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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> | |
25 | #include <asm/atomic.h> | |
26 | ||
72626685 N |
27 | #include <linux/raid/bitmap.h> |
28 | ||
1da177e4 LT |
29 | /* |
30 | * Stripe cache | |
31 | */ | |
32 | ||
33 | #define NR_STRIPES 256 | |
34 | #define STRIPE_SIZE PAGE_SIZE | |
35 | #define STRIPE_SHIFT (PAGE_SHIFT - 9) | |
36 | #define STRIPE_SECTORS (STRIPE_SIZE>>9) | |
37 | #define IO_THRESHOLD 1 | |
fccddba0 | 38 | #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) |
1da177e4 LT |
39 | #define HASH_MASK (NR_HASH - 1) |
40 | ||
fccddba0 | 41 | #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) |
1da177e4 LT |
42 | |
43 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector | |
44 | * order without overlap. There may be several bio's per stripe+device, and | |
45 | * a bio could span several devices. | |
46 | * When walking this list for a particular stripe+device, we must never proceed | |
47 | * beyond a bio that extends past this device, as the next bio might no longer | |
48 | * be valid. | |
49 | * This macro is used to determine the 'next' bio in the list, given the sector | |
50 | * of the current stripe+device | |
51 | */ | |
52 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) | |
53 | /* | |
54 | * The following can be used to debug the driver | |
55 | */ | |
56 | #define RAID5_DEBUG 0 | |
57 | #define RAID5_PARANOIA 1 | |
58 | #if RAID5_PARANOIA && defined(CONFIG_SMP) | |
59 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) | |
60 | #else | |
61 | # define CHECK_DEVLOCK() | |
62 | #endif | |
63 | ||
64 | #define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x))) | |
65 | #if RAID5_DEBUG | |
66 | #define inline | |
67 | #define __inline__ | |
68 | #endif | |
69 | ||
70 | static void print_raid5_conf (raid5_conf_t *conf); | |
71 | ||
858119e1 | 72 | static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) |
1da177e4 LT |
73 | { |
74 | if (atomic_dec_and_test(&sh->count)) { | |
75 | if (!list_empty(&sh->lru)) | |
76 | BUG(); | |
77 | if (atomic_read(&conf->active_stripes)==0) | |
78 | BUG(); | |
79 | if (test_bit(STRIPE_HANDLE, &sh->state)) { | |
80 | if (test_bit(STRIPE_DELAYED, &sh->state)) | |
81 | list_add_tail(&sh->lru, &conf->delayed_list); | |
72626685 N |
82 | else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
83 | conf->seq_write == sh->bm_seq) | |
84 | list_add_tail(&sh->lru, &conf->bitmap_list); | |
85 | else { | |
86 | clear_bit(STRIPE_BIT_DELAY, &sh->state); | |
1da177e4 | 87 | list_add_tail(&sh->lru, &conf->handle_list); |
72626685 | 88 | } |
1da177e4 LT |
89 | md_wakeup_thread(conf->mddev->thread); |
90 | } else { | |
91 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
92 | atomic_dec(&conf->preread_active_stripes); | |
93 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
94 | md_wakeup_thread(conf->mddev->thread); | |
95 | } | |
96 | list_add_tail(&sh->lru, &conf->inactive_list); | |
97 | atomic_dec(&conf->active_stripes); | |
98 | if (!conf->inactive_blocked || | |
5036805b | 99 | atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4)) |
1da177e4 LT |
100 | wake_up(&conf->wait_for_stripe); |
101 | } | |
102 | } | |
103 | } | |
104 | static void release_stripe(struct stripe_head *sh) | |
105 | { | |
106 | raid5_conf_t *conf = sh->raid_conf; | |
107 | unsigned long flags; | |
108 | ||
109 | spin_lock_irqsave(&conf->device_lock, flags); | |
110 | __release_stripe(conf, sh); | |
111 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
112 | } | |
113 | ||
fccddba0 | 114 | static inline void remove_hash(struct stripe_head *sh) |
1da177e4 LT |
115 | { |
116 | PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
117 | ||
fccddba0 | 118 | hlist_del_init(&sh->hash); |
1da177e4 LT |
119 | } |
120 | ||
858119e1 | 121 | static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) |
1da177e4 | 122 | { |
fccddba0 | 123 | struct hlist_head *hp = stripe_hash(conf, sh->sector); |
1da177e4 LT |
124 | |
125 | PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); | |
126 | ||
127 | CHECK_DEVLOCK(); | |
fccddba0 | 128 | hlist_add_head(&sh->hash, hp); |
1da177e4 LT |
129 | } |
130 | ||
131 | ||
132 | /* find an idle stripe, make sure it is unhashed, and return it. */ | |
133 | static struct stripe_head *get_free_stripe(raid5_conf_t *conf) | |
134 | { | |
135 | struct stripe_head *sh = NULL; | |
136 | struct list_head *first; | |
137 | ||
138 | CHECK_DEVLOCK(); | |
139 | if (list_empty(&conf->inactive_list)) | |
140 | goto out; | |
141 | first = conf->inactive_list.next; | |
142 | sh = list_entry(first, struct stripe_head, lru); | |
143 | list_del_init(first); | |
144 | remove_hash(sh); | |
145 | atomic_inc(&conf->active_stripes); | |
146 | out: | |
147 | return sh; | |
148 | } | |
149 | ||
150 | static void shrink_buffers(struct stripe_head *sh, int num) | |
151 | { | |
152 | struct page *p; | |
153 | int i; | |
154 | ||
155 | for (i=0; i<num ; i++) { | |
156 | p = sh->dev[i].page; | |
157 | if (!p) | |
158 | continue; | |
159 | sh->dev[i].page = NULL; | |
2d1f3b5d | 160 | put_page(p); |
1da177e4 LT |
161 | } |
162 | } | |
163 | ||
164 | static int grow_buffers(struct stripe_head *sh, int num) | |
165 | { | |
166 | int i; | |
167 | ||
168 | for (i=0; i<num; i++) { | |
169 | struct page *page; | |
170 | ||
171 | if (!(page = alloc_page(GFP_KERNEL))) { | |
172 | return 1; | |
173 | } | |
174 | sh->dev[i].page = page; | |
175 | } | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static void raid5_build_block (struct stripe_head *sh, int i); | |
180 | ||
858119e1 | 181 | static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) |
1da177e4 LT |
182 | { |
183 | raid5_conf_t *conf = sh->raid_conf; | |
184 | int disks = conf->raid_disks, i; | |
185 | ||
186 | if (atomic_read(&sh->count) != 0) | |
187 | BUG(); | |
188 | if (test_bit(STRIPE_HANDLE, &sh->state)) | |
189 | BUG(); | |
190 | ||
191 | CHECK_DEVLOCK(); | |
192 | PRINTK("init_stripe called, stripe %llu\n", | |
193 | (unsigned long long)sh->sector); | |
194 | ||
195 | remove_hash(sh); | |
196 | ||
197 | sh->sector = sector; | |
198 | sh->pd_idx = pd_idx; | |
199 | sh->state = 0; | |
200 | ||
201 | for (i=disks; i--; ) { | |
202 | struct r5dev *dev = &sh->dev[i]; | |
203 | ||
204 | if (dev->toread || dev->towrite || dev->written || | |
205 | test_bit(R5_LOCKED, &dev->flags)) { | |
206 | printk("sector=%llx i=%d %p %p %p %d\n", | |
207 | (unsigned long long)sh->sector, i, dev->toread, | |
208 | dev->towrite, dev->written, | |
209 | test_bit(R5_LOCKED, &dev->flags)); | |
210 | BUG(); | |
211 | } | |
212 | dev->flags = 0; | |
213 | raid5_build_block(sh, i); | |
214 | } | |
215 | insert_hash(conf, sh); | |
216 | } | |
217 | ||
218 | static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector) | |
219 | { | |
220 | struct stripe_head *sh; | |
fccddba0 | 221 | struct hlist_node *hn; |
1da177e4 LT |
222 | |
223 | CHECK_DEVLOCK(); | |
224 | PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); | |
fccddba0 | 225 | hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) |
1da177e4 LT |
226 | if (sh->sector == sector) |
227 | return sh; | |
228 | PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); | |
229 | return NULL; | |
230 | } | |
231 | ||
232 | static void unplug_slaves(mddev_t *mddev); | |
233 | static void raid5_unplug_device(request_queue_t *q); | |
234 | ||
235 | static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, | |
236 | int pd_idx, int noblock) | |
237 | { | |
238 | struct stripe_head *sh; | |
239 | ||
240 | PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); | |
241 | ||
242 | spin_lock_irq(&conf->device_lock); | |
243 | ||
244 | do { | |
72626685 N |
245 | wait_event_lock_irq(conf->wait_for_stripe, |
246 | conf->quiesce == 0, | |
247 | conf->device_lock, /* nothing */); | |
1da177e4 LT |
248 | sh = __find_stripe(conf, sector); |
249 | if (!sh) { | |
250 | if (!conf->inactive_blocked) | |
251 | sh = get_free_stripe(conf); | |
252 | if (noblock && sh == NULL) | |
253 | break; | |
254 | if (!sh) { | |
255 | conf->inactive_blocked = 1; | |
256 | wait_event_lock_irq(conf->wait_for_stripe, | |
257 | !list_empty(&conf->inactive_list) && | |
5036805b N |
258 | (atomic_read(&conf->active_stripes) |
259 | < (conf->max_nr_stripes *3/4) | |
1da177e4 LT |
260 | || !conf->inactive_blocked), |
261 | conf->device_lock, | |
262 | unplug_slaves(conf->mddev); | |
263 | ); | |
264 | conf->inactive_blocked = 0; | |
265 | } else | |
266 | init_stripe(sh, sector, pd_idx); | |
267 | } else { | |
268 | if (atomic_read(&sh->count)) { | |
269 | if (!list_empty(&sh->lru)) | |
270 | BUG(); | |
271 | } else { | |
272 | if (!test_bit(STRIPE_HANDLE, &sh->state)) | |
273 | atomic_inc(&conf->active_stripes); | |
274 | if (list_empty(&sh->lru)) | |
275 | BUG(); | |
276 | list_del_init(&sh->lru); | |
277 | } | |
278 | } | |
279 | } while (sh == NULL); | |
280 | ||
281 | if (sh) | |
282 | atomic_inc(&sh->count); | |
283 | ||
284 | spin_unlock_irq(&conf->device_lock); | |
285 | return sh; | |
286 | } | |
287 | ||
3f294f4f | 288 | static int grow_one_stripe(raid5_conf_t *conf) |
1da177e4 LT |
289 | { |
290 | struct stripe_head *sh; | |
3f294f4f N |
291 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); |
292 | if (!sh) | |
293 | return 0; | |
294 | memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); | |
295 | sh->raid_conf = conf; | |
296 | spin_lock_init(&sh->lock); | |
297 | ||
298 | if (grow_buffers(sh, conf->raid_disks)) { | |
299 | shrink_buffers(sh, conf->raid_disks); | |
300 | kmem_cache_free(conf->slab_cache, sh); | |
301 | return 0; | |
302 | } | |
303 | /* we just created an active stripe so... */ | |
304 | atomic_set(&sh->count, 1); | |
305 | atomic_inc(&conf->active_stripes); | |
306 | INIT_LIST_HEAD(&sh->lru); | |
307 | release_stripe(sh); | |
308 | return 1; | |
309 | } | |
310 | ||
311 | static int grow_stripes(raid5_conf_t *conf, int num) | |
312 | { | |
1da177e4 LT |
313 | kmem_cache_t *sc; |
314 | int devs = conf->raid_disks; | |
315 | ||
316 | sprintf(conf->cache_name, "raid5/%s", mdname(conf->mddev)); | |
317 | ||
318 | sc = kmem_cache_create(conf->cache_name, | |
319 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), | |
320 | 0, 0, NULL, NULL); | |
321 | if (!sc) | |
322 | return 1; | |
323 | conf->slab_cache = sc; | |
324 | while (num--) { | |
3f294f4f | 325 | if (!grow_one_stripe(conf)) |
1da177e4 | 326 | return 1; |
1da177e4 LT |
327 | } |
328 | return 0; | |
329 | } | |
330 | ||
3f294f4f | 331 | static int drop_one_stripe(raid5_conf_t *conf) |
1da177e4 LT |
332 | { |
333 | struct stripe_head *sh; | |
334 | ||
3f294f4f N |
335 | spin_lock_irq(&conf->device_lock); |
336 | sh = get_free_stripe(conf); | |
337 | spin_unlock_irq(&conf->device_lock); | |
338 | if (!sh) | |
339 | return 0; | |
340 | if (atomic_read(&sh->count)) | |
341 | BUG(); | |
342 | shrink_buffers(sh, conf->raid_disks); | |
343 | kmem_cache_free(conf->slab_cache, sh); | |
344 | atomic_dec(&conf->active_stripes); | |
345 | return 1; | |
346 | } | |
347 | ||
348 | static void shrink_stripes(raid5_conf_t *conf) | |
349 | { | |
350 | while (drop_one_stripe(conf)) | |
351 | ; | |
352 | ||
29fc7e3e N |
353 | if (conf->slab_cache) |
354 | kmem_cache_destroy(conf->slab_cache); | |
1da177e4 LT |
355 | conf->slab_cache = NULL; |
356 | } | |
357 | ||
4e5314b5 | 358 | static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, |
1da177e4 LT |
359 | int error) |
360 | { | |
361 | struct stripe_head *sh = bi->bi_private; | |
362 | raid5_conf_t *conf = sh->raid_conf; | |
363 | int disks = conf->raid_disks, i; | |
364 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
365 | ||
366 | if (bi->bi_size) | |
367 | return 1; | |
368 | ||
369 | for (i=0 ; i<disks; i++) | |
370 | if (bi == &sh->dev[i].req) | |
371 | break; | |
372 | ||
373 | PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", | |
374 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
375 | uptodate); | |
376 | if (i == disks) { | |
377 | BUG(); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | if (uptodate) { | |
382 | #if 0 | |
383 | struct bio *bio; | |
384 | unsigned long flags; | |
385 | spin_lock_irqsave(&conf->device_lock, flags); | |
386 | /* we can return a buffer if we bypassed the cache or | |
387 | * if the top buffer is not in highmem. If there are | |
388 | * multiple buffers, leave the extra work to | |
389 | * handle_stripe | |
390 | */ | |
391 | buffer = sh->bh_read[i]; | |
392 | if (buffer && | |
393 | (!PageHighMem(buffer->b_page) | |
394 | || buffer->b_page == bh->b_page ) | |
395 | ) { | |
396 | sh->bh_read[i] = buffer->b_reqnext; | |
397 | buffer->b_reqnext = NULL; | |
398 | } else | |
399 | buffer = NULL; | |
400 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
401 | if (sh->bh_page[i]==bh->b_page) | |
402 | set_buffer_uptodate(bh); | |
403 | if (buffer) { | |
404 | if (buffer->b_page != bh->b_page) | |
405 | memcpy(buffer->b_data, bh->b_data, bh->b_size); | |
406 | buffer->b_end_io(buffer, 1); | |
407 | } | |
408 | #else | |
409 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
4e5314b5 N |
410 | #endif |
411 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
14f8d26b | 412 | printk(KERN_INFO "raid5: read error corrected!!\n"); |
4e5314b5 N |
413 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
414 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
415 | } | |
ba22dcbf N |
416 | if (atomic_read(&conf->disks[i].rdev->read_errors)) |
417 | atomic_set(&conf->disks[i].rdev->read_errors, 0); | |
1da177e4 | 418 | } else { |
ba22dcbf | 419 | int retry = 0; |
1da177e4 | 420 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
ba22dcbf N |
421 | atomic_inc(&conf->disks[i].rdev->read_errors); |
422 | if (conf->mddev->degraded) | |
14f8d26b | 423 | printk(KERN_WARNING "raid5: read error not correctable.\n"); |
ba22dcbf | 424 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) |
4e5314b5 | 425 | /* Oh, no!!! */ |
14f8d26b | 426 | printk(KERN_WARNING "raid5: read error NOT corrected!!\n"); |
ba22dcbf N |
427 | else if (atomic_read(&conf->disks[i].rdev->read_errors) |
428 | > conf->max_nr_stripes) | |
14f8d26b N |
429 | printk(KERN_WARNING |
430 | "raid5: Too many read errors, failing device.\n"); | |
ba22dcbf N |
431 | else |
432 | retry = 1; | |
433 | if (retry) | |
434 | set_bit(R5_ReadError, &sh->dev[i].flags); | |
435 | else { | |
4e5314b5 N |
436 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
437 | clear_bit(R5_ReWrite, &sh->dev[i].flags); | |
438 | md_error(conf->mddev, conf->disks[i].rdev); | |
ba22dcbf | 439 | } |
1da177e4 LT |
440 | } |
441 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
442 | #if 0 | |
443 | /* must restore b_page before unlocking buffer... */ | |
444 | if (sh->bh_page[i] != bh->b_page) { | |
445 | bh->b_page = sh->bh_page[i]; | |
446 | bh->b_data = page_address(bh->b_page); | |
447 | clear_buffer_uptodate(bh); | |
448 | } | |
449 | #endif | |
450 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
451 | set_bit(STRIPE_HANDLE, &sh->state); | |
452 | release_stripe(sh); | |
453 | return 0; | |
454 | } | |
455 | ||
456 | static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, | |
457 | int error) | |
458 | { | |
459 | struct stripe_head *sh = bi->bi_private; | |
460 | raid5_conf_t *conf = sh->raid_conf; | |
461 | int disks = conf->raid_disks, i; | |
462 | unsigned long flags; | |
463 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); | |
464 | ||
465 | if (bi->bi_size) | |
466 | return 1; | |
467 | ||
468 | for (i=0 ; i<disks; i++) | |
469 | if (bi == &sh->dev[i].req) | |
470 | break; | |
471 | ||
472 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", | |
473 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), | |
474 | uptodate); | |
475 | if (i == disks) { | |
476 | BUG(); | |
477 | return 0; | |
478 | } | |
479 | ||
480 | spin_lock_irqsave(&conf->device_lock, flags); | |
481 | if (!uptodate) | |
482 | md_error(conf->mddev, conf->disks[i].rdev); | |
483 | ||
484 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); | |
485 | ||
486 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
487 | set_bit(STRIPE_HANDLE, &sh->state); | |
488 | __release_stripe(conf, sh); | |
489 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
490 | return 0; | |
491 | } | |
492 | ||
493 | ||
494 | static sector_t compute_blocknr(struct stripe_head *sh, int i); | |
495 | ||
496 | static void raid5_build_block (struct stripe_head *sh, int i) | |
497 | { | |
498 | struct r5dev *dev = &sh->dev[i]; | |
499 | ||
500 | bio_init(&dev->req); | |
501 | dev->req.bi_io_vec = &dev->vec; | |
502 | dev->req.bi_vcnt++; | |
503 | dev->req.bi_max_vecs++; | |
504 | dev->vec.bv_page = dev->page; | |
505 | dev->vec.bv_len = STRIPE_SIZE; | |
506 | dev->vec.bv_offset = 0; | |
507 | ||
508 | dev->req.bi_sector = sh->sector; | |
509 | dev->req.bi_private = sh; | |
510 | ||
511 | dev->flags = 0; | |
512 | if (i != sh->pd_idx) | |
513 | dev->sector = compute_blocknr(sh, i); | |
514 | } | |
515 | ||
516 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
517 | { | |
518 | char b[BDEVNAME_SIZE]; | |
519 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
520 | PRINTK("raid5: error called\n"); | |
521 | ||
b2d444d7 | 522 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 523 | mddev->sb_dirty = 1; |
b2d444d7 | 524 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
525 | conf->working_disks--; |
526 | mddev->degraded++; | |
527 | conf->failed_disks++; | |
b2d444d7 | 528 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
529 | /* |
530 | * if recovery was running, make sure it aborts. | |
531 | */ | |
532 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
533 | } | |
b2d444d7 | 534 | set_bit(Faulty, &rdev->flags); |
1da177e4 LT |
535 | printk (KERN_ALERT |
536 | "raid5: Disk failure on %s, disabling device." | |
537 | " Operation continuing on %d devices\n", | |
538 | bdevname(rdev->bdev,b), conf->working_disks); | |
539 | } | |
540 | } | |
541 | ||
542 | /* | |
543 | * Input: a 'big' sector number, | |
544 | * Output: index of the data and parity disk, and the sector # in them. | |
545 | */ | |
546 | static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, | |
547 | unsigned int data_disks, unsigned int * dd_idx, | |
548 | unsigned int * pd_idx, raid5_conf_t *conf) | |
549 | { | |
550 | long stripe; | |
551 | unsigned long chunk_number; | |
552 | unsigned int chunk_offset; | |
553 | sector_t new_sector; | |
554 | int sectors_per_chunk = conf->chunk_size >> 9; | |
555 | ||
556 | /* First compute the information on this sector */ | |
557 | ||
558 | /* | |
559 | * Compute the chunk number and the sector offset inside the chunk | |
560 | */ | |
561 | chunk_offset = sector_div(r_sector, sectors_per_chunk); | |
562 | chunk_number = r_sector; | |
563 | BUG_ON(r_sector != chunk_number); | |
564 | ||
565 | /* | |
566 | * Compute the stripe number | |
567 | */ | |
568 | stripe = chunk_number / data_disks; | |
569 | ||
570 | /* | |
571 | * Compute the data disk and parity disk indexes inside the stripe | |
572 | */ | |
573 | *dd_idx = chunk_number % data_disks; | |
574 | ||
575 | /* | |
576 | * Select the parity disk based on the user selected algorithm. | |
577 | */ | |
578 | if (conf->level == 4) | |
579 | *pd_idx = data_disks; | |
580 | else switch (conf->algorithm) { | |
581 | case ALGORITHM_LEFT_ASYMMETRIC: | |
582 | *pd_idx = data_disks - stripe % raid_disks; | |
583 | if (*dd_idx >= *pd_idx) | |
584 | (*dd_idx)++; | |
585 | break; | |
586 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
587 | *pd_idx = stripe % raid_disks; | |
588 | if (*dd_idx >= *pd_idx) | |
589 | (*dd_idx)++; | |
590 | break; | |
591 | case ALGORITHM_LEFT_SYMMETRIC: | |
592 | *pd_idx = data_disks - stripe % raid_disks; | |
593 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
594 | break; | |
595 | case ALGORITHM_RIGHT_SYMMETRIC: | |
596 | *pd_idx = stripe % raid_disks; | |
597 | *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; | |
598 | break; | |
599 | default: | |
14f8d26b | 600 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1da177e4 LT |
601 | conf->algorithm); |
602 | } | |
603 | ||
604 | /* | |
605 | * Finally, compute the new sector number | |
606 | */ | |
607 | new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; | |
608 | return new_sector; | |
609 | } | |
610 | ||
611 | ||
612 | static sector_t compute_blocknr(struct stripe_head *sh, int i) | |
613 | { | |
614 | raid5_conf_t *conf = sh->raid_conf; | |
615 | int raid_disks = conf->raid_disks, data_disks = raid_disks - 1; | |
616 | sector_t new_sector = sh->sector, check; | |
617 | int sectors_per_chunk = conf->chunk_size >> 9; | |
618 | sector_t stripe; | |
619 | int chunk_offset; | |
620 | int chunk_number, dummy1, dummy2, dd_idx = i; | |
621 | sector_t r_sector; | |
622 | ||
623 | chunk_offset = sector_div(new_sector, sectors_per_chunk); | |
624 | stripe = new_sector; | |
625 | BUG_ON(new_sector != stripe); | |
626 | ||
627 | ||
628 | switch (conf->algorithm) { | |
629 | case ALGORITHM_LEFT_ASYMMETRIC: | |
630 | case ALGORITHM_RIGHT_ASYMMETRIC: | |
631 | if (i > sh->pd_idx) | |
632 | i--; | |
633 | break; | |
634 | case ALGORITHM_LEFT_SYMMETRIC: | |
635 | case ALGORITHM_RIGHT_SYMMETRIC: | |
636 | if (i < sh->pd_idx) | |
637 | i += raid_disks; | |
638 | i -= (sh->pd_idx + 1); | |
639 | break; | |
640 | default: | |
14f8d26b | 641 | printk(KERN_ERR "raid5: unsupported algorithm %d\n", |
1da177e4 LT |
642 | conf->algorithm); |
643 | } | |
644 | ||
645 | chunk_number = stripe * data_disks + i; | |
646 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; | |
647 | ||
648 | check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); | |
649 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { | |
14f8d26b | 650 | printk(KERN_ERR "compute_blocknr: map not correct\n"); |
1da177e4 LT |
651 | return 0; |
652 | } | |
653 | return r_sector; | |
654 | } | |
655 | ||
656 | ||
657 | ||
658 | /* | |
659 | * Copy data between a page in the stripe cache, and a bio. | |
660 | * There are no alignment or size guarantees between the page or the | |
661 | * bio except that there is some overlap. | |
662 | * All iovecs in the bio must be considered. | |
663 | */ | |
664 | static void copy_data(int frombio, struct bio *bio, | |
665 | struct page *page, | |
666 | sector_t sector) | |
667 | { | |
668 | char *pa = page_address(page); | |
669 | struct bio_vec *bvl; | |
670 | int i; | |
671 | int page_offset; | |
672 | ||
673 | if (bio->bi_sector >= sector) | |
674 | page_offset = (signed)(bio->bi_sector - sector) * 512; | |
675 | else | |
676 | page_offset = (signed)(sector - bio->bi_sector) * -512; | |
677 | bio_for_each_segment(bvl, bio, i) { | |
678 | int len = bio_iovec_idx(bio,i)->bv_len; | |
679 | int clen; | |
680 | int b_offset = 0; | |
681 | ||
682 | if (page_offset < 0) { | |
683 | b_offset = -page_offset; | |
684 | page_offset += b_offset; | |
685 | len -= b_offset; | |
686 | } | |
687 | ||
688 | if (len > 0 && page_offset + len > STRIPE_SIZE) | |
689 | clen = STRIPE_SIZE - page_offset; | |
690 | else clen = len; | |
691 | ||
692 | if (clen > 0) { | |
693 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); | |
694 | if (frombio) | |
695 | memcpy(pa+page_offset, ba+b_offset, clen); | |
696 | else | |
697 | memcpy(ba+b_offset, pa+page_offset, clen); | |
698 | __bio_kunmap_atomic(ba, KM_USER0); | |
699 | } | |
700 | if (clen < len) /* hit end of page */ | |
701 | break; | |
702 | page_offset += len; | |
703 | } | |
704 | } | |
705 | ||
706 | #define check_xor() do { \ | |
707 | if (count == MAX_XOR_BLOCKS) { \ | |
708 | xor_block(count, STRIPE_SIZE, ptr); \ | |
709 | count = 1; \ | |
710 | } \ | |
711 | } while(0) | |
712 | ||
713 | ||
714 | static void compute_block(struct stripe_head *sh, int dd_idx) | |
715 | { | |
716 | raid5_conf_t *conf = sh->raid_conf; | |
717 | int i, count, disks = conf->raid_disks; | |
718 | void *ptr[MAX_XOR_BLOCKS], *p; | |
719 | ||
720 | PRINTK("compute_block, stripe %llu, idx %d\n", | |
721 | (unsigned long long)sh->sector, dd_idx); | |
722 | ||
723 | ptr[0] = page_address(sh->dev[dd_idx].page); | |
724 | memset(ptr[0], 0, STRIPE_SIZE); | |
725 | count = 1; | |
726 | for (i = disks ; i--; ) { | |
727 | if (i == dd_idx) | |
728 | continue; | |
729 | p = page_address(sh->dev[i].page); | |
730 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) | |
731 | ptr[count++] = p; | |
732 | else | |
14f8d26b | 733 | printk(KERN_ERR "compute_block() %d, stripe %llu, %d" |
1da177e4 LT |
734 | " not present\n", dd_idx, |
735 | (unsigned long long)sh->sector, i); | |
736 | ||
737 | check_xor(); | |
738 | } | |
739 | if (count != 1) | |
740 | xor_block(count, STRIPE_SIZE, ptr); | |
741 | set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); | |
742 | } | |
743 | ||
744 | static void compute_parity(struct stripe_head *sh, int method) | |
745 | { | |
746 | raid5_conf_t *conf = sh->raid_conf; | |
747 | int i, pd_idx = sh->pd_idx, disks = conf->raid_disks, count; | |
748 | void *ptr[MAX_XOR_BLOCKS]; | |
749 | struct bio *chosen; | |
750 | ||
751 | PRINTK("compute_parity, stripe %llu, method %d\n", | |
752 | (unsigned long long)sh->sector, method); | |
753 | ||
754 | count = 1; | |
755 | ptr[0] = page_address(sh->dev[pd_idx].page); | |
756 | switch(method) { | |
757 | case READ_MODIFY_WRITE: | |
758 | if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags)) | |
759 | BUG(); | |
760 | for (i=disks ; i-- ;) { | |
761 | if (i==pd_idx) | |
762 | continue; | |
763 | if (sh->dev[i].towrite && | |
764 | test_bit(R5_UPTODATE, &sh->dev[i].flags)) { | |
765 | ptr[count++] = page_address(sh->dev[i].page); | |
766 | chosen = sh->dev[i].towrite; | |
767 | sh->dev[i].towrite = NULL; | |
768 | ||
769 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
770 | wake_up(&conf->wait_for_overlap); | |
771 | ||
772 | if (sh->dev[i].written) BUG(); | |
773 | sh->dev[i].written = chosen; | |
774 | check_xor(); | |
775 | } | |
776 | } | |
777 | break; | |
778 | case RECONSTRUCT_WRITE: | |
779 | memset(ptr[0], 0, STRIPE_SIZE); | |
780 | for (i= disks; i-- ;) | |
781 | if (i!=pd_idx && sh->dev[i].towrite) { | |
782 | chosen = sh->dev[i].towrite; | |
783 | sh->dev[i].towrite = NULL; | |
784 | ||
785 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
786 | wake_up(&conf->wait_for_overlap); | |
787 | ||
788 | if (sh->dev[i].written) BUG(); | |
789 | sh->dev[i].written = chosen; | |
790 | } | |
791 | break; | |
792 | case CHECK_PARITY: | |
793 | break; | |
794 | } | |
795 | if (count>1) { | |
796 | xor_block(count, STRIPE_SIZE, ptr); | |
797 | count = 1; | |
798 | } | |
799 | ||
800 | for (i = disks; i--;) | |
801 | if (sh->dev[i].written) { | |
802 | sector_t sector = sh->dev[i].sector; | |
803 | struct bio *wbi = sh->dev[i].written; | |
804 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { | |
805 | copy_data(1, wbi, sh->dev[i].page, sector); | |
806 | wbi = r5_next_bio(wbi, sector); | |
807 | } | |
808 | ||
809 | set_bit(R5_LOCKED, &sh->dev[i].flags); | |
810 | set_bit(R5_UPTODATE, &sh->dev[i].flags); | |
811 | } | |
812 | ||
813 | switch(method) { | |
814 | case RECONSTRUCT_WRITE: | |
815 | case CHECK_PARITY: | |
816 | for (i=disks; i--;) | |
817 | if (i != pd_idx) { | |
818 | ptr[count++] = page_address(sh->dev[i].page); | |
819 | check_xor(); | |
820 | } | |
821 | break; | |
822 | case READ_MODIFY_WRITE: | |
823 | for (i = disks; i--;) | |
824 | if (sh->dev[i].written) { | |
825 | ptr[count++] = page_address(sh->dev[i].page); | |
826 | check_xor(); | |
827 | } | |
828 | } | |
829 | if (count != 1) | |
830 | xor_block(count, STRIPE_SIZE, ptr); | |
831 | ||
832 | if (method != CHECK_PARITY) { | |
833 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
834 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); | |
835 | } else | |
836 | clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); | |
837 | } | |
838 | ||
839 | /* | |
840 | * Each stripe/dev can have one or more bion attached. | |
841 | * toread/towrite point to the first in a chain. | |
842 | * The bi_next chain must be in order. | |
843 | */ | |
844 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) | |
845 | { | |
846 | struct bio **bip; | |
847 | raid5_conf_t *conf = sh->raid_conf; | |
72626685 | 848 | int firstwrite=0; |
1da177e4 LT |
849 | |
850 | PRINTK("adding bh b#%llu to stripe s#%llu\n", | |
851 | (unsigned long long)bi->bi_sector, | |
852 | (unsigned long long)sh->sector); | |
853 | ||
854 | ||
855 | spin_lock(&sh->lock); | |
856 | spin_lock_irq(&conf->device_lock); | |
72626685 | 857 | if (forwrite) { |
1da177e4 | 858 | bip = &sh->dev[dd_idx].towrite; |
72626685 N |
859 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
860 | firstwrite = 1; | |
861 | } else | |
1da177e4 LT |
862 | bip = &sh->dev[dd_idx].toread; |
863 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { | |
864 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) | |
865 | goto overlap; | |
866 | bip = & (*bip)->bi_next; | |
867 | } | |
868 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) | |
869 | goto overlap; | |
870 | ||
871 | if (*bip && bi->bi_next && (*bip) != bi->bi_next) | |
872 | BUG(); | |
873 | if (*bip) | |
874 | bi->bi_next = *bip; | |
875 | *bip = bi; | |
876 | bi->bi_phys_segments ++; | |
877 | spin_unlock_irq(&conf->device_lock); | |
878 | spin_unlock(&sh->lock); | |
879 | ||
880 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", | |
881 | (unsigned long long)bi->bi_sector, | |
882 | (unsigned long long)sh->sector, dd_idx); | |
883 | ||
72626685 N |
884 | if (conf->mddev->bitmap && firstwrite) { |
885 | sh->bm_seq = conf->seq_write; | |
886 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, | |
887 | STRIPE_SECTORS, 0); | |
888 | set_bit(STRIPE_BIT_DELAY, &sh->state); | |
889 | } | |
890 | ||
1da177e4 LT |
891 | if (forwrite) { |
892 | /* check if page is covered */ | |
893 | sector_t sector = sh->dev[dd_idx].sector; | |
894 | for (bi=sh->dev[dd_idx].towrite; | |
895 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && | |
896 | bi && bi->bi_sector <= sector; | |
897 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { | |
898 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) | |
899 | sector = bi->bi_sector + (bi->bi_size>>9); | |
900 | } | |
901 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) | |
902 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); | |
903 | } | |
904 | return 1; | |
905 | ||
906 | overlap: | |
907 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); | |
908 | spin_unlock_irq(&conf->device_lock); | |
909 | spin_unlock(&sh->lock); | |
910 | return 0; | |
911 | } | |
912 | ||
913 | ||
914 | /* | |
915 | * handle_stripe - do things to a stripe. | |
916 | * | |
917 | * We lock the stripe and then examine the state of various bits | |
918 | * to see what needs to be done. | |
919 | * Possible results: | |
920 | * return some read request which now have data | |
921 | * return some write requests which are safely on disc | |
922 | * schedule a read on some buffers | |
923 | * schedule a write of some buffers | |
924 | * return confirmation of parity correctness | |
925 | * | |
926 | * Parity calculations are done inside the stripe lock | |
927 | * buffers are taken off read_list or write_list, and bh_cache buffers | |
928 | * get BH_Lock set before the stripe lock is released. | |
929 | * | |
930 | */ | |
931 | ||
932 | static void handle_stripe(struct stripe_head *sh) | |
933 | { | |
934 | raid5_conf_t *conf = sh->raid_conf; | |
935 | int disks = conf->raid_disks; | |
936 | struct bio *return_bi= NULL; | |
937 | struct bio *bi; | |
938 | int i; | |
939 | int syncing; | |
940 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; | |
941 | int non_overwrite = 0; | |
942 | int failed_num=0; | |
943 | struct r5dev *dev; | |
944 | ||
945 | PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n", | |
946 | (unsigned long long)sh->sector, atomic_read(&sh->count), | |
947 | sh->pd_idx); | |
948 | ||
949 | spin_lock(&sh->lock); | |
950 | clear_bit(STRIPE_HANDLE, &sh->state); | |
951 | clear_bit(STRIPE_DELAYED, &sh->state); | |
952 | ||
953 | syncing = test_bit(STRIPE_SYNCING, &sh->state); | |
954 | /* Now to look around and see what can be done */ | |
955 | ||
9910f16a | 956 | rcu_read_lock(); |
1da177e4 LT |
957 | for (i=disks; i--; ) { |
958 | mdk_rdev_t *rdev; | |
959 | dev = &sh->dev[i]; | |
960 | clear_bit(R5_Insync, &dev->flags); | |
1da177e4 LT |
961 | |
962 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", | |
963 | i, dev->flags, dev->toread, dev->towrite, dev->written); | |
964 | /* maybe we can reply to a read */ | |
965 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { | |
966 | struct bio *rbi, *rbi2; | |
967 | PRINTK("Return read for disc %d\n", i); | |
968 | spin_lock_irq(&conf->device_lock); | |
969 | rbi = dev->toread; | |
970 | dev->toread = NULL; | |
971 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) | |
972 | wake_up(&conf->wait_for_overlap); | |
973 | spin_unlock_irq(&conf->device_lock); | |
974 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
975 | copy_data(0, rbi, dev->page, dev->sector); | |
976 | rbi2 = r5_next_bio(rbi, dev->sector); | |
977 | spin_lock_irq(&conf->device_lock); | |
978 | if (--rbi->bi_phys_segments == 0) { | |
979 | rbi->bi_next = return_bi; | |
980 | return_bi = rbi; | |
981 | } | |
982 | spin_unlock_irq(&conf->device_lock); | |
983 | rbi = rbi2; | |
984 | } | |
985 | } | |
986 | ||
987 | /* now count some things */ | |
988 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; | |
989 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; | |
990 | ||
991 | ||
992 | if (dev->toread) to_read++; | |
993 | if (dev->towrite) { | |
994 | to_write++; | |
995 | if (!test_bit(R5_OVERWRITE, &dev->flags)) | |
996 | non_overwrite++; | |
997 | } | |
998 | if (dev->written) written++; | |
9910f16a | 999 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1000 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
14f8d26b | 1001 | /* The ReadError flag will just be confusing now */ |
4e5314b5 N |
1002 | clear_bit(R5_ReadError, &dev->flags); |
1003 | clear_bit(R5_ReWrite, &dev->flags); | |
1004 | } | |
b2d444d7 | 1005 | if (!rdev || !test_bit(In_sync, &rdev->flags) |
4e5314b5 | 1006 | || test_bit(R5_ReadError, &dev->flags)) { |
1da177e4 LT |
1007 | failed++; |
1008 | failed_num = i; | |
1009 | } else | |
1010 | set_bit(R5_Insync, &dev->flags); | |
1011 | } | |
9910f16a | 1012 | rcu_read_unlock(); |
1da177e4 LT |
1013 | PRINTK("locked=%d uptodate=%d to_read=%d" |
1014 | " to_write=%d failed=%d failed_num=%d\n", | |
1015 | locked, uptodate, to_read, to_write, failed, failed_num); | |
1016 | /* check if the array has lost two devices and, if so, some requests might | |
1017 | * need to be failed | |
1018 | */ | |
1019 | if (failed > 1 && to_read+to_write+written) { | |
1da177e4 | 1020 | for (i=disks; i--; ) { |
72626685 | 1021 | int bitmap_end = 0; |
4e5314b5 N |
1022 | |
1023 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
9910f16a N |
1024 | mdk_rdev_t *rdev; |
1025 | rcu_read_lock(); | |
1026 | rdev = rcu_dereference(conf->disks[i].rdev); | |
b2d444d7 | 1027 | if (rdev && test_bit(In_sync, &rdev->flags)) |
4e5314b5 N |
1028 | /* multiple read failures in one stripe */ |
1029 | md_error(conf->mddev, rdev); | |
9910f16a | 1030 | rcu_read_unlock(); |
4e5314b5 N |
1031 | } |
1032 | ||
72626685 | 1033 | spin_lock_irq(&conf->device_lock); |
1da177e4 LT |
1034 | /* fail all writes first */ |
1035 | bi = sh->dev[i].towrite; | |
1036 | sh->dev[i].towrite = NULL; | |
72626685 | 1037 | if (bi) { to_write--; bitmap_end = 1; } |
1da177e4 LT |
1038 | |
1039 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1040 | wake_up(&conf->wait_for_overlap); | |
1041 | ||
1042 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1043 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1044 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1045 | if (--bi->bi_phys_segments == 0) { | |
1046 | md_write_end(conf->mddev); | |
1047 | bi->bi_next = return_bi; | |
1048 | return_bi = bi; | |
1049 | } | |
1050 | bi = nextbi; | |
1051 | } | |
1052 | /* and fail all 'written' */ | |
1053 | bi = sh->dev[i].written; | |
1054 | sh->dev[i].written = NULL; | |
72626685 | 1055 | if (bi) bitmap_end = 1; |
1da177e4 LT |
1056 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { |
1057 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); | |
1058 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1059 | if (--bi->bi_phys_segments == 0) { | |
1060 | md_write_end(conf->mddev); | |
1061 | bi->bi_next = return_bi; | |
1062 | return_bi = bi; | |
1063 | } | |
1064 | bi = bi2; | |
1065 | } | |
1066 | ||
1067 | /* fail any reads if this device is non-operational */ | |
4e5314b5 N |
1068 | if (!test_bit(R5_Insync, &sh->dev[i].flags) || |
1069 | test_bit(R5_ReadError, &sh->dev[i].flags)) { | |
1da177e4 LT |
1070 | bi = sh->dev[i].toread; |
1071 | sh->dev[i].toread = NULL; | |
1072 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) | |
1073 | wake_up(&conf->wait_for_overlap); | |
1074 | if (bi) to_read--; | |
1075 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ | |
1076 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); | |
1077 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1078 | if (--bi->bi_phys_segments == 0) { | |
1079 | bi->bi_next = return_bi; | |
1080 | return_bi = bi; | |
1081 | } | |
1082 | bi = nextbi; | |
1083 | } | |
1084 | } | |
72626685 N |
1085 | spin_unlock_irq(&conf->device_lock); |
1086 | if (bitmap_end) | |
1087 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1088 | STRIPE_SECTORS, 0, 0); | |
1da177e4 | 1089 | } |
1da177e4 LT |
1090 | } |
1091 | if (failed > 1 && syncing) { | |
1092 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); | |
1093 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1094 | syncing = 0; | |
1095 | } | |
1096 | ||
1097 | /* might be able to return some write requests if the parity block | |
1098 | * is safe, or on a failed drive | |
1099 | */ | |
1100 | dev = &sh->dev[sh->pd_idx]; | |
1101 | if ( written && | |
1102 | ( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) && | |
1103 | test_bit(R5_UPTODATE, &dev->flags)) | |
1104 | || (failed == 1 && failed_num == sh->pd_idx)) | |
1105 | ) { | |
1106 | /* any written block on an uptodate or failed drive can be returned. | |
1107 | * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but | |
1108 | * never LOCKED, so we don't need to test 'failed' directly. | |
1109 | */ | |
1110 | for (i=disks; i--; ) | |
1111 | if (sh->dev[i].written) { | |
1112 | dev = &sh->dev[i]; | |
1113 | if (!test_bit(R5_LOCKED, &dev->flags) && | |
1114 | test_bit(R5_UPTODATE, &dev->flags) ) { | |
1115 | /* We can return any write requests */ | |
1116 | struct bio *wbi, *wbi2; | |
72626685 | 1117 | int bitmap_end = 0; |
1da177e4 LT |
1118 | PRINTK("Return write for disc %d\n", i); |
1119 | spin_lock_irq(&conf->device_lock); | |
1120 | wbi = dev->written; | |
1121 | dev->written = NULL; | |
1122 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { | |
1123 | wbi2 = r5_next_bio(wbi, dev->sector); | |
1124 | if (--wbi->bi_phys_segments == 0) { | |
1125 | md_write_end(conf->mddev); | |
1126 | wbi->bi_next = return_bi; | |
1127 | return_bi = wbi; | |
1128 | } | |
1129 | wbi = wbi2; | |
1130 | } | |
72626685 N |
1131 | if (dev->towrite == NULL) |
1132 | bitmap_end = 1; | |
1da177e4 | 1133 | spin_unlock_irq(&conf->device_lock); |
72626685 N |
1134 | if (bitmap_end) |
1135 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, | |
1136 | STRIPE_SECTORS, | |
1137 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); | |
1da177e4 LT |
1138 | } |
1139 | } | |
1140 | } | |
1141 | ||
1142 | /* Now we might consider reading some blocks, either to check/generate | |
1143 | * parity, or to satisfy requests | |
1144 | * or to load a block that is being partially written. | |
1145 | */ | |
1146 | if (to_read || non_overwrite || (syncing && (uptodate < disks))) { | |
1147 | for (i=disks; i--;) { | |
1148 | dev = &sh->dev[i]; | |
1149 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1150 | (dev->toread || | |
1151 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || | |
1152 | syncing || | |
1153 | (failed && (sh->dev[failed_num].toread || | |
1154 | (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags)))) | |
1155 | ) | |
1156 | ) { | |
1157 | /* we would like to get this block, possibly | |
1158 | * by computing it, but we might not be able to | |
1159 | */ | |
1160 | if (uptodate == disks-1) { | |
1161 | PRINTK("Computing block %d\n", i); | |
1162 | compute_block(sh, i); | |
1163 | uptodate++; | |
1164 | } else if (test_bit(R5_Insync, &dev->flags)) { | |
1165 | set_bit(R5_LOCKED, &dev->flags); | |
1166 | set_bit(R5_Wantread, &dev->flags); | |
1167 | #if 0 | |
1168 | /* if I am just reading this block and we don't have | |
1169 | a failed drive, or any pending writes then sidestep the cache */ | |
1170 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && | |
1171 | ! syncing && !failed && !to_write) { | |
1172 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; | |
1173 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; | |
1174 | } | |
1175 | #endif | |
1176 | locked++; | |
1177 | PRINTK("Reading block %d (sync=%d)\n", | |
1178 | i, syncing); | |
1da177e4 LT |
1179 | } |
1180 | } | |
1181 | } | |
1182 | set_bit(STRIPE_HANDLE, &sh->state); | |
1183 | } | |
1184 | ||
1185 | /* now to consider writing and what else, if anything should be read */ | |
1186 | if (to_write) { | |
1187 | int rmw=0, rcw=0; | |
1188 | for (i=disks ; i--;) { | |
1189 | /* would I have to read this buffer for read_modify_write */ | |
1190 | dev = &sh->dev[i]; | |
1191 | if ((dev->towrite || i == sh->pd_idx) && | |
1192 | (!test_bit(R5_LOCKED, &dev->flags) | |
1193 | #if 0 | |
1194 | || sh->bh_page[i]!=bh->b_page | |
1195 | #endif | |
1196 | ) && | |
1197 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1198 | if (test_bit(R5_Insync, &dev->flags) | |
1199 | /* && !(!mddev->insync && i == sh->pd_idx) */ | |
1200 | ) | |
1201 | rmw++; | |
1202 | else rmw += 2*disks; /* cannot read it */ | |
1203 | } | |
1204 | /* Would I have to read this buffer for reconstruct_write */ | |
1205 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && | |
1206 | (!test_bit(R5_LOCKED, &dev->flags) | |
1207 | #if 0 | |
1208 | || sh->bh_page[i] != bh->b_page | |
1209 | #endif | |
1210 | ) && | |
1211 | !test_bit(R5_UPTODATE, &dev->flags)) { | |
1212 | if (test_bit(R5_Insync, &dev->flags)) rcw++; | |
1213 | else rcw += 2*disks; | |
1214 | } | |
1215 | } | |
1216 | PRINTK("for sector %llu, rmw=%d rcw=%d\n", | |
1217 | (unsigned long long)sh->sector, rmw, rcw); | |
1218 | set_bit(STRIPE_HANDLE, &sh->state); | |
1219 | if (rmw < rcw && rmw > 0) | |
1220 | /* prefer read-modify-write, but need to get some data */ | |
1221 | for (i=disks; i--;) { | |
1222 | dev = &sh->dev[i]; | |
1223 | if ((dev->towrite || i == sh->pd_idx) && | |
1224 | !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1225 | test_bit(R5_Insync, &dev->flags)) { | |
1226 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1227 | { | |
1228 | PRINTK("Read_old block %d for r-m-w\n", i); | |
1229 | set_bit(R5_LOCKED, &dev->flags); | |
1230 | set_bit(R5_Wantread, &dev->flags); | |
1231 | locked++; | |
1232 | } else { | |
1233 | set_bit(STRIPE_DELAYED, &sh->state); | |
1234 | set_bit(STRIPE_HANDLE, &sh->state); | |
1235 | } | |
1236 | } | |
1237 | } | |
1238 | if (rcw <= rmw && rcw > 0) | |
1239 | /* want reconstruct write, but need to get some data */ | |
1240 | for (i=disks; i--;) { | |
1241 | dev = &sh->dev[i]; | |
1242 | if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && | |
1243 | !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && | |
1244 | test_bit(R5_Insync, &dev->flags)) { | |
1245 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1246 | { | |
1247 | PRINTK("Read_old block %d for Reconstruct\n", i); | |
1248 | set_bit(R5_LOCKED, &dev->flags); | |
1249 | set_bit(R5_Wantread, &dev->flags); | |
1250 | locked++; | |
1251 | } else { | |
1252 | set_bit(STRIPE_DELAYED, &sh->state); | |
1253 | set_bit(STRIPE_HANDLE, &sh->state); | |
1254 | } | |
1255 | } | |
1256 | } | |
1257 | /* now if nothing is locked, and if we have enough data, we can start a write request */ | |
72626685 N |
1258 | if (locked == 0 && (rcw == 0 ||rmw == 0) && |
1259 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { | |
1da177e4 LT |
1260 | PRINTK("Computing parity...\n"); |
1261 | compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); | |
1262 | /* now every locked buffer is ready to be written */ | |
1263 | for (i=disks; i--;) | |
1264 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { | |
1265 | PRINTK("Writing block %d\n", i); | |
1266 | locked++; | |
1267 | set_bit(R5_Wantwrite, &sh->dev[i].flags); | |
1268 | if (!test_bit(R5_Insync, &sh->dev[i].flags) | |
1269 | || (i==sh->pd_idx && failed == 0)) | |
1270 | set_bit(STRIPE_INSYNC, &sh->state); | |
1271 | } | |
1272 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { | |
1273 | atomic_dec(&conf->preread_active_stripes); | |
1274 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) | |
1275 | md_wakeup_thread(conf->mddev->thread); | |
1276 | } | |
1277 | } | |
1278 | } | |
1279 | ||
1280 | /* maybe we need to check and possibly fix the parity for this stripe | |
1281 | * Any reads will already have been scheduled, so we just see if enough data | |
1282 | * is available | |
1283 | */ | |
1284 | if (syncing && locked == 0 && | |
14f8d26b | 1285 | !test_bit(STRIPE_INSYNC, &sh->state)) { |
1da177e4 LT |
1286 | set_bit(STRIPE_HANDLE, &sh->state); |
1287 | if (failed == 0) { | |
1288 | char *pagea; | |
1289 | if (uptodate != disks) | |
1290 | BUG(); | |
1291 | compute_parity(sh, CHECK_PARITY); | |
1292 | uptodate--; | |
1293 | pagea = page_address(sh->dev[sh->pd_idx].page); | |
1294 | if ((*(u32*)pagea) == 0 && | |
1295 | !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) { | |
1296 | /* parity is correct (on disc, not in buffer any more) */ | |
1297 | set_bit(STRIPE_INSYNC, &sh->state); | |
9d88883e N |
1298 | } else { |
1299 | conf->mddev->resync_mismatches += STRIPE_SECTORS; | |
1300 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) | |
1301 | /* don't try to repair!! */ | |
1302 | set_bit(STRIPE_INSYNC, &sh->state); | |
14f8d26b N |
1303 | else { |
1304 | compute_block(sh, sh->pd_idx); | |
1305 | uptodate++; | |
1306 | } | |
1da177e4 LT |
1307 | } |
1308 | } | |
1309 | if (!test_bit(STRIPE_INSYNC, &sh->state)) { | |
14f8d26b | 1310 | /* either failed parity check, or recovery is happening */ |
1da177e4 LT |
1311 | if (failed==0) |
1312 | failed_num = sh->pd_idx; | |
1da177e4 | 1313 | dev = &sh->dev[failed_num]; |
14f8d26b N |
1314 | BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); |
1315 | BUG_ON(uptodate != disks); | |
1316 | ||
1da177e4 LT |
1317 | set_bit(R5_LOCKED, &dev->flags); |
1318 | set_bit(R5_Wantwrite, &dev->flags); | |
72626685 | 1319 | clear_bit(STRIPE_DEGRADED, &sh->state); |
1da177e4 LT |
1320 | locked++; |
1321 | set_bit(STRIPE_INSYNC, &sh->state); | |
1da177e4 LT |
1322 | } |
1323 | } | |
1324 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { | |
1325 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); | |
1326 | clear_bit(STRIPE_SYNCING, &sh->state); | |
1327 | } | |
4e5314b5 N |
1328 | |
1329 | /* If the failed drive is just a ReadError, then we might need to progress | |
1330 | * the repair/check process | |
1331 | */ | |
ba22dcbf N |
1332 | if (failed == 1 && ! conf->mddev->ro && |
1333 | test_bit(R5_ReadError, &sh->dev[failed_num].flags) | |
4e5314b5 N |
1334 | && !test_bit(R5_LOCKED, &sh->dev[failed_num].flags) |
1335 | && test_bit(R5_UPTODATE, &sh->dev[failed_num].flags) | |
1336 | ) { | |
1337 | dev = &sh->dev[failed_num]; | |
1338 | if (!test_bit(R5_ReWrite, &dev->flags)) { | |
1339 | set_bit(R5_Wantwrite, &dev->flags); | |
1340 | set_bit(R5_ReWrite, &dev->flags); | |
1341 | set_bit(R5_LOCKED, &dev->flags); | |
1342 | } else { | |
1343 | /* let's read it back */ | |
1344 | set_bit(R5_Wantread, &dev->flags); | |
1345 | set_bit(R5_LOCKED, &dev->flags); | |
1346 | } | |
1347 | } | |
1348 | ||
1da177e4 LT |
1349 | spin_unlock(&sh->lock); |
1350 | ||
1351 | while ((bi=return_bi)) { | |
1352 | int bytes = bi->bi_size; | |
1353 | ||
1354 | return_bi = bi->bi_next; | |
1355 | bi->bi_next = NULL; | |
1356 | bi->bi_size = 0; | |
1357 | bi->bi_end_io(bi, bytes, 0); | |
1358 | } | |
1359 | for (i=disks; i-- ;) { | |
1360 | int rw; | |
1361 | struct bio *bi; | |
1362 | mdk_rdev_t *rdev; | |
1363 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) | |
1364 | rw = 1; | |
1365 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) | |
1366 | rw = 0; | |
1367 | else | |
1368 | continue; | |
1369 | ||
1370 | bi = &sh->dev[i].req; | |
1371 | ||
1372 | bi->bi_rw = rw; | |
1373 | if (rw) | |
1374 | bi->bi_end_io = raid5_end_write_request; | |
1375 | else | |
1376 | bi->bi_end_io = raid5_end_read_request; | |
1377 | ||
1378 | rcu_read_lock(); | |
d6065f7b | 1379 | rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1380 | if (rdev && test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
1381 | rdev = NULL; |
1382 | if (rdev) | |
1383 | atomic_inc(&rdev->nr_pending); | |
1384 | rcu_read_unlock(); | |
1385 | ||
1386 | if (rdev) { | |
9910f16a | 1387 | if (syncing) |
1da177e4 LT |
1388 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
1389 | ||
1390 | bi->bi_bdev = rdev->bdev; | |
1391 | PRINTK("for %llu schedule op %ld on disc %d\n", | |
1392 | (unsigned long long)sh->sector, bi->bi_rw, i); | |
1393 | atomic_inc(&sh->count); | |
1394 | bi->bi_sector = sh->sector + rdev->data_offset; | |
1395 | bi->bi_flags = 1 << BIO_UPTODATE; | |
1396 | bi->bi_vcnt = 1; | |
1397 | bi->bi_max_vecs = 1; | |
1398 | bi->bi_idx = 0; | |
1399 | bi->bi_io_vec = &sh->dev[i].vec; | |
1400 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; | |
1401 | bi->bi_io_vec[0].bv_offset = 0; | |
1402 | bi->bi_size = STRIPE_SIZE; | |
1403 | bi->bi_next = NULL; | |
4dbcdc75 N |
1404 | if (rw == WRITE && |
1405 | test_bit(R5_ReWrite, &sh->dev[i].flags)) | |
1406 | atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); | |
1da177e4 LT |
1407 | generic_make_request(bi); |
1408 | } else { | |
72626685 N |
1409 | if (rw == 1) |
1410 | set_bit(STRIPE_DEGRADED, &sh->state); | |
1da177e4 LT |
1411 | PRINTK("skip op %ld on disc %d for sector %llu\n", |
1412 | bi->bi_rw, i, (unsigned long long)sh->sector); | |
1413 | clear_bit(R5_LOCKED, &sh->dev[i].flags); | |
1414 | set_bit(STRIPE_HANDLE, &sh->state); | |
1415 | } | |
1416 | } | |
1417 | } | |
1418 | ||
858119e1 | 1419 | static void raid5_activate_delayed(raid5_conf_t *conf) |
1da177e4 LT |
1420 | { |
1421 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { | |
1422 | while (!list_empty(&conf->delayed_list)) { | |
1423 | struct list_head *l = conf->delayed_list.next; | |
1424 | struct stripe_head *sh; | |
1425 | sh = list_entry(l, struct stripe_head, lru); | |
1426 | list_del_init(l); | |
1427 | clear_bit(STRIPE_DELAYED, &sh->state); | |
1428 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) | |
1429 | atomic_inc(&conf->preread_active_stripes); | |
1430 | list_add_tail(&sh->lru, &conf->handle_list); | |
1431 | } | |
1432 | } | |
1433 | } | |
1434 | ||
858119e1 | 1435 | static void activate_bit_delay(raid5_conf_t *conf) |
72626685 N |
1436 | { |
1437 | /* device_lock is held */ | |
1438 | struct list_head head; | |
1439 | list_add(&head, &conf->bitmap_list); | |
1440 | list_del_init(&conf->bitmap_list); | |
1441 | while (!list_empty(&head)) { | |
1442 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); | |
1443 | list_del_init(&sh->lru); | |
1444 | atomic_inc(&sh->count); | |
1445 | __release_stripe(conf, sh); | |
1446 | } | |
1447 | } | |
1448 | ||
1da177e4 LT |
1449 | static void unplug_slaves(mddev_t *mddev) |
1450 | { | |
1451 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1452 | int i; | |
1453 | ||
1454 | rcu_read_lock(); | |
1455 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 1456 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1457 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
1da177e4 LT |
1458 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
1459 | ||
1460 | atomic_inc(&rdev->nr_pending); | |
1461 | rcu_read_unlock(); | |
1462 | ||
1463 | if (r_queue->unplug_fn) | |
1464 | r_queue->unplug_fn(r_queue); | |
1465 | ||
1466 | rdev_dec_pending(rdev, mddev); | |
1467 | rcu_read_lock(); | |
1468 | } | |
1469 | } | |
1470 | rcu_read_unlock(); | |
1471 | } | |
1472 | ||
1473 | static void raid5_unplug_device(request_queue_t *q) | |
1474 | { | |
1475 | mddev_t *mddev = q->queuedata; | |
1476 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1477 | unsigned long flags; | |
1478 | ||
1479 | spin_lock_irqsave(&conf->device_lock, flags); | |
1480 | ||
72626685 N |
1481 | if (blk_remove_plug(q)) { |
1482 | conf->seq_flush++; | |
1da177e4 | 1483 | raid5_activate_delayed(conf); |
72626685 | 1484 | } |
1da177e4 LT |
1485 | md_wakeup_thread(mddev->thread); |
1486 | ||
1487 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1488 | ||
1489 | unplug_slaves(mddev); | |
1490 | } | |
1491 | ||
1492 | static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk, | |
1493 | sector_t *error_sector) | |
1494 | { | |
1495 | mddev_t *mddev = q->queuedata; | |
1496 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1497 | int i, ret = 0; | |
1498 | ||
1499 | rcu_read_lock(); | |
1500 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 1501 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
b2d444d7 | 1502 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
1503 | struct block_device *bdev = rdev->bdev; |
1504 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
1505 | ||
1506 | if (!r_queue->issue_flush_fn) | |
1507 | ret = -EOPNOTSUPP; | |
1508 | else { | |
1509 | atomic_inc(&rdev->nr_pending); | |
1510 | rcu_read_unlock(); | |
1511 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
1512 | error_sector); | |
1513 | rdev_dec_pending(rdev, mddev); | |
1514 | rcu_read_lock(); | |
1515 | } | |
1516 | } | |
1517 | } | |
1518 | rcu_read_unlock(); | |
1519 | return ret; | |
1520 | } | |
1521 | ||
1522 | static inline void raid5_plug_device(raid5_conf_t *conf) | |
1523 | { | |
1524 | spin_lock_irq(&conf->device_lock); | |
1525 | blk_plug_device(conf->mddev->queue); | |
1526 | spin_unlock_irq(&conf->device_lock); | |
1527 | } | |
1528 | ||
1529 | static int make_request (request_queue_t *q, struct bio * bi) | |
1530 | { | |
1531 | mddev_t *mddev = q->queuedata; | |
1532 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1533 | const unsigned int raid_disks = conf->raid_disks; | |
1534 | const unsigned int data_disks = raid_disks - 1; | |
1535 | unsigned int dd_idx, pd_idx; | |
1536 | sector_t new_sector; | |
1537 | sector_t logical_sector, last_sector; | |
1538 | struct stripe_head *sh; | |
a362357b | 1539 | const int rw = bio_data_dir(bi); |
1da177e4 | 1540 | |
e5dcdd80 N |
1541 | if (unlikely(bio_barrier(bi))) { |
1542 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); | |
1543 | return 0; | |
1544 | } | |
1545 | ||
3d310eb7 | 1546 | md_write_start(mddev, bi); |
06d91a5f | 1547 | |
a362357b JA |
1548 | disk_stat_inc(mddev->gendisk, ios[rw]); |
1549 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); | |
1da177e4 LT |
1550 | |
1551 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); | |
1552 | last_sector = bi->bi_sector + (bi->bi_size>>9); | |
1553 | bi->bi_next = NULL; | |
1554 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ | |
06d91a5f | 1555 | |
1da177e4 LT |
1556 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
1557 | DEFINE_WAIT(w); | |
1558 | ||
1559 | new_sector = raid5_compute_sector(logical_sector, | |
1560 | raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1561 | ||
1562 | PRINTK("raid5: make_request, sector %llu logical %llu\n", | |
1563 | (unsigned long long)new_sector, | |
1564 | (unsigned long long)logical_sector); | |
1565 | ||
1566 | retry: | |
1567 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); | |
1568 | sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); | |
1569 | if (sh) { | |
1570 | if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { | |
1571 | /* Add failed due to overlap. Flush everything | |
1572 | * and wait a while | |
1573 | */ | |
1574 | raid5_unplug_device(mddev->queue); | |
1575 | release_stripe(sh); | |
1576 | schedule(); | |
1577 | goto retry; | |
1578 | } | |
1579 | finish_wait(&conf->wait_for_overlap, &w); | |
1580 | raid5_plug_device(conf); | |
1581 | handle_stripe(sh); | |
1582 | release_stripe(sh); | |
1583 | ||
1584 | } else { | |
1585 | /* cannot get stripe for read-ahead, just give-up */ | |
1586 | clear_bit(BIO_UPTODATE, &bi->bi_flags); | |
1587 | finish_wait(&conf->wait_for_overlap, &w); | |
1588 | break; | |
1589 | } | |
1590 | ||
1591 | } | |
1592 | spin_lock_irq(&conf->device_lock); | |
1593 | if (--bi->bi_phys_segments == 0) { | |
1594 | int bytes = bi->bi_size; | |
1595 | ||
1596 | if ( bio_data_dir(bi) == WRITE ) | |
1597 | md_write_end(mddev); | |
1598 | bi->bi_size = 0; | |
1599 | bi->bi_end_io(bi, bytes, 0); | |
1600 | } | |
1601 | spin_unlock_irq(&conf->device_lock); | |
1602 | return 0; | |
1603 | } | |
1604 | ||
1605 | /* FIXME go_faster isn't used */ | |
57afd89f | 1606 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1607 | { |
1608 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
1609 | struct stripe_head *sh; | |
1610 | int sectors_per_chunk = conf->chunk_size >> 9; | |
1611 | sector_t x; | |
1612 | unsigned long stripe; | |
1613 | int chunk_offset; | |
1614 | int dd_idx, pd_idx; | |
1615 | sector_t first_sector; | |
1616 | int raid_disks = conf->raid_disks; | |
1617 | int data_disks = raid_disks-1; | |
72626685 N |
1618 | sector_t max_sector = mddev->size << 1; |
1619 | int sync_blocks; | |
1da177e4 | 1620 | |
72626685 | 1621 | if (sector_nr >= max_sector) { |
1da177e4 LT |
1622 | /* just being told to finish up .. nothing much to do */ |
1623 | unplug_slaves(mddev); | |
72626685 N |
1624 | |
1625 | if (mddev->curr_resync < max_sector) /* aborted */ | |
1626 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1627 | &sync_blocks, 1); | |
1628 | else /* compelted sync */ | |
1629 | conf->fullsync = 0; | |
1630 | bitmap_close_sync(mddev->bitmap); | |
1631 | ||
1da177e4 LT |
1632 | return 0; |
1633 | } | |
1634 | /* if there is 1 or more failed drives and we are trying | |
1635 | * to resync, then assert that we are finished, because there is | |
1636 | * nothing we can do. | |
1637 | */ | |
1638 | if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
57afd89f N |
1639 | sector_t rv = (mddev->size << 1) - sector_nr; |
1640 | *skipped = 1; | |
1da177e4 LT |
1641 | return rv; |
1642 | } | |
72626685 | 1643 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
3855ad9f | 1644 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
72626685 N |
1645 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { |
1646 | /* we can skip this block, and probably more */ | |
1647 | sync_blocks /= STRIPE_SECTORS; | |
1648 | *skipped = 1; | |
1649 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ | |
1650 | } | |
1da177e4 LT |
1651 | |
1652 | x = sector_nr; | |
1653 | chunk_offset = sector_div(x, sectors_per_chunk); | |
1654 | stripe = x; | |
1655 | BUG_ON(x != stripe); | |
1656 | ||
1657 | first_sector = raid5_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk | |
1658 | + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); | |
1659 | sh = get_active_stripe(conf, sector_nr, pd_idx, 1); | |
1660 | if (sh == NULL) { | |
1661 | sh = get_active_stripe(conf, sector_nr, pd_idx, 0); | |
1662 | /* make sure we don't swamp the stripe cache if someone else | |
1663 | * is trying to get access | |
1664 | */ | |
66c006a5 | 1665 | schedule_timeout_uninterruptible(1); |
1da177e4 | 1666 | } |
72626685 | 1667 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0); |
1da177e4 LT |
1668 | spin_lock(&sh->lock); |
1669 | set_bit(STRIPE_SYNCING, &sh->state); | |
1670 | clear_bit(STRIPE_INSYNC, &sh->state); | |
1671 | spin_unlock(&sh->lock); | |
1672 | ||
1673 | handle_stripe(sh); | |
1674 | release_stripe(sh); | |
1675 | ||
1676 | return STRIPE_SECTORS; | |
1677 | } | |
1678 | ||
1679 | /* | |
1680 | * This is our raid5 kernel thread. | |
1681 | * | |
1682 | * We scan the hash table for stripes which can be handled now. | |
1683 | * During the scan, completed stripes are saved for us by the interrupt | |
1684 | * handler, so that they will not have to wait for our next wakeup. | |
1685 | */ | |
1686 | static void raid5d (mddev_t *mddev) | |
1687 | { | |
1688 | struct stripe_head *sh; | |
1689 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
1690 | int handled; | |
1691 | ||
1692 | PRINTK("+++ raid5d active\n"); | |
1693 | ||
1694 | md_check_recovery(mddev); | |
1da177e4 LT |
1695 | |
1696 | handled = 0; | |
1697 | spin_lock_irq(&conf->device_lock); | |
1698 | while (1) { | |
1699 | struct list_head *first; | |
1700 | ||
72626685 N |
1701 | if (conf->seq_flush - conf->seq_write > 0) { |
1702 | int seq = conf->seq_flush; | |
700e432d | 1703 | spin_unlock_irq(&conf->device_lock); |
72626685 | 1704 | bitmap_unplug(mddev->bitmap); |
700e432d | 1705 | spin_lock_irq(&conf->device_lock); |
72626685 N |
1706 | conf->seq_write = seq; |
1707 | activate_bit_delay(conf); | |
1708 | } | |
1709 | ||
1da177e4 LT |
1710 | if (list_empty(&conf->handle_list) && |
1711 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && | |
1712 | !blk_queue_plugged(mddev->queue) && | |
1713 | !list_empty(&conf->delayed_list)) | |
1714 | raid5_activate_delayed(conf); | |
1715 | ||
1716 | if (list_empty(&conf->handle_list)) | |
1717 | break; | |
1718 | ||
1719 | first = conf->handle_list.next; | |
1720 | sh = list_entry(first, struct stripe_head, lru); | |
1721 | ||
1722 | list_del_init(first); | |
1723 | atomic_inc(&sh->count); | |
1724 | if (atomic_read(&sh->count)!= 1) | |
1725 | BUG(); | |
1726 | spin_unlock_irq(&conf->device_lock); | |
1727 | ||
1728 | handled++; | |
1729 | handle_stripe(sh); | |
1730 | release_stripe(sh); | |
1731 | ||
1732 | spin_lock_irq(&conf->device_lock); | |
1733 | } | |
1734 | PRINTK("%d stripes handled\n", handled); | |
1735 | ||
1736 | spin_unlock_irq(&conf->device_lock); | |
1737 | ||
1738 | unplug_slaves(mddev); | |
1739 | ||
1740 | PRINTK("--- raid5d inactive\n"); | |
1741 | } | |
1742 | ||
3f294f4f | 1743 | static ssize_t |
007583c9 | 1744 | raid5_show_stripe_cache_size(mddev_t *mddev, char *page) |
3f294f4f | 1745 | { |
007583c9 | 1746 | raid5_conf_t *conf = mddev_to_conf(mddev); |
96de1e66 N |
1747 | if (conf) |
1748 | return sprintf(page, "%d\n", conf->max_nr_stripes); | |
1749 | else | |
1750 | return 0; | |
3f294f4f N |
1751 | } |
1752 | ||
1753 | static ssize_t | |
007583c9 | 1754 | raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) |
3f294f4f | 1755 | { |
007583c9 | 1756 | raid5_conf_t *conf = mddev_to_conf(mddev); |
3f294f4f N |
1757 | char *end; |
1758 | int new; | |
1759 | if (len >= PAGE_SIZE) | |
1760 | return -EINVAL; | |
96de1e66 N |
1761 | if (!conf) |
1762 | return -ENODEV; | |
3f294f4f N |
1763 | |
1764 | new = simple_strtoul(page, &end, 10); | |
1765 | if (!*page || (*end && *end != '\n') ) | |
1766 | return -EINVAL; | |
1767 | if (new <= 16 || new > 32768) | |
1768 | return -EINVAL; | |
1769 | while (new < conf->max_nr_stripes) { | |
1770 | if (drop_one_stripe(conf)) | |
1771 | conf->max_nr_stripes--; | |
1772 | else | |
1773 | break; | |
1774 | } | |
1775 | while (new > conf->max_nr_stripes) { | |
1776 | if (grow_one_stripe(conf)) | |
1777 | conf->max_nr_stripes++; | |
1778 | else break; | |
1779 | } | |
1780 | return len; | |
1781 | } | |
007583c9 | 1782 | |
96de1e66 N |
1783 | static struct md_sysfs_entry |
1784 | raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, | |
1785 | raid5_show_stripe_cache_size, | |
1786 | raid5_store_stripe_cache_size); | |
3f294f4f N |
1787 | |
1788 | static ssize_t | |
96de1e66 | 1789 | stripe_cache_active_show(mddev_t *mddev, char *page) |
3f294f4f | 1790 | { |
007583c9 | 1791 | raid5_conf_t *conf = mddev_to_conf(mddev); |
96de1e66 N |
1792 | if (conf) |
1793 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); | |
1794 | else | |
1795 | return 0; | |
3f294f4f N |
1796 | } |
1797 | ||
96de1e66 N |
1798 | static struct md_sysfs_entry |
1799 | raid5_stripecache_active = __ATTR_RO(stripe_cache_active); | |
3f294f4f | 1800 | |
007583c9 | 1801 | static struct attribute *raid5_attrs[] = { |
3f294f4f N |
1802 | &raid5_stripecache_size.attr, |
1803 | &raid5_stripecache_active.attr, | |
1804 | NULL, | |
1805 | }; | |
007583c9 N |
1806 | static struct attribute_group raid5_attrs_group = { |
1807 | .name = NULL, | |
1808 | .attrs = raid5_attrs, | |
3f294f4f N |
1809 | }; |
1810 | ||
72626685 | 1811 | static int run(mddev_t *mddev) |
1da177e4 LT |
1812 | { |
1813 | raid5_conf_t *conf; | |
1814 | int raid_disk, memory; | |
1815 | mdk_rdev_t *rdev; | |
1816 | struct disk_info *disk; | |
1817 | struct list_head *tmp; | |
1818 | ||
1819 | if (mddev->level != 5 && mddev->level != 4) { | |
14f8d26b N |
1820 | printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n", |
1821 | mdname(mddev), mddev->level); | |
1da177e4 LT |
1822 | return -EIO; |
1823 | } | |
1824 | ||
b55e6bfc | 1825 | mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL); |
1da177e4 LT |
1826 | if ((conf = mddev->private) == NULL) |
1827 | goto abort; | |
b55e6bfc N |
1828 | conf->disks = kzalloc(mddev->raid_disks * sizeof(struct disk_info), |
1829 | GFP_KERNEL); | |
1830 | if (!conf->disks) | |
1831 | goto abort; | |
9ffae0cf | 1832 | |
1da177e4 LT |
1833 | conf->mddev = mddev; |
1834 | ||
fccddba0 | 1835 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) |
1da177e4 | 1836 | goto abort; |
1da177e4 LT |
1837 | |
1838 | spin_lock_init(&conf->device_lock); | |
1839 | init_waitqueue_head(&conf->wait_for_stripe); | |
1840 | init_waitqueue_head(&conf->wait_for_overlap); | |
1841 | INIT_LIST_HEAD(&conf->handle_list); | |
1842 | INIT_LIST_HEAD(&conf->delayed_list); | |
72626685 | 1843 | INIT_LIST_HEAD(&conf->bitmap_list); |
1da177e4 LT |
1844 | INIT_LIST_HEAD(&conf->inactive_list); |
1845 | atomic_set(&conf->active_stripes, 0); | |
1846 | atomic_set(&conf->preread_active_stripes, 0); | |
1847 | ||
1da177e4 LT |
1848 | PRINTK("raid5: run(%s) called.\n", mdname(mddev)); |
1849 | ||
1850 | ITERATE_RDEV(mddev,rdev,tmp) { | |
1851 | raid_disk = rdev->raid_disk; | |
1852 | if (raid_disk >= mddev->raid_disks | |
1853 | || raid_disk < 0) | |
1854 | continue; | |
1855 | disk = conf->disks + raid_disk; | |
1856 | ||
1857 | disk->rdev = rdev; | |
1858 | ||
b2d444d7 | 1859 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
1860 | char b[BDEVNAME_SIZE]; |
1861 | printk(KERN_INFO "raid5: device %s operational as raid" | |
1862 | " disk %d\n", bdevname(rdev->bdev,b), | |
1863 | raid_disk); | |
1864 | conf->working_disks++; | |
1865 | } | |
1866 | } | |
1867 | ||
1868 | conf->raid_disks = mddev->raid_disks; | |
1869 | /* | |
1870 | * 0 for a fully functional array, 1 for a degraded array. | |
1871 | */ | |
1872 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; | |
1873 | conf->mddev = mddev; | |
1874 | conf->chunk_size = mddev->chunk_size; | |
1875 | conf->level = mddev->level; | |
1876 | conf->algorithm = mddev->layout; | |
1877 | conf->max_nr_stripes = NR_STRIPES; | |
1878 | ||
1879 | /* device size must be a multiple of chunk size */ | |
1880 | mddev->size &= ~(mddev->chunk_size/1024 -1); | |
b1581566 | 1881 | mddev->resync_max_sectors = mddev->size << 1; |
1da177e4 LT |
1882 | |
1883 | if (!conf->chunk_size || conf->chunk_size % 4) { | |
1884 | printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", | |
1885 | conf->chunk_size, mdname(mddev)); | |
1886 | goto abort; | |
1887 | } | |
1888 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { | |
1889 | printk(KERN_ERR | |
1890 | "raid5: unsupported parity algorithm %d for %s\n", | |
1891 | conf->algorithm, mdname(mddev)); | |
1892 | goto abort; | |
1893 | } | |
1894 | if (mddev->degraded > 1) { | |
1895 | printk(KERN_ERR "raid5: not enough operational devices for %s" | |
1896 | " (%d/%d failed)\n", | |
1897 | mdname(mddev), conf->failed_disks, conf->raid_disks); | |
1898 | goto abort; | |
1899 | } | |
1900 | ||
1901 | if (mddev->degraded == 1 && | |
1902 | mddev->recovery_cp != MaxSector) { | |
6ff8d8ec N |
1903 | if (mddev->ok_start_degraded) |
1904 | printk(KERN_WARNING | |
1905 | "raid5: starting dirty degraded array: %s" | |
1906 | "- data corruption possible.\n", | |
1907 | mdname(mddev)); | |
1908 | else { | |
1909 | printk(KERN_ERR | |
1910 | "raid5: cannot start dirty degraded array for %s\n", | |
1911 | mdname(mddev)); | |
1912 | goto abort; | |
1913 | } | |
1da177e4 LT |
1914 | } |
1915 | ||
1916 | { | |
1917 | mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5"); | |
1918 | if (!mddev->thread) { | |
1919 | printk(KERN_ERR | |
1920 | "raid5: couldn't allocate thread for %s\n", | |
1921 | mdname(mddev)); | |
1922 | goto abort; | |
1923 | } | |
1924 | } | |
5036805b | 1925 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + |
1da177e4 LT |
1926 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; |
1927 | if (grow_stripes(conf, conf->max_nr_stripes)) { | |
1928 | printk(KERN_ERR | |
1929 | "raid5: couldn't allocate %dkB for buffers\n", memory); | |
1930 | shrink_stripes(conf); | |
1931 | md_unregister_thread(mddev->thread); | |
1932 | goto abort; | |
1933 | } else | |
1934 | printk(KERN_INFO "raid5: allocated %dkB for %s\n", | |
1935 | memory, mdname(mddev)); | |
1936 | ||
1937 | if (mddev->degraded == 0) | |
1938 | printk("raid5: raid level %d set %s active with %d out of %d" | |
1939 | " devices, algorithm %d\n", conf->level, mdname(mddev), | |
1940 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, | |
1941 | conf->algorithm); | |
1942 | else | |
1943 | printk(KERN_ALERT "raid5: raid level %d set %s active with %d" | |
1944 | " out of %d devices, algorithm %d\n", conf->level, | |
1945 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
1946 | mddev->raid_disks, conf->algorithm); | |
1947 | ||
1948 | print_raid5_conf(conf); | |
1949 | ||
1950 | /* read-ahead size must cover two whole stripes, which is | |
1951 | * 2 * (n-1) * chunksize where 'n' is the number of raid devices | |
1952 | */ | |
1953 | { | |
1954 | int stripe = (mddev->raid_disks-1) * mddev->chunk_size | |
2d1f3b5d | 1955 | / PAGE_SIZE; |
1da177e4 LT |
1956 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) |
1957 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; | |
1958 | } | |
1959 | ||
1960 | /* Ok, everything is just fine now */ | |
007583c9 | 1961 | sysfs_create_group(&mddev->kobj, &raid5_attrs_group); |
7a5febe9 N |
1962 | |
1963 | mddev->queue->unplug_fn = raid5_unplug_device; | |
1964 | mddev->queue->issue_flush_fn = raid5_issue_flush; | |
1965 | ||
1da177e4 LT |
1966 | mddev->array_size = mddev->size * (mddev->raid_disks - 1); |
1967 | return 0; | |
1968 | abort: | |
1969 | if (conf) { | |
1970 | print_raid5_conf(conf); | |
b55e6bfc | 1971 | kfree(conf->disks); |
fccddba0 | 1972 | kfree(conf->stripe_hashtbl); |
1da177e4 LT |
1973 | kfree(conf); |
1974 | } | |
1975 | mddev->private = NULL; | |
1976 | printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); | |
1977 | return -EIO; | |
1978 | } | |
1979 | ||
1980 | ||
1981 | ||
3f294f4f | 1982 | static int stop(mddev_t *mddev) |
1da177e4 LT |
1983 | { |
1984 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
1985 | ||
1986 | md_unregister_thread(mddev->thread); | |
1987 | mddev->thread = NULL; | |
1988 | shrink_stripes(conf); | |
fccddba0 | 1989 | kfree(conf->stripe_hashtbl); |
1da177e4 | 1990 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
007583c9 | 1991 | sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); |
b55e6bfc | 1992 | kfree(conf->disks); |
96de1e66 | 1993 | kfree(conf); |
1da177e4 LT |
1994 | mddev->private = NULL; |
1995 | return 0; | |
1996 | } | |
1997 | ||
1998 | #if RAID5_DEBUG | |
1999 | static void print_sh (struct stripe_head *sh) | |
2000 | { | |
2001 | int i; | |
2002 | ||
2003 | printk("sh %llu, pd_idx %d, state %ld.\n", | |
2004 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); | |
2005 | printk("sh %llu, count %d.\n", | |
2006 | (unsigned long long)sh->sector, atomic_read(&sh->count)); | |
2007 | printk("sh %llu, ", (unsigned long long)sh->sector); | |
2008 | for (i = 0; i < sh->raid_conf->raid_disks; i++) { | |
2009 | printk("(cache%d: %p %ld) ", | |
2010 | i, sh->dev[i].page, sh->dev[i].flags); | |
2011 | } | |
2012 | printk("\n"); | |
2013 | } | |
2014 | ||
2015 | static void printall (raid5_conf_t *conf) | |
2016 | { | |
2017 | struct stripe_head *sh; | |
fccddba0 | 2018 | struct hlist_node *hn; |
1da177e4 LT |
2019 | int i; |
2020 | ||
2021 | spin_lock_irq(&conf->device_lock); | |
2022 | for (i = 0; i < NR_HASH; i++) { | |
fccddba0 | 2023 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { |
1da177e4 LT |
2024 | if (sh->raid_conf != conf) |
2025 | continue; | |
2026 | print_sh(sh); | |
2027 | } | |
2028 | } | |
2029 | spin_unlock_irq(&conf->device_lock); | |
2030 | } | |
2031 | #endif | |
2032 | ||
2033 | static void status (struct seq_file *seq, mddev_t *mddev) | |
2034 | { | |
2035 | raid5_conf_t *conf = (raid5_conf_t *) mddev->private; | |
2036 | int i; | |
2037 | ||
2038 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); | |
2039 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); | |
2040 | for (i = 0; i < conf->raid_disks; i++) | |
2041 | seq_printf (seq, "%s", | |
2042 | conf->disks[i].rdev && | |
b2d444d7 | 2043 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
2044 | seq_printf (seq, "]"); |
2045 | #if RAID5_DEBUG | |
2046 | #define D(x) \ | |
2047 | seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x)) | |
2048 | printall(conf); | |
2049 | #endif | |
2050 | } | |
2051 | ||
2052 | static void print_raid5_conf (raid5_conf_t *conf) | |
2053 | { | |
2054 | int i; | |
2055 | struct disk_info *tmp; | |
2056 | ||
2057 | printk("RAID5 conf printout:\n"); | |
2058 | if (!conf) { | |
2059 | printk("(conf==NULL)\n"); | |
2060 | return; | |
2061 | } | |
2062 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, | |
2063 | conf->working_disks, conf->failed_disks); | |
2064 | ||
2065 | for (i = 0; i < conf->raid_disks; i++) { | |
2066 | char b[BDEVNAME_SIZE]; | |
2067 | tmp = conf->disks + i; | |
2068 | if (tmp->rdev) | |
2069 | printk(" disk %d, o:%d, dev:%s\n", | |
b2d444d7 | 2070 | i, !test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
2071 | bdevname(tmp->rdev->bdev,b)); |
2072 | } | |
2073 | } | |
2074 | ||
2075 | static int raid5_spare_active(mddev_t *mddev) | |
2076 | { | |
2077 | int i; | |
2078 | raid5_conf_t *conf = mddev->private; | |
2079 | struct disk_info *tmp; | |
2080 | ||
2081 | for (i = 0; i < conf->raid_disks; i++) { | |
2082 | tmp = conf->disks + i; | |
2083 | if (tmp->rdev | |
b2d444d7 N |
2084 | && !test_bit(Faulty, &tmp->rdev->flags) |
2085 | && !test_bit(In_sync, &tmp->rdev->flags)) { | |
1da177e4 LT |
2086 | mddev->degraded--; |
2087 | conf->failed_disks--; | |
2088 | conf->working_disks++; | |
b2d444d7 | 2089 | set_bit(In_sync, &tmp->rdev->flags); |
1da177e4 LT |
2090 | } |
2091 | } | |
2092 | print_raid5_conf(conf); | |
2093 | return 0; | |
2094 | } | |
2095 | ||
2096 | static int raid5_remove_disk(mddev_t *mddev, int number) | |
2097 | { | |
2098 | raid5_conf_t *conf = mddev->private; | |
2099 | int err = 0; | |
2100 | mdk_rdev_t *rdev; | |
2101 | struct disk_info *p = conf->disks + number; | |
2102 | ||
2103 | print_raid5_conf(conf); | |
2104 | rdev = p->rdev; | |
2105 | if (rdev) { | |
b2d444d7 | 2106 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
2107 | atomic_read(&rdev->nr_pending)) { |
2108 | err = -EBUSY; | |
2109 | goto abort; | |
2110 | } | |
2111 | p->rdev = NULL; | |
fbd568a3 | 2112 | synchronize_rcu(); |
1da177e4 LT |
2113 | if (atomic_read(&rdev->nr_pending)) { |
2114 | /* lost the race, try later */ | |
2115 | err = -EBUSY; | |
2116 | p->rdev = rdev; | |
2117 | } | |
2118 | } | |
2119 | abort: | |
2120 | ||
2121 | print_raid5_conf(conf); | |
2122 | return err; | |
2123 | } | |
2124 | ||
2125 | static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
2126 | { | |
2127 | raid5_conf_t *conf = mddev->private; | |
2128 | int found = 0; | |
2129 | int disk; | |
2130 | struct disk_info *p; | |
2131 | ||
2132 | if (mddev->degraded > 1) | |
2133 | /* no point adding a device */ | |
2134 | return 0; | |
2135 | ||
2136 | /* | |
2137 | * find the disk ... | |
2138 | */ | |
2139 | for (disk=0; disk < mddev->raid_disks; disk++) | |
2140 | if ((p=conf->disks + disk)->rdev == NULL) { | |
b2d444d7 | 2141 | clear_bit(In_sync, &rdev->flags); |
1da177e4 LT |
2142 | rdev->raid_disk = disk; |
2143 | found = 1; | |
72626685 N |
2144 | if (rdev->saved_raid_disk != disk) |
2145 | conf->fullsync = 1; | |
d6065f7b | 2146 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
2147 | break; |
2148 | } | |
2149 | print_raid5_conf(conf); | |
2150 | return found; | |
2151 | } | |
2152 | ||
2153 | static int raid5_resize(mddev_t *mddev, sector_t sectors) | |
2154 | { | |
2155 | /* no resync is happening, and there is enough space | |
2156 | * on all devices, so we can resize. | |
2157 | * We need to make sure resync covers any new space. | |
2158 | * If the array is shrinking we should possibly wait until | |
2159 | * any io in the removed space completes, but it hardly seems | |
2160 | * worth it. | |
2161 | */ | |
2162 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); | |
2163 | mddev->array_size = (sectors * (mddev->raid_disks-1))>>1; | |
2164 | set_capacity(mddev->gendisk, mddev->array_size << 1); | |
2165 | mddev->changed = 1; | |
2166 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { | |
2167 | mddev->recovery_cp = mddev->size << 1; | |
2168 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
2169 | } | |
2170 | mddev->size = sectors /2; | |
4b5c7ae8 | 2171 | mddev->resync_max_sectors = sectors; |
1da177e4 LT |
2172 | return 0; |
2173 | } | |
2174 | ||
72626685 N |
2175 | static void raid5_quiesce(mddev_t *mddev, int state) |
2176 | { | |
2177 | raid5_conf_t *conf = mddev_to_conf(mddev); | |
2178 | ||
2179 | switch(state) { | |
2180 | case 1: /* stop all writes */ | |
2181 | spin_lock_irq(&conf->device_lock); | |
2182 | conf->quiesce = 1; | |
2183 | wait_event_lock_irq(conf->wait_for_stripe, | |
2184 | atomic_read(&conf->active_stripes) == 0, | |
2185 | conf->device_lock, /* nothing */); | |
2186 | spin_unlock_irq(&conf->device_lock); | |
2187 | break; | |
2188 | ||
2189 | case 0: /* re-enable writes */ | |
2190 | spin_lock_irq(&conf->device_lock); | |
2191 | conf->quiesce = 0; | |
2192 | wake_up(&conf->wait_for_stripe); | |
2193 | spin_unlock_irq(&conf->device_lock); | |
2194 | break; | |
2195 | } | |
72626685 | 2196 | } |
b15c2e57 | 2197 | |
2604b703 | 2198 | static struct mdk_personality raid5_personality = |
1da177e4 LT |
2199 | { |
2200 | .name = "raid5", | |
2604b703 | 2201 | .level = 5, |
1da177e4 LT |
2202 | .owner = THIS_MODULE, |
2203 | .make_request = make_request, | |
2204 | .run = run, | |
2205 | .stop = stop, | |
2206 | .status = status, | |
2207 | .error_handler = error, | |
2208 | .hot_add_disk = raid5_add_disk, | |
2209 | .hot_remove_disk= raid5_remove_disk, | |
2210 | .spare_active = raid5_spare_active, | |
2211 | .sync_request = sync_request, | |
2212 | .resize = raid5_resize, | |
72626685 | 2213 | .quiesce = raid5_quiesce, |
1da177e4 LT |
2214 | }; |
2215 | ||
2604b703 | 2216 | static struct mdk_personality raid4_personality = |
1da177e4 | 2217 | { |
2604b703 N |
2218 | .name = "raid4", |
2219 | .level = 4, | |
2220 | .owner = THIS_MODULE, | |
2221 | .make_request = make_request, | |
2222 | .run = run, | |
2223 | .stop = stop, | |
2224 | .status = status, | |
2225 | .error_handler = error, | |
2226 | .hot_add_disk = raid5_add_disk, | |
2227 | .hot_remove_disk= raid5_remove_disk, | |
2228 | .spare_active = raid5_spare_active, | |
2229 | .sync_request = sync_request, | |
2230 | .resize = raid5_resize, | |
2231 | .quiesce = raid5_quiesce, | |
2232 | }; | |
2233 | ||
2234 | static int __init raid5_init(void) | |
2235 | { | |
2236 | register_md_personality(&raid5_personality); | |
2237 | register_md_personality(&raid4_personality); | |
2238 | return 0; | |
1da177e4 LT |
2239 | } |
2240 | ||
2604b703 | 2241 | static void raid5_exit(void) |
1da177e4 | 2242 | { |
2604b703 N |
2243 | unregister_md_personality(&raid5_personality); |
2244 | unregister_md_personality(&raid4_personality); | |
1da177e4 LT |
2245 | } |
2246 | ||
2247 | module_init(raid5_init); | |
2248 | module_exit(raid5_exit); | |
2249 | MODULE_LICENSE("GPL"); | |
2250 | MODULE_ALIAS("md-personality-4"); /* RAID5 */ | |
d9d166c2 N |
2251 | MODULE_ALIAS("md-raid5"); |
2252 | MODULE_ALIAS("md-raid4"); | |
2604b703 N |
2253 | MODULE_ALIAS("md-level-5"); |
2254 | MODULE_ALIAS("md-level-4"); |