blob: 4616bc3a6e713065e689943db4cdde421076d318 [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
NeilBrownbff61972009-03-31 14:33:13 +110046#include <linux/blkdev.h>
NeilBrownf6705572006-03-27 01:18:11 -080047#include <linux/kthread.h>
Dan Williamsf701d582009-03-31 15:09:39 +110048#include <linux/raid/pq.h>
Dan Williams91c00922007-01-02 13:52:30 -070049#include <linux/async_tx.h>
NeilBrownbff61972009-03-31 14:33:13 +110050#include <linux/seq_file.h>
NeilBrown43b2e5d2009-03-31 14:33:13 +110051#include "md.h"
NeilBrownbff61972009-03-31 14:33:13 +110052#include "raid5.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110053#include "bitmap.h"
NeilBrown72626682005-09-09 16:23:54 -070054
Linus Torvalds1da177e2005-04-16 15:20:36 -070055/*
56 * Stripe cache
57 */
58
59#define NR_STRIPES 256
60#define STRIPE_SIZE PAGE_SIZE
61#define STRIPE_SHIFT (PAGE_SHIFT - 9)
62#define STRIPE_SECTORS (STRIPE_SIZE>>9)
63#define IO_THRESHOLD 1
Dan Williams8b3e6cd2008-04-28 02:15:53 -070064#define BYPASS_THRESHOLD 1
NeilBrownfccddba2006-01-06 00:20:33 -080065#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#define HASH_MASK (NR_HASH - 1)
67
NeilBrownfccddba2006-01-06 00:20:33 -080068#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70/* bio's attached to a stripe+device for I/O are linked together in bi_sector
71 * order without overlap. There may be several bio's per stripe+device, and
72 * a bio could span several devices.
73 * When walking this list for a particular stripe+device, we must never proceed
74 * beyond a bio that extends past this device, as the next bio might no longer
75 * be valid.
76 * This macro is used to determine the 'next' bio in the list, given the sector
77 * of the current stripe+device
78 */
79#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
80/*
81 * The following can be used to debug the driver
82 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070083#define RAID5_PARANOIA 1
84#if RAID5_PARANOIA && defined(CONFIG_SMP)
85# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
86#else
87# define CHECK_DEVLOCK()
88#endif
89
Dan Williams45b42332007-07-09 11:56:43 -070090#ifdef DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#define inline
92#define __inline__
93#endif
94
Bernd Schubert6be9d492008-05-23 13:04:34 -070095#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
96
Jens Axboe960e7392008-08-15 10:41:18 +020097/*
Jens Axboe5b99c2f2008-08-15 10:56:11 +020098 * We maintain a biased count of active stripes in the bottom 16 bits of
99 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
Jens Axboe960e7392008-08-15 10:41:18 +0200100 */
101static inline int raid5_bi_phys_segments(struct bio *bio)
102{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200103 return bio->bi_phys_segments & 0xffff;
Jens Axboe960e7392008-08-15 10:41:18 +0200104}
105
106static inline int raid5_bi_hw_segments(struct bio *bio)
107{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200108 return (bio->bi_phys_segments >> 16) & 0xffff;
Jens Axboe960e7392008-08-15 10:41:18 +0200109}
110
111static inline int raid5_dec_bi_phys_segments(struct bio *bio)
112{
113 --bio->bi_phys_segments;
114 return raid5_bi_phys_segments(bio);
115}
116
117static inline int raid5_dec_bi_hw_segments(struct bio *bio)
118{
119 unsigned short val = raid5_bi_hw_segments(bio);
120
121 --val;
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200122 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
Jens Axboe960e7392008-08-15 10:41:18 +0200123 return val;
124}
125
126static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
127{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200128 bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
Jens Axboe960e7392008-08-15 10:41:18 +0200129}
130
NeilBrownd0dabf72009-03-31 14:39:38 +1100131/* Find first data disk in a raid6 stripe */
132static inline int raid6_d0(struct stripe_head *sh)
133{
NeilBrown67cc2b82009-03-31 14:39:38 +1100134 if (sh->ddf_layout)
135 /* ddf always start from first device */
136 return 0;
137 /* md starts just after Q block */
NeilBrownd0dabf72009-03-31 14:39:38 +1100138 if (sh->qd_idx == sh->disks - 1)
139 return 0;
140 else
141 return sh->qd_idx + 1;
142}
NeilBrown16a53ec2006-06-26 00:27:38 -0700143static inline int raid6_next_disk(int disk, int raid_disks)
144{
145 disk++;
146 return (disk < raid_disks) ? disk : 0;
147}
Dan Williamsa4456852007-07-09 11:56:43 -0700148
NeilBrownd0dabf72009-03-31 14:39:38 +1100149/* When walking through the disks in a raid5, starting at raid6_d0,
150 * We need to map each disk to a 'slot', where the data disks are slot
151 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
152 * is raid_disks-1. This help does that mapping.
153 */
NeilBrown67cc2b82009-03-31 14:39:38 +1100154static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
155 int *count, int syndrome_disks)
NeilBrownd0dabf72009-03-31 14:39:38 +1100156{
157 int slot;
NeilBrown67cc2b82009-03-31 14:39:38 +1100158
NeilBrownd0dabf72009-03-31 14:39:38 +1100159 if (idx == sh->pd_idx)
NeilBrown67cc2b82009-03-31 14:39:38 +1100160 return syndrome_disks;
NeilBrownd0dabf72009-03-31 14:39:38 +1100161 if (idx == sh->qd_idx)
NeilBrown67cc2b82009-03-31 14:39:38 +1100162 return syndrome_disks + 1;
NeilBrownd0dabf72009-03-31 14:39:38 +1100163 slot = (*count)++;
164 return slot;
165}
166
Dan Williamsa4456852007-07-09 11:56:43 -0700167static void return_io(struct bio *return_bi)
168{
169 struct bio *bi = return_bi;
170 while (bi) {
Dan Williamsa4456852007-07-09 11:56:43 -0700171
172 return_bi = bi->bi_next;
173 bi->bi_next = NULL;
174 bi->bi_size = 0;
Neil Brown0e13fe232008-06-28 08:31:20 +1000175 bio_endio(bi, 0);
Dan Williamsa4456852007-07-09 11:56:43 -0700176 bi = return_bi;
177 }
178}
179
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180static void print_raid5_conf (raid5_conf_t *conf);
181
Dan Williams600aa102008-06-28 08:32:05 +1000182static int stripe_operations_active(struct stripe_head *sh)
183{
184 return sh->check_state || sh->reconstruct_state ||
185 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
186 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
187}
188
Arjan van de Ven858119e2006-01-14 13:20:43 -0800189static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190{
191 if (atomic_dec_and_test(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200192 BUG_ON(!list_empty(&sh->lru));
193 BUG_ON(atomic_read(&conf->active_stripes)==0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 if (test_bit(STRIPE_HANDLE, &sh->state)) {
NeilBrown7c785b72006-07-10 04:44:16 -0700195 if (test_bit(STRIPE_DELAYED, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 list_add_tail(&sh->lru, &conf->delayed_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700197 blk_plug_device(conf->mddev->queue);
198 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
NeilBrownae3c20c2006-07-10 04:44:17 -0700199 sh->bm_seq - conf->seq_write > 0) {
NeilBrown72626682005-09-09 16:23:54 -0700200 list_add_tail(&sh->lru, &conf->bitmap_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700201 blk_plug_device(conf->mddev->queue);
202 } else {
NeilBrown72626682005-09-09 16:23:54 -0700203 clear_bit(STRIPE_BIT_DELAY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 list_add_tail(&sh->lru, &conf->handle_list);
NeilBrown72626682005-09-09 16:23:54 -0700205 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 md_wakeup_thread(conf->mddev->thread);
207 } else {
Dan Williams600aa102008-06-28 08:32:05 +1000208 BUG_ON(stripe_operations_active(sh));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
210 atomic_dec(&conf->preread_active_stripes);
211 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
212 md_wakeup_thread(conf->mddev->thread);
213 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 atomic_dec(&conf->active_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800215 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
216 list_add_tail(&sh->lru, &conf->inactive_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 wake_up(&conf->wait_for_stripe);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -0800218 if (conf->retry_read_aligned)
219 md_wakeup_thread(conf->mddev->thread);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800220 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
222 }
223}
NeilBrownd0dabf72009-03-31 14:39:38 +1100224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225static void release_stripe(struct stripe_head *sh)
226{
227 raid5_conf_t *conf = sh->raid_conf;
228 unsigned long flags;
NeilBrown16a53ec2006-06-26 00:27:38 -0700229
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 spin_lock_irqsave(&conf->device_lock, flags);
231 __release_stripe(conf, sh);
232 spin_unlock_irqrestore(&conf->device_lock, flags);
233}
234
NeilBrownfccddba2006-01-06 00:20:33 -0800235static inline void remove_hash(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236{
Dan Williams45b42332007-07-09 11:56:43 -0700237 pr_debug("remove_hash(), stripe %llu\n",
238 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
NeilBrownfccddba2006-01-06 00:20:33 -0800240 hlist_del_init(&sh->hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241}
242
NeilBrown16a53ec2006-06-26 00:27:38 -0700243static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244{
NeilBrownfccddba2006-01-06 00:20:33 -0800245 struct hlist_head *hp = stripe_hash(conf, sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Dan Williams45b42332007-07-09 11:56:43 -0700247 pr_debug("insert_hash(), stripe %llu\n",
248 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250 CHECK_DEVLOCK();
NeilBrownfccddba2006-01-06 00:20:33 -0800251 hlist_add_head(&sh->hash, hp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
253
254
255/* find an idle stripe, make sure it is unhashed, and return it. */
256static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
257{
258 struct stripe_head *sh = NULL;
259 struct list_head *first;
260
261 CHECK_DEVLOCK();
262 if (list_empty(&conf->inactive_list))
263 goto out;
264 first = conf->inactive_list.next;
265 sh = list_entry(first, struct stripe_head, lru);
266 list_del_init(first);
267 remove_hash(sh);
268 atomic_inc(&conf->active_stripes);
269out:
270 return sh;
271}
272
273static void shrink_buffers(struct stripe_head *sh, int num)
274{
275 struct page *p;
276 int i;
277
278 for (i=0; i<num ; i++) {
279 p = sh->dev[i].page;
280 if (!p)
281 continue;
282 sh->dev[i].page = NULL;
NeilBrown2d1f3b52006-01-06 00:20:31 -0800283 put_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 }
285}
286
287static int grow_buffers(struct stripe_head *sh, int num)
288{
289 int i;
290
291 for (i=0; i<num; i++) {
292 struct page *page;
293
294 if (!(page = alloc_page(GFP_KERNEL))) {
295 return 1;
296 }
297 sh->dev[i].page = page;
298 }
299 return 0;
300}
301
NeilBrown784052e2009-03-31 15:19:07 +1100302static void raid5_build_block(struct stripe_head *sh, int i, int previous);
NeilBrown911d4ee2009-03-31 14:39:38 +1100303static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
304 struct stripe_head *sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
NeilBrownb5663ba2009-03-31 14:39:38 +1100306static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
308 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800309 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200311 BUG_ON(atomic_read(&sh->count) != 0);
312 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
Dan Williams600aa102008-06-28 08:32:05 +1000313 BUG_ON(stripe_operations_active(sh));
Dan Williamsd84e0f12007-01-02 13:52:30 -0700314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700316 pr_debug("init_stripe called, stripe %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 (unsigned long long)sh->sector);
318
319 remove_hash(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -0700320
NeilBrown86b42c72009-03-31 15:19:03 +1100321 sh->generation = conf->generation - previous;
NeilBrownb5663ba2009-03-31 14:39:38 +1100322 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 sh->sector = sector;
NeilBrown911d4ee2009-03-31 14:39:38 +1100324 stripe_set_idx(sector, conf, previous, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 sh->state = 0;
326
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800327
328 for (i = sh->disks; i--; ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 struct r5dev *dev = &sh->dev[i];
330
Dan Williamsd84e0f12007-01-02 13:52:30 -0700331 if (dev->toread || dev->read || dev->towrite || dev->written ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 test_bit(R5_LOCKED, &dev->flags)) {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700333 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 (unsigned long long)sh->sector, i, dev->toread,
Dan Williamsd84e0f12007-01-02 13:52:30 -0700335 dev->read, dev->towrite, dev->written,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 test_bit(R5_LOCKED, &dev->flags));
337 BUG();
338 }
339 dev->flags = 0;
NeilBrown784052e2009-03-31 15:19:07 +1100340 raid5_build_block(sh, i, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 }
342 insert_hash(conf, sh);
343}
344
NeilBrown86b42c72009-03-31 15:19:03 +1100345static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
346 short generation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347{
348 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -0800349 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700352 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
NeilBrownfccddba2006-01-06 00:20:33 -0800353 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
NeilBrown86b42c72009-03-31 15:19:03 +1100354 if (sh->sector == sector && sh->generation == generation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 return sh;
Dan Williams45b42332007-07-09 11:56:43 -0700356 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 return NULL;
358}
359
360static void unplug_slaves(mddev_t *mddev);
Jens Axboe165125e2007-07-24 09:28:11 +0200361static void raid5_unplug_device(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
NeilBrownb5663ba2009-03-31 14:39:38 +1100363static struct stripe_head *
364get_active_stripe(raid5_conf_t *conf, sector_t sector,
365 int previous, int noblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
367 struct stripe_head *sh;
368
Dan Williams45b42332007-07-09 11:56:43 -0700369 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371 spin_lock_irq(&conf->device_lock);
372
373 do {
NeilBrown72626682005-09-09 16:23:54 -0700374 wait_event_lock_irq(conf->wait_for_stripe,
375 conf->quiesce == 0,
376 conf->device_lock, /* nothing */);
NeilBrown86b42c72009-03-31 15:19:03 +1100377 sh = __find_stripe(conf, sector, conf->generation - previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 if (!sh) {
379 if (!conf->inactive_blocked)
380 sh = get_free_stripe(conf);
381 if (noblock && sh == NULL)
382 break;
383 if (!sh) {
384 conf->inactive_blocked = 1;
385 wait_event_lock_irq(conf->wait_for_stripe,
386 !list_empty(&conf->inactive_list) &&
NeilBrown50368052005-12-12 02:39:17 -0800387 (atomic_read(&conf->active_stripes)
388 < (conf->max_nr_stripes *3/4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 || !conf->inactive_blocked),
390 conf->device_lock,
NeilBrownf4370782006-07-10 04:44:14 -0700391 raid5_unplug_device(conf->mddev->queue)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 );
393 conf->inactive_blocked = 0;
394 } else
NeilBrownb5663ba2009-03-31 14:39:38 +1100395 init_stripe(sh, sector, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 } else {
397 if (atomic_read(&sh->count)) {
NeilBrownab69ae12009-03-31 15:26:47 +1100398 BUG_ON(!list_empty(&sh->lru)
399 && !test_bit(STRIPE_EXPANDING, &sh->state));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 } else {
401 if (!test_bit(STRIPE_HANDLE, &sh->state))
402 atomic_inc(&conf->active_stripes);
NeilBrownff4e8d92006-07-10 04:44:16 -0700403 if (list_empty(&sh->lru) &&
404 !test_bit(STRIPE_EXPANDING, &sh->state))
NeilBrown16a53ec2006-06-26 00:27:38 -0700405 BUG();
406 list_del_init(&sh->lru);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 }
408 }
409 } while (sh == NULL);
410
411 if (sh)
412 atomic_inc(&sh->count);
413
414 spin_unlock_irq(&conf->device_lock);
415 return sh;
416}
417
NeilBrown6712ecf2007-09-27 12:47:43 +0200418static void
419raid5_end_read_request(struct bio *bi, int error);
420static void
421raid5_end_write_request(struct bio *bi, int error);
Dan Williams91c00922007-01-02 13:52:30 -0700422
Dan Williamsc4e5ac02008-06-28 08:31:53 +1000423static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
Dan Williams91c00922007-01-02 13:52:30 -0700424{
425 raid5_conf_t *conf = sh->raid_conf;
426 int i, disks = sh->disks;
427
428 might_sleep();
429
430 for (i = disks; i--; ) {
431 int rw;
432 struct bio *bi;
433 mdk_rdev_t *rdev;
434 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
435 rw = WRITE;
436 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
437 rw = READ;
438 else
439 continue;
440
441 bi = &sh->dev[i].req;
442
443 bi->bi_rw = rw;
444 if (rw == WRITE)
445 bi->bi_end_io = raid5_end_write_request;
446 else
447 bi->bi_end_io = raid5_end_read_request;
448
449 rcu_read_lock();
450 rdev = rcu_dereference(conf->disks[i].rdev);
451 if (rdev && test_bit(Faulty, &rdev->flags))
452 rdev = NULL;
453 if (rdev)
454 atomic_inc(&rdev->nr_pending);
455 rcu_read_unlock();
456
457 if (rdev) {
Dan Williamsc4e5ac02008-06-28 08:31:53 +1000458 if (s->syncing || s->expanding || s->expanded)
Dan Williams91c00922007-01-02 13:52:30 -0700459 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
460
Dan Williams2b7497f2008-06-28 08:31:52 +1000461 set_bit(STRIPE_IO_STARTED, &sh->state);
462
Dan Williams91c00922007-01-02 13:52:30 -0700463 bi->bi_bdev = rdev->bdev;
464 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700465 __func__, (unsigned long long)sh->sector,
Dan Williams91c00922007-01-02 13:52:30 -0700466 bi->bi_rw, i);
467 atomic_inc(&sh->count);
468 bi->bi_sector = sh->sector + rdev->data_offset;
469 bi->bi_flags = 1 << BIO_UPTODATE;
470 bi->bi_vcnt = 1;
471 bi->bi_max_vecs = 1;
472 bi->bi_idx = 0;
473 bi->bi_io_vec = &sh->dev[i].vec;
474 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
475 bi->bi_io_vec[0].bv_offset = 0;
476 bi->bi_size = STRIPE_SIZE;
477 bi->bi_next = NULL;
478 if (rw == WRITE &&
479 test_bit(R5_ReWrite, &sh->dev[i].flags))
480 atomic_add(STRIPE_SECTORS,
481 &rdev->corrected_errors);
482 generic_make_request(bi);
483 } else {
484 if (rw == WRITE)
485 set_bit(STRIPE_DEGRADED, &sh->state);
486 pr_debug("skip op %ld on disc %d for sector %llu\n",
487 bi->bi_rw, i, (unsigned long long)sh->sector);
488 clear_bit(R5_LOCKED, &sh->dev[i].flags);
489 set_bit(STRIPE_HANDLE, &sh->state);
490 }
491 }
492}
493
494static struct dma_async_tx_descriptor *
495async_copy_data(int frombio, struct bio *bio, struct page *page,
496 sector_t sector, struct dma_async_tx_descriptor *tx)
497{
498 struct bio_vec *bvl;
499 struct page *bio_page;
500 int i;
501 int page_offset;
502
503 if (bio->bi_sector >= sector)
504 page_offset = (signed)(bio->bi_sector - sector) * 512;
505 else
506 page_offset = (signed)(sector - bio->bi_sector) * -512;
507 bio_for_each_segment(bvl, bio, i) {
508 int len = bio_iovec_idx(bio, i)->bv_len;
509 int clen;
510 int b_offset = 0;
511
512 if (page_offset < 0) {
513 b_offset = -page_offset;
514 page_offset += b_offset;
515 len -= b_offset;
516 }
517
518 if (len > 0 && page_offset + len > STRIPE_SIZE)
519 clen = STRIPE_SIZE - page_offset;
520 else
521 clen = len;
522
523 if (clen > 0) {
524 b_offset += bio_iovec_idx(bio, i)->bv_offset;
525 bio_page = bio_iovec_idx(bio, i)->bv_page;
526 if (frombio)
527 tx = async_memcpy(page, bio_page, page_offset,
528 b_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700529 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700530 tx, NULL, NULL);
531 else
532 tx = async_memcpy(bio_page, page, b_offset,
533 page_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700534 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700535 tx, NULL, NULL);
536 }
537 if (clen < len) /* hit end of page */
538 break;
539 page_offset += len;
540 }
541
542 return tx;
543}
544
545static void ops_complete_biofill(void *stripe_head_ref)
546{
547 struct stripe_head *sh = stripe_head_ref;
548 struct bio *return_bi = NULL;
549 raid5_conf_t *conf = sh->raid_conf;
Dan Williamse4d84902007-09-24 10:06:13 -0700550 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700551
Harvey Harrisone46b2722008-04-28 02:15:50 -0700552 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700553 (unsigned long long)sh->sector);
554
555 /* clear completed biofills */
Dan Williams83de75c2008-06-28 08:31:58 +1000556 spin_lock_irq(&conf->device_lock);
Dan Williams91c00922007-01-02 13:52:30 -0700557 for (i = sh->disks; i--; ) {
558 struct r5dev *dev = &sh->dev[i];
Dan Williams91c00922007-01-02 13:52:30 -0700559
560 /* acknowledge completion of a biofill operation */
Dan Williamse4d84902007-09-24 10:06:13 -0700561 /* and check if we need to reply to a read request,
562 * new R5_Wantfill requests are held off until
Dan Williams83de75c2008-06-28 08:31:58 +1000563 * !STRIPE_BIOFILL_RUN
Dan Williamse4d84902007-09-24 10:06:13 -0700564 */
565 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700566 struct bio *rbi, *rbi2;
Dan Williams91c00922007-01-02 13:52:30 -0700567
Dan Williams91c00922007-01-02 13:52:30 -0700568 BUG_ON(!dev->read);
569 rbi = dev->read;
570 dev->read = NULL;
571 while (rbi && rbi->bi_sector <
572 dev->sector + STRIPE_SECTORS) {
573 rbi2 = r5_next_bio(rbi, dev->sector);
Jens Axboe960e7392008-08-15 10:41:18 +0200574 if (!raid5_dec_bi_phys_segments(rbi)) {
Dan Williams91c00922007-01-02 13:52:30 -0700575 rbi->bi_next = return_bi;
576 return_bi = rbi;
577 }
Dan Williams91c00922007-01-02 13:52:30 -0700578 rbi = rbi2;
579 }
580 }
581 }
Dan Williams83de75c2008-06-28 08:31:58 +1000582 spin_unlock_irq(&conf->device_lock);
583 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700584
585 return_io(return_bi);
586
Dan Williamse4d84902007-09-24 10:06:13 -0700587 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700588 release_stripe(sh);
589}
590
591static void ops_run_biofill(struct stripe_head *sh)
592{
593 struct dma_async_tx_descriptor *tx = NULL;
594 raid5_conf_t *conf = sh->raid_conf;
595 int i;
596
Harvey Harrisone46b2722008-04-28 02:15:50 -0700597 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700598 (unsigned long long)sh->sector);
599
600 for (i = sh->disks; i--; ) {
601 struct r5dev *dev = &sh->dev[i];
602 if (test_bit(R5_Wantfill, &dev->flags)) {
603 struct bio *rbi;
604 spin_lock_irq(&conf->device_lock);
605 dev->read = rbi = dev->toread;
606 dev->toread = NULL;
607 spin_unlock_irq(&conf->device_lock);
608 while (rbi && rbi->bi_sector <
609 dev->sector + STRIPE_SECTORS) {
610 tx = async_copy_data(0, rbi, dev->page,
611 dev->sector, tx);
612 rbi = r5_next_bio(rbi, dev->sector);
613 }
614 }
615 }
616
617 atomic_inc(&sh->count);
618 async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
619 ops_complete_biofill, sh);
620}
621
622static void ops_complete_compute5(void *stripe_head_ref)
623{
624 struct stripe_head *sh = stripe_head_ref;
625 int target = sh->ops.target;
626 struct r5dev *tgt = &sh->dev[target];
627
Harvey Harrisone46b2722008-04-28 02:15:50 -0700628 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700629 (unsigned long long)sh->sector);
630
631 set_bit(R5_UPTODATE, &tgt->flags);
632 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
633 clear_bit(R5_Wantcompute, &tgt->flags);
Dan Williamsecc65c92008-06-28 08:31:57 +1000634 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
635 if (sh->check_state == check_state_compute_run)
636 sh->check_state = check_state_compute_result;
Dan Williams91c00922007-01-02 13:52:30 -0700637 set_bit(STRIPE_HANDLE, &sh->state);
638 release_stripe(sh);
639}
640
Dan Williams7b3a8712008-06-28 08:32:09 +1000641static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh)
Dan Williams91c00922007-01-02 13:52:30 -0700642{
643 /* kernel stack size limits the total number of disks */
644 int disks = sh->disks;
645 struct page *xor_srcs[disks];
646 int target = sh->ops.target;
647 struct r5dev *tgt = &sh->dev[target];
648 struct page *xor_dest = tgt->page;
649 int count = 0;
650 struct dma_async_tx_descriptor *tx;
651 int i;
652
653 pr_debug("%s: stripe %llu block: %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700654 __func__, (unsigned long long)sh->sector, target);
Dan Williams91c00922007-01-02 13:52:30 -0700655 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
656
657 for (i = disks; i--; )
658 if (i != target)
659 xor_srcs[count++] = sh->dev[i].page;
660
661 atomic_inc(&sh->count);
662
663 if (unlikely(count == 1))
664 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
665 0, NULL, ops_complete_compute5, sh);
666 else
667 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
668 ASYNC_TX_XOR_ZERO_DST, NULL,
669 ops_complete_compute5, sh);
670
Dan Williams91c00922007-01-02 13:52:30 -0700671 return tx;
672}
673
674static void ops_complete_prexor(void *stripe_head_ref)
675{
676 struct stripe_head *sh = stripe_head_ref;
677
Harvey Harrisone46b2722008-04-28 02:15:50 -0700678 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700679 (unsigned long long)sh->sector);
Dan Williams91c00922007-01-02 13:52:30 -0700680}
681
682static struct dma_async_tx_descriptor *
683ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
684{
685 /* kernel stack size limits the total number of disks */
686 int disks = sh->disks;
687 struct page *xor_srcs[disks];
688 int count = 0, pd_idx = sh->pd_idx, i;
689
690 /* existing parity data subtracted */
691 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
692
Harvey Harrisone46b2722008-04-28 02:15:50 -0700693 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700694 (unsigned long long)sh->sector);
695
696 for (i = disks; i--; ) {
697 struct r5dev *dev = &sh->dev[i];
698 /* Only process blocks that are known to be uptodate */
Dan Williamsd8ee0722008-06-28 08:32:06 +1000699 if (test_bit(R5_Wantdrain, &dev->flags))
Dan Williams91c00922007-01-02 13:52:30 -0700700 xor_srcs[count++] = dev->page;
701 }
702
703 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
704 ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
705 ops_complete_prexor, sh);
706
707 return tx;
708}
709
710static struct dma_async_tx_descriptor *
Dan Williamsd8ee0722008-06-28 08:32:06 +1000711ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
Dan Williams91c00922007-01-02 13:52:30 -0700712{
713 int disks = sh->disks;
Dan Williamsd8ee0722008-06-28 08:32:06 +1000714 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700715
Harvey Harrisone46b2722008-04-28 02:15:50 -0700716 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700717 (unsigned long long)sh->sector);
718
719 for (i = disks; i--; ) {
720 struct r5dev *dev = &sh->dev[i];
721 struct bio *chosen;
Dan Williams91c00922007-01-02 13:52:30 -0700722
Dan Williamsd8ee0722008-06-28 08:32:06 +1000723 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700724 struct bio *wbi;
725
726 spin_lock(&sh->lock);
727 chosen = dev->towrite;
728 dev->towrite = NULL;
729 BUG_ON(dev->written);
730 wbi = dev->written = chosen;
731 spin_unlock(&sh->lock);
732
733 while (wbi && wbi->bi_sector <
734 dev->sector + STRIPE_SECTORS) {
735 tx = async_copy_data(1, wbi, dev->page,
736 dev->sector, tx);
737 wbi = r5_next_bio(wbi, dev->sector);
738 }
739 }
740 }
741
742 return tx;
743}
744
745static void ops_complete_postxor(void *stripe_head_ref)
746{
747 struct stripe_head *sh = stripe_head_ref;
Dan Williams91c00922007-01-02 13:52:30 -0700748 int disks = sh->disks, i, pd_idx = sh->pd_idx;
749
Harvey Harrisone46b2722008-04-28 02:15:50 -0700750 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700751 (unsigned long long)sh->sector);
752
753 for (i = disks; i--; ) {
754 struct r5dev *dev = &sh->dev[i];
755 if (dev->written || i == pd_idx)
756 set_bit(R5_UPTODATE, &dev->flags);
757 }
758
Dan Williamsd8ee0722008-06-28 08:32:06 +1000759 if (sh->reconstruct_state == reconstruct_state_drain_run)
760 sh->reconstruct_state = reconstruct_state_drain_result;
761 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
762 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
763 else {
764 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
765 sh->reconstruct_state = reconstruct_state_result;
766 }
Dan Williams91c00922007-01-02 13:52:30 -0700767
768 set_bit(STRIPE_HANDLE, &sh->state);
769 release_stripe(sh);
770}
771
772static void
Dan Williamsd8ee0722008-06-28 08:32:06 +1000773ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
Dan Williams91c00922007-01-02 13:52:30 -0700774{
775 /* kernel stack size limits the total number of disks */
776 int disks = sh->disks;
777 struct page *xor_srcs[disks];
778
779 int count = 0, pd_idx = sh->pd_idx, i;
780 struct page *xor_dest;
Dan Williamsd8ee0722008-06-28 08:32:06 +1000781 int prexor = 0;
Dan Williams91c00922007-01-02 13:52:30 -0700782 unsigned long flags;
Dan Williams91c00922007-01-02 13:52:30 -0700783
Harvey Harrisone46b2722008-04-28 02:15:50 -0700784 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700785 (unsigned long long)sh->sector);
786
787 /* check if prexor is active which means only process blocks
788 * that are part of a read-modify-write (written)
789 */
Dan Williamsd8ee0722008-06-28 08:32:06 +1000790 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
791 prexor = 1;
Dan Williams91c00922007-01-02 13:52:30 -0700792 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
793 for (i = disks; i--; ) {
794 struct r5dev *dev = &sh->dev[i];
795 if (dev->written)
796 xor_srcs[count++] = dev->page;
797 }
798 } else {
799 xor_dest = sh->dev[pd_idx].page;
800 for (i = disks; i--; ) {
801 struct r5dev *dev = &sh->dev[i];
802 if (i != pd_idx)
803 xor_srcs[count++] = dev->page;
804 }
805 }
806
Dan Williams91c00922007-01-02 13:52:30 -0700807 /* 1/ if we prexor'd then the dest is reused as a source
808 * 2/ if we did not prexor then we are redoing the parity
809 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
810 * for the synchronous xor case
811 */
812 flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
813 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
814
815 atomic_inc(&sh->count);
816
817 if (unlikely(count == 1)) {
818 flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
819 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
Dan Williamsd8ee0722008-06-28 08:32:06 +1000820 flags, tx, ops_complete_postxor, sh);
Dan Williams91c00922007-01-02 13:52:30 -0700821 } else
822 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
Dan Williamsd8ee0722008-06-28 08:32:06 +1000823 flags, tx, ops_complete_postxor, sh);
Dan Williams91c00922007-01-02 13:52:30 -0700824}
825
826static void ops_complete_check(void *stripe_head_ref)
827{
828 struct stripe_head *sh = stripe_head_ref;
Dan Williams91c00922007-01-02 13:52:30 -0700829
Harvey Harrisone46b2722008-04-28 02:15:50 -0700830 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700831 (unsigned long long)sh->sector);
832
Dan Williamsecc65c92008-06-28 08:31:57 +1000833 sh->check_state = check_state_check_result;
Dan Williams91c00922007-01-02 13:52:30 -0700834 set_bit(STRIPE_HANDLE, &sh->state);
835 release_stripe(sh);
836}
837
838static void ops_run_check(struct stripe_head *sh)
839{
840 /* kernel stack size limits the total number of disks */
841 int disks = sh->disks;
842 struct page *xor_srcs[disks];
843 struct dma_async_tx_descriptor *tx;
844
845 int count = 0, pd_idx = sh->pd_idx, i;
846 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
847
Harvey Harrisone46b2722008-04-28 02:15:50 -0700848 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700849 (unsigned long long)sh->sector);
850
851 for (i = disks; i--; ) {
852 struct r5dev *dev = &sh->dev[i];
853 if (i != pd_idx)
854 xor_srcs[count++] = dev->page;
855 }
856
857 tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
858 &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
859
Dan Williams91c00922007-01-02 13:52:30 -0700860 atomic_inc(&sh->count);
861 tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
862 ops_complete_check, sh);
863}
864
Dan Williams600aa102008-06-28 08:32:05 +1000865static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
Dan Williams91c00922007-01-02 13:52:30 -0700866{
867 int overlap_clear = 0, i, disks = sh->disks;
868 struct dma_async_tx_descriptor *tx = NULL;
869
Dan Williams83de75c2008-06-28 08:31:58 +1000870 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
Dan Williams91c00922007-01-02 13:52:30 -0700871 ops_run_biofill(sh);
872 overlap_clear++;
873 }
874
Dan Williams7b3a8712008-06-28 08:32:09 +1000875 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
876 tx = ops_run_compute5(sh);
877 /* terminate the chain if postxor is not set to be run */
878 if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request))
879 async_tx_ack(tx);
880 }
Dan Williams91c00922007-01-02 13:52:30 -0700881
Dan Williams600aa102008-06-28 08:32:05 +1000882 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
Dan Williams91c00922007-01-02 13:52:30 -0700883 tx = ops_run_prexor(sh, tx);
884
Dan Williams600aa102008-06-28 08:32:05 +1000885 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
Dan Williamsd8ee0722008-06-28 08:32:06 +1000886 tx = ops_run_biodrain(sh, tx);
Dan Williams91c00922007-01-02 13:52:30 -0700887 overlap_clear++;
888 }
889
Dan Williams600aa102008-06-28 08:32:05 +1000890 if (test_bit(STRIPE_OP_POSTXOR, &ops_request))
Dan Williamsd8ee0722008-06-28 08:32:06 +1000891 ops_run_postxor(sh, tx);
Dan Williams91c00922007-01-02 13:52:30 -0700892
Dan Williamsecc65c92008-06-28 08:31:57 +1000893 if (test_bit(STRIPE_OP_CHECK, &ops_request))
Dan Williams91c00922007-01-02 13:52:30 -0700894 ops_run_check(sh);
895
Dan Williams91c00922007-01-02 13:52:30 -0700896 if (overlap_clear)
897 for (i = disks; i--; ) {
898 struct r5dev *dev = &sh->dev[i];
899 if (test_and_clear_bit(R5_Overlap, &dev->flags))
900 wake_up(&sh->raid_conf->wait_for_overlap);
901 }
902}
903
NeilBrown3f294f42005-11-08 21:39:25 -0800904static int grow_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905{
906 struct stripe_head *sh;
NeilBrown3f294f42005-11-08 21:39:25 -0800907 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
908 if (!sh)
909 return 0;
910 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
911 sh->raid_conf = conf;
912 spin_lock_init(&sh->lock);
913
914 if (grow_buffers(sh, conf->raid_disks)) {
915 shrink_buffers(sh, conf->raid_disks);
916 kmem_cache_free(conf->slab_cache, sh);
917 return 0;
918 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800919 sh->disks = conf->raid_disks;
NeilBrown3f294f42005-11-08 21:39:25 -0800920 /* we just created an active stripe so... */
921 atomic_set(&sh->count, 1);
922 atomic_inc(&conf->active_stripes);
923 INIT_LIST_HEAD(&sh->lru);
924 release_stripe(sh);
925 return 1;
926}
927
928static int grow_stripes(raid5_conf_t *conf, int num)
929{
Christoph Lametere18b8902006-12-06 20:33:20 -0800930 struct kmem_cache *sc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 int devs = conf->raid_disks;
932
NeilBrown245f46c2009-03-31 14:39:39 +1100933 sprintf(conf->cache_name[0],
934 "raid%d-%s", conf->level, mdname(conf->mddev));
935 sprintf(conf->cache_name[1],
936 "raid%d-%s-alt", conf->level, mdname(conf->mddev));
NeilBrownad01c9e2006-03-27 01:18:07 -0800937 conf->active_name = 0;
938 sc = kmem_cache_create(conf->cache_name[conf->active_name],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +0900940 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 if (!sc)
942 return 1;
943 conf->slab_cache = sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800944 conf->pool_size = devs;
NeilBrown16a53ec2006-06-26 00:27:38 -0700945 while (num--)
NeilBrown3f294f42005-11-08 21:39:25 -0800946 if (!grow_one_stripe(conf))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 return 0;
949}
NeilBrown29269552006-03-27 01:18:10 -0800950
NeilBrownad01c9e2006-03-27 01:18:07 -0800951static int resize_stripes(raid5_conf_t *conf, int newsize)
952{
953 /* Make all the stripes able to hold 'newsize' devices.
954 * New slots in each stripe get 'page' set to a new page.
955 *
956 * This happens in stages:
957 * 1/ create a new kmem_cache and allocate the required number of
958 * stripe_heads.
959 * 2/ gather all the old stripe_heads and tranfer the pages across
960 * to the new stripe_heads. This will have the side effect of
961 * freezing the array as once all stripe_heads have been collected,
962 * no IO will be possible. Old stripe heads are freed once their
963 * pages have been transferred over, and the old kmem_cache is
964 * freed when all stripes are done.
965 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
966 * we simple return a failre status - no need to clean anything up.
967 * 4/ allocate new pages for the new slots in the new stripe_heads.
968 * If this fails, we don't bother trying the shrink the
969 * stripe_heads down again, we just leave them as they are.
970 * As each stripe_head is processed the new one is released into
971 * active service.
972 *
973 * Once step2 is started, we cannot afford to wait for a write,
974 * so we use GFP_NOIO allocations.
975 */
976 struct stripe_head *osh, *nsh;
977 LIST_HEAD(newstripes);
978 struct disk_info *ndisks;
Dan Williamsb5470dc2008-06-27 21:44:04 -0700979 int err;
Christoph Lametere18b8902006-12-06 20:33:20 -0800980 struct kmem_cache *sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800981 int i;
982
983 if (newsize <= conf->pool_size)
984 return 0; /* never bother to shrink */
985
Dan Williamsb5470dc2008-06-27 21:44:04 -0700986 err = md_allow_write(conf->mddev);
987 if (err)
988 return err;
NeilBrown2a2275d2007-01-26 00:57:11 -0800989
NeilBrownad01c9e2006-03-27 01:18:07 -0800990 /* Step 1 */
991 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
992 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +0900993 0, 0, NULL);
NeilBrownad01c9e2006-03-27 01:18:07 -0800994 if (!sc)
995 return -ENOMEM;
996
997 for (i = conf->max_nr_stripes; i; i--) {
998 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
999 if (!nsh)
1000 break;
1001
1002 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1003
1004 nsh->raid_conf = conf;
1005 spin_lock_init(&nsh->lock);
1006
1007 list_add(&nsh->lru, &newstripes);
1008 }
1009 if (i) {
1010 /* didn't get enough, give up */
1011 while (!list_empty(&newstripes)) {
1012 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1013 list_del(&nsh->lru);
1014 kmem_cache_free(sc, nsh);
1015 }
1016 kmem_cache_destroy(sc);
1017 return -ENOMEM;
1018 }
1019 /* Step 2 - Must use GFP_NOIO now.
1020 * OK, we have enough stripes, start collecting inactive
1021 * stripes and copying them over
1022 */
1023 list_for_each_entry(nsh, &newstripes, lru) {
1024 spin_lock_irq(&conf->device_lock);
1025 wait_event_lock_irq(conf->wait_for_stripe,
1026 !list_empty(&conf->inactive_list),
1027 conf->device_lock,
NeilBrownb3b46be2006-03-27 01:18:16 -08001028 unplug_slaves(conf->mddev)
NeilBrownad01c9e2006-03-27 01:18:07 -08001029 );
1030 osh = get_free_stripe(conf);
1031 spin_unlock_irq(&conf->device_lock);
1032 atomic_set(&nsh->count, 1);
1033 for(i=0; i<conf->pool_size; i++)
1034 nsh->dev[i].page = osh->dev[i].page;
1035 for( ; i<newsize; i++)
1036 nsh->dev[i].page = NULL;
1037 kmem_cache_free(conf->slab_cache, osh);
1038 }
1039 kmem_cache_destroy(conf->slab_cache);
1040
1041 /* Step 3.
1042 * At this point, we are holding all the stripes so the array
1043 * is completely stalled, so now is a good time to resize
1044 * conf->disks.
1045 */
1046 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1047 if (ndisks) {
1048 for (i=0; i<conf->raid_disks; i++)
1049 ndisks[i] = conf->disks[i];
1050 kfree(conf->disks);
1051 conf->disks = ndisks;
1052 } else
1053 err = -ENOMEM;
1054
1055 /* Step 4, return new stripes to service */
1056 while(!list_empty(&newstripes)) {
1057 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1058 list_del_init(&nsh->lru);
1059 for (i=conf->raid_disks; i < newsize; i++)
1060 if (nsh->dev[i].page == NULL) {
1061 struct page *p = alloc_page(GFP_NOIO);
1062 nsh->dev[i].page = p;
1063 if (!p)
1064 err = -ENOMEM;
1065 }
1066 release_stripe(nsh);
1067 }
1068 /* critical section pass, GFP_NOIO no longer needed */
1069
1070 conf->slab_cache = sc;
1071 conf->active_name = 1-conf->active_name;
1072 conf->pool_size = newsize;
1073 return err;
1074}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075
NeilBrown3f294f42005-11-08 21:39:25 -08001076static int drop_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077{
1078 struct stripe_head *sh;
1079
NeilBrown3f294f42005-11-08 21:39:25 -08001080 spin_lock_irq(&conf->device_lock);
1081 sh = get_free_stripe(conf);
1082 spin_unlock_irq(&conf->device_lock);
1083 if (!sh)
1084 return 0;
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001085 BUG_ON(atomic_read(&sh->count));
NeilBrownad01c9e2006-03-27 01:18:07 -08001086 shrink_buffers(sh, conf->pool_size);
NeilBrown3f294f42005-11-08 21:39:25 -08001087 kmem_cache_free(conf->slab_cache, sh);
1088 atomic_dec(&conf->active_stripes);
1089 return 1;
1090}
1091
1092static void shrink_stripes(raid5_conf_t *conf)
1093{
1094 while (drop_one_stripe(conf))
1095 ;
1096
NeilBrown29fc7e32006-02-03 03:03:41 -08001097 if (conf->slab_cache)
1098 kmem_cache_destroy(conf->slab_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 conf->slab_cache = NULL;
1100}
1101
NeilBrown6712ecf2007-09-27 12:47:43 +02001102static void raid5_end_read_request(struct bio * bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103{
NeilBrown99c0fb52009-03-31 14:39:38 +11001104 struct stripe_head *sh = bi->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001106 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
NeilBrownd6950432006-07-10 04:44:20 -07001108 char b[BDEVNAME_SIZE];
1109 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
1112 for (i=0 ; i<disks; i++)
1113 if (bi == &sh->dev[i].req)
1114 break;
1115
Dan Williams45b42332007-07-09 11:56:43 -07001116 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1117 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118 uptodate);
1119 if (i == disks) {
1120 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001121 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 }
1123
1124 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 set_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrown4e5314b2005-11-08 21:39:22 -08001126 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrownd6950432006-07-10 04:44:20 -07001127 rdev = conf->disks[i].rdev;
Bernd Schubert6be9d492008-05-23 13:04:34 -07001128 printk_rl(KERN_INFO "raid5:%s: read error corrected"
1129 " (%lu sectors at %llu on %s)\n",
1130 mdname(conf->mddev), STRIPE_SECTORS,
1131 (unsigned long long)(sh->sector
1132 + rdev->data_offset),
1133 bdevname(rdev->bdev, b));
NeilBrown4e5314b2005-11-08 21:39:22 -08001134 clear_bit(R5_ReadError, &sh->dev[i].flags);
1135 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1136 }
NeilBrownba22dcb2005-11-08 21:39:31 -08001137 if (atomic_read(&conf->disks[i].rdev->read_errors))
1138 atomic_set(&conf->disks[i].rdev->read_errors, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 } else {
NeilBrownd6950432006-07-10 04:44:20 -07001140 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
NeilBrownba22dcb2005-11-08 21:39:31 -08001141 int retry = 0;
NeilBrownd6950432006-07-10 04:44:20 -07001142 rdev = conf->disks[i].rdev;
1143
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001145 atomic_inc(&rdev->read_errors);
NeilBrownba22dcb2005-11-08 21:39:31 -08001146 if (conf->mddev->degraded)
Bernd Schubert6be9d492008-05-23 13:04:34 -07001147 printk_rl(KERN_WARNING
1148 "raid5:%s: read error not correctable "
1149 "(sector %llu on %s).\n",
1150 mdname(conf->mddev),
1151 (unsigned long long)(sh->sector
1152 + rdev->data_offset),
1153 bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001154 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
NeilBrown4e5314b2005-11-08 21:39:22 -08001155 /* Oh, no!!! */
Bernd Schubert6be9d492008-05-23 13:04:34 -07001156 printk_rl(KERN_WARNING
1157 "raid5:%s: read error NOT corrected!! "
1158 "(sector %llu on %s).\n",
1159 mdname(conf->mddev),
1160 (unsigned long long)(sh->sector
1161 + rdev->data_offset),
1162 bdn);
NeilBrownd6950432006-07-10 04:44:20 -07001163 else if (atomic_read(&rdev->read_errors)
NeilBrownba22dcb2005-11-08 21:39:31 -08001164 > conf->max_nr_stripes)
NeilBrown14f8d262006-01-06 00:20:14 -08001165 printk(KERN_WARNING
NeilBrownd6950432006-07-10 04:44:20 -07001166 "raid5:%s: Too many read errors, failing device %s.\n",
1167 mdname(conf->mddev), bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001168 else
1169 retry = 1;
1170 if (retry)
1171 set_bit(R5_ReadError, &sh->dev[i].flags);
1172 else {
NeilBrown4e5314b2005-11-08 21:39:22 -08001173 clear_bit(R5_ReadError, &sh->dev[i].flags);
1174 clear_bit(R5_ReWrite, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001175 md_error(conf->mddev, rdev);
NeilBrownba22dcb2005-11-08 21:39:31 -08001176 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 }
1178 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1180 set_bit(STRIPE_HANDLE, &sh->state);
1181 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182}
1183
NeilBrownd710e132008-10-13 11:55:12 +11001184static void raid5_end_write_request(struct bio *bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185{
NeilBrown99c0fb52009-03-31 14:39:38 +11001186 struct stripe_head *sh = bi->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001188 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1190
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 for (i=0 ; i<disks; i++)
1192 if (bi == &sh->dev[i].req)
1193 break;
1194
Dan Williams45b42332007-07-09 11:56:43 -07001195 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1197 uptodate);
1198 if (i == disks) {
1199 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001200 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 }
1202
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 if (!uptodate)
1204 md_error(conf->mddev, conf->disks[i].rdev);
1205
1206 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1207
1208 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1209 set_bit(STRIPE_HANDLE, &sh->state);
NeilBrownc04be0a2006-10-03 01:15:53 -07001210 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211}
1212
1213
NeilBrown784052e2009-03-31 15:19:07 +11001214static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215
NeilBrown784052e2009-03-31 15:19:07 +11001216static void raid5_build_block(struct stripe_head *sh, int i, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217{
1218 struct r5dev *dev = &sh->dev[i];
1219
1220 bio_init(&dev->req);
1221 dev->req.bi_io_vec = &dev->vec;
1222 dev->req.bi_vcnt++;
1223 dev->req.bi_max_vecs++;
1224 dev->vec.bv_page = dev->page;
1225 dev->vec.bv_len = STRIPE_SIZE;
1226 dev->vec.bv_offset = 0;
1227
1228 dev->req.bi_sector = sh->sector;
1229 dev->req.bi_private = sh;
1230
1231 dev->flags = 0;
NeilBrown784052e2009-03-31 15:19:07 +11001232 dev->sector = compute_blocknr(sh, i, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233}
1234
1235static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1236{
1237 char b[BDEVNAME_SIZE];
1238 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
Dan Williams45b42332007-07-09 11:56:43 -07001239 pr_debug("raid5: error called\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
NeilBrownb2d444d2005-11-08 21:39:31 -08001241 if (!test_bit(Faulty, &rdev->flags)) {
NeilBrown850b2b42006-10-03 01:15:46 -07001242 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownc04be0a2006-10-03 01:15:53 -07001243 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1244 unsigned long flags;
1245 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001247 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 /*
1249 * if recovery was running, make sure it aborts.
1250 */
NeilBrowndfc70642008-05-23 13:04:39 -07001251 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001253 set_bit(Faulty, &rdev->flags);
NeilBrownd710e132008-10-13 11:55:12 +11001254 printk(KERN_ALERT
1255 "raid5: Disk failure on %s, disabling device.\n"
1256 "raid5: Operation continuing on %d devices.\n",
1257 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 }
NeilBrown16a53ec2006-06-26 00:27:38 -07001259}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260
1261/*
1262 * Input: a 'big' sector number,
1263 * Output: index of the data and parity disk, and the sector # in them.
1264 */
NeilBrown112bf892009-03-31 14:39:38 +11001265static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
NeilBrown911d4ee2009-03-31 14:39:38 +11001266 int previous, int *dd_idx,
1267 struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268{
1269 long stripe;
1270 unsigned long chunk_number;
1271 unsigned int chunk_offset;
NeilBrown911d4ee2009-03-31 14:39:38 +11001272 int pd_idx, qd_idx;
NeilBrown67cc2b82009-03-31 14:39:38 +11001273 int ddf_layout = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 sector_t new_sector;
NeilBrowne183eae2009-03-31 15:20:22 +11001275 int algorithm = previous ? conf->prev_algo
1276 : conf->algorithm;
NeilBrown784052e2009-03-31 15:19:07 +11001277 int sectors_per_chunk = previous ? (conf->prev_chunk >> 9)
1278 : (conf->chunk_size >> 9);
NeilBrown112bf892009-03-31 14:39:38 +11001279 int raid_disks = previous ? conf->previous_raid_disks
1280 : conf->raid_disks;
1281 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282
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 */
NeilBrown911d4ee2009-03-31 14:39:38 +11001305 pd_idx = qd_idx = ~0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001306 switch(conf->level) {
1307 case 4:
NeilBrown911d4ee2009-03-31 14:39:38 +11001308 pd_idx = data_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001309 break;
1310 case 5:
NeilBrowne183eae2009-03-31 15:20:22 +11001311 switch (algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 case ALGORITHM_LEFT_ASYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001313 pd_idx = data_disks - stripe % raid_disks;
1314 if (*dd_idx >= pd_idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 (*dd_idx)++;
1316 break;
1317 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001318 pd_idx = stripe % raid_disks;
1319 if (*dd_idx >= pd_idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 (*dd_idx)++;
1321 break;
1322 case ALGORITHM_LEFT_SYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001323 pd_idx = data_disks - stripe % raid_disks;
1324 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 break;
1326 case ALGORITHM_RIGHT_SYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001327 pd_idx = stripe % raid_disks;
1328 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001330 case ALGORITHM_PARITY_0:
1331 pd_idx = 0;
1332 (*dd_idx)++;
1333 break;
1334 case ALGORITHM_PARITY_N:
1335 pd_idx = data_disks;
1336 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001338 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
NeilBrowne183eae2009-03-31 15:20:22 +11001339 algorithm);
NeilBrown99c0fb52009-03-31 14:39:38 +11001340 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001341 }
1342 break;
1343 case 6:
1344
NeilBrowne183eae2009-03-31 15:20:22 +11001345 switch (algorithm) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001346 case ALGORITHM_LEFT_ASYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001347 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1348 qd_idx = pd_idx + 1;
1349 if (pd_idx == raid_disks-1) {
NeilBrown99c0fb52009-03-31 14:39:38 +11001350 (*dd_idx)++; /* Q D D D P */
NeilBrown911d4ee2009-03-31 14:39:38 +11001351 qd_idx = 0;
1352 } else if (*dd_idx >= pd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001353 (*dd_idx) += 2; /* D D P Q D */
1354 break;
1355 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001356 pd_idx = stripe % raid_disks;
1357 qd_idx = pd_idx + 1;
1358 if (pd_idx == raid_disks-1) {
NeilBrown99c0fb52009-03-31 14:39:38 +11001359 (*dd_idx)++; /* Q D D D P */
NeilBrown911d4ee2009-03-31 14:39:38 +11001360 qd_idx = 0;
1361 } else if (*dd_idx >= pd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001362 (*dd_idx) += 2; /* D D P Q D */
1363 break;
1364 case ALGORITHM_LEFT_SYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001365 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1366 qd_idx = (pd_idx + 1) % raid_disks;
1367 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001368 break;
1369 case ALGORITHM_RIGHT_SYMMETRIC:
NeilBrown911d4ee2009-03-31 14:39:38 +11001370 pd_idx = stripe % raid_disks;
1371 qd_idx = (pd_idx + 1) % raid_disks;
1372 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001373 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001374
1375 case ALGORITHM_PARITY_0:
1376 pd_idx = 0;
1377 qd_idx = 1;
1378 (*dd_idx) += 2;
1379 break;
1380 case ALGORITHM_PARITY_N:
1381 pd_idx = data_disks;
1382 qd_idx = data_disks + 1;
1383 break;
1384
1385 case ALGORITHM_ROTATING_ZERO_RESTART:
1386 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1387 * of blocks for computing Q is different.
1388 */
1389 pd_idx = stripe % raid_disks;
1390 qd_idx = pd_idx + 1;
1391 if (pd_idx == raid_disks-1) {
1392 (*dd_idx)++; /* Q D D D P */
1393 qd_idx = 0;
1394 } else if (*dd_idx >= pd_idx)
1395 (*dd_idx) += 2; /* D D P Q D */
NeilBrown67cc2b82009-03-31 14:39:38 +11001396 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001397 break;
1398
1399 case ALGORITHM_ROTATING_N_RESTART:
1400 /* Same a left_asymmetric, by first stripe is
1401 * D D D P Q rather than
1402 * Q D D D P
1403 */
1404 pd_idx = raid_disks - 1 - ((stripe + 1) % raid_disks);
1405 qd_idx = pd_idx + 1;
1406 if (pd_idx == raid_disks-1) {
1407 (*dd_idx)++; /* Q D D D P */
1408 qd_idx = 0;
1409 } else if (*dd_idx >= pd_idx)
1410 (*dd_idx) += 2; /* D D P Q D */
NeilBrown67cc2b82009-03-31 14:39:38 +11001411 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001412 break;
1413
1414 case ALGORITHM_ROTATING_N_CONTINUE:
1415 /* Same as left_symmetric but Q is before P */
1416 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1417 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1418 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
NeilBrown67cc2b82009-03-31 14:39:38 +11001419 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001420 break;
1421
1422 case ALGORITHM_LEFT_ASYMMETRIC_6:
1423 /* RAID5 left_asymmetric, with Q on last device */
1424 pd_idx = data_disks - stripe % (raid_disks-1);
1425 if (*dd_idx >= pd_idx)
1426 (*dd_idx)++;
1427 qd_idx = raid_disks - 1;
1428 break;
1429
1430 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1431 pd_idx = stripe % (raid_disks-1);
1432 if (*dd_idx >= pd_idx)
1433 (*dd_idx)++;
1434 qd_idx = raid_disks - 1;
1435 break;
1436
1437 case ALGORITHM_LEFT_SYMMETRIC_6:
1438 pd_idx = data_disks - stripe % (raid_disks-1);
1439 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1440 qd_idx = raid_disks - 1;
1441 break;
1442
1443 case ALGORITHM_RIGHT_SYMMETRIC_6:
1444 pd_idx = stripe % (raid_disks-1);
1445 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1446 qd_idx = raid_disks - 1;
1447 break;
1448
1449 case ALGORITHM_PARITY_0_6:
1450 pd_idx = 0;
1451 (*dd_idx)++;
1452 qd_idx = raid_disks - 1;
1453 break;
1454
1455
NeilBrown16a53ec2006-06-26 00:27:38 -07001456 default:
NeilBrownd710e132008-10-13 11:55:12 +11001457 printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
NeilBrowne183eae2009-03-31 15:20:22 +11001458 algorithm);
NeilBrown99c0fb52009-03-31 14:39:38 +11001459 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001460 }
1461 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 }
1463
NeilBrown911d4ee2009-03-31 14:39:38 +11001464 if (sh) {
1465 sh->pd_idx = pd_idx;
1466 sh->qd_idx = qd_idx;
NeilBrown67cc2b82009-03-31 14:39:38 +11001467 sh->ddf_layout = ddf_layout;
NeilBrown911d4ee2009-03-31 14:39:38 +11001468 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001469 /*
1470 * Finally, compute the new sector number
1471 */
1472 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1473 return new_sector;
1474}
1475
1476
NeilBrown784052e2009-03-31 15:19:07 +11001477static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478{
1479 raid5_conf_t *conf = sh->raid_conf;
NeilBrownb875e532006-12-10 02:20:49 -08001480 int raid_disks = sh->disks;
1481 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 sector_t new_sector = sh->sector, check;
NeilBrown784052e2009-03-31 15:19:07 +11001483 int sectors_per_chunk = previous ? (conf->prev_chunk >> 9)
1484 : (conf->chunk_size >> 9);
NeilBrowne183eae2009-03-31 15:20:22 +11001485 int algorithm = previous ? conf->prev_algo
1486 : conf->algorithm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 sector_t stripe;
1488 int chunk_offset;
NeilBrown911d4ee2009-03-31 14:39:38 +11001489 int chunk_number, dummy1, dd_idx = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 sector_t r_sector;
NeilBrown911d4ee2009-03-31 14:39:38 +11001491 struct stripe_head sh2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
NeilBrown16a53ec2006-06-26 00:27:38 -07001493
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1495 stripe = new_sector;
1496 BUG_ON(new_sector != stripe);
1497
NeilBrown16a53ec2006-06-26 00:27:38 -07001498 if (i == sh->pd_idx)
1499 return 0;
1500 switch(conf->level) {
1501 case 4: break;
1502 case 5:
NeilBrowne183eae2009-03-31 15:20:22 +11001503 switch (algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 case ALGORITHM_LEFT_ASYMMETRIC:
1505 case ALGORITHM_RIGHT_ASYMMETRIC:
1506 if (i > sh->pd_idx)
1507 i--;
1508 break;
1509 case ALGORITHM_LEFT_SYMMETRIC:
1510 case ALGORITHM_RIGHT_SYMMETRIC:
1511 if (i < sh->pd_idx)
1512 i += raid_disks;
1513 i -= (sh->pd_idx + 1);
1514 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001515 case ALGORITHM_PARITY_0:
1516 i -= 1;
1517 break;
1518 case ALGORITHM_PARITY_N:
1519 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001521 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
NeilBrowne183eae2009-03-31 15:20:22 +11001522 algorithm);
NeilBrown99c0fb52009-03-31 14:39:38 +11001523 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001524 }
1525 break;
1526 case 6:
NeilBrownd0dabf72009-03-31 14:39:38 +11001527 if (i == sh->qd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001528 return 0; /* It is the Q disk */
NeilBrowne183eae2009-03-31 15:20:22 +11001529 switch (algorithm) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001530 case ALGORITHM_LEFT_ASYMMETRIC:
1531 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown99c0fb52009-03-31 14:39:38 +11001532 case ALGORITHM_ROTATING_ZERO_RESTART:
1533 case ALGORITHM_ROTATING_N_RESTART:
1534 if (sh->pd_idx == raid_disks-1)
1535 i--; /* Q D D D P */
NeilBrown16a53ec2006-06-26 00:27:38 -07001536 else if (i > sh->pd_idx)
1537 i -= 2; /* D D P Q D */
1538 break;
1539 case ALGORITHM_LEFT_SYMMETRIC:
1540 case ALGORITHM_RIGHT_SYMMETRIC:
1541 if (sh->pd_idx == raid_disks-1)
1542 i--; /* Q D D D P */
1543 else {
1544 /* D D P Q D */
1545 if (i < sh->pd_idx)
1546 i += raid_disks;
1547 i -= (sh->pd_idx + 2);
1548 }
1549 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001550 case ALGORITHM_PARITY_0:
1551 i -= 2;
1552 break;
1553 case ALGORITHM_PARITY_N:
1554 break;
1555 case ALGORITHM_ROTATING_N_CONTINUE:
1556 if (sh->pd_idx == 0)
1557 i--; /* P D D D Q */
1558 else if (i > sh->pd_idx)
1559 i -= 2; /* D D Q P D */
1560 break;
1561 case ALGORITHM_LEFT_ASYMMETRIC_6:
1562 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1563 if (i > sh->pd_idx)
1564 i--;
1565 break;
1566 case ALGORITHM_LEFT_SYMMETRIC_6:
1567 case ALGORITHM_RIGHT_SYMMETRIC_6:
1568 if (i < sh->pd_idx)
1569 i += data_disks + 1;
1570 i -= (sh->pd_idx + 1);
1571 break;
1572 case ALGORITHM_PARITY_0_6:
1573 i -= 1;
1574 break;
NeilBrown16a53ec2006-06-26 00:27:38 -07001575 default:
NeilBrownd710e132008-10-13 11:55:12 +11001576 printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
NeilBrowne183eae2009-03-31 15:20:22 +11001577 algorithm);
NeilBrown99c0fb52009-03-31 14:39:38 +11001578 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001579 }
1580 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 }
1582
1583 chunk_number = stripe * data_disks + i;
1584 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
1585
NeilBrown112bf892009-03-31 14:39:38 +11001586 check = raid5_compute_sector(conf, r_sector,
NeilBrown784052e2009-03-31 15:19:07 +11001587 previous, &dummy1, &sh2);
NeilBrown911d4ee2009-03-31 14:39:38 +11001588 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
1589 || sh2.qd_idx != sh->qd_idx) {
NeilBrown14f8d262006-01-06 00:20:14 -08001590 printk(KERN_ERR "compute_blocknr: map not correct\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591 return 0;
1592 }
1593 return r_sector;
1594}
1595
1596
1597
1598/*
NeilBrown16a53ec2006-06-26 00:27:38 -07001599 * Copy data between a page in the stripe cache, and one or more bion
1600 * The page could align with the middle of the bio, or there could be
1601 * several bion, each with several bio_vecs, which cover part of the page
1602 * Multiple bion are linked together on bi_next. There may be extras
1603 * at the end of this list. We ignore them.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 */
1605static void copy_data(int frombio, struct bio *bio,
1606 struct page *page,
1607 sector_t sector)
1608{
1609 char *pa = page_address(page);
1610 struct bio_vec *bvl;
1611 int i;
1612 int page_offset;
1613
1614 if (bio->bi_sector >= sector)
1615 page_offset = (signed)(bio->bi_sector - sector) * 512;
1616 else
1617 page_offset = (signed)(sector - bio->bi_sector) * -512;
1618 bio_for_each_segment(bvl, bio, i) {
1619 int len = bio_iovec_idx(bio,i)->bv_len;
1620 int clen;
1621 int b_offset = 0;
1622
1623 if (page_offset < 0) {
1624 b_offset = -page_offset;
1625 page_offset += b_offset;
1626 len -= b_offset;
1627 }
1628
1629 if (len > 0 && page_offset + len > STRIPE_SIZE)
1630 clen = STRIPE_SIZE - page_offset;
1631 else clen = len;
NeilBrown16a53ec2006-06-26 00:27:38 -07001632
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 if (clen > 0) {
1634 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
1635 if (frombio)
1636 memcpy(pa+page_offset, ba+b_offset, clen);
1637 else
1638 memcpy(ba+b_offset, pa+page_offset, clen);
1639 __bio_kunmap_atomic(ba, KM_USER0);
1640 }
1641 if (clen < len) /* hit end of page */
1642 break;
1643 page_offset += len;
1644 }
1645}
1646
Dan Williams9bc89cd2007-01-02 11:10:44 -07001647#define check_xor() do { \
1648 if (count == MAX_XOR_BLOCKS) { \
1649 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1650 count = 0; \
1651 } \
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 } while(0)
1653
NeilBrown16a53ec2006-06-26 00:27:38 -07001654static void compute_parity6(struct stripe_head *sh, int method)
1655{
NeilBrownbff61972009-03-31 14:33:13 +11001656 raid5_conf_t *conf = sh->raid_conf;
NeilBrownd0dabf72009-03-31 14:39:38 +11001657 int i, pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
NeilBrown67cc2b82009-03-31 14:39:38 +11001658 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
NeilBrown16a53ec2006-06-26 00:27:38 -07001659 struct bio *chosen;
1660 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
NeilBrown67cc2b82009-03-31 14:39:38 +11001661 void *ptrs[syndrome_disks+2];
NeilBrown16a53ec2006-06-26 00:27:38 -07001662
NeilBrownd0dabf72009-03-31 14:39:38 +11001663 pd_idx = sh->pd_idx;
1664 qd_idx = sh->qd_idx;
1665 d0_idx = raid6_d0(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -07001666
Dan Williams45b42332007-07-09 11:56:43 -07001667 pr_debug("compute_parity, stripe %llu, method %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001668 (unsigned long long)sh->sector, method);
1669
1670 switch(method) {
1671 case READ_MODIFY_WRITE:
1672 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1673 case RECONSTRUCT_WRITE:
1674 for (i= disks; i-- ;)
1675 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1676 chosen = sh->dev[i].towrite;
1677 sh->dev[i].towrite = NULL;
1678
1679 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1680 wake_up(&conf->wait_for_overlap);
1681
Eric Sesterhenn52e5f9d2006-10-03 23:33:23 +02001682 BUG_ON(sh->dev[i].written);
NeilBrown16a53ec2006-06-26 00:27:38 -07001683 sh->dev[i].written = chosen;
1684 }
1685 break;
1686 case CHECK_PARITY:
1687 BUG(); /* Not implemented yet */
1688 }
1689
1690 for (i = disks; i--;)
1691 if (sh->dev[i].written) {
1692 sector_t sector = sh->dev[i].sector;
1693 struct bio *wbi = sh->dev[i].written;
1694 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1695 copy_data(1, wbi, sh->dev[i].page, sector);
1696 wbi = r5_next_bio(wbi, sector);
1697 }
1698
1699 set_bit(R5_LOCKED, &sh->dev[i].flags);
1700 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1701 }
1702
NeilBrownd0dabf72009-03-31 14:39:38 +11001703 /* Note that unlike RAID-5, the ordering of the disks matters greatly.*/
NeilBrown67cc2b82009-03-31 14:39:38 +11001704
1705 for (i = 0; i < disks; i++)
1706 ptrs[i] = (void *)raid6_empty_zero_page;
1707
NeilBrownd0dabf72009-03-31 14:39:38 +11001708 count = 0;
1709 i = d0_idx;
1710 do {
NeilBrown67cc2b82009-03-31 14:39:38 +11001711 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1712
NeilBrownd0dabf72009-03-31 14:39:38 +11001713 ptrs[slot] = page_address(sh->dev[i].page);
NeilBrown67cc2b82009-03-31 14:39:38 +11001714 if (slot < syndrome_disks &&
NeilBrownd0dabf72009-03-31 14:39:38 +11001715 !test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
1716 printk(KERN_ERR "block %d/%d not uptodate "
1717 "on parity calc\n", i, count);
1718 BUG();
1719 }
NeilBrown67cc2b82009-03-31 14:39:38 +11001720
NeilBrownd0dabf72009-03-31 14:39:38 +11001721 i = raid6_next_disk(i, disks);
1722 } while (i != d0_idx);
NeilBrown67cc2b82009-03-31 14:39:38 +11001723 BUG_ON(count != syndrome_disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07001724
NeilBrown67cc2b82009-03-31 14:39:38 +11001725 raid6_call.gen_syndrome(syndrome_disks+2, STRIPE_SIZE, ptrs);
NeilBrown16a53ec2006-06-26 00:27:38 -07001726
1727 switch(method) {
1728 case RECONSTRUCT_WRITE:
1729 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1730 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1731 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1732 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1733 break;
1734 case UPDATE_PARITY:
1735 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1736 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1737 break;
1738 }
1739}
1740
1741
1742/* Compute one missing block */
1743static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1744{
NeilBrownf4168852007-02-28 20:11:53 -08001745 int i, count, disks = sh->disks;
Dan Williams9bc89cd2007-01-02 11:10:44 -07001746 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
NeilBrownd0dabf72009-03-31 14:39:38 +11001747 int qd_idx = sh->qd_idx;
NeilBrown16a53ec2006-06-26 00:27:38 -07001748
Dan Williams45b42332007-07-09 11:56:43 -07001749 pr_debug("compute_block_1, stripe %llu, idx %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001750 (unsigned long long)sh->sector, dd_idx);
1751
1752 if ( dd_idx == qd_idx ) {
1753 /* We're actually computing the Q drive */
1754 compute_parity6(sh, UPDATE_PARITY);
1755 } else {
Dan Williams9bc89cd2007-01-02 11:10:44 -07001756 dest = page_address(sh->dev[dd_idx].page);
1757 if (!nozero) memset(dest, 0, STRIPE_SIZE);
1758 count = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001759 for (i = disks ; i--; ) {
1760 if (i == dd_idx || i == qd_idx)
1761 continue;
1762 p = page_address(sh->dev[i].page);
1763 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1764 ptr[count++] = p;
1765 else
1766 printk("compute_block() %d, stripe %llu, %d"
1767 " not present\n", dd_idx,
1768 (unsigned long long)sh->sector, i);
1769
1770 check_xor();
1771 }
Dan Williams9bc89cd2007-01-02 11:10:44 -07001772 if (count)
1773 xor_blocks(count, STRIPE_SIZE, dest, ptr);
NeilBrown16a53ec2006-06-26 00:27:38 -07001774 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1775 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1776 }
1777}
1778
1779/* Compute two missing blocks */
1780static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1781{
NeilBrownf4168852007-02-28 20:11:53 -08001782 int i, count, disks = sh->disks;
NeilBrown67cc2b82009-03-31 14:39:38 +11001783 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
NeilBrownd0dabf72009-03-31 14:39:38 +11001784 int d0_idx = raid6_d0(sh);
1785 int faila = -1, failb = -1;
1786 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
NeilBrown67cc2b82009-03-31 14:39:38 +11001787 void *ptrs[syndrome_disks+2];
NeilBrown16a53ec2006-06-26 00:27:38 -07001788
NeilBrown67cc2b82009-03-31 14:39:38 +11001789 for (i = 0; i < disks ; i++)
1790 ptrs[i] = (void *)raid6_empty_zero_page;
NeilBrownd0dabf72009-03-31 14:39:38 +11001791 count = 0;
1792 i = d0_idx;
1793 do {
NeilBrown67cc2b82009-03-31 14:39:38 +11001794 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1795
NeilBrownd0dabf72009-03-31 14:39:38 +11001796 ptrs[slot] = page_address(sh->dev[i].page);
NeilBrown67cc2b82009-03-31 14:39:38 +11001797
NeilBrownd0dabf72009-03-31 14:39:38 +11001798 if (i == dd_idx1)
1799 faila = slot;
1800 if (i == dd_idx2)
1801 failb = slot;
1802 i = raid6_next_disk(i, disks);
1803 } while (i != d0_idx);
NeilBrown67cc2b82009-03-31 14:39:38 +11001804 BUG_ON(count != syndrome_disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07001805
1806 BUG_ON(faila == failb);
1807 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1808
Dan Williams45b42332007-07-09 11:56:43 -07001809 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
NeilBrownd0dabf72009-03-31 14:39:38 +11001810 (unsigned long long)sh->sector, dd_idx1, dd_idx2,
1811 faila, failb);
NeilBrown16a53ec2006-06-26 00:27:38 -07001812
NeilBrown67cc2b82009-03-31 14:39:38 +11001813 if (failb == syndrome_disks+1) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001814 /* Q disk is one of the missing disks */
NeilBrown67cc2b82009-03-31 14:39:38 +11001815 if (faila == syndrome_disks) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001816 /* Missing P+Q, just recompute */
1817 compute_parity6(sh, UPDATE_PARITY);
1818 return;
1819 } else {
1820 /* We're missing D+Q; recompute D from P */
NeilBrownd0dabf72009-03-31 14:39:38 +11001821 compute_block_1(sh, ((dd_idx1 == sh->qd_idx) ?
1822 dd_idx2 : dd_idx1),
1823 0);
NeilBrown16a53ec2006-06-26 00:27:38 -07001824 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1825 return;
1826 }
1827 }
1828
NeilBrownd0dabf72009-03-31 14:39:38 +11001829 /* We're missing D+P or D+D; */
NeilBrown67cc2b82009-03-31 14:39:38 +11001830 if (failb == syndrome_disks) {
NeilBrownd0dabf72009-03-31 14:39:38 +11001831 /* We're missing D+P. */
NeilBrown67cc2b82009-03-31 14:39:38 +11001832 raid6_datap_recov(syndrome_disks+2, STRIPE_SIZE, faila, ptrs);
NeilBrownd0dabf72009-03-31 14:39:38 +11001833 } else {
1834 /* We're missing D+D. */
NeilBrown67cc2b82009-03-31 14:39:38 +11001835 raid6_2data_recov(syndrome_disks+2, STRIPE_SIZE, faila, failb,
1836 ptrs);
NeilBrown16a53ec2006-06-26 00:27:38 -07001837 }
NeilBrownd0dabf72009-03-31 14:39:38 +11001838
1839 /* Both the above update both missing blocks */
1840 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1841 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
NeilBrown16a53ec2006-06-26 00:27:38 -07001842}
1843
Dan Williams600aa102008-06-28 08:32:05 +10001844static void
Dan Williams1fe797e2008-06-28 09:16:30 +10001845schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
Dan Williams600aa102008-06-28 08:32:05 +10001846 int rcw, int expand)
Dan Williamse33129d2007-01-02 13:52:30 -07001847{
1848 int i, pd_idx = sh->pd_idx, disks = sh->disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001849
Dan Williamse33129d2007-01-02 13:52:30 -07001850 if (rcw) {
1851 /* if we are not expanding this is a proper write request, and
1852 * there will be bios with new data to be drained into the
1853 * stripe cache
1854 */
1855 if (!expand) {
Dan Williams600aa102008-06-28 08:32:05 +10001856 sh->reconstruct_state = reconstruct_state_drain_run;
1857 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
1858 } else
1859 sh->reconstruct_state = reconstruct_state_run;
Dan Williamse33129d2007-01-02 13:52:30 -07001860
Dan Williams600aa102008-06-28 08:32:05 +10001861 set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07001862
1863 for (i = disks; i--; ) {
1864 struct r5dev *dev = &sh->dev[i];
1865
1866 if (dev->towrite) {
1867 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsd8ee0722008-06-28 08:32:06 +10001868 set_bit(R5_Wantdrain, &dev->flags);
Dan Williamse33129d2007-01-02 13:52:30 -07001869 if (!expand)
1870 clear_bit(R5_UPTODATE, &dev->flags);
Dan Williams600aa102008-06-28 08:32:05 +10001871 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07001872 }
1873 }
Dan Williams600aa102008-06-28 08:32:05 +10001874 if (s->locked + 1 == disks)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07001875 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
1876 atomic_inc(&sh->raid_conf->pending_full_writes);
Dan Williamse33129d2007-01-02 13:52:30 -07001877 } else {
1878 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
1879 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
1880
Dan Williamsd8ee0722008-06-28 08:32:06 +10001881 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
Dan Williams600aa102008-06-28 08:32:05 +10001882 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
1883 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
1884 set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07001885
1886 for (i = disks; i--; ) {
1887 struct r5dev *dev = &sh->dev[i];
1888 if (i == pd_idx)
1889 continue;
1890
Dan Williamse33129d2007-01-02 13:52:30 -07001891 if (dev->towrite &&
1892 (test_bit(R5_UPTODATE, &dev->flags) ||
Dan Williamsd8ee0722008-06-28 08:32:06 +10001893 test_bit(R5_Wantcompute, &dev->flags))) {
1894 set_bit(R5_Wantdrain, &dev->flags);
Dan Williamse33129d2007-01-02 13:52:30 -07001895 set_bit(R5_LOCKED, &dev->flags);
1896 clear_bit(R5_UPTODATE, &dev->flags);
Dan Williams600aa102008-06-28 08:32:05 +10001897 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07001898 }
1899 }
1900 }
1901
1902 /* keep the parity disk locked while asynchronous operations
1903 * are in flight
1904 */
1905 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1906 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
Dan Williams600aa102008-06-28 08:32:05 +10001907 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07001908
Dan Williams600aa102008-06-28 08:32:05 +10001909 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -07001910 __func__, (unsigned long long)sh->sector,
Dan Williams600aa102008-06-28 08:32:05 +10001911 s->locked, s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07001912}
NeilBrown16a53ec2006-06-26 00:27:38 -07001913
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914/*
1915 * Each stripe/dev can have one or more bion attached.
NeilBrown16a53ec2006-06-26 00:27:38 -07001916 * toread/towrite point to the first in a chain.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917 * The bi_next chain must be in order.
1918 */
1919static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1920{
1921 struct bio **bip;
1922 raid5_conf_t *conf = sh->raid_conf;
NeilBrown72626682005-09-09 16:23:54 -07001923 int firstwrite=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001924
Dan Williams45b42332007-07-09 11:56:43 -07001925 pr_debug("adding bh b#%llu to stripe s#%llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001926 (unsigned long long)bi->bi_sector,
1927 (unsigned long long)sh->sector);
1928
1929
1930 spin_lock(&sh->lock);
1931 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07001932 if (forwrite) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001933 bip = &sh->dev[dd_idx].towrite;
NeilBrown72626682005-09-09 16:23:54 -07001934 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1935 firstwrite = 1;
1936 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001937 bip = &sh->dev[dd_idx].toread;
1938 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1939 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1940 goto overlap;
1941 bip = & (*bip)->bi_next;
1942 }
1943 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1944 goto overlap;
1945
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001946 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947 if (*bip)
1948 bi->bi_next = *bip;
1949 *bip = bi;
Jens Axboe960e7392008-08-15 10:41:18 +02001950 bi->bi_phys_segments++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951 spin_unlock_irq(&conf->device_lock);
1952 spin_unlock(&sh->lock);
1953
Dan Williams45b42332007-07-09 11:56:43 -07001954 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001955 (unsigned long long)bi->bi_sector,
1956 (unsigned long long)sh->sector, dd_idx);
1957
NeilBrown72626682005-09-09 16:23:54 -07001958 if (conf->mddev->bitmap && firstwrite) {
NeilBrown72626682005-09-09 16:23:54 -07001959 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1960 STRIPE_SECTORS, 0);
NeilBrownae3c20c2006-07-10 04:44:17 -07001961 sh->bm_seq = conf->seq_flush+1;
NeilBrown72626682005-09-09 16:23:54 -07001962 set_bit(STRIPE_BIT_DELAY, &sh->state);
1963 }
1964
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 if (forwrite) {
1966 /* check if page is covered */
1967 sector_t sector = sh->dev[dd_idx].sector;
1968 for (bi=sh->dev[dd_idx].towrite;
1969 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1970 bi && bi->bi_sector <= sector;
1971 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1972 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1973 sector = bi->bi_sector + (bi->bi_size>>9);
1974 }
1975 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1976 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1977 }
1978 return 1;
1979
1980 overlap:
1981 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1982 spin_unlock_irq(&conf->device_lock);
1983 spin_unlock(&sh->lock);
1984 return 0;
1985}
1986
NeilBrown29269552006-03-27 01:18:10 -08001987static void end_reshape(raid5_conf_t *conf);
1988
NeilBrown16a53ec2006-06-26 00:27:38 -07001989static int page_is_zero(struct page *p)
1990{
1991 char *a = page_address(p);
1992 return ((*(u32*)a) == 0 &&
1993 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1994}
1995
NeilBrown911d4ee2009-03-31 14:39:38 +11001996static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
1997 struct stripe_head *sh)
NeilBrownccfcc3c2006-03-27 01:18:09 -08001998{
NeilBrown784052e2009-03-31 15:19:07 +11001999 int sectors_per_chunk =
2000 previous ? (conf->prev_chunk >> 9)
2001 : (conf->chunk_size >> 9);
NeilBrown911d4ee2009-03-31 14:39:38 +11002002 int dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002003 int chunk_offset = sector_div(stripe, sectors_per_chunk);
NeilBrown112bf892009-03-31 14:39:38 +11002004 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002005
NeilBrown112bf892009-03-31 14:39:38 +11002006 raid5_compute_sector(conf,
2007 stripe * (disks - conf->max_degraded)
NeilBrownb875e532006-12-10 02:20:49 -08002008 *sectors_per_chunk + chunk_offset,
NeilBrown112bf892009-03-31 14:39:38 +11002009 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11002010 &dd_idx, sh);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002011}
2012
Dan Williamsa4456852007-07-09 11:56:43 -07002013static void
Dan Williams1fe797e2008-06-28 09:16:30 +10002014handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002015 struct stripe_head_state *s, int disks,
2016 struct bio **return_bi)
2017{
2018 int i;
2019 for (i = disks; i--; ) {
2020 struct bio *bi;
2021 int bitmap_end = 0;
2022
2023 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2024 mdk_rdev_t *rdev;
2025 rcu_read_lock();
2026 rdev = rcu_dereference(conf->disks[i].rdev);
2027 if (rdev && test_bit(In_sync, &rdev->flags))
2028 /* multiple read failures in one stripe */
2029 md_error(conf->mddev, rdev);
2030 rcu_read_unlock();
2031 }
2032 spin_lock_irq(&conf->device_lock);
2033 /* fail all writes first */
2034 bi = sh->dev[i].towrite;
2035 sh->dev[i].towrite = NULL;
2036 if (bi) {
2037 s->to_write--;
2038 bitmap_end = 1;
2039 }
2040
2041 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2042 wake_up(&conf->wait_for_overlap);
2043
2044 while (bi && bi->bi_sector <
2045 sh->dev[i].sector + STRIPE_SECTORS) {
2046 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2047 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002048 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002049 md_write_end(conf->mddev);
2050 bi->bi_next = *return_bi;
2051 *return_bi = bi;
2052 }
2053 bi = nextbi;
2054 }
2055 /* and fail all 'written' */
2056 bi = sh->dev[i].written;
2057 sh->dev[i].written = NULL;
2058 if (bi) bitmap_end = 1;
2059 while (bi && bi->bi_sector <
2060 sh->dev[i].sector + STRIPE_SECTORS) {
2061 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2062 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002063 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002064 md_write_end(conf->mddev);
2065 bi->bi_next = *return_bi;
2066 *return_bi = bi;
2067 }
2068 bi = bi2;
2069 }
2070
Dan Williamsb5e98d62007-01-02 13:52:31 -07002071 /* fail any reads if this device is non-operational and
2072 * the data has not reached the cache yet.
2073 */
2074 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2075 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2076 test_bit(R5_ReadError, &sh->dev[i].flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002077 bi = sh->dev[i].toread;
2078 sh->dev[i].toread = NULL;
2079 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2080 wake_up(&conf->wait_for_overlap);
2081 if (bi) s->to_read--;
2082 while (bi && bi->bi_sector <
2083 sh->dev[i].sector + STRIPE_SECTORS) {
2084 struct bio *nextbi =
2085 r5_next_bio(bi, sh->dev[i].sector);
2086 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002087 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002088 bi->bi_next = *return_bi;
2089 *return_bi = bi;
2090 }
2091 bi = nextbi;
2092 }
2093 }
2094 spin_unlock_irq(&conf->device_lock);
2095 if (bitmap_end)
2096 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2097 STRIPE_SECTORS, 0, 0);
2098 }
2099
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002100 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2101 if (atomic_dec_and_test(&conf->pending_full_writes))
2102 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002103}
2104
Dan Williams1fe797e2008-06-28 09:16:30 +10002105/* fetch_block5 - checks the given member device to see if its data needs
2106 * to be read or computed to satisfy a request.
2107 *
2108 * Returns 1 when no more member devices need to be checked, otherwise returns
2109 * 0 to tell the loop in handle_stripe_fill5 to continue
Dan Williamsf38e1212007-01-02 13:52:30 -07002110 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002111static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2112 int disk_idx, int disks)
Dan Williamsf38e1212007-01-02 13:52:30 -07002113{
2114 struct r5dev *dev = &sh->dev[disk_idx];
2115 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2116
Dan Williamsf38e1212007-01-02 13:52:30 -07002117 /* is the data in this block needed, and can we get it? */
2118 if (!test_bit(R5_LOCKED, &dev->flags) &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002119 !test_bit(R5_UPTODATE, &dev->flags) &&
2120 (dev->toread ||
2121 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2122 s->syncing || s->expanding ||
2123 (s->failed &&
2124 (failed_dev->toread ||
2125 (failed_dev->towrite &&
2126 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002127 /* We would like to get this block, possibly by computing it,
2128 * otherwise read it if the backing disk is insync
Dan Williamsf38e1212007-01-02 13:52:30 -07002129 */
2130 if ((s->uptodate == disks - 1) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10002131 (s->failed && disk_idx == s->failed_num)) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002132 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2133 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
Dan Williamsf38e1212007-01-02 13:52:30 -07002134 set_bit(R5_Wantcompute, &dev->flags);
2135 sh->ops.target = disk_idx;
2136 s->req_compute = 1;
Dan Williamsf38e1212007-01-02 13:52:30 -07002137 /* Careful: from this point on 'uptodate' is in the eye
2138 * of raid5_run_ops which services 'compute' operations
2139 * before writes. R5_Wantcompute flags a block that will
2140 * be R5_UPTODATE by the time it is needed for a
2141 * subsequent operation.
2142 */
2143 s->uptodate++;
Dan Williams1fe797e2008-06-28 09:16:30 +10002144 return 1; /* uptodate + compute == disks */
Dan Williams7a1fc532008-07-10 04:54:57 -07002145 } else if (test_bit(R5_Insync, &dev->flags)) {
Dan Williamsf38e1212007-01-02 13:52:30 -07002146 set_bit(R5_LOCKED, &dev->flags);
2147 set_bit(R5_Wantread, &dev->flags);
Dan Williamsf38e1212007-01-02 13:52:30 -07002148 s->locked++;
2149 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2150 s->syncing);
2151 }
2152 }
2153
Dan Williams1fe797e2008-06-28 09:16:30 +10002154 return 0;
Dan Williamsf38e1212007-01-02 13:52:30 -07002155}
2156
Dan Williams1fe797e2008-06-28 09:16:30 +10002157/**
2158 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2159 */
2160static void handle_stripe_fill5(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002161 struct stripe_head_state *s, int disks)
2162{
2163 int i;
Dan Williamsf38e1212007-01-02 13:52:30 -07002164
Dan Williamsf38e1212007-01-02 13:52:30 -07002165 /* look for blocks to read/compute, skip this if a compute
2166 * is already in flight, or if the stripe contents are in the
2167 * midst of changing due to a write
2168 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002169 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002170 !sh->reconstruct_state)
Dan Williamsf38e1212007-01-02 13:52:30 -07002171 for (i = disks; i--; )
Dan Williams1fe797e2008-06-28 09:16:30 +10002172 if (fetch_block5(sh, s, i, disks))
Dan Williamsf38e1212007-01-02 13:52:30 -07002173 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002174 set_bit(STRIPE_HANDLE, &sh->state);
2175}
2176
Dan Williams1fe797e2008-06-28 09:16:30 +10002177static void handle_stripe_fill6(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002178 struct stripe_head_state *s, struct r6_state *r6s,
2179 int disks)
2180{
2181 int i;
2182 for (i = disks; i--; ) {
2183 struct r5dev *dev = &sh->dev[i];
2184 if (!test_bit(R5_LOCKED, &dev->flags) &&
2185 !test_bit(R5_UPTODATE, &dev->flags) &&
2186 (dev->toread || (dev->towrite &&
2187 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2188 s->syncing || s->expanding ||
2189 (s->failed >= 1 &&
2190 (sh->dev[r6s->failed_num[0]].toread ||
2191 s->to_write)) ||
2192 (s->failed >= 2 &&
2193 (sh->dev[r6s->failed_num[1]].toread ||
2194 s->to_write)))) {
2195 /* we would like to get this block, possibly
2196 * by computing it, but we might not be able to
2197 */
Dan Williamsc3378692008-06-05 22:45:54 -07002198 if ((s->uptodate == disks - 1) &&
2199 (s->failed && (i == r6s->failed_num[0] ||
2200 i == r6s->failed_num[1]))) {
Dan Williams45b42332007-07-09 11:56:43 -07002201 pr_debug("Computing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002202 (unsigned long long)sh->sector, i);
2203 compute_block_1(sh, i, 0);
2204 s->uptodate++;
2205 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2206 /* Computing 2-failure is *very* expensive; only
2207 * do it if failed >= 2
2208 */
2209 int other;
2210 for (other = disks; other--; ) {
2211 if (other == i)
2212 continue;
2213 if (!test_bit(R5_UPTODATE,
2214 &sh->dev[other].flags))
2215 break;
2216 }
2217 BUG_ON(other < 0);
Dan Williams45b42332007-07-09 11:56:43 -07002218 pr_debug("Computing stripe %llu blocks %d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002219 (unsigned long long)sh->sector,
2220 i, other);
2221 compute_block_2(sh, i, other);
2222 s->uptodate += 2;
2223 } else if (test_bit(R5_Insync, &dev->flags)) {
2224 set_bit(R5_LOCKED, &dev->flags);
2225 set_bit(R5_Wantread, &dev->flags);
2226 s->locked++;
Dan Williams45b42332007-07-09 11:56:43 -07002227 pr_debug("Reading block %d (sync=%d)\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002228 i, s->syncing);
2229 }
2230 }
2231 }
2232 set_bit(STRIPE_HANDLE, &sh->state);
2233}
2234
2235
Dan Williams1fe797e2008-06-28 09:16:30 +10002236/* handle_stripe_clean_event
Dan Williamsa4456852007-07-09 11:56:43 -07002237 * any written block on an uptodate or failed drive can be returned.
2238 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2239 * never LOCKED, so we don't need to test 'failed' directly.
2240 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002241static void handle_stripe_clean_event(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002242 struct stripe_head *sh, int disks, struct bio **return_bi)
2243{
2244 int i;
2245 struct r5dev *dev;
2246
2247 for (i = disks; i--; )
2248 if (sh->dev[i].written) {
2249 dev = &sh->dev[i];
2250 if (!test_bit(R5_LOCKED, &dev->flags) &&
2251 test_bit(R5_UPTODATE, &dev->flags)) {
2252 /* We can return any write requests */
2253 struct bio *wbi, *wbi2;
2254 int bitmap_end = 0;
Dan Williams45b42332007-07-09 11:56:43 -07002255 pr_debug("Return write for disc %d\n", i);
Dan Williamsa4456852007-07-09 11:56:43 -07002256 spin_lock_irq(&conf->device_lock);
2257 wbi = dev->written;
2258 dev->written = NULL;
2259 while (wbi && wbi->bi_sector <
2260 dev->sector + STRIPE_SECTORS) {
2261 wbi2 = r5_next_bio(wbi, dev->sector);
Jens Axboe960e7392008-08-15 10:41:18 +02002262 if (!raid5_dec_bi_phys_segments(wbi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002263 md_write_end(conf->mddev);
2264 wbi->bi_next = *return_bi;
2265 *return_bi = wbi;
2266 }
2267 wbi = wbi2;
2268 }
2269 if (dev->towrite == NULL)
2270 bitmap_end = 1;
2271 spin_unlock_irq(&conf->device_lock);
2272 if (bitmap_end)
2273 bitmap_endwrite(conf->mddev->bitmap,
2274 sh->sector,
2275 STRIPE_SECTORS,
2276 !test_bit(STRIPE_DEGRADED, &sh->state),
2277 0);
2278 }
2279 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002280
2281 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2282 if (atomic_dec_and_test(&conf->pending_full_writes))
2283 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002284}
2285
Dan Williams1fe797e2008-06-28 09:16:30 +10002286static void handle_stripe_dirtying5(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002287 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2288{
2289 int rmw = 0, rcw = 0, i;
2290 for (i = disks; i--; ) {
2291 /* would I have to read this buffer for read_modify_write */
2292 struct r5dev *dev = &sh->dev[i];
2293 if ((dev->towrite || i == sh->pd_idx) &&
2294 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002295 !(test_bit(R5_UPTODATE, &dev->flags) ||
2296 test_bit(R5_Wantcompute, &dev->flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002297 if (test_bit(R5_Insync, &dev->flags))
2298 rmw++;
2299 else
2300 rmw += 2*disks; /* cannot read it */
2301 }
2302 /* Would I have to read this buffer for reconstruct_write */
2303 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2304 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002305 !(test_bit(R5_UPTODATE, &dev->flags) ||
2306 test_bit(R5_Wantcompute, &dev->flags))) {
2307 if (test_bit(R5_Insync, &dev->flags)) rcw++;
Dan Williamsa4456852007-07-09 11:56:43 -07002308 else
2309 rcw += 2*disks;
2310 }
2311 }
Dan Williams45b42332007-07-09 11:56:43 -07002312 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002313 (unsigned long long)sh->sector, rmw, rcw);
2314 set_bit(STRIPE_HANDLE, &sh->state);
2315 if (rmw < rcw && rmw > 0)
2316 /* prefer read-modify-write, but need to get some data */
2317 for (i = disks; i--; ) {
2318 struct r5dev *dev = &sh->dev[i];
2319 if ((dev->towrite || i == sh->pd_idx) &&
2320 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002321 !(test_bit(R5_UPTODATE, &dev->flags) ||
2322 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002323 test_bit(R5_Insync, &dev->flags)) {
2324 if (
2325 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002326 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002327 "%d for r-m-w\n", i);
2328 set_bit(R5_LOCKED, &dev->flags);
2329 set_bit(R5_Wantread, &dev->flags);
2330 s->locked++;
2331 } else {
2332 set_bit(STRIPE_DELAYED, &sh->state);
2333 set_bit(STRIPE_HANDLE, &sh->state);
2334 }
2335 }
2336 }
2337 if (rcw <= rmw && rcw > 0)
2338 /* want reconstruct write, but need to get some data */
2339 for (i = disks; i--; ) {
2340 struct r5dev *dev = &sh->dev[i];
2341 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2342 i != sh->pd_idx &&
2343 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002344 !(test_bit(R5_UPTODATE, &dev->flags) ||
2345 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002346 test_bit(R5_Insync, &dev->flags)) {
2347 if (
2348 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002349 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002350 "%d for Reconstruct\n", i);
2351 set_bit(R5_LOCKED, &dev->flags);
2352 set_bit(R5_Wantread, &dev->flags);
2353 s->locked++;
2354 } else {
2355 set_bit(STRIPE_DELAYED, &sh->state);
2356 set_bit(STRIPE_HANDLE, &sh->state);
2357 }
2358 }
2359 }
2360 /* now if nothing is locked, and if we have enough data,
2361 * we can start a write request
2362 */
Dan Williamsf38e1212007-01-02 13:52:30 -07002363 /* since handle_stripe can be called at any time we need to handle the
2364 * case where a compute block operation has been submitted and then a
2365 * subsequent call wants to start a write request. raid5_run_ops only
2366 * handles the case where compute block and postxor are requested
2367 * simultaneously. If this is not the case then new writes need to be
2368 * held off until the compute completes.
2369 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002370 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2371 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2372 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
Dan Williams1fe797e2008-06-28 09:16:30 +10002373 schedule_reconstruction5(sh, s, rcw == 0, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002374}
2375
Dan Williams1fe797e2008-06-28 09:16:30 +10002376static void handle_stripe_dirtying6(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002377 struct stripe_head *sh, struct stripe_head_state *s,
2378 struct r6_state *r6s, int disks)
2379{
2380 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
NeilBrown34e04e82009-03-31 15:10:16 +11002381 int qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07002382 for (i = disks; i--; ) {
2383 struct r5dev *dev = &sh->dev[i];
2384 /* Would I have to read this buffer for reconstruct_write */
2385 if (!test_bit(R5_OVERWRITE, &dev->flags)
2386 && i != pd_idx && i != qd_idx
2387 && (!test_bit(R5_LOCKED, &dev->flags)
2388 ) &&
2389 !test_bit(R5_UPTODATE, &dev->flags)) {
2390 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2391 else {
Dan Williams45b42332007-07-09 11:56:43 -07002392 pr_debug("raid6: must_compute: "
Dan Williamsa4456852007-07-09 11:56:43 -07002393 "disk %d flags=%#lx\n", i, dev->flags);
2394 must_compute++;
2395 }
2396 }
2397 }
Dan Williams45b42332007-07-09 11:56:43 -07002398 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002399 (unsigned long long)sh->sector, rcw, must_compute);
2400 set_bit(STRIPE_HANDLE, &sh->state);
2401
2402 if (rcw > 0)
2403 /* want reconstruct write, but need to get some data */
2404 for (i = disks; i--; ) {
2405 struct r5dev *dev = &sh->dev[i];
2406 if (!test_bit(R5_OVERWRITE, &dev->flags)
2407 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2408 && !test_bit(R5_LOCKED, &dev->flags) &&
2409 !test_bit(R5_UPTODATE, &dev->flags) &&
2410 test_bit(R5_Insync, &dev->flags)) {
2411 if (
2412 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002413 pr_debug("Read_old stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002414 "block %d for Reconstruct\n",
2415 (unsigned long long)sh->sector, i);
2416 set_bit(R5_LOCKED, &dev->flags);
2417 set_bit(R5_Wantread, &dev->flags);
2418 s->locked++;
2419 } else {
Dan Williams45b42332007-07-09 11:56:43 -07002420 pr_debug("Request delayed stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002421 "block %d for Reconstruct\n",
2422 (unsigned long long)sh->sector, i);
2423 set_bit(STRIPE_DELAYED, &sh->state);
2424 set_bit(STRIPE_HANDLE, &sh->state);
2425 }
2426 }
2427 }
2428 /* now if nothing is locked, and if we have enough data, we can start a
2429 * write request
2430 */
2431 if (s->locked == 0 && rcw == 0 &&
2432 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2433 if (must_compute > 0) {
2434 /* We have failed blocks and need to compute them */
2435 switch (s->failed) {
2436 case 0:
2437 BUG();
2438 case 1:
2439 compute_block_1(sh, r6s->failed_num[0], 0);
2440 break;
2441 case 2:
2442 compute_block_2(sh, r6s->failed_num[0],
2443 r6s->failed_num[1]);
2444 break;
2445 default: /* This request should have been failed? */
2446 BUG();
2447 }
2448 }
2449
Dan Williams45b42332007-07-09 11:56:43 -07002450 pr_debug("Computing parity for stripe %llu\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002451 (unsigned long long)sh->sector);
2452 compute_parity6(sh, RECONSTRUCT_WRITE);
2453 /* now every locked buffer is ready to be written */
2454 for (i = disks; i--; )
2455 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
Dan Williams45b42332007-07-09 11:56:43 -07002456 pr_debug("Writing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002457 (unsigned long long)sh->sector, i);
2458 s->locked++;
2459 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2460 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002461 if (s->locked == disks)
2462 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2463 atomic_inc(&conf->pending_full_writes);
Dan Williamsa4456852007-07-09 11:56:43 -07002464 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2465 set_bit(STRIPE_INSYNC, &sh->state);
2466
2467 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2468 atomic_dec(&conf->preread_active_stripes);
2469 if (atomic_read(&conf->preread_active_stripes) <
2470 IO_THRESHOLD)
2471 md_wakeup_thread(conf->mddev->thread);
2472 }
2473 }
2474}
2475
2476static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2477 struct stripe_head_state *s, int disks)
2478{
Dan Williamsecc65c92008-06-28 08:31:57 +10002479 struct r5dev *dev = NULL;
Dan Williamse89f8962007-01-02 13:52:31 -07002480
Dan Williamsbd2ab672008-04-10 21:29:27 -07002481 set_bit(STRIPE_HANDLE, &sh->state);
2482
Dan Williamsecc65c92008-06-28 08:31:57 +10002483 switch (sh->check_state) {
2484 case check_state_idle:
2485 /* start a new check operation if there are no failures */
Dan Williamsbd2ab672008-04-10 21:29:27 -07002486 if (s->failed == 0) {
Dan Williamsbd2ab672008-04-10 21:29:27 -07002487 BUG_ON(s->uptodate != disks);
Dan Williamsecc65c92008-06-28 08:31:57 +10002488 sh->check_state = check_state_run;
2489 set_bit(STRIPE_OP_CHECK, &s->ops_request);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002490 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002491 s->uptodate--;
Dan Williamsecc65c92008-06-28 08:31:57 +10002492 break;
Dan Williamsbd2ab672008-04-10 21:29:27 -07002493 }
Dan Williamsa4456852007-07-09 11:56:43 -07002494 dev = &sh->dev[s->failed_num];
Dan Williamsecc65c92008-06-28 08:31:57 +10002495 /* fall through */
2496 case check_state_compute_result:
2497 sh->check_state = check_state_idle;
2498 if (!dev)
2499 dev = &sh->dev[sh->pd_idx];
2500
2501 /* check that a write has not made the stripe insync */
2502 if (test_bit(STRIPE_INSYNC, &sh->state))
2503 break;
2504
2505 /* either failed parity check, or recovery is happening */
Dan Williamsa4456852007-07-09 11:56:43 -07002506 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2507 BUG_ON(s->uptodate != disks);
2508
2509 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsecc65c92008-06-28 08:31:57 +10002510 s->locked++;
Dan Williamsa4456852007-07-09 11:56:43 -07002511 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002512
Dan Williamsa4456852007-07-09 11:56:43 -07002513 clear_bit(STRIPE_DEGRADED, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002514 set_bit(STRIPE_INSYNC, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002515 break;
2516 case check_state_run:
2517 break; /* we will be called again upon completion */
2518 case check_state_check_result:
2519 sh->check_state = check_state_idle;
2520
2521 /* if a failure occurred during the check operation, leave
2522 * STRIPE_INSYNC not set and let the stripe be handled again
2523 */
2524 if (s->failed)
2525 break;
2526
2527 /* handle a successful check operation, if parity is correct
2528 * we are done. Otherwise update the mismatch count and repair
2529 * parity if !MD_RECOVERY_CHECK
2530 */
2531 if (sh->ops.zero_sum_result == 0)
2532 /* parity is correct (on disc,
2533 * not in buffer any more)
2534 */
2535 set_bit(STRIPE_INSYNC, &sh->state);
2536 else {
2537 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2538 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2539 /* don't try to repair!! */
2540 set_bit(STRIPE_INSYNC, &sh->state);
2541 else {
2542 sh->check_state = check_state_compute_run;
Dan Williams976ea8d2008-06-28 08:32:03 +10002543 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002544 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2545 set_bit(R5_Wantcompute,
2546 &sh->dev[sh->pd_idx].flags);
2547 sh->ops.target = sh->pd_idx;
2548 s->uptodate++;
2549 }
2550 }
2551 break;
2552 case check_state_compute_run:
2553 break;
2554 default:
2555 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2556 __func__, sh->check_state,
2557 (unsigned long long) sh->sector);
2558 BUG();
Dan Williamsa4456852007-07-09 11:56:43 -07002559 }
2560}
2561
2562
2563static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2564 struct stripe_head_state *s,
2565 struct r6_state *r6s, struct page *tmp_page,
2566 int disks)
2567{
2568 int update_p = 0, update_q = 0;
2569 struct r5dev *dev;
2570 int pd_idx = sh->pd_idx;
NeilBrown34e04e82009-03-31 15:10:16 +11002571 int qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07002572
2573 set_bit(STRIPE_HANDLE, &sh->state);
2574
2575 BUG_ON(s->failed > 2);
2576 BUG_ON(s->uptodate < disks);
2577 /* Want to check and possibly repair P and Q.
2578 * However there could be one 'failed' device, in which
2579 * case we can only check one of them, possibly using the
2580 * other to generate missing data
2581 */
2582
2583 /* If !tmp_page, we cannot do the calculations,
2584 * but as we have set STRIPE_HANDLE, we will soon be called
2585 * by stripe_handle with a tmp_page - just wait until then.
2586 */
2587 if (tmp_page) {
2588 if (s->failed == r6s->q_failed) {
2589 /* The only possible failed device holds 'Q', so it
2590 * makes sense to check P (If anything else were failed,
2591 * we would have used P to recreate it).
2592 */
2593 compute_block_1(sh, pd_idx, 1);
2594 if (!page_is_zero(sh->dev[pd_idx].page)) {
2595 compute_block_1(sh, pd_idx, 0);
2596 update_p = 1;
2597 }
2598 }
2599 if (!r6s->q_failed && s->failed < 2) {
2600 /* q is not failed, and we didn't use it to generate
2601 * anything, so it makes sense to check it
2602 */
2603 memcpy(page_address(tmp_page),
2604 page_address(sh->dev[qd_idx].page),
2605 STRIPE_SIZE);
2606 compute_parity6(sh, UPDATE_PARITY);
2607 if (memcmp(page_address(tmp_page),
2608 page_address(sh->dev[qd_idx].page),
2609 STRIPE_SIZE) != 0) {
2610 clear_bit(STRIPE_INSYNC, &sh->state);
2611 update_q = 1;
2612 }
2613 }
2614 if (update_p || update_q) {
2615 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2616 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2617 /* don't try to repair!! */
2618 update_p = update_q = 0;
2619 }
2620
2621 /* now write out any block on a failed drive,
2622 * or P or Q if they need it
2623 */
2624
2625 if (s->failed == 2) {
2626 dev = &sh->dev[r6s->failed_num[1]];
2627 s->locked++;
2628 set_bit(R5_LOCKED, &dev->flags);
2629 set_bit(R5_Wantwrite, &dev->flags);
2630 }
2631 if (s->failed >= 1) {
2632 dev = &sh->dev[r6s->failed_num[0]];
2633 s->locked++;
2634 set_bit(R5_LOCKED, &dev->flags);
2635 set_bit(R5_Wantwrite, &dev->flags);
2636 }
2637
2638 if (update_p) {
2639 dev = &sh->dev[pd_idx];
2640 s->locked++;
2641 set_bit(R5_LOCKED, &dev->flags);
2642 set_bit(R5_Wantwrite, &dev->flags);
2643 }
2644 if (update_q) {
2645 dev = &sh->dev[qd_idx];
2646 s->locked++;
2647 set_bit(R5_LOCKED, &dev->flags);
2648 set_bit(R5_Wantwrite, &dev->flags);
2649 }
2650 clear_bit(STRIPE_DEGRADED, &sh->state);
2651
2652 set_bit(STRIPE_INSYNC, &sh->state);
2653 }
2654}
2655
2656static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2657 struct r6_state *r6s)
2658{
2659 int i;
2660
2661 /* We have read all the blocks in this stripe and now we need to
2662 * copy some of them into a target stripe for expand.
2663 */
Dan Williamsf0a50d32007-01-02 13:52:31 -07002664 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsa4456852007-07-09 11:56:43 -07002665 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2666 for (i = 0; i < sh->disks; i++)
NeilBrown34e04e82009-03-31 15:10:16 +11002667 if (i != sh->pd_idx && i != sh->qd_idx) {
NeilBrown911d4ee2009-03-31 14:39:38 +11002668 int dd_idx, j;
Dan Williamsa4456852007-07-09 11:56:43 -07002669 struct stripe_head *sh2;
2670
NeilBrown784052e2009-03-31 15:19:07 +11002671 sector_t bn = compute_blocknr(sh, i, 1);
NeilBrown911d4ee2009-03-31 14:39:38 +11002672 sector_t s = raid5_compute_sector(conf, bn, 0,
2673 &dd_idx, NULL);
NeilBrownb5663ba2009-03-31 14:39:38 +11002674 sh2 = get_active_stripe(conf, s, 0, 1);
Dan Williamsa4456852007-07-09 11:56:43 -07002675 if (sh2 == NULL)
2676 /* so far only the early blocks of this stripe
2677 * have been requested. When later blocks
2678 * get requested, we will try again
2679 */
2680 continue;
2681 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2682 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2683 /* must have already done this block */
2684 release_stripe(sh2);
2685 continue;
2686 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002687
2688 /* place all the copies on one channel */
2689 tx = async_memcpy(sh2->dev[dd_idx].page,
2690 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2691 ASYNC_TX_DEP_ACK, tx, NULL, NULL);
2692
Dan Williamsa4456852007-07-09 11:56:43 -07002693 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2694 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2695 for (j = 0; j < conf->raid_disks; j++)
2696 if (j != sh2->pd_idx &&
NeilBrownd0dabf72009-03-31 14:39:38 +11002697 (!r6s || j != sh2->qd_idx) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002698 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2699 break;
2700 if (j == conf->raid_disks) {
2701 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2702 set_bit(STRIPE_HANDLE, &sh2->state);
2703 }
2704 release_stripe(sh2);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002705
Dan Williamsa4456852007-07-09 11:56:43 -07002706 }
NeilBrowna2e08552007-09-11 15:23:36 -07002707 /* done submitting copies, wait for them to complete */
2708 if (tx) {
2709 async_tx_ack(tx);
2710 dma_wait_for_async_tx(tx);
2711 }
Dan Williamsa4456852007-07-09 11:56:43 -07002712}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002713
Dan Williams6bfe0b42008-04-30 00:52:32 -07002714
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715/*
2716 * handle_stripe - do things to a stripe.
2717 *
2718 * We lock the stripe and then examine the state of various bits
2719 * to see what needs to be done.
2720 * Possible results:
2721 * return some read request which now have data
2722 * return some write requests which are safely on disc
2723 * schedule a read on some buffers
2724 * schedule a write of some buffers
2725 * return confirmation of parity correctness
2726 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002727 * buffers are taken off read_list or write_list, and bh_cache buffers
2728 * get BH_Lock set before the stripe lock is released.
2729 *
2730 */
Dan Williamsa4456852007-07-09 11:56:43 -07002731
Dan Williamsdf10cfb2008-07-28 23:10:39 -07002732static bool handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733{
2734 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa4456852007-07-09 11:56:43 -07002735 int disks = sh->disks, i;
2736 struct bio *return_bi = NULL;
2737 struct stripe_head_state s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002738 struct r5dev *dev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002739 mdk_rdev_t *blocked_rdev = NULL;
Dan Williamse0a115e2008-06-05 22:45:52 -07002740 int prexor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741
Dan Williamsa4456852007-07-09 11:56:43 -07002742 memset(&s, 0, sizeof(s));
Dan Williams600aa102008-06-28 08:32:05 +10002743 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2744 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
2745 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
2746 sh->reconstruct_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002747
2748 spin_lock(&sh->lock);
2749 clear_bit(STRIPE_HANDLE, &sh->state);
2750 clear_bit(STRIPE_DELAYED, &sh->state);
2751
Dan Williamsa4456852007-07-09 11:56:43 -07002752 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2753 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2754 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Dan Williams83de75c2008-06-28 08:31:58 +10002755
Linus Torvalds1da177e2005-04-16 15:20:36 -07002756 /* Now to look around and see what can be done */
NeilBrown9910f162006-01-06 00:20:24 -08002757 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002758 for (i=disks; i--; ) {
2759 mdk_rdev_t *rdev;
Dan Williamsa4456852007-07-09 11:56:43 -07002760 struct r5dev *dev = &sh->dev[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002761 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002762
Dan Williamsb5e98d62007-01-02 13:52:31 -07002763 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2764 "written %p\n", i, dev->flags, dev->toread, dev->read,
2765 dev->towrite, dev->written);
2766
2767 /* maybe we can request a biofill operation
2768 *
2769 * new wantfill requests are only permitted while
Dan Williams83de75c2008-06-28 08:31:58 +10002770 * ops_complete_biofill is guaranteed to be inactive
Dan Williamsb5e98d62007-01-02 13:52:31 -07002771 */
2772 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
Dan Williams83de75c2008-06-28 08:31:58 +10002773 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
Dan Williamsb5e98d62007-01-02 13:52:31 -07002774 set_bit(R5_Wantfill, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002775
2776 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002777 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2778 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williamsf38e1212007-01-02 13:52:30 -07002779 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002780
Dan Williamsb5e98d62007-01-02 13:52:31 -07002781 if (test_bit(R5_Wantfill, &dev->flags))
2782 s.to_fill++;
2783 else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07002784 s.to_read++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002785 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002786 s.to_write++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002787 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002788 s.non_overwrite++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002789 }
Dan Williamsa4456852007-07-09 11:56:43 -07002790 if (dev->written)
2791 s.written++;
NeilBrown9910f162006-01-06 00:20:24 -08002792 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10002793 if (blocked_rdev == NULL &&
2794 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07002795 blocked_rdev = rdev;
2796 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07002797 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002798 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08002799 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08002800 clear_bit(R5_ReadError, &dev->flags);
2801 clear_bit(R5_ReWrite, &dev->flags);
2802 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002803 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002804 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002805 s.failed++;
2806 s.failed_num = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002807 } else
2808 set_bit(R5_Insync, &dev->flags);
2809 }
NeilBrown9910f162006-01-06 00:20:24 -08002810 rcu_read_unlock();
Dan Williamsb5e98d62007-01-02 13:52:31 -07002811
Dan Williams6bfe0b42008-04-30 00:52:32 -07002812 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10002813 if (s.syncing || s.expanding || s.expanded ||
2814 s.to_write || s.written) {
2815 set_bit(STRIPE_HANDLE, &sh->state);
2816 goto unlock;
2817 }
2818 /* There is nothing for the blocked_rdev to block */
2819 rdev_dec_pending(blocked_rdev, conf->mddev);
2820 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002821 }
2822
Dan Williams83de75c2008-06-28 08:31:58 +10002823 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
2824 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
2825 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
2826 }
Dan Williamsb5e98d62007-01-02 13:52:31 -07002827
Dan Williams45b42332007-07-09 11:56:43 -07002828 pr_debug("locked=%d uptodate=%d to_read=%d"
Linus Torvalds1da177e2005-04-16 15:20:36 -07002829 " to_write=%d failed=%d failed_num=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002830 s.locked, s.uptodate, s.to_read, s.to_write,
2831 s.failed, s.failed_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002832 /* check if the array has lost two devices and, if so, some requests might
2833 * need to be failed
2834 */
Dan Williamsa4456852007-07-09 11:56:43 -07002835 if (s.failed > 1 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10002836 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07002837 if (s.failed > 1 && s.syncing) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002838 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2839 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002840 s.syncing = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002841 }
2842
2843 /* might be able to return some write requests if the parity block
2844 * is safe, or on a failed drive
2845 */
2846 dev = &sh->dev[sh->pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07002847 if ( s.written &&
2848 ((test_bit(R5_Insync, &dev->flags) &&
2849 !test_bit(R5_LOCKED, &dev->flags) &&
2850 test_bit(R5_UPTODATE, &dev->flags)) ||
2851 (s.failed == 1 && s.failed_num == sh->pd_idx)))
Dan Williams1fe797e2008-06-28 09:16:30 +10002852 handle_stripe_clean_event(conf, sh, disks, &return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002853
2854 /* Now we might consider reading some blocks, either to check/generate
2855 * parity, or to satisfy requests
2856 * or to load a block that is being partially written.
2857 */
Dan Williamsa4456852007-07-09 11:56:43 -07002858 if (s.to_read || s.non_overwrite ||
Dan Williams976ea8d2008-06-28 08:32:03 +10002859 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10002860 handle_stripe_fill5(sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002861
Dan Williamse33129d2007-01-02 13:52:30 -07002862 /* Now we check to see if any write operations have recently
2863 * completed
2864 */
Dan Williamse0a115e2008-06-05 22:45:52 -07002865 prexor = 0;
Dan Williamsd8ee0722008-06-28 08:32:06 +10002866 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
Dan Williamse0a115e2008-06-05 22:45:52 -07002867 prexor = 1;
Dan Williamsd8ee0722008-06-28 08:32:06 +10002868 if (sh->reconstruct_state == reconstruct_state_drain_result ||
2869 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
Dan Williams600aa102008-06-28 08:32:05 +10002870 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamse33129d2007-01-02 13:52:30 -07002871
2872 /* All the 'written' buffers and the parity block are ready to
2873 * be written back to disk
2874 */
2875 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
2876 for (i = disks; i--; ) {
2877 dev = &sh->dev[i];
2878 if (test_bit(R5_LOCKED, &dev->flags) &&
2879 (i == sh->pd_idx || dev->written)) {
2880 pr_debug("Writing block %d\n", i);
2881 set_bit(R5_Wantwrite, &dev->flags);
Dan Williamse0a115e2008-06-05 22:45:52 -07002882 if (prexor)
2883 continue;
Dan Williamse33129d2007-01-02 13:52:30 -07002884 if (!test_bit(R5_Insync, &dev->flags) ||
2885 (i == sh->pd_idx && s.failed == 0))
2886 set_bit(STRIPE_INSYNC, &sh->state);
2887 }
2888 }
2889 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2890 atomic_dec(&conf->preread_active_stripes);
2891 if (atomic_read(&conf->preread_active_stripes) <
2892 IO_THRESHOLD)
2893 md_wakeup_thread(conf->mddev->thread);
2894 }
2895 }
2896
2897 /* Now to consider new write requests and what else, if anything
2898 * should be read. We do not handle new writes when:
2899 * 1/ A 'write' operation (copy+xor) is already in flight.
2900 * 2/ A 'check' operation is in flight, as it may clobber the parity
2901 * block.
2902 */
Dan Williams600aa102008-06-28 08:32:05 +10002903 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
Dan Williams1fe797e2008-06-28 09:16:30 +10002904 handle_stripe_dirtying5(conf, sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002905
2906 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamse89f8962007-01-02 13:52:31 -07002907 * Any reads will already have been scheduled, so we just see if enough
2908 * data is available. The parity check is held off while parity
2909 * dependent operations are in flight.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002910 */
Dan Williamsecc65c92008-06-28 08:31:57 +10002911 if (sh->check_state ||
2912 (s.syncing && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10002913 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10002914 !test_bit(STRIPE_INSYNC, &sh->state)))
Dan Williamsa4456852007-07-09 11:56:43 -07002915 handle_parity_checks5(conf, sh, &s, disks);
Dan Williamse89f8962007-01-02 13:52:31 -07002916
Dan Williamsa4456852007-07-09 11:56:43 -07002917 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002918 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2919 clear_bit(STRIPE_SYNCING, &sh->state);
2920 }
NeilBrown4e5314b2005-11-08 21:39:22 -08002921
2922 /* If the failed drive is just a ReadError, then we might need to progress
2923 * the repair/check process
2924 */
Dan Williamsa4456852007-07-09 11:56:43 -07002925 if (s.failed == 1 && !conf->mddev->ro &&
2926 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2927 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2928 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002929 ) {
Dan Williamsa4456852007-07-09 11:56:43 -07002930 dev = &sh->dev[s.failed_num];
NeilBrown4e5314b2005-11-08 21:39:22 -08002931 if (!test_bit(R5_ReWrite, &dev->flags)) {
2932 set_bit(R5_Wantwrite, &dev->flags);
2933 set_bit(R5_ReWrite, &dev->flags);
2934 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002935 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002936 } else {
2937 /* let's read it back */
2938 set_bit(R5_Wantread, &dev->flags);
2939 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002940 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002941 }
2942 }
2943
Dan Williams600aa102008-06-28 08:32:05 +10002944 /* Finish reconstruct operations initiated by the expansion process */
2945 if (sh->reconstruct_state == reconstruct_state_result) {
NeilBrownab69ae12009-03-31 15:26:47 +11002946 struct stripe_head *sh2
2947 = get_active_stripe(conf, sh->sector, 1, 1);
2948 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
2949 /* sh cannot be written until sh2 has been read.
2950 * so arrange for sh to be delayed a little
2951 */
2952 set_bit(STRIPE_DELAYED, &sh->state);
2953 set_bit(STRIPE_HANDLE, &sh->state);
2954 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
2955 &sh2->state))
2956 atomic_inc(&conf->preread_active_stripes);
2957 release_stripe(sh2);
2958 goto unlock;
2959 }
2960 if (sh2)
2961 release_stripe(sh2);
2962
Dan Williams600aa102008-06-28 08:32:05 +10002963 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamsf0a50d32007-01-02 13:52:31 -07002964 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williams23397882008-07-23 20:05:34 -07002965 for (i = conf->raid_disks; i--; ) {
Dan Williamsf0a50d32007-01-02 13:52:31 -07002966 set_bit(R5_Wantwrite, &sh->dev[i].flags);
Dan Williams23397882008-07-23 20:05:34 -07002967 set_bit(R5_LOCKED, &sh->dev[i].flags);
Neil Brownefe31142008-06-28 08:31:14 +10002968 s.locked++;
Dan Williams23397882008-07-23 20:05:34 -07002969 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002970 }
2971
2972 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
Dan Williams600aa102008-06-28 08:32:05 +10002973 !sh->reconstruct_state) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002974 /* Need to write out all blocks after computing parity */
2975 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11002976 stripe_set_idx(sh->sector, conf, 0, sh);
Dan Williams1fe797e2008-06-28 09:16:30 +10002977 schedule_reconstruction5(sh, &s, 1, 1);
Dan Williams600aa102008-06-28 08:32:05 +10002978 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002979 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08002980 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002981 wake_up(&conf->wait_for_overlap);
2982 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2983 }
2984
Dan Williams0f94e872008-01-08 15:32:53 -08002985 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10002986 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07002987 handle_stripe_expansion(conf, sh, NULL);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002988
Dan Williams6bfe0b42008-04-30 00:52:32 -07002989 unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002990 spin_unlock(&sh->lock);
2991
Dan Williams6bfe0b42008-04-30 00:52:32 -07002992 /* wait for this device to become unblocked */
2993 if (unlikely(blocked_rdev))
2994 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
2995
Dan Williams600aa102008-06-28 08:32:05 +10002996 if (s.ops_request)
2997 raid5_run_ops(sh, s.ops_request);
Dan Williamsd84e0f12007-01-02 13:52:30 -07002998
Dan Williamsc4e5ac02008-06-28 08:31:53 +10002999 ops_run_io(sh, &s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003000
Dan Williamsa4456852007-07-09 11:56:43 -07003001 return_io(return_bi);
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003002
3003 return blocked_rdev == NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003004}
3005
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003006static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
NeilBrown16a53ec2006-06-26 00:27:38 -07003007{
NeilBrownbff61972009-03-31 14:33:13 +11003008 raid5_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08003009 int disks = sh->disks;
Dan Williamsa4456852007-07-09 11:56:43 -07003010 struct bio *return_bi = NULL;
NeilBrown34e04e82009-03-31 15:10:16 +11003011 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07003012 struct stripe_head_state s;
3013 struct r6_state r6s;
NeilBrown16a53ec2006-06-26 00:27:38 -07003014 struct r5dev *dev, *pdev, *qdev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003015 mdk_rdev_t *blocked_rdev = NULL;
NeilBrown16a53ec2006-06-26 00:27:38 -07003016
Dan Williams45b42332007-07-09 11:56:43 -07003017 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
Dan Williamsa4456852007-07-09 11:56:43 -07003018 "pd_idx=%d, qd_idx=%d\n",
3019 (unsigned long long)sh->sector, sh->state,
NeilBrown34e04e82009-03-31 15:10:16 +11003020 atomic_read(&sh->count), pd_idx, qd_idx);
Dan Williamsa4456852007-07-09 11:56:43 -07003021 memset(&s, 0, sizeof(s));
NeilBrown16a53ec2006-06-26 00:27:38 -07003022
3023 spin_lock(&sh->lock);
3024 clear_bit(STRIPE_HANDLE, &sh->state);
3025 clear_bit(STRIPE_DELAYED, &sh->state);
3026
Dan Williamsa4456852007-07-09 11:56:43 -07003027 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3028 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3029 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrown16a53ec2006-06-26 00:27:38 -07003030 /* Now to look around and see what can be done */
3031
3032 rcu_read_lock();
3033 for (i=disks; i--; ) {
3034 mdk_rdev_t *rdev;
3035 dev = &sh->dev[i];
3036 clear_bit(R5_Insync, &dev->flags);
3037
Dan Williams45b42332007-07-09 11:56:43 -07003038 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003039 i, dev->flags, dev->toread, dev->towrite, dev->written);
3040 /* maybe we can reply to a read */
3041 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
3042 struct bio *rbi, *rbi2;
Dan Williams45b42332007-07-09 11:56:43 -07003043 pr_debug("Return read for disc %d\n", i);
NeilBrown16a53ec2006-06-26 00:27:38 -07003044 spin_lock_irq(&conf->device_lock);
3045 rbi = dev->toread;
3046 dev->toread = NULL;
3047 if (test_and_clear_bit(R5_Overlap, &dev->flags))
3048 wake_up(&conf->wait_for_overlap);
3049 spin_unlock_irq(&conf->device_lock);
3050 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
3051 copy_data(0, rbi, dev->page, dev->sector);
3052 rbi2 = r5_next_bio(rbi, dev->sector);
3053 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02003054 if (!raid5_dec_bi_phys_segments(rbi)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003055 rbi->bi_next = return_bi;
3056 return_bi = rbi;
3057 }
3058 spin_unlock_irq(&conf->device_lock);
3059 rbi = rbi2;
3060 }
3061 }
3062
3063 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07003064 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3065 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003066
3067
Dan Williamsa4456852007-07-09 11:56:43 -07003068 if (dev->toread)
3069 s.to_read++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003070 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07003071 s.to_write++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003072 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07003073 s.non_overwrite++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003074 }
Dan Williamsa4456852007-07-09 11:56:43 -07003075 if (dev->written)
3076 s.written++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003077 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10003078 if (blocked_rdev == NULL &&
3079 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07003080 blocked_rdev = rdev;
3081 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07003082 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003083 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
3084 /* The ReadError flag will just be confusing now */
3085 clear_bit(R5_ReadError, &dev->flags);
3086 clear_bit(R5_ReWrite, &dev->flags);
3087 }
3088 if (!rdev || !test_bit(In_sync, &rdev->flags)
3089 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07003090 if (s.failed < 2)
3091 r6s.failed_num[s.failed] = i;
3092 s.failed++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003093 } else
3094 set_bit(R5_Insync, &dev->flags);
3095 }
3096 rcu_read_unlock();
Dan Williams6bfe0b42008-04-30 00:52:32 -07003097
3098 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10003099 if (s.syncing || s.expanding || s.expanded ||
3100 s.to_write || s.written) {
3101 set_bit(STRIPE_HANDLE, &sh->state);
3102 goto unlock;
3103 }
3104 /* There is nothing for the blocked_rdev to block */
3105 rdev_dec_pending(blocked_rdev, conf->mddev);
3106 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003107 }
NeilBrownac4090d2008-08-05 15:54:13 +10003108
Dan Williams45b42332007-07-09 11:56:43 -07003109 pr_debug("locked=%d uptodate=%d to_read=%d"
NeilBrown16a53ec2006-06-26 00:27:38 -07003110 " to_write=%d failed=%d failed_num=%d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003111 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3112 r6s.failed_num[0], r6s.failed_num[1]);
3113 /* check if the array has lost >2 devices and, if so, some requests
3114 * might need to be failed
NeilBrown16a53ec2006-06-26 00:27:38 -07003115 */
Dan Williamsa4456852007-07-09 11:56:43 -07003116 if (s.failed > 2 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10003117 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07003118 if (s.failed > 2 && s.syncing) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003119 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3120 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003121 s.syncing = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07003122 }
3123
3124 /*
3125 * might be able to return some write requests if the parity blocks
3126 * are safe, or on a failed drive
3127 */
3128 pdev = &sh->dev[pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07003129 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3130 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
NeilBrown34e04e82009-03-31 15:10:16 +11003131 qdev = &sh->dev[qd_idx];
3132 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3133 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
NeilBrown16a53ec2006-06-26 00:27:38 -07003134
Dan Williamsa4456852007-07-09 11:56:43 -07003135 if ( s.written &&
3136 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003137 && !test_bit(R5_LOCKED, &pdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003138 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3139 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003140 && !test_bit(R5_LOCKED, &qdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003141 && test_bit(R5_UPTODATE, &qdev->flags)))))
Dan Williams1fe797e2008-06-28 09:16:30 +10003142 handle_stripe_clean_event(conf, sh, disks, &return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003143
3144 /* Now we might consider reading some blocks, either to check/generate
3145 * parity, or to satisfy requests
3146 * or to load a block that is being partially written.
3147 */
Dan Williamsa4456852007-07-09 11:56:43 -07003148 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3149 (s.syncing && (s.uptodate < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10003150 handle_stripe_fill6(sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003151
3152 /* now to consider writing and what else, if anything should be read */
Dan Williamsa4456852007-07-09 11:56:43 -07003153 if (s.to_write)
Dan Williams1fe797e2008-06-28 09:16:30 +10003154 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003155
3156 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamsa4456852007-07-09 11:56:43 -07003157 * Any reads will already have been scheduled, so we just see if enough
3158 * data is available
NeilBrown16a53ec2006-06-26 00:27:38 -07003159 */
Dan Williamsa4456852007-07-09 11:56:43 -07003160 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
3161 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003162
Dan Williamsa4456852007-07-09 11:56:43 -07003163 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003164 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3165 clear_bit(STRIPE_SYNCING, &sh->state);
3166 }
3167
3168 /* If the failed drives are just a ReadError, then we might need
3169 * to progress the repair/check process
3170 */
Dan Williamsa4456852007-07-09 11:56:43 -07003171 if (s.failed <= 2 && !conf->mddev->ro)
3172 for (i = 0; i < s.failed; i++) {
3173 dev = &sh->dev[r6s.failed_num[i]];
NeilBrown16a53ec2006-06-26 00:27:38 -07003174 if (test_bit(R5_ReadError, &dev->flags)
3175 && !test_bit(R5_LOCKED, &dev->flags)
3176 && test_bit(R5_UPTODATE, &dev->flags)
3177 ) {
3178 if (!test_bit(R5_ReWrite, &dev->flags)) {
3179 set_bit(R5_Wantwrite, &dev->flags);
3180 set_bit(R5_ReWrite, &dev->flags);
3181 set_bit(R5_LOCKED, &dev->flags);
3182 } else {
3183 /* let's read it back */
3184 set_bit(R5_Wantread, &dev->flags);
3185 set_bit(R5_LOCKED, &dev->flags);
3186 }
3187 }
3188 }
NeilBrownf4168852007-02-28 20:11:53 -08003189
Dan Williamsa4456852007-07-09 11:56:43 -07003190 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
NeilBrownab69ae12009-03-31 15:26:47 +11003191 struct stripe_head *sh2
3192 = get_active_stripe(conf, sh->sector, 1, 1);
3193 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3194 /* sh cannot be written until sh2 has been read.
3195 * so arrange for sh to be delayed a little
3196 */
3197 set_bit(STRIPE_DELAYED, &sh->state);
3198 set_bit(STRIPE_HANDLE, &sh->state);
3199 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3200 &sh2->state))
3201 atomic_inc(&conf->preread_active_stripes);
3202 release_stripe(sh2);
3203 goto unlock;
3204 }
3205 if (sh2)
3206 release_stripe(sh2);
3207
NeilBrownf4168852007-02-28 20:11:53 -08003208 /* Need to write out all blocks after computing P&Q */
3209 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11003210 stripe_set_idx(sh->sector, conf, 0, sh);
NeilBrownf4168852007-02-28 20:11:53 -08003211 compute_parity6(sh, RECONSTRUCT_WRITE);
3212 for (i = conf->raid_disks ; i-- ; ) {
3213 set_bit(R5_LOCKED, &sh->dev[i].flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003214 s.locked++;
NeilBrownf4168852007-02-28 20:11:53 -08003215 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3216 }
3217 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003218 } else if (s.expanded) {
NeilBrownf4168852007-02-28 20:11:53 -08003219 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3220 atomic_dec(&conf->reshape_stripes);
3221 wake_up(&conf->wait_for_overlap);
3222 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3223 }
3224
Dan Williams0f94e872008-01-08 15:32:53 -08003225 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10003226 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07003227 handle_stripe_expansion(conf, sh, &r6s);
NeilBrownf4168852007-02-28 20:11:53 -08003228
Dan Williams6bfe0b42008-04-30 00:52:32 -07003229 unlock:
NeilBrown16a53ec2006-06-26 00:27:38 -07003230 spin_unlock(&sh->lock);
3231
Dan Williams6bfe0b42008-04-30 00:52:32 -07003232 /* wait for this device to become unblocked */
3233 if (unlikely(blocked_rdev))
3234 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3235
Dan Williamsf0e43bc2008-06-28 08:31:55 +10003236 ops_run_io(sh, &s);
3237
Dan Williamsa4456852007-07-09 11:56:43 -07003238 return_io(return_bi);
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003239
3240 return blocked_rdev == NULL;
NeilBrown16a53ec2006-06-26 00:27:38 -07003241}
3242
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003243/* returns true if the stripe was handled */
3244static bool handle_stripe(struct stripe_head *sh, struct page *tmp_page)
NeilBrown16a53ec2006-06-26 00:27:38 -07003245{
3246 if (sh->raid_conf->level == 6)
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003247 return handle_stripe6(sh, tmp_page);
NeilBrown16a53ec2006-06-26 00:27:38 -07003248 else
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003249 return handle_stripe5(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -07003250}
3251
3252
3253
Arjan van de Ven858119e2006-01-14 13:20:43 -08003254static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003255{
3256 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3257 while (!list_empty(&conf->delayed_list)) {
3258 struct list_head *l = conf->delayed_list.next;
3259 struct stripe_head *sh;
3260 sh = list_entry(l, struct stripe_head, lru);
3261 list_del_init(l);
3262 clear_bit(STRIPE_DELAYED, &sh->state);
3263 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3264 atomic_inc(&conf->preread_active_stripes);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003265 list_add_tail(&sh->lru, &conf->hold_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003266 }
NeilBrown6ed30032008-02-06 01:40:00 -08003267 } else
3268 blk_plug_device(conf->mddev->queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003269}
3270
Arjan van de Ven858119e2006-01-14 13:20:43 -08003271static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07003272{
3273 /* device_lock is held */
3274 struct list_head head;
3275 list_add(&head, &conf->bitmap_list);
3276 list_del_init(&conf->bitmap_list);
3277 while (!list_empty(&head)) {
3278 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3279 list_del_init(&sh->lru);
3280 atomic_inc(&sh->count);
3281 __release_stripe(conf, sh);
3282 }
3283}
3284
Linus Torvalds1da177e2005-04-16 15:20:36 -07003285static void unplug_slaves(mddev_t *mddev)
3286{
3287 raid5_conf_t *conf = mddev_to_conf(mddev);
3288 int i;
3289
3290 rcu_read_lock();
3291 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08003292 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08003293 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +02003294 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003295
3296 atomic_inc(&rdev->nr_pending);
3297 rcu_read_unlock();
3298
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -05003299 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003300
3301 rdev_dec_pending(rdev, mddev);
3302 rcu_read_lock();
3303 }
3304 }
3305 rcu_read_unlock();
3306}
3307
Jens Axboe165125e2007-07-24 09:28:11 +02003308static void raid5_unplug_device(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003309{
3310 mddev_t *mddev = q->queuedata;
3311 raid5_conf_t *conf = mddev_to_conf(mddev);
3312 unsigned long flags;
3313
3314 spin_lock_irqsave(&conf->device_lock, flags);
3315
NeilBrown72626682005-09-09 16:23:54 -07003316 if (blk_remove_plug(q)) {
3317 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003318 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07003319 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003320 md_wakeup_thread(mddev->thread);
3321
3322 spin_unlock_irqrestore(&conf->device_lock, flags);
3323
3324 unplug_slaves(mddev);
3325}
3326
NeilBrownf022b2f2006-10-03 01:15:56 -07003327static int raid5_congested(void *data, int bits)
3328{
3329 mddev_t *mddev = data;
3330 raid5_conf_t *conf = mddev_to_conf(mddev);
3331
3332 /* No difference between reads and writes. Just check
3333 * how busy the stripe_cache is
3334 */
3335 if (conf->inactive_blocked)
3336 return 1;
3337 if (conf->quiesce)
3338 return 1;
3339 if (list_empty_careful(&conf->inactive_list))
3340 return 1;
3341
3342 return 0;
3343}
3344
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003345/* We want read requests to align with chunks where possible,
3346 * but write requests don't need to.
3347 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003348static int raid5_mergeable_bvec(struct request_queue *q,
3349 struct bvec_merge_data *bvm,
3350 struct bio_vec *biovec)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003351{
3352 mddev_t *mddev = q->queuedata;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003353 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003354 int max;
3355 unsigned int chunk_sectors = mddev->chunk_size >> 9;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003356 unsigned int bio_sectors = bvm->bi_size >> 9;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003357
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003358 if ((bvm->bi_rw & 1) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003359 return biovec->bv_len; /* always allow writes to be mergeable */
3360
NeilBrown784052e2009-03-31 15:19:07 +11003361 if (mddev->new_chunk < mddev->chunk_size)
3362 chunk_sectors = mddev->new_chunk >> 9;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003363 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3364 if (max < 0) max = 0;
3365 if (max <= biovec->bv_len && bio_sectors == 0)
3366 return biovec->bv_len;
3367 else
3368 return max;
3369}
3370
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003371
3372static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3373{
3374 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3375 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3376 unsigned int bio_sectors = bio->bi_size >> 9;
3377
NeilBrown784052e2009-03-31 15:19:07 +11003378 if (mddev->new_chunk < mddev->chunk_size)
3379 chunk_sectors = mddev->new_chunk >> 9;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003380 return chunk_sectors >=
3381 ((sector & (chunk_sectors - 1)) + bio_sectors);
3382}
3383
3384/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003385 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3386 * later sampled by raid5d.
3387 */
3388static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3389{
3390 unsigned long flags;
3391
3392 spin_lock_irqsave(&conf->device_lock, flags);
3393
3394 bi->bi_next = conf->retry_read_aligned_list;
3395 conf->retry_read_aligned_list = bi;
3396
3397 spin_unlock_irqrestore(&conf->device_lock, flags);
3398 md_wakeup_thread(conf->mddev->thread);
3399}
3400
3401
3402static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3403{
3404 struct bio *bi;
3405
3406 bi = conf->retry_read_aligned;
3407 if (bi) {
3408 conf->retry_read_aligned = NULL;
3409 return bi;
3410 }
3411 bi = conf->retry_read_aligned_list;
3412 if(bi) {
Neil Brown387bb172007-02-08 14:20:29 -08003413 conf->retry_read_aligned_list = bi->bi_next;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003414 bi->bi_next = NULL;
Jens Axboe960e7392008-08-15 10:41:18 +02003415 /*
3416 * this sets the active strip count to 1 and the processed
3417 * strip count to zero (upper 8 bits)
3418 */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003419 bi->bi_phys_segments = 1; /* biased count of active stripes */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003420 }
3421
3422 return bi;
3423}
3424
3425
3426/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003427 * The "raid5_align_endio" should check if the read succeeded and if it
3428 * did, call bio_endio on the original bio (having bio_put the new bio
3429 * first).
3430 * If the read failed..
3431 */
NeilBrown6712ecf2007-09-27 12:47:43 +02003432static void raid5_align_endio(struct bio *bi, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003433{
3434 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003435 mddev_t *mddev;
3436 raid5_conf_t *conf;
3437 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3438 mdk_rdev_t *rdev;
3439
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003440 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003441
3442 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
3443 conf = mddev_to_conf(mddev);
3444 rdev = (void*)raid_bi->bi_next;
3445 raid_bi->bi_next = NULL;
3446
3447 rdev_dec_pending(rdev, conf->mddev);
3448
3449 if (!error && uptodate) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003450 bio_endio(raid_bi, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003451 if (atomic_dec_and_test(&conf->active_aligned_reads))
3452 wake_up(&conf->wait_for_stripe);
NeilBrown6712ecf2007-09-27 12:47:43 +02003453 return;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003454 }
3455
3456
Dan Williams45b42332007-07-09 11:56:43 -07003457 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003458
3459 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003460}
3461
Neil Brown387bb172007-02-08 14:20:29 -08003462static int bio_fits_rdev(struct bio *bi)
3463{
Jens Axboe165125e2007-07-24 09:28:11 +02003464 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
Neil Brown387bb172007-02-08 14:20:29 -08003465
3466 if ((bi->bi_size>>9) > q->max_sectors)
3467 return 0;
3468 blk_recount_segments(q, bi);
Jens Axboe960e7392008-08-15 10:41:18 +02003469 if (bi->bi_phys_segments > q->max_phys_segments)
Neil Brown387bb172007-02-08 14:20:29 -08003470 return 0;
3471
3472 if (q->merge_bvec_fn)
3473 /* it's too hard to apply the merge_bvec_fn at this stage,
3474 * just just give up
3475 */
3476 return 0;
3477
3478 return 1;
3479}
3480
3481
Jens Axboe165125e2007-07-24 09:28:11 +02003482static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003483{
3484 mddev_t *mddev = q->queuedata;
3485 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown911d4ee2009-03-31 14:39:38 +11003486 unsigned int dd_idx;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003487 struct bio* align_bi;
3488 mdk_rdev_t *rdev;
3489
3490 if (!in_chunk_boundary(mddev, raid_bio)) {
Dan Williams45b42332007-07-09 11:56:43 -07003491 pr_debug("chunk_aligned_read : non aligned\n");
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003492 return 0;
3493 }
3494 /*
NeilBrown99c0fb52009-03-31 14:39:38 +11003495 * use bio_clone to make a copy of the bio
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003496 */
3497 align_bi = bio_clone(raid_bio, GFP_NOIO);
3498 if (!align_bi)
3499 return 0;
3500 /*
3501 * set bi_end_io to a new function, and set bi_private to the
3502 * original bio.
3503 */
3504 align_bi->bi_end_io = raid5_align_endio;
3505 align_bi->bi_private = raid_bio;
3506 /*
3507 * compute position
3508 */
NeilBrown112bf892009-03-31 14:39:38 +11003509 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3510 0,
NeilBrown911d4ee2009-03-31 14:39:38 +11003511 &dd_idx, NULL);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003512
3513 rcu_read_lock();
3514 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3515 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003516 atomic_inc(&rdev->nr_pending);
3517 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003518 raid_bio->bi_next = (void*)rdev;
3519 align_bi->bi_bdev = rdev->bdev;
3520 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3521 align_bi->bi_sector += rdev->data_offset;
3522
Neil Brown387bb172007-02-08 14:20:29 -08003523 if (!bio_fits_rdev(align_bi)) {
3524 /* too big in some way */
3525 bio_put(align_bi);
3526 rdev_dec_pending(rdev, mddev);
3527 return 0;
3528 }
3529
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003530 spin_lock_irq(&conf->device_lock);
3531 wait_event_lock_irq(conf->wait_for_stripe,
3532 conf->quiesce == 0,
3533 conf->device_lock, /* nothing */);
3534 atomic_inc(&conf->active_aligned_reads);
3535 spin_unlock_irq(&conf->device_lock);
3536
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003537 generic_make_request(align_bi);
3538 return 1;
3539 } else {
3540 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003541 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003542 return 0;
3543 }
3544}
3545
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003546/* __get_priority_stripe - get the next stripe to process
3547 *
3548 * Full stripe writes are allowed to pass preread active stripes up until
3549 * the bypass_threshold is exceeded. In general the bypass_count
3550 * increments when the handle_list is handled before the hold_list; however, it
3551 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3552 * stripe with in flight i/o. The bypass_count will be reset when the
3553 * head of the hold_list has changed, i.e. the head was promoted to the
3554 * handle_list.
3555 */
3556static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3557{
3558 struct stripe_head *sh;
3559
3560 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3561 __func__,
3562 list_empty(&conf->handle_list) ? "empty" : "busy",
3563 list_empty(&conf->hold_list) ? "empty" : "busy",
3564 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3565
3566 if (!list_empty(&conf->handle_list)) {
3567 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3568
3569 if (list_empty(&conf->hold_list))
3570 conf->bypass_count = 0;
3571 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3572 if (conf->hold_list.next == conf->last_hold)
3573 conf->bypass_count++;
3574 else {
3575 conf->last_hold = conf->hold_list.next;
3576 conf->bypass_count -= conf->bypass_threshold;
3577 if (conf->bypass_count < 0)
3578 conf->bypass_count = 0;
3579 }
3580 }
3581 } else if (!list_empty(&conf->hold_list) &&
3582 ((conf->bypass_threshold &&
3583 conf->bypass_count > conf->bypass_threshold) ||
3584 atomic_read(&conf->pending_full_writes) == 0)) {
3585 sh = list_entry(conf->hold_list.next,
3586 typeof(*sh), lru);
3587 conf->bypass_count -= conf->bypass_threshold;
3588 if (conf->bypass_count < 0)
3589 conf->bypass_count = 0;
3590 } else
3591 return NULL;
3592
3593 list_del_init(&sh->lru);
3594 atomic_inc(&sh->count);
3595 BUG_ON(atomic_read(&sh->count) != 1);
3596 return sh;
3597}
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003598
Jens Axboe165125e2007-07-24 09:28:11 +02003599static int make_request(struct request_queue *q, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003600{
3601 mddev_t *mddev = q->queuedata;
3602 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown911d4ee2009-03-31 14:39:38 +11003603 int dd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003604 sector_t new_sector;
3605 sector_t logical_sector, last_sector;
3606 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01003607 const int rw = bio_data_dir(bi);
Tejun Heoc9959052008-08-25 19:47:21 +09003608 int cpu, remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003609
NeilBrowne5dcdd82005-09-09 16:23:41 -07003610 if (unlikely(bio_barrier(bi))) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003611 bio_endio(bi, -EOPNOTSUPP);
NeilBrowne5dcdd82005-09-09 16:23:41 -07003612 return 0;
3613 }
3614
NeilBrown3d310eb2005-06-21 17:17:26 -07003615 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07003616
Tejun Heo074a7ac2008-08-25 19:56:14 +09003617 cpu = part_stat_lock();
3618 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
3619 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
3620 bio_sectors(bi));
3621 part_stat_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003622
NeilBrown802ba062006-12-13 00:34:13 -08003623 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003624 mddev->reshape_position == MaxSector &&
3625 chunk_aligned_read(q,bi))
NeilBrown99c0fb52009-03-31 14:39:38 +11003626 return 0;
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003627
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3629 last_sector = bi->bi_sector + (bi->bi_size>>9);
3630 bi->bi_next = NULL;
3631 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07003632
Linus Torvalds1da177e2005-04-16 15:20:36 -07003633 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3634 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07003635 int disks, data_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003636 int previous;
NeilBrownb578d552006-03-27 01:18:12 -08003637
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003638 retry:
NeilBrownb5663ba2009-03-31 14:39:38 +11003639 previous = 0;
NeilBrownb0f9ec02009-03-31 15:27:18 +11003640 disks = conf->raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003641 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003642 if (unlikely(conf->reshape_progress != MaxSector)) {
NeilBrownfef9c612009-03-31 15:16:46 +11003643 /* spinlock is needed as reshape_progress may be
NeilBrowndf8e7f72006-03-27 01:18:15 -08003644 * 64bit on a 32bit platform, and so it might be
3645 * possible to see a half-updated value
NeilBrownfef9c612009-03-31 15:16:46 +11003646 * Ofcourse reshape_progress could change after
NeilBrowndf8e7f72006-03-27 01:18:15 -08003647 * the lock is dropped, so once we get a reference
3648 * to the stripe that we think it is, we will have
3649 * to check again.
3650 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003651 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003652 if (mddev->delta_disks < 0
3653 ? logical_sector < conf->reshape_progress
3654 : logical_sector >= conf->reshape_progress) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003655 disks = conf->previous_raid_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003656 previous = 1;
3657 } else {
NeilBrownfef9c612009-03-31 15:16:46 +11003658 if (mddev->delta_disks < 0
3659 ? logical_sector < conf->reshape_safe
3660 : logical_sector >= conf->reshape_safe) {
NeilBrownb578d552006-03-27 01:18:12 -08003661 spin_unlock_irq(&conf->device_lock);
3662 schedule();
3663 goto retry;
3664 }
3665 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003666 spin_unlock_irq(&conf->device_lock);
3667 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003668 data_disks = disks - conf->max_degraded;
3669
NeilBrown112bf892009-03-31 14:39:38 +11003670 new_sector = raid5_compute_sector(conf, logical_sector,
3671 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11003672 &dd_idx, NULL);
Dan Williams45b42332007-07-09 11:56:43 -07003673 pr_debug("raid5: make_request, sector %llu logical %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07003674 (unsigned long long)new_sector,
3675 (unsigned long long)logical_sector);
3676
NeilBrownb5663ba2009-03-31 14:39:38 +11003677 sh = get_active_stripe(conf, new_sector, previous,
3678 (bi->bi_rw&RWA_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003679 if (sh) {
NeilBrownb0f9ec02009-03-31 15:27:18 +11003680 if (unlikely(previous)) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003681 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08003682 * stripe, so we must do the range check again.
3683 * Expansion could still move past after this
3684 * test, but as we are holding a reference to
3685 * 'sh', we know that if that happens,
3686 * STRIPE_EXPANDING will get set and the expansion
3687 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003688 */
3689 int must_retry = 0;
3690 spin_lock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003691 if (mddev->delta_disks < 0
3692 ? logical_sector >= conf->reshape_progress
3693 : logical_sector < conf->reshape_progress)
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003694 /* mismatch, need to try again */
3695 must_retry = 1;
3696 spin_unlock_irq(&conf->device_lock);
3697 if (must_retry) {
3698 release_stripe(sh);
3699 goto retry;
3700 }
3701 }
NeilBrowne464eaf2006-03-27 01:18:14 -08003702 /* FIXME what if we get a false positive because these
3703 * are being updated.
3704 */
3705 if (logical_sector >= mddev->suspend_lo &&
3706 logical_sector < mddev->suspend_hi) {
3707 release_stripe(sh);
3708 schedule();
3709 goto retry;
3710 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003711
3712 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3713 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3714 /* Stripe is busy expanding or
3715 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07003716 * and wait a while
3717 */
3718 raid5_unplug_device(mddev->queue);
3719 release_stripe(sh);
3720 schedule();
3721 goto retry;
3722 }
3723 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown6ed30032008-02-06 01:40:00 -08003724 set_bit(STRIPE_HANDLE, &sh->state);
3725 clear_bit(STRIPE_DELAYED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003726 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003727 } else {
3728 /* cannot get stripe for read-ahead, just give-up */
3729 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3730 finish_wait(&conf->wait_for_overlap, &w);
3731 break;
3732 }
3733
3734 }
3735 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02003736 remaining = raid5_dec_bi_phys_segments(bi);
NeilBrownf6344752006-03-27 01:18:17 -08003737 spin_unlock_irq(&conf->device_lock);
3738 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003739
NeilBrown16a53ec2006-06-26 00:27:38 -07003740 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07003741 md_write_end(mddev);
NeilBrown6712ecf2007-09-27 12:47:43 +02003742
Neil Brown0e13fe232008-06-28 08:31:20 +10003743 bio_endio(bi, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003744 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003745 return 0;
3746}
3747
Dan Williamsb522adc2009-03-31 15:00:31 +11003748static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
3749
NeilBrown52c03292006-06-26 00:27:43 -07003750static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003751{
NeilBrown52c03292006-06-26 00:27:43 -07003752 /* reshaping is quite different to recovery/resync so it is
3753 * handled quite separately ... here.
3754 *
3755 * On each call to sync_request, we gather one chunk worth of
3756 * destination stripes and flag them as expanding.
3757 * Then we find all the source stripes and request reads.
3758 * As the reads complete, handle_stripe will copy the data
3759 * into the destination stripe and release that stripe.
3760 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003761 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3762 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08003763 sector_t first_sector, last_sector;
NeilBrownf4168852007-02-28 20:11:53 -08003764 int raid_disks = conf->previous_raid_disks;
3765 int data_disks = raid_disks - conf->max_degraded;
3766 int new_data_disks = conf->raid_disks - conf->max_degraded;
NeilBrown52c03292006-06-26 00:27:43 -07003767 int i;
3768 int dd_idx;
NeilBrownc8f517c2009-03-31 15:28:40 +11003769 sector_t writepos, readpos, safepos;
NeilBrownec32a2b2009-03-31 15:17:38 +11003770 sector_t stripe_addr;
NeilBrown7a661382009-03-31 15:21:40 +11003771 int reshape_sectors;
NeilBrownab69ae12009-03-31 15:26:47 +11003772 struct list_head stripes;
NeilBrown52c03292006-06-26 00:27:43 -07003773
NeilBrownfef9c612009-03-31 15:16:46 +11003774 if (sector_nr == 0) {
3775 /* If restarting in the middle, skip the initial sectors */
3776 if (mddev->delta_disks < 0 &&
3777 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
3778 sector_nr = raid5_size(mddev, 0, 0)
3779 - conf->reshape_progress;
3780 } else if (mddev->delta_disks > 0 &&
3781 conf->reshape_progress > 0)
3782 sector_nr = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003783 sector_div(sector_nr, new_data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003784 if (sector_nr) {
3785 *skipped = 1;
3786 return sector_nr;
3787 }
NeilBrown52c03292006-06-26 00:27:43 -07003788 }
3789
NeilBrown7a661382009-03-31 15:21:40 +11003790 /* We need to process a full chunk at a time.
3791 * If old and new chunk sizes differ, we need to process the
3792 * largest of these
3793 */
3794 if (mddev->new_chunk > mddev->chunk_size)
3795 reshape_sectors = mddev->new_chunk / 512;
3796 else
3797 reshape_sectors = mddev->chunk_size / 512;
3798
NeilBrown52c03292006-06-26 00:27:43 -07003799 /* we update the metadata when there is more than 3Meg
3800 * in the block range (that is rather arbitrary, should
3801 * probably be time based) or when the data about to be
3802 * copied would over-write the source of the data at
3803 * the front of the range.
NeilBrownfef9c612009-03-31 15:16:46 +11003804 * i.e. one new_stripe along from reshape_progress new_maps
3805 * to after where reshape_safe old_maps to
NeilBrown52c03292006-06-26 00:27:43 -07003806 */
NeilBrownfef9c612009-03-31 15:16:46 +11003807 writepos = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003808 sector_div(writepos, new_data_disks);
NeilBrownc8f517c2009-03-31 15:28:40 +11003809 readpos = conf->reshape_progress;
3810 sector_div(readpos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003811 safepos = conf->reshape_safe;
NeilBrownf4168852007-02-28 20:11:53 -08003812 sector_div(safepos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003813 if (mddev->delta_disks < 0) {
NeilBrown7a661382009-03-31 15:21:40 +11003814 writepos -= reshape_sectors;
NeilBrownc8f517c2009-03-31 15:28:40 +11003815 readpos += reshape_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11003816 safepos += reshape_sectors;
NeilBrownfef9c612009-03-31 15:16:46 +11003817 } else {
NeilBrown7a661382009-03-31 15:21:40 +11003818 writepos += reshape_sectors;
NeilBrownc8f517c2009-03-31 15:28:40 +11003819 readpos -= reshape_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11003820 safepos -= reshape_sectors;
NeilBrownfef9c612009-03-31 15:16:46 +11003821 }
NeilBrown52c03292006-06-26 00:27:43 -07003822
NeilBrownc8f517c2009-03-31 15:28:40 +11003823 /* 'writepos' is the most advanced device address we might write.
3824 * 'readpos' is the least advanced device address we might read.
3825 * 'safepos' is the least address recorded in the metadata as having
3826 * been reshaped.
3827 * If 'readpos' is behind 'writepos', then there is no way that we can
3828 * ensure safety in the face of a crash - that must be done by userspace
3829 * making a backup of the data. So in that case there is no particular
3830 * rush to update metadata.
3831 * Otherwise if 'safepos' is behind 'writepos', then we really need to
3832 * update the metadata to advance 'safepos' to match 'readpos' so that
3833 * we can be safe in the event of a crash.
3834 * So we insist on updating metadata if safepos is behind writepos and
3835 * readpos is beyond writepos.
3836 * In any case, update the metadata every 10 seconds.
3837 * Maybe that number should be configurable, but I'm not sure it is
3838 * worth it.... maybe it could be a multiple of safemode_delay???
3839 */
NeilBrownfef9c612009-03-31 15:16:46 +11003840 if ((mddev->delta_disks < 0
NeilBrownc8f517c2009-03-31 15:28:40 +11003841 ? (safepos > writepos && readpos < writepos)
3842 : (safepos < writepos && readpos > writepos)) ||
3843 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
NeilBrown52c03292006-06-26 00:27:43 -07003844 /* Cannot proceed until we've updated the superblock... */
3845 wait_event(conf->wait_for_overlap,
3846 atomic_read(&conf->reshape_stripes)==0);
NeilBrownfef9c612009-03-31 15:16:46 +11003847 mddev->reshape_position = conf->reshape_progress;
NeilBrownacb180b2009-04-14 16:28:34 +10003848 mddev->curr_resync_completed = mddev->curr_resync;
NeilBrownc8f517c2009-03-31 15:28:40 +11003849 conf->reshape_checkpoint = jiffies;
NeilBrown850b2b42006-10-03 01:15:46 -07003850 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07003851 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07003852 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07003853 kthread_should_stop());
3854 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003855 conf->reshape_safe = mddev->reshape_position;
NeilBrown52c03292006-06-26 00:27:43 -07003856 spin_unlock_irq(&conf->device_lock);
3857 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10003858 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrown52c03292006-06-26 00:27:43 -07003859 }
3860
NeilBrownec32a2b2009-03-31 15:17:38 +11003861 if (mddev->delta_disks < 0) {
3862 BUG_ON(conf->reshape_progress == 0);
3863 stripe_addr = writepos;
3864 BUG_ON((mddev->dev_sectors &
NeilBrown7a661382009-03-31 15:21:40 +11003865 ~((sector_t)reshape_sectors - 1))
3866 - reshape_sectors - stripe_addr
NeilBrownec32a2b2009-03-31 15:17:38 +11003867 != sector_nr);
3868 } else {
NeilBrown7a661382009-03-31 15:21:40 +11003869 BUG_ON(writepos != sector_nr + reshape_sectors);
NeilBrownec32a2b2009-03-31 15:17:38 +11003870 stripe_addr = sector_nr;
3871 }
NeilBrownab69ae12009-03-31 15:26:47 +11003872 INIT_LIST_HEAD(&stripes);
NeilBrown7a661382009-03-31 15:21:40 +11003873 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
NeilBrown52c03292006-06-26 00:27:43 -07003874 int j;
3875 int skipped = 0;
NeilBrownec32a2b2009-03-31 15:17:38 +11003876 sh = get_active_stripe(conf, stripe_addr+i, 0, 0);
NeilBrown52c03292006-06-26 00:27:43 -07003877 set_bit(STRIPE_EXPANDING, &sh->state);
3878 atomic_inc(&conf->reshape_stripes);
3879 /* If any of this stripe is beyond the end of the old
3880 * array, then we need to zero those blocks
3881 */
3882 for (j=sh->disks; j--;) {
3883 sector_t s;
3884 if (j == sh->pd_idx)
3885 continue;
NeilBrownf4168852007-02-28 20:11:53 -08003886 if (conf->level == 6 &&
NeilBrownd0dabf72009-03-31 14:39:38 +11003887 j == sh->qd_idx)
NeilBrownf4168852007-02-28 20:11:53 -08003888 continue;
NeilBrown784052e2009-03-31 15:19:07 +11003889 s = compute_blocknr(sh, j, 0);
Dan Williamsb522adc2009-03-31 15:00:31 +11003890 if (s < raid5_size(mddev, 0, 0)) {
NeilBrown52c03292006-06-26 00:27:43 -07003891 skipped = 1;
3892 continue;
3893 }
3894 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3895 set_bit(R5_Expanded, &sh->dev[j].flags);
3896 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3897 }
3898 if (!skipped) {
3899 set_bit(STRIPE_EXPAND_READY, &sh->state);
3900 set_bit(STRIPE_HANDLE, &sh->state);
3901 }
NeilBrownab69ae12009-03-31 15:26:47 +11003902 list_add(&sh->lru, &stripes);
NeilBrown52c03292006-06-26 00:27:43 -07003903 }
3904 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003905 if (mddev->delta_disks < 0)
NeilBrown7a661382009-03-31 15:21:40 +11003906 conf->reshape_progress -= reshape_sectors * new_data_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11003907 else
NeilBrown7a661382009-03-31 15:21:40 +11003908 conf->reshape_progress += reshape_sectors * new_data_disks;
NeilBrown52c03292006-06-26 00:27:43 -07003909 spin_unlock_irq(&conf->device_lock);
3910 /* Ok, those stripe are ready. We can start scheduling
3911 * reads on the source stripes.
3912 * The source stripes are determined by mapping the first and last
3913 * block on the destination stripes.
3914 */
NeilBrown52c03292006-06-26 00:27:43 -07003915 first_sector =
NeilBrownec32a2b2009-03-31 15:17:38 +11003916 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
NeilBrown911d4ee2009-03-31 14:39:38 +11003917 1, &dd_idx, NULL);
NeilBrown52c03292006-06-26 00:27:43 -07003918 last_sector =
NeilBrownec32a2b2009-03-31 15:17:38 +11003919 raid5_compute_sector(conf, ((stripe_addr+conf->chunk_size/512)
NeilBrown112bf892009-03-31 14:39:38 +11003920 *(new_data_disks) - 1),
NeilBrown911d4ee2009-03-31 14:39:38 +11003921 1, &dd_idx, NULL);
Andre Noll58c0fed2009-03-31 14:33:13 +11003922 if (last_sector >= mddev->dev_sectors)
3923 last_sector = mddev->dev_sectors - 1;
NeilBrown52c03292006-06-26 00:27:43 -07003924 while (first_sector <= last_sector) {
NeilBrownb5663ba2009-03-31 14:39:38 +11003925 sh = get_active_stripe(conf, first_sector, 1, 0);
NeilBrown52c03292006-06-26 00:27:43 -07003926 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3927 set_bit(STRIPE_HANDLE, &sh->state);
3928 release_stripe(sh);
3929 first_sector += STRIPE_SECTORS;
3930 }
NeilBrownab69ae12009-03-31 15:26:47 +11003931 /* Now that the sources are clearly marked, we can release
3932 * the destination stripes
3933 */
3934 while (!list_empty(&stripes)) {
3935 sh = list_entry(stripes.next, struct stripe_head, lru);
3936 list_del_init(&sh->lru);
3937 release_stripe(sh);
3938 }
NeilBrownc6207272008-02-06 01:39:52 -08003939 /* If this takes us to the resync_max point where we have to pause,
3940 * then we need to write out the superblock.
3941 */
NeilBrown7a661382009-03-31 15:21:40 +11003942 sector_nr += reshape_sectors;
NeilBrownc03f6a12009-04-17 11:06:30 +10003943 if ((sector_nr - mddev->curr_resync_completed) * 2
3944 >= mddev->resync_max - mddev->curr_resync_completed) {
NeilBrownc6207272008-02-06 01:39:52 -08003945 /* Cannot proceed until we've updated the superblock... */
3946 wait_event(conf->wait_for_overlap,
3947 atomic_read(&conf->reshape_stripes) == 0);
NeilBrownfef9c612009-03-31 15:16:46 +11003948 mddev->reshape_position = conf->reshape_progress;
NeilBrownacb180b2009-04-14 16:28:34 +10003949 mddev->curr_resync_completed = mddev->curr_resync;
NeilBrownc8f517c2009-03-31 15:28:40 +11003950 conf->reshape_checkpoint = jiffies;
NeilBrownc6207272008-02-06 01:39:52 -08003951 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3952 md_wakeup_thread(mddev->thread);
3953 wait_event(mddev->sb_wait,
3954 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3955 || kthread_should_stop());
3956 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003957 conf->reshape_safe = mddev->reshape_position;
NeilBrownc6207272008-02-06 01:39:52 -08003958 spin_unlock_irq(&conf->device_lock);
3959 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10003960 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrownc6207272008-02-06 01:39:52 -08003961 }
NeilBrown7a661382009-03-31 15:21:40 +11003962 return reshape_sectors;
NeilBrown52c03292006-06-26 00:27:43 -07003963}
3964
3965/* FIXME go_faster isn't used */
3966static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3967{
3968 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3969 struct stripe_head *sh;
Andre Noll58c0fed2009-03-31 14:33:13 +11003970 sector_t max_sector = mddev->dev_sectors;
NeilBrown72626682005-09-09 16:23:54 -07003971 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07003972 int still_degraded = 0;
3973 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003974
NeilBrown72626682005-09-09 16:23:54 -07003975 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003976 /* just being told to finish up .. nothing much to do */
3977 unplug_slaves(mddev);
NeilBrowncea9c222009-03-31 15:15:05 +11003978
NeilBrown29269552006-03-27 01:18:10 -08003979 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3980 end_reshape(conf);
3981 return 0;
3982 }
NeilBrown72626682005-09-09 16:23:54 -07003983
3984 if (mddev->curr_resync < max_sector) /* aborted */
3985 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3986 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003987 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07003988 conf->fullsync = 0;
3989 bitmap_close_sync(mddev->bitmap);
3990
Linus Torvalds1da177e2005-04-16 15:20:36 -07003991 return 0;
3992 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08003993
NeilBrown52c03292006-06-26 00:27:43 -07003994 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3995 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08003996
NeilBrownc6207272008-02-06 01:39:52 -08003997 /* No need to check resync_max as we never do more than one
3998 * stripe, and as resync_max will always be on a chunk boundary,
3999 * if the check in md_do_sync didn't fire, there is no chance
4000 * of overstepping resync_max here
4001 */
4002
NeilBrown16a53ec2006-06-26 00:27:38 -07004003 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07004004 * to resync, then assert that we are finished, because there is
4005 * nothing we can do.
4006 */
NeilBrown3285edf2006-06-26 00:27:55 -07004007 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07004008 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
Andre Noll58c0fed2009-03-31 14:33:13 +11004009 sector_t rv = mddev->dev_sectors - sector_nr;
NeilBrown57afd892005-06-21 17:17:13 -07004010 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004011 return rv;
4012 }
NeilBrown72626682005-09-09 16:23:54 -07004013 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08004014 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07004015 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4016 /* we can skip this block, and probably more */
4017 sync_blocks /= STRIPE_SECTORS;
4018 *skipped = 1;
4019 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4020 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004021
NeilBrownb47490c2008-02-06 01:39:50 -08004022
4023 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4024
NeilBrownb5663ba2009-03-31 14:39:38 +11004025 sh = get_active_stripe(conf, sector_nr, 0, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004026 if (sh == NULL) {
NeilBrownb5663ba2009-03-31 14:39:38 +11004027 sh = get_active_stripe(conf, sector_nr, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004028 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07004029 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07004030 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08004031 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004032 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004033 /* Need to check if array will still be degraded after recovery/resync
4034 * We don't need to check the 'failed' flag as when that gets set,
4035 * recovery aborts.
4036 */
4037 for (i=0; i<mddev->raid_disks; i++)
4038 if (conf->disks[i].rdev == NULL)
4039 still_degraded = 1;
4040
4041 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4042
4043 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004044 set_bit(STRIPE_SYNCING, &sh->state);
4045 clear_bit(STRIPE_INSYNC, &sh->state);
4046 spin_unlock(&sh->lock);
4047
Dan Williamsdf10cfb2008-07-28 23:10:39 -07004048 /* wait for any blocked device to be handled */
4049 while(unlikely(!handle_stripe(sh, NULL)))
4050 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004051 release_stripe(sh);
4052
4053 return STRIPE_SECTORS;
4054}
4055
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004056static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4057{
4058 /* We may not be able to submit a whole bio at once as there
4059 * may not be enough stripe_heads available.
4060 * We cannot pre-allocate enough stripe_heads as we may need
4061 * more than exist in the cache (if we allow ever large chunks).
4062 * So we do one stripe head at a time and record in
4063 * ->bi_hw_segments how many have been done.
4064 *
4065 * We *know* that this entire raid_bio is in one chunk, so
4066 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4067 */
4068 struct stripe_head *sh;
NeilBrown911d4ee2009-03-31 14:39:38 +11004069 int dd_idx;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004070 sector_t sector, logical_sector, last_sector;
4071 int scnt = 0;
4072 int remaining;
4073 int handled = 0;
4074
4075 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
NeilBrown112bf892009-03-31 14:39:38 +11004076 sector = raid5_compute_sector(conf, logical_sector,
NeilBrown911d4ee2009-03-31 14:39:38 +11004077 0, &dd_idx, NULL);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004078 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4079
4080 for (; logical_sector < last_sector;
Neil Brown387bb172007-02-08 14:20:29 -08004081 logical_sector += STRIPE_SECTORS,
4082 sector += STRIPE_SECTORS,
4083 scnt++) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004084
Jens Axboe960e7392008-08-15 10:41:18 +02004085 if (scnt < raid5_bi_hw_segments(raid_bio))
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004086 /* already done this stripe */
4087 continue;
4088
NeilBrownb5663ba2009-03-31 14:39:38 +11004089 sh = get_active_stripe(conf, sector, 0, 1);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004090
4091 if (!sh) {
4092 /* failed to get a stripe - must wait */
Jens Axboe960e7392008-08-15 10:41:18 +02004093 raid5_set_bi_hw_segments(raid_bio, scnt);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004094 conf->retry_read_aligned = raid_bio;
4095 return handled;
4096 }
4097
4098 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
Neil Brown387bb172007-02-08 14:20:29 -08004099 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4100 release_stripe(sh);
Jens Axboe960e7392008-08-15 10:41:18 +02004101 raid5_set_bi_hw_segments(raid_bio, scnt);
Neil Brown387bb172007-02-08 14:20:29 -08004102 conf->retry_read_aligned = raid_bio;
4103 return handled;
4104 }
4105
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004106 handle_stripe(sh, NULL);
4107 release_stripe(sh);
4108 handled++;
4109 }
4110 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02004111 remaining = raid5_dec_bi_phys_segments(raid_bio);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004112 spin_unlock_irq(&conf->device_lock);
Neil Brown0e13fe232008-06-28 08:31:20 +10004113 if (remaining == 0)
4114 bio_endio(raid_bio, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004115 if (atomic_dec_and_test(&conf->active_aligned_reads))
4116 wake_up(&conf->wait_for_stripe);
4117 return handled;
4118}
4119
4120
4121
Linus Torvalds1da177e2005-04-16 15:20:36 -07004122/*
4123 * This is our raid5 kernel thread.
4124 *
4125 * We scan the hash table for stripes which can be handled now.
4126 * During the scan, completed stripes are saved for us by the interrupt
4127 * handler, so that they will not have to wait for our next wakeup.
4128 */
NeilBrown6ed30032008-02-06 01:40:00 -08004129static void raid5d(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004130{
4131 struct stripe_head *sh;
4132 raid5_conf_t *conf = mddev_to_conf(mddev);
4133 int handled;
4134
Dan Williams45b42332007-07-09 11:56:43 -07004135 pr_debug("+++ raid5d active\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004136
4137 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004138
4139 handled = 0;
4140 spin_lock_irq(&conf->device_lock);
4141 while (1) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004142 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004143
NeilBrownae3c20c2006-07-10 04:44:17 -07004144 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07004145 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08004146 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004147 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08004148 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004149 conf->seq_write = seq;
4150 activate_bit_delay(conf);
4151 }
4152
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004153 while ((bio = remove_bio_from_retry(conf))) {
4154 int ok;
4155 spin_unlock_irq(&conf->device_lock);
4156 ok = retry_aligned_read(conf, bio);
4157 spin_lock_irq(&conf->device_lock);
4158 if (!ok)
4159 break;
4160 handled++;
4161 }
4162
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004163 sh = __get_priority_stripe(conf);
4164
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004165 if (!sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004166 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004167 spin_unlock_irq(&conf->device_lock);
4168
4169 handled++;
NeilBrown16a53ec2006-06-26 00:27:38 -07004170 handle_stripe(sh, conf->spare_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004171 release_stripe(sh);
4172
4173 spin_lock_irq(&conf->device_lock);
4174 }
Dan Williams45b42332007-07-09 11:56:43 -07004175 pr_debug("%d stripes handled\n", handled);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004176
4177 spin_unlock_irq(&conf->device_lock);
4178
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004179 async_tx_issue_pending_all();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004180 unplug_slaves(mddev);
4181
Dan Williams45b42332007-07-09 11:56:43 -07004182 pr_debug("--- raid5d inactive\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004183}
4184
NeilBrown3f294f42005-11-08 21:39:25 -08004185static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004186raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004187{
NeilBrown007583c2005-11-08 21:39:30 -08004188 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08004189 if (conf)
4190 return sprintf(page, "%d\n", conf->max_nr_stripes);
4191 else
4192 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004193}
4194
4195static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004196raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08004197{
NeilBrown007583c2005-11-08 21:39:30 -08004198 raid5_conf_t *conf = mddev_to_conf(mddev);
Dan Williams4ef197d82008-04-28 02:15:54 -07004199 unsigned long new;
Dan Williamsb5470dc2008-06-27 21:44:04 -07004200 int err;
4201
NeilBrown3f294f42005-11-08 21:39:25 -08004202 if (len >= PAGE_SIZE)
4203 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08004204 if (!conf)
4205 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08004206
Dan Williams4ef197d82008-04-28 02:15:54 -07004207 if (strict_strtoul(page, 10, &new))
NeilBrown3f294f42005-11-08 21:39:25 -08004208 return -EINVAL;
4209 if (new <= 16 || new > 32768)
4210 return -EINVAL;
4211 while (new < conf->max_nr_stripes) {
4212 if (drop_one_stripe(conf))
4213 conf->max_nr_stripes--;
4214 else
4215 break;
4216 }
Dan Williamsb5470dc2008-06-27 21:44:04 -07004217 err = md_allow_write(mddev);
4218 if (err)
4219 return err;
NeilBrown3f294f42005-11-08 21:39:25 -08004220 while (new > conf->max_nr_stripes) {
4221 if (grow_one_stripe(conf))
4222 conf->max_nr_stripes++;
4223 else break;
4224 }
4225 return len;
4226}
NeilBrown007583c2005-11-08 21:39:30 -08004227
NeilBrown96de1e62005-11-08 21:39:39 -08004228static struct md_sysfs_entry
4229raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4230 raid5_show_stripe_cache_size,
4231 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08004232
4233static ssize_t
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004234raid5_show_preread_threshold(mddev_t *mddev, char *page)
4235{
4236 raid5_conf_t *conf = mddev_to_conf(mddev);
4237 if (conf)
4238 return sprintf(page, "%d\n", conf->bypass_threshold);
4239 else
4240 return 0;
4241}
4242
4243static ssize_t
4244raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4245{
4246 raid5_conf_t *conf = mddev_to_conf(mddev);
Dan Williams4ef197d82008-04-28 02:15:54 -07004247 unsigned long new;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004248 if (len >= PAGE_SIZE)
4249 return -EINVAL;
4250 if (!conf)
4251 return -ENODEV;
4252
Dan Williams4ef197d82008-04-28 02:15:54 -07004253 if (strict_strtoul(page, 10, &new))
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004254 return -EINVAL;
Dan Williams4ef197d82008-04-28 02:15:54 -07004255 if (new > conf->max_nr_stripes)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004256 return -EINVAL;
4257 conf->bypass_threshold = new;
4258 return len;
4259}
4260
4261static struct md_sysfs_entry
4262raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4263 S_IRUGO | S_IWUSR,
4264 raid5_show_preread_threshold,
4265 raid5_store_preread_threshold);
4266
4267static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08004268stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004269{
NeilBrown007583c2005-11-08 21:39:30 -08004270 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08004271 if (conf)
4272 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4273 else
4274 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004275}
4276
NeilBrown96de1e62005-11-08 21:39:39 -08004277static struct md_sysfs_entry
4278raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08004279
NeilBrown007583c2005-11-08 21:39:30 -08004280static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08004281 &raid5_stripecache_size.attr,
4282 &raid5_stripecache_active.attr,
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004283 &raid5_preread_bypass_threshold.attr,
NeilBrown3f294f42005-11-08 21:39:25 -08004284 NULL,
4285};
NeilBrown007583c2005-11-08 21:39:30 -08004286static struct attribute_group raid5_attrs_group = {
4287 .name = NULL,
4288 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08004289};
4290
Dan Williams80c3a6c2009-03-17 18:10:40 -07004291static sector_t
4292raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4293{
4294 raid5_conf_t *conf = mddev_to_conf(mddev);
4295
4296 if (!sectors)
4297 sectors = mddev->dev_sectors;
NeilBrown7ec05472009-03-31 15:10:36 +11004298 if (!raid_disks) {
4299 /* size is defined by the smallest of previous and new size */
4300 if (conf->raid_disks < conf->previous_raid_disks)
4301 raid_disks = conf->raid_disks;
4302 else
4303 raid_disks = conf->previous_raid_disks;
4304 }
Dan Williams80c3a6c2009-03-17 18:10:40 -07004305
4306 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
NeilBrown784052e2009-03-31 15:19:07 +11004307 sectors &= ~((sector_t)mddev->new_chunk/512 - 1);
Dan Williams80c3a6c2009-03-17 18:10:40 -07004308 return sectors * (raid_disks - conf->max_degraded);
4309}
4310
NeilBrown91adb562009-03-31 14:39:39 +11004311static raid5_conf_t *setup_conf(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004312{
4313 raid5_conf_t *conf;
4314 int raid_disk, memory;
4315 mdk_rdev_t *rdev;
4316 struct disk_info *disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004317
NeilBrown91adb562009-03-31 14:39:39 +11004318 if (mddev->new_level != 5
4319 && mddev->new_level != 4
4320 && mddev->new_level != 6) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004321 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
NeilBrown91adb562009-03-31 14:39:39 +11004322 mdname(mddev), mddev->new_level);
4323 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004324 }
NeilBrown91adb562009-03-31 14:39:39 +11004325 if ((mddev->new_level == 5
4326 && !algorithm_valid_raid5(mddev->new_layout)) ||
4327 (mddev->new_level == 6
4328 && !algorithm_valid_raid6(mddev->new_layout))) {
NeilBrown99c0fb52009-03-31 14:39:38 +11004329 printk(KERN_ERR "raid5: %s: layout %d not supported\n",
NeilBrown91adb562009-03-31 14:39:39 +11004330 mdname(mddev), mddev->new_layout);
4331 return ERR_PTR(-EIO);
4332 }
4333 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
4334 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4335 mdname(mddev), mddev->raid_disks);
4336 return ERR_PTR(-EINVAL);
NeilBrown99c0fb52009-03-31 14:39:38 +11004337 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004338
NeilBrown91adb562009-03-31 14:39:39 +11004339 if (!mddev->new_chunk || mddev->new_chunk % PAGE_SIZE) {
4340 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
4341 mddev->new_chunk, mdname(mddev));
4342 return ERR_PTR(-EINVAL);
NeilBrown4bbf3772008-10-13 11:55:12 +11004343 }
4344
NeilBrown91adb562009-03-31 14:39:39 +11004345 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4346 if (conf == NULL)
4347 goto abort;
4348
4349 conf->raid_disks = mddev->raid_disks;
4350 if (mddev->reshape_position == MaxSector)
4351 conf->previous_raid_disks = mddev->raid_disks;
4352 else
4353 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4354
4355 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
4356 GFP_KERNEL);
4357 if (!conf->disks)
4358 goto abort;
4359
4360 conf->mddev = mddev;
4361
4362 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4363 goto abort;
4364
4365 if (mddev->new_level == 6) {
4366 conf->spare_page = alloc_page(GFP_KERNEL);
4367 if (!conf->spare_page)
4368 goto abort;
4369 }
4370 spin_lock_init(&conf->device_lock);
4371 init_waitqueue_head(&conf->wait_for_stripe);
4372 init_waitqueue_head(&conf->wait_for_overlap);
4373 INIT_LIST_HEAD(&conf->handle_list);
4374 INIT_LIST_HEAD(&conf->hold_list);
4375 INIT_LIST_HEAD(&conf->delayed_list);
4376 INIT_LIST_HEAD(&conf->bitmap_list);
4377 INIT_LIST_HEAD(&conf->inactive_list);
4378 atomic_set(&conf->active_stripes, 0);
4379 atomic_set(&conf->preread_active_stripes, 0);
4380 atomic_set(&conf->active_aligned_reads, 0);
4381 conf->bypass_threshold = BYPASS_THRESHOLD;
4382
4383 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
4384
4385 list_for_each_entry(rdev, &mddev->disks, same_set) {
4386 raid_disk = rdev->raid_disk;
4387 if (raid_disk >= conf->raid_disks
4388 || raid_disk < 0)
4389 continue;
4390 disk = conf->disks + raid_disk;
4391
4392 disk->rdev = rdev;
4393
4394 if (test_bit(In_sync, &rdev->flags)) {
4395 char b[BDEVNAME_SIZE];
4396 printk(KERN_INFO "raid5: device %s operational as raid"
4397 " disk %d\n", bdevname(rdev->bdev,b),
4398 raid_disk);
4399 } else
4400 /* Cannot rely on bitmap to complete recovery */
4401 conf->fullsync = 1;
4402 }
4403
4404 conf->chunk_size = mddev->new_chunk;
4405 conf->level = mddev->new_level;
4406 if (conf->level == 6)
4407 conf->max_degraded = 2;
4408 else
4409 conf->max_degraded = 1;
4410 conf->algorithm = mddev->new_layout;
4411 conf->max_nr_stripes = NR_STRIPES;
NeilBrownfef9c612009-03-31 15:16:46 +11004412 conf->reshape_progress = mddev->reshape_position;
NeilBrowne183eae2009-03-31 15:20:22 +11004413 if (conf->reshape_progress != MaxSector) {
NeilBrown784052e2009-03-31 15:19:07 +11004414 conf->prev_chunk = mddev->chunk_size;
NeilBrowne183eae2009-03-31 15:20:22 +11004415 conf->prev_algo = mddev->layout;
4416 }
NeilBrown91adb562009-03-31 14:39:39 +11004417
4418 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4419 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4420 if (grow_stripes(conf, conf->max_nr_stripes)) {
4421 printk(KERN_ERR
4422 "raid5: couldn't allocate %dkB for buffers\n", memory);
4423 goto abort;
4424 } else
4425 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4426 memory, mdname(mddev));
4427
4428 conf->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4429 if (!conf->thread) {
4430 printk(KERN_ERR
4431 "raid5: couldn't allocate thread for %s\n",
4432 mdname(mddev));
4433 goto abort;
4434 }
4435
4436 return conf;
4437
4438 abort:
4439 if (conf) {
4440 shrink_stripes(conf);
4441 safe_put_page(conf->spare_page);
4442 kfree(conf->disks);
4443 kfree(conf->stripe_hashtbl);
4444 kfree(conf);
4445 return ERR_PTR(-EIO);
4446 } else
4447 return ERR_PTR(-ENOMEM);
4448}
4449
4450static int run(mddev_t *mddev)
4451{
4452 raid5_conf_t *conf;
4453 int working_disks = 0;
4454 mdk_rdev_t *rdev;
4455
NeilBrownf6705572006-03-27 01:18:11 -08004456 if (mddev->reshape_position != MaxSector) {
4457 /* Check that we can continue the reshape.
4458 * Currently only disks can change, it must
4459 * increase, and we must be past the point where
4460 * a stripe over-writes itself
4461 */
4462 sector_t here_new, here_old;
4463 int old_disks;
Andre Noll18b00332009-03-31 15:00:56 +11004464 int max_degraded = (mddev->level == 6 ? 2 : 1);
NeilBrownf6705572006-03-27 01:18:11 -08004465
NeilBrown88ce4932009-03-31 15:24:23 +11004466 if (mddev->new_level != mddev->level) {
NeilBrownf4168852007-02-28 20:11:53 -08004467 printk(KERN_ERR "raid5: %s: unsupported reshape "
4468 "required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004469 mdname(mddev));
4470 return -EINVAL;
4471 }
NeilBrownf6705572006-03-27 01:18:11 -08004472 old_disks = mddev->raid_disks - mddev->delta_disks;
4473 /* reshape_position must be on a new-stripe boundary, and one
NeilBrownf4168852007-02-28 20:11:53 -08004474 * further up in new geometry must map after here in old
4475 * geometry.
NeilBrownf6705572006-03-27 01:18:11 -08004476 */
4477 here_new = mddev->reshape_position;
NeilBrown784052e2009-03-31 15:19:07 +11004478 if (sector_div(here_new, (mddev->new_chunk>>9)*
NeilBrownf4168852007-02-28 20:11:53 -08004479 (mddev->raid_disks - max_degraded))) {
4480 printk(KERN_ERR "raid5: reshape_position not "
4481 "on a stripe boundary\n");
NeilBrownf6705572006-03-27 01:18:11 -08004482 return -EINVAL;
4483 }
4484 /* here_new is the stripe we will write to */
4485 here_old = mddev->reshape_position;
NeilBrownf4168852007-02-28 20:11:53 -08004486 sector_div(here_old, (mddev->chunk_size>>9)*
4487 (old_disks-max_degraded));
4488 /* here_old is the first stripe that we might need to read
4489 * from */
NeilBrownf6705572006-03-27 01:18:11 -08004490 if (here_new >= here_old) {
4491 /* Reading from the same stripe as writing to - bad */
NeilBrownf4168852007-02-28 20:11:53 -08004492 printk(KERN_ERR "raid5: reshape_position too early for "
4493 "auto-recovery - aborting.\n");
NeilBrownf6705572006-03-27 01:18:11 -08004494 return -EINVAL;
4495 }
4496 printk(KERN_INFO "raid5: reshape will continue\n");
4497 /* OK, we should be able to continue; */
NeilBrownf6705572006-03-27 01:18:11 -08004498 } else {
NeilBrown91adb562009-03-31 14:39:39 +11004499 BUG_ON(mddev->level != mddev->new_level);
4500 BUG_ON(mddev->layout != mddev->new_layout);
4501 BUG_ON(mddev->chunk_size != mddev->new_chunk);
4502 BUG_ON(mddev->delta_disks != 0);
NeilBrownf6705572006-03-27 01:18:11 -08004503 }
4504
NeilBrown245f46c2009-03-31 14:39:39 +11004505 if (mddev->private == NULL)
4506 conf = setup_conf(mddev);
4507 else
4508 conf = mddev->private;
4509
NeilBrown91adb562009-03-31 14:39:39 +11004510 if (IS_ERR(conf))
4511 return PTR_ERR(conf);
NeilBrown9ffae0c2006-01-06 00:20:32 -08004512
NeilBrown91adb562009-03-31 14:39:39 +11004513 mddev->thread = conf->thread;
4514 conf->thread = NULL;
4515 mddev->private = conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004516
Linus Torvalds1da177e2005-04-16 15:20:36 -07004517 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004518 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004519 */
NeilBrown91adb562009-03-31 14:39:39 +11004520 list_for_each_entry(rdev, &mddev->disks, same_set)
4521 if (rdev->raid_disk >= 0 &&
4522 test_bit(In_sync, &rdev->flags))
4523 working_disks++;
4524
NeilBrown02c2de82006-10-03 01:15:47 -07004525 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004526
NeilBrown16a53ec2006-06-26 00:27:38 -07004527 if (mddev->degraded > conf->max_degraded) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004528 printk(KERN_ERR "raid5: not enough operational devices for %s"
4529 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07004530 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004531 goto abort;
4532 }
4533
NeilBrown91adb562009-03-31 14:39:39 +11004534 /* device size must be a multiple of chunk size */
4535 mddev->dev_sectors &= ~(mddev->chunk_size / 512 - 1);
4536 mddev->resync_max_sectors = mddev->dev_sectors;
4537
NeilBrown16a53ec2006-06-26 00:27:38 -07004538 if (mddev->degraded > 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07004539 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08004540 if (mddev->ok_start_degraded)
4541 printk(KERN_WARNING
4542 "raid5: starting dirty degraded array: %s"
4543 "- data corruption possible.\n",
4544 mdname(mddev));
4545 else {
4546 printk(KERN_ERR
4547 "raid5: cannot start dirty degraded array for %s\n",
4548 mdname(mddev));
4549 goto abort;
4550 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004551 }
4552
Linus Torvalds1da177e2005-04-16 15:20:36 -07004553 if (mddev->degraded == 0)
4554 printk("raid5: raid level %d set %s active with %d out of %d"
NeilBrowne183eae2009-03-31 15:20:22 +11004555 " devices, algorithm %d\n", conf->level, mdname(mddev),
4556 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4557 mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004558 else
4559 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4560 " out of %d devices, algorithm %d\n", conf->level,
4561 mdname(mddev), mddev->raid_disks - mddev->degraded,
NeilBrowne183eae2009-03-31 15:20:22 +11004562 mddev->raid_disks, mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004563
4564 print_raid5_conf(conf);
4565
NeilBrownfef9c612009-03-31 15:16:46 +11004566 if (conf->reshape_progress != MaxSector) {
NeilBrownf6705572006-03-27 01:18:11 -08004567 printk("...ok start reshape thread\n");
NeilBrownfef9c612009-03-31 15:16:46 +11004568 conf->reshape_safe = conf->reshape_progress;
NeilBrownf6705572006-03-27 01:18:11 -08004569 atomic_set(&conf->reshape_stripes, 0);
4570 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4571 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4572 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4573 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4574 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4575 "%s_reshape");
NeilBrownf6705572006-03-27 01:18:11 -08004576 }
4577
Linus Torvalds1da177e2005-04-16 15:20:36 -07004578 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07004579 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07004580 */
4581 {
NeilBrown16a53ec2006-06-26 00:27:38 -07004582 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4583 int stripe = data_disks *
NeilBrown8932c2e2006-06-26 00:27:36 -07004584 (mddev->chunk_size / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004585 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4586 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4587 }
4588
4589 /* Ok, everything is just fine now */
NeilBrown5e55e2f2007-03-26 21:32:14 -08004590 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4591 printk(KERN_WARNING
4592 "raid5: failed to create sysfs attributes for %s\n",
4593 mdname(mddev));
NeilBrown7a5febe2005-05-16 21:53:16 -07004594
NeilBrown91adb562009-03-31 14:39:39 +11004595 mddev->queue->queue_lock = &conf->device_lock;
4596
NeilBrown7a5febe2005-05-16 21:53:16 -07004597 mddev->queue->unplug_fn = raid5_unplug_device;
NeilBrownf022b2f2006-10-03 01:15:56 -07004598 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown041ae522007-03-26 21:32:14 -08004599 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
NeilBrownf022b2f2006-10-03 01:15:56 -07004600
Dan Williams1f403622009-03-31 14:59:03 +11004601 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
NeilBrown7a5febe2005-05-16 21:53:16 -07004602
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08004603 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
4604
Linus Torvalds1da177e2005-04-16 15:20:36 -07004605 return 0;
4606abort:
NeilBrowne0cf8f02009-03-31 14:39:39 +11004607 md_unregister_thread(mddev->thread);
NeilBrown91adb562009-03-31 14:39:39 +11004608 mddev->thread = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004609 if (conf) {
NeilBrown91adb562009-03-31 14:39:39 +11004610 shrink_stripes(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004611 print_raid5_conf(conf);
NeilBrown16a53ec2006-06-26 00:27:38 -07004612 safe_put_page(conf->spare_page);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004613 kfree(conf->disks);
NeilBrownfccddba2006-01-06 00:20:33 -08004614 kfree(conf->stripe_hashtbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004615 kfree(conf);
4616 }
4617 mddev->private = NULL;
4618 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4619 return -EIO;
4620}
4621
4622
4623
NeilBrown3f294f42005-11-08 21:39:25 -08004624static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004625{
4626 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4627
4628 md_unregister_thread(mddev->thread);
4629 mddev->thread = NULL;
4630 shrink_stripes(conf);
NeilBrownfccddba2006-01-06 00:20:33 -08004631 kfree(conf->stripe_hashtbl);
NeilBrown041ae522007-03-26 21:32:14 -08004632 mddev->queue->backing_dev_info.congested_fn = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004633 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
NeilBrown007583c2005-11-08 21:39:30 -08004634 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004635 kfree(conf->disks);
NeilBrown96de1e62005-11-08 21:39:39 -08004636 kfree(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004637 mddev->private = NULL;
4638 return 0;
4639}
4640
Dan Williams45b42332007-07-09 11:56:43 -07004641#ifdef DEBUG
NeilBrownd710e132008-10-13 11:55:12 +11004642static void print_sh(struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004643{
4644 int i;
4645
NeilBrown16a53ec2006-06-26 00:27:38 -07004646 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4647 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4648 seq_printf(seq, "sh %llu, count %d.\n",
4649 (unsigned long long)sh->sector, atomic_read(&sh->count));
4650 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08004651 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004652 seq_printf(seq, "(cache%d: %p %ld) ",
4653 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004654 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004655 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004656}
4657
NeilBrownd710e132008-10-13 11:55:12 +11004658static void printall(struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004659{
4660 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08004661 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004662 int i;
4663
4664 spin_lock_irq(&conf->device_lock);
4665 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08004666 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004667 if (sh->raid_conf != conf)
4668 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07004669 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004670 }
4671 }
4672 spin_unlock_irq(&conf->device_lock);
4673}
4674#endif
4675
NeilBrownd710e132008-10-13 11:55:12 +11004676static void status(struct seq_file *seq, mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004677{
4678 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4679 int i;
4680
4681 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07004682 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004683 for (i = 0; i < conf->raid_disks; i++)
4684 seq_printf (seq, "%s",
4685 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08004686 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004687 seq_printf (seq, "]");
Dan Williams45b42332007-07-09 11:56:43 -07004688#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004689 seq_printf (seq, "\n");
4690 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004691#endif
4692}
4693
4694static void print_raid5_conf (raid5_conf_t *conf)
4695{
4696 int i;
4697 struct disk_info *tmp;
4698
4699 printk("RAID5 conf printout:\n");
4700 if (!conf) {
4701 printk("(conf==NULL)\n");
4702 return;
4703 }
NeilBrown02c2de82006-10-03 01:15:47 -07004704 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4705 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004706
4707 for (i = 0; i < conf->raid_disks; i++) {
4708 char b[BDEVNAME_SIZE];
4709 tmp = conf->disks + i;
4710 if (tmp->rdev)
4711 printk(" disk %d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08004712 i, !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07004713 bdevname(tmp->rdev->bdev,b));
4714 }
4715}
4716
4717static int raid5_spare_active(mddev_t *mddev)
4718{
4719 int i;
4720 raid5_conf_t *conf = mddev->private;
4721 struct disk_info *tmp;
4722
4723 for (i = 0; i < conf->raid_disks; i++) {
4724 tmp = conf->disks + i;
4725 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08004726 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07004727 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4728 unsigned long flags;
4729 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004730 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07004731 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004732 }
4733 }
4734 print_raid5_conf(conf);
4735 return 0;
4736}
4737
4738static int raid5_remove_disk(mddev_t *mddev, int number)
4739{
4740 raid5_conf_t *conf = mddev->private;
4741 int err = 0;
4742 mdk_rdev_t *rdev;
4743 struct disk_info *p = conf->disks + number;
4744
4745 print_raid5_conf(conf);
4746 rdev = p->rdev;
4747 if (rdev) {
NeilBrownec32a2b2009-03-31 15:17:38 +11004748 if (number >= conf->raid_disks &&
4749 conf->reshape_progress == MaxSector)
4750 clear_bit(In_sync, &rdev->flags);
4751
NeilBrownb2d444d2005-11-08 21:39:31 -08004752 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07004753 atomic_read(&rdev->nr_pending)) {
4754 err = -EBUSY;
4755 goto abort;
4756 }
NeilBrowndfc70642008-05-23 13:04:39 -07004757 /* Only remove non-faulty devices if recovery
4758 * isn't possible.
4759 */
4760 if (!test_bit(Faulty, &rdev->flags) &&
NeilBrownec32a2b2009-03-31 15:17:38 +11004761 mddev->degraded <= conf->max_degraded &&
4762 number < conf->raid_disks) {
NeilBrowndfc70642008-05-23 13:04:39 -07004763 err = -EBUSY;
4764 goto abort;
4765 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004766 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07004767 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004768 if (atomic_read(&rdev->nr_pending)) {
4769 /* lost the race, try later */
4770 err = -EBUSY;
4771 p->rdev = rdev;
4772 }
4773 }
4774abort:
4775
4776 print_raid5_conf(conf);
4777 return err;
4778}
4779
4780static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4781{
4782 raid5_conf_t *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10004783 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004784 int disk;
4785 struct disk_info *p;
Neil Brown6c2fce22008-06-28 08:31:31 +10004786 int first = 0;
4787 int last = conf->raid_disks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004788
NeilBrown16a53ec2006-06-26 00:27:38 -07004789 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004790 /* no point adding a device */
Neil Brown199050e2008-06-28 08:31:33 +10004791 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004792
Neil Brown6c2fce22008-06-28 08:31:31 +10004793 if (rdev->raid_disk >= 0)
4794 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004795
4796 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004797 * find the disk ... but prefer rdev->saved_raid_disk
4798 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004799 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004800 if (rdev->saved_raid_disk >= 0 &&
Neil Brown6c2fce22008-06-28 08:31:31 +10004801 rdev->saved_raid_disk >= first &&
NeilBrown16a53ec2006-06-26 00:27:38 -07004802 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4803 disk = rdev->saved_raid_disk;
4804 else
Neil Brown6c2fce22008-06-28 08:31:31 +10004805 disk = first;
4806 for ( ; disk <= last ; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004807 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004808 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004809 rdev->raid_disk = disk;
Neil Brown199050e2008-06-28 08:31:33 +10004810 err = 0;
NeilBrown72626682005-09-09 16:23:54 -07004811 if (rdev->saved_raid_disk != disk)
4812 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08004813 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004814 break;
4815 }
4816 print_raid5_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10004817 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004818}
4819
4820static int raid5_resize(mddev_t *mddev, sector_t sectors)
4821{
4822 /* no resync is happening, and there is enough space
4823 * on all devices, so we can resize.
4824 * We need to make sure resync covers any new space.
4825 * If the array is shrinking we should possibly wait until
4826 * any io in the removed space completes, but it hardly seems
4827 * worth it.
4828 */
4829 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
Dan Williams1f403622009-03-31 14:59:03 +11004830 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
4831 mddev->raid_disks));
Dan Williamsb522adc2009-03-31 15:00:31 +11004832 if (mddev->array_sectors >
4833 raid5_size(mddev, sectors, mddev->raid_disks))
4834 return -EINVAL;
Andre Nollf233ea52008-07-21 17:05:22 +10004835 set_capacity(mddev->gendisk, mddev->array_sectors);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004836 mddev->changed = 1;
Andre Noll58c0fed2009-03-31 14:33:13 +11004837 if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
4838 mddev->recovery_cp = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004839 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4840 }
Andre Noll58c0fed2009-03-31 14:33:13 +11004841 mddev->dev_sectors = sectors;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07004842 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004843 return 0;
4844}
4845
NeilBrown63c70c42006-03-27 01:18:13 -08004846static int raid5_check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08004847{
4848 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown29269552006-03-27 01:18:10 -08004849
NeilBrown88ce4932009-03-31 15:24:23 +11004850 if (mddev->delta_disks == 0 &&
4851 mddev->new_layout == mddev->layout &&
4852 mddev->new_chunk == mddev->chunk_size)
4853 return -EINVAL; /* nothing to do */
NeilBrowndba034e2008-08-05 15:54:13 +10004854 if (mddev->bitmap)
4855 /* Cannot grow a bitmap yet */
4856 return -EBUSY;
NeilBrownec32a2b2009-03-31 15:17:38 +11004857 if (mddev->degraded > conf->max_degraded)
4858 return -EINVAL;
4859 if (mddev->delta_disks < 0) {
4860 /* We might be able to shrink, but the devices must
4861 * be made bigger first.
4862 * For raid6, 4 is the minimum size.
4863 * Otherwise 2 is the minimum
4864 */
4865 int min = 2;
4866 if (mddev->level == 6)
4867 min = 4;
4868 if (mddev->raid_disks + mddev->delta_disks < min)
4869 return -EINVAL;
4870 }
NeilBrown29269552006-03-27 01:18:10 -08004871
4872 /* Can only proceed if there are plenty of stripe_heads.
4873 * We need a minimum of one full stripe,, and for sensible progress
4874 * it is best to have about 4 times that.
4875 * If we require 4 times, then the default 256 4K stripe_heads will
4876 * allow for chunk sizes up to 256K, which is probably OK.
4877 * If the chunk size is greater, user-space should request more
4878 * stripe_heads first.
4879 */
NeilBrown63c70c42006-03-27 01:18:13 -08004880 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
4881 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
NeilBrown29269552006-03-27 01:18:10 -08004882 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
NeilBrown784052e2009-03-31 15:19:07 +11004883 (max(mddev->chunk_size, mddev->new_chunk)
4884 / STRIPE_SIZE)*4);
NeilBrown29269552006-03-27 01:18:10 -08004885 return -ENOSPC;
4886 }
4887
NeilBrownec32a2b2009-03-31 15:17:38 +11004888 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
NeilBrown63c70c42006-03-27 01:18:13 -08004889}
4890
4891static int raid5_start_reshape(mddev_t *mddev)
4892{
4893 raid5_conf_t *conf = mddev_to_conf(mddev);
4894 mdk_rdev_t *rdev;
NeilBrown63c70c42006-03-27 01:18:13 -08004895 int spares = 0;
4896 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07004897 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08004898
NeilBrownf4168852007-02-28 20:11:53 -08004899 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
NeilBrown63c70c42006-03-27 01:18:13 -08004900 return -EBUSY;
4901
Cheng Renquan159ec1f2009-01-09 08:31:08 +11004902 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08004903 if (rdev->raid_disk < 0 &&
4904 !test_bit(Faulty, &rdev->flags))
4905 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08004906
NeilBrownf4168852007-02-28 20:11:53 -08004907 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
NeilBrown29269552006-03-27 01:18:10 -08004908 /* Not enough devices even to make a degraded array
4909 * of that size
4910 */
4911 return -EINVAL;
4912
NeilBrownec32a2b2009-03-31 15:17:38 +11004913 /* Refuse to reduce size of the array. Any reductions in
4914 * array size must be through explicit setting of array_size
4915 * attribute.
4916 */
4917 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
4918 < mddev->array_sectors) {
4919 printk(KERN_ERR "md: %s: array size must be reduced "
4920 "before number of disks\n", mdname(mddev));
4921 return -EINVAL;
4922 }
4923
NeilBrownf6705572006-03-27 01:18:11 -08004924 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08004925 spin_lock_irq(&conf->device_lock);
4926 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08004927 conf->raid_disks += mddev->delta_disks;
NeilBrown88ce4932009-03-31 15:24:23 +11004928 conf->prev_chunk = conf->chunk_size;
4929 conf->chunk_size = mddev->new_chunk;
4930 conf->prev_algo = conf->algorithm;
4931 conf->algorithm = mddev->new_layout;
NeilBrownfef9c612009-03-31 15:16:46 +11004932 if (mddev->delta_disks < 0)
4933 conf->reshape_progress = raid5_size(mddev, 0, 0);
4934 else
4935 conf->reshape_progress = 0;
4936 conf->reshape_safe = conf->reshape_progress;
NeilBrown86b42c72009-03-31 15:19:03 +11004937 conf->generation++;
NeilBrown29269552006-03-27 01:18:10 -08004938 spin_unlock_irq(&conf->device_lock);
4939
4940 /* Add some new drives, as many as will fit.
4941 * We know there are enough to make the newly sized array work.
4942 */
Cheng Renquan159ec1f2009-01-09 08:31:08 +11004943 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08004944 if (rdev->raid_disk < 0 &&
4945 !test_bit(Faulty, &rdev->flags)) {
Neil Brown199050e2008-06-28 08:31:33 +10004946 if (raid5_add_disk(mddev, rdev) == 0) {
NeilBrown29269552006-03-27 01:18:10 -08004947 char nm[20];
4948 set_bit(In_sync, &rdev->flags);
NeilBrown29269552006-03-27 01:18:10 -08004949 added_devices++;
NeilBrown5fd6c1d2006-06-26 00:27:40 -07004950 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08004951 sprintf(nm, "rd%d", rdev->raid_disk);
NeilBrown5e55e2f2007-03-26 21:32:14 -08004952 if (sysfs_create_link(&mddev->kobj,
4953 &rdev->kobj, nm))
4954 printk(KERN_WARNING
4955 "raid5: failed to create "
4956 " link %s for %s\n",
4957 nm, mdname(mddev));
NeilBrown29269552006-03-27 01:18:10 -08004958 } else
4959 break;
4960 }
4961
NeilBrownec32a2b2009-03-31 15:17:38 +11004962 if (mddev->delta_disks > 0) {
4963 spin_lock_irqsave(&conf->device_lock, flags);
4964 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks)
4965 - added_devices;
4966 spin_unlock_irqrestore(&conf->device_lock, flags);
4967 }
NeilBrown63c70c42006-03-27 01:18:13 -08004968 mddev->raid_disks = conf->raid_disks;
NeilBrownf6705572006-03-27 01:18:11 -08004969 mddev->reshape_position = 0;
NeilBrown850b2b42006-10-03 01:15:46 -07004970 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08004971
NeilBrown29269552006-03-27 01:18:10 -08004972 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4973 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4974 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4975 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4976 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4977 "%s_reshape");
4978 if (!mddev->sync_thread) {
4979 mddev->recovery = 0;
4980 spin_lock_irq(&conf->device_lock);
4981 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11004982 conf->reshape_progress = MaxSector;
NeilBrown29269552006-03-27 01:18:10 -08004983 spin_unlock_irq(&conf->device_lock);
4984 return -EAGAIN;
4985 }
NeilBrownc8f517c2009-03-31 15:28:40 +11004986 conf->reshape_checkpoint = jiffies;
NeilBrown29269552006-03-27 01:18:10 -08004987 md_wakeup_thread(mddev->sync_thread);
4988 md_new_event(mddev);
4989 return 0;
4990}
NeilBrown29269552006-03-27 01:18:10 -08004991
NeilBrownec32a2b2009-03-31 15:17:38 +11004992/* This is called from the reshape thread and should make any
4993 * changes needed in 'conf'
4994 */
NeilBrown29269552006-03-27 01:18:10 -08004995static void end_reshape(raid5_conf_t *conf)
4996{
NeilBrown29269552006-03-27 01:18:10 -08004997
NeilBrownf6705572006-03-27 01:18:11 -08004998 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
Dan Williams80c3a6c2009-03-17 18:10:40 -07004999
NeilBrownf6705572006-03-27 01:18:11 -08005000 spin_lock_irq(&conf->device_lock);
NeilBrowncea9c222009-03-31 15:15:05 +11005001 conf->previous_raid_disks = conf->raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11005002 conf->reshape_progress = MaxSector;
NeilBrownf6705572006-03-27 01:18:11 -08005003 spin_unlock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11005004 wake_up(&conf->wait_for_overlap);
NeilBrown16a53ec2006-06-26 00:27:38 -07005005
5006 /* read-ahead size must cover two whole stripes, which is
5007 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5008 */
5009 {
NeilBrowncea9c222009-03-31 15:15:05 +11005010 int data_disks = conf->raid_disks - conf->max_degraded;
5011 int stripe = data_disks * (conf->chunk_size
5012 / PAGE_SIZE);
NeilBrown16a53ec2006-06-26 00:27:38 -07005013 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5014 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5015 }
NeilBrown29269552006-03-27 01:18:10 -08005016 }
NeilBrown29269552006-03-27 01:18:10 -08005017}
5018
NeilBrownec32a2b2009-03-31 15:17:38 +11005019/* This is called from the raid5d thread with mddev_lock held.
5020 * It makes config changes to the device.
5021 */
NeilBrowncea9c222009-03-31 15:15:05 +11005022static void raid5_finish_reshape(mddev_t *mddev)
5023{
5024 struct block_device *bdev;
NeilBrown88ce4932009-03-31 15:24:23 +11005025 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrowncea9c222009-03-31 15:15:05 +11005026
5027 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5028
NeilBrownec32a2b2009-03-31 15:17:38 +11005029 if (mddev->delta_disks > 0) {
5030 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5031 set_capacity(mddev->gendisk, mddev->array_sectors);
5032 mddev->changed = 1;
NeilBrowncea9c222009-03-31 15:15:05 +11005033
NeilBrownec32a2b2009-03-31 15:17:38 +11005034 bdev = bdget_disk(mddev->gendisk, 0);
5035 if (bdev) {
5036 mutex_lock(&bdev->bd_inode->i_mutex);
5037 i_size_write(bdev->bd_inode,
5038 (loff_t)mddev->array_sectors << 9);
5039 mutex_unlock(&bdev->bd_inode->i_mutex);
5040 bdput(bdev);
5041 }
5042 } else {
5043 int d;
NeilBrownec32a2b2009-03-31 15:17:38 +11005044 mddev->degraded = conf->raid_disks;
5045 for (d = 0; d < conf->raid_disks ; d++)
5046 if (conf->disks[d].rdev &&
5047 test_bit(In_sync,
5048 &conf->disks[d].rdev->flags))
5049 mddev->degraded--;
5050 for (d = conf->raid_disks ;
5051 d < conf->raid_disks - mddev->delta_disks;
5052 d++)
5053 raid5_remove_disk(mddev, d);
NeilBrowncea9c222009-03-31 15:15:05 +11005054 }
NeilBrown88ce4932009-03-31 15:24:23 +11005055 mddev->layout = conf->algorithm;
5056 mddev->chunk_size = conf->chunk_size;
NeilBrownec32a2b2009-03-31 15:17:38 +11005057 mddev->reshape_position = MaxSector;
5058 mddev->delta_disks = 0;
NeilBrowncea9c222009-03-31 15:15:05 +11005059 }
5060}
5061
NeilBrown72626682005-09-09 16:23:54 -07005062static void raid5_quiesce(mddev_t *mddev, int state)
5063{
5064 raid5_conf_t *conf = mddev_to_conf(mddev);
5065
5066 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08005067 case 2: /* resume for a suspend */
5068 wake_up(&conf->wait_for_overlap);
5069 break;
5070
NeilBrown72626682005-09-09 16:23:54 -07005071 case 1: /* stop all writes */
5072 spin_lock_irq(&conf->device_lock);
5073 conf->quiesce = 1;
5074 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08005075 atomic_read(&conf->active_stripes) == 0 &&
5076 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07005077 conf->device_lock, /* nothing */);
5078 spin_unlock_irq(&conf->device_lock);
5079 break;
5080
5081 case 0: /* re-enable writes */
5082 spin_lock_irq(&conf->device_lock);
5083 conf->quiesce = 0;
5084 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08005085 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07005086 spin_unlock_irq(&conf->device_lock);
5087 break;
5088 }
NeilBrown72626682005-09-09 16:23:54 -07005089}
NeilBrownb15c2e52006-01-06 00:20:16 -08005090
NeilBrownd562b0c2009-03-31 14:39:39 +11005091
5092static void *raid5_takeover_raid1(mddev_t *mddev)
5093{
5094 int chunksect;
5095
5096 if (mddev->raid_disks != 2 ||
5097 mddev->degraded > 1)
5098 return ERR_PTR(-EINVAL);
5099
5100 /* Should check if there are write-behind devices? */
5101
5102 chunksect = 64*2; /* 64K by default */
5103
5104 /* The array must be an exact multiple of chunksize */
5105 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5106 chunksect >>= 1;
5107
5108 if ((chunksect<<9) < STRIPE_SIZE)
5109 /* array size does not allow a suitable chunk size */
5110 return ERR_PTR(-EINVAL);
5111
5112 mddev->new_level = 5;
5113 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
5114 mddev->new_chunk = chunksect << 9;
5115
5116 return setup_conf(mddev);
5117}
5118
NeilBrownfc9739c2009-03-31 14:57:20 +11005119static void *raid5_takeover_raid6(mddev_t *mddev)
5120{
5121 int new_layout;
5122
5123 switch (mddev->layout) {
5124 case ALGORITHM_LEFT_ASYMMETRIC_6:
5125 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5126 break;
5127 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5128 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5129 break;
5130 case ALGORITHM_LEFT_SYMMETRIC_6:
5131 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5132 break;
5133 case ALGORITHM_RIGHT_SYMMETRIC_6:
5134 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5135 break;
5136 case ALGORITHM_PARITY_0_6:
5137 new_layout = ALGORITHM_PARITY_0;
5138 break;
5139 case ALGORITHM_PARITY_N:
5140 new_layout = ALGORITHM_PARITY_N;
5141 break;
5142 default:
5143 return ERR_PTR(-EINVAL);
5144 }
5145 mddev->new_level = 5;
5146 mddev->new_layout = new_layout;
5147 mddev->delta_disks = -1;
5148 mddev->raid_disks -= 1;
5149 return setup_conf(mddev);
5150}
5151
NeilBrownd562b0c2009-03-31 14:39:39 +11005152
NeilBrownb3546032009-03-31 14:56:41 +11005153static int raid5_reconfig(mddev_t *mddev, int new_layout, int new_chunk)
5154{
NeilBrown88ce4932009-03-31 15:24:23 +11005155 /* For a 2-drive array, the layout and chunk size can be changed
5156 * immediately as not restriping is needed.
5157 * For larger arrays we record the new value - after validation
5158 * to be used by a reshape pass.
NeilBrownb3546032009-03-31 14:56:41 +11005159 */
5160 raid5_conf_t *conf = mddev_to_conf(mddev);
5161
5162 if (new_layout >= 0 && !algorithm_valid_raid5(new_layout))
5163 return -EINVAL;
5164 if (new_chunk > 0) {
5165 if (new_chunk & (new_chunk-1))
5166 /* not a power of 2 */
5167 return -EINVAL;
5168 if (new_chunk < PAGE_SIZE)
5169 return -EINVAL;
5170 if (mddev->array_sectors & ((new_chunk>>9)-1))
5171 /* not factor of array size */
5172 return -EINVAL;
5173 }
5174
5175 /* They look valid */
5176
NeilBrown88ce4932009-03-31 15:24:23 +11005177 if (mddev->raid_disks == 2) {
NeilBrownb3546032009-03-31 14:56:41 +11005178
NeilBrown88ce4932009-03-31 15:24:23 +11005179 if (new_layout >= 0) {
5180 conf->algorithm = new_layout;
5181 mddev->layout = mddev->new_layout = new_layout;
5182 }
5183 if (new_chunk > 0) {
5184 conf->chunk_size = new_chunk;
5185 mddev->chunk_size = mddev->new_chunk = new_chunk;
5186 }
5187 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5188 md_wakeup_thread(mddev->thread);
5189 } else {
5190 if (new_layout >= 0)
5191 mddev->new_layout = new_layout;
5192 if (new_chunk > 0)
5193 mddev->new_chunk = new_chunk;
NeilBrownb3546032009-03-31 14:56:41 +11005194 }
NeilBrown88ce4932009-03-31 15:24:23 +11005195 return 0;
5196}
5197
5198static int raid6_reconfig(mddev_t *mddev, int new_layout, int new_chunk)
5199{
5200 if (new_layout >= 0 && !algorithm_valid_raid6(new_layout))
5201 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005202 if (new_chunk > 0) {
NeilBrown88ce4932009-03-31 15:24:23 +11005203 if (new_chunk & (new_chunk-1))
5204 /* not a power of 2 */
5205 return -EINVAL;
5206 if (new_chunk < PAGE_SIZE)
5207 return -EINVAL;
5208 if (mddev->array_sectors & ((new_chunk>>9)-1))
5209 /* not factor of array size */
5210 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005211 }
NeilBrown88ce4932009-03-31 15:24:23 +11005212
5213 /* They look valid */
5214
5215 if (new_layout >= 0)
5216 mddev->new_layout = new_layout;
5217 if (new_chunk > 0)
5218 mddev->new_chunk = new_chunk;
5219
NeilBrownb3546032009-03-31 14:56:41 +11005220 return 0;
5221}
5222
NeilBrownd562b0c2009-03-31 14:39:39 +11005223static void *raid5_takeover(mddev_t *mddev)
5224{
5225 /* raid5 can take over:
5226 * raid0 - if all devices are the same - make it a raid4 layout
5227 * raid1 - if there are two drives. We need to know the chunk size
5228 * raid4 - trivial - just use a raid4 layout.
5229 * raid6 - Providing it is a *_6 layout
5230 *
5231 * For now, just do raid1
5232 */
5233
5234 if (mddev->level == 1)
5235 return raid5_takeover_raid1(mddev);
NeilBrowne9d47582009-03-31 14:57:09 +11005236 if (mddev->level == 4) {
5237 mddev->new_layout = ALGORITHM_PARITY_N;
5238 mddev->new_level = 5;
5239 return setup_conf(mddev);
5240 }
NeilBrownfc9739c2009-03-31 14:57:20 +11005241 if (mddev->level == 6)
5242 return raid5_takeover_raid6(mddev);
NeilBrownd562b0c2009-03-31 14:39:39 +11005243
5244 return ERR_PTR(-EINVAL);
5245}
5246
5247
NeilBrown245f46c2009-03-31 14:39:39 +11005248static struct mdk_personality raid5_personality;
5249
5250static void *raid6_takeover(mddev_t *mddev)
5251{
5252 /* Currently can only take over a raid5. We map the
5253 * personality to an equivalent raid6 personality
5254 * with the Q block at the end.
5255 */
5256 int new_layout;
5257
5258 if (mddev->pers != &raid5_personality)
5259 return ERR_PTR(-EINVAL);
5260 if (mddev->degraded > 1)
5261 return ERR_PTR(-EINVAL);
5262 if (mddev->raid_disks > 253)
5263 return ERR_PTR(-EINVAL);
5264 if (mddev->raid_disks < 3)
5265 return ERR_PTR(-EINVAL);
5266
5267 switch (mddev->layout) {
5268 case ALGORITHM_LEFT_ASYMMETRIC:
5269 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5270 break;
5271 case ALGORITHM_RIGHT_ASYMMETRIC:
5272 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5273 break;
5274 case ALGORITHM_LEFT_SYMMETRIC:
5275 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5276 break;
5277 case ALGORITHM_RIGHT_SYMMETRIC:
5278 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5279 break;
5280 case ALGORITHM_PARITY_0:
5281 new_layout = ALGORITHM_PARITY_0_6;
5282 break;
5283 case ALGORITHM_PARITY_N:
5284 new_layout = ALGORITHM_PARITY_N;
5285 break;
5286 default:
5287 return ERR_PTR(-EINVAL);
5288 }
5289 mddev->new_level = 6;
5290 mddev->new_layout = new_layout;
5291 mddev->delta_disks = 1;
5292 mddev->raid_disks += 1;
5293 return setup_conf(mddev);
5294}
5295
5296
NeilBrown16a53ec2006-06-26 00:27:38 -07005297static struct mdk_personality raid6_personality =
5298{
5299 .name = "raid6",
5300 .level = 6,
5301 .owner = THIS_MODULE,
5302 .make_request = make_request,
5303 .run = run,
5304 .stop = stop,
5305 .status = status,
5306 .error_handler = error,
5307 .hot_add_disk = raid5_add_disk,
5308 .hot_remove_disk= raid5_remove_disk,
5309 .spare_active = raid5_spare_active,
5310 .sync_request = sync_request,
5311 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005312 .size = raid5_size,
NeilBrownf4168852007-02-28 20:11:53 -08005313 .check_reshape = raid5_check_reshape,
5314 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005315 .finish_reshape = raid5_finish_reshape,
NeilBrown16a53ec2006-06-26 00:27:38 -07005316 .quiesce = raid5_quiesce,
NeilBrown245f46c2009-03-31 14:39:39 +11005317 .takeover = raid6_takeover,
NeilBrown88ce4932009-03-31 15:24:23 +11005318 .reconfig = raid6_reconfig,
NeilBrown16a53ec2006-06-26 00:27:38 -07005319};
NeilBrown2604b702006-01-06 00:20:36 -08005320static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005321{
5322 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08005323 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005324 .owner = THIS_MODULE,
5325 .make_request = make_request,
5326 .run = run,
5327 .stop = stop,
5328 .status = status,
5329 .error_handler = error,
5330 .hot_add_disk = raid5_add_disk,
5331 .hot_remove_disk= raid5_remove_disk,
5332 .spare_active = raid5_spare_active,
5333 .sync_request = sync_request,
5334 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005335 .size = raid5_size,
NeilBrown63c70c42006-03-27 01:18:13 -08005336 .check_reshape = raid5_check_reshape,
5337 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005338 .finish_reshape = raid5_finish_reshape,
NeilBrown72626682005-09-09 16:23:54 -07005339 .quiesce = raid5_quiesce,
NeilBrownd562b0c2009-03-31 14:39:39 +11005340 .takeover = raid5_takeover,
NeilBrownb3546032009-03-31 14:56:41 +11005341 .reconfig = raid5_reconfig,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005342};
5343
NeilBrown2604b702006-01-06 00:20:36 -08005344static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005345{
NeilBrown2604b702006-01-06 00:20:36 -08005346 .name = "raid4",
5347 .level = 4,
5348 .owner = THIS_MODULE,
5349 .make_request = make_request,
5350 .run = run,
5351 .stop = stop,
5352 .status = status,
5353 .error_handler = error,
5354 .hot_add_disk = raid5_add_disk,
5355 .hot_remove_disk= raid5_remove_disk,
5356 .spare_active = raid5_spare_active,
5357 .sync_request = sync_request,
5358 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005359 .size = raid5_size,
NeilBrown3d378902007-03-26 21:32:13 -08005360 .check_reshape = raid5_check_reshape,
5361 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005362 .finish_reshape = raid5_finish_reshape,
NeilBrown2604b702006-01-06 00:20:36 -08005363 .quiesce = raid5_quiesce,
5364};
5365
5366static int __init raid5_init(void)
5367{
NeilBrown16a53ec2006-06-26 00:27:38 -07005368 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005369 register_md_personality(&raid5_personality);
5370 register_md_personality(&raid4_personality);
5371 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005372}
5373
NeilBrown2604b702006-01-06 00:20:36 -08005374static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005375{
NeilBrown16a53ec2006-06-26 00:27:38 -07005376 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005377 unregister_md_personality(&raid5_personality);
5378 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005379}
5380
5381module_init(raid5_init);
5382module_exit(raid5_exit);
5383MODULE_LICENSE("GPL");
5384MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08005385MODULE_ALIAS("md-raid5");
5386MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08005387MODULE_ALIAS("md-level-5");
5388MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07005389MODULE_ALIAS("md-personality-8"); /* RAID6 */
5390MODULE_ALIAS("md-raid6");
5391MODULE_ALIAS("md-level-6");
5392
5393/* This used to be two separate modules, they were: */
5394MODULE_ALIAS("raid5");
5395MODULE_ALIAS("raid6");