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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 | ||
370 | static int raid6_end_read_request (struct bio * bi, unsigned int bytes_done, | |
371 | int error) | |
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 | |
423 | } else { | |
424 | md_error(conf->mddev, conf->disks[i].rdev); | |
425 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); | |
426 | } | |
427 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
428 | #if 0 | |
429 | /* must restore b_page before unlocking buffer... */ | |
430 | if (sh->bh_page[i] != bh->b_page) { | |
431 | bh->b_page = sh->bh_page[i]; | |
432 | bh->b_data = page_address(bh->b_page); | |
433 | clear_buffer_uptodate(bh); | |
434 | } | |
435 | #endif | |
436 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
437 | set_bit(STRIPE_HANDLE, &sh->state); | |
438 | release_stripe(sh); | |
439 | return 0; | |
440 | } | |
441 | ||
442 | static int raid6_end_write_request (struct bio *bi, unsigned int bytes_done, | |
443 | int error) | |
444 | { | |
445 | struct stripe_head *sh = bi->bi_private; | |
446 | raid6_conf_t *conf = sh->raid_conf; | |
447 | int disks = conf->raid_disks, i; | |
448 | unsigned long flags; | |
449 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
450 | ||
451 | if (bi->bi_size) | |
452 | return 1; | |
453 | ||
454 | for (i=0 ; i<disks; i++) | |
455 | if (bi == &sh->dev[i].req) | |
456 | break; | |
457 | ||
458 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", | |
459 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
460 | uptodate); | |
461 | if (i == disks) { | |
462 | BUG(); | |
463 | return 0; | |
464 | } | |
465 | ||
466 | spin_lock_irqsave(&conf->device_lock, flags); | |
467 | if (!uptodate) | |
468 | md_error(conf->mddev, conf->disks[i].rdev); | |
469 | ||
470 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
471 | ||
472 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
473 | set_bit(STRIPE_HANDLE, &sh->state); | |
474 | __release_stripe(conf, sh); | |
475 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
476 | return 0; | |
477 | } | |
478 | ||
479 | ||
480 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | |
481 | ||
482 | static void raid6_build_block (struct stripe_head *sh, int i) | |
483 | { | |
484 | struct r5dev *dev = &sh->dev[i]; | |
485 | int pd_idx = sh->pd_idx; | |
486 | int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks); | |
487 | ||
488 | bio_init(&dev->req); | |
489 | dev->req.bi_io_vec = &dev->vec; | |
490 | dev->req.bi_vcnt++; | |
491 | dev->req.bi_max_vecs++; | |
492 | dev->vec.bv_page = dev->page; | |
493 | dev->vec.bv_len = STRIPE_SIZE; | |
494 | dev->vec.bv_offset = 0; | |
495 | ||
496 | dev->req.bi_sector = sh->sector; | |
497 | dev->req.bi_private = sh; | |
498 | ||
499 | dev->flags = 0; | |
500 | if (i != pd_idx && i != qd_idx) | |
501 | dev->sector = compute_blocknr(sh, i); | |
502 | } | |
503 | ||
504 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
505 | { | |
506 | char b[BDEVNAME_SIZE]; | |
507 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
508 | PRINTK("raid6: error called\n"); | |
509 | ||
510 | if (!rdev->faulty) { | |
511 | mddev->sb_dirty = 1; | |
512 | if (rdev->in_sync) { | |
513 | conf->working_disks--; | |
514 | mddev->degraded++; | |
515 | conf->failed_disks++; | |
516 | rdev->in_sync = 0; | |
517 | /* | |
518 | * if recovery was running, make sure it aborts. | |
519 | */ | |
520 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
521 | } | |
522 | rdev->faulty = 1; | |
523 | printk (KERN_ALERT | |
524 | "raid6: Disk failure on %s, disabling device." | |
525 | " Operation continuing on %d devices\n", | |
526 | bdevname(rdev->bdev,b), conf->working_disks); | |
527 | } | |
528 | } | |
529 | ||
530 | /* | |
531 | * Input: a 'big' sector number, | |
532 | * Output: index of the data and parity disk, and the sector # in them. | |
533 | */ | |
534 | static sector_t raid6_compute_sector(sector_t r_sector, unsigned int raid_disks, | |
535 | unsigned int data_disks, unsigned int * dd_idx, | |
536 | unsigned int * pd_idx, raid6_conf_t *conf) | |
537 | { | |
538 | long stripe; | |
539 | unsigned long chunk_number; | |
540 | unsigned int chunk_offset; | |
541 | sector_t new_sector; | |
542 | int sectors_per_chunk = conf->chunk_size >> 9; | |
543 | ||
544 | /* First compute the information on this sector */ | |
545 | ||
546 | /* | |
547 | * Compute the chunk number and the sector offset inside the chunk | |
548 | */ | |
549 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | |
550 | chunk_number = r_sector; | |
551 | if ( r_sector != chunk_number ) { | |
552 | printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n", | |
553 | (unsigned long long)r_sector, (unsigned long)chunk_number); | |
554 | BUG(); | |
555 | } | |
556 | ||
557 | /* | |
558 | * Compute the stripe number | |
559 | */ | |
560 | stripe = chunk_number / data_disks; | |
561 | ||
562 | /* | |
563 | * Compute the data disk and parity disk indexes inside the stripe | |
564 | */ | |
565 | *dd_idx = chunk_number % data_disks; | |
566 | ||
567 | /* | |
568 | * Select the parity disk based on the user selected algorithm. | |
569 | */ | |
570 | ||
571 | /**** FIX THIS ****/ | |
572 | switch (conf->algorithm) { | |
573 | case ALGORITHM_LEFT_ASYMMETRIC: | |
574 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
575 | if (*pd_idx == raid_disks-1) | |
576 | (*dd_idx)++; /* Q D D D P */ | |
577 | else if (*dd_idx >= *pd_idx) | |
578 | (*dd_idx) += 2; /* D D P Q D */ | |
579 | break; | |
580 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
581 | *pd_idx = stripe % raid_disks; | |
582 | if (*pd_idx == raid_disks-1) | |
583 | (*dd_idx)++; /* Q D D D P */ | |
584 | else if (*dd_idx >= *pd_idx) | |
585 | (*dd_idx) += 2; /* D D P Q D */ | |
586 | break; | |
587 | case ALGORITHM_LEFT_SYMMETRIC: | |
588 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | |
589 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
590 | break; | |
591 | case ALGORITHM_RIGHT_SYMMETRIC: | |
592 | *pd_idx = stripe % raid_disks; | |
593 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | |
594 | break; | |
595 | default: | |
596 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
597 | conf->algorithm); | |
598 | } | |
599 | ||
600 | PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n", | |
601 | chunk_number, *pd_idx, *dd_idx); | |
602 | ||
603 | /* | |
604 | * Finally, compute the new sector number | |
605 | */ | |
606 | new_sector = (sector_t) stripe * sectors_per_chunk + chunk_offset; | |
607 | return new_sector; | |
608 | } | |
609 | ||
610 | ||
611 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | |
612 | { | |
613 | raid6_conf_t *conf = sh->raid_conf; | |
614 | int raid_disks = conf->raid_disks, data_disks = raid_disks - 2; | |
615 | sector_t new_sector = sh->sector, check; | |
616 | int sectors_per_chunk = conf->chunk_size >> 9; | |
617 | sector_t stripe; | |
618 | int chunk_offset; | |
619 | int chunk_number, dummy1, dummy2, dd_idx = i; | |
620 | sector_t r_sector; | |
621 | int i0 = i; | |
622 | ||
623 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | |
624 | stripe = new_sector; | |
625 | if ( new_sector != stripe ) { | |
626 | printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n", | |
627 | (unsigned long long)new_sector, (unsigned long)stripe); | |
628 | BUG(); | |
629 | } | |
630 | ||
631 | switch (conf->algorithm) { | |
632 | case ALGORITHM_LEFT_ASYMMETRIC: | |
633 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
634 | if (sh->pd_idx == raid_disks-1) | |
635 | i--; /* Q D D D P */ | |
636 | else if (i > sh->pd_idx) | |
637 | i -= 2; /* D D P Q D */ | |
638 | break; | |
639 | case ALGORITHM_LEFT_SYMMETRIC: | |
640 | case ALGORITHM_RIGHT_SYMMETRIC: | |
641 | if (sh->pd_idx == raid_disks-1) | |
642 | i--; /* Q D D D P */ | |
643 | else { | |
644 | /* D D P Q D */ | |
645 | if (i < sh->pd_idx) | |
646 | i += raid_disks; | |
647 | i -= (sh->pd_idx + 2); | |
648 | } | |
649 | break; | |
650 | default: | |
651 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | |
652 | conf->algorithm); | |
653 | } | |
654 | ||
655 | PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i); | |
656 | ||
657 | chunk_number = stripe * data_disks + i; | |
658 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | |
659 | ||
660 | check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | |
661 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | |
662 | printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n"); | |
663 | return 0; | |
664 | } | |
665 | return r_sector; | |
666 | } | |
667 | ||
668 | ||
669 | ||
670 | /* | |
671 | * Copy data between a page in the stripe cache, and one or more bion | |
672 | * The page could align with the middle of the bio, or there could be | |
673 | * several bion, each with several bio_vecs, which cover part of the page | |
674 | * Multiple bion are linked together on bi_next. There may be extras | |
675 | * at the end of this list. We ignore them. | |
676 | */ | |
677 | static void copy_data(int frombio, struct bio *bio, | |
678 | struct page *page, | |
679 | sector_t sector) | |
680 | { | |
681 | char *pa = page_address(page); | |
682 | struct bio_vec *bvl; | |
683 | int i; | |
684 | int page_offset; | |
685 | ||
686 | if (bio->bi_sector >= sector) | |
687 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
688 | else | |
689 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
690 | bio_for_each_segment(bvl, bio, i) { | |
691 | int len = bio_iovec_idx(bio,i)->bv_len; | |
692 | int clen; | |
693 | int b_offset = 0; | |
694 | ||
695 | if (page_offset < 0) { | |
696 | b_offset = -page_offset; | |
697 | page_offset += b_offset; | |
698 | len -= b_offset; | |
699 | } | |
700 | ||
701 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
702 | clen = STRIPE_SIZE - page_offset; | |
703 | else clen = len; | |
704 | ||
705 | if (clen > 0) { | |
706 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | |
707 | if (frombio) | |
708 | memcpy(pa+page_offset, ba+b_offset, clen); | |
709 | else | |
710 | memcpy(ba+b_offset, pa+page_offset, clen); | |
711 | __bio_kunmap_atomic(ba, KM_USER0); | |
712 | } | |
713 | if (clen < len) /* hit end of page */ | |
714 | break; | |
715 | page_offset += len; | |
716 | } | |
717 | } | |
718 | ||
719 | #define check_xor() do { \ | |
720 | if (count == MAX_XOR_BLOCKS) { \ | |
721 | xor_block(count, STRIPE_SIZE, ptr); \ | |
722 | count = 1; \ | |
723 | } \ | |
724 | } while(0) | |
725 | ||
726 | /* Compute P and Q syndromes */ | |
727 | static void compute_parity(struct stripe_head *sh, int method) | |
728 | { | |
729 | raid6_conf_t *conf = sh->raid_conf; | |
730 | int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; | |
731 | struct bio *chosen; | |
732 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
733 | void *ptrs[disks]; | |
734 | ||
735 | qd_idx = raid6_next_disk(pd_idx, disks); | |
736 | d0_idx = raid6_next_disk(qd_idx, disks); | |
737 | ||
738 | PRINTK("compute_parity, stripe %llu, method %d\n", | |
739 | (unsigned long long)sh->sector, method); | |
740 | ||
741 | switch(method) { | |
742 | case READ_MODIFY_WRITE: | |
743 | BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ | |
744 | case RECONSTRUCT_WRITE: | |
745 | for (i= disks; i-- ;) | |
746 | if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { | |
747 | chosen = sh->dev[i].towrite; | |
748 | sh->dev[i].towrite = NULL; | |
749 | ||
750 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
751 | wake_up(&conf->wait_for_overlap); | |
752 | ||
753 | if (sh->dev[i].written) BUG(); | |
754 | sh->dev[i].written = chosen; | |
755 | } | |
756 | break; | |
757 | case CHECK_PARITY: | |
758 | BUG(); /* Not implemented yet */ | |
759 | } | |
760 | ||
761 | for (i = disks; i--;) | |
762 | if (sh->dev[i].written) { | |
763 | sector_t sector = sh->dev[i].sector; | |
764 | struct bio *wbi = sh->dev[i].written; | |
765 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | |
766 | copy_data(1, wbi, sh->dev[i].page, sector); | |
767 | wbi = r5_next_bio(wbi, sector); | |
768 | } | |
769 | ||
770 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
771 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
772 | } | |
773 | ||
774 | // switch(method) { | |
775 | // case RECONSTRUCT_WRITE: | |
776 | // case CHECK_PARITY: | |
777 | // case UPDATE_PARITY: | |
778 | /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ | |
779 | /* FIX: Is this ordering of drives even remotely optimal? */ | |
780 | count = 0; | |
781 | i = d0_idx; | |
782 | do { | |
783 | ptrs[count++] = page_address(sh->dev[i].page); | |
784 | if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
785 | printk("block %d/%d not uptodate on parity calc\n", i,count); | |
786 | i = raid6_next_disk(i, disks); | |
787 | } while ( i != d0_idx ); | |
788 | // break; | |
789 | // } | |
790 | ||
791 | raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); | |
792 | ||
793 | switch(method) { | |
794 | case RECONSTRUCT_WRITE: | |
795 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
796 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
797 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
798 | set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); | |
799 | break; | |
800 | case UPDATE_PARITY: | |
801 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
802 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | |
803 | break; | |
804 | } | |
805 | } | |
806 | ||
807 | /* Compute one missing block */ | |
808 | static void compute_block_1(struct stripe_head *sh, int dd_idx) | |
809 | { | |
810 | raid6_conf_t *conf = sh->raid_conf; | |
811 | int i, count, disks = conf->raid_disks; | |
812 | void *ptr[MAX_XOR_BLOCKS], *p; | |
813 | int pd_idx = sh->pd_idx; | |
814 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
815 | ||
816 | PRINTK("compute_block_1, stripe %llu, idx %d\n", | |
817 | (unsigned long long)sh->sector, dd_idx); | |
818 | ||
819 | if ( dd_idx == qd_idx ) { | |
820 | /* We're actually computing the Q drive */ | |
821 | compute_parity(sh, UPDATE_PARITY); | |
822 | } else { | |
823 | ptr[0] = page_address(sh->dev[dd_idx].page); | |
824 | memset(ptr[0], 0, STRIPE_SIZE); | |
825 | count = 1; | |
826 | for (i = disks ; i--; ) { | |
827 | if (i == dd_idx || i == qd_idx) | |
828 | continue; | |
829 | p = page_address(sh->dev[i].page); | |
830 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
831 | ptr[count++] = p; | |
832 | else | |
833 | printk("compute_block() %d, stripe %llu, %d" | |
834 | " not present\n", dd_idx, | |
835 | (unsigned long long)sh->sector, i); | |
836 | ||
837 | check_xor(); | |
838 | } | |
839 | if (count != 1) | |
840 | xor_block(count, STRIPE_SIZE, ptr); | |
841 | set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
842 | } | |
843 | } | |
844 | ||
845 | /* Compute two missing blocks */ | |
846 | static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) | |
847 | { | |
848 | raid6_conf_t *conf = sh->raid_conf; | |
849 | int i, count, disks = conf->raid_disks; | |
850 | int pd_idx = sh->pd_idx; | |
851 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
852 | int d0_idx = raid6_next_disk(qd_idx, disks); | |
853 | int faila, failb; | |
854 | ||
855 | /* faila and failb are disk numbers relative to d0_idx */ | |
856 | /* pd_idx become disks-2 and qd_idx become disks-1 */ | |
857 | faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; | |
858 | failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; | |
859 | ||
860 | BUG_ON(faila == failb); | |
861 | if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } | |
862 | ||
863 | PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", | |
864 | (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); | |
865 | ||
866 | if ( failb == disks-1 ) { | |
867 | /* Q disk is one of the missing disks */ | |
868 | if ( faila == disks-2 ) { | |
869 | /* Missing P+Q, just recompute */ | |
870 | compute_parity(sh, UPDATE_PARITY); | |
871 | return; | |
872 | } else { | |
873 | /* We're missing D+Q; recompute D from P */ | |
874 | compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1); | |
875 | compute_parity(sh, UPDATE_PARITY); /* Is this necessary? */ | |
876 | return; | |
877 | } | |
878 | } | |
879 | ||
880 | /* We're missing D+P or D+D; build pointer table */ | |
881 | { | |
882 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | |
883 | void *ptrs[disks]; | |
884 | ||
885 | count = 0; | |
886 | i = d0_idx; | |
887 | do { | |
888 | ptrs[count++] = page_address(sh->dev[i].page); | |
889 | i = raid6_next_disk(i, disks); | |
890 | if (i != dd_idx1 && i != dd_idx2 && | |
891 | !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
892 | printk("compute_2 with missing block %d/%d\n", count, i); | |
893 | } while ( i != d0_idx ); | |
894 | ||
895 | if ( failb == disks-2 ) { | |
896 | /* We're missing D+P. */ | |
897 | raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); | |
898 | } else { | |
899 | /* We're missing D+D. */ | |
900 | raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); | |
901 | } | |
902 | ||
903 | /* Both the above update both missing blocks */ | |
904 | set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); | |
905 | set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); | |
906 | } | |
907 | } | |
908 | ||
909 | ||
910 | /* | |
911 | * Each stripe/dev can have one or more bion attached. | |
912 | * toread/towrite point to the first in a chain. | |
913 | * The bi_next chain must be in order. | |
914 | */ | |
915 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | |
916 | { | |
917 | struct bio **bip; | |
918 | raid6_conf_t *conf = sh->raid_conf; | |
934ce7c8 | 919 | int firstwrite=0; |
1da177e4 LT |
920 | |
921 | PRINTK("adding bh b#%llu to stripe s#%llu\n", | |
922 | (unsigned long long)bi->bi_sector, | |
923 | (unsigned long long)sh->sector); | |
924 | ||
925 | ||
926 | spin_lock(&sh->lock); | |
927 | spin_lock_irq(&conf->device_lock); | |
934ce7c8 | 928 | if (forwrite) { |
1da177e4 | 929 | bip = &sh->dev[dd_idx].towrite; |
934ce7c8 N |
930 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
931 | firstwrite = 1; | |
932 | } else | |
1da177e4 LT |
933 | bip = &sh->dev[dd_idx].toread; |
934 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | |
935 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | |
936 | goto overlap; | |
937 | bip = &(*bip)->bi_next; | |
938 | } | |
939 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | |
940 | goto overlap; | |
941 | ||
942 | if (*bip && bi->bi_next && (*bip) != bi->bi_next) | |
943 | BUG(); | |
944 | if (*bip) | |
945 | bi->bi_next = *bip; | |
946 | *bip = bi; | |
947 | bi->bi_phys_segments ++; | |
948 | spin_unlock_irq(&conf->device_lock); | |
949 | spin_unlock(&sh->lock); | |
950 | ||
951 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", | |
952 | (unsigned long long)bi->bi_sector, | |
953 | (unsigned long long)sh->sector, dd_idx); | |
954 | ||
934ce7c8 N |
955 | if (conf->mddev->bitmap && firstwrite) { |
956 | sh->bm_seq = conf->seq_write; | |
957 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | |
958 | STRIPE_SECTORS, 0); | |
959 | set_bit(STRIPE_BIT_DELAY, &sh->state); | |
960 | } | |
961 | ||
1da177e4 LT |
962 | if (forwrite) { |
963 | /* check if page is covered */ | |
964 | sector_t sector = sh->dev[dd_idx].sector; | |
965 | for (bi=sh->dev[dd_idx].towrite; | |
966 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | |
967 | bi && bi->bi_sector <= sector; | |
968 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | |
969 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | |
970 | sector = bi->bi_sector + (bi->bi_size>>9); | |
971 | } | |
972 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | |
973 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | |
974 | } | |
975 | return 1; | |
976 | ||
977 | overlap: | |
978 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | |
979 | spin_unlock_irq(&conf->device_lock); | |
980 | spin_unlock(&sh->lock); | |
981 | return 0; | |
982 | } | |
983 | ||
984 | ||
985 | /* | |
986 | * handle_stripe - do things to a stripe. | |
987 | * | |
988 | * We lock the stripe and then examine the state of various bits | |
989 | * to see what needs to be done. | |
990 | * Possible results: | |
991 | * return some read request which now have data | |
992 | * return some write requests which are safely on disc | |
993 | * schedule a read on some buffers | |
994 | * schedule a write of some buffers | |
995 | * return confirmation of parity correctness | |
996 | * | |
997 | * Parity calculations are done inside the stripe lock | |
998 | * buffers are taken off read_list or write_list, and bh_cache buffers | |
999 | * get BH_Lock set before the stripe lock is released. | |
1000 | * | |
1001 | */ | |
1002 | ||
1003 | static void handle_stripe(struct stripe_head *sh) | |
1004 | { | |
1005 | raid6_conf_t *conf = sh->raid_conf; | |
1006 | int disks = conf->raid_disks; | |
1007 | struct bio *return_bi= NULL; | |
1008 | struct bio *bi; | |
1009 | int i; | |
1010 | int syncing; | |
1011 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; | |
1012 | int non_overwrite = 0; | |
1013 | int failed_num[2] = {0, 0}; | |
1014 | struct r5dev *dev, *pdev, *qdev; | |
1015 | int pd_idx = sh->pd_idx; | |
1016 | int qd_idx = raid6_next_disk(pd_idx, disks); | |
1017 | int p_failed, q_failed; | |
1018 | ||
1019 | PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", | |
1020 | (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), | |
1021 | pd_idx, qd_idx); | |
1022 | ||
1023 | spin_lock(&sh->lock); | |
1024 | clear_bit(STRIPE_HANDLE, &sh->state); | |
1025 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1026 | ||
1027 | syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
1028 | /* Now to look around and see what can be done */ | |
1029 | ||
1030 | for (i=disks; i--; ) { | |
1031 | mdk_rdev_t *rdev; | |
1032 | dev = &sh->dev[i]; | |
1033 | clear_bit(R5_Insync, &dev->flags); | |
1034 | clear_bit(R5_Syncio, &dev->flags); | |
1035 | ||
1036 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", | |
1037 | i, dev->flags, dev->toread, dev->towrite, dev->written); | |
1038 | /* maybe we can reply to a read */ | |
1039 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | |
1040 | struct bio *rbi, *rbi2; | |
1041 | PRINTK("Return read for disc %d\n", i); | |
1042 | spin_lock_irq(&conf->device_lock); | |
1043 | rbi = dev->toread; | |
1044 | dev->toread = NULL; | |
1045 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
1046 | wake_up(&conf->wait_for_overlap); | |
1047 | spin_unlock_irq(&conf->device_lock); | |
1048 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1049 | copy_data(0, rbi, dev->page, dev->sector); | |
1050 | rbi2 = r5_next_bio(rbi, dev->sector); | |
1051 | spin_lock_irq(&conf->device_lock); | |
1052 | if (--rbi->bi_phys_segments == 0) { | |
1053 | rbi->bi_next = return_bi; | |
1054 | return_bi = rbi; | |
1055 | } | |
1056 | spin_unlock_irq(&conf->device_lock); | |
1057 | rbi = rbi2; | |
1058 | } | |
1059 | } | |
1060 | ||
1061 | /* now count some things */ | |
1062 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; | |
1063 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; | |
1064 | ||
1065 | ||
1066 | if (dev->toread) to_read++; | |
1067 | if (dev->towrite) { | |
1068 | to_write++; | |
1069 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
1070 | non_overwrite++; | |
1071 | } | |
1072 | if (dev->written) written++; | |
1073 | rdev = conf->disks[i].rdev; /* FIXME, should I be looking rdev */ | |
1074 | if (!rdev || !rdev->in_sync) { | |
1075 | if ( failed < 2 ) | |
1076 | failed_num[failed] = i; | |
1077 | failed++; | |
1078 | } else | |
1079 | set_bit(R5_Insync, &dev->flags); | |
1080 | } | |
1081 | PRINTK("locked=%d uptodate=%d to_read=%d" | |
1082 | " to_write=%d failed=%d failed_num=%d,%d\n", | |
1083 | locked, uptodate, to_read, to_write, failed, | |
1084 | failed_num[0], failed_num[1]); | |
1085 | /* check if the array has lost >2 devices and, if so, some requests might | |
1086 | * need to be failed | |
1087 | */ | |
1088 | if (failed > 2 && to_read+to_write+written) { | |
1da177e4 | 1089 | for (i=disks; i--; ) { |
934ce7c8 N |
1090 | int bitmap_end = 0; |
1091 | spin_lock_irq(&conf->device_lock); | |
1da177e4 LT |
1092 | /* fail all writes first */ |
1093 | bi = sh->dev[i].towrite; | |
1094 | sh->dev[i].towrite = NULL; | |
934ce7c8 | 1095 | if (bi) { to_write--; bitmap_end = 1; } |
1da177e4 LT |
1096 | |
1097 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1098 | wake_up(&conf->wait_for_overlap); | |
1099 | ||
1100 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1101 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1102 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1103 | if (--bi->bi_phys_segments == 0) { | |
1104 | md_write_end(conf->mddev); | |
1105 | bi->bi_next = return_bi; | |
1106 | return_bi = bi; | |
1107 | } | |
1108 | bi = nextbi; | |
1109 | } | |
1110 | /* and fail all 'written' */ | |
1111 | bi = sh->dev[i].written; | |
1112 | sh->dev[i].written = NULL; | |
934ce7c8 | 1113 | if (bi) bitmap_end = 1; |
1da177e4 LT |
1114 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { |
1115 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | |
1116 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1117 | if (--bi->bi_phys_segments == 0) { | |
1118 | md_write_end(conf->mddev); | |
1119 | bi->bi_next = return_bi; | |
1120 | return_bi = bi; | |
1121 | } | |
1122 | bi = bi2; | |
1123 | } | |
1124 | ||
1125 | /* fail any reads if this device is non-operational */ | |
1126 | if (!test_bit(R5_Insync, &sh->dev[i].flags)) { | |
1127 | bi = sh->dev[i].toread; | |
1128 | sh->dev[i].toread = NULL; | |
1129 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1130 | wake_up(&conf->wait_for_overlap); | |
1131 | if (bi) to_read--; | |
1132 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1133 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1134 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1135 | if (--bi->bi_phys_segments == 0) { | |
1136 | bi->bi_next = return_bi; | |
1137 | return_bi = bi; | |
1138 | } | |
1139 | bi = nextbi; | |
1140 | } | |
1141 | } | |
934ce7c8 N |
1142 | spin_unlock_irq(&conf->device_lock); |
1143 | if (bitmap_end) | |
1144 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1145 | STRIPE_SECTORS, 0, 0); | |
1da177e4 | 1146 | } |
1da177e4 LT |
1147 | } |
1148 | if (failed > 2 && syncing) { | |
1149 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
1150 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1151 | syncing = 0; | |
1152 | } | |
1153 | ||
1154 | /* | |
1155 | * might be able to return some write requests if the parity blocks | |
1156 | * are safe, or on a failed drive | |
1157 | */ | |
1158 | pdev = &sh->dev[pd_idx]; | |
1159 | p_failed = (failed >= 1 && failed_num[0] == pd_idx) | |
1160 | || (failed >= 2 && failed_num[1] == pd_idx); | |
1161 | qdev = &sh->dev[qd_idx]; | |
1162 | q_failed = (failed >= 1 && failed_num[0] == qd_idx) | |
1163 | || (failed >= 2 && failed_num[1] == qd_idx); | |
1164 | ||
1165 | if ( written && | |
1166 | ( p_failed || ((test_bit(R5_Insync, &pdev->flags) | |
1167 | && !test_bit(R5_LOCKED, &pdev->flags) | |
1168 | && test_bit(R5_UPTODATE, &pdev->flags))) ) && | |
1169 | ( q_failed || ((test_bit(R5_Insync, &qdev->flags) | |
1170 | && !test_bit(R5_LOCKED, &qdev->flags) | |
1171 | && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { | |
1172 | /* any written block on an uptodate or failed drive can be | |
1173 | * returned. Note that if we 'wrote' to a failed drive, | |
1174 | * it will be UPTODATE, but never LOCKED, so we don't need | |
1175 | * to test 'failed' directly. | |
1176 | */ | |
1177 | for (i=disks; i--; ) | |
1178 | if (sh->dev[i].written) { | |
1179 | dev = &sh->dev[i]; | |
1180 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1181 | test_bit(R5_UPTODATE, &dev->flags) ) { | |
1182 | /* We can return any write requests */ | |
934ce7c8 | 1183 | int bitmap_end = 0; |
1da177e4 LT |
1184 | struct bio *wbi, *wbi2; |
1185 | PRINTK("Return write for stripe %llu disc %d\n", | |
1186 | (unsigned long long)sh->sector, i); | |
1187 | spin_lock_irq(&conf->device_lock); | |
1188 | wbi = dev->written; | |
1189 | dev->written = NULL; | |
1190 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1191 | wbi2 = r5_next_bio(wbi, dev->sector); | |
1192 | if (--wbi->bi_phys_segments == 0) { | |
1193 | md_write_end(conf->mddev); | |
1194 | wbi->bi_next = return_bi; | |
1195 | return_bi = wbi; | |
1196 | } | |
1197 | wbi = wbi2; | |
1198 | } | |
934ce7c8 N |
1199 | if (dev->towrite == NULL) |
1200 | bitmap_end = 1; | |
1da177e4 | 1201 | spin_unlock_irq(&conf->device_lock); |
934ce7c8 N |
1202 | if (bitmap_end) |
1203 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1204 | STRIPE_SECTORS, | |
1205 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); | |
1da177e4 LT |
1206 | } |
1207 | } | |
1208 | } | |
1209 | ||
1210 | /* Now we might consider reading some blocks, either to check/generate | |
1211 | * parity, or to satisfy requests | |
1212 | * or to load a block that is being partially written. | |
1213 | */ | |
1214 | if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { | |
1215 | for (i=disks; i--;) { | |
1216 | dev = &sh->dev[i]; | |
1217 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1218 | (dev->toread || | |
1219 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1220 | syncing || | |
1221 | (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || | |
1222 | (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) | |
1223 | ) | |
1224 | ) { | |
1225 | /* we would like to get this block, possibly | |
1226 | * by computing it, but we might not be able to | |
1227 | */ | |
1228 | if (uptodate == disks-1) { | |
1229 | PRINTK("Computing stripe %llu block %d\n", | |
1230 | (unsigned long long)sh->sector, i); | |
1231 | compute_block_1(sh, i); | |
1232 | uptodate++; | |
1233 | } else if ( uptodate == disks-2 && failed >= 2 ) { | |
1234 | /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ | |
1235 | int other; | |
1236 | for (other=disks; other--;) { | |
1237 | if ( other == i ) | |
1238 | continue; | |
1239 | if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) | |
1240 | break; | |
1241 | } | |
1242 | BUG_ON(other < 0); | |
1243 | PRINTK("Computing stripe %llu blocks %d,%d\n", | |
1244 | (unsigned long long)sh->sector, i, other); | |
1245 | compute_block_2(sh, i, other); | |
1246 | uptodate += 2; | |
1247 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1248 | set_bit(R5_LOCKED, &dev->flags); | |
1249 | set_bit(R5_Wantread, &dev->flags); | |
1250 | #if 0 | |
1251 | /* if I am just reading this block and we don't have | |
1252 | a failed drive, or any pending writes then sidestep the cache */ | |
1253 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && | |
1254 | ! syncing && !failed && !to_write) { | |
1255 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; | |
1256 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; | |
1257 | } | |
1258 | #endif | |
1259 | locked++; | |
1260 | PRINTK("Reading block %d (sync=%d)\n", | |
1261 | i, syncing); | |
1262 | if (syncing) | |
1263 | md_sync_acct(conf->disks[i].rdev->bdev, | |
1264 | STRIPE_SECTORS); | |
1265 | } | |
1266 | } | |
1267 | } | |
1268 | set_bit(STRIPE_HANDLE, &sh->state); | |
1269 | } | |
1270 | ||
1271 | /* now to consider writing and what else, if anything should be read */ | |
1272 | if (to_write) { | |
1273 | int rcw=0, must_compute=0; | |
1274 | for (i=disks ; i--;) { | |
1275 | dev = &sh->dev[i]; | |
1276 | /* Would I have to read this buffer for reconstruct_write */ | |
1277 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
1278 | && i != pd_idx && i != qd_idx | |
1279 | && (!test_bit(R5_LOCKED, &dev->flags) | |
1280 | #if 0 | |
1281 | || sh->bh_page[i] != bh->b_page | |
1282 | #endif | |
1283 | ) && | |
1284 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1285 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
1286 | else { | |
1287 | PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); | |
1288 | must_compute++; | |
1289 | } | |
1290 | } | |
1291 | } | |
1292 | PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", | |
1293 | (unsigned long long)sh->sector, rcw, must_compute); | |
1294 | set_bit(STRIPE_HANDLE, &sh->state); | |
1295 | ||
1296 | if (rcw > 0) | |
1297 | /* want reconstruct write, but need to get some data */ | |
1298 | for (i=disks; i--;) { | |
1299 | dev = &sh->dev[i]; | |
1300 | if (!test_bit(R5_OVERWRITE, &dev->flags) | |
1301 | && !(failed == 0 && (i == pd_idx || i == qd_idx)) | |
1302 | && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1303 | test_bit(R5_Insync, &dev->flags)) { | |
1304 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1305 | { | |
1306 | PRINTK("Read_old stripe %llu block %d for Reconstruct\n", | |
1307 | (unsigned long long)sh->sector, i); | |
1308 | set_bit(R5_LOCKED, &dev->flags); | |
1309 | set_bit(R5_Wantread, &dev->flags); | |
1310 | locked++; | |
1311 | } else { | |
1312 | PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", | |
1313 | (unsigned long long)sh->sector, i); | |
1314 | set_bit(STRIPE_DELAYED, &sh->state); | |
1315 | set_bit(STRIPE_HANDLE, &sh->state); | |
1316 | } | |
1317 | } | |
1318 | } | |
1319 | /* now if nothing is locked, and if we have enough data, we can start a write request */ | |
934ce7c8 N |
1320 | if (locked == 0 && rcw == 0 && |
1321 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | |
1da177e4 LT |
1322 | if ( must_compute > 0 ) { |
1323 | /* We have failed blocks and need to compute them */ | |
1324 | switch ( failed ) { | |
1325 | case 0: BUG(); | |
1326 | case 1: compute_block_1(sh, failed_num[0]); break; | |
1327 | case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; | |
1328 | default: BUG(); /* This request should have been failed? */ | |
1329 | } | |
1330 | } | |
1331 | ||
1332 | PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); | |
1333 | compute_parity(sh, RECONSTRUCT_WRITE); | |
1334 | /* now every locked buffer is ready to be written */ | |
1335 | for (i=disks; i--;) | |
1336 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | |
1337 | PRINTK("Writing stripe %llu block %d\n", | |
1338 | (unsigned long long)sh->sector, i); | |
1339 | locked++; | |
1340 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
1341 | #if 0 /**** FIX: I don't understand the logic here... ****/ | |
1342 | if (!test_bit(R5_Insync, &sh->dev[i].flags) | |
1343 | || ((i==pd_idx || i==qd_idx) && failed == 0)) /* FIX? */ | |
1344 | set_bit(STRIPE_INSYNC, &sh->state); | |
1345 | #endif | |
1346 | } | |
1347 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
1348 | atomic_dec(&conf->preread_active_stripes); | |
1349 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
1350 | md_wakeup_thread(conf->mddev->thread); | |
1351 | } | |
1352 | } | |
1353 | } | |
1354 | ||
1355 | /* maybe we need to check and possibly fix the parity for this stripe | |
1356 | * Any reads will already have been scheduled, so we just see if enough data | |
1357 | * is available | |
1358 | */ | |
1359 | if (syncing && locked == 0 && | |
1360 | !test_bit(STRIPE_INSYNC, &sh->state) && failed <= 2) { | |
1361 | set_bit(STRIPE_HANDLE, &sh->state); | |
1362 | #if 0 /* RAID-6: Don't support CHECK PARITY yet */ | |
1363 | if (failed == 0) { | |
1364 | char *pagea; | |
1365 | if (uptodate != disks) | |
1366 | BUG(); | |
1367 | compute_parity(sh, CHECK_PARITY); | |
1368 | uptodate--; | |
1369 | pagea = page_address(sh->dev[pd_idx].page); | |
1370 | if ((*(u32*)pagea) == 0 && | |
1371 | !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) { | |
1372 | /* parity is correct (on disc, not in buffer any more) */ | |
1373 | set_bit(STRIPE_INSYNC, &sh->state); | |
1374 | } | |
1375 | } | |
1376 | #endif | |
1377 | if (!test_bit(STRIPE_INSYNC, &sh->state)) { | |
1378 | int failed_needupdate[2]; | |
1379 | struct r5dev *adev, *bdev; | |
1380 | ||
1381 | if ( failed < 1 ) | |
1382 | failed_num[0] = pd_idx; | |
1383 | if ( failed < 2 ) | |
1384 | failed_num[1] = (failed_num[0] == qd_idx) ? pd_idx : qd_idx; | |
1385 | ||
1386 | failed_needupdate[0] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[0]].flags); | |
1387 | failed_needupdate[1] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[1]].flags); | |
1388 | ||
1389 | PRINTK("sync: failed=%d num=%d,%d fnu=%u%u\n", | |
1390 | failed, failed_num[0], failed_num[1], failed_needupdate[0], failed_needupdate[1]); | |
1391 | ||
1392 | #if 0 /* RAID-6: This code seems to require that CHECK_PARITY destroys the uptodateness of the parity */ | |
1393 | /* should be able to compute the missing block(s) and write to spare */ | |
1394 | if ( failed_needupdate[0] ^ failed_needupdate[1] ) { | |
1395 | if (uptodate+1 != disks) | |
1396 | BUG(); | |
1397 | compute_block_1(sh, failed_needupdate[0] ? failed_num[0] : failed_num[1]); | |
1398 | uptodate++; | |
1399 | } else if ( failed_needupdate[0] & failed_needupdate[1] ) { | |
1400 | if (uptodate+2 != disks) | |
1401 | BUG(); | |
1402 | compute_block_2(sh, failed_num[0], failed_num[1]); | |
1403 | uptodate += 2; | |
1404 | } | |
1405 | #else | |
1406 | compute_block_2(sh, failed_num[0], failed_num[1]); | |
1407 | uptodate += failed_needupdate[0] + failed_needupdate[1]; | |
1408 | #endif | |
1409 | ||
1410 | if (uptodate != disks) | |
1411 | BUG(); | |
1412 | ||
1413 | PRINTK("Marking for sync stripe %llu blocks %d,%d\n", | |
1414 | (unsigned long long)sh->sector, failed_num[0], failed_num[1]); | |
1415 | ||
1416 | /**** FIX: Should we really do both of these unconditionally? ****/ | |
1417 | adev = &sh->dev[failed_num[0]]; | |
1418 | locked += !test_bit(R5_LOCKED, &adev->flags); | |
1419 | set_bit(R5_LOCKED, &adev->flags); | |
1420 | set_bit(R5_Wantwrite, &adev->flags); | |
1421 | bdev = &sh->dev[failed_num[1]]; | |
1422 | locked += !test_bit(R5_LOCKED, &bdev->flags); | |
1423 | set_bit(R5_LOCKED, &bdev->flags); | |
934ce7c8 | 1424 | clear_bit(STRIPE_DEGRADED, &sh->state); |
1da177e4 LT |
1425 | set_bit(R5_Wantwrite, &bdev->flags); |
1426 | ||
1427 | set_bit(STRIPE_INSYNC, &sh->state); | |
1428 | set_bit(R5_Syncio, &adev->flags); | |
1429 | set_bit(R5_Syncio, &bdev->flags); | |
1430 | } | |
1431 | } | |
1432 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | |
1433 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
1434 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1435 | } | |
1436 | ||
1437 | spin_unlock(&sh->lock); | |
1438 | ||
1439 | while ((bi=return_bi)) { | |
1440 | int bytes = bi->bi_size; | |
1441 | ||
1442 | return_bi = bi->bi_next; | |
1443 | bi->bi_next = NULL; | |
1444 | bi->bi_size = 0; | |
1445 | bi->bi_end_io(bi, bytes, 0); | |
1446 | } | |
1447 | for (i=disks; i-- ;) { | |
1448 | int rw; | |
1449 | struct bio *bi; | |
1450 | mdk_rdev_t *rdev; | |
1451 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | |
1452 | rw = 1; | |
1453 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | |
1454 | rw = 0; | |
1455 | else | |
1456 | continue; | |
1457 | ||
1458 | bi = &sh->dev[i].req; | |
1459 | ||
1460 | bi->bi_rw = rw; | |
1461 | if (rw) | |
1462 | bi->bi_end_io = raid6_end_write_request; | |
1463 | else | |
1464 | bi->bi_end_io = raid6_end_read_request; | |
1465 | ||
1466 | rcu_read_lock(); | |
1467 | rdev = conf->disks[i].rdev; | |
1468 | if (rdev && rdev->faulty) | |
1469 | rdev = NULL; | |
1470 | if (rdev) | |
1471 | atomic_inc(&rdev->nr_pending); | |
1472 | rcu_read_unlock(); | |
1473 | ||
1474 | if (rdev) { | |
1475 | if (test_bit(R5_Syncio, &sh->dev[i].flags)) | |
1476 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); | |
1477 | ||
1478 | bi->bi_bdev = rdev->bdev; | |
1479 | PRINTK("for %llu schedule op %ld on disc %d\n", | |
1480 | (unsigned long long)sh->sector, bi->bi_rw, i); | |
1481 | atomic_inc(&sh->count); | |
1482 | bi->bi_sector = sh->sector + rdev->data_offset; | |
1483 | bi->bi_flags = 1 << BIO_UPTODATE; | |
1484 | bi->bi_vcnt = 1; | |
1485 | bi->bi_max_vecs = 1; | |
1486 | bi->bi_idx = 0; | |
1487 | bi->bi_io_vec = &sh->dev[i].vec; | |
1488 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | |
1489 | bi->bi_io_vec[0].bv_offset = 0; | |
1490 | bi->bi_size = STRIPE_SIZE; | |
1491 | bi->bi_next = NULL; | |
1492 | generic_make_request(bi); | |
1493 | } else { | |
934ce7c8 N |
1494 | if (rw == 1) |
1495 | set_bit(STRIPE_DEGRADED, &sh->state); | |
1da177e4 LT |
1496 | PRINTK("skip op %ld on disc %d for sector %llu\n", |
1497 | bi->bi_rw, i, (unsigned long long)sh->sector); | |
1498 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1499 | set_bit(STRIPE_HANDLE, &sh->state); | |
1500 | } | |
1501 | } | |
1502 | } | |
1503 | ||
1504 | static inline void raid6_activate_delayed(raid6_conf_t *conf) | |
1505 | { | |
1506 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | |
1507 | while (!list_empty(&conf->delayed_list)) { | |
1508 | struct list_head *l = conf->delayed_list.next; | |
1509 | struct stripe_head *sh; | |
1510 | sh = list_entry(l, struct stripe_head, lru); | |
1511 | list_del_init(l); | |
1512 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1513 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1514 | atomic_inc(&conf->preread_active_stripes); | |
1515 | list_add_tail(&sh->lru, &conf->handle_list); | |
1516 | } | |
1517 | } | |
1518 | } | |
1519 | ||
934ce7c8 N |
1520 | static inline void activate_bit_delay(raid6_conf_t *conf) |
1521 | { | |
1522 | /* device_lock is held */ | |
1523 | struct list_head head; | |
1524 | list_add(&head, &conf->bitmap_list); | |
1525 | list_del_init(&conf->bitmap_list); | |
1526 | while (!list_empty(&head)) { | |
1527 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | |
1528 | list_del_init(&sh->lru); | |
1529 | atomic_inc(&sh->count); | |
1530 | __release_stripe(conf, sh); | |
1531 | } | |
1532 | } | |
1533 | ||
1da177e4 LT |
1534 | static void unplug_slaves(mddev_t *mddev) |
1535 | { | |
1536 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1537 | int i; | |
1538 | ||
1539 | rcu_read_lock(); | |
1540 | for (i=0; i<mddev->raid_disks; i++) { | |
1541 | mdk_rdev_t *rdev = conf->disks[i].rdev; | |
1542 | if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) { | |
1543 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); | |
1544 | ||
1545 | atomic_inc(&rdev->nr_pending); | |
1546 | rcu_read_unlock(); | |
1547 | ||
1548 | if (r_queue->unplug_fn) | |
1549 | r_queue->unplug_fn(r_queue); | |
1550 | ||
1551 | rdev_dec_pending(rdev, mddev); | |
1552 | rcu_read_lock(); | |
1553 | } | |
1554 | } | |
1555 | rcu_read_unlock(); | |
1556 | } | |
1557 | ||
1558 | static void raid6_unplug_device(request_queue_t *q) | |
1559 | { | |
1560 | mddev_t *mddev = q->queuedata; | |
1561 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1562 | unsigned long flags; | |
1563 | ||
1564 | spin_lock_irqsave(&conf->device_lock, flags); | |
1565 | ||
934ce7c8 N |
1566 | if (blk_remove_plug(q)) { |
1567 | conf->seq_flush++; | |
1da177e4 | 1568 | raid6_activate_delayed(conf); |
934ce7c8 | 1569 | } |
1da177e4 LT |
1570 | md_wakeup_thread(mddev->thread); |
1571 | ||
1572 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1573 | ||
1574 | unplug_slaves(mddev); | |
1575 | } | |
1576 | ||
1577 | static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk, | |
1578 | sector_t *error_sector) | |
1579 | { | |
1580 | mddev_t *mddev = q->queuedata; | |
1581 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1582 | int i, ret = 0; | |
1583 | ||
1584 | rcu_read_lock(); | |
1585 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
1586 | mdk_rdev_t *rdev = conf->disks[i].rdev; | |
1587 | if (rdev && !rdev->faulty) { | |
1588 | struct block_device *bdev = rdev->bdev; | |
1589 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
1590 | ||
1591 | if (!r_queue->issue_flush_fn) | |
1592 | ret = -EOPNOTSUPP; | |
1593 | else { | |
1594 | atomic_inc(&rdev->nr_pending); | |
1595 | rcu_read_unlock(); | |
1596 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
1597 | error_sector); | |
1598 | rdev_dec_pending(rdev, mddev); | |
1599 | rcu_read_lock(); | |
1600 | } | |
1601 | } | |
1602 | } | |
1603 | rcu_read_unlock(); | |
1604 | return ret; | |
1605 | } | |
1606 | ||
1607 | static inline void raid6_plug_device(raid6_conf_t *conf) | |
1608 | { | |
1609 | spin_lock_irq(&conf->device_lock); | |
1610 | blk_plug_device(conf->mddev->queue); | |
1611 | spin_unlock_irq(&conf->device_lock); | |
1612 | } | |
1613 | ||
1614 | static int make_request (request_queue_t *q, struct bio * bi) | |
1615 | { | |
1616 | mddev_t *mddev = q->queuedata; | |
1617 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1618 | const unsigned int raid_disks = conf->raid_disks; | |
1619 | const unsigned int data_disks = raid_disks - 2; | |
1620 | unsigned int dd_idx, pd_idx; | |
1621 | sector_t new_sector; | |
1622 | sector_t logical_sector, last_sector; | |
1623 | struct stripe_head *sh; | |
a362357b | 1624 | const int rw = bio_data_dir(bi); |
1da177e4 | 1625 | |
e5dcdd80 N |
1626 | if (unlikely(bio_barrier(bi))) { |
1627 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); | |
1628 | return 0; | |
1629 | } | |
1630 | ||
3d310eb7 | 1631 | md_write_start(mddev, bi); |
06d91a5f | 1632 | |
a362357b JA |
1633 | disk_stat_inc(mddev->gendisk, ios[rw]); |
1634 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | |
1da177e4 LT |
1635 | |
1636 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
1637 | last_sector = bi->bi_sector + (bi->bi_size>>9); | |
1638 | ||
1639 | bi->bi_next = NULL; | |
1640 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | |
06d91a5f | 1641 | |
1da177e4 LT |
1642 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
1643 | DEFINE_WAIT(w); | |
1644 | ||
1645 | new_sector = raid6_compute_sector(logical_sector, | |
1646 | raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1647 | ||
1648 | PRINTK("raid6: make_request, sector %llu logical %llu\n", | |
1649 | (unsigned long long)new_sector, | |
1650 | (unsigned long long)logical_sector); | |
1651 | ||
1652 | retry: | |
1653 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); | |
1654 | sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); | |
1655 | if (sh) { | |
1656 | if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | |
1657 | /* Add failed due to overlap. Flush everything | |
1658 | * and wait a while | |
1659 | */ | |
1660 | raid6_unplug_device(mddev->queue); | |
1661 | release_stripe(sh); | |
1662 | schedule(); | |
1663 | goto retry; | |
1664 | } | |
1665 | finish_wait(&conf->wait_for_overlap, &w); | |
1666 | raid6_plug_device(conf); | |
1667 | handle_stripe(sh); | |
1668 | release_stripe(sh); | |
1669 | } else { | |
1670 | /* cannot get stripe for read-ahead, just give-up */ | |
1671 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1672 | finish_wait(&conf->wait_for_overlap, &w); | |
1673 | break; | |
1674 | } | |
1675 | ||
1676 | } | |
1677 | spin_lock_irq(&conf->device_lock); | |
1678 | if (--bi->bi_phys_segments == 0) { | |
1679 | int bytes = bi->bi_size; | |
1680 | ||
a362357b | 1681 | if (rw == WRITE ) |
1da177e4 LT |
1682 | md_write_end(mddev); |
1683 | bi->bi_size = 0; | |
1684 | bi->bi_end_io(bi, bytes, 0); | |
1685 | } | |
1686 | spin_unlock_irq(&conf->device_lock); | |
1687 | return 0; | |
1688 | } | |
1689 | ||
1690 | /* FIXME go_faster isn't used */ | |
57afd89f | 1691 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1692 | { |
1693 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
1694 | struct stripe_head *sh; | |
1695 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1696 | sector_t x; | |
1697 | unsigned long stripe; | |
1698 | int chunk_offset; | |
1699 | int dd_idx, pd_idx; | |
1700 | sector_t first_sector; | |
1701 | int raid_disks = conf->raid_disks; | |
1702 | int data_disks = raid_disks - 2; | |
934ce7c8 N |
1703 | sector_t max_sector = mddev->size << 1; |
1704 | int sync_blocks; | |
1da177e4 | 1705 | |
934ce7c8 | 1706 | if (sector_nr >= max_sector) { |
1da177e4 LT |
1707 | /* just being told to finish up .. nothing much to do */ |
1708 | unplug_slaves(mddev); | |
934ce7c8 N |
1709 | |
1710 | if (mddev->curr_resync < max_sector) /* aborted */ | |
1711 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1712 | &sync_blocks, 1); | |
1713 | else /* compelted sync */ | |
1714 | conf->fullsync = 0; | |
1715 | bitmap_close_sync(mddev->bitmap); | |
1716 | ||
1da177e4 LT |
1717 | return 0; |
1718 | } | |
1719 | /* if there are 2 or more failed drives and we are trying | |
1720 | * to resync, then assert that we are finished, because there is | |
1721 | * nothing we can do. | |
1722 | */ | |
1723 | if (mddev->degraded >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
57afd89f N |
1724 | sector_t rv = (mddev->size << 1) - sector_nr; |
1725 | *skipped = 1; | |
1da177e4 LT |
1726 | return rv; |
1727 | } | |
934ce7c8 N |
1728 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
1729 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { | |
1730 | /* we can skip this block, and probably more */ | |
1731 | sync_blocks /= STRIPE_SECTORS; | |
1732 | *skipped = 1; | |
1733 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | |
1734 | } | |
1da177e4 LT |
1735 | |
1736 | x = sector_nr; | |
1737 | chunk_offset = sector_div(x, sectors_per_chunk); | |
1738 | stripe = x; | |
1739 | BUG_ON(x != stripe); | |
1740 | ||
1741 | first_sector = raid6_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk | |
1742 | + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1743 | sh = get_active_stripe(conf, sector_nr, pd_idx, 1); | |
1744 | if (sh == NULL) { | |
1745 | sh = get_active_stripe(conf, sector_nr, pd_idx, 0); | |
1746 | /* make sure we don't swamp the stripe cache if someone else | |
1747 | * is trying to get access | |
1748 | */ | |
66c006a5 | 1749 | schedule_timeout_uninterruptible(1); |
1da177e4 | 1750 | } |
934ce7c8 | 1751 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0); |
1da177e4 LT |
1752 | spin_lock(&sh->lock); |
1753 | set_bit(STRIPE_SYNCING, &sh->state); | |
1754 | clear_bit(STRIPE_INSYNC, &sh->state); | |
1755 | spin_unlock(&sh->lock); | |
1756 | ||
1757 | handle_stripe(sh); | |
1758 | release_stripe(sh); | |
1759 | ||
1760 | return STRIPE_SECTORS; | |
1761 | } | |
1762 | ||
1763 | /* | |
1764 | * This is our raid6 kernel thread. | |
1765 | * | |
1766 | * We scan the hash table for stripes which can be handled now. | |
1767 | * During the scan, completed stripes are saved for us by the interrupt | |
1768 | * handler, so that they will not have to wait for our next wakeup. | |
1769 | */ | |
1770 | static void raid6d (mddev_t *mddev) | |
1771 | { | |
1772 | struct stripe_head *sh; | |
1773 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
1774 | int handled; | |
1775 | ||
1776 | PRINTK("+++ raid6d active\n"); | |
1777 | ||
1778 | md_check_recovery(mddev); | |
1da177e4 LT |
1779 | |
1780 | handled = 0; | |
1781 | spin_lock_irq(&conf->device_lock); | |
1782 | while (1) { | |
1783 | struct list_head *first; | |
1784 | ||
934ce7c8 N |
1785 | if (conf->seq_flush - conf->seq_write > 0) { |
1786 | int seq = conf->seq_flush; | |
1787 | bitmap_unplug(mddev->bitmap); | |
1788 | conf->seq_write = seq; | |
1789 | activate_bit_delay(conf); | |
1790 | } | |
1791 | ||
1da177e4 LT |
1792 | if (list_empty(&conf->handle_list) && |
1793 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && | |
1794 | !blk_queue_plugged(mddev->queue) && | |
1795 | !list_empty(&conf->delayed_list)) | |
1796 | raid6_activate_delayed(conf); | |
1797 | ||
1798 | if (list_empty(&conf->handle_list)) | |
1799 | break; | |
1800 | ||
1801 | first = conf->handle_list.next; | |
1802 | sh = list_entry(first, struct stripe_head, lru); | |
1803 | ||
1804 | list_del_init(first); | |
1805 | atomic_inc(&sh->count); | |
1806 | if (atomic_read(&sh->count)!= 1) | |
1807 | BUG(); | |
1808 | spin_unlock_irq(&conf->device_lock); | |
1809 | ||
1810 | handled++; | |
1811 | handle_stripe(sh); | |
1812 | release_stripe(sh); | |
1813 | ||
1814 | spin_lock_irq(&conf->device_lock); | |
1815 | } | |
1816 | PRINTK("%d stripes handled\n", handled); | |
1817 | ||
1818 | spin_unlock_irq(&conf->device_lock); | |
1819 | ||
1820 | unplug_slaves(mddev); | |
1821 | ||
1822 | PRINTK("--- raid6d inactive\n"); | |
1823 | } | |
1824 | ||
934ce7c8 | 1825 | static int run(mddev_t *mddev) |
1da177e4 LT |
1826 | { |
1827 | raid6_conf_t *conf; | |
1828 | int raid_disk, memory; | |
1829 | mdk_rdev_t *rdev; | |
1830 | struct disk_info *disk; | |
1831 | struct list_head *tmp; | |
1832 | ||
1833 | if (mddev->level != 6) { | |
1834 | PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level); | |
1835 | return -EIO; | |
1836 | } | |
1837 | ||
1838 | mddev->private = kmalloc (sizeof (raid6_conf_t) | |
1839 | + mddev->raid_disks * sizeof(struct disk_info), | |
1840 | GFP_KERNEL); | |
1841 | if ((conf = mddev->private) == NULL) | |
1842 | goto abort; | |
1843 | memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) ); | |
1844 | conf->mddev = mddev; | |
1845 | ||
1846 | if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL) | |
1847 | goto abort; | |
1848 | memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE); | |
1849 | ||
1850 | spin_lock_init(&conf->device_lock); | |
1851 | init_waitqueue_head(&conf->wait_for_stripe); | |
1852 | init_waitqueue_head(&conf->wait_for_overlap); | |
1853 | INIT_LIST_HEAD(&conf->handle_list); | |
1854 | INIT_LIST_HEAD(&conf->delayed_list); | |
934ce7c8 | 1855 | INIT_LIST_HEAD(&conf->bitmap_list); |
1da177e4 LT |
1856 | INIT_LIST_HEAD(&conf->inactive_list); |
1857 | atomic_set(&conf->active_stripes, 0); | |
1858 | atomic_set(&conf->preread_active_stripes, 0); | |
1859 | ||
1da177e4 LT |
1860 | PRINTK("raid6: run(%s) called.\n", mdname(mddev)); |
1861 | ||
1862 | ITERATE_RDEV(mddev,rdev,tmp) { | |
1863 | raid_disk = rdev->raid_disk; | |
1864 | if (raid_disk >= mddev->raid_disks | |
1865 | || raid_disk < 0) | |
1866 | continue; | |
1867 | disk = conf->disks + raid_disk; | |
1868 | ||
1869 | disk->rdev = rdev; | |
1870 | ||
1871 | if (rdev->in_sync) { | |
1872 | char b[BDEVNAME_SIZE]; | |
1873 | printk(KERN_INFO "raid6: device %s operational as raid" | |
1874 | " disk %d\n", bdevname(rdev->bdev,b), | |
1875 | raid_disk); | |
1876 | conf->working_disks++; | |
1877 | } | |
1878 | } | |
1879 | ||
1880 | conf->raid_disks = mddev->raid_disks; | |
1881 | ||
1882 | /* | |
1883 | * 0 for a fully functional array, 1 or 2 for a degraded array. | |
1884 | */ | |
1885 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; | |
1886 | conf->mddev = mddev; | |
1887 | conf->chunk_size = mddev->chunk_size; | |
1888 | conf->level = mddev->level; | |
1889 | conf->algorithm = mddev->layout; | |
1890 | conf->max_nr_stripes = NR_STRIPES; | |
1891 | ||
1892 | /* device size must be a multiple of chunk size */ | |
1893 | mddev->size &= ~(mddev->chunk_size/1024 -1); | |
b1581566 | 1894 | mddev->resync_max_sectors = mddev->size << 1; |
1da177e4 LT |
1895 | |
1896 | if (conf->raid_disks < 4) { | |
1897 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", | |
1898 | mdname(mddev), conf->raid_disks); | |
1899 | goto abort; | |
1900 | } | |
1901 | if (!conf->chunk_size || conf->chunk_size % 4) { | |
1902 | printk(KERN_ERR "raid6: invalid chunk size %d for %s\n", | |
1903 | conf->chunk_size, mdname(mddev)); | |
1904 | goto abort; | |
1905 | } | |
1906 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | |
1907 | printk(KERN_ERR | |
1908 | "raid6: unsupported parity algorithm %d for %s\n", | |
1909 | conf->algorithm, mdname(mddev)); | |
1910 | goto abort; | |
1911 | } | |
1912 | if (mddev->degraded > 2) { | |
1913 | printk(KERN_ERR "raid6: not enough operational devices for %s" | |
1914 | " (%d/%d failed)\n", | |
1915 | mdname(mddev), conf->failed_disks, conf->raid_disks); | |
1916 | goto abort; | |
1917 | } | |
1918 | ||
1919 | #if 0 /* FIX: For now */ | |
1920 | if (mddev->degraded > 0 && | |
1921 | mddev->recovery_cp != MaxSector) { | |
1922 | printk(KERN_ERR "raid6: cannot start dirty degraded array for %s\n", mdname(mddev)); | |
1923 | goto abort; | |
1924 | } | |
1925 | #endif | |
1926 | ||
1927 | { | |
1928 | mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6"); | |
1929 | if (!mddev->thread) { | |
1930 | printk(KERN_ERR | |
1931 | "raid6: couldn't allocate thread for %s\n", | |
1932 | mdname(mddev)); | |
1933 | goto abort; | |
1934 | } | |
1935 | } | |
1936 | ||
1937 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + | |
1938 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; | |
1939 | if (grow_stripes(conf, conf->max_nr_stripes)) { | |
1940 | printk(KERN_ERR | |
1941 | "raid6: couldn't allocate %dkB for buffers\n", memory); | |
1942 | shrink_stripes(conf); | |
1943 | md_unregister_thread(mddev->thread); | |
1944 | goto abort; | |
1945 | } else | |
1946 | printk(KERN_INFO "raid6: allocated %dkB for %s\n", | |
1947 | memory, mdname(mddev)); | |
1948 | ||
1949 | if (mddev->degraded == 0) | |
1950 | printk(KERN_INFO "raid6: raid level %d set %s active with %d out of %d" | |
1951 | " devices, algorithm %d\n", conf->level, mdname(mddev), | |
1952 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | |
1953 | conf->algorithm); | |
1954 | else | |
1955 | printk(KERN_ALERT "raid6: raid level %d set %s active with %d" | |
1956 | " out of %d devices, algorithm %d\n", conf->level, | |
1957 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
1958 | mddev->raid_disks, conf->algorithm); | |
1959 | ||
1960 | print_raid6_conf(conf); | |
1961 | ||
1962 | /* read-ahead size must cover two whole stripes, which is | |
1963 | * 2 * (n-2) * chunksize where 'n' is the number of raid devices | |
1964 | */ | |
1965 | { | |
1966 | int stripe = (mddev->raid_disks-2) * mddev->chunk_size | |
1967 | / PAGE_CACHE_SIZE; | |
1968 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) | |
1969 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
1970 | } | |
1971 | ||
1972 | /* Ok, everything is just fine now */ | |
1973 | mddev->array_size = mddev->size * (mddev->raid_disks - 2); | |
7a5febe9 | 1974 | |
934ce7c8 N |
1975 | if (mddev->bitmap) |
1976 | mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; | |
1977 | ||
7a5febe9 N |
1978 | mddev->queue->unplug_fn = raid6_unplug_device; |
1979 | mddev->queue->issue_flush_fn = raid6_issue_flush; | |
1da177e4 LT |
1980 | return 0; |
1981 | abort: | |
1982 | if (conf) { | |
1983 | print_raid6_conf(conf); | |
1984 | if (conf->stripe_hashtbl) | |
1985 | free_pages((unsigned long) conf->stripe_hashtbl, | |
1986 | HASH_PAGES_ORDER); | |
1987 | kfree(conf); | |
1988 | } | |
1989 | mddev->private = NULL; | |
1990 | printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev)); | |
1991 | return -EIO; | |
1992 | } | |
1993 | ||
1994 | ||
1995 | ||
1996 | static int stop (mddev_t *mddev) | |
1997 | { | |
1998 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
1999 | ||
2000 | md_unregister_thread(mddev->thread); | |
2001 | mddev->thread = NULL; | |
2002 | shrink_stripes(conf); | |
2003 | free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); | |
2004 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
2005 | kfree(conf); | |
2006 | mddev->private = NULL; | |
2007 | return 0; | |
2008 | } | |
2009 | ||
2010 | #if RAID6_DUMPSTATE | |
2011 | static void print_sh (struct seq_file *seq, struct stripe_head *sh) | |
2012 | { | |
2013 | int i; | |
2014 | ||
2015 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", | |
2016 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | |
2017 | seq_printf(seq, "sh %llu, count %d.\n", | |
2018 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | |
2019 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); | |
2020 | for (i = 0; i < sh->raid_conf->raid_disks; i++) { | |
2021 | seq_printf(seq, "(cache%d: %p %ld) ", | |
2022 | i, sh->dev[i].page, sh->dev[i].flags); | |
2023 | } | |
2024 | seq_printf(seq, "\n"); | |
2025 | } | |
2026 | ||
2027 | static void printall (struct seq_file *seq, raid6_conf_t *conf) | |
2028 | { | |
2029 | struct stripe_head *sh; | |
2030 | int i; | |
2031 | ||
2032 | spin_lock_irq(&conf->device_lock); | |
2033 | for (i = 0; i < NR_HASH; i++) { | |
2034 | sh = conf->stripe_hashtbl[i]; | |
2035 | for (; sh; sh = sh->hash_next) { | |
2036 | if (sh->raid_conf != conf) | |
2037 | continue; | |
2038 | print_sh(seq, sh); | |
2039 | } | |
2040 | } | |
2041 | spin_unlock_irq(&conf->device_lock); | |
2042 | } | |
2043 | #endif | |
2044 | ||
2045 | static void status (struct seq_file *seq, mddev_t *mddev) | |
2046 | { | |
2047 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | |
2048 | int i; | |
2049 | ||
2050 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | |
2051 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); | |
2052 | for (i = 0; i < conf->raid_disks; i++) | |
2053 | seq_printf (seq, "%s", | |
2054 | conf->disks[i].rdev && | |
2055 | conf->disks[i].rdev->in_sync ? "U" : "_"); | |
2056 | seq_printf (seq, "]"); | |
2057 | #if RAID6_DUMPSTATE | |
2058 | seq_printf (seq, "\n"); | |
2059 | printall(seq, conf); | |
2060 | #endif | |
2061 | } | |
2062 | ||
2063 | static void print_raid6_conf (raid6_conf_t *conf) | |
2064 | { | |
2065 | int i; | |
2066 | struct disk_info *tmp; | |
2067 | ||
2068 | printk("RAID6 conf printout:\n"); | |
2069 | if (!conf) { | |
2070 | printk("(conf==NULL)\n"); | |
2071 | return; | |
2072 | } | |
2073 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, | |
2074 | conf->working_disks, conf->failed_disks); | |
2075 | ||
2076 | for (i = 0; i < conf->raid_disks; i++) { | |
2077 | char b[BDEVNAME_SIZE]; | |
2078 | tmp = conf->disks + i; | |
2079 | if (tmp->rdev) | |
2080 | printk(" disk %d, o:%d, dev:%s\n", | |
2081 | i, !tmp->rdev->faulty, | |
2082 | bdevname(tmp->rdev->bdev,b)); | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | static int raid6_spare_active(mddev_t *mddev) | |
2087 | { | |
2088 | int i; | |
2089 | raid6_conf_t *conf = mddev->private; | |
2090 | struct disk_info *tmp; | |
2091 | ||
2092 | for (i = 0; i < conf->raid_disks; i++) { | |
2093 | tmp = conf->disks + i; | |
2094 | if (tmp->rdev | |
2095 | && !tmp->rdev->faulty | |
2096 | && !tmp->rdev->in_sync) { | |
2097 | mddev->degraded--; | |
2098 | conf->failed_disks--; | |
2099 | conf->working_disks++; | |
2100 | tmp->rdev->in_sync = 1; | |
2101 | } | |
2102 | } | |
2103 | print_raid6_conf(conf); | |
2104 | return 0; | |
2105 | } | |
2106 | ||
2107 | static int raid6_remove_disk(mddev_t *mddev, int number) | |
2108 | { | |
2109 | raid6_conf_t *conf = mddev->private; | |
2110 | int err = 0; | |
2111 | mdk_rdev_t *rdev; | |
2112 | struct disk_info *p = conf->disks + number; | |
2113 | ||
2114 | print_raid6_conf(conf); | |
2115 | rdev = p->rdev; | |
2116 | if (rdev) { | |
2117 | if (rdev->in_sync || | |
2118 | atomic_read(&rdev->nr_pending)) { | |
2119 | err = -EBUSY; | |
2120 | goto abort; | |
2121 | } | |
2122 | p->rdev = NULL; | |
fbd568a3 | 2123 | synchronize_rcu(); |
1da177e4 LT |
2124 | if (atomic_read(&rdev->nr_pending)) { |
2125 | /* lost the race, try later */ | |
2126 | err = -EBUSY; | |
2127 | p->rdev = rdev; | |
2128 | } | |
2129 | } | |
2130 | ||
2131 | abort: | |
2132 | ||
2133 | print_raid6_conf(conf); | |
2134 | return err; | |
2135 | } | |
2136 | ||
2137 | static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
2138 | { | |
2139 | raid6_conf_t *conf = mddev->private; | |
2140 | int found = 0; | |
2141 | int disk; | |
2142 | struct disk_info *p; | |
2143 | ||
2144 | if (mddev->degraded > 2) | |
2145 | /* no point adding a device */ | |
2146 | return 0; | |
2147 | /* | |
2148 | * find the disk ... | |
2149 | */ | |
2150 | for (disk=0; disk < mddev->raid_disks; disk++) | |
2151 | if ((p=conf->disks + disk)->rdev == NULL) { | |
2152 | rdev->in_sync = 0; | |
2153 | rdev->raid_disk = disk; | |
2154 | found = 1; | |
934ce7c8 N |
2155 | if (rdev->saved_raid_disk != disk) |
2156 | conf->fullsync = 1; | |
1da177e4 LT |
2157 | p->rdev = rdev; |
2158 | break; | |
2159 | } | |
2160 | print_raid6_conf(conf); | |
2161 | return found; | |
2162 | } | |
2163 | ||
2164 | static int raid6_resize(mddev_t *mddev, sector_t sectors) | |
2165 | { | |
2166 | /* no resync is happening, and there is enough space | |
2167 | * on all devices, so we can resize. | |
2168 | * We need to make sure resync covers any new space. | |
2169 | * If the array is shrinking we should possibly wait until | |
2170 | * any io in the removed space completes, but it hardly seems | |
2171 | * worth it. | |
2172 | */ | |
2173 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | |
2174 | mddev->array_size = (sectors * (mddev->raid_disks-2))>>1; | |
2175 | set_capacity(mddev->gendisk, mddev->array_size << 1); | |
2176 | mddev->changed = 1; | |
2177 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | |
2178 | mddev->recovery_cp = mddev->size << 1; | |
2179 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
2180 | } | |
2181 | mddev->size = sectors /2; | |
4b5c7ae8 | 2182 | mddev->resync_max_sectors = sectors; |
1da177e4 LT |
2183 | return 0; |
2184 | } | |
2185 | ||
934ce7c8 N |
2186 | static void raid6_quiesce(mddev_t *mddev, int state) |
2187 | { | |
2188 | raid6_conf_t *conf = mddev_to_conf(mddev); | |
2189 | ||
2190 | switch(state) { | |
2191 | case 1: /* stop all writes */ | |
2192 | spin_lock_irq(&conf->device_lock); | |
2193 | conf->quiesce = 1; | |
2194 | wait_event_lock_irq(conf->wait_for_stripe, | |
2195 | atomic_read(&conf->active_stripes) == 0, | |
2196 | conf->device_lock, /* nothing */); | |
2197 | spin_unlock_irq(&conf->device_lock); | |
2198 | break; | |
2199 | ||
2200 | case 0: /* re-enable writes */ | |
2201 | spin_lock_irq(&conf->device_lock); | |
2202 | conf->quiesce = 0; | |
2203 | wake_up(&conf->wait_for_stripe); | |
2204 | spin_unlock_irq(&conf->device_lock); | |
2205 | break; | |
2206 | } | |
2207 | if (mddev->thread) { | |
2208 | if (mddev->bitmap) | |
2209 | mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; | |
2210 | else | |
2211 | mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; | |
2212 | md_wakeup_thread(mddev->thread); | |
2213 | } | |
2214 | } | |
1da177e4 LT |
2215 | static mdk_personality_t raid6_personality= |
2216 | { | |
2217 | .name = "raid6", | |
2218 | .owner = THIS_MODULE, | |
2219 | .make_request = make_request, | |
2220 | .run = run, | |
2221 | .stop = stop, | |
2222 | .status = status, | |
2223 | .error_handler = error, | |
2224 | .hot_add_disk = raid6_add_disk, | |
2225 | .hot_remove_disk= raid6_remove_disk, | |
2226 | .spare_active = raid6_spare_active, | |
2227 | .sync_request = sync_request, | |
2228 | .resize = raid6_resize, | |
934ce7c8 | 2229 | .quiesce = raid6_quiesce, |
1da177e4 LT |
2230 | }; |
2231 | ||
2232 | static int __init raid6_init (void) | |
2233 | { | |
2234 | int e; | |
2235 | ||
2236 | e = raid6_select_algo(); | |
2237 | if ( e ) | |
2238 | return e; | |
2239 | ||
2240 | return register_md_personality (RAID6, &raid6_personality); | |
2241 | } | |
2242 | ||
2243 | static void raid6_exit (void) | |
2244 | { | |
2245 | unregister_md_personality (RAID6); | |
2246 | } | |
2247 | ||
2248 | module_init(raid6_init); | |
2249 | module_exit(raid6_exit); | |
2250 | MODULE_LICENSE("GPL"); | |
2251 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ |