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1da177e4 LT |
1 | /* |
2 | * raid6main.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 | |
5 | * Copyright (C) 2002, 2003 H. Peter Anvin | |
6 | * | |
7 | * RAID-6 management functions. This code is derived from raid5.c. | |
8 | * Last merge from raid5.c bkcvs version 1.79 (kernel 2.6.1). | |
9 | * | |
10 | * Thanks to Penguin Computing for making the RAID-6 development possible | |
11 | * by donating a test server! | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2, or (at your option) | |
16 | * any later version. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * (for example /usr/src/linux/COPYING); if not, write to the Free | |
20 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
23 | ||
24 | #include <linux/config.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/highmem.h> | |
28 | #include <linux/bitops.h> | |
29 | #include <asm/atomic.h> | |
30 | #include "raid6.h" | |
31 | ||
934ce7c8 N |
32 | #include <linux/raid/bitmap.h> |
33 | ||
1da177e4 LT |
34 | /* |
35 | * Stripe cache | |
36 | */ | |
37 | ||
38 | #define NR_STRIPES 256 | |
39 | #define STRIPE_SIZE PAGE_SIZE | |
40 | #define STRIPE_SHIFT (PAGE_SHIFT - 9) | |
41 | #define STRIPE_SECTORS (STRIPE_SIZE>>9) | |
42 | #define IO_THRESHOLD 1 | |
43 | #define HASH_PAGES 1 | |
44 | #define HASH_PAGES_ORDER 0 | |
45 | #define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *)) | |
46 | #define HASH_MASK (NR_HASH - 1) | |
47 | ||
48 | #define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]) | |
49 | ||
50 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector | |
51 | * order without overlap. There may be several bio's per stripe+device, and | |
52 | * a bio could span several devices. | |
53 | * When walking this list for a particular stripe+device, we must never proceed | |
54 | * beyond a bio that extends past this device, as the next bio might no longer | |
55 | * be valid. | |
56 | * This macro is used to determine the 'next' bio in the list, given the sector | |
57 | * of the current stripe+device | |
58 | */ | |
59 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) | |
60 | /* | |
61 | * The following can be used to debug the driver | |
62 | */ | |
63 | #define RAID6_DEBUG 0 /* Extremely verbose printk */ | |
64 | #define RAID6_PARANOIA 1 /* Check spinlocks */ | |
65 | #define RAID6_DUMPSTATE 0 /* Include stripe cache state in /proc/mdstat */ | |
66 | #if RAID6_PARANOIA && defined(CONFIG_SMP) | |
67 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) | |
68 | #else | |
69 | # define CHECK_DEVLOCK() | |
70 | #endif | |
71 | ||
72 | #define PRINTK(x...) ((void)(RAID6_DEBUG && printk(KERN_DEBUG x))) | |
73 | #if RAID6_DEBUG | |
74 | #undef inline | |
75 | #undef __inline__ | |
76 | #define inline | |
77 | #define __inline__ | |
78 | #endif | |
79 | ||
80 | #if !RAID6_USE_EMPTY_ZERO_PAGE | |
81 | /* In .bss so it's zeroed */ | |
82 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); | |
83 | #endif | |
84 | ||
85 | static inline int raid6_next_disk(int disk, int raid_disks) | |
86 | { | |
87 | disk++; | |
88 | return (disk < raid_disks) ? disk : 0; | |
89 | } | |
90 | ||
91 | static void print_raid6_conf (raid6_conf_t *conf); | |
92 | ||
93 | static inline void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) | |
94 | { | |
95 | if (atomic_dec_and_test(&sh->count)) { | |
96 | if (!list_empty(&sh->lru)) | |
97 | BUG(); | |
98 | if (atomic_read(&conf->active_stripes)==0) | |
99 | BUG(); | |
100 | if (test_bit(STRIPE_HANDLE, &sh->state)) { | |
101 | if (test_bit(STRIPE_DELAYED, &sh->state)) | |
102 | list_add_tail(&sh->lru, &conf->delayed_list); | |
934ce7c8 N |
103 | else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
104 | conf->seq_write == sh->bm_seq) | |
105 | list_add_tail(&sh->lru, &conf->bitmap_list); | |
106 | else { | |
107 | clear_bit(STRIPE_BIT_DELAY, &sh->state); | |
1da177e4 | 108 | list_add_tail(&sh->lru, &conf->handle_list); |
934ce7c8 | 109 | } |
1da177e4 LT |
110 | md_wakeup_thread(conf->mddev->thread); |
111 | } else { | |
112 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
113 | atomic_dec(&conf->preread_active_stripes); | |
114 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
115 | md_wakeup_thread(conf->mddev->thread); | |
116 | } | |
117 | list_add_tail(&sh->lru, &conf->inactive_list); | |
118 | atomic_dec(&conf->active_stripes); | |
119 | if (!conf->inactive_blocked || | |
120 | atomic_read(&conf->active_stripes) < (NR_STRIPES*3/4)) | |
121 | wake_up(&conf->wait_for_stripe); | |
122 | } | |
123 | } | |
124 | } | |
125 | static void release_stripe(struct stripe_head *sh) | |
126 | { | |
127 | raid6_conf_t *conf = sh->raid_conf; | |
128 | unsigned long flags; | |
129 | ||
130 | spin_lock_irqsave(&conf->device_lock, flags); | |
131 | __release_stripe(conf, sh); | |
132 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
133 | } | |
134 | ||
135 | static void remove_hash(struct stripe_head *sh) | |
136 | { | |
137 | PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
138 | ||
139 | if (sh->hash_pprev) { | |
140 | if (sh->hash_next) | |
141 | sh->hash_next->hash_pprev = sh->hash_pprev; | |
142 | *sh->hash_pprev = sh->hash_next; | |
143 | sh->hash_pprev = NULL; | |
144 | } | |
145 | } | |
146 | ||
147 | static __inline__ void insert_hash(raid6_conf_t *conf, struct stripe_head *sh) | |
148 | { | |
149 | struct stripe_head **shp = &stripe_hash(conf, sh->sector); | |
150 | ||
151 | PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
152 | ||
153 | CHECK_DEVLOCK(); | |
154 | if ((sh->hash_next = *shp) != NULL) | |
155 | (*shp)->hash_pprev = &sh->hash_next; | |
156 | *shp = sh; | |
157 | sh->hash_pprev = shp; | |
158 | } | |
159 | ||
160 | ||
161 | /* find an idle stripe, make sure it is unhashed, and return it. */ | |
162 | static struct stripe_head *get_free_stripe(raid6_conf_t *conf) | |
163 | { | |
164 | struct stripe_head *sh = NULL; | |
165 | struct list_head *first; | |
166 | ||
167 | CHECK_DEVLOCK(); | |
168 | if (list_empty(&conf->inactive_list)) | |
169 | goto out; | |
170 | first = conf->inactive_list.next; | |
171 | sh = list_entry(first, struct stripe_head, lru); | |
172 | list_del_init(first); | |
173 | remove_hash(sh); | |
174 | atomic_inc(&conf->active_stripes); | |
175 | out: | |
176 | return sh; | |
177 | } | |
178 | ||
179 | static void shrink_buffers(struct stripe_head *sh, int num) | |
180 | { | |
181 | struct page *p; | |
182 | int i; | |
183 | ||
184 | for (i=0; i<num ; i++) { | |
185 | p = sh->dev[i].page; | |
186 | if (!p) | |
187 | continue; | |
188 | sh->dev[i].page = NULL; | |
189 | page_cache_release(p); | |
190 | } | |
191 | } | |
192 | ||
193 | static int grow_buffers(struct stripe_head *sh, int num) | |
194 | { | |
195 | int i; | |
196 | ||
197 | for (i=0; i<num; i++) { | |
198 | struct page *page; | |
199 | ||
200 | if (!(page = alloc_page(GFP_KERNEL))) { | |
201 | return 1; | |
202 | } | |
203 | sh->dev[i].page = page; | |
204 | } | |
205 | return 0; | |
206 | } | |
207 | ||
208 | static void raid6_build_block (struct stripe_head *sh, int i); | |
209 | ||
210 | static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) | |
211 | { | |
212 | raid6_conf_t *conf = sh->raid_conf; | |
213 | int disks = conf->raid_disks, i; | |
214 | ||
215 | if (atomic_read(&sh->count) != 0) | |
216 | BUG(); | |
217 | if (test_bit(STRIPE_HANDLE, &sh->state)) | |
218 | BUG(); | |
219 | ||
220 | CHECK_DEVLOCK(); | |
221 | PRINTK("init_stripe called, stripe %llu\n", | |
222 | (unsigned long long)sh->sector); | |
223 | ||
224 | remove_hash(sh); | |
225 | ||
226 | sh->sector = sector; | |
227 | sh->pd_idx = pd_idx; | |
228 | sh->state = 0; | |
229 | ||
230 | for (i=disks; i--; ) { | |
231 | struct r5dev *dev = &sh->dev[i]; | |
232 | ||
233 | if (dev->toread || dev->towrite || dev->written || | |
234 | test_bit(R5_LOCKED, &dev->flags)) { | |
235 | PRINTK("sector=%llx i=%d %p %p %p %d\n", | |
236 | (unsigned long long)sh->sector, i, dev->toread, | |
237 | dev->towrite, dev->written, | |
238 | test_bit(R5_LOCKED, &dev->flags)); | |
239 | BUG(); | |
240 | } | |
241 | dev->flags = 0; | |
242 | raid6_build_block(sh, i); | |
243 | } | |
244 | insert_hash(conf, sh); | |
245 | } | |
246 | ||
247 | static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector) | |
248 | { | |
249 | struct stripe_head *sh; | |
250 | ||
251 | CHECK_DEVLOCK(); | |
252 | PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); | |
253 | for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next) | |
254 | if (sh->sector == sector) | |
255 | return sh; | |
256 | PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); | |
257 | return NULL; | |
258 | } | |
259 | ||
260 | static void unplug_slaves(mddev_t *mddev); | |
261 | ||
262 | static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector, | |
263 | int pd_idx, int noblock) | |
264 | { | |
265 | struct stripe_head *sh; | |
266 | ||
267 | PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); | |
268 | ||
269 | spin_lock_irq(&conf->device_lock); | |
270 | ||
271 | do { | |
934ce7c8 N |
272 | wait_event_lock_irq(conf->wait_for_stripe, |
273 | conf->quiesce == 0, | |
274 | conf->device_lock, /* nothing */); | |
1da177e4 LT |
275 | sh = __find_stripe(conf, sector); |
276 | if (!sh) { | |
277 | if (!conf->inactive_blocked) | |
278 | sh = get_free_stripe(conf); | |
279 | if (noblock && sh == NULL) | |
280 | break; | |
281 | if (!sh) { | |
282 | conf->inactive_blocked = 1; | |
283 | wait_event_lock_irq(conf->wait_for_stripe, | |
284 | !list_empty(&conf->inactive_list) && | |
285 | (atomic_read(&conf->active_stripes) < (NR_STRIPES *3/4) | |
286 | || !conf->inactive_blocked), | |
287 | conf->device_lock, | |
288 | unplug_slaves(conf->mddev); | |
289 | ); | |
290 | conf->inactive_blocked = 0; | |
291 | } else | |
292 | init_stripe(sh, sector, pd_idx); | |
293 | } else { | |
294 | if (atomic_read(&sh->count)) { | |
295 | if (!list_empty(&sh->lru)) | |
296 | BUG(); | |
297 | } else { | |
298 | if (!test_bit(STRIPE_HANDLE, &sh->state)) | |
299 | atomic_inc(&conf->active_stripes); | |
300 | if (list_empty(&sh->lru)) | |
301 | BUG(); | |
302 | list_del_init(&sh->lru); | |
303 | } | |
304 | } | |
305 | } while (sh == NULL); | |
306 | ||
307 | if (sh) | |
308 | atomic_inc(&sh->count); | |
309 | ||
310 | spin_unlock_irq(&conf->device_lock); | |
311 | return sh; | |
312 | } | |
313 | ||
314 | static int grow_stripes(raid6_conf_t *conf, int num) | |
315 | { | |
316 | struct stripe_head *sh; | |
317 | kmem_cache_t *sc; | |
318 | int devs = conf->raid_disks; | |
319 | ||
320 | sprintf(conf->cache_name, "raid6/%s", mdname(conf->mddev)); | |
321 | ||
322 | sc = kmem_cache_create(conf->cache_name, | |
323 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), | |
324 | 0, 0, NULL, NULL); | |
325 | if (!sc) | |
326 | return 1; | |
327 | conf->slab_cache = sc; | |
328 | while (num--) { | |
329 | sh = kmem_cache_alloc(sc, GFP_KERNEL); | |
330 | if (!sh) | |
331 | return 1; | |
332 | memset(sh, 0, sizeof(*sh) + (devs-1)*sizeof(struct r5dev)); | |
333 | sh->raid_conf = conf; | |
334 | spin_lock_init(&sh->lock); | |
335 | ||
336 | if (grow_buffers(sh, conf->raid_disks)) { | |
337 | shrink_buffers(sh, conf->raid_disks); | |
338 | kmem_cache_free(sc, sh); | |
339 | return 1; | |
340 | } | |
341 | /* we just created an active stripe so... */ | |
342 | atomic_set(&sh->count, 1); | |
343 | atomic_inc(&conf->active_stripes); | |
344 | INIT_LIST_HEAD(&sh->lru); | |
345 | release_stripe(sh); | |
346 | } | |
347 | return 0; | |
348 | } | |
349 | ||
350 | static void shrink_stripes(raid6_conf_t *conf) | |
351 | { | |
352 | struct stripe_head *sh; | |
353 | ||
354 | while (1) { | |
355 | spin_lock_irq(&conf->device_lock); | |
356 | sh = get_free_stripe(conf); | |
357 | spin_unlock_irq(&conf->device_lock); | |
358 | if (!sh) | |
359 | break; | |
360 | if (atomic_read(&sh->count)) | |
361 | BUG(); | |
362 | shrink_buffers(sh, conf->raid_disks); | |
363 | kmem_cache_free(conf->slab_cache, sh); | |
364 | atomic_dec(&conf->active_stripes); | |
365 | } | |
366 | kmem_cache_destroy(conf->slab_cache); | |
367 | conf->slab_cache = NULL; | |
368 | } | |
369 | ||
d69762e9 N |
370 | static int raid6_end_read_request(struct bio * bi, unsigned int bytes_done, |
371 | int error) | |
1da177e4 LT |
372 | { |
373 | struct stripe_head *sh = bi->bi_private; | |
374 | raid6_conf_t *conf = sh->raid_conf; | |
375 | int disks = conf->raid_disks, i; | |
376 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
377 | ||
378 | if (bi->bi_size) | |
379 | return 1; | |
380 | ||
381 | for (i=0 ; i<disks; i++) | |
382 | if (bi == &sh->dev[i].req) | |
383 | break; | |
384 | ||
385 | PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", | |
386 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
387 | uptodate); | |
388 | if (i == disks) { | |
389 | BUG(); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | if (uptodate) { | |
394 | #if 0 | |
395 | struct bio *bio; | |
396 | unsigned long flags; | |
397 | spin_lock_irqsave(&conf->device_lock, flags); | |
398 | /* we can return a buffer if we bypassed the cache or | |
399 | * if the top buffer is not in highmem. If there are | |
400 | * multiple buffers, leave the extra work to | |
401 | * handle_stripe | |
402 | */ | |
403 | buffer = sh->bh_read[i]; | |
404 | if (buffer && | |
405 | (!PageHighMem(buffer->b_page) | |
406 | || buffer->b_page == bh->b_page ) | |
407 | ) { | |
408 | sh->bh_read[i] = buffer->b_reqnext; | |
409 | buffer->b_reqnext = NULL; | |
410 | } else | |
411 | buffer = NULL; | |
412 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
413 | if (sh->bh_page[i]==bh->b_page) | |
414 | set_buffer_uptodate(bh); | |
415 | if (buffer) { | |
416 | if (buffer->b_page != bh->b_page) | |
417 | memcpy(buffer->b_data, bh->b_data, bh->b_size); | |
418 | buffer->b_end_io(buffer, 1); | |
419 | } | |
420 | #else | |
421 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
422 | #endif | |
d69762e9 N |
423 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
424 | printk(KERN_INFO "raid6: read error corrected!!\n"); | |
425 | clear_bit(R5_ReadError, &sh->dev[i].flags); | |
426 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
427 | } | |
428 | if (atomic_read(&conf->disks[i].rdev->read_errors)) | |
429 | atomic_set(&conf->disks[i].rdev->read_errors, 0); | |
1da177e4 | 430 | } else { |
d69762e9 | 431 | int retry = 0; |
1da177e4 | 432 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
d69762e9 N |
433 | atomic_inc(&conf->disks[i].rdev->read_errors); |
434 | if (conf->mddev->degraded) | |
435 | printk(KERN_WARNING "raid6: read error not correctable.\n"); | |
436 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) | |
437 | /* Oh, no!!! */ | |
438 | printk(KERN_WARNING "raid6: read error NOT corrected!!\n"); | |
439 | else if (atomic_read(&conf->disks[i].rdev->read_errors) | |
440 | > conf->max_nr_stripes) | |
441 | printk(KERN_WARNING | |
442 | "raid6: Too many read errors, failing device.\n"); | |
443 | else | |
444 | retry = 1; | |
445 | if (retry) | |
446 | set_bit(R5_ReadError, &sh->dev[i].flags); | |
447 | else { | |
448 | clear_bit(R5_ReadError, &sh->dev[i].flags); | |
449 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
450 | md_error(conf->mddev, conf->disks[i].rdev); | |
451 | } | |
1da177e4 LT |
452 | } |
453 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
454 | #if 0 | |
455 | /* must restore b_page before unlocking buffer... */ | |
456 | if (sh->bh_page[i] != bh->b_page) { | |
457 | bh->b_page = sh->bh_page[i]; | |
458 | bh->b_data = page_address(bh->b_page); | |
459 | clear_buffer_uptodate(bh); | |
460 | } | |
461 | #endif | |
462 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
463 | set_bit(STRIPE_HANDLE, &sh->state); | |
464 | release_stripe(sh); | |
465 | return 0; | |
466 | } | |
467 | ||
468 | static int raid6_end_write_request (struct bio *bi, unsigned int bytes_done, | |
469 | int error) | |
470 | { | |
471 | struct stripe_head *sh = bi->bi_private; | |
472 | raid6_conf_t *conf = sh->raid_conf; | |
473 | int disks = conf->raid_disks, i; | |
474 | unsigned long flags; | |
475 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
476 | ||
477 | if (bi->bi_size) | |
478 | return 1; | |
479 | ||
480 | for (i=0 ; i<disks; i++) | |
481 | if (bi == &sh->dev[i].req) | |
482 | break; | |
483 | ||
484 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", | |
485 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
486 | uptodate); | |
487 | if (i == disks) { | |
488 | BUG(); | |
489 | return 0; | |
490 | } | |
491 | ||
492 | spin_lock_irqsave(&conf->device_lock, flags); | |
493 | if (!uptodate) | |
494 | md_error(conf->mddev, conf->disks[i].rdev); | |
495 | ||
496 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
497 | ||
498 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
499 | set_bit(STRIPE_HANDLE, &sh->state); | |
500 | __release_stripe(conf, sh); | |
501 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
502 | return 0; | |
503 | } | |
504 | ||
505 | ||
506 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | |
507 | ||
508 | static void raid6_build_block (struct stripe_head *sh, int i) | |
509 | { | |
510 | struct r5dev *dev = &sh->dev[i]; | |
511 | int pd_idx = sh->pd_idx; | |
512 | int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks); | |
513 | ||
514 | bio_init(&dev->req); | |
515 | dev->req.bi_io_vec = &dev->vec; | |
516 | dev->req.bi_vcnt++; | |
517 | dev->req.bi_max_vecs++; | |
518 | dev->vec.bv_page = dev->page; | |
519 | dev->vec.bv_len = STRIPE_SIZE; | |
520 | dev->vec.bv_offset = 0; | |
521 | ||
522 | dev->req.bi_sector = sh->sector; | |
523 | dev->req.bi_private = sh; | |
524 | ||
525 | dev->flags = 0; | |
526 | if (i != pd_idx && i != qd_idx) | |
527 | dev->sector = compute_blocknr(sh, i); | |
528 | } | |
529 | ||
530 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
531 | { | |
532 | char b[BDEVNAME_SIZE]; | |
533 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
534 | PRINTK("raid6: error called\n"); | |
535 | ||
b2d444d7 | 536 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 537 | mddev->sb_dirty = 1; |
b2d444d7 | 538 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
539 | conf->working_disks--; |
540 | mddev->degraded++; | |
541 | conf->failed_disks++; | |
b2d444d7 | 542 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
543 | /* |
544 | * if recovery was running, make sure it aborts. | |
545 | */ | |
546 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
547 | } | |
b2d444d7 | 548 | set_bit(Faulty, &rdev->flags); |
1da177e4 LT |
549 | printk (KERN_ALERT |
550 | "raid6: Disk failure on %s, disabling device." | |
551 | " Operation continuing on %d devices\n", | |
552 | bdevname(rdev->bdev,b), conf->working_disks); | |
553 | } | |
554 | } | |
555 | ||
556 | /* | |
557 | * Input: a 'big' sector number, | |
558 | * Output: index of the data and parity disk, and the sector # in them. | |
559 | */ | |
560 | static sector_t raid6_compute_sector(sector_t r_sector, unsigned int raid_disks, | |
561 | unsigned int data_disks, unsigned int * dd_idx, | |
562 | unsigned int * pd_idx, raid6_conf_t *conf) | |
563 | { | |
564 | long stripe; | |
565 | unsigned long chunk_number; | |
566 | unsigned int chunk_offset; | |
567 | sector_t new_sector; | |
568 | int sectors_per_chunk = conf->chunk_size >> 9; | |
569 | ||
570 | /* First compute the information on this sector */ | |
571 | ||
572 | /* | |
573 | * Compute the chunk number and the sector offset inside the chunk | |
574 | */ | |
575 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | |
576 | chunk_number = r_sector; | |
577 | if ( r_sector != chunk_number ) { | |
578 | printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n", | |
579 | (unsigned long long)r_sector, (unsigned long)chunk_number); | |
580 | BUG(); | |
581 | } | |
582 | ||
583 | /* | |
584 | * Compute the stripe number | |
585 | */ | |
586 | stripe = chunk_number / data_disks; | |
587 | ||
588 | /* | |
589 | * Compute the data disk and parity disk indexes inside the stripe | |
590 | */ | |
591 | *dd_idx = chunk_number % data_disks; | |
592 | ||
593 | /* | |
594 | * Select the parity disk based on the user selected algorithm. | |
595 | */ | |
596 | ||
597 | /**** FIX THIS ****/ | |
598 | switch (conf->algorithm) { | |
599 | case ALGORITHM_LEFT_ASYMMETRIC: | |
600 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
601 | if (*pd_idx == raid_disks-1) | |
602 | (*dd_idx)++; /* Q D D D P */ | |
603 | else if (*dd_idx >= *pd_idx) | |
604 | (*dd_idx) += 2; /* D D P Q D */ | |
605 | break; | |
606 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
607 | *pd_idx = stripe % raid_disks; | |
608 | if (*pd_idx == raid_disks-1) | |
609 | (*dd_idx)++; /* Q D D D P */ | |
610 | else if (*dd_idx >= *pd_idx) | |
611 | (*dd_idx) += 2; /* D D P Q D */ | |
612 | break; | |
613 | case ALGORITHM_LEFT_SYMMETRIC: | |
614 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
615 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
616 | break; | |
617 | case ALGORITHM_RIGHT_SYMMETRIC: | |
618 | *pd_idx = stripe % raid_disks; | |
619 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
620 | break; | |
621 | default: | |
622 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
623 | conf->algorithm); | |
624 | } | |
625 | ||
626 | PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n", | |
627 | chunk_number, *pd_idx, *dd_idx); | |
628 | ||
629 | /* | |
630 | * Finally, compute the new sector number | |
631 | */ | |
632 | new_sector = (sector_t) stripe * sectors_per_chunk + chunk_offset; | |
633 | return new_sector; | |
634 | } | |
635 | ||
636 | ||
637 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | |
638 | { | |
639 | raid6_conf_t *conf = sh->raid_conf; | |
640 | int raid_disks = conf->raid_disks, data_disks = raid_disks - 2; | |
641 | sector_t new_sector = sh->sector, check; | |
642 | int sectors_per_chunk = conf->chunk_size >> 9; | |
643 | sector_t stripe; | |
644 | int chunk_offset; | |
645 | int chunk_number, dummy1, dummy2, dd_idx = i; | |
646 | sector_t r_sector; | |
647 | int i0 = i; | |
648 | ||
649 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | |
650 | stripe = new_sector; | |
651 | if ( new_sector != stripe ) { | |
652 | printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n", | |
653 | (unsigned long long)new_sector, (unsigned long)stripe); | |
654 | BUG(); | |
655 | } | |
656 | ||
657 | switch (conf->algorithm) { | |
658 | case ALGORITHM_LEFT_ASYMMETRIC: | |
659 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
660 | if (sh->pd_idx == raid_disks-1) | |
661 | i--; /* Q D D D P */ | |
662 | else if (i > sh->pd_idx) | |
663 | i -= 2; /* D D P Q D */ | |
664 | break; | |
665 | case ALGORITHM_LEFT_SYMMETRIC: | |
666 | case ALGORITHM_RIGHT_SYMMETRIC: | |
667 | if (sh->pd_idx == raid_disks-1) | |
668 | i--; /* Q D D D P */ | |
669 | else { | |
670 | /* D D P Q D */ | |
671 | if (i < sh->pd_idx) | |
672 | i += raid_disks; | |
673 | i -= (sh->pd_idx + 2); | |
674 | } | |
675 | break; | |
676 | default: | |
677 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
678 | conf->algorithm); | |
679 | } | |
680 | ||
681 | PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i); | |
682 | ||
683 | chunk_number = stripe * data_disks + i; | |
684 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | |
685 | ||
686 | check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | |
687 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | |
688 | printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n"); | |
689 | return 0; | |
690 | } | |
691 | return r_sector; | |
692 | } | |
693 | ||
694 | ||
695 | ||
696 | /* | |
697 | * Copy data between a page in the stripe cache, and one or more bion | |
698 | * The page could align with the middle of the bio, or there could be | |
699 | * several bion, each with several bio_vecs, which cover part of the page | |
700 | * Multiple bion are linked together on bi_next. There may be extras | |
701 | * at the end of this list. We ignore them. | |
702 | */ | |
703 | static void copy_data(int frombio, struct bio *bio, | |
704 | struct page *page, | |
705 | sector_t sector) | |
706 | { | |
707 | char *pa = page_address(page); | |
708 | struct bio_vec *bvl; | |
709 | int i; | |
710 | int page_offset; | |
711 | ||
712 | if (bio->bi_sector >= sector) | |
713 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
714 | else | |
715 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
716 | bio_for_each_segment(bvl, bio, i) { | |
717 | int len = bio_iovec_idx(bio,i)->bv_len; | |
718 | int clen; | |
719 | int b_offset = 0; | |
720 | ||
721 | if (page_offset < 0) { | |
722 | b_offset = -page_offset; | |
723 | page_offset += b_offset; | |
724 | len -= b_offset; | |
725 | } | |
726 | ||
727 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
728 | clen = STRIPE_SIZE - page_offset; | |
729 | else clen = len; | |
730 | ||
731 | if (clen > 0) { | |
732 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | |
733 | if (frombio) | |
734 | memcpy(pa+page_offset, ba+b_offset, clen); | |
735 | else | |
736 | memcpy(ba+b_offset, pa+page_offset, clen); | |
737 | __bio_kunmap_atomic(ba, KM_USER0); | |
738 | } | |
739 | if (clen < len) /* hit end of page */ | |
740 | break; | |
741 | page_offset += len; | |
742 | } | |
743 | } | |
744 | ||
745 | #define check_xor() do { \ | |
746 | if (count == MAX_XOR_BLOCKS) { \ | |
747 | xor_block(count, STRIPE_SIZE, ptr); \ | |
748 | count = 1; \ | |
749 | } \ | |
750 | } while(0) | |
751 | ||
752 | /* Compute P and Q syndromes */ | |
753 | static void compute_parity(struct stripe_head *sh, int method) | |
754 | { | |
755 | raid6_conf_t *conf = sh->raid_conf; | |
756 | int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; | |
757 | struct bio *chosen; | |
758 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
759 | void *ptrs[disks]; | |
760 | ||
761 | qd_idx = raid6_next_disk(pd_idx, disks); | |
762 | d0_idx = raid6_next_disk(qd_idx, disks); | |
763 | ||
764 | PRINTK("compute_parity, stripe %llu, method %d\n", | |
765 | (unsigned long long)sh->sector, method); | |
766 | ||
767 | switch(method) { | |
768 | case READ_MODIFY_WRITE: | |
769 | BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ | |
770 | case RECONSTRUCT_WRITE: | |
771 | for (i= disks; i-- ;) | |
772 | if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { | |
773 | chosen = sh->dev[i].towrite; | |
774 | sh->dev[i].towrite = NULL; | |
775 | ||
776 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
777 | wake_up(&conf->wait_for_overlap); | |
778 | ||
779 | if (sh->dev[i].written) BUG(); | |
780 | sh->dev[i].written = chosen; | |
781 | } | |
782 | break; | |
783 | case CHECK_PARITY: | |
784 | BUG(); /* Not implemented yet */ | |
785 | } | |
786 | ||
787 | for (i = disks; i--;) | |
788 | if (sh->dev[i].written) { | |
789 | sector_t sector = sh->dev[i].sector; | |
790 | struct bio *wbi = sh->dev[i].written; | |
791 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | |
792 | copy_data(1, wbi, sh->dev[i].page, sector); | |
793 | wbi = r5_next_bio(wbi, sector); | |
794 | } | |
795 | ||
796 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
797 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
798 | } | |
799 | ||
800 | // switch(method) { | |
801 | // case RECONSTRUCT_WRITE: | |
802 | // case CHECK_PARITY: | |
803 | // case UPDATE_PARITY: | |
804 | /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ | |
805 | /* FIX: Is this ordering of drives even remotely optimal? */ | |
806 | count = 0; | |
807 | i = d0_idx; | |
808 | do { | |
809 | ptrs[count++] = page_address(sh->dev[i].page); | |
810 | if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
811 | printk("block %d/%d not uptodate on parity calc\n", i,count); | |
812 | i = raid6_next_disk(i, disks); | |
813 | } while ( i != d0_idx ); | |
814 | // break; | |
815 | // } | |
816 | ||
817 | raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); | |
818 | ||
819 | switch(method) { | |
820 | case RECONSTRUCT_WRITE: | |
821 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
822 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
823 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
824 | set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); | |
825 | break; | |
826 | case UPDATE_PARITY: | |
827 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
828 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
829 | break; | |
830 | } | |
831 | } | |
832 | ||
833 | /* Compute one missing block */ | |
ca65b73b | 834 | static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) |
1da177e4 LT |
835 | { |
836 | raid6_conf_t *conf = sh->raid_conf; | |
837 | int i, count, disks = conf->raid_disks; | |
838 | void *ptr[MAX_XOR_BLOCKS], *p; | |
839 | int pd_idx = sh->pd_idx; | |
840 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
841 | ||
842 | PRINTK("compute_block_1, stripe %llu, idx %d\n", | |
843 | (unsigned long long)sh->sector, dd_idx); | |
844 | ||
845 | if ( dd_idx == qd_idx ) { | |
846 | /* We're actually computing the Q drive */ | |
847 | compute_parity(sh, UPDATE_PARITY); | |
848 | } else { | |
849 | ptr[0] = page_address(sh->dev[dd_idx].page); | |
ca65b73b | 850 | if (!nozero) memset(ptr[0], 0, STRIPE_SIZE); |
1da177e4 LT |
851 | count = 1; |
852 | for (i = disks ; i--; ) { | |
853 | if (i == dd_idx || i == qd_idx) | |
854 | continue; | |
855 | p = page_address(sh->dev[i].page); | |
856 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
857 | ptr[count++] = p; | |
858 | else | |
859 | printk("compute_block() %d, stripe %llu, %d" | |
860 | " not present\n", dd_idx, | |
861 | (unsigned long long)sh->sector, i); | |
862 | ||
863 | check_xor(); | |
864 | } | |
865 | if (count != 1) | |
866 | xor_block(count, STRIPE_SIZE, ptr); | |
ca65b73b N |
867 | if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); |
868 | else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
1da177e4 LT |
869 | } |
870 | } | |
871 | ||
872 | /* Compute two missing blocks */ | |
873 | static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) | |
874 | { | |
875 | raid6_conf_t *conf = sh->raid_conf; | |
876 | int i, count, disks = conf->raid_disks; | |
877 | int pd_idx = sh->pd_idx; | |
878 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
879 | int d0_idx = raid6_next_disk(qd_idx, disks); | |
880 | int faila, failb; | |
881 | ||
882 | /* faila and failb are disk numbers relative to d0_idx */ | |
883 | /* pd_idx become disks-2 and qd_idx become disks-1 */ | |
884 | faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; | |
885 | failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; | |
886 | ||
887 | BUG_ON(faila == failb); | |
888 | if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } | |
889 | ||
890 | PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", | |
891 | (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); | |
892 | ||
893 | if ( failb == disks-1 ) { | |
894 | /* Q disk is one of the missing disks */ | |
895 | if ( faila == disks-2 ) { | |
896 | /* Missing P+Q, just recompute */ | |
897 | compute_parity(sh, UPDATE_PARITY); | |
898 | return; | |
899 | } else { | |
900 | /* We're missing D+Q; recompute D from P */ | |
ca65b73b | 901 | compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); |
1da177e4 LT |
902 | compute_parity(sh, UPDATE_PARITY); /* Is this necessary? */ |
903 | return; | |
904 | } | |
905 | } | |
906 | ||
907 | /* We're missing D+P or D+D; build pointer table */ | |
908 | { | |
909 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
910 | void *ptrs[disks]; | |
911 | ||
912 | count = 0; | |
913 | i = d0_idx; | |
914 | do { | |
915 | ptrs[count++] = page_address(sh->dev[i].page); | |
916 | i = raid6_next_disk(i, disks); | |
917 | if (i != dd_idx1 && i != dd_idx2 && | |
918 | !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
919 | printk("compute_2 with missing block %d/%d\n", count, i); | |
920 | } while ( i != d0_idx ); | |
921 | ||
922 | if ( failb == disks-2 ) { | |
923 | /* We're missing D+P. */ | |
924 | raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); | |
925 | } else { | |
926 | /* We're missing D+D. */ | |
927 | raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); | |
928 | } | |
929 | ||
930 | /* Both the above update both missing blocks */ | |
931 | set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); | |
932 | set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); | |
933 | } | |
934 | } | |
935 | ||
936 | ||
937 | /* | |
938 | * Each stripe/dev can have one or more bion attached. | |
939 | * toread/towrite point to the first in a chain. | |
940 | * The bi_next chain must be in order. | |
941 | */ | |
942 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | |
943 | { | |
944 | struct bio **bip; | |
945 | raid6_conf_t *conf = sh->raid_conf; | |
934ce7c8 | 946 | int firstwrite=0; |
1da177e4 LT |
947 | |
948 | PRINTK("adding bh b#%llu to stripe s#%llu\n", | |
949 | (unsigned long long)bi->bi_sector, | |
950 | (unsigned long long)sh->sector); | |
951 | ||
952 | ||
953 | spin_lock(&sh->lock); | |
954 | spin_lock_irq(&conf->device_lock); | |
934ce7c8 | 955 | if (forwrite) { |
1da177e4 | 956 | bip = &sh->dev[dd_idx].towrite; |
934ce7c8 N |
957 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
958 | firstwrite = 1; | |
959 | } else | |
1da177e4 LT |
960 | bip = &sh->dev[dd_idx].toread; |
961 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | |
962 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | |
963 | goto overlap; | |
964 | bip = &(*bip)->bi_next; | |
965 | } | |
966 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | |
967 | goto overlap; | |
968 | ||
969 | if (*bip && bi->bi_next && (*bip) != bi->bi_next) | |
970 | BUG(); | |
971 | if (*bip) | |
972 | bi->bi_next = *bip; | |
973 | *bip = bi; | |
974 | bi->bi_phys_segments ++; | |
975 | spin_unlock_irq(&conf->device_lock); | |
976 | spin_unlock(&sh->lock); | |
977 | ||
978 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", | |
979 | (unsigned long long)bi->bi_sector, | |
980 | (unsigned long long)sh->sector, dd_idx); | |
981 | ||
934ce7c8 N |
982 | if (conf->mddev->bitmap && firstwrite) { |
983 | sh->bm_seq = conf->seq_write; | |
984 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | |
985 | STRIPE_SECTORS, 0); | |
986 | set_bit(STRIPE_BIT_DELAY, &sh->state); | |
987 | } | |
988 | ||
1da177e4 LT |
989 | if (forwrite) { |
990 | /* check if page is covered */ | |
991 | sector_t sector = sh->dev[dd_idx].sector; | |
992 | for (bi=sh->dev[dd_idx].towrite; | |
993 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | |
994 | bi && bi->bi_sector <= sector; | |
995 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | |
996 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | |
997 | sector = bi->bi_sector + (bi->bi_size>>9); | |
998 | } | |
999 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | |
1000 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | |
1001 | } | |
1002 | return 1; | |
1003 | ||
1004 | overlap: | |
1005 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | |
1006 | spin_unlock_irq(&conf->device_lock); | |
1007 | spin_unlock(&sh->lock); | |
1008 | return 0; | |
1009 | } | |
1010 | ||
1011 | ||
ca65b73b N |
1012 | static int page_is_zero(struct page *p) |
1013 | { | |
1014 | char *a = page_address(p); | |
1015 | return ((*(u32*)a) == 0 && | |
1016 | memcmp(a, a+4, STRIPE_SIZE-4)==0); | |
1017 | } | |
1da177e4 LT |
1018 | /* |
1019 | * handle_stripe - do things to a stripe. | |
1020 | * | |
1021 | * We lock the stripe and then examine the state of various bits | |
1022 | * to see what needs to be done. | |
1023 | * Possible results: | |
1024 | * return some read request which now have data | |
1025 | * return some write requests which are safely on disc | |
1026 | * schedule a read on some buffers | |
1027 | * schedule a write of some buffers | |
1028 | * return confirmation of parity correctness | |
1029 | * | |
1030 | * Parity calculations are done inside the stripe lock | |
1031 | * buffers are taken off read_list or write_list, and bh_cache buffers | |
1032 | * get BH_Lock set before the stripe lock is released. | |
1033 | * | |
1034 | */ | |
1035 | ||
ca65b73b | 1036 | static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) |
1da177e4 LT |
1037 | { |
1038 | raid6_conf_t *conf = sh->raid_conf; | |
1039 | int disks = conf->raid_disks; | |
1040 | struct bio *return_bi= NULL; | |
1041 | struct bio *bi; | |
1042 | int i; | |
1043 | int syncing; | |
1044 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; | |
1045 | int non_overwrite = 0; | |
1046 | int failed_num[2] = {0, 0}; | |
1047 | struct r5dev *dev, *pdev, *qdev; | |
1048 | int pd_idx = sh->pd_idx; | |
1049 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
1050 | int p_failed, q_failed; | |
1051 | ||
1052 | PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", | |
1053 | (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), | |
1054 | pd_idx, qd_idx); | |
1055 | ||
1056 | spin_lock(&sh->lock); | |
1057 | clear_bit(STRIPE_HANDLE, &sh->state); | |
1058 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1059 | ||
1060 | syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
1061 | /* Now to look around and see what can be done */ | |
1062 | ||
9910f16a | 1063 | rcu_read_lock(); |
1da177e4 LT |
1064 | for (i=disks; i--; ) { |
1065 | mdk_rdev_t *rdev; | |
1066 | dev = &sh->dev[i]; | |
1067 | clear_bit(R5_Insync, &dev->flags); | |
1da177e4 LT |
1068 | |
1069 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", | |
1070 | i, dev->flags, dev->toread, dev->towrite, dev->written); | |
1071 | /* maybe we can reply to a read */ | |
1072 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | |
1073 | struct bio *rbi, *rbi2; | |
1074 | PRINTK("Return read for disc %d\n", i); | |
1075 | spin_lock_irq(&conf->device_lock); | |
1076 | rbi = dev->toread; | |
1077 | dev->toread = NULL; | |
1078 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
1079 | wake_up(&conf->wait_for_overlap); | |
1080 | spin_unlock_irq(&conf->device_lock); | |
1081 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1082 | copy_data(0, rbi, dev->page, dev->sector); | |
1083 | rbi2 = r5_next_bio(rbi, dev->sector); | |
1084 | spin_lock_irq(&conf->device_lock); | |
1085 | if (--rbi->bi_phys_segments == 0) { | |
1086 | rbi->bi_next = return_bi; | |
1087 | return_bi = rbi; | |
1088 | } | |
1089 | spin_unlock_irq(&conf->device_lock); | |
1090 | rbi = rbi2; | |
1091 | } | |
1092 | } | |
1093 | ||
1094 | /* now count some things */ | |
1095 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; | |
1096 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; | |
1097 | ||
1098 | ||
1099 | if (dev->toread) to_read++; | |
1100 | if (dev->towrite) { | |
1101 | to_write++; | |
1102 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
1103 | non_overwrite++; | |
1104 | } | |
1105 | if (dev->written) written++; | |
9910f16a | 1106 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1107 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
d69762e9 N |
1108 | /* The ReadError flag will just be confusing now */ |
1109 | clear_bit(R5_ReadError, &dev->flags); | |
1110 | clear_bit(R5_ReWrite, &dev->flags); | |
1111 | } | |
1112 | if (!rdev || !test_bit(In_sync, &rdev->flags) | |
1113 | || test_bit(R5_ReadError, &dev->flags)) { | |
1da177e4 LT |
1114 | if ( failed < 2 ) |
1115 | failed_num[failed] = i; | |
1116 | failed++; | |
1117 | } else | |
1118 | set_bit(R5_Insync, &dev->flags); | |
1119 | } | |
9910f16a | 1120 | rcu_read_unlock(); |
1da177e4 LT |
1121 | PRINTK("locked=%d uptodate=%d to_read=%d" |
1122 | " to_write=%d failed=%d failed_num=%d,%d\n", | |
1123 | locked, uptodate, to_read, to_write, failed, | |
1124 | failed_num[0], failed_num[1]); | |
1125 | /* check if the array has lost >2 devices and, if so, some requests might | |
1126 | * need to be failed | |
1127 | */ | |
1128 | if (failed > 2 && to_read+to_write+written) { | |
1da177e4 | 1129 | for (i=disks; i--; ) { |
934ce7c8 | 1130 | int bitmap_end = 0; |
d69762e9 N |
1131 | |
1132 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
9910f16a N |
1133 | mdk_rdev_t *rdev; |
1134 | rcu_read_lock(); | |
1135 | rdev = rcu_dereference(conf->disks[i].rdev); | |
d69762e9 N |
1136 | if (rdev && test_bit(In_sync, &rdev->flags)) |
1137 | /* multiple read failures in one stripe */ | |
1138 | md_error(conf->mddev, rdev); | |
9910f16a | 1139 | rcu_read_unlock(); |
d69762e9 N |
1140 | } |
1141 | ||
934ce7c8 | 1142 | spin_lock_irq(&conf->device_lock); |
1da177e4 LT |
1143 | /* fail all writes first */ |
1144 | bi = sh->dev[i].towrite; | |
1145 | sh->dev[i].towrite = NULL; | |
934ce7c8 | 1146 | if (bi) { to_write--; bitmap_end = 1; } |
1da177e4 LT |
1147 | |
1148 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1149 | wake_up(&conf->wait_for_overlap); | |
1150 | ||
1151 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1152 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1153 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1154 | if (--bi->bi_phys_segments == 0) { | |
1155 | md_write_end(conf->mddev); | |
1156 | bi->bi_next = return_bi; | |
1157 | return_bi = bi; | |
1158 | } | |
1159 | bi = nextbi; | |
1160 | } | |
1161 | /* and fail all 'written' */ | |
1162 | bi = sh->dev[i].written; | |
1163 | sh->dev[i].written = NULL; | |
934ce7c8 | 1164 | if (bi) bitmap_end = 1; |
1da177e4 LT |
1165 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { |
1166 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | |
1167 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1168 | if (--bi->bi_phys_segments == 0) { | |
1169 | md_write_end(conf->mddev); | |
1170 | bi->bi_next = return_bi; | |
1171 | return_bi = bi; | |
1172 | } | |
1173 | bi = bi2; | |
1174 | } | |
1175 | ||
1176 | /* fail any reads if this device is non-operational */ | |
d69762e9 N |
1177 | if (!test_bit(R5_Insync, &sh->dev[i].flags) || |
1178 | test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
1da177e4 LT |
1179 | bi = sh->dev[i].toread; |
1180 | sh->dev[i].toread = NULL; | |
1181 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1182 | wake_up(&conf->wait_for_overlap); | |
1183 | if (bi) to_read--; | |
1184 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1185 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1186 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1187 | if (--bi->bi_phys_segments == 0) { | |
1188 | bi->bi_next = return_bi; | |
1189 | return_bi = bi; | |
1190 | } | |
1191 | bi = nextbi; | |
1192 | } | |
1193 | } | |
934ce7c8 N |
1194 | spin_unlock_irq(&conf->device_lock); |
1195 | if (bitmap_end) | |
1196 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1197 | STRIPE_SECTORS, 0, 0); | |
1da177e4 | 1198 | } |
1da177e4 LT |
1199 | } |
1200 | if (failed > 2 && syncing) { | |
1201 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
1202 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1203 | syncing = 0; | |
1204 | } | |
1205 | ||
1206 | /* | |
1207 | * might be able to return some write requests if the parity blocks | |
1208 | * are safe, or on a failed drive | |
1209 | */ | |
1210 | pdev = &sh->dev[pd_idx]; | |
1211 | p_failed = (failed >= 1 && failed_num[0] == pd_idx) | |
1212 | || (failed >= 2 && failed_num[1] == pd_idx); | |
1213 | qdev = &sh->dev[qd_idx]; | |
1214 | q_failed = (failed >= 1 && failed_num[0] == qd_idx) | |
1215 | || (failed >= 2 && failed_num[1] == qd_idx); | |
1216 | ||
1217 | if ( written && | |
1218 | ( p_failed || ((test_bit(R5_Insync, &pdev->flags) | |
1219 | && !test_bit(R5_LOCKED, &pdev->flags) | |
1220 | && test_bit(R5_UPTODATE, &pdev->flags))) ) && | |
1221 | ( q_failed || ((test_bit(R5_Insync, &qdev->flags) | |
1222 | && !test_bit(R5_LOCKED, &qdev->flags) | |
1223 | && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { | |
1224 | /* any written block on an uptodate or failed drive can be | |
1225 | * returned. Note that if we 'wrote' to a failed drive, | |
1226 | * it will be UPTODATE, but never LOCKED, so we don't need | |
1227 | * to test 'failed' directly. | |
1228 | */ | |
1229 | for (i=disks; i--; ) | |
1230 | if (sh->dev[i].written) { | |
1231 | dev = &sh->dev[i]; | |
1232 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1233 | test_bit(R5_UPTODATE, &dev->flags) ) { | |
1234 | /* We can return any write requests */ | |
934ce7c8 | 1235 | int bitmap_end = 0; |
1da177e4 LT |
1236 | struct bio *wbi, *wbi2; |
1237 | PRINTK("Return write for stripe %llu disc %d\n", | |
1238 | (unsigned long long)sh->sector, i); | |
1239 | spin_lock_irq(&conf->device_lock); | |
1240 | wbi = dev->written; | |
1241 | dev->written = NULL; | |
1242 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1243 | wbi2 = r5_next_bio(wbi, dev->sector); | |
1244 | if (--wbi->bi_phys_segments == 0) { | |
1245 | md_write_end(conf->mddev); | |
1246 | wbi->bi_next = return_bi; | |
1247 | return_bi = wbi; | |
1248 | } | |
1249 | wbi = wbi2; | |
1250 | } | |
934ce7c8 N |
1251 | if (dev->towrite == NULL) |
1252 | bitmap_end = 1; | |
1da177e4 | 1253 | spin_unlock_irq(&conf->device_lock); |
934ce7c8 N |
1254 | if (bitmap_end) |
1255 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1256 | STRIPE_SECTORS, | |
1257 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); | |
1da177e4 LT |
1258 | } |
1259 | } | |
1260 | } | |
1261 | ||
1262 | /* Now we might consider reading some blocks, either to check/generate | |
1263 | * parity, or to satisfy requests | |
1264 | * or to load a block that is being partially written. | |
1265 | */ | |
1266 | if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { | |
1267 | for (i=disks; i--;) { | |
1268 | dev = &sh->dev[i]; | |
1269 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1270 | (dev->toread || | |
1271 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1272 | syncing || | |
1273 | (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || | |
1274 | (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) | |
1275 | ) | |
1276 | ) { | |
1277 | /* we would like to get this block, possibly | |
1278 | * by computing it, but we might not be able to | |
1279 | */ | |
1280 | if (uptodate == disks-1) { | |
1281 | PRINTK("Computing stripe %llu block %d\n", | |
1282 | (unsigned long long)sh->sector, i); | |
ca65b73b | 1283 | compute_block_1(sh, i, 0); |
1da177e4 LT |
1284 | uptodate++; |
1285 | } else if ( uptodate == disks-2 && failed >= 2 ) { | |
1286 | /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ | |
1287 | int other; | |
1288 | for (other=disks; other--;) { | |
1289 | if ( other == i ) | |
1290 | continue; | |
1291 | if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) | |
1292 | break; | |
1293 | } | |
1294 | BUG_ON(other < 0); | |
1295 | PRINTK("Computing stripe %llu blocks %d,%d\n", | |
1296 | (unsigned long long)sh->sector, i, other); | |
1297 | compute_block_2(sh, i, other); | |
1298 | uptodate += 2; | |
1299 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1300 | set_bit(R5_LOCKED, &dev->flags); | |
1301 | set_bit(R5_Wantread, &dev->flags); | |
1302 | #if 0 | |
1303 | /* if I am just reading this block and we don't have | |
1304 | a failed drive, or any pending writes then sidestep the cache */ | |
1305 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && | |
1306 | ! syncing && !failed && !to_write) { | |
1307 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; | |
1308 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; | |
1309 | } | |
1310 | #endif | |
1311 | locked++; | |
1312 | PRINTK("Reading block %d (sync=%d)\n", | |
1313 | i, syncing); | |
1da177e4 LT |
1314 | } |
1315 | } | |
1316 | } | |
1317 | set_bit(STRIPE_HANDLE, &sh->state); | |
1318 | } | |
1319 | ||
1320 | /* now to consider writing and what else, if anything should be read */ | |
1321 | if (to_write) { | |
1322 | int rcw=0, must_compute=0; | |
1323 | for (i=disks ; i--;) { | |
1324 | dev = &sh->dev[i]; | |
1325 | /* Would I have to read this buffer for reconstruct_write */ | |
1326 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
1327 | && i != pd_idx && i != qd_idx | |
1328 | && (!test_bit(R5_LOCKED, &dev->flags) | |
1329 | #if 0 | |
1330 | || sh->bh_page[i] != bh->b_page | |
1331 | #endif | |
1332 | ) && | |
1333 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1334 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
1335 | else { | |
1336 | PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); | |
1337 | must_compute++; | |
1338 | } | |
1339 | } | |
1340 | } | |
1341 | PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", | |
1342 | (unsigned long long)sh->sector, rcw, must_compute); | |
1343 | set_bit(STRIPE_HANDLE, &sh->state); | |
1344 | ||
1345 | if (rcw > 0) | |
1346 | /* want reconstruct write, but need to get some data */ | |
1347 | for (i=disks; i--;) { | |
1348 | dev = &sh->dev[i]; | |
1349 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
1350 | && !(failed == 0 && (i == pd_idx || i == qd_idx)) | |
1351 | && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1352 | test_bit(R5_Insync, &dev->flags)) { | |
1353 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1354 | { | |
1355 | PRINTK("Read_old stripe %llu block %d for Reconstruct\n", | |
1356 | (unsigned long long)sh->sector, i); | |
1357 | set_bit(R5_LOCKED, &dev->flags); | |
1358 | set_bit(R5_Wantread, &dev->flags); | |
1359 | locked++; | |
1360 | } else { | |
1361 | PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", | |
1362 | (unsigned long long)sh->sector, i); | |
1363 | set_bit(STRIPE_DELAYED, &sh->state); | |
1364 | set_bit(STRIPE_HANDLE, &sh->state); | |
1365 | } | |
1366 | } | |
1367 | } | |
1368 | /* now if nothing is locked, and if we have enough data, we can start a write request */ | |
934ce7c8 N |
1369 | if (locked == 0 && rcw == 0 && |
1370 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | |
1da177e4 LT |
1371 | if ( must_compute > 0 ) { |
1372 | /* We have failed blocks and need to compute them */ | |
1373 | switch ( failed ) { | |
1374 | case 0: BUG(); | |
ca65b73b | 1375 | case 1: compute_block_1(sh, failed_num[0], 0); break; |
1da177e4 LT |
1376 | case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; |
1377 | default: BUG(); /* This request should have been failed? */ | |
1378 | } | |
1379 | } | |
1380 | ||
1381 | PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); | |
1382 | compute_parity(sh, RECONSTRUCT_WRITE); | |
1383 | /* now every locked buffer is ready to be written */ | |
1384 | for (i=disks; i--;) | |
1385 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | |
1386 | PRINTK("Writing stripe %llu block %d\n", | |
1387 | (unsigned long long)sh->sector, i); | |
1388 | locked++; | |
1389 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
1da177e4 | 1390 | } |
ca65b73b N |
1391 | /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ |
1392 | set_bit(STRIPE_INSYNC, &sh->state); | |
1393 | ||
1da177e4 LT |
1394 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
1395 | atomic_dec(&conf->preread_active_stripes); | |
1396 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
1397 | md_wakeup_thread(conf->mddev->thread); | |
1398 | } | |
1399 | } | |
1400 | } | |
1401 | ||
1402 | /* maybe we need to check and possibly fix the parity for this stripe | |
1403 | * Any reads will already have been scheduled, so we just see if enough data | |
1404 | * is available | |
1405 | */ | |
ca65b73b N |
1406 | if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) { |
1407 | int update_p = 0, update_q = 0; | |
1408 | struct r5dev *dev; | |
1da177e4 | 1409 | |
ca65b73b | 1410 | set_bit(STRIPE_HANDLE, &sh->state); |
1da177e4 | 1411 | |
ca65b73b N |
1412 | BUG_ON(failed>2); |
1413 | BUG_ON(uptodate < disks); | |
1414 | /* Want to check and possibly repair P and Q. | |
1415 | * However there could be one 'failed' device, in which | |
1416 | * case we can only check one of them, possibly using the | |
1417 | * other to generate missing data | |
1418 | */ | |
1da177e4 | 1419 | |
ca65b73b N |
1420 | /* If !tmp_page, we cannot do the calculations, |
1421 | * but as we have set STRIPE_HANDLE, we will soon be called | |
1422 | * by stripe_handle with a tmp_page - just wait until then. | |
1423 | */ | |
1424 | if (tmp_page) { | |
1425 | if (failed == q_failed) { | |
1426 | /* The only possible failed device holds 'Q', so it makes | |
1427 | * sense to check P (If anything else were failed, we would | |
1428 | * have used P to recreate it). | |
1429 | */ | |
1430 | compute_block_1(sh, pd_idx, 1); | |
1431 | if (!page_is_zero(sh->dev[pd_idx].page)) { | |
1432 | compute_block_1(sh,pd_idx,0); | |
1433 | update_p = 1; | |
1434 | } | |
1435 | } | |
1436 | if (!q_failed && failed < 2) { | |
1437 | /* q is not failed, and we didn't use it to generate | |
1438 | * anything, so it makes sense to check it | |
1439 | */ | |
1440 | memcpy(page_address(tmp_page), | |
1441 | page_address(sh->dev[qd_idx].page), | |
1442 | STRIPE_SIZE); | |
1443 | compute_parity(sh, UPDATE_PARITY); | |
1444 | if (memcmp(page_address(tmp_page), | |
1445 | page_address(sh->dev[qd_idx].page), | |
1446 | STRIPE_SIZE)!= 0) { | |
1447 | clear_bit(STRIPE_INSYNC, &sh->state); | |
1448 | update_q = 1; | |
1449 | } | |
1450 | } | |
1451 | if (update_p || update_q) { | |
1452 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | |
1453 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | |
1454 | /* don't try to repair!! */ | |
1455 | update_p = update_q = 0; | |
1da177e4 | 1456 | } |
1da177e4 | 1457 | |
ca65b73b N |
1458 | /* now write out any block on a failed drive, |
1459 | * or P or Q if they need it | |
1460 | */ | |
1da177e4 | 1461 | |
ca65b73b N |
1462 | if (failed == 2) { |
1463 | dev = &sh->dev[failed_num[1]]; | |
1464 | locked++; | |
1465 | set_bit(R5_LOCKED, &dev->flags); | |
1466 | set_bit(R5_Wantwrite, &dev->flags); | |
ca65b73b N |
1467 | } |
1468 | if (failed >= 1) { | |
1469 | dev = &sh->dev[failed_num[0]]; | |
1470 | locked++; | |
1471 | set_bit(R5_LOCKED, &dev->flags); | |
1472 | set_bit(R5_Wantwrite, &dev->flags); | |
ca65b73b | 1473 | } |
1da177e4 | 1474 | |
ca65b73b N |
1475 | if (update_p) { |
1476 | dev = &sh->dev[pd_idx]; | |
1477 | locked ++; | |
1478 | set_bit(R5_LOCKED, &dev->flags); | |
1479 | set_bit(R5_Wantwrite, &dev->flags); | |
ca65b73b N |
1480 | } |
1481 | if (update_q) { | |
1482 | dev = &sh->dev[qd_idx]; | |
1483 | locked++; | |
1484 | set_bit(R5_LOCKED, &dev->flags); | |
1485 | set_bit(R5_Wantwrite, &dev->flags); | |
ca65b73b | 1486 | } |
934ce7c8 | 1487 | clear_bit(STRIPE_DEGRADED, &sh->state); |
1da177e4 LT |
1488 | |
1489 | set_bit(STRIPE_INSYNC, &sh->state); | |
1da177e4 LT |
1490 | } |
1491 | } | |
ca65b73b | 1492 | |
1da177e4 LT |
1493 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { |
1494 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
1495 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1496 | } | |
1497 | ||
d69762e9 N |
1498 | /* If the failed drives are just a ReadError, then we might need |
1499 | * to progress the repair/check process | |
1500 | */ | |
1501 | if (failed <= 2 && ! conf->mddev->ro) | |
1502 | for (i=0; i<failed;i++) { | |
1503 | dev = &sh->dev[failed_num[i]]; | |
1504 | if (test_bit(R5_ReadError, &dev->flags) | |
1505 | && !test_bit(R5_LOCKED, &dev->flags) | |
1506 | && test_bit(R5_UPTODATE, &dev->flags) | |
1507 | ) { | |
1508 | if (!test_bit(R5_ReWrite, &dev->flags)) { | |
1509 | set_bit(R5_Wantwrite, &dev->flags); | |
1510 | set_bit(R5_ReWrite, &dev->flags); | |
1511 | set_bit(R5_LOCKED, &dev->flags); | |
1512 | } else { | |
1513 | /* let's read it back */ | |
1514 | set_bit(R5_Wantread, &dev->flags); | |
1515 | set_bit(R5_LOCKED, &dev->flags); | |
1516 | } | |
1517 | } | |
1518 | } | |
1da177e4 LT |
1519 | spin_unlock(&sh->lock); |
1520 | ||
1521 | while ((bi=return_bi)) { | |
1522 | int bytes = bi->bi_size; | |
1523 | ||
1524 | return_bi = bi->bi_next; | |
1525 | bi->bi_next = NULL; | |
1526 | bi->bi_size = 0; | |
1527 | bi->bi_end_io(bi, bytes, 0); | |
1528 | } | |
1529 | for (i=disks; i-- ;) { | |
1530 | int rw; | |
1531 | struct bio *bi; | |
1532 | mdk_rdev_t *rdev; | |
1533 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | |
1534 | rw = 1; | |
1535 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | |
1536 | rw = 0; | |
1537 | else | |
1538 | continue; | |
1539 | ||
1540 | bi = &sh->dev[i].req; | |
1541 | ||
1542 | bi->bi_rw = rw; | |
1543 | if (rw) | |
1544 | bi->bi_end_io = raid6_end_write_request; | |
1545 | else | |
1546 | bi->bi_end_io = raid6_end_read_request; | |
1547 | ||
1548 | rcu_read_lock(); | |
d6065f7b | 1549 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1550 | if (rdev && test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
1551 | rdev = NULL; |
1552 | if (rdev) | |
1553 | atomic_inc(&rdev->nr_pending); | |
1554 | rcu_read_unlock(); | |
1555 | ||
1556 | if (rdev) { | |
9910f16a | 1557 | if (syncing) |
1da177e4 LT |
1558 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
1559 | ||
1560 | bi->bi_bdev = rdev->bdev; | |
1561 | PRINTK("for %llu schedule op %ld on disc %d\n", | |
1562 | (unsigned long long)sh->sector, bi->bi_rw, i); | |
1563 | atomic_inc(&sh->count); | |
1564 | bi->bi_sector = sh->sector + rdev->data_offset; | |
1565 | bi->bi_flags = 1 << BIO_UPTODATE; | |
1566 | bi->bi_vcnt = 1; | |
1567 | bi->bi_max_vecs = 1; | |
1568 | bi->bi_idx = 0; | |
1569 | bi->bi_io_vec = &sh->dev[i].vec; | |
1570 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | |
1571 | bi->bi_io_vec[0].bv_offset = 0; | |
1572 | bi->bi_size = STRIPE_SIZE; | |
1573 | bi->bi_next = NULL; | |
1574 | generic_make_request(bi); | |
1575 | } else { | |
934ce7c8 N |
1576 | if (rw == 1) |
1577 | set_bit(STRIPE_DEGRADED, &sh->state); | |
1da177e4 LT |
1578 | PRINTK("skip op %ld on disc %d for sector %llu\n", |
1579 | bi->bi_rw, i, (unsigned long long)sh->sector); | |
1580 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1581 | set_bit(STRIPE_HANDLE, &sh->state); | |
1582 | } | |
1583 | } | |
1584 | } | |
1585 | ||
1586 | static inline void raid6_activate_delayed(raid6_conf_t *conf) | |
1587 | { | |
1588 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | |
1589 | while (!list_empty(&conf->delayed_list)) { | |
1590 | struct list_head *l = conf->delayed_list.next; | |
1591 | struct stripe_head *sh; | |
1592 | sh = list_entry(l, struct stripe_head, lru); | |
1593 | list_del_init(l); | |
1594 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1595 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1596 | atomic_inc(&conf->preread_active_stripes); | |
1597 | list_add_tail(&sh->lru, &conf->handle_list); | |
1598 | } | |
1599 | } | |
1600 | } | |
1601 | ||
934ce7c8 N |
1602 | static inline void activate_bit_delay(raid6_conf_t *conf) |
1603 | { | |
1604 | /* device_lock is held */ | |
1605 | struct list_head head; | |
1606 | list_add(&head, &conf->bitmap_list); | |
1607 | list_del_init(&conf->bitmap_list); | |
1608 | while (!list_empty(&head)) { | |
1609 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | |
1610 | list_del_init(&sh->lru); | |
1611 | atomic_inc(&sh->count); | |
1612 | __release_stripe(conf, sh); | |
1613 | } | |
1614 | } | |
1615 | ||
1da177e4 LT |
1616 | static void unplug_slaves(mddev_t *mddev) |
1617 | { | |
1618 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1619 | int i; | |
1620 | ||
1621 | rcu_read_lock(); | |
1622 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 1623 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1624 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
1da177e4 LT |
1625 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
1626 | ||
1627 | atomic_inc(&rdev->nr_pending); | |
1628 | rcu_read_unlock(); | |
1629 | ||
1630 | if (r_queue->unplug_fn) | |
1631 | r_queue->unplug_fn(r_queue); | |
1632 | ||
1633 | rdev_dec_pending(rdev, mddev); | |
1634 | rcu_read_lock(); | |
1635 | } | |
1636 | } | |
1637 | rcu_read_unlock(); | |
1638 | } | |
1639 | ||
1640 | static void raid6_unplug_device(request_queue_t *q) | |
1641 | { | |
1642 | mddev_t *mddev = q->queuedata; | |
1643 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1644 | unsigned long flags; | |
1645 | ||
1646 | spin_lock_irqsave(&conf->device_lock, flags); | |
1647 | ||
934ce7c8 N |
1648 | if (blk_remove_plug(q)) { |
1649 | conf->seq_flush++; | |
1da177e4 | 1650 | raid6_activate_delayed(conf); |
934ce7c8 | 1651 | } |
1da177e4 LT |
1652 | md_wakeup_thread(mddev->thread); |
1653 | ||
1654 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1655 | ||
1656 | unplug_slaves(mddev); | |
1657 | } | |
1658 | ||
1659 | static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk, | |
1660 | sector_t *error_sector) | |
1661 | { | |
1662 | mddev_t *mddev = q->queuedata; | |
1663 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1664 | int i, ret = 0; | |
1665 | ||
1666 | rcu_read_lock(); | |
1667 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 1668 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1669 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
1670 | struct block_device *bdev = rdev->bdev; |
1671 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
1672 | ||
1673 | if (!r_queue->issue_flush_fn) | |
1674 | ret = -EOPNOTSUPP; | |
1675 | else { | |
1676 | atomic_inc(&rdev->nr_pending); | |
1677 | rcu_read_unlock(); | |
1678 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
1679 | error_sector); | |
1680 | rdev_dec_pending(rdev, mddev); | |
1681 | rcu_read_lock(); | |
1682 | } | |
1683 | } | |
1684 | } | |
1685 | rcu_read_unlock(); | |
1686 | return ret; | |
1687 | } | |
1688 | ||
1689 | static inline void raid6_plug_device(raid6_conf_t *conf) | |
1690 | { | |
1691 | spin_lock_irq(&conf->device_lock); | |
1692 | blk_plug_device(conf->mddev->queue); | |
1693 | spin_unlock_irq(&conf->device_lock); | |
1694 | } | |
1695 | ||
1696 | static int make_request (request_queue_t *q, struct bio * bi) | |
1697 | { | |
1698 | mddev_t *mddev = q->queuedata; | |
1699 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1700 | const unsigned int raid_disks = conf->raid_disks; | |
1701 | const unsigned int data_disks = raid_disks - 2; | |
1702 | unsigned int dd_idx, pd_idx; | |
1703 | sector_t new_sector; | |
1704 | sector_t logical_sector, last_sector; | |
1705 | struct stripe_head *sh; | |
a362357b | 1706 | const int rw = bio_data_dir(bi); |
1da177e4 | 1707 | |
e5dcdd80 N |
1708 | if (unlikely(bio_barrier(bi))) { |
1709 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); | |
1710 | return 0; | |
1711 | } | |
1712 | ||
3d310eb7 | 1713 | md_write_start(mddev, bi); |
06d91a5f | 1714 | |
a362357b JA |
1715 | disk_stat_inc(mddev->gendisk, ios[rw]); |
1716 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | |
1da177e4 LT |
1717 | |
1718 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
1719 | last_sector = bi->bi_sector + (bi->bi_size>>9); | |
1720 | ||
1721 | bi->bi_next = NULL; | |
1722 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | |
06d91a5f | 1723 | |
1da177e4 LT |
1724 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
1725 | DEFINE_WAIT(w); | |
1726 | ||
1727 | new_sector = raid6_compute_sector(logical_sector, | |
1728 | raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1729 | ||
1730 | PRINTK("raid6: make_request, sector %llu logical %llu\n", | |
1731 | (unsigned long long)new_sector, | |
1732 | (unsigned long long)logical_sector); | |
1733 | ||
1734 | retry: | |
1735 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); | |
1736 | sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); | |
1737 | if (sh) { | |
1738 | if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | |
1739 | /* Add failed due to overlap. Flush everything | |
1740 | * and wait a while | |
1741 | */ | |
1742 | raid6_unplug_device(mddev->queue); | |
1743 | release_stripe(sh); | |
1744 | schedule(); | |
1745 | goto retry; | |
1746 | } | |
1747 | finish_wait(&conf->wait_for_overlap, &w); | |
1748 | raid6_plug_device(conf); | |
ca65b73b | 1749 | handle_stripe(sh, NULL); |
1da177e4 LT |
1750 | release_stripe(sh); |
1751 | } else { | |
1752 | /* cannot get stripe for read-ahead, just give-up */ | |
1753 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1754 | finish_wait(&conf->wait_for_overlap, &w); | |
1755 | break; | |
1756 | } | |
1757 | ||
1758 | } | |
1759 | spin_lock_irq(&conf->device_lock); | |
1760 | if (--bi->bi_phys_segments == 0) { | |
1761 | int bytes = bi->bi_size; | |
1762 | ||
a362357b | 1763 | if (rw == WRITE ) |
1da177e4 LT |
1764 | md_write_end(mddev); |
1765 | bi->bi_size = 0; | |
1766 | bi->bi_end_io(bi, bytes, 0); | |
1767 | } | |
1768 | spin_unlock_irq(&conf->device_lock); | |
1769 | return 0; | |
1770 | } | |
1771 | ||
1772 | /* FIXME go_faster isn't used */ | |
57afd89f | 1773 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1774 | { |
1775 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
1776 | struct stripe_head *sh; | |
1777 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1778 | sector_t x; | |
1779 | unsigned long stripe; | |
1780 | int chunk_offset; | |
1781 | int dd_idx, pd_idx; | |
1782 | sector_t first_sector; | |
1783 | int raid_disks = conf->raid_disks; | |
1784 | int data_disks = raid_disks - 2; | |
934ce7c8 N |
1785 | sector_t max_sector = mddev->size << 1; |
1786 | int sync_blocks; | |
b5ab28a3 N |
1787 | int still_degraded = 0; |
1788 | int i; | |
1da177e4 | 1789 | |
934ce7c8 | 1790 | if (sector_nr >= max_sector) { |
1da177e4 LT |
1791 | /* just being told to finish up .. nothing much to do */ |
1792 | unplug_slaves(mddev); | |
934ce7c8 N |
1793 | |
1794 | if (mddev->curr_resync < max_sector) /* aborted */ | |
1795 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1796 | &sync_blocks, 1); | |
b5ab28a3 | 1797 | else /* completed sync */ |
934ce7c8 N |
1798 | conf->fullsync = 0; |
1799 | bitmap_close_sync(mddev->bitmap); | |
1800 | ||
1da177e4 LT |
1801 | return 0; |
1802 | } | |
1803 | /* if there are 2 or more failed drives and we are trying | |
1804 | * to resync, then assert that we are finished, because there is | |
1805 | * nothing we can do. | |
1806 | */ | |
1807 | if (mddev->degraded >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
57afd89f N |
1808 | sector_t rv = (mddev->size << 1) - sector_nr; |
1809 | *skipped = 1; | |
1da177e4 LT |
1810 | return rv; |
1811 | } | |
934ce7c8 | 1812 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
ca65b73b | 1813 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
934ce7c8 N |
1814 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { |
1815 | /* we can skip this block, and probably more */ | |
1816 | sync_blocks /= STRIPE_SECTORS; | |
1817 | *skipped = 1; | |
1818 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | |
1819 | } | |
1da177e4 LT |
1820 | |
1821 | x = sector_nr; | |
1822 | chunk_offset = sector_div(x, sectors_per_chunk); | |
1823 | stripe = x; | |
1824 | BUG_ON(x != stripe); | |
1825 | ||
1826 | first_sector = raid6_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk | |
1827 | + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1828 | sh = get_active_stripe(conf, sector_nr, pd_idx, 1); | |
1829 | if (sh == NULL) { | |
1830 | sh = get_active_stripe(conf, sector_nr, pd_idx, 0); | |
1831 | /* make sure we don't swamp the stripe cache if someone else | |
1832 | * is trying to get access | |
1833 | */ | |
66c006a5 | 1834 | schedule_timeout_uninterruptible(1); |
1da177e4 | 1835 | } |
b5ab28a3 N |
1836 | /* Need to check if array will still be degraded after recovery/resync |
1837 | * We don't need to check the 'failed' flag as when that gets set, | |
1838 | * recovery aborts. | |
1839 | */ | |
1840 | for (i=0; i<mddev->raid_disks; i++) | |
1841 | if (conf->disks[i].rdev == NULL) | |
1842 | still_degraded = 1; | |
1843 | ||
1844 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); | |
1845 | ||
1da177e4 LT |
1846 | spin_lock(&sh->lock); |
1847 | set_bit(STRIPE_SYNCING, &sh->state); | |
1848 | clear_bit(STRIPE_INSYNC, &sh->state); | |
1849 | spin_unlock(&sh->lock); | |
1850 | ||
ca65b73b | 1851 | handle_stripe(sh, NULL); |
1da177e4 LT |
1852 | release_stripe(sh); |
1853 | ||
1854 | return STRIPE_SECTORS; | |
1855 | } | |
1856 | ||
1857 | /* | |
1858 | * This is our raid6 kernel thread. | |
1859 | * | |
1860 | * We scan the hash table for stripes which can be handled now. | |
1861 | * During the scan, completed stripes are saved for us by the interrupt | |
1862 | * handler, so that they will not have to wait for our next wakeup. | |
1863 | */ | |
1864 | static void raid6d (mddev_t *mddev) | |
1865 | { | |
1866 | struct stripe_head *sh; | |
1867 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1868 | int handled; | |
1869 | ||
1870 | PRINTK("+++ raid6d active\n"); | |
1871 | ||
1872 | md_check_recovery(mddev); | |
1da177e4 LT |
1873 | |
1874 | handled = 0; | |
1875 | spin_lock_irq(&conf->device_lock); | |
1876 | while (1) { | |
1877 | struct list_head *first; | |
1878 | ||
934ce7c8 N |
1879 | if (conf->seq_flush - conf->seq_write > 0) { |
1880 | int seq = conf->seq_flush; | |
700e432d | 1881 | spin_unlock_irq(&conf->device_lock); |
934ce7c8 | 1882 | bitmap_unplug(mddev->bitmap); |
700e432d | 1883 | spin_lock_irq(&conf->device_lock); |
934ce7c8 N |
1884 | conf->seq_write = seq; |
1885 | activate_bit_delay(conf); | |
1886 | } | |
1887 | ||
1da177e4 LT |
1888 | if (list_empty(&conf->handle_list) && |
1889 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && | |
1890 | !blk_queue_plugged(mddev->queue) && | |
1891 | !list_empty(&conf->delayed_list)) | |
1892 | raid6_activate_delayed(conf); | |
1893 | ||
1894 | if (list_empty(&conf->handle_list)) | |
1895 | break; | |
1896 | ||
1897 | first = conf->handle_list.next; | |
1898 | sh = list_entry(first, struct stripe_head, lru); | |
1899 | ||
1900 | list_del_init(first); | |
1901 | atomic_inc(&sh->count); | |
1902 | if (atomic_read(&sh->count)!= 1) | |
1903 | BUG(); | |
1904 | spin_unlock_irq(&conf->device_lock); | |
1905 | ||
1906 | handled++; | |
ca65b73b | 1907 | handle_stripe(sh, conf->spare_page); |
1da177e4 LT |
1908 | release_stripe(sh); |
1909 | ||
1910 | spin_lock_irq(&conf->device_lock); | |
1911 | } | |
1912 | PRINTK("%d stripes handled\n", handled); | |
1913 | ||
1914 | spin_unlock_irq(&conf->device_lock); | |
1915 | ||
1916 | unplug_slaves(mddev); | |
1917 | ||
1918 | PRINTK("--- raid6d inactive\n"); | |
1919 | } | |
1920 | ||
934ce7c8 | 1921 | static int run(mddev_t *mddev) |
1da177e4 LT |
1922 | { |
1923 | raid6_conf_t *conf; | |
1924 | int raid_disk, memory; | |
1925 | mdk_rdev_t *rdev; | |
1926 | struct disk_info *disk; | |
1927 | struct list_head *tmp; | |
1928 | ||
1929 | if (mddev->level != 6) { | |
1930 | PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level); | |
1931 | return -EIO; | |
1932 | } | |
1933 | ||
1934 | mddev->private = kmalloc (sizeof (raid6_conf_t) | |
1935 | + mddev->raid_disks * sizeof(struct disk_info), | |
1936 | GFP_KERNEL); | |
1937 | if ((conf = mddev->private) == NULL) | |
1938 | goto abort; | |
1939 | memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) ); | |
1940 | conf->mddev = mddev; | |
1941 | ||
1942 | if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL) | |
1943 | goto abort; | |
1944 | memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE); | |
1945 | ||
ca65b73b N |
1946 | conf->spare_page = alloc_page(GFP_KERNEL); |
1947 | if (!conf->spare_page) | |
1948 | goto abort; | |
1949 | ||
1da177e4 LT |
1950 | spin_lock_init(&conf->device_lock); |
1951 | init_waitqueue_head(&conf->wait_for_stripe); | |
1952 | init_waitqueue_head(&conf->wait_for_overlap); | |
1953 | INIT_LIST_HEAD(&conf->handle_list); | |
1954 | INIT_LIST_HEAD(&conf->delayed_list); | |
934ce7c8 | 1955 | INIT_LIST_HEAD(&conf->bitmap_list); |
1da177e4 LT |
1956 | INIT_LIST_HEAD(&conf->inactive_list); |
1957 | atomic_set(&conf->active_stripes, 0); | |
1958 | atomic_set(&conf->preread_active_stripes, 0); | |
1959 | ||
1da177e4 LT |
1960 | PRINTK("raid6: run(%s) called.\n", mdname(mddev)); |
1961 | ||
1962 | ITERATE_RDEV(mddev,rdev,tmp) { | |
1963 | raid_disk = rdev->raid_disk; | |
1964 | if (raid_disk >= mddev->raid_disks | |
1965 | || raid_disk < 0) | |
1966 | continue; | |
1967 | disk = conf->disks + raid_disk; | |
1968 | ||
1969 | disk->rdev = rdev; | |
1970 | ||
b2d444d7 | 1971 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
1972 | char b[BDEVNAME_SIZE]; |
1973 | printk(KERN_INFO "raid6: device %s operational as raid" | |
1974 | " disk %d\n", bdevname(rdev->bdev,b), | |
1975 | raid_disk); | |
1976 | conf->working_disks++; | |
1977 | } | |
1978 | } | |
1979 | ||
1980 | conf->raid_disks = mddev->raid_disks; | |
1981 | ||
1982 | /* | |
1983 | * 0 for a fully functional array, 1 or 2 for a degraded array. | |
1984 | */ | |
1985 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; | |
1986 | conf->mddev = mddev; | |
1987 | conf->chunk_size = mddev->chunk_size; | |
1988 | conf->level = mddev->level; | |
1989 | conf->algorithm = mddev->layout; | |
1990 | conf->max_nr_stripes = NR_STRIPES; | |
1991 | ||
1992 | /* device size must be a multiple of chunk size */ | |
1993 | mddev->size &= ~(mddev->chunk_size/1024 -1); | |
b1581566 | 1994 | mddev->resync_max_sectors = mddev->size << 1; |
1da177e4 LT |
1995 | |
1996 | if (conf->raid_disks < 4) { | |
1997 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", | |
1998 | mdname(mddev), conf->raid_disks); | |
1999 | goto abort; | |
2000 | } | |
2001 | if (!conf->chunk_size || conf->chunk_size % 4) { | |
2002 | printk(KERN_ERR "raid6: invalid chunk size %d for %s\n", | |
2003 | conf->chunk_size, mdname(mddev)); | |
2004 | goto abort; | |
2005 | } | |
2006 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | |
2007 | printk(KERN_ERR | |
2008 | "raid6: unsupported parity algorithm %d for %s\n", | |
2009 | conf->algorithm, mdname(mddev)); | |
2010 | goto abort; | |
2011 | } | |
2012 | if (mddev->degraded > 2) { | |
2013 | printk(KERN_ERR "raid6: not enough operational devices for %s" | |
2014 | " (%d/%d failed)\n", | |
2015 | mdname(mddev), conf->failed_disks, conf->raid_disks); | |
2016 | goto abort; | |
2017 | } | |
2018 | ||
1da177e4 LT |
2019 | if (mddev->degraded > 0 && |
2020 | mddev->recovery_cp != MaxSector) { | |
6ff8d8ec N |
2021 | if (mddev->ok_start_degraded) |
2022 | printk(KERN_WARNING "raid6: starting dirty degraded array:%s" | |
2023 | "- data corruption possible.\n", | |
2024 | mdname(mddev)); | |
2025 | else { | |
2026 | printk(KERN_ERR "raid6: cannot start dirty degraded array" | |
2027 | " for %s\n", mdname(mddev)); | |
2028 | goto abort; | |
2029 | } | |
1da177e4 | 2030 | } |
1da177e4 LT |
2031 | |
2032 | { | |
2033 | mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6"); | |
2034 | if (!mddev->thread) { | |
2035 | printk(KERN_ERR | |
2036 | "raid6: couldn't allocate thread for %s\n", | |
2037 | mdname(mddev)); | |
2038 | goto abort; | |
2039 | } | |
2040 | } | |
2041 | ||
2042 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + | |
2043 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; | |
2044 | if (grow_stripes(conf, conf->max_nr_stripes)) { | |
2045 | printk(KERN_ERR | |
2046 | "raid6: couldn't allocate %dkB for buffers\n", memory); | |
2047 | shrink_stripes(conf); | |
2048 | md_unregister_thread(mddev->thread); | |
2049 | goto abort; | |
2050 | } else | |
2051 | printk(KERN_INFO "raid6: allocated %dkB for %s\n", | |
2052 | memory, mdname(mddev)); | |
2053 | ||
2054 | if (mddev->degraded == 0) | |
2055 | printk(KERN_INFO "raid6: raid level %d set %s active with %d out of %d" | |
2056 | " devices, algorithm %d\n", conf->level, mdname(mddev), | |
2057 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | |
2058 | conf->algorithm); | |
2059 | else | |
2060 | printk(KERN_ALERT "raid6: raid level %d set %s active with %d" | |
2061 | " out of %d devices, algorithm %d\n", conf->level, | |
2062 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
2063 | mddev->raid_disks, conf->algorithm); | |
2064 | ||
2065 | print_raid6_conf(conf); | |
2066 | ||
2067 | /* read-ahead size must cover two whole stripes, which is | |
2068 | * 2 * (n-2) * chunksize where 'n' is the number of raid devices | |
2069 | */ | |
2070 | { | |
2071 | int stripe = (mddev->raid_disks-2) * mddev->chunk_size | |
2072 | / PAGE_CACHE_SIZE; | |
2073 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) | |
2074 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
2075 | } | |
2076 | ||
2077 | /* Ok, everything is just fine now */ | |
2078 | mddev->array_size = mddev->size * (mddev->raid_disks - 2); | |
7a5febe9 N |
2079 | |
2080 | mddev->queue->unplug_fn = raid6_unplug_device; | |
2081 | mddev->queue->issue_flush_fn = raid6_issue_flush; | |
1da177e4 LT |
2082 | return 0; |
2083 | abort: | |
2084 | if (conf) { | |
2085 | print_raid6_conf(conf); | |
ca65b73b N |
2086 | if (conf->spare_page) |
2087 | page_cache_release(conf->spare_page); | |
1da177e4 LT |
2088 | if (conf->stripe_hashtbl) |
2089 | free_pages((unsigned long) conf->stripe_hashtbl, | |
2090 | HASH_PAGES_ORDER); | |
2091 | kfree(conf); | |
2092 | } | |
2093 | mddev->private = NULL; | |
2094 | printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev)); | |
2095 | return -EIO; | |
2096 | } | |
2097 | ||
2098 | ||
2099 | ||
2100 | static int stop (mddev_t *mddev) | |
2101 | { | |
2102 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
2103 | ||
2104 | md_unregister_thread(mddev->thread); | |
2105 | mddev->thread = NULL; | |
2106 | shrink_stripes(conf); | |
2107 | free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); | |
2108 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
2109 | kfree(conf); | |
2110 | mddev->private = NULL; | |
2111 | return 0; | |
2112 | } | |
2113 | ||
2114 | #if RAID6_DUMPSTATE | |
2115 | static void print_sh (struct seq_file *seq, struct stripe_head *sh) | |
2116 | { | |
2117 | int i; | |
2118 | ||
2119 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", | |
2120 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | |
2121 | seq_printf(seq, "sh %llu, count %d.\n", | |
2122 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | |
2123 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); | |
2124 | for (i = 0; i < sh->raid_conf->raid_disks; i++) { | |
2125 | seq_printf(seq, "(cache%d: %p %ld) ", | |
2126 | i, sh->dev[i].page, sh->dev[i].flags); | |
2127 | } | |
2128 | seq_printf(seq, "\n"); | |
2129 | } | |
2130 | ||
2131 | static void printall (struct seq_file *seq, raid6_conf_t *conf) | |
2132 | { | |
2133 | struct stripe_head *sh; | |
2134 | int i; | |
2135 | ||
2136 | spin_lock_irq(&conf->device_lock); | |
2137 | for (i = 0; i < NR_HASH; i++) { | |
2138 | sh = conf->stripe_hashtbl[i]; | |
2139 | for (; sh; sh = sh->hash_next) { | |
2140 | if (sh->raid_conf != conf) | |
2141 | continue; | |
2142 | print_sh(seq, sh); | |
2143 | } | |
2144 | } | |
2145 | spin_unlock_irq(&conf->device_lock); | |
2146 | } | |
2147 | #endif | |
2148 | ||
2149 | static void status (struct seq_file *seq, mddev_t *mddev) | |
2150 | { | |
2151 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
2152 | int i; | |
2153 | ||
2154 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | |
2155 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); | |
2156 | for (i = 0; i < conf->raid_disks; i++) | |
2157 | seq_printf (seq, "%s", | |
2158 | conf->disks[i].rdev && | |
b2d444d7 | 2159 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
2160 | seq_printf (seq, "]"); |
2161 | #if RAID6_DUMPSTATE | |
2162 | seq_printf (seq, "\n"); | |
2163 | printall(seq, conf); | |
2164 | #endif | |
2165 | } | |
2166 | ||
2167 | static void print_raid6_conf (raid6_conf_t *conf) | |
2168 | { | |
2169 | int i; | |
2170 | struct disk_info *tmp; | |
2171 | ||
2172 | printk("RAID6 conf printout:\n"); | |
2173 | if (!conf) { | |
2174 | printk("(conf==NULL)\n"); | |
2175 | return; | |
2176 | } | |
2177 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, | |
2178 | conf->working_disks, conf->failed_disks); | |
2179 | ||
2180 | for (i = 0; i < conf->raid_disks; i++) { | |
2181 | char b[BDEVNAME_SIZE]; | |
2182 | tmp = conf->disks + i; | |
2183 | if (tmp->rdev) | |
2184 | printk(" disk %d, o:%d, dev:%s\n", | |
b2d444d7 | 2185 | i, !test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
2186 | bdevname(tmp->rdev->bdev,b)); |
2187 | } | |
2188 | } | |
2189 | ||
2190 | static int raid6_spare_active(mddev_t *mddev) | |
2191 | { | |
2192 | int i; | |
2193 | raid6_conf_t *conf = mddev->private; | |
2194 | struct disk_info *tmp; | |
2195 | ||
2196 | for (i = 0; i < conf->raid_disks; i++) { | |
2197 | tmp = conf->disks + i; | |
2198 | if (tmp->rdev | |
b2d444d7 N |
2199 | && !test_bit(Faulty, &tmp->rdev->flags) |
2200 | && !test_bit(In_sync, &tmp->rdev->flags)) { | |
1da177e4 LT |
2201 | mddev->degraded--; |
2202 | conf->failed_disks--; | |
2203 | conf->working_disks++; | |
b2d444d7 | 2204 | set_bit(In_sync, &tmp->rdev->flags); |
1da177e4 LT |
2205 | } |
2206 | } | |
2207 | print_raid6_conf(conf); | |
2208 | return 0; | |
2209 | } | |
2210 | ||
2211 | static int raid6_remove_disk(mddev_t *mddev, int number) | |
2212 | { | |
2213 | raid6_conf_t *conf = mddev->private; | |
2214 | int err = 0; | |
2215 | mdk_rdev_t *rdev; | |
2216 | struct disk_info *p = conf->disks + number; | |
2217 | ||
2218 | print_raid6_conf(conf); | |
2219 | rdev = p->rdev; | |
2220 | if (rdev) { | |
b2d444d7 | 2221 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
2222 | atomic_read(&rdev->nr_pending)) { |
2223 | err = -EBUSY; | |
2224 | goto abort; | |
2225 | } | |
2226 | p->rdev = NULL; | |
fbd568a3 | 2227 | synchronize_rcu(); |
1da177e4 LT |
2228 | if (atomic_read(&rdev->nr_pending)) { |
2229 | /* lost the race, try later */ | |
2230 | err = -EBUSY; | |
2231 | p->rdev = rdev; | |
2232 | } | |
2233 | } | |
2234 | ||
2235 | abort: | |
2236 | ||
2237 | print_raid6_conf(conf); | |
2238 | return err; | |
2239 | } | |
2240 | ||
2241 | static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
2242 | { | |
2243 | raid6_conf_t *conf = mddev->private; | |
2244 | int found = 0; | |
2245 | int disk; | |
2246 | struct disk_info *p; | |
2247 | ||
2248 | if (mddev->degraded > 2) | |
2249 | /* no point adding a device */ | |
2250 | return 0; | |
2251 | /* | |
6aea114a N |
2252 | * find the disk ... but prefer rdev->saved_raid_disk |
2253 | * if possible. | |
1da177e4 | 2254 | */ |
6aea114a N |
2255 | if (rdev->saved_raid_disk >= 0 && |
2256 | conf->disks[rdev->saved_raid_disk].rdev == NULL) | |
2257 | disk = rdev->saved_raid_disk; | |
2258 | else | |
2259 | disk = 0; | |
2260 | for ( ; disk < mddev->raid_disks; disk++) | |
1da177e4 | 2261 | if ((p=conf->disks + disk)->rdev == NULL) { |
b2d444d7 | 2262 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
2263 | rdev->raid_disk = disk; |
2264 | found = 1; | |
934ce7c8 N |
2265 | if (rdev->saved_raid_disk != disk) |
2266 | conf->fullsync = 1; | |
d6065f7b | 2267 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
2268 | break; |
2269 | } | |
2270 | print_raid6_conf(conf); | |
2271 | return found; | |
2272 | } | |
2273 | ||
2274 | static int raid6_resize(mddev_t *mddev, sector_t sectors) | |
2275 | { | |
2276 | /* no resync is happening, and there is enough space | |
2277 | * on all devices, so we can resize. | |
2278 | * We need to make sure resync covers any new space. | |
2279 | * If the array is shrinking we should possibly wait until | |
2280 | * any io in the removed space completes, but it hardly seems | |
2281 | * worth it. | |
2282 | */ | |
2283 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | |
2284 | mddev->array_size = (sectors * (mddev->raid_disks-2))>>1; | |
2285 | set_capacity(mddev->gendisk, mddev->array_size << 1); | |
2286 | mddev->changed = 1; | |
2287 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | |
2288 | mddev->recovery_cp = mddev->size << 1; | |
2289 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
2290 | } | |
2291 | mddev->size = sectors /2; | |
4b5c7ae8 | 2292 | mddev->resync_max_sectors = sectors; |
1da177e4 LT |
2293 | return 0; |
2294 | } | |
2295 | ||
934ce7c8 N |
2296 | static void raid6_quiesce(mddev_t *mddev, int state) |
2297 | { | |
2298 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
2299 | ||
2300 | switch(state) { | |
2301 | case 1: /* stop all writes */ | |
2302 | spin_lock_irq(&conf->device_lock); | |
2303 | conf->quiesce = 1; | |
2304 | wait_event_lock_irq(conf->wait_for_stripe, | |
2305 | atomic_read(&conf->active_stripes) == 0, | |
2306 | conf->device_lock, /* nothing */); | |
2307 | spin_unlock_irq(&conf->device_lock); | |
2308 | break; | |
2309 | ||
2310 | case 0: /* re-enable writes */ | |
2311 | spin_lock_irq(&conf->device_lock); | |
2312 | conf->quiesce = 0; | |
2313 | wake_up(&conf->wait_for_stripe); | |
2314 | spin_unlock_irq(&conf->device_lock); | |
2315 | break; | |
2316 | } | |
934ce7c8 | 2317 | } |
b15c2e57 | 2318 | |
1da177e4 LT |
2319 | static mdk_personality_t raid6_personality= |
2320 | { | |
2321 | .name = "raid6", | |
2322 | .owner = THIS_MODULE, | |
2323 | .make_request = make_request, | |
2324 | .run = run, | |
2325 | .stop = stop, | |
2326 | .status = status, | |
2327 | .error_handler = error, | |
2328 | .hot_add_disk = raid6_add_disk, | |
2329 | .hot_remove_disk= raid6_remove_disk, | |
2330 | .spare_active = raid6_spare_active, | |
2331 | .sync_request = sync_request, | |
2332 | .resize = raid6_resize, | |
934ce7c8 | 2333 | .quiesce = raid6_quiesce, |
1da177e4 LT |
2334 | }; |
2335 | ||
2336 | static int __init raid6_init (void) | |
2337 | { | |
2338 | int e; | |
2339 | ||
2340 | e = raid6_select_algo(); | |
2341 | if ( e ) | |
2342 | return e; | |
2343 | ||
2344 | return register_md_personality (RAID6, &raid6_personality); | |
2345 | } | |
2346 | ||
2347 | static void raid6_exit (void) | |
2348 | { | |
2349 | unregister_md_personality (RAID6); | |
2350 | } | |
2351 | ||
2352 | module_init(raid6_init); | |
2353 | module_exit(raid6_exit); | |
2354 | MODULE_LICENSE("GPL"); | |
2355 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ |