 00:20:28 -08002000 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002001 mddev->private = conf;
2002 if (!conf) {
2003 printk(KERN_ERR "raid10: couldn't allocate memory for %s\n",
2004 mdname(mddev));
2005 goto out;
2006 }
NeilBrown4443ae12006-01-06 00:20:28 -08002007 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002008 GFP_KERNEL);
2009 if (!conf->mirrors) {
2010 printk(KERN_ERR "raid10: couldn't allocate memory for %s\n",
2011 mdname(mddev));
2012 goto out_free_conf;
2013 }
NeilBrown4443ae12006-01-06 00:20:28 -08002014
2015 conf->tmppage = alloc_page(GFP_KERNEL);
2016 if (!conf->tmppage)
2017 goto out_free_conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002018
2019 conf->near_copies = nc;
2020 conf->far_copies = fc;
2021 conf->copies = nc*fc;
NeilBrownc93983b2006-06-26 00:27:41 -07002022 conf->far_offset = fo;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023 conf->chunk_mask = (sector_t)(mddev->chunk_size>>9)-1;
2024 conf->chunk_shift = ffz(~mddev->chunk_size) - 9;
NeilBrownc93983b2006-06-26 00:27:41 -07002025 if (fo)
2026 conf->stride = 1 << conf->chunk_shift;
2027 else {
2028 stride = mddev->size >> (conf->chunk_shift-1);
2029 sector_div(stride, fc);
2030 conf->stride = stride << conf->chunk_shift;
2031 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002032 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
2033 r10bio_pool_free, conf);
2034 if (!conf->r10bio_pool) {
2035 printk(KERN_ERR "raid10: couldn't allocate memory for %s\n",
2036 mdname(mddev));
2037 goto out_free_conf;
2038 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002039
2040 ITERATE_RDEV(mddev, rdev, tmp) {
2041 disk_idx = rdev->raid_disk;
2042 if (disk_idx >= mddev->raid_disks
2043 || disk_idx < 0)
2044 continue;
2045 disk = conf->mirrors + disk_idx;
2046
2047 disk->rdev = rdev;
2048
2049 blk_queue_stack_limits(mddev->queue,
2050 rdev->bdev->bd_disk->queue);
2051 /* as we don't honour merge_bvec_fn, we must never risk
2052 * violating it, so limit ->max_sector to one PAGE, as
2053 * a one page request is never in violation.
2054 */
2055 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
2056 mddev->queue->max_sectors > (PAGE_SIZE>>9))
2057 mddev->queue->max_sectors = (PAGE_SIZE>>9);
2058
2059 disk->head_position = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002060 }
2061 conf->raid_disks = mddev->raid_disks;
2062 conf->mddev = mddev;
2063 spin_lock_init(&conf->device_lock);
2064 INIT_LIST_HEAD(&conf->retry_list);
2065
2066 spin_lock_init(&conf->resync_lock);
NeilBrown0a27ec92006-01-06 00:20:13 -08002067 init_waitqueue_head(&conf->wait_barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068
NeilBrown6d508242005-09-09 16:24:03 -07002069 /* need to check that every block has at least one working mirror */
2070 if (!enough(conf)) {
2071 printk(KERN_ERR "raid10: not enough operational mirrors for %s\n",
2072 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 goto out_free_conf;
2074 }
2075
2076 mddev->degraded = 0;
2077 for (i = 0; i < conf->raid_disks; i++) {
2078
2079 disk = conf->mirrors + i;
2080
NeilBrown5fd6c1d2006-06-26 00:27:40 -07002081 if (!disk->rdev ||
NeilBrown2e333e82006-10-21 10:24:07 -07002082 !test_bit(In_sync, &disk->rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002083 disk->head_position = 0;
2084 mddev->degraded++;
2085 }
2086 }
2087
2088
2089 mddev->thread = md_register_thread(raid10d, mddev, "%s_raid10");
2090 if (!mddev->thread) {
2091 printk(KERN_ERR
2092 "raid10: couldn't allocate thread for %s\n",
2093 mdname(mddev));
2094 goto out_free_conf;
2095 }
2096
2097 printk(KERN_INFO
2098 "raid10: raid set %s active with %d out of %d devices\n",
2099 mdname(mddev), mddev->raid_disks - mddev->degraded,
2100 mddev->raid_disks);
2101 /*
2102 * Ok, everything is just fine now
2103 */
NeilBrown88388322006-06-26 00:27:50 -07002104 if (conf->far_offset) {
2105 size = mddev->size >> (conf->chunk_shift-1);
2106 size *= conf->raid_disks;
2107 size <<= conf->chunk_shift;
2108 sector_div(size, conf->far_copies);
2109 } else
2110 size = conf->stride * conf->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002111 sector_div(size, conf->near_copies);
2112 mddev->array_size = size/2;
2113 mddev->resync_max_sectors = size;
2114
NeilBrown7a5febe2005-05-16 21:53:16 -07002115 mddev->queue->unplug_fn = raid10_unplug;
2116 mddev->queue->issue_flush_fn = raid10_issue_flush;
NeilBrown0d129222006-10-03 01:15:54 -07002117 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
2118 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -07002119
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120 /* Calculate max read-ahead size.
2121 * We need to readahead at least twice a whole stripe....
2122 * maybe...
2123 */
2124 {
NeilBrown8932c2e2006-06-26 00:27:36 -07002125 int stripe = conf->raid_disks * (mddev->chunk_size / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002126 stripe /= conf->near_copies;
2127 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
2128 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
2129 }
2130
2131 if (conf->near_copies < mddev->raid_disks)
2132 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
2133 return 0;
2134
2135out_free_conf:
2136 if (conf->r10bio_pool)
2137 mempool_destroy(conf->r10bio_pool);
NeilBrown1345b1d2006-01-06 00:20:40 -08002138 safe_put_page(conf->tmppage);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002139 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140 kfree(conf);
2141 mddev->private = NULL;
2142out:
2143 return -EIO;
2144}
2145
2146static int stop(mddev_t *mddev)
2147{
2148 conf_t *conf = mddev_to_conf(mddev);
2149
2150 md_unregister_thread(mddev->thread);
2151 mddev->thread = NULL;
2152 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2153 if (conf->r10bio_pool)
2154 mempool_destroy(conf->r10bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002155 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002156 kfree(conf);
2157 mddev->private = NULL;
2158 return 0;
2159}
2160
NeilBrown6cce3b22006-01-06 00:20:16 -08002161static void raid10_quiesce(mddev_t *mddev, int state)
2162{
2163 conf_t *conf = mddev_to_conf(mddev);
2164
2165 switch(state) {
2166 case 1:
2167 raise_barrier(conf, 0);
2168 break;
2169 case 0:
2170 lower_barrier(conf);
2171 break;
2172 }
2173 if (mddev->thread) {
2174 if (mddev->bitmap)
2175 mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
2176 else
2177 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
2178 md_wakeup_thread(mddev->thread);
2179 }
2180}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002181
NeilBrown2604b702006-01-06 00:20:36 -08002182static struct mdk_personality raid10_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183{
2184 .name = "raid10",
NeilBrown2604b702006-01-06 00:20:36 -08002185 .level = 10,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186 .owner = THIS_MODULE,
2187 .make_request = make_request,
2188 .run = run,
2189 .stop = stop,
2190 .status = status,
2191 .error_handler = error,
2192 .hot_add_disk = raid10_add_disk,
2193 .hot_remove_disk= raid10_remove_disk,
2194 .spare_active = raid10_spare_active,
2195 .sync_request = sync_request,
NeilBrown6cce3b22006-01-06 00:20:16 -08002196 .quiesce = raid10_quiesce,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197};
2198
2199static int __init raid_init(void)
2200{
NeilBrown2604b702006-01-06 00:20:36 -08002201 return register_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002202}
2203
2204static void raid_exit(void)
2205{
NeilBrown2604b702006-01-06 00:20:36 -08002206 unregister_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002207}
2208
2209module_init(raid_init);
2210module_exit(raid_exit);
2211MODULE_LICENSE("GPL");
2212MODULE_ALIAS("md-personality-9"); /* RAID10 */
NeilBrownd9d166c2006-01-06 00:20:51 -08002213MODULE_ALIAS("md-raid10");
NeilBrown2604b702006-01-06 00:20:36 -08002214MODULE_ALIAS("md-level-10");