blob: 97ee870b265d866ffa818bdf83dc7f551cd40d7b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
NeilBrown191ea9b2005-06-21 17:17:23 -070015 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
NeilBrown191ea9b2005-06-21 17:17:23 -070034#include "dm-bio-list.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/raid/raid1.h>
NeilBrown191ea9b2005-06-21 17:17:23 -070036#include <linux/raid/bitmap.h>
37
38#define DEBUG 0
39#if DEBUG
40#define PRINTK(x...) printk(x)
41#else
42#define PRINTK(x...)
43#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45/*
46 * Number of guaranteed r1bios in case of extreme VM load:
47 */
48#define NR_RAID1_BIOS 256
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51static void unplug_slaves(mddev_t *mddev);
52
NeilBrown17999be2006-01-06 00:20:12 -080053static void allow_barrier(conf_t *conf);
54static void lower_barrier(conf_t *conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Al Virodd0fc662005-10-07 07:46:04 +010056static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
58 struct pool_info *pi = data;
59 r1bio_t *r1_bio;
60 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
61
62 /* allocate a r1bio with room for raid_disks entries in the bios array */
NeilBrown9ffae0c2006-01-06 00:20:32 -080063 r1_bio = kzalloc(size, gfp_flags);
64 if (!r1_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 unplug_slaves(pi->mddev);
66
67 return r1_bio;
68}
69
70static void r1bio_pool_free(void *r1_bio, void *data)
71{
72 kfree(r1_bio);
73}
74
75#define RESYNC_BLOCK_SIZE (64*1024)
76//#define RESYNC_BLOCK_SIZE PAGE_SIZE
77#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
78#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
79#define RESYNC_WINDOW (2048*1024)
80
Al Virodd0fc662005-10-07 07:46:04 +010081static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082{
83 struct pool_info *pi = data;
84 struct page *page;
85 r1bio_t *r1_bio;
86 struct bio *bio;
87 int i, j;
88
89 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
90 if (!r1_bio) {
91 unplug_slaves(pi->mddev);
92 return NULL;
93 }
94
95 /*
96 * Allocate bios : 1 for reading, n-1 for writing
97 */
98 for (j = pi->raid_disks ; j-- ; ) {
99 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
100 if (!bio)
101 goto out_free_bio;
102 r1_bio->bios[j] = bio;
103 }
104 /*
105 * Allocate RESYNC_PAGES data pages and attach them to
NeilBrownd11c1712006-01-06 00:20:26 -0800106 * the first bio.
107 * If this is a user-requested check/repair, allocate
108 * RESYNC_PAGES for each bio.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 */
NeilBrownd11c1712006-01-06 00:20:26 -0800110 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
111 j = pi->raid_disks;
112 else
113 j = 1;
114 while(j--) {
115 bio = r1_bio->bios[j];
116 for (i = 0; i < RESYNC_PAGES; i++) {
117 page = alloc_page(gfp_flags);
118 if (unlikely(!page))
119 goto out_free_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
NeilBrownd11c1712006-01-06 00:20:26 -0800121 bio->bi_io_vec[i].bv_page = page;
122 }
123 }
124 /* If not user-requests, copy the page pointers to all bios */
125 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
126 for (i=0; i<RESYNC_PAGES ; i++)
127 for (j=1; j<pi->raid_disks; j++)
128 r1_bio->bios[j]->bi_io_vec[i].bv_page =
129 r1_bio->bios[0]->bi_io_vec[i].bv_page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 }
131
132 r1_bio->master_bio = NULL;
133
134 return r1_bio;
135
136out_free_pages:
NeilBrownd11c1712006-01-06 00:20:26 -0800137 for (i=0; i < RESYNC_PAGES ; i++)
138 for (j=0 ; j < pi->raid_disks; j++)
NeilBrown1345b1d2006-01-06 00:20:40 -0800139 safe_put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
NeilBrownd11c1712006-01-06 00:20:26 -0800140 j = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141out_free_bio:
142 while ( ++j < pi->raid_disks )
143 bio_put(r1_bio->bios[j]);
144 r1bio_pool_free(r1_bio, data);
145 return NULL;
146}
147
148static void r1buf_pool_free(void *__r1_bio, void *data)
149{
150 struct pool_info *pi = data;
NeilBrownd11c1712006-01-06 00:20:26 -0800151 int i,j;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 r1bio_t *r1bio = __r1_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
NeilBrownd11c1712006-01-06 00:20:26 -0800154 for (i = 0; i < RESYNC_PAGES; i++)
155 for (j = pi->raid_disks; j-- ;) {
156 if (j == 0 ||
157 r1bio->bios[j]->bi_io_vec[i].bv_page !=
158 r1bio->bios[0]->bi_io_vec[i].bv_page)
NeilBrown1345b1d2006-01-06 00:20:40 -0800159 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
NeilBrownd11c1712006-01-06 00:20:26 -0800160 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 for (i=0 ; i < pi->raid_disks; i++)
162 bio_put(r1bio->bios[i]);
163
164 r1bio_pool_free(r1bio, data);
165}
166
167static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
168{
169 int i;
170
171 for (i = 0; i < conf->raid_disks; i++) {
172 struct bio **bio = r1_bio->bios + i;
NeilBrowncf30a472006-01-06 00:20:23 -0800173 if (*bio && *bio != IO_BLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 bio_put(*bio);
175 *bio = NULL;
176 }
177}
178
Arjan van de Ven858119e2006-01-14 13:20:43 -0800179static void free_r1bio(r1bio_t *r1_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 conf_t *conf = mddev_to_conf(r1_bio->mddev);
182
183 /*
184 * Wake up any possible resync thread that waits for the device
185 * to go idle.
186 */
NeilBrown17999be2006-01-06 00:20:12 -0800187 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 put_all_bios(conf, r1_bio);
190 mempool_free(r1_bio, conf->r1bio_pool);
191}
192
Arjan van de Ven858119e2006-01-14 13:20:43 -0800193static void put_buf(r1bio_t *r1_bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
195 conf_t *conf = mddev_to_conf(r1_bio->mddev);
NeilBrown3e198f72006-01-06 00:20:21 -0800196 int i;
197
198 for (i=0; i<conf->raid_disks; i++) {
199 struct bio *bio = r1_bio->bios[i];
200 if (bio->bi_end_io)
201 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
202 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 mempool_free(r1_bio, conf->r1buf_pool);
205
NeilBrown17999be2006-01-06 00:20:12 -0800206 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207}
208
209static void reschedule_retry(r1bio_t *r1_bio)
210{
211 unsigned long flags;
212 mddev_t *mddev = r1_bio->mddev;
213 conf_t *conf = mddev_to_conf(mddev);
214
215 spin_lock_irqsave(&conf->device_lock, flags);
216 list_add(&r1_bio->retry_list, &conf->retry_list);
NeilBrownddaf22a2006-01-06 00:20:19 -0800217 conf->nr_queued ++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 spin_unlock_irqrestore(&conf->device_lock, flags);
219
NeilBrown17999be2006-01-06 00:20:12 -0800220 wake_up(&conf->wait_barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 md_wakeup_thread(mddev->thread);
222}
223
224/*
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
227 * cache layer.
228 */
229static void raid_end_bio_io(r1bio_t *r1_bio)
230{
231 struct bio *bio = r1_bio->master_bio;
232
NeilBrown4b6d2872005-09-09 16:23:47 -0700233 /* if nobody has done the final endio yet, do it now */
234 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
235 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
236 (bio_data_dir(bio) == WRITE) ? "write" : "read",
237 (unsigned long long) bio->bi_sector,
238 (unsigned long long) bio->bi_sector +
239 (bio->bi_size >> 9) - 1);
240
241 bio_endio(bio, bio->bi_size,
242 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
243 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 free_r1bio(r1_bio);
245}
246
247/*
248 * Update disk head position estimator based on IRQ completion info.
249 */
250static inline void update_head_pos(int disk, r1bio_t *r1_bio)
251{
252 conf_t *conf = mddev_to_conf(r1_bio->mddev);
253
254 conf->mirrors[disk].head_position =
255 r1_bio->sector + (r1_bio->sectors);
256}
257
258static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
259{
260 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
261 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
262 int mirror;
263 conf_t *conf = mddev_to_conf(r1_bio->mddev);
264
265 if (bio->bi_size)
266 return 1;
267
268 mirror = r1_bio->read_disk;
269 /*
270 * this branch is our 'one mirror IO has finished' event handler:
271 */
NeilBrownddaf22a2006-01-06 00:20:19 -0800272 update_head_pos(mirror, r1_bio);
273
NeilBrown11ce99e2006-10-03 01:15:52 -0700274 if (uptodate || (conf->raid_disks - conf->mddev->degraded) <= 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 /*
276 * Set R1BIO_Uptodate in our master bio, so that
277 * we will return a good error code for to the higher
278 * levels even if IO on some other mirrored buffer fails.
279 *
280 * The 'master' represents the composite IO operation to
281 * user-side. So if something waits for IO, then it will
282 * wait for the 'master' bio.
283 */
NeilBrown220946c2006-01-06 00:20:27 -0800284 if (uptodate)
285 set_bit(R1BIO_Uptodate, &r1_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 raid_end_bio_io(r1_bio);
NeilBrownddaf22a2006-01-06 00:20:19 -0800288 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 /*
290 * oops, read error:
291 */
292 char b[BDEVNAME_SIZE];
293 if (printk_ratelimit())
294 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
295 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
296 reschedule_retry(r1_bio);
297 }
298
299 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
300 return 0;
301}
302
303static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
304{
305 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
306 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
NeilBrowna9701a32005-11-08 21:39:34 -0800307 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 conf_t *conf = mddev_to_conf(r1_bio->mddev);
NeilBrown04b857f2006-03-09 17:33:46 -0800309 struct bio *to_put = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
311 if (bio->bi_size)
312 return 1;
313
314 for (mirror = 0; mirror < conf->raid_disks; mirror++)
315 if (r1_bio->bios[mirror] == bio)
316 break;
317
NeilBrownbea27712006-05-01 12:15:46 -0700318 if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
NeilBrowna9701a32005-11-08 21:39:34 -0800319 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
320 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
321 r1_bio->mddev->barriers_work = 0;
NeilBrown5e7dd2a2006-05-01 12:15:47 -0700322 /* Don't rdev_dec_pending in this branch - keep it for the retry */
NeilBrowna9701a32005-11-08 21:39:34 -0800323 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 /*
NeilBrowna9701a32005-11-08 21:39:34 -0800325 * this branch is our 'one mirror IO has finished' event handler:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 */
NeilBrowna9701a32005-11-08 21:39:34 -0800327 r1_bio->bios[mirror] = NULL;
NeilBrown04b857f2006-03-09 17:33:46 -0800328 to_put = bio;
NeilBrowna9701a32005-11-08 21:39:34 -0800329 if (!uptodate) {
330 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
331 /* an I/O failed, we can't clear the bitmap */
332 set_bit(R1BIO_Degraded, &r1_bio->state);
333 } else
334 /*
335 * Set R1BIO_Uptodate in our master bio, so that
336 * we will return a good error code for to the higher
337 * levels even if IO on some other mirrored buffer fails.
338 *
339 * The 'master' represents the composite IO operation to
340 * user-side. So if something waits for IO, then it will
341 * wait for the 'master' bio.
342 */
343 set_bit(R1BIO_Uptodate, &r1_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
NeilBrowna9701a32005-11-08 21:39:34 -0800345 update_head_pos(mirror, r1_bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
NeilBrowna9701a32005-11-08 21:39:34 -0800347 if (behind) {
348 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
349 atomic_dec(&r1_bio->behind_remaining);
NeilBrown4b6d2872005-09-09 16:23:47 -0700350
NeilBrowna9701a32005-11-08 21:39:34 -0800351 /* In behind mode, we ACK the master bio once the I/O has safely
352 * reached all non-writemostly disks. Setting the Returned bit
353 * ensures that this gets done only once -- we don't ever want to
354 * return -EIO here, instead we'll wait */
NeilBrown4b6d2872005-09-09 16:23:47 -0700355
NeilBrowna9701a32005-11-08 21:39:34 -0800356 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
357 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
358 /* Maybe we can return now */
359 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
360 struct bio *mbio = r1_bio->master_bio;
361 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
362 (unsigned long long) mbio->bi_sector,
363 (unsigned long long) mbio->bi_sector +
364 (mbio->bi_size >> 9) - 1);
365 bio_endio(mbio, mbio->bi_size, 0);
366 }
NeilBrown4b6d2872005-09-09 16:23:47 -0700367 }
368 }
NeilBrown5e7dd2a2006-05-01 12:15:47 -0700369 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
NeilBrown4b6d2872005-09-09 16:23:47 -0700370 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 /*
372 *
373 * Let's see if all mirrored write operations have finished
374 * already.
375 */
376 if (atomic_dec_and_test(&r1_bio->remaining)) {
NeilBrownc70810b2006-06-26 00:27:35 -0700377 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
NeilBrowna9701a32005-11-08 21:39:34 -0800378 reschedule_retry(r1_bio);
NeilBrownc70810b2006-06-26 00:27:35 -0700379 else {
380 /* it really is the end of this request */
381 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
382 /* free extra copy of the data pages */
383 int i = bio->bi_vcnt;
384 while (i--)
385 safe_put_page(bio->bi_io_vec[i].bv_page);
386 }
387 /* clear the bitmap if all writes complete successfully */
388 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
389 r1_bio->sectors,
390 !test_bit(R1BIO_Degraded, &r1_bio->state),
391 behind);
392 md_write_end(r1_bio->mddev);
393 raid_end_bio_io(r1_bio);
NeilBrowna9701a32005-11-08 21:39:34 -0800394 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 }
NeilBrownc70810b2006-06-26 00:27:35 -0700396
NeilBrown04b857f2006-03-09 17:33:46 -0800397 if (to_put)
398 bio_put(to_put);
399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 return 0;
401}
402
403
404/*
405 * This routine returns the disk from which the requested read should
406 * be done. There is a per-array 'next expected sequential IO' sector
407 * number - if this matches on the next IO then we use the last disk.
408 * There is also a per-disk 'last know head position' sector that is
409 * maintained from IRQ contexts, both the normal and the resync IO
410 * completion handlers update this position correctly. If there is no
411 * perfect sequential match then we pick the disk whose head is closest.
412 *
413 * If there are 2 mirrors in the same 2 devices, performance degrades
414 * because position is mirror, not device based.
415 *
416 * The rdev for the device selected will have nr_pending incremented.
417 */
418static int read_balance(conf_t *conf, r1bio_t *r1_bio)
419{
420 const unsigned long this_sector = r1_bio->sector;
421 int new_disk = conf->last_used, disk = new_disk;
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700422 int wonly_disk = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 const int sectors = r1_bio->sectors;
424 sector_t new_distance, current_distance;
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700425 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 rcu_read_lock();
428 /*
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700429 * Check if we can balance. We can balance on the whole
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 * device if no resync is going on, or below the resync window.
431 * We take the first readable disk when above the resync window.
432 */
433 retry:
434 if (conf->mddev->recovery_cp < MaxSector &&
435 (this_sector + sectors >= conf->next_resync)) {
436 /* Choose the first operation device, for consistancy */
437 new_disk = 0;
438
Suzanne Woodd6065f72005-11-08 21:39:27 -0800439 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
NeilBrowncf30a472006-01-06 00:20:23 -0800440 r1_bio->bios[new_disk] == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800441 !rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700442 || test_bit(WriteMostly, &rdev->flags);
Suzanne Woodd6065f72005-11-08 21:39:27 -0800443 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700444
NeilBrowncf30a472006-01-06 00:20:23 -0800445 if (rdev && test_bit(In_sync, &rdev->flags) &&
446 r1_bio->bios[new_disk] != IO_BLOCKED)
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700447 wonly_disk = new_disk;
448
449 if (new_disk == conf->raid_disks - 1) {
450 new_disk = wonly_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 break;
452 }
453 }
454 goto rb_out;
455 }
456
457
458 /* make sure the disk is operational */
Suzanne Woodd6065f72005-11-08 21:39:27 -0800459 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
NeilBrowncf30a472006-01-06 00:20:23 -0800460 r1_bio->bios[new_disk] == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800461 !rdev || !test_bit(In_sync, &rdev->flags) ||
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700462 test_bit(WriteMostly, &rdev->flags);
Suzanne Woodd6065f72005-11-08 21:39:27 -0800463 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700464
NeilBrowncf30a472006-01-06 00:20:23 -0800465 if (rdev && test_bit(In_sync, &rdev->flags) &&
466 r1_bio->bios[new_disk] != IO_BLOCKED)
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700467 wonly_disk = new_disk;
468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 if (new_disk <= 0)
470 new_disk = conf->raid_disks;
471 new_disk--;
472 if (new_disk == disk) {
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700473 new_disk = wonly_disk;
474 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 }
476 }
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700477
478 if (new_disk < 0)
479 goto rb_out;
480
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 disk = new_disk;
482 /* now disk == new_disk == starting point for search */
483
484 /*
485 * Don't change to another disk for sequential reads:
486 */
487 if (conf->next_seq_sect == this_sector)
488 goto rb_out;
489 if (this_sector == conf->mirrors[new_disk].head_position)
490 goto rb_out;
491
492 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
493
494 /* Find the disk whose head is closest */
495
496 do {
497 if (disk <= 0)
498 disk = conf->raid_disks;
499 disk--;
500
Suzanne Woodd6065f72005-11-08 21:39:27 -0800501 rdev = rcu_dereference(conf->mirrors[disk].rdev);
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700502
NeilBrowncf30a472006-01-06 00:20:23 -0800503 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
NeilBrownb2d444d2005-11-08 21:39:31 -0800504 !test_bit(In_sync, &rdev->flags) ||
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700505 test_bit(WriteMostly, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 continue;
507
508 if (!atomic_read(&rdev->nr_pending)) {
509 new_disk = disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 break;
511 }
512 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
513 if (new_distance < current_distance) {
514 current_distance = new_distance;
515 new_disk = disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 }
517 } while (disk != conf->last_used);
518
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700519 rb_out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
521
522 if (new_disk >= 0) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800523 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700524 if (!rdev)
525 goto retry;
526 atomic_inc(&rdev->nr_pending);
NeilBrownb2d444d2005-11-08 21:39:31 -0800527 if (!test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 /* cannot risk returning a device that failed
529 * before we inc'ed nr_pending
530 */
NeilBrown03c902e2006-01-06 00:20:46 -0800531 rdev_dec_pending(rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 goto retry;
533 }
NeilBrown8ddf9ef2005-09-09 16:23:45 -0700534 conf->next_seq_sect = this_sector + sectors;
535 conf->last_used = new_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 }
537 rcu_read_unlock();
538
539 return new_disk;
540}
541
542static void unplug_slaves(mddev_t *mddev)
543{
544 conf_t *conf = mddev_to_conf(mddev);
545 int i;
546
547 rcu_read_lock();
548 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800549 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800550 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
552
553 atomic_inc(&rdev->nr_pending);
554 rcu_read_unlock();
555
556 if (r_queue->unplug_fn)
557 r_queue->unplug_fn(r_queue);
558
559 rdev_dec_pending(rdev, mddev);
560 rcu_read_lock();
561 }
562 }
563 rcu_read_unlock();
564}
565
566static void raid1_unplug(request_queue_t *q)
567{
NeilBrown191ea9b2005-06-21 17:17:23 -0700568 mddev_t *mddev = q->queuedata;
569
570 unplug_slaves(mddev);
571 md_wakeup_thread(mddev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572}
573
574static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
575 sector_t *error_sector)
576{
577 mddev_t *mddev = q->queuedata;
578 conf_t *conf = mddev_to_conf(mddev);
579 int i, ret = 0;
580
581 rcu_read_lock();
582 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800583 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800584 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 struct block_device *bdev = rdev->bdev;
586 request_queue_t *r_queue = bdev_get_queue(bdev);
587
588 if (!r_queue->issue_flush_fn)
589 ret = -EOPNOTSUPP;
590 else {
591 atomic_inc(&rdev->nr_pending);
592 rcu_read_unlock();
593 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
594 error_sector);
595 rdev_dec_pending(rdev, mddev);
596 rcu_read_lock();
597 }
598 }
599 }
600 rcu_read_unlock();
601 return ret;
602}
603
NeilBrown0d129222006-10-03 01:15:54 -0700604static int raid1_congested(void *data, int bits)
605{
606 mddev_t *mddev = data;
607 conf_t *conf = mddev_to_conf(mddev);
608 int i, ret = 0;
609
610 rcu_read_lock();
611 for (i = 0; i < mddev->raid_disks; i++) {
612 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
613 if (rdev && !test_bit(Faulty, &rdev->flags)) {
614 request_queue_t *q = bdev_get_queue(rdev->bdev);
615
616 /* Note the '|| 1' - when read_balance prefers
617 * non-congested targets, it can be removed
618 */
619 if ((bits & (1<<BDI_write_congested)) || 1)
620 ret |= bdi_congested(&q->backing_dev_info, bits);
621 else
622 ret &= bdi_congested(&q->backing_dev_info, bits);
623 }
624 }
625 rcu_read_unlock();
626 return ret;
627}
628
629
NeilBrown17999be2006-01-06 00:20:12 -0800630/* Barriers....
631 * Sometimes we need to suspend IO while we do something else,
632 * either some resync/recovery, or reconfigure the array.
633 * To do this we raise a 'barrier'.
634 * The 'barrier' is a counter that can be raised multiple times
635 * to count how many activities are happening which preclude
636 * normal IO.
637 * We can only raise the barrier if there is no pending IO.
638 * i.e. if nr_pending == 0.
639 * We choose only to raise the barrier if no-one is waiting for the
640 * barrier to go down. This means that as soon as an IO request
641 * is ready, no other operations which require a barrier will start
642 * until the IO request has had a chance.
643 *
644 * So: regular IO calls 'wait_barrier'. When that returns there
645 * is no backgroup IO happening, It must arrange to call
646 * allow_barrier when it has finished its IO.
647 * backgroup IO calls must call raise_barrier. Once that returns
648 * there is no normal IO happeing. It must arrange to call
649 * lower_barrier when the particular background IO completes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 */
651#define RESYNC_DEPTH 32
652
NeilBrown17999be2006-01-06 00:20:12 -0800653static void raise_barrier(conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
655 spin_lock_irq(&conf->resync_lock);
NeilBrown17999be2006-01-06 00:20:12 -0800656
657 /* Wait until no block IO is waiting */
658 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
659 conf->resync_lock,
660 raid1_unplug(conf->mddev->queue));
661
662 /* block any new IO from starting */
663 conf->barrier++;
664
665 /* No wait for all pending IO to complete */
666 wait_event_lock_irq(conf->wait_barrier,
667 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
668 conf->resync_lock,
669 raid1_unplug(conf->mddev->queue));
670
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 spin_unlock_irq(&conf->resync_lock);
672}
673
NeilBrown17999be2006-01-06 00:20:12 -0800674static void lower_barrier(conf_t *conf)
675{
676 unsigned long flags;
677 spin_lock_irqsave(&conf->resync_lock, flags);
678 conf->barrier--;
679 spin_unlock_irqrestore(&conf->resync_lock, flags);
680 wake_up(&conf->wait_barrier);
681}
682
683static void wait_barrier(conf_t *conf)
684{
685 spin_lock_irq(&conf->resync_lock);
686 if (conf->barrier) {
687 conf->nr_waiting++;
688 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
689 conf->resync_lock,
690 raid1_unplug(conf->mddev->queue));
691 conf->nr_waiting--;
692 }
693 conf->nr_pending++;
694 spin_unlock_irq(&conf->resync_lock);
695}
696
697static void allow_barrier(conf_t *conf)
698{
699 unsigned long flags;
700 spin_lock_irqsave(&conf->resync_lock, flags);
701 conf->nr_pending--;
702 spin_unlock_irqrestore(&conf->resync_lock, flags);
703 wake_up(&conf->wait_barrier);
704}
705
NeilBrownddaf22a2006-01-06 00:20:19 -0800706static void freeze_array(conf_t *conf)
707{
708 /* stop syncio and normal IO and wait for everything to
709 * go quite.
710 * We increment barrier and nr_waiting, and then
711 * wait until barrier+nr_pending match nr_queued+2
712 */
713 spin_lock_irq(&conf->resync_lock);
714 conf->barrier++;
715 conf->nr_waiting++;
716 wait_event_lock_irq(conf->wait_barrier,
717 conf->barrier+conf->nr_pending == conf->nr_queued+2,
718 conf->resync_lock,
719 raid1_unplug(conf->mddev->queue));
720 spin_unlock_irq(&conf->resync_lock);
721}
722static void unfreeze_array(conf_t *conf)
723{
724 /* reverse the effect of the freeze */
725 spin_lock_irq(&conf->resync_lock);
726 conf->barrier--;
727 conf->nr_waiting--;
728 wake_up(&conf->wait_barrier);
729 spin_unlock_irq(&conf->resync_lock);
730}
731
NeilBrown17999be2006-01-06 00:20:12 -0800732
NeilBrown4b6d2872005-09-09 16:23:47 -0700733/* duplicate the data pages for behind I/O */
734static struct page **alloc_behind_pages(struct bio *bio)
735{
736 int i;
737 struct bio_vec *bvec;
NeilBrown9ffae0c2006-01-06 00:20:32 -0800738 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
NeilBrown4b6d2872005-09-09 16:23:47 -0700739 GFP_NOIO);
740 if (unlikely(!pages))
741 goto do_sync_io;
742
NeilBrown4b6d2872005-09-09 16:23:47 -0700743 bio_for_each_segment(bvec, bio, i) {
744 pages[i] = alloc_page(GFP_NOIO);
745 if (unlikely(!pages[i]))
746 goto do_sync_io;
747 memcpy(kmap(pages[i]) + bvec->bv_offset,
748 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
749 kunmap(pages[i]);
750 kunmap(bvec->bv_page);
751 }
752
753 return pages;
754
755do_sync_io:
756 if (pages)
757 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
NeilBrown2d1f3b52006-01-06 00:20:31 -0800758 put_page(pages[i]);
NeilBrown4b6d2872005-09-09 16:23:47 -0700759 kfree(pages);
760 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
761 return NULL;
762}
763
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764static int make_request(request_queue_t *q, struct bio * bio)
765{
766 mddev_t *mddev = q->queuedata;
767 conf_t *conf = mddev_to_conf(mddev);
768 mirror_info_t *mirror;
769 r1bio_t *r1_bio;
770 struct bio *read_bio;
NeilBrown191ea9b2005-06-21 17:17:23 -0700771 int i, targets = 0, disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 mdk_rdev_t *rdev;
NeilBrown191ea9b2005-06-21 17:17:23 -0700773 struct bitmap *bitmap = mddev->bitmap;
774 unsigned long flags;
775 struct bio_list bl;
NeilBrown4b6d2872005-09-09 16:23:47 -0700776 struct page **behind_pages = NULL;
Jens Axboea3623572005-11-01 09:26:16 +0100777 const int rw = bio_data_dir(bio);
Lars Ellenberge3881a62007-01-10 23:15:37 -0800778 const int do_sync = bio_sync(bio);
NeilBrowna9701a32005-11-08 21:39:34 -0800779 int do_barriers;
NeilBrown191ea9b2005-06-21 17:17:23 -0700780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 /*
782 * Register the new request and wait if the reconstruction
783 * thread has put up a bar for new requests.
784 * Continue immediately if no resync is active currently.
NeilBrown62de6082006-05-01 12:15:47 -0700785 * We test barriers_work *after* md_write_start as md_write_start
786 * may cause the first superblock write, and that will check out
787 * if barriers work.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 */
NeilBrown62de6082006-05-01 12:15:47 -0700789
NeilBrown3d310eb2005-06-21 17:17:26 -0700790 md_write_start(mddev, bio); /* wait on superblock update early */
791
NeilBrown62de6082006-05-01 12:15:47 -0700792 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
793 if (rw == WRITE)
794 md_write_end(mddev);
795 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
796 return 0;
797 }
798
NeilBrown17999be2006-01-06 00:20:12 -0800799 wait_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
Jens Axboea3623572005-11-01 09:26:16 +0100801 disk_stat_inc(mddev->gendisk, ios[rw]);
802 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
804 /*
805 * make_request() can abort the operation when READA is being
806 * used and no empty request is available.
807 *
808 */
809 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
810
811 r1_bio->master_bio = bio;
812 r1_bio->sectors = bio->bi_size >> 9;
NeilBrown191ea9b2005-06-21 17:17:23 -0700813 r1_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 r1_bio->mddev = mddev;
815 r1_bio->sector = bio->bi_sector;
816
Jens Axboea3623572005-11-01 09:26:16 +0100817 if (rw == READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 /*
819 * read balancing logic:
820 */
821 int rdisk = read_balance(conf, r1_bio);
822
823 if (rdisk < 0) {
824 /* couldn't find anywhere to read from */
825 raid_end_bio_io(r1_bio);
826 return 0;
827 }
828 mirror = conf->mirrors + rdisk;
829
830 r1_bio->read_disk = rdisk;
831
832 read_bio = bio_clone(bio, GFP_NOIO);
833
834 r1_bio->bios[rdisk] = read_bio;
835
836 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
837 read_bio->bi_bdev = mirror->rdev->bdev;
838 read_bio->bi_end_io = raid1_end_read_request;
Lars Ellenberge3881a62007-01-10 23:15:37 -0800839 read_bio->bi_rw = READ | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 read_bio->bi_private = r1_bio;
841
842 generic_make_request(read_bio);
843 return 0;
844 }
845
846 /*
847 * WRITE:
848 */
849 /* first select target devices under spinlock and
850 * inc refcount on their rdev. Record them by setting
851 * bios[x] to bio
852 */
853 disks = conf->raid_disks;
NeilBrown191ea9b2005-06-21 17:17:23 -0700854#if 0
855 { static int first=1;
856 if (first) printk("First Write sector %llu disks %d\n",
857 (unsigned long long)r1_bio->sector, disks);
858 first = 0;
859 }
860#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 rcu_read_lock();
862 for (i = 0; i < disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800863 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800864 !test_bit(Faulty, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 atomic_inc(&rdev->nr_pending);
NeilBrownb2d444d2005-11-08 21:39:31 -0800866 if (test_bit(Faulty, &rdev->flags)) {
NeilBrown03c902e2006-01-06 00:20:46 -0800867 rdev_dec_pending(rdev, mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 r1_bio->bios[i] = NULL;
869 } else
870 r1_bio->bios[i] = bio;
NeilBrown191ea9b2005-06-21 17:17:23 -0700871 targets++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 } else
873 r1_bio->bios[i] = NULL;
874 }
875 rcu_read_unlock();
876
NeilBrown4b6d2872005-09-09 16:23:47 -0700877 BUG_ON(targets == 0); /* we never fail the last device */
878
NeilBrown191ea9b2005-06-21 17:17:23 -0700879 if (targets < conf->raid_disks) {
880 /* array is degraded, we will not clear the bitmap
881 * on I/O completion (see raid1_end_write_request) */
882 set_bit(R1BIO_Degraded, &r1_bio->state);
883 }
NeilBrown06d91a52005-06-21 17:17:12 -0700884
NeilBrown4b6d2872005-09-09 16:23:47 -0700885 /* do behind I/O ? */
886 if (bitmap &&
887 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
888 (behind_pages = alloc_behind_pages(bio)) != NULL)
889 set_bit(R1BIO_BehindIO, &r1_bio->state);
890
NeilBrown191ea9b2005-06-21 17:17:23 -0700891 atomic_set(&r1_bio->remaining, 0);
NeilBrown4b6d2872005-09-09 16:23:47 -0700892 atomic_set(&r1_bio->behind_remaining, 0);
NeilBrown191ea9b2005-06-21 17:17:23 -0700893
NeilBrown04b857f2006-03-09 17:33:46 -0800894 do_barriers = bio_barrier(bio);
NeilBrowna9701a32005-11-08 21:39:34 -0800895 if (do_barriers)
896 set_bit(R1BIO_Barrier, &r1_bio->state);
897
NeilBrown191ea9b2005-06-21 17:17:23 -0700898 bio_list_init(&bl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 for (i = 0; i < disks; i++) {
900 struct bio *mbio;
901 if (!r1_bio->bios[i])
902 continue;
903
904 mbio = bio_clone(bio, GFP_NOIO);
905 r1_bio->bios[i] = mbio;
906
907 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
908 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
909 mbio->bi_end_io = raid1_end_write_request;
Lars Ellenberge3881a62007-01-10 23:15:37 -0800910 mbio->bi_rw = WRITE | do_barriers | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 mbio->bi_private = r1_bio;
912
NeilBrown4b6d2872005-09-09 16:23:47 -0700913 if (behind_pages) {
914 struct bio_vec *bvec;
915 int j;
916
917 /* Yes, I really want the '__' version so that
918 * we clear any unused pointer in the io_vec, rather
919 * than leave them unchanged. This is important
920 * because when we come to free the pages, we won't
921 * know the originial bi_idx, so we just free
922 * them all
923 */
924 __bio_for_each_segment(bvec, mbio, j, 0)
925 bvec->bv_page = behind_pages[j];
926 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
927 atomic_inc(&r1_bio->behind_remaining);
928 }
929
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 atomic_inc(&r1_bio->remaining);
NeilBrown191ea9b2005-06-21 17:17:23 -0700931
932 bio_list_add(&bl, mbio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 }
NeilBrown4b6d2872005-09-09 16:23:47 -0700934 kfree(behind_pages); /* the behind pages are attached to the bios now */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
NeilBrown4b6d2872005-09-09 16:23:47 -0700936 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
937 test_bit(R1BIO_BehindIO, &r1_bio->state));
NeilBrown191ea9b2005-06-21 17:17:23 -0700938 spin_lock_irqsave(&conf->device_lock, flags);
939 bio_list_merge(&conf->pending_bio_list, &bl);
940 bio_list_init(&bl);
941
942 blk_plug_device(mddev->queue);
943 spin_unlock_irqrestore(&conf->device_lock, flags);
944
Lars Ellenberge3881a62007-01-10 23:15:37 -0800945 if (do_sync)
946 md_wakeup_thread(mddev->thread);
NeilBrown191ea9b2005-06-21 17:17:23 -0700947#if 0
948 while ((bio = bio_list_pop(&bl)) != NULL)
949 generic_make_request(bio);
950#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
952 return 0;
953}
954
955static void status(struct seq_file *seq, mddev_t *mddev)
956{
957 conf_t *conf = mddev_to_conf(mddev);
958 int i;
959
960 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
NeilBrown11ce99e2006-10-03 01:15:52 -0700961 conf->raid_disks - mddev->degraded);
NeilBrownddac7c72006-08-31 21:27:36 -0700962 rcu_read_lock();
963 for (i = 0; i < conf->raid_disks; i++) {
964 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 seq_printf(seq, "%s",
NeilBrownddac7c72006-08-31 21:27:36 -0700966 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
967 }
968 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 seq_printf(seq, "]");
970}
971
972
973static void error(mddev_t *mddev, mdk_rdev_t *rdev)
974{
975 char b[BDEVNAME_SIZE];
976 conf_t *conf = mddev_to_conf(mddev);
977
978 /*
979 * If it is not operational, then we have already marked it as dead
980 * else if it is the last working disks, ignore the error, let the
981 * next level up know.
982 * else mark the drive as failed
983 */
NeilBrownb2d444d2005-11-08 21:39:31 -0800984 if (test_bit(In_sync, &rdev->flags)
NeilBrown11ce99e2006-10-03 01:15:52 -0700985 && (conf->raid_disks - mddev->degraded) == 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 /*
987 * Don't fail the drive, act as though we were just a
988 * normal single drive
989 */
990 return;
NeilBrownc04be0a2006-10-03 01:15:53 -0700991 if (test_and_clear_bit(In_sync, &rdev->flags)) {
992 unsigned long flags;
993 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -0700995 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 /*
997 * if recovery is running, make sure it aborts.
998 */
999 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
1000 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001001 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -07001002 set_bit(MD_CHANGE_DEVS, &mddev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
1004 " Operation continuing on %d devices\n",
NeilBrown11ce99e2006-10-03 01:15:52 -07001005 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006}
1007
1008static void print_conf(conf_t *conf)
1009{
1010 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011
1012 printk("RAID1 conf printout:\n");
1013 if (!conf) {
1014 printk("(!conf)\n");
1015 return;
1016 }
NeilBrown11ce99e2006-10-03 01:15:52 -07001017 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 conf->raid_disks);
1019
NeilBrownddac7c72006-08-31 21:27:36 -07001020 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 for (i = 0; i < conf->raid_disks; i++) {
1022 char b[BDEVNAME_SIZE];
NeilBrownddac7c72006-08-31 21:27:36 -07001023 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1024 if (rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
NeilBrownddac7c72006-08-31 21:27:36 -07001026 i, !test_bit(In_sync, &rdev->flags),
1027 !test_bit(Faulty, &rdev->flags),
1028 bdevname(rdev->bdev,b));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 }
NeilBrownddac7c72006-08-31 21:27:36 -07001030 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031}
1032
1033static void close_sync(conf_t *conf)
1034{
NeilBrown17999be2006-01-06 00:20:12 -08001035 wait_barrier(conf);
1036 allow_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037
1038 mempool_destroy(conf->r1buf_pool);
1039 conf->r1buf_pool = NULL;
1040}
1041
1042static int raid1_spare_active(mddev_t *mddev)
1043{
1044 int i;
1045 conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046
1047 /*
1048 * Find all failed disks within the RAID1 configuration
NeilBrownddac7c72006-08-31 21:27:36 -07001049 * and mark them readable.
1050 * Called under mddev lock, so rcu protection not needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 */
1052 for (i = 0; i < conf->raid_disks; i++) {
NeilBrownddac7c72006-08-31 21:27:36 -07001053 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1054 if (rdev
1055 && !test_bit(Faulty, &rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07001056 && !test_and_set_bit(In_sync, &rdev->flags)) {
1057 unsigned long flags;
1058 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07001060 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 }
1062 }
1063
1064 print_conf(conf);
1065 return 0;
1066}
1067
1068
1069static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1070{
1071 conf_t *conf = mddev->private;
1072 int found = 0;
NeilBrown41158c72005-06-21 17:17:25 -07001073 int mirror = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 mirror_info_t *p;
1075
1076 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1077 if ( !(p=conf->mirrors+mirror)->rdev) {
1078
1079 blk_queue_stack_limits(mddev->queue,
1080 rdev->bdev->bd_disk->queue);
1081 /* as we don't honour merge_bvec_fn, we must never risk
1082 * violating it, so limit ->max_sector to one PAGE, as
1083 * a one page request is never in violation.
1084 */
1085 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1086 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1087 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1088
1089 p->head_position = 0;
1090 rdev->raid_disk = mirror;
1091 found = 1;
NeilBrown6aea114a2005-11-28 13:44:13 -08001092 /* As all devices are equivalent, we don't need a full recovery
1093 * if this was recently any drive of the array
1094 */
1095 if (rdev->saved_raid_disk < 0)
NeilBrown41158c72005-06-21 17:17:25 -07001096 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08001097 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 break;
1099 }
1100
1101 print_conf(conf);
1102 return found;
1103}
1104
1105static int raid1_remove_disk(mddev_t *mddev, int number)
1106{
1107 conf_t *conf = mddev->private;
1108 int err = 0;
1109 mdk_rdev_t *rdev;
1110 mirror_info_t *p = conf->mirrors+ number;
1111
1112 print_conf(conf);
1113 rdev = p->rdev;
1114 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08001115 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 atomic_read(&rdev->nr_pending)) {
1117 err = -EBUSY;
1118 goto abort;
1119 }
1120 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07001121 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 if (atomic_read(&rdev->nr_pending)) {
1123 /* lost the race, try later */
1124 err = -EBUSY;
1125 p->rdev = rdev;
1126 }
1127 }
1128abort:
1129
1130 print_conf(conf);
1131 return err;
1132}
1133
1134
1135static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1136{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
NeilBrownd11c1712006-01-06 00:20:26 -08001138 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
1140 if (bio->bi_size)
1141 return 1;
1142
NeilBrownd11c1712006-01-06 00:20:26 -08001143 for (i=r1_bio->mddev->raid_disks; i--; )
1144 if (r1_bio->bios[i] == bio)
1145 break;
1146 BUG_ON(i < 0);
1147 update_head_pos(i, r1_bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 /*
1149 * we have read a block, now it needs to be re-written,
1150 * or re-read if the read failed.
1151 * We don't do much here, just schedule handling by raid1d
1152 */
NeilBrown69382e82006-01-06 00:20:22 -08001153 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 set_bit(R1BIO_Uptodate, &r1_bio->state);
NeilBrownd11c1712006-01-06 00:20:26 -08001155
1156 if (atomic_dec_and_test(&r1_bio->remaining))
1157 reschedule_retry(r1_bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 return 0;
1159}
1160
1161static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1162{
1163 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1164 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1165 mddev_t *mddev = r1_bio->mddev;
1166 conf_t *conf = mddev_to_conf(mddev);
1167 int i;
1168 int mirror=0;
1169
1170 if (bio->bi_size)
1171 return 1;
1172
1173 for (i = 0; i < conf->raid_disks; i++)
1174 if (r1_bio->bios[i] == bio) {
1175 mirror = i;
1176 break;
1177 }
NeilBrown6b1117d2006-03-31 02:31:57 -08001178 if (!uptodate) {
1179 int sync_blocks = 0;
1180 sector_t s = r1_bio->sector;
1181 long sectors_to_go = r1_bio->sectors;
1182 /* make sure these bits doesn't get cleared. */
1183 do {
NeilBrown5e3db642006-07-10 04:44:18 -07001184 bitmap_end_sync(mddev->bitmap, s,
NeilBrown6b1117d2006-03-31 02:31:57 -08001185 &sync_blocks, 1);
1186 s += sync_blocks;
1187 sectors_to_go -= sync_blocks;
1188 } while (sectors_to_go > 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 md_error(mddev, conf->mirrors[mirror].rdev);
NeilBrown6b1117d2006-03-31 02:31:57 -08001190 }
NeilBrowne3b97032005-08-04 12:53:34 -07001191
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 update_head_pos(mirror, r1_bio);
1193
1194 if (atomic_dec_and_test(&r1_bio->remaining)) {
1195 md_done_sync(mddev, r1_bio->sectors, uptodate);
1196 put_buf(r1_bio);
1197 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 return 0;
1199}
1200
1201static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1202{
1203 conf_t *conf = mddev_to_conf(mddev);
1204 int i;
1205 int disks = conf->raid_disks;
1206 struct bio *bio, *wbio;
1207
1208 bio = r1_bio->bios[r1_bio->read_disk];
1209
NeilBrown69382e82006-01-06 00:20:22 -08001210
NeilBrownd11c1712006-01-06 00:20:26 -08001211 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1212 /* We have read all readable devices. If we haven't
1213 * got the block, then there is no hope left.
1214 * If we have, then we want to do a comparison
1215 * and skip the write if everything is the same.
1216 * If any blocks failed to read, then we need to
1217 * attempt an over-write
1218 */
1219 int primary;
1220 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1221 for (i=0; i<mddev->raid_disks; i++)
1222 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1223 md_error(mddev, conf->mirrors[i].rdev);
1224
1225 md_done_sync(mddev, r1_bio->sectors, 1);
1226 put_buf(r1_bio);
1227 return;
1228 }
1229 for (primary=0; primary<mddev->raid_disks; primary++)
1230 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1231 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1232 r1_bio->bios[primary]->bi_end_io = NULL;
NeilBrown03c902e2006-01-06 00:20:46 -08001233 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
NeilBrownd11c1712006-01-06 00:20:26 -08001234 break;
1235 }
1236 r1_bio->read_disk = primary;
1237 for (i=0; i<mddev->raid_disks; i++)
1238 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1239 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1240 int j;
1241 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1242 struct bio *pbio = r1_bio->bios[primary];
1243 struct bio *sbio = r1_bio->bios[i];
1244 for (j = vcnt; j-- ; )
1245 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1246 page_address(sbio->bi_io_vec[j].bv_page),
1247 PAGE_SIZE))
1248 break;
1249 if (j >= 0)
1250 mddev->resync_mismatches += r1_bio->sectors;
NeilBrown03c902e2006-01-06 00:20:46 -08001251 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
NeilBrownd11c1712006-01-06 00:20:26 -08001252 sbio->bi_end_io = NULL;
NeilBrown03c902e2006-01-06 00:20:46 -08001253 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1254 } else {
NeilBrownd11c1712006-01-06 00:20:26 -08001255 /* fixup the bio for reuse */
1256 sbio->bi_vcnt = vcnt;
1257 sbio->bi_size = r1_bio->sectors << 9;
1258 sbio->bi_idx = 0;
1259 sbio->bi_phys_segments = 0;
1260 sbio->bi_hw_segments = 0;
1261 sbio->bi_hw_front_size = 0;
1262 sbio->bi_hw_back_size = 0;
1263 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1264 sbio->bi_flags |= 1 << BIO_UPTODATE;
1265 sbio->bi_next = NULL;
1266 sbio->bi_sector = r1_bio->sector +
1267 conf->mirrors[i].rdev->data_offset;
1268 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
NeilBrown3eda22d2007-01-26 00:57:01 -08001269 for (j = 0; j < vcnt ; j++)
1270 memcpy(page_address(sbio->bi_io_vec[j].bv_page),
1271 page_address(pbio->bi_io_vec[j].bv_page),
1272 PAGE_SIZE);
1273
NeilBrownd11c1712006-01-06 00:20:26 -08001274 }
1275 }
1276 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
NeilBrown69382e82006-01-06 00:20:22 -08001278 /* ouch - failed to read all of that.
1279 * Try some synchronous reads of other devices to get
1280 * good data, much like with normal read errors. Only
NeilBrownddac7c72006-08-31 21:27:36 -07001281 * read into the pages we already have so we don't
NeilBrown69382e82006-01-06 00:20:22 -08001282 * need to re-issue the read request.
1283 * We don't need to freeze the array, because being in an
1284 * active sync request, there is no normal IO, and
1285 * no overlapping syncs.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 */
NeilBrown69382e82006-01-06 00:20:22 -08001287 sector_t sect = r1_bio->sector;
1288 int sectors = r1_bio->sectors;
1289 int idx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290
NeilBrown69382e82006-01-06 00:20:22 -08001291 while(sectors) {
1292 int s = sectors;
1293 int d = r1_bio->read_disk;
1294 int success = 0;
1295 mdk_rdev_t *rdev;
1296
1297 if (s > (PAGE_SIZE>>9))
1298 s = PAGE_SIZE >> 9;
1299 do {
1300 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
NeilBrownddac7c72006-08-31 21:27:36 -07001301 /* No rcu protection needed here devices
1302 * can only be removed when no resync is
1303 * active, and resync is currently active
1304 */
NeilBrown69382e82006-01-06 00:20:22 -08001305 rdev = conf->mirrors[d].rdev;
1306 if (sync_page_io(rdev->bdev,
1307 sect + rdev->data_offset,
1308 s<<9,
1309 bio->bi_io_vec[idx].bv_page,
1310 READ)) {
1311 success = 1;
1312 break;
1313 }
1314 }
1315 d++;
1316 if (d == conf->raid_disks)
1317 d = 0;
1318 } while (!success && d != r1_bio->read_disk);
1319
1320 if (success) {
NeilBrown097426f2006-01-06 00:20:37 -08001321 int start = d;
NeilBrown69382e82006-01-06 00:20:22 -08001322 /* write it back and re-read */
1323 set_bit(R1BIO_Uptodate, &r1_bio->state);
1324 while (d != r1_bio->read_disk) {
1325 if (d == 0)
1326 d = conf->raid_disks;
1327 d--;
1328 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1329 continue;
1330 rdev = conf->mirrors[d].rdev;
NeilBrown4dbcdc72006-01-06 00:20:52 -08001331 atomic_add(s, &rdev->corrected_errors);
NeilBrown69382e82006-01-06 00:20:22 -08001332 if (sync_page_io(rdev->bdev,
1333 sect + rdev->data_offset,
1334 s<<9,
1335 bio->bi_io_vec[idx].bv_page,
NeilBrown097426f2006-01-06 00:20:37 -08001336 WRITE) == 0)
1337 md_error(mddev, rdev);
1338 }
1339 d = start;
1340 while (d != r1_bio->read_disk) {
1341 if (d == 0)
1342 d = conf->raid_disks;
1343 d--;
1344 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1345 continue;
1346 rdev = conf->mirrors[d].rdev;
1347 if (sync_page_io(rdev->bdev,
NeilBrown69382e82006-01-06 00:20:22 -08001348 sect + rdev->data_offset,
1349 s<<9,
1350 bio->bi_io_vec[idx].bv_page,
NeilBrown097426f2006-01-06 00:20:37 -08001351 READ) == 0)
NeilBrown69382e82006-01-06 00:20:22 -08001352 md_error(mddev, rdev);
NeilBrown69382e82006-01-06 00:20:22 -08001353 }
1354 } else {
1355 char b[BDEVNAME_SIZE];
1356 /* Cannot read from anywhere, array is toast */
1357 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1358 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1359 " for block %llu\n",
1360 bdevname(bio->bi_bdev,b),
1361 (unsigned long long)r1_bio->sector);
1362 md_done_sync(mddev, r1_bio->sectors, 0);
1363 put_buf(r1_bio);
1364 return;
1365 }
1366 sectors -= s;
1367 sect += s;
1368 idx ++;
1369 }
1370 }
NeilBrownd11c1712006-01-06 00:20:26 -08001371
1372 /*
1373 * schedule writes
1374 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375 atomic_set(&r1_bio->remaining, 1);
1376 for (i = 0; i < disks ; i++) {
1377 wbio = r1_bio->bios[i];
NeilBrown3e198f72006-01-06 00:20:21 -08001378 if (wbio->bi_end_io == NULL ||
1379 (wbio->bi_end_io == end_sync_read &&
1380 (i == r1_bio->read_disk ||
1381 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 continue;
1383
NeilBrown3e198f72006-01-06 00:20:21 -08001384 wbio->bi_rw = WRITE;
1385 wbio->bi_end_io = end_sync_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 atomic_inc(&r1_bio->remaining);
1387 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
NeilBrown191ea9b2005-06-21 17:17:23 -07001388
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 generic_make_request(wbio);
1390 }
1391
1392 if (atomic_dec_and_test(&r1_bio->remaining)) {
NeilBrown191ea9b2005-06-21 17:17:23 -07001393 /* if we're here, all write(s) have completed, so clean up */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 md_done_sync(mddev, r1_bio->sectors, 1);
1395 put_buf(r1_bio);
1396 }
1397}
1398
1399/*
1400 * This is a kernel thread which:
1401 *
1402 * 1. Retries failed read operations on working mirrors.
1403 * 2. Updates the raid superblock when problems encounter.
1404 * 3. Performs writes following reads for array syncronising.
1405 */
1406
NeilBrown867868f2006-10-03 01:15:51 -07001407static void fix_read_error(conf_t *conf, int read_disk,
1408 sector_t sect, int sectors)
1409{
1410 mddev_t *mddev = conf->mddev;
1411 while(sectors) {
1412 int s = sectors;
1413 int d = read_disk;
1414 int success = 0;
1415 int start;
1416 mdk_rdev_t *rdev;
1417
1418 if (s > (PAGE_SIZE>>9))
1419 s = PAGE_SIZE >> 9;
1420
1421 do {
1422 /* Note: no rcu protection needed here
1423 * as this is synchronous in the raid1d thread
1424 * which is the thread that might remove
1425 * a device. If raid1d ever becomes multi-threaded....
1426 */
1427 rdev = conf->mirrors[d].rdev;
1428 if (rdev &&
1429 test_bit(In_sync, &rdev->flags) &&
1430 sync_page_io(rdev->bdev,
1431 sect + rdev->data_offset,
1432 s<<9,
1433 conf->tmppage, READ))
1434 success = 1;
1435 else {
1436 d++;
1437 if (d == conf->raid_disks)
1438 d = 0;
1439 }
1440 } while (!success && d != read_disk);
1441
1442 if (!success) {
1443 /* Cannot read from anywhere -- bye bye array */
1444 md_error(mddev, conf->mirrors[read_disk].rdev);
1445 break;
1446 }
1447 /* write it back and re-read */
1448 start = d;
1449 while (d != read_disk) {
1450 if (d==0)
1451 d = conf->raid_disks;
1452 d--;
1453 rdev = conf->mirrors[d].rdev;
1454 if (rdev &&
1455 test_bit(In_sync, &rdev->flags)) {
1456 if (sync_page_io(rdev->bdev,
1457 sect + rdev->data_offset,
1458 s<<9, conf->tmppage, WRITE)
1459 == 0)
1460 /* Well, this device is dead */
1461 md_error(mddev, rdev);
1462 }
1463 }
1464 d = start;
1465 while (d != read_disk) {
1466 char b[BDEVNAME_SIZE];
1467 if (d==0)
1468 d = conf->raid_disks;
1469 d--;
1470 rdev = conf->mirrors[d].rdev;
1471 if (rdev &&
1472 test_bit(In_sync, &rdev->flags)) {
1473 if (sync_page_io(rdev->bdev,
1474 sect + rdev->data_offset,
1475 s<<9, conf->tmppage, READ)
1476 == 0)
1477 /* Well, this device is dead */
1478 md_error(mddev, rdev);
1479 else {
1480 atomic_add(s, &rdev->corrected_errors);
1481 printk(KERN_INFO
1482 "raid1:%s: read error corrected "
1483 "(%d sectors at %llu on %s)\n",
1484 mdname(mddev), s,
Randy Dunlap969b7552006-10-28 10:38:32 -07001485 (unsigned long long)(sect +
1486 rdev->data_offset),
NeilBrown867868f2006-10-03 01:15:51 -07001487 bdevname(rdev->bdev, b));
1488 }
1489 }
1490 }
1491 sectors -= s;
1492 sect += s;
1493 }
1494}
1495
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496static void raid1d(mddev_t *mddev)
1497{
1498 r1bio_t *r1_bio;
1499 struct bio *bio;
1500 unsigned long flags;
1501 conf_t *conf = mddev_to_conf(mddev);
1502 struct list_head *head = &conf->retry_list;
1503 int unplug=0;
1504 mdk_rdev_t *rdev;
1505
1506 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507
1508 for (;;) {
1509 char b[BDEVNAME_SIZE];
1510 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown191ea9b2005-06-21 17:17:23 -07001511
1512 if (conf->pending_bio_list.head) {
1513 bio = bio_list_get(&conf->pending_bio_list);
1514 blk_remove_plug(mddev->queue);
1515 spin_unlock_irqrestore(&conf->device_lock, flags);
1516 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1517 if (bitmap_unplug(mddev->bitmap) != 0)
1518 printk("%s: bitmap file write failed!\n", mdname(mddev));
1519
1520 while (bio) { /* submit pending writes */
1521 struct bio *next = bio->bi_next;
1522 bio->bi_next = NULL;
1523 generic_make_request(bio);
1524 bio = next;
1525 }
1526 unplug = 1;
1527
1528 continue;
1529 }
1530
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531 if (list_empty(head))
1532 break;
1533 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1534 list_del(head->prev);
NeilBrownddaf22a2006-01-06 00:20:19 -08001535 conf->nr_queued--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 spin_unlock_irqrestore(&conf->device_lock, flags);
1537
1538 mddev = r1_bio->mddev;
1539 conf = mddev_to_conf(mddev);
1540 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1541 sync_request_write(mddev, r1_bio);
1542 unplug = 1;
NeilBrowna9701a32005-11-08 21:39:34 -08001543 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1544 /* some requests in the r1bio were BIO_RW_BARRIER
NeilBrownbea27712006-05-01 12:15:46 -07001545 * requests which failed with -EOPNOTSUPP. Hohumm..
NeilBrowna9701a32005-11-08 21:39:34 -08001546 * Better resubmit without the barrier.
1547 * We know which devices to resubmit for, because
1548 * all others have had their bios[] entry cleared.
NeilBrown5e7dd2a2006-05-01 12:15:47 -07001549 * We already have a nr_pending reference on these rdevs.
NeilBrowna9701a32005-11-08 21:39:34 -08001550 */
1551 int i;
Lars Ellenberge3881a62007-01-10 23:15:37 -08001552 const int do_sync = bio_sync(r1_bio->master_bio);
NeilBrowna9701a32005-11-08 21:39:34 -08001553 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1554 clear_bit(R1BIO_Barrier, &r1_bio->state);
1555 for (i=0; i < conf->raid_disks; i++)
NeilBrown2f889122006-03-27 01:18:19 -08001556 if (r1_bio->bios[i])
1557 atomic_inc(&r1_bio->remaining);
1558 for (i=0; i < conf->raid_disks; i++)
NeilBrowna9701a32005-11-08 21:39:34 -08001559 if (r1_bio->bios[i]) {
1560 struct bio_vec *bvec;
1561 int j;
1562
1563 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1564 /* copy pages from the failed bio, as
1565 * this might be a write-behind device */
1566 __bio_for_each_segment(bvec, bio, j, 0)
1567 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1568 bio_put(r1_bio->bios[i]);
1569 bio->bi_sector = r1_bio->sector +
1570 conf->mirrors[i].rdev->data_offset;
1571 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1572 bio->bi_end_io = raid1_end_write_request;
Lars Ellenberge3881a62007-01-10 23:15:37 -08001573 bio->bi_rw = WRITE | do_sync;
NeilBrowna9701a32005-11-08 21:39:34 -08001574 bio->bi_private = r1_bio;
1575 r1_bio->bios[i] = bio;
1576 generic_make_request(bio);
1577 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 } else {
1579 int disk;
NeilBrownddaf22a2006-01-06 00:20:19 -08001580
1581 /* we got a read error. Maybe the drive is bad. Maybe just
1582 * the block and we can fix it.
1583 * We freeze all other IO, and try reading the block from
1584 * other devices. When we find one, we re-write
1585 * and check it that fixes the read error.
1586 * This is all done synchronously while the array is
1587 * frozen
1588 */
NeilBrown867868f2006-10-03 01:15:51 -07001589 if (mddev->ro == 0) {
1590 freeze_array(conf);
1591 fix_read_error(conf, r1_bio->read_disk,
1592 r1_bio->sector,
1593 r1_bio->sectors);
1594 unfreeze_array(conf);
NeilBrownddaf22a2006-01-06 00:20:19 -08001595 }
1596
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 bio = r1_bio->bios[r1_bio->read_disk];
1598 if ((disk=read_balance(conf, r1_bio)) == -1) {
1599 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1600 " read error for block %llu\n",
1601 bdevname(bio->bi_bdev,b),
1602 (unsigned long long)r1_bio->sector);
1603 raid_end_bio_io(r1_bio);
1604 } else {
Lars Ellenberge3881a62007-01-10 23:15:37 -08001605 const int do_sync = bio_sync(r1_bio->master_bio);
NeilBrowncf30a472006-01-06 00:20:23 -08001606 r1_bio->bios[r1_bio->read_disk] =
1607 mddev->ro ? IO_BLOCKED : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 r1_bio->read_disk = disk;
1609 bio_put(bio);
1610 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1611 r1_bio->bios[r1_bio->read_disk] = bio;
1612 rdev = conf->mirrors[disk].rdev;
1613 if (printk_ratelimit())
1614 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1615 " another mirror\n",
1616 bdevname(rdev->bdev,b),
1617 (unsigned long long)r1_bio->sector);
1618 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1619 bio->bi_bdev = rdev->bdev;
1620 bio->bi_end_io = raid1_end_read_request;
Lars Ellenberge3881a62007-01-10 23:15:37 -08001621 bio->bi_rw = READ | do_sync;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 bio->bi_private = r1_bio;
1623 unplug = 1;
1624 generic_make_request(bio);
1625 }
1626 }
1627 }
1628 spin_unlock_irqrestore(&conf->device_lock, flags);
1629 if (unplug)
1630 unplug_slaves(mddev);
1631}
1632
1633
1634static int init_resync(conf_t *conf)
1635{
1636 int buffs;
1637
1638 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
Eric Sesterhenn9e77c482006-04-01 01:08:49 +02001639 BUG_ON(conf->r1buf_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1641 conf->poolinfo);
1642 if (!conf->r1buf_pool)
1643 return -ENOMEM;
1644 conf->next_resync = 0;
1645 return 0;
1646}
1647
1648/*
1649 * perform a "sync" on one "block"
1650 *
1651 * We need to make sure that no normal I/O request - particularly write
1652 * requests - conflict with active sync requests.
1653 *
1654 * This is achieved by tracking pending requests and a 'barrier' concept
1655 * that can be installed to exclude normal IO requests.
1656 */
1657
NeilBrown57afd892005-06-21 17:17:13 -07001658static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659{
1660 conf_t *conf = mddev_to_conf(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 r1bio_t *r1_bio;
1662 struct bio *bio;
1663 sector_t max_sector, nr_sectors;
NeilBrown3e198f72006-01-06 00:20:21 -08001664 int disk = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665 int i;
NeilBrown3e198f72006-01-06 00:20:21 -08001666 int wonly = -1;
1667 int write_targets = 0, read_targets = 0;
NeilBrown191ea9b2005-06-21 17:17:23 -07001668 int sync_blocks;
NeilBrowne3b97032005-08-04 12:53:34 -07001669 int still_degraded = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670
1671 if (!conf->r1buf_pool)
NeilBrown191ea9b2005-06-21 17:17:23 -07001672 {
1673/*
1674 printk("sync start - bitmap %p\n", mddev->bitmap);
1675*/
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 if (init_resync(conf))
NeilBrown57afd892005-06-21 17:17:13 -07001677 return 0;
NeilBrown191ea9b2005-06-21 17:17:23 -07001678 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679
1680 max_sector = mddev->size << 1;
1681 if (sector_nr >= max_sector) {
NeilBrown191ea9b2005-06-21 17:17:23 -07001682 /* If we aborted, we need to abort the
1683 * sync on the 'current' bitmap chunk (there will
1684 * only be one in raid1 resync.
1685 * We can find the current addess in mddev->curr_resync
1686 */
NeilBrown6a806c52005-07-15 03:56:35 -07001687 if (mddev->curr_resync < max_sector) /* aborted */
1688 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
NeilBrown191ea9b2005-06-21 17:17:23 -07001689 &sync_blocks, 1);
NeilBrown6a806c52005-07-15 03:56:35 -07001690 else /* completed sync */
NeilBrown191ea9b2005-06-21 17:17:23 -07001691 conf->fullsync = 0;
NeilBrown6a806c52005-07-15 03:56:35 -07001692
1693 bitmap_close_sync(mddev->bitmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 close_sync(conf);
1695 return 0;
1696 }
1697
NeilBrown07d84d102006-06-26 00:27:56 -07001698 if (mddev->bitmap == NULL &&
1699 mddev->recovery_cp == MaxSector &&
NeilBrown6394cca2006-08-27 01:23:50 -07001700 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown07d84d102006-06-26 00:27:56 -07001701 conf->fullsync == 0) {
1702 *skipped = 1;
1703 return max_sector - sector_nr;
1704 }
NeilBrown6394cca2006-08-27 01:23:50 -07001705 /* before building a request, check if we can skip these blocks..
1706 * This call the bitmap_start_sync doesn't actually record anything
1707 */
NeilBrowne3b97032005-08-04 12:53:34 -07001708 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrowne5de485f2005-11-08 21:39:38 -08001709 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
NeilBrown191ea9b2005-06-21 17:17:23 -07001710 /* We can skip this block, and probably several more */
1711 *skipped = 1;
1712 return sync_blocks;
1713 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 /*
NeilBrown17999be2006-01-06 00:20:12 -08001715 * If there is non-resync activity waiting for a turn,
1716 * and resync is going fast enough,
1717 * then let it though before starting on this new sync request.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 */
NeilBrown17999be2006-01-06 00:20:12 -08001719 if (!go_faster && conf->nr_waiting)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 msleep_interruptible(1000);
NeilBrown17999be2006-01-06 00:20:12 -08001721
1722 raise_barrier(conf);
1723
1724 conf->next_resync = sector_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
NeilBrown3e198f72006-01-06 00:20:21 -08001727 rcu_read_lock();
1728 /*
1729 * If we get a correctably read error during resync or recovery,
1730 * we might want to read from a different device. So we
1731 * flag all drives that could conceivably be read from for READ,
1732 * and any others (which will be non-In_sync devices) for WRITE.
1733 * If a read fails, we try reading from something else for which READ
1734 * is OK.
1735 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 r1_bio->mddev = mddev;
1738 r1_bio->sector = sector_nr;
NeilBrown191ea9b2005-06-21 17:17:23 -07001739 r1_bio->state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740 set_bit(R1BIO_IsSync, &r1_bio->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741
1742 for (i=0; i < conf->raid_disks; i++) {
NeilBrown3e198f72006-01-06 00:20:21 -08001743 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 bio = r1_bio->bios[i];
1745
1746 /* take from bio_init */
1747 bio->bi_next = NULL;
1748 bio->bi_flags |= 1 << BIO_UPTODATE;
NeilBrown802ba062006-12-13 00:34:13 -08001749 bio->bi_rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 bio->bi_vcnt = 0;
1751 bio->bi_idx = 0;
1752 bio->bi_phys_segments = 0;
1753 bio->bi_hw_segments = 0;
1754 bio->bi_size = 0;
1755 bio->bi_end_io = NULL;
1756 bio->bi_private = NULL;
1757
NeilBrown3e198f72006-01-06 00:20:21 -08001758 rdev = rcu_dereference(conf->mirrors[i].rdev);
1759 if (rdev == NULL ||
1760 test_bit(Faulty, &rdev->flags)) {
NeilBrowne3b97032005-08-04 12:53:34 -07001761 still_degraded = 1;
1762 continue;
NeilBrown3e198f72006-01-06 00:20:21 -08001763 } else if (!test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001764 bio->bi_rw = WRITE;
1765 bio->bi_end_io = end_sync_write;
1766 write_targets ++;
NeilBrown3e198f72006-01-06 00:20:21 -08001767 } else {
1768 /* may need to read from here */
1769 bio->bi_rw = READ;
1770 bio->bi_end_io = end_sync_read;
1771 if (test_bit(WriteMostly, &rdev->flags)) {
1772 if (wonly < 0)
1773 wonly = i;
1774 } else {
1775 if (disk < 0)
1776 disk = i;
1777 }
1778 read_targets++;
1779 }
1780 atomic_inc(&rdev->nr_pending);
1781 bio->bi_sector = sector_nr + rdev->data_offset;
1782 bio->bi_bdev = rdev->bdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783 bio->bi_private = r1_bio;
1784 }
NeilBrown3e198f72006-01-06 00:20:21 -08001785 rcu_read_unlock();
1786 if (disk < 0)
1787 disk = wonly;
1788 r1_bio->read_disk = disk;
NeilBrown191ea9b2005-06-21 17:17:23 -07001789
NeilBrown3e198f72006-01-06 00:20:21 -08001790 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1791 /* extra read targets are also write targets */
1792 write_targets += read_targets-1;
1793
1794 if (write_targets == 0 || read_targets == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 /* There is nowhere to write, so all non-sync
1796 * drives must be failed - so we are finished
1797 */
NeilBrown57afd892005-06-21 17:17:13 -07001798 sector_t rv = max_sector - sector_nr;
1799 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 put_buf(r1_bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 return rv;
1802 }
1803
1804 nr_sectors = 0;
NeilBrown289e99e2005-06-21 17:17:24 -07001805 sync_blocks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806 do {
1807 struct page *page;
1808 int len = PAGE_SIZE;
1809 if (sector_nr + (len>>9) > max_sector)
1810 len = (max_sector - sector_nr) << 9;
1811 if (len == 0)
1812 break;
NeilBrown6a806c52005-07-15 03:56:35 -07001813 if (sync_blocks == 0) {
1814 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
NeilBrowne5de485f2005-11-08 21:39:38 -08001815 &sync_blocks, still_degraded) &&
1816 !conf->fullsync &&
1817 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
NeilBrown6a806c52005-07-15 03:56:35 -07001818 break;
Eric Sesterhenn9e77c482006-04-01 01:08:49 +02001819 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
NeilBrown6a806c52005-07-15 03:56:35 -07001820 if (len > (sync_blocks<<9))
1821 len = sync_blocks<<9;
NeilBrownab7a30c2005-06-21 17:17:23 -07001822 }
NeilBrown191ea9b2005-06-21 17:17:23 -07001823
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 for (i=0 ; i < conf->raid_disks; i++) {
1825 bio = r1_bio->bios[i];
1826 if (bio->bi_end_io) {
NeilBrownd11c1712006-01-06 00:20:26 -08001827 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 if (bio_add_page(bio, page, len, 0) == 0) {
1829 /* stop here */
NeilBrownd11c1712006-01-06 00:20:26 -08001830 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 while (i > 0) {
1832 i--;
1833 bio = r1_bio->bios[i];
NeilBrown6a806c52005-07-15 03:56:35 -07001834 if (bio->bi_end_io==NULL)
1835 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836 /* remove last page from this bio */
1837 bio->bi_vcnt--;
1838 bio->bi_size -= len;
1839 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1840 }
1841 goto bio_full;
1842 }
1843 }
1844 }
1845 nr_sectors += len>>9;
1846 sector_nr += len>>9;
NeilBrown191ea9b2005-06-21 17:17:23 -07001847 sync_blocks -= (len>>9);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1849 bio_full:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850 r1_bio->sectors = nr_sectors;
1851
NeilBrownd11c1712006-01-06 00:20:26 -08001852 /* For a user-requested sync, we read all readable devices and do a
1853 * compare
1854 */
1855 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1856 atomic_set(&r1_bio->remaining, read_targets);
1857 for (i=0; i<conf->raid_disks; i++) {
1858 bio = r1_bio->bios[i];
1859 if (bio->bi_end_io == end_sync_read) {
NeilBrownddac7c72006-08-31 21:27:36 -07001860 md_sync_acct(bio->bi_bdev, nr_sectors);
NeilBrownd11c1712006-01-06 00:20:26 -08001861 generic_make_request(bio);
1862 }
1863 }
1864 } else {
1865 atomic_set(&r1_bio->remaining, 1);
1866 bio = r1_bio->bios[r1_bio->read_disk];
NeilBrownddac7c72006-08-31 21:27:36 -07001867 md_sync_acct(bio->bi_bdev, nr_sectors);
NeilBrownd11c1712006-01-06 00:20:26 -08001868 generic_make_request(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869
NeilBrownd11c1712006-01-06 00:20:26 -08001870 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871 return nr_sectors;
1872}
1873
1874static int run(mddev_t *mddev)
1875{
1876 conf_t *conf;
1877 int i, j, disk_idx;
1878 mirror_info_t *disk;
1879 mdk_rdev_t *rdev;
1880 struct list_head *tmp;
1881
1882 if (mddev->level != 1) {
1883 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1884 mdname(mddev), mddev->level);
1885 goto out;
1886 }
NeilBrownf6705572006-03-27 01:18:11 -08001887 if (mddev->reshape_position != MaxSector) {
1888 printk("raid1: %s: reshape_position set but not supported\n",
1889 mdname(mddev));
1890 goto out;
1891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 /*
1893 * copy the already verified devices into our private RAID1
1894 * bookkeeping area. [whatever we allocate in run(),
1895 * should be freed in stop()]
1896 */
NeilBrown9ffae0c2006-01-06 00:20:32 -08001897 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898 mddev->private = conf;
1899 if (!conf)
1900 goto out_no_mem;
1901
NeilBrown9ffae0c2006-01-06 00:20:32 -08001902 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 GFP_KERNEL);
1904 if (!conf->mirrors)
1905 goto out_no_mem;
1906
NeilBrownddaf22a2006-01-06 00:20:19 -08001907 conf->tmppage = alloc_page(GFP_KERNEL);
1908 if (!conf->tmppage)
1909 goto out_no_mem;
1910
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1912 if (!conf->poolinfo)
1913 goto out_no_mem;
1914 conf->poolinfo->mddev = mddev;
1915 conf->poolinfo->raid_disks = mddev->raid_disks;
1916 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1917 r1bio_pool_free,
1918 conf->poolinfo);
1919 if (!conf->r1bio_pool)
1920 goto out_no_mem;
1921
Linus Torvalds1da177e2005-04-16 15:20:36 -07001922 ITERATE_RDEV(mddev, rdev, tmp) {
1923 disk_idx = rdev->raid_disk;
1924 if (disk_idx >= mddev->raid_disks
1925 || disk_idx < 0)
1926 continue;
1927 disk = conf->mirrors + disk_idx;
1928
1929 disk->rdev = rdev;
1930
1931 blk_queue_stack_limits(mddev->queue,
1932 rdev->bdev->bd_disk->queue);
1933 /* as we don't honour merge_bvec_fn, we must never risk
1934 * violating it, so limit ->max_sector to one PAGE, as
1935 * a one page request is never in violation.
1936 */
1937 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1938 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1939 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1940
1941 disk->head_position = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942 }
1943 conf->raid_disks = mddev->raid_disks;
1944 conf->mddev = mddev;
1945 spin_lock_init(&conf->device_lock);
1946 INIT_LIST_HEAD(&conf->retry_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947
1948 spin_lock_init(&conf->resync_lock);
NeilBrown17999be2006-01-06 00:20:12 -08001949 init_waitqueue_head(&conf->wait_barrier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950
NeilBrown191ea9b2005-06-21 17:17:23 -07001951 bio_list_init(&conf->pending_bio_list);
1952 bio_list_init(&conf->flushing_bio_list);
1953
Linus Torvalds1da177e2005-04-16 15:20:36 -07001954
1955 mddev->degraded = 0;
1956 for (i = 0; i < conf->raid_disks; i++) {
1957
1958 disk = conf->mirrors + i;
1959
NeilBrown5fd6c1d2006-06-26 00:27:40 -07001960 if (!disk->rdev ||
1961 !test_bit(In_sync, &disk->rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001962 disk->head_position = 0;
1963 mddev->degraded++;
NeilBrown17571282006-12-10 02:20:52 -08001964 conf->fullsync = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 }
1966 }
NeilBrown11ce99e2006-10-03 01:15:52 -07001967 if (mddev->degraded == conf->raid_disks) {
1968 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1969 mdname(mddev));
1970 goto out_free_conf;
1971 }
1972 if (conf->raid_disks - mddev->degraded == 1)
1973 mddev->recovery_cp = MaxSector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974
1975 /*
1976 * find the first working one and use it as a starting point
1977 * to read balancing.
1978 */
1979 for (j = 0; j < conf->raid_disks &&
1980 (!conf->mirrors[j].rdev ||
NeilBrownb2d444d2005-11-08 21:39:31 -08001981 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 /* nothing */;
1983 conf->last_used = j;
1984
1985
NeilBrown191ea9b2005-06-21 17:17:23 -07001986 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1987 if (!mddev->thread) {
1988 printk(KERN_ERR
1989 "raid1: couldn't allocate thread for %s\n",
1990 mdname(mddev));
1991 goto out_free_conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 }
NeilBrown191ea9b2005-06-21 17:17:23 -07001993
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994 printk(KERN_INFO
1995 "raid1: raid set %s active with %d out of %d mirrors\n",
1996 mdname(mddev), mddev->raid_disks - mddev->degraded,
1997 mddev->raid_disks);
1998 /*
1999 * Ok, everything is just fine now
2000 */
2001 mddev->array_size = mddev->size;
2002
NeilBrown7a5febe2005-05-16 21:53:16 -07002003 mddev->queue->unplug_fn = raid1_unplug;
2004 mddev->queue->issue_flush_fn = raid1_issue_flush;
NeilBrown0d129222006-10-03 01:15:54 -07002005 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2006 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -07002007
Linus Torvalds1da177e2005-04-16 15:20:36 -07002008 return 0;
2009
2010out_no_mem:
2011 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
2012 mdname(mddev));
2013
2014out_free_conf:
2015 if (conf) {
2016 if (conf->r1bio_pool)
2017 mempool_destroy(conf->r1bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002018 kfree(conf->mirrors);
NeilBrown1345b1d2006-01-06 00:20:40 -08002019 safe_put_page(conf->tmppage);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002020 kfree(conf->poolinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002021 kfree(conf);
2022 mddev->private = NULL;
2023 }
2024out:
2025 return -EIO;
2026}
2027
2028static int stop(mddev_t *mddev)
2029{
2030 conf_t *conf = mddev_to_conf(mddev);
NeilBrown4b6d2872005-09-09 16:23:47 -07002031 struct bitmap *bitmap = mddev->bitmap;
2032 int behind_wait = 0;
2033
2034 /* wait for behind writes to complete */
2035 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2036 behind_wait++;
2037 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
2038 set_current_state(TASK_UNINTERRUPTIBLE);
2039 schedule_timeout(HZ); /* wait a second */
2040 /* need to kick something here to make sure I/O goes? */
2041 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042
2043 md_unregister_thread(mddev->thread);
2044 mddev->thread = NULL;
2045 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2046 if (conf->r1bio_pool)
2047 mempool_destroy(conf->r1bio_pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -07002048 kfree(conf->mirrors);
2049 kfree(conf->poolinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 kfree(conf);
2051 mddev->private = NULL;
2052 return 0;
2053}
2054
2055static int raid1_resize(mddev_t *mddev, sector_t sectors)
2056{
2057 /* no resync is happening, and there is enough space
2058 * on all devices, so we can resize.
2059 * We need to make sure resync covers any new space.
2060 * If the array is shrinking we should possibly wait until
2061 * any io in the removed space completes, but it hardly seems
2062 * worth it.
2063 */
2064 mddev->array_size = sectors>>1;
2065 set_capacity(mddev->gendisk, mddev->array_size << 1);
2066 mddev->changed = 1;
2067 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
2068 mddev->recovery_cp = mddev->size << 1;
2069 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2070 }
2071 mddev->size = mddev->array_size;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07002072 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 return 0;
2074}
2075
NeilBrown63c70c42006-03-27 01:18:13 -08002076static int raid1_reshape(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077{
2078 /* We need to:
2079 * 1/ resize the r1bio_pool
2080 * 2/ resize conf->mirrors
2081 *
2082 * We allocate a new r1bio_pool if we can.
2083 * Then raise a device barrier and wait until all IO stops.
2084 * Then resize conf->mirrors and swap in the new r1bio pool.
NeilBrown6ea9c072005-06-21 17:17:09 -07002085 *
2086 * At the same time, we "pack" the devices so that all the missing
2087 * devices have the higher raid_disk numbers.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088 */
2089 mempool_t *newpool, *oldpool;
2090 struct pool_info *newpoolinfo;
2091 mirror_info_t *newmirrors;
2092 conf_t *conf = mddev_to_conf(mddev);
NeilBrown63c70c42006-03-27 01:18:13 -08002093 int cnt, raid_disks;
NeilBrownc04be0a2006-10-03 01:15:53 -07002094 unsigned long flags;
NeilBrown6ea9c072005-06-21 17:17:09 -07002095 int d, d2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002096
NeilBrown63c70c42006-03-27 01:18:13 -08002097 /* Cannot change chunk_size, layout, or level */
2098 if (mddev->chunk_size != mddev->new_chunk ||
2099 mddev->layout != mddev->new_layout ||
2100 mddev->level != mddev->new_level) {
2101 mddev->new_chunk = mddev->chunk_size;
2102 mddev->new_layout = mddev->layout;
2103 mddev->new_level = mddev->level;
2104 return -EINVAL;
2105 }
2106
NeilBrown2a2275d2007-01-26 00:57:11 -08002107 md_allow_write(mddev);
2108
NeilBrown63c70c42006-03-27 01:18:13 -08002109 raid_disks = mddev->raid_disks + mddev->delta_disks;
2110
NeilBrown6ea9c072005-06-21 17:17:09 -07002111 if (raid_disks < conf->raid_disks) {
2112 cnt=0;
2113 for (d= 0; d < conf->raid_disks; d++)
2114 if (conf->mirrors[d].rdev)
2115 cnt++;
2116 if (cnt > raid_disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002117 return -EBUSY;
NeilBrown6ea9c072005-06-21 17:17:09 -07002118 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002119
2120 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2121 if (!newpoolinfo)
2122 return -ENOMEM;
2123 newpoolinfo->mddev = mddev;
2124 newpoolinfo->raid_disks = raid_disks;
2125
2126 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2127 r1bio_pool_free, newpoolinfo);
2128 if (!newpool) {
2129 kfree(newpoolinfo);
2130 return -ENOMEM;
2131 }
NeilBrown9ffae0c2006-01-06 00:20:32 -08002132 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133 if (!newmirrors) {
2134 kfree(newpoolinfo);
2135 mempool_destroy(newpool);
2136 return -ENOMEM;
2137 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138
NeilBrown17999be2006-01-06 00:20:12 -08002139 raise_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140
2141 /* ok, everything is stopped */
2142 oldpool = conf->r1bio_pool;
2143 conf->r1bio_pool = newpool;
NeilBrown6ea9c072005-06-21 17:17:09 -07002144
2145 for (d=d2=0; d < conf->raid_disks; d++)
2146 if (conf->mirrors[d].rdev) {
2147 conf->mirrors[d].rdev->raid_disk = d2;
2148 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2149 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002150 kfree(conf->mirrors);
2151 conf->mirrors = newmirrors;
2152 kfree(conf->poolinfo);
2153 conf->poolinfo = newpoolinfo;
2154
NeilBrownc04be0a2006-10-03 01:15:53 -07002155 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002156 mddev->degraded += (raid_disks - conf->raid_disks);
NeilBrownc04be0a2006-10-03 01:15:53 -07002157 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002158 conf->raid_disks = mddev->raid_disks = raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08002159 mddev->delta_disks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160
NeilBrown6ea9c072005-06-21 17:17:09 -07002161 conf->last_used = 0; /* just make sure it is in-range */
NeilBrown17999be2006-01-06 00:20:12 -08002162 lower_barrier(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163
2164 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2165 md_wakeup_thread(mddev->thread);
2166
2167 mempool_destroy(oldpool);
2168 return 0;
2169}
2170
NeilBrown500af872005-09-09 16:23:58 -07002171static void raid1_quiesce(mddev_t *mddev, int state)
NeilBrown36fa3062005-09-09 16:23:45 -07002172{
2173 conf_t *conf = mddev_to_conf(mddev);
2174
2175 switch(state) {
NeilBrown9e6603d2005-09-09 16:23:48 -07002176 case 1:
NeilBrown17999be2006-01-06 00:20:12 -08002177 raise_barrier(conf);
NeilBrown36fa3062005-09-09 16:23:45 -07002178 break;
NeilBrown9e6603d2005-09-09 16:23:48 -07002179 case 0:
NeilBrown17999be2006-01-06 00:20:12 -08002180 lower_barrier(conf);
NeilBrown36fa3062005-09-09 16:23:45 -07002181 break;
2182 }
NeilBrown36fa3062005-09-09 16:23:45 -07002183}
2184
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185
NeilBrown2604b702006-01-06 00:20:36 -08002186static struct mdk_personality raid1_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002187{
2188 .name = "raid1",
NeilBrown2604b702006-01-06 00:20:36 -08002189 .level = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002190 .owner = THIS_MODULE,
2191 .make_request = make_request,
2192 .run = run,
2193 .stop = stop,
2194 .status = status,
2195 .error_handler = error,
2196 .hot_add_disk = raid1_add_disk,
2197 .hot_remove_disk= raid1_remove_disk,
2198 .spare_active = raid1_spare_active,
2199 .sync_request = sync_request,
2200 .resize = raid1_resize,
NeilBrown63c70c42006-03-27 01:18:13 -08002201 .check_reshape = raid1_reshape,
NeilBrown36fa3062005-09-09 16:23:45 -07002202 .quiesce = raid1_quiesce,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002203};
2204
2205static int __init raid_init(void)
2206{
NeilBrown2604b702006-01-06 00:20:36 -08002207 return register_md_personality(&raid1_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002208}
2209
2210static void raid_exit(void)
2211{
NeilBrown2604b702006-01-06 00:20:36 -08002212 unregister_md_personality(&raid1_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002213}
2214
2215module_init(raid_init);
2216module_exit(raid_exit);
2217MODULE_LICENSE("GPL");
2218MODULE_ALIAS("md-personality-3"); /* RAID1 */
NeilBrownd9d166c2006-01-06 00:20:51 -08002219MODULE_ALIAS("md-raid1");
NeilBrown2604b702006-01-06 00:20:36 -08002220MODULE_ALIAS("md-level-1");