blob: e79f1c5bf71b52be6705d4acc144b3a2028a6b8a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * raid10.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 2000-2004 Neil Brown
5 *
6 * RAID-10 support for md.
7 *
8 * Base on code in raid1.c. See raid1.c for futher copyright information.
9 *
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
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
NeilBrown0a27ec92006-01-06 00:20:13 -080060static void allow_barrier(conf_t *conf);
61static void lower_barrier(conf_t *conf);
62
Al Virodd0fc662005-10-07 07:46:04 +010063static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070064{
65 conf_t *conf = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 int size = offsetof(struct r10bio_s, devs[conf->copies]);
67
68 /* allocate a r10bio with room for raid_disks entries in the bios array */
Jens Axboe7eaceac2011-03-10 08:52:07 +010069 return kzalloc(size, gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070}
71
72static void r10bio_pool_free(void *r10_bio, void *data)
73{
74 kfree(r10_bio);
75}
76
NeilBrown0310fa22008-08-05 15:54:14 +100077/* Maximum size of each resync request */
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#define RESYNC_BLOCK_SIZE (64*1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
NeilBrown0310fa22008-08-05 15:54:14 +100080/* amount of memory to reserve for resync requests */
81#define RESYNC_WINDOW (1024*1024)
82/* maximum number of concurrent requests, memory permitting */
83#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85/*
86 * When performing a resync, we need to read and compare, so
87 * we need as many pages are there are copies.
88 * When performing a recovery, we need 2 bios, one for read,
89 * one for write (we recover only one drive per r10buf)
90 *
91 */
Al Virodd0fc662005-10-07 07:46:04 +010092static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
94 conf_t *conf = data;
95 struct page *page;
96 r10bio_t *r10_bio;
97 struct bio *bio;
98 int i, j;
99 int nalloc;
100
101 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
Jens Axboe7eaceac2011-03-10 08:52:07 +0100102 if (!r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
106 nalloc = conf->copies; /* resync */
107 else
108 nalloc = 2; /* recovery */
109
110 /*
111 * Allocate bios.
112 */
113 for (j = nalloc ; j-- ; ) {
NeilBrown67465572010-10-26 17:33:54 +1100114 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 if (!bio)
116 goto out_free_bio;
117 r10_bio->devs[j].bio = bio;
118 }
119 /*
120 * Allocate RESYNC_PAGES data pages and attach them
121 * where needed.
122 */
123 for (j = 0 ; j < nalloc; j++) {
124 bio = r10_bio->devs[j].bio;
125 for (i = 0; i < RESYNC_PAGES; i++) {
126 page = alloc_page(gfp_flags);
127 if (unlikely(!page))
128 goto out_free_pages;
129
130 bio->bi_io_vec[i].bv_page = page;
131 }
132 }
133
134 return r10_bio;
135
136out_free_pages:
137 for ( ; i > 0 ; i--)
NeilBrown1345b1d2006-01-06 00:20:40 -0800138 safe_put_page(bio->bi_io_vec[i-1].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 while (j--)
140 for (i = 0; i < RESYNC_PAGES ; i++)
NeilBrown1345b1d2006-01-06 00:20:40 -0800141 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 j = -1;
143out_free_bio:
144 while ( ++j < nalloc )
145 bio_put(r10_bio->devs[j].bio);
146 r10bio_pool_free(r10_bio, conf);
147 return NULL;
148}
149
150static void r10buf_pool_free(void *__r10_bio, void *data)
151{
152 int i;
153 conf_t *conf = data;
154 r10bio_t *r10bio = __r10_bio;
155 int j;
156
157 for (j=0; j < conf->copies; j++) {
158 struct bio *bio = r10bio->devs[j].bio;
159 if (bio) {
160 for (i = 0; i < RESYNC_PAGES; i++) {
NeilBrown1345b1d2006-01-06 00:20:40 -0800161 safe_put_page(bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 bio->bi_io_vec[i].bv_page = NULL;
163 }
164 bio_put(bio);
165 }
166 }
167 r10bio_pool_free(r10bio, conf);
168}
169
170static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
171{
172 int i;
173
174 for (i = 0; i < conf->copies; i++) {
175 struct bio **bio = & r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -0800176 if (*bio && *bio != IO_BLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 bio_put(*bio);
178 *bio = NULL;
179 }
180}
181
Arjan van de Ven858119e2006-01-14 13:20:43 -0800182static void free_r10bio(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
NeilBrown070ec552009-06-16 16:54:21 +1000184 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186 /*
187 * Wake up any possible resync thread that waits for the device
188 * to go idle.
189 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800190 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 put_all_bios(conf, r10_bio);
193 mempool_free(r10_bio, conf->r10bio_pool);
194}
195
Arjan van de Ven858119e2006-01-14 13:20:43 -0800196static void put_buf(r10bio_t *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197{
NeilBrown070ec552009-06-16 16:54:21 +1000198 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200 mempool_free(r10_bio, conf->r10buf_pool);
201
NeilBrown0a27ec92006-01-06 00:20:13 -0800202 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
205static void reschedule_retry(r10bio_t *r10_bio)
206{
207 unsigned long flags;
208 mddev_t *mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +1000209 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 spin_lock_irqsave(&conf->device_lock, flags);
212 list_add(&r10_bio->retry_list, &conf->retry_list);
NeilBrown4443ae12006-01-06 00:20:28 -0800213 conf->nr_queued ++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 spin_unlock_irqrestore(&conf->device_lock, flags);
215
Arthur Jones388667b2008-07-25 12:03:38 -0700216 /* wake up frozen array... */
217 wake_up(&conf->wait_barrier);
218
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 md_wakeup_thread(mddev->thread);
220}
221
222/*
223 * raid_end_bio_io() is called when we have finished servicing a mirrored
224 * operation and are ready to return a success/failure code to the buffer
225 * cache layer.
226 */
227static void raid_end_bio_io(r10bio_t *r10_bio)
228{
229 struct bio *bio = r10_bio->master_bio;
230
NeilBrown6712ecf2007-09-27 12:47:43 +0200231 bio_endio(bio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO);
233 free_r10bio(r10_bio);
234}
235
236/*
237 * Update disk head position estimator based on IRQ completion info.
238 */
239static inline void update_head_pos(int slot, r10bio_t *r10_bio)
240{
NeilBrown070ec552009-06-16 16:54:21 +1000241 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
244 r10_bio->devs[slot].addr + (r10_bio->sectors);
245}
246
NeilBrown6712ecf2007-09-27 12:47:43 +0200247static void raid10_end_read_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248{
249 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +1100250 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 int slot, dev;
NeilBrown070ec552009-06-16 16:54:21 +1000252 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255 slot = r10_bio->read_slot;
256 dev = r10_bio->devs[slot].devnum;
257 /*
258 * this branch is our 'one mirror IO has finished' event handler:
259 */
NeilBrown4443ae12006-01-06 00:20:28 -0800260 update_head_pos(slot, r10_bio);
261
262 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 /*
264 * Set R10BIO_Uptodate in our master bio, so that
265 * we will return a good error code to the higher
266 * levels even if IO on some other mirrored buffer fails.
267 *
268 * The 'master' represents the composite IO operation to
269 * user-side. So if something waits for IO, then it will
270 * wait for the 'master' bio.
271 */
272 set_bit(R10BIO_Uptodate, &r10_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 raid_end_bio_io(r10_bio);
NeilBrown4443ae12006-01-06 00:20:28 -0800274 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 /*
276 * oops, read error:
277 */
278 char b[BDEVNAME_SIZE];
279 if (printk_ratelimit())
NeilBrown128595e2010-05-03 14:47:14 +1000280 printk(KERN_ERR "md/raid10:%s: %s: rescheduling sector %llu\n",
281 mdname(conf->mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector);
283 reschedule_retry(r10_bio);
284 }
285
286 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287}
288
NeilBrown6712ecf2007-09-27 12:47:43 +0200289static void raid10_end_write_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290{
291 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +1100292 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 int slot, dev;
NeilBrown070ec552009-06-16 16:54:21 +1000294 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 for (slot = 0; slot < conf->copies; slot++)
297 if (r10_bio->devs[slot].bio == bio)
298 break;
299 dev = r10_bio->devs[slot].devnum;
300
301 /*
302 * this branch is our 'one mirror IO has finished' event handler:
303 */
NeilBrown6cce3b22006-01-06 00:20:16 -0800304 if (!uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
NeilBrown6cce3b22006-01-06 00:20:16 -0800306 /* an I/O failed, we can't clear the bitmap */
307 set_bit(R10BIO_Degraded, &r10_bio->state);
308 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 /*
310 * Set R10BIO_Uptodate in our master bio, so that
311 * we will return a good error code for to the higher
312 * levels even if IO on some other mirrored buffer fails.
313 *
314 * The 'master' represents the composite IO operation to
315 * user-side. So if something waits for IO, then it will
316 * wait for the 'master' bio.
317 */
318 set_bit(R10BIO_Uptodate, &r10_bio->state);
319
320 update_head_pos(slot, r10_bio);
321
322 /*
323 *
324 * Let's see if all mirrored write operations have finished
325 * already.
326 */
327 if (atomic_dec_and_test(&r10_bio->remaining)) {
NeilBrown6cce3b22006-01-06 00:20:16 -0800328 /* clear the bitmap if all writes complete successfully */
329 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
330 r10_bio->sectors,
331 !test_bit(R10BIO_Degraded, &r10_bio->state),
332 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 md_write_end(r10_bio->mddev);
334 raid_end_bio_io(r10_bio);
335 }
336
337 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338}
339
340
341/*
342 * RAID10 layout manager
343 * Aswell as the chunksize and raid_disks count, there are two
344 * parameters: near_copies and far_copies.
345 * near_copies * far_copies must be <= raid_disks.
346 * Normally one of these will be 1.
347 * If both are 1, we get raid0.
348 * If near_copies == raid_disks, we get raid1.
349 *
350 * Chunks are layed out in raid0 style with near_copies copies of the
351 * first chunk, followed by near_copies copies of the next chunk and
352 * so on.
353 * If far_copies > 1, then after 1/far_copies of the array has been assigned
354 * as described above, we start again with a device offset of near_copies.
355 * So we effectively have another copy of the whole array further down all
356 * the drives, but with blocks on different drives.
357 * With this layout, and block is never stored twice on the one device.
358 *
359 * raid10_find_phys finds the sector offset of a given virtual sector
NeilBrownc93983b2006-06-26 00:27:41 -0700360 * on each device that it is on.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 *
362 * raid10_find_virt does the reverse mapping, from a device and a
363 * sector offset to a virtual address
364 */
365
366static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio)
367{
368 int n,f;
369 sector_t sector;
370 sector_t chunk;
371 sector_t stripe;
372 int dev;
373
374 int slot = 0;
375
376 /* now calculate first sector/dev */
377 chunk = r10bio->sector >> conf->chunk_shift;
378 sector = r10bio->sector & conf->chunk_mask;
379
380 chunk *= conf->near_copies;
381 stripe = chunk;
382 dev = sector_div(stripe, conf->raid_disks);
NeilBrownc93983b2006-06-26 00:27:41 -0700383 if (conf->far_offset)
384 stripe *= conf->far_copies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
386 sector += stripe << conf->chunk_shift;
387
388 /* and calculate all the others */
389 for (n=0; n < conf->near_copies; n++) {
390 int d = dev;
391 sector_t s = sector;
392 r10bio->devs[slot].addr = sector;
393 r10bio->devs[slot].devnum = d;
394 slot++;
395
396 for (f = 1; f < conf->far_copies; f++) {
397 d += conf->near_copies;
398 if (d >= conf->raid_disks)
399 d -= conf->raid_disks;
400 s += conf->stride;
401 r10bio->devs[slot].devnum = d;
402 r10bio->devs[slot].addr = s;
403 slot++;
404 }
405 dev++;
406 if (dev >= conf->raid_disks) {
407 dev = 0;
408 sector += (conf->chunk_mask + 1);
409 }
410 }
411 BUG_ON(slot != conf->copies);
412}
413
414static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev)
415{
416 sector_t offset, chunk, vchunk;
417
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 offset = sector & conf->chunk_mask;
NeilBrownc93983b2006-06-26 00:27:41 -0700419 if (conf->far_offset) {
420 int fc;
421 chunk = sector >> conf->chunk_shift;
422 fc = sector_div(chunk, conf->far_copies);
423 dev -= fc * conf->near_copies;
424 if (dev < 0)
425 dev += conf->raid_disks;
426 } else {
NeilBrown64a742b2007-02-28 20:11:18 -0800427 while (sector >= conf->stride) {
NeilBrownc93983b2006-06-26 00:27:41 -0700428 sector -= conf->stride;
429 if (dev < conf->near_copies)
430 dev += conf->raid_disks - conf->near_copies;
431 else
432 dev -= conf->near_copies;
433 }
434 chunk = sector >> conf->chunk_shift;
435 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 vchunk = chunk * conf->raid_disks + dev;
437 sector_div(vchunk, conf->near_copies);
438 return (vchunk << conf->chunk_shift) + offset;
439}
440
441/**
442 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
443 * @q: request queue
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200444 * @bvm: properties of new bio
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * @biovec: the request that could be merged to it.
446 *
447 * Return amount of bytes we can accept at this offset
448 * If near_copies == raid_disk, there are no striping issues,
449 * but in that case, the function isn't called at all.
450 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200451static int raid10_mergeable_bvec(struct request_queue *q,
452 struct bvec_merge_data *bvm,
453 struct bio_vec *biovec)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454{
455 mddev_t *mddev = q->queuedata;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200456 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 int max;
Andre Noll9d8f0362009-06-18 08:45:01 +1000458 unsigned int chunk_sectors = mddev->chunk_sectors;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200459 unsigned int bio_sectors = bvm->bi_size >> 9;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
461 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
462 if (max < 0) max = 0; /* bio_add cannot handle a negative return */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200463 if (max <= biovec->bv_len && bio_sectors == 0)
464 return biovec->bv_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 else
466 return max;
467}
468
469/*
470 * This routine returns the disk from which the requested read should
471 * be done. There is a per-array 'next expected sequential IO' sector
472 * number - if this matches on the next IO then we use the last disk.
473 * There is also a per-disk 'last know head position' sector that is
474 * maintained from IRQ contexts, both the normal and the resync IO
475 * completion handlers update this position correctly. If there is no
476 * perfect sequential match then we pick the disk whose head is closest.
477 *
478 * If there are 2 mirrors in the same 2 devices, performance degrades
479 * because position is mirror, not device based.
480 *
481 * The rdev for the device selected will have nr_pending incremented.
482 */
483
484/*
485 * FIXME: possibly should rethink readbalancing and do it differently
486 * depending on near_copies / far_copies geometry.
487 */
488static int read_balance(conf_t *conf, r10bio_t *r10_bio)
489{
NeilBrownaf3a2cd2010-05-08 08:20:17 +1000490 const sector_t this_sector = r10_bio->sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 int disk, slot, nslot;
492 const int sectors = r10_bio->sectors;
493 sector_t new_distance, current_distance;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800494 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
496 raid10_find_phys(conf, r10_bio);
497 rcu_read_lock();
498 /*
499 * Check if we can balance. We can balance on the whole
NeilBrown6cce3b22006-01-06 00:20:16 -0800500 * device if no resync is going on (recovery is ok), or below
501 * the resync window. We take the first readable disk when
502 * above the resync window.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 */
504 if (conf->mddev->recovery_cp < MaxSector
505 && (this_sector + sectors >= conf->next_resync)) {
506 /* make sure that disk is operational */
507 slot = 0;
508 disk = r10_bio->devs[slot].devnum;
509
Suzanne Woodd6065f72005-11-08 21:39:27 -0800510 while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800511 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800512 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 slot++;
514 if (slot == conf->copies) {
515 slot = 0;
516 disk = -1;
517 break;
518 }
519 disk = r10_bio->devs[slot].devnum;
520 }
521 goto rb_out;
522 }
523
524
525 /* make sure the disk is operational */
526 slot = 0;
527 disk = r10_bio->devs[slot].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800528 while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800529 r10_bio->devs[slot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800530 !test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 slot ++;
532 if (slot == conf->copies) {
533 disk = -1;
534 goto rb_out;
535 }
536 disk = r10_bio->devs[slot].devnum;
537 }
538
539
NeilBrown3ec67ac2005-09-09 16:23:40 -0700540 current_distance = abs(r10_bio->devs[slot].addr -
541 conf->mirrors[disk].head_position);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800543 /* Find the disk whose head is closest,
544 * or - for far > 1 - find the closest to partition beginning */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
546 for (nslot = slot; nslot < conf->copies; nslot++) {
547 int ndisk = r10_bio->devs[nslot].devnum;
548
549
Suzanne Woodd6065f72005-11-08 21:39:27 -0800550 if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL ||
NeilBrown0eb3ff12006-01-06 00:20:29 -0800551 r10_bio->devs[nslot].bio == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800552 !test_bit(In_sync, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 continue;
554
NeilBrown22dfdf52005-11-28 13:44:09 -0800555 /* This optimisation is debatable, and completely destroys
556 * sequential read speed for 'far copies' arrays. So only
557 * keep it for 'near' arrays, and review those later.
558 */
559 if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 disk = ndisk;
561 slot = nslot;
562 break;
563 }
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800564
565 /* for far > 1 always use the lowest address */
566 if (conf->far_copies > 1)
567 new_distance = r10_bio->devs[nslot].addr;
568 else
569 new_distance = abs(r10_bio->devs[nslot].addr -
570 conf->mirrors[ndisk].head_position);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 if (new_distance < current_distance) {
572 current_distance = new_distance;
573 disk = ndisk;
574 slot = nslot;
575 }
576 }
577
578rb_out:
579 r10_bio->read_slot = slot;
580/* conf->next_seq_sect = this_sector + sectors;*/
581
Suzanne Woodd6065f72005-11-08 21:39:27 -0800582 if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
NeilBrown29fc7e32006-02-03 03:03:41 -0800584 else
585 disk = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 rcu_read_unlock();
587
588 return disk;
589}
590
NeilBrown0d129222006-10-03 01:15:54 -0700591static int raid10_congested(void *data, int bits)
592{
593 mddev_t *mddev = data;
NeilBrown070ec552009-06-16 16:54:21 +1000594 conf_t *conf = mddev->private;
NeilBrown0d129222006-10-03 01:15:54 -0700595 int i, ret = 0;
596
NeilBrown3fa841d2009-09-23 18:10:29 +1000597 if (mddev_congested(mddev, bits))
598 return 1;
NeilBrown0d129222006-10-03 01:15:54 -0700599 rcu_read_lock();
NeilBrown84707f32010-03-16 17:23:35 +1100600 for (i = 0; i < conf->raid_disks && ret == 0; i++) {
NeilBrown0d129222006-10-03 01:15:54 -0700601 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
602 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200603 struct request_queue *q = bdev_get_queue(rdev->bdev);
NeilBrown0d129222006-10-03 01:15:54 -0700604
605 ret |= bdi_congested(&q->backing_dev_info, bits);
606 }
607 }
608 rcu_read_unlock();
609 return ret;
610}
611
Jens Axboe7eaceac2011-03-10 08:52:07 +0100612static void flush_pending_writes(conf_t *conf)
NeilBrowna35e63e2008-03-04 14:29:29 -0800613{
614 /* Any writes that have been queued but are awaiting
615 * bitmap updates get flushed here.
NeilBrowna35e63e2008-03-04 14:29:29 -0800616 */
NeilBrowna35e63e2008-03-04 14:29:29 -0800617 spin_lock_irq(&conf->device_lock);
618
619 if (conf->pending_bio_list.head) {
620 struct bio *bio;
621 bio = bio_list_get(&conf->pending_bio_list);
NeilBrowna35e63e2008-03-04 14:29:29 -0800622 spin_unlock_irq(&conf->device_lock);
623 /* flush any pending bitmap writes to disk
624 * before proceeding w/ I/O */
625 bitmap_unplug(conf->mddev->bitmap);
626
627 while (bio) { /* submit pending writes */
628 struct bio *next = bio->bi_next;
629 bio->bi_next = NULL;
630 generic_make_request(bio);
631 bio = next;
632 }
NeilBrowna35e63e2008-03-04 14:29:29 -0800633 } else
634 spin_unlock_irq(&conf->device_lock);
NeilBrowna35e63e2008-03-04 14:29:29 -0800635}
Jens Axboe7eaceac2011-03-10 08:52:07 +0100636
637static void md_kick_device(mddev_t *mddev)
638{
639 blk_flush_plug(current);
640 md_wakeup_thread(mddev->thread);
641}
642
NeilBrown0a27ec92006-01-06 00:20:13 -0800643/* Barriers....
644 * Sometimes we need to suspend IO while we do something else,
645 * either some resync/recovery, or reconfigure the array.
646 * To do this we raise a 'barrier'.
647 * The 'barrier' is a counter that can be raised multiple times
648 * to count how many activities are happening which preclude
649 * normal IO.
650 * We can only raise the barrier if there is no pending IO.
651 * i.e. if nr_pending == 0.
652 * We choose only to raise the barrier if no-one is waiting for the
653 * barrier to go down. This means that as soon as an IO request
654 * is ready, no other operations which require a barrier will start
655 * until the IO request has had a chance.
656 *
657 * So: regular IO calls 'wait_barrier'. When that returns there
658 * is no backgroup IO happening, It must arrange to call
659 * allow_barrier when it has finished its IO.
660 * backgroup IO calls must call raise_barrier. Once that returns
661 * there is no normal IO happeing. It must arrange to call
662 * lower_barrier when the particular background IO completes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
NeilBrown6cce3b22006-01-06 00:20:16 -0800665static void raise_barrier(conf_t *conf, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666{
NeilBrown6cce3b22006-01-06 00:20:16 -0800667 BUG_ON(force && !conf->barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 spin_lock_irq(&conf->resync_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
NeilBrown6cce3b22006-01-06 00:20:16 -0800670 /* Wait until no block IO is waiting (unless 'force') */
671 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
Jens Axboe7eaceac2011-03-10 08:52:07 +0100672 conf->resync_lock, md_kick_device(conf->mddev));
NeilBrown0a27ec92006-01-06 00:20:13 -0800673
674 /* block any new IO from starting */
675 conf->barrier++;
676
677 /* No wait for all pending IO to complete */
678 wait_event_lock_irq(conf->wait_barrier,
679 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
Jens Axboe7eaceac2011-03-10 08:52:07 +0100680 conf->resync_lock, md_kick_device(conf->mddev));
NeilBrown0a27ec92006-01-06 00:20:13 -0800681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 spin_unlock_irq(&conf->resync_lock);
683}
684
NeilBrown0a27ec92006-01-06 00:20:13 -0800685static void lower_barrier(conf_t *conf)
686{
687 unsigned long flags;
688 spin_lock_irqsave(&conf->resync_lock, flags);
689 conf->barrier--;
690 spin_unlock_irqrestore(&conf->resync_lock, flags);
691 wake_up(&conf->wait_barrier);
692}
693
694static void wait_barrier(conf_t *conf)
695{
696 spin_lock_irq(&conf->resync_lock);
697 if (conf->barrier) {
698 conf->nr_waiting++;
699 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
700 conf->resync_lock,
Jens Axboe7eaceac2011-03-10 08:52:07 +0100701 md_kick_device(conf->mddev));
NeilBrown0a27ec92006-01-06 00:20:13 -0800702 conf->nr_waiting--;
703 }
704 conf->nr_pending++;
705 spin_unlock_irq(&conf->resync_lock);
706}
707
708static void allow_barrier(conf_t *conf)
709{
710 unsigned long flags;
711 spin_lock_irqsave(&conf->resync_lock, flags);
712 conf->nr_pending--;
713 spin_unlock_irqrestore(&conf->resync_lock, flags);
714 wake_up(&conf->wait_barrier);
715}
716
NeilBrown4443ae12006-01-06 00:20:28 -0800717static void freeze_array(conf_t *conf)
718{
719 /* stop syncio and normal IO and wait for everything to
NeilBrownf1885932006-01-06 00:20:42 -0800720 * go quiet.
NeilBrown4443ae12006-01-06 00:20:28 -0800721 * We increment barrier and nr_waiting, and then
NeilBrown1c830532008-03-04 14:29:35 -0800722 * wait until nr_pending match nr_queued+1
723 * This is called in the context of one normal IO request
724 * that has failed. Thus any sync request that might be pending
725 * will be blocked by nr_pending, and we need to wait for
726 * pending IO requests to complete or be queued for re-try.
727 * Thus the number queued (nr_queued) plus this request (1)
728 * must match the number of pending IOs (nr_pending) before
729 * we continue.
NeilBrown4443ae12006-01-06 00:20:28 -0800730 */
731 spin_lock_irq(&conf->resync_lock);
732 conf->barrier++;
733 conf->nr_waiting++;
734 wait_event_lock_irq(conf->wait_barrier,
NeilBrown1c830532008-03-04 14:29:35 -0800735 conf->nr_pending == conf->nr_queued+1,
NeilBrown4443ae12006-01-06 00:20:28 -0800736 conf->resync_lock,
NeilBrowna35e63e2008-03-04 14:29:29 -0800737 ({ flush_pending_writes(conf);
Jens Axboe7eaceac2011-03-10 08:52:07 +0100738 md_kick_device(conf->mddev); }));
NeilBrown4443ae12006-01-06 00:20:28 -0800739 spin_unlock_irq(&conf->resync_lock);
740}
741
742static void unfreeze_array(conf_t *conf)
743{
744 /* reverse the effect of the freeze */
745 spin_lock_irq(&conf->resync_lock);
746 conf->barrier--;
747 conf->nr_waiting--;
748 wake_up(&conf->wait_barrier);
749 spin_unlock_irq(&conf->resync_lock);
750}
751
NeilBrown21a52c62010-04-01 15:02:13 +1100752static int make_request(mddev_t *mddev, struct bio * bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
NeilBrown070ec552009-06-16 16:54:21 +1000754 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 mirror_info_t *mirror;
756 r10bio_t *r10_bio;
757 struct bio *read_bio;
758 int i;
759 int chunk_sects = conf->chunk_mask + 1;
Jens Axboea3623572005-11-01 09:26:16 +0100760 const int rw = bio_data_dir(bio);
NeilBrown2c7d46e2010-08-18 16:16:05 +1000761 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
Tejun Heoe9c74692010-09-03 11:56:18 +0200762 const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
NeilBrown6cce3b22006-01-06 00:20:16 -0800763 unsigned long flags;
Dan Williams6bfe0b42008-04-30 00:52:32 -0700764 mdk_rdev_t *blocked_rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
Tejun Heoe9c74692010-09-03 11:56:18 +0200766 if (unlikely(bio->bi_rw & REQ_FLUSH)) {
767 md_flush_request(mddev, bio);
NeilBrowne5dcdd82005-09-09 16:23:41 -0700768 return 0;
769 }
770
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 /* If this request crosses a chunk boundary, we need to
772 * split it. This will only happen for 1 PAGE (or less) requests.
773 */
774 if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
775 > chunk_sects &&
776 conf->near_copies < conf->raid_disks)) {
777 struct bio_pair *bp;
778 /* Sanity check -- queue functions should prevent this happening */
779 if (bio->bi_vcnt != 1 ||
780 bio->bi_idx != 0)
781 goto bad_map;
782 /* This is a one page bio that upper layers
783 * refuse to split for us, so we need to split it.
784 */
Denis ChengRq6feef532008-10-09 08:57:05 +0200785 bp = bio_split(bio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
NeilBrown51e9ac72010-08-07 21:17:00 +1000787
788 /* Each of these 'make_request' calls will call 'wait_barrier'.
789 * If the first succeeds but the second blocks due to the resync
790 * thread raising the barrier, we will deadlock because the
791 * IO to the underlying device will be queued in generic_make_request
792 * and will never complete, so will never reduce nr_pending.
793 * So increment nr_waiting here so no new raise_barriers will
794 * succeed, and so the second wait_barrier cannot block.
795 */
796 spin_lock_irq(&conf->resync_lock);
797 conf->nr_waiting++;
798 spin_unlock_irq(&conf->resync_lock);
799
NeilBrown21a52c62010-04-01 15:02:13 +1100800 if (make_request(mddev, &bp->bio1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 generic_make_request(&bp->bio1);
NeilBrown21a52c62010-04-01 15:02:13 +1100802 if (make_request(mddev, &bp->bio2))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 generic_make_request(&bp->bio2);
804
NeilBrown51e9ac72010-08-07 21:17:00 +1000805 spin_lock_irq(&conf->resync_lock);
806 conf->nr_waiting--;
807 wake_up(&conf->wait_barrier);
808 spin_unlock_irq(&conf->resync_lock);
809
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 bio_pair_release(bp);
811 return 0;
812 bad_map:
NeilBrown128595e2010-05-03 14:47:14 +1000813 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
814 " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
816
NeilBrown6712ecf2007-09-27 12:47:43 +0200817 bio_io_error(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 return 0;
819 }
820
NeilBrown3d310eb2005-06-21 17:17:26 -0700821 md_write_start(mddev, bio);
NeilBrown06d91a52005-06-21 17:17:12 -0700822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 /*
824 * Register the new request and wait if the reconstruction
825 * thread has put up a bar for new requests.
826 * Continue immediately if no resync is active currently.
827 */
NeilBrown0a27ec92006-01-06 00:20:13 -0800828 wait_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
831
832 r10_bio->master_bio = bio;
833 r10_bio->sectors = bio->bi_size >> 9;
834
835 r10_bio->mddev = mddev;
836 r10_bio->sector = bio->bi_sector;
NeilBrown6cce3b22006-01-06 00:20:16 -0800837 r10_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838
Jens Axboea3623572005-11-01 09:26:16 +0100839 if (rw == READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 /*
841 * read balancing logic:
842 */
843 int disk = read_balance(conf, r10_bio);
844 int slot = r10_bio->read_slot;
845 if (disk < 0) {
846 raid_end_bio_io(r10_bio);
847 return 0;
848 }
849 mirror = conf->mirrors + disk;
850
NeilBrowna167f662010-10-26 18:31:13 +1100851 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
853 r10_bio->devs[slot].bio = read_bio;
854
855 read_bio->bi_sector = r10_bio->devs[slot].addr +
856 mirror->rdev->data_offset;
857 read_bio->bi_bdev = mirror->rdev->bdev;
858 read_bio->bi_end_io = raid10_end_read_request;
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200859 read_bio->bi_rw = READ | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 read_bio->bi_private = r10_bio;
861
862 generic_make_request(read_bio);
863 return 0;
864 }
865
866 /*
867 * WRITE:
868 */
Dan Williams6bfe0b42008-04-30 00:52:32 -0700869 /* first select target devices under rcu_lock and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 * inc refcount on their rdev. Record them by setting
871 * bios[x] to bio
872 */
873 raid10_find_phys(conf, r10_bio);
Dan Williams6bfe0b42008-04-30 00:52:32 -0700874 retry_write:
Harvey Harrisoncb6969e2008-05-06 20:42:32 -0700875 blocked_rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 rcu_read_lock();
877 for (i = 0; i < conf->copies; i++) {
878 int d = r10_bio->devs[i].devnum;
Suzanne Woodd6065f72005-11-08 21:39:27 -0800879 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
Dan Williams6bfe0b42008-04-30 00:52:32 -0700880 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
881 atomic_inc(&rdev->nr_pending);
882 blocked_rdev = rdev;
883 break;
884 }
885 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800886 atomic_inc(&rdev->nr_pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 r10_bio->devs[i].bio = bio;
NeilBrown6cce3b22006-01-06 00:20:16 -0800888 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 r10_bio->devs[i].bio = NULL;
NeilBrown6cce3b22006-01-06 00:20:16 -0800890 set_bit(R10BIO_Degraded, &r10_bio->state);
891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 }
893 rcu_read_unlock();
894
Dan Williams6bfe0b42008-04-30 00:52:32 -0700895 if (unlikely(blocked_rdev)) {
896 /* Have to wait for this device to get unblocked, then retry */
897 int j;
898 int d;
899
900 for (j = 0; j < i; j++)
901 if (r10_bio->devs[j].bio) {
902 d = r10_bio->devs[j].devnum;
903 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
904 }
905 allow_barrier(conf);
906 md_wait_for_blocked_rdev(blocked_rdev, mddev);
907 wait_barrier(conf);
908 goto retry_write;
909 }
910
NeilBrown4e780642010-10-19 12:54:01 +1100911 atomic_set(&r10_bio->remaining, 1);
912 bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0);
NeilBrown06d91a52005-06-21 17:17:12 -0700913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 for (i = 0; i < conf->copies; i++) {
915 struct bio *mbio;
916 int d = r10_bio->devs[i].devnum;
917 if (!r10_bio->devs[i].bio)
918 continue;
919
NeilBrowna167f662010-10-26 18:31:13 +1100920 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 r10_bio->devs[i].bio = mbio;
922
923 mbio->bi_sector = r10_bio->devs[i].addr+
924 conf->mirrors[d].rdev->data_offset;
925 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
926 mbio->bi_end_io = raid10_end_write_request;
Tejun Heoe9c74692010-09-03 11:56:18 +0200927 mbio->bi_rw = WRITE | do_sync | do_fua;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 mbio->bi_private = r10_bio;
929
930 atomic_inc(&r10_bio->remaining);
NeilBrown4e780642010-10-19 12:54:01 +1100931 spin_lock_irqsave(&conf->device_lock, flags);
932 bio_list_add(&conf->pending_bio_list, mbio);
NeilBrown4e780642010-10-19 12:54:01 +1100933 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 }
935
NeilBrown4e780642010-10-19 12:54:01 +1100936 if (atomic_dec_and_test(&r10_bio->remaining)) {
937 /* This matches the end of raid10_end_write_request() */
938 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
939 r10_bio->sectors,
940 !test_bit(R10BIO_Degraded, &r10_bio->state),
941 0);
Arne Redlichf6f953a2007-07-31 00:37:57 -0700942 md_write_end(mddev);
943 raid_end_bio_io(r10_bio);
Arne Redlichf6f953a2007-07-31 00:37:57 -0700944 }
945
NeilBrowna35e63e2008-03-04 14:29:29 -0800946 /* In case raid10d snuck in to freeze_array */
947 wake_up(&conf->wait_barrier);
948
Jens Axboe7eaceac2011-03-10 08:52:07 +0100949 if (do_sync || !mddev->bitmap)
Lars Ellenberge3881a62007-01-10 23:15:37 -0800950 md_wakeup_thread(mddev->thread);
951
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 return 0;
953}
954
955static void status(struct seq_file *seq, mddev_t *mddev)
956{
NeilBrown070ec552009-06-16 16:54:21 +1000957 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 int i;
959
960 if (conf->near_copies < conf->raid_disks)
Andre Noll9d8f0362009-06-18 08:45:01 +1000961 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 if (conf->near_copies > 1)
963 seq_printf(seq, " %d near-copies", conf->near_copies);
NeilBrownc93983b2006-06-26 00:27:41 -0700964 if (conf->far_copies > 1) {
965 if (conf->far_offset)
966 seq_printf(seq, " %d offset-copies", conf->far_copies);
967 else
968 seq_printf(seq, " %d far-copies", conf->far_copies);
969 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
NeilBrown76186dd2006-10-03 01:15:48 -0700971 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 for (i = 0; i < conf->raid_disks; i++)
973 seq_printf(seq, "%s",
974 conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800975 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 seq_printf(seq, "]");
977}
978
979static void error(mddev_t *mddev, mdk_rdev_t *rdev)
980{
981 char b[BDEVNAME_SIZE];
NeilBrown070ec552009-06-16 16:54:21 +1000982 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983
984 /*
985 * If it is not operational, then we have already marked it as dead
986 * else if it is the last working disks, ignore the error, let the
987 * next level up know.
988 * else mark the drive as failed
989 */
NeilBrownb2d444d2005-11-08 21:39:31 -0800990 if (test_bit(In_sync, &rdev->flags)
NeilBrown76186dd2006-10-03 01:15:48 -0700991 && conf->raid_disks-mddev->degraded == 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 /*
993 * Don't fail the drive, just return an IO error.
994 * The test should really be more sophisticated than
995 * "working_disks == 1", but it isn't critical, and
996 * can wait until we do more sophisticated "is the drive
997 * really dead" tests...
998 */
999 return;
NeilBrownc04be0a2006-10-03 01:15:53 -07001000 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1001 unsigned long flags;
1002 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001004 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 /*
1006 * if recovery is running, make sure it aborts.
1007 */
NeilBrowndfc70642008-05-23 13:04:39 -07001008 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001010 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -07001011 set_bit(MD_CHANGE_DEVS, &mddev->flags);
Joe Perches067032b2011-01-14 09:14:33 +11001012 printk(KERN_ALERT
1013 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1014 "md/raid10:%s: Operation continuing on %d devices.\n",
NeilBrown128595e2010-05-03 14:47:14 +10001015 mdname(mddev), bdevname(rdev->bdev, b),
1016 mdname(mddev), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017}
1018
1019static void print_conf(conf_t *conf)
1020{
1021 int i;
1022 mirror_info_t *tmp;
1023
NeilBrown128595e2010-05-03 14:47:14 +10001024 printk(KERN_DEBUG "RAID10 conf printout:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 if (!conf) {
NeilBrown128595e2010-05-03 14:47:14 +10001026 printk(KERN_DEBUG "(!conf)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 return;
1028 }
NeilBrown128595e2010-05-03 14:47:14 +10001029 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 conf->raid_disks);
1031
1032 for (i = 0; i < conf->raid_disks; i++) {
1033 char b[BDEVNAME_SIZE];
1034 tmp = conf->mirrors + i;
1035 if (tmp->rdev)
NeilBrown128595e2010-05-03 14:47:14 +10001036 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08001037 i, !test_bit(In_sync, &tmp->rdev->flags),
1038 !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 bdevname(tmp->rdev->bdev,b));
1040 }
1041}
1042
1043static void close_sync(conf_t *conf)
1044{
NeilBrown0a27ec92006-01-06 00:20:13 -08001045 wait_barrier(conf);
1046 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047
1048 mempool_destroy(conf->r10buf_pool);
1049 conf->r10buf_pool = NULL;
1050}
1051
NeilBrown6d508242005-09-09 16:24:03 -07001052/* check if there are enough drives for
1053 * every block to appear on atleast one
1054 */
1055static int enough(conf_t *conf)
1056{
1057 int first = 0;
1058
1059 do {
1060 int n = conf->copies;
1061 int cnt = 0;
1062 while (n--) {
1063 if (conf->mirrors[first].rdev)
1064 cnt++;
1065 first = (first+1) % conf->raid_disks;
1066 }
1067 if (cnt == 0)
1068 return 0;
1069 } while (first != 0);
1070 return 1;
1071}
1072
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073static int raid10_spare_active(mddev_t *mddev)
1074{
1075 int i;
1076 conf_t *conf = mddev->private;
1077 mirror_info_t *tmp;
NeilBrown6b965622010-08-18 11:56:59 +10001078 int count = 0;
1079 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
1081 /*
1082 * Find all non-in_sync disks within the RAID10 configuration
1083 * and mark them in_sync
1084 */
1085 for (i = 0; i < conf->raid_disks; i++) {
1086 tmp = conf->mirrors + i;
1087 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08001088 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07001089 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
NeilBrown6b965622010-08-18 11:56:59 +10001090 count++;
Adrian Drzewieckie6ffbcb2010-08-18 11:49:02 +10001091 sysfs_notify_dirent(tmp->rdev->sysfs_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 }
1093 }
NeilBrown6b965622010-08-18 11:56:59 +10001094 spin_lock_irqsave(&conf->device_lock, flags);
1095 mddev->degraded -= count;
1096 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097
1098 print_conf(conf);
NeilBrown6b965622010-08-18 11:56:59 +10001099 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100}
1101
1102
1103static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1104{
1105 conf_t *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10001106 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 int mirror;
1108 mirror_info_t *p;
Neil Brown6c2fce22008-06-28 08:31:31 +10001109 int first = 0;
NeilBrown84707f32010-03-16 17:23:35 +11001110 int last = conf->raid_disks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
1112 if (mddev->recovery_cp < MaxSector)
1113 /* only hot-add to in-sync arrays, as recovery is
1114 * very different from resync
1115 */
Neil Brown199050e2008-06-28 08:31:33 +10001116 return -EBUSY;
NeilBrown6d508242005-09-09 16:24:03 -07001117 if (!enough(conf))
Neil Brown199050e2008-06-28 08:31:33 +10001118 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119
NeilBrowna53a6c82008-11-06 17:28:20 +11001120 if (rdev->raid_disk >= 0)
Neil Brown6c2fce22008-06-28 08:31:31 +10001121 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122
NeilBrown6cce3b22006-01-06 00:20:16 -08001123 if (rdev->saved_raid_disk >= 0 &&
Neil Brown6c2fce22008-06-28 08:31:31 +10001124 rdev->saved_raid_disk >= first &&
NeilBrown6cce3b22006-01-06 00:20:16 -08001125 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1126 mirror = rdev->saved_raid_disk;
1127 else
Neil Brown6c2fce22008-06-28 08:31:31 +10001128 mirror = first;
1129 for ( ; mirror <= last ; mirror++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 if ( !(p=conf->mirrors+mirror)->rdev) {
1131
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10001132 disk_stack_limits(mddev->gendisk, rdev->bdev,
1133 rdev->data_offset << 9);
NeilBrown627a2d32010-03-08 16:44:38 +11001134 /* as we don't honour merge_bvec_fn, we must
1135 * never risk violating it, so limit
1136 * ->max_segments to one lying with a single
1137 * page, as a one page request is never in
1138 * violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 */
NeilBrown627a2d32010-03-08 16:44:38 +11001140 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1141 blk_queue_max_segments(mddev->queue, 1);
1142 blk_queue_segment_boundary(mddev->queue,
1143 PAGE_CACHE_SIZE - 1);
1144 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145
1146 p->head_position = 0;
1147 rdev->raid_disk = mirror;
Neil Brown199050e2008-06-28 08:31:33 +10001148 err = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08001149 if (rdev->saved_raid_disk != mirror)
1150 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08001151 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 break;
1153 }
1154
Andre Nollac5e7112009-08-03 10:59:47 +10001155 md_integrity_add_rdev(rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 print_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10001157 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158}
1159
1160static int raid10_remove_disk(mddev_t *mddev, int number)
1161{
1162 conf_t *conf = mddev->private;
1163 int err = 0;
1164 mdk_rdev_t *rdev;
1165 mirror_info_t *p = conf->mirrors+ number;
1166
1167 print_conf(conf);
1168 rdev = p->rdev;
1169 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08001170 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171 atomic_read(&rdev->nr_pending)) {
1172 err = -EBUSY;
1173 goto abort;
1174 }
NeilBrowndfc70642008-05-23 13:04:39 -07001175 /* Only remove faulty devices in recovery
1176 * is not possible.
1177 */
1178 if (!test_bit(Faulty, &rdev->flags) &&
1179 enough(conf)) {
1180 err = -EBUSY;
1181 goto abort;
1182 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07001184 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 if (atomic_read(&rdev->nr_pending)) {
1186 /* lost the race, try later */
1187 err = -EBUSY;
1188 p->rdev = rdev;
Andre Nollac5e7112009-08-03 10:59:47 +10001189 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 }
Andre Nollac5e7112009-08-03 10:59:47 +10001191 md_integrity_register(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 }
1193abort:
1194
1195 print_conf(conf);
1196 return err;
1197}
1198
1199
NeilBrown6712ecf2007-09-27 12:47:43 +02001200static void end_sync_read(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201{
H Hartley Sweeten7b928132010-03-08 16:02:40 +11001202 r10bio_t *r10_bio = bio->bi_private;
NeilBrown070ec552009-06-16 16:54:21 +10001203 conf_t *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 int i,d;
1205
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 for (i=0; i<conf->copies; i++)
1207 if (r10_bio->devs[i].bio == bio)
1208 break;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001209 BUG_ON(i == conf->copies);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 update_head_pos(i, r10_bio);
1211 d = r10_bio->devs[i].devnum;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001212
1213 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1214 set_bit(R10BIO_Uptodate, &r10_bio->state);
NeilBrown4dbcdc72006-01-06 00:20:52 -08001215 else {
1216 atomic_add(r10_bio->sectors,
1217 &conf->mirrors[d].rdev->corrected_errors);
1218 if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
1219 md_error(r10_bio->mddev,
1220 conf->mirrors[d].rdev);
1221 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222
1223 /* for reconstruct, we always reschedule after a read.
1224 * for resync, only after all reads
1225 */
NeilBrown73d5c382009-02-25 13:18:47 +11001226 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1228 atomic_dec_and_test(&r10_bio->remaining)) {
1229 /* we have read all the blocks,
1230 * do the comparison in process context in raid10d
1231 */
1232 reschedule_retry(r10_bio);
1233 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234}
1235
NeilBrown6712ecf2007-09-27 12:47:43 +02001236static void end_sync_write(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237{
1238 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
H Hartley Sweeten7b928132010-03-08 16:02:40 +11001239 r10bio_t *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 mddev_t *mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +10001241 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 int i,d;
1243
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 for (i = 0; i < conf->copies; i++)
1245 if (r10_bio->devs[i].bio == bio)
1246 break;
1247 d = r10_bio->devs[i].devnum;
1248
1249 if (!uptodate)
1250 md_error(mddev, conf->mirrors[d].rdev);
NeilBrowndfc70642008-05-23 13:04:39 -07001251
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 update_head_pos(i, r10_bio);
1253
NeilBrown73d5c382009-02-25 13:18:47 +11001254 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 while (atomic_dec_and_test(&r10_bio->remaining)) {
1256 if (r10_bio->master_bio == NULL) {
1257 /* the primary of several recovery bios */
NeilBrown73d5c382009-02-25 13:18:47 +11001258 sector_t s = r10_bio->sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 put_buf(r10_bio);
NeilBrown73d5c382009-02-25 13:18:47 +11001260 md_done_sync(mddev, s, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261 break;
1262 } else {
1263 r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio;
1264 put_buf(r10_bio);
1265 r10_bio = r10_bio2;
1266 }
1267 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268}
1269
1270/*
1271 * Note: sync and recover and handled very differently for raid10
1272 * This code is for resync.
1273 * For resync, we read through virtual addresses and read all blocks.
1274 * If there is any error, we schedule a write. The lowest numbered
1275 * drive is authoritative.
1276 * However requests come for physical address, so we need to map.
1277 * For every physical address there are raid_disks/copies virtual addresses,
1278 * which is always are least one, but is not necessarly an integer.
1279 * This means that a physical address can span multiple chunks, so we may
1280 * have to submit multiple io requests for a single sync request.
1281 */
1282/*
1283 * We check if all blocks are in-sync and only write to blocks that
1284 * aren't in sync
1285 */
1286static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1287{
NeilBrown070ec552009-06-16 16:54:21 +10001288 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 int i, first;
1290 struct bio *tbio, *fbio;
1291
1292 atomic_set(&r10_bio->remaining, 1);
1293
1294 /* find the first device with a block */
1295 for (i=0; i<conf->copies; i++)
1296 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
1297 break;
1298
1299 if (i == conf->copies)
1300 goto done;
1301
1302 first = i;
1303 fbio = r10_bio->devs[i].bio;
1304
1305 /* now find blocks with errors */
NeilBrown0eb3ff12006-01-06 00:20:29 -08001306 for (i=0 ; i < conf->copies ; i++) {
1307 int j, d;
1308 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310 tbio = r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001311
1312 if (tbio->bi_end_io != end_sync_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 continue;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001314 if (i == first)
1315 continue;
1316 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
1317 /* We know that the bi_io_vec layout is the same for
1318 * both 'first' and 'i', so we just compare them.
1319 * All vec entries are PAGE_SIZE;
1320 */
1321 for (j = 0; j < vcnt; j++)
1322 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
1323 page_address(tbio->bi_io_vec[j].bv_page),
1324 PAGE_SIZE))
1325 break;
1326 if (j == vcnt)
1327 continue;
1328 mddev->resync_mismatches += r10_bio->sectors;
1329 }
NeilBrown18f08812006-01-06 00:20:25 -08001330 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1331 /* Don't fix anything. */
1332 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 /* Ok, we need to write this bio
1334 * First we need to fixup bv_offset, bv_len and
1335 * bi_vecs, as the read request might have corrupted these
1336 */
1337 tbio->bi_vcnt = vcnt;
1338 tbio->bi_size = r10_bio->sectors << 9;
1339 tbio->bi_idx = 0;
1340 tbio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341 tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1342 tbio->bi_flags |= 1 << BIO_UPTODATE;
1343 tbio->bi_next = NULL;
1344 tbio->bi_rw = WRITE;
1345 tbio->bi_private = r10_bio;
1346 tbio->bi_sector = r10_bio->devs[i].addr;
1347
1348 for (j=0; j < vcnt ; j++) {
1349 tbio->bi_io_vec[j].bv_offset = 0;
1350 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
1351
1352 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1353 page_address(fbio->bi_io_vec[j].bv_page),
1354 PAGE_SIZE);
1355 }
1356 tbio->bi_end_io = end_sync_write;
1357
1358 d = r10_bio->devs[i].devnum;
1359 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1360 atomic_inc(&r10_bio->remaining);
1361 md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
1362
1363 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
1364 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1365 generic_make_request(tbio);
1366 }
1367
1368done:
1369 if (atomic_dec_and_test(&r10_bio->remaining)) {
1370 md_done_sync(mddev, r10_bio->sectors, 1);
1371 put_buf(r10_bio);
1372 }
1373}
1374
1375/*
1376 * Now for the recovery code.
1377 * Recovery happens across physical sectors.
1378 * We recover all non-is_sync drives by finding the virtual address of
1379 * each, and then choose a working drive that also has that virt address.
1380 * There is a separate r10_bio for each non-in_sync drive.
1381 * Only the first two slots are in use. The first for reading,
1382 * The second for writing.
1383 *
1384 */
1385
1386static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1387{
NeilBrown070ec552009-06-16 16:54:21 +10001388 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 int i, d;
1390 struct bio *bio, *wbio;
1391
1392
1393 /* move the pages across to the second bio
1394 * and submit the write request
1395 */
1396 bio = r10_bio->devs[0].bio;
1397 wbio = r10_bio->devs[1].bio;
1398 for (i=0; i < wbio->bi_vcnt; i++) {
1399 struct page *p = bio->bi_io_vec[i].bv_page;
1400 bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page;
1401 wbio->bi_io_vec[i].bv_page = p;
1402 }
1403 d = r10_bio->devs[1].devnum;
1404
1405 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1406 md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
NeilBrown0eb3ff12006-01-06 00:20:29 -08001407 if (test_bit(R10BIO_Uptodate, &r10_bio->state))
1408 generic_make_request(wbio);
1409 else
NeilBrown6712ecf2007-09-27 12:47:43 +02001410 bio_endio(wbio, -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411}
1412
1413
1414/*
Robert Becker1e509152009-12-14 12:49:58 +11001415 * Used by fix_read_error() to decay the per rdev read_errors.
1416 * We halve the read error count for every hour that has elapsed
1417 * since the last recorded read error.
1418 *
1419 */
1420static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
1421{
1422 struct timespec cur_time_mon;
1423 unsigned long hours_since_last;
1424 unsigned int read_errors = atomic_read(&rdev->read_errors);
1425
1426 ktime_get_ts(&cur_time_mon);
1427
1428 if (rdev->last_read_error.tv_sec == 0 &&
1429 rdev->last_read_error.tv_nsec == 0) {
1430 /* first time we've seen a read error */
1431 rdev->last_read_error = cur_time_mon;
1432 return;
1433 }
1434
1435 hours_since_last = (cur_time_mon.tv_sec -
1436 rdev->last_read_error.tv_sec) / 3600;
1437
1438 rdev->last_read_error = cur_time_mon;
1439
1440 /*
1441 * if hours_since_last is > the number of bits in read_errors
1442 * just set read errors to 0. We do this to avoid
1443 * overflowing the shift of read_errors by hours_since_last.
1444 */
1445 if (hours_since_last >= 8 * sizeof(read_errors))
1446 atomic_set(&rdev->read_errors, 0);
1447 else
1448 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
1449}
1450
1451/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452 * This is a kernel thread which:
1453 *
1454 * 1. Retries failed read operations on working mirrors.
1455 * 2. Updates the raid superblock when problems encounter.
NeilBrown6814d532006-10-03 01:15:45 -07001456 * 3. Performs writes following reads for array synchronising.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 */
1458
NeilBrown6814d532006-10-03 01:15:45 -07001459static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
1460{
1461 int sect = 0; /* Offset from r10_bio->sector */
1462 int sectors = r10_bio->sectors;
1463 mdk_rdev_t*rdev;
Robert Becker1e509152009-12-14 12:49:58 +11001464 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10001465 int d = r10_bio->devs[r10_bio->read_slot].devnum;
Robert Becker1e509152009-12-14 12:49:58 +11001466
1467 rcu_read_lock();
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10001468 rdev = rcu_dereference(conf->mirrors[d].rdev);
1469 if (rdev) { /* If rdev is not NULL */
Robert Becker1e509152009-12-14 12:49:58 +11001470 char b[BDEVNAME_SIZE];
1471 int cur_read_error_count = 0;
1472
Robert Becker1e509152009-12-14 12:49:58 +11001473 bdevname(rdev->bdev, b);
1474
1475 if (test_bit(Faulty, &rdev->flags)) {
1476 rcu_read_unlock();
1477 /* drive has already been failed, just ignore any
1478 more fix_read_error() attempts */
1479 return;
1480 }
1481
1482 check_decay_read_errors(mddev, rdev);
1483 atomic_inc(&rdev->read_errors);
1484 cur_read_error_count = atomic_read(&rdev->read_errors);
1485 if (cur_read_error_count > max_read_errors) {
1486 rcu_read_unlock();
1487 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001488 "md/raid10:%s: %s: Raid device exceeded "
Robert Becker1e509152009-12-14 12:49:58 +11001489 "read_error threshold "
1490 "[cur %d:max %d]\n",
NeilBrown128595e2010-05-03 14:47:14 +10001491 mdname(mddev),
Robert Becker1e509152009-12-14 12:49:58 +11001492 b, cur_read_error_count, max_read_errors);
1493 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001494 "md/raid10:%s: %s: Failing raid "
1495 "device\n", mdname(mddev), b);
Robert Becker1e509152009-12-14 12:49:58 +11001496 md_error(mddev, conf->mirrors[d].rdev);
1497 return;
1498 }
1499 }
1500 rcu_read_unlock();
1501
NeilBrown6814d532006-10-03 01:15:45 -07001502 while(sectors) {
1503 int s = sectors;
1504 int sl = r10_bio->read_slot;
1505 int success = 0;
1506 int start;
1507
1508 if (s > (PAGE_SIZE>>9))
1509 s = PAGE_SIZE >> 9;
1510
1511 rcu_read_lock();
1512 do {
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10001513 d = r10_bio->devs[sl].devnum;
NeilBrown6814d532006-10-03 01:15:45 -07001514 rdev = rcu_dereference(conf->mirrors[d].rdev);
1515 if (rdev &&
1516 test_bit(In_sync, &rdev->flags)) {
1517 atomic_inc(&rdev->nr_pending);
1518 rcu_read_unlock();
NeilBrown2b193362010-10-27 15:16:40 +11001519 success = sync_page_io(rdev,
NeilBrown6814d532006-10-03 01:15:45 -07001520 r10_bio->devs[sl].addr +
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11001521 sect,
NeilBrown6814d532006-10-03 01:15:45 -07001522 s<<9,
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11001523 conf->tmppage, READ, false);
NeilBrown6814d532006-10-03 01:15:45 -07001524 rdev_dec_pending(rdev, mddev);
1525 rcu_read_lock();
1526 if (success)
1527 break;
1528 }
1529 sl++;
1530 if (sl == conf->copies)
1531 sl = 0;
1532 } while (!success && sl != r10_bio->read_slot);
1533 rcu_read_unlock();
1534
1535 if (!success) {
1536 /* Cannot read from anywhere -- bye bye array */
1537 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
1538 md_error(mddev, conf->mirrors[dn].rdev);
1539 break;
1540 }
1541
1542 start = sl;
1543 /* write it back and re-read */
1544 rcu_read_lock();
1545 while (sl != r10_bio->read_slot) {
Robert Becker67b8dc42009-12-14 12:49:57 +11001546 char b[BDEVNAME_SIZE];
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10001547
NeilBrown6814d532006-10-03 01:15:45 -07001548 if (sl==0)
1549 sl = conf->copies;
1550 sl--;
1551 d = r10_bio->devs[sl].devnum;
1552 rdev = rcu_dereference(conf->mirrors[d].rdev);
1553 if (rdev &&
1554 test_bit(In_sync, &rdev->flags)) {
1555 atomic_inc(&rdev->nr_pending);
1556 rcu_read_unlock();
1557 atomic_add(s, &rdev->corrected_errors);
NeilBrown2b193362010-10-27 15:16:40 +11001558 if (sync_page_io(rdev,
NeilBrown6814d532006-10-03 01:15:45 -07001559 r10_bio->devs[sl].addr +
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11001560 sect,
1561 s<<9, conf->tmppage, WRITE, false)
Robert Becker67b8dc42009-12-14 12:49:57 +11001562 == 0) {
NeilBrown6814d532006-10-03 01:15:45 -07001563 /* Well, this device is dead */
Robert Becker67b8dc42009-12-14 12:49:57 +11001564 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001565 "md/raid10:%s: read correction "
Robert Becker67b8dc42009-12-14 12:49:57 +11001566 "write failed"
1567 " (%d sectors at %llu on %s)\n",
1568 mdname(mddev), s,
1569 (unsigned long long)(sect+
1570 rdev->data_offset),
1571 bdevname(rdev->bdev, b));
NeilBrown128595e2010-05-03 14:47:14 +10001572 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
Robert Becker67b8dc42009-12-14 12:49:57 +11001573 "drive\n",
NeilBrown128595e2010-05-03 14:47:14 +10001574 mdname(mddev),
Robert Becker67b8dc42009-12-14 12:49:57 +11001575 bdevname(rdev->bdev, b));
NeilBrown6814d532006-10-03 01:15:45 -07001576 md_error(mddev, rdev);
Robert Becker67b8dc42009-12-14 12:49:57 +11001577 }
NeilBrown6814d532006-10-03 01:15:45 -07001578 rdev_dec_pending(rdev, mddev);
1579 rcu_read_lock();
1580 }
1581 }
1582 sl = start;
1583 while (sl != r10_bio->read_slot) {
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10001584
NeilBrown6814d532006-10-03 01:15:45 -07001585 if (sl==0)
1586 sl = conf->copies;
1587 sl--;
1588 d = r10_bio->devs[sl].devnum;
1589 rdev = rcu_dereference(conf->mirrors[d].rdev);
1590 if (rdev &&
1591 test_bit(In_sync, &rdev->flags)) {
1592 char b[BDEVNAME_SIZE];
1593 atomic_inc(&rdev->nr_pending);
1594 rcu_read_unlock();
NeilBrown2b193362010-10-27 15:16:40 +11001595 if (sync_page_io(rdev,
NeilBrown6814d532006-10-03 01:15:45 -07001596 r10_bio->devs[sl].addr +
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11001597 sect,
Robert Becker67b8dc42009-12-14 12:49:57 +11001598 s<<9, conf->tmppage,
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11001599 READ, false) == 0) {
NeilBrown6814d532006-10-03 01:15:45 -07001600 /* Well, this device is dead */
Robert Becker67b8dc42009-12-14 12:49:57 +11001601 printk(KERN_NOTICE
NeilBrown128595e2010-05-03 14:47:14 +10001602 "md/raid10:%s: unable to read back "
Robert Becker67b8dc42009-12-14 12:49:57 +11001603 "corrected sectors"
1604 " (%d sectors at %llu on %s)\n",
1605 mdname(mddev), s,
1606 (unsigned long long)(sect+
1607 rdev->data_offset),
1608 bdevname(rdev->bdev, b));
NeilBrown128595e2010-05-03 14:47:14 +10001609 printk(KERN_NOTICE "md/raid10:%s: %s: failing drive\n",
1610 mdname(mddev),
Robert Becker67b8dc42009-12-14 12:49:57 +11001611 bdevname(rdev->bdev, b));
1612
NeilBrown6814d532006-10-03 01:15:45 -07001613 md_error(mddev, rdev);
Robert Becker67b8dc42009-12-14 12:49:57 +11001614 } else {
NeilBrown6814d532006-10-03 01:15:45 -07001615 printk(KERN_INFO
NeilBrown128595e2010-05-03 14:47:14 +10001616 "md/raid10:%s: read error corrected"
NeilBrown6814d532006-10-03 01:15:45 -07001617 " (%d sectors at %llu on %s)\n",
1618 mdname(mddev), s,
Randy Dunlap969b7552006-10-28 10:38:32 -07001619 (unsigned long long)(sect+
1620 rdev->data_offset),
NeilBrown6814d532006-10-03 01:15:45 -07001621 bdevname(rdev->bdev, b));
Robert Becker67b8dc42009-12-14 12:49:57 +11001622 }
NeilBrown6814d532006-10-03 01:15:45 -07001623
1624 rdev_dec_pending(rdev, mddev);
1625 rcu_read_lock();
1626 }
1627 }
1628 rcu_read_unlock();
1629
1630 sectors -= s;
1631 sect += s;
1632 }
1633}
1634
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635static void raid10d(mddev_t *mddev)
1636{
1637 r10bio_t *r10_bio;
1638 struct bio *bio;
1639 unsigned long flags;
NeilBrown070ec552009-06-16 16:54:21 +10001640 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641 struct list_head *head = &conf->retry_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642 mdk_rdev_t *rdev;
1643
1644 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001645
1646 for (;;) {
1647 char b[BDEVNAME_SIZE];
NeilBrowna35e63e2008-03-04 14:29:29 -08001648
Jens Axboe7eaceac2011-03-10 08:52:07 +01001649 flush_pending_writes(conf);
NeilBrowna35e63e2008-03-04 14:29:29 -08001650
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrowna35e63e2008-03-04 14:29:29 -08001652 if (list_empty(head)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001653 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654 break;
NeilBrowna35e63e2008-03-04 14:29:29 -08001655 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001656 r10_bio = list_entry(head->prev, r10bio_t, retry_list);
1657 list_del(head->prev);
NeilBrown4443ae12006-01-06 00:20:28 -08001658 conf->nr_queued--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 spin_unlock_irqrestore(&conf->device_lock, flags);
1660
1661 mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +10001662 conf = mddev->private;
Jens Axboe7eaceac2011-03-10 08:52:07 +01001663 if (test_bit(R10BIO_IsSync, &r10_bio->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 sync_request_write(mddev, r10_bio);
Jens Axboe7eaceac2011-03-10 08:52:07 +01001665 else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 recovery_request_write(mddev, r10_bio);
Jens Axboe7eaceac2011-03-10 08:52:07 +01001667 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668 int mirror;
NeilBrown4443ae12006-01-06 00:20:28 -08001669 /* we got a read error. Maybe the drive is bad. Maybe just
1670 * the block and we can fix it.
1671 * We freeze all other IO, and try reading the block from
1672 * other devices. When we find one, we re-write
1673 * and check it that fixes the read error.
1674 * This is all done synchronously while the array is
1675 * frozen.
1676 */
NeilBrown6814d532006-10-03 01:15:45 -07001677 if (mddev->ro == 0) {
1678 freeze_array(conf);
1679 fix_read_error(conf, mddev, r10_bio);
1680 unfreeze_array(conf);
NeilBrown4443ae12006-01-06 00:20:28 -08001681 }
1682
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 bio = r10_bio->devs[r10_bio->read_slot].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001684 r10_bio->devs[r10_bio->read_slot].bio =
1685 mddev->ro ? IO_BLOCKED : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 mirror = read_balance(conf, r10_bio);
1687 if (mirror == -1) {
NeilBrown128595e2010-05-03 14:47:14 +10001688 printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 " read error for block %llu\n",
NeilBrown128595e2010-05-03 14:47:14 +10001690 mdname(mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 bdevname(bio->bi_bdev,b),
1692 (unsigned long long)r10_bio->sector);
1693 raid_end_bio_io(r10_bio);
Maik Hampel14e71342007-07-31 00:37:57 -07001694 bio_put(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695 } else {
NeilBrown2c7d46e2010-08-18 16:16:05 +10001696 const unsigned long do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
Maik Hampel14e71342007-07-31 00:37:57 -07001697 bio_put(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 rdev = conf->mirrors[mirror].rdev;
1699 if (printk_ratelimit())
NeilBrown128595e2010-05-03 14:47:14 +10001700 printk(KERN_ERR "md/raid10:%s: %s: redirecting sector %llu to"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 " another mirror\n",
NeilBrown128595e2010-05-03 14:47:14 +10001702 mdname(mddev),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 bdevname(rdev->bdev,b),
1704 (unsigned long long)r10_bio->sector);
NeilBrowna167f662010-10-26 18:31:13 +11001705 bio = bio_clone_mddev(r10_bio->master_bio,
1706 GFP_NOIO, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 r10_bio->devs[r10_bio->read_slot].bio = bio;
1708 bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr
1709 + rdev->data_offset;
1710 bio->bi_bdev = rdev->bdev;
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001711 bio->bi_rw = READ | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 bio->bi_private = r10_bio;
1713 bio->bi_end_io = raid10_end_read_request;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 generic_make_request(bio);
1715 }
1716 }
NeilBrown1d9d5242009-10-16 15:55:32 +11001717 cond_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719}
1720
1721
1722static int init_resync(conf_t *conf)
1723{
1724 int buffs;
1725
1726 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
Eric Sesterhennb6385482006-04-02 13:34:29 +02001727 BUG_ON(conf->r10buf_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
1729 if (!conf->r10buf_pool)
1730 return -ENOMEM;
1731 conf->next_resync = 0;
1732 return 0;
1733}
1734
1735/*
1736 * perform a "sync" on one "block"
1737 *
1738 * We need to make sure that no normal I/O request - particularly write
1739 * requests - conflict with active sync requests.
1740 *
1741 * This is achieved by tracking pending requests and a 'barrier' concept
1742 * that can be installed to exclude normal IO requests.
1743 *
1744 * Resync and recovery are handled very differently.
1745 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
1746 *
1747 * For resync, we iterate over virtual addresses, read all copies,
1748 * and update if there are differences. If only one copy is live,
1749 * skip it.
1750 * For recovery, we iterate over physical addresses, read a good
1751 * value for each non-in_sync drive, and over-write.
1752 *
1753 * So, for recovery we may have several outstanding complex requests for a
1754 * given address, one for each out-of-sync device. We model this by allocating
1755 * a number of r10_bio structures, one for each out-of-sync device.
1756 * As we setup these structures, we collect all bio's together into a list
1757 * which we then process collectively to add pages, and then process again
1758 * to pass to generic_make_request.
1759 *
1760 * The r10_bio structures are linked using a borrowed master_bio pointer.
1761 * This link is counted in ->remaining. When the r10_bio that points to NULL
1762 * has its remaining count decremented to 0, the whole complex operation
1763 * is complete.
1764 *
1765 */
1766
NeilBrown57afd892005-06-21 17:17:13 -07001767static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768{
NeilBrown070ec552009-06-16 16:54:21 +10001769 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770 r10bio_t *r10_bio;
1771 struct bio *biolist = NULL, *bio;
1772 sector_t max_sector, nr_sectors;
1773 int disk;
1774 int i;
NeilBrown6cce3b22006-01-06 00:20:16 -08001775 int max_sync;
NeilBrown57dab0b2010-10-19 10:03:39 +11001776 sector_t sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777
1778 sector_t sectors_skipped = 0;
1779 int chunks_skipped = 0;
1780
1781 if (!conf->r10buf_pool)
1782 if (init_resync(conf))
NeilBrown57afd892005-06-21 17:17:13 -07001783 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784
1785 skipped:
Andre Noll58c0fed2009-03-31 14:33:13 +11001786 max_sector = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1788 max_sector = mddev->resync_max_sectors;
1789 if (sector_nr >= max_sector) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001790 /* If we aborted, we need to abort the
1791 * sync on the 'current' bitmap chucks (there can
1792 * be several when recovering multiple devices).
1793 * as we may have started syncing it but not finished.
1794 * We can find the current address in
1795 * mddev->curr_resync, but for recovery,
1796 * we need to convert that to several
1797 * virtual addresses.
1798 */
1799 if (mddev->curr_resync < max_sector) { /* aborted */
1800 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
1801 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1802 &sync_blocks, 1);
1803 else for (i=0; i<conf->raid_disks; i++) {
1804 sector_t sect =
1805 raid10_find_virt(conf, mddev->curr_resync, i);
1806 bitmap_end_sync(mddev->bitmap, sect,
1807 &sync_blocks, 1);
1808 }
1809 } else /* completed sync */
1810 conf->fullsync = 0;
1811
1812 bitmap_close_sync(mddev->bitmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001813 close_sync(conf);
NeilBrown57afd892005-06-21 17:17:13 -07001814 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001815 return sectors_skipped;
1816 }
1817 if (chunks_skipped >= conf->raid_disks) {
1818 /* if there has been nothing to do on any drive,
1819 * then there is nothing to do at all..
1820 */
NeilBrown57afd892005-06-21 17:17:13 -07001821 *skipped = 1;
1822 return (max_sector - sector_nr) + sectors_skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823 }
1824
NeilBrownc6207272008-02-06 01:39:52 -08001825 if (max_sector > mddev->resync_max)
1826 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1827
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 /* make sure whole request will fit in a chunk - if chunks
1829 * are meaningful
1830 */
1831 if (conf->near_copies < conf->raid_disks &&
1832 max_sector > (sector_nr | conf->chunk_mask))
1833 max_sector = (sector_nr | conf->chunk_mask) + 1;
1834 /*
1835 * If there is non-resync activity waiting for us then
1836 * put in a delay to throttle resync.
1837 */
NeilBrown0a27ec92006-01-06 00:20:13 -08001838 if (!go_faster && conf->nr_waiting)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001839 msleep_interruptible(1000);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840
1841 /* Again, very different code for resync and recovery.
1842 * Both must result in an r10bio with a list of bios that
1843 * have bi_end_io, bi_sector, bi_bdev set,
1844 * and bi_private set to the r10bio.
1845 * For recovery, we may actually create several r10bios
1846 * with 2 bios in each, that correspond to the bios in the main one.
1847 * In this case, the subordinate r10bios link back through a
1848 * borrowed master_bio pointer, and the counter in the master
1849 * includes a ref from each subordinate.
1850 */
1851 /* First, we decide what to do and set ->bi_end_io
1852 * To end_sync_read if we want to read, and
1853 * end_sync_write if we will want to write.
1854 */
1855
NeilBrown6cce3b22006-01-06 00:20:16 -08001856 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001857 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1858 /* recovery... the complicated one */
NeilBrowna9f326e2009-09-23 18:06:41 +10001859 int j, k;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860 r10_bio = NULL;
1861
1862 for (i=0 ; i<conf->raid_disks; i++)
1863 if (conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001864 !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001865 int still_degraded = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001866 /* want to reconstruct this device */
1867 r10bio_t *rb2 = r10_bio;
NeilBrown6cce3b22006-01-06 00:20:16 -08001868 sector_t sect = raid10_find_virt(conf, sector_nr, i);
1869 int must_sync;
1870 /* Unless we are doing a full sync, we only need
1871 * to recover the block if it is set in the bitmap
1872 */
1873 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1874 &sync_blocks, 1);
1875 if (sync_blocks < max_sync)
1876 max_sync = sync_blocks;
1877 if (!must_sync &&
1878 !conf->fullsync) {
1879 /* yep, skip the sync_blocks here, but don't assume
1880 * that there will never be anything to do here
1881 */
1882 chunks_skipped = -1;
1883 continue;
1884 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885
1886 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
NeilBrown6cce3b22006-01-06 00:20:16 -08001887 raise_barrier(conf, rb2 != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 atomic_set(&r10_bio->remaining, 0);
1889
1890 r10_bio->master_bio = (struct bio*)rb2;
1891 if (rb2)
1892 atomic_inc(&rb2->remaining);
1893 r10_bio->mddev = mddev;
1894 set_bit(R10BIO_IsRecover, &r10_bio->state);
NeilBrown6cce3b22006-01-06 00:20:16 -08001895 r10_bio->sector = sect;
1896
Linus Torvalds1da177e2005-04-16 15:20:36 -07001897 raid10_find_phys(conf, r10_bio);
NeilBrown18055562009-05-07 12:48:10 +10001898
1899 /* Need to check if the array will still be
NeilBrown6cce3b22006-01-06 00:20:16 -08001900 * degraded
1901 */
NeilBrown18055562009-05-07 12:48:10 +10001902 for (j=0; j<conf->raid_disks; j++)
1903 if (conf->mirrors[j].rdev == NULL ||
1904 test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001905 still_degraded = 1;
NeilBrowna24a8dd2006-01-06 00:20:35 -08001906 break;
1907 }
NeilBrown18055562009-05-07 12:48:10 +10001908
NeilBrown6cce3b22006-01-06 00:20:16 -08001909 must_sync = bitmap_start_sync(mddev->bitmap, sect,
1910 &sync_blocks, still_degraded);
1911
Linus Torvalds1da177e2005-04-16 15:20:36 -07001912 for (j=0; j<conf->copies;j++) {
1913 int d = r10_bio->devs[j].devnum;
1914 if (conf->mirrors[d].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001915 test_bit(In_sync, &conf->mirrors[d].rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001916 /* This is where we read from */
1917 bio = r10_bio->devs[0].bio;
1918 bio->bi_next = biolist;
1919 biolist = bio;
1920 bio->bi_private = r10_bio;
1921 bio->bi_end_io = end_sync_read;
NeilBrown802ba062006-12-13 00:34:13 -08001922 bio->bi_rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923 bio->bi_sector = r10_bio->devs[j].addr +
1924 conf->mirrors[d].rdev->data_offset;
1925 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
1926 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1927 atomic_inc(&r10_bio->remaining);
1928 /* and we write to 'i' */
1929
1930 for (k=0; k<conf->copies; k++)
1931 if (r10_bio->devs[k].devnum == i)
1932 break;
NeilBrown64a742b2007-02-28 20:11:18 -08001933 BUG_ON(k == conf->copies);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934 bio = r10_bio->devs[1].bio;
1935 bio->bi_next = biolist;
1936 biolist = bio;
1937 bio->bi_private = r10_bio;
1938 bio->bi_end_io = end_sync_write;
NeilBrown802ba062006-12-13 00:34:13 -08001939 bio->bi_rw = WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001940 bio->bi_sector = r10_bio->devs[k].addr +
1941 conf->mirrors[i].rdev->data_offset;
1942 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1943
1944 r10_bio->devs[0].devnum = d;
1945 r10_bio->devs[1].devnum = i;
1946
1947 break;
1948 }
1949 }
1950 if (j == conf->copies) {
NeilBrown87fc7672005-09-09 16:24:04 -07001951 /* Cannot recover, so abort the recovery */
1952 put_buf(r10_bio);
K.Tanakaa07e6ab2008-03-04 14:29:37 -08001953 if (rb2)
1954 atomic_dec(&rb2->remaining);
NeilBrown87fc7672005-09-09 16:24:04 -07001955 r10_bio = rb2;
NeilBrowndfc70642008-05-23 13:04:39 -07001956 if (!test_and_set_bit(MD_RECOVERY_INTR,
1957 &mddev->recovery))
NeilBrown128595e2010-05-03 14:47:14 +10001958 printk(KERN_INFO "md/raid10:%s: insufficient "
1959 "working devices for recovery.\n",
NeilBrown87fc7672005-09-09 16:24:04 -07001960 mdname(mddev));
1961 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001962 }
1963 }
1964 if (biolist == NULL) {
1965 while (r10_bio) {
1966 r10bio_t *rb2 = r10_bio;
1967 r10_bio = (r10bio_t*) rb2->master_bio;
1968 rb2->master_bio = NULL;
1969 put_buf(rb2);
1970 }
1971 goto giveup;
1972 }
1973 } else {
1974 /* resync. Schedule a read for every block at this virt offset */
1975 int count = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08001976
NeilBrown78200d42009-02-25 13:18:47 +11001977 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1978
NeilBrown6cce3b22006-01-06 00:20:16 -08001979 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1980 &sync_blocks, mddev->degraded) &&
1981 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1982 /* We can skip this block */
1983 *skipped = 1;
1984 return sync_blocks + sectors_skipped;
1985 }
1986 if (sync_blocks < max_sync)
1987 max_sync = sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
1989
Linus Torvalds1da177e2005-04-16 15:20:36 -07001990 r10_bio->mddev = mddev;
1991 atomic_set(&r10_bio->remaining, 0);
NeilBrown6cce3b22006-01-06 00:20:16 -08001992 raise_barrier(conf, 0);
1993 conf->next_resync = sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994
1995 r10_bio->master_bio = NULL;
1996 r10_bio->sector = sector_nr;
1997 set_bit(R10BIO_IsSync, &r10_bio->state);
1998 raid10_find_phys(conf, r10_bio);
1999 r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
2000
2001 for (i=0; i<conf->copies; i++) {
2002 int d = r10_bio->devs[i].devnum;
2003 bio = r10_bio->devs[i].bio;
2004 bio->bi_end_io = NULL;
NeilBrownaf03b8e2007-06-16 10:16:06 -07002005 clear_bit(BIO_UPTODATE, &bio->bi_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 if (conf->mirrors[d].rdev == NULL ||
NeilBrownb2d444d2005-11-08 21:39:31 -08002007 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002008 continue;
2009 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2010 atomic_inc(&r10_bio->remaining);
2011 bio->bi_next = biolist;
2012 biolist = bio;
2013 bio->bi_private = r10_bio;
2014 bio->bi_end_io = end_sync_read;
NeilBrown802ba062006-12-13 00:34:13 -08002015 bio->bi_rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002016 bio->bi_sector = r10_bio->devs[i].addr +
2017 conf->mirrors[d].rdev->data_offset;
2018 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
2019 count++;
2020 }
2021
2022 if (count < 2) {
2023 for (i=0; i<conf->copies; i++) {
2024 int d = r10_bio->devs[i].devnum;
2025 if (r10_bio->devs[i].bio->bi_end_io)
2026 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
2027 }
2028 put_buf(r10_bio);
2029 biolist = NULL;
2030 goto giveup;
2031 }
2032 }
2033
2034 for (bio = biolist; bio ; bio=bio->bi_next) {
2035
2036 bio->bi_flags &= ~(BIO_POOL_MASK - 1);
2037 if (bio->bi_end_io)
2038 bio->bi_flags |= 1 << BIO_UPTODATE;
2039 bio->bi_vcnt = 0;
2040 bio->bi_idx = 0;
2041 bio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042 bio->bi_size = 0;
2043 }
2044
2045 nr_sectors = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08002046 if (sector_nr + max_sync < max_sector)
2047 max_sector = sector_nr + max_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048 do {
2049 struct page *page;
2050 int len = PAGE_SIZE;
2051 disk = 0;
2052 if (sector_nr + (len>>9) > max_sector)
2053 len = (max_sector - sector_nr) << 9;
2054 if (len == 0)
2055 break;
2056 for (bio= biolist ; bio ; bio=bio->bi_next) {
2057 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2058 if (bio_add_page(bio, page, len, 0) == 0) {
2059 /* stop here */
2060 struct bio *bio2;
2061 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2062 for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) {
2063 /* remove last page from this bio */
2064 bio2->bi_vcnt--;
2065 bio2->bi_size -= len;
2066 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
2067 }
2068 goto bio_full;
2069 }
2070 disk = i;
2071 }
2072 nr_sectors += len>>9;
2073 sector_nr += len>>9;
2074 } while (biolist->bi_vcnt < RESYNC_PAGES);
2075 bio_full:
2076 r10_bio->sectors = nr_sectors;
2077
2078 while (biolist) {
2079 bio = biolist;
2080 biolist = biolist->bi_next;
2081
2082 bio->bi_next = NULL;
2083 r10_bio = bio->bi_private;
2084 r10_bio->sectors = nr_sectors;
2085
2086 if (bio->bi_end_io == end_sync_read) {
2087 md_sync_acct(bio->bi_bdev, nr_sectors);
2088 generic_make_request(bio);
2089 }
2090 }
2091
NeilBrown57afd892005-06-21 17:17:13 -07002092 if (sectors_skipped)
2093 /* pretend they weren't skipped, it makes
2094 * no important difference in this case
2095 */
2096 md_done_sync(mddev, sectors_skipped, 1);
2097
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098 return sectors_skipped + nr_sectors;
2099 giveup:
2100 /* There is nowhere to write, so all non-sync
2101 * drives must be failed, so try the next chunk...
2102 */
NeilBrown09b40682009-02-25 13:18:47 +11002103 if (sector_nr + max_sync < max_sector)
2104 max_sector = sector_nr + max_sync;
2105
2106 sectors_skipped += (max_sector - sector_nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107 chunks_skipped ++;
2108 sector_nr = max_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 goto skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002110}
2111
Dan Williams80c3a6c2009-03-17 18:10:40 -07002112static sector_t
2113raid10_size(mddev_t *mddev, sector_t sectors, int raid_disks)
2114{
2115 sector_t size;
NeilBrown070ec552009-06-16 16:54:21 +10002116 conf_t *conf = mddev->private;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002117
2118 if (!raid_disks)
NeilBrown84707f32010-03-16 17:23:35 +11002119 raid_disks = conf->raid_disks;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002120 if (!sectors)
Trela, Maciejdab8b292010-03-08 16:02:45 +11002121 sectors = conf->dev_sectors;
Dan Williams80c3a6c2009-03-17 18:10:40 -07002122
2123 size = sectors >> conf->chunk_shift;
2124 sector_div(size, conf->far_copies);
2125 size = size * raid_disks;
2126 sector_div(size, conf->near_copies);
2127
2128 return size << conf->chunk_shift;
2129}
2130
Trela, Maciejdab8b292010-03-08 16:02:45 +11002131
2132static conf_t *setup_conf(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133{
Trela, Maciejdab8b292010-03-08 16:02:45 +11002134 conf_t *conf = NULL;
NeilBrownc93983b2006-06-26 00:27:41 -07002135 int nc, fc, fo;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136 sector_t stride, size;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002137 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138
Maciej Trelaf73ea872010-06-16 11:46:29 +01002139 if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
2140 !is_power_of_2(mddev->new_chunk_sectors)) {
NeilBrown128595e2010-05-03 14:47:14 +10002141 printk(KERN_ERR "md/raid10:%s: chunk size must be "
2142 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
2143 mdname(mddev), PAGE_SIZE);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002144 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002145 }
NeilBrown2604b702006-01-06 00:20:36 -08002146
Maciej Trelaf73ea872010-06-16 11:46:29 +01002147 nc = mddev->new_layout & 255;
2148 fc = (mddev->new_layout >> 8) & 255;
2149 fo = mddev->new_layout & (1<<16);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002150
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151 if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
Maciej Trelaf73ea872010-06-16 11:46:29 +01002152 (mddev->new_layout >> 17)) {
NeilBrown128595e2010-05-03 14:47:14 +10002153 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
Maciej Trelaf73ea872010-06-16 11:46:29 +01002154 mdname(mddev), mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 goto out;
2156 }
Trela, Maciejdab8b292010-03-08 16:02:45 +11002157
2158 err = -ENOMEM;
NeilBrown4443ae12006-01-06 00:20:28 -08002159 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002160 if (!conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002161 goto out;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002162
NeilBrown4443ae12006-01-06 00:20:28 -08002163 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
Trela, Maciejdab8b292010-03-08 16:02:45 +11002164 GFP_KERNEL);
2165 if (!conf->mirrors)
2166 goto out;
NeilBrown4443ae12006-01-06 00:20:28 -08002167
2168 conf->tmppage = alloc_page(GFP_KERNEL);
2169 if (!conf->tmppage)
Trela, Maciejdab8b292010-03-08 16:02:45 +11002170 goto out;
2171
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172
NeilBrown64a742b2007-02-28 20:11:18 -08002173 conf->raid_disks = mddev->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174 conf->near_copies = nc;
2175 conf->far_copies = fc;
2176 conf->copies = nc*fc;
NeilBrownc93983b2006-06-26 00:27:41 -07002177 conf->far_offset = fo;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002178 conf->chunk_mask = mddev->new_chunk_sectors - 1;
2179 conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
2180
2181 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
2182 r10bio_pool_free, conf);
2183 if (!conf->r10bio_pool)
2184 goto out;
2185
Andre Noll58c0fed2009-03-31 14:33:13 +11002186 size = mddev->dev_sectors >> conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08002187 sector_div(size, fc);
2188 size = size * conf->raid_disks;
2189 sector_div(size, nc);
2190 /* 'size' is now the number of chunks in the array */
2191 /* calculate "used chunks per device" in 'stride' */
2192 stride = size * conf->copies;
NeilBrownaf03b8e2007-06-16 10:16:06 -07002193
2194 /* We need to round up when dividing by raid_disks to
2195 * get the stride size.
2196 */
2197 stride += conf->raid_disks - 1;
NeilBrown64a742b2007-02-28 20:11:18 -08002198 sector_div(stride, conf->raid_disks);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002199
2200 conf->dev_sectors = stride << conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08002201
NeilBrownc93983b2006-06-26 00:27:41 -07002202 if (fo)
NeilBrown64a742b2007-02-28 20:11:18 -08002203 stride = 1;
2204 else
NeilBrownc93983b2006-06-26 00:27:41 -07002205 sector_div(stride, fc);
NeilBrown64a742b2007-02-28 20:11:18 -08002206 conf->stride = stride << conf->chunk_shift;
2207
Linus Torvalds1da177e2005-04-16 15:20:36 -07002208
Neil Browne7e72bf2008-05-14 16:05:54 -07002209 spin_lock_init(&conf->device_lock);
Trela, Maciejdab8b292010-03-08 16:02:45 +11002210 INIT_LIST_HEAD(&conf->retry_list);
2211
2212 spin_lock_init(&conf->resync_lock);
2213 init_waitqueue_head(&conf->wait_barrier);
2214
2215 conf->thread = md_register_thread(raid10d, mddev, NULL);
2216 if (!conf->thread)
2217 goto out;
2218
Trela, Maciejdab8b292010-03-08 16:02:45 +11002219 conf->mddev = mddev;
2220 return conf;
2221
2222 out:
NeilBrown128595e2010-05-03 14:47:14 +10002223 printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
Trela, Maciejdab8b292010-03-08 16:02:45 +11002224 mdname(mddev));
2225 if (conf) {
2226 if (conf->r10bio_pool)
2227 mempool_destroy(conf->r10bio_pool);
2228 kfree(conf->mirrors);
2229 safe_put_page(conf->tmppage);
2230 kfree(conf);
2231 }
2232 return ERR_PTR(err);
2233}
2234
2235static int run(mddev_t *mddev)
2236{
2237 conf_t *conf;
2238 int i, disk_idx, chunk_size;
2239 mirror_info_t *disk;
2240 mdk_rdev_t *rdev;
2241 sector_t size;
2242
2243 /*
2244 * copy the already verified devices into our private RAID10
2245 * bookkeeping area. [whatever we allocate in run(),
2246 * should be freed in stop()]
2247 */
2248
2249 if (mddev->private == NULL) {
2250 conf = setup_conf(mddev);
2251 if (IS_ERR(conf))
2252 return PTR_ERR(conf);
2253 mddev->private = conf;
2254 }
2255 conf = mddev->private;
2256 if (!conf)
2257 goto out;
2258
Neil Browne7e72bf2008-05-14 16:05:54 -07002259 mddev->queue->queue_lock = &conf->device_lock;
2260
Trela, Maciejdab8b292010-03-08 16:02:45 +11002261 mddev->thread = conf->thread;
2262 conf->thread = NULL;
2263
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10002264 chunk_size = mddev->chunk_sectors << 9;
2265 blk_queue_io_min(mddev->queue, chunk_size);
2266 if (conf->raid_disks % conf->near_copies)
2267 blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
2268 else
2269 blk_queue_io_opt(mddev->queue, chunk_size *
2270 (conf->raid_disks / conf->near_copies));
2271
Cheng Renquan159ec1f2009-01-09 08:31:08 +11002272 list_for_each_entry(rdev, &mddev->disks, same_set) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273 disk_idx = rdev->raid_disk;
NeilBrown84707f32010-03-16 17:23:35 +11002274 if (disk_idx >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07002275 || disk_idx < 0)
2276 continue;
2277 disk = conf->mirrors + disk_idx;
2278
2279 disk->rdev = rdev;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10002280 disk_stack_limits(mddev->gendisk, rdev->bdev,
2281 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282 /* as we don't honour merge_bvec_fn, we must never risk
NeilBrown627a2d32010-03-08 16:44:38 +11002283 * violating it, so limit max_segments to 1 lying
2284 * within a single page.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002285 */
NeilBrown627a2d32010-03-08 16:44:38 +11002286 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2287 blk_queue_max_segments(mddev->queue, 1);
2288 blk_queue_segment_boundary(mddev->queue,
2289 PAGE_CACHE_SIZE - 1);
2290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002291
2292 disk->head_position = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002293 }
NeilBrown6d508242005-09-09 16:24:03 -07002294 /* need to check that every block has at least one working mirror */
2295 if (!enough(conf)) {
NeilBrown128595e2010-05-03 14:47:14 +10002296 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
NeilBrown6d508242005-09-09 16:24:03 -07002297 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002298 goto out_free_conf;
2299 }
2300
2301 mddev->degraded = 0;
2302 for (i = 0; i < conf->raid_disks; i++) {
2303
2304 disk = conf->mirrors + i;
2305
NeilBrown5fd6c1d2006-06-26 00:27:40 -07002306 if (!disk->rdev ||
NeilBrown2e333e82006-10-21 10:24:07 -07002307 !test_bit(In_sync, &disk->rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308 disk->head_position = 0;
2309 mddev->degraded++;
Neil Brown8c2e8702008-06-28 08:30:52 +10002310 if (disk->rdev)
2311 conf->fullsync = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002312 }
2313 }
2314
Andre Noll8c6ac862009-06-18 08:48:06 +10002315 if (mddev->recovery_cp != MaxSector)
NeilBrown128595e2010-05-03 14:47:14 +10002316 printk(KERN_NOTICE "md/raid10:%s: not clean"
Andre Noll8c6ac862009-06-18 08:48:06 +10002317 " -- starting background reconstruction\n",
2318 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002319 printk(KERN_INFO
NeilBrown128595e2010-05-03 14:47:14 +10002320 "md/raid10:%s: active with %d out of %d devices\n",
NeilBrown84707f32010-03-16 17:23:35 +11002321 mdname(mddev), conf->raid_disks - mddev->degraded,
2322 conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002323 /*
2324 * Ok, everything is just fine now
2325 */
Trela, Maciejdab8b292010-03-08 16:02:45 +11002326 mddev->dev_sectors = conf->dev_sectors;
2327 size = raid10_size(mddev, 0, 0);
2328 md_set_array_sectors(mddev, size);
2329 mddev->resync_max_sectors = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002330
NeilBrown0d129222006-10-03 01:15:54 -07002331 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
2332 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -07002333
Linus Torvalds1da177e2005-04-16 15:20:36 -07002334 /* Calculate max read-ahead size.
2335 * We need to readahead at least twice a whole stripe....
2336 * maybe...
2337 */
2338 {
Andre Noll9d8f0362009-06-18 08:45:01 +10002339 int stripe = conf->raid_disks *
2340 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002341 stripe /= conf->near_copies;
2342 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
2343 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
2344 }
2345
NeilBrown84707f32010-03-16 17:23:35 +11002346 if (conf->near_copies < conf->raid_disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
Andre Nollac5e7112009-08-03 10:59:47 +10002348 md_integrity_register(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002349 return 0;
2350
2351out_free_conf:
NeilBrown589a5942010-12-09 17:02:14 +11002352 md_unregister_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353 if (conf->r10bio_pool)
2354 mempool_destroy(conf->r10bio_pool);
NeilBrown1345b1d2006-01-06 00:20:40 -08002355 safe_put_page(conf->tmppage);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002356 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357 kfree(conf);
2358 mddev->private = NULL;
2359out:
2360 return -EIO;
2361}
2362
2363static int stop(mddev_t *mddev)
2364{
NeilBrown070ec552009-06-16 16:54:21 +10002365 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366
NeilBrown409c57f2009-03-31 14:39:39 +11002367 raise_barrier(conf, 0);
2368 lower_barrier(conf);
2369
Linus Torvalds1da177e2005-04-16 15:20:36 -07002370 md_unregister_thread(mddev->thread);
2371 mddev->thread = NULL;
2372 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2373 if (conf->r10bio_pool)
2374 mempool_destroy(conf->r10bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002375 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376 kfree(conf);
2377 mddev->private = NULL;
2378 return 0;
2379}
2380
NeilBrown6cce3b22006-01-06 00:20:16 -08002381static void raid10_quiesce(mddev_t *mddev, int state)
2382{
NeilBrown070ec552009-06-16 16:54:21 +10002383 conf_t *conf = mddev->private;
NeilBrown6cce3b22006-01-06 00:20:16 -08002384
2385 switch(state) {
2386 case 1:
2387 raise_barrier(conf, 0);
2388 break;
2389 case 0:
2390 lower_barrier(conf);
2391 break;
2392 }
NeilBrown6cce3b22006-01-06 00:20:16 -08002393}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002394
Trela, Maciejdab8b292010-03-08 16:02:45 +11002395static void *raid10_takeover_raid0(mddev_t *mddev)
2396{
2397 mdk_rdev_t *rdev;
2398 conf_t *conf;
2399
2400 if (mddev->degraded > 0) {
NeilBrown128595e2010-05-03 14:47:14 +10002401 printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
2402 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11002403 return ERR_PTR(-EINVAL);
2404 }
2405
Trela, Maciejdab8b292010-03-08 16:02:45 +11002406 /* Set new parameters */
2407 mddev->new_level = 10;
2408 /* new layout: far_copies = 1, near_copies = 2 */
2409 mddev->new_layout = (1<<8) + 2;
2410 mddev->new_chunk_sectors = mddev->chunk_sectors;
2411 mddev->delta_disks = mddev->raid_disks;
Trela, Maciejdab8b292010-03-08 16:02:45 +11002412 mddev->raid_disks *= 2;
2413 /* make sure it will be not marked as dirty */
2414 mddev->recovery_cp = MaxSector;
2415
2416 conf = setup_conf(mddev);
Krzysztof Wojcik02214dc2011-02-04 14:18:26 +01002417 if (!IS_ERR(conf)) {
NeilBrowne93f68a2010-06-15 09:36:03 +01002418 list_for_each_entry(rdev, &mddev->disks, same_set)
2419 if (rdev->raid_disk >= 0)
2420 rdev->new_raid_disk = rdev->raid_disk * 2;
Krzysztof Wojcik02214dc2011-02-04 14:18:26 +01002421 conf->barrier = 1;
2422 }
2423
Trela, Maciejdab8b292010-03-08 16:02:45 +11002424 return conf;
2425}
2426
2427static void *raid10_takeover(mddev_t *mddev)
2428{
2429 struct raid0_private_data *raid0_priv;
2430
2431 /* raid10 can take over:
2432 * raid0 - providing it has only two drives
2433 */
2434 if (mddev->level == 0) {
2435 /* for raid0 takeover only one zone is supported */
2436 raid0_priv = mddev->private;
2437 if (raid0_priv->nr_strip_zones > 1) {
NeilBrown128595e2010-05-03 14:47:14 +10002438 printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
2439 " with more than one zone.\n",
2440 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11002441 return ERR_PTR(-EINVAL);
2442 }
2443 return raid10_takeover_raid0(mddev);
2444 }
2445 return ERR_PTR(-EINVAL);
2446}
2447
NeilBrown2604b702006-01-06 00:20:36 -08002448static struct mdk_personality raid10_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449{
2450 .name = "raid10",
NeilBrown2604b702006-01-06 00:20:36 -08002451 .level = 10,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002452 .owner = THIS_MODULE,
2453 .make_request = make_request,
2454 .run = run,
2455 .stop = stop,
2456 .status = status,
2457 .error_handler = error,
2458 .hot_add_disk = raid10_add_disk,
2459 .hot_remove_disk= raid10_remove_disk,
2460 .spare_active = raid10_spare_active,
2461 .sync_request = sync_request,
NeilBrown6cce3b22006-01-06 00:20:16 -08002462 .quiesce = raid10_quiesce,
Dan Williams80c3a6c2009-03-17 18:10:40 -07002463 .size = raid10_size,
Trela, Maciejdab8b292010-03-08 16:02:45 +11002464 .takeover = raid10_takeover,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465};
2466
2467static int __init raid_init(void)
2468{
NeilBrown2604b702006-01-06 00:20:36 -08002469 return register_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470}
2471
2472static void raid_exit(void)
2473{
NeilBrown2604b702006-01-06 00:20:36 -08002474 unregister_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475}
2476
2477module_init(raid_init);
2478module_exit(raid_exit);
2479MODULE_LICENSE("GPL");
NeilBrown0efb9e62009-12-14 12:49:58 +11002480MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002481MODULE_ALIAS("md-personality-9"); /* RAID10 */
NeilBrownd9d166c2006-01-06 00:20:51 -08002482MODULE_ALIAS("md-raid10");
NeilBrown2604b702006-01-06 00:20:36 -08002483MODULE_ALIAS("md-level-10");