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md/raid5: rearrange a test in fetch_block6.
[GitHub/LineageOS/android_kernel_motorola_exynos9610.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>
43b2e5d8 54#include "md.h"
bff61975 55#include "raid5.h"
54071b38 56#include "raid0.h"
ef740c37 57#include "bitmap.h"
72626685 58
1da177e4
LT		 59/*
60 * Stripe cache
61 */
62
63#define NR_STRIPES 256
64#define STRIPE_SIZE PAGE_SIZE
65#define STRIPE_SHIFT (PAGE_SHIFT - 9)
66#define STRIPE_SECTORS (STRIPE_SIZE>>9)
67#define IO_THRESHOLD 1
8b3e6cdc 68#define BYPASS_THRESHOLD 1
fccddba0 69#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
1da177e4
LT		 70#define HASH_MASK (NR_HASH - 1)
71
fccddba0 72#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
1da177e4
LT		 73
74/* bio's attached to a stripe+device for I/O are linked together in bi_sector
75 * order without overlap. There may be several bio's per stripe+device, and
76 * a bio could span several devices.
77 * When walking this list for a particular stripe+device, we must never proceed
78 * beyond a bio that extends past this device, as the next bio might no longer
79 * be valid.
80 * This macro is used to determine the 'next' bio in the list, given the sector
81 * of the current stripe+device
82 */
83#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
84/*
85 * The following can be used to debug the driver
86 */
1da177e4
LT		 87#define RAID5_PARANOIA 1
88#if RAID5_PARANOIA && defined(CONFIG_SMP)
89# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
90#else
91# define CHECK_DEVLOCK()
92#endif
93
45b4233c 94#ifdef DEBUG
1da177e4
LT		 95#define inline
96#define __inline__
97#endif
98
6be9d494
BS		 99#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
100
960e739d 101/*
5b99c2ff
JA		 102 * We maintain a biased count of active stripes in the bottom 16 bits of
103 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
960e739d
JA		 104 */
105static inline int raid5_bi_phys_segments(struct bio *bio)
106{
5b99c2ff 107 return bio->bi_phys_segments & 0xffff;
960e739d
JA		 108}
109
110static inline int raid5_bi_hw_segments(struct bio *bio)
111{
5b99c2ff 112 return (bio->bi_phys_segments >> 16) & 0xffff;
960e739d
JA		 113}
114
115static inline int raid5_dec_bi_phys_segments(struct bio *bio)
116{
117 --bio->bi_phys_segments;
118 return raid5_bi_phys_segments(bio);
119}
120
121static inline int raid5_dec_bi_hw_segments(struct bio *bio)
122{
123 unsigned short val = raid5_bi_hw_segments(bio);
124
125 --val;
5b99c2ff 126 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
960e739d
JA		 127 return val;
128}
129
130static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
131{
9b2dc8b6 132 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16);
960e739d
JA		 133}
134
d0dabf7e
N		 135/* Find first data disk in a raid6 stripe */
136static inline int raid6_d0(struct stripe_head *sh)
137{
67cc2b81
N		 138 if (sh->ddf_layout)
139 /* ddf always start from first device */
140 return 0;
141 /* md starts just after Q block */
d0dabf7e
N		 142 if (sh->qd_idx == sh->disks - 1)
143 return 0;
144 else
145 return sh->qd_idx + 1;
146}
16a53ecc
N		 147static inline int raid6_next_disk(int disk, int raid_disks)
148{
149 disk++;
150 return (disk < raid_disks) ? disk : 0;
151}
a4456856 152
d0dabf7e
N		 153/* When walking through the disks in a raid5, starting at raid6_d0,
154 * We need to map each disk to a 'slot', where the data disks are slot
155 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
156 * is raid_disks-1. This help does that mapping.
157 */
67cc2b81
N		 158static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
159 int *count, int syndrome_disks)
d0dabf7e 160{
6629542e 161 int slot = *count;
67cc2b81 162
e4424fee 163 if (sh->ddf_layout)
6629542e 164 (*count)++;
d0dabf7e 165 if (idx == sh->pd_idx)
67cc2b81 166 return syndrome_disks;
d0dabf7e 167 if (idx == sh->qd_idx)
67cc2b81 168 return syndrome_disks + 1;
e4424fee 169 if (!sh->ddf_layout)
6629542e 170 (*count)++;
d0dabf7e
N		 171 return slot;
172}
173
a4456856
DW		 174static void return_io(struct bio *return_bi)
175{
176 struct bio *bi = return_bi;
177 while (bi) {
a4456856
DW		 178
179 return_bi = bi->bi_next;
180 bi->bi_next = NULL;
181 bi->bi_size = 0;
0e13fe23 182 bio_endio(bi, 0);
a4456856
DW		 183 bi = return_bi;
184 }
185}
186
1da177e4
LT		 187static void print_raid5_conf (raid5_conf_t *conf);
188
600aa109
DW		 189static int stripe_operations_active(struct stripe_head *sh)
190{
191 return sh->check_state || sh->reconstruct_state ||
192 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
193 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
194}
195
858119e1 196static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
1da177e4
LT		 197{
198 if (atomic_dec_and_test(&sh->count)) {
78bafebd
ES		 199 BUG_ON(!list_empty(&sh->lru));
200 BUG_ON(atomic_read(&conf->active_stripes)==0);
1da177e4 201 if (test_bit(STRIPE_HANDLE, &sh->state)) {
482c0834 202 if (test_bit(STRIPE_DELAYED, &sh->state))
1da177e4 203 list_add_tail(&sh->lru, &conf->delayed_list);
482c0834
N		 204 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
205 sh->bm_seq - conf->seq_write > 0)
72626685 206 list_add_tail(&sh->lru, &conf->bitmap_list);
482c0834 207 else {
72626685 208 clear_bit(STRIPE_BIT_DELAY, &sh->state);
1da177e4 209 list_add_tail(&sh->lru, &conf->handle_list);
72626685 210 }
1da177e4
LT		 211 md_wakeup_thread(conf->mddev->thread);
212 } else {
600aa109 213 BUG_ON(stripe_operations_active(sh));
1da177e4
LT		 214 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
215 atomic_dec(&conf->preread_active_stripes);
216 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
217 md_wakeup_thread(conf->mddev->thread);
218 }
1da177e4 219 atomic_dec(&conf->active_stripes);
ccfcc3c1
N		 220 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
221 list_add_tail(&sh->lru, &conf->inactive_list);
1da177e4 222 wake_up(&conf->wait_for_stripe);
46031f9a
RBJ		 223 if (conf->retry_read_aligned)
224 md_wakeup_thread(conf->mddev->thread);
ccfcc3c1 225 }
1da177e4
LT		 226 }
227 }
228}
d0dabf7e 229
1da177e4
LT		 230static void release_stripe(struct stripe_head *sh)
231{
232 raid5_conf_t *conf = sh->raid_conf;
233 unsigned long flags;
16a53ecc 234
1da177e4
LT		 235 spin_lock_irqsave(&conf->device_lock, flags);
236 __release_stripe(conf, sh);
237 spin_unlock_irqrestore(&conf->device_lock, flags);
238}
239
fccddba0 240static inline void remove_hash(struct stripe_head *sh)
1da177e4 241{
45b4233c
DW		 242 pr_debug("remove_hash(), stripe %llu\n",
243 (unsigned long long)sh->sector);
1da177e4 244
fccddba0 245 hlist_del_init(&sh->hash);
1da177e4
LT		 246}
247
16a53ecc 248static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
1da177e4 249{
fccddba0 250 struct hlist_head *hp = stripe_hash(conf, sh->sector);
1da177e4 251
45b4233c
DW		 252 pr_debug("insert_hash(), stripe %llu\n",
253 (unsigned long long)sh->sector);
1da177e4
LT		 254
255 CHECK_DEVLOCK();
fccddba0 256 hlist_add_head(&sh->hash, hp);
1da177e4
LT		 257}
258
259
260/* find an idle stripe, make sure it is unhashed, and return it. */
261static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
262{
263 struct stripe_head *sh = NULL;
264 struct list_head *first;
265
266 CHECK_DEVLOCK();
267 if (list_empty(&conf->inactive_list))
268 goto out;
269 first = conf->inactive_list.next;
270 sh = list_entry(first, struct stripe_head, lru);
271 list_del_init(first);
272 remove_hash(sh);
273 atomic_inc(&conf->active_stripes);
274out:
275 return sh;
276}
277
e4e11e38 278static void shrink_buffers(struct stripe_head *sh)
1da177e4
LT		 279{
280 struct page *p;
281 int i;
e4e11e38 282 int num = sh->raid_conf->pool_size;
1da177e4 283
e4e11e38 284 for (i = 0; i < num ; i++) {
1da177e4
LT		 285 p = sh->dev[i].page;
286 if (!p)
287 continue;
288 sh->dev[i].page = NULL;
2d1f3b5d 289 put_page(p);
1da177e4
LT		 290 }
291}
292
e4e11e38 293static int grow_buffers(struct stripe_head *sh)
1da177e4
LT		 294{
295 int i;
e4e11e38 296 int num = sh->raid_conf->pool_size;
1da177e4 297
e4e11e38 298 for (i = 0; i < num; i++) {
1da177e4
LT		 299 struct page *page;
300
301 if (!(page = alloc_page(GFP_KERNEL))) {
302 return 1;
303 }
304 sh->dev[i].page = page;
305 }
306 return 0;
307}
308
784052ec 309static void raid5_build_block(struct stripe_head *sh, int i, int previous);
911d4ee8
N		 310static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
311 struct stripe_head *sh);
1da177e4 312
b5663ba4 313static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
1da177e4
LT		 314{
315 raid5_conf_t *conf = sh->raid_conf;
7ecaa1e6 316 int i;
1da177e4 317
78bafebd
ES		 318 BUG_ON(atomic_read(&sh->count) != 0);
319 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
600aa109 320 BUG_ON(stripe_operations_active(sh));
d84e0f10 321
1da177e4 322 CHECK_DEVLOCK();
45b4233c 323 pr_debug("init_stripe called, stripe %llu\n",
1da177e4
LT		 324 (unsigned long long)sh->sector);
325
326 remove_hash(sh);
16a53ecc 327
86b42c71 328 sh->generation = conf->generation - previous;
b5663ba4 329 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
1da177e4 330 sh->sector = sector;
911d4ee8 331 stripe_set_idx(sector, conf, previous, sh);
1da177e4
LT		 332 sh->state = 0;
333
7ecaa1e6
N		 334
335 for (i = sh->disks; i--; ) {
1da177e4
LT		 336 struct r5dev *dev = &sh->dev[i];
337
d84e0f10 338 if (dev->toread || dev->read || dev->towrite || dev->written ||
1da177e4 339 test_bit(R5_LOCKED, &dev->flags)) {
d84e0f10 340 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
1da177e4 341 (unsigned long long)sh->sector, i, dev->toread,
d84e0f10 342 dev->read, dev->towrite, dev->written,
1da177e4
LT		 343 test_bit(R5_LOCKED, &dev->flags));
344 BUG();
345 }
346 dev->flags = 0;
784052ec 347 raid5_build_block(sh, i, previous);
1da177e4
LT		 348 }
349 insert_hash(conf, sh);
350}
351
86b42c71
N		 352static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
353 short generation)
1da177e4
LT		 354{
355 struct stripe_head *sh;
fccddba0 356 struct hlist_node *hn;
1da177e4
LT		 357
358 CHECK_DEVLOCK();
45b4233c 359 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
fccddba0 360 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
86b42c71 361 if (sh->sector == sector && sh->generation == generation)
1da177e4 362 return sh;
45b4233c 363 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
1da177e4
LT		 364 return NULL;
365}
366
674806d6
N		 367/*
368 * Need to check if array has failed when deciding whether to:
369 * - start an array
370 * - remove non-faulty devices
371 * - add a spare
372 * - allow a reshape
373 * This determination is simple when no reshape is happening.
374 * However if there is a reshape, we need to carefully check
375 * both the before and after sections.
376 * This is because some failed devices may only affect one
377 * of the two sections, and some non-in_sync devices may
378 * be insync in the section most affected by failed devices.
379 */
380static int has_failed(raid5_conf_t *conf)
381{
382 int degraded;
383 int i;
384 if (conf->mddev->reshape_position == MaxSector)
385 return conf->mddev->degraded > conf->max_degraded;
386
387 rcu_read_lock();
388 degraded = 0;
389 for (i = 0; i < conf->previous_raid_disks; i++) {
390 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
391 if (!rdev || test_bit(Faulty, &rdev->flags))
392 degraded++;
393 else if (test_bit(In_sync, &rdev->flags))
394 ;
395 else
396 /* not in-sync or faulty.
397 * If the reshape increases the number of devices,
398 * this is being recovered by the reshape, so
399 * this 'previous' section is not in_sync.
400 * If the number of devices is being reduced however,
401 * the device can only be part of the array if
402 * we are reverting a reshape, so this section will
403 * be in-sync.
404 */
405 if (conf->raid_disks >= conf->previous_raid_disks)
406 degraded++;
407 }
408 rcu_read_unlock();
409 if (degraded > conf->max_degraded)
410 return 1;
411 rcu_read_lock();
412 degraded = 0;
413 for (i = 0; i < conf->raid_disks; i++) {
414 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
415 if (!rdev || test_bit(Faulty, &rdev->flags))
416 degraded++;
417 else if (test_bit(In_sync, &rdev->flags))
418 ;
419 else
420 /* not in-sync or faulty.
421 * If reshape increases the number of devices, this
422 * section has already been recovered, else it
423 * almost certainly hasn't.
424 */
425 if (conf->raid_disks <= conf->previous_raid_disks)
426 degraded++;
427 }
428 rcu_read_unlock();
429 if (degraded > conf->max_degraded)
430 return 1;
431 return 0;
432}
433
b5663ba4
N		 434static struct stripe_head *
435get_active_stripe(raid5_conf_t *conf, sector_t sector,
a8c906ca 436 int previous, int noblock, int noquiesce)
1da177e4
LT		 437{
438 struct stripe_head *sh;
439
45b4233c 440 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
1da177e4
LT		 441
442 spin_lock_irq(&conf->device_lock);
443
444 do {
72626685 445 wait_event_lock_irq(conf->wait_for_stripe,
a8c906ca 446 conf->quiesce == 0 || noquiesce,
72626685 447 conf->device_lock, /* nothing */);
86b42c71 448 sh = __find_stripe(conf, sector, conf->generation - previous);
1da177e4
LT		 449 if (!sh) {
450 if (!conf->inactive_blocked)
451 sh = get_free_stripe(conf);
452 if (noblock && sh == NULL)
453 break;
454 if (!sh) {
455 conf->inactive_blocked = 1;
456 wait_event_lock_irq(conf->wait_for_stripe,
457 !list_empty(&conf->inactive_list) &&
5036805b
N		 458 (atomic_read(&conf->active_stripes)
459 < (conf->max_nr_stripes *3/4)
1da177e4
LT		 460 || !conf->inactive_blocked),
461 conf->device_lock,
7c13edc8 462 );
1da177e4
LT		 463 conf->inactive_blocked = 0;
464 } else
b5663ba4 465 init_stripe(sh, sector, previous);
1da177e4
LT		 466 } else {
467 if (atomic_read(&sh->count)) {
ab69ae12
N		 468 BUG_ON(!list_empty(&sh->lru)
469 && !test_bit(STRIPE_EXPANDING, &sh->state));
1da177e4
LT		 470 } else {
471 if (!test_bit(STRIPE_HANDLE, &sh->state))
472 atomic_inc(&conf->active_stripes);
ff4e8d9a
N		 473 if (list_empty(&sh->lru) &&
474 !test_bit(STRIPE_EXPANDING, &sh->state))
16a53ecc
N		 475 BUG();
476 list_del_init(&sh->lru);
1da177e4
LT		 477 }
478 }
479 } while (sh == NULL);
480
481 if (sh)
482 atomic_inc(&sh->count);
483
484 spin_unlock_irq(&conf->device_lock);
485 return sh;
486}
487
6712ecf8
N		 488static void
489raid5_end_read_request(struct bio *bi, int error);
490static void
491raid5_end_write_request(struct bio *bi, int error);
91c00924 492
c4e5ac0a 493static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
91c00924
DW		 494{
495 raid5_conf_t *conf = sh->raid_conf;
496 int i, disks = sh->disks;
497
498 might_sleep();
499
500 for (i = disks; i--; ) {
501 int rw;
502 struct bio *bi;
503 mdk_rdev_t *rdev;
e9c7469b
TH		 504 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
505 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
506 rw = WRITE_FUA;
507 else
508 rw = WRITE;
509 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
91c00924
DW		 510 rw = READ;
511 else
512 continue;
513
514 bi = &sh->dev[i].req;
515
516 bi->bi_rw = rw;
b062962e 517 if (rw & WRITE)
91c00924
DW		 518 bi->bi_end_io = raid5_end_write_request;
519 else
520 bi->bi_end_io = raid5_end_read_request;
521
522 rcu_read_lock();
523 rdev = rcu_dereference(conf->disks[i].rdev);
524 if (rdev && test_bit(Faulty, &rdev->flags))
525 rdev = NULL;
526 if (rdev)
527 atomic_inc(&rdev->nr_pending);
528 rcu_read_unlock();
529
530 if (rdev) {
c4e5ac0a 531 if (s->syncing || s->expanding || s->expanded)
91c00924
DW		 532 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
533
2b7497f0
DW		 534 set_bit(STRIPE_IO_STARTED, &sh->state);
535
91c00924
DW		 536 bi->bi_bdev = rdev->bdev;
537 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
e46b272b 538 __func__, (unsigned long long)sh->sector,
91c00924
DW		 539 bi->bi_rw, i);
540 atomic_inc(&sh->count);
541 bi->bi_sector = sh->sector + rdev->data_offset;
542 bi->bi_flags = 1 << BIO_UPTODATE;
543 bi->bi_vcnt = 1;
544 bi->bi_max_vecs = 1;
545 bi->bi_idx = 0;
546 bi->bi_io_vec = &sh->dev[i].vec;
547 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
548 bi->bi_io_vec[0].bv_offset = 0;
549 bi->bi_size = STRIPE_SIZE;
550 bi->bi_next = NULL;
b062962e 551 if ((rw & WRITE) &&
91c00924
DW		 552 test_bit(R5_ReWrite, &sh->dev[i].flags))
553 atomic_add(STRIPE_SECTORS,
554 &rdev->corrected_errors);
555 generic_make_request(bi);
556 } else {
b062962e 557 if (rw & WRITE)
91c00924
DW		 558 set_bit(STRIPE_DEGRADED, &sh->state);
559 pr_debug("skip op %ld on disc %d for sector %llu\n",
560 bi->bi_rw, i, (unsigned long long)sh->sector);
561 clear_bit(R5_LOCKED, &sh->dev[i].flags);
562 set_bit(STRIPE_HANDLE, &sh->state);
563 }
564 }
565}
566
567static struct dma_async_tx_descriptor *
568async_copy_data(int frombio, struct bio *bio, struct page *page,
569 sector_t sector, struct dma_async_tx_descriptor *tx)
570{
571 struct bio_vec *bvl;
572 struct page *bio_page;
573 int i;
574 int page_offset;
a08abd8c 575 struct async_submit_ctl submit;
0403e382 576 enum async_tx_flags flags = 0;
91c00924
DW		 577
578 if (bio->bi_sector >= sector)
579 page_offset = (signed)(bio->bi_sector - sector) * 512;
580 else
581 page_offset = (signed)(sector - bio->bi_sector) * -512;
a08abd8c 582
0403e382
DW		 583 if (frombio)
584 flags |= ASYNC_TX_FENCE;
585 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
586
91c00924 587 bio_for_each_segment(bvl, bio, i) {
fcde9075 588 int len = bvl->bv_len;
91c00924
DW		 589 int clen;
590 int b_offset = 0;
591
592 if (page_offset < 0) {
593 b_offset = -page_offset;
594 page_offset += b_offset;
595 len -= b_offset;
596 }
597
598 if (len > 0 && page_offset + len > STRIPE_SIZE)
599 clen = STRIPE_SIZE - page_offset;
600 else
601 clen = len;
602
603 if (clen > 0) {
fcde9075
NK		 604 b_offset += bvl->bv_offset;
605 bio_page = bvl->bv_page;
91c00924
DW		 606 if (frombio)
607 tx = async_memcpy(page, bio_page, page_offset,
a08abd8c 608 b_offset, clen, &submit);
91c00924
DW		 609 else
610 tx = async_memcpy(bio_page, page, b_offset,
a08abd8c 611 page_offset, clen, &submit);
91c00924 612 }
a08abd8c
DW		 613 /* chain the operations */
614 submit.depend_tx = tx;
615
91c00924
DW		 616 if (clen < len) /* hit end of page */
617 break;
618 page_offset += len;
619 }
620
621 return tx;
622}
623
624static void ops_complete_biofill(void *stripe_head_ref)
625{
626 struct stripe_head *sh = stripe_head_ref;
627 struct bio *return_bi = NULL;
628 raid5_conf_t *conf = sh->raid_conf;
e4d84909 629 int i;
91c00924 630
e46b272b 631 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 632 (unsigned long long)sh->sector);
633
634 /* clear completed biofills */
83de75cc 635 spin_lock_irq(&conf->device_lock);
91c00924
DW		 636 for (i = sh->disks; i--; ) {
637 struct r5dev *dev = &sh->dev[i];
91c00924
DW		 638
639 /* acknowledge completion of a biofill operation */
e4d84909
DW		 640 /* and check if we need to reply to a read request,
641 * new R5_Wantfill requests are held off until
83de75cc 642 * !STRIPE_BIOFILL_RUN
e4d84909
DW		 643 */
644 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
91c00924 645 struct bio *rbi, *rbi2;
91c00924 646
91c00924
DW		 647 BUG_ON(!dev->read);
648 rbi = dev->read;
649 dev->read = NULL;
650 while (rbi && rbi->bi_sector <
651 dev->sector + STRIPE_SECTORS) {
652 rbi2 = r5_next_bio(rbi, dev->sector);
960e739d 653 if (!raid5_dec_bi_phys_segments(rbi)) {
91c00924
DW		 654 rbi->bi_next = return_bi;
655 return_bi = rbi;
656 }
91c00924
DW		 657 rbi = rbi2;
658 }
659 }
660 }
83de75cc
DW		 661 spin_unlock_irq(&conf->device_lock);
662 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
91c00924
DW		 663
664 return_io(return_bi);
665
e4d84909 666 set_bit(STRIPE_HANDLE, &sh->state);
91c00924
DW		 667 release_stripe(sh);
668}
669
670static void ops_run_biofill(struct stripe_head *sh)
671{
672 struct dma_async_tx_descriptor *tx = NULL;
673 raid5_conf_t *conf = sh->raid_conf;
a08abd8c 674 struct async_submit_ctl submit;
91c00924
DW		 675 int i;
676
e46b272b 677 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 678 (unsigned long long)sh->sector);
679
680 for (i = sh->disks; i--; ) {
681 struct r5dev *dev = &sh->dev[i];
682 if (test_bit(R5_Wantfill, &dev->flags)) {
683 struct bio *rbi;
684 spin_lock_irq(&conf->device_lock);
685 dev->read = rbi = dev->toread;
686 dev->toread = NULL;
687 spin_unlock_irq(&conf->device_lock);
688 while (rbi && rbi->bi_sector <
689 dev->sector + STRIPE_SECTORS) {
690 tx = async_copy_data(0, rbi, dev->page,
691 dev->sector, tx);
692 rbi = r5_next_bio(rbi, dev->sector);
693 }
694 }
695 }
696
697 atomic_inc(&sh->count);
a08abd8c
DW		 698 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
699 async_trigger_callback(&submit);
91c00924
DW		 700}
701
4e7d2c0a 702static void mark_target_uptodate(struct stripe_head *sh, int target)
91c00924 703{
4e7d2c0a 704 struct r5dev *tgt;
91c00924 705
4e7d2c0a
DW		 706 if (target < 0)
707 return;
91c00924 708
4e7d2c0a 709 tgt = &sh->dev[target];
91c00924
DW		 710 set_bit(R5_UPTODATE, &tgt->flags);
711 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
712 clear_bit(R5_Wantcompute, &tgt->flags);
4e7d2c0a
DW		 713}
714
ac6b53b6 715static void ops_complete_compute(void *stripe_head_ref)
91c00924
DW		 716{
717 struct stripe_head *sh = stripe_head_ref;
91c00924 718
e46b272b 719 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 720 (unsigned long long)sh->sector);
721
ac6b53b6 722 /* mark the computed target(s) as uptodate */
4e7d2c0a 723 mark_target_uptodate(sh, sh->ops.target);
ac6b53b6 724 mark_target_uptodate(sh, sh->ops.target2);
4e7d2c0a 725
ecc65c9b
DW		 726 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
727 if (sh->check_state == check_state_compute_run)
728 sh->check_state = check_state_compute_result;
91c00924
DW		 729 set_bit(STRIPE_HANDLE, &sh->state);
730 release_stripe(sh);
731}
732
d6f38f31
DW		 733/* return a pointer to the address conversion region of the scribble buffer */
734static addr_conv_t *to_addr_conv(struct stripe_head *sh,
735 struct raid5_percpu *percpu)
736{
737 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
738}
739
740static struct dma_async_tx_descriptor *
741ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 742{
91c00924 743 int disks = sh->disks;
d6f38f31 744 struct page **xor_srcs = percpu->scribble;
91c00924
DW		 745 int target = sh->ops.target;
746 struct r5dev *tgt = &sh->dev[target];
747 struct page *xor_dest = tgt->page;
748 int count = 0;
749 struct dma_async_tx_descriptor *tx;
a08abd8c 750 struct async_submit_ctl submit;
91c00924
DW		 751 int i;
752
753 pr_debug("%s: stripe %llu block: %d\n",
e46b272b 754 __func__, (unsigned long long)sh->sector, target);
91c00924
DW		 755 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
756
757 for (i = disks; i--; )
758 if (i != target)
759 xor_srcs[count++] = sh->dev[i].page;
760
761 atomic_inc(&sh->count);
762
0403e382 763 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
ac6b53b6 764 ops_complete_compute, sh, to_addr_conv(sh, percpu));
91c00924 765 if (unlikely(count == 1))
a08abd8c 766 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
91c00924 767 else
a08abd8c 768 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924 769
91c00924
DW		 770 return tx;
771}
772
ac6b53b6
DW		 773/* set_syndrome_sources - populate source buffers for gen_syndrome
774 * @srcs - (struct page *) array of size sh->disks
775 * @sh - stripe_head to parse
776 *
777 * Populates srcs in proper layout order for the stripe and returns the
778 * 'count' of sources to be used in a call to async_gen_syndrome. The P
779 * destination buffer is recorded in srcs[count] and the Q destination
780 * is recorded in srcs[count+1]].
781 */
782static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
783{
784 int disks = sh->disks;
785 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
786 int d0_idx = raid6_d0(sh);
787 int count;
788 int i;
789
790 for (i = 0; i < disks; i++)
5dd33c9a 791 srcs[i] = NULL;
ac6b53b6
DW		 792
793 count = 0;
794 i = d0_idx;
795 do {
796 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
797
798 srcs[slot] = sh->dev[i].page;
799 i = raid6_next_disk(i, disks);
800 } while (i != d0_idx);
ac6b53b6 801
e4424fee 802 return syndrome_disks;
ac6b53b6
DW		 803}
804
805static struct dma_async_tx_descriptor *
806ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
807{
808 int disks = sh->disks;
809 struct page **blocks = percpu->scribble;
810 int target;
811 int qd_idx = sh->qd_idx;
812 struct dma_async_tx_descriptor *tx;
813 struct async_submit_ctl submit;
814 struct r5dev *tgt;
815 struct page *dest;
816 int i;
817 int count;
818
819 if (sh->ops.target < 0)
820 target = sh->ops.target2;
821 else if (sh->ops.target2 < 0)
822 target = sh->ops.target;
91c00924 823 else
ac6b53b6
DW		 824 /* we should only have one valid target */
825 BUG();
826 BUG_ON(target < 0);
827 pr_debug("%s: stripe %llu block: %d\n",
828 __func__, (unsigned long long)sh->sector, target);
829
830 tgt = &sh->dev[target];
831 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
832 dest = tgt->page;
833
834 atomic_inc(&sh->count);
835
836 if (target == qd_idx) {
837 count = set_syndrome_sources(blocks, sh);
838 blocks[count] = NULL; /* regenerating p is not necessary */
839 BUG_ON(blocks[count+1] != dest); /* q should already be set */
0403e382
DW		 840 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
841 ops_complete_compute, sh,
ac6b53b6
DW		 842 to_addr_conv(sh, percpu));
843 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
844 } else {
845 /* Compute any data- or p-drive using XOR */
846 count = 0;
847 for (i = disks; i-- ; ) {
848 if (i == target || i == qd_idx)
849 continue;
850 blocks[count++] = sh->dev[i].page;
851 }
852
0403e382
DW		 853 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
854 NULL, ops_complete_compute, sh,
ac6b53b6
DW		 855 to_addr_conv(sh, percpu));
856 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
857 }
91c00924 858
91c00924
DW		 859 return tx;
860}
861
ac6b53b6
DW		 862static struct dma_async_tx_descriptor *
863ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
864{
865 int i, count, disks = sh->disks;
866 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
867 int d0_idx = raid6_d0(sh);
868 int faila = -1, failb = -1;
869 int target = sh->ops.target;
870 int target2 = sh->ops.target2;
871 struct r5dev *tgt = &sh->dev[target];
872 struct r5dev *tgt2 = &sh->dev[target2];
873 struct dma_async_tx_descriptor *tx;
874 struct page **blocks = percpu->scribble;
875 struct async_submit_ctl submit;
876
877 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
878 __func__, (unsigned long long)sh->sector, target, target2);
879 BUG_ON(target < 0 || target2 < 0);
880 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
881 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
882
6c910a78 883 /* we need to open-code set_syndrome_sources to handle the
ac6b53b6
DW		 884 * slot number conversion for 'faila' and 'failb'
885 */
886 for (i = 0; i < disks ; i++)
5dd33c9a 887 blocks[i] = NULL;
ac6b53b6
DW		 888 count = 0;
889 i = d0_idx;
890 do {
891 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
892
893 blocks[slot] = sh->dev[i].page;
894
895 if (i == target)
896 faila = slot;
897 if (i == target2)
898 failb = slot;
899 i = raid6_next_disk(i, disks);
900 } while (i != d0_idx);
ac6b53b6
DW		 901
902 BUG_ON(faila == failb);
903 if (failb < faila)
904 swap(faila, failb);
905 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
906 __func__, (unsigned long long)sh->sector, faila, failb);
907
908 atomic_inc(&sh->count);
909
910 if (failb == syndrome_disks+1) {
911 /* Q disk is one of the missing disks */
912 if (faila == syndrome_disks) {
913 /* Missing P+Q, just recompute */
0403e382
DW		 914 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
915 ops_complete_compute, sh,
916 to_addr_conv(sh, percpu));
e4424fee 917 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
ac6b53b6
DW		 918 STRIPE_SIZE, &submit);
919 } else {
920 struct page *dest;
921 int data_target;
922 int qd_idx = sh->qd_idx;
923
924 /* Missing D+Q: recompute D from P, then recompute Q */
925 if (target == qd_idx)
926 data_target = target2;
927 else
928 data_target = target;
929
930 count = 0;
931 for (i = disks; i-- ; ) {
932 if (i == data_target || i == qd_idx)
933 continue;
934 blocks[count++] = sh->dev[i].page;
935 }
936 dest = sh->dev[data_target].page;
0403e382
DW		 937 init_async_submit(&submit,
938 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
939 NULL, NULL, NULL,
940 to_addr_conv(sh, percpu));
ac6b53b6
DW		 941 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
942 &submit);
943
944 count = set_syndrome_sources(blocks, sh);
0403e382
DW		 945 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
946 ops_complete_compute, sh,
947 to_addr_conv(sh, percpu));
ac6b53b6
DW		 948 return async_gen_syndrome(blocks, 0, count+2,
949 STRIPE_SIZE, &submit);
950 }
ac6b53b6 951 } else {
6c910a78
DW		 952 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
953 ops_complete_compute, sh,
954 to_addr_conv(sh, percpu));
955 if (failb == syndrome_disks) {
956 /* We're missing D+P. */
957 return async_raid6_datap_recov(syndrome_disks+2,
958 STRIPE_SIZE, faila,
959 blocks, &submit);
960 } else {
961 /* We're missing D+D. */
962 return async_raid6_2data_recov(syndrome_disks+2,
963 STRIPE_SIZE, faila, failb,
964 blocks, &submit);
965 }
ac6b53b6
DW		 966 }
967}
968
969
91c00924
DW		 970static void ops_complete_prexor(void *stripe_head_ref)
971{
972 struct stripe_head *sh = stripe_head_ref;
973
e46b272b 974 pr_debug("%s: stripe %llu\n", __func__,
91c00924 975 (unsigned long long)sh->sector);
91c00924
DW		 976}
977
978static struct dma_async_tx_descriptor *
d6f38f31
DW		 979ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
980 struct dma_async_tx_descriptor *tx)
91c00924 981{
91c00924 982 int disks = sh->disks;
d6f38f31 983 struct page **xor_srcs = percpu->scribble;
91c00924 984 int count = 0, pd_idx = sh->pd_idx, i;
a08abd8c 985 struct async_submit_ctl submit;
91c00924
DW		 986
987 /* existing parity data subtracted */
988 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
989
e46b272b 990 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 991 (unsigned long long)sh->sector);
992
993 for (i = disks; i--; ) {
994 struct r5dev *dev = &sh->dev[i];
995 /* Only process blocks that are known to be uptodate */
d8ee0728 996 if (test_bit(R5_Wantdrain, &dev->flags))
91c00924
DW		 997 xor_srcs[count++] = dev->page;
998 }
999
0403e382 1000 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
d6f38f31 1001 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
a08abd8c 1002 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 1003
1004 return tx;
1005}
1006
1007static struct dma_async_tx_descriptor *
d8ee0728 1008ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
91c00924
DW		 1009{
1010 int disks = sh->disks;
d8ee0728 1011 int i;
91c00924 1012
e46b272b 1013 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1014 (unsigned long long)sh->sector);
1015
1016 for (i = disks; i--; ) {
1017 struct r5dev *dev = &sh->dev[i];
1018 struct bio *chosen;
91c00924 1019
d8ee0728 1020 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
91c00924
DW		 1021 struct bio *wbi;
1022
cbe47ec5 1023 spin_lock_irq(&sh->raid_conf->device_lock);
91c00924
DW		 1024 chosen = dev->towrite;
1025 dev->towrite = NULL;
1026 BUG_ON(dev->written);
1027 wbi = dev->written = chosen;
cbe47ec5 1028 spin_unlock_irq(&sh->raid_conf->device_lock);
91c00924
DW		 1029
1030 while (wbi && wbi->bi_sector <
1031 dev->sector + STRIPE_SECTORS) {
e9c7469b
TH		 1032 if (wbi->bi_rw & REQ_FUA)
1033 set_bit(R5_WantFUA, &dev->flags);
91c00924
DW		 1034 tx = async_copy_data(1, wbi, dev->page,
1035 dev->sector, tx);
1036 wbi = r5_next_bio(wbi, dev->sector);
1037 }
1038 }
1039 }
1040
1041 return tx;
1042}
1043
ac6b53b6 1044static void ops_complete_reconstruct(void *stripe_head_ref)
91c00924
DW		 1045{
1046 struct stripe_head *sh = stripe_head_ref;
ac6b53b6
DW		 1047 int disks = sh->disks;
1048 int pd_idx = sh->pd_idx;
1049 int qd_idx = sh->qd_idx;
1050 int i;
e9c7469b 1051 bool fua = false;
91c00924 1052
e46b272b 1053 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1054 (unsigned long long)sh->sector);
1055
e9c7469b
TH		 1056 for (i = disks; i--; )
1057 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1058
91c00924
DW		 1059 for (i = disks; i--; ) {
1060 struct r5dev *dev = &sh->dev[i];
ac6b53b6 1061
e9c7469b 1062 if (dev->written || i == pd_idx || i == qd_idx) {
91c00924 1063 set_bit(R5_UPTODATE, &dev->flags);
e9c7469b
TH		 1064 if (fua)
1065 set_bit(R5_WantFUA, &dev->flags);
1066 }
91c00924
DW		 1067 }
1068
d8ee0728
DW		 1069 if (sh->reconstruct_state == reconstruct_state_drain_run)
1070 sh->reconstruct_state = reconstruct_state_drain_result;
1071 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1072 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1073 else {
1074 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1075 sh->reconstruct_state = reconstruct_state_result;
1076 }
91c00924
DW		 1077
1078 set_bit(STRIPE_HANDLE, &sh->state);
1079 release_stripe(sh);
1080}
1081
1082static void
ac6b53b6
DW		 1083ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1084 struct dma_async_tx_descriptor *tx)
91c00924 1085{
91c00924 1086 int disks = sh->disks;
d6f38f31 1087 struct page **xor_srcs = percpu->scribble;
a08abd8c 1088 struct async_submit_ctl submit;
91c00924
DW		 1089 int count = 0, pd_idx = sh->pd_idx, i;
1090 struct page *xor_dest;
d8ee0728 1091 int prexor = 0;
91c00924 1092 unsigned long flags;
91c00924 1093
e46b272b 1094 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1095 (unsigned long long)sh->sector);
1096
1097 /* check if prexor is active which means only process blocks
1098 * that are part of a read-modify-write (written)
1099 */
d8ee0728
DW		 1100 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1101 prexor = 1;
91c00924
DW		 1102 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1103 for (i = disks; i--; ) {
1104 struct r5dev *dev = &sh->dev[i];
1105 if (dev->written)
1106 xor_srcs[count++] = dev->page;
1107 }
1108 } else {
1109 xor_dest = sh->dev[pd_idx].page;
1110 for (i = disks; i--; ) {
1111 struct r5dev *dev = &sh->dev[i];
1112 if (i != pd_idx)
1113 xor_srcs[count++] = dev->page;
1114 }
1115 }
1116
91c00924
DW		 1117 /* 1/ if we prexor'd then the dest is reused as a source
1118 * 2/ if we did not prexor then we are redoing the parity
1119 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1120 * for the synchronous xor case
1121 */
88ba2aa5 1122 flags = ASYNC_TX_ACK |
91c00924
DW		 1123 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1124
1125 atomic_inc(&sh->count);
1126
ac6b53b6 1127 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
d6f38f31 1128 to_addr_conv(sh, percpu));
a08abd8c
DW		 1129 if (unlikely(count == 1))
1130 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1131 else
1132 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 1133}
1134
ac6b53b6
DW		 1135static void
1136ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1137 struct dma_async_tx_descriptor *tx)
1138{
1139 struct async_submit_ctl submit;
1140 struct page **blocks = percpu->scribble;
1141 int count;
1142
1143 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1144
1145 count = set_syndrome_sources(blocks, sh);
1146
1147 atomic_inc(&sh->count);
1148
1149 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1150 sh, to_addr_conv(sh, percpu));
1151 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
91c00924
DW		 1152}
1153
1154static void ops_complete_check(void *stripe_head_ref)
1155{
1156 struct stripe_head *sh = stripe_head_ref;
91c00924 1157
e46b272b 1158 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1159 (unsigned long long)sh->sector);
1160
ecc65c9b 1161 sh->check_state = check_state_check_result;
91c00924
DW		 1162 set_bit(STRIPE_HANDLE, &sh->state);
1163 release_stripe(sh);
1164}
1165
ac6b53b6 1166static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 1167{
91c00924 1168 int disks = sh->disks;
ac6b53b6
DW		 1169 int pd_idx = sh->pd_idx;
1170 int qd_idx = sh->qd_idx;
1171 struct page *xor_dest;
d6f38f31 1172 struct page **xor_srcs = percpu->scribble;
91c00924 1173 struct dma_async_tx_descriptor *tx;
a08abd8c 1174 struct async_submit_ctl submit;
ac6b53b6
DW		 1175 int count;
1176 int i;
91c00924 1177
e46b272b 1178 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1179 (unsigned long long)sh->sector);
1180
ac6b53b6
DW		 1181 count = 0;
1182 xor_dest = sh->dev[pd_idx].page;
1183 xor_srcs[count++] = xor_dest;
91c00924 1184 for (i = disks; i--; ) {
ac6b53b6
DW		 1185 if (i == pd_idx || i == qd_idx)
1186 continue;
1187 xor_srcs[count++] = sh->dev[i].page;
91c00924
DW		 1188 }
1189
d6f38f31
DW		 1190 init_async_submit(&submit, 0, NULL, NULL, NULL,
1191 to_addr_conv(sh, percpu));
099f53cb 1192 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
a08abd8c 1193 &sh->ops.zero_sum_result, &submit);
91c00924 1194
91c00924 1195 atomic_inc(&sh->count);
a08abd8c
DW		 1196 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1197 tx = async_trigger_callback(&submit);
91c00924
DW		 1198}
1199
ac6b53b6
DW		 1200static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1201{
1202 struct page **srcs = percpu->scribble;
1203 struct async_submit_ctl submit;
1204 int count;
1205
1206 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1207 (unsigned long long)sh->sector, checkp);
1208
1209 count = set_syndrome_sources(srcs, sh);
1210 if (!checkp)
1211 srcs[count] = NULL;
91c00924 1212
91c00924 1213 atomic_inc(&sh->count);
ac6b53b6
DW		 1214 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1215 sh, to_addr_conv(sh, percpu));
1216 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1217 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
91c00924
DW		 1218}
1219
417b8d4a 1220static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
91c00924
DW		 1221{
1222 int overlap_clear = 0, i, disks = sh->disks;
1223 struct dma_async_tx_descriptor *tx = NULL;
d6f38f31 1224 raid5_conf_t *conf = sh->raid_conf;
ac6b53b6 1225 int level = conf->level;
d6f38f31
DW		 1226 struct raid5_percpu *percpu;
1227 unsigned long cpu;
91c00924 1228
d6f38f31
DW		 1229 cpu = get_cpu();
1230 percpu = per_cpu_ptr(conf->percpu, cpu);
83de75cc 1231 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
91c00924
DW		 1232 ops_run_biofill(sh);
1233 overlap_clear++;
1234 }
1235
7b3a871e 1236 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
ac6b53b6
DW		 1237 if (level < 6)
1238 tx = ops_run_compute5(sh, percpu);
1239 else {
1240 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1241 tx = ops_run_compute6_1(sh, percpu);
1242 else
1243 tx = ops_run_compute6_2(sh, percpu);
1244 }
1245 /* terminate the chain if reconstruct is not set to be run */
1246 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
7b3a871e
DW		 1247 async_tx_ack(tx);
1248 }
91c00924 1249
600aa109 1250 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
d6f38f31 1251 tx = ops_run_prexor(sh, percpu, tx);
91c00924 1252
600aa109 1253 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
d8ee0728 1254 tx = ops_run_biodrain(sh, tx);
91c00924
DW		 1255 overlap_clear++;
1256 }
1257
ac6b53b6
DW		 1258 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1259 if (level < 6)
1260 ops_run_reconstruct5(sh, percpu, tx);
1261 else
1262 ops_run_reconstruct6(sh, percpu, tx);
1263 }
91c00924 1264
ac6b53b6
DW		 1265 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1266 if (sh->check_state == check_state_run)
1267 ops_run_check_p(sh, percpu);
1268 else if (sh->check_state == check_state_run_q)
1269 ops_run_check_pq(sh, percpu, 0);
1270 else if (sh->check_state == check_state_run_pq)
1271 ops_run_check_pq(sh, percpu, 1);
1272 else
1273 BUG();
1274 }
91c00924 1275
91c00924
DW		 1276 if (overlap_clear)
1277 for (i = disks; i--; ) {
1278 struct r5dev *dev = &sh->dev[i];
1279 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1280 wake_up(&sh->raid_conf->wait_for_overlap);
1281 }
d6f38f31 1282 put_cpu();
91c00924
DW		 1283}
1284
417b8d4a
DW		 1285#ifdef CONFIG_MULTICORE_RAID456
1286static void async_run_ops(void *param, async_cookie_t cookie)
1287{
1288 struct stripe_head *sh = param;
1289 unsigned long ops_request = sh->ops.request;
1290
1291 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
1292 wake_up(&sh->ops.wait_for_ops);
1293
1294 __raid_run_ops(sh, ops_request);
1295 release_stripe(sh);
1296}
1297
1298static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1299{
1300 /* since handle_stripe can be called outside of raid5d context
1301 * we need to ensure sh->ops.request is de-staged before another
1302 * request arrives
1303 */
1304 wait_event(sh->ops.wait_for_ops,
1305 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
1306 sh->ops.request = ops_request;
1307
1308 atomic_inc(&sh->count);
1309 async_schedule(async_run_ops, sh);
1310}
1311#else
1312#define raid_run_ops __raid_run_ops
1313#endif
1314
3f294f4f 1315static int grow_one_stripe(raid5_conf_t *conf)
1da177e4
LT		 1316{
1317 struct stripe_head *sh;
6ce32846 1318 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
3f294f4f
N		 1319 if (!sh)
1320 return 0;
6ce32846 1321
3f294f4f 1322 sh->raid_conf = conf;
417b8d4a
DW		 1323 #ifdef CONFIG_MULTICORE_RAID456
1324 init_waitqueue_head(&sh->ops.wait_for_ops);
1325 #endif
3f294f4f 1326
e4e11e38
N		 1327 if (grow_buffers(sh)) {
1328 shrink_buffers(sh);
3f294f4f
N		 1329 kmem_cache_free(conf->slab_cache, sh);
1330 return 0;
1331 }
1332 /* we just created an active stripe so... */
1333 atomic_set(&sh->count, 1);
1334 atomic_inc(&conf->active_stripes);
1335 INIT_LIST_HEAD(&sh->lru);
1336 release_stripe(sh);
1337 return 1;
1338}
1339
1340static int grow_stripes(raid5_conf_t *conf, int num)
1341{
e18b890b 1342 struct kmem_cache *sc;
5e5e3e78 1343 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1da177e4 1344
f4be6b43
N		 1345 if (conf->mddev->gendisk)
1346 sprintf(conf->cache_name[0],
1347 "raid%d-%s", conf->level, mdname(conf->mddev));
1348 else
1349 sprintf(conf->cache_name[0],
1350 "raid%d-%p", conf->level, conf->mddev);
1351 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1352
ad01c9e3
N		 1353 conf->active_name = 0;
1354 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1da177e4 1355 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
20c2df83 1356 0, 0, NULL);
1da177e4
LT		 1357 if (!sc)
1358 return 1;
1359 conf->slab_cache = sc;
ad01c9e3 1360 conf->pool_size = devs;
16a53ecc 1361 while (num--)
3f294f4f 1362 if (!grow_one_stripe(conf))
1da177e4 1363 return 1;
1da177e4
LT		 1364 return 0;
1365}
29269553 1366
d6f38f31
DW		 1367/**
1368 * scribble_len - return the required size of the scribble region
1369 * @num - total number of disks in the array
1370 *
1371 * The size must be enough to contain:
1372 * 1/ a struct page pointer for each device in the array +2
1373 * 2/ room to convert each entry in (1) to its corresponding dma
1374 * (dma_map_page()) or page (page_address()) address.
1375 *
1376 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1377 * calculate over all devices (not just the data blocks), using zeros in place
1378 * of the P and Q blocks.
1379 */
1380static size_t scribble_len(int num)
1381{
1382 size_t len;
1383
1384 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1385
1386 return len;
1387}
1388
ad01c9e3
N		 1389static int resize_stripes(raid5_conf_t *conf, int newsize)
1390{
1391 /* Make all the stripes able to hold 'newsize' devices.
1392 * New slots in each stripe get 'page' set to a new page.
1393 *
1394 * This happens in stages:
1395 * 1/ create a new kmem_cache and allocate the required number of
1396 * stripe_heads.
1397 * 2/ gather all the old stripe_heads and tranfer the pages across
1398 * to the new stripe_heads. This will have the side effect of
1399 * freezing the array as once all stripe_heads have been collected,
1400 * no IO will be possible. Old stripe heads are freed once their
1401 * pages have been transferred over, and the old kmem_cache is
1402 * freed when all stripes are done.
1403 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1404 * we simple return a failre status - no need to clean anything up.
1405 * 4/ allocate new pages for the new slots in the new stripe_heads.
1406 * If this fails, we don't bother trying the shrink the
1407 * stripe_heads down again, we just leave them as they are.
1408 * As each stripe_head is processed the new one is released into
1409 * active service.
1410 *
1411 * Once step2 is started, we cannot afford to wait for a write,
1412 * so we use GFP_NOIO allocations.
1413 */
1414 struct stripe_head *osh, *nsh;
1415 LIST_HEAD(newstripes);
1416 struct disk_info *ndisks;
d6f38f31 1417 unsigned long cpu;
b5470dc5 1418 int err;
e18b890b 1419 struct kmem_cache *sc;
ad01c9e3
N		 1420 int i;
1421
1422 if (newsize <= conf->pool_size)
1423 return 0; /* never bother to shrink */
1424
b5470dc5
DW		 1425 err = md_allow_write(conf->mddev);
1426 if (err)
1427 return err;
2a2275d6 1428
ad01c9e3
N		 1429 /* Step 1 */
1430 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1431 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
20c2df83 1432 0, 0, NULL);
ad01c9e3
N		 1433 if (!sc)
1434 return -ENOMEM;
1435
1436 for (i = conf->max_nr_stripes; i; i--) {
6ce32846 1437 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
ad01c9e3
N		 1438 if (!nsh)
1439 break;
1440
ad01c9e3 1441 nsh->raid_conf = conf;
417b8d4a
DW		 1442 #ifdef CONFIG_MULTICORE_RAID456
1443 init_waitqueue_head(&nsh->ops.wait_for_ops);
1444 #endif
ad01c9e3
N		 1445
1446 list_add(&nsh->lru, &newstripes);
1447 }
1448 if (i) {
1449 /* didn't get enough, give up */
1450 while (!list_empty(&newstripes)) {
1451 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1452 list_del(&nsh->lru);
1453 kmem_cache_free(sc, nsh);
1454 }
1455 kmem_cache_destroy(sc);
1456 return -ENOMEM;
1457 }
1458 /* Step 2 - Must use GFP_NOIO now.
1459 * OK, we have enough stripes, start collecting inactive
1460 * stripes and copying them over
1461 */
1462 list_for_each_entry(nsh, &newstripes, lru) {
1463 spin_lock_irq(&conf->device_lock);
1464 wait_event_lock_irq(conf->wait_for_stripe,
1465 !list_empty(&conf->inactive_list),
1466 conf->device_lock,
482c0834 1467 );
ad01c9e3
N		 1468 osh = get_free_stripe(conf);
1469 spin_unlock_irq(&conf->device_lock);
1470 atomic_set(&nsh->count, 1);
1471 for(i=0; i<conf->pool_size; i++)
1472 nsh->dev[i].page = osh->dev[i].page;
1473 for( ; i<newsize; i++)
1474 nsh->dev[i].page = NULL;
1475 kmem_cache_free(conf->slab_cache, osh);
1476 }
1477 kmem_cache_destroy(conf->slab_cache);
1478
1479 /* Step 3.
1480 * At this point, we are holding all the stripes so the array
1481 * is completely stalled, so now is a good time to resize
d6f38f31 1482 * conf->disks and the scribble region
ad01c9e3
N		 1483 */
1484 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1485 if (ndisks) {
1486 for (i=0; i<conf->raid_disks; i++)
1487 ndisks[i] = conf->disks[i];
1488 kfree(conf->disks);
1489 conf->disks = ndisks;
1490 } else
1491 err = -ENOMEM;
1492
d6f38f31
DW		 1493 get_online_cpus();
1494 conf->scribble_len = scribble_len(newsize);
1495 for_each_present_cpu(cpu) {
1496 struct raid5_percpu *percpu;
1497 void *scribble;
1498
1499 percpu = per_cpu_ptr(conf->percpu, cpu);
1500 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1501
1502 if (scribble) {
1503 kfree(percpu->scribble);
1504 percpu->scribble = scribble;
1505 } else {
1506 err = -ENOMEM;
1507 break;
1508 }
1509 }
1510 put_online_cpus();
1511
ad01c9e3
N		 1512 /* Step 4, return new stripes to service */
1513 while(!list_empty(&newstripes)) {
1514 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1515 list_del_init(&nsh->lru);
d6f38f31 1516
ad01c9e3
N		 1517 for (i=conf->raid_disks; i < newsize; i++)
1518 if (nsh->dev[i].page == NULL) {
1519 struct page *p = alloc_page(GFP_NOIO);
1520 nsh->dev[i].page = p;
1521 if (!p)
1522 err = -ENOMEM;
1523 }
1524 release_stripe(nsh);
1525 }
1526 /* critical section pass, GFP_NOIO no longer needed */
1527
1528 conf->slab_cache = sc;
1529 conf->active_name = 1-conf->active_name;
1530 conf->pool_size = newsize;
1531 return err;
1532}
1da177e4 1533
3f294f4f 1534static int drop_one_stripe(raid5_conf_t *conf)
1da177e4
LT		 1535{
1536 struct stripe_head *sh;
1537
3f294f4f
N		 1538 spin_lock_irq(&conf->device_lock);
1539 sh = get_free_stripe(conf);
1540 spin_unlock_irq(&conf->device_lock);
1541 if (!sh)
1542 return 0;
78bafebd 1543 BUG_ON(atomic_read(&sh->count));
e4e11e38 1544 shrink_buffers(sh);
3f294f4f
N		 1545 kmem_cache_free(conf->slab_cache, sh);
1546 atomic_dec(&conf->active_stripes);
1547 return 1;
1548}
1549
1550static void shrink_stripes(raid5_conf_t *conf)
1551{
1552 while (drop_one_stripe(conf))
1553 ;
1554
29fc7e3e
N		 1555 if (conf->slab_cache)
1556 kmem_cache_destroy(conf->slab_cache);
1da177e4
LT		 1557 conf->slab_cache = NULL;
1558}
1559
6712ecf8 1560static void raid5_end_read_request(struct bio * bi, int error)
1da177e4 1561{
99c0fb5f 1562 struct stripe_head *sh = bi->bi_private;
1da177e4 1563 raid5_conf_t *conf = sh->raid_conf;
7ecaa1e6 1564 int disks = sh->disks, i;
1da177e4 1565 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
d6950432
N		 1566 char b[BDEVNAME_SIZE];
1567 mdk_rdev_t *rdev;
1da177e4 1568
1da177e4
LT		 1569
1570 for (i=0 ; i<disks; i++)
1571 if (bi == &sh->dev[i].req)
1572 break;
1573
45b4233c
DW		 1574 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1575 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1da177e4
LT		 1576 uptodate);
1577 if (i == disks) {
1578 BUG();
6712ecf8 1579 return;
1da177e4
LT		 1580 }
1581
1582 if (uptodate) {
1da177e4 1583 set_bit(R5_UPTODATE, &sh->dev[i].flags);
4e5314b5 1584 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
d6950432 1585 rdev = conf->disks[i].rdev;
0c55e022 1586 printk_rl(KERN_INFO "md/raid:%s: read error corrected"
6be9d494
BS		 1587 " (%lu sectors at %llu on %s)\n",
1588 mdname(conf->mddev), STRIPE_SECTORS,
1589 (unsigned long long)(sh->sector
1590 + rdev->data_offset),
1591 bdevname(rdev->bdev, b));
4e5314b5
N		 1592 clear_bit(R5_ReadError, &sh->dev[i].flags);
1593 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1594 }
ba22dcbf
N		 1595 if (atomic_read(&conf->disks[i].rdev->read_errors))
1596 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1da177e4 1597 } else {
d6950432 1598 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
ba22dcbf 1599 int retry = 0;
d6950432
N		 1600 rdev = conf->disks[i].rdev;
1601
1da177e4 1602 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
d6950432 1603 atomic_inc(&rdev->read_errors);
7b0bb536 1604 if (conf->mddev->degraded >= conf->max_degraded)
6be9d494 1605 printk_rl(KERN_WARNING
0c55e022 1606 "md/raid:%s: read error not correctable "
6be9d494
BS		 1607 "(sector %llu on %s).\n",
1608 mdname(conf->mddev),
1609 (unsigned long long)(sh->sector
1610 + rdev->data_offset),
1611 bdn);
ba22dcbf 1612 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
4e5314b5 1613 /* Oh, no!!! */
6be9d494 1614 printk_rl(KERN_WARNING
0c55e022 1615 "md/raid:%s: read error NOT corrected!! "
6be9d494
BS		 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 */
911d4ee8 1759 pd_idx = qd_idx = ~0;
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
1fe797e6
DW		 2311/* fetch_block5 - checks the given member device to see if its data needs
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
2315 * 0 to tell the loop in handle_stripe_fill5 to continue
f38e1219 2316 */
1fe797e6
DW		 2317static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2318 int disk_idx, int disks)
f38e1219
DW		 2319{
2320 struct r5dev *dev = &sh->dev[disk_idx];
f2b3b44d 2321 struct r5dev *failed_dev = &sh->dev[s->failed_num[0]];
f38e1219 2322
f38e1219
DW		 2323 /* is the data in this block needed, and can we get it? */
2324 if (!test_bit(R5_LOCKED, &dev->flags) &&
1fe797e6
DW		 2325 !test_bit(R5_UPTODATE, &dev->flags) &&
2326 (dev->toread ||
2327 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2328 s->syncing || s->expanding ||
5d35e09c
N		 2329 (s->failed && failed_dev->toread) ||
2330 (s->failed && failed_dev->towrite &&
1fe797e6 2331 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
976ea8d4
DW		 2332 /* We would like to get this block, possibly by computing it,
2333 * otherwise read it if the backing disk is insync
f38e1219
DW		 2334 */
2335 if ((s->uptodate == disks - 1) &&
f2b3b44d 2336 (s->failed && disk_idx == s->failed_num[0])) {
976ea8d4
DW		 2337 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2338 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
f38e1219
DW		 2339 set_bit(R5_Wantcompute, &dev->flags);
2340 sh->ops.target = disk_idx;
ac6b53b6 2341 sh->ops.target2 = -1;
f38e1219 2342 s->req_compute = 1;
f38e1219 2343 /* Careful: from this point on 'uptodate' is in the eye
ac6b53b6 2344 * of raid_run_ops which services 'compute' operations
f38e1219
DW		 2345 * before writes. R5_Wantcompute flags a block that will
2346 * be R5_UPTODATE by the time it is needed for a
2347 * subsequent operation.
2348 */
2349 s->uptodate++;
1fe797e6 2350 return 1; /* uptodate + compute == disks */
7a1fc53c 2351 } else if (test_bit(R5_Insync, &dev->flags)) {
f38e1219
DW		 2352 set_bit(R5_LOCKED, &dev->flags);
2353 set_bit(R5_Wantread, &dev->flags);
f38e1219
DW		 2354 s->locked++;
2355 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2356 s->syncing);
2357 }
2358 }
2359
1fe797e6 2360 return 0;
f38e1219
DW		 2361}
2362
1fe797e6
DW		 2363/**
2364 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2365 */
2366static void handle_stripe_fill5(struct stripe_head *sh,
a4456856
DW		 2367 struct stripe_head_state *s, int disks)
2368{
2369 int i;
f38e1219 2370
f38e1219
DW		 2371 /* look for blocks to read/compute, skip this if a compute
2372 * is already in flight, or if the stripe contents are in the
2373 * midst of changing due to a write
2374 */
976ea8d4 2375 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
1fe797e6 2376 !sh->reconstruct_state)
f38e1219 2377 for (i = disks; i--; )
1fe797e6 2378 if (fetch_block5(sh, s, i, disks))
f38e1219 2379 break;
a4456856
DW		 2380 set_bit(STRIPE_HANDLE, &sh->state);
2381}
2382
5599becc
YT		 2383/* fetch_block6 - checks the given member device to see if its data needs
2384 * to be read or computed to satisfy a request.
2385 *
2386 * Returns 1 when no more member devices need to be checked, otherwise returns
2387 * 0 to tell the loop in handle_stripe_fill6 to continue
2388 */
2389static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
f2b3b44d 2390 int disk_idx, int disks)
a4456856 2391{
5599becc 2392 struct r5dev *dev = &sh->dev[disk_idx];
f2b3b44d
N		 2393 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
2394 &sh->dev[s->failed_num[1]] };
5599becc
YT		 2395
2396 if (!test_bit(R5_LOCKED, &dev->flags) &&
2397 !test_bit(R5_UPTODATE, &dev->flags) &&
2398 (dev->toread ||
2399 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2400 s->syncing || s->expanding ||
5d35e09c
N		 2401 (s->failed >= 1 && fdev[0]->toread) ||
2402 (s->failed >= 2 && fdev[1]->toread) ||
2403 (s->failed && s->to_write)) {
5599becc
YT		 2404 /* we would like to get this block, possibly by computing it,
2405 * otherwise read it if the backing disk is insync
2406 */
2407 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2408 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2409 if ((s->uptodate == disks - 1) &&
f2b3b44d
N		 2410 (s->failed && (disk_idx == s->failed_num[0] ||
2411 disk_idx == s->failed_num[1]))) {
5599becc
YT		 2412 /* have disk failed, and we're requested to fetch it;
2413 * do compute it
a4456856 2414 */
5599becc
YT		 2415 pr_debug("Computing stripe %llu block %d\n",
2416 (unsigned long long)sh->sector, disk_idx);
2417 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2418 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2419 set_bit(R5_Wantcompute, &dev->flags);
2420 sh->ops.target = disk_idx;
2421 sh->ops.target2 = -1; /* no 2nd target */
2422 s->req_compute = 1;
2423 s->uptodate++;
2424 return 1;
2425 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2426 /* Computing 2-failure is *very* expensive; only
2427 * do it if failed >= 2
2428 */
2429 int other;
2430 for (other = disks; other--; ) {
2431 if (other == disk_idx)
2432 continue;
2433 if (!test_bit(R5_UPTODATE,
2434 &sh->dev[other].flags))
2435 break;
a4456856 2436 }
5599becc
YT		 2437 BUG_ON(other < 0);
2438 pr_debug("Computing stripe %llu blocks %d,%d\n",
2439 (unsigned long long)sh->sector,
2440 disk_idx, other);
2441 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2442 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2443 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2444 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2445 sh->ops.target = disk_idx;
2446 sh->ops.target2 = other;
2447 s->uptodate += 2;
2448 s->req_compute = 1;
2449 return 1;
2450 } else if (test_bit(R5_Insync, &dev->flags)) {
2451 set_bit(R5_LOCKED, &dev->flags);
2452 set_bit(R5_Wantread, &dev->flags);
2453 s->locked++;
2454 pr_debug("Reading block %d (sync=%d)\n",
2455 disk_idx, s->syncing);
a4456856
DW		 2456 }
2457 }
5599becc
YT		 2458
2459 return 0;
2460}
2461
2462/**
2463 * handle_stripe_fill6 - read or compute data to satisfy pending requests.
2464 */
2465static void handle_stripe_fill6(struct stripe_head *sh,
f2b3b44d 2466 struct stripe_head_state *s,
5599becc
YT		 2467 int disks)
2468{
2469 int i;
2470
2471 /* look for blocks to read/compute, skip this if a compute
2472 * is already in flight, or if the stripe contents are in the
2473 * midst of changing due to a write
2474 */
2475 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2476 !sh->reconstruct_state)
2477 for (i = disks; i--; )
f2b3b44d 2478 if (fetch_block6(sh, s, i, disks))
5599becc 2479 break;
a4456856
DW		 2480 set_bit(STRIPE_HANDLE, &sh->state);
2481}
2482
2483
1fe797e6 2484/* handle_stripe_clean_event
a4456856
DW		 2485 * any written block on an uptodate or failed drive can be returned.
2486 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2487 * never LOCKED, so we don't need to test 'failed' directly.
2488 */
1fe797e6 2489static void handle_stripe_clean_event(raid5_conf_t *conf,
a4456856
DW		 2490 struct stripe_head *sh, int disks, struct bio **return_bi)
2491{
2492 int i;
2493 struct r5dev *dev;
2494
2495 for (i = disks; i--; )
2496 if (sh->dev[i].written) {
2497 dev = &sh->dev[i];
2498 if (!test_bit(R5_LOCKED, &dev->flags) &&
2499 test_bit(R5_UPTODATE, &dev->flags)) {
2500 /* We can return any write requests */
2501 struct bio *wbi, *wbi2;
2502 int bitmap_end = 0;
45b4233c 2503 pr_debug("Return write for disc %d\n", i);
a4456856
DW		 2504 spin_lock_irq(&conf->device_lock);
2505 wbi = dev->written;
2506 dev->written = NULL;
2507 while (wbi && wbi->bi_sector <
2508 dev->sector + STRIPE_SECTORS) {
2509 wbi2 = r5_next_bio(wbi, dev->sector);
960e739d 2510 if (!raid5_dec_bi_phys_segments(wbi)) {
a4456856
DW		 2511 md_write_end(conf->mddev);
2512 wbi->bi_next = *return_bi;
2513 *return_bi = wbi;
2514 }
2515 wbi = wbi2;
2516 }
2517 if (dev->towrite == NULL)
2518 bitmap_end = 1;
2519 spin_unlock_irq(&conf->device_lock);
2520 if (bitmap_end)
2521 bitmap_endwrite(conf->mddev->bitmap,
2522 sh->sector,
2523 STRIPE_SECTORS,
2524 !test_bit(STRIPE_DEGRADED, &sh->state),
2525 0);
2526 }
2527 }
8b3e6cdc
DW		 2528
2529 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2530 if (atomic_dec_and_test(&conf->pending_full_writes))
2531 md_wakeup_thread(conf->mddev->thread);
a4456856
DW		 2532}
2533
1fe797e6 2534static void handle_stripe_dirtying5(raid5_conf_t *conf,
a4456856
DW		 2535 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2536{
2537 int rmw = 0, rcw = 0, i;
2538 for (i = disks; i--; ) {
2539 /* would I have to read this buffer for read_modify_write */
2540 struct r5dev *dev = &sh->dev[i];
2541 if ((dev->towrite || i == sh->pd_idx) &&
2542 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2543 !(test_bit(R5_UPTODATE, &dev->flags) ||
2544 test_bit(R5_Wantcompute, &dev->flags))) {
a4456856
DW		 2545 if (test_bit(R5_Insync, &dev->flags))
2546 rmw++;
2547 else
2548 rmw += 2*disks; /* cannot read it */
2549 }
2550 /* Would I have to read this buffer for reconstruct_write */
2551 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2552 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2553 !(test_bit(R5_UPTODATE, &dev->flags) ||
2554 test_bit(R5_Wantcompute, &dev->flags))) {
2555 if (test_bit(R5_Insync, &dev->flags)) rcw++;
a4456856
DW		 2556 else
2557 rcw += 2*disks;
2558 }
2559 }
45b4233c 2560 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
a4456856
DW		 2561 (unsigned long long)sh->sector, rmw, rcw);
2562 set_bit(STRIPE_HANDLE, &sh->state);
2563 if (rmw < rcw && rmw > 0)
2564 /* prefer read-modify-write, but need to get some data */
2565 for (i = disks; i--; ) {
2566 struct r5dev *dev = &sh->dev[i];
2567 if ((dev->towrite || i == sh->pd_idx) &&
2568 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2569 !(test_bit(R5_UPTODATE, &dev->flags) ||
2570 test_bit(R5_Wantcompute, &dev->flags)) &&
a4456856
DW		 2571 test_bit(R5_Insync, &dev->flags)) {
2572 if (
2573 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 2574 pr_debug("Read_old block "
a4456856
DW		 2575 "%d for r-m-w\n", i);
2576 set_bit(R5_LOCKED, &dev->flags);
2577 set_bit(R5_Wantread, &dev->flags);
2578 s->locked++;
2579 } else {
2580 set_bit(STRIPE_DELAYED, &sh->state);
2581 set_bit(STRIPE_HANDLE, &sh->state);
2582 }
2583 }
2584 }
2585 if (rcw <= rmw && rcw > 0)
2586 /* want reconstruct write, but need to get some data */
2587 for (i = disks; i--; ) {
2588 struct r5dev *dev = &sh->dev[i];
2589 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2590 i != sh->pd_idx &&
2591 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 2592 !(test_bit(R5_UPTODATE, &dev->flags) ||
2593 test_bit(R5_Wantcompute, &dev->flags)) &&
a4456856
DW		 2594 test_bit(R5_Insync, &dev->flags)) {
2595 if (
2596 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 2597 pr_debug("Read_old block "
a4456856
DW		 2598 "%d for Reconstruct\n", i);
2599 set_bit(R5_LOCKED, &dev->flags);
2600 set_bit(R5_Wantread, &dev->flags);
2601 s->locked++;
2602 } else {
2603 set_bit(STRIPE_DELAYED, &sh->state);
2604 set_bit(STRIPE_HANDLE, &sh->state);
2605 }
2606 }
2607 }
2608 /* now if nothing is locked, and if we have enough data,
2609 * we can start a write request
2610 */
f38e1219
DW		 2611 /* since handle_stripe can be called at any time we need to handle the
2612 * case where a compute block operation has been submitted and then a
ac6b53b6
DW		 2613 * subsequent call wants to start a write request. raid_run_ops only
2614 * handles the case where compute block and reconstruct are requested
f38e1219
DW		 2615 * simultaneously. If this is not the case then new writes need to be
2616 * held off until the compute completes.
2617 */
976ea8d4
DW		 2618 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2619 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2620 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
c0f7bddb 2621 schedule_reconstruction(sh, s, rcw == 0, 0);
a4456856
DW		 2622}
2623
1fe797e6 2624static void handle_stripe_dirtying6(raid5_conf_t *conf,
a4456856 2625 struct stripe_head *sh, struct stripe_head_state *s,
f2b3b44d 2626 int disks)
a4456856 2627{
a9b39a74 2628 int rcw = 0, pd_idx = sh->pd_idx, i;
34e04e87 2629 int qd_idx = sh->qd_idx;
a9b39a74
YT		 2630
2631 set_bit(STRIPE_HANDLE, &sh->state);
a4456856
DW		 2632 for (i = disks; i--; ) {
2633 struct r5dev *dev = &sh->dev[i];
a9b39a74
YT		 2634 /* check if we haven't enough data */
2635 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2636 i != pd_idx && i != qd_idx &&
2637 !test_bit(R5_LOCKED, &dev->flags) &&
2638 !(test_bit(R5_UPTODATE, &dev->flags) ||
2639 test_bit(R5_Wantcompute, &dev->flags))) {
2640 rcw++;
2641 if (!test_bit(R5_Insync, &dev->flags))
2642 continue; /* it's a failed drive */
2643
2644 if (
2645 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2646 pr_debug("Read_old stripe %llu "
2647 "block %d for Reconstruct\n",
2648 (unsigned long long)sh->sector, i);
2649 set_bit(R5_LOCKED, &dev->flags);
2650 set_bit(R5_Wantread, &dev->flags);
2651 s->locked++;
2652 } else {
2653 pr_debug("Request delayed stripe %llu "
2654 "block %d for Reconstruct\n",
2655 (unsigned long long)sh->sector, i);
2656 set_bit(STRIPE_DELAYED, &sh->state);
2657 set_bit(STRIPE_HANDLE, &sh->state);
a4456856
DW		 2658 }
2659 }
2660 }
a4456856
DW		 2661 /* now if nothing is locked, and if we have enough data, we can start a
2662 * write request
2663 */
a9b39a74
YT		 2664 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2665 s->locked == 0 && rcw == 0 &&
a4456856 2666 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
a9b39a74 2667 schedule_reconstruction(sh, s, 1, 0);
a4456856
DW		 2668 }
2669}
2670
2671static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2672 struct stripe_head_state *s, int disks)
2673{
ecc65c9b 2674 struct r5dev *dev = NULL;
bd2ab670 2675
a4456856 2676 set_bit(STRIPE_HANDLE, &sh->state);
e89f8962 2677
ecc65c9b
DW		 2678 switch (sh->check_state) {
2679 case check_state_idle:
2680 /* start a new check operation if there are no failures */
bd2ab670 2681 if (s->failed == 0) {
bd2ab670 2682 BUG_ON(s->uptodate != disks);
ecc65c9b
DW		 2683 sh->check_state = check_state_run;
2684 set_bit(STRIPE_OP_CHECK, &s->ops_request);
bd2ab670 2685 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
bd2ab670 2686 s->uptodate--;
ecc65c9b 2687 break;
bd2ab670 2688 }
f2b3b44d 2689 dev = &sh->dev[s->failed_num[0]];
ecc65c9b
DW		 2690 /* fall through */
2691 case check_state_compute_result:
2692 sh->check_state = check_state_idle;
2693 if (!dev)
2694 dev = &sh->dev[sh->pd_idx];
2695
2696 /* check that a write has not made the stripe insync */
2697 if (test_bit(STRIPE_INSYNC, &sh->state))
2698 break;
c8894419 2699
a4456856 2700 /* either failed parity check, or recovery is happening */
a4456856
DW		 2701 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2702 BUG_ON(s->uptodate != disks);
2703
2704 set_bit(R5_LOCKED, &dev->flags);
ecc65c9b 2705 s->locked++;
a4456856 2706 set_bit(R5_Wantwrite, &dev->flags);
830ea016 2707
a4456856 2708 clear_bit(STRIPE_DEGRADED, &sh->state);
a4456856 2709 set_bit(STRIPE_INSYNC, &sh->state);
ecc65c9b
DW		 2710 break;
2711 case check_state_run:
2712 break; /* we will be called again upon completion */
2713 case check_state_check_result:
2714 sh->check_state = check_state_idle;
2715
2716 /* if a failure occurred during the check operation, leave
2717 * STRIPE_INSYNC not set and let the stripe be handled again
2718 */
2719 if (s->failed)
2720 break;
2721
2722 /* handle a successful check operation, if parity is correct
2723 * we are done. Otherwise update the mismatch count and repair
2724 * parity if !MD_RECOVERY_CHECK
2725 */
ad283ea4 2726 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
ecc65c9b
DW		 2727 /* parity is correct (on disc,
2728 * not in buffer any more)
2729 */
2730 set_bit(STRIPE_INSYNC, &sh->state);
2731 else {
2732 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2733 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2734 /* don't try to repair!! */
2735 set_bit(STRIPE_INSYNC, &sh->state);
2736 else {
2737 sh->check_state = check_state_compute_run;
976ea8d4 2738 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
ecc65c9b
DW		 2739 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2740 set_bit(R5_Wantcompute,
2741 &sh->dev[sh->pd_idx].flags);
2742 sh->ops.target = sh->pd_idx;
ac6b53b6 2743 sh->ops.target2 = -1;
ecc65c9b
DW		 2744 s->uptodate++;
2745 }
2746 }
2747 break;
2748 case check_state_compute_run:
2749 break;
2750 default:
2751 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2752 __func__, sh->check_state,
2753 (unsigned long long) sh->sector);
2754 BUG();
a4456856
DW		 2755 }
2756}
2757
2758
2759static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
36d1c647 2760 struct stripe_head_state *s,
f2b3b44d 2761 int disks)
a4456856 2762{
a4456856 2763 int pd_idx = sh->pd_idx;
34e04e87 2764 int qd_idx = sh->qd_idx;
d82dfee0 2765 struct r5dev *dev;
a4456856
DW		 2766
2767 set_bit(STRIPE_HANDLE, &sh->state);
2768
2769 BUG_ON(s->failed > 2);
d82dfee0 2770
a4456856
DW		 2771 /* Want to check and possibly repair P and Q.
2772 * However there could be one 'failed' device, in which
2773 * case we can only check one of them, possibly using the
2774 * other to generate missing data
2775 */
2776
d82dfee0
DW		 2777 switch (sh->check_state) {
2778 case check_state_idle:
2779 /* start a new check operation if there are < 2 failures */
f2b3b44d 2780 if (s->failed == s->q_failed) {
d82dfee0 2781 /* The only possible failed device holds Q, so it
a4456856
DW		 2782 * makes sense to check P (If anything else were failed,
2783 * we would have used P to recreate it).
2784 */
d82dfee0 2785 sh->check_state = check_state_run;
a4456856 2786 }
f2b3b44d 2787 if (!s->q_failed && s->failed < 2) {
d82dfee0 2788 /* Q is not failed, and we didn't use it to generate
a4456856
DW		 2789 * anything, so it makes sense to check it
2790 */
d82dfee0
DW		 2791 if (sh->check_state == check_state_run)
2792 sh->check_state = check_state_run_pq;
2793 else
2794 sh->check_state = check_state_run_q;
a4456856 2795 }
a4456856 2796
d82dfee0
DW		 2797 /* discard potentially stale zero_sum_result */
2798 sh->ops.zero_sum_result = 0;
a4456856 2799
d82dfee0
DW		 2800 if (sh->check_state == check_state_run) {
2801 /* async_xor_zero_sum destroys the contents of P */
2802 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2803 s->uptodate--;
a4456856 2804 }
d82dfee0
DW		 2805 if (sh->check_state >= check_state_run &&
2806 sh->check_state <= check_state_run_pq) {
2807 /* async_syndrome_zero_sum preserves P and Q, so
2808 * no need to mark them !uptodate here
2809 */
2810 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2811 break;
a4456856
DW		 2812 }
2813
d82dfee0
DW		 2814 /* we have 2-disk failure */
2815 BUG_ON(s->failed != 2);
2816 /* fall through */
2817 case check_state_compute_result:
2818 sh->check_state = check_state_idle;
a4456856 2819
d82dfee0
DW		 2820 /* check that a write has not made the stripe insync */
2821 if (test_bit(STRIPE_INSYNC, &sh->state))
2822 break;
a4456856
DW		 2823
2824 /* now write out any block on a failed drive,
d82dfee0 2825 * or P or Q if they were recomputed
a4456856 2826 */
d82dfee0 2827 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
a4456856 2828 if (s->failed == 2) {
f2b3b44d 2829 dev = &sh->dev[s->failed_num[1]];
a4456856
DW		 2830 s->locked++;
2831 set_bit(R5_LOCKED, &dev->flags);
2832 set_bit(R5_Wantwrite, &dev->flags);
2833 }
2834 if (s->failed >= 1) {
f2b3b44d 2835 dev = &sh->dev[s->failed_num[0]];
a4456856
DW		 2836 s->locked++;
2837 set_bit(R5_LOCKED, &dev->flags);
2838 set_bit(R5_Wantwrite, &dev->flags);
2839 }
d82dfee0 2840 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
a4456856
DW		 2841 dev = &sh->dev[pd_idx];
2842 s->locked++;
2843 set_bit(R5_LOCKED, &dev->flags);
2844 set_bit(R5_Wantwrite, &dev->flags);
2845 }
d82dfee0 2846 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
a4456856
DW		 2847 dev = &sh->dev[qd_idx];
2848 s->locked++;
2849 set_bit(R5_LOCKED, &dev->flags);
2850 set_bit(R5_Wantwrite, &dev->flags);
2851 }
2852 clear_bit(STRIPE_DEGRADED, &sh->state);
2853
2854 set_bit(STRIPE_INSYNC, &sh->state);
d82dfee0
DW		 2855 break;
2856 case check_state_run:
2857 case check_state_run_q:
2858 case check_state_run_pq:
2859 break; /* we will be called again upon completion */
2860 case check_state_check_result:
2861 sh->check_state = check_state_idle;
2862
2863 /* handle a successful check operation, if parity is correct
2864 * we are done. Otherwise update the mismatch count and repair
2865 * parity if !MD_RECOVERY_CHECK
2866 */
2867 if (sh->ops.zero_sum_result == 0) {
2868 /* both parities are correct */
2869 if (!s->failed)
2870 set_bit(STRIPE_INSYNC, &sh->state);
2871 else {
2872 /* in contrast to the raid5 case we can validate
2873 * parity, but still have a failure to write
2874 * back
2875 */
2876 sh->check_state = check_state_compute_result;
2877 /* Returning at this point means that we may go
2878 * off and bring p and/or q uptodate again so
2879 * we make sure to check zero_sum_result again
2880 * to verify if p or q need writeback
2881 */
2882 }
2883 } else {
2884 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2885 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2886 /* don't try to repair!! */
2887 set_bit(STRIPE_INSYNC, &sh->state);
2888 else {
2889 int *target = &sh->ops.target;
2890
2891 sh->ops.target = -1;
2892 sh->ops.target2 = -1;
2893 sh->check_state = check_state_compute_run;
2894 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2895 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2896 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2897 set_bit(R5_Wantcompute,
2898 &sh->dev[pd_idx].flags);
2899 *target = pd_idx;
2900 target = &sh->ops.target2;
2901 s->uptodate++;
2902 }
2903 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2904 set_bit(R5_Wantcompute,
2905 &sh->dev[qd_idx].flags);
2906 *target = qd_idx;
2907 s->uptodate++;
2908 }
2909 }
2910 }
2911 break;
2912 case check_state_compute_run:
2913 break;
2914 default:
2915 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2916 __func__, sh->check_state,
2917 (unsigned long long) sh->sector);
2918 BUG();
a4456856
DW		 2919 }
2920}
2921
86c374ba 2922static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh)
a4456856
DW		 2923{
2924 int i;
2925
2926 /* We have read all the blocks in this stripe and now we need to
2927 * copy some of them into a target stripe for expand.
2928 */
f0a50d37 2929 struct dma_async_tx_descriptor *tx = NULL;
a4456856
DW		 2930 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2931 for (i = 0; i < sh->disks; i++)
34e04e87 2932 if (i != sh->pd_idx && i != sh->qd_idx) {
911d4ee8 2933 int dd_idx, j;
a4456856 2934 struct stripe_head *sh2;
a08abd8c 2935 struct async_submit_ctl submit;
a4456856 2936
784052ec 2937 sector_t bn = compute_blocknr(sh, i, 1);
911d4ee8
N		 2938 sector_t s = raid5_compute_sector(conf, bn, 0,
2939 &dd_idx, NULL);
a8c906ca 2940 sh2 = get_active_stripe(conf, s, 0, 1, 1);
a4456856
DW		 2941 if (sh2 == NULL)
2942 /* so far only the early blocks of this stripe
2943 * have been requested. When later blocks
2944 * get requested, we will try again
2945 */
2946 continue;
2947 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2948 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2949 /* must have already done this block */
2950 release_stripe(sh2);
2951 continue;
2952 }
f0a50d37
DW		 2953
2954 /* place all the copies on one channel */
a08abd8c 2955 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
f0a50d37 2956 tx = async_memcpy(sh2->dev[dd_idx].page,
88ba2aa5 2957 sh->dev[i].page, 0, 0, STRIPE_SIZE,
a08abd8c 2958 &submit);
f0a50d37 2959
a4456856
DW		 2960 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2961 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2962 for (j = 0; j < conf->raid_disks; j++)
2963 if (j != sh2->pd_idx &&
86c374ba 2964 j != sh2->qd_idx &&
a4456856
DW		 2965 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2966 break;
2967 if (j == conf->raid_disks) {
2968 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2969 set_bit(STRIPE_HANDLE, &sh2->state);
2970 }
2971 release_stripe(sh2);
f0a50d37 2972
a4456856 2973 }
a2e08551
N		 2974 /* done submitting copies, wait for them to complete */
2975 if (tx) {
2976 async_tx_ack(tx);
2977 dma_wait_for_async_tx(tx);
2978 }
a4456856 2979}
1da177e4 2980
6bfe0b49 2981
1da177e4
LT		 2982/*
2983 * handle_stripe - do things to a stripe.
2984 *
2985 * We lock the stripe and then examine the state of various bits
2986 * to see what needs to be done.
2987 * Possible results:
2988 * return some read request which now have data
2989 * return some write requests which are safely on disc
2990 * schedule a read on some buffers
2991 * schedule a write of some buffers
2992 * return confirmation of parity correctness
2993 *
1da177e4
LT		 2994 * buffers are taken off read_list or write_list, and bh_cache buffers
2995 * get BH_Lock set before the stripe lock is released.
2996 *
2997 */
a4456856 2998
3687c061 2999static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
1da177e4
LT		 3000{
3001 raid5_conf_t *conf = sh->raid_conf;
a4456856 3002 int disks = sh->disks, i;
1da177e4 3003 struct r5dev *dev;
e0a115e5 3004 int prexor;
1da177e4 3005
83de75cc 3006 /* Now to look around and see what can be done */
9910f16a 3007 rcu_read_lock();
c4c1663b 3008 spin_lock_irq(&conf->device_lock);
1da177e4
LT		 3009 for (i=disks; i--; ) {
3010 mdk_rdev_t *rdev;
a9f326eb
N		 3011
3012 dev = &sh->dev[i];
1da177e4 3013
b5e98d65
DW		 3014 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
3015 "written %p\n", i, dev->flags, dev->toread, dev->read,
3016 dev->towrite, dev->written);
3017
3018 /* maybe we can request a biofill operation
3019 *
3020 * new wantfill requests are only permitted while
83de75cc 3021 * ops_complete_biofill is guaranteed to be inactive
b5e98d65
DW		 3022 */
3023 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
83de75cc 3024 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
b5e98d65 3025 set_bit(R5_Wantfill, &dev->flags);
1da177e4
LT		 3026
3027 /* now count some things */
cc94015a
N		 3028 if (test_bit(R5_LOCKED, &dev->flags))
3029 s->locked++;
3030 if (test_bit(R5_UPTODATE, &dev->flags))
3031 s->uptodate++;
3032 if (test_bit(R5_Wantcompute, &dev->flags))
3033 s->compute++;
1da177e4 3034
b5e98d65 3035 if (test_bit(R5_Wantfill, &dev->flags))
cc94015a 3036 s->to_fill++;
b5e98d65 3037 else if (dev->toread)
cc94015a 3038 s->to_read++;
1da177e4 3039 if (dev->towrite) {
cc94015a 3040 s->to_write++;
1da177e4 3041 if (!test_bit(R5_OVERWRITE, &dev->flags))
cc94015a 3042 s->non_overwrite++;
1da177e4 3043 }
a4456856 3044 if (dev->written)
cc94015a 3045 s->written++;
9910f16a 3046 rdev = rcu_dereference(conf->disks[i].rdev);
cc94015a 3047 if (s->blocked_rdev == NULL &&
ac4090d2 3048 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
cc94015a 3049 s->blocked_rdev = rdev;
6bfe0b49 3050 atomic_inc(&rdev->nr_pending);
6bfe0b49 3051 }
415e72d0
N		 3052 clear_bit(R5_Insync, &dev->flags);
3053 if (!rdev)
3054 /* Not in-sync */;
3055 else if (test_bit(In_sync, &rdev->flags))
3056 set_bit(R5_Insync, &dev->flags);
3057 else {
3058 /* could be in-sync depending on recovery/reshape status */
3059 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3060 set_bit(R5_Insync, &dev->flags);
3061 }
3062 if (!test_bit(R5_Insync, &dev->flags)) {
14f8d26b 3063 /* The ReadError flag will just be confusing now */
4e5314b5
N		 3064 clear_bit(R5_ReadError, &dev->flags);
3065 clear_bit(R5_ReWrite, &dev->flags);
3066 }
415e72d0
N		 3067 if (test_bit(R5_ReadError, &dev->flags))
3068 clear_bit(R5_Insync, &dev->flags);
3069 if (!test_bit(R5_Insync, &dev->flags)) {
cc94015a
N		 3070 s->failed++;
3071 s->failed_num[0] = i;
415e72d0 3072 }
1da177e4 3073 }
c4c1663b 3074 spin_unlock_irq(&conf->device_lock);
9910f16a 3075 rcu_read_unlock();
b5e98d65 3076
cc94015a
N		 3077 if (unlikely(s->blocked_rdev)) {
3078 if (s->syncing || s->expanding || s->expanded ||
3079 s->to_write || s->written) {
ac4090d2 3080 set_bit(STRIPE_HANDLE, &sh->state);
3687c061 3081 return 1;
ac4090d2
N		 3082 }
3083 /* There is nothing for the blocked_rdev to block */
cc94015a
N		 3084 rdev_dec_pending(s->blocked_rdev, conf->mddev);
3085 s->blocked_rdev = NULL;
6bfe0b49
DW		 3086 }
3087
cc94015a
N		 3088 if (s->to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3089 set_bit(STRIPE_OP_BIOFILL, &s->ops_request);
83de75cc
DW		 3090 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3091 }
b5e98d65 3092
45b4233c 3093 pr_debug("locked=%d uptodate=%d to_read=%d"
1da177e4 3094 " to_write=%d failed=%d failed_num=%d\n",
cc94015a
N		 3095 s->locked, s->uptodate, s->to_read, s->to_write,
3096 s->failed, s->failed_num[0]);
1da177e4
LT		 3097 /* check if the array has lost two devices and, if so, some requests might
3098 * need to be failed
3099 */
cc94015a
N		 3100 if (s->failed > 1 && s->to_read+s->to_write+s->written)
3101 handle_failed_stripe(conf, sh, s, disks, &s->return_bi);
3102 if (s->failed > 1 && s->syncing) {
1da177e4
LT		 3103 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3104 clear_bit(STRIPE_SYNCING, &sh->state);
cc94015a 3105 s->syncing = 0;
1da177e4
LT		 3106 }
3107
3108 /* might be able to return some write requests if the parity block
3109 * is safe, or on a failed drive
3110 */
3111 dev = &sh->dev[sh->pd_idx];
cc94015a
N		 3112 if (s->written &&
3113 ((test_bit(R5_Insync, &dev->flags) &&
3114 !test_bit(R5_LOCKED, &dev->flags) &&
3115 test_bit(R5_UPTODATE, &dev->flags)) ||
3116 (s->failed == 1 && s->failed_num[0] == sh->pd_idx)))
3117 handle_stripe_clean_event(conf, sh, disks, &s->return_bi);
1da177e4
LT		 3118
3119 /* Now we might consider reading some blocks, either to check/generate
3120 * parity, or to satisfy requests
3121 * or to load a block that is being partially written.
3122 */
cc94015a
N		 3123 if (s->to_read || s->non_overwrite ||
3124 (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)
3125 handle_stripe_fill5(sh, s, disks);
1da177e4 3126
e33129d8
DW		 3127 /* Now we check to see if any write operations have recently
3128 * completed
3129 */
e0a115e5 3130 prexor = 0;
d8ee0728 3131 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
e0a115e5 3132 prexor = 1;
d8ee0728
DW		 3133 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3134 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
600aa109 3135 sh->reconstruct_state = reconstruct_state_idle;
e33129d8
DW		 3136
3137 /* All the 'written' buffers and the parity block are ready to
3138 * be written back to disk
3139 */
3140 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3141 for (i = disks; i--; ) {
3142 dev = &sh->dev[i];
3143 if (test_bit(R5_LOCKED, &dev->flags) &&
3144 (i == sh->pd_idx || dev->written)) {
3145 pr_debug("Writing block %d\n", i);
3146 set_bit(R5_Wantwrite, &dev->flags);
e0a115e5
DW		 3147 if (prexor)
3148 continue;
e33129d8 3149 if (!test_bit(R5_Insync, &dev->flags) ||
cc94015a 3150 (i == sh->pd_idx && s->failed == 0))
e33129d8
DW		 3151 set_bit(STRIPE_INSYNC, &sh->state);
3152 }
3153 }
729a1866 3154 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
cc94015a 3155 s->dec_preread_active = 1;
e33129d8
DW		 3156 }
3157
3158 /* Now to consider new write requests and what else, if anything
3159 * should be read. We do not handle new writes when:
3160 * 1/ A 'write' operation (copy+xor) is already in flight.
3161 * 2/ A 'check' operation is in flight, as it may clobber the parity
3162 * block.
3163 */
cc94015a
N		 3164 if (s->to_write && !sh->reconstruct_state && !sh->check_state)
3165 handle_stripe_dirtying5(conf, sh, s, disks);
1da177e4
LT		 3166
3167 /* maybe we need to check and possibly fix the parity for this stripe
e89f8962
DW		 3168 * Any reads will already have been scheduled, so we just see if enough
3169 * data is available. The parity check is held off while parity
3170 * dependent operations are in flight.
1da177e4 3171 */
ecc65c9b 3172 if (sh->check_state ||
cc94015a 3173 (s->syncing && s->locked == 0 &&
976ea8d4 3174 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
ecc65c9b 3175 !test_bit(STRIPE_INSYNC, &sh->state)))
cc94015a 3176 handle_parity_checks5(conf, sh, s, disks);
3687c061 3177 return 0;
1da177e4
LT		 3178}
3179
3687c061 3180static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
1da177e4 3181{
bff61975 3182 raid5_conf_t *conf = sh->raid_conf;
f416885e 3183 int disks = sh->disks;
34e04e87 3184 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
16a53ecc 3185 struct r5dev *dev, *pdev, *qdev;
1da177e4 3186
16a53ecc 3187 /* Now to look around and see what can be done */
1da177e4
LT		 3188
3189 rcu_read_lock();
c4c1663b 3190 spin_lock_irq(&conf->device_lock);
16a53ecc
N		 3191 for (i=disks; i--; ) {
3192 mdk_rdev_t *rdev;
3193 dev = &sh->dev[i];
1da177e4 3194
45b4233c 3195 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
16a53ecc 3196 i, dev->flags, dev->toread, dev->towrite, dev->written);
6c0069c0
YT		 3197 /* maybe we can reply to a read
3198 *
3199 * new wantfill requests are only permitted while
3200 * ops_complete_biofill is guaranteed to be inactive
3201 */
3202 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3203 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3204 set_bit(R5_Wantfill, &dev->flags);
1da177e4 3205
16a53ecc 3206 /* now count some things */
cc94015a
N		 3207 if (test_bit(R5_LOCKED, &dev->flags))
3208 s->locked++;
3209 if (test_bit(R5_UPTODATE, &dev->flags))
3210 s->uptodate++;
2d6e4ecc 3211 if (test_bit(R5_Wantcompute, &dev->flags)) {
cc94015a
N		 3212 s->compute++;
3213 BUG_ON(s->compute > 2);
2d6e4ecc 3214 }
1da177e4 3215
6c0069c0 3216 if (test_bit(R5_Wantfill, &dev->flags)) {
cc94015a 3217 s->to_fill++;
6c0069c0 3218 } else if (dev->toread)
cc94015a 3219 s->to_read++;
16a53ecc 3220 if (dev->towrite) {
cc94015a 3221 s->to_write++;
16a53ecc 3222 if (!test_bit(R5_OVERWRITE, &dev->flags))
cc94015a 3223 s->non_overwrite++;
16a53ecc 3224 }
a4456856 3225 if (dev->written)
cc94015a 3226 s->written++;
16a53ecc 3227 rdev = rcu_dereference(conf->disks[i].rdev);
cc94015a 3228 if (s->blocked_rdev == NULL &&
ac4090d2 3229 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
cc94015a 3230 s->blocked_rdev = rdev;
6bfe0b49 3231 atomic_inc(&rdev->nr_pending);
6bfe0b49 3232 }
415e72d0
N		 3233 clear_bit(R5_Insync, &dev->flags);
3234 if (!rdev)
3235 /* Not in-sync */;
3236 else if (test_bit(In_sync, &rdev->flags))
3237 set_bit(R5_Insync, &dev->flags);
3238 else {
3239 /* in sync if before recovery_offset */
3240 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3241 set_bit(R5_Insync, &dev->flags);
3242 }
3243 if (!test_bit(R5_Insync, &dev->flags)) {
16a53ecc
N		 3244 /* The ReadError flag will just be confusing now */
3245 clear_bit(R5_ReadError, &dev->flags);
3246 clear_bit(R5_ReWrite, &dev->flags);
1da177e4 3247 }
415e72d0
N		 3248 if (test_bit(R5_ReadError, &dev->flags))
3249 clear_bit(R5_Insync, &dev->flags);
3250 if (!test_bit(R5_Insync, &dev->flags)) {
cc94015a
N		 3251 if (s->failed < 2)
3252 s->failed_num[s->failed] = i;
3253 s->failed++;
415e72d0 3254 }
1da177e4 3255 }
c4c1663b 3256 spin_unlock_irq(&conf->device_lock);
1da177e4 3257 rcu_read_unlock();
6bfe0b49 3258
cc94015a
N		 3259 if (unlikely(s->blocked_rdev)) {
3260 if (s->syncing || s->expanding || s->expanded ||
3261 s->to_write || s->written) {
ac4090d2 3262 set_bit(STRIPE_HANDLE, &sh->state);
3687c061 3263 return 1;
ac4090d2
N		 3264 }
3265 /* There is nothing for the blocked_rdev to block */
cc94015a
N		 3266 rdev_dec_pending(s->blocked_rdev, conf->mddev);
3267 s->blocked_rdev = NULL;
6bfe0b49 3268 }
ac4090d2 3269
cc94015a
N		 3270 if (s->to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3271 set_bit(STRIPE_OP_BIOFILL, &s->ops_request);
6c0069c0
YT		 3272 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3273 }
3274
45b4233c 3275 pr_debug("locked=%d uptodate=%d to_read=%d"
16a53ecc 3276 " to_write=%d failed=%d failed_num=%d,%d\n",
cc94015a
N		 3277 s->locked, s->uptodate, s->to_read, s->to_write, s->failed,
3278 s->failed_num[0], s->failed_num[1]);
a4456856
DW		 3279 /* check if the array has lost >2 devices and, if so, some requests
3280 * might need to be failed
16a53ecc 3281 */
cc94015a
N		 3282 if (s->failed > 2 && s->to_read+s->to_write+s->written)
3283 handle_failed_stripe(conf, sh, s, disks, &s->return_bi);
3284 if (s->failed > 2 && s->syncing) {
16a53ecc
N		 3285 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3286 clear_bit(STRIPE_SYNCING, &sh->state);
cc94015a 3287 s->syncing = 0;
16a53ecc
N		 3288 }
3289
3290 /*
3291 * might be able to return some write requests if the parity blocks
3292 * are safe, or on a failed drive
3293 */
3294 pdev = &sh->dev[pd_idx];
cc94015a
N		 3295 s->p_failed = (s->failed >= 1 && s->failed_num[0] == pd_idx)
3296 || (s->failed >= 2 && s->failed_num[1] == pd_idx);
34e04e87 3297 qdev = &sh->dev[qd_idx];
cc94015a
N		 3298 s->q_failed = (s->failed >= 1 && s->failed_num[0] == qd_idx)
3299 || (s->failed >= 2 && s->failed_num[1] == qd_idx);
a4456856 3300
cc94015a
N		 3301 if (s->written &&
3302 (s->p_failed || ((test_bit(R5_Insync, &pdev->flags)
16a53ecc 3303 && !test_bit(R5_LOCKED, &pdev->flags)
a4456856 3304 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
cc94015a 3305 (s->q_failed || ((test_bit(R5_Insync, &qdev->flags)
16a53ecc 3306 && !test_bit(R5_LOCKED, &qdev->flags)
a4456856 3307 && test_bit(R5_UPTODATE, &qdev->flags)))))
cc94015a 3308 handle_stripe_clean_event(conf, sh, disks, &s->return_bi);
16a53ecc
N		 3309
3310 /* Now we might consider reading some blocks, either to check/generate
3311 * parity, or to satisfy requests
3312 * or to load a block that is being partially written.
3313 */
cc94015a
N		 3314 if (s->to_read || s->non_overwrite || (s->to_write && s->failed) ||
3315 (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)
3316 handle_stripe_fill6(sh, s, disks);
16a53ecc 3317
6c0069c0
YT		 3318 /* Now we check to see if any write operations have recently
3319 * completed
3320 */
3321 if (sh->reconstruct_state == reconstruct_state_drain_result) {
6c0069c0
YT		 3322
3323 sh->reconstruct_state = reconstruct_state_idle;
3324 /* All the 'written' buffers and the parity blocks are ready to
3325 * be written back to disk
3326 */
3327 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3328 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
3329 for (i = disks; i--; ) {
3330 dev = &sh->dev[i];
3331 if (test_bit(R5_LOCKED, &dev->flags) &&
3332 (i == sh->pd_idx || i == qd_idx ||
3333 dev->written)) {
3334 pr_debug("Writing block %d\n", i);
3335 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3336 set_bit(R5_Wantwrite, &dev->flags);
3337 if (!test_bit(R5_Insync, &dev->flags) ||
3338 ((i == sh->pd_idx || i == qd_idx) &&
cc94015a 3339 s->failed == 0))
6c0069c0
YT		 3340 set_bit(STRIPE_INSYNC, &sh->state);
3341 }
3342 }
729a1866 3343 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
cc94015a 3344 s->dec_preread_active = 1;
6c0069c0
YT		 3345 }
3346
a9b39a74
YT		 3347 /* Now to consider new write requests and what else, if anything
3348 * should be read. We do not handle new writes when:
3349 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3350 * 2/ A 'check' operation is in flight, as it may clobber the parity
3351 * block.
3352 */
cc94015a
N		 3353 if (s->to_write && !sh->reconstruct_state && !sh->check_state)
3354 handle_stripe_dirtying6(conf, sh, s, disks);
16a53ecc
N		 3355
3356 /* maybe we need to check and possibly fix the parity for this stripe
a4456856 3357 * Any reads will already have been scheduled, so we just see if enough
6c0069c0
YT		 3358 * data is available. The parity check is held off while parity
3359 * dependent operations are in flight.
16a53ecc 3360 */
6c0069c0 3361 if (sh->check_state ||
cc94015a 3362 (s->syncing && s->locked == 0 &&
6c0069c0
YT		 3363 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3364 !test_bit(STRIPE_INSYNC, &sh->state)))
cc94015a 3365 handle_parity_checks6(conf, sh, s, disks);
3687c061 3366 return 0;
cc94015a
N		 3367}
3368
3369static void handle_stripe(struct stripe_head *sh)
3370{
3371 struct stripe_head_state s;
3687c061
N		 3372 int done;
3373 int i;
cc94015a
N		 3374 raid5_conf_t *conf = sh->raid_conf;
3375
3376 clear_bit(STRIPE_HANDLE, &sh->state);
3377 if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) {
3378 /* already being handled, ensure it gets handled
3379 * again when current action finishes */
3380 set_bit(STRIPE_HANDLE, &sh->state);
3381 return;
3382 }
3383
3384 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3385 set_bit(STRIPE_SYNCING, &sh->state);
3386 clear_bit(STRIPE_INSYNC, &sh->state);
3387 }
3388 clear_bit(STRIPE_DELAYED, &sh->state);
3389
3390 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3391 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3392 (unsigned long long)sh->sector, sh->state,
3393 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
3394 sh->check_state, sh->reconstruct_state);
3395 memset(&s, 0, sizeof(s));
3396
3397 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3398 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3399 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3400
3401 if (conf->level == 6)
3687c061 3402 done = handle_stripe6(sh, &s);
cc94015a 3403 else
3687c061
N		 3404 done = handle_stripe5(sh, &s);
3405
3406 if (done)
3407 goto finish;
c5a31000
N		 3408
3409
3410 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3411 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3412 clear_bit(STRIPE_SYNCING, &sh->state);
3413 }
3414
3415 /* If the failed drives are just a ReadError, then we might need
3416 * to progress the repair/check process
3417 */
3418 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
3419 for (i = 0; i < s.failed; i++) {
3420 struct r5dev *dev = &sh->dev[s.failed_num[i]];
3421 if (test_bit(R5_ReadError, &dev->flags)
3422 && !test_bit(R5_LOCKED, &dev->flags)
3423 && test_bit(R5_UPTODATE, &dev->flags)
3424 ) {
3425 if (!test_bit(R5_ReWrite, &dev->flags)) {
3426 set_bit(R5_Wantwrite, &dev->flags);
3427 set_bit(R5_ReWrite, &dev->flags);
3428 set_bit(R5_LOCKED, &dev->flags);
3429 s.locked++;
3430 } else {
3431 /* let's read it back */
3432 set_bit(R5_Wantread, &dev->flags);
3433 set_bit(R5_LOCKED, &dev->flags);
3434 s.locked++;
3435 }
3436 }
3437 }
3438
3439
3687c061
N		 3440 /* Finish reconstruct operations initiated by the expansion process */
3441 if (sh->reconstruct_state == reconstruct_state_result) {
3442 struct stripe_head *sh_src
3443 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3444 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
3445 /* sh cannot be written until sh_src has been read.
3446 * so arrange for sh to be delayed a little
3447 */
3448 set_bit(STRIPE_DELAYED, &sh->state);
3449 set_bit(STRIPE_HANDLE, &sh->state);
3450 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3451 &sh_src->state))
3452 atomic_inc(&conf->preread_active_stripes);
3453 release_stripe(sh_src);
3454 goto finish;
3455 }
3456 if (sh_src)
3457 release_stripe(sh_src);
3458
3459 sh->reconstruct_state = reconstruct_state_idle;
3460 clear_bit(STRIPE_EXPANDING, &sh->state);
3461 for (i = conf->raid_disks; i--; ) {
3462 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3463 set_bit(R5_LOCKED, &sh->dev[i].flags);
3464 s.locked++;
3465 }
3466 }
f416885e 3467
3687c061
N		 3468 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3469 !sh->reconstruct_state) {
3470 /* Need to write out all blocks after computing parity */
3471 sh->disks = conf->raid_disks;
3472 stripe_set_idx(sh->sector, conf, 0, sh);
3473 schedule_reconstruction(sh, &s, 1, 1);
3474 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3475 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3476 atomic_dec(&conf->reshape_stripes);
3477 wake_up(&conf->wait_for_overlap);
3478 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3479 }
3480
3481 if (s.expanding && s.locked == 0 &&
3482 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3483 handle_stripe_expansion(conf, sh);
16a53ecc 3484
3687c061 3485finish:
6bfe0b49 3486 /* wait for this device to become unblocked */
c5709ef6
N		 3487 if (unlikely(s.blocked_rdev))
3488 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);
6bfe0b49 3489
6c0069c0
YT		 3490 if (s.ops_request)
3491 raid_run_ops(sh, s.ops_request);
3492
f0e43bcd 3493 ops_run_io(sh, &s);
16a53ecc 3494
729a1866 3495
c5709ef6 3496 if (s.dec_preread_active) {
729a1866 3497 /* We delay this until after ops_run_io so that if make_request
e9c7469b 3498 * is waiting on a flush, it won't continue until the writes
729a1866
N		 3499 * have actually been submitted.
3500 */
3501 atomic_dec(&conf->preread_active_stripes);
3502 if (atomic_read(&conf->preread_active_stripes) <
3503 IO_THRESHOLD)
3504 md_wakeup_thread(conf->mddev->thread);
3505 }
3506
c5709ef6 3507 return_io(s.return_bi);
16a53ecc 3508
c4c1663b 3509 clear_bit(STRIPE_ACTIVE, &sh->state);
16a53ecc
N		 3510}
3511
16a53ecc
N		 3512static void raid5_activate_delayed(raid5_conf_t *conf)
3513{
3514 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3515 while (!list_empty(&conf->delayed_list)) {
3516 struct list_head *l = conf->delayed_list.next;
3517 struct stripe_head *sh;
3518 sh = list_entry(l, struct stripe_head, lru);
3519 list_del_init(l);
3520 clear_bit(STRIPE_DELAYED, &sh->state);
3521 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3522 atomic_inc(&conf->preread_active_stripes);
8b3e6cdc 3523 list_add_tail(&sh->lru, &conf->hold_list);
16a53ecc 3524 }
482c0834 3525 }
16a53ecc
N		 3526}
3527
3528static void activate_bit_delay(raid5_conf_t *conf)
3529{
3530 /* device_lock is held */
3531 struct list_head head;
3532 list_add(&head, &conf->bitmap_list);
3533 list_del_init(&conf->bitmap_list);
3534 while (!list_empty(&head)) {
3535 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3536 list_del_init(&sh->lru);
3537 atomic_inc(&sh->count);
3538 __release_stripe(conf, sh);
3539 }
3540}
3541
11d8a6e3 3542int md_raid5_congested(mddev_t *mddev, int bits)
f022b2fd 3543{
070ec55d 3544 raid5_conf_t *conf = mddev->private;
f022b2fd
N		 3545
3546 /* No difference between reads and writes. Just check
3547 * how busy the stripe_cache is
3548 */
3fa841d7 3549
f022b2fd
N		 3550 if (conf->inactive_blocked)
3551 return 1;
3552 if (conf->quiesce)
3553 return 1;
3554 if (list_empty_careful(&conf->inactive_list))
3555 return 1;
3556
3557 return 0;
3558}
11d8a6e3
N		 3559EXPORT_SYMBOL_GPL(md_raid5_congested);
3560
3561static int raid5_congested(void *data, int bits)
3562{
3563 mddev_t *mddev = data;
3564
3565 return mddev_congested(mddev, bits) ||
3566 md_raid5_congested(mddev, bits);
3567}
f022b2fd 3568
23032a0e
RBJ		 3569/* We want read requests to align with chunks where possible,
3570 * but write requests don't need to.
3571 */
cc371e66
AK		 3572static int raid5_mergeable_bvec(struct request_queue *q,
3573 struct bvec_merge_data *bvm,
3574 struct bio_vec *biovec)
23032a0e
RBJ		 3575{
3576 mddev_t *mddev = q->queuedata;
cc371e66 3577 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
23032a0e 3578 int max;
9d8f0363 3579 unsigned int chunk_sectors = mddev->chunk_sectors;
cc371e66 3580 unsigned int bio_sectors = bvm->bi_size >> 9;
23032a0e 3581
cc371e66 3582 if ((bvm->bi_rw & 1) == WRITE)
23032a0e
RBJ		 3583 return biovec->bv_len; /* always allow writes to be mergeable */
3584
664e7c41
AN		 3585 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3586 chunk_sectors = mddev->new_chunk_sectors;
23032a0e
RBJ		 3587 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3588 if (max < 0) max = 0;
3589 if (max <= biovec->bv_len && bio_sectors == 0)
3590 return biovec->bv_len;
3591 else
3592 return max;
3593}
3594
f679623f
RBJ		 3595
3596static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3597{
3598 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
9d8f0363 3599 unsigned int chunk_sectors = mddev->chunk_sectors;
f679623f
RBJ		 3600 unsigned int bio_sectors = bio->bi_size >> 9;
3601
664e7c41
AN		 3602 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3603 chunk_sectors = mddev->new_chunk_sectors;
f679623f
RBJ		 3604 return chunk_sectors >=
3605 ((sector & (chunk_sectors - 1)) + bio_sectors);
3606}
3607
46031f9a
RBJ		 3608/*
3609 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3610 * later sampled by raid5d.
3611 */
3612static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3613{
3614 unsigned long flags;
3615
3616 spin_lock_irqsave(&conf->device_lock, flags);
3617
3618 bi->bi_next = conf->retry_read_aligned_list;
3619 conf->retry_read_aligned_list = bi;
3620
3621 spin_unlock_irqrestore(&conf->device_lock, flags);
3622 md_wakeup_thread(conf->mddev->thread);
3623}
3624
3625
3626static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3627{
3628 struct bio *bi;
3629
3630 bi = conf->retry_read_aligned;
3631 if (bi) {
3632 conf->retry_read_aligned = NULL;
3633 return bi;
3634 }
3635 bi = conf->retry_read_aligned_list;
3636 if(bi) {
387bb173 3637 conf->retry_read_aligned_list = bi->bi_next;
46031f9a 3638 bi->bi_next = NULL;
960e739d
JA		 3639 /*
3640 * this sets the active strip count to 1 and the processed
3641 * strip count to zero (upper 8 bits)
3642 */
46031f9a 3643 bi->bi_phys_segments = 1; /* biased count of active stripes */
46031f9a
RBJ		 3644 }
3645
3646 return bi;
3647}
3648
3649
f679623f
RBJ		 3650/*
3651 * The "raid5_align_endio" should check if the read succeeded and if it
3652 * did, call bio_endio on the original bio (having bio_put the new bio
3653 * first).
3654 * If the read failed..
3655 */
6712ecf8 3656static void raid5_align_endio(struct bio *bi, int error)
f679623f
RBJ		 3657{
3658 struct bio* raid_bi = bi->bi_private;
46031f9a
RBJ		 3659 mddev_t *mddev;
3660 raid5_conf_t *conf;
3661 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3662 mdk_rdev_t *rdev;
3663
f679623f 3664 bio_put(bi);
46031f9a 3665
46031f9a
RBJ		 3666 rdev = (void*)raid_bi->bi_next;
3667 raid_bi->bi_next = NULL;
2b7f2228
N		 3668 mddev = rdev->mddev;
3669 conf = mddev->private;
46031f9a
RBJ		 3670
3671 rdev_dec_pending(rdev, conf->mddev);
3672
3673 if (!error && uptodate) {
6712ecf8 3674 bio_endio(raid_bi, 0);
46031f9a
RBJ		 3675 if (atomic_dec_and_test(&conf->active_aligned_reads))
3676 wake_up(&conf->wait_for_stripe);
6712ecf8 3677 return;
46031f9a
RBJ		 3678 }
3679
3680
45b4233c 3681 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
46031f9a
RBJ		 3682
3683 add_bio_to_retry(raid_bi, conf);
f679623f
RBJ		 3684}
3685
387bb173
NB		 3686static int bio_fits_rdev(struct bio *bi)
3687{
165125e1 3688 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
387bb173 3689
ae03bf63 3690 if ((bi->bi_size>>9) > queue_max_sectors(q))
387bb173
NB		 3691 return 0;
3692 blk_recount_segments(q, bi);
8a78362c 3693 if (bi->bi_phys_segments > queue_max_segments(q))
387bb173
NB		 3694 return 0;
3695
3696 if (q->merge_bvec_fn)
3697 /* it's too hard to apply the merge_bvec_fn at this stage,
3698 * just just give up
3699 */
3700 return 0;
3701
3702 return 1;
3703}
3704
3705
21a52c6d 3706static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
f679623f 3707{
070ec55d 3708 raid5_conf_t *conf = mddev->private;
8553fe7e 3709 int dd_idx;
f679623f
RBJ		 3710 struct bio* align_bi;
3711 mdk_rdev_t *rdev;
3712
3713 if (!in_chunk_boundary(mddev, raid_bio)) {
45b4233c 3714 pr_debug("chunk_aligned_read : non aligned\n");
f679623f
RBJ		 3715 return 0;
3716 }
3717 /*
a167f663 3718 * use bio_clone_mddev to make a copy of the bio
f679623f 3719 */
a167f663 3720 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
f679623f
RBJ		 3721 if (!align_bi)
3722 return 0;
3723 /*
3724 * set bi_end_io to a new function, and set bi_private to the
3725 * original bio.
3726 */
3727 align_bi->bi_end_io = raid5_align_endio;
3728 align_bi->bi_private = raid_bio;
3729 /*
3730 * compute position
3731 */
112bf897
N		 3732 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3733 0,
911d4ee8 3734 &dd_idx, NULL);
f679623f
RBJ		 3735
3736 rcu_read_lock();
3737 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3738 if (rdev && test_bit(In_sync, &rdev->flags)) {
f679623f
RBJ		 3739 atomic_inc(&rdev->nr_pending);
3740 rcu_read_unlock();
46031f9a
RBJ		 3741 raid_bio->bi_next = (void*)rdev;
3742 align_bi->bi_bdev = rdev->bdev;
3743 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3744 align_bi->bi_sector += rdev->data_offset;
3745
387bb173
NB		 3746 if (!bio_fits_rdev(align_bi)) {
3747 /* too big in some way */
3748 bio_put(align_bi);
3749 rdev_dec_pending(rdev, mddev);
3750 return 0;
3751 }
3752
46031f9a
RBJ		 3753 spin_lock_irq(&conf->device_lock);
3754 wait_event_lock_irq(conf->wait_for_stripe,
3755 conf->quiesce == 0,
3756 conf->device_lock, /* nothing */);
3757 atomic_inc(&conf->active_aligned_reads);
3758 spin_unlock_irq(&conf->device_lock);
3759
f679623f
RBJ		 3760 generic_make_request(align_bi);
3761 return 1;
3762 } else {
3763 rcu_read_unlock();
46031f9a 3764 bio_put(align_bi);
f679623f
RBJ		 3765 return 0;
3766 }
3767}
3768
8b3e6cdc
DW		 3769/* __get_priority_stripe - get the next stripe to process
3770 *
3771 * Full stripe writes are allowed to pass preread active stripes up until
3772 * the bypass_threshold is exceeded. In general the bypass_count
3773 * increments when the handle_list is handled before the hold_list; however, it
3774 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3775 * stripe with in flight i/o. The bypass_count will be reset when the
3776 * head of the hold_list has changed, i.e. the head was promoted to the
3777 * handle_list.
3778 */
3779static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3780{
3781 struct stripe_head *sh;
3782
3783 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3784 __func__,
3785 list_empty(&conf->handle_list) ? "empty" : "busy",
3786 list_empty(&conf->hold_list) ? "empty" : "busy",
3787 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3788
3789 if (!list_empty(&conf->handle_list)) {
3790 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3791
3792 if (list_empty(&conf->hold_list))
3793 conf->bypass_count = 0;
3794 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3795 if (conf->hold_list.next == conf->last_hold)
3796 conf->bypass_count++;
3797 else {
3798 conf->last_hold = conf->hold_list.next;
3799 conf->bypass_count -= conf->bypass_threshold;
3800 if (conf->bypass_count < 0)
3801 conf->bypass_count = 0;
3802 }
3803 }
3804 } else if (!list_empty(&conf->hold_list) &&
3805 ((conf->bypass_threshold &&
3806 conf->bypass_count > conf->bypass_threshold) ||
3807 atomic_read(&conf->pending_full_writes) == 0)) {
3808 sh = list_entry(conf->hold_list.next,
3809 typeof(*sh), lru);
3810 conf->bypass_count -= conf->bypass_threshold;
3811 if (conf->bypass_count < 0)
3812 conf->bypass_count = 0;
3813 } else
3814 return NULL;
3815
3816 list_del_init(&sh->lru);
3817 atomic_inc(&sh->count);
3818 BUG_ON(atomic_read(&sh->count) != 1);
3819 return sh;
3820}
f679623f 3821
21a52c6d 3822static int make_request(mddev_t *mddev, struct bio * bi)
1da177e4 3823{
070ec55d 3824 raid5_conf_t *conf = mddev->private;
911d4ee8 3825 int dd_idx;
1da177e4
LT		 3826 sector_t new_sector;
3827 sector_t logical_sector, last_sector;
3828 struct stripe_head *sh;
a362357b 3829 const int rw = bio_data_dir(bi);
49077326 3830 int remaining;
7c13edc8 3831 int plugged;
1da177e4 3832
e9c7469b
TH		 3833 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
3834 md_flush_request(mddev, bi);
e5dcdd80
N		 3835 return 0;
3836 }
3837
3d310eb7 3838 md_write_start(mddev, bi);
06d91a5f 3839
802ba064 3840 if (rw == READ &&
52488615 3841 mddev->reshape_position == MaxSector &&
21a52c6d 3842 chunk_aligned_read(mddev,bi))
99c0fb5f 3843 return 0;
52488615 3844
1da177e4
LT		 3845 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3846 last_sector = bi->bi_sector + (bi->bi_size>>9);
3847 bi->bi_next = NULL;
3848 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
06d91a5f 3849
7c13edc8 3850 plugged = mddev_check_plugged(mddev);
1da177e4
LT		 3851 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3852 DEFINE_WAIT(w);
16a53ecc 3853 int disks, data_disks;
b5663ba4 3854 int previous;
b578d55f 3855
7ecaa1e6 3856 retry:
b5663ba4 3857 previous = 0;
b0f9ec04 3858 disks = conf->raid_disks;
b578d55f 3859 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
b0f9ec04 3860 if (unlikely(conf->reshape_progress != MaxSector)) {
fef9c61f 3861 /* spinlock is needed as reshape_progress may be
df8e7f76
N		 3862 * 64bit on a 32bit platform, and so it might be
3863 * possible to see a half-updated value
aeb878b0 3864 * Of course reshape_progress could change after
df8e7f76
N		 3865 * the lock is dropped, so once we get a reference
3866 * to the stripe that we think it is, we will have
3867 * to check again.
3868 */
7ecaa1e6 3869 spin_lock_irq(&conf->device_lock);
fef9c61f
N		 3870 if (mddev->delta_disks < 0
3871 ? logical_sector < conf->reshape_progress
3872 : logical_sector >= conf->reshape_progress) {
7ecaa1e6 3873 disks = conf->previous_raid_disks;
b5663ba4
N		 3874 previous = 1;
3875 } else {
fef9c61f
N		 3876 if (mddev->delta_disks < 0
3877 ? logical_sector < conf->reshape_safe
3878 : logical_sector >= conf->reshape_safe) {
b578d55f
N		 3879 spin_unlock_irq(&conf->device_lock);
3880 schedule();
3881 goto retry;
3882 }
3883 }
7ecaa1e6
N		 3884 spin_unlock_irq(&conf->device_lock);
3885 }
16a53ecc
N		 3886 data_disks = disks - conf->max_degraded;
3887
112bf897
N		 3888 new_sector = raid5_compute_sector(conf, logical_sector,
3889 previous,
911d4ee8 3890 &dd_idx, NULL);
0c55e022 3891 pr_debug("raid456: make_request, sector %llu logical %llu\n",
1da177e4
LT		 3892 (unsigned long long)new_sector,
3893 (unsigned long long)logical_sector);
3894
b5663ba4 3895 sh = get_active_stripe(conf, new_sector, previous,
a8c906ca 3896 (bi->bi_rw&RWA_MASK), 0);
1da177e4 3897 if (sh) {
b0f9ec04 3898 if (unlikely(previous)) {
7ecaa1e6 3899 /* expansion might have moved on while waiting for a
df8e7f76
N		 3900 * stripe, so we must do the range check again.
3901 * Expansion could still move past after this
3902 * test, but as we are holding a reference to
3903 * 'sh', we know that if that happens,
3904 * STRIPE_EXPANDING will get set and the expansion
3905 * won't proceed until we finish with the stripe.
7ecaa1e6
N		 3906 */
3907 int must_retry = 0;
3908 spin_lock_irq(&conf->device_lock);
b0f9ec04
N		 3909 if (mddev->delta_disks < 0
3910 ? logical_sector >= conf->reshape_progress
3911 : logical_sector < conf->reshape_progress)
7ecaa1e6
N		 3912 /* mismatch, need to try again */
3913 must_retry = 1;
3914 spin_unlock_irq(&conf->device_lock);
3915 if (must_retry) {
3916 release_stripe(sh);
7a3ab908 3917 schedule();
7ecaa1e6
N		 3918 goto retry;
3919 }
3920 }
e62e58a5 3921
ffd96e35 3922 if (rw == WRITE &&
a5c308d4 3923 logical_sector >= mddev->suspend_lo &&
e464eafd
N		 3924 logical_sector < mddev->suspend_hi) {
3925 release_stripe(sh);
e62e58a5
N		 3926 /* As the suspend_* range is controlled by
3927 * userspace, we want an interruptible
3928 * wait.
3929 */
3930 flush_signals(current);
3931 prepare_to_wait(&conf->wait_for_overlap,
3932 &w, TASK_INTERRUPTIBLE);
3933 if (logical_sector >= mddev->suspend_lo &&
3934 logical_sector < mddev->suspend_hi)
3935 schedule();
e464eafd
N		 3936 goto retry;
3937 }
7ecaa1e6
N		 3938
3939 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
ffd96e35 3940 !add_stripe_bio(sh, bi, dd_idx, rw)) {
7ecaa1e6
N		 3941 /* Stripe is busy expanding or
3942 * add failed due to overlap. Flush everything
1da177e4
LT		 3943 * and wait a while
3944 */
482c0834 3945 md_wakeup_thread(mddev->thread);
1da177e4
LT		 3946 release_stripe(sh);
3947 schedule();
3948 goto retry;
3949 }
3950 finish_wait(&conf->wait_for_overlap, &w);
6ed3003c
N		 3951 set_bit(STRIPE_HANDLE, &sh->state);
3952 clear_bit(STRIPE_DELAYED, &sh->state);
e9c7469b 3953 if ((bi->bi_rw & REQ_SYNC) &&
729a1866
N		 3954 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3955 atomic_inc(&conf->preread_active_stripes);
1da177e4 3956 release_stripe(sh);
1da177e4
LT		 3957 } else {
3958 /* cannot get stripe for read-ahead, just give-up */
3959 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3960 finish_wait(&conf->wait_for_overlap, &w);
3961 break;
3962 }
3963
3964 }
7c13edc8
N		 3965 if (!plugged)
3966 md_wakeup_thread(mddev->thread);
3967
1da177e4 3968 spin_lock_irq(&conf->device_lock);
960e739d 3969 remaining = raid5_dec_bi_phys_segments(bi);
f6344757
N		 3970 spin_unlock_irq(&conf->device_lock);
3971 if (remaining == 0) {
1da177e4 3972
16a53ecc 3973 if ( rw == WRITE )
1da177e4 3974 md_write_end(mddev);
6712ecf8 3975
0e13fe23 3976 bio_endio(bi, 0);
1da177e4 3977 }
729a1866 3978
1da177e4
LT		 3979 return 0;
3980}
3981
b522adcd
DW		 3982static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
3983
52c03291 3984static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
1da177e4 3985{
52c03291
N		 3986 /* reshaping is quite different to recovery/resync so it is
3987 * handled quite separately ... here.
3988 *
3989 * On each call to sync_request, we gather one chunk worth of
3990 * destination stripes and flag them as expanding.
3991 * Then we find all the source stripes and request reads.
3992 * As the reads complete, handle_stripe will copy the data
3993 * into the destination stripe and release that stripe.
3994 */
7b92813c 3995 raid5_conf_t *conf = mddev->private;
1da177e4 3996 struct stripe_head *sh;
ccfcc3c1 3997 sector_t first_sector, last_sector;
f416885e
N		 3998 int raid_disks = conf->previous_raid_disks;
3999 int data_disks = raid_disks - conf->max_degraded;
4000 int new_data_disks = conf->raid_disks - conf->max_degraded;
52c03291
N		 4001 int i;
4002 int dd_idx;
c8f517c4 4003 sector_t writepos, readpos, safepos;
ec32a2bd 4004 sector_t stripe_addr;
7a661381 4005 int reshape_sectors;
ab69ae12 4006 struct list_head stripes;
52c03291 4007
fef9c61f
N		 4008 if (sector_nr == 0) {
4009 /* If restarting in the middle, skip the initial sectors */
4010 if (mddev->delta_disks < 0 &&
4011 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4012 sector_nr = raid5_size(mddev, 0, 0)
4013 - conf->reshape_progress;
a639755c 4014 } else if (mddev->delta_disks >= 0 &&
fef9c61f
N		 4015 conf->reshape_progress > 0)
4016 sector_nr = conf->reshape_progress;
f416885e 4017 sector_div(sector_nr, new_data_disks);
fef9c61f 4018 if (sector_nr) {
8dee7211
N		 4019 mddev->curr_resync_completed = sector_nr;
4020 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
fef9c61f
N		 4021 *skipped = 1;
4022 return sector_nr;
4023 }
52c03291
N		 4024 }
4025
7a661381
N		 4026 /* We need to process a full chunk at a time.
4027 * If old and new chunk sizes differ, we need to process the
4028 * largest of these
4029 */
664e7c41
AN		 4030 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4031 reshape_sectors = mddev->new_chunk_sectors;
7a661381 4032 else
9d8f0363 4033 reshape_sectors = mddev->chunk_sectors;
7a661381 4034
52c03291
N		 4035 /* we update the metadata when there is more than 3Meg
4036 * in the block range (that is rather arbitrary, should
4037 * probably be time based) or when the data about to be
4038 * copied would over-write the source of the data at
4039 * the front of the range.
fef9c61f
N		 4040 * i.e. one new_stripe along from reshape_progress new_maps
4041 * to after where reshape_safe old_maps to
52c03291 4042 */
fef9c61f 4043 writepos = conf->reshape_progress;
f416885e 4044 sector_div(writepos, new_data_disks);
c8f517c4
N		 4045 readpos = conf->reshape_progress;
4046 sector_div(readpos, data_disks);
fef9c61f 4047 safepos = conf->reshape_safe;
f416885e 4048 sector_div(safepos, data_disks);
fef9c61f 4049 if (mddev->delta_disks < 0) {
ed37d83e 4050 writepos -= min_t(sector_t, reshape_sectors, writepos);
c8f517c4 4051 readpos += reshape_sectors;
7a661381 4052 safepos += reshape_sectors;
fef9c61f 4053 } else {
7a661381 4054 writepos += reshape_sectors;
ed37d83e
N		 4055 readpos -= min_t(sector_t, reshape_sectors, readpos);
4056 safepos -= min_t(sector_t, reshape_sectors, safepos);
fef9c61f 4057 }
52c03291 4058
c8f517c4
N		 4059 /* 'writepos' is the most advanced device address we might write.
4060 * 'readpos' is the least advanced device address we might read.
4061 * 'safepos' is the least address recorded in the metadata as having
4062 * been reshaped.
4063 * If 'readpos' is behind 'writepos', then there is no way that we can
4064 * ensure safety in the face of a crash - that must be done by userspace
4065 * making a backup of the data. So in that case there is no particular
4066 * rush to update metadata.
4067 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4068 * update the metadata to advance 'safepos' to match 'readpos' so that
4069 * we can be safe in the event of a crash.
4070 * So we insist on updating metadata if safepos is behind writepos and
4071 * readpos is beyond writepos.
4072 * In any case, update the metadata every 10 seconds.
4073 * Maybe that number should be configurable, but I'm not sure it is
4074 * worth it.... maybe it could be a multiple of safemode_delay???
4075 */
fef9c61f 4076 if ((mddev->delta_disks < 0
c8f517c4
N		 4077 ? (safepos > writepos && readpos < writepos)
4078 : (safepos < writepos && readpos > writepos)) ||
4079 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
52c03291
N		 4080 /* Cannot proceed until we've updated the superblock... */
4081 wait_event(conf->wait_for_overlap,
4082 atomic_read(&conf->reshape_stripes)==0);
fef9c61f 4083 mddev->reshape_position = conf->reshape_progress;
75d3da43 4084 mddev->curr_resync_completed = sector_nr;
c8f517c4 4085 conf->reshape_checkpoint = jiffies;
850b2b42 4086 set_bit(MD_CHANGE_DEVS, &mddev->flags);
52c03291 4087 md_wakeup_thread(mddev->thread);
850b2b42 4088 wait_event(mddev->sb_wait, mddev->flags == 0 ||
52c03291
N		 4089 kthread_should_stop());
4090 spin_lock_irq(&conf->device_lock);
fef9c61f 4091 conf->reshape_safe = mddev->reshape_position;
52c03291
N		 4092 spin_unlock_irq(&conf->device_lock);
4093 wake_up(&conf->wait_for_overlap);
acb180b0 4094 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
52c03291
N		 4095 }
4096
ec32a2bd
N		 4097 if (mddev->delta_disks < 0) {
4098 BUG_ON(conf->reshape_progress == 0);
4099 stripe_addr = writepos;
4100 BUG_ON((mddev->dev_sectors &
7a661381
N		 4101 ~((sector_t)reshape_sectors - 1))
4102 - reshape_sectors - stripe_addr
ec32a2bd
N		 4103 != sector_nr);
4104 } else {
7a661381 4105 BUG_ON(writepos != sector_nr + reshape_sectors);
ec32a2bd
N		 4106 stripe_addr = sector_nr;
4107 }
ab69ae12 4108 INIT_LIST_HEAD(&stripes);
7a661381 4109 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
52c03291 4110 int j;
a9f326eb 4111 int skipped_disk = 0;
a8c906ca 4112 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
52c03291
N		 4113 set_bit(STRIPE_EXPANDING, &sh->state);
4114 atomic_inc(&conf->reshape_stripes);
4115 /* If any of this stripe is beyond the end of the old
4116 * array, then we need to zero those blocks
4117 */
4118 for (j=sh->disks; j--;) {
4119 sector_t s;
4120 if (j == sh->pd_idx)
4121 continue;
f416885e 4122 if (conf->level == 6 &&
d0dabf7e 4123 j == sh->qd_idx)
f416885e 4124 continue;
784052ec 4125 s = compute_blocknr(sh, j, 0);
b522adcd 4126 if (s < raid5_size(mddev, 0, 0)) {
a9f326eb 4127 skipped_disk = 1;
52c03291
N		 4128 continue;
4129 }
4130 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4131 set_bit(R5_Expanded, &sh->dev[j].flags);
4132 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4133 }
a9f326eb 4134 if (!skipped_disk) {
52c03291
N		 4135 set_bit(STRIPE_EXPAND_READY, &sh->state);
4136 set_bit(STRIPE_HANDLE, &sh->state);
4137 }
ab69ae12 4138 list_add(&sh->lru, &stripes);
52c03291
N		 4139 }
4140 spin_lock_irq(&conf->device_lock);
fef9c61f 4141 if (mddev->delta_disks < 0)
7a661381 4142 conf->reshape_progress -= reshape_sectors * new_data_disks;
fef9c61f 4143 else
7a661381 4144 conf->reshape_progress += reshape_sectors * new_data_disks;
52c03291
N		 4145 spin_unlock_irq(&conf->device_lock);
4146 /* Ok, those stripe are ready. We can start scheduling
4147 * reads on the source stripes.
4148 * The source stripes are determined by mapping the first and last
4149 * block on the destination stripes.
4150 */
52c03291 4151 first_sector =
ec32a2bd 4152 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
911d4ee8 4153 1, &dd_idx, NULL);
52c03291 4154 last_sector =
0e6e0271 4155 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
09c9e5fa 4156 * new_data_disks - 1),
911d4ee8 4157 1, &dd_idx, NULL);
58c0fed4
AN		 4158 if (last_sector >= mddev->dev_sectors)
4159 last_sector = mddev->dev_sectors - 1;
52c03291 4160 while (first_sector <= last_sector) {
a8c906ca 4161 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
52c03291
N		 4162 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4163 set_bit(STRIPE_HANDLE, &sh->state);
4164 release_stripe(sh);
4165 first_sector += STRIPE_SECTORS;
4166 }
ab69ae12
N		 4167 /* Now that the sources are clearly marked, we can release
4168 * the destination stripes
4169 */
4170 while (!list_empty(&stripes)) {
4171 sh = list_entry(stripes.next, struct stripe_head, lru);
4172 list_del_init(&sh->lru);
4173 release_stripe(sh);
4174 }
c6207277
N		 4175 /* If this takes us to the resync_max point where we have to pause,
4176 * then we need to write out the superblock.
4177 */
7a661381 4178 sector_nr += reshape_sectors;
c03f6a19
N		 4179 if ((sector_nr - mddev->curr_resync_completed) * 2
4180 >= mddev->resync_max - mddev->curr_resync_completed) {
c6207277
N		 4181 /* Cannot proceed until we've updated the superblock... */
4182 wait_event(conf->wait_for_overlap,
4183 atomic_read(&conf->reshape_stripes) == 0);
fef9c61f 4184 mddev->reshape_position = conf->reshape_progress;
75d3da43 4185 mddev->curr_resync_completed = sector_nr;
c8f517c4 4186 conf->reshape_checkpoint = jiffies;
c6207277
N		 4187 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4188 md_wakeup_thread(mddev->thread);
4189 wait_event(mddev->sb_wait,
4190 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4191 || kthread_should_stop());
4192 spin_lock_irq(&conf->device_lock);
fef9c61f 4193 conf->reshape_safe = mddev->reshape_position;
c6207277
N		 4194 spin_unlock_irq(&conf->device_lock);
4195 wake_up(&conf->wait_for_overlap);
acb180b0 4196 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
c6207277 4197 }
7a661381 4198 return reshape_sectors;
52c03291
N		 4199}
4200
4201/* FIXME go_faster isn't used */
4202static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
4203{
7b92813c 4204 raid5_conf_t *conf = mddev->private;
52c03291 4205 struct stripe_head *sh;
58c0fed4 4206 sector_t max_sector = mddev->dev_sectors;
57dab0bd 4207 sector_t sync_blocks;
16a53ecc
N		 4208 int still_degraded = 0;
4209 int i;
1da177e4 4210
72626685 4211 if (sector_nr >= max_sector) {
1da177e4 4212 /* just being told to finish up .. nothing much to do */
cea9c228 4213
29269553
N		 4214 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4215 end_reshape(conf);
4216 return 0;
4217 }
72626685
N		 4218
4219 if (mddev->curr_resync < max_sector) /* aborted */
4220 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4221 &sync_blocks, 1);
16a53ecc 4222 else /* completed sync */
72626685
N		 4223 conf->fullsync = 0;
4224 bitmap_close_sync(mddev->bitmap);
4225
1da177e4
LT		 4226 return 0;
4227 }
ccfcc3c1 4228
64bd660b
N		 4229 /* Allow raid5_quiesce to complete */
4230 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4231
52c03291
N		 4232 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4233 return reshape_request(mddev, sector_nr, skipped);
f6705578 4234
c6207277
N		 4235 /* No need to check resync_max as we never do more than one
4236 * stripe, and as resync_max will always be on a chunk boundary,
4237 * if the check in md_do_sync didn't fire, there is no chance
4238 * of overstepping resync_max here
4239 */
4240
16a53ecc 4241 /* if there is too many failed drives and we are trying
1da177e4
LT		 4242 * to resync, then assert that we are finished, because there is
4243 * nothing we can do.
4244 */
3285edf1 4245 if (mddev->degraded >= conf->max_degraded &&
16a53ecc 4246 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
58c0fed4 4247 sector_t rv = mddev->dev_sectors - sector_nr;
57afd89f 4248 *skipped = 1;
1da177e4
LT		 4249 return rv;
4250 }
72626685 4251 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
3855ad9f 4252 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
72626685
N		 4253 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4254 /* we can skip this block, and probably more */
4255 sync_blocks /= STRIPE_SECTORS;
4256 *skipped = 1;
4257 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4258 }
1da177e4 4259
b47490c9
N		 4260
4261 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4262
a8c906ca 4263 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
1da177e4 4264 if (sh == NULL) {
a8c906ca 4265 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
1da177e4 4266 /* make sure we don't swamp the stripe cache if someone else
16a53ecc 4267 * is trying to get access
1da177e4 4268 */
66c006a5 4269 schedule_timeout_uninterruptible(1);
1da177e4 4270 }
16a53ecc
N		 4271 /* Need to check if array will still be degraded after recovery/resync
4272 * We don't need to check the 'failed' flag as when that gets set,
4273 * recovery aborts.
4274 */
f001a70c 4275 for (i = 0; i < conf->raid_disks; i++)
16a53ecc
N		 4276 if (conf->disks[i].rdev == NULL)
4277 still_degraded = 1;
4278
4279 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4280
83206d66 4281 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
1da177e4 4282
1442577b 4283 handle_stripe(sh);
1da177e4
LT		 4284 release_stripe(sh);
4285
4286 return STRIPE_SECTORS;
4287}
4288
46031f9a
RBJ		 4289static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4290{
4291 /* We may not be able to submit a whole bio at once as there
4292 * may not be enough stripe_heads available.
4293 * We cannot pre-allocate enough stripe_heads as we may need
4294 * more than exist in the cache (if we allow ever large chunks).
4295 * So we do one stripe head at a time and record in
4296 * ->bi_hw_segments how many have been done.
4297 *
4298 * We *know* that this entire raid_bio is in one chunk, so
4299 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4300 */
4301 struct stripe_head *sh;
911d4ee8 4302 int dd_idx;
46031f9a
RBJ		 4303 sector_t sector, logical_sector, last_sector;
4304 int scnt = 0;
4305 int remaining;
4306 int handled = 0;
4307
4308 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
112bf897 4309 sector = raid5_compute_sector(conf, logical_sector,
911d4ee8 4310 0, &dd_idx, NULL);
46031f9a
RBJ		 4311 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4312
4313 for (; logical_sector < last_sector;
387bb173
NB		 4314 logical_sector += STRIPE_SECTORS,
4315 sector += STRIPE_SECTORS,
4316 scnt++) {
46031f9a 4317
960e739d 4318 if (scnt < raid5_bi_hw_segments(raid_bio))
46031f9a
RBJ		 4319 /* already done this stripe */
4320 continue;
4321
a8c906ca 4322 sh = get_active_stripe(conf, sector, 0, 1, 0);
46031f9a
RBJ		 4323
4324 if (!sh) {
4325 /* failed to get a stripe - must wait */
960e739d 4326 raid5_set_bi_hw_segments(raid_bio, scnt);
46031f9a
RBJ		 4327 conf->retry_read_aligned = raid_bio;
4328 return handled;
4329 }
4330
4331 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
387bb173
NB		 4332 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4333 release_stripe(sh);
960e739d 4334 raid5_set_bi_hw_segments(raid_bio, scnt);
387bb173
NB		 4335 conf->retry_read_aligned = raid_bio;
4336 return handled;
4337 }
4338
36d1c647 4339 handle_stripe(sh);
46031f9a
RBJ		 4340 release_stripe(sh);
4341 handled++;
4342 }
4343 spin_lock_irq(&conf->device_lock);
960e739d 4344 remaining = raid5_dec_bi_phys_segments(raid_bio);
46031f9a 4345 spin_unlock_irq(&conf->device_lock);
0e13fe23
NB		 4346 if (remaining == 0)
4347 bio_endio(raid_bio, 0);
46031f9a
RBJ		 4348 if (atomic_dec_and_test(&conf->active_aligned_reads))
4349 wake_up(&conf->wait_for_stripe);
4350 return handled;
4351}
4352
46031f9a 4353
1da177e4
LT		 4354/*
4355 * This is our raid5 kernel thread.
4356 *
4357 * We scan the hash table for stripes which can be handled now.
4358 * During the scan, completed stripes are saved for us by the interrupt
4359 * handler, so that they will not have to wait for our next wakeup.
4360 */
6ed3003c 4361static void raid5d(mddev_t *mddev)
1da177e4
LT		 4362{
4363 struct stripe_head *sh;
070ec55d 4364 raid5_conf_t *conf = mddev->private;
1da177e4 4365 int handled;
e1dfa0a2 4366 struct blk_plug plug;
1da177e4 4367
45b4233c 4368 pr_debug("+++ raid5d active\n");
1da177e4
LT		 4369
4370 md_check_recovery(mddev);
1da177e4 4371
e1dfa0a2 4372 blk_start_plug(&plug);
1da177e4
LT		 4373 handled = 0;
4374 spin_lock_irq(&conf->device_lock);
4375 while (1) {
46031f9a 4376 struct bio *bio;
1da177e4 4377
7c13edc8
N		 4378 if (atomic_read(&mddev->plug_cnt) == 0 &&
4379 !list_empty(&conf->bitmap_list)) {
4380 /* Now is a good time to flush some bitmap updates */
4381 conf->seq_flush++;
700e432d 4382 spin_unlock_irq(&conf->device_lock);
72626685 4383 bitmap_unplug(mddev->bitmap);
700e432d 4384 spin_lock_irq(&conf->device_lock);
7c13edc8 4385 conf->seq_write = conf->seq_flush;
72626685
N		 4386 activate_bit_delay(conf);
4387 }
7c13edc8
N		 4388 if (atomic_read(&mddev->plug_cnt) == 0)
4389 raid5_activate_delayed(conf);
72626685 4390
46031f9a
RBJ		 4391 while ((bio = remove_bio_from_retry(conf))) {
4392 int ok;
4393 spin_unlock_irq(&conf->device_lock);
4394 ok = retry_aligned_read(conf, bio);
4395 spin_lock_irq(&conf->device_lock);
4396 if (!ok)
4397 break;
4398 handled++;
4399 }
4400
8b3e6cdc
DW		 4401 sh = __get_priority_stripe(conf);
4402
c9f21aaf 4403 if (!sh)
1da177e4 4404 break;
1da177e4
LT		 4405 spin_unlock_irq(&conf->device_lock);
4406
4407 handled++;
417b8d4a
DW		 4408 handle_stripe(sh);
4409 release_stripe(sh);
4410 cond_resched();
1da177e4
LT		 4411
4412 spin_lock_irq(&conf->device_lock);
4413 }
45b4233c 4414 pr_debug("%d stripes handled\n", handled);
1da177e4
LT		 4415
4416 spin_unlock_irq(&conf->device_lock);
4417
c9f21aaf 4418 async_tx_issue_pending_all();
e1dfa0a2 4419 blk_finish_plug(&plug);
1da177e4 4420
45b4233c 4421 pr_debug("--- raid5d inactive\n");
1da177e4
LT		 4422}
4423
3f294f4f 4424static ssize_t
007583c9 4425raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
3f294f4f 4426{
070ec55d 4427 raid5_conf_t *conf = mddev->private;
96de1e66
N		 4428 if (conf)
4429 return sprintf(page, "%d\n", conf->max_nr_stripes);
4430 else
4431 return 0;
3f294f4f
N		 4432}
4433
c41d4ac4
N		 4434int
4435raid5_set_cache_size(mddev_t *mddev, int size)
3f294f4f 4436{
070ec55d 4437 raid5_conf_t *conf = mddev->private;
b5470dc5
DW		 4438 int err;
4439
c41d4ac4 4440 if (size <= 16 || size > 32768)
3f294f4f 4441 return -EINVAL;
c41d4ac4 4442 while (size < conf->max_nr_stripes) {
3f294f4f
N		 4443 if (drop_one_stripe(conf))
4444 conf->max_nr_stripes--;
4445 else
4446 break;
4447 }
b5470dc5
DW		 4448 err = md_allow_write(mddev);
4449 if (err)
4450 return err;
c41d4ac4 4451 while (size > conf->max_nr_stripes) {
3f294f4f
N		 4452 if (grow_one_stripe(conf))
4453 conf->max_nr_stripes++;
4454 else break;
4455 }
c41d4ac4
N		 4456 return 0;
4457}
4458EXPORT_SYMBOL(raid5_set_cache_size);
4459
4460static ssize_t
4461raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
4462{
4463 raid5_conf_t *conf = mddev->private;
4464 unsigned long new;
4465 int err;
4466
4467 if (len >= PAGE_SIZE)
4468 return -EINVAL;
4469 if (!conf)
4470 return -ENODEV;
4471
4472 if (strict_strtoul(page, 10, &new))
4473 return -EINVAL;
4474 err = raid5_set_cache_size(mddev, new);
4475 if (err)
4476 return err;
3f294f4f
N		 4477 return len;
4478}
007583c9 4479
96de1e66
N		 4480static struct md_sysfs_entry
4481raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4482 raid5_show_stripe_cache_size,
4483 raid5_store_stripe_cache_size);
3f294f4f 4484
8b3e6cdc
DW		 4485static ssize_t
4486raid5_show_preread_threshold(mddev_t *mddev, char *page)
4487{
070ec55d 4488 raid5_conf_t *conf = mddev->private;
8b3e6cdc
DW		 4489 if (conf)
4490 return sprintf(page, "%d\n", conf->bypass_threshold);
4491 else
4492 return 0;
4493}
4494
4495static ssize_t
4496raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4497{
070ec55d 4498 raid5_conf_t *conf = mddev->private;
4ef197d8 4499 unsigned long new;
8b3e6cdc
DW		 4500 if (len >= PAGE_SIZE)
4501 return -EINVAL;
4502 if (!conf)
4503 return -ENODEV;
4504
4ef197d8 4505 if (strict_strtoul(page, 10, &new))
8b3e6cdc 4506 return -EINVAL;
4ef197d8 4507 if (new > conf->max_nr_stripes)
8b3e6cdc
DW		 4508 return -EINVAL;
4509 conf->bypass_threshold = new;
4510 return len;
4511}
4512
4513static struct md_sysfs_entry
4514raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4515 S_IRUGO | S_IWUSR,
4516 raid5_show_preread_threshold,
4517 raid5_store_preread_threshold);
4518
3f294f4f 4519static ssize_t
96de1e66 4520stripe_cache_active_show(mddev_t *mddev, char *page)
3f294f4f 4521{
070ec55d 4522 raid5_conf_t *conf = mddev->private;
96de1e66
N		 4523 if (conf)
4524 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4525 else
4526 return 0;
3f294f4f
N		 4527}
4528
96de1e66
N		 4529static struct md_sysfs_entry
4530raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
3f294f4f 4531
007583c9 4532static struct attribute *raid5_attrs[] = {
3f294f4f
N		 4533 &raid5_stripecache_size.attr,
4534 &raid5_stripecache_active.attr,
8b3e6cdc 4535 &raid5_preread_bypass_threshold.attr,
3f294f4f
N		 4536 NULL,
4537};
007583c9
N		 4538static struct attribute_group raid5_attrs_group = {
4539 .name = NULL,
4540 .attrs = raid5_attrs,
3f294f4f
N		 4541};
4542
80c3a6ce
DW		 4543static sector_t
4544raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4545{
070ec55d 4546 raid5_conf_t *conf = mddev->private;
80c3a6ce
DW		 4547
4548 if (!sectors)
4549 sectors = mddev->dev_sectors;
5e5e3e78 4550 if (!raid_disks)
7ec05478 4551 /* size is defined by the smallest of previous and new size */
5e5e3e78 4552 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
80c3a6ce 4553
9d8f0363 4554 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
664e7c41 4555 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
80c3a6ce
DW		 4556 return sectors * (raid_disks - conf->max_degraded);
4557}
4558
36d1c647
DW		 4559static void raid5_free_percpu(raid5_conf_t *conf)
4560{
4561 struct raid5_percpu *percpu;
4562 unsigned long cpu;
4563
4564 if (!conf->percpu)
4565 return;
4566
4567 get_online_cpus();
4568 for_each_possible_cpu(cpu) {
4569 percpu = per_cpu_ptr(conf->percpu, cpu);
4570 safe_put_page(percpu->spare_page);
d6f38f31 4571 kfree(percpu->scribble);
36d1c647
DW		 4572 }
4573#ifdef CONFIG_HOTPLUG_CPU
4574 unregister_cpu_notifier(&conf->cpu_notify);
4575#endif
4576 put_online_cpus();
4577
4578 free_percpu(conf->percpu);
4579}
4580
95fc17aa
DW		 4581static void free_conf(raid5_conf_t *conf)
4582{
4583 shrink_stripes(conf);
36d1c647 4584 raid5_free_percpu(conf);
95fc17aa
DW		 4585 kfree(conf->disks);
4586 kfree(conf->stripe_hashtbl);
4587 kfree(conf);
4588}
4589
36d1c647
DW		 4590#ifdef CONFIG_HOTPLUG_CPU
4591static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
4592 void *hcpu)
4593{
4594 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify);
4595 long cpu = (long)hcpu;
4596 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
4597
4598 switch (action) {
4599 case CPU_UP_PREPARE:
4600 case CPU_UP_PREPARE_FROZEN:
d6f38f31 4601 if (conf->level == 6 && !percpu->spare_page)
36d1c647 4602 percpu->spare_page = alloc_page(GFP_KERNEL);
d6f38f31
DW		 4603 if (!percpu->scribble)
4604 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4605
4606 if (!percpu->scribble ||
4607 (conf->level == 6 && !percpu->spare_page)) {
4608 safe_put_page(percpu->spare_page);
4609 kfree(percpu->scribble);
36d1c647
DW		 4610 pr_err("%s: failed memory allocation for cpu%ld\n",
4611 __func__, cpu);
55af6bb5 4612 return notifier_from_errno(-ENOMEM);
36d1c647
DW		 4613 }
4614 break;
4615 case CPU_DEAD:
4616 case CPU_DEAD_FROZEN:
4617 safe_put_page(percpu->spare_page);
d6f38f31 4618 kfree(percpu->scribble);
36d1c647 4619 percpu->spare_page = NULL;
d6f38f31 4620 percpu->scribble = NULL;
36d1c647
DW		 4621 break;
4622 default:
4623 break;
4624 }
4625 return NOTIFY_OK;
4626}
4627#endif
4628
4629static int raid5_alloc_percpu(raid5_conf_t *conf)
4630{
4631 unsigned long cpu;
4632 struct page *spare_page;
a29d8b8e 4633 struct raid5_percpu __percpu *allcpus;
d6f38f31 4634 void *scribble;
36d1c647
DW		 4635 int err;
4636
36d1c647
DW		 4637 allcpus = alloc_percpu(struct raid5_percpu);
4638 if (!allcpus)
4639 return -ENOMEM;
4640 conf->percpu = allcpus;
4641
4642 get_online_cpus();
4643 err = 0;
4644 for_each_present_cpu(cpu) {
d6f38f31
DW		 4645 if (conf->level == 6) {
4646 spare_page = alloc_page(GFP_KERNEL);
4647 if (!spare_page) {
4648 err = -ENOMEM;
4649 break;
4650 }
4651 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
4652 }
5e5e3e78 4653 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
d6f38f31 4654 if (!scribble) {
36d1c647
DW		 4655 err = -ENOMEM;
4656 break;
4657 }
d6f38f31 4658 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
36d1c647
DW		 4659 }
4660#ifdef CONFIG_HOTPLUG_CPU
4661 conf->cpu_notify.notifier_call = raid456_cpu_notify;
4662 conf->cpu_notify.priority = 0;
4663 if (err == 0)
4664 err = register_cpu_notifier(&conf->cpu_notify);
4665#endif
4666 put_online_cpus();
4667
4668 return err;
4669}
4670
91adb564 4671static raid5_conf_t *setup_conf(mddev_t *mddev)
1da177e4
LT		 4672{
4673 raid5_conf_t *conf;
5e5e3e78 4674 int raid_disk, memory, max_disks;
1da177e4
LT		 4675 mdk_rdev_t *rdev;
4676 struct disk_info *disk;
1da177e4 4677
91adb564
N		 4678 if (mddev->new_level != 5
4679 && mddev->new_level != 4
4680 && mddev->new_level != 6) {
0c55e022 4681 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
91adb564
N		 4682 mdname(mddev), mddev->new_level);
4683 return ERR_PTR(-EIO);
1da177e4 4684 }
91adb564
N		 4685 if ((mddev->new_level == 5
4686 && !algorithm_valid_raid5(mddev->new_layout)) ||
4687 (mddev->new_level == 6
4688 && !algorithm_valid_raid6(mddev->new_layout))) {
0c55e022 4689 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
91adb564
N		 4690 mdname(mddev), mddev->new_layout);
4691 return ERR_PTR(-EIO);
99c0fb5f 4692 }
91adb564 4693 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
0c55e022 4694 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
91adb564
N		 4695 mdname(mddev), mddev->raid_disks);
4696 return ERR_PTR(-EINVAL);
4bbf3771
N		 4697 }
4698
664e7c41
AN		 4699 if (!mddev->new_chunk_sectors ||
4700 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4701 !is_power_of_2(mddev->new_chunk_sectors)) {
0c55e022
N		 4702 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
4703 mdname(mddev), mddev->new_chunk_sectors << 9);
91adb564 4704 return ERR_PTR(-EINVAL);
f6705578
N		 4705 }
4706
91adb564
N		 4707 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4708 if (conf == NULL)
1da177e4 4709 goto abort;
f5efd45a
DW		 4710 spin_lock_init(&conf->device_lock);
4711 init_waitqueue_head(&conf->wait_for_stripe);
4712 init_waitqueue_head(&conf->wait_for_overlap);
4713 INIT_LIST_HEAD(&conf->handle_list);
4714 INIT_LIST_HEAD(&conf->hold_list);
4715 INIT_LIST_HEAD(&conf->delayed_list);
4716 INIT_LIST_HEAD(&conf->bitmap_list);
4717 INIT_LIST_HEAD(&conf->inactive_list);
4718 atomic_set(&conf->active_stripes, 0);
4719 atomic_set(&conf->preread_active_stripes, 0);
4720 atomic_set(&conf->active_aligned_reads, 0);
4721 conf->bypass_threshold = BYPASS_THRESHOLD;
91adb564
N		 4722
4723 conf->raid_disks = mddev->raid_disks;
4724 if (mddev->reshape_position == MaxSector)
4725 conf->previous_raid_disks = mddev->raid_disks;
4726 else
f6705578 4727 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
5e5e3e78
N		 4728 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
4729 conf->scribble_len = scribble_len(max_disks);
f6705578 4730
5e5e3e78 4731 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
b55e6bfc
N		 4732 GFP_KERNEL);
4733 if (!conf->disks)
4734 goto abort;
9ffae0cf 4735
1da177e4
LT		 4736 conf->mddev = mddev;
4737
fccddba0 4738 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
1da177e4 4739 goto abort;
1da177e4 4740
36d1c647
DW		 4741 conf->level = mddev->new_level;
4742 if (raid5_alloc_percpu(conf) != 0)
4743 goto abort;
4744
0c55e022 4745 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
1da177e4 4746
159ec1fc 4747 list_for_each_entry(rdev, &mddev->disks, same_set) {
1da177e4 4748 raid_disk = rdev->raid_disk;
5e5e3e78 4749 if (raid_disk >= max_disks
1da177e4
LT		 4750 || raid_disk < 0)
4751 continue;
4752 disk = conf->disks + raid_disk;
4753
4754 disk->rdev = rdev;
4755
b2d444d7 4756 if (test_bit(In_sync, &rdev->flags)) {
1da177e4 4757 char b[BDEVNAME_SIZE];
0c55e022
N		 4758 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
4759 " disk %d\n",
4760 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
d6b212f4 4761 } else if (rdev->saved_raid_disk != raid_disk)
8c2e870a
NB		 4762 /* Cannot rely on bitmap to complete recovery */
4763 conf->fullsync = 1;
1da177e4
LT		 4764 }
4765
09c9e5fa 4766 conf->chunk_sectors = mddev->new_chunk_sectors;
91adb564 4767 conf->level = mddev->new_level;
16a53ecc
N		 4768 if (conf->level == 6)
4769 conf->max_degraded = 2;
4770 else
4771 conf->max_degraded = 1;
91adb564 4772 conf->algorithm = mddev->new_layout;
1da177e4 4773 conf->max_nr_stripes = NR_STRIPES;
fef9c61f 4774 conf->reshape_progress = mddev->reshape_position;
e183eaed 4775 if (conf->reshape_progress != MaxSector) {
09c9e5fa 4776 conf->prev_chunk_sectors = mddev->chunk_sectors;
e183eaed
N		 4777 conf->prev_algo = mddev->layout;
4778 }
1da177e4 4779
91adb564 4780 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
5e5e3e78 4781 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
91adb564
N		 4782 if (grow_stripes(conf, conf->max_nr_stripes)) {
4783 printk(KERN_ERR
0c55e022
N		 4784 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4785 mdname(mddev), memory);
91adb564
N		 4786 goto abort;
4787 } else
0c55e022
N		 4788 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
4789 mdname(mddev), memory);
1da177e4 4790
0da3c619 4791 conf->thread = md_register_thread(raid5d, mddev, NULL);
91adb564
N		 4792 if (!conf->thread) {
4793 printk(KERN_ERR
0c55e022 4794 "md/raid:%s: couldn't allocate thread.\n",
91adb564 4795 mdname(mddev));
16a53ecc
N		 4796 goto abort;
4797 }
91adb564
N		 4798
4799 return conf;
4800
4801 abort:
4802 if (conf) {
95fc17aa 4803 free_conf(conf);
91adb564
N		 4804 return ERR_PTR(-EIO);
4805 } else
4806 return ERR_PTR(-ENOMEM);
4807}
4808
c148ffdc
N		 4809
4810static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
4811{
4812 switch (algo) {
4813 case ALGORITHM_PARITY_0:
4814 if (raid_disk < max_degraded)
4815 return 1;
4816 break;
4817 case ALGORITHM_PARITY_N:
4818 if (raid_disk >= raid_disks - max_degraded)
4819 return 1;
4820 break;
4821 case ALGORITHM_PARITY_0_6:
4822 if (raid_disk == 0 ||
4823 raid_disk == raid_disks - 1)
4824 return 1;
4825 break;
4826 case ALGORITHM_LEFT_ASYMMETRIC_6:
4827 case ALGORITHM_RIGHT_ASYMMETRIC_6:
4828 case ALGORITHM_LEFT_SYMMETRIC_6:
4829 case ALGORITHM_RIGHT_SYMMETRIC_6:
4830 if (raid_disk == raid_disks - 1)
4831 return 1;
4832 }
4833 return 0;
4834}
4835
91adb564
N		 4836static int run(mddev_t *mddev)
4837{
4838 raid5_conf_t *conf;
9f7c2220 4839 int working_disks = 0;
c148ffdc 4840 int dirty_parity_disks = 0;
91adb564 4841 mdk_rdev_t *rdev;
c148ffdc 4842 sector_t reshape_offset = 0;
91adb564 4843
8c6ac868 4844 if (mddev->recovery_cp != MaxSector)
0c55e022 4845 printk(KERN_NOTICE "md/raid:%s: not clean"
8c6ac868
AN		 4846 " -- starting background reconstruction\n",
4847 mdname(mddev));
91adb564
N		 4848 if (mddev->reshape_position != MaxSector) {
4849 /* Check that we can continue the reshape.
4850 * Currently only disks can change, it must
4851 * increase, and we must be past the point where
4852 * a stripe over-writes itself
4853 */
4854 sector_t here_new, here_old;
4855 int old_disks;
18b00334 4856 int max_degraded = (mddev->level == 6 ? 2 : 1);
91adb564 4857
88ce4930 4858 if (mddev->new_level != mddev->level) {
0c55e022 4859 printk(KERN_ERR "md/raid:%s: unsupported reshape "
91adb564
N		 4860 "required - aborting.\n",
4861 mdname(mddev));
4862 return -EINVAL;
4863 }
91adb564
N		 4864 old_disks = mddev->raid_disks - mddev->delta_disks;
4865 /* reshape_position must be on a new-stripe boundary, and one
4866 * further up in new geometry must map after here in old
4867 * geometry.
4868 */
4869 here_new = mddev->reshape_position;
664e7c41 4870 if (sector_div(here_new, mddev->new_chunk_sectors *
91adb564 4871 (mddev->raid_disks - max_degraded))) {
0c55e022
N		 4872 printk(KERN_ERR "md/raid:%s: reshape_position not "
4873 "on a stripe boundary\n", mdname(mddev));
91adb564
N		 4874 return -EINVAL;
4875 }
c148ffdc 4876 reshape_offset = here_new * mddev->new_chunk_sectors;
91adb564
N		 4877 /* here_new is the stripe we will write to */
4878 here_old = mddev->reshape_position;
9d8f0363 4879 sector_div(here_old, mddev->chunk_sectors *
91adb564
N		 4880 (old_disks-max_degraded));
4881 /* here_old is the first stripe that we might need to read
4882 * from */
67ac6011
N		 4883 if (mddev->delta_disks == 0) {
4884 /* We cannot be sure it is safe to start an in-place
4885 * reshape. It is only safe if user-space if monitoring
4886 * and taking constant backups.
4887 * mdadm always starts a situation like this in
4888 * readonly mode so it can take control before
4889 * allowing any writes. So just check for that.
4890 */
4891 if ((here_new * mddev->new_chunk_sectors !=
4892 here_old * mddev->chunk_sectors) ||
4893 mddev->ro == 0) {
0c55e022
N		 4894 printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
4895 " in read-only mode - aborting\n",
4896 mdname(mddev));
67ac6011
N		 4897 return -EINVAL;
4898 }
4899 } else if (mddev->delta_disks < 0
4900 ? (here_new * mddev->new_chunk_sectors <=
4901 here_old * mddev->chunk_sectors)
4902 : (here_new * mddev->new_chunk_sectors >=
4903 here_old * mddev->chunk_sectors)) {
91adb564 4904 /* Reading from the same stripe as writing to - bad */
0c55e022
N		 4905 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
4906 "auto-recovery - aborting.\n",
4907 mdname(mddev));
91adb564
N		 4908 return -EINVAL;
4909 }
0c55e022
N		 4910 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
4911 mdname(mddev));
91adb564
N		 4912 /* OK, we should be able to continue; */
4913 } else {
4914 BUG_ON(mddev->level != mddev->new_level);
4915 BUG_ON(mddev->layout != mddev->new_layout);
664e7c41 4916 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
91adb564 4917 BUG_ON(mddev->delta_disks != 0);
1da177e4 4918 }
91adb564 4919
245f46c2
N		 4920 if (mddev->private == NULL)
4921 conf = setup_conf(mddev);
4922 else
4923 conf = mddev->private;
4924
91adb564
N		 4925 if (IS_ERR(conf))
4926 return PTR_ERR(conf);
4927
4928 mddev->thread = conf->thread;
4929 conf->thread = NULL;
4930 mddev->private = conf;
4931
4932 /*
4933 * 0 for a fully functional array, 1 or 2 for a degraded array.
4934 */
c148ffdc
N		 4935 list_for_each_entry(rdev, &mddev->disks, same_set) {
4936 if (rdev->raid_disk < 0)
4937 continue;
2f115882 4938 if (test_bit(In_sync, &rdev->flags)) {
91adb564 4939 working_disks++;
2f115882
N		 4940 continue;
4941 }
c148ffdc
N		 4942 /* This disc is not fully in-sync. However if it
4943 * just stored parity (beyond the recovery_offset),
4944 * when we don't need to be concerned about the
4945 * array being dirty.
4946 * When reshape goes 'backwards', we never have
4947 * partially completed devices, so we only need
4948 * to worry about reshape going forwards.
4949 */
4950 /* Hack because v0.91 doesn't store recovery_offset properly. */
4951 if (mddev->major_version == 0 &&
4952 mddev->minor_version > 90)
4953 rdev->recovery_offset = reshape_offset;
4954
c148ffdc
N		 4955 if (rdev->recovery_offset < reshape_offset) {
4956 /* We need to check old and new layout */
4957 if (!only_parity(rdev->raid_disk,
4958 conf->algorithm,
4959 conf->raid_disks,
4960 conf->max_degraded))
4961 continue;
4962 }
4963 if (!only_parity(rdev->raid_disk,
4964 conf->prev_algo,
4965 conf->previous_raid_disks,
4966 conf->max_degraded))
4967 continue;
4968 dirty_parity_disks++;
4969 }
91adb564 4970
5e5e3e78
N		 4971 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
4972 - working_disks);
91adb564 4973
674806d6 4974 if (has_failed(conf)) {
0c55e022 4975 printk(KERN_ERR "md/raid:%s: not enough operational devices"
1da177e4 4976 " (%d/%d failed)\n",
02c2de8c 4977 mdname(mddev), mddev->degraded, conf->raid_disks);
1da177e4
LT		 4978 goto abort;
4979 }
4980
91adb564 4981 /* device size must be a multiple of chunk size */
9d8f0363 4982 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
91adb564
N		 4983 mddev->resync_max_sectors = mddev->dev_sectors;
4984
c148ffdc 4985 if (mddev->degraded > dirty_parity_disks &&
1da177e4 4986 mddev->recovery_cp != MaxSector) {
6ff8d8ec
N		 4987 if (mddev->ok_start_degraded)
4988 printk(KERN_WARNING
0c55e022
N		 4989 "md/raid:%s: starting dirty degraded array"
4990 " - data corruption possible.\n",
6ff8d8ec
N		 4991 mdname(mddev));
4992 else {
4993 printk(KERN_ERR
0c55e022 4994 "md/raid:%s: cannot start dirty degraded array.\n",
6ff8d8ec
N		 4995 mdname(mddev));
4996 goto abort;
4997 }
1da177e4
LT		 4998 }
4999
1da177e4 5000 if (mddev->degraded == 0)
0c55e022
N		 5001 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5002 " devices, algorithm %d\n", mdname(mddev), conf->level,
e183eaed
N		 5003 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5004 mddev->new_layout);
1da177e4 5005 else
0c55e022
N		 5006 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5007 " out of %d devices, algorithm %d\n",
5008 mdname(mddev), conf->level,
5009 mddev->raid_disks - mddev->degraded,
5010 mddev->raid_disks, mddev->new_layout);
1da177e4
LT		 5011
5012 print_raid5_conf(conf);
5013
fef9c61f 5014 if (conf->reshape_progress != MaxSector) {
fef9c61f 5015 conf->reshape_safe = conf->reshape_progress;
f6705578
N		 5016 atomic_set(&conf->reshape_stripes, 0);
5017 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5018 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5019 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5020 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5021 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 5022 "reshape");
f6705578
N		 5023 }
5024
1da177e4
LT		 5025
5026 /* Ok, everything is just fine now */
a64c876f
N		 5027 if (mddev->to_remove == &raid5_attrs_group)
5028 mddev->to_remove = NULL;
00bcb4ac
N		 5029 else if (mddev->kobj.sd &&
5030 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5e55e2f5 5031 printk(KERN_WARNING
4a5add49 5032 "raid5: failed to create sysfs attributes for %s\n",
5e55e2f5 5033 mdname(mddev));
4a5add49 5034 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7a5febe9 5035
4a5add49 5036 if (mddev->queue) {
9f7c2220 5037 int chunk_size;
4a5add49
N		 5038 /* read-ahead size must cover two whole stripes, which
5039 * is 2 * (datadisks) * chunksize where 'n' is the
5040 * number of raid devices
5041 */
5042 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5043 int stripe = data_disks *
5044 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
5045 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5046 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
91adb564 5047
4a5add49 5048 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
f022b2fd 5049
11d8a6e3
N		 5050 mddev->queue->backing_dev_info.congested_data = mddev;
5051 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
7a5febe9 5052
9f7c2220
N		 5053 chunk_size = mddev->chunk_sectors << 9;
5054 blk_queue_io_min(mddev->queue, chunk_size);
5055 blk_queue_io_opt(mddev->queue, chunk_size *
5056 (conf->raid_disks - conf->max_degraded));
8f6c2e4b 5057
9f7c2220
N		 5058 list_for_each_entry(rdev, &mddev->disks, same_set)
5059 disk_stack_limits(mddev->gendisk, rdev->bdev,
5060 rdev->data_offset << 9);
5061 }
23032a0e 5062
1da177e4
LT		 5063 return 0;
5064abort:
e0cf8f04 5065 md_unregister_thread(mddev->thread);
91adb564 5066 mddev->thread = NULL;
1da177e4
LT		 5067 if (conf) {
5068 print_raid5_conf(conf);
95fc17aa 5069 free_conf(conf);
1da177e4
LT		 5070 }
5071 mddev->private = NULL;
0c55e022 5072 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
1da177e4
LT		 5073 return -EIO;
5074}
5075
3f294f4f 5076static int stop(mddev_t *mddev)
1da177e4 5077{
7b92813c 5078 raid5_conf_t *conf = mddev->private;
1da177e4
LT		 5079
5080 md_unregister_thread(mddev->thread);
5081 mddev->thread = NULL;
11d8a6e3
N		 5082 if (mddev->queue)
5083 mddev->queue->backing_dev_info.congested_fn = NULL;
95fc17aa 5084 free_conf(conf);
a64c876f
N		 5085 mddev->private = NULL;
5086 mddev->to_remove = &raid5_attrs_group;
1da177e4
LT		 5087 return 0;
5088}
5089
45b4233c 5090#ifdef DEBUG
d710e138 5091static void print_sh(struct seq_file *seq, struct stripe_head *sh)
1da177e4
LT		 5092{
5093 int i;
5094
16a53ecc
N		 5095 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
5096 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
5097 seq_printf(seq, "sh %llu, count %d.\n",
5098 (unsigned long long)sh->sector, atomic_read(&sh->count));
5099 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
7ecaa1e6 5100 for (i = 0; i < sh->disks; i++) {
16a53ecc
N		 5101 seq_printf(seq, "(cache%d: %p %ld) ",
5102 i, sh->dev[i].page, sh->dev[i].flags);
1da177e4 5103 }
16a53ecc 5104 seq_printf(seq, "\n");
1da177e4
LT		 5105}
5106
d710e138 5107static void printall(struct seq_file *seq, raid5_conf_t *conf)
1da177e4
LT		 5108{
5109 struct stripe_head *sh;
fccddba0 5110 struct hlist_node *hn;
1da177e4
LT		 5111 int i;
5112
5113 spin_lock_irq(&conf->device_lock);
5114 for (i = 0; i < NR_HASH; i++) {
fccddba0 5115 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
1da177e4
LT		 5116 if (sh->raid_conf != conf)
5117 continue;
16a53ecc 5118 print_sh(seq, sh);
1da177e4
LT		 5119 }
5120 }
5121 spin_unlock_irq(&conf->device_lock);
5122}
5123#endif
5124
d710e138 5125static void status(struct seq_file *seq, mddev_t *mddev)
1da177e4 5126{
7b92813c 5127 raid5_conf_t *conf = mddev->private;
1da177e4
LT		 5128 int i;
5129
9d8f0363
AN		 5130 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5131 mddev->chunk_sectors / 2, mddev->layout);
02c2de8c 5132 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
1da177e4
LT		 5133 for (i = 0; i < conf->raid_disks; i++)
5134 seq_printf (seq, "%s",
5135 conf->disks[i].rdev &&
b2d444d7 5136 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
1da177e4 5137 seq_printf (seq, "]");
45b4233c 5138#ifdef DEBUG
16a53ecc
N		 5139 seq_printf (seq, "\n");
5140 printall(seq, conf);
1da177e4
LT		 5141#endif
5142}
5143
5144static void print_raid5_conf (raid5_conf_t *conf)
5145{
5146 int i;
5147 struct disk_info *tmp;
5148
0c55e022 5149 printk(KERN_DEBUG "RAID conf printout:\n");
1da177e4
LT		 5150 if (!conf) {
5151 printk("(conf==NULL)\n");
5152 return;
5153 }
0c55e022
N		 5154 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
5155 conf->raid_disks,
5156 conf->raid_disks - conf->mddev->degraded);
1da177e4
LT		 5157
5158 for (i = 0; i < conf->raid_disks; i++) {
5159 char b[BDEVNAME_SIZE];
5160 tmp = conf->disks + i;
5161 if (tmp->rdev)
0c55e022
N		 5162 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
5163 i, !test_bit(Faulty, &tmp->rdev->flags),
5164 bdevname(tmp->rdev->bdev, b));
1da177e4
LT		 5165 }
5166}
5167
5168static int raid5_spare_active(mddev_t *mddev)
5169{
5170 int i;
5171 raid5_conf_t *conf = mddev->private;
5172 struct disk_info *tmp;
6b965620
N		 5173 int count = 0;
5174 unsigned long flags;
1da177e4
LT		 5175
5176 for (i = 0; i < conf->raid_disks; i++) {
5177 tmp = conf->disks + i;
5178 if (tmp->rdev
70fffd0b 5179 && tmp->rdev->recovery_offset == MaxSector
b2d444d7 5180 && !test_bit(Faulty, &tmp->rdev->flags)
c04be0aa 5181 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
6b965620 5182 count++;
43c73ca4 5183 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
1da177e4
LT		 5184 }
5185 }
6b965620
N		 5186 spin_lock_irqsave(&conf->device_lock, flags);
5187 mddev->degraded -= count;
5188 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4 5189 print_raid5_conf(conf);
6b965620 5190 return count;
1da177e4
LT		 5191}
5192
5193static int raid5_remove_disk(mddev_t *mddev, int number)
5194{
5195 raid5_conf_t *conf = mddev->private;
5196 int err = 0;
5197 mdk_rdev_t *rdev;
5198 struct disk_info *p = conf->disks + number;
5199
5200 print_raid5_conf(conf);
5201 rdev = p->rdev;
5202 if (rdev) {
ec32a2bd
N		 5203 if (number >= conf->raid_disks &&
5204 conf->reshape_progress == MaxSector)
5205 clear_bit(In_sync, &rdev->flags);
5206
b2d444d7 5207 if (test_bit(In_sync, &rdev->flags) ||
1da177e4
LT		 5208 atomic_read(&rdev->nr_pending)) {
5209 err = -EBUSY;
5210 goto abort;
5211 }
dfc70645
N		 5212 /* Only remove non-faulty devices if recovery
5213 * isn't possible.
5214 */
5215 if (!test_bit(Faulty, &rdev->flags) &&
674806d6 5216 !has_failed(conf) &&
ec32a2bd 5217 number < conf->raid_disks) {
dfc70645
N		 5218 err = -EBUSY;
5219 goto abort;
5220 }
1da177e4 5221 p->rdev = NULL;
fbd568a3 5222 synchronize_rcu();
1da177e4
LT		 5223 if (atomic_read(&rdev->nr_pending)) {
5224 /* lost the race, try later */
5225 err = -EBUSY;
5226 p->rdev = rdev;
5227 }
5228 }
5229abort:
5230
5231 print_raid5_conf(conf);
5232 return err;
5233}
5234
5235static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
5236{
5237 raid5_conf_t *conf = mddev->private;
199050ea 5238 int err = -EEXIST;
1da177e4
LT		 5239 int disk;
5240 struct disk_info *p;
6c2fce2e
NB		 5241 int first = 0;
5242 int last = conf->raid_disks - 1;
1da177e4 5243
674806d6 5244 if (has_failed(conf))
1da177e4 5245 /* no point adding a device */
199050ea 5246 return -EINVAL;
1da177e4 5247
6c2fce2e
NB		 5248 if (rdev->raid_disk >= 0)
5249 first = last = rdev->raid_disk;
1da177e4
LT		 5250
5251 /*
16a53ecc
N		 5252 * find the disk ... but prefer rdev->saved_raid_disk
5253 * if possible.
1da177e4 5254 */
16a53ecc 5255 if (rdev->saved_raid_disk >= 0 &&
6c2fce2e 5256 rdev->saved_raid_disk >= first &&
16a53ecc
N		 5257 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5258 disk = rdev->saved_raid_disk;
5259 else
6c2fce2e
NB		 5260 disk = first;
5261 for ( ; disk <= last ; disk++)
1da177e4 5262 if ((p=conf->disks + disk)->rdev == NULL) {
b2d444d7 5263 clear_bit(In_sync, &rdev->flags);
1da177e4 5264 rdev->raid_disk = disk;
199050ea 5265 err = 0;
72626685
N		 5266 if (rdev->saved_raid_disk != disk)
5267 conf->fullsync = 1;
d6065f7b 5268 rcu_assign_pointer(p->rdev, rdev);
1da177e4
LT		 5269 break;
5270 }
5271 print_raid5_conf(conf);
199050ea 5272 return err;
1da177e4
LT		 5273}
5274
5275static int raid5_resize(mddev_t *mddev, sector_t sectors)
5276{
5277 /* no resync is happening, and there is enough space
5278 * on all devices, so we can resize.
5279 * We need to make sure resync covers any new space.
5280 * If the array is shrinking we should possibly wait until
5281 * any io in the removed space completes, but it hardly seems
5282 * worth it.
5283 */
9d8f0363 5284 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
1f403624
DW		 5285 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
5286 mddev->raid_disks));
b522adcd
DW		 5287 if (mddev->array_sectors >
5288 raid5_size(mddev, sectors, mddev->raid_disks))
5289 return -EINVAL;
f233ea5c 5290 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 5291 revalidate_disk(mddev->gendisk);
b098636c
N		 5292 if (sectors > mddev->dev_sectors &&
5293 mddev->recovery_cp > mddev->dev_sectors) {
58c0fed4 5294 mddev->recovery_cp = mddev->dev_sectors;
1da177e4
LT		 5295 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5296 }
58c0fed4 5297 mddev->dev_sectors = sectors;
4b5c7ae8 5298 mddev->resync_max_sectors = sectors;
1da177e4
LT		 5299 return 0;
5300}
5301
01ee22b4
N		 5302static int check_stripe_cache(mddev_t *mddev)
5303{
5304 /* Can only proceed if there are plenty of stripe_heads.
5305 * We need a minimum of one full stripe,, and for sensible progress
5306 * it is best to have about 4 times that.
5307 * If we require 4 times, then the default 256 4K stripe_heads will
5308 * allow for chunk sizes up to 256K, which is probably OK.
5309 * If the chunk size is greater, user-space should request more
5310 * stripe_heads first.
5311 */
5312 raid5_conf_t *conf = mddev->private;
5313 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5314 > conf->max_nr_stripes ||
5315 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5316 > conf->max_nr_stripes) {
0c55e022
N		 5317 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5318 mdname(mddev),
01ee22b4
N		 5319 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5320 / STRIPE_SIZE)*4);
5321 return 0;
5322 }
5323 return 1;
5324}
5325
50ac168a 5326static int check_reshape(mddev_t *mddev)
29269553 5327{
070ec55d 5328 raid5_conf_t *conf = mddev->private;
29269553 5329
88ce4930
N		 5330 if (mddev->delta_disks == 0 &&
5331 mddev->new_layout == mddev->layout &&
664e7c41 5332 mddev->new_chunk_sectors == mddev->chunk_sectors)
50ac168a 5333 return 0; /* nothing to do */
dba034ee
N		 5334 if (mddev->bitmap)
5335 /* Cannot grow a bitmap yet */
5336 return -EBUSY;
674806d6 5337 if (has_failed(conf))
ec32a2bd
N		 5338 return -EINVAL;
5339 if (mddev->delta_disks < 0) {
5340 /* We might be able to shrink, but the devices must
5341 * be made bigger first.
5342 * For raid6, 4 is the minimum size.
5343 * Otherwise 2 is the minimum
5344 */
5345 int min = 2;
5346 if (mddev->level == 6)
5347 min = 4;
5348 if (mddev->raid_disks + mddev->delta_disks < min)
5349 return -EINVAL;
5350 }
29269553 5351
01ee22b4 5352 if (!check_stripe_cache(mddev))
29269553 5353 return -ENOSPC;
29269553 5354
ec32a2bd 5355 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
63c70c4f
N		 5356}
5357
5358static int raid5_start_reshape(mddev_t *mddev)
5359{
070ec55d 5360 raid5_conf_t *conf = mddev->private;
63c70c4f 5361 mdk_rdev_t *rdev;
63c70c4f 5362 int spares = 0;
c04be0aa 5363 unsigned long flags;
63c70c4f 5364
f416885e 5365 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
63c70c4f
N		 5366 return -EBUSY;
5367
01ee22b4
N		 5368 if (!check_stripe_cache(mddev))
5369 return -ENOSPC;
5370
159ec1fc 5371 list_for_each_entry(rdev, &mddev->disks, same_set)
469518a3
N		 5372 if (!test_bit(In_sync, &rdev->flags)
5373 && !test_bit(Faulty, &rdev->flags))
29269553 5374 spares++;
63c70c4f 5375
f416885e 5376 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
29269553
N		 5377 /* Not enough devices even to make a degraded array
5378 * of that size
5379 */
5380 return -EINVAL;
5381
ec32a2bd
N		 5382 /* Refuse to reduce size of the array. Any reductions in
5383 * array size must be through explicit setting of array_size
5384 * attribute.
5385 */
5386 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5387 < mddev->array_sectors) {
0c55e022 5388 printk(KERN_ERR "md/raid:%s: array size must be reduced "
ec32a2bd
N		 5389 "before number of disks\n", mdname(mddev));
5390 return -EINVAL;
5391 }
5392
f6705578 5393 atomic_set(&conf->reshape_stripes, 0);
29269553
N		 5394 spin_lock_irq(&conf->device_lock);
5395 conf->previous_raid_disks = conf->raid_disks;
63c70c4f 5396 conf->raid_disks += mddev->delta_disks;
09c9e5fa
AN		 5397 conf->prev_chunk_sectors = conf->chunk_sectors;
5398 conf->chunk_sectors = mddev->new_chunk_sectors;
88ce4930
N		 5399 conf->prev_algo = conf->algorithm;
5400 conf->algorithm = mddev->new_layout;
fef9c61f
N		 5401 if (mddev->delta_disks < 0)
5402 conf->reshape_progress = raid5_size(mddev, 0, 0);
5403 else
5404 conf->reshape_progress = 0;
5405 conf->reshape_safe = conf->reshape_progress;
86b42c71 5406 conf->generation++;
29269553
N		 5407 spin_unlock_irq(&conf->device_lock);
5408
5409 /* Add some new drives, as many as will fit.
5410 * We know there are enough to make the newly sized array work.
3424bf6a
N		 5411 * Don't add devices if we are reducing the number of
5412 * devices in the array. This is because it is not possible
5413 * to correctly record the "partially reconstructed" state of
5414 * such devices during the reshape and confusion could result.
29269553 5415 */
87a8dec9
N		 5416 if (mddev->delta_disks >= 0) {
5417 int added_devices = 0;
5418 list_for_each_entry(rdev, &mddev->disks, same_set)
5419 if (rdev->raid_disk < 0 &&
5420 !test_bit(Faulty, &rdev->flags)) {
5421 if (raid5_add_disk(mddev, rdev) == 0) {
5422 char nm[20];
5423 if (rdev->raid_disk
5424 >= conf->previous_raid_disks) {
5425 set_bit(In_sync, &rdev->flags);
5426 added_devices++;
5427 } else
5428 rdev->recovery_offset = 0;
5429 sprintf(nm, "rd%d", rdev->raid_disk);
5430 if (sysfs_create_link(&mddev->kobj,
5431 &rdev->kobj, nm))
5432 /* Failure here is OK */;
50da0840 5433 }
87a8dec9
N		 5434 } else if (rdev->raid_disk >= conf->previous_raid_disks
5435 && !test_bit(Faulty, &rdev->flags)) {
5436 /* This is a spare that was manually added */
5437 set_bit(In_sync, &rdev->flags);
5438 added_devices++;
5439 }
29269553 5440
87a8dec9
N		 5441 /* When a reshape changes the number of devices,
5442 * ->degraded is measured against the larger of the
5443 * pre and post number of devices.
5444 */
ec32a2bd 5445 spin_lock_irqsave(&conf->device_lock, flags);
9eb07c25 5446 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
ec32a2bd
N		 5447 - added_devices;
5448 spin_unlock_irqrestore(&conf->device_lock, flags);
5449 }
63c70c4f 5450 mddev->raid_disks = conf->raid_disks;
e516402c 5451 mddev->reshape_position = conf->reshape_progress;
850b2b42 5452 set_bit(MD_CHANGE_DEVS, &mddev->flags);
f6705578 5453
29269553
N		 5454 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5455 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5456 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5457 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5458 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 5459 "reshape");
29269553
N		 5460 if (!mddev->sync_thread) {
5461 mddev->recovery = 0;
5462 spin_lock_irq(&conf->device_lock);
5463 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
fef9c61f 5464 conf->reshape_progress = MaxSector;
29269553
N		 5465 spin_unlock_irq(&conf->device_lock);
5466 return -EAGAIN;
5467 }
c8f517c4 5468 conf->reshape_checkpoint = jiffies;
29269553
N		 5469 md_wakeup_thread(mddev->sync_thread);
5470 md_new_event(mddev);
5471 return 0;
5472}
29269553 5473
ec32a2bd
N		 5474/* This is called from the reshape thread and should make any
5475 * changes needed in 'conf'
5476 */
29269553
N		 5477static void end_reshape(raid5_conf_t *conf)
5478{
29269553 5479
f6705578 5480 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
f6705578 5481
f6705578 5482 spin_lock_irq(&conf->device_lock);
cea9c228 5483 conf->previous_raid_disks = conf->raid_disks;
fef9c61f 5484 conf->reshape_progress = MaxSector;
f6705578 5485 spin_unlock_irq(&conf->device_lock);
b0f9ec04 5486 wake_up(&conf->wait_for_overlap);
16a53ecc
N		 5487
5488 /* read-ahead size must cover two whole stripes, which is
5489 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5490 */
4a5add49 5491 if (conf->mddev->queue) {
cea9c228 5492 int data_disks = conf->raid_disks - conf->max_degraded;
09c9e5fa 5493 int stripe = data_disks * ((conf->chunk_sectors << 9)
cea9c228 5494 / PAGE_SIZE);
16a53ecc
N		 5495 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5496 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5497 }
29269553 5498 }
29269553
N		 5499}
5500
ec32a2bd
N		 5501/* This is called from the raid5d thread with mddev_lock held.
5502 * It makes config changes to the device.
5503 */
cea9c228
N		 5504static void raid5_finish_reshape(mddev_t *mddev)
5505{
070ec55d 5506 raid5_conf_t *conf = mddev->private;
cea9c228
N		 5507
5508 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5509
ec32a2bd
N		 5510 if (mddev->delta_disks > 0) {
5511 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5512 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 5513 revalidate_disk(mddev->gendisk);
ec32a2bd
N		 5514 } else {
5515 int d;
ec32a2bd
N		 5516 mddev->degraded = conf->raid_disks;
5517 for (d = 0; d < conf->raid_disks ; d++)
5518 if (conf->disks[d].rdev &&
5519 test_bit(In_sync,
5520 &conf->disks[d].rdev->flags))
5521 mddev->degraded--;
5522 for (d = conf->raid_disks ;
5523 d < conf->raid_disks - mddev->delta_disks;
1a67dde0
N		 5524 d++) {
5525 mdk_rdev_t *rdev = conf->disks[d].rdev;
5526 if (rdev && raid5_remove_disk(mddev, d) == 0) {
5527 char nm[20];
5528 sprintf(nm, "rd%d", rdev->raid_disk);
5529 sysfs_remove_link(&mddev->kobj, nm);
5530 rdev->raid_disk = -1;
5531 }
5532 }
cea9c228 5533 }
88ce4930 5534 mddev->layout = conf->algorithm;
09c9e5fa 5535 mddev->chunk_sectors = conf->chunk_sectors;
ec32a2bd
N		 5536 mddev->reshape_position = MaxSector;
5537 mddev->delta_disks = 0;
cea9c228
N		 5538 }
5539}
5540
72626685
N		 5541static void raid5_quiesce(mddev_t *mddev, int state)
5542{
070ec55d 5543 raid5_conf_t *conf = mddev->private;
72626685
N		 5544
5545 switch(state) {
e464eafd
N		 5546 case 2: /* resume for a suspend */
5547 wake_up(&conf->wait_for_overlap);
5548 break;
5549
72626685
N		 5550 case 1: /* stop all writes */
5551 spin_lock_irq(&conf->device_lock);
64bd660b
N		 5552 /* '2' tells resync/reshape to pause so that all
5553 * active stripes can drain
5554 */
5555 conf->quiesce = 2;
72626685 5556 wait_event_lock_irq(conf->wait_for_stripe,
46031f9a
RBJ		 5557 atomic_read(&conf->active_stripes) == 0 &&
5558 atomic_read(&conf->active_aligned_reads) == 0,
72626685 5559 conf->device_lock, /* nothing */);
64bd660b 5560 conf->quiesce = 1;
72626685 5561 spin_unlock_irq(&conf->device_lock);
64bd660b
N		 5562 /* allow reshape to continue */
5563 wake_up(&conf->wait_for_overlap);
72626685
N		 5564 break;
5565
5566 case 0: /* re-enable writes */
5567 spin_lock_irq(&conf->device_lock);
5568 conf->quiesce = 0;
5569 wake_up(&conf->wait_for_stripe);
e464eafd 5570 wake_up(&conf->wait_for_overlap);
72626685
N		 5571 spin_unlock_irq(&conf->device_lock);
5572 break;
5573 }
72626685 5574}
b15c2e57 5575
d562b0c4 5576
f1b29bca 5577static void *raid45_takeover_raid0(mddev_t *mddev, int level)
54071b38 5578{
f1b29bca 5579 struct raid0_private_data *raid0_priv = mddev->private;
d76c8420 5580 sector_t sectors;
54071b38 5581
f1b29bca
DW		 5582 /* for raid0 takeover only one zone is supported */
5583 if (raid0_priv->nr_strip_zones > 1) {
0c55e022
N		 5584 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5585 mdname(mddev));
f1b29bca
DW		 5586 return ERR_PTR(-EINVAL);
5587 }
5588
3b71bd93
N		 5589 sectors = raid0_priv->strip_zone[0].zone_end;
5590 sector_div(sectors, raid0_priv->strip_zone[0].nb_dev);
5591 mddev->dev_sectors = sectors;
f1b29bca 5592 mddev->new_level = level;
54071b38
TM		 5593 mddev->new_layout = ALGORITHM_PARITY_N;
5594 mddev->new_chunk_sectors = mddev->chunk_sectors;
5595 mddev->raid_disks += 1;
5596 mddev->delta_disks = 1;
5597 /* make sure it will be not marked as dirty */
5598 mddev->recovery_cp = MaxSector;
5599
5600 return setup_conf(mddev);
5601}
5602
5603
d562b0c4
N		 5604static void *raid5_takeover_raid1(mddev_t *mddev)
5605{
5606 int chunksect;
5607
5608 if (mddev->raid_disks != 2 ||
5609 mddev->degraded > 1)
5610 return ERR_PTR(-EINVAL);
5611
5612 /* Should check if there are write-behind devices? */
5613
5614 chunksect = 64*2; /* 64K by default */
5615
5616 /* The array must be an exact multiple of chunksize */
5617 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5618 chunksect >>= 1;
5619
5620 if ((chunksect<<9) < STRIPE_SIZE)
5621 /* array size does not allow a suitable chunk size */
5622 return ERR_PTR(-EINVAL);
5623
5624 mddev->new_level = 5;
5625 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
664e7c41 5626 mddev->new_chunk_sectors = chunksect;
d562b0c4
N		 5627
5628 return setup_conf(mddev);
5629}
5630
fc9739c6
N		 5631static void *raid5_takeover_raid6(mddev_t *mddev)
5632{
5633 int new_layout;
5634
5635 switch (mddev->layout) {
5636 case ALGORITHM_LEFT_ASYMMETRIC_6:
5637 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5638 break;
5639 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5640 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5641 break;
5642 case ALGORITHM_LEFT_SYMMETRIC_6:
5643 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5644 break;
5645 case ALGORITHM_RIGHT_SYMMETRIC_6:
5646 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5647 break;
5648 case ALGORITHM_PARITY_0_6:
5649 new_layout = ALGORITHM_PARITY_0;
5650 break;
5651 case ALGORITHM_PARITY_N:
5652 new_layout = ALGORITHM_PARITY_N;
5653 break;
5654 default:
5655 return ERR_PTR(-EINVAL);
5656 }
5657 mddev->new_level = 5;
5658 mddev->new_layout = new_layout;
5659 mddev->delta_disks = -1;
5660 mddev->raid_disks -= 1;
5661 return setup_conf(mddev);
5662}
5663
d562b0c4 5664
50ac168a 5665static int raid5_check_reshape(mddev_t *mddev)
b3546035 5666{
88ce4930
N		 5667 /* For a 2-drive array, the layout and chunk size can be changed
5668 * immediately as not restriping is needed.
5669 * For larger arrays we record the new value - after validation
5670 * to be used by a reshape pass.
b3546035 5671 */
070ec55d 5672 raid5_conf_t *conf = mddev->private;
597a711b 5673 int new_chunk = mddev->new_chunk_sectors;
b3546035 5674
597a711b 5675 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
b3546035
N		 5676 return -EINVAL;
5677 if (new_chunk > 0) {
0ba459d2 5678 if (!is_power_of_2(new_chunk))
b3546035 5679 return -EINVAL;
597a711b 5680 if (new_chunk < (PAGE_SIZE>>9))
b3546035 5681 return -EINVAL;
597a711b 5682 if (mddev->array_sectors & (new_chunk-1))
b3546035
N		 5683 /* not factor of array size */
5684 return -EINVAL;
5685 }
5686
5687 /* They look valid */
5688
88ce4930 5689 if (mddev->raid_disks == 2) {
597a711b
N		 5690 /* can make the change immediately */
5691 if (mddev->new_layout >= 0) {
5692 conf->algorithm = mddev->new_layout;
5693 mddev->layout = mddev->new_layout;
88ce4930
N		 5694 }
5695 if (new_chunk > 0) {
597a711b
N		 5696 conf->chunk_sectors = new_chunk ;
5697 mddev->chunk_sectors = new_chunk;
88ce4930
N		 5698 }
5699 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5700 md_wakeup_thread(mddev->thread);
b3546035 5701 }
50ac168a 5702 return check_reshape(mddev);
88ce4930
N		 5703}
5704
50ac168a 5705static int raid6_check_reshape(mddev_t *mddev)
88ce4930 5706{
597a711b 5707 int new_chunk = mddev->new_chunk_sectors;
50ac168a 5708
597a711b 5709 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
88ce4930 5710 return -EINVAL;
b3546035 5711 if (new_chunk > 0) {
0ba459d2 5712 if (!is_power_of_2(new_chunk))
88ce4930 5713 return -EINVAL;
597a711b 5714 if (new_chunk < (PAGE_SIZE >> 9))
88ce4930 5715 return -EINVAL;
597a711b 5716 if (mddev->array_sectors & (new_chunk-1))
88ce4930
N		 5717 /* not factor of array size */
5718 return -EINVAL;
b3546035 5719 }
88ce4930
N		 5720
5721 /* They look valid */
50ac168a 5722 return check_reshape(mddev);
b3546035
N		 5723}
5724
d562b0c4
N		 5725static void *raid5_takeover(mddev_t *mddev)
5726{
5727 /* raid5 can take over:
f1b29bca 5728 * raid0 - if there is only one strip zone - make it a raid4 layout
d562b0c4
N		 5729 * raid1 - if there are two drives. We need to know the chunk size
5730 * raid4 - trivial - just use a raid4 layout.
5731 * raid6 - Providing it is a *_6 layout
d562b0c4 5732 */
f1b29bca
DW		 5733 if (mddev->level == 0)
5734 return raid45_takeover_raid0(mddev, 5);
d562b0c4
N		 5735 if (mddev->level == 1)
5736 return raid5_takeover_raid1(mddev);
e9d4758f
N		 5737 if (mddev->level == 4) {
5738 mddev->new_layout = ALGORITHM_PARITY_N;
5739 mddev->new_level = 5;
5740 return setup_conf(mddev);
5741 }
fc9739c6
N		 5742 if (mddev->level == 6)
5743 return raid5_takeover_raid6(mddev);
d562b0c4
N		 5744
5745 return ERR_PTR(-EINVAL);
5746}
5747
a78d38a1
N		 5748static void *raid4_takeover(mddev_t *mddev)
5749{
f1b29bca
DW		 5750 /* raid4 can take over:
5751 * raid0 - if there is only one strip zone
5752 * raid5 - if layout is right
a78d38a1 5753 */
f1b29bca
DW		 5754 if (mddev->level == 0)
5755 return raid45_takeover_raid0(mddev, 4);
a78d38a1
N		 5756 if (mddev->level == 5 &&
5757 mddev->layout == ALGORITHM_PARITY_N) {
5758 mddev->new_layout = 0;
5759 mddev->new_level = 4;
5760 return setup_conf(mddev);
5761 }
5762 return ERR_PTR(-EINVAL);
5763}
d562b0c4 5764
245f46c2
N		 5765static struct mdk_personality raid5_personality;
5766
5767static void *raid6_takeover(mddev_t *mddev)
5768{
5769 /* Currently can only take over a raid5. We map the
5770 * personality to an equivalent raid6 personality
5771 * with the Q block at the end.
5772 */
5773 int new_layout;
5774
5775 if (mddev->pers != &raid5_personality)
5776 return ERR_PTR(-EINVAL);
5777 if (mddev->degraded > 1)
5778 return ERR_PTR(-EINVAL);
5779 if (mddev->raid_disks > 253)
5780 return ERR_PTR(-EINVAL);
5781 if (mddev->raid_disks < 3)
5782 return ERR_PTR(-EINVAL);
5783
5784 switch (mddev->layout) {
5785 case ALGORITHM_LEFT_ASYMMETRIC:
5786 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5787 break;
5788 case ALGORITHM_RIGHT_ASYMMETRIC:
5789 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5790 break;
5791 case ALGORITHM_LEFT_SYMMETRIC:
5792 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5793 break;
5794 case ALGORITHM_RIGHT_SYMMETRIC:
5795 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5796 break;
5797 case ALGORITHM_PARITY_0:
5798 new_layout = ALGORITHM_PARITY_0_6;
5799 break;
5800 case ALGORITHM_PARITY_N:
5801 new_layout = ALGORITHM_PARITY_N;
5802 break;
5803 default:
5804 return ERR_PTR(-EINVAL);
5805 }
5806 mddev->new_level = 6;
5807 mddev->new_layout = new_layout;
5808 mddev->delta_disks = 1;
5809 mddev->raid_disks += 1;
5810 return setup_conf(mddev);
5811}
5812
5813
16a53ecc
N		 5814static struct mdk_personality raid6_personality =
5815{
5816 .name = "raid6",
5817 .level = 6,
5818 .owner = THIS_MODULE,
5819 .make_request = make_request,
5820 .run = run,
5821 .stop = stop,
5822 .status = status,
5823 .error_handler = error,
5824 .hot_add_disk = raid5_add_disk,
5825 .hot_remove_disk= raid5_remove_disk,
5826 .spare_active = raid5_spare_active,
5827 .sync_request = sync_request,
5828 .resize = raid5_resize,
80c3a6ce 5829 .size = raid5_size,
50ac168a 5830 .check_reshape = raid6_check_reshape,
f416885e 5831 .start_reshape = raid5_start_reshape,
cea9c228 5832 .finish_reshape = raid5_finish_reshape,
16a53ecc 5833 .quiesce = raid5_quiesce,
245f46c2 5834 .takeover = raid6_takeover,
16a53ecc 5835};
2604b703 5836static struct mdk_personality raid5_personality =
1da177e4
LT		 5837{
5838 .name = "raid5",
2604b703 5839 .level = 5,
1da177e4
LT		 5840 .owner = THIS_MODULE,
5841 .make_request = make_request,
5842 .run = run,
5843 .stop = stop,
5844 .status = status,
5845 .error_handler = error,
5846 .hot_add_disk = raid5_add_disk,
5847 .hot_remove_disk= raid5_remove_disk,
5848 .spare_active = raid5_spare_active,
5849 .sync_request = sync_request,
5850 .resize = raid5_resize,
80c3a6ce 5851 .size = raid5_size,
63c70c4f
N		 5852 .check_reshape = raid5_check_reshape,
5853 .start_reshape = raid5_start_reshape,
cea9c228 5854 .finish_reshape = raid5_finish_reshape,
72626685 5855 .quiesce = raid5_quiesce,
d562b0c4 5856 .takeover = raid5_takeover,
1da177e4
LT		 5857};
5858
2604b703 5859static struct mdk_personality raid4_personality =
1da177e4 5860{
2604b703
N		 5861 .name = "raid4",
5862 .level = 4,
5863 .owner = THIS_MODULE,
5864 .make_request = make_request,
5865 .run = run,
5866 .stop = stop,
5867 .status = status,
5868 .error_handler = error,
5869 .hot_add_disk = raid5_add_disk,
5870 .hot_remove_disk= raid5_remove_disk,
5871 .spare_active = raid5_spare_active,
5872 .sync_request = sync_request,
5873 .resize = raid5_resize,
80c3a6ce 5874 .size = raid5_size,
3d37890b
N		 5875 .check_reshape = raid5_check_reshape,
5876 .start_reshape = raid5_start_reshape,
cea9c228 5877 .finish_reshape = raid5_finish_reshape,
2604b703 5878 .quiesce = raid5_quiesce,
a78d38a1 5879 .takeover = raid4_takeover,
2604b703
N		 5880};
5881
5882static int __init raid5_init(void)
5883{
16a53ecc 5884 register_md_personality(&raid6_personality);
2604b703
N		 5885 register_md_personality(&raid5_personality);
5886 register_md_personality(&raid4_personality);
5887 return 0;
1da177e4
LT		 5888}
5889
2604b703 5890static void raid5_exit(void)
1da177e4 5891{
16a53ecc 5892 unregister_md_personality(&raid6_personality);
2604b703
N		 5893 unregister_md_personality(&raid5_personality);
5894 unregister_md_personality(&raid4_personality);
1da177e4
LT		 5895}
5896
5897module_init(raid5_init);
5898module_exit(raid5_exit);
5899MODULE_LICENSE("GPL");
0efb9e61 5900MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
1da177e4 5901MODULE_ALIAS("md-personality-4"); /* RAID5 */
d9d166c2
N		 5902MODULE_ALIAS("md-raid5");
5903MODULE_ALIAS("md-raid4");
2604b703
N		 5904MODULE_ALIAS("md-level-5");
5905MODULE_ALIAS("md-level-4");
16a53ecc
N		 5906MODULE_ALIAS("md-personality-8"); /* RAID6 */
5907MODULE_ALIAS("md-raid6");
5908MODULE_ALIAS("md-level-6");
5909
5910/* This used to be two separate modules, they were: */
5911MODULE_ALIAS("raid5");
5912MODULE_ALIAS("raid6");