blob: 54c8ee28fcc4940517262389b16d4de1030709f3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
NeilBrown16a53ec2006-06-26 00:27:38 -07005 * Copyright (C) 2002, 2003 H. Peter Anvin
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
NeilBrown16a53ec2006-06-26 00:27:38 -07007 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
NeilBrownae3c20c2006-07-10 04:44:17 -070021/*
22 * BITMAP UNPLUGGING:
23 *
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
26 * explanation.
27 *
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->bm_write is the number of the last batch successfully written.
31 * conf->bm_flush is the number of the last batch that was closed to
32 * new additions.
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is bm_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
39 * batch.
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
43 * miss any bits.
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/module.h>
47#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/highmem.h>
49#include <linux/bitops.h>
NeilBrownf6705572006-03-27 01:18:11 -080050#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <asm/atomic.h>
NeilBrown16a53ec2006-06-26 00:27:38 -070052#include "raid6.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
NeilBrown72626682005-09-09 16:23:54 -070054#include <linux/raid/bitmap.h>
Dan Williams91c00922007-01-02 13:52:30 -070055#include <linux/async_tx.h>
NeilBrown72626682005-09-09 16:23:54 -070056
Linus Torvalds1da177e2005-04-16 15:20:36 -070057/*
58 * Stripe cache
59 */
60
61#define NR_STRIPES 256
62#define STRIPE_SIZE PAGE_SIZE
63#define STRIPE_SHIFT (PAGE_SHIFT - 9)
64#define STRIPE_SECTORS (STRIPE_SIZE>>9)
65#define IO_THRESHOLD 1
Dan Williams8b3e6cd2008-04-28 02:15:53 -070066#define BYPASS_THRESHOLD 1
NeilBrownfccddba2006-01-06 00:20:33 -080067#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#define HASH_MASK (NR_HASH - 1)
69
NeilBrownfccddba2006-01-06 00:20:33 -080070#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72/* bio's attached to a stripe+device for I/O are linked together in bi_sector
73 * order without overlap. There may be several bio's per stripe+device, and
74 * a bio could span several devices.
75 * When walking this list for a particular stripe+device, we must never proceed
76 * beyond a bio that extends past this device, as the next bio might no longer
77 * be valid.
78 * This macro is used to determine the 'next' bio in the list, given the sector
79 * of the current stripe+device
80 */
81#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
82/*
83 * The following can be used to debug the driver
84 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#define RAID5_PARANOIA 1
86#if RAID5_PARANOIA && defined(CONFIG_SMP)
87# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
88#else
89# define CHECK_DEVLOCK()
90#endif
91
Dan Williams45b42332007-07-09 11:56:43 -070092#ifdef DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070093#define inline
94#define __inline__
95#endif
96
Bernd Schubert6be9d492008-05-23 13:04:34 -070097#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
98
NeilBrown16a53ec2006-06-26 00:27:38 -070099#if !RAID6_USE_EMPTY_ZERO_PAGE
100/* In .bss so it's zeroed */
101const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
102#endif
103
104static inline int raid6_next_disk(int disk, int raid_disks)
105{
106 disk++;
107 return (disk < raid_disks) ? disk : 0;
108}
Dan Williamsa4456852007-07-09 11:56:43 -0700109
110static void return_io(struct bio *return_bi)
111{
112 struct bio *bi = return_bi;
113 while (bi) {
Dan Williamsa4456852007-07-09 11:56:43 -0700114
115 return_bi = bi->bi_next;
116 bi->bi_next = NULL;
117 bi->bi_size = 0;
NeilBrown6712ecf2007-09-27 12:47:43 +0200118 bi->bi_end_io(bi,
Dan Williamsa4456852007-07-09 11:56:43 -0700119 test_bit(BIO_UPTODATE, &bi->bi_flags)
120 ? 0 : -EIO);
121 bi = return_bi;
122 }
123}
124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125static void print_raid5_conf (raid5_conf_t *conf);
126
Arjan van de Ven858119e2006-01-14 13:20:43 -0800127static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
129 if (atomic_dec_and_test(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200130 BUG_ON(!list_empty(&sh->lru));
131 BUG_ON(atomic_read(&conf->active_stripes)==0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 if (test_bit(STRIPE_HANDLE, &sh->state)) {
NeilBrown7c785b72006-07-10 04:44:16 -0700133 if (test_bit(STRIPE_DELAYED, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 list_add_tail(&sh->lru, &conf->delayed_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700135 blk_plug_device(conf->mddev->queue);
136 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
NeilBrownae3c20c2006-07-10 04:44:17 -0700137 sh->bm_seq - conf->seq_write > 0) {
NeilBrown72626682005-09-09 16:23:54 -0700138 list_add_tail(&sh->lru, &conf->bitmap_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700139 blk_plug_device(conf->mddev->queue);
140 } else {
NeilBrown72626682005-09-09 16:23:54 -0700141 clear_bit(STRIPE_BIT_DELAY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 list_add_tail(&sh->lru, &conf->handle_list);
NeilBrown72626682005-09-09 16:23:54 -0700143 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 md_wakeup_thread(conf->mddev->thread);
145 } else {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700146 BUG_ON(sh->ops.pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
148 atomic_dec(&conf->preread_active_stripes);
149 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
150 md_wakeup_thread(conf->mddev->thread);
151 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 atomic_dec(&conf->active_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800153 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
154 list_add_tail(&sh->lru, &conf->inactive_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 wake_up(&conf->wait_for_stripe);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -0800156 if (conf->retry_read_aligned)
157 md_wakeup_thread(conf->mddev->thread);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800158 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 }
160 }
161}
162static void release_stripe(struct stripe_head *sh)
163{
164 raid5_conf_t *conf = sh->raid_conf;
165 unsigned long flags;
NeilBrown16a53ec2006-06-26 00:27:38 -0700166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 spin_lock_irqsave(&conf->device_lock, flags);
168 __release_stripe(conf, sh);
169 spin_unlock_irqrestore(&conf->device_lock, flags);
170}
171
NeilBrownfccddba2006-01-06 00:20:33 -0800172static inline void remove_hash(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Dan Williams45b42332007-07-09 11:56:43 -0700174 pr_debug("remove_hash(), stripe %llu\n",
175 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
NeilBrownfccddba2006-01-06 00:20:33 -0800177 hlist_del_init(&sh->hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178}
179
NeilBrown16a53ec2006-06-26 00:27:38 -0700180static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
NeilBrownfccddba2006-01-06 00:20:33 -0800182 struct hlist_head *hp = stripe_hash(conf, sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Dan Williams45b42332007-07-09 11:56:43 -0700184 pr_debug("insert_hash(), stripe %llu\n",
185 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187 CHECK_DEVLOCK();
NeilBrownfccddba2006-01-06 00:20:33 -0800188 hlist_add_head(&sh->hash, hp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
191
192/* find an idle stripe, make sure it is unhashed, and return it. */
193static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
194{
195 struct stripe_head *sh = NULL;
196 struct list_head *first;
197
198 CHECK_DEVLOCK();
199 if (list_empty(&conf->inactive_list))
200 goto out;
201 first = conf->inactive_list.next;
202 sh = list_entry(first, struct stripe_head, lru);
203 list_del_init(first);
204 remove_hash(sh);
205 atomic_inc(&conf->active_stripes);
206out:
207 return sh;
208}
209
210static void shrink_buffers(struct stripe_head *sh, int num)
211{
212 struct page *p;
213 int i;
214
215 for (i=0; i<num ; i++) {
216 p = sh->dev[i].page;
217 if (!p)
218 continue;
219 sh->dev[i].page = NULL;
NeilBrown2d1f3b52006-01-06 00:20:31 -0800220 put_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
222}
223
224static int grow_buffers(struct stripe_head *sh, int num)
225{
226 int i;
227
228 for (i=0; i<num; i++) {
229 struct page *page;
230
231 if (!(page = alloc_page(GFP_KERNEL))) {
232 return 1;
233 }
234 sh->dev[i].page = page;
235 }
236 return 0;
237}
238
239static void raid5_build_block (struct stripe_head *sh, int i);
240
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800241static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800244 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200246 BUG_ON(atomic_read(&sh->count) != 0);
247 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
Dan Williamsd84e0f12007-01-02 13:52:30 -0700248 BUG_ON(sh->ops.pending || sh->ops.ack || sh->ops.complete);
249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700251 pr_debug("init_stripe called, stripe %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 (unsigned long long)sh->sector);
253
254 remove_hash(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -0700255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 sh->sector = sector;
257 sh->pd_idx = pd_idx;
258 sh->state = 0;
259
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800260 sh->disks = disks;
261
262 for (i = sh->disks; i--; ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 struct r5dev *dev = &sh->dev[i];
264
Dan Williamsd84e0f12007-01-02 13:52:30 -0700265 if (dev->toread || dev->read || dev->towrite || dev->written ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 test_bit(R5_LOCKED, &dev->flags)) {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700267 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 (unsigned long long)sh->sector, i, dev->toread,
Dan Williamsd84e0f12007-01-02 13:52:30 -0700269 dev->read, dev->towrite, dev->written,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 test_bit(R5_LOCKED, &dev->flags));
271 BUG();
272 }
273 dev->flags = 0;
274 raid5_build_block(sh, i);
275 }
276 insert_hash(conf, sh);
277}
278
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800279static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280{
281 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -0800282 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700285 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
NeilBrownfccddba2006-01-06 00:20:33 -0800286 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800287 if (sh->sector == sector && sh->disks == disks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 return sh;
Dan Williams45b42332007-07-09 11:56:43 -0700289 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 return NULL;
291}
292
293static void unplug_slaves(mddev_t *mddev);
Jens Axboe165125e2007-07-24 09:28:11 +0200294static void raid5_unplug_device(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800296static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
297 int pd_idx, int noblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298{
299 struct stripe_head *sh;
300
Dan Williams45b42332007-07-09 11:56:43 -0700301 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
303 spin_lock_irq(&conf->device_lock);
304
305 do {
NeilBrown72626682005-09-09 16:23:54 -0700306 wait_event_lock_irq(conf->wait_for_stripe,
307 conf->quiesce == 0,
308 conf->device_lock, /* nothing */);
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800309 sh = __find_stripe(conf, sector, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 if (!sh) {
311 if (!conf->inactive_blocked)
312 sh = get_free_stripe(conf);
313 if (noblock && sh == NULL)
314 break;
315 if (!sh) {
316 conf->inactive_blocked = 1;
317 wait_event_lock_irq(conf->wait_for_stripe,
318 !list_empty(&conf->inactive_list) &&
NeilBrown50368052005-12-12 02:39:17 -0800319 (atomic_read(&conf->active_stripes)
320 < (conf->max_nr_stripes *3/4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 || !conf->inactive_blocked),
322 conf->device_lock,
NeilBrownf4370782006-07-10 04:44:14 -0700323 raid5_unplug_device(conf->mddev->queue)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 );
325 conf->inactive_blocked = 0;
326 } else
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800327 init_stripe(sh, sector, pd_idx, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 } else {
329 if (atomic_read(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200330 BUG_ON(!list_empty(&sh->lru));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 } else {
332 if (!test_bit(STRIPE_HANDLE, &sh->state))
333 atomic_inc(&conf->active_stripes);
NeilBrownff4e8d92006-07-10 04:44:16 -0700334 if (list_empty(&sh->lru) &&
335 !test_bit(STRIPE_EXPANDING, &sh->state))
NeilBrown16a53ec2006-06-26 00:27:38 -0700336 BUG();
337 list_del_init(&sh->lru);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 }
339 }
340 } while (sh == NULL);
341
342 if (sh)
343 atomic_inc(&sh->count);
344
345 spin_unlock_irq(&conf->device_lock);
346 return sh;
347}
348
Dan Williamsd84e0f12007-01-02 13:52:30 -0700349/* test_and_ack_op() ensures that we only dequeue an operation once */
350#define test_and_ack_op(op, pend) \
351do { \
352 if (test_bit(op, &sh->ops.pending) && \
353 !test_bit(op, &sh->ops.complete)) { \
354 if (test_and_set_bit(op, &sh->ops.ack)) \
355 clear_bit(op, &pend); \
356 else \
357 ack++; \
358 } else \
359 clear_bit(op, &pend); \
360} while (0)
361
362/* find new work to run, do not resubmit work that is already
363 * in flight
364 */
365static unsigned long get_stripe_work(struct stripe_head *sh)
366{
367 unsigned long pending;
368 int ack = 0;
369
370 pending = sh->ops.pending;
371
372 test_and_ack_op(STRIPE_OP_BIOFILL, pending);
373 test_and_ack_op(STRIPE_OP_COMPUTE_BLK, pending);
374 test_and_ack_op(STRIPE_OP_PREXOR, pending);
375 test_and_ack_op(STRIPE_OP_BIODRAIN, pending);
376 test_and_ack_op(STRIPE_OP_POSTXOR, pending);
377 test_and_ack_op(STRIPE_OP_CHECK, pending);
378 if (test_and_clear_bit(STRIPE_OP_IO, &sh->ops.pending))
379 ack++;
380
381 sh->ops.count -= ack;
Dan Williams4ae3f842007-10-22 20:45:11 -0700382 if (unlikely(sh->ops.count < 0)) {
383 printk(KERN_ERR "pending: %#lx ops.pending: %#lx ops.ack: %#lx "
384 "ops.complete: %#lx\n", pending, sh->ops.pending,
385 sh->ops.ack, sh->ops.complete);
386 BUG();
387 }
Dan Williamsd84e0f12007-01-02 13:52:30 -0700388
389 return pending;
390}
391
NeilBrown6712ecf2007-09-27 12:47:43 +0200392static void
393raid5_end_read_request(struct bio *bi, int error);
394static void
395raid5_end_write_request(struct bio *bi, int error);
Dan Williams91c00922007-01-02 13:52:30 -0700396
397static void ops_run_io(struct stripe_head *sh)
398{
399 raid5_conf_t *conf = sh->raid_conf;
400 int i, disks = sh->disks;
401
402 might_sleep();
403
Dan Williams8b3e6cd2008-04-28 02:15:53 -0700404 set_bit(STRIPE_IO_STARTED, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700405 for (i = disks; i--; ) {
406 int rw;
407 struct bio *bi;
408 mdk_rdev_t *rdev;
409 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
410 rw = WRITE;
411 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
412 rw = READ;
413 else
414 continue;
415
416 bi = &sh->dev[i].req;
417
418 bi->bi_rw = rw;
419 if (rw == WRITE)
420 bi->bi_end_io = raid5_end_write_request;
421 else
422 bi->bi_end_io = raid5_end_read_request;
423
424 rcu_read_lock();
425 rdev = rcu_dereference(conf->disks[i].rdev);
426 if (rdev && test_bit(Faulty, &rdev->flags))
427 rdev = NULL;
428 if (rdev)
429 atomic_inc(&rdev->nr_pending);
430 rcu_read_unlock();
431
432 if (rdev) {
433 if (test_bit(STRIPE_SYNCING, &sh->state) ||
434 test_bit(STRIPE_EXPAND_SOURCE, &sh->state) ||
435 test_bit(STRIPE_EXPAND_READY, &sh->state))
436 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
437
438 bi->bi_bdev = rdev->bdev;
439 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700440 __func__, (unsigned long long)sh->sector,
Dan Williams91c00922007-01-02 13:52:30 -0700441 bi->bi_rw, i);
442 atomic_inc(&sh->count);
443 bi->bi_sector = sh->sector + rdev->data_offset;
444 bi->bi_flags = 1 << BIO_UPTODATE;
445 bi->bi_vcnt = 1;
446 bi->bi_max_vecs = 1;
447 bi->bi_idx = 0;
448 bi->bi_io_vec = &sh->dev[i].vec;
449 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
450 bi->bi_io_vec[0].bv_offset = 0;
451 bi->bi_size = STRIPE_SIZE;
452 bi->bi_next = NULL;
453 if (rw == WRITE &&
454 test_bit(R5_ReWrite, &sh->dev[i].flags))
455 atomic_add(STRIPE_SECTORS,
456 &rdev->corrected_errors);
457 generic_make_request(bi);
458 } else {
459 if (rw == WRITE)
460 set_bit(STRIPE_DEGRADED, &sh->state);
461 pr_debug("skip op %ld on disc %d for sector %llu\n",
462 bi->bi_rw, i, (unsigned long long)sh->sector);
463 clear_bit(R5_LOCKED, &sh->dev[i].flags);
464 set_bit(STRIPE_HANDLE, &sh->state);
465 }
466 }
467}
468
469static struct dma_async_tx_descriptor *
470async_copy_data(int frombio, struct bio *bio, struct page *page,
471 sector_t sector, struct dma_async_tx_descriptor *tx)
472{
473 struct bio_vec *bvl;
474 struct page *bio_page;
475 int i;
476 int page_offset;
477
478 if (bio->bi_sector >= sector)
479 page_offset = (signed)(bio->bi_sector - sector) * 512;
480 else
481 page_offset = (signed)(sector - bio->bi_sector) * -512;
482 bio_for_each_segment(bvl, bio, i) {
483 int len = bio_iovec_idx(bio, i)->bv_len;
484 int clen;
485 int b_offset = 0;
486
487 if (page_offset < 0) {
488 b_offset = -page_offset;
489 page_offset += b_offset;
490 len -= b_offset;
491 }
492
493 if (len > 0 && page_offset + len > STRIPE_SIZE)
494 clen = STRIPE_SIZE - page_offset;
495 else
496 clen = len;
497
498 if (clen > 0) {
499 b_offset += bio_iovec_idx(bio, i)->bv_offset;
500 bio_page = bio_iovec_idx(bio, i)->bv_page;
501 if (frombio)
502 tx = async_memcpy(page, bio_page, page_offset,
503 b_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700504 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700505 tx, NULL, NULL);
506 else
507 tx = async_memcpy(bio_page, page, b_offset,
508 page_offset, clen,
Dan Williamseb0645a2007-07-20 00:31:46 -0700509 ASYNC_TX_DEP_ACK,
Dan Williams91c00922007-01-02 13:52:30 -0700510 tx, NULL, NULL);
511 }
512 if (clen < len) /* hit end of page */
513 break;
514 page_offset += len;
515 }
516
517 return tx;
518}
519
520static void ops_complete_biofill(void *stripe_head_ref)
521{
522 struct stripe_head *sh = stripe_head_ref;
523 struct bio *return_bi = NULL;
524 raid5_conf_t *conf = sh->raid_conf;
Dan Williamse4d84902007-09-24 10:06:13 -0700525 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700526
Harvey Harrisone46b2722008-04-28 02:15:50 -0700527 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700528 (unsigned long long)sh->sector);
529
530 /* clear completed biofills */
531 for (i = sh->disks; i--; ) {
532 struct r5dev *dev = &sh->dev[i];
Dan Williams91c00922007-01-02 13:52:30 -0700533
534 /* acknowledge completion of a biofill operation */
Dan Williamse4d84902007-09-24 10:06:13 -0700535 /* and check if we need to reply to a read request,
536 * new R5_Wantfill requests are held off until
537 * !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)
538 */
539 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700540 struct bio *rbi, *rbi2;
Dan Williams91c00922007-01-02 13:52:30 -0700541
542 /* The access to dev->read is outside of the
543 * spin_lock_irq(&conf->device_lock), but is protected
544 * by the STRIPE_OP_BIOFILL pending bit
545 */
546 BUG_ON(!dev->read);
547 rbi = dev->read;
548 dev->read = NULL;
549 while (rbi && rbi->bi_sector <
550 dev->sector + STRIPE_SECTORS) {
551 rbi2 = r5_next_bio(rbi, dev->sector);
552 spin_lock_irq(&conf->device_lock);
553 if (--rbi->bi_phys_segments == 0) {
554 rbi->bi_next = return_bi;
555 return_bi = rbi;
556 }
557 spin_unlock_irq(&conf->device_lock);
558 rbi = rbi2;
559 }
560 }
561 }
Dan Williams4ae3f842007-10-22 20:45:11 -0700562 set_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
Dan Williams91c00922007-01-02 13:52:30 -0700563
564 return_io(return_bi);
565
Dan Williamse4d84902007-09-24 10:06:13 -0700566 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700567 release_stripe(sh);
568}
569
570static void ops_run_biofill(struct stripe_head *sh)
571{
572 struct dma_async_tx_descriptor *tx = NULL;
573 raid5_conf_t *conf = sh->raid_conf;
574 int i;
575
Harvey Harrisone46b2722008-04-28 02:15:50 -0700576 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700577 (unsigned long long)sh->sector);
578
579 for (i = sh->disks; i--; ) {
580 struct r5dev *dev = &sh->dev[i];
581 if (test_bit(R5_Wantfill, &dev->flags)) {
582 struct bio *rbi;
583 spin_lock_irq(&conf->device_lock);
584 dev->read = rbi = dev->toread;
585 dev->toread = NULL;
586 spin_unlock_irq(&conf->device_lock);
587 while (rbi && rbi->bi_sector <
588 dev->sector + STRIPE_SECTORS) {
589 tx = async_copy_data(0, rbi, dev->page,
590 dev->sector, tx);
591 rbi = r5_next_bio(rbi, dev->sector);
592 }
593 }
594 }
595
596 atomic_inc(&sh->count);
597 async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
598 ops_complete_biofill, sh);
599}
600
601static void ops_complete_compute5(void *stripe_head_ref)
602{
603 struct stripe_head *sh = stripe_head_ref;
604 int target = sh->ops.target;
605 struct r5dev *tgt = &sh->dev[target];
606
Harvey Harrisone46b2722008-04-28 02:15:50 -0700607 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700608 (unsigned long long)sh->sector);
609
610 set_bit(R5_UPTODATE, &tgt->flags);
611 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
612 clear_bit(R5_Wantcompute, &tgt->flags);
613 set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
614 set_bit(STRIPE_HANDLE, &sh->state);
615 release_stripe(sh);
616}
617
618static struct dma_async_tx_descriptor *
619ops_run_compute5(struct stripe_head *sh, unsigned long pending)
620{
621 /* kernel stack size limits the total number of disks */
622 int disks = sh->disks;
623 struct page *xor_srcs[disks];
624 int target = sh->ops.target;
625 struct r5dev *tgt = &sh->dev[target];
626 struct page *xor_dest = tgt->page;
627 int count = 0;
628 struct dma_async_tx_descriptor *tx;
629 int i;
630
631 pr_debug("%s: stripe %llu block: %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700632 __func__, (unsigned long long)sh->sector, target);
Dan Williams91c00922007-01-02 13:52:30 -0700633 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
634
635 for (i = disks; i--; )
636 if (i != target)
637 xor_srcs[count++] = sh->dev[i].page;
638
639 atomic_inc(&sh->count);
640
641 if (unlikely(count == 1))
642 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
643 0, NULL, ops_complete_compute5, sh);
644 else
645 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
646 ASYNC_TX_XOR_ZERO_DST, NULL,
647 ops_complete_compute5, sh);
648
649 /* ack now if postxor is not set to be run */
650 if (tx && !test_bit(STRIPE_OP_POSTXOR, &pending))
651 async_tx_ack(tx);
652
653 return tx;
654}
655
656static void ops_complete_prexor(void *stripe_head_ref)
657{
658 struct stripe_head *sh = stripe_head_ref;
659
Harvey Harrisone46b2722008-04-28 02:15:50 -0700660 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700661 (unsigned long long)sh->sector);
662
663 set_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
664}
665
666static struct dma_async_tx_descriptor *
667ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
668{
669 /* kernel stack size limits the total number of disks */
670 int disks = sh->disks;
671 struct page *xor_srcs[disks];
672 int count = 0, pd_idx = sh->pd_idx, i;
673
674 /* existing parity data subtracted */
675 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
676
Harvey Harrisone46b2722008-04-28 02:15:50 -0700677 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700678 (unsigned long long)sh->sector);
679
680 for (i = disks; i--; ) {
681 struct r5dev *dev = &sh->dev[i];
682 /* Only process blocks that are known to be uptodate */
683 if (dev->towrite && test_bit(R5_Wantprexor, &dev->flags))
684 xor_srcs[count++] = dev->page;
685 }
686
687 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
688 ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
689 ops_complete_prexor, sh);
690
691 return tx;
692}
693
694static struct dma_async_tx_descriptor *
Dan Williams6c55be82007-11-14 16:59:35 -0800695ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
696 unsigned long pending)
Dan Williams91c00922007-01-02 13:52:30 -0700697{
698 int disks = sh->disks;
699 int pd_idx = sh->pd_idx, i;
700
701 /* check if prexor is active which means only process blocks
702 * that are part of a read-modify-write (Wantprexor)
703 */
Dan Williams6c55be82007-11-14 16:59:35 -0800704 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
Dan Williams91c00922007-01-02 13:52:30 -0700705
Harvey Harrisone46b2722008-04-28 02:15:50 -0700706 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700707 (unsigned long long)sh->sector);
708
709 for (i = disks; i--; ) {
710 struct r5dev *dev = &sh->dev[i];
711 struct bio *chosen;
712 int towrite;
713
714 towrite = 0;
715 if (prexor) { /* rmw */
716 if (dev->towrite &&
717 test_bit(R5_Wantprexor, &dev->flags))
718 towrite = 1;
719 } else { /* rcw */
720 if (i != pd_idx && dev->towrite &&
721 test_bit(R5_LOCKED, &dev->flags))
722 towrite = 1;
723 }
724
725 if (towrite) {
726 struct bio *wbi;
727
728 spin_lock(&sh->lock);
729 chosen = dev->towrite;
730 dev->towrite = NULL;
731 BUG_ON(dev->written);
732 wbi = dev->written = chosen;
733 spin_unlock(&sh->lock);
734
735 while (wbi && wbi->bi_sector <
736 dev->sector + STRIPE_SECTORS) {
737 tx = async_copy_data(1, wbi, dev->page,
738 dev->sector, tx);
739 wbi = r5_next_bio(wbi, dev->sector);
740 }
741 }
742 }
743
744 return tx;
745}
746
747static void ops_complete_postxor(void *stripe_head_ref)
748{
749 struct stripe_head *sh = stripe_head_ref;
750
Harvey Harrisone46b2722008-04-28 02:15:50 -0700751 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700752 (unsigned long long)sh->sector);
753
754 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
755 set_bit(STRIPE_HANDLE, &sh->state);
756 release_stripe(sh);
757}
758
759static void ops_complete_write(void *stripe_head_ref)
760{
761 struct stripe_head *sh = stripe_head_ref;
762 int disks = sh->disks, i, pd_idx = sh->pd_idx;
763
Harvey Harrisone46b2722008-04-28 02:15:50 -0700764 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700765 (unsigned long long)sh->sector);
766
767 for (i = disks; i--; ) {
768 struct r5dev *dev = &sh->dev[i];
769 if (dev->written || i == pd_idx)
770 set_bit(R5_UPTODATE, &dev->flags);
771 }
772
773 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
774 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
775
776 set_bit(STRIPE_HANDLE, &sh->state);
777 release_stripe(sh);
778}
779
780static void
Dan Williams6c55be82007-11-14 16:59:35 -0800781ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
782 unsigned long pending)
Dan Williams91c00922007-01-02 13:52:30 -0700783{
784 /* kernel stack size limits the total number of disks */
785 int disks = sh->disks;
786 struct page *xor_srcs[disks];
787
788 int count = 0, pd_idx = sh->pd_idx, i;
789 struct page *xor_dest;
Dan Williams6c55be82007-11-14 16:59:35 -0800790 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
Dan Williams91c00922007-01-02 13:52:30 -0700791 unsigned long flags;
792 dma_async_tx_callback callback;
793
Harvey Harrisone46b2722008-04-28 02:15:50 -0700794 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700795 (unsigned long long)sh->sector);
796
797 /* check if prexor is active which means only process blocks
798 * that are part of a read-modify-write (written)
799 */
800 if (prexor) {
801 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
802 for (i = disks; i--; ) {
803 struct r5dev *dev = &sh->dev[i];
804 if (dev->written)
805 xor_srcs[count++] = dev->page;
806 }
807 } else {
808 xor_dest = sh->dev[pd_idx].page;
809 for (i = disks; i--; ) {
810 struct r5dev *dev = &sh->dev[i];
811 if (i != pd_idx)
812 xor_srcs[count++] = dev->page;
813 }
814 }
815
816 /* check whether this postxor is part of a write */
Dan Williams6c55be82007-11-14 16:59:35 -0800817 callback = test_bit(STRIPE_OP_BIODRAIN, &pending) ?
Dan Williams91c00922007-01-02 13:52:30 -0700818 ops_complete_write : ops_complete_postxor;
819
820 /* 1/ if we prexor'd then the dest is reused as a source
821 * 2/ if we did not prexor then we are redoing the parity
822 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
823 * for the synchronous xor case
824 */
825 flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
826 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
827
828 atomic_inc(&sh->count);
829
830 if (unlikely(count == 1)) {
831 flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
832 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
833 flags, tx, callback, sh);
834 } else
835 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
836 flags, tx, callback, sh);
837}
838
839static void ops_complete_check(void *stripe_head_ref)
840{
841 struct stripe_head *sh = stripe_head_ref;
842 int pd_idx = sh->pd_idx;
843
Harvey Harrisone46b2722008-04-28 02:15:50 -0700844 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700845 (unsigned long long)sh->sector);
846
847 if (test_and_clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending) &&
848 sh->ops.zero_sum_result == 0)
849 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
850
851 set_bit(STRIPE_OP_CHECK, &sh->ops.complete);
852 set_bit(STRIPE_HANDLE, &sh->state);
853 release_stripe(sh);
854}
855
856static void ops_run_check(struct stripe_head *sh)
857{
858 /* kernel stack size limits the total number of disks */
859 int disks = sh->disks;
860 struct page *xor_srcs[disks];
861 struct dma_async_tx_descriptor *tx;
862
863 int count = 0, pd_idx = sh->pd_idx, i;
864 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
865
Harvey Harrisone46b2722008-04-28 02:15:50 -0700866 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700867 (unsigned long long)sh->sector);
868
869 for (i = disks; i--; ) {
870 struct r5dev *dev = &sh->dev[i];
871 if (i != pd_idx)
872 xor_srcs[count++] = dev->page;
873 }
874
875 tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
876 &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
877
878 if (tx)
879 set_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
880 else
881 clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
882
883 atomic_inc(&sh->count);
884 tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
885 ops_complete_check, sh);
886}
887
888static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
889{
890 int overlap_clear = 0, i, disks = sh->disks;
891 struct dma_async_tx_descriptor *tx = NULL;
892
893 if (test_bit(STRIPE_OP_BIOFILL, &pending)) {
894 ops_run_biofill(sh);
895 overlap_clear++;
896 }
897
898 if (test_bit(STRIPE_OP_COMPUTE_BLK, &pending))
899 tx = ops_run_compute5(sh, pending);
900
901 if (test_bit(STRIPE_OP_PREXOR, &pending))
902 tx = ops_run_prexor(sh, tx);
903
904 if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
Dan Williams6c55be82007-11-14 16:59:35 -0800905 tx = ops_run_biodrain(sh, tx, pending);
Dan Williams91c00922007-01-02 13:52:30 -0700906 overlap_clear++;
907 }
908
909 if (test_bit(STRIPE_OP_POSTXOR, &pending))
Dan Williams6c55be82007-11-14 16:59:35 -0800910 ops_run_postxor(sh, tx, pending);
Dan Williams91c00922007-01-02 13:52:30 -0700911
912 if (test_bit(STRIPE_OP_CHECK, &pending))
913 ops_run_check(sh);
914
915 if (test_bit(STRIPE_OP_IO, &pending))
916 ops_run_io(sh);
917
918 if (overlap_clear)
919 for (i = disks; i--; ) {
920 struct r5dev *dev = &sh->dev[i];
921 if (test_and_clear_bit(R5_Overlap, &dev->flags))
922 wake_up(&sh->raid_conf->wait_for_overlap);
923 }
924}
925
NeilBrown3f294f42005-11-08 21:39:25 -0800926static int grow_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927{
928 struct stripe_head *sh;
NeilBrown3f294f42005-11-08 21:39:25 -0800929 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
930 if (!sh)
931 return 0;
932 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
933 sh->raid_conf = conf;
934 spin_lock_init(&sh->lock);
935
936 if (grow_buffers(sh, conf->raid_disks)) {
937 shrink_buffers(sh, conf->raid_disks);
938 kmem_cache_free(conf->slab_cache, sh);
939 return 0;
940 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800941 sh->disks = conf->raid_disks;
NeilBrown3f294f42005-11-08 21:39:25 -0800942 /* we just created an active stripe so... */
943 atomic_set(&sh->count, 1);
944 atomic_inc(&conf->active_stripes);
945 INIT_LIST_HEAD(&sh->lru);
946 release_stripe(sh);
947 return 1;
948}
949
950static int grow_stripes(raid5_conf_t *conf, int num)
951{
Christoph Lametere18b8902006-12-06 20:33:20 -0800952 struct kmem_cache *sc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 int devs = conf->raid_disks;
954
NeilBrown42b9beb2007-05-09 02:35:37 -0700955 sprintf(conf->cache_name[0], "raid5-%s", mdname(conf->mddev));
956 sprintf(conf->cache_name[1], "raid5-%s-alt", mdname(conf->mddev));
NeilBrownad01c9e2006-03-27 01:18:07 -0800957 conf->active_name = 0;
958 sc = kmem_cache_create(conf->cache_name[conf->active_name],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +0900960 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (!sc)
962 return 1;
963 conf->slab_cache = sc;
NeilBrownad01c9e2006-03-27 01:18:07 -0800964 conf->pool_size = devs;
NeilBrown16a53ec2006-06-26 00:27:38 -0700965 while (num--)
NeilBrown3f294f42005-11-08 21:39:25 -0800966 if (!grow_one_stripe(conf))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 return 0;
969}
NeilBrown29269552006-03-27 01:18:10 -0800970
971#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrownad01c9e2006-03-27 01:18:07 -0800972static int resize_stripes(raid5_conf_t *conf, int newsize)
973{
974 /* Make all the stripes able to hold 'newsize' devices.
975 * New slots in each stripe get 'page' set to a new page.
976 *
977 * This happens in stages:
978 * 1/ create a new kmem_cache and allocate the required number of
979 * stripe_heads.
980 * 2/ gather all the old stripe_heads and tranfer the pages across
981 * to the new stripe_heads. This will have the side effect of
982 * freezing the array as once all stripe_heads have been collected,
983 * no IO will be possible. Old stripe heads are freed once their
984 * pages have been transferred over, and the old kmem_cache is
985 * freed when all stripes are done.
986 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
987 * we simple return a failre status - no need to clean anything up.
988 * 4/ allocate new pages for the new slots in the new stripe_heads.
989 * If this fails, we don't bother trying the shrink the
990 * stripe_heads down again, we just leave them as they are.
991 * As each stripe_head is processed the new one is released into
992 * active service.
993 *
994 * Once step2 is started, we cannot afford to wait for a write,
995 * so we use GFP_NOIO allocations.
996 */
997 struct stripe_head *osh, *nsh;
998 LIST_HEAD(newstripes);
999 struct disk_info *ndisks;
1000 int err = 0;
Christoph Lametere18b8902006-12-06 20:33:20 -08001001 struct kmem_cache *sc;
NeilBrownad01c9e2006-03-27 01:18:07 -08001002 int i;
1003
1004 if (newsize <= conf->pool_size)
1005 return 0; /* never bother to shrink */
1006
NeilBrown2a2275d2007-01-26 00:57:11 -08001007 md_allow_write(conf->mddev);
1008
NeilBrownad01c9e2006-03-27 01:18:07 -08001009 /* Step 1 */
1010 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1011 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +09001012 0, 0, NULL);
NeilBrownad01c9e2006-03-27 01:18:07 -08001013 if (!sc)
1014 return -ENOMEM;
1015
1016 for (i = conf->max_nr_stripes; i; i--) {
1017 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1018 if (!nsh)
1019 break;
1020
1021 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1022
1023 nsh->raid_conf = conf;
1024 spin_lock_init(&nsh->lock);
1025
1026 list_add(&nsh->lru, &newstripes);
1027 }
1028 if (i) {
1029 /* didn't get enough, give up */
1030 while (!list_empty(&newstripes)) {
1031 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1032 list_del(&nsh->lru);
1033 kmem_cache_free(sc, nsh);
1034 }
1035 kmem_cache_destroy(sc);
1036 return -ENOMEM;
1037 }
1038 /* Step 2 - Must use GFP_NOIO now.
1039 * OK, we have enough stripes, start collecting inactive
1040 * stripes and copying them over
1041 */
1042 list_for_each_entry(nsh, &newstripes, lru) {
1043 spin_lock_irq(&conf->device_lock);
1044 wait_event_lock_irq(conf->wait_for_stripe,
1045 !list_empty(&conf->inactive_list),
1046 conf->device_lock,
NeilBrownb3b46be2006-03-27 01:18:16 -08001047 unplug_slaves(conf->mddev)
NeilBrownad01c9e2006-03-27 01:18:07 -08001048 );
1049 osh = get_free_stripe(conf);
1050 spin_unlock_irq(&conf->device_lock);
1051 atomic_set(&nsh->count, 1);
1052 for(i=0; i<conf->pool_size; i++)
1053 nsh->dev[i].page = osh->dev[i].page;
1054 for( ; i<newsize; i++)
1055 nsh->dev[i].page = NULL;
1056 kmem_cache_free(conf->slab_cache, osh);
1057 }
1058 kmem_cache_destroy(conf->slab_cache);
1059
1060 /* Step 3.
1061 * At this point, we are holding all the stripes so the array
1062 * is completely stalled, so now is a good time to resize
1063 * conf->disks.
1064 */
1065 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1066 if (ndisks) {
1067 for (i=0; i<conf->raid_disks; i++)
1068 ndisks[i] = conf->disks[i];
1069 kfree(conf->disks);
1070 conf->disks = ndisks;
1071 } else
1072 err = -ENOMEM;
1073
1074 /* Step 4, return new stripes to service */
1075 while(!list_empty(&newstripes)) {
1076 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1077 list_del_init(&nsh->lru);
1078 for (i=conf->raid_disks; i < newsize; i++)
1079 if (nsh->dev[i].page == NULL) {
1080 struct page *p = alloc_page(GFP_NOIO);
1081 nsh->dev[i].page = p;
1082 if (!p)
1083 err = -ENOMEM;
1084 }
1085 release_stripe(nsh);
1086 }
1087 /* critical section pass, GFP_NOIO no longer needed */
1088
1089 conf->slab_cache = sc;
1090 conf->active_name = 1-conf->active_name;
1091 conf->pool_size = newsize;
1092 return err;
1093}
NeilBrown29269552006-03-27 01:18:10 -08001094#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095
NeilBrown3f294f42005-11-08 21:39:25 -08001096static int drop_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097{
1098 struct stripe_head *sh;
1099
NeilBrown3f294f42005-11-08 21:39:25 -08001100 spin_lock_irq(&conf->device_lock);
1101 sh = get_free_stripe(conf);
1102 spin_unlock_irq(&conf->device_lock);
1103 if (!sh)
1104 return 0;
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001105 BUG_ON(atomic_read(&sh->count));
NeilBrownad01c9e2006-03-27 01:18:07 -08001106 shrink_buffers(sh, conf->pool_size);
NeilBrown3f294f42005-11-08 21:39:25 -08001107 kmem_cache_free(conf->slab_cache, sh);
1108 atomic_dec(&conf->active_stripes);
1109 return 1;
1110}
1111
1112static void shrink_stripes(raid5_conf_t *conf)
1113{
1114 while (drop_one_stripe(conf))
1115 ;
1116
NeilBrown29fc7e32006-02-03 03:03:41 -08001117 if (conf->slab_cache)
1118 kmem_cache_destroy(conf->slab_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 conf->slab_cache = NULL;
1120}
1121
NeilBrown6712ecf2007-09-27 12:47:43 +02001122static void raid5_end_read_request(struct bio * bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123{
1124 struct stripe_head *sh = bi->bi_private;
1125 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001126 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
NeilBrownd6950432006-07-10 04:44:20 -07001128 char b[BDEVNAME_SIZE];
1129 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131
1132 for (i=0 ; i<disks; i++)
1133 if (bi == &sh->dev[i].req)
1134 break;
1135
Dan Williams45b42332007-07-09 11:56:43 -07001136 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1137 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 uptodate);
1139 if (i == disks) {
1140 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001141 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 }
1143
1144 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 set_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrown4e5314b2005-11-08 21:39:22 -08001146 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrownd6950432006-07-10 04:44:20 -07001147 rdev = conf->disks[i].rdev;
Bernd Schubert6be9d492008-05-23 13:04:34 -07001148 printk_rl(KERN_INFO "raid5:%s: read error corrected"
1149 " (%lu sectors at %llu on %s)\n",
1150 mdname(conf->mddev), STRIPE_SECTORS,
1151 (unsigned long long)(sh->sector
1152 + rdev->data_offset),
1153 bdevname(rdev->bdev, b));
NeilBrown4e5314b2005-11-08 21:39:22 -08001154 clear_bit(R5_ReadError, &sh->dev[i].flags);
1155 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1156 }
NeilBrownba22dcb2005-11-08 21:39:31 -08001157 if (atomic_read(&conf->disks[i].rdev->read_errors))
1158 atomic_set(&conf->disks[i].rdev->read_errors, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 } else {
NeilBrownd6950432006-07-10 04:44:20 -07001160 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
NeilBrownba22dcb2005-11-08 21:39:31 -08001161 int retry = 0;
NeilBrownd6950432006-07-10 04:44:20 -07001162 rdev = conf->disks[i].rdev;
1163
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001165 atomic_inc(&rdev->read_errors);
NeilBrownba22dcb2005-11-08 21:39:31 -08001166 if (conf->mddev->degraded)
Bernd Schubert6be9d492008-05-23 13:04:34 -07001167 printk_rl(KERN_WARNING
1168 "raid5:%s: read error not correctable "
1169 "(sector %llu on %s).\n",
1170 mdname(conf->mddev),
1171 (unsigned long long)(sh->sector
1172 + rdev->data_offset),
1173 bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001174 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
NeilBrown4e5314b2005-11-08 21:39:22 -08001175 /* Oh, no!!! */
Bernd Schubert6be9d492008-05-23 13:04:34 -07001176 printk_rl(KERN_WARNING
1177 "raid5:%s: read error NOT corrected!! "
1178 "(sector %llu on %s).\n",
1179 mdname(conf->mddev),
1180 (unsigned long long)(sh->sector
1181 + rdev->data_offset),
1182 bdn);
NeilBrownd6950432006-07-10 04:44:20 -07001183 else if (atomic_read(&rdev->read_errors)
NeilBrownba22dcb2005-11-08 21:39:31 -08001184 > conf->max_nr_stripes)
NeilBrown14f8d262006-01-06 00:20:14 -08001185 printk(KERN_WARNING
NeilBrownd6950432006-07-10 04:44:20 -07001186 "raid5:%s: Too many read errors, failing device %s.\n",
1187 mdname(conf->mddev), bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001188 else
1189 retry = 1;
1190 if (retry)
1191 set_bit(R5_ReadError, &sh->dev[i].flags);
1192 else {
NeilBrown4e5314b2005-11-08 21:39:22 -08001193 clear_bit(R5_ReadError, &sh->dev[i].flags);
1194 clear_bit(R5_ReWrite, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001195 md_error(conf->mddev, rdev);
NeilBrownba22dcb2005-11-08 21:39:31 -08001196 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 }
1198 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1200 set_bit(STRIPE_HANDLE, &sh->state);
1201 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202}
1203
NeilBrown6712ecf2007-09-27 12:47:43 +02001204static void raid5_end_write_request (struct bio *bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205{
1206 struct stripe_head *sh = bi->bi_private;
1207 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001208 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 for (i=0 ; i<disks; i++)
1212 if (bi == &sh->dev[i].req)
1213 break;
1214
Dan Williams45b42332007-07-09 11:56:43 -07001215 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1217 uptodate);
1218 if (i == disks) {
1219 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001220 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 }
1222
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 if (!uptodate)
1224 md_error(conf->mddev, conf->disks[i].rdev);
1225
1226 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1227
1228 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1229 set_bit(STRIPE_HANDLE, &sh->state);
NeilBrownc04be0a2006-10-03 01:15:53 -07001230 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231}
1232
1233
1234static sector_t compute_blocknr(struct stripe_head *sh, int i);
1235
1236static void raid5_build_block (struct stripe_head *sh, int i)
1237{
1238 struct r5dev *dev = &sh->dev[i];
1239
1240 bio_init(&dev->req);
1241 dev->req.bi_io_vec = &dev->vec;
1242 dev->req.bi_vcnt++;
1243 dev->req.bi_max_vecs++;
1244 dev->vec.bv_page = dev->page;
1245 dev->vec.bv_len = STRIPE_SIZE;
1246 dev->vec.bv_offset = 0;
1247
1248 dev->req.bi_sector = sh->sector;
1249 dev->req.bi_private = sh;
1250
1251 dev->flags = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001252 dev->sector = compute_blocknr(sh, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253}
1254
1255static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1256{
1257 char b[BDEVNAME_SIZE];
1258 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
Dan Williams45b42332007-07-09 11:56:43 -07001259 pr_debug("raid5: error called\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260
NeilBrownb2d444d2005-11-08 21:39:31 -08001261 if (!test_bit(Faulty, &rdev->flags)) {
NeilBrown850b2b42006-10-03 01:15:46 -07001262 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownc04be0a2006-10-03 01:15:53 -07001263 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1264 unsigned long flags;
1265 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001267 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 /*
1269 * if recovery was running, make sure it aborts.
1270 */
NeilBrowndfc70642008-05-23 13:04:39 -07001271 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001273 set_bit(Faulty, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 printk (KERN_ALERT
Nick Andrewd7a420c2008-04-28 02:15:55 -07001275 "raid5: Disk failure on %s, disabling device.\n"
1276 "raid5: Operation continuing on %d devices.\n",
NeilBrown02c2de82006-10-03 01:15:47 -07001277 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 }
NeilBrown16a53ec2006-06-26 00:27:38 -07001279}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280
1281/*
1282 * Input: a 'big' sector number,
1283 * Output: index of the data and parity disk, and the sector # in them.
1284 */
1285static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
1286 unsigned int data_disks, unsigned int * dd_idx,
1287 unsigned int * pd_idx, raid5_conf_t *conf)
1288{
1289 long stripe;
1290 unsigned long chunk_number;
1291 unsigned int chunk_offset;
1292 sector_t new_sector;
1293 int sectors_per_chunk = conf->chunk_size >> 9;
1294
1295 /* First compute the information on this sector */
1296
1297 /*
1298 * Compute the chunk number and the sector offset inside the chunk
1299 */
1300 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1301 chunk_number = r_sector;
1302 BUG_ON(r_sector != chunk_number);
1303
1304 /*
1305 * Compute the stripe number
1306 */
1307 stripe = chunk_number / data_disks;
1308
1309 /*
1310 * Compute the data disk and parity disk indexes inside the stripe
1311 */
1312 *dd_idx = chunk_number % data_disks;
1313
1314 /*
1315 * Select the parity disk based on the user selected algorithm.
1316 */
NeilBrown16a53ec2006-06-26 00:27:38 -07001317 switch(conf->level) {
1318 case 4:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 *pd_idx = data_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001320 break;
1321 case 5:
1322 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 case ALGORITHM_LEFT_ASYMMETRIC:
1324 *pd_idx = data_disks - stripe % raid_disks;
1325 if (*dd_idx >= *pd_idx)
1326 (*dd_idx)++;
1327 break;
1328 case ALGORITHM_RIGHT_ASYMMETRIC:
1329 *pd_idx = stripe % raid_disks;
1330 if (*dd_idx >= *pd_idx)
1331 (*dd_idx)++;
1332 break;
1333 case ALGORITHM_LEFT_SYMMETRIC:
1334 *pd_idx = data_disks - stripe % raid_disks;
1335 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1336 break;
1337 case ALGORITHM_RIGHT_SYMMETRIC:
1338 *pd_idx = stripe % raid_disks;
1339 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1340 break;
1341 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001342 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -07001344 }
1345 break;
1346 case 6:
1347
1348 /**** FIX THIS ****/
1349 switch (conf->algorithm) {
1350 case ALGORITHM_LEFT_ASYMMETRIC:
1351 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1352 if (*pd_idx == raid_disks-1)
1353 (*dd_idx)++; /* Q D D D P */
1354 else if (*dd_idx >= *pd_idx)
1355 (*dd_idx) += 2; /* D D P Q D */
1356 break;
1357 case ALGORITHM_RIGHT_ASYMMETRIC:
1358 *pd_idx = stripe % raid_disks;
1359 if (*pd_idx == raid_disks-1)
1360 (*dd_idx)++; /* Q D D D P */
1361 else if (*dd_idx >= *pd_idx)
1362 (*dd_idx) += 2; /* D D P Q D */
1363 break;
1364 case ALGORITHM_LEFT_SYMMETRIC:
1365 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1366 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1367 break;
1368 case ALGORITHM_RIGHT_SYMMETRIC:
1369 *pd_idx = stripe % raid_disks;
1370 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1371 break;
1372 default:
1373 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
1374 conf->algorithm);
1375 }
1376 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 }
1378
1379 /*
1380 * Finally, compute the new sector number
1381 */
1382 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1383 return new_sector;
1384}
1385
1386
1387static sector_t compute_blocknr(struct stripe_head *sh, int i)
1388{
1389 raid5_conf_t *conf = sh->raid_conf;
NeilBrownb875e532006-12-10 02:20:49 -08001390 int raid_disks = sh->disks;
1391 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 sector_t new_sector = sh->sector, check;
1393 int sectors_per_chunk = conf->chunk_size >> 9;
1394 sector_t stripe;
1395 int chunk_offset;
1396 int chunk_number, dummy1, dummy2, dd_idx = i;
1397 sector_t r_sector;
1398
NeilBrown16a53ec2006-06-26 00:27:38 -07001399
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1401 stripe = new_sector;
1402 BUG_ON(new_sector != stripe);
1403
NeilBrown16a53ec2006-06-26 00:27:38 -07001404 if (i == sh->pd_idx)
1405 return 0;
1406 switch(conf->level) {
1407 case 4: break;
1408 case 5:
1409 switch (conf->algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 case ALGORITHM_LEFT_ASYMMETRIC:
1411 case ALGORITHM_RIGHT_ASYMMETRIC:
1412 if (i > sh->pd_idx)
1413 i--;
1414 break;
1415 case ALGORITHM_LEFT_SYMMETRIC:
1416 case ALGORITHM_RIGHT_SYMMETRIC:
1417 if (i < sh->pd_idx)
1418 i += raid_disks;
1419 i -= (sh->pd_idx + 1);
1420 break;
1421 default:
NeilBrown14f8d262006-01-06 00:20:14 -08001422 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001423 conf->algorithm);
1424 }
1425 break;
1426 case 6:
NeilBrown16a53ec2006-06-26 00:27:38 -07001427 if (i == raid6_next_disk(sh->pd_idx, raid_disks))
1428 return 0; /* It is the Q disk */
1429 switch (conf->algorithm) {
1430 case ALGORITHM_LEFT_ASYMMETRIC:
1431 case ALGORITHM_RIGHT_ASYMMETRIC:
1432 if (sh->pd_idx == raid_disks-1)
1433 i--; /* Q D D D P */
1434 else if (i > sh->pd_idx)
1435 i -= 2; /* D D P Q D */
1436 break;
1437 case ALGORITHM_LEFT_SYMMETRIC:
1438 case ALGORITHM_RIGHT_SYMMETRIC:
1439 if (sh->pd_idx == raid_disks-1)
1440 i--; /* Q D D D P */
1441 else {
1442 /* D D P Q D */
1443 if (i < sh->pd_idx)
1444 i += raid_disks;
1445 i -= (sh->pd_idx + 2);
1446 }
1447 break;
1448 default:
1449 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450 conf->algorithm);
NeilBrown16a53ec2006-06-26 00:27:38 -07001451 }
1452 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 }
1454
1455 chunk_number = stripe * data_disks + i;
1456 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
1457
1458 check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
1459 if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
NeilBrown14f8d262006-01-06 00:20:14 -08001460 printk(KERN_ERR "compute_blocknr: map not correct\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 return 0;
1462 }
1463 return r_sector;
1464}
1465
1466
1467
1468/*
NeilBrown16a53ec2006-06-26 00:27:38 -07001469 * Copy data between a page in the stripe cache, and one or more bion
1470 * The page could align with the middle of the bio, or there could be
1471 * several bion, each with several bio_vecs, which cover part of the page
1472 * Multiple bion are linked together on bi_next. There may be extras
1473 * at the end of this list. We ignore them.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 */
1475static void copy_data(int frombio, struct bio *bio,
1476 struct page *page,
1477 sector_t sector)
1478{
1479 char *pa = page_address(page);
1480 struct bio_vec *bvl;
1481 int i;
1482 int page_offset;
1483
1484 if (bio->bi_sector >= sector)
1485 page_offset = (signed)(bio->bi_sector - sector) * 512;
1486 else
1487 page_offset = (signed)(sector - bio->bi_sector) * -512;
1488 bio_for_each_segment(bvl, bio, i) {
1489 int len = bio_iovec_idx(bio,i)->bv_len;
1490 int clen;
1491 int b_offset = 0;
1492
1493 if (page_offset < 0) {
1494 b_offset = -page_offset;
1495 page_offset += b_offset;
1496 len -= b_offset;
1497 }
1498
1499 if (len > 0 && page_offset + len > STRIPE_SIZE)
1500 clen = STRIPE_SIZE - page_offset;
1501 else clen = len;
NeilBrown16a53ec2006-06-26 00:27:38 -07001502
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 if (clen > 0) {
1504 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
1505 if (frombio)
1506 memcpy(pa+page_offset, ba+b_offset, clen);
1507 else
1508 memcpy(ba+b_offset, pa+page_offset, clen);
1509 __bio_kunmap_atomic(ba, KM_USER0);
1510 }
1511 if (clen < len) /* hit end of page */
1512 break;
1513 page_offset += len;
1514 }
1515}
1516
Dan Williams9bc89cd2007-01-02 11:10:44 -07001517#define check_xor() do { \
1518 if (count == MAX_XOR_BLOCKS) { \
1519 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1520 count = 0; \
1521 } \
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522 } while(0)
1523
NeilBrown16a53ec2006-06-26 00:27:38 -07001524static void compute_parity6(struct stripe_head *sh, int method)
1525{
1526 raid6_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08001527 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
NeilBrown16a53ec2006-06-26 00:27:38 -07001528 struct bio *chosen;
1529 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1530 void *ptrs[disks];
1531
1532 qd_idx = raid6_next_disk(pd_idx, disks);
1533 d0_idx = raid6_next_disk(qd_idx, disks);
1534
Dan Williams45b42332007-07-09 11:56:43 -07001535 pr_debug("compute_parity, stripe %llu, method %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001536 (unsigned long long)sh->sector, method);
1537
1538 switch(method) {
1539 case READ_MODIFY_WRITE:
1540 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1541 case RECONSTRUCT_WRITE:
1542 for (i= disks; i-- ;)
1543 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1544 chosen = sh->dev[i].towrite;
1545 sh->dev[i].towrite = NULL;
1546
1547 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1548 wake_up(&conf->wait_for_overlap);
1549
Eric Sesterhenn52e5f9d2006-10-03 23:33:23 +02001550 BUG_ON(sh->dev[i].written);
NeilBrown16a53ec2006-06-26 00:27:38 -07001551 sh->dev[i].written = chosen;
1552 }
1553 break;
1554 case CHECK_PARITY:
1555 BUG(); /* Not implemented yet */
1556 }
1557
1558 for (i = disks; i--;)
1559 if (sh->dev[i].written) {
1560 sector_t sector = sh->dev[i].sector;
1561 struct bio *wbi = sh->dev[i].written;
1562 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1563 copy_data(1, wbi, sh->dev[i].page, sector);
1564 wbi = r5_next_bio(wbi, sector);
1565 }
1566
1567 set_bit(R5_LOCKED, &sh->dev[i].flags);
1568 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1569 }
1570
1571// switch(method) {
1572// case RECONSTRUCT_WRITE:
1573// case CHECK_PARITY:
1574// case UPDATE_PARITY:
1575 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1576 /* FIX: Is this ordering of drives even remotely optimal? */
1577 count = 0;
1578 i = d0_idx;
1579 do {
1580 ptrs[count++] = page_address(sh->dev[i].page);
1581 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1582 printk("block %d/%d not uptodate on parity calc\n", i,count);
1583 i = raid6_next_disk(i, disks);
1584 } while ( i != d0_idx );
1585// break;
1586// }
1587
1588 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
1589
1590 switch(method) {
1591 case RECONSTRUCT_WRITE:
1592 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1593 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1594 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1595 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1596 break;
1597 case UPDATE_PARITY:
1598 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1599 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1600 break;
1601 }
1602}
1603
1604
1605/* Compute one missing block */
1606static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1607{
NeilBrownf4168852007-02-28 20:11:53 -08001608 int i, count, disks = sh->disks;
Dan Williams9bc89cd2007-01-02 11:10:44 -07001609 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
NeilBrown16a53ec2006-06-26 00:27:38 -07001610 int pd_idx = sh->pd_idx;
1611 int qd_idx = raid6_next_disk(pd_idx, disks);
1612
Dan Williams45b42332007-07-09 11:56:43 -07001613 pr_debug("compute_block_1, stripe %llu, idx %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001614 (unsigned long long)sh->sector, dd_idx);
1615
1616 if ( dd_idx == qd_idx ) {
1617 /* We're actually computing the Q drive */
1618 compute_parity6(sh, UPDATE_PARITY);
1619 } else {
Dan Williams9bc89cd2007-01-02 11:10:44 -07001620 dest = page_address(sh->dev[dd_idx].page);
1621 if (!nozero) memset(dest, 0, STRIPE_SIZE);
1622 count = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001623 for (i = disks ; i--; ) {
1624 if (i == dd_idx || i == qd_idx)
1625 continue;
1626 p = page_address(sh->dev[i].page);
1627 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1628 ptr[count++] = p;
1629 else
1630 printk("compute_block() %d, stripe %llu, %d"
1631 " not present\n", dd_idx,
1632 (unsigned long long)sh->sector, i);
1633
1634 check_xor();
1635 }
Dan Williams9bc89cd2007-01-02 11:10:44 -07001636 if (count)
1637 xor_blocks(count, STRIPE_SIZE, dest, ptr);
NeilBrown16a53ec2006-06-26 00:27:38 -07001638 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1639 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1640 }
1641}
1642
1643/* Compute two missing blocks */
1644static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1645{
NeilBrownf4168852007-02-28 20:11:53 -08001646 int i, count, disks = sh->disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001647 int pd_idx = sh->pd_idx;
1648 int qd_idx = raid6_next_disk(pd_idx, disks);
1649 int d0_idx = raid6_next_disk(qd_idx, disks);
1650 int faila, failb;
1651
1652 /* faila and failb are disk numbers relative to d0_idx */
1653 /* pd_idx become disks-2 and qd_idx become disks-1 */
1654 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
1655 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
1656
1657 BUG_ON(faila == failb);
1658 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1659
Dan Williams45b42332007-07-09 11:56:43 -07001660 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07001661 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
1662
1663 if ( failb == disks-1 ) {
1664 /* Q disk is one of the missing disks */
1665 if ( faila == disks-2 ) {
1666 /* Missing P+Q, just recompute */
1667 compute_parity6(sh, UPDATE_PARITY);
1668 return;
1669 } else {
1670 /* We're missing D+Q; recompute D from P */
1671 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0);
1672 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1673 return;
1674 }
1675 }
1676
1677 /* We're missing D+P or D+D; build pointer table */
1678 {
1679 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1680 void *ptrs[disks];
1681
1682 count = 0;
1683 i = d0_idx;
1684 do {
1685 ptrs[count++] = page_address(sh->dev[i].page);
1686 i = raid6_next_disk(i, disks);
1687 if (i != dd_idx1 && i != dd_idx2 &&
1688 !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1689 printk("compute_2 with missing block %d/%d\n", count, i);
1690 } while ( i != d0_idx );
1691
1692 if ( failb == disks-2 ) {
1693 /* We're missing D+P. */
1694 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
1695 } else {
1696 /* We're missing D+D. */
1697 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
1698 }
1699
1700 /* Both the above update both missing blocks */
1701 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1702 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1703 }
1704}
1705
Dan Williamse33129d2007-01-02 13:52:30 -07001706static int
1707handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
1708{
1709 int i, pd_idx = sh->pd_idx, disks = sh->disks;
1710 int locked = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001711
Dan Williamse33129d2007-01-02 13:52:30 -07001712 if (rcw) {
1713 /* if we are not expanding this is a proper write request, and
1714 * there will be bios with new data to be drained into the
1715 * stripe cache
1716 */
1717 if (!expand) {
1718 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
1719 sh->ops.count++;
1720 }
1721
1722 set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
1723 sh->ops.count++;
1724
1725 for (i = disks; i--; ) {
1726 struct r5dev *dev = &sh->dev[i];
1727
1728 if (dev->towrite) {
1729 set_bit(R5_LOCKED, &dev->flags);
1730 if (!expand)
1731 clear_bit(R5_UPTODATE, &dev->flags);
1732 locked++;
1733 }
1734 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07001735 if (locked + 1 == disks)
1736 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
1737 atomic_inc(&sh->raid_conf->pending_full_writes);
Dan Williamse33129d2007-01-02 13:52:30 -07001738 } else {
1739 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
1740 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
1741
1742 set_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
1743 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
1744 set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
1745
1746 sh->ops.count += 3;
1747
1748 for (i = disks; i--; ) {
1749 struct r5dev *dev = &sh->dev[i];
1750 if (i == pd_idx)
1751 continue;
1752
1753 /* For a read-modify write there may be blocks that are
1754 * locked for reading while others are ready to be
1755 * written so we distinguish these blocks by the
1756 * R5_Wantprexor bit
1757 */
1758 if (dev->towrite &&
1759 (test_bit(R5_UPTODATE, &dev->flags) ||
1760 test_bit(R5_Wantcompute, &dev->flags))) {
1761 set_bit(R5_Wantprexor, &dev->flags);
1762 set_bit(R5_LOCKED, &dev->flags);
1763 clear_bit(R5_UPTODATE, &dev->flags);
1764 locked++;
1765 }
1766 }
1767 }
1768
1769 /* keep the parity disk locked while asynchronous operations
1770 * are in flight
1771 */
1772 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1773 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1774 locked++;
1775
1776 pr_debug("%s: stripe %llu locked: %d pending: %lx\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -07001777 __func__, (unsigned long long)sh->sector,
Dan Williamse33129d2007-01-02 13:52:30 -07001778 locked, sh->ops.pending);
1779
1780 return locked;
1781}
NeilBrown16a53ec2006-06-26 00:27:38 -07001782
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783/*
1784 * Each stripe/dev can have one or more bion attached.
NeilBrown16a53ec2006-06-26 00:27:38 -07001785 * toread/towrite point to the first in a chain.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 * The bi_next chain must be in order.
1787 */
1788static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1789{
1790 struct bio **bip;
1791 raid5_conf_t *conf = sh->raid_conf;
NeilBrown72626682005-09-09 16:23:54 -07001792 int firstwrite=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793
Dan Williams45b42332007-07-09 11:56:43 -07001794 pr_debug("adding bh b#%llu to stripe s#%llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 (unsigned long long)bi->bi_sector,
1796 (unsigned long long)sh->sector);
1797
1798
1799 spin_lock(&sh->lock);
1800 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07001801 if (forwrite) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 bip = &sh->dev[dd_idx].towrite;
NeilBrown72626682005-09-09 16:23:54 -07001803 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1804 firstwrite = 1;
1805 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806 bip = &sh->dev[dd_idx].toread;
1807 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1808 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1809 goto overlap;
1810 bip = & (*bip)->bi_next;
1811 }
1812 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1813 goto overlap;
1814
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001815 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816 if (*bip)
1817 bi->bi_next = *bip;
1818 *bip = bi;
1819 bi->bi_phys_segments ++;
1820 spin_unlock_irq(&conf->device_lock);
1821 spin_unlock(&sh->lock);
1822
Dan Williams45b42332007-07-09 11:56:43 -07001823 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 (unsigned long long)bi->bi_sector,
1825 (unsigned long long)sh->sector, dd_idx);
1826
NeilBrown72626682005-09-09 16:23:54 -07001827 if (conf->mddev->bitmap && firstwrite) {
NeilBrown72626682005-09-09 16:23:54 -07001828 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1829 STRIPE_SECTORS, 0);
NeilBrownae3c20c2006-07-10 04:44:17 -07001830 sh->bm_seq = conf->seq_flush+1;
NeilBrown72626682005-09-09 16:23:54 -07001831 set_bit(STRIPE_BIT_DELAY, &sh->state);
1832 }
1833
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 if (forwrite) {
1835 /* check if page is covered */
1836 sector_t sector = sh->dev[dd_idx].sector;
1837 for (bi=sh->dev[dd_idx].towrite;
1838 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1839 bi && bi->bi_sector <= sector;
1840 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1841 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1842 sector = bi->bi_sector + (bi->bi_size>>9);
1843 }
1844 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1845 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1846 }
1847 return 1;
1848
1849 overlap:
1850 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1851 spin_unlock_irq(&conf->device_lock);
1852 spin_unlock(&sh->lock);
1853 return 0;
1854}
1855
NeilBrown29269552006-03-27 01:18:10 -08001856static void end_reshape(raid5_conf_t *conf);
1857
NeilBrown16a53ec2006-06-26 00:27:38 -07001858static int page_is_zero(struct page *p)
1859{
1860 char *a = page_address(p);
1861 return ((*(u32*)a) == 0 &&
1862 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1863}
1864
NeilBrownccfcc3c2006-03-27 01:18:09 -08001865static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1866{
1867 int sectors_per_chunk = conf->chunk_size >> 9;
NeilBrownccfcc3c2006-03-27 01:18:09 -08001868 int pd_idx, dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07001869 int chunk_offset = sector_div(stripe, sectors_per_chunk);
1870
NeilBrownb875e532006-12-10 02:20:49 -08001871 raid5_compute_sector(stripe * (disks - conf->max_degraded)
1872 *sectors_per_chunk + chunk_offset,
1873 disks, disks - conf->max_degraded,
1874 &dd_idx, &pd_idx, conf);
NeilBrownccfcc3c2006-03-27 01:18:09 -08001875 return pd_idx;
1876}
1877
Dan Williamsa4456852007-07-09 11:56:43 -07001878static void
1879handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
1880 struct stripe_head_state *s, int disks,
1881 struct bio **return_bi)
1882{
1883 int i;
1884 for (i = disks; i--; ) {
1885 struct bio *bi;
1886 int bitmap_end = 0;
1887
1888 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1889 mdk_rdev_t *rdev;
1890 rcu_read_lock();
1891 rdev = rcu_dereference(conf->disks[i].rdev);
1892 if (rdev && test_bit(In_sync, &rdev->flags))
1893 /* multiple read failures in one stripe */
1894 md_error(conf->mddev, rdev);
1895 rcu_read_unlock();
1896 }
1897 spin_lock_irq(&conf->device_lock);
1898 /* fail all writes first */
1899 bi = sh->dev[i].towrite;
1900 sh->dev[i].towrite = NULL;
1901 if (bi) {
1902 s->to_write--;
1903 bitmap_end = 1;
1904 }
1905
1906 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1907 wake_up(&conf->wait_for_overlap);
1908
1909 while (bi && bi->bi_sector <
1910 sh->dev[i].sector + STRIPE_SECTORS) {
1911 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
1912 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1913 if (--bi->bi_phys_segments == 0) {
1914 md_write_end(conf->mddev);
1915 bi->bi_next = *return_bi;
1916 *return_bi = bi;
1917 }
1918 bi = nextbi;
1919 }
1920 /* and fail all 'written' */
1921 bi = sh->dev[i].written;
1922 sh->dev[i].written = NULL;
1923 if (bi) bitmap_end = 1;
1924 while (bi && bi->bi_sector <
1925 sh->dev[i].sector + STRIPE_SECTORS) {
1926 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
1927 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1928 if (--bi->bi_phys_segments == 0) {
1929 md_write_end(conf->mddev);
1930 bi->bi_next = *return_bi;
1931 *return_bi = bi;
1932 }
1933 bi = bi2;
1934 }
1935
Dan Williamsb5e98d62007-01-02 13:52:31 -07001936 /* fail any reads if this device is non-operational and
1937 * the data has not reached the cache yet.
1938 */
1939 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
1940 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
1941 test_bit(R5_ReadError, &sh->dev[i].flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07001942 bi = sh->dev[i].toread;
1943 sh->dev[i].toread = NULL;
1944 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1945 wake_up(&conf->wait_for_overlap);
1946 if (bi) s->to_read--;
1947 while (bi && bi->bi_sector <
1948 sh->dev[i].sector + STRIPE_SECTORS) {
1949 struct bio *nextbi =
1950 r5_next_bio(bi, sh->dev[i].sector);
1951 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1952 if (--bi->bi_phys_segments == 0) {
1953 bi->bi_next = *return_bi;
1954 *return_bi = bi;
1955 }
1956 bi = nextbi;
1957 }
1958 }
1959 spin_unlock_irq(&conf->device_lock);
1960 if (bitmap_end)
1961 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
1962 STRIPE_SECTORS, 0, 0);
1963 }
1964
Dan Williams8b3e6cd2008-04-28 02:15:53 -07001965 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
1966 if (atomic_dec_and_test(&conf->pending_full_writes))
1967 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07001968}
1969
Dan Williamsf38e1212007-01-02 13:52:30 -07001970/* __handle_issuing_new_read_requests5 - returns 0 if there are no more disks
1971 * to process
1972 */
1973static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
1974 struct stripe_head_state *s, int disk_idx, int disks)
1975{
1976 struct r5dev *dev = &sh->dev[disk_idx];
1977 struct r5dev *failed_dev = &sh->dev[s->failed_num];
1978
1979 /* don't schedule compute operations or reads on the parity block while
1980 * a check is in flight
1981 */
1982 if ((disk_idx == sh->pd_idx) &&
1983 test_bit(STRIPE_OP_CHECK, &sh->ops.pending))
1984 return ~0;
1985
1986 /* is the data in this block needed, and can we get it? */
1987 if (!test_bit(R5_LOCKED, &dev->flags) &&
1988 !test_bit(R5_UPTODATE, &dev->flags) && (dev->toread ||
1989 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
1990 s->syncing || s->expanding || (s->failed &&
1991 (failed_dev->toread || (failed_dev->towrite &&
1992 !test_bit(R5_OVERWRITE, &failed_dev->flags)
1993 ))))) {
1994 /* 1/ We would like to get this block, possibly by computing it,
1995 * but we might not be able to.
1996 *
1997 * 2/ Since parity check operations potentially make the parity
1998 * block !uptodate it will need to be refreshed before any
1999 * compute operations on data disks are scheduled.
2000 *
2001 * 3/ We hold off parity block re-reads until check operations
2002 * have quiesced.
2003 */
2004 if ((s->uptodate == disks - 1) &&
Dan Williamsc3378692008-06-05 22:45:54 -07002005 (s->failed && disk_idx == s->failed_num) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002006 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
2007 set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
2008 set_bit(R5_Wantcompute, &dev->flags);
2009 sh->ops.target = disk_idx;
2010 s->req_compute = 1;
2011 sh->ops.count++;
2012 /* Careful: from this point on 'uptodate' is in the eye
2013 * of raid5_run_ops which services 'compute' operations
2014 * before writes. R5_Wantcompute flags a block that will
2015 * be R5_UPTODATE by the time it is needed for a
2016 * subsequent operation.
2017 */
2018 s->uptodate++;
2019 return 0; /* uptodate + compute == disks */
2020 } else if ((s->uptodate < disks - 1) &&
2021 test_bit(R5_Insync, &dev->flags)) {
2022 /* Note: we hold off compute operations while checks are
2023 * in flight, but we still prefer 'compute' over 'read'
2024 * hence we only read if (uptodate < * disks-1)
2025 */
2026 set_bit(R5_LOCKED, &dev->flags);
2027 set_bit(R5_Wantread, &dev->flags);
2028 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2029 sh->ops.count++;
2030 s->locked++;
2031 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2032 s->syncing);
2033 }
2034 }
2035
2036 return ~0;
2037}
2038
Dan Williamsa4456852007-07-09 11:56:43 -07002039static void handle_issuing_new_read_requests5(struct stripe_head *sh,
2040 struct stripe_head_state *s, int disks)
2041{
2042 int i;
Dan Williamsf38e1212007-01-02 13:52:30 -07002043
2044 /* Clear completed compute operations. Parity recovery
2045 * (STRIPE_OP_MOD_REPAIR_PD) implies a write-back which is handled
2046 * later on in this routine
2047 */
2048 if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
2049 !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2050 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
2051 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
2052 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
2053 }
2054
2055 /* look for blocks to read/compute, skip this if a compute
2056 * is already in flight, or if the stripe contents are in the
2057 * midst of changing due to a write
2058 */
2059 if (!test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending) &&
2060 !test_bit(STRIPE_OP_PREXOR, &sh->ops.pending) &&
2061 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
2062 for (i = disks; i--; )
2063 if (__handle_issuing_new_read_requests5(
2064 sh, s, i, disks) == 0)
2065 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002066 }
2067 set_bit(STRIPE_HANDLE, &sh->state);
2068}
2069
2070static void handle_issuing_new_read_requests6(struct stripe_head *sh,
2071 struct stripe_head_state *s, struct r6_state *r6s,
2072 int disks)
2073{
2074 int i;
2075 for (i = disks; i--; ) {
2076 struct r5dev *dev = &sh->dev[i];
2077 if (!test_bit(R5_LOCKED, &dev->flags) &&
2078 !test_bit(R5_UPTODATE, &dev->flags) &&
2079 (dev->toread || (dev->towrite &&
2080 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2081 s->syncing || s->expanding ||
2082 (s->failed >= 1 &&
2083 (sh->dev[r6s->failed_num[0]].toread ||
2084 s->to_write)) ||
2085 (s->failed >= 2 &&
2086 (sh->dev[r6s->failed_num[1]].toread ||
2087 s->to_write)))) {
2088 /* we would like to get this block, possibly
2089 * by computing it, but we might not be able to
2090 */
Dan Williamsc3378692008-06-05 22:45:54 -07002091 if ((s->uptodate == disks - 1) &&
2092 (s->failed && (i == r6s->failed_num[0] ||
2093 i == r6s->failed_num[1]))) {
Dan Williams45b42332007-07-09 11:56:43 -07002094 pr_debug("Computing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002095 (unsigned long long)sh->sector, i);
2096 compute_block_1(sh, i, 0);
2097 s->uptodate++;
2098 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2099 /* Computing 2-failure is *very* expensive; only
2100 * do it if failed >= 2
2101 */
2102 int other;
2103 for (other = disks; other--; ) {
2104 if (other == i)
2105 continue;
2106 if (!test_bit(R5_UPTODATE,
2107 &sh->dev[other].flags))
2108 break;
2109 }
2110 BUG_ON(other < 0);
Dan Williams45b42332007-07-09 11:56:43 -07002111 pr_debug("Computing stripe %llu blocks %d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002112 (unsigned long long)sh->sector,
2113 i, other);
2114 compute_block_2(sh, i, other);
2115 s->uptodate += 2;
2116 } else if (test_bit(R5_Insync, &dev->flags)) {
2117 set_bit(R5_LOCKED, &dev->flags);
2118 set_bit(R5_Wantread, &dev->flags);
2119 s->locked++;
Dan Williams45b42332007-07-09 11:56:43 -07002120 pr_debug("Reading block %d (sync=%d)\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002121 i, s->syncing);
2122 }
2123 }
2124 }
2125 set_bit(STRIPE_HANDLE, &sh->state);
2126}
2127
2128
2129/* handle_completed_write_requests
2130 * any written block on an uptodate or failed drive can be returned.
2131 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2132 * never LOCKED, so we don't need to test 'failed' directly.
2133 */
2134static void handle_completed_write_requests(raid5_conf_t *conf,
2135 struct stripe_head *sh, int disks, struct bio **return_bi)
2136{
2137 int i;
2138 struct r5dev *dev;
2139
2140 for (i = disks; i--; )
2141 if (sh->dev[i].written) {
2142 dev = &sh->dev[i];
2143 if (!test_bit(R5_LOCKED, &dev->flags) &&
2144 test_bit(R5_UPTODATE, &dev->flags)) {
2145 /* We can return any write requests */
2146 struct bio *wbi, *wbi2;
2147 int bitmap_end = 0;
Dan Williams45b42332007-07-09 11:56:43 -07002148 pr_debug("Return write for disc %d\n", i);
Dan Williamsa4456852007-07-09 11:56:43 -07002149 spin_lock_irq(&conf->device_lock);
2150 wbi = dev->written;
2151 dev->written = NULL;
2152 while (wbi && wbi->bi_sector <
2153 dev->sector + STRIPE_SECTORS) {
2154 wbi2 = r5_next_bio(wbi, dev->sector);
2155 if (--wbi->bi_phys_segments == 0) {
2156 md_write_end(conf->mddev);
2157 wbi->bi_next = *return_bi;
2158 *return_bi = wbi;
2159 }
2160 wbi = wbi2;
2161 }
2162 if (dev->towrite == NULL)
2163 bitmap_end = 1;
2164 spin_unlock_irq(&conf->device_lock);
2165 if (bitmap_end)
2166 bitmap_endwrite(conf->mddev->bitmap,
2167 sh->sector,
2168 STRIPE_SECTORS,
2169 !test_bit(STRIPE_DEGRADED, &sh->state),
2170 0);
2171 }
2172 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002173
2174 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2175 if (atomic_dec_and_test(&conf->pending_full_writes))
2176 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002177}
2178
2179static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
2180 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2181{
2182 int rmw = 0, rcw = 0, i;
2183 for (i = disks; i--; ) {
2184 /* would I have to read this buffer for read_modify_write */
2185 struct r5dev *dev = &sh->dev[i];
2186 if ((dev->towrite || i == sh->pd_idx) &&
2187 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002188 !(test_bit(R5_UPTODATE, &dev->flags) ||
2189 test_bit(R5_Wantcompute, &dev->flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002190 if (test_bit(R5_Insync, &dev->flags))
2191 rmw++;
2192 else
2193 rmw += 2*disks; /* cannot read it */
2194 }
2195 /* Would I have to read this buffer for reconstruct_write */
2196 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2197 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002198 !(test_bit(R5_UPTODATE, &dev->flags) ||
2199 test_bit(R5_Wantcompute, &dev->flags))) {
2200 if (test_bit(R5_Insync, &dev->flags)) rcw++;
Dan Williamsa4456852007-07-09 11:56:43 -07002201 else
2202 rcw += 2*disks;
2203 }
2204 }
Dan Williams45b42332007-07-09 11:56:43 -07002205 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002206 (unsigned long long)sh->sector, rmw, rcw);
2207 set_bit(STRIPE_HANDLE, &sh->state);
2208 if (rmw < rcw && rmw > 0)
2209 /* prefer read-modify-write, but need to get some data */
2210 for (i = disks; i--; ) {
2211 struct r5dev *dev = &sh->dev[i];
2212 if ((dev->towrite || i == sh->pd_idx) &&
2213 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002214 !(test_bit(R5_UPTODATE, &dev->flags) ||
2215 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002216 test_bit(R5_Insync, &dev->flags)) {
2217 if (
2218 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002219 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002220 "%d for r-m-w\n", i);
2221 set_bit(R5_LOCKED, &dev->flags);
2222 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002223 if (!test_and_set_bit(
2224 STRIPE_OP_IO, &sh->ops.pending))
2225 sh->ops.count++;
Dan Williamsa4456852007-07-09 11:56:43 -07002226 s->locked++;
2227 } else {
2228 set_bit(STRIPE_DELAYED, &sh->state);
2229 set_bit(STRIPE_HANDLE, &sh->state);
2230 }
2231 }
2232 }
2233 if (rcw <= rmw && rcw > 0)
2234 /* want reconstruct write, but need to get some data */
2235 for (i = disks; i--; ) {
2236 struct r5dev *dev = &sh->dev[i];
2237 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2238 i != sh->pd_idx &&
2239 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002240 !(test_bit(R5_UPTODATE, &dev->flags) ||
2241 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002242 test_bit(R5_Insync, &dev->flags)) {
2243 if (
2244 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002245 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002246 "%d for Reconstruct\n", i);
2247 set_bit(R5_LOCKED, &dev->flags);
2248 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002249 if (!test_and_set_bit(
2250 STRIPE_OP_IO, &sh->ops.pending))
2251 sh->ops.count++;
Dan Williamsa4456852007-07-09 11:56:43 -07002252 s->locked++;
2253 } else {
2254 set_bit(STRIPE_DELAYED, &sh->state);
2255 set_bit(STRIPE_HANDLE, &sh->state);
2256 }
2257 }
2258 }
2259 /* now if nothing is locked, and if we have enough data,
2260 * we can start a write request
2261 */
Dan Williamsf38e1212007-01-02 13:52:30 -07002262 /* since handle_stripe can be called at any time we need to handle the
2263 * case where a compute block operation has been submitted and then a
2264 * subsequent call wants to start a write request. raid5_run_ops only
2265 * handles the case where compute block and postxor are requested
2266 * simultaneously. If this is not the case then new writes need to be
2267 * held off until the compute completes.
2268 */
2269 if ((s->req_compute ||
2270 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) &&
2271 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2272 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
Dan Williamse33129d2007-01-02 13:52:30 -07002273 s->locked += handle_write_operations5(sh, rcw == 0, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002274}
2275
2276static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
2277 struct stripe_head *sh, struct stripe_head_state *s,
2278 struct r6_state *r6s, int disks)
2279{
2280 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
2281 int qd_idx = r6s->qd_idx;
2282 for (i = disks; i--; ) {
2283 struct r5dev *dev = &sh->dev[i];
2284 /* Would I have to read this buffer for reconstruct_write */
2285 if (!test_bit(R5_OVERWRITE, &dev->flags)
2286 && i != pd_idx && i != qd_idx
2287 && (!test_bit(R5_LOCKED, &dev->flags)
2288 ) &&
2289 !test_bit(R5_UPTODATE, &dev->flags)) {
2290 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2291 else {
Dan Williams45b42332007-07-09 11:56:43 -07002292 pr_debug("raid6: must_compute: "
Dan Williamsa4456852007-07-09 11:56:43 -07002293 "disk %d flags=%#lx\n", i, dev->flags);
2294 must_compute++;
2295 }
2296 }
2297 }
Dan Williams45b42332007-07-09 11:56:43 -07002298 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002299 (unsigned long long)sh->sector, rcw, must_compute);
2300 set_bit(STRIPE_HANDLE, &sh->state);
2301
2302 if (rcw > 0)
2303 /* want reconstruct write, but need to get some data */
2304 for (i = disks; i--; ) {
2305 struct r5dev *dev = &sh->dev[i];
2306 if (!test_bit(R5_OVERWRITE, &dev->flags)
2307 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2308 && !test_bit(R5_LOCKED, &dev->flags) &&
2309 !test_bit(R5_UPTODATE, &dev->flags) &&
2310 test_bit(R5_Insync, &dev->flags)) {
2311 if (
2312 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002313 pr_debug("Read_old stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002314 "block %d for Reconstruct\n",
2315 (unsigned long long)sh->sector, i);
2316 set_bit(R5_LOCKED, &dev->flags);
2317 set_bit(R5_Wantread, &dev->flags);
2318 s->locked++;
2319 } else {
Dan Williams45b42332007-07-09 11:56:43 -07002320 pr_debug("Request delayed stripe %llu "
Dan Williamsa4456852007-07-09 11:56:43 -07002321 "block %d for Reconstruct\n",
2322 (unsigned long long)sh->sector, i);
2323 set_bit(STRIPE_DELAYED, &sh->state);
2324 set_bit(STRIPE_HANDLE, &sh->state);
2325 }
2326 }
2327 }
2328 /* now if nothing is locked, and if we have enough data, we can start a
2329 * write request
2330 */
2331 if (s->locked == 0 && rcw == 0 &&
2332 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2333 if (must_compute > 0) {
2334 /* We have failed blocks and need to compute them */
2335 switch (s->failed) {
2336 case 0:
2337 BUG();
2338 case 1:
2339 compute_block_1(sh, r6s->failed_num[0], 0);
2340 break;
2341 case 2:
2342 compute_block_2(sh, r6s->failed_num[0],
2343 r6s->failed_num[1]);
2344 break;
2345 default: /* This request should have been failed? */
2346 BUG();
2347 }
2348 }
2349
Dan Williams45b42332007-07-09 11:56:43 -07002350 pr_debug("Computing parity for stripe %llu\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002351 (unsigned long long)sh->sector);
2352 compute_parity6(sh, RECONSTRUCT_WRITE);
2353 /* now every locked buffer is ready to be written */
2354 for (i = disks; i--; )
2355 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
Dan Williams45b42332007-07-09 11:56:43 -07002356 pr_debug("Writing stripe %llu block %d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002357 (unsigned long long)sh->sector, i);
2358 s->locked++;
2359 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2360 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002361 if (s->locked == disks)
2362 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2363 atomic_inc(&conf->pending_full_writes);
Dan Williamsa4456852007-07-09 11:56:43 -07002364 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2365 set_bit(STRIPE_INSYNC, &sh->state);
2366
2367 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2368 atomic_dec(&conf->preread_active_stripes);
2369 if (atomic_read(&conf->preread_active_stripes) <
2370 IO_THRESHOLD)
2371 md_wakeup_thread(conf->mddev->thread);
2372 }
2373 }
2374}
2375
2376static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2377 struct stripe_head_state *s, int disks)
2378{
Dan Williamsbd2ab672008-04-10 21:29:27 -07002379 int canceled_check = 0;
Dan Williamse89f8962007-01-02 13:52:31 -07002380
Dan Williamsbd2ab672008-04-10 21:29:27 -07002381 set_bit(STRIPE_HANDLE, &sh->state);
2382
2383 /* complete a check operation */
2384 if (test_and_clear_bit(STRIPE_OP_CHECK, &sh->ops.complete)) {
Dan Williamsc88944192008-05-12 14:02:12 -07002385 clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
2386 clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002387 if (s->failed == 0) {
Dan Williamse89f8962007-01-02 13:52:31 -07002388 if (sh->ops.zero_sum_result == 0)
2389 /* parity is correct (on disc,
2390 * not in buffer any more)
2391 */
Dan Williamsa4456852007-07-09 11:56:43 -07002392 set_bit(STRIPE_INSYNC, &sh->state);
2393 else {
Dan Williamse89f8962007-01-02 13:52:31 -07002394 conf->mddev->resync_mismatches +=
2395 STRIPE_SECTORS;
2396 if (test_bit(
2397 MD_RECOVERY_CHECK, &conf->mddev->recovery))
2398 /* don't try to repair!! */
2399 set_bit(STRIPE_INSYNC, &sh->state);
2400 else {
2401 set_bit(STRIPE_OP_COMPUTE_BLK,
2402 &sh->ops.pending);
2403 set_bit(STRIPE_OP_MOD_REPAIR_PD,
2404 &sh->ops.pending);
2405 set_bit(R5_Wantcompute,
2406 &sh->dev[sh->pd_idx].flags);
2407 sh->ops.target = sh->pd_idx;
2408 sh->ops.count++;
2409 s->uptodate++;
2410 }
Dan Williamsa4456852007-07-09 11:56:43 -07002411 }
Dan Williamsbd2ab672008-04-10 21:29:27 -07002412 } else
2413 canceled_check = 1; /* STRIPE_INSYNC is not set */
Dan Williamsa4456852007-07-09 11:56:43 -07002414 }
Dan Williamse89f8962007-01-02 13:52:31 -07002415
Dan Williamsbd2ab672008-04-10 21:29:27 -07002416 /* start a new check operation if there are no failures, the stripe is
2417 * not insync, and a repair is not in flight
Dan Williamse89f8962007-01-02 13:52:31 -07002418 */
Dan Williamsbd2ab672008-04-10 21:29:27 -07002419 if (s->failed == 0 &&
2420 !test_bit(STRIPE_INSYNC, &sh->state) &&
2421 !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2422 if (!test_and_set_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
2423 BUG_ON(s->uptodate != disks);
2424 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2425 sh->ops.count++;
2426 s->uptodate--;
2427 }
2428 }
2429
Dan Williamsc88944192008-05-12 14:02:12 -07002430 /* check if we can clear a parity disk reconstruct */
2431 if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
2432 test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
2433
2434 clear_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending);
2435 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
2436 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
2437 clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
2438 }
2439
2440
Dan Williamsbd2ab672008-04-10 21:29:27 -07002441 /* Wait for check parity and compute block operations to complete
2442 * before write-back. If a failure occurred while the check operation
2443 * was in flight we need to cycle this stripe through handle_stripe
2444 * since the parity block may not be uptodate
2445 */
2446 if (!canceled_check && !test_bit(STRIPE_INSYNC, &sh->state) &&
2447 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending) &&
2448 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002449 struct r5dev *dev;
2450 /* either failed parity check, or recovery is happening */
2451 if (s->failed == 0)
2452 s->failed_num = sh->pd_idx;
2453 dev = &sh->dev[s->failed_num];
2454 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2455 BUG_ON(s->uptodate != disks);
2456
2457 set_bit(R5_LOCKED, &dev->flags);
2458 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002459 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2460 sh->ops.count++;
2461
Dan Williamsa4456852007-07-09 11:56:43 -07002462 clear_bit(STRIPE_DEGRADED, &sh->state);
2463 s->locked++;
2464 set_bit(STRIPE_INSYNC, &sh->state);
2465 }
2466}
2467
2468
2469static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2470 struct stripe_head_state *s,
2471 struct r6_state *r6s, struct page *tmp_page,
2472 int disks)
2473{
2474 int update_p = 0, update_q = 0;
2475 struct r5dev *dev;
2476 int pd_idx = sh->pd_idx;
2477 int qd_idx = r6s->qd_idx;
2478
2479 set_bit(STRIPE_HANDLE, &sh->state);
2480
2481 BUG_ON(s->failed > 2);
2482 BUG_ON(s->uptodate < disks);
2483 /* Want to check and possibly repair P and Q.
2484 * However there could be one 'failed' device, in which
2485 * case we can only check one of them, possibly using the
2486 * other to generate missing data
2487 */
2488
2489 /* If !tmp_page, we cannot do the calculations,
2490 * but as we have set STRIPE_HANDLE, we will soon be called
2491 * by stripe_handle with a tmp_page - just wait until then.
2492 */
2493 if (tmp_page) {
2494 if (s->failed == r6s->q_failed) {
2495 /* The only possible failed device holds 'Q', so it
2496 * makes sense to check P (If anything else were failed,
2497 * we would have used P to recreate it).
2498 */
2499 compute_block_1(sh, pd_idx, 1);
2500 if (!page_is_zero(sh->dev[pd_idx].page)) {
2501 compute_block_1(sh, pd_idx, 0);
2502 update_p = 1;
2503 }
2504 }
2505 if (!r6s->q_failed && s->failed < 2) {
2506 /* q is not failed, and we didn't use it to generate
2507 * anything, so it makes sense to check it
2508 */
2509 memcpy(page_address(tmp_page),
2510 page_address(sh->dev[qd_idx].page),
2511 STRIPE_SIZE);
2512 compute_parity6(sh, UPDATE_PARITY);
2513 if (memcmp(page_address(tmp_page),
2514 page_address(sh->dev[qd_idx].page),
2515 STRIPE_SIZE) != 0) {
2516 clear_bit(STRIPE_INSYNC, &sh->state);
2517 update_q = 1;
2518 }
2519 }
2520 if (update_p || update_q) {
2521 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2522 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2523 /* don't try to repair!! */
2524 update_p = update_q = 0;
2525 }
2526
2527 /* now write out any block on a failed drive,
2528 * or P or Q if they need it
2529 */
2530
2531 if (s->failed == 2) {
2532 dev = &sh->dev[r6s->failed_num[1]];
2533 s->locked++;
2534 set_bit(R5_LOCKED, &dev->flags);
2535 set_bit(R5_Wantwrite, &dev->flags);
2536 }
2537 if (s->failed >= 1) {
2538 dev = &sh->dev[r6s->failed_num[0]];
2539 s->locked++;
2540 set_bit(R5_LOCKED, &dev->flags);
2541 set_bit(R5_Wantwrite, &dev->flags);
2542 }
2543
2544 if (update_p) {
2545 dev = &sh->dev[pd_idx];
2546 s->locked++;
2547 set_bit(R5_LOCKED, &dev->flags);
2548 set_bit(R5_Wantwrite, &dev->flags);
2549 }
2550 if (update_q) {
2551 dev = &sh->dev[qd_idx];
2552 s->locked++;
2553 set_bit(R5_LOCKED, &dev->flags);
2554 set_bit(R5_Wantwrite, &dev->flags);
2555 }
2556 clear_bit(STRIPE_DEGRADED, &sh->state);
2557
2558 set_bit(STRIPE_INSYNC, &sh->state);
2559 }
2560}
2561
2562static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2563 struct r6_state *r6s)
2564{
2565 int i;
2566
2567 /* We have read all the blocks in this stripe and now we need to
2568 * copy some of them into a target stripe for expand.
2569 */
Dan Williamsf0a50d32007-01-02 13:52:31 -07002570 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsa4456852007-07-09 11:56:43 -07002571 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2572 for (i = 0; i < sh->disks; i++)
NeilBrowna2e08552007-09-11 15:23:36 -07002573 if (i != sh->pd_idx && (!r6s || i != r6s->qd_idx)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002574 int dd_idx, pd_idx, j;
2575 struct stripe_head *sh2;
2576
2577 sector_t bn = compute_blocknr(sh, i);
2578 sector_t s = raid5_compute_sector(bn, conf->raid_disks,
2579 conf->raid_disks -
2580 conf->max_degraded, &dd_idx,
2581 &pd_idx, conf);
2582 sh2 = get_active_stripe(conf, s, conf->raid_disks,
2583 pd_idx, 1);
2584 if (sh2 == NULL)
2585 /* so far only the early blocks of this stripe
2586 * have been requested. When later blocks
2587 * get requested, we will try again
2588 */
2589 continue;
2590 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2591 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2592 /* must have already done this block */
2593 release_stripe(sh2);
2594 continue;
2595 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002596
2597 /* place all the copies on one channel */
2598 tx = async_memcpy(sh2->dev[dd_idx].page,
2599 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2600 ASYNC_TX_DEP_ACK, tx, NULL, NULL);
2601
Dan Williamsa4456852007-07-09 11:56:43 -07002602 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2603 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2604 for (j = 0; j < conf->raid_disks; j++)
2605 if (j != sh2->pd_idx &&
NeilBrowna2e08552007-09-11 15:23:36 -07002606 (!r6s || j != raid6_next_disk(sh2->pd_idx,
2607 sh2->disks)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002608 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2609 break;
2610 if (j == conf->raid_disks) {
2611 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2612 set_bit(STRIPE_HANDLE, &sh2->state);
2613 }
2614 release_stripe(sh2);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002615
Dan Williamsa4456852007-07-09 11:56:43 -07002616 }
NeilBrowna2e08552007-09-11 15:23:36 -07002617 /* done submitting copies, wait for them to complete */
2618 if (tx) {
2619 async_tx_ack(tx);
2620 dma_wait_for_async_tx(tx);
2621 }
Dan Williamsa4456852007-07-09 11:56:43 -07002622}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002623
Dan Williams6bfe0b42008-04-30 00:52:32 -07002624
Linus Torvalds1da177e2005-04-16 15:20:36 -07002625/*
2626 * handle_stripe - do things to a stripe.
2627 *
2628 * We lock the stripe and then examine the state of various bits
2629 * to see what needs to be done.
2630 * Possible results:
2631 * return some read request which now have data
2632 * return some write requests which are safely on disc
2633 * schedule a read on some buffers
2634 * schedule a write of some buffers
2635 * return confirmation of parity correctness
2636 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002637 * buffers are taken off read_list or write_list, and bh_cache buffers
2638 * get BH_Lock set before the stripe lock is released.
2639 *
2640 */
Dan Williamsa4456852007-07-09 11:56:43 -07002641
NeilBrown16a53ec2006-06-26 00:27:38 -07002642static void handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002643{
2644 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa4456852007-07-09 11:56:43 -07002645 int disks = sh->disks, i;
2646 struct bio *return_bi = NULL;
2647 struct stripe_head_state s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002648 struct r5dev *dev;
Dan Williamsd84e0f12007-01-02 13:52:30 -07002649 unsigned long pending = 0;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002650 mdk_rdev_t *blocked_rdev = NULL;
Dan Williamse0a115e2008-06-05 22:45:52 -07002651 int prexor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002652
Dan Williamsa4456852007-07-09 11:56:43 -07002653 memset(&s, 0, sizeof(s));
Dan Williamsd84e0f12007-01-02 13:52:30 -07002654 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d "
2655 "ops=%lx:%lx:%lx\n", (unsigned long long)sh->sector, sh->state,
2656 atomic_read(&sh->count), sh->pd_idx,
2657 sh->ops.pending, sh->ops.ack, sh->ops.complete);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002658
2659 spin_lock(&sh->lock);
2660 clear_bit(STRIPE_HANDLE, &sh->state);
2661 clear_bit(STRIPE_DELAYED, &sh->state);
2662
Dan Williamsa4456852007-07-09 11:56:43 -07002663 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2664 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2665 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002666 /* Now to look around and see what can be done */
2667
Neil Browndef6ae22007-11-05 14:51:02 -08002668 /* clean-up completed biofill operations */
2669 if (test_bit(STRIPE_OP_BIOFILL, &sh->ops.complete)) {
2670 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.pending);
2671 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.ack);
2672 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
2673 }
2674
NeilBrown9910f162006-01-06 00:20:24 -08002675 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002676 for (i=disks; i--; ) {
2677 mdk_rdev_t *rdev;
Dan Williamsa4456852007-07-09 11:56:43 -07002678 struct r5dev *dev = &sh->dev[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002679 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002680
Dan Williamsb5e98d62007-01-02 13:52:31 -07002681 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2682 "written %p\n", i, dev->flags, dev->toread, dev->read,
2683 dev->towrite, dev->written);
2684
2685 /* maybe we can request a biofill operation
2686 *
2687 * new wantfill requests are only permitted while
2688 * STRIPE_OP_BIOFILL is clear
2689 */
2690 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
2691 !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
2692 set_bit(R5_Wantfill, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002693
2694 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002695 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2696 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williamsf38e1212007-01-02 13:52:30 -07002697 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002698
Dan Williamsb5e98d62007-01-02 13:52:31 -07002699 if (test_bit(R5_Wantfill, &dev->flags))
2700 s.to_fill++;
2701 else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07002702 s.to_read++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002703 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002704 s.to_write++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002705 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002706 s.non_overwrite++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002707 }
Dan Williamsa4456852007-07-09 11:56:43 -07002708 if (dev->written)
2709 s.written++;
NeilBrown9910f162006-01-06 00:20:24 -08002710 rdev = rcu_dereference(conf->disks[i].rdev);
Dan Williams6bfe0b42008-04-30 00:52:32 -07002711 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
2712 blocked_rdev = rdev;
2713 atomic_inc(&rdev->nr_pending);
2714 break;
2715 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002716 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08002717 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08002718 clear_bit(R5_ReadError, &dev->flags);
2719 clear_bit(R5_ReWrite, &dev->flags);
2720 }
NeilBrownb2d444d2005-11-08 21:39:31 -08002721 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002722 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002723 s.failed++;
2724 s.failed_num = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002725 } else
2726 set_bit(R5_Insync, &dev->flags);
2727 }
NeilBrown9910f162006-01-06 00:20:24 -08002728 rcu_read_unlock();
Dan Williamsb5e98d62007-01-02 13:52:31 -07002729
Dan Williams6bfe0b42008-04-30 00:52:32 -07002730 if (unlikely(blocked_rdev)) {
2731 set_bit(STRIPE_HANDLE, &sh->state);
2732 goto unlock;
2733 }
2734
Dan Williamsb5e98d62007-01-02 13:52:31 -07002735 if (s.to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
2736 sh->ops.count++;
2737
Dan Williams45b42332007-07-09 11:56:43 -07002738 pr_debug("locked=%d uptodate=%d to_read=%d"
Linus Torvalds1da177e2005-04-16 15:20:36 -07002739 " to_write=%d failed=%d failed_num=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002740 s.locked, s.uptodate, s.to_read, s.to_write,
2741 s.failed, s.failed_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002742 /* check if the array has lost two devices and, if so, some requests might
2743 * need to be failed
2744 */
Dan Williamsa4456852007-07-09 11:56:43 -07002745 if (s.failed > 1 && s.to_read+s.to_write+s.written)
2746 handle_requests_to_failed_array(conf, sh, &s, disks,
2747 &return_bi);
2748 if (s.failed > 1 && s.syncing) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002749 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2750 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002751 s.syncing = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002752 }
2753
2754 /* might be able to return some write requests if the parity block
2755 * is safe, or on a failed drive
2756 */
2757 dev = &sh->dev[sh->pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07002758 if ( s.written &&
2759 ((test_bit(R5_Insync, &dev->flags) &&
2760 !test_bit(R5_LOCKED, &dev->flags) &&
2761 test_bit(R5_UPTODATE, &dev->flags)) ||
2762 (s.failed == 1 && s.failed_num == sh->pd_idx)))
2763 handle_completed_write_requests(conf, sh, disks, &return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002764
2765 /* Now we might consider reading some blocks, either to check/generate
2766 * parity, or to satisfy requests
2767 * or to load a block that is being partially written.
2768 */
Dan Williamsa4456852007-07-09 11:56:43 -07002769 if (s.to_read || s.non_overwrite ||
Dan Williamsf38e1212007-01-02 13:52:30 -07002770 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding ||
2771 test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002772 handle_issuing_new_read_requests5(sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002773
Dan Williamse33129d2007-01-02 13:52:30 -07002774 /* Now we check to see if any write operations have recently
2775 * completed
2776 */
2777
2778 /* leave prexor set until postxor is done, allows us to distinguish
2779 * a rmw from a rcw during biodrain
2780 */
Dan Williamse0a115e2008-06-05 22:45:52 -07002781 prexor = 0;
Dan Williamse33129d2007-01-02 13:52:30 -07002782 if (test_bit(STRIPE_OP_PREXOR, &sh->ops.complete) &&
2783 test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
2784
Dan Williamse0a115e2008-06-05 22:45:52 -07002785 prexor = 1;
Dan Williamse33129d2007-01-02 13:52:30 -07002786 clear_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
2787 clear_bit(STRIPE_OP_PREXOR, &sh->ops.ack);
2788 clear_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
2789
2790 for (i = disks; i--; )
2791 clear_bit(R5_Wantprexor, &sh->dev[i].flags);
2792 }
2793
2794 /* if only POSTXOR is set then this is an 'expand' postxor */
2795 if (test_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete) &&
2796 test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
2797
2798 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
2799 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.ack);
2800 clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
2801
2802 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
2803 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
2804 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
2805
2806 /* All the 'written' buffers and the parity block are ready to
2807 * be written back to disk
2808 */
2809 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
2810 for (i = disks; i--; ) {
2811 dev = &sh->dev[i];
2812 if (test_bit(R5_LOCKED, &dev->flags) &&
2813 (i == sh->pd_idx || dev->written)) {
2814 pr_debug("Writing block %d\n", i);
2815 set_bit(R5_Wantwrite, &dev->flags);
2816 if (!test_and_set_bit(
2817 STRIPE_OP_IO, &sh->ops.pending))
2818 sh->ops.count++;
Dan Williamse0a115e2008-06-05 22:45:52 -07002819 if (prexor)
2820 continue;
Dan Williamse33129d2007-01-02 13:52:30 -07002821 if (!test_bit(R5_Insync, &dev->flags) ||
2822 (i == sh->pd_idx && s.failed == 0))
2823 set_bit(STRIPE_INSYNC, &sh->state);
2824 }
2825 }
2826 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2827 atomic_dec(&conf->preread_active_stripes);
2828 if (atomic_read(&conf->preread_active_stripes) <
2829 IO_THRESHOLD)
2830 md_wakeup_thread(conf->mddev->thread);
2831 }
2832 }
2833
2834 /* Now to consider new write requests and what else, if anything
2835 * should be read. We do not handle new writes when:
2836 * 1/ A 'write' operation (copy+xor) is already in flight.
2837 * 2/ A 'check' operation is in flight, as it may clobber the parity
2838 * block.
2839 */
2840 if (s.to_write && !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending) &&
2841 !test_bit(STRIPE_OP_CHECK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002842 handle_issuing_new_write_requests5(conf, sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002843
2844 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamse89f8962007-01-02 13:52:31 -07002845 * Any reads will already have been scheduled, so we just see if enough
2846 * data is available. The parity check is held off while parity
2847 * dependent operations are in flight.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002848 */
Dan Williamse89f8962007-01-02 13:52:31 -07002849 if ((s.syncing && s.locked == 0 &&
2850 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending) &&
2851 !test_bit(STRIPE_INSYNC, &sh->state)) ||
2852 test_bit(STRIPE_OP_CHECK, &sh->ops.pending) ||
2853 test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002854 handle_parity_checks5(conf, sh, &s, disks);
Dan Williamse89f8962007-01-02 13:52:31 -07002855
Dan Williamsa4456852007-07-09 11:56:43 -07002856 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002857 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2858 clear_bit(STRIPE_SYNCING, &sh->state);
2859 }
NeilBrown4e5314b2005-11-08 21:39:22 -08002860
2861 /* If the failed drive is just a ReadError, then we might need to progress
2862 * the repair/check process
2863 */
Dan Williamsa4456852007-07-09 11:56:43 -07002864 if (s.failed == 1 && !conf->mddev->ro &&
2865 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2866 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2867 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08002868 ) {
Dan Williamsa4456852007-07-09 11:56:43 -07002869 dev = &sh->dev[s.failed_num];
NeilBrown4e5314b2005-11-08 21:39:22 -08002870 if (!test_bit(R5_ReWrite, &dev->flags)) {
2871 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002872 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2873 sh->ops.count++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002874 set_bit(R5_ReWrite, &dev->flags);
2875 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002876 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002877 } else {
2878 /* let's read it back */
2879 set_bit(R5_Wantread, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002880 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2881 sh->ops.count++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002882 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07002883 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08002884 }
2885 }
2886
Dan Williamsf0a50d32007-01-02 13:52:31 -07002887 /* Finish postxor operations initiated by the expansion
2888 * process
2889 */
2890 if (test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete) &&
2891 !test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending)) {
2892
2893 clear_bit(STRIPE_EXPANDING, &sh->state);
2894
2895 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
2896 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
2897 clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
2898
2899 for (i = conf->raid_disks; i--; ) {
2900 set_bit(R5_Wantwrite, &sh->dev[i].flags);
Neil Brownefe31142008-06-28 08:31:14 +10002901 set_bit(R5_LOCKED, &dev->flags);
2902 s.locked++;
Dan Williamsf0a50d32007-01-02 13:52:31 -07002903 if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
2904 sh->ops.count++;
2905 }
2906 }
2907
2908 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
2909 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002910 /* Need to write out all blocks after computing parity */
2911 sh->disks = conf->raid_disks;
Dan Williamsf0a50d32007-01-02 13:52:31 -07002912 sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
2913 conf->raid_disks);
NeilBrowna2e08552007-09-11 15:23:36 -07002914 s.locked += handle_write_operations5(sh, 1, 1);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002915 } else if (s.expanded &&
Neil Brownefe31142008-06-28 08:31:14 +10002916 s.locked == 0 &&
Dan Williamsf0a50d32007-01-02 13:52:31 -07002917 !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08002918 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08002919 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002920 wake_up(&conf->wait_for_overlap);
2921 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2922 }
2923
Dan Williams0f94e872008-01-08 15:32:53 -08002924 if (s.expanding && s.locked == 0 &&
2925 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07002926 handle_stripe_expansion(conf, sh, NULL);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002927
Dan Williamsd84e0f12007-01-02 13:52:30 -07002928 if (sh->ops.count)
2929 pending = get_stripe_work(sh);
2930
Dan Williams6bfe0b42008-04-30 00:52:32 -07002931 unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002932 spin_unlock(&sh->lock);
2933
Dan Williams6bfe0b42008-04-30 00:52:32 -07002934 /* wait for this device to become unblocked */
2935 if (unlikely(blocked_rdev))
2936 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
2937
Dan Williamsd84e0f12007-01-02 13:52:30 -07002938 if (pending)
2939 raid5_run_ops(sh, pending);
2940
Dan Williamsa4456852007-07-09 11:56:43 -07002941 return_io(return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002942
Linus Torvalds1da177e2005-04-16 15:20:36 -07002943}
2944
NeilBrown16a53ec2006-06-26 00:27:38 -07002945static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
2946{
2947 raid6_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08002948 int disks = sh->disks;
Dan Williamsa4456852007-07-09 11:56:43 -07002949 struct bio *return_bi = NULL;
2950 int i, pd_idx = sh->pd_idx;
2951 struct stripe_head_state s;
2952 struct r6_state r6s;
NeilBrown16a53ec2006-06-26 00:27:38 -07002953 struct r5dev *dev, *pdev, *qdev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002954 mdk_rdev_t *blocked_rdev = NULL;
NeilBrown16a53ec2006-06-26 00:27:38 -07002955
Dan Williamsa4456852007-07-09 11:56:43 -07002956 r6s.qd_idx = raid6_next_disk(pd_idx, disks);
Dan Williams45b42332007-07-09 11:56:43 -07002957 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
Dan Williamsa4456852007-07-09 11:56:43 -07002958 "pd_idx=%d, qd_idx=%d\n",
2959 (unsigned long long)sh->sector, sh->state,
2960 atomic_read(&sh->count), pd_idx, r6s.qd_idx);
2961 memset(&s, 0, sizeof(s));
NeilBrown16a53ec2006-06-26 00:27:38 -07002962
2963 spin_lock(&sh->lock);
2964 clear_bit(STRIPE_HANDLE, &sh->state);
2965 clear_bit(STRIPE_DELAYED, &sh->state);
2966
Dan Williamsa4456852007-07-09 11:56:43 -07002967 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2968 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2969 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrown16a53ec2006-06-26 00:27:38 -07002970 /* Now to look around and see what can be done */
2971
2972 rcu_read_lock();
2973 for (i=disks; i--; ) {
2974 mdk_rdev_t *rdev;
2975 dev = &sh->dev[i];
2976 clear_bit(R5_Insync, &dev->flags);
2977
Dan Williams45b42332007-07-09 11:56:43 -07002978 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07002979 i, dev->flags, dev->toread, dev->towrite, dev->written);
2980 /* maybe we can reply to a read */
2981 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
2982 struct bio *rbi, *rbi2;
Dan Williams45b42332007-07-09 11:56:43 -07002983 pr_debug("Return read for disc %d\n", i);
NeilBrown16a53ec2006-06-26 00:27:38 -07002984 spin_lock_irq(&conf->device_lock);
2985 rbi = dev->toread;
2986 dev->toread = NULL;
2987 if (test_and_clear_bit(R5_Overlap, &dev->flags))
2988 wake_up(&conf->wait_for_overlap);
2989 spin_unlock_irq(&conf->device_lock);
2990 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2991 copy_data(0, rbi, dev->page, dev->sector);
2992 rbi2 = r5_next_bio(rbi, dev->sector);
2993 spin_lock_irq(&conf->device_lock);
2994 if (--rbi->bi_phys_segments == 0) {
2995 rbi->bi_next = return_bi;
2996 return_bi = rbi;
2997 }
2998 spin_unlock_irq(&conf->device_lock);
2999 rbi = rbi2;
3000 }
3001 }
3002
3003 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07003004 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3005 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003006
3007
Dan Williamsa4456852007-07-09 11:56:43 -07003008 if (dev->toread)
3009 s.to_read++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003010 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07003011 s.to_write++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003012 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07003013 s.non_overwrite++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003014 }
Dan Williamsa4456852007-07-09 11:56:43 -07003015 if (dev->written)
3016 s.written++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003017 rdev = rcu_dereference(conf->disks[i].rdev);
Dan Williams6bfe0b42008-04-30 00:52:32 -07003018 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3019 blocked_rdev = rdev;
3020 atomic_inc(&rdev->nr_pending);
3021 break;
3022 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003023 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
3024 /* The ReadError flag will just be confusing now */
3025 clear_bit(R5_ReadError, &dev->flags);
3026 clear_bit(R5_ReWrite, &dev->flags);
3027 }
3028 if (!rdev || !test_bit(In_sync, &rdev->flags)
3029 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07003030 if (s.failed < 2)
3031 r6s.failed_num[s.failed] = i;
3032 s.failed++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003033 } else
3034 set_bit(R5_Insync, &dev->flags);
3035 }
3036 rcu_read_unlock();
Dan Williams6bfe0b42008-04-30 00:52:32 -07003037
3038 if (unlikely(blocked_rdev)) {
3039 set_bit(STRIPE_HANDLE, &sh->state);
3040 goto unlock;
3041 }
Dan Williams45b42332007-07-09 11:56:43 -07003042 pr_debug("locked=%d uptodate=%d to_read=%d"
NeilBrown16a53ec2006-06-26 00:27:38 -07003043 " to_write=%d failed=%d failed_num=%d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003044 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3045 r6s.failed_num[0], r6s.failed_num[1]);
3046 /* check if the array has lost >2 devices and, if so, some requests
3047 * might need to be failed
NeilBrown16a53ec2006-06-26 00:27:38 -07003048 */
Dan Williamsa4456852007-07-09 11:56:43 -07003049 if (s.failed > 2 && s.to_read+s.to_write+s.written)
3050 handle_requests_to_failed_array(conf, sh, &s, disks,
3051 &return_bi);
3052 if (s.failed > 2 && s.syncing) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003053 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3054 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003055 s.syncing = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07003056 }
3057
3058 /*
3059 * might be able to return some write requests if the parity blocks
3060 * are safe, or on a failed drive
3061 */
3062 pdev = &sh->dev[pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07003063 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3064 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
3065 qdev = &sh->dev[r6s.qd_idx];
3066 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == r6s.qd_idx)
3067 || (s.failed >= 2 && r6s.failed_num[1] == r6s.qd_idx);
NeilBrown16a53ec2006-06-26 00:27:38 -07003068
Dan Williamsa4456852007-07-09 11:56:43 -07003069 if ( s.written &&
3070 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003071 && !test_bit(R5_LOCKED, &pdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003072 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3073 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003074 && !test_bit(R5_LOCKED, &qdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003075 && test_bit(R5_UPTODATE, &qdev->flags)))))
3076 handle_completed_write_requests(conf, sh, disks, &return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003077
3078 /* Now we might consider reading some blocks, either to check/generate
3079 * parity, or to satisfy requests
3080 * or to load a block that is being partially written.
3081 */
Dan Williamsa4456852007-07-09 11:56:43 -07003082 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3083 (s.syncing && (s.uptodate < disks)) || s.expanding)
3084 handle_issuing_new_read_requests6(sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003085
3086 /* now to consider writing and what else, if anything should be read */
Dan Williamsa4456852007-07-09 11:56:43 -07003087 if (s.to_write)
3088 handle_issuing_new_write_requests6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003089
3090 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamsa4456852007-07-09 11:56:43 -07003091 * Any reads will already have been scheduled, so we just see if enough
3092 * data is available
NeilBrown16a53ec2006-06-26 00:27:38 -07003093 */
Dan Williamsa4456852007-07-09 11:56:43 -07003094 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
3095 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003096
Dan Williamsa4456852007-07-09 11:56:43 -07003097 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003098 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3099 clear_bit(STRIPE_SYNCING, &sh->state);
3100 }
3101
3102 /* If the failed drives are just a ReadError, then we might need
3103 * to progress the repair/check process
3104 */
Dan Williamsa4456852007-07-09 11:56:43 -07003105 if (s.failed <= 2 && !conf->mddev->ro)
3106 for (i = 0; i < s.failed; i++) {
3107 dev = &sh->dev[r6s.failed_num[i]];
NeilBrown16a53ec2006-06-26 00:27:38 -07003108 if (test_bit(R5_ReadError, &dev->flags)
3109 && !test_bit(R5_LOCKED, &dev->flags)
3110 && test_bit(R5_UPTODATE, &dev->flags)
3111 ) {
3112 if (!test_bit(R5_ReWrite, &dev->flags)) {
3113 set_bit(R5_Wantwrite, &dev->flags);
3114 set_bit(R5_ReWrite, &dev->flags);
3115 set_bit(R5_LOCKED, &dev->flags);
3116 } else {
3117 /* let's read it back */
3118 set_bit(R5_Wantread, &dev->flags);
3119 set_bit(R5_LOCKED, &dev->flags);
3120 }
3121 }
3122 }
NeilBrownf4168852007-02-28 20:11:53 -08003123
Dan Williamsa4456852007-07-09 11:56:43 -07003124 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
NeilBrownf4168852007-02-28 20:11:53 -08003125 /* Need to write out all blocks after computing P&Q */
3126 sh->disks = conf->raid_disks;
3127 sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
3128 conf->raid_disks);
3129 compute_parity6(sh, RECONSTRUCT_WRITE);
3130 for (i = conf->raid_disks ; i-- ; ) {
3131 set_bit(R5_LOCKED, &sh->dev[i].flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003132 s.locked++;
NeilBrownf4168852007-02-28 20:11:53 -08003133 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3134 }
3135 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003136 } else if (s.expanded) {
NeilBrownf4168852007-02-28 20:11:53 -08003137 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3138 atomic_dec(&conf->reshape_stripes);
3139 wake_up(&conf->wait_for_overlap);
3140 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3141 }
3142
Dan Williams0f94e872008-01-08 15:32:53 -08003143 if (s.expanding && s.locked == 0 &&
3144 !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
Dan Williamsa4456852007-07-09 11:56:43 -07003145 handle_stripe_expansion(conf, sh, &r6s);
NeilBrownf4168852007-02-28 20:11:53 -08003146
Dan Williams6bfe0b42008-04-30 00:52:32 -07003147 unlock:
NeilBrown16a53ec2006-06-26 00:27:38 -07003148 spin_unlock(&sh->lock);
3149
Dan Williams6bfe0b42008-04-30 00:52:32 -07003150 /* wait for this device to become unblocked */
3151 if (unlikely(blocked_rdev))
3152 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3153
Dan Williamsa4456852007-07-09 11:56:43 -07003154 return_io(return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003155
NeilBrown16a53ec2006-06-26 00:27:38 -07003156 for (i=disks; i-- ;) {
3157 int rw;
3158 struct bio *bi;
3159 mdk_rdev_t *rdev;
3160 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08003161 rw = WRITE;
NeilBrown16a53ec2006-06-26 00:27:38 -07003162 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
NeilBrown802ba062006-12-13 00:34:13 -08003163 rw = READ;
NeilBrown16a53ec2006-06-26 00:27:38 -07003164 else
3165 continue;
3166
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003167 set_bit(STRIPE_IO_STARTED, &sh->state);
3168
NeilBrown16a53ec2006-06-26 00:27:38 -07003169 bi = &sh->dev[i].req;
3170
3171 bi->bi_rw = rw;
NeilBrown802ba062006-12-13 00:34:13 -08003172 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07003173 bi->bi_end_io = raid5_end_write_request;
3174 else
3175 bi->bi_end_io = raid5_end_read_request;
3176
3177 rcu_read_lock();
3178 rdev = rcu_dereference(conf->disks[i].rdev);
3179 if (rdev && test_bit(Faulty, &rdev->flags))
3180 rdev = NULL;
3181 if (rdev)
3182 atomic_inc(&rdev->nr_pending);
3183 rcu_read_unlock();
3184
3185 if (rdev) {
Dan Williamsa4456852007-07-09 11:56:43 -07003186 if (s.syncing || s.expanding || s.expanded)
NeilBrown16a53ec2006-06-26 00:27:38 -07003187 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
3188
3189 bi->bi_bdev = rdev->bdev;
Dan Williams45b42332007-07-09 11:56:43 -07003190 pr_debug("for %llu schedule op %ld on disc %d\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003191 (unsigned long long)sh->sector, bi->bi_rw, i);
3192 atomic_inc(&sh->count);
3193 bi->bi_sector = sh->sector + rdev->data_offset;
3194 bi->bi_flags = 1 << BIO_UPTODATE;
3195 bi->bi_vcnt = 1;
3196 bi->bi_max_vecs = 1;
3197 bi->bi_idx = 0;
3198 bi->bi_io_vec = &sh->dev[i].vec;
3199 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
3200 bi->bi_io_vec[0].bv_offset = 0;
3201 bi->bi_size = STRIPE_SIZE;
3202 bi->bi_next = NULL;
3203 if (rw == WRITE &&
3204 test_bit(R5_ReWrite, &sh->dev[i].flags))
3205 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
3206 generic_make_request(bi);
3207 } else {
NeilBrown802ba062006-12-13 00:34:13 -08003208 if (rw == WRITE)
NeilBrown16a53ec2006-06-26 00:27:38 -07003209 set_bit(STRIPE_DEGRADED, &sh->state);
Dan Williams45b42332007-07-09 11:56:43 -07003210 pr_debug("skip op %ld on disc %d for sector %llu\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003211 bi->bi_rw, i, (unsigned long long)sh->sector);
3212 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3213 set_bit(STRIPE_HANDLE, &sh->state);
3214 }
3215 }
3216}
3217
3218static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
3219{
3220 if (sh->raid_conf->level == 6)
3221 handle_stripe6(sh, tmp_page);
3222 else
3223 handle_stripe5(sh);
3224}
3225
3226
3227
Arjan van de Ven858119e2006-01-14 13:20:43 -08003228static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003229{
3230 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3231 while (!list_empty(&conf->delayed_list)) {
3232 struct list_head *l = conf->delayed_list.next;
3233 struct stripe_head *sh;
3234 sh = list_entry(l, struct stripe_head, lru);
3235 list_del_init(l);
3236 clear_bit(STRIPE_DELAYED, &sh->state);
3237 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3238 atomic_inc(&conf->preread_active_stripes);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003239 list_add_tail(&sh->lru, &conf->hold_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003240 }
NeilBrown6ed30032008-02-06 01:40:00 -08003241 } else
3242 blk_plug_device(conf->mddev->queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003243}
3244
Arjan van de Ven858119e2006-01-14 13:20:43 -08003245static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07003246{
3247 /* device_lock is held */
3248 struct list_head head;
3249 list_add(&head, &conf->bitmap_list);
3250 list_del_init(&conf->bitmap_list);
3251 while (!list_empty(&head)) {
3252 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3253 list_del_init(&sh->lru);
3254 atomic_inc(&sh->count);
3255 __release_stripe(conf, sh);
3256 }
3257}
3258
Linus Torvalds1da177e2005-04-16 15:20:36 -07003259static void unplug_slaves(mddev_t *mddev)
3260{
3261 raid5_conf_t *conf = mddev_to_conf(mddev);
3262 int i;
3263
3264 rcu_read_lock();
3265 for (i=0; i<mddev->raid_disks; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08003266 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08003267 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +02003268 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003269
3270 atomic_inc(&rdev->nr_pending);
3271 rcu_read_unlock();
3272
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -05003273 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003274
3275 rdev_dec_pending(rdev, mddev);
3276 rcu_read_lock();
3277 }
3278 }
3279 rcu_read_unlock();
3280}
3281
Jens Axboe165125e2007-07-24 09:28:11 +02003282static void raid5_unplug_device(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003283{
3284 mddev_t *mddev = q->queuedata;
3285 raid5_conf_t *conf = mddev_to_conf(mddev);
3286 unsigned long flags;
3287
3288 spin_lock_irqsave(&conf->device_lock, flags);
3289
NeilBrown72626682005-09-09 16:23:54 -07003290 if (blk_remove_plug(q)) {
3291 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003292 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07003293 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003294 md_wakeup_thread(mddev->thread);
3295
3296 spin_unlock_irqrestore(&conf->device_lock, flags);
3297
3298 unplug_slaves(mddev);
3299}
3300
NeilBrownf022b2f2006-10-03 01:15:56 -07003301static int raid5_congested(void *data, int bits)
3302{
3303 mddev_t *mddev = data;
3304 raid5_conf_t *conf = mddev_to_conf(mddev);
3305
3306 /* No difference between reads and writes. Just check
3307 * how busy the stripe_cache is
3308 */
3309 if (conf->inactive_blocked)
3310 return 1;
3311 if (conf->quiesce)
3312 return 1;
3313 if (list_empty_careful(&conf->inactive_list))
3314 return 1;
3315
3316 return 0;
3317}
3318
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003319/* We want read requests to align with chunks where possible,
3320 * but write requests don't need to.
3321 */
Jens Axboe165125e2007-07-24 09:28:11 +02003322static int raid5_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003323{
3324 mddev_t *mddev = q->queuedata;
3325 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3326 int max;
3327 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3328 unsigned int bio_sectors = bio->bi_size >> 9;
3329
NeilBrown802ba062006-12-13 00:34:13 -08003330 if (bio_data_dir(bio) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003331 return biovec->bv_len; /* always allow writes to be mergeable */
3332
3333 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3334 if (max < 0) max = 0;
3335 if (max <= biovec->bv_len && bio_sectors == 0)
3336 return biovec->bv_len;
3337 else
3338 return max;
3339}
3340
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003341
3342static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3343{
3344 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3345 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3346 unsigned int bio_sectors = bio->bi_size >> 9;
3347
3348 return chunk_sectors >=
3349 ((sector & (chunk_sectors - 1)) + bio_sectors);
3350}
3351
3352/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003353 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3354 * later sampled by raid5d.
3355 */
3356static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3357{
3358 unsigned long flags;
3359
3360 spin_lock_irqsave(&conf->device_lock, flags);
3361
3362 bi->bi_next = conf->retry_read_aligned_list;
3363 conf->retry_read_aligned_list = bi;
3364
3365 spin_unlock_irqrestore(&conf->device_lock, flags);
3366 md_wakeup_thread(conf->mddev->thread);
3367}
3368
3369
3370static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3371{
3372 struct bio *bi;
3373
3374 bi = conf->retry_read_aligned;
3375 if (bi) {
3376 conf->retry_read_aligned = NULL;
3377 return bi;
3378 }
3379 bi = conf->retry_read_aligned_list;
3380 if(bi) {
Neil Brown387bb172007-02-08 14:20:29 -08003381 conf->retry_read_aligned_list = bi->bi_next;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003382 bi->bi_next = NULL;
3383 bi->bi_phys_segments = 1; /* biased count of active stripes */
3384 bi->bi_hw_segments = 0; /* count of processed stripes */
3385 }
3386
3387 return bi;
3388}
3389
3390
3391/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003392 * The "raid5_align_endio" should check if the read succeeded and if it
3393 * did, call bio_endio on the original bio (having bio_put the new bio
3394 * first).
3395 * If the read failed..
3396 */
NeilBrown6712ecf2007-09-27 12:47:43 +02003397static void raid5_align_endio(struct bio *bi, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003398{
3399 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003400 mddev_t *mddev;
3401 raid5_conf_t *conf;
3402 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3403 mdk_rdev_t *rdev;
3404
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003405 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003406
3407 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
3408 conf = mddev_to_conf(mddev);
3409 rdev = (void*)raid_bi->bi_next;
3410 raid_bi->bi_next = NULL;
3411
3412 rdev_dec_pending(rdev, conf->mddev);
3413
3414 if (!error && uptodate) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003415 bio_endio(raid_bi, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003416 if (atomic_dec_and_test(&conf->active_aligned_reads))
3417 wake_up(&conf->wait_for_stripe);
NeilBrown6712ecf2007-09-27 12:47:43 +02003418 return;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003419 }
3420
3421
Dan Williams45b42332007-07-09 11:56:43 -07003422 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003423
3424 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003425}
3426
Neil Brown387bb172007-02-08 14:20:29 -08003427static int bio_fits_rdev(struct bio *bi)
3428{
Jens Axboe165125e2007-07-24 09:28:11 +02003429 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
Neil Brown387bb172007-02-08 14:20:29 -08003430
3431 if ((bi->bi_size>>9) > q->max_sectors)
3432 return 0;
3433 blk_recount_segments(q, bi);
3434 if (bi->bi_phys_segments > q->max_phys_segments ||
3435 bi->bi_hw_segments > q->max_hw_segments)
3436 return 0;
3437
3438 if (q->merge_bvec_fn)
3439 /* it's too hard to apply the merge_bvec_fn at this stage,
3440 * just just give up
3441 */
3442 return 0;
3443
3444 return 1;
3445}
3446
3447
Jens Axboe165125e2007-07-24 09:28:11 +02003448static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003449{
3450 mddev_t *mddev = q->queuedata;
3451 raid5_conf_t *conf = mddev_to_conf(mddev);
3452 const unsigned int raid_disks = conf->raid_disks;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003453 const unsigned int data_disks = raid_disks - conf->max_degraded;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003454 unsigned int dd_idx, pd_idx;
3455 struct bio* align_bi;
3456 mdk_rdev_t *rdev;
3457
3458 if (!in_chunk_boundary(mddev, raid_bio)) {
Dan Williams45b42332007-07-09 11:56:43 -07003459 pr_debug("chunk_aligned_read : non aligned\n");
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003460 return 0;
3461 }
3462 /*
3463 * use bio_clone to make a copy of the bio
3464 */
3465 align_bi = bio_clone(raid_bio, GFP_NOIO);
3466 if (!align_bi)
3467 return 0;
3468 /*
3469 * set bi_end_io to a new function, and set bi_private to the
3470 * original bio.
3471 */
3472 align_bi->bi_end_io = raid5_align_endio;
3473 align_bi->bi_private = raid_bio;
3474 /*
3475 * compute position
3476 */
3477 align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector,
3478 raid_disks,
3479 data_disks,
3480 &dd_idx,
3481 &pd_idx,
3482 conf);
3483
3484 rcu_read_lock();
3485 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3486 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003487 atomic_inc(&rdev->nr_pending);
3488 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003489 raid_bio->bi_next = (void*)rdev;
3490 align_bi->bi_bdev = rdev->bdev;
3491 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3492 align_bi->bi_sector += rdev->data_offset;
3493
Neil Brown387bb172007-02-08 14:20:29 -08003494 if (!bio_fits_rdev(align_bi)) {
3495 /* too big in some way */
3496 bio_put(align_bi);
3497 rdev_dec_pending(rdev, mddev);
3498 return 0;
3499 }
3500
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003501 spin_lock_irq(&conf->device_lock);
3502 wait_event_lock_irq(conf->wait_for_stripe,
3503 conf->quiesce == 0,
3504 conf->device_lock, /* nothing */);
3505 atomic_inc(&conf->active_aligned_reads);
3506 spin_unlock_irq(&conf->device_lock);
3507
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003508 generic_make_request(align_bi);
3509 return 1;
3510 } else {
3511 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003512 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003513 return 0;
3514 }
3515}
3516
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003517/* __get_priority_stripe - get the next stripe to process
3518 *
3519 * Full stripe writes are allowed to pass preread active stripes up until
3520 * the bypass_threshold is exceeded. In general the bypass_count
3521 * increments when the handle_list is handled before the hold_list; however, it
3522 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3523 * stripe with in flight i/o. The bypass_count will be reset when the
3524 * head of the hold_list has changed, i.e. the head was promoted to the
3525 * handle_list.
3526 */
3527static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3528{
3529 struct stripe_head *sh;
3530
3531 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3532 __func__,
3533 list_empty(&conf->handle_list) ? "empty" : "busy",
3534 list_empty(&conf->hold_list) ? "empty" : "busy",
3535 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3536
3537 if (!list_empty(&conf->handle_list)) {
3538 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3539
3540 if (list_empty(&conf->hold_list))
3541 conf->bypass_count = 0;
3542 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3543 if (conf->hold_list.next == conf->last_hold)
3544 conf->bypass_count++;
3545 else {
3546 conf->last_hold = conf->hold_list.next;
3547 conf->bypass_count -= conf->bypass_threshold;
3548 if (conf->bypass_count < 0)
3549 conf->bypass_count = 0;
3550 }
3551 }
3552 } else if (!list_empty(&conf->hold_list) &&
3553 ((conf->bypass_threshold &&
3554 conf->bypass_count > conf->bypass_threshold) ||
3555 atomic_read(&conf->pending_full_writes) == 0)) {
3556 sh = list_entry(conf->hold_list.next,
3557 typeof(*sh), lru);
3558 conf->bypass_count -= conf->bypass_threshold;
3559 if (conf->bypass_count < 0)
3560 conf->bypass_count = 0;
3561 } else
3562 return NULL;
3563
3564 list_del_init(&sh->lru);
3565 atomic_inc(&sh->count);
3566 BUG_ON(atomic_read(&sh->count) != 1);
3567 return sh;
3568}
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003569
Jens Axboe165125e2007-07-24 09:28:11 +02003570static int make_request(struct request_queue *q, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003571{
3572 mddev_t *mddev = q->queuedata;
3573 raid5_conf_t *conf = mddev_to_conf(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003574 unsigned int dd_idx, pd_idx;
3575 sector_t new_sector;
3576 sector_t logical_sector, last_sector;
3577 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01003578 const int rw = bio_data_dir(bi);
NeilBrownf6344752006-03-27 01:18:17 -08003579 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003580
NeilBrowne5dcdd82005-09-09 16:23:41 -07003581 if (unlikely(bio_barrier(bi))) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003582 bio_endio(bi, -EOPNOTSUPP);
NeilBrowne5dcdd82005-09-09 16:23:41 -07003583 return 0;
3584 }
3585
NeilBrown3d310eb2005-06-21 17:17:26 -07003586 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07003587
Jens Axboea3623572005-11-01 09:26:16 +01003588 disk_stat_inc(mddev->gendisk, ios[rw]);
3589 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003590
NeilBrown802ba062006-12-13 00:34:13 -08003591 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003592 mddev->reshape_position == MaxSector &&
3593 chunk_aligned_read(q,bi))
3594 return 0;
3595
Linus Torvalds1da177e2005-04-16 15:20:36 -07003596 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3597 last_sector = bi->bi_sector + (bi->bi_size>>9);
3598 bi->bi_next = NULL;
3599 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07003600
Linus Torvalds1da177e2005-04-16 15:20:36 -07003601 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3602 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07003603 int disks, data_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003604
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003605 retry:
NeilBrownb578d552006-03-27 01:18:12 -08003606 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003607 if (likely(conf->expand_progress == MaxSector))
3608 disks = conf->raid_disks;
3609 else {
NeilBrowndf8e7f72006-03-27 01:18:15 -08003610 /* spinlock is needed as expand_progress may be
3611 * 64bit on a 32bit platform, and so it might be
3612 * possible to see a half-updated value
3613 * Ofcourse expand_progress could change after
3614 * the lock is dropped, so once we get a reference
3615 * to the stripe that we think it is, we will have
3616 * to check again.
3617 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003618 spin_lock_irq(&conf->device_lock);
3619 disks = conf->raid_disks;
3620 if (logical_sector >= conf->expand_progress)
3621 disks = conf->previous_raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003622 else {
3623 if (logical_sector >= conf->expand_lo) {
3624 spin_unlock_irq(&conf->device_lock);
3625 schedule();
3626 goto retry;
3627 }
3628 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003629 spin_unlock_irq(&conf->device_lock);
3630 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003631 data_disks = disks - conf->max_degraded;
3632
3633 new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003634 &dd_idx, &pd_idx, conf);
Dan Williams45b42332007-07-09 11:56:43 -07003635 pr_debug("raid5: make_request, sector %llu logical %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07003636 (unsigned long long)new_sector,
3637 (unsigned long long)logical_sector);
3638
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003639 sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003640 if (sh) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003641 if (unlikely(conf->expand_progress != MaxSector)) {
3642 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08003643 * stripe, so we must do the range check again.
3644 * Expansion could still move past after this
3645 * test, but as we are holding a reference to
3646 * 'sh', we know that if that happens,
3647 * STRIPE_EXPANDING will get set and the expansion
3648 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003649 */
3650 int must_retry = 0;
3651 spin_lock_irq(&conf->device_lock);
3652 if (logical_sector < conf->expand_progress &&
3653 disks == conf->previous_raid_disks)
3654 /* mismatch, need to try again */
3655 must_retry = 1;
3656 spin_unlock_irq(&conf->device_lock);
3657 if (must_retry) {
3658 release_stripe(sh);
3659 goto retry;
3660 }
3661 }
NeilBrowne464eaf2006-03-27 01:18:14 -08003662 /* FIXME what if we get a false positive because these
3663 * are being updated.
3664 */
3665 if (logical_sector >= mddev->suspend_lo &&
3666 logical_sector < mddev->suspend_hi) {
3667 release_stripe(sh);
3668 schedule();
3669 goto retry;
3670 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003671
3672 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3673 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3674 /* Stripe is busy expanding or
3675 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07003676 * and wait a while
3677 */
3678 raid5_unplug_device(mddev->queue);
3679 release_stripe(sh);
3680 schedule();
3681 goto retry;
3682 }
3683 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown6ed30032008-02-06 01:40:00 -08003684 set_bit(STRIPE_HANDLE, &sh->state);
3685 clear_bit(STRIPE_DELAYED, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003686 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003687 } else {
3688 /* cannot get stripe for read-ahead, just give-up */
3689 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3690 finish_wait(&conf->wait_for_overlap, &w);
3691 break;
3692 }
3693
3694 }
3695 spin_lock_irq(&conf->device_lock);
NeilBrownf6344752006-03-27 01:18:17 -08003696 remaining = --bi->bi_phys_segments;
3697 spin_unlock_irq(&conf->device_lock);
3698 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003699
NeilBrown16a53ec2006-06-26 00:27:38 -07003700 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07003701 md_write_end(mddev);
NeilBrown6712ecf2007-09-27 12:47:43 +02003702
3703 bi->bi_end_io(bi,
NeilBrownc2b00852006-12-10 02:20:51 -08003704 test_bit(BIO_UPTODATE, &bi->bi_flags)
3705 ? 0 : -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003706 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003707 return 0;
3708}
3709
NeilBrown52c03292006-06-26 00:27:43 -07003710static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003711{
NeilBrown52c03292006-06-26 00:27:43 -07003712 /* reshaping is quite different to recovery/resync so it is
3713 * handled quite separately ... here.
3714 *
3715 * On each call to sync_request, we gather one chunk worth of
3716 * destination stripes and flag them as expanding.
3717 * Then we find all the source stripes and request reads.
3718 * As the reads complete, handle_stripe will copy the data
3719 * into the destination stripe and release that stripe.
3720 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003721 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3722 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08003723 int pd_idx;
3724 sector_t first_sector, last_sector;
NeilBrownf4168852007-02-28 20:11:53 -08003725 int raid_disks = conf->previous_raid_disks;
3726 int data_disks = raid_disks - conf->max_degraded;
3727 int new_data_disks = conf->raid_disks - conf->max_degraded;
NeilBrown52c03292006-06-26 00:27:43 -07003728 int i;
3729 int dd_idx;
3730 sector_t writepos, safepos, gap;
3731
3732 if (sector_nr == 0 &&
3733 conf->expand_progress != 0) {
3734 /* restarting in the middle, skip the initial sectors */
3735 sector_nr = conf->expand_progress;
NeilBrownf4168852007-02-28 20:11:53 -08003736 sector_div(sector_nr, new_data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003737 *skipped = 1;
3738 return sector_nr;
3739 }
3740
3741 /* we update the metadata when there is more than 3Meg
3742 * in the block range (that is rather arbitrary, should
3743 * probably be time based) or when the data about to be
3744 * copied would over-write the source of the data at
3745 * the front of the range.
3746 * i.e. one new_stripe forward from expand_progress new_maps
3747 * to after where expand_lo old_maps to
3748 */
3749 writepos = conf->expand_progress +
NeilBrownf4168852007-02-28 20:11:53 -08003750 conf->chunk_size/512*(new_data_disks);
3751 sector_div(writepos, new_data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003752 safepos = conf->expand_lo;
NeilBrownf4168852007-02-28 20:11:53 -08003753 sector_div(safepos, data_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003754 gap = conf->expand_progress - conf->expand_lo;
3755
3756 if (writepos >= safepos ||
NeilBrownf4168852007-02-28 20:11:53 -08003757 gap > (new_data_disks)*3000*2 /*3Meg*/) {
NeilBrown52c03292006-06-26 00:27:43 -07003758 /* Cannot proceed until we've updated the superblock... */
3759 wait_event(conf->wait_for_overlap,
3760 atomic_read(&conf->reshape_stripes)==0);
3761 mddev->reshape_position = conf->expand_progress;
NeilBrown850b2b42006-10-03 01:15:46 -07003762 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07003763 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07003764 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07003765 kthread_should_stop());
3766 spin_lock_irq(&conf->device_lock);
3767 conf->expand_lo = mddev->reshape_position;
3768 spin_unlock_irq(&conf->device_lock);
3769 wake_up(&conf->wait_for_overlap);
3770 }
3771
3772 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
3773 int j;
3774 int skipped = 0;
3775 pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
3776 sh = get_active_stripe(conf, sector_nr+i,
3777 conf->raid_disks, pd_idx, 0);
3778 set_bit(STRIPE_EXPANDING, &sh->state);
3779 atomic_inc(&conf->reshape_stripes);
3780 /* If any of this stripe is beyond the end of the old
3781 * array, then we need to zero those blocks
3782 */
3783 for (j=sh->disks; j--;) {
3784 sector_t s;
3785 if (j == sh->pd_idx)
3786 continue;
NeilBrownf4168852007-02-28 20:11:53 -08003787 if (conf->level == 6 &&
3788 j == raid6_next_disk(sh->pd_idx, sh->disks))
3789 continue;
NeilBrown52c03292006-06-26 00:27:43 -07003790 s = compute_blocknr(sh, j);
3791 if (s < (mddev->array_size<<1)) {
3792 skipped = 1;
3793 continue;
3794 }
3795 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3796 set_bit(R5_Expanded, &sh->dev[j].flags);
3797 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3798 }
3799 if (!skipped) {
3800 set_bit(STRIPE_EXPAND_READY, &sh->state);
3801 set_bit(STRIPE_HANDLE, &sh->state);
3802 }
3803 release_stripe(sh);
3804 }
3805 spin_lock_irq(&conf->device_lock);
NeilBrown6d3baf22007-03-05 00:30:44 -08003806 conf->expand_progress = (sector_nr + i) * new_data_disks;
NeilBrown52c03292006-06-26 00:27:43 -07003807 spin_unlock_irq(&conf->device_lock);
3808 /* Ok, those stripe are ready. We can start scheduling
3809 * reads on the source stripes.
3810 * The source stripes are determined by mapping the first and last
3811 * block on the destination stripes.
3812 */
NeilBrown52c03292006-06-26 00:27:43 -07003813 first_sector =
NeilBrownf4168852007-02-28 20:11:53 -08003814 raid5_compute_sector(sector_nr*(new_data_disks),
NeilBrown52c03292006-06-26 00:27:43 -07003815 raid_disks, data_disks,
3816 &dd_idx, &pd_idx, conf);
3817 last_sector =
3818 raid5_compute_sector((sector_nr+conf->chunk_size/512)
NeilBrownf4168852007-02-28 20:11:53 -08003819 *(new_data_disks) -1,
NeilBrown52c03292006-06-26 00:27:43 -07003820 raid_disks, data_disks,
3821 &dd_idx, &pd_idx, conf);
3822 if (last_sector >= (mddev->size<<1))
3823 last_sector = (mddev->size<<1)-1;
3824 while (first_sector <= last_sector) {
NeilBrownf4168852007-02-28 20:11:53 -08003825 pd_idx = stripe_to_pdidx(first_sector, conf,
3826 conf->previous_raid_disks);
NeilBrown52c03292006-06-26 00:27:43 -07003827 sh = get_active_stripe(conf, first_sector,
3828 conf->previous_raid_disks, pd_idx, 0);
3829 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3830 set_bit(STRIPE_HANDLE, &sh->state);
3831 release_stripe(sh);
3832 first_sector += STRIPE_SECTORS;
3833 }
NeilBrownc6207272008-02-06 01:39:52 -08003834 /* If this takes us to the resync_max point where we have to pause,
3835 * then we need to write out the superblock.
3836 */
3837 sector_nr += conf->chunk_size>>9;
3838 if (sector_nr >= mddev->resync_max) {
3839 /* Cannot proceed until we've updated the superblock... */
3840 wait_event(conf->wait_for_overlap,
3841 atomic_read(&conf->reshape_stripes) == 0);
3842 mddev->reshape_position = conf->expand_progress;
3843 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3844 md_wakeup_thread(mddev->thread);
3845 wait_event(mddev->sb_wait,
3846 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3847 || kthread_should_stop());
3848 spin_lock_irq(&conf->device_lock);
3849 conf->expand_lo = mddev->reshape_position;
3850 spin_unlock_irq(&conf->device_lock);
3851 wake_up(&conf->wait_for_overlap);
3852 }
NeilBrown52c03292006-06-26 00:27:43 -07003853 return conf->chunk_size>>9;
3854}
3855
3856/* FIXME go_faster isn't used */
3857static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3858{
3859 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3860 struct stripe_head *sh;
3861 int pd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003862 int raid_disks = conf->raid_disks;
NeilBrown72626682005-09-09 16:23:54 -07003863 sector_t max_sector = mddev->size << 1;
3864 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07003865 int still_degraded = 0;
3866 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003867
NeilBrown72626682005-09-09 16:23:54 -07003868 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003869 /* just being told to finish up .. nothing much to do */
3870 unplug_slaves(mddev);
NeilBrown29269552006-03-27 01:18:10 -08003871 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3872 end_reshape(conf);
3873 return 0;
3874 }
NeilBrown72626682005-09-09 16:23:54 -07003875
3876 if (mddev->curr_resync < max_sector) /* aborted */
3877 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3878 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07003879 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07003880 conf->fullsync = 0;
3881 bitmap_close_sync(mddev->bitmap);
3882
Linus Torvalds1da177e2005-04-16 15:20:36 -07003883 return 0;
3884 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08003885
NeilBrown52c03292006-06-26 00:27:43 -07003886 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3887 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08003888
NeilBrownc6207272008-02-06 01:39:52 -08003889 /* No need to check resync_max as we never do more than one
3890 * stripe, and as resync_max will always be on a chunk boundary,
3891 * if the check in md_do_sync didn't fire, there is no chance
3892 * of overstepping resync_max here
3893 */
3894
NeilBrown16a53ec2006-06-26 00:27:38 -07003895 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07003896 * to resync, then assert that we are finished, because there is
3897 * nothing we can do.
3898 */
NeilBrown3285edf2006-06-26 00:27:55 -07003899 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07003900 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
NeilBrown57afd892005-06-21 17:17:13 -07003901 sector_t rv = (mddev->size << 1) - sector_nr;
3902 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003903 return rv;
3904 }
NeilBrown72626682005-09-09 16:23:54 -07003905 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08003906 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07003907 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3908 /* we can skip this block, and probably more */
3909 sync_blocks /= STRIPE_SECTORS;
3910 *skipped = 1;
3911 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3912 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003913
NeilBrownb47490c2008-02-06 01:39:50 -08003914
3915 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
3916
NeilBrownccfcc3c2006-03-27 01:18:09 -08003917 pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003918 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003919 if (sh == NULL) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003920 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003921 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07003922 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07003923 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08003924 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003925 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003926 /* Need to check if array will still be degraded after recovery/resync
3927 * We don't need to check the 'failed' flag as when that gets set,
3928 * recovery aborts.
3929 */
3930 for (i=0; i<mddev->raid_disks; i++)
3931 if (conf->disks[i].rdev == NULL)
3932 still_degraded = 1;
3933
3934 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
3935
3936 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003937 set_bit(STRIPE_SYNCING, &sh->state);
3938 clear_bit(STRIPE_INSYNC, &sh->state);
3939 spin_unlock(&sh->lock);
3940
NeilBrown16a53ec2006-06-26 00:27:38 -07003941 handle_stripe(sh, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003942 release_stripe(sh);
3943
3944 return STRIPE_SECTORS;
3945}
3946
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003947static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
3948{
3949 /* We may not be able to submit a whole bio at once as there
3950 * may not be enough stripe_heads available.
3951 * We cannot pre-allocate enough stripe_heads as we may need
3952 * more than exist in the cache (if we allow ever large chunks).
3953 * So we do one stripe head at a time and record in
3954 * ->bi_hw_segments how many have been done.
3955 *
3956 * We *know* that this entire raid_bio is in one chunk, so
3957 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3958 */
3959 struct stripe_head *sh;
3960 int dd_idx, pd_idx;
3961 sector_t sector, logical_sector, last_sector;
3962 int scnt = 0;
3963 int remaining;
3964 int handled = 0;
3965
3966 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3967 sector = raid5_compute_sector( logical_sector,
3968 conf->raid_disks,
3969 conf->raid_disks - conf->max_degraded,
3970 &dd_idx,
3971 &pd_idx,
3972 conf);
3973 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
3974
3975 for (; logical_sector < last_sector;
Neil Brown387bb172007-02-08 14:20:29 -08003976 logical_sector += STRIPE_SECTORS,
3977 sector += STRIPE_SECTORS,
3978 scnt++) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003979
3980 if (scnt < raid_bio->bi_hw_segments)
3981 /* already done this stripe */
3982 continue;
3983
3984 sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1);
3985
3986 if (!sh) {
3987 /* failed to get a stripe - must wait */
3988 raid_bio->bi_hw_segments = scnt;
3989 conf->retry_read_aligned = raid_bio;
3990 return handled;
3991 }
3992
3993 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
Neil Brown387bb172007-02-08 14:20:29 -08003994 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
3995 release_stripe(sh);
3996 raid_bio->bi_hw_segments = scnt;
3997 conf->retry_read_aligned = raid_bio;
3998 return handled;
3999 }
4000
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004001 handle_stripe(sh, NULL);
4002 release_stripe(sh);
4003 handled++;
4004 }
4005 spin_lock_irq(&conf->device_lock);
4006 remaining = --raid_bio->bi_phys_segments;
4007 spin_unlock_irq(&conf->device_lock);
4008 if (remaining == 0) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004009
NeilBrown6712ecf2007-09-27 12:47:43 +02004010 raid_bio->bi_end_io(raid_bio,
NeilBrownc2b00852006-12-10 02:20:51 -08004011 test_bit(BIO_UPTODATE, &raid_bio->bi_flags)
4012 ? 0 : -EIO);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004013 }
4014 if (atomic_dec_and_test(&conf->active_aligned_reads))
4015 wake_up(&conf->wait_for_stripe);
4016 return handled;
4017}
4018
4019
4020
Linus Torvalds1da177e2005-04-16 15:20:36 -07004021/*
4022 * This is our raid5 kernel thread.
4023 *
4024 * We scan the hash table for stripes which can be handled now.
4025 * During the scan, completed stripes are saved for us by the interrupt
4026 * handler, so that they will not have to wait for our next wakeup.
4027 */
NeilBrown6ed30032008-02-06 01:40:00 -08004028static void raid5d(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004029{
4030 struct stripe_head *sh;
4031 raid5_conf_t *conf = mddev_to_conf(mddev);
4032 int handled;
4033
Dan Williams45b42332007-07-09 11:56:43 -07004034 pr_debug("+++ raid5d active\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004035
4036 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004037
4038 handled = 0;
4039 spin_lock_irq(&conf->device_lock);
4040 while (1) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004041 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004042
NeilBrownae3c20c2006-07-10 04:44:17 -07004043 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07004044 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08004045 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004046 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08004047 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004048 conf->seq_write = seq;
4049 activate_bit_delay(conf);
4050 }
4051
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004052 while ((bio = remove_bio_from_retry(conf))) {
4053 int ok;
4054 spin_unlock_irq(&conf->device_lock);
4055 ok = retry_aligned_read(conf, bio);
4056 spin_lock_irq(&conf->device_lock);
4057 if (!ok)
4058 break;
4059 handled++;
4060 }
4061
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004062 sh = __get_priority_stripe(conf);
4063
4064 if (!sh) {
Dan Williamsd84e0f12007-01-02 13:52:30 -07004065 async_tx_issue_pending_all();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004066 break;
Dan Williamsd84e0f12007-01-02 13:52:30 -07004067 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004068 spin_unlock_irq(&conf->device_lock);
4069
4070 handled++;
NeilBrown16a53ec2006-06-26 00:27:38 -07004071 handle_stripe(sh, conf->spare_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004072 release_stripe(sh);
4073
4074 spin_lock_irq(&conf->device_lock);
4075 }
Dan Williams45b42332007-07-09 11:56:43 -07004076 pr_debug("%d stripes handled\n", handled);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004077
4078 spin_unlock_irq(&conf->device_lock);
4079
4080 unplug_slaves(mddev);
4081
Dan Williams45b42332007-07-09 11:56:43 -07004082 pr_debug("--- raid5d inactive\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004083}
4084
NeilBrown3f294f42005-11-08 21:39:25 -08004085static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004086raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004087{
NeilBrown007583c2005-11-08 21:39:30 -08004088 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08004089 if (conf)
4090 return sprintf(page, "%d\n", conf->max_nr_stripes);
4091 else
4092 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004093}
4094
4095static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004096raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08004097{
NeilBrown007583c2005-11-08 21:39:30 -08004098 raid5_conf_t *conf = mddev_to_conf(mddev);
Dan Williams4ef197d82008-04-28 02:15:54 -07004099 unsigned long new;
NeilBrown3f294f42005-11-08 21:39:25 -08004100 if (len >= PAGE_SIZE)
4101 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08004102 if (!conf)
4103 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08004104
Dan Williams4ef197d82008-04-28 02:15:54 -07004105 if (strict_strtoul(page, 10, &new))
NeilBrown3f294f42005-11-08 21:39:25 -08004106 return -EINVAL;
4107 if (new <= 16 || new > 32768)
4108 return -EINVAL;
4109 while (new < conf->max_nr_stripes) {
4110 if (drop_one_stripe(conf))
4111 conf->max_nr_stripes--;
4112 else
4113 break;
4114 }
NeilBrown2a2275d2007-01-26 00:57:11 -08004115 md_allow_write(mddev);
NeilBrown3f294f42005-11-08 21:39:25 -08004116 while (new > conf->max_nr_stripes) {
4117 if (grow_one_stripe(conf))
4118 conf->max_nr_stripes++;
4119 else break;
4120 }
4121 return len;
4122}
NeilBrown007583c2005-11-08 21:39:30 -08004123
NeilBrown96de1e62005-11-08 21:39:39 -08004124static struct md_sysfs_entry
4125raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4126 raid5_show_stripe_cache_size,
4127 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08004128
4129static ssize_t
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004130raid5_show_preread_threshold(mddev_t *mddev, char *page)
4131{
4132 raid5_conf_t *conf = mddev_to_conf(mddev);
4133 if (conf)
4134 return sprintf(page, "%d\n", conf->bypass_threshold);
4135 else
4136 return 0;
4137}
4138
4139static ssize_t
4140raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4141{
4142 raid5_conf_t *conf = mddev_to_conf(mddev);
Dan Williams4ef197d82008-04-28 02:15:54 -07004143 unsigned long new;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004144 if (len >= PAGE_SIZE)
4145 return -EINVAL;
4146 if (!conf)
4147 return -ENODEV;
4148
Dan Williams4ef197d82008-04-28 02:15:54 -07004149 if (strict_strtoul(page, 10, &new))
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004150 return -EINVAL;
Dan Williams4ef197d82008-04-28 02:15:54 -07004151 if (new > conf->max_nr_stripes)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004152 return -EINVAL;
4153 conf->bypass_threshold = new;
4154 return len;
4155}
4156
4157static struct md_sysfs_entry
4158raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4159 S_IRUGO | S_IWUSR,
4160 raid5_show_preread_threshold,
4161 raid5_store_preread_threshold);
4162
4163static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08004164stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004165{
NeilBrown007583c2005-11-08 21:39:30 -08004166 raid5_conf_t *conf = mddev_to_conf(mddev);
NeilBrown96de1e62005-11-08 21:39:39 -08004167 if (conf)
4168 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4169 else
4170 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004171}
4172
NeilBrown96de1e62005-11-08 21:39:39 -08004173static struct md_sysfs_entry
4174raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08004175
NeilBrown007583c2005-11-08 21:39:30 -08004176static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08004177 &raid5_stripecache_size.attr,
4178 &raid5_stripecache_active.attr,
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004179 &raid5_preread_bypass_threshold.attr,
NeilBrown3f294f42005-11-08 21:39:25 -08004180 NULL,
4181};
NeilBrown007583c2005-11-08 21:39:30 -08004182static struct attribute_group raid5_attrs_group = {
4183 .name = NULL,
4184 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08004185};
4186
NeilBrown72626682005-09-09 16:23:54 -07004187static int run(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004188{
4189 raid5_conf_t *conf;
4190 int raid_disk, memory;
4191 mdk_rdev_t *rdev;
4192 struct disk_info *disk;
4193 struct list_head *tmp;
NeilBrown02c2de82006-10-03 01:15:47 -07004194 int working_disks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004195
NeilBrown16a53ec2006-06-26 00:27:38 -07004196 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
4197 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
NeilBrown14f8d262006-01-06 00:20:14 -08004198 mdname(mddev), mddev->level);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004199 return -EIO;
4200 }
4201
NeilBrownf6705572006-03-27 01:18:11 -08004202 if (mddev->reshape_position != MaxSector) {
4203 /* Check that we can continue the reshape.
4204 * Currently only disks can change, it must
4205 * increase, and we must be past the point where
4206 * a stripe over-writes itself
4207 */
4208 sector_t here_new, here_old;
4209 int old_disks;
NeilBrownf4168852007-02-28 20:11:53 -08004210 int max_degraded = (mddev->level == 5 ? 1 : 2);
NeilBrownf6705572006-03-27 01:18:11 -08004211
4212 if (mddev->new_level != mddev->level ||
4213 mddev->new_layout != mddev->layout ||
4214 mddev->new_chunk != mddev->chunk_size) {
NeilBrownf4168852007-02-28 20:11:53 -08004215 printk(KERN_ERR "raid5: %s: unsupported reshape "
4216 "required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004217 mdname(mddev));
4218 return -EINVAL;
4219 }
4220 if (mddev->delta_disks <= 0) {
NeilBrownf4168852007-02-28 20:11:53 -08004221 printk(KERN_ERR "raid5: %s: unsupported reshape "
4222 "(reduce disks) required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004223 mdname(mddev));
4224 return -EINVAL;
4225 }
4226 old_disks = mddev->raid_disks - mddev->delta_disks;
4227 /* reshape_position must be on a new-stripe boundary, and one
NeilBrownf4168852007-02-28 20:11:53 -08004228 * further up in new geometry must map after here in old
4229 * geometry.
NeilBrownf6705572006-03-27 01:18:11 -08004230 */
4231 here_new = mddev->reshape_position;
NeilBrownf4168852007-02-28 20:11:53 -08004232 if (sector_div(here_new, (mddev->chunk_size>>9)*
4233 (mddev->raid_disks - max_degraded))) {
4234 printk(KERN_ERR "raid5: reshape_position not "
4235 "on a stripe boundary\n");
NeilBrownf6705572006-03-27 01:18:11 -08004236 return -EINVAL;
4237 }
4238 /* here_new is the stripe we will write to */
4239 here_old = mddev->reshape_position;
NeilBrownf4168852007-02-28 20:11:53 -08004240 sector_div(here_old, (mddev->chunk_size>>9)*
4241 (old_disks-max_degraded));
4242 /* here_old is the first stripe that we might need to read
4243 * from */
NeilBrownf6705572006-03-27 01:18:11 -08004244 if (here_new >= here_old) {
4245 /* Reading from the same stripe as writing to - bad */
NeilBrownf4168852007-02-28 20:11:53 -08004246 printk(KERN_ERR "raid5: reshape_position too early for "
4247 "auto-recovery - aborting.\n");
NeilBrownf6705572006-03-27 01:18:11 -08004248 return -EINVAL;
4249 }
4250 printk(KERN_INFO "raid5: reshape will continue\n");
4251 /* OK, we should be able to continue; */
4252 }
4253
4254
NeilBrownb55e6bf2006-03-27 01:18:06 -08004255 mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004256 if ((conf = mddev->private) == NULL)
4257 goto abort;
NeilBrownf6705572006-03-27 01:18:11 -08004258 if (mddev->reshape_position == MaxSector) {
4259 conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
4260 } else {
4261 conf->raid_disks = mddev->raid_disks;
4262 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4263 }
4264
4265 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
NeilBrownb55e6bf2006-03-27 01:18:06 -08004266 GFP_KERNEL);
4267 if (!conf->disks)
4268 goto abort;
NeilBrown9ffae0c2006-01-06 00:20:32 -08004269
Linus Torvalds1da177e2005-04-16 15:20:36 -07004270 conf->mddev = mddev;
4271
NeilBrownfccddba2006-01-06 00:20:33 -08004272 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004273 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004274
NeilBrown16a53ec2006-06-26 00:27:38 -07004275 if (mddev->level == 6) {
4276 conf->spare_page = alloc_page(GFP_KERNEL);
4277 if (!conf->spare_page)
4278 goto abort;
4279 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004280 spin_lock_init(&conf->device_lock);
Neil Browne7e72bf2008-05-14 16:05:54 -07004281 mddev->queue->queue_lock = &conf->device_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004282 init_waitqueue_head(&conf->wait_for_stripe);
4283 init_waitqueue_head(&conf->wait_for_overlap);
4284 INIT_LIST_HEAD(&conf->handle_list);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004285 INIT_LIST_HEAD(&conf->hold_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004286 INIT_LIST_HEAD(&conf->delayed_list);
NeilBrown72626682005-09-09 16:23:54 -07004287 INIT_LIST_HEAD(&conf->bitmap_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004288 INIT_LIST_HEAD(&conf->inactive_list);
4289 atomic_set(&conf->active_stripes, 0);
4290 atomic_set(&conf->preread_active_stripes, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004291 atomic_set(&conf->active_aligned_reads, 0);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004292 conf->bypass_threshold = BYPASS_THRESHOLD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004293
Dan Williams45b42332007-07-09 11:56:43 -07004294 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004295
NeilBrownd089c6a2008-02-06 01:39:59 -08004296 rdev_for_each(rdev, tmp, mddev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004297 raid_disk = rdev->raid_disk;
NeilBrownf6705572006-03-27 01:18:11 -08004298 if (raid_disk >= conf->raid_disks
Linus Torvalds1da177e2005-04-16 15:20:36 -07004299 || raid_disk < 0)
4300 continue;
4301 disk = conf->disks + raid_disk;
4302
4303 disk->rdev = rdev;
4304
NeilBrownb2d444d2005-11-08 21:39:31 -08004305 if (test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004306 char b[BDEVNAME_SIZE];
4307 printk(KERN_INFO "raid5: device %s operational as raid"
4308 " disk %d\n", bdevname(rdev->bdev,b),
4309 raid_disk);
NeilBrown02c2de82006-10-03 01:15:47 -07004310 working_disks++;
Neil Brown8c2e8702008-06-28 08:30:52 +10004311 } else
4312 /* Cannot rely on bitmap to complete recovery */
4313 conf->fullsync = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004314 }
4315
Linus Torvalds1da177e2005-04-16 15:20:36 -07004316 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004317 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004318 */
NeilBrown02c2de82006-10-03 01:15:47 -07004319 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004320 conf->mddev = mddev;
4321 conf->chunk_size = mddev->chunk_size;
4322 conf->level = mddev->level;
NeilBrown16a53ec2006-06-26 00:27:38 -07004323 if (conf->level == 6)
4324 conf->max_degraded = 2;
4325 else
4326 conf->max_degraded = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004327 conf->algorithm = mddev->layout;
4328 conf->max_nr_stripes = NR_STRIPES;
NeilBrownf6705572006-03-27 01:18:11 -08004329 conf->expand_progress = mddev->reshape_position;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004330
4331 /* device size must be a multiple of chunk size */
4332 mddev->size &= ~(mddev->chunk_size/1024 -1);
NeilBrownb1581562005-07-31 22:34:50 -07004333 mddev->resync_max_sectors = mddev->size << 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004334
NeilBrown16a53ec2006-06-26 00:27:38 -07004335 if (conf->level == 6 && conf->raid_disks < 4) {
4336 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4337 mdname(mddev), conf->raid_disks);
4338 goto abort;
4339 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004340 if (!conf->chunk_size || conf->chunk_size % 4) {
4341 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
4342 conf->chunk_size, mdname(mddev));
4343 goto abort;
4344 }
4345 if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
4346 printk(KERN_ERR
4347 "raid5: unsupported parity algorithm %d for %s\n",
4348 conf->algorithm, mdname(mddev));
4349 goto abort;
4350 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004351 if (mddev->degraded > conf->max_degraded) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004352 printk(KERN_ERR "raid5: not enough operational devices for %s"
4353 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07004354 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004355 goto abort;
4356 }
4357
NeilBrown16a53ec2006-06-26 00:27:38 -07004358 if (mddev->degraded > 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07004359 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08004360 if (mddev->ok_start_degraded)
4361 printk(KERN_WARNING
4362 "raid5: starting dirty degraded array: %s"
4363 "- data corruption possible.\n",
4364 mdname(mddev));
4365 else {
4366 printk(KERN_ERR
4367 "raid5: cannot start dirty degraded array for %s\n",
4368 mdname(mddev));
4369 goto abort;
4370 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004371 }
4372
4373 {
4374 mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4375 if (!mddev->thread) {
4376 printk(KERN_ERR
4377 "raid5: couldn't allocate thread for %s\n",
4378 mdname(mddev));
4379 goto abort;
4380 }
4381 }
NeilBrown50368052005-12-12 02:39:17 -08004382 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07004383 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4384 if (grow_stripes(conf, conf->max_nr_stripes)) {
4385 printk(KERN_ERR
4386 "raid5: couldn't allocate %dkB for buffers\n", memory);
4387 shrink_stripes(conf);
4388 md_unregister_thread(mddev->thread);
4389 goto abort;
4390 } else
4391 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4392 memory, mdname(mddev));
4393
4394 if (mddev->degraded == 0)
4395 printk("raid5: raid level %d set %s active with %d out of %d"
4396 " devices, algorithm %d\n", conf->level, mdname(mddev),
4397 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4398 conf->algorithm);
4399 else
4400 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4401 " out of %d devices, algorithm %d\n", conf->level,
4402 mdname(mddev), mddev->raid_disks - mddev->degraded,
4403 mddev->raid_disks, conf->algorithm);
4404
4405 print_raid5_conf(conf);
4406
NeilBrownf6705572006-03-27 01:18:11 -08004407 if (conf->expand_progress != MaxSector) {
4408 printk("...ok start reshape thread\n");
NeilBrownb578d552006-03-27 01:18:12 -08004409 conf->expand_lo = conf->expand_progress;
NeilBrownf6705572006-03-27 01:18:11 -08004410 atomic_set(&conf->reshape_stripes, 0);
4411 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4412 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4413 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4414 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4415 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4416 "%s_reshape");
NeilBrownf6705572006-03-27 01:18:11 -08004417 }
4418
Linus Torvalds1da177e2005-04-16 15:20:36 -07004419 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07004420 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07004421 */
4422 {
NeilBrown16a53ec2006-06-26 00:27:38 -07004423 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4424 int stripe = data_disks *
NeilBrown8932c2e2006-06-26 00:27:36 -07004425 (mddev->chunk_size / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004426 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4427 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4428 }
4429
4430 /* Ok, everything is just fine now */
NeilBrown5e55e2f2007-03-26 21:32:14 -08004431 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4432 printk(KERN_WARNING
4433 "raid5: failed to create sysfs attributes for %s\n",
4434 mdname(mddev));
NeilBrown7a5febe2005-05-16 21:53:16 -07004435
4436 mddev->queue->unplug_fn = raid5_unplug_device;
NeilBrownf022b2f2006-10-03 01:15:56 -07004437 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown041ae522007-03-26 21:32:14 -08004438 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
NeilBrownf022b2f2006-10-03 01:15:56 -07004439
NeilBrown16a53ec2006-06-26 00:27:38 -07004440 mddev->array_size = mddev->size * (conf->previous_raid_disks -
4441 conf->max_degraded);
NeilBrown7a5febe2005-05-16 21:53:16 -07004442
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08004443 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
4444
Linus Torvalds1da177e2005-04-16 15:20:36 -07004445 return 0;
4446abort:
4447 if (conf) {
4448 print_raid5_conf(conf);
NeilBrown16a53ec2006-06-26 00:27:38 -07004449 safe_put_page(conf->spare_page);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004450 kfree(conf->disks);
NeilBrownfccddba2006-01-06 00:20:33 -08004451 kfree(conf->stripe_hashtbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004452 kfree(conf);
4453 }
4454 mddev->private = NULL;
4455 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4456 return -EIO;
4457}
4458
4459
4460
NeilBrown3f294f42005-11-08 21:39:25 -08004461static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004462{
4463 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4464
4465 md_unregister_thread(mddev->thread);
4466 mddev->thread = NULL;
4467 shrink_stripes(conf);
NeilBrownfccddba2006-01-06 00:20:33 -08004468 kfree(conf->stripe_hashtbl);
NeilBrown041ae522007-03-26 21:32:14 -08004469 mddev->queue->backing_dev_info.congested_fn = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004470 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
NeilBrown007583c2005-11-08 21:39:30 -08004471 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
NeilBrownb55e6bf2006-03-27 01:18:06 -08004472 kfree(conf->disks);
NeilBrown96de1e62005-11-08 21:39:39 -08004473 kfree(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004474 mddev->private = NULL;
4475 return 0;
4476}
4477
Dan Williams45b42332007-07-09 11:56:43 -07004478#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004479static void print_sh (struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004480{
4481 int i;
4482
NeilBrown16a53ec2006-06-26 00:27:38 -07004483 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4484 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4485 seq_printf(seq, "sh %llu, count %d.\n",
4486 (unsigned long long)sh->sector, atomic_read(&sh->count));
4487 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08004488 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07004489 seq_printf(seq, "(cache%d: %p %ld) ",
4490 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004491 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004492 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004493}
4494
NeilBrown16a53ec2006-06-26 00:27:38 -07004495static void printall (struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004496{
4497 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08004498 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004499 int i;
4500
4501 spin_lock_irq(&conf->device_lock);
4502 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08004503 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004504 if (sh->raid_conf != conf)
4505 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07004506 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004507 }
4508 }
4509 spin_unlock_irq(&conf->device_lock);
4510}
4511#endif
4512
4513static void status (struct seq_file *seq, mddev_t *mddev)
4514{
4515 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4516 int i;
4517
4518 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07004519 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004520 for (i = 0; i < conf->raid_disks; i++)
4521 seq_printf (seq, "%s",
4522 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08004523 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004524 seq_printf (seq, "]");
Dan Williams45b42332007-07-09 11:56:43 -07004525#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07004526 seq_printf (seq, "\n");
4527 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004528#endif
4529}
4530
4531static void print_raid5_conf (raid5_conf_t *conf)
4532{
4533 int i;
4534 struct disk_info *tmp;
4535
4536 printk("RAID5 conf printout:\n");
4537 if (!conf) {
4538 printk("(conf==NULL)\n");
4539 return;
4540 }
NeilBrown02c2de82006-10-03 01:15:47 -07004541 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4542 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004543
4544 for (i = 0; i < conf->raid_disks; i++) {
4545 char b[BDEVNAME_SIZE];
4546 tmp = conf->disks + i;
4547 if (tmp->rdev)
4548 printk(" disk %d, o:%d, dev:%s\n",
NeilBrownb2d444d2005-11-08 21:39:31 -08004549 i, !test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -07004550 bdevname(tmp->rdev->bdev,b));
4551 }
4552}
4553
4554static int raid5_spare_active(mddev_t *mddev)
4555{
4556 int i;
4557 raid5_conf_t *conf = mddev->private;
4558 struct disk_info *tmp;
4559
4560 for (i = 0; i < conf->raid_disks; i++) {
4561 tmp = conf->disks + i;
4562 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08004563 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07004564 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4565 unsigned long flags;
4566 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004567 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07004568 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004569 }
4570 }
4571 print_raid5_conf(conf);
4572 return 0;
4573}
4574
4575static int raid5_remove_disk(mddev_t *mddev, int number)
4576{
4577 raid5_conf_t *conf = mddev->private;
4578 int err = 0;
4579 mdk_rdev_t *rdev;
4580 struct disk_info *p = conf->disks + number;
4581
4582 print_raid5_conf(conf);
4583 rdev = p->rdev;
4584 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004585 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07004586 atomic_read(&rdev->nr_pending)) {
4587 err = -EBUSY;
4588 goto abort;
4589 }
NeilBrowndfc70642008-05-23 13:04:39 -07004590 /* Only remove non-faulty devices if recovery
4591 * isn't possible.
4592 */
4593 if (!test_bit(Faulty, &rdev->flags) &&
4594 mddev->degraded <= conf->max_degraded) {
4595 err = -EBUSY;
4596 goto abort;
4597 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004598 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07004599 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004600 if (atomic_read(&rdev->nr_pending)) {
4601 /* lost the race, try later */
4602 err = -EBUSY;
4603 p->rdev = rdev;
4604 }
4605 }
4606abort:
4607
4608 print_raid5_conf(conf);
4609 return err;
4610}
4611
4612static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4613{
4614 raid5_conf_t *conf = mddev->private;
4615 int found = 0;
4616 int disk;
4617 struct disk_info *p;
4618
NeilBrown16a53ec2006-06-26 00:27:38 -07004619 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004620 /* no point adding a device */
4621 return 0;
4622
4623 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004624 * find the disk ... but prefer rdev->saved_raid_disk
4625 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004626 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004627 if (rdev->saved_raid_disk >= 0 &&
4628 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4629 disk = rdev->saved_raid_disk;
4630 else
4631 disk = 0;
4632 for ( ; disk < conf->raid_disks; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004633 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08004634 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004635 rdev->raid_disk = disk;
4636 found = 1;
NeilBrown72626682005-09-09 16:23:54 -07004637 if (rdev->saved_raid_disk != disk)
4638 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08004639 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004640 break;
4641 }
4642 print_raid5_conf(conf);
4643 return found;
4644}
4645
4646static int raid5_resize(mddev_t *mddev, sector_t sectors)
4647{
4648 /* no resync is happening, and there is enough space
4649 * on all devices, so we can resize.
4650 * We need to make sure resync covers any new space.
4651 * If the array is shrinking we should possibly wait until
4652 * any io in the removed space completes, but it hardly seems
4653 * worth it.
4654 */
NeilBrown16a53ec2006-06-26 00:27:38 -07004655 raid5_conf_t *conf = mddev_to_conf(mddev);
4656
Linus Torvalds1da177e2005-04-16 15:20:36 -07004657 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07004658 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004659 set_capacity(mddev->gendisk, mddev->array_size << 1);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004660 mddev->changed = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004661 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
4662 mddev->recovery_cp = mddev->size << 1;
4663 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4664 }
4665 mddev->size = sectors /2;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07004666 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004667 return 0;
4668}
4669
NeilBrown29269552006-03-27 01:18:10 -08004670#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08004671static int raid5_check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08004672{
4673 raid5_conf_t *conf = mddev_to_conf(mddev);
4674 int err;
NeilBrown29269552006-03-27 01:18:10 -08004675
NeilBrown63c70c42006-03-27 01:18:13 -08004676 if (mddev->delta_disks < 0 ||
4677 mddev->new_level != mddev->level)
4678 return -EINVAL; /* Cannot shrink array or change level yet */
4679 if (mddev->delta_disks == 0)
NeilBrown29269552006-03-27 01:18:10 -08004680 return 0; /* nothing to do */
4681
4682 /* Can only proceed if there are plenty of stripe_heads.
4683 * We need a minimum of one full stripe,, and for sensible progress
4684 * it is best to have about 4 times that.
4685 * If we require 4 times, then the default 256 4K stripe_heads will
4686 * allow for chunk sizes up to 256K, which is probably OK.
4687 * If the chunk size is greater, user-space should request more
4688 * stripe_heads first.
4689 */
NeilBrown63c70c42006-03-27 01:18:13 -08004690 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
4691 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
NeilBrown29269552006-03-27 01:18:10 -08004692 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
4693 (mddev->chunk_size / STRIPE_SIZE)*4);
4694 return -ENOSPC;
4695 }
4696
NeilBrown63c70c42006-03-27 01:18:13 -08004697 err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
4698 if (err)
4699 return err;
4700
NeilBrownb4c4c7b2007-02-28 20:11:48 -08004701 if (mddev->degraded > conf->max_degraded)
4702 return -EINVAL;
NeilBrown63c70c42006-03-27 01:18:13 -08004703 /* looks like we might be able to manage this */
4704 return 0;
4705}
4706
4707static int raid5_start_reshape(mddev_t *mddev)
4708{
4709 raid5_conf_t *conf = mddev_to_conf(mddev);
4710 mdk_rdev_t *rdev;
4711 struct list_head *rtmp;
4712 int spares = 0;
4713 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07004714 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08004715
NeilBrownf4168852007-02-28 20:11:53 -08004716 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
NeilBrown63c70c42006-03-27 01:18:13 -08004717 return -EBUSY;
4718
NeilBrownd089c6a2008-02-06 01:39:59 -08004719 rdev_for_each(rdev, rtmp, mddev)
NeilBrown29269552006-03-27 01:18:10 -08004720 if (rdev->raid_disk < 0 &&
4721 !test_bit(Faulty, &rdev->flags))
4722 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08004723
NeilBrownf4168852007-02-28 20:11:53 -08004724 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
NeilBrown29269552006-03-27 01:18:10 -08004725 /* Not enough devices even to make a degraded array
4726 * of that size
4727 */
4728 return -EINVAL;
4729
NeilBrownf6705572006-03-27 01:18:11 -08004730 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08004731 spin_lock_irq(&conf->device_lock);
4732 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08004733 conf->raid_disks += mddev->delta_disks;
NeilBrown29269552006-03-27 01:18:10 -08004734 conf->expand_progress = 0;
NeilBrownb578d552006-03-27 01:18:12 -08004735 conf->expand_lo = 0;
NeilBrown29269552006-03-27 01:18:10 -08004736 spin_unlock_irq(&conf->device_lock);
4737
4738 /* Add some new drives, as many as will fit.
4739 * We know there are enough to make the newly sized array work.
4740 */
NeilBrownd089c6a2008-02-06 01:39:59 -08004741 rdev_for_each(rdev, rtmp, mddev)
NeilBrown29269552006-03-27 01:18:10 -08004742 if (rdev->raid_disk < 0 &&
4743 !test_bit(Faulty, &rdev->flags)) {
4744 if (raid5_add_disk(mddev, rdev)) {
4745 char nm[20];
4746 set_bit(In_sync, &rdev->flags);
NeilBrown29269552006-03-27 01:18:10 -08004747 added_devices++;
NeilBrown5fd6c1d2006-06-26 00:27:40 -07004748 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08004749 sprintf(nm, "rd%d", rdev->raid_disk);
NeilBrown5e55e2f2007-03-26 21:32:14 -08004750 if (sysfs_create_link(&mddev->kobj,
4751 &rdev->kobj, nm))
4752 printk(KERN_WARNING
4753 "raid5: failed to create "
4754 " link %s for %s\n",
4755 nm, mdname(mddev));
NeilBrown29269552006-03-27 01:18:10 -08004756 } else
4757 break;
4758 }
4759
NeilBrownc04be0a2006-10-03 01:15:53 -07004760 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08004761 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
NeilBrownc04be0a2006-10-03 01:15:53 -07004762 spin_unlock_irqrestore(&conf->device_lock, flags);
NeilBrown63c70c42006-03-27 01:18:13 -08004763 mddev->raid_disks = conf->raid_disks;
NeilBrownf6705572006-03-27 01:18:11 -08004764 mddev->reshape_position = 0;
NeilBrown850b2b42006-10-03 01:15:46 -07004765 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08004766
NeilBrown29269552006-03-27 01:18:10 -08004767 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4768 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4769 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4770 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4771 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4772 "%s_reshape");
4773 if (!mddev->sync_thread) {
4774 mddev->recovery = 0;
4775 spin_lock_irq(&conf->device_lock);
4776 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
4777 conf->expand_progress = MaxSector;
4778 spin_unlock_irq(&conf->device_lock);
4779 return -EAGAIN;
4780 }
4781 md_wakeup_thread(mddev->sync_thread);
4782 md_new_event(mddev);
4783 return 0;
4784}
4785#endif
4786
4787static void end_reshape(raid5_conf_t *conf)
4788{
4789 struct block_device *bdev;
4790
NeilBrownf6705572006-03-27 01:18:11 -08004791 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
NeilBrownf4168852007-02-28 20:11:53 -08004792 conf->mddev->array_size = conf->mddev->size *
4793 (conf->raid_disks - conf->max_degraded);
NeilBrownf6705572006-03-27 01:18:11 -08004794 set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
Linus Torvalds44ce62942007-05-09 18:51:36 -07004795 conf->mddev->changed = 1;
NeilBrown29269552006-03-27 01:18:10 -08004796
NeilBrownf6705572006-03-27 01:18:11 -08004797 bdev = bdget_disk(conf->mddev->gendisk, 0);
4798 if (bdev) {
4799 mutex_lock(&bdev->bd_inode->i_mutex);
NeilBrown0692c6b2006-11-08 17:44:48 -08004800 i_size_write(bdev->bd_inode, (loff_t)conf->mddev->array_size << 10);
NeilBrownf6705572006-03-27 01:18:11 -08004801 mutex_unlock(&bdev->bd_inode->i_mutex);
4802 bdput(bdev);
4803 }
4804 spin_lock_irq(&conf->device_lock);
4805 conf->expand_progress = MaxSector;
4806 spin_unlock_irq(&conf->device_lock);
4807 conf->mddev->reshape_position = MaxSector;
NeilBrown16a53ec2006-06-26 00:27:38 -07004808
4809 /* read-ahead size must cover two whole stripes, which is
4810 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4811 */
4812 {
4813 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4814 int stripe = data_disks *
4815 (conf->mddev->chunk_size / PAGE_SIZE);
4816 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4817 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4818 }
NeilBrown29269552006-03-27 01:18:10 -08004819 }
NeilBrown29269552006-03-27 01:18:10 -08004820}
4821
NeilBrown72626682005-09-09 16:23:54 -07004822static void raid5_quiesce(mddev_t *mddev, int state)
4823{
4824 raid5_conf_t *conf = mddev_to_conf(mddev);
4825
4826 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08004827 case 2: /* resume for a suspend */
4828 wake_up(&conf->wait_for_overlap);
4829 break;
4830
NeilBrown72626682005-09-09 16:23:54 -07004831 case 1: /* stop all writes */
4832 spin_lock_irq(&conf->device_lock);
4833 conf->quiesce = 1;
4834 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004835 atomic_read(&conf->active_stripes) == 0 &&
4836 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07004837 conf->device_lock, /* nothing */);
4838 spin_unlock_irq(&conf->device_lock);
4839 break;
4840
4841 case 0: /* re-enable writes */
4842 spin_lock_irq(&conf->device_lock);
4843 conf->quiesce = 0;
4844 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08004845 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07004846 spin_unlock_irq(&conf->device_lock);
4847 break;
4848 }
NeilBrown72626682005-09-09 16:23:54 -07004849}
NeilBrownb15c2e52006-01-06 00:20:16 -08004850
NeilBrown16a53ec2006-06-26 00:27:38 -07004851static struct mdk_personality raid6_personality =
4852{
4853 .name = "raid6",
4854 .level = 6,
4855 .owner = THIS_MODULE,
4856 .make_request = make_request,
4857 .run = run,
4858 .stop = stop,
4859 .status = status,
4860 .error_handler = error,
4861 .hot_add_disk = raid5_add_disk,
4862 .hot_remove_disk= raid5_remove_disk,
4863 .spare_active = raid5_spare_active,
4864 .sync_request = sync_request,
4865 .resize = raid5_resize,
NeilBrownf4168852007-02-28 20:11:53 -08004866#ifdef CONFIG_MD_RAID5_RESHAPE
4867 .check_reshape = raid5_check_reshape,
4868 .start_reshape = raid5_start_reshape,
4869#endif
NeilBrown16a53ec2006-06-26 00:27:38 -07004870 .quiesce = raid5_quiesce,
4871};
NeilBrown2604b702006-01-06 00:20:36 -08004872static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07004873{
4874 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08004875 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004876 .owner = THIS_MODULE,
4877 .make_request = make_request,
4878 .run = run,
4879 .stop = stop,
4880 .status = status,
4881 .error_handler = error,
4882 .hot_add_disk = raid5_add_disk,
4883 .hot_remove_disk= raid5_remove_disk,
4884 .spare_active = raid5_spare_active,
4885 .sync_request = sync_request,
4886 .resize = raid5_resize,
NeilBrown29269552006-03-27 01:18:10 -08004887#ifdef CONFIG_MD_RAID5_RESHAPE
NeilBrown63c70c42006-03-27 01:18:13 -08004888 .check_reshape = raid5_check_reshape,
4889 .start_reshape = raid5_start_reshape,
NeilBrown29269552006-03-27 01:18:10 -08004890#endif
NeilBrown72626682005-09-09 16:23:54 -07004891 .quiesce = raid5_quiesce,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004892};
4893
NeilBrown2604b702006-01-06 00:20:36 -08004894static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07004895{
NeilBrown2604b702006-01-06 00:20:36 -08004896 .name = "raid4",
4897 .level = 4,
4898 .owner = THIS_MODULE,
4899 .make_request = make_request,
4900 .run = run,
4901 .stop = stop,
4902 .status = status,
4903 .error_handler = error,
4904 .hot_add_disk = raid5_add_disk,
4905 .hot_remove_disk= raid5_remove_disk,
4906 .spare_active = raid5_spare_active,
4907 .sync_request = sync_request,
4908 .resize = raid5_resize,
NeilBrown3d378902007-03-26 21:32:13 -08004909#ifdef CONFIG_MD_RAID5_RESHAPE
4910 .check_reshape = raid5_check_reshape,
4911 .start_reshape = raid5_start_reshape,
4912#endif
NeilBrown2604b702006-01-06 00:20:36 -08004913 .quiesce = raid5_quiesce,
4914};
4915
4916static int __init raid5_init(void)
4917{
NeilBrown16a53ec2006-06-26 00:27:38 -07004918 int e;
4919
4920 e = raid6_select_algo();
4921 if ( e )
4922 return e;
4923 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08004924 register_md_personality(&raid5_personality);
4925 register_md_personality(&raid4_personality);
4926 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004927}
4928
NeilBrown2604b702006-01-06 00:20:36 -08004929static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004930{
NeilBrown16a53ec2006-06-26 00:27:38 -07004931 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08004932 unregister_md_personality(&raid5_personality);
4933 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004934}
4935
4936module_init(raid5_init);
4937module_exit(raid5_exit);
4938MODULE_LICENSE("GPL");
4939MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08004940MODULE_ALIAS("md-raid5");
4941MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08004942MODULE_ALIAS("md-level-5");
4943MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07004944MODULE_ALIAS("md-personality-8"); /* RAID6 */
4945MODULE_ALIAS("md-raid6");
4946MODULE_ALIAS("md-level-6");
4947
4948/* This used to be two separate modules, they were: */
4949MODULE_ALIAS("raid5");
4950MODULE_ALIAS("raid6");