diff options
Diffstat (limited to 'drivers/md/raid6main.c')
-rw-r--r-- | drivers/md/raid6main.c | 2427 |
1 files changed, 0 insertions, 2427 deletions
diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c deleted file mode 100644 index bc69355e0100..000000000000 --- a/drivers/md/raid6main.c +++ /dev/null | |||
@@ -1,2427 +0,0 @@ | |||
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 | |||
32 | #include <linux/raid/bitmap.h> | ||
33 | |||
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 NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) | ||
44 | #define HASH_MASK (NR_HASH - 1) | ||
45 | |||
46 | #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) | ||
47 | |||
48 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector | ||
49 | * order without overlap. There may be several bio's per stripe+device, and | ||
50 | * a bio could span several devices. | ||
51 | * When walking this list for a particular stripe+device, we must never proceed | ||
52 | * beyond a bio that extends past this device, as the next bio might no longer | ||
53 | * be valid. | ||
54 | * This macro is used to determine the 'next' bio in the list, given the sector | ||
55 | * of the current stripe+device | ||
56 | */ | ||
57 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) | ||
58 | /* | ||
59 | * The following can be used to debug the driver | ||
60 | */ | ||
61 | #define RAID6_DEBUG 0 /* Extremely verbose printk */ | ||
62 | #define RAID6_PARANOIA 1 /* Check spinlocks */ | ||
63 | #define RAID6_DUMPSTATE 0 /* Include stripe cache state in /proc/mdstat */ | ||
64 | #if RAID6_PARANOIA && defined(CONFIG_SMP) | ||
65 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) | ||
66 | #else | ||
67 | # define CHECK_DEVLOCK() | ||
68 | #endif | ||
69 | |||
70 | #define PRINTK(x...) ((void)(RAID6_DEBUG && printk(KERN_DEBUG x))) | ||
71 | #if RAID6_DEBUG | ||
72 | #undef inline | ||
73 | #undef __inline__ | ||
74 | #define inline | ||
75 | #define __inline__ | ||
76 | #endif | ||
77 | |||
78 | #if !RAID6_USE_EMPTY_ZERO_PAGE | ||
79 | /* In .bss so it's zeroed */ | ||
80 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); | ||
81 | #endif | ||
82 | |||
83 | static inline int raid6_next_disk(int disk, int raid_disks) | ||
84 | { | ||
85 | disk++; | ||
86 | return (disk < raid_disks) ? disk : 0; | ||
87 | } | ||
88 | |||
89 | static void print_raid6_conf (raid6_conf_t *conf); | ||
90 | |||
91 | static void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) | ||
92 | { | ||
93 | if (atomic_dec_and_test(&sh->count)) { | ||
94 | BUG_ON(!list_empty(&sh->lru)); | ||
95 | BUG_ON(atomic_read(&conf->active_stripes)==0); | ||
96 | if (test_bit(STRIPE_HANDLE, &sh->state)) { | ||
97 | if (test_bit(STRIPE_DELAYED, &sh->state)) | ||
98 | list_add_tail(&sh->lru, &conf->delayed_list); | ||
99 | else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && | ||
100 | conf->seq_write == sh->bm_seq) | ||
101 | list_add_tail(&sh->lru, &conf->bitmap_list); | ||
102 | else { | ||
103 | clear_bit(STRIPE_BIT_DELAY, &sh->state); | ||
104 | list_add_tail(&sh->lru, &conf->handle_list); | ||
105 | } | ||
106 | md_wakeup_thread(conf->mddev->thread); | ||
107 | } else { | ||
108 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | ||
109 | atomic_dec(&conf->preread_active_stripes); | ||
110 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | ||
111 | md_wakeup_thread(conf->mddev->thread); | ||
112 | } | ||
113 | list_add_tail(&sh->lru, &conf->inactive_list); | ||
114 | atomic_dec(&conf->active_stripes); | ||
115 | if (!conf->inactive_blocked || | ||
116 | atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4)) | ||
117 | wake_up(&conf->wait_for_stripe); | ||
118 | } | ||
119 | } | ||
120 | } | ||
121 | static void release_stripe(struct stripe_head *sh) | ||
122 | { | ||
123 | raid6_conf_t *conf = sh->raid_conf; | ||
124 | unsigned long flags; | ||
125 | |||
126 | spin_lock_irqsave(&conf->device_lock, flags); | ||
127 | __release_stripe(conf, sh); | ||
128 | spin_unlock_irqrestore(&conf->device_lock, flags); | ||
129 | } | ||
130 | |||
131 | static inline void remove_hash(struct stripe_head *sh) | ||
132 | { | ||
133 | PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); | ||
134 | |||
135 | hlist_del_init(&sh->hash); | ||
136 | } | ||
137 | |||
138 | static inline void insert_hash(raid6_conf_t *conf, struct stripe_head *sh) | ||
139 | { | ||
140 | struct hlist_head *hp = stripe_hash(conf, sh->sector); | ||
141 | |||
142 | PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); | ||
143 | |||
144 | CHECK_DEVLOCK(); | ||
145 | hlist_add_head(&sh->hash, hp); | ||
146 | } | ||
147 | |||
148 | |||
149 | /* find an idle stripe, make sure it is unhashed, and return it. */ | ||
150 | static struct stripe_head *get_free_stripe(raid6_conf_t *conf) | ||
151 | { | ||
152 | struct stripe_head *sh = NULL; | ||
153 | struct list_head *first; | ||
154 | |||
155 | CHECK_DEVLOCK(); | ||
156 | if (list_empty(&conf->inactive_list)) | ||
157 | goto out; | ||
158 | first = conf->inactive_list.next; | ||
159 | sh = list_entry(first, struct stripe_head, lru); | ||
160 | list_del_init(first); | ||
161 | remove_hash(sh); | ||
162 | atomic_inc(&conf->active_stripes); | ||
163 | out: | ||
164 | return sh; | ||
165 | } | ||
166 | |||
167 | static void shrink_buffers(struct stripe_head *sh, int num) | ||
168 | { | ||
169 | struct page *p; | ||
170 | int i; | ||
171 | |||
172 | for (i=0; i<num ; i++) { | ||
173 | p = sh->dev[i].page; | ||
174 | if (!p) | ||
175 | continue; | ||
176 | sh->dev[i].page = NULL; | ||
177 | put_page(p); | ||
178 | } | ||
179 | } | ||
180 | |||
181 | static int grow_buffers(struct stripe_head *sh, int num) | ||
182 | { | ||
183 | int i; | ||
184 | |||
185 | for (i=0; i<num; i++) { | ||
186 | struct page *page; | ||
187 | |||
188 | if (!(page = alloc_page(GFP_KERNEL))) { | ||
189 | return 1; | ||
190 | } | ||
191 | sh->dev[i].page = page; | ||
192 | } | ||
193 | return 0; | ||
194 | } | ||
195 | |||
196 | static void raid6_build_block (struct stripe_head *sh, int i); | ||
197 | |||
198 | static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) | ||
199 | { | ||
200 | raid6_conf_t *conf = sh->raid_conf; | ||
201 | int disks = conf->raid_disks, i; | ||
202 | |||
203 | BUG_ON(atomic_read(&sh->count) != 0); | ||
204 | BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); | ||
205 | |||
206 | CHECK_DEVLOCK(); | ||
207 | PRINTK("init_stripe called, stripe %llu\n", | ||
208 | (unsigned long long)sh->sector); | ||
209 | |||
210 | remove_hash(sh); | ||
211 | |||
212 | sh->sector = sector; | ||
213 | sh->pd_idx = pd_idx; | ||
214 | sh->state = 0; | ||
215 | |||
216 | for (i=disks; i--; ) { | ||
217 | struct r5dev *dev = &sh->dev[i]; | ||
218 | |||
219 | if (dev->toread || dev->towrite || dev->written || | ||
220 | test_bit(R5_LOCKED, &dev->flags)) { | ||
221 | PRINTK("sector=%llx i=%d %p %p %p %d\n", | ||
222 | (unsigned long long)sh->sector, i, dev->toread, | ||
223 | dev->towrite, dev->written, | ||
224 | test_bit(R5_LOCKED, &dev->flags)); | ||
225 | BUG(); | ||
226 | } | ||
227 | dev->flags = 0; | ||
228 | raid6_build_block(sh, i); | ||
229 | } | ||
230 | insert_hash(conf, sh); | ||
231 | } | ||
232 | |||
233 | static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector) | ||
234 | { | ||
235 | struct stripe_head *sh; | ||
236 | struct hlist_node *hn; | ||
237 | |||
238 | CHECK_DEVLOCK(); | ||
239 | PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); | ||
240 | hlist_for_each_entry (sh, hn, stripe_hash(conf, sector), hash) | ||
241 | if (sh->sector == sector) | ||
242 | return sh; | ||
243 | PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); | ||
244 | return NULL; | ||
245 | } | ||
246 | |||
247 | static void unplug_slaves(mddev_t *mddev); | ||
248 | |||
249 | static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector, | ||
250 | int pd_idx, int noblock) | ||
251 | { | ||
252 | struct stripe_head *sh; | ||
253 | |||
254 | PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); | ||
255 | |||
256 | spin_lock_irq(&conf->device_lock); | ||
257 | |||
258 | do { | ||
259 | wait_event_lock_irq(conf->wait_for_stripe, | ||
260 | conf->quiesce == 0, | ||
261 | conf->device_lock, /* nothing */); | ||
262 | sh = __find_stripe(conf, sector); | ||
263 | if (!sh) { | ||
264 | if (!conf->inactive_blocked) | ||
265 | sh = get_free_stripe(conf); | ||
266 | if (noblock && sh == NULL) | ||
267 | break; | ||
268 | if (!sh) { | ||
269 | conf->inactive_blocked = 1; | ||
270 | wait_event_lock_irq(conf->wait_for_stripe, | ||
271 | !list_empty(&conf->inactive_list) && | ||
272 | (atomic_read(&conf->active_stripes) | ||
273 | < (conf->max_nr_stripes *3/4) | ||
274 | || !conf->inactive_blocked), | ||
275 | conf->device_lock, | ||
276 | unplug_slaves(conf->mddev); | ||
277 | ); | ||
278 | conf->inactive_blocked = 0; | ||
279 | } else | ||
280 | init_stripe(sh, sector, pd_idx); | ||
281 | } else { | ||
282 | if (atomic_read(&sh->count)) { | ||
283 | BUG_ON(!list_empty(&sh->lru)); | ||
284 | } else { | ||
285 | if (!test_bit(STRIPE_HANDLE, &sh->state)) | ||
286 | atomic_inc(&conf->active_stripes); | ||
287 | BUG_ON(list_empty(&sh->lru)); | ||
288 | list_del_init(&sh->lru); | ||
289 | } | ||
290 | } | ||
291 | } while (sh == NULL); | ||
292 | |||
293 | if (sh) | ||
294 | atomic_inc(&sh->count); | ||
295 | |||
296 | spin_unlock_irq(&conf->device_lock); | ||
297 | return sh; | ||
298 | } | ||
299 | |||
300 | static int grow_one_stripe(raid6_conf_t *conf) | ||
301 | { | ||
302 | struct stripe_head *sh; | ||
303 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); | ||
304 | if (!sh) | ||
305 | return 0; | ||
306 | memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); | ||
307 | sh->raid_conf = conf; | ||
308 | spin_lock_init(&sh->lock); | ||
309 | |||
310 | if (grow_buffers(sh, conf->raid_disks)) { | ||
311 | shrink_buffers(sh, conf->raid_disks); | ||
312 | kmem_cache_free(conf->slab_cache, sh); | ||
313 | return 0; | ||
314 | } | ||
315 | /* we just created an active stripe so... */ | ||
316 | atomic_set(&sh->count, 1); | ||
317 | atomic_inc(&conf->active_stripes); | ||
318 | INIT_LIST_HEAD(&sh->lru); | ||
319 | release_stripe(sh); | ||
320 | return 1; | ||
321 | } | ||
322 | |||
323 | static int grow_stripes(raid6_conf_t *conf, int num) | ||
324 | { | ||
325 | kmem_cache_t *sc; | ||
326 | int devs = conf->raid_disks; | ||
327 | |||
328 | sprintf(conf->cache_name[0], "raid6/%s", mdname(conf->mddev)); | ||
329 | |||
330 | sc = kmem_cache_create(conf->cache_name[0], | ||
331 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), | ||
332 | 0, 0, NULL, NULL); | ||
333 | if (!sc) | ||
334 | return 1; | ||
335 | conf->slab_cache = sc; | ||
336 | while (num--) | ||
337 | if (!grow_one_stripe(conf)) | ||
338 | return 1; | ||
339 | return 0; | ||
340 | } | ||
341 | |||
342 | static int drop_one_stripe(raid6_conf_t *conf) | ||
343 | { | ||
344 | struct stripe_head *sh; | ||
345 | spin_lock_irq(&conf->device_lock); | ||
346 | sh = get_free_stripe(conf); | ||
347 | spin_unlock_irq(&conf->device_lock); | ||
348 | if (!sh) | ||
349 | return 0; | ||
350 | BUG_ON(atomic_read(&sh->count)); | ||
351 | shrink_buffers(sh, conf->raid_disks); | ||
352 | kmem_cache_free(conf->slab_cache, sh); | ||
353 | atomic_dec(&conf->active_stripes); | ||
354 | return 1; | ||
355 | } | ||
356 | |||
357 | static void shrink_stripes(raid6_conf_t *conf) | ||
358 | { | ||
359 | while (drop_one_stripe(conf)) | ||
360 | ; | ||
361 | |||
362 | if (conf->slab_cache) | ||
363 | kmem_cache_destroy(conf->slab_cache); | ||
364 | conf->slab_cache = NULL; | ||
365 | } | ||
366 | |||
367 | static int raid6_end_read_request(struct bio * bi, unsigned int bytes_done, | ||
368 | int error) | ||
369 | { | ||
370 | struct stripe_head *sh = bi->bi_private; | ||
371 | raid6_conf_t *conf = sh->raid_conf; | ||
372 | int disks = conf->raid_disks, i; | ||
373 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | ||
374 | |||
375 | if (bi->bi_size) | ||
376 | return 1; | ||
377 | |||
378 | for (i=0 ; i<disks; i++) | ||
379 | if (bi == &sh->dev[i].req) | ||
380 | break; | ||
381 | |||
382 | PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", | ||
383 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | ||
384 | uptodate); | ||
385 | if (i == disks) { | ||
386 | BUG(); | ||
387 | return 0; | ||
388 | } | ||
389 | |||
390 | if (uptodate) { | ||
391 | #if 0 | ||
392 | struct bio *bio; | ||
393 | unsigned long flags; | ||
394 | spin_lock_irqsave(&conf->device_lock, flags); | ||
395 | /* we can return a buffer if we bypassed the cache or | ||
396 | * if the top buffer is not in highmem. If there are | ||
397 | * multiple buffers, leave the extra work to | ||
398 | * handle_stripe | ||
399 | */ | ||
400 | buffer = sh->bh_read[i]; | ||
401 | if (buffer && | ||
402 | (!PageHighMem(buffer->b_page) | ||
403 | || buffer->b_page == bh->b_page ) | ||
404 | ) { | ||
405 | sh->bh_read[i] = buffer->b_reqnext; | ||
406 | buffer->b_reqnext = NULL; | ||
407 | } else | ||
408 | buffer = NULL; | ||
409 | spin_unlock_irqrestore(&conf->device_lock, flags); | ||
410 | if (sh->bh_page[i]==bh->b_page) | ||
411 | set_buffer_uptodate(bh); | ||
412 | if (buffer) { | ||
413 | if (buffer->b_page != bh->b_page) | ||
414 | memcpy(buffer->b_data, bh->b_data, bh->b_size); | ||
415 | buffer->b_end_io(buffer, 1); | ||
416 | } | ||
417 | #else | ||
418 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | ||
419 | #endif | ||
420 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | ||
421 | printk(KERN_INFO "raid6: read error corrected!!\n"); | ||
422 | clear_bit(R5_ReadError, &sh->dev[i].flags); | ||
423 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | ||
424 | } | ||
425 | if (atomic_read(&conf->disks[i].rdev->read_errors)) | ||
426 | atomic_set(&conf->disks[i].rdev->read_errors, 0); | ||
427 | } else { | ||
428 | int retry = 0; | ||
429 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); | ||
430 | atomic_inc(&conf->disks[i].rdev->read_errors); | ||
431 | if (conf->mddev->degraded) | ||
432 | printk(KERN_WARNING "raid6: read error not correctable.\n"); | ||
433 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) | ||
434 | /* Oh, no!!! */ | ||
435 | printk(KERN_WARNING "raid6: read error NOT corrected!!\n"); | ||
436 | else if (atomic_read(&conf->disks[i].rdev->read_errors) | ||
437 | > conf->max_nr_stripes) | ||
438 | printk(KERN_WARNING | ||
439 | "raid6: Too many read errors, failing device.\n"); | ||
440 | else | ||
441 | retry = 1; | ||
442 | if (retry) | ||
443 | set_bit(R5_ReadError, &sh->dev[i].flags); | ||
444 | else { | ||
445 | clear_bit(R5_ReadError, &sh->dev[i].flags); | ||
446 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | ||
447 | md_error(conf->mddev, conf->disks[i].rdev); | ||
448 | } | ||
449 | } | ||
450 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | ||
451 | #if 0 | ||
452 | /* must restore b_page before unlocking buffer... */ | ||
453 | if (sh->bh_page[i] != bh->b_page) { | ||
454 | bh->b_page = sh->bh_page[i]; | ||
455 | bh->b_data = page_address(bh->b_page); | ||
456 | clear_buffer_uptodate(bh); | ||
457 | } | ||
458 | #endif | ||
459 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | ||
460 | set_bit(STRIPE_HANDLE, &sh->state); | ||
461 | release_stripe(sh); | ||
462 | return 0; | ||
463 | } | ||
464 | |||
465 | static int raid6_end_write_request (struct bio *bi, unsigned int bytes_done, | ||
466 | int error) | ||
467 | { | ||
468 | struct stripe_head *sh = bi->bi_private; | ||
469 | raid6_conf_t *conf = sh->raid_conf; | ||
470 | int disks = conf->raid_disks, i; | ||
471 | unsigned long flags; | ||
472 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | ||
473 | |||
474 | if (bi->bi_size) | ||
475 | return 1; | ||
476 | |||
477 | for (i=0 ; i<disks; i++) | ||
478 | if (bi == &sh->dev[i].req) | ||
479 | break; | ||
480 | |||
481 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", | ||
482 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | ||
483 | uptodate); | ||
484 | if (i == disks) { | ||
485 | BUG(); | ||
486 | return 0; | ||
487 | } | ||
488 | |||
489 | spin_lock_irqsave(&conf->device_lock, flags); | ||
490 | if (!uptodate) | ||
491 | md_error(conf->mddev, conf->disks[i].rdev); | ||
492 | |||
493 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | ||
494 | |||
495 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | ||
496 | set_bit(STRIPE_HANDLE, &sh->state); | ||
497 | __release_stripe(conf, sh); | ||
498 | spin_unlock_irqrestore(&conf->device_lock, flags); | ||
499 | return 0; | ||
500 | } | ||
501 | |||
502 | |||
503 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | ||
504 | |||
505 | static void raid6_build_block (struct stripe_head *sh, int i) | ||
506 | { | ||
507 | struct r5dev *dev = &sh->dev[i]; | ||
508 | int pd_idx = sh->pd_idx; | ||
509 | int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks); | ||
510 | |||
511 | bio_init(&dev->req); | ||
512 | dev->req.bi_io_vec = &dev->vec; | ||
513 | dev->req.bi_vcnt++; | ||
514 | dev->req.bi_max_vecs++; | ||
515 | dev->vec.bv_page = dev->page; | ||
516 | dev->vec.bv_len = STRIPE_SIZE; | ||
517 | dev->vec.bv_offset = 0; | ||
518 | |||
519 | dev->req.bi_sector = sh->sector; | ||
520 | dev->req.bi_private = sh; | ||
521 | |||
522 | dev->flags = 0; | ||
523 | if (i != pd_idx && i != qd_idx) | ||
524 | dev->sector = compute_blocknr(sh, i); | ||
525 | } | ||
526 | |||
527 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | ||
528 | { | ||
529 | char b[BDEVNAME_SIZE]; | ||
530 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | ||
531 | PRINTK("raid6: error called\n"); | ||
532 | |||
533 | if (!test_bit(Faulty, &rdev->flags)) { | ||
534 | mddev->sb_dirty = 1; | ||
535 | if (test_bit(In_sync, &rdev->flags)) { | ||
536 | conf->working_disks--; | ||
537 | mddev->degraded++; | ||
538 | conf->failed_disks++; | ||
539 | clear_bit(In_sync, &rdev->flags); | ||
540 | /* | ||
541 | * if recovery was running, make sure it aborts. | ||
542 | */ | ||
543 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | ||
544 | } | ||
545 | set_bit(Faulty, &rdev->flags); | ||
546 | printk (KERN_ALERT | ||
547 | "raid6: Disk failure on %s, disabling device." | ||
548 | " Operation continuing on %d devices\n", | ||
549 | bdevname(rdev->bdev,b), conf->working_disks); | ||
550 | } | ||
551 | } | ||
552 | |||
553 | /* | ||
554 | * Input: a 'big' sector number, | ||
555 | * Output: index of the data and parity disk, and the sector # in them. | ||
556 | */ | ||
557 | static sector_t raid6_compute_sector(sector_t r_sector, unsigned int raid_disks, | ||
558 | unsigned int data_disks, unsigned int * dd_idx, | ||
559 | unsigned int * pd_idx, raid6_conf_t *conf) | ||
560 | { | ||
561 | long stripe; | ||
562 | unsigned long chunk_number; | ||
563 | unsigned int chunk_offset; | ||
564 | sector_t new_sector; | ||
565 | int sectors_per_chunk = conf->chunk_size >> 9; | ||
566 | |||
567 | /* First compute the information on this sector */ | ||
568 | |||
569 | /* | ||
570 | * Compute the chunk number and the sector offset inside the chunk | ||
571 | */ | ||
572 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | ||
573 | chunk_number = r_sector; | ||
574 | if ( r_sector != chunk_number ) { | ||
575 | printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n", | ||
576 | (unsigned long long)r_sector, (unsigned long)chunk_number); | ||
577 | BUG(); | ||
578 | } | ||
579 | |||
580 | /* | ||
581 | * Compute the stripe number | ||
582 | */ | ||
583 | stripe = chunk_number / data_disks; | ||
584 | |||
585 | /* | ||
586 | * Compute the data disk and parity disk indexes inside the stripe | ||
587 | */ | ||
588 | *dd_idx = chunk_number % data_disks; | ||
589 | |||
590 | /* | ||
591 | * Select the parity disk based on the user selected algorithm. | ||
592 | */ | ||
593 | |||
594 | /**** FIX THIS ****/ | ||
595 | switch (conf->algorithm) { | ||
596 | case ALGORITHM_LEFT_ASYMMETRIC: | ||
597 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | ||
598 | if (*pd_idx == raid_disks-1) | ||
599 | (*dd_idx)++; /* Q D D D P */ | ||
600 | else if (*dd_idx >= *pd_idx) | ||
601 | (*dd_idx) += 2; /* D D P Q D */ | ||
602 | break; | ||
603 | case ALGORITHM_RIGHT_ASYMMETRIC: | ||
604 | *pd_idx = stripe % raid_disks; | ||
605 | if (*pd_idx == raid_disks-1) | ||
606 | (*dd_idx)++; /* Q D D D P */ | ||
607 | else if (*dd_idx >= *pd_idx) | ||
608 | (*dd_idx) += 2; /* D D P Q D */ | ||
609 | break; | ||
610 | case ALGORITHM_LEFT_SYMMETRIC: | ||
611 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); | ||
612 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | ||
613 | break; | ||
614 | case ALGORITHM_RIGHT_SYMMETRIC: | ||
615 | *pd_idx = stripe % raid_disks; | ||
616 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; | ||
617 | break; | ||
618 | default: | ||
619 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | ||
620 | conf->algorithm); | ||
621 | } | ||
622 | |||
623 | PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n", | ||
624 | chunk_number, *pd_idx, *dd_idx); | ||
625 | |||
626 | /* | ||
627 | * Finally, compute the new sector number | ||
628 | */ | ||
629 | new_sector = (sector_t) stripe * sectors_per_chunk + chunk_offset; | ||
630 | return new_sector; | ||
631 | } | ||
632 | |||
633 | |||
634 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | ||
635 | { | ||
636 | raid6_conf_t *conf = sh->raid_conf; | ||
637 | int raid_disks = conf->raid_disks, data_disks = raid_disks - 2; | ||
638 | sector_t new_sector = sh->sector, check; | ||
639 | int sectors_per_chunk = conf->chunk_size >> 9; | ||
640 | sector_t stripe; | ||
641 | int chunk_offset; | ||
642 | int chunk_number, dummy1, dummy2, dd_idx = i; | ||
643 | sector_t r_sector; | ||
644 | int i0 = i; | ||
645 | |||
646 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | ||
647 | stripe = new_sector; | ||
648 | if ( new_sector != stripe ) { | ||
649 | printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n", | ||
650 | (unsigned long long)new_sector, (unsigned long)stripe); | ||
651 | BUG(); | ||
652 | } | ||
653 | |||
654 | switch (conf->algorithm) { | ||
655 | case ALGORITHM_LEFT_ASYMMETRIC: | ||
656 | case ALGORITHM_RIGHT_ASYMMETRIC: | ||
657 | if (sh->pd_idx == raid_disks-1) | ||
658 | i--; /* Q D D D P */ | ||
659 | else if (i > sh->pd_idx) | ||
660 | i -= 2; /* D D P Q D */ | ||
661 | break; | ||
662 | case ALGORITHM_LEFT_SYMMETRIC: | ||
663 | case ALGORITHM_RIGHT_SYMMETRIC: | ||
664 | if (sh->pd_idx == raid_disks-1) | ||
665 | i--; /* Q D D D P */ | ||
666 | else { | ||
667 | /* D D P Q D */ | ||
668 | if (i < sh->pd_idx) | ||
669 | i += raid_disks; | ||
670 | i -= (sh->pd_idx + 2); | ||
671 | } | ||
672 | break; | ||
673 | default: | ||
674 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", | ||
675 | conf->algorithm); | ||
676 | } | ||
677 | |||
678 | PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i); | ||
679 | |||
680 | chunk_number = stripe * data_disks + i; | ||
681 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | ||
682 | |||
683 | check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | ||
684 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | ||
685 | printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n"); | ||
686 | return 0; | ||
687 | } | ||
688 | return r_sector; | ||
689 | } | ||
690 | |||
691 | |||
692 | |||
693 | /* | ||
694 | * Copy data between a page in the stripe cache, and one or more bion | ||
695 | * The page could align with the middle of the bio, or there could be | ||
696 | * several bion, each with several bio_vecs, which cover part of the page | ||
697 | * Multiple bion are linked together on bi_next. There may be extras | ||
698 | * at the end of this list. We ignore them. | ||
699 | */ | ||
700 | static void copy_data(int frombio, struct bio *bio, | ||
701 | struct page *page, | ||
702 | sector_t sector) | ||
703 | { | ||
704 | char *pa = page_address(page); | ||
705 | struct bio_vec *bvl; | ||
706 | int i; | ||
707 | int page_offset; | ||
708 | |||
709 | if (bio->bi_sector >= sector) | ||
710 | page_offset = (signed)(bio->bi_sector - sector) * 512; | ||
711 | else | ||
712 | page_offset = (signed)(sector - bio->bi_sector) * -512; | ||
713 | bio_for_each_segment(bvl, bio, i) { | ||
714 | int len = bio_iovec_idx(bio,i)->bv_len; | ||
715 | int clen; | ||
716 | int b_offset = 0; | ||
717 | |||
718 | if (page_offset < 0) { | ||
719 | b_offset = -page_offset; | ||
720 | page_offset += b_offset; | ||
721 | len -= b_offset; | ||
722 | } | ||
723 | |||
724 | if (len > 0 && page_offset + len > STRIPE_SIZE) | ||
725 | clen = STRIPE_SIZE - page_offset; | ||
726 | else clen = len; | ||
727 | |||
728 | if (clen > 0) { | ||
729 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | ||
730 | if (frombio) | ||
731 | memcpy(pa+page_offset, ba+b_offset, clen); | ||
732 | else | ||
733 | memcpy(ba+b_offset, pa+page_offset, clen); | ||
734 | __bio_kunmap_atomic(ba, KM_USER0); | ||
735 | } | ||
736 | if (clen < len) /* hit end of page */ | ||
737 | break; | ||
738 | page_offset += len; | ||
739 | } | ||
740 | } | ||
741 | |||
742 | #define check_xor() do { \ | ||
743 | if (count == MAX_XOR_BLOCKS) { \ | ||
744 | xor_block(count, STRIPE_SIZE, ptr); \ | ||
745 | count = 1; \ | ||
746 | } \ | ||
747 | } while(0) | ||
748 | |||
749 | /* Compute P and Q syndromes */ | ||
750 | static void compute_parity(struct stripe_head *sh, int method) | ||
751 | { | ||
752 | raid6_conf_t *conf = sh->raid_conf; | ||
753 | int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; | ||
754 | struct bio *chosen; | ||
755 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | ||
756 | void *ptrs[disks]; | ||
757 | |||
758 | qd_idx = raid6_next_disk(pd_idx, disks); | ||
759 | d0_idx = raid6_next_disk(qd_idx, disks); | ||
760 | |||
761 | PRINTK("compute_parity, stripe %llu, method %d\n", | ||
762 | (unsigned long long)sh->sector, method); | ||
763 | |||
764 | switch(method) { | ||
765 | case READ_MODIFY_WRITE: | ||
766 | BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ | ||
767 | case RECONSTRUCT_WRITE: | ||
768 | for (i= disks; i-- ;) | ||
769 | if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { | ||
770 | chosen = sh->dev[i].towrite; | ||
771 | sh->dev[i].towrite = NULL; | ||
772 | |||
773 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | ||
774 | wake_up(&conf->wait_for_overlap); | ||
775 | |||
776 | BUG_ON(sh->dev[i].written); | ||
777 | sh->dev[i].written = chosen; | ||
778 | } | ||
779 | break; | ||
780 | case CHECK_PARITY: | ||
781 | BUG(); /* Not implemented yet */ | ||
782 | } | ||
783 | |||
784 | for (i = disks; i--;) | ||
785 | if (sh->dev[i].written) { | ||
786 | sector_t sector = sh->dev[i].sector; | ||
787 | struct bio *wbi = sh->dev[i].written; | ||
788 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | ||
789 | copy_data(1, wbi, sh->dev[i].page, sector); | ||
790 | wbi = r5_next_bio(wbi, sector); | ||
791 | } | ||
792 | |||
793 | set_bit(R5_LOCKED, &sh->dev[i].flags); | ||
794 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | ||
795 | } | ||
796 | |||
797 | // switch(method) { | ||
798 | // case RECONSTRUCT_WRITE: | ||
799 | // case CHECK_PARITY: | ||
800 | // case UPDATE_PARITY: | ||
801 | /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ | ||
802 | /* FIX: Is this ordering of drives even remotely optimal? */ | ||
803 | count = 0; | ||
804 | i = d0_idx; | ||
805 | do { | ||
806 | ptrs[count++] = page_address(sh->dev[i].page); | ||
807 | if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | ||
808 | printk("block %d/%d not uptodate on parity calc\n", i,count); | ||
809 | i = raid6_next_disk(i, disks); | ||
810 | } while ( i != d0_idx ); | ||
811 | // break; | ||
812 | // } | ||
813 | |||
814 | raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); | ||
815 | |||
816 | switch(method) { | ||
817 | case RECONSTRUCT_WRITE: | ||
818 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | ||
819 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | ||
820 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | ||
821 | set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); | ||
822 | break; | ||
823 | case UPDATE_PARITY: | ||
824 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | ||
825 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); | ||
826 | break; | ||
827 | } | ||
828 | } | ||
829 | |||
830 | /* Compute one missing block */ | ||
831 | static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) | ||
832 | { | ||
833 | raid6_conf_t *conf = sh->raid_conf; | ||
834 | int i, count, disks = conf->raid_disks; | ||
835 | void *ptr[MAX_XOR_BLOCKS], *p; | ||
836 | int pd_idx = sh->pd_idx; | ||
837 | int qd_idx = raid6_next_disk(pd_idx, disks); | ||
838 | |||
839 | PRINTK("compute_block_1, stripe %llu, idx %d\n", | ||
840 | (unsigned long long)sh->sector, dd_idx); | ||
841 | |||
842 | if ( dd_idx == qd_idx ) { | ||
843 | /* We're actually computing the Q drive */ | ||
844 | compute_parity(sh, UPDATE_PARITY); | ||
845 | } else { | ||
846 | ptr[0] = page_address(sh->dev[dd_idx].page); | ||
847 | if (!nozero) memset(ptr[0], 0, STRIPE_SIZE); | ||
848 | count = 1; | ||
849 | for (i = disks ; i--; ) { | ||
850 | if (i == dd_idx || i == qd_idx) | ||
851 | continue; | ||
852 | p = page_address(sh->dev[i].page); | ||
853 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | ||
854 | ptr[count++] = p; | ||
855 | else | ||
856 | printk("compute_block() %d, stripe %llu, %d" | ||
857 | " not present\n", dd_idx, | ||
858 | (unsigned long long)sh->sector, i); | ||
859 | |||
860 | check_xor(); | ||
861 | } | ||
862 | if (count != 1) | ||
863 | xor_block(count, STRIPE_SIZE, ptr); | ||
864 | if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | ||
865 | else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | ||
866 | } | ||
867 | } | ||
868 | |||
869 | /* Compute two missing blocks */ | ||
870 | static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) | ||
871 | { | ||
872 | raid6_conf_t *conf = sh->raid_conf; | ||
873 | int i, count, disks = conf->raid_disks; | ||
874 | int pd_idx = sh->pd_idx; | ||
875 | int qd_idx = raid6_next_disk(pd_idx, disks); | ||
876 | int d0_idx = raid6_next_disk(qd_idx, disks); | ||
877 | int faila, failb; | ||
878 | |||
879 | /* faila and failb are disk numbers relative to d0_idx */ | ||
880 | /* pd_idx become disks-2 and qd_idx become disks-1 */ | ||
881 | faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; | ||
882 | failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; | ||
883 | |||
884 | BUG_ON(faila == failb); | ||
885 | if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } | ||
886 | |||
887 | PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", | ||
888 | (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); | ||
889 | |||
890 | if ( failb == disks-1 ) { | ||
891 | /* Q disk is one of the missing disks */ | ||
892 | if ( faila == disks-2 ) { | ||
893 | /* Missing P+Q, just recompute */ | ||
894 | compute_parity(sh, UPDATE_PARITY); | ||
895 | return; | ||
896 | } else { | ||
897 | /* We're missing D+Q; recompute D from P */ | ||
898 | compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); | ||
899 | compute_parity(sh, UPDATE_PARITY); /* Is this necessary? */ | ||
900 | return; | ||
901 | } | ||
902 | } | ||
903 | |||
904 | /* We're missing D+P or D+D; build pointer table */ | ||
905 | { | ||
906 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ | ||
907 | void *ptrs[disks]; | ||
908 | |||
909 | count = 0; | ||
910 | i = d0_idx; | ||
911 | do { | ||
912 | ptrs[count++] = page_address(sh->dev[i].page); | ||
913 | i = raid6_next_disk(i, disks); | ||
914 | if (i != dd_idx1 && i != dd_idx2 && | ||
915 | !test_bit(R5_UPTODATE, &sh->dev[i].flags)) | ||
916 | printk("compute_2 with missing block %d/%d\n", count, i); | ||
917 | } while ( i != d0_idx ); | ||
918 | |||
919 | if ( failb == disks-2 ) { | ||
920 | /* We're missing D+P. */ | ||
921 | raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); | ||
922 | } else { | ||
923 | /* We're missing D+D. */ | ||
924 | raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); | ||
925 | } | ||
926 | |||
927 | /* Both the above update both missing blocks */ | ||
928 | set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); | ||
929 | set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); | ||
930 | } | ||
931 | } | ||
932 | |||
933 | |||
934 | /* | ||
935 | * Each stripe/dev can have one or more bion attached. | ||
936 | * toread/towrite point to the first in a chain. | ||
937 | * The bi_next chain must be in order. | ||
938 | */ | ||
939 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | ||
940 | { | ||
941 | struct bio **bip; | ||
942 | raid6_conf_t *conf = sh->raid_conf; | ||
943 | int firstwrite=0; | ||
944 | |||
945 | PRINTK("adding bh b#%llu to stripe s#%llu\n", | ||
946 | (unsigned long long)bi->bi_sector, | ||
947 | (unsigned long long)sh->sector); | ||
948 | |||
949 | |||
950 | spin_lock(&sh->lock); | ||
951 | spin_lock_irq(&conf->device_lock); | ||
952 | if (forwrite) { | ||
953 | bip = &sh->dev[dd_idx].towrite; | ||
954 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) | ||
955 | firstwrite = 1; | ||
956 | } else | ||
957 | bip = &sh->dev[dd_idx].toread; | ||
958 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | ||
959 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | ||
960 | goto overlap; | ||
961 | bip = &(*bip)->bi_next; | ||
962 | } | ||
963 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | ||
964 | goto overlap; | ||
965 | |||
966 | BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); | ||
967 | if (*bip) | ||
968 | bi->bi_next = *bip; | ||
969 | *bip = bi; | ||
970 | bi->bi_phys_segments ++; | ||
971 | spin_unlock_irq(&conf->device_lock); | ||
972 | spin_unlock(&sh->lock); | ||
973 | |||
974 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", | ||
975 | (unsigned long long)bi->bi_sector, | ||
976 | (unsigned long long)sh->sector, dd_idx); | ||
977 | |||
978 | if (conf->mddev->bitmap && firstwrite) { | ||
979 | sh->bm_seq = conf->seq_write; | ||
980 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | ||
981 | STRIPE_SECTORS, 0); | ||
982 | set_bit(STRIPE_BIT_DELAY, &sh->state); | ||
983 | } | ||
984 | |||
985 | if (forwrite) { | ||
986 | /* check if page is covered */ | ||
987 | sector_t sector = sh->dev[dd_idx].sector; | ||
988 | for (bi=sh->dev[dd_idx].towrite; | ||
989 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | ||
990 | bi && bi->bi_sector <= sector; | ||
991 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | ||
992 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | ||
993 | sector = bi->bi_sector + (bi->bi_size>>9); | ||
994 | } | ||
995 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | ||
996 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | ||
997 | } | ||
998 | return 1; | ||
999 | |||
1000 | overlap: | ||
1001 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | ||
1002 | spin_unlock_irq(&conf->device_lock); | ||
1003 | spin_unlock(&sh->lock); | ||
1004 | return 0; | ||
1005 | } | ||
1006 | |||
1007 | |||
1008 | static int page_is_zero(struct page *p) | ||
1009 | { | ||
1010 | char *a = page_address(p); | ||
1011 | return ((*(u32*)a) == 0 && | ||
1012 | memcmp(a, a+4, STRIPE_SIZE-4)==0); | ||
1013 | } | ||
1014 | /* | ||
1015 | * handle_stripe - do things to a stripe. | ||
1016 | * | ||
1017 | * We lock the stripe and then examine the state of various bits | ||
1018 | * to see what needs to be done. | ||
1019 | * Possible results: | ||
1020 | * return some read request which now have data | ||
1021 | * return some write requests which are safely on disc | ||
1022 | * schedule a read on some buffers | ||
1023 | * schedule a write of some buffers | ||
1024 | * return confirmation of parity correctness | ||
1025 | * | ||
1026 | * Parity calculations are done inside the stripe lock | ||
1027 | * buffers are taken off read_list or write_list, and bh_cache buffers | ||
1028 | * get BH_Lock set before the stripe lock is released. | ||
1029 | * | ||
1030 | */ | ||
1031 | |||
1032 | static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) | ||
1033 | { | ||
1034 | raid6_conf_t *conf = sh->raid_conf; | ||
1035 | int disks = conf->raid_disks; | ||
1036 | struct bio *return_bi= NULL; | ||
1037 | struct bio *bi; | ||
1038 | int i; | ||
1039 | int syncing; | ||
1040 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; | ||
1041 | int non_overwrite = 0; | ||
1042 | int failed_num[2] = {0, 0}; | ||
1043 | struct r5dev *dev, *pdev, *qdev; | ||
1044 | int pd_idx = sh->pd_idx; | ||
1045 | int qd_idx = raid6_next_disk(pd_idx, disks); | ||
1046 | int p_failed, q_failed; | ||
1047 | |||
1048 | PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", | ||
1049 | (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), | ||
1050 | pd_idx, qd_idx); | ||
1051 | |||
1052 | spin_lock(&sh->lock); | ||
1053 | clear_bit(STRIPE_HANDLE, &sh->state); | ||
1054 | clear_bit(STRIPE_DELAYED, &sh->state); | ||
1055 | |||
1056 | syncing = test_bit(STRIPE_SYNCING, &sh->state); | ||
1057 | /* Now to look around and see what can be done */ | ||
1058 | |||
1059 | rcu_read_lock(); | ||
1060 | for (i=disks; i--; ) { | ||
1061 | mdk_rdev_t *rdev; | ||
1062 | dev = &sh->dev[i]; | ||
1063 | clear_bit(R5_Insync, &dev->flags); | ||
1064 | |||
1065 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", | ||
1066 | i, dev->flags, dev->toread, dev->towrite, dev->written); | ||
1067 | /* maybe we can reply to a read */ | ||
1068 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | ||
1069 | struct bio *rbi, *rbi2; | ||
1070 | PRINTK("Return read for disc %d\n", i); | ||
1071 | spin_lock_irq(&conf->device_lock); | ||
1072 | rbi = dev->toread; | ||
1073 | dev->toread = NULL; | ||
1074 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | ||
1075 | wake_up(&conf->wait_for_overlap); | ||
1076 | spin_unlock_irq(&conf->device_lock); | ||
1077 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | ||
1078 | copy_data(0, rbi, dev->page, dev->sector); | ||
1079 | rbi2 = r5_next_bio(rbi, dev->sector); | ||
1080 | spin_lock_irq(&conf->device_lock); | ||
1081 | if (--rbi->bi_phys_segments == 0) { | ||
1082 | rbi->bi_next = return_bi; | ||
1083 | return_bi = rbi; | ||
1084 | } | ||
1085 | spin_unlock_irq(&conf->device_lock); | ||
1086 | rbi = rbi2; | ||
1087 | } | ||
1088 | } | ||
1089 | |||
1090 | /* now count some things */ | ||
1091 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; | ||
1092 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; | ||
1093 | |||
1094 | |||
1095 | if (dev->toread) to_read++; | ||
1096 | if (dev->towrite) { | ||
1097 | to_write++; | ||
1098 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | ||
1099 | non_overwrite++; | ||
1100 | } | ||
1101 | if (dev->written) written++; | ||
1102 | rdev = rcu_dereference(conf->disks[i].rdev); | ||
1103 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { | ||
1104 | /* The ReadError flag will just be confusing now */ | ||
1105 | clear_bit(R5_ReadError, &dev->flags); | ||
1106 | clear_bit(R5_ReWrite, &dev->flags); | ||
1107 | } | ||
1108 | if (!rdev || !test_bit(In_sync, &rdev->flags) | ||
1109 | || test_bit(R5_ReadError, &dev->flags)) { | ||
1110 | if ( failed < 2 ) | ||
1111 | failed_num[failed] = i; | ||
1112 | failed++; | ||
1113 | } else | ||
1114 | set_bit(R5_Insync, &dev->flags); | ||
1115 | } | ||
1116 | rcu_read_unlock(); | ||
1117 | PRINTK("locked=%d uptodate=%d to_read=%d" | ||
1118 | " to_write=%d failed=%d failed_num=%d,%d\n", | ||
1119 | locked, uptodate, to_read, to_write, failed, | ||
1120 | failed_num[0], failed_num[1]); | ||
1121 | /* check if the array has lost >2 devices and, if so, some requests might | ||
1122 | * need to be failed | ||
1123 | */ | ||
1124 | if (failed > 2 && to_read+to_write+written) { | ||
1125 | for (i=disks; i--; ) { | ||
1126 | int bitmap_end = 0; | ||
1127 | |||
1128 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | ||
1129 | mdk_rdev_t *rdev; | ||
1130 | rcu_read_lock(); | ||
1131 | rdev = rcu_dereference(conf->disks[i].rdev); | ||
1132 | if (rdev && test_bit(In_sync, &rdev->flags)) | ||
1133 | /* multiple read failures in one stripe */ | ||
1134 | md_error(conf->mddev, rdev); | ||
1135 | rcu_read_unlock(); | ||
1136 | } | ||
1137 | |||
1138 | spin_lock_irq(&conf->device_lock); | ||
1139 | /* fail all writes first */ | ||
1140 | bi = sh->dev[i].towrite; | ||
1141 | sh->dev[i].towrite = NULL; | ||
1142 | if (bi) { to_write--; bitmap_end = 1; } | ||
1143 | |||
1144 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | ||
1145 | wake_up(&conf->wait_for_overlap); | ||
1146 | |||
1147 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | ||
1148 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | ||
1149 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | ||
1150 | if (--bi->bi_phys_segments == 0) { | ||
1151 | md_write_end(conf->mddev); | ||
1152 | bi->bi_next = return_bi; | ||
1153 | return_bi = bi; | ||
1154 | } | ||
1155 | bi = nextbi; | ||
1156 | } | ||
1157 | /* and fail all 'written' */ | ||
1158 | bi = sh->dev[i].written; | ||
1159 | sh->dev[i].written = NULL; | ||
1160 | if (bi) bitmap_end = 1; | ||
1161 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { | ||
1162 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | ||
1163 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | ||
1164 | if (--bi->bi_phys_segments == 0) { | ||
1165 | md_write_end(conf->mddev); | ||
1166 | bi->bi_next = return_bi; | ||
1167 | return_bi = bi; | ||
1168 | } | ||
1169 | bi = bi2; | ||
1170 | } | ||
1171 | |||
1172 | /* fail any reads if this device is non-operational */ | ||
1173 | if (!test_bit(R5_Insync, &sh->dev[i].flags) || | ||
1174 | test_bit(R5_ReadError, &sh->dev[i].flags)) { | ||
1175 | bi = sh->dev[i].toread; | ||
1176 | sh->dev[i].toread = NULL; | ||
1177 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | ||
1178 | wake_up(&conf->wait_for_overlap); | ||
1179 | if (bi) to_read--; | ||
1180 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | ||
1181 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | ||
1182 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | ||
1183 | if (--bi->bi_phys_segments == 0) { | ||
1184 | bi->bi_next = return_bi; | ||
1185 | return_bi = bi; | ||
1186 | } | ||
1187 | bi = nextbi; | ||
1188 | } | ||
1189 | } | ||
1190 | spin_unlock_irq(&conf->device_lock); | ||
1191 | if (bitmap_end) | ||
1192 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | ||
1193 | STRIPE_SECTORS, 0, 0); | ||
1194 | } | ||
1195 | } | ||
1196 | if (failed > 2 && syncing) { | ||
1197 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | ||
1198 | clear_bit(STRIPE_SYNCING, &sh->state); | ||
1199 | syncing = 0; | ||
1200 | } | ||
1201 | |||
1202 | /* | ||
1203 | * might be able to return some write requests if the parity blocks | ||
1204 | * are safe, or on a failed drive | ||
1205 | */ | ||
1206 | pdev = &sh->dev[pd_idx]; | ||
1207 | p_failed = (failed >= 1 && failed_num[0] == pd_idx) | ||
1208 | || (failed >= 2 && failed_num[1] == pd_idx); | ||
1209 | qdev = &sh->dev[qd_idx]; | ||
1210 | q_failed = (failed >= 1 && failed_num[0] == qd_idx) | ||
1211 | || (failed >= 2 && failed_num[1] == qd_idx); | ||
1212 | |||
1213 | if ( written && | ||
1214 | ( p_failed || ((test_bit(R5_Insync, &pdev->flags) | ||
1215 | && !test_bit(R5_LOCKED, &pdev->flags) | ||
1216 | && test_bit(R5_UPTODATE, &pdev->flags))) ) && | ||
1217 | ( q_failed || ((test_bit(R5_Insync, &qdev->flags) | ||
1218 | && !test_bit(R5_LOCKED, &qdev->flags) | ||
1219 | && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { | ||
1220 | /* any written block on an uptodate or failed drive can be | ||
1221 | * returned. Note that if we 'wrote' to a failed drive, | ||
1222 | * it will be UPTODATE, but never LOCKED, so we don't need | ||
1223 | * to test 'failed' directly. | ||
1224 | */ | ||
1225 | for (i=disks; i--; ) | ||
1226 | if (sh->dev[i].written) { | ||
1227 | dev = &sh->dev[i]; | ||
1228 | if (!test_bit(R5_LOCKED, &dev->flags) && | ||
1229 | test_bit(R5_UPTODATE, &dev->flags) ) { | ||
1230 | /* We can return any write requests */ | ||
1231 | int bitmap_end = 0; | ||
1232 | struct bio *wbi, *wbi2; | ||
1233 | PRINTK("Return write for stripe %llu disc %d\n", | ||
1234 | (unsigned long long)sh->sector, i); | ||
1235 | spin_lock_irq(&conf->device_lock); | ||
1236 | wbi = dev->written; | ||
1237 | dev->written = NULL; | ||
1238 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { | ||
1239 | wbi2 = r5_next_bio(wbi, dev->sector); | ||
1240 | if (--wbi->bi_phys_segments == 0) { | ||
1241 | md_write_end(conf->mddev); | ||
1242 | wbi->bi_next = return_bi; | ||
1243 | return_bi = wbi; | ||
1244 | } | ||
1245 | wbi = wbi2; | ||
1246 | } | ||
1247 | if (dev->towrite == NULL) | ||
1248 | bitmap_end = 1; | ||
1249 | spin_unlock_irq(&conf->device_lock); | ||
1250 | if (bitmap_end) | ||
1251 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | ||
1252 | STRIPE_SECTORS, | ||
1253 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); | ||
1254 | } | ||
1255 | } | ||
1256 | } | ||
1257 | |||
1258 | /* Now we might consider reading some blocks, either to check/generate | ||
1259 | * parity, or to satisfy requests | ||
1260 | * or to load a block that is being partially written. | ||
1261 | */ | ||
1262 | if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { | ||
1263 | for (i=disks; i--;) { | ||
1264 | dev = &sh->dev[i]; | ||
1265 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | ||
1266 | (dev->toread || | ||
1267 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | ||
1268 | syncing || | ||
1269 | (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || | ||
1270 | (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) | ||
1271 | ) | ||
1272 | ) { | ||
1273 | /* we would like to get this block, possibly | ||
1274 | * by computing it, but we might not be able to | ||
1275 | */ | ||
1276 | if (uptodate == disks-1) { | ||
1277 | PRINTK("Computing stripe %llu block %d\n", | ||
1278 | (unsigned long long)sh->sector, i); | ||
1279 | compute_block_1(sh, i, 0); | ||
1280 | uptodate++; | ||
1281 | } else if ( uptodate == disks-2 && failed >= 2 ) { | ||
1282 | /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ | ||
1283 | int other; | ||
1284 | for (other=disks; other--;) { | ||
1285 | if ( other == i ) | ||
1286 | continue; | ||
1287 | if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) | ||
1288 | break; | ||
1289 | } | ||
1290 | BUG_ON(other < 0); | ||
1291 | PRINTK("Computing stripe %llu blocks %d,%d\n", | ||
1292 | (unsigned long long)sh->sector, i, other); | ||
1293 | compute_block_2(sh, i, other); | ||
1294 | uptodate += 2; | ||
1295 | } else if (test_bit(R5_Insync, &dev->flags)) { | ||
1296 | set_bit(R5_LOCKED, &dev->flags); | ||
1297 | set_bit(R5_Wantread, &dev->flags); | ||
1298 | #if 0 | ||
1299 | /* if I am just reading this block and we don't have | ||
1300 | a failed drive, or any pending writes then sidestep the cache */ | ||
1301 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && | ||
1302 | ! syncing && !failed && !to_write) { | ||
1303 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; | ||
1304 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; | ||
1305 | } | ||
1306 | #endif | ||
1307 | locked++; | ||
1308 | PRINTK("Reading block %d (sync=%d)\n", | ||
1309 | i, syncing); | ||
1310 | } | ||
1311 | } | ||
1312 | } | ||
1313 | set_bit(STRIPE_HANDLE, &sh->state); | ||
1314 | } | ||
1315 | |||
1316 | /* now to consider writing and what else, if anything should be read */ | ||
1317 | if (to_write) { | ||
1318 | int rcw=0, must_compute=0; | ||
1319 | for (i=disks ; i--;) { | ||
1320 | dev = &sh->dev[i]; | ||
1321 | /* Would I have to read this buffer for reconstruct_write */ | ||
1322 | if (!test_bit(R5_OVERWRITE, &dev->flags) | ||
1323 | && i != pd_idx && i != qd_idx | ||
1324 | && (!test_bit(R5_LOCKED, &dev->flags) | ||
1325 | #if 0 | ||
1326 | || sh->bh_page[i] != bh->b_page | ||
1327 | #endif | ||
1328 | ) && | ||
1329 | !test_bit(R5_UPTODATE, &dev->flags)) { | ||
1330 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | ||
1331 | else { | ||
1332 | PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); | ||
1333 | must_compute++; | ||
1334 | } | ||
1335 | } | ||
1336 | } | ||
1337 | PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", | ||
1338 | (unsigned long long)sh->sector, rcw, must_compute); | ||
1339 | set_bit(STRIPE_HANDLE, &sh->state); | ||
1340 | |||
1341 | if (rcw > 0) | ||
1342 | /* want reconstruct write, but need to get some data */ | ||
1343 | for (i=disks; i--;) { | ||
1344 | dev = &sh->dev[i]; | ||
1345 | if (!test_bit(R5_OVERWRITE, &dev->flags) | ||
1346 | && !(failed == 0 && (i == pd_idx || i == qd_idx)) | ||
1347 | && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | ||
1348 | test_bit(R5_Insync, &dev->flags)) { | ||
1349 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | ||
1350 | { | ||
1351 | PRINTK("Read_old stripe %llu block %d for Reconstruct\n", | ||
1352 | (unsigned long long)sh->sector, i); | ||
1353 | set_bit(R5_LOCKED, &dev->flags); | ||
1354 | set_bit(R5_Wantread, &dev->flags); | ||
1355 | locked++; | ||
1356 | } else { | ||
1357 | PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", | ||
1358 | (unsigned long long)sh->sector, i); | ||
1359 | set_bit(STRIPE_DELAYED, &sh->state); | ||
1360 | set_bit(STRIPE_HANDLE, &sh->state); | ||
1361 | } | ||
1362 | } | ||
1363 | } | ||
1364 | /* now if nothing is locked, and if we have enough data, we can start a write request */ | ||
1365 | if (locked == 0 && rcw == 0 && | ||
1366 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | ||
1367 | if ( must_compute > 0 ) { | ||
1368 | /* We have failed blocks and need to compute them */ | ||
1369 | switch ( failed ) { | ||
1370 | case 0: BUG(); | ||
1371 | case 1: compute_block_1(sh, failed_num[0], 0); break; | ||
1372 | case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; | ||
1373 | default: BUG(); /* This request should have been failed? */ | ||
1374 | } | ||
1375 | } | ||
1376 | |||
1377 | PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); | ||
1378 | compute_parity(sh, RECONSTRUCT_WRITE); | ||
1379 | /* now every locked buffer is ready to be written */ | ||
1380 | for (i=disks; i--;) | ||
1381 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | ||
1382 | PRINTK("Writing stripe %llu block %d\n", | ||
1383 | (unsigned long long)sh->sector, i); | ||
1384 | locked++; | ||
1385 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | ||
1386 | } | ||
1387 | /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ | ||
1388 | set_bit(STRIPE_INSYNC, &sh->state); | ||
1389 | |||
1390 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | ||
1391 | atomic_dec(&conf->preread_active_stripes); | ||
1392 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | ||
1393 | md_wakeup_thread(conf->mddev->thread); | ||
1394 | } | ||
1395 | } | ||
1396 | } | ||
1397 | |||
1398 | /* maybe we need to check and possibly fix the parity for this stripe | ||
1399 | * Any reads will already have been scheduled, so we just see if enough data | ||
1400 | * is available | ||
1401 | */ | ||
1402 | if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) { | ||
1403 | int update_p = 0, update_q = 0; | ||
1404 | struct r5dev *dev; | ||
1405 | |||
1406 | set_bit(STRIPE_HANDLE, &sh->state); | ||
1407 | |||
1408 | BUG_ON(failed>2); | ||
1409 | BUG_ON(uptodate < disks); | ||
1410 | /* Want to check and possibly repair P and Q. | ||
1411 | * However there could be one 'failed' device, in which | ||
1412 | * case we can only check one of them, possibly using the | ||
1413 | * other to generate missing data | ||
1414 | */ | ||
1415 | |||
1416 | /* If !tmp_page, we cannot do the calculations, | ||
1417 | * but as we have set STRIPE_HANDLE, we will soon be called | ||
1418 | * by stripe_handle with a tmp_page - just wait until then. | ||
1419 | */ | ||
1420 | if (tmp_page) { | ||
1421 | if (failed == q_failed) { | ||
1422 | /* The only possible failed device holds 'Q', so it makes | ||
1423 | * sense to check P (If anything else were failed, we would | ||
1424 | * have used P to recreate it). | ||
1425 | */ | ||
1426 | compute_block_1(sh, pd_idx, 1); | ||
1427 | if (!page_is_zero(sh->dev[pd_idx].page)) { | ||
1428 | compute_block_1(sh,pd_idx,0); | ||
1429 | update_p = 1; | ||
1430 | } | ||
1431 | } | ||
1432 | if (!q_failed && failed < 2) { | ||
1433 | /* q is not failed, and we didn't use it to generate | ||
1434 | * anything, so it makes sense to check it | ||
1435 | */ | ||
1436 | memcpy(page_address(tmp_page), | ||
1437 | page_address(sh->dev[qd_idx].page), | ||
1438 | STRIPE_SIZE); | ||
1439 | compute_parity(sh, UPDATE_PARITY); | ||
1440 | if (memcmp(page_address(tmp_page), | ||
1441 | page_address(sh->dev[qd_idx].page), | ||
1442 | STRIPE_SIZE)!= 0) { | ||
1443 | clear_bit(STRIPE_INSYNC, &sh->state); | ||
1444 | update_q = 1; | ||
1445 | } | ||
1446 | } | ||
1447 | if (update_p || update_q) { | ||
1448 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | ||
1449 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | ||
1450 | /* don't try to repair!! */ | ||
1451 | update_p = update_q = 0; | ||
1452 | } | ||
1453 | |||
1454 | /* now write out any block on a failed drive, | ||
1455 | * or P or Q if they need it | ||
1456 | */ | ||
1457 | |||
1458 | if (failed == 2) { | ||
1459 | dev = &sh->dev[failed_num[1]]; | ||
1460 | locked++; | ||
1461 | set_bit(R5_LOCKED, &dev->flags); | ||
1462 | set_bit(R5_Wantwrite, &dev->flags); | ||
1463 | } | ||
1464 | if (failed >= 1) { | ||
1465 | dev = &sh->dev[failed_num[0]]; | ||
1466 | locked++; | ||
1467 | set_bit(R5_LOCKED, &dev->flags); | ||
1468 | set_bit(R5_Wantwrite, &dev->flags); | ||
1469 | } | ||
1470 | |||
1471 | if (update_p) { | ||
1472 | dev = &sh->dev[pd_idx]; | ||
1473 | locked ++; | ||
1474 | set_bit(R5_LOCKED, &dev->flags); | ||
1475 | set_bit(R5_Wantwrite, &dev->flags); | ||
1476 | } | ||
1477 | if (update_q) { | ||
1478 | dev = &sh->dev[qd_idx]; | ||
1479 | locked++; | ||
1480 | set_bit(R5_LOCKED, &dev->flags); | ||
1481 | set_bit(R5_Wantwrite, &dev->flags); | ||
1482 | } | ||
1483 | clear_bit(STRIPE_DEGRADED, &sh->state); | ||
1484 | |||
1485 | set_bit(STRIPE_INSYNC, &sh->state); | ||
1486 | } | ||
1487 | } | ||
1488 | |||
1489 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | ||
1490 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | ||
1491 | clear_bit(STRIPE_SYNCING, &sh->state); | ||
1492 | } | ||
1493 | |||
1494 | /* If the failed drives are just a ReadError, then we might need | ||
1495 | * to progress the repair/check process | ||
1496 | */ | ||
1497 | if (failed <= 2 && ! conf->mddev->ro) | ||
1498 | for (i=0; i<failed;i++) { | ||
1499 | dev = &sh->dev[failed_num[i]]; | ||
1500 | if (test_bit(R5_ReadError, &dev->flags) | ||
1501 | && !test_bit(R5_LOCKED, &dev->flags) | ||
1502 | && test_bit(R5_UPTODATE, &dev->flags) | ||
1503 | ) { | ||
1504 | if (!test_bit(R5_ReWrite, &dev->flags)) { | ||
1505 | set_bit(R5_Wantwrite, &dev->flags); | ||
1506 | set_bit(R5_ReWrite, &dev->flags); | ||
1507 | set_bit(R5_LOCKED, &dev->flags); | ||
1508 | } else { | ||
1509 | /* let's read it back */ | ||
1510 | set_bit(R5_Wantread, &dev->flags); | ||
1511 | set_bit(R5_LOCKED, &dev->flags); | ||
1512 | } | ||
1513 | } | ||
1514 | } | ||
1515 | spin_unlock(&sh->lock); | ||
1516 | |||
1517 | while ((bi=return_bi)) { | ||
1518 | int bytes = bi->bi_size; | ||
1519 | |||
1520 | return_bi = bi->bi_next; | ||
1521 | bi->bi_next = NULL; | ||
1522 | bi->bi_size = 0; | ||
1523 | bi->bi_end_io(bi, bytes, 0); | ||
1524 | } | ||
1525 | for (i=disks; i-- ;) { | ||
1526 | int rw; | ||
1527 | struct bio *bi; | ||
1528 | mdk_rdev_t *rdev; | ||
1529 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | ||
1530 | rw = 1; | ||
1531 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | ||
1532 | rw = 0; | ||
1533 | else | ||
1534 | continue; | ||
1535 | |||
1536 | bi = &sh->dev[i].req; | ||
1537 | |||
1538 | bi->bi_rw = rw; | ||
1539 | if (rw) | ||
1540 | bi->bi_end_io = raid6_end_write_request; | ||
1541 | else | ||
1542 | bi->bi_end_io = raid6_end_read_request; | ||
1543 | |||
1544 | rcu_read_lock(); | ||
1545 | rdev = rcu_dereference(conf->disks[i].rdev); | ||
1546 | if (rdev && test_bit(Faulty, &rdev->flags)) | ||
1547 | rdev = NULL; | ||
1548 | if (rdev) | ||
1549 | atomic_inc(&rdev->nr_pending); | ||
1550 | rcu_read_unlock(); | ||
1551 | |||
1552 | if (rdev) { | ||
1553 | if (syncing) | ||
1554 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); | ||
1555 | |||
1556 | bi->bi_bdev = rdev->bdev; | ||
1557 | PRINTK("for %llu schedule op %ld on disc %d\n", | ||
1558 | (unsigned long long)sh->sector, bi->bi_rw, i); | ||
1559 | atomic_inc(&sh->count); | ||
1560 | bi->bi_sector = sh->sector + rdev->data_offset; | ||
1561 | bi->bi_flags = 1 << BIO_UPTODATE; | ||
1562 | bi->bi_vcnt = 1; | ||
1563 | bi->bi_max_vecs = 1; | ||
1564 | bi->bi_idx = 0; | ||
1565 | bi->bi_io_vec = &sh->dev[i].vec; | ||
1566 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | ||
1567 | bi->bi_io_vec[0].bv_offset = 0; | ||
1568 | bi->bi_size = STRIPE_SIZE; | ||
1569 | bi->bi_next = NULL; | ||
1570 | if (rw == WRITE && | ||
1571 | test_bit(R5_ReWrite, &sh->dev[i].flags)) | ||
1572 | atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); | ||
1573 | generic_make_request(bi); | ||
1574 | } else { | ||
1575 | if (rw == 1) | ||
1576 | set_bit(STRIPE_DEGRADED, &sh->state); | ||
1577 | PRINTK("skip op %ld on disc %d for sector %llu\n", | ||
1578 | bi->bi_rw, i, (unsigned long long)sh->sector); | ||
1579 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | ||
1580 | set_bit(STRIPE_HANDLE, &sh->state); | ||
1581 | } | ||
1582 | } | ||
1583 | } | ||
1584 | |||
1585 | static void raid6_activate_delayed(raid6_conf_t *conf) | ||
1586 | { | ||
1587 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | ||
1588 | while (!list_empty(&conf->delayed_list)) { | ||
1589 | struct list_head *l = conf->delayed_list.next; | ||
1590 | struct stripe_head *sh; | ||
1591 | sh = list_entry(l, struct stripe_head, lru); | ||
1592 | list_del_init(l); | ||
1593 | clear_bit(STRIPE_DELAYED, &sh->state); | ||
1594 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | ||
1595 | atomic_inc(&conf->preread_active_stripes); | ||
1596 | list_add_tail(&sh->lru, &conf->handle_list); | ||
1597 | } | ||
1598 | } | ||
1599 | } | ||
1600 | |||
1601 | static void activate_bit_delay(raid6_conf_t *conf) | ||
1602 | { | ||
1603 | /* device_lock is held */ | ||
1604 | struct list_head head; | ||
1605 | list_add(&head, &conf->bitmap_list); | ||
1606 | list_del_init(&conf->bitmap_list); | ||
1607 | while (!list_empty(&head)) { | ||
1608 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | ||
1609 | list_del_init(&sh->lru); | ||
1610 | atomic_inc(&sh->count); | ||
1611 | __release_stripe(conf, sh); | ||
1612 | } | ||
1613 | } | ||
1614 | |||
1615 | static void unplug_slaves(mddev_t *mddev) | ||
1616 | { | ||
1617 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1618 | int i; | ||
1619 | |||
1620 | rcu_read_lock(); | ||
1621 | for (i=0; i<mddev->raid_disks; i++) { | ||
1622 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); | ||
1623 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { | ||
1624 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); | ||
1625 | |||
1626 | atomic_inc(&rdev->nr_pending); | ||
1627 | rcu_read_unlock(); | ||
1628 | |||
1629 | if (r_queue->unplug_fn) | ||
1630 | r_queue->unplug_fn(r_queue); | ||
1631 | |||
1632 | rdev_dec_pending(rdev, mddev); | ||
1633 | rcu_read_lock(); | ||
1634 | } | ||
1635 | } | ||
1636 | rcu_read_unlock(); | ||
1637 | } | ||
1638 | |||
1639 | static void raid6_unplug_device(request_queue_t *q) | ||
1640 | { | ||
1641 | mddev_t *mddev = q->queuedata; | ||
1642 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1643 | unsigned long flags; | ||
1644 | |||
1645 | spin_lock_irqsave(&conf->device_lock, flags); | ||
1646 | |||
1647 | if (blk_remove_plug(q)) { | ||
1648 | conf->seq_flush++; | ||
1649 | raid6_activate_delayed(conf); | ||
1650 | } | ||
1651 | md_wakeup_thread(mddev->thread); | ||
1652 | |||
1653 | spin_unlock_irqrestore(&conf->device_lock, flags); | ||
1654 | |||
1655 | unplug_slaves(mddev); | ||
1656 | } | ||
1657 | |||
1658 | static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk, | ||
1659 | sector_t *error_sector) | ||
1660 | { | ||
1661 | mddev_t *mddev = q->queuedata; | ||
1662 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1663 | int i, ret = 0; | ||
1664 | |||
1665 | rcu_read_lock(); | ||
1666 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | ||
1667 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); | ||
1668 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | ||
1669 | struct block_device *bdev = rdev->bdev; | ||
1670 | request_queue_t *r_queue = bdev_get_queue(bdev); | ||
1671 | |||
1672 | if (!r_queue->issue_flush_fn) | ||
1673 | ret = -EOPNOTSUPP; | ||
1674 | else { | ||
1675 | atomic_inc(&rdev->nr_pending); | ||
1676 | rcu_read_unlock(); | ||
1677 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | ||
1678 | error_sector); | ||
1679 | rdev_dec_pending(rdev, mddev); | ||
1680 | rcu_read_lock(); | ||
1681 | } | ||
1682 | } | ||
1683 | } | ||
1684 | rcu_read_unlock(); | ||
1685 | return ret; | ||
1686 | } | ||
1687 | |||
1688 | static inline void raid6_plug_device(raid6_conf_t *conf) | ||
1689 | { | ||
1690 | spin_lock_irq(&conf->device_lock); | ||
1691 | blk_plug_device(conf->mddev->queue); | ||
1692 | spin_unlock_irq(&conf->device_lock); | ||
1693 | } | ||
1694 | |||
1695 | static int make_request (request_queue_t *q, struct bio * bi) | ||
1696 | { | ||
1697 | mddev_t *mddev = q->queuedata; | ||
1698 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1699 | const unsigned int raid_disks = conf->raid_disks; | ||
1700 | const unsigned int data_disks = raid_disks - 2; | ||
1701 | unsigned int dd_idx, pd_idx; | ||
1702 | sector_t new_sector; | ||
1703 | sector_t logical_sector, last_sector; | ||
1704 | struct stripe_head *sh; | ||
1705 | const int rw = bio_data_dir(bi); | ||
1706 | |||
1707 | if (unlikely(bio_barrier(bi))) { | ||
1708 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); | ||
1709 | return 0; | ||
1710 | } | ||
1711 | |||
1712 | md_write_start(mddev, bi); | ||
1713 | |||
1714 | disk_stat_inc(mddev->gendisk, ios[rw]); | ||
1715 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | ||
1716 | |||
1717 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | ||
1718 | last_sector = bi->bi_sector + (bi->bi_size>>9); | ||
1719 | |||
1720 | bi->bi_next = NULL; | ||
1721 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | ||
1722 | |||
1723 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { | ||
1724 | DEFINE_WAIT(w); | ||
1725 | |||
1726 | new_sector = raid6_compute_sector(logical_sector, | ||
1727 | raid_disks, data_disks, &dd_idx, &pd_idx, conf); | ||
1728 | |||
1729 | PRINTK("raid6: make_request, sector %llu logical %llu\n", | ||
1730 | (unsigned long long)new_sector, | ||
1731 | (unsigned long long)logical_sector); | ||
1732 | |||
1733 | retry: | ||
1734 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); | ||
1735 | sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); | ||
1736 | if (sh) { | ||
1737 | if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | ||
1738 | /* Add failed due to overlap. Flush everything | ||
1739 | * and wait a while | ||
1740 | */ | ||
1741 | raid6_unplug_device(mddev->queue); | ||
1742 | release_stripe(sh); | ||
1743 | schedule(); | ||
1744 | goto retry; | ||
1745 | } | ||
1746 | finish_wait(&conf->wait_for_overlap, &w); | ||
1747 | raid6_plug_device(conf); | ||
1748 | handle_stripe(sh, NULL); | ||
1749 | release_stripe(sh); | ||
1750 | } else { | ||
1751 | /* cannot get stripe for read-ahead, just give-up */ | ||
1752 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | ||
1753 | finish_wait(&conf->wait_for_overlap, &w); | ||
1754 | break; | ||
1755 | } | ||
1756 | |||
1757 | } | ||
1758 | spin_lock_irq(&conf->device_lock); | ||
1759 | if (--bi->bi_phys_segments == 0) { | ||
1760 | int bytes = bi->bi_size; | ||
1761 | |||
1762 | if (rw == WRITE ) | ||
1763 | md_write_end(mddev); | ||
1764 | bi->bi_size = 0; | ||
1765 | bi->bi_end_io(bi, bytes, 0); | ||
1766 | } | ||
1767 | spin_unlock_irq(&conf->device_lock); | ||
1768 | return 0; | ||
1769 | } | ||
1770 | |||
1771 | /* FIXME go_faster isn't used */ | ||
1772 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) | ||
1773 | { | ||
1774 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | ||
1775 | struct stripe_head *sh; | ||
1776 | int sectors_per_chunk = conf->chunk_size >> 9; | ||
1777 | sector_t x; | ||
1778 | unsigned long stripe; | ||
1779 | int chunk_offset; | ||
1780 | int dd_idx, pd_idx; | ||
1781 | sector_t first_sector; | ||
1782 | int raid_disks = conf->raid_disks; | ||
1783 | int data_disks = raid_disks - 2; | ||
1784 | sector_t max_sector = mddev->size << 1; | ||
1785 | int sync_blocks; | ||
1786 | int still_degraded = 0; | ||
1787 | int i; | ||
1788 | |||
1789 | if (sector_nr >= max_sector) { | ||
1790 | /* just being told to finish up .. nothing much to do */ | ||
1791 | unplug_slaves(mddev); | ||
1792 | |||
1793 | if (mddev->curr_resync < max_sector) /* aborted */ | ||
1794 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | ||
1795 | &sync_blocks, 1); | ||
1796 | else /* completed sync */ | ||
1797 | conf->fullsync = 0; | ||
1798 | bitmap_close_sync(mddev->bitmap); | ||
1799 | |||
1800 | return 0; | ||
1801 | } | ||
1802 | /* if there are 2 or more failed drives and we are trying | ||
1803 | * to resync, then assert that we are finished, because there is | ||
1804 | * nothing we can do. | ||
1805 | */ | ||
1806 | if (mddev->degraded >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | ||
1807 | sector_t rv = (mddev->size << 1) - sector_nr; | ||
1808 | *skipped = 1; | ||
1809 | return rv; | ||
1810 | } | ||
1811 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && | ||
1812 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && | ||
1813 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { | ||
1814 | /* we can skip this block, and probably more */ | ||
1815 | sync_blocks /= STRIPE_SECTORS; | ||
1816 | *skipped = 1; | ||
1817 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | ||
1818 | } | ||
1819 | |||
1820 | x = sector_nr; | ||
1821 | chunk_offset = sector_div(x, sectors_per_chunk); | ||
1822 | stripe = x; | ||
1823 | BUG_ON(x != stripe); | ||
1824 | |||
1825 | first_sector = raid6_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk | ||
1826 | + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); | ||
1827 | sh = get_active_stripe(conf, sector_nr, pd_idx, 1); | ||
1828 | if (sh == NULL) { | ||
1829 | sh = get_active_stripe(conf, sector_nr, pd_idx, 0); | ||
1830 | /* make sure we don't swamp the stripe cache if someone else | ||
1831 | * is trying to get access | ||
1832 | */ | ||
1833 | schedule_timeout_uninterruptible(1); | ||
1834 | } | ||
1835 | /* Need to check if array will still be degraded after recovery/resync | ||
1836 | * We don't need to check the 'failed' flag as when that gets set, | ||
1837 | * recovery aborts. | ||
1838 | */ | ||
1839 | for (i=0; i<mddev->raid_disks; i++) | ||
1840 | if (conf->disks[i].rdev == NULL) | ||
1841 | still_degraded = 1; | ||
1842 | |||
1843 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); | ||
1844 | |||
1845 | spin_lock(&sh->lock); | ||
1846 | set_bit(STRIPE_SYNCING, &sh->state); | ||
1847 | clear_bit(STRIPE_INSYNC, &sh->state); | ||
1848 | spin_unlock(&sh->lock); | ||
1849 | |||
1850 | handle_stripe(sh, NULL); | ||
1851 | release_stripe(sh); | ||
1852 | |||
1853 | return STRIPE_SECTORS; | ||
1854 | } | ||
1855 | |||
1856 | /* | ||
1857 | * This is our raid6 kernel thread. | ||
1858 | * | ||
1859 | * We scan the hash table for stripes which can be handled now. | ||
1860 | * During the scan, completed stripes are saved for us by the interrupt | ||
1861 | * handler, so that they will not have to wait for our next wakeup. | ||
1862 | */ | ||
1863 | static void raid6d (mddev_t *mddev) | ||
1864 | { | ||
1865 | struct stripe_head *sh; | ||
1866 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1867 | int handled; | ||
1868 | |||
1869 | PRINTK("+++ raid6d active\n"); | ||
1870 | |||
1871 | md_check_recovery(mddev); | ||
1872 | |||
1873 | handled = 0; | ||
1874 | spin_lock_irq(&conf->device_lock); | ||
1875 | while (1) { | ||
1876 | struct list_head *first; | ||
1877 | |||
1878 | if (conf->seq_flush - conf->seq_write > 0) { | ||
1879 | int seq = conf->seq_flush; | ||
1880 | spin_unlock_irq(&conf->device_lock); | ||
1881 | bitmap_unplug(mddev->bitmap); | ||
1882 | spin_lock_irq(&conf->device_lock); | ||
1883 | conf->seq_write = seq; | ||
1884 | activate_bit_delay(conf); | ||
1885 | } | ||
1886 | |||
1887 | if (list_empty(&conf->handle_list) && | ||
1888 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && | ||
1889 | !blk_queue_plugged(mddev->queue) && | ||
1890 | !list_empty(&conf->delayed_list)) | ||
1891 | raid6_activate_delayed(conf); | ||
1892 | |||
1893 | if (list_empty(&conf->handle_list)) | ||
1894 | break; | ||
1895 | |||
1896 | first = conf->handle_list.next; | ||
1897 | sh = list_entry(first, struct stripe_head, lru); | ||
1898 | |||
1899 | list_del_init(first); | ||
1900 | atomic_inc(&sh->count); | ||
1901 | BUG_ON(atomic_read(&sh->count)!= 1); | ||
1902 | spin_unlock_irq(&conf->device_lock); | ||
1903 | |||
1904 | handled++; | ||
1905 | handle_stripe(sh, conf->spare_page); | ||
1906 | release_stripe(sh); | ||
1907 | |||
1908 | spin_lock_irq(&conf->device_lock); | ||
1909 | } | ||
1910 | PRINTK("%d stripes handled\n", handled); | ||
1911 | |||
1912 | spin_unlock_irq(&conf->device_lock); | ||
1913 | |||
1914 | unplug_slaves(mddev); | ||
1915 | |||
1916 | PRINTK("--- raid6d inactive\n"); | ||
1917 | } | ||
1918 | |||
1919 | static ssize_t | ||
1920 | raid6_show_stripe_cache_size(mddev_t *mddev, char *page) | ||
1921 | { | ||
1922 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1923 | if (conf) | ||
1924 | return sprintf(page, "%d\n", conf->max_nr_stripes); | ||
1925 | else | ||
1926 | return 0; | ||
1927 | } | ||
1928 | |||
1929 | static ssize_t | ||
1930 | raid6_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) | ||
1931 | { | ||
1932 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1933 | char *end; | ||
1934 | int new; | ||
1935 | if (len >= PAGE_SIZE) | ||
1936 | return -EINVAL; | ||
1937 | if (!conf) | ||
1938 | return -ENODEV; | ||
1939 | |||
1940 | new = simple_strtoul(page, &end, 10); | ||
1941 | if (!*page || (*end && *end != '\n') ) | ||
1942 | return -EINVAL; | ||
1943 | if (new <= 16 || new > 32768) | ||
1944 | return -EINVAL; | ||
1945 | while (new < conf->max_nr_stripes) { | ||
1946 | if (drop_one_stripe(conf)) | ||
1947 | conf->max_nr_stripes--; | ||
1948 | else | ||
1949 | break; | ||
1950 | } | ||
1951 | while (new > conf->max_nr_stripes) { | ||
1952 | if (grow_one_stripe(conf)) | ||
1953 | conf->max_nr_stripes++; | ||
1954 | else break; | ||
1955 | } | ||
1956 | return len; | ||
1957 | } | ||
1958 | |||
1959 | static struct md_sysfs_entry | ||
1960 | raid6_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, | ||
1961 | raid6_show_stripe_cache_size, | ||
1962 | raid6_store_stripe_cache_size); | ||
1963 | |||
1964 | static ssize_t | ||
1965 | stripe_cache_active_show(mddev_t *mddev, char *page) | ||
1966 | { | ||
1967 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
1968 | if (conf) | ||
1969 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); | ||
1970 | else | ||
1971 | return 0; | ||
1972 | } | ||
1973 | |||
1974 | static struct md_sysfs_entry | ||
1975 | raid6_stripecache_active = __ATTR_RO(stripe_cache_active); | ||
1976 | |||
1977 | static struct attribute *raid6_attrs[] = { | ||
1978 | &raid6_stripecache_size.attr, | ||
1979 | &raid6_stripecache_active.attr, | ||
1980 | NULL, | ||
1981 | }; | ||
1982 | static struct attribute_group raid6_attrs_group = { | ||
1983 | .name = NULL, | ||
1984 | .attrs = raid6_attrs, | ||
1985 | }; | ||
1986 | |||
1987 | static int run(mddev_t *mddev) | ||
1988 | { | ||
1989 | raid6_conf_t *conf; | ||
1990 | int raid_disk, memory; | ||
1991 | mdk_rdev_t *rdev; | ||
1992 | struct disk_info *disk; | ||
1993 | struct list_head *tmp; | ||
1994 | |||
1995 | if (mddev->level != 6) { | ||
1996 | PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level); | ||
1997 | return -EIO; | ||
1998 | } | ||
1999 | |||
2000 | mddev->private = kzalloc(sizeof (raid6_conf_t), GFP_KERNEL); | ||
2001 | if ((conf = mddev->private) == NULL) | ||
2002 | goto abort; | ||
2003 | conf->disks = kzalloc(mddev->raid_disks * sizeof(struct disk_info), | ||
2004 | GFP_KERNEL); | ||
2005 | if (!conf->disks) | ||
2006 | goto abort; | ||
2007 | |||
2008 | conf->mddev = mddev; | ||
2009 | |||
2010 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) | ||
2011 | goto abort; | ||
2012 | |||
2013 | conf->spare_page = alloc_page(GFP_KERNEL); | ||
2014 | if (!conf->spare_page) | ||
2015 | goto abort; | ||
2016 | |||
2017 | spin_lock_init(&conf->device_lock); | ||
2018 | init_waitqueue_head(&conf->wait_for_stripe); | ||
2019 | init_waitqueue_head(&conf->wait_for_overlap); | ||
2020 | INIT_LIST_HEAD(&conf->handle_list); | ||
2021 | INIT_LIST_HEAD(&conf->delayed_list); | ||
2022 | INIT_LIST_HEAD(&conf->bitmap_list); | ||
2023 | INIT_LIST_HEAD(&conf->inactive_list); | ||
2024 | atomic_set(&conf->active_stripes, 0); | ||
2025 | atomic_set(&conf->preread_active_stripes, 0); | ||
2026 | |||
2027 | PRINTK("raid6: run(%s) called.\n", mdname(mddev)); | ||
2028 | |||
2029 | ITERATE_RDEV(mddev,rdev,tmp) { | ||
2030 | raid_disk = rdev->raid_disk; | ||
2031 | if (raid_disk >= mddev->raid_disks | ||
2032 | || raid_disk < 0) | ||
2033 | continue; | ||
2034 | disk = conf->disks + raid_disk; | ||
2035 | |||
2036 | disk->rdev = rdev; | ||
2037 | |||
2038 | if (test_bit(In_sync, &rdev->flags)) { | ||
2039 | char b[BDEVNAME_SIZE]; | ||
2040 | printk(KERN_INFO "raid6: device %s operational as raid" | ||
2041 | " disk %d\n", bdevname(rdev->bdev,b), | ||
2042 | raid_disk); | ||
2043 | conf->working_disks++; | ||
2044 | } | ||
2045 | } | ||
2046 | |||
2047 | conf->raid_disks = mddev->raid_disks; | ||
2048 | |||
2049 | /* | ||
2050 | * 0 for a fully functional array, 1 or 2 for a degraded array. | ||
2051 | */ | ||
2052 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; | ||
2053 | conf->mddev = mddev; | ||
2054 | conf->chunk_size = mddev->chunk_size; | ||
2055 | conf->level = mddev->level; | ||
2056 | conf->algorithm = mddev->layout; | ||
2057 | conf->max_nr_stripes = NR_STRIPES; | ||
2058 | |||
2059 | /* device size must be a multiple of chunk size */ | ||
2060 | mddev->size &= ~(mddev->chunk_size/1024 -1); | ||
2061 | mddev->resync_max_sectors = mddev->size << 1; | ||
2062 | |||
2063 | if (conf->raid_disks < 4) { | ||
2064 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", | ||
2065 | mdname(mddev), conf->raid_disks); | ||
2066 | goto abort; | ||
2067 | } | ||
2068 | if (!conf->chunk_size || conf->chunk_size % 4) { | ||
2069 | printk(KERN_ERR "raid6: invalid chunk size %d for %s\n", | ||
2070 | conf->chunk_size, mdname(mddev)); | ||
2071 | goto abort; | ||
2072 | } | ||
2073 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | ||
2074 | printk(KERN_ERR | ||
2075 | "raid6: unsupported parity algorithm %d for %s\n", | ||
2076 | conf->algorithm, mdname(mddev)); | ||
2077 | goto abort; | ||
2078 | } | ||
2079 | if (mddev->degraded > 2) { | ||
2080 | printk(KERN_ERR "raid6: not enough operational devices for %s" | ||
2081 | " (%d/%d failed)\n", | ||
2082 | mdname(mddev), conf->failed_disks, conf->raid_disks); | ||
2083 | goto abort; | ||
2084 | } | ||
2085 | |||
2086 | if (mddev->degraded > 0 && | ||
2087 | mddev->recovery_cp != MaxSector) { | ||
2088 | if (mddev->ok_start_degraded) | ||
2089 | printk(KERN_WARNING "raid6: starting dirty degraded array:%s" | ||
2090 | "- data corruption possible.\n", | ||
2091 | mdname(mddev)); | ||
2092 | else { | ||
2093 | printk(KERN_ERR "raid6: cannot start dirty degraded array" | ||
2094 | " for %s\n", mdname(mddev)); | ||
2095 | goto abort; | ||
2096 | } | ||
2097 | } | ||
2098 | |||
2099 | { | ||
2100 | mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6"); | ||
2101 | if (!mddev->thread) { | ||
2102 | printk(KERN_ERR | ||
2103 | "raid6: couldn't allocate thread for %s\n", | ||
2104 | mdname(mddev)); | ||
2105 | goto abort; | ||
2106 | } | ||
2107 | } | ||
2108 | |||
2109 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + | ||
2110 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; | ||
2111 | if (grow_stripes(conf, conf->max_nr_stripes)) { | ||
2112 | printk(KERN_ERR | ||
2113 | "raid6: couldn't allocate %dkB for buffers\n", memory); | ||
2114 | shrink_stripes(conf); | ||
2115 | md_unregister_thread(mddev->thread); | ||
2116 | goto abort; | ||
2117 | } else | ||
2118 | printk(KERN_INFO "raid6: allocated %dkB for %s\n", | ||
2119 | memory, mdname(mddev)); | ||
2120 | |||
2121 | if (mddev->degraded == 0) | ||
2122 | printk(KERN_INFO "raid6: raid level %d set %s active with %d out of %d" | ||
2123 | " devices, algorithm %d\n", conf->level, mdname(mddev), | ||
2124 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | ||
2125 | conf->algorithm); | ||
2126 | else | ||
2127 | printk(KERN_ALERT "raid6: raid level %d set %s active with %d" | ||
2128 | " out of %d devices, algorithm %d\n", conf->level, | ||
2129 | mdname(mddev), mddev->raid_disks - mddev->degraded, | ||
2130 | mddev->raid_disks, conf->algorithm); | ||
2131 | |||
2132 | print_raid6_conf(conf); | ||
2133 | |||
2134 | /* read-ahead size must cover two whole stripes, which is | ||
2135 | * 2 * (n-2) * chunksize where 'n' is the number of raid devices | ||
2136 | */ | ||
2137 | { | ||
2138 | int stripe = (mddev->raid_disks-2) * mddev->chunk_size | ||
2139 | / PAGE_SIZE; | ||
2140 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) | ||
2141 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | ||
2142 | } | ||
2143 | |||
2144 | /* Ok, everything is just fine now */ | ||
2145 | sysfs_create_group(&mddev->kobj, &raid6_attrs_group); | ||
2146 | |||
2147 | mddev->array_size = mddev->size * (mddev->raid_disks - 2); | ||
2148 | |||
2149 | mddev->queue->unplug_fn = raid6_unplug_device; | ||
2150 | mddev->queue->issue_flush_fn = raid6_issue_flush; | ||
2151 | return 0; | ||
2152 | abort: | ||
2153 | if (conf) { | ||
2154 | print_raid6_conf(conf); | ||
2155 | safe_put_page(conf->spare_page); | ||
2156 | kfree(conf->stripe_hashtbl); | ||
2157 | kfree(conf->disks); | ||
2158 | kfree(conf); | ||
2159 | } | ||
2160 | mddev->private = NULL; | ||
2161 | printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev)); | ||
2162 | return -EIO; | ||
2163 | } | ||
2164 | |||
2165 | |||
2166 | |||
2167 | static int stop (mddev_t *mddev) | ||
2168 | { | ||
2169 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | ||
2170 | |||
2171 | md_unregister_thread(mddev->thread); | ||
2172 | mddev->thread = NULL; | ||
2173 | shrink_stripes(conf); | ||
2174 | kfree(conf->stripe_hashtbl); | ||
2175 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | ||
2176 | sysfs_remove_group(&mddev->kobj, &raid6_attrs_group); | ||
2177 | kfree(conf); | ||
2178 | mddev->private = NULL; | ||
2179 | return 0; | ||
2180 | } | ||
2181 | |||
2182 | #if RAID6_DUMPSTATE | ||
2183 | static void print_sh (struct seq_file *seq, struct stripe_head *sh) | ||
2184 | { | ||
2185 | int i; | ||
2186 | |||
2187 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", | ||
2188 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | ||
2189 | seq_printf(seq, "sh %llu, count %d.\n", | ||
2190 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | ||
2191 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); | ||
2192 | for (i = 0; i < sh->raid_conf->raid_disks; i++) { | ||
2193 | seq_printf(seq, "(cache%d: %p %ld) ", | ||
2194 | i, sh->dev[i].page, sh->dev[i].flags); | ||
2195 | } | ||
2196 | seq_printf(seq, "\n"); | ||
2197 | } | ||
2198 | |||
2199 | static void printall (struct seq_file *seq, raid6_conf_t *conf) | ||
2200 | { | ||
2201 | struct stripe_head *sh; | ||
2202 | struct hlist_node *hn; | ||
2203 | int i; | ||
2204 | |||
2205 | spin_lock_irq(&conf->device_lock); | ||
2206 | for (i = 0; i < NR_HASH; i++) { | ||
2207 | sh = conf->stripe_hashtbl[i]; | ||
2208 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { | ||
2209 | if (sh->raid_conf != conf) | ||
2210 | continue; | ||
2211 | print_sh(seq, sh); | ||
2212 | } | ||
2213 | } | ||
2214 | spin_unlock_irq(&conf->device_lock); | ||
2215 | } | ||
2216 | #endif | ||
2217 | |||
2218 | static void status (struct seq_file *seq, mddev_t *mddev) | ||
2219 | { | ||
2220 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; | ||
2221 | int i; | ||
2222 | |||
2223 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | ||
2224 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); | ||
2225 | for (i = 0; i < conf->raid_disks; i++) | ||
2226 | seq_printf (seq, "%s", | ||
2227 | conf->disks[i].rdev && | ||
2228 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); | ||
2229 | seq_printf (seq, "]"); | ||
2230 | #if RAID6_DUMPSTATE | ||
2231 | seq_printf (seq, "\n"); | ||
2232 | printall(seq, conf); | ||
2233 | #endif | ||
2234 | } | ||
2235 | |||
2236 | static void print_raid6_conf (raid6_conf_t *conf) | ||
2237 | { | ||
2238 | int i; | ||
2239 | struct disk_info *tmp; | ||
2240 | |||
2241 | printk("RAID6 conf printout:\n"); | ||
2242 | if (!conf) { | ||
2243 | printk("(conf==NULL)\n"); | ||
2244 | return; | ||
2245 | } | ||
2246 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, | ||
2247 | conf->working_disks, conf->failed_disks); | ||
2248 | |||
2249 | for (i = 0; i < conf->raid_disks; i++) { | ||
2250 | char b[BDEVNAME_SIZE]; | ||
2251 | tmp = conf->disks + i; | ||
2252 | if (tmp->rdev) | ||
2253 | printk(" disk %d, o:%d, dev:%s\n", | ||
2254 | i, !test_bit(Faulty, &tmp->rdev->flags), | ||
2255 | bdevname(tmp->rdev->bdev,b)); | ||
2256 | } | ||
2257 | } | ||
2258 | |||
2259 | static int raid6_spare_active(mddev_t *mddev) | ||
2260 | { | ||
2261 | int i; | ||
2262 | raid6_conf_t *conf = mddev->private; | ||
2263 | struct disk_info *tmp; | ||
2264 | |||
2265 | for (i = 0; i < conf->raid_disks; i++) { | ||
2266 | tmp = conf->disks + i; | ||
2267 | if (tmp->rdev | ||
2268 | && !test_bit(Faulty, &tmp->rdev->flags) | ||
2269 | && !test_bit(In_sync, &tmp->rdev->flags)) { | ||
2270 | mddev->degraded--; | ||
2271 | conf->failed_disks--; | ||
2272 | conf->working_disks++; | ||
2273 | set_bit(In_sync, &tmp->rdev->flags); | ||
2274 | } | ||
2275 | } | ||
2276 | print_raid6_conf(conf); | ||
2277 | return 0; | ||
2278 | } | ||
2279 | |||
2280 | static int raid6_remove_disk(mddev_t *mddev, int number) | ||
2281 | { | ||
2282 | raid6_conf_t *conf = mddev->private; | ||
2283 | int err = 0; | ||
2284 | mdk_rdev_t *rdev; | ||
2285 | struct disk_info *p = conf->disks + number; | ||
2286 | |||
2287 | print_raid6_conf(conf); | ||
2288 | rdev = p->rdev; | ||
2289 | if (rdev) { | ||
2290 | if (test_bit(In_sync, &rdev->flags) || | ||
2291 | atomic_read(&rdev->nr_pending)) { | ||
2292 | err = -EBUSY; | ||
2293 | goto abort; | ||
2294 | } | ||
2295 | p->rdev = NULL; | ||
2296 | synchronize_rcu(); | ||
2297 | if (atomic_read(&rdev->nr_pending)) { | ||
2298 | /* lost the race, try later */ | ||
2299 | err = -EBUSY; | ||
2300 | p->rdev = rdev; | ||
2301 | } | ||
2302 | } | ||
2303 | |||
2304 | abort: | ||
2305 | |||
2306 | print_raid6_conf(conf); | ||
2307 | return err; | ||
2308 | } | ||
2309 | |||
2310 | static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | ||
2311 | { | ||
2312 | raid6_conf_t *conf = mddev->private; | ||
2313 | int found = 0; | ||
2314 | int disk; | ||
2315 | struct disk_info *p; | ||
2316 | |||
2317 | if (mddev->degraded > 2) | ||
2318 | /* no point adding a device */ | ||
2319 | return 0; | ||
2320 | /* | ||
2321 | * find the disk ... but prefer rdev->saved_raid_disk | ||
2322 | * if possible. | ||
2323 | */ | ||
2324 | if (rdev->saved_raid_disk >= 0 && | ||
2325 | conf->disks[rdev->saved_raid_disk].rdev == NULL) | ||
2326 | disk = rdev->saved_raid_disk; | ||
2327 | else | ||
2328 | disk = 0; | ||
2329 | for ( ; disk < mddev->raid_disks; disk++) | ||
2330 | if ((p=conf->disks + disk)->rdev == NULL) { | ||
2331 | clear_bit(In_sync, &rdev->flags); | ||
2332 | rdev->raid_disk = disk; | ||
2333 | found = 1; | ||
2334 | if (rdev->saved_raid_disk != disk) | ||
2335 | conf->fullsync = 1; | ||
2336 | rcu_assign_pointer(p->rdev, rdev); | ||
2337 | break; | ||
2338 | } | ||
2339 | print_raid6_conf(conf); | ||
2340 | return found; | ||
2341 | } | ||
2342 | |||
2343 | static int raid6_resize(mddev_t *mddev, sector_t sectors) | ||
2344 | { | ||
2345 | /* no resync is happening, and there is enough space | ||
2346 | * on all devices, so we can resize. | ||
2347 | * We need to make sure resync covers any new space. | ||
2348 | * If the array is shrinking we should possibly wait until | ||
2349 | * any io in the removed space completes, but it hardly seems | ||
2350 | * worth it. | ||
2351 | */ | ||
2352 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | ||
2353 | mddev->array_size = (sectors * (mddev->raid_disks-2))>>1; | ||
2354 | set_capacity(mddev->gendisk, mddev->array_size << 1); | ||
2355 | mddev->changed = 1; | ||
2356 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | ||
2357 | mddev->recovery_cp = mddev->size << 1; | ||
2358 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | ||
2359 | } | ||
2360 | mddev->size = sectors /2; | ||
2361 | mddev->resync_max_sectors = sectors; | ||
2362 | return 0; | ||
2363 | } | ||
2364 | |||
2365 | static void raid6_quiesce(mddev_t *mddev, int state) | ||
2366 | { | ||
2367 | raid6_conf_t *conf = mddev_to_conf(mddev); | ||
2368 | |||
2369 | switch(state) { | ||
2370 | case 1: /* stop all writes */ | ||
2371 | spin_lock_irq(&conf->device_lock); | ||
2372 | conf->quiesce = 1; | ||
2373 | wait_event_lock_irq(conf->wait_for_stripe, | ||
2374 | atomic_read(&conf->active_stripes) == 0, | ||
2375 | conf->device_lock, /* nothing */); | ||
2376 | spin_unlock_irq(&conf->device_lock); | ||
2377 | break; | ||
2378 | |||
2379 | case 0: /* re-enable writes */ | ||
2380 | spin_lock_irq(&conf->device_lock); | ||
2381 | conf->quiesce = 0; | ||
2382 | wake_up(&conf->wait_for_stripe); | ||
2383 | spin_unlock_irq(&conf->device_lock); | ||
2384 | break; | ||
2385 | } | ||
2386 | } | ||
2387 | |||
2388 | static struct mdk_personality raid6_personality = | ||
2389 | { | ||
2390 | .name = "raid6", | ||
2391 | .level = 6, | ||
2392 | .owner = THIS_MODULE, | ||
2393 | .make_request = make_request, | ||
2394 | .run = run, | ||
2395 | .stop = stop, | ||
2396 | .status = status, | ||
2397 | .error_handler = error, | ||
2398 | .hot_add_disk = raid6_add_disk, | ||
2399 | .hot_remove_disk= raid6_remove_disk, | ||
2400 | .spare_active = raid6_spare_active, | ||
2401 | .sync_request = sync_request, | ||
2402 | .resize = raid6_resize, | ||
2403 | .quiesce = raid6_quiesce, | ||
2404 | }; | ||
2405 | |||
2406 | static int __init raid6_init(void) | ||
2407 | { | ||
2408 | int e; | ||
2409 | |||
2410 | e = raid6_select_algo(); | ||
2411 | if ( e ) | ||
2412 | return e; | ||
2413 | |||
2414 | return register_md_personality(&raid6_personality); | ||
2415 | } | ||
2416 | |||
2417 | static void raid6_exit (void) | ||
2418 | { | ||
2419 | unregister_md_personality(&raid6_personality); | ||
2420 | } | ||
2421 | |||
2422 | module_init(raid6_init); | ||
2423 | module_exit(raid6_exit); | ||
2424 | MODULE_LICENSE("GPL"); | ||
2425 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ | ||
2426 | MODULE_ALIAS("md-raid6"); | ||
2427 | MODULE_ALIAS("md-level-6"); | ||