blob: 826eb3467357f72af5952599525bc93355f5279c [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,
NeilBrowna8c906c2009-06-09 14:39:59 +1000365 int previous, int noblock, int noquiesce)
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,
NeilBrowna8c906c2009-06-09 14:39:59 +1000375 conf->quiesce == 0 || noquiesce,
NeilBrown72626682005-09-09 16:23:54 -0700376 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;
Andre Noll09c9e5f2009-06-18 08:45:55 +10001277 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1278 : conf->chunk_sectors;
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;
Andre Noll09c9e5f2009-06-18 08:45:55 +10001483 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1484 : conf->chunk_sectors;
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 =
Andre Noll09c9e5f2009-06-18 08:45:55 +10002000 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
NeilBrown911d4ee2009-03-31 14:39:38 +11002001 int dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002002 int chunk_offset = sector_div(stripe, sectors_per_chunk);
NeilBrown112bf892009-03-31 14:39:38 +11002003 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002004
NeilBrown112bf892009-03-31 14:39:38 +11002005 raid5_compute_sector(conf,
2006 stripe * (disks - conf->max_degraded)
NeilBrownb875e532006-12-10 02:20:49 -08002007 *sectors_per_chunk + chunk_offset,
NeilBrown112bf892009-03-31 14:39:38 +11002008 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11002009 &dd_idx, sh);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002010}
2011
Dan Williamsa4456852007-07-09 11:56:43 -07002012static void
Dan Williams1fe797e2008-06-28 09:16:30 +10002013handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002014 struct stripe_head_state *s, int disks,
2015 struct bio **return_bi)
2016{
2017 int i;
2018 for (i = disks; i--; ) {
2019 struct bio *bi;
2020 int bitmap_end = 0;
2021
2022 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2023 mdk_rdev_t *rdev;
2024 rcu_read_lock();
2025 rdev = rcu_dereference(conf->disks[i].rdev);
2026 if (rdev && test_bit(In_sync, &rdev->flags))
2027 /* multiple read failures in one stripe */
2028 md_error(conf->mddev, rdev);
2029 rcu_read_unlock();
2030 }
2031 spin_lock_irq(&conf->device_lock);
2032 /* fail all writes first */
2033 bi = sh->dev[i].towrite;
2034 sh->dev[i].towrite = NULL;
2035 if (bi) {
2036 s->to_write--;
2037 bitmap_end = 1;
2038 }
2039
2040 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2041 wake_up(&conf->wait_for_overlap);
2042
2043 while (bi && bi->bi_sector <
2044 sh->dev[i].sector + STRIPE_SECTORS) {
2045 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2046 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002047 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002048 md_write_end(conf->mddev);
2049 bi->bi_next = *return_bi;
2050 *return_bi = bi;
2051 }
2052 bi = nextbi;
2053 }
2054 /* and fail all 'written' */
2055 bi = sh->dev[i].written;
2056 sh->dev[i].written = NULL;
2057 if (bi) bitmap_end = 1;
2058 while (bi && bi->bi_sector <
2059 sh->dev[i].sector + STRIPE_SECTORS) {
2060 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2061 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002062 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002063 md_write_end(conf->mddev);
2064 bi->bi_next = *return_bi;
2065 *return_bi = bi;
2066 }
2067 bi = bi2;
2068 }
2069
Dan Williamsb5e98d62007-01-02 13:52:31 -07002070 /* fail any reads if this device is non-operational and
2071 * the data has not reached the cache yet.
2072 */
2073 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2074 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2075 test_bit(R5_ReadError, &sh->dev[i].flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002076 bi = sh->dev[i].toread;
2077 sh->dev[i].toread = NULL;
2078 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2079 wake_up(&conf->wait_for_overlap);
2080 if (bi) s->to_read--;
2081 while (bi && bi->bi_sector <
2082 sh->dev[i].sector + STRIPE_SECTORS) {
2083 struct bio *nextbi =
2084 r5_next_bio(bi, sh->dev[i].sector);
2085 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002086 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002087 bi->bi_next = *return_bi;
2088 *return_bi = bi;
2089 }
2090 bi = nextbi;
2091 }
2092 }
2093 spin_unlock_irq(&conf->device_lock);
2094 if (bitmap_end)
2095 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2096 STRIPE_SECTORS, 0, 0);
2097 }
2098
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002099 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2100 if (atomic_dec_and_test(&conf->pending_full_writes))
2101 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002102}
2103
Dan Williams1fe797e2008-06-28 09:16:30 +10002104/* fetch_block5 - checks the given member device to see if its data needs
2105 * to be read or computed to satisfy a request.
2106 *
2107 * Returns 1 when no more member devices need to be checked, otherwise returns
2108 * 0 to tell the loop in handle_stripe_fill5 to continue
Dan Williamsf38e1212007-01-02 13:52:30 -07002109 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002110static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2111 int disk_idx, int disks)
Dan Williamsf38e1212007-01-02 13:52:30 -07002112{
2113 struct r5dev *dev = &sh->dev[disk_idx];
2114 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2115
Dan Williamsf38e1212007-01-02 13:52:30 -07002116 /* is the data in this block needed, and can we get it? */
2117 if (!test_bit(R5_LOCKED, &dev->flags) &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002118 !test_bit(R5_UPTODATE, &dev->flags) &&
2119 (dev->toread ||
2120 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2121 s->syncing || s->expanding ||
2122 (s->failed &&
2123 (failed_dev->toread ||
2124 (failed_dev->towrite &&
2125 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002126 /* We would like to get this block, possibly by computing it,
2127 * otherwise read it if the backing disk is insync
Dan Williamsf38e1212007-01-02 13:52:30 -07002128 */
2129 if ((s->uptodate == disks - 1) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10002130 (s->failed && disk_idx == s->failed_num)) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002131 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2132 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
Dan Williamsf38e1212007-01-02 13:52:30 -07002133 set_bit(R5_Wantcompute, &dev->flags);
2134 sh->ops.target = disk_idx;
2135 s->req_compute = 1;
Dan Williamsf38e1212007-01-02 13:52:30 -07002136 /* Careful: from this point on 'uptodate' is in the eye
2137 * of raid5_run_ops which services 'compute' operations
2138 * before writes. R5_Wantcompute flags a block that will
2139 * be R5_UPTODATE by the time it is needed for a
2140 * subsequent operation.
2141 */
2142 s->uptodate++;
Dan Williams1fe797e2008-06-28 09:16:30 +10002143 return 1; /* uptodate + compute == disks */
Dan Williams7a1fc532008-07-10 04:54:57 -07002144 } else if (test_bit(R5_Insync, &dev->flags)) {
Dan Williamsf38e1212007-01-02 13:52:30 -07002145 set_bit(R5_LOCKED, &dev->flags);
2146 set_bit(R5_Wantread, &dev->flags);
Dan Williamsf38e1212007-01-02 13:52:30 -07002147 s->locked++;
2148 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2149 s->syncing);
2150 }
2151 }
2152
Dan Williams1fe797e2008-06-28 09:16:30 +10002153 return 0;
Dan Williamsf38e1212007-01-02 13:52:30 -07002154}
2155
Dan Williams1fe797e2008-06-28 09:16:30 +10002156/**
2157 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2158 */
2159static void handle_stripe_fill5(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002160 struct stripe_head_state *s, int disks)
2161{
2162 int i;
Dan Williamsf38e1212007-01-02 13:52:30 -07002163
Dan Williamsf38e1212007-01-02 13:52:30 -07002164 /* look for blocks to read/compute, skip this if a compute
2165 * is already in flight, or if the stripe contents are in the
2166 * midst of changing due to a write
2167 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002168 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002169 !sh->reconstruct_state)
Dan Williamsf38e1212007-01-02 13:52:30 -07002170 for (i = disks; i--; )
Dan Williams1fe797e2008-06-28 09:16:30 +10002171 if (fetch_block5(sh, s, i, disks))
Dan Williamsf38e1212007-01-02 13:52:30 -07002172 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002173 set_bit(STRIPE_HANDLE, &sh->state);
2174}
2175
Dan Williams1fe797e2008-06-28 09:16:30 +10002176static void handle_stripe_fill6(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002177 struct stripe_head_state *s, struct r6_state *r6s,
2178 int disks)
2179{
2180 int i;
2181 for (i = disks; i--; ) {
2182 struct r5dev *dev = &sh->dev[i];
2183 if (!test_bit(R5_LOCKED, &dev->flags) &&
2184 !test_bit(R5_UPTODATE, &dev->flags) &&
2185 (dev->toread || (dev->towrite &&
2186 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2187 s->syncing || s->expanding ||
2188 (s->failed >= 1 &&
2189 (sh->dev[r6s->failed_num[0]].toread ||
2190 s->to_write)) ||
2191 (s->failed >= 2 &&
2192 (sh->dev[r6s->failed_num[1]].toread ||
2193 s->to_write)))) {
2194 /* we would like to get this block, possibly
2195 * by computing it, but we might not be able to
2196 */
Dan Williamsc3378692008-06-05 22:45:54 -07002197 if ((s->uptodate == disks - 1) &&
2198 (s->failed && (i == r6s->failed_num[0] ||
2199 i == r6s->failed_num[1]))) {
Dan Williams45b42332007-07-09 11:56:43 -07002200 pr_debug("Computing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002201 (unsigned long long)sh->sector, i);
2202 compute_block_1(sh, i, 0);
2203 s->uptodate++;
2204 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2205 /* Computing 2-failure is *very* expensive; only
2206 * do it if failed >= 2
2207 */
2208 int other;
2209 for (other = disks; other--; ) {
2210 if (other == i)
2211 continue;
2212 if (!test_bit(R5_UPTODATE,
2213 &sh->dev[other].flags))
2214 break;
2215 }
2216 BUG_ON(other < 0);
Dan Williams45b42332007-07-09 11:56:43 -07002217 pr_debug("Computing stripe %llu blocks %d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002218 (unsigned long long)sh->sector,
2219 i, other);
2220 compute_block_2(sh, i, other);
2221 s->uptodate += 2;
2222 } else if (test_bit(R5_Insync, &dev->flags)) {
2223 set_bit(R5_LOCKED, &dev->flags);
2224 set_bit(R5_Wantread, &dev->flags);
2225 s->locked++;
Dan Williams45b42332007-07-09 11:56:43 -07002226 pr_debug("Reading block %d (sync=%d)\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002227 i, s->syncing);
2228 }
2229 }
2230 }
2231 set_bit(STRIPE_HANDLE, &sh->state);
2232}
2233
2234
Dan Williams1fe797e2008-06-28 09:16:30 +10002235/* handle_stripe_clean_event
Dan Williamsa4456852007-07-09 11:56:43 -07002236 * any written block on an uptodate or failed drive can be returned.
2237 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2238 * never LOCKED, so we don't need to test 'failed' directly.
2239 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002240static void handle_stripe_clean_event(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002241 struct stripe_head *sh, int disks, struct bio **return_bi)
2242{
2243 int i;
2244 struct r5dev *dev;
2245
2246 for (i = disks; i--; )
2247 if (sh->dev[i].written) {
2248 dev = &sh->dev[i];
2249 if (!test_bit(R5_LOCKED, &dev->flags) &&
2250 test_bit(R5_UPTODATE, &dev->flags)) {
2251 /* We can return any write requests */
2252 struct bio *wbi, *wbi2;
2253 int bitmap_end = 0;
Dan Williams45b42332007-07-09 11:56:43 -07002254 pr_debug("Return write for disc %d\n", i);
Dan Williamsa4456852007-07-09 11:56:43 -07002255 spin_lock_irq(&conf->device_lock);
2256 wbi = dev->written;
2257 dev->written = NULL;
2258 while (wbi && wbi->bi_sector <
2259 dev->sector + STRIPE_SECTORS) {
2260 wbi2 = r5_next_bio(wbi, dev->sector);
Jens Axboe960e7392008-08-15 10:41:18 +02002261 if (!raid5_dec_bi_phys_segments(wbi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002262 md_write_end(conf->mddev);
2263 wbi->bi_next = *return_bi;
2264 *return_bi = wbi;
2265 }
2266 wbi = wbi2;
2267 }
2268 if (dev->towrite == NULL)
2269 bitmap_end = 1;
2270 spin_unlock_irq(&conf->device_lock);
2271 if (bitmap_end)
2272 bitmap_endwrite(conf->mddev->bitmap,
2273 sh->sector,
2274 STRIPE_SECTORS,
2275 !test_bit(STRIPE_DEGRADED, &sh->state),
2276 0);
2277 }
2278 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002279
2280 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2281 if (atomic_dec_and_test(&conf->pending_full_writes))
2282 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002283}
2284
Dan Williams1fe797e2008-06-28 09:16:30 +10002285static void handle_stripe_dirtying5(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002286 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2287{
2288 int rmw = 0, rcw = 0, i;
2289 for (i = disks; i--; ) {
2290 /* would I have to read this buffer for read_modify_write */
2291 struct r5dev *dev = &sh->dev[i];
2292 if ((dev->towrite || i == sh->pd_idx) &&
2293 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002294 !(test_bit(R5_UPTODATE, &dev->flags) ||
2295 test_bit(R5_Wantcompute, &dev->flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002296 if (test_bit(R5_Insync, &dev->flags))
2297 rmw++;
2298 else
2299 rmw += 2*disks; /* cannot read it */
2300 }
2301 /* Would I have to read this buffer for reconstruct_write */
2302 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2303 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002304 !(test_bit(R5_UPTODATE, &dev->flags) ||
2305 test_bit(R5_Wantcompute, &dev->flags))) {
2306 if (test_bit(R5_Insync, &dev->flags)) rcw++;
Dan Williamsa4456852007-07-09 11:56:43 -07002307 else
2308 rcw += 2*disks;
2309 }
2310 }
Dan Williams45b42332007-07-09 11:56:43 -07002311 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002312 (unsigned long long)sh->sector, rmw, rcw);
2313 set_bit(STRIPE_HANDLE, &sh->state);
2314 if (rmw < rcw && rmw > 0)
2315 /* prefer read-modify-write, but need to get some data */
2316 for (i = disks; i--; ) {
2317 struct r5dev *dev = &sh->dev[i];
2318 if ((dev->towrite || i == sh->pd_idx) &&
2319 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002320 !(test_bit(R5_UPTODATE, &dev->flags) ||
2321 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002322 test_bit(R5_Insync, &dev->flags)) {
2323 if (
2324 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002325 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002326 "%d for r-m-w\n", i);
2327 set_bit(R5_LOCKED, &dev->flags);
2328 set_bit(R5_Wantread, &dev->flags);
2329 s->locked++;
2330 } else {
2331 set_bit(STRIPE_DELAYED, &sh->state);
2332 set_bit(STRIPE_HANDLE, &sh->state);
2333 }
2334 }
2335 }
2336 if (rcw <= rmw && rcw > 0)
2337 /* want reconstruct write, but need to get some data */
2338 for (i = disks; i--; ) {
2339 struct r5dev *dev = &sh->dev[i];
2340 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2341 i != sh->pd_idx &&
2342 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002343 !(test_bit(R5_UPTODATE, &dev->flags) ||
2344 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002345 test_bit(R5_Insync, &dev->flags)) {
2346 if (
2347 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002348 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002349 "%d for Reconstruct\n", i);
2350 set_bit(R5_LOCKED, &dev->flags);
2351 set_bit(R5_Wantread, &dev->flags);
2352 s->locked++;
2353 } else {
2354 set_bit(STRIPE_DELAYED, &sh->state);
2355 set_bit(STRIPE_HANDLE, &sh->state);
2356 }
2357 }
2358 }
2359 /* now if nothing is locked, and if we have enough data,
2360 * we can start a write request
2361 */
Dan Williamsf38e1212007-01-02 13:52:30 -07002362 /* since handle_stripe can be called at any time we need to handle the
2363 * case where a compute block operation has been submitted and then a
2364 * subsequent call wants to start a write request. raid5_run_ops only
2365 * handles the case where compute block and postxor are requested
2366 * simultaneously. If this is not the case then new writes need to be
2367 * held off until the compute completes.
2368 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002369 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2370 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2371 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
Dan Williams1fe797e2008-06-28 09:16:30 +10002372 schedule_reconstruction5(sh, s, rcw == 0, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002373}
2374
Dan Williams1fe797e2008-06-28 09:16:30 +10002375static void handle_stripe_dirtying6(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002376 struct stripe_head *sh, struct stripe_head_state *s,
2377 struct r6_state *r6s, int disks)
2378{
2379 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
NeilBrown34e04e82009-03-31 15:10:16 +11002380 int qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07002381 for (i = disks; i--; ) {
2382 struct r5dev *dev = &sh->dev[i];
2383 /* Would I have to read this buffer for reconstruct_write */
2384 if (!test_bit(R5_OVERWRITE, &dev->flags)
2385 && i != pd_idx && i != qd_idx
2386 && (!test_bit(R5_LOCKED, &dev->flags)
2387 ) &&
2388 !test_bit(R5_UPTODATE, &dev->flags)) {
2389 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2390 else {
Dan Williams45b42332007-07-09 11:56:43 -07002391 pr_debug("raid6: must_compute: "
Dan Williamsa4456852007-07-09 11:56:43 -07002392 "disk %d flags=%#lx\n", i, dev->flags);
2393 must_compute++;
2394 }
2395 }
2396 }
Dan Williams45b42332007-07-09 11:56:43 -07002397 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002398 (unsigned long long)sh->sector, rcw, must_compute);
2399 set_bit(STRIPE_HANDLE, &sh->state);
2400
2401 if (rcw > 0)
2402 /* want reconstruct write, but need to get some data */
2403 for (i = disks; i--; ) {
2404 struct r5dev *dev = &sh->dev[i];
2405 if (!test_bit(R5_OVERWRITE, &dev->flags)
2406 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2407 && !test_bit(R5_LOCKED, &dev->flags) &&
2408 !test_bit(R5_UPTODATE, &dev->flags) &&
2409 test_bit(R5_Insync, &dev->flags)) {
2410 if (
2411 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002412 pr_debug("Read_old stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002413 "block %d for Reconstruct\n",
2414 (unsigned long long)sh->sector, i);
2415 set_bit(R5_LOCKED, &dev->flags);
2416 set_bit(R5_Wantread, &dev->flags);
2417 s->locked++;
2418 } else {
Dan Williams45b42332007-07-09 11:56:43 -07002419 pr_debug("Request delayed stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002420 "block %d for Reconstruct\n",
2421 (unsigned long long)sh->sector, i);
2422 set_bit(STRIPE_DELAYED, &sh->state);
2423 set_bit(STRIPE_HANDLE, &sh->state);
2424 }
2425 }
2426 }
2427 /* now if nothing is locked, and if we have enough data, we can start a
2428 * write request
2429 */
2430 if (s->locked == 0 && rcw == 0 &&
2431 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2432 if (must_compute > 0) {
2433 /* We have failed blocks and need to compute them */
2434 switch (s->failed) {
2435 case 0:
2436 BUG();
2437 case 1:
2438 compute_block_1(sh, r6s->failed_num[0], 0);
2439 break;
2440 case 2:
2441 compute_block_2(sh, r6s->failed_num[0],
2442 r6s->failed_num[1]);
2443 break;
2444 default: /* This request should have been failed? */
2445 BUG();
2446 }
2447 }
2448
Dan Williams45b42332007-07-09 11:56:43 -07002449 pr_debug("Computing parity for stripe %llu\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002450 (unsigned long long)sh->sector);
2451 compute_parity6(sh, RECONSTRUCT_WRITE);
2452 /* now every locked buffer is ready to be written */
2453 for (i = disks; i--; )
2454 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
Dan Williams45b42332007-07-09 11:56:43 -07002455 pr_debug("Writing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002456 (unsigned long long)sh->sector, i);
2457 s->locked++;
2458 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2459 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002460 if (s->locked == disks)
2461 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2462 atomic_inc(&conf->pending_full_writes);
Dan Williamsa4456852007-07-09 11:56:43 -07002463 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2464 set_bit(STRIPE_INSYNC, &sh->state);
2465
2466 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2467 atomic_dec(&conf->preread_active_stripes);
2468 if (atomic_read(&conf->preread_active_stripes) <
2469 IO_THRESHOLD)
2470 md_wakeup_thread(conf->mddev->thread);
2471 }
2472 }
2473}
2474
2475static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2476 struct stripe_head_state *s, int disks)
2477{
Dan Williamsecc65c92008-06-28 08:31:57 +10002478 struct r5dev *dev = NULL;
Dan Williamse89f8962007-01-02 13:52:31 -07002479
Dan Williamsbd2ab672008-04-10 21:29:27 -07002480 set_bit(STRIPE_HANDLE, &sh->state);
2481
Dan Williamsecc65c92008-06-28 08:31:57 +10002482 switch (sh->check_state) {
2483 case check_state_idle:
2484 /* start a new check operation if there are no failures */
Dan Williamsbd2ab672008-04-10 21:29:27 -07002485 if (s->failed == 0) {
Dan Williamsbd2ab672008-04-10 21:29:27 -07002486 BUG_ON(s->uptodate != disks);
Dan Williamsecc65c92008-06-28 08:31:57 +10002487 sh->check_state = check_state_run;
2488 set_bit(STRIPE_OP_CHECK, &s->ops_request);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002489 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002490 s->uptodate--;
Dan Williamsecc65c92008-06-28 08:31:57 +10002491 break;
Dan Williamsbd2ab672008-04-10 21:29:27 -07002492 }
Dan Williamsa4456852007-07-09 11:56:43 -07002493 dev = &sh->dev[s->failed_num];
Dan Williamsecc65c92008-06-28 08:31:57 +10002494 /* fall through */
2495 case check_state_compute_result:
2496 sh->check_state = check_state_idle;
2497 if (!dev)
2498 dev = &sh->dev[sh->pd_idx];
2499
2500 /* check that a write has not made the stripe insync */
2501 if (test_bit(STRIPE_INSYNC, &sh->state))
2502 break;
2503
2504 /* either failed parity check, or recovery is happening */
Dan Williamsa4456852007-07-09 11:56:43 -07002505 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2506 BUG_ON(s->uptodate != disks);
2507
2508 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsecc65c92008-06-28 08:31:57 +10002509 s->locked++;
Dan Williamsa4456852007-07-09 11:56:43 -07002510 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002511
Dan Williamsa4456852007-07-09 11:56:43 -07002512 clear_bit(STRIPE_DEGRADED, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002513 set_bit(STRIPE_INSYNC, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002514 break;
2515 case check_state_run:
2516 break; /* we will be called again upon completion */
2517 case check_state_check_result:
2518 sh->check_state = check_state_idle;
2519
2520 /* if a failure occurred during the check operation, leave
2521 * STRIPE_INSYNC not set and let the stripe be handled again
2522 */
2523 if (s->failed)
2524 break;
2525
2526 /* handle a successful check operation, if parity is correct
2527 * we are done. Otherwise update the mismatch count and repair
2528 * parity if !MD_RECOVERY_CHECK
2529 */
2530 if (sh->ops.zero_sum_result == 0)
2531 /* parity is correct (on disc,
2532 * not in buffer any more)
2533 */
2534 set_bit(STRIPE_INSYNC, &sh->state);
2535 else {
2536 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2537 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2538 /* don't try to repair!! */
2539 set_bit(STRIPE_INSYNC, &sh->state);
2540 else {
2541 sh->check_state = check_state_compute_run;
Dan Williams976ea8d2008-06-28 08:32:03 +10002542 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002543 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2544 set_bit(R5_Wantcompute,
2545 &sh->dev[sh->pd_idx].flags);
2546 sh->ops.target = sh->pd_idx;
2547 s->uptodate++;
2548 }
2549 }
2550 break;
2551 case check_state_compute_run:
2552 break;
2553 default:
2554 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2555 __func__, sh->check_state,
2556 (unsigned long long) sh->sector);
2557 BUG();
Dan Williamsa4456852007-07-09 11:56:43 -07002558 }
2559}
2560
2561
2562static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2563 struct stripe_head_state *s,
2564 struct r6_state *r6s, struct page *tmp_page,
2565 int disks)
2566{
2567 int update_p = 0, update_q = 0;
2568 struct r5dev *dev;
2569 int pd_idx = sh->pd_idx;
NeilBrown34e04e82009-03-31 15:10:16 +11002570 int qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07002571
2572 set_bit(STRIPE_HANDLE, &sh->state);
2573
2574 BUG_ON(s->failed > 2);
2575 BUG_ON(s->uptodate < disks);
2576 /* Want to check and possibly repair P and Q.
2577 * However there could be one 'failed' device, in which
2578 * case we can only check one of them, possibly using the
2579 * other to generate missing data
2580 */
2581
2582 /* If !tmp_page, we cannot do the calculations,
2583 * but as we have set STRIPE_HANDLE, we will soon be called
2584 * by stripe_handle with a tmp_page - just wait until then.
2585 */
2586 if (tmp_page) {
2587 if (s->failed == r6s->q_failed) {
2588 /* The only possible failed device holds 'Q', so it
2589 * makes sense to check P (If anything else were failed,
2590 * we would have used P to recreate it).
2591 */
2592 compute_block_1(sh, pd_idx, 1);
2593 if (!page_is_zero(sh->dev[pd_idx].page)) {
2594 compute_block_1(sh, pd_idx, 0);
2595 update_p = 1;
2596 }
2597 }
2598 if (!r6s->q_failed && s->failed < 2) {
2599 /* q is not failed, and we didn't use it to generate
2600 * anything, so it makes sense to check it
2601 */
2602 memcpy(page_address(tmp_page),
2603 page_address(sh->dev[qd_idx].page),
2604 STRIPE_SIZE);
2605 compute_parity6(sh, UPDATE_PARITY);
2606 if (memcmp(page_address(tmp_page),
2607 page_address(sh->dev[qd_idx].page),
2608 STRIPE_SIZE) != 0) {
2609 clear_bit(STRIPE_INSYNC, &sh->state);
2610 update_q = 1;
2611 }
2612 }
2613 if (update_p || update_q) {
2614 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2615 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2616 /* don't try to repair!! */
2617 update_p = update_q = 0;
2618 }
2619
2620 /* now write out any block on a failed drive,
2621 * or P or Q if they need it
2622 */
2623
2624 if (s->failed == 2) {
2625 dev = &sh->dev[r6s->failed_num[1]];
2626 s->locked++;
2627 set_bit(R5_LOCKED, &dev->flags);
2628 set_bit(R5_Wantwrite, &dev->flags);
2629 }
2630 if (s->failed >= 1) {
2631 dev = &sh->dev[r6s->failed_num[0]];
2632 s->locked++;
2633 set_bit(R5_LOCKED, &dev->flags);
2634 set_bit(R5_Wantwrite, &dev->flags);
2635 }
2636
2637 if (update_p) {
2638 dev = &sh->dev[pd_idx];
2639 s->locked++;
2640 set_bit(R5_LOCKED, &dev->flags);
2641 set_bit(R5_Wantwrite, &dev->flags);
2642 }
2643 if (update_q) {
2644 dev = &sh->dev[qd_idx];
2645 s->locked++;
2646 set_bit(R5_LOCKED, &dev->flags);
2647 set_bit(R5_Wantwrite, &dev->flags);
2648 }
2649 clear_bit(STRIPE_DEGRADED, &sh->state);
2650
2651 set_bit(STRIPE_INSYNC, &sh->state);
2652 }
2653}
2654
2655static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2656 struct r6_state *r6s)
2657{
2658 int i;
2659
2660 /* We have read all the blocks in this stripe and now we need to
2661 * copy some of them into a target stripe for expand.
2662 */
Dan Williamsf0a50d32007-01-02 13:52:31 -07002663 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsa4456852007-07-09 11:56:43 -07002664 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2665 for (i = 0; i < sh->disks; i++)
NeilBrown34e04e82009-03-31 15:10:16 +11002666 if (i != sh->pd_idx && i != sh->qd_idx) {
NeilBrown911d4ee2009-03-31 14:39:38 +11002667 int dd_idx, j;
Dan Williamsa4456852007-07-09 11:56:43 -07002668 struct stripe_head *sh2;
2669
NeilBrown784052e2009-03-31 15:19:07 +11002670 sector_t bn = compute_blocknr(sh, i, 1);
NeilBrown911d4ee2009-03-31 14:39:38 +11002671 sector_t s = raid5_compute_sector(conf, bn, 0,
2672 &dd_idx, NULL);
NeilBrowna8c906c2009-06-09 14:39:59 +10002673 sh2 = get_active_stripe(conf, s, 0, 1, 1);
Dan Williamsa4456852007-07-09 11:56:43 -07002674 if (sh2 == NULL)
2675 /* so far only the early blocks of this stripe
2676 * have been requested. When later blocks
2677 * get requested, we will try again
2678 */
2679 continue;
2680 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2681 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2682 /* must have already done this block */
2683 release_stripe(sh2);
2684 continue;
2685 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002686
2687 /* place all the copies on one channel */
2688 tx = async_memcpy(sh2->dev[dd_idx].page,
2689 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2690 ASYNC_TX_DEP_ACK, tx, NULL, NULL);
2691
Dan Williamsa4456852007-07-09 11:56:43 -07002692 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2693 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2694 for (j = 0; j < conf->raid_disks; j++)
2695 if (j != sh2->pd_idx &&
NeilBrownd0dabf72009-03-31 14:39:38 +11002696 (!r6s || j != sh2->qd_idx) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002697 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2698 break;
2699 if (j == conf->raid_disks) {
2700 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2701 set_bit(STRIPE_HANDLE, &sh2->state);
2702 }
2703 release_stripe(sh2);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002704
Dan Williamsa4456852007-07-09 11:56:43 -07002705 }
NeilBrowna2e08552007-09-11 15:23:36 -07002706 /* done submitting copies, wait for them to complete */
2707 if (tx) {
2708 async_tx_ack(tx);
2709 dma_wait_for_async_tx(tx);
2710 }
Dan Williamsa4456852007-07-09 11:56:43 -07002711}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002712
Dan Williams6bfe0b42008-04-30 00:52:32 -07002713
Linus Torvalds1da177e2005-04-16 15:20:36 -07002714/*
2715 * handle_stripe - do things to a stripe.
2716 *
2717 * We lock the stripe and then examine the state of various bits
2718 * to see what needs to be done.
2719 * Possible results:
2720 * return some read request which now have data
2721 * return some write requests which are safely on disc
2722 * schedule a read on some buffers
2723 * schedule a write of some buffers
2724 * return confirmation of parity correctness
2725 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726 * buffers are taken off read_list or write_list, and bh_cache buffers
2727 * get BH_Lock set before the stripe lock is released.
2728 *
2729 */
Dan Williamsa4456852007-07-09 11:56:43 -07002730
Dan Williamsdf10cfb2008-07-28 23:10:39 -07002731static bool handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002732{
2733 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa4456852007-07-09 11:56:43 -07002734 int disks = sh->disks, i;
2735 struct bio *return_bi = NULL;
2736 struct stripe_head_state s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002737 struct r5dev *dev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002738 mdk_rdev_t *blocked_rdev = NULL;
Dan Williamse0a115e2008-06-05 22:45:52 -07002739 int prexor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002740
Dan Williamsa4456852007-07-09 11:56:43 -07002741 memset(&s, 0, sizeof(s));
Dan Williams600aa102008-06-28 08:32:05 +10002742 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2743 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
2744 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
2745 sh->reconstruct_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002746
2747 spin_lock(&sh->lock);
2748 clear_bit(STRIPE_HANDLE, &sh->state);
2749 clear_bit(STRIPE_DELAYED, &sh->state);
2750
Dan Williamsa4456852007-07-09 11:56:43 -07002751 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2752 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2753 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Dan Williams83de75c2008-06-28 08:31:58 +10002754
Linus Torvalds1da177e2005-04-16 15:20:36 -07002755 /* Now to look around and see what can be done */
NeilBrown9910f162006-01-06 00:20:24 -08002756 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002757 for (i=disks; i--; ) {
2758 mdk_rdev_t *rdev;
Dan Williamsa4456852007-07-09 11:56:43 -07002759 struct r5dev *dev = &sh->dev[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002760 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002761
Dan Williamsb5e98d62007-01-02 13:52:31 -07002762 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2763 "written %p\n", i, dev->flags, dev->toread, dev->read,
2764 dev->towrite, dev->written);
2765
2766 /* maybe we can request a biofill operation
2767 *
2768 * new wantfill requests are only permitted while
Dan Williams83de75c2008-06-28 08:31:58 +10002769 * ops_complete_biofill is guaranteed to be inactive
Dan Williamsb5e98d62007-01-02 13:52:31 -07002770 */
2771 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
Dan Williams83de75c2008-06-28 08:31:58 +10002772 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
Dan Williamsb5e98d62007-01-02 13:52:31 -07002773 set_bit(R5_Wantfill, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002774
2775 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002776 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2777 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williamsf38e1212007-01-02 13:52:30 -07002778 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002779
Dan Williamsb5e98d62007-01-02 13:52:31 -07002780 if (test_bit(R5_Wantfill, &dev->flags))
2781 s.to_fill++;
2782 else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07002783 s.to_read++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002784 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002785 s.to_write++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002786 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002787 s.non_overwrite++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002788 }
Dan Williamsa4456852007-07-09 11:56:43 -07002789 if (dev->written)
2790 s.written++;
NeilBrown9910f162006-01-06 00:20:24 -08002791 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10002792 if (blocked_rdev == NULL &&
2793 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07002794 blocked_rdev = rdev;
2795 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07002796 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002797 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08002798 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08002799 clear_bit(R5_ReadError, &dev->flags);
2800 clear_bit(R5_ReWrite, &dev->flags);
2801 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002802 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002803 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002804 s.failed++;
2805 s.failed_num = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002806 } else
2807 set_bit(R5_Insync, &dev->flags);
2808 }
NeilBrown9910f162006-01-06 00:20:24 -08002809 rcu_read_unlock();
Dan Williamsb5e98d62007-01-02 13:52:31 -07002810
Dan Williams6bfe0b42008-04-30 00:52:32 -07002811 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10002812 if (s.syncing || s.expanding || s.expanded ||
2813 s.to_write || s.written) {
2814 set_bit(STRIPE_HANDLE, &sh->state);
2815 goto unlock;
2816 }
2817 /* There is nothing for the blocked_rdev to block */
2818 rdev_dec_pending(blocked_rdev, conf->mddev);
2819 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002820 }
2821
Dan Williams83de75c2008-06-28 08:31:58 +10002822 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
2823 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
2824 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
2825 }
Dan Williamsb5e98d62007-01-02 13:52:31 -07002826
Dan Williams45b42332007-07-09 11:56:43 -07002827 pr_debug("locked=%d uptodate=%d to_read=%d"
Linus Torvalds1da177e2005-04-16 15:20:36 -07002828 " to_write=%d failed=%d failed_num=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002829 s.locked, s.uptodate, s.to_read, s.to_write,
2830 s.failed, s.failed_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002831 /* check if the array has lost two devices and, if so, some requests might
2832 * need to be failed
2833 */
Dan Williamsa4456852007-07-09 11:56:43 -07002834 if (s.failed > 1 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10002835 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07002836 if (s.failed > 1 && s.syncing) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002837 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2838 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002839 s.syncing = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002840 }
2841
2842 /* might be able to return some write requests if the parity block
2843 * is safe, or on a failed drive
2844 */
2845 dev = &sh->dev[sh->pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07002846 if ( s.written &&
2847 ((test_bit(R5_Insync, &dev->flags) &&
2848 !test_bit(R5_LOCKED, &dev->flags) &&
2849 test_bit(R5_UPTODATE, &dev->flags)) ||
2850 (s.failed == 1 && s.failed_num == sh->pd_idx)))
Dan Williams1fe797e2008-06-28 09:16:30 +10002851 handle_stripe_clean_event(conf, sh, disks, &return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002852
2853 /* Now we might consider reading some blocks, either to check/generate
2854 * parity, or to satisfy requests
2855 * or to load a block that is being partially written.
2856 */
Dan Williamsa4456852007-07-09 11:56:43 -07002857 if (s.to_read || s.non_overwrite ||
Dan Williams976ea8d2008-06-28 08:32:03 +10002858 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10002859 handle_stripe_fill5(sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002860
Dan Williamse33129d2007-01-02 13:52:30 -07002861 /* Now we check to see if any write operations have recently
2862 * completed
2863 */
Dan Williamse0a115e2008-06-05 22:45:52 -07002864 prexor = 0;
Dan Williamsd8ee0722008-06-28 08:32:06 +10002865 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
Dan Williamse0a115e2008-06-05 22:45:52 -07002866 prexor = 1;
Dan Williamsd8ee0722008-06-28 08:32:06 +10002867 if (sh->reconstruct_state == reconstruct_state_drain_result ||
2868 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
Dan Williams600aa102008-06-28 08:32:05 +10002869 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamse33129d2007-01-02 13:52:30 -07002870
2871 /* All the 'written' buffers and the parity block are ready to
2872 * be written back to disk
2873 */
2874 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
2875 for (i = disks; i--; ) {
2876 dev = &sh->dev[i];
2877 if (test_bit(R5_LOCKED, &dev->flags) &&
2878 (i == sh->pd_idx || dev->written)) {
2879 pr_debug("Writing block %d\n", i);
2880 set_bit(R5_Wantwrite, &dev->flags);
Dan Williamse0a115e2008-06-05 22:45:52 -07002881 if (prexor)
2882 continue;
Dan Williamse33129d2007-01-02 13:52:30 -07002883 if (!test_bit(R5_Insync, &dev->flags) ||
2884 (i == sh->pd_idx && s.failed == 0))
2885 set_bit(STRIPE_INSYNC, &sh->state);
2886 }
2887 }
2888 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2889 atomic_dec(&conf->preread_active_stripes);
2890 if (atomic_read(&conf->preread_active_stripes) <
2891 IO_THRESHOLD)
2892 md_wakeup_thread(conf->mddev->thread);
2893 }
2894 }
2895
2896 /* Now to consider new write requests and what else, if anything
2897 * should be read. We do not handle new writes when:
2898 * 1/ A 'write' operation (copy+xor) is already in flight.
2899 * 2/ A 'check' operation is in flight, as it may clobber the parity
2900 * block.
2901 */
Dan Williams600aa102008-06-28 08:32:05 +10002902 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
Dan Williams1fe797e2008-06-28 09:16:30 +10002903 handle_stripe_dirtying5(conf, sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002904
2905 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamse89f8962007-01-02 13:52:31 -07002906 * Any reads will already have been scheduled, so we just see if enough
2907 * data is available. The parity check is held off while parity
2908 * dependent operations are in flight.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002909 */
Dan Williamsecc65c92008-06-28 08:31:57 +10002910 if (sh->check_state ||
2911 (s.syncing && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10002912 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10002913 !test_bit(STRIPE_INSYNC, &sh->state)))
Dan Williamsa4456852007-07-09 11:56:43 -07002914 handle_parity_checks5(conf, sh, &s, disks);
Dan Williamse89f8962007-01-02 13:52:31 -07002915
Dan Williamsa4456852007-07-09 11:56:43 -07002916 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002917 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2918 clear_bit(STRIPE_SYNCING, &sh->state);
2919 }
NeilBrown4e5314b2005-11-08 21:39:22 -08002920
2921 /* If the failed drive is just a ReadError, then we might need to progress
2922 * the repair/check process
2923 */
Dan Williamsa4456852007-07-09 11:56:43 -07002924 if (s.failed == 1 && !conf->mddev->ro &&
2925 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2926 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2927 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002928 ) {
Dan Williamsa4456852007-07-09 11:56:43 -07002929 dev = &sh->dev[s.failed_num];
NeilBrown4e5314b2005-11-08 21:39:22 -08002930 if (!test_bit(R5_ReWrite, &dev->flags)) {
2931 set_bit(R5_Wantwrite, &dev->flags);
2932 set_bit(R5_ReWrite, &dev->flags);
2933 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002934 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002935 } else {
2936 /* let's read it back */
2937 set_bit(R5_Wantread, &dev->flags);
2938 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002939 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002940 }
2941 }
2942
Dan Williams600aa102008-06-28 08:32:05 +10002943 /* Finish reconstruct operations initiated by the expansion process */
2944 if (sh->reconstruct_state == reconstruct_state_result) {
NeilBrownab69ae12009-03-31 15:26:47 +11002945 struct stripe_head *sh2
NeilBrowna8c906c2009-06-09 14:39:59 +10002946 = get_active_stripe(conf, sh->sector, 1, 1, 1);
NeilBrownab69ae12009-03-31 15:26:47 +11002947 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
2948 /* sh cannot be written until sh2 has been read.
2949 * so arrange for sh to be delayed a little
2950 */
2951 set_bit(STRIPE_DELAYED, &sh->state);
2952 set_bit(STRIPE_HANDLE, &sh->state);
2953 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
2954 &sh2->state))
2955 atomic_inc(&conf->preread_active_stripes);
2956 release_stripe(sh2);
2957 goto unlock;
2958 }
2959 if (sh2)
2960 release_stripe(sh2);
2961
Dan Williams600aa102008-06-28 08:32:05 +10002962 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamsf0a50d32007-01-02 13:52:31 -07002963 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williams23397882008-07-23 20:05:34 -07002964 for (i = conf->raid_disks; i--; ) {
Dan Williamsf0a50d32007-01-02 13:52:31 -07002965 set_bit(R5_Wantwrite, &sh->dev[i].flags);
Dan Williams23397882008-07-23 20:05:34 -07002966 set_bit(R5_LOCKED, &sh->dev[i].flags);
Neil Brownefe31142008-06-28 08:31:14 +10002967 s.locked++;
Dan Williams23397882008-07-23 20:05:34 -07002968 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002969 }
2970
2971 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
Dan Williams600aa102008-06-28 08:32:05 +10002972 !sh->reconstruct_state) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002973 /* Need to write out all blocks after computing parity */
2974 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11002975 stripe_set_idx(sh->sector, conf, 0, sh);
Dan Williams1fe797e2008-06-28 09:16:30 +10002976 schedule_reconstruction5(sh, &s, 1, 1);
Dan Williams600aa102008-06-28 08:32:05 +10002977 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002978 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08002979 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002980 wake_up(&conf->wait_for_overlap);
2981 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2982 }
2983
Dan Williams0f94e872008-01-08 15:32:53 -08002984 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10002985 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07002986 handle_stripe_expansion(conf, sh, NULL);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002987
Dan Williams6bfe0b42008-04-30 00:52:32 -07002988 unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002989 spin_unlock(&sh->lock);
2990
Dan Williams6bfe0b42008-04-30 00:52:32 -07002991 /* wait for this device to become unblocked */
2992 if (unlikely(blocked_rdev))
2993 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
2994
Dan Williams600aa102008-06-28 08:32:05 +10002995 if (s.ops_request)
2996 raid5_run_ops(sh, s.ops_request);
Dan Williamsd84e0f12007-01-02 13:52:30 -07002997
Dan Williamsc4e5ac02008-06-28 08:31:53 +10002998 ops_run_io(sh, &s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002999
Dan Williamsa4456852007-07-09 11:56:43 -07003000 return_io(return_bi);
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003001
3002 return blocked_rdev == NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003}
3004
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003005static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
NeilBrown16a53ec2006-06-26 00:27:38 -07003006{
NeilBrownbff61972009-03-31 14:33:13 +11003007 raid5_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08003008 int disks = sh->disks;
Dan Williamsa4456852007-07-09 11:56:43 -07003009 struct bio *return_bi = NULL;
NeilBrown34e04e82009-03-31 15:10:16 +11003010 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07003011 struct stripe_head_state s;
3012 struct r6_state r6s;
NeilBrown16a53ec2006-06-26 00:27:38 -07003013 struct r5dev *dev, *pdev, *qdev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003014 mdk_rdev_t *blocked_rdev = NULL;
NeilBrown16a53ec2006-06-26 00:27:38 -07003015
Dan Williams45b42332007-07-09 11:56:43 -07003016 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
Dan Williamsa4456852007-07-09 11:56:43 -07003017 "pd_idx=%d, qd_idx=%d\n",
3018 (unsigned long long)sh->sector, sh->state,
NeilBrown34e04e82009-03-31 15:10:16 +11003019 atomic_read(&sh->count), pd_idx, qd_idx);
Dan Williamsa4456852007-07-09 11:56:43 -07003020 memset(&s, 0, sizeof(s));
NeilBrown16a53ec2006-06-26 00:27:38 -07003021
3022 spin_lock(&sh->lock);
3023 clear_bit(STRIPE_HANDLE, &sh->state);
3024 clear_bit(STRIPE_DELAYED, &sh->state);
3025
Dan Williamsa4456852007-07-09 11:56:43 -07003026 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3027 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3028 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrown16a53ec2006-06-26 00:27:38 -07003029 /* Now to look around and see what can be done */
3030
3031 rcu_read_lock();
3032 for (i=disks; i--; ) {
3033 mdk_rdev_t *rdev;
3034 dev = &sh->dev[i];
3035 clear_bit(R5_Insync, &dev->flags);
3036
Dan Williams45b42332007-07-09 11:56:43 -07003037 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003038 i, dev->flags, dev->toread, dev->towrite, dev->written);
3039 /* maybe we can reply to a read */
3040 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
3041 struct bio *rbi, *rbi2;
Dan Williams45b42332007-07-09 11:56:43 -07003042 pr_debug("Return read for disc %d\n", i);
NeilBrown16a53ec2006-06-26 00:27:38 -07003043 spin_lock_irq(&conf->device_lock);
3044 rbi = dev->toread;
3045 dev->toread = NULL;
3046 if (test_and_clear_bit(R5_Overlap, &dev->flags))
3047 wake_up(&conf->wait_for_overlap);
3048 spin_unlock_irq(&conf->device_lock);
3049 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
3050 copy_data(0, rbi, dev->page, dev->sector);
3051 rbi2 = r5_next_bio(rbi, dev->sector);
3052 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02003053 if (!raid5_dec_bi_phys_segments(rbi)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003054 rbi->bi_next = return_bi;
3055 return_bi = rbi;
3056 }
3057 spin_unlock_irq(&conf->device_lock);
3058 rbi = rbi2;
3059 }
3060 }
3061
3062 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07003063 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3064 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003065
3066
Dan Williamsa4456852007-07-09 11:56:43 -07003067 if (dev->toread)
3068 s.to_read++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003069 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07003070 s.to_write++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003071 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07003072 s.non_overwrite++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003073 }
Dan Williamsa4456852007-07-09 11:56:43 -07003074 if (dev->written)
3075 s.written++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003076 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10003077 if (blocked_rdev == NULL &&
3078 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07003079 blocked_rdev = rdev;
3080 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07003081 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003082 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
3083 /* The ReadError flag will just be confusing now */
3084 clear_bit(R5_ReadError, &dev->flags);
3085 clear_bit(R5_ReWrite, &dev->flags);
3086 }
3087 if (!rdev || !test_bit(In_sync, &rdev->flags)
3088 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07003089 if (s.failed < 2)
3090 r6s.failed_num[s.failed] = i;
3091 s.failed++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003092 } else
3093 set_bit(R5_Insync, &dev->flags);
3094 }
3095 rcu_read_unlock();
Dan Williams6bfe0b42008-04-30 00:52:32 -07003096
3097 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10003098 if (s.syncing || s.expanding || s.expanded ||
3099 s.to_write || s.written) {
3100 set_bit(STRIPE_HANDLE, &sh->state);
3101 goto unlock;
3102 }
3103 /* There is nothing for the blocked_rdev to block */
3104 rdev_dec_pending(blocked_rdev, conf->mddev);
3105 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003106 }
NeilBrownac4090d2008-08-05 15:54:13 +10003107
Dan Williams45b42332007-07-09 11:56:43 -07003108 pr_debug("locked=%d uptodate=%d to_read=%d"
NeilBrown16a53ec2006-06-26 00:27:38 -07003109 " to_write=%d failed=%d failed_num=%d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003110 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3111 r6s.failed_num[0], r6s.failed_num[1]);
3112 /* check if the array has lost >2 devices and, if so, some requests
3113 * might need to be failed
NeilBrown16a53ec2006-06-26 00:27:38 -07003114 */
Dan Williamsa4456852007-07-09 11:56:43 -07003115 if (s.failed > 2 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10003116 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07003117 if (s.failed > 2 && s.syncing) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003118 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3119 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003120 s.syncing = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07003121 }
3122
3123 /*
3124 * might be able to return some write requests if the parity blocks
3125 * are safe, or on a failed drive
3126 */
3127 pdev = &sh->dev[pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07003128 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3129 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
NeilBrown34e04e82009-03-31 15:10:16 +11003130 qdev = &sh->dev[qd_idx];
3131 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3132 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
NeilBrown16a53ec2006-06-26 00:27:38 -07003133
Dan Williamsa4456852007-07-09 11:56:43 -07003134 if ( s.written &&
3135 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003136 && !test_bit(R5_LOCKED, &pdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003137 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3138 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003139 && !test_bit(R5_LOCKED, &qdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003140 && test_bit(R5_UPTODATE, &qdev->flags)))))
Dan Williams1fe797e2008-06-28 09:16:30 +10003141 handle_stripe_clean_event(conf, sh, disks, &return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003142
3143 /* Now we might consider reading some blocks, either to check/generate
3144 * parity, or to satisfy requests
3145 * or to load a block that is being partially written.
3146 */
Dan Williamsa4456852007-07-09 11:56:43 -07003147 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3148 (s.syncing && (s.uptodate < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10003149 handle_stripe_fill6(sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003150
3151 /* now to consider writing and what else, if anything should be read */
Dan Williamsa4456852007-07-09 11:56:43 -07003152 if (s.to_write)
Dan Williams1fe797e2008-06-28 09:16:30 +10003153 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003154
3155 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamsa4456852007-07-09 11:56:43 -07003156 * Any reads will already have been scheduled, so we just see if enough
3157 * data is available
NeilBrown16a53ec2006-06-26 00:27:38 -07003158 */
Dan Williamsa4456852007-07-09 11:56:43 -07003159 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
3160 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003161
Dan Williamsa4456852007-07-09 11:56:43 -07003162 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003163 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3164 clear_bit(STRIPE_SYNCING, &sh->state);
3165 }
3166
3167 /* If the failed drives are just a ReadError, then we might need
3168 * to progress the repair/check process
3169 */
Dan Williamsa4456852007-07-09 11:56:43 -07003170 if (s.failed <= 2 && !conf->mddev->ro)
3171 for (i = 0; i < s.failed; i++) {
3172 dev = &sh->dev[r6s.failed_num[i]];
NeilBrown16a53ec2006-06-26 00:27:38 -07003173 if (test_bit(R5_ReadError, &dev->flags)
3174 && !test_bit(R5_LOCKED, &dev->flags)
3175 && test_bit(R5_UPTODATE, &dev->flags)
3176 ) {
3177 if (!test_bit(R5_ReWrite, &dev->flags)) {
3178 set_bit(R5_Wantwrite, &dev->flags);
3179 set_bit(R5_ReWrite, &dev->flags);
3180 set_bit(R5_LOCKED, &dev->flags);
3181 } else {
3182 /* let's read it back */
3183 set_bit(R5_Wantread, &dev->flags);
3184 set_bit(R5_LOCKED, &dev->flags);
3185 }
3186 }
3187 }
NeilBrownf4168852007-02-28 20:11:53 -08003188
Dan Williamsa4456852007-07-09 11:56:43 -07003189 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
NeilBrownab69ae12009-03-31 15:26:47 +11003190 struct stripe_head *sh2
NeilBrowna8c906c2009-06-09 14:39:59 +10003191 = get_active_stripe(conf, sh->sector, 1, 1, 1);
NeilBrownab69ae12009-03-31 15:26:47 +11003192 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3193 /* sh cannot be written until sh2 has been read.
3194 * so arrange for sh to be delayed a little
3195 */
3196 set_bit(STRIPE_DELAYED, &sh->state);
3197 set_bit(STRIPE_HANDLE, &sh->state);
3198 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3199 &sh2->state))
3200 atomic_inc(&conf->preread_active_stripes);
3201 release_stripe(sh2);
3202 goto unlock;
3203 }
3204 if (sh2)
3205 release_stripe(sh2);
3206
NeilBrownf4168852007-02-28 20:11:53 -08003207 /* Need to write out all blocks after computing P&Q */
3208 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11003209 stripe_set_idx(sh->sector, conf, 0, sh);
NeilBrownf4168852007-02-28 20:11:53 -08003210 compute_parity6(sh, RECONSTRUCT_WRITE);
3211 for (i = conf->raid_disks ; i-- ; ) {
3212 set_bit(R5_LOCKED, &sh->dev[i].flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003213 s.locked++;
NeilBrownf4168852007-02-28 20:11:53 -08003214 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3215 }
3216 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003217 } else if (s.expanded) {
NeilBrownf4168852007-02-28 20:11:53 -08003218 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3219 atomic_dec(&conf->reshape_stripes);
3220 wake_up(&conf->wait_for_overlap);
3221 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3222 }
3223
Dan Williams0f94e872008-01-08 15:32:53 -08003224 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10003225 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07003226 handle_stripe_expansion(conf, sh, &r6s);
NeilBrownf4168852007-02-28 20:11:53 -08003227
Dan Williams6bfe0b42008-04-30 00:52:32 -07003228 unlock:
NeilBrown16a53ec2006-06-26 00:27:38 -07003229 spin_unlock(&sh->lock);
3230
Dan Williams6bfe0b42008-04-30 00:52:32 -07003231 /* wait for this device to become unblocked */
3232 if (unlikely(blocked_rdev))
3233 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3234
Dan Williamsf0e43bc2008-06-28 08:31:55 +10003235 ops_run_io(sh, &s);
3236
Dan Williamsa4456852007-07-09 11:56:43 -07003237 return_io(return_bi);
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003238
3239 return blocked_rdev == NULL;
NeilBrown16a53ec2006-06-26 00:27:38 -07003240}
3241
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003242/* returns true if the stripe was handled */
3243static bool handle_stripe(struct stripe_head *sh, struct page *tmp_page)
NeilBrown16a53ec2006-06-26 00:27:38 -07003244{
3245 if (sh->raid_conf->level == 6)
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003246 return handle_stripe6(sh, tmp_page);
NeilBrown16a53ec2006-06-26 00:27:38 -07003247 else
Dan Williamsdf10cfb2008-07-28 23:10:39 -07003248 return handle_stripe5(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -07003249}
3250
3251
3252
Arjan van de Ven858119e2006-01-14 13:20:43 -08003253static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003254{
3255 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3256 while (!list_empty(&conf->delayed_list)) {
3257 struct list_head *l = conf->delayed_list.next;
3258 struct stripe_head *sh;
3259 sh = list_entry(l, struct stripe_head, lru);
3260 list_del_init(l);
3261 clear_bit(STRIPE_DELAYED, &sh->state);
3262 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3263 atomic_inc(&conf->preread_active_stripes);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003264 list_add_tail(&sh->lru, &conf->hold_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003265 }
NeilBrown6ed30032008-02-06 01:40:00 -08003266 } else
3267 blk_plug_device(conf->mddev->queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003268}
3269
Arjan van de Ven858119e2006-01-14 13:20:43 -08003270static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07003271{
3272 /* device_lock is held */
3273 struct list_head head;
3274 list_add(&head, &conf->bitmap_list);
3275 list_del_init(&conf->bitmap_list);
3276 while (!list_empty(&head)) {
3277 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3278 list_del_init(&sh->lru);
3279 atomic_inc(&sh->count);
3280 __release_stripe(conf, sh);
3281 }
3282}
3283
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284static void unplug_slaves(mddev_t *mddev)
3285{
NeilBrown070ec552009-06-16 16:54:21 +10003286 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003287 int i;
3288
3289 rcu_read_lock();
NeilBrownf001a702009-06-09 14:30:31 +10003290 for (i = 0; i < conf->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08003291 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08003292 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +02003293 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003294
3295 atomic_inc(&rdev->nr_pending);
3296 rcu_read_unlock();
3297
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -05003298 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003299
3300 rdev_dec_pending(rdev, mddev);
3301 rcu_read_lock();
3302 }
3303 }
3304 rcu_read_unlock();
3305}
3306
Jens Axboe165125e2007-07-24 09:28:11 +02003307static void raid5_unplug_device(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003308{
3309 mddev_t *mddev = q->queuedata;
NeilBrown070ec552009-06-16 16:54:21 +10003310 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003311 unsigned long flags;
3312
3313 spin_lock_irqsave(&conf->device_lock, flags);
3314
NeilBrown72626682005-09-09 16:23:54 -07003315 if (blk_remove_plug(q)) {
3316 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003317 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07003318 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003319 md_wakeup_thread(mddev->thread);
3320
3321 spin_unlock_irqrestore(&conf->device_lock, flags);
3322
3323 unplug_slaves(mddev);
3324}
3325
NeilBrownf022b2f2006-10-03 01:15:56 -07003326static int raid5_congested(void *data, int bits)
3327{
3328 mddev_t *mddev = data;
NeilBrown070ec552009-06-16 16:54:21 +10003329 raid5_conf_t *conf = mddev->private;
NeilBrownf022b2f2006-10-03 01:15:56 -07003330
3331 /* No difference between reads and writes. Just check
3332 * how busy the stripe_cache is
3333 */
3334 if (conf->inactive_blocked)
3335 return 1;
3336 if (conf->quiesce)
3337 return 1;
3338 if (list_empty_careful(&conf->inactive_list))
3339 return 1;
3340
3341 return 0;
3342}
3343
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003344/* We want read requests to align with chunks where possible,
3345 * but write requests don't need to.
3346 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003347static int raid5_mergeable_bvec(struct request_queue *q,
3348 struct bvec_merge_data *bvm,
3349 struct bio_vec *biovec)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003350{
3351 mddev_t *mddev = q->queuedata;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003352 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003353 int max;
Andre Noll9d8f0362009-06-18 08:45:01 +10003354 unsigned int chunk_sectors = mddev->chunk_sectors;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003355 unsigned int bio_sectors = bvm->bi_size >> 9;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003356
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003357 if ((bvm->bi_rw & 1) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003358 return biovec->bv_len; /* always allow writes to be mergeable */
3359
Andre Noll664e7c42009-06-18 08:45:27 +10003360 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3361 chunk_sectors = mddev->new_chunk_sectors;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003362 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3363 if (max < 0) max = 0;
3364 if (max <= biovec->bv_len && bio_sectors == 0)
3365 return biovec->bv_len;
3366 else
3367 return max;
3368}
3369
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003370
3371static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3372{
3373 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
Andre Noll9d8f0362009-06-18 08:45:01 +10003374 unsigned int chunk_sectors = mddev->chunk_sectors;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003375 unsigned int bio_sectors = bio->bi_size >> 9;
3376
Andre Noll664e7c42009-06-18 08:45:27 +10003377 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3378 chunk_sectors = mddev->new_chunk_sectors;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003379 return chunk_sectors >=
3380 ((sector & (chunk_sectors - 1)) + bio_sectors);
3381}
3382
3383/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003384 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3385 * later sampled by raid5d.
3386 */
3387static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3388{
3389 unsigned long flags;
3390
3391 spin_lock_irqsave(&conf->device_lock, flags);
3392
3393 bi->bi_next = conf->retry_read_aligned_list;
3394 conf->retry_read_aligned_list = bi;
3395
3396 spin_unlock_irqrestore(&conf->device_lock, flags);
3397 md_wakeup_thread(conf->mddev->thread);
3398}
3399
3400
3401static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3402{
3403 struct bio *bi;
3404
3405 bi = conf->retry_read_aligned;
3406 if (bi) {
3407 conf->retry_read_aligned = NULL;
3408 return bi;
3409 }
3410 bi = conf->retry_read_aligned_list;
3411 if(bi) {
Neil Brown387bb172007-02-08 14:20:29 -08003412 conf->retry_read_aligned_list = bi->bi_next;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003413 bi->bi_next = NULL;
Jens Axboe960e7392008-08-15 10:41:18 +02003414 /*
3415 * this sets the active strip count to 1 and the processed
3416 * strip count to zero (upper 8 bits)
3417 */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003418 bi->bi_phys_segments = 1; /* biased count of active stripes */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003419 }
3420
3421 return bi;
3422}
3423
3424
3425/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003426 * The "raid5_align_endio" should check if the read succeeded and if it
3427 * did, call bio_endio on the original bio (having bio_put the new bio
3428 * first).
3429 * If the read failed..
3430 */
NeilBrown6712ecf2007-09-27 12:47:43 +02003431static void raid5_align_endio(struct bio *bi, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003432{
3433 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003434 mddev_t *mddev;
3435 raid5_conf_t *conf;
3436 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3437 mdk_rdev_t *rdev;
3438
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003439 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003440
3441 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
NeilBrown070ec552009-06-16 16:54:21 +10003442 conf = mddev->private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003443 rdev = (void*)raid_bi->bi_next;
3444 raid_bi->bi_next = NULL;
3445
3446 rdev_dec_pending(rdev, conf->mddev);
3447
3448 if (!error && uptodate) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003449 bio_endio(raid_bi, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003450 if (atomic_dec_and_test(&conf->active_aligned_reads))
3451 wake_up(&conf->wait_for_stripe);
NeilBrown6712ecf2007-09-27 12:47:43 +02003452 return;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003453 }
3454
3455
Dan Williams45b42332007-07-09 11:56:43 -07003456 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003457
3458 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003459}
3460
Neil Brown387bb172007-02-08 14:20:29 -08003461static int bio_fits_rdev(struct bio *bi)
3462{
Jens Axboe165125e2007-07-24 09:28:11 +02003463 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
Neil Brown387bb172007-02-08 14:20:29 -08003464
Martin K. Petersenae03bf62009-05-22 17:17:50 -04003465 if ((bi->bi_size>>9) > queue_max_sectors(q))
Neil Brown387bb172007-02-08 14:20:29 -08003466 return 0;
3467 blk_recount_segments(q, bi);
Martin K. Petersenae03bf62009-05-22 17:17:50 -04003468 if (bi->bi_phys_segments > queue_max_phys_segments(q))
Neil Brown387bb172007-02-08 14:20:29 -08003469 return 0;
3470
3471 if (q->merge_bvec_fn)
3472 /* it's too hard to apply the merge_bvec_fn at this stage,
3473 * just just give up
3474 */
3475 return 0;
3476
3477 return 1;
3478}
3479
3480
Jens Axboe165125e2007-07-24 09:28:11 +02003481static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003482{
3483 mddev_t *mddev = q->queuedata;
NeilBrown070ec552009-06-16 16:54:21 +10003484 raid5_conf_t *conf = mddev->private;
NeilBrown911d4ee2009-03-31 14:39:38 +11003485 unsigned int dd_idx;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003486 struct bio* align_bi;
3487 mdk_rdev_t *rdev;
3488
3489 if (!in_chunk_boundary(mddev, raid_bio)) {
Dan Williams45b42332007-07-09 11:56:43 -07003490 pr_debug("chunk_aligned_read : non aligned\n");
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003491 return 0;
3492 }
3493 /*
NeilBrown99c0fb52009-03-31 14:39:38 +11003494 * use bio_clone to make a copy of the bio
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003495 */
3496 align_bi = bio_clone(raid_bio, GFP_NOIO);
3497 if (!align_bi)
3498 return 0;
3499 /*
3500 * set bi_end_io to a new function, and set bi_private to the
3501 * original bio.
3502 */
3503 align_bi->bi_end_io = raid5_align_endio;
3504 align_bi->bi_private = raid_bio;
3505 /*
3506 * compute position
3507 */
NeilBrown112bf892009-03-31 14:39:38 +11003508 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3509 0,
NeilBrown911d4ee2009-03-31 14:39:38 +11003510 &dd_idx, NULL);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003511
3512 rcu_read_lock();
3513 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3514 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003515 atomic_inc(&rdev->nr_pending);
3516 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003517 raid_bio->bi_next = (void*)rdev;
3518 align_bi->bi_bdev = rdev->bdev;
3519 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3520 align_bi->bi_sector += rdev->data_offset;
3521
Neil Brown387bb172007-02-08 14:20:29 -08003522 if (!bio_fits_rdev(align_bi)) {
3523 /* too big in some way */
3524 bio_put(align_bi);
3525 rdev_dec_pending(rdev, mddev);
3526 return 0;
3527 }
3528
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003529 spin_lock_irq(&conf->device_lock);
3530 wait_event_lock_irq(conf->wait_for_stripe,
3531 conf->quiesce == 0,
3532 conf->device_lock, /* nothing */);
3533 atomic_inc(&conf->active_aligned_reads);
3534 spin_unlock_irq(&conf->device_lock);
3535
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003536 generic_make_request(align_bi);
3537 return 1;
3538 } else {
3539 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003540 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003541 return 0;
3542 }
3543}
3544
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003545/* __get_priority_stripe - get the next stripe to process
3546 *
3547 * Full stripe writes are allowed to pass preread active stripes up until
3548 * the bypass_threshold is exceeded. In general the bypass_count
3549 * increments when the handle_list is handled before the hold_list; however, it
3550 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3551 * stripe with in flight i/o. The bypass_count will be reset when the
3552 * head of the hold_list has changed, i.e. the head was promoted to the
3553 * handle_list.
3554 */
3555static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3556{
3557 struct stripe_head *sh;
3558
3559 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3560 __func__,
3561 list_empty(&conf->handle_list) ? "empty" : "busy",
3562 list_empty(&conf->hold_list) ? "empty" : "busy",
3563 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3564
3565 if (!list_empty(&conf->handle_list)) {
3566 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3567
3568 if (list_empty(&conf->hold_list))
3569 conf->bypass_count = 0;
3570 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3571 if (conf->hold_list.next == conf->last_hold)
3572 conf->bypass_count++;
3573 else {
3574 conf->last_hold = conf->hold_list.next;
3575 conf->bypass_count -= conf->bypass_threshold;
3576 if (conf->bypass_count < 0)
3577 conf->bypass_count = 0;
3578 }
3579 }
3580 } else if (!list_empty(&conf->hold_list) &&
3581 ((conf->bypass_threshold &&
3582 conf->bypass_count > conf->bypass_threshold) ||
3583 atomic_read(&conf->pending_full_writes) == 0)) {
3584 sh = list_entry(conf->hold_list.next,
3585 typeof(*sh), lru);
3586 conf->bypass_count -= conf->bypass_threshold;
3587 if (conf->bypass_count < 0)
3588 conf->bypass_count = 0;
3589 } else
3590 return NULL;
3591
3592 list_del_init(&sh->lru);
3593 atomic_inc(&sh->count);
3594 BUG_ON(atomic_read(&sh->count) != 1);
3595 return sh;
3596}
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003597
Jens Axboe165125e2007-07-24 09:28:11 +02003598static int make_request(struct request_queue *q, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003599{
3600 mddev_t *mddev = q->queuedata;
NeilBrown070ec552009-06-16 16:54:21 +10003601 raid5_conf_t *conf = mddev->private;
NeilBrown911d4ee2009-03-31 14:39:38 +11003602 int dd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003603 sector_t new_sector;
3604 sector_t logical_sector, last_sector;
3605 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01003606 const int rw = bio_data_dir(bi);
Tejun Heoc9959052008-08-25 19:47:21 +09003607 int cpu, remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003608
Jens Axboe1f98a132009-09-11 14:32:04 +02003609 if (unlikely(bio_rw_flagged(bi, BIO_RW_BARRIER))) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003610 bio_endio(bi, -EOPNOTSUPP);
NeilBrowne5dcdd82005-09-09 16:23:41 -07003611 return 0;
3612 }
3613
NeilBrown3d310eb2005-06-21 17:17:26 -07003614 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07003615
Tejun Heo074a7ac2008-08-25 19:56:14 +09003616 cpu = part_stat_lock();
3617 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
3618 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
3619 bio_sectors(bi));
3620 part_stat_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003621
NeilBrown802ba062006-12-13 00:34:13 -08003622 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003623 mddev->reshape_position == MaxSector &&
3624 chunk_aligned_read(q,bi))
NeilBrown99c0fb52009-03-31 14:39:38 +11003625 return 0;
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003626
Linus Torvalds1da177e2005-04-16 15:20:36 -07003627 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3628 last_sector = bi->bi_sector + (bi->bi_size>>9);
3629 bi->bi_next = NULL;
3630 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07003631
Linus Torvalds1da177e2005-04-16 15:20:36 -07003632 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3633 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07003634 int disks, data_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003635 int previous;
NeilBrownb578d552006-03-27 01:18:12 -08003636
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003637 retry:
NeilBrownb5663ba2009-03-31 14:39:38 +11003638 previous = 0;
NeilBrownb0f9ec02009-03-31 15:27:18 +11003639 disks = conf->raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003640 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003641 if (unlikely(conf->reshape_progress != MaxSector)) {
NeilBrownfef9c612009-03-31 15:16:46 +11003642 /* spinlock is needed as reshape_progress may be
NeilBrowndf8e7f72006-03-27 01:18:15 -08003643 * 64bit on a 32bit platform, and so it might be
3644 * possible to see a half-updated value
NeilBrownfef9c612009-03-31 15:16:46 +11003645 * Ofcourse reshape_progress could change after
NeilBrowndf8e7f72006-03-27 01:18:15 -08003646 * the lock is dropped, so once we get a reference
3647 * to the stripe that we think it is, we will have
3648 * to check again.
3649 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003650 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003651 if (mddev->delta_disks < 0
3652 ? logical_sector < conf->reshape_progress
3653 : logical_sector >= conf->reshape_progress) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003654 disks = conf->previous_raid_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003655 previous = 1;
3656 } else {
NeilBrownfef9c612009-03-31 15:16:46 +11003657 if (mddev->delta_disks < 0
3658 ? logical_sector < conf->reshape_safe
3659 : logical_sector >= conf->reshape_safe) {
NeilBrownb578d552006-03-27 01:18:12 -08003660 spin_unlock_irq(&conf->device_lock);
3661 schedule();
3662 goto retry;
3663 }
3664 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003665 spin_unlock_irq(&conf->device_lock);
3666 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003667 data_disks = disks - conf->max_degraded;
3668
NeilBrown112bf892009-03-31 14:39:38 +11003669 new_sector = raid5_compute_sector(conf, logical_sector,
3670 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11003671 &dd_idx, NULL);
Dan Williams45b42332007-07-09 11:56:43 -07003672 pr_debug("raid5: make_request, sector %llu logical %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07003673 (unsigned long long)new_sector,
3674 (unsigned long long)logical_sector);
3675
NeilBrownb5663ba2009-03-31 14:39:38 +11003676 sh = get_active_stripe(conf, new_sector, previous,
NeilBrowna8c906c2009-06-09 14:39:59 +10003677 (bi->bi_rw&RWA_MASK), 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003678 if (sh) {
NeilBrownb0f9ec02009-03-31 15:27:18 +11003679 if (unlikely(previous)) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003680 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08003681 * stripe, so we must do the range check again.
3682 * Expansion could still move past after this
3683 * test, but as we are holding a reference to
3684 * 'sh', we know that if that happens,
3685 * STRIPE_EXPANDING will get set and the expansion
3686 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003687 */
3688 int must_retry = 0;
3689 spin_lock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003690 if (mddev->delta_disks < 0
3691 ? logical_sector >= conf->reshape_progress
3692 : logical_sector < conf->reshape_progress)
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003693 /* mismatch, need to try again */
3694 must_retry = 1;
3695 spin_unlock_irq(&conf->device_lock);
3696 if (must_retry) {
3697 release_stripe(sh);
Dan Williams7a3ab902009-06-16 16:00:33 -07003698 schedule();
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003699 goto retry;
3700 }
3701 }
NeilBrowne62e58a2009-07-01 13:15:35 +10003702
NeilBrowna5c308d2009-07-01 13:15:35 +10003703 if (bio_data_dir(bi) == WRITE &&
3704 logical_sector >= mddev->suspend_lo &&
NeilBrowne464eaf2006-03-27 01:18:14 -08003705 logical_sector < mddev->suspend_hi) {
3706 release_stripe(sh);
NeilBrowne62e58a2009-07-01 13:15:35 +10003707 /* As the suspend_* range is controlled by
3708 * userspace, we want an interruptible
3709 * wait.
3710 */
3711 flush_signals(current);
3712 prepare_to_wait(&conf->wait_for_overlap,
3713 &w, TASK_INTERRUPTIBLE);
3714 if (logical_sector >= mddev->suspend_lo &&
3715 logical_sector < mddev->suspend_hi)
3716 schedule();
NeilBrowne464eaf2006-03-27 01:18:14 -08003717 goto retry;
3718 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003719
3720 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3721 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3722 /* Stripe is busy expanding or
3723 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07003724 * and wait a while
3725 */
3726 raid5_unplug_device(mddev->queue);
3727 release_stripe(sh);
3728 schedule();
3729 goto retry;
3730 }
3731 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown6ed30032008-02-06 01:40:00 -08003732 set_bit(STRIPE_HANDLE, &sh->state);
3733 clear_bit(STRIPE_DELAYED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003734 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003735 } else {
3736 /* cannot get stripe for read-ahead, just give-up */
3737 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3738 finish_wait(&conf->wait_for_overlap, &w);
3739 break;
3740 }
3741
3742 }
3743 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02003744 remaining = raid5_dec_bi_phys_segments(bi);
NeilBrownf6344752006-03-27 01:18:17 -08003745 spin_unlock_irq(&conf->device_lock);
3746 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003747
NeilBrown16a53ec2006-06-26 00:27:38 -07003748 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07003749 md_write_end(mddev);
NeilBrown6712ecf2007-09-27 12:47:43 +02003750
Neil Brown0e13fe232008-06-28 08:31:20 +10003751 bio_endio(bi, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003752 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003753 return 0;
3754}
3755
Dan Williamsb522adc2009-03-31 15:00:31 +11003756static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
3757
NeilBrown52c03292006-06-26 00:27:43 -07003758static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003759{
NeilBrown52c03292006-06-26 00:27:43 -07003760 /* reshaping is quite different to recovery/resync so it is
3761 * handled quite separately ... here.
3762 *
3763 * On each call to sync_request, we gather one chunk worth of
3764 * destination stripes and flag them as expanding.
3765 * Then we find all the source stripes and request reads.
3766 * As the reads complete, handle_stripe will copy the data
3767 * into the destination stripe and release that stripe.
3768 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003769 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3770 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08003771 sector_t first_sector, last_sector;
NeilBrownf4168852007-02-28 20:11:53 -08003772 int raid_disks = conf->previous_raid_disks;
3773 int data_disks = raid_disks - conf->max_degraded;
3774 int new_data_disks = conf->raid_disks - conf->max_degraded;
NeilBrown52c03292006-06-26 00:27:43 -07003775 int i;
3776 int dd_idx;
NeilBrownc8f517c2009-03-31 15:28:40 +11003777 sector_t writepos, readpos, safepos;
NeilBrownec32a2b2009-03-31 15:17:38 +11003778 sector_t stripe_addr;
NeilBrown7a661382009-03-31 15:21:40 +11003779 int reshape_sectors;
NeilBrownab69ae12009-03-31 15:26:47 +11003780 struct list_head stripes;
NeilBrown52c03292006-06-26 00:27:43 -07003781
NeilBrownfef9c612009-03-31 15:16:46 +11003782 if (sector_nr == 0) {
3783 /* If restarting in the middle, skip the initial sectors */
3784 if (mddev->delta_disks < 0 &&
3785 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
3786 sector_nr = raid5_size(mddev, 0, 0)
3787 - conf->reshape_progress;
NeilBrowna6397552009-08-13 10:13:00 +10003788 } else if (mddev->delta_disks >= 0 &&
NeilBrownfef9c612009-03-31 15:16:46 +11003789 conf->reshape_progress > 0)
3790 sector_nr = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003791 sector_div(sector_nr, new_data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003792 if (sector_nr) {
3793 *skipped = 1;
3794 return sector_nr;
3795 }
NeilBrown52c03292006-06-26 00:27:43 -07003796 }
3797
NeilBrown7a661382009-03-31 15:21:40 +11003798 /* We need to process a full chunk at a time.
3799 * If old and new chunk sizes differ, we need to process the
3800 * largest of these
3801 */
Andre Noll664e7c42009-06-18 08:45:27 +10003802 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
3803 reshape_sectors = mddev->new_chunk_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11003804 else
Andre Noll9d8f0362009-06-18 08:45:01 +10003805 reshape_sectors = mddev->chunk_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11003806
NeilBrown52c03292006-06-26 00:27:43 -07003807 /* we update the metadata when there is more than 3Meg
3808 * in the block range (that is rather arbitrary, should
3809 * probably be time based) or when the data about to be
3810 * copied would over-write the source of the data at
3811 * the front of the range.
NeilBrownfef9c612009-03-31 15:16:46 +11003812 * i.e. one new_stripe along from reshape_progress new_maps
3813 * to after where reshape_safe old_maps to
NeilBrown52c03292006-06-26 00:27:43 -07003814 */
NeilBrownfef9c612009-03-31 15:16:46 +11003815 writepos = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003816 sector_div(writepos, new_data_disks);
NeilBrownc8f517c2009-03-31 15:28:40 +11003817 readpos = conf->reshape_progress;
3818 sector_div(readpos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003819 safepos = conf->reshape_safe;
NeilBrownf4168852007-02-28 20:11:53 -08003820 sector_div(safepos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11003821 if (mddev->delta_disks < 0) {
NeilBrowned37d832009-05-27 21:39:05 +10003822 writepos -= min_t(sector_t, reshape_sectors, writepos);
NeilBrownc8f517c2009-03-31 15:28:40 +11003823 readpos += reshape_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11003824 safepos += reshape_sectors;
NeilBrownfef9c612009-03-31 15:16:46 +11003825 } else {
NeilBrown7a661382009-03-31 15:21:40 +11003826 writepos += reshape_sectors;
NeilBrowned37d832009-05-27 21:39:05 +10003827 readpos -= min_t(sector_t, reshape_sectors, readpos);
3828 safepos -= min_t(sector_t, reshape_sectors, safepos);
NeilBrownfef9c612009-03-31 15:16:46 +11003829 }
NeilBrown52c03292006-06-26 00:27:43 -07003830
NeilBrownc8f517c2009-03-31 15:28:40 +11003831 /* 'writepos' is the most advanced device address we might write.
3832 * 'readpos' is the least advanced device address we might read.
3833 * 'safepos' is the least address recorded in the metadata as having
3834 * been reshaped.
3835 * If 'readpos' is behind 'writepos', then there is no way that we can
3836 * ensure safety in the face of a crash - that must be done by userspace
3837 * making a backup of the data. So in that case there is no particular
3838 * rush to update metadata.
3839 * Otherwise if 'safepos' is behind 'writepos', then we really need to
3840 * update the metadata to advance 'safepos' to match 'readpos' so that
3841 * we can be safe in the event of a crash.
3842 * So we insist on updating metadata if safepos is behind writepos and
3843 * readpos is beyond writepos.
3844 * In any case, update the metadata every 10 seconds.
3845 * Maybe that number should be configurable, but I'm not sure it is
3846 * worth it.... maybe it could be a multiple of safemode_delay???
3847 */
NeilBrownfef9c612009-03-31 15:16:46 +11003848 if ((mddev->delta_disks < 0
NeilBrownc8f517c2009-03-31 15:28:40 +11003849 ? (safepos > writepos && readpos < writepos)
3850 : (safepos < writepos && readpos > writepos)) ||
3851 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
NeilBrown52c03292006-06-26 00:27:43 -07003852 /* Cannot proceed until we've updated the superblock... */
3853 wait_event(conf->wait_for_overlap,
3854 atomic_read(&conf->reshape_stripes)==0);
NeilBrownfef9c612009-03-31 15:16:46 +11003855 mddev->reshape_position = conf->reshape_progress;
NeilBrownacb180b2009-04-14 16:28:34 +10003856 mddev->curr_resync_completed = mddev->curr_resync;
NeilBrownc8f517c2009-03-31 15:28:40 +11003857 conf->reshape_checkpoint = jiffies;
NeilBrown850b2b42006-10-03 01:15:46 -07003858 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07003859 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07003860 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07003861 kthread_should_stop());
3862 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003863 conf->reshape_safe = mddev->reshape_position;
NeilBrown52c03292006-06-26 00:27:43 -07003864 spin_unlock_irq(&conf->device_lock);
3865 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10003866 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrown52c03292006-06-26 00:27:43 -07003867 }
3868
NeilBrownec32a2b2009-03-31 15:17:38 +11003869 if (mddev->delta_disks < 0) {
3870 BUG_ON(conf->reshape_progress == 0);
3871 stripe_addr = writepos;
3872 BUG_ON((mddev->dev_sectors &
NeilBrown7a661382009-03-31 15:21:40 +11003873 ~((sector_t)reshape_sectors - 1))
3874 - reshape_sectors - stripe_addr
NeilBrownec32a2b2009-03-31 15:17:38 +11003875 != sector_nr);
3876 } else {
NeilBrown7a661382009-03-31 15:21:40 +11003877 BUG_ON(writepos != sector_nr + reshape_sectors);
NeilBrownec32a2b2009-03-31 15:17:38 +11003878 stripe_addr = sector_nr;
3879 }
NeilBrownab69ae12009-03-31 15:26:47 +11003880 INIT_LIST_HEAD(&stripes);
NeilBrown7a661382009-03-31 15:21:40 +11003881 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
NeilBrown52c03292006-06-26 00:27:43 -07003882 int j;
3883 int skipped = 0;
NeilBrowna8c906c2009-06-09 14:39:59 +10003884 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
NeilBrown52c03292006-06-26 00:27:43 -07003885 set_bit(STRIPE_EXPANDING, &sh->state);
3886 atomic_inc(&conf->reshape_stripes);
3887 /* If any of this stripe is beyond the end of the old
3888 * array, then we need to zero those blocks
3889 */
3890 for (j=sh->disks; j--;) {
3891 sector_t s;
3892 if (j == sh->pd_idx)
3893 continue;
NeilBrownf4168852007-02-28 20:11:53 -08003894 if (conf->level == 6 &&
NeilBrownd0dabf72009-03-31 14:39:38 +11003895 j == sh->qd_idx)
NeilBrownf4168852007-02-28 20:11:53 -08003896 continue;
NeilBrown784052e2009-03-31 15:19:07 +11003897 s = compute_blocknr(sh, j, 0);
Dan Williamsb522adc2009-03-31 15:00:31 +11003898 if (s < raid5_size(mddev, 0, 0)) {
NeilBrown52c03292006-06-26 00:27:43 -07003899 skipped = 1;
3900 continue;
3901 }
3902 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3903 set_bit(R5_Expanded, &sh->dev[j].flags);
3904 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3905 }
3906 if (!skipped) {
3907 set_bit(STRIPE_EXPAND_READY, &sh->state);
3908 set_bit(STRIPE_HANDLE, &sh->state);
3909 }
NeilBrownab69ae12009-03-31 15:26:47 +11003910 list_add(&sh->lru, &stripes);
NeilBrown52c03292006-06-26 00:27:43 -07003911 }
3912 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003913 if (mddev->delta_disks < 0)
NeilBrown7a661382009-03-31 15:21:40 +11003914 conf->reshape_progress -= reshape_sectors * new_data_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11003915 else
NeilBrown7a661382009-03-31 15:21:40 +11003916 conf->reshape_progress += reshape_sectors * new_data_disks;
NeilBrown52c03292006-06-26 00:27:43 -07003917 spin_unlock_irq(&conf->device_lock);
3918 /* Ok, those stripe are ready. We can start scheduling
3919 * reads on the source stripes.
3920 * The source stripes are determined by mapping the first and last
3921 * block on the destination stripes.
3922 */
NeilBrown52c03292006-06-26 00:27:43 -07003923 first_sector =
NeilBrownec32a2b2009-03-31 15:17:38 +11003924 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
NeilBrown911d4ee2009-03-31 14:39:38 +11003925 1, &dd_idx, NULL);
NeilBrown52c03292006-06-26 00:27:43 -07003926 last_sector =
NeilBrown0e6e0272009-06-09 16:32:22 +10003927 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
Andre Noll09c9e5f2009-06-18 08:45:55 +10003928 * new_data_disks - 1),
NeilBrown911d4ee2009-03-31 14:39:38 +11003929 1, &dd_idx, NULL);
Andre Noll58c0fed2009-03-31 14:33:13 +11003930 if (last_sector >= mddev->dev_sectors)
3931 last_sector = mddev->dev_sectors - 1;
NeilBrown52c03292006-06-26 00:27:43 -07003932 while (first_sector <= last_sector) {
NeilBrowna8c906c2009-06-09 14:39:59 +10003933 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
NeilBrown52c03292006-06-26 00:27:43 -07003934 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3935 set_bit(STRIPE_HANDLE, &sh->state);
3936 release_stripe(sh);
3937 first_sector += STRIPE_SECTORS;
3938 }
NeilBrownab69ae12009-03-31 15:26:47 +11003939 /* Now that the sources are clearly marked, we can release
3940 * the destination stripes
3941 */
3942 while (!list_empty(&stripes)) {
3943 sh = list_entry(stripes.next, struct stripe_head, lru);
3944 list_del_init(&sh->lru);
3945 release_stripe(sh);
3946 }
NeilBrownc6207272008-02-06 01:39:52 -08003947 /* If this takes us to the resync_max point where we have to pause,
3948 * then we need to write out the superblock.
3949 */
NeilBrown7a661382009-03-31 15:21:40 +11003950 sector_nr += reshape_sectors;
NeilBrownc03f6a12009-04-17 11:06:30 +10003951 if ((sector_nr - mddev->curr_resync_completed) * 2
3952 >= mddev->resync_max - mddev->curr_resync_completed) {
NeilBrownc6207272008-02-06 01:39:52 -08003953 /* Cannot proceed until we've updated the superblock... */
3954 wait_event(conf->wait_for_overlap,
3955 atomic_read(&conf->reshape_stripes) == 0);
NeilBrownfef9c612009-03-31 15:16:46 +11003956 mddev->reshape_position = conf->reshape_progress;
NeilBrown48606a92009-06-18 09:14:12 +10003957 mddev->curr_resync_completed = mddev->curr_resync + reshape_sectors;
NeilBrownc8f517c2009-03-31 15:28:40 +11003958 conf->reshape_checkpoint = jiffies;
NeilBrownc6207272008-02-06 01:39:52 -08003959 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3960 md_wakeup_thread(mddev->thread);
3961 wait_event(mddev->sb_wait,
3962 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3963 || kthread_should_stop());
3964 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003965 conf->reshape_safe = mddev->reshape_position;
NeilBrownc6207272008-02-06 01:39:52 -08003966 spin_unlock_irq(&conf->device_lock);
3967 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10003968 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrownc6207272008-02-06 01:39:52 -08003969 }
NeilBrown7a661382009-03-31 15:21:40 +11003970 return reshape_sectors;
NeilBrown52c03292006-06-26 00:27:43 -07003971}
3972
3973/* FIXME go_faster isn't used */
3974static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3975{
3976 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3977 struct stripe_head *sh;
Andre Noll58c0fed2009-03-31 14:33:13 +11003978 sector_t max_sector = mddev->dev_sectors;
NeilBrown72626682005-09-09 16:23:54 -07003979 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07003980 int still_degraded = 0;
3981 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003982
NeilBrown72626682005-09-09 16:23:54 -07003983 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003984 /* just being told to finish up .. nothing much to do */
3985 unplug_slaves(mddev);
NeilBrowncea9c222009-03-31 15:15:05 +11003986
NeilBrown29269552006-03-27 01:18:10 -08003987 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3988 end_reshape(conf);
3989 return 0;
3990 }
NeilBrown72626682005-09-09 16:23:54 -07003991
3992 if (mddev->curr_resync < max_sector) /* aborted */
3993 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3994 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003995 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07003996 conf->fullsync = 0;
3997 bitmap_close_sync(mddev->bitmap);
3998
Linus Torvalds1da177e2005-04-16 15:20:36 -07003999 return 0;
4000 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08004001
NeilBrown64bd6602009-08-03 10:59:58 +10004002 /* Allow raid5_quiesce to complete */
4003 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4004
NeilBrown52c03292006-06-26 00:27:43 -07004005 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4006 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08004007
NeilBrownc6207272008-02-06 01:39:52 -08004008 /* No need to check resync_max as we never do more than one
4009 * stripe, and as resync_max will always be on a chunk boundary,
4010 * if the check in md_do_sync didn't fire, there is no chance
4011 * of overstepping resync_max here
4012 */
4013
NeilBrown16a53ec2006-06-26 00:27:38 -07004014 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07004015 * to resync, then assert that we are finished, because there is
4016 * nothing we can do.
4017 */
NeilBrown3285edf2006-06-26 00:27:55 -07004018 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07004019 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
Andre Noll58c0fed2009-03-31 14:33:13 +11004020 sector_t rv = mddev->dev_sectors - sector_nr;
NeilBrown57afd892005-06-21 17:17:13 -07004021 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004022 return rv;
4023 }
NeilBrown72626682005-09-09 16:23:54 -07004024 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08004025 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07004026 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4027 /* we can skip this block, and probably more */
4028 sync_blocks /= STRIPE_SECTORS;
4029 *skipped = 1;
4030 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4031 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004032
NeilBrownb47490c2008-02-06 01:39:50 -08004033
4034 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4035
NeilBrowna8c906c2009-06-09 14:39:59 +10004036 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004037 if (sh == NULL) {
NeilBrowna8c906c2009-06-09 14:39:59 +10004038 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004039 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07004040 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07004041 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08004042 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004043 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004044 /* Need to check if array will still be degraded after recovery/resync
4045 * We don't need to check the 'failed' flag as when that gets set,
4046 * recovery aborts.
4047 */
NeilBrownf001a702009-06-09 14:30:31 +10004048 for (i = 0; i < conf->raid_disks; i++)
NeilBrown16a53ec2006-06-26 00:27:38 -07004049 if (conf->disks[i].rdev == NULL)
4050 still_degraded = 1;
4051
4052 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4053
4054 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004055 set_bit(STRIPE_SYNCING, &sh->state);
4056 clear_bit(STRIPE_INSYNC, &sh->state);
4057 spin_unlock(&sh->lock);
4058
Dan Williamsdf10cfb2008-07-28 23:10:39 -07004059 /* wait for any blocked device to be handled */
4060 while(unlikely(!handle_stripe(sh, NULL)))
4061 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062 release_stripe(sh);
4063
4064 return STRIPE_SECTORS;
4065}
4066
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004067static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4068{
4069 /* We may not be able to submit a whole bio at once as there
4070 * may not be enough stripe_heads available.
4071 * We cannot pre-allocate enough stripe_heads as we may need
4072 * more than exist in the cache (if we allow ever large chunks).
4073 * So we do one stripe head at a time and record in
4074 * ->bi_hw_segments how many have been done.
4075 *
4076 * We *know* that this entire raid_bio is in one chunk, so
4077 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4078 */
4079 struct stripe_head *sh;
NeilBrown911d4ee2009-03-31 14:39:38 +11004080 int dd_idx;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004081 sector_t sector, logical_sector, last_sector;
4082 int scnt = 0;
4083 int remaining;
4084 int handled = 0;
4085
4086 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
NeilBrown112bf892009-03-31 14:39:38 +11004087 sector = raid5_compute_sector(conf, logical_sector,
NeilBrown911d4ee2009-03-31 14:39:38 +11004088 0, &dd_idx, NULL);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004089 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4090
4091 for (; logical_sector < last_sector;
Neil Brown387bb172007-02-08 14:20:29 -08004092 logical_sector += STRIPE_SECTORS,
4093 sector += STRIPE_SECTORS,
4094 scnt++) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004095
Jens Axboe960e7392008-08-15 10:41:18 +02004096 if (scnt < raid5_bi_hw_segments(raid_bio))
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004097 /* already done this stripe */
4098 continue;
4099
NeilBrowna8c906c2009-06-09 14:39:59 +10004100 sh = get_active_stripe(conf, sector, 0, 1, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004101
4102 if (!sh) {
4103 /* failed to get a stripe - must wait */
Jens Axboe960e7392008-08-15 10:41:18 +02004104 raid5_set_bi_hw_segments(raid_bio, scnt);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004105 conf->retry_read_aligned = raid_bio;
4106 return handled;
4107 }
4108
4109 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
Neil Brown387bb172007-02-08 14:20:29 -08004110 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4111 release_stripe(sh);
Jens Axboe960e7392008-08-15 10:41:18 +02004112 raid5_set_bi_hw_segments(raid_bio, scnt);
Neil Brown387bb172007-02-08 14:20:29 -08004113 conf->retry_read_aligned = raid_bio;
4114 return handled;
4115 }
4116
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004117 handle_stripe(sh, NULL);
4118 release_stripe(sh);
4119 handled++;
4120 }
4121 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02004122 remaining = raid5_dec_bi_phys_segments(raid_bio);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004123 spin_unlock_irq(&conf->device_lock);
Neil Brown0e13fe232008-06-28 08:31:20 +10004124 if (remaining == 0)
4125 bio_endio(raid_bio, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004126 if (atomic_dec_and_test(&conf->active_aligned_reads))
4127 wake_up(&conf->wait_for_stripe);
4128 return handled;
4129}
4130
4131
4132
Linus Torvalds1da177e2005-04-16 15:20:36 -07004133/*
4134 * This is our raid5 kernel thread.
4135 *
4136 * We scan the hash table for stripes which can be handled now.
4137 * During the scan, completed stripes are saved for us by the interrupt
4138 * handler, so that they will not have to wait for our next wakeup.
4139 */
NeilBrown6ed30032008-02-06 01:40:00 -08004140static void raid5d(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004141{
4142 struct stripe_head *sh;
NeilBrown070ec552009-06-16 16:54:21 +10004143 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004144 int handled;
4145
Dan Williams45b42332007-07-09 11:56:43 -07004146 pr_debug("+++ raid5d active\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004147
4148 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004149
4150 handled = 0;
4151 spin_lock_irq(&conf->device_lock);
4152 while (1) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004153 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004154
NeilBrownae3c20c2006-07-10 04:44:17 -07004155 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07004156 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08004157 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004158 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08004159 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004160 conf->seq_write = seq;
4161 activate_bit_delay(conf);
4162 }
4163
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004164 while ((bio = remove_bio_from_retry(conf))) {
4165 int ok;
4166 spin_unlock_irq(&conf->device_lock);
4167 ok = retry_aligned_read(conf, bio);
4168 spin_lock_irq(&conf->device_lock);
4169 if (!ok)
4170 break;
4171 handled++;
4172 }
4173
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004174 sh = __get_priority_stripe(conf);
4175
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004176 if (!sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004177 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004178 spin_unlock_irq(&conf->device_lock);
4179
4180 handled++;
NeilBrown16a53ec2006-06-26 00:27:38 -07004181 handle_stripe(sh, conf->spare_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004182 release_stripe(sh);
4183
4184 spin_lock_irq(&conf->device_lock);
4185 }
Dan Williams45b42332007-07-09 11:56:43 -07004186 pr_debug("%d stripes handled\n", handled);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004187
4188 spin_unlock_irq(&conf->device_lock);
4189
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004190 async_tx_issue_pending_all();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004191 unplug_slaves(mddev);
4192
Dan Williams45b42332007-07-09 11:56:43 -07004193 pr_debug("--- raid5d inactive\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004194}
4195
NeilBrown3f294f42005-11-08 21:39:25 -08004196static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004197raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004198{
NeilBrown070ec552009-06-16 16:54:21 +10004199 raid5_conf_t *conf = mddev->private;
NeilBrown96de1e62005-11-08 21:39:39 -08004200 if (conf)
4201 return sprintf(page, "%d\n", conf->max_nr_stripes);
4202 else
4203 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004204}
4205
4206static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004207raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08004208{
NeilBrown070ec552009-06-16 16:54:21 +10004209 raid5_conf_t *conf = mddev->private;
Dan Williams4ef197d82008-04-28 02:15:54 -07004210 unsigned long new;
Dan Williamsb5470dc2008-06-27 21:44:04 -07004211 int err;
4212
NeilBrown3f294f42005-11-08 21:39:25 -08004213 if (len >= PAGE_SIZE)
4214 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08004215 if (!conf)
4216 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08004217
Dan Williams4ef197d82008-04-28 02:15:54 -07004218 if (strict_strtoul(page, 10, &new))
NeilBrown3f294f42005-11-08 21:39:25 -08004219 return -EINVAL;
4220 if (new <= 16 || new > 32768)
4221 return -EINVAL;
4222 while (new < conf->max_nr_stripes) {
4223 if (drop_one_stripe(conf))
4224 conf->max_nr_stripes--;
4225 else
4226 break;
4227 }
Dan Williamsb5470dc2008-06-27 21:44:04 -07004228 err = md_allow_write(mddev);
4229 if (err)
4230 return err;
NeilBrown3f294f42005-11-08 21:39:25 -08004231 while (new > conf->max_nr_stripes) {
4232 if (grow_one_stripe(conf))
4233 conf->max_nr_stripes++;
4234 else break;
4235 }
4236 return len;
4237}
NeilBrown007583c2005-11-08 21:39:30 -08004238
NeilBrown96de1e62005-11-08 21:39:39 -08004239static struct md_sysfs_entry
4240raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4241 raid5_show_stripe_cache_size,
4242 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08004243
4244static ssize_t
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004245raid5_show_preread_threshold(mddev_t *mddev, char *page)
4246{
NeilBrown070ec552009-06-16 16:54:21 +10004247 raid5_conf_t *conf = mddev->private;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004248 if (conf)
4249 return sprintf(page, "%d\n", conf->bypass_threshold);
4250 else
4251 return 0;
4252}
4253
4254static ssize_t
4255raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4256{
NeilBrown070ec552009-06-16 16:54:21 +10004257 raid5_conf_t *conf = mddev->private;
Dan Williams4ef197d82008-04-28 02:15:54 -07004258 unsigned long new;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004259 if (len >= PAGE_SIZE)
4260 return -EINVAL;
4261 if (!conf)
4262 return -ENODEV;
4263
Dan Williams4ef197d82008-04-28 02:15:54 -07004264 if (strict_strtoul(page, 10, &new))
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004265 return -EINVAL;
Dan Williams4ef197d82008-04-28 02:15:54 -07004266 if (new > conf->max_nr_stripes)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004267 return -EINVAL;
4268 conf->bypass_threshold = new;
4269 return len;
4270}
4271
4272static struct md_sysfs_entry
4273raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4274 S_IRUGO | S_IWUSR,
4275 raid5_show_preread_threshold,
4276 raid5_store_preread_threshold);
4277
4278static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08004279stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004280{
NeilBrown070ec552009-06-16 16:54:21 +10004281 raid5_conf_t *conf = mddev->private;
NeilBrown96de1e62005-11-08 21:39:39 -08004282 if (conf)
4283 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4284 else
4285 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004286}
4287
NeilBrown96de1e62005-11-08 21:39:39 -08004288static struct md_sysfs_entry
4289raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08004290
NeilBrown007583c2005-11-08 21:39:30 -08004291static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08004292 &raid5_stripecache_size.attr,
4293 &raid5_stripecache_active.attr,
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004294 &raid5_preread_bypass_threshold.attr,
NeilBrown3f294f42005-11-08 21:39:25 -08004295 NULL,
4296};
NeilBrown007583c2005-11-08 21:39:30 -08004297static struct attribute_group raid5_attrs_group = {
4298 .name = NULL,
4299 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08004300};
4301
Dan Williams80c3a6c2009-03-17 18:10:40 -07004302static sector_t
4303raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4304{
NeilBrown070ec552009-06-16 16:54:21 +10004305 raid5_conf_t *conf = mddev->private;
Dan Williams80c3a6c2009-03-17 18:10:40 -07004306
4307 if (!sectors)
4308 sectors = mddev->dev_sectors;
NeilBrown7ec05472009-03-31 15:10:36 +11004309 if (!raid_disks) {
4310 /* size is defined by the smallest of previous and new size */
4311 if (conf->raid_disks < conf->previous_raid_disks)
4312 raid_disks = conf->raid_disks;
4313 else
4314 raid_disks = conf->previous_raid_disks;
4315 }
Dan Williams80c3a6c2009-03-17 18:10:40 -07004316
Andre Noll9d8f0362009-06-18 08:45:01 +10004317 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
Andre Noll664e7c42009-06-18 08:45:27 +10004318 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
Dan Williams80c3a6c2009-03-17 18:10:40 -07004319 return sectors * (raid_disks - conf->max_degraded);
4320}
4321
Dan Williams95fc17a2009-07-31 12:39:15 +10004322static void free_conf(raid5_conf_t *conf)
4323{
4324 shrink_stripes(conf);
4325 safe_put_page(conf->spare_page);
4326 kfree(conf->disks);
4327 kfree(conf->stripe_hashtbl);
4328 kfree(conf);
4329}
4330
NeilBrown91adb562009-03-31 14:39:39 +11004331static raid5_conf_t *setup_conf(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004332{
4333 raid5_conf_t *conf;
4334 int raid_disk, memory;
4335 mdk_rdev_t *rdev;
4336 struct disk_info *disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004337
NeilBrown91adb562009-03-31 14:39:39 +11004338 if (mddev->new_level != 5
4339 && mddev->new_level != 4
4340 && mddev->new_level != 6) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004341 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
NeilBrown91adb562009-03-31 14:39:39 +11004342 mdname(mddev), mddev->new_level);
4343 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004344 }
NeilBrown91adb562009-03-31 14:39:39 +11004345 if ((mddev->new_level == 5
4346 && !algorithm_valid_raid5(mddev->new_layout)) ||
4347 (mddev->new_level == 6
4348 && !algorithm_valid_raid6(mddev->new_layout))) {
NeilBrown99c0fb52009-03-31 14:39:38 +11004349 printk(KERN_ERR "raid5: %s: layout %d not supported\n",
NeilBrown91adb562009-03-31 14:39:39 +11004350 mdname(mddev), mddev->new_layout);
4351 return ERR_PTR(-EIO);
4352 }
4353 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
4354 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4355 mdname(mddev), mddev->raid_disks);
4356 return ERR_PTR(-EINVAL);
NeilBrown99c0fb52009-03-31 14:39:38 +11004357 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004358
Andre Noll664e7c42009-06-18 08:45:27 +10004359 if (!mddev->new_chunk_sectors ||
4360 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4361 !is_power_of_2(mddev->new_chunk_sectors)) {
NeilBrown91adb562009-03-31 14:39:39 +11004362 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
Andre Noll664e7c42009-06-18 08:45:27 +10004363 mddev->new_chunk_sectors << 9, mdname(mddev));
NeilBrown91adb562009-03-31 14:39:39 +11004364 return ERR_PTR(-EINVAL);
NeilBrown4bbf3772008-10-13 11:55:12 +11004365 }
4366
NeilBrown91adb562009-03-31 14:39:39 +11004367 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4368 if (conf == NULL)
4369 goto abort;
4370
4371 conf->raid_disks = mddev->raid_disks;
4372 if (mddev->reshape_position == MaxSector)
4373 conf->previous_raid_disks = mddev->raid_disks;
4374 else
4375 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4376
4377 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
4378 GFP_KERNEL);
4379 if (!conf->disks)
4380 goto abort;
4381
4382 conf->mddev = mddev;
4383
4384 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4385 goto abort;
4386
4387 if (mddev->new_level == 6) {
4388 conf->spare_page = alloc_page(GFP_KERNEL);
4389 if (!conf->spare_page)
4390 goto abort;
4391 }
4392 spin_lock_init(&conf->device_lock);
4393 init_waitqueue_head(&conf->wait_for_stripe);
4394 init_waitqueue_head(&conf->wait_for_overlap);
4395 INIT_LIST_HEAD(&conf->handle_list);
4396 INIT_LIST_HEAD(&conf->hold_list);
4397 INIT_LIST_HEAD(&conf->delayed_list);
4398 INIT_LIST_HEAD(&conf->bitmap_list);
4399 INIT_LIST_HEAD(&conf->inactive_list);
4400 atomic_set(&conf->active_stripes, 0);
4401 atomic_set(&conf->preread_active_stripes, 0);
4402 atomic_set(&conf->active_aligned_reads, 0);
4403 conf->bypass_threshold = BYPASS_THRESHOLD;
4404
4405 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
4406
4407 list_for_each_entry(rdev, &mddev->disks, same_set) {
4408 raid_disk = rdev->raid_disk;
4409 if (raid_disk >= conf->raid_disks
4410 || raid_disk < 0)
4411 continue;
4412 disk = conf->disks + raid_disk;
4413
4414 disk->rdev = rdev;
4415
4416 if (test_bit(In_sync, &rdev->flags)) {
4417 char b[BDEVNAME_SIZE];
4418 printk(KERN_INFO "raid5: device %s operational as raid"
4419 " disk %d\n", bdevname(rdev->bdev,b),
4420 raid_disk);
4421 } else
4422 /* Cannot rely on bitmap to complete recovery */
4423 conf->fullsync = 1;
4424 }
4425
Andre Noll09c9e5f2009-06-18 08:45:55 +10004426 conf->chunk_sectors = mddev->new_chunk_sectors;
NeilBrown91adb562009-03-31 14:39:39 +11004427 conf->level = mddev->new_level;
4428 if (conf->level == 6)
4429 conf->max_degraded = 2;
4430 else
4431 conf->max_degraded = 1;
4432 conf->algorithm = mddev->new_layout;
4433 conf->max_nr_stripes = NR_STRIPES;
NeilBrownfef9c612009-03-31 15:16:46 +11004434 conf->reshape_progress = mddev->reshape_position;
NeilBrowne183eae2009-03-31 15:20:22 +11004435 if (conf->reshape_progress != MaxSector) {
Andre Noll09c9e5f2009-06-18 08:45:55 +10004436 conf->prev_chunk_sectors = mddev->chunk_sectors;
NeilBrowne183eae2009-03-31 15:20:22 +11004437 conf->prev_algo = mddev->layout;
4438 }
NeilBrown91adb562009-03-31 14:39:39 +11004439
4440 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4441 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4442 if (grow_stripes(conf, conf->max_nr_stripes)) {
4443 printk(KERN_ERR
4444 "raid5: couldn't allocate %dkB for buffers\n", memory);
4445 goto abort;
4446 } else
4447 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4448 memory, mdname(mddev));
4449
4450 conf->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4451 if (!conf->thread) {
4452 printk(KERN_ERR
4453 "raid5: couldn't allocate thread for %s\n",
4454 mdname(mddev));
4455 goto abort;
4456 }
4457
4458 return conf;
4459
4460 abort:
4461 if (conf) {
Dan Williams95fc17a2009-07-31 12:39:15 +10004462 free_conf(conf);
NeilBrown91adb562009-03-31 14:39:39 +11004463 return ERR_PTR(-EIO);
4464 } else
4465 return ERR_PTR(-ENOMEM);
4466}
4467
4468static int run(mddev_t *mddev)
4469{
4470 raid5_conf_t *conf;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10004471 int working_disks = 0, chunk_size;
NeilBrown91adb562009-03-31 14:39:39 +11004472 mdk_rdev_t *rdev;
4473
Andre Noll8c6ac862009-06-18 08:48:06 +10004474 if (mddev->recovery_cp != MaxSector)
4475 printk(KERN_NOTICE "raid5: %s is not clean"
4476 " -- starting background reconstruction\n",
4477 mdname(mddev));
NeilBrownf6705572006-03-27 01:18:11 -08004478 if (mddev->reshape_position != MaxSector) {
4479 /* Check that we can continue the reshape.
4480 * Currently only disks can change, it must
4481 * increase, and we must be past the point where
4482 * a stripe over-writes itself
4483 */
4484 sector_t here_new, here_old;
4485 int old_disks;
Andre Noll18b00332009-03-31 15:00:56 +11004486 int max_degraded = (mddev->level == 6 ? 2 : 1);
NeilBrownf6705572006-03-27 01:18:11 -08004487
NeilBrown88ce4932009-03-31 15:24:23 +11004488 if (mddev->new_level != mddev->level) {
NeilBrownf4168852007-02-28 20:11:53 -08004489 printk(KERN_ERR "raid5: %s: unsupported reshape "
4490 "required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004491 mdname(mddev));
4492 return -EINVAL;
4493 }
NeilBrownf6705572006-03-27 01:18:11 -08004494 old_disks = mddev->raid_disks - mddev->delta_disks;
4495 /* reshape_position must be on a new-stripe boundary, and one
NeilBrownf4168852007-02-28 20:11:53 -08004496 * further up in new geometry must map after here in old
4497 * geometry.
NeilBrownf6705572006-03-27 01:18:11 -08004498 */
4499 here_new = mddev->reshape_position;
Andre Noll664e7c42009-06-18 08:45:27 +10004500 if (sector_div(here_new, mddev->new_chunk_sectors *
NeilBrownf4168852007-02-28 20:11:53 -08004501 (mddev->raid_disks - max_degraded))) {
4502 printk(KERN_ERR "raid5: reshape_position not "
4503 "on a stripe boundary\n");
NeilBrownf6705572006-03-27 01:18:11 -08004504 return -EINVAL;
4505 }
4506 /* here_new is the stripe we will write to */
4507 here_old = mddev->reshape_position;
Andre Noll9d8f0362009-06-18 08:45:01 +10004508 sector_div(here_old, mddev->chunk_sectors *
NeilBrownf4168852007-02-28 20:11:53 -08004509 (old_disks-max_degraded));
4510 /* here_old is the first stripe that we might need to read
4511 * from */
NeilBrown67ac6012009-08-13 10:06:24 +10004512 if (mddev->delta_disks == 0) {
4513 /* We cannot be sure it is safe to start an in-place
4514 * reshape. It is only safe if user-space if monitoring
4515 * and taking constant backups.
4516 * mdadm always starts a situation like this in
4517 * readonly mode so it can take control before
4518 * allowing any writes. So just check for that.
4519 */
4520 if ((here_new * mddev->new_chunk_sectors !=
4521 here_old * mddev->chunk_sectors) ||
4522 mddev->ro == 0) {
4523 printk(KERN_ERR "raid5: in-place reshape must be started"
4524 " in read-only mode - aborting\n");
4525 return -EINVAL;
4526 }
4527 } else if (mddev->delta_disks < 0
4528 ? (here_new * mddev->new_chunk_sectors <=
4529 here_old * mddev->chunk_sectors)
4530 : (here_new * mddev->new_chunk_sectors >=
4531 here_old * mddev->chunk_sectors)) {
NeilBrownf6705572006-03-27 01:18:11 -08004532 /* Reading from the same stripe as writing to - bad */
NeilBrownf4168852007-02-28 20:11:53 -08004533 printk(KERN_ERR "raid5: reshape_position too early for "
4534 "auto-recovery - aborting.\n");
NeilBrownf6705572006-03-27 01:18:11 -08004535 return -EINVAL;
4536 }
4537 printk(KERN_INFO "raid5: reshape will continue\n");
4538 /* OK, we should be able to continue; */
NeilBrownf6705572006-03-27 01:18:11 -08004539 } else {
NeilBrown91adb562009-03-31 14:39:39 +11004540 BUG_ON(mddev->level != mddev->new_level);
4541 BUG_ON(mddev->layout != mddev->new_layout);
Andre Noll664e7c42009-06-18 08:45:27 +10004542 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
NeilBrown91adb562009-03-31 14:39:39 +11004543 BUG_ON(mddev->delta_disks != 0);
NeilBrownf6705572006-03-27 01:18:11 -08004544 }
4545
NeilBrown245f46c2009-03-31 14:39:39 +11004546 if (mddev->private == NULL)
4547 conf = setup_conf(mddev);
4548 else
4549 conf = mddev->private;
4550
NeilBrown91adb562009-03-31 14:39:39 +11004551 if (IS_ERR(conf))
4552 return PTR_ERR(conf);
NeilBrown9ffae0c2006-01-06 00:20:32 -08004553
NeilBrown91adb562009-03-31 14:39:39 +11004554 mddev->thread = conf->thread;
4555 conf->thread = NULL;
4556 mddev->private = conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004557
Linus Torvalds1da177e2005-04-16 15:20:36 -07004558 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004559 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004560 */
NeilBrown91adb562009-03-31 14:39:39 +11004561 list_for_each_entry(rdev, &mddev->disks, same_set)
4562 if (rdev->raid_disk >= 0 &&
4563 test_bit(In_sync, &rdev->flags))
4564 working_disks++;
4565
NeilBrown02c2de82006-10-03 01:15:47 -07004566 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004567
NeilBrown16a53ec2006-06-26 00:27:38 -07004568 if (mddev->degraded > conf->max_degraded) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004569 printk(KERN_ERR "raid5: not enough operational devices for %s"
4570 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07004571 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004572 goto abort;
4573 }
4574
NeilBrown91adb562009-03-31 14:39:39 +11004575 /* device size must be a multiple of chunk size */
Andre Noll9d8f0362009-06-18 08:45:01 +10004576 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
NeilBrown91adb562009-03-31 14:39:39 +11004577 mddev->resync_max_sectors = mddev->dev_sectors;
4578
NeilBrown16a53ec2006-06-26 00:27:38 -07004579 if (mddev->degraded > 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07004580 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08004581 if (mddev->ok_start_degraded)
4582 printk(KERN_WARNING
4583 "raid5: starting dirty degraded array: %s"
4584 "- data corruption possible.\n",
4585 mdname(mddev));
4586 else {
4587 printk(KERN_ERR
4588 "raid5: cannot start dirty degraded array for %s\n",
4589 mdname(mddev));
4590 goto abort;
4591 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004592 }
4593
Linus Torvalds1da177e2005-04-16 15:20:36 -07004594 if (mddev->degraded == 0)
4595 printk("raid5: raid level %d set %s active with %d out of %d"
NeilBrowne183eae2009-03-31 15:20:22 +11004596 " devices, algorithm %d\n", conf->level, mdname(mddev),
4597 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4598 mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004599 else
4600 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4601 " out of %d devices, algorithm %d\n", conf->level,
4602 mdname(mddev), mddev->raid_disks - mddev->degraded,
NeilBrowne183eae2009-03-31 15:20:22 +11004603 mddev->raid_disks, mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004604
4605 print_raid5_conf(conf);
4606
NeilBrownfef9c612009-03-31 15:16:46 +11004607 if (conf->reshape_progress != MaxSector) {
NeilBrownf6705572006-03-27 01:18:11 -08004608 printk("...ok start reshape thread\n");
NeilBrownfef9c612009-03-31 15:16:46 +11004609 conf->reshape_safe = conf->reshape_progress;
NeilBrownf6705572006-03-27 01:18:11 -08004610 atomic_set(&conf->reshape_stripes, 0);
4611 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4612 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4613 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4614 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4615 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4616 "%s_reshape");
NeilBrownf6705572006-03-27 01:18:11 -08004617 }
4618
Linus Torvalds1da177e2005-04-16 15:20:36 -07004619 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07004620 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07004621 */
4622 {
NeilBrown16a53ec2006-06-26 00:27:38 -07004623 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4624 int stripe = data_disks *
Andre Noll9d8f0362009-06-18 08:45:01 +10004625 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004626 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4627 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4628 }
4629
4630 /* Ok, everything is just fine now */
NeilBrown5e55e2f2007-03-26 21:32:14 -08004631 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4632 printk(KERN_WARNING
4633 "raid5: failed to create sysfs attributes for %s\n",
4634 mdname(mddev));
NeilBrown7a5febe2005-05-16 21:53:16 -07004635
NeilBrown91adb562009-03-31 14:39:39 +11004636 mddev->queue->queue_lock = &conf->device_lock;
4637
NeilBrown7a5febe2005-05-16 21:53:16 -07004638 mddev->queue->unplug_fn = raid5_unplug_device;
NeilBrownf022b2f2006-10-03 01:15:56 -07004639 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown041ae522007-03-26 21:32:14 -08004640 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
NeilBrownf022b2f2006-10-03 01:15:56 -07004641
Dan Williams1f403622009-03-31 14:59:03 +11004642 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
NeilBrown7a5febe2005-05-16 21:53:16 -07004643
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08004644 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10004645 chunk_size = mddev->chunk_sectors << 9;
4646 blk_queue_io_min(mddev->queue, chunk_size);
4647 blk_queue_io_opt(mddev->queue, chunk_size *
4648 (conf->raid_disks - conf->max_degraded));
4649
4650 list_for_each_entry(rdev, &mddev->disks, same_set)
4651 disk_stack_limits(mddev->gendisk, rdev->bdev,
4652 rdev->data_offset << 9);
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08004653
Linus Torvalds1da177e2005-04-16 15:20:36 -07004654 return 0;
4655abort:
NeilBrowne0cf8f02009-03-31 14:39:39 +11004656 md_unregister_thread(mddev->thread);
NeilBrown91adb562009-03-31 14:39:39 +11004657 mddev->thread = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004658 if (conf) {
4659 print_raid5_conf(conf);
Dan Williams95fc17a2009-07-31 12:39:15 +10004660 free_conf(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004661 }
4662 mddev->private = NULL;
4663 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4664 return -EIO;
4665}
4666
4667
4668
NeilBrown3f294f42005-11-08 21:39:25 -08004669static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004670{
4671 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4672
4673 md_unregister_thread(mddev->thread);
4674 mddev->thread = NULL;
NeilBrown041ae522007-03-26 21:32:14 -08004675 mddev->queue->backing_dev_info.congested_fn = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004676 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
NeilBrown007583c2005-11-08 21:39:30 -08004677 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
Dan Williams95fc17a2009-07-31 12:39:15 +10004678 free_conf(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004679 mddev->private = NULL;
4680 return 0;
4681}
4682
Dan Williams45b42332007-07-09 11:56:43 -07004683#ifdef DEBUG
NeilBrownd710e132008-10-13 11:55:12 +11004684static void print_sh(struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004685{
4686 int i;
4687
NeilBrown16a53ec2006-06-26 00:27:38 -07004688 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4689 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4690 seq_printf(seq, "sh %llu, count %d.\n",
4691 (unsigned long long)sh->sector, atomic_read(&sh->count));
4692 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08004693 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004694 seq_printf(seq, "(cache%d: %p %ld) ",
4695 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004696 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004697 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004698}
4699
NeilBrownd710e132008-10-13 11:55:12 +11004700static void printall(struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004701{
4702 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08004703 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004704 int i;
4705
4706 spin_lock_irq(&conf->device_lock);
4707 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08004708 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004709 if (sh->raid_conf != conf)
4710 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07004711 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004712 }
4713 }
4714 spin_unlock_irq(&conf->device_lock);
4715}
4716#endif
4717
NeilBrownd710e132008-10-13 11:55:12 +11004718static void status(struct seq_file *seq, mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004719{
4720 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4721 int i;
4722
Andre Noll9d8f0362009-06-18 08:45:01 +10004723 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
4724 mddev->chunk_sectors / 2, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07004725 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004726 for (i = 0; i < conf->raid_disks; i++)
4727 seq_printf (seq, "%s",
4728 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08004729 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004730 seq_printf (seq, "]");
Dan Williams45b42332007-07-09 11:56:43 -07004731#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004732 seq_printf (seq, "\n");
4733 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004734#endif
4735}
4736
4737static void print_raid5_conf (raid5_conf_t *conf)
4738{
4739 int i;
4740 struct disk_info *tmp;
4741
4742 printk("RAID5 conf printout:\n");
4743 if (!conf) {
4744 printk("(conf==NULL)\n");
4745 return;
4746 }
NeilBrown02c2de82006-10-03 01:15:47 -07004747 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4748 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004749
4750 for (i = 0; i < conf->raid_disks; i++) {
4751 char b[BDEVNAME_SIZE];
4752 tmp = conf->disks + i;
4753 if (tmp->rdev)
4754 printk(" disk %d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08004755 i, !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07004756 bdevname(tmp->rdev->bdev,b));
4757 }
4758}
4759
4760static int raid5_spare_active(mddev_t *mddev)
4761{
4762 int i;
4763 raid5_conf_t *conf = mddev->private;
4764 struct disk_info *tmp;
4765
4766 for (i = 0; i < conf->raid_disks; i++) {
4767 tmp = conf->disks + i;
4768 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08004769 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07004770 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4771 unsigned long flags;
4772 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004773 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07004774 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004775 }
4776 }
4777 print_raid5_conf(conf);
4778 return 0;
4779}
4780
4781static int raid5_remove_disk(mddev_t *mddev, int number)
4782{
4783 raid5_conf_t *conf = mddev->private;
4784 int err = 0;
4785 mdk_rdev_t *rdev;
4786 struct disk_info *p = conf->disks + number;
4787
4788 print_raid5_conf(conf);
4789 rdev = p->rdev;
4790 if (rdev) {
NeilBrownec32a2b2009-03-31 15:17:38 +11004791 if (number >= conf->raid_disks &&
4792 conf->reshape_progress == MaxSector)
4793 clear_bit(In_sync, &rdev->flags);
4794
NeilBrownb2d444d2005-11-08 21:39:31 -08004795 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07004796 atomic_read(&rdev->nr_pending)) {
4797 err = -EBUSY;
4798 goto abort;
4799 }
NeilBrowndfc70642008-05-23 13:04:39 -07004800 /* Only remove non-faulty devices if recovery
4801 * isn't possible.
4802 */
4803 if (!test_bit(Faulty, &rdev->flags) &&
NeilBrownec32a2b2009-03-31 15:17:38 +11004804 mddev->degraded <= conf->max_degraded &&
4805 number < conf->raid_disks) {
NeilBrowndfc70642008-05-23 13:04:39 -07004806 err = -EBUSY;
4807 goto abort;
4808 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004809 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07004810 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004811 if (atomic_read(&rdev->nr_pending)) {
4812 /* lost the race, try later */
4813 err = -EBUSY;
4814 p->rdev = rdev;
4815 }
4816 }
4817abort:
4818
4819 print_raid5_conf(conf);
4820 return err;
4821}
4822
4823static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4824{
4825 raid5_conf_t *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10004826 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004827 int disk;
4828 struct disk_info *p;
Neil Brown6c2fce22008-06-28 08:31:31 +10004829 int first = 0;
4830 int last = conf->raid_disks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004831
NeilBrown16a53ec2006-06-26 00:27:38 -07004832 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004833 /* no point adding a device */
Neil Brown199050e2008-06-28 08:31:33 +10004834 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004835
Neil Brown6c2fce22008-06-28 08:31:31 +10004836 if (rdev->raid_disk >= 0)
4837 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004838
4839 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004840 * find the disk ... but prefer rdev->saved_raid_disk
4841 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004842 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004843 if (rdev->saved_raid_disk >= 0 &&
Neil Brown6c2fce22008-06-28 08:31:31 +10004844 rdev->saved_raid_disk >= first &&
NeilBrown16a53ec2006-06-26 00:27:38 -07004845 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4846 disk = rdev->saved_raid_disk;
4847 else
Neil Brown6c2fce22008-06-28 08:31:31 +10004848 disk = first;
4849 for ( ; disk <= last ; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004850 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004851 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004852 rdev->raid_disk = disk;
Neil Brown199050e2008-06-28 08:31:33 +10004853 err = 0;
NeilBrown72626682005-09-09 16:23:54 -07004854 if (rdev->saved_raid_disk != disk)
4855 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08004856 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004857 break;
4858 }
4859 print_raid5_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10004860 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004861}
4862
4863static int raid5_resize(mddev_t *mddev, sector_t sectors)
4864{
4865 /* no resync is happening, and there is enough space
4866 * on all devices, so we can resize.
4867 * We need to make sure resync covers any new space.
4868 * If the array is shrinking we should possibly wait until
4869 * any io in the removed space completes, but it hardly seems
4870 * worth it.
4871 */
Andre Noll9d8f0362009-06-18 08:45:01 +10004872 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
Dan Williams1f403622009-03-31 14:59:03 +11004873 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
4874 mddev->raid_disks));
Dan Williamsb522adc2009-03-31 15:00:31 +11004875 if (mddev->array_sectors >
4876 raid5_size(mddev, sectors, mddev->raid_disks))
4877 return -EINVAL;
Andre Nollf233ea52008-07-21 17:05:22 +10004878 set_capacity(mddev->gendisk, mddev->array_sectors);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004879 mddev->changed = 1;
NeilBrown449aad32009-08-03 10:59:58 +10004880 revalidate_disk(mddev->gendisk);
Andre Noll58c0fed2009-03-31 14:33:13 +11004881 if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
4882 mddev->recovery_cp = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004883 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4884 }
Andre Noll58c0fed2009-03-31 14:33:13 +11004885 mddev->dev_sectors = sectors;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07004886 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004887 return 0;
4888}
4889
NeilBrown01ee22b2009-06-18 08:47:20 +10004890static int check_stripe_cache(mddev_t *mddev)
4891{
4892 /* Can only proceed if there are plenty of stripe_heads.
4893 * We need a minimum of one full stripe,, and for sensible progress
4894 * it is best to have about 4 times that.
4895 * If we require 4 times, then the default 256 4K stripe_heads will
4896 * allow for chunk sizes up to 256K, which is probably OK.
4897 * If the chunk size is greater, user-space should request more
4898 * stripe_heads first.
4899 */
4900 raid5_conf_t *conf = mddev->private;
4901 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
4902 > conf->max_nr_stripes ||
4903 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
4904 > conf->max_nr_stripes) {
4905 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
4906 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
4907 / STRIPE_SIZE)*4);
4908 return 0;
4909 }
4910 return 1;
4911}
4912
NeilBrown50ac1682009-06-18 08:47:55 +10004913static int check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08004914{
NeilBrown070ec552009-06-16 16:54:21 +10004915 raid5_conf_t *conf = mddev->private;
NeilBrown29269552006-03-27 01:18:10 -08004916
NeilBrown88ce4932009-03-31 15:24:23 +11004917 if (mddev->delta_disks == 0 &&
4918 mddev->new_layout == mddev->layout &&
Andre Noll664e7c42009-06-18 08:45:27 +10004919 mddev->new_chunk_sectors == mddev->chunk_sectors)
NeilBrown50ac1682009-06-18 08:47:55 +10004920 return 0; /* nothing to do */
NeilBrowndba034e2008-08-05 15:54:13 +10004921 if (mddev->bitmap)
4922 /* Cannot grow a bitmap yet */
4923 return -EBUSY;
NeilBrownec32a2b2009-03-31 15:17:38 +11004924 if (mddev->degraded > conf->max_degraded)
4925 return -EINVAL;
4926 if (mddev->delta_disks < 0) {
4927 /* We might be able to shrink, but the devices must
4928 * be made bigger first.
4929 * For raid6, 4 is the minimum size.
4930 * Otherwise 2 is the minimum
4931 */
4932 int min = 2;
4933 if (mddev->level == 6)
4934 min = 4;
4935 if (mddev->raid_disks + mddev->delta_disks < min)
4936 return -EINVAL;
4937 }
NeilBrown29269552006-03-27 01:18:10 -08004938
NeilBrown01ee22b2009-06-18 08:47:20 +10004939 if (!check_stripe_cache(mddev))
NeilBrown29269552006-03-27 01:18:10 -08004940 return -ENOSPC;
NeilBrown29269552006-03-27 01:18:10 -08004941
NeilBrownec32a2b2009-03-31 15:17:38 +11004942 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
NeilBrown63c70c42006-03-27 01:18:13 -08004943}
4944
4945static int raid5_start_reshape(mddev_t *mddev)
4946{
NeilBrown070ec552009-06-16 16:54:21 +10004947 raid5_conf_t *conf = mddev->private;
NeilBrown63c70c42006-03-27 01:18:13 -08004948 mdk_rdev_t *rdev;
NeilBrown63c70c42006-03-27 01:18:13 -08004949 int spares = 0;
4950 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07004951 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08004952
NeilBrownf4168852007-02-28 20:11:53 -08004953 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
NeilBrown63c70c42006-03-27 01:18:13 -08004954 return -EBUSY;
4955
NeilBrown01ee22b2009-06-18 08:47:20 +10004956 if (!check_stripe_cache(mddev))
4957 return -ENOSPC;
4958
Cheng Renquan159ec1f2009-01-09 08:31:08 +11004959 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08004960 if (rdev->raid_disk < 0 &&
4961 !test_bit(Faulty, &rdev->flags))
4962 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08004963
NeilBrownf4168852007-02-28 20:11:53 -08004964 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
NeilBrown29269552006-03-27 01:18:10 -08004965 /* Not enough devices even to make a degraded array
4966 * of that size
4967 */
4968 return -EINVAL;
4969
NeilBrownec32a2b2009-03-31 15:17:38 +11004970 /* Refuse to reduce size of the array. Any reductions in
4971 * array size must be through explicit setting of array_size
4972 * attribute.
4973 */
4974 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
4975 < mddev->array_sectors) {
4976 printk(KERN_ERR "md: %s: array size must be reduced "
4977 "before number of disks\n", mdname(mddev));
4978 return -EINVAL;
4979 }
4980
NeilBrownf6705572006-03-27 01:18:11 -08004981 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08004982 spin_lock_irq(&conf->device_lock);
4983 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08004984 conf->raid_disks += mddev->delta_disks;
Andre Noll09c9e5f2009-06-18 08:45:55 +10004985 conf->prev_chunk_sectors = conf->chunk_sectors;
4986 conf->chunk_sectors = mddev->new_chunk_sectors;
NeilBrown88ce4932009-03-31 15:24:23 +11004987 conf->prev_algo = conf->algorithm;
4988 conf->algorithm = mddev->new_layout;
NeilBrownfef9c612009-03-31 15:16:46 +11004989 if (mddev->delta_disks < 0)
4990 conf->reshape_progress = raid5_size(mddev, 0, 0);
4991 else
4992 conf->reshape_progress = 0;
4993 conf->reshape_safe = conf->reshape_progress;
NeilBrown86b42c72009-03-31 15:19:03 +11004994 conf->generation++;
NeilBrown29269552006-03-27 01:18:10 -08004995 spin_unlock_irq(&conf->device_lock);
4996
4997 /* Add some new drives, as many as will fit.
4998 * We know there are enough to make the newly sized array work.
4999 */
Cheng Renquan159ec1f2009-01-09 08:31:08 +11005000 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08005001 if (rdev->raid_disk < 0 &&
5002 !test_bit(Faulty, &rdev->flags)) {
Neil Brown199050e2008-06-28 08:31:33 +10005003 if (raid5_add_disk(mddev, rdev) == 0) {
NeilBrown29269552006-03-27 01:18:10 -08005004 char nm[20];
5005 set_bit(In_sync, &rdev->flags);
NeilBrown29269552006-03-27 01:18:10 -08005006 added_devices++;
NeilBrown5fd6c1d2006-06-26 00:27:40 -07005007 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08005008 sprintf(nm, "rd%d", rdev->raid_disk);
NeilBrown5e55e2f2007-03-26 21:32:14 -08005009 if (sysfs_create_link(&mddev->kobj,
5010 &rdev->kobj, nm))
5011 printk(KERN_WARNING
5012 "raid5: failed to create "
5013 " link %s for %s\n",
5014 nm, mdname(mddev));
NeilBrown29269552006-03-27 01:18:10 -08005015 } else
5016 break;
5017 }
5018
NeilBrownec32a2b2009-03-31 15:17:38 +11005019 if (mddev->delta_disks > 0) {
5020 spin_lock_irqsave(&conf->device_lock, flags);
5021 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks)
5022 - added_devices;
5023 spin_unlock_irqrestore(&conf->device_lock, flags);
5024 }
NeilBrown63c70c42006-03-27 01:18:13 -08005025 mddev->raid_disks = conf->raid_disks;
NeilBrowne5164022009-08-03 10:59:57 +10005026 mddev->reshape_position = conf->reshape_progress;
NeilBrown850b2b42006-10-03 01:15:46 -07005027 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08005028
NeilBrown29269552006-03-27 01:18:10 -08005029 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5030 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5031 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5032 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5033 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5034 "%s_reshape");
5035 if (!mddev->sync_thread) {
5036 mddev->recovery = 0;
5037 spin_lock_irq(&conf->device_lock);
5038 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11005039 conf->reshape_progress = MaxSector;
NeilBrown29269552006-03-27 01:18:10 -08005040 spin_unlock_irq(&conf->device_lock);
5041 return -EAGAIN;
5042 }
NeilBrownc8f517c2009-03-31 15:28:40 +11005043 conf->reshape_checkpoint = jiffies;
NeilBrown29269552006-03-27 01:18:10 -08005044 md_wakeup_thread(mddev->sync_thread);
5045 md_new_event(mddev);
5046 return 0;
5047}
NeilBrown29269552006-03-27 01:18:10 -08005048
NeilBrownec32a2b2009-03-31 15:17:38 +11005049/* This is called from the reshape thread and should make any
5050 * changes needed in 'conf'
5051 */
NeilBrown29269552006-03-27 01:18:10 -08005052static void end_reshape(raid5_conf_t *conf)
5053{
NeilBrown29269552006-03-27 01:18:10 -08005054
NeilBrownf6705572006-03-27 01:18:11 -08005055 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
Dan Williams80c3a6c2009-03-17 18:10:40 -07005056
NeilBrownf6705572006-03-27 01:18:11 -08005057 spin_lock_irq(&conf->device_lock);
NeilBrowncea9c222009-03-31 15:15:05 +11005058 conf->previous_raid_disks = conf->raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11005059 conf->reshape_progress = MaxSector;
NeilBrownf6705572006-03-27 01:18:11 -08005060 spin_unlock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11005061 wake_up(&conf->wait_for_overlap);
NeilBrown16a53ec2006-06-26 00:27:38 -07005062
5063 /* read-ahead size must cover two whole stripes, which is
5064 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5065 */
5066 {
NeilBrowncea9c222009-03-31 15:15:05 +11005067 int data_disks = conf->raid_disks - conf->max_degraded;
Andre Noll09c9e5f2009-06-18 08:45:55 +10005068 int stripe = data_disks * ((conf->chunk_sectors << 9)
NeilBrowncea9c222009-03-31 15:15:05 +11005069 / PAGE_SIZE);
NeilBrown16a53ec2006-06-26 00:27:38 -07005070 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5071 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5072 }
NeilBrown29269552006-03-27 01:18:10 -08005073 }
NeilBrown29269552006-03-27 01:18:10 -08005074}
5075
NeilBrownec32a2b2009-03-31 15:17:38 +11005076/* This is called from the raid5d thread with mddev_lock held.
5077 * It makes config changes to the device.
5078 */
NeilBrowncea9c222009-03-31 15:15:05 +11005079static void raid5_finish_reshape(mddev_t *mddev)
5080{
NeilBrown070ec552009-06-16 16:54:21 +10005081 raid5_conf_t *conf = mddev->private;
NeilBrowncea9c222009-03-31 15:15:05 +11005082
5083 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5084
NeilBrownec32a2b2009-03-31 15:17:38 +11005085 if (mddev->delta_disks > 0) {
5086 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5087 set_capacity(mddev->gendisk, mddev->array_sectors);
5088 mddev->changed = 1;
NeilBrown449aad32009-08-03 10:59:58 +10005089 revalidate_disk(mddev->gendisk);
NeilBrownec32a2b2009-03-31 15:17:38 +11005090 } else {
5091 int d;
NeilBrownec32a2b2009-03-31 15:17:38 +11005092 mddev->degraded = conf->raid_disks;
5093 for (d = 0; d < conf->raid_disks ; d++)
5094 if (conf->disks[d].rdev &&
5095 test_bit(In_sync,
5096 &conf->disks[d].rdev->flags))
5097 mddev->degraded--;
5098 for (d = conf->raid_disks ;
5099 d < conf->raid_disks - mddev->delta_disks;
NeilBrown1a67dde2009-08-13 10:41:49 +10005100 d++) {
5101 mdk_rdev_t *rdev = conf->disks[d].rdev;
5102 if (rdev && raid5_remove_disk(mddev, d) == 0) {
5103 char nm[20];
5104 sprintf(nm, "rd%d", rdev->raid_disk);
5105 sysfs_remove_link(&mddev->kobj, nm);
5106 rdev->raid_disk = -1;
5107 }
5108 }
NeilBrowncea9c222009-03-31 15:15:05 +11005109 }
NeilBrown88ce4932009-03-31 15:24:23 +11005110 mddev->layout = conf->algorithm;
Andre Noll09c9e5f2009-06-18 08:45:55 +10005111 mddev->chunk_sectors = conf->chunk_sectors;
NeilBrownec32a2b2009-03-31 15:17:38 +11005112 mddev->reshape_position = MaxSector;
5113 mddev->delta_disks = 0;
NeilBrowncea9c222009-03-31 15:15:05 +11005114 }
5115}
5116
NeilBrown72626682005-09-09 16:23:54 -07005117static void raid5_quiesce(mddev_t *mddev, int state)
5118{
NeilBrown070ec552009-06-16 16:54:21 +10005119 raid5_conf_t *conf = mddev->private;
NeilBrown72626682005-09-09 16:23:54 -07005120
5121 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08005122 case 2: /* resume for a suspend */
5123 wake_up(&conf->wait_for_overlap);
5124 break;
5125
NeilBrown72626682005-09-09 16:23:54 -07005126 case 1: /* stop all writes */
5127 spin_lock_irq(&conf->device_lock);
NeilBrown64bd6602009-08-03 10:59:58 +10005128 /* '2' tells resync/reshape to pause so that all
5129 * active stripes can drain
5130 */
5131 conf->quiesce = 2;
NeilBrown72626682005-09-09 16:23:54 -07005132 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08005133 atomic_read(&conf->active_stripes) == 0 &&
5134 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07005135 conf->device_lock, /* nothing */);
NeilBrown64bd6602009-08-03 10:59:58 +10005136 conf->quiesce = 1;
NeilBrown72626682005-09-09 16:23:54 -07005137 spin_unlock_irq(&conf->device_lock);
NeilBrown64bd6602009-08-03 10:59:58 +10005138 /* allow reshape to continue */
5139 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07005140 break;
5141
5142 case 0: /* re-enable writes */
5143 spin_lock_irq(&conf->device_lock);
5144 conf->quiesce = 0;
5145 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08005146 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07005147 spin_unlock_irq(&conf->device_lock);
5148 break;
5149 }
NeilBrown72626682005-09-09 16:23:54 -07005150}
NeilBrownb15c2e52006-01-06 00:20:16 -08005151
NeilBrownd562b0c2009-03-31 14:39:39 +11005152
5153static void *raid5_takeover_raid1(mddev_t *mddev)
5154{
5155 int chunksect;
5156
5157 if (mddev->raid_disks != 2 ||
5158 mddev->degraded > 1)
5159 return ERR_PTR(-EINVAL);
5160
5161 /* Should check if there are write-behind devices? */
5162
5163 chunksect = 64*2; /* 64K by default */
5164
5165 /* The array must be an exact multiple of chunksize */
5166 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5167 chunksect >>= 1;
5168
5169 if ((chunksect<<9) < STRIPE_SIZE)
5170 /* array size does not allow a suitable chunk size */
5171 return ERR_PTR(-EINVAL);
5172
5173 mddev->new_level = 5;
5174 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
Andre Noll664e7c42009-06-18 08:45:27 +10005175 mddev->new_chunk_sectors = chunksect;
NeilBrownd562b0c2009-03-31 14:39:39 +11005176
5177 return setup_conf(mddev);
5178}
5179
NeilBrownfc9739c2009-03-31 14:57:20 +11005180static void *raid5_takeover_raid6(mddev_t *mddev)
5181{
5182 int new_layout;
5183
5184 switch (mddev->layout) {
5185 case ALGORITHM_LEFT_ASYMMETRIC_6:
5186 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5187 break;
5188 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5189 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5190 break;
5191 case ALGORITHM_LEFT_SYMMETRIC_6:
5192 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5193 break;
5194 case ALGORITHM_RIGHT_SYMMETRIC_6:
5195 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5196 break;
5197 case ALGORITHM_PARITY_0_6:
5198 new_layout = ALGORITHM_PARITY_0;
5199 break;
5200 case ALGORITHM_PARITY_N:
5201 new_layout = ALGORITHM_PARITY_N;
5202 break;
5203 default:
5204 return ERR_PTR(-EINVAL);
5205 }
5206 mddev->new_level = 5;
5207 mddev->new_layout = new_layout;
5208 mddev->delta_disks = -1;
5209 mddev->raid_disks -= 1;
5210 return setup_conf(mddev);
5211}
5212
NeilBrownd562b0c2009-03-31 14:39:39 +11005213
NeilBrown50ac1682009-06-18 08:47:55 +10005214static int raid5_check_reshape(mddev_t *mddev)
NeilBrownb3546032009-03-31 14:56:41 +11005215{
NeilBrown88ce4932009-03-31 15:24:23 +11005216 /* For a 2-drive array, the layout and chunk size can be changed
5217 * immediately as not restriping is needed.
5218 * For larger arrays we record the new value - after validation
5219 * to be used by a reshape pass.
NeilBrownb3546032009-03-31 14:56:41 +11005220 */
NeilBrown070ec552009-06-16 16:54:21 +10005221 raid5_conf_t *conf = mddev->private;
NeilBrown597a7112009-06-18 08:47:42 +10005222 int new_chunk = mddev->new_chunk_sectors;
NeilBrownb3546032009-03-31 14:56:41 +11005223
NeilBrown597a7112009-06-18 08:47:42 +10005224 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
NeilBrownb3546032009-03-31 14:56:41 +11005225 return -EINVAL;
5226 if (new_chunk > 0) {
Andre Noll0ba459d2009-06-18 08:46:10 +10005227 if (!is_power_of_2(new_chunk))
NeilBrownb3546032009-03-31 14:56:41 +11005228 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005229 if (new_chunk < (PAGE_SIZE>>9))
NeilBrownb3546032009-03-31 14:56:41 +11005230 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005231 if (mddev->array_sectors & (new_chunk-1))
NeilBrownb3546032009-03-31 14:56:41 +11005232 /* not factor of array size */
5233 return -EINVAL;
5234 }
5235
5236 /* They look valid */
5237
NeilBrown88ce4932009-03-31 15:24:23 +11005238 if (mddev->raid_disks == 2) {
NeilBrown597a7112009-06-18 08:47:42 +10005239 /* can make the change immediately */
5240 if (mddev->new_layout >= 0) {
5241 conf->algorithm = mddev->new_layout;
5242 mddev->layout = mddev->new_layout;
NeilBrown88ce4932009-03-31 15:24:23 +11005243 }
5244 if (new_chunk > 0) {
NeilBrown597a7112009-06-18 08:47:42 +10005245 conf->chunk_sectors = new_chunk ;
5246 mddev->chunk_sectors = new_chunk;
NeilBrown88ce4932009-03-31 15:24:23 +11005247 }
5248 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5249 md_wakeup_thread(mddev->thread);
NeilBrownb3546032009-03-31 14:56:41 +11005250 }
NeilBrown50ac1682009-06-18 08:47:55 +10005251 return check_reshape(mddev);
NeilBrown88ce4932009-03-31 15:24:23 +11005252}
5253
NeilBrown50ac1682009-06-18 08:47:55 +10005254static int raid6_check_reshape(mddev_t *mddev)
NeilBrown88ce4932009-03-31 15:24:23 +11005255{
NeilBrown597a7112009-06-18 08:47:42 +10005256 int new_chunk = mddev->new_chunk_sectors;
NeilBrown50ac1682009-06-18 08:47:55 +10005257
NeilBrown597a7112009-06-18 08:47:42 +10005258 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
NeilBrown88ce4932009-03-31 15:24:23 +11005259 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005260 if (new_chunk > 0) {
Andre Noll0ba459d2009-06-18 08:46:10 +10005261 if (!is_power_of_2(new_chunk))
NeilBrown88ce4932009-03-31 15:24:23 +11005262 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005263 if (new_chunk < (PAGE_SIZE >> 9))
NeilBrown88ce4932009-03-31 15:24:23 +11005264 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005265 if (mddev->array_sectors & (new_chunk-1))
NeilBrown88ce4932009-03-31 15:24:23 +11005266 /* not factor of array size */
5267 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005268 }
NeilBrown88ce4932009-03-31 15:24:23 +11005269
5270 /* They look valid */
NeilBrown50ac1682009-06-18 08:47:55 +10005271 return check_reshape(mddev);
NeilBrownb3546032009-03-31 14:56:41 +11005272}
5273
NeilBrownd562b0c2009-03-31 14:39:39 +11005274static void *raid5_takeover(mddev_t *mddev)
5275{
5276 /* raid5 can take over:
5277 * raid0 - if all devices are the same - make it a raid4 layout
5278 * raid1 - if there are two drives. We need to know the chunk size
5279 * raid4 - trivial - just use a raid4 layout.
5280 * raid6 - Providing it is a *_6 layout
NeilBrownd562b0c2009-03-31 14:39:39 +11005281 */
5282
5283 if (mddev->level == 1)
5284 return raid5_takeover_raid1(mddev);
NeilBrowne9d47582009-03-31 14:57:09 +11005285 if (mddev->level == 4) {
5286 mddev->new_layout = ALGORITHM_PARITY_N;
5287 mddev->new_level = 5;
5288 return setup_conf(mddev);
5289 }
NeilBrownfc9739c2009-03-31 14:57:20 +11005290 if (mddev->level == 6)
5291 return raid5_takeover_raid6(mddev);
NeilBrownd562b0c2009-03-31 14:39:39 +11005292
5293 return ERR_PTR(-EINVAL);
5294}
5295
5296
NeilBrown245f46c2009-03-31 14:39:39 +11005297static struct mdk_personality raid5_personality;
5298
5299static void *raid6_takeover(mddev_t *mddev)
5300{
5301 /* Currently can only take over a raid5. We map the
5302 * personality to an equivalent raid6 personality
5303 * with the Q block at the end.
5304 */
5305 int new_layout;
5306
5307 if (mddev->pers != &raid5_personality)
5308 return ERR_PTR(-EINVAL);
5309 if (mddev->degraded > 1)
5310 return ERR_PTR(-EINVAL);
5311 if (mddev->raid_disks > 253)
5312 return ERR_PTR(-EINVAL);
5313 if (mddev->raid_disks < 3)
5314 return ERR_PTR(-EINVAL);
5315
5316 switch (mddev->layout) {
5317 case ALGORITHM_LEFT_ASYMMETRIC:
5318 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5319 break;
5320 case ALGORITHM_RIGHT_ASYMMETRIC:
5321 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5322 break;
5323 case ALGORITHM_LEFT_SYMMETRIC:
5324 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5325 break;
5326 case ALGORITHM_RIGHT_SYMMETRIC:
5327 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5328 break;
5329 case ALGORITHM_PARITY_0:
5330 new_layout = ALGORITHM_PARITY_0_6;
5331 break;
5332 case ALGORITHM_PARITY_N:
5333 new_layout = ALGORITHM_PARITY_N;
5334 break;
5335 default:
5336 return ERR_PTR(-EINVAL);
5337 }
5338 mddev->new_level = 6;
5339 mddev->new_layout = new_layout;
5340 mddev->delta_disks = 1;
5341 mddev->raid_disks += 1;
5342 return setup_conf(mddev);
5343}
5344
5345
NeilBrown16a53ec2006-06-26 00:27:38 -07005346static struct mdk_personality raid6_personality =
5347{
5348 .name = "raid6",
5349 .level = 6,
5350 .owner = THIS_MODULE,
5351 .make_request = make_request,
5352 .run = run,
5353 .stop = stop,
5354 .status = status,
5355 .error_handler = error,
5356 .hot_add_disk = raid5_add_disk,
5357 .hot_remove_disk= raid5_remove_disk,
5358 .spare_active = raid5_spare_active,
5359 .sync_request = sync_request,
5360 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005361 .size = raid5_size,
NeilBrown50ac1682009-06-18 08:47:55 +10005362 .check_reshape = raid6_check_reshape,
NeilBrownf4168852007-02-28 20:11:53 -08005363 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005364 .finish_reshape = raid5_finish_reshape,
NeilBrown16a53ec2006-06-26 00:27:38 -07005365 .quiesce = raid5_quiesce,
NeilBrown245f46c2009-03-31 14:39:39 +11005366 .takeover = raid6_takeover,
NeilBrown16a53ec2006-06-26 00:27:38 -07005367};
NeilBrown2604b702006-01-06 00:20:36 -08005368static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005369{
5370 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08005371 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005372 .owner = THIS_MODULE,
5373 .make_request = make_request,
5374 .run = run,
5375 .stop = stop,
5376 .status = status,
5377 .error_handler = error,
5378 .hot_add_disk = raid5_add_disk,
5379 .hot_remove_disk= raid5_remove_disk,
5380 .spare_active = raid5_spare_active,
5381 .sync_request = sync_request,
5382 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005383 .size = raid5_size,
NeilBrown63c70c42006-03-27 01:18:13 -08005384 .check_reshape = raid5_check_reshape,
5385 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005386 .finish_reshape = raid5_finish_reshape,
NeilBrown72626682005-09-09 16:23:54 -07005387 .quiesce = raid5_quiesce,
NeilBrownd562b0c2009-03-31 14:39:39 +11005388 .takeover = raid5_takeover,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005389};
5390
NeilBrown2604b702006-01-06 00:20:36 -08005391static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005392{
NeilBrown2604b702006-01-06 00:20:36 -08005393 .name = "raid4",
5394 .level = 4,
5395 .owner = THIS_MODULE,
5396 .make_request = make_request,
5397 .run = run,
5398 .stop = stop,
5399 .status = status,
5400 .error_handler = error,
5401 .hot_add_disk = raid5_add_disk,
5402 .hot_remove_disk= raid5_remove_disk,
5403 .spare_active = raid5_spare_active,
5404 .sync_request = sync_request,
5405 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005406 .size = raid5_size,
NeilBrown3d378902007-03-26 21:32:13 -08005407 .check_reshape = raid5_check_reshape,
5408 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005409 .finish_reshape = raid5_finish_reshape,
NeilBrown2604b702006-01-06 00:20:36 -08005410 .quiesce = raid5_quiesce,
5411};
5412
5413static int __init raid5_init(void)
5414{
NeilBrown16a53ec2006-06-26 00:27:38 -07005415 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005416 register_md_personality(&raid5_personality);
5417 register_md_personality(&raid4_personality);
5418 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005419}
5420
NeilBrown2604b702006-01-06 00:20:36 -08005421static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005422{
NeilBrown16a53ec2006-06-26 00:27:38 -07005423 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005424 unregister_md_personality(&raid5_personality);
5425 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005426}
5427
5428module_init(raid5_init);
5429module_exit(raid5_exit);
5430MODULE_LICENSE("GPL");
5431MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08005432MODULE_ALIAS("md-raid5");
5433MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08005434MODULE_ALIAS("md-level-5");
5435MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07005436MODULE_ALIAS("md-personality-8"); /* RAID6 */
5437MODULE_ALIAS("md-raid6");
5438MODULE_ALIAS("md-level-6");
5439
5440/* This used to be two separate modules, they were: */
5441MODULE_ALIAS("raid5");
5442MODULE_ALIAS("raid6");