blob: 3540316886f2bca71a7bd943c4cf98de610ac1ae [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 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -03008 * Base on code in raid1.c. See raid1.c for further copyright information.
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
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>
Paul Gortmaker056075c2011-07-03 13:58:33 -040024#include <linux/module.h>
NeilBrownbff61972009-03-31 14:33:13 +110025#include <linux/seq_file.h>
Christian Dietrich8bda4702011-07-27 11:00:36 +100026#include <linux/ratelimit.h>
NeilBrown43b2e5d2009-03-31 14:33:13 +110027#include "md.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110028#include "raid10.h"
Trela, Maciejdab8b292010-03-08 16:02:45 +110029#include "raid0.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110030#include "bitmap.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32/*
33 * RAID10 provides a combination of RAID0 and RAID1 functionality.
34 * The layout of data is defined by
35 * chunk_size
36 * raid_disks
37 * near_copies (stored in low byte of layout)
38 * far_copies (stored in second byte of layout)
NeilBrownc93983b2006-06-26 00:27:41 -070039 * far_offset (stored in bit 16 of layout )
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 *
41 * The data to be stored is divided into chunks using chunksize.
42 * Each device is divided into far_copies sections.
43 * In each section, chunks are laid out in a style similar to raid0, but
44 * near_copies copies of each chunk is stored (each on a different drive).
45 * The starting device for each section is offset near_copies from the starting
46 * device of the previous section.
NeilBrownc93983b2006-06-26 00:27:41 -070047 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 * drive.
49 * near_copies and far_copies must be at least one, and their product is at most
50 * raid_disks.
NeilBrownc93983b2006-06-26 00:27:41 -070051 *
52 * If far_offset is true, then the far_copies are handled a bit differently.
53 * The copies are still in different stripes, but instead of be very far apart
54 * on disk, there are adjacent stripes.
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 */
56
57/*
58 * Number of guaranteed r10bios in case of extreme VM load:
59 */
60#define NR_RAID10_BIOS 256
61
NeilBrown34db0cd2011-10-11 16:50:01 +110062/* When there are this many requests queue to be written by
63 * the raid10 thread, we become 'congested' to provide back-pressure
64 * for writeback.
65 */
66static int max_queued_requests = 1024;
67
NeilBrowne879a872011-10-11 16:49:02 +110068static void allow_barrier(struct r10conf *conf);
69static void lower_barrier(struct r10conf *conf);
NeilBrownfae8cc52012-02-14 11:10:10 +110070static int enough(struct r10conf *conf, int ignore);
NeilBrown0a27ec92006-01-06 00:20:13 -080071
Al Virodd0fc662005-10-07 07:46:04 +010072static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
NeilBrowne879a872011-10-11 16:49:02 +110074 struct r10conf *conf = data;
NeilBrown9f2c9d12011-10-11 16:48:43 +110075 int size = offsetof(struct r10bio, devs[conf->copies]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
NeilBrown69335ef2011-12-23 10:17:54 +110077 /* allocate a r10bio with room for raid_disks entries in the
78 * bios array */
Jens Axboe7eaceac2011-03-10 08:52:07 +010079 return kzalloc(size, gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080}
81
82static void r10bio_pool_free(void *r10_bio, void *data)
83{
84 kfree(r10_bio);
85}
86
NeilBrown0310fa22008-08-05 15:54:14 +100087/* Maximum size of each resync request */
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#define RESYNC_BLOCK_SIZE (64*1024)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
NeilBrown0310fa22008-08-05 15:54:14 +100090/* amount of memory to reserve for resync requests */
91#define RESYNC_WINDOW (1024*1024)
92/* maximum number of concurrent requests, memory permitting */
93#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95/*
96 * When performing a resync, we need to read and compare, so
97 * we need as many pages are there are copies.
98 * When performing a recovery, we need 2 bios, one for read,
99 * one for write (we recover only one drive per r10buf)
100 *
101 */
Al Virodd0fc662005-10-07 07:46:04 +0100102static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
NeilBrowne879a872011-10-11 16:49:02 +1100104 struct r10conf *conf = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 struct page *page;
NeilBrown9f2c9d12011-10-11 16:48:43 +1100106 struct r10bio *r10_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 struct bio *bio;
108 int i, j;
109 int nalloc;
110
111 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
Jens Axboe7eaceac2011-03-10 08:52:07 +0100112 if (!r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
116 nalloc = conf->copies; /* resync */
117 else
118 nalloc = 2; /* recovery */
119
120 /*
121 * Allocate bios.
122 */
123 for (j = nalloc ; j-- ; ) {
NeilBrown67465572010-10-26 17:33:54 +1100124 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (!bio)
126 goto out_free_bio;
127 r10_bio->devs[j].bio = bio;
NeilBrown69335ef2011-12-23 10:17:54 +1100128 if (!conf->have_replacement)
129 continue;
130 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
131 if (!bio)
132 goto out_free_bio;
133 r10_bio->devs[j].repl_bio = bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 }
135 /*
136 * Allocate RESYNC_PAGES data pages and attach them
137 * where needed.
138 */
139 for (j = 0 ; j < nalloc; j++) {
NeilBrown69335ef2011-12-23 10:17:54 +1100140 struct bio *rbio = r10_bio->devs[j].repl_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 bio = r10_bio->devs[j].bio;
142 for (i = 0; i < RESYNC_PAGES; i++) {
Namhyung Kimc65060a2011-07-18 17:38:49 +1000143 if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
144 &conf->mddev->recovery)) {
145 /* we can share bv_page's during recovery */
146 struct bio *rbio = r10_bio->devs[0].bio;
147 page = rbio->bi_io_vec[i].bv_page;
148 get_page(page);
149 } else
150 page = alloc_page(gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 if (unlikely(!page))
152 goto out_free_pages;
153
154 bio->bi_io_vec[i].bv_page = page;
NeilBrown69335ef2011-12-23 10:17:54 +1100155 if (rbio)
156 rbio->bi_io_vec[i].bv_page = page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 }
158 }
159
160 return r10_bio;
161
162out_free_pages:
163 for ( ; i > 0 ; i--)
NeilBrown1345b1d2006-01-06 00:20:40 -0800164 safe_put_page(bio->bi_io_vec[i-1].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 while (j--)
166 for (i = 0; i < RESYNC_PAGES ; i++)
NeilBrown1345b1d2006-01-06 00:20:40 -0800167 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 j = -1;
169out_free_bio:
NeilBrown69335ef2011-12-23 10:17:54 +1100170 while (++j < nalloc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 bio_put(r10_bio->devs[j].bio);
NeilBrown69335ef2011-12-23 10:17:54 +1100172 if (r10_bio->devs[j].repl_bio)
173 bio_put(r10_bio->devs[j].repl_bio);
174 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 r10bio_pool_free(r10_bio, conf);
176 return NULL;
177}
178
179static void r10buf_pool_free(void *__r10_bio, void *data)
180{
181 int i;
NeilBrowne879a872011-10-11 16:49:02 +1100182 struct r10conf *conf = data;
NeilBrown9f2c9d12011-10-11 16:48:43 +1100183 struct r10bio *r10bio = __r10_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 int j;
185
186 for (j=0; j < conf->copies; j++) {
187 struct bio *bio = r10bio->devs[j].bio;
188 if (bio) {
189 for (i = 0; i < RESYNC_PAGES; i++) {
NeilBrown1345b1d2006-01-06 00:20:40 -0800190 safe_put_page(bio->bi_io_vec[i].bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 bio->bi_io_vec[i].bv_page = NULL;
192 }
193 bio_put(bio);
194 }
NeilBrown69335ef2011-12-23 10:17:54 +1100195 bio = r10bio->devs[j].repl_bio;
196 if (bio)
197 bio_put(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 }
199 r10bio_pool_free(r10bio, conf);
200}
201
NeilBrowne879a872011-10-11 16:49:02 +1100202static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
204 int i;
205
206 for (i = 0; i < conf->copies; i++) {
207 struct bio **bio = & r10_bio->devs[i].bio;
NeilBrown749c55e2011-07-28 11:39:24 +1000208 if (!BIO_SPECIAL(*bio))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 bio_put(*bio);
210 *bio = NULL;
NeilBrown69335ef2011-12-23 10:17:54 +1100211 bio = &r10_bio->devs[i].repl_bio;
212 if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
213 bio_put(*bio);
214 *bio = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 }
216}
217
NeilBrown9f2c9d12011-10-11 16:48:43 +1100218static void free_r10bio(struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
NeilBrowne879a872011-10-11 16:49:02 +1100220 struct r10conf *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 put_all_bios(conf, r10_bio);
223 mempool_free(r10_bio, conf->r10bio_pool);
224}
225
NeilBrown9f2c9d12011-10-11 16:48:43 +1100226static void put_buf(struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227{
NeilBrowne879a872011-10-11 16:49:02 +1100228 struct r10conf *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 mempool_free(r10_bio, conf->r10buf_pool);
231
NeilBrown0a27ec92006-01-06 00:20:13 -0800232 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
NeilBrown9f2c9d12011-10-11 16:48:43 +1100235static void reschedule_retry(struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236{
237 unsigned long flags;
NeilBrownfd01b882011-10-11 16:47:53 +1100238 struct mddev *mddev = r10_bio->mddev;
NeilBrowne879a872011-10-11 16:49:02 +1100239 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241 spin_lock_irqsave(&conf->device_lock, flags);
242 list_add(&r10_bio->retry_list, &conf->retry_list);
NeilBrown4443ae12006-01-06 00:20:28 -0800243 conf->nr_queued ++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 spin_unlock_irqrestore(&conf->device_lock, flags);
245
Arthur Jones388667b2008-07-25 12:03:38 -0700246 /* wake up frozen array... */
247 wake_up(&conf->wait_barrier);
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 md_wakeup_thread(mddev->thread);
250}
251
252/*
253 * raid_end_bio_io() is called when we have finished servicing a mirrored
254 * operation and are ready to return a success/failure code to the buffer
255 * cache layer.
256 */
NeilBrown9f2c9d12011-10-11 16:48:43 +1100257static void raid_end_bio_io(struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258{
259 struct bio *bio = r10_bio->master_bio;
NeilBrown856e08e2011-07-28 11:39:23 +1000260 int done;
NeilBrowne879a872011-10-11 16:49:02 +1100261 struct r10conf *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
NeilBrown856e08e2011-07-28 11:39:23 +1000263 if (bio->bi_phys_segments) {
264 unsigned long flags;
265 spin_lock_irqsave(&conf->device_lock, flags);
266 bio->bi_phys_segments--;
267 done = (bio->bi_phys_segments == 0);
268 spin_unlock_irqrestore(&conf->device_lock, flags);
269 } else
270 done = 1;
271 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
272 clear_bit(BIO_UPTODATE, &bio->bi_flags);
273 if (done) {
274 bio_endio(bio, 0);
275 /*
276 * Wake up any possible resync thread that waits for the device
277 * to go idle.
278 */
279 allow_barrier(conf);
280 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 free_r10bio(r10_bio);
282}
283
284/*
285 * Update disk head position estimator based on IRQ completion info.
286 */
NeilBrown9f2c9d12011-10-11 16:48:43 +1100287static inline void update_head_pos(int slot, struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288{
NeilBrowne879a872011-10-11 16:49:02 +1100289 struct r10conf *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
292 r10_bio->devs[slot].addr + (r10_bio->sectors);
293}
294
Namhyung Kim778ca012011-07-18 17:38:47 +1000295/*
296 * Find the disk number which triggered given bio
297 */
NeilBrowne879a872011-10-11 16:49:02 +1100298static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
NeilBrown69335ef2011-12-23 10:17:54 +1100299 struct bio *bio, int *slotp, int *replp)
Namhyung Kim778ca012011-07-18 17:38:47 +1000300{
301 int slot;
NeilBrown69335ef2011-12-23 10:17:54 +1100302 int repl = 0;
Namhyung Kim778ca012011-07-18 17:38:47 +1000303
NeilBrown69335ef2011-12-23 10:17:54 +1100304 for (slot = 0; slot < conf->copies; slot++) {
Namhyung Kim778ca012011-07-18 17:38:47 +1000305 if (r10_bio->devs[slot].bio == bio)
306 break;
NeilBrown69335ef2011-12-23 10:17:54 +1100307 if (r10_bio->devs[slot].repl_bio == bio) {
308 repl = 1;
309 break;
310 }
311 }
Namhyung Kim778ca012011-07-18 17:38:47 +1000312
313 BUG_ON(slot == conf->copies);
314 update_head_pos(slot, r10_bio);
315
NeilBrown749c55e2011-07-28 11:39:24 +1000316 if (slotp)
317 *slotp = slot;
NeilBrown69335ef2011-12-23 10:17:54 +1100318 if (replp)
319 *replp = repl;
Namhyung Kim778ca012011-07-18 17:38:47 +1000320 return r10_bio->devs[slot].devnum;
321}
322
NeilBrown6712ecf2007-09-27 12:47:43 +0200323static void raid10_end_read_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324{
325 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
NeilBrown9f2c9d12011-10-11 16:48:43 +1100326 struct r10bio *r10_bio = bio->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 int slot, dev;
NeilBrownabbf0982011-12-23 10:17:54 +1100328 struct md_rdev *rdev;
NeilBrowne879a872011-10-11 16:49:02 +1100329 struct r10conf *conf = r10_bio->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
332 slot = r10_bio->read_slot;
333 dev = r10_bio->devs[slot].devnum;
NeilBrownabbf0982011-12-23 10:17:54 +1100334 rdev = r10_bio->devs[slot].rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 /*
336 * this branch is our 'one mirror IO has finished' event handler:
337 */
NeilBrown4443ae12006-01-06 00:20:28 -0800338 update_head_pos(slot, r10_bio);
339
340 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 /*
342 * Set R10BIO_Uptodate in our master bio, so that
343 * we will return a good error code to the higher
344 * levels even if IO on some other mirrored buffer fails.
345 *
346 * The 'master' represents the composite IO operation to
347 * user-side. So if something waits for IO, then it will
348 * wait for the 'master' bio.
349 */
350 set_bit(R10BIO_Uptodate, &r10_bio->state);
NeilBrownfae8cc52012-02-14 11:10:10 +1100351 } else {
352 /* If all other devices that store this block have
353 * failed, we want to return the error upwards rather
354 * than fail the last device. Here we redefine
355 * "uptodate" to mean "Don't want to retry"
356 */
357 unsigned long flags;
358 spin_lock_irqsave(&conf->device_lock, flags);
359 if (!enough(conf, rdev->raid_disk))
360 uptodate = 1;
361 spin_unlock_irqrestore(&conf->device_lock, flags);
362 }
363 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 raid_end_bio_io(r10_bio);
NeilBrownabbf0982011-12-23 10:17:54 +1100365 rdev_dec_pending(rdev, conf->mddev);
NeilBrown4443ae12006-01-06 00:20:28 -0800366 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 /*
NeilBrown7c4e06f2011-05-11 14:53:17 +1000368 * oops, read error - keep the refcount on the rdev
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 */
370 char b[BDEVNAME_SIZE];
Christian Dietrich8bda4702011-07-27 11:00:36 +1000371 printk_ratelimited(KERN_ERR
372 "md/raid10:%s: %s: rescheduling sector %llu\n",
373 mdname(conf->mddev),
NeilBrownabbf0982011-12-23 10:17:54 +1100374 bdevname(rdev->bdev, b),
Christian Dietrich8bda4702011-07-27 11:00:36 +1000375 (unsigned long long)r10_bio->sector);
NeilBrown856e08e2011-07-28 11:39:23 +1000376 set_bit(R10BIO_ReadError, &r10_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 reschedule_retry(r10_bio);
378 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
380
NeilBrown9f2c9d12011-10-11 16:48:43 +1100381static void close_write(struct r10bio *r10_bio)
NeilBrownbd870a12011-07-28 11:39:24 +1000382{
383 /* clear the bitmap if all writes complete successfully */
384 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
385 r10_bio->sectors,
386 !test_bit(R10BIO_Degraded, &r10_bio->state),
387 0);
388 md_write_end(r10_bio->mddev);
389}
390
NeilBrown9f2c9d12011-10-11 16:48:43 +1100391static void one_write_done(struct r10bio *r10_bio)
NeilBrown19d5f832011-09-10 17:21:17 +1000392{
393 if (atomic_dec_and_test(&r10_bio->remaining)) {
394 if (test_bit(R10BIO_WriteError, &r10_bio->state))
395 reschedule_retry(r10_bio);
396 else {
397 close_write(r10_bio);
398 if (test_bit(R10BIO_MadeGood, &r10_bio->state))
399 reschedule_retry(r10_bio);
400 else
401 raid_end_bio_io(r10_bio);
402 }
403 }
404}
405
NeilBrown6712ecf2007-09-27 12:47:43 +0200406static void raid10_end_write_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407{
408 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
NeilBrown9f2c9d12011-10-11 16:48:43 +1100409 struct r10bio *r10_bio = bio->bi_private;
Namhyung Kim778ca012011-07-18 17:38:47 +1000410 int dev;
NeilBrown749c55e2011-07-28 11:39:24 +1000411 int dec_rdev = 1;
NeilBrowne879a872011-10-11 16:49:02 +1100412 struct r10conf *conf = r10_bio->mddev->private;
NeilBrown475b0322011-12-23 10:17:55 +1100413 int slot, repl;
NeilBrown4ca40c22011-12-23 10:17:55 +1100414 struct md_rdev *rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
NeilBrown475b0322011-12-23 10:17:55 +1100416 dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
NeilBrown475b0322011-12-23 10:17:55 +1100418 if (repl)
419 rdev = conf->mirrors[dev].replacement;
NeilBrown4ca40c22011-12-23 10:17:55 +1100420 if (!rdev) {
421 smp_rmb();
422 repl = 0;
NeilBrown475b0322011-12-23 10:17:55 +1100423 rdev = conf->mirrors[dev].rdev;
NeilBrown4ca40c22011-12-23 10:17:55 +1100424 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 /*
426 * this branch is our 'one mirror IO has finished' event handler:
427 */
NeilBrown6cce3b22006-01-06 00:20:16 -0800428 if (!uptodate) {
NeilBrown475b0322011-12-23 10:17:55 +1100429 if (repl)
430 /* Never record new bad blocks to replacement,
431 * just fail it.
432 */
433 md_error(rdev->mddev, rdev);
434 else {
435 set_bit(WriteErrorSeen, &rdev->flags);
NeilBrownb7044d42011-12-23 10:17:56 +1100436 if (!test_and_set_bit(WantReplacement, &rdev->flags))
437 set_bit(MD_RECOVERY_NEEDED,
438 &rdev->mddev->recovery);
NeilBrown475b0322011-12-23 10:17:55 +1100439 set_bit(R10BIO_WriteError, &r10_bio->state);
440 dec_rdev = 0;
441 }
NeilBrown749c55e2011-07-28 11:39:24 +1000442 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 /*
444 * Set R10BIO_Uptodate in our master bio, so that
445 * we will return a good error code for to the higher
446 * levels even if IO on some other mirrored buffer fails.
447 *
448 * The 'master' represents the composite IO operation to
449 * user-side. So if something waits for IO, then it will
450 * wait for the 'master' bio.
451 */
NeilBrown749c55e2011-07-28 11:39:24 +1000452 sector_t first_bad;
453 int bad_sectors;
454
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 set_bit(R10BIO_Uptodate, &r10_bio->state);
456
NeilBrown749c55e2011-07-28 11:39:24 +1000457 /* Maybe we can clear some bad blocks. */
NeilBrown475b0322011-12-23 10:17:55 +1100458 if (is_badblock(rdev,
NeilBrown749c55e2011-07-28 11:39:24 +1000459 r10_bio->devs[slot].addr,
460 r10_bio->sectors,
461 &first_bad, &bad_sectors)) {
462 bio_put(bio);
NeilBrown475b0322011-12-23 10:17:55 +1100463 if (repl)
464 r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
465 else
466 r10_bio->devs[slot].bio = IO_MADE_GOOD;
NeilBrown749c55e2011-07-28 11:39:24 +1000467 dec_rdev = 0;
468 set_bit(R10BIO_MadeGood, &r10_bio->state);
469 }
470 }
471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 /*
473 *
474 * Let's see if all mirrored write operations have finished
475 * already.
476 */
NeilBrown19d5f832011-09-10 17:21:17 +1000477 one_write_done(r10_bio);
NeilBrown749c55e2011-07-28 11:39:24 +1000478 if (dec_rdev)
479 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480}
481
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482/*
483 * RAID10 layout manager
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300484 * As well as the chunksize and raid_disks count, there are two
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 * parameters: near_copies and far_copies.
486 * near_copies * far_copies must be <= raid_disks.
487 * Normally one of these will be 1.
488 * If both are 1, we get raid0.
489 * If near_copies == raid_disks, we get raid1.
490 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300491 * Chunks are laid out in raid0 style with near_copies copies of the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 * first chunk, followed by near_copies copies of the next chunk and
493 * so on.
494 * If far_copies > 1, then after 1/far_copies of the array has been assigned
495 * as described above, we start again with a device offset of near_copies.
496 * So we effectively have another copy of the whole array further down all
497 * the drives, but with blocks on different drives.
498 * With this layout, and block is never stored twice on the one device.
499 *
500 * raid10_find_phys finds the sector offset of a given virtual sector
NeilBrownc93983b2006-06-26 00:27:41 -0700501 * on each device that it is on.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 *
503 * raid10_find_virt does the reverse mapping, from a device and a
504 * sector offset to a virtual address
505 */
506
NeilBrowne879a872011-10-11 16:49:02 +1100507static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508{
509 int n,f;
510 sector_t sector;
511 sector_t chunk;
512 sector_t stripe;
513 int dev;
514
515 int slot = 0;
516
517 /* now calculate first sector/dev */
518 chunk = r10bio->sector >> conf->chunk_shift;
519 sector = r10bio->sector & conf->chunk_mask;
520
521 chunk *= conf->near_copies;
522 stripe = chunk;
523 dev = sector_div(stripe, conf->raid_disks);
NeilBrownc93983b2006-06-26 00:27:41 -0700524 if (conf->far_offset)
525 stripe *= conf->far_copies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
527 sector += stripe << conf->chunk_shift;
528
529 /* and calculate all the others */
530 for (n=0; n < conf->near_copies; n++) {
531 int d = dev;
532 sector_t s = sector;
533 r10bio->devs[slot].addr = sector;
534 r10bio->devs[slot].devnum = d;
535 slot++;
536
537 for (f = 1; f < conf->far_copies; f++) {
538 d += conf->near_copies;
539 if (d >= conf->raid_disks)
540 d -= conf->raid_disks;
541 s += conf->stride;
542 r10bio->devs[slot].devnum = d;
543 r10bio->devs[slot].addr = s;
544 slot++;
545 }
546 dev++;
547 if (dev >= conf->raid_disks) {
548 dev = 0;
549 sector += (conf->chunk_mask + 1);
550 }
551 }
552 BUG_ON(slot != conf->copies);
553}
554
NeilBrowne879a872011-10-11 16:49:02 +1100555static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556{
557 sector_t offset, chunk, vchunk;
558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 offset = sector & conf->chunk_mask;
NeilBrownc93983b2006-06-26 00:27:41 -0700560 if (conf->far_offset) {
561 int fc;
562 chunk = sector >> conf->chunk_shift;
563 fc = sector_div(chunk, conf->far_copies);
564 dev -= fc * conf->near_copies;
565 if (dev < 0)
566 dev += conf->raid_disks;
567 } else {
NeilBrown64a742b2007-02-28 20:11:18 -0800568 while (sector >= conf->stride) {
NeilBrownc93983b2006-06-26 00:27:41 -0700569 sector -= conf->stride;
570 if (dev < conf->near_copies)
571 dev += conf->raid_disks - conf->near_copies;
572 else
573 dev -= conf->near_copies;
574 }
575 chunk = sector >> conf->chunk_shift;
576 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 vchunk = chunk * conf->raid_disks + dev;
578 sector_div(vchunk, conf->near_copies);
579 return (vchunk << conf->chunk_shift) + offset;
580}
581
582/**
583 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
584 * @q: request queue
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200585 * @bvm: properties of new bio
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 * @biovec: the request that could be merged to it.
587 *
588 * Return amount of bytes we can accept at this offset
NeilBrown050b6612012-03-19 12:46:39 +1100589 * This requires checking for end-of-chunk if near_copies != raid_disks,
590 * and for subordinate merge_bvec_fns if merge_check_needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200592static int raid10_mergeable_bvec(struct request_queue *q,
593 struct bvec_merge_data *bvm,
594 struct bio_vec *biovec)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595{
NeilBrownfd01b882011-10-11 16:47:53 +1100596 struct mddev *mddev = q->queuedata;
NeilBrown050b6612012-03-19 12:46:39 +1100597 struct r10conf *conf = mddev->private;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200598 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 int max;
Andre Noll9d8f0362009-06-18 08:45:01 +1000600 unsigned int chunk_sectors = mddev->chunk_sectors;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200601 unsigned int bio_sectors = bvm->bi_size >> 9;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
NeilBrown050b6612012-03-19 12:46:39 +1100603 if (conf->near_copies < conf->raid_disks) {
604 max = (chunk_sectors - ((sector & (chunk_sectors - 1))
605 + bio_sectors)) << 9;
606 if (max < 0)
607 /* bio_add cannot handle a negative return */
608 max = 0;
609 if (max <= biovec->bv_len && bio_sectors == 0)
610 return biovec->bv_len;
611 } else
612 max = biovec->bv_len;
613
614 if (mddev->merge_check_needed) {
615 struct r10bio r10_bio;
616 int s;
617 r10_bio.sector = sector;
618 raid10_find_phys(conf, &r10_bio);
619 rcu_read_lock();
620 for (s = 0; s < conf->copies; s++) {
621 int disk = r10_bio.devs[s].devnum;
622 struct md_rdev *rdev = rcu_dereference(
623 conf->mirrors[disk].rdev);
624 if (rdev && !test_bit(Faulty, &rdev->flags)) {
625 struct request_queue *q =
626 bdev_get_queue(rdev->bdev);
627 if (q->merge_bvec_fn) {
628 bvm->bi_sector = r10_bio.devs[s].addr
629 + rdev->data_offset;
630 bvm->bi_bdev = rdev->bdev;
631 max = min(max, q->merge_bvec_fn(
632 q, bvm, biovec));
633 }
634 }
635 rdev = rcu_dereference(conf->mirrors[disk].replacement);
636 if (rdev && !test_bit(Faulty, &rdev->flags)) {
637 struct request_queue *q =
638 bdev_get_queue(rdev->bdev);
639 if (q->merge_bvec_fn) {
640 bvm->bi_sector = r10_bio.devs[s].addr
641 + rdev->data_offset;
642 bvm->bi_bdev = rdev->bdev;
643 max = min(max, q->merge_bvec_fn(
644 q, bvm, biovec));
645 }
646 }
647 }
648 rcu_read_unlock();
649 }
650 return max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
653/*
654 * This routine returns the disk from which the requested read should
655 * be done. There is a per-array 'next expected sequential IO' sector
656 * number - if this matches on the next IO then we use the last disk.
657 * There is also a per-disk 'last know head position' sector that is
658 * maintained from IRQ contexts, both the normal and the resync IO
659 * completion handlers update this position correctly. If there is no
660 * perfect sequential match then we pick the disk whose head is closest.
661 *
662 * If there are 2 mirrors in the same 2 devices, performance degrades
663 * because position is mirror, not device based.
664 *
665 * The rdev for the device selected will have nr_pending incremented.
666 */
667
668/*
669 * FIXME: possibly should rethink readbalancing and do it differently
670 * depending on near_copies / far_copies geometry.
671 */
NeilBrown96c3fd12011-12-23 10:17:54 +1100672static struct md_rdev *read_balance(struct r10conf *conf,
673 struct r10bio *r10_bio,
674 int *max_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
NeilBrownaf3a2cd2010-05-08 08:20:17 +1000676 const sector_t this_sector = r10_bio->sector;
NeilBrown56d99122011-05-11 14:27:03 +1000677 int disk, slot;
NeilBrown856e08e2011-07-28 11:39:23 +1000678 int sectors = r10_bio->sectors;
679 int best_good_sectors;
NeilBrown56d99122011-05-11 14:27:03 +1000680 sector_t new_distance, best_dist;
NeilBrownabbf0982011-12-23 10:17:54 +1100681 struct md_rdev *rdev, *best_rdev;
NeilBrown56d99122011-05-11 14:27:03 +1000682 int do_balance;
683 int best_slot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 raid10_find_phys(conf, r10_bio);
686 rcu_read_lock();
NeilBrown56d99122011-05-11 14:27:03 +1000687retry:
NeilBrown856e08e2011-07-28 11:39:23 +1000688 sectors = r10_bio->sectors;
NeilBrown56d99122011-05-11 14:27:03 +1000689 best_slot = -1;
NeilBrownabbf0982011-12-23 10:17:54 +1100690 best_rdev = NULL;
NeilBrown56d99122011-05-11 14:27:03 +1000691 best_dist = MaxSector;
NeilBrown856e08e2011-07-28 11:39:23 +1000692 best_good_sectors = 0;
NeilBrown56d99122011-05-11 14:27:03 +1000693 do_balance = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 /*
695 * Check if we can balance. We can balance on the whole
NeilBrown6cce3b22006-01-06 00:20:16 -0800696 * device if no resync is going on (recovery is ok), or below
697 * the resync window. We take the first readable disk when
698 * above the resync window.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 */
700 if (conf->mddev->recovery_cp < MaxSector
NeilBrown56d99122011-05-11 14:27:03 +1000701 && (this_sector + sectors >= conf->next_resync))
702 do_balance = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
NeilBrown56d99122011-05-11 14:27:03 +1000704 for (slot = 0; slot < conf->copies ; slot++) {
NeilBrown856e08e2011-07-28 11:39:23 +1000705 sector_t first_bad;
706 int bad_sectors;
707 sector_t dev_sector;
708
NeilBrown56d99122011-05-11 14:27:03 +1000709 if (r10_bio->devs[slot].bio == IO_BLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 continue;
NeilBrown56d99122011-05-11 14:27:03 +1000711 disk = r10_bio->devs[slot].devnum;
NeilBrownabbf0982011-12-23 10:17:54 +1100712 rdev = rcu_dereference(conf->mirrors[disk].replacement);
713 if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
NeilBrown050b6612012-03-19 12:46:39 +1100714 test_bit(Unmerged, &rdev->flags) ||
NeilBrownabbf0982011-12-23 10:17:54 +1100715 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
716 rdev = rcu_dereference(conf->mirrors[disk].rdev);
NeilBrown050b6612012-03-19 12:46:39 +1100717 if (rdev == NULL ||
718 test_bit(Faulty, &rdev->flags) ||
719 test_bit(Unmerged, &rdev->flags))
NeilBrownabbf0982011-12-23 10:17:54 +1100720 continue;
721 if (!test_bit(In_sync, &rdev->flags) &&
722 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
NeilBrown56d99122011-05-11 14:27:03 +1000723 continue;
724
NeilBrown856e08e2011-07-28 11:39:23 +1000725 dev_sector = r10_bio->devs[slot].addr;
726 if (is_badblock(rdev, dev_sector, sectors,
727 &first_bad, &bad_sectors)) {
728 if (best_dist < MaxSector)
729 /* Already have a better slot */
730 continue;
731 if (first_bad <= dev_sector) {
732 /* Cannot read here. If this is the
733 * 'primary' device, then we must not read
734 * beyond 'bad_sectors' from another device.
735 */
736 bad_sectors -= (dev_sector - first_bad);
737 if (!do_balance && sectors > bad_sectors)
738 sectors = bad_sectors;
739 if (best_good_sectors > sectors)
740 best_good_sectors = sectors;
741 } else {
742 sector_t good_sectors =
743 first_bad - dev_sector;
744 if (good_sectors > best_good_sectors) {
745 best_good_sectors = good_sectors;
746 best_slot = slot;
NeilBrownabbf0982011-12-23 10:17:54 +1100747 best_rdev = rdev;
NeilBrown856e08e2011-07-28 11:39:23 +1000748 }
749 if (!do_balance)
750 /* Must read from here */
751 break;
752 }
753 continue;
754 } else
755 best_good_sectors = sectors;
756
NeilBrown56d99122011-05-11 14:27:03 +1000757 if (!do_balance)
758 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
NeilBrown22dfdf52005-11-28 13:44:09 -0800760 /* This optimisation is debatable, and completely destroys
761 * sequential read speed for 'far copies' arrays. So only
762 * keep it for 'near' arrays, and review those later.
763 */
NeilBrown56d99122011-05-11 14:27:03 +1000764 if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 break;
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800766
767 /* for far > 1 always use the lowest address */
768 if (conf->far_copies > 1)
NeilBrown56d99122011-05-11 14:27:03 +1000769 new_distance = r10_bio->devs[slot].addr;
Keld Simonsen8ed3a192008-03-04 14:29:34 -0800770 else
NeilBrown56d99122011-05-11 14:27:03 +1000771 new_distance = abs(r10_bio->devs[slot].addr -
772 conf->mirrors[disk].head_position);
773 if (new_distance < best_dist) {
774 best_dist = new_distance;
775 best_slot = slot;
NeilBrownabbf0982011-12-23 10:17:54 +1100776 best_rdev = rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 }
778 }
NeilBrownabbf0982011-12-23 10:17:54 +1100779 if (slot >= conf->copies) {
NeilBrown56d99122011-05-11 14:27:03 +1000780 slot = best_slot;
NeilBrownabbf0982011-12-23 10:17:54 +1100781 rdev = best_rdev;
782 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783
NeilBrown56d99122011-05-11 14:27:03 +1000784 if (slot >= 0) {
NeilBrown56d99122011-05-11 14:27:03 +1000785 atomic_inc(&rdev->nr_pending);
786 if (test_bit(Faulty, &rdev->flags)) {
787 /* Cannot risk returning a device that failed
788 * before we inc'ed nr_pending
789 */
790 rdev_dec_pending(rdev, conf->mddev);
791 goto retry;
792 }
793 r10_bio->read_slot = slot;
794 } else
NeilBrown96c3fd12011-12-23 10:17:54 +1100795 rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 rcu_read_unlock();
NeilBrown856e08e2011-07-28 11:39:23 +1000797 *max_sectors = best_good_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
NeilBrown96c3fd12011-12-23 10:17:54 +1100799 return rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800}
801
NeilBrown0d129222006-10-03 01:15:54 -0700802static int raid10_congested(void *data, int bits)
803{
NeilBrownfd01b882011-10-11 16:47:53 +1100804 struct mddev *mddev = data;
NeilBrowne879a872011-10-11 16:49:02 +1100805 struct r10conf *conf = mddev->private;
NeilBrown0d129222006-10-03 01:15:54 -0700806 int i, ret = 0;
807
NeilBrown34db0cd2011-10-11 16:50:01 +1100808 if ((bits & (1 << BDI_async_congested)) &&
809 conf->pending_count >= max_queued_requests)
810 return 1;
811
NeilBrown3fa841d2009-09-23 18:10:29 +1000812 if (mddev_congested(mddev, bits))
813 return 1;
NeilBrown0d129222006-10-03 01:15:54 -0700814 rcu_read_lock();
NeilBrown84707f32010-03-16 17:23:35 +1100815 for (i = 0; i < conf->raid_disks && ret == 0; i++) {
NeilBrown3cb03002011-10-11 16:45:26 +1100816 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrown0d129222006-10-03 01:15:54 -0700817 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200818 struct request_queue *q = bdev_get_queue(rdev->bdev);
NeilBrown0d129222006-10-03 01:15:54 -0700819
820 ret |= bdi_congested(&q->backing_dev_info, bits);
821 }
822 }
823 rcu_read_unlock();
824 return ret;
825}
826
NeilBrowne879a872011-10-11 16:49:02 +1100827static void flush_pending_writes(struct r10conf *conf)
NeilBrowna35e63e2008-03-04 14:29:29 -0800828{
829 /* Any writes that have been queued but are awaiting
830 * bitmap updates get flushed here.
NeilBrowna35e63e2008-03-04 14:29:29 -0800831 */
NeilBrowna35e63e2008-03-04 14:29:29 -0800832 spin_lock_irq(&conf->device_lock);
833
834 if (conf->pending_bio_list.head) {
835 struct bio *bio;
836 bio = bio_list_get(&conf->pending_bio_list);
NeilBrown34db0cd2011-10-11 16:50:01 +1100837 conf->pending_count = 0;
NeilBrowna35e63e2008-03-04 14:29:29 -0800838 spin_unlock_irq(&conf->device_lock);
839 /* flush any pending bitmap writes to disk
840 * before proceeding w/ I/O */
841 bitmap_unplug(conf->mddev->bitmap);
NeilBrown34db0cd2011-10-11 16:50:01 +1100842 wake_up(&conf->wait_barrier);
NeilBrowna35e63e2008-03-04 14:29:29 -0800843
844 while (bio) { /* submit pending writes */
845 struct bio *next = bio->bi_next;
846 bio->bi_next = NULL;
847 generic_make_request(bio);
848 bio = next;
849 }
NeilBrowna35e63e2008-03-04 14:29:29 -0800850 } else
851 spin_unlock_irq(&conf->device_lock);
NeilBrowna35e63e2008-03-04 14:29:29 -0800852}
Jens Axboe7eaceac2011-03-10 08:52:07 +0100853
NeilBrown0a27ec92006-01-06 00:20:13 -0800854/* Barriers....
855 * Sometimes we need to suspend IO while we do something else,
856 * either some resync/recovery, or reconfigure the array.
857 * To do this we raise a 'barrier'.
858 * The 'barrier' is a counter that can be raised multiple times
859 * to count how many activities are happening which preclude
860 * normal IO.
861 * We can only raise the barrier if there is no pending IO.
862 * i.e. if nr_pending == 0.
863 * We choose only to raise the barrier if no-one is waiting for the
864 * barrier to go down. This means that as soon as an IO request
865 * is ready, no other operations which require a barrier will start
866 * until the IO request has had a chance.
867 *
868 * So: regular IO calls 'wait_barrier'. When that returns there
869 * is no backgroup IO happening, It must arrange to call
870 * allow_barrier when it has finished its IO.
871 * backgroup IO calls must call raise_barrier. Once that returns
872 * there is no normal IO happeing. It must arrange to call
873 * lower_barrier when the particular background IO completes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875
NeilBrowne879a872011-10-11 16:49:02 +1100876static void raise_barrier(struct r10conf *conf, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877{
NeilBrown6cce3b22006-01-06 00:20:16 -0800878 BUG_ON(force && !conf->barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 spin_lock_irq(&conf->resync_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
NeilBrown6cce3b22006-01-06 00:20:16 -0800881 /* Wait until no block IO is waiting (unless 'force') */
882 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
NeilBrownc3b328a2011-04-18 18:25:43 +1000883 conf->resync_lock, );
NeilBrown0a27ec92006-01-06 00:20:13 -0800884
885 /* block any new IO from starting */
886 conf->barrier++;
887
NeilBrownc3b328a2011-04-18 18:25:43 +1000888 /* Now wait for all pending IO to complete */
NeilBrown0a27ec92006-01-06 00:20:13 -0800889 wait_event_lock_irq(conf->wait_barrier,
890 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
NeilBrownc3b328a2011-04-18 18:25:43 +1000891 conf->resync_lock, );
NeilBrown0a27ec92006-01-06 00:20:13 -0800892
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 spin_unlock_irq(&conf->resync_lock);
894}
895
NeilBrowne879a872011-10-11 16:49:02 +1100896static void lower_barrier(struct r10conf *conf)
NeilBrown0a27ec92006-01-06 00:20:13 -0800897{
898 unsigned long flags;
899 spin_lock_irqsave(&conf->resync_lock, flags);
900 conf->barrier--;
901 spin_unlock_irqrestore(&conf->resync_lock, flags);
902 wake_up(&conf->wait_barrier);
903}
904
NeilBrowne879a872011-10-11 16:49:02 +1100905static void wait_barrier(struct r10conf *conf)
NeilBrown0a27ec92006-01-06 00:20:13 -0800906{
907 spin_lock_irq(&conf->resync_lock);
908 if (conf->barrier) {
909 conf->nr_waiting++;
NeilBrownd6b42dc2012-03-19 12:46:38 +1100910 /* Wait for the barrier to drop.
911 * However if there are already pending
912 * requests (preventing the barrier from
913 * rising completely), and the
914 * pre-process bio queue isn't empty,
915 * then don't wait, as we need to empty
916 * that queue to get the nr_pending
917 * count down.
918 */
919 wait_event_lock_irq(conf->wait_barrier,
920 !conf->barrier ||
921 (conf->nr_pending &&
922 current->bio_list &&
923 !bio_list_empty(current->bio_list)),
NeilBrown0a27ec92006-01-06 00:20:13 -0800924 conf->resync_lock,
NeilBrownd6b42dc2012-03-19 12:46:38 +1100925 );
NeilBrown0a27ec92006-01-06 00:20:13 -0800926 conf->nr_waiting--;
927 }
928 conf->nr_pending++;
929 spin_unlock_irq(&conf->resync_lock);
930}
931
NeilBrowne879a872011-10-11 16:49:02 +1100932static void allow_barrier(struct r10conf *conf)
NeilBrown0a27ec92006-01-06 00:20:13 -0800933{
934 unsigned long flags;
935 spin_lock_irqsave(&conf->resync_lock, flags);
936 conf->nr_pending--;
937 spin_unlock_irqrestore(&conf->resync_lock, flags);
938 wake_up(&conf->wait_barrier);
939}
940
NeilBrowne879a872011-10-11 16:49:02 +1100941static void freeze_array(struct r10conf *conf)
NeilBrown4443ae12006-01-06 00:20:28 -0800942{
943 /* stop syncio and normal IO and wait for everything to
NeilBrownf1885932006-01-06 00:20:42 -0800944 * go quiet.
NeilBrown4443ae12006-01-06 00:20:28 -0800945 * We increment barrier and nr_waiting, and then
NeilBrown1c830532008-03-04 14:29:35 -0800946 * wait until nr_pending match nr_queued+1
947 * This is called in the context of one normal IO request
948 * that has failed. Thus any sync request that might be pending
949 * will be blocked by nr_pending, and we need to wait for
950 * pending IO requests to complete or be queued for re-try.
951 * Thus the number queued (nr_queued) plus this request (1)
952 * must match the number of pending IOs (nr_pending) before
953 * we continue.
NeilBrown4443ae12006-01-06 00:20:28 -0800954 */
955 spin_lock_irq(&conf->resync_lock);
956 conf->barrier++;
957 conf->nr_waiting++;
958 wait_event_lock_irq(conf->wait_barrier,
NeilBrown1c830532008-03-04 14:29:35 -0800959 conf->nr_pending == conf->nr_queued+1,
NeilBrown4443ae12006-01-06 00:20:28 -0800960 conf->resync_lock,
NeilBrownc3b328a2011-04-18 18:25:43 +1000961 flush_pending_writes(conf));
962
NeilBrown4443ae12006-01-06 00:20:28 -0800963 spin_unlock_irq(&conf->resync_lock);
964}
965
NeilBrowne879a872011-10-11 16:49:02 +1100966static void unfreeze_array(struct r10conf *conf)
NeilBrown4443ae12006-01-06 00:20:28 -0800967{
968 /* reverse the effect of the freeze */
969 spin_lock_irq(&conf->resync_lock);
970 conf->barrier--;
971 conf->nr_waiting--;
972 wake_up(&conf->wait_barrier);
973 spin_unlock_irq(&conf->resync_lock);
974}
975
Linus Torvaldsb4fdcb02011-11-04 17:06:58 -0700976static void make_request(struct mddev *mddev, struct bio * bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977{
NeilBrowne879a872011-10-11 16:49:02 +1100978 struct r10conf *conf = mddev->private;
NeilBrown9f2c9d12011-10-11 16:48:43 +1100979 struct r10bio *r10_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 struct bio *read_bio;
981 int i;
982 int chunk_sects = conf->chunk_mask + 1;
Jens Axboea3623572005-11-01 09:26:16 +0100983 const int rw = bio_data_dir(bio);
NeilBrown2c7d46e2010-08-18 16:16:05 +1000984 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
Tejun Heoe9c74692010-09-03 11:56:18 +0200985 const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
NeilBrown6cce3b22006-01-06 00:20:16 -0800986 unsigned long flags;
NeilBrown3cb03002011-10-11 16:45:26 +1100987 struct md_rdev *blocked_rdev;
NeilBrownc3b328a2011-04-18 18:25:43 +1000988 int plugged;
NeilBrownd4432c22011-07-28 11:39:24 +1000989 int sectors_handled;
990 int max_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991
Tejun Heoe9c74692010-09-03 11:56:18 +0200992 if (unlikely(bio->bi_rw & REQ_FLUSH)) {
993 md_flush_request(mddev, bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200994 return;
NeilBrowne5dcdd82005-09-09 16:23:41 -0700995 }
996
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 /* If this request crosses a chunk boundary, we need to
998 * split it. This will only happen for 1 PAGE (or less) requests.
999 */
1000 if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
1001 > chunk_sects &&
1002 conf->near_copies < conf->raid_disks)) {
1003 struct bio_pair *bp;
1004 /* Sanity check -- queue functions should prevent this happening */
1005 if (bio->bi_vcnt != 1 ||
1006 bio->bi_idx != 0)
1007 goto bad_map;
1008 /* This is a one page bio that upper layers
1009 * refuse to split for us, so we need to split it.
1010 */
Denis ChengRq6feef532008-10-09 08:57:05 +02001011 bp = bio_split(bio,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
NeilBrown51e9ac72010-08-07 21:17:00 +10001013
1014 /* Each of these 'make_request' calls will call 'wait_barrier'.
1015 * If the first succeeds but the second blocks due to the resync
1016 * thread raising the barrier, we will deadlock because the
1017 * IO to the underlying device will be queued in generic_make_request
1018 * and will never complete, so will never reduce nr_pending.
1019 * So increment nr_waiting here so no new raise_barriers will
1020 * succeed, and so the second wait_barrier cannot block.
1021 */
1022 spin_lock_irq(&conf->resync_lock);
1023 conf->nr_waiting++;
1024 spin_unlock_irq(&conf->resync_lock);
1025
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +02001026 make_request(mddev, &bp->bio1);
1027 make_request(mddev, &bp->bio2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
NeilBrown51e9ac72010-08-07 21:17:00 +10001029 spin_lock_irq(&conf->resync_lock);
1030 conf->nr_waiting--;
1031 wake_up(&conf->wait_barrier);
1032 spin_unlock_irq(&conf->resync_lock);
1033
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 bio_pair_release(bp);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +02001035 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 bad_map:
NeilBrown128595e2010-05-03 14:47:14 +10001037 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
1038 " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
1040
NeilBrown6712ecf2007-09-27 12:47:43 +02001041 bio_io_error(bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +02001042 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 }
1044
NeilBrown3d310eb2005-06-21 17:17:26 -07001045 md_write_start(mddev, bio);
NeilBrown06d91a52005-06-21 17:17:12 -07001046
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 /*
1048 * Register the new request and wait if the reconstruction
1049 * thread has put up a bar for new requests.
1050 * Continue immediately if no resync is active currently.
1051 */
NeilBrown0a27ec92006-01-06 00:20:13 -08001052 wait_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1055
1056 r10_bio->master_bio = bio;
1057 r10_bio->sectors = bio->bi_size >> 9;
1058
1059 r10_bio->mddev = mddev;
1060 r10_bio->sector = bio->bi_sector;
NeilBrown6cce3b22006-01-06 00:20:16 -08001061 r10_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062
NeilBrown856e08e2011-07-28 11:39:23 +10001063 /* We might need to issue multiple reads to different
1064 * devices if there are bad blocks around, so we keep
1065 * track of the number of reads in bio->bi_phys_segments.
1066 * If this is 0, there is only one r10_bio and no locking
1067 * will be needed when the request completes. If it is
1068 * non-zero, then it is the number of not-completed requests.
1069 */
1070 bio->bi_phys_segments = 0;
1071 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
1072
Jens Axboea3623572005-11-01 09:26:16 +01001073 if (rw == READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 /*
1075 * read balancing logic:
1076 */
NeilBrown96c3fd12011-12-23 10:17:54 +11001077 struct md_rdev *rdev;
NeilBrown856e08e2011-07-28 11:39:23 +10001078 int slot;
1079
1080read_again:
NeilBrown96c3fd12011-12-23 10:17:54 +11001081 rdev = read_balance(conf, r10_bio, &max_sectors);
1082 if (!rdev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 raid_end_bio_io(r10_bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +02001084 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 }
NeilBrown96c3fd12011-12-23 10:17:54 +11001086 slot = r10_bio->read_slot;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087
NeilBrowna167f662010-10-26 18:31:13 +11001088 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
NeilBrown856e08e2011-07-28 11:39:23 +10001089 md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
1090 max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091
1092 r10_bio->devs[slot].bio = read_bio;
NeilBrownabbf0982011-12-23 10:17:54 +11001093 r10_bio->devs[slot].rdev = rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094
1095 read_bio->bi_sector = r10_bio->devs[slot].addr +
NeilBrown96c3fd12011-12-23 10:17:54 +11001096 rdev->data_offset;
1097 read_bio->bi_bdev = rdev->bdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 read_bio->bi_end_io = raid10_end_read_request;
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001099 read_bio->bi_rw = READ | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 read_bio->bi_private = r10_bio;
1101
NeilBrown856e08e2011-07-28 11:39:23 +10001102 if (max_sectors < r10_bio->sectors) {
1103 /* Could not read all from this device, so we will
1104 * need another r10_bio.
1105 */
NeilBrown856e08e2011-07-28 11:39:23 +10001106 sectors_handled = (r10_bio->sectors + max_sectors
1107 - bio->bi_sector);
1108 r10_bio->sectors = max_sectors;
1109 spin_lock_irq(&conf->device_lock);
1110 if (bio->bi_phys_segments == 0)
1111 bio->bi_phys_segments = 2;
1112 else
1113 bio->bi_phys_segments++;
1114 spin_unlock(&conf->device_lock);
1115 /* Cannot call generic_make_request directly
1116 * as that will be queued in __generic_make_request
1117 * and subsequent mempool_alloc might block
1118 * waiting for it. so hand bio over to raid10d.
1119 */
1120 reschedule_retry(r10_bio);
1121
1122 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1123
1124 r10_bio->master_bio = bio;
1125 r10_bio->sectors = ((bio->bi_size >> 9)
1126 - sectors_handled);
1127 r10_bio->state = 0;
1128 r10_bio->mddev = mddev;
1129 r10_bio->sector = bio->bi_sector + sectors_handled;
1130 goto read_again;
1131 } else
1132 generic_make_request(read_bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +02001133 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 }
1135
1136 /*
1137 * WRITE:
1138 */
NeilBrown34db0cd2011-10-11 16:50:01 +11001139 if (conf->pending_count >= max_queued_requests) {
1140 md_wakeup_thread(mddev->thread);
1141 wait_event(conf->wait_barrier,
1142 conf->pending_count < max_queued_requests);
1143 }
Dan Williams6bfe0b42008-04-30 00:52:32 -07001144 /* first select target devices under rcu_lock and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 * inc refcount on their rdev. Record them by setting
1146 * bios[x] to bio
NeilBrownd4432c22011-07-28 11:39:24 +10001147 * If there are known/acknowledged bad blocks on any device
1148 * on which we have seen a write error, we want to avoid
1149 * writing to those blocks. This potentially requires several
1150 * writes to write around the bad blocks. Each set of writes
1151 * gets its own r10_bio with a set of bios attached. The number
1152 * of r10_bios is recored in bio->bi_phys_segments just as with
1153 * the read case.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 */
NeilBrownc3b328a2011-04-18 18:25:43 +10001155 plugged = mddev_check_plugged(mddev);
1156
NeilBrown69335ef2011-12-23 10:17:54 +11001157 r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 raid10_find_phys(conf, r10_bio);
NeilBrownd4432c22011-07-28 11:39:24 +10001159retry_write:
Harvey Harrisoncb6969e2008-05-06 20:42:32 -07001160 blocked_rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 rcu_read_lock();
NeilBrownd4432c22011-07-28 11:39:24 +10001162 max_sectors = r10_bio->sectors;
1163
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 for (i = 0; i < conf->copies; i++) {
1165 int d = r10_bio->devs[i].devnum;
NeilBrown3cb03002011-10-11 16:45:26 +11001166 struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
NeilBrown475b0322011-12-23 10:17:55 +11001167 struct md_rdev *rrdev = rcu_dereference(
1168 conf->mirrors[d].replacement);
NeilBrown4ca40c22011-12-23 10:17:55 +11001169 if (rdev == rrdev)
1170 rrdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07001171 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1172 atomic_inc(&rdev->nr_pending);
1173 blocked_rdev = rdev;
1174 break;
1175 }
NeilBrown475b0322011-12-23 10:17:55 +11001176 if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
1177 atomic_inc(&rrdev->nr_pending);
1178 blocked_rdev = rrdev;
1179 break;
1180 }
NeilBrown050b6612012-03-19 12:46:39 +11001181 if (rrdev && (test_bit(Faulty, &rrdev->flags)
1182 || test_bit(Unmerged, &rrdev->flags)))
NeilBrown475b0322011-12-23 10:17:55 +11001183 rrdev = NULL;
1184
NeilBrownd4432c22011-07-28 11:39:24 +10001185 r10_bio->devs[i].bio = NULL;
NeilBrown475b0322011-12-23 10:17:55 +11001186 r10_bio->devs[i].repl_bio = NULL;
NeilBrown050b6612012-03-19 12:46:39 +11001187 if (!rdev || test_bit(Faulty, &rdev->flags) ||
1188 test_bit(Unmerged, &rdev->flags)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08001189 set_bit(R10BIO_Degraded, &r10_bio->state);
NeilBrownd4432c22011-07-28 11:39:24 +10001190 continue;
NeilBrown6cce3b22006-01-06 00:20:16 -08001191 }
NeilBrownd4432c22011-07-28 11:39:24 +10001192 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1193 sector_t first_bad;
1194 sector_t dev_sector = r10_bio->devs[i].addr;
1195 int bad_sectors;
1196 int is_bad;
1197
1198 is_bad = is_badblock(rdev, dev_sector,
1199 max_sectors,
1200 &first_bad, &bad_sectors);
1201 if (is_bad < 0) {
1202 /* Mustn't write here until the bad block
1203 * is acknowledged
1204 */
1205 atomic_inc(&rdev->nr_pending);
1206 set_bit(BlockedBadBlocks, &rdev->flags);
1207 blocked_rdev = rdev;
1208 break;
1209 }
1210 if (is_bad && first_bad <= dev_sector) {
1211 /* Cannot write here at all */
1212 bad_sectors -= (dev_sector - first_bad);
1213 if (bad_sectors < max_sectors)
1214 /* Mustn't write more than bad_sectors
1215 * to other devices yet
1216 */
1217 max_sectors = bad_sectors;
1218 /* We don't set R10BIO_Degraded as that
1219 * only applies if the disk is missing,
1220 * so it might be re-added, and we want to
1221 * know to recover this chunk.
1222 * In this case the device is here, and the
1223 * fact that this chunk is not in-sync is
1224 * recorded in the bad block log.
1225 */
1226 continue;
1227 }
1228 if (is_bad) {
1229 int good_sectors = first_bad - dev_sector;
1230 if (good_sectors < max_sectors)
1231 max_sectors = good_sectors;
1232 }
1233 }
1234 r10_bio->devs[i].bio = bio;
1235 atomic_inc(&rdev->nr_pending);
NeilBrown475b0322011-12-23 10:17:55 +11001236 if (rrdev) {
1237 r10_bio->devs[i].repl_bio = bio;
1238 atomic_inc(&rrdev->nr_pending);
1239 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 }
1241 rcu_read_unlock();
1242
Dan Williams6bfe0b42008-04-30 00:52:32 -07001243 if (unlikely(blocked_rdev)) {
1244 /* Have to wait for this device to get unblocked, then retry */
1245 int j;
1246 int d;
1247
NeilBrown475b0322011-12-23 10:17:55 +11001248 for (j = 0; j < i; j++) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07001249 if (r10_bio->devs[j].bio) {
1250 d = r10_bio->devs[j].devnum;
1251 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1252 }
NeilBrown475b0322011-12-23 10:17:55 +11001253 if (r10_bio->devs[j].repl_bio) {
NeilBrown4ca40c22011-12-23 10:17:55 +11001254 struct md_rdev *rdev;
NeilBrown475b0322011-12-23 10:17:55 +11001255 d = r10_bio->devs[j].devnum;
NeilBrown4ca40c22011-12-23 10:17:55 +11001256 rdev = conf->mirrors[d].replacement;
1257 if (!rdev) {
1258 /* Race with remove_disk */
1259 smp_mb();
1260 rdev = conf->mirrors[d].rdev;
1261 }
1262 rdev_dec_pending(rdev, mddev);
NeilBrown475b0322011-12-23 10:17:55 +11001263 }
1264 }
Dan Williams6bfe0b42008-04-30 00:52:32 -07001265 allow_barrier(conf);
1266 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1267 wait_barrier(conf);
1268 goto retry_write;
1269 }
1270
NeilBrownd4432c22011-07-28 11:39:24 +10001271 if (max_sectors < r10_bio->sectors) {
1272 /* We are splitting this into multiple parts, so
1273 * we need to prepare for allocating another r10_bio.
1274 */
1275 r10_bio->sectors = max_sectors;
1276 spin_lock_irq(&conf->device_lock);
1277 if (bio->bi_phys_segments == 0)
1278 bio->bi_phys_segments = 2;
1279 else
1280 bio->bi_phys_segments++;
1281 spin_unlock_irq(&conf->device_lock);
1282 }
1283 sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
1284
NeilBrown4e780642010-10-19 12:54:01 +11001285 atomic_set(&r10_bio->remaining, 1);
NeilBrownd4432c22011-07-28 11:39:24 +10001286 bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
NeilBrown06d91a52005-06-21 17:17:12 -07001287
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 for (i = 0; i < conf->copies; i++) {
1289 struct bio *mbio;
1290 int d = r10_bio->devs[i].devnum;
1291 if (!r10_bio->devs[i].bio)
1292 continue;
1293
NeilBrowna167f662010-10-26 18:31:13 +11001294 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
NeilBrownd4432c22011-07-28 11:39:24 +10001295 md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
1296 max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 r10_bio->devs[i].bio = mbio;
1298
NeilBrownd4432c22011-07-28 11:39:24 +10001299 mbio->bi_sector = (r10_bio->devs[i].addr+
1300 conf->mirrors[d].rdev->data_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1302 mbio->bi_end_io = raid10_end_write_request;
Tejun Heoe9c74692010-09-03 11:56:18 +02001303 mbio->bi_rw = WRITE | do_sync | do_fua;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 mbio->bi_private = r10_bio;
1305
1306 atomic_inc(&r10_bio->remaining);
NeilBrown4e780642010-10-19 12:54:01 +11001307 spin_lock_irqsave(&conf->device_lock, flags);
1308 bio_list_add(&conf->pending_bio_list, mbio);
NeilBrown34db0cd2011-10-11 16:50:01 +11001309 conf->pending_count++;
NeilBrown4e780642010-10-19 12:54:01 +11001310 spin_unlock_irqrestore(&conf->device_lock, flags);
NeilBrown475b0322011-12-23 10:17:55 +11001311
1312 if (!r10_bio->devs[i].repl_bio)
1313 continue;
1314
1315 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1316 md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
1317 max_sectors);
1318 r10_bio->devs[i].repl_bio = mbio;
1319
NeilBrown4ca40c22011-12-23 10:17:55 +11001320 /* We are actively writing to the original device
1321 * so it cannot disappear, so the replacement cannot
1322 * become NULL here
1323 */
NeilBrown475b0322011-12-23 10:17:55 +11001324 mbio->bi_sector = (r10_bio->devs[i].addr+
1325 conf->mirrors[d].replacement->data_offset);
1326 mbio->bi_bdev = conf->mirrors[d].replacement->bdev;
1327 mbio->bi_end_io = raid10_end_write_request;
1328 mbio->bi_rw = WRITE | do_sync | do_fua;
1329 mbio->bi_private = r10_bio;
1330
1331 atomic_inc(&r10_bio->remaining);
1332 spin_lock_irqsave(&conf->device_lock, flags);
1333 bio_list_add(&conf->pending_bio_list, mbio);
1334 conf->pending_count++;
1335 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 }
1337
NeilBrown079fa162011-09-10 17:21:23 +10001338 /* Don't remove the bias on 'remaining' (one_write_done) until
1339 * after checking if we need to go around again.
1340 */
NeilBrowna35e63e2008-03-04 14:29:29 -08001341
NeilBrownd4432c22011-07-28 11:39:24 +10001342 if (sectors_handled < (bio->bi_size >> 9)) {
NeilBrown079fa162011-09-10 17:21:23 +10001343 one_write_done(r10_bio);
NeilBrown5e570282011-07-28 11:39:25 +10001344 /* We need another r10_bio. It has already been counted
NeilBrownd4432c22011-07-28 11:39:24 +10001345 * in bio->bi_phys_segments.
1346 */
1347 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1348
1349 r10_bio->master_bio = bio;
1350 r10_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1351
1352 r10_bio->mddev = mddev;
1353 r10_bio->sector = bio->bi_sector + sectors_handled;
1354 r10_bio->state = 0;
1355 goto retry_write;
1356 }
NeilBrown079fa162011-09-10 17:21:23 +10001357 one_write_done(r10_bio);
1358
1359 /* In case raid10d snuck in to freeze_array */
1360 wake_up(&conf->wait_barrier);
NeilBrownd4432c22011-07-28 11:39:24 +10001361
NeilBrownc3b328a2011-04-18 18:25:43 +10001362 if (do_sync || !mddev->bitmap || !plugged)
Lars Ellenberge3881a62007-01-10 23:15:37 -08001363 md_wakeup_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364}
1365
NeilBrownfd01b882011-10-11 16:47:53 +11001366static void status(struct seq_file *seq, struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367{
NeilBrowne879a872011-10-11 16:49:02 +11001368 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 int i;
1370
1371 if (conf->near_copies < conf->raid_disks)
Andre Noll9d8f0362009-06-18 08:45:01 +10001372 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 if (conf->near_copies > 1)
1374 seq_printf(seq, " %d near-copies", conf->near_copies);
NeilBrownc93983b2006-06-26 00:27:41 -07001375 if (conf->far_copies > 1) {
1376 if (conf->far_offset)
1377 seq_printf(seq, " %d offset-copies", conf->far_copies);
1378 else
1379 seq_printf(seq, " %d far-copies", conf->far_copies);
1380 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
NeilBrown76186dd2006-10-03 01:15:48 -07001382 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 for (i = 0; i < conf->raid_disks; i++)
1384 seq_printf(seq, "%s",
1385 conf->mirrors[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08001386 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 seq_printf(seq, "]");
1388}
1389
NeilBrown700c7212011-07-27 11:00:36 +10001390/* check if there are enough drives for
1391 * every block to appear on atleast one.
1392 * Don't consider the device numbered 'ignore'
1393 * as we might be about to remove it.
1394 */
NeilBrowne879a872011-10-11 16:49:02 +11001395static int enough(struct r10conf *conf, int ignore)
NeilBrown700c7212011-07-27 11:00:36 +10001396{
1397 int first = 0;
1398
1399 do {
1400 int n = conf->copies;
1401 int cnt = 0;
1402 while (n--) {
1403 if (conf->mirrors[first].rdev &&
1404 first != ignore)
1405 cnt++;
1406 first = (first+1) % conf->raid_disks;
1407 }
1408 if (cnt == 0)
1409 return 0;
1410 } while (first != 0);
1411 return 1;
1412}
1413
NeilBrownfd01b882011-10-11 16:47:53 +11001414static void error(struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415{
1416 char b[BDEVNAME_SIZE];
NeilBrowne879a872011-10-11 16:49:02 +11001417 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418
1419 /*
1420 * If it is not operational, then we have already marked it as dead
1421 * else if it is the last working disks, ignore the error, let the
1422 * next level up know.
1423 * else mark the drive as failed
1424 */
NeilBrownb2d444d2005-11-08 21:39:31 -08001425 if (test_bit(In_sync, &rdev->flags)
NeilBrown700c7212011-07-27 11:00:36 +10001426 && !enough(conf, rdev->raid_disk))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 /*
1428 * Don't fail the drive, just return an IO error.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 */
1430 return;
NeilBrownc04be0a2006-10-03 01:15:53 -07001431 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1432 unsigned long flags;
1433 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001435 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 /*
1437 * if recovery is running, make sure it aborts.
1438 */
NeilBrowndfc70642008-05-23 13:04:39 -07001439 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 }
NeilBrownde393cd2011-07-28 11:31:48 +10001441 set_bit(Blocked, &rdev->flags);
NeilBrownb2d444d2005-11-08 21:39:31 -08001442 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -07001443 set_bit(MD_CHANGE_DEVS, &mddev->flags);
Joe Perches067032b2011-01-14 09:14:33 +11001444 printk(KERN_ALERT
1445 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1446 "md/raid10:%s: Operation continuing on %d devices.\n",
NeilBrown128595e2010-05-03 14:47:14 +10001447 mdname(mddev), bdevname(rdev->bdev, b),
1448 mdname(mddev), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449}
1450
NeilBrowne879a872011-10-11 16:49:02 +11001451static void print_conf(struct r10conf *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452{
1453 int i;
NeilBrown0f6d02d2011-10-11 16:48:46 +11001454 struct mirror_info *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455
NeilBrown128595e2010-05-03 14:47:14 +10001456 printk(KERN_DEBUG "RAID10 conf printout:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 if (!conf) {
NeilBrown128595e2010-05-03 14:47:14 +10001458 printk(KERN_DEBUG "(!conf)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 return;
1460 }
NeilBrown128595e2010-05-03 14:47:14 +10001461 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 conf->raid_disks);
1463
1464 for (i = 0; i < conf->raid_disks; i++) {
1465 char b[BDEVNAME_SIZE];
1466 tmp = conf->mirrors + i;
1467 if (tmp->rdev)
NeilBrown128595e2010-05-03 14:47:14 +10001468 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08001469 i, !test_bit(In_sync, &tmp->rdev->flags),
1470 !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 bdevname(tmp->rdev->bdev,b));
1472 }
1473}
1474
NeilBrowne879a872011-10-11 16:49:02 +11001475static void close_sync(struct r10conf *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476{
NeilBrown0a27ec92006-01-06 00:20:13 -08001477 wait_barrier(conf);
1478 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479
1480 mempool_destroy(conf->r10buf_pool);
1481 conf->r10buf_pool = NULL;
1482}
1483
NeilBrownfd01b882011-10-11 16:47:53 +11001484static int raid10_spare_active(struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485{
1486 int i;
NeilBrowne879a872011-10-11 16:49:02 +11001487 struct r10conf *conf = mddev->private;
NeilBrown0f6d02d2011-10-11 16:48:46 +11001488 struct mirror_info *tmp;
NeilBrown6b965622010-08-18 11:56:59 +10001489 int count = 0;
1490 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491
1492 /*
1493 * Find all non-in_sync disks within the RAID10 configuration
1494 * and mark them in_sync
1495 */
1496 for (i = 0; i < conf->raid_disks; i++) {
1497 tmp = conf->mirrors + i;
NeilBrown4ca40c22011-12-23 10:17:55 +11001498 if (tmp->replacement
1499 && tmp->replacement->recovery_offset == MaxSector
1500 && !test_bit(Faulty, &tmp->replacement->flags)
1501 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
1502 /* Replacement has just become active */
1503 if (!tmp->rdev
1504 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
1505 count++;
1506 if (tmp->rdev) {
1507 /* Replaced device not technically faulty,
1508 * but we need to be sure it gets removed
1509 * and never re-added.
1510 */
1511 set_bit(Faulty, &tmp->rdev->flags);
1512 sysfs_notify_dirent_safe(
1513 tmp->rdev->sysfs_state);
1514 }
1515 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
1516 } else if (tmp->rdev
1517 && !test_bit(Faulty, &tmp->rdev->flags)
1518 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
NeilBrown6b965622010-08-18 11:56:59 +10001519 count++;
Adrian Drzewieckie6ffbcb2010-08-18 11:49:02 +10001520 sysfs_notify_dirent(tmp->rdev->sysfs_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001521 }
1522 }
NeilBrown6b965622010-08-18 11:56:59 +10001523 spin_lock_irqsave(&conf->device_lock, flags);
1524 mddev->degraded -= count;
1525 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526
1527 print_conf(conf);
NeilBrown6b965622010-08-18 11:56:59 +10001528 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529}
1530
1531
NeilBrownfd01b882011-10-11 16:47:53 +11001532static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533{
NeilBrowne879a872011-10-11 16:49:02 +11001534 struct r10conf *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10001535 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 int mirror;
Neil Brown6c2fce22008-06-28 08:31:31 +10001537 int first = 0;
NeilBrown84707f32010-03-16 17:23:35 +11001538 int last = conf->raid_disks - 1;
NeilBrown050b6612012-03-19 12:46:39 +11001539 struct request_queue *q = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540
1541 if (mddev->recovery_cp < MaxSector)
1542 /* only hot-add to in-sync arrays, as recovery is
1543 * very different from resync
1544 */
Neil Brown199050e2008-06-28 08:31:33 +10001545 return -EBUSY;
NeilBrowndc10c642012-03-19 12:46:37 +11001546 if (rdev->saved_raid_disk < 0 && !enough(conf, -1))
Neil Brown199050e2008-06-28 08:31:33 +10001547 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548
NeilBrowna53a6c82008-11-06 17:28:20 +11001549 if (rdev->raid_disk >= 0)
Neil Brown6c2fce22008-06-28 08:31:31 +10001550 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551
NeilBrown050b6612012-03-19 12:46:39 +11001552 if (q->merge_bvec_fn) {
1553 set_bit(Unmerged, &rdev->flags);
1554 mddev->merge_check_needed = 1;
1555 }
1556
Namhyung Kim2c4193d2011-07-18 17:38:43 +10001557 if (rdev->saved_raid_disk >= first &&
NeilBrown6cce3b22006-01-06 00:20:16 -08001558 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1559 mirror = rdev->saved_raid_disk;
1560 else
Neil Brown6c2fce22008-06-28 08:31:31 +10001561 mirror = first;
NeilBrown2bb77732011-07-27 11:00:36 +10001562 for ( ; mirror <= last ; mirror++) {
NeilBrown0f6d02d2011-10-11 16:48:46 +11001563 struct mirror_info *p = &conf->mirrors[mirror];
NeilBrown2bb77732011-07-27 11:00:36 +10001564 if (p->recovery_disabled == mddev->recovery_disabled)
1565 continue;
NeilBrownb7044d42011-12-23 10:17:56 +11001566 if (p->rdev) {
1567 if (!test_bit(WantReplacement, &p->rdev->flags) ||
1568 p->replacement != NULL)
1569 continue;
1570 clear_bit(In_sync, &rdev->flags);
1571 set_bit(Replacement, &rdev->flags);
1572 rdev->raid_disk = mirror;
1573 err = 0;
1574 disk_stack_limits(mddev->gendisk, rdev->bdev,
1575 rdev->data_offset << 9);
NeilBrownb7044d42011-12-23 10:17:56 +11001576 conf->fullsync = 1;
1577 rcu_assign_pointer(p->replacement, rdev);
1578 break;
1579 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580
NeilBrown2bb77732011-07-27 11:00:36 +10001581 disk_stack_limits(mddev->gendisk, rdev->bdev,
1582 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583
NeilBrown2bb77732011-07-27 11:00:36 +10001584 p->head_position = 0;
NeilBrownd890fa22011-10-26 11:54:39 +11001585 p->recovery_disabled = mddev->recovery_disabled - 1;
NeilBrown2bb77732011-07-27 11:00:36 +10001586 rdev->raid_disk = mirror;
1587 err = 0;
1588 if (rdev->saved_raid_disk != mirror)
1589 conf->fullsync = 1;
1590 rcu_assign_pointer(p->rdev, rdev);
1591 break;
1592 }
NeilBrown050b6612012-03-19 12:46:39 +11001593 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1594 /* Some requests might not have seen this new
1595 * merge_bvec_fn. We must wait for them to complete
1596 * before merging the device fully.
1597 * First we make sure any code which has tested
1598 * our function has submitted the request, then
1599 * we wait for all outstanding requests to complete.
1600 */
1601 synchronize_sched();
1602 raise_barrier(conf, 0);
1603 lower_barrier(conf);
1604 clear_bit(Unmerged, &rdev->flags);
1605 }
Andre Nollac5e7112009-08-03 10:59:47 +10001606 md_integrity_add_rdev(rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 print_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10001608 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609}
1610
NeilBrownb8321b62011-12-23 10:17:51 +11001611static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612{
NeilBrowne879a872011-10-11 16:49:02 +11001613 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 int err = 0;
NeilBrownb8321b62011-12-23 10:17:51 +11001615 int number = rdev->raid_disk;
NeilBrownc8ab9032011-12-23 10:17:54 +11001616 struct md_rdev **rdevp;
1617 struct mirror_info *p = conf->mirrors + number;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618
1619 print_conf(conf);
NeilBrownc8ab9032011-12-23 10:17:54 +11001620 if (rdev == p->rdev)
1621 rdevp = &p->rdev;
1622 else if (rdev == p->replacement)
1623 rdevp = &p->replacement;
1624 else
1625 return 0;
1626
1627 if (test_bit(In_sync, &rdev->flags) ||
1628 atomic_read(&rdev->nr_pending)) {
1629 err = -EBUSY;
1630 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 }
NeilBrownc8ab9032011-12-23 10:17:54 +11001632 /* Only remove faulty devices if recovery
1633 * is not possible.
1634 */
1635 if (!test_bit(Faulty, &rdev->flags) &&
1636 mddev->recovery_disabled != p->recovery_disabled &&
NeilBrown4ca40c22011-12-23 10:17:55 +11001637 (!p->replacement || p->replacement == rdev) &&
NeilBrownc8ab9032011-12-23 10:17:54 +11001638 enough(conf, -1)) {
1639 err = -EBUSY;
1640 goto abort;
1641 }
1642 *rdevp = NULL;
1643 synchronize_rcu();
1644 if (atomic_read(&rdev->nr_pending)) {
1645 /* lost the race, try later */
1646 err = -EBUSY;
1647 *rdevp = rdev;
1648 goto abort;
NeilBrown4ca40c22011-12-23 10:17:55 +11001649 } else if (p->replacement) {
1650 /* We must have just cleared 'rdev' */
1651 p->rdev = p->replacement;
1652 clear_bit(Replacement, &p->replacement->flags);
1653 smp_mb(); /* Make sure other CPUs may see both as identical
1654 * but will never see neither -- if they are careful.
1655 */
1656 p->replacement = NULL;
1657 clear_bit(WantReplacement, &rdev->flags);
1658 } else
1659 /* We might have just remove the Replacement as faulty
1660 * Clear the flag just in case
1661 */
1662 clear_bit(WantReplacement, &rdev->flags);
1663
NeilBrownc8ab9032011-12-23 10:17:54 +11001664 err = md_integrity_register(mddev);
1665
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666abort:
1667
1668 print_conf(conf);
1669 return err;
1670}
1671
1672
NeilBrown6712ecf2007-09-27 12:47:43 +02001673static void end_sync_read(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674{
NeilBrown9f2c9d12011-10-11 16:48:43 +11001675 struct r10bio *r10_bio = bio->bi_private;
NeilBrowne879a872011-10-11 16:49:02 +11001676 struct r10conf *conf = r10_bio->mddev->private;
Namhyung Kim778ca012011-07-18 17:38:47 +10001677 int d;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678
NeilBrown69335ef2011-12-23 10:17:54 +11001679 d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
NeilBrown0eb3ff12006-01-06 00:20:29 -08001680
1681 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1682 set_bit(R10BIO_Uptodate, &r10_bio->state);
NeilBrowne684e412011-07-28 11:39:25 +10001683 else
1684 /* The write handler will notice the lack of
1685 * R10BIO_Uptodate and record any errors etc
1686 */
NeilBrown4dbcdc72006-01-06 00:20:52 -08001687 atomic_add(r10_bio->sectors,
1688 &conf->mirrors[d].rdev->corrected_errors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689
1690 /* for reconstruct, we always reschedule after a read.
1691 * for resync, only after all reads
1692 */
NeilBrown73d5c382009-02-25 13:18:47 +11001693 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1695 atomic_dec_and_test(&r10_bio->remaining)) {
1696 /* we have read all the blocks,
1697 * do the comparison in process context in raid10d
1698 */
1699 reschedule_retry(r10_bio);
1700 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701}
1702
NeilBrown9f2c9d12011-10-11 16:48:43 +11001703static void end_sync_request(struct r10bio *r10_bio)
NeilBrown5e570282011-07-28 11:39:25 +10001704{
NeilBrownfd01b882011-10-11 16:47:53 +11001705 struct mddev *mddev = r10_bio->mddev;
NeilBrown5e570282011-07-28 11:39:25 +10001706
1707 while (atomic_dec_and_test(&r10_bio->remaining)) {
1708 if (r10_bio->master_bio == NULL) {
1709 /* the primary of several recovery bios */
1710 sector_t s = r10_bio->sectors;
1711 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1712 test_bit(R10BIO_WriteError, &r10_bio->state))
1713 reschedule_retry(r10_bio);
1714 else
1715 put_buf(r10_bio);
1716 md_done_sync(mddev, s, 1);
1717 break;
1718 } else {
NeilBrown9f2c9d12011-10-11 16:48:43 +11001719 struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
NeilBrown5e570282011-07-28 11:39:25 +10001720 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1721 test_bit(R10BIO_WriteError, &r10_bio->state))
1722 reschedule_retry(r10_bio);
1723 else
1724 put_buf(r10_bio);
1725 r10_bio = r10_bio2;
1726 }
1727 }
1728}
1729
NeilBrown6712ecf2007-09-27 12:47:43 +02001730static void end_sync_write(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731{
1732 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
NeilBrown9f2c9d12011-10-11 16:48:43 +11001733 struct r10bio *r10_bio = bio->bi_private;
NeilBrownfd01b882011-10-11 16:47:53 +11001734 struct mddev *mddev = r10_bio->mddev;
NeilBrowne879a872011-10-11 16:49:02 +11001735 struct r10conf *conf = mddev->private;
Namhyung Kim778ca012011-07-18 17:38:47 +10001736 int d;
NeilBrown749c55e2011-07-28 11:39:24 +10001737 sector_t first_bad;
1738 int bad_sectors;
1739 int slot;
NeilBrown9ad1aef2011-12-23 10:17:55 +11001740 int repl;
NeilBrown4ca40c22011-12-23 10:17:55 +11001741 struct md_rdev *rdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742
NeilBrown9ad1aef2011-12-23 10:17:55 +11001743 d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
1744 if (repl)
1745 rdev = conf->mirrors[d].replacement;
NeilBrown547414d2012-03-13 11:21:20 +11001746 else
NeilBrown9ad1aef2011-12-23 10:17:55 +11001747 rdev = conf->mirrors[d].rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001748
NeilBrown1a0b7cd2011-07-28 11:39:25 +10001749 if (!uptodate) {
NeilBrown9ad1aef2011-12-23 10:17:55 +11001750 if (repl)
1751 md_error(mddev, rdev);
1752 else {
1753 set_bit(WriteErrorSeen, &rdev->flags);
NeilBrownb7044d42011-12-23 10:17:56 +11001754 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1755 set_bit(MD_RECOVERY_NEEDED,
1756 &rdev->mddev->recovery);
NeilBrown9ad1aef2011-12-23 10:17:55 +11001757 set_bit(R10BIO_WriteError, &r10_bio->state);
1758 }
1759 } else if (is_badblock(rdev,
NeilBrown749c55e2011-07-28 11:39:24 +10001760 r10_bio->devs[slot].addr,
1761 r10_bio->sectors,
1762 &first_bad, &bad_sectors))
1763 set_bit(R10BIO_MadeGood, &r10_bio->state);
NeilBrowndfc70642008-05-23 13:04:39 -07001764
NeilBrown9ad1aef2011-12-23 10:17:55 +11001765 rdev_dec_pending(rdev, mddev);
NeilBrown5e570282011-07-28 11:39:25 +10001766
1767 end_sync_request(r10_bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768}
1769
1770/*
1771 * Note: sync and recover and handled very differently for raid10
1772 * This code is for resync.
1773 * For resync, we read through virtual addresses and read all blocks.
1774 * If there is any error, we schedule a write. The lowest numbered
1775 * drive is authoritative.
1776 * However requests come for physical address, so we need to map.
1777 * For every physical address there are raid_disks/copies virtual addresses,
1778 * which is always are least one, but is not necessarly an integer.
1779 * This means that a physical address can span multiple chunks, so we may
1780 * have to submit multiple io requests for a single sync request.
1781 */
1782/*
1783 * We check if all blocks are in-sync and only write to blocks that
1784 * aren't in sync
1785 */
NeilBrown9f2c9d12011-10-11 16:48:43 +11001786static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787{
NeilBrowne879a872011-10-11 16:49:02 +11001788 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 int i, first;
1790 struct bio *tbio, *fbio;
1791
1792 atomic_set(&r10_bio->remaining, 1);
1793
1794 /* find the first device with a block */
1795 for (i=0; i<conf->copies; i++)
1796 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
1797 break;
1798
1799 if (i == conf->copies)
1800 goto done;
1801
1802 first = i;
1803 fbio = r10_bio->devs[i].bio;
1804
1805 /* now find blocks with errors */
NeilBrown0eb3ff12006-01-06 00:20:29 -08001806 for (i=0 ; i < conf->copies ; i++) {
1807 int j, d;
1808 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001809
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810 tbio = r10_bio->devs[i].bio;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001811
1812 if (tbio->bi_end_io != end_sync_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001813 continue;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001814 if (i == first)
1815 continue;
1816 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
1817 /* We know that the bi_io_vec layout is the same for
1818 * both 'first' and 'i', so we just compare them.
1819 * All vec entries are PAGE_SIZE;
1820 */
1821 for (j = 0; j < vcnt; j++)
1822 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
1823 page_address(tbio->bi_io_vec[j].bv_page),
1824 PAGE_SIZE))
1825 break;
1826 if (j == vcnt)
1827 continue;
1828 mddev->resync_mismatches += r10_bio->sectors;
NeilBrownf84ee362011-07-28 11:39:25 +10001829 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1830 /* Don't fix anything. */
1831 continue;
NeilBrown0eb3ff12006-01-06 00:20:29 -08001832 }
NeilBrownf84ee362011-07-28 11:39:25 +10001833 /* Ok, we need to write this bio, either to correct an
1834 * inconsistency or to correct an unreadable block.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835 * First we need to fixup bv_offset, bv_len and
1836 * bi_vecs, as the read request might have corrupted these
1837 */
1838 tbio->bi_vcnt = vcnt;
1839 tbio->bi_size = r10_bio->sectors << 9;
1840 tbio->bi_idx = 0;
1841 tbio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1843 tbio->bi_flags |= 1 << BIO_UPTODATE;
1844 tbio->bi_next = NULL;
1845 tbio->bi_rw = WRITE;
1846 tbio->bi_private = r10_bio;
1847 tbio->bi_sector = r10_bio->devs[i].addr;
1848
1849 for (j=0; j < vcnt ; j++) {
1850 tbio->bi_io_vec[j].bv_offset = 0;
1851 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
1852
1853 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1854 page_address(fbio->bi_io_vec[j].bv_page),
1855 PAGE_SIZE);
1856 }
1857 tbio->bi_end_io = end_sync_write;
1858
1859 d = r10_bio->devs[i].devnum;
1860 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1861 atomic_inc(&r10_bio->remaining);
1862 md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
1863
1864 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
1865 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1866 generic_make_request(tbio);
1867 }
1868
NeilBrown9ad1aef2011-12-23 10:17:55 +11001869 /* Now write out to any replacement devices
1870 * that are active
1871 */
1872 for (i = 0; i < conf->copies; i++) {
1873 int j, d;
1874 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
1875
1876 tbio = r10_bio->devs[i].repl_bio;
1877 if (!tbio || !tbio->bi_end_io)
1878 continue;
1879 if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
1880 && r10_bio->devs[i].bio != fbio)
1881 for (j = 0; j < vcnt; j++)
1882 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1883 page_address(fbio->bi_io_vec[j].bv_page),
1884 PAGE_SIZE);
1885 d = r10_bio->devs[i].devnum;
1886 atomic_inc(&r10_bio->remaining);
1887 md_sync_acct(conf->mirrors[d].replacement->bdev,
1888 tbio->bi_size >> 9);
1889 generic_make_request(tbio);
1890 }
1891
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892done:
1893 if (atomic_dec_and_test(&r10_bio->remaining)) {
1894 md_done_sync(mddev, r10_bio->sectors, 1);
1895 put_buf(r10_bio);
1896 }
1897}
1898
1899/*
1900 * Now for the recovery code.
1901 * Recovery happens across physical sectors.
1902 * We recover all non-is_sync drives by finding the virtual address of
1903 * each, and then choose a working drive that also has that virt address.
1904 * There is a separate r10_bio for each non-in_sync drive.
1905 * Only the first two slots are in use. The first for reading,
1906 * The second for writing.
1907 *
1908 */
NeilBrown9f2c9d12011-10-11 16:48:43 +11001909static void fix_recovery_read_error(struct r10bio *r10_bio)
NeilBrown5e570282011-07-28 11:39:25 +10001910{
1911 /* We got a read error during recovery.
1912 * We repeat the read in smaller page-sized sections.
1913 * If a read succeeds, write it to the new device or record
1914 * a bad block if we cannot.
1915 * If a read fails, record a bad block on both old and
1916 * new devices.
1917 */
NeilBrownfd01b882011-10-11 16:47:53 +11001918 struct mddev *mddev = r10_bio->mddev;
NeilBrowne879a872011-10-11 16:49:02 +11001919 struct r10conf *conf = mddev->private;
NeilBrown5e570282011-07-28 11:39:25 +10001920 struct bio *bio = r10_bio->devs[0].bio;
1921 sector_t sect = 0;
1922 int sectors = r10_bio->sectors;
1923 int idx = 0;
1924 int dr = r10_bio->devs[0].devnum;
1925 int dw = r10_bio->devs[1].devnum;
1926
1927 while (sectors) {
1928 int s = sectors;
NeilBrown3cb03002011-10-11 16:45:26 +11001929 struct md_rdev *rdev;
NeilBrown5e570282011-07-28 11:39:25 +10001930 sector_t addr;
1931 int ok;
1932
1933 if (s > (PAGE_SIZE>>9))
1934 s = PAGE_SIZE >> 9;
1935
1936 rdev = conf->mirrors[dr].rdev;
1937 addr = r10_bio->devs[0].addr + sect,
1938 ok = sync_page_io(rdev,
1939 addr,
1940 s << 9,
1941 bio->bi_io_vec[idx].bv_page,
1942 READ, false);
1943 if (ok) {
1944 rdev = conf->mirrors[dw].rdev;
1945 addr = r10_bio->devs[1].addr + sect;
1946 ok = sync_page_io(rdev,
1947 addr,
1948 s << 9,
1949 bio->bi_io_vec[idx].bv_page,
1950 WRITE, false);
NeilBrownb7044d42011-12-23 10:17:56 +11001951 if (!ok) {
NeilBrown5e570282011-07-28 11:39:25 +10001952 set_bit(WriteErrorSeen, &rdev->flags);
NeilBrownb7044d42011-12-23 10:17:56 +11001953 if (!test_and_set_bit(WantReplacement,
1954 &rdev->flags))
1955 set_bit(MD_RECOVERY_NEEDED,
1956 &rdev->mddev->recovery);
1957 }
NeilBrown5e570282011-07-28 11:39:25 +10001958 }
1959 if (!ok) {
1960 /* We don't worry if we cannot set a bad block -
1961 * it really is bad so there is no loss in not
1962 * recording it yet
1963 */
1964 rdev_set_badblocks(rdev, addr, s, 0);
1965
1966 if (rdev != conf->mirrors[dw].rdev) {
1967 /* need bad block on destination too */
NeilBrown3cb03002011-10-11 16:45:26 +11001968 struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
NeilBrown5e570282011-07-28 11:39:25 +10001969 addr = r10_bio->devs[1].addr + sect;
1970 ok = rdev_set_badblocks(rdev2, addr, s, 0);
1971 if (!ok) {
1972 /* just abort the recovery */
1973 printk(KERN_NOTICE
1974 "md/raid10:%s: recovery aborted"
1975 " due to read error\n",
1976 mdname(mddev));
1977
1978 conf->mirrors[dw].recovery_disabled
1979 = mddev->recovery_disabled;
1980 set_bit(MD_RECOVERY_INTR,
1981 &mddev->recovery);
1982 break;
1983 }
1984 }
1985 }
1986
1987 sectors -= s;
1988 sect += s;
1989 idx++;
1990 }
1991}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992
NeilBrown9f2c9d12011-10-11 16:48:43 +11001993static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994{
NeilBrowne879a872011-10-11 16:49:02 +11001995 struct r10conf *conf = mddev->private;
Namhyung Kimc65060a2011-07-18 17:38:49 +10001996 int d;
NeilBrown24afd802011-12-23 10:17:55 +11001997 struct bio *wbio, *wbio2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998
NeilBrown5e570282011-07-28 11:39:25 +10001999 if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
2000 fix_recovery_read_error(r10_bio);
2001 end_sync_request(r10_bio);
2002 return;
2003 }
2004
Namhyung Kimc65060a2011-07-18 17:38:49 +10002005 /*
2006 * share the pages with the first bio
Linus Torvalds1da177e2005-04-16 15:20:36 -07002007 * and submit the write request
2008 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002009 d = r10_bio->devs[1].devnum;
NeilBrown24afd802011-12-23 10:17:55 +11002010 wbio = r10_bio->devs[1].bio;
2011 wbio2 = r10_bio->devs[1].repl_bio;
2012 if (wbio->bi_end_io) {
2013 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2014 md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
2015 generic_make_request(wbio);
2016 }
2017 if (wbio2 && wbio2->bi_end_io) {
2018 atomic_inc(&conf->mirrors[d].replacement->nr_pending);
2019 md_sync_acct(conf->mirrors[d].replacement->bdev,
2020 wbio2->bi_size >> 9);
2021 generic_make_request(wbio2);
2022 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023}
2024
2025
2026/*
Robert Becker1e509152009-12-14 12:49:58 +11002027 * Used by fix_read_error() to decay the per rdev read_errors.
2028 * We halve the read error count for every hour that has elapsed
2029 * since the last recorded read error.
2030 *
2031 */
NeilBrownfd01b882011-10-11 16:47:53 +11002032static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
Robert Becker1e509152009-12-14 12:49:58 +11002033{
2034 struct timespec cur_time_mon;
2035 unsigned long hours_since_last;
2036 unsigned int read_errors = atomic_read(&rdev->read_errors);
2037
2038 ktime_get_ts(&cur_time_mon);
2039
2040 if (rdev->last_read_error.tv_sec == 0 &&
2041 rdev->last_read_error.tv_nsec == 0) {
2042 /* first time we've seen a read error */
2043 rdev->last_read_error = cur_time_mon;
2044 return;
2045 }
2046
2047 hours_since_last = (cur_time_mon.tv_sec -
2048 rdev->last_read_error.tv_sec) / 3600;
2049
2050 rdev->last_read_error = cur_time_mon;
2051
2052 /*
2053 * if hours_since_last is > the number of bits in read_errors
2054 * just set read errors to 0. We do this to avoid
2055 * overflowing the shift of read_errors by hours_since_last.
2056 */
2057 if (hours_since_last >= 8 * sizeof(read_errors))
2058 atomic_set(&rdev->read_errors, 0);
2059 else
2060 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
2061}
2062
NeilBrown3cb03002011-10-11 16:45:26 +11002063static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
NeilBrown58c54fc2011-07-28 11:39:25 +10002064 int sectors, struct page *page, int rw)
2065{
2066 sector_t first_bad;
2067 int bad_sectors;
2068
2069 if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
2070 && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
2071 return -1;
2072 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
2073 /* success */
2074 return 1;
NeilBrownb7044d42011-12-23 10:17:56 +11002075 if (rw == WRITE) {
NeilBrown58c54fc2011-07-28 11:39:25 +10002076 set_bit(WriteErrorSeen, &rdev->flags);
NeilBrownb7044d42011-12-23 10:17:56 +11002077 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2078 set_bit(MD_RECOVERY_NEEDED,
2079 &rdev->mddev->recovery);
2080 }
NeilBrown58c54fc2011-07-28 11:39:25 +10002081 /* need to record an error - either for the block or the device */
2082 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2083 md_error(rdev->mddev, rdev);
2084 return 0;
2085}
2086
Robert Becker1e509152009-12-14 12:49:58 +11002087/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088 * This is a kernel thread which:
2089 *
2090 * 1. Retries failed read operations on working mirrors.
2091 * 2. Updates the raid superblock when problems encounter.
NeilBrown6814d532006-10-03 01:15:45 -07002092 * 3. Performs writes following reads for array synchronising.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002093 */
2094
NeilBrowne879a872011-10-11 16:49:02 +11002095static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
NeilBrown6814d532006-10-03 01:15:45 -07002096{
2097 int sect = 0; /* Offset from r10_bio->sector */
2098 int sectors = r10_bio->sectors;
NeilBrown3cb03002011-10-11 16:45:26 +11002099 struct md_rdev*rdev;
Robert Becker1e509152009-12-14 12:49:58 +11002100 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10002101 int d = r10_bio->devs[r10_bio->read_slot].devnum;
Robert Becker1e509152009-12-14 12:49:58 +11002102
NeilBrown7c4e06f2011-05-11 14:53:17 +10002103 /* still own a reference to this rdev, so it cannot
2104 * have been cleared recently.
2105 */
2106 rdev = conf->mirrors[d].rdev;
Robert Becker1e509152009-12-14 12:49:58 +11002107
NeilBrown7c4e06f2011-05-11 14:53:17 +10002108 if (test_bit(Faulty, &rdev->flags))
2109 /* drive has already been failed, just ignore any
2110 more fix_read_error() attempts */
2111 return;
2112
2113 check_decay_read_errors(mddev, rdev);
2114 atomic_inc(&rdev->read_errors);
2115 if (atomic_read(&rdev->read_errors) > max_read_errors) {
2116 char b[BDEVNAME_SIZE];
Robert Becker1e509152009-12-14 12:49:58 +11002117 bdevname(rdev->bdev, b);
2118
NeilBrown7c4e06f2011-05-11 14:53:17 +10002119 printk(KERN_NOTICE
2120 "md/raid10:%s: %s: Raid device exceeded "
2121 "read_error threshold [cur %d:max %d]\n",
2122 mdname(mddev), b,
2123 atomic_read(&rdev->read_errors), max_read_errors);
2124 printk(KERN_NOTICE
2125 "md/raid10:%s: %s: Failing raid device\n",
2126 mdname(mddev), b);
2127 md_error(mddev, conf->mirrors[d].rdev);
NeilBrownfae8cc52012-02-14 11:10:10 +11002128 r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
NeilBrown7c4e06f2011-05-11 14:53:17 +10002129 return;
Robert Becker1e509152009-12-14 12:49:58 +11002130 }
Robert Becker1e509152009-12-14 12:49:58 +11002131
NeilBrown6814d532006-10-03 01:15:45 -07002132 while(sectors) {
2133 int s = sectors;
2134 int sl = r10_bio->read_slot;
2135 int success = 0;
2136 int start;
2137
2138 if (s > (PAGE_SIZE>>9))
2139 s = PAGE_SIZE >> 9;
2140
2141 rcu_read_lock();
2142 do {
NeilBrown8dbed5c2011-07-28 11:39:24 +10002143 sector_t first_bad;
2144 int bad_sectors;
2145
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10002146 d = r10_bio->devs[sl].devnum;
NeilBrown6814d532006-10-03 01:15:45 -07002147 rdev = rcu_dereference(conf->mirrors[d].rdev);
2148 if (rdev &&
NeilBrown050b6612012-03-19 12:46:39 +11002149 !test_bit(Unmerged, &rdev->flags) &&
NeilBrown8dbed5c2011-07-28 11:39:24 +10002150 test_bit(In_sync, &rdev->flags) &&
2151 is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
2152 &first_bad, &bad_sectors) == 0) {
NeilBrown6814d532006-10-03 01:15:45 -07002153 atomic_inc(&rdev->nr_pending);
2154 rcu_read_unlock();
NeilBrown2b193362010-10-27 15:16:40 +11002155 success = sync_page_io(rdev,
NeilBrown6814d532006-10-03 01:15:45 -07002156 r10_bio->devs[sl].addr +
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11002157 sect,
NeilBrown6814d532006-10-03 01:15:45 -07002158 s<<9,
Jonathan Brassowccebd4c2011-01-14 09:14:33 +11002159 conf->tmppage, READ, false);
NeilBrown6814d532006-10-03 01:15:45 -07002160 rdev_dec_pending(rdev, mddev);
2161 rcu_read_lock();
2162 if (success)
2163 break;
2164 }
2165 sl++;
2166 if (sl == conf->copies)
2167 sl = 0;
2168 } while (!success && sl != r10_bio->read_slot);
2169 rcu_read_unlock();
2170
2171 if (!success) {
NeilBrown58c54fc2011-07-28 11:39:25 +10002172 /* Cannot read from anywhere, just mark the block
2173 * as bad on the first device to discourage future
2174 * reads.
2175 */
NeilBrown6814d532006-10-03 01:15:45 -07002176 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
NeilBrown58c54fc2011-07-28 11:39:25 +10002177 rdev = conf->mirrors[dn].rdev;
2178
2179 if (!rdev_set_badblocks(
2180 rdev,
2181 r10_bio->devs[r10_bio->read_slot].addr
2182 + sect,
NeilBrownfae8cc52012-02-14 11:10:10 +11002183 s, 0)) {
NeilBrown58c54fc2011-07-28 11:39:25 +10002184 md_error(mddev, rdev);
NeilBrownfae8cc52012-02-14 11:10:10 +11002185 r10_bio->devs[r10_bio->read_slot].bio
2186 = IO_BLOCKED;
2187 }
NeilBrown6814d532006-10-03 01:15:45 -07002188 break;
2189 }
2190
2191 start = sl;
2192 /* write it back and re-read */
2193 rcu_read_lock();
2194 while (sl != r10_bio->read_slot) {
Robert Becker67b8dc42009-12-14 12:49:57 +11002195 char b[BDEVNAME_SIZE];
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10002196
NeilBrown6814d532006-10-03 01:15:45 -07002197 if (sl==0)
2198 sl = conf->copies;
2199 sl--;
2200 d = r10_bio->devs[sl].devnum;
2201 rdev = rcu_dereference(conf->mirrors[d].rdev);
NeilBrown1294b9c2011-07-28 11:39:23 +10002202 if (!rdev ||
NeilBrown050b6612012-03-19 12:46:39 +11002203 test_bit(Unmerged, &rdev->flags) ||
NeilBrown1294b9c2011-07-28 11:39:23 +10002204 !test_bit(In_sync, &rdev->flags))
2205 continue;
2206
2207 atomic_inc(&rdev->nr_pending);
2208 rcu_read_unlock();
NeilBrown58c54fc2011-07-28 11:39:25 +10002209 if (r10_sync_page_io(rdev,
2210 r10_bio->devs[sl].addr +
2211 sect,
2212 s<<9, conf->tmppage, WRITE)
NeilBrown1294b9c2011-07-28 11:39:23 +10002213 == 0) {
2214 /* Well, this device is dead */
2215 printk(KERN_NOTICE
2216 "md/raid10:%s: read correction "
2217 "write failed"
2218 " (%d sectors at %llu on %s)\n",
2219 mdname(mddev), s,
2220 (unsigned long long)(
2221 sect + rdev->data_offset),
2222 bdevname(rdev->bdev, b));
2223 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
2224 "drive\n",
2225 mdname(mddev),
2226 bdevname(rdev->bdev, b));
NeilBrown6814d532006-10-03 01:15:45 -07002227 }
NeilBrown1294b9c2011-07-28 11:39:23 +10002228 rdev_dec_pending(rdev, mddev);
2229 rcu_read_lock();
NeilBrown6814d532006-10-03 01:15:45 -07002230 }
2231 sl = start;
2232 while (sl != r10_bio->read_slot) {
NeilBrown1294b9c2011-07-28 11:39:23 +10002233 char b[BDEVNAME_SIZE];
Prasanna S. Panchamukhi0544a212010-06-24 13:31:03 +10002234
NeilBrown6814d532006-10-03 01:15:45 -07002235 if (sl==0)
2236 sl = conf->copies;
2237 sl--;
2238 d = r10_bio->devs[sl].devnum;
2239 rdev = rcu_dereference(conf->mirrors[d].rdev);
NeilBrown1294b9c2011-07-28 11:39:23 +10002240 if (!rdev ||
2241 !test_bit(In_sync, &rdev->flags))
2242 continue;
Robert Becker67b8dc42009-12-14 12:49:57 +11002243
NeilBrown1294b9c2011-07-28 11:39:23 +10002244 atomic_inc(&rdev->nr_pending);
2245 rcu_read_unlock();
NeilBrown58c54fc2011-07-28 11:39:25 +10002246 switch (r10_sync_page_io(rdev,
2247 r10_bio->devs[sl].addr +
2248 sect,
2249 s<<9, conf->tmppage,
2250 READ)) {
2251 case 0:
NeilBrown1294b9c2011-07-28 11:39:23 +10002252 /* Well, this device is dead */
2253 printk(KERN_NOTICE
2254 "md/raid10:%s: unable to read back "
2255 "corrected sectors"
2256 " (%d sectors at %llu on %s)\n",
2257 mdname(mddev), s,
2258 (unsigned long long)(
2259 sect + rdev->data_offset),
2260 bdevname(rdev->bdev, b));
2261 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
2262 "drive\n",
2263 mdname(mddev),
2264 bdevname(rdev->bdev, b));
NeilBrown58c54fc2011-07-28 11:39:25 +10002265 break;
2266 case 1:
NeilBrown1294b9c2011-07-28 11:39:23 +10002267 printk(KERN_INFO
2268 "md/raid10:%s: read error corrected"
2269 " (%d sectors at %llu on %s)\n",
2270 mdname(mddev), s,
2271 (unsigned long long)(
2272 sect + rdev->data_offset),
2273 bdevname(rdev->bdev, b));
2274 atomic_add(s, &rdev->corrected_errors);
NeilBrown6814d532006-10-03 01:15:45 -07002275 }
NeilBrown1294b9c2011-07-28 11:39:23 +10002276
2277 rdev_dec_pending(rdev, mddev);
2278 rcu_read_lock();
NeilBrown6814d532006-10-03 01:15:45 -07002279 }
2280 rcu_read_unlock();
2281
2282 sectors -= s;
2283 sect += s;
2284 }
2285}
2286
NeilBrownbd870a12011-07-28 11:39:24 +10002287static void bi_complete(struct bio *bio, int error)
2288{
2289 complete((struct completion *)bio->bi_private);
2290}
2291
2292static int submit_bio_wait(int rw, struct bio *bio)
2293{
2294 struct completion event;
2295 rw |= REQ_SYNC;
2296
2297 init_completion(&event);
2298 bio->bi_private = &event;
2299 bio->bi_end_io = bi_complete;
2300 submit_bio(rw, bio);
2301 wait_for_completion(&event);
2302
2303 return test_bit(BIO_UPTODATE, &bio->bi_flags);
2304}
2305
NeilBrown9f2c9d12011-10-11 16:48:43 +11002306static int narrow_write_error(struct r10bio *r10_bio, int i)
NeilBrownbd870a12011-07-28 11:39:24 +10002307{
2308 struct bio *bio = r10_bio->master_bio;
NeilBrownfd01b882011-10-11 16:47:53 +11002309 struct mddev *mddev = r10_bio->mddev;
NeilBrowne879a872011-10-11 16:49:02 +11002310 struct r10conf *conf = mddev->private;
NeilBrown3cb03002011-10-11 16:45:26 +11002311 struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
NeilBrownbd870a12011-07-28 11:39:24 +10002312 /* bio has the data to be written to slot 'i' where
2313 * we just recently had a write error.
2314 * We repeatedly clone the bio and trim down to one block,
2315 * then try the write. Where the write fails we record
2316 * a bad block.
2317 * It is conceivable that the bio doesn't exactly align with
2318 * blocks. We must handle this.
2319 *
2320 * We currently own a reference to the rdev.
2321 */
2322
2323 int block_sectors;
2324 sector_t sector;
2325 int sectors;
2326 int sect_to_write = r10_bio->sectors;
2327 int ok = 1;
2328
2329 if (rdev->badblocks.shift < 0)
2330 return 0;
2331
2332 block_sectors = 1 << rdev->badblocks.shift;
2333 sector = r10_bio->sector;
2334 sectors = ((r10_bio->sector + block_sectors)
2335 & ~(sector_t)(block_sectors - 1))
2336 - sector;
2337
2338 while (sect_to_write) {
2339 struct bio *wbio;
2340 if (sectors > sect_to_write)
2341 sectors = sect_to_write;
2342 /* Write at 'sector' for 'sectors' */
2343 wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
2344 md_trim_bio(wbio, sector - bio->bi_sector, sectors);
2345 wbio->bi_sector = (r10_bio->devs[i].addr+
2346 rdev->data_offset+
2347 (sector - r10_bio->sector));
2348 wbio->bi_bdev = rdev->bdev;
2349 if (submit_bio_wait(WRITE, wbio) == 0)
2350 /* Failure! */
2351 ok = rdev_set_badblocks(rdev, sector,
2352 sectors, 0)
2353 && ok;
2354
2355 bio_put(wbio);
2356 sect_to_write -= sectors;
2357 sector += sectors;
2358 sectors = block_sectors;
2359 }
2360 return ok;
2361}
2362
NeilBrown9f2c9d12011-10-11 16:48:43 +11002363static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
NeilBrown560f8e52011-07-28 11:39:23 +10002364{
2365 int slot = r10_bio->read_slot;
NeilBrown560f8e52011-07-28 11:39:23 +10002366 struct bio *bio;
NeilBrowne879a872011-10-11 16:49:02 +11002367 struct r10conf *conf = mddev->private;
NeilBrownabbf0982011-12-23 10:17:54 +11002368 struct md_rdev *rdev = r10_bio->devs[slot].rdev;
NeilBrown560f8e52011-07-28 11:39:23 +10002369 char b[BDEVNAME_SIZE];
2370 unsigned long do_sync;
NeilBrown856e08e2011-07-28 11:39:23 +10002371 int max_sectors;
NeilBrown560f8e52011-07-28 11:39:23 +10002372
2373 /* we got a read error. Maybe the drive is bad. Maybe just
2374 * the block and we can fix it.
2375 * We freeze all other IO, and try reading the block from
2376 * other devices. When we find one, we re-write
2377 * and check it that fixes the read error.
2378 * This is all done synchronously while the array is
2379 * frozen.
2380 */
NeilBrownfae8cc52012-02-14 11:10:10 +11002381 bio = r10_bio->devs[slot].bio;
2382 bdevname(bio->bi_bdev, b);
2383 bio_put(bio);
2384 r10_bio->devs[slot].bio = NULL;
2385
NeilBrown560f8e52011-07-28 11:39:23 +10002386 if (mddev->ro == 0) {
2387 freeze_array(conf);
2388 fix_read_error(conf, mddev, r10_bio);
2389 unfreeze_array(conf);
NeilBrownfae8cc52012-02-14 11:10:10 +11002390 } else
2391 r10_bio->devs[slot].bio = IO_BLOCKED;
2392
NeilBrownabbf0982011-12-23 10:17:54 +11002393 rdev_dec_pending(rdev, mddev);
NeilBrown560f8e52011-07-28 11:39:23 +10002394
NeilBrown7399c312011-07-28 11:39:23 +10002395read_more:
NeilBrown96c3fd12011-12-23 10:17:54 +11002396 rdev = read_balance(conf, r10_bio, &max_sectors);
2397 if (rdev == NULL) {
NeilBrown560f8e52011-07-28 11:39:23 +10002398 printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
2399 " read error for block %llu\n",
NeilBrown7399c312011-07-28 11:39:23 +10002400 mdname(mddev), b,
NeilBrown560f8e52011-07-28 11:39:23 +10002401 (unsigned long long)r10_bio->sector);
2402 raid_end_bio_io(r10_bio);
NeilBrown560f8e52011-07-28 11:39:23 +10002403 return;
2404 }
2405
2406 do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
NeilBrown560f8e52011-07-28 11:39:23 +10002407 slot = r10_bio->read_slot;
NeilBrown560f8e52011-07-28 11:39:23 +10002408 printk_ratelimited(
2409 KERN_ERR
2410 "md/raid10:%s: %s: redirecting"
2411 "sector %llu to another mirror\n",
2412 mdname(mddev),
2413 bdevname(rdev->bdev, b),
2414 (unsigned long long)r10_bio->sector);
2415 bio = bio_clone_mddev(r10_bio->master_bio,
2416 GFP_NOIO, mddev);
NeilBrown7399c312011-07-28 11:39:23 +10002417 md_trim_bio(bio,
2418 r10_bio->sector - bio->bi_sector,
2419 max_sectors);
NeilBrown560f8e52011-07-28 11:39:23 +10002420 r10_bio->devs[slot].bio = bio;
NeilBrownabbf0982011-12-23 10:17:54 +11002421 r10_bio->devs[slot].rdev = rdev;
NeilBrown560f8e52011-07-28 11:39:23 +10002422 bio->bi_sector = r10_bio->devs[slot].addr
2423 + rdev->data_offset;
2424 bio->bi_bdev = rdev->bdev;
2425 bio->bi_rw = READ | do_sync;
2426 bio->bi_private = r10_bio;
2427 bio->bi_end_io = raid10_end_read_request;
NeilBrown7399c312011-07-28 11:39:23 +10002428 if (max_sectors < r10_bio->sectors) {
2429 /* Drat - have to split this up more */
2430 struct bio *mbio = r10_bio->master_bio;
2431 int sectors_handled =
2432 r10_bio->sector + max_sectors
2433 - mbio->bi_sector;
2434 r10_bio->sectors = max_sectors;
2435 spin_lock_irq(&conf->device_lock);
2436 if (mbio->bi_phys_segments == 0)
2437 mbio->bi_phys_segments = 2;
2438 else
2439 mbio->bi_phys_segments++;
2440 spin_unlock_irq(&conf->device_lock);
2441 generic_make_request(bio);
NeilBrown7399c312011-07-28 11:39:23 +10002442
2443 r10_bio = mempool_alloc(conf->r10bio_pool,
2444 GFP_NOIO);
2445 r10_bio->master_bio = mbio;
2446 r10_bio->sectors = (mbio->bi_size >> 9)
2447 - sectors_handled;
2448 r10_bio->state = 0;
2449 set_bit(R10BIO_ReadError,
2450 &r10_bio->state);
2451 r10_bio->mddev = mddev;
2452 r10_bio->sector = mbio->bi_sector
2453 + sectors_handled;
2454
2455 goto read_more;
2456 } else
2457 generic_make_request(bio);
NeilBrown560f8e52011-07-28 11:39:23 +10002458}
2459
NeilBrowne879a872011-10-11 16:49:02 +11002460static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
NeilBrown749c55e2011-07-28 11:39:24 +10002461{
2462 /* Some sort of write request has finished and it
2463 * succeeded in writing where we thought there was a
2464 * bad block. So forget the bad block.
NeilBrown1a0b7cd2011-07-28 11:39:25 +10002465 * Or possibly if failed and we need to record
2466 * a bad block.
NeilBrown749c55e2011-07-28 11:39:24 +10002467 */
2468 int m;
NeilBrown3cb03002011-10-11 16:45:26 +11002469 struct md_rdev *rdev;
NeilBrown749c55e2011-07-28 11:39:24 +10002470
2471 if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
2472 test_bit(R10BIO_IsRecover, &r10_bio->state)) {
NeilBrown1a0b7cd2011-07-28 11:39:25 +10002473 for (m = 0; m < conf->copies; m++) {
2474 int dev = r10_bio->devs[m].devnum;
2475 rdev = conf->mirrors[dev].rdev;
2476 if (r10_bio->devs[m].bio == NULL)
2477 continue;
2478 if (test_bit(BIO_UPTODATE,
NeilBrown749c55e2011-07-28 11:39:24 +10002479 &r10_bio->devs[m].bio->bi_flags)) {
NeilBrown749c55e2011-07-28 11:39:24 +10002480 rdev_clear_badblocks(
2481 rdev,
2482 r10_bio->devs[m].addr,
2483 r10_bio->sectors);
NeilBrown1a0b7cd2011-07-28 11:39:25 +10002484 } else {
2485 if (!rdev_set_badblocks(
2486 rdev,
2487 r10_bio->devs[m].addr,
2488 r10_bio->sectors, 0))
2489 md_error(conf->mddev, rdev);
NeilBrown749c55e2011-07-28 11:39:24 +10002490 }
NeilBrown9ad1aef2011-12-23 10:17:55 +11002491 rdev = conf->mirrors[dev].replacement;
2492 if (r10_bio->devs[m].repl_bio == NULL)
2493 continue;
2494 if (test_bit(BIO_UPTODATE,
2495 &r10_bio->devs[m].repl_bio->bi_flags)) {
2496 rdev_clear_badblocks(
2497 rdev,
2498 r10_bio->devs[m].addr,
2499 r10_bio->sectors);
2500 } else {
2501 if (!rdev_set_badblocks(
2502 rdev,
2503 r10_bio->devs[m].addr,
2504 r10_bio->sectors, 0))
2505 md_error(conf->mddev, rdev);
2506 }
NeilBrown1a0b7cd2011-07-28 11:39:25 +10002507 }
NeilBrown749c55e2011-07-28 11:39:24 +10002508 put_buf(r10_bio);
2509 } else {
NeilBrownbd870a12011-07-28 11:39:24 +10002510 for (m = 0; m < conf->copies; m++) {
2511 int dev = r10_bio->devs[m].devnum;
2512 struct bio *bio = r10_bio->devs[m].bio;
2513 rdev = conf->mirrors[dev].rdev;
2514 if (bio == IO_MADE_GOOD) {
NeilBrown749c55e2011-07-28 11:39:24 +10002515 rdev_clear_badblocks(
2516 rdev,
2517 r10_bio->devs[m].addr,
2518 r10_bio->sectors);
2519 rdev_dec_pending(rdev, conf->mddev);
NeilBrownbd870a12011-07-28 11:39:24 +10002520 } else if (bio != NULL &&
2521 !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2522 if (!narrow_write_error(r10_bio, m)) {
2523 md_error(conf->mddev, rdev);
2524 set_bit(R10BIO_Degraded,
2525 &r10_bio->state);
2526 }
2527 rdev_dec_pending(rdev, conf->mddev);
NeilBrown749c55e2011-07-28 11:39:24 +10002528 }
NeilBrown475b0322011-12-23 10:17:55 +11002529 bio = r10_bio->devs[m].repl_bio;
2530 rdev = conf->mirrors[dev].replacement;
NeilBrown4ca40c22011-12-23 10:17:55 +11002531 if (rdev && bio == IO_MADE_GOOD) {
NeilBrown475b0322011-12-23 10:17:55 +11002532 rdev_clear_badblocks(
2533 rdev,
2534 r10_bio->devs[m].addr,
2535 r10_bio->sectors);
2536 rdev_dec_pending(rdev, conf->mddev);
2537 }
NeilBrownbd870a12011-07-28 11:39:24 +10002538 }
2539 if (test_bit(R10BIO_WriteError,
2540 &r10_bio->state))
2541 close_write(r10_bio);
NeilBrown749c55e2011-07-28 11:39:24 +10002542 raid_end_bio_io(r10_bio);
2543 }
2544}
2545
NeilBrownfd01b882011-10-11 16:47:53 +11002546static void raid10d(struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002547{
NeilBrown9f2c9d12011-10-11 16:48:43 +11002548 struct r10bio *r10_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002549 unsigned long flags;
NeilBrowne879a872011-10-11 16:49:02 +11002550 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002551 struct list_head *head = &conf->retry_list;
NeilBrowne1dfa0a2011-04-18 18:25:41 +10002552 struct blk_plug plug;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553
2554 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002555
NeilBrowne1dfa0a2011-04-18 18:25:41 +10002556 blk_start_plug(&plug);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002557 for (;;) {
NeilBrowna35e63e2008-03-04 14:29:29 -08002558
Jens Axboe7eaceac2011-03-10 08:52:07 +01002559 flush_pending_writes(conf);
NeilBrowna35e63e2008-03-04 14:29:29 -08002560
Linus Torvalds1da177e2005-04-16 15:20:36 -07002561 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrowna35e63e2008-03-04 14:29:29 -08002562 if (list_empty(head)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08002563 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564 break;
NeilBrowna35e63e2008-03-04 14:29:29 -08002565 }
NeilBrown9f2c9d12011-10-11 16:48:43 +11002566 r10_bio = list_entry(head->prev, struct r10bio, retry_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002567 list_del(head->prev);
NeilBrown4443ae12006-01-06 00:20:28 -08002568 conf->nr_queued--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002569 spin_unlock_irqrestore(&conf->device_lock, flags);
2570
2571 mddev = r10_bio->mddev;
NeilBrown070ec552009-06-16 16:54:21 +10002572 conf = mddev->private;
NeilBrownbd870a12011-07-28 11:39:24 +10002573 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
2574 test_bit(R10BIO_WriteError, &r10_bio->state))
NeilBrown749c55e2011-07-28 11:39:24 +10002575 handle_write_completed(conf, r10_bio);
2576 else if (test_bit(R10BIO_IsSync, &r10_bio->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577 sync_request_write(mddev, r10_bio);
Jens Axboe7eaceac2011-03-10 08:52:07 +01002578 else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002579 recovery_request_write(mddev, r10_bio);
NeilBrown856e08e2011-07-28 11:39:23 +10002580 else if (test_bit(R10BIO_ReadError, &r10_bio->state))
NeilBrown560f8e52011-07-28 11:39:23 +10002581 handle_read_error(mddev, r10_bio);
NeilBrown856e08e2011-07-28 11:39:23 +10002582 else {
2583 /* just a partial read to be scheduled from a
2584 * separate context
2585 */
2586 int slot = r10_bio->read_slot;
2587 generic_make_request(r10_bio->devs[slot].bio);
2588 }
NeilBrown4443ae12006-01-06 00:20:28 -08002589
NeilBrown1d9d5242009-10-16 15:55:32 +11002590 cond_resched();
NeilBrownde393cd2011-07-28 11:31:48 +10002591 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2592 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002593 }
NeilBrowne1dfa0a2011-04-18 18:25:41 +10002594 blk_finish_plug(&plug);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002595}
2596
2597
NeilBrowne879a872011-10-11 16:49:02 +11002598static int init_resync(struct r10conf *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002599{
2600 int buffs;
NeilBrown69335ef2011-12-23 10:17:54 +11002601 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002602
2603 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
Eric Sesterhennb6385482006-04-02 13:34:29 +02002604 BUG_ON(conf->r10buf_pool);
NeilBrown69335ef2011-12-23 10:17:54 +11002605 conf->have_replacement = 0;
2606 for (i = 0; i < conf->raid_disks; i++)
2607 if (conf->mirrors[i].replacement)
2608 conf->have_replacement = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002609 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
2610 if (!conf->r10buf_pool)
2611 return -ENOMEM;
2612 conf->next_resync = 0;
2613 return 0;
2614}
2615
2616/*
2617 * perform a "sync" on one "block"
2618 *
2619 * We need to make sure that no normal I/O request - particularly write
2620 * requests - conflict with active sync requests.
2621 *
2622 * This is achieved by tracking pending requests and a 'barrier' concept
2623 * that can be installed to exclude normal IO requests.
2624 *
2625 * Resync and recovery are handled very differently.
2626 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2627 *
2628 * For resync, we iterate over virtual addresses, read all copies,
2629 * and update if there are differences. If only one copy is live,
2630 * skip it.
2631 * For recovery, we iterate over physical addresses, read a good
2632 * value for each non-in_sync drive, and over-write.
2633 *
2634 * So, for recovery we may have several outstanding complex requests for a
2635 * given address, one for each out-of-sync device. We model this by allocating
2636 * a number of r10_bio structures, one for each out-of-sync device.
2637 * As we setup these structures, we collect all bio's together into a list
2638 * which we then process collectively to add pages, and then process again
2639 * to pass to generic_make_request.
2640 *
2641 * The r10_bio structures are linked using a borrowed master_bio pointer.
2642 * This link is counted in ->remaining. When the r10_bio that points to NULL
2643 * has its remaining count decremented to 0, the whole complex operation
2644 * is complete.
2645 *
2646 */
2647
NeilBrownfd01b882011-10-11 16:47:53 +11002648static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
NeilBrownab9d47e2011-05-11 14:54:41 +10002649 int *skipped, int go_faster)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002650{
NeilBrowne879a872011-10-11 16:49:02 +11002651 struct r10conf *conf = mddev->private;
NeilBrown9f2c9d12011-10-11 16:48:43 +11002652 struct r10bio *r10_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002653 struct bio *biolist = NULL, *bio;
2654 sector_t max_sector, nr_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002655 int i;
NeilBrown6cce3b22006-01-06 00:20:16 -08002656 int max_sync;
NeilBrown57dab0b2010-10-19 10:03:39 +11002657 sector_t sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002658 sector_t sectors_skipped = 0;
2659 int chunks_skipped = 0;
2660
2661 if (!conf->r10buf_pool)
2662 if (init_resync(conf))
NeilBrown57afd892005-06-21 17:17:13 -07002663 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002664
2665 skipped:
Andre Noll58c0fed2009-03-31 14:33:13 +11002666 max_sector = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002667 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2668 max_sector = mddev->resync_max_sectors;
2669 if (sector_nr >= max_sector) {
NeilBrown6cce3b22006-01-06 00:20:16 -08002670 /* If we aborted, we need to abort the
2671 * sync on the 'current' bitmap chucks (there can
2672 * be several when recovering multiple devices).
2673 * as we may have started syncing it but not finished.
2674 * We can find the current address in
2675 * mddev->curr_resync, but for recovery,
2676 * we need to convert that to several
2677 * virtual addresses.
2678 */
2679 if (mddev->curr_resync < max_sector) { /* aborted */
2680 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2681 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2682 &sync_blocks, 1);
2683 else for (i=0; i<conf->raid_disks; i++) {
2684 sector_t sect =
2685 raid10_find_virt(conf, mddev->curr_resync, i);
2686 bitmap_end_sync(mddev->bitmap, sect,
2687 &sync_blocks, 1);
2688 }
NeilBrown9ad1aef2011-12-23 10:17:55 +11002689 } else {
2690 /* completed sync */
2691 if ((!mddev->bitmap || conf->fullsync)
2692 && conf->have_replacement
2693 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2694 /* Completed a full sync so the replacements
2695 * are now fully recovered.
2696 */
2697 for (i = 0; i < conf->raid_disks; i++)
2698 if (conf->mirrors[i].replacement)
2699 conf->mirrors[i].replacement
2700 ->recovery_offset
2701 = MaxSector;
2702 }
NeilBrown6cce3b22006-01-06 00:20:16 -08002703 conf->fullsync = 0;
NeilBrown9ad1aef2011-12-23 10:17:55 +11002704 }
NeilBrown6cce3b22006-01-06 00:20:16 -08002705 bitmap_close_sync(mddev->bitmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706 close_sync(conf);
NeilBrown57afd892005-06-21 17:17:13 -07002707 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002708 return sectors_skipped;
2709 }
2710 if (chunks_skipped >= conf->raid_disks) {
2711 /* if there has been nothing to do on any drive,
2712 * then there is nothing to do at all..
2713 */
NeilBrown57afd892005-06-21 17:17:13 -07002714 *skipped = 1;
2715 return (max_sector - sector_nr) + sectors_skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716 }
2717
NeilBrownc6207272008-02-06 01:39:52 -08002718 if (max_sector > mddev->resync_max)
2719 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2720
Linus Torvalds1da177e2005-04-16 15:20:36 -07002721 /* make sure whole request will fit in a chunk - if chunks
2722 * are meaningful
2723 */
2724 if (conf->near_copies < conf->raid_disks &&
2725 max_sector > (sector_nr | conf->chunk_mask))
2726 max_sector = (sector_nr | conf->chunk_mask) + 1;
2727 /*
2728 * If there is non-resync activity waiting for us then
2729 * put in a delay to throttle resync.
2730 */
NeilBrown0a27ec92006-01-06 00:20:13 -08002731 if (!go_faster && conf->nr_waiting)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002732 msleep_interruptible(1000);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733
2734 /* Again, very different code for resync and recovery.
2735 * Both must result in an r10bio with a list of bios that
2736 * have bi_end_io, bi_sector, bi_bdev set,
2737 * and bi_private set to the r10bio.
2738 * For recovery, we may actually create several r10bios
2739 * with 2 bios in each, that correspond to the bios in the main one.
2740 * In this case, the subordinate r10bios link back through a
2741 * borrowed master_bio pointer, and the counter in the master
2742 * includes a ref from each subordinate.
2743 */
2744 /* First, we decide what to do and set ->bi_end_io
2745 * To end_sync_read if we want to read, and
2746 * end_sync_write if we will want to write.
2747 */
2748
NeilBrown6cce3b22006-01-06 00:20:16 -08002749 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002750 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2751 /* recovery... the complicated one */
NeilBrowne875ece2011-07-28 11:39:24 +10002752 int j;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002753 r10_bio = NULL;
2754
NeilBrownab9d47e2011-05-11 14:54:41 +10002755 for (i=0 ; i<conf->raid_disks; i++) {
2756 int still_degraded;
NeilBrown9f2c9d12011-10-11 16:48:43 +11002757 struct r10bio *rb2;
NeilBrownab9d47e2011-05-11 14:54:41 +10002758 sector_t sect;
2759 int must_sync;
NeilBrowne875ece2011-07-28 11:39:24 +10002760 int any_working;
NeilBrown24afd802011-12-23 10:17:55 +11002761 struct mirror_info *mirror = &conf->mirrors[i];
NeilBrownab9d47e2011-05-11 14:54:41 +10002762
NeilBrown24afd802011-12-23 10:17:55 +11002763 if ((mirror->rdev == NULL ||
2764 test_bit(In_sync, &mirror->rdev->flags))
2765 &&
2766 (mirror->replacement == NULL ||
2767 test_bit(Faulty,
2768 &mirror->replacement->flags)))
NeilBrownab9d47e2011-05-11 14:54:41 +10002769 continue;
2770
2771 still_degraded = 0;
2772 /* want to reconstruct this device */
2773 rb2 = r10_bio;
2774 sect = raid10_find_virt(conf, sector_nr, i);
NeilBrown24afd802011-12-23 10:17:55 +11002775 /* Unless we are doing a full sync, or a replacement
2776 * we only need to recover the block if it is set in
2777 * the bitmap
NeilBrownab9d47e2011-05-11 14:54:41 +10002778 */
2779 must_sync = bitmap_start_sync(mddev->bitmap, sect,
2780 &sync_blocks, 1);
2781 if (sync_blocks < max_sync)
2782 max_sync = sync_blocks;
2783 if (!must_sync &&
NeilBrown24afd802011-12-23 10:17:55 +11002784 mirror->replacement == NULL &&
NeilBrownab9d47e2011-05-11 14:54:41 +10002785 !conf->fullsync) {
2786 /* yep, skip the sync_blocks here, but don't assume
2787 * that there will never be anything to do here
NeilBrown6cce3b22006-01-06 00:20:16 -08002788 */
NeilBrownab9d47e2011-05-11 14:54:41 +10002789 chunks_skipped = -1;
2790 continue;
2791 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002792
NeilBrownab9d47e2011-05-11 14:54:41 +10002793 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
2794 raise_barrier(conf, rb2 != NULL);
2795 atomic_set(&r10_bio->remaining, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002796
NeilBrownab9d47e2011-05-11 14:54:41 +10002797 r10_bio->master_bio = (struct bio*)rb2;
2798 if (rb2)
2799 atomic_inc(&rb2->remaining);
2800 r10_bio->mddev = mddev;
2801 set_bit(R10BIO_IsRecover, &r10_bio->state);
2802 r10_bio->sector = sect;
NeilBrown6cce3b22006-01-06 00:20:16 -08002803
NeilBrownab9d47e2011-05-11 14:54:41 +10002804 raid10_find_phys(conf, r10_bio);
NeilBrown18055562009-05-07 12:48:10 +10002805
NeilBrownab9d47e2011-05-11 14:54:41 +10002806 /* Need to check if the array will still be
2807 * degraded
2808 */
2809 for (j=0; j<conf->raid_disks; j++)
2810 if (conf->mirrors[j].rdev == NULL ||
2811 test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
2812 still_degraded = 1;
NeilBrown87fc7672005-09-09 16:24:04 -07002813 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002814 }
NeilBrownab9d47e2011-05-11 14:54:41 +10002815
2816 must_sync = bitmap_start_sync(mddev->bitmap, sect,
2817 &sync_blocks, still_degraded);
2818
NeilBrowne875ece2011-07-28 11:39:24 +10002819 any_working = 0;
NeilBrownab9d47e2011-05-11 14:54:41 +10002820 for (j=0; j<conf->copies;j++) {
NeilBrowne875ece2011-07-28 11:39:24 +10002821 int k;
NeilBrownab9d47e2011-05-11 14:54:41 +10002822 int d = r10_bio->devs[j].devnum;
NeilBrown5e570282011-07-28 11:39:25 +10002823 sector_t from_addr, to_addr;
NeilBrown3cb03002011-10-11 16:45:26 +11002824 struct md_rdev *rdev;
NeilBrown40c356c2011-07-28 11:39:24 +10002825 sector_t sector, first_bad;
2826 int bad_sectors;
NeilBrownab9d47e2011-05-11 14:54:41 +10002827 if (!conf->mirrors[d].rdev ||
2828 !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
2829 continue;
2830 /* This is where we read from */
NeilBrowne875ece2011-07-28 11:39:24 +10002831 any_working = 1;
NeilBrown40c356c2011-07-28 11:39:24 +10002832 rdev = conf->mirrors[d].rdev;
2833 sector = r10_bio->devs[j].addr;
2834
2835 if (is_badblock(rdev, sector, max_sync,
2836 &first_bad, &bad_sectors)) {
2837 if (first_bad > sector)
2838 max_sync = first_bad - sector;
2839 else {
2840 bad_sectors -= (sector
2841 - first_bad);
2842 if (max_sync > bad_sectors)
2843 max_sync = bad_sectors;
2844 continue;
2845 }
2846 }
NeilBrownab9d47e2011-05-11 14:54:41 +10002847 bio = r10_bio->devs[0].bio;
2848 bio->bi_next = biolist;
2849 biolist = bio;
2850 bio->bi_private = r10_bio;
2851 bio->bi_end_io = end_sync_read;
2852 bio->bi_rw = READ;
NeilBrown5e570282011-07-28 11:39:25 +10002853 from_addr = r10_bio->devs[j].addr;
NeilBrown24afd802011-12-23 10:17:55 +11002854 bio->bi_sector = from_addr + rdev->data_offset;
2855 bio->bi_bdev = rdev->bdev;
2856 atomic_inc(&rdev->nr_pending);
2857 /* and we write to 'i' (if not in_sync) */
NeilBrownab9d47e2011-05-11 14:54:41 +10002858
2859 for (k=0; k<conf->copies; k++)
2860 if (r10_bio->devs[k].devnum == i)
2861 break;
2862 BUG_ON(k == conf->copies);
NeilBrown5e570282011-07-28 11:39:25 +10002863 to_addr = r10_bio->devs[k].addr;
NeilBrownab9d47e2011-05-11 14:54:41 +10002864 r10_bio->devs[0].devnum = d;
NeilBrown5e570282011-07-28 11:39:25 +10002865 r10_bio->devs[0].addr = from_addr;
NeilBrownab9d47e2011-05-11 14:54:41 +10002866 r10_bio->devs[1].devnum = i;
NeilBrown5e570282011-07-28 11:39:25 +10002867 r10_bio->devs[1].addr = to_addr;
NeilBrownab9d47e2011-05-11 14:54:41 +10002868
NeilBrown24afd802011-12-23 10:17:55 +11002869 rdev = mirror->rdev;
2870 if (!test_bit(In_sync, &rdev->flags)) {
2871 bio = r10_bio->devs[1].bio;
2872 bio->bi_next = biolist;
2873 biolist = bio;
2874 bio->bi_private = r10_bio;
2875 bio->bi_end_io = end_sync_write;
2876 bio->bi_rw = WRITE;
2877 bio->bi_sector = to_addr
2878 + rdev->data_offset;
2879 bio->bi_bdev = rdev->bdev;
2880 atomic_inc(&r10_bio->remaining);
2881 } else
2882 r10_bio->devs[1].bio->bi_end_io = NULL;
2883
2884 /* and maybe write to replacement */
2885 bio = r10_bio->devs[1].repl_bio;
2886 if (bio)
2887 bio->bi_end_io = NULL;
2888 rdev = mirror->replacement;
2889 /* Note: if rdev != NULL, then bio
2890 * cannot be NULL as r10buf_pool_alloc will
2891 * have allocated it.
2892 * So the second test here is pointless.
2893 * But it keeps semantic-checkers happy, and
2894 * this comment keeps human reviewers
2895 * happy.
2896 */
2897 if (rdev == NULL || bio == NULL ||
2898 test_bit(Faulty, &rdev->flags))
2899 break;
2900 bio->bi_next = biolist;
2901 biolist = bio;
2902 bio->bi_private = r10_bio;
2903 bio->bi_end_io = end_sync_write;
2904 bio->bi_rw = WRITE;
2905 bio->bi_sector = to_addr + rdev->data_offset;
2906 bio->bi_bdev = rdev->bdev;
2907 atomic_inc(&r10_bio->remaining);
NeilBrownab9d47e2011-05-11 14:54:41 +10002908 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002909 }
NeilBrownab9d47e2011-05-11 14:54:41 +10002910 if (j == conf->copies) {
NeilBrowne875ece2011-07-28 11:39:24 +10002911 /* Cannot recover, so abort the recovery or
2912 * record a bad block */
NeilBrownab9d47e2011-05-11 14:54:41 +10002913 put_buf(r10_bio);
2914 if (rb2)
2915 atomic_dec(&rb2->remaining);
2916 r10_bio = rb2;
NeilBrowne875ece2011-07-28 11:39:24 +10002917 if (any_working) {
2918 /* problem is that there are bad blocks
2919 * on other device(s)
2920 */
2921 int k;
2922 for (k = 0; k < conf->copies; k++)
2923 if (r10_bio->devs[k].devnum == i)
2924 break;
NeilBrown24afd802011-12-23 10:17:55 +11002925 if (!test_bit(In_sync,
2926 &mirror->rdev->flags)
2927 && !rdev_set_badblocks(
2928 mirror->rdev,
2929 r10_bio->devs[k].addr,
2930 max_sync, 0))
2931 any_working = 0;
2932 if (mirror->replacement &&
2933 !rdev_set_badblocks(
2934 mirror->replacement,
NeilBrowne875ece2011-07-28 11:39:24 +10002935 r10_bio->devs[k].addr,
2936 max_sync, 0))
2937 any_working = 0;
2938 }
2939 if (!any_working) {
2940 if (!test_and_set_bit(MD_RECOVERY_INTR,
2941 &mddev->recovery))
2942 printk(KERN_INFO "md/raid10:%s: insufficient "
2943 "working devices for recovery.\n",
2944 mdname(mddev));
NeilBrown24afd802011-12-23 10:17:55 +11002945 mirror->recovery_disabled
NeilBrowne875ece2011-07-28 11:39:24 +10002946 = mddev->recovery_disabled;
2947 }
NeilBrownab9d47e2011-05-11 14:54:41 +10002948 break;
2949 }
2950 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002951 if (biolist == NULL) {
2952 while (r10_bio) {
NeilBrown9f2c9d12011-10-11 16:48:43 +11002953 struct r10bio *rb2 = r10_bio;
2954 r10_bio = (struct r10bio*) rb2->master_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002955 rb2->master_bio = NULL;
2956 put_buf(rb2);
2957 }
2958 goto giveup;
2959 }
2960 } else {
2961 /* resync. Schedule a read for every block at this virt offset */
2962 int count = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08002963
NeilBrown78200d42009-02-25 13:18:47 +11002964 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2965
NeilBrown6cce3b22006-01-06 00:20:16 -08002966 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2967 &sync_blocks, mddev->degraded) &&
NeilBrownab9d47e2011-05-11 14:54:41 +10002968 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
2969 &mddev->recovery)) {
NeilBrown6cce3b22006-01-06 00:20:16 -08002970 /* We can skip this block */
2971 *skipped = 1;
2972 return sync_blocks + sectors_skipped;
2973 }
2974 if (sync_blocks < max_sync)
2975 max_sync = sync_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002976 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
2977
Linus Torvalds1da177e2005-04-16 15:20:36 -07002978 r10_bio->mddev = mddev;
2979 atomic_set(&r10_bio->remaining, 0);
NeilBrown6cce3b22006-01-06 00:20:16 -08002980 raise_barrier(conf, 0);
2981 conf->next_resync = sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002982
2983 r10_bio->master_bio = NULL;
2984 r10_bio->sector = sector_nr;
2985 set_bit(R10BIO_IsSync, &r10_bio->state);
2986 raid10_find_phys(conf, r10_bio);
2987 r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
2988
2989 for (i=0; i<conf->copies; i++) {
2990 int d = r10_bio->devs[i].devnum;
NeilBrown40c356c2011-07-28 11:39:24 +10002991 sector_t first_bad, sector;
2992 int bad_sectors;
2993
NeilBrown9ad1aef2011-12-23 10:17:55 +11002994 if (r10_bio->devs[i].repl_bio)
2995 r10_bio->devs[i].repl_bio->bi_end_io = NULL;
2996
Linus Torvalds1da177e2005-04-16 15:20:36 -07002997 bio = r10_bio->devs[i].bio;
2998 bio->bi_end_io = NULL;
NeilBrownaf03b8e2007-06-16 10:16:06 -07002999 clear_bit(BIO_UPTODATE, &bio->bi_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003000 if (conf->mirrors[d].rdev == NULL ||
NeilBrownb2d444d2005-11-08 21:39:31 -08003001 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003002 continue;
NeilBrown40c356c2011-07-28 11:39:24 +10003003 sector = r10_bio->devs[i].addr;
3004 if (is_badblock(conf->mirrors[d].rdev,
3005 sector, max_sync,
3006 &first_bad, &bad_sectors)) {
3007 if (first_bad > sector)
3008 max_sync = first_bad - sector;
3009 else {
3010 bad_sectors -= (sector - first_bad);
3011 if (max_sync > bad_sectors)
3012 max_sync = max_sync;
3013 continue;
3014 }
3015 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003016 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
3017 atomic_inc(&r10_bio->remaining);
3018 bio->bi_next = biolist;
3019 biolist = bio;
3020 bio->bi_private = r10_bio;
3021 bio->bi_end_io = end_sync_read;
NeilBrown802ba062006-12-13 00:34:13 -08003022 bio->bi_rw = READ;
NeilBrown40c356c2011-07-28 11:39:24 +10003023 bio->bi_sector = sector +
Linus Torvalds1da177e2005-04-16 15:20:36 -07003024 conf->mirrors[d].rdev->data_offset;
3025 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
3026 count++;
NeilBrown9ad1aef2011-12-23 10:17:55 +11003027
3028 if (conf->mirrors[d].replacement == NULL ||
3029 test_bit(Faulty,
3030 &conf->mirrors[d].replacement->flags))
3031 continue;
3032
3033 /* Need to set up for writing to the replacement */
3034 bio = r10_bio->devs[i].repl_bio;
3035 clear_bit(BIO_UPTODATE, &bio->bi_flags);
3036
3037 sector = r10_bio->devs[i].addr;
3038 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
3039 bio->bi_next = biolist;
3040 biolist = bio;
3041 bio->bi_private = r10_bio;
3042 bio->bi_end_io = end_sync_write;
3043 bio->bi_rw = WRITE;
3044 bio->bi_sector = sector +
3045 conf->mirrors[d].replacement->data_offset;
3046 bio->bi_bdev = conf->mirrors[d].replacement->bdev;
3047 count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003048 }
3049
3050 if (count < 2) {
3051 for (i=0; i<conf->copies; i++) {
3052 int d = r10_bio->devs[i].devnum;
3053 if (r10_bio->devs[i].bio->bi_end_io)
NeilBrownab9d47e2011-05-11 14:54:41 +10003054 rdev_dec_pending(conf->mirrors[d].rdev,
3055 mddev);
NeilBrown9ad1aef2011-12-23 10:17:55 +11003056 if (r10_bio->devs[i].repl_bio &&
3057 r10_bio->devs[i].repl_bio->bi_end_io)
3058 rdev_dec_pending(
3059 conf->mirrors[d].replacement,
3060 mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003061 }
3062 put_buf(r10_bio);
3063 biolist = NULL;
3064 goto giveup;
3065 }
3066 }
3067
3068 for (bio = biolist; bio ; bio=bio->bi_next) {
3069
3070 bio->bi_flags &= ~(BIO_POOL_MASK - 1);
3071 if (bio->bi_end_io)
3072 bio->bi_flags |= 1 << BIO_UPTODATE;
3073 bio->bi_vcnt = 0;
3074 bio->bi_idx = 0;
3075 bio->bi_phys_segments = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003076 bio->bi_size = 0;
3077 }
3078
3079 nr_sectors = 0;
NeilBrown6cce3b22006-01-06 00:20:16 -08003080 if (sector_nr + max_sync < max_sector)
3081 max_sector = sector_nr + max_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003082 do {
3083 struct page *page;
3084 int len = PAGE_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003085 if (sector_nr + (len>>9) > max_sector)
3086 len = (max_sector - sector_nr) << 9;
3087 if (len == 0)
3088 break;
3089 for (bio= biolist ; bio ; bio=bio->bi_next) {
NeilBrownab9d47e2011-05-11 14:54:41 +10003090 struct bio *bio2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003091 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
NeilBrownab9d47e2011-05-11 14:54:41 +10003092 if (bio_add_page(bio, page, len, 0))
3093 continue;
3094
3095 /* stop here */
3096 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
3097 for (bio2 = biolist;
3098 bio2 && bio2 != bio;
3099 bio2 = bio2->bi_next) {
3100 /* remove last page from this bio */
3101 bio2->bi_vcnt--;
3102 bio2->bi_size -= len;
3103 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003104 }
NeilBrownab9d47e2011-05-11 14:54:41 +10003105 goto bio_full;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003106 }
3107 nr_sectors += len>>9;
3108 sector_nr += len>>9;
3109 } while (biolist->bi_vcnt < RESYNC_PAGES);
3110 bio_full:
3111 r10_bio->sectors = nr_sectors;
3112
3113 while (biolist) {
3114 bio = biolist;
3115 biolist = biolist->bi_next;
3116
3117 bio->bi_next = NULL;
3118 r10_bio = bio->bi_private;
3119 r10_bio->sectors = nr_sectors;
3120
3121 if (bio->bi_end_io == end_sync_read) {
3122 md_sync_acct(bio->bi_bdev, nr_sectors);
3123 generic_make_request(bio);
3124 }
3125 }
3126
NeilBrown57afd892005-06-21 17:17:13 -07003127 if (sectors_skipped)
3128 /* pretend they weren't skipped, it makes
3129 * no important difference in this case
3130 */
3131 md_done_sync(mddev, sectors_skipped, 1);
3132
Linus Torvalds1da177e2005-04-16 15:20:36 -07003133 return sectors_skipped + nr_sectors;
3134 giveup:
3135 /* There is nowhere to write, so all non-sync
NeilBrowne875ece2011-07-28 11:39:24 +10003136 * drives must be failed or in resync, all drives
3137 * have a bad block, so try the next chunk...
Linus Torvalds1da177e2005-04-16 15:20:36 -07003138 */
NeilBrown09b40682009-02-25 13:18:47 +11003139 if (sector_nr + max_sync < max_sector)
3140 max_sector = sector_nr + max_sync;
3141
3142 sectors_skipped += (max_sector - sector_nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003143 chunks_skipped ++;
3144 sector_nr = max_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003145 goto skipped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003146}
3147
Dan Williams80c3a6c2009-03-17 18:10:40 -07003148static sector_t
NeilBrownfd01b882011-10-11 16:47:53 +11003149raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
Dan Williams80c3a6c2009-03-17 18:10:40 -07003150{
3151 sector_t size;
NeilBrowne879a872011-10-11 16:49:02 +11003152 struct r10conf *conf = mddev->private;
Dan Williams80c3a6c2009-03-17 18:10:40 -07003153
3154 if (!raid_disks)
NeilBrown84707f32010-03-16 17:23:35 +11003155 raid_disks = conf->raid_disks;
Dan Williams80c3a6c2009-03-17 18:10:40 -07003156 if (!sectors)
Trela, Maciejdab8b292010-03-08 16:02:45 +11003157 sectors = conf->dev_sectors;
Dan Williams80c3a6c2009-03-17 18:10:40 -07003158
3159 size = sectors >> conf->chunk_shift;
3160 sector_div(size, conf->far_copies);
3161 size = size * raid_disks;
3162 sector_div(size, conf->near_copies);
3163
3164 return size << conf->chunk_shift;
3165}
3166
Trela, Maciejdab8b292010-03-08 16:02:45 +11003167
NeilBrowne879a872011-10-11 16:49:02 +11003168static struct r10conf *setup_conf(struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169{
NeilBrowne879a872011-10-11 16:49:02 +11003170 struct r10conf *conf = NULL;
NeilBrownc93983b2006-06-26 00:27:41 -07003171 int nc, fc, fo;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003172 sector_t stride, size;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003173 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003174
Maciej Trelaf73ea872010-06-16 11:46:29 +01003175 if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
3176 !is_power_of_2(mddev->new_chunk_sectors)) {
NeilBrown128595e2010-05-03 14:47:14 +10003177 printk(KERN_ERR "md/raid10:%s: chunk size must be "
3178 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
3179 mdname(mddev), PAGE_SIZE);
Trela, Maciejdab8b292010-03-08 16:02:45 +11003180 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003181 }
NeilBrown2604b702006-01-06 00:20:36 -08003182
Maciej Trelaf73ea872010-06-16 11:46:29 +01003183 nc = mddev->new_layout & 255;
3184 fc = (mddev->new_layout >> 8) & 255;
3185 fo = mddev->new_layout & (1<<16);
Trela, Maciejdab8b292010-03-08 16:02:45 +11003186
Linus Torvalds1da177e2005-04-16 15:20:36 -07003187 if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
Maciej Trelaf73ea872010-06-16 11:46:29 +01003188 (mddev->new_layout >> 17)) {
NeilBrown128595e2010-05-03 14:47:14 +10003189 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
Maciej Trelaf73ea872010-06-16 11:46:29 +01003190 mdname(mddev), mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191 goto out;
3192 }
Trela, Maciejdab8b292010-03-08 16:02:45 +11003193
3194 err = -ENOMEM;
NeilBrowne879a872011-10-11 16:49:02 +11003195 conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
Trela, Maciejdab8b292010-03-08 16:02:45 +11003196 if (!conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003197 goto out;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003198
NeilBrown4443ae12006-01-06 00:20:28 -08003199 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
Trela, Maciejdab8b292010-03-08 16:02:45 +11003200 GFP_KERNEL);
3201 if (!conf->mirrors)
3202 goto out;
NeilBrown4443ae12006-01-06 00:20:28 -08003203
3204 conf->tmppage = alloc_page(GFP_KERNEL);
3205 if (!conf->tmppage)
Trela, Maciejdab8b292010-03-08 16:02:45 +11003206 goto out;
3207
Linus Torvalds1da177e2005-04-16 15:20:36 -07003208
NeilBrown64a742b2007-02-28 20:11:18 -08003209 conf->raid_disks = mddev->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003210 conf->near_copies = nc;
3211 conf->far_copies = fc;
3212 conf->copies = nc*fc;
NeilBrownc93983b2006-06-26 00:27:41 -07003213 conf->far_offset = fo;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003214 conf->chunk_mask = mddev->new_chunk_sectors - 1;
3215 conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
3216
3217 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
3218 r10bio_pool_free, conf);
3219 if (!conf->r10bio_pool)
3220 goto out;
3221
Andre Noll58c0fed2009-03-31 14:33:13 +11003222 size = mddev->dev_sectors >> conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08003223 sector_div(size, fc);
3224 size = size * conf->raid_disks;
3225 sector_div(size, nc);
3226 /* 'size' is now the number of chunks in the array */
3227 /* calculate "used chunks per device" in 'stride' */
3228 stride = size * conf->copies;
NeilBrownaf03b8e2007-06-16 10:16:06 -07003229
3230 /* We need to round up when dividing by raid_disks to
3231 * get the stride size.
3232 */
3233 stride += conf->raid_disks - 1;
NeilBrown64a742b2007-02-28 20:11:18 -08003234 sector_div(stride, conf->raid_disks);
Trela, Maciejdab8b292010-03-08 16:02:45 +11003235
3236 conf->dev_sectors = stride << conf->chunk_shift;
NeilBrown64a742b2007-02-28 20:11:18 -08003237
NeilBrownc93983b2006-06-26 00:27:41 -07003238 if (fo)
NeilBrown64a742b2007-02-28 20:11:18 -08003239 stride = 1;
3240 else
NeilBrownc93983b2006-06-26 00:27:41 -07003241 sector_div(stride, fc);
NeilBrown64a742b2007-02-28 20:11:18 -08003242 conf->stride = stride << conf->chunk_shift;
3243
Linus Torvalds1da177e2005-04-16 15:20:36 -07003244
Neil Browne7e72bf2008-05-14 16:05:54 -07003245 spin_lock_init(&conf->device_lock);
Trela, Maciejdab8b292010-03-08 16:02:45 +11003246 INIT_LIST_HEAD(&conf->retry_list);
3247
3248 spin_lock_init(&conf->resync_lock);
3249 init_waitqueue_head(&conf->wait_barrier);
3250
3251 conf->thread = md_register_thread(raid10d, mddev, NULL);
3252 if (!conf->thread)
3253 goto out;
3254
Trela, Maciejdab8b292010-03-08 16:02:45 +11003255 conf->mddev = mddev;
3256 return conf;
3257
3258 out:
NeilBrown128595e2010-05-03 14:47:14 +10003259 printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
Trela, Maciejdab8b292010-03-08 16:02:45 +11003260 mdname(mddev));
3261 if (conf) {
3262 if (conf->r10bio_pool)
3263 mempool_destroy(conf->r10bio_pool);
3264 kfree(conf->mirrors);
3265 safe_put_page(conf->tmppage);
3266 kfree(conf);
3267 }
3268 return ERR_PTR(err);
3269}
3270
NeilBrownfd01b882011-10-11 16:47:53 +11003271static int run(struct mddev *mddev)
Trela, Maciejdab8b292010-03-08 16:02:45 +11003272{
NeilBrowne879a872011-10-11 16:49:02 +11003273 struct r10conf *conf;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003274 int i, disk_idx, chunk_size;
NeilBrown0f6d02d2011-10-11 16:48:46 +11003275 struct mirror_info *disk;
NeilBrown3cb03002011-10-11 16:45:26 +11003276 struct md_rdev *rdev;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003277 sector_t size;
3278
3279 /*
3280 * copy the already verified devices into our private RAID10
3281 * bookkeeping area. [whatever we allocate in run(),
3282 * should be freed in stop()]
3283 */
3284
3285 if (mddev->private == NULL) {
3286 conf = setup_conf(mddev);
3287 if (IS_ERR(conf))
3288 return PTR_ERR(conf);
3289 mddev->private = conf;
3290 }
3291 conf = mddev->private;
3292 if (!conf)
3293 goto out;
3294
Trela, Maciejdab8b292010-03-08 16:02:45 +11003295 mddev->thread = conf->thread;
3296 conf->thread = NULL;
3297
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10003298 chunk_size = mddev->chunk_sectors << 9;
3299 blk_queue_io_min(mddev->queue, chunk_size);
3300 if (conf->raid_disks % conf->near_copies)
3301 blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
3302 else
3303 blk_queue_io_opt(mddev->queue, chunk_size *
3304 (conf->raid_disks / conf->near_copies));
3305
NeilBrowndafb20f2012-03-19 12:46:39 +11003306 rdev_for_each(rdev, mddev) {
NeilBrown34b343c2011-07-28 11:31:47 +10003307
Linus Torvalds1da177e2005-04-16 15:20:36 -07003308 disk_idx = rdev->raid_disk;
NeilBrown84707f32010-03-16 17:23:35 +11003309 if (disk_idx >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003310 || disk_idx < 0)
3311 continue;
3312 disk = conf->mirrors + disk_idx;
3313
NeilBrown56a25592011-12-23 10:17:55 +11003314 if (test_bit(Replacement, &rdev->flags)) {
3315 if (disk->replacement)
3316 goto out_free_conf;
3317 disk->replacement = rdev;
3318 } else {
3319 if (disk->rdev)
3320 goto out_free_conf;
3321 disk->rdev = rdev;
3322 }
3323
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10003324 disk_stack_limits(mddev->gendisk, rdev->bdev,
3325 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003326
3327 disk->head_position = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003328 }
NeilBrown6d508242005-09-09 16:24:03 -07003329 /* need to check that every block has at least one working mirror */
NeilBrown700c7212011-07-27 11:00:36 +10003330 if (!enough(conf, -1)) {
NeilBrown128595e2010-05-03 14:47:14 +10003331 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
NeilBrown6d508242005-09-09 16:24:03 -07003332 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003333 goto out_free_conf;
3334 }
3335
3336 mddev->degraded = 0;
3337 for (i = 0; i < conf->raid_disks; i++) {
3338
3339 disk = conf->mirrors + i;
3340
NeilBrown56a25592011-12-23 10:17:55 +11003341 if (!disk->rdev && disk->replacement) {
3342 /* The replacement is all we have - use it */
3343 disk->rdev = disk->replacement;
3344 disk->replacement = NULL;
3345 clear_bit(Replacement, &disk->rdev->flags);
3346 }
3347
NeilBrown5fd6c1d2006-06-26 00:27:40 -07003348 if (!disk->rdev ||
NeilBrown2e333e82006-10-21 10:24:07 -07003349 !test_bit(In_sync, &disk->rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003350 disk->head_position = 0;
3351 mddev->degraded++;
Neil Brown8c2e8702008-06-28 08:30:52 +10003352 if (disk->rdev)
3353 conf->fullsync = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003354 }
NeilBrownd890fa22011-10-26 11:54:39 +11003355 disk->recovery_disabled = mddev->recovery_disabled - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003356 }
3357
Andre Noll8c6ac862009-06-18 08:48:06 +10003358 if (mddev->recovery_cp != MaxSector)
NeilBrown128595e2010-05-03 14:47:14 +10003359 printk(KERN_NOTICE "md/raid10:%s: not clean"
Andre Noll8c6ac862009-06-18 08:48:06 +10003360 " -- starting background reconstruction\n",
3361 mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003362 printk(KERN_INFO
NeilBrown128595e2010-05-03 14:47:14 +10003363 "md/raid10:%s: active with %d out of %d devices\n",
NeilBrown84707f32010-03-16 17:23:35 +11003364 mdname(mddev), conf->raid_disks - mddev->degraded,
3365 conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003366 /*
3367 * Ok, everything is just fine now
3368 */
Trela, Maciejdab8b292010-03-08 16:02:45 +11003369 mddev->dev_sectors = conf->dev_sectors;
3370 size = raid10_size(mddev, 0, 0);
3371 md_set_array_sectors(mddev, size);
3372 mddev->resync_max_sectors = size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003373
NeilBrown0d129222006-10-03 01:15:54 -07003374 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
3375 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -07003376
Linus Torvalds1da177e2005-04-16 15:20:36 -07003377 /* Calculate max read-ahead size.
3378 * We need to readahead at least twice a whole stripe....
3379 * maybe...
3380 */
3381 {
Andre Noll9d8f0362009-06-18 08:45:01 +10003382 int stripe = conf->raid_disks *
3383 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003384 stripe /= conf->near_copies;
3385 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
3386 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
3387 }
3388
NeilBrown050b6612012-03-19 12:46:39 +11003389 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
Martin K. Petersena91a2782011-03-17 11:11:05 +01003390
3391 if (md_integrity_register(mddev))
3392 goto out_free_conf;
3393
Linus Torvalds1da177e2005-04-16 15:20:36 -07003394 return 0;
3395
3396out_free_conf:
NeilBrown01f96c02011-09-21 15:30:20 +10003397 md_unregister_thread(&mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003398 if (conf->r10bio_pool)
3399 mempool_destroy(conf->r10bio_pool);
NeilBrown1345b1d2006-01-06 00:20:40 -08003400 safe_put_page(conf->tmppage);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07003401 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003402 kfree(conf);
3403 mddev->private = NULL;
3404out:
3405 return -EIO;
3406}
3407
NeilBrownfd01b882011-10-11 16:47:53 +11003408static int stop(struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003409{
NeilBrowne879a872011-10-11 16:49:02 +11003410 struct r10conf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003411
NeilBrown409c57f2009-03-31 14:39:39 +11003412 raise_barrier(conf, 0);
3413 lower_barrier(conf);
3414
NeilBrown01f96c02011-09-21 15:30:20 +10003415 md_unregister_thread(&mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003416 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
3417 if (conf->r10bio_pool)
3418 mempool_destroy(conf->r10bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07003419 kfree(conf->mirrors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003420 kfree(conf);
3421 mddev->private = NULL;
3422 return 0;
3423}
3424
NeilBrownfd01b882011-10-11 16:47:53 +11003425static void raid10_quiesce(struct mddev *mddev, int state)
NeilBrown6cce3b22006-01-06 00:20:16 -08003426{
NeilBrowne879a872011-10-11 16:49:02 +11003427 struct r10conf *conf = mddev->private;
NeilBrown6cce3b22006-01-06 00:20:16 -08003428
3429 switch(state) {
3430 case 1:
3431 raise_barrier(conf, 0);
3432 break;
3433 case 0:
3434 lower_barrier(conf);
3435 break;
3436 }
NeilBrown6cce3b22006-01-06 00:20:16 -08003437}
Linus Torvalds1da177e2005-04-16 15:20:36 -07003438
NeilBrown006a09a2012-03-19 12:46:40 +11003439static int raid10_resize(struct mddev *mddev, sector_t sectors)
3440{
3441 /* Resize of 'far' arrays is not supported.
3442 * For 'near' and 'offset' arrays we can set the
3443 * number of sectors used to be an appropriate multiple
3444 * of the chunk size.
3445 * For 'offset', this is far_copies*chunksize.
3446 * For 'near' the multiplier is the LCM of
3447 * near_copies and raid_disks.
3448 * So if far_copies > 1 && !far_offset, fail.
3449 * Else find LCM(raid_disks, near_copy)*far_copies and
3450 * multiply by chunk_size. Then round to this number.
3451 * This is mostly done by raid10_size()
3452 */
3453 struct r10conf *conf = mddev->private;
3454 sector_t oldsize, size;
3455
3456 if (conf->far_copies > 1 && !conf->far_offset)
3457 return -EINVAL;
3458
3459 oldsize = raid10_size(mddev, 0, 0);
3460 size = raid10_size(mddev, sectors, 0);
3461 md_set_array_sectors(mddev, size);
3462 if (mddev->array_sectors > size)
3463 return -EINVAL;
3464 set_capacity(mddev->gendisk, mddev->array_sectors);
3465 revalidate_disk(mddev->gendisk);
3466 if (sectors > mddev->dev_sectors &&
3467 mddev->recovery_cp > oldsize) {
3468 mddev->recovery_cp = oldsize;
3469 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3470 }
3471 mddev->dev_sectors = sectors;
3472 mddev->resync_max_sectors = size;
3473 return 0;
3474}
3475
NeilBrownfd01b882011-10-11 16:47:53 +11003476static void *raid10_takeover_raid0(struct mddev *mddev)
Trela, Maciejdab8b292010-03-08 16:02:45 +11003477{
NeilBrown3cb03002011-10-11 16:45:26 +11003478 struct md_rdev *rdev;
NeilBrowne879a872011-10-11 16:49:02 +11003479 struct r10conf *conf;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003480
3481 if (mddev->degraded > 0) {
NeilBrown128595e2010-05-03 14:47:14 +10003482 printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
3483 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11003484 return ERR_PTR(-EINVAL);
3485 }
3486
Trela, Maciejdab8b292010-03-08 16:02:45 +11003487 /* Set new parameters */
3488 mddev->new_level = 10;
3489 /* new layout: far_copies = 1, near_copies = 2 */
3490 mddev->new_layout = (1<<8) + 2;
3491 mddev->new_chunk_sectors = mddev->chunk_sectors;
3492 mddev->delta_disks = mddev->raid_disks;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003493 mddev->raid_disks *= 2;
3494 /* make sure it will be not marked as dirty */
3495 mddev->recovery_cp = MaxSector;
3496
3497 conf = setup_conf(mddev);
Krzysztof Wojcik02214dc2011-02-04 14:18:26 +01003498 if (!IS_ERR(conf)) {
NeilBrowndafb20f2012-03-19 12:46:39 +11003499 rdev_for_each(rdev, mddev)
NeilBrowne93f68a2010-06-15 09:36:03 +01003500 if (rdev->raid_disk >= 0)
3501 rdev->new_raid_disk = rdev->raid_disk * 2;
Krzysztof Wojcik02214dc2011-02-04 14:18:26 +01003502 conf->barrier = 1;
3503 }
3504
Trela, Maciejdab8b292010-03-08 16:02:45 +11003505 return conf;
3506}
3507
NeilBrownfd01b882011-10-11 16:47:53 +11003508static void *raid10_takeover(struct mddev *mddev)
Trela, Maciejdab8b292010-03-08 16:02:45 +11003509{
NeilBrowne373ab12011-10-11 16:48:59 +11003510 struct r0conf *raid0_conf;
Trela, Maciejdab8b292010-03-08 16:02:45 +11003511
3512 /* raid10 can take over:
3513 * raid0 - providing it has only two drives
3514 */
3515 if (mddev->level == 0) {
3516 /* for raid0 takeover only one zone is supported */
NeilBrowne373ab12011-10-11 16:48:59 +11003517 raid0_conf = mddev->private;
3518 if (raid0_conf->nr_strip_zones > 1) {
NeilBrown128595e2010-05-03 14:47:14 +10003519 printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
3520 " with more than one zone.\n",
3521 mdname(mddev));
Trela, Maciejdab8b292010-03-08 16:02:45 +11003522 return ERR_PTR(-EINVAL);
3523 }
3524 return raid10_takeover_raid0(mddev);
3525 }
3526 return ERR_PTR(-EINVAL);
3527}
3528
NeilBrown84fc4b52011-10-11 16:49:58 +11003529static struct md_personality raid10_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530{
3531 .name = "raid10",
NeilBrown2604b702006-01-06 00:20:36 -08003532 .level = 10,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003533 .owner = THIS_MODULE,
3534 .make_request = make_request,
3535 .run = run,
3536 .stop = stop,
3537 .status = status,
3538 .error_handler = error,
3539 .hot_add_disk = raid10_add_disk,
3540 .hot_remove_disk= raid10_remove_disk,
3541 .spare_active = raid10_spare_active,
3542 .sync_request = sync_request,
NeilBrown6cce3b22006-01-06 00:20:16 -08003543 .quiesce = raid10_quiesce,
Dan Williams80c3a6c2009-03-17 18:10:40 -07003544 .size = raid10_size,
NeilBrown006a09a2012-03-19 12:46:40 +11003545 .resize = raid10_resize,
Trela, Maciejdab8b292010-03-08 16:02:45 +11003546 .takeover = raid10_takeover,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003547};
3548
3549static int __init raid_init(void)
3550{
NeilBrown2604b702006-01-06 00:20:36 -08003551 return register_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003552}
3553
3554static void raid_exit(void)
3555{
NeilBrown2604b702006-01-06 00:20:36 -08003556 unregister_md_personality(&raid10_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003557}
3558
3559module_init(raid_init);
3560module_exit(raid_exit);
3561MODULE_LICENSE("GPL");
NeilBrown0efb9e62009-12-14 12:49:58 +11003562MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003563MODULE_ALIAS("md-personality-9"); /* RAID10 */
NeilBrownd9d166c2006-01-06 00:20:51 -08003564MODULE_ALIAS("md-raid10");
NeilBrown2604b702006-01-06 00:20:36 -08003565MODULE_ALIAS("md-level-10");
NeilBrown34db0cd2011-10-11 16:50:01 +11003566
3567module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);