blob: be008f034ada5e222c18043cf0b766426c86f03c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
NeilBrown16a53ec2006-06-26 00:27:38 -07005 * Copyright (C) 2002, 2003 H. Peter Anvin
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
NeilBrown16a53ec2006-06-26 00:27:38 -07007 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
NeilBrownae3c20c2006-07-10 04:44:17 -070021/*
22 * BITMAP UNPLUGGING:
23 *
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
26 * explanation.
27 *
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->bm_write is the number of the last batch successfully written.
31 * conf->bm_flush is the number of the last batch that was closed to
32 * new additions.
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is bm_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
39 * batch.
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
43 * miss any bits.
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/module.h>
47#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/highmem.h>
49#include <linux/bitops.h>
NeilBrownf6705572006-03-27 01:18:11 -080050#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <asm/atomic.h>
NeilBrown16a53ec2006-06-26 00:27:38 -070052#include "raid6.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
NeilBrown72626682005-09-09 16:23:54 -070054#include <linux/raid/bitmap.h>
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056/*
57 * Stripe cache
58 */
59
60#define NR_STRIPES 256
61#define STRIPE_SIZE PAGE_SIZE
62#define STRIPE_SHIFT (PAGE_SHIFT - 9)
63#define STRIPE_SECTORS (STRIPE_SIZE>>9)
64#define IO_THRESHOLD 1
NeilBrownfccddba2006-01-06 00:20:33 -080065#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#define HASH_MASK (NR_HASH - 1)
67
NeilBrownfccddba2006-01-06 00:20:33 -080068#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70/* bio's attached to a stripe+device for I/O are linked together in bi_sector
71 * order without overlap. There may be several bio's per stripe+device, and
72 * a bio could span several devices.
73 * When walking this list for a particular stripe+device, we must never proceed
74 * beyond a bio that extends past this device, as the next bio might no longer
75 * be valid.
76 * This macro is used to determine the 'next' bio in the list, given the sector
77 * of the current stripe+device
78 */
79#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
80/*
81 * The following can be used to debug the driver
82 */
83#define RAID5_DEBUG 0
84#define RAID5_PARANOIA 1
85#if RAID5_PARANOIA && defined(CONFIG_SMP)
86# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
87#else
88# define CHECK_DEVLOCK()
89#endif
90
91#define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x)))
92#if RAID5_DEBUG
93#define inline
94#define __inline__
95#endif
96
NeilBrown16a53ec2006-06-26 00:27:38 -070097#if !RAID6_USE_EMPTY_ZERO_PAGE
98/* In .bss so it's zeroed */
99const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
100#endif
101
102static inline int raid6_next_disk(int disk, int raid_disks)
103{
104 disk++;
105 return (disk < raid_disks) ? disk : 0;
106}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107static void print_raid5_conf (raid5_conf_t *conf);
108
Arjan van de Ven858119e2006-01-14 13:20:43 -0800109static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 if (atomic_dec_and_test(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200112 BUG_ON(!list_empty(&sh->lru));
113 BUG_ON(atomic_read(&conf->active_stripes)==0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 if (test_bit(STRIPE_HANDLE, &sh->state)) {
NeilBrown7c785b72006-07-10 04:44:16 -0700115 if (test_bit(STRIPE_DELAYED, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 list_add_tail(&sh->lru, &conf->delayed_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700117 blk_plug_device(conf->mddev->queue);
118 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
NeilBrownae3c20c2006-07-10 04:44:17 -0700119 sh->bm_seq - conf->seq_write > 0) {
NeilBrown72626682005-09-09 16:23:54 -0700120 list_add_tail(&sh->lru, &conf->bitmap_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700121 blk_plug_device(conf->mddev->queue);
122 } else {
NeilBrown72626682005-09-09 16:23:54 -0700123 clear_bit(STRIPE_BIT_DELAY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 list_add_tail(&sh->lru, &conf->handle_list);
NeilBrown72626682005-09-09 16:23:54 -0700125 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 md_wakeup_thread(conf->mddev->thread);
127 } else {
128 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
129 atomic_dec(&conf->preread_active_stripes);
130 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
131 md_wakeup_thread(conf->mddev->thread);
132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 atomic_dec(&conf->active_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800134 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
135 list_add_tail(&sh->lru, &conf->inactive_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 wake_up(&conf->wait_for_stripe);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -0800137 if (conf->retry_read_aligned)
138 md_wakeup_thread(conf->mddev->thread);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800139 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 }
141 }
142}
143static void release_stripe(struct stripe_head *sh)
144{
145 raid5_conf_t *conf = sh->raid_conf;
146 unsigned long flags;
NeilBrown16a53ec2006-06-26 00:27:38 -0700147
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 spin_lock_irqsave(&conf->device_lock, flags);
149 __release_stripe(conf, sh);
150 spin_unlock_irqrestore(&conf->device_lock, flags);
151}
152
NeilBrownfccddba2006-01-06 00:20:33 -0800153static inline void remove_hash(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154{
155 PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
156
NeilBrownfccddba2006-01-06 00:20:33 -0800157 hlist_del_init(&sh->hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
NeilBrown16a53ec2006-06-26 00:27:38 -0700160static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
NeilBrownfccddba2006-01-06 00:20:33 -0800162 struct hlist_head *hp = stripe_hash(conf, sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
165
166 CHECK_DEVLOCK();
NeilBrownfccddba2006-01-06 00:20:33 -0800167 hlist_add_head(&sh->hash, hp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
170
171/* find an idle stripe, make sure it is unhashed, and return it. */
172static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
173{
174 struct stripe_head *sh = NULL;
175 struct list_head *first;
176
177 CHECK_DEVLOCK();
178 if (list_empty(&conf->inactive_list))
179 goto out;
180 first = conf->inactive_list.next;
181 sh = list_entry(first, struct stripe_head, lru);
182 list_del_init(first);
183 remove_hash(sh);
184 atomic_inc(&conf->active_stripes);
185out:
186 return sh;
187}
188
189static void shrink_buffers(struct stripe_head *sh, int num)
190{
191 struct page *p;
192 int i;
193
194 for (i=0; i<num ; i++) {
195 p = sh->dev[i].page;
196 if (!p)
197 continue;
198 sh->dev[i].page = NULL;
NeilBrown2d1f3b52006-01-06 00:20:31 -0800199 put_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 }
201}
202
203static int grow_buffers(struct stripe_head *sh, int num)
204{
205 int i;
206
207 for (i=0; i<num; i++) {
208 struct page *page;
209
210 if (!(page = alloc_page(GFP_KERNEL))) {
211 return 1;
212 }
213 sh->dev[i].page = page;
214 }
215 return 0;
216}
217
218static void raid5_build_block (struct stripe_head *sh, int i);
219
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800220static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
222 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800223 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200225 BUG_ON(atomic_read(&sh->count) != 0);
226 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 CHECK_DEVLOCK();
229 PRINTK("init_stripe called, stripe %llu\n",
230 (unsigned long long)sh->sector);
231
232 remove_hash(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -0700233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 sh->sector = sector;
235 sh->pd_idx = pd_idx;
236 sh->state = 0;
237
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800238 sh->disks = disks;
239
240 for (i = sh->disks; i--; ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 struct r5dev *dev = &sh->dev[i];
242
243 if (dev->toread || dev->towrite || dev->written ||
244 test_bit(R5_LOCKED, &dev->flags)) {
245 printk("sector=%llx i=%d %p %p %p %d\n",
246 (unsigned long long)sh->sector, i, dev->toread,
247 dev->towrite, dev->written,
248 test_bit(R5_LOCKED, &dev->flags));
249 BUG();
250 }
251 dev->flags = 0;
252 raid5_build_block(sh, i);
253 }
254 insert_hash(conf, sh);
255}
256
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800257static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258{
259 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -0800260 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
262 CHECK_DEVLOCK();
263 PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
NeilBrownfccddba2006-01-06 00:20:33 -0800264 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800265 if (sh->sector == sector && sh->disks == disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 return sh;
267 PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
268 return NULL;
269}
270
271static void unplug_slaves(mddev_t *mddev);
272static void raid5_unplug_device(request_queue_t *q);
273
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800274static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
275 int pd_idx, int noblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
277 struct stripe_head *sh;
278
279 PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector);
280
281 spin_lock_irq(&conf->device_lock);
282
283 do {
NeilBrown72626682005-09-09 16:23:54 -0700284 wait_event_lock_irq(conf->wait_for_stripe,
285 conf->quiesce == 0,
286 conf->device_lock, /* nothing */);
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800287 sh = __find_stripe(conf, sector, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 if (!sh) {
289 if (!conf->inactive_blocked)
290 sh = get_free_stripe(conf);
291 if (noblock && sh == NULL)
292 break;
293 if (!sh) {
294 conf->inactive_blocked = 1;
295 wait_event_lock_irq(conf->wait_for_stripe,
296 !list_empty(&conf->inactive_list) &&
NeilBrown50368052005-12-12 02:39:17 -0800297 (atomic_read(&conf->active_stripes)
298 < (conf->max_nr_stripes *3/4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 || !conf->inactive_blocked),
300 conf->device_lock,
NeilBrownf4370782006-07-10 04:44:14 -0700301 raid5_unplug_device(conf->mddev->queue)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 );
303 conf->inactive_blocked = 0;
304 } else
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800305 init_stripe(sh, sector, pd_idx, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 } else {
307 if (atomic_read(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200308 BUG_ON(!list_empty(&sh->lru));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 } else {
310 if (!test_bit(STRIPE_HANDLE, &sh->state))
311 atomic_inc(&conf->active_stripes);
NeilBrownff4e8d92006-07-10 04:44:16 -0700312 if (list_empty(&sh->lru) &&
313 !test_bit(STRIPE_EXPANDING, &sh->state))
NeilBrown16a53ec2006-06-26 00:27:38 -0700314 BUG();
315 list_del_init(&sh->lru);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 }
317 }
318 } while (sh == NULL);
319
320 if (sh)
321 atomic_inc(&sh->count);
322
323 spin_unlock_irq(&conf->device_lock);
324 return sh;
325}
326
NeilBrown3f294f42005-11-08 21:39:25 -0800327static int grow_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328{
329 struct stripe_head *sh;
NeilBrown3f294f42005-11-08 21:39:25 -0800330 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
331 if (!sh)
332 return 0;
333 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
334 sh->raid_conf = conf;
335 spin_lock_init(&sh->lock);
336
337 if (grow_buffers(sh, conf->raid_disks)) {
338 shrink_buffers(sh, conf->raid_disks);
339 kmem_cache_free(conf->slab_cache, sh);
340 return 0;
341 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800342 sh->disks = conf->raid_disks;
NeilBrown3f294f42005-11-08 21:39:25 -0800343 /* we just created an active stripe so... */
344 atomic_set(&sh->count, 1);
345 atomic_inc(&conf->active_stripes);
346 INIT_LIST_HEAD(&sh->lru);
347 release_stripe(sh);
348 return 1;
349}
350
351static int grow_stripes(raid5_conf_t *conf, int num)
352{
Christoph Lametere18b8902006-12-06 20:33:20 -0800353 struct kmem_cache *sc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 int devs = conf->raid_disks;
355
NeilBrownad01c9e2006-03-27 01:18:07 -0800356 sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev));
357 sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev));
358 conf->active_name = 0;
359 sc = kmem_cache_create(conf->cache_name[conf->active_name],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
361 0, 0, NULL, NULL);
362 if (!sc)
363 return 1;
364 conf->slab_cache = sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800365 conf->pool_size = devs;
NeilBrown16a53ec2006-06-26 00:27:38 -0700366 while (num--)
NeilBrown3f294f42005-11-08 21:39:25 -0800367 if (!grow_one_stripe(conf))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 return 0;
370}
NeilBrown29269552006-03-27 01:18:10 -0800371
372#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrownad01c9e2006-03-27 01:18:07 -0800373static int resize_stripes(raid5_conf_t *conf, int newsize)
374{
375 /* Make all the stripes able to hold 'newsize' devices.
376 * New slots in each stripe get 'page' set to a new page.
377 *
378 * This happens in stages:
379 * 1/ create a new kmem_cache and allocate the required number of
380 * stripe_heads.
381 * 2/ gather all the old stripe_heads and tranfer the pages across
382 * to the new stripe_heads. This will have the side effect of
383 * freezing the array as once all stripe_heads have been collected,
384 * no IO will be possible. Old stripe heads are freed once their
385 * pages have been transferred over, and the old kmem_cache is
386 * freed when all stripes are done.
387 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
388 * we simple return a failre status - no need to clean anything up.
389 * 4/ allocate new pages for the new slots in the new stripe_heads.
390 * If this fails, we don't bother trying the shrink the
391 * stripe_heads down again, we just leave them as they are.
392 * As each stripe_head is processed the new one is released into
393 * active service.
394 *
395 * Once step2 is started, we cannot afford to wait for a write,
396 * so we use GFP_NOIO allocations.
397 */
398 struct stripe_head *osh, *nsh;
399 LIST_HEAD(newstripes);
400 struct disk_info *ndisks;
401 int err = 0;
Christoph Lametere18b8902006-12-06 20:33:20 -0800402 struct kmem_cache *sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800403 int i;
404
405 if (newsize <= conf->pool_size)
406 return 0; /* never bother to shrink */
407
408 /* Step 1 */
409 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
410 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
411 0, 0, NULL, NULL);
412 if (!sc)
413 return -ENOMEM;
414
415 for (i = conf->max_nr_stripes; i; i--) {
416 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
417 if (!nsh)
418 break;
419
420 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
421
422 nsh->raid_conf = conf;
423 spin_lock_init(&nsh->lock);
424
425 list_add(&nsh->lru, &newstripes);
426 }
427 if (i) {
428 /* didn't get enough, give up */
429 while (!list_empty(&newstripes)) {
430 nsh = list_entry(newstripes.next, struct stripe_head, lru);
431 list_del(&nsh->lru);
432 kmem_cache_free(sc, nsh);
433 }
434 kmem_cache_destroy(sc);
435 return -ENOMEM;
436 }
437 /* Step 2 - Must use GFP_NOIO now.
438 * OK, we have enough stripes, start collecting inactive
439 * stripes and copying them over
440 */
441 list_for_each_entry(nsh, &newstripes, lru) {
442 spin_lock_irq(&conf->device_lock);
443 wait_event_lock_irq(conf->wait_for_stripe,
444 !list_empty(&conf->inactive_list),
445 conf->device_lock,
NeilBrownb3b46be2006-03-27 01:18:16 -0800446 unplug_slaves(conf->mddev)
NeilBrownad01c9e2006-03-27 01:18:07 -0800447 );
448 osh = get_free_stripe(conf);
449 spin_unlock_irq(&conf->device_lock);
450 atomic_set(&nsh->count, 1);
451 for(i=0; i<conf->pool_size; i++)
452 nsh->dev[i].page = osh->dev[i].page;
453 for( ; i<newsize; i++)
454 nsh->dev[i].page = NULL;
455 kmem_cache_free(conf->slab_cache, osh);
456 }
457 kmem_cache_destroy(conf->slab_cache);
458
459 /* Step 3.
460 * At this point, we are holding all the stripes so the array
461 * is completely stalled, so now is a good time to resize
462 * conf->disks.
463 */
464 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
465 if (ndisks) {
466 for (i=0; i<conf->raid_disks; i++)
467 ndisks[i] = conf->disks[i];
468 kfree(conf->disks);
469 conf->disks = ndisks;
470 } else
471 err = -ENOMEM;
472
473 /* Step 4, return new stripes to service */
474 while(!list_empty(&newstripes)) {
475 nsh = list_entry(newstripes.next, struct stripe_head, lru);
476 list_del_init(&nsh->lru);
477 for (i=conf->raid_disks; i < newsize; i++)
478 if (nsh->dev[i].page == NULL) {
479 struct page *p = alloc_page(GFP_NOIO);
480 nsh->dev[i].page = p;
481 if (!p)
482 err = -ENOMEM;
483 }
484 release_stripe(nsh);
485 }
486 /* critical section pass, GFP_NOIO no longer needed */
487
488 conf->slab_cache = sc;
489 conf->active_name = 1-conf->active_name;
490 conf->pool_size = newsize;
491 return err;
492}
NeilBrown29269552006-03-27 01:18:10 -0800493#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
NeilBrown3f294f42005-11-08 21:39:25 -0800495static int drop_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496{
497 struct stripe_head *sh;
498
NeilBrown3f294f42005-11-08 21:39:25 -0800499 spin_lock_irq(&conf->device_lock);
500 sh = get_free_stripe(conf);
501 spin_unlock_irq(&conf->device_lock);
502 if (!sh)
503 return 0;
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200504 BUG_ON(atomic_read(&sh->count));
NeilBrownad01c9e2006-03-27 01:18:07 -0800505 shrink_buffers(sh, conf->pool_size);
NeilBrown3f294f42005-11-08 21:39:25 -0800506 kmem_cache_free(conf->slab_cache, sh);
507 atomic_dec(&conf->active_stripes);
508 return 1;
509}
510
511static void shrink_stripes(raid5_conf_t *conf)
512{
513 while (drop_one_stripe(conf))
514 ;
515
NeilBrown29fc7e32006-02-03 03:03:41 -0800516 if (conf->slab_cache)
517 kmem_cache_destroy(conf->slab_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 conf->slab_cache = NULL;
519}
520
NeilBrown4e5314b2005-11-08 21:39:22 -0800521static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 int error)
523{
524 struct stripe_head *sh = bi->bi_private;
525 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800526 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
NeilBrownd6950432006-07-10 04:44:20 -0700528 char b[BDEVNAME_SIZE];
529 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
531 if (bi->bi_size)
532 return 1;
533
534 for (i=0 ; i<disks; i++)
535 if (bi == &sh->dev[i].req)
536 break;
537
538 PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n",
539 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
540 uptodate);
541 if (i == disks) {
542 BUG();
543 return 0;
544 }
545
546 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 set_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrown4e5314b2005-11-08 21:39:22 -0800548 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrownd6950432006-07-10 04:44:20 -0700549 rdev = conf->disks[i].rdev;
550 printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
551 mdname(conf->mddev), STRIPE_SECTORS,
552 (unsigned long long)sh->sector + rdev->data_offset,
553 bdevname(rdev->bdev, b));
NeilBrown4e5314b2005-11-08 21:39:22 -0800554 clear_bit(R5_ReadError, &sh->dev[i].flags);
555 clear_bit(R5_ReWrite, &sh->dev[i].flags);
556 }
NeilBrownba22dcb2005-11-08 21:39:31 -0800557 if (atomic_read(&conf->disks[i].rdev->read_errors))
558 atomic_set(&conf->disks[i].rdev->read_errors, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 } else {
NeilBrownd6950432006-07-10 04:44:20 -0700560 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
NeilBrownba22dcb2005-11-08 21:39:31 -0800561 int retry = 0;
NeilBrownd6950432006-07-10 04:44:20 -0700562 rdev = conf->disks[i].rdev;
563
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -0700565 atomic_inc(&rdev->read_errors);
NeilBrownba22dcb2005-11-08 21:39:31 -0800566 if (conf->mddev->degraded)
NeilBrownd6950432006-07-10 04:44:20 -0700567 printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n",
568 mdname(conf->mddev),
569 (unsigned long long)sh->sector + rdev->data_offset,
570 bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -0800571 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
NeilBrown4e5314b2005-11-08 21:39:22 -0800572 /* Oh, no!!! */
NeilBrownd6950432006-07-10 04:44:20 -0700573 printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
574 mdname(conf->mddev),
575 (unsigned long long)sh->sector + rdev->data_offset,
576 bdn);
577 else if (atomic_read(&rdev->read_errors)
NeilBrownba22dcb2005-11-08 21:39:31 -0800578 > conf->max_nr_stripes)
NeilBrown14f8d262006-01-06 00:20:14 -0800579 printk(KERN_WARNING
NeilBrownd6950432006-07-10 04:44:20 -0700580 "raid5:%s: Too many read errors, failing device %s.\n",
581 mdname(conf->mddev), bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -0800582 else
583 retry = 1;
584 if (retry)
585 set_bit(R5_ReadError, &sh->dev[i].flags);
586 else {
NeilBrown4e5314b2005-11-08 21:39:22 -0800587 clear_bit(R5_ReadError, &sh->dev[i].flags);
588 clear_bit(R5_ReWrite, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -0700589 md_error(conf->mddev, rdev);
NeilBrownba22dcb2005-11-08 21:39:31 -0800590 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 }
592 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 clear_bit(R5_LOCKED, &sh->dev[i].flags);
594 set_bit(STRIPE_HANDLE, &sh->state);
595 release_stripe(sh);
596 return 0;
597}
598
599static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
600 int error)
601{
602 struct stripe_head *sh = bi->bi_private;
603 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800604 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
606
607 if (bi->bi_size)
608 return 1;
609
610 for (i=0 ; i<disks; i++)
611 if (bi == &sh->dev[i].req)
612 break;
613
614 PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n",
615 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
616 uptodate);
617 if (i == disks) {
618 BUG();
619 return 0;
620 }
621
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 if (!uptodate)
623 md_error(conf->mddev, conf->disks[i].rdev);
624
625 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
626
627 clear_bit(R5_LOCKED, &sh->dev[i].flags);
628 set_bit(STRIPE_HANDLE, &sh->state);
NeilBrownc04be0a2006-10-03 01:15:53 -0700629 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 return 0;
631}
632
633
634static sector_t compute_blocknr(struct stripe_head *sh, int i);
635
636static void raid5_build_block (struct stripe_head *sh, int i)
637{
638 struct r5dev *dev = &sh->dev[i];
639
640 bio_init(&dev->req);
641 dev->req.bi_io_vec = &dev->vec;
642 dev->req.bi_vcnt++;
643 dev->req.bi_max_vecs++;
644 dev->vec.bv_page = dev->page;
645 dev->vec.bv_len = STRIPE_SIZE;
646 dev->vec.bv_offset = 0;
647
648 dev->req.bi_sector = sh->sector;
649 dev->req.bi_private = sh;
650
651 dev->flags = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -0700652 dev->sector = compute_blocknr(sh, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653}
654
655static void error(mddev_t *mddev, mdk_rdev_t *rdev)
656{
657 char b[BDEVNAME_SIZE];
658 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
659 PRINTK("raid5: error called\n");
660
NeilBrownb2d444d2005-11-08 21:39:31 -0800661 if (!test_bit(Faulty, &rdev->flags)) {
NeilBrown850b2b42006-10-03 01:15:46 -0700662 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownc04be0a2006-10-03 01:15:53 -0700663 if (test_and_clear_bit(In_sync, &rdev->flags)) {
664 unsigned long flags;
665 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -0700667 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 /*
669 * if recovery was running, make sure it aborts.
670 */
671 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
672 }
NeilBrownb2d444d2005-11-08 21:39:31 -0800673 set_bit(Faulty, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 printk (KERN_ALERT
675 "raid5: Disk failure on %s, disabling device."
676 " Operation continuing on %d devices\n",
NeilBrown02c2de82006-10-03 01:15:47 -0700677 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 }
NeilBrown16a53ec2006-06-26 00:27:38 -0700679}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681/*
682 * Input: a 'big' sector number,
683 * Output: index of the data and parity disk, and the sector # in them.
684 */
685static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
686 unsigned int data_disks, unsigned int * dd_idx,
687 unsigned int * pd_idx, raid5_conf_t *conf)
688{
689 long stripe;
690 unsigned long chunk_number;
691 unsigned int chunk_offset;
692 sector_t new_sector;
693 int sectors_per_chunk = conf->chunk_size >> 9;
694
695 /* First compute the information on this sector */
696
697 /*
698 * Compute the chunk number and the sector offset inside the chunk
699 */
700 chunk_offset = sector_div(r_sector, sectors_per_chunk);
701 chunk_number = r_sector;
702 BUG_ON(r_sector != chunk_number);
703
704 /*
705 * Compute the stripe number
706 */
707 stripe = chunk_number / data_disks;
708
709 /*
710 * Compute the data disk and parity disk indexes inside the stripe
711 */
712 *dd_idx = chunk_number % data_disks;
713
714 /*
715 * Select the parity disk based on the user selected algorithm.
716 */
NeilBrown16a53ec2006-06-26 00:27:38 -0700717 switch(conf->level) {
718 case 4:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 *pd_idx = data_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -0700720 break;
721 case 5:
722 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 case ALGORITHM_LEFT_ASYMMETRIC:
724 *pd_idx = data_disks - stripe % raid_disks;
725 if (*dd_idx >= *pd_idx)
726 (*dd_idx)++;
727 break;
728 case ALGORITHM_RIGHT_ASYMMETRIC:
729 *pd_idx = stripe % raid_disks;
730 if (*dd_idx >= *pd_idx)
731 (*dd_idx)++;
732 break;
733 case ALGORITHM_LEFT_SYMMETRIC:
734 *pd_idx = data_disks - stripe % raid_disks;
735 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
736 break;
737 case ALGORITHM_RIGHT_SYMMETRIC:
738 *pd_idx = stripe % raid_disks;
739 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
740 break;
741 default:
NeilBrown14f8d262006-01-06 00:20:14 -0800742 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -0700744 }
745 break;
746 case 6:
747
748 /**** FIX THIS ****/
749 switch (conf->algorithm) {
750 case ALGORITHM_LEFT_ASYMMETRIC:
751 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
752 if (*pd_idx == raid_disks-1)
753 (*dd_idx)++; /* Q D D D P */
754 else if (*dd_idx >= *pd_idx)
755 (*dd_idx) += 2; /* D D P Q D */
756 break;
757 case ALGORITHM_RIGHT_ASYMMETRIC:
758 *pd_idx = stripe % raid_disks;
759 if (*pd_idx == raid_disks-1)
760 (*dd_idx)++; /* Q D D D P */
761 else if (*dd_idx >= *pd_idx)
762 (*dd_idx) += 2; /* D D P Q D */
763 break;
764 case ALGORITHM_LEFT_SYMMETRIC:
765 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
766 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
767 break;
768 case ALGORITHM_RIGHT_SYMMETRIC:
769 *pd_idx = stripe % raid_disks;
770 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
771 break;
772 default:
773 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
774 conf->algorithm);
775 }
776 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 }
778
779 /*
780 * Finally, compute the new sector number
781 */
782 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
783 return new_sector;
784}
785
786
787static sector_t compute_blocknr(struct stripe_head *sh, int i)
788{
789 raid5_conf_t *conf = sh->raid_conf;
NeilBrownb875e532006-12-10 02:20:49 -0800790 int raid_disks = sh->disks;
791 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 sector_t new_sector = sh->sector, check;
793 int sectors_per_chunk = conf->chunk_size >> 9;
794 sector_t stripe;
795 int chunk_offset;
796 int chunk_number, dummy1, dummy2, dd_idx = i;
797 sector_t r_sector;
798
NeilBrown16a53ec2006-06-26 00:27:38 -0700799
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 chunk_offset = sector_div(new_sector, sectors_per_chunk);
801 stripe = new_sector;
802 BUG_ON(new_sector != stripe);
803
NeilBrown16a53ec2006-06-26 00:27:38 -0700804 if (i == sh->pd_idx)
805 return 0;
806 switch(conf->level) {
807 case 4: break;
808 case 5:
809 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 case ALGORITHM_LEFT_ASYMMETRIC:
811 case ALGORITHM_RIGHT_ASYMMETRIC:
812 if (i > sh->pd_idx)
813 i--;
814 break;
815 case ALGORITHM_LEFT_SYMMETRIC:
816 case ALGORITHM_RIGHT_SYMMETRIC:
817 if (i < sh->pd_idx)
818 i += raid_disks;
819 i -= (sh->pd_idx + 1);
820 break;
821 default:
NeilBrown14f8d262006-01-06 00:20:14 -0800822 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -0700823 conf->algorithm);
824 }
825 break;
826 case 6:
NeilBrown16a53ec2006-06-26 00:27:38 -0700827 if (i == raid6_next_disk(sh->pd_idx, raid_disks))
828 return 0; /* It is the Q disk */
829 switch (conf->algorithm) {
830 case ALGORITHM_LEFT_ASYMMETRIC:
831 case ALGORITHM_RIGHT_ASYMMETRIC:
832 if (sh->pd_idx == raid_disks-1)
833 i--; /* Q D D D P */
834 else if (i > sh->pd_idx)
835 i -= 2; /* D D P Q D */
836 break;
837 case ALGORITHM_LEFT_SYMMETRIC:
838 case ALGORITHM_RIGHT_SYMMETRIC:
839 if (sh->pd_idx == raid_disks-1)
840 i--; /* Q D D D P */
841 else {
842 /* D D P Q D */
843 if (i < sh->pd_idx)
844 i += raid_disks;
845 i -= (sh->pd_idx + 2);
846 }
847 break;
848 default:
849 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -0700851 }
852 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 }
854
855 chunk_number = stripe * data_disks + i;
856 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
857
858 check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
859 if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
NeilBrown14f8d262006-01-06 00:20:14 -0800860 printk(KERN_ERR "compute_blocknr: map not correct\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 return 0;
862 }
863 return r_sector;
864}
865
866
867
868/*
NeilBrown16a53ec2006-06-26 00:27:38 -0700869 * Copy data between a page in the stripe cache, and one or more bion
870 * The page could align with the middle of the bio, or there could be
871 * several bion, each with several bio_vecs, which cover part of the page
872 * Multiple bion are linked together on bi_next. There may be extras
873 * at the end of this list. We ignore them.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 */
875static void copy_data(int frombio, struct bio *bio,
876 struct page *page,
877 sector_t sector)
878{
879 char *pa = page_address(page);
880 struct bio_vec *bvl;
881 int i;
882 int page_offset;
883
884 if (bio->bi_sector >= sector)
885 page_offset = (signed)(bio->bi_sector - sector) * 512;
886 else
887 page_offset = (signed)(sector - bio->bi_sector) * -512;
888 bio_for_each_segment(bvl, bio, i) {
889 int len = bio_iovec_idx(bio,i)->bv_len;
890 int clen;
891 int b_offset = 0;
892
893 if (page_offset < 0) {
894 b_offset = -page_offset;
895 page_offset += b_offset;
896 len -= b_offset;
897 }
898
899 if (len > 0 && page_offset + len > STRIPE_SIZE)
900 clen = STRIPE_SIZE - page_offset;
901 else clen = len;
NeilBrown16a53ec2006-06-26 00:27:38 -0700902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 if (clen > 0) {
904 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
905 if (frombio)
906 memcpy(pa+page_offset, ba+b_offset, clen);
907 else
908 memcpy(ba+b_offset, pa+page_offset, clen);
909 __bio_kunmap_atomic(ba, KM_USER0);
910 }
911 if (clen < len) /* hit end of page */
912 break;
913 page_offset += len;
914 }
915}
916
917#define check_xor() do { \
918 if (count == MAX_XOR_BLOCKS) { \
919 xor_block(count, STRIPE_SIZE, ptr); \
920 count = 1; \
921 } \
922 } while(0)
923
924
925static void compute_block(struct stripe_head *sh, int dd_idx)
926{
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800927 int i, count, disks = sh->disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 void *ptr[MAX_XOR_BLOCKS], *p;
929
930 PRINTK("compute_block, stripe %llu, idx %d\n",
931 (unsigned long long)sh->sector, dd_idx);
932
933 ptr[0] = page_address(sh->dev[dd_idx].page);
934 memset(ptr[0], 0, STRIPE_SIZE);
935 count = 1;
936 for (i = disks ; i--; ) {
937 if (i == dd_idx)
938 continue;
939 p = page_address(sh->dev[i].page);
940 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
941 ptr[count++] = p;
942 else
NeilBrown14f8d262006-01-06 00:20:14 -0800943 printk(KERN_ERR "compute_block() %d, stripe %llu, %d"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 " not present\n", dd_idx,
945 (unsigned long long)sh->sector, i);
946
947 check_xor();
948 }
949 if (count != 1)
950 xor_block(count, STRIPE_SIZE, ptr);
951 set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
952}
953
NeilBrown16a53ec2006-06-26 00:27:38 -0700954static void compute_parity5(struct stripe_head *sh, int method)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955{
956 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800957 int i, pd_idx = sh->pd_idx, disks = sh->disks, count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 void *ptr[MAX_XOR_BLOCKS];
959 struct bio *chosen;
960
NeilBrown16a53ec2006-06-26 00:27:38 -0700961 PRINTK("compute_parity5, stripe %llu, method %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 (unsigned long long)sh->sector, method);
963
964 count = 1;
965 ptr[0] = page_address(sh->dev[pd_idx].page);
966 switch(method) {
967 case READ_MODIFY_WRITE:
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200968 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 for (i=disks ; i-- ;) {
970 if (i==pd_idx)
971 continue;
972 if (sh->dev[i].towrite &&
973 test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
974 ptr[count++] = page_address(sh->dev[i].page);
975 chosen = sh->dev[i].towrite;
976 sh->dev[i].towrite = NULL;
977
978 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
979 wake_up(&conf->wait_for_overlap);
980
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200981 BUG_ON(sh->dev[i].written);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 sh->dev[i].written = chosen;
983 check_xor();
984 }
985 }
986 break;
987 case RECONSTRUCT_WRITE:
988 memset(ptr[0], 0, STRIPE_SIZE);
989 for (i= disks; i-- ;)
990 if (i!=pd_idx && sh->dev[i].towrite) {
991 chosen = sh->dev[i].towrite;
992 sh->dev[i].towrite = NULL;
993
994 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
995 wake_up(&conf->wait_for_overlap);
996
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200997 BUG_ON(sh->dev[i].written);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 sh->dev[i].written = chosen;
999 }
1000 break;
1001 case CHECK_PARITY:
1002 break;
1003 }
1004 if (count>1) {
1005 xor_block(count, STRIPE_SIZE, ptr);
1006 count = 1;
1007 }
1008
1009 for (i = disks; i--;)
1010 if (sh->dev[i].written) {
1011 sector_t sector = sh->dev[i].sector;
1012 struct bio *wbi = sh->dev[i].written;
1013 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1014 copy_data(1, wbi, sh->dev[i].page, sector);
1015 wbi = r5_next_bio(wbi, sector);
1016 }
1017
1018 set_bit(R5_LOCKED, &sh->dev[i].flags);
1019 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1020 }
1021
1022 switch(method) {
1023 case RECONSTRUCT_WRITE:
1024 case CHECK_PARITY:
1025 for (i=disks; i--;)
1026 if (i != pd_idx) {
1027 ptr[count++] = page_address(sh->dev[i].page);
1028 check_xor();
1029 }
1030 break;
1031 case READ_MODIFY_WRITE:
1032 for (i = disks; i--;)
1033 if (sh->dev[i].written) {
1034 ptr[count++] = page_address(sh->dev[i].page);
1035 check_xor();
1036 }
1037 }
1038 if (count != 1)
1039 xor_block(count, STRIPE_SIZE, ptr);
1040
1041 if (method != CHECK_PARITY) {
1042 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1043 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1044 } else
1045 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1046}
1047
NeilBrown16a53ec2006-06-26 00:27:38 -07001048static void compute_parity6(struct stripe_head *sh, int method)
1049{
1050 raid6_conf_t *conf = sh->raid_conf;
1051 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count;
1052 struct bio *chosen;
1053 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1054 void *ptrs[disks];
1055
1056 qd_idx = raid6_next_disk(pd_idx, disks);
1057 d0_idx = raid6_next_disk(qd_idx, disks);
1058
1059 PRINTK("compute_parity, stripe %llu, method %d\n",
1060 (unsigned long long)sh->sector, method);
1061
1062 switch(method) {
1063 case READ_MODIFY_WRITE:
1064 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1065 case RECONSTRUCT_WRITE:
1066 for (i= disks; i-- ;)
1067 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1068 chosen = sh->dev[i].towrite;
1069 sh->dev[i].towrite = NULL;
1070
1071 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1072 wake_up(&conf->wait_for_overlap);
1073
Eric Sesterhenn52e5f9d2006-10-03 23:33:23 +02001074 BUG_ON(sh->dev[i].written);
NeilBrown16a53ec2006-06-26 00:27:38 -07001075 sh->dev[i].written = chosen;
1076 }
1077 break;
1078 case CHECK_PARITY:
1079 BUG(); /* Not implemented yet */
1080 }
1081
1082 for (i = disks; i--;)
1083 if (sh->dev[i].written) {
1084 sector_t sector = sh->dev[i].sector;
1085 struct bio *wbi = sh->dev[i].written;
1086 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1087 copy_data(1, wbi, sh->dev[i].page, sector);
1088 wbi = r5_next_bio(wbi, sector);
1089 }
1090
1091 set_bit(R5_LOCKED, &sh->dev[i].flags);
1092 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1093 }
1094
1095// switch(method) {
1096// case RECONSTRUCT_WRITE:
1097// case CHECK_PARITY:
1098// case UPDATE_PARITY:
1099 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1100 /* FIX: Is this ordering of drives even remotely optimal? */
1101 count = 0;
1102 i = d0_idx;
1103 do {
1104 ptrs[count++] = page_address(sh->dev[i].page);
1105 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1106 printk("block %d/%d not uptodate on parity calc\n", i,count);
1107 i = raid6_next_disk(i, disks);
1108 } while ( i != d0_idx );
1109// break;
1110// }
1111
1112 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
1113
1114 switch(method) {
1115 case RECONSTRUCT_WRITE:
1116 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1117 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1118 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1119 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1120 break;
1121 case UPDATE_PARITY:
1122 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1123 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1124 break;
1125 }
1126}
1127
1128
1129/* Compute one missing block */
1130static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1131{
1132 raid6_conf_t *conf = sh->raid_conf;
1133 int i, count, disks = conf->raid_disks;
1134 void *ptr[MAX_XOR_BLOCKS], *p;
1135 int pd_idx = sh->pd_idx;
1136 int qd_idx = raid6_next_disk(pd_idx, disks);
1137
1138 PRINTK("compute_block_1, stripe %llu, idx %d\n",
1139 (unsigned long long)sh->sector, dd_idx);
1140
1141 if ( dd_idx == qd_idx ) {
1142 /* We're actually computing the Q drive */
1143 compute_parity6(sh, UPDATE_PARITY);
1144 } else {
1145 ptr[0] = page_address(sh->dev[dd_idx].page);
1146 if (!nozero) memset(ptr[0], 0, STRIPE_SIZE);
1147 count = 1;
1148 for (i = disks ; i--; ) {
1149 if (i == dd_idx || i == qd_idx)
1150 continue;
1151 p = page_address(sh->dev[i].page);
1152 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1153 ptr[count++] = p;
1154 else
1155 printk("compute_block() %d, stripe %llu, %d"
1156 " not present\n", dd_idx,
1157 (unsigned long long)sh->sector, i);
1158
1159 check_xor();
1160 }
1161 if (count != 1)
1162 xor_block(count, STRIPE_SIZE, ptr);
1163 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1164 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1165 }
1166}
1167
1168/* Compute two missing blocks */
1169static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1170{
1171 raid6_conf_t *conf = sh->raid_conf;
1172 int i, count, disks = conf->raid_disks;
1173 int pd_idx = sh->pd_idx;
1174 int qd_idx = raid6_next_disk(pd_idx, disks);
1175 int d0_idx = raid6_next_disk(qd_idx, disks);
1176 int faila, failb;
1177
1178 /* faila and failb are disk numbers relative to d0_idx */
1179 /* pd_idx become disks-2 and qd_idx become disks-1 */
1180 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
1181 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
1182
1183 BUG_ON(faila == failb);
1184 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1185
1186 PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1187 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
1188
1189 if ( failb == disks-1 ) {
1190 /* Q disk is one of the missing disks */
1191 if ( faila == disks-2 ) {
1192 /* Missing P+Q, just recompute */
1193 compute_parity6(sh, UPDATE_PARITY);
1194 return;
1195 } else {
1196 /* We're missing D+Q; recompute D from P */
1197 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0);
1198 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1199 return;
1200 }
1201 }
1202
1203 /* We're missing D+P or D+D; build pointer table */
1204 {
1205 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1206 void *ptrs[disks];
1207
1208 count = 0;
1209 i = d0_idx;
1210 do {
1211 ptrs[count++] = page_address(sh->dev[i].page);
1212 i = raid6_next_disk(i, disks);
1213 if (i != dd_idx1 && i != dd_idx2 &&
1214 !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1215 printk("compute_2 with missing block %d/%d\n", count, i);
1216 } while ( i != d0_idx );
1217
1218 if ( failb == disks-2 ) {
1219 /* We're missing D+P. */
1220 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
1221 } else {
1222 /* We're missing D+D. */
1223 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
1224 }
1225
1226 /* Both the above update both missing blocks */
1227 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1228 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1229 }
1230}
1231
1232
1233
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234/*
1235 * Each stripe/dev can have one or more bion attached.
NeilBrown16a53ec2006-06-26 00:27:38 -07001236 * toread/towrite point to the first in a chain.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 * The bi_next chain must be in order.
1238 */
1239static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1240{
1241 struct bio **bip;
1242 raid5_conf_t *conf = sh->raid_conf;
NeilBrown72626682005-09-09 16:23:54 -07001243 int firstwrite=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244
1245 PRINTK("adding bh b#%llu to stripe s#%llu\n",
1246 (unsigned long long)bi->bi_sector,
1247 (unsigned long long)sh->sector);
1248
1249
1250 spin_lock(&sh->lock);
1251 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07001252 if (forwrite) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 bip = &sh->dev[dd_idx].towrite;
NeilBrown72626682005-09-09 16:23:54 -07001254 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1255 firstwrite = 1;
1256 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 bip = &sh->dev[dd_idx].toread;
1258 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1259 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1260 goto overlap;
1261 bip = & (*bip)->bi_next;
1262 }
1263 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1264 goto overlap;
1265
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001266 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 if (*bip)
1268 bi->bi_next = *bip;
1269 *bip = bi;
1270 bi->bi_phys_segments ++;
1271 spin_unlock_irq(&conf->device_lock);
1272 spin_unlock(&sh->lock);
1273
1274 PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
1275 (unsigned long long)bi->bi_sector,
1276 (unsigned long long)sh->sector, dd_idx);
1277
NeilBrown72626682005-09-09 16:23:54 -07001278 if (conf->mddev->bitmap && firstwrite) {
NeilBrown72626682005-09-09 16:23:54 -07001279 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1280 STRIPE_SECTORS, 0);
NeilBrownae3c20c2006-07-10 04:44:17 -07001281 sh->bm_seq = conf->seq_flush+1;
NeilBrown72626682005-09-09 16:23:54 -07001282 set_bit(STRIPE_BIT_DELAY, &sh->state);
1283 }
1284
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 if (forwrite) {
1286 /* check if page is covered */
1287 sector_t sector = sh->dev[dd_idx].sector;
1288 for (bi=sh->dev[dd_idx].towrite;
1289 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1290 bi && bi->bi_sector <= sector;
1291 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1292 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1293 sector = bi->bi_sector + (bi->bi_size>>9);
1294 }
1295 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1296 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1297 }
1298 return 1;
1299
1300 overlap:
1301 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1302 spin_unlock_irq(&conf->device_lock);
1303 spin_unlock(&sh->lock);
1304 return 0;
1305}
1306
NeilBrown29269552006-03-27 01:18:10 -08001307static void end_reshape(raid5_conf_t *conf);
1308
NeilBrown16a53ec2006-06-26 00:27:38 -07001309static int page_is_zero(struct page *p)
1310{
1311 char *a = page_address(p);
1312 return ((*(u32*)a) == 0 &&
1313 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1314}
1315
NeilBrownccfcc3c2006-03-27 01:18:09 -08001316static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1317{
1318 int sectors_per_chunk = conf->chunk_size >> 9;
NeilBrownccfcc3c2006-03-27 01:18:09 -08001319 int pd_idx, dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07001320 int chunk_offset = sector_div(stripe, sectors_per_chunk);
1321
NeilBrownb875e532006-12-10 02:20:49 -08001322 raid5_compute_sector(stripe * (disks - conf->max_degraded)
1323 *sectors_per_chunk + chunk_offset,
1324 disks, disks - conf->max_degraded,
1325 &dd_idx, &pd_idx, conf);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001326 return pd_idx;
1327}
1328
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329
1330/*
1331 * handle_stripe - do things to a stripe.
1332 *
1333 * We lock the stripe and then examine the state of various bits
1334 * to see what needs to be done.
1335 * Possible results:
1336 * return some read request which now have data
1337 * return some write requests which are safely on disc
1338 * schedule a read on some buffers
1339 * schedule a write of some buffers
1340 * return confirmation of parity correctness
1341 *
1342 * Parity calculations are done inside the stripe lock
1343 * buffers are taken off read_list or write_list, and bh_cache buffers
1344 * get BH_Lock set before the stripe lock is released.
1345 *
1346 */
1347
NeilBrown16a53ec2006-06-26 00:27:38 -07001348static void handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349{
1350 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001351 int disks = sh->disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 struct bio *return_bi= NULL;
1353 struct bio *bi;
1354 int i;
NeilBrownccfcc3c2006-03-27 01:18:09 -08001355 int syncing, expanding, expanded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356 int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
1357 int non_overwrite = 0;
1358 int failed_num=0;
1359 struct r5dev *dev;
1360
1361 PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
1362 (unsigned long long)sh->sector, atomic_read(&sh->count),
1363 sh->pd_idx);
1364
1365 spin_lock(&sh->lock);
1366 clear_bit(STRIPE_HANDLE, &sh->state);
1367 clear_bit(STRIPE_DELAYED, &sh->state);
1368
1369 syncing = test_bit(STRIPE_SYNCING, &sh->state);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001370 expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
1371 expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372 /* Now to look around and see what can be done */
1373
NeilBrown9910f162006-01-06 00:20:24 -08001374 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375 for (i=disks; i--; ) {
1376 mdk_rdev_t *rdev;
1377 dev = &sh->dev[i];
1378 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379
1380 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1381 i, dev->flags, dev->toread, dev->towrite, dev->written);
1382 /* maybe we can reply to a read */
1383 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
1384 struct bio *rbi, *rbi2;
1385 PRINTK("Return read for disc %d\n", i);
1386 spin_lock_irq(&conf->device_lock);
1387 rbi = dev->toread;
1388 dev->toread = NULL;
1389 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1390 wake_up(&conf->wait_for_overlap);
1391 spin_unlock_irq(&conf->device_lock);
1392 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
1393 copy_data(0, rbi, dev->page, dev->sector);
1394 rbi2 = r5_next_bio(rbi, dev->sector);
1395 spin_lock_irq(&conf->device_lock);
1396 if (--rbi->bi_phys_segments == 0) {
1397 rbi->bi_next = return_bi;
1398 return_bi = rbi;
1399 }
1400 spin_unlock_irq(&conf->device_lock);
1401 rbi = rbi2;
1402 }
1403 }
1404
1405 /* now count some things */
1406 if (test_bit(R5_LOCKED, &dev->flags)) locked++;
1407 if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
1408
1409
1410 if (dev->toread) to_read++;
1411 if (dev->towrite) {
1412 to_write++;
1413 if (!test_bit(R5_OVERWRITE, &dev->flags))
1414 non_overwrite++;
1415 }
1416 if (dev->written) written++;
NeilBrown9910f162006-01-06 00:20:24 -08001417 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08001418 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08001419 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08001420 clear_bit(R5_ReadError, &dev->flags);
1421 clear_bit(R5_ReWrite, &dev->flags);
1422 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001423 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08001424 || test_bit(R5_ReadError, &dev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 failed++;
1426 failed_num = i;
1427 } else
1428 set_bit(R5_Insync, &dev->flags);
1429 }
NeilBrown9910f162006-01-06 00:20:24 -08001430 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 PRINTK("locked=%d uptodate=%d to_read=%d"
1432 " to_write=%d failed=%d failed_num=%d\n",
1433 locked, uptodate, to_read, to_write, failed, failed_num);
1434 /* check if the array has lost two devices and, if so, some requests might
1435 * need to be failed
1436 */
1437 if (failed > 1 && to_read+to_write+written) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 for (i=disks; i--; ) {
NeilBrown72626682005-09-09 16:23:54 -07001439 int bitmap_end = 0;
NeilBrown4e5314b2005-11-08 21:39:22 -08001440
1441 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrown9910f162006-01-06 00:20:24 -08001442 mdk_rdev_t *rdev;
1443 rcu_read_lock();
1444 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08001445 if (rdev && test_bit(In_sync, &rdev->flags))
NeilBrown4e5314b2005-11-08 21:39:22 -08001446 /* multiple read failures in one stripe */
1447 md_error(conf->mddev, rdev);
NeilBrown9910f162006-01-06 00:20:24 -08001448 rcu_read_unlock();
NeilBrown4e5314b2005-11-08 21:39:22 -08001449 }
1450
NeilBrown72626682005-09-09 16:23:54 -07001451 spin_lock_irq(&conf->device_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452 /* fail all writes first */
1453 bi = sh->dev[i].towrite;
1454 sh->dev[i].towrite = NULL;
NeilBrown72626682005-09-09 16:23:54 -07001455 if (bi) { to_write--; bitmap_end = 1; }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456
1457 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1458 wake_up(&conf->wait_for_overlap);
1459
1460 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
1461 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
1462 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1463 if (--bi->bi_phys_segments == 0) {
1464 md_write_end(conf->mddev);
1465 bi->bi_next = return_bi;
1466 return_bi = bi;
1467 }
1468 bi = nextbi;
1469 }
1470 /* and fail all 'written' */
1471 bi = sh->dev[i].written;
1472 sh->dev[i].written = NULL;
NeilBrown72626682005-09-09 16:23:54 -07001473 if (bi) bitmap_end = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
1475 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
1476 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1477 if (--bi->bi_phys_segments == 0) {
1478 md_write_end(conf->mddev);
1479 bi->bi_next = return_bi;
1480 return_bi = bi;
1481 }
1482 bi = bi2;
1483 }
1484
1485 /* fail any reads if this device is non-operational */
NeilBrown4e5314b2005-11-08 21:39:22 -08001486 if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
1487 test_bit(R5_ReadError, &sh->dev[i].flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 bi = sh->dev[i].toread;
1489 sh->dev[i].toread = NULL;
1490 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1491 wake_up(&conf->wait_for_overlap);
1492 if (bi) to_read--;
1493 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
1494 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
1495 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1496 if (--bi->bi_phys_segments == 0) {
1497 bi->bi_next = return_bi;
1498 return_bi = bi;
1499 }
1500 bi = nextbi;
1501 }
1502 }
NeilBrown72626682005-09-09 16:23:54 -07001503 spin_unlock_irq(&conf->device_lock);
1504 if (bitmap_end)
1505 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
1506 STRIPE_SECTORS, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 }
1509 if (failed > 1 && syncing) {
1510 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
1511 clear_bit(STRIPE_SYNCING, &sh->state);
1512 syncing = 0;
1513 }
1514
1515 /* might be able to return some write requests if the parity block
1516 * is safe, or on a failed drive
1517 */
1518 dev = &sh->dev[sh->pd_idx];
1519 if ( written &&
1520 ( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) &&
1521 test_bit(R5_UPTODATE, &dev->flags))
1522 || (failed == 1 && failed_num == sh->pd_idx))
1523 ) {
1524 /* any written block on an uptodate or failed drive can be returned.
1525 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
1526 * never LOCKED, so we don't need to test 'failed' directly.
1527 */
1528 for (i=disks; i--; )
1529 if (sh->dev[i].written) {
1530 dev = &sh->dev[i];
1531 if (!test_bit(R5_LOCKED, &dev->flags) &&
1532 test_bit(R5_UPTODATE, &dev->flags) ) {
1533 /* We can return any write requests */
1534 struct bio *wbi, *wbi2;
NeilBrown72626682005-09-09 16:23:54 -07001535 int bitmap_end = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 PRINTK("Return write for disc %d\n", i);
1537 spin_lock_irq(&conf->device_lock);
1538 wbi = dev->written;
1539 dev->written = NULL;
1540 while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
1541 wbi2 = r5_next_bio(wbi, dev->sector);
1542 if (--wbi->bi_phys_segments == 0) {
1543 md_write_end(conf->mddev);
1544 wbi->bi_next = return_bi;
1545 return_bi = wbi;
1546 }
1547 wbi = wbi2;
1548 }
NeilBrown72626682005-09-09 16:23:54 -07001549 if (dev->towrite == NULL)
1550 bitmap_end = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07001552 if (bitmap_end)
1553 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
1554 STRIPE_SECTORS,
1555 !test_bit(STRIPE_DEGRADED, &sh->state), 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 }
1557 }
1558 }
1559
1560 /* Now we might consider reading some blocks, either to check/generate
1561 * parity, or to satisfy requests
1562 * or to load a block that is being partially written.
1563 */
NeilBrownccfcc3c2006-03-27 01:18:09 -08001564 if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 for (i=disks; i--;) {
1566 dev = &sh->dev[i];
1567 if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
1568 (dev->toread ||
1569 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
1570 syncing ||
NeilBrownccfcc3c2006-03-27 01:18:09 -08001571 expanding ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572 (failed && (sh->dev[failed_num].toread ||
1573 (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags))))
1574 )
1575 ) {
1576 /* we would like to get this block, possibly
1577 * by computing it, but we might not be able to
1578 */
1579 if (uptodate == disks-1) {
1580 PRINTK("Computing block %d\n", i);
1581 compute_block(sh, i);
1582 uptodate++;
1583 } else if (test_bit(R5_Insync, &dev->flags)) {
1584 set_bit(R5_LOCKED, &dev->flags);
1585 set_bit(R5_Wantread, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 locked++;
1587 PRINTK("Reading block %d (sync=%d)\n",
1588 i, syncing);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589 }
1590 }
1591 }
1592 set_bit(STRIPE_HANDLE, &sh->state);
1593 }
1594
1595 /* now to consider writing and what else, if anything should be read */
1596 if (to_write) {
1597 int rmw=0, rcw=0;
1598 for (i=disks ; i--;) {
1599 /* would I have to read this buffer for read_modify_write */
1600 dev = &sh->dev[i];
1601 if ((dev->towrite || i == sh->pd_idx) &&
1602 (!test_bit(R5_LOCKED, &dev->flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 ) &&
1604 !test_bit(R5_UPTODATE, &dev->flags)) {
1605 if (test_bit(R5_Insync, &dev->flags)
1606/* && !(!mddev->insync && i == sh->pd_idx) */
1607 )
1608 rmw++;
1609 else rmw += 2*disks; /* cannot read it */
1610 }
1611 /* Would I have to read this buffer for reconstruct_write */
1612 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
1613 (!test_bit(R5_LOCKED, &dev->flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 ) &&
1615 !test_bit(R5_UPTODATE, &dev->flags)) {
1616 if (test_bit(R5_Insync, &dev->flags)) rcw++;
1617 else rcw += 2*disks;
1618 }
1619 }
1620 PRINTK("for sector %llu, rmw=%d rcw=%d\n",
1621 (unsigned long long)sh->sector, rmw, rcw);
1622 set_bit(STRIPE_HANDLE, &sh->state);
1623 if (rmw < rcw && rmw > 0)
1624 /* prefer read-modify-write, but need to get some data */
1625 for (i=disks; i--;) {
1626 dev = &sh->dev[i];
1627 if ((dev->towrite || i == sh->pd_idx) &&
1628 !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
1629 test_bit(R5_Insync, &dev->flags)) {
1630 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
1631 {
1632 PRINTK("Read_old block %d for r-m-w\n", i);
1633 set_bit(R5_LOCKED, &dev->flags);
1634 set_bit(R5_Wantread, &dev->flags);
1635 locked++;
1636 } else {
1637 set_bit(STRIPE_DELAYED, &sh->state);
1638 set_bit(STRIPE_HANDLE, &sh->state);
1639 }
1640 }
1641 }
1642 if (rcw <= rmw && rcw > 0)
1643 /* want reconstruct write, but need to get some data */
1644 for (i=disks; i--;) {
1645 dev = &sh->dev[i];
1646 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
1647 !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
1648 test_bit(R5_Insync, &dev->flags)) {
1649 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
1650 {
1651 PRINTK("Read_old block %d for Reconstruct\n", i);
1652 set_bit(R5_LOCKED, &dev->flags);
1653 set_bit(R5_Wantread, &dev->flags);
1654 locked++;
1655 } else {
1656 set_bit(STRIPE_DELAYED, &sh->state);
1657 set_bit(STRIPE_HANDLE, &sh->state);
1658 }
1659 }
1660 }
1661 /* now if nothing is locked, and if we have enough data, we can start a write request */
NeilBrown72626682005-09-09 16:23:54 -07001662 if (locked == 0 && (rcw == 0 ||rmw == 0) &&
1663 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 PRINTK("Computing parity...\n");
NeilBrown16a53ec2006-06-26 00:27:38 -07001665 compute_parity5(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 /* now every locked buffer is ready to be written */
1667 for (i=disks; i--;)
1668 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
1669 PRINTK("Writing block %d\n", i);
1670 locked++;
1671 set_bit(R5_Wantwrite, &sh->dev[i].flags);
1672 if (!test_bit(R5_Insync, &sh->dev[i].flags)
1673 || (i==sh->pd_idx && failed == 0))
1674 set_bit(STRIPE_INSYNC, &sh->state);
1675 }
1676 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
1677 atomic_dec(&conf->preread_active_stripes);
1678 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
1679 md_wakeup_thread(conf->mddev->thread);
1680 }
1681 }
1682 }
1683
1684 /* maybe we need to check and possibly fix the parity for this stripe
1685 * Any reads will already have been scheduled, so we just see if enough data
1686 * is available
1687 */
1688 if (syncing && locked == 0 &&
NeilBrown14f8d262006-01-06 00:20:14 -08001689 !test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 set_bit(STRIPE_HANDLE, &sh->state);
1691 if (failed == 0) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001692 BUG_ON(uptodate != disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07001693 compute_parity5(sh, CHECK_PARITY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 uptodate--;
NeilBrown16a53ec2006-06-26 00:27:38 -07001695 if (page_is_zero(sh->dev[sh->pd_idx].page)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696 /* parity is correct (on disc, not in buffer any more) */
1697 set_bit(STRIPE_INSYNC, &sh->state);
NeilBrown9d888832005-11-08 21:39:26 -08001698 } else {
1699 conf->mddev->resync_mismatches += STRIPE_SECTORS;
1700 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
1701 /* don't try to repair!! */
1702 set_bit(STRIPE_INSYNC, &sh->state);
NeilBrown14f8d262006-01-06 00:20:14 -08001703 else {
1704 compute_block(sh, sh->pd_idx);
1705 uptodate++;
1706 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 }
1708 }
1709 if (!test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown14f8d262006-01-06 00:20:14 -08001710 /* either failed parity check, or recovery is happening */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 if (failed==0)
1712 failed_num = sh->pd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 dev = &sh->dev[failed_num];
NeilBrown14f8d262006-01-06 00:20:14 -08001714 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
1715 BUG_ON(uptodate != disks);
1716
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 set_bit(R5_LOCKED, &dev->flags);
1718 set_bit(R5_Wantwrite, &dev->flags);
NeilBrown72626682005-09-09 16:23:54 -07001719 clear_bit(STRIPE_DEGRADED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 locked++;
1721 set_bit(STRIPE_INSYNC, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001722 }
1723 }
1724 if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
1725 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
1726 clear_bit(STRIPE_SYNCING, &sh->state);
1727 }
NeilBrown4e5314b2005-11-08 21:39:22 -08001728
1729 /* If the failed drive is just a ReadError, then we might need to progress
1730 * the repair/check process
1731 */
NeilBrownba22dcb2005-11-08 21:39:31 -08001732 if (failed == 1 && ! conf->mddev->ro &&
1733 test_bit(R5_ReadError, &sh->dev[failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08001734 && !test_bit(R5_LOCKED, &sh->dev[failed_num].flags)
1735 && test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)
1736 ) {
1737 dev = &sh->dev[failed_num];
1738 if (!test_bit(R5_ReWrite, &dev->flags)) {
1739 set_bit(R5_Wantwrite, &dev->flags);
1740 set_bit(R5_ReWrite, &dev->flags);
1741 set_bit(R5_LOCKED, &dev->flags);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001742 locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08001743 } else {
1744 /* let's read it back */
1745 set_bit(R5_Wantread, &dev->flags);
1746 set_bit(R5_LOCKED, &dev->flags);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001747 locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08001748 }
1749 }
1750
NeilBrownccfcc3c2006-03-27 01:18:09 -08001751 if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
1752 /* Need to write out all blocks after computing parity */
1753 sh->disks = conf->raid_disks;
1754 sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07001755 compute_parity5(sh, RECONSTRUCT_WRITE);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001756 for (i= conf->raid_disks; i--;) {
1757 set_bit(R5_LOCKED, &sh->dev[i].flags);
1758 locked++;
1759 set_bit(R5_Wantwrite, &sh->dev[i].flags);
1760 }
1761 clear_bit(STRIPE_EXPANDING, &sh->state);
1762 } else if (expanded) {
1763 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08001764 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001765 wake_up(&conf->wait_for_overlap);
1766 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
1767 }
1768
1769 if (expanding && locked == 0) {
1770 /* We have read all the blocks in this stripe and now we need to
1771 * copy some of them into a target stripe for expand.
1772 */
1773 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
1774 for (i=0; i< sh->disks; i++)
1775 if (i != sh->pd_idx) {
1776 int dd_idx, pd_idx, j;
1777 struct stripe_head *sh2;
1778
1779 sector_t bn = compute_blocknr(sh, i);
1780 sector_t s = raid5_compute_sector(bn, conf->raid_disks,
1781 conf->raid_disks-1,
1782 &dd_idx, &pd_idx, conf);
1783 sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1);
1784 if (sh2 == NULL)
1785 /* so far only the early blocks of this stripe
1786 * have been requested. When later blocks
1787 * get requested, we will try again
1788 */
1789 continue;
1790 if(!test_bit(STRIPE_EXPANDING, &sh2->state) ||
1791 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
1792 /* must have already done this block */
1793 release_stripe(sh2);
1794 continue;
1795 }
1796 memcpy(page_address(sh2->dev[dd_idx].page),
1797 page_address(sh->dev[i].page),
1798 STRIPE_SIZE);
1799 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
1800 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
1801 for (j=0; j<conf->raid_disks; j++)
1802 if (j != sh2->pd_idx &&
1803 !test_bit(R5_Expanded, &sh2->dev[j].flags))
1804 break;
1805 if (j == conf->raid_disks) {
1806 set_bit(STRIPE_EXPAND_READY, &sh2->state);
1807 set_bit(STRIPE_HANDLE, &sh2->state);
1808 }
1809 release_stripe(sh2);
1810 }
1811 }
1812
Linus Torvalds1da177e2005-04-16 15:20:36 -07001813 spin_unlock(&sh->lock);
1814
1815 while ((bi=return_bi)) {
1816 int bytes = bi->bi_size;
1817
1818 return_bi = bi->bi_next;
1819 bi->bi_next = NULL;
1820 bi->bi_size = 0;
NeilBrownc2b00852006-12-10 02:20:51 -08001821 bi->bi_end_io(bi, bytes,
1822 test_bit(BIO_UPTODATE, &bi->bi_flags)
1823 ? 0 : -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 }
1825 for (i=disks; i-- ;) {
1826 int rw;
1827 struct bio *bi;
1828 mdk_rdev_t *rdev;
1829 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08001830 rw = WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08001832 rw = READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833 else
1834 continue;
1835
1836 bi = &sh->dev[i].req;
1837
1838 bi->bi_rw = rw;
NeilBrown802ba062006-12-13 00:34:13 -08001839 if (rw == WRITE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840 bi->bi_end_io = raid5_end_write_request;
1841 else
1842 bi->bi_end_io = raid5_end_read_request;
1843
1844 rcu_read_lock();
Suzanne Woodd6065f72005-11-08 21:39:27 -08001845 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08001846 if (rdev && test_bit(Faulty, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 rdev = NULL;
1848 if (rdev)
1849 atomic_inc(&rdev->nr_pending);
1850 rcu_read_unlock();
1851
1852 if (rdev) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08001853 if (syncing || expanding || expanded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001854 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
1855
1856 bi->bi_bdev = rdev->bdev;
1857 PRINTK("for %llu schedule op %ld on disc %d\n",
1858 (unsigned long long)sh->sector, bi->bi_rw, i);
1859 atomic_inc(&sh->count);
1860 bi->bi_sector = sh->sector + rdev->data_offset;
1861 bi->bi_flags = 1 << BIO_UPTODATE;
1862 bi->bi_vcnt = 1;
1863 bi->bi_max_vecs = 1;
1864 bi->bi_idx = 0;
1865 bi->bi_io_vec = &sh->dev[i].vec;
1866 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1867 bi->bi_io_vec[0].bv_offset = 0;
1868 bi->bi_size = STRIPE_SIZE;
1869 bi->bi_next = NULL;
NeilBrown4dbcdc72006-01-06 00:20:52 -08001870 if (rw == WRITE &&
1871 test_bit(R5_ReWrite, &sh->dev[i].flags))
1872 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 generic_make_request(bi);
1874 } else {
NeilBrown802ba062006-12-13 00:34:13 -08001875 if (rw == WRITE)
NeilBrown72626682005-09-09 16:23:54 -07001876 set_bit(STRIPE_DEGRADED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877 PRINTK("skip op %ld on disc %d for sector %llu\n",
1878 bi->bi_rw, i, (unsigned long long)sh->sector);
1879 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1880 set_bit(STRIPE_HANDLE, &sh->state);
1881 }
1882 }
1883}
1884
NeilBrown16a53ec2006-06-26 00:27:38 -07001885static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
1886{
1887 raid6_conf_t *conf = sh->raid_conf;
1888 int disks = conf->raid_disks;
1889 struct bio *return_bi= NULL;
1890 struct bio *bi;
1891 int i;
1892 int syncing;
1893 int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
1894 int non_overwrite = 0;
1895 int failed_num[2] = {0, 0};
1896 struct r5dev *dev, *pdev, *qdev;
1897 int pd_idx = sh->pd_idx;
1898 int qd_idx = raid6_next_disk(pd_idx, disks);
1899 int p_failed, q_failed;
1900
1901 PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n",
1902 (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count),
1903 pd_idx, qd_idx);
1904
1905 spin_lock(&sh->lock);
1906 clear_bit(STRIPE_HANDLE, &sh->state);
1907 clear_bit(STRIPE_DELAYED, &sh->state);
1908
1909 syncing = test_bit(STRIPE_SYNCING, &sh->state);
1910 /* Now to look around and see what can be done */
1911
1912 rcu_read_lock();
1913 for (i=disks; i--; ) {
1914 mdk_rdev_t *rdev;
1915 dev = &sh->dev[i];
1916 clear_bit(R5_Insync, &dev->flags);
1917
1918 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1919 i, dev->flags, dev->toread, dev->towrite, dev->written);
1920 /* maybe we can reply to a read */
1921 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
1922 struct bio *rbi, *rbi2;
1923 PRINTK("Return read for disc %d\n", i);
1924 spin_lock_irq(&conf->device_lock);
1925 rbi = dev->toread;
1926 dev->toread = NULL;
1927 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1928 wake_up(&conf->wait_for_overlap);
1929 spin_unlock_irq(&conf->device_lock);
1930 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
1931 copy_data(0, rbi, dev->page, dev->sector);
1932 rbi2 = r5_next_bio(rbi, dev->sector);
1933 spin_lock_irq(&conf->device_lock);
1934 if (--rbi->bi_phys_segments == 0) {
1935 rbi->bi_next = return_bi;
1936 return_bi = rbi;
1937 }
1938 spin_unlock_irq(&conf->device_lock);
1939 rbi = rbi2;
1940 }
1941 }
1942
1943 /* now count some things */
1944 if (test_bit(R5_LOCKED, &dev->flags)) locked++;
1945 if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
1946
1947
1948 if (dev->toread) to_read++;
1949 if (dev->towrite) {
1950 to_write++;
1951 if (!test_bit(R5_OVERWRITE, &dev->flags))
1952 non_overwrite++;
1953 }
1954 if (dev->written) written++;
1955 rdev = rcu_dereference(conf->disks[i].rdev);
1956 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
1957 /* The ReadError flag will just be confusing now */
1958 clear_bit(R5_ReadError, &dev->flags);
1959 clear_bit(R5_ReWrite, &dev->flags);
1960 }
1961 if (!rdev || !test_bit(In_sync, &rdev->flags)
1962 || test_bit(R5_ReadError, &dev->flags)) {
1963 if ( failed < 2 )
1964 failed_num[failed] = i;
1965 failed++;
1966 } else
1967 set_bit(R5_Insync, &dev->flags);
1968 }
1969 rcu_read_unlock();
1970 PRINTK("locked=%d uptodate=%d to_read=%d"
1971 " to_write=%d failed=%d failed_num=%d,%d\n",
1972 locked, uptodate, to_read, to_write, failed,
1973 failed_num[0], failed_num[1]);
1974 /* check if the array has lost >2 devices and, if so, some requests might
1975 * need to be failed
1976 */
1977 if (failed > 2 && to_read+to_write+written) {
1978 for (i=disks; i--; ) {
1979 int bitmap_end = 0;
1980
1981 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1982 mdk_rdev_t *rdev;
1983 rcu_read_lock();
1984 rdev = rcu_dereference(conf->disks[i].rdev);
1985 if (rdev && test_bit(In_sync, &rdev->flags))
1986 /* multiple read failures in one stripe */
1987 md_error(conf->mddev, rdev);
1988 rcu_read_unlock();
1989 }
1990
1991 spin_lock_irq(&conf->device_lock);
1992 /* fail all writes first */
1993 bi = sh->dev[i].towrite;
1994 sh->dev[i].towrite = NULL;
1995 if (bi) { to_write--; bitmap_end = 1; }
1996
1997 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1998 wake_up(&conf->wait_for_overlap);
1999
2000 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
2001 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2002 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2003 if (--bi->bi_phys_segments == 0) {
2004 md_write_end(conf->mddev);
2005 bi->bi_next = return_bi;
2006 return_bi = bi;
2007 }
2008 bi = nextbi;
2009 }
2010 /* and fail all 'written' */
2011 bi = sh->dev[i].written;
2012 sh->dev[i].written = NULL;
2013 if (bi) bitmap_end = 1;
2014 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
2015 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2016 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2017 if (--bi->bi_phys_segments == 0) {
2018 md_write_end(conf->mddev);
2019 bi->bi_next = return_bi;
2020 return_bi = bi;
2021 }
2022 bi = bi2;
2023 }
2024
2025 /* fail any reads if this device is non-operational */
2026 if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2027 test_bit(R5_ReadError, &sh->dev[i].flags)) {
2028 bi = sh->dev[i].toread;
2029 sh->dev[i].toread = NULL;
2030 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2031 wake_up(&conf->wait_for_overlap);
2032 if (bi) to_read--;
2033 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
2034 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2035 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2036 if (--bi->bi_phys_segments == 0) {
2037 bi->bi_next = return_bi;
2038 return_bi = bi;
2039 }
2040 bi = nextbi;
2041 }
2042 }
2043 spin_unlock_irq(&conf->device_lock);
2044 if (bitmap_end)
2045 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2046 STRIPE_SECTORS, 0, 0);
2047 }
2048 }
2049 if (failed > 2 && syncing) {
2050 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2051 clear_bit(STRIPE_SYNCING, &sh->state);
2052 syncing = 0;
2053 }
2054
2055 /*
2056 * might be able to return some write requests if the parity blocks
2057 * are safe, or on a failed drive
2058 */
2059 pdev = &sh->dev[pd_idx];
2060 p_failed = (failed >= 1 && failed_num[0] == pd_idx)
2061 || (failed >= 2 && failed_num[1] == pd_idx);
2062 qdev = &sh->dev[qd_idx];
2063 q_failed = (failed >= 1 && failed_num[0] == qd_idx)
2064 || (failed >= 2 && failed_num[1] == qd_idx);
2065
2066 if ( written &&
2067 ( p_failed || ((test_bit(R5_Insync, &pdev->flags)
2068 && !test_bit(R5_LOCKED, &pdev->flags)
2069 && test_bit(R5_UPTODATE, &pdev->flags))) ) &&
2070 ( q_failed || ((test_bit(R5_Insync, &qdev->flags)
2071 && !test_bit(R5_LOCKED, &qdev->flags)
2072 && test_bit(R5_UPTODATE, &qdev->flags))) ) ) {
2073 /* any written block on an uptodate or failed drive can be
2074 * returned. Note that if we 'wrote' to a failed drive,
2075 * it will be UPTODATE, but never LOCKED, so we don't need
2076 * to test 'failed' directly.
2077 */
2078 for (i=disks; i--; )
2079 if (sh->dev[i].written) {
2080 dev = &sh->dev[i];
2081 if (!test_bit(R5_LOCKED, &dev->flags) &&
2082 test_bit(R5_UPTODATE, &dev->flags) ) {
2083 /* We can return any write requests */
2084 int bitmap_end = 0;
2085 struct bio *wbi, *wbi2;
2086 PRINTK("Return write for stripe %llu disc %d\n",
2087 (unsigned long long)sh->sector, i);
2088 spin_lock_irq(&conf->device_lock);
2089 wbi = dev->written;
2090 dev->written = NULL;
2091 while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2092 wbi2 = r5_next_bio(wbi, dev->sector);
2093 if (--wbi->bi_phys_segments == 0) {
2094 md_write_end(conf->mddev);
2095 wbi->bi_next = return_bi;
2096 return_bi = wbi;
2097 }
2098 wbi = wbi2;
2099 }
2100 if (dev->towrite == NULL)
2101 bitmap_end = 1;
2102 spin_unlock_irq(&conf->device_lock);
2103 if (bitmap_end)
2104 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2105 STRIPE_SECTORS,
2106 !test_bit(STRIPE_DEGRADED, &sh->state), 0);
2107 }
2108 }
2109 }
2110
2111 /* Now we might consider reading some blocks, either to check/generate
2112 * parity, or to satisfy requests
2113 * or to load a block that is being partially written.
2114 */
2115 if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) {
2116 for (i=disks; i--;) {
2117 dev = &sh->dev[i];
2118 if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
2119 (dev->toread ||
2120 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2121 syncing ||
2122 (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) ||
2123 (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write))
2124 )
2125 ) {
2126 /* we would like to get this block, possibly
2127 * by computing it, but we might not be able to
2128 */
2129 if (uptodate == disks-1) {
2130 PRINTK("Computing stripe %llu block %d\n",
2131 (unsigned long long)sh->sector, i);
2132 compute_block_1(sh, i, 0);
2133 uptodate++;
2134 } else if ( uptodate == disks-2 && failed >= 2 ) {
2135 /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */
2136 int other;
2137 for (other=disks; other--;) {
2138 if ( other == i )
2139 continue;
2140 if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) )
2141 break;
2142 }
2143 BUG_ON(other < 0);
2144 PRINTK("Computing stripe %llu blocks %d,%d\n",
2145 (unsigned long long)sh->sector, i, other);
2146 compute_block_2(sh, i, other);
2147 uptodate += 2;
2148 } else if (test_bit(R5_Insync, &dev->flags)) {
2149 set_bit(R5_LOCKED, &dev->flags);
2150 set_bit(R5_Wantread, &dev->flags);
NeilBrown16a53ec2006-06-26 00:27:38 -07002151 locked++;
2152 PRINTK("Reading block %d (sync=%d)\n",
2153 i, syncing);
2154 }
2155 }
2156 }
2157 set_bit(STRIPE_HANDLE, &sh->state);
2158 }
2159
2160 /* now to consider writing and what else, if anything should be read */
2161 if (to_write) {
2162 int rcw=0, must_compute=0;
2163 for (i=disks ; i--;) {
2164 dev = &sh->dev[i];
2165 /* Would I have to read this buffer for reconstruct_write */
2166 if (!test_bit(R5_OVERWRITE, &dev->flags)
2167 && i != pd_idx && i != qd_idx
2168 && (!test_bit(R5_LOCKED, &dev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07002169 ) &&
2170 !test_bit(R5_UPTODATE, &dev->flags)) {
2171 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2172 else {
2173 PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags);
2174 must_compute++;
2175 }
2176 }
2177 }
2178 PRINTK("for sector %llu, rcw=%d, must_compute=%d\n",
2179 (unsigned long long)sh->sector, rcw, must_compute);
2180 set_bit(STRIPE_HANDLE, &sh->state);
2181
2182 if (rcw > 0)
2183 /* want reconstruct write, but need to get some data */
2184 for (i=disks; i--;) {
2185 dev = &sh->dev[i];
2186 if (!test_bit(R5_OVERWRITE, &dev->flags)
2187 && !(failed == 0 && (i == pd_idx || i == qd_idx))
2188 && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
2189 test_bit(R5_Insync, &dev->flags)) {
2190 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
2191 {
2192 PRINTK("Read_old stripe %llu block %d for Reconstruct\n",
2193 (unsigned long long)sh->sector, i);
2194 set_bit(R5_LOCKED, &dev->flags);
2195 set_bit(R5_Wantread, &dev->flags);
2196 locked++;
2197 } else {
2198 PRINTK("Request delayed stripe %llu block %d for Reconstruct\n",
2199 (unsigned long long)sh->sector, i);
2200 set_bit(STRIPE_DELAYED, &sh->state);
2201 set_bit(STRIPE_HANDLE, &sh->state);
2202 }
2203 }
2204 }
2205 /* now if nothing is locked, and if we have enough data, we can start a write request */
2206 if (locked == 0 && rcw == 0 &&
2207 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2208 if ( must_compute > 0 ) {
2209 /* We have failed blocks and need to compute them */
2210 switch ( failed ) {
2211 case 0: BUG();
2212 case 1: compute_block_1(sh, failed_num[0], 0); break;
2213 case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break;
2214 default: BUG(); /* This request should have been failed? */
2215 }
2216 }
2217
2218 PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector);
2219 compute_parity6(sh, RECONSTRUCT_WRITE);
2220 /* now every locked buffer is ready to be written */
2221 for (i=disks; i--;)
2222 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
2223 PRINTK("Writing stripe %llu block %d\n",
2224 (unsigned long long)sh->sector, i);
2225 locked++;
2226 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2227 }
2228 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2229 set_bit(STRIPE_INSYNC, &sh->state);
2230
2231 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2232 atomic_dec(&conf->preread_active_stripes);
2233 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
2234 md_wakeup_thread(conf->mddev->thread);
2235 }
2236 }
2237 }
2238
2239 /* maybe we need to check and possibly fix the parity for this stripe
2240 * Any reads will already have been scheduled, so we just see if enough data
2241 * is available
2242 */
2243 if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) {
2244 int update_p = 0, update_q = 0;
2245 struct r5dev *dev;
2246
2247 set_bit(STRIPE_HANDLE, &sh->state);
2248
2249 BUG_ON(failed>2);
2250 BUG_ON(uptodate < disks);
2251 /* Want to check and possibly repair P and Q.
2252 * However there could be one 'failed' device, in which
2253 * case we can only check one of them, possibly using the
2254 * other to generate missing data
2255 */
2256
2257 /* If !tmp_page, we cannot do the calculations,
2258 * but as we have set STRIPE_HANDLE, we will soon be called
2259 * by stripe_handle with a tmp_page - just wait until then.
2260 */
2261 if (tmp_page) {
2262 if (failed == q_failed) {
2263 /* The only possible failed device holds 'Q', so it makes
2264 * sense to check P (If anything else were failed, we would
2265 * have used P to recreate it).
2266 */
2267 compute_block_1(sh, pd_idx, 1);
2268 if (!page_is_zero(sh->dev[pd_idx].page)) {
2269 compute_block_1(sh,pd_idx,0);
2270 update_p = 1;
2271 }
2272 }
2273 if (!q_failed && failed < 2) {
2274 /* q is not failed, and we didn't use it to generate
2275 * anything, so it makes sense to check it
2276 */
2277 memcpy(page_address(tmp_page),
2278 page_address(sh->dev[qd_idx].page),
2279 STRIPE_SIZE);
2280 compute_parity6(sh, UPDATE_PARITY);
2281 if (memcmp(page_address(tmp_page),
2282 page_address(sh->dev[qd_idx].page),
2283 STRIPE_SIZE)!= 0) {
2284 clear_bit(STRIPE_INSYNC, &sh->state);
2285 update_q = 1;
2286 }
2287 }
2288 if (update_p || update_q) {
2289 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2290 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2291 /* don't try to repair!! */
2292 update_p = update_q = 0;
2293 }
2294
2295 /* now write out any block on a failed drive,
2296 * or P or Q if they need it
2297 */
2298
2299 if (failed == 2) {
2300 dev = &sh->dev[failed_num[1]];
2301 locked++;
2302 set_bit(R5_LOCKED, &dev->flags);
2303 set_bit(R5_Wantwrite, &dev->flags);
2304 }
2305 if (failed >= 1) {
2306 dev = &sh->dev[failed_num[0]];
2307 locked++;
2308 set_bit(R5_LOCKED, &dev->flags);
2309 set_bit(R5_Wantwrite, &dev->flags);
2310 }
2311
2312 if (update_p) {
2313 dev = &sh->dev[pd_idx];
2314 locked ++;
2315 set_bit(R5_LOCKED, &dev->flags);
2316 set_bit(R5_Wantwrite, &dev->flags);
2317 }
2318 if (update_q) {
2319 dev = &sh->dev[qd_idx];
2320 locked++;
2321 set_bit(R5_LOCKED, &dev->flags);
2322 set_bit(R5_Wantwrite, &dev->flags);
2323 }
2324 clear_bit(STRIPE_DEGRADED, &sh->state);
2325
2326 set_bit(STRIPE_INSYNC, &sh->state);
2327 }
2328 }
2329
2330 if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
2331 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2332 clear_bit(STRIPE_SYNCING, &sh->state);
2333 }
2334
2335 /* If the failed drives are just a ReadError, then we might need
2336 * to progress the repair/check process
2337 */
2338 if (failed <= 2 && ! conf->mddev->ro)
2339 for (i=0; i<failed;i++) {
2340 dev = &sh->dev[failed_num[i]];
2341 if (test_bit(R5_ReadError, &dev->flags)
2342 && !test_bit(R5_LOCKED, &dev->flags)
2343 && test_bit(R5_UPTODATE, &dev->flags)
2344 ) {
2345 if (!test_bit(R5_ReWrite, &dev->flags)) {
2346 set_bit(R5_Wantwrite, &dev->flags);
2347 set_bit(R5_ReWrite, &dev->flags);
2348 set_bit(R5_LOCKED, &dev->flags);
2349 } else {
2350 /* let's read it back */
2351 set_bit(R5_Wantread, &dev->flags);
2352 set_bit(R5_LOCKED, &dev->flags);
2353 }
2354 }
2355 }
2356 spin_unlock(&sh->lock);
2357
2358 while ((bi=return_bi)) {
2359 int bytes = bi->bi_size;
2360
2361 return_bi = bi->bi_next;
2362 bi->bi_next = NULL;
2363 bi->bi_size = 0;
NeilBrownc2b00852006-12-10 02:20:51 -08002364 bi->bi_end_io(bi, bytes,
2365 test_bit(BIO_UPTODATE, &bi->bi_flags)
2366 ? 0 : -EIO);
NeilBrown16a53ec2006-06-26 00:27:38 -07002367 }
2368 for (i=disks; i-- ;) {
2369 int rw;
2370 struct bio *bi;
2371 mdk_rdev_t *rdev;
2372 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08002373 rw = WRITE;
NeilBrown16a53ec2006-06-26 00:27:38 -07002374 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08002375 rw = READ;
NeilBrown16a53ec2006-06-26 00:27:38 -07002376 else
2377 continue;
2378
2379 bi = &sh->dev[i].req;
2380
2381 bi->bi_rw = rw;
NeilBrown802ba062006-12-13 00:34:13 -08002382 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07002383 bi->bi_end_io = raid5_end_write_request;
2384 else
2385 bi->bi_end_io = raid5_end_read_request;
2386
2387 rcu_read_lock();
2388 rdev = rcu_dereference(conf->disks[i].rdev);
2389 if (rdev && test_bit(Faulty, &rdev->flags))
2390 rdev = NULL;
2391 if (rdev)
2392 atomic_inc(&rdev->nr_pending);
2393 rcu_read_unlock();
2394
2395 if (rdev) {
2396 if (syncing)
2397 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
2398
2399 bi->bi_bdev = rdev->bdev;
2400 PRINTK("for %llu schedule op %ld on disc %d\n",
2401 (unsigned long long)sh->sector, bi->bi_rw, i);
2402 atomic_inc(&sh->count);
2403 bi->bi_sector = sh->sector + rdev->data_offset;
2404 bi->bi_flags = 1 << BIO_UPTODATE;
2405 bi->bi_vcnt = 1;
2406 bi->bi_max_vecs = 1;
2407 bi->bi_idx = 0;
2408 bi->bi_io_vec = &sh->dev[i].vec;
2409 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
2410 bi->bi_io_vec[0].bv_offset = 0;
2411 bi->bi_size = STRIPE_SIZE;
2412 bi->bi_next = NULL;
2413 if (rw == WRITE &&
2414 test_bit(R5_ReWrite, &sh->dev[i].flags))
2415 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2416 generic_make_request(bi);
2417 } else {
NeilBrown802ba062006-12-13 00:34:13 -08002418 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07002419 set_bit(STRIPE_DEGRADED, &sh->state);
2420 PRINTK("skip op %ld on disc %d for sector %llu\n",
2421 bi->bi_rw, i, (unsigned long long)sh->sector);
2422 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2423 set_bit(STRIPE_HANDLE, &sh->state);
2424 }
2425 }
2426}
2427
2428static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
2429{
2430 if (sh->raid_conf->level == 6)
2431 handle_stripe6(sh, tmp_page);
2432 else
2433 handle_stripe5(sh);
2434}
2435
2436
2437
Arjan van de Ven858119e2006-01-14 13:20:43 -08002438static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002439{
2440 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
2441 while (!list_empty(&conf->delayed_list)) {
2442 struct list_head *l = conf->delayed_list.next;
2443 struct stripe_head *sh;
2444 sh = list_entry(l, struct stripe_head, lru);
2445 list_del_init(l);
2446 clear_bit(STRIPE_DELAYED, &sh->state);
2447 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
2448 atomic_inc(&conf->preread_active_stripes);
2449 list_add_tail(&sh->lru, &conf->handle_list);
2450 }
2451 }
2452}
2453
Arjan van de Ven858119e2006-01-14 13:20:43 -08002454static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07002455{
2456 /* device_lock is held */
2457 struct list_head head;
2458 list_add(&head, &conf->bitmap_list);
2459 list_del_init(&conf->bitmap_list);
2460 while (!list_empty(&head)) {
2461 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
2462 list_del_init(&sh->lru);
2463 atomic_inc(&sh->count);
2464 __release_stripe(conf, sh);
2465 }
2466}
2467
Linus Torvalds1da177e2005-04-16 15:20:36 -07002468static void unplug_slaves(mddev_t *mddev)
2469{
2470 raid5_conf_t *conf = mddev_to_conf(mddev);
2471 int i;
2472
2473 rcu_read_lock();
2474 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08002475 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08002476 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002477 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
2478
2479 atomic_inc(&rdev->nr_pending);
2480 rcu_read_unlock();
2481
2482 if (r_queue->unplug_fn)
2483 r_queue->unplug_fn(r_queue);
2484
2485 rdev_dec_pending(rdev, mddev);
2486 rcu_read_lock();
2487 }
2488 }
2489 rcu_read_unlock();
2490}
2491
2492static void raid5_unplug_device(request_queue_t *q)
2493{
2494 mddev_t *mddev = q->queuedata;
2495 raid5_conf_t *conf = mddev_to_conf(mddev);
2496 unsigned long flags;
2497
2498 spin_lock_irqsave(&conf->device_lock, flags);
2499
NeilBrown72626682005-09-09 16:23:54 -07002500 if (blk_remove_plug(q)) {
2501 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002502 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07002503 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002504 md_wakeup_thread(mddev->thread);
2505
2506 spin_unlock_irqrestore(&conf->device_lock, flags);
2507
2508 unplug_slaves(mddev);
2509}
2510
2511static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk,
2512 sector_t *error_sector)
2513{
2514 mddev_t *mddev = q->queuedata;
2515 raid5_conf_t *conf = mddev_to_conf(mddev);
2516 int i, ret = 0;
2517
2518 rcu_read_lock();
2519 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08002520 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08002521 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002522 struct block_device *bdev = rdev->bdev;
2523 request_queue_t *r_queue = bdev_get_queue(bdev);
2524
2525 if (!r_queue->issue_flush_fn)
2526 ret = -EOPNOTSUPP;
2527 else {
2528 atomic_inc(&rdev->nr_pending);
2529 rcu_read_unlock();
2530 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
2531 error_sector);
2532 rdev_dec_pending(rdev, mddev);
2533 rcu_read_lock();
2534 }
2535 }
2536 }
2537 rcu_read_unlock();
2538 return ret;
2539}
2540
NeilBrownf022b2f2006-10-03 01:15:56 -07002541static int raid5_congested(void *data, int bits)
2542{
2543 mddev_t *mddev = data;
2544 raid5_conf_t *conf = mddev_to_conf(mddev);
2545
2546 /* No difference between reads and writes. Just check
2547 * how busy the stripe_cache is
2548 */
2549 if (conf->inactive_blocked)
2550 return 1;
2551 if (conf->quiesce)
2552 return 1;
2553 if (list_empty_careful(&conf->inactive_list))
2554 return 1;
2555
2556 return 0;
2557}
2558
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08002559/* We want read requests to align with chunks where possible,
2560 * but write requests don't need to.
2561 */
2562static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
2563{
2564 mddev_t *mddev = q->queuedata;
2565 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
2566 int max;
2567 unsigned int chunk_sectors = mddev->chunk_size >> 9;
2568 unsigned int bio_sectors = bio->bi_size >> 9;
2569
NeilBrown802ba062006-12-13 00:34:13 -08002570 if (bio_data_dir(bio) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08002571 return biovec->bv_len; /* always allow writes to be mergeable */
2572
2573 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
2574 if (max < 0) max = 0;
2575 if (max <= biovec->bv_len && bio_sectors == 0)
2576 return biovec->bv_len;
2577 else
2578 return max;
2579}
2580
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002581
2582static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
2583{
2584 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
2585 unsigned int chunk_sectors = mddev->chunk_size >> 9;
2586 unsigned int bio_sectors = bio->bi_size >> 9;
2587
2588 return chunk_sectors >=
2589 ((sector & (chunk_sectors - 1)) + bio_sectors);
2590}
2591
2592/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002593 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
2594 * later sampled by raid5d.
2595 */
2596static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
2597{
2598 unsigned long flags;
2599
2600 spin_lock_irqsave(&conf->device_lock, flags);
2601
2602 bi->bi_next = conf->retry_read_aligned_list;
2603 conf->retry_read_aligned_list = bi;
2604
2605 spin_unlock_irqrestore(&conf->device_lock, flags);
2606 md_wakeup_thread(conf->mddev->thread);
2607}
2608
2609
2610static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
2611{
2612 struct bio *bi;
2613
2614 bi = conf->retry_read_aligned;
2615 if (bi) {
2616 conf->retry_read_aligned = NULL;
2617 return bi;
2618 }
2619 bi = conf->retry_read_aligned_list;
2620 if(bi) {
2621 conf->retry_read_aligned = bi->bi_next;
2622 bi->bi_next = NULL;
2623 bi->bi_phys_segments = 1; /* biased count of active stripes */
2624 bi->bi_hw_segments = 0; /* count of processed stripes */
2625 }
2626
2627 return bi;
2628}
2629
2630
2631/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002632 * The "raid5_align_endio" should check if the read succeeded and if it
2633 * did, call bio_endio on the original bio (having bio_put the new bio
2634 * first).
2635 * If the read failed..
2636 */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002637static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002638{
2639 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002640 mddev_t *mddev;
2641 raid5_conf_t *conf;
2642 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
2643 mdk_rdev_t *rdev;
2644
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002645 if (bi->bi_size)
2646 return 1;
2647 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002648
2649 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
2650 conf = mddev_to_conf(mddev);
2651 rdev = (void*)raid_bi->bi_next;
2652 raid_bi->bi_next = NULL;
2653
2654 rdev_dec_pending(rdev, conf->mddev);
2655
2656 if (!error && uptodate) {
2657 bio_endio(raid_bi, bytes, 0);
2658 if (atomic_dec_and_test(&conf->active_aligned_reads))
2659 wake_up(&conf->wait_for_stripe);
2660 return 0;
2661 }
2662
2663
2664 PRINTK("raid5_align_endio : io error...handing IO for a retry\n");
2665
2666 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002667 return 0;
2668}
2669
2670static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
2671{
2672 mddev_t *mddev = q->queuedata;
2673 raid5_conf_t *conf = mddev_to_conf(mddev);
2674 const unsigned int raid_disks = conf->raid_disks;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002675 const unsigned int data_disks = raid_disks - conf->max_degraded;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002676 unsigned int dd_idx, pd_idx;
2677 struct bio* align_bi;
2678 mdk_rdev_t *rdev;
2679
2680 if (!in_chunk_boundary(mddev, raid_bio)) {
2681 printk("chunk_aligned_read : non aligned\n");
2682 return 0;
2683 }
2684 /*
2685 * use bio_clone to make a copy of the bio
2686 */
2687 align_bi = bio_clone(raid_bio, GFP_NOIO);
2688 if (!align_bi)
2689 return 0;
2690 /*
2691 * set bi_end_io to a new function, and set bi_private to the
2692 * original bio.
2693 */
2694 align_bi->bi_end_io = raid5_align_endio;
2695 align_bi->bi_private = raid_bio;
2696 /*
2697 * compute position
2698 */
2699 align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector,
2700 raid_disks,
2701 data_disks,
2702 &dd_idx,
2703 &pd_idx,
2704 conf);
2705
2706 rcu_read_lock();
2707 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
2708 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002709 atomic_inc(&rdev->nr_pending);
2710 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002711 raid_bio->bi_next = (void*)rdev;
2712 align_bi->bi_bdev = rdev->bdev;
2713 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
2714 align_bi->bi_sector += rdev->data_offset;
2715
2716 spin_lock_irq(&conf->device_lock);
2717 wait_event_lock_irq(conf->wait_for_stripe,
2718 conf->quiesce == 0,
2719 conf->device_lock, /* nothing */);
2720 atomic_inc(&conf->active_aligned_reads);
2721 spin_unlock_irq(&conf->device_lock);
2722
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002723 generic_make_request(align_bi);
2724 return 1;
2725 } else {
2726 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08002727 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08002728 return 0;
2729 }
2730}
2731
2732
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002733static int make_request(request_queue_t *q, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002734{
2735 mddev_t *mddev = q->queuedata;
2736 raid5_conf_t *conf = mddev_to_conf(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002737 unsigned int dd_idx, pd_idx;
2738 sector_t new_sector;
2739 sector_t logical_sector, last_sector;
2740 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01002741 const int rw = bio_data_dir(bi);
NeilBrownf6344752006-03-27 01:18:17 -08002742 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743
NeilBrowne5dcdd82005-09-09 16:23:41 -07002744 if (unlikely(bio_barrier(bi))) {
2745 bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
2746 return 0;
2747 }
2748
NeilBrown3d310eb2005-06-21 17:17:26 -07002749 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07002750
Jens Axboea3623572005-11-01 09:26:16 +01002751 disk_stat_inc(mddev->gendisk, ios[rw]);
2752 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002753
NeilBrown802ba062006-12-13 00:34:13 -08002754 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08002755 mddev->reshape_position == MaxSector &&
2756 chunk_aligned_read(q,bi))
2757 return 0;
2758
Linus Torvalds1da177e2005-04-16 15:20:36 -07002759 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
2760 last_sector = bi->bi_sector + (bi->bi_size>>9);
2761 bi->bi_next = NULL;
2762 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07002763
Linus Torvalds1da177e2005-04-16 15:20:36 -07002764 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
2765 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07002766 int disks, data_disks;
NeilBrownb578d552006-03-27 01:18:12 -08002767
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002768 retry:
NeilBrownb578d552006-03-27 01:18:12 -08002769 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002770 if (likely(conf->expand_progress == MaxSector))
2771 disks = conf->raid_disks;
2772 else {
NeilBrowndf8e7f72006-03-27 01:18:15 -08002773 /* spinlock is needed as expand_progress may be
2774 * 64bit on a 32bit platform, and so it might be
2775 * possible to see a half-updated value
2776 * Ofcourse expand_progress could change after
2777 * the lock is dropped, so once we get a reference
2778 * to the stripe that we think it is, we will have
2779 * to check again.
2780 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002781 spin_lock_irq(&conf->device_lock);
2782 disks = conf->raid_disks;
2783 if (logical_sector >= conf->expand_progress)
2784 disks = conf->previous_raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08002785 else {
2786 if (logical_sector >= conf->expand_lo) {
2787 spin_unlock_irq(&conf->device_lock);
2788 schedule();
2789 goto retry;
2790 }
2791 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002792 spin_unlock_irq(&conf->device_lock);
2793 }
NeilBrown16a53ec2006-06-26 00:27:38 -07002794 data_disks = disks - conf->max_degraded;
2795
2796 new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002797 &dd_idx, &pd_idx, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002798 PRINTK("raid5: make_request, sector %llu logical %llu\n",
2799 (unsigned long long)new_sector,
2800 (unsigned long long)logical_sector);
2801
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002802 sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002803 if (sh) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002804 if (unlikely(conf->expand_progress != MaxSector)) {
2805 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08002806 * stripe, so we must do the range check again.
2807 * Expansion could still move past after this
2808 * test, but as we are holding a reference to
2809 * 'sh', we know that if that happens,
2810 * STRIPE_EXPANDING will get set and the expansion
2811 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002812 */
2813 int must_retry = 0;
2814 spin_lock_irq(&conf->device_lock);
2815 if (logical_sector < conf->expand_progress &&
2816 disks == conf->previous_raid_disks)
2817 /* mismatch, need to try again */
2818 must_retry = 1;
2819 spin_unlock_irq(&conf->device_lock);
2820 if (must_retry) {
2821 release_stripe(sh);
2822 goto retry;
2823 }
2824 }
NeilBrowne464eaf2006-03-27 01:18:14 -08002825 /* FIXME what if we get a false positive because these
2826 * are being updated.
2827 */
2828 if (logical_sector >= mddev->suspend_lo &&
2829 logical_sector < mddev->suspend_hi) {
2830 release_stripe(sh);
2831 schedule();
2832 goto retry;
2833 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08002834
2835 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
2836 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
2837 /* Stripe is busy expanding or
2838 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07002839 * and wait a while
2840 */
2841 raid5_unplug_device(mddev->queue);
2842 release_stripe(sh);
2843 schedule();
2844 goto retry;
2845 }
2846 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown16a53ec2006-06-26 00:27:38 -07002847 handle_stripe(sh, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002848 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002849 } else {
2850 /* cannot get stripe for read-ahead, just give-up */
2851 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2852 finish_wait(&conf->wait_for_overlap, &w);
2853 break;
2854 }
2855
2856 }
2857 spin_lock_irq(&conf->device_lock);
NeilBrownf6344752006-03-27 01:18:17 -08002858 remaining = --bi->bi_phys_segments;
2859 spin_unlock_irq(&conf->device_lock);
2860 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002861 int bytes = bi->bi_size;
2862
NeilBrown16a53ec2006-06-26 00:27:38 -07002863 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07002864 md_write_end(mddev);
2865 bi->bi_size = 0;
NeilBrownc2b00852006-12-10 02:20:51 -08002866 bi->bi_end_io(bi, bytes,
2867 test_bit(BIO_UPTODATE, &bi->bi_flags)
2868 ? 0 : -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002869 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002870 return 0;
2871}
2872
NeilBrown52c03292006-06-26 00:27:43 -07002873static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002874{
NeilBrown52c03292006-06-26 00:27:43 -07002875 /* reshaping is quite different to recovery/resync so it is
2876 * handled quite separately ... here.
2877 *
2878 * On each call to sync_request, we gather one chunk worth of
2879 * destination stripes and flag them as expanding.
2880 * Then we find all the source stripes and request reads.
2881 * As the reads complete, handle_stripe will copy the data
2882 * into the destination stripe and release that stripe.
2883 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002884 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
2885 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08002886 int pd_idx;
2887 sector_t first_sector, last_sector;
NeilBrown52c03292006-06-26 00:27:43 -07002888 int raid_disks;
2889 int data_disks;
2890 int i;
2891 int dd_idx;
2892 sector_t writepos, safepos, gap;
2893
2894 if (sector_nr == 0 &&
2895 conf->expand_progress != 0) {
2896 /* restarting in the middle, skip the initial sectors */
2897 sector_nr = conf->expand_progress;
2898 sector_div(sector_nr, conf->raid_disks-1);
2899 *skipped = 1;
2900 return sector_nr;
2901 }
2902
2903 /* we update the metadata when there is more than 3Meg
2904 * in the block range (that is rather arbitrary, should
2905 * probably be time based) or when the data about to be
2906 * copied would over-write the source of the data at
2907 * the front of the range.
2908 * i.e. one new_stripe forward from expand_progress new_maps
2909 * to after where expand_lo old_maps to
2910 */
2911 writepos = conf->expand_progress +
2912 conf->chunk_size/512*(conf->raid_disks-1);
2913 sector_div(writepos, conf->raid_disks-1);
2914 safepos = conf->expand_lo;
2915 sector_div(safepos, conf->previous_raid_disks-1);
2916 gap = conf->expand_progress - conf->expand_lo;
2917
2918 if (writepos >= safepos ||
2919 gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) {
2920 /* Cannot proceed until we've updated the superblock... */
2921 wait_event(conf->wait_for_overlap,
2922 atomic_read(&conf->reshape_stripes)==0);
2923 mddev->reshape_position = conf->expand_progress;
NeilBrown850b2b42006-10-03 01:15:46 -07002924 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07002925 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07002926 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07002927 kthread_should_stop());
2928 spin_lock_irq(&conf->device_lock);
2929 conf->expand_lo = mddev->reshape_position;
2930 spin_unlock_irq(&conf->device_lock);
2931 wake_up(&conf->wait_for_overlap);
2932 }
2933
2934 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
2935 int j;
2936 int skipped = 0;
2937 pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
2938 sh = get_active_stripe(conf, sector_nr+i,
2939 conf->raid_disks, pd_idx, 0);
2940 set_bit(STRIPE_EXPANDING, &sh->state);
2941 atomic_inc(&conf->reshape_stripes);
2942 /* If any of this stripe is beyond the end of the old
2943 * array, then we need to zero those blocks
2944 */
2945 for (j=sh->disks; j--;) {
2946 sector_t s;
2947 if (j == sh->pd_idx)
2948 continue;
2949 s = compute_blocknr(sh, j);
2950 if (s < (mddev->array_size<<1)) {
2951 skipped = 1;
2952 continue;
2953 }
2954 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
2955 set_bit(R5_Expanded, &sh->dev[j].flags);
2956 set_bit(R5_UPTODATE, &sh->dev[j].flags);
2957 }
2958 if (!skipped) {
2959 set_bit(STRIPE_EXPAND_READY, &sh->state);
2960 set_bit(STRIPE_HANDLE, &sh->state);
2961 }
2962 release_stripe(sh);
2963 }
2964 spin_lock_irq(&conf->device_lock);
2965 conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1);
2966 spin_unlock_irq(&conf->device_lock);
2967 /* Ok, those stripe are ready. We can start scheduling
2968 * reads on the source stripes.
2969 * The source stripes are determined by mapping the first and last
2970 * block on the destination stripes.
2971 */
2972 raid_disks = conf->previous_raid_disks;
2973 data_disks = raid_disks - 1;
2974 first_sector =
2975 raid5_compute_sector(sector_nr*(conf->raid_disks-1),
2976 raid_disks, data_disks,
2977 &dd_idx, &pd_idx, conf);
2978 last_sector =
2979 raid5_compute_sector((sector_nr+conf->chunk_size/512)
2980 *(conf->raid_disks-1) -1,
2981 raid_disks, data_disks,
2982 &dd_idx, &pd_idx, conf);
2983 if (last_sector >= (mddev->size<<1))
2984 last_sector = (mddev->size<<1)-1;
2985 while (first_sector <= last_sector) {
2986 pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks);
2987 sh = get_active_stripe(conf, first_sector,
2988 conf->previous_raid_disks, pd_idx, 0);
2989 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2990 set_bit(STRIPE_HANDLE, &sh->state);
2991 release_stripe(sh);
2992 first_sector += STRIPE_SECTORS;
2993 }
2994 return conf->chunk_size>>9;
2995}
2996
2997/* FIXME go_faster isn't used */
2998static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
2999{
3000 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3001 struct stripe_head *sh;
3002 int pd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003 int raid_disks = conf->raid_disks;
NeilBrown72626682005-09-09 16:23:54 -07003004 sector_t max_sector = mddev->size << 1;
3005 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07003006 int still_degraded = 0;
3007 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003008
NeilBrown72626682005-09-09 16:23:54 -07003009 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003010 /* just being told to finish up .. nothing much to do */
3011 unplug_slaves(mddev);
NeilBrown29269552006-03-27 01:18:10 -08003012 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3013 end_reshape(conf);
3014 return 0;
3015 }
NeilBrown72626682005-09-09 16:23:54 -07003016
3017 if (mddev->curr_resync < max_sector) /* aborted */
3018 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3019 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003020 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07003021 conf->fullsync = 0;
3022 bitmap_close_sync(mddev->bitmap);
3023
Linus Torvalds1da177e2005-04-16 15:20:36 -07003024 return 0;
3025 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08003026
NeilBrown52c03292006-06-26 00:27:43 -07003027 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3028 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08003029
NeilBrown16a53ec2006-06-26 00:27:38 -07003030 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07003031 * to resync, then assert that we are finished, because there is
3032 * nothing we can do.
3033 */
NeilBrown3285edf2006-06-26 00:27:55 -07003034 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07003035 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
NeilBrown57afd892005-06-21 17:17:13 -07003036 sector_t rv = (mddev->size << 1) - sector_nr;
3037 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003038 return rv;
3039 }
NeilBrown72626682005-09-09 16:23:54 -07003040 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08003041 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07003042 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3043 /* we can skip this block, and probably more */
3044 sync_blocks /= STRIPE_SECTORS;
3045 *skipped = 1;
3046 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3047 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003048
NeilBrownccfcc3c2006-03-27 01:18:09 -08003049 pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003050 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003051 if (sh == NULL) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003052 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003053 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07003054 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07003055 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08003056 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003057 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003058 /* Need to check if array will still be degraded after recovery/resync
3059 * We don't need to check the 'failed' flag as when that gets set,
3060 * recovery aborts.
3061 */
3062 for (i=0; i<mddev->raid_disks; i++)
3063 if (conf->disks[i].rdev == NULL)
3064 still_degraded = 1;
3065
3066 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
3067
3068 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003069 set_bit(STRIPE_SYNCING, &sh->state);
3070 clear_bit(STRIPE_INSYNC, &sh->state);
3071 spin_unlock(&sh->lock);
3072
NeilBrown16a53ec2006-06-26 00:27:38 -07003073 handle_stripe(sh, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003074 release_stripe(sh);
3075
3076 return STRIPE_SECTORS;
3077}
3078
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003079static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
3080{
3081 /* We may not be able to submit a whole bio at once as there
3082 * may not be enough stripe_heads available.
3083 * We cannot pre-allocate enough stripe_heads as we may need
3084 * more than exist in the cache (if we allow ever large chunks).
3085 * So we do one stripe head at a time and record in
3086 * ->bi_hw_segments how many have been done.
3087 *
3088 * We *know* that this entire raid_bio is in one chunk, so
3089 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3090 */
3091 struct stripe_head *sh;
3092 int dd_idx, pd_idx;
3093 sector_t sector, logical_sector, last_sector;
3094 int scnt = 0;
3095 int remaining;
3096 int handled = 0;
3097
3098 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3099 sector = raid5_compute_sector( logical_sector,
3100 conf->raid_disks,
3101 conf->raid_disks - conf->max_degraded,
3102 &dd_idx,
3103 &pd_idx,
3104 conf);
3105 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
3106
3107 for (; logical_sector < last_sector;
3108 logical_sector += STRIPE_SECTORS, scnt++) {
3109
3110 if (scnt < raid_bio->bi_hw_segments)
3111 /* already done this stripe */
3112 continue;
3113
3114 sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1);
3115
3116 if (!sh) {
3117 /* failed to get a stripe - must wait */
3118 raid_bio->bi_hw_segments = scnt;
3119 conf->retry_read_aligned = raid_bio;
3120 return handled;
3121 }
3122
3123 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
3124 add_stripe_bio(sh, raid_bio, dd_idx, 0);
3125 handle_stripe(sh, NULL);
3126 release_stripe(sh);
3127 handled++;
3128 }
3129 spin_lock_irq(&conf->device_lock);
3130 remaining = --raid_bio->bi_phys_segments;
3131 spin_unlock_irq(&conf->device_lock);
3132 if (remaining == 0) {
3133 int bytes = raid_bio->bi_size;
3134
3135 raid_bio->bi_size = 0;
NeilBrownc2b00852006-12-10 02:20:51 -08003136 raid_bio->bi_end_io(raid_bio, bytes,
3137 test_bit(BIO_UPTODATE, &raid_bio->bi_flags)
3138 ? 0 : -EIO);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003139 }
3140 if (atomic_dec_and_test(&conf->active_aligned_reads))
3141 wake_up(&conf->wait_for_stripe);
3142 return handled;
3143}
3144
3145
3146
Linus Torvalds1da177e2005-04-16 15:20:36 -07003147/*
3148 * This is our raid5 kernel thread.
3149 *
3150 * We scan the hash table for stripes which can be handled now.
3151 * During the scan, completed stripes are saved for us by the interrupt
3152 * handler, so that they will not have to wait for our next wakeup.
3153 */
3154static void raid5d (mddev_t *mddev)
3155{
3156 struct stripe_head *sh;
3157 raid5_conf_t *conf = mddev_to_conf(mddev);
3158 int handled;
3159
3160 PRINTK("+++ raid5d active\n");
3161
3162 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003163
3164 handled = 0;
3165 spin_lock_irq(&conf->device_lock);
3166 while (1) {
3167 struct list_head *first;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003168 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169
NeilBrownae3c20c2006-07-10 04:44:17 -07003170 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07003171 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08003172 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07003173 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08003174 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07003175 conf->seq_write = seq;
3176 activate_bit_delay(conf);
3177 }
3178
Linus Torvalds1da177e2005-04-16 15:20:36 -07003179 if (list_empty(&conf->handle_list) &&
3180 atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD &&
3181 !blk_queue_plugged(mddev->queue) &&
3182 !list_empty(&conf->delayed_list))
3183 raid5_activate_delayed(conf);
3184
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003185 while ((bio = remove_bio_from_retry(conf))) {
3186 int ok;
3187 spin_unlock_irq(&conf->device_lock);
3188 ok = retry_aligned_read(conf, bio);
3189 spin_lock_irq(&conf->device_lock);
3190 if (!ok)
3191 break;
3192 handled++;
3193 }
3194
Linus Torvalds1da177e2005-04-16 15:20:36 -07003195 if (list_empty(&conf->handle_list))
3196 break;
3197
3198 first = conf->handle_list.next;
3199 sh = list_entry(first, struct stripe_head, lru);
3200
3201 list_del_init(first);
3202 atomic_inc(&sh->count);
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02003203 BUG_ON(atomic_read(&sh->count)!= 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003204 spin_unlock_irq(&conf->device_lock);
3205
3206 handled++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003207 handle_stripe(sh, conf->spare_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003208 release_stripe(sh);
3209
3210 spin_lock_irq(&conf->device_lock);
3211 }
3212 PRINTK("%d stripes handled\n", handled);
3213
3214 spin_unlock_irq(&conf->device_lock);
3215
3216 unplug_slaves(mddev);
3217
3218 PRINTK("--- raid5d inactive\n");
3219}
3220
NeilBrown3f294f42005-11-08 21:39:25 -08003221static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08003222raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08003223{
NeilBrown007583c2005-11-08 21:39:30 -08003224 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08003225 if (conf)
3226 return sprintf(page, "%d\n", conf->max_nr_stripes);
3227 else
3228 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08003229}
3230
3231static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08003232raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08003233{
NeilBrown007583c2005-11-08 21:39:30 -08003234 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown3f294f42005-11-08 21:39:25 -08003235 char *end;
3236 int new;
3237 if (len >= PAGE_SIZE)
3238 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08003239 if (!conf)
3240 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08003241
3242 new = simple_strtoul(page, &end, 10);
3243 if (!*page || (*end && *end != '\n') )
3244 return -EINVAL;
3245 if (new <= 16 || new > 32768)
3246 return -EINVAL;
3247 while (new < conf->max_nr_stripes) {
3248 if (drop_one_stripe(conf))
3249 conf->max_nr_stripes--;
3250 else
3251 break;
3252 }
3253 while (new > conf->max_nr_stripes) {
3254 if (grow_one_stripe(conf))
3255 conf->max_nr_stripes++;
3256 else break;
3257 }
3258 return len;
3259}
NeilBrown007583c2005-11-08 21:39:30 -08003260
NeilBrown96de1e62005-11-08 21:39:39 -08003261static struct md_sysfs_entry
3262raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
3263 raid5_show_stripe_cache_size,
3264 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08003265
3266static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08003267stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08003268{
NeilBrown007583c2005-11-08 21:39:30 -08003269 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08003270 if (conf)
3271 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
3272 else
3273 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08003274}
3275
NeilBrown96de1e62005-11-08 21:39:39 -08003276static struct md_sysfs_entry
3277raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08003278
NeilBrown007583c2005-11-08 21:39:30 -08003279static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08003280 &raid5_stripecache_size.attr,
3281 &raid5_stripecache_active.attr,
3282 NULL,
3283};
NeilBrown007583c2005-11-08 21:39:30 -08003284static struct attribute_group raid5_attrs_group = {
3285 .name = NULL,
3286 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08003287};
3288
NeilBrown72626682005-09-09 16:23:54 -07003289static int run(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003290{
3291 raid5_conf_t *conf;
3292 int raid_disk, memory;
3293 mdk_rdev_t *rdev;
3294 struct disk_info *disk;
3295 struct list_head *tmp;
NeilBrown02c2de82006-10-03 01:15:47 -07003296 int working_disks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003297
NeilBrown16a53ec2006-06-26 00:27:38 -07003298 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
3299 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
NeilBrown14f8d262006-01-06 00:20:14 -08003300 mdname(mddev), mddev->level);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003301 return -EIO;
3302 }
3303
NeilBrownf6705572006-03-27 01:18:11 -08003304 if (mddev->reshape_position != MaxSector) {
3305 /* Check that we can continue the reshape.
3306 * Currently only disks can change, it must
3307 * increase, and we must be past the point where
3308 * a stripe over-writes itself
3309 */
3310 sector_t here_new, here_old;
3311 int old_disks;
3312
3313 if (mddev->new_level != mddev->level ||
3314 mddev->new_layout != mddev->layout ||
3315 mddev->new_chunk != mddev->chunk_size) {
3316 printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n",
3317 mdname(mddev));
3318 return -EINVAL;
3319 }
3320 if (mddev->delta_disks <= 0) {
3321 printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n",
3322 mdname(mddev));
3323 return -EINVAL;
3324 }
3325 old_disks = mddev->raid_disks - mddev->delta_disks;
3326 /* reshape_position must be on a new-stripe boundary, and one
3327 * further up in new geometry must map after here in old geometry.
3328 */
3329 here_new = mddev->reshape_position;
3330 if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) {
3331 printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n");
3332 return -EINVAL;
3333 }
3334 /* here_new is the stripe we will write to */
3335 here_old = mddev->reshape_position;
3336 sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1));
3337 /* here_old is the first stripe that we might need to read from */
3338 if (here_new >= here_old) {
3339 /* Reading from the same stripe as writing to - bad */
3340 printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n");
3341 return -EINVAL;
3342 }
3343 printk(KERN_INFO "raid5: reshape will continue\n");
3344 /* OK, we should be able to continue; */
3345 }
3346
3347
NeilBrownb55e6bf2006-03-27 01:18:06 -08003348 mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003349 if ((conf = mddev->private) == NULL)
3350 goto abort;
NeilBrownf6705572006-03-27 01:18:11 -08003351 if (mddev->reshape_position == MaxSector) {
3352 conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
3353 } else {
3354 conf->raid_disks = mddev->raid_disks;
3355 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
3356 }
3357
3358 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
NeilBrownb55e6bf2006-03-27 01:18:06 -08003359 GFP_KERNEL);
3360 if (!conf->disks)
3361 goto abort;
NeilBrown9ffae0c2006-01-06 00:20:32 -08003362
Linus Torvalds1da177e2005-04-16 15:20:36 -07003363 conf->mddev = mddev;
3364
NeilBrownfccddba2006-01-06 00:20:33 -08003365 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003366 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003367
NeilBrown16a53ec2006-06-26 00:27:38 -07003368 if (mddev->level == 6) {
3369 conf->spare_page = alloc_page(GFP_KERNEL);
3370 if (!conf->spare_page)
3371 goto abort;
3372 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003373 spin_lock_init(&conf->device_lock);
3374 init_waitqueue_head(&conf->wait_for_stripe);
3375 init_waitqueue_head(&conf->wait_for_overlap);
3376 INIT_LIST_HEAD(&conf->handle_list);
3377 INIT_LIST_HEAD(&conf->delayed_list);
NeilBrown72626682005-09-09 16:23:54 -07003378 INIT_LIST_HEAD(&conf->bitmap_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003379 INIT_LIST_HEAD(&conf->inactive_list);
3380 atomic_set(&conf->active_stripes, 0);
3381 atomic_set(&conf->preread_active_stripes, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003382 atomic_set(&conf->active_aligned_reads, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003383
Linus Torvalds1da177e2005-04-16 15:20:36 -07003384 PRINTK("raid5: run(%s) called.\n", mdname(mddev));
3385
3386 ITERATE_RDEV(mddev,rdev,tmp) {
3387 raid_disk = rdev->raid_disk;
NeilBrownf6705572006-03-27 01:18:11 -08003388 if (raid_disk >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003389 || raid_disk < 0)
3390 continue;
3391 disk = conf->disks + raid_disk;
3392
3393 disk->rdev = rdev;
3394
NeilBrownb2d444d2005-11-08 21:39:31 -08003395 if (test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003396 char b[BDEVNAME_SIZE];
3397 printk(KERN_INFO "raid5: device %s operational as raid"
3398 " disk %d\n", bdevname(rdev->bdev,b),
3399 raid_disk);
NeilBrown02c2de82006-10-03 01:15:47 -07003400 working_disks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003401 }
3402 }
3403
Linus Torvalds1da177e2005-04-16 15:20:36 -07003404 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07003405 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003406 */
NeilBrown02c2de82006-10-03 01:15:47 -07003407 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003408 conf->mddev = mddev;
3409 conf->chunk_size = mddev->chunk_size;
3410 conf->level = mddev->level;
NeilBrown16a53ec2006-06-26 00:27:38 -07003411 if (conf->level == 6)
3412 conf->max_degraded = 2;
3413 else
3414 conf->max_degraded = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003415 conf->algorithm = mddev->layout;
3416 conf->max_nr_stripes = NR_STRIPES;
NeilBrownf6705572006-03-27 01:18:11 -08003417 conf->expand_progress = mddev->reshape_position;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003418
3419 /* device size must be a multiple of chunk size */
3420 mddev->size &= ~(mddev->chunk_size/1024 -1);
NeilBrownb1581562005-07-31 22:34:50 -07003421 mddev->resync_max_sectors = mddev->size << 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003422
NeilBrown16a53ec2006-06-26 00:27:38 -07003423 if (conf->level == 6 && conf->raid_disks < 4) {
3424 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
3425 mdname(mddev), conf->raid_disks);
3426 goto abort;
3427 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003428 if (!conf->chunk_size || conf->chunk_size % 4) {
3429 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
3430 conf->chunk_size, mdname(mddev));
3431 goto abort;
3432 }
3433 if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
3434 printk(KERN_ERR
3435 "raid5: unsupported parity algorithm %d for %s\n",
3436 conf->algorithm, mdname(mddev));
3437 goto abort;
3438 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003439 if (mddev->degraded > conf->max_degraded) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003440 printk(KERN_ERR "raid5: not enough operational devices for %s"
3441 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07003442 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003443 goto abort;
3444 }
3445
NeilBrown16a53ec2006-06-26 00:27:38 -07003446 if (mddev->degraded > 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07003447 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08003448 if (mddev->ok_start_degraded)
3449 printk(KERN_WARNING
3450 "raid5: starting dirty degraded array: %s"
3451 "- data corruption possible.\n",
3452 mdname(mddev));
3453 else {
3454 printk(KERN_ERR
3455 "raid5: cannot start dirty degraded array for %s\n",
3456 mdname(mddev));
3457 goto abort;
3458 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003459 }
3460
3461 {
3462 mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
3463 if (!mddev->thread) {
3464 printk(KERN_ERR
3465 "raid5: couldn't allocate thread for %s\n",
3466 mdname(mddev));
3467 goto abort;
3468 }
3469 }
NeilBrown50368052005-12-12 02:39:17 -08003470 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07003471 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
3472 if (grow_stripes(conf, conf->max_nr_stripes)) {
3473 printk(KERN_ERR
3474 "raid5: couldn't allocate %dkB for buffers\n", memory);
3475 shrink_stripes(conf);
3476 md_unregister_thread(mddev->thread);
3477 goto abort;
3478 } else
3479 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
3480 memory, mdname(mddev));
3481
3482 if (mddev->degraded == 0)
3483 printk("raid5: raid level %d set %s active with %d out of %d"
3484 " devices, algorithm %d\n", conf->level, mdname(mddev),
3485 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
3486 conf->algorithm);
3487 else
3488 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
3489 " out of %d devices, algorithm %d\n", conf->level,
3490 mdname(mddev), mddev->raid_disks - mddev->degraded,
3491 mddev->raid_disks, conf->algorithm);
3492
3493 print_raid5_conf(conf);
3494
NeilBrownf6705572006-03-27 01:18:11 -08003495 if (conf->expand_progress != MaxSector) {
3496 printk("...ok start reshape thread\n");
NeilBrownb578d552006-03-27 01:18:12 -08003497 conf->expand_lo = conf->expand_progress;
NeilBrownf6705572006-03-27 01:18:11 -08003498 atomic_set(&conf->reshape_stripes, 0);
3499 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3500 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3501 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
3502 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3503 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
3504 "%s_reshape");
NeilBrownf6705572006-03-27 01:18:11 -08003505 }
3506
Linus Torvalds1da177e2005-04-16 15:20:36 -07003507 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07003508 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07003509 */
3510 {
NeilBrown16a53ec2006-06-26 00:27:38 -07003511 int data_disks = conf->previous_raid_disks - conf->max_degraded;
3512 int stripe = data_disks *
NeilBrown8932c2e2006-06-26 00:27:36 -07003513 (mddev->chunk_size / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003514 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
3515 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
3516 }
3517
3518 /* Ok, everything is just fine now */
NeilBrown007583c2005-11-08 21:39:30 -08003519 sysfs_create_group(&mddev->kobj, &raid5_attrs_group);
NeilBrown7a5febe2005-05-16 21:53:16 -07003520
3521 mddev->queue->unplug_fn = raid5_unplug_device;
3522 mddev->queue->issue_flush_fn = raid5_issue_flush;
NeilBrownf022b2f2006-10-03 01:15:56 -07003523 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
3524 mddev->queue->backing_dev_info.congested_data = mddev;
3525
NeilBrown16a53ec2006-06-26 00:27:38 -07003526 mddev->array_size = mddev->size * (conf->previous_raid_disks -
3527 conf->max_degraded);
NeilBrown7a5febe2005-05-16 21:53:16 -07003528
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003529 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
3530
Linus Torvalds1da177e2005-04-16 15:20:36 -07003531 return 0;
3532abort:
3533 if (conf) {
3534 print_raid5_conf(conf);
NeilBrown16a53ec2006-06-26 00:27:38 -07003535 safe_put_page(conf->spare_page);
NeilBrownb55e6bf2006-03-27 01:18:06 -08003536 kfree(conf->disks);
NeilBrownfccddba2006-01-06 00:20:33 -08003537 kfree(conf->stripe_hashtbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003538 kfree(conf);
3539 }
3540 mddev->private = NULL;
3541 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
3542 return -EIO;
3543}
3544
3545
3546
NeilBrown3f294f42005-11-08 21:39:25 -08003547static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003548{
3549 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3550
3551 md_unregister_thread(mddev->thread);
3552 mddev->thread = NULL;
3553 shrink_stripes(conf);
NeilBrownfccddba2006-01-06 00:20:33 -08003554 kfree(conf->stripe_hashtbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003555 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
NeilBrown007583c2005-11-08 21:39:30 -08003556 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
NeilBrownb55e6bf2006-03-27 01:18:06 -08003557 kfree(conf->disks);
NeilBrown96de1e62005-11-08 21:39:39 -08003558 kfree(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003559 mddev->private = NULL;
3560 return 0;
3561}
3562
3563#if RAID5_DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07003564static void print_sh (struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003565{
3566 int i;
3567
NeilBrown16a53ec2006-06-26 00:27:38 -07003568 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
3569 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
3570 seq_printf(seq, "sh %llu, count %d.\n",
3571 (unsigned long long)sh->sector, atomic_read(&sh->count));
3572 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003573 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003574 seq_printf(seq, "(cache%d: %p %ld) ",
3575 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003576 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003577 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003578}
3579
NeilBrown16a53ec2006-06-26 00:27:38 -07003580static void printall (struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003581{
3582 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08003583 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003584 int i;
3585
3586 spin_lock_irq(&conf->device_lock);
3587 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08003588 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003589 if (sh->raid_conf != conf)
3590 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07003591 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003592 }
3593 }
3594 spin_unlock_irq(&conf->device_lock);
3595}
3596#endif
3597
3598static void status (struct seq_file *seq, mddev_t *mddev)
3599{
3600 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3601 int i;
3602
3603 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07003604 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003605 for (i = 0; i < conf->raid_disks; i++)
3606 seq_printf (seq, "%s",
3607 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08003608 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003609 seq_printf (seq, "]");
3610#if RAID5_DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07003611 seq_printf (seq, "\n");
3612 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003613#endif
3614}
3615
3616static void print_raid5_conf (raid5_conf_t *conf)
3617{
3618 int i;
3619 struct disk_info *tmp;
3620
3621 printk("RAID5 conf printout:\n");
3622 if (!conf) {
3623 printk("(conf==NULL)\n");
3624 return;
3625 }
NeilBrown02c2de82006-10-03 01:15:47 -07003626 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
3627 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628
3629 for (i = 0; i < conf->raid_disks; i++) {
3630 char b[BDEVNAME_SIZE];
3631 tmp = conf->disks + i;
3632 if (tmp->rdev)
3633 printk(" disk %d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08003634 i, !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07003635 bdevname(tmp->rdev->bdev,b));
3636 }
3637}
3638
3639static int raid5_spare_active(mddev_t *mddev)
3640{
3641 int i;
3642 raid5_conf_t *conf = mddev->private;
3643 struct disk_info *tmp;
3644
3645 for (i = 0; i < conf->raid_disks; i++) {
3646 tmp = conf->disks + i;
3647 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08003648 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07003649 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
3650 unsigned long flags;
3651 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003652 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07003653 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003654 }
3655 }
3656 print_raid5_conf(conf);
3657 return 0;
3658}
3659
3660static int raid5_remove_disk(mddev_t *mddev, int number)
3661{
3662 raid5_conf_t *conf = mddev->private;
3663 int err = 0;
3664 mdk_rdev_t *rdev;
3665 struct disk_info *p = conf->disks + number;
3666
3667 print_raid5_conf(conf);
3668 rdev = p->rdev;
3669 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08003670 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07003671 atomic_read(&rdev->nr_pending)) {
3672 err = -EBUSY;
3673 goto abort;
3674 }
3675 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07003676 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003677 if (atomic_read(&rdev->nr_pending)) {
3678 /* lost the race, try later */
3679 err = -EBUSY;
3680 p->rdev = rdev;
3681 }
3682 }
3683abort:
3684
3685 print_raid5_conf(conf);
3686 return err;
3687}
3688
3689static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
3690{
3691 raid5_conf_t *conf = mddev->private;
3692 int found = 0;
3693 int disk;
3694 struct disk_info *p;
3695
NeilBrown16a53ec2006-06-26 00:27:38 -07003696 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003697 /* no point adding a device */
3698 return 0;
3699
3700 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07003701 * find the disk ... but prefer rdev->saved_raid_disk
3702 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003703 */
NeilBrown16a53ec2006-06-26 00:27:38 -07003704 if (rdev->saved_raid_disk >= 0 &&
3705 conf->disks[rdev->saved_raid_disk].rdev == NULL)
3706 disk = rdev->saved_raid_disk;
3707 else
3708 disk = 0;
3709 for ( ; disk < conf->raid_disks; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003710 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08003711 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003712 rdev->raid_disk = disk;
3713 found = 1;
NeilBrown72626682005-09-09 16:23:54 -07003714 if (rdev->saved_raid_disk != disk)
3715 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08003716 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003717 break;
3718 }
3719 print_raid5_conf(conf);
3720 return found;
3721}
3722
3723static int raid5_resize(mddev_t *mddev, sector_t sectors)
3724{
3725 /* no resync is happening, and there is enough space
3726 * on all devices, so we can resize.
3727 * We need to make sure resync covers any new space.
3728 * If the array is shrinking we should possibly wait until
3729 * any io in the removed space completes, but it hardly seems
3730 * worth it.
3731 */
NeilBrown16a53ec2006-06-26 00:27:38 -07003732 raid5_conf_t *conf = mddev_to_conf(mddev);
3733
Linus Torvalds1da177e2005-04-16 15:20:36 -07003734 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003735 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003736 set_capacity(mddev->gendisk, mddev->array_size << 1);
3737 mddev->changed = 1;
3738 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
3739 mddev->recovery_cp = mddev->size << 1;
3740 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3741 }
3742 mddev->size = sectors /2;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07003743 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003744 return 0;
3745}
3746
NeilBrown29269552006-03-27 01:18:10 -08003747#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08003748static int raid5_check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08003749{
3750 raid5_conf_t *conf = mddev_to_conf(mddev);
3751 int err;
NeilBrown29269552006-03-27 01:18:10 -08003752
NeilBrown63c70c42006-03-27 01:18:13 -08003753 if (mddev->delta_disks < 0 ||
3754 mddev->new_level != mddev->level)
3755 return -EINVAL; /* Cannot shrink array or change level yet */
3756 if (mddev->delta_disks == 0)
NeilBrown29269552006-03-27 01:18:10 -08003757 return 0; /* nothing to do */
3758
3759 /* Can only proceed if there are plenty of stripe_heads.
3760 * We need a minimum of one full stripe,, and for sensible progress
3761 * it is best to have about 4 times that.
3762 * If we require 4 times, then the default 256 4K stripe_heads will
3763 * allow for chunk sizes up to 256K, which is probably OK.
3764 * If the chunk size is greater, user-space should request more
3765 * stripe_heads first.
3766 */
NeilBrown63c70c42006-03-27 01:18:13 -08003767 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
3768 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
NeilBrown29269552006-03-27 01:18:10 -08003769 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
3770 (mddev->chunk_size / STRIPE_SIZE)*4);
3771 return -ENOSPC;
3772 }
3773
NeilBrown63c70c42006-03-27 01:18:13 -08003774 err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
3775 if (err)
3776 return err;
3777
3778 /* looks like we might be able to manage this */
3779 return 0;
3780}
3781
3782static int raid5_start_reshape(mddev_t *mddev)
3783{
3784 raid5_conf_t *conf = mddev_to_conf(mddev);
3785 mdk_rdev_t *rdev;
3786 struct list_head *rtmp;
3787 int spares = 0;
3788 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07003789 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08003790
3791 if (mddev->degraded ||
3792 test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3793 return -EBUSY;
3794
NeilBrown29269552006-03-27 01:18:10 -08003795 ITERATE_RDEV(mddev, rdev, rtmp)
3796 if (rdev->raid_disk < 0 &&
3797 !test_bit(Faulty, &rdev->flags))
3798 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08003799
3800 if (spares < mddev->delta_disks-1)
NeilBrown29269552006-03-27 01:18:10 -08003801 /* Not enough devices even to make a degraded array
3802 * of that size
3803 */
3804 return -EINVAL;
3805
NeilBrownf6705572006-03-27 01:18:11 -08003806 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08003807 spin_lock_irq(&conf->device_lock);
3808 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08003809 conf->raid_disks += mddev->delta_disks;
NeilBrown29269552006-03-27 01:18:10 -08003810 conf->expand_progress = 0;
NeilBrownb578d552006-03-27 01:18:12 -08003811 conf->expand_lo = 0;
NeilBrown29269552006-03-27 01:18:10 -08003812 spin_unlock_irq(&conf->device_lock);
3813
3814 /* Add some new drives, as many as will fit.
3815 * We know there are enough to make the newly sized array work.
3816 */
3817 ITERATE_RDEV(mddev, rdev, rtmp)
3818 if (rdev->raid_disk < 0 &&
3819 !test_bit(Faulty, &rdev->flags)) {
3820 if (raid5_add_disk(mddev, rdev)) {
3821 char nm[20];
3822 set_bit(In_sync, &rdev->flags);
NeilBrown29269552006-03-27 01:18:10 -08003823 added_devices++;
NeilBrown5fd6c1d2006-06-26 00:27:40 -07003824 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08003825 sprintf(nm, "rd%d", rdev->raid_disk);
3826 sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
3827 } else
3828 break;
3829 }
3830
NeilBrownc04be0a2006-10-03 01:15:53 -07003831 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08003832 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
NeilBrownc04be0a2006-10-03 01:15:53 -07003833 spin_unlock_irqrestore(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08003834 mddev->raid_disks = conf->raid_disks;
NeilBrownf6705572006-03-27 01:18:11 -08003835 mddev->reshape_position = 0;
NeilBrown850b2b42006-10-03 01:15:46 -07003836 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08003837
NeilBrown29269552006-03-27 01:18:10 -08003838 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3839 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3840 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
3841 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3842 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
3843 "%s_reshape");
3844 if (!mddev->sync_thread) {
3845 mddev->recovery = 0;
3846 spin_lock_irq(&conf->device_lock);
3847 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
3848 conf->expand_progress = MaxSector;
3849 spin_unlock_irq(&conf->device_lock);
3850 return -EAGAIN;
3851 }
3852 md_wakeup_thread(mddev->sync_thread);
3853 md_new_event(mddev);
3854 return 0;
3855}
3856#endif
3857
3858static void end_reshape(raid5_conf_t *conf)
3859{
3860 struct block_device *bdev;
3861
NeilBrownf6705572006-03-27 01:18:11 -08003862 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
3863 conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1);
3864 set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
3865 conf->mddev->changed = 1;
NeilBrown29269552006-03-27 01:18:10 -08003866
NeilBrownf6705572006-03-27 01:18:11 -08003867 bdev = bdget_disk(conf->mddev->gendisk, 0);
3868 if (bdev) {
3869 mutex_lock(&bdev->bd_inode->i_mutex);
NeilBrown0692c6b2006-11-08 17:44:48 -08003870 i_size_write(bdev->bd_inode, (loff_t)conf->mddev->array_size << 10);
NeilBrownf6705572006-03-27 01:18:11 -08003871 mutex_unlock(&bdev->bd_inode->i_mutex);
3872 bdput(bdev);
3873 }
3874 spin_lock_irq(&conf->device_lock);
3875 conf->expand_progress = MaxSector;
3876 spin_unlock_irq(&conf->device_lock);
3877 conf->mddev->reshape_position = MaxSector;
NeilBrown16a53ec2006-06-26 00:27:38 -07003878
3879 /* read-ahead size must cover two whole stripes, which is
3880 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3881 */
3882 {
3883 int data_disks = conf->previous_raid_disks - conf->max_degraded;
3884 int stripe = data_disks *
3885 (conf->mddev->chunk_size / PAGE_SIZE);
3886 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
3887 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
3888 }
NeilBrown29269552006-03-27 01:18:10 -08003889 }
NeilBrown29269552006-03-27 01:18:10 -08003890}
3891
NeilBrown72626682005-09-09 16:23:54 -07003892static void raid5_quiesce(mddev_t *mddev, int state)
3893{
3894 raid5_conf_t *conf = mddev_to_conf(mddev);
3895
3896 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08003897 case 2: /* resume for a suspend */
3898 wake_up(&conf->wait_for_overlap);
3899 break;
3900
NeilBrown72626682005-09-09 16:23:54 -07003901 case 1: /* stop all writes */
3902 spin_lock_irq(&conf->device_lock);
3903 conf->quiesce = 1;
3904 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003905 atomic_read(&conf->active_stripes) == 0 &&
3906 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07003907 conf->device_lock, /* nothing */);
3908 spin_unlock_irq(&conf->device_lock);
3909 break;
3910
3911 case 0: /* re-enable writes */
3912 spin_lock_irq(&conf->device_lock);
3913 conf->quiesce = 0;
3914 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08003915 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07003916 spin_unlock_irq(&conf->device_lock);
3917 break;
3918 }
NeilBrown72626682005-09-09 16:23:54 -07003919}
NeilBrownb15c2e52006-01-06 00:20:16 -08003920
NeilBrown16a53ec2006-06-26 00:27:38 -07003921static struct mdk_personality raid6_personality =
3922{
3923 .name = "raid6",
3924 .level = 6,
3925 .owner = THIS_MODULE,
3926 .make_request = make_request,
3927 .run = run,
3928 .stop = stop,
3929 .status = status,
3930 .error_handler = error,
3931 .hot_add_disk = raid5_add_disk,
3932 .hot_remove_disk= raid5_remove_disk,
3933 .spare_active = raid5_spare_active,
3934 .sync_request = sync_request,
3935 .resize = raid5_resize,
3936 .quiesce = raid5_quiesce,
3937};
NeilBrown2604b702006-01-06 00:20:36 -08003938static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07003939{
3940 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08003941 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003942 .owner = THIS_MODULE,
3943 .make_request = make_request,
3944 .run = run,
3945 .stop = stop,
3946 .status = status,
3947 .error_handler = error,
3948 .hot_add_disk = raid5_add_disk,
3949 .hot_remove_disk= raid5_remove_disk,
3950 .spare_active = raid5_spare_active,
3951 .sync_request = sync_request,
3952 .resize = raid5_resize,
NeilBrown29269552006-03-27 01:18:10 -08003953#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08003954 .check_reshape = raid5_check_reshape,
3955 .start_reshape = raid5_start_reshape,
NeilBrown29269552006-03-27 01:18:10 -08003956#endif
NeilBrown72626682005-09-09 16:23:54 -07003957 .quiesce = raid5_quiesce,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003958};
3959
NeilBrown2604b702006-01-06 00:20:36 -08003960static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07003961{
NeilBrown2604b702006-01-06 00:20:36 -08003962 .name = "raid4",
3963 .level = 4,
3964 .owner = THIS_MODULE,
3965 .make_request = make_request,
3966 .run = run,
3967 .stop = stop,
3968 .status = status,
3969 .error_handler = error,
3970 .hot_add_disk = raid5_add_disk,
3971 .hot_remove_disk= raid5_remove_disk,
3972 .spare_active = raid5_spare_active,
3973 .sync_request = sync_request,
3974 .resize = raid5_resize,
3975 .quiesce = raid5_quiesce,
3976};
3977
3978static int __init raid5_init(void)
3979{
NeilBrown16a53ec2006-06-26 00:27:38 -07003980 int e;
3981
3982 e = raid6_select_algo();
3983 if ( e )
3984 return e;
3985 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08003986 register_md_personality(&raid5_personality);
3987 register_md_personality(&raid4_personality);
3988 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003989}
3990
NeilBrown2604b702006-01-06 00:20:36 -08003991static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003992{
NeilBrown16a53ec2006-06-26 00:27:38 -07003993 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08003994 unregister_md_personality(&raid5_personality);
3995 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003996}
3997
3998module_init(raid5_init);
3999module_exit(raid5_exit);
4000MODULE_LICENSE("GPL");
4001MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08004002MODULE_ALIAS("md-raid5");
4003MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08004004MODULE_ALIAS("md-level-5");
4005MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07004006MODULE_ALIAS("md-personality-8"); /* RAID6 */
4007MODULE_ALIAS("md-raid6");
4008MODULE_ALIAS("md-level-6");
4009
4010/* This used to be two separate modules, they were: */
4011MODULE_ALIAS("raid5");
4012MODULE_ALIAS("raid6");