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1da177e4 LT |
1 | /* |
2 | * raid5.c : Multiple Devices driver for Linux | |
3 | * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman | |
4 | * Copyright (C) 1999, 2000 Ingo Molnar | |
5 | * | |
6 | * RAID-5 management functions. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * (for example /usr/src/linux/COPYING); if not, write to the Free | |
15 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
16 | */ | |
17 | ||
18 | ||
19 | #include <linux/config.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/raid/raid5.h> | |
23 | #include <linux/highmem.h> | |
24 | #include <linux/bitops.h> | |
f6705578 | 25 | #include <linux/kthread.h> |
1da177e4 LT |
26 | #include <asm/atomic.h> |
27 | ||
72626685 N |
28 | #include <linux/raid/bitmap.h> |
29 | ||
1da177e4 LT |
30 | /* |
31 | * Stripe cache | |
32 | */ | |
33 | ||
34 | #define NR_STRIPES 256 | |
35 | #define STRIPE_SIZE PAGE_SIZE | |
36 | #define STRIPE_SHIFT (PAGE_SHIFT - 9) | |
37 | #define STRIPE_SECTORS (STRIPE_SIZE>>9) | |
38 | #define IO_THRESHOLD 1 | |
fccddba0 | 39 | #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) |
1da177e4 LT |
40 | #define HASH_MASK (NR_HASH - 1) |
41 | ||
fccddba0 | 42 | #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) |
1da177e4 LT |
43 | |
44 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector | |
45 | * order without overlap. There may be several bio's per stripe+device, and | |
46 | * a bio could span several devices. | |
47 | * When walking this list for a particular stripe+device, we must never proceed | |
48 | * beyond a bio that extends past this device, as the next bio might no longer | |
49 | * be valid. | |
50 | * This macro is used to determine the 'next' bio in the list, given the sector | |
51 | * of the current stripe+device | |
52 | */ | |
53 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) | |
54 | /* | |
55 | * The following can be used to debug the driver | |
56 | */ | |
57 | #define RAID5_DEBUG 0 | |
58 | #define RAID5_PARANOIA 1 | |
59 | #if RAID5_PARANOIA && defined(CONFIG_SMP) | |
60 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) | |
61 | #else | |
62 | # define CHECK_DEVLOCK() | |
63 | #endif | |
64 | ||
65 | #define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x))) | |
66 | #if RAID5_DEBUG | |
67 | #define inline | |
68 | #define __inline__ | |
69 | #endif | |
70 | ||
71 | static void print_raid5_conf (raid5_conf_t *conf); | |
72 | ||
858119e1 | 73 | static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) |
1da177e4 LT |
74 | { |
75 | if (atomic_dec_and_test(&sh->count)) { | |
76 | if (!list_empty(&sh->lru)) | |
77 | BUG(); | |
78 | if (atomic_read(&conf->active_stripes)==0) | |
79 | BUG(); | |
80 | if (test_bit(STRIPE_HANDLE, &sh->state)) { | |
81 | if (test_bit(STRIPE_DELAYED, &sh->state)) | |
82 | list_add_tail(&sh->lru, &conf->delayed_list); | |
72626685 N |
83 | else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
84 | conf->seq_write == sh->bm_seq) | |
85 | list_add_tail(&sh->lru, &conf->bitmap_list); | |
86 | else { | |
87 | clear_bit(STRIPE_BIT_DELAY, &sh->state); | |
1da177e4 | 88 | list_add_tail(&sh->lru, &conf->handle_list); |
72626685 | 89 | } |
1da177e4 LT |
90 | md_wakeup_thread(conf->mddev->thread); |
91 | } else { | |
92 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
93 | atomic_dec(&conf->preread_active_stripes); | |
94 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
95 | md_wakeup_thread(conf->mddev->thread); | |
96 | } | |
1da177e4 | 97 | atomic_dec(&conf->active_stripes); |
ccfcc3c1 N |
98 | if (!test_bit(STRIPE_EXPANDING, &sh->state)) { |
99 | list_add_tail(&sh->lru, &conf->inactive_list); | |
1da177e4 | 100 | wake_up(&conf->wait_for_stripe); |
ccfcc3c1 | 101 | } |
1da177e4 LT |
102 | } |
103 | } | |
104 | } | |
105 | static void release_stripe(struct stripe_head *sh) | |
106 | { | |
107 | raid5_conf_t *conf = sh->raid_conf; | |
108 | unsigned long flags; | |
109 | ||
110 | spin_lock_irqsave(&conf->device_lock, flags); | |
111 | __release_stripe(conf, sh); | |
112 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
113 | } | |
114 | ||
fccddba0 | 115 | static inline void remove_hash(struct stripe_head *sh) |
1da177e4 LT |
116 | { |
117 | PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
118 | ||
fccddba0 | 119 | hlist_del_init(&sh->hash); |
1da177e4 LT |
120 | } |
121 | ||
858119e1 | 122 | static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) |
1da177e4 | 123 | { |
fccddba0 | 124 | struct hlist_head *hp = stripe_hash(conf, sh->sector); |
1da177e4 LT |
125 | |
126 | PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
127 | ||
128 | CHECK_DEVLOCK(); | |
fccddba0 | 129 | hlist_add_head(&sh->hash, hp); |
1da177e4 LT |
130 | } |
131 | ||
132 | ||
133 | /* find an idle stripe, make sure it is unhashed, and return it. */ | |
134 | static struct stripe_head *get_free_stripe(raid5_conf_t *conf) | |
135 | { | |
136 | struct stripe_head *sh = NULL; | |
137 | struct list_head *first; | |
138 | ||
139 | CHECK_DEVLOCK(); | |
140 | if (list_empty(&conf->inactive_list)) | |
141 | goto out; | |
142 | first = conf->inactive_list.next; | |
143 | sh = list_entry(first, struct stripe_head, lru); | |
144 | list_del_init(first); | |
145 | remove_hash(sh); | |
146 | atomic_inc(&conf->active_stripes); | |
147 | out: | |
148 | return sh; | |
149 | } | |
150 | ||
151 | static void shrink_buffers(struct stripe_head *sh, int num) | |
152 | { | |
153 | struct page *p; | |
154 | int i; | |
155 | ||
156 | for (i=0; i<num ; i++) { | |
157 | p = sh->dev[i].page; | |
158 | if (!p) | |
159 | continue; | |
160 | sh->dev[i].page = NULL; | |
2d1f3b5d | 161 | put_page(p); |
1da177e4 LT |
162 | } |
163 | } | |
164 | ||
165 | static int grow_buffers(struct stripe_head *sh, int num) | |
166 | { | |
167 | int i; | |
168 | ||
169 | for (i=0; i<num; i++) { | |
170 | struct page *page; | |
171 | ||
172 | if (!(page = alloc_page(GFP_KERNEL))) { | |
173 | return 1; | |
174 | } | |
175 | sh->dev[i].page = page; | |
176 | } | |
177 | return 0; | |
178 | } | |
179 | ||
180 | static void raid5_build_block (struct stripe_head *sh, int i); | |
181 | ||
7ecaa1e6 | 182 | static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) |
1da177e4 LT |
183 | { |
184 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 185 | int i; |
1da177e4 LT |
186 | |
187 | if (atomic_read(&sh->count) != 0) | |
188 | BUG(); | |
189 | if (test_bit(STRIPE_HANDLE, &sh->state)) | |
190 | BUG(); | |
191 | ||
192 | CHECK_DEVLOCK(); | |
193 | PRINTK("init_stripe called, stripe %llu\n", | |
194 | (unsigned long long)sh->sector); | |
195 | ||
196 | remove_hash(sh); | |
197 | ||
198 | sh->sector = sector; | |
199 | sh->pd_idx = pd_idx; | |
200 | sh->state = 0; | |
201 | ||
7ecaa1e6 N |
202 | sh->disks = disks; |
203 | ||
204 | for (i = sh->disks; i--; ) { | |
1da177e4 LT |
205 | struct r5dev *dev = &sh->dev[i]; |
206 | ||
207 | if (dev->toread || dev->towrite || dev->written || | |
208 | test_bit(R5_LOCKED, &dev->flags)) { | |
209 | printk("sector=%llx i=%d %p %p %p %d\n", | |
210 | (unsigned long long)sh->sector, i, dev->toread, | |
211 | dev->towrite, dev->written, | |
212 | test_bit(R5_LOCKED, &dev->flags)); | |
213 | BUG(); | |
214 | } | |
215 | dev->flags = 0; | |
216 | raid5_build_block(sh, i); | |
217 | } | |
218 | insert_hash(conf, sh); | |
219 | } | |
220 | ||
7ecaa1e6 | 221 | static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks) |
1da177e4 LT |
222 | { |
223 | struct stripe_head *sh; | |
fccddba0 | 224 | struct hlist_node *hn; |
1da177e4 LT |
225 | |
226 | CHECK_DEVLOCK(); | |
227 | PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); | |
fccddba0 | 228 | hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) |
7ecaa1e6 | 229 | if (sh->sector == sector && sh->disks == disks) |
1da177e4 LT |
230 | return sh; |
231 | PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); | |
232 | return NULL; | |
233 | } | |
234 | ||
235 | static void unplug_slaves(mddev_t *mddev); | |
236 | static void raid5_unplug_device(request_queue_t *q); | |
237 | ||
7ecaa1e6 N |
238 | static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks, |
239 | int pd_idx, int noblock) | |
1da177e4 LT |
240 | { |
241 | struct stripe_head *sh; | |
242 | ||
243 | PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); | |
244 | ||
245 | spin_lock_irq(&conf->device_lock); | |
246 | ||
247 | do { | |
72626685 N |
248 | wait_event_lock_irq(conf->wait_for_stripe, |
249 | conf->quiesce == 0, | |
250 | conf->device_lock, /* nothing */); | |
7ecaa1e6 | 251 | sh = __find_stripe(conf, sector, disks); |
1da177e4 LT |
252 | if (!sh) { |
253 | if (!conf->inactive_blocked) | |
254 | sh = get_free_stripe(conf); | |
255 | if (noblock && sh == NULL) | |
256 | break; | |
257 | if (!sh) { | |
258 | conf->inactive_blocked = 1; | |
259 | wait_event_lock_irq(conf->wait_for_stripe, | |
260 | !list_empty(&conf->inactive_list) && | |
5036805b N |
261 | (atomic_read(&conf->active_stripes) |
262 | < (conf->max_nr_stripes *3/4) | |
1da177e4 LT |
263 | || !conf->inactive_blocked), |
264 | conf->device_lock, | |
b3b46be3 | 265 | unplug_slaves(conf->mddev) |
1da177e4 LT |
266 | ); |
267 | conf->inactive_blocked = 0; | |
268 | } else | |
7ecaa1e6 | 269 | init_stripe(sh, sector, pd_idx, disks); |
1da177e4 LT |
270 | } else { |
271 | if (atomic_read(&sh->count)) { | |
272 | if (!list_empty(&sh->lru)) | |
273 | BUG(); | |
274 | } else { | |
275 | if (!test_bit(STRIPE_HANDLE, &sh->state)) | |
276 | atomic_inc(&conf->active_stripes); | |
ccfcc3c1 N |
277 | if (!list_empty(&sh->lru)) |
278 | list_del_init(&sh->lru); | |
1da177e4 LT |
279 | } |
280 | } | |
281 | } while (sh == NULL); | |
282 | ||
283 | if (sh) | |
284 | atomic_inc(&sh->count); | |
285 | ||
286 | spin_unlock_irq(&conf->device_lock); | |
287 | return sh; | |
288 | } | |
289 | ||
3f294f4f | 290 | static int grow_one_stripe(raid5_conf_t *conf) |
1da177e4 LT |
291 | { |
292 | struct stripe_head *sh; | |
3f294f4f N |
293 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); |
294 | if (!sh) | |
295 | return 0; | |
296 | memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); | |
297 | sh->raid_conf = conf; | |
298 | spin_lock_init(&sh->lock); | |
299 | ||
300 | if (grow_buffers(sh, conf->raid_disks)) { | |
301 | shrink_buffers(sh, conf->raid_disks); | |
302 | kmem_cache_free(conf->slab_cache, sh); | |
303 | return 0; | |
304 | } | |
7ecaa1e6 | 305 | sh->disks = conf->raid_disks; |
3f294f4f N |
306 | /* we just created an active stripe so... */ |
307 | atomic_set(&sh->count, 1); | |
308 | atomic_inc(&conf->active_stripes); | |
309 | INIT_LIST_HEAD(&sh->lru); | |
310 | release_stripe(sh); | |
311 | return 1; | |
312 | } | |
313 | ||
314 | static int grow_stripes(raid5_conf_t *conf, int num) | |
315 | { | |
1da177e4 LT |
316 | kmem_cache_t *sc; |
317 | int devs = conf->raid_disks; | |
318 | ||
ad01c9e3 N |
319 | sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev)); |
320 | sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev)); | |
321 | conf->active_name = 0; | |
322 | sc = kmem_cache_create(conf->cache_name[conf->active_name], | |
1da177e4 LT |
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; | |
ad01c9e3 | 328 | conf->pool_size = devs; |
1da177e4 | 329 | while (num--) { |
3f294f4f | 330 | if (!grow_one_stripe(conf)) |
1da177e4 | 331 | return 1; |
1da177e4 LT |
332 | } |
333 | return 0; | |
334 | } | |
29269553 N |
335 | |
336 | #ifdef CONFIG_MD_RAID5_RESHAPE | |
ad01c9e3 N |
337 | static int resize_stripes(raid5_conf_t *conf, int newsize) |
338 | { | |
339 | /* Make all the stripes able to hold 'newsize' devices. | |
340 | * New slots in each stripe get 'page' set to a new page. | |
341 | * | |
342 | * This happens in stages: | |
343 | * 1/ create a new kmem_cache and allocate the required number of | |
344 | * stripe_heads. | |
345 | * 2/ gather all the old stripe_heads and tranfer the pages across | |
346 | * to the new stripe_heads. This will have the side effect of | |
347 | * freezing the array as once all stripe_heads have been collected, | |
348 | * no IO will be possible. Old stripe heads are freed once their | |
349 | * pages have been transferred over, and the old kmem_cache is | |
350 | * freed when all stripes are done. | |
351 | * 3/ reallocate conf->disks to be suitable bigger. If this fails, | |
352 | * we simple return a failre status - no need to clean anything up. | |
353 | * 4/ allocate new pages for the new slots in the new stripe_heads. | |
354 | * If this fails, we don't bother trying the shrink the | |
355 | * stripe_heads down again, we just leave them as they are. | |
356 | * As each stripe_head is processed the new one is released into | |
357 | * active service. | |
358 | * | |
359 | * Once step2 is started, we cannot afford to wait for a write, | |
360 | * so we use GFP_NOIO allocations. | |
361 | */ | |
362 | struct stripe_head *osh, *nsh; | |
363 | LIST_HEAD(newstripes); | |
364 | struct disk_info *ndisks; | |
365 | int err = 0; | |
366 | kmem_cache_t *sc; | |
367 | int i; | |
368 | ||
369 | if (newsize <= conf->pool_size) | |
370 | return 0; /* never bother to shrink */ | |
371 | ||
372 | /* Step 1 */ | |
373 | sc = kmem_cache_create(conf->cache_name[1-conf->active_name], | |
374 | sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), | |
375 | 0, 0, NULL, NULL); | |
376 | if (!sc) | |
377 | return -ENOMEM; | |
378 | ||
379 | for (i = conf->max_nr_stripes; i; i--) { | |
380 | nsh = kmem_cache_alloc(sc, GFP_KERNEL); | |
381 | if (!nsh) | |
382 | break; | |
383 | ||
384 | memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); | |
385 | ||
386 | nsh->raid_conf = conf; | |
387 | spin_lock_init(&nsh->lock); | |
388 | ||
389 | list_add(&nsh->lru, &newstripes); | |
390 | } | |
391 | if (i) { | |
392 | /* didn't get enough, give up */ | |
393 | while (!list_empty(&newstripes)) { | |
394 | nsh = list_entry(newstripes.next, struct stripe_head, lru); | |
395 | list_del(&nsh->lru); | |
396 | kmem_cache_free(sc, nsh); | |
397 | } | |
398 | kmem_cache_destroy(sc); | |
399 | return -ENOMEM; | |
400 | } | |
401 | /* Step 2 - Must use GFP_NOIO now. | |
402 | * OK, we have enough stripes, start collecting inactive | |
403 | * stripes and copying them over | |
404 | */ | |
405 | list_for_each_entry(nsh, &newstripes, lru) { | |
406 | spin_lock_irq(&conf->device_lock); | |
407 | wait_event_lock_irq(conf->wait_for_stripe, | |
408 | !list_empty(&conf->inactive_list), | |
409 | conf->device_lock, | |
b3b46be3 | 410 | unplug_slaves(conf->mddev) |
ad01c9e3 N |
411 | ); |
412 | osh = get_free_stripe(conf); | |
413 | spin_unlock_irq(&conf->device_lock); | |
414 | atomic_set(&nsh->count, 1); | |
415 | for(i=0; i<conf->pool_size; i++) | |
416 | nsh->dev[i].page = osh->dev[i].page; | |
417 | for( ; i<newsize; i++) | |
418 | nsh->dev[i].page = NULL; | |
419 | kmem_cache_free(conf->slab_cache, osh); | |
420 | } | |
421 | kmem_cache_destroy(conf->slab_cache); | |
422 | ||
423 | /* Step 3. | |
424 | * At this point, we are holding all the stripes so the array | |
425 | * is completely stalled, so now is a good time to resize | |
426 | * conf->disks. | |
427 | */ | |
428 | ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); | |
429 | if (ndisks) { | |
430 | for (i=0; i<conf->raid_disks; i++) | |
431 | ndisks[i] = conf->disks[i]; | |
432 | kfree(conf->disks); | |
433 | conf->disks = ndisks; | |
434 | } else | |
435 | err = -ENOMEM; | |
436 | ||
437 | /* Step 4, return new stripes to service */ | |
438 | while(!list_empty(&newstripes)) { | |
439 | nsh = list_entry(newstripes.next, struct stripe_head, lru); | |
440 | list_del_init(&nsh->lru); | |
441 | for (i=conf->raid_disks; i < newsize; i++) | |
442 | if (nsh->dev[i].page == NULL) { | |
443 | struct page *p = alloc_page(GFP_NOIO); | |
444 | nsh->dev[i].page = p; | |
445 | if (!p) | |
446 | err = -ENOMEM; | |
447 | } | |
448 | release_stripe(nsh); | |
449 | } | |
450 | /* critical section pass, GFP_NOIO no longer needed */ | |
451 | ||
452 | conf->slab_cache = sc; | |
453 | conf->active_name = 1-conf->active_name; | |
454 | conf->pool_size = newsize; | |
455 | return err; | |
456 | } | |
29269553 | 457 | #endif |
1da177e4 | 458 | |
3f294f4f | 459 | static int drop_one_stripe(raid5_conf_t *conf) |
1da177e4 LT |
460 | { |
461 | struct stripe_head *sh; | |
462 | ||
3f294f4f N |
463 | spin_lock_irq(&conf->device_lock); |
464 | sh = get_free_stripe(conf); | |
465 | spin_unlock_irq(&conf->device_lock); | |
466 | if (!sh) | |
467 | return 0; | |
468 | if (atomic_read(&sh->count)) | |
469 | BUG(); | |
ad01c9e3 | 470 | shrink_buffers(sh, conf->pool_size); |
3f294f4f N |
471 | kmem_cache_free(conf->slab_cache, sh); |
472 | atomic_dec(&conf->active_stripes); | |
473 | return 1; | |
474 | } | |
475 | ||
476 | static void shrink_stripes(raid5_conf_t *conf) | |
477 | { | |
478 | while (drop_one_stripe(conf)) | |
479 | ; | |
480 | ||
29fc7e3e N |
481 | if (conf->slab_cache) |
482 | kmem_cache_destroy(conf->slab_cache); | |
1da177e4 LT |
483 | conf->slab_cache = NULL; |
484 | } | |
485 | ||
4e5314b5 | 486 | static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, |
1da177e4 LT |
487 | int error) |
488 | { | |
489 | struct stripe_head *sh = bi->bi_private; | |
490 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 491 | int disks = sh->disks, i; |
1da177e4 LT |
492 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
493 | ||
494 | if (bi->bi_size) | |
495 | return 1; | |
496 | ||
497 | for (i=0 ; i<disks; i++) | |
498 | if (bi == &sh->dev[i].req) | |
499 | break; | |
500 | ||
501 | PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", | |
502 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
503 | uptodate); | |
504 | if (i == disks) { | |
505 | BUG(); | |
506 | return 0; | |
507 | } | |
508 | ||
509 | if (uptodate) { | |
510 | #if 0 | |
511 | struct bio *bio; | |
512 | unsigned long flags; | |
513 | spin_lock_irqsave(&conf->device_lock, flags); | |
514 | /* we can return a buffer if we bypassed the cache or | |
515 | * if the top buffer is not in highmem. If there are | |
516 | * multiple buffers, leave the extra work to | |
517 | * handle_stripe | |
518 | */ | |
519 | buffer = sh->bh_read[i]; | |
520 | if (buffer && | |
521 | (!PageHighMem(buffer->b_page) | |
522 | || buffer->b_page == bh->b_page ) | |
523 | ) { | |
524 | sh->bh_read[i] = buffer->b_reqnext; | |
525 | buffer->b_reqnext = NULL; | |
526 | } else | |
527 | buffer = NULL; | |
528 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
529 | if (sh->bh_page[i]==bh->b_page) | |
530 | set_buffer_uptodate(bh); | |
531 | if (buffer) { | |
532 | if (buffer->b_page != bh->b_page) | |
533 | memcpy(buffer->b_data, bh->b_data, bh->b_size); | |
534 | buffer->b_end_io(buffer, 1); | |
535 | } | |
536 | #else | |
537 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
4e5314b5 N |
538 | #endif |
539 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
14f8d26b | 540 | printk(KERN_INFO "raid5: read error corrected!!\n"); |
4e5314b5 N |
541 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
542 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
543 | } | |
ba22dcbf N |
544 | if (atomic_read(&conf->disks[i].rdev->read_errors)) |
545 | atomic_set(&conf->disks[i].rdev->read_errors, 0); | |
1da177e4 | 546 | } else { |
ba22dcbf | 547 | int retry = 0; |
1da177e4 | 548 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
ba22dcbf N |
549 | atomic_inc(&conf->disks[i].rdev->read_errors); |
550 | if (conf->mddev->degraded) | |
14f8d26b | 551 | printk(KERN_WARNING "raid5: read error not correctable.\n"); |
ba22dcbf | 552 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) |
4e5314b5 | 553 | /* Oh, no!!! */ |
14f8d26b | 554 | printk(KERN_WARNING "raid5: read error NOT corrected!!\n"); |
ba22dcbf N |
555 | else if (atomic_read(&conf->disks[i].rdev->read_errors) |
556 | > conf->max_nr_stripes) | |
14f8d26b N |
557 | printk(KERN_WARNING |
558 | "raid5: Too many read errors, failing device.\n"); | |
ba22dcbf N |
559 | else |
560 | retry = 1; | |
561 | if (retry) | |
562 | set_bit(R5_ReadError, &sh->dev[i].flags); | |
563 | else { | |
4e5314b5 N |
564 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
565 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
566 | md_error(conf->mddev, conf->disks[i].rdev); | |
ba22dcbf | 567 | } |
1da177e4 LT |
568 | } |
569 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
570 | #if 0 | |
571 | /* must restore b_page before unlocking buffer... */ | |
572 | if (sh->bh_page[i] != bh->b_page) { | |
573 | bh->b_page = sh->bh_page[i]; | |
574 | bh->b_data = page_address(bh->b_page); | |
575 | clear_buffer_uptodate(bh); | |
576 | } | |
577 | #endif | |
578 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
579 | set_bit(STRIPE_HANDLE, &sh->state); | |
580 | release_stripe(sh); | |
581 | return 0; | |
582 | } | |
583 | ||
584 | static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, | |
585 | int error) | |
586 | { | |
587 | struct stripe_head *sh = bi->bi_private; | |
588 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 589 | int disks = sh->disks, i; |
1da177e4 LT |
590 | unsigned long flags; |
591 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
592 | ||
593 | if (bi->bi_size) | |
594 | return 1; | |
595 | ||
596 | for (i=0 ; i<disks; i++) | |
597 | if (bi == &sh->dev[i].req) | |
598 | break; | |
599 | ||
600 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", | |
601 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
602 | uptodate); | |
603 | if (i == disks) { | |
604 | BUG(); | |
605 | return 0; | |
606 | } | |
607 | ||
608 | spin_lock_irqsave(&conf->device_lock, flags); | |
609 | if (!uptodate) | |
610 | md_error(conf->mddev, conf->disks[i].rdev); | |
611 | ||
612 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
613 | ||
614 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
615 | set_bit(STRIPE_HANDLE, &sh->state); | |
616 | __release_stripe(conf, sh); | |
617 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
618 | return 0; | |
619 | } | |
620 | ||
621 | ||
622 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | |
623 | ||
624 | static void raid5_build_block (struct stripe_head *sh, int i) | |
625 | { | |
626 | struct r5dev *dev = &sh->dev[i]; | |
627 | ||
628 | bio_init(&dev->req); | |
629 | dev->req.bi_io_vec = &dev->vec; | |
630 | dev->req.bi_vcnt++; | |
631 | dev->req.bi_max_vecs++; | |
632 | dev->vec.bv_page = dev->page; | |
633 | dev->vec.bv_len = STRIPE_SIZE; | |
634 | dev->vec.bv_offset = 0; | |
635 | ||
636 | dev->req.bi_sector = sh->sector; | |
637 | dev->req.bi_private = sh; | |
638 | ||
639 | dev->flags = 0; | |
640 | if (i != sh->pd_idx) | |
641 | dev->sector = compute_blocknr(sh, i); | |
642 | } | |
643 | ||
644 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
645 | { | |
646 | char b[BDEVNAME_SIZE]; | |
647 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
648 | PRINTK("raid5: error called\n"); | |
649 | ||
b2d444d7 | 650 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 651 | mddev->sb_dirty = 1; |
b2d444d7 | 652 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
653 | conf->working_disks--; |
654 | mddev->degraded++; | |
655 | conf->failed_disks++; | |
b2d444d7 | 656 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
657 | /* |
658 | * if recovery was running, make sure it aborts. | |
659 | */ | |
660 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
661 | } | |
b2d444d7 | 662 | set_bit(Faulty, &rdev->flags); |
1da177e4 LT |
663 | printk (KERN_ALERT |
664 | "raid5: Disk failure on %s, disabling device." | |
665 | " Operation continuing on %d devices\n", | |
666 | bdevname(rdev->bdev,b), conf->working_disks); | |
667 | } | |
668 | } | |
669 | ||
670 | /* | |
671 | * Input: a 'big' sector number, | |
672 | * Output: index of the data and parity disk, and the sector # in them. | |
673 | */ | |
674 | static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, | |
675 | unsigned int data_disks, unsigned int * dd_idx, | |
676 | unsigned int * pd_idx, raid5_conf_t *conf) | |
677 | { | |
678 | long stripe; | |
679 | unsigned long chunk_number; | |
680 | unsigned int chunk_offset; | |
681 | sector_t new_sector; | |
682 | int sectors_per_chunk = conf->chunk_size >> 9; | |
683 | ||
684 | /* First compute the information on this sector */ | |
685 | ||
686 | /* | |
687 | * Compute the chunk number and the sector offset inside the chunk | |
688 | */ | |
689 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | |
690 | chunk_number = r_sector; | |
691 | BUG_ON(r_sector != chunk_number); | |
692 | ||
693 | /* | |
694 | * Compute the stripe number | |
695 | */ | |
696 | stripe = chunk_number / data_disks; | |
697 | ||
698 | /* | |
699 | * Compute the data disk and parity disk indexes inside the stripe | |
700 | */ | |
701 | *dd_idx = chunk_number % data_disks; | |
702 | ||
703 | /* | |
704 | * Select the parity disk based on the user selected algorithm. | |
705 | */ | |
706 | if (conf->level == 4) | |
707 | *pd_idx = data_disks; | |
708 | else switch (conf->algorithm) { | |
709 | case ALGORITHM_LEFT_ASYMMETRIC: | |
710 | *pd_idx = data_disks - stripe % raid_disks; | |
711 | if (*dd_idx >= *pd_idx) | |
712 | (*dd_idx)++; | |
713 | break; | |
714 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
715 | *pd_idx = stripe % raid_disks; | |
716 | if (*dd_idx >= *pd_idx) | |
717 | (*dd_idx)++; | |
718 | break; | |
719 | case ALGORITHM_LEFT_SYMMETRIC: | |
720 | *pd_idx = data_disks - stripe % raid_disks; | |
721 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
722 | break; | |
723 | case ALGORITHM_RIGHT_SYMMETRIC: | |
724 | *pd_idx = stripe % raid_disks; | |
725 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
726 | break; | |
727 | default: | |
14f8d26b | 728 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1da177e4 LT |
729 | conf->algorithm); |
730 | } | |
731 | ||
732 | /* | |
733 | * Finally, compute the new sector number | |
734 | */ | |
735 | new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; | |
736 | return new_sector; | |
737 | } | |
738 | ||
739 | ||
740 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | |
741 | { | |
742 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 743 | int raid_disks = sh->disks, data_disks = raid_disks - 1; |
1da177e4 LT |
744 | sector_t new_sector = sh->sector, check; |
745 | int sectors_per_chunk = conf->chunk_size >> 9; | |
746 | sector_t stripe; | |
747 | int chunk_offset; | |
748 | int chunk_number, dummy1, dummy2, dd_idx = i; | |
749 | sector_t r_sector; | |
750 | ||
751 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | |
752 | stripe = new_sector; | |
753 | BUG_ON(new_sector != stripe); | |
754 | ||
755 | ||
756 | switch (conf->algorithm) { | |
757 | case ALGORITHM_LEFT_ASYMMETRIC: | |
758 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
759 | if (i > sh->pd_idx) | |
760 | i--; | |
761 | break; | |
762 | case ALGORITHM_LEFT_SYMMETRIC: | |
763 | case ALGORITHM_RIGHT_SYMMETRIC: | |
764 | if (i < sh->pd_idx) | |
765 | i += raid_disks; | |
766 | i -= (sh->pd_idx + 1); | |
767 | break; | |
768 | default: | |
14f8d26b | 769 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1da177e4 LT |
770 | conf->algorithm); |
771 | } | |
772 | ||
773 | chunk_number = stripe * data_disks + i; | |
774 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | |
775 | ||
776 | check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | |
777 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | |
14f8d26b | 778 | printk(KERN_ERR "compute_blocknr: map not correct\n"); |
1da177e4 LT |
779 | return 0; |
780 | } | |
781 | return r_sector; | |
782 | } | |
783 | ||
784 | ||
785 | ||
786 | /* | |
787 | * Copy data between a page in the stripe cache, and a bio. | |
788 | * There are no alignment or size guarantees between the page or the | |
789 | * bio except that there is some overlap. | |
790 | * All iovecs in the bio must be considered. | |
791 | */ | |
792 | static void copy_data(int frombio, struct bio *bio, | |
793 | struct page *page, | |
794 | sector_t sector) | |
795 | { | |
796 | char *pa = page_address(page); | |
797 | struct bio_vec *bvl; | |
798 | int i; | |
799 | int page_offset; | |
800 | ||
801 | if (bio->bi_sector >= sector) | |
802 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
803 | else | |
804 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
805 | bio_for_each_segment(bvl, bio, i) { | |
806 | int len = bio_iovec_idx(bio,i)->bv_len; | |
807 | int clen; | |
808 | int b_offset = 0; | |
809 | ||
810 | if (page_offset < 0) { | |
811 | b_offset = -page_offset; | |
812 | page_offset += b_offset; | |
813 | len -= b_offset; | |
814 | } | |
815 | ||
816 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
817 | clen = STRIPE_SIZE - page_offset; | |
818 | else clen = len; | |
819 | ||
820 | if (clen > 0) { | |
821 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | |
822 | if (frombio) | |
823 | memcpy(pa+page_offset, ba+b_offset, clen); | |
824 | else | |
825 | memcpy(ba+b_offset, pa+page_offset, clen); | |
826 | __bio_kunmap_atomic(ba, KM_USER0); | |
827 | } | |
828 | if (clen < len) /* hit end of page */ | |
829 | break; | |
830 | page_offset += len; | |
831 | } | |
832 | } | |
833 | ||
834 | #define check_xor() do { \ | |
835 | if (count == MAX_XOR_BLOCKS) { \ | |
836 | xor_block(count, STRIPE_SIZE, ptr); \ | |
837 | count = 1; \ | |
838 | } \ | |
839 | } while(0) | |
840 | ||
841 | ||
842 | static void compute_block(struct stripe_head *sh, int dd_idx) | |
843 | { | |
7ecaa1e6 | 844 | int i, count, disks = sh->disks; |
1da177e4 LT |
845 | void *ptr[MAX_XOR_BLOCKS], *p; |
846 | ||
847 | PRINTK("compute_block, stripe %llu, idx %d\n", | |
848 | (unsigned long long)sh->sector, dd_idx); | |
849 | ||
850 | ptr[0] = page_address(sh->dev[dd_idx].page); | |
851 | memset(ptr[0], 0, STRIPE_SIZE); | |
852 | count = 1; | |
853 | for (i = disks ; i--; ) { | |
854 | if (i == dd_idx) | |
855 | continue; | |
856 | p = page_address(sh->dev[i].page); | |
857 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
858 | ptr[count++] = p; | |
859 | else | |
14f8d26b | 860 | printk(KERN_ERR "compute_block() %d, stripe %llu, %d" |
1da177e4 LT |
861 | " not present\n", dd_idx, |
862 | (unsigned long long)sh->sector, i); | |
863 | ||
864 | check_xor(); | |
865 | } | |
866 | if (count != 1) | |
867 | xor_block(count, STRIPE_SIZE, ptr); | |
868 | set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
869 | } | |
870 | ||
871 | static void compute_parity(struct stripe_head *sh, int method) | |
872 | { | |
873 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 874 | int i, pd_idx = sh->pd_idx, disks = sh->disks, count; |
1da177e4 LT |
875 | void *ptr[MAX_XOR_BLOCKS]; |
876 | struct bio *chosen; | |
877 | ||
878 | PRINTK("compute_parity, stripe %llu, method %d\n", | |
879 | (unsigned long long)sh->sector, method); | |
880 | ||
881 | count = 1; | |
882 | ptr[0] = page_address(sh->dev[pd_idx].page); | |
883 | switch(method) { | |
884 | case READ_MODIFY_WRITE: | |
885 | if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags)) | |
886 | BUG(); | |
887 | for (i=disks ; i-- ;) { | |
888 | if (i==pd_idx) | |
889 | continue; | |
890 | if (sh->dev[i].towrite && | |
891 | test_bit(R5_UPTODATE, &sh->dev[i].flags)) { | |
892 | ptr[count++] = page_address(sh->dev[i].page); | |
893 | chosen = sh->dev[i].towrite; | |
894 | sh->dev[i].towrite = NULL; | |
895 | ||
896 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
897 | wake_up(&conf->wait_for_overlap); | |
898 | ||
899 | if (sh->dev[i].written) BUG(); | |
900 | sh->dev[i].written = chosen; | |
901 | check_xor(); | |
902 | } | |
903 | } | |
904 | break; | |
905 | case RECONSTRUCT_WRITE: | |
906 | memset(ptr[0], 0, STRIPE_SIZE); | |
907 | for (i= disks; i-- ;) | |
908 | if (i!=pd_idx && sh->dev[i].towrite) { | |
909 | chosen = sh->dev[i].towrite; | |
910 | sh->dev[i].towrite = NULL; | |
911 | ||
912 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
913 | wake_up(&conf->wait_for_overlap); | |
914 | ||
915 | if (sh->dev[i].written) BUG(); | |
916 | sh->dev[i].written = chosen; | |
917 | } | |
918 | break; | |
919 | case CHECK_PARITY: | |
920 | break; | |
921 | } | |
922 | if (count>1) { | |
923 | xor_block(count, STRIPE_SIZE, ptr); | |
924 | count = 1; | |
925 | } | |
926 | ||
927 | for (i = disks; i--;) | |
928 | if (sh->dev[i].written) { | |
929 | sector_t sector = sh->dev[i].sector; | |
930 | struct bio *wbi = sh->dev[i].written; | |
931 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | |
932 | copy_data(1, wbi, sh->dev[i].page, sector); | |
933 | wbi = r5_next_bio(wbi, sector); | |
934 | } | |
935 | ||
936 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
937 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
938 | } | |
939 | ||
940 | switch(method) { | |
941 | case RECONSTRUCT_WRITE: | |
942 | case CHECK_PARITY: | |
943 | for (i=disks; i--;) | |
944 | if (i != pd_idx) { | |
945 | ptr[count++] = page_address(sh->dev[i].page); | |
946 | check_xor(); | |
947 | } | |
948 | break; | |
949 | case READ_MODIFY_WRITE: | |
950 | for (i = disks; i--;) | |
951 | if (sh->dev[i].written) { | |
952 | ptr[count++] = page_address(sh->dev[i].page); | |
953 | check_xor(); | |
954 | } | |
955 | } | |
956 | if (count != 1) | |
957 | xor_block(count, STRIPE_SIZE, ptr); | |
958 | ||
959 | if (method != CHECK_PARITY) { | |
960 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
961 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
962 | } else | |
963 | clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
964 | } | |
965 | ||
966 | /* | |
967 | * Each stripe/dev can have one or more bion attached. | |
968 | * toread/towrite point to the first in a chain. | |
969 | * The bi_next chain must be in order. | |
970 | */ | |
971 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | |
972 | { | |
973 | struct bio **bip; | |
974 | raid5_conf_t *conf = sh->raid_conf; | |
72626685 | 975 | int firstwrite=0; |
1da177e4 LT |
976 | |
977 | PRINTK("adding bh b#%llu to stripe s#%llu\n", | |
978 | (unsigned long long)bi->bi_sector, | |
979 | (unsigned long long)sh->sector); | |
980 | ||
981 | ||
982 | spin_lock(&sh->lock); | |
983 | spin_lock_irq(&conf->device_lock); | |
72626685 | 984 | if (forwrite) { |
1da177e4 | 985 | bip = &sh->dev[dd_idx].towrite; |
72626685 N |
986 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
987 | firstwrite = 1; | |
988 | } else | |
1da177e4 LT |
989 | bip = &sh->dev[dd_idx].toread; |
990 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | |
991 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | |
992 | goto overlap; | |
993 | bip = & (*bip)->bi_next; | |
994 | } | |
995 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | |
996 | goto overlap; | |
997 | ||
998 | if (*bip && bi->bi_next && (*bip) != bi->bi_next) | |
999 | BUG(); | |
1000 | if (*bip) | |
1001 | bi->bi_next = *bip; | |
1002 | *bip = bi; | |
1003 | bi->bi_phys_segments ++; | |
1004 | spin_unlock_irq(&conf->device_lock); | |
1005 | spin_unlock(&sh->lock); | |
1006 | ||
1007 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", | |
1008 | (unsigned long long)bi->bi_sector, | |
1009 | (unsigned long long)sh->sector, dd_idx); | |
1010 | ||
72626685 N |
1011 | if (conf->mddev->bitmap && firstwrite) { |
1012 | sh->bm_seq = conf->seq_write; | |
1013 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | |
1014 | STRIPE_SECTORS, 0); | |
1015 | set_bit(STRIPE_BIT_DELAY, &sh->state); | |
1016 | } | |
1017 | ||
1da177e4 LT |
1018 | if (forwrite) { |
1019 | /* check if page is covered */ | |
1020 | sector_t sector = sh->dev[dd_idx].sector; | |
1021 | for (bi=sh->dev[dd_idx].towrite; | |
1022 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | |
1023 | bi && bi->bi_sector <= sector; | |
1024 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | |
1025 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | |
1026 | sector = bi->bi_sector + (bi->bi_size>>9); | |
1027 | } | |
1028 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | |
1029 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | |
1030 | } | |
1031 | return 1; | |
1032 | ||
1033 | overlap: | |
1034 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | |
1035 | spin_unlock_irq(&conf->device_lock); | |
1036 | spin_unlock(&sh->lock); | |
1037 | return 0; | |
1038 | } | |
1039 | ||
29269553 N |
1040 | static void end_reshape(raid5_conf_t *conf); |
1041 | ||
ccfcc3c1 N |
1042 | static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) |
1043 | { | |
1044 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1045 | sector_t x = stripe; | |
1046 | int pd_idx, dd_idx; | |
1047 | int chunk_offset = sector_div(x, sectors_per_chunk); | |
1048 | stripe = x; | |
1049 | raid5_compute_sector(stripe*(disks-1)*sectors_per_chunk | |
1050 | + chunk_offset, disks, disks-1, &dd_idx, &pd_idx, conf); | |
1051 | return pd_idx; | |
1052 | } | |
1053 | ||
1da177e4 LT |
1054 | |
1055 | /* | |
1056 | * handle_stripe - do things to a stripe. | |
1057 | * | |
1058 | * We lock the stripe and then examine the state of various bits | |
1059 | * to see what needs to be done. | |
1060 | * Possible results: | |
1061 | * return some read request which now have data | |
1062 | * return some write requests which are safely on disc | |
1063 | * schedule a read on some buffers | |
1064 | * schedule a write of some buffers | |
1065 | * return confirmation of parity correctness | |
1066 | * | |
1067 | * Parity calculations are done inside the stripe lock | |
1068 | * buffers are taken off read_list or write_list, and bh_cache buffers | |
1069 | * get BH_Lock set before the stripe lock is released. | |
1070 | * | |
1071 | */ | |
1072 | ||
1073 | static void handle_stripe(struct stripe_head *sh) | |
1074 | { | |
1075 | raid5_conf_t *conf = sh->raid_conf; | |
7ecaa1e6 | 1076 | int disks = sh->disks; |
1da177e4 LT |
1077 | struct bio *return_bi= NULL; |
1078 | struct bio *bi; | |
1079 | int i; | |
ccfcc3c1 | 1080 | int syncing, expanding, expanded; |
1da177e4 LT |
1081 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; |
1082 | int non_overwrite = 0; | |
1083 | int failed_num=0; | |
1084 | struct r5dev *dev; | |
1085 | ||
1086 | PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n", | |
1087 | (unsigned long long)sh->sector, atomic_read(&sh->count), | |
1088 | sh->pd_idx); | |
1089 | ||
1090 | spin_lock(&sh->lock); | |
1091 | clear_bit(STRIPE_HANDLE, &sh->state); | |
1092 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1093 | ||
1094 | syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
ccfcc3c1 N |
1095 | expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); |
1096 | expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); | |
1da177e4 LT |
1097 | /* Now to look around and see what can be done */ |
1098 | ||
9910f16a | 1099 | rcu_read_lock(); |
1da177e4 LT |
1100 | for (i=disks; i--; ) { |
1101 | mdk_rdev_t *rdev; | |
1102 | dev = &sh->dev[i]; | |
1103 | clear_bit(R5_Insync, &dev->flags); | |
1da177e4 LT |
1104 | |
1105 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", | |
1106 | i, dev->flags, dev->toread, dev->towrite, dev->written); | |
1107 | /* maybe we can reply to a read */ | |
1108 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | |
1109 | struct bio *rbi, *rbi2; | |
1110 | PRINTK("Return read for disc %d\n", i); | |
1111 | spin_lock_irq(&conf->device_lock); | |
1112 | rbi = dev->toread; | |
1113 | dev->toread = NULL; | |
1114 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
1115 | wake_up(&conf->wait_for_overlap); | |
1116 | spin_unlock_irq(&conf->device_lock); | |
1117 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1118 | copy_data(0, rbi, dev->page, dev->sector); | |
1119 | rbi2 = r5_next_bio(rbi, dev->sector); | |
1120 | spin_lock_irq(&conf->device_lock); | |
1121 | if (--rbi->bi_phys_segments == 0) { | |
1122 | rbi->bi_next = return_bi; | |
1123 | return_bi = rbi; | |
1124 | } | |
1125 | spin_unlock_irq(&conf->device_lock); | |
1126 | rbi = rbi2; | |
1127 | } | |
1128 | } | |
1129 | ||
1130 | /* now count some things */ | |
1131 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; | |
1132 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; | |
1133 | ||
1134 | ||
1135 | if (dev->toread) to_read++; | |
1136 | if (dev->towrite) { | |
1137 | to_write++; | |
1138 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
1139 | non_overwrite++; | |
1140 | } | |
1141 | if (dev->written) written++; | |
9910f16a | 1142 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1143 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
14f8d26b | 1144 | /* The ReadError flag will just be confusing now */ |
4e5314b5 N |
1145 | clear_bit(R5_ReadError, &dev->flags); |
1146 | clear_bit(R5_ReWrite, &dev->flags); | |
1147 | } | |
b2d444d7 | 1148 | if (!rdev || !test_bit(In_sync, &rdev->flags) |
4e5314b5 | 1149 | || test_bit(R5_ReadError, &dev->flags)) { |
1da177e4 LT |
1150 | failed++; |
1151 | failed_num = i; | |
1152 | } else | |
1153 | set_bit(R5_Insync, &dev->flags); | |
1154 | } | |
9910f16a | 1155 | rcu_read_unlock(); |
1da177e4 LT |
1156 | PRINTK("locked=%d uptodate=%d to_read=%d" |
1157 | " to_write=%d failed=%d failed_num=%d\n", | |
1158 | locked, uptodate, to_read, to_write, failed, failed_num); | |
1159 | /* check if the array has lost two devices and, if so, some requests might | |
1160 | * need to be failed | |
1161 | */ | |
1162 | if (failed > 1 && to_read+to_write+written) { | |
1da177e4 | 1163 | for (i=disks; i--; ) { |
72626685 | 1164 | int bitmap_end = 0; |
4e5314b5 N |
1165 | |
1166 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
9910f16a N |
1167 | mdk_rdev_t *rdev; |
1168 | rcu_read_lock(); | |
1169 | rdev = rcu_dereference(conf->disks[i].rdev); | |
b2d444d7 | 1170 | if (rdev && test_bit(In_sync, &rdev->flags)) |
4e5314b5 N |
1171 | /* multiple read failures in one stripe */ |
1172 | md_error(conf->mddev, rdev); | |
9910f16a | 1173 | rcu_read_unlock(); |
4e5314b5 N |
1174 | } |
1175 | ||
72626685 | 1176 | spin_lock_irq(&conf->device_lock); |
1da177e4 LT |
1177 | /* fail all writes first */ |
1178 | bi = sh->dev[i].towrite; | |
1179 | sh->dev[i].towrite = NULL; | |
72626685 | 1180 | if (bi) { to_write--; bitmap_end = 1; } |
1da177e4 LT |
1181 | |
1182 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1183 | wake_up(&conf->wait_for_overlap); | |
1184 | ||
1185 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1186 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1187 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1188 | if (--bi->bi_phys_segments == 0) { | |
1189 | md_write_end(conf->mddev); | |
1190 | bi->bi_next = return_bi; | |
1191 | return_bi = bi; | |
1192 | } | |
1193 | bi = nextbi; | |
1194 | } | |
1195 | /* and fail all 'written' */ | |
1196 | bi = sh->dev[i].written; | |
1197 | sh->dev[i].written = NULL; | |
72626685 | 1198 | if (bi) bitmap_end = 1; |
1da177e4 LT |
1199 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { |
1200 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | |
1201 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1202 | if (--bi->bi_phys_segments == 0) { | |
1203 | md_write_end(conf->mddev); | |
1204 | bi->bi_next = return_bi; | |
1205 | return_bi = bi; | |
1206 | } | |
1207 | bi = bi2; | |
1208 | } | |
1209 | ||
1210 | /* fail any reads if this device is non-operational */ | |
4e5314b5 N |
1211 | if (!test_bit(R5_Insync, &sh->dev[i].flags) || |
1212 | test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
1da177e4 LT |
1213 | bi = sh->dev[i].toread; |
1214 | sh->dev[i].toread = NULL; | |
1215 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1216 | wake_up(&conf->wait_for_overlap); | |
1217 | if (bi) to_read--; | |
1218 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1219 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1220 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1221 | if (--bi->bi_phys_segments == 0) { | |
1222 | bi->bi_next = return_bi; | |
1223 | return_bi = bi; | |
1224 | } | |
1225 | bi = nextbi; | |
1226 | } | |
1227 | } | |
72626685 N |
1228 | spin_unlock_irq(&conf->device_lock); |
1229 | if (bitmap_end) | |
1230 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1231 | STRIPE_SECTORS, 0, 0); | |
1da177e4 | 1232 | } |
1da177e4 LT |
1233 | } |
1234 | if (failed > 1 && syncing) { | |
1235 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
1236 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1237 | syncing = 0; | |
1238 | } | |
1239 | ||
1240 | /* might be able to return some write requests if the parity block | |
1241 | * is safe, or on a failed drive | |
1242 | */ | |
1243 | dev = &sh->dev[sh->pd_idx]; | |
1244 | if ( written && | |
1245 | ( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) && | |
1246 | test_bit(R5_UPTODATE, &dev->flags)) | |
1247 | || (failed == 1 && failed_num == sh->pd_idx)) | |
1248 | ) { | |
1249 | /* any written block on an uptodate or failed drive can be returned. | |
1250 | * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but | |
1251 | * never LOCKED, so we don't need to test 'failed' directly. | |
1252 | */ | |
1253 | for (i=disks; i--; ) | |
1254 | if (sh->dev[i].written) { | |
1255 | dev = &sh->dev[i]; | |
1256 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1257 | test_bit(R5_UPTODATE, &dev->flags) ) { | |
1258 | /* We can return any write requests */ | |
1259 | struct bio *wbi, *wbi2; | |
72626685 | 1260 | int bitmap_end = 0; |
1da177e4 LT |
1261 | PRINTK("Return write for disc %d\n", i); |
1262 | spin_lock_irq(&conf->device_lock); | |
1263 | wbi = dev->written; | |
1264 | dev->written = NULL; | |
1265 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1266 | wbi2 = r5_next_bio(wbi, dev->sector); | |
1267 | if (--wbi->bi_phys_segments == 0) { | |
1268 | md_write_end(conf->mddev); | |
1269 | wbi->bi_next = return_bi; | |
1270 | return_bi = wbi; | |
1271 | } | |
1272 | wbi = wbi2; | |
1273 | } | |
72626685 N |
1274 | if (dev->towrite == NULL) |
1275 | bitmap_end = 1; | |
1da177e4 | 1276 | spin_unlock_irq(&conf->device_lock); |
72626685 N |
1277 | if (bitmap_end) |
1278 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1279 | STRIPE_SECTORS, | |
1280 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); | |
1da177e4 LT |
1281 | } |
1282 | } | |
1283 | } | |
1284 | ||
1285 | /* Now we might consider reading some blocks, either to check/generate | |
1286 | * parity, or to satisfy requests | |
1287 | * or to load a block that is being partially written. | |
1288 | */ | |
ccfcc3c1 | 1289 | if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) { |
1da177e4 LT |
1290 | for (i=disks; i--;) { |
1291 | dev = &sh->dev[i]; | |
1292 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1293 | (dev->toread || | |
1294 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1295 | syncing || | |
ccfcc3c1 | 1296 | expanding || |
1da177e4 LT |
1297 | (failed && (sh->dev[failed_num].toread || |
1298 | (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags)))) | |
1299 | ) | |
1300 | ) { | |
1301 | /* we would like to get this block, possibly | |
1302 | * by computing it, but we might not be able to | |
1303 | */ | |
1304 | if (uptodate == disks-1) { | |
1305 | PRINTK("Computing block %d\n", i); | |
1306 | compute_block(sh, i); | |
1307 | uptodate++; | |
1308 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1309 | set_bit(R5_LOCKED, &dev->flags); | |
1310 | set_bit(R5_Wantread, &dev->flags); | |
1311 | #if 0 | |
1312 | /* if I am just reading this block and we don't have | |
1313 | a failed drive, or any pending writes then sidestep the cache */ | |
1314 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && | |
1315 | ! syncing && !failed && !to_write) { | |
1316 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; | |
1317 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; | |
1318 | } | |
1319 | #endif | |
1320 | locked++; | |
1321 | PRINTK("Reading block %d (sync=%d)\n", | |
1322 | i, syncing); | |
1da177e4 LT |
1323 | } |
1324 | } | |
1325 | } | |
1326 | set_bit(STRIPE_HANDLE, &sh->state); | |
1327 | } | |
1328 | ||
1329 | /* now to consider writing and what else, if anything should be read */ | |
1330 | if (to_write) { | |
1331 | int rmw=0, rcw=0; | |
1332 | for (i=disks ; i--;) { | |
1333 | /* would I have to read this buffer for read_modify_write */ | |
1334 | dev = &sh->dev[i]; | |
1335 | if ((dev->towrite || i == sh->pd_idx) && | |
1336 | (!test_bit(R5_LOCKED, &dev->flags) | |
1337 | #if 0 | |
1338 | || sh->bh_page[i]!=bh->b_page | |
1339 | #endif | |
1340 | ) && | |
1341 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1342 | if (test_bit(R5_Insync, &dev->flags) | |
1343 | /* && !(!mddev->insync && i == sh->pd_idx) */ | |
1344 | ) | |
1345 | rmw++; | |
1346 | else rmw += 2*disks; /* cannot read it */ | |
1347 | } | |
1348 | /* Would I have to read this buffer for reconstruct_write */ | |
1349 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && | |
1350 | (!test_bit(R5_LOCKED, &dev->flags) | |
1351 | #if 0 | |
1352 | || sh->bh_page[i] != bh->b_page | |
1353 | #endif | |
1354 | ) && | |
1355 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1356 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
1357 | else rcw += 2*disks; | |
1358 | } | |
1359 | } | |
1360 | PRINTK("for sector %llu, rmw=%d rcw=%d\n", | |
1361 | (unsigned long long)sh->sector, rmw, rcw); | |
1362 | set_bit(STRIPE_HANDLE, &sh->state); | |
1363 | if (rmw < rcw && rmw > 0) | |
1364 | /* prefer read-modify-write, but need to get some data */ | |
1365 | for (i=disks; i--;) { | |
1366 | dev = &sh->dev[i]; | |
1367 | if ((dev->towrite || i == sh->pd_idx) && | |
1368 | !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1369 | test_bit(R5_Insync, &dev->flags)) { | |
1370 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1371 | { | |
1372 | PRINTK("Read_old block %d for r-m-w\n", i); | |
1373 | set_bit(R5_LOCKED, &dev->flags); | |
1374 | set_bit(R5_Wantread, &dev->flags); | |
1375 | locked++; | |
1376 | } else { | |
1377 | set_bit(STRIPE_DELAYED, &sh->state); | |
1378 | set_bit(STRIPE_HANDLE, &sh->state); | |
1379 | } | |
1380 | } | |
1381 | } | |
1382 | if (rcw <= rmw && rcw > 0) | |
1383 | /* want reconstruct write, but need to get some data */ | |
1384 | for (i=disks; i--;) { | |
1385 | dev = &sh->dev[i]; | |
1386 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && | |
1387 | !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1388 | test_bit(R5_Insync, &dev->flags)) { | |
1389 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1390 | { | |
1391 | PRINTK("Read_old block %d for Reconstruct\n", i); | |
1392 | set_bit(R5_LOCKED, &dev->flags); | |
1393 | set_bit(R5_Wantread, &dev->flags); | |
1394 | locked++; | |
1395 | } else { | |
1396 | set_bit(STRIPE_DELAYED, &sh->state); | |
1397 | set_bit(STRIPE_HANDLE, &sh->state); | |
1398 | } | |
1399 | } | |
1400 | } | |
1401 | /* now if nothing is locked, and if we have enough data, we can start a write request */ | |
72626685 N |
1402 | if (locked == 0 && (rcw == 0 ||rmw == 0) && |
1403 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | |
1da177e4 LT |
1404 | PRINTK("Computing parity...\n"); |
1405 | compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); | |
1406 | /* now every locked buffer is ready to be written */ | |
1407 | for (i=disks; i--;) | |
1408 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | |
1409 | PRINTK("Writing block %d\n", i); | |
1410 | locked++; | |
1411 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
1412 | if (!test_bit(R5_Insync, &sh->dev[i].flags) | |
1413 | || (i==sh->pd_idx && failed == 0)) | |
1414 | set_bit(STRIPE_INSYNC, &sh->state); | |
1415 | } | |
1416 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
1417 | atomic_dec(&conf->preread_active_stripes); | |
1418 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
1419 | md_wakeup_thread(conf->mddev->thread); | |
1420 | } | |
1421 | } | |
1422 | } | |
1423 | ||
1424 | /* maybe we need to check and possibly fix the parity for this stripe | |
1425 | * Any reads will already have been scheduled, so we just see if enough data | |
1426 | * is available | |
1427 | */ | |
1428 | if (syncing && locked == 0 && | |
14f8d26b | 1429 | !test_bit(STRIPE_INSYNC, &sh->state)) { |
1da177e4 LT |
1430 | set_bit(STRIPE_HANDLE, &sh->state); |
1431 | if (failed == 0) { | |
1432 | char *pagea; | |
1433 | if (uptodate != disks) | |
1434 | BUG(); | |
1435 | compute_parity(sh, CHECK_PARITY); | |
1436 | uptodate--; | |
1437 | pagea = page_address(sh->dev[sh->pd_idx].page); | |
1438 | if ((*(u32*)pagea) == 0 && | |
1439 | !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) { | |
1440 | /* parity is correct (on disc, not in buffer any more) */ | |
1441 | set_bit(STRIPE_INSYNC, &sh->state); | |
9d88883e N |
1442 | } else { |
1443 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | |
1444 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | |
1445 | /* don't try to repair!! */ | |
1446 | set_bit(STRIPE_INSYNC, &sh->state); | |
14f8d26b N |
1447 | else { |
1448 | compute_block(sh, sh->pd_idx); | |
1449 | uptodate++; | |
1450 | } | |
1da177e4 LT |
1451 | } |
1452 | } | |
1453 | if (!test_bit(STRIPE_INSYNC, &sh->state)) { | |
14f8d26b | 1454 | /* either failed parity check, or recovery is happening */ |
1da177e4 LT |
1455 | if (failed==0) |
1456 | failed_num = sh->pd_idx; | |
1da177e4 | 1457 | dev = &sh->dev[failed_num]; |
14f8d26b N |
1458 | BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); |
1459 | BUG_ON(uptodate != disks); | |
1460 | ||
1da177e4 LT |
1461 | set_bit(R5_LOCKED, &dev->flags); |
1462 | set_bit(R5_Wantwrite, &dev->flags); | |
72626685 | 1463 | clear_bit(STRIPE_DEGRADED, &sh->state); |
1da177e4 LT |
1464 | locked++; |
1465 | set_bit(STRIPE_INSYNC, &sh->state); | |
1da177e4 LT |
1466 | } |
1467 | } | |
1468 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | |
1469 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
1470 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1471 | } | |
4e5314b5 N |
1472 | |
1473 | /* If the failed drive is just a ReadError, then we might need to progress | |
1474 | * the repair/check process | |
1475 | */ | |
ba22dcbf N |
1476 | if (failed == 1 && ! conf->mddev->ro && |
1477 | test_bit(R5_ReadError, &sh->dev[failed_num].flags) | |
4e5314b5 N |
1478 | && !test_bit(R5_LOCKED, &sh->dev[failed_num].flags) |
1479 | && test_bit(R5_UPTODATE, &sh->dev[failed_num].flags) | |
1480 | ) { | |
1481 | dev = &sh->dev[failed_num]; | |
1482 | if (!test_bit(R5_ReWrite, &dev->flags)) { | |
1483 | set_bit(R5_Wantwrite, &dev->flags); | |
1484 | set_bit(R5_ReWrite, &dev->flags); | |
1485 | set_bit(R5_LOCKED, &dev->flags); | |
ccfcc3c1 | 1486 | locked++; |
4e5314b5 N |
1487 | } else { |
1488 | /* let's read it back */ | |
1489 | set_bit(R5_Wantread, &dev->flags); | |
1490 | set_bit(R5_LOCKED, &dev->flags); | |
ccfcc3c1 | 1491 | locked++; |
4e5314b5 N |
1492 | } |
1493 | } | |
1494 | ||
ccfcc3c1 N |
1495 | if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { |
1496 | /* Need to write out all blocks after computing parity */ | |
1497 | sh->disks = conf->raid_disks; | |
1498 | sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); | |
1499 | compute_parity(sh, RECONSTRUCT_WRITE); | |
1500 | for (i= conf->raid_disks; i--;) { | |
1501 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
1502 | locked++; | |
1503 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
1504 | } | |
1505 | clear_bit(STRIPE_EXPANDING, &sh->state); | |
1506 | } else if (expanded) { | |
1507 | clear_bit(STRIPE_EXPAND_READY, &sh->state); | |
f6705578 | 1508 | atomic_dec(&conf->reshape_stripes); |
ccfcc3c1 N |
1509 | wake_up(&conf->wait_for_overlap); |
1510 | md_done_sync(conf->mddev, STRIPE_SECTORS, 1); | |
1511 | } | |
1512 | ||
1513 | if (expanding && locked == 0) { | |
1514 | /* We have read all the blocks in this stripe and now we need to | |
1515 | * copy some of them into a target stripe for expand. | |
1516 | */ | |
1517 | clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
1518 | for (i=0; i< sh->disks; i++) | |
1519 | if (i != sh->pd_idx) { | |
1520 | int dd_idx, pd_idx, j; | |
1521 | struct stripe_head *sh2; | |
1522 | ||
1523 | sector_t bn = compute_blocknr(sh, i); | |
1524 | sector_t s = raid5_compute_sector(bn, conf->raid_disks, | |
1525 | conf->raid_disks-1, | |
1526 | &dd_idx, &pd_idx, conf); | |
1527 | sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1); | |
1528 | if (sh2 == NULL) | |
1529 | /* so far only the early blocks of this stripe | |
1530 | * have been requested. When later blocks | |
1531 | * get requested, we will try again | |
1532 | */ | |
1533 | continue; | |
1534 | if(!test_bit(STRIPE_EXPANDING, &sh2->state) || | |
1535 | test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { | |
1536 | /* must have already done this block */ | |
1537 | release_stripe(sh2); | |
1538 | continue; | |
1539 | } | |
1540 | memcpy(page_address(sh2->dev[dd_idx].page), | |
1541 | page_address(sh->dev[i].page), | |
1542 | STRIPE_SIZE); | |
1543 | set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); | |
1544 | set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); | |
1545 | for (j=0; j<conf->raid_disks; j++) | |
1546 | if (j != sh2->pd_idx && | |
1547 | !test_bit(R5_Expanded, &sh2->dev[j].flags)) | |
1548 | break; | |
1549 | if (j == conf->raid_disks) { | |
1550 | set_bit(STRIPE_EXPAND_READY, &sh2->state); | |
1551 | set_bit(STRIPE_HANDLE, &sh2->state); | |
1552 | } | |
1553 | release_stripe(sh2); | |
1554 | } | |
1555 | } | |
1556 | ||
1da177e4 LT |
1557 | spin_unlock(&sh->lock); |
1558 | ||
1559 | while ((bi=return_bi)) { | |
1560 | int bytes = bi->bi_size; | |
1561 | ||
1562 | return_bi = bi->bi_next; | |
1563 | bi->bi_next = NULL; | |
1564 | bi->bi_size = 0; | |
1565 | bi->bi_end_io(bi, bytes, 0); | |
1566 | } | |
1567 | for (i=disks; i-- ;) { | |
1568 | int rw; | |
1569 | struct bio *bi; | |
1570 | mdk_rdev_t *rdev; | |
1571 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | |
1572 | rw = 1; | |
1573 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | |
1574 | rw = 0; | |
1575 | else | |
1576 | continue; | |
1577 | ||
1578 | bi = &sh->dev[i].req; | |
1579 | ||
1580 | bi->bi_rw = rw; | |
1581 | if (rw) | |
1582 | bi->bi_end_io = raid5_end_write_request; | |
1583 | else | |
1584 | bi->bi_end_io = raid5_end_read_request; | |
1585 | ||
1586 | rcu_read_lock(); | |
d6065f7b | 1587 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1588 | if (rdev && test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
1589 | rdev = NULL; |
1590 | if (rdev) | |
1591 | atomic_inc(&rdev->nr_pending); | |
1592 | rcu_read_unlock(); | |
1593 | ||
1594 | if (rdev) { | |
ccfcc3c1 | 1595 | if (syncing || expanding || expanded) |
1da177e4 LT |
1596 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
1597 | ||
1598 | bi->bi_bdev = rdev->bdev; | |
1599 | PRINTK("for %llu schedule op %ld on disc %d\n", | |
1600 | (unsigned long long)sh->sector, bi->bi_rw, i); | |
1601 | atomic_inc(&sh->count); | |
1602 | bi->bi_sector = sh->sector + rdev->data_offset; | |
1603 | bi->bi_flags = 1 << BIO_UPTODATE; | |
1604 | bi->bi_vcnt = 1; | |
1605 | bi->bi_max_vecs = 1; | |
1606 | bi->bi_idx = 0; | |
1607 | bi->bi_io_vec = &sh->dev[i].vec; | |
1608 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | |
1609 | bi->bi_io_vec[0].bv_offset = 0; | |
1610 | bi->bi_size = STRIPE_SIZE; | |
1611 | bi->bi_next = NULL; | |
4dbcdc75 N |
1612 | if (rw == WRITE && |
1613 | test_bit(R5_ReWrite, &sh->dev[i].flags)) | |
1614 | atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); | |
1da177e4 LT |
1615 | generic_make_request(bi); |
1616 | } else { | |
72626685 N |
1617 | if (rw == 1) |
1618 | set_bit(STRIPE_DEGRADED, &sh->state); | |
1da177e4 LT |
1619 | PRINTK("skip op %ld on disc %d for sector %llu\n", |
1620 | bi->bi_rw, i, (unsigned long long)sh->sector); | |
1621 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1622 | set_bit(STRIPE_HANDLE, &sh->state); | |
1623 | } | |
1624 | } | |
1625 | } | |
1626 | ||
858119e1 | 1627 | static void raid5_activate_delayed(raid5_conf_t *conf) |
1da177e4 LT |
1628 | { |
1629 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | |
1630 | while (!list_empty(&conf->delayed_list)) { | |
1631 | struct list_head *l = conf->delayed_list.next; | |
1632 | struct stripe_head *sh; | |
1633 | sh = list_entry(l, struct stripe_head, lru); | |
1634 | list_del_init(l); | |
1635 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1636 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1637 | atomic_inc(&conf->preread_active_stripes); | |
1638 | list_add_tail(&sh->lru, &conf->handle_list); | |
1639 | } | |
1640 | } | |
1641 | } | |
1642 | ||
858119e1 | 1643 | static void activate_bit_delay(raid5_conf_t *conf) |
72626685 N |
1644 | { |
1645 | /* device_lock is held */ | |
1646 | struct list_head head; | |
1647 | list_add(&head, &conf->bitmap_list); | |
1648 | list_del_init(&conf->bitmap_list); | |
1649 | while (!list_empty(&head)) { | |
1650 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | |
1651 | list_del_init(&sh->lru); | |
1652 | atomic_inc(&sh->count); | |
1653 | __release_stripe(conf, sh); | |
1654 | } | |
1655 | } | |
1656 | ||
1da177e4 LT |
1657 | static void unplug_slaves(mddev_t *mddev) |
1658 | { | |
1659 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1660 | int i; | |
1661 | ||
1662 | rcu_read_lock(); | |
1663 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 1664 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1665 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
1da177e4 LT |
1666 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
1667 | ||
1668 | atomic_inc(&rdev->nr_pending); | |
1669 | rcu_read_unlock(); | |
1670 | ||
1671 | if (r_queue->unplug_fn) | |
1672 | r_queue->unplug_fn(r_queue); | |
1673 | ||
1674 | rdev_dec_pending(rdev, mddev); | |
1675 | rcu_read_lock(); | |
1676 | } | |
1677 | } | |
1678 | rcu_read_unlock(); | |
1679 | } | |
1680 | ||
1681 | static void raid5_unplug_device(request_queue_t *q) | |
1682 | { | |
1683 | mddev_t *mddev = q->queuedata; | |
1684 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1685 | unsigned long flags; | |
1686 | ||
1687 | spin_lock_irqsave(&conf->device_lock, flags); | |
1688 | ||
72626685 N |
1689 | if (blk_remove_plug(q)) { |
1690 | conf->seq_flush++; | |
1da177e4 | 1691 | raid5_activate_delayed(conf); |
72626685 | 1692 | } |
1da177e4 LT |
1693 | md_wakeup_thread(mddev->thread); |
1694 | ||
1695 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1696 | ||
1697 | unplug_slaves(mddev); | |
1698 | } | |
1699 | ||
1700 | static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk, | |
1701 | sector_t *error_sector) | |
1702 | { | |
1703 | mddev_t *mddev = q->queuedata; | |
1704 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1705 | int i, ret = 0; | |
1706 | ||
1707 | rcu_read_lock(); | |
1708 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 1709 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1710 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
1711 | struct block_device *bdev = rdev->bdev; |
1712 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
1713 | ||
1714 | if (!r_queue->issue_flush_fn) | |
1715 | ret = -EOPNOTSUPP; | |
1716 | else { | |
1717 | atomic_inc(&rdev->nr_pending); | |
1718 | rcu_read_unlock(); | |
1719 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
1720 | error_sector); | |
1721 | rdev_dec_pending(rdev, mddev); | |
1722 | rcu_read_lock(); | |
1723 | } | |
1724 | } | |
1725 | } | |
1726 | rcu_read_unlock(); | |
1727 | return ret; | |
1728 | } | |
1729 | ||
1730 | static inline void raid5_plug_device(raid5_conf_t *conf) | |
1731 | { | |
1732 | spin_lock_irq(&conf->device_lock); | |
1733 | blk_plug_device(conf->mddev->queue); | |
1734 | spin_unlock_irq(&conf->device_lock); | |
1735 | } | |
1736 | ||
7ecaa1e6 | 1737 | static int make_request(request_queue_t *q, struct bio * bi) |
1da177e4 LT |
1738 | { |
1739 | mddev_t *mddev = q->queuedata; | |
1740 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1da177e4 LT |
1741 | unsigned int dd_idx, pd_idx; |
1742 | sector_t new_sector; | |
1743 | sector_t logical_sector, last_sector; | |
1744 | struct stripe_head *sh; | |
a362357b | 1745 | const int rw = bio_data_dir(bi); |
f6344757 | 1746 | int remaining; |
1da177e4 | 1747 | |
e5dcdd80 N |
1748 | if (unlikely(bio_barrier(bi))) { |
1749 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); | |
1750 | return 0; | |
1751 | } | |
1752 | ||
3d310eb7 | 1753 | md_write_start(mddev, bi); |
06d91a5f | 1754 | |
a362357b JA |
1755 | disk_stat_inc(mddev->gendisk, ios[rw]); |
1756 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | |
1da177e4 LT |
1757 | |
1758 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
1759 | last_sector = bi->bi_sector + (bi->bi_size>>9); | |
1760 | bi->bi_next = NULL; | |
1761 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | |
06d91a5f | 1762 | |
1da177e4 LT |
1763 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
1764 | DEFINE_WAIT(w); | |
7ecaa1e6 | 1765 | int disks; |
b578d55f | 1766 | |
7ecaa1e6 | 1767 | retry: |
b578d55f | 1768 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); |
7ecaa1e6 N |
1769 | if (likely(conf->expand_progress == MaxSector)) |
1770 | disks = conf->raid_disks; | |
1771 | else { | |
df8e7f76 N |
1772 | /* spinlock is needed as expand_progress may be |
1773 | * 64bit on a 32bit platform, and so it might be | |
1774 | * possible to see a half-updated value | |
1775 | * Ofcourse expand_progress could change after | |
1776 | * the lock is dropped, so once we get a reference | |
1777 | * to the stripe that we think it is, we will have | |
1778 | * to check again. | |
1779 | */ | |
7ecaa1e6 N |
1780 | spin_lock_irq(&conf->device_lock); |
1781 | disks = conf->raid_disks; | |
1782 | if (logical_sector >= conf->expand_progress) | |
1783 | disks = conf->previous_raid_disks; | |
b578d55f N |
1784 | else { |
1785 | if (logical_sector >= conf->expand_lo) { | |
1786 | spin_unlock_irq(&conf->device_lock); | |
1787 | schedule(); | |
1788 | goto retry; | |
1789 | } | |
1790 | } | |
7ecaa1e6 N |
1791 | spin_unlock_irq(&conf->device_lock); |
1792 | } | |
1793 | new_sector = raid5_compute_sector(logical_sector, disks, disks - 1, | |
1794 | &dd_idx, &pd_idx, conf); | |
1da177e4 LT |
1795 | PRINTK("raid5: make_request, sector %llu logical %llu\n", |
1796 | (unsigned long long)new_sector, | |
1797 | (unsigned long long)logical_sector); | |
1798 | ||
7ecaa1e6 | 1799 | sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); |
1da177e4 | 1800 | if (sh) { |
7ecaa1e6 N |
1801 | if (unlikely(conf->expand_progress != MaxSector)) { |
1802 | /* expansion might have moved on while waiting for a | |
df8e7f76 N |
1803 | * stripe, so we must do the range check again. |
1804 | * Expansion could still move past after this | |
1805 | * test, but as we are holding a reference to | |
1806 | * 'sh', we know that if that happens, | |
1807 | * STRIPE_EXPANDING will get set and the expansion | |
1808 | * won't proceed until we finish with the stripe. | |
7ecaa1e6 N |
1809 | */ |
1810 | int must_retry = 0; | |
1811 | spin_lock_irq(&conf->device_lock); | |
1812 | if (logical_sector < conf->expand_progress && | |
1813 | disks == conf->previous_raid_disks) | |
1814 | /* mismatch, need to try again */ | |
1815 | must_retry = 1; | |
1816 | spin_unlock_irq(&conf->device_lock); | |
1817 | if (must_retry) { | |
1818 | release_stripe(sh); | |
1819 | goto retry; | |
1820 | } | |
1821 | } | |
e464eafd N |
1822 | /* FIXME what if we get a false positive because these |
1823 | * are being updated. | |
1824 | */ | |
1825 | if (logical_sector >= mddev->suspend_lo && | |
1826 | logical_sector < mddev->suspend_hi) { | |
1827 | release_stripe(sh); | |
1828 | schedule(); | |
1829 | goto retry; | |
1830 | } | |
7ecaa1e6 N |
1831 | |
1832 | if (test_bit(STRIPE_EXPANDING, &sh->state) || | |
1833 | !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | |
1834 | /* Stripe is busy expanding or | |
1835 | * add failed due to overlap. Flush everything | |
1da177e4 LT |
1836 | * and wait a while |
1837 | */ | |
1838 | raid5_unplug_device(mddev->queue); | |
1839 | release_stripe(sh); | |
1840 | schedule(); | |
1841 | goto retry; | |
1842 | } | |
1843 | finish_wait(&conf->wait_for_overlap, &w); | |
1844 | raid5_plug_device(conf); | |
1845 | handle_stripe(sh); | |
1846 | release_stripe(sh); | |
1da177e4 LT |
1847 | } else { |
1848 | /* cannot get stripe for read-ahead, just give-up */ | |
1849 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1850 | finish_wait(&conf->wait_for_overlap, &w); | |
1851 | break; | |
1852 | } | |
1853 | ||
1854 | } | |
1855 | spin_lock_irq(&conf->device_lock); | |
f6344757 N |
1856 | remaining = --bi->bi_phys_segments; |
1857 | spin_unlock_irq(&conf->device_lock); | |
1858 | if (remaining == 0) { | |
1da177e4 LT |
1859 | int bytes = bi->bi_size; |
1860 | ||
1861 | if ( bio_data_dir(bi) == WRITE ) | |
1862 | md_write_end(mddev); | |
1863 | bi->bi_size = 0; | |
1864 | bi->bi_end_io(bi, bytes, 0); | |
1865 | } | |
1da177e4 LT |
1866 | return 0; |
1867 | } | |
1868 | ||
1869 | /* FIXME go_faster isn't used */ | |
57afd89f | 1870 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1871 | { |
1872 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
1873 | struct stripe_head *sh; | |
ccfcc3c1 N |
1874 | int pd_idx; |
1875 | sector_t first_sector, last_sector; | |
1da177e4 LT |
1876 | int raid_disks = conf->raid_disks; |
1877 | int data_disks = raid_disks-1; | |
72626685 N |
1878 | sector_t max_sector = mddev->size << 1; |
1879 | int sync_blocks; | |
1da177e4 | 1880 | |
72626685 | 1881 | if (sector_nr >= max_sector) { |
1da177e4 LT |
1882 | /* just being told to finish up .. nothing much to do */ |
1883 | unplug_slaves(mddev); | |
29269553 N |
1884 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { |
1885 | end_reshape(conf); | |
1886 | return 0; | |
1887 | } | |
72626685 N |
1888 | |
1889 | if (mddev->curr_resync < max_sector) /* aborted */ | |
1890 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1891 | &sync_blocks, 1); | |
1892 | else /* compelted sync */ | |
1893 | conf->fullsync = 0; | |
1894 | bitmap_close_sync(mddev->bitmap); | |
1895 | ||
1da177e4 LT |
1896 | return 0; |
1897 | } | |
ccfcc3c1 N |
1898 | |
1899 | if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { | |
1900 | /* reshaping is quite different to recovery/resync so it is | |
1901 | * handled quite separately ... here. | |
1902 | * | |
1903 | * On each call to sync_request, we gather one chunk worth of | |
1904 | * destination stripes and flag them as expanding. | |
1905 | * Then we find all the source stripes and request reads. | |
1906 | * As the reads complete, handle_stripe will copy the data | |
1907 | * into the destination stripe and release that stripe. | |
1908 | */ | |
1909 | int i; | |
1910 | int dd_idx; | |
b578d55f | 1911 | sector_t writepos, safepos, gap; |
f6705578 N |
1912 | |
1913 | if (sector_nr == 0 && | |
1914 | conf->expand_progress != 0) { | |
1915 | /* restarting in the middle, skip the initial sectors */ | |
1916 | sector_nr = conf->expand_progress; | |
1917 | sector_div(sector_nr, conf->raid_disks-1); | |
1918 | *skipped = 1; | |
1919 | return sector_nr; | |
1920 | } | |
1921 | ||
b578d55f N |
1922 | /* we update the metadata when there is more than 3Meg |
1923 | * in the block range (that is rather arbitrary, should | |
1924 | * probably be time based) or when the data about to be | |
1925 | * copied would over-write the source of the data at | |
1926 | * the front of the range. | |
1927 | * i.e. one new_stripe forward from expand_progress new_maps | |
1928 | * to after where expand_lo old_maps to | |
1929 | */ | |
1930 | writepos = conf->expand_progress + | |
1931 | conf->chunk_size/512*(conf->raid_disks-1); | |
1932 | sector_div(writepos, conf->raid_disks-1); | |
1933 | safepos = conf->expand_lo; | |
1934 | sector_div(safepos, conf->previous_raid_disks-1); | |
1935 | gap = conf->expand_progress - conf->expand_lo; | |
1936 | ||
1937 | if (writepos >= safepos || | |
1938 | gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) { | |
1939 | /* Cannot proceed until we've updated the superblock... */ | |
1940 | wait_event(conf->wait_for_overlap, | |
1941 | atomic_read(&conf->reshape_stripes)==0); | |
1942 | mddev->reshape_position = conf->expand_progress; | |
1943 | mddev->sb_dirty = 1; | |
1944 | md_wakeup_thread(mddev->thread); | |
1945 | wait_event(mddev->sb_wait, mddev->sb_dirty == 0 || | |
1946 | kthread_should_stop()); | |
1947 | spin_lock_irq(&conf->device_lock); | |
1948 | conf->expand_lo = mddev->reshape_position; | |
1949 | spin_unlock_irq(&conf->device_lock); | |
1950 | wake_up(&conf->wait_for_overlap); | |
1951 | } | |
f6705578 | 1952 | |
ccfcc3c1 N |
1953 | for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { |
1954 | int j; | |
1955 | int skipped = 0; | |
1956 | pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks); | |
1957 | sh = get_active_stripe(conf, sector_nr+i, | |
1958 | conf->raid_disks, pd_idx, 0); | |
1959 | set_bit(STRIPE_EXPANDING, &sh->state); | |
f6705578 | 1960 | atomic_inc(&conf->reshape_stripes); |
ccfcc3c1 N |
1961 | /* If any of this stripe is beyond the end of the old |
1962 | * array, then we need to zero those blocks | |
1963 | */ | |
1964 | for (j=sh->disks; j--;) { | |
1965 | sector_t s; | |
1966 | if (j == sh->pd_idx) | |
1967 | continue; | |
1968 | s = compute_blocknr(sh, j); | |
1969 | if (s < (mddev->array_size<<1)) { | |
1970 | skipped = 1; | |
1971 | continue; | |
1972 | } | |
1973 | memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); | |
1974 | set_bit(R5_Expanded, &sh->dev[j].flags); | |
1975 | set_bit(R5_UPTODATE, &sh->dev[j].flags); | |
1976 | } | |
1977 | if (!skipped) { | |
1978 | set_bit(STRIPE_EXPAND_READY, &sh->state); | |
1979 | set_bit(STRIPE_HANDLE, &sh->state); | |
1980 | } | |
1981 | release_stripe(sh); | |
1982 | } | |
1983 | spin_lock_irq(&conf->device_lock); | |
1984 | conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1); | |
1985 | spin_unlock_irq(&conf->device_lock); | |
1986 | /* Ok, those stripe are ready. We can start scheduling | |
1987 | * reads on the source stripes. | |
1988 | * The source stripes are determined by mapping the first and last | |
1989 | * block on the destination stripes. | |
1990 | */ | |
1991 | raid_disks = conf->previous_raid_disks; | |
1992 | data_disks = raid_disks - 1; | |
1993 | first_sector = | |
1994 | raid5_compute_sector(sector_nr*(conf->raid_disks-1), | |
1995 | raid_disks, data_disks, | |
1996 | &dd_idx, &pd_idx, conf); | |
1997 | last_sector = | |
1998 | raid5_compute_sector((sector_nr+conf->chunk_size/512) | |
1999 | *(conf->raid_disks-1) -1, | |
2000 | raid_disks, data_disks, | |
2001 | &dd_idx, &pd_idx, conf); | |
2002 | if (last_sector >= (mddev->size<<1)) | |
2003 | last_sector = (mddev->size<<1)-1; | |
2004 | while (first_sector <= last_sector) { | |
2005 | pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks); | |
2006 | sh = get_active_stripe(conf, first_sector, | |
2007 | conf->previous_raid_disks, pd_idx, 0); | |
2008 | set_bit(STRIPE_EXPAND_SOURCE, &sh->state); | |
2009 | set_bit(STRIPE_HANDLE, &sh->state); | |
2010 | release_stripe(sh); | |
2011 | first_sector += STRIPE_SECTORS; | |
2012 | } | |
2013 | return conf->chunk_size>>9; | |
2014 | } | |
1da177e4 LT |
2015 | /* if there is 1 or more failed drives and we are trying |
2016 | * to resync, then assert that we are finished, because there is | |
2017 | * nothing we can do. | |
2018 | */ | |
2019 | if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
57afd89f N |
2020 | sector_t rv = (mddev->size << 1) - sector_nr; |
2021 | *skipped = 1; | |
1da177e4 LT |
2022 | return rv; |
2023 | } | |
72626685 | 2024 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
3855ad9f | 2025 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
72626685 N |
2026 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { |
2027 | /* we can skip this block, and probably more */ | |
2028 | sync_blocks /= STRIPE_SECTORS; | |
2029 | *skipped = 1; | |
2030 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | |
2031 | } | |
1da177e4 | 2032 | |
ccfcc3c1 | 2033 | pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks); |
7ecaa1e6 | 2034 | sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1); |
1da177e4 | 2035 | if (sh == NULL) { |
7ecaa1e6 | 2036 | sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); |
1da177e4 LT |
2037 | /* make sure we don't swamp the stripe cache if someone else |
2038 | * is trying to get access | |
2039 | */ | |
66c006a5 | 2040 | schedule_timeout_uninterruptible(1); |
1da177e4 | 2041 | } |
72626685 | 2042 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0); |
1da177e4 LT |
2043 | spin_lock(&sh->lock); |
2044 | set_bit(STRIPE_SYNCING, &sh->state); | |
2045 | clear_bit(STRIPE_INSYNC, &sh->state); | |
2046 | spin_unlock(&sh->lock); | |
2047 | ||
2048 | handle_stripe(sh); | |
2049 | release_stripe(sh); | |
2050 | ||
2051 | return STRIPE_SECTORS; | |
2052 | } | |
2053 | ||
2054 | /* | |
2055 | * This is our raid5 kernel thread. | |
2056 | * | |
2057 | * We scan the hash table for stripes which can be handled now. | |
2058 | * During the scan, completed stripes are saved for us by the interrupt | |
2059 | * handler, so that they will not have to wait for our next wakeup. | |
2060 | */ | |
2061 | static void raid5d (mddev_t *mddev) | |
2062 | { | |
2063 | struct stripe_head *sh; | |
2064 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
2065 | int handled; | |
2066 | ||
2067 | PRINTK("+++ raid5d active\n"); | |
2068 | ||
2069 | md_check_recovery(mddev); | |
1da177e4 LT |
2070 | |
2071 | handled = 0; | |
2072 | spin_lock_irq(&conf->device_lock); | |
2073 | while (1) { | |
2074 | struct list_head *first; | |
2075 | ||
72626685 N |
2076 | if (conf->seq_flush - conf->seq_write > 0) { |
2077 | int seq = conf->seq_flush; | |
700e432d | 2078 | spin_unlock_irq(&conf->device_lock); |
72626685 | 2079 | bitmap_unplug(mddev->bitmap); |
700e432d | 2080 | spin_lock_irq(&conf->device_lock); |
72626685 N |
2081 | conf->seq_write = seq; |
2082 | activate_bit_delay(conf); | |
2083 | } | |
2084 | ||
1da177e4 LT |
2085 | if (list_empty(&conf->handle_list) && |
2086 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && | |
2087 | !blk_queue_plugged(mddev->queue) && | |
2088 | !list_empty(&conf->delayed_list)) | |
2089 | raid5_activate_delayed(conf); | |
2090 | ||
2091 | if (list_empty(&conf->handle_list)) | |
2092 | break; | |
2093 | ||
2094 | first = conf->handle_list.next; | |
2095 | sh = list_entry(first, struct stripe_head, lru); | |
2096 | ||
2097 | list_del_init(first); | |
2098 | atomic_inc(&sh->count); | |
2099 | if (atomic_read(&sh->count)!= 1) | |
2100 | BUG(); | |
2101 | spin_unlock_irq(&conf->device_lock); | |
2102 | ||
2103 | handled++; | |
2104 | handle_stripe(sh); | |
2105 | release_stripe(sh); | |
2106 | ||
2107 | spin_lock_irq(&conf->device_lock); | |
2108 | } | |
2109 | PRINTK("%d stripes handled\n", handled); | |
2110 | ||
2111 | spin_unlock_irq(&conf->device_lock); | |
2112 | ||
2113 | unplug_slaves(mddev); | |
2114 | ||
2115 | PRINTK("--- raid5d inactive\n"); | |
2116 | } | |
2117 | ||
3f294f4f | 2118 | static ssize_t |
007583c9 | 2119 | raid5_show_stripe_cache_size(mddev_t *mddev, char *page) |
3f294f4f | 2120 | { |
007583c9 | 2121 | raid5_conf_t *conf = mddev_to_conf(mddev); |
96de1e66 N |
2122 | if (conf) |
2123 | return sprintf(page, "%d\n", conf->max_nr_stripes); | |
2124 | else | |
2125 | return 0; | |
3f294f4f N |
2126 | } |
2127 | ||
2128 | static ssize_t | |
007583c9 | 2129 | raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) |
3f294f4f | 2130 | { |
007583c9 | 2131 | raid5_conf_t *conf = mddev_to_conf(mddev); |
3f294f4f N |
2132 | char *end; |
2133 | int new; | |
2134 | if (len >= PAGE_SIZE) | |
2135 | return -EINVAL; | |
96de1e66 N |
2136 | if (!conf) |
2137 | return -ENODEV; | |
3f294f4f N |
2138 | |
2139 | new = simple_strtoul(page, &end, 10); | |
2140 | if (!*page || (*end && *end != '\n') ) | |
2141 | return -EINVAL; | |
2142 | if (new <= 16 || new > 32768) | |
2143 | return -EINVAL; | |
2144 | while (new < conf->max_nr_stripes) { | |
2145 | if (drop_one_stripe(conf)) | |
2146 | conf->max_nr_stripes--; | |
2147 | else | |
2148 | break; | |
2149 | } | |
2150 | while (new > conf->max_nr_stripes) { | |
2151 | if (grow_one_stripe(conf)) | |
2152 | conf->max_nr_stripes++; | |
2153 | else break; | |
2154 | } | |
2155 | return len; | |
2156 | } | |
007583c9 | 2157 | |
96de1e66 N |
2158 | static struct md_sysfs_entry |
2159 | raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, | |
2160 | raid5_show_stripe_cache_size, | |
2161 | raid5_store_stripe_cache_size); | |
3f294f4f N |
2162 | |
2163 | static ssize_t | |
96de1e66 | 2164 | stripe_cache_active_show(mddev_t *mddev, char *page) |
3f294f4f | 2165 | { |
007583c9 | 2166 | raid5_conf_t *conf = mddev_to_conf(mddev); |
96de1e66 N |
2167 | if (conf) |
2168 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); | |
2169 | else | |
2170 | return 0; | |
3f294f4f N |
2171 | } |
2172 | ||
96de1e66 N |
2173 | static struct md_sysfs_entry |
2174 | raid5_stripecache_active = __ATTR_RO(stripe_cache_active); | |
3f294f4f | 2175 | |
007583c9 | 2176 | static struct attribute *raid5_attrs[] = { |
3f294f4f N |
2177 | &raid5_stripecache_size.attr, |
2178 | &raid5_stripecache_active.attr, | |
2179 | NULL, | |
2180 | }; | |
007583c9 N |
2181 | static struct attribute_group raid5_attrs_group = { |
2182 | .name = NULL, | |
2183 | .attrs = raid5_attrs, | |
3f294f4f N |
2184 | }; |
2185 | ||
72626685 | 2186 | static int run(mddev_t *mddev) |
1da177e4 LT |
2187 | { |
2188 | raid5_conf_t *conf; | |
2189 | int raid_disk, memory; | |
2190 | mdk_rdev_t *rdev; | |
2191 | struct disk_info *disk; | |
2192 | struct list_head *tmp; | |
2193 | ||
2194 | if (mddev->level != 5 && mddev->level != 4) { | |
14f8d26b N |
2195 | printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n", |
2196 | mdname(mddev), mddev->level); | |
1da177e4 LT |
2197 | return -EIO; |
2198 | } | |
2199 | ||
f6705578 N |
2200 | if (mddev->reshape_position != MaxSector) { |
2201 | /* Check that we can continue the reshape. | |
2202 | * Currently only disks can change, it must | |
2203 | * increase, and we must be past the point where | |
2204 | * a stripe over-writes itself | |
2205 | */ | |
2206 | sector_t here_new, here_old; | |
2207 | int old_disks; | |
2208 | ||
2209 | if (mddev->new_level != mddev->level || | |
2210 | mddev->new_layout != mddev->layout || | |
2211 | mddev->new_chunk != mddev->chunk_size) { | |
2212 | printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n", | |
2213 | mdname(mddev)); | |
2214 | return -EINVAL; | |
2215 | } | |
2216 | if (mddev->delta_disks <= 0) { | |
2217 | printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n", | |
2218 | mdname(mddev)); | |
2219 | return -EINVAL; | |
2220 | } | |
2221 | old_disks = mddev->raid_disks - mddev->delta_disks; | |
2222 | /* reshape_position must be on a new-stripe boundary, and one | |
2223 | * further up in new geometry must map after here in old geometry. | |
2224 | */ | |
2225 | here_new = mddev->reshape_position; | |
2226 | if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) { | |
2227 | printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n"); | |
2228 | return -EINVAL; | |
2229 | } | |
2230 | /* here_new is the stripe we will write to */ | |
2231 | here_old = mddev->reshape_position; | |
2232 | sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1)); | |
2233 | /* here_old is the first stripe that we might need to read from */ | |
2234 | if (here_new >= here_old) { | |
2235 | /* Reading from the same stripe as writing to - bad */ | |
2236 | printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n"); | |
2237 | return -EINVAL; | |
2238 | } | |
2239 | printk(KERN_INFO "raid5: reshape will continue\n"); | |
2240 | /* OK, we should be able to continue; */ | |
2241 | } | |
2242 | ||
2243 | ||
b55e6bfc | 2244 | mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL); |
1da177e4 LT |
2245 | if ((conf = mddev->private) == NULL) |
2246 | goto abort; | |
f6705578 N |
2247 | if (mddev->reshape_position == MaxSector) { |
2248 | conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks; | |
2249 | } else { | |
2250 | conf->raid_disks = mddev->raid_disks; | |
2251 | conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; | |
2252 | } | |
2253 | ||
2254 | conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info), | |
b55e6bfc N |
2255 | GFP_KERNEL); |
2256 | if (!conf->disks) | |
2257 | goto abort; | |
9ffae0cf | 2258 | |
1da177e4 LT |
2259 | conf->mddev = mddev; |
2260 | ||
fccddba0 | 2261 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) |
1da177e4 | 2262 | goto abort; |
1da177e4 LT |
2263 | |
2264 | spin_lock_init(&conf->device_lock); | |
2265 | init_waitqueue_head(&conf->wait_for_stripe); | |
2266 | init_waitqueue_head(&conf->wait_for_overlap); | |
2267 | INIT_LIST_HEAD(&conf->handle_list); | |
2268 | INIT_LIST_HEAD(&conf->delayed_list); | |
72626685 | 2269 | INIT_LIST_HEAD(&conf->bitmap_list); |
1da177e4 LT |
2270 | INIT_LIST_HEAD(&conf->inactive_list); |
2271 | atomic_set(&conf->active_stripes, 0); | |
2272 | atomic_set(&conf->preread_active_stripes, 0); | |
2273 | ||
1da177e4 LT |
2274 | PRINTK("raid5: run(%s) called.\n", mdname(mddev)); |
2275 | ||
2276 | ITERATE_RDEV(mddev,rdev,tmp) { | |
2277 | raid_disk = rdev->raid_disk; | |
f6705578 | 2278 | if (raid_disk >= conf->raid_disks |
1da177e4 LT |
2279 | || raid_disk < 0) |
2280 | continue; | |
2281 | disk = conf->disks + raid_disk; | |
2282 | ||
2283 | disk->rdev = rdev; | |
2284 | ||
b2d444d7 | 2285 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
2286 | char b[BDEVNAME_SIZE]; |
2287 | printk(KERN_INFO "raid5: device %s operational as raid" | |
2288 | " disk %d\n", bdevname(rdev->bdev,b), | |
2289 | raid_disk); | |
2290 | conf->working_disks++; | |
2291 | } | |
2292 | } | |
2293 | ||
1da177e4 LT |
2294 | /* |
2295 | * 0 for a fully functional array, 1 for a degraded array. | |
2296 | */ | |
2297 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; | |
2298 | conf->mddev = mddev; | |
2299 | conf->chunk_size = mddev->chunk_size; | |
2300 | conf->level = mddev->level; | |
2301 | conf->algorithm = mddev->layout; | |
2302 | conf->max_nr_stripes = NR_STRIPES; | |
f6705578 | 2303 | conf->expand_progress = mddev->reshape_position; |
1da177e4 LT |
2304 | |
2305 | /* device size must be a multiple of chunk size */ | |
2306 | mddev->size &= ~(mddev->chunk_size/1024 -1); | |
b1581566 | 2307 | mddev->resync_max_sectors = mddev->size << 1; |
1da177e4 LT |
2308 | |
2309 | if (!conf->chunk_size || conf->chunk_size % 4) { | |
2310 | printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", | |
2311 | conf->chunk_size, mdname(mddev)); | |
2312 | goto abort; | |
2313 | } | |
2314 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | |
2315 | printk(KERN_ERR | |
2316 | "raid5: unsupported parity algorithm %d for %s\n", | |
2317 | conf->algorithm, mdname(mddev)); | |
2318 | goto abort; | |
2319 | } | |
2320 | if (mddev->degraded > 1) { | |
2321 | printk(KERN_ERR "raid5: not enough operational devices for %s" | |
2322 | " (%d/%d failed)\n", | |
2323 | mdname(mddev), conf->failed_disks, conf->raid_disks); | |
2324 | goto abort; | |
2325 | } | |
2326 | ||
2327 | if (mddev->degraded == 1 && | |
2328 | mddev->recovery_cp != MaxSector) { | |
6ff8d8ec N |
2329 | if (mddev->ok_start_degraded) |
2330 | printk(KERN_WARNING | |
2331 | "raid5: starting dirty degraded array: %s" | |
2332 | "- data corruption possible.\n", | |
2333 | mdname(mddev)); | |
2334 | else { | |
2335 | printk(KERN_ERR | |
2336 | "raid5: cannot start dirty degraded array for %s\n", | |
2337 | mdname(mddev)); | |
2338 | goto abort; | |
2339 | } | |
1da177e4 LT |
2340 | } |
2341 | ||
2342 | { | |
2343 | mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5"); | |
2344 | if (!mddev->thread) { | |
2345 | printk(KERN_ERR | |
2346 | "raid5: couldn't allocate thread for %s\n", | |
2347 | mdname(mddev)); | |
2348 | goto abort; | |
2349 | } | |
2350 | } | |
5036805b | 2351 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + |
1da177e4 LT |
2352 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; |
2353 | if (grow_stripes(conf, conf->max_nr_stripes)) { | |
2354 | printk(KERN_ERR | |
2355 | "raid5: couldn't allocate %dkB for buffers\n", memory); | |
2356 | shrink_stripes(conf); | |
2357 | md_unregister_thread(mddev->thread); | |
2358 | goto abort; | |
2359 | } else | |
2360 | printk(KERN_INFO "raid5: allocated %dkB for %s\n", | |
2361 | memory, mdname(mddev)); | |
2362 | ||
2363 | if (mddev->degraded == 0) | |
2364 | printk("raid5: raid level %d set %s active with %d out of %d" | |
2365 | " devices, algorithm %d\n", conf->level, mdname(mddev), | |
2366 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | |
2367 | conf->algorithm); | |
2368 | else | |
2369 | printk(KERN_ALERT "raid5: raid level %d set %s active with %d" | |
2370 | " out of %d devices, algorithm %d\n", conf->level, | |
2371 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
2372 | mddev->raid_disks, conf->algorithm); | |
2373 | ||
2374 | print_raid5_conf(conf); | |
2375 | ||
f6705578 N |
2376 | if (conf->expand_progress != MaxSector) { |
2377 | printk("...ok start reshape thread\n"); | |
b578d55f | 2378 | conf->expand_lo = conf->expand_progress; |
f6705578 N |
2379 | atomic_set(&conf->reshape_stripes, 0); |
2380 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); | |
2381 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); | |
2382 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); | |
2383 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); | |
2384 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, | |
2385 | "%s_reshape"); | |
2386 | /* FIXME if md_register_thread fails?? */ | |
2387 | md_wakeup_thread(mddev->sync_thread); | |
2388 | ||
2389 | } | |
2390 | ||
1da177e4 LT |
2391 | /* read-ahead size must cover two whole stripes, which is |
2392 | * 2 * (n-1) * chunksize where 'n' is the number of raid devices | |
2393 | */ | |
2394 | { | |
2395 | int stripe = (mddev->raid_disks-1) * mddev->chunk_size | |
2d1f3b5d | 2396 | / PAGE_SIZE; |
1da177e4 LT |
2397 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) |
2398 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
2399 | } | |
2400 | ||
2401 | /* Ok, everything is just fine now */ | |
007583c9 | 2402 | sysfs_create_group(&mddev->kobj, &raid5_attrs_group); |
7a5febe9 N |
2403 | |
2404 | mddev->queue->unplug_fn = raid5_unplug_device; | |
2405 | mddev->queue->issue_flush_fn = raid5_issue_flush; | |
f6705578 | 2406 | mddev->array_size = mddev->size * (conf->previous_raid_disks - 1); |
7a5febe9 | 2407 | |
1da177e4 LT |
2408 | return 0; |
2409 | abort: | |
2410 | if (conf) { | |
2411 | print_raid5_conf(conf); | |
b55e6bfc | 2412 | kfree(conf->disks); |
fccddba0 | 2413 | kfree(conf->stripe_hashtbl); |
1da177e4 LT |
2414 | kfree(conf); |
2415 | } | |
2416 | mddev->private = NULL; | |
2417 | printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); | |
2418 | return -EIO; | |
2419 | } | |
2420 | ||
2421 | ||
2422 | ||
3f294f4f | 2423 | static int stop(mddev_t *mddev) |
1da177e4 LT |
2424 | { |
2425 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
2426 | ||
2427 | md_unregister_thread(mddev->thread); | |
2428 | mddev->thread = NULL; | |
2429 | shrink_stripes(conf); | |
fccddba0 | 2430 | kfree(conf->stripe_hashtbl); |
1da177e4 | 2431 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
007583c9 | 2432 | sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); |
b55e6bfc | 2433 | kfree(conf->disks); |
96de1e66 | 2434 | kfree(conf); |
1da177e4 LT |
2435 | mddev->private = NULL; |
2436 | return 0; | |
2437 | } | |
2438 | ||
2439 | #if RAID5_DEBUG | |
2440 | static void print_sh (struct stripe_head *sh) | |
2441 | { | |
2442 | int i; | |
2443 | ||
2444 | printk("sh %llu, pd_idx %d, state %ld.\n", | |
2445 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | |
2446 | printk("sh %llu, count %d.\n", | |
2447 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | |
2448 | printk("sh %llu, ", (unsigned long long)sh->sector); | |
7ecaa1e6 | 2449 | for (i = 0; i < sh->disks; i++) { |
1da177e4 LT |
2450 | printk("(cache%d: %p %ld) ", |
2451 | i, sh->dev[i].page, sh->dev[i].flags); | |
2452 | } | |
2453 | printk("\n"); | |
2454 | } | |
2455 | ||
2456 | static void printall (raid5_conf_t *conf) | |
2457 | { | |
2458 | struct stripe_head *sh; | |
fccddba0 | 2459 | struct hlist_node *hn; |
1da177e4 LT |
2460 | int i; |
2461 | ||
2462 | spin_lock_irq(&conf->device_lock); | |
2463 | for (i = 0; i < NR_HASH; i++) { | |
fccddba0 | 2464 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { |
1da177e4 LT |
2465 | if (sh->raid_conf != conf) |
2466 | continue; | |
2467 | print_sh(sh); | |
2468 | } | |
2469 | } | |
2470 | spin_unlock_irq(&conf->device_lock); | |
2471 | } | |
2472 | #endif | |
2473 | ||
2474 | static void status (struct seq_file *seq, mddev_t *mddev) | |
2475 | { | |
2476 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
2477 | int i; | |
2478 | ||
2479 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | |
2480 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); | |
2481 | for (i = 0; i < conf->raid_disks; i++) | |
2482 | seq_printf (seq, "%s", | |
2483 | conf->disks[i].rdev && | |
b2d444d7 | 2484 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
2485 | seq_printf (seq, "]"); |
2486 | #if RAID5_DEBUG | |
2487 | #define D(x) \ | |
2488 | seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x)) | |
2489 | printall(conf); | |
2490 | #endif | |
2491 | } | |
2492 | ||
2493 | static void print_raid5_conf (raid5_conf_t *conf) | |
2494 | { | |
2495 | int i; | |
2496 | struct disk_info *tmp; | |
2497 | ||
2498 | printk("RAID5 conf printout:\n"); | |
2499 | if (!conf) { | |
2500 | printk("(conf==NULL)\n"); | |
2501 | return; | |
2502 | } | |
2503 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, | |
2504 | conf->working_disks, conf->failed_disks); | |
2505 | ||
2506 | for (i = 0; i < conf->raid_disks; i++) { | |
2507 | char b[BDEVNAME_SIZE]; | |
2508 | tmp = conf->disks + i; | |
2509 | if (tmp->rdev) | |
2510 | printk(" disk %d, o:%d, dev:%s\n", | |
b2d444d7 | 2511 | i, !test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
2512 | bdevname(tmp->rdev->bdev,b)); |
2513 | } | |
2514 | } | |
2515 | ||
2516 | static int raid5_spare_active(mddev_t *mddev) | |
2517 | { | |
2518 | int i; | |
2519 | raid5_conf_t *conf = mddev->private; | |
2520 | struct disk_info *tmp; | |
2521 | ||
2522 | for (i = 0; i < conf->raid_disks; i++) { | |
2523 | tmp = conf->disks + i; | |
2524 | if (tmp->rdev | |
b2d444d7 N |
2525 | && !test_bit(Faulty, &tmp->rdev->flags) |
2526 | && !test_bit(In_sync, &tmp->rdev->flags)) { | |
1da177e4 LT |
2527 | mddev->degraded--; |
2528 | conf->failed_disks--; | |
2529 | conf->working_disks++; | |
b2d444d7 | 2530 | set_bit(In_sync, &tmp->rdev->flags); |
1da177e4 LT |
2531 | } |
2532 | } | |
2533 | print_raid5_conf(conf); | |
2534 | return 0; | |
2535 | } | |
2536 | ||
2537 | static int raid5_remove_disk(mddev_t *mddev, int number) | |
2538 | { | |
2539 | raid5_conf_t *conf = mddev->private; | |
2540 | int err = 0; | |
2541 | mdk_rdev_t *rdev; | |
2542 | struct disk_info *p = conf->disks + number; | |
2543 | ||
2544 | print_raid5_conf(conf); | |
2545 | rdev = p->rdev; | |
2546 | if (rdev) { | |
b2d444d7 | 2547 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
2548 | atomic_read(&rdev->nr_pending)) { |
2549 | err = -EBUSY; | |
2550 | goto abort; | |
2551 | } | |
2552 | p->rdev = NULL; | |
fbd568a3 | 2553 | synchronize_rcu(); |
1da177e4 LT |
2554 | if (atomic_read(&rdev->nr_pending)) { |
2555 | /* lost the race, try later */ | |
2556 | err = -EBUSY; | |
2557 | p->rdev = rdev; | |
2558 | } | |
2559 | } | |
2560 | abort: | |
2561 | ||
2562 | print_raid5_conf(conf); | |
2563 | return err; | |
2564 | } | |
2565 | ||
2566 | static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
2567 | { | |
2568 | raid5_conf_t *conf = mddev->private; | |
2569 | int found = 0; | |
2570 | int disk; | |
2571 | struct disk_info *p; | |
2572 | ||
2573 | if (mddev->degraded > 1) | |
2574 | /* no point adding a device */ | |
2575 | return 0; | |
2576 | ||
2577 | /* | |
2578 | * find the disk ... | |
2579 | */ | |
f6705578 | 2580 | for (disk=0; disk < conf->raid_disks; disk++) |
1da177e4 | 2581 | if ((p=conf->disks + disk)->rdev == NULL) { |
b2d444d7 | 2582 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
2583 | rdev->raid_disk = disk; |
2584 | found = 1; | |
72626685 N |
2585 | if (rdev->saved_raid_disk != disk) |
2586 | conf->fullsync = 1; | |
d6065f7b | 2587 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
2588 | break; |
2589 | } | |
2590 | print_raid5_conf(conf); | |
2591 | return found; | |
2592 | } | |
2593 | ||
2594 | static int raid5_resize(mddev_t *mddev, sector_t sectors) | |
2595 | { | |
2596 | /* no resync is happening, and there is enough space | |
2597 | * on all devices, so we can resize. | |
2598 | * We need to make sure resync covers any new space. | |
2599 | * If the array is shrinking we should possibly wait until | |
2600 | * any io in the removed space completes, but it hardly seems | |
2601 | * worth it. | |
2602 | */ | |
2603 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | |
2604 | mddev->array_size = (sectors * (mddev->raid_disks-1))>>1; | |
2605 | set_capacity(mddev->gendisk, mddev->array_size << 1); | |
2606 | mddev->changed = 1; | |
2607 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | |
2608 | mddev->recovery_cp = mddev->size << 1; | |
2609 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
2610 | } | |
2611 | mddev->size = sectors /2; | |
4b5c7ae8 | 2612 | mddev->resync_max_sectors = sectors; |
1da177e4 LT |
2613 | return 0; |
2614 | } | |
2615 | ||
29269553 | 2616 | #ifdef CONFIG_MD_RAID5_RESHAPE |
63c70c4f | 2617 | static int raid5_check_reshape(mddev_t *mddev) |
29269553 N |
2618 | { |
2619 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
2620 | int err; | |
29269553 | 2621 | |
63c70c4f N |
2622 | if (mddev->delta_disks < 0 || |
2623 | mddev->new_level != mddev->level) | |
2624 | return -EINVAL; /* Cannot shrink array or change level yet */ | |
2625 | if (mddev->delta_disks == 0) | |
29269553 N |
2626 | return 0; /* nothing to do */ |
2627 | ||
2628 | /* Can only proceed if there are plenty of stripe_heads. | |
2629 | * We need a minimum of one full stripe,, and for sensible progress | |
2630 | * it is best to have about 4 times that. | |
2631 | * If we require 4 times, then the default 256 4K stripe_heads will | |
2632 | * allow for chunk sizes up to 256K, which is probably OK. | |
2633 | * If the chunk size is greater, user-space should request more | |
2634 | * stripe_heads first. | |
2635 | */ | |
63c70c4f N |
2636 | if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes || |
2637 | (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) { | |
29269553 N |
2638 | printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", |
2639 | (mddev->chunk_size / STRIPE_SIZE)*4); | |
2640 | return -ENOSPC; | |
2641 | } | |
2642 | ||
63c70c4f N |
2643 | err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks); |
2644 | if (err) | |
2645 | return err; | |
2646 | ||
2647 | /* looks like we might be able to manage this */ | |
2648 | return 0; | |
2649 | } | |
2650 | ||
2651 | static int raid5_start_reshape(mddev_t *mddev) | |
2652 | { | |
2653 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
2654 | mdk_rdev_t *rdev; | |
2655 | struct list_head *rtmp; | |
2656 | int spares = 0; | |
2657 | int added_devices = 0; | |
2658 | ||
2659 | if (mddev->degraded || | |
2660 | test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) | |
2661 | return -EBUSY; | |
2662 | ||
29269553 N |
2663 | ITERATE_RDEV(mddev, rdev, rtmp) |
2664 | if (rdev->raid_disk < 0 && | |
2665 | !test_bit(Faulty, &rdev->flags)) | |
2666 | spares++; | |
63c70c4f N |
2667 | |
2668 | if (spares < mddev->delta_disks-1) | |
29269553 N |
2669 | /* Not enough devices even to make a degraded array |
2670 | * of that size | |
2671 | */ | |
2672 | return -EINVAL; | |
2673 | ||
f6705578 | 2674 | atomic_set(&conf->reshape_stripes, 0); |
29269553 N |
2675 | spin_lock_irq(&conf->device_lock); |
2676 | conf->previous_raid_disks = conf->raid_disks; | |
63c70c4f | 2677 | conf->raid_disks += mddev->delta_disks; |
29269553 | 2678 | conf->expand_progress = 0; |
b578d55f | 2679 | conf->expand_lo = 0; |
29269553 N |
2680 | spin_unlock_irq(&conf->device_lock); |
2681 | ||
2682 | /* Add some new drives, as many as will fit. | |
2683 | * We know there are enough to make the newly sized array work. | |
2684 | */ | |
2685 | ITERATE_RDEV(mddev, rdev, rtmp) | |
2686 | if (rdev->raid_disk < 0 && | |
2687 | !test_bit(Faulty, &rdev->flags)) { | |
2688 | if (raid5_add_disk(mddev, rdev)) { | |
2689 | char nm[20]; | |
2690 | set_bit(In_sync, &rdev->flags); | |
2691 | conf->working_disks++; | |
2692 | added_devices++; | |
2693 | sprintf(nm, "rd%d", rdev->raid_disk); | |
2694 | sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); | |
2695 | } else | |
2696 | break; | |
2697 | } | |
2698 | ||
63c70c4f N |
2699 | mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices; |
2700 | mddev->raid_disks = conf->raid_disks; | |
f6705578 N |
2701 | mddev->reshape_position = 0; |
2702 | mddev->sb_dirty = 1; | |
2703 | ||
29269553 N |
2704 | clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); |
2705 | clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); | |
2706 | set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); | |
2707 | set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); | |
2708 | mddev->sync_thread = md_register_thread(md_do_sync, mddev, | |
2709 | "%s_reshape"); | |
2710 | if (!mddev->sync_thread) { | |
2711 | mddev->recovery = 0; | |
2712 | spin_lock_irq(&conf->device_lock); | |
2713 | mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; | |
2714 | conf->expand_progress = MaxSector; | |
2715 | spin_unlock_irq(&conf->device_lock); | |
2716 | return -EAGAIN; | |
2717 | } | |
2718 | md_wakeup_thread(mddev->sync_thread); | |
2719 | md_new_event(mddev); | |
2720 | return 0; | |
2721 | } | |
2722 | #endif | |
2723 | ||
2724 | static void end_reshape(raid5_conf_t *conf) | |
2725 | { | |
2726 | struct block_device *bdev; | |
2727 | ||
f6705578 N |
2728 | if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { |
2729 | conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1); | |
2730 | set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1); | |
2731 | conf->mddev->changed = 1; | |
2732 | ||
2733 | bdev = bdget_disk(conf->mddev->gendisk, 0); | |
2734 | if (bdev) { | |
2735 | mutex_lock(&bdev->bd_inode->i_mutex); | |
2736 | i_size_write(bdev->bd_inode, conf->mddev->array_size << 10); | |
2737 | mutex_unlock(&bdev->bd_inode->i_mutex); | |
2738 | bdput(bdev); | |
2739 | } | |
2740 | spin_lock_irq(&conf->device_lock); | |
2741 | conf->expand_progress = MaxSector; | |
2742 | spin_unlock_irq(&conf->device_lock); | |
2743 | conf->mddev->reshape_position = MaxSector; | |
29269553 | 2744 | } |
29269553 N |
2745 | } |
2746 | ||
72626685 N |
2747 | static void raid5_quiesce(mddev_t *mddev, int state) |
2748 | { | |
2749 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
2750 | ||
2751 | switch(state) { | |
e464eafd N |
2752 | case 2: /* resume for a suspend */ |
2753 | wake_up(&conf->wait_for_overlap); | |
2754 | break; | |
2755 | ||
72626685 N |
2756 | case 1: /* stop all writes */ |
2757 | spin_lock_irq(&conf->device_lock); | |
2758 | conf->quiesce = 1; | |
2759 | wait_event_lock_irq(conf->wait_for_stripe, | |
2760 | atomic_read(&conf->active_stripes) == 0, | |
2761 | conf->device_lock, /* nothing */); | |
2762 | spin_unlock_irq(&conf->device_lock); | |
2763 | break; | |
2764 | ||
2765 | case 0: /* re-enable writes */ | |
2766 | spin_lock_irq(&conf->device_lock); | |
2767 | conf->quiesce = 0; | |
2768 | wake_up(&conf->wait_for_stripe); | |
e464eafd | 2769 | wake_up(&conf->wait_for_overlap); |
72626685 N |
2770 | spin_unlock_irq(&conf->device_lock); |
2771 | break; | |
2772 | } | |
72626685 | 2773 | } |
b15c2e57 | 2774 | |
2604b703 | 2775 | static struct mdk_personality raid5_personality = |
1da177e4 LT |
2776 | { |
2777 | .name = "raid5", | |
2604b703 | 2778 | .level = 5, |
1da177e4 LT |
2779 | .owner = THIS_MODULE, |
2780 | .make_request = make_request, | |
2781 | .run = run, | |
2782 | .stop = stop, | |
2783 | .status = status, | |
2784 | .error_handler = error, | |
2785 | .hot_add_disk = raid5_add_disk, | |
2786 | .hot_remove_disk= raid5_remove_disk, | |
2787 | .spare_active = raid5_spare_active, | |
2788 | .sync_request = sync_request, | |
2789 | .resize = raid5_resize, | |
29269553 | 2790 | #ifdef CONFIG_MD_RAID5_RESHAPE |
63c70c4f N |
2791 | .check_reshape = raid5_check_reshape, |
2792 | .start_reshape = raid5_start_reshape, | |
29269553 | 2793 | #endif |
72626685 | 2794 | .quiesce = raid5_quiesce, |
1da177e4 LT |
2795 | }; |
2796 | ||
2604b703 | 2797 | static struct mdk_personality raid4_personality = |
1da177e4 | 2798 | { |
2604b703 N |
2799 | .name = "raid4", |
2800 | .level = 4, | |
2801 | .owner = THIS_MODULE, | |
2802 | .make_request = make_request, | |
2803 | .run = run, | |
2804 | .stop = stop, | |
2805 | .status = status, | |
2806 | .error_handler = error, | |
2807 | .hot_add_disk = raid5_add_disk, | |
2808 | .hot_remove_disk= raid5_remove_disk, | |
2809 | .spare_active = raid5_spare_active, | |
2810 | .sync_request = sync_request, | |
2811 | .resize = raid5_resize, | |
2812 | .quiesce = raid5_quiesce, | |
2813 | }; | |
2814 | ||
2815 | static int __init raid5_init(void) | |
2816 | { | |
2817 | register_md_personality(&raid5_personality); | |
2818 | register_md_personality(&raid4_personality); | |
2819 | return 0; | |
1da177e4 LT |
2820 | } |
2821 | ||
2604b703 | 2822 | static void raid5_exit(void) |
1da177e4 | 2823 | { |
2604b703 N |
2824 | unregister_md_personality(&raid5_personality); |
2825 | unregister_md_personality(&raid4_personality); | |
1da177e4 LT |
2826 | } |
2827 | ||
2828 | module_init(raid5_init); | |
2829 | module_exit(raid5_exit); | |
2830 | MODULE_LICENSE("GPL"); | |
2831 | MODULE_ALIAS("md-personality-4"); /* RAID5 */ | |
d9d166c2 N |
2832 | MODULE_ALIAS("md-raid5"); |
2833 | MODULE_ALIAS("md-raid4"); | |
2604b703 N |
2834 | MODULE_ALIAS("md-level-5"); |
2835 | MODULE_ALIAS("md-level-4"); |