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md/raid10: move rdev->corrected_errors counting
[linux-2.6-block.git] / drivers / md / raid5.c
CommitLineData
1da177e4
LT		 1/*
2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
16a53ecc 5 * Copyright (C) 2002, 2003 H. Peter Anvin
1da177e4 6 *
16a53ecc
N		 7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
1da177e4
LT		 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
ae3c20cc
N		 21/*
22 * BITMAP UNPLUGGING:
23 *
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
26 * explanation.
27 *
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
7c13edc8
N		 30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
ae3c20cc
N		 32 * new additions.
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
7c13edc8 35 * the number of the batch it will be in. This is seq_flush+1.
ae3c20cc
N		 36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
39 * batch.
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
43 * miss any bits.
44 */
1da177e4 45
bff61975 46#include <linux/blkdev.h>
f6705578 47#include <linux/kthread.h>
f701d589 48#include <linux/raid/pq.h>
91c00924 49#include <linux/async_tx.h>
07a3b417 50#include <linux/async.h>
bff61975 51#include <linux/seq_file.h>
36d1c647 52#include <linux/cpu.h>
5a0e3ad6 53#include <linux/slab.h>
8bda470e 54#include <linux/ratelimit.h>
43b2e5d8 55#include "md.h"
bff61975 56#include "raid5.h"
54071b38 57#include "raid0.h"
ef740c37 58#include "bitmap.h"
72626685 59
1da177e4
LT		 60/*
61 * Stripe cache
62 */
63
64#define NR_STRIPES 256
65#define STRIPE_SIZE PAGE_SIZE
66#define STRIPE_SHIFT (PAGE_SHIFT - 9)
67#define STRIPE_SECTORS (STRIPE_SIZE>>9)
68#define IO_THRESHOLD 1
8b3e6cdc 69#define BYPASS_THRESHOLD 1
fccddba0 70#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
1da177e4
LT		 71#define HASH_MASK (NR_HASH - 1)
72
fccddba0 73#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
1da177e4
LT		 74
75/* bio's attached to a stripe+device for I/O are linked together in bi_sector
76 * order without overlap. There may be several bio's per stripe+device, and
77 * a bio could span several devices.
78 * When walking this list for a particular stripe+device, we must never proceed
79 * beyond a bio that extends past this device, as the next bio might no longer
80 * be valid.
81 * This macro is used to determine the 'next' bio in the list, given the sector
82 * of the current stripe+device
83 */
84#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
85/*
86 * The following can be used to debug the driver
87 */
1da177e4
LT		 88#define RAID5_PARANOIA 1
89#if RAID5_PARANOIA && defined(CONFIG_SMP)
90# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
91#else
92# define CHECK_DEVLOCK()
93#endif
94
45b4233c 95#ifdef DEBUG
1da177e4
LT		 96#define inline
97#define __inline__
98#endif
99
960e739d 100/*
5b99c2ff
JA		 101 * We maintain a biased count of active stripes in the bottom 16 bits of
102 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
960e739d
JA		 103 */
104static inline int raid5_bi_phys_segments(struct bio *bio)
105{
5b99c2ff 106 return bio->bi_phys_segments & 0xffff;
960e739d
JA		 107}
108
109static inline int raid5_bi_hw_segments(struct bio *bio)
110{
5b99c2ff 111 return (bio->bi_phys_segments >> 16) & 0xffff;
960e739d
JA		 112}
113
114static inline int raid5_dec_bi_phys_segments(struct bio *bio)
115{
116 --bio->bi_phys_segments;
117 return raid5_bi_phys_segments(bio);
118}
119
120static inline int raid5_dec_bi_hw_segments(struct bio *bio)
121{
122 unsigned short val = raid5_bi_hw_segments(bio);
123
124 --val;
5b99c2ff 125 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
960e739d
JA		 126 return val;
127}
128
129static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
130{
9b2dc8b6 131 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16);
960e739d
JA		 132}
133
d0dabf7e
N		 134/* Find first data disk in a raid6 stripe */
135static inline int raid6_d0(struct stripe_head *sh)
136{
67cc2b81
N		 137 if (sh->ddf_layout)
138 /* ddf always start from first device */
139 return 0;
140 /* md starts just after Q block */
d0dabf7e
N		 141 if (sh->qd_idx == sh->disks - 1)
142 return 0;
143 else
144 return sh->qd_idx + 1;
145}
16a53ecc
N		 146static inline int raid6_next_disk(int disk, int raid_disks)
147{
148 disk++;
149 return (disk < raid_disks) ? disk : 0;
150}
a4456856 151
d0dabf7e
N		 152/* When walking through the disks in a raid5, starting at raid6_d0,
153 * We need to map each disk to a 'slot', where the data disks are slot
154 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
155 * is raid_disks-1. This help does that mapping.
156 */
67cc2b81
N		 157static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
158 int *count, int syndrome_disks)
d0dabf7e 159{
6629542e 160 int slot = *count;
67cc2b81 161
e4424fee 162 if (sh->ddf_layout)
6629542e 163 (*count)++;
d0dabf7e 164 if (idx == sh->pd_idx)
67cc2b81 165 return syndrome_disks;
d0dabf7e 166 if (idx == sh->qd_idx)
67cc2b81 167 return syndrome_disks + 1;
e4424fee 168 if (!sh->ddf_layout)
6629542e 169 (*count)++;
d0dabf7e
N		 170 return slot;
171}
172
a4456856
DW		 173static void return_io(struct bio *return_bi)
174{
175 struct bio *bi = return_bi;
176 while (bi) {
a4456856
DW		 177
178 return_bi = bi->bi_next;
179 bi->bi_next = NULL;
180 bi->bi_size = 0;
0e13fe23 181 bio_endio(bi, 0);
a4456856
DW		 182 bi = return_bi;
183 }
184}
185
1da177e4
LT		 186static void print_raid5_conf (raid5_conf_t *conf);
187
600aa109
DW		 188static int stripe_operations_active(struct stripe_head *sh)
189{
190 return sh->check_state || sh->reconstruct_state ||
191 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
192 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
193}
194
858119e1 195static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
1da177e4
LT		 196{
197 if (atomic_dec_and_test(&sh->count)) {
78bafebd
ES		 198 BUG_ON(!list_empty(&sh->lru));
199 BUG_ON(atomic_read(&conf->active_stripes)==0);
1da177e4 200 if (test_bit(STRIPE_HANDLE, &sh->state)) {
482c0834 201 if (test_bit(STRIPE_DELAYED, &sh->state))
1da177e4 202 list_add_tail(&sh->lru, &conf->delayed_list);
482c0834
N		 203 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
204 sh->bm_seq - conf->seq_write > 0)
72626685 205 list_add_tail(&sh->lru, &conf->bitmap_list);
482c0834 206 else {
72626685 207 clear_bit(STRIPE_BIT_DELAY, &sh->state);
1da177e4 208 list_add_tail(&sh->lru, &conf->handle_list);
72626685 209 }
1da177e4
LT		 210 md_wakeup_thread(conf->mddev->thread);
211 } else {
600aa109 212 BUG_ON(stripe_operations_active(sh));
1da177e4
LT		 213 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
214 atomic_dec(&conf->preread_active_stripes);
215 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
216 md_wakeup_thread(conf->mddev->thread);
217 }
1da177e4 218 atomic_dec(&conf->active_stripes);
ccfcc3c1
N		 219 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
220 list_add_tail(&sh->lru, &conf->inactive_list);
1da177e4 221 wake_up(&conf->wait_for_stripe);
46031f9a
RBJ		 222 if (conf->retry_read_aligned)
223 md_wakeup_thread(conf->mddev->thread);
ccfcc3c1 224 }
1da177e4
LT		 225 }
226 }
227}
d0dabf7e 228
1da177e4
LT		 229static void release_stripe(struct stripe_head *sh)
230{
231 raid5_conf_t *conf = sh->raid_conf;
232 unsigned long flags;
16a53ecc 233
1da177e4
LT		 234 spin_lock_irqsave(&conf->device_lock, flags);
235 __release_stripe(conf, sh);
236 spin_unlock_irqrestore(&conf->device_lock, flags);
237}
238
fccddba0 239static inline void remove_hash(struct stripe_head *sh)
1da177e4 240{
45b4233c
DW		 241 pr_debug("remove_hash(), stripe %llu\n",
242 (unsigned long long)sh->sector);
1da177e4 243
fccddba0 244 hlist_del_init(&sh->hash);
1da177e4
LT		 245}
246
16a53ecc 247static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
1da177e4 248{
fccddba0 249 struct hlist_head *hp = stripe_hash(conf, sh->sector);
1da177e4 250
45b4233c
DW		 251 pr_debug("insert_hash(), stripe %llu\n",
252 (unsigned long long)sh->sector);
1da177e4
LT		 253
254 CHECK_DEVLOCK();
fccddba0 255 hlist_add_head(&sh->hash, hp);
1da177e4
LT		 256}
257
258
259/* find an idle stripe, make sure it is unhashed, and return it. */
260static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
261{
262 struct stripe_head *sh = NULL;
263 struct list_head *first;
264
265 CHECK_DEVLOCK();
266 if (list_empty(&conf->inactive_list))
267 goto out;
268 first = conf->inactive_list.next;
269 sh = list_entry(first, struct stripe_head, lru);
270 list_del_init(first);
271 remove_hash(sh);
272 atomic_inc(&conf->active_stripes);
273out:
274 return sh;
275}
276
e4e11e38 277static void shrink_buffers(struct stripe_head *sh)
1da177e4
LT		 278{
279 struct page *p;
280 int i;
e4e11e38 281 int num = sh->raid_conf->pool_size;
1da177e4 282
e4e11e38 283 for (i = 0; i < num ; i++) {
1da177e4
LT		 284 p = sh->dev[i].page;
285 if (!p)
286 continue;
287 sh->dev[i].page = NULL;
2d1f3b5d 288 put_page(p);
1da177e4
LT		 289 }
290}
291
e4e11e38 292static int grow_buffers(struct stripe_head *sh)
1da177e4
LT		 293{
294 int i;
e4e11e38 295 int num = sh->raid_conf->pool_size;
1da177e4 296
e4e11e38 297 for (i = 0; i < num; i++) {
1da177e4
LT		 298 struct page *page;
299
300 if (!(page = alloc_page(GFP_KERNEL))) {
301 return 1;
302 }
303 sh->dev[i].page = page;
304 }
305 return 0;
306}
307
784052ec 308static void raid5_build_block(struct stripe_head *sh, int i, int previous);
911d4ee8
N		 309static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
310 struct stripe_head *sh);
1da177e4 311
b5663ba4 312static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
1da177e4
LT		 313{
314 raid5_conf_t *conf = sh->raid_conf;
7ecaa1e6 315 int i;
1da177e4 316
78bafebd
ES		 317 BUG_ON(atomic_read(&sh->count) != 0);
318 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
600aa109 319 BUG_ON(stripe_operations_active(sh));
d84e0f10 320
1da177e4 321 CHECK_DEVLOCK();
45b4233c 322 pr_debug("init_stripe called, stripe %llu\n",
1da177e4
LT		 323 (unsigned long long)sh->sector);
324
325 remove_hash(sh);
16a53ecc 326
86b42c71 327 sh->generation = conf->generation - previous;
b5663ba4 328 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
1da177e4 329 sh->sector = sector;
911d4ee8 330 stripe_set_idx(sector, conf, previous, sh);
1da177e4
LT		 331 sh->state = 0;
332
7ecaa1e6
N		 333
334 for (i = sh->disks; i--; ) {
1da177e4
LT		 335 struct r5dev *dev = &sh->dev[i];
336
d84e0f10 337 if (dev->toread || dev->read || dev->towrite || dev->written ||
1da177e4 338 test_bit(R5_LOCKED, &dev->flags)) {
d84e0f10 339 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
1da177e4 340 (unsigned long long)sh->sector, i, dev->toread,
d84e0f10 341 dev->read, dev->towrite, dev->written,
1da177e4
LT		 342 test_bit(R5_LOCKED, &dev->flags));
343 BUG();
344 }
345 dev->flags = 0;
784052ec 346 raid5_build_block(sh, i, previous);
1da177e4
LT		 347 }
348 insert_hash(conf, sh);
349}
350
86b42c71
N		 351static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
352 short generation)
1da177e4
LT		 353{
354 struct stripe_head *sh;
fccddba0 355 struct hlist_node *hn;
1da177e4
LT		 356
357 CHECK_DEVLOCK();
45b4233c 358 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
fccddba0 359 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
86b42c71 360 if (sh->sector == sector && sh->generation == generation)
1da177e4 361 return sh;
45b4233c 362 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
1da177e4
LT		 363 return NULL;
364}
365
674806d6
N		 366/*
367 * Need to check if array has failed when deciding whether to:
368 * - start an array
369 * - remove non-faulty devices
370 * - add a spare
371 * - allow a reshape
372 * This determination is simple when no reshape is happening.
373 * However if there is a reshape, we need to carefully check
374 * both the before and after sections.
375 * This is because some failed devices may only affect one
376 * of the two sections, and some non-in_sync devices may
377 * be insync in the section most affected by failed devices.
378 */
379static int has_failed(raid5_conf_t *conf)
380{
381 int degraded;
382 int i;
383 if (conf->mddev->reshape_position == MaxSector)
384 return conf->mddev->degraded > conf->max_degraded;
385
386 rcu_read_lock();
387 degraded = 0;
388 for (i = 0; i < conf->previous_raid_disks; i++) {
389 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
390 if (!rdev || test_bit(Faulty, &rdev->flags))
391 degraded++;
392 else if (test_bit(In_sync, &rdev->flags))
393 ;
394 else
395 /* not in-sync or faulty.
396 * If the reshape increases the number of devices,
397 * this is being recovered by the reshape, so
398 * this 'previous' section is not in_sync.
399 * If the number of devices is being reduced however,
400 * the device can only be part of the array if
401 * we are reverting a reshape, so this section will
402 * be in-sync.
403 */
404 if (conf->raid_disks >= conf->previous_raid_disks)
405 degraded++;
406 }
407 rcu_read_unlock();
408 if (degraded > conf->max_degraded)
409 return 1;
410 rcu_read_lock();
411 degraded = 0;
412 for (i = 0; i < conf->raid_disks; i++) {
413 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
414 if (!rdev || test_bit(Faulty, &rdev->flags))
415 degraded++;
416 else if (test_bit(In_sync, &rdev->flags))
417 ;
418 else
419 /* not in-sync or faulty.
420 * If reshape increases the number of devices, this
421 * section has already been recovered, else it
422 * almost certainly hasn't.
423 */
424 if (conf->raid_disks <= conf->previous_raid_disks)
425 degraded++;
426 }
427 rcu_read_unlock();
428 if (degraded > conf->max_degraded)
429 return 1;
430 return 0;
431}
432
b5663ba4
N		 433static struct stripe_head *
434get_active_stripe(raid5_conf_t *conf, sector_t sector,
a8c906ca 435 int previous, int noblock, int noquiesce)
1da177e4
LT		 436{
437 struct stripe_head *sh;
438
45b4233c 439 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
1da177e4
LT		 440
441 spin_lock_irq(&conf->device_lock);
442
443 do {
72626685 444 wait_event_lock_irq(conf->wait_for_stripe,
a8c906ca 445 conf->quiesce == 0 || noquiesce,
72626685 446 conf->device_lock, /* nothing */);
86b42c71 447 sh = __find_stripe(conf, sector, conf->generation - previous);
1da177e4
LT		 448 if (!sh) {
449 if (!conf->inactive_blocked)
450 sh = get_free_stripe(conf);
451 if (noblock && sh == NULL)
452 break;
453 if (!sh) {
454 conf->inactive_blocked = 1;
455 wait_event_lock_irq(conf->wait_for_stripe,
456 !list_empty(&conf->inactive_list) &&
5036805b
N		 457 (atomic_read(&conf->active_stripes)
458 < (conf->max_nr_stripes *3/4)
1da177e4
LT		 459 || !conf->inactive_blocked),
460 conf->device_lock,
7c13edc8 461 );
1da177e4
LT		 462 conf->inactive_blocked = 0;
463 } else
b5663ba4 464 init_stripe(sh, sector, previous);
1da177e4
LT		 465 } else {
466 if (atomic_read(&sh->count)) {
ab69ae12
N		 467 BUG_ON(!list_empty(&sh->lru)
468 && !test_bit(STRIPE_EXPANDING, &sh->state));
1da177e4
LT		 469 } else {
470 if (!test_bit(STRIPE_HANDLE, &sh->state))
471 atomic_inc(&conf->active_stripes);
ff4e8d9a
N		 472 if (list_empty(&sh->lru) &&
473 !test_bit(STRIPE_EXPANDING, &sh->state))
16a53ecc
N		 474 BUG();
475 list_del_init(&sh->lru);
1da177e4
LT		 476 }
477 }
478 } while (sh == NULL);
479
480 if (sh)
481 atomic_inc(&sh->count);
482
483 spin_unlock_irq(&conf->device_lock);
484 return sh;
485}
486
6712ecf8
N		 487static void
488raid5_end_read_request(struct bio *bi, int error);
489static void
490raid5_end_write_request(struct bio *bi, int error);
91c00924 491
c4e5ac0a 492static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
91c00924
DW		 493{
494 raid5_conf_t *conf = sh->raid_conf;
495 int i, disks = sh->disks;
496
497 might_sleep();
498
499 for (i = disks; i--; ) {
500 int rw;
501 struct bio *bi;
502 mdk_rdev_t *rdev;
e9c7469b
TH		 503 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
504 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
505 rw = WRITE_FUA;
506 else
507 rw = WRITE;
508 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
91c00924
DW		 509 rw = READ;
510 else
511 continue;
512
513 bi = &sh->dev[i].req;
514
515 bi->bi_rw = rw;
b062962e 516 if (rw & WRITE)
91c00924
DW		 517 bi->bi_end_io = raid5_end_write_request;
518 else
519 bi->bi_end_io = raid5_end_read_request;
520
521 rcu_read_lock();
522 rdev = rcu_dereference(conf->disks[i].rdev);
523 if (rdev && test_bit(Faulty, &rdev->flags))
524 rdev = NULL;
525 if (rdev)
526 atomic_inc(&rdev->nr_pending);
527 rcu_read_unlock();
528
529 if (rdev) {
c4e5ac0a 530 if (s->syncing || s->expanding || s->expanded)
91c00924
DW		 531 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
532
2b7497f0
DW		 533 set_bit(STRIPE_IO_STARTED, &sh->state);
534
91c00924
DW		 535 bi->bi_bdev = rdev->bdev;
536 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
e46b272b 537 __func__, (unsigned long long)sh->sector,
91c00924
DW		 538 bi->bi_rw, i);
539 atomic_inc(&sh->count);
540 bi->bi_sector = sh->sector + rdev->data_offset;
541 bi->bi_flags = 1 << BIO_UPTODATE;
542 bi->bi_vcnt = 1;
543 bi->bi_max_vecs = 1;
544 bi->bi_idx = 0;
545 bi->bi_io_vec = &sh->dev[i].vec;
546 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
547 bi->bi_io_vec[0].bv_offset = 0;
548 bi->bi_size = STRIPE_SIZE;
549 bi->bi_next = NULL;
91c00924
DW		 550 generic_make_request(bi);
551 } else {
b062962e 552 if (rw & WRITE)
91c00924
DW		 553 set_bit(STRIPE_DEGRADED, &sh->state);
554 pr_debug("skip op %ld on disc %d for sector %llu\n",
555 bi->bi_rw, i, (unsigned long long)sh->sector);
556 clear_bit(R5_LOCKED, &sh->dev[i].flags);
557 set_bit(STRIPE_HANDLE, &sh->state);
558 }
559 }
560}
561
562static struct dma_async_tx_descriptor *
563async_copy_data(int frombio, struct bio *bio, struct page *page,
564 sector_t sector, struct dma_async_tx_descriptor *tx)
565{
566 struct bio_vec *bvl;
567 struct page *bio_page;
568 int i;
569 int page_offset;
a08abd8c 570 struct async_submit_ctl submit;
0403e382 571 enum async_tx_flags flags = 0;
91c00924
DW		 572
573 if (bio->bi_sector >= sector)
574 page_offset = (signed)(bio->bi_sector - sector) * 512;
575 else
576 page_offset = (signed)(sector - bio->bi_sector) * -512;
a08abd8c 577
0403e382
DW		 578 if (frombio)
579 flags |= ASYNC_TX_FENCE;
580 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
581
91c00924 582 bio_for_each_segment(bvl, bio, i) {
fcde9075 583 int len = bvl->bv_len;
91c00924
DW		 584 int clen;
585 int b_offset = 0;
586
587 if (page_offset < 0) {
588 b_offset = -page_offset;
589 page_offset += b_offset;
590 len -= b_offset;
591 }
592
593 if (len > 0 && page_offset + len > STRIPE_SIZE)
594 clen = STRIPE_SIZE - page_offset;
595 else
596 clen = len;
597
598 if (clen > 0) {
fcde9075
NK		 599 b_offset += bvl->bv_offset;
600 bio_page = bvl->bv_page;
91c00924
DW		 601 if (frombio)
602 tx = async_memcpy(page, bio_page, page_offset,
a08abd8c 603 b_offset, clen, &submit);
91c00924
DW		 604 else
605 tx = async_memcpy(bio_page, page, b_offset,
a08abd8c 606 page_offset, clen, &submit);
91c00924 607 }
a08abd8c
DW		 608 /* chain the operations */
609 submit.depend_tx = tx;
610
91c00924
DW		 611 if (clen < len) /* hit end of page */
612 break;
613 page_offset += len;
614 }
615
616 return tx;
617}
618
619static void ops_complete_biofill(void *stripe_head_ref)
620{
621 struct stripe_head *sh = stripe_head_ref;
622 struct bio *return_bi = NULL;
623 raid5_conf_t *conf = sh->raid_conf;
e4d84909 624 int i;
91c00924 625
e46b272b 626 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 627 (unsigned long long)sh->sector);
628
629 /* clear completed biofills */
83de75cc 630 spin_lock_irq(&conf->device_lock);
91c00924
DW		 631 for (i = sh->disks; i--; ) {
632 struct r5dev *dev = &sh->dev[i];
91c00924
DW		 633
634 /* acknowledge completion of a biofill operation */
e4d84909
DW		 635 /* and check if we need to reply to a read request,
636 * new R5_Wantfill requests are held off until
83de75cc 637 * !STRIPE_BIOFILL_RUN
e4d84909
DW		 638 */
639 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
91c00924 640 struct bio *rbi, *rbi2;
91c00924 641
91c00924
DW		 642 BUG_ON(!dev->read);
643 rbi = dev->read;
644 dev->read = NULL;
645 while (rbi && rbi->bi_sector <
646 dev->sector + STRIPE_SECTORS) {
647 rbi2 = r5_next_bio(rbi, dev->sector);
960e739d 648 if (!raid5_dec_bi_phys_segments(rbi)) {
91c00924
DW		 649 rbi->bi_next = return_bi;
650 return_bi = rbi;
651 }
91c00924
DW		 652 rbi = rbi2;
653 }
654 }
655 }
83de75cc
DW		 656 spin_unlock_irq(&conf->device_lock);
657 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
91c00924
DW		 658
659 return_io(return_bi);
660
e4d84909 661 set_bit(STRIPE_HANDLE, &sh->state);
91c00924
DW		 662 release_stripe(sh);
663}
664
665static void ops_run_biofill(struct stripe_head *sh)
666{
667 struct dma_async_tx_descriptor *tx = NULL;
668 raid5_conf_t *conf = sh->raid_conf;
a08abd8c 669 struct async_submit_ctl submit;
91c00924
DW		 670 int i;
671
e46b272b 672 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 673 (unsigned long long)sh->sector);
674
675 for (i = sh->disks; i--; ) {
676 struct r5dev *dev = &sh->dev[i];
677 if (test_bit(R5_Wantfill, &dev->flags)) {
678 struct bio *rbi;
679 spin_lock_irq(&conf->device_lock);
680 dev->read = rbi = dev->toread;
681 dev->toread = NULL;
682 spin_unlock_irq(&conf->device_lock);
683 while (rbi && rbi->bi_sector <
684 dev->sector + STRIPE_SECTORS) {
685 tx = async_copy_data(0, rbi, dev->page,
686 dev->sector, tx);
687 rbi = r5_next_bio(rbi, dev->sector);
688 }
689 }
690 }
691
692 atomic_inc(&sh->count);
a08abd8c
DW		 693 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
694 async_trigger_callback(&submit);
91c00924
DW		 695}
696
4e7d2c0a 697static void mark_target_uptodate(struct stripe_head *sh, int target)
91c00924 698{
4e7d2c0a 699 struct r5dev *tgt;
91c00924 700
4e7d2c0a
DW		 701 if (target < 0)
702 return;
91c00924 703
4e7d2c0a 704 tgt = &sh->dev[target];
91c00924
DW		 705 set_bit(R5_UPTODATE, &tgt->flags);
706 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
707 clear_bit(R5_Wantcompute, &tgt->flags);
4e7d2c0a
DW		 708}
709
ac6b53b6 710static void ops_complete_compute(void *stripe_head_ref)
91c00924
DW		 711{
712 struct stripe_head *sh = stripe_head_ref;
91c00924 713
e46b272b 714 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 715 (unsigned long long)sh->sector);
716
ac6b53b6 717 /* mark the computed target(s) as uptodate */
4e7d2c0a 718 mark_target_uptodate(sh, sh->ops.target);
ac6b53b6 719 mark_target_uptodate(sh, sh->ops.target2);
4e7d2c0a 720
ecc65c9b
DW		 721 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
722 if (sh->check_state == check_state_compute_run)
723 sh->check_state = check_state_compute_result;
91c00924
DW		 724 set_bit(STRIPE_HANDLE, &sh->state);
725 release_stripe(sh);
726}
727
d6f38f31
DW		 728/* return a pointer to the address conversion region of the scribble buffer */
729static addr_conv_t *to_addr_conv(struct stripe_head *sh,
730 struct raid5_percpu *percpu)
731{
732 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
733}
734
735static struct dma_async_tx_descriptor *
736ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 737{
91c00924 738 int disks = sh->disks;
d6f38f31 739 struct page **xor_srcs = percpu->scribble;
91c00924
DW		 740 int target = sh->ops.target;
741 struct r5dev *tgt = &sh->dev[target];
742 struct page *xor_dest = tgt->page;
743 int count = 0;
744 struct dma_async_tx_descriptor *tx;
a08abd8c 745 struct async_submit_ctl submit;
91c00924
DW		 746 int i;
747
748 pr_debug("%s: stripe %llu block: %d\n",
e46b272b 749 __func__, (unsigned long long)sh->sector, target);
91c00924
DW		 750 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
751
752 for (i = disks; i--; )
753 if (i != target)
754 xor_srcs[count++] = sh->dev[i].page;
755
756 atomic_inc(&sh->count);
757
0403e382 758 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
ac6b53b6 759 ops_complete_compute, sh, to_addr_conv(sh, percpu));
91c00924 760 if (unlikely(count == 1))
a08abd8c 761 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
91c00924 762 else
a08abd8c 763 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924 764
91c00924
DW		 765 return tx;
766}
767
ac6b53b6
DW		 768/* set_syndrome_sources - populate source buffers for gen_syndrome
769 * @srcs - (struct page *) array of size sh->disks
770 * @sh - stripe_head to parse
771 *
772 * Populates srcs in proper layout order for the stripe and returns the
773 * 'count' of sources to be used in a call to async_gen_syndrome. The P
774 * destination buffer is recorded in srcs[count] and the Q destination
775 * is recorded in srcs[count+1]].
776 */
777static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
778{
779 int disks = sh->disks;
780 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
781 int d0_idx = raid6_d0(sh);
782 int count;
783 int i;
784
785 for (i = 0; i < disks; i++)
5dd33c9a 786 srcs[i] = NULL;
ac6b53b6
DW		 787
788 count = 0;
789 i = d0_idx;
790 do {
791 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
792
793 srcs[slot] = sh->dev[i].page;
794 i = raid6_next_disk(i, disks);
795 } while (i != d0_idx);
ac6b53b6 796
e4424fee 797 return syndrome_disks;
ac6b53b6
DW		 798}
799
800static struct dma_async_tx_descriptor *
801ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
802{
803 int disks = sh->disks;
804 struct page **blocks = percpu->scribble;
805 int target;
806 int qd_idx = sh->qd_idx;
807 struct dma_async_tx_descriptor *tx;
808 struct async_submit_ctl submit;
809 struct r5dev *tgt;
810 struct page *dest;
811 int i;
812 int count;
813
814 if (sh->ops.target < 0)
815 target = sh->ops.target2;
816 else if (sh->ops.target2 < 0)
817 target = sh->ops.target;
91c00924 818 else
ac6b53b6
DW		 819 /* we should only have one valid target */
820 BUG();
821 BUG_ON(target < 0);
822 pr_debug("%s: stripe %llu block: %d\n",
823 __func__, (unsigned long long)sh->sector, target);
824
825 tgt = &sh->dev[target];
826 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
827 dest = tgt->page;
828
829 atomic_inc(&sh->count);
830
831 if (target == qd_idx) {
832 count = set_syndrome_sources(blocks, sh);
833 blocks[count] = NULL; /* regenerating p is not necessary */
834 BUG_ON(blocks[count+1] != dest); /* q should already be set */
0403e382
DW		 835 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
836 ops_complete_compute, sh,
ac6b53b6
DW		 837 to_addr_conv(sh, percpu));
838 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
839 } else {
840 /* Compute any data- or p-drive using XOR */
841 count = 0;
842 for (i = disks; i-- ; ) {
843 if (i == target || i == qd_idx)
844 continue;
845 blocks[count++] = sh->dev[i].page;
846 }
847
0403e382
DW		 848 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
849 NULL, ops_complete_compute, sh,
ac6b53b6
DW		 850 to_addr_conv(sh, percpu));
851 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
852 }
91c00924 853
91c00924
DW		 854 return tx;
855}
856
ac6b53b6
DW		 857static struct dma_async_tx_descriptor *
858ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
859{
860 int i, count, disks = sh->disks;
861 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
862 int d0_idx = raid6_d0(sh);
863 int faila = -1, failb = -1;
864 int target = sh->ops.target;
865 int target2 = sh->ops.target2;
866 struct r5dev *tgt = &sh->dev[target];
867 struct r5dev *tgt2 = &sh->dev[target2];
868 struct dma_async_tx_descriptor *tx;
869 struct page **blocks = percpu->scribble;
870 struct async_submit_ctl submit;
871
872 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
873 __func__, (unsigned long long)sh->sector, target, target2);
874 BUG_ON(target < 0 || target2 < 0);
875 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
876 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
877
6c910a78 878 /* we need to open-code set_syndrome_sources to handle the
ac6b53b6
DW		 879 * slot number conversion for 'faila' and 'failb'
880 */
881 for (i = 0; i < disks ; i++)
5dd33c9a 882 blocks[i] = NULL;
ac6b53b6
DW		 883 count = 0;
884 i = d0_idx;
885 do {
886 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
887
888 blocks[slot] = sh->dev[i].page;
889
890 if (i == target)
891 faila = slot;
892 if (i == target2)
893 failb = slot;
894 i = raid6_next_disk(i, disks);
895 } while (i != d0_idx);
ac6b53b6
DW		 896
897 BUG_ON(faila == failb);
898 if (failb < faila)
899 swap(faila, failb);
900 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
901 __func__, (unsigned long long)sh->sector, faila, failb);
902
903 atomic_inc(&sh->count);
904
905 if (failb == syndrome_disks+1) {
906 /* Q disk is one of the missing disks */
907 if (faila == syndrome_disks) {
908 /* Missing P+Q, just recompute */
0403e382
DW		 909 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
910 ops_complete_compute, sh,
911 to_addr_conv(sh, percpu));
e4424fee 912 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
ac6b53b6
DW		 913 STRIPE_SIZE, &submit);
914 } else {
915 struct page *dest;
916 int data_target;
917 int qd_idx = sh->qd_idx;
918
919 /* Missing D+Q: recompute D from P, then recompute Q */
920 if (target == qd_idx)
921 data_target = target2;
922 else
923 data_target = target;
924
925 count = 0;
926 for (i = disks; i-- ; ) {
927 if (i == data_target || i == qd_idx)
928 continue;
929 blocks[count++] = sh->dev[i].page;
930 }
931 dest = sh->dev[data_target].page;
0403e382
DW		 932 init_async_submit(&submit,
933 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
934 NULL, NULL, NULL,
935 to_addr_conv(sh, percpu));
ac6b53b6
DW		 936 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
937 &submit);
938
939 count = set_syndrome_sources(blocks, sh);
0403e382
DW		 940 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
941 ops_complete_compute, sh,
942 to_addr_conv(sh, percpu));
ac6b53b6
DW		 943 return async_gen_syndrome(blocks, 0, count+2,
944 STRIPE_SIZE, &submit);
945 }
ac6b53b6 946 } else {
6c910a78
DW		 947 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
948 ops_complete_compute, sh,
949 to_addr_conv(sh, percpu));
950 if (failb == syndrome_disks) {
951 /* We're missing D+P. */
952 return async_raid6_datap_recov(syndrome_disks+2,
953 STRIPE_SIZE, faila,
954 blocks, &submit);
955 } else {
956 /* We're missing D+D. */
957 return async_raid6_2data_recov(syndrome_disks+2,
958 STRIPE_SIZE, faila, failb,
959 blocks, &submit);
960 }
ac6b53b6
DW		 961 }
962}
963
964
91c00924
DW		 965static void ops_complete_prexor(void *stripe_head_ref)
966{
967 struct stripe_head *sh = stripe_head_ref;
968
e46b272b 969 pr_debug("%s: stripe %llu\n", __func__,
91c00924 970 (unsigned long long)sh->sector);
91c00924
DW		 971}
972
973static struct dma_async_tx_descriptor *
d6f38f31
DW		 974ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
975 struct dma_async_tx_descriptor *tx)
91c00924 976{
91c00924 977 int disks = sh->disks;
d6f38f31 978 struct page **xor_srcs = percpu->scribble;
91c00924 979 int count = 0, pd_idx = sh->pd_idx, i;
a08abd8c 980 struct async_submit_ctl submit;
91c00924
DW		 981
982 /* existing parity data subtracted */
983 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
984
e46b272b 985 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 986 (unsigned long long)sh->sector);
987
988 for (i = disks; i--; ) {
989 struct r5dev *dev = &sh->dev[i];
990 /* Only process blocks that are known to be uptodate */
d8ee0728 991 if (test_bit(R5_Wantdrain, &dev->flags))
91c00924
DW		 992 xor_srcs[count++] = dev->page;
993 }
994
0403e382 995 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
d6f38f31 996 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
a08abd8c 997 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 998
999 return tx;
1000}
1001
1002static struct dma_async_tx_descriptor *
d8ee0728 1003ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
91c00924
DW		 1004{
1005 int disks = sh->disks;
d8ee0728 1006 int i;
91c00924 1007
e46b272b 1008 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1009 (unsigned long long)sh->sector);
1010
1011 for (i = disks; i--; ) {
1012 struct r5dev *dev = &sh->dev[i];
1013 struct bio *chosen;
91c00924 1014
d8ee0728 1015 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
91c00924
DW		 1016 struct bio *wbi;
1017
cbe47ec5 1018 spin_lock_irq(&sh->raid_conf->device_lock);
91c00924
DW		 1019 chosen = dev->towrite;
1020 dev->towrite = NULL;
1021 BUG_ON(dev->written);
1022 wbi = dev->written = chosen;
cbe47ec5 1023 spin_unlock_irq(&sh->raid_conf->device_lock);
91c00924
DW		 1024
1025 while (wbi && wbi->bi_sector <
1026 dev->sector + STRIPE_SECTORS) {
e9c7469b
TH		 1027 if (wbi->bi_rw & REQ_FUA)
1028 set_bit(R5_WantFUA, &dev->flags);
91c00924
DW		 1029 tx = async_copy_data(1, wbi, dev->page,
1030 dev->sector, tx);
1031 wbi = r5_next_bio(wbi, dev->sector);
1032 }
1033 }
1034 }
1035
1036 return tx;
1037}
1038
ac6b53b6 1039static void ops_complete_reconstruct(void *stripe_head_ref)
91c00924
DW		 1040{
1041 struct stripe_head *sh = stripe_head_ref;
ac6b53b6
DW		 1042 int disks = sh->disks;
1043 int pd_idx = sh->pd_idx;
1044 int qd_idx = sh->qd_idx;
1045 int i;
e9c7469b 1046 bool fua = false;
91c00924 1047
e46b272b 1048 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1049 (unsigned long long)sh->sector);
1050
e9c7469b
TH		 1051 for (i = disks; i--; )
1052 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1053
91c00924
DW		 1054 for (i = disks; i--; ) {
1055 struct r5dev *dev = &sh->dev[i];
ac6b53b6 1056
e9c7469b 1057 if (dev->written || i == pd_idx || i == qd_idx) {
91c00924 1058 set_bit(R5_UPTODATE, &dev->flags);
e9c7469b
TH		 1059 if (fua)
1060 set_bit(R5_WantFUA, &dev->flags);
1061 }
91c00924
DW		 1062 }
1063
d8ee0728
DW		 1064 if (sh->reconstruct_state == reconstruct_state_drain_run)
1065 sh->reconstruct_state = reconstruct_state_drain_result;
1066 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1067 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1068 else {
1069 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1070 sh->reconstruct_state = reconstruct_state_result;
1071 }
91c00924
DW		 1072
1073 set_bit(STRIPE_HANDLE, &sh->state);
1074 release_stripe(sh);
1075}
1076
1077static void
ac6b53b6
DW		 1078ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1079 struct dma_async_tx_descriptor *tx)
91c00924 1080{
91c00924 1081 int disks = sh->disks;
d6f38f31 1082 struct page **xor_srcs = percpu->scribble;
a08abd8c 1083 struct async_submit_ctl submit;
91c00924
DW		 1084 int count = 0, pd_idx = sh->pd_idx, i;
1085 struct page *xor_dest;
d8ee0728 1086 int prexor = 0;
91c00924 1087 unsigned long flags;
91c00924 1088
e46b272b 1089 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1090 (unsigned long long)sh->sector);
1091
1092 /* check if prexor is active which means only process blocks
1093 * that are part of a read-modify-write (written)
1094 */
d8ee0728
DW		 1095 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1096 prexor = 1;
91c00924
DW		 1097 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1098 for (i = disks; i--; ) {
1099 struct r5dev *dev = &sh->dev[i];
1100 if (dev->written)
1101 xor_srcs[count++] = dev->page;
1102 }
1103 } else {
1104 xor_dest = sh->dev[pd_idx].page;
1105 for (i = disks; i--; ) {
1106 struct r5dev *dev = &sh->dev[i];
1107 if (i != pd_idx)
1108 xor_srcs[count++] = dev->page;
1109 }
1110 }
1111
91c00924
DW		 1112 /* 1/ if we prexor'd then the dest is reused as a source
1113 * 2/ if we did not prexor then we are redoing the parity
1114 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1115 * for the synchronous xor case
1116 */
88ba2aa5 1117 flags = ASYNC_TX_ACK |
91c00924
DW		 1118 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1119
1120 atomic_inc(&sh->count);
1121
ac6b53b6 1122 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
d6f38f31 1123 to_addr_conv(sh, percpu));
a08abd8c
DW		 1124 if (unlikely(count == 1))
1125 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1126 else
1127 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 1128}
1129
ac6b53b6
DW		 1130static void
1131ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1132 struct dma_async_tx_descriptor *tx)
1133{
1134 struct async_submit_ctl submit;
1135 struct page **blocks = percpu->scribble;
1136 int count;
1137
1138 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1139
1140 count = set_syndrome_sources(blocks, sh);
1141
1142 atomic_inc(&sh->count);
1143
1144 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1145 sh, to_addr_conv(sh, percpu));
1146 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
91c00924
DW		 1147}
1148
1149static void ops_complete_check(void *stripe_head_ref)
1150{
1151 struct stripe_head *sh = stripe_head_ref;
91c00924 1152
e46b272b 1153 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1154 (unsigned long long)sh->sector);
1155
ecc65c9b 1156 sh->check_state = check_state_check_result;
91c00924
DW		 1157 set_bit(STRIPE_HANDLE, &sh->state);
1158 release_stripe(sh);
1159}
1160
ac6b53b6 1161static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 1162{
91c00924 1163 int disks = sh->disks;
ac6b53b6
DW		 1164 int pd_idx = sh->pd_idx;
1165 int qd_idx = sh->qd_idx;
1166 struct page *xor_dest;
d6f38f31 1167 struct page **xor_srcs = percpu->scribble;
91c00924 1168 struct dma_async_tx_descriptor *tx;
a08abd8c 1169 struct async_submit_ctl submit;
ac6b53b6
DW		 1170 int count;
1171 int i;
91c00924 1172
e46b272b 1173 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1174 (unsigned long long)sh->sector);
1175
ac6b53b6
DW		 1176 count = 0;
1177 xor_dest = sh->dev[pd_idx].page;
1178 xor_srcs[count++] = xor_dest;
91c00924 1179 for (i = disks; i--; ) {
ac6b53b6
DW		 1180 if (i == pd_idx || i == qd_idx)
1181 continue;
1182 xor_srcs[count++] = sh->dev[i].page;
91c00924
DW		 1183 }
1184
d6f38f31
DW		 1185 init_async_submit(&submit, 0, NULL, NULL, NULL,
1186 to_addr_conv(sh, percpu));
099f53cb 1187 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
a08abd8c 1188 &sh->ops.zero_sum_result, &submit);
91c00924 1189
91c00924 1190 atomic_inc(&sh->count);
a08abd8c
DW		 1191 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1192 tx = async_trigger_callback(&submit);
91c00924
DW		 1193}
1194
ac6b53b6
DW		 1195static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1196{
1197 struct page **srcs = percpu->scribble;
1198 struct async_submit_ctl submit;
1199 int count;
1200
1201 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1202 (unsigned long long)sh->sector, checkp);
1203
1204 count = set_syndrome_sources(srcs, sh);
1205 if (!checkp)
1206 srcs[count] = NULL;
91c00924 1207
91c00924 1208 atomic_inc(&sh->count);
ac6b53b6
DW		 1209 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1210 sh, to_addr_conv(sh, percpu));
1211 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1212 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
91c00924
DW		 1213}
1214
417b8d4a 1215static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
91c00924
DW		 1216{
1217 int overlap_clear = 0, i, disks = sh->disks;
1218 struct dma_async_tx_descriptor *tx = NULL;
d6f38f31 1219 raid5_conf_t *conf = sh->raid_conf;
ac6b53b6 1220 int level = conf->level;
d6f38f31
DW		 1221 struct raid5_percpu *percpu;
1222 unsigned long cpu;
91c00924 1223
d6f38f31
DW		 1224 cpu = get_cpu();
1225 percpu = per_cpu_ptr(conf->percpu, cpu);
83de75cc 1226 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
91c00924
DW		 1227 ops_run_biofill(sh);
1228 overlap_clear++;
1229 }
1230
7b3a871e 1231 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
ac6b53b6
DW		 1232 if (level < 6)
1233 tx = ops_run_compute5(sh, percpu);
1234 else {
1235 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1236 tx = ops_run_compute6_1(sh, percpu);
1237 else
1238 tx = ops_run_compute6_2(sh, percpu);
1239 }
1240 /* terminate the chain if reconstruct is not set to be run */
1241 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
7b3a871e
DW		 1242 async_tx_ack(tx);
1243 }
91c00924 1244
600aa109 1245 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
d6f38f31 1246 tx = ops_run_prexor(sh, percpu, tx);
91c00924 1247
600aa109 1248 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
d8ee0728 1249 tx = ops_run_biodrain(sh, tx);
91c00924
DW		 1250 overlap_clear++;
1251 }
1252
ac6b53b6
DW		 1253 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1254 if (level < 6)
1255 ops_run_reconstruct5(sh, percpu, tx);
1256 else
1257 ops_run_reconstruct6(sh, percpu, tx);
1258 }
91c00924 1259
ac6b53b6
DW		 1260 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1261 if (sh->check_state == check_state_run)
1262 ops_run_check_p(sh, percpu);
1263 else if (sh->check_state == check_state_run_q)
1264 ops_run_check_pq(sh, percpu, 0);
1265 else if (sh->check_state == check_state_run_pq)
1266 ops_run_check_pq(sh, percpu, 1);
1267 else
1268 BUG();
1269 }
91c00924 1270
91c00924
DW		 1271 if (overlap_clear)
1272 for (i = disks; i--; ) {
1273 struct r5dev *dev = &sh->dev[i];
1274 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1275 wake_up(&sh->raid_conf->wait_for_overlap);
1276 }
d6f38f31 1277 put_cpu();
91c00924
DW		 1278}
1279
417b8d4a
DW		 1280#ifdef CONFIG_MULTICORE_RAID456
1281static void async_run_ops(void *param, async_cookie_t cookie)
1282{
1283 struct stripe_head *sh = param;
1284 unsigned long ops_request = sh->ops.request;
1285
1286 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
1287 wake_up(&sh->ops.wait_for_ops);
1288
1289 __raid_run_ops(sh, ops_request);
1290 release_stripe(sh);
1291}
1292
1293static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1294{
1295 /* since handle_stripe can be called outside of raid5d context
1296 * we need to ensure sh->ops.request is de-staged before another
1297 * request arrives
1298 */
1299 wait_event(sh->ops.wait_for_ops,
1300 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
1301 sh->ops.request = ops_request;
1302
1303 atomic_inc(&sh->count);
1304 async_schedule(async_run_ops, sh);
1305}
1306#else
1307#define raid_run_ops __raid_run_ops
1308#endif
1309
3f294f4f 1310static int grow_one_stripe(raid5_conf_t *conf)
1da177e4
LT		 1311{
1312 struct stripe_head *sh;
6ce32846 1313 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
3f294f4f
N		 1314 if (!sh)
1315 return 0;
6ce32846 1316
3f294f4f 1317 sh->raid_conf = conf;
417b8d4a
DW		 1318 #ifdef CONFIG_MULTICORE_RAID456
1319 init_waitqueue_head(&sh->ops.wait_for_ops);
1320 #endif
3f294f4f 1321
e4e11e38
N		 1322 if (grow_buffers(sh)) {
1323 shrink_buffers(sh);
3f294f4f
N		 1324 kmem_cache_free(conf->slab_cache, sh);
1325 return 0;
1326 }
1327 /* we just created an active stripe so... */
1328 atomic_set(&sh->count, 1);
1329 atomic_inc(&conf->active_stripes);
1330 INIT_LIST_HEAD(&sh->lru);
1331 release_stripe(sh);
1332 return 1;
1333}
1334
1335static int grow_stripes(raid5_conf_t *conf, int num)
1336{
e18b890b 1337 struct kmem_cache *sc;
5e5e3e78 1338 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1da177e4 1339
f4be6b43
N		 1340 if (conf->mddev->gendisk)
1341 sprintf(conf->cache_name[0],
1342 "raid%d-%s", conf->level, mdname(conf->mddev));
1343 else
1344 sprintf(conf->cache_name[0],
1345 "raid%d-%p", conf->level, conf->mddev);
1346 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1347
ad01c9e3
N		 1348 conf->active_name = 0;
1349 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1da177e4 1350 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
20c2df83 1351 0, 0, NULL);
1da177e4
LT		 1352 if (!sc)
1353 return 1;
1354 conf->slab_cache = sc;
ad01c9e3 1355 conf->pool_size = devs;
16a53ecc 1356 while (num--)
3f294f4f 1357 if (!grow_one_stripe(conf))
1da177e4 1358 return 1;
1da177e4
LT		 1359 return 0;
1360}
29269553 1361
d6f38f31
DW		 1362/**
1363 * scribble_len - return the required size of the scribble region
1364 * @num - total number of disks in the array
1365 *
1366 * The size must be enough to contain:
1367 * 1/ a struct page pointer for each device in the array +2
1368 * 2/ room to convert each entry in (1) to its corresponding dma
1369 * (dma_map_page()) or page (page_address()) address.
1370 *
1371 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1372 * calculate over all devices (not just the data blocks), using zeros in place
1373 * of the P and Q blocks.
1374 */
1375static size_t scribble_len(int num)
1376{
1377 size_t len;
1378
1379 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1380
1381 return len;
1382}
1383
ad01c9e3
N		 1384static int resize_stripes(raid5_conf_t *conf, int newsize)
1385{
1386 /* Make all the stripes able to hold 'newsize' devices.
1387 * New slots in each stripe get 'page' set to a new page.
1388 *
1389 * This happens in stages:
1390 * 1/ create a new kmem_cache and allocate the required number of
1391 * stripe_heads.
1392 * 2/ gather all the old stripe_heads and tranfer the pages across
1393 * to the new stripe_heads. This will have the side effect of
1394 * freezing the array as once all stripe_heads have been collected,
1395 * no IO will be possible. Old stripe heads are freed once their
1396 * pages have been transferred over, and the old kmem_cache is
1397 * freed when all stripes are done.
1398 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1399 * we simple return a failre status - no need to clean anything up.
1400 * 4/ allocate new pages for the new slots in the new stripe_heads.
1401 * If this fails, we don't bother trying the shrink the
1402 * stripe_heads down again, we just leave them as they are.
1403 * As each stripe_head is processed the new one is released into
1404 * active service.
1405 *
1406 * Once step2 is started, we cannot afford to wait for a write,
1407 * so we use GFP_NOIO allocations.
1408 */
1409 struct stripe_head *osh, *nsh;
1410 LIST_HEAD(newstripes);
1411 struct disk_info *ndisks;
d6f38f31 1412 unsigned long cpu;
b5470dc5 1413 int err;
e18b890b 1414 struct kmem_cache *sc;
ad01c9e3
N		 1415 int i;
1416
1417 if (newsize <= conf->pool_size)
1418 return 0; /* never bother to shrink */
1419
b5470dc5
DW		 1420 err = md_allow_write(conf->mddev);
1421 if (err)
1422 return err;
2a2275d6 1423
ad01c9e3
N		 1424 /* Step 1 */
1425 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1426 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
20c2df83 1427 0, 0, NULL);
ad01c9e3
N		 1428 if (!sc)
1429 return -ENOMEM;
1430
1431 for (i = conf->max_nr_stripes; i; i--) {
6ce32846 1432 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
ad01c9e3
N		 1433 if (!nsh)
1434 break;
1435
ad01c9e3 1436 nsh->raid_conf = conf;
417b8d4a
DW		 1437 #ifdef CONFIG_MULTICORE_RAID456
1438 init_waitqueue_head(&nsh->ops.wait_for_ops);
1439 #endif
ad01c9e3
N		 1440
1441 list_add(&nsh->lru, &newstripes);
1442 }
1443 if (i) {
1444 /* didn't get enough, give up */
1445 while (!list_empty(&newstripes)) {
1446 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1447 list_del(&nsh->lru);
1448 kmem_cache_free(sc, nsh);
1449 }
1450 kmem_cache_destroy(sc);
1451 return -ENOMEM;
1452 }
1453 /* Step 2 - Must use GFP_NOIO now.
1454 * OK, we have enough stripes, start collecting inactive
1455 * stripes and copying them over
1456 */
1457 list_for_each_entry(nsh, &newstripes, lru) {
1458 spin_lock_irq(&conf->device_lock);
1459 wait_event_lock_irq(conf->wait_for_stripe,
1460 !list_empty(&conf->inactive_list),
1461 conf->device_lock,
482c0834 1462 );
ad01c9e3
N		 1463 osh = get_free_stripe(conf);
1464 spin_unlock_irq(&conf->device_lock);
1465 atomic_set(&nsh->count, 1);
1466 for(i=0; i<conf->pool_size; i++)
1467 nsh->dev[i].page = osh->dev[i].page;
1468 for( ; i<newsize; i++)
1469 nsh->dev[i].page = NULL;
1470 kmem_cache_free(conf->slab_cache, osh);
1471 }
1472 kmem_cache_destroy(conf->slab_cache);
1473
1474 /* Step 3.
1475 * At this point, we are holding all the stripes so the array
1476 * is completely stalled, so now is a good time to resize
d6f38f31 1477 * conf->disks and the scribble region
ad01c9e3
N		 1478 */
1479 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1480 if (ndisks) {
1481 for (i=0; i<conf->raid_disks; i++)
1482 ndisks[i] = conf->disks[i];
1483 kfree(conf->disks);
1484 conf->disks = ndisks;
1485 } else
1486 err = -ENOMEM;
1487
d6f38f31
DW		 1488 get_online_cpus();
1489 conf->scribble_len = scribble_len(newsize);
1490 for_each_present_cpu(cpu) {
1491 struct raid5_percpu *percpu;
1492 void *scribble;
1493
1494 percpu = per_cpu_ptr(conf->percpu, cpu);
1495 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1496
1497 if (scribble) {
1498 kfree(percpu->scribble);
1499 percpu->scribble = scribble;
1500 } else {
1501 err = -ENOMEM;
1502 break;
1503 }
1504 }
1505 put_online_cpus();
1506
ad01c9e3
N		 1507 /* Step 4, return new stripes to service */
1508 while(!list_empty(&newstripes)) {
1509 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1510 list_del_init(&nsh->lru);
d6f38f31 1511
ad01c9e3
N		 1512 for (i=conf->raid_disks; i < newsize; i++)
1513 if (nsh->dev[i].page == NULL) {
1514 struct page *p = alloc_page(GFP_NOIO);
1515 nsh->dev[i].page = p;
1516 if (!p)
1517 err = -ENOMEM;
1518 }
1519 release_stripe(nsh);
1520 }
1521 /* critical section pass, GFP_NOIO no longer needed */
1522
1523 conf->slab_cache = sc;
1524 conf->active_name = 1-conf->active_name;
1525 conf->pool_size = newsize;
1526 return err;
1527}
1da177e4 1528
3f294f4f 1529static int drop_one_stripe(raid5_conf_t *conf)
1da177e4
LT		 1530{
1531 struct stripe_head *sh;
1532
3f294f4f
N		 1533 spin_lock_irq(&conf->device_lock);
1534 sh = get_free_stripe(conf);
1535 spin_unlock_irq(&conf->device_lock);
1536 if (!sh)
1537 return 0;
78bafebd 1538 BUG_ON(atomic_read(&sh->count));
e4e11e38 1539 shrink_buffers(sh);
3f294f4f
N		 1540 kmem_cache_free(conf->slab_cache, sh);
1541 atomic_dec(&conf->active_stripes);
1542 return 1;
1543}
1544
1545static void shrink_stripes(raid5_conf_t *conf)
1546{
1547 while (drop_one_stripe(conf))
1548 ;
1549
29fc7e3e
N		 1550 if (conf->slab_cache)
1551 kmem_cache_destroy(conf->slab_cache);
1da177e4
LT		 1552 conf->slab_cache = NULL;
1553}
1554
6712ecf8 1555static void raid5_end_read_request(struct bio * bi, int error)
1da177e4 1556{
99c0fb5f 1557 struct stripe_head *sh = bi->bi_private;
1da177e4 1558 raid5_conf_t *conf = sh->raid_conf;
7ecaa1e6 1559 int disks = sh->disks, i;
1da177e4 1560 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
d6950432
N		 1561 char b[BDEVNAME_SIZE];
1562 mdk_rdev_t *rdev;
1da177e4 1563
1da177e4
LT		 1564
1565 for (i=0 ; i<disks; i++)
1566 if (bi == &sh->dev[i].req)
1567 break;
1568
45b4233c
DW		 1569 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1570 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1da177e4
LT		 1571 uptodate);
1572 if (i == disks) {
1573 BUG();
6712ecf8 1574 return;
1da177e4
LT		 1575 }
1576
1577 if (uptodate) {
1da177e4 1578 set_bit(R5_UPTODATE, &sh->dev[i].flags);
4e5314b5 1579 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
d6950432 1580 rdev = conf->disks[i].rdev;
8bda470e
CD		 1581 printk_ratelimited(
1582 KERN_INFO
1583 "md/raid:%s: read error corrected"
1584 " (%lu sectors at %llu on %s)\n",
1585 mdname(conf->mddev), STRIPE_SECTORS,
1586 (unsigned long long)(sh->sector
1587 + rdev->data_offset),
1588 bdevname(rdev->bdev, b));
ddd5115f 1589 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
4e5314b5
N		 1590 clear_bit(R5_ReadError, &sh->dev[i].flags);
1591 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1592 }
ba22dcbf
N		 1593 if (atomic_read(&conf->disks[i].rdev->read_errors))
1594 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1da177e4 1595 } else {
d6950432 1596 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
ba22dcbf 1597 int retry = 0;
d6950432
N		 1598 rdev = conf->disks[i].rdev;
1599
1da177e4 1600 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
d6950432 1601 atomic_inc(&rdev->read_errors);
7b0bb536 1602 if (conf->mddev->degraded >= conf->max_degraded)
8bda470e
CD		 1603 printk_ratelimited(
1604 KERN_WARNING
1605 "md/raid:%s: read error not correctable "
1606 "(sector %llu on %s).\n",
1607 mdname(conf->mddev),
1608 (unsigned long long)(sh->sector
1609 + rdev->data_offset),
1610 bdn);
ba22dcbf 1611 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
4e5314b5 1612 /* Oh, no!!! */
8bda470e
CD		 1613 printk_ratelimited(
1614 KERN_WARNING
1615 "md/raid:%s: read error NOT corrected!! "
1616 "(sector %llu on %s).\n",
1617 mdname(conf->mddev),
1618 (unsigned long long)(sh->sector
1619 + rdev->data_offset),
1620 bdn);
d6950432 1621 else if (atomic_read(&rdev->read_errors)
ba22dcbf 1622 > conf->max_nr_stripes)
14f8d26b 1623 printk(KERN_WARNING
0c55e022 1624 "md/raid:%s: Too many read errors, failing device %s.\n",
d6950432 1625 mdname(conf->mddev), bdn);
ba22dcbf
N		 1626 else
1627 retry = 1;
1628 if (retry)
1629 set_bit(R5_ReadError, &sh->dev[i].flags);
1630 else {
4e5314b5
N		 1631 clear_bit(R5_ReadError, &sh->dev[i].flags);
1632 clear_bit(R5_ReWrite, &sh->dev[i].flags);
d6950432 1633 md_error(conf->mddev, rdev);
ba22dcbf 1634 }
1da177e4
LT		 1635 }
1636 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1da177e4
LT		 1637 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1638 set_bit(STRIPE_HANDLE, &sh->state);
1639 release_stripe(sh);
1da177e4
LT		 1640}
1641
d710e138 1642static void raid5_end_write_request(struct bio *bi, int error)
1da177e4 1643{
99c0fb5f 1644 struct stripe_head *sh = bi->bi_private;
1da177e4 1645 raid5_conf_t *conf = sh->raid_conf;
7ecaa1e6 1646 int disks = sh->disks, i;
1da177e4
LT		 1647 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1648
1da177e4
LT		 1649 for (i=0 ; i<disks; i++)
1650 if (bi == &sh->dev[i].req)
1651 break;
1652
45b4233c 1653 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1da177e4
LT		 1654 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1655 uptodate);
1656 if (i == disks) {
1657 BUG();
6712ecf8 1658 return;
1da177e4
LT		 1659 }
1660
1da177e4
LT		 1661 if (!uptodate)
1662 md_error(conf->mddev, conf->disks[i].rdev);
1663
1664 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1665
1666 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1667 set_bit(STRIPE_HANDLE, &sh->state);
c04be0aa 1668 release_stripe(sh);
1da177e4
LT		 1669}
1670
1671
784052ec 1672static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1da177e4 1673
784052ec 1674static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1da177e4
LT		 1675{
1676 struct r5dev *dev = &sh->dev[i];
1677
1678 bio_init(&dev->req);
1679 dev->req.bi_io_vec = &dev->vec;
1680 dev->req.bi_vcnt++;
1681 dev->req.bi_max_vecs++;
1682 dev->vec.bv_page = dev->page;
1683 dev->vec.bv_len = STRIPE_SIZE;
1684 dev->vec.bv_offset = 0;
1685
1686 dev->req.bi_sector = sh->sector;
1687 dev->req.bi_private = sh;
1688
1689 dev->flags = 0;
784052ec 1690 dev->sector = compute_blocknr(sh, i, previous);
1da177e4
LT		 1691}
1692
1693static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1694{
1695 char b[BDEVNAME_SIZE];
7b92813c 1696 raid5_conf_t *conf = mddev->private;
0c55e022 1697 pr_debug("raid456: error called\n");
1da177e4 1698
6f8d0c77
N		 1699 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1700 unsigned long flags;
1701 spin_lock_irqsave(&conf->device_lock, flags);
1702 mddev->degraded++;
1703 spin_unlock_irqrestore(&conf->device_lock, flags);
1704 /*
1705 * if recovery was running, make sure it aborts.
1706 */
1707 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1da177e4 1708 }
6f8d0c77
N		 1709 set_bit(Faulty, &rdev->flags);
1710 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1711 printk(KERN_ALERT
1712 "md/raid:%s: Disk failure on %s, disabling device.\n"
1713 "md/raid:%s: Operation continuing on %d devices.\n",
1714 mdname(mddev),
1715 bdevname(rdev->bdev, b),
1716 mdname(mddev),
1717 conf->raid_disks - mddev->degraded);
16a53ecc 1718}
1da177e4
LT		 1719
1720/*
1721 * Input: a 'big' sector number,
1722 * Output: index of the data and parity disk, and the sector # in them.
1723 */
112bf897 1724static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
911d4ee8
N		 1725 int previous, int *dd_idx,
1726 struct stripe_head *sh)
1da177e4 1727{
6e3b96ed 1728 sector_t stripe, stripe2;
35f2a591 1729 sector_t chunk_number;
1da177e4 1730 unsigned int chunk_offset;
911d4ee8 1731 int pd_idx, qd_idx;
67cc2b81 1732 int ddf_layout = 0;
1da177e4 1733 sector_t new_sector;
e183eaed
N		 1734 int algorithm = previous ? conf->prev_algo
1735 : conf->algorithm;
09c9e5fa
AN		 1736 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1737 : conf->chunk_sectors;
112bf897
N		 1738 int raid_disks = previous ? conf->previous_raid_disks
1739 : conf->raid_disks;
1740 int data_disks = raid_disks - conf->max_degraded;
1da177e4
LT		 1741
1742 /* First compute the information on this sector */
1743
1744 /*
1745 * Compute the chunk number and the sector offset inside the chunk
1746 */
1747 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1748 chunk_number = r_sector;
1da177e4
LT		 1749
1750 /*
1751 * Compute the stripe number
1752 */
35f2a591
N		 1753 stripe = chunk_number;
1754 *dd_idx = sector_div(stripe, data_disks);
6e3b96ed 1755 stripe2 = stripe;
1da177e4
LT		 1756 /*
1757 * Select the parity disk based on the user selected algorithm.
1758 */
84789554 1759 pd_idx = qd_idx = -1;
16a53ecc
N		 1760 switch(conf->level) {
1761 case 4:
911d4ee8 1762 pd_idx = data_disks;
16a53ecc
N		 1763 break;
1764 case 5:
e183eaed 1765 switch (algorithm) {
1da177e4 1766 case ALGORITHM_LEFT_ASYMMETRIC:
6e3b96ed 1767 pd_idx = data_disks - sector_div(stripe2, raid_disks);
911d4ee8 1768 if (*dd_idx >= pd_idx)
1da177e4
LT		 1769 (*dd_idx)++;
1770 break;
1771 case ALGORITHM_RIGHT_ASYMMETRIC:
6e3b96ed 1772 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8 1773 if (*dd_idx >= pd_idx)
1da177e4
LT		 1774 (*dd_idx)++;
1775 break;
1776 case ALGORITHM_LEFT_SYMMETRIC:
6e3b96ed 1777 pd_idx = data_disks - sector_div(stripe2, raid_disks);
911d4ee8 1778 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1da177e4
LT		 1779 break;
1780 case ALGORITHM_RIGHT_SYMMETRIC:
6e3b96ed 1781 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8 1782 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1da177e4 1783 break;
99c0fb5f
N		 1784 case ALGORITHM_PARITY_0:
1785 pd_idx = 0;
1786 (*dd_idx)++;
1787 break;
1788 case ALGORITHM_PARITY_N:
1789 pd_idx = data_disks;
1790 break;
1da177e4 1791 default:
99c0fb5f 1792 BUG();
16a53ecc
N		 1793 }
1794 break;
1795 case 6:
1796
e183eaed 1797 switch (algorithm) {
16a53ecc 1798 case ALGORITHM_LEFT_ASYMMETRIC:
6e3b96ed 1799 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
911d4ee8
N		 1800 qd_idx = pd_idx + 1;
1801 if (pd_idx == raid_disks-1) {
99c0fb5f 1802 (*dd_idx)++; /* Q D D D P */
911d4ee8
N		 1803 qd_idx = 0;
1804 } else if (*dd_idx >= pd_idx)
16a53ecc
N		 1805 (*dd_idx) += 2; /* D D P Q D */
1806 break;
1807 case ALGORITHM_RIGHT_ASYMMETRIC:
6e3b96ed 1808 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8
N		 1809 qd_idx = pd_idx + 1;
1810 if (pd_idx == raid_disks-1) {
99c0fb5f 1811 (*dd_idx)++; /* Q D D D P */
911d4ee8
N		 1812 qd_idx = 0;
1813 } else if (*dd_idx >= pd_idx)
16a53ecc
N		 1814 (*dd_idx) += 2; /* D D P Q D */
1815 break;
1816 case ALGORITHM_LEFT_SYMMETRIC:
6e3b96ed 1817 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
911d4ee8
N		 1818 qd_idx = (pd_idx + 1) % raid_disks;
1819 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
16a53ecc
N		 1820 break;
1821 case ALGORITHM_RIGHT_SYMMETRIC:
6e3b96ed 1822 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8
N		 1823 qd_idx = (pd_idx + 1) % raid_disks;
1824 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
16a53ecc 1825 break;
99c0fb5f
N		 1826
1827 case ALGORITHM_PARITY_0:
1828 pd_idx = 0;
1829 qd_idx = 1;
1830 (*dd_idx) += 2;
1831 break;
1832 case ALGORITHM_PARITY_N:
1833 pd_idx = data_disks;
1834 qd_idx = data_disks + 1;
1835 break;
1836
1837 case ALGORITHM_ROTATING_ZERO_RESTART:
1838 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1839 * of blocks for computing Q is different.
1840 */
6e3b96ed 1841 pd_idx = sector_div(stripe2, raid_disks);
99c0fb5f
N		 1842 qd_idx = pd_idx + 1;
1843 if (pd_idx == raid_disks-1) {
1844 (*dd_idx)++; /* Q D D D P */
1845 qd_idx = 0;
1846 } else if (*dd_idx >= pd_idx)
1847 (*dd_idx) += 2; /* D D P Q D */
67cc2b81 1848 ddf_layout = 1;
99c0fb5f
N		 1849 break;
1850
1851 case ALGORITHM_ROTATING_N_RESTART:
1852 /* Same a left_asymmetric, by first stripe is
1853 * D D D P Q rather than
1854 * Q D D D P
1855 */
6e3b96ed
N		 1856 stripe2 += 1;
1857 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
99c0fb5f
N		 1858 qd_idx = pd_idx + 1;
1859 if (pd_idx == raid_disks-1) {
1860 (*dd_idx)++; /* Q D D D P */
1861 qd_idx = 0;
1862 } else if (*dd_idx >= pd_idx)
1863 (*dd_idx) += 2; /* D D P Q D */
67cc2b81 1864 ddf_layout = 1;
99c0fb5f
N		 1865 break;
1866
1867 case ALGORITHM_ROTATING_N_CONTINUE:
1868 /* Same as left_symmetric but Q is before P */
6e3b96ed 1869 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
99c0fb5f
N		 1870 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1871 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
67cc2b81 1872 ddf_layout = 1;
99c0fb5f
N		 1873 break;
1874
1875 case ALGORITHM_LEFT_ASYMMETRIC_6:
1876 /* RAID5 left_asymmetric, with Q on last device */
6e3b96ed 1877 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 1878 if (*dd_idx >= pd_idx)
1879 (*dd_idx)++;
1880 qd_idx = raid_disks - 1;
1881 break;
1882
1883 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6e3b96ed 1884 pd_idx = sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 1885 if (*dd_idx >= pd_idx)
1886 (*dd_idx)++;
1887 qd_idx = raid_disks - 1;
1888 break;
1889
1890 case ALGORITHM_LEFT_SYMMETRIC_6:
6e3b96ed 1891 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 1892 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1893 qd_idx = raid_disks - 1;
1894 break;
1895
1896 case ALGORITHM_RIGHT_SYMMETRIC_6:
6e3b96ed 1897 pd_idx = sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 1898 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1899 qd_idx = raid_disks - 1;
1900 break;
1901
1902 case ALGORITHM_PARITY_0_6:
1903 pd_idx = 0;
1904 (*dd_idx)++;
1905 qd_idx = raid_disks - 1;
1906 break;
1907
16a53ecc 1908 default:
99c0fb5f 1909 BUG();
16a53ecc
N		 1910 }
1911 break;
1da177e4
LT		 1912 }
1913
911d4ee8
N		 1914 if (sh) {
1915 sh->pd_idx = pd_idx;
1916 sh->qd_idx = qd_idx;
67cc2b81 1917 sh->ddf_layout = ddf_layout;
911d4ee8 1918 }
1da177e4
LT		 1919 /*
1920 * Finally, compute the new sector number
1921 */
1922 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1923 return new_sector;
1924}
1925
1926
784052ec 1927static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
1da177e4
LT		 1928{
1929 raid5_conf_t *conf = sh->raid_conf;
b875e531
N		 1930 int raid_disks = sh->disks;
1931 int data_disks = raid_disks - conf->max_degraded;
1da177e4 1932 sector_t new_sector = sh->sector, check;
09c9e5fa
AN		 1933 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1934 : conf->chunk_sectors;
e183eaed
N		 1935 int algorithm = previous ? conf->prev_algo
1936 : conf->algorithm;
1da177e4
LT		 1937 sector_t stripe;
1938 int chunk_offset;
35f2a591
N		 1939 sector_t chunk_number;
1940 int dummy1, dd_idx = i;
1da177e4 1941 sector_t r_sector;
911d4ee8 1942 struct stripe_head sh2;
1da177e4 1943
16a53ecc 1944
1da177e4
LT		 1945 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1946 stripe = new_sector;
1da177e4 1947
16a53ecc
N		 1948 if (i == sh->pd_idx)
1949 return 0;
1950 switch(conf->level) {
1951 case 4: break;
1952 case 5:
e183eaed 1953 switch (algorithm) {
1da177e4
LT		 1954 case ALGORITHM_LEFT_ASYMMETRIC:
1955 case ALGORITHM_RIGHT_ASYMMETRIC:
1956 if (i > sh->pd_idx)
1957 i--;
1958 break;
1959 case ALGORITHM_LEFT_SYMMETRIC:
1960 case ALGORITHM_RIGHT_SYMMETRIC:
1961 if (i < sh->pd_idx)
1962 i += raid_disks;
1963 i -= (sh->pd_idx + 1);
1964 break;
99c0fb5f
N		 1965 case ALGORITHM_PARITY_0:
1966 i -= 1;
1967 break;
1968 case ALGORITHM_PARITY_N:
1969 break;
1da177e4 1970 default:
99c0fb5f 1971 BUG();
16a53ecc
N		 1972 }
1973 break;
1974 case 6:
d0dabf7e 1975 if (i == sh->qd_idx)
16a53ecc 1976 return 0; /* It is the Q disk */
e183eaed 1977 switch (algorithm) {
16a53ecc
N		 1978 case ALGORITHM_LEFT_ASYMMETRIC:
1979 case ALGORITHM_RIGHT_ASYMMETRIC:
99c0fb5f
N		 1980 case ALGORITHM_ROTATING_ZERO_RESTART:
1981 case ALGORITHM_ROTATING_N_RESTART:
1982 if (sh->pd_idx == raid_disks-1)
1983 i--; /* Q D D D P */
16a53ecc
N		 1984 else if (i > sh->pd_idx)
1985 i -= 2; /* D D P Q D */
1986 break;
1987 case ALGORITHM_LEFT_SYMMETRIC:
1988 case ALGORITHM_RIGHT_SYMMETRIC:
1989 if (sh->pd_idx == raid_disks-1)
1990 i--; /* Q D D D P */
1991 else {
1992 /* D D P Q D */
1993 if (i < sh->pd_idx)
1994 i += raid_disks;
1995 i -= (sh->pd_idx + 2);
1996 }
1997 break;
99c0fb5f
N		 1998 case ALGORITHM_PARITY_0:
1999 i -= 2;
2000 break;
2001 case ALGORITHM_PARITY_N:
2002 break;
2003 case ALGORITHM_ROTATING_N_CONTINUE:
e4424fee 2004 /* Like left_symmetric, but P is before Q */
99c0fb5f
N		 2005 if (sh->pd_idx == 0)
2006 i--; /* P D D D Q */
e4424fee
N		 2007 else {
2008 /* D D Q P D */
2009 if (i < sh->pd_idx)
2010 i += raid_disks;
2011 i -= (sh->pd_idx + 1);
2012 }
99c0fb5f
N		 2013 break;
2014 case ALGORITHM_LEFT_ASYMMETRIC_6:
2015 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2016 if (i > sh->pd_idx)
2017 i--;
2018 break;
2019 case ALGORITHM_LEFT_SYMMETRIC_6:
2020 case ALGORITHM_RIGHT_SYMMETRIC_6:
2021 if (i < sh->pd_idx)
2022 i += data_disks + 1;
2023 i -= (sh->pd_idx + 1);
2024 break;
2025 case ALGORITHM_PARITY_0_6:
2026 i -= 1;
2027 break;
16a53ecc 2028 default:
99c0fb5f 2029 BUG();
16a53ecc
N		 2030 }
2031 break;
1da177e4
LT		 2032 }
2033
2034 chunk_number = stripe * data_disks + i;
35f2a591 2035 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
1da177e4 2036
112bf897 2037 check = raid5_compute_sector(conf, r_sector,
784052ec 2038 previous, &dummy1, &sh2);
911d4ee8
N		 2039 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2040 || sh2.qd_idx != sh->qd_idx) {
0c55e022
N		 2041 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2042 mdname(conf->mddev));
1da177e4
LT		 2043 return 0;
2044 }
2045 return r_sector;
2046}
2047
2048
600aa109 2049static void
c0f7bddb 2050schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
600aa109 2051 int rcw, int expand)
e33129d8
DW		 2052{
2053 int i, pd_idx = sh->pd_idx, disks = sh->disks;
c0f7bddb
YT		 2054 raid5_conf_t *conf = sh->raid_conf;
2055 int level = conf->level;
e33129d8
DW		 2056
2057 if (rcw) {
2058 /* if we are not expanding this is a proper write request, and
2059 * there will be bios with new data to be drained into the
2060 * stripe cache
2061 */
2062 if (!expand) {
600aa109
DW		 2063 sh->reconstruct_state = reconstruct_state_drain_run;
2064 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2065 } else
2066 sh->reconstruct_state = reconstruct_state_run;
16a53ecc 2067
ac6b53b6 2068 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
e33129d8
DW		 2069
2070 for (i = disks; i--; ) {
2071 struct r5dev *dev = &sh->dev[i];
2072
2073 if (dev->towrite) {
2074 set_bit(R5_LOCKED, &dev->flags);
d8ee0728 2075 set_bit(R5_Wantdrain, &dev->flags);
e33129d8
DW		 2076 if (!expand)
2077 clear_bit(R5_UPTODATE, &dev->flags);
600aa109 2078 s->locked++;
e33129d8
DW		 2079 }
2080 }
c0f7bddb 2081 if (s->locked + conf->max_degraded == disks)
8b3e6cdc 2082 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
c0f7bddb 2083 atomic_inc(&conf->pending_full_writes);
e33129d8 2084 } else {
c0f7bddb 2085 BUG_ON(level == 6);
e33129d8
DW		 2086 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2087 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2088
d8ee0728 2089 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
600aa109
DW		 2090 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2091 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
ac6b53b6 2092 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
e33129d8
DW		 2093
2094 for (i = disks; i--; ) {
2095 struct r5dev *dev = &sh->dev[i];
2096 if (i == pd_idx)
2097 continue;
2098
e33129d8
DW		 2099 if (dev->towrite &&
2100 (test_bit(R5_UPTODATE, &dev->flags) ||
d8ee0728
DW		 2101 test_bit(R5_Wantcompute, &dev->flags))) {
2102 set_bit(R5_Wantdrain, &dev->flags);
e33129d8
DW		 2103 set_bit(R5_LOCKED, &dev->flags);
2104 clear_bit(R5_UPTODATE, &dev->flags);
600aa109 2105 s->locked++;
e33129d8
DW		 2106 }
2107 }
2108 }
2109
c0f7bddb 2110 /* keep the parity disk(s) locked while asynchronous operations
e33129d8
DW		 2111 * are in flight
2112 */
2113 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2114 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
600aa109 2115 s->locked++;
e33129d8 2116
c0f7bddb
YT		 2117 if (level == 6) {
2118 int qd_idx = sh->qd_idx;
2119 struct r5dev *dev = &sh->dev[qd_idx];
2120
2121 set_bit(R5_LOCKED, &dev->flags);
2122 clear_bit(R5_UPTODATE, &dev->flags);
2123 s->locked++;
2124 }
2125
600aa109 2126 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
e46b272b 2127 __func__, (unsigned long long)sh->sector,
600aa109 2128 s->locked, s->ops_request);
e33129d8 2129}
16a53ecc 2130
1da177e4
LT		 2131/*
2132 * Each stripe/dev can have one or more bion attached.
16a53ecc 2133 * toread/towrite point to the first in a chain.
1da177e4
LT		 2134 * The bi_next chain must be in order.
2135 */
2136static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2137{
2138 struct bio **bip;
2139 raid5_conf_t *conf = sh->raid_conf;
72626685 2140 int firstwrite=0;
1da177e4 2141
cbe47ec5 2142 pr_debug("adding bi b#%llu to stripe s#%llu\n",
1da177e4
LT		 2143 (unsigned long long)bi->bi_sector,
2144 (unsigned long long)sh->sector);
2145
2146
1da177e4 2147 spin_lock_irq(&conf->device_lock);
72626685 2148 if (forwrite) {
1da177e4 2149 bip = &sh->dev[dd_idx].towrite;
72626685
N		 2150 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
2151 firstwrite = 1;
2152 } else
1da177e4
LT		 2153 bip = &sh->dev[dd_idx].toread;
2154 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2155 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
2156 goto overlap;
2157 bip = & (*bip)->bi_next;
2158 }
2159 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
2160 goto overlap;
2161
78bafebd 2162 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
1da177e4
LT		 2163 if (*bip)
2164 bi->bi_next = *bip;
2165 *bip = bi;
960e739d 2166 bi->bi_phys_segments++;
72626685 2167
1da177e4
LT		 2168 if (forwrite) {
2169 /* check if page is covered */
2170 sector_t sector = sh->dev[dd_idx].sector;
2171 for (bi=sh->dev[dd_idx].towrite;
2172 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2173 bi && bi->bi_sector <= sector;
2174 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2175 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
2176 sector = bi->bi_sector + (bi->bi_size>>9);
2177 }
2178 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2179 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2180 }
cbe47ec5 2181 spin_unlock_irq(&conf->device_lock);
cbe47ec5
N		 2182
2183 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2184 (unsigned long long)(*bip)->bi_sector,
2185 (unsigned long long)sh->sector, dd_idx);
2186
2187 if (conf->mddev->bitmap && firstwrite) {
2188 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2189 STRIPE_SECTORS, 0);
2190 sh->bm_seq = conf->seq_flush+1;
2191 set_bit(STRIPE_BIT_DELAY, &sh->state);
2192 }
1da177e4
LT		 2193 return 1;
2194
2195 overlap:
2196 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2197 spin_unlock_irq(&conf->device_lock);
1da177e4
LT		 2198 return 0;
2199}
2200
29269553
N		 2201static void end_reshape(raid5_conf_t *conf);
2202
911d4ee8
N		 2203static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
2204 struct stripe_head *sh)
ccfcc3c1 2205{
784052ec 2206 int sectors_per_chunk =
09c9e5fa 2207 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
911d4ee8 2208 int dd_idx;
2d2063ce 2209 int chunk_offset = sector_div(stripe, sectors_per_chunk);
112bf897 2210 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2d2063ce 2211
112bf897
N		 2212 raid5_compute_sector(conf,
2213 stripe * (disks - conf->max_degraded)
b875e531 2214 *sectors_per_chunk + chunk_offset,
112bf897 2215 previous,
911d4ee8 2216 &dd_idx, sh);
ccfcc3c1
N		 2217}
2218
a4456856 2219static void
1fe797e6 2220handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
a4456856
DW		 2221 struct stripe_head_state *s, int disks,
2222 struct bio **return_bi)
2223{
2224 int i;
2225 for (i = disks; i--; ) {
2226 struct bio *bi;
2227 int bitmap_end = 0;
2228
2229 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2230 mdk_rdev_t *rdev;
2231 rcu_read_lock();
2232 rdev = rcu_dereference(conf->disks[i].rdev);
2233 if (rdev && test_bit(In_sync, &rdev->flags))
2234 /* multiple read failures in one stripe */
2235 md_error(conf->mddev, rdev);
2236 rcu_read_unlock();
2237 }
2238 spin_lock_irq(&conf->device_lock);
2239 /* fail all writes first */
2240 bi = sh->dev[i].towrite;
2241 sh->dev[i].towrite = NULL;
2242 if (bi) {
2243 s->to_write--;
2244 bitmap_end = 1;
2245 }
2246
2247 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2248 wake_up(&conf->wait_for_overlap);
2249
2250 while (bi && bi->bi_sector <
2251 sh->dev[i].sector + STRIPE_SECTORS) {
2252 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2253 clear_bit(BIO_UPTODATE, &bi->bi_flags);
960e739d 2254 if (!raid5_dec_bi_phys_segments(bi)) {
a4456856
DW		 2255 md_write_end(conf->mddev);
2256 bi->bi_next = *return_bi;
2257 *return_bi = bi;
2258 }
2259 bi = nextbi;
2260 }
2261 /* and fail all 'written' */
2262 bi = sh->dev[i].written;
2263 sh->dev[i].written = NULL;
2264 if (bi) bitmap_end = 1;
2265 while (bi && bi->bi_sector <
2266 sh->dev[i].sector + STRIPE_SECTORS) {
2267 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2268 clear_bit(BIO_UPTODATE, &bi->bi_flags);
960e739d 2269 if (!raid5_dec_bi_phys_segments(bi)) {
a4456856
DW		 2270 md_write_end(conf->mddev);
2271 bi->bi_next = *return_bi;
2272 *return_bi = bi;
2273 }
2274 bi = bi2;
2275 }
2276
b5e98d65
DW		 2277 /* fail any reads if this device is non-operational and
2278 * the data has not reached the cache yet.
2279 */
2280 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2281 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2282 test_bit(R5_ReadError, &sh->dev[i].flags))) {
a4456856
DW		 2283 bi = sh->dev[i].toread;
2284 sh->dev[i].toread = NULL;
2285 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2286 wake_up(&conf->wait_for_overlap);
2287 if (bi) s->to_read--;
2288 while (bi && bi->bi_sector <
2289 sh->dev[i].sector + STRIPE_SECTORS) {
2290 struct bio *nextbi =
2291 r5_next_bio(bi, sh->dev[i].sector);
2292 clear_bit(BIO_UPTODATE, &bi->bi_flags);
960e739d 2293 if (!raid5_dec_bi_phys_segments(bi)) {
a4456856
DW		 2294 bi->bi_next = *return_bi;
2295 *return_bi = bi;
2296 }
2297 bi = nextbi;
2298 }
2299 }
2300 spin_unlock_irq(&conf->device_lock);
2301 if (bitmap_end)
2302 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2303 STRIPE_SECTORS, 0, 0);
2304 }
2305
8b3e6cdc
DW		 2306 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2307 if (atomic_dec_and_test(&conf->pending_full_writes))
2308 md_wakeup_thread(conf->mddev->thread);
a4456856
DW		 2309}
2310
93b3dbce 2311/* fetch_block - checks the given member device to see if its data needs
1fe797e6
DW		 2312 * to be read or computed to satisfy a request.
2313 *
2314 * Returns 1 when no more member devices need to be checked, otherwise returns
93b3dbce 2315 * 0 to tell the loop in handle_stripe_fill to continue
f38e1219 2316 */
93b3dbce
N		 2317static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
2318 int disk_idx, int disks)
a4456856 2319{
5599becc 2320 struct r5dev *dev = &sh->dev[disk_idx];
f2b3b44d
N		 2321 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
2322 &sh->dev[s->failed_num[1]] };
5599becc 2323
93b3dbce 2324 /* is the data in this block needed, and can we get it? */
5599becc
YT		 2325 if (!test_bit(R5_LOCKED, &dev->flags) &&
2326 !test_bit(R5_UPTODATE, &dev->flags) &&
2327 (dev->toread ||
2328 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2329 s->syncing || s->expanding ||
5d35e09c
N		 2330 (s->failed >= 1 && fdev[0]->toread) ||
2331 (s->failed >= 2 && fdev[1]->toread) ||
93b3dbce
N		 2332 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
2333 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
2334 (sh->raid_conf->level == 6 && s->failed && s->to_write))) {
5599becc
YT		 2335 /* we would like to get this block, possibly by computing it,
2336 * otherwise read it if the backing disk is insync
2337 */
2338 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2339 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2340 if ((s->uptodate == disks - 1) &&
f2b3b44d
N		 2341 (s->failed && (disk_idx == s->failed_num[0] ||
2342 disk_idx == s->failed_num[1]))) {
5599becc
YT		 2343 /* have disk failed, and we're requested to fetch it;
2344 * do compute it
a4456856 2345 */
5599becc
YT		 2346 pr_debug("Computing stripe %llu block %d\n",
2347 (unsigned long long)sh->sector, disk_idx);
2348 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2349 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2350 set_bit(R5_Wantcompute, &dev->flags);
2351 sh->ops.target = disk_idx;
2352 sh->ops.target2 = -1; /* no 2nd target */
2353 s->req_compute = 1;
93b3dbce
N		 2354 /* Careful: from this point on 'uptodate' is in the eye
2355 * of raid_run_ops which services 'compute' operations
2356 * before writes. R5_Wantcompute flags a block that will
2357 * be R5_UPTODATE by the time it is needed for a
2358 * subsequent operation.
2359 */
5599becc
YT		 2360 s->uptodate++;
2361 return 1;
2362 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2363 /* Computing 2-failure is *very* expensive; only
2364 * do it if failed >= 2
2365 */
2366 int other;
2367 for (other = disks; other--; ) {
2368 if (other == disk_idx)
2369 continue;
2370 if (!test_bit(R5_UPTODATE,
2371 &sh->dev[other].flags))
2372 break;
a4456856 2373 }
5599becc
YT		 2374 BUG_ON(other < 0);
2375 pr_debug("Computing stripe %llu blocks %d,%d\n",
2376 (unsigned long long)sh->sector,
2377 disk_idx, other);
2378 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2379 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2380 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2381 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2382 sh->ops.target = disk_idx;
2383 sh->ops.target2 = other;
2384 s->uptodate += 2;
2385 s->req_compute = 1;
2386 return 1;
2387 } else if (test_bit(R5_Insync, &dev->flags)) {
2388 set_bit(R5_LOCKED, &dev->flags);
2389 set_bit(R5_Wantread, &dev->flags);
2390 s->locked++;
2391 pr_debug("Reading block %d (sync=%d)\n",
2392 disk_idx, s->syncing);
a4456856
DW		 2393 }
2394 }
5599becc
YT		 2395
2396 return 0;
2397}
2398
2399/**
93b3dbce 2400 * handle_stripe_fill - read or compute data to satisfy pending requests.
5599becc 2401 */
93b3dbce
N		 2402static void handle_stripe_fill(struct stripe_head *sh,
2403 struct stripe_head_state *s,
2404 int disks)
5599becc
YT		 2405{
2406 int i;
2407
2408 /* look for blocks to read/compute, skip this if a compute
2409 * is already in flight, or if the stripe contents are in the
2410 * midst of changing due to a write
2411 */
2412 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2413 !sh->reconstruct_state)
2414 for (i = disks; i--; )
93b3dbce 2415 if (fetch_block(sh, s, i, disks))
5599becc 2416 break;
a4456856
DW		 2417 set_bit(STRIPE_HANDLE, &sh->state);
2418}
2419
2420
1fe797e6 2421/* handle_stripe_clean_event
a4456856
DW		 2422 * any written block on an uptodate or failed drive can be returned.
2423 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2424 * never LOCKED, so we don't need to test 'failed' directly.
2425 */
1fe797e6 2426static void handle_stripe_clean_event(raid5_conf_t *conf,
a4456856
DW		 2427 struct stripe_head *sh, int disks, struct bio **return_bi)
2428{
2429 int i;
2430 struct r5dev *dev;
2431
2432 for (i = disks; i--; )
2433 if (sh->dev[i].written) {
2434 dev = &sh->dev[i];
2435 if (!test_bit(R5_LOCKED, &dev->flags) &&
2436 test_bit(R5_UPTODATE, &dev->flags)) {
2437 /* We can return any write requests */
2438 struct bio *wbi, *wbi2;
2439 int bitmap_end = 0;
45b4233c 2440 pr_debug("Return write for disc %d\n", i);
a4456856
DW		 2441 spin_lock_irq(&conf->device_lock);
2442 wbi = dev->written;
2443 dev->written = NULL;
2444 while (wbi && wbi->bi_sector <
2445 dev->sector + STRIPE_SECTORS) {
2446 wbi2 = r5_next_bio(wbi, dev->sector);
960e739d 2447 if (!raid5_dec_bi_phys_segments(wbi)) {
a4456856
DW		 2448 md_write_end(conf->mddev);
2449 wbi->bi_next = *return_bi;
2450 *return_bi = wbi;
2451 }
2452 wbi = wbi2;
2453 }
2454 if (dev->towrite == NULL)
2455 bitmap_end = 1;
2456 spin_unlock_irq(&conf->device_lock);
2457 if (bitmap_end)
2458 bitmap_endwrite(conf->mddev->bitmap,
2459 sh->sector,
2460 STRIPE_SECTORS,
2461 !test_bit(STRIPE_DEGRADED, &sh->state),
2462 0);
2463 }
2464 }
8b3e6cdc
DW		 2465
2466 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2467 if (atomic_dec_and_test(&conf->pending_full_writes))
2468 md_wakeup_thread(conf->mddev->thread);
a4456856
DW		 2469}
2470
c8ac1803
N		 2471static void handle_stripe_dirtying(raid5_conf_t *conf,
2472 struct stripe_head *sh,
2473 struct stripe_head_state *s,
2474 int disks)
a4456856
DW		 2475{
2476 int rmw = 0, rcw = 0, i;
c8ac1803
N		 2477 if (conf->max_degraded == 2) {
2478 /* RAID6 requires 'rcw' in current implementation
2479 * Calculate the real rcw later - for now fake it
2480 * look like rcw is cheaper
2481 */
2482 rcw = 1; rmw = 2;
2483 } else for (i = disks; i--; ) {
a4456856
DW		 2484 /* would I have to read this buffer for read_modify_write */
2485 struct r5dev *dev = &sh->dev[i];
2486 if ((dev->towrite || i == sh->pd_idx) &&
2487 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2488 !(test_bit(R5_UPTODATE, &dev->flags) ||
2489 test_bit(R5_Wantcompute, &dev->flags))) {
a4456856
DW		 2490 if (test_bit(R5_Insync, &dev->flags))
2491 rmw++;
2492 else
2493 rmw += 2*disks; /* cannot read it */
2494 }
2495 /* Would I have to read this buffer for reconstruct_write */
2496 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2497 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2498 !(test_bit(R5_UPTODATE, &dev->flags) ||
2499 test_bit(R5_Wantcompute, &dev->flags))) {
2500 if (test_bit(R5_Insync, &dev->flags)) rcw++;
a4456856
DW		 2501 else
2502 rcw += 2*disks;
2503 }
2504 }
45b4233c 2505 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
a4456856
DW		 2506 (unsigned long long)sh->sector, rmw, rcw);
2507 set_bit(STRIPE_HANDLE, &sh->state);
2508 if (rmw < rcw && rmw > 0)
2509 /* prefer read-modify-write, but need to get some data */
2510 for (i = disks; i--; ) {
2511 struct r5dev *dev = &sh->dev[i];
2512 if ((dev->towrite || i == sh->pd_idx) &&
2513 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2514 !(test_bit(R5_UPTODATE, &dev->flags) ||
2515 test_bit(R5_Wantcompute, &dev->flags)) &&
a4456856
DW		 2516 test_bit(R5_Insync, &dev->flags)) {
2517 if (
2518 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 2519 pr_debug("Read_old block "
a4456856
DW		 2520 "%d for r-m-w\n", i);
2521 set_bit(R5_LOCKED, &dev->flags);
2522 set_bit(R5_Wantread, &dev->flags);
2523 s->locked++;
2524 } else {
2525 set_bit(STRIPE_DELAYED, &sh->state);
2526 set_bit(STRIPE_HANDLE, &sh->state);
2527 }
2528 }
2529 }
c8ac1803 2530 if (rcw <= rmw && rcw > 0) {
a4456856 2531 /* want reconstruct write, but need to get some data */
c8ac1803 2532 rcw = 0;
a4456856
DW		 2533 for (i = disks; i--; ) {
2534 struct r5dev *dev = &sh->dev[i];
2535 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
c8ac1803 2536 i != sh->pd_idx && i != sh->qd_idx &&
a4456856 2537 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219 2538 !(test_bit(R5_UPTODATE, &dev->flags) ||
c8ac1803
N		 2539 test_bit(R5_Wantcompute, &dev->flags))) {
2540 rcw++;
2541 if (!test_bit(R5_Insync, &dev->flags))
2542 continue; /* it's a failed drive */
a4456856
DW		 2543 if (
2544 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 2545 pr_debug("Read_old block "
a4456856
DW		 2546 "%d for Reconstruct\n", i);
2547 set_bit(R5_LOCKED, &dev->flags);
2548 set_bit(R5_Wantread, &dev->flags);
2549 s->locked++;
2550 } else {
2551 set_bit(STRIPE_DELAYED, &sh->state);
2552 set_bit(STRIPE_HANDLE, &sh->state);
2553 }
2554 }
2555 }
c8ac1803 2556 }
a4456856
DW		 2557 /* now if nothing is locked, and if we have enough data,
2558 * we can start a write request
2559 */
f38e1219
DW		 2560 /* since handle_stripe can be called at any time we need to handle the
2561 * case where a compute block operation has been submitted and then a
ac6b53b6
DW		 2562 * subsequent call wants to start a write request. raid_run_ops only
2563 * handles the case where compute block and reconstruct are requested
f38e1219
DW		 2564 * simultaneously. If this is not the case then new writes need to be
2565 * held off until the compute completes.
2566 */
976ea8d4
DW		 2567 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2568 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2569 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
c0f7bddb 2570 schedule_reconstruction(sh, s, rcw == 0, 0);
a4456856
DW		 2571}
2572
a4456856
DW		 2573static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2574 struct stripe_head_state *s, int disks)
2575{
ecc65c9b 2576 struct r5dev *dev = NULL;
bd2ab670 2577
a4456856 2578 set_bit(STRIPE_HANDLE, &sh->state);
e89f8962 2579
ecc65c9b
DW		 2580 switch (sh->check_state) {
2581 case check_state_idle:
2582 /* start a new check operation if there are no failures */
bd2ab670 2583 if (s->failed == 0) {
bd2ab670 2584 BUG_ON(s->uptodate != disks);
ecc65c9b
DW		 2585 sh->check_state = check_state_run;
2586 set_bit(STRIPE_OP_CHECK, &s->ops_request);
bd2ab670 2587 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
bd2ab670 2588 s->uptodate--;
ecc65c9b 2589 break;
bd2ab670 2590 }
f2b3b44d 2591 dev = &sh->dev[s->failed_num[0]];
ecc65c9b
DW		 2592 /* fall through */
2593 case check_state_compute_result:
2594 sh->check_state = check_state_idle;
2595 if (!dev)
2596 dev = &sh->dev[sh->pd_idx];
2597
2598 /* check that a write has not made the stripe insync */
2599 if (test_bit(STRIPE_INSYNC, &sh->state))
2600 break;
c8894419 2601
a4456856 2602 /* either failed parity check, or recovery is happening */
a4456856
DW		 2603 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2604 BUG_ON(s->uptodate != disks);
2605
2606 set_bit(R5_LOCKED, &dev->flags);
ecc65c9b 2607 s->locked++;
a4456856 2608 set_bit(R5_Wantwrite, &dev->flags);
830ea016 2609
a4456856 2610 clear_bit(STRIPE_DEGRADED, &sh->state);
a4456856 2611 set_bit(STRIPE_INSYNC, &sh->state);
ecc65c9b
DW		 2612 break;
2613 case check_state_run:
2614 break; /* we will be called again upon completion */
2615 case check_state_check_result:
2616 sh->check_state = check_state_idle;
2617
2618 /* if a failure occurred during the check operation, leave
2619 * STRIPE_INSYNC not set and let the stripe be handled again
2620 */
2621 if (s->failed)
2622 break;
2623
2624 /* handle a successful check operation, if parity is correct
2625 * we are done. Otherwise update the mismatch count and repair
2626 * parity if !MD_RECOVERY_CHECK
2627 */
ad283ea4 2628 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
ecc65c9b
DW		 2629 /* parity is correct (on disc,
2630 * not in buffer any more)
2631 */
2632 set_bit(STRIPE_INSYNC, &sh->state);
2633 else {
2634 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2635 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2636 /* don't try to repair!! */
2637 set_bit(STRIPE_INSYNC, &sh->state);
2638 else {
2639 sh->check_state = check_state_compute_run;
976ea8d4 2640 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
ecc65c9b
DW		 2641 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2642 set_bit(R5_Wantcompute,
2643 &sh->dev[sh->pd_idx].flags);
2644 sh->ops.target = sh->pd_idx;
ac6b53b6 2645 sh->ops.target2 = -1;
ecc65c9b
DW		 2646 s->uptodate++;
2647 }
2648 }
2649 break;
2650 case check_state_compute_run:
2651 break;
2652 default:
2653 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2654 __func__, sh->check_state,
2655 (unsigned long long) sh->sector);
2656 BUG();
a4456856
DW		 2657 }
2658}
2659
2660
2661static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
36d1c647 2662 struct stripe_head_state *s,
f2b3b44d 2663 int disks)
a4456856 2664{
a4456856 2665 int pd_idx = sh->pd_idx;
34e04e87 2666 int qd_idx = sh->qd_idx;
d82dfee0 2667 struct r5dev *dev;
a4456856
DW		 2668
2669 set_bit(STRIPE_HANDLE, &sh->state);
2670
2671 BUG_ON(s->failed > 2);
d82dfee0 2672
a4456856
DW		 2673 /* Want to check and possibly repair P and Q.
2674 * However there could be one 'failed' device, in which
2675 * case we can only check one of them, possibly using the
2676 * other to generate missing data
2677 */
2678
d82dfee0
DW		 2679 switch (sh->check_state) {
2680 case check_state_idle:
2681 /* start a new check operation if there are < 2 failures */
f2b3b44d 2682 if (s->failed == s->q_failed) {
d82dfee0 2683 /* The only possible failed device holds Q, so it
a4456856
DW		 2684 * makes sense to check P (If anything else were failed,
2685 * we would have used P to recreate it).
2686 */
d82dfee0 2687 sh->check_state = check_state_run;
a4456856 2688 }
f2b3b44d 2689 if (!s->q_failed && s->failed < 2) {
d82dfee0 2690 /* Q is not failed, and we didn't use it to generate
a4456856
DW		 2691 * anything, so it makes sense to check it
2692 */
d82dfee0
DW		 2693 if (sh->check_state == check_state_run)
2694 sh->check_state = check_state_run_pq;
2695 else
2696 sh->check_state = check_state_run_q;
a4456856 2697 }
a4456856 2698
d82dfee0
DW		 2699 /* discard potentially stale zero_sum_result */
2700 sh->ops.zero_sum_result = 0;
a4456856 2701
d82dfee0
DW		 2702 if (sh->check_state == check_state_run) {
2703 /* async_xor_zero_sum destroys the contents of P */
2704 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2705 s->uptodate--;
a4456856 2706 }
d82dfee0
DW		 2707 if (sh->check_state >= check_state_run &&
2708 sh->check_state <= check_state_run_pq) {
2709 /* async_syndrome_zero_sum preserves P and Q, so
2710 * no need to mark them !uptodate here
2711 */
2712 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2713 break;
a4456856
DW		 2714 }
2715
d82dfee0
DW		 2716 /* we have 2-disk failure */
2717 BUG_ON(s->failed != 2);
2718 /* fall through */
2719 case check_state_compute_result:
2720 sh->check_state = check_state_idle;
a4456856 2721
d82dfee0
DW		 2722 /* check that a write has not made the stripe insync */
2723 if (test_bit(STRIPE_INSYNC, &sh->state))
2724 break;
a4456856
DW		 2725
2726 /* now write out any block on a failed drive,
d82dfee0 2727 * or P or Q if they were recomputed
a4456856 2728 */
d82dfee0 2729 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
a4456856 2730 if (s->failed == 2) {
f2b3b44d 2731 dev = &sh->dev[s->failed_num[1]];
a4456856
DW		 2732 s->locked++;
2733 set_bit(R5_LOCKED, &dev->flags);
2734 set_bit(R5_Wantwrite, &dev->flags);
2735 }
2736 if (s->failed >= 1) {
f2b3b44d 2737 dev = &sh->dev[s->failed_num[0]];
a4456856
DW		 2738 s->locked++;
2739 set_bit(R5_LOCKED, &dev->flags);
2740 set_bit(R5_Wantwrite, &dev->flags);
2741 }
d82dfee0 2742 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
a4456856
DW		 2743 dev = &sh->dev[pd_idx];
2744 s->locked++;
2745 set_bit(R5_LOCKED, &dev->flags);
2746 set_bit(R5_Wantwrite, &dev->flags);
2747 }
d82dfee0 2748 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
a4456856
DW		 2749 dev = &sh->dev[qd_idx];
2750 s->locked++;
2751 set_bit(R5_LOCKED, &dev->flags);
2752 set_bit(R5_Wantwrite, &dev->flags);
2753 }
2754 clear_bit(STRIPE_DEGRADED, &sh->state);
2755
2756 set_bit(STRIPE_INSYNC, &sh->state);
d82dfee0
DW		 2757 break;
2758 case check_state_run:
2759 case check_state_run_q:
2760 case check_state_run_pq:
2761 break; /* we will be called again upon completion */
2762 case check_state_check_result:
2763 sh->check_state = check_state_idle;
2764
2765 /* handle a successful check operation, if parity is correct
2766 * we are done. Otherwise update the mismatch count and repair
2767 * parity if !MD_RECOVERY_CHECK
2768 */
2769 if (sh->ops.zero_sum_result == 0) {
2770 /* both parities are correct */
2771 if (!s->failed)
2772 set_bit(STRIPE_INSYNC, &sh->state);
2773 else {
2774 /* in contrast to the raid5 case we can validate
2775 * parity, but still have a failure to write
2776 * back
2777 */
2778 sh->check_state = check_state_compute_result;
2779 /* Returning at this point means that we may go
2780 * off and bring p and/or q uptodate again so
2781 * we make sure to check zero_sum_result again
2782 * to verify if p or q need writeback
2783 */
2784 }
2785 } else {
2786 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2787 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2788 /* don't try to repair!! */
2789 set_bit(STRIPE_INSYNC, &sh->state);
2790 else {
2791 int *target = &sh->ops.target;
2792
2793 sh->ops.target = -1;
2794 sh->ops.target2 = -1;
2795 sh->check_state = check_state_compute_run;
2796 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2797 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2798 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2799 set_bit(R5_Wantcompute,
2800 &sh->dev[pd_idx].flags);
2801 *target = pd_idx;
2802 target = &sh->ops.target2;
2803 s->uptodate++;
2804 }
2805 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2806 set_bit(R5_Wantcompute,
2807 &sh->dev[qd_idx].flags);
2808 *target = qd_idx;
2809 s->uptodate++;
2810 }
2811 }
2812 }
2813 break;
2814 case check_state_compute_run:
2815 break;
2816 default:
2817 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2818 __func__, sh->check_state,
2819 (unsigned long long) sh->sector);
2820 BUG();
a4456856
DW		 2821 }
2822}
2823
86c374ba 2824static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh)
a4456856
DW		 2825{
2826 int i;
2827
2828 /* We have read all the blocks in this stripe and now we need to
2829 * copy some of them into a target stripe for expand.
2830 */
f0a50d37 2831 struct dma_async_tx_descriptor *tx = NULL;
a4456856
DW		 2832 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2833 for (i = 0; i < sh->disks; i++)
34e04e87 2834 if (i != sh->pd_idx && i != sh->qd_idx) {
911d4ee8 2835 int dd_idx, j;
a4456856 2836 struct stripe_head *sh2;
a08abd8c 2837 struct async_submit_ctl submit;
a4456856 2838
784052ec 2839 sector_t bn = compute_blocknr(sh, i, 1);
911d4ee8
N		 2840 sector_t s = raid5_compute_sector(conf, bn, 0,
2841 &dd_idx, NULL);
a8c906ca 2842 sh2 = get_active_stripe(conf, s, 0, 1, 1);
a4456856
DW		 2843 if (sh2 == NULL)
2844 /* so far only the early blocks of this stripe
2845 * have been requested. When later blocks
2846 * get requested, we will try again
2847 */
2848 continue;
2849 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2850 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2851 /* must have already done this block */
2852 release_stripe(sh2);
2853 continue;
2854 }
f0a50d37
DW		 2855
2856 /* place all the copies on one channel */
a08abd8c 2857 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
f0a50d37 2858 tx = async_memcpy(sh2->dev[dd_idx].page,
88ba2aa5 2859 sh->dev[i].page, 0, 0, STRIPE_SIZE,
a08abd8c 2860 &submit);
f0a50d37 2861
a4456856
DW		 2862 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2863 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2864 for (j = 0; j < conf->raid_disks; j++)
2865 if (j != sh2->pd_idx &&
86c374ba 2866 j != sh2->qd_idx &&
a4456856
DW		 2867 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2868 break;
2869 if (j == conf->raid_disks) {
2870 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2871 set_bit(STRIPE_HANDLE, &sh2->state);
2872 }
2873 release_stripe(sh2);
f0a50d37 2874
a4456856 2875 }
a2e08551
N		 2876 /* done submitting copies, wait for them to complete */
2877 if (tx) {
2878 async_tx_ack(tx);
2879 dma_wait_for_async_tx(tx);
2880 }
a4456856 2881}
1da177e4 2882
6bfe0b49 2883
1da177e4
LT		 2884/*
2885 * handle_stripe - do things to a stripe.
2886 *
2887 * We lock the stripe and then examine the state of various bits
2888 * to see what needs to be done.
2889 * Possible results:
2890 * return some read request which now have data
2891 * return some write requests which are safely on disc
2892 * schedule a read on some buffers
2893 * schedule a write of some buffers
2894 * return confirmation of parity correctness
2895 *
1da177e4
LT		 2896 * buffers are taken off read_list or write_list, and bh_cache buffers
2897 * get BH_Lock set before the stripe lock is released.
2898 *
2899 */
a4456856 2900
acfe726b 2901static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
1da177e4 2902{
bff61975 2903 raid5_conf_t *conf = sh->raid_conf;
f416885e 2904 int disks = sh->disks;
474af965
N		 2905 struct r5dev *dev;
2906 int i;
1da177e4 2907
acfe726b
N		 2908 memset(s, 0, sizeof(*s));
2909
2910 s->syncing = test_bit(STRIPE_SYNCING, &sh->state);
2911 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2912 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
2913 s->failed_num[0] = -1;
2914 s->failed_num[1] = -1;
1da177e4 2915
acfe726b 2916 /* Now to look around and see what can be done */
1da177e4 2917 rcu_read_lock();
c4c1663b 2918 spin_lock_irq(&conf->device_lock);
16a53ecc
N		 2919 for (i=disks; i--; ) {
2920 mdk_rdev_t *rdev;
acfe726b 2921
16a53ecc 2922 dev = &sh->dev[i];
1da177e4 2923
45b4233c 2924 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
16a53ecc 2925 i, dev->flags, dev->toread, dev->towrite, dev->written);
6c0069c0
YT		 2926 /* maybe we can reply to a read
2927 *
2928 * new wantfill requests are only permitted while
2929 * ops_complete_biofill is guaranteed to be inactive
2930 */
2931 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
2932 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
2933 set_bit(R5_Wantfill, &dev->flags);
1da177e4 2934
16a53ecc 2935 /* now count some things */
cc94015a
N		 2936 if (test_bit(R5_LOCKED, &dev->flags))
2937 s->locked++;
2938 if (test_bit(R5_UPTODATE, &dev->flags))
2939 s->uptodate++;
2d6e4ecc 2940 if (test_bit(R5_Wantcompute, &dev->flags)) {
cc94015a
N		 2941 s->compute++;
2942 BUG_ON(s->compute > 2);
2d6e4ecc 2943 }
1da177e4 2944
acfe726b 2945 if (test_bit(R5_Wantfill, &dev->flags))
cc94015a 2946 s->to_fill++;
acfe726b 2947 else if (dev->toread)
cc94015a 2948 s->to_read++;
16a53ecc 2949 if (dev->towrite) {
cc94015a 2950 s->to_write++;
16a53ecc 2951 if (!test_bit(R5_OVERWRITE, &dev->flags))
cc94015a 2952 s->non_overwrite++;
16a53ecc 2953 }
a4456856 2954 if (dev->written)
cc94015a 2955 s->written++;
16a53ecc 2956 rdev = rcu_dereference(conf->disks[i].rdev);
cc94015a 2957 if (s->blocked_rdev == NULL &&
ac4090d2 2958 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
cc94015a 2959 s->blocked_rdev = rdev;
6bfe0b49 2960 atomic_inc(&rdev->nr_pending);
6bfe0b49 2961 }
415e72d0
N		 2962 clear_bit(R5_Insync, &dev->flags);
2963 if (!rdev)
2964 /* Not in-sync */;
2965 else if (test_bit(In_sync, &rdev->flags))
2966 set_bit(R5_Insync, &dev->flags);
2967 else {
2968 /* in sync if before recovery_offset */
2969 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
2970 set_bit(R5_Insync, &dev->flags);
2971 }
2972 if (!test_bit(R5_Insync, &dev->flags)) {
16a53ecc
N		 2973 /* The ReadError flag will just be confusing now */
2974 clear_bit(R5_ReadError, &dev->flags);
2975 clear_bit(R5_ReWrite, &dev->flags);
1da177e4 2976 }
415e72d0
N		 2977 if (test_bit(R5_ReadError, &dev->flags))
2978 clear_bit(R5_Insync, &dev->flags);
2979 if (!test_bit(R5_Insync, &dev->flags)) {
cc94015a
N		 2980 if (s->failed < 2)
2981 s->failed_num[s->failed] = i;
2982 s->failed++;
415e72d0 2983 }
1da177e4 2984 }
c4c1663b 2985 spin_unlock_irq(&conf->device_lock);
1da177e4 2986 rcu_read_unlock();
cc94015a
N		 2987}
2988
2989static void handle_stripe(struct stripe_head *sh)
2990{
2991 struct stripe_head_state s;
474af965 2992 raid5_conf_t *conf = sh->raid_conf;
3687c061 2993 int i;
84789554
N		 2994 int prexor;
2995 int disks = sh->disks;
474af965 2996 struct r5dev *pdev, *qdev;
cc94015a
N		 2997
2998 clear_bit(STRIPE_HANDLE, &sh->state);
2999 if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) {
3000 /* already being handled, ensure it gets handled
3001 * again when current action finishes */
3002 set_bit(STRIPE_HANDLE, &sh->state);
3003 return;
3004 }
3005
3006 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3007 set_bit(STRIPE_SYNCING, &sh->state);
3008 clear_bit(STRIPE_INSYNC, &sh->state);
3009 }
3010 clear_bit(STRIPE_DELAYED, &sh->state);
3011
3012 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3013 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3014 (unsigned long long)sh->sector, sh->state,
3015 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
3016 sh->check_state, sh->reconstruct_state);
3687c061 3017
acfe726b 3018 analyse_stripe(sh, &s);
c5a31000 3019
474af965
N		 3020 if (unlikely(s.blocked_rdev)) {
3021 if (s.syncing || s.expanding || s.expanded ||
3022 s.to_write || s.written) {
3023 set_bit(STRIPE_HANDLE, &sh->state);
3024 goto finish;
3025 }
3026 /* There is nothing for the blocked_rdev to block */
3027 rdev_dec_pending(s.blocked_rdev, conf->mddev);
3028 s.blocked_rdev = NULL;
3029 }
3030
3031 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3032 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3033 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3034 }
3035
3036 pr_debug("locked=%d uptodate=%d to_read=%d"
3037 " to_write=%d failed=%d failed_num=%d,%d\n",
3038 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3039 s.failed_num[0], s.failed_num[1]);
3040 /* check if the array has lost more than max_degraded devices and,
3041 * if so, some requests might need to be failed.
3042 */
3043 if (s.failed > conf->max_degraded && s.to_read+s.to_write+s.written)
3044 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
3045 if (s.failed > conf->max_degraded && s.syncing) {
3046 md_done_sync(conf->mddev, STRIPE_SECTORS, 0);
3047 clear_bit(STRIPE_SYNCING, &sh->state);
3048 s.syncing = 0;
3049 }
3050
3051 /*
3052 * might be able to return some write requests if the parity blocks
3053 * are safe, or on a failed drive
3054 */
3055 pdev = &sh->dev[sh->pd_idx];
3056 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
3057 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
3058 qdev = &sh->dev[sh->qd_idx];
3059 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
3060 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
3061 || conf->level < 6;
3062
3063 if (s.written &&
3064 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3065 && !test_bit(R5_LOCKED, &pdev->flags)
3066 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3067 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3068 && !test_bit(R5_LOCKED, &qdev->flags)
3069 && test_bit(R5_UPTODATE, &qdev->flags)))))
3070 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
3071
3072 /* Now we might consider reading some blocks, either to check/generate
3073 * parity, or to satisfy requests
3074 * or to load a block that is being partially written.
3075 */
3076 if (s.to_read || s.non_overwrite
3077 || (conf->level == 6 && s.to_write && s.failed)
3078 || (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
3079 handle_stripe_fill(sh, &s, disks);
3080
84789554
N		 3081 /* Now we check to see if any write operations have recently
3082 * completed
3083 */
3084 prexor = 0;
3085 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3086 prexor = 1;
3087 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3088 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3089 sh->reconstruct_state = reconstruct_state_idle;
3090
3091 /* All the 'written' buffers and the parity block are ready to
3092 * be written back to disk
3093 */
3094 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3095 BUG_ON(sh->qd_idx >= 0 &&
3096 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags));
3097 for (i = disks; i--; ) {
3098 struct r5dev *dev = &sh->dev[i];
3099 if (test_bit(R5_LOCKED, &dev->flags) &&
3100 (i == sh->pd_idx || i == sh->qd_idx ||
3101 dev->written)) {
3102 pr_debug("Writing block %d\n", i);
3103 set_bit(R5_Wantwrite, &dev->flags);
3104 if (prexor)
3105 continue;
3106 if (!test_bit(R5_Insync, &dev->flags) ||
3107 ((i == sh->pd_idx || i == sh->qd_idx) &&
3108 s.failed == 0))
3109 set_bit(STRIPE_INSYNC, &sh->state);
3110 }
3111 }
3112 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3113 s.dec_preread_active = 1;
3114 }
3115
3116 /* Now to consider new write requests and what else, if anything
3117 * should be read. We do not handle new writes when:
3118 * 1/ A 'write' operation (copy+xor) is already in flight.
3119 * 2/ A 'check' operation is in flight, as it may clobber the parity
3120 * block.
3121 */
3122 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3123 handle_stripe_dirtying(conf, sh, &s, disks);
3124
3125 /* maybe we need to check and possibly fix the parity for this stripe
3126 * Any reads will already have been scheduled, so we just see if enough
3127 * data is available. The parity check is held off while parity
3128 * dependent operations are in flight.
3129 */
3130 if (sh->check_state ||
3131 (s.syncing && s.locked == 0 &&
3132 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3133 !test_bit(STRIPE_INSYNC, &sh->state))) {
3134 if (conf->level == 6)
3135 handle_parity_checks6(conf, sh, &s, disks);
3136 else
3137 handle_parity_checks5(conf, sh, &s, disks);
3138 }
c5a31000
N		 3139
3140 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3141 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3142 clear_bit(STRIPE_SYNCING, &sh->state);
3143 }
3144
3145 /* If the failed drives are just a ReadError, then we might need
3146 * to progress the repair/check process
3147 */
3148 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
3149 for (i = 0; i < s.failed; i++) {
3150 struct r5dev *dev = &sh->dev[s.failed_num[i]];
3151 if (test_bit(R5_ReadError, &dev->flags)
3152 && !test_bit(R5_LOCKED, &dev->flags)
3153 && test_bit(R5_UPTODATE, &dev->flags)
3154 ) {
3155 if (!test_bit(R5_ReWrite, &dev->flags)) {
3156 set_bit(R5_Wantwrite, &dev->flags);
3157 set_bit(R5_ReWrite, &dev->flags);
3158 set_bit(R5_LOCKED, &dev->flags);
3159 s.locked++;
3160 } else {
3161 /* let's read it back */
3162 set_bit(R5_Wantread, &dev->flags);
3163 set_bit(R5_LOCKED, &dev->flags);
3164 s.locked++;
3165 }
3166 }
3167 }
3168
3169
3687c061
N		 3170 /* Finish reconstruct operations initiated by the expansion process */
3171 if (sh->reconstruct_state == reconstruct_state_result) {
3172 struct stripe_head *sh_src
3173 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3174 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
3175 /* sh cannot be written until sh_src has been read.
3176 * so arrange for sh to be delayed a little
3177 */
3178 set_bit(STRIPE_DELAYED, &sh->state);
3179 set_bit(STRIPE_HANDLE, &sh->state);
3180 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3181 &sh_src->state))
3182 atomic_inc(&conf->preread_active_stripes);
3183 release_stripe(sh_src);
3184 goto finish;
3185 }
3186 if (sh_src)
3187 release_stripe(sh_src);
3188
3189 sh->reconstruct_state = reconstruct_state_idle;
3190 clear_bit(STRIPE_EXPANDING, &sh->state);
3191 for (i = conf->raid_disks; i--; ) {
3192 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3193 set_bit(R5_LOCKED, &sh->dev[i].flags);
3194 s.locked++;
3195 }
3196 }
f416885e 3197
3687c061
N		 3198 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3199 !sh->reconstruct_state) {
3200 /* Need to write out all blocks after computing parity */
3201 sh->disks = conf->raid_disks;
3202 stripe_set_idx(sh->sector, conf, 0, sh);
3203 schedule_reconstruction(sh, &s, 1, 1);
3204 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3205 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3206 atomic_dec(&conf->reshape_stripes);
3207 wake_up(&conf->wait_for_overlap);
3208 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3209 }
3210
3211 if (s.expanding && s.locked == 0 &&
3212 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3213 handle_stripe_expansion(conf, sh);
16a53ecc 3214
3687c061 3215finish:
6bfe0b49 3216 /* wait for this device to become unblocked */
c5709ef6
N		 3217 if (unlikely(s.blocked_rdev))
3218 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);
6bfe0b49 3219
6c0069c0
YT		 3220 if (s.ops_request)
3221 raid_run_ops(sh, s.ops_request);
3222
f0e43bcd 3223 ops_run_io(sh, &s);
16a53ecc 3224
729a1866 3225
c5709ef6 3226 if (s.dec_preread_active) {
729a1866 3227 /* We delay this until after ops_run_io so that if make_request
e9c7469b 3228 * is waiting on a flush, it won't continue until the writes
729a1866
N		 3229 * have actually been submitted.
3230 */
3231 atomic_dec(&conf->preread_active_stripes);
3232 if (atomic_read(&conf->preread_active_stripes) <
3233 IO_THRESHOLD)
3234 md_wakeup_thread(conf->mddev->thread);
3235 }
3236
c5709ef6 3237 return_io(s.return_bi);
16a53ecc 3238
c4c1663b 3239 clear_bit(STRIPE_ACTIVE, &sh->state);
16a53ecc
N		 3240}
3241
16a53ecc
N		 3242static void raid5_activate_delayed(raid5_conf_t *conf)
3243{
3244 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3245 while (!list_empty(&conf->delayed_list)) {
3246 struct list_head *l = conf->delayed_list.next;
3247 struct stripe_head *sh;
3248 sh = list_entry(l, struct stripe_head, lru);
3249 list_del_init(l);
3250 clear_bit(STRIPE_DELAYED, &sh->state);
3251 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3252 atomic_inc(&conf->preread_active_stripes);
8b3e6cdc 3253 list_add_tail(&sh->lru, &conf->hold_list);
16a53ecc 3254 }
482c0834 3255 }
16a53ecc
N		 3256}
3257
3258static void activate_bit_delay(raid5_conf_t *conf)
3259{
3260 /* device_lock is held */
3261 struct list_head head;
3262 list_add(&head, &conf->bitmap_list);
3263 list_del_init(&conf->bitmap_list);
3264 while (!list_empty(&head)) {
3265 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3266 list_del_init(&sh->lru);
3267 atomic_inc(&sh->count);
3268 __release_stripe(conf, sh);
3269 }
3270}
3271
11d8a6e3 3272int md_raid5_congested(mddev_t *mddev, int bits)
f022b2fd 3273{
070ec55d 3274 raid5_conf_t *conf = mddev->private;
f022b2fd
N		 3275
3276 /* No difference between reads and writes. Just check
3277 * how busy the stripe_cache is
3278 */
3fa841d7 3279
f022b2fd
N		 3280 if (conf->inactive_blocked)
3281 return 1;
3282 if (conf->quiesce)
3283 return 1;
3284 if (list_empty_careful(&conf->inactive_list))
3285 return 1;
3286
3287 return 0;
3288}
11d8a6e3
N		 3289EXPORT_SYMBOL_GPL(md_raid5_congested);
3290
3291static int raid5_congested(void *data, int bits)
3292{
3293 mddev_t *mddev = data;
3294
3295 return mddev_congested(mddev, bits) ||
3296 md_raid5_congested(mddev, bits);
3297}
f022b2fd 3298
23032a0e
RBJ		 3299/* We want read requests to align with chunks where possible,
3300 * but write requests don't need to.
3301 */
cc371e66
AK		 3302static int raid5_mergeable_bvec(struct request_queue *q,
3303 struct bvec_merge_data *bvm,
3304 struct bio_vec *biovec)
23032a0e
RBJ		 3305{
3306 mddev_t *mddev = q->queuedata;
cc371e66 3307 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
23032a0e 3308 int max;
9d8f0363 3309 unsigned int chunk_sectors = mddev->chunk_sectors;
cc371e66 3310 unsigned int bio_sectors = bvm->bi_size >> 9;
23032a0e 3311
cc371e66 3312 if ((bvm->bi_rw & 1) == WRITE)
23032a0e
RBJ		 3313 return biovec->bv_len; /* always allow writes to be mergeable */
3314
664e7c41
AN		 3315 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3316 chunk_sectors = mddev->new_chunk_sectors;
23032a0e
RBJ		 3317 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3318 if (max < 0) max = 0;
3319 if (max <= biovec->bv_len && bio_sectors == 0)
3320 return biovec->bv_len;
3321 else
3322 return max;
3323}
3324
f679623f
RBJ		 3325
3326static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3327{
3328 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
9d8f0363 3329 unsigned int chunk_sectors = mddev->chunk_sectors;
f679623f
RBJ		 3330 unsigned int bio_sectors = bio->bi_size >> 9;
3331
664e7c41
AN		 3332 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3333 chunk_sectors = mddev->new_chunk_sectors;
f679623f
RBJ		 3334 return chunk_sectors >=
3335 ((sector & (chunk_sectors - 1)) + bio_sectors);
3336}
3337
46031f9a
RBJ		 3338/*
3339 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3340 * later sampled by raid5d.
3341 */
3342static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3343{
3344 unsigned long flags;
3345
3346 spin_lock_irqsave(&conf->device_lock, flags);
3347
3348 bi->bi_next = conf->retry_read_aligned_list;
3349 conf->retry_read_aligned_list = bi;
3350
3351 spin_unlock_irqrestore(&conf->device_lock, flags);
3352 md_wakeup_thread(conf->mddev->thread);
3353}
3354
3355
3356static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3357{
3358 struct bio *bi;
3359
3360 bi = conf->retry_read_aligned;
3361 if (bi) {
3362 conf->retry_read_aligned = NULL;
3363 return bi;
3364 }
3365 bi = conf->retry_read_aligned_list;
3366 if(bi) {
387bb173 3367 conf->retry_read_aligned_list = bi->bi_next;
46031f9a 3368 bi->bi_next = NULL;
960e739d
JA		 3369 /*
3370 * this sets the active strip count to 1 and the processed
3371 * strip count to zero (upper 8 bits)
3372 */
46031f9a 3373 bi->bi_phys_segments = 1; /* biased count of active stripes */
46031f9a
RBJ		 3374 }
3375
3376 return bi;
3377}
3378
3379
f679623f
RBJ		 3380/*
3381 * The "raid5_align_endio" should check if the read succeeded and if it
3382 * did, call bio_endio on the original bio (having bio_put the new bio
3383 * first).
3384 * If the read failed..
3385 */
6712ecf8 3386static void raid5_align_endio(struct bio *bi, int error)
f679623f
RBJ		 3387{
3388 struct bio* raid_bi = bi->bi_private;
46031f9a
RBJ		 3389 mddev_t *mddev;
3390 raid5_conf_t *conf;
3391 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3392 mdk_rdev_t *rdev;
3393
f679623f 3394 bio_put(bi);
46031f9a 3395
46031f9a
RBJ		 3396 rdev = (void*)raid_bi->bi_next;
3397 raid_bi->bi_next = NULL;
2b7f2228
N		 3398 mddev = rdev->mddev;
3399 conf = mddev->private;
46031f9a
RBJ		 3400
3401 rdev_dec_pending(rdev, conf->mddev);
3402
3403 if (!error && uptodate) {
6712ecf8 3404 bio_endio(raid_bi, 0);
46031f9a
RBJ		 3405 if (atomic_dec_and_test(&conf->active_aligned_reads))
3406 wake_up(&conf->wait_for_stripe);
6712ecf8 3407 return;
46031f9a
RBJ		 3408 }
3409
3410
45b4233c 3411 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
46031f9a
RBJ		 3412
3413 add_bio_to_retry(raid_bi, conf);
f679623f
RBJ		 3414}
3415
387bb173
NB		 3416static int bio_fits_rdev(struct bio *bi)
3417{
165125e1 3418 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
387bb173 3419
ae03bf63 3420 if ((bi->bi_size>>9) > queue_max_sectors(q))
387bb173
NB		 3421 return 0;
3422 blk_recount_segments(q, bi);
8a78362c 3423 if (bi->bi_phys_segments > queue_max_segments(q))
387bb173
NB		 3424 return 0;
3425
3426 if (q->merge_bvec_fn)
3427 /* it's too hard to apply the merge_bvec_fn at this stage,
3428 * just just give up
3429 */
3430 return 0;
3431
3432 return 1;
3433}
3434
3435
21a52c6d 3436static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
f679623f 3437{
070ec55d 3438 raid5_conf_t *conf = mddev->private;
8553fe7e 3439 int dd_idx;
f679623f
RBJ		 3440 struct bio* align_bi;
3441 mdk_rdev_t *rdev;
3442
3443 if (!in_chunk_boundary(mddev, raid_bio)) {
45b4233c 3444 pr_debug("chunk_aligned_read : non aligned\n");
f679623f
RBJ		 3445 return 0;
3446 }
3447 /*
a167f663 3448 * use bio_clone_mddev to make a copy of the bio
f679623f 3449 */
a167f663 3450 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
f679623f
RBJ		 3451 if (!align_bi)
3452 return 0;
3453 /*
3454 * set bi_end_io to a new function, and set bi_private to the
3455 * original bio.
3456 */
3457 align_bi->bi_end_io = raid5_align_endio;
3458 align_bi->bi_private = raid_bio;
3459 /*
3460 * compute position
3461 */
112bf897
N		 3462 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3463 0,
911d4ee8 3464 &dd_idx, NULL);
f679623f
RBJ		 3465
3466 rcu_read_lock();
3467 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3468 if (rdev && test_bit(In_sync, &rdev->flags)) {
f679623f
RBJ		 3469 atomic_inc(&rdev->nr_pending);
3470 rcu_read_unlock();
46031f9a
RBJ		 3471 raid_bio->bi_next = (void*)rdev;
3472 align_bi->bi_bdev = rdev->bdev;
3473 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3474 align_bi->bi_sector += rdev->data_offset;
3475
387bb173
NB		 3476 if (!bio_fits_rdev(align_bi)) {
3477 /* too big in some way */
3478 bio_put(align_bi);
3479 rdev_dec_pending(rdev, mddev);
3480 return 0;
3481 }
3482
46031f9a
RBJ		 3483 spin_lock_irq(&conf->device_lock);
3484 wait_event_lock_irq(conf->wait_for_stripe,
3485 conf->quiesce == 0,
3486 conf->device_lock, /* nothing */);
3487 atomic_inc(&conf->active_aligned_reads);
3488 spin_unlock_irq(&conf->device_lock);
3489
f679623f
RBJ		 3490 generic_make_request(align_bi);
3491 return 1;
3492 } else {
3493 rcu_read_unlock();
46031f9a 3494 bio_put(align_bi);
f679623f
RBJ		 3495 return 0;
3496 }
3497}
3498
8b3e6cdc
DW		 3499/* __get_priority_stripe - get the next stripe to process
3500 *
3501 * Full stripe writes are allowed to pass preread active stripes up until
3502 * the bypass_threshold is exceeded. In general the bypass_count
3503 * increments when the handle_list is handled before the hold_list; however, it
3504 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3505 * stripe with in flight i/o. The bypass_count will be reset when the
3506 * head of the hold_list has changed, i.e. the head was promoted to the
3507 * handle_list.
3508 */
3509static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3510{
3511 struct stripe_head *sh;
3512
3513 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3514 __func__,
3515 list_empty(&conf->handle_list) ? "empty" : "busy",
3516 list_empty(&conf->hold_list) ? "empty" : "busy",
3517 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3518
3519 if (!list_empty(&conf->handle_list)) {
3520 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3521
3522 if (list_empty(&conf->hold_list))
3523 conf->bypass_count = 0;
3524 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3525 if (conf->hold_list.next == conf->last_hold)
3526 conf->bypass_count++;
3527 else {
3528 conf->last_hold = conf->hold_list.next;
3529 conf->bypass_count -= conf->bypass_threshold;
3530 if (conf->bypass_count < 0)
3531 conf->bypass_count = 0;
3532 }
3533 }
3534 } else if (!list_empty(&conf->hold_list) &&
3535 ((conf->bypass_threshold &&
3536 conf->bypass_count > conf->bypass_threshold) ||
3537 atomic_read(&conf->pending_full_writes) == 0)) {
3538 sh = list_entry(conf->hold_list.next,
3539 typeof(*sh), lru);
3540 conf->bypass_count -= conf->bypass_threshold;
3541 if (conf->bypass_count < 0)
3542 conf->bypass_count = 0;
3543 } else
3544 return NULL;
3545
3546 list_del_init(&sh->lru);
3547 atomic_inc(&sh->count);
3548 BUG_ON(atomic_read(&sh->count) != 1);
3549 return sh;
3550}
f679623f 3551
21a52c6d 3552static int make_request(mddev_t *mddev, struct bio * bi)
1da177e4 3553{
070ec55d 3554 raid5_conf_t *conf = mddev->private;
911d4ee8 3555 int dd_idx;
1da177e4
LT		 3556 sector_t new_sector;
3557 sector_t logical_sector, last_sector;
3558 struct stripe_head *sh;
a362357b 3559 const int rw = bio_data_dir(bi);
49077326 3560 int remaining;
7c13edc8 3561 int plugged;
1da177e4 3562
e9c7469b
TH		 3563 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
3564 md_flush_request(mddev, bi);
e5dcdd80
N		 3565 return 0;
3566 }
3567
3d310eb7 3568 md_write_start(mddev, bi);
06d91a5f 3569
802ba064 3570 if (rw == READ &&
52488615 3571 mddev->reshape_position == MaxSector &&
21a52c6d 3572 chunk_aligned_read(mddev,bi))
99c0fb5f 3573 return 0;
52488615 3574
1da177e4
LT		 3575 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3576 last_sector = bi->bi_sector + (bi->bi_size>>9);
3577 bi->bi_next = NULL;
3578 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
06d91a5f 3579
7c13edc8 3580 plugged = mddev_check_plugged(mddev);
1da177e4
LT		 3581 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3582 DEFINE_WAIT(w);
16a53ecc 3583 int disks, data_disks;
b5663ba4 3584 int previous;
b578d55f 3585
7ecaa1e6 3586 retry:
b5663ba4 3587 previous = 0;
b0f9ec04 3588 disks = conf->raid_disks;
b578d55f 3589 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
b0f9ec04 3590 if (unlikely(conf->reshape_progress != MaxSector)) {
fef9c61f 3591 /* spinlock is needed as reshape_progress may be
df8e7f76
N		 3592 * 64bit on a 32bit platform, and so it might be
3593 * possible to see a half-updated value
aeb878b0 3594 * Of course reshape_progress could change after
df8e7f76
N		 3595 * the lock is dropped, so once we get a reference
3596 * to the stripe that we think it is, we will have
3597 * to check again.
3598 */
7ecaa1e6 3599 spin_lock_irq(&conf->device_lock);
fef9c61f
N		 3600 if (mddev->delta_disks < 0
3601 ? logical_sector < conf->reshape_progress
3602 : logical_sector >= conf->reshape_progress) {
7ecaa1e6 3603 disks = conf->previous_raid_disks;
b5663ba4
N		 3604 previous = 1;
3605 } else {
fef9c61f
N		 3606 if (mddev->delta_disks < 0
3607 ? logical_sector < conf->reshape_safe
3608 : logical_sector >= conf->reshape_safe) {
b578d55f
N		 3609 spin_unlock_irq(&conf->device_lock);
3610 schedule();
3611 goto retry;
3612 }
3613 }
7ecaa1e6
N		 3614 spin_unlock_irq(&conf->device_lock);
3615 }
16a53ecc
N		 3616 data_disks = disks - conf->max_degraded;
3617
112bf897
N		 3618 new_sector = raid5_compute_sector(conf, logical_sector,
3619 previous,
911d4ee8 3620 &dd_idx, NULL);
0c55e022 3621 pr_debug("raid456: make_request, sector %llu logical %llu\n",
1da177e4
LT		 3622 (unsigned long long)new_sector,
3623 (unsigned long long)logical_sector);
3624
b5663ba4 3625 sh = get_active_stripe(conf, new_sector, previous,
a8c906ca 3626 (bi->bi_rw&RWA_MASK), 0);
1da177e4 3627 if (sh) {
b0f9ec04 3628 if (unlikely(previous)) {
7ecaa1e6 3629 /* expansion might have moved on while waiting for a
df8e7f76
N		 3630 * stripe, so we must do the range check again.
3631 * Expansion could still move past after this
3632 * test, but as we are holding a reference to
3633 * 'sh', we know that if that happens,
3634 * STRIPE_EXPANDING will get set and the expansion
3635 * won't proceed until we finish with the stripe.
7ecaa1e6
N		 3636 */
3637 int must_retry = 0;
3638 spin_lock_irq(&conf->device_lock);
b0f9ec04
N		 3639 if (mddev->delta_disks < 0
3640 ? logical_sector >= conf->reshape_progress
3641 : logical_sector < conf->reshape_progress)
7ecaa1e6
N		 3642 /* mismatch, need to try again */
3643 must_retry = 1;
3644 spin_unlock_irq(&conf->device_lock);
3645 if (must_retry) {
3646 release_stripe(sh);
7a3ab908 3647 schedule();
7ecaa1e6
N		 3648 goto retry;
3649 }
3650 }
e62e58a5 3651
ffd96e35 3652 if (rw == WRITE &&
a5c308d4 3653 logical_sector >= mddev->suspend_lo &&
e464eafd
N		 3654 logical_sector < mddev->suspend_hi) {
3655 release_stripe(sh);
e62e58a5
N		 3656 /* As the suspend_* range is controlled by
3657 * userspace, we want an interruptible
3658 * wait.
3659 */
3660 flush_signals(current);
3661 prepare_to_wait(&conf->wait_for_overlap,
3662 &w, TASK_INTERRUPTIBLE);
3663 if (logical_sector >= mddev->suspend_lo &&
3664 logical_sector < mddev->suspend_hi)
3665 schedule();
e464eafd
N		 3666 goto retry;
3667 }
7ecaa1e6
N		 3668
3669 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
ffd96e35 3670 !add_stripe_bio(sh, bi, dd_idx, rw)) {
7ecaa1e6
N		 3671 /* Stripe is busy expanding or
3672 * add failed due to overlap. Flush everything
1da177e4
LT		 3673 * and wait a while
3674 */
482c0834 3675 md_wakeup_thread(mddev->thread);
1da177e4
LT		 3676 release_stripe(sh);
3677 schedule();
3678 goto retry;
3679 }
3680 finish_wait(&conf->wait_for_overlap, &w);
6ed3003c
N		 3681 set_bit(STRIPE_HANDLE, &sh->state);
3682 clear_bit(STRIPE_DELAYED, &sh->state);
e9c7469b 3683 if ((bi->bi_rw & REQ_SYNC) &&
729a1866
N		 3684 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3685 atomic_inc(&conf->preread_active_stripes);
1da177e4 3686 release_stripe(sh);
1da177e4
LT		 3687 } else {
3688 /* cannot get stripe for read-ahead, just give-up */
3689 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3690 finish_wait(&conf->wait_for_overlap, &w);
3691 break;
3692 }
3693
3694 }
7c13edc8
N		 3695 if (!plugged)
3696 md_wakeup_thread(mddev->thread);
3697
1da177e4 3698 spin_lock_irq(&conf->device_lock);
960e739d 3699 remaining = raid5_dec_bi_phys_segments(bi);
f6344757
N		 3700 spin_unlock_irq(&conf->device_lock);
3701 if (remaining == 0) {
1da177e4 3702
16a53ecc 3703 if ( rw == WRITE )
1da177e4 3704 md_write_end(mddev);
6712ecf8 3705
0e13fe23 3706 bio_endio(bi, 0);
1da177e4 3707 }
729a1866 3708
1da177e4
LT		 3709 return 0;
3710}
3711
b522adcd
DW		 3712static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
3713
52c03291 3714static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
1da177e4 3715{
52c03291
N		 3716 /* reshaping is quite different to recovery/resync so it is
3717 * handled quite separately ... here.
3718 *
3719 * On each call to sync_request, we gather one chunk worth of
3720 * destination stripes and flag them as expanding.
3721 * Then we find all the source stripes and request reads.
3722 * As the reads complete, handle_stripe will copy the data
3723 * into the destination stripe and release that stripe.
3724 */
7b92813c 3725 raid5_conf_t *conf = mddev->private;
1da177e4 3726 struct stripe_head *sh;
ccfcc3c1 3727 sector_t first_sector, last_sector;
f416885e
N		 3728 int raid_disks = conf->previous_raid_disks;
3729 int data_disks = raid_disks - conf->max_degraded;
3730 int new_data_disks = conf->raid_disks - conf->max_degraded;
52c03291
N		 3731 int i;
3732 int dd_idx;
c8f517c4 3733 sector_t writepos, readpos, safepos;
ec32a2bd 3734 sector_t stripe_addr;
7a661381 3735 int reshape_sectors;
ab69ae12 3736 struct list_head stripes;
52c03291 3737
fef9c61f
N		 3738 if (sector_nr == 0) {
3739 /* If restarting in the middle, skip the initial sectors */
3740 if (mddev->delta_disks < 0 &&
3741 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
3742 sector_nr = raid5_size(mddev, 0, 0)
3743 - conf->reshape_progress;
a639755c 3744 } else if (mddev->delta_disks >= 0 &&
fef9c61f
N		 3745 conf->reshape_progress > 0)
3746 sector_nr = conf->reshape_progress;
f416885e 3747 sector_div(sector_nr, new_data_disks);
fef9c61f 3748 if (sector_nr) {
8dee7211
N		 3749 mddev->curr_resync_completed = sector_nr;
3750 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
fef9c61f
N		 3751 *skipped = 1;
3752 return sector_nr;
3753 }
52c03291
N		 3754 }
3755
7a661381
N		 3756 /* We need to process a full chunk at a time.
3757 * If old and new chunk sizes differ, we need to process the
3758 * largest of these
3759 */
664e7c41
AN		 3760 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
3761 reshape_sectors = mddev->new_chunk_sectors;
7a661381 3762 else
9d8f0363 3763 reshape_sectors = mddev->chunk_sectors;
7a661381 3764
52c03291
N		 3765 /* we update the metadata when there is more than 3Meg
3766 * in the block range (that is rather arbitrary, should
3767 * probably be time based) or when the data about to be
3768 * copied would over-write the source of the data at
3769 * the front of the range.
fef9c61f
N		 3770 * i.e. one new_stripe along from reshape_progress new_maps
3771 * to after where reshape_safe old_maps to
52c03291 3772 */
fef9c61f 3773 writepos = conf->reshape_progress;
f416885e 3774 sector_div(writepos, new_data_disks);
c8f517c4
N		 3775 readpos = conf->reshape_progress;
3776 sector_div(readpos, data_disks);
fef9c61f 3777 safepos = conf->reshape_safe;
f416885e 3778 sector_div(safepos, data_disks);
fef9c61f 3779 if (mddev->delta_disks < 0) {
ed37d83e 3780 writepos -= min_t(sector_t, reshape_sectors, writepos);
c8f517c4 3781 readpos += reshape_sectors;
7a661381 3782 safepos += reshape_sectors;
fef9c61f 3783 } else {
7a661381 3784 writepos += reshape_sectors;
ed37d83e
N		 3785 readpos -= min_t(sector_t, reshape_sectors, readpos);
3786 safepos -= min_t(sector_t, reshape_sectors, safepos);
fef9c61f 3787 }
52c03291 3788
c8f517c4
N		 3789 /* 'writepos' is the most advanced device address we might write.
3790 * 'readpos' is the least advanced device address we might read.
3791 * 'safepos' is the least address recorded in the metadata as having
3792 * been reshaped.
3793 * If 'readpos' is behind 'writepos', then there is no way that we can
3794 * ensure safety in the face of a crash - that must be done by userspace
3795 * making a backup of the data. So in that case there is no particular
3796 * rush to update metadata.
3797 * Otherwise if 'safepos' is behind 'writepos', then we really need to
3798 * update the metadata to advance 'safepos' to match 'readpos' so that
3799 * we can be safe in the event of a crash.
3800 * So we insist on updating metadata if safepos is behind writepos and
3801 * readpos is beyond writepos.
3802 * In any case, update the metadata every 10 seconds.
3803 * Maybe that number should be configurable, but I'm not sure it is
3804 * worth it.... maybe it could be a multiple of safemode_delay???
3805 */
fef9c61f 3806 if ((mddev->delta_disks < 0
c8f517c4
N		 3807 ? (safepos > writepos && readpos < writepos)
3808 : (safepos < writepos && readpos > writepos)) ||
3809 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
52c03291
N		 3810 /* Cannot proceed until we've updated the superblock... */
3811 wait_event(conf->wait_for_overlap,
3812 atomic_read(&conf->reshape_stripes)==0);
fef9c61f 3813 mddev->reshape_position = conf->reshape_progress;
75d3da43 3814 mddev->curr_resync_completed = sector_nr;
c8f517c4 3815 conf->reshape_checkpoint = jiffies;
850b2b42 3816 set_bit(MD_CHANGE_DEVS, &mddev->flags);
52c03291 3817 md_wakeup_thread(mddev->thread);
850b2b42 3818 wait_event(mddev->sb_wait, mddev->flags == 0 ||
52c03291
N		 3819 kthread_should_stop());
3820 spin_lock_irq(&conf->device_lock);
fef9c61f 3821 conf->reshape_safe = mddev->reshape_position;
52c03291
N		 3822 spin_unlock_irq(&conf->device_lock);
3823 wake_up(&conf->wait_for_overlap);
acb180b0 3824 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
52c03291
N		 3825 }
3826
ec32a2bd
N		 3827 if (mddev->delta_disks < 0) {
3828 BUG_ON(conf->reshape_progress == 0);
3829 stripe_addr = writepos;
3830 BUG_ON((mddev->dev_sectors &
7a661381
N		 3831 ~((sector_t)reshape_sectors - 1))
3832 - reshape_sectors - stripe_addr
ec32a2bd
N		 3833 != sector_nr);
3834 } else {
7a661381 3835 BUG_ON(writepos != sector_nr + reshape_sectors);
ec32a2bd
N		 3836 stripe_addr = sector_nr;
3837 }
ab69ae12 3838 INIT_LIST_HEAD(&stripes);
7a661381 3839 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
52c03291 3840 int j;
a9f326eb 3841 int skipped_disk = 0;
a8c906ca 3842 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
52c03291
N		 3843 set_bit(STRIPE_EXPANDING, &sh->state);
3844 atomic_inc(&conf->reshape_stripes);
3845 /* If any of this stripe is beyond the end of the old
3846 * array, then we need to zero those blocks
3847 */
3848 for (j=sh->disks; j--;) {
3849 sector_t s;
3850 if (j == sh->pd_idx)
3851 continue;
f416885e 3852 if (conf->level == 6 &&
d0dabf7e 3853 j == sh->qd_idx)
f416885e 3854 continue;
784052ec 3855 s = compute_blocknr(sh, j, 0);
b522adcd 3856 if (s < raid5_size(mddev, 0, 0)) {
a9f326eb 3857 skipped_disk = 1;
52c03291
N		 3858 continue;
3859 }
3860 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3861 set_bit(R5_Expanded, &sh->dev[j].flags);
3862 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3863 }
a9f326eb 3864 if (!skipped_disk) {
52c03291
N		 3865 set_bit(STRIPE_EXPAND_READY, &sh->state);
3866 set_bit(STRIPE_HANDLE, &sh->state);
3867 }
ab69ae12 3868 list_add(&sh->lru, &stripes);
52c03291
N		 3869 }
3870 spin_lock_irq(&conf->device_lock);
fef9c61f 3871 if (mddev->delta_disks < 0)
7a661381 3872 conf->reshape_progress -= reshape_sectors * new_data_disks;
fef9c61f 3873 else
7a661381 3874 conf->reshape_progress += reshape_sectors * new_data_disks;
52c03291
N		 3875 spin_unlock_irq(&conf->device_lock);
3876 /* Ok, those stripe are ready. We can start scheduling
3877 * reads on the source stripes.
3878 * The source stripes are determined by mapping the first and last
3879 * block on the destination stripes.
3880 */
52c03291 3881 first_sector =
ec32a2bd 3882 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
911d4ee8 3883 1, &dd_idx, NULL);
52c03291 3884 last_sector =
0e6e0271 3885 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
09c9e5fa 3886 * new_data_disks - 1),
911d4ee8 3887 1, &dd_idx, NULL);
58c0fed4
AN		 3888 if (last_sector >= mddev->dev_sectors)
3889 last_sector = mddev->dev_sectors - 1;
52c03291 3890 while (first_sector <= last_sector) {
a8c906ca 3891 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
52c03291
N		 3892 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3893 set_bit(STRIPE_HANDLE, &sh->state);
3894 release_stripe(sh);
3895 first_sector += STRIPE_SECTORS;
3896 }
ab69ae12
N		 3897 /* Now that the sources are clearly marked, we can release
3898 * the destination stripes
3899 */
3900 while (!list_empty(&stripes)) {
3901 sh = list_entry(stripes.next, struct stripe_head, lru);
3902 list_del_init(&sh->lru);
3903 release_stripe(sh);
3904 }
c6207277
N		 3905 /* If this takes us to the resync_max point where we have to pause,
3906 * then we need to write out the superblock.
3907 */
7a661381 3908 sector_nr += reshape_sectors;
c03f6a19
N		 3909 if ((sector_nr - mddev->curr_resync_completed) * 2
3910 >= mddev->resync_max - mddev->curr_resync_completed) {
c6207277
N		 3911 /* Cannot proceed until we've updated the superblock... */
3912 wait_event(conf->wait_for_overlap,
3913 atomic_read(&conf->reshape_stripes) == 0);
fef9c61f 3914 mddev->reshape_position = conf->reshape_progress;
75d3da43 3915 mddev->curr_resync_completed = sector_nr;
c8f517c4 3916 conf->reshape_checkpoint = jiffies;
c6207277
N		 3917 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3918 md_wakeup_thread(mddev->thread);
3919 wait_event(mddev->sb_wait,
3920 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3921 || kthread_should_stop());
3922 spin_lock_irq(&conf->device_lock);
fef9c61f 3923 conf->reshape_safe = mddev->reshape_position;
c6207277
N		 3924 spin_unlock_irq(&conf->device_lock);
3925 wake_up(&conf->wait_for_overlap);
acb180b0 3926 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
c6207277 3927 }
7a661381 3928 return reshape_sectors;
52c03291
N		 3929}
3930
3931/* FIXME go_faster isn't used */
3932static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3933{
7b92813c 3934 raid5_conf_t *conf = mddev->private;
52c03291 3935 struct stripe_head *sh;
58c0fed4 3936 sector_t max_sector = mddev->dev_sectors;
57dab0bd 3937 sector_t sync_blocks;
16a53ecc
N		 3938 int still_degraded = 0;
3939 int i;
1da177e4 3940
72626685 3941 if (sector_nr >= max_sector) {
1da177e4 3942 /* just being told to finish up .. nothing much to do */
cea9c228 3943
29269553
N		 3944 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3945 end_reshape(conf);
3946 return 0;
3947 }
72626685
N		 3948
3949 if (mddev->curr_resync < max_sector) /* aborted */
3950 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3951 &sync_blocks, 1);
16a53ecc 3952 else /* completed sync */
72626685
N		 3953 conf->fullsync = 0;
3954 bitmap_close_sync(mddev->bitmap);
3955
1da177e4
LT		 3956 return 0;
3957 }
ccfcc3c1 3958
64bd660b
N		 3959 /* Allow raid5_quiesce to complete */
3960 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
3961
52c03291
N		 3962 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3963 return reshape_request(mddev, sector_nr, skipped);
f6705578 3964
c6207277
N		 3965 /* No need to check resync_max as we never do more than one
3966 * stripe, and as resync_max will always be on a chunk boundary,
3967 * if the check in md_do_sync didn't fire, there is no chance
3968 * of overstepping resync_max here
3969 */
3970
16a53ecc 3971 /* if there is too many failed drives and we are trying
1da177e4
LT		 3972 * to resync, then assert that we are finished, because there is
3973 * nothing we can do.
3974 */
3285edf1 3975 if (mddev->degraded >= conf->max_degraded &&
16a53ecc 3976 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
58c0fed4 3977 sector_t rv = mddev->dev_sectors - sector_nr;
57afd89f 3978 *skipped = 1;
1da177e4
LT		 3979 return rv;
3980 }
72626685 3981 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
3855ad9f 3982 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
72626685
N		 3983 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3984 /* we can skip this block, and probably more */
3985 sync_blocks /= STRIPE_SECTORS;
3986 *skipped = 1;
3987 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3988 }
1da177e4 3989
b47490c9
N		 3990
3991 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
3992
a8c906ca 3993 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
1da177e4 3994 if (sh == NULL) {
a8c906ca 3995 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
1da177e4 3996 /* make sure we don't swamp the stripe cache if someone else
16a53ecc 3997 * is trying to get access
1da177e4 3998 */
66c006a5 3999 schedule_timeout_uninterruptible(1);
1da177e4 4000 }
16a53ecc
N		 4001 /* Need to check if array will still be degraded after recovery/resync
4002 * We don't need to check the 'failed' flag as when that gets set,
4003 * recovery aborts.
4004 */
f001a70c 4005 for (i = 0; i < conf->raid_disks; i++)
16a53ecc
N		 4006 if (conf->disks[i].rdev == NULL)
4007 still_degraded = 1;
4008
4009 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4010
83206d66 4011 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
1da177e4 4012
1442577b 4013 handle_stripe(sh);
1da177e4
LT		 4014 release_stripe(sh);
4015
4016 return STRIPE_SECTORS;
4017}
4018
46031f9a
RBJ		 4019static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4020{
4021 /* We may not be able to submit a whole bio at once as there
4022 * may not be enough stripe_heads available.
4023 * We cannot pre-allocate enough stripe_heads as we may need
4024 * more than exist in the cache (if we allow ever large chunks).
4025 * So we do one stripe head at a time and record in
4026 * ->bi_hw_segments how many have been done.
4027 *
4028 * We *know* that this entire raid_bio is in one chunk, so
4029 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4030 */
4031 struct stripe_head *sh;
911d4ee8 4032 int dd_idx;
46031f9a
RBJ		 4033 sector_t sector, logical_sector, last_sector;
4034 int scnt = 0;
4035 int remaining;
4036 int handled = 0;
4037
4038 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
112bf897 4039 sector = raid5_compute_sector(conf, logical_sector,
911d4ee8 4040 0, &dd_idx, NULL);
46031f9a
RBJ		 4041 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4042
4043 for (; logical_sector < last_sector;
387bb173
NB		 4044 logical_sector += STRIPE_SECTORS,
4045 sector += STRIPE_SECTORS,
4046 scnt++) {
46031f9a 4047
960e739d 4048 if (scnt < raid5_bi_hw_segments(raid_bio))
46031f9a
RBJ		 4049 /* already done this stripe */
4050 continue;
4051
a8c906ca 4052 sh = get_active_stripe(conf, sector, 0, 1, 0);
46031f9a
RBJ		 4053
4054 if (!sh) {
4055 /* failed to get a stripe - must wait */
960e739d 4056 raid5_set_bi_hw_segments(raid_bio, scnt);
46031f9a
RBJ		 4057 conf->retry_read_aligned = raid_bio;
4058 return handled;
4059 }
4060
4061 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
387bb173
NB		 4062 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4063 release_stripe(sh);
960e739d 4064 raid5_set_bi_hw_segments(raid_bio, scnt);
387bb173
NB		 4065 conf->retry_read_aligned = raid_bio;
4066 return handled;
4067 }
4068
36d1c647 4069 handle_stripe(sh);
46031f9a
RBJ		 4070 release_stripe(sh);
4071 handled++;
4072 }
4073 spin_lock_irq(&conf->device_lock);
960e739d 4074 remaining = raid5_dec_bi_phys_segments(raid_bio);
46031f9a 4075 spin_unlock_irq(&conf->device_lock);
0e13fe23
NB		 4076 if (remaining == 0)
4077 bio_endio(raid_bio, 0);
46031f9a
RBJ		 4078 if (atomic_dec_and_test(&conf->active_aligned_reads))
4079 wake_up(&conf->wait_for_stripe);
4080 return handled;
4081}
4082
46031f9a 4083
1da177e4
LT		 4084/*
4085 * This is our raid5 kernel thread.
4086 *
4087 * We scan the hash table for stripes which can be handled now.
4088 * During the scan, completed stripes are saved for us by the interrupt
4089 * handler, so that they will not have to wait for our next wakeup.
4090 */
6ed3003c 4091static void raid5d(mddev_t *mddev)
1da177e4
LT		 4092{
4093 struct stripe_head *sh;
070ec55d 4094 raid5_conf_t *conf = mddev->private;
1da177e4 4095 int handled;
e1dfa0a2 4096 struct blk_plug plug;
1da177e4 4097
45b4233c 4098 pr_debug("+++ raid5d active\n");
1da177e4
LT		 4099
4100 md_check_recovery(mddev);
1da177e4 4101
e1dfa0a2 4102 blk_start_plug(&plug);
1da177e4
LT		 4103 handled = 0;
4104 spin_lock_irq(&conf->device_lock);
4105 while (1) {
46031f9a 4106 struct bio *bio;
1da177e4 4107
7c13edc8
N		 4108 if (atomic_read(&mddev->plug_cnt) == 0 &&
4109 !list_empty(&conf->bitmap_list)) {
4110 /* Now is a good time to flush some bitmap updates */
4111 conf->seq_flush++;
700e432d 4112 spin_unlock_irq(&conf->device_lock);
72626685 4113 bitmap_unplug(mddev->bitmap);
700e432d 4114 spin_lock_irq(&conf->device_lock);
7c13edc8 4115 conf->seq_write = conf->seq_flush;
72626685
N		 4116 activate_bit_delay(conf);
4117 }
7c13edc8
N		 4118 if (atomic_read(&mddev->plug_cnt) == 0)
4119 raid5_activate_delayed(conf);
72626685 4120
46031f9a
RBJ		 4121 while ((bio = remove_bio_from_retry(conf))) {
4122 int ok;
4123 spin_unlock_irq(&conf->device_lock);
4124 ok = retry_aligned_read(conf, bio);
4125 spin_lock_irq(&conf->device_lock);
4126 if (!ok)
4127 break;
4128 handled++;
4129 }
4130
8b3e6cdc
DW		 4131 sh = __get_priority_stripe(conf);
4132
c9f21aaf 4133 if (!sh)
1da177e4 4134 break;
1da177e4
LT		 4135 spin_unlock_irq(&conf->device_lock);
4136
4137 handled++;
417b8d4a
DW		 4138 handle_stripe(sh);
4139 release_stripe(sh);
4140 cond_resched();
1da177e4
LT		 4141
4142 spin_lock_irq(&conf->device_lock);
4143 }
45b4233c 4144 pr_debug("%d stripes handled\n", handled);
1da177e4
LT		 4145
4146 spin_unlock_irq(&conf->device_lock);
4147
c9f21aaf 4148 async_tx_issue_pending_all();
e1dfa0a2 4149 blk_finish_plug(&plug);
1da177e4 4150
45b4233c 4151 pr_debug("--- raid5d inactive\n");
1da177e4
LT		 4152}
4153
3f294f4f 4154static ssize_t
007583c9 4155raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
3f294f4f 4156{
070ec55d 4157 raid5_conf_t *conf = mddev->private;
96de1e66
N		 4158 if (conf)
4159 return sprintf(page, "%d\n", conf->max_nr_stripes);
4160 else
4161 return 0;
3f294f4f
N		 4162}
4163
c41d4ac4
N		 4164int
4165raid5_set_cache_size(mddev_t *mddev, int size)
3f294f4f 4166{
070ec55d 4167 raid5_conf_t *conf = mddev->private;
b5470dc5
DW		 4168 int err;
4169
c41d4ac4 4170 if (size <= 16 || size > 32768)
3f294f4f 4171 return -EINVAL;
c41d4ac4 4172 while (size < conf->max_nr_stripes) {
3f294f4f
N		 4173 if (drop_one_stripe(conf))
4174 conf->max_nr_stripes--;
4175 else
4176 break;
4177 }
b5470dc5
DW		 4178 err = md_allow_write(mddev);
4179 if (err)
4180 return err;
c41d4ac4 4181 while (size > conf->max_nr_stripes) {
3f294f4f
N		 4182 if (grow_one_stripe(conf))
4183 conf->max_nr_stripes++;
4184 else break;
4185 }
c41d4ac4
N		 4186 return 0;
4187}
4188EXPORT_SYMBOL(raid5_set_cache_size);
4189
4190static ssize_t
4191raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
4192{
4193 raid5_conf_t *conf = mddev->private;
4194 unsigned long new;
4195 int err;
4196
4197 if (len >= PAGE_SIZE)
4198 return -EINVAL;
4199 if (!conf)
4200 return -ENODEV;
4201
4202 if (strict_strtoul(page, 10, &new))
4203 return -EINVAL;
4204 err = raid5_set_cache_size(mddev, new);
4205 if (err)
4206 return err;
3f294f4f
N		 4207 return len;
4208}
007583c9 4209
96de1e66
N		 4210static struct md_sysfs_entry
4211raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4212 raid5_show_stripe_cache_size,
4213 raid5_store_stripe_cache_size);
3f294f4f 4214
8b3e6cdc
DW		 4215static ssize_t
4216raid5_show_preread_threshold(mddev_t *mddev, char *page)
4217{
070ec55d 4218 raid5_conf_t *conf = mddev->private;
8b3e6cdc
DW		 4219 if (conf)
4220 return sprintf(page, "%d\n", conf->bypass_threshold);
4221 else
4222 return 0;
4223}
4224
4225static ssize_t
4226raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4227{
070ec55d 4228 raid5_conf_t *conf = mddev->private;
4ef197d8 4229 unsigned long new;
8b3e6cdc
DW		 4230 if (len >= PAGE_SIZE)
4231 return -EINVAL;
4232 if (!conf)
4233 return -ENODEV;
4234
4ef197d8 4235 if (strict_strtoul(page, 10, &new))
8b3e6cdc 4236 return -EINVAL;
4ef197d8 4237 if (new > conf->max_nr_stripes)
8b3e6cdc
DW		 4238 return -EINVAL;
4239 conf->bypass_threshold = new;
4240 return len;
4241}
4242
4243static struct md_sysfs_entry
4244raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4245 S_IRUGO | S_IWUSR,
4246 raid5_show_preread_threshold,
4247 raid5_store_preread_threshold);
4248
3f294f4f 4249static ssize_t
96de1e66 4250stripe_cache_active_show(mddev_t *mddev, char *page)
3f294f4f 4251{
070ec55d 4252 raid5_conf_t *conf = mddev->private;
96de1e66
N		 4253 if (conf)
4254 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4255 else
4256 return 0;
3f294f4f
N		 4257}
4258
96de1e66
N		 4259static struct md_sysfs_entry
4260raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
3f294f4f 4261
007583c9 4262static struct attribute *raid5_attrs[] = {
3f294f4f
N		 4263 &raid5_stripecache_size.attr,
4264 &raid5_stripecache_active.attr,
8b3e6cdc 4265 &raid5_preread_bypass_threshold.attr,
3f294f4f
N		 4266 NULL,
4267};
007583c9
N		 4268static struct attribute_group raid5_attrs_group = {
4269 .name = NULL,
4270 .attrs = raid5_attrs,
3f294f4f
N		 4271};
4272
80c3a6ce
DW		 4273static sector_t
4274raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4275{
070ec55d 4276 raid5_conf_t *conf = mddev->private;
80c3a6ce
DW		 4277
4278 if (!sectors)
4279 sectors = mddev->dev_sectors;
5e5e3e78 4280 if (!raid_disks)
7ec05478 4281 /* size is defined by the smallest of previous and new size */
5e5e3e78 4282 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
80c3a6ce 4283
9d8f0363 4284 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
664e7c41 4285 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
80c3a6ce
DW		 4286 return sectors * (raid_disks - conf->max_degraded);
4287}
4288
36d1c647
DW		 4289static void raid5_free_percpu(raid5_conf_t *conf)
4290{
4291 struct raid5_percpu *percpu;
4292 unsigned long cpu;
4293
4294 if (!conf->percpu)
4295 return;
4296
4297 get_online_cpus();
4298 for_each_possible_cpu(cpu) {
4299 percpu = per_cpu_ptr(conf->percpu, cpu);
4300 safe_put_page(percpu->spare_page);
d6f38f31 4301 kfree(percpu->scribble);
36d1c647
DW		 4302 }
4303#ifdef CONFIG_HOTPLUG_CPU
4304 unregister_cpu_notifier(&conf->cpu_notify);
4305#endif
4306 put_online_cpus();
4307
4308 free_percpu(conf->percpu);
4309}
4310
95fc17aa
DW		 4311static void free_conf(raid5_conf_t *conf)
4312{
4313 shrink_stripes(conf);
36d1c647 4314 raid5_free_percpu(conf);
95fc17aa
DW		 4315 kfree(conf->disks);
4316 kfree(conf->stripe_hashtbl);
4317 kfree(conf);
4318}
4319
36d1c647
DW		 4320#ifdef CONFIG_HOTPLUG_CPU
4321static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
4322 void *hcpu)
4323{
4324 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify);
4325 long cpu = (long)hcpu;
4326 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
4327
4328 switch (action) {
4329 case CPU_UP_PREPARE:
4330 case CPU_UP_PREPARE_FROZEN:
d6f38f31 4331 if (conf->level == 6 && !percpu->spare_page)
36d1c647 4332 percpu->spare_page = alloc_page(GFP_KERNEL);
d6f38f31
DW		 4333 if (!percpu->scribble)
4334 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4335
4336 if (!percpu->scribble ||
4337 (conf->level == 6 && !percpu->spare_page)) {
4338 safe_put_page(percpu->spare_page);
4339 kfree(percpu->scribble);
36d1c647
DW		 4340 pr_err("%s: failed memory allocation for cpu%ld\n",
4341 __func__, cpu);
55af6bb5 4342 return notifier_from_errno(-ENOMEM);
36d1c647
DW		 4343 }
4344 break;
4345 case CPU_DEAD:
4346 case CPU_DEAD_FROZEN:
4347 safe_put_page(percpu->spare_page);
d6f38f31 4348 kfree(percpu->scribble);
36d1c647 4349 percpu->spare_page = NULL;
d6f38f31 4350 percpu->scribble = NULL;
36d1c647
DW		 4351 break;
4352 default:
4353 break;
4354 }
4355 return NOTIFY_OK;
4356}
4357#endif
4358
4359static int raid5_alloc_percpu(raid5_conf_t *conf)
4360{
4361 unsigned long cpu;
4362 struct page *spare_page;
a29d8b8e 4363 struct raid5_percpu __percpu *allcpus;
d6f38f31 4364 void *scribble;
36d1c647
DW		 4365 int err;
4366
36d1c647
DW		 4367 allcpus = alloc_percpu(struct raid5_percpu);
4368 if (!allcpus)
4369 return -ENOMEM;
4370 conf->percpu = allcpus;
4371
4372 get_online_cpus();
4373 err = 0;
4374 for_each_present_cpu(cpu) {
d6f38f31
DW		 4375 if (conf->level == 6) {
4376 spare_page = alloc_page(GFP_KERNEL);
4377 if (!spare_page) {
4378 err = -ENOMEM;
4379 break;
4380 }
4381 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
4382 }
5e5e3e78 4383 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
d6f38f31 4384 if (!scribble) {
36d1c647
DW		 4385 err = -ENOMEM;
4386 break;
4387 }
d6f38f31 4388 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
36d1c647
DW		 4389 }
4390#ifdef CONFIG_HOTPLUG_CPU
4391 conf->cpu_notify.notifier_call = raid456_cpu_notify;
4392 conf->cpu_notify.priority = 0;
4393 if (err == 0)
4394 err = register_cpu_notifier(&conf->cpu_notify);
4395#endif
4396 put_online_cpus();
4397
4398 return err;
4399}
4400
91adb564 4401static raid5_conf_t *setup_conf(mddev_t *mddev)
1da177e4
LT		 4402{
4403 raid5_conf_t *conf;
5e5e3e78 4404 int raid_disk, memory, max_disks;
1da177e4
LT		 4405 mdk_rdev_t *rdev;
4406 struct disk_info *disk;
1da177e4 4407
91adb564
N		 4408 if (mddev->new_level != 5
4409 && mddev->new_level != 4
4410 && mddev->new_level != 6) {
0c55e022 4411 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
91adb564
N		 4412 mdname(mddev), mddev->new_level);
4413 return ERR_PTR(-EIO);
1da177e4 4414 }
91adb564
N		 4415 if ((mddev->new_level == 5
4416 && !algorithm_valid_raid5(mddev->new_layout)) ||
4417 (mddev->new_level == 6
4418 && !algorithm_valid_raid6(mddev->new_layout))) {
0c55e022 4419 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
91adb564
N		 4420 mdname(mddev), mddev->new_layout);
4421 return ERR_PTR(-EIO);
99c0fb5f 4422 }
91adb564 4423 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
0c55e022 4424 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
91adb564
N		 4425 mdname(mddev), mddev->raid_disks);
4426 return ERR_PTR(-EINVAL);
4bbf3771
N		 4427 }
4428
664e7c41
AN		 4429 if (!mddev->new_chunk_sectors ||
4430 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4431 !is_power_of_2(mddev->new_chunk_sectors)) {
0c55e022
N		 4432 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
4433 mdname(mddev), mddev->new_chunk_sectors << 9);
91adb564 4434 return ERR_PTR(-EINVAL);
f6705578
N		 4435 }
4436
91adb564
N		 4437 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4438 if (conf == NULL)
1da177e4 4439 goto abort;
f5efd45a
DW		 4440 spin_lock_init(&conf->device_lock);
4441 init_waitqueue_head(&conf->wait_for_stripe);
4442 init_waitqueue_head(&conf->wait_for_overlap);
4443 INIT_LIST_HEAD(&conf->handle_list);
4444 INIT_LIST_HEAD(&conf->hold_list);
4445 INIT_LIST_HEAD(&conf->delayed_list);
4446 INIT_LIST_HEAD(&conf->bitmap_list);
4447 INIT_LIST_HEAD(&conf->inactive_list);
4448 atomic_set(&conf->active_stripes, 0);
4449 atomic_set(&conf->preread_active_stripes, 0);
4450 atomic_set(&conf->active_aligned_reads, 0);
4451 conf->bypass_threshold = BYPASS_THRESHOLD;
91adb564
N		 4452
4453 conf->raid_disks = mddev->raid_disks;
4454 if (mddev->reshape_position == MaxSector)
4455 conf->previous_raid_disks = mddev->raid_disks;
4456 else
f6705578 4457 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
5e5e3e78
N		 4458 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
4459 conf->scribble_len = scribble_len(max_disks);
f6705578 4460
5e5e3e78 4461 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
b55e6bfc
N		 4462 GFP_KERNEL);
4463 if (!conf->disks)
4464 goto abort;
9ffae0cf 4465
1da177e4
LT		 4466 conf->mddev = mddev;
4467
fccddba0 4468 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
1da177e4 4469 goto abort;
1da177e4 4470
36d1c647
DW		 4471 conf->level = mddev->new_level;
4472 if (raid5_alloc_percpu(conf) != 0)
4473 goto abort;
4474
0c55e022 4475 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
1da177e4 4476
159ec1fc 4477 list_for_each_entry(rdev, &mddev->disks, same_set) {
1da177e4 4478 raid_disk = rdev->raid_disk;
5e5e3e78 4479 if (raid_disk >= max_disks
1da177e4
LT		 4480 || raid_disk < 0)
4481 continue;
4482 disk = conf->disks + raid_disk;
4483
4484 disk->rdev = rdev;
4485
b2d444d7 4486 if (test_bit(In_sync, &rdev->flags)) {
1da177e4 4487 char b[BDEVNAME_SIZE];
0c55e022
N		 4488 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
4489 " disk %d\n",
4490 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
d6b212f4 4491 } else if (rdev->saved_raid_disk != raid_disk)
8c2e870a
NB		 4492 /* Cannot rely on bitmap to complete recovery */
4493 conf->fullsync = 1;
1da177e4
LT		 4494 }
4495
09c9e5fa 4496 conf->chunk_sectors = mddev->new_chunk_sectors;
91adb564 4497 conf->level = mddev->new_level;
16a53ecc
N		 4498 if (conf->level == 6)
4499 conf->max_degraded = 2;
4500 else
4501 conf->max_degraded = 1;
91adb564 4502 conf->algorithm = mddev->new_layout;
1da177e4 4503 conf->max_nr_stripes = NR_STRIPES;
fef9c61f 4504 conf->reshape_progress = mddev->reshape_position;
e183eaed 4505 if (conf->reshape_progress != MaxSector) {
09c9e5fa 4506 conf->prev_chunk_sectors = mddev->chunk_sectors;
e183eaed
N		 4507 conf->prev_algo = mddev->layout;
4508 }
1da177e4 4509
91adb564 4510 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
5e5e3e78 4511 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
91adb564
N		 4512 if (grow_stripes(conf, conf->max_nr_stripes)) {
4513 printk(KERN_ERR
0c55e022
N		 4514 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4515 mdname(mddev), memory);
91adb564
N		 4516 goto abort;
4517 } else
0c55e022
N		 4518 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
4519 mdname(mddev), memory);
1da177e4 4520
0da3c619 4521 conf->thread = md_register_thread(raid5d, mddev, NULL);
91adb564
N		 4522 if (!conf->thread) {
4523 printk(KERN_ERR
0c55e022 4524 "md/raid:%s: couldn't allocate thread.\n",
91adb564 4525 mdname(mddev));
16a53ecc
N		 4526 goto abort;
4527 }
91adb564
N		 4528
4529 return conf;
4530
4531 abort:
4532 if (conf) {
95fc17aa 4533 free_conf(conf);
91adb564
N		 4534 return ERR_PTR(-EIO);
4535 } else
4536 return ERR_PTR(-ENOMEM);
4537}
4538
c148ffdc
N		 4539
4540static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
4541{
4542 switch (algo) {
4543 case ALGORITHM_PARITY_0:
4544 if (raid_disk < max_degraded)
4545 return 1;
4546 break;
4547 case ALGORITHM_PARITY_N:
4548 if (raid_disk >= raid_disks - max_degraded)
4549 return 1;
4550 break;
4551 case ALGORITHM_PARITY_0_6:
4552 if (raid_disk == 0 ||
4553 raid_disk == raid_disks - 1)
4554 return 1;
4555 break;
4556 case ALGORITHM_LEFT_ASYMMETRIC_6:
4557 case ALGORITHM_RIGHT_ASYMMETRIC_6:
4558 case ALGORITHM_LEFT_SYMMETRIC_6:
4559 case ALGORITHM_RIGHT_SYMMETRIC_6:
4560 if (raid_disk == raid_disks - 1)
4561 return 1;
4562 }
4563 return 0;
4564}
4565
91adb564
N		 4566static int run(mddev_t *mddev)
4567{
4568 raid5_conf_t *conf;
9f7c2220 4569 int working_disks = 0;
c148ffdc 4570 int dirty_parity_disks = 0;
91adb564 4571 mdk_rdev_t *rdev;
c148ffdc 4572 sector_t reshape_offset = 0;
91adb564 4573
8c6ac868 4574 if (mddev->recovery_cp != MaxSector)
0c55e022 4575 printk(KERN_NOTICE "md/raid:%s: not clean"
8c6ac868
AN		 4576 " -- starting background reconstruction\n",
4577 mdname(mddev));
91adb564
N		 4578 if (mddev->reshape_position != MaxSector) {
4579 /* Check that we can continue the reshape.
4580 * Currently only disks can change, it must
4581 * increase, and we must be past the point where
4582 * a stripe over-writes itself
4583 */
4584 sector_t here_new, here_old;
4585 int old_disks;
18b00334 4586 int max_degraded = (mddev->level == 6 ? 2 : 1);
91adb564 4587
88ce4930 4588 if (mddev->new_level != mddev->level) {
0c55e022 4589 printk(KERN_ERR "md/raid:%s: unsupported reshape "
91adb564
N		 4590 "required - aborting.\n",
4591 mdname(mddev));
4592 return -EINVAL;
4593 }
91adb564
N		 4594 old_disks = mddev->raid_disks - mddev->delta_disks;
4595 /* reshape_position must be on a new-stripe boundary, and one
4596 * further up in new geometry must map after here in old
4597 * geometry.
4598 */
4599 here_new = mddev->reshape_position;
664e7c41 4600 if (sector_div(here_new, mddev->new_chunk_sectors *
91adb564 4601 (mddev->raid_disks - max_degraded))) {
0c55e022
N		 4602 printk(KERN_ERR "md/raid:%s: reshape_position not "
4603 "on a stripe boundary\n", mdname(mddev));
91adb564
N		 4604 return -EINVAL;
4605 }
c148ffdc 4606 reshape_offset = here_new * mddev->new_chunk_sectors;
91adb564
N		 4607 /* here_new is the stripe we will write to */
4608 here_old = mddev->reshape_position;
9d8f0363 4609 sector_div(here_old, mddev->chunk_sectors *
91adb564
N		 4610 (old_disks-max_degraded));
4611 /* here_old is the first stripe that we might need to read
4612 * from */
67ac6011
N		 4613 if (mddev->delta_disks == 0) {
4614 /* We cannot be sure it is safe to start an in-place
4615 * reshape. It is only safe if user-space if monitoring
4616 * and taking constant backups.
4617 * mdadm always starts a situation like this in
4618 * readonly mode so it can take control before
4619 * allowing any writes. So just check for that.
4620 */
4621 if ((here_new * mddev->new_chunk_sectors !=
4622 here_old * mddev->chunk_sectors) ||
4623 mddev->ro == 0) {
0c55e022
N		 4624 printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
4625 " in read-only mode - aborting\n",
4626 mdname(mddev));
67ac6011
N		 4627 return -EINVAL;
4628 }
4629 } else if (mddev->delta_disks < 0
4630 ? (here_new * mddev->new_chunk_sectors <=
4631 here_old * mddev->chunk_sectors)
4632 : (here_new * mddev->new_chunk_sectors >=
4633 here_old * mddev->chunk_sectors)) {
91adb564 4634 /* Reading from the same stripe as writing to - bad */
0c55e022
N		 4635 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
4636 "auto-recovery - aborting.\n",
4637 mdname(mddev));
91adb564
N		 4638 return -EINVAL;
4639 }
0c55e022
N		 4640 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
4641 mdname(mddev));
91adb564
N		 4642 /* OK, we should be able to continue; */
4643 } else {
4644 BUG_ON(mddev->level != mddev->new_level);
4645 BUG_ON(mddev->layout != mddev->new_layout);
664e7c41 4646 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
91adb564 4647 BUG_ON(mddev->delta_disks != 0);
1da177e4 4648 }
91adb564 4649
245f46c2
N		 4650 if (mddev->private == NULL)
4651 conf = setup_conf(mddev);
4652 else
4653 conf = mddev->private;
4654
91adb564
N		 4655 if (IS_ERR(conf))
4656 return PTR_ERR(conf);
4657
4658 mddev->thread = conf->thread;
4659 conf->thread = NULL;
4660 mddev->private = conf;
4661
4662 /*
4663 * 0 for a fully functional array, 1 or 2 for a degraded array.
4664 */
c148ffdc
N		 4665 list_for_each_entry(rdev, &mddev->disks, same_set) {
4666 if (rdev->raid_disk < 0)
4667 continue;
2f115882 4668 if (test_bit(In_sync, &rdev->flags)) {
91adb564 4669 working_disks++;
2f115882
N		 4670 continue;
4671 }
c148ffdc
N		 4672 /* This disc is not fully in-sync. However if it
4673 * just stored parity (beyond the recovery_offset),
4674 * when we don't need to be concerned about the
4675 * array being dirty.
4676 * When reshape goes 'backwards', we never have
4677 * partially completed devices, so we only need
4678 * to worry about reshape going forwards.
4679 */
4680 /* Hack because v0.91 doesn't store recovery_offset properly. */
4681 if (mddev->major_version == 0 &&
4682 mddev->minor_version > 90)
4683 rdev->recovery_offset = reshape_offset;
4684
c148ffdc
N		 4685 if (rdev->recovery_offset < reshape_offset) {
4686 /* We need to check old and new layout */
4687 if (!only_parity(rdev->raid_disk,
4688 conf->algorithm,
4689 conf->raid_disks,
4690 conf->max_degraded))
4691 continue;
4692 }
4693 if (!only_parity(rdev->raid_disk,
4694 conf->prev_algo,
4695 conf->previous_raid_disks,
4696 conf->max_degraded))
4697 continue;
4698 dirty_parity_disks++;
4699 }
91adb564 4700
5e5e3e78
N		 4701 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
4702 - working_disks);
91adb564 4703
674806d6 4704 if (has_failed(conf)) {
0c55e022 4705 printk(KERN_ERR "md/raid:%s: not enough operational devices"
1da177e4 4706 " (%d/%d failed)\n",
02c2de8c 4707 mdname(mddev), mddev->degraded, conf->raid_disks);
1da177e4
LT		 4708 goto abort;
4709 }
4710
91adb564 4711 /* device size must be a multiple of chunk size */
9d8f0363 4712 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
91adb564
N		 4713 mddev->resync_max_sectors = mddev->dev_sectors;
4714
c148ffdc 4715 if (mddev->degraded > dirty_parity_disks &&
1da177e4 4716 mddev->recovery_cp != MaxSector) {
6ff8d8ec
N		 4717 if (mddev->ok_start_degraded)
4718 printk(KERN_WARNING
0c55e022
N		 4719 "md/raid:%s: starting dirty degraded array"
4720 " - data corruption possible.\n",
6ff8d8ec
N		 4721 mdname(mddev));
4722 else {
4723 printk(KERN_ERR
0c55e022 4724 "md/raid:%s: cannot start dirty degraded array.\n",
6ff8d8ec
N		 4725 mdname(mddev));
4726 goto abort;
4727 }
1da177e4
LT		 4728 }
4729
1da177e4 4730 if (mddev->degraded == 0)
0c55e022
N		 4731 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
4732 " devices, algorithm %d\n", mdname(mddev), conf->level,
e183eaed
N		 4733 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4734 mddev->new_layout);
1da177e4 4735 else
0c55e022
N		 4736 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
4737 " out of %d devices, algorithm %d\n",
4738 mdname(mddev), conf->level,
4739 mddev->raid_disks - mddev->degraded,
4740 mddev->raid_disks, mddev->new_layout);
1da177e4
LT		 4741
4742 print_raid5_conf(conf);
4743
fef9c61f 4744 if (conf->reshape_progress != MaxSector) {
fef9c61f 4745 conf->reshape_safe = conf->reshape_progress;
f6705578
N		 4746 atomic_set(&conf->reshape_stripes, 0);
4747 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4748 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4749 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4750 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4751 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 4752 "reshape");
f6705578
N		 4753 }
4754
1da177e4
LT		 4755
4756 /* Ok, everything is just fine now */
a64c876f
N		 4757 if (mddev->to_remove == &raid5_attrs_group)
4758 mddev->to_remove = NULL;
00bcb4ac
N		 4759 else if (mddev->kobj.sd &&
4760 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5e55e2f5 4761 printk(KERN_WARNING
4a5add49 4762 "raid5: failed to create sysfs attributes for %s\n",
5e55e2f5 4763 mdname(mddev));
4a5add49 4764 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7a5febe9 4765
4a5add49 4766 if (mddev->queue) {
9f7c2220 4767 int chunk_size;
4a5add49
N		 4768 /* read-ahead size must cover two whole stripes, which
4769 * is 2 * (datadisks) * chunksize where 'n' is the
4770 * number of raid devices
4771 */
4772 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4773 int stripe = data_disks *
4774 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
4775 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4776 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
91adb564 4777
4a5add49 4778 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
f022b2fd 4779
11d8a6e3
N		 4780 mddev->queue->backing_dev_info.congested_data = mddev;
4781 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
7a5febe9 4782
9f7c2220
N		 4783 chunk_size = mddev->chunk_sectors << 9;
4784 blk_queue_io_min(mddev->queue, chunk_size);
4785 blk_queue_io_opt(mddev->queue, chunk_size *
4786 (conf->raid_disks - conf->max_degraded));
8f6c2e4b 4787
9f7c2220
N		 4788 list_for_each_entry(rdev, &mddev->disks, same_set)
4789 disk_stack_limits(mddev->gendisk, rdev->bdev,
4790 rdev->data_offset << 9);
4791 }
23032a0e 4792
1da177e4
LT		 4793 return 0;
4794abort:
e0cf8f04 4795 md_unregister_thread(mddev->thread);
91adb564 4796 mddev->thread = NULL;
1da177e4
LT		 4797 if (conf) {
4798 print_raid5_conf(conf);
95fc17aa 4799 free_conf(conf);
1da177e4
LT		 4800 }
4801 mddev->private = NULL;
0c55e022 4802 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
1da177e4
LT		 4803 return -EIO;
4804}
4805
3f294f4f 4806static int stop(mddev_t *mddev)
1da177e4 4807{
7b92813c 4808 raid5_conf_t *conf = mddev->private;
1da177e4
LT		 4809
4810 md_unregister_thread(mddev->thread);
4811 mddev->thread = NULL;
11d8a6e3
N		 4812 if (mddev->queue)
4813 mddev->queue->backing_dev_info.congested_fn = NULL;
95fc17aa 4814 free_conf(conf);
a64c876f
N		 4815 mddev->private = NULL;
4816 mddev->to_remove = &raid5_attrs_group;
1da177e4
LT		 4817 return 0;
4818}
4819
45b4233c 4820#ifdef DEBUG
d710e138 4821static void print_sh(struct seq_file *seq, struct stripe_head *sh)
1da177e4
LT		 4822{
4823 int i;
4824
16a53ecc
N		 4825 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4826 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4827 seq_printf(seq, "sh %llu, count %d.\n",
4828 (unsigned long long)sh->sector, atomic_read(&sh->count));
4829 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
7ecaa1e6 4830 for (i = 0; i < sh->disks; i++) {
16a53ecc
N		 4831 seq_printf(seq, "(cache%d: %p %ld) ",
4832 i, sh->dev[i].page, sh->dev[i].flags);
1da177e4 4833 }
16a53ecc 4834 seq_printf(seq, "\n");
1da177e4
LT		 4835}
4836
d710e138 4837static void printall(struct seq_file *seq, raid5_conf_t *conf)
1da177e4
LT		 4838{
4839 struct stripe_head *sh;
fccddba0 4840 struct hlist_node *hn;
1da177e4
LT		 4841 int i;
4842
4843 spin_lock_irq(&conf->device_lock);
4844 for (i = 0; i < NR_HASH; i++) {
fccddba0 4845 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
1da177e4
LT		 4846 if (sh->raid_conf != conf)
4847 continue;
16a53ecc 4848 print_sh(seq, sh);
1da177e4
LT		 4849 }
4850 }
4851 spin_unlock_irq(&conf->device_lock);
4852}
4853#endif
4854
d710e138 4855static void status(struct seq_file *seq, mddev_t *mddev)
1da177e4 4856{
7b92813c 4857 raid5_conf_t *conf = mddev->private;
1da177e4
LT		 4858 int i;
4859
9d8f0363
AN		 4860 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
4861 mddev->chunk_sectors / 2, mddev->layout);
02c2de8c 4862 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
1da177e4
LT		 4863 for (i = 0; i < conf->raid_disks; i++)
4864 seq_printf (seq, "%s",
4865 conf->disks[i].rdev &&
b2d444d7 4866 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
1da177e4 4867 seq_printf (seq, "]");
45b4233c 4868#ifdef DEBUG
16a53ecc
N		 4869 seq_printf (seq, "\n");
4870 printall(seq, conf);
1da177e4
LT		 4871#endif
4872}
4873
4874static void print_raid5_conf (raid5_conf_t *conf)
4875{
4876 int i;
4877 struct disk_info *tmp;
4878
0c55e022 4879 printk(KERN_DEBUG "RAID conf printout:\n");
1da177e4
LT		 4880 if (!conf) {
4881 printk("(conf==NULL)\n");
4882 return;
4883 }
0c55e022
N		 4884 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
4885 conf->raid_disks,
4886 conf->raid_disks - conf->mddev->degraded);
1da177e4
LT		 4887
4888 for (i = 0; i < conf->raid_disks; i++) {
4889 char b[BDEVNAME_SIZE];
4890 tmp = conf->disks + i;
4891 if (tmp->rdev)
0c55e022
N		 4892 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
4893 i, !test_bit(Faulty, &tmp->rdev->flags),
4894 bdevname(tmp->rdev->bdev, b));
1da177e4
LT		 4895 }
4896}
4897
4898static int raid5_spare_active(mddev_t *mddev)
4899{
4900 int i;
4901 raid5_conf_t *conf = mddev->private;
4902 struct disk_info *tmp;
6b965620
N		 4903 int count = 0;
4904 unsigned long flags;
1da177e4
LT		 4905
4906 for (i = 0; i < conf->raid_disks; i++) {
4907 tmp = conf->disks + i;
4908 if (tmp->rdev
70fffd0b 4909 && tmp->rdev->recovery_offset == MaxSector
b2d444d7 4910 && !test_bit(Faulty, &tmp->rdev->flags)
c04be0aa 4911 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
6b965620 4912 count++;
43c73ca4 4913 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
1da177e4
LT		 4914 }
4915 }
6b965620
N		 4916 spin_lock_irqsave(&conf->device_lock, flags);
4917 mddev->degraded -= count;
4918 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4 4919 print_raid5_conf(conf);
6b965620 4920 return count;
1da177e4
LT		 4921}
4922
4923static int raid5_remove_disk(mddev_t *mddev, int number)
4924{
4925 raid5_conf_t *conf = mddev->private;
4926 int err = 0;
4927 mdk_rdev_t *rdev;
4928 struct disk_info *p = conf->disks + number;
4929
4930 print_raid5_conf(conf);
4931 rdev = p->rdev;
4932 if (rdev) {
ec32a2bd
N		 4933 if (number >= conf->raid_disks &&
4934 conf->reshape_progress == MaxSector)
4935 clear_bit(In_sync, &rdev->flags);
4936
b2d444d7 4937 if (test_bit(In_sync, &rdev->flags) ||
1da177e4
LT		 4938 atomic_read(&rdev->nr_pending)) {
4939 err = -EBUSY;
4940 goto abort;
4941 }
dfc70645
N		 4942 /* Only remove non-faulty devices if recovery
4943 * isn't possible.
4944 */
4945 if (!test_bit(Faulty, &rdev->flags) &&
674806d6 4946 !has_failed(conf) &&
ec32a2bd 4947 number < conf->raid_disks) {
dfc70645
N		 4948 err = -EBUSY;
4949 goto abort;
4950 }
1da177e4 4951 p->rdev = NULL;
fbd568a3 4952 synchronize_rcu();
1da177e4
LT		 4953 if (atomic_read(&rdev->nr_pending)) {
4954 /* lost the race, try later */
4955 err = -EBUSY;
4956 p->rdev = rdev;
4957 }
4958 }
4959abort:
4960
4961 print_raid5_conf(conf);
4962 return err;
4963}
4964
4965static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4966{
4967 raid5_conf_t *conf = mddev->private;
199050ea 4968 int err = -EEXIST;
1da177e4
LT		 4969 int disk;
4970 struct disk_info *p;
6c2fce2e
NB		 4971 int first = 0;
4972 int last = conf->raid_disks - 1;
1da177e4 4973
674806d6 4974 if (has_failed(conf))
1da177e4 4975 /* no point adding a device */
199050ea 4976 return -EINVAL;
1da177e4 4977
6c2fce2e
NB		 4978 if (rdev->raid_disk >= 0)
4979 first = last = rdev->raid_disk;
1da177e4
LT		 4980
4981 /*
16a53ecc
N		 4982 * find the disk ... but prefer rdev->saved_raid_disk
4983 * if possible.
1da177e4 4984 */
16a53ecc 4985 if (rdev->saved_raid_disk >= 0 &&
6c2fce2e 4986 rdev->saved_raid_disk >= first &&
16a53ecc
N		 4987 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4988 disk = rdev->saved_raid_disk;
4989 else
6c2fce2e
NB		 4990 disk = first;
4991 for ( ; disk <= last ; disk++)
1da177e4 4992 if ((p=conf->disks + disk)->rdev == NULL) {
b2d444d7 4993 clear_bit(In_sync, &rdev->flags);
1da177e4 4994 rdev->raid_disk = disk;
199050ea 4995 err = 0;
72626685
N		 4996 if (rdev->saved_raid_disk != disk)
4997 conf->fullsync = 1;
d6065f7b 4998 rcu_assign_pointer(p->rdev, rdev);
1da177e4
LT		 4999 break;
5000 }
5001 print_raid5_conf(conf);
199050ea 5002 return err;
1da177e4
LT		 5003}
5004
5005static int raid5_resize(mddev_t *mddev, sector_t sectors)
5006{
5007 /* no resync is happening, and there is enough space
5008 * on all devices, so we can resize.
5009 * We need to make sure resync covers any new space.
5010 * If the array is shrinking we should possibly wait until
5011 * any io in the removed space completes, but it hardly seems
5012 * worth it.
5013 */
9d8f0363 5014 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
1f403624
DW		 5015 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
5016 mddev->raid_disks));
b522adcd
DW		 5017 if (mddev->array_sectors >
5018 raid5_size(mddev, sectors, mddev->raid_disks))
5019 return -EINVAL;
f233ea5c 5020 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 5021 revalidate_disk(mddev->gendisk);
b098636c
N		 5022 if (sectors > mddev->dev_sectors &&
5023 mddev->recovery_cp > mddev->dev_sectors) {
58c0fed4 5024 mddev->recovery_cp = mddev->dev_sectors;
1da177e4
LT		 5025 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5026 }
58c0fed4 5027 mddev->dev_sectors = sectors;
4b5c7ae8 5028 mddev->resync_max_sectors = sectors;
1da177e4
LT		 5029 return 0;
5030}
5031
01ee22b4
N		 5032static int check_stripe_cache(mddev_t *mddev)
5033{
5034 /* Can only proceed if there are plenty of stripe_heads.
5035 * We need a minimum of one full stripe,, and for sensible progress
5036 * it is best to have about 4 times that.
5037 * If we require 4 times, then the default 256 4K stripe_heads will
5038 * allow for chunk sizes up to 256K, which is probably OK.
5039 * If the chunk size is greater, user-space should request more
5040 * stripe_heads first.
5041 */
5042 raid5_conf_t *conf = mddev->private;
5043 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5044 > conf->max_nr_stripes ||
5045 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5046 > conf->max_nr_stripes) {
0c55e022
N		 5047 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5048 mdname(mddev),
01ee22b4
N		 5049 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5050 / STRIPE_SIZE)*4);
5051 return 0;
5052 }
5053 return 1;
5054}
5055
50ac168a 5056static int check_reshape(mddev_t *mddev)
29269553 5057{
070ec55d 5058 raid5_conf_t *conf = mddev->private;
29269553 5059
88ce4930
N		 5060 if (mddev->delta_disks == 0 &&
5061 mddev->new_layout == mddev->layout &&
664e7c41 5062 mddev->new_chunk_sectors == mddev->chunk_sectors)
50ac168a 5063 return 0; /* nothing to do */
dba034ee
N		 5064 if (mddev->bitmap)
5065 /* Cannot grow a bitmap yet */
5066 return -EBUSY;
674806d6 5067 if (has_failed(conf))
ec32a2bd
N		 5068 return -EINVAL;
5069 if (mddev->delta_disks < 0) {
5070 /* We might be able to shrink, but the devices must
5071 * be made bigger first.
5072 * For raid6, 4 is the minimum size.
5073 * Otherwise 2 is the minimum
5074 */
5075 int min = 2;
5076 if (mddev->level == 6)
5077 min = 4;
5078 if (mddev->raid_disks + mddev->delta_disks < min)
5079 return -EINVAL;
5080 }
29269553 5081
01ee22b4 5082 if (!check_stripe_cache(mddev))
29269553 5083 return -ENOSPC;
29269553 5084
ec32a2bd 5085 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
63c70c4f
N		 5086}
5087
5088static int raid5_start_reshape(mddev_t *mddev)
5089{
070ec55d 5090 raid5_conf_t *conf = mddev->private;
63c70c4f 5091 mdk_rdev_t *rdev;
63c70c4f 5092 int spares = 0;
c04be0aa 5093 unsigned long flags;
63c70c4f 5094
f416885e 5095 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
63c70c4f
N		 5096 return -EBUSY;
5097
01ee22b4
N		 5098 if (!check_stripe_cache(mddev))
5099 return -ENOSPC;
5100
159ec1fc 5101 list_for_each_entry(rdev, &mddev->disks, same_set)
469518a3
N		 5102 if (!test_bit(In_sync, &rdev->flags)
5103 && !test_bit(Faulty, &rdev->flags))
29269553 5104 spares++;
63c70c4f 5105
f416885e 5106 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
29269553
N		 5107 /* Not enough devices even to make a degraded array
5108 * of that size
5109 */
5110 return -EINVAL;
5111
ec32a2bd
N		 5112 /* Refuse to reduce size of the array. Any reductions in
5113 * array size must be through explicit setting of array_size
5114 * attribute.
5115 */
5116 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5117 < mddev->array_sectors) {
0c55e022 5118 printk(KERN_ERR "md/raid:%s: array size must be reduced "
ec32a2bd
N		 5119 "before number of disks\n", mdname(mddev));
5120 return -EINVAL;
5121 }
5122
f6705578 5123 atomic_set(&conf->reshape_stripes, 0);
29269553
N		 5124 spin_lock_irq(&conf->device_lock);
5125 conf->previous_raid_disks = conf->raid_disks;
63c70c4f 5126 conf->raid_disks += mddev->delta_disks;
09c9e5fa
AN		 5127 conf->prev_chunk_sectors = conf->chunk_sectors;
5128 conf->chunk_sectors = mddev->new_chunk_sectors;
88ce4930
N		 5129 conf->prev_algo = conf->algorithm;
5130 conf->algorithm = mddev->new_layout;
fef9c61f
N		 5131 if (mddev->delta_disks < 0)
5132 conf->reshape_progress = raid5_size(mddev, 0, 0);
5133 else
5134 conf->reshape_progress = 0;
5135 conf->reshape_safe = conf->reshape_progress;
86b42c71 5136 conf->generation++;
29269553
N		 5137 spin_unlock_irq(&conf->device_lock);
5138
5139 /* Add some new drives, as many as will fit.
5140 * We know there are enough to make the newly sized array work.
3424bf6a
N		 5141 * Don't add devices if we are reducing the number of
5142 * devices in the array. This is because it is not possible
5143 * to correctly record the "partially reconstructed" state of
5144 * such devices during the reshape and confusion could result.
29269553 5145 */
87a8dec9
N		 5146 if (mddev->delta_disks >= 0) {
5147 int added_devices = 0;
5148 list_for_each_entry(rdev, &mddev->disks, same_set)
5149 if (rdev->raid_disk < 0 &&
5150 !test_bit(Faulty, &rdev->flags)) {
5151 if (raid5_add_disk(mddev, rdev) == 0) {
87a8dec9
N		 5152 if (rdev->raid_disk
5153 >= conf->previous_raid_disks) {
5154 set_bit(In_sync, &rdev->flags);
5155 added_devices++;
5156 } else
5157 rdev->recovery_offset = 0;
36fad858
NK		 5158
5159 if (sysfs_link_rdev(mddev, rdev))
87a8dec9 5160 /* Failure here is OK */;
50da0840 5161 }
87a8dec9
N		 5162 } else if (rdev->raid_disk >= conf->previous_raid_disks
5163 && !test_bit(Faulty, &rdev->flags)) {
5164 /* This is a spare that was manually added */
5165 set_bit(In_sync, &rdev->flags);
5166 added_devices++;
5167 }
29269553 5168
87a8dec9
N		 5169 /* When a reshape changes the number of devices,
5170 * ->degraded is measured against the larger of the
5171 * pre and post number of devices.
5172 */
ec32a2bd 5173 spin_lock_irqsave(&conf->device_lock, flags);
9eb07c25 5174 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
ec32a2bd
N		 5175 - added_devices;
5176 spin_unlock_irqrestore(&conf->device_lock, flags);
5177 }
63c70c4f 5178 mddev->raid_disks = conf->raid_disks;
e516402c 5179 mddev->reshape_position = conf->reshape_progress;
850b2b42 5180 set_bit(MD_CHANGE_DEVS, &mddev->flags);
f6705578 5181
29269553
N		 5182 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5183 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5184 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5185 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5186 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 5187 "reshape");
29269553
N		 5188 if (!mddev->sync_thread) {
5189 mddev->recovery = 0;
5190 spin_lock_irq(&conf->device_lock);
5191 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
fef9c61f 5192 conf->reshape_progress = MaxSector;
29269553
N		 5193 spin_unlock_irq(&conf->device_lock);
5194 return -EAGAIN;
5195 }
c8f517c4 5196 conf->reshape_checkpoint = jiffies;
29269553
N		 5197 md_wakeup_thread(mddev->sync_thread);
5198 md_new_event(mddev);
5199 return 0;
5200}
29269553 5201
ec32a2bd
N		 5202/* This is called from the reshape thread and should make any
5203 * changes needed in 'conf'
5204 */
29269553
N		 5205static void end_reshape(raid5_conf_t *conf)
5206{
29269553 5207
f6705578 5208 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
f6705578 5209
f6705578 5210 spin_lock_irq(&conf->device_lock);
cea9c228 5211 conf->previous_raid_disks = conf->raid_disks;
fef9c61f 5212 conf->reshape_progress = MaxSector;
f6705578 5213 spin_unlock_irq(&conf->device_lock);
b0f9ec04 5214 wake_up(&conf->wait_for_overlap);
16a53ecc
N		 5215
5216 /* read-ahead size must cover two whole stripes, which is
5217 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5218 */
4a5add49 5219 if (conf->mddev->queue) {
cea9c228 5220 int data_disks = conf->raid_disks - conf->max_degraded;
09c9e5fa 5221 int stripe = data_disks * ((conf->chunk_sectors << 9)
cea9c228 5222 / PAGE_SIZE);
16a53ecc
N		 5223 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5224 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5225 }
29269553 5226 }
29269553
N		 5227}
5228
ec32a2bd
N		 5229/* This is called from the raid5d thread with mddev_lock held.
5230 * It makes config changes to the device.
5231 */
cea9c228
N		 5232static void raid5_finish_reshape(mddev_t *mddev)
5233{
070ec55d 5234 raid5_conf_t *conf = mddev->private;
cea9c228
N		 5235
5236 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5237
ec32a2bd
N		 5238 if (mddev->delta_disks > 0) {
5239 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5240 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 5241 revalidate_disk(mddev->gendisk);
ec32a2bd
N		 5242 } else {
5243 int d;
ec32a2bd
N		 5244 mddev->degraded = conf->raid_disks;
5245 for (d = 0; d < conf->raid_disks ; d++)
5246 if (conf->disks[d].rdev &&
5247 test_bit(In_sync,
5248 &conf->disks[d].rdev->flags))
5249 mddev->degraded--;
5250 for (d = conf->raid_disks ;
5251 d < conf->raid_disks - mddev->delta_disks;
1a67dde0
N		 5252 d++) {
5253 mdk_rdev_t *rdev = conf->disks[d].rdev;
5254 if (rdev && raid5_remove_disk(mddev, d) == 0) {
36fad858 5255 sysfs_unlink_rdev(mddev, rdev);
1a67dde0
N		 5256 rdev->raid_disk = -1;
5257 }
5258 }
cea9c228 5259 }
88ce4930 5260 mddev->layout = conf->algorithm;
09c9e5fa 5261 mddev->chunk_sectors = conf->chunk_sectors;
ec32a2bd
N		 5262 mddev->reshape_position = MaxSector;
5263 mddev->delta_disks = 0;
cea9c228
N		 5264 }
5265}
5266
72626685
N		 5267static void raid5_quiesce(mddev_t *mddev, int state)
5268{
070ec55d 5269 raid5_conf_t *conf = mddev->private;
72626685
N		 5270
5271 switch(state) {
e464eafd
N		 5272 case 2: /* resume for a suspend */
5273 wake_up(&conf->wait_for_overlap);
5274 break;
5275
72626685
N		 5276 case 1: /* stop all writes */
5277 spin_lock_irq(&conf->device_lock);
64bd660b
N		 5278 /* '2' tells resync/reshape to pause so that all
5279 * active stripes can drain
5280 */
5281 conf->quiesce = 2;
72626685 5282 wait_event_lock_irq(conf->wait_for_stripe,
46031f9a
RBJ		 5283 atomic_read(&conf->active_stripes) == 0 &&
5284 atomic_read(&conf->active_aligned_reads) == 0,
72626685 5285 conf->device_lock, /* nothing */);
64bd660b 5286 conf->quiesce = 1;
72626685 5287 spin_unlock_irq(&conf->device_lock);
64bd660b
N		 5288 /* allow reshape to continue */
5289 wake_up(&conf->wait_for_overlap);
72626685
N		 5290 break;
5291
5292 case 0: /* re-enable writes */
5293 spin_lock_irq(&conf->device_lock);
5294 conf->quiesce = 0;
5295 wake_up(&conf->wait_for_stripe);
e464eafd 5296 wake_up(&conf->wait_for_overlap);
72626685
N		 5297 spin_unlock_irq(&conf->device_lock);
5298 break;
5299 }
72626685 5300}
b15c2e57 5301
d562b0c4 5302
f1b29bca 5303static void *raid45_takeover_raid0(mddev_t *mddev, int level)
54071b38 5304{
f1b29bca 5305 struct raid0_private_data *raid0_priv = mddev->private;
d76c8420 5306 sector_t sectors;
54071b38 5307
f1b29bca
DW		 5308 /* for raid0 takeover only one zone is supported */
5309 if (raid0_priv->nr_strip_zones > 1) {
0c55e022
N		 5310 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5311 mdname(mddev));
f1b29bca
DW		 5312 return ERR_PTR(-EINVAL);
5313 }
5314
3b71bd93
N		 5315 sectors = raid0_priv->strip_zone[0].zone_end;
5316 sector_div(sectors, raid0_priv->strip_zone[0].nb_dev);
5317 mddev->dev_sectors = sectors;
f1b29bca 5318 mddev->new_level = level;
54071b38
TM		 5319 mddev->new_layout = ALGORITHM_PARITY_N;
5320 mddev->new_chunk_sectors = mddev->chunk_sectors;
5321 mddev->raid_disks += 1;
5322 mddev->delta_disks = 1;
5323 /* make sure it will be not marked as dirty */
5324 mddev->recovery_cp = MaxSector;
5325
5326 return setup_conf(mddev);
5327}
5328
5329
d562b0c4
N		 5330static void *raid5_takeover_raid1(mddev_t *mddev)
5331{
5332 int chunksect;
5333
5334 if (mddev->raid_disks != 2 ||
5335 mddev->degraded > 1)
5336 return ERR_PTR(-EINVAL);
5337
5338 /* Should check if there are write-behind devices? */
5339
5340 chunksect = 64*2; /* 64K by default */
5341
5342 /* The array must be an exact multiple of chunksize */
5343 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5344 chunksect >>= 1;
5345
5346 if ((chunksect<<9) < STRIPE_SIZE)
5347 /* array size does not allow a suitable chunk size */
5348 return ERR_PTR(-EINVAL);
5349
5350 mddev->new_level = 5;
5351 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
664e7c41 5352 mddev->new_chunk_sectors = chunksect;
d562b0c4
N		 5353
5354 return setup_conf(mddev);
5355}
5356
fc9739c6
N		 5357static void *raid5_takeover_raid6(mddev_t *mddev)
5358{
5359 int new_layout;
5360
5361 switch (mddev->layout) {
5362 case ALGORITHM_LEFT_ASYMMETRIC_6:
5363 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5364 break;
5365 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5366 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5367 break;
5368 case ALGORITHM_LEFT_SYMMETRIC_6:
5369 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5370 break;
5371 case ALGORITHM_RIGHT_SYMMETRIC_6:
5372 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5373 break;
5374 case ALGORITHM_PARITY_0_6:
5375 new_layout = ALGORITHM_PARITY_0;
5376 break;
5377 case ALGORITHM_PARITY_N:
5378 new_layout = ALGORITHM_PARITY_N;
5379 break;
5380 default:
5381 return ERR_PTR(-EINVAL);
5382 }
5383 mddev->new_level = 5;
5384 mddev->new_layout = new_layout;
5385 mddev->delta_disks = -1;
5386 mddev->raid_disks -= 1;
5387 return setup_conf(mddev);
5388}
5389
d562b0c4 5390
50ac168a 5391static int raid5_check_reshape(mddev_t *mddev)
b3546035 5392{
88ce4930
N		 5393 /* For a 2-drive array, the layout and chunk size can be changed
5394 * immediately as not restriping is needed.
5395 * For larger arrays we record the new value - after validation
5396 * to be used by a reshape pass.
b3546035 5397 */
070ec55d 5398 raid5_conf_t *conf = mddev->private;
597a711b 5399 int new_chunk = mddev->new_chunk_sectors;
b3546035 5400
597a711b 5401 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
b3546035
N		 5402 return -EINVAL;
5403 if (new_chunk > 0) {
0ba459d2 5404 if (!is_power_of_2(new_chunk))
b3546035 5405 return -EINVAL;
597a711b 5406 if (new_chunk < (PAGE_SIZE>>9))
b3546035 5407 return -EINVAL;
597a711b 5408 if (mddev->array_sectors & (new_chunk-1))
b3546035
N		 5409 /* not factor of array size */
5410 return -EINVAL;
5411 }
5412
5413 /* They look valid */
5414
88ce4930 5415 if (mddev->raid_disks == 2) {
597a711b
N		 5416 /* can make the change immediately */
5417 if (mddev->new_layout >= 0) {
5418 conf->algorithm = mddev->new_layout;
5419 mddev->layout = mddev->new_layout;
88ce4930
N		 5420 }
5421 if (new_chunk > 0) {
597a711b
N		 5422 conf->chunk_sectors = new_chunk ;
5423 mddev->chunk_sectors = new_chunk;
88ce4930
N		 5424 }
5425 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5426 md_wakeup_thread(mddev->thread);
b3546035 5427 }
50ac168a 5428 return check_reshape(mddev);
88ce4930
N		 5429}
5430
50ac168a 5431static int raid6_check_reshape(mddev_t *mddev)
88ce4930 5432{
597a711b 5433 int new_chunk = mddev->new_chunk_sectors;
50ac168a 5434
597a711b 5435 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
88ce4930 5436 return -EINVAL;
b3546035 5437 if (new_chunk > 0) {
0ba459d2 5438 if (!is_power_of_2(new_chunk))
88ce4930 5439 return -EINVAL;
597a711b 5440 if (new_chunk < (PAGE_SIZE >> 9))
88ce4930 5441 return -EINVAL;
597a711b 5442 if (mddev->array_sectors & (new_chunk-1))
88ce4930
N		 5443 /* not factor of array size */
5444 return -EINVAL;
b3546035 5445 }
88ce4930
N		 5446
5447 /* They look valid */
50ac168a 5448 return check_reshape(mddev);
b3546035
N		 5449}
5450
d562b0c4
N		 5451static void *raid5_takeover(mddev_t *mddev)
5452{
5453 /* raid5 can take over:
f1b29bca 5454 * raid0 - if there is only one strip zone - make it a raid4 layout
d562b0c4
N		 5455 * raid1 - if there are two drives. We need to know the chunk size
5456 * raid4 - trivial - just use a raid4 layout.
5457 * raid6 - Providing it is a *_6 layout
d562b0c4 5458 */
f1b29bca
DW		 5459 if (mddev->level == 0)
5460 return raid45_takeover_raid0(mddev, 5);
d562b0c4
N		 5461 if (mddev->level == 1)
5462 return raid5_takeover_raid1(mddev);
e9d4758f
N		 5463 if (mddev->level == 4) {
5464 mddev->new_layout = ALGORITHM_PARITY_N;
5465 mddev->new_level = 5;
5466 return setup_conf(mddev);
5467 }
fc9739c6
N		 5468 if (mddev->level == 6)
5469 return raid5_takeover_raid6(mddev);
d562b0c4
N		 5470
5471 return ERR_PTR(-EINVAL);
5472}
5473
a78d38a1
N		 5474static void *raid4_takeover(mddev_t *mddev)
5475{
f1b29bca
DW		 5476 /* raid4 can take over:
5477 * raid0 - if there is only one strip zone
5478 * raid5 - if layout is right
a78d38a1 5479 */
f1b29bca
DW		 5480 if (mddev->level == 0)
5481 return raid45_takeover_raid0(mddev, 4);
a78d38a1
N		 5482 if (mddev->level == 5 &&
5483 mddev->layout == ALGORITHM_PARITY_N) {
5484 mddev->new_layout = 0;
5485 mddev->new_level = 4;
5486 return setup_conf(mddev);
5487 }
5488 return ERR_PTR(-EINVAL);
5489}
d562b0c4 5490
245f46c2
N		 5491static struct mdk_personality raid5_personality;
5492
5493static void *raid6_takeover(mddev_t *mddev)
5494{
5495 /* Currently can only take over a raid5. We map the
5496 * personality to an equivalent raid6 personality
5497 * with the Q block at the end.
5498 */
5499 int new_layout;
5500
5501 if (mddev->pers != &raid5_personality)
5502 return ERR_PTR(-EINVAL);
5503 if (mddev->degraded > 1)
5504 return ERR_PTR(-EINVAL);
5505 if (mddev->raid_disks > 253)
5506 return ERR_PTR(-EINVAL);
5507 if (mddev->raid_disks < 3)
5508 return ERR_PTR(-EINVAL);
5509
5510 switch (mddev->layout) {
5511 case ALGORITHM_LEFT_ASYMMETRIC:
5512 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5513 break;
5514 case ALGORITHM_RIGHT_ASYMMETRIC:
5515 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5516 break;
5517 case ALGORITHM_LEFT_SYMMETRIC:
5518 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5519 break;
5520 case ALGORITHM_RIGHT_SYMMETRIC:
5521 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5522 break;
5523 case ALGORITHM_PARITY_0:
5524 new_layout = ALGORITHM_PARITY_0_6;
5525 break;
5526 case ALGORITHM_PARITY_N:
5527 new_layout = ALGORITHM_PARITY_N;
5528 break;
5529 default:
5530 return ERR_PTR(-EINVAL);
5531 }
5532 mddev->new_level = 6;
5533 mddev->new_layout = new_layout;
5534 mddev->delta_disks = 1;
5535 mddev->raid_disks += 1;
5536 return setup_conf(mddev);
5537}
5538
5539
16a53ecc
N		 5540static struct mdk_personality raid6_personality =
5541{
5542 .name = "raid6",
5543 .level = 6,
5544 .owner = THIS_MODULE,
5545 .make_request = make_request,
5546 .run = run,
5547 .stop = stop,
5548 .status = status,
5549 .error_handler = error,
5550 .hot_add_disk = raid5_add_disk,
5551 .hot_remove_disk= raid5_remove_disk,
5552 .spare_active = raid5_spare_active,
5553 .sync_request = sync_request,
5554 .resize = raid5_resize,
80c3a6ce 5555 .size = raid5_size,
50ac168a 5556 .check_reshape = raid6_check_reshape,
f416885e 5557 .start_reshape = raid5_start_reshape,
cea9c228 5558 .finish_reshape = raid5_finish_reshape,
16a53ecc 5559 .quiesce = raid5_quiesce,
245f46c2 5560 .takeover = raid6_takeover,
16a53ecc 5561};
2604b703 5562static struct mdk_personality raid5_personality =
1da177e4
LT		 5563{
5564 .name = "raid5",
2604b703 5565 .level = 5,
1da177e4
LT		 5566 .owner = THIS_MODULE,
5567 .make_request = make_request,
5568 .run = run,
5569 .stop = stop,
5570 .status = status,
5571 .error_handler = error,
5572 .hot_add_disk = raid5_add_disk,
5573 .hot_remove_disk= raid5_remove_disk,
5574 .spare_active = raid5_spare_active,
5575 .sync_request = sync_request,
5576 .resize = raid5_resize,
80c3a6ce 5577 .size = raid5_size,
63c70c4f
N		 5578 .check_reshape = raid5_check_reshape,
5579 .start_reshape = raid5_start_reshape,
cea9c228 5580 .finish_reshape = raid5_finish_reshape,
72626685 5581 .quiesce = raid5_quiesce,
d562b0c4 5582 .takeover = raid5_takeover,
1da177e4
LT		 5583};
5584
2604b703 5585static struct mdk_personality raid4_personality =
1da177e4 5586{
2604b703
N		 5587 .name = "raid4",
5588 .level = 4,
5589 .owner = THIS_MODULE,
5590 .make_request = make_request,
5591 .run = run,
5592 .stop = stop,
5593 .status = status,
5594 .error_handler = error,
5595 .hot_add_disk = raid5_add_disk,
5596 .hot_remove_disk= raid5_remove_disk,
5597 .spare_active = raid5_spare_active,
5598 .sync_request = sync_request,
5599 .resize = raid5_resize,
80c3a6ce 5600 .size = raid5_size,
3d37890b
N		 5601 .check_reshape = raid5_check_reshape,
5602 .start_reshape = raid5_start_reshape,
cea9c228 5603 .finish_reshape = raid5_finish_reshape,
2604b703 5604 .quiesce = raid5_quiesce,
a78d38a1 5605 .takeover = raid4_takeover,
2604b703
N		 5606};
5607
5608static int __init raid5_init(void)
5609{
16a53ecc 5610 register_md_personality(&raid6_personality);
2604b703
N		 5611 register_md_personality(&raid5_personality);
5612 register_md_personality(&raid4_personality);
5613 return 0;
1da177e4
LT		 5614}
5615
2604b703 5616static void raid5_exit(void)
1da177e4 5617{
16a53ecc 5618 unregister_md_personality(&raid6_personality);
2604b703
N		 5619 unregister_md_personality(&raid5_personality);
5620 unregister_md_personality(&raid4_personality);
1da177e4
LT		 5621}
5622
5623module_init(raid5_init);
5624module_exit(raid5_exit);
5625MODULE_LICENSE("GPL");
0efb9e61 5626MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
1da177e4 5627MODULE_ALIAS("md-personality-4"); /* RAID5 */
d9d166c2
N		 5628MODULE_ALIAS("md-raid5");
5629MODULE_ALIAS("md-raid4");
2604b703
N		 5630MODULE_ALIAS("md-level-5");
5631MODULE_ALIAS("md-level-4");
16a53ecc
N		 5632MODULE_ALIAS("md-personality-8"); /* RAID6 */
5633MODULE_ALIAS("md-raid6");
5634MODULE_ALIAS("md-level-6");
5635
5636/* This used to be two separate modules, they were: */
5637MODULE_ALIAS("raid5");
5638MODULE_ALIAS("raid6");
Linux 6.x block layer and io_uring tree(s)