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raid5: get_active_stripe avoids device_lock
[linux-2.6-block.git] / drivers / md / raid5.c
CommitLineData
1da177e4
LT		 1/*
2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
16a53ecc 5 * Copyright (C) 2002, 2003 H. Peter Anvin
1da177e4 6 *
16a53ecc
N		 7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
1da177e4
LT		 10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
ae3c20cc
N		 21/*
22 * BITMAP UNPLUGGING:
23 *
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
26 * explanation.
27 *
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
7c13edc8
N		 30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
ae3c20cc
N		 32 * new additions.
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
7c13edc8 35 * the number of the batch it will be in. This is seq_flush+1.
ae3c20cc
N		 36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
39 * batch.
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
43 * miss any bits.
44 */
1da177e4 45
bff61975 46#include <linux/blkdev.h>
f6705578 47#include <linux/kthread.h>
f701d589 48#include <linux/raid/pq.h>
91c00924 49#include <linux/async_tx.h>
056075c7 50#include <linux/module.h>
07a3b417 51#include <linux/async.h>
bff61975 52#include <linux/seq_file.h>
36d1c647 53#include <linux/cpu.h>
5a0e3ad6 54#include <linux/slab.h>
8bda470e 55#include <linux/ratelimit.h>
851c30c9 56#include <linux/nodemask.h>
a9add5d9
N		 57#include <trace/events/block.h>
58
43b2e5d8 59#include "md.h"
bff61975 60#include "raid5.h"
54071b38 61#include "raid0.h"
ef740c37 62#include "bitmap.h"
72626685 63
851c30c9
SL		 64#define cpu_to_group(cpu) cpu_to_node(cpu)
65#define ANY_GROUP NUMA_NO_NODE
66
67static struct workqueue_struct *raid5_wq;
1da177e4
LT		 68/*
69 * Stripe cache
70 */
71
72#define NR_STRIPES 256
73#define STRIPE_SIZE PAGE_SIZE
74#define STRIPE_SHIFT (PAGE_SHIFT - 9)
75#define STRIPE_SECTORS (STRIPE_SIZE>>9)
76#define IO_THRESHOLD 1
8b3e6cdc 77#define BYPASS_THRESHOLD 1
fccddba0 78#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
1da177e4 79#define HASH_MASK (NR_HASH - 1)
bfc90cb0 80#define MAX_STRIPE_BATCH 8
1da177e4 81
d1688a6d 82static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
db298e19
N		 83{
84 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK;
85 return &conf->stripe_hashtbl[hash];
86}
1da177e4 87
566c09c5
SL		 88static inline int stripe_hash_locks_hash(sector_t sect)
89{
90 return (sect >> STRIPE_SHIFT) & STRIPE_HASH_LOCKS_MASK;
91}
92
93static inline void lock_device_hash_lock(struct r5conf *conf, int hash)
94{
95 spin_lock_irq(conf->hash_locks + hash);
96 spin_lock(&conf->device_lock);
97}
98
99static inline void unlock_device_hash_lock(struct r5conf *conf, int hash)
100{
101 spin_unlock(&conf->device_lock);
102 spin_unlock_irq(conf->hash_locks + hash);
103}
104
105static inline void lock_all_device_hash_locks_irq(struct r5conf *conf)
106{
107 int i;
108 local_irq_disable();
109 spin_lock(conf->hash_locks);
110 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
111 spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks);
112 spin_lock(&conf->device_lock);
113}
114
115static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf)
116{
117 int i;
118 spin_unlock(&conf->device_lock);
119 for (i = NR_STRIPE_HASH_LOCKS; i; i--)
120 spin_unlock(conf->hash_locks + i - 1);
121 local_irq_enable();
122}
123
1da177e4
LT		 124/* bio's attached to a stripe+device for I/O are linked together in bi_sector
125 * order without overlap. There may be several bio's per stripe+device, and
126 * a bio could span several devices.
127 * When walking this list for a particular stripe+device, we must never proceed
128 * beyond a bio that extends past this device, as the next bio might no longer
129 * be valid.
db298e19 130 * This function is used to determine the 'next' bio in the list, given the sector
1da177e4
LT		 131 * of the current stripe+device
132 */
db298e19
N		 133static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
134{
aa8b57aa 135 int sectors = bio_sectors(bio);
4f024f37 136 if (bio->bi_iter.bi_sector + sectors < sector + STRIPE_SECTORS)
db298e19
N		 137 return bio->bi_next;
138 else
139 return NULL;
140}
1da177e4 141
960e739d 142/*
5b99c2ff
JA		 143 * We maintain a biased count of active stripes in the bottom 16 bits of
144 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
960e739d 145 */
e7836bd6 146static inline int raid5_bi_processed_stripes(struct bio *bio)
960e739d 147{
e7836bd6
SL		 148 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
149 return (atomic_read(segments) >> 16) & 0xffff;
960e739d
JA		 150}
151
e7836bd6 152static inline int raid5_dec_bi_active_stripes(struct bio *bio)
960e739d 153{
e7836bd6
SL		 154 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
155 return atomic_sub_return(1, segments) & 0xffff;
960e739d
JA		 156}
157
e7836bd6 158static inline void raid5_inc_bi_active_stripes(struct bio *bio)
960e739d 159{
e7836bd6
SL		 160 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
161 atomic_inc(segments);
960e739d
JA		 162}
163
e7836bd6
SL		 164static inline void raid5_set_bi_processed_stripes(struct bio *bio,
165 unsigned int cnt)
960e739d 166{
e7836bd6
SL		 167 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
168 int old, new;
960e739d 169
e7836bd6
SL		 170 do {
171 old = atomic_read(segments);
172 new = (old & 0xffff) | (cnt << 16);
173 } while (atomic_cmpxchg(segments, old, new) != old);
960e739d
JA		 174}
175
e7836bd6 176static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
960e739d 177{
e7836bd6
SL		 178 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
179 atomic_set(segments, cnt);
960e739d
JA		 180}
181
d0dabf7e
N		 182/* Find first data disk in a raid6 stripe */
183static inline int raid6_d0(struct stripe_head *sh)
184{
67cc2b81
N		 185 if (sh->ddf_layout)
186 /* ddf always start from first device */
187 return 0;
188 /* md starts just after Q block */
d0dabf7e
N		 189 if (sh->qd_idx == sh->disks - 1)
190 return 0;
191 else
192 return sh->qd_idx + 1;
193}
16a53ecc
N		 194static inline int raid6_next_disk(int disk, int raid_disks)
195{
196 disk++;
197 return (disk < raid_disks) ? disk : 0;
198}
a4456856 199
d0dabf7e
N		 200/* When walking through the disks in a raid5, starting at raid6_d0,
201 * We need to map each disk to a 'slot', where the data disks are slot
202 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
203 * is raid_disks-1. This help does that mapping.
204 */
67cc2b81
N		 205static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
206 int *count, int syndrome_disks)
d0dabf7e 207{
6629542e 208 int slot = *count;
67cc2b81 209
e4424fee 210 if (sh->ddf_layout)
6629542e 211 (*count)++;
d0dabf7e 212 if (idx == sh->pd_idx)
67cc2b81 213 return syndrome_disks;
d0dabf7e 214 if (idx == sh->qd_idx)
67cc2b81 215 return syndrome_disks + 1;
e4424fee 216 if (!sh->ddf_layout)
6629542e 217 (*count)++;
d0dabf7e
N		 218 return slot;
219}
220
a4456856
DW		 221static void return_io(struct bio *return_bi)
222{
223 struct bio *bi = return_bi;
224 while (bi) {
a4456856
DW		 225
226 return_bi = bi->bi_next;
227 bi->bi_next = NULL;
4f024f37 228 bi->bi_iter.bi_size = 0;
0a82a8d1
LT		 229 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
230 bi, 0);
0e13fe23 231 bio_endio(bi, 0);
a4456856
DW		 232 bi = return_bi;
233 }
234}
235
d1688a6d 236static void print_raid5_conf (struct r5conf *conf);
1da177e4 237
600aa109
DW		 238static int stripe_operations_active(struct stripe_head *sh)
239{
240 return sh->check_state || sh->reconstruct_state ||
241 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
242 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
243}
244
851c30c9
SL		 245static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
246{
247 struct r5conf *conf = sh->raid_conf;
248 struct r5worker_group *group;
bfc90cb0 249 int thread_cnt;
851c30c9
SL		 250 int i, cpu = sh->cpu;
251
252 if (!cpu_online(cpu)) {
253 cpu = cpumask_any(cpu_online_mask);
254 sh->cpu = cpu;
255 }
256
257 if (list_empty(&sh->lru)) {
258 struct r5worker_group *group;
259 group = conf->worker_groups + cpu_to_group(cpu);
260 list_add_tail(&sh->lru, &group->handle_list);
bfc90cb0
SL		 261 group->stripes_cnt++;
262 sh->group = group;
851c30c9
SL		 263 }
264
265 if (conf->worker_cnt_per_group == 0) {
266 md_wakeup_thread(conf->mddev->thread);
267 return;
268 }
269
270 group = conf->worker_groups + cpu_to_group(sh->cpu);
271
bfc90cb0
SL		 272 group->workers[0].working = true;
273 /* at least one worker should run to avoid race */
274 queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
275
276 thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
277 /* wakeup more workers */
278 for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
279 if (group->workers[i].working == false) {
280 group->workers[i].working = true;
281 queue_work_on(sh->cpu, raid5_wq,
282 &group->workers[i].work);
283 thread_cnt--;
284 }
285 }
851c30c9
SL		 286}
287
566c09c5
SL		 288static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
289 struct list_head *temp_inactive_list)
1da177e4 290{
4eb788df
SL		 291 BUG_ON(!list_empty(&sh->lru));
292 BUG_ON(atomic_read(&conf->active_stripes)==0);
293 if (test_bit(STRIPE_HANDLE, &sh->state)) {
294 if (test_bit(STRIPE_DELAYED, &sh->state) &&
295 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
296 list_add_tail(&sh->lru, &conf->delayed_list);
297 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
298 sh->bm_seq - conf->seq_write > 0)
299 list_add_tail(&sh->lru, &conf->bitmap_list);
300 else {
301 clear_bit(STRIPE_DELAYED, &sh->state);
302 clear_bit(STRIPE_BIT_DELAY, &sh->state);
851c30c9
SL		 303 if (conf->worker_cnt_per_group == 0) {
304 list_add_tail(&sh->lru, &conf->handle_list);
305 } else {
306 raid5_wakeup_stripe_thread(sh);
307 return;
308 }
4eb788df
SL		 309 }
310 md_wakeup_thread(conf->mddev->thread);
311 } else {
312 BUG_ON(stripe_operations_active(sh));
313 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
314 if (atomic_dec_return(&conf->preread_active_stripes)
315 < IO_THRESHOLD)
316 md_wakeup_thread(conf->mddev->thread);
317 atomic_dec(&conf->active_stripes);
566c09c5
SL		 318 if (!test_bit(STRIPE_EXPANDING, &sh->state))
319 list_add_tail(&sh->lru, temp_inactive_list);
1da177e4
LT		 320 }
321}
d0dabf7e 322
566c09c5
SL		 323static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
324 struct list_head *temp_inactive_list)
4eb788df
SL		 325{
326 if (atomic_dec_and_test(&sh->count))
566c09c5
SL		 327 do_release_stripe(conf, sh, temp_inactive_list);
328}
329
330/*
331 * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
332 *
333 * Be careful: Only one task can add/delete stripes from temp_inactive_list at
334 * given time. Adding stripes only takes device lock, while deleting stripes
335 * only takes hash lock.
336 */
337static void release_inactive_stripe_list(struct r5conf *conf,
338 struct list_head *temp_inactive_list,
339 int hash)
340{
341 int size;
342 bool do_wakeup = false;
343 unsigned long flags;
344
345 if (hash == NR_STRIPE_HASH_LOCKS) {
346 size = NR_STRIPE_HASH_LOCKS;
347 hash = NR_STRIPE_HASH_LOCKS - 1;
348 } else
349 size = 1;
350 while (size) {
351 struct list_head *list = &temp_inactive_list[size - 1];
352
353 /*
354 * We don't hold any lock here yet, get_active_stripe() might
355 * remove stripes from the list
356 */
357 if (!list_empty_careful(list)) {
358 spin_lock_irqsave(conf->hash_locks + hash, flags);
4bda556a
SL		 359 if (list_empty(conf->inactive_list + hash) &&
360 !list_empty(list))
361 atomic_dec(&conf->empty_inactive_list_nr);
566c09c5
SL		 362 list_splice_tail_init(list, conf->inactive_list + hash);
363 do_wakeup = true;
364 spin_unlock_irqrestore(conf->hash_locks + hash, flags);
365 }
366 size--;
367 hash--;
368 }
369
370 if (do_wakeup) {
371 wake_up(&conf->wait_for_stripe);
372 if (conf->retry_read_aligned)
373 md_wakeup_thread(conf->mddev->thread);
374 }
4eb788df
SL		 375}
376
773ca82f 377/* should hold conf->device_lock already */
566c09c5
SL		 378static int release_stripe_list(struct r5conf *conf,
379 struct list_head *temp_inactive_list)
773ca82f
SL		 380{
381 struct stripe_head *sh;
382 int count = 0;
383 struct llist_node *head;
384
385 head = llist_del_all(&conf->released_stripes);
d265d9dc 386 head = llist_reverse_order(head);
773ca82f 387 while (head) {
566c09c5
SL		 388 int hash;
389
773ca82f
SL		 390 sh = llist_entry(head, struct stripe_head, release_list);
391 head = llist_next(head);
392 /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
393 smp_mb();
394 clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
395 /*
396 * Don't worry the bit is set here, because if the bit is set
397 * again, the count is always > 1. This is true for
398 * STRIPE_ON_UNPLUG_LIST bit too.
399 */
566c09c5
SL		 400 hash = sh->hash_lock_index;
401 __release_stripe(conf, sh, &temp_inactive_list[hash]);
773ca82f
SL		 402 count++;
403 }
404
405 return count;
406}
407
1da177e4
LT		 408static void release_stripe(struct stripe_head *sh)
409{
d1688a6d 410 struct r5conf *conf = sh->raid_conf;
1da177e4 411 unsigned long flags;
566c09c5
SL		 412 struct list_head list;
413 int hash;
773ca82f 414 bool wakeup;
16a53ecc 415
ad4068de 416 if (unlikely(!conf->mddev->thread) ||
417 test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
773ca82f
SL		 418 goto slow_path;
419 wakeup = llist_add(&sh->release_list, &conf->released_stripes);
420 if (wakeup)
421 md_wakeup_thread(conf->mddev->thread);
422 return;
423slow_path:
4eb788df 424 local_irq_save(flags);
773ca82f 425 /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
4eb788df 426 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
566c09c5
SL		 427 INIT_LIST_HEAD(&list);
428 hash = sh->hash_lock_index;
429 do_release_stripe(conf, sh, &list);
4eb788df 430 spin_unlock(&conf->device_lock);
566c09c5 431 release_inactive_stripe_list(conf, &list, hash);
4eb788df
SL		 432 }
433 local_irq_restore(flags);
1da177e4
LT		 434}
435
fccddba0 436static inline void remove_hash(struct stripe_head *sh)
1da177e4 437{
45b4233c
DW		 438 pr_debug("remove_hash(), stripe %llu\n",
439 (unsigned long long)sh->sector);
1da177e4 440
fccddba0 441 hlist_del_init(&sh->hash);
1da177e4
LT		 442}
443
d1688a6d 444static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
1da177e4 445{
fccddba0 446 struct hlist_head *hp = stripe_hash(conf, sh->sector);
1da177e4 447
45b4233c
DW		 448 pr_debug("insert_hash(), stripe %llu\n",
449 (unsigned long long)sh->sector);
1da177e4 450
fccddba0 451 hlist_add_head(&sh->hash, hp);
1da177e4
LT		 452}
453
454
455/* find an idle stripe, make sure it is unhashed, and return it. */
566c09c5 456static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash)
1da177e4
LT		 457{
458 struct stripe_head *sh = NULL;
459 struct list_head *first;
460
566c09c5 461 if (list_empty(conf->inactive_list + hash))
1da177e4 462 goto out;
566c09c5 463 first = (conf->inactive_list + hash)->next;
1da177e4
LT		 464 sh = list_entry(first, struct stripe_head, lru);
465 list_del_init(first);
466 remove_hash(sh);
467 atomic_inc(&conf->active_stripes);
566c09c5 468 BUG_ON(hash != sh->hash_lock_index);
4bda556a
SL		 469 if (list_empty(conf->inactive_list + hash))
470 atomic_inc(&conf->empty_inactive_list_nr);
1da177e4
LT		 471out:
472 return sh;
473}
474
e4e11e38 475static void shrink_buffers(struct stripe_head *sh)
1da177e4
LT		 476{
477 struct page *p;
478 int i;
e4e11e38 479 int num = sh->raid_conf->pool_size;
1da177e4 480
e4e11e38 481 for (i = 0; i < num ; i++) {
1da177e4
LT		 482 p = sh->dev[i].page;
483 if (!p)
484 continue;
485 sh->dev[i].page = NULL;
2d1f3b5d 486 put_page(p);
1da177e4
LT		 487 }
488}
489
e4e11e38 490static int grow_buffers(struct stripe_head *sh)
1da177e4
LT		 491{
492 int i;
e4e11e38 493 int num = sh->raid_conf->pool_size;
1da177e4 494
e4e11e38 495 for (i = 0; i < num; i++) {
1da177e4
LT		 496 struct page *page;
497
498 if (!(page = alloc_page(GFP_KERNEL))) {
499 return 1;
500 }
501 sh->dev[i].page = page;
502 }
503 return 0;
504}
505
784052ec 506static void raid5_build_block(struct stripe_head *sh, int i, int previous);
d1688a6d 507static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
911d4ee8 508 struct stripe_head *sh);
1da177e4 509
b5663ba4 510static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
1da177e4 511{
d1688a6d 512 struct r5conf *conf = sh->raid_conf;
566c09c5 513 int i, seq;
1da177e4 514
78bafebd
ES		 515 BUG_ON(atomic_read(&sh->count) != 0);
516 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
600aa109 517 BUG_ON(stripe_operations_active(sh));
d84e0f10 518
45b4233c 519 pr_debug("init_stripe called, stripe %llu\n",
1da177e4
LT		 520 (unsigned long long)sh->sector);
521
522 remove_hash(sh);
566c09c5
SL		 523retry:
524 seq = read_seqcount_begin(&conf->gen_lock);
86b42c71 525 sh->generation = conf->generation - previous;
b5663ba4 526 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
1da177e4 527 sh->sector = sector;
911d4ee8 528 stripe_set_idx(sector, conf, previous, sh);
1da177e4
LT		 529 sh->state = 0;
530
7ecaa1e6
N		 531
532 for (i = sh->disks; i--; ) {
1da177e4
LT		 533 struct r5dev *dev = &sh->dev[i];
534
d84e0f10 535 if (dev->toread || dev->read || dev->towrite || dev->written ||
1da177e4 536 test_bit(R5_LOCKED, &dev->flags)) {
d84e0f10 537 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
1da177e4 538 (unsigned long long)sh->sector, i, dev->toread,
d84e0f10 539 dev->read, dev->towrite, dev->written,
1da177e4 540 test_bit(R5_LOCKED, &dev->flags));
8cfa7b0f 541 WARN_ON(1);
1da177e4
LT		 542 }
543 dev->flags = 0;
784052ec 544 raid5_build_block(sh, i, previous);
1da177e4 545 }
566c09c5
SL		 546 if (read_seqcount_retry(&conf->gen_lock, seq))
547 goto retry;
1da177e4 548 insert_hash(conf, sh);
851c30c9 549 sh->cpu = smp_processor_id();
1da177e4
LT		 550}
551
d1688a6d 552static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
86b42c71 553 short generation)
1da177e4
LT		 554{
555 struct stripe_head *sh;
556
45b4233c 557 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
b67bfe0d 558 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
86b42c71 559 if (sh->sector == sector && sh->generation == generation)
1da177e4 560 return sh;
45b4233c 561 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
1da177e4
LT		 562 return NULL;
563}
564
674806d6
N		 565/*
566 * Need to check if array has failed when deciding whether to:
567 * - start an array
568 * - remove non-faulty devices
569 * - add a spare
570 * - allow a reshape
571 * This determination is simple when no reshape is happening.
572 * However if there is a reshape, we need to carefully check
573 * both the before and after sections.
574 * This is because some failed devices may only affect one
575 * of the two sections, and some non-in_sync devices may
576 * be insync in the section most affected by failed devices.
577 */
908f4fbd 578static int calc_degraded(struct r5conf *conf)
674806d6 579{
908f4fbd 580 int degraded, degraded2;
674806d6 581 int i;
674806d6
N		 582
583 rcu_read_lock();
584 degraded = 0;
585 for (i = 0; i < conf->previous_raid_disks; i++) {
3cb03002 586 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
e5c86471
N		 587 if (rdev && test_bit(Faulty, &rdev->flags))
588 rdev = rcu_dereference(conf->disks[i].replacement);
674806d6
N		 589 if (!rdev || test_bit(Faulty, &rdev->flags))
590 degraded++;
591 else if (test_bit(In_sync, &rdev->flags))
592 ;
593 else
594 /* not in-sync or faulty.
595 * If the reshape increases the number of devices,
596 * this is being recovered by the reshape, so
597 * this 'previous' section is not in_sync.
598 * If the number of devices is being reduced however,
599 * the device can only be part of the array if
600 * we are reverting a reshape, so this section will
601 * be in-sync.
602 */
603 if (conf->raid_disks >= conf->previous_raid_disks)
604 degraded++;
605 }
606 rcu_read_unlock();
908f4fbd
N		 607 if (conf->raid_disks == conf->previous_raid_disks)
608 return degraded;
674806d6 609 rcu_read_lock();
908f4fbd 610 degraded2 = 0;
674806d6 611 for (i = 0; i < conf->raid_disks; i++) {
3cb03002 612 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
e5c86471
N		 613 if (rdev && test_bit(Faulty, &rdev->flags))
614 rdev = rcu_dereference(conf->disks[i].replacement);
674806d6 615 if (!rdev || test_bit(Faulty, &rdev->flags))
908f4fbd 616 degraded2++;
674806d6
N		 617 else if (test_bit(In_sync, &rdev->flags))
618 ;
619 else
620 /* not in-sync or faulty.
621 * If reshape increases the number of devices, this
622 * section has already been recovered, else it
623 * almost certainly hasn't.
624 */
625 if (conf->raid_disks <= conf->previous_raid_disks)
908f4fbd 626 degraded2++;
674806d6
N		 627 }
628 rcu_read_unlock();
908f4fbd
N		 629 if (degraded2 > degraded)
630 return degraded2;
631 return degraded;
632}
633
634static int has_failed(struct r5conf *conf)
635{
636 int degraded;
637
638 if (conf->mddev->reshape_position == MaxSector)
639 return conf->mddev->degraded > conf->max_degraded;
640
641 degraded = calc_degraded(conf);
674806d6
N		 642 if (degraded > conf->max_degraded)
643 return 1;
644 return 0;
645}
646
b5663ba4 647static struct stripe_head *
d1688a6d 648get_active_stripe(struct r5conf *conf, sector_t sector,
a8c906ca 649 int previous, int noblock, int noquiesce)
1da177e4
LT		 650{
651 struct stripe_head *sh;
566c09c5 652 int hash = stripe_hash_locks_hash(sector);
1da177e4 653
45b4233c 654 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
1da177e4 655
566c09c5 656 spin_lock_irq(conf->hash_locks + hash);
1da177e4
LT		 657
658 do {
72626685 659 wait_event_lock_irq(conf->wait_for_stripe,
a8c906ca 660 conf->quiesce == 0 || noquiesce,
566c09c5 661 *(conf->hash_locks + hash));
86b42c71 662 sh = __find_stripe(conf, sector, conf->generation - previous);
1da177e4
LT		 663 if (!sh) {
664 if (!conf->inactive_blocked)
566c09c5 665 sh = get_free_stripe(conf, hash);
1da177e4
LT		 666 if (noblock && sh == NULL)
667 break;
668 if (!sh) {
669 conf->inactive_blocked = 1;
566c09c5
SL		 670 wait_event_lock_irq(
671 conf->wait_for_stripe,
672 !list_empty(conf->inactive_list + hash) &&
673 (atomic_read(&conf->active_stripes)
674 < (conf->max_nr_stripes * 3 / 4)
675 || !conf->inactive_blocked),
676 *(conf->hash_locks + hash));
1da177e4 677 conf->inactive_blocked = 0;
7da9d450 678 } else {
b5663ba4 679 init_stripe(sh, sector, previous);
7da9d450
N		 680 atomic_inc(&sh->count);
681 }
e240c183 682 } else if (!atomic_inc_not_zero(&sh->count)) {
6d183de4 683 spin_lock(&conf->device_lock);
e240c183 684 if (!atomic_read(&sh->count)) {
1da177e4
LT		 685 if (!test_bit(STRIPE_HANDLE, &sh->state))
686 atomic_inc(&conf->active_stripes);
5af9bef7
N		 687 BUG_ON(list_empty(&sh->lru) &&
688 !test_bit(STRIPE_EXPANDING, &sh->state));
16a53ecc 689 list_del_init(&sh->lru);
bfc90cb0
SL		 690 if (sh->group) {
691 sh->group->stripes_cnt--;
692 sh->group = NULL;
693 }
1da177e4 694 }
7da9d450 695 atomic_inc(&sh->count);
6d183de4 696 spin_unlock(&conf->device_lock);
1da177e4
LT		 697 }
698 } while (sh == NULL);
699
566c09c5 700 spin_unlock_irq(conf->hash_locks + hash);
1da177e4
LT		 701 return sh;
702}
703
05616be5
N		 704/* Determine if 'data_offset' or 'new_data_offset' should be used
705 * in this stripe_head.
706 */
707static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
708{
709 sector_t progress = conf->reshape_progress;
710 /* Need a memory barrier to make sure we see the value
711 * of conf->generation, or ->data_offset that was set before
712 * reshape_progress was updated.
713 */
714 smp_rmb();
715 if (progress == MaxSector)
716 return 0;
717 if (sh->generation == conf->generation - 1)
718 return 0;
719 /* We are in a reshape, and this is a new-generation stripe,
720 * so use new_data_offset.
721 */
722 return 1;
723}
724
6712ecf8
N		 725static void
726raid5_end_read_request(struct bio *bi, int error);
727static void
728raid5_end_write_request(struct bio *bi, int error);
91c00924 729
c4e5ac0a 730static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
91c00924 731{
d1688a6d 732 struct r5conf *conf = sh->raid_conf;
91c00924
DW		 733 int i, disks = sh->disks;
734
735 might_sleep();
736
737 for (i = disks; i--; ) {
738 int rw;
9a3e1101 739 int replace_only = 0;
977df362
N		 740 struct bio *bi, *rbi;
741 struct md_rdev *rdev, *rrdev = NULL;
e9c7469b
TH		 742 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
743 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
744 rw = WRITE_FUA;
745 else
746 rw = WRITE;
9e444768 747 if (test_bit(R5_Discard, &sh->dev[i].flags))
620125f2 748 rw |= REQ_DISCARD;
e9c7469b 749 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
91c00924 750 rw = READ;
9a3e1101
N		 751 else if (test_and_clear_bit(R5_WantReplace,
752 &sh->dev[i].flags)) {
753 rw = WRITE;
754 replace_only = 1;
755 } else
91c00924 756 continue;
bc0934f0
SL		 757 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
758 rw |= REQ_SYNC;
91c00924
DW		 759
760 bi = &sh->dev[i].req;
977df362 761 rbi = &sh->dev[i].rreq; /* For writing to replacement */
91c00924 762
91c00924 763 rcu_read_lock();
9a3e1101 764 rrdev = rcu_dereference(conf->disks[i].replacement);
dd054fce
N		 765 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
766 rdev = rcu_dereference(conf->disks[i].rdev);
767 if (!rdev) {
768 rdev = rrdev;
769 rrdev = NULL;
770 }
9a3e1101
N		 771 if (rw & WRITE) {
772 if (replace_only)
773 rdev = NULL;
dd054fce
N		 774 if (rdev == rrdev)
775 /* We raced and saw duplicates */
776 rrdev = NULL;
9a3e1101 777 } else {
dd054fce 778 if (test_bit(R5_ReadRepl, &sh->dev[i].flags) && rrdev)
9a3e1101
N		 779 rdev = rrdev;
780 rrdev = NULL;
781 }
977df362 782
91c00924
DW		 783 if (rdev && test_bit(Faulty, &rdev->flags))
784 rdev = NULL;
785 if (rdev)
786 atomic_inc(&rdev->nr_pending);
977df362
N		 787 if (rrdev && test_bit(Faulty, &rrdev->flags))
788 rrdev = NULL;
789 if (rrdev)
790 atomic_inc(&rrdev->nr_pending);
91c00924
DW		 791 rcu_read_unlock();
792
73e92e51 793 /* We have already checked bad blocks for reads. Now
977df362
N		 794 * need to check for writes. We never accept write errors
795 * on the replacement, so we don't to check rrdev.
73e92e51
N		 796 */
797 while ((rw & WRITE) && rdev &&
798 test_bit(WriteErrorSeen, &rdev->flags)) {
799 sector_t first_bad;
800 int bad_sectors;
801 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
802 &first_bad, &bad_sectors);
803 if (!bad)
804 break;
805
806 if (bad < 0) {
807 set_bit(BlockedBadBlocks, &rdev->flags);
808 if (!conf->mddev->external &&
809 conf->mddev->flags) {
810 /* It is very unlikely, but we might
811 * still need to write out the
812 * bad block log - better give it
813 * a chance*/
814 md_check_recovery(conf->mddev);
815 }
1850753d 816 /*
817 * Because md_wait_for_blocked_rdev
818 * will dec nr_pending, we must
819 * increment it first.
820 */
821 atomic_inc(&rdev->nr_pending);
73e92e51
N		 822 md_wait_for_blocked_rdev(rdev, conf->mddev);
823 } else {
824 /* Acknowledged bad block - skip the write */
825 rdev_dec_pending(rdev, conf->mddev);
826 rdev = NULL;
827 }
828 }
829
91c00924 830 if (rdev) {
9a3e1101
N		 831 if (s->syncing || s->expanding || s->expanded
832 || s->replacing)
91c00924
DW		 833 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
834
2b7497f0
DW		 835 set_bit(STRIPE_IO_STARTED, &sh->state);
836
2f6db2a7 837 bio_reset(bi);
91c00924 838 bi->bi_bdev = rdev->bdev;
2f6db2a7
KO		 839 bi->bi_rw = rw;
840 bi->bi_end_io = (rw & WRITE)
841 ? raid5_end_write_request
842 : raid5_end_read_request;
843 bi->bi_private = sh;
844
91c00924 845 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
e46b272b 846 __func__, (unsigned long long)sh->sector,
91c00924
DW		 847 bi->bi_rw, i);
848 atomic_inc(&sh->count);
05616be5 849 if (use_new_offset(conf, sh))
4f024f37 850 bi->bi_iter.bi_sector = (sh->sector
05616be5
N		 851 + rdev->new_data_offset);
852 else
4f024f37 853 bi->bi_iter.bi_sector = (sh->sector
05616be5 854 + rdev->data_offset);
3f9e7c14 855 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
e59aa23f 856 bi->bi_rw |= REQ_NOMERGE;
3f9e7c14 857
4997b72e 858 bi->bi_vcnt = 1;
91c00924
DW		 859 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
860 bi->bi_io_vec[0].bv_offset = 0;
4f024f37 861 bi->bi_iter.bi_size = STRIPE_SIZE;
37c61ff3
SL		 862 /*
863 * If this is discard request, set bi_vcnt 0. We don't
864 * want to confuse SCSI because SCSI will replace payload
865 */
866 if (rw & REQ_DISCARD)
867 bi->bi_vcnt = 0;
977df362
N		 868 if (rrdev)
869 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
e3620a3a
JB		 870
871 if (conf->mddev->gendisk)
872 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
873 bi, disk_devt(conf->mddev->gendisk),
874 sh->dev[i].sector);
91c00924 875 generic_make_request(bi);
977df362
N		 876 }
877 if (rrdev) {
9a3e1101
N		 878 if (s->syncing || s->expanding || s->expanded
879 || s->replacing)
977df362
N		 880 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
881
882 set_bit(STRIPE_IO_STARTED, &sh->state);
883
2f6db2a7 884 bio_reset(rbi);
977df362 885 rbi->bi_bdev = rrdev->bdev;
2f6db2a7
KO		 886 rbi->bi_rw = rw;
887 BUG_ON(!(rw & WRITE));
888 rbi->bi_end_io = raid5_end_write_request;
889 rbi->bi_private = sh;
890
977df362
N		 891 pr_debug("%s: for %llu schedule op %ld on "
892 "replacement disc %d\n",
893 __func__, (unsigned long long)sh->sector,
894 rbi->bi_rw, i);
895 atomic_inc(&sh->count);
05616be5 896 if (use_new_offset(conf, sh))
4f024f37 897 rbi->bi_iter.bi_sector = (sh->sector
05616be5
N		 898 + rrdev->new_data_offset);
899 else
4f024f37 900 rbi->bi_iter.bi_sector = (sh->sector
05616be5 901 + rrdev->data_offset);
4997b72e 902 rbi->bi_vcnt = 1;
977df362
N		 903 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
904 rbi->bi_io_vec[0].bv_offset = 0;
4f024f37 905 rbi->bi_iter.bi_size = STRIPE_SIZE;
37c61ff3
SL		 906 /*
907 * If this is discard request, set bi_vcnt 0. We don't
908 * want to confuse SCSI because SCSI will replace payload
909 */
910 if (rw & REQ_DISCARD)
911 rbi->bi_vcnt = 0;
e3620a3a
JB		 912 if (conf->mddev->gendisk)
913 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
914 rbi, disk_devt(conf->mddev->gendisk),
915 sh->dev[i].sector);
977df362
N		 916 generic_make_request(rbi);
917 }
918 if (!rdev && !rrdev) {
b062962e 919 if (rw & WRITE)
91c00924
DW		 920 set_bit(STRIPE_DEGRADED, &sh->state);
921 pr_debug("skip op %ld on disc %d for sector %llu\n",
922 bi->bi_rw, i, (unsigned long long)sh->sector);
923 clear_bit(R5_LOCKED, &sh->dev[i].flags);
924 set_bit(STRIPE_HANDLE, &sh->state);
925 }
926 }
927}
928
929static struct dma_async_tx_descriptor *
930async_copy_data(int frombio, struct bio *bio, struct page *page,
931 sector_t sector, struct dma_async_tx_descriptor *tx)
932{
7988613b
KO		 933 struct bio_vec bvl;
934 struct bvec_iter iter;
91c00924 935 struct page *bio_page;
91c00924 936 int page_offset;
a08abd8c 937 struct async_submit_ctl submit;
0403e382 938 enum async_tx_flags flags = 0;
91c00924 939
4f024f37
KO		 940 if (bio->bi_iter.bi_sector >= sector)
941 page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512;
91c00924 942 else
4f024f37 943 page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512;
a08abd8c 944
0403e382
DW		 945 if (frombio)
946 flags |= ASYNC_TX_FENCE;
947 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
948
7988613b
KO		 949 bio_for_each_segment(bvl, bio, iter) {
950 int len = bvl.bv_len;
91c00924
DW		 951 int clen;
952 int b_offset = 0;
953
954 if (page_offset < 0) {
955 b_offset = -page_offset;
956 page_offset += b_offset;
957 len -= b_offset;
958 }
959
960 if (len > 0 && page_offset + len > STRIPE_SIZE)
961 clen = STRIPE_SIZE - page_offset;
962 else
963 clen = len;
964
965 if (clen > 0) {
7988613b
KO		 966 b_offset += bvl.bv_offset;
967 bio_page = bvl.bv_page;
91c00924
DW		 968 if (frombio)
969 tx = async_memcpy(page, bio_page, page_offset,
a08abd8c 970 b_offset, clen, &submit);
91c00924
DW		 971 else
972 tx = async_memcpy(bio_page, page, b_offset,
a08abd8c 973 page_offset, clen, &submit);
91c00924 974 }
a08abd8c
DW		 975 /* chain the operations */
976 submit.depend_tx = tx;
977
91c00924
DW		 978 if (clen < len) /* hit end of page */
979 break;
980 page_offset += len;
981 }
982
983 return tx;
984}
985
986static void ops_complete_biofill(void *stripe_head_ref)
987{
988 struct stripe_head *sh = stripe_head_ref;
989 struct bio *return_bi = NULL;
e4d84909 990 int i;
91c00924 991
e46b272b 992 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 993 (unsigned long long)sh->sector);
994
995 /* clear completed biofills */
996 for (i = sh->disks; i--; ) {
997 struct r5dev *dev = &sh->dev[i];
91c00924
DW		 998
999 /* acknowledge completion of a biofill operation */
e4d84909
DW		 1000 /* and check if we need to reply to a read request,
1001 * new R5_Wantfill requests are held off until
83de75cc 1002 * !STRIPE_BIOFILL_RUN
e4d84909
DW		 1003 */
1004 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
91c00924 1005 struct bio *rbi, *rbi2;
91c00924 1006
91c00924
DW		 1007 BUG_ON(!dev->read);
1008 rbi = dev->read;
1009 dev->read = NULL;
4f024f37 1010 while (rbi && rbi->bi_iter.bi_sector <
91c00924
DW		 1011 dev->sector + STRIPE_SECTORS) {
1012 rbi2 = r5_next_bio(rbi, dev->sector);
e7836bd6 1013 if (!raid5_dec_bi_active_stripes(rbi)) {
91c00924
DW		 1014 rbi->bi_next = return_bi;
1015 return_bi = rbi;
1016 }
91c00924
DW		 1017 rbi = rbi2;
1018 }
1019 }
1020 }
83de75cc 1021 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
91c00924
DW		 1022
1023 return_io(return_bi);
1024
e4d84909 1025 set_bit(STRIPE_HANDLE, &sh->state);
91c00924
DW		 1026 release_stripe(sh);
1027}
1028
1029static void ops_run_biofill(struct stripe_head *sh)
1030{
1031 struct dma_async_tx_descriptor *tx = NULL;
a08abd8c 1032 struct async_submit_ctl submit;
91c00924
DW		 1033 int i;
1034
e46b272b 1035 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1036 (unsigned long long)sh->sector);
1037
1038 for (i = sh->disks; i--; ) {
1039 struct r5dev *dev = &sh->dev[i];
1040 if (test_bit(R5_Wantfill, &dev->flags)) {
1041 struct bio *rbi;
b17459c0 1042 spin_lock_irq(&sh->stripe_lock);
91c00924
DW		 1043 dev->read = rbi = dev->toread;
1044 dev->toread = NULL;
b17459c0 1045 spin_unlock_irq(&sh->stripe_lock);
4f024f37 1046 while (rbi && rbi->bi_iter.bi_sector <
91c00924
DW		 1047 dev->sector + STRIPE_SECTORS) {
1048 tx = async_copy_data(0, rbi, dev->page,
1049 dev->sector, tx);
1050 rbi = r5_next_bio(rbi, dev->sector);
1051 }
1052 }
1053 }
1054
1055 atomic_inc(&sh->count);
a08abd8c
DW		 1056 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
1057 async_trigger_callback(&submit);
91c00924
DW		 1058}
1059
4e7d2c0a 1060static void mark_target_uptodate(struct stripe_head *sh, int target)
91c00924 1061{
4e7d2c0a 1062 struct r5dev *tgt;
91c00924 1063
4e7d2c0a
DW		 1064 if (target < 0)
1065 return;
91c00924 1066
4e7d2c0a 1067 tgt = &sh->dev[target];
91c00924
DW		 1068 set_bit(R5_UPTODATE, &tgt->flags);
1069 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1070 clear_bit(R5_Wantcompute, &tgt->flags);
4e7d2c0a
DW		 1071}
1072
ac6b53b6 1073static void ops_complete_compute(void *stripe_head_ref)
91c00924
DW		 1074{
1075 struct stripe_head *sh = stripe_head_ref;
91c00924 1076
e46b272b 1077 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1078 (unsigned long long)sh->sector);
1079
ac6b53b6 1080 /* mark the computed target(s) as uptodate */
4e7d2c0a 1081 mark_target_uptodate(sh, sh->ops.target);
ac6b53b6 1082 mark_target_uptodate(sh, sh->ops.target2);
4e7d2c0a 1083
ecc65c9b
DW		 1084 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
1085 if (sh->check_state == check_state_compute_run)
1086 sh->check_state = check_state_compute_result;
91c00924
DW		 1087 set_bit(STRIPE_HANDLE, &sh->state);
1088 release_stripe(sh);
1089}
1090
d6f38f31
DW		 1091/* return a pointer to the address conversion region of the scribble buffer */
1092static addr_conv_t *to_addr_conv(struct stripe_head *sh,
1093 struct raid5_percpu *percpu)
1094{
1095 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
1096}
1097
1098static struct dma_async_tx_descriptor *
1099ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 1100{
91c00924 1101 int disks = sh->disks;
d6f38f31 1102 struct page **xor_srcs = percpu->scribble;
91c00924
DW		 1103 int target = sh->ops.target;
1104 struct r5dev *tgt = &sh->dev[target];
1105 struct page *xor_dest = tgt->page;
1106 int count = 0;
1107 struct dma_async_tx_descriptor *tx;
a08abd8c 1108 struct async_submit_ctl submit;
91c00924
DW		 1109 int i;
1110
1111 pr_debug("%s: stripe %llu block: %d\n",
e46b272b 1112 __func__, (unsigned long long)sh->sector, target);
91c00924
DW		 1113 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1114
1115 for (i = disks; i--; )
1116 if (i != target)
1117 xor_srcs[count++] = sh->dev[i].page;
1118
1119 atomic_inc(&sh->count);
1120
0403e382 1121 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
ac6b53b6 1122 ops_complete_compute, sh, to_addr_conv(sh, percpu));
91c00924 1123 if (unlikely(count == 1))
a08abd8c 1124 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
91c00924 1125 else
a08abd8c 1126 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924 1127
91c00924
DW		 1128 return tx;
1129}
1130
ac6b53b6
DW		 1131/* set_syndrome_sources - populate source buffers for gen_syndrome
1132 * @srcs - (struct page *) array of size sh->disks
1133 * @sh - stripe_head to parse
1134 *
1135 * Populates srcs in proper layout order for the stripe and returns the
1136 * 'count' of sources to be used in a call to async_gen_syndrome. The P
1137 * destination buffer is recorded in srcs[count] and the Q destination
1138 * is recorded in srcs[count+1]].
1139 */
1140static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
1141{
1142 int disks = sh->disks;
1143 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1144 int d0_idx = raid6_d0(sh);
1145 int count;
1146 int i;
1147
1148 for (i = 0; i < disks; i++)
5dd33c9a 1149 srcs[i] = NULL;
ac6b53b6
DW		 1150
1151 count = 0;
1152 i = d0_idx;
1153 do {
1154 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1155
1156 srcs[slot] = sh->dev[i].page;
1157 i = raid6_next_disk(i, disks);
1158 } while (i != d0_idx);
ac6b53b6 1159
e4424fee 1160 return syndrome_disks;
ac6b53b6
DW		 1161}
1162
1163static struct dma_async_tx_descriptor *
1164ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
1165{
1166 int disks = sh->disks;
1167 struct page **blocks = percpu->scribble;
1168 int target;
1169 int qd_idx = sh->qd_idx;
1170 struct dma_async_tx_descriptor *tx;
1171 struct async_submit_ctl submit;
1172 struct r5dev *tgt;
1173 struct page *dest;
1174 int i;
1175 int count;
1176
1177 if (sh->ops.target < 0)
1178 target = sh->ops.target2;
1179 else if (sh->ops.target2 < 0)
1180 target = sh->ops.target;
91c00924 1181 else
ac6b53b6
DW		 1182 /* we should only have one valid target */
1183 BUG();
1184 BUG_ON(target < 0);
1185 pr_debug("%s: stripe %llu block: %d\n",
1186 __func__, (unsigned long long)sh->sector, target);
1187
1188 tgt = &sh->dev[target];
1189 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1190 dest = tgt->page;
1191
1192 atomic_inc(&sh->count);
1193
1194 if (target == qd_idx) {
1195 count = set_syndrome_sources(blocks, sh);
1196 blocks[count] = NULL; /* regenerating p is not necessary */
1197 BUG_ON(blocks[count+1] != dest); /* q should already be set */
0403e382
DW		 1198 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1199 ops_complete_compute, sh,
ac6b53b6
DW		 1200 to_addr_conv(sh, percpu));
1201 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1202 } else {
1203 /* Compute any data- or p-drive using XOR */
1204 count = 0;
1205 for (i = disks; i-- ; ) {
1206 if (i == target || i == qd_idx)
1207 continue;
1208 blocks[count++] = sh->dev[i].page;
1209 }
1210
0403e382
DW		 1211 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1212 NULL, ops_complete_compute, sh,
ac6b53b6
DW		 1213 to_addr_conv(sh, percpu));
1214 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1215 }
91c00924 1216
91c00924
DW		 1217 return tx;
1218}
1219
ac6b53b6
DW		 1220static struct dma_async_tx_descriptor *
1221ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1222{
1223 int i, count, disks = sh->disks;
1224 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1225 int d0_idx = raid6_d0(sh);
1226 int faila = -1, failb = -1;
1227 int target = sh->ops.target;
1228 int target2 = sh->ops.target2;
1229 struct r5dev *tgt = &sh->dev[target];
1230 struct r5dev *tgt2 = &sh->dev[target2];
1231 struct dma_async_tx_descriptor *tx;
1232 struct page **blocks = percpu->scribble;
1233 struct async_submit_ctl submit;
1234
1235 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1236 __func__, (unsigned long long)sh->sector, target, target2);
1237 BUG_ON(target < 0 || target2 < 0);
1238 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1239 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1240
6c910a78 1241 /* we need to open-code set_syndrome_sources to handle the
ac6b53b6
DW		 1242 * slot number conversion for 'faila' and 'failb'
1243 */
1244 for (i = 0; i < disks ; i++)
5dd33c9a 1245 blocks[i] = NULL;
ac6b53b6
DW		 1246 count = 0;
1247 i = d0_idx;
1248 do {
1249 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1250
1251 blocks[slot] = sh->dev[i].page;
1252
1253 if (i == target)
1254 faila = slot;
1255 if (i == target2)
1256 failb = slot;
1257 i = raid6_next_disk(i, disks);
1258 } while (i != d0_idx);
ac6b53b6
DW		 1259
1260 BUG_ON(faila == failb);
1261 if (failb < faila)
1262 swap(faila, failb);
1263 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1264 __func__, (unsigned long long)sh->sector, faila, failb);
1265
1266 atomic_inc(&sh->count);
1267
1268 if (failb == syndrome_disks+1) {
1269 /* Q disk is one of the missing disks */
1270 if (faila == syndrome_disks) {
1271 /* Missing P+Q, just recompute */
0403e382
DW		 1272 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1273 ops_complete_compute, sh,
1274 to_addr_conv(sh, percpu));
e4424fee 1275 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
ac6b53b6
DW		 1276 STRIPE_SIZE, &submit);
1277 } else {
1278 struct page *dest;
1279 int data_target;
1280 int qd_idx = sh->qd_idx;
1281
1282 /* Missing D+Q: recompute D from P, then recompute Q */
1283 if (target == qd_idx)
1284 data_target = target2;
1285 else
1286 data_target = target;
1287
1288 count = 0;
1289 for (i = disks; i-- ; ) {
1290 if (i == data_target || i == qd_idx)
1291 continue;
1292 blocks[count++] = sh->dev[i].page;
1293 }
1294 dest = sh->dev[data_target].page;
0403e382
DW		 1295 init_async_submit(&submit,
1296 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1297 NULL, NULL, NULL,
1298 to_addr_conv(sh, percpu));
ac6b53b6
DW		 1299 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1300 &submit);
1301
1302 count = set_syndrome_sources(blocks, sh);
0403e382
DW		 1303 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1304 ops_complete_compute, sh,
1305 to_addr_conv(sh, percpu));
ac6b53b6
DW		 1306 return async_gen_syndrome(blocks, 0, count+2,
1307 STRIPE_SIZE, &submit);
1308 }
ac6b53b6 1309 } else {
6c910a78
DW		 1310 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1311 ops_complete_compute, sh,
1312 to_addr_conv(sh, percpu));
1313 if (failb == syndrome_disks) {
1314 /* We're missing D+P. */
1315 return async_raid6_datap_recov(syndrome_disks+2,
1316 STRIPE_SIZE, faila,
1317 blocks, &submit);
1318 } else {
1319 /* We're missing D+D. */
1320 return async_raid6_2data_recov(syndrome_disks+2,
1321 STRIPE_SIZE, faila, failb,
1322 blocks, &submit);
1323 }
ac6b53b6
DW		 1324 }
1325}
1326
1327
91c00924
DW		 1328static void ops_complete_prexor(void *stripe_head_ref)
1329{
1330 struct stripe_head *sh = stripe_head_ref;
1331
e46b272b 1332 pr_debug("%s: stripe %llu\n", __func__,
91c00924 1333 (unsigned long long)sh->sector);
91c00924
DW		 1334}
1335
1336static struct dma_async_tx_descriptor *
d6f38f31
DW		 1337ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
1338 struct dma_async_tx_descriptor *tx)
91c00924 1339{
91c00924 1340 int disks = sh->disks;
d6f38f31 1341 struct page **xor_srcs = percpu->scribble;
91c00924 1342 int count = 0, pd_idx = sh->pd_idx, i;
a08abd8c 1343 struct async_submit_ctl submit;
91c00924
DW		 1344
1345 /* existing parity data subtracted */
1346 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1347
e46b272b 1348 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1349 (unsigned long long)sh->sector);
1350
1351 for (i = disks; i--; ) {
1352 struct r5dev *dev = &sh->dev[i];
1353 /* Only process blocks that are known to be uptodate */
d8ee0728 1354 if (test_bit(R5_Wantdrain, &dev->flags))
91c00924
DW		 1355 xor_srcs[count++] = dev->page;
1356 }
1357
0403e382 1358 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
d6f38f31 1359 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
a08abd8c 1360 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 1361
1362 return tx;
1363}
1364
1365static struct dma_async_tx_descriptor *
d8ee0728 1366ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
91c00924
DW		 1367{
1368 int disks = sh->disks;
d8ee0728 1369 int i;
91c00924 1370
e46b272b 1371 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1372 (unsigned long long)sh->sector);
1373
1374 for (i = disks; i--; ) {
1375 struct r5dev *dev = &sh->dev[i];
1376 struct bio *chosen;
91c00924 1377
d8ee0728 1378 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
91c00924
DW		 1379 struct bio *wbi;
1380
b17459c0 1381 spin_lock_irq(&sh->stripe_lock);
91c00924
DW		 1382 chosen = dev->towrite;
1383 dev->towrite = NULL;
1384 BUG_ON(dev->written);
1385 wbi = dev->written = chosen;
b17459c0 1386 spin_unlock_irq(&sh->stripe_lock);
91c00924 1387
4f024f37 1388 while (wbi && wbi->bi_iter.bi_sector <
91c00924 1389 dev->sector + STRIPE_SECTORS) {
e9c7469b
TH		 1390 if (wbi->bi_rw & REQ_FUA)
1391 set_bit(R5_WantFUA, &dev->flags);
bc0934f0
SL		 1392 if (wbi->bi_rw & REQ_SYNC)
1393 set_bit(R5_SyncIO, &dev->flags);
9e444768 1394 if (wbi->bi_rw & REQ_DISCARD)
620125f2 1395 set_bit(R5_Discard, &dev->flags);
9e444768 1396 else
620125f2
SL		 1397 tx = async_copy_data(1, wbi, dev->page,
1398 dev->sector, tx);
91c00924
DW		 1399 wbi = r5_next_bio(wbi, dev->sector);
1400 }
1401 }
1402 }
1403
1404 return tx;
1405}
1406
ac6b53b6 1407static void ops_complete_reconstruct(void *stripe_head_ref)
91c00924
DW		 1408{
1409 struct stripe_head *sh = stripe_head_ref;
ac6b53b6
DW		 1410 int disks = sh->disks;
1411 int pd_idx = sh->pd_idx;
1412 int qd_idx = sh->qd_idx;
1413 int i;
9e444768 1414 bool fua = false, sync = false, discard = false;
91c00924 1415
e46b272b 1416 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1417 (unsigned long long)sh->sector);
1418
bc0934f0 1419 for (i = disks; i--; ) {
e9c7469b 1420 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
bc0934f0 1421 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
9e444768 1422 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
bc0934f0 1423 }
e9c7469b 1424
91c00924
DW		 1425 for (i = disks; i--; ) {
1426 struct r5dev *dev = &sh->dev[i];
ac6b53b6 1427
e9c7469b 1428 if (dev->written || i == pd_idx || i == qd_idx) {
9e444768
SL		 1429 if (!discard)
1430 set_bit(R5_UPTODATE, &dev->flags);
e9c7469b
TH		 1431 if (fua)
1432 set_bit(R5_WantFUA, &dev->flags);
bc0934f0
SL		 1433 if (sync)
1434 set_bit(R5_SyncIO, &dev->flags);
e9c7469b 1435 }
91c00924
DW		 1436 }
1437
d8ee0728
DW		 1438 if (sh->reconstruct_state == reconstruct_state_drain_run)
1439 sh->reconstruct_state = reconstruct_state_drain_result;
1440 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1441 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1442 else {
1443 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1444 sh->reconstruct_state = reconstruct_state_result;
1445 }
91c00924
DW		 1446
1447 set_bit(STRIPE_HANDLE, &sh->state);
1448 release_stripe(sh);
1449}
1450
1451static void
ac6b53b6
DW		 1452ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1453 struct dma_async_tx_descriptor *tx)
91c00924 1454{
91c00924 1455 int disks = sh->disks;
d6f38f31 1456 struct page **xor_srcs = percpu->scribble;
a08abd8c 1457 struct async_submit_ctl submit;
91c00924
DW		 1458 int count = 0, pd_idx = sh->pd_idx, i;
1459 struct page *xor_dest;
d8ee0728 1460 int prexor = 0;
91c00924 1461 unsigned long flags;
91c00924 1462
e46b272b 1463 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1464 (unsigned long long)sh->sector);
1465
620125f2
SL		 1466 for (i = 0; i < sh->disks; i++) {
1467 if (pd_idx == i)
1468 continue;
1469 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1470 break;
1471 }
1472 if (i >= sh->disks) {
1473 atomic_inc(&sh->count);
620125f2
SL		 1474 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1475 ops_complete_reconstruct(sh);
1476 return;
1477 }
91c00924
DW		 1478 /* check if prexor is active which means only process blocks
1479 * that are part of a read-modify-write (written)
1480 */
d8ee0728
DW		 1481 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1482 prexor = 1;
91c00924
DW		 1483 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1484 for (i = disks; i--; ) {
1485 struct r5dev *dev = &sh->dev[i];
1486 if (dev->written)
1487 xor_srcs[count++] = dev->page;
1488 }
1489 } else {
1490 xor_dest = sh->dev[pd_idx].page;
1491 for (i = disks; i--; ) {
1492 struct r5dev *dev = &sh->dev[i];
1493 if (i != pd_idx)
1494 xor_srcs[count++] = dev->page;
1495 }
1496 }
1497
91c00924
DW		 1498 /* 1/ if we prexor'd then the dest is reused as a source
1499 * 2/ if we did not prexor then we are redoing the parity
1500 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1501 * for the synchronous xor case
1502 */
88ba2aa5 1503 flags = ASYNC_TX_ACK |
91c00924
DW		 1504 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1505
1506 atomic_inc(&sh->count);
1507
ac6b53b6 1508 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
d6f38f31 1509 to_addr_conv(sh, percpu));
a08abd8c
DW		 1510 if (unlikely(count == 1))
1511 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1512 else
1513 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
91c00924
DW		 1514}
1515
ac6b53b6
DW		 1516static void
1517ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1518 struct dma_async_tx_descriptor *tx)
1519{
1520 struct async_submit_ctl submit;
1521 struct page **blocks = percpu->scribble;
620125f2 1522 int count, i;
ac6b53b6
DW		 1523
1524 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1525
620125f2
SL		 1526 for (i = 0; i < sh->disks; i++) {
1527 if (sh->pd_idx == i || sh->qd_idx == i)
1528 continue;
1529 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1530 break;
1531 }
1532 if (i >= sh->disks) {
1533 atomic_inc(&sh->count);
620125f2
SL		 1534 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1535 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1536 ops_complete_reconstruct(sh);
1537 return;
1538 }
1539
ac6b53b6
DW		 1540 count = set_syndrome_sources(blocks, sh);
1541
1542 atomic_inc(&sh->count);
1543
1544 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1545 sh, to_addr_conv(sh, percpu));
1546 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
91c00924
DW		 1547}
1548
1549static void ops_complete_check(void *stripe_head_ref)
1550{
1551 struct stripe_head *sh = stripe_head_ref;
91c00924 1552
e46b272b 1553 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1554 (unsigned long long)sh->sector);
1555
ecc65c9b 1556 sh->check_state = check_state_check_result;
91c00924
DW		 1557 set_bit(STRIPE_HANDLE, &sh->state);
1558 release_stripe(sh);
1559}
1560
ac6b53b6 1561static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
91c00924 1562{
91c00924 1563 int disks = sh->disks;
ac6b53b6
DW		 1564 int pd_idx = sh->pd_idx;
1565 int qd_idx = sh->qd_idx;
1566 struct page *xor_dest;
d6f38f31 1567 struct page **xor_srcs = percpu->scribble;
91c00924 1568 struct dma_async_tx_descriptor *tx;
a08abd8c 1569 struct async_submit_ctl submit;
ac6b53b6
DW		 1570 int count;
1571 int i;
91c00924 1572
e46b272b 1573 pr_debug("%s: stripe %llu\n", __func__,
91c00924
DW		 1574 (unsigned long long)sh->sector);
1575
ac6b53b6
DW		 1576 count = 0;
1577 xor_dest = sh->dev[pd_idx].page;
1578 xor_srcs[count++] = xor_dest;
91c00924 1579 for (i = disks; i--; ) {
ac6b53b6
DW		 1580 if (i == pd_idx || i == qd_idx)
1581 continue;
1582 xor_srcs[count++] = sh->dev[i].page;
91c00924
DW		 1583 }
1584
d6f38f31
DW		 1585 init_async_submit(&submit, 0, NULL, NULL, NULL,
1586 to_addr_conv(sh, percpu));
099f53cb 1587 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
a08abd8c 1588 &sh->ops.zero_sum_result, &submit);
91c00924 1589
91c00924 1590 atomic_inc(&sh->count);
a08abd8c
DW		 1591 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1592 tx = async_trigger_callback(&submit);
91c00924
DW		 1593}
1594
ac6b53b6
DW		 1595static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1596{
1597 struct page **srcs = percpu->scribble;
1598 struct async_submit_ctl submit;
1599 int count;
1600
1601 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1602 (unsigned long long)sh->sector, checkp);
1603
1604 count = set_syndrome_sources(srcs, sh);
1605 if (!checkp)
1606 srcs[count] = NULL;
91c00924 1607
91c00924 1608 atomic_inc(&sh->count);
ac6b53b6
DW		 1609 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1610 sh, to_addr_conv(sh, percpu));
1611 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1612 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
91c00924
DW		 1613}
1614
51acbcec 1615static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
91c00924
DW		 1616{
1617 int overlap_clear = 0, i, disks = sh->disks;
1618 struct dma_async_tx_descriptor *tx = NULL;
d1688a6d 1619 struct r5conf *conf = sh->raid_conf;
ac6b53b6 1620 int level = conf->level;
d6f38f31
DW		 1621 struct raid5_percpu *percpu;
1622 unsigned long cpu;
91c00924 1623
d6f38f31
DW		 1624 cpu = get_cpu();
1625 percpu = per_cpu_ptr(conf->percpu, cpu);
83de75cc 1626 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
91c00924
DW		 1627 ops_run_biofill(sh);
1628 overlap_clear++;
1629 }
1630
7b3a871e 1631 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
ac6b53b6
DW		 1632 if (level < 6)
1633 tx = ops_run_compute5(sh, percpu);
1634 else {
1635 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1636 tx = ops_run_compute6_1(sh, percpu);
1637 else
1638 tx = ops_run_compute6_2(sh, percpu);
1639 }
1640 /* terminate the chain if reconstruct is not set to be run */
1641 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
7b3a871e
DW		 1642 async_tx_ack(tx);
1643 }
91c00924 1644
600aa109 1645 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
d6f38f31 1646 tx = ops_run_prexor(sh, percpu, tx);
91c00924 1647
600aa109 1648 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
d8ee0728 1649 tx = ops_run_biodrain(sh, tx);
91c00924
DW		 1650 overlap_clear++;
1651 }
1652
ac6b53b6
DW		 1653 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1654 if (level < 6)
1655 ops_run_reconstruct5(sh, percpu, tx);
1656 else
1657 ops_run_reconstruct6(sh, percpu, tx);
1658 }
91c00924 1659
ac6b53b6
DW		 1660 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1661 if (sh->check_state == check_state_run)
1662 ops_run_check_p(sh, percpu);
1663 else if (sh->check_state == check_state_run_q)
1664 ops_run_check_pq(sh, percpu, 0);
1665 else if (sh->check_state == check_state_run_pq)
1666 ops_run_check_pq(sh, percpu, 1);
1667 else
1668 BUG();
1669 }
91c00924 1670
91c00924
DW		 1671 if (overlap_clear)
1672 for (i = disks; i--; ) {
1673 struct r5dev *dev = &sh->dev[i];
1674 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1675 wake_up(&sh->raid_conf->wait_for_overlap);
1676 }
d6f38f31 1677 put_cpu();
91c00924
DW		 1678}
1679
566c09c5 1680static int grow_one_stripe(struct r5conf *conf, int hash)
1da177e4
LT		 1681{
1682 struct stripe_head *sh;
6ce32846 1683 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
3f294f4f
N		 1684 if (!sh)
1685 return 0;
6ce32846 1686
3f294f4f 1687 sh->raid_conf = conf;
3f294f4f 1688
b17459c0
SL		 1689 spin_lock_init(&sh->stripe_lock);
1690
e4e11e38
N		 1691 if (grow_buffers(sh)) {
1692 shrink_buffers(sh);
3f294f4f
N		 1693 kmem_cache_free(conf->slab_cache, sh);
1694 return 0;
1695 }
566c09c5 1696 sh->hash_lock_index = hash;
3f294f4f
N		 1697 /* we just created an active stripe so... */
1698 atomic_set(&sh->count, 1);
1699 atomic_inc(&conf->active_stripes);
1700 INIT_LIST_HEAD(&sh->lru);
1701 release_stripe(sh);
1702 return 1;
1703}
1704
d1688a6d 1705static int grow_stripes(struct r5conf *conf, int num)
3f294f4f 1706{
e18b890b 1707 struct kmem_cache *sc;
5e5e3e78 1708 int devs = max(conf->raid_disks, conf->previous_raid_disks);
566c09c5 1709 int hash;
1da177e4 1710
f4be6b43
N		 1711 if (conf->mddev->gendisk)
1712 sprintf(conf->cache_name[0],
1713 "raid%d-%s", conf->level, mdname(conf->mddev));
1714 else
1715 sprintf(conf->cache_name[0],
1716 "raid%d-%p", conf->level, conf->mddev);
1717 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1718
ad01c9e3
N		 1719 conf->active_name = 0;
1720 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1da177e4 1721 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
20c2df83 1722 0, 0, NULL);
1da177e4
LT		 1723 if (!sc)
1724 return 1;
1725 conf->slab_cache = sc;
ad01c9e3 1726 conf->pool_size = devs;
566c09c5
SL		 1727 hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
1728 while (num--) {
1729 if (!grow_one_stripe(conf, hash))
1da177e4 1730 return 1;
566c09c5
SL		 1731 conf->max_nr_stripes++;
1732 hash = (hash + 1) % NR_STRIPE_HASH_LOCKS;
1733 }
1da177e4
LT		 1734 return 0;
1735}
29269553 1736
d6f38f31
DW		 1737/**
1738 * scribble_len - return the required size of the scribble region
1739 * @num - total number of disks in the array
1740 *
1741 * The size must be enough to contain:
1742 * 1/ a struct page pointer for each device in the array +2
1743 * 2/ room to convert each entry in (1) to its corresponding dma
1744 * (dma_map_page()) or page (page_address()) address.
1745 *
1746 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1747 * calculate over all devices (not just the data blocks), using zeros in place
1748 * of the P and Q blocks.
1749 */
1750static size_t scribble_len(int num)
1751{
1752 size_t len;
1753
1754 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1755
1756 return len;
1757}
1758
d1688a6d 1759static int resize_stripes(struct r5conf *conf, int newsize)
ad01c9e3
N		 1760{
1761 /* Make all the stripes able to hold 'newsize' devices.
1762 * New slots in each stripe get 'page' set to a new page.
1763 *
1764 * This happens in stages:
1765 * 1/ create a new kmem_cache and allocate the required number of
1766 * stripe_heads.
83f0d77a 1767 * 2/ gather all the old stripe_heads and transfer the pages across
ad01c9e3
N		 1768 * to the new stripe_heads. This will have the side effect of
1769 * freezing the array as once all stripe_heads have been collected,
1770 * no IO will be possible. Old stripe heads are freed once their
1771 * pages have been transferred over, and the old kmem_cache is
1772 * freed when all stripes are done.
1773 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1774 * we simple return a failre status - no need to clean anything up.
1775 * 4/ allocate new pages for the new slots in the new stripe_heads.
1776 * If this fails, we don't bother trying the shrink the
1777 * stripe_heads down again, we just leave them as they are.
1778 * As each stripe_head is processed the new one is released into
1779 * active service.
1780 *
1781 * Once step2 is started, we cannot afford to wait for a write,
1782 * so we use GFP_NOIO allocations.
1783 */
1784 struct stripe_head *osh, *nsh;
1785 LIST_HEAD(newstripes);
1786 struct disk_info *ndisks;
d6f38f31 1787 unsigned long cpu;
b5470dc5 1788 int err;
e18b890b 1789 struct kmem_cache *sc;
ad01c9e3 1790 int i;
566c09c5 1791 int hash, cnt;
ad01c9e3
N		 1792
1793 if (newsize <= conf->pool_size)
1794 return 0; /* never bother to shrink */
1795
b5470dc5
DW		 1796 err = md_allow_write(conf->mddev);
1797 if (err)
1798 return err;
2a2275d6 1799
ad01c9e3
N		 1800 /* Step 1 */
1801 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1802 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
20c2df83 1803 0, 0, NULL);
ad01c9e3
N		 1804 if (!sc)
1805 return -ENOMEM;
1806
1807 for (i = conf->max_nr_stripes; i; i--) {
6ce32846 1808 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
ad01c9e3
N		 1809 if (!nsh)
1810 break;
1811
ad01c9e3 1812 nsh->raid_conf = conf;
cb13ff69 1813 spin_lock_init(&nsh->stripe_lock);
ad01c9e3
N		 1814
1815 list_add(&nsh->lru, &newstripes);
1816 }
1817 if (i) {
1818 /* didn't get enough, give up */
1819 while (!list_empty(&newstripes)) {
1820 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1821 list_del(&nsh->lru);
1822 kmem_cache_free(sc, nsh);
1823 }
1824 kmem_cache_destroy(sc);
1825 return -ENOMEM;
1826 }
1827 /* Step 2 - Must use GFP_NOIO now.
1828 * OK, we have enough stripes, start collecting inactive
1829 * stripes and copying them over
1830 */
566c09c5
SL		 1831 hash = 0;
1832 cnt = 0;
ad01c9e3 1833 list_for_each_entry(nsh, &newstripes, lru) {
566c09c5
SL		 1834 lock_device_hash_lock(conf, hash);
1835 wait_event_cmd(conf->wait_for_stripe,
1836 !list_empty(conf->inactive_list + hash),
1837 unlock_device_hash_lock(conf, hash),
1838 lock_device_hash_lock(conf, hash));
1839 osh = get_free_stripe(conf, hash);
1840 unlock_device_hash_lock(conf, hash);
ad01c9e3
N		 1841 atomic_set(&nsh->count, 1);
1842 for(i=0; i<conf->pool_size; i++)
1843 nsh->dev[i].page = osh->dev[i].page;
1844 for( ; i<newsize; i++)
1845 nsh->dev[i].page = NULL;
566c09c5 1846 nsh->hash_lock_index = hash;
ad01c9e3 1847 kmem_cache_free(conf->slab_cache, osh);
566c09c5
SL		 1848 cnt++;
1849 if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +
1850 !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
1851 hash++;
1852 cnt = 0;
1853 }
ad01c9e3
N		 1854 }
1855 kmem_cache_destroy(conf->slab_cache);
1856
1857 /* Step 3.
1858 * At this point, we are holding all the stripes so the array
1859 * is completely stalled, so now is a good time to resize
d6f38f31 1860 * conf->disks and the scribble region
ad01c9e3
N		 1861 */
1862 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1863 if (ndisks) {
1864 for (i=0; i<conf->raid_disks; i++)
1865 ndisks[i] = conf->disks[i];
1866 kfree(conf->disks);
1867 conf->disks = ndisks;
1868 } else
1869 err = -ENOMEM;
1870
d6f38f31
DW		 1871 get_online_cpus();
1872 conf->scribble_len = scribble_len(newsize);
1873 for_each_present_cpu(cpu) {
1874 struct raid5_percpu *percpu;
1875 void *scribble;
1876
1877 percpu = per_cpu_ptr(conf->percpu, cpu);
1878 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1879
1880 if (scribble) {
1881 kfree(percpu->scribble);
1882 percpu->scribble = scribble;
1883 } else {
1884 err = -ENOMEM;
1885 break;
1886 }
1887 }
1888 put_online_cpus();
1889
ad01c9e3
N		 1890 /* Step 4, return new stripes to service */
1891 while(!list_empty(&newstripes)) {
1892 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1893 list_del_init(&nsh->lru);
d6f38f31 1894
ad01c9e3
N		 1895 for (i=conf->raid_disks; i < newsize; i++)
1896 if (nsh->dev[i].page == NULL) {
1897 struct page *p = alloc_page(GFP_NOIO);
1898 nsh->dev[i].page = p;
1899 if (!p)
1900 err = -ENOMEM;
1901 }
1902 release_stripe(nsh);
1903 }
1904 /* critical section pass, GFP_NOIO no longer needed */
1905
1906 conf->slab_cache = sc;
1907 conf->active_name = 1-conf->active_name;
1908 conf->pool_size = newsize;
1909 return err;
1910}
1da177e4 1911
566c09c5 1912static int drop_one_stripe(struct r5conf *conf, int hash)
1da177e4
LT		 1913{
1914 struct stripe_head *sh;
1915
566c09c5
SL		 1916 spin_lock_irq(conf->hash_locks + hash);
1917 sh = get_free_stripe(conf, hash);
1918 spin_unlock_irq(conf->hash_locks + hash);
3f294f4f
N		 1919 if (!sh)
1920 return 0;
78bafebd 1921 BUG_ON(atomic_read(&sh->count));
e4e11e38 1922 shrink_buffers(sh);
3f294f4f
N		 1923 kmem_cache_free(conf->slab_cache, sh);
1924 atomic_dec(&conf->active_stripes);
1925 return 1;
1926}
1927
d1688a6d 1928static void shrink_stripes(struct r5conf *conf)
3f294f4f 1929{
566c09c5
SL		 1930 int hash;
1931 for (hash = 0; hash < NR_STRIPE_HASH_LOCKS; hash++)
1932 while (drop_one_stripe(conf, hash))
1933 ;
3f294f4f 1934
29fc7e3e
N		 1935 if (conf->slab_cache)
1936 kmem_cache_destroy(conf->slab_cache);
1da177e4
LT		 1937 conf->slab_cache = NULL;
1938}
1939
6712ecf8 1940static void raid5_end_read_request(struct bio * bi, int error)
1da177e4 1941{
99c0fb5f 1942 struct stripe_head *sh = bi->bi_private;
d1688a6d 1943 struct r5conf *conf = sh->raid_conf;
7ecaa1e6 1944 int disks = sh->disks, i;
1da177e4 1945 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
d6950432 1946 char b[BDEVNAME_SIZE];
dd054fce 1947 struct md_rdev *rdev = NULL;
05616be5 1948 sector_t s;
1da177e4
LT		 1949
1950 for (i=0 ; i<disks; i++)
1951 if (bi == &sh->dev[i].req)
1952 break;
1953
45b4233c
DW		 1954 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1955 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1da177e4
LT		 1956 uptodate);
1957 if (i == disks) {
1958 BUG();
6712ecf8 1959 return;
1da177e4 1960 }
14a75d3e 1961 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
dd054fce
N		 1962 /* If replacement finished while this request was outstanding,
1963 * 'replacement' might be NULL already.
1964 * In that case it moved down to 'rdev'.
1965 * rdev is not removed until all requests are finished.
1966 */
14a75d3e 1967 rdev = conf->disks[i].replacement;
dd054fce 1968 if (!rdev)
14a75d3e 1969 rdev = conf->disks[i].rdev;
1da177e4 1970
05616be5
N		 1971 if (use_new_offset(conf, sh))
1972 s = sh->sector + rdev->new_data_offset;
1973 else
1974 s = sh->sector + rdev->data_offset;
1da177e4 1975 if (uptodate) {
1da177e4 1976 set_bit(R5_UPTODATE, &sh->dev[i].flags);
4e5314b5 1977 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
14a75d3e
N		 1978 /* Note that this cannot happen on a
1979 * replacement device. We just fail those on
1980 * any error
1981 */
8bda470e
CD		 1982 printk_ratelimited(
1983 KERN_INFO
1984 "md/raid:%s: read error corrected"
1985 " (%lu sectors at %llu on %s)\n",
1986 mdname(conf->mddev), STRIPE_SECTORS,
05616be5 1987 (unsigned long long)s,
8bda470e 1988 bdevname(rdev->bdev, b));
ddd5115f 1989 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
4e5314b5
N		 1990 clear_bit(R5_ReadError, &sh->dev[i].flags);
1991 clear_bit(R5_ReWrite, &sh->dev[i].flags);
3f9e7c14 1992 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
1993 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1994
14a75d3e
N		 1995 if (atomic_read(&rdev->read_errors))
1996 atomic_set(&rdev->read_errors, 0);
1da177e4 1997 } else {
14a75d3e 1998 const char *bdn = bdevname(rdev->bdev, b);
ba22dcbf 1999 int retry = 0;
2e8ac303 2000 int set_bad = 0;
d6950432 2001
1da177e4 2002 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
d6950432 2003 atomic_inc(&rdev->read_errors);
14a75d3e
N		 2004 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2005 printk_ratelimited(
2006 KERN_WARNING
2007 "md/raid:%s: read error on replacement device "
2008 "(sector %llu on %s).\n",
2009 mdname(conf->mddev),
05616be5 2010 (unsigned long long)s,
14a75d3e 2011 bdn);
2e8ac303 2012 else if (conf->mddev->degraded >= conf->max_degraded) {
2013 set_bad = 1;
8bda470e
CD		 2014 printk_ratelimited(
2015 KERN_WARNING
2016 "md/raid:%s: read error not correctable "
2017 "(sector %llu on %s).\n",
2018 mdname(conf->mddev),
05616be5 2019 (unsigned long long)s,
8bda470e 2020 bdn);
2e8ac303 2021 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
4e5314b5 2022 /* Oh, no!!! */
2e8ac303 2023 set_bad = 1;
8bda470e
CD		 2024 printk_ratelimited(
2025 KERN_WARNING
2026 "md/raid:%s: read error NOT corrected!! "
2027 "(sector %llu on %s).\n",
2028 mdname(conf->mddev),
05616be5 2029 (unsigned long long)s,
8bda470e 2030 bdn);
2e8ac303 2031 } else if (atomic_read(&rdev->read_errors)
ba22dcbf 2032 > conf->max_nr_stripes)
14f8d26b 2033 printk(KERN_WARNING
0c55e022 2034 "md/raid:%s: Too many read errors, failing device %s.\n",
d6950432 2035 mdname(conf->mddev), bdn);
ba22dcbf
N		 2036 else
2037 retry = 1;
edfa1f65
BY		 2038 if (set_bad && test_bit(In_sync, &rdev->flags)
2039 && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2040 retry = 1;
ba22dcbf 2041 if (retry)
3f9e7c14 2042 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
2043 set_bit(R5_ReadError, &sh->dev[i].flags);
2044 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2045 } else
2046 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
ba22dcbf 2047 else {
4e5314b5
N		 2048 clear_bit(R5_ReadError, &sh->dev[i].flags);
2049 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2e8ac303 2050 if (!(set_bad
2051 && test_bit(In_sync, &rdev->flags)
2052 && rdev_set_badblocks(
2053 rdev, sh->sector, STRIPE_SECTORS, 0)))
2054 md_error(conf->mddev, rdev);
ba22dcbf 2055 }
1da177e4 2056 }
14a75d3e 2057 rdev_dec_pending(rdev, conf->mddev);
1da177e4
LT		 2058 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2059 set_bit(STRIPE_HANDLE, &sh->state);
2060 release_stripe(sh);
1da177e4
LT		 2061}
2062
d710e138 2063static void raid5_end_write_request(struct bio *bi, int error)
1da177e4 2064{
99c0fb5f 2065 struct stripe_head *sh = bi->bi_private;
d1688a6d 2066 struct r5conf *conf = sh->raid_conf;
7ecaa1e6 2067 int disks = sh->disks, i;
977df362 2068 struct md_rdev *uninitialized_var(rdev);
1da177e4 2069 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
b84db560
N		 2070 sector_t first_bad;
2071 int bad_sectors;
977df362 2072 int replacement = 0;
1da177e4 2073
977df362
N		 2074 for (i = 0 ; i < disks; i++) {
2075 if (bi == &sh->dev[i].req) {
2076 rdev = conf->disks[i].rdev;
1da177e4 2077 break;
977df362
N		 2078 }
2079 if (bi == &sh->dev[i].rreq) {
2080 rdev = conf->disks[i].replacement;
dd054fce
N		 2081 if (rdev)
2082 replacement = 1;
2083 else
2084 /* rdev was removed and 'replacement'
2085 * replaced it. rdev is not removed
2086 * until all requests are finished.
2087 */
2088 rdev = conf->disks[i].rdev;
977df362
N		 2089 break;
2090 }
2091 }
45b4233c 2092 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1da177e4
LT		 2093 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2094 uptodate);
2095 if (i == disks) {
2096 BUG();
6712ecf8 2097 return;
1da177e4
LT		 2098 }
2099
977df362
N		 2100 if (replacement) {
2101 if (!uptodate)
2102 md_error(conf->mddev, rdev);
2103 else if (is_badblock(rdev, sh->sector,
2104 STRIPE_SECTORS,
2105 &first_bad, &bad_sectors))
2106 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
2107 } else {
2108 if (!uptodate) {
9f97e4b1 2109 set_bit(STRIPE_DEGRADED, &sh->state);
977df362
N		 2110 set_bit(WriteErrorSeen, &rdev->flags);
2111 set_bit(R5_WriteError, &sh->dev[i].flags);
3a6de292
N		 2112 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2113 set_bit(MD_RECOVERY_NEEDED,
2114 &rdev->mddev->recovery);
977df362
N		 2115 } else if (is_badblock(rdev, sh->sector,
2116 STRIPE_SECTORS,
c0b32972 2117 &first_bad, &bad_sectors)) {
977df362 2118 set_bit(R5_MadeGood, &sh->dev[i].flags);
c0b32972
N		 2119 if (test_bit(R5_ReadError, &sh->dev[i].flags))
2120 /* That was a successful write so make
2121 * sure it looks like we already did
2122 * a re-write.
2123 */
2124 set_bit(R5_ReWrite, &sh->dev[i].flags);
2125 }
977df362
N		 2126 }
2127 rdev_dec_pending(rdev, conf->mddev);
1da177e4 2128
977df362
N		 2129 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
2130 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1da177e4 2131 set_bit(STRIPE_HANDLE, &sh->state);
c04be0aa 2132 release_stripe(sh);
1da177e4
LT		 2133}
2134
784052ec 2135static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1da177e4 2136
784052ec 2137static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1da177e4
LT		 2138{
2139 struct r5dev *dev = &sh->dev[i];
2140
2141 bio_init(&dev->req);
2142 dev->req.bi_io_vec = &dev->vec;
2143 dev->req.bi_vcnt++;
2144 dev->req.bi_max_vecs++;
1da177e4 2145 dev->req.bi_private = sh;
995c4275 2146 dev->vec.bv_page = dev->page;
1da177e4 2147
977df362
N		 2148 bio_init(&dev->rreq);
2149 dev->rreq.bi_io_vec = &dev->rvec;
2150 dev->rreq.bi_vcnt++;
2151 dev->rreq.bi_max_vecs++;
2152 dev->rreq.bi_private = sh;
2153 dev->rvec.bv_page = dev->page;
2154
1da177e4 2155 dev->flags = 0;
784052ec 2156 dev->sector = compute_blocknr(sh, i, previous);
1da177e4
LT		 2157}
2158
fd01b88c 2159static void error(struct mddev *mddev, struct md_rdev *rdev)
1da177e4
LT		 2160{
2161 char b[BDEVNAME_SIZE];
d1688a6d 2162 struct r5conf *conf = mddev->private;
908f4fbd 2163 unsigned long flags;
0c55e022 2164 pr_debug("raid456: error called\n");
1da177e4 2165
908f4fbd
N		 2166 spin_lock_irqsave(&conf->device_lock, flags);
2167 clear_bit(In_sync, &rdev->flags);
2168 mddev->degraded = calc_degraded(conf);
2169 spin_unlock_irqrestore(&conf->device_lock, flags);
2170 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2171
de393cde 2172 set_bit(Blocked, &rdev->flags);
6f8d0c77
N		 2173 set_bit(Faulty, &rdev->flags);
2174 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2175 printk(KERN_ALERT
2176 "md/raid:%s: Disk failure on %s, disabling device.\n"
2177 "md/raid:%s: Operation continuing on %d devices.\n",
2178 mdname(mddev),
2179 bdevname(rdev->bdev, b),
2180 mdname(mddev),
2181 conf->raid_disks - mddev->degraded);
16a53ecc 2182}
1da177e4
LT		 2183
2184/*
2185 * Input: a 'big' sector number,
2186 * Output: index of the data and parity disk, and the sector # in them.
2187 */
d1688a6d 2188static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
911d4ee8
N		 2189 int previous, int *dd_idx,
2190 struct stripe_head *sh)
1da177e4 2191{
6e3b96ed 2192 sector_t stripe, stripe2;
35f2a591 2193 sector_t chunk_number;
1da177e4 2194 unsigned int chunk_offset;
911d4ee8 2195 int pd_idx, qd_idx;
67cc2b81 2196 int ddf_layout = 0;
1da177e4 2197 sector_t new_sector;
e183eaed
N		 2198 int algorithm = previous ? conf->prev_algo
2199 : conf->algorithm;
09c9e5fa
AN		 2200 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2201 : conf->chunk_sectors;
112bf897
N		 2202 int raid_disks = previous ? conf->previous_raid_disks
2203 : conf->raid_disks;
2204 int data_disks = raid_disks - conf->max_degraded;
1da177e4
LT		 2205
2206 /* First compute the information on this sector */
2207
2208 /*
2209 * Compute the chunk number and the sector offset inside the chunk
2210 */
2211 chunk_offset = sector_div(r_sector, sectors_per_chunk);
2212 chunk_number = r_sector;
1da177e4
LT		 2213
2214 /*
2215 * Compute the stripe number
2216 */
35f2a591
N		 2217 stripe = chunk_number;
2218 *dd_idx = sector_div(stripe, data_disks);
6e3b96ed 2219 stripe2 = stripe;
1da177e4
LT		 2220 /*
2221 * Select the parity disk based on the user selected algorithm.
2222 */
84789554 2223 pd_idx = qd_idx = -1;
16a53ecc
N		 2224 switch(conf->level) {
2225 case 4:
911d4ee8 2226 pd_idx = data_disks;
16a53ecc
N		 2227 break;
2228 case 5:
e183eaed 2229 switch (algorithm) {
1da177e4 2230 case ALGORITHM_LEFT_ASYMMETRIC:
6e3b96ed 2231 pd_idx = data_disks - sector_div(stripe2, raid_disks);
911d4ee8 2232 if (*dd_idx >= pd_idx)
1da177e4
LT		 2233 (*dd_idx)++;
2234 break;
2235 case ALGORITHM_RIGHT_ASYMMETRIC:
6e3b96ed 2236 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8 2237 if (*dd_idx >= pd_idx)
1da177e4
LT		 2238 (*dd_idx)++;
2239 break;
2240 case ALGORITHM_LEFT_SYMMETRIC:
6e3b96ed 2241 pd_idx = data_disks - sector_div(stripe2, raid_disks);
911d4ee8 2242 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1da177e4
LT		 2243 break;
2244 case ALGORITHM_RIGHT_SYMMETRIC:
6e3b96ed 2245 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8 2246 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1da177e4 2247 break;
99c0fb5f
N		 2248 case ALGORITHM_PARITY_0:
2249 pd_idx = 0;
2250 (*dd_idx)++;
2251 break;
2252 case ALGORITHM_PARITY_N:
2253 pd_idx = data_disks;
2254 break;
1da177e4 2255 default:
99c0fb5f 2256 BUG();
16a53ecc
N		 2257 }
2258 break;
2259 case 6:
2260
e183eaed 2261 switch (algorithm) {
16a53ecc 2262 case ALGORITHM_LEFT_ASYMMETRIC:
6e3b96ed 2263 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
911d4ee8
N		 2264 qd_idx = pd_idx + 1;
2265 if (pd_idx == raid_disks-1) {
99c0fb5f 2266 (*dd_idx)++; /* Q D D D P */
911d4ee8
N		 2267 qd_idx = 0;
2268 } else if (*dd_idx >= pd_idx)
16a53ecc
N		 2269 (*dd_idx) += 2; /* D D P Q D */
2270 break;
2271 case ALGORITHM_RIGHT_ASYMMETRIC:
6e3b96ed 2272 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8
N		 2273 qd_idx = pd_idx + 1;
2274 if (pd_idx == raid_disks-1) {
99c0fb5f 2275 (*dd_idx)++; /* Q D D D P */
911d4ee8
N		 2276 qd_idx = 0;
2277 } else if (*dd_idx >= pd_idx)
16a53ecc
N		 2278 (*dd_idx) += 2; /* D D P Q D */
2279 break;
2280 case ALGORITHM_LEFT_SYMMETRIC:
6e3b96ed 2281 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
911d4ee8
N		 2282 qd_idx = (pd_idx + 1) % raid_disks;
2283 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
16a53ecc
N		 2284 break;
2285 case ALGORITHM_RIGHT_SYMMETRIC:
6e3b96ed 2286 pd_idx = sector_div(stripe2, raid_disks);
911d4ee8
N		 2287 qd_idx = (pd_idx + 1) % raid_disks;
2288 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
16a53ecc 2289 break;
99c0fb5f
N		 2290
2291 case ALGORITHM_PARITY_0:
2292 pd_idx = 0;
2293 qd_idx = 1;
2294 (*dd_idx) += 2;
2295 break;
2296 case ALGORITHM_PARITY_N:
2297 pd_idx = data_disks;
2298 qd_idx = data_disks + 1;
2299 break;
2300
2301 case ALGORITHM_ROTATING_ZERO_RESTART:
2302 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2303 * of blocks for computing Q is different.
2304 */
6e3b96ed 2305 pd_idx = sector_div(stripe2, raid_disks);
99c0fb5f
N		 2306 qd_idx = pd_idx + 1;
2307 if (pd_idx == raid_disks-1) {
2308 (*dd_idx)++; /* Q D D D P */
2309 qd_idx = 0;
2310 } else if (*dd_idx >= pd_idx)
2311 (*dd_idx) += 2; /* D D P Q D */
67cc2b81 2312 ddf_layout = 1;
99c0fb5f
N		 2313 break;
2314
2315 case ALGORITHM_ROTATING_N_RESTART:
2316 /* Same a left_asymmetric, by first stripe is
2317 * D D D P Q rather than
2318 * Q D D D P
2319 */
6e3b96ed
N		 2320 stripe2 += 1;
2321 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
99c0fb5f
N		 2322 qd_idx = pd_idx + 1;
2323 if (pd_idx == raid_disks-1) {
2324 (*dd_idx)++; /* Q D D D P */
2325 qd_idx = 0;
2326 } else if (*dd_idx >= pd_idx)
2327 (*dd_idx) += 2; /* D D P Q D */
67cc2b81 2328 ddf_layout = 1;
99c0fb5f
N		 2329 break;
2330
2331 case ALGORITHM_ROTATING_N_CONTINUE:
2332 /* Same as left_symmetric but Q is before P */
6e3b96ed 2333 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
99c0fb5f
N		 2334 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2335 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
67cc2b81 2336 ddf_layout = 1;
99c0fb5f
N		 2337 break;
2338
2339 case ALGORITHM_LEFT_ASYMMETRIC_6:
2340 /* RAID5 left_asymmetric, with Q on last device */
6e3b96ed 2341 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 2342 if (*dd_idx >= pd_idx)
2343 (*dd_idx)++;
2344 qd_idx = raid_disks - 1;
2345 break;
2346
2347 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6e3b96ed 2348 pd_idx = sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 2349 if (*dd_idx >= pd_idx)
2350 (*dd_idx)++;
2351 qd_idx = raid_disks - 1;
2352 break;
2353
2354 case ALGORITHM_LEFT_SYMMETRIC_6:
6e3b96ed 2355 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 2356 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2357 qd_idx = raid_disks - 1;
2358 break;
2359
2360 case ALGORITHM_RIGHT_SYMMETRIC_6:
6e3b96ed 2361 pd_idx = sector_div(stripe2, raid_disks-1);
99c0fb5f
N		 2362 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2363 qd_idx = raid_disks - 1;
2364 break;
2365
2366 case ALGORITHM_PARITY_0_6:
2367 pd_idx = 0;
2368 (*dd_idx)++;
2369 qd_idx = raid_disks - 1;
2370 break;
2371
16a53ecc 2372 default:
99c0fb5f 2373 BUG();
16a53ecc
N		 2374 }
2375 break;
1da177e4
LT		 2376 }
2377
911d4ee8
N		 2378 if (sh) {
2379 sh->pd_idx = pd_idx;
2380 sh->qd_idx = qd_idx;
67cc2b81 2381 sh->ddf_layout = ddf_layout;
911d4ee8 2382 }
1da177e4
LT		 2383 /*
2384 * Finally, compute the new sector number
2385 */
2386 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2387 return new_sector;
2388}
2389
2390
784052ec 2391static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
1da177e4 2392{
d1688a6d 2393 struct r5conf *conf = sh->raid_conf;
b875e531
N		 2394 int raid_disks = sh->disks;
2395 int data_disks = raid_disks - conf->max_degraded;
1da177e4 2396 sector_t new_sector = sh->sector, check;
09c9e5fa
AN		 2397 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2398 : conf->chunk_sectors;
e183eaed
N		 2399 int algorithm = previous ? conf->prev_algo
2400 : conf->algorithm;
1da177e4
LT		 2401 sector_t stripe;
2402 int chunk_offset;
35f2a591
N		 2403 sector_t chunk_number;
2404 int dummy1, dd_idx = i;
1da177e4 2405 sector_t r_sector;
911d4ee8 2406 struct stripe_head sh2;
1da177e4 2407
16a53ecc 2408
1da177e4
LT		 2409 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2410 stripe = new_sector;
1da177e4 2411
16a53ecc
N		 2412 if (i == sh->pd_idx)
2413 return 0;
2414 switch(conf->level) {
2415 case 4: break;
2416 case 5:
e183eaed 2417 switch (algorithm) {
1da177e4
LT		 2418 case ALGORITHM_LEFT_ASYMMETRIC:
2419 case ALGORITHM_RIGHT_ASYMMETRIC:
2420 if (i > sh->pd_idx)
2421 i--;
2422 break;
2423 case ALGORITHM_LEFT_SYMMETRIC:
2424 case ALGORITHM_RIGHT_SYMMETRIC:
2425 if (i < sh->pd_idx)
2426 i += raid_disks;
2427 i -= (sh->pd_idx + 1);
2428 break;
99c0fb5f
N		 2429 case ALGORITHM_PARITY_0:
2430 i -= 1;
2431 break;
2432 case ALGORITHM_PARITY_N:
2433 break;
1da177e4 2434 default:
99c0fb5f 2435 BUG();
16a53ecc
N		 2436 }
2437 break;
2438 case 6:
d0dabf7e 2439 if (i == sh->qd_idx)
16a53ecc 2440 return 0; /* It is the Q disk */
e183eaed 2441 switch (algorithm) {
16a53ecc
N		 2442 case ALGORITHM_LEFT_ASYMMETRIC:
2443 case ALGORITHM_RIGHT_ASYMMETRIC:
99c0fb5f
N		 2444 case ALGORITHM_ROTATING_ZERO_RESTART:
2445 case ALGORITHM_ROTATING_N_RESTART:
2446 if (sh->pd_idx == raid_disks-1)
2447 i--; /* Q D D D P */
16a53ecc
N		 2448 else if (i > sh->pd_idx)
2449 i -= 2; /* D D P Q D */
2450 break;
2451 case ALGORITHM_LEFT_SYMMETRIC:
2452 case ALGORITHM_RIGHT_SYMMETRIC:
2453 if (sh->pd_idx == raid_disks-1)
2454 i--; /* Q D D D P */
2455 else {
2456 /* D D P Q D */
2457 if (i < sh->pd_idx)
2458 i += raid_disks;
2459 i -= (sh->pd_idx + 2);
2460 }
2461 break;
99c0fb5f
N		 2462 case ALGORITHM_PARITY_0:
2463 i -= 2;
2464 break;
2465 case ALGORITHM_PARITY_N:
2466 break;
2467 case ALGORITHM_ROTATING_N_CONTINUE:
e4424fee 2468 /* Like left_symmetric, but P is before Q */
99c0fb5f
N		 2469 if (sh->pd_idx == 0)
2470 i--; /* P D D D Q */
e4424fee
N		 2471 else {
2472 /* D D Q P D */
2473 if (i < sh->pd_idx)
2474 i += raid_disks;
2475 i -= (sh->pd_idx + 1);
2476 }
99c0fb5f
N		 2477 break;
2478 case ALGORITHM_LEFT_ASYMMETRIC_6:
2479 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2480 if (i > sh->pd_idx)
2481 i--;
2482 break;
2483 case ALGORITHM_LEFT_SYMMETRIC_6:
2484 case ALGORITHM_RIGHT_SYMMETRIC_6:
2485 if (i < sh->pd_idx)
2486 i += data_disks + 1;
2487 i -= (sh->pd_idx + 1);
2488 break;
2489 case ALGORITHM_PARITY_0_6:
2490 i -= 1;
2491 break;
16a53ecc 2492 default:
99c0fb5f 2493 BUG();
16a53ecc
N		 2494 }
2495 break;
1da177e4
LT		 2496 }
2497
2498 chunk_number = stripe * data_disks + i;
35f2a591 2499 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
1da177e4 2500
112bf897 2501 check = raid5_compute_sector(conf, r_sector,
784052ec 2502 previous, &dummy1, &sh2);
911d4ee8
N		 2503 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2504 || sh2.qd_idx != sh->qd_idx) {
0c55e022
N		 2505 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2506 mdname(conf->mddev));
1da177e4
LT		 2507 return 0;
2508 }
2509 return r_sector;
2510}
2511
2512
600aa109 2513static void
c0f7bddb 2514schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
600aa109 2515 int rcw, int expand)
e33129d8
DW		 2516{
2517 int i, pd_idx = sh->pd_idx, disks = sh->disks;
d1688a6d 2518 struct r5conf *conf = sh->raid_conf;
c0f7bddb 2519 int level = conf->level;
e33129d8
DW		 2520
2521 if (rcw) {
e33129d8
DW		 2522
2523 for (i = disks; i--; ) {
2524 struct r5dev *dev = &sh->dev[i];
2525
2526 if (dev->towrite) {
2527 set_bit(R5_LOCKED, &dev->flags);
d8ee0728 2528 set_bit(R5_Wantdrain, &dev->flags);
e33129d8
DW		 2529 if (!expand)
2530 clear_bit(R5_UPTODATE, &dev->flags);
600aa109 2531 s->locked++;
e33129d8
DW		 2532 }
2533 }
ce7d363a
N		 2534 /* if we are not expanding this is a proper write request, and
2535 * there will be bios with new data to be drained into the
2536 * stripe cache
2537 */
2538 if (!expand) {
2539 if (!s->locked)
2540 /* False alarm, nothing to do */
2541 return;
2542 sh->reconstruct_state = reconstruct_state_drain_run;
2543 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2544 } else
2545 sh->reconstruct_state = reconstruct_state_run;
2546
2547 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2548
c0f7bddb 2549 if (s->locked + conf->max_degraded == disks)
8b3e6cdc 2550 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
c0f7bddb 2551 atomic_inc(&conf->pending_full_writes);
e33129d8 2552 } else {
c0f7bddb 2553 BUG_ON(level == 6);
e33129d8
DW		 2554 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2555 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2556
e33129d8
DW		 2557 for (i = disks; i--; ) {
2558 struct r5dev *dev = &sh->dev[i];
2559 if (i == pd_idx)
2560 continue;
2561
e33129d8
DW		 2562 if (dev->towrite &&
2563 (test_bit(R5_UPTODATE, &dev->flags) ||
d8ee0728
DW		 2564 test_bit(R5_Wantcompute, &dev->flags))) {
2565 set_bit(R5_Wantdrain, &dev->flags);
e33129d8
DW		 2566 set_bit(R5_LOCKED, &dev->flags);
2567 clear_bit(R5_UPTODATE, &dev->flags);
600aa109 2568 s->locked++;
e33129d8
DW		 2569 }
2570 }
ce7d363a
N		 2571 if (!s->locked)
2572 /* False alarm - nothing to do */
2573 return;
2574 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2575 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2576 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2577 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
e33129d8
DW		 2578 }
2579
c0f7bddb 2580 /* keep the parity disk(s) locked while asynchronous operations
e33129d8
DW		 2581 * are in flight
2582 */
2583 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2584 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
600aa109 2585 s->locked++;
e33129d8 2586
c0f7bddb
YT		 2587 if (level == 6) {
2588 int qd_idx = sh->qd_idx;
2589 struct r5dev *dev = &sh->dev[qd_idx];
2590
2591 set_bit(R5_LOCKED, &dev->flags);
2592 clear_bit(R5_UPTODATE, &dev->flags);
2593 s->locked++;
2594 }
2595
600aa109 2596 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
e46b272b 2597 __func__, (unsigned long long)sh->sector,
600aa109 2598 s->locked, s->ops_request);
e33129d8 2599}
16a53ecc 2600
1da177e4
LT		 2601/*
2602 * Each stripe/dev can have one or more bion attached.
16a53ecc 2603 * toread/towrite point to the first in a chain.
1da177e4
LT		 2604 * The bi_next chain must be in order.
2605 */
2606static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2607{
2608 struct bio **bip;
d1688a6d 2609 struct r5conf *conf = sh->raid_conf;
72626685 2610 int firstwrite=0;
1da177e4 2611
cbe47ec5 2612 pr_debug("adding bi b#%llu to stripe s#%llu\n",
4f024f37 2613 (unsigned long long)bi->bi_iter.bi_sector,
1da177e4
LT		 2614 (unsigned long long)sh->sector);
2615
b17459c0
SL		 2616 /*
2617 * If several bio share a stripe. The bio bi_phys_segments acts as a
2618 * reference count to avoid race. The reference count should already be
2619 * increased before this function is called (for example, in
2620 * make_request()), so other bio sharing this stripe will not free the
2621 * stripe. If a stripe is owned by one stripe, the stripe lock will
2622 * protect it.
2623 */
2624 spin_lock_irq(&sh->stripe_lock);
72626685 2625 if (forwrite) {
1da177e4 2626 bip = &sh->dev[dd_idx].towrite;
7eaf7e8e 2627 if (*bip == NULL)
72626685
N		 2628 firstwrite = 1;
2629 } else
1da177e4 2630 bip = &sh->dev[dd_idx].toread;
4f024f37
KO		 2631 while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
2632 if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
1da177e4
LT		 2633 goto overlap;
2634 bip = & (*bip)->bi_next;
2635 }
4f024f37 2636 if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
1da177e4
LT		 2637 goto overlap;
2638
78bafebd 2639 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
1da177e4
LT		 2640 if (*bip)
2641 bi->bi_next = *bip;
2642 *bip = bi;
e7836bd6 2643 raid5_inc_bi_active_stripes(bi);
72626685 2644
1da177e4
LT		 2645 if (forwrite) {
2646 /* check if page is covered */
2647 sector_t sector = sh->dev[dd_idx].sector;
2648 for (bi=sh->dev[dd_idx].towrite;
2649 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
4f024f37 2650 bi && bi->bi_iter.bi_sector <= sector;
1da177e4 2651 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
f73a1c7d
KO		 2652 if (bio_end_sector(bi) >= sector)
2653 sector = bio_end_sector(bi);
1da177e4
LT		 2654 }
2655 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2656 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2657 }
cbe47ec5
N		 2658
2659 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
4f024f37 2660 (unsigned long long)(*bip)->bi_iter.bi_sector,
cbe47ec5 2661 (unsigned long long)sh->sector, dd_idx);
b97390ae 2662 spin_unlock_irq(&sh->stripe_lock);
cbe47ec5
N		 2663
2664 if (conf->mddev->bitmap && firstwrite) {
2665 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2666 STRIPE_SECTORS, 0);
2667 sh->bm_seq = conf->seq_flush+1;
2668 set_bit(STRIPE_BIT_DELAY, &sh->state);
2669 }
1da177e4
LT		 2670 return 1;
2671
2672 overlap:
2673 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
b17459c0 2674 spin_unlock_irq(&sh->stripe_lock);
1da177e4
LT		 2675 return 0;
2676}
2677
d1688a6d 2678static void end_reshape(struct r5conf *conf);
29269553 2679
d1688a6d 2680static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
911d4ee8 2681 struct stripe_head *sh)
ccfcc3c1 2682{
784052ec 2683 int sectors_per_chunk =
09c9e5fa 2684 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
911d4ee8 2685 int dd_idx;
2d2063ce 2686 int chunk_offset = sector_div(stripe, sectors_per_chunk);
112bf897 2687 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2d2063ce 2688
112bf897
N		 2689 raid5_compute_sector(conf,
2690 stripe * (disks - conf->max_degraded)
b875e531 2691 *sectors_per_chunk + chunk_offset,
112bf897 2692 previous,
911d4ee8 2693 &dd_idx, sh);
ccfcc3c1
N		 2694}
2695
a4456856 2696static void
d1688a6d 2697handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
a4456856
DW		 2698 struct stripe_head_state *s, int disks,
2699 struct bio **return_bi)
2700{
2701 int i;
2702 for (i = disks; i--; ) {
2703 struct bio *bi;
2704 int bitmap_end = 0;
2705
2706 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
3cb03002 2707 struct md_rdev *rdev;
a4456856
DW		 2708 rcu_read_lock();
2709 rdev = rcu_dereference(conf->disks[i].rdev);
2710 if (rdev && test_bit(In_sync, &rdev->flags))
7f0da59b
N		 2711 atomic_inc(&rdev->nr_pending);
2712 else
2713 rdev = NULL;
a4456856 2714 rcu_read_unlock();
7f0da59b
N		 2715 if (rdev) {
2716 if (!rdev_set_badblocks(
2717 rdev,
2718 sh->sector,
2719 STRIPE_SECTORS, 0))
2720 md_error(conf->mddev, rdev);
2721 rdev_dec_pending(rdev, conf->mddev);
2722 }
a4456856 2723 }
b17459c0 2724 spin_lock_irq(&sh->stripe_lock);
a4456856
DW		 2725 /* fail all writes first */
2726 bi = sh->dev[i].towrite;
2727 sh->dev[i].towrite = NULL;
b17459c0 2728 spin_unlock_irq(&sh->stripe_lock);
1ed850f3 2729 if (bi)
a4456856 2730 bitmap_end = 1;
a4456856
DW		 2731
2732 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2733 wake_up(&conf->wait_for_overlap);
2734
4f024f37 2735 while (bi && bi->bi_iter.bi_sector <
a4456856
DW		 2736 sh->dev[i].sector + STRIPE_SECTORS) {
2737 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2738 clear_bit(BIO_UPTODATE, &bi->bi_flags);
e7836bd6 2739 if (!raid5_dec_bi_active_stripes(bi)) {
a4456856
DW		 2740 md_write_end(conf->mddev);
2741 bi->bi_next = *return_bi;
2742 *return_bi = bi;
2743 }
2744 bi = nextbi;
2745 }
7eaf7e8e
SL		 2746 if (bitmap_end)
2747 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2748 STRIPE_SECTORS, 0, 0);
2749 bitmap_end = 0;
a4456856
DW		 2750 /* and fail all 'written' */
2751 bi = sh->dev[i].written;
2752 sh->dev[i].written = NULL;
2753 if (bi) bitmap_end = 1;
4f024f37 2754 while (bi && bi->bi_iter.bi_sector <
a4456856
DW		 2755 sh->dev[i].sector + STRIPE_SECTORS) {
2756 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2757 clear_bit(BIO_UPTODATE, &bi->bi_flags);
e7836bd6 2758 if (!raid5_dec_bi_active_stripes(bi)) {
a4456856
DW		 2759 md_write_end(conf->mddev);
2760 bi->bi_next = *return_bi;
2761 *return_bi = bi;
2762 }
2763 bi = bi2;
2764 }
2765
b5e98d65
DW		 2766 /* fail any reads if this device is non-operational and
2767 * the data has not reached the cache yet.
2768 */
2769 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2770 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2771 test_bit(R5_ReadError, &sh->dev[i].flags))) {
143c4d05 2772 spin_lock_irq(&sh->stripe_lock);
a4456856
DW		 2773 bi = sh->dev[i].toread;
2774 sh->dev[i].toread = NULL;
143c4d05 2775 spin_unlock_irq(&sh->stripe_lock);
a4456856
DW		 2776 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2777 wake_up(&conf->wait_for_overlap);
4f024f37 2778 while (bi && bi->bi_iter.bi_sector <
a4456856
DW		 2779 sh->dev[i].sector + STRIPE_SECTORS) {
2780 struct bio *nextbi =
2781 r5_next_bio(bi, sh->dev[i].sector);
2782 clear_bit(BIO_UPTODATE, &bi->bi_flags);
e7836bd6 2783 if (!raid5_dec_bi_active_stripes(bi)) {
a4456856
DW		 2784 bi->bi_next = *return_bi;
2785 *return_bi = bi;
2786 }
2787 bi = nextbi;
2788 }
2789 }
a4456856
DW		 2790 if (bitmap_end)
2791 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2792 STRIPE_SECTORS, 0, 0);
8cfa7b0f
N		 2793 /* If we were in the middle of a write the parity block might
2794 * still be locked - so just clear all R5_LOCKED flags
2795 */
2796 clear_bit(R5_LOCKED, &sh->dev[i].flags);
a4456856
DW		 2797 }
2798
8b3e6cdc
DW		 2799 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2800 if (atomic_dec_and_test(&conf->pending_full_writes))
2801 md_wakeup_thread(conf->mddev->thread);
a4456856
DW		 2802}
2803
7f0da59b 2804static void
d1688a6d 2805handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
7f0da59b
N		 2806 struct stripe_head_state *s)
2807{
2808 int abort = 0;
2809 int i;
2810
7f0da59b 2811 clear_bit(STRIPE_SYNCING, &sh->state);
f8dfcffd
N		 2812 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
2813 wake_up(&conf->wait_for_overlap);
7f0da59b 2814 s->syncing = 0;
9a3e1101 2815 s->replacing = 0;
7f0da59b 2816 /* There is nothing more to do for sync/check/repair.
18b9837e
N		 2817 * Don't even need to abort as that is handled elsewhere
2818 * if needed, and not always wanted e.g. if there is a known
2819 * bad block here.
9a3e1101 2820 * For recover/replace we need to record a bad block on all
7f0da59b
N		 2821 * non-sync devices, or abort the recovery
2822 */
18b9837e
N		 2823 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
2824 /* During recovery devices cannot be removed, so
2825 * locking and refcounting of rdevs is not needed
2826 */
2827 for (i = 0; i < conf->raid_disks; i++) {
2828 struct md_rdev *rdev = conf->disks[i].rdev;
2829 if (rdev
2830 && !test_bit(Faulty, &rdev->flags)
2831 && !test_bit(In_sync, &rdev->flags)
2832 && !rdev_set_badblocks(rdev, sh->sector,
2833 STRIPE_SECTORS, 0))
2834 abort = 1;
2835 rdev = conf->disks[i].replacement;
2836 if (rdev
2837 && !test_bit(Faulty, &rdev->flags)
2838 && !test_bit(In_sync, &rdev->flags)
2839 && !rdev_set_badblocks(rdev, sh->sector,
2840 STRIPE_SECTORS, 0))
2841 abort = 1;
2842 }
2843 if (abort)
2844 conf->recovery_disabled =
2845 conf->mddev->recovery_disabled;
7f0da59b 2846 }
18b9837e 2847 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
7f0da59b
N		 2848}
2849
9a3e1101
N		 2850static int want_replace(struct stripe_head *sh, int disk_idx)
2851{
2852 struct md_rdev *rdev;
2853 int rv = 0;
2854 /* Doing recovery so rcu locking not required */
2855 rdev = sh->raid_conf->disks[disk_idx].replacement;
2856 if (rdev
2857 && !test_bit(Faulty, &rdev->flags)
2858 && !test_bit(In_sync, &rdev->flags)
2859 && (rdev->recovery_offset <= sh->sector
2860 || rdev->mddev->recovery_cp <= sh->sector))
2861 rv = 1;
2862
2863 return rv;
2864}
2865
93b3dbce 2866/* fetch_block - checks the given member device to see if its data needs
1fe797e6
DW		 2867 * to be read or computed to satisfy a request.
2868 *
2869 * Returns 1 when no more member devices need to be checked, otherwise returns
93b3dbce 2870 * 0 to tell the loop in handle_stripe_fill to continue
f38e1219 2871 */
93b3dbce
N		 2872static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
2873 int disk_idx, int disks)
a4456856 2874{
5599becc 2875 struct r5dev *dev = &sh->dev[disk_idx];
f2b3b44d
N		 2876 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
2877 &sh->dev[s->failed_num[1]] };
5599becc 2878
93b3dbce 2879 /* is the data in this block needed, and can we get it? */
5599becc
YT		 2880 if (!test_bit(R5_LOCKED, &dev->flags) &&
2881 !test_bit(R5_UPTODATE, &dev->flags) &&
2882 (dev->toread ||
2883 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2884 s->syncing || s->expanding ||
9a3e1101 2885 (s->replacing && want_replace(sh, disk_idx)) ||
5d35e09c
N		 2886 (s->failed >= 1 && fdev[0]->toread) ||
2887 (s->failed >= 2 && fdev[1]->toread) ||
93b3dbce
N		 2888 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
2889 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
2890 (sh->raid_conf->level == 6 && s->failed && s->to_write))) {
5599becc
YT		 2891 /* we would like to get this block, possibly by computing it,
2892 * otherwise read it if the backing disk is insync
2893 */
2894 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2895 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2896 if ((s->uptodate == disks - 1) &&
f2b3b44d
N		 2897 (s->failed && (disk_idx == s->failed_num[0] ||
2898 disk_idx == s->failed_num[1]))) {
5599becc
YT		 2899 /* have disk failed, and we're requested to fetch it;
2900 * do compute it
a4456856 2901 */
5599becc
YT		 2902 pr_debug("Computing stripe %llu block %d\n",
2903 (unsigned long long)sh->sector, disk_idx);
2904 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2905 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2906 set_bit(R5_Wantcompute, &dev->flags);
2907 sh->ops.target = disk_idx;
2908 sh->ops.target2 = -1; /* no 2nd target */
2909 s->req_compute = 1;
93b3dbce
N		 2910 /* Careful: from this point on 'uptodate' is in the eye
2911 * of raid_run_ops which services 'compute' operations
2912 * before writes. R5_Wantcompute flags a block that will
2913 * be R5_UPTODATE by the time it is needed for a
2914 * subsequent operation.
2915 */
5599becc
YT		 2916 s->uptodate++;
2917 return 1;
2918 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2919 /* Computing 2-failure is *very* expensive; only
2920 * do it if failed >= 2
2921 */
2922 int other;
2923 for (other = disks; other--; ) {
2924 if (other == disk_idx)
2925 continue;
2926 if (!test_bit(R5_UPTODATE,
2927 &sh->dev[other].flags))
2928 break;
a4456856 2929 }
5599becc
YT		 2930 BUG_ON(other < 0);
2931 pr_debug("Computing stripe %llu blocks %d,%d\n",
2932 (unsigned long long)sh->sector,
2933 disk_idx, other);
2934 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2935 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2936 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2937 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2938 sh->ops.target = disk_idx;
2939 sh->ops.target2 = other;
2940 s->uptodate += 2;
2941 s->req_compute = 1;
2942 return 1;
2943 } else if (test_bit(R5_Insync, &dev->flags)) {
2944 set_bit(R5_LOCKED, &dev->flags);
2945 set_bit(R5_Wantread, &dev->flags);
2946 s->locked++;
2947 pr_debug("Reading block %d (sync=%d)\n",
2948 disk_idx, s->syncing);
a4456856
DW		 2949 }
2950 }
5599becc
YT		 2951
2952 return 0;
2953}
2954
2955/**
93b3dbce 2956 * handle_stripe_fill - read or compute data to satisfy pending requests.
5599becc 2957 */
93b3dbce
N		 2958static void handle_stripe_fill(struct stripe_head *sh,
2959 struct stripe_head_state *s,
2960 int disks)
5599becc
YT		 2961{
2962 int i;
2963
2964 /* look for blocks to read/compute, skip this if a compute
2965 * is already in flight, or if the stripe contents are in the
2966 * midst of changing due to a write
2967 */
2968 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2969 !sh->reconstruct_state)
2970 for (i = disks; i--; )
93b3dbce 2971 if (fetch_block(sh, s, i, disks))
5599becc 2972 break;
a4456856
DW		 2973 set_bit(STRIPE_HANDLE, &sh->state);
2974}
2975
2976
1fe797e6 2977/* handle_stripe_clean_event
a4456856
DW		 2978 * any written block on an uptodate or failed drive can be returned.
2979 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2980 * never LOCKED, so we don't need to test 'failed' directly.
2981 */
d1688a6d 2982static void handle_stripe_clean_event(struct r5conf *conf,
a4456856
DW		 2983 struct stripe_head *sh, int disks, struct bio **return_bi)
2984{
2985 int i;
2986 struct r5dev *dev;
f8dfcffd 2987 int discard_pending = 0;
a4456856
DW		 2988
2989 for (i = disks; i--; )
2990 if (sh->dev[i].written) {
2991 dev = &sh->dev[i];
2992 if (!test_bit(R5_LOCKED, &dev->flags) &&
9e444768 2993 (test_bit(R5_UPTODATE, &dev->flags) ||
ca64cae9 2994 test_bit(R5_Discard, &dev->flags))) {
a4456856
DW		 2995 /* We can return any write requests */
2996 struct bio *wbi, *wbi2;
45b4233c 2997 pr_debug("Return write for disc %d\n", i);
ca64cae9
N		 2998 if (test_and_clear_bit(R5_Discard, &dev->flags))
2999 clear_bit(R5_UPTODATE, &dev->flags);
a4456856
DW		 3000 wbi = dev->written;
3001 dev->written = NULL;
4f024f37 3002 while (wbi && wbi->bi_iter.bi_sector <
a4456856
DW		 3003 dev->sector + STRIPE_SECTORS) {
3004 wbi2 = r5_next_bio(wbi, dev->sector);
e7836bd6 3005 if (!raid5_dec_bi_active_stripes(wbi)) {
a4456856
DW		 3006 md_write_end(conf->mddev);
3007 wbi->bi_next = *return_bi;
3008 *return_bi = wbi;
3009 }
3010 wbi = wbi2;
3011 }
7eaf7e8e
SL		 3012 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3013 STRIPE_SECTORS,
a4456856 3014 !test_bit(STRIPE_DEGRADED, &sh->state),
7eaf7e8e 3015 0);
f8dfcffd
N		 3016 } else if (test_bit(R5_Discard, &dev->flags))
3017 discard_pending = 1;
3018 }
3019 if (!discard_pending &&
3020 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
3021 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
3022 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3023 if (sh->qd_idx >= 0) {
3024 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
3025 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
3026 }
3027 /* now that discard is done we can proceed with any sync */
3028 clear_bit(STRIPE_DISCARD, &sh->state);
d47648fc
SL		 3029 /*
3030 * SCSI discard will change some bio fields and the stripe has
3031 * no updated data, so remove it from hash list and the stripe
3032 * will be reinitialized
3033 */
3034 spin_lock_irq(&conf->device_lock);
3035 remove_hash(sh);
3036 spin_unlock_irq(&conf->device_lock);
f8dfcffd
N		 3037 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
3038 set_bit(STRIPE_HANDLE, &sh->state);
3039
3040 }
8b3e6cdc
DW		 3041
3042 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3043 if (atomic_dec_and_test(&conf->pending_full_writes))
3044 md_wakeup_thread(conf->mddev->thread);
a4456856
DW		 3045}
3046
d1688a6d 3047static void handle_stripe_dirtying(struct r5conf *conf,
c8ac1803
N		 3048 struct stripe_head *sh,
3049 struct stripe_head_state *s,
3050 int disks)
a4456856
DW		 3051{
3052 int rmw = 0, rcw = 0, i;
a7854487
AL		 3053 sector_t recovery_cp = conf->mddev->recovery_cp;
3054
3055 /* RAID6 requires 'rcw' in current implementation.
3056 * Otherwise, check whether resync is now happening or should start.
3057 * If yes, then the array is dirty (after unclean shutdown or
3058 * initial creation), so parity in some stripes might be inconsistent.
3059 * In this case, we need to always do reconstruct-write, to ensure
3060 * that in case of drive failure or read-error correction, we
3061 * generate correct data from the parity.
3062 */
3063 if (conf->max_degraded == 2 ||
3064 (recovery_cp < MaxSector && sh->sector >= recovery_cp)) {
3065 /* Calculate the real rcw later - for now make it
c8ac1803
N		 3066 * look like rcw is cheaper
3067 */
3068 rcw = 1; rmw = 2;
a7854487
AL		 3069 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
3070 conf->max_degraded, (unsigned long long)recovery_cp,
3071 (unsigned long long)sh->sector);
c8ac1803 3072 } else for (i = disks; i--; ) {
a4456856
DW		 3073 /* would I have to read this buffer for read_modify_write */
3074 struct r5dev *dev = &sh->dev[i];
3075 if ((dev->towrite || i == sh->pd_idx) &&
3076 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 3077 !(test_bit(R5_UPTODATE, &dev->flags) ||
3078 test_bit(R5_Wantcompute, &dev->flags))) {
a4456856
DW		 3079 if (test_bit(R5_Insync, &dev->flags))
3080 rmw++;
3081 else
3082 rmw += 2*disks; /* cannot read it */
3083 }
3084 /* Would I have to read this buffer for reconstruct_write */
3085 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
3086 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 3087 !(test_bit(R5_UPTODATE, &dev->flags) ||
3088 test_bit(R5_Wantcompute, &dev->flags))) {
3089 if (test_bit(R5_Insync, &dev->flags)) rcw++;
a4456856
DW		 3090 else
3091 rcw += 2*disks;
3092 }
3093 }
45b4233c 3094 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
a4456856
DW		 3095 (unsigned long long)sh->sector, rmw, rcw);
3096 set_bit(STRIPE_HANDLE, &sh->state);
a9add5d9 3097 if (rmw < rcw && rmw > 0) {
a4456856 3098 /* prefer read-modify-write, but need to get some data */
e3620a3a
JB		 3099 if (conf->mddev->queue)
3100 blk_add_trace_msg(conf->mddev->queue,
3101 "raid5 rmw %llu %d",
3102 (unsigned long long)sh->sector, rmw);
a4456856
DW		 3103 for (i = disks; i--; ) {
3104 struct r5dev *dev = &sh->dev[i];
3105 if ((dev->towrite || i == sh->pd_idx) &&
3106 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219
DW		 3107 !(test_bit(R5_UPTODATE, &dev->flags) ||
3108 test_bit(R5_Wantcompute, &dev->flags)) &&
a4456856
DW		 3109 test_bit(R5_Insync, &dev->flags)) {
3110 if (
3111 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 3112 pr_debug("Read_old block "
a9add5d9 3113 "%d for r-m-w\n", i);
a4456856
DW		 3114 set_bit(R5_LOCKED, &dev->flags);
3115 set_bit(R5_Wantread, &dev->flags);
3116 s->locked++;
3117 } else {
3118 set_bit(STRIPE_DELAYED, &sh->state);
3119 set_bit(STRIPE_HANDLE, &sh->state);
3120 }
3121 }
3122 }
a9add5d9 3123 }
c8ac1803 3124 if (rcw <= rmw && rcw > 0) {
a4456856 3125 /* want reconstruct write, but need to get some data */
a9add5d9 3126 int qread =0;
c8ac1803 3127 rcw = 0;
a4456856
DW		 3128 for (i = disks; i--; ) {
3129 struct r5dev *dev = &sh->dev[i];
3130 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
c8ac1803 3131 i != sh->pd_idx && i != sh->qd_idx &&
a4456856 3132 !test_bit(R5_LOCKED, &dev->flags) &&
f38e1219 3133 !(test_bit(R5_UPTODATE, &dev->flags) ||
c8ac1803
N		 3134 test_bit(R5_Wantcompute, &dev->flags))) {
3135 rcw++;
3136 if (!test_bit(R5_Insync, &dev->flags))
3137 continue; /* it's a failed drive */
a4456856
DW		 3138 if (
3139 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
45b4233c 3140 pr_debug("Read_old block "
a4456856
DW		 3141 "%d for Reconstruct\n", i);
3142 set_bit(R5_LOCKED, &dev->flags);
3143 set_bit(R5_Wantread, &dev->flags);
3144 s->locked++;
a9add5d9 3145 qread++;
a4456856
DW		 3146 } else {
3147 set_bit(STRIPE_DELAYED, &sh->state);
3148 set_bit(STRIPE_HANDLE, &sh->state);
3149 }
3150 }
3151 }
e3620a3a 3152 if (rcw && conf->mddev->queue)
a9add5d9
N		 3153 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
3154 (unsigned long long)sh->sector,
3155 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
c8ac1803 3156 }
a4456856
DW		 3157 /* now if nothing is locked, and if we have enough data,
3158 * we can start a write request
3159 */
f38e1219
DW		 3160 /* since handle_stripe can be called at any time we need to handle the
3161 * case where a compute block operation has been submitted and then a
ac6b53b6
DW		 3162 * subsequent call wants to start a write request. raid_run_ops only
3163 * handles the case where compute block and reconstruct are requested
f38e1219
DW		 3164 * simultaneously. If this is not the case then new writes need to be
3165 * held off until the compute completes.
3166 */
976ea8d4
DW		 3167 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
3168 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
3169 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
c0f7bddb 3170 schedule_reconstruction(sh, s, rcw == 0, 0);
a4456856
DW		 3171}
3172
d1688a6d 3173static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
a4456856
DW		 3174 struct stripe_head_state *s, int disks)
3175{
ecc65c9b 3176 struct r5dev *dev = NULL;
bd2ab670 3177
a4456856 3178 set_bit(STRIPE_HANDLE, &sh->state);
e89f8962 3179
ecc65c9b
DW		 3180 switch (sh->check_state) {
3181 case check_state_idle:
3182 /* start a new check operation if there are no failures */
bd2ab670 3183 if (s->failed == 0) {
bd2ab670 3184 BUG_ON(s->uptodate != disks);
ecc65c9b
DW		 3185 sh->check_state = check_state_run;
3186 set_bit(STRIPE_OP_CHECK, &s->ops_request);
bd2ab670 3187 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
bd2ab670 3188 s->uptodate--;
ecc65c9b 3189 break;
bd2ab670 3190 }
f2b3b44d 3191 dev = &sh->dev[s->failed_num[0]];
ecc65c9b
DW		 3192 /* fall through */
3193 case check_state_compute_result:
3194 sh->check_state = check_state_idle;
3195 if (!dev)
3196 dev = &sh->dev[sh->pd_idx];
3197
3198 /* check that a write has not made the stripe insync */
3199 if (test_bit(STRIPE_INSYNC, &sh->state))
3200 break;
c8894419 3201
a4456856 3202 /* either failed parity check, or recovery is happening */
a4456856
DW		 3203 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3204 BUG_ON(s->uptodate != disks);
3205
3206 set_bit(R5_LOCKED, &dev->flags);
ecc65c9b 3207 s->locked++;
a4456856 3208 set_bit(R5_Wantwrite, &dev->flags);
830ea016 3209
a4456856 3210 clear_bit(STRIPE_DEGRADED, &sh->state);
a4456856 3211 set_bit(STRIPE_INSYNC, &sh->state);
ecc65c9b
DW		 3212 break;
3213 case check_state_run:
3214 break; /* we will be called again upon completion */
3215 case check_state_check_result:
3216 sh->check_state = check_state_idle;
3217
3218 /* if a failure occurred during the check operation, leave
3219 * STRIPE_INSYNC not set and let the stripe be handled again
3220 */
3221 if (s->failed)
3222 break;
3223
3224 /* handle a successful check operation, if parity is correct
3225 * we are done. Otherwise update the mismatch count and repair
3226 * parity if !MD_RECOVERY_CHECK
3227 */
ad283ea4 3228 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
ecc65c9b
DW		 3229 /* parity is correct (on disc,
3230 * not in buffer any more)
3231 */
3232 set_bit(STRIPE_INSYNC, &sh->state);
3233 else {
7f7583d4 3234 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
ecc65c9b
DW		 3235 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3236 /* don't try to repair!! */
3237 set_bit(STRIPE_INSYNC, &sh->state);
3238 else {
3239 sh->check_state = check_state_compute_run;
976ea8d4 3240 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
ecc65c9b
DW		 3241 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3242 set_bit(R5_Wantcompute,
3243 &sh->dev[sh->pd_idx].flags);
3244 sh->ops.target = sh->pd_idx;
ac6b53b6 3245 sh->ops.target2 = -1;
ecc65c9b
DW		 3246 s->uptodate++;
3247 }
3248 }
3249 break;
3250 case check_state_compute_run:
3251 break;
3252 default:
3253 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3254 __func__, sh->check_state,
3255 (unsigned long long) sh->sector);
3256 BUG();
a4456856
DW		 3257 }
3258}
3259
3260
d1688a6d 3261static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
36d1c647 3262 struct stripe_head_state *s,
f2b3b44d 3263 int disks)
a4456856 3264{
a4456856 3265 int pd_idx = sh->pd_idx;
34e04e87 3266 int qd_idx = sh->qd_idx;
d82dfee0 3267 struct r5dev *dev;
a4456856
DW		 3268
3269 set_bit(STRIPE_HANDLE, &sh->state);
3270
3271 BUG_ON(s->failed > 2);
d82dfee0 3272
a4456856
DW		 3273 /* Want to check and possibly repair P and Q.
3274 * However there could be one 'failed' device, in which
3275 * case we can only check one of them, possibly using the
3276 * other to generate missing data
3277 */
3278
d82dfee0
DW		 3279 switch (sh->check_state) {
3280 case check_state_idle:
3281 /* start a new check operation if there are < 2 failures */
f2b3b44d 3282 if (s->failed == s->q_failed) {
d82dfee0 3283 /* The only possible failed device holds Q, so it
a4456856
DW		 3284 * makes sense to check P (If anything else were failed,
3285 * we would have used P to recreate it).
3286 */
d82dfee0 3287 sh->check_state = check_state_run;
a4456856 3288 }
f2b3b44d 3289 if (!s->q_failed && s->failed < 2) {
d82dfee0 3290 /* Q is not failed, and we didn't use it to generate
a4456856
DW		 3291 * anything, so it makes sense to check it
3292 */
d82dfee0
DW		 3293 if (sh->check_state == check_state_run)
3294 sh->check_state = check_state_run_pq;
3295 else
3296 sh->check_state = check_state_run_q;
a4456856 3297 }
a4456856 3298
d82dfee0
DW		 3299 /* discard potentially stale zero_sum_result */
3300 sh->ops.zero_sum_result = 0;
a4456856 3301
d82dfee0
DW		 3302 if (sh->check_state == check_state_run) {
3303 /* async_xor_zero_sum destroys the contents of P */
3304 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3305 s->uptodate--;
a4456856 3306 }
d82dfee0
DW		 3307 if (sh->check_state >= check_state_run &&
3308 sh->check_state <= check_state_run_pq) {
3309 /* async_syndrome_zero_sum preserves P and Q, so
3310 * no need to mark them !uptodate here
3311 */
3312 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3313 break;
a4456856
DW		 3314 }
3315
d82dfee0
DW		 3316 /* we have 2-disk failure */
3317 BUG_ON(s->failed != 2);
3318 /* fall through */
3319 case check_state_compute_result:
3320 sh->check_state = check_state_idle;
a4456856 3321
d82dfee0
DW		 3322 /* check that a write has not made the stripe insync */
3323 if (test_bit(STRIPE_INSYNC, &sh->state))
3324 break;
a4456856
DW		 3325
3326 /* now write out any block on a failed drive,
d82dfee0 3327 * or P or Q if they were recomputed
a4456856 3328 */
d82dfee0 3329 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
a4456856 3330 if (s->failed == 2) {
f2b3b44d 3331 dev = &sh->dev[s->failed_num[1]];
a4456856
DW		 3332 s->locked++;
3333 set_bit(R5_LOCKED, &dev->flags);
3334 set_bit(R5_Wantwrite, &dev->flags);
3335 }
3336 if (s->failed >= 1) {
f2b3b44d 3337 dev = &sh->dev[s->failed_num[0]];
a4456856
DW		 3338 s->locked++;
3339 set_bit(R5_LOCKED, &dev->flags);
3340 set_bit(R5_Wantwrite, &dev->flags);
3341 }
d82dfee0 3342 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
a4456856
DW		 3343 dev = &sh->dev[pd_idx];
3344 s->locked++;
3345 set_bit(R5_LOCKED, &dev->flags);
3346 set_bit(R5_Wantwrite, &dev->flags);
3347 }
d82dfee0 3348 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
a4456856
DW		 3349 dev = &sh->dev[qd_idx];
3350 s->locked++;
3351 set_bit(R5_LOCKED, &dev->flags);
3352 set_bit(R5_Wantwrite, &dev->flags);
3353 }
3354 clear_bit(STRIPE_DEGRADED, &sh->state);
3355
3356 set_bit(STRIPE_INSYNC, &sh->state);
d82dfee0
DW		 3357 break;
3358 case check_state_run:
3359 case check_state_run_q:
3360 case check_state_run_pq:
3361 break; /* we will be called again upon completion */
3362 case check_state_check_result:
3363 sh->check_state = check_state_idle;
3364
3365 /* handle a successful check operation, if parity is correct
3366 * we are done. Otherwise update the mismatch count and repair
3367 * parity if !MD_RECOVERY_CHECK
3368 */
3369 if (sh->ops.zero_sum_result == 0) {
3370 /* both parities are correct */
3371 if (!s->failed)
3372 set_bit(STRIPE_INSYNC, &sh->state);
3373 else {
3374 /* in contrast to the raid5 case we can validate
3375 * parity, but still have a failure to write
3376 * back
3377 */
3378 sh->check_state = check_state_compute_result;
3379 /* Returning at this point means that we may go
3380 * off and bring p and/or q uptodate again so
3381 * we make sure to check zero_sum_result again
3382 * to verify if p or q need writeback
3383 */
3384 }
3385 } else {
7f7583d4 3386 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
d82dfee0
DW		 3387 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3388 /* don't try to repair!! */
3389 set_bit(STRIPE_INSYNC, &sh->state);
3390 else {
3391 int *target = &sh->ops.target;
3392
3393 sh->ops.target = -1;
3394 sh->ops.target2 = -1;
3395 sh->check_state = check_state_compute_run;
3396 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3397 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3398 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3399 set_bit(R5_Wantcompute,
3400 &sh->dev[pd_idx].flags);
3401 *target = pd_idx;
3402 target = &sh->ops.target2;
3403 s->uptodate++;
3404 }
3405 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3406 set_bit(R5_Wantcompute,
3407 &sh->dev[qd_idx].flags);
3408 *target = qd_idx;
3409 s->uptodate++;
3410 }
3411 }
3412 }
3413 break;
3414 case check_state_compute_run:
3415 break;
3416 default:
3417 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3418 __func__, sh->check_state,
3419 (unsigned long long) sh->sector);
3420 BUG();
a4456856
DW		 3421 }
3422}
3423
d1688a6d 3424static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
a4456856
DW		 3425{
3426 int i;
3427
3428 /* We have read all the blocks in this stripe and now we need to
3429 * copy some of them into a target stripe for expand.
3430 */
f0a50d37 3431 struct dma_async_tx_descriptor *tx = NULL;
a4456856
DW		 3432 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3433 for (i = 0; i < sh->disks; i++)
34e04e87 3434 if (i != sh->pd_idx && i != sh->qd_idx) {
911d4ee8 3435 int dd_idx, j;
a4456856 3436 struct stripe_head *sh2;
a08abd8c 3437 struct async_submit_ctl submit;
a4456856 3438
784052ec 3439 sector_t bn = compute_blocknr(sh, i, 1);
911d4ee8
N		 3440 sector_t s = raid5_compute_sector(conf, bn, 0,
3441 &dd_idx, NULL);
a8c906ca 3442 sh2 = get_active_stripe(conf, s, 0, 1, 1);
a4456856
DW		 3443 if (sh2 == NULL)
3444 /* so far only the early blocks of this stripe
3445 * have been requested. When later blocks
3446 * get requested, we will try again
3447 */
3448 continue;
3449 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3450 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3451 /* must have already done this block */
3452 release_stripe(sh2);
3453 continue;
3454 }
f0a50d37
DW		 3455
3456 /* place all the copies on one channel */
a08abd8c 3457 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
f0a50d37 3458 tx = async_memcpy(sh2->dev[dd_idx].page,
88ba2aa5 3459 sh->dev[i].page, 0, 0, STRIPE_SIZE,
a08abd8c 3460 &submit);
f0a50d37 3461
a4456856
DW		 3462 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
3463 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
3464 for (j = 0; j < conf->raid_disks; j++)
3465 if (j != sh2->pd_idx &&
86c374ba 3466 j != sh2->qd_idx &&
a4456856
DW		 3467 !test_bit(R5_Expanded, &sh2->dev[j].flags))
3468 break;
3469 if (j == conf->raid_disks) {
3470 set_bit(STRIPE_EXPAND_READY, &sh2->state);
3471 set_bit(STRIPE_HANDLE, &sh2->state);
3472 }
3473 release_stripe(sh2);
f0a50d37 3474
a4456856 3475 }
a2e08551 3476 /* done submitting copies, wait for them to complete */
749586b7 3477 async_tx_quiesce(&tx);
a4456856 3478}
1da177e4
LT		 3479
3480/*
3481 * handle_stripe - do things to a stripe.
3482 *
9a3e1101
N		 3483 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3484 * state of various bits to see what needs to be done.
1da177e4 3485 * Possible results:
9a3e1101
N		 3486 * return some read requests which now have data
3487 * return some write requests which are safely on storage
1da177e4
LT		 3488 * schedule a read on some buffers
3489 * schedule a write of some buffers
3490 * return confirmation of parity correctness
3491 *
1da177e4 3492 */
a4456856 3493
acfe726b 3494static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
1da177e4 3495{
d1688a6d 3496 struct r5conf *conf = sh->raid_conf;
f416885e 3497 int disks = sh->disks;
474af965
N		 3498 struct r5dev *dev;
3499 int i;
9a3e1101 3500 int do_recovery = 0;
1da177e4 3501
acfe726b
N		 3502 memset(s, 0, sizeof(*s));
3503
acfe726b
N		 3504 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3505 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3506 s->failed_num[0] = -1;
3507 s->failed_num[1] = -1;
1da177e4 3508
acfe726b 3509 /* Now to look around and see what can be done */
1da177e4 3510 rcu_read_lock();
16a53ecc 3511 for (i=disks; i--; ) {
3cb03002 3512 struct md_rdev *rdev;
31c176ec
N		 3513 sector_t first_bad;
3514 int bad_sectors;
3515 int is_bad = 0;
acfe726b 3516
16a53ecc 3517 dev = &sh->dev[i];
1da177e4 3518
45b4233c 3519 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
9a3e1101
N		 3520 i, dev->flags,
3521 dev->toread, dev->towrite, dev->written);
6c0069c0
YT		 3522 /* maybe we can reply to a read
3523 *
3524 * new wantfill requests are only permitted while
3525 * ops_complete_biofill is guaranteed to be inactive
3526 */
3527 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3528 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3529 set_bit(R5_Wantfill, &dev->flags);
1da177e4 3530
16a53ecc 3531 /* now count some things */
cc94015a
N		 3532 if (test_bit(R5_LOCKED, &dev->flags))
3533 s->locked++;
3534 if (test_bit(R5_UPTODATE, &dev->flags))
3535 s->uptodate++;
2d6e4ecc 3536 if (test_bit(R5_Wantcompute, &dev->flags)) {
cc94015a
N		 3537 s->compute++;
3538 BUG_ON(s->compute > 2);
2d6e4ecc 3539 }
1da177e4 3540
acfe726b 3541 if (test_bit(R5_Wantfill, &dev->flags))
cc94015a 3542 s->to_fill++;
acfe726b 3543 else if (dev->toread)
cc94015a 3544 s->to_read++;
16a53ecc 3545 if (dev->towrite) {
cc94015a 3546 s->to_write++;
16a53ecc 3547 if (!test_bit(R5_OVERWRITE, &dev->flags))
cc94015a 3548 s->non_overwrite++;
16a53ecc 3549 }
a4456856 3550 if (dev->written)
cc94015a 3551 s->written++;
14a75d3e
N		 3552 /* Prefer to use the replacement for reads, but only
3553 * if it is recovered enough and has no bad blocks.
3554 */
3555 rdev = rcu_dereference(conf->disks[i].replacement);
3556 if (rdev && !test_bit(Faulty, &rdev->flags) &&
3557 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
3558 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3559 &first_bad, &bad_sectors))
3560 set_bit(R5_ReadRepl, &dev->flags);
3561 else {
9a3e1101
N		 3562 if (rdev)
3563 set_bit(R5_NeedReplace, &dev->flags);
14a75d3e
N		 3564 rdev = rcu_dereference(conf->disks[i].rdev);
3565 clear_bit(R5_ReadRepl, &dev->flags);
3566 }
9283d8c5
N		 3567 if (rdev && test_bit(Faulty, &rdev->flags))
3568 rdev = NULL;
31c176ec
N		 3569 if (rdev) {
3570 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3571 &first_bad, &bad_sectors);
3572 if (s->blocked_rdev == NULL
3573 && (test_bit(Blocked, &rdev->flags)
3574 || is_bad < 0)) {
3575 if (is_bad < 0)
3576 set_bit(BlockedBadBlocks,
3577 &rdev->flags);
3578 s->blocked_rdev = rdev;
3579 atomic_inc(&rdev->nr_pending);
3580 }
6bfe0b49 3581 }
415e72d0
N		 3582 clear_bit(R5_Insync, &dev->flags);
3583 if (!rdev)
3584 /* Not in-sync */;
31c176ec
N		 3585 else if (is_bad) {
3586 /* also not in-sync */
18b9837e
N		 3587 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
3588 test_bit(R5_UPTODATE, &dev->flags)) {
31c176ec
N		 3589 /* treat as in-sync, but with a read error
3590 * which we can now try to correct
3591 */
3592 set_bit(R5_Insync, &dev->flags);
3593 set_bit(R5_ReadError, &dev->flags);
3594 }
3595 } else if (test_bit(In_sync, &rdev->flags))
415e72d0 3596 set_bit(R5_Insync, &dev->flags);
30d7a483 3597 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
415e72d0 3598 /* in sync if before recovery_offset */
30d7a483
N		 3599 set_bit(R5_Insync, &dev->flags);
3600 else if (test_bit(R5_UPTODATE, &dev->flags) &&
3601 test_bit(R5_Expanded, &dev->flags))
3602 /* If we've reshaped into here, we assume it is Insync.
3603 * We will shortly update recovery_offset to make
3604 * it official.
3605 */
3606 set_bit(R5_Insync, &dev->flags);
3607
1cc03eb9 3608 if (test_bit(R5_WriteError, &dev->flags)) {
14a75d3e
N		 3609 /* This flag does not apply to '.replacement'
3610 * only to .rdev, so make sure to check that*/
3611 struct md_rdev *rdev2 = rcu_dereference(
3612 conf->disks[i].rdev);
3613 if (rdev2 == rdev)
3614 clear_bit(R5_Insync, &dev->flags);
3615 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
bc2607f3 3616 s->handle_bad_blocks = 1;
14a75d3e 3617 atomic_inc(&rdev2->nr_pending);
bc2607f3
N		 3618 } else
3619 clear_bit(R5_WriteError, &dev->flags);
3620 }
1cc03eb9 3621 if (test_bit(R5_MadeGood, &dev->flags)) {
14a75d3e
N		 3622 /* This flag does not apply to '.replacement'
3623 * only to .rdev, so make sure to check that*/
3624 struct md_rdev *rdev2 = rcu_dereference(
3625 conf->disks[i].rdev);
3626 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
b84db560 3627 s->handle_bad_blocks = 1;
14a75d3e 3628 atomic_inc(&rdev2->nr_pending);
b84db560
N		 3629 } else
3630 clear_bit(R5_MadeGood, &dev->flags);
3631 }
977df362
N		 3632 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
3633 struct md_rdev *rdev2 = rcu_dereference(
3634 conf->disks[i].replacement);
3635 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3636 s->handle_bad_blocks = 1;
3637 atomic_inc(&rdev2->nr_pending);
3638 } else
3639 clear_bit(R5_MadeGoodRepl, &dev->flags);
3640 }
415e72d0 3641 if (!test_bit(R5_Insync, &dev->flags)) {
16a53ecc
N		 3642 /* The ReadError flag will just be confusing now */
3643 clear_bit(R5_ReadError, &dev->flags);
3644 clear_bit(R5_ReWrite, &dev->flags);
1da177e4 3645 }
415e72d0
N		 3646 if (test_bit(R5_ReadError, &dev->flags))
3647 clear_bit(R5_Insync, &dev->flags);
3648 if (!test_bit(R5_Insync, &dev->flags)) {
cc94015a
N		 3649 if (s->failed < 2)
3650 s->failed_num[s->failed] = i;
3651 s->failed++;
9a3e1101
N		 3652 if (rdev && !test_bit(Faulty, &rdev->flags))
3653 do_recovery = 1;
415e72d0 3654 }
1da177e4 3655 }
9a3e1101
N		 3656 if (test_bit(STRIPE_SYNCING, &sh->state)) {
3657 /* If there is a failed device being replaced,
3658 * we must be recovering.
3659 * else if we are after recovery_cp, we must be syncing
c6d2e084 3660 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
9a3e1101
N		 3661 * else we can only be replacing
3662 * sync and recovery both need to read all devices, and so
3663 * use the same flag.
3664 */
3665 if (do_recovery ||
c6d2e084 3666 sh->sector >= conf->mddev->recovery_cp ||
3667 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
9a3e1101
N		 3668 s->syncing = 1;
3669 else
3670 s->replacing = 1;
3671 }
1da177e4 3672 rcu_read_unlock();
cc94015a
N		 3673}
3674
3675static void handle_stripe(struct stripe_head *sh)
3676{
3677 struct stripe_head_state s;
d1688a6d 3678 struct r5conf *conf = sh->raid_conf;
3687c061 3679 int i;
84789554
N		 3680 int prexor;
3681 int disks = sh->disks;
474af965 3682 struct r5dev *pdev, *qdev;
cc94015a
N		 3683
3684 clear_bit(STRIPE_HANDLE, &sh->state);
257a4b42 3685 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
cc94015a
N		 3686 /* already being handled, ensure it gets handled
3687 * again when current action finishes */
3688 set_bit(STRIPE_HANDLE, &sh->state);
3689 return;
3690 }
3691
f8dfcffd
N		 3692 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3693 spin_lock(&sh->stripe_lock);
3694 /* Cannot process 'sync' concurrently with 'discard' */
3695 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
3696 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3697 set_bit(STRIPE_SYNCING, &sh->state);
3698 clear_bit(STRIPE_INSYNC, &sh->state);
f94c0b66 3699 clear_bit(STRIPE_REPLACED, &sh->state);
f8dfcffd
N		 3700 }
3701 spin_unlock(&sh->stripe_lock);
cc94015a
N		 3702 }
3703 clear_bit(STRIPE_DELAYED, &sh->state);
3704
3705 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3706 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3707 (unsigned long long)sh->sector, sh->state,
3708 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
3709 sh->check_state, sh->reconstruct_state);
3687c061 3710
acfe726b 3711 analyse_stripe(sh, &s);
c5a31000 3712
bc2607f3
N		 3713 if (s.handle_bad_blocks) {
3714 set_bit(STRIPE_HANDLE, &sh->state);
3715 goto finish;
3716 }
3717
474af965
N		 3718 if (unlikely(s.blocked_rdev)) {
3719 if (s.syncing || s.expanding || s.expanded ||
9a3e1101 3720 s.replacing || s.to_write || s.written) {
474af965
N		 3721 set_bit(STRIPE_HANDLE, &sh->state);
3722 goto finish;
3723 }
3724 /* There is nothing for the blocked_rdev to block */
3725 rdev_dec_pending(s.blocked_rdev, conf->mddev);
3726 s.blocked_rdev = NULL;
3727 }
3728
3729 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3730 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3731 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3732 }
3733
3734 pr_debug("locked=%d uptodate=%d to_read=%d"
3735 " to_write=%d failed=%d failed_num=%d,%d\n",
3736 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3737 s.failed_num[0], s.failed_num[1]);
3738 /* check if the array has lost more than max_degraded devices and,
3739 * if so, some requests might need to be failed.
3740 */
9a3f530f
N		 3741 if (s.failed > conf->max_degraded) {
3742 sh->check_state = 0;
3743 sh->reconstruct_state = 0;
3744 if (s.to_read+s.to_write+s.written)
3745 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
9a3e1101 3746 if (s.syncing + s.replacing)
9a3f530f
N		 3747 handle_failed_sync(conf, sh, &s);
3748 }
474af965 3749
84789554
N		 3750 /* Now we check to see if any write operations have recently
3751 * completed
3752 */
3753 prexor = 0;
3754 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3755 prexor = 1;
3756 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3757 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3758 sh->reconstruct_state = reconstruct_state_idle;
3759
3760 /* All the 'written' buffers and the parity block are ready to
3761 * be written back to disk
3762 */
9e444768
SL		 3763 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
3764 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
84789554 3765 BUG_ON(sh->qd_idx >= 0 &&
9e444768
SL		 3766 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
3767 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
84789554
N		 3768 for (i = disks; i--; ) {
3769 struct r5dev *dev = &sh->dev[i];
3770 if (test_bit(R5_LOCKED, &dev->flags) &&
3771 (i == sh->pd_idx || i == sh->qd_idx ||
3772 dev->written)) {
3773 pr_debug("Writing block %d\n", i);
3774 set_bit(R5_Wantwrite, &dev->flags);
3775 if (prexor)
3776 continue;
3777 if (!test_bit(R5_Insync, &dev->flags) ||
3778 ((i == sh->pd_idx || i == sh->qd_idx) &&
3779 s.failed == 0))
3780 set_bit(STRIPE_INSYNC, &sh->state);
3781 }
3782 }
3783 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3784 s.dec_preread_active = 1;
3785 }
3786
ef5b7c69
N		 3787 /*
3788 * might be able to return some write requests if the parity blocks
3789 * are safe, or on a failed drive
3790 */
3791 pdev = &sh->dev[sh->pd_idx];
3792 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
3793 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
3794 qdev = &sh->dev[sh->qd_idx];
3795 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
3796 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
3797 || conf->level < 6;
3798
3799 if (s.written &&
3800 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3801 && !test_bit(R5_LOCKED, &pdev->flags)
3802 && (test_bit(R5_UPTODATE, &pdev->flags) ||
3803 test_bit(R5_Discard, &pdev->flags))))) &&
3804 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3805 && !test_bit(R5_LOCKED, &qdev->flags)
3806 && (test_bit(R5_UPTODATE, &qdev->flags) ||
3807 test_bit(R5_Discard, &qdev->flags))))))
3808 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
3809
3810 /* Now we might consider reading some blocks, either to check/generate
3811 * parity, or to satisfy requests
3812 * or to load a block that is being partially written.
3813 */
3814 if (s.to_read || s.non_overwrite
3815 || (conf->level == 6 && s.to_write && s.failed)
3816 || (s.syncing && (s.uptodate + s.compute < disks))
3817 || s.replacing
3818 || s.expanding)
3819 handle_stripe_fill(sh, &s, disks);
3820
84789554
N		 3821 /* Now to consider new write requests and what else, if anything
3822 * should be read. We do not handle new writes when:
3823 * 1/ A 'write' operation (copy+xor) is already in flight.
3824 * 2/ A 'check' operation is in flight, as it may clobber the parity
3825 * block.
3826 */
3827 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3828 handle_stripe_dirtying(conf, sh, &s, disks);
3829
3830 /* maybe we need to check and possibly fix the parity for this stripe
3831 * Any reads will already have been scheduled, so we just see if enough
3832 * data is available. The parity check is held off while parity
3833 * dependent operations are in flight.
3834 */
3835 if (sh->check_state ||
3836 (s.syncing && s.locked == 0 &&
3837 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3838 !test_bit(STRIPE_INSYNC, &sh->state))) {
3839 if (conf->level == 6)
3840 handle_parity_checks6(conf, sh, &s, disks);
3841 else
3842 handle_parity_checks5(conf, sh, &s, disks);
3843 }
c5a31000 3844
f94c0b66
N		 3845 if ((s.replacing || s.syncing) && s.locked == 0
3846 && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
3847 && !test_bit(STRIPE_REPLACED, &sh->state)) {
9a3e1101
N		 3848 /* Write out to replacement devices where possible */
3849 for (i = 0; i < conf->raid_disks; i++)
f94c0b66
N		 3850 if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
3851 WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
9a3e1101
N		 3852 set_bit(R5_WantReplace, &sh->dev[i].flags);
3853 set_bit(R5_LOCKED, &sh->dev[i].flags);
3854 s.locked++;
3855 }
f94c0b66
N		 3856 if (s.replacing)
3857 set_bit(STRIPE_INSYNC, &sh->state);
3858 set_bit(STRIPE_REPLACED, &sh->state);
9a3e1101
N		 3859 }
3860 if ((s.syncing || s.replacing) && s.locked == 0 &&
f94c0b66 3861 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
9a3e1101 3862 test_bit(STRIPE_INSYNC, &sh->state)) {
c5a31000
N		 3863 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3864 clear_bit(STRIPE_SYNCING, &sh->state);
f8dfcffd
N		 3865 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3866 wake_up(&conf->wait_for_overlap);
c5a31000
N		 3867 }
3868
3869 /* If the failed drives are just a ReadError, then we might need
3870 * to progress the repair/check process
3871 */
3872 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
3873 for (i = 0; i < s.failed; i++) {
3874 struct r5dev *dev = &sh->dev[s.failed_num[i]];
3875 if (test_bit(R5_ReadError, &dev->flags)
3876 && !test_bit(R5_LOCKED, &dev->flags)
3877 && test_bit(R5_UPTODATE, &dev->flags)
3878 ) {
3879 if (!test_bit(R5_ReWrite, &dev->flags)) {
3880 set_bit(R5_Wantwrite, &dev->flags);
3881 set_bit(R5_ReWrite, &dev->flags);
3882 set_bit(R5_LOCKED, &dev->flags);
3883 s.locked++;
3884 } else {
3885 /* let's read it back */
3886 set_bit(R5_Wantread, &dev->flags);
3887 set_bit(R5_LOCKED, &dev->flags);
3888 s.locked++;
3889 }
3890 }
3891 }
3892
3893
3687c061
N		 3894 /* Finish reconstruct operations initiated by the expansion process */
3895 if (sh->reconstruct_state == reconstruct_state_result) {
3896 struct stripe_head *sh_src
3897 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3898 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
3899 /* sh cannot be written until sh_src has been read.
3900 * so arrange for sh to be delayed a little
3901 */
3902 set_bit(STRIPE_DELAYED, &sh->state);
3903 set_bit(STRIPE_HANDLE, &sh->state);
3904 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3905 &sh_src->state))
3906 atomic_inc(&conf->preread_active_stripes);
3907 release_stripe(sh_src);
3908 goto finish;
3909 }
3910 if (sh_src)
3911 release_stripe(sh_src);
3912
3913 sh->reconstruct_state = reconstruct_state_idle;
3914 clear_bit(STRIPE_EXPANDING, &sh->state);
3915 for (i = conf->raid_disks; i--; ) {
3916 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3917 set_bit(R5_LOCKED, &sh->dev[i].flags);
3918 s.locked++;
3919 }
3920 }
f416885e 3921
3687c061
N		 3922 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3923 !sh->reconstruct_state) {
3924 /* Need to write out all blocks after computing parity */
3925 sh->disks = conf->raid_disks;
3926 stripe_set_idx(sh->sector, conf, 0, sh);
3927 schedule_reconstruction(sh, &s, 1, 1);
3928 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3929 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3930 atomic_dec(&conf->reshape_stripes);
3931 wake_up(&conf->wait_for_overlap);
3932 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3933 }
3934
3935 if (s.expanding && s.locked == 0 &&
3936 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3937 handle_stripe_expansion(conf, sh);
16a53ecc 3938
3687c061 3939finish:
6bfe0b49 3940 /* wait for this device to become unblocked */
5f066c63
N		 3941 if (unlikely(s.blocked_rdev)) {
3942 if (conf->mddev->external)
3943 md_wait_for_blocked_rdev(s.blocked_rdev,
3944 conf->mddev);
3945 else
3946 /* Internal metadata will immediately
3947 * be written by raid5d, so we don't
3948 * need to wait here.
3949 */
3950 rdev_dec_pending(s.blocked_rdev,
3951 conf->mddev);
3952 }
6bfe0b49 3953
bc2607f3
N		 3954 if (s.handle_bad_blocks)
3955 for (i = disks; i--; ) {
3cb03002 3956 struct md_rdev *rdev;
bc2607f3
N		 3957 struct r5dev *dev = &sh->dev[i];
3958 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
3959 /* We own a safe reference to the rdev */
3960 rdev = conf->disks[i].rdev;
3961 if (!rdev_set_badblocks(rdev, sh->sector,
3962 STRIPE_SECTORS, 0))
3963 md_error(conf->mddev, rdev);
3964 rdev_dec_pending(rdev, conf->mddev);
3965 }
b84db560
N		 3966 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
3967 rdev = conf->disks[i].rdev;
3968 rdev_clear_badblocks(rdev, sh->sector,
c6563a8c 3969 STRIPE_SECTORS, 0);
b84db560
N		 3970 rdev_dec_pending(rdev, conf->mddev);
3971 }
977df362
N		 3972 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
3973 rdev = conf->disks[i].replacement;
dd054fce
N		 3974 if (!rdev)
3975 /* rdev have been moved down */
3976 rdev = conf->disks[i].rdev;
977df362 3977 rdev_clear_badblocks(rdev, sh->sector,
c6563a8c 3978 STRIPE_SECTORS, 0);
977df362
N		 3979 rdev_dec_pending(rdev, conf->mddev);
3980 }
bc2607f3
N		 3981 }
3982
6c0069c0
YT		 3983 if (s.ops_request)
3984 raid_run_ops(sh, s.ops_request);
3985
f0e43bcd 3986 ops_run_io(sh, &s);
16a53ecc 3987
c5709ef6 3988 if (s.dec_preread_active) {
729a1866 3989 /* We delay this until after ops_run_io so that if make_request
e9c7469b 3990 * is waiting on a flush, it won't continue until the writes
729a1866
N		 3991 * have actually been submitted.
3992 */
3993 atomic_dec(&conf->preread_active_stripes);
3994 if (atomic_read(&conf->preread_active_stripes) <
3995 IO_THRESHOLD)
3996 md_wakeup_thread(conf->mddev->thread);
3997 }
3998
c5709ef6 3999 return_io(s.return_bi);
16a53ecc 4000
257a4b42 4001 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
16a53ecc
N		 4002}
4003
d1688a6d 4004static void raid5_activate_delayed(struct r5conf *conf)
16a53ecc
N		 4005{
4006 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
4007 while (!list_empty(&conf->delayed_list)) {
4008 struct list_head *l = conf->delayed_list.next;
4009 struct stripe_head *sh;
4010 sh = list_entry(l, struct stripe_head, lru);
4011 list_del_init(l);
4012 clear_bit(STRIPE_DELAYED, &sh->state);
4013 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4014 atomic_inc(&conf->preread_active_stripes);
8b3e6cdc 4015 list_add_tail(&sh->lru, &conf->hold_list);
851c30c9 4016 raid5_wakeup_stripe_thread(sh);
16a53ecc 4017 }
482c0834 4018 }
16a53ecc
N		 4019}
4020
566c09c5
SL		 4021static void activate_bit_delay(struct r5conf *conf,
4022 struct list_head *temp_inactive_list)
16a53ecc
N		 4023{
4024 /* device_lock is held */
4025 struct list_head head;
4026 list_add(&head, &conf->bitmap_list);
4027 list_del_init(&conf->bitmap_list);
4028 while (!list_empty(&head)) {
4029 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
566c09c5 4030 int hash;
16a53ecc
N		 4031 list_del_init(&sh->lru);
4032 atomic_inc(&sh->count);
566c09c5
SL		 4033 hash = sh->hash_lock_index;
4034 __release_stripe(conf, sh, &temp_inactive_list[hash]);
16a53ecc
N		 4035 }
4036}
4037
fd01b88c 4038int md_raid5_congested(struct mddev *mddev, int bits)
f022b2fd 4039{
d1688a6d 4040 struct r5conf *conf = mddev->private;
f022b2fd
N		 4041
4042 /* No difference between reads and writes. Just check
4043 * how busy the stripe_cache is
4044 */
3fa841d7 4045
f022b2fd
N		 4046 if (conf->inactive_blocked)
4047 return 1;
4048 if (conf->quiesce)
4049 return 1;
4bda556a 4050 if (atomic_read(&conf->empty_inactive_list_nr))
f022b2fd
N		 4051 return 1;
4052
4053 return 0;
4054}
11d8a6e3
N		 4055EXPORT_SYMBOL_GPL(md_raid5_congested);
4056
4057static int raid5_congested(void *data, int bits)
4058{
fd01b88c 4059 struct mddev *mddev = data;
11d8a6e3
N		 4060
4061 return mddev_congested(mddev, bits) ||
4062 md_raid5_congested(mddev, bits);
4063}
f022b2fd 4064
23032a0e
RBJ		 4065/* We want read requests to align with chunks where possible,
4066 * but write requests don't need to.
4067 */
cc371e66
AK		 4068static int raid5_mergeable_bvec(struct request_queue *q,
4069 struct bvec_merge_data *bvm,
4070 struct bio_vec *biovec)
23032a0e 4071{
fd01b88c 4072 struct mddev *mddev = q->queuedata;
cc371e66 4073 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
23032a0e 4074 int max;
9d8f0363 4075 unsigned int chunk_sectors = mddev->chunk_sectors;
cc371e66 4076 unsigned int bio_sectors = bvm->bi_size >> 9;
23032a0e 4077
cc371e66 4078 if ((bvm->bi_rw & 1) == WRITE)
23032a0e
RBJ		 4079 return biovec->bv_len; /* always allow writes to be mergeable */
4080
664e7c41
AN		 4081 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
4082 chunk_sectors = mddev->new_chunk_sectors;
23032a0e
RBJ		 4083 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
4084 if (max < 0) max = 0;
4085 if (max <= biovec->bv_len && bio_sectors == 0)
4086 return biovec->bv_len;
4087 else
4088 return max;
4089}
4090
f679623f 4091
fd01b88c 4092static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
f679623f 4093{
4f024f37 4094 sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev);
9d8f0363 4095 unsigned int chunk_sectors = mddev->chunk_sectors;
aa8b57aa 4096 unsigned int bio_sectors = bio_sectors(bio);
f679623f 4097
664e7c41
AN		 4098 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
4099 chunk_sectors = mddev->new_chunk_sectors;
f679623f
RBJ		 4100 return chunk_sectors >=
4101 ((sector & (chunk_sectors - 1)) + bio_sectors);
4102}
4103
46031f9a
RBJ		 4104/*
4105 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
4106 * later sampled by raid5d.
4107 */
d1688a6d 4108static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
46031f9a
RBJ		 4109{
4110 unsigned long flags;
4111
4112 spin_lock_irqsave(&conf->device_lock, flags);
4113
4114 bi->bi_next = conf->retry_read_aligned_list;
4115 conf->retry_read_aligned_list = bi;
4116
4117 spin_unlock_irqrestore(&conf->device_lock, flags);
4118 md_wakeup_thread(conf->mddev->thread);
4119}
4120
4121
d1688a6d 4122static struct bio *remove_bio_from_retry(struct r5conf *conf)
46031f9a
RBJ		 4123{
4124 struct bio *bi;
4125
4126 bi = conf->retry_read_aligned;
4127 if (bi) {
4128 conf->retry_read_aligned = NULL;
4129 return bi;
4130 }
4131 bi = conf->retry_read_aligned_list;
4132 if(bi) {
387bb173 4133 conf->retry_read_aligned_list = bi->bi_next;
46031f9a 4134 bi->bi_next = NULL;
960e739d
JA		 4135 /*
4136 * this sets the active strip count to 1 and the processed
4137 * strip count to zero (upper 8 bits)
4138 */
e7836bd6 4139 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
46031f9a
RBJ		 4140 }
4141
4142 return bi;
4143}
4144
4145
f679623f
RBJ		 4146/*
4147 * The "raid5_align_endio" should check if the read succeeded and if it
4148 * did, call bio_endio on the original bio (having bio_put the new bio
4149 * first).
4150 * If the read failed..
4151 */
6712ecf8 4152static void raid5_align_endio(struct bio *bi, int error)
f679623f
RBJ		 4153{
4154 struct bio* raid_bi = bi->bi_private;
fd01b88c 4155 struct mddev *mddev;
d1688a6d 4156 struct r5conf *conf;
46031f9a 4157 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3cb03002 4158 struct md_rdev *rdev;
46031f9a 4159
f679623f 4160 bio_put(bi);
46031f9a 4161
46031f9a
RBJ		 4162 rdev = (void*)raid_bi->bi_next;
4163 raid_bi->bi_next = NULL;
2b7f2228
N		 4164 mddev = rdev->mddev;
4165 conf = mddev->private;
46031f9a
RBJ		 4166
4167 rdev_dec_pending(rdev, conf->mddev);
4168
4169 if (!error && uptodate) {
0a82a8d1
LT		 4170 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
4171 raid_bi, 0);
6712ecf8 4172 bio_endio(raid_bi, 0);
46031f9a
RBJ		 4173 if (atomic_dec_and_test(&conf->active_aligned_reads))
4174 wake_up(&conf->wait_for_stripe);
6712ecf8 4175 return;
46031f9a
RBJ		 4176 }
4177
4178
45b4233c 4179 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
46031f9a
RBJ		 4180
4181 add_bio_to_retry(raid_bi, conf);
f679623f
RBJ		 4182}
4183
387bb173
NB		 4184static int bio_fits_rdev(struct bio *bi)
4185{
165125e1 4186 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
387bb173 4187
aa8b57aa 4188 if (bio_sectors(bi) > queue_max_sectors(q))
387bb173
NB		 4189 return 0;
4190 blk_recount_segments(q, bi);
8a78362c 4191 if (bi->bi_phys_segments > queue_max_segments(q))
387bb173
NB		 4192 return 0;
4193
4194 if (q->merge_bvec_fn)
4195 /* it's too hard to apply the merge_bvec_fn at this stage,
4196 * just just give up
4197 */
4198 return 0;
4199
4200 return 1;
4201}
4202
4203
fd01b88c 4204static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio)
f679623f 4205{
d1688a6d 4206 struct r5conf *conf = mddev->private;
8553fe7e 4207 int dd_idx;
f679623f 4208 struct bio* align_bi;
3cb03002 4209 struct md_rdev *rdev;
671488cc 4210 sector_t end_sector;
f679623f
RBJ		 4211
4212 if (!in_chunk_boundary(mddev, raid_bio)) {
45b4233c 4213 pr_debug("chunk_aligned_read : non aligned\n");
f679623f
RBJ		 4214 return 0;
4215 }
4216 /*
a167f663 4217 * use bio_clone_mddev to make a copy of the bio
f679623f 4218 */
a167f663 4219 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
f679623f
RBJ		 4220 if (!align_bi)
4221 return 0;
4222 /*
4223 * set bi_end_io to a new function, and set bi_private to the
4224 * original bio.
4225 */
4226 align_bi->bi_end_io = raid5_align_endio;
4227 align_bi->bi_private = raid_bio;
4228 /*
4229 * compute position
4230 */
4f024f37
KO		 4231 align_bi->bi_iter.bi_sector =
4232 raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector,
4233 0, &dd_idx, NULL);
f679623f 4234
f73a1c7d 4235 end_sector = bio_end_sector(align_bi);
f679623f 4236 rcu_read_lock();
671488cc
N		 4237 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
4238 if (!rdev || test_bit(Faulty, &rdev->flags) ||
4239 rdev->recovery_offset < end_sector) {
4240 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
4241 if (rdev &&
4242 (test_bit(Faulty, &rdev->flags) ||
4243 !(test_bit(In_sync, &rdev->flags) ||
4244 rdev->recovery_offset >= end_sector)))
4245 rdev = NULL;
4246 }
4247 if (rdev) {
31c176ec
N		 4248 sector_t first_bad;
4249 int bad_sectors;
4250
f679623f
RBJ		 4251 atomic_inc(&rdev->nr_pending);
4252 rcu_read_unlock();
46031f9a
RBJ		 4253 raid_bio->bi_next = (void*)rdev;
4254 align_bi->bi_bdev = rdev->bdev;
4255 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
46031f9a 4256
31c176ec 4257 if (!bio_fits_rdev(align_bi) ||
4f024f37
KO		 4258 is_badblock(rdev, align_bi->bi_iter.bi_sector,
4259 bio_sectors(align_bi),
31c176ec
N		 4260 &first_bad, &bad_sectors)) {
4261 /* too big in some way, or has a known bad block */
387bb173
NB		 4262 bio_put(align_bi);
4263 rdev_dec_pending(rdev, mddev);
4264 return 0;
4265 }
4266
6c0544e2 4267 /* No reshape active, so we can trust rdev->data_offset */
4f024f37 4268 align_bi->bi_iter.bi_sector += rdev->data_offset;
6c0544e2 4269
46031f9a
RBJ		 4270 spin_lock_irq(&conf->device_lock);
4271 wait_event_lock_irq(conf->wait_for_stripe,
4272 conf->quiesce == 0,
eed8c02e 4273 conf->device_lock);
46031f9a
RBJ		 4274 atomic_inc(&conf->active_aligned_reads);
4275 spin_unlock_irq(&conf->device_lock);
4276
e3620a3a
JB		 4277 if (mddev->gendisk)
4278 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4279 align_bi, disk_devt(mddev->gendisk),
4f024f37 4280 raid_bio->bi_iter.bi_sector);
f679623f
RBJ		 4281 generic_make_request(align_bi);
4282 return 1;
4283 } else {
4284 rcu_read_unlock();
46031f9a 4285 bio_put(align_bi);
f679623f
RBJ		 4286 return 0;
4287 }
4288}
4289
8b3e6cdc
DW		 4290/* __get_priority_stripe - get the next stripe to process
4291 *
4292 * Full stripe writes are allowed to pass preread active stripes up until
4293 * the bypass_threshold is exceeded. In general the bypass_count
4294 * increments when the handle_list is handled before the hold_list; however, it
4295 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4296 * stripe with in flight i/o. The bypass_count will be reset when the
4297 * head of the hold_list has changed, i.e. the head was promoted to the
4298 * handle_list.
4299 */
851c30c9 4300static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
8b3e6cdc 4301{
851c30c9
SL		 4302 struct stripe_head *sh = NULL, *tmp;
4303 struct list_head *handle_list = NULL;
bfc90cb0 4304 struct r5worker_group *wg = NULL;
851c30c9
SL		 4305
4306 if (conf->worker_cnt_per_group == 0) {
4307 handle_list = &conf->handle_list;
4308 } else if (group != ANY_GROUP) {
4309 handle_list = &conf->worker_groups[group].handle_list;
bfc90cb0 4310 wg = &conf->worker_groups[group];
851c30c9
SL		 4311 } else {
4312 int i;
4313 for (i = 0; i < conf->group_cnt; i++) {
4314 handle_list = &conf->worker_groups[i].handle_list;
bfc90cb0 4315 wg = &conf->worker_groups[i];
851c30c9
SL		 4316 if (!list_empty(handle_list))
4317 break;
4318 }
4319 }
8b3e6cdc
DW		 4320
4321 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4322 __func__,
851c30c9 4323 list_empty(handle_list) ? "empty" : "busy",
8b3e6cdc
DW		 4324 list_empty(&conf->hold_list) ? "empty" : "busy",
4325 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4326
851c30c9
SL		 4327 if (!list_empty(handle_list)) {
4328 sh = list_entry(handle_list->next, typeof(*sh), lru);
8b3e6cdc
DW		 4329
4330 if (list_empty(&conf->hold_list))
4331 conf->bypass_count = 0;
4332 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4333 if (conf->hold_list.next == conf->last_hold)
4334 conf->bypass_count++;
4335 else {
4336 conf->last_hold = conf->hold_list.next;
4337 conf->bypass_count -= conf->bypass_threshold;
4338 if (conf->bypass_count < 0)
4339 conf->bypass_count = 0;
4340 }
4341 }
4342 } else if (!list_empty(&conf->hold_list) &&
4343 ((conf->bypass_threshold &&
4344 conf->bypass_count > conf->bypass_threshold) ||
4345 atomic_read(&conf->pending_full_writes) == 0)) {
851c30c9
SL		 4346
4347 list_for_each_entry(tmp, &conf->hold_list, lru) {
4348 if (conf->worker_cnt_per_group == 0 ||
4349 group == ANY_GROUP ||
4350 !cpu_online(tmp->cpu) ||
4351 cpu_to_group(tmp->cpu) == group) {
4352 sh = tmp;
4353 break;
4354 }
4355 }
4356
4357 if (sh) {
4358 conf->bypass_count -= conf->bypass_threshold;
4359 if (conf->bypass_count < 0)
4360 conf->bypass_count = 0;
4361 }
bfc90cb0 4362 wg = NULL;
851c30c9
SL		 4363 }
4364
4365 if (!sh)
8b3e6cdc
DW		 4366 return NULL;
4367
bfc90cb0
SL		 4368 if (wg) {
4369 wg->stripes_cnt--;
4370 sh->group = NULL;
4371 }
8b3e6cdc
DW		 4372 list_del_init(&sh->lru);
4373 atomic_inc(&sh->count);
4374 BUG_ON(atomic_read(&sh->count) != 1);
4375 return sh;
4376}
f679623f 4377
8811b596
SL		 4378struct raid5_plug_cb {
4379 struct blk_plug_cb cb;
4380 struct list_head list;
566c09c5 4381 struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS];
8811b596
SL		 4382};
4383
4384static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
4385{
4386 struct raid5_plug_cb *cb = container_of(
4387 blk_cb, struct raid5_plug_cb, cb);
4388 struct stripe_head *sh;
4389 struct mddev *mddev = cb->cb.data;
4390 struct r5conf *conf = mddev->private;
a9add5d9 4391 int cnt = 0;
566c09c5 4392 int hash;
8811b596
SL		 4393
4394 if (cb->list.next && !list_empty(&cb->list)) {
4395 spin_lock_irq(&conf->device_lock);
4396 while (!list_empty(&cb->list)) {
4397 sh = list_first_entry(&cb->list, struct stripe_head, lru);
4398 list_del_init(&sh->lru);
4399 /*
4400 * avoid race release_stripe_plug() sees
4401 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4402 * is still in our list
4403 */
4404 smp_mb__before_clear_bit();
4405 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
773ca82f
SL		 4406 /*
4407 * STRIPE_ON_RELEASE_LIST could be set here. In that
4408 * case, the count is always > 1 here
4409 */
566c09c5
SL		 4410 hash = sh->hash_lock_index;
4411 __release_stripe(conf, sh, &cb->temp_inactive_list[hash]);
a9add5d9 4412 cnt++;
8811b596
SL		 4413 }
4414 spin_unlock_irq(&conf->device_lock);
4415 }
566c09c5
SL		 4416 release_inactive_stripe_list(conf, cb->temp_inactive_list,
4417 NR_STRIPE_HASH_LOCKS);
e3620a3a
JB		 4418 if (mddev->queue)
4419 trace_block_unplug(mddev->queue, cnt, !from_schedule);
8811b596
SL		 4420 kfree(cb);
4421}
4422
4423static void release_stripe_plug(struct mddev *mddev,
4424 struct stripe_head *sh)
4425{
4426 struct blk_plug_cb *blk_cb = blk_check_plugged(
4427 raid5_unplug, mddev,
4428 sizeof(struct raid5_plug_cb));
4429 struct raid5_plug_cb *cb;
4430
4431 if (!blk_cb) {
4432 release_stripe(sh);
4433 return;
4434 }
4435
4436 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
4437
566c09c5
SL		 4438 if (cb->list.next == NULL) {
4439 int i;
8811b596 4440 INIT_LIST_HEAD(&cb->list);
566c09c5
SL		 4441 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
4442 INIT_LIST_HEAD(cb->temp_inactive_list + i);
4443 }
8811b596
SL		 4444
4445 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
4446 list_add_tail(&sh->lru, &cb->list);
4447 else
4448 release_stripe(sh);
4449}
4450
620125f2
SL		 4451static void make_discard_request(struct mddev *mddev, struct bio *bi)
4452{
4453 struct r5conf *conf = mddev->private;
4454 sector_t logical_sector, last_sector;
4455 struct stripe_head *sh;
4456 int remaining;
4457 int stripe_sectors;
4458
4459 if (mddev->reshape_position != MaxSector)
4460 /* Skip discard while reshape is happening */
4461 return;
4462
4f024f37
KO		 4463 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4464 last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
620125f2
SL		 4465
4466 bi->bi_next = NULL;
4467 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4468
4469 stripe_sectors = conf->chunk_sectors *
4470 (conf->raid_disks - conf->max_degraded);
4471 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
4472 stripe_sectors);
4473 sector_div(last_sector, stripe_sectors);
4474
4475 logical_sector *= conf->chunk_sectors;
4476 last_sector *= conf->chunk_sectors;
4477
4478 for (; logical_sector < last_sector;
4479 logical_sector += STRIPE_SECTORS) {
4480 DEFINE_WAIT(w);
4481 int d;
4482 again:
4483 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
4484 prepare_to_wait(&conf->wait_for_overlap, &w,
4485 TASK_UNINTERRUPTIBLE);
f8dfcffd
N		 4486 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
4487 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4488 release_stripe(sh);
4489 schedule();
4490 goto again;
4491 }
4492 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
620125f2
SL		 4493 spin_lock_irq(&sh->stripe_lock);
4494 for (d = 0; d < conf->raid_disks; d++) {
4495 if (d == sh->pd_idx || d == sh->qd_idx)
4496 continue;
4497 if (sh->dev[d].towrite || sh->dev[d].toread) {
4498 set_bit(R5_Overlap, &sh->dev[d].flags);
4499 spin_unlock_irq(&sh->stripe_lock);
4500 release_stripe(sh);
4501 schedule();
4502 goto again;
4503 }
4504 }
f8dfcffd 4505 set_bit(STRIPE_DISCARD, &sh->state);
620125f2
SL		 4506 finish_wait(&conf->wait_for_overlap, &w);
4507 for (d = 0; d < conf->raid_disks; d++) {
4508 if (d == sh->pd_idx || d == sh->qd_idx)
4509 continue;
4510 sh->dev[d].towrite = bi;
4511 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
4512 raid5_inc_bi_active_stripes(bi);
4513 }
4514 spin_unlock_irq(&sh->stripe_lock);
4515 if (conf->mddev->bitmap) {
4516 for (d = 0;
4517 d < conf->raid_disks - conf->max_degraded;
4518 d++)
4519 bitmap_startwrite(mddev->bitmap,
4520 sh->sector,
4521 STRIPE_SECTORS,
4522 0);
4523 sh->bm_seq = conf->seq_flush + 1;
4524 set_bit(STRIPE_BIT_DELAY, &sh->state);
4525 }
4526
4527 set_bit(STRIPE_HANDLE, &sh->state);
4528 clear_bit(STRIPE_DELAYED, &sh->state);
4529 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4530 atomic_inc(&conf->preread_active_stripes);
4531 release_stripe_plug(mddev, sh);
4532 }
4533
4534 remaining = raid5_dec_bi_active_stripes(bi);
4535 if (remaining == 0) {
4536 md_write_end(mddev);
4537 bio_endio(bi, 0);
4538 }
4539}
4540
b4fdcb02 4541static void make_request(struct mddev *mddev, struct bio * bi)
1da177e4 4542{
d1688a6d 4543 struct r5conf *conf = mddev->private;
911d4ee8 4544 int dd_idx;
1da177e4
LT		 4545 sector_t new_sector;
4546 sector_t logical_sector, last_sector;
4547 struct stripe_head *sh;
a362357b 4548 const int rw = bio_data_dir(bi);
49077326 4549 int remaining;
27c0f68f
SL		 4550 DEFINE_WAIT(w);
4551 bool do_prepare;
1da177e4 4552
e9c7469b
TH		 4553 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
4554 md_flush_request(mddev, bi);
5a7bbad2 4555 return;
e5dcdd80
N		 4556 }
4557
3d310eb7 4558 md_write_start(mddev, bi);
06d91a5f 4559
802ba064 4560 if (rw == READ &&
52488615 4561 mddev->reshape_position == MaxSector &&
21a52c6d 4562 chunk_aligned_read(mddev,bi))
5a7bbad2 4563 return;
52488615 4564
620125f2
SL		 4565 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
4566 make_discard_request(mddev, bi);
4567 return;
4568 }
4569
4f024f37 4570 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
f73a1c7d 4571 last_sector = bio_end_sector(bi);
1da177e4
LT		 4572 bi->bi_next = NULL;
4573 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
06d91a5f 4574
27c0f68f 4575 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
1da177e4 4576 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
b5663ba4 4577 int previous;
c46501b2 4578 int seq;
b578d55f 4579
27c0f68f 4580 do_prepare = false;
7ecaa1e6 4581 retry:
c46501b2 4582 seq = read_seqcount_begin(&conf->gen_lock);
b5663ba4 4583 previous = 0;
27c0f68f
SL		 4584 if (do_prepare)
4585 prepare_to_wait(&conf->wait_for_overlap, &w,
4586 TASK_UNINTERRUPTIBLE);
b0f9ec04 4587 if (unlikely(conf->reshape_progress != MaxSector)) {
fef9c61f 4588 /* spinlock is needed as reshape_progress may be
df8e7f76
N		 4589 * 64bit on a 32bit platform, and so it might be
4590 * possible to see a half-updated value
aeb878b0 4591 * Of course reshape_progress could change after
df8e7f76
N		 4592 * the lock is dropped, so once we get a reference
4593 * to the stripe that we think it is, we will have
4594 * to check again.
4595 */
7ecaa1e6 4596 spin_lock_irq(&conf->device_lock);
2c810cdd 4597 if (mddev->reshape_backwards
fef9c61f
N		 4598 ? logical_sector < conf->reshape_progress
4599 : logical_sector >= conf->reshape_progress) {
b5663ba4
N		 4600 previous = 1;
4601 } else {
2c810cdd 4602 if (mddev->reshape_backwards
fef9c61f
N		 4603 ? logical_sector < conf->reshape_safe
4604 : logical_sector >= conf->reshape_safe) {
b578d55f
N		 4605 spin_unlock_irq(&conf->device_lock);
4606 schedule();
27c0f68f 4607 do_prepare = true;
b578d55f
N		 4608 goto retry;
4609 }
4610 }
7ecaa1e6
N		 4611 spin_unlock_irq(&conf->device_lock);
4612 }
16a53ecc 4613
112bf897
N		 4614 new_sector = raid5_compute_sector(conf, logical_sector,
4615 previous,
911d4ee8 4616 &dd_idx, NULL);
0c55e022 4617 pr_debug("raid456: make_request, sector %llu logical %llu\n",
c46501b2 4618 (unsigned long long)new_sector,
1da177e4
LT		 4619 (unsigned long long)logical_sector);
4620
b5663ba4 4621 sh = get_active_stripe(conf, new_sector, previous,
a8c906ca 4622 (bi->bi_rw&RWA_MASK), 0);
1da177e4 4623 if (sh) {
b0f9ec04 4624 if (unlikely(previous)) {
7ecaa1e6 4625 /* expansion might have moved on while waiting for a
df8e7f76
N		 4626 * stripe, so we must do the range check again.
4627 * Expansion could still move past after this
4628 * test, but as we are holding a reference to
4629 * 'sh', we know that if that happens,
4630 * STRIPE_EXPANDING will get set and the expansion
4631 * won't proceed until we finish with the stripe.
7ecaa1e6
N		 4632 */
4633 int must_retry = 0;
4634 spin_lock_irq(&conf->device_lock);
2c810cdd 4635 if (mddev->reshape_backwards
b0f9ec04
N		 4636 ? logical_sector >= conf->reshape_progress
4637 : logical_sector < conf->reshape_progress)
7ecaa1e6
N		 4638 /* mismatch, need to try again */
4639 must_retry = 1;
4640 spin_unlock_irq(&conf->device_lock);
4641 if (must_retry) {
4642 release_stripe(sh);
7a3ab908 4643 schedule();
27c0f68f 4644 do_prepare = true;
7ecaa1e6
N		 4645 goto retry;
4646 }
4647 }
c46501b2
N		 4648 if (read_seqcount_retry(&conf->gen_lock, seq)) {
4649 /* Might have got the wrong stripe_head
4650 * by accident
4651 */
4652 release_stripe(sh);
4653 goto retry;
4654 }
e62e58a5 4655
ffd96e35 4656 if (rw == WRITE &&
a5c308d4 4657 logical_sector >= mddev->suspend_lo &&
e464eafd
N		 4658 logical_sector < mddev->suspend_hi) {
4659 release_stripe(sh);
e62e58a5
N		 4660 /* As the suspend_* range is controlled by
4661 * userspace, we want an interruptible
4662 * wait.
4663 */
4664 flush_signals(current);
4665 prepare_to_wait(&conf->wait_for_overlap,
4666 &w, TASK_INTERRUPTIBLE);
4667 if (logical_sector >= mddev->suspend_lo &&
27c0f68f 4668 logical_sector < mddev->suspend_hi) {
e62e58a5 4669 schedule();
27c0f68f
SL		 4670 do_prepare = true;
4671 }
e464eafd
N		 4672 goto retry;
4673 }
7ecaa1e6
N		 4674
4675 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
ffd96e35 4676 !add_stripe_bio(sh, bi, dd_idx, rw)) {
7ecaa1e6
N		 4677 /* Stripe is busy expanding or
4678 * add failed due to overlap. Flush everything
1da177e4
LT		 4679 * and wait a while
4680 */
482c0834 4681 md_wakeup_thread(mddev->thread);
1da177e4
LT		 4682 release_stripe(sh);
4683 schedule();
27c0f68f 4684 do_prepare = true;
1da177e4
LT		 4685 goto retry;
4686 }
6ed3003c
N		 4687 set_bit(STRIPE_HANDLE, &sh->state);
4688 clear_bit(STRIPE_DELAYED, &sh->state);
a852d7b8 4689 if ((bi->bi_rw & REQ_SYNC) &&
729a1866
N		 4690 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4691 atomic_inc(&conf->preread_active_stripes);
8811b596 4692 release_stripe_plug(mddev, sh);
1da177e4
LT		 4693 } else {
4694 /* cannot get stripe for read-ahead, just give-up */
4695 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1da177e4
LT		 4696 break;
4697 }
1da177e4 4698 }
27c0f68f 4699 finish_wait(&conf->wait_for_overlap, &w);
7c13edc8 4700
e7836bd6 4701 remaining = raid5_dec_bi_active_stripes(bi);
f6344757 4702 if (remaining == 0) {
1da177e4 4703
16a53ecc 4704 if ( rw == WRITE )
1da177e4 4705 md_write_end(mddev);
6712ecf8 4706
0a82a8d1
LT		 4707 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
4708 bi, 0);
0e13fe23 4709 bio_endio(bi, 0);
1da177e4 4710 }
1da177e4
LT		 4711}
4712
fd01b88c 4713static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
b522adcd 4714
fd01b88c 4715static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
1da177e4 4716{
52c03291
N		 4717 /* reshaping is quite different to recovery/resync so it is
4718 * handled quite separately ... here.
4719 *
4720 * On each call to sync_request, we gather one chunk worth of
4721 * destination stripes and flag them as expanding.
4722 * Then we find all the source stripes and request reads.
4723 * As the reads complete, handle_stripe will copy the data
4724 * into the destination stripe and release that stripe.
4725 */
d1688a6d 4726 struct r5conf *conf = mddev->private;
1da177e4 4727 struct stripe_head *sh;
ccfcc3c1 4728 sector_t first_sector, last_sector;
f416885e
N		 4729 int raid_disks = conf->previous_raid_disks;
4730 int data_disks = raid_disks - conf->max_degraded;
4731 int new_data_disks = conf->raid_disks - conf->max_degraded;
52c03291
N		 4732 int i;
4733 int dd_idx;
c8f517c4 4734 sector_t writepos, readpos, safepos;
ec32a2bd 4735 sector_t stripe_addr;
7a661381 4736 int reshape_sectors;
ab69ae12 4737 struct list_head stripes;
52c03291 4738
fef9c61f
N		 4739 if (sector_nr == 0) {
4740 /* If restarting in the middle, skip the initial sectors */
2c810cdd 4741 if (mddev->reshape_backwards &&
fef9c61f
N		 4742 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4743 sector_nr = raid5_size(mddev, 0, 0)
4744 - conf->reshape_progress;
2c810cdd 4745 } else if (!mddev->reshape_backwards &&
fef9c61f
N		 4746 conf->reshape_progress > 0)
4747 sector_nr = conf->reshape_progress;
f416885e 4748 sector_div(sector_nr, new_data_disks);
fef9c61f 4749 if (sector_nr) {
8dee7211
N		 4750 mddev->curr_resync_completed = sector_nr;
4751 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
fef9c61f
N		 4752 *skipped = 1;
4753 return sector_nr;
4754 }
52c03291
N		 4755 }
4756
7a661381
N		 4757 /* We need to process a full chunk at a time.
4758 * If old and new chunk sizes differ, we need to process the
4759 * largest of these
4760 */
664e7c41
AN		 4761 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4762 reshape_sectors = mddev->new_chunk_sectors;
7a661381 4763 else
9d8f0363 4764 reshape_sectors = mddev->chunk_sectors;
7a661381 4765
b5254dd5
N		 4766 /* We update the metadata at least every 10 seconds, or when
4767 * the data about to be copied would over-write the source of
4768 * the data at the front of the range. i.e. one new_stripe
4769 * along from reshape_progress new_maps to after where
4770 * reshape_safe old_maps to
52c03291 4771 */
fef9c61f 4772 writepos = conf->reshape_progress;
f416885e 4773 sector_div(writepos, new_data_disks);
c8f517c4
N		 4774 readpos = conf->reshape_progress;
4775 sector_div(readpos, data_disks);
fef9c61f 4776 safepos = conf->reshape_safe;
f416885e 4777 sector_div(safepos, data_disks);
2c810cdd 4778 if (mddev->reshape_backwards) {
ed37d83e 4779 writepos -= min_t(sector_t, reshape_sectors, writepos);
c8f517c4 4780 readpos += reshape_sectors;
7a661381 4781 safepos += reshape_sectors;
fef9c61f 4782 } else {
7a661381 4783 writepos += reshape_sectors;
ed37d83e
N		 4784 readpos -= min_t(sector_t, reshape_sectors, readpos);
4785 safepos -= min_t(sector_t, reshape_sectors, safepos);
fef9c61f 4786 }
52c03291 4787
b5254dd5
N		 4788 /* Having calculated the 'writepos' possibly use it
4789 * to set 'stripe_addr' which is where we will write to.
4790 */
4791 if (mddev->reshape_backwards) {
4792 BUG_ON(conf->reshape_progress == 0);
4793 stripe_addr = writepos;
4794 BUG_ON((mddev->dev_sectors &
4795 ~((sector_t)reshape_sectors - 1))
4796 - reshape_sectors - stripe_addr
4797 != sector_nr);
4798 } else {
4799 BUG_ON(writepos != sector_nr + reshape_sectors);
4800 stripe_addr = sector_nr;
4801 }
4802
c8f517c4
N		 4803 /* 'writepos' is the most advanced device address we might write.
4804 * 'readpos' is the least advanced device address we might read.
4805 * 'safepos' is the least address recorded in the metadata as having
4806 * been reshaped.
b5254dd5
N		 4807 * If there is a min_offset_diff, these are adjusted either by
4808 * increasing the safepos/readpos if diff is negative, or
4809 * increasing writepos if diff is positive.
4810 * If 'readpos' is then behind 'writepos', there is no way that we can
c8f517c4
N		 4811 * ensure safety in the face of a crash - that must be done by userspace
4812 * making a backup of the data. So in that case there is no particular
4813 * rush to update metadata.
4814 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4815 * update the metadata to advance 'safepos' to match 'readpos' so that
4816 * we can be safe in the event of a crash.
4817 * So we insist on updating metadata if safepos is behind writepos and
4818 * readpos is beyond writepos.
4819 * In any case, update the metadata every 10 seconds.
4820 * Maybe that number should be configurable, but I'm not sure it is
4821 * worth it.... maybe it could be a multiple of safemode_delay???
4822 */
b5254dd5
N		 4823 if (conf->min_offset_diff < 0) {
4824 safepos += -conf->min_offset_diff;
4825 readpos += -conf->min_offset_diff;
4826 } else
4827 writepos += conf->min_offset_diff;
4828
2c810cdd 4829 if ((mddev->reshape_backwards
c8f517c4
N		 4830 ? (safepos > writepos && readpos < writepos)
4831 : (safepos < writepos && readpos > writepos)) ||
4832 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
52c03291
N		 4833 /* Cannot proceed until we've updated the superblock... */
4834 wait_event(conf->wait_for_overlap,
c91abf5a
N		 4835 atomic_read(&conf->reshape_stripes)==0
4836 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
4837 if (atomic_read(&conf->reshape_stripes) != 0)
4838 return 0;
fef9c61f 4839 mddev->reshape_position = conf->reshape_progress;
75d3da43 4840 mddev->curr_resync_completed = sector_nr;
c8f517c4 4841 conf->reshape_checkpoint = jiffies;
850b2b42 4842 set_bit(MD_CHANGE_DEVS, &mddev->flags);
52c03291 4843 md_wakeup_thread(mddev->thread);
850b2b42 4844 wait_event(mddev->sb_wait, mddev->flags == 0 ||
c91abf5a
N		 4845 test_bit(MD_RECOVERY_INTR, &mddev->recovery));
4846 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
4847 return 0;
52c03291 4848 spin_lock_irq(&conf->device_lock);
fef9c61f 4849 conf->reshape_safe = mddev->reshape_position;
52c03291
N		 4850 spin_unlock_irq(&conf->device_lock);
4851 wake_up(&conf->wait_for_overlap);
acb180b0 4852 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
52c03291
N		 4853 }
4854
ab69ae12 4855 INIT_LIST_HEAD(&stripes);
7a661381 4856 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
52c03291 4857 int j;
a9f326eb 4858 int skipped_disk = 0;
a8c906ca 4859 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
52c03291
N		 4860 set_bit(STRIPE_EXPANDING, &sh->state);
4861 atomic_inc(&conf->reshape_stripes);
4862 /* If any of this stripe is beyond the end of the old
4863 * array, then we need to zero those blocks
4864 */
4865 for (j=sh->disks; j--;) {
4866 sector_t s;
4867 if (j == sh->pd_idx)
4868 continue;
f416885e 4869 if (conf->level == 6 &&
d0dabf7e 4870 j == sh->qd_idx)
f416885e 4871 continue;
784052ec 4872 s = compute_blocknr(sh, j, 0);
b522adcd 4873 if (s < raid5_size(mddev, 0, 0)) {
a9f326eb 4874 skipped_disk = 1;
52c03291
N		 4875 continue;
4876 }
4877 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4878 set_bit(R5_Expanded, &sh->dev[j].flags);
4879 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4880 }
a9f326eb 4881 if (!skipped_disk) {
52c03291
N		 4882 set_bit(STRIPE_EXPAND_READY, &sh->state);
4883 set_bit(STRIPE_HANDLE, &sh->state);
4884 }
ab69ae12 4885 list_add(&sh->lru, &stripes);
52c03291
N		 4886 }
4887 spin_lock_irq(&conf->device_lock);
2c810cdd 4888 if (mddev->reshape_backwards)
7a661381 4889 conf->reshape_progress -= reshape_sectors * new_data_disks;
fef9c61f 4890 else
7a661381 4891 conf->reshape_progress += reshape_sectors * new_data_disks;
52c03291
N		 4892 spin_unlock_irq(&conf->device_lock);
4893 /* Ok, those stripe are ready. We can start scheduling
4894 * reads on the source stripes.
4895 * The source stripes are determined by mapping the first and last
4896 * block on the destination stripes.
4897 */
52c03291 4898 first_sector =
ec32a2bd 4899 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
911d4ee8 4900 1, &dd_idx, NULL);
52c03291 4901 last_sector =
0e6e0271 4902 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
09c9e5fa 4903 * new_data_disks - 1),
911d4ee8 4904 1, &dd_idx, NULL);
58c0fed4
AN		 4905 if (last_sector >= mddev->dev_sectors)
4906 last_sector = mddev->dev_sectors - 1;
52c03291 4907 while (first_sector <= last_sector) {
a8c906ca 4908 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
52c03291
N		 4909 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4910 set_bit(STRIPE_HANDLE, &sh->state);
4911 release_stripe(sh);
4912 first_sector += STRIPE_SECTORS;
4913 }
ab69ae12
N		 4914 /* Now that the sources are clearly marked, we can release
4915 * the destination stripes
4916 */
4917 while (!list_empty(&stripes)) {
4918 sh = list_entry(stripes.next, struct stripe_head, lru);
4919 list_del_init(&sh->lru);
4920 release_stripe(sh);
4921 }
c6207277
N		 4922 /* If this takes us to the resync_max point where we have to pause,
4923 * then we need to write out the superblock.
4924 */
7a661381 4925 sector_nr += reshape_sectors;
c03f6a19
N		 4926 if ((sector_nr - mddev->curr_resync_completed) * 2
4927 >= mddev->resync_max - mddev->curr_resync_completed) {
c6207277
N		 4928 /* Cannot proceed until we've updated the superblock... */
4929 wait_event(conf->wait_for_overlap,
c91abf5a
N		 4930 atomic_read(&conf->reshape_stripes) == 0
4931 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
4932 if (atomic_read(&conf->reshape_stripes) != 0)
4933 goto ret;
fef9c61f 4934 mddev->reshape_position = conf->reshape_progress;
75d3da43 4935 mddev->curr_resync_completed = sector_nr;
c8f517c4 4936 conf->reshape_checkpoint = jiffies;
c6207277
N		 4937 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4938 md_wakeup_thread(mddev->thread);
4939 wait_event(mddev->sb_wait,
4940 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
c91abf5a
N		 4941 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
4942 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
4943 goto ret;
c6207277 4944 spin_lock_irq(&conf->device_lock);
fef9c61f 4945 conf->reshape_safe = mddev->reshape_position;
c6207277
N		 4946 spin_unlock_irq(&conf->device_lock);
4947 wake_up(&conf->wait_for_overlap);
acb180b0 4948 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
c6207277 4949 }
c91abf5a 4950ret:
7a661381 4951 return reshape_sectors;
52c03291
N		 4952}
4953
4954/* FIXME go_faster isn't used */
fd01b88c 4955static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
52c03291 4956{
d1688a6d 4957 struct r5conf *conf = mddev->private;
52c03291 4958 struct stripe_head *sh;
58c0fed4 4959 sector_t max_sector = mddev->dev_sectors;
57dab0bd 4960 sector_t sync_blocks;
16a53ecc
N		 4961 int still_degraded = 0;
4962 int i;
1da177e4 4963
72626685 4964 if (sector_nr >= max_sector) {
1da177e4 4965 /* just being told to finish up .. nothing much to do */
cea9c228 4966
29269553
N		 4967 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4968 end_reshape(conf);
4969 return 0;
4970 }
72626685
N		 4971
4972 if (mddev->curr_resync < max_sector) /* aborted */
4973 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4974 &sync_blocks, 1);
16a53ecc 4975 else /* completed sync */
72626685
N		 4976 conf->fullsync = 0;
4977 bitmap_close_sync(mddev->bitmap);
4978
1da177e4
LT		 4979 return 0;
4980 }
ccfcc3c1 4981
64bd660b
N		 4982 /* Allow raid5_quiesce to complete */
4983 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4984
52c03291
N		 4985 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4986 return reshape_request(mddev, sector_nr, skipped);
f6705578 4987
c6207277
N		 4988 /* No need to check resync_max as we never do more than one
4989 * stripe, and as resync_max will always be on a chunk boundary,
4990 * if the check in md_do_sync didn't fire, there is no chance
4991 * of overstepping resync_max here
4992 */
4993
16a53ecc 4994 /* if there is too many failed drives and we are trying
1da177e4
LT		 4995 * to resync, then assert that we are finished, because there is
4996 * nothing we can do.
4997 */
3285edf1 4998 if (mddev->degraded >= conf->max_degraded &&
16a53ecc 4999 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
58c0fed4 5000 sector_t rv = mddev->dev_sectors - sector_nr;
57afd89f 5001 *skipped = 1;
1da177e4
LT		 5002 return rv;
5003 }
6f608040 5004 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
5005 !conf->fullsync &&
5006 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
5007 sync_blocks >= STRIPE_SECTORS) {
72626685
N		 5008 /* we can skip this block, and probably more */
5009 sync_blocks /= STRIPE_SECTORS;
5010 *skipped = 1;
5011 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
5012 }
1da177e4 5013
b47490c9
N		 5014 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
5015
a8c906ca 5016 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
1da177e4 5017 if (sh == NULL) {
a8c906ca 5018 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
1da177e4 5019 /* make sure we don't swamp the stripe cache if someone else
16a53ecc 5020 * is trying to get access
1da177e4 5021 */
66c006a5 5022 schedule_timeout_uninterruptible(1);
1da177e4 5023 }
16a53ecc
N		 5024 /* Need to check if array will still be degraded after recovery/resync
5025 * We don't need to check the 'failed' flag as when that gets set,
5026 * recovery aborts.
5027 */
f001a70c 5028 for (i = 0; i < conf->raid_disks; i++)
16a53ecc
N		 5029 if (conf->disks[i].rdev == NULL)
5030 still_degraded = 1;
5031
5032 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
5033
83206d66 5034 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
1da177e4 5035
1442577b 5036 handle_stripe(sh);
1da177e4
LT		 5037 release_stripe(sh);
5038
5039 return STRIPE_SECTORS;
5040}
5041
d1688a6d 5042static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
46031f9a
RBJ		 5043{
5044 /* We may not be able to submit a whole bio at once as there
5045 * may not be enough stripe_heads available.
5046 * We cannot pre-allocate enough stripe_heads as we may need
5047 * more than exist in the cache (if we allow ever large chunks).
5048 * So we do one stripe head at a time and record in
5049 * ->bi_hw_segments how many have been done.
5050 *
5051 * We *know* that this entire raid_bio is in one chunk, so
5052 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
5053 */
5054 struct stripe_head *sh;
911d4ee8 5055 int dd_idx;
46031f9a
RBJ		 5056 sector_t sector, logical_sector, last_sector;
5057 int scnt = 0;
5058 int remaining;
5059 int handled = 0;
5060
4f024f37
KO		 5061 logical_sector = raid_bio->bi_iter.bi_sector &
5062 ~((sector_t)STRIPE_SECTORS-1);
112bf897 5063 sector = raid5_compute_sector(conf, logical_sector,
911d4ee8 5064 0, &dd_idx, NULL);
f73a1c7d 5065 last_sector = bio_end_sector(raid_bio);
46031f9a
RBJ		 5066
5067 for (; logical_sector < last_sector;
387bb173
NB		 5068 logical_sector += STRIPE_SECTORS,
5069 sector += STRIPE_SECTORS,
5070 scnt++) {
46031f9a 5071
e7836bd6 5072 if (scnt < raid5_bi_processed_stripes(raid_bio))
46031f9a
RBJ		 5073 /* already done this stripe */
5074 continue;
5075
a8c906ca 5076 sh = get_active_stripe(conf, sector, 0, 1, 0);
46031f9a
RBJ		 5077
5078 if (!sh) {
5079 /* failed to get a stripe - must wait */
e7836bd6 5080 raid5_set_bi_processed_stripes(raid_bio, scnt);
46031f9a
RBJ		 5081 conf->retry_read_aligned = raid_bio;
5082 return handled;
5083 }
5084
387bb173
NB		 5085 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
5086 release_stripe(sh);
e7836bd6 5087 raid5_set_bi_processed_stripes(raid_bio, scnt);
387bb173
NB		 5088 conf->retry_read_aligned = raid_bio;
5089 return handled;
5090 }
5091
3f9e7c14 5092 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
36d1c647 5093 handle_stripe(sh);
46031f9a
RBJ		 5094 release_stripe(sh);
5095 handled++;
5096 }
e7836bd6 5097 remaining = raid5_dec_bi_active_stripes(raid_bio);
0a82a8d1
LT		 5098 if (remaining == 0) {
5099 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
5100 raid_bio, 0);
0e13fe23 5101 bio_endio(raid_bio, 0);
0a82a8d1 5102 }
46031f9a
RBJ		 5103 if (atomic_dec_and_test(&conf->active_aligned_reads))
5104 wake_up(&conf->wait_for_stripe);
5105 return handled;
5106}
5107
bfc90cb0 5108static int handle_active_stripes(struct r5conf *conf, int group,
566c09c5
SL		 5109 struct r5worker *worker,
5110 struct list_head *temp_inactive_list)
46a06401
SL		 5111{
5112 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
566c09c5
SL		 5113 int i, batch_size = 0, hash;
5114 bool release_inactive = false;
46a06401
SL		 5115
5116 while (batch_size < MAX_STRIPE_BATCH &&
851c30c9 5117 (sh = __get_priority_stripe(conf, group)) != NULL)
46a06401
SL		 5118 batch[batch_size++] = sh;
5119
566c09c5
SL		 5120 if (batch_size == 0) {
5121 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5122 if (!list_empty(temp_inactive_list + i))
5123 break;
5124 if (i == NR_STRIPE_HASH_LOCKS)
5125 return batch_size;
5126 release_inactive = true;
5127 }
46a06401
SL		 5128 spin_unlock_irq(&conf->device_lock);
5129
566c09c5
SL		 5130 release_inactive_stripe_list(conf, temp_inactive_list,
5131 NR_STRIPE_HASH_LOCKS);
5132
5133 if (release_inactive) {
5134 spin_lock_irq(&conf->device_lock);
5135 return 0;
5136 }
5137
46a06401
SL		 5138 for (i = 0; i < batch_size; i++)
5139 handle_stripe(batch[i]);
5140
5141 cond_resched();
5142
5143 spin_lock_irq(&conf->device_lock);
566c09c5
SL		 5144 for (i = 0; i < batch_size; i++) {
5145 hash = batch[i]->hash_lock_index;
5146 __release_stripe(conf, batch[i], &temp_inactive_list[hash]);
5147 }
46a06401
SL		 5148 return batch_size;
5149}
46031f9a 5150
851c30c9
SL		 5151static void raid5_do_work(struct work_struct *work)
5152{
5153 struct r5worker *worker = container_of(work, struct r5worker, work);
5154 struct r5worker_group *group = worker->group;
5155 struct r5conf *conf = group->conf;
5156 int group_id = group - conf->worker_groups;
5157 int handled;
5158 struct blk_plug plug;
5159
5160 pr_debug("+++ raid5worker active\n");
5161
5162 blk_start_plug(&plug);
5163 handled = 0;
5164 spin_lock_irq(&conf->device_lock);
5165 while (1) {
5166 int batch_size, released;
5167
566c09c5 5168 released = release_stripe_list(conf, worker->temp_inactive_list);
851c30c9 5169
566c09c5
SL		 5170 batch_size = handle_active_stripes(conf, group_id, worker,
5171 worker->temp_inactive_list);
bfc90cb0 5172 worker->working = false;
851c30c9
SL		 5173 if (!batch_size && !released)
5174 break;
5175 handled += batch_size;
5176 }
5177 pr_debug("%d stripes handled\n", handled);
5178
5179 spin_unlock_irq(&conf->device_lock);
5180 blk_finish_plug(&plug);
5181
5182 pr_debug("--- raid5worker inactive\n");
5183}
5184
1da177e4
LT		 5185/*
5186 * This is our raid5 kernel thread.
5187 *
5188 * We scan the hash table for stripes which can be handled now.
5189 * During the scan, completed stripes are saved for us by the interrupt
5190 * handler, so that they will not have to wait for our next wakeup.
5191 */
4ed8731d 5192static void raid5d(struct md_thread *thread)
1da177e4 5193{
4ed8731d 5194 struct mddev *mddev = thread->mddev;
d1688a6d 5195 struct r5conf *conf = mddev->private;
1da177e4 5196 int handled;
e1dfa0a2 5197 struct blk_plug plug;
1da177e4 5198
45b4233c 5199 pr_debug("+++ raid5d active\n");
1da177e4
LT		 5200
5201 md_check_recovery(mddev);
1da177e4 5202
e1dfa0a2 5203 blk_start_plug(&plug);
1da177e4
LT		 5204 handled = 0;
5205 spin_lock_irq(&conf->device_lock);
5206 while (1) {
46031f9a 5207 struct bio *bio;
773ca82f
SL		 5208 int batch_size, released;
5209
566c09c5 5210 released = release_stripe_list(conf, conf->temp_inactive_list);
1da177e4 5211
0021b7bc 5212 if (
7c13edc8
N		 5213 !list_empty(&conf->bitmap_list)) {
5214 /* Now is a good time to flush some bitmap updates */
5215 conf->seq_flush++;
700e432d 5216 spin_unlock_irq(&conf->device_lock);
72626685 5217 bitmap_unplug(mddev->bitmap);
700e432d 5218 spin_lock_irq(&conf->device_lock);
7c13edc8 5219 conf->seq_write = conf->seq_flush;
566c09c5 5220 activate_bit_delay(conf, conf->temp_inactive_list);
72626685 5221 }
0021b7bc 5222 raid5_activate_delayed(conf);
72626685 5223
46031f9a
RBJ		 5224 while ((bio = remove_bio_from_retry(conf))) {
5225 int ok;
5226 spin_unlock_irq(&conf->device_lock);
5227 ok = retry_aligned_read(conf, bio);
5228 spin_lock_irq(&conf->device_lock);
5229 if (!ok)
5230 break;
5231 handled++;
5232 }
5233
566c09c5
SL		 5234 batch_size = handle_active_stripes(conf, ANY_GROUP, NULL,
5235 conf->temp_inactive_list);
773ca82f 5236 if (!batch_size && !released)
1da177e4 5237 break;
46a06401 5238 handled += batch_size;
1da177e4 5239
46a06401
SL		 5240 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
5241 spin_unlock_irq(&conf->device_lock);
de393cde 5242 md_check_recovery(mddev);
46a06401
SL		 5243 spin_lock_irq(&conf->device_lock);
5244 }
1da177e4 5245 }
45b4233c 5246 pr_debug("%d stripes handled\n", handled);
1da177e4
LT		 5247
5248 spin_unlock_irq(&conf->device_lock);
5249
c9f21aaf 5250 async_tx_issue_pending_all();
e1dfa0a2 5251 blk_finish_plug(&plug);
1da177e4 5252
45b4233c 5253 pr_debug("--- raid5d inactive\n");
1da177e4
LT		 5254}
5255
3f294f4f 5256static ssize_t
fd01b88c 5257raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
3f294f4f 5258{
d1688a6d 5259 struct r5conf *conf = mddev->private;
96de1e66
N		 5260 if (conf)
5261 return sprintf(page, "%d\n", conf->max_nr_stripes);
5262 else
5263 return 0;
3f294f4f
N		 5264}
5265
c41d4ac4 5266int
fd01b88c 5267raid5_set_cache_size(struct mddev *mddev, int size)
3f294f4f 5268{
d1688a6d 5269 struct r5conf *conf = mddev->private;
b5470dc5 5270 int err;
566c09c5 5271 int hash;
b5470dc5 5272
c41d4ac4 5273 if (size <= 16 || size > 32768)
3f294f4f 5274 return -EINVAL;
566c09c5 5275 hash = (conf->max_nr_stripes - 1) % NR_STRIPE_HASH_LOCKS;
c41d4ac4 5276 while (size < conf->max_nr_stripes) {
566c09c5 5277 if (drop_one_stripe(conf, hash))
3f294f4f
N		 5278 conf->max_nr_stripes--;
5279 else
5280 break;
566c09c5
SL		 5281 hash--;
5282 if (hash < 0)
5283 hash = NR_STRIPE_HASH_LOCKS - 1;
3f294f4f 5284 }
b5470dc5
DW		 5285 err = md_allow_write(mddev);
5286 if (err)
5287 return err;
566c09c5 5288 hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
c41d4ac4 5289 while (size > conf->max_nr_stripes) {
566c09c5 5290 if (grow_one_stripe(conf, hash))
3f294f4f
N		 5291 conf->max_nr_stripes++;
5292 else break;
566c09c5 5293 hash = (hash + 1) % NR_STRIPE_HASH_LOCKS;
3f294f4f 5294 }
c41d4ac4
N		 5295 return 0;
5296}
5297EXPORT_SYMBOL(raid5_set_cache_size);
5298
5299static ssize_t
fd01b88c 5300raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
c41d4ac4 5301{
d1688a6d 5302 struct r5conf *conf = mddev->private;
c41d4ac4
N		 5303 unsigned long new;
5304 int err;
5305
5306 if (len >= PAGE_SIZE)
5307 return -EINVAL;
5308 if (!conf)
5309 return -ENODEV;
5310
b29bebd6 5311 if (kstrtoul(page, 10, &new))
c41d4ac4
N		 5312 return -EINVAL;
5313 err = raid5_set_cache_size(mddev, new);
5314 if (err)
5315 return err;
3f294f4f
N		 5316 return len;
5317}
007583c9 5318
96de1e66
N		 5319static struct md_sysfs_entry
5320raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
5321 raid5_show_stripe_cache_size,
5322 raid5_store_stripe_cache_size);
3f294f4f 5323
8b3e6cdc 5324static ssize_t
fd01b88c 5325raid5_show_preread_threshold(struct mddev *mddev, char *page)
8b3e6cdc 5326{
d1688a6d 5327 struct r5conf *conf = mddev->private;
8b3e6cdc
DW		 5328 if (conf)
5329 return sprintf(page, "%d\n", conf->bypass_threshold);
5330 else
5331 return 0;
5332}
5333
5334static ssize_t
fd01b88c 5335raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
8b3e6cdc 5336{
d1688a6d 5337 struct r5conf *conf = mddev->private;
4ef197d8 5338 unsigned long new;
8b3e6cdc
DW		 5339 if (len >= PAGE_SIZE)
5340 return -EINVAL;
5341 if (!conf)
5342 return -ENODEV;
5343
b29bebd6 5344 if (kstrtoul(page, 10, &new))
8b3e6cdc 5345 return -EINVAL;
4ef197d8 5346 if (new > conf->max_nr_stripes)
8b3e6cdc
DW		 5347 return -EINVAL;
5348 conf->bypass_threshold = new;
5349 return len;
5350}
5351
5352static struct md_sysfs_entry
5353raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
5354 S_IRUGO | S_IWUSR,
5355 raid5_show_preread_threshold,
5356 raid5_store_preread_threshold);
5357
3f294f4f 5358static ssize_t
fd01b88c 5359stripe_cache_active_show(struct mddev *mddev, char *page)
3f294f4f 5360{
d1688a6d 5361 struct r5conf *conf = mddev->private;
96de1e66
N		 5362 if (conf)
5363 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
5364 else
5365 return 0;
3f294f4f
N		 5366}
5367
96de1e66
N		 5368static struct md_sysfs_entry
5369raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
3f294f4f 5370
b721420e
SL		 5371static ssize_t
5372raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
5373{
5374 struct r5conf *conf = mddev->private;
5375 if (conf)
5376 return sprintf(page, "%d\n", conf->worker_cnt_per_group);
5377 else
5378 return 0;
5379}
5380
60aaf933 5381static int alloc_thread_groups(struct r5conf *conf, int cnt,
5382 int *group_cnt,
5383 int *worker_cnt_per_group,
5384 struct r5worker_group **worker_groups);
b721420e
SL		 5385static ssize_t
5386raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
5387{
5388 struct r5conf *conf = mddev->private;
5389 unsigned long new;
5390 int err;
60aaf933 5391 struct r5worker_group *new_groups, *old_groups;
5392 int group_cnt, worker_cnt_per_group;
b721420e
SL		 5393
5394 if (len >= PAGE_SIZE)
5395 return -EINVAL;
5396 if (!conf)
5397 return -ENODEV;
5398
5399 if (kstrtoul(page, 10, &new))
5400 return -EINVAL;
5401
5402 if (new == conf->worker_cnt_per_group)
5403 return len;
5404
5405 mddev_suspend(mddev);
5406
5407 old_groups = conf->worker_groups;
d206dcfa 5408 if (old_groups)
5409 flush_workqueue(raid5_wq);
5410
60aaf933 5411 err = alloc_thread_groups(conf, new,
5412 &group_cnt, &worker_cnt_per_group,
5413 &new_groups);
5414 if (!err) {
5415 spin_lock_irq(&conf->device_lock);
5416 conf->group_cnt = group_cnt;
5417 conf->worker_cnt_per_group = worker_cnt_per_group;
5418 conf->worker_groups = new_groups;
5419 spin_unlock_irq(&conf->device_lock);
b721420e 5420
b721420e
SL		 5421 if (old_groups)
5422 kfree(old_groups[0].workers);
5423 kfree(old_groups);
5424 }
5425
5426 mddev_resume(mddev);
5427
5428 if (err)
5429 return err;
5430 return len;
5431}
5432
5433static struct md_sysfs_entry
5434raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
5435 raid5_show_group_thread_cnt,
5436 raid5_store_group_thread_cnt);
5437
007583c9 5438static struct attribute *raid5_attrs[] = {
3f294f4f
N		 5439 &raid5_stripecache_size.attr,
5440 &raid5_stripecache_active.attr,
8b3e6cdc 5441 &raid5_preread_bypass_threshold.attr,
b721420e 5442 &raid5_group_thread_cnt.attr,
3f294f4f
N		 5443 NULL,
5444};
007583c9
N		 5445static struct attribute_group raid5_attrs_group = {
5446 .name = NULL,
5447 .attrs = raid5_attrs,
3f294f4f
N		 5448};
5449
60aaf933 5450static int alloc_thread_groups(struct r5conf *conf, int cnt,
5451 int *group_cnt,
5452 int *worker_cnt_per_group,
5453 struct r5worker_group **worker_groups)
851c30c9 5454{
566c09c5 5455 int i, j, k;
851c30c9
SL		 5456 ssize_t size;
5457 struct r5worker *workers;
5458
60aaf933 5459 *worker_cnt_per_group = cnt;
851c30c9 5460 if (cnt == 0) {
60aaf933 5461 *group_cnt = 0;
5462 *worker_groups = NULL;
851c30c9
SL		 5463 return 0;
5464 }
60aaf933 5465 *group_cnt = num_possible_nodes();
851c30c9 5466 size = sizeof(struct r5worker) * cnt;
60aaf933 5467 workers = kzalloc(size * *group_cnt, GFP_NOIO);
5468 *worker_groups = kzalloc(sizeof(struct r5worker_group) *
5469 *group_cnt, GFP_NOIO);
5470 if (!*worker_groups || !workers) {
851c30c9 5471 kfree(workers);
60aaf933 5472 kfree(*worker_groups);
851c30c9
SL		 5473 return -ENOMEM;
5474 }
5475
60aaf933 5476 for (i = 0; i < *group_cnt; i++) {
851c30c9
SL		 5477 struct r5worker_group *group;
5478
0c775d52 5479 group = &(*worker_groups)[i];
851c30c9
SL		 5480 INIT_LIST_HEAD(&group->handle_list);
5481 group->conf = conf;
5482 group->workers = workers + i * cnt;
5483
5484 for (j = 0; j < cnt; j++) {
566c09c5
SL		 5485 struct r5worker *worker = group->workers + j;
5486 worker->group = group;
5487 INIT_WORK(&worker->work, raid5_do_work);
5488
5489 for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++)
5490 INIT_LIST_HEAD(worker->temp_inactive_list + k);
851c30c9
SL		 5491 }
5492 }
5493
5494 return 0;
5495}
5496
5497static void free_thread_groups(struct r5conf *conf)
5498{
5499 if (conf->worker_groups)
5500 kfree(conf->worker_groups[0].workers);
5501 kfree(conf->worker_groups);
5502 conf->worker_groups = NULL;
5503}
5504
80c3a6ce 5505static sector_t
fd01b88c 5506raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
80c3a6ce 5507{
d1688a6d 5508 struct r5conf *conf = mddev->private;
80c3a6ce
DW		 5509
5510 if (!sectors)
5511 sectors = mddev->dev_sectors;
5e5e3e78 5512 if (!raid_disks)
7ec05478 5513 /* size is defined by the smallest of previous and new size */
5e5e3e78 5514 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
80c3a6ce 5515
9d8f0363 5516 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
664e7c41 5517 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
80c3a6ce
DW		 5518 return sectors * (raid_disks - conf->max_degraded);
5519}
5520
789b5e03
ON		 5521static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
5522{
5523 safe_put_page(percpu->spare_page);
5524 kfree(percpu->scribble);
5525 percpu->spare_page = NULL;
5526 percpu->scribble = NULL;
5527}
5528
5529static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
5530{
5531 if (conf->level == 6 && !percpu->spare_page)
5532 percpu->spare_page = alloc_page(GFP_KERNEL);
5533 if (!percpu->scribble)
5534 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
5535
5536 if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
5537 free_scratch_buffer(conf, percpu);
5538 return -ENOMEM;
5539 }
5540
5541 return 0;
5542}
5543
d1688a6d 5544static void raid5_free_percpu(struct r5conf *conf)
36d1c647 5545{
36d1c647
DW		 5546 unsigned long cpu;
5547
5548 if (!conf->percpu)
5549 return;
5550
36d1c647
DW		 5551#ifdef CONFIG_HOTPLUG_CPU
5552 unregister_cpu_notifier(&conf->cpu_notify);
5553#endif
789b5e03
ON		 5554
5555 get_online_cpus();
5556 for_each_possible_cpu(cpu)
5557 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
36d1c647
DW		 5558 put_online_cpus();
5559
5560 free_percpu(conf->percpu);
5561}
5562
d1688a6d 5563static void free_conf(struct r5conf *conf)
95fc17aa 5564{
851c30c9 5565 free_thread_groups(conf);
95fc17aa 5566 shrink_stripes(conf);
36d1c647 5567 raid5_free_percpu(conf);
95fc17aa
DW		 5568 kfree(conf->disks);
5569 kfree(conf->stripe_hashtbl);
5570 kfree(conf);
5571}
5572
36d1c647
DW		 5573#ifdef CONFIG_HOTPLUG_CPU
5574static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
5575 void *hcpu)
5576{
d1688a6d 5577 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
36d1c647
DW		 5578 long cpu = (long)hcpu;
5579 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
5580
5581 switch (action) {
5582 case CPU_UP_PREPARE:
5583 case CPU_UP_PREPARE_FROZEN:
789b5e03 5584 if (alloc_scratch_buffer(conf, percpu)) {
36d1c647
DW		 5585 pr_err("%s: failed memory allocation for cpu%ld\n",
5586 __func__, cpu);
55af6bb5 5587 return notifier_from_errno(-ENOMEM);
36d1c647
DW		 5588 }
5589 break;
5590 case CPU_DEAD:
5591 case CPU_DEAD_FROZEN:
789b5e03 5592 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
36d1c647
DW		 5593 break;
5594 default:
5595 break;
5596 }
5597 return NOTIFY_OK;
5598}
5599#endif
5600
d1688a6d 5601static int raid5_alloc_percpu(struct r5conf *conf)
36d1c647
DW		 5602{
5603 unsigned long cpu;
789b5e03 5604 int err = 0;
36d1c647 5605
789b5e03
ON		 5606 conf->percpu = alloc_percpu(struct raid5_percpu);
5607 if (!conf->percpu)
36d1c647 5608 return -ENOMEM;
789b5e03
ON		 5609
5610#ifdef CONFIG_HOTPLUG_CPU
5611 conf->cpu_notify.notifier_call = raid456_cpu_notify;
5612 conf->cpu_notify.priority = 0;
5613 err = register_cpu_notifier(&conf->cpu_notify);
5614 if (err)
5615 return err;
5616#endif
36d1c647
DW		 5617
5618 get_online_cpus();
36d1c647 5619 for_each_present_cpu(cpu) {
789b5e03
ON		 5620 err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
5621 if (err) {
5622 pr_err("%s: failed memory allocation for cpu%ld\n",
5623 __func__, cpu);
36d1c647
DW		 5624 break;
5625 }
36d1c647 5626 }
36d1c647
DW		 5627 put_online_cpus();
5628
5629 return err;
5630}
5631
d1688a6d 5632static struct r5conf *setup_conf(struct mddev *mddev)
1da177e4 5633{
d1688a6d 5634 struct r5conf *conf;
5e5e3e78 5635 int raid_disk, memory, max_disks;
3cb03002 5636 struct md_rdev *rdev;
1da177e4 5637 struct disk_info *disk;
0232605d 5638 char pers_name[6];
566c09c5 5639 int i;
60aaf933 5640 int group_cnt, worker_cnt_per_group;
5641 struct r5worker_group *new_group;
1da177e4 5642
91adb564
N		 5643 if (mddev->new_level != 5
5644 && mddev->new_level != 4
5645 && mddev->new_level != 6) {
0c55e022 5646 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
91adb564
N		 5647 mdname(mddev), mddev->new_level);
5648 return ERR_PTR(-EIO);
1da177e4 5649 }
91adb564
N		 5650 if ((mddev->new_level == 5
5651 && !algorithm_valid_raid5(mddev->new_layout)) ||
5652 (mddev->new_level == 6
5653 && !algorithm_valid_raid6(mddev->new_layout))) {
0c55e022 5654 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
91adb564
N		 5655 mdname(mddev), mddev->new_layout);
5656 return ERR_PTR(-EIO);
99c0fb5f 5657 }
91adb564 5658 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
0c55e022 5659 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
91adb564
N		 5660 mdname(mddev), mddev->raid_disks);
5661 return ERR_PTR(-EINVAL);
4bbf3771
N		 5662 }
5663
664e7c41
AN		 5664 if (!mddev->new_chunk_sectors ||
5665 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
5666 !is_power_of_2(mddev->new_chunk_sectors)) {
0c55e022
N		 5667 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
5668 mdname(mddev), mddev->new_chunk_sectors << 9);
91adb564 5669 return ERR_PTR(-EINVAL);
f6705578
N		 5670 }
5671
d1688a6d 5672 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
91adb564 5673 if (conf == NULL)
1da177e4 5674 goto abort;
851c30c9 5675 /* Don't enable multi-threading by default*/
60aaf933 5676 if (!alloc_thread_groups(conf, 0, &group_cnt, &worker_cnt_per_group,
5677 &new_group)) {
5678 conf->group_cnt = group_cnt;
5679 conf->worker_cnt_per_group = worker_cnt_per_group;
5680 conf->worker_groups = new_group;
5681 } else
851c30c9 5682 goto abort;
f5efd45a 5683 spin_lock_init(&conf->device_lock);
c46501b2 5684 seqcount_init(&conf->gen_lock);
f5efd45a
DW		 5685 init_waitqueue_head(&conf->wait_for_stripe);
5686 init_waitqueue_head(&conf->wait_for_overlap);
5687 INIT_LIST_HEAD(&conf->handle_list);
5688 INIT_LIST_HEAD(&conf->hold_list);
5689 INIT_LIST_HEAD(&conf->delayed_list);
5690 INIT_LIST_HEAD(&conf->bitmap_list);
773ca82f 5691 init_llist_head(&conf->released_stripes);
f5efd45a
DW		 5692 atomic_set(&conf->active_stripes, 0);
5693 atomic_set(&conf->preread_active_stripes, 0);
5694 atomic_set(&conf->active_aligned_reads, 0);
5695 conf->bypass_threshold = BYPASS_THRESHOLD;
d890fa2b 5696 conf->recovery_disabled = mddev->recovery_disabled - 1;
91adb564
N		 5697
5698 conf->raid_disks = mddev->raid_disks;
5699 if (mddev->reshape_position == MaxSector)
5700 conf->previous_raid_disks = mddev->raid_disks;
5701 else
f6705578 5702 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
5e5e3e78
N		 5703 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
5704 conf->scribble_len = scribble_len(max_disks);
f6705578 5705
5e5e3e78 5706 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
b55e6bfc
N		 5707 GFP_KERNEL);
5708 if (!conf->disks)
5709 goto abort;
9ffae0cf 5710
1da177e4
LT		 5711 conf->mddev = mddev;
5712
fccddba0 5713 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
1da177e4 5714 goto abort;
1da177e4 5715
566c09c5
SL		 5716 /* We init hash_locks[0] separately to that it can be used
5717 * as the reference lock in the spin_lock_nest_lock() call
5718 * in lock_all_device_hash_locks_irq in order to convince
5719 * lockdep that we know what we are doing.
5720 */
5721 spin_lock_init(conf->hash_locks);
5722 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
5723 spin_lock_init(conf->hash_locks + i);
5724
5725 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5726 INIT_LIST_HEAD(conf->inactive_list + i);
5727
5728 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5729 INIT_LIST_HEAD(conf->temp_inactive_list + i);
5730
36d1c647
DW		 5731 conf->level = mddev->new_level;
5732 if (raid5_alloc_percpu(conf) != 0)
5733 goto abort;
5734
0c55e022 5735 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
1da177e4 5736
dafb20fa 5737 rdev_for_each(rdev, mddev) {
1da177e4 5738 raid_disk = rdev->raid_disk;
5e5e3e78 5739 if (raid_disk >= max_disks
1da177e4
LT		 5740 || raid_disk < 0)
5741 continue;
5742 disk = conf->disks + raid_disk;
5743
17045f52
N		 5744 if (test_bit(Replacement, &rdev->flags)) {
5745 if (disk->replacement)
5746 goto abort;
5747 disk->replacement = rdev;
5748 } else {
5749 if (disk->rdev)
5750 goto abort;
5751 disk->rdev = rdev;
5752 }
1da177e4 5753
b2d444d7 5754 if (test_bit(In_sync, &rdev->flags)) {
1da177e4 5755 char b[BDEVNAME_SIZE];
0c55e022
N		 5756 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
5757 " disk %d\n",
5758 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
d6b212f4 5759 } else if (rdev->saved_raid_disk != raid_disk)
8c2e870a
NB		 5760 /* Cannot rely on bitmap to complete recovery */
5761 conf->fullsync = 1;
1da177e4
LT		 5762 }
5763
09c9e5fa 5764 conf->chunk_sectors = mddev->new_chunk_sectors;
91adb564 5765 conf->level = mddev->new_level;
16a53ecc
N		 5766 if (conf->level == 6)
5767 conf->max_degraded = 2;
5768 else
5769 conf->max_degraded = 1;
91adb564 5770 conf->algorithm = mddev->new_layout;
fef9c61f 5771 conf->reshape_progress = mddev->reshape_position;
e183eaed 5772 if (conf->reshape_progress != MaxSector) {
09c9e5fa 5773 conf->prev_chunk_sectors = mddev->chunk_sectors;
e183eaed
N		 5774 conf->prev_algo = mddev->layout;
5775 }
1da177e4 5776
91adb564 5777 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
5e5e3e78 5778 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4bda556a 5779 atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
566c09c5 5780 if (grow_stripes(conf, NR_STRIPES)) {
91adb564 5781 printk(KERN_ERR
0c55e022
N		 5782 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5783 mdname(mddev), memory);
91adb564
N		 5784 goto abort;
5785 } else
0c55e022
N		 5786 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
5787 mdname(mddev), memory);
1da177e4 5788
0232605d
N		 5789 sprintf(pers_name, "raid%d", mddev->new_level);
5790 conf->thread = md_register_thread(raid5d, mddev, pers_name);
91adb564
N		 5791 if (!conf->thread) {
5792 printk(KERN_ERR
0c55e022 5793 "md/raid:%s: couldn't allocate thread.\n",
91adb564 5794 mdname(mddev));
16a53ecc
N		 5795 goto abort;
5796 }
91adb564
N		 5797
5798 return conf;
5799
5800 abort:
5801 if (conf) {
95fc17aa 5802 free_conf(conf);
91adb564
N		 5803 return ERR_PTR(-EIO);
5804 } else
5805 return ERR_PTR(-ENOMEM);
5806}
5807
c148ffdc
N		 5808
5809static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
5810{
5811 switch (algo) {
5812 case ALGORITHM_PARITY_0:
5813 if (raid_disk < max_degraded)
5814 return 1;
5815 break;
5816 case ALGORITHM_PARITY_N:
5817 if (raid_disk >= raid_disks - max_degraded)
5818 return 1;
5819 break;
5820 case ALGORITHM_PARITY_0_6:
5821 if (raid_disk == 0 ||
5822 raid_disk == raid_disks - 1)
5823 return 1;
5824 break;
5825 case ALGORITHM_LEFT_ASYMMETRIC_6:
5826 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5827 case ALGORITHM_LEFT_SYMMETRIC_6:
5828 case ALGORITHM_RIGHT_SYMMETRIC_6:
5829 if (raid_disk == raid_disks - 1)
5830 return 1;
5831 }
5832 return 0;
5833}
5834
fd01b88c 5835static int run(struct mddev *mddev)
91adb564 5836{
d1688a6d 5837 struct r5conf *conf;
9f7c2220 5838 int working_disks = 0;
c148ffdc 5839 int dirty_parity_disks = 0;
3cb03002 5840 struct md_rdev *rdev;
c148ffdc 5841 sector_t reshape_offset = 0;
17045f52 5842 int i;
b5254dd5
N		 5843 long long min_offset_diff = 0;
5844 int first = 1;
91adb564 5845
8c6ac868 5846 if (mddev->recovery_cp != MaxSector)
0c55e022 5847 printk(KERN_NOTICE "md/raid:%s: not clean"
8c6ac868
AN		 5848 " -- starting background reconstruction\n",
5849 mdname(mddev));
b5254dd5
N		 5850
5851 rdev_for_each(rdev, mddev) {
5852 long long diff;
5853 if (rdev->raid_disk < 0)
5854 continue;
5855 diff = (rdev->new_data_offset - rdev->data_offset);
5856 if (first) {
5857 min_offset_diff = diff;
5858 first = 0;
5859 } else if (mddev->reshape_backwards &&
5860 diff < min_offset_diff)
5861 min_offset_diff = diff;
5862 else if (!mddev->reshape_backwards &&
5863 diff > min_offset_diff)
5864 min_offset_diff = diff;
5865 }
5866
91adb564
N		 5867 if (mddev->reshape_position != MaxSector) {
5868 /* Check that we can continue the reshape.
b5254dd5
N		 5869 * Difficulties arise if the stripe we would write to
5870 * next is at or after the stripe we would read from next.
5871 * For a reshape that changes the number of devices, this
5872 * is only possible for a very short time, and mdadm makes
5873 * sure that time appears to have past before assembling
5874 * the array. So we fail if that time hasn't passed.
5875 * For a reshape that keeps the number of devices the same
5876 * mdadm must be monitoring the reshape can keeping the
5877 * critical areas read-only and backed up. It will start
5878 * the array in read-only mode, so we check for that.
91adb564
N		 5879 */
5880 sector_t here_new, here_old;
5881 int old_disks;
18b00334 5882 int max_degraded = (mddev->level == 6 ? 2 : 1);
91adb564 5883
88ce4930 5884 if (mddev->new_level != mddev->level) {
0c55e022 5885 printk(KERN_ERR "md/raid:%s: unsupported reshape "
91adb564
N		 5886 "required - aborting.\n",
5887 mdname(mddev));
5888 return -EINVAL;
5889 }
91adb564
N		 5890 old_disks = mddev->raid_disks - mddev->delta_disks;
5891 /* reshape_position must be on a new-stripe boundary, and one
5892 * further up in new geometry must map after here in old
5893 * geometry.
5894 */
5895 here_new = mddev->reshape_position;
664e7c41 5896 if (sector_div(here_new, mddev->new_chunk_sectors *
91adb564 5897 (mddev->raid_disks - max_degraded))) {
0c55e022
N		 5898 printk(KERN_ERR "md/raid:%s: reshape_position not "
5899 "on a stripe boundary\n", mdname(mddev));
91adb564
N		 5900 return -EINVAL;
5901 }
c148ffdc 5902 reshape_offset = here_new * mddev->new_chunk_sectors;
91adb564
N		 5903 /* here_new is the stripe we will write to */
5904 here_old = mddev->reshape_position;
9d8f0363 5905 sector_div(here_old, mddev->chunk_sectors *
91adb564
N		 5906 (old_disks-max_degraded));
5907 /* here_old is the first stripe that we might need to read
5908 * from */
67ac6011 5909 if (mddev->delta_disks == 0) {
b5254dd5
N		 5910 if ((here_new * mddev->new_chunk_sectors !=
5911 here_old * mddev->chunk_sectors)) {
5912 printk(KERN_ERR "md/raid:%s: reshape position is"
5913 " confused - aborting\n", mdname(mddev));
5914 return -EINVAL;
5915 }
67ac6011 5916 /* We cannot be sure it is safe to start an in-place
b5254dd5 5917 * reshape. It is only safe if user-space is monitoring
67ac6011
N		 5918 * and taking constant backups.
5919 * mdadm always starts a situation like this in
5920 * readonly mode so it can take control before
5921 * allowing any writes. So just check for that.
5922 */
b5254dd5
N		 5923 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
5924 abs(min_offset_diff) >= mddev->new_chunk_sectors)
5925 /* not really in-place - so OK */;
5926 else if (mddev->ro == 0) {
5927 printk(KERN_ERR "md/raid:%s: in-place reshape "
5928 "must be started in read-only mode "
5929 "- aborting\n",
0c55e022 5930 mdname(mddev));
67ac6011
N		 5931 return -EINVAL;
5932 }
2c810cdd 5933 } else if (mddev->reshape_backwards
b5254dd5 5934 ? (here_new * mddev->new_chunk_sectors + min_offset_diff <=
67ac6011
N		 5935 here_old * mddev->chunk_sectors)
5936 : (here_new * mddev->new_chunk_sectors >=
b5254dd5 5937 here_old * mddev->chunk_sectors + (-min_offset_diff))) {
91adb564 5938 /* Reading from the same stripe as writing to - bad */
0c55e022
N		 5939 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
5940 "auto-recovery - aborting.\n",
5941 mdname(mddev));
91adb564
N		 5942 return -EINVAL;
5943 }
0c55e022
N		 5944 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
5945 mdname(mddev));
91adb564
N		 5946 /* OK, we should be able to continue; */
5947 } else {
5948 BUG_ON(mddev->level != mddev->new_level);
5949 BUG_ON(mddev->layout != mddev->new_layout);
664e7c41 5950 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
91adb564 5951 BUG_ON(mddev->delta_disks != 0);
1da177e4 5952 }
91adb564 5953
245f46c2
N		 5954 if (mddev->private == NULL)
5955 conf = setup_conf(mddev);
5956 else
5957 conf = mddev->private;
5958
91adb564
N		 5959 if (IS_ERR(conf))
5960 return PTR_ERR(conf);
5961
b5254dd5 5962 conf->min_offset_diff = min_offset_diff;
91adb564
N		 5963 mddev->thread = conf->thread;
5964 conf->thread = NULL;
5965 mddev->private = conf;
5966
17045f52
N		 5967 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
5968 i++) {
5969 rdev = conf->disks[i].rdev;
5970 if (!rdev && conf->disks[i].replacement) {
5971 /* The replacement is all we have yet */
5972 rdev = conf->disks[i].replacement;
5973 conf->disks[i].replacement = NULL;
5974 clear_bit(Replacement, &rdev->flags);
5975 conf->disks[i].rdev = rdev;
5976 }
5977 if (!rdev)
c148ffdc 5978 continue;
17045f52
N		 5979 if (conf->disks[i].replacement &&
5980 conf->reshape_progress != MaxSector) {
5981 /* replacements and reshape simply do not mix. */
5982 printk(KERN_ERR "md: cannot handle concurrent "
5983 "replacement and reshape.\n");
5984 goto abort;
5985 }
2f115882 5986 if (test_bit(In_sync, &rdev->flags)) {
91adb564 5987 working_disks++;
2f115882
N		 5988 continue;
5989 }
c148ffdc
N		 5990 /* This disc is not fully in-sync. However if it
5991 * just stored parity (beyond the recovery_offset),
5992 * when we don't need to be concerned about the
5993 * array being dirty.
5994 * When reshape goes 'backwards', we never have
5995 * partially completed devices, so we only need
5996 * to worry about reshape going forwards.
5997 */
5998 /* Hack because v0.91 doesn't store recovery_offset properly. */
5999 if (mddev->major_version == 0 &&
6000 mddev->minor_version > 90)
6001 rdev->recovery_offset = reshape_offset;
5026d7a9 6002
c148ffdc
N		 6003 if (rdev->recovery_offset < reshape_offset) {
6004 /* We need to check old and new layout */
6005 if (!only_parity(rdev->raid_disk,
6006 conf->algorithm,
6007 conf->raid_disks,
6008 conf->max_degraded))
6009 continue;
6010 }
6011 if (!only_parity(rdev->raid_disk,
6012 conf->prev_algo,
6013 conf->previous_raid_disks,
6014 conf->max_degraded))
6015 continue;
6016 dirty_parity_disks++;
6017 }
91adb564 6018
17045f52
N		 6019 /*
6020 * 0 for a fully functional array, 1 or 2 for a degraded array.
6021 */
908f4fbd 6022 mddev->degraded = calc_degraded(conf);
91adb564 6023
674806d6 6024 if (has_failed(conf)) {
0c55e022 6025 printk(KERN_ERR "md/raid:%s: not enough operational devices"
1da177e4 6026 " (%d/%d failed)\n",
02c2de8c 6027 mdname(mddev), mddev->degraded, conf->raid_disks);
1da177e4
LT		 6028 goto abort;
6029 }
6030
91adb564 6031 /* device size must be a multiple of chunk size */
9d8f0363 6032 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
91adb564
N		 6033 mddev->resync_max_sectors = mddev->dev_sectors;
6034
c148ffdc 6035 if (mddev->degraded > dirty_parity_disks &&
1da177e4 6036 mddev->recovery_cp != MaxSector) {
6ff8d8ec
N		 6037 if (mddev->ok_start_degraded)
6038 printk(KERN_WARNING
0c55e022
N		 6039 "md/raid:%s: starting dirty degraded array"
6040 " - data corruption possible.\n",
6ff8d8ec
N		 6041 mdname(mddev));
6042 else {
6043 printk(KERN_ERR
0c55e022 6044 "md/raid:%s: cannot start dirty degraded array.\n",
6ff8d8ec
N		 6045 mdname(mddev));
6046 goto abort;
6047 }
1da177e4
LT		 6048 }
6049
1da177e4 6050 if (mddev->degraded == 0)
0c55e022
N		 6051 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
6052 " devices, algorithm %d\n", mdname(mddev), conf->level,
e183eaed
N		 6053 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
6054 mddev->new_layout);
1da177e4 6055 else
0c55e022
N		 6056 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
6057 " out of %d devices, algorithm %d\n",
6058 mdname(mddev), conf->level,
6059 mddev->raid_disks - mddev->degraded,
6060 mddev->raid_disks, mddev->new_layout);
1da177e4
LT		 6061
6062 print_raid5_conf(conf);
6063
fef9c61f 6064 if (conf->reshape_progress != MaxSector) {
fef9c61f 6065 conf->reshape_safe = conf->reshape_progress;
f6705578
N		 6066 atomic_set(&conf->reshape_stripes, 0);
6067 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6068 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6069 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6070 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6071 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 6072 "reshape");
f6705578
N		 6073 }
6074
1da177e4
LT		 6075
6076 /* Ok, everything is just fine now */
a64c876f
N		 6077 if (mddev->to_remove == &raid5_attrs_group)
6078 mddev->to_remove = NULL;
00bcb4ac
N		 6079 else if (mddev->kobj.sd &&
6080 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5e55e2f5 6081 printk(KERN_WARNING
4a5add49 6082 "raid5: failed to create sysfs attributes for %s\n",
5e55e2f5 6083 mdname(mddev));
4a5add49 6084 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7a5febe9 6085
4a5add49 6086 if (mddev->queue) {
9f7c2220 6087 int chunk_size;
620125f2 6088 bool discard_supported = true;
4a5add49
N		 6089 /* read-ahead size must cover two whole stripes, which
6090 * is 2 * (datadisks) * chunksize where 'n' is the
6091 * number of raid devices
6092 */
6093 int data_disks = conf->previous_raid_disks - conf->max_degraded;
6094 int stripe = data_disks *
6095 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
6096 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6097 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
91adb564 6098
4a5add49 6099 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
f022b2fd 6100
11d8a6e3
N		 6101 mddev->queue->backing_dev_info.congested_data = mddev;
6102 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
7a5febe9 6103
9f7c2220
N		 6104 chunk_size = mddev->chunk_sectors << 9;
6105 blk_queue_io_min(mddev->queue, chunk_size);
6106 blk_queue_io_opt(mddev->queue, chunk_size *
6107 (conf->raid_disks - conf->max_degraded));
c78afc62 6108 mddev->queue->limits.raid_partial_stripes_expensive = 1;
620125f2
SL		 6109 /*
6110 * We can only discard a whole stripe. It doesn't make sense to
6111 * discard data disk but write parity disk
6112 */
6113 stripe = stripe * PAGE_SIZE;
4ac6875e
N		 6114 /* Round up to power of 2, as discard handling
6115 * currently assumes that */
6116 while ((stripe-1) & stripe)
6117 stripe = (stripe | (stripe-1)) + 1;
620125f2
SL		 6118 mddev->queue->limits.discard_alignment = stripe;
6119 mddev->queue->limits.discard_granularity = stripe;
6120 /*
6121 * unaligned part of discard request will be ignored, so can't
6122 * guarantee discard_zerors_data
6123 */
6124 mddev->queue->limits.discard_zeroes_data = 0;
8f6c2e4b 6125
5026d7a9
PA		 6126 blk_queue_max_write_same_sectors(mddev->queue, 0);
6127
05616be5 6128 rdev_for_each(rdev, mddev) {
9f7c2220
N		 6129 disk_stack_limits(mddev->gendisk, rdev->bdev,
6130 rdev->data_offset << 9);
05616be5
N		 6131 disk_stack_limits(mddev->gendisk, rdev->bdev,
6132 rdev->new_data_offset << 9);
620125f2
SL		 6133 /*
6134 * discard_zeroes_data is required, otherwise data
6135 * could be lost. Consider a scenario: discard a stripe
6136 * (the stripe could be inconsistent if
6137 * discard_zeroes_data is 0); write one disk of the
6138 * stripe (the stripe could be inconsistent again
6139 * depending on which disks are used to calculate
6140 * parity); the disk is broken; The stripe data of this
6141 * disk is lost.
6142 */
6143 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
6144 !bdev_get_queue(rdev->bdev)->
6145 limits.discard_zeroes_data)
6146 discard_supported = false;
05616be5 6147 }
620125f2
SL		 6148
6149 if (discard_supported &&
6150 mddev->queue->limits.max_discard_sectors >= stripe &&
6151 mddev->queue->limits.discard_granularity >= stripe)
6152 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
6153 mddev->queue);
6154 else
6155 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
6156 mddev->queue);
9f7c2220 6157 }
23032a0e 6158
1da177e4
LT		 6159 return 0;
6160abort:
01f96c0a 6161 md_unregister_thread(&mddev->thread);
e4f869d9
N		 6162 print_raid5_conf(conf);
6163 free_conf(conf);
1da177e4 6164 mddev->private = NULL;
0c55e022 6165 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
1da177e4
LT		 6166 return -EIO;
6167}
6168
fd01b88c 6169static int stop(struct mddev *mddev)
1da177e4 6170{
d1688a6d 6171 struct r5conf *conf = mddev->private;
1da177e4 6172
01f96c0a 6173 md_unregister_thread(&mddev->thread);
11d8a6e3
N		 6174 if (mddev->queue)
6175 mddev->queue->backing_dev_info.congested_fn = NULL;
95fc17aa 6176 free_conf(conf);
a64c876f
N		 6177 mddev->private = NULL;
6178 mddev->to_remove = &raid5_attrs_group;
1da177e4
LT		 6179 return 0;
6180}
6181
fd01b88c 6182static void status(struct seq_file *seq, struct mddev *mddev)
1da177e4 6183{
d1688a6d 6184 struct r5conf *conf = mddev->private;
1da177e4
LT		 6185 int i;
6186
9d8f0363
AN		 6187 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
6188 mddev->chunk_sectors / 2, mddev->layout);
02c2de8c 6189 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
1da177e4
LT		 6190 for (i = 0; i < conf->raid_disks; i++)
6191 seq_printf (seq, "%s",
6192 conf->disks[i].rdev &&
b2d444d7 6193 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
1da177e4 6194 seq_printf (seq, "]");
1da177e4
LT		 6195}
6196
d1688a6d 6197static void print_raid5_conf (struct r5conf *conf)
1da177e4
LT		 6198{
6199 int i;
6200 struct disk_info *tmp;
6201
0c55e022 6202 printk(KERN_DEBUG "RAID conf printout:\n");
1da177e4
LT		 6203 if (!conf) {
6204 printk("(conf==NULL)\n");
6205 return;
6206 }
0c55e022
N		 6207 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
6208 conf->raid_disks,
6209 conf->raid_disks - conf->mddev->degraded);
1da177e4
LT		 6210
6211 for (i = 0; i < conf->raid_disks; i++) {
6212 char b[BDEVNAME_SIZE];
6213 tmp = conf->disks + i;
6214 if (tmp->rdev)
0c55e022
N		 6215 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
6216 i, !test_bit(Faulty, &tmp->rdev->flags),
6217 bdevname(tmp->rdev->bdev, b));
1da177e4
LT		 6218 }
6219}
6220
fd01b88c 6221static int raid5_spare_active(struct mddev *mddev)
1da177e4
LT		 6222{
6223 int i;
d1688a6d 6224 struct r5conf *conf = mddev->private;
1da177e4 6225 struct disk_info *tmp;
6b965620
N		 6226 int count = 0;
6227 unsigned long flags;
1da177e4
LT		 6228
6229 for (i = 0; i < conf->raid_disks; i++) {
6230 tmp = conf->disks + i;
dd054fce
N		 6231 if (tmp->replacement
6232 && tmp->replacement->recovery_offset == MaxSector
6233 && !test_bit(Faulty, &tmp->replacement->flags)
6234 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
6235 /* Replacement has just become active. */
6236 if (!tmp->rdev
6237 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
6238 count++;
6239 if (tmp->rdev) {
6240 /* Replaced device not technically faulty,
6241 * but we need to be sure it gets removed
6242 * and never re-added.
6243 */
6244 set_bit(Faulty, &tmp->rdev->flags);
6245 sysfs_notify_dirent_safe(
6246 tmp->rdev->sysfs_state);
6247 }
6248 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
6249 } else if (tmp->rdev
70fffd0b 6250 && tmp->rdev->recovery_offset == MaxSector
b2d444d7 6251 && !test_bit(Faulty, &tmp->rdev->flags)
c04be0aa 6252 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
6b965620 6253 count++;
43c73ca4 6254 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
1da177e4
LT		 6255 }
6256 }
6b965620 6257 spin_lock_irqsave(&conf->device_lock, flags);
908f4fbd 6258 mddev->degraded = calc_degraded(conf);
6b965620 6259 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4 6260 print_raid5_conf(conf);
6b965620 6261 return count;
1da177e4
LT		 6262}
6263
b8321b68 6264static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1da177e4 6265{
d1688a6d 6266 struct r5conf *conf = mddev->private;
1da177e4 6267 int err = 0;
b8321b68 6268 int number = rdev->raid_disk;
657e3e4d 6269 struct md_rdev **rdevp;
1da177e4
LT		 6270 struct disk_info *p = conf->disks + number;
6271
6272 print_raid5_conf(conf);
657e3e4d
N		 6273 if (rdev == p->rdev)
6274 rdevp = &p->rdev;
6275 else if (rdev == p->replacement)
6276 rdevp = &p->replacement;
6277 else
6278 return 0;
6279
6280 if (number >= conf->raid_disks &&
6281 conf->reshape_progress == MaxSector)
6282 clear_bit(In_sync, &rdev->flags);
6283
6284 if (test_bit(In_sync, &rdev->flags) ||
6285 atomic_read(&rdev->nr_pending)) {
6286 err = -EBUSY;
6287 goto abort;
6288 }
6289 /* Only remove non-faulty devices if recovery
6290 * isn't possible.
6291 */
6292 if (!test_bit(Faulty, &rdev->flags) &&
6293 mddev->recovery_disabled != conf->recovery_disabled &&
6294 !has_failed(conf) &&
dd054fce 6295 (!p->replacement || p->replacement == rdev) &&
657e3e4d
N		 6296 number < conf->raid_disks) {
6297 err = -EBUSY;
6298 goto abort;
6299 }
6300 *rdevp = NULL;
6301 synchronize_rcu();
6302 if (atomic_read(&rdev->nr_pending)) {
6303 /* lost the race, try later */
6304 err = -EBUSY;
6305 *rdevp = rdev;
dd054fce
N		 6306 } else if (p->replacement) {
6307 /* We must have just cleared 'rdev' */
6308 p->rdev = p->replacement;
6309 clear_bit(Replacement, &p->replacement->flags);
6310 smp_mb(); /* Make sure other CPUs may see both as identical
6311 * but will never see neither - if they are careful
6312 */
6313 p->replacement = NULL;
6314 clear_bit(WantReplacement, &rdev->flags);
6315 } else
6316 /* We might have just removed the Replacement as faulty-
6317 * clear the bit just in case
6318 */
6319 clear_bit(WantReplacement, &rdev->flags);
1da177e4
LT		 6320abort:
6321
6322 print_raid5_conf(conf);
6323 return err;
6324}
6325
fd01b88c 6326static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1da177e4 6327{
d1688a6d 6328 struct r5conf *conf = mddev->private;
199050ea 6329 int err = -EEXIST;
1da177e4
LT		 6330 int disk;
6331 struct disk_info *p;
6c2fce2e
NB		 6332 int first = 0;
6333 int last = conf->raid_disks - 1;
1da177e4 6334
7f0da59b
N		 6335 if (mddev->recovery_disabled == conf->recovery_disabled)
6336 return -EBUSY;
6337
dc10c643 6338 if (rdev->saved_raid_disk < 0 && has_failed(conf))
1da177e4 6339 /* no point adding a device */
199050ea 6340 return -EINVAL;
1da177e4 6341
6c2fce2e
NB		 6342 if (rdev->raid_disk >= 0)
6343 first = last = rdev->raid_disk;
1da177e4
LT		 6344
6345 /*
16a53ecc
N		 6346 * find the disk ... but prefer rdev->saved_raid_disk
6347 * if possible.
1da177e4 6348 */
16a53ecc 6349 if (rdev->saved_raid_disk >= 0 &&
6c2fce2e 6350 rdev->saved_raid_disk >= first &&
16a53ecc 6351 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5cfb22a1
N		 6352 first = rdev->saved_raid_disk;
6353
6354 for (disk = first; disk <= last; disk++) {
7bfec5f3
N		 6355 p = conf->disks + disk;
6356 if (p->rdev == NULL) {
b2d444d7 6357 clear_bit(In_sync, &rdev->flags);
1da177e4 6358 rdev->raid_disk = disk;
199050ea 6359 err = 0;
72626685
N		 6360 if (rdev->saved_raid_disk != disk)
6361 conf->fullsync = 1;
d6065f7b 6362 rcu_assign_pointer(p->rdev, rdev);
5cfb22a1 6363 goto out;
1da177e4 6364 }
5cfb22a1
N		 6365 }
6366 for (disk = first; disk <= last; disk++) {
6367 p = conf->disks + disk;
7bfec5f3
N		 6368 if (test_bit(WantReplacement, &p->rdev->flags) &&
6369 p->replacement == NULL) {
6370 clear_bit(In_sync, &rdev->flags);
6371 set_bit(Replacement, &rdev->flags);
6372 rdev->raid_disk = disk;
6373 err = 0;
6374 conf->fullsync = 1;
6375 rcu_assign_pointer(p->replacement, rdev);
6376 break;
6377 }
6378 }
5cfb22a1 6379out:
1da177e4 6380 print_raid5_conf(conf);
199050ea 6381 return err;
1da177e4
LT		 6382}
6383
fd01b88c 6384static int raid5_resize(struct mddev *mddev, sector_t sectors)
1da177e4
LT		 6385{
6386 /* no resync is happening, and there is enough space
6387 * on all devices, so we can resize.
6388 * We need to make sure resync covers any new space.
6389 * If the array is shrinking we should possibly wait until
6390 * any io in the removed space completes, but it hardly seems
6391 * worth it.
6392 */
a4a6125a 6393 sector_t newsize;
9d8f0363 6394 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
a4a6125a
N		 6395 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
6396 if (mddev->external_size &&
6397 mddev->array_sectors > newsize)
b522adcd 6398 return -EINVAL;
a4a6125a
N		 6399 if (mddev->bitmap) {
6400 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
6401 if (ret)
6402 return ret;
6403 }
6404 md_set_array_sectors(mddev, newsize);
f233ea5c 6405 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 6406 revalidate_disk(mddev->gendisk);
b098636c
N		 6407 if (sectors > mddev->dev_sectors &&
6408 mddev->recovery_cp > mddev->dev_sectors) {
58c0fed4 6409 mddev->recovery_cp = mddev->dev_sectors;
1da177e4
LT		 6410 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6411 }
58c0fed4 6412 mddev->dev_sectors = sectors;
4b5c7ae8 6413 mddev->resync_max_sectors = sectors;
1da177e4
LT		 6414 return 0;
6415}
6416
fd01b88c 6417static int check_stripe_cache(struct mddev *mddev)
01ee22b4
N		 6418{
6419 /* Can only proceed if there are plenty of stripe_heads.
6420 * We need a minimum of one full stripe,, and for sensible progress
6421 * it is best to have about 4 times that.
6422 * If we require 4 times, then the default 256 4K stripe_heads will
6423 * allow for chunk sizes up to 256K, which is probably OK.
6424 * If the chunk size is greater, user-space should request more
6425 * stripe_heads first.
6426 */
d1688a6d 6427 struct r5conf *conf = mddev->private;
01ee22b4
N		 6428 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
6429 > conf->max_nr_stripes ||
6430 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
6431 > conf->max_nr_stripes) {
0c55e022
N		 6432 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
6433 mdname(mddev),
01ee22b4
N		 6434 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
6435 / STRIPE_SIZE)*4);
6436 return 0;
6437 }
6438 return 1;
6439}
6440
fd01b88c 6441static int check_reshape(struct mddev *mddev)
29269553 6442{
d1688a6d 6443 struct r5conf *conf = mddev->private;
29269553 6444
88ce4930
N		 6445 if (mddev->delta_disks == 0 &&
6446 mddev->new_layout == mddev->layout &&
664e7c41 6447 mddev->new_chunk_sectors == mddev->chunk_sectors)
50ac168a 6448 return 0; /* nothing to do */
674806d6 6449 if (has_failed(conf))
ec32a2bd 6450 return -EINVAL;
fdcfbbb6 6451 if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
ec32a2bd
N		 6452 /* We might be able to shrink, but the devices must
6453 * be made bigger first.
6454 * For raid6, 4 is the minimum size.
6455 * Otherwise 2 is the minimum
6456 */
6457 int min = 2;
6458 if (mddev->level == 6)
6459 min = 4;
6460 if (mddev->raid_disks + mddev->delta_disks < min)
6461 return -EINVAL;
6462 }
29269553 6463
01ee22b4 6464 if (!check_stripe_cache(mddev))
29269553 6465 return -ENOSPC;
29269553 6466
e56108d6
N		 6467 return resize_stripes(conf, (conf->previous_raid_disks
6468 + mddev->delta_disks));
63c70c4f
N		 6469}
6470
fd01b88c 6471static int raid5_start_reshape(struct mddev *mddev)
63c70c4f 6472{
d1688a6d 6473 struct r5conf *conf = mddev->private;
3cb03002 6474 struct md_rdev *rdev;
63c70c4f 6475 int spares = 0;
c04be0aa 6476 unsigned long flags;
63c70c4f 6477
f416885e 6478 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
63c70c4f
N		 6479 return -EBUSY;
6480
01ee22b4
N		 6481 if (!check_stripe_cache(mddev))
6482 return -ENOSPC;
6483
30b67645
N		 6484 if (has_failed(conf))
6485 return -EINVAL;
6486
c6563a8c 6487 rdev_for_each(rdev, mddev) {
469518a3
N		 6488 if (!test_bit(In_sync, &rdev->flags)
6489 && !test_bit(Faulty, &rdev->flags))
29269553 6490 spares++;
c6563a8c 6491 }
63c70c4f 6492
f416885e 6493 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
29269553
N		 6494 /* Not enough devices even to make a degraded array
6495 * of that size
6496 */
6497 return -EINVAL;
6498
ec32a2bd
N		 6499 /* Refuse to reduce size of the array. Any reductions in
6500 * array size must be through explicit setting of array_size
6501 * attribute.
6502 */
6503 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
6504 < mddev->array_sectors) {
0c55e022 6505 printk(KERN_ERR "md/raid:%s: array size must be reduced "
ec32a2bd
N		 6506 "before number of disks\n", mdname(mddev));
6507 return -EINVAL;
6508 }
6509
f6705578 6510 atomic_set(&conf->reshape_stripes, 0);
29269553 6511 spin_lock_irq(&conf->device_lock);
c46501b2 6512 write_seqcount_begin(&conf->gen_lock);
29269553 6513 conf->previous_raid_disks = conf->raid_disks;
63c70c4f 6514 conf->raid_disks += mddev->delta_disks;
09c9e5fa
AN		 6515 conf->prev_chunk_sectors = conf->chunk_sectors;
6516 conf->chunk_sectors = mddev->new_chunk_sectors;
88ce4930
N		 6517 conf->prev_algo = conf->algorithm;
6518 conf->algorithm = mddev->new_layout;
05616be5
N		 6519 conf->generation++;
6520 /* Code that selects data_offset needs to see the generation update
6521 * if reshape_progress has been set - so a memory barrier needed.
6522 */
6523 smp_mb();
2c810cdd 6524 if (mddev->reshape_backwards)
fef9c61f
N		 6525 conf->reshape_progress = raid5_size(mddev, 0, 0);
6526 else
6527 conf->reshape_progress = 0;
6528 conf->reshape_safe = conf->reshape_progress;
c46501b2 6529 write_seqcount_end(&conf->gen_lock);
29269553
N		 6530 spin_unlock_irq(&conf->device_lock);
6531
4d77e3ba
N		 6532 /* Now make sure any requests that proceeded on the assumption
6533 * the reshape wasn't running - like Discard or Read - have
6534 * completed.
6535 */
6536 mddev_suspend(mddev);
6537 mddev_resume(mddev);
6538
29269553
N		 6539 /* Add some new drives, as many as will fit.
6540 * We know there are enough to make the newly sized array work.
3424bf6a
N		 6541 * Don't add devices if we are reducing the number of
6542 * devices in the array. This is because it is not possible
6543 * to correctly record the "partially reconstructed" state of
6544 * such devices during the reshape and confusion could result.
29269553 6545 */
87a8dec9 6546 if (mddev->delta_disks >= 0) {
dafb20fa 6547 rdev_for_each(rdev, mddev)
87a8dec9
N		 6548 if (rdev->raid_disk < 0 &&
6549 !test_bit(Faulty, &rdev->flags)) {
6550 if (raid5_add_disk(mddev, rdev) == 0) {
87a8dec9 6551 if (rdev->raid_disk
9d4c7d87 6552 >= conf->previous_raid_disks)
87a8dec9 6553 set_bit(In_sync, &rdev->flags);
9d4c7d87 6554 else
87a8dec9 6555 rdev->recovery_offset = 0;
36fad858
NK		 6556
6557 if (sysfs_link_rdev(mddev, rdev))
87a8dec9 6558 /* Failure here is OK */;
50da0840 6559 }
87a8dec9
N		 6560 } else if (rdev->raid_disk >= conf->previous_raid_disks
6561 && !test_bit(Faulty, &rdev->flags)) {
6562 /* This is a spare that was manually added */
6563 set_bit(In_sync, &rdev->flags);
87a8dec9 6564 }
29269553 6565
87a8dec9
N		 6566 /* When a reshape changes the number of devices,
6567 * ->degraded is measured against the larger of the
6568 * pre and post number of devices.
6569 */
ec32a2bd 6570 spin_lock_irqsave(&conf->device_lock, flags);
908f4fbd 6571 mddev->degraded = calc_degraded(conf);
ec32a2bd
N		 6572 spin_unlock_irqrestore(&conf->device_lock, flags);
6573 }
63c70c4f 6574 mddev->raid_disks = conf->raid_disks;
e516402c 6575 mddev->reshape_position = conf->reshape_progress;
850b2b42 6576 set_bit(MD_CHANGE_DEVS, &mddev->flags);
f6705578 6577
29269553
N		 6578 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6579 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6580 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6581 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6582 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
0da3c619 6583 "reshape");
29269553
N		 6584 if (!mddev->sync_thread) {
6585 mddev->recovery = 0;
6586 spin_lock_irq(&conf->device_lock);
ba8805b9 6587 write_seqcount_begin(&conf->gen_lock);
29269553 6588 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
ba8805b9
N		 6589 mddev->new_chunk_sectors =
6590 conf->chunk_sectors = conf->prev_chunk_sectors;
6591 mddev->new_layout = conf->algorithm = conf->prev_algo;
05616be5
N		 6592 rdev_for_each(rdev, mddev)
6593 rdev->new_data_offset = rdev->data_offset;
6594 smp_wmb();
ba8805b9 6595 conf->generation --;
fef9c61f 6596 conf->reshape_progress = MaxSector;
1e3fa9bd 6597 mddev->reshape_position = MaxSector;
ba8805b9 6598 write_seqcount_end(&conf->gen_lock);
29269553
N		 6599 spin_unlock_irq(&conf->device_lock);
6600 return -EAGAIN;
6601 }
c8f517c4 6602 conf->reshape_checkpoint = jiffies;
29269553
N		 6603 md_wakeup_thread(mddev->sync_thread);
6604 md_new_event(mddev);
6605 return 0;
6606}
29269553 6607
ec32a2bd
N		 6608/* This is called from the reshape thread and should make any
6609 * changes needed in 'conf'
6610 */
d1688a6d 6611static void end_reshape(struct r5conf *conf)
29269553 6612{
29269553 6613
f6705578 6614 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
05616be5 6615 struct md_rdev *rdev;
f6705578 6616
f6705578 6617 spin_lock_irq(&conf->device_lock);
cea9c228 6618 conf->previous_raid_disks = conf->raid_disks;
05616be5
N		 6619 rdev_for_each(rdev, conf->mddev)
6620 rdev->data_offset = rdev->new_data_offset;
6621 smp_wmb();
fef9c61f 6622 conf->reshape_progress = MaxSector;
f6705578 6623 spin_unlock_irq(&conf->device_lock);
b0f9ec04 6624 wake_up(&conf->wait_for_overlap);
16a53ecc
N		 6625
6626 /* read-ahead size must cover two whole stripes, which is
6627 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6628 */
4a5add49 6629 if (conf->mddev->queue) {
cea9c228 6630 int data_disks = conf->raid_disks - conf->max_degraded;
09c9e5fa 6631 int stripe = data_disks * ((conf->chunk_sectors << 9)
cea9c228 6632 / PAGE_SIZE);
16a53ecc
N		 6633 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6634 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6635 }
29269553 6636 }
29269553
N		 6637}
6638
ec32a2bd
N		 6639/* This is called from the raid5d thread with mddev_lock held.
6640 * It makes config changes to the device.
6641 */
fd01b88c 6642static void raid5_finish_reshape(struct mddev *mddev)
cea9c228 6643{
d1688a6d 6644 struct r5conf *conf = mddev->private;
cea9c228
N		 6645
6646 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6647
ec32a2bd
N		 6648 if (mddev->delta_disks > 0) {
6649 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6650 set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e 6651 revalidate_disk(mddev->gendisk);
ec32a2bd
N		 6652 } else {
6653 int d;
908f4fbd
N		 6654 spin_lock_irq(&conf->device_lock);
6655 mddev->degraded = calc_degraded(conf);
6656 spin_unlock_irq(&conf->device_lock);
ec32a2bd
N		 6657 for (d = conf->raid_disks ;
6658 d < conf->raid_disks - mddev->delta_disks;
1a67dde0 6659 d++) {
3cb03002 6660 struct md_rdev *rdev = conf->disks[d].rdev;
da7613b8
N		 6661 if (rdev)
6662 clear_bit(In_sync, &rdev->flags);
6663 rdev = conf->disks[d].replacement;
6664 if (rdev)
6665 clear_bit(In_sync, &rdev->flags);
1a67dde0 6666 }
cea9c228 6667 }
88ce4930 6668 mddev->layout = conf->algorithm;
09c9e5fa 6669 mddev->chunk_sectors = conf->chunk_sectors;
ec32a2bd
N		 6670 mddev->reshape_position = MaxSector;
6671 mddev->delta_disks = 0;
2c810cdd 6672 mddev->reshape_backwards = 0;
cea9c228
N		 6673 }
6674}
6675
fd01b88c 6676static void raid5_quiesce(struct mddev *mddev, int state)
72626685 6677{
d1688a6d 6678 struct r5conf *conf = mddev->private;
72626685
N		 6679
6680 switch(state) {
e464eafd
N		 6681 case 2: /* resume for a suspend */
6682 wake_up(&conf->wait_for_overlap);
6683 break;
6684
72626685 6685 case 1: /* stop all writes */
566c09c5 6686 lock_all_device_hash_locks_irq(conf);
64bd660b
N		 6687 /* '2' tells resync/reshape to pause so that all
6688 * active stripes can drain
6689 */
6690 conf->quiesce = 2;
566c09c5 6691 wait_event_cmd(conf->wait_for_stripe,
46031f9a
RBJ		 6692 atomic_read(&conf->active_stripes) == 0 &&
6693 atomic_read(&conf->active_aligned_reads) == 0,
566c09c5
SL		 6694 unlock_all_device_hash_locks_irq(conf),
6695 lock_all_device_hash_locks_irq(conf));
64bd660b 6696 conf->quiesce = 1;
566c09c5 6697 unlock_all_device_hash_locks_irq(conf);
64bd660b
N		 6698 /* allow reshape to continue */
6699 wake_up(&conf->wait_for_overlap);
72626685
N		 6700 break;
6701
6702 case 0: /* re-enable writes */
566c09c5 6703 lock_all_device_hash_locks_irq(conf);
72626685
N		 6704 conf->quiesce = 0;
6705 wake_up(&conf->wait_for_stripe);
e464eafd 6706 wake_up(&conf->wait_for_overlap);
566c09c5 6707 unlock_all_device_hash_locks_irq(conf);
72626685
N		 6708 break;
6709 }
72626685 6710}
b15c2e57 6711
d562b0c4 6712
fd01b88c 6713static void *raid45_takeover_raid0(struct mddev *mddev, int level)
54071b38 6714{
e373ab10 6715 struct r0conf *raid0_conf = mddev->private;
d76c8420 6716 sector_t sectors;
54071b38 6717
f1b29bca 6718 /* for raid0 takeover only one zone is supported */
e373ab10 6719 if (raid0_conf->nr_strip_zones > 1) {
0c55e022
N		 6720 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6721 mdname(mddev));
f1b29bca
DW		 6722 return ERR_PTR(-EINVAL);
6723 }
6724
e373ab10
N		 6725 sectors = raid0_conf->strip_zone[0].zone_end;
6726 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
3b71bd93 6727 mddev->dev_sectors = sectors;
f1b29bca 6728 mddev->new_level = level;
54071b38
TM		 6729 mddev->new_layout = ALGORITHM_PARITY_N;
6730 mddev->new_chunk_sectors = mddev->chunk_sectors;
6731 mddev->raid_disks += 1;
6732 mddev->delta_disks = 1;
6733 /* make sure it will be not marked as dirty */
6734 mddev->recovery_cp = MaxSector;
6735
6736 return setup_conf(mddev);
6737}
6738
6739
fd01b88c 6740static void *raid5_takeover_raid1(struct mddev *mddev)
d562b0c4
N		 6741{
6742 int chunksect;
6743
6744 if (mddev->raid_disks != 2 ||
6745 mddev->degraded > 1)
6746 return ERR_PTR(-EINVAL);
6747
6748 /* Should check if there are write-behind devices? */
6749
6750 chunksect = 64*2; /* 64K by default */
6751
6752 /* The array must be an exact multiple of chunksize */
6753 while (chunksect && (mddev->array_sectors & (chunksect-1)))
6754 chunksect >>= 1;
6755
6756 if ((chunksect<<9) < STRIPE_SIZE)
6757 /* array size does not allow a suitable chunk size */
6758 return ERR_PTR(-EINVAL);
6759
6760 mddev->new_level = 5;
6761 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
664e7c41 6762 mddev->new_chunk_sectors = chunksect;
d562b0c4
N		 6763
6764 return setup_conf(mddev);
6765}
6766
fd01b88c 6767static void *raid5_takeover_raid6(struct mddev *mddev)
fc9739c6
N		 6768{
6769 int new_layout;
6770
6771 switch (mddev->layout) {
6772 case ALGORITHM_LEFT_ASYMMETRIC_6:
6773 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
6774 break;
6775 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6776 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
6777 break;
6778 case ALGORITHM_LEFT_SYMMETRIC_6:
6779 new_layout = ALGORITHM_LEFT_SYMMETRIC;
6780 break;
6781 case ALGORITHM_RIGHT_SYMMETRIC_6:
6782 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
6783 break;
6784 case ALGORITHM_PARITY_0_6:
6785 new_layout = ALGORITHM_PARITY_0;
6786 break;
6787 case ALGORITHM_PARITY_N:
6788 new_layout = ALGORITHM_PARITY_N;
6789 break;
6790 default:
6791 return ERR_PTR(-EINVAL);
6792 }
6793 mddev->new_level = 5;
6794 mddev->new_layout = new_layout;
6795 mddev->delta_disks = -1;
6796 mddev->raid_disks -= 1;
6797 return setup_conf(mddev);
6798}
6799
d562b0c4 6800
fd01b88c 6801static int raid5_check_reshape(struct mddev *mddev)
b3546035 6802{
88ce4930
N		 6803 /* For a 2-drive array, the layout and chunk size can be changed
6804 * immediately as not restriping is needed.
6805 * For larger arrays we record the new value - after validation
6806 * to be used by a reshape pass.
b3546035 6807 */
d1688a6d 6808 struct r5conf *conf = mddev->private;
597a711b 6809 int new_chunk = mddev->new_chunk_sectors;
b3546035 6810
597a711b 6811 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
b3546035
N		 6812 return -EINVAL;
6813 if (new_chunk > 0) {
0ba459d2 6814 if (!is_power_of_2(new_chunk))
b3546035 6815 return -EINVAL;
597a711b 6816 if (new_chunk < (PAGE_SIZE>>9))
b3546035 6817 return -EINVAL;
597a711b 6818 if (mddev->array_sectors & (new_chunk-1))
b3546035
N		 6819 /* not factor of array size */
6820 return -EINVAL;
6821 }
6822
6823 /* They look valid */
6824
88ce4930 6825 if (mddev->raid_disks == 2) {
597a711b
N		 6826 /* can make the change immediately */
6827 if (mddev->new_layout >= 0) {
6828 conf->algorithm = mddev->new_layout;
6829 mddev->layout = mddev->new_layout;
88ce4930
N		 6830 }
6831 if (new_chunk > 0) {
597a711b
N		 6832 conf->chunk_sectors = new_chunk ;
6833 mddev->chunk_sectors = new_chunk;
88ce4930
N		 6834 }
6835 set_bit(MD_CHANGE_DEVS, &mddev->flags);
6836 md_wakeup_thread(mddev->thread);
b3546035 6837 }
50ac168a 6838 return check_reshape(mddev);
88ce4930
N		 6839}
6840
fd01b88c 6841static int raid6_check_reshape(struct mddev *mddev)
88ce4930 6842{
597a711b 6843 int new_chunk = mddev->new_chunk_sectors;
50ac168a 6844
597a711b 6845 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
88ce4930 6846 return -EINVAL;
b3546035 6847 if (new_chunk > 0) {
0ba459d2 6848 if (!is_power_of_2(new_chunk))
88ce4930 6849 return -EINVAL;
597a711b 6850 if (new_chunk < (PAGE_SIZE >> 9))
88ce4930 6851 return -EINVAL;
597a711b 6852 if (mddev->array_sectors & (new_chunk-1))
88ce4930
N		 6853 /* not factor of array size */
6854 return -EINVAL;
b3546035 6855 }
88ce4930
N		 6856
6857 /* They look valid */
50ac168a 6858 return check_reshape(mddev);
b3546035
N		 6859}
6860
fd01b88c 6861static void *raid5_takeover(struct mddev *mddev)
d562b0c4
N		 6862{
6863 /* raid5 can take over:
f1b29bca 6864 * raid0 - if there is only one strip zone - make it a raid4 layout
d562b0c4
N		 6865 * raid1 - if there are two drives. We need to know the chunk size
6866 * raid4 - trivial - just use a raid4 layout.
6867 * raid6 - Providing it is a *_6 layout
d562b0c4 6868 */
f1b29bca
DW		 6869 if (mddev->level == 0)
6870 return raid45_takeover_raid0(mddev, 5);
d562b0c4
N		 6871 if (mddev->level == 1)
6872 return raid5_takeover_raid1(mddev);
e9d4758f
N		 6873 if (mddev->level == 4) {
6874 mddev->new_layout = ALGORITHM_PARITY_N;
6875 mddev->new_level = 5;
6876 return setup_conf(mddev);
6877 }
fc9739c6
N		 6878 if (mddev->level == 6)
6879 return raid5_takeover_raid6(mddev);
d562b0c4
N		 6880
6881 return ERR_PTR(-EINVAL);
6882}
6883
fd01b88c 6884static void *raid4_takeover(struct mddev *mddev)
a78d38a1 6885{
f1b29bca
DW		 6886 /* raid4 can take over:
6887 * raid0 - if there is only one strip zone
6888 * raid5 - if layout is right
a78d38a1 6889 */
f1b29bca
DW		 6890 if (mddev->level == 0)
6891 return raid45_takeover_raid0(mddev, 4);
a78d38a1
N		 6892 if (mddev->level == 5 &&
6893 mddev->layout == ALGORITHM_PARITY_N) {
6894 mddev->new_layout = 0;
6895 mddev->new_level = 4;
6896 return setup_conf(mddev);
6897 }
6898 return ERR_PTR(-EINVAL);
6899}
d562b0c4 6900
84fc4b56 6901static struct md_personality raid5_personality;
245f46c2 6902
fd01b88c 6903static void *raid6_takeover(struct mddev *mddev)
245f46c2
N		 6904{
6905 /* Currently can only take over a raid5. We map the
6906 * personality to an equivalent raid6 personality
6907 * with the Q block at the end.
6908 */
6909 int new_layout;
6910
6911 if (mddev->pers != &raid5_personality)
6912 return ERR_PTR(-EINVAL);
6913 if (mddev->degraded > 1)
6914 return ERR_PTR(-EINVAL);
6915 if (mddev->raid_disks > 253)
6916 return ERR_PTR(-EINVAL);
6917 if (mddev->raid_disks < 3)
6918 return ERR_PTR(-EINVAL);
6919
6920 switch (mddev->layout) {
6921 case ALGORITHM_LEFT_ASYMMETRIC:
6922 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
6923 break;
6924 case ALGORITHM_RIGHT_ASYMMETRIC:
6925 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
6926 break;
6927 case ALGORITHM_LEFT_SYMMETRIC:
6928 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
6929 break;
6930 case ALGORITHM_RIGHT_SYMMETRIC:
6931 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
6932 break;
6933 case ALGORITHM_PARITY_0:
6934 new_layout = ALGORITHM_PARITY_0_6;
6935 break;
6936 case ALGORITHM_PARITY_N:
6937 new_layout = ALGORITHM_PARITY_N;
6938 break;
6939 default:
6940 return ERR_PTR(-EINVAL);
6941 }
6942 mddev->new_level = 6;
6943 mddev->new_layout = new_layout;
6944 mddev->delta_disks = 1;
6945 mddev->raid_disks += 1;
6946 return setup_conf(mddev);
6947}
6948
6949
84fc4b56 6950static struct md_personality raid6_personality =
16a53ecc
N		 6951{
6952 .name = "raid6",
6953 .level = 6,
6954 .owner = THIS_MODULE,
6955 .make_request = make_request,
6956 .run = run,
6957 .stop = stop,
6958 .status = status,
6959 .error_handler = error,
6960 .hot_add_disk = raid5_add_disk,
6961 .hot_remove_disk= raid5_remove_disk,
6962 .spare_active = raid5_spare_active,
6963 .sync_request = sync_request,
6964 .resize = raid5_resize,
80c3a6ce 6965 .size = raid5_size,
50ac168a 6966 .check_reshape = raid6_check_reshape,
f416885e 6967 .start_reshape = raid5_start_reshape,
cea9c228 6968 .finish_reshape = raid5_finish_reshape,
16a53ecc 6969 .quiesce = raid5_quiesce,
245f46c2 6970 .takeover = raid6_takeover,
16a53ecc 6971};
84fc4b56 6972static struct md_personality raid5_personality =
1da177e4
LT		 6973{
6974 .name = "raid5",
2604b703 6975 .level = 5,
1da177e4
LT		 6976 .owner = THIS_MODULE,
6977 .make_request = make_request,
6978 .run = run,
6979 .stop = stop,
6980 .status = status,
6981 .error_handler = error,
6982 .hot_add_disk = raid5_add_disk,
6983 .hot_remove_disk= raid5_remove_disk,
6984 .spare_active = raid5_spare_active,
6985 .sync_request = sync_request,
6986 .resize = raid5_resize,
80c3a6ce 6987 .size = raid5_size,
63c70c4f
N		 6988 .check_reshape = raid5_check_reshape,
6989 .start_reshape = raid5_start_reshape,
cea9c228 6990 .finish_reshape = raid5_finish_reshape,
72626685 6991 .quiesce = raid5_quiesce,
d562b0c4 6992 .takeover = raid5_takeover,
1da177e4
LT		 6993};
6994
84fc4b56 6995static struct md_personality raid4_personality =
1da177e4 6996{
2604b703
N		 6997 .name = "raid4",
6998 .level = 4,
6999 .owner = THIS_MODULE,
7000 .make_request = make_request,
7001 .run = run,
7002 .stop = stop,
7003 .status = status,
7004 .error_handler = error,
7005 .hot_add_disk = raid5_add_disk,
7006 .hot_remove_disk= raid5_remove_disk,
7007 .spare_active = raid5_spare_active,
7008 .sync_request = sync_request,
7009 .resize = raid5_resize,
80c3a6ce 7010 .size = raid5_size,
3d37890b
N		 7011 .check_reshape = raid5_check_reshape,
7012 .start_reshape = raid5_start_reshape,
cea9c228 7013 .finish_reshape = raid5_finish_reshape,
2604b703 7014 .quiesce = raid5_quiesce,
a78d38a1 7015 .takeover = raid4_takeover,
2604b703
N		 7016};
7017
7018static int __init raid5_init(void)
7019{
851c30c9
SL		 7020 raid5_wq = alloc_workqueue("raid5wq",
7021 WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
7022 if (!raid5_wq)
7023 return -ENOMEM;
16a53ecc 7024 register_md_personality(&raid6_personality);
2604b703
N		 7025 register_md_personality(&raid5_personality);
7026 register_md_personality(&raid4_personality);
7027 return 0;
1da177e4
LT		 7028}
7029
2604b703 7030static void raid5_exit(void)
1da177e4 7031{
16a53ecc 7032 unregister_md_personality(&raid6_personality);
2604b703
N		 7033 unregister_md_personality(&raid5_personality);
7034 unregister_md_personality(&raid4_personality);
851c30c9 7035 destroy_workqueue(raid5_wq);
1da177e4
LT		 7036}
7037
7038module_init(raid5_init);
7039module_exit(raid5_exit);
7040MODULE_LICENSE("GPL");
0efb9e61 7041MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
1da177e4 7042MODULE_ALIAS("md-personality-4"); /* RAID5 */
d9d166c2
N		 7043MODULE_ALIAS("md-raid5");
7044MODULE_ALIAS("md-raid4");
2604b703
N		 7045MODULE_ALIAS("md-level-5");
7046MODULE_ALIAS("md-level-4");
16a53ecc
N		 7047MODULE_ALIAS("md-personality-8"); /* RAID6 */
7048MODULE_ALIAS("md-raid6");
7049MODULE_ALIAS("md-level-6");
7050
7051/* This used to be two separate modules, they were: */
7052MODULE_ALIAS("raid5");
7053MODULE_ALIAS("raid6");
Linux 6.x block layer and io_uring tree(s)