blob: 2d6f1a51359cc490dcfd4f9b6bc5b1add12cf9a0 [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>
Dan Williams91c00922007-01-02 13:52:30 -070055#include <linux/async_tx.h>
NeilBrown72626682005-09-09 16:23:54 -070056
Linus Torvalds1da177e2005-04-16 15:20:36 -070057/*
58 * Stripe cache
59 */
60
61#define NR_STRIPES 256
62#define STRIPE_SIZE PAGE_SIZE
63#define STRIPE_SHIFT (PAGE_SHIFT - 9)
64#define STRIPE_SECTORS (STRIPE_SIZE>>9)
65#define IO_THRESHOLD 1
NeilBrownfccddba2006-01-06 00:20:33 -080066#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
Linus Torvalds1da177e2005-04-16 15:20:36 -070067#define HASH_MASK (NR_HASH - 1)
68
NeilBrownfccddba2006-01-06 00:20:33 -080069#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71/* bio's attached to a stripe+device for I/O are linked together in bi_sector
72 * order without overlap. There may be several bio's per stripe+device, and
73 * a bio could span several devices.
74 * When walking this list for a particular stripe+device, we must never proceed
75 * beyond a bio that extends past this device, as the next bio might no longer
76 * be valid.
77 * This macro is used to determine the 'next' bio in the list, given the sector
78 * of the current stripe+device
79 */
80#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
81/*
82 * The following can be used to debug the driver
83 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#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
Dan Williams45b42332007-07-09 11:56:43 -070091#ifdef DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#define inline
93#define __inline__
94#endif
95
NeilBrown16a53ec2006-06-26 00:27:38 -070096#if !RAID6_USE_EMPTY_ZERO_PAGE
97/* In .bss so it's zeroed */
98const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
99#endif
100
101static inline int raid6_next_disk(int disk, int raid_disks)
102{
103 disk++;
104 return (disk < raid_disks) ? disk : 0;
105}
Dan Williamsa4456852007-07-09 11:56:43 -0700106
107static void return_io(struct bio *return_bi)
108{
109 struct bio *bi = return_bi;
110 while (bi) {
Dan Williamsa4456852007-07-09 11:56:43 -0700111
112 return_bi = bi->bi_next;
113 bi->bi_next = NULL;
114 bi->bi_size = 0;
NeilBrown6712ecf2007-09-27 12:47:43 +0200115 bi->bi_end_io(bi,
Dan Williamsa4456852007-07-09 11:56:43 -0700116 test_bit(BIO_UPTODATE, &bi->bi_flags)
117 ? 0 : -EIO);
118 bi = return_bi;
119 }
120}
121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122static void print_raid5_conf (raid5_conf_t *conf);
123
Arjan van de Ven858119e2006-01-14 13:20:43 -0800124static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125{
126 if (atomic_dec_and_test(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200127 BUG_ON(!list_empty(&sh->lru));
128 BUG_ON(atomic_read(&conf->active_stripes)==0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 if (test_bit(STRIPE_HANDLE, &sh->state)) {
NeilBrown7c785b72006-07-10 04:44:16 -0700130 if (test_bit(STRIPE_DELAYED, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 list_add_tail(&sh->lru, &conf->delayed_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700132 blk_plug_device(conf->mddev->queue);
133 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
NeilBrownae3c20c2006-07-10 04:44:17 -0700134 sh->bm_seq - conf->seq_write > 0) {
NeilBrown72626682005-09-09 16:23:54 -0700135 list_add_tail(&sh->lru, &conf->bitmap_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700136 blk_plug_device(conf->mddev->queue);
137 } else {
NeilBrown72626682005-09-09 16:23:54 -0700138 clear_bit(STRIPE_BIT_DELAY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 list_add_tail(&sh->lru, &conf->handle_list);
NeilBrown72626682005-09-09 16:23:54 -0700140 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 md_wakeup_thread(conf->mddev->thread);
142 } else {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700143 BUG_ON(sh->ops.pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
145 atomic_dec(&conf->preread_active_stripes);
146 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
147 md_wakeup_thread(conf->mddev->thread);
148 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 atomic_dec(&conf->active_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800150 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
151 list_add_tail(&sh->lru, &conf->inactive_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 wake_up(&conf->wait_for_stripe);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -0800153 if (conf->retry_read_aligned)
154 md_wakeup_thread(conf->mddev->thread);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800155 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 }
157 }
158}
159static void release_stripe(struct stripe_head *sh)
160{
161 raid5_conf_t *conf = sh->raid_conf;
162 unsigned long flags;
NeilBrown16a53ec2006-06-26 00:27:38 -0700163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 spin_lock_irqsave(&conf->device_lock, flags);
165 __release_stripe(conf, sh);
166 spin_unlock_irqrestore(&conf->device_lock, flags);
167}
168
NeilBrownfccddba2006-01-06 00:20:33 -0800169static inline void remove_hash(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
Dan Williams45b42332007-07-09 11:56:43 -0700171 pr_debug("remove_hash(), stripe %llu\n",
172 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
NeilBrownfccddba2006-01-06 00:20:33 -0800174 hlist_del_init(&sh->hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175}
176
NeilBrown16a53ec2006-06-26 00:27:38 -0700177static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
NeilBrownfccddba2006-01-06 00:20:33 -0800179 struct hlist_head *hp = stripe_hash(conf, sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Dan Williams45b42332007-07-09 11:56:43 -0700181 pr_debug("insert_hash(), stripe %llu\n",
182 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 CHECK_DEVLOCK();
NeilBrownfccddba2006-01-06 00:20:33 -0800185 hlist_add_head(&sh->hash, hp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
188
189/* find an idle stripe, make sure it is unhashed, and return it. */
190static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
191{
192 struct stripe_head *sh = NULL;
193 struct list_head *first;
194
195 CHECK_DEVLOCK();
196 if (list_empty(&conf->inactive_list))
197 goto out;
198 first = conf->inactive_list.next;
199 sh = list_entry(first, struct stripe_head, lru);
200 list_del_init(first);
201 remove_hash(sh);
202 atomic_inc(&conf->active_stripes);
203out:
204 return sh;
205}
206
207static void shrink_buffers(struct stripe_head *sh, int num)
208{
209 struct page *p;
210 int i;
211
212 for (i=0; i<num ; i++) {
213 p = sh->dev[i].page;
214 if (!p)
215 continue;
216 sh->dev[i].page = NULL;
NeilBrown2d1f3b52006-01-06 00:20:31 -0800217 put_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 }
219}
220
221static int grow_buffers(struct stripe_head *sh, int num)
222{
223 int i;
224
225 for (i=0; i<num; i++) {
226 struct page *page;
227
228 if (!(page = alloc_page(GFP_KERNEL))) {
229 return 1;
230 }
231 sh->dev[i].page = page;
232 }
233 return 0;
234}
235
236static void raid5_build_block (struct stripe_head *sh, int i);
237
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800238static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239{
240 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800241 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200243 BUG_ON(atomic_read(&sh->count) != 0);
244 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
Dan Williamsd84e0f12007-01-02 13:52:30 -0700245 BUG_ON(sh->ops.pending || sh->ops.ack || sh->ops.complete);
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700248 pr_debug("init_stripe called, stripe %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 (unsigned long long)sh->sector);
250
251 remove_hash(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -0700252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 sh->sector = sector;
254 sh->pd_idx = pd_idx;
255 sh->state = 0;
256
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800257 sh->disks = disks;
258
259 for (i = sh->disks; i--; ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 struct r5dev *dev = &sh->dev[i];
261
Dan Williamsd84e0f12007-01-02 13:52:30 -0700262 if (dev->toread || dev->read || dev->towrite || dev->written ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 test_bit(R5_LOCKED, &dev->flags)) {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700264 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 (unsigned long long)sh->sector, i, dev->toread,
Dan Williamsd84e0f12007-01-02 13:52:30 -0700266 dev->read, dev->towrite, dev->written,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 test_bit(R5_LOCKED, &dev->flags));
268 BUG();
269 }
270 dev->flags = 0;
271 raid5_build_block(sh, i);
272 }
273 insert_hash(conf, sh);
274}
275
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800276static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277{
278 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -0800279 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
281 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700282 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
NeilBrownfccddba2006-01-06 00:20:33 -0800283 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800284 if (sh->sector == sector && sh->disks == disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return sh;
Dan Williams45b42332007-07-09 11:56:43 -0700286 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 return NULL;
288}
289
290static void unplug_slaves(mddev_t *mddev);
Jens Axboe165125e2007-07-24 09:28:11 +0200291static void raid5_unplug_device(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800293static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
294 int pd_idx, int noblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295{
296 struct stripe_head *sh;
297
Dan Williams45b42332007-07-09 11:56:43 -0700298 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
300 spin_lock_irq(&conf->device_lock);
301
302 do {
NeilBrown72626682005-09-09 16:23:54 -0700303 wait_event_lock_irq(conf->wait_for_stripe,
304 conf->quiesce == 0,
305 conf->device_lock, /* nothing */);
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800306 sh = __find_stripe(conf, sector, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 if (!sh) {
308 if (!conf->inactive_blocked)
309 sh = get_free_stripe(conf);
310 if (noblock && sh == NULL)
311 break;
312 if (!sh) {
313 conf->inactive_blocked = 1;
314 wait_event_lock_irq(conf->wait_for_stripe,
315 !list_empty(&conf->inactive_list) &&
NeilBrown50368052005-12-12 02:39:17 -0800316 (atomic_read(&conf->active_stripes)
317 < (conf->max_nr_stripes *3/4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 || !conf->inactive_blocked),
319 conf->device_lock,
NeilBrownf4370782006-07-10 04:44:14 -0700320 raid5_unplug_device(conf->mddev->queue)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 );
322 conf->inactive_blocked = 0;
323 } else
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800324 init_stripe(sh, sector, pd_idx, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 } else {
326 if (atomic_read(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200327 BUG_ON(!list_empty(&sh->lru));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 } else {
329 if (!test_bit(STRIPE_HANDLE, &sh->state))
330 atomic_inc(&conf->active_stripes);
NeilBrownff4e8d92006-07-10 04:44:16 -0700331 if (list_empty(&sh->lru) &&
332 !test_bit(STRIPE_EXPANDING, &sh->state))
NeilBrown16a53ec2006-06-26 00:27:38 -0700333 BUG();
334 list_del_init(&sh->lru);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 }
336 }
337 } while (sh == NULL);
338
339 if (sh)
340 atomic_inc(&sh->count);
341
342 spin_unlock_irq(&conf->device_lock);
343 return sh;
344}
345
Dan Williamsd84e0f12007-01-02 13:52:30 -0700346/* test_and_ack_op() ensures that we only dequeue an operation once */
347#define test_and_ack_op(op, pend) \
348do { \
349 if (test_bit(op, &sh->ops.pending) && \
350 !test_bit(op, &sh->ops.complete)) { \
351 if (test_and_set_bit(op, &sh->ops.ack)) \
352 clear_bit(op, &pend); \
353 else \
354 ack++; \
355 } else \
356 clear_bit(op, &pend); \
357} while (0)
358
359/* find new work to run, do not resubmit work that is already
360 * in flight
361 */
362static unsigned long get_stripe_work(struct stripe_head *sh)
363{
364 unsigned long pending;
365 int ack = 0;
366
367 pending = sh->ops.pending;
368
369 test_and_ack_op(STRIPE_OP_BIOFILL, pending);
370 test_and_ack_op(STRIPE_OP_COMPUTE_BLK, pending);
371 test_and_ack_op(STRIPE_OP_PREXOR, pending);
372 test_and_ack_op(STRIPE_OP_BIODRAIN, pending);
373 test_and_ack_op(STRIPE_OP_POSTXOR, pending);
374 test_and_ack_op(STRIPE_OP_CHECK, pending);
375 if (test_and_clear_bit(STRIPE_OP_IO, &sh->ops.pending))
376 ack++;
377
378 sh->ops.count -= ack;
Dan Williams4ae3f842007-10-22 20:45:11 -0700379 if (unlikely(sh->ops.count < 0)) {
380 printk(KERN_ERR "pending: %#lx ops.pending: %#lx ops.ack: %#lx "
381 "ops.complete: %#lx\n", pending, sh->ops.pending,
382 sh->ops.ack, sh->ops.complete);
383 BUG();
384 }
Dan Williamsd84e0f12007-01-02 13:52:30 -0700385
386 return pending;
387}
388
NeilBrown6712ecf2007-09-27 12:47:43 +0200389static void
390raid5_end_read_request(struct bio *bi, int error);
391static void
392raid5_end_write_request(struct bio *bi, int error);
Dan Williams91c00922007-01-02 13:52:30 -0700393
394static void ops_run_io(struct stripe_head *sh)
395{
396 raid5_conf_t *conf = sh->raid_conf;
397 int i, disks = sh->disks;
398
399 might_sleep();
400
401 for (i = disks; i--; ) {
402 int rw;
403 struct bio *bi;
404 mdk_rdev_t *rdev;
405 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
406 rw = WRITE;
407 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
408 rw = READ;
409 else
410 continue;
411
412 bi = &sh->dev[i].req;
413
414 bi->bi_rw = rw;
415 if (rw == WRITE)
416 bi->bi_end_io = raid5_end_write_request;
417 else
418 bi->bi_end_io = raid5_end_read_request;
419
420 rcu_read_lock();
421 rdev = rcu_dereference(conf->disks[i].rdev);
422 if (rdev && test_bit(Faulty, &rdev->flags))
423 rdev = NULL;
424 if (rdev)
425 atomic_inc(&rdev->nr_pending);
426 rcu_read_unlock();
427
428 if (rdev) {
429 if (test_bit(STRIPE_SYNCING, &sh->state) ||
430 test_bit(STRIPE_EXPAND_SOURCE, &sh->state) ||
431 test_bit(STRIPE_EXPAND_READY, &sh->state))
432 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
433
434 bi->bi_bdev = rdev->bdev;
435 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
436 __FUNCTION__, (unsigned long long)sh->sector,
437 bi->bi_rw, i);
438 atomic_inc(&sh->count);
439 bi->bi_sector = sh->sector + rdev->data_offset;
440 bi->bi_flags = 1 << BIO_UPTODATE;
441 bi->bi_vcnt = 1;
442 bi->bi_max_vecs = 1;
443 bi->bi_idx = 0;
444 bi->bi_io_vec = &sh->dev[i].vec;
445 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
446 bi->bi_io_vec[0].bv_offset = 0;
447 bi->bi_size = STRIPE_SIZE;
448 bi->bi_next = NULL;
449 if (rw == WRITE &&
450 test_bit(R5_ReWrite, &sh->dev[i].flags))
451 atomic_add(STRIPE_SECTORS,
452 &rdev->corrected_errors);
453 generic_make_request(bi);
454 } else {
455 if (rw == WRITE)
456 set_bit(STRIPE_DEGRADED, &sh->state);
457 pr_debug("skip op %ld on disc %d for sector %llu\n",
458 bi->bi_rw, i, (unsigned long long)sh->sector);
459 clear_bit(R5_LOCKED, &sh->dev[i].flags);
460 set_bit(STRIPE_HANDLE, &sh->state);
461 }
462 }
463}
464
465static struct dma_async_tx_descriptor *
466async_copy_data(int frombio, struct bio *bio, struct page *page,
467 sector_t sector, struct dma_async_tx_descriptor *tx)
468{
469 struct bio_vec *bvl;
470 struct page *bio_page;
471 int i;
472 int page_offset;
473
474 if (bio->bi_sector >= sector)
475 page_offset = (signed)(bio->bi_sector - sector) * 512;
476 else
477 page_offset = (signed)(sector - bio->bi_sector) * -512;
478 bio_for_each_segment(bvl, bio, i) {
479 int len = bio_iovec_idx(bio, i)->bv_len;
480 int clen;
481 int b_offset = 0;
482
483 if (page_offset < 0) {
484 b_offset = -page_offset;
485 page_offset += b_offset;
486 len -= b_offset;
487 }
488
489 if (len > 0 && page_offset + len > STRIPE_SIZE)
490 clen = STRIPE_SIZE - page_offset;
491 else
492 clen = len;
493
494 if (clen > 0) {
495 b_offset += bio_iovec_idx(bio, i)->bv_offset;
496 bio_page = bio_iovec_idx(bio, i)->bv_page;
497 if (frombio)
498 tx = async_memcpy(page, bio_page, page_offset,
499 b_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700500 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700501 tx, NULL, NULL);
502 else
503 tx = async_memcpy(bio_page, page, b_offset,
504 page_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700505 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700506 tx, NULL, NULL);
507 }
508 if (clen < len) /* hit end of page */
509 break;
510 page_offset += len;
511 }
512
513 return tx;
514}
515
516static void ops_complete_biofill(void *stripe_head_ref)
517{
518 struct stripe_head *sh = stripe_head_ref;
519 struct bio *return_bi = NULL;
520 raid5_conf_t *conf = sh->raid_conf;
Dan Williamse4d84902007-09-24 10:06:13 -0700521 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700522
523 pr_debug("%s: stripe %llu\n", __FUNCTION__,
524 (unsigned long long)sh->sector);
525
526 /* clear completed biofills */
527 for (i = sh->disks; i--; ) {
528 struct r5dev *dev = &sh->dev[i];
Dan Williams91c00922007-01-02 13:52:30 -0700529
530 /* acknowledge completion of a biofill operation */
Dan Williamse4d84902007-09-24 10:06:13 -0700531 /* and check if we need to reply to a read request,
532 * new R5_Wantfill requests are held off until
533 * !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)
534 */
535 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700536 struct bio *rbi, *rbi2;
Dan Williams91c00922007-01-02 13:52:30 -0700537
538 /* The access to dev->read is outside of the
539 * spin_lock_irq(&conf->device_lock), but is protected
540 * by the STRIPE_OP_BIOFILL pending bit
541 */
542 BUG_ON(!dev->read);
543 rbi = dev->read;
544 dev->read = NULL;
545 while (rbi && rbi->bi_sector <
546 dev->sector + STRIPE_SECTORS) {
547 rbi2 = r5_next_bio(rbi, dev->sector);
548 spin_lock_irq(&conf->device_lock);
549 if (--rbi->bi_phys_segments == 0) {
550 rbi->bi_next = return_bi;
551 return_bi = rbi;
552 }
553 spin_unlock_irq(&conf->device_lock);
554 rbi = rbi2;
555 }
556 }
557 }
Dan Williams4ae3f842007-10-22 20:45:11 -0700558 set_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
Dan Williams91c00922007-01-02 13:52:30 -0700559
560 return_io(return_bi);
561
Dan Williamse4d84902007-09-24 10:06:13 -0700562 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700563 release_stripe(sh);
564}
565
566static void ops_run_biofill(struct stripe_head *sh)
567{
568 struct dma_async_tx_descriptor *tx = NULL;
569 raid5_conf_t *conf = sh->raid_conf;
570 int i;
571
572 pr_debug("%s: stripe %llu\n", __FUNCTION__,
573 (unsigned long long)sh->sector);
574
575 for (i = sh->disks; i--; ) {
576 struct r5dev *dev = &sh->dev[i];
577 if (test_bit(R5_Wantfill, &dev->flags)) {
578 struct bio *rbi;
579 spin_lock_irq(&conf->device_lock);
580 dev->read = rbi = dev->toread;
581 dev->toread = NULL;
582 spin_unlock_irq(&conf->device_lock);
583 while (rbi && rbi->bi_sector <
584 dev->sector + STRIPE_SECTORS) {
585 tx = async_copy_data(0, rbi, dev->page,
586 dev->sector, tx);
587 rbi = r5_next_bio(rbi, dev->sector);
588 }
589 }
590 }
591
592 atomic_inc(&sh->count);
593 async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
594 ops_complete_biofill, sh);
595}
596
597static void ops_complete_compute5(void *stripe_head_ref)
598{
599 struct stripe_head *sh = stripe_head_ref;
600 int target = sh->ops.target;
601 struct r5dev *tgt = &sh->dev[target];
602
603 pr_debug("%s: stripe %llu\n", __FUNCTION__,
604 (unsigned long long)sh->sector);
605
606 set_bit(R5_UPTODATE, &tgt->flags);
607 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
608 clear_bit(R5_Wantcompute, &tgt->flags);
609 set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
610 set_bit(STRIPE_HANDLE, &sh->state);
611 release_stripe(sh);
612}
613
614static struct dma_async_tx_descriptor *
615ops_run_compute5(struct stripe_head *sh, unsigned long pending)
616{
617 /* kernel stack size limits the total number of disks */
618 int disks = sh->disks;
619 struct page *xor_srcs[disks];
620 int target = sh->ops.target;
621 struct r5dev *tgt = &sh->dev[target];
622 struct page *xor_dest = tgt->page;
623 int count = 0;
624 struct dma_async_tx_descriptor *tx;
625 int i;
626
627 pr_debug("%s: stripe %llu block: %d\n",
628 __FUNCTION__, (unsigned long long)sh->sector, target);
629 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
630
631 for (i = disks; i--; )
632 if (i != target)
633 xor_srcs[count++] = sh->dev[i].page;
634
635 atomic_inc(&sh->count);
636
637 if (unlikely(count == 1))
638 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
639 0, NULL, ops_complete_compute5, sh);
640 else
641 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
642 ASYNC_TX_XOR_ZERO_DST, NULL,
643 ops_complete_compute5, sh);
644
645 /* ack now if postxor is not set to be run */
646 if (tx && !test_bit(STRIPE_OP_POSTXOR, &pending))
647 async_tx_ack(tx);
648
649 return tx;
650}
651
652static void ops_complete_prexor(void *stripe_head_ref)
653{
654 struct stripe_head *sh = stripe_head_ref;
655
656 pr_debug("%s: stripe %llu\n", __FUNCTION__,
657 (unsigned long long)sh->sector);
658
659 set_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
660}
661
662static struct dma_async_tx_descriptor *
663ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
664{
665 /* kernel stack size limits the total number of disks */
666 int disks = sh->disks;
667 struct page *xor_srcs[disks];
668 int count = 0, pd_idx = sh->pd_idx, i;
669
670 /* existing parity data subtracted */
671 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
672
673 pr_debug("%s: stripe %llu\n", __FUNCTION__,
674 (unsigned long long)sh->sector);
675
676 for (i = disks; i--; ) {
677 struct r5dev *dev = &sh->dev[i];
678 /* Only process blocks that are known to be uptodate */
679 if (dev->towrite && test_bit(R5_Wantprexor, &dev->flags))
680 xor_srcs[count++] = dev->page;
681 }
682
683 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
684 ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
685 ops_complete_prexor, sh);
686
687 return tx;
688}
689
690static struct dma_async_tx_descriptor *
Dan Williams6c55be82007-11-14 16:59:35 -0800691ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
692 unsigned long pending)
Dan Williams91c00922007-01-02 13:52:30 -0700693{
694 int disks = sh->disks;
695 int pd_idx = sh->pd_idx, i;
696
697 /* check if prexor is active which means only process blocks
698 * that are part of a read-modify-write (Wantprexor)
699 */
Dan Williams6c55be82007-11-14 16:59:35 -0800700 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
Dan Williams91c00922007-01-02 13:52:30 -0700701
702 pr_debug("%s: stripe %llu\n", __FUNCTION__,
703 (unsigned long long)sh->sector);
704
705 for (i = disks; i--; ) {
706 struct r5dev *dev = &sh->dev[i];
707 struct bio *chosen;
708 int towrite;
709
710 towrite = 0;
711 if (prexor) { /* rmw */
712 if (dev->towrite &&
713 test_bit(R5_Wantprexor, &dev->flags))
714 towrite = 1;
715 } else { /* rcw */
716 if (i != pd_idx && dev->towrite &&
717 test_bit(R5_LOCKED, &dev->flags))
718 towrite = 1;
719 }
720
721 if (towrite) {
722 struct bio *wbi;
723
724 spin_lock(&sh->lock);
725 chosen = dev->towrite;
726 dev->towrite = NULL;
727 BUG_ON(dev->written);
728 wbi = dev->written = chosen;
729 spin_unlock(&sh->lock);
730
731 while (wbi && wbi->bi_sector <
732 dev->sector + STRIPE_SECTORS) {
733 tx = async_copy_data(1, wbi, dev->page,
734 dev->sector, tx);
735 wbi = r5_next_bio(wbi, dev->sector);
736 }
737 }
738 }
739
740 return tx;
741}
742
743static void ops_complete_postxor(void *stripe_head_ref)
744{
745 struct stripe_head *sh = stripe_head_ref;
746
747 pr_debug("%s: stripe %llu\n", __FUNCTION__,
748 (unsigned long long)sh->sector);
749
750 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
751 set_bit(STRIPE_HANDLE, &sh->state);
752 release_stripe(sh);
753}
754
755static void ops_complete_write(void *stripe_head_ref)
756{
757 struct stripe_head *sh = stripe_head_ref;
758 int disks = sh->disks, i, pd_idx = sh->pd_idx;
759
760 pr_debug("%s: stripe %llu\n", __FUNCTION__,
761 (unsigned long long)sh->sector);
762
763 for (i = disks; i--; ) {
764 struct r5dev *dev = &sh->dev[i];
765 if (dev->written || i == pd_idx)
766 set_bit(R5_UPTODATE, &dev->flags);
767 }
768
769 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
770 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
771
772 set_bit(STRIPE_HANDLE, &sh->state);
773 release_stripe(sh);
774}
775
776static void
Dan Williams6c55be82007-11-14 16:59:35 -0800777ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
778 unsigned long pending)
Dan Williams91c00922007-01-02 13:52:30 -0700779{
780 /* kernel stack size limits the total number of disks */
781 int disks = sh->disks;
782 struct page *xor_srcs[disks];
783
784 int count = 0, pd_idx = sh->pd_idx, i;
785 struct page *xor_dest;
Dan Williams6c55be82007-11-14 16:59:35 -0800786 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
Dan Williams91c00922007-01-02 13:52:30 -0700787 unsigned long flags;
788 dma_async_tx_callback callback;
789
790 pr_debug("%s: stripe %llu\n", __FUNCTION__,
791 (unsigned long long)sh->sector);
792
793 /* check if prexor is active which means only process blocks
794 * that are part of a read-modify-write (written)
795 */
796 if (prexor) {
797 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
798 for (i = disks; i--; ) {
799 struct r5dev *dev = &sh->dev[i];
800 if (dev->written)
801 xor_srcs[count++] = dev->page;
802 }
803 } else {
804 xor_dest = sh->dev[pd_idx].page;
805 for (i = disks; i--; ) {
806 struct r5dev *dev = &sh->dev[i];
807 if (i != pd_idx)
808 xor_srcs[count++] = dev->page;
809 }
810 }
811
812 /* check whether this postxor is part of a write */
Dan Williams6c55be82007-11-14 16:59:35 -0800813 callback = test_bit(STRIPE_OP_BIODRAIN, &pending) ?
Dan Williams91c00922007-01-02 13:52:30 -0700814 ops_complete_write : ops_complete_postxor;
815
816 /* 1/ if we prexor'd then the dest is reused as a source
817 * 2/ if we did not prexor then we are redoing the parity
818 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
819 * for the synchronous xor case
820 */
821 flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
822 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
823
824 atomic_inc(&sh->count);
825
826 if (unlikely(count == 1)) {
827 flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
828 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
829 flags, tx, callback, sh);
830 } else
831 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
832 flags, tx, callback, sh);
833}
834
835static void ops_complete_check(void *stripe_head_ref)
836{
837 struct stripe_head *sh = stripe_head_ref;
838 int pd_idx = sh->pd_idx;
839
840 pr_debug("%s: stripe %llu\n", __FUNCTION__,
841 (unsigned long long)sh->sector);
842
843 if (test_and_clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending) &&
844 sh->ops.zero_sum_result == 0)
845 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
846
847 set_bit(STRIPE_OP_CHECK, &sh->ops.complete);
848 set_bit(STRIPE_HANDLE, &sh->state);
849 release_stripe(sh);
850}
851
852static void ops_run_check(struct stripe_head *sh)
853{
854 /* kernel stack size limits the total number of disks */
855 int disks = sh->disks;
856 struct page *xor_srcs[disks];
857 struct dma_async_tx_descriptor *tx;
858
859 int count = 0, pd_idx = sh->pd_idx, i;
860 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
861
862 pr_debug("%s: stripe %llu\n", __FUNCTION__,
863 (unsigned long long)sh->sector);
864
865 for (i = disks; i--; ) {
866 struct r5dev *dev = &sh->dev[i];
867 if (i != pd_idx)
868 xor_srcs[count++] = dev->page;
869 }
870
871 tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
872 &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
873
874 if (tx)
875 set_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
876 else
877 clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
878
879 atomic_inc(&sh->count);
880 tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
881 ops_complete_check, sh);
882}
883
884static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
885{
886 int overlap_clear = 0, i, disks = sh->disks;
887 struct dma_async_tx_descriptor *tx = NULL;
888
889 if (test_bit(STRIPE_OP_BIOFILL, &pending)) {
890 ops_run_biofill(sh);
891 overlap_clear++;
892 }
893
894 if (test_bit(STRIPE_OP_COMPUTE_BLK, &pending))
895 tx = ops_run_compute5(sh, pending);
896
897 if (test_bit(STRIPE_OP_PREXOR, &pending))
898 tx = ops_run_prexor(sh, tx);
899
900 if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
Dan Williams6c55be82007-11-14 16:59:35 -0800901 tx = ops_run_biodrain(sh, tx, pending);
Dan Williams91c00922007-01-02 13:52:30 -0700902 overlap_clear++;
903 }
904
905 if (test_bit(STRIPE_OP_POSTXOR, &pending))
Dan Williams6c55be82007-11-14 16:59:35 -0800906 ops_run_postxor(sh, tx, pending);
Dan Williams91c00922007-01-02 13:52:30 -0700907
908 if (test_bit(STRIPE_OP_CHECK, &pending))
909 ops_run_check(sh);
910
911 if (test_bit(STRIPE_OP_IO, &pending))
912 ops_run_io(sh);
913
914 if (overlap_clear)
915 for (i = disks; i--; ) {
916 struct r5dev *dev = &sh->dev[i];
917 if (test_and_clear_bit(R5_Overlap, &dev->flags))
918 wake_up(&sh->raid_conf->wait_for_overlap);
919 }
920}
921
NeilBrown3f294f42005-11-08 21:39:25 -0800922static int grow_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923{
924 struct stripe_head *sh;
NeilBrown3f294f42005-11-08 21:39:25 -0800925 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
926 if (!sh)
927 return 0;
928 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
929 sh->raid_conf = conf;
930 spin_lock_init(&sh->lock);
931
932 if (grow_buffers(sh, conf->raid_disks)) {
933 shrink_buffers(sh, conf->raid_disks);
934 kmem_cache_free(conf->slab_cache, sh);
935 return 0;
936 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800937 sh->disks = conf->raid_disks;
NeilBrown3f294f42005-11-08 21:39:25 -0800938 /* we just created an active stripe so... */
939 atomic_set(&sh->count, 1);
940 atomic_inc(&conf->active_stripes);
941 INIT_LIST_HEAD(&sh->lru);
942 release_stripe(sh);
943 return 1;
944}
945
946static int grow_stripes(raid5_conf_t *conf, int num)
947{
Christoph Lametere18b8902006-12-06 20:33:20 -0800948 struct kmem_cache *sc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 int devs = conf->raid_disks;
950
NeilBrown42b9beb2007-05-09 02:35:37 -0700951 sprintf(conf->cache_name[0], "raid5-%s", mdname(conf->mddev));
952 sprintf(conf->cache_name[1], "raid5-%s-alt", mdname(conf->mddev));
NeilBrownad01c9e2006-03-27 01:18:07 -0800953 conf->active_name = 0;
954 sc = kmem_cache_create(conf->cache_name[conf->active_name],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +0900956 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 if (!sc)
958 return 1;
959 conf->slab_cache = sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800960 conf->pool_size = devs;
NeilBrown16a53ec2006-06-26 00:27:38 -0700961 while (num--)
NeilBrown3f294f42005-11-08 21:39:25 -0800962 if (!grow_one_stripe(conf))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 return 0;
965}
NeilBrown29269552006-03-27 01:18:10 -0800966
967#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrownad01c9e2006-03-27 01:18:07 -0800968static int resize_stripes(raid5_conf_t *conf, int newsize)
969{
970 /* Make all the stripes able to hold 'newsize' devices.
971 * New slots in each stripe get 'page' set to a new page.
972 *
973 * This happens in stages:
974 * 1/ create a new kmem_cache and allocate the required number of
975 * stripe_heads.
976 * 2/ gather all the old stripe_heads and tranfer the pages across
977 * to the new stripe_heads. This will have the side effect of
978 * freezing the array as once all stripe_heads have been collected,
979 * no IO will be possible. Old stripe heads are freed once their
980 * pages have been transferred over, and the old kmem_cache is
981 * freed when all stripes are done.
982 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
983 * we simple return a failre status - no need to clean anything up.
984 * 4/ allocate new pages for the new slots in the new stripe_heads.
985 * If this fails, we don't bother trying the shrink the
986 * stripe_heads down again, we just leave them as they are.
987 * As each stripe_head is processed the new one is released into
988 * active service.
989 *
990 * Once step2 is started, we cannot afford to wait for a write,
991 * so we use GFP_NOIO allocations.
992 */
993 struct stripe_head *osh, *nsh;
994 LIST_HEAD(newstripes);
995 struct disk_info *ndisks;
996 int err = 0;
Christoph Lametere18b8902006-12-06 20:33:20 -0800997 struct kmem_cache *sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800998 int i;
999
1000 if (newsize <= conf->pool_size)
1001 return 0; /* never bother to shrink */
1002
NeilBrown2a2275d2007-01-26 00:57:11 -08001003 md_allow_write(conf->mddev);
1004
NeilBrownad01c9e2006-03-27 01:18:07 -08001005 /* Step 1 */
1006 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1007 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +09001008 0, 0, NULL);
NeilBrownad01c9e2006-03-27 01:18:07 -08001009 if (!sc)
1010 return -ENOMEM;
1011
1012 for (i = conf->max_nr_stripes; i; i--) {
1013 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1014 if (!nsh)
1015 break;
1016
1017 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1018
1019 nsh->raid_conf = conf;
1020 spin_lock_init(&nsh->lock);
1021
1022 list_add(&nsh->lru, &newstripes);
1023 }
1024 if (i) {
1025 /* didn't get enough, give up */
1026 while (!list_empty(&newstripes)) {
1027 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1028 list_del(&nsh->lru);
1029 kmem_cache_free(sc, nsh);
1030 }
1031 kmem_cache_destroy(sc);
1032 return -ENOMEM;
1033 }
1034 /* Step 2 - Must use GFP_NOIO now.
1035 * OK, we have enough stripes, start collecting inactive
1036 * stripes and copying them over
1037 */
1038 list_for_each_entry(nsh, &newstripes, lru) {
1039 spin_lock_irq(&conf->device_lock);
1040 wait_event_lock_irq(conf->wait_for_stripe,
1041 !list_empty(&conf->inactive_list),
1042 conf->device_lock,
NeilBrownb3b46be2006-03-27 01:18:16 -08001043 unplug_slaves(conf->mddev)
NeilBrownad01c9e2006-03-27 01:18:07 -08001044 );
1045 osh = get_free_stripe(conf);
1046 spin_unlock_irq(&conf->device_lock);
1047 atomic_set(&nsh->count, 1);
1048 for(i=0; i<conf->pool_size; i++)
1049 nsh->dev[i].page = osh->dev[i].page;
1050 for( ; i<newsize; i++)
1051 nsh->dev[i].page = NULL;
1052 kmem_cache_free(conf->slab_cache, osh);
1053 }
1054 kmem_cache_destroy(conf->slab_cache);
1055
1056 /* Step 3.
1057 * At this point, we are holding all the stripes so the array
1058 * is completely stalled, so now is a good time to resize
1059 * conf->disks.
1060 */
1061 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1062 if (ndisks) {
1063 for (i=0; i<conf->raid_disks; i++)
1064 ndisks[i] = conf->disks[i];
1065 kfree(conf->disks);
1066 conf->disks = ndisks;
1067 } else
1068 err = -ENOMEM;
1069
1070 /* Step 4, return new stripes to service */
1071 while(!list_empty(&newstripes)) {
1072 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1073 list_del_init(&nsh->lru);
1074 for (i=conf->raid_disks; i < newsize; i++)
1075 if (nsh->dev[i].page == NULL) {
1076 struct page *p = alloc_page(GFP_NOIO);
1077 nsh->dev[i].page = p;
1078 if (!p)
1079 err = -ENOMEM;
1080 }
1081 release_stripe(nsh);
1082 }
1083 /* critical section pass, GFP_NOIO no longer needed */
1084
1085 conf->slab_cache = sc;
1086 conf->active_name = 1-conf->active_name;
1087 conf->pool_size = newsize;
1088 return err;
1089}
NeilBrown29269552006-03-27 01:18:10 -08001090#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091
NeilBrown3f294f42005-11-08 21:39:25 -08001092static int drop_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093{
1094 struct stripe_head *sh;
1095
NeilBrown3f294f42005-11-08 21:39:25 -08001096 spin_lock_irq(&conf->device_lock);
1097 sh = get_free_stripe(conf);
1098 spin_unlock_irq(&conf->device_lock);
1099 if (!sh)
1100 return 0;
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001101 BUG_ON(atomic_read(&sh->count));
NeilBrownad01c9e2006-03-27 01:18:07 -08001102 shrink_buffers(sh, conf->pool_size);
NeilBrown3f294f42005-11-08 21:39:25 -08001103 kmem_cache_free(conf->slab_cache, sh);
1104 atomic_dec(&conf->active_stripes);
1105 return 1;
1106}
1107
1108static void shrink_stripes(raid5_conf_t *conf)
1109{
1110 while (drop_one_stripe(conf))
1111 ;
1112
NeilBrown29fc7e32006-02-03 03:03:41 -08001113 if (conf->slab_cache)
1114 kmem_cache_destroy(conf->slab_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 conf->slab_cache = NULL;
1116}
1117
NeilBrown6712ecf2007-09-27 12:47:43 +02001118static void raid5_end_read_request(struct bio * bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119{
1120 struct stripe_head *sh = bi->bi_private;
1121 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001122 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
NeilBrownd6950432006-07-10 04:44:20 -07001124 char b[BDEVNAME_SIZE];
1125 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127
1128 for (i=0 ; i<disks; i++)
1129 if (bi == &sh->dev[i].req)
1130 break;
1131
Dan Williams45b42332007-07-09 11:56:43 -07001132 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1133 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 uptodate);
1135 if (i == disks) {
1136 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001137 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 }
1139
1140 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 set_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrown4e5314b2005-11-08 21:39:22 -08001142 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrownd6950432006-07-10 04:44:20 -07001143 rdev = conf->disks[i].rdev;
1144 printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
1145 mdname(conf->mddev), STRIPE_SECTORS,
1146 (unsigned long long)sh->sector + rdev->data_offset,
1147 bdevname(rdev->bdev, b));
NeilBrown4e5314b2005-11-08 21:39:22 -08001148 clear_bit(R5_ReadError, &sh->dev[i].flags);
1149 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1150 }
NeilBrownba22dcb2005-11-08 21:39:31 -08001151 if (atomic_read(&conf->disks[i].rdev->read_errors))
1152 atomic_set(&conf->disks[i].rdev->read_errors, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 } else {
NeilBrownd6950432006-07-10 04:44:20 -07001154 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
NeilBrownba22dcb2005-11-08 21:39:31 -08001155 int retry = 0;
NeilBrownd6950432006-07-10 04:44:20 -07001156 rdev = conf->disks[i].rdev;
1157
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001159 atomic_inc(&rdev->read_errors);
NeilBrownba22dcb2005-11-08 21:39:31 -08001160 if (conf->mddev->degraded)
NeilBrownd6950432006-07-10 04:44:20 -07001161 printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n",
1162 mdname(conf->mddev),
1163 (unsigned long long)sh->sector + rdev->data_offset,
1164 bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001165 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
NeilBrown4e5314b2005-11-08 21:39:22 -08001166 /* Oh, no!!! */
NeilBrownd6950432006-07-10 04:44:20 -07001167 printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
1168 mdname(conf->mddev),
1169 (unsigned long long)sh->sector + rdev->data_offset,
1170 bdn);
1171 else if (atomic_read(&rdev->read_errors)
NeilBrownba22dcb2005-11-08 21:39:31 -08001172 > conf->max_nr_stripes)
NeilBrown14f8d262006-01-06 00:20:14 -08001173 printk(KERN_WARNING
NeilBrownd6950432006-07-10 04:44:20 -07001174 "raid5:%s: Too many read errors, failing device %s.\n",
1175 mdname(conf->mddev), bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001176 else
1177 retry = 1;
1178 if (retry)
1179 set_bit(R5_ReadError, &sh->dev[i].flags);
1180 else {
NeilBrown4e5314b2005-11-08 21:39:22 -08001181 clear_bit(R5_ReadError, &sh->dev[i].flags);
1182 clear_bit(R5_ReWrite, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001183 md_error(conf->mddev, rdev);
NeilBrownba22dcb2005-11-08 21:39:31 -08001184 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 }
1186 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1188 set_bit(STRIPE_HANDLE, &sh->state);
1189 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190}
1191
NeilBrown6712ecf2007-09-27 12:47:43 +02001192static void raid5_end_write_request (struct bio *bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193{
1194 struct stripe_head *sh = bi->bi_private;
1195 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001196 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1198
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 for (i=0 ; i<disks; i++)
1200 if (bi == &sh->dev[i].req)
1201 break;
1202
Dan Williams45b42332007-07-09 11:56:43 -07001203 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1205 uptodate);
1206 if (i == disks) {
1207 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001208 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 }
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 if (!uptodate)
1212 md_error(conf->mddev, conf->disks[i].rdev);
1213
1214 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1215
1216 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1217 set_bit(STRIPE_HANDLE, &sh->state);
NeilBrownc04be0a2006-10-03 01:15:53 -07001218 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219}
1220
1221
1222static sector_t compute_blocknr(struct stripe_head *sh, int i);
1223
1224static void raid5_build_block (struct stripe_head *sh, int i)
1225{
1226 struct r5dev *dev = &sh->dev[i];
1227
1228 bio_init(&dev->req);
1229 dev->req.bi_io_vec = &dev->vec;
1230 dev->req.bi_vcnt++;
1231 dev->req.bi_max_vecs++;
1232 dev->vec.bv_page = dev->page;
1233 dev->vec.bv_len = STRIPE_SIZE;
1234 dev->vec.bv_offset = 0;
1235
1236 dev->req.bi_sector = sh->sector;
1237 dev->req.bi_private = sh;
1238
1239 dev->flags = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001240 dev->sector = compute_blocknr(sh, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241}
1242
1243static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1244{
1245 char b[BDEVNAME_SIZE];
1246 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
Dan Williams45b42332007-07-09 11:56:43 -07001247 pr_debug("raid5: error called\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248
NeilBrownb2d444d2005-11-08 21:39:31 -08001249 if (!test_bit(Faulty, &rdev->flags)) {
NeilBrown850b2b42006-10-03 01:15:46 -07001250 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownc04be0a2006-10-03 01:15:53 -07001251 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1252 unsigned long flags;
1253 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001255 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256 /*
1257 * if recovery was running, make sure it aborts.
1258 */
1259 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
1260 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001261 set_bit(Faulty, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 printk (KERN_ALERT
1263 "raid5: Disk failure on %s, disabling device."
1264 " Operation continuing on %d devices\n",
NeilBrown02c2de82006-10-03 01:15:47 -07001265 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 }
NeilBrown16a53ec2006-06-26 00:27:38 -07001267}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268
1269/*
1270 * Input: a 'big' sector number,
1271 * Output: index of the data and parity disk, and the sector # in them.
1272 */
1273static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
1274 unsigned int data_disks, unsigned int * dd_idx,
1275 unsigned int * pd_idx, raid5_conf_t *conf)
1276{
1277 long stripe;
1278 unsigned long chunk_number;
1279 unsigned int chunk_offset;
1280 sector_t new_sector;
1281 int sectors_per_chunk = conf->chunk_size >> 9;
1282
1283 /* First compute the information on this sector */
1284
1285 /*
1286 * Compute the chunk number and the sector offset inside the chunk
1287 */
1288 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1289 chunk_number = r_sector;
1290 BUG_ON(r_sector != chunk_number);
1291
1292 /*
1293 * Compute the stripe number
1294 */
1295 stripe = chunk_number / data_disks;
1296
1297 /*
1298 * Compute the data disk and parity disk indexes inside the stripe
1299 */
1300 *dd_idx = chunk_number % data_disks;
1301
1302 /*
1303 * Select the parity disk based on the user selected algorithm.
1304 */
NeilBrown16a53ec2006-06-26 00:27:38 -07001305 switch(conf->level) {
1306 case 4:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 *pd_idx = data_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001308 break;
1309 case 5:
1310 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 case ALGORITHM_LEFT_ASYMMETRIC:
1312 *pd_idx = data_disks - stripe % raid_disks;
1313 if (*dd_idx >= *pd_idx)
1314 (*dd_idx)++;
1315 break;
1316 case ALGORITHM_RIGHT_ASYMMETRIC:
1317 *pd_idx = stripe % raid_disks;
1318 if (*dd_idx >= *pd_idx)
1319 (*dd_idx)++;
1320 break;
1321 case ALGORITHM_LEFT_SYMMETRIC:
1322 *pd_idx = data_disks - stripe % raid_disks;
1323 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1324 break;
1325 case ALGORITHM_RIGHT_SYMMETRIC:
1326 *pd_idx = stripe % raid_disks;
1327 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1328 break;
1329 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001330 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -07001332 }
1333 break;
1334 case 6:
1335
1336 /**** FIX THIS ****/
1337 switch (conf->algorithm) {
1338 case ALGORITHM_LEFT_ASYMMETRIC:
1339 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1340 if (*pd_idx == raid_disks-1)
1341 (*dd_idx)++; /* Q D D D P */
1342 else if (*dd_idx >= *pd_idx)
1343 (*dd_idx) += 2; /* D D P Q D */
1344 break;
1345 case ALGORITHM_RIGHT_ASYMMETRIC:
1346 *pd_idx = stripe % raid_disks;
1347 if (*pd_idx == raid_disks-1)
1348 (*dd_idx)++; /* Q D D D P */
1349 else if (*dd_idx >= *pd_idx)
1350 (*dd_idx) += 2; /* D D P Q D */
1351 break;
1352 case ALGORITHM_LEFT_SYMMETRIC:
1353 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1354 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1355 break;
1356 case ALGORITHM_RIGHT_SYMMETRIC:
1357 *pd_idx = stripe % raid_disks;
1358 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1359 break;
1360 default:
1361 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
1362 conf->algorithm);
1363 }
1364 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 }
1366
1367 /*
1368 * Finally, compute the new sector number
1369 */
1370 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1371 return new_sector;
1372}
1373
1374
1375static sector_t compute_blocknr(struct stripe_head *sh, int i)
1376{
1377 raid5_conf_t *conf = sh->raid_conf;
NeilBrownb875e532006-12-10 02:20:49 -08001378 int raid_disks = sh->disks;
1379 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 sector_t new_sector = sh->sector, check;
1381 int sectors_per_chunk = conf->chunk_size >> 9;
1382 sector_t stripe;
1383 int chunk_offset;
1384 int chunk_number, dummy1, dummy2, dd_idx = i;
1385 sector_t r_sector;
1386
NeilBrown16a53ec2006-06-26 00:27:38 -07001387
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1389 stripe = new_sector;
1390 BUG_ON(new_sector != stripe);
1391
NeilBrown16a53ec2006-06-26 00:27:38 -07001392 if (i == sh->pd_idx)
1393 return 0;
1394 switch(conf->level) {
1395 case 4: break;
1396 case 5:
1397 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 case ALGORITHM_LEFT_ASYMMETRIC:
1399 case ALGORITHM_RIGHT_ASYMMETRIC:
1400 if (i > sh->pd_idx)
1401 i--;
1402 break;
1403 case ALGORITHM_LEFT_SYMMETRIC:
1404 case ALGORITHM_RIGHT_SYMMETRIC:
1405 if (i < sh->pd_idx)
1406 i += raid_disks;
1407 i -= (sh->pd_idx + 1);
1408 break;
1409 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001410 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001411 conf->algorithm);
1412 }
1413 break;
1414 case 6:
NeilBrown16a53ec2006-06-26 00:27:38 -07001415 if (i == raid6_next_disk(sh->pd_idx, raid_disks))
1416 return 0; /* It is the Q disk */
1417 switch (conf->algorithm) {
1418 case ALGORITHM_LEFT_ASYMMETRIC:
1419 case ALGORITHM_RIGHT_ASYMMETRIC:
1420 if (sh->pd_idx == raid_disks-1)
1421 i--; /* Q D D D P */
1422 else if (i > sh->pd_idx)
1423 i -= 2; /* D D P Q D */
1424 break;
1425 case ALGORITHM_LEFT_SYMMETRIC:
1426 case ALGORITHM_RIGHT_SYMMETRIC:
1427 if (sh->pd_idx == raid_disks-1)
1428 i--; /* Q D D D P */
1429 else {
1430 /* D D P Q D */
1431 if (i < sh->pd_idx)
1432 i += raid_disks;
1433 i -= (sh->pd_idx + 2);
1434 }
1435 break;
1436 default:
1437 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -07001439 }
1440 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 }
1442
1443 chunk_number = stripe * data_disks + i;
1444 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
1445
1446 check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
1447 if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
NeilBrown14f8d262006-01-06 00:20:14 -08001448 printk(KERN_ERR "compute_blocknr: map not correct\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 return 0;
1450 }
1451 return r_sector;
1452}
1453
1454
1455
1456/*
NeilBrown16a53ec2006-06-26 00:27:38 -07001457 * Copy data between a page in the stripe cache, and one or more bion
1458 * The page could align with the middle of the bio, or there could be
1459 * several bion, each with several bio_vecs, which cover part of the page
1460 * Multiple bion are linked together on bi_next. There may be extras
1461 * at the end of this list. We ignore them.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 */
1463static void copy_data(int frombio, struct bio *bio,
1464 struct page *page,
1465 sector_t sector)
1466{
1467 char *pa = page_address(page);
1468 struct bio_vec *bvl;
1469 int i;
1470 int page_offset;
1471
1472 if (bio->bi_sector >= sector)
1473 page_offset = (signed)(bio->bi_sector - sector) * 512;
1474 else
1475 page_offset = (signed)(sector - bio->bi_sector) * -512;
1476 bio_for_each_segment(bvl, bio, i) {
1477 int len = bio_iovec_idx(bio,i)->bv_len;
1478 int clen;
1479 int b_offset = 0;
1480
1481 if (page_offset < 0) {
1482 b_offset = -page_offset;
1483 page_offset += b_offset;
1484 len -= b_offset;
1485 }
1486
1487 if (len > 0 && page_offset + len > STRIPE_SIZE)
1488 clen = STRIPE_SIZE - page_offset;
1489 else clen = len;
NeilBrown16a53ec2006-06-26 00:27:38 -07001490
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491 if (clen > 0) {
1492 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
1493 if (frombio)
1494 memcpy(pa+page_offset, ba+b_offset, clen);
1495 else
1496 memcpy(ba+b_offset, pa+page_offset, clen);
1497 __bio_kunmap_atomic(ba, KM_USER0);
1498 }
1499 if (clen < len) /* hit end of page */
1500 break;
1501 page_offset += len;
1502 }
1503}
1504
Dan Williams9bc89cd2007-01-02 11:10:44 -07001505#define check_xor() do { \
1506 if (count == MAX_XOR_BLOCKS) { \
1507 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1508 count = 0; \
1509 } \
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 } while(0)
1511
NeilBrown16a53ec2006-06-26 00:27:38 -07001512static void compute_parity6(struct stripe_head *sh, int method)
1513{
1514 raid6_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08001515 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
NeilBrown16a53ec2006-06-26 00:27:38 -07001516 struct bio *chosen;
1517 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1518 void *ptrs[disks];
1519
1520 qd_idx = raid6_next_disk(pd_idx, disks);
1521 d0_idx = raid6_next_disk(qd_idx, disks);
1522
Dan Williams45b42332007-07-09 11:56:43 -07001523 pr_debug("compute_parity, stripe %llu, method %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001524 (unsigned long long)sh->sector, method);
1525
1526 switch(method) {
1527 case READ_MODIFY_WRITE:
1528 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1529 case RECONSTRUCT_WRITE:
1530 for (i= disks; i-- ;)
1531 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1532 chosen = sh->dev[i].towrite;
1533 sh->dev[i].towrite = NULL;
1534
1535 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1536 wake_up(&conf->wait_for_overlap);
1537
Eric Sesterhenn52e5f9d2006-10-03 23:33:23 +02001538 BUG_ON(sh->dev[i].written);
NeilBrown16a53ec2006-06-26 00:27:38 -07001539 sh->dev[i].written = chosen;
1540 }
1541 break;
1542 case CHECK_PARITY:
1543 BUG(); /* Not implemented yet */
1544 }
1545
1546 for (i = disks; i--;)
1547 if (sh->dev[i].written) {
1548 sector_t sector = sh->dev[i].sector;
1549 struct bio *wbi = sh->dev[i].written;
1550 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1551 copy_data(1, wbi, sh->dev[i].page, sector);
1552 wbi = r5_next_bio(wbi, sector);
1553 }
1554
1555 set_bit(R5_LOCKED, &sh->dev[i].flags);
1556 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1557 }
1558
1559// switch(method) {
1560// case RECONSTRUCT_WRITE:
1561// case CHECK_PARITY:
1562// case UPDATE_PARITY:
1563 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1564 /* FIX: Is this ordering of drives even remotely optimal? */
1565 count = 0;
1566 i = d0_idx;
1567 do {
1568 ptrs[count++] = page_address(sh->dev[i].page);
1569 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1570 printk("block %d/%d not uptodate on parity calc\n", i,count);
1571 i = raid6_next_disk(i, disks);
1572 } while ( i != d0_idx );
1573// break;
1574// }
1575
1576 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
1577
1578 switch(method) {
1579 case RECONSTRUCT_WRITE:
1580 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1581 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1582 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1583 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1584 break;
1585 case UPDATE_PARITY:
1586 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1587 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1588 break;
1589 }
1590}
1591
1592
1593/* Compute one missing block */
1594static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1595{
NeilBrownf4168852007-02-28 20:11:53 -08001596 int i, count, disks = sh->disks;
Dan Williams9bc89cd2007-01-02 11:10:44 -07001597 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
NeilBrown16a53ec2006-06-26 00:27:38 -07001598 int pd_idx = sh->pd_idx;
1599 int qd_idx = raid6_next_disk(pd_idx, disks);
1600
Dan Williams45b42332007-07-09 11:56:43 -07001601 pr_debug("compute_block_1, stripe %llu, idx %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001602 (unsigned long long)sh->sector, dd_idx);
1603
1604 if ( dd_idx == qd_idx ) {
1605 /* We're actually computing the Q drive */
1606 compute_parity6(sh, UPDATE_PARITY);
1607 } else {
Dan Williams9bc89cd2007-01-02 11:10:44 -07001608 dest = page_address(sh->dev[dd_idx].page);
1609 if (!nozero) memset(dest, 0, STRIPE_SIZE);
1610 count = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001611 for (i = disks ; i--; ) {
1612 if (i == dd_idx || i == qd_idx)
1613 continue;
1614 p = page_address(sh->dev[i].page);
1615 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1616 ptr[count++] = p;
1617 else
1618 printk("compute_block() %d, stripe %llu, %d"
1619 " not present\n", dd_idx,
1620 (unsigned long long)sh->sector, i);
1621
1622 check_xor();
1623 }
Dan Williams9bc89cd2007-01-02 11:10:44 -07001624 if (count)
1625 xor_blocks(count, STRIPE_SIZE, dest, ptr);
NeilBrown16a53ec2006-06-26 00:27:38 -07001626 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1627 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1628 }
1629}
1630
1631/* Compute two missing blocks */
1632static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1633{
NeilBrownf4168852007-02-28 20:11:53 -08001634 int i, count, disks = sh->disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001635 int pd_idx = sh->pd_idx;
1636 int qd_idx = raid6_next_disk(pd_idx, disks);
1637 int d0_idx = raid6_next_disk(qd_idx, disks);
1638 int faila, failb;
1639
1640 /* faila and failb are disk numbers relative to d0_idx */
1641 /* pd_idx become disks-2 and qd_idx become disks-1 */
1642 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
1643 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
1644
1645 BUG_ON(faila == failb);
1646 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1647
Dan Williams45b42332007-07-09 11:56:43 -07001648 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001649 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
1650
1651 if ( failb == disks-1 ) {
1652 /* Q disk is one of the missing disks */
1653 if ( faila == disks-2 ) {
1654 /* Missing P+Q, just recompute */
1655 compute_parity6(sh, UPDATE_PARITY);
1656 return;
1657 } else {
1658 /* We're missing D+Q; recompute D from P */
1659 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0);
1660 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1661 return;
1662 }
1663 }
1664
1665 /* We're missing D+P or D+D; build pointer table */
1666 {
1667 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1668 void *ptrs[disks];
1669
1670 count = 0;
1671 i = d0_idx;
1672 do {
1673 ptrs[count++] = page_address(sh->dev[i].page);
1674 i = raid6_next_disk(i, disks);
1675 if (i != dd_idx1 && i != dd_idx2 &&
1676 !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1677 printk("compute_2 with missing block %d/%d\n", count, i);
1678 } while ( i != d0_idx );
1679
1680 if ( failb == disks-2 ) {
1681 /* We're missing D+P. */
1682 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
1683 } else {
1684 /* We're missing D+D. */
1685 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
1686 }
1687
1688 /* Both the above update both missing blocks */
1689 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1690 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1691 }
1692}
1693
Dan Williamse33129d2007-01-02 13:52:30 -07001694static int
1695handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
1696{
1697 int i, pd_idx = sh->pd_idx, disks = sh->disks;
1698 int locked = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001699
Dan Williamse33129d2007-01-02 13:52:30 -07001700 if (rcw) {
1701 /* if we are not expanding this is a proper write request, and
1702 * there will be bios with new data to be drained into the
1703 * stripe cache
1704 */
1705 if (!expand) {
1706 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
1707 sh->ops.count++;
1708 }
1709
1710 set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
1711 sh->ops.count++;
1712
1713 for (i = disks; i--; ) {
1714 struct r5dev *dev = &sh->dev[i];
1715
1716 if (dev->towrite) {
1717 set_bit(R5_LOCKED, &dev->flags);
1718 if (!expand)
1719 clear_bit(R5_UPTODATE, &dev->flags);
1720 locked++;
1721 }
1722 }
1723 } else {
1724 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
1725 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
1726
1727 set_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
1728 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
1729 set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
1730
1731 sh->ops.count += 3;
1732
1733 for (i = disks; i--; ) {
1734 struct r5dev *dev = &sh->dev[i];
1735 if (i == pd_idx)
1736 continue;
1737
1738 /* For a read-modify write there may be blocks that are
1739 * locked for reading while others are ready to be
1740 * written so we distinguish these blocks by the
1741 * R5_Wantprexor bit
1742 */
1743 if (dev->towrite &&
1744 (test_bit(R5_UPTODATE, &dev->flags) ||
1745 test_bit(R5_Wantcompute, &dev->flags))) {
1746 set_bit(R5_Wantprexor, &dev->flags);
1747 set_bit(R5_LOCKED, &dev->flags);
1748 clear_bit(R5_UPTODATE, &dev->flags);
1749 locked++;
1750 }
1751 }
1752 }
1753
1754 /* keep the parity disk locked while asynchronous operations
1755 * are in flight
1756 */
1757 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1758 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1759 locked++;
1760
1761 pr_debug("%s: stripe %llu locked: %d pending: %lx\n",
1762 __FUNCTION__, (unsigned long long)sh->sector,
1763 locked, sh->ops.pending);
1764
1765 return locked;
1766}
NeilBrown16a53ec2006-06-26 00:27:38 -07001767
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768/*
1769 * Each stripe/dev can have one or more bion attached.
NeilBrown16a53ec2006-06-26 00:27:38 -07001770 * toread/towrite point to the first in a chain.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771 * The bi_next chain must be in order.
1772 */
1773static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1774{
1775 struct bio **bip;
1776 raid5_conf_t *conf = sh->raid_conf;
NeilBrown72626682005-09-09 16:23:54 -07001777 int firstwrite=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778
Dan Williams45b42332007-07-09 11:56:43 -07001779 pr_debug("adding bh b#%llu to stripe s#%llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780 (unsigned long long)bi->bi_sector,
1781 (unsigned long long)sh->sector);
1782
1783
1784 spin_lock(&sh->lock);
1785 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07001786 if (forwrite) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 bip = &sh->dev[dd_idx].towrite;
NeilBrown72626682005-09-09 16:23:54 -07001788 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1789 firstwrite = 1;
1790 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001791 bip = &sh->dev[dd_idx].toread;
1792 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1793 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1794 goto overlap;
1795 bip = & (*bip)->bi_next;
1796 }
1797 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1798 goto overlap;
1799
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001800 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 if (*bip)
1802 bi->bi_next = *bip;
1803 *bip = bi;
1804 bi->bi_phys_segments ++;
1805 spin_unlock_irq(&conf->device_lock);
1806 spin_unlock(&sh->lock);
1807
Dan Williams45b42332007-07-09 11:56:43 -07001808 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001809 (unsigned long long)bi->bi_sector,
1810 (unsigned long long)sh->sector, dd_idx);
1811
NeilBrown72626682005-09-09 16:23:54 -07001812 if (conf->mddev->bitmap && firstwrite) {
NeilBrown72626682005-09-09 16:23:54 -07001813 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1814 STRIPE_SECTORS, 0);
NeilBrownae3c20c2006-07-10 04:44:17 -07001815 sh->bm_seq = conf->seq_flush+1;
NeilBrown72626682005-09-09 16:23:54 -07001816 set_bit(STRIPE_BIT_DELAY, &sh->state);
1817 }
1818
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 if (forwrite) {
1820 /* check if page is covered */
1821 sector_t sector = sh->dev[dd_idx].sector;
1822 for (bi=sh->dev[dd_idx].towrite;
1823 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1824 bi && bi->bi_sector <= sector;
1825 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1826 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1827 sector = bi->bi_sector + (bi->bi_size>>9);
1828 }
1829 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1830 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1831 }
1832 return 1;
1833
1834 overlap:
1835 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1836 spin_unlock_irq(&conf->device_lock);
1837 spin_unlock(&sh->lock);
1838 return 0;
1839}
1840
NeilBrown29269552006-03-27 01:18:10 -08001841static void end_reshape(raid5_conf_t *conf);
1842
NeilBrown16a53ec2006-06-26 00:27:38 -07001843static int page_is_zero(struct page *p)
1844{
1845 char *a = page_address(p);
1846 return ((*(u32*)a) == 0 &&
1847 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1848}
1849
NeilBrownccfcc3c2006-03-27 01:18:09 -08001850static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1851{
1852 int sectors_per_chunk = conf->chunk_size >> 9;
NeilBrownccfcc3c2006-03-27 01:18:09 -08001853 int pd_idx, dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07001854 int chunk_offset = sector_div(stripe, sectors_per_chunk);
1855
NeilBrownb875e532006-12-10 02:20:49 -08001856 raid5_compute_sector(stripe * (disks - conf->max_degraded)
1857 *sectors_per_chunk + chunk_offset,
1858 disks, disks - conf->max_degraded,
1859 &dd_idx, &pd_idx, conf);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001860 return pd_idx;
1861}
1862
Dan Williamsa4456852007-07-09 11:56:43 -07001863static void
1864handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
1865 struct stripe_head_state *s, int disks,
1866 struct bio **return_bi)
1867{
1868 int i;
1869 for (i = disks; i--; ) {
1870 struct bio *bi;
1871 int bitmap_end = 0;
1872
1873 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1874 mdk_rdev_t *rdev;
1875 rcu_read_lock();
1876 rdev = rcu_dereference(conf->disks[i].rdev);
1877 if (rdev && test_bit(In_sync, &rdev->flags))
1878 /* multiple read failures in one stripe */
1879 md_error(conf->mddev, rdev);
1880 rcu_read_unlock();
1881 }
1882 spin_lock_irq(&conf->device_lock);
1883 /* fail all writes first */
1884 bi = sh->dev[i].towrite;
1885 sh->dev[i].towrite = NULL;
1886 if (bi) {
1887 s->to_write--;
1888 bitmap_end = 1;
1889 }
1890
1891 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1892 wake_up(&conf->wait_for_overlap);
1893
1894 while (bi && bi->bi_sector <
1895 sh->dev[i].sector + STRIPE_SECTORS) {
1896 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
1897 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1898 if (--bi->bi_phys_segments == 0) {
1899 md_write_end(conf->mddev);
1900 bi->bi_next = *return_bi;
1901 *return_bi = bi;
1902 }
1903 bi = nextbi;
1904 }
1905 /* and fail all 'written' */
1906 bi = sh->dev[i].written;
1907 sh->dev[i].written = NULL;
1908 if (bi) bitmap_end = 1;
1909 while (bi && bi->bi_sector <
1910 sh->dev[i].sector + STRIPE_SECTORS) {
1911 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
1912 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1913 if (--bi->bi_phys_segments == 0) {
1914 md_write_end(conf->mddev);
1915 bi->bi_next = *return_bi;
1916 *return_bi = bi;
1917 }
1918 bi = bi2;
1919 }
1920
Dan Williamsb5e98d62007-01-02 13:52:31 -07001921 /* fail any reads if this device is non-operational and
1922 * the data has not reached the cache yet.
1923 */
1924 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
1925 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
1926 test_bit(R5_ReadError, &sh->dev[i].flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07001927 bi = sh->dev[i].toread;
1928 sh->dev[i].toread = NULL;
1929 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1930 wake_up(&conf->wait_for_overlap);
1931 if (bi) s->to_read--;
1932 while (bi && bi->bi_sector <
1933 sh->dev[i].sector + STRIPE_SECTORS) {
1934 struct bio *nextbi =
1935 r5_next_bio(bi, sh->dev[i].sector);
1936 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1937 if (--bi->bi_phys_segments == 0) {
1938 bi->bi_next = *return_bi;
1939 *return_bi = bi;
1940 }
1941 bi = nextbi;
1942 }
1943 }
1944 spin_unlock_irq(&conf->device_lock);
1945 if (bitmap_end)
1946 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
1947 STRIPE_SECTORS, 0, 0);
1948 }
1949
1950}
1951
Dan Williamsf38e1212007-01-02 13:52:30 -07001952/* __handle_issuing_new_read_requests5 - returns 0 if there are no more disks
1953 * to process
1954 */
1955static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
1956 struct stripe_head_state *s, int disk_idx, int disks)
1957{
1958 struct r5dev *dev = &sh->dev[disk_idx];
1959 struct r5dev *failed_dev = &sh->dev[s->failed_num];
1960
1961 /* don't schedule compute operations or reads on the parity block while
1962 * a check is in flight
1963 */
1964 if ((disk_idx == sh->pd_idx) &&
1965 test_bit(STRIPE_OP_CHECK, &sh->ops.pending))
1966 return ~0;
1967
1968 /* is the data in this block needed, and can we get it? */
1969 if (!test_bit(R5_LOCKED, &dev->flags) &&
1970 !test_bit(R5_UPTODATE, &dev->flags) && (dev->toread ||
1971 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
1972 s->syncing || s->expanding || (s->failed &&
1973 (failed_dev->toread || (failed_dev->towrite &&
1974 !test_bit(R5_OVERWRITE, &failed_dev->flags)
1975 ))))) {
1976 /* 1/ We would like to get this block, possibly by computing it,
1977 * but we might not be able to.
1978 *
1979 * 2/ Since parity check operations potentially make the parity
1980 * block !uptodate it will need to be refreshed before any
1981 * compute operations on data disks are scheduled.
1982 *
1983 * 3/ We hold off parity block re-reads until check operations
1984 * have quiesced.
1985 */
1986 if ((s->uptodate == disks - 1) &&
1987 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
1988 set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
1989 set_bit(R5_Wantcompute, &dev->flags);
1990 sh->ops.target = disk_idx;
1991 s->req_compute = 1;
1992 sh->ops.count++;
1993 /* Careful: from this point on 'uptodate' is in the eye
1994 * of raid5_run_ops which services 'compute' operations
1995 * before writes. R5_Wantcompute flags a block that will
1996 * be R5_UPTODATE by the time it is needed for a
1997 * subsequent operation.
1998 */
1999 s->uptodate++;
2000 return 0; /* uptodate + compute == disks */
2001 } else if ((s->uptodate < disks - 1) &&
2002 test_bit(R5_Insync, &dev->flags)) {
2003 /* Note: we hold off compute operations while checks are
2004 * in flight, but we still prefer 'compute' over 'read'
2005 * hence we only read if (uptodate < * disks-1)
2006 */
2007 set_bit(R5_LOCKED, &dev->flags);
2008 set_bit(R5_Wantread, &dev->flags);
2009 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2010 sh->ops.count++;
2011 s->locked++;
2012 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2013 s->syncing);
2014 }
2015 }
2016
2017 return ~0;
2018}
2019
Dan Williamsa4456852007-07-09 11:56:43 -07002020static void handle_issuing_new_read_requests5(struct stripe_head *sh,
2021 struct stripe_head_state *s, int disks)
2022{
2023 int i;
Dan Williamsf38e1212007-01-02 13:52:30 -07002024
2025 /* Clear completed compute operations. Parity recovery
2026 * (STRIPE_OP_MOD_REPAIR_PD) implies a write-back which is handled
2027 * later on in this routine
2028 */
2029 if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
2030 !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2031 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
2032 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
2033 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
2034 }
2035
2036 /* look for blocks to read/compute, skip this if a compute
2037 * is already in flight, or if the stripe contents are in the
2038 * midst of changing due to a write
2039 */
2040 if (!test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending) &&
2041 !test_bit(STRIPE_OP_PREXOR, &sh->ops.pending) &&
2042 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
2043 for (i = disks; i--; )
2044 if (__handle_issuing_new_read_requests5(
2045 sh, s, i, disks) == 0)
2046 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002047 }
2048 set_bit(STRIPE_HANDLE, &sh->state);
2049}
2050
2051static void handle_issuing_new_read_requests6(struct stripe_head *sh,
2052 struct stripe_head_state *s, struct r6_state *r6s,
2053 int disks)
2054{
2055 int i;
2056 for (i = disks; i--; ) {
2057 struct r5dev *dev = &sh->dev[i];
2058 if (!test_bit(R5_LOCKED, &dev->flags) &&
2059 !test_bit(R5_UPTODATE, &dev->flags) &&
2060 (dev->toread || (dev->towrite &&
2061 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2062 s->syncing || s->expanding ||
2063 (s->failed >= 1 &&
2064 (sh->dev[r6s->failed_num[0]].toread ||
2065 s->to_write)) ||
2066 (s->failed >= 2 &&
2067 (sh->dev[r6s->failed_num[1]].toread ||
2068 s->to_write)))) {
2069 /* we would like to get this block, possibly
2070 * by computing it, but we might not be able to
2071 */
2072 if (s->uptodate == disks-1) {
Dan Williams45b42332007-07-09 11:56:43 -07002073 pr_debug("Computing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002074 (unsigned long long)sh->sector, i);
2075 compute_block_1(sh, i, 0);
2076 s->uptodate++;
2077 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2078 /* Computing 2-failure is *very* expensive; only
2079 * do it if failed >= 2
2080 */
2081 int other;
2082 for (other = disks; other--; ) {
2083 if (other == i)
2084 continue;
2085 if (!test_bit(R5_UPTODATE,
2086 &sh->dev[other].flags))
2087 break;
2088 }
2089 BUG_ON(other < 0);
Dan Williams45b42332007-07-09 11:56:43 -07002090 pr_debug("Computing stripe %llu blocks %d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002091 (unsigned long long)sh->sector,
2092 i, other);
2093 compute_block_2(sh, i, other);
2094 s->uptodate += 2;
2095 } else if (test_bit(R5_Insync, &dev->flags)) {
2096 set_bit(R5_LOCKED, &dev->flags);
2097 set_bit(R5_Wantread, &dev->flags);
2098 s->locked++;
Dan Williams45b42332007-07-09 11:56:43 -07002099 pr_debug("Reading block %d (sync=%d)\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002100 i, s->syncing);
2101 }
2102 }
2103 }
2104 set_bit(STRIPE_HANDLE, &sh->state);
2105}
2106
2107
2108/* handle_completed_write_requests
2109 * any written block on an uptodate or failed drive can be returned.
2110 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2111 * never LOCKED, so we don't need to test 'failed' directly.
2112 */
2113static void handle_completed_write_requests(raid5_conf_t *conf,
2114 struct stripe_head *sh, int disks, struct bio **return_bi)
2115{
2116 int i;
2117 struct r5dev *dev;
2118
2119 for (i = disks; i--; )
2120 if (sh->dev[i].written) {
2121 dev = &sh->dev[i];
2122 if (!test_bit(R5_LOCKED, &dev->flags) &&
2123 test_bit(R5_UPTODATE, &dev->flags)) {
2124 /* We can return any write requests */
2125 struct bio *wbi, *wbi2;
2126 int bitmap_end = 0;
Dan Williams45b42332007-07-09 11:56:43 -07002127 pr_debug("Return write for disc %d\n", i);
Dan Williamsa4456852007-07-09 11:56:43 -07002128 spin_lock_irq(&conf->device_lock);
2129 wbi = dev->written;
2130 dev->written = NULL;
2131 while (wbi && wbi->bi_sector <
2132 dev->sector + STRIPE_SECTORS) {
2133 wbi2 = r5_next_bio(wbi, dev->sector);
2134 if (--wbi->bi_phys_segments == 0) {
2135 md_write_end(conf->mddev);
2136 wbi->bi_next = *return_bi;
2137 *return_bi = wbi;
2138 }
2139 wbi = wbi2;
2140 }
2141 if (dev->towrite == NULL)
2142 bitmap_end = 1;
2143 spin_unlock_irq(&conf->device_lock);
2144 if (bitmap_end)
2145 bitmap_endwrite(conf->mddev->bitmap,
2146 sh->sector,
2147 STRIPE_SECTORS,
2148 !test_bit(STRIPE_DEGRADED, &sh->state),
2149 0);
2150 }
2151 }
2152}
2153
2154static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
2155 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2156{
2157 int rmw = 0, rcw = 0, i;
2158 for (i = disks; i--; ) {
2159 /* would I have to read this buffer for read_modify_write */
2160 struct r5dev *dev = &sh->dev[i];
2161 if ((dev->towrite || i == sh->pd_idx) &&
2162 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002163 !(test_bit(R5_UPTODATE, &dev->flags) ||
2164 test_bit(R5_Wantcompute, &dev->flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002165 if (test_bit(R5_Insync, &dev->flags))
2166 rmw++;
2167 else
2168 rmw += 2*disks; /* cannot read it */
2169 }
2170 /* Would I have to read this buffer for reconstruct_write */
2171 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2172 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002173 !(test_bit(R5_UPTODATE, &dev->flags) ||
2174 test_bit(R5_Wantcompute, &dev->flags))) {
2175 if (test_bit(R5_Insync, &dev->flags)) rcw++;
Dan Williamsa4456852007-07-09 11:56:43 -07002176 else
2177 rcw += 2*disks;
2178 }
2179 }
Dan Williams45b42332007-07-09 11:56:43 -07002180 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002181 (unsigned long long)sh->sector, rmw, rcw);
2182 set_bit(STRIPE_HANDLE, &sh->state);
2183 if (rmw < rcw && rmw > 0)
2184 /* prefer read-modify-write, but need to get some data */
2185 for (i = disks; i--; ) {
2186 struct r5dev *dev = &sh->dev[i];
2187 if ((dev->towrite || i == sh->pd_idx) &&
2188 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002189 !(test_bit(R5_UPTODATE, &dev->flags) ||
2190 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002191 test_bit(R5_Insync, &dev->flags)) {
2192 if (
2193 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002194 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002195 "%d for r-m-w\n", i);
2196 set_bit(R5_LOCKED, &dev->flags);
2197 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002198 if (!test_and_set_bit(
2199 STRIPE_OP_IO, &sh->ops.pending))
2200 sh->ops.count++;
Dan Williamsa4456852007-07-09 11:56:43 -07002201 s->locked++;
2202 } else {
2203 set_bit(STRIPE_DELAYED, &sh->state);
2204 set_bit(STRIPE_HANDLE, &sh->state);
2205 }
2206 }
2207 }
2208 if (rcw <= rmw && rcw > 0)
2209 /* want reconstruct write, but need to get some data */
2210 for (i = disks; i--; ) {
2211 struct r5dev *dev = &sh->dev[i];
2212 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2213 i != sh->pd_idx &&
2214 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002215 !(test_bit(R5_UPTODATE, &dev->flags) ||
2216 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002217 test_bit(R5_Insync, &dev->flags)) {
2218 if (
2219 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002220 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002221 "%d for Reconstruct\n", i);
2222 set_bit(R5_LOCKED, &dev->flags);
2223 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002224 if (!test_and_set_bit(
2225 STRIPE_OP_IO, &sh->ops.pending))
2226 sh->ops.count++;
Dan Williamsa4456852007-07-09 11:56:43 -07002227 s->locked++;
2228 } else {
2229 set_bit(STRIPE_DELAYED, &sh->state);
2230 set_bit(STRIPE_HANDLE, &sh->state);
2231 }
2232 }
2233 }
2234 /* now if nothing is locked, and if we have enough data,
2235 * we can start a write request
2236 */
Dan Williamsf38e1212007-01-02 13:52:30 -07002237 /* since handle_stripe can be called at any time we need to handle the
2238 * case where a compute block operation has been submitted and then a
2239 * subsequent call wants to start a write request. raid5_run_ops only
2240 * handles the case where compute block and postxor are requested
2241 * simultaneously. If this is not the case then new writes need to be
2242 * held off until the compute completes.
2243 */
2244 if ((s->req_compute ||
2245 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) &&
2246 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2247 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
Dan Williamse33129d2007-01-02 13:52:30 -07002248 s->locked += handle_write_operations5(sh, rcw == 0, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002249}
2250
2251static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
2252 struct stripe_head *sh, struct stripe_head_state *s,
2253 struct r6_state *r6s, int disks)
2254{
2255 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
2256 int qd_idx = r6s->qd_idx;
2257 for (i = disks; i--; ) {
2258 struct r5dev *dev = &sh->dev[i];
2259 /* Would I have to read this buffer for reconstruct_write */
2260 if (!test_bit(R5_OVERWRITE, &dev->flags)
2261 && i != pd_idx && i != qd_idx
2262 && (!test_bit(R5_LOCKED, &dev->flags)
2263 ) &&
2264 !test_bit(R5_UPTODATE, &dev->flags)) {
2265 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2266 else {
Dan Williams45b42332007-07-09 11:56:43 -07002267 pr_debug("raid6: must_compute: "
Dan Williamsa4456852007-07-09 11:56:43 -07002268 "disk %d flags=%#lx\n", i, dev->flags);
2269 must_compute++;
2270 }
2271 }
2272 }
Dan Williams45b42332007-07-09 11:56:43 -07002273 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002274 (unsigned long long)sh->sector, rcw, must_compute);
2275 set_bit(STRIPE_HANDLE, &sh->state);
2276
2277 if (rcw > 0)
2278 /* want reconstruct write, but need to get some data */
2279 for (i = disks; i--; ) {
2280 struct r5dev *dev = &sh->dev[i];
2281 if (!test_bit(R5_OVERWRITE, &dev->flags)
2282 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2283 && !test_bit(R5_LOCKED, &dev->flags) &&
2284 !test_bit(R5_UPTODATE, &dev->flags) &&
2285 test_bit(R5_Insync, &dev->flags)) {
2286 if (
2287 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002288 pr_debug("Read_old stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002289 "block %d for Reconstruct\n",
2290 (unsigned long long)sh->sector, i);
2291 set_bit(R5_LOCKED, &dev->flags);
2292 set_bit(R5_Wantread, &dev->flags);
2293 s->locked++;
2294 } else {
Dan Williams45b42332007-07-09 11:56:43 -07002295 pr_debug("Request delayed stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002296 "block %d for Reconstruct\n",
2297 (unsigned long long)sh->sector, i);
2298 set_bit(STRIPE_DELAYED, &sh->state);
2299 set_bit(STRIPE_HANDLE, &sh->state);
2300 }
2301 }
2302 }
2303 /* now if nothing is locked, and if we have enough data, we can start a
2304 * write request
2305 */
2306 if (s->locked == 0 && rcw == 0 &&
2307 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2308 if (must_compute > 0) {
2309 /* We have failed blocks and need to compute them */
2310 switch (s->failed) {
2311 case 0:
2312 BUG();
2313 case 1:
2314 compute_block_1(sh, r6s->failed_num[0], 0);
2315 break;
2316 case 2:
2317 compute_block_2(sh, r6s->failed_num[0],
2318 r6s->failed_num[1]);
2319 break;
2320 default: /* This request should have been failed? */
2321 BUG();
2322 }
2323 }
2324
Dan Williams45b42332007-07-09 11:56:43 -07002325 pr_debug("Computing parity for stripe %llu\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002326 (unsigned long long)sh->sector);
2327 compute_parity6(sh, RECONSTRUCT_WRITE);
2328 /* now every locked buffer is ready to be written */
2329 for (i = disks; i--; )
2330 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
Dan Williams45b42332007-07-09 11:56:43 -07002331 pr_debug("Writing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002332 (unsigned long long)sh->sector, i);
2333 s->locked++;
2334 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2335 }
2336 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2337 set_bit(STRIPE_INSYNC, &sh->state);
2338
2339 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2340 atomic_dec(&conf->preread_active_stripes);
2341 if (atomic_read(&conf->preread_active_stripes) <
2342 IO_THRESHOLD)
2343 md_wakeup_thread(conf->mddev->thread);
2344 }
2345 }
2346}
2347
2348static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2349 struct stripe_head_state *s, int disks)
2350{
2351 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williamse89f8962007-01-02 13:52:31 -07002352 /* Take one of the following actions:
2353 * 1/ start a check parity operation if (uptodate == disks)
2354 * 2/ finish a check parity operation and act on the result
2355 * 3/ skip to the writeback section if we previously
2356 * initiated a recovery operation
2357 */
2358 if (s->failed == 0 &&
2359 !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2360 if (!test_and_set_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
2361 BUG_ON(s->uptodate != disks);
2362 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2363 sh->ops.count++;
2364 s->uptodate--;
2365 } else if (
2366 test_and_clear_bit(STRIPE_OP_CHECK, &sh->ops.complete)) {
2367 clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
2368 clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
2369
2370 if (sh->ops.zero_sum_result == 0)
2371 /* parity is correct (on disc,
2372 * not in buffer any more)
2373 */
Dan Williamsa4456852007-07-09 11:56:43 -07002374 set_bit(STRIPE_INSYNC, &sh->state);
2375 else {
Dan Williamse89f8962007-01-02 13:52:31 -07002376 conf->mddev->resync_mismatches +=
2377 STRIPE_SECTORS;
2378 if (test_bit(
2379 MD_RECOVERY_CHECK, &conf->mddev->recovery))
2380 /* don't try to repair!! */
2381 set_bit(STRIPE_INSYNC, &sh->state);
2382 else {
2383 set_bit(STRIPE_OP_COMPUTE_BLK,
2384 &sh->ops.pending);
2385 set_bit(STRIPE_OP_MOD_REPAIR_PD,
2386 &sh->ops.pending);
2387 set_bit(R5_Wantcompute,
2388 &sh->dev[sh->pd_idx].flags);
2389 sh->ops.target = sh->pd_idx;
2390 sh->ops.count++;
2391 s->uptodate++;
2392 }
Dan Williamsa4456852007-07-09 11:56:43 -07002393 }
2394 }
2395 }
Dan Williamse89f8962007-01-02 13:52:31 -07002396
2397 /* check if we can clear a parity disk reconstruct */
2398 if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
2399 test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2400
2401 clear_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending);
2402 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
2403 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
2404 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
2405 }
2406
2407 /* Wait for check parity and compute block operations to complete
2408 * before write-back
2409 */
2410 if (!test_bit(STRIPE_INSYNC, &sh->state) &&
2411 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending) &&
2412 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002413 struct r5dev *dev;
2414 /* either failed parity check, or recovery is happening */
2415 if (s->failed == 0)
2416 s->failed_num = sh->pd_idx;
2417 dev = &sh->dev[s->failed_num];
2418 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2419 BUG_ON(s->uptodate != disks);
2420
2421 set_bit(R5_LOCKED, &dev->flags);
2422 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002423 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2424 sh->ops.count++;
2425
Dan Williamsa4456852007-07-09 11:56:43 -07002426 clear_bit(STRIPE_DEGRADED, &sh->state);
2427 s->locked++;
2428 set_bit(STRIPE_INSYNC, &sh->state);
2429 }
2430}
2431
2432
2433static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2434 struct stripe_head_state *s,
2435 struct r6_state *r6s, struct page *tmp_page,
2436 int disks)
2437{
2438 int update_p = 0, update_q = 0;
2439 struct r5dev *dev;
2440 int pd_idx = sh->pd_idx;
2441 int qd_idx = r6s->qd_idx;
2442
2443 set_bit(STRIPE_HANDLE, &sh->state);
2444
2445 BUG_ON(s->failed > 2);
2446 BUG_ON(s->uptodate < disks);
2447 /* Want to check and possibly repair P and Q.
2448 * However there could be one 'failed' device, in which
2449 * case we can only check one of them, possibly using the
2450 * other to generate missing data
2451 */
2452
2453 /* If !tmp_page, we cannot do the calculations,
2454 * but as we have set STRIPE_HANDLE, we will soon be called
2455 * by stripe_handle with a tmp_page - just wait until then.
2456 */
2457 if (tmp_page) {
2458 if (s->failed == r6s->q_failed) {
2459 /* The only possible failed device holds 'Q', so it
2460 * makes sense to check P (If anything else were failed,
2461 * we would have used P to recreate it).
2462 */
2463 compute_block_1(sh, pd_idx, 1);
2464 if (!page_is_zero(sh->dev[pd_idx].page)) {
2465 compute_block_1(sh, pd_idx, 0);
2466 update_p = 1;
2467 }
2468 }
2469 if (!r6s->q_failed && s->failed < 2) {
2470 /* q is not failed, and we didn't use it to generate
2471 * anything, so it makes sense to check it
2472 */
2473 memcpy(page_address(tmp_page),
2474 page_address(sh->dev[qd_idx].page),
2475 STRIPE_SIZE);
2476 compute_parity6(sh, UPDATE_PARITY);
2477 if (memcmp(page_address(tmp_page),
2478 page_address(sh->dev[qd_idx].page),
2479 STRIPE_SIZE) != 0) {
2480 clear_bit(STRIPE_INSYNC, &sh->state);
2481 update_q = 1;
2482 }
2483 }
2484 if (update_p || update_q) {
2485 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2486 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2487 /* don't try to repair!! */
2488 update_p = update_q = 0;
2489 }
2490
2491 /* now write out any block on a failed drive,
2492 * or P or Q if they need it
2493 */
2494
2495 if (s->failed == 2) {
2496 dev = &sh->dev[r6s->failed_num[1]];
2497 s->locked++;
2498 set_bit(R5_LOCKED, &dev->flags);
2499 set_bit(R5_Wantwrite, &dev->flags);
2500 }
2501 if (s->failed >= 1) {
2502 dev = &sh->dev[r6s->failed_num[0]];
2503 s->locked++;
2504 set_bit(R5_LOCKED, &dev->flags);
2505 set_bit(R5_Wantwrite, &dev->flags);
2506 }
2507
2508 if (update_p) {
2509 dev = &sh->dev[pd_idx];
2510 s->locked++;
2511 set_bit(R5_LOCKED, &dev->flags);
2512 set_bit(R5_Wantwrite, &dev->flags);
2513 }
2514 if (update_q) {
2515 dev = &sh->dev[qd_idx];
2516 s->locked++;
2517 set_bit(R5_LOCKED, &dev->flags);
2518 set_bit(R5_Wantwrite, &dev->flags);
2519 }
2520 clear_bit(STRIPE_DEGRADED, &sh->state);
2521
2522 set_bit(STRIPE_INSYNC, &sh->state);
2523 }
2524}
2525
2526static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2527 struct r6_state *r6s)
2528{
2529 int i;
2530
2531 /* We have read all the blocks in this stripe and now we need to
2532 * copy some of them into a target stripe for expand.
2533 */
Dan Williamsf0a50d32007-01-02 13:52:31 -07002534 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsa4456852007-07-09 11:56:43 -07002535 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2536 for (i = 0; i < sh->disks; i++)
NeilBrowna2e08552007-09-11 15:23:36 -07002537 if (i != sh->pd_idx && (!r6s || i != r6s->qd_idx)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002538 int dd_idx, pd_idx, j;
2539 struct stripe_head *sh2;
2540
2541 sector_t bn = compute_blocknr(sh, i);
2542 sector_t s = raid5_compute_sector(bn, conf->raid_disks,
2543 conf->raid_disks -
2544 conf->max_degraded, &dd_idx,
2545 &pd_idx, conf);
2546 sh2 = get_active_stripe(conf, s, conf->raid_disks,
2547 pd_idx, 1);
2548 if (sh2 == NULL)
2549 /* so far only the early blocks of this stripe
2550 * have been requested. When later blocks
2551 * get requested, we will try again
2552 */
2553 continue;
2554 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2555 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2556 /* must have already done this block */
2557 release_stripe(sh2);
2558 continue;
2559 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002560
2561 /* place all the copies on one channel */
2562 tx = async_memcpy(sh2->dev[dd_idx].page,
2563 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2564 ASYNC_TX_DEP_ACK, tx, NULL, NULL);
2565
Dan Williamsa4456852007-07-09 11:56:43 -07002566 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2567 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2568 for (j = 0; j < conf->raid_disks; j++)
2569 if (j != sh2->pd_idx &&
NeilBrowna2e08552007-09-11 15:23:36 -07002570 (!r6s || j != raid6_next_disk(sh2->pd_idx,
2571 sh2->disks)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002572 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2573 break;
2574 if (j == conf->raid_disks) {
2575 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2576 set_bit(STRIPE_HANDLE, &sh2->state);
2577 }
2578 release_stripe(sh2);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002579
Dan Williamsa4456852007-07-09 11:56:43 -07002580 }
NeilBrowna2e08552007-09-11 15:23:36 -07002581 /* done submitting copies, wait for them to complete */
2582 if (tx) {
2583 async_tx_ack(tx);
2584 dma_wait_for_async_tx(tx);
2585 }
Dan Williamsa4456852007-07-09 11:56:43 -07002586}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002587
2588/*
2589 * handle_stripe - do things to a stripe.
2590 *
2591 * We lock the stripe and then examine the state of various bits
2592 * to see what needs to be done.
2593 * Possible results:
2594 * return some read request which now have data
2595 * return some write requests which are safely on disc
2596 * schedule a read on some buffers
2597 * schedule a write of some buffers
2598 * return confirmation of parity correctness
2599 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002600 * buffers are taken off read_list or write_list, and bh_cache buffers
2601 * get BH_Lock set before the stripe lock is released.
2602 *
2603 */
Dan Williamsa4456852007-07-09 11:56:43 -07002604
NeilBrown16a53ec2006-06-26 00:27:38 -07002605static void handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002606{
2607 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa4456852007-07-09 11:56:43 -07002608 int disks = sh->disks, i;
2609 struct bio *return_bi = NULL;
2610 struct stripe_head_state s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002611 struct r5dev *dev;
Dan Williamsd84e0f12007-01-02 13:52:30 -07002612 unsigned long pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002613
Dan Williamsa4456852007-07-09 11:56:43 -07002614 memset(&s, 0, sizeof(s));
Dan Williamsd84e0f12007-01-02 13:52:30 -07002615 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d "
2616 "ops=%lx:%lx:%lx\n", (unsigned long long)sh->sector, sh->state,
2617 atomic_read(&sh->count), sh->pd_idx,
2618 sh->ops.pending, sh->ops.ack, sh->ops.complete);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002619
2620 spin_lock(&sh->lock);
2621 clear_bit(STRIPE_HANDLE, &sh->state);
2622 clear_bit(STRIPE_DELAYED, &sh->state);
2623
Dan Williamsa4456852007-07-09 11:56:43 -07002624 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2625 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2626 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002627 /* Now to look around and see what can be done */
2628
Neil Browndef6ae22007-11-05 14:51:02 -08002629 /* clean-up completed biofill operations */
2630 if (test_bit(STRIPE_OP_BIOFILL, &sh->ops.complete)) {
2631 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.pending);
2632 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.ack);
2633 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
2634 }
2635
NeilBrown9910f162006-01-06 00:20:24 -08002636 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002637 for (i=disks; i--; ) {
2638 mdk_rdev_t *rdev;
Dan Williamsa4456852007-07-09 11:56:43 -07002639 struct r5dev *dev = &sh->dev[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002640 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002641
Dan Williamsb5e98d62007-01-02 13:52:31 -07002642 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2643 "written %p\n", i, dev->flags, dev->toread, dev->read,
2644 dev->towrite, dev->written);
2645
2646 /* maybe we can request a biofill operation
2647 *
2648 * new wantfill requests are only permitted while
2649 * STRIPE_OP_BIOFILL is clear
2650 */
2651 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
2652 !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
2653 set_bit(R5_Wantfill, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002654
2655 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002656 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2657 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williamsf38e1212007-01-02 13:52:30 -07002658 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002659
Dan Williamsb5e98d62007-01-02 13:52:31 -07002660 if (test_bit(R5_Wantfill, &dev->flags))
2661 s.to_fill++;
2662 else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07002663 s.to_read++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002664 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002665 s.to_write++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002666 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002667 s.non_overwrite++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002668 }
Dan Williamsa4456852007-07-09 11:56:43 -07002669 if (dev->written)
2670 s.written++;
NeilBrown9910f162006-01-06 00:20:24 -08002671 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08002672 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08002673 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08002674 clear_bit(R5_ReadError, &dev->flags);
2675 clear_bit(R5_ReWrite, &dev->flags);
2676 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002677 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002678 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002679 s.failed++;
2680 s.failed_num = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002681 } else
2682 set_bit(R5_Insync, &dev->flags);
2683 }
NeilBrown9910f162006-01-06 00:20:24 -08002684 rcu_read_unlock();
Dan Williamsb5e98d62007-01-02 13:52:31 -07002685
2686 if (s.to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
2687 sh->ops.count++;
2688
Dan Williams45b42332007-07-09 11:56:43 -07002689 pr_debug("locked=%d uptodate=%d to_read=%d"
Linus Torvalds1da177e2005-04-16 15:20:36 -07002690 " to_write=%d failed=%d failed_num=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002691 s.locked, s.uptodate, s.to_read, s.to_write,
2692 s.failed, s.failed_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002693 /* check if the array has lost two devices and, if so, some requests might
2694 * need to be failed
2695 */
Dan Williamsa4456852007-07-09 11:56:43 -07002696 if (s.failed > 1 && s.to_read+s.to_write+s.written)
2697 handle_requests_to_failed_array(conf, sh, &s, disks,
2698 &return_bi);
2699 if (s.failed > 1 && s.syncing) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002700 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2701 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002702 s.syncing = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002703 }
2704
2705 /* might be able to return some write requests if the parity block
2706 * is safe, or on a failed drive
2707 */
2708 dev = &sh->dev[sh->pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07002709 if ( s.written &&
2710 ((test_bit(R5_Insync, &dev->flags) &&
2711 !test_bit(R5_LOCKED, &dev->flags) &&
2712 test_bit(R5_UPTODATE, &dev->flags)) ||
2713 (s.failed == 1 && s.failed_num == sh->pd_idx)))
2714 handle_completed_write_requests(conf, sh, disks, &return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715
2716 /* Now we might consider reading some blocks, either to check/generate
2717 * parity, or to satisfy requests
2718 * or to load a block that is being partially written.
2719 */
Dan Williamsa4456852007-07-09 11:56:43 -07002720 if (s.to_read || s.non_overwrite ||
Dan Williamsf38e1212007-01-02 13:52:30 -07002721 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding ||
2722 test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002723 handle_issuing_new_read_requests5(sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002724
Dan Williamse33129d2007-01-02 13:52:30 -07002725 /* Now we check to see if any write operations have recently
2726 * completed
2727 */
2728
2729 /* leave prexor set until postxor is done, allows us to distinguish
2730 * a rmw from a rcw during biodrain
2731 */
2732 if (test_bit(STRIPE_OP_PREXOR, &sh->ops.complete) &&
2733 test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
2734
2735 clear_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
2736 clear_bit(STRIPE_OP_PREXOR, &sh->ops.ack);
2737 clear_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
2738
2739 for (i = disks; i--; )
2740 clear_bit(R5_Wantprexor, &sh->dev[i].flags);
2741 }
2742
2743 /* if only POSTXOR is set then this is an 'expand' postxor */
2744 if (test_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete) &&
2745 test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
2746
2747 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
2748 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.ack);
2749 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
2750
2751 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
2752 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
2753 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
2754
2755 /* All the 'written' buffers and the parity block are ready to
2756 * be written back to disk
2757 */
2758 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
2759 for (i = disks; i--; ) {
2760 dev = &sh->dev[i];
2761 if (test_bit(R5_LOCKED, &dev->flags) &&
2762 (i == sh->pd_idx || dev->written)) {
2763 pr_debug("Writing block %d\n", i);
2764 set_bit(R5_Wantwrite, &dev->flags);
2765 if (!test_and_set_bit(
2766 STRIPE_OP_IO, &sh->ops.pending))
2767 sh->ops.count++;
2768 if (!test_bit(R5_Insync, &dev->flags) ||
2769 (i == sh->pd_idx && s.failed == 0))
2770 set_bit(STRIPE_INSYNC, &sh->state);
2771 }
2772 }
2773 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2774 atomic_dec(&conf->preread_active_stripes);
2775 if (atomic_read(&conf->preread_active_stripes) <
2776 IO_THRESHOLD)
2777 md_wakeup_thread(conf->mddev->thread);
2778 }
2779 }
2780
2781 /* Now to consider new write requests and what else, if anything
2782 * should be read. We do not handle new writes when:
2783 * 1/ A 'write' operation (copy+xor) is already in flight.
2784 * 2/ A 'check' operation is in flight, as it may clobber the parity
2785 * block.
2786 */
2787 if (s.to_write && !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending) &&
2788 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002789 handle_issuing_new_write_requests5(conf, sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002790
2791 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamse89f8962007-01-02 13:52:31 -07002792 * Any reads will already have been scheduled, so we just see if enough
2793 * data is available. The parity check is held off while parity
2794 * dependent operations are in flight.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002795 */
Dan Williamse89f8962007-01-02 13:52:31 -07002796 if ((s.syncing && s.locked == 0 &&
2797 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending) &&
2798 !test_bit(STRIPE_INSYNC, &sh->state)) ||
2799 test_bit(STRIPE_OP_CHECK, &sh->ops.pending) ||
2800 test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002801 handle_parity_checks5(conf, sh, &s, disks);
Dan Williamse89f8962007-01-02 13:52:31 -07002802
Dan Williamsa4456852007-07-09 11:56:43 -07002803 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002804 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2805 clear_bit(STRIPE_SYNCING, &sh->state);
2806 }
NeilBrown4e5314b2005-11-08 21:39:22 -08002807
2808 /* If the failed drive is just a ReadError, then we might need to progress
2809 * the repair/check process
2810 */
Dan Williamsa4456852007-07-09 11:56:43 -07002811 if (s.failed == 1 && !conf->mddev->ro &&
2812 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2813 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2814 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002815 ) {
Dan Williamsa4456852007-07-09 11:56:43 -07002816 dev = &sh->dev[s.failed_num];
NeilBrown4e5314b2005-11-08 21:39:22 -08002817 if (!test_bit(R5_ReWrite, &dev->flags)) {
2818 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002819 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2820 sh->ops.count++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002821 set_bit(R5_ReWrite, &dev->flags);
2822 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002823 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002824 } else {
2825 /* let's read it back */
2826 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002827 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2828 sh->ops.count++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002829 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002830 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002831 }
2832 }
2833
Dan Williamsf0a50d32007-01-02 13:52:31 -07002834 /* Finish postxor operations initiated by the expansion
2835 * process
2836 */
2837 if (test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete) &&
2838 !test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending)) {
2839
2840 clear_bit(STRIPE_EXPANDING, &sh->state);
2841
2842 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
2843 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
2844 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
2845
2846 for (i = conf->raid_disks; i--; ) {
2847 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2848 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2849 sh->ops.count++;
2850 }
2851 }
2852
2853 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
2854 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002855 /* Need to write out all blocks after computing parity */
2856 sh->disks = conf->raid_disks;
Dan Williamsf0a50d32007-01-02 13:52:31 -07002857 sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
2858 conf->raid_disks);
NeilBrowna2e08552007-09-11 15:23:36 -07002859 s.locked += handle_write_operations5(sh, 1, 1);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002860 } else if (s.expanded &&
2861 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002862 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08002863 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002864 wake_up(&conf->wait_for_overlap);
2865 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2866 }
2867
Dan Williams0f94e872008-01-08 15:32:53 -08002868 if (s.expanding && s.locked == 0 &&
2869 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002870 handle_stripe_expansion(conf, sh, NULL);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002871
Dan Williamsd84e0f12007-01-02 13:52:30 -07002872 if (sh->ops.count)
2873 pending = get_stripe_work(sh);
2874
Linus Torvalds1da177e2005-04-16 15:20:36 -07002875 spin_unlock(&sh->lock);
2876
Dan Williamsd84e0f12007-01-02 13:52:30 -07002877 if (pending)
2878 raid5_run_ops(sh, pending);
2879
Dan Williamsa4456852007-07-09 11:56:43 -07002880 return_io(return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002881
Linus Torvalds1da177e2005-04-16 15:20:36 -07002882}
2883
NeilBrown16a53ec2006-06-26 00:27:38 -07002884static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
2885{
2886 raid6_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08002887 int disks = sh->disks;
Dan Williamsa4456852007-07-09 11:56:43 -07002888 struct bio *return_bi = NULL;
2889 int i, pd_idx = sh->pd_idx;
2890 struct stripe_head_state s;
2891 struct r6_state r6s;
NeilBrown16a53ec2006-06-26 00:27:38 -07002892 struct r5dev *dev, *pdev, *qdev;
NeilBrown16a53ec2006-06-26 00:27:38 -07002893
Dan Williamsa4456852007-07-09 11:56:43 -07002894 r6s.qd_idx = raid6_next_disk(pd_idx, disks);
Dan Williams45b42332007-07-09 11:56:43 -07002895 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
Dan Williamsa4456852007-07-09 11:56:43 -07002896 "pd_idx=%d, qd_idx=%d\n",
2897 (unsigned long long)sh->sector, sh->state,
2898 atomic_read(&sh->count), pd_idx, r6s.qd_idx);
2899 memset(&s, 0, sizeof(s));
NeilBrown16a53ec2006-06-26 00:27:38 -07002900
2901 spin_lock(&sh->lock);
2902 clear_bit(STRIPE_HANDLE, &sh->state);
2903 clear_bit(STRIPE_DELAYED, &sh->state);
2904
Dan Williamsa4456852007-07-09 11:56:43 -07002905 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2906 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2907 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrown16a53ec2006-06-26 00:27:38 -07002908 /* Now to look around and see what can be done */
2909
2910 rcu_read_lock();
2911 for (i=disks; i--; ) {
2912 mdk_rdev_t *rdev;
2913 dev = &sh->dev[i];
2914 clear_bit(R5_Insync, &dev->flags);
2915
Dan Williams45b42332007-07-09 11:56:43 -07002916 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07002917 i, dev->flags, dev->toread, dev->towrite, dev->written);
2918 /* maybe we can reply to a read */
2919 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
2920 struct bio *rbi, *rbi2;
Dan Williams45b42332007-07-09 11:56:43 -07002921 pr_debug("Return read for disc %d\n", i);
NeilBrown16a53ec2006-06-26 00:27:38 -07002922 spin_lock_irq(&conf->device_lock);
2923 rbi = dev->toread;
2924 dev->toread = NULL;
2925 if (test_and_clear_bit(R5_Overlap, &dev->flags))
2926 wake_up(&conf->wait_for_overlap);
2927 spin_unlock_irq(&conf->device_lock);
2928 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2929 copy_data(0, rbi, dev->page, dev->sector);
2930 rbi2 = r5_next_bio(rbi, dev->sector);
2931 spin_lock_irq(&conf->device_lock);
2932 if (--rbi->bi_phys_segments == 0) {
2933 rbi->bi_next = return_bi;
2934 return_bi = rbi;
2935 }
2936 spin_unlock_irq(&conf->device_lock);
2937 rbi = rbi2;
2938 }
2939 }
2940
2941 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002942 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2943 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002944
2945
Dan Williamsa4456852007-07-09 11:56:43 -07002946 if (dev->toread)
2947 s.to_read++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002948 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002949 s.to_write++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002950 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002951 s.non_overwrite++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002952 }
Dan Williamsa4456852007-07-09 11:56:43 -07002953 if (dev->written)
2954 s.written++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002955 rdev = rcu_dereference(conf->disks[i].rdev);
2956 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
2957 /* The ReadError flag will just be confusing now */
2958 clear_bit(R5_ReadError, &dev->flags);
2959 clear_bit(R5_ReWrite, &dev->flags);
2960 }
2961 if (!rdev || !test_bit(In_sync, &rdev->flags)
2962 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002963 if (s.failed < 2)
2964 r6s.failed_num[s.failed] = i;
2965 s.failed++;
NeilBrown16a53ec2006-06-26 00:27:38 -07002966 } else
2967 set_bit(R5_Insync, &dev->flags);
2968 }
2969 rcu_read_unlock();
Dan Williams45b42332007-07-09 11:56:43 -07002970 pr_debug("locked=%d uptodate=%d to_read=%d"
NeilBrown16a53ec2006-06-26 00:27:38 -07002971 " to_write=%d failed=%d failed_num=%d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002972 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
2973 r6s.failed_num[0], r6s.failed_num[1]);
2974 /* check if the array has lost >2 devices and, if so, some requests
2975 * might need to be failed
NeilBrown16a53ec2006-06-26 00:27:38 -07002976 */
Dan Williamsa4456852007-07-09 11:56:43 -07002977 if (s.failed > 2 && s.to_read+s.to_write+s.written)
2978 handle_requests_to_failed_array(conf, sh, &s, disks,
2979 &return_bi);
2980 if (s.failed > 2 && s.syncing) {
NeilBrown16a53ec2006-06-26 00:27:38 -07002981 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2982 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002983 s.syncing = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07002984 }
2985
2986 /*
2987 * might be able to return some write requests if the parity blocks
2988 * are safe, or on a failed drive
2989 */
2990 pdev = &sh->dev[pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07002991 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
2992 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
2993 qdev = &sh->dev[r6s.qd_idx];
2994 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == r6s.qd_idx)
2995 || (s.failed >= 2 && r6s.failed_num[1] == r6s.qd_idx);
NeilBrown16a53ec2006-06-26 00:27:38 -07002996
Dan Williamsa4456852007-07-09 11:56:43 -07002997 if ( s.written &&
2998 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07002999 && !test_bit(R5_LOCKED, &pdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003000 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3001 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003002 && !test_bit(R5_LOCKED, &qdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003003 && test_bit(R5_UPTODATE, &qdev->flags)))))
3004 handle_completed_write_requests(conf, sh, disks, &return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003005
3006 /* Now we might consider reading some blocks, either to check/generate
3007 * parity, or to satisfy requests
3008 * or to load a block that is being partially written.
3009 */
Dan Williamsa4456852007-07-09 11:56:43 -07003010 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3011 (s.syncing && (s.uptodate < disks)) || s.expanding)
3012 handle_issuing_new_read_requests6(sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003013
3014 /* now to consider writing and what else, if anything should be read */
Dan Williamsa4456852007-07-09 11:56:43 -07003015 if (s.to_write)
3016 handle_issuing_new_write_requests6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003017
3018 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamsa4456852007-07-09 11:56:43 -07003019 * Any reads will already have been scheduled, so we just see if enough
3020 * data is available
NeilBrown16a53ec2006-06-26 00:27:38 -07003021 */
Dan Williamsa4456852007-07-09 11:56:43 -07003022 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
3023 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003024
Dan Williamsa4456852007-07-09 11:56:43 -07003025 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003026 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3027 clear_bit(STRIPE_SYNCING, &sh->state);
3028 }
3029
3030 /* If the failed drives are just a ReadError, then we might need
3031 * to progress the repair/check process
3032 */
Dan Williamsa4456852007-07-09 11:56:43 -07003033 if (s.failed <= 2 && !conf->mddev->ro)
3034 for (i = 0; i < s.failed; i++) {
3035 dev = &sh->dev[r6s.failed_num[i]];
NeilBrown16a53ec2006-06-26 00:27:38 -07003036 if (test_bit(R5_ReadError, &dev->flags)
3037 && !test_bit(R5_LOCKED, &dev->flags)
3038 && test_bit(R5_UPTODATE, &dev->flags)
3039 ) {
3040 if (!test_bit(R5_ReWrite, &dev->flags)) {
3041 set_bit(R5_Wantwrite, &dev->flags);
3042 set_bit(R5_ReWrite, &dev->flags);
3043 set_bit(R5_LOCKED, &dev->flags);
3044 } else {
3045 /* let's read it back */
3046 set_bit(R5_Wantread, &dev->flags);
3047 set_bit(R5_LOCKED, &dev->flags);
3048 }
3049 }
3050 }
NeilBrownf4168852007-02-28 20:11:53 -08003051
Dan Williamsa4456852007-07-09 11:56:43 -07003052 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
NeilBrownf4168852007-02-28 20:11:53 -08003053 /* Need to write out all blocks after computing P&Q */
3054 sh->disks = conf->raid_disks;
3055 sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
3056 conf->raid_disks);
3057 compute_parity6(sh, RECONSTRUCT_WRITE);
3058 for (i = conf->raid_disks ; i-- ; ) {
3059 set_bit(R5_LOCKED, &sh->dev[i].flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003060 s.locked++;
NeilBrownf4168852007-02-28 20:11:53 -08003061 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3062 }
3063 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003064 } else if (s.expanded) {
NeilBrownf4168852007-02-28 20:11:53 -08003065 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3066 atomic_dec(&conf->reshape_stripes);
3067 wake_up(&conf->wait_for_overlap);
3068 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3069 }
3070
Dan Williams0f94e872008-01-08 15:32:53 -08003071 if (s.expanding && s.locked == 0 &&
3072 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07003073 handle_stripe_expansion(conf, sh, &r6s);
NeilBrownf4168852007-02-28 20:11:53 -08003074
NeilBrown16a53ec2006-06-26 00:27:38 -07003075 spin_unlock(&sh->lock);
3076
Dan Williamsa4456852007-07-09 11:56:43 -07003077 return_io(return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003078
NeilBrown16a53ec2006-06-26 00:27:38 -07003079 for (i=disks; i-- ;) {
3080 int rw;
3081 struct bio *bi;
3082 mdk_rdev_t *rdev;
3083 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08003084 rw = WRITE;
NeilBrown16a53ec2006-06-26 00:27:38 -07003085 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08003086 rw = READ;
NeilBrown16a53ec2006-06-26 00:27:38 -07003087 else
3088 continue;
3089
3090 bi = &sh->dev[i].req;
3091
3092 bi->bi_rw = rw;
NeilBrown802ba062006-12-13 00:34:13 -08003093 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07003094 bi->bi_end_io = raid5_end_write_request;
3095 else
3096 bi->bi_end_io = raid5_end_read_request;
3097
3098 rcu_read_lock();
3099 rdev = rcu_dereference(conf->disks[i].rdev);
3100 if (rdev && test_bit(Faulty, &rdev->flags))
3101 rdev = NULL;
3102 if (rdev)
3103 atomic_inc(&rdev->nr_pending);
3104 rcu_read_unlock();
3105
3106 if (rdev) {
Dan Williamsa4456852007-07-09 11:56:43 -07003107 if (s.syncing || s.expanding || s.expanded)
NeilBrown16a53ec2006-06-26 00:27:38 -07003108 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
3109
3110 bi->bi_bdev = rdev->bdev;
Dan Williams45b42332007-07-09 11:56:43 -07003111 pr_debug("for %llu schedule op %ld on disc %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003112 (unsigned long long)sh->sector, bi->bi_rw, i);
3113 atomic_inc(&sh->count);
3114 bi->bi_sector = sh->sector + rdev->data_offset;
3115 bi->bi_flags = 1 << BIO_UPTODATE;
3116 bi->bi_vcnt = 1;
3117 bi->bi_max_vecs = 1;
3118 bi->bi_idx = 0;
3119 bi->bi_io_vec = &sh->dev[i].vec;
3120 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
3121 bi->bi_io_vec[0].bv_offset = 0;
3122 bi->bi_size = STRIPE_SIZE;
3123 bi->bi_next = NULL;
3124 if (rw == WRITE &&
3125 test_bit(R5_ReWrite, &sh->dev[i].flags))
3126 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
3127 generic_make_request(bi);
3128 } else {
NeilBrown802ba062006-12-13 00:34:13 -08003129 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07003130 set_bit(STRIPE_DEGRADED, &sh->state);
Dan Williams45b42332007-07-09 11:56:43 -07003131 pr_debug("skip op %ld on disc %d for sector %llu\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003132 bi->bi_rw, i, (unsigned long long)sh->sector);
3133 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3134 set_bit(STRIPE_HANDLE, &sh->state);
3135 }
3136 }
3137}
3138
3139static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
3140{
3141 if (sh->raid_conf->level == 6)
3142 handle_stripe6(sh, tmp_page);
3143 else
3144 handle_stripe5(sh);
3145}
3146
3147
3148
Arjan van de Ven858119e2006-01-14 13:20:43 -08003149static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003150{
3151 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3152 while (!list_empty(&conf->delayed_list)) {
3153 struct list_head *l = conf->delayed_list.next;
3154 struct stripe_head *sh;
3155 sh = list_entry(l, struct stripe_head, lru);
3156 list_del_init(l);
3157 clear_bit(STRIPE_DELAYED, &sh->state);
3158 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3159 atomic_inc(&conf->preread_active_stripes);
3160 list_add_tail(&sh->lru, &conf->handle_list);
3161 }
NeilBrown6ed30032008-02-06 01:40:00 -08003162 } else
3163 blk_plug_device(conf->mddev->queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003164}
3165
Arjan van de Ven858119e2006-01-14 13:20:43 -08003166static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07003167{
3168 /* device_lock is held */
3169 struct list_head head;
3170 list_add(&head, &conf->bitmap_list);
3171 list_del_init(&conf->bitmap_list);
3172 while (!list_empty(&head)) {
3173 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3174 list_del_init(&sh->lru);
3175 atomic_inc(&sh->count);
3176 __release_stripe(conf, sh);
3177 }
3178}
3179
Linus Torvalds1da177e2005-04-16 15:20:36 -07003180static void unplug_slaves(mddev_t *mddev)
3181{
3182 raid5_conf_t *conf = mddev_to_conf(mddev);
3183 int i;
3184
3185 rcu_read_lock();
3186 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08003187 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08003188 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +02003189 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003190
3191 atomic_inc(&rdev->nr_pending);
3192 rcu_read_unlock();
3193
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -05003194 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003195
3196 rdev_dec_pending(rdev, mddev);
3197 rcu_read_lock();
3198 }
3199 }
3200 rcu_read_unlock();
3201}
3202
Jens Axboe165125e2007-07-24 09:28:11 +02003203static void raid5_unplug_device(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003204{
3205 mddev_t *mddev = q->queuedata;
3206 raid5_conf_t *conf = mddev_to_conf(mddev);
3207 unsigned long flags;
3208
3209 spin_lock_irqsave(&conf->device_lock, flags);
3210
NeilBrown72626682005-09-09 16:23:54 -07003211 if (blk_remove_plug(q)) {
3212 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003213 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07003214 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003215 md_wakeup_thread(mddev->thread);
3216
3217 spin_unlock_irqrestore(&conf->device_lock, flags);
3218
3219 unplug_slaves(mddev);
3220}
3221
NeilBrownf022b2f2006-10-03 01:15:56 -07003222static int raid5_congested(void *data, int bits)
3223{
3224 mddev_t *mddev = data;
3225 raid5_conf_t *conf = mddev_to_conf(mddev);
3226
3227 /* No difference between reads and writes. Just check
3228 * how busy the stripe_cache is
3229 */
3230 if (conf->inactive_blocked)
3231 return 1;
3232 if (conf->quiesce)
3233 return 1;
3234 if (list_empty_careful(&conf->inactive_list))
3235 return 1;
3236
3237 return 0;
3238}
3239
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003240/* We want read requests to align with chunks where possible,
3241 * but write requests don't need to.
3242 */
Jens Axboe165125e2007-07-24 09:28:11 +02003243static int raid5_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003244{
3245 mddev_t *mddev = q->queuedata;
3246 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3247 int max;
3248 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3249 unsigned int bio_sectors = bio->bi_size >> 9;
3250
NeilBrown802ba062006-12-13 00:34:13 -08003251 if (bio_data_dir(bio) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003252 return biovec->bv_len; /* always allow writes to be mergeable */
3253
3254 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3255 if (max < 0) max = 0;
3256 if (max <= biovec->bv_len && bio_sectors == 0)
3257 return biovec->bv_len;
3258 else
3259 return max;
3260}
3261
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003262
3263static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3264{
3265 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3266 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3267 unsigned int bio_sectors = bio->bi_size >> 9;
3268
3269 return chunk_sectors >=
3270 ((sector & (chunk_sectors - 1)) + bio_sectors);
3271}
3272
3273/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003274 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3275 * later sampled by raid5d.
3276 */
3277static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3278{
3279 unsigned long flags;
3280
3281 spin_lock_irqsave(&conf->device_lock, flags);
3282
3283 bi->bi_next = conf->retry_read_aligned_list;
3284 conf->retry_read_aligned_list = bi;
3285
3286 spin_unlock_irqrestore(&conf->device_lock, flags);
3287 md_wakeup_thread(conf->mddev->thread);
3288}
3289
3290
3291static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3292{
3293 struct bio *bi;
3294
3295 bi = conf->retry_read_aligned;
3296 if (bi) {
3297 conf->retry_read_aligned = NULL;
3298 return bi;
3299 }
3300 bi = conf->retry_read_aligned_list;
3301 if(bi) {
Neil Brown387bb172007-02-08 14:20:29 -08003302 conf->retry_read_aligned_list = bi->bi_next;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003303 bi->bi_next = NULL;
3304 bi->bi_phys_segments = 1; /* biased count of active stripes */
3305 bi->bi_hw_segments = 0; /* count of processed stripes */
3306 }
3307
3308 return bi;
3309}
3310
3311
3312/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003313 * The "raid5_align_endio" should check if the read succeeded and if it
3314 * did, call bio_endio on the original bio (having bio_put the new bio
3315 * first).
3316 * If the read failed..
3317 */
NeilBrown6712ecf2007-09-27 12:47:43 +02003318static void raid5_align_endio(struct bio *bi, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003319{
3320 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003321 mddev_t *mddev;
3322 raid5_conf_t *conf;
3323 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3324 mdk_rdev_t *rdev;
3325
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003326 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003327
3328 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
3329 conf = mddev_to_conf(mddev);
3330 rdev = (void*)raid_bi->bi_next;
3331 raid_bi->bi_next = NULL;
3332
3333 rdev_dec_pending(rdev, conf->mddev);
3334
3335 if (!error && uptodate) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003336 bio_endio(raid_bi, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003337 if (atomic_dec_and_test(&conf->active_aligned_reads))
3338 wake_up(&conf->wait_for_stripe);
NeilBrown6712ecf2007-09-27 12:47:43 +02003339 return;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003340 }
3341
3342
Dan Williams45b42332007-07-09 11:56:43 -07003343 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003344
3345 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003346}
3347
Neil Brown387bb172007-02-08 14:20:29 -08003348static int bio_fits_rdev(struct bio *bi)
3349{
Jens Axboe165125e2007-07-24 09:28:11 +02003350 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
Neil Brown387bb172007-02-08 14:20:29 -08003351
3352 if ((bi->bi_size>>9) > q->max_sectors)
3353 return 0;
3354 blk_recount_segments(q, bi);
3355 if (bi->bi_phys_segments > q->max_phys_segments ||
3356 bi->bi_hw_segments > q->max_hw_segments)
3357 return 0;
3358
3359 if (q->merge_bvec_fn)
3360 /* it's too hard to apply the merge_bvec_fn at this stage,
3361 * just just give up
3362 */
3363 return 0;
3364
3365 return 1;
3366}
3367
3368
Jens Axboe165125e2007-07-24 09:28:11 +02003369static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003370{
3371 mddev_t *mddev = q->queuedata;
3372 raid5_conf_t *conf = mddev_to_conf(mddev);
3373 const unsigned int raid_disks = conf->raid_disks;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003374 const unsigned int data_disks = raid_disks - conf->max_degraded;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003375 unsigned int dd_idx, pd_idx;
3376 struct bio* align_bi;
3377 mdk_rdev_t *rdev;
3378
3379 if (!in_chunk_boundary(mddev, raid_bio)) {
Dan Williams45b42332007-07-09 11:56:43 -07003380 pr_debug("chunk_aligned_read : non aligned\n");
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003381 return 0;
3382 }
3383 /*
3384 * use bio_clone to make a copy of the bio
3385 */
3386 align_bi = bio_clone(raid_bio, GFP_NOIO);
3387 if (!align_bi)
3388 return 0;
3389 /*
3390 * set bi_end_io to a new function, and set bi_private to the
3391 * original bio.
3392 */
3393 align_bi->bi_end_io = raid5_align_endio;
3394 align_bi->bi_private = raid_bio;
3395 /*
3396 * compute position
3397 */
3398 align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector,
3399 raid_disks,
3400 data_disks,
3401 &dd_idx,
3402 &pd_idx,
3403 conf);
3404
3405 rcu_read_lock();
3406 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3407 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003408 atomic_inc(&rdev->nr_pending);
3409 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003410 raid_bio->bi_next = (void*)rdev;
3411 align_bi->bi_bdev = rdev->bdev;
3412 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3413 align_bi->bi_sector += rdev->data_offset;
3414
Neil Brown387bb172007-02-08 14:20:29 -08003415 if (!bio_fits_rdev(align_bi)) {
3416 /* too big in some way */
3417 bio_put(align_bi);
3418 rdev_dec_pending(rdev, mddev);
3419 return 0;
3420 }
3421
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003422 spin_lock_irq(&conf->device_lock);
3423 wait_event_lock_irq(conf->wait_for_stripe,
3424 conf->quiesce == 0,
3425 conf->device_lock, /* nothing */);
3426 atomic_inc(&conf->active_aligned_reads);
3427 spin_unlock_irq(&conf->device_lock);
3428
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003429 generic_make_request(align_bi);
3430 return 1;
3431 } else {
3432 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003433 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003434 return 0;
3435 }
3436}
3437
3438
Jens Axboe165125e2007-07-24 09:28:11 +02003439static int make_request(struct request_queue *q, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003440{
3441 mddev_t *mddev = q->queuedata;
3442 raid5_conf_t *conf = mddev_to_conf(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003443 unsigned int dd_idx, pd_idx;
3444 sector_t new_sector;
3445 sector_t logical_sector, last_sector;
3446 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01003447 const int rw = bio_data_dir(bi);
NeilBrownf6344752006-03-27 01:18:17 -08003448 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003449
NeilBrowne5dcdd82005-09-09 16:23:41 -07003450 if (unlikely(bio_barrier(bi))) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003451 bio_endio(bi, -EOPNOTSUPP);
NeilBrowne5dcdd82005-09-09 16:23:41 -07003452 return 0;
3453 }
3454
NeilBrown3d310eb2005-06-21 17:17:26 -07003455 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07003456
Jens Axboea3623572005-11-01 09:26:16 +01003457 disk_stat_inc(mddev->gendisk, ios[rw]);
3458 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003459
NeilBrown802ba062006-12-13 00:34:13 -08003460 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003461 mddev->reshape_position == MaxSector &&
3462 chunk_aligned_read(q,bi))
3463 return 0;
3464
Linus Torvalds1da177e2005-04-16 15:20:36 -07003465 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3466 last_sector = bi->bi_sector + (bi->bi_size>>9);
3467 bi->bi_next = NULL;
3468 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07003469
Linus Torvalds1da177e2005-04-16 15:20:36 -07003470 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3471 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07003472 int disks, data_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003473
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003474 retry:
NeilBrownb578d552006-03-27 01:18:12 -08003475 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003476 if (likely(conf->expand_progress == MaxSector))
3477 disks = conf->raid_disks;
3478 else {
NeilBrowndf8e7f72006-03-27 01:18:15 -08003479 /* spinlock is needed as expand_progress may be
3480 * 64bit on a 32bit platform, and so it might be
3481 * possible to see a half-updated value
3482 * Ofcourse expand_progress could change after
3483 * the lock is dropped, so once we get a reference
3484 * to the stripe that we think it is, we will have
3485 * to check again.
3486 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003487 spin_lock_irq(&conf->device_lock);
3488 disks = conf->raid_disks;
3489 if (logical_sector >= conf->expand_progress)
3490 disks = conf->previous_raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003491 else {
3492 if (logical_sector >= conf->expand_lo) {
3493 spin_unlock_irq(&conf->device_lock);
3494 schedule();
3495 goto retry;
3496 }
3497 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003498 spin_unlock_irq(&conf->device_lock);
3499 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003500 data_disks = disks - conf->max_degraded;
3501
3502 new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003503 &dd_idx, &pd_idx, conf);
Dan Williams45b42332007-07-09 11:56:43 -07003504 pr_debug("raid5: make_request, sector %llu logical %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07003505 (unsigned long long)new_sector,
3506 (unsigned long long)logical_sector);
3507
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003508 sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003509 if (sh) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003510 if (unlikely(conf->expand_progress != MaxSector)) {
3511 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08003512 * stripe, so we must do the range check again.
3513 * Expansion could still move past after this
3514 * test, but as we are holding a reference to
3515 * 'sh', we know that if that happens,
3516 * STRIPE_EXPANDING will get set and the expansion
3517 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003518 */
3519 int must_retry = 0;
3520 spin_lock_irq(&conf->device_lock);
3521 if (logical_sector < conf->expand_progress &&
3522 disks == conf->previous_raid_disks)
3523 /* mismatch, need to try again */
3524 must_retry = 1;
3525 spin_unlock_irq(&conf->device_lock);
3526 if (must_retry) {
3527 release_stripe(sh);
3528 goto retry;
3529 }
3530 }
NeilBrowne464eaf2006-03-27 01:18:14 -08003531 /* FIXME what if we get a false positive because these
3532 * are being updated.
3533 */
3534 if (logical_sector >= mddev->suspend_lo &&
3535 logical_sector < mddev->suspend_hi) {
3536 release_stripe(sh);
3537 schedule();
3538 goto retry;
3539 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003540
3541 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3542 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3543 /* Stripe is busy expanding or
3544 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07003545 * and wait a while
3546 */
3547 raid5_unplug_device(mddev->queue);
3548 release_stripe(sh);
3549 schedule();
3550 goto retry;
3551 }
3552 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown6ed30032008-02-06 01:40:00 -08003553 set_bit(STRIPE_HANDLE, &sh->state);
3554 clear_bit(STRIPE_DELAYED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003555 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003556 } else {
3557 /* cannot get stripe for read-ahead, just give-up */
3558 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3559 finish_wait(&conf->wait_for_overlap, &w);
3560 break;
3561 }
3562
3563 }
3564 spin_lock_irq(&conf->device_lock);
NeilBrownf6344752006-03-27 01:18:17 -08003565 remaining = --bi->bi_phys_segments;
3566 spin_unlock_irq(&conf->device_lock);
3567 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568
NeilBrown16a53ec2006-06-26 00:27:38 -07003569 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07003570 md_write_end(mddev);
NeilBrown6712ecf2007-09-27 12:47:43 +02003571
3572 bi->bi_end_io(bi,
NeilBrownc2b00852006-12-10 02:20:51 -08003573 test_bit(BIO_UPTODATE, &bi->bi_flags)
3574 ? 0 : -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003575 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003576 return 0;
3577}
3578
NeilBrown52c03292006-06-26 00:27:43 -07003579static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003580{
NeilBrown52c03292006-06-26 00:27:43 -07003581 /* reshaping is quite different to recovery/resync so it is
3582 * handled quite separately ... here.
3583 *
3584 * On each call to sync_request, we gather one chunk worth of
3585 * destination stripes and flag them as expanding.
3586 * Then we find all the source stripes and request reads.
3587 * As the reads complete, handle_stripe will copy the data
3588 * into the destination stripe and release that stripe.
3589 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003590 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3591 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08003592 int pd_idx;
3593 sector_t first_sector, last_sector;
NeilBrownf4168852007-02-28 20:11:53 -08003594 int raid_disks = conf->previous_raid_disks;
3595 int data_disks = raid_disks - conf->max_degraded;
3596 int new_data_disks = conf->raid_disks - conf->max_degraded;
NeilBrown52c03292006-06-26 00:27:43 -07003597 int i;
3598 int dd_idx;
3599 sector_t writepos, safepos, gap;
3600
3601 if (sector_nr == 0 &&
3602 conf->expand_progress != 0) {
3603 /* restarting in the middle, skip the initial sectors */
3604 sector_nr = conf->expand_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003605 sector_div(sector_nr, new_data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003606 *skipped = 1;
3607 return sector_nr;
3608 }
3609
3610 /* we update the metadata when there is more than 3Meg
3611 * in the block range (that is rather arbitrary, should
3612 * probably be time based) or when the data about to be
3613 * copied would over-write the source of the data at
3614 * the front of the range.
3615 * i.e. one new_stripe forward from expand_progress new_maps
3616 * to after where expand_lo old_maps to
3617 */
3618 writepos = conf->expand_progress +
NeilBrownf4168852007-02-28 20:11:53 -08003619 conf->chunk_size/512*(new_data_disks);
3620 sector_div(writepos, new_data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003621 safepos = conf->expand_lo;
NeilBrownf4168852007-02-28 20:11:53 -08003622 sector_div(safepos, data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003623 gap = conf->expand_progress - conf->expand_lo;
3624
3625 if (writepos >= safepos ||
NeilBrownf4168852007-02-28 20:11:53 -08003626 gap > (new_data_disks)*3000*2 /*3Meg*/) {
NeilBrown52c03292006-06-26 00:27:43 -07003627 /* Cannot proceed until we've updated the superblock... */
3628 wait_event(conf->wait_for_overlap,
3629 atomic_read(&conf->reshape_stripes)==0);
3630 mddev->reshape_position = conf->expand_progress;
NeilBrown850b2b42006-10-03 01:15:46 -07003631 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07003632 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07003633 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07003634 kthread_should_stop());
3635 spin_lock_irq(&conf->device_lock);
3636 conf->expand_lo = mddev->reshape_position;
3637 spin_unlock_irq(&conf->device_lock);
3638 wake_up(&conf->wait_for_overlap);
3639 }
3640
3641 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
3642 int j;
3643 int skipped = 0;
3644 pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
3645 sh = get_active_stripe(conf, sector_nr+i,
3646 conf->raid_disks, pd_idx, 0);
3647 set_bit(STRIPE_EXPANDING, &sh->state);
3648 atomic_inc(&conf->reshape_stripes);
3649 /* If any of this stripe is beyond the end of the old
3650 * array, then we need to zero those blocks
3651 */
3652 for (j=sh->disks; j--;) {
3653 sector_t s;
3654 if (j == sh->pd_idx)
3655 continue;
NeilBrownf4168852007-02-28 20:11:53 -08003656 if (conf->level == 6 &&
3657 j == raid6_next_disk(sh->pd_idx, sh->disks))
3658 continue;
NeilBrown52c03292006-06-26 00:27:43 -07003659 s = compute_blocknr(sh, j);
3660 if (s < (mddev->array_size<<1)) {
3661 skipped = 1;
3662 continue;
3663 }
3664 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3665 set_bit(R5_Expanded, &sh->dev[j].flags);
3666 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3667 }
3668 if (!skipped) {
3669 set_bit(STRIPE_EXPAND_READY, &sh->state);
3670 set_bit(STRIPE_HANDLE, &sh->state);
3671 }
3672 release_stripe(sh);
3673 }
3674 spin_lock_irq(&conf->device_lock);
NeilBrown6d3baf22007-03-05 00:30:44 -08003675 conf->expand_progress = (sector_nr + i) * new_data_disks;
NeilBrown52c03292006-06-26 00:27:43 -07003676 spin_unlock_irq(&conf->device_lock);
3677 /* Ok, those stripe are ready. We can start scheduling
3678 * reads on the source stripes.
3679 * The source stripes are determined by mapping the first and last
3680 * block on the destination stripes.
3681 */
NeilBrown52c03292006-06-26 00:27:43 -07003682 first_sector =
NeilBrownf4168852007-02-28 20:11:53 -08003683 raid5_compute_sector(sector_nr*(new_data_disks),
NeilBrown52c03292006-06-26 00:27:43 -07003684 raid_disks, data_disks,
3685 &dd_idx, &pd_idx, conf);
3686 last_sector =
3687 raid5_compute_sector((sector_nr+conf->chunk_size/512)
NeilBrownf4168852007-02-28 20:11:53 -08003688 *(new_data_disks) -1,
NeilBrown52c03292006-06-26 00:27:43 -07003689 raid_disks, data_disks,
3690 &dd_idx, &pd_idx, conf);
3691 if (last_sector >= (mddev->size<<1))
3692 last_sector = (mddev->size<<1)-1;
3693 while (first_sector <= last_sector) {
NeilBrownf4168852007-02-28 20:11:53 -08003694 pd_idx = stripe_to_pdidx(first_sector, conf,
3695 conf->previous_raid_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003696 sh = get_active_stripe(conf, first_sector,
3697 conf->previous_raid_disks, pd_idx, 0);
3698 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3699 set_bit(STRIPE_HANDLE, &sh->state);
3700 release_stripe(sh);
3701 first_sector += STRIPE_SECTORS;
3702 }
NeilBrownc6207272008-02-06 01:39:52 -08003703 /* If this takes us to the resync_max point where we have to pause,
3704 * then we need to write out the superblock.
3705 */
3706 sector_nr += conf->chunk_size>>9;
3707 if (sector_nr >= mddev->resync_max) {
3708 /* Cannot proceed until we've updated the superblock... */
3709 wait_event(conf->wait_for_overlap,
3710 atomic_read(&conf->reshape_stripes) == 0);
3711 mddev->reshape_position = conf->expand_progress;
3712 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3713 md_wakeup_thread(mddev->thread);
3714 wait_event(mddev->sb_wait,
3715 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3716 || kthread_should_stop());
3717 spin_lock_irq(&conf->device_lock);
3718 conf->expand_lo = mddev->reshape_position;
3719 spin_unlock_irq(&conf->device_lock);
3720 wake_up(&conf->wait_for_overlap);
3721 }
NeilBrown52c03292006-06-26 00:27:43 -07003722 return conf->chunk_size>>9;
3723}
3724
3725/* FIXME go_faster isn't used */
3726static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3727{
3728 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3729 struct stripe_head *sh;
3730 int pd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003731 int raid_disks = conf->raid_disks;
NeilBrown72626682005-09-09 16:23:54 -07003732 sector_t max_sector = mddev->size << 1;
3733 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07003734 int still_degraded = 0;
3735 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003736
NeilBrown72626682005-09-09 16:23:54 -07003737 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003738 /* just being told to finish up .. nothing much to do */
3739 unplug_slaves(mddev);
NeilBrown29269552006-03-27 01:18:10 -08003740 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3741 end_reshape(conf);
3742 return 0;
3743 }
NeilBrown72626682005-09-09 16:23:54 -07003744
3745 if (mddev->curr_resync < max_sector) /* aborted */
3746 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3747 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003748 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07003749 conf->fullsync = 0;
3750 bitmap_close_sync(mddev->bitmap);
3751
Linus Torvalds1da177e2005-04-16 15:20:36 -07003752 return 0;
3753 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08003754
NeilBrown52c03292006-06-26 00:27:43 -07003755 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3756 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08003757
NeilBrownc6207272008-02-06 01:39:52 -08003758 /* No need to check resync_max as we never do more than one
3759 * stripe, and as resync_max will always be on a chunk boundary,
3760 * if the check in md_do_sync didn't fire, there is no chance
3761 * of overstepping resync_max here
3762 */
3763
NeilBrown16a53ec2006-06-26 00:27:38 -07003764 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07003765 * to resync, then assert that we are finished, because there is
3766 * nothing we can do.
3767 */
NeilBrown3285edf2006-06-26 00:27:55 -07003768 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07003769 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
NeilBrown57afd892005-06-21 17:17:13 -07003770 sector_t rv = (mddev->size << 1) - sector_nr;
3771 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003772 return rv;
3773 }
NeilBrown72626682005-09-09 16:23:54 -07003774 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08003775 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07003776 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3777 /* we can skip this block, and probably more */
3778 sync_blocks /= STRIPE_SECTORS;
3779 *skipped = 1;
3780 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3781 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003782
NeilBrownb47490c2008-02-06 01:39:50 -08003783
3784 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
3785
NeilBrownccfcc3c2006-03-27 01:18:09 -08003786 pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003787 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003788 if (sh == NULL) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003789 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003790 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07003791 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07003792 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08003793 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003794 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003795 /* Need to check if array will still be degraded after recovery/resync
3796 * We don't need to check the 'failed' flag as when that gets set,
3797 * recovery aborts.
3798 */
3799 for (i=0; i<mddev->raid_disks; i++)
3800 if (conf->disks[i].rdev == NULL)
3801 still_degraded = 1;
3802
3803 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
3804
3805 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003806 set_bit(STRIPE_SYNCING, &sh->state);
3807 clear_bit(STRIPE_INSYNC, &sh->state);
3808 spin_unlock(&sh->lock);
3809
NeilBrown16a53ec2006-06-26 00:27:38 -07003810 handle_stripe(sh, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003811 release_stripe(sh);
3812
3813 return STRIPE_SECTORS;
3814}
3815
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003816static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
3817{
3818 /* We may not be able to submit a whole bio at once as there
3819 * may not be enough stripe_heads available.
3820 * We cannot pre-allocate enough stripe_heads as we may need
3821 * more than exist in the cache (if we allow ever large chunks).
3822 * So we do one stripe head at a time and record in
3823 * ->bi_hw_segments how many have been done.
3824 *
3825 * We *know* that this entire raid_bio is in one chunk, so
3826 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3827 */
3828 struct stripe_head *sh;
3829 int dd_idx, pd_idx;
3830 sector_t sector, logical_sector, last_sector;
3831 int scnt = 0;
3832 int remaining;
3833 int handled = 0;
3834
3835 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3836 sector = raid5_compute_sector( logical_sector,
3837 conf->raid_disks,
3838 conf->raid_disks - conf->max_degraded,
3839 &dd_idx,
3840 &pd_idx,
3841 conf);
3842 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
3843
3844 for (; logical_sector < last_sector;
Neil Brown387bb172007-02-08 14:20:29 -08003845 logical_sector += STRIPE_SECTORS,
3846 sector += STRIPE_SECTORS,
3847 scnt++) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003848
3849 if (scnt < raid_bio->bi_hw_segments)
3850 /* already done this stripe */
3851 continue;
3852
3853 sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1);
3854
3855 if (!sh) {
3856 /* failed to get a stripe - must wait */
3857 raid_bio->bi_hw_segments = scnt;
3858 conf->retry_read_aligned = raid_bio;
3859 return handled;
3860 }
3861
3862 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
Neil Brown387bb172007-02-08 14:20:29 -08003863 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
3864 release_stripe(sh);
3865 raid_bio->bi_hw_segments = scnt;
3866 conf->retry_read_aligned = raid_bio;
3867 return handled;
3868 }
3869
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003870 handle_stripe(sh, NULL);
3871 release_stripe(sh);
3872 handled++;
3873 }
3874 spin_lock_irq(&conf->device_lock);
3875 remaining = --raid_bio->bi_phys_segments;
3876 spin_unlock_irq(&conf->device_lock);
3877 if (remaining == 0) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003878
NeilBrown6712ecf2007-09-27 12:47:43 +02003879 raid_bio->bi_end_io(raid_bio,
NeilBrownc2b00852006-12-10 02:20:51 -08003880 test_bit(BIO_UPTODATE, &raid_bio->bi_flags)
3881 ? 0 : -EIO);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003882 }
3883 if (atomic_dec_and_test(&conf->active_aligned_reads))
3884 wake_up(&conf->wait_for_stripe);
3885 return handled;
3886}
3887
3888
3889
Linus Torvalds1da177e2005-04-16 15:20:36 -07003890/*
3891 * This is our raid5 kernel thread.
3892 *
3893 * We scan the hash table for stripes which can be handled now.
3894 * During the scan, completed stripes are saved for us by the interrupt
3895 * handler, so that they will not have to wait for our next wakeup.
3896 */
NeilBrown6ed30032008-02-06 01:40:00 -08003897static void raid5d(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003898{
3899 struct stripe_head *sh;
3900 raid5_conf_t *conf = mddev_to_conf(mddev);
3901 int handled;
3902
Dan Williams45b42332007-07-09 11:56:43 -07003903 pr_debug("+++ raid5d active\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003904
3905 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003906
3907 handled = 0;
3908 spin_lock_irq(&conf->device_lock);
3909 while (1) {
3910 struct list_head *first;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003911 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003912
NeilBrownae3c20c2006-07-10 04:44:17 -07003913 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07003914 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08003915 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07003916 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08003917 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07003918 conf->seq_write = seq;
3919 activate_bit_delay(conf);
3920 }
3921
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003922 while ((bio = remove_bio_from_retry(conf))) {
3923 int ok;
3924 spin_unlock_irq(&conf->device_lock);
3925 ok = retry_aligned_read(conf, bio);
3926 spin_lock_irq(&conf->device_lock);
3927 if (!ok)
3928 break;
3929 handled++;
3930 }
3931
Dan Williamsd84e0f12007-01-02 13:52:30 -07003932 if (list_empty(&conf->handle_list)) {
3933 async_tx_issue_pending_all();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003934 break;
Dan Williamsd84e0f12007-01-02 13:52:30 -07003935 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003936
3937 first = conf->handle_list.next;
3938 sh = list_entry(first, struct stripe_head, lru);
3939
3940 list_del_init(first);
3941 atomic_inc(&sh->count);
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02003942 BUG_ON(atomic_read(&sh->count)!= 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003943 spin_unlock_irq(&conf->device_lock);
3944
3945 handled++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003946 handle_stripe(sh, conf->spare_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003947 release_stripe(sh);
3948
3949 spin_lock_irq(&conf->device_lock);
3950 }
Dan Williams45b42332007-07-09 11:56:43 -07003951 pr_debug("%d stripes handled\n", handled);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003952
3953 spin_unlock_irq(&conf->device_lock);
3954
3955 unplug_slaves(mddev);
3956
Dan Williams45b42332007-07-09 11:56:43 -07003957 pr_debug("--- raid5d inactive\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003958}
3959
NeilBrown3f294f42005-11-08 21:39:25 -08003960static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08003961raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08003962{
NeilBrown007583c2005-11-08 21:39:30 -08003963 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08003964 if (conf)
3965 return sprintf(page, "%d\n", conf->max_nr_stripes);
3966 else
3967 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08003968}
3969
3970static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08003971raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08003972{
NeilBrown007583c2005-11-08 21:39:30 -08003973 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown3f294f42005-11-08 21:39:25 -08003974 char *end;
3975 int new;
3976 if (len >= PAGE_SIZE)
3977 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08003978 if (!conf)
3979 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08003980
3981 new = simple_strtoul(page, &end, 10);
3982 if (!*page || (*end && *end != '\n') )
3983 return -EINVAL;
3984 if (new <= 16 || new > 32768)
3985 return -EINVAL;
3986 while (new < conf->max_nr_stripes) {
3987 if (drop_one_stripe(conf))
3988 conf->max_nr_stripes--;
3989 else
3990 break;
3991 }
NeilBrown2a2275d2007-01-26 00:57:11 -08003992 md_allow_write(mddev);
NeilBrown3f294f42005-11-08 21:39:25 -08003993 while (new > conf->max_nr_stripes) {
3994 if (grow_one_stripe(conf))
3995 conf->max_nr_stripes++;
3996 else break;
3997 }
3998 return len;
3999}
NeilBrown007583c2005-11-08 21:39:30 -08004000
NeilBrown96de1e62005-11-08 21:39:39 -08004001static struct md_sysfs_entry
4002raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4003 raid5_show_stripe_cache_size,
4004 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08004005
4006static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08004007stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004008{
NeilBrown007583c2005-11-08 21:39:30 -08004009 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08004010 if (conf)
4011 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4012 else
4013 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004014}
4015
NeilBrown96de1e62005-11-08 21:39:39 -08004016static struct md_sysfs_entry
4017raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08004018
NeilBrown007583c2005-11-08 21:39:30 -08004019static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08004020 &raid5_stripecache_size.attr,
4021 &raid5_stripecache_active.attr,
4022 NULL,
4023};
NeilBrown007583c2005-11-08 21:39:30 -08004024static struct attribute_group raid5_attrs_group = {
4025 .name = NULL,
4026 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08004027};
4028
NeilBrown72626682005-09-09 16:23:54 -07004029static int run(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004030{
4031 raid5_conf_t *conf;
4032 int raid_disk, memory;
4033 mdk_rdev_t *rdev;
4034 struct disk_info *disk;
4035 struct list_head *tmp;
NeilBrown02c2de82006-10-03 01:15:47 -07004036 int working_disks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004037
NeilBrown16a53ec2006-06-26 00:27:38 -07004038 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
4039 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
NeilBrown14f8d262006-01-06 00:20:14 -08004040 mdname(mddev), mddev->level);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004041 return -EIO;
4042 }
4043
NeilBrownf6705572006-03-27 01:18:11 -08004044 if (mddev->reshape_position != MaxSector) {
4045 /* Check that we can continue the reshape.
4046 * Currently only disks can change, it must
4047 * increase, and we must be past the point where
4048 * a stripe over-writes itself
4049 */
4050 sector_t here_new, here_old;
4051 int old_disks;
NeilBrownf4168852007-02-28 20:11:53 -08004052 int max_degraded = (mddev->level == 5 ? 1 : 2);
NeilBrownf6705572006-03-27 01:18:11 -08004053
4054 if (mddev->new_level != mddev->level ||
4055 mddev->new_layout != mddev->layout ||
4056 mddev->new_chunk != mddev->chunk_size) {
NeilBrownf4168852007-02-28 20:11:53 -08004057 printk(KERN_ERR "raid5: %s: unsupported reshape "
4058 "required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004059 mdname(mddev));
4060 return -EINVAL;
4061 }
4062 if (mddev->delta_disks <= 0) {
NeilBrownf4168852007-02-28 20:11:53 -08004063 printk(KERN_ERR "raid5: %s: unsupported reshape "
4064 "(reduce disks) required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004065 mdname(mddev));
4066 return -EINVAL;
4067 }
4068 old_disks = mddev->raid_disks - mddev->delta_disks;
4069 /* reshape_position must be on a new-stripe boundary, and one
NeilBrownf4168852007-02-28 20:11:53 -08004070 * further up in new geometry must map after here in old
4071 * geometry.
NeilBrownf6705572006-03-27 01:18:11 -08004072 */
4073 here_new = mddev->reshape_position;
NeilBrownf4168852007-02-28 20:11:53 -08004074 if (sector_div(here_new, (mddev->chunk_size>>9)*
4075 (mddev->raid_disks - max_degraded))) {
4076 printk(KERN_ERR "raid5: reshape_position not "
4077 "on a stripe boundary\n");
NeilBrownf6705572006-03-27 01:18:11 -08004078 return -EINVAL;
4079 }
4080 /* here_new is the stripe we will write to */
4081 here_old = mddev->reshape_position;
NeilBrownf4168852007-02-28 20:11:53 -08004082 sector_div(here_old, (mddev->chunk_size>>9)*
4083 (old_disks-max_degraded));
4084 /* here_old is the first stripe that we might need to read
4085 * from */
NeilBrownf6705572006-03-27 01:18:11 -08004086 if (here_new >= here_old) {
4087 /* Reading from the same stripe as writing to - bad */
NeilBrownf4168852007-02-28 20:11:53 -08004088 printk(KERN_ERR "raid5: reshape_position too early for "
4089 "auto-recovery - aborting.\n");
NeilBrownf6705572006-03-27 01:18:11 -08004090 return -EINVAL;
4091 }
4092 printk(KERN_INFO "raid5: reshape will continue\n");
4093 /* OK, we should be able to continue; */
4094 }
4095
4096
NeilBrownb55e6bf2006-03-27 01:18:06 -08004097 mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004098 if ((conf = mddev->private) == NULL)
4099 goto abort;
NeilBrownf6705572006-03-27 01:18:11 -08004100 if (mddev->reshape_position == MaxSector) {
4101 conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
4102 } else {
4103 conf->raid_disks = mddev->raid_disks;
4104 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4105 }
4106
4107 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
NeilBrownb55e6bf2006-03-27 01:18:06 -08004108 GFP_KERNEL);
4109 if (!conf->disks)
4110 goto abort;
NeilBrown9ffae0c2006-01-06 00:20:32 -08004111
Linus Torvalds1da177e2005-04-16 15:20:36 -07004112 conf->mddev = mddev;
4113
NeilBrownfccddba2006-01-06 00:20:33 -08004114 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004115 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004116
NeilBrown16a53ec2006-06-26 00:27:38 -07004117 if (mddev->level == 6) {
4118 conf->spare_page = alloc_page(GFP_KERNEL);
4119 if (!conf->spare_page)
4120 goto abort;
4121 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004122 spin_lock_init(&conf->device_lock);
4123 init_waitqueue_head(&conf->wait_for_stripe);
4124 init_waitqueue_head(&conf->wait_for_overlap);
4125 INIT_LIST_HEAD(&conf->handle_list);
4126 INIT_LIST_HEAD(&conf->delayed_list);
NeilBrown72626682005-09-09 16:23:54 -07004127 INIT_LIST_HEAD(&conf->bitmap_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004128 INIT_LIST_HEAD(&conf->inactive_list);
4129 atomic_set(&conf->active_stripes, 0);
4130 atomic_set(&conf->preread_active_stripes, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004131 atomic_set(&conf->active_aligned_reads, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004132
Dan Williams45b42332007-07-09 11:56:43 -07004133 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004134
NeilBrownd089c6a2008-02-06 01:39:59 -08004135 rdev_for_each(rdev, tmp, mddev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004136 raid_disk = rdev->raid_disk;
NeilBrownf6705572006-03-27 01:18:11 -08004137 if (raid_disk >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07004138 || raid_disk < 0)
4139 continue;
4140 disk = conf->disks + raid_disk;
4141
4142 disk->rdev = rdev;
4143
NeilBrownb2d444d2005-11-08 21:39:31 -08004144 if (test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004145 char b[BDEVNAME_SIZE];
4146 printk(KERN_INFO "raid5: device %s operational as raid"
4147 " disk %d\n", bdevname(rdev->bdev,b),
4148 raid_disk);
NeilBrown02c2de82006-10-03 01:15:47 -07004149 working_disks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004150 }
4151 }
4152
Linus Torvalds1da177e2005-04-16 15:20:36 -07004153 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004154 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004155 */
NeilBrown02c2de82006-10-03 01:15:47 -07004156 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004157 conf->mddev = mddev;
4158 conf->chunk_size = mddev->chunk_size;
4159 conf->level = mddev->level;
NeilBrown16a53ec2006-06-26 00:27:38 -07004160 if (conf->level == 6)
4161 conf->max_degraded = 2;
4162 else
4163 conf->max_degraded = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004164 conf->algorithm = mddev->layout;
4165 conf->max_nr_stripes = NR_STRIPES;
NeilBrownf6705572006-03-27 01:18:11 -08004166 conf->expand_progress = mddev->reshape_position;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004167
4168 /* device size must be a multiple of chunk size */
4169 mddev->size &= ~(mddev->chunk_size/1024 -1);
NeilBrownb1581562005-07-31 22:34:50 -07004170 mddev->resync_max_sectors = mddev->size << 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004171
NeilBrown16a53ec2006-06-26 00:27:38 -07004172 if (conf->level == 6 && conf->raid_disks < 4) {
4173 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4174 mdname(mddev), conf->raid_disks);
4175 goto abort;
4176 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004177 if (!conf->chunk_size || conf->chunk_size % 4) {
4178 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
4179 conf->chunk_size, mdname(mddev));
4180 goto abort;
4181 }
4182 if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
4183 printk(KERN_ERR
4184 "raid5: unsupported parity algorithm %d for %s\n",
4185 conf->algorithm, mdname(mddev));
4186 goto abort;
4187 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004188 if (mddev->degraded > conf->max_degraded) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004189 printk(KERN_ERR "raid5: not enough operational devices for %s"
4190 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07004191 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004192 goto abort;
4193 }
4194
NeilBrown16a53ec2006-06-26 00:27:38 -07004195 if (mddev->degraded > 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07004196 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08004197 if (mddev->ok_start_degraded)
4198 printk(KERN_WARNING
4199 "raid5: starting dirty degraded array: %s"
4200 "- data corruption possible.\n",
4201 mdname(mddev));
4202 else {
4203 printk(KERN_ERR
4204 "raid5: cannot start dirty degraded array for %s\n",
4205 mdname(mddev));
4206 goto abort;
4207 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004208 }
4209
4210 {
4211 mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4212 if (!mddev->thread) {
4213 printk(KERN_ERR
4214 "raid5: couldn't allocate thread for %s\n",
4215 mdname(mddev));
4216 goto abort;
4217 }
4218 }
NeilBrown50368052005-12-12 02:39:17 -08004219 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07004220 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4221 if (grow_stripes(conf, conf->max_nr_stripes)) {
4222 printk(KERN_ERR
4223 "raid5: couldn't allocate %dkB for buffers\n", memory);
4224 shrink_stripes(conf);
4225 md_unregister_thread(mddev->thread);
4226 goto abort;
4227 } else
4228 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4229 memory, mdname(mddev));
4230
4231 if (mddev->degraded == 0)
4232 printk("raid5: raid level %d set %s active with %d out of %d"
4233 " devices, algorithm %d\n", conf->level, mdname(mddev),
4234 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4235 conf->algorithm);
4236 else
4237 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4238 " out of %d devices, algorithm %d\n", conf->level,
4239 mdname(mddev), mddev->raid_disks - mddev->degraded,
4240 mddev->raid_disks, conf->algorithm);
4241
4242 print_raid5_conf(conf);
4243
NeilBrownf6705572006-03-27 01:18:11 -08004244 if (conf->expand_progress != MaxSector) {
4245 printk("...ok start reshape thread\n");
NeilBrownb578d552006-03-27 01:18:12 -08004246 conf->expand_lo = conf->expand_progress;
NeilBrownf6705572006-03-27 01:18:11 -08004247 atomic_set(&conf->reshape_stripes, 0);
4248 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4249 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4250 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4251 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4252 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4253 "%s_reshape");
NeilBrownf6705572006-03-27 01:18:11 -08004254 }
4255
Linus Torvalds1da177e2005-04-16 15:20:36 -07004256 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07004257 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07004258 */
4259 {
NeilBrown16a53ec2006-06-26 00:27:38 -07004260 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4261 int stripe = data_disks *
NeilBrown8932c2e2006-06-26 00:27:36 -07004262 (mddev->chunk_size / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004263 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4264 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4265 }
4266
4267 /* Ok, everything is just fine now */
NeilBrown5e55e2f2007-03-26 21:32:14 -08004268 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4269 printk(KERN_WARNING
4270 "raid5: failed to create sysfs attributes for %s\n",
4271 mdname(mddev));
NeilBrown7a5febe2005-05-16 21:53:16 -07004272
4273 mddev->queue->unplug_fn = raid5_unplug_device;
NeilBrownf022b2f2006-10-03 01:15:56 -07004274 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown041ae522007-03-26 21:32:14 -08004275 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
NeilBrownf022b2f2006-10-03 01:15:56 -07004276
NeilBrown16a53ec2006-06-26 00:27:38 -07004277 mddev->array_size = mddev->size * (conf->previous_raid_disks -
4278 conf->max_degraded);
NeilBrown7a5febe2005-05-16 21:53:16 -07004279
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08004280 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
4281
Linus Torvalds1da177e2005-04-16 15:20:36 -07004282 return 0;
4283abort:
4284 if (conf) {
4285 print_raid5_conf(conf);
NeilBrown16a53ec2006-06-26 00:27:38 -07004286 safe_put_page(conf->spare_page);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004287 kfree(conf->disks);
NeilBrownfccddba2006-01-06 00:20:33 -08004288 kfree(conf->stripe_hashtbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004289 kfree(conf);
4290 }
4291 mddev->private = NULL;
4292 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4293 return -EIO;
4294}
4295
4296
4297
NeilBrown3f294f42005-11-08 21:39:25 -08004298static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004299{
4300 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4301
4302 md_unregister_thread(mddev->thread);
4303 mddev->thread = NULL;
4304 shrink_stripes(conf);
NeilBrownfccddba2006-01-06 00:20:33 -08004305 kfree(conf->stripe_hashtbl);
NeilBrown041ae522007-03-26 21:32:14 -08004306 mddev->queue->backing_dev_info.congested_fn = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004307 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
NeilBrown007583c2005-11-08 21:39:30 -08004308 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004309 kfree(conf->disks);
NeilBrown96de1e62005-11-08 21:39:39 -08004310 kfree(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004311 mddev->private = NULL;
4312 return 0;
4313}
4314
Dan Williams45b42332007-07-09 11:56:43 -07004315#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004316static void print_sh (struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004317{
4318 int i;
4319
NeilBrown16a53ec2006-06-26 00:27:38 -07004320 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4321 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4322 seq_printf(seq, "sh %llu, count %d.\n",
4323 (unsigned long long)sh->sector, atomic_read(&sh->count));
4324 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08004325 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004326 seq_printf(seq, "(cache%d: %p %ld) ",
4327 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004328 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004329 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004330}
4331
NeilBrown16a53ec2006-06-26 00:27:38 -07004332static void printall (struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004333{
4334 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08004335 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004336 int i;
4337
4338 spin_lock_irq(&conf->device_lock);
4339 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08004340 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004341 if (sh->raid_conf != conf)
4342 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07004343 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004344 }
4345 }
4346 spin_unlock_irq(&conf->device_lock);
4347}
4348#endif
4349
4350static void status (struct seq_file *seq, mddev_t *mddev)
4351{
4352 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4353 int i;
4354
4355 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07004356 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004357 for (i = 0; i < conf->raid_disks; i++)
4358 seq_printf (seq, "%s",
4359 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08004360 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004361 seq_printf (seq, "]");
Dan Williams45b42332007-07-09 11:56:43 -07004362#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004363 seq_printf (seq, "\n");
4364 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004365#endif
4366}
4367
4368static void print_raid5_conf (raid5_conf_t *conf)
4369{
4370 int i;
4371 struct disk_info *tmp;
4372
4373 printk("RAID5 conf printout:\n");
4374 if (!conf) {
4375 printk("(conf==NULL)\n");
4376 return;
4377 }
NeilBrown02c2de82006-10-03 01:15:47 -07004378 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4379 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004380
4381 for (i = 0; i < conf->raid_disks; i++) {
4382 char b[BDEVNAME_SIZE];
4383 tmp = conf->disks + i;
4384 if (tmp->rdev)
4385 printk(" disk %d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08004386 i, !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07004387 bdevname(tmp->rdev->bdev,b));
4388 }
4389}
4390
4391static int raid5_spare_active(mddev_t *mddev)
4392{
4393 int i;
4394 raid5_conf_t *conf = mddev->private;
4395 struct disk_info *tmp;
4396
4397 for (i = 0; i < conf->raid_disks; i++) {
4398 tmp = conf->disks + i;
4399 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08004400 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07004401 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4402 unsigned long flags;
4403 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004404 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07004405 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004406 }
4407 }
4408 print_raid5_conf(conf);
4409 return 0;
4410}
4411
4412static int raid5_remove_disk(mddev_t *mddev, int number)
4413{
4414 raid5_conf_t *conf = mddev->private;
4415 int err = 0;
4416 mdk_rdev_t *rdev;
4417 struct disk_info *p = conf->disks + number;
4418
4419 print_raid5_conf(conf);
4420 rdev = p->rdev;
4421 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004422 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07004423 atomic_read(&rdev->nr_pending)) {
4424 err = -EBUSY;
4425 goto abort;
4426 }
4427 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07004428 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004429 if (atomic_read(&rdev->nr_pending)) {
4430 /* lost the race, try later */
4431 err = -EBUSY;
4432 p->rdev = rdev;
4433 }
4434 }
4435abort:
4436
4437 print_raid5_conf(conf);
4438 return err;
4439}
4440
4441static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4442{
4443 raid5_conf_t *conf = mddev->private;
4444 int found = 0;
4445 int disk;
4446 struct disk_info *p;
4447
NeilBrown16a53ec2006-06-26 00:27:38 -07004448 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004449 /* no point adding a device */
4450 return 0;
4451
4452 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004453 * find the disk ... but prefer rdev->saved_raid_disk
4454 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004455 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004456 if (rdev->saved_raid_disk >= 0 &&
4457 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4458 disk = rdev->saved_raid_disk;
4459 else
4460 disk = 0;
4461 for ( ; disk < conf->raid_disks; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004462 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004463 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004464 rdev->raid_disk = disk;
4465 found = 1;
NeilBrown72626682005-09-09 16:23:54 -07004466 if (rdev->saved_raid_disk != disk)
4467 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08004468 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004469 break;
4470 }
4471 print_raid5_conf(conf);
4472 return found;
4473}
4474
4475static int raid5_resize(mddev_t *mddev, sector_t sectors)
4476{
4477 /* no resync is happening, and there is enough space
4478 * on all devices, so we can resize.
4479 * We need to make sure resync covers any new space.
4480 * If the array is shrinking we should possibly wait until
4481 * any io in the removed space completes, but it hardly seems
4482 * worth it.
4483 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004484 raid5_conf_t *conf = mddev_to_conf(mddev);
4485
Linus Torvalds1da177e2005-04-16 15:20:36 -07004486 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07004487 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004488 set_capacity(mddev->gendisk, mddev->array_size << 1);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004489 mddev->changed = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004490 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
4491 mddev->recovery_cp = mddev->size << 1;
4492 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4493 }
4494 mddev->size = sectors /2;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07004495 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004496 return 0;
4497}
4498
NeilBrown29269552006-03-27 01:18:10 -08004499#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08004500static int raid5_check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08004501{
4502 raid5_conf_t *conf = mddev_to_conf(mddev);
4503 int err;
NeilBrown29269552006-03-27 01:18:10 -08004504
NeilBrown63c70c42006-03-27 01:18:13 -08004505 if (mddev->delta_disks < 0 ||
4506 mddev->new_level != mddev->level)
4507 return -EINVAL; /* Cannot shrink array or change level yet */
4508 if (mddev->delta_disks == 0)
NeilBrown29269552006-03-27 01:18:10 -08004509 return 0; /* nothing to do */
4510
4511 /* Can only proceed if there are plenty of stripe_heads.
4512 * We need a minimum of one full stripe,, and for sensible progress
4513 * it is best to have about 4 times that.
4514 * If we require 4 times, then the default 256 4K stripe_heads will
4515 * allow for chunk sizes up to 256K, which is probably OK.
4516 * If the chunk size is greater, user-space should request more
4517 * stripe_heads first.
4518 */
NeilBrown63c70c42006-03-27 01:18:13 -08004519 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
4520 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
NeilBrown29269552006-03-27 01:18:10 -08004521 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
4522 (mddev->chunk_size / STRIPE_SIZE)*4);
4523 return -ENOSPC;
4524 }
4525
NeilBrown63c70c42006-03-27 01:18:13 -08004526 err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
4527 if (err)
4528 return err;
4529
NeilBrownb4c4c7b2007-02-28 20:11:48 -08004530 if (mddev->degraded > conf->max_degraded)
4531 return -EINVAL;
NeilBrown63c70c42006-03-27 01:18:13 -08004532 /* looks like we might be able to manage this */
4533 return 0;
4534}
4535
4536static int raid5_start_reshape(mddev_t *mddev)
4537{
4538 raid5_conf_t *conf = mddev_to_conf(mddev);
4539 mdk_rdev_t *rdev;
4540 struct list_head *rtmp;
4541 int spares = 0;
4542 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07004543 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08004544
NeilBrownf4168852007-02-28 20:11:53 -08004545 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
NeilBrown63c70c42006-03-27 01:18:13 -08004546 return -EBUSY;
4547
NeilBrownd089c6a2008-02-06 01:39:59 -08004548 rdev_for_each(rdev, rtmp, mddev)
NeilBrown29269552006-03-27 01:18:10 -08004549 if (rdev->raid_disk < 0 &&
4550 !test_bit(Faulty, &rdev->flags))
4551 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08004552
NeilBrownf4168852007-02-28 20:11:53 -08004553 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
NeilBrown29269552006-03-27 01:18:10 -08004554 /* Not enough devices even to make a degraded array
4555 * of that size
4556 */
4557 return -EINVAL;
4558
NeilBrownf6705572006-03-27 01:18:11 -08004559 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08004560 spin_lock_irq(&conf->device_lock);
4561 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08004562 conf->raid_disks += mddev->delta_disks;
NeilBrown29269552006-03-27 01:18:10 -08004563 conf->expand_progress = 0;
NeilBrownb578d552006-03-27 01:18:12 -08004564 conf->expand_lo = 0;
NeilBrown29269552006-03-27 01:18:10 -08004565 spin_unlock_irq(&conf->device_lock);
4566
4567 /* Add some new drives, as many as will fit.
4568 * We know there are enough to make the newly sized array work.
4569 */
NeilBrownd089c6a2008-02-06 01:39:59 -08004570 rdev_for_each(rdev, rtmp, mddev)
NeilBrown29269552006-03-27 01:18:10 -08004571 if (rdev->raid_disk < 0 &&
4572 !test_bit(Faulty, &rdev->flags)) {
4573 if (raid5_add_disk(mddev, rdev)) {
4574 char nm[20];
4575 set_bit(In_sync, &rdev->flags);
NeilBrown29269552006-03-27 01:18:10 -08004576 added_devices++;
NeilBrown5fd6c1d2006-06-26 00:27:40 -07004577 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08004578 sprintf(nm, "rd%d", rdev->raid_disk);
NeilBrown5e55e2f2007-03-26 21:32:14 -08004579 if (sysfs_create_link(&mddev->kobj,
4580 &rdev->kobj, nm))
4581 printk(KERN_WARNING
4582 "raid5: failed to create "
4583 " link %s for %s\n",
4584 nm, mdname(mddev));
NeilBrown29269552006-03-27 01:18:10 -08004585 } else
4586 break;
4587 }
4588
NeilBrownc04be0a2006-10-03 01:15:53 -07004589 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08004590 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
NeilBrownc04be0a2006-10-03 01:15:53 -07004591 spin_unlock_irqrestore(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08004592 mddev->raid_disks = conf->raid_disks;
NeilBrownf6705572006-03-27 01:18:11 -08004593 mddev->reshape_position = 0;
NeilBrown850b2b42006-10-03 01:15:46 -07004594 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08004595
NeilBrown29269552006-03-27 01:18:10 -08004596 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4597 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4598 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4599 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4600 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4601 "%s_reshape");
4602 if (!mddev->sync_thread) {
4603 mddev->recovery = 0;
4604 spin_lock_irq(&conf->device_lock);
4605 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
4606 conf->expand_progress = MaxSector;
4607 spin_unlock_irq(&conf->device_lock);
4608 return -EAGAIN;
4609 }
4610 md_wakeup_thread(mddev->sync_thread);
4611 md_new_event(mddev);
4612 return 0;
4613}
4614#endif
4615
4616static void end_reshape(raid5_conf_t *conf)
4617{
4618 struct block_device *bdev;
4619
NeilBrownf6705572006-03-27 01:18:11 -08004620 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
NeilBrownf4168852007-02-28 20:11:53 -08004621 conf->mddev->array_size = conf->mddev->size *
4622 (conf->raid_disks - conf->max_degraded);
NeilBrownf6705572006-03-27 01:18:11 -08004623 set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004624 conf->mddev->changed = 1;
NeilBrown29269552006-03-27 01:18:10 -08004625
NeilBrownf6705572006-03-27 01:18:11 -08004626 bdev = bdget_disk(conf->mddev->gendisk, 0);
4627 if (bdev) {
4628 mutex_lock(&bdev->bd_inode->i_mutex);
NeilBrown0692c6b2006-11-08 17:44:48 -08004629 i_size_write(bdev->bd_inode, (loff_t)conf->mddev->array_size << 10);
NeilBrownf6705572006-03-27 01:18:11 -08004630 mutex_unlock(&bdev->bd_inode->i_mutex);
4631 bdput(bdev);
4632 }
4633 spin_lock_irq(&conf->device_lock);
4634 conf->expand_progress = MaxSector;
4635 spin_unlock_irq(&conf->device_lock);
4636 conf->mddev->reshape_position = MaxSector;
NeilBrown16a53ec2006-06-26 00:27:38 -07004637
4638 /* read-ahead size must cover two whole stripes, which is
4639 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4640 */
4641 {
4642 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4643 int stripe = data_disks *
4644 (conf->mddev->chunk_size / PAGE_SIZE);
4645 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4646 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4647 }
NeilBrown29269552006-03-27 01:18:10 -08004648 }
NeilBrown29269552006-03-27 01:18:10 -08004649}
4650
NeilBrown72626682005-09-09 16:23:54 -07004651static void raid5_quiesce(mddev_t *mddev, int state)
4652{
4653 raid5_conf_t *conf = mddev_to_conf(mddev);
4654
4655 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08004656 case 2: /* resume for a suspend */
4657 wake_up(&conf->wait_for_overlap);
4658 break;
4659
NeilBrown72626682005-09-09 16:23:54 -07004660 case 1: /* stop all writes */
4661 spin_lock_irq(&conf->device_lock);
4662 conf->quiesce = 1;
4663 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004664 atomic_read(&conf->active_stripes) == 0 &&
4665 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07004666 conf->device_lock, /* nothing */);
4667 spin_unlock_irq(&conf->device_lock);
4668 break;
4669
4670 case 0: /* re-enable writes */
4671 spin_lock_irq(&conf->device_lock);
4672 conf->quiesce = 0;
4673 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08004674 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07004675 spin_unlock_irq(&conf->device_lock);
4676 break;
4677 }
NeilBrown72626682005-09-09 16:23:54 -07004678}
NeilBrownb15c2e52006-01-06 00:20:16 -08004679
NeilBrown16a53ec2006-06-26 00:27:38 -07004680static struct mdk_personality raid6_personality =
4681{
4682 .name = "raid6",
4683 .level = 6,
4684 .owner = THIS_MODULE,
4685 .make_request = make_request,
4686 .run = run,
4687 .stop = stop,
4688 .status = status,
4689 .error_handler = error,
4690 .hot_add_disk = raid5_add_disk,
4691 .hot_remove_disk= raid5_remove_disk,
4692 .spare_active = raid5_spare_active,
4693 .sync_request = sync_request,
4694 .resize = raid5_resize,
NeilBrownf4168852007-02-28 20:11:53 -08004695#ifdef CONFIG_MD_RAID5_RESHAPE
4696 .check_reshape = raid5_check_reshape,
4697 .start_reshape = raid5_start_reshape,
4698#endif
NeilBrown16a53ec2006-06-26 00:27:38 -07004699 .quiesce = raid5_quiesce,
4700};
NeilBrown2604b702006-01-06 00:20:36 -08004701static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07004702{
4703 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08004704 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004705 .owner = THIS_MODULE,
4706 .make_request = make_request,
4707 .run = run,
4708 .stop = stop,
4709 .status = status,
4710 .error_handler = error,
4711 .hot_add_disk = raid5_add_disk,
4712 .hot_remove_disk= raid5_remove_disk,
4713 .spare_active = raid5_spare_active,
4714 .sync_request = sync_request,
4715 .resize = raid5_resize,
NeilBrown29269552006-03-27 01:18:10 -08004716#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08004717 .check_reshape = raid5_check_reshape,
4718 .start_reshape = raid5_start_reshape,
NeilBrown29269552006-03-27 01:18:10 -08004719#endif
NeilBrown72626682005-09-09 16:23:54 -07004720 .quiesce = raid5_quiesce,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004721};
4722
NeilBrown2604b702006-01-06 00:20:36 -08004723static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07004724{
NeilBrown2604b702006-01-06 00:20:36 -08004725 .name = "raid4",
4726 .level = 4,
4727 .owner = THIS_MODULE,
4728 .make_request = make_request,
4729 .run = run,
4730 .stop = stop,
4731 .status = status,
4732 .error_handler = error,
4733 .hot_add_disk = raid5_add_disk,
4734 .hot_remove_disk= raid5_remove_disk,
4735 .spare_active = raid5_spare_active,
4736 .sync_request = sync_request,
4737 .resize = raid5_resize,
NeilBrown3d378902007-03-26 21:32:13 -08004738#ifdef CONFIG_MD_RAID5_RESHAPE
4739 .check_reshape = raid5_check_reshape,
4740 .start_reshape = raid5_start_reshape,
4741#endif
NeilBrown2604b702006-01-06 00:20:36 -08004742 .quiesce = raid5_quiesce,
4743};
4744
4745static int __init raid5_init(void)
4746{
NeilBrown16a53ec2006-06-26 00:27:38 -07004747 int e;
4748
4749 e = raid6_select_algo();
4750 if ( e )
4751 return e;
4752 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08004753 register_md_personality(&raid5_personality);
4754 register_md_personality(&raid4_personality);
4755 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004756}
4757
NeilBrown2604b702006-01-06 00:20:36 -08004758static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004759{
NeilBrown16a53ec2006-06-26 00:27:38 -07004760 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08004761 unregister_md_personality(&raid5_personality);
4762 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004763}
4764
4765module_init(raid5_init);
4766module_exit(raid5_exit);
4767MODULE_LICENSE("GPL");
4768MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08004769MODULE_ALIAS("md-raid5");
4770MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08004771MODULE_ALIAS("md-level-5");
4772MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07004773MODULE_ALIAS("md-personality-8"); /* RAID6 */
4774MODULE_ALIAS("md-raid6");
4775MODULE_ALIAS("md-level-6");
4776
4777/* This used to be two separate modules, they were: */
4778MODULE_ALIAS("raid5");
4779MODULE_ALIAS("raid6");