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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
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090021#include <linux/slab.h>
Stephen Rothwell25570722008-10-15 09:09:21 +110022#include <linux/delay.h>
NeilBrownbff61972009-03-31 14:33:13 +110023#include <linux/blkdev.h>
NeilBrownbff61972009-03-31 14:33:13 +110024#include <linux/seq_file.h>
NeilBrown43b2e5d2009-03-31 14:33:13 +110025#include "md.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110026#include "raid10.h"
Trela, Maciejdab8b292010-03-08 16:02:45 +110027#include "raid0.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110028#include "bitmap.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30/*
31 * RAID10 provides a combination of RAID0 and RAID1 functionality.
32 * The layout of data is defined by
33 * chunk_size
34 * raid_disks
35 * near_copies (stored in low byte of layout)
36 * far_copies (stored in second byte of layout)
NeilBrownc93983b2006-06-26 00:27:41 -070037 * far_offset (stored in bit 16 of layout )
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 *
39 * The data to be stored is divided into chunks using chunksize.
40 * Each device is divided into far_copies sections.
41 * In each section, chunks are laid out in a style similar to raid0, but
42 * near_copies copies of each chunk is stored (each on a different drive).
43 * The starting device for each section is offset near_copies from the starting
44 * device of the previous section.
NeilBrownc93983b2006-06-26 00:27:41 -070045 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 * drive.
47 * near_copies and far_copies must be at least one, and their product is at most
48 * raid_disks.
NeilBrownc93983b2006-06-26 00:27:41 -070049 *
50 * If far_offset is true, then the far_copies are handled a bit differently.
51 * The copies are still in different stripes, but instead of be very far apart
52 * on disk, there are adjacent stripes.
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 */
54
55/*
56 * Number of guaranteed r10bios in case of extreme VM load:
57 */
58#define NR_RAID10_BIOS 256
59
60static void unplug_slaves(mddev_t *mddev);
61
NeilBrown0a27ec92006-01-06 00:20:13 -080062static void allow_barrier(conf_t *conf);
63static void lower_barrier(conf_t *conf);
64
Al Virodd0fc662005-10-07 07:46:04 +010065static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
67 conf_t *conf = data;
68 r10bio_t *r10_bio;
69 int size = offsetof(struct r10bio_s, devs[conf->copies]);
70
71 /* allocate a r10bio with room for raid_disks entries in the bios array */
NeilBrown9ffae0c2006-01-06 00:20:32 -080072 r10_bio = kzalloc(size, gfp_flags);
NeilBrowned9bfdf2009-10-16 15:55:44 +110073 if (!r10_bio && conf->mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 unplug_slaves(conf->mddev);
75
76 return r10_bio;
77}
78
79static void r10bio_pool_free(void *r10_bio, void *data)
80{
81 kfree(r10_bio);
82}
83
NeilBrown0310fa22008-08-05 15:54:14 +100084/* Maximum size of each resync request */
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#define RESYNC_BLOCK_SIZE (64*1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
NeilBrown0310fa22008-08-05 15:54:14 +100087/* amount of memory to reserve for resync requests */
88#define RESYNC_WINDOW (1024*1024)
89/* maximum number of concurrent requests, memory permitting */
90#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92/*
93 * When performing a resync, we need to read and compare, so
94 * we need as many pages are there are copies.
95 * When performing a recovery, we need 2 bios, one for read,
96 * one for write (we recover only one drive per r10buf)
97 *
98 */
Al Virodd0fc662005-10-07 07:46:04 +010099static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
101 conf_t *conf = data;
102 struct page *page;
103 r10bio_t *r10_bio;
104 struct bio *bio;
105 int i, j;
106 int nalloc;
107
108 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
109 if (!r10_bio) {
110 unplug_slaves(conf->mddev);
111 return NULL;
112 }
113
114 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
115 nalloc = conf->copies; /* resync */
116 else
117 nalloc = 2; /* recovery */
118
119 /*
120 * Allocate bios.
121 */
122 for (j = nalloc ; j-- ; ) {
123 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
124 if (!bio)
125 goto out_free_bio;
126 r10_bio->devs[j].bio = bio;
127 }
128 /*
129 * Allocate RESYNC_PAGES data pages and attach them
130 * where needed.
131 */
132 for (j = 0 ; j < nalloc; j++) {
133 bio = r10_bio->devs[j].bio;
134 for (i = 0; i < RESYNC_PAGES; i++) {
135 page = alloc_page(gfp_flags);
136 if (unlikely(!page))
137 goto out_free_pages;
138
139 bio->bi_io_vec[i].bv_page = page;
140 }
141 }
142
143 return r10_bio;
144
145out_free_pages:
146 for ( ; i > 0 ; i--)
NeilBrown1345b1d2006-01-06 00:20:40 -0800147 safe_put_page(bio->bi_io_vec[i-1].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 while (j--)
149 for (i = 0; i < RESYNC_PAGES ; i++)
NeilBrown1345b1d2006-01-06 00:20:40 -0800150 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 j = -1;
152out_free_bio:
153 while ( ++j < nalloc )
154 bio_put(r10_bio->devs[j].bio);
155 r10bio_pool_free(r10_bio, conf);
156 return NULL;
157}
158
159static void r10buf_pool_free(void *__r10_bio, void *data)
160{
161 int i;
162 conf_t *conf = data;
163 r10bio_t *r10bio = __r10_bio;
164 int j;
165
166 for (j=0; j < conf->copies; j++) {
167 struct bio *bio = r10bio->devs[j].bio;
168 if (bio) {
169 for (i = 0; i < RESYNC_PAGES; i++) {
NeilBrown1345b1d2006-01-06 00:20:40 -0800170 safe_put_page(bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 bio->bi_io_vec[i].bv_page = NULL;
172 }
173 bio_put(bio);
174 }
175 }
176 r10bio_pool_free(r10bio, conf);
177}
178
179static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
180{
181 int i;
182
183 for (i = 0; i < conf->copies; i++) {
184 struct bio **bio = & r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -0800185 if (*bio && *bio != IO_BLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 bio_put(*bio);
187 *bio = NULL;
188 }
189}
190
Arjan van de Ven858119e2006-01-14 13:20:43 -0800191static void free_r10bio(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
NeilBrown070ec552009-06-16 16:54:21 +1000193 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
195 /*
196 * Wake up any possible resync thread that waits for the device
197 * to go idle.
198 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800199 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
201 put_all_bios(conf, r10_bio);
202 mempool_free(r10_bio, conf->r10bio_pool);
203}
204
Arjan van de Ven858119e2006-01-14 13:20:43 -0800205static void put_buf(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
NeilBrown070ec552009-06-16 16:54:21 +1000207 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 mempool_free(r10_bio, conf->r10buf_pool);
210
NeilBrown0a27ec92006-01-06 00:20:13 -0800211 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212}
213
214static void reschedule_retry(r10bio_t *r10_bio)
215{
216 unsigned long flags;
217 mddev_t *mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +1000218 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 spin_lock_irqsave(&conf->device_lock, flags);
221 list_add(&r10_bio->retry_list, &conf->retry_list);
NeilBrown4443ae12006-01-06 00:20:28 -0800222 conf->nr_queued ++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 spin_unlock_irqrestore(&conf->device_lock, flags);
224
Arthur Jones388667b2008-07-25 12:03:38 -0700225 /* wake up frozen array... */
226 wake_up(&conf->wait_barrier);
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 md_wakeup_thread(mddev->thread);
229}
230
231/*
232 * raid_end_bio_io() is called when we have finished servicing a mirrored
233 * operation and are ready to return a success/failure code to the buffer
234 * cache layer.
235 */
236static void raid_end_bio_io(r10bio_t *r10_bio)
237{
238 struct bio *bio = r10_bio->master_bio;
239
NeilBrown6712ecf2007-09-27 12:47:43 +0200240 bio_endio(bio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO);
242 free_r10bio(r10_bio);
243}
244
245/*
246 * Update disk head position estimator based on IRQ completion info.
247 */
248static inline void update_head_pos(int slot, r10bio_t *r10_bio)
249{
NeilBrown070ec552009-06-16 16:54:21 +1000250 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
253 r10_bio->devs[slot].addr + (r10_bio->sectors);
254}
255
NeilBrown6712ecf2007-09-27 12:47:43 +0200256static void raid10_end_read_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257{
258 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +1100259 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 int slot, dev;
NeilBrown070ec552009-06-16 16:54:21 +1000261 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264 slot = r10_bio->read_slot;
265 dev = r10_bio->devs[slot].devnum;
266 /*
267 * this branch is our 'one mirror IO has finished' event handler:
268 */
NeilBrown4443ae12006-01-06 00:20:28 -0800269 update_head_pos(slot, r10_bio);
270
271 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 /*
273 * Set R10BIO_Uptodate in our master bio, so that
274 * we will return a good error code to the higher
275 * levels even if IO on some other mirrored buffer fails.
276 *
277 * The 'master' represents the composite IO operation to
278 * user-side. So if something waits for IO, then it will
279 * wait for the 'master' bio.
280 */
281 set_bit(R10BIO_Uptodate, &r10_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 raid_end_bio_io(r10_bio);
NeilBrown4443ae12006-01-06 00:20:28 -0800283 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 /*
285 * oops, read error:
286 */
287 char b[BDEVNAME_SIZE];
288 if (printk_ratelimit())
NeilBrown128595e2010-05-03 14:47:14 +1000289 printk(KERN_ERR "md/raid10:%s: %s: rescheduling sector %llu\n",
290 mdname(conf->mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector);
292 reschedule_retry(r10_bio);
293 }
294
295 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296}
297
NeilBrown6712ecf2007-09-27 12:47:43 +0200298static void raid10_end_write_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299{
300 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +1100301 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 int slot, dev;
NeilBrown070ec552009-06-16 16:54:21 +1000303 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 for (slot = 0; slot < conf->copies; slot++)
306 if (r10_bio->devs[slot].bio == bio)
307 break;
308 dev = r10_bio->devs[slot].devnum;
309
310 /*
311 * this branch is our 'one mirror IO has finished' event handler:
312 */
NeilBrown6cce3b232006-01-06 00:20:16 -0800313 if (!uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
NeilBrown6cce3b232006-01-06 00:20:16 -0800315 /* an I/O failed, we can't clear the bitmap */
316 set_bit(R10BIO_Degraded, &r10_bio->state);
317 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 /*
319 * Set R10BIO_Uptodate in our master bio, so that
320 * we will return a good error code for to the higher
321 * levels even if IO on some other mirrored buffer fails.
322 *
323 * The 'master' represents the composite IO operation to
324 * user-side. So if something waits for IO, then it will
325 * wait for the 'master' bio.
326 */
327 set_bit(R10BIO_Uptodate, &r10_bio->state);
328
329 update_head_pos(slot, r10_bio);
330
331 /*
332 *
333 * Let's see if all mirrored write operations have finished
334 * already.
335 */
336 if (atomic_dec_and_test(&r10_bio->remaining)) {
NeilBrown6cce3b232006-01-06 00:20:16 -0800337 /* clear the bitmap if all writes complete successfully */
338 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
339 r10_bio->sectors,
340 !test_bit(R10BIO_Degraded, &r10_bio->state),
341 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 md_write_end(r10_bio->mddev);
343 raid_end_bio_io(r10_bio);
344 }
345
346 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
348
349
350/*
351 * RAID10 layout manager
352 * Aswell as the chunksize and raid_disks count, there are two
353 * parameters: near_copies and far_copies.
354 * near_copies * far_copies must be <= raid_disks.
355 * Normally one of these will be 1.
356 * If both are 1, we get raid0.
357 * If near_copies == raid_disks, we get raid1.
358 *
359 * Chunks are layed out in raid0 style with near_copies copies of the
360 * first chunk, followed by near_copies copies of the next chunk and
361 * so on.
362 * If far_copies > 1, then after 1/far_copies of the array has been assigned
363 * as described above, we start again with a device offset of near_copies.
364 * So we effectively have another copy of the whole array further down all
365 * the drives, but with blocks on different drives.
366 * With this layout, and block is never stored twice on the one device.
367 *
368 * raid10_find_phys finds the sector offset of a given virtual sector
NeilBrownc93983b2006-06-26 00:27:41 -0700369 * on each device that it is on.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 *
371 * raid10_find_virt does the reverse mapping, from a device and a
372 * sector offset to a virtual address
373 */
374
375static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio)
376{
377 int n,f;
378 sector_t sector;
379 sector_t chunk;
380 sector_t stripe;
381 int dev;
382
383 int slot = 0;
384
385 /* now calculate first sector/dev */
386 chunk = r10bio->sector >> conf->chunk_shift;
387 sector = r10bio->sector & conf->chunk_mask;
388
389 chunk *= conf->near_copies;
390 stripe = chunk;
391 dev = sector_div(stripe, conf->raid_disks);
NeilBrownc93983b2006-06-26 00:27:41 -0700392 if (conf->far_offset)
393 stripe *= conf->far_copies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 sector += stripe << conf->chunk_shift;
396
397 /* and calculate all the others */
398 for (n=0; n < conf->near_copies; n++) {
399 int d = dev;
400 sector_t s = sector;
401 r10bio->devs[slot].addr = sector;
402 r10bio->devs[slot].devnum = d;
403 slot++;
404
405 for (f = 1; f < conf->far_copies; f++) {
406 d += conf->near_copies;
407 if (d >= conf->raid_disks)
408 d -= conf->raid_disks;
409 s += conf->stride;
410 r10bio->devs[slot].devnum = d;
411 r10bio->devs[slot].addr = s;
412 slot++;
413 }
414 dev++;
415 if (dev >= conf->raid_disks) {
416 dev = 0;
417 sector += (conf->chunk_mask + 1);
418 }
419 }
420 BUG_ON(slot != conf->copies);
421}
422
423static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev)
424{
425 sector_t offset, chunk, vchunk;
426
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 offset = sector & conf->chunk_mask;
NeilBrownc93983b2006-06-26 00:27:41 -0700428 if (conf->far_offset) {
429 int fc;
430 chunk = sector >> conf->chunk_shift;
431 fc = sector_div(chunk, conf->far_copies);
432 dev -= fc * conf->near_copies;
433 if (dev < 0)
434 dev += conf->raid_disks;
435 } else {
NeilBrown64a742b2007-02-28 20:11:18 -0800436 while (sector >= conf->stride) {
NeilBrownc93983b2006-06-26 00:27:41 -0700437 sector -= conf->stride;
438 if (dev < conf->near_copies)
439 dev += conf->raid_disks - conf->near_copies;
440 else
441 dev -= conf->near_copies;
442 }
443 chunk = sector >> conf->chunk_shift;
444 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 vchunk = chunk * conf->raid_disks + dev;
446 sector_div(vchunk, conf->near_copies);
447 return (vchunk << conf->chunk_shift) + offset;
448}
449
450/**
451 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
452 * @q: request queue
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200453 * @bvm: properties of new bio
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 * @biovec: the request that could be merged to it.
455 *
456 * Return amount of bytes we can accept at this offset
457 * If near_copies == raid_disk, there are no striping issues,
458 * but in that case, the function isn't called at all.
459 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200460static int raid10_mergeable_bvec(struct request_queue *q,
461 struct bvec_merge_data *bvm,
462 struct bio_vec *biovec)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463{
464 mddev_t *mddev = q->queuedata;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200465 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 int max;
Andre Noll9d8f0362009-06-18 08:45:01 +1000467 unsigned int chunk_sectors = mddev->chunk_sectors;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200468 unsigned int bio_sectors = bvm->bi_size >> 9;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
470 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
471 if (max < 0) max = 0; /* bio_add cannot handle a negative return */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200472 if (max <= biovec->bv_len && bio_sectors == 0)
473 return biovec->bv_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 else
475 return max;
476}
477
478/*
479 * This routine returns the disk from which the requested read should
480 * be done. There is a per-array 'next expected sequential IO' sector
481 * number - if this matches on the next IO then we use the last disk.
482 * There is also a per-disk 'last know head position' sector that is
483 * maintained from IRQ contexts, both the normal and the resync IO
484 * completion handlers update this position correctly. If there is no
485 * perfect sequential match then we pick the disk whose head is closest.
486 *
487 * If there are 2 mirrors in the same 2 devices, performance degrades
488 * because position is mirror, not device based.
489 *
490 * The rdev for the device selected will have nr_pending incremented.
491 */
492
493/*
494 * FIXME: possibly should rethink readbalancing and do it differently
495 * depending on near_copies / far_copies geometry.
496 */
497static int read_balance(conf_t *conf, r10bio_t *r10_bio)
498{
NeilBrownaf3a2cd2010-05-08 08:20:17 +1000499 const sector_t this_sector = r10_bio->sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 int disk, slot, nslot;
501 const int sectors = r10_bio->sectors;
502 sector_t new_distance, current_distance;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800503 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
505 raid10_find_phys(conf, r10_bio);
506 rcu_read_lock();
507 /*
508 * Check if we can balance. We can balance on the whole
NeilBrown6cce3b232006-01-06 00:20:16 -0800509 * device if no resync is going on (recovery is ok), or below
510 * the resync window. We take the first readable disk when
511 * above the resync window.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 */
513 if (conf->mddev->recovery_cp < MaxSector
514 && (this_sector + sectors >= conf->next_resync)) {
515 /* make sure that disk is operational */
516 slot = 0;
517 disk = r10_bio->devs[slot].devnum;
518
Suzanne Woodd6065f72005-11-08 21:39:27 -0800519 while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800520 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800521 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 slot++;
523 if (slot == conf->copies) {
524 slot = 0;
525 disk = -1;
526 break;
527 }
528 disk = r10_bio->devs[slot].devnum;
529 }
530 goto rb_out;
531 }
532
533
534 /* make sure the disk is operational */
535 slot = 0;
536 disk = r10_bio->devs[slot].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800537 while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800538 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800539 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 slot ++;
541 if (slot == conf->copies) {
542 disk = -1;
543 goto rb_out;
544 }
545 disk = r10_bio->devs[slot].devnum;
546 }
547
548
NeilBrown3ec67ac2005-09-09 16:23:40 -0700549 current_distance = abs(r10_bio->devs[slot].addr -
550 conf->mirrors[disk].head_position);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800552 /* Find the disk whose head is closest,
553 * or - for far > 1 - find the closest to partition beginning */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
555 for (nslot = slot; nslot < conf->copies; nslot++) {
556 int ndisk = r10_bio->devs[nslot].devnum;
557
558
Suzanne Woodd6065f72005-11-08 21:39:27 -0800559 if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800560 r10_bio->devs[nslot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800561 !test_bit(In_sync, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 continue;
563
NeilBrown22dfdf52005-11-28 13:44:09 -0800564 /* This optimisation is debatable, and completely destroys
565 * sequential read speed for 'far copies' arrays. So only
566 * keep it for 'near' arrays, and review those later.
567 */
568 if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 disk = ndisk;
570 slot = nslot;
571 break;
572 }
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800573
574 /* for far > 1 always use the lowest address */
575 if (conf->far_copies > 1)
576 new_distance = r10_bio->devs[nslot].addr;
577 else
578 new_distance = abs(r10_bio->devs[nslot].addr -
579 conf->mirrors[ndisk].head_position);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 if (new_distance < current_distance) {
581 current_distance = new_distance;
582 disk = ndisk;
583 slot = nslot;
584 }
585 }
586
587rb_out:
588 r10_bio->read_slot = slot;
589/* conf->next_seq_sect = this_sector + sectors;*/
590
Suzanne Woodd6065f72005-11-08 21:39:27 -0800591 if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
NeilBrown29fc7e32006-02-03 03:03:41 -0800593 else
594 disk = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 rcu_read_unlock();
596
597 return disk;
598}
599
600static void unplug_slaves(mddev_t *mddev)
601{
NeilBrown070ec552009-06-16 16:54:21 +1000602 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 int i;
604
605 rcu_read_lock();
NeilBrown84707f32010-03-16 17:23:35 +1100606 for (i=0; i < conf->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800607 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800608 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200609 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
611 atomic_inc(&rdev->nr_pending);
612 rcu_read_unlock();
613
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500614 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
616 rdev_dec_pending(rdev, mddev);
617 rcu_read_lock();
618 }
619 }
620 rcu_read_unlock();
621}
622
Jens Axboe165125e2007-07-24 09:28:11 +0200623static void raid10_unplug(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624{
NeilBrown6cce3b232006-01-06 00:20:16 -0800625 mddev_t *mddev = q->queuedata;
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 unplug_slaves(q->queuedata);
NeilBrown6cce3b232006-01-06 00:20:16 -0800628 md_wakeup_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629}
630
NeilBrown0d129222006-10-03 01:15:54 -0700631static int raid10_congested(void *data, int bits)
632{
633 mddev_t *mddev = data;
NeilBrown070ec552009-06-16 16:54:21 +1000634 conf_t *conf = mddev->private;
NeilBrown0d129222006-10-03 01:15:54 -0700635 int i, ret = 0;
636
NeilBrown3fa841d2009-09-23 18:10:29 +1000637 if (mddev_congested(mddev, bits))
638 return 1;
NeilBrown0d129222006-10-03 01:15:54 -0700639 rcu_read_lock();
NeilBrown84707f32010-03-16 17:23:35 +1100640 for (i = 0; i < conf->raid_disks && ret == 0; i++) {
NeilBrown0d129222006-10-03 01:15:54 -0700641 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
642 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200643 struct request_queue *q = bdev_get_queue(rdev->bdev);
NeilBrown0d129222006-10-03 01:15:54 -0700644
645 ret |= bdi_congested(&q->backing_dev_info, bits);
646 }
647 }
648 rcu_read_unlock();
649 return ret;
650}
651
NeilBrowna35e63e2008-03-04 14:29:29 -0800652static int flush_pending_writes(conf_t *conf)
653{
654 /* Any writes that have been queued but are awaiting
655 * bitmap updates get flushed here.
656 * We return 1 if any requests were actually submitted.
657 */
658 int rv = 0;
NeilBrown0d129222006-10-03 01:15:54 -0700659
NeilBrowna35e63e2008-03-04 14:29:29 -0800660 spin_lock_irq(&conf->device_lock);
661
662 if (conf->pending_bio_list.head) {
663 struct bio *bio;
664 bio = bio_list_get(&conf->pending_bio_list);
665 blk_remove_plug(conf->mddev->queue);
666 spin_unlock_irq(&conf->device_lock);
667 /* flush any pending bitmap writes to disk
668 * before proceeding w/ I/O */
669 bitmap_unplug(conf->mddev->bitmap);
670
671 while (bio) { /* submit pending writes */
672 struct bio *next = bio->bi_next;
673 bio->bi_next = NULL;
674 generic_make_request(bio);
675 bio = next;
676 }
677 rv = 1;
678 } else
679 spin_unlock_irq(&conf->device_lock);
680 return rv;
681}
NeilBrown0a27ec92006-01-06 00:20:13 -0800682/* Barriers....
683 * Sometimes we need to suspend IO while we do something else,
684 * either some resync/recovery, or reconfigure the array.
685 * To do this we raise a 'barrier'.
686 * The 'barrier' is a counter that can be raised multiple times
687 * to count how many activities are happening which preclude
688 * normal IO.
689 * We can only raise the barrier if there is no pending IO.
690 * i.e. if nr_pending == 0.
691 * We choose only to raise the barrier if no-one is waiting for the
692 * barrier to go down. This means that as soon as an IO request
693 * is ready, no other operations which require a barrier will start
694 * until the IO request has had a chance.
695 *
696 * So: regular IO calls 'wait_barrier'. When that returns there
697 * is no backgroup IO happening, It must arrange to call
698 * allow_barrier when it has finished its IO.
699 * backgroup IO calls must call raise_barrier. Once that returns
700 * there is no normal IO happeing. It must arrange to call
701 * lower_barrier when the particular background IO completes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
NeilBrown6cce3b232006-01-06 00:20:16 -0800704static void raise_barrier(conf_t *conf, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705{
NeilBrown6cce3b232006-01-06 00:20:16 -0800706 BUG_ON(force && !conf->barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 spin_lock_irq(&conf->resync_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
NeilBrown6cce3b232006-01-06 00:20:16 -0800709 /* Wait until no block IO is waiting (unless 'force') */
710 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
NeilBrown0a27ec92006-01-06 00:20:13 -0800711 conf->resync_lock,
712 raid10_unplug(conf->mddev->queue));
713
714 /* block any new IO from starting */
715 conf->barrier++;
716
717 /* No wait for all pending IO to complete */
718 wait_event_lock_irq(conf->wait_barrier,
719 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
720 conf->resync_lock,
721 raid10_unplug(conf->mddev->queue));
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 spin_unlock_irq(&conf->resync_lock);
724}
725
NeilBrown0a27ec92006-01-06 00:20:13 -0800726static void lower_barrier(conf_t *conf)
727{
728 unsigned long flags;
729 spin_lock_irqsave(&conf->resync_lock, flags);
730 conf->barrier--;
731 spin_unlock_irqrestore(&conf->resync_lock, flags);
732 wake_up(&conf->wait_barrier);
733}
734
735static void wait_barrier(conf_t *conf)
736{
737 spin_lock_irq(&conf->resync_lock);
738 if (conf->barrier) {
739 conf->nr_waiting++;
740 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
741 conf->resync_lock,
742 raid10_unplug(conf->mddev->queue));
743 conf->nr_waiting--;
744 }
745 conf->nr_pending++;
746 spin_unlock_irq(&conf->resync_lock);
747}
748
749static void allow_barrier(conf_t *conf)
750{
751 unsigned long flags;
752 spin_lock_irqsave(&conf->resync_lock, flags);
753 conf->nr_pending--;
754 spin_unlock_irqrestore(&conf->resync_lock, flags);
755 wake_up(&conf->wait_barrier);
756}
757
NeilBrown4443ae12006-01-06 00:20:28 -0800758static void freeze_array(conf_t *conf)
759{
760 /* stop syncio and normal IO and wait for everything to
NeilBrownf1885932006-01-06 00:20:42 -0800761 * go quiet.
NeilBrown4443ae12006-01-06 00:20:28 -0800762 * We increment barrier and nr_waiting, and then
NeilBrown1c830532008-03-04 14:29:35 -0800763 * wait until nr_pending match nr_queued+1
764 * This is called in the context of one normal IO request
765 * that has failed. Thus any sync request that might be pending
766 * will be blocked by nr_pending, and we need to wait for
767 * pending IO requests to complete or be queued for re-try.
768 * Thus the number queued (nr_queued) plus this request (1)
769 * must match the number of pending IOs (nr_pending) before
770 * we continue.
NeilBrown4443ae12006-01-06 00:20:28 -0800771 */
772 spin_lock_irq(&conf->resync_lock);
773 conf->barrier++;
774 conf->nr_waiting++;
775 wait_event_lock_irq(conf->wait_barrier,
NeilBrown1c830532008-03-04 14:29:35 -0800776 conf->nr_pending == conf->nr_queued+1,
NeilBrown4443ae12006-01-06 00:20:28 -0800777 conf->resync_lock,
NeilBrowna35e63e2008-03-04 14:29:29 -0800778 ({ flush_pending_writes(conf);
779 raid10_unplug(conf->mddev->queue); }));
NeilBrown4443ae12006-01-06 00:20:28 -0800780 spin_unlock_irq(&conf->resync_lock);
781}
782
783static void unfreeze_array(conf_t *conf)
784{
785 /* reverse the effect of the freeze */
786 spin_lock_irq(&conf->resync_lock);
787 conf->barrier--;
788 conf->nr_waiting--;
789 wake_up(&conf->wait_barrier);
790 spin_unlock_irq(&conf->resync_lock);
791}
792
NeilBrown21a52c62010-04-01 15:02:13 +1100793static int make_request(mddev_t *mddev, struct bio * bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794{
NeilBrown070ec552009-06-16 16:54:21 +1000795 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 mirror_info_t *mirror;
797 r10bio_t *r10_bio;
798 struct bio *read_bio;
799 int i;
800 int chunk_sects = conf->chunk_mask + 1;
Jens Axboea3623572005-11-01 09:26:16 +0100801 const int rw = bio_data_dir(bio);
Jens Axboe1f98a132009-09-11 14:32:04 +0200802 const bool do_sync = bio_rw_flagged(bio, BIO_RW_SYNCIO);
NeilBrown6cce3b232006-01-06 00:20:16 -0800803 struct bio_list bl;
804 unsigned long flags;
Dan Williams6bfe0b42008-04-30 00:52:32 -0700805 mdk_rdev_t *blocked_rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
Jens Axboe1f98a132009-09-11 14:32:04 +0200807 if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
NeilBrowna2826aa2009-12-14 12:49:49 +1100808 md_barrier_request(mddev, bio);
NeilBrowne5dcdd82005-09-09 16:23:41 -0700809 return 0;
810 }
811
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 /* If this request crosses a chunk boundary, we need to
813 * split it. This will only happen for 1 PAGE (or less) requests.
814 */
815 if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
816 > chunk_sects &&
817 conf->near_copies < conf->raid_disks)) {
818 struct bio_pair *bp;
819 /* Sanity check -- queue functions should prevent this happening */
820 if (bio->bi_vcnt != 1 ||
821 bio->bi_idx != 0)
822 goto bad_map;
823 /* This is a one page bio that upper layers
824 * refuse to split for us, so we need to split it.
825 */
Denis ChengRq6feef532008-10-09 08:57:05 +0200826 bp = bio_split(bio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
NeilBrown21a52c62010-04-01 15:02:13 +1100828 if (make_request(mddev, &bp->bio1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 generic_make_request(&bp->bio1);
NeilBrown21a52c62010-04-01 15:02:13 +1100830 if (make_request(mddev, &bp->bio2))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 generic_make_request(&bp->bio2);
832
833 bio_pair_release(bp);
834 return 0;
835 bad_map:
NeilBrown128595e2010-05-03 14:47:14 +1000836 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
837 " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
839
NeilBrown6712ecf2007-09-27 12:47:43 +0200840 bio_io_error(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 return 0;
842 }
843
NeilBrown3d310eb2005-06-21 17:17:26 -0700844 md_write_start(mddev, bio);
NeilBrown06d91a52005-06-21 17:17:12 -0700845
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 /*
847 * Register the new request and wait if the reconstruction
848 * thread has put up a bar for new requests.
849 * Continue immediately if no resync is active currently.
850 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800851 wait_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
854
855 r10_bio->master_bio = bio;
856 r10_bio->sectors = bio->bi_size >> 9;
857
858 r10_bio->mddev = mddev;
859 r10_bio->sector = bio->bi_sector;
NeilBrown6cce3b232006-01-06 00:20:16 -0800860 r10_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
Jens Axboea3623572005-11-01 09:26:16 +0100862 if (rw == READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 /*
864 * read balancing logic:
865 */
866 int disk = read_balance(conf, r10_bio);
867 int slot = r10_bio->read_slot;
868 if (disk < 0) {
869 raid_end_bio_io(r10_bio);
870 return 0;
871 }
872 mirror = conf->mirrors + disk;
873
874 read_bio = bio_clone(bio, GFP_NOIO);
875
876 r10_bio->devs[slot].bio = read_bio;
877
878 read_bio->bi_sector = r10_bio->devs[slot].addr +
879 mirror->rdev->data_offset;
880 read_bio->bi_bdev = mirror->rdev->bdev;
881 read_bio->bi_end_io = raid10_end_read_request;
Dmitry Monakhov1ef04fe2009-09-20 05:52:25 +0400882 read_bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 read_bio->bi_private = r10_bio;
884
885 generic_make_request(read_bio);
886 return 0;
887 }
888
889 /*
890 * WRITE:
891 */
Dan Williams6bfe0b42008-04-30 00:52:32 -0700892 /* first select target devices under rcu_lock and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 * inc refcount on their rdev. Record them by setting
894 * bios[x] to bio
895 */
896 raid10_find_phys(conf, r10_bio);
Dan Williams6bfe0b42008-04-30 00:52:32 -0700897 retry_write:
Harvey Harrisoncb6969e2008-05-06 20:42:32 -0700898 blocked_rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 rcu_read_lock();
900 for (i = 0; i < conf->copies; i++) {
901 int d = r10_bio->devs[i].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800902 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
Dan Williams6bfe0b42008-04-30 00:52:32 -0700903 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
904 atomic_inc(&rdev->nr_pending);
905 blocked_rdev = rdev;
906 break;
907 }
908 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800909 atomic_inc(&rdev->nr_pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 r10_bio->devs[i].bio = bio;
NeilBrown6cce3b232006-01-06 00:20:16 -0800911 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 r10_bio->devs[i].bio = NULL;
NeilBrown6cce3b232006-01-06 00:20:16 -0800913 set_bit(R10BIO_Degraded, &r10_bio->state);
914 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 }
916 rcu_read_unlock();
917
Dan Williams6bfe0b42008-04-30 00:52:32 -0700918 if (unlikely(blocked_rdev)) {
919 /* Have to wait for this device to get unblocked, then retry */
920 int j;
921 int d;
922
923 for (j = 0; j < i; j++)
924 if (r10_bio->devs[j].bio) {
925 d = r10_bio->devs[j].devnum;
926 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
927 }
928 allow_barrier(conf);
929 md_wait_for_blocked_rdev(blocked_rdev, mddev);
930 wait_barrier(conf);
931 goto retry_write;
932 }
933
NeilBrown6cce3b232006-01-06 00:20:16 -0800934 atomic_set(&r10_bio->remaining, 0);
NeilBrown06d91a52005-06-21 17:17:12 -0700935
NeilBrown6cce3b232006-01-06 00:20:16 -0800936 bio_list_init(&bl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 for (i = 0; i < conf->copies; i++) {
938 struct bio *mbio;
939 int d = r10_bio->devs[i].devnum;
940 if (!r10_bio->devs[i].bio)
941 continue;
942
943 mbio = bio_clone(bio, GFP_NOIO);
944 r10_bio->devs[i].bio = mbio;
945
946 mbio->bi_sector = r10_bio->devs[i].addr+
947 conf->mirrors[d].rdev->data_offset;
948 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
949 mbio->bi_end_io = raid10_end_write_request;
Dmitry Monakhov1ef04fe2009-09-20 05:52:25 +0400950 mbio->bi_rw = WRITE | (do_sync << BIO_RW_SYNCIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 mbio->bi_private = r10_bio;
952
953 atomic_inc(&r10_bio->remaining);
NeilBrown6cce3b232006-01-06 00:20:16 -0800954 bio_list_add(&bl, mbio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 }
956
Arne Redlichf6f953a2007-07-31 00:37:57 -0700957 if (unlikely(!atomic_read(&r10_bio->remaining))) {
958 /* the array is dead */
959 md_write_end(mddev);
960 raid_end_bio_io(r10_bio);
961 return 0;
962 }
963
NeilBrown6cce3b232006-01-06 00:20:16 -0800964 bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0);
965 spin_lock_irqsave(&conf->device_lock, flags);
966 bio_list_merge(&conf->pending_bio_list, &bl);
967 blk_plug_device(mddev->queue);
968 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
NeilBrowna35e63e2008-03-04 14:29:29 -0800970 /* In case raid10d snuck in to freeze_array */
971 wake_up(&conf->wait_barrier);
972
Lars Ellenberge3881a62007-01-10 23:15:37 -0800973 if (do_sync)
974 md_wakeup_thread(mddev->thread);
975
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 return 0;
977}
978
979static void status(struct seq_file *seq, mddev_t *mddev)
980{
NeilBrown070ec552009-06-16 16:54:21 +1000981 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 int i;
983
984 if (conf->near_copies < conf->raid_disks)
Andre Noll9d8f0362009-06-18 08:45:01 +1000985 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 if (conf->near_copies > 1)
987 seq_printf(seq, " %d near-copies", conf->near_copies);
NeilBrownc93983b2006-06-26 00:27:41 -0700988 if (conf->far_copies > 1) {
989 if (conf->far_offset)
990 seq_printf(seq, " %d offset-copies", conf->far_copies);
991 else
992 seq_printf(seq, " %d far-copies", conf->far_copies);
993 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
NeilBrown76186dd2006-10-03 01:15:48 -0700995 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 for (i = 0; i < conf->raid_disks; i++)
997 seq_printf(seq, "%s",
998 conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800999 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 seq_printf(seq, "]");
1001}
1002
1003static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1004{
1005 char b[BDEVNAME_SIZE];
NeilBrown070ec552009-06-16 16:54:21 +10001006 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007
1008 /*
1009 * If it is not operational, then we have already marked it as dead
1010 * else if it is the last working disks, ignore the error, let the
1011 * next level up know.
1012 * else mark the drive as failed
1013 */
NeilBrownb2d444d2005-11-08 21:39:31 -08001014 if (test_bit(In_sync, &rdev->flags)
NeilBrown76186dd2006-10-03 01:15:48 -07001015 && conf->raid_disks-mddev->degraded == 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 /*
1017 * Don't fail the drive, just return an IO error.
1018 * The test should really be more sophisticated than
1019 * "working_disks == 1", but it isn't critical, and
1020 * can wait until we do more sophisticated "is the drive
1021 * really dead" tests...
1022 */
1023 return;
NeilBrownc04be0a2006-10-03 01:15:53 -07001024 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1025 unsigned long flags;
1026 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001028 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 /*
1030 * if recovery is running, make sure it aborts.
1031 */
NeilBrowndfc70642008-05-23 13:04:39 -07001032 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001034 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -07001035 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown128595e2010-05-03 14:47:14 +10001036 printk(KERN_ALERT "md/raid10:%s: Disk failure on %s, disabling device.\n"
1037 KERN_ALERT "md/raid10:%s: Operation continuing on %d devices.\n",
1038 mdname(mddev), bdevname(rdev->bdev, b),
1039 mdname(mddev), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040}
1041
1042static void print_conf(conf_t *conf)
1043{
1044 int i;
1045 mirror_info_t *tmp;
1046
NeilBrown128595e2010-05-03 14:47:14 +10001047 printk(KERN_DEBUG "RAID10 conf printout:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 if (!conf) {
NeilBrown128595e2010-05-03 14:47:14 +10001049 printk(KERN_DEBUG "(!conf)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 return;
1051 }
NeilBrown128595e2010-05-03 14:47:14 +10001052 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 conf->raid_disks);
1054
1055 for (i = 0; i < conf->raid_disks; i++) {
1056 char b[BDEVNAME_SIZE];
1057 tmp = conf->mirrors + i;
1058 if (tmp->rdev)
NeilBrown128595e2010-05-03 14:47:14 +10001059 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08001060 i, !test_bit(In_sync, &tmp->rdev->flags),
1061 !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 bdevname(tmp->rdev->bdev,b));
1063 }
1064}
1065
1066static void close_sync(conf_t *conf)
1067{
NeilBrown0a27ec92006-01-06 00:20:13 -08001068 wait_barrier(conf);
1069 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
1071 mempool_destroy(conf->r10buf_pool);
1072 conf->r10buf_pool = NULL;
1073}
1074
NeilBrown6d508242005-09-09 16:24:03 -07001075/* check if there are enough drives for
1076 * every block to appear on atleast one
1077 */
1078static int enough(conf_t *conf)
1079{
1080 int first = 0;
1081
1082 do {
1083 int n = conf->copies;
1084 int cnt = 0;
1085 while (n--) {
1086 if (conf->mirrors[first].rdev)
1087 cnt++;
1088 first = (first+1) % conf->raid_disks;
1089 }
1090 if (cnt == 0)
1091 return 0;
1092 } while (first != 0);
1093 return 1;
1094}
1095
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096static int raid10_spare_active(mddev_t *mddev)
1097{
1098 int i;
1099 conf_t *conf = mddev->private;
1100 mirror_info_t *tmp;
1101
1102 /*
1103 * Find all non-in_sync disks within the RAID10 configuration
1104 * and mark them in_sync
1105 */
1106 for (i = 0; i < conf->raid_disks; i++) {
1107 tmp = conf->mirrors + i;
1108 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08001109 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07001110 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
1111 unsigned long flags;
1112 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07001114 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 }
1116 }
1117
1118 print_conf(conf);
1119 return 0;
1120}
1121
1122
1123static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1124{
1125 conf_t *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10001126 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 int mirror;
1128 mirror_info_t *p;
Neil Brown6c2fce22008-06-28 08:31:31 +10001129 int first = 0;
NeilBrown84707f32010-03-16 17:23:35 +11001130 int last = conf->raid_disks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131
1132 if (mddev->recovery_cp < MaxSector)
1133 /* only hot-add to in-sync arrays, as recovery is
1134 * very different from resync
1135 */
Neil Brown199050e2008-06-28 08:31:33 +10001136 return -EBUSY;
NeilBrown6d508242005-09-09 16:24:03 -07001137 if (!enough(conf))
Neil Brown199050e2008-06-28 08:31:33 +10001138 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
NeilBrowna53a6c82008-11-06 17:28:20 +11001140 if (rdev->raid_disk >= 0)
Neil Brown6c2fce22008-06-28 08:31:31 +10001141 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142
NeilBrown6cce3b232006-01-06 00:20:16 -08001143 if (rdev->saved_raid_disk >= 0 &&
Neil Brown6c2fce22008-06-28 08:31:31 +10001144 rdev->saved_raid_disk >= first &&
NeilBrown6cce3b232006-01-06 00:20:16 -08001145 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1146 mirror = rdev->saved_raid_disk;
1147 else
Neil Brown6c2fce22008-06-28 08:31:31 +10001148 mirror = first;
1149 for ( ; mirror <= last ; mirror++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 if ( !(p=conf->mirrors+mirror)->rdev) {
1151
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10001152 disk_stack_limits(mddev->gendisk, rdev->bdev,
1153 rdev->data_offset << 9);
NeilBrown627a2d32010-03-08 16:44:38 +11001154 /* as we don't honour merge_bvec_fn, we must
1155 * never risk violating it, so limit
1156 * ->max_segments to one lying with a single
1157 * page, as a one page request is never in
1158 * violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 */
NeilBrown627a2d32010-03-08 16:44:38 +11001160 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1161 blk_queue_max_segments(mddev->queue, 1);
1162 blk_queue_segment_boundary(mddev->queue,
1163 PAGE_CACHE_SIZE - 1);
1164 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165
1166 p->head_position = 0;
1167 rdev->raid_disk = mirror;
Neil Brown199050e2008-06-28 08:31:33 +10001168 err = 0;
NeilBrown6cce3b232006-01-06 00:20:16 -08001169 if (rdev->saved_raid_disk != mirror)
1170 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08001171 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 break;
1173 }
1174
Andre Nollac5e7112009-08-03 10:59:47 +10001175 md_integrity_add_rdev(rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 print_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10001177 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178}
1179
1180static int raid10_remove_disk(mddev_t *mddev, int number)
1181{
1182 conf_t *conf = mddev->private;
1183 int err = 0;
1184 mdk_rdev_t *rdev;
1185 mirror_info_t *p = conf->mirrors+ number;
1186
1187 print_conf(conf);
1188 rdev = p->rdev;
1189 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08001190 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 atomic_read(&rdev->nr_pending)) {
1192 err = -EBUSY;
1193 goto abort;
1194 }
NeilBrowndfc70642008-05-23 13:04:39 -07001195 /* Only remove faulty devices in recovery
1196 * is not possible.
1197 */
1198 if (!test_bit(Faulty, &rdev->flags) &&
1199 enough(conf)) {
1200 err = -EBUSY;
1201 goto abort;
1202 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07001204 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 if (atomic_read(&rdev->nr_pending)) {
1206 /* lost the race, try later */
1207 err = -EBUSY;
1208 p->rdev = rdev;
Andre Nollac5e7112009-08-03 10:59:47 +10001209 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 }
Andre Nollac5e7112009-08-03 10:59:47 +10001211 md_integrity_register(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 }
1213abort:
1214
1215 print_conf(conf);
1216 return err;
1217}
1218
1219
NeilBrown6712ecf2007-09-27 12:47:43 +02001220static void end_sync_read(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221{
H Hartley Sweeten7b928132010-03-08 16:02:40 +11001222 r10bio_t *r10_bio = bio->bi_private;
NeilBrown070ec552009-06-16 16:54:21 +10001223 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 int i,d;
1225
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 for (i=0; i<conf->copies; i++)
1227 if (r10_bio->devs[i].bio == bio)
1228 break;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001229 BUG_ON(i == conf->copies);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 update_head_pos(i, r10_bio);
1231 d = r10_bio->devs[i].devnum;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001232
1233 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1234 set_bit(R10BIO_Uptodate, &r10_bio->state);
NeilBrown4dbcdc72006-01-06 00:20:52 -08001235 else {
1236 atomic_add(r10_bio->sectors,
1237 &conf->mirrors[d].rdev->corrected_errors);
1238 if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
1239 md_error(r10_bio->mddev,
1240 conf->mirrors[d].rdev);
1241 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242
1243 /* for reconstruct, we always reschedule after a read.
1244 * for resync, only after all reads
1245 */
NeilBrown73d5c382009-02-25 13:18:47 +11001246 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1248 atomic_dec_and_test(&r10_bio->remaining)) {
1249 /* we have read all the blocks,
1250 * do the comparison in process context in raid10d
1251 */
1252 reschedule_retry(r10_bio);
1253 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254}
1255
NeilBrown6712ecf2007-09-27 12:47:43 +02001256static void end_sync_write(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257{
1258 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +11001259 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 mddev_t *mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +10001261 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 int i,d;
1263
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264 for (i = 0; i < conf->copies; i++)
1265 if (r10_bio->devs[i].bio == bio)
1266 break;
1267 d = r10_bio->devs[i].devnum;
1268
1269 if (!uptodate)
1270 md_error(mddev, conf->mirrors[d].rdev);
NeilBrowndfc70642008-05-23 13:04:39 -07001271
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 update_head_pos(i, r10_bio);
1273
NeilBrown73d5c382009-02-25 13:18:47 +11001274 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 while (atomic_dec_and_test(&r10_bio->remaining)) {
1276 if (r10_bio->master_bio == NULL) {
1277 /* the primary of several recovery bios */
NeilBrown73d5c382009-02-25 13:18:47 +11001278 sector_t s = r10_bio->sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 put_buf(r10_bio);
NeilBrown73d5c382009-02-25 13:18:47 +11001280 md_done_sync(mddev, s, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 break;
1282 } else {
1283 r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio;
1284 put_buf(r10_bio);
1285 r10_bio = r10_bio2;
1286 }
1287 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288}
1289
1290/*
1291 * Note: sync and recover and handled very differently for raid10
1292 * This code is for resync.
1293 * For resync, we read through virtual addresses and read all blocks.
1294 * If there is any error, we schedule a write. The lowest numbered
1295 * drive is authoritative.
1296 * However requests come for physical address, so we need to map.
1297 * For every physical address there are raid_disks/copies virtual addresses,
1298 * which is always are least one, but is not necessarly an integer.
1299 * This means that a physical address can span multiple chunks, so we may
1300 * have to submit multiple io requests for a single sync request.
1301 */
1302/*
1303 * We check if all blocks are in-sync and only write to blocks that
1304 * aren't in sync
1305 */
1306static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1307{
NeilBrown070ec552009-06-16 16:54:21 +10001308 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 int i, first;
1310 struct bio *tbio, *fbio;
1311
1312 atomic_set(&r10_bio->remaining, 1);
1313
1314 /* find the first device with a block */
1315 for (i=0; i<conf->copies; i++)
1316 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
1317 break;
1318
1319 if (i == conf->copies)
1320 goto done;
1321
1322 first = i;
1323 fbio = r10_bio->devs[i].bio;
1324
1325 /* now find blocks with errors */
NeilBrown0eb3ff12006-01-06 00:20:29 -08001326 for (i=0 ; i < conf->copies ; i++) {
1327 int j, d;
1328 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 tbio = r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001331
1332 if (tbio->bi_end_io != end_sync_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 continue;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001334 if (i == first)
1335 continue;
1336 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
1337 /* We know that the bi_io_vec layout is the same for
1338 * both 'first' and 'i', so we just compare them.
1339 * All vec entries are PAGE_SIZE;
1340 */
1341 for (j = 0; j < vcnt; j++)
1342 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
1343 page_address(tbio->bi_io_vec[j].bv_page),
1344 PAGE_SIZE))
1345 break;
1346 if (j == vcnt)
1347 continue;
1348 mddev->resync_mismatches += r10_bio->sectors;
1349 }
NeilBrown18f08812006-01-06 00:20:25 -08001350 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1351 /* Don't fix anything. */
1352 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 /* Ok, we need to write this bio
1354 * First we need to fixup bv_offset, bv_len and
1355 * bi_vecs, as the read request might have corrupted these
1356 */
1357 tbio->bi_vcnt = vcnt;
1358 tbio->bi_size = r10_bio->sectors << 9;
1359 tbio->bi_idx = 0;
1360 tbio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1362 tbio->bi_flags |= 1 << BIO_UPTODATE;
1363 tbio->bi_next = NULL;
1364 tbio->bi_rw = WRITE;
1365 tbio->bi_private = r10_bio;
1366 tbio->bi_sector = r10_bio->devs[i].addr;
1367
1368 for (j=0; j < vcnt ; j++) {
1369 tbio->bi_io_vec[j].bv_offset = 0;
1370 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
1371
1372 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1373 page_address(fbio->bi_io_vec[j].bv_page),
1374 PAGE_SIZE);
1375 }
1376 tbio->bi_end_io = end_sync_write;
1377
1378 d = r10_bio->devs[i].devnum;
1379 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1380 atomic_inc(&r10_bio->remaining);
1381 md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
1382
1383 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
1384 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1385 generic_make_request(tbio);
1386 }
1387
1388done:
1389 if (atomic_dec_and_test(&r10_bio->remaining)) {
1390 md_done_sync(mddev, r10_bio->sectors, 1);
1391 put_buf(r10_bio);
1392 }
1393}
1394
1395/*
1396 * Now for the recovery code.
1397 * Recovery happens across physical sectors.
1398 * We recover all non-is_sync drives by finding the virtual address of
1399 * each, and then choose a working drive that also has that virt address.
1400 * There is a separate r10_bio for each non-in_sync drive.
1401 * Only the first two slots are in use. The first for reading,
1402 * The second for writing.
1403 *
1404 */
1405
1406static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1407{
NeilBrown070ec552009-06-16 16:54:21 +10001408 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 int i, d;
1410 struct bio *bio, *wbio;
1411
1412
1413 /* move the pages across to the second bio
1414 * and submit the write request
1415 */
1416 bio = r10_bio->devs[0].bio;
1417 wbio = r10_bio->devs[1].bio;
1418 for (i=0; i < wbio->bi_vcnt; i++) {
1419 struct page *p = bio->bi_io_vec[i].bv_page;
1420 bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page;
1421 wbio->bi_io_vec[i].bv_page = p;
1422 }
1423 d = r10_bio->devs[1].devnum;
1424
1425 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1426 md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
NeilBrown0eb3ff12006-01-06 00:20:29 -08001427 if (test_bit(R10BIO_Uptodate, &r10_bio->state))
1428 generic_make_request(wbio);
1429 else
NeilBrown6712ecf2007-09-27 12:47:43 +02001430 bio_endio(wbio, -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431}
1432
1433
1434/*
Robert Becker1e509152009-12-14 12:49:58 +11001435 * Used by fix_read_error() to decay the per rdev read_errors.
1436 * We halve the read error count for every hour that has elapsed
1437 * since the last recorded read error.
1438 *
1439 */
1440static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
1441{
1442 struct timespec cur_time_mon;
1443 unsigned long hours_since_last;
1444 unsigned int read_errors = atomic_read(&rdev->read_errors);
1445
1446 ktime_get_ts(&cur_time_mon);
1447
1448 if (rdev->last_read_error.tv_sec == 0 &&
1449 rdev->last_read_error.tv_nsec == 0) {
1450 /* first time we've seen a read error */
1451 rdev->last_read_error = cur_time_mon;
1452 return;
1453 }
1454
1455 hours_since_last = (cur_time_mon.tv_sec -
1456 rdev->last_read_error.tv_sec) / 3600;
1457
1458 rdev->last_read_error = cur_time_mon;
1459
1460 /*
1461 * if hours_since_last is > the number of bits in read_errors
1462 * just set read errors to 0. We do this to avoid
1463 * overflowing the shift of read_errors by hours_since_last.
1464 */
1465 if (hours_since_last >= 8 * sizeof(read_errors))
1466 atomic_set(&rdev->read_errors, 0);
1467 else
1468 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
1469}
1470
1471/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472 * This is a kernel thread which:
1473 *
1474 * 1. Retries failed read operations on working mirrors.
1475 * 2. Updates the raid superblock when problems encounter.
NeilBrown6814d532006-10-03 01:15:45 -07001476 * 3. Performs writes following reads for array synchronising.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 */
1478
NeilBrown6814d532006-10-03 01:15:45 -07001479static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
1480{
1481 int sect = 0; /* Offset from r10_bio->sector */
1482 int sectors = r10_bio->sectors;
1483 mdk_rdev_t*rdev;
Robert Becker1e509152009-12-14 12:49:58 +11001484 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
1485
1486 rcu_read_lock();
1487 {
1488 int d = r10_bio->devs[r10_bio->read_slot].devnum;
1489 char b[BDEVNAME_SIZE];
1490 int cur_read_error_count = 0;
1491
1492 rdev = rcu_dereference(conf->mirrors[d].rdev);
1493 bdevname(rdev->bdev, b);
1494
1495 if (test_bit(Faulty, &rdev->flags)) {
1496 rcu_read_unlock();
1497 /* drive has already been failed, just ignore any
1498 more fix_read_error() attempts */
1499 return;
1500 }
1501
1502 check_decay_read_errors(mddev, rdev);
1503 atomic_inc(&rdev->read_errors);
1504 cur_read_error_count = atomic_read(&rdev->read_errors);
1505 if (cur_read_error_count > max_read_errors) {
1506 rcu_read_unlock();
1507 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001508 "md/raid10:%s: %s: Raid device exceeded "
Robert Becker1e509152009-12-14 12:49:58 +11001509 "read_error threshold "
1510 "[cur %d:max %d]\n",
NeilBrown128595e2010-05-03 14:47:14 +10001511 mdname(mddev),
Robert Becker1e509152009-12-14 12:49:58 +11001512 b, cur_read_error_count, max_read_errors);
1513 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001514 "md/raid10:%s: %s: Failing raid "
1515 "device\n", mdname(mddev), b);
Robert Becker1e509152009-12-14 12:49:58 +11001516 md_error(mddev, conf->mirrors[d].rdev);
1517 return;
1518 }
1519 }
1520 rcu_read_unlock();
1521
NeilBrown6814d532006-10-03 01:15:45 -07001522 while(sectors) {
1523 int s = sectors;
1524 int sl = r10_bio->read_slot;
1525 int success = 0;
1526 int start;
1527
1528 if (s > (PAGE_SIZE>>9))
1529 s = PAGE_SIZE >> 9;
1530
1531 rcu_read_lock();
1532 do {
1533 int d = r10_bio->devs[sl].devnum;
1534 rdev = rcu_dereference(conf->mirrors[d].rdev);
1535 if (rdev &&
1536 test_bit(In_sync, &rdev->flags)) {
1537 atomic_inc(&rdev->nr_pending);
1538 rcu_read_unlock();
1539 success = sync_page_io(rdev->bdev,
1540 r10_bio->devs[sl].addr +
1541 sect + rdev->data_offset,
1542 s<<9,
1543 conf->tmppage, READ);
1544 rdev_dec_pending(rdev, mddev);
1545 rcu_read_lock();
1546 if (success)
1547 break;
1548 }
1549 sl++;
1550 if (sl == conf->copies)
1551 sl = 0;
1552 } while (!success && sl != r10_bio->read_slot);
1553 rcu_read_unlock();
1554
1555 if (!success) {
1556 /* Cannot read from anywhere -- bye bye array */
1557 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
1558 md_error(mddev, conf->mirrors[dn].rdev);
1559 break;
1560 }
1561
1562 start = sl;
1563 /* write it back and re-read */
1564 rcu_read_lock();
1565 while (sl != r10_bio->read_slot) {
Robert Becker67b8dc42009-12-14 12:49:57 +11001566 char b[BDEVNAME_SIZE];
NeilBrown6814d532006-10-03 01:15:45 -07001567 int d;
1568 if (sl==0)
1569 sl = conf->copies;
1570 sl--;
1571 d = r10_bio->devs[sl].devnum;
1572 rdev = rcu_dereference(conf->mirrors[d].rdev);
1573 if (rdev &&
1574 test_bit(In_sync, &rdev->flags)) {
1575 atomic_inc(&rdev->nr_pending);
1576 rcu_read_unlock();
1577 atomic_add(s, &rdev->corrected_errors);
1578 if (sync_page_io(rdev->bdev,
1579 r10_bio->devs[sl].addr +
1580 sect + rdev->data_offset,
1581 s<<9, conf->tmppage, WRITE)
Robert Becker67b8dc42009-12-14 12:49:57 +11001582 == 0) {
NeilBrown6814d532006-10-03 01:15:45 -07001583 /* Well, this device is dead */
Robert Becker67b8dc42009-12-14 12:49:57 +11001584 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001585 "md/raid10:%s: read correction "
Robert Becker67b8dc42009-12-14 12:49:57 +11001586 "write failed"
1587 " (%d sectors at %llu on %s)\n",
1588 mdname(mddev), s,
1589 (unsigned long long)(sect+
1590 rdev->data_offset),
1591 bdevname(rdev->bdev, b));
NeilBrown128595e2010-05-03 14:47:14 +10001592 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
Robert Becker67b8dc42009-12-14 12:49:57 +11001593 "drive\n",
NeilBrown128595e2010-05-03 14:47:14 +10001594 mdname(mddev),
Robert Becker67b8dc42009-12-14 12:49:57 +11001595 bdevname(rdev->bdev, b));
NeilBrown6814d532006-10-03 01:15:45 -07001596 md_error(mddev, rdev);
Robert Becker67b8dc42009-12-14 12:49:57 +11001597 }
NeilBrown6814d532006-10-03 01:15:45 -07001598 rdev_dec_pending(rdev, mddev);
1599 rcu_read_lock();
1600 }
1601 }
1602 sl = start;
1603 while (sl != r10_bio->read_slot) {
1604 int d;
1605 if (sl==0)
1606 sl = conf->copies;
1607 sl--;
1608 d = r10_bio->devs[sl].devnum;
1609 rdev = rcu_dereference(conf->mirrors[d].rdev);
1610 if (rdev &&
1611 test_bit(In_sync, &rdev->flags)) {
1612 char b[BDEVNAME_SIZE];
1613 atomic_inc(&rdev->nr_pending);
1614 rcu_read_unlock();
1615 if (sync_page_io(rdev->bdev,
1616 r10_bio->devs[sl].addr +
1617 sect + rdev->data_offset,
Robert Becker67b8dc42009-12-14 12:49:57 +11001618 s<<9, conf->tmppage,
1619 READ) == 0) {
NeilBrown6814d532006-10-03 01:15:45 -07001620 /* Well, this device is dead */
Robert Becker67b8dc42009-12-14 12:49:57 +11001621 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001622 "md/raid10:%s: unable to read back "
Robert Becker67b8dc42009-12-14 12:49:57 +11001623 "corrected sectors"
1624 " (%d sectors at %llu on %s)\n",
1625 mdname(mddev), s,
1626 (unsigned long long)(sect+
1627 rdev->data_offset),
1628 bdevname(rdev->bdev, b));
NeilBrown128595e2010-05-03 14:47:14 +10001629 printk(KERN_NOTICE "md/raid10:%s: %s: failing drive\n",
1630 mdname(mddev),
Robert Becker67b8dc42009-12-14 12:49:57 +11001631 bdevname(rdev->bdev, b));
1632
NeilBrown6814d532006-10-03 01:15:45 -07001633 md_error(mddev, rdev);
Robert Becker67b8dc42009-12-14 12:49:57 +11001634 } else {
NeilBrown6814d532006-10-03 01:15:45 -07001635 printk(KERN_INFO
NeilBrown128595e2010-05-03 14:47:14 +10001636 "md/raid10:%s: read error corrected"
NeilBrown6814d532006-10-03 01:15:45 -07001637 " (%d sectors at %llu on %s)\n",
1638 mdname(mddev), s,
Randy Dunlap969b7552006-10-28 10:38:32 -07001639 (unsigned long long)(sect+
1640 rdev->data_offset),
NeilBrown6814d532006-10-03 01:15:45 -07001641 bdevname(rdev->bdev, b));
Robert Becker67b8dc42009-12-14 12:49:57 +11001642 }
NeilBrown6814d532006-10-03 01:15:45 -07001643
1644 rdev_dec_pending(rdev, mddev);
1645 rcu_read_lock();
1646 }
1647 }
1648 rcu_read_unlock();
1649
1650 sectors -= s;
1651 sect += s;
1652 }
1653}
1654
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655static void raid10d(mddev_t *mddev)
1656{
1657 r10bio_t *r10_bio;
1658 struct bio *bio;
1659 unsigned long flags;
NeilBrown070ec552009-06-16 16:54:21 +10001660 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 struct list_head *head = &conf->retry_list;
1662 int unplug=0;
1663 mdk_rdev_t *rdev;
1664
1665 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666
1667 for (;;) {
1668 char b[BDEVNAME_SIZE];
NeilBrowna35e63e2008-03-04 14:29:29 -08001669
1670 unplug += flush_pending_writes(conf);
1671
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrowna35e63e2008-03-04 14:29:29 -08001673 if (list_empty(head)) {
NeilBrown6cce3b232006-01-06 00:20:16 -08001674 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 break;
NeilBrowna35e63e2008-03-04 14:29:29 -08001676 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 r10_bio = list_entry(head->prev, r10bio_t, retry_list);
1678 list_del(head->prev);
NeilBrown4443ae12006-01-06 00:20:28 -08001679 conf->nr_queued--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 spin_unlock_irqrestore(&conf->device_lock, flags);
1681
1682 mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +10001683 conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 if (test_bit(R10BIO_IsSync, &r10_bio->state)) {
1685 sync_request_write(mddev, r10_bio);
1686 unplug = 1;
1687 } else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) {
1688 recovery_request_write(mddev, r10_bio);
1689 unplug = 1;
1690 } else {
1691 int mirror;
NeilBrown4443ae12006-01-06 00:20:28 -08001692 /* we got a read error. Maybe the drive is bad. Maybe just
1693 * the block and we can fix it.
1694 * We freeze all other IO, and try reading the block from
1695 * other devices. When we find one, we re-write
1696 * and check it that fixes the read error.
1697 * This is all done synchronously while the array is
1698 * frozen.
1699 */
NeilBrown6814d532006-10-03 01:15:45 -07001700 if (mddev->ro == 0) {
1701 freeze_array(conf);
1702 fix_read_error(conf, mddev, r10_bio);
1703 unfreeze_array(conf);
NeilBrown4443ae12006-01-06 00:20:28 -08001704 }
1705
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 bio = r10_bio->devs[r10_bio->read_slot].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001707 r10_bio->devs[r10_bio->read_slot].bio =
1708 mddev->ro ? IO_BLOCKED : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709 mirror = read_balance(conf, r10_bio);
1710 if (mirror == -1) {
NeilBrown128595e2010-05-03 14:47:14 +10001711 printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 " read error for block %llu\n",
NeilBrown128595e2010-05-03 14:47:14 +10001713 mdname(mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 bdevname(bio->bi_bdev,b),
1715 (unsigned long long)r10_bio->sector);
1716 raid_end_bio_io(r10_bio);
Maik Hampel14e71342007-07-31 00:37:57 -07001717 bio_put(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 } else {
Jens Axboe1f98a132009-09-11 14:32:04 +02001719 const bool do_sync = bio_rw_flagged(r10_bio->master_bio, BIO_RW_SYNCIO);
Maik Hampel14e71342007-07-31 00:37:57 -07001720 bio_put(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721 rdev = conf->mirrors[mirror].rdev;
1722 if (printk_ratelimit())
NeilBrown128595e2010-05-03 14:47:14 +10001723 printk(KERN_ERR "md/raid10:%s: %s: redirecting sector %llu to"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 " another mirror\n",
NeilBrown128595e2010-05-03 14:47:14 +10001725 mdname(mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 bdevname(rdev->bdev,b),
1727 (unsigned long long)r10_bio->sector);
1728 bio = bio_clone(r10_bio->master_bio, GFP_NOIO);
1729 r10_bio->devs[r10_bio->read_slot].bio = bio;
1730 bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr
1731 + rdev->data_offset;
1732 bio->bi_bdev = rdev->bdev;
Dmitry Monakhov1ef04fe2009-09-20 05:52:25 +04001733 bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734 bio->bi_private = r10_bio;
1735 bio->bi_end_io = raid10_end_read_request;
1736 unplug = 1;
1737 generic_make_request(bio);
1738 }
1739 }
NeilBrown1d9d5242009-10-16 15:55:32 +11001740 cond_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 if (unplug)
1743 unplug_slaves(mddev);
1744}
1745
1746
1747static int init_resync(conf_t *conf)
1748{
1749 int buffs;
1750
1751 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001752 BUG_ON(conf->r10buf_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
1754 if (!conf->r10buf_pool)
1755 return -ENOMEM;
1756 conf->next_resync = 0;
1757 return 0;
1758}
1759
1760/*
1761 * perform a "sync" on one "block"
1762 *
1763 * We need to make sure that no normal I/O request - particularly write
1764 * requests - conflict with active sync requests.
1765 *
1766 * This is achieved by tracking pending requests and a 'barrier' concept
1767 * that can be installed to exclude normal IO requests.
1768 *
1769 * Resync and recovery are handled very differently.
1770 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
1771 *
1772 * For resync, we iterate over virtual addresses, read all copies,
1773 * and update if there are differences. If only one copy is live,
1774 * skip it.
1775 * For recovery, we iterate over physical addresses, read a good
1776 * value for each non-in_sync drive, and over-write.
1777 *
1778 * So, for recovery we may have several outstanding complex requests for a
1779 * given address, one for each out-of-sync device. We model this by allocating
1780 * a number of r10_bio structures, one for each out-of-sync device.
1781 * As we setup these structures, we collect all bio's together into a list
1782 * which we then process collectively to add pages, and then process again
1783 * to pass to generic_make_request.
1784 *
1785 * The r10_bio structures are linked using a borrowed master_bio pointer.
1786 * This link is counted in ->remaining. When the r10_bio that points to NULL
1787 * has its remaining count decremented to 0, the whole complex operation
1788 * is complete.
1789 *
1790 */
1791
NeilBrown57afd892005-06-21 17:17:13 -07001792static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793{
NeilBrown070ec552009-06-16 16:54:21 +10001794 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 r10bio_t *r10_bio;
1796 struct bio *biolist = NULL, *bio;
1797 sector_t max_sector, nr_sectors;
1798 int disk;
1799 int i;
NeilBrown6cce3b232006-01-06 00:20:16 -08001800 int max_sync;
1801 int sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802
1803 sector_t sectors_skipped = 0;
1804 int chunks_skipped = 0;
1805
1806 if (!conf->r10buf_pool)
1807 if (init_resync(conf))
NeilBrown57afd892005-06-21 17:17:13 -07001808 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001809
1810 skipped:
Andre Noll58c0fed2009-03-31 14:33:13 +11001811 max_sector = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1813 max_sector = mddev->resync_max_sectors;
1814 if (sector_nr >= max_sector) {
NeilBrown6cce3b232006-01-06 00:20:16 -08001815 /* If we aborted, we need to abort the
1816 * sync on the 'current' bitmap chucks (there can
1817 * be several when recovering multiple devices).
1818 * as we may have started syncing it but not finished.
1819 * We can find the current address in
1820 * mddev->curr_resync, but for recovery,
1821 * we need to convert that to several
1822 * virtual addresses.
1823 */
1824 if (mddev->curr_resync < max_sector) { /* aborted */
1825 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1826 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1827 &sync_blocks, 1);
1828 else for (i=0; i<conf->raid_disks; i++) {
1829 sector_t sect =
1830 raid10_find_virt(conf, mddev->curr_resync, i);
1831 bitmap_end_sync(mddev->bitmap, sect,
1832 &sync_blocks, 1);
1833 }
1834 } else /* completed sync */
1835 conf->fullsync = 0;
1836
1837 bitmap_close_sync(mddev->bitmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 close_sync(conf);
NeilBrown57afd892005-06-21 17:17:13 -07001839 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840 return sectors_skipped;
1841 }
1842 if (chunks_skipped >= conf->raid_disks) {
1843 /* if there has been nothing to do on any drive,
1844 * then there is nothing to do at all..
1845 */
NeilBrown57afd892005-06-21 17:17:13 -07001846 *skipped = 1;
1847 return (max_sector - sector_nr) + sectors_skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848 }
1849
NeilBrownc6207272008-02-06 01:39:52 -08001850 if (max_sector > mddev->resync_max)
1851 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1852
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853 /* make sure whole request will fit in a chunk - if chunks
1854 * are meaningful
1855 */
1856 if (conf->near_copies < conf->raid_disks &&
1857 max_sector > (sector_nr | conf->chunk_mask))
1858 max_sector = (sector_nr | conf->chunk_mask) + 1;
1859 /*
1860 * If there is non-resync activity waiting for us then
1861 * put in a delay to throttle resync.
1862 */
NeilBrown0a27ec92006-01-06 00:20:13 -08001863 if (!go_faster && conf->nr_waiting)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001864 msleep_interruptible(1000);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001865
1866 /* Again, very different code for resync and recovery.
1867 * Both must result in an r10bio with a list of bios that
1868 * have bi_end_io, bi_sector, bi_bdev set,
1869 * and bi_private set to the r10bio.
1870 * For recovery, we may actually create several r10bios
1871 * with 2 bios in each, that correspond to the bios in the main one.
1872 * In this case, the subordinate r10bios link back through a
1873 * borrowed master_bio pointer, and the counter in the master
1874 * includes a ref from each subordinate.
1875 */
1876 /* First, we decide what to do and set ->bi_end_io
1877 * To end_sync_read if we want to read, and
1878 * end_sync_write if we will want to write.
1879 */
1880
NeilBrown6cce3b232006-01-06 00:20:16 -08001881 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1883 /* recovery... the complicated one */
NeilBrowna9f326e2009-09-23 18:06:41 +10001884 int j, k;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 r10_bio = NULL;
1886
1887 for (i=0 ; i<conf->raid_disks; i++)
1888 if (conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001889 !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) {
NeilBrown6cce3b232006-01-06 00:20:16 -08001890 int still_degraded = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001891 /* want to reconstruct this device */
1892 r10bio_t *rb2 = r10_bio;
NeilBrown6cce3b232006-01-06 00:20:16 -08001893 sector_t sect = raid10_find_virt(conf, sector_nr, i);
1894 int must_sync;
1895 /* Unless we are doing a full sync, we only need
1896 * to recover the block if it is set in the bitmap
1897 */
1898 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1899 &sync_blocks, 1);
1900 if (sync_blocks < max_sync)
1901 max_sync = sync_blocks;
1902 if (!must_sync &&
1903 !conf->fullsync) {
1904 /* yep, skip the sync_blocks here, but don't assume
1905 * that there will never be anything to do here
1906 */
1907 chunks_skipped = -1;
1908 continue;
1909 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910
1911 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
NeilBrown6cce3b232006-01-06 00:20:16 -08001912 raise_barrier(conf, rb2 != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 atomic_set(&r10_bio->remaining, 0);
1914
1915 r10_bio->master_bio = (struct bio*)rb2;
1916 if (rb2)
1917 atomic_inc(&rb2->remaining);
1918 r10_bio->mddev = mddev;
1919 set_bit(R10BIO_IsRecover, &r10_bio->state);
NeilBrown6cce3b232006-01-06 00:20:16 -08001920 r10_bio->sector = sect;
1921
Linus Torvalds1da177e2005-04-16 15:20:36 -07001922 raid10_find_phys(conf, r10_bio);
NeilBrown18055562009-05-07 12:48:10 +10001923
1924 /* Need to check if the array will still be
NeilBrown6cce3b232006-01-06 00:20:16 -08001925 * degraded
1926 */
NeilBrown18055562009-05-07 12:48:10 +10001927 for (j=0; j<conf->raid_disks; j++)
1928 if (conf->mirrors[j].rdev == NULL ||
1929 test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
NeilBrown6cce3b232006-01-06 00:20:16 -08001930 still_degraded = 1;
NeilBrowna24a8dd2006-01-06 00:20:35 -08001931 break;
1932 }
NeilBrown18055562009-05-07 12:48:10 +10001933
NeilBrown6cce3b232006-01-06 00:20:16 -08001934 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1935 &sync_blocks, still_degraded);
1936
Linus Torvalds1da177e2005-04-16 15:20:36 -07001937 for (j=0; j<conf->copies;j++) {
1938 int d = r10_bio->devs[j].devnum;
1939 if (conf->mirrors[d].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001940 test_bit(In_sync, &conf->mirrors[d].rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001941 /* This is where we read from */
1942 bio = r10_bio->devs[0].bio;
1943 bio->bi_next = biolist;
1944 biolist = bio;
1945 bio->bi_private = r10_bio;
1946 bio->bi_end_io = end_sync_read;
NeilBrown802ba062006-12-13 00:34:13 -08001947 bio->bi_rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001948 bio->bi_sector = r10_bio->devs[j].addr +
1949 conf->mirrors[d].rdev->data_offset;
1950 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
1951 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1952 atomic_inc(&r10_bio->remaining);
1953 /* and we write to 'i' */
1954
1955 for (k=0; k<conf->copies; k++)
1956 if (r10_bio->devs[k].devnum == i)
1957 break;
NeilBrown64a742b2007-02-28 20:11:18 -08001958 BUG_ON(k == conf->copies);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 bio = r10_bio->devs[1].bio;
1960 bio->bi_next = biolist;
1961 biolist = bio;
1962 bio->bi_private = r10_bio;
1963 bio->bi_end_io = end_sync_write;
NeilBrown802ba062006-12-13 00:34:13 -08001964 bio->bi_rw = WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 bio->bi_sector = r10_bio->devs[k].addr +
1966 conf->mirrors[i].rdev->data_offset;
1967 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1968
1969 r10_bio->devs[0].devnum = d;
1970 r10_bio->devs[1].devnum = i;
1971
1972 break;
1973 }
1974 }
1975 if (j == conf->copies) {
NeilBrown87fc7672005-09-09 16:24:04 -07001976 /* Cannot recover, so abort the recovery */
1977 put_buf(r10_bio);
K.Tanakaa07e6ab2008-03-04 14:29:37 -08001978 if (rb2)
1979 atomic_dec(&rb2->remaining);
NeilBrown87fc7672005-09-09 16:24:04 -07001980 r10_bio = rb2;
NeilBrowndfc70642008-05-23 13:04:39 -07001981 if (!test_and_set_bit(MD_RECOVERY_INTR,
1982 &mddev->recovery))
NeilBrown128595e2010-05-03 14:47:14 +10001983 printk(KERN_INFO "md/raid10:%s: insufficient "
1984 "working devices for recovery.\n",
NeilBrown87fc7672005-09-09 16:24:04 -07001985 mdname(mddev));
1986 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 }
1988 }
1989 if (biolist == NULL) {
1990 while (r10_bio) {
1991 r10bio_t *rb2 = r10_bio;
1992 r10_bio = (r10bio_t*) rb2->master_bio;
1993 rb2->master_bio = NULL;
1994 put_buf(rb2);
1995 }
1996 goto giveup;
1997 }
1998 } else {
1999 /* resync. Schedule a read for every block at this virt offset */
2000 int count = 0;
NeilBrown6cce3b232006-01-06 00:20:16 -08002001
NeilBrown78200d42009-02-25 13:18:47 +11002002 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2003
NeilBrown6cce3b232006-01-06 00:20:16 -08002004 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2005 &sync_blocks, mddev->degraded) &&
2006 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2007 /* We can skip this block */
2008 *skipped = 1;
2009 return sync_blocks + sectors_skipped;
2010 }
2011 if (sync_blocks < max_sync)
2012 max_sync = sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002013 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
2014
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015 r10_bio->mddev = mddev;
2016 atomic_set(&r10_bio->remaining, 0);
NeilBrown6cce3b232006-01-06 00:20:16 -08002017 raise_barrier(conf, 0);
2018 conf->next_resync = sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019
2020 r10_bio->master_bio = NULL;
2021 r10_bio->sector = sector_nr;
2022 set_bit(R10BIO_IsSync, &r10_bio->state);
2023 raid10_find_phys(conf, r10_bio);
2024 r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
2025
2026 for (i=0; i<conf->copies; i++) {
2027 int d = r10_bio->devs[i].devnum;
2028 bio = r10_bio->devs[i].bio;
2029 bio->bi_end_io = NULL;
NeilBrownaf03b8e2007-06-16 10:16:06 -07002030 clear_bit(BIO_UPTODATE, &bio->bi_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031 if (conf->mirrors[d].rdev == NULL ||
NeilBrownb2d444d2005-11-08 21:39:31 -08002032 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033 continue;
2034 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2035 atomic_inc(&r10_bio->remaining);
2036 bio->bi_next = biolist;
2037 biolist = bio;
2038 bio->bi_private = r10_bio;
2039 bio->bi_end_io = end_sync_read;
NeilBrown802ba062006-12-13 00:34:13 -08002040 bio->bi_rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002041 bio->bi_sector = r10_bio->devs[i].addr +
2042 conf->mirrors[d].rdev->data_offset;
2043 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
2044 count++;
2045 }
2046
2047 if (count < 2) {
2048 for (i=0; i<conf->copies; i++) {
2049 int d = r10_bio->devs[i].devnum;
2050 if (r10_bio->devs[i].bio->bi_end_io)
2051 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
2052 }
2053 put_buf(r10_bio);
2054 biolist = NULL;
2055 goto giveup;
2056 }
2057 }
2058
2059 for (bio = biolist; bio ; bio=bio->bi_next) {
2060
2061 bio->bi_flags &= ~(BIO_POOL_MASK - 1);
2062 if (bio->bi_end_io)
2063 bio->bi_flags |= 1 << BIO_UPTODATE;
2064 bio->bi_vcnt = 0;
2065 bio->bi_idx = 0;
2066 bio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002067 bio->bi_size = 0;
2068 }
2069
2070 nr_sectors = 0;
NeilBrown6cce3b232006-01-06 00:20:16 -08002071 if (sector_nr + max_sync < max_sector)
2072 max_sector = sector_nr + max_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 do {
2074 struct page *page;
2075 int len = PAGE_SIZE;
2076 disk = 0;
2077 if (sector_nr + (len>>9) > max_sector)
2078 len = (max_sector - sector_nr) << 9;
2079 if (len == 0)
2080 break;
2081 for (bio= biolist ; bio ; bio=bio->bi_next) {
2082 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2083 if (bio_add_page(bio, page, len, 0) == 0) {
2084 /* stop here */
2085 struct bio *bio2;
2086 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2087 for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) {
2088 /* remove last page from this bio */
2089 bio2->bi_vcnt--;
2090 bio2->bi_size -= len;
2091 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
2092 }
2093 goto bio_full;
2094 }
2095 disk = i;
2096 }
2097 nr_sectors += len>>9;
2098 sector_nr += len>>9;
2099 } while (biolist->bi_vcnt < RESYNC_PAGES);
2100 bio_full:
2101 r10_bio->sectors = nr_sectors;
2102
2103 while (biolist) {
2104 bio = biolist;
2105 biolist = biolist->bi_next;
2106
2107 bio->bi_next = NULL;
2108 r10_bio = bio->bi_private;
2109 r10_bio->sectors = nr_sectors;
2110
2111 if (bio->bi_end_io == end_sync_read) {
2112 md_sync_acct(bio->bi_bdev, nr_sectors);
2113 generic_make_request(bio);
2114 }
2115 }
2116
NeilBrown57afd892005-06-21 17:17:13 -07002117 if (sectors_skipped)
2118 /* pretend they weren't skipped, it makes
2119 * no important difference in this case
2120 */
2121 md_done_sync(mddev, sectors_skipped, 1);
2122
Linus Torvalds1da177e2005-04-16 15:20:36 -07002123 return sectors_skipped + nr_sectors;
2124 giveup:
2125 /* There is nowhere to write, so all non-sync
2126 * drives must be failed, so try the next chunk...
2127 */
NeilBrown09b40682009-02-25 13:18:47 +11002128 if (sector_nr + max_sync < max_sector)
2129 max_sector = sector_nr + max_sync;
2130
2131 sectors_skipped += (max_sector - sector_nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002132 chunks_skipped ++;
2133 sector_nr = max_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002134 goto skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135}
2136
Dan Williams80c3a6c2009-03-17 18:10:40 -07002137static sector_t
2138raid10_size(mddev_t *mddev, sector_t sectors, int raid_disks)
2139{
2140 sector_t size;
NeilBrown070ec552009-06-16 16:54:21 +10002141 conf_t *conf = mddev->private;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002142
2143 if (!raid_disks)
NeilBrown84707f32010-03-16 17:23:35 +11002144 raid_disks = conf->raid_disks;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002145 if (!sectors)
Trela, Maciejdab8b292010-03-08 16:02:45 +11002146 sectors = conf->dev_sectors;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002147
2148 size = sectors >> conf->chunk_shift;
2149 sector_div(size, conf->far_copies);
2150 size = size * raid_disks;
2151 sector_div(size, conf->near_copies);
2152
2153 return size << conf->chunk_shift;
2154}
2155
Trela, Maciejdab8b292010-03-08 16:02:45 +11002156
2157static conf_t *setup_conf(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002158{
Trela, Maciejdab8b292010-03-08 16:02:45 +11002159 conf_t *conf = NULL;
NeilBrownc93983b2006-06-26 00:27:41 -07002160 int nc, fc, fo;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002161 sector_t stride, size;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002162 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163
Andre Noll9d8f0362009-06-18 08:45:01 +10002164 if (mddev->chunk_sectors < (PAGE_SIZE >> 9) ||
2165 !is_power_of_2(mddev->chunk_sectors)) {
NeilBrown128595e2010-05-03 14:47:14 +10002166 printk(KERN_ERR "md/raid10:%s: chunk size must be "
2167 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
2168 mdname(mddev), PAGE_SIZE);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002169 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002170 }
NeilBrown2604b702006-01-06 00:20:36 -08002171
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172 nc = mddev->layout & 255;
2173 fc = (mddev->layout >> 8) & 255;
NeilBrownc93983b2006-06-26 00:27:41 -07002174 fo = mddev->layout & (1<<16);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002175
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176 if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
NeilBrownc93983b2006-06-26 00:27:41 -07002177 (mddev->layout >> 17)) {
NeilBrown128595e2010-05-03 14:47:14 +10002178 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179 mdname(mddev), mddev->layout);
2180 goto out;
2181 }
Trela, Maciejdab8b292010-03-08 16:02:45 +11002182
2183 err = -ENOMEM;
NeilBrown4443ae12006-01-06 00:20:28 -08002184 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002185 if (!conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186 goto out;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002187
NeilBrown4443ae12006-01-06 00:20:28 -08002188 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
Trela, Maciejdab8b292010-03-08 16:02:45 +11002189 GFP_KERNEL);
2190 if (!conf->mirrors)
2191 goto out;
NeilBrown4443ae12006-01-06 00:20:28 -08002192
2193 conf->tmppage = alloc_page(GFP_KERNEL);
2194 if (!conf->tmppage)
Trela, Maciejdab8b292010-03-08 16:02:45 +11002195 goto out;
2196
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197
NeilBrown64a742b2007-02-28 20:11:18 -08002198 conf->raid_disks = mddev->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002199 conf->near_copies = nc;
2200 conf->far_copies = fc;
2201 conf->copies = nc*fc;
NeilBrownc93983b2006-06-26 00:27:41 -07002202 conf->far_offset = fo;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002203 conf->chunk_mask = mddev->new_chunk_sectors - 1;
2204 conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
2205
2206 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
2207 r10bio_pool_free, conf);
2208 if (!conf->r10bio_pool)
2209 goto out;
2210
Andre Noll58c0fed2009-03-31 14:33:13 +11002211 size = mddev->dev_sectors >> conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08002212 sector_div(size, fc);
2213 size = size * conf->raid_disks;
2214 sector_div(size, nc);
2215 /* 'size' is now the number of chunks in the array */
2216 /* calculate "used chunks per device" in 'stride' */
2217 stride = size * conf->copies;
NeilBrownaf03b8e2007-06-16 10:16:06 -07002218
2219 /* We need to round up when dividing by raid_disks to
2220 * get the stride size.
2221 */
2222 stride += conf->raid_disks - 1;
NeilBrown64a742b2007-02-28 20:11:18 -08002223 sector_div(stride, conf->raid_disks);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002224
2225 conf->dev_sectors = stride << conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08002226
NeilBrownc93983b2006-06-26 00:27:41 -07002227 if (fo)
NeilBrown64a742b2007-02-28 20:11:18 -08002228 stride = 1;
2229 else
NeilBrownc93983b2006-06-26 00:27:41 -07002230 sector_div(stride, fc);
NeilBrown64a742b2007-02-28 20:11:18 -08002231 conf->stride = stride << conf->chunk_shift;
2232
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233
Neil Browne7e72bf2008-05-14 16:05:54 -07002234 spin_lock_init(&conf->device_lock);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002235 INIT_LIST_HEAD(&conf->retry_list);
2236
2237 spin_lock_init(&conf->resync_lock);
2238 init_waitqueue_head(&conf->wait_barrier);
2239
2240 conf->thread = md_register_thread(raid10d, mddev, NULL);
2241 if (!conf->thread)
2242 goto out;
2243
2244 conf->scale_disks = 0;
2245 conf->mddev = mddev;
2246 return conf;
2247
2248 out:
NeilBrown128595e2010-05-03 14:47:14 +10002249 printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
Trela, Maciejdab8b292010-03-08 16:02:45 +11002250 mdname(mddev));
2251 if (conf) {
2252 if (conf->r10bio_pool)
2253 mempool_destroy(conf->r10bio_pool);
2254 kfree(conf->mirrors);
2255 safe_put_page(conf->tmppage);
2256 kfree(conf);
2257 }
2258 return ERR_PTR(err);
2259}
2260
2261static int run(mddev_t *mddev)
2262{
2263 conf_t *conf;
2264 int i, disk_idx, chunk_size;
2265 mirror_info_t *disk;
2266 mdk_rdev_t *rdev;
2267 sector_t size;
2268
2269 /*
2270 * copy the already verified devices into our private RAID10
2271 * bookkeeping area. [whatever we allocate in run(),
2272 * should be freed in stop()]
2273 */
2274
2275 if (mddev->private == NULL) {
2276 conf = setup_conf(mddev);
2277 if (IS_ERR(conf))
2278 return PTR_ERR(conf);
2279 mddev->private = conf;
2280 }
2281 conf = mddev->private;
2282 if (!conf)
2283 goto out;
2284
Neil Browne7e72bf2008-05-14 16:05:54 -07002285 mddev->queue->queue_lock = &conf->device_lock;
2286
Trela, Maciejdab8b292010-03-08 16:02:45 +11002287 mddev->thread = conf->thread;
2288 conf->thread = NULL;
2289
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10002290 chunk_size = mddev->chunk_sectors << 9;
2291 blk_queue_io_min(mddev->queue, chunk_size);
2292 if (conf->raid_disks % conf->near_copies)
2293 blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
2294 else
2295 blk_queue_io_opt(mddev->queue, chunk_size *
2296 (conf->raid_disks / conf->near_copies));
2297
Cheng Renquan159ec1f2009-01-09 08:31:08 +11002298 list_for_each_entry(rdev, &mddev->disks, same_set) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002299 disk_idx = rdev->raid_disk;
NeilBrown84707f32010-03-16 17:23:35 +11002300 if (disk_idx >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07002301 || disk_idx < 0)
2302 continue;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002303 if (conf->scale_disks) {
2304 disk_idx *= conf->scale_disks;
2305 rdev->raid_disk = disk_idx;
2306 /* MOVE 'rd%d' link !! */
2307 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308 disk = conf->mirrors + disk_idx;
2309
2310 disk->rdev = rdev;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10002311 disk_stack_limits(mddev->gendisk, rdev->bdev,
2312 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002313 /* as we don't honour merge_bvec_fn, we must never risk
NeilBrown627a2d32010-03-08 16:44:38 +11002314 * violating it, so limit max_segments to 1 lying
2315 * within a single page.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316 */
NeilBrown627a2d32010-03-08 16:44:38 +11002317 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2318 blk_queue_max_segments(mddev->queue, 1);
2319 blk_queue_segment_boundary(mddev->queue,
2320 PAGE_CACHE_SIZE - 1);
2321 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002322
2323 disk->head_position = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002324 }
NeilBrown6d508242005-09-09 16:24:03 -07002325 /* need to check that every block has at least one working mirror */
2326 if (!enough(conf)) {
NeilBrown128595e2010-05-03 14:47:14 +10002327 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
NeilBrown6d508242005-09-09 16:24:03 -07002328 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002329 goto out_free_conf;
2330 }
2331
2332 mddev->degraded = 0;
2333 for (i = 0; i < conf->raid_disks; i++) {
2334
2335 disk = conf->mirrors + i;
2336
NeilBrown5fd6c1d2006-06-26 00:27:40 -07002337 if (!disk->rdev ||
NeilBrown2e333e82006-10-21 10:24:07 -07002338 !test_bit(In_sync, &disk->rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002339 disk->head_position = 0;
2340 mddev->degraded++;
Neil Brown8c2e8702008-06-28 08:30:52 +10002341 if (disk->rdev)
2342 conf->fullsync = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002343 }
2344 }
2345
Andre Noll8c6ac862009-06-18 08:48:06 +10002346 if (mddev->recovery_cp != MaxSector)
NeilBrown128595e2010-05-03 14:47:14 +10002347 printk(KERN_NOTICE "md/raid10:%s: not clean"
Andre Noll8c6ac862009-06-18 08:48:06 +10002348 " -- starting background reconstruction\n",
2349 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002350 printk(KERN_INFO
NeilBrown128595e2010-05-03 14:47:14 +10002351 "md/raid10:%s: active with %d out of %d devices\n",
NeilBrown84707f32010-03-16 17:23:35 +11002352 mdname(mddev), conf->raid_disks - mddev->degraded,
2353 conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002354 /*
2355 * Ok, everything is just fine now
2356 */
Trela, Maciejdab8b292010-03-08 16:02:45 +11002357 mddev->dev_sectors = conf->dev_sectors;
2358 size = raid10_size(mddev, 0, 0);
2359 md_set_array_sectors(mddev, size);
2360 mddev->resync_max_sectors = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361
NeilBrown7a5febe2005-05-16 21:53:16 -07002362 mddev->queue->unplug_fn = raid10_unplug;
NeilBrown0d129222006-10-03 01:15:54 -07002363 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
2364 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -07002365
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366 /* Calculate max read-ahead size.
2367 * We need to readahead at least twice a whole stripe....
2368 * maybe...
2369 */
2370 {
Andre Noll9d8f0362009-06-18 08:45:01 +10002371 int stripe = conf->raid_disks *
2372 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002373 stripe /= conf->near_copies;
2374 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
2375 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
2376 }
2377
NeilBrown84707f32010-03-16 17:23:35 +11002378 if (conf->near_copies < conf->raid_disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002379 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
Andre Nollac5e7112009-08-03 10:59:47 +10002380 md_integrity_register(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002381 return 0;
2382
2383out_free_conf:
2384 if (conf->r10bio_pool)
2385 mempool_destroy(conf->r10bio_pool);
NeilBrown1345b1d2006-01-06 00:20:40 -08002386 safe_put_page(conf->tmppage);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002387 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002388 kfree(conf);
2389 mddev->private = NULL;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002390 md_unregister_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002391out:
2392 return -EIO;
2393}
2394
2395static int stop(mddev_t *mddev)
2396{
NeilBrown070ec552009-06-16 16:54:21 +10002397 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002398
NeilBrown409c57f2009-03-31 14:39:39 +11002399 raise_barrier(conf, 0);
2400 lower_barrier(conf);
2401
Linus Torvalds1da177e2005-04-16 15:20:36 -07002402 md_unregister_thread(mddev->thread);
2403 mddev->thread = NULL;
2404 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2405 if (conf->r10bio_pool)
2406 mempool_destroy(conf->r10bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002407 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408 kfree(conf);
2409 mddev->private = NULL;
2410 return 0;
2411}
2412
NeilBrown6cce3b232006-01-06 00:20:16 -08002413static void raid10_quiesce(mddev_t *mddev, int state)
2414{
NeilBrown070ec552009-06-16 16:54:21 +10002415 conf_t *conf = mddev->private;
NeilBrown6cce3b232006-01-06 00:20:16 -08002416
2417 switch(state) {
2418 case 1:
2419 raise_barrier(conf, 0);
2420 break;
2421 case 0:
2422 lower_barrier(conf);
2423 break;
2424 }
NeilBrown6cce3b232006-01-06 00:20:16 -08002425}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002426
Trela, Maciejdab8b292010-03-08 16:02:45 +11002427static void *raid10_takeover_raid0(mddev_t *mddev)
2428{
2429 mdk_rdev_t *rdev;
2430 conf_t *conf;
2431
2432 if (mddev->degraded > 0) {
NeilBrown128595e2010-05-03 14:47:14 +10002433 printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
2434 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11002435 return ERR_PTR(-EINVAL);
2436 }
2437
2438 /* Update slot numbers to obtain
2439 * degraded raid10 with missing mirrors
2440 */
2441 list_for_each_entry(rdev, &mddev->disks, same_set) {
2442 rdev->raid_disk *= 2;
2443 }
2444
2445 /* Set new parameters */
2446 mddev->new_level = 10;
2447 /* new layout: far_copies = 1, near_copies = 2 */
2448 mddev->new_layout = (1<<8) + 2;
2449 mddev->new_chunk_sectors = mddev->chunk_sectors;
2450 mddev->delta_disks = mddev->raid_disks;
2451 mddev->degraded = mddev->raid_disks;
2452 mddev->raid_disks *= 2;
2453 /* make sure it will be not marked as dirty */
2454 mddev->recovery_cp = MaxSector;
2455
2456 conf = setup_conf(mddev);
2457 conf->scale_disks = 2;
2458 return conf;
2459}
2460
2461static void *raid10_takeover(mddev_t *mddev)
2462{
2463 struct raid0_private_data *raid0_priv;
2464
2465 /* raid10 can take over:
2466 * raid0 - providing it has only two drives
2467 */
2468 if (mddev->level == 0) {
2469 /* for raid0 takeover only one zone is supported */
2470 raid0_priv = mddev->private;
2471 if (raid0_priv->nr_strip_zones > 1) {
NeilBrown128595e2010-05-03 14:47:14 +10002472 printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
2473 " with more than one zone.\n",
2474 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11002475 return ERR_PTR(-EINVAL);
2476 }
2477 return raid10_takeover_raid0(mddev);
2478 }
2479 return ERR_PTR(-EINVAL);
2480}
2481
NeilBrown2604b702006-01-06 00:20:36 -08002482static struct mdk_personality raid10_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002483{
2484 .name = "raid10",
NeilBrown2604b702006-01-06 00:20:36 -08002485 .level = 10,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002486 .owner = THIS_MODULE,
2487 .make_request = make_request,
2488 .run = run,
2489 .stop = stop,
2490 .status = status,
2491 .error_handler = error,
2492 .hot_add_disk = raid10_add_disk,
2493 .hot_remove_disk= raid10_remove_disk,
2494 .spare_active = raid10_spare_active,
2495 .sync_request = sync_request,
NeilBrown6cce3b232006-01-06 00:20:16 -08002496 .quiesce = raid10_quiesce,
Dan Williams80c3a6c2009-03-17 18:10:40 -07002497 .size = raid10_size,
Trela, Maciejdab8b292010-03-08 16:02:45 +11002498 .takeover = raid10_takeover,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002499};
2500
2501static int __init raid_init(void)
2502{
NeilBrown2604b702006-01-06 00:20:36 -08002503 return register_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002504}
2505
2506static void raid_exit(void)
2507{
NeilBrown2604b702006-01-06 00:20:36 -08002508 unregister_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002509}
2510
2511module_init(raid_init);
2512module_exit(raid_exit);
2513MODULE_LICENSE("GPL");
NeilBrown0efb9e62009-12-14 12:49:58 +11002514MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002515MODULE_ALIAS("md-personality-9"); /* RAID10 */
NeilBrownd9d166c2006-01-06 00:20:51 -08002516MODULE_ALIAS("md-raid10");
NeilBrown2604b702006-01-06 00:20:36 -08002517MODULE_ALIAS("md-level-10");