blob: d2c0f94fa37d7a708b1c6854e7be3b1d3b60162f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
NeilBrown16a53ec2006-06-26 00:27:38 -07005 * Copyright (C) 2002, 2003 H. Peter Anvin
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
NeilBrown16a53ec2006-06-26 00:27:38 -07007 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
NeilBrownae3c20c2006-07-10 04:44:17 -070021/*
22 * BITMAP UNPLUGGING:
23 *
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
26 * explanation.
27 *
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->bm_write is the number of the last batch successfully written.
31 * conf->bm_flush is the number of the last batch that was closed to
32 * new additions.
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is bm_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
39 * batch.
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
43 * miss any bits.
44 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
NeilBrownbff61972009-03-31 14:33:13 +110046#include <linux/blkdev.h>
NeilBrownf6705572006-03-27 01:18:11 -080047#include <linux/kthread.h>
Dan Williamsf701d582009-03-31 15:09:39 +110048#include <linux/raid/pq.h>
Dan Williams91c00922007-01-02 13:52:30 -070049#include <linux/async_tx.h>
Dan Williams07a3b412009-08-29 19:13:13 -070050#include <linux/async.h>
NeilBrownbff61972009-03-31 14:33:13 +110051#include <linux/seq_file.h>
Dan Williams36d1c642009-07-14 11:48:22 -070052#include <linux/cpu.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090053#include <linux/slab.h>
NeilBrown43b2e5d2009-03-31 14:33:13 +110054#include "md.h"
NeilBrownbff61972009-03-31 14:33:13 +110055#include "raid5.h"
Trela Maciej54071b32010-03-08 16:02:42 +110056#include "raid0.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110057#include "bitmap.h"
NeilBrown72626682005-09-09 16:23:54 -070058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/*
60 * Stripe cache
61 */
62
63#define NR_STRIPES 256
64#define STRIPE_SIZE PAGE_SIZE
65#define STRIPE_SHIFT (PAGE_SHIFT - 9)
66#define STRIPE_SECTORS (STRIPE_SIZE>>9)
67#define IO_THRESHOLD 1
Dan Williams8b3e6cd2008-04-28 02:15:53 -070068#define BYPASS_THRESHOLD 1
NeilBrownfccddba2006-01-06 00:20:33 -080069#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#define HASH_MASK (NR_HASH - 1)
71
NeilBrownfccddba2006-01-06 00:20:33 -080072#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74/* bio's attached to a stripe+device for I/O are linked together in bi_sector
75 * order without overlap. There may be several bio's per stripe+device, and
76 * a bio could span several devices.
77 * When walking this list for a particular stripe+device, we must never proceed
78 * beyond a bio that extends past this device, as the next bio might no longer
79 * be valid.
80 * This macro is used to determine the 'next' bio in the list, given the sector
81 * of the current stripe+device
82 */
83#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
84/*
85 * The following can be used to debug the driver
86 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#define RAID5_PARANOIA 1
88#if RAID5_PARANOIA && defined(CONFIG_SMP)
89# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
90#else
91# define CHECK_DEVLOCK()
92#endif
93
Dan Williams45b42332007-07-09 11:56:43 -070094#ifdef DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070095#define inline
96#define __inline__
97#endif
98
Bernd Schubert6be9d492008-05-23 13:04:34 -070099#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
100
Jens Axboe960e7392008-08-15 10:41:18 +0200101/*
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200102 * We maintain a biased count of active stripes in the bottom 16 bits of
103 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
Jens Axboe960e7392008-08-15 10:41:18 +0200104 */
105static inline int raid5_bi_phys_segments(struct bio *bio)
106{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200107 return bio->bi_phys_segments & 0xffff;
Jens Axboe960e7392008-08-15 10:41:18 +0200108}
109
110static inline int raid5_bi_hw_segments(struct bio *bio)
111{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200112 return (bio->bi_phys_segments >> 16) & 0xffff;
Jens Axboe960e7392008-08-15 10:41:18 +0200113}
114
115static inline int raid5_dec_bi_phys_segments(struct bio *bio)
116{
117 --bio->bi_phys_segments;
118 return raid5_bi_phys_segments(bio);
119}
120
121static inline int raid5_dec_bi_hw_segments(struct bio *bio)
122{
123 unsigned short val = raid5_bi_hw_segments(bio);
124
125 --val;
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200126 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
Jens Axboe960e7392008-08-15 10:41:18 +0200127 return val;
128}
129
130static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
131{
Jens Axboe5b99c2f2008-08-15 10:56:11 +0200132 bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
Jens Axboe960e7392008-08-15 10:41:18 +0200133}
134
NeilBrownd0dabf72009-03-31 14:39:38 +1100135/* Find first data disk in a raid6 stripe */
136static inline int raid6_d0(struct stripe_head *sh)
137{
NeilBrown67cc2b82009-03-31 14:39:38 +1100138 if (sh->ddf_layout)
139 /* ddf always start from first device */
140 return 0;
141 /* md starts just after Q block */
NeilBrownd0dabf72009-03-31 14:39:38 +1100142 if (sh->qd_idx == sh->disks - 1)
143 return 0;
144 else
145 return sh->qd_idx + 1;
146}
NeilBrown16a53ec2006-06-26 00:27:38 -0700147static inline int raid6_next_disk(int disk, int raid_disks)
148{
149 disk++;
150 return (disk < raid_disks) ? disk : 0;
151}
Dan Williamsa4456852007-07-09 11:56:43 -0700152
NeilBrownd0dabf72009-03-31 14:39:38 +1100153/* When walking through the disks in a raid5, starting at raid6_d0,
154 * We need to map each disk to a 'slot', where the data disks are slot
155 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
156 * is raid_disks-1. This help does that mapping.
157 */
NeilBrown67cc2b82009-03-31 14:39:38 +1100158static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
159 int *count, int syndrome_disks)
NeilBrownd0dabf72009-03-31 14:39:38 +1100160{
Dan Williams66295422009-10-19 18:09:32 -0700161 int slot = *count;
NeilBrown67cc2b82009-03-31 14:39:38 +1100162
NeilBrowne4424fe2009-10-16 16:27:34 +1100163 if (sh->ddf_layout)
Dan Williams66295422009-10-19 18:09:32 -0700164 (*count)++;
NeilBrownd0dabf72009-03-31 14:39:38 +1100165 if (idx == sh->pd_idx)
NeilBrown67cc2b82009-03-31 14:39:38 +1100166 return syndrome_disks;
NeilBrownd0dabf72009-03-31 14:39:38 +1100167 if (idx == sh->qd_idx)
NeilBrown67cc2b82009-03-31 14:39:38 +1100168 return syndrome_disks + 1;
NeilBrowne4424fe2009-10-16 16:27:34 +1100169 if (!sh->ddf_layout)
Dan Williams66295422009-10-19 18:09:32 -0700170 (*count)++;
NeilBrownd0dabf72009-03-31 14:39:38 +1100171 return slot;
172}
173
Dan Williamsa4456852007-07-09 11:56:43 -0700174static void return_io(struct bio *return_bi)
175{
176 struct bio *bi = return_bi;
177 while (bi) {
Dan Williamsa4456852007-07-09 11:56:43 -0700178
179 return_bi = bi->bi_next;
180 bi->bi_next = NULL;
181 bi->bi_size = 0;
Neil Brown0e13fe232008-06-28 08:31:20 +1000182 bio_endio(bi, 0);
Dan Williamsa4456852007-07-09 11:56:43 -0700183 bi = return_bi;
184 }
185}
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187static void print_raid5_conf (raid5_conf_t *conf);
188
Dan Williams600aa102008-06-28 08:32:05 +1000189static int stripe_operations_active(struct stripe_head *sh)
190{
191 return sh->check_state || sh->reconstruct_state ||
192 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
193 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
194}
195
Arjan van de Ven858119e2006-01-14 13:20:43 -0800196static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197{
198 if (atomic_dec_and_test(&sh->count)) {
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200199 BUG_ON(!list_empty(&sh->lru));
200 BUG_ON(atomic_read(&conf->active_stripes)==0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 if (test_bit(STRIPE_HANDLE, &sh->state)) {
NeilBrown7c785b72006-07-10 04:44:16 -0700202 if (test_bit(STRIPE_DELAYED, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 list_add_tail(&sh->lru, &conf->delayed_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700204 blk_plug_device(conf->mddev->queue);
205 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
NeilBrownae3c20c2006-07-10 04:44:17 -0700206 sh->bm_seq - conf->seq_write > 0) {
NeilBrown72626682005-09-09 16:23:54 -0700207 list_add_tail(&sh->lru, &conf->bitmap_list);
NeilBrown7c785b72006-07-10 04:44:16 -0700208 blk_plug_device(conf->mddev->queue);
209 } else {
NeilBrown72626682005-09-09 16:23:54 -0700210 clear_bit(STRIPE_BIT_DELAY, &sh->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 list_add_tail(&sh->lru, &conf->handle_list);
NeilBrown72626682005-09-09 16:23:54 -0700212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 md_wakeup_thread(conf->mddev->thread);
214 } else {
Dan Williams600aa102008-06-28 08:32:05 +1000215 BUG_ON(stripe_operations_active(sh));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
217 atomic_dec(&conf->preread_active_stripes);
218 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
219 md_wakeup_thread(conf->mddev->thread);
220 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 atomic_dec(&conf->active_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800222 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
223 list_add_tail(&sh->lru, &conf->inactive_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 wake_up(&conf->wait_for_stripe);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -0800225 if (conf->retry_read_aligned)
226 md_wakeup_thread(conf->mddev->thread);
NeilBrownccfcc3c2006-03-27 01:18:09 -0800227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 }
229 }
230}
NeilBrownd0dabf72009-03-31 14:39:38 +1100231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232static void release_stripe(struct stripe_head *sh)
233{
234 raid5_conf_t *conf = sh->raid_conf;
235 unsigned long flags;
NeilBrown16a53ec2006-06-26 00:27:38 -0700236
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 spin_lock_irqsave(&conf->device_lock, flags);
238 __release_stripe(conf, sh);
239 spin_unlock_irqrestore(&conf->device_lock, flags);
240}
241
NeilBrownfccddba2006-01-06 00:20:33 -0800242static inline void remove_hash(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
Dan Williams45b42332007-07-09 11:56:43 -0700244 pr_debug("remove_hash(), stripe %llu\n",
245 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
NeilBrownfccddba2006-01-06 00:20:33 -0800247 hlist_del_init(&sh->hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248}
249
NeilBrown16a53ec2006-06-26 00:27:38 -0700250static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251{
NeilBrownfccddba2006-01-06 00:20:33 -0800252 struct hlist_head *hp = stripe_hash(conf, sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Dan Williams45b42332007-07-09 11:56:43 -0700254 pr_debug("insert_hash(), stripe %llu\n",
255 (unsigned long long)sh->sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257 CHECK_DEVLOCK();
NeilBrownfccddba2006-01-06 00:20:33 -0800258 hlist_add_head(&sh->hash, hp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
261
262/* find an idle stripe, make sure it is unhashed, and return it. */
263static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
264{
265 struct stripe_head *sh = NULL;
266 struct list_head *first;
267
268 CHECK_DEVLOCK();
269 if (list_empty(&conf->inactive_list))
270 goto out;
271 first = conf->inactive_list.next;
272 sh = list_entry(first, struct stripe_head, lru);
273 list_del_init(first);
274 remove_hash(sh);
275 atomic_inc(&conf->active_stripes);
276out:
277 return sh;
278}
279
280static void shrink_buffers(struct stripe_head *sh, int num)
281{
282 struct page *p;
283 int i;
284
285 for (i=0; i<num ; i++) {
286 p = sh->dev[i].page;
287 if (!p)
288 continue;
289 sh->dev[i].page = NULL;
NeilBrown2d1f3b52006-01-06 00:20:31 -0800290 put_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 }
292}
293
294static int grow_buffers(struct stripe_head *sh, int num)
295{
296 int i;
297
298 for (i=0; i<num; i++) {
299 struct page *page;
300
301 if (!(page = alloc_page(GFP_KERNEL))) {
302 return 1;
303 }
304 sh->dev[i].page = page;
305 }
306 return 0;
307}
308
NeilBrown784052e2009-03-31 15:19:07 +1100309static void raid5_build_block(struct stripe_head *sh, int i, int previous);
NeilBrown911d4ee2009-03-31 14:39:38 +1100310static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
311 struct stripe_head *sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
NeilBrownb5663ba2009-03-31 14:39:38 +1100313static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
315 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800316 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +0200318 BUG_ON(atomic_read(&sh->count) != 0);
319 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
Dan Williams600aa102008-06-28 08:32:05 +1000320 BUG_ON(stripe_operations_active(sh));
Dan Williamsd84e0f12007-01-02 13:52:30 -0700321
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700323 pr_debug("init_stripe called, stripe %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 (unsigned long long)sh->sector);
325
326 remove_hash(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -0700327
NeilBrown86b42c72009-03-31 15:19:03 +1100328 sh->generation = conf->generation - previous;
NeilBrownb5663ba2009-03-31 14:39:38 +1100329 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 sh->sector = sector;
NeilBrown911d4ee2009-03-31 14:39:38 +1100331 stripe_set_idx(sector, conf, previous, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 sh->state = 0;
333
NeilBrown7ecaa1e2006-03-27 01:18:08 -0800334
335 for (i = sh->disks; i--; ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 struct r5dev *dev = &sh->dev[i];
337
Dan Williamsd84e0f12007-01-02 13:52:30 -0700338 if (dev->toread || dev->read || dev->towrite || dev->written ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 test_bit(R5_LOCKED, &dev->flags)) {
Dan Williamsd84e0f12007-01-02 13:52:30 -0700340 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 (unsigned long long)sh->sector, i, dev->toread,
Dan Williamsd84e0f12007-01-02 13:52:30 -0700342 dev->read, dev->towrite, dev->written,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 test_bit(R5_LOCKED, &dev->flags));
344 BUG();
345 }
346 dev->flags = 0;
NeilBrown784052e2009-03-31 15:19:07 +1100347 raid5_build_block(sh, i, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 }
349 insert_hash(conf, sh);
350}
351
NeilBrown86b42c72009-03-31 15:19:03 +1100352static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
353 short generation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354{
355 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -0800356 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
358 CHECK_DEVLOCK();
Dan Williams45b42332007-07-09 11:56:43 -0700359 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
NeilBrownfccddba2006-01-06 00:20:33 -0800360 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
NeilBrown86b42c72009-03-31 15:19:03 +1100361 if (sh->sector == sector && sh->generation == generation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 return sh;
Dan Williams45b42332007-07-09 11:56:43 -0700363 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 return NULL;
365}
366
367static void unplug_slaves(mddev_t *mddev);
Jens Axboe165125e2007-07-24 09:28:11 +0200368static void raid5_unplug_device(struct request_queue *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
NeilBrownb5663ba2009-03-31 14:39:38 +1100370static struct stripe_head *
371get_active_stripe(raid5_conf_t *conf, sector_t sector,
NeilBrowna8c906c2009-06-09 14:39:59 +1000372 int previous, int noblock, int noquiesce)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373{
374 struct stripe_head *sh;
375
Dan Williams45b42332007-07-09 11:56:43 -0700376 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
378 spin_lock_irq(&conf->device_lock);
379
380 do {
NeilBrown72626682005-09-09 16:23:54 -0700381 wait_event_lock_irq(conf->wait_for_stripe,
NeilBrowna8c906c2009-06-09 14:39:59 +1000382 conf->quiesce == 0 || noquiesce,
NeilBrown72626682005-09-09 16:23:54 -0700383 conf->device_lock, /* nothing */);
NeilBrown86b42c72009-03-31 15:19:03 +1100384 sh = __find_stripe(conf, sector, conf->generation - previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 if (!sh) {
386 if (!conf->inactive_blocked)
387 sh = get_free_stripe(conf);
388 if (noblock && sh == NULL)
389 break;
390 if (!sh) {
391 conf->inactive_blocked = 1;
392 wait_event_lock_irq(conf->wait_for_stripe,
393 !list_empty(&conf->inactive_list) &&
NeilBrown50368052005-12-12 02:39:17 -0800394 (atomic_read(&conf->active_stripes)
395 < (conf->max_nr_stripes *3/4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 || !conf->inactive_blocked),
397 conf->device_lock,
NeilBrownf4370782006-07-10 04:44:14 -0700398 raid5_unplug_device(conf->mddev->queue)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 );
400 conf->inactive_blocked = 0;
401 } else
NeilBrownb5663ba2009-03-31 14:39:38 +1100402 init_stripe(sh, sector, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 } else {
404 if (atomic_read(&sh->count)) {
NeilBrownab69ae12009-03-31 15:26:47 +1100405 BUG_ON(!list_empty(&sh->lru)
406 && !test_bit(STRIPE_EXPANDING, &sh->state));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 } else {
408 if (!test_bit(STRIPE_HANDLE, &sh->state))
409 atomic_inc(&conf->active_stripes);
NeilBrownff4e8d92006-07-10 04:44:16 -0700410 if (list_empty(&sh->lru) &&
411 !test_bit(STRIPE_EXPANDING, &sh->state))
NeilBrown16a53ec2006-06-26 00:27:38 -0700412 BUG();
413 list_del_init(&sh->lru);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 }
415 }
416 } while (sh == NULL);
417
418 if (sh)
419 atomic_inc(&sh->count);
420
421 spin_unlock_irq(&conf->device_lock);
422 return sh;
423}
424
NeilBrown6712ecf2007-09-27 12:47:43 +0200425static void
426raid5_end_read_request(struct bio *bi, int error);
427static void
428raid5_end_write_request(struct bio *bi, int error);
Dan Williams91c00922007-01-02 13:52:30 -0700429
Dan Williamsc4e5ac02008-06-28 08:31:53 +1000430static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
Dan Williams91c00922007-01-02 13:52:30 -0700431{
432 raid5_conf_t *conf = sh->raid_conf;
433 int i, disks = sh->disks;
434
435 might_sleep();
436
437 for (i = disks; i--; ) {
438 int rw;
439 struct bio *bi;
440 mdk_rdev_t *rdev;
441 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
442 rw = WRITE;
443 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
444 rw = READ;
445 else
446 continue;
447
448 bi = &sh->dev[i].req;
449
450 bi->bi_rw = rw;
451 if (rw == WRITE)
452 bi->bi_end_io = raid5_end_write_request;
453 else
454 bi->bi_end_io = raid5_end_read_request;
455
456 rcu_read_lock();
457 rdev = rcu_dereference(conf->disks[i].rdev);
458 if (rdev && test_bit(Faulty, &rdev->flags))
459 rdev = NULL;
460 if (rdev)
461 atomic_inc(&rdev->nr_pending);
462 rcu_read_unlock();
463
464 if (rdev) {
Dan Williamsc4e5ac02008-06-28 08:31:53 +1000465 if (s->syncing || s->expanding || s->expanded)
Dan Williams91c00922007-01-02 13:52:30 -0700466 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
467
Dan Williams2b7497f2008-06-28 08:31:52 +1000468 set_bit(STRIPE_IO_STARTED, &sh->state);
469
Dan Williams91c00922007-01-02 13:52:30 -0700470 bi->bi_bdev = rdev->bdev;
471 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700472 __func__, (unsigned long long)sh->sector,
Dan Williams91c00922007-01-02 13:52:30 -0700473 bi->bi_rw, i);
474 atomic_inc(&sh->count);
475 bi->bi_sector = sh->sector + rdev->data_offset;
476 bi->bi_flags = 1 << BIO_UPTODATE;
477 bi->bi_vcnt = 1;
478 bi->bi_max_vecs = 1;
479 bi->bi_idx = 0;
480 bi->bi_io_vec = &sh->dev[i].vec;
481 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
482 bi->bi_io_vec[0].bv_offset = 0;
483 bi->bi_size = STRIPE_SIZE;
484 bi->bi_next = NULL;
485 if (rw == WRITE &&
486 test_bit(R5_ReWrite, &sh->dev[i].flags))
487 atomic_add(STRIPE_SECTORS,
488 &rdev->corrected_errors);
489 generic_make_request(bi);
490 } else {
491 if (rw == WRITE)
492 set_bit(STRIPE_DEGRADED, &sh->state);
493 pr_debug("skip op %ld on disc %d for sector %llu\n",
494 bi->bi_rw, i, (unsigned long long)sh->sector);
495 clear_bit(R5_LOCKED, &sh->dev[i].flags);
496 set_bit(STRIPE_HANDLE, &sh->state);
497 }
498 }
499}
500
501static struct dma_async_tx_descriptor *
502async_copy_data(int frombio, struct bio *bio, struct page *page,
503 sector_t sector, struct dma_async_tx_descriptor *tx)
504{
505 struct bio_vec *bvl;
506 struct page *bio_page;
507 int i;
508 int page_offset;
Dan Williamsa08abd82009-06-03 11:43:59 -0700509 struct async_submit_ctl submit;
Dan Williams0403e382009-09-08 17:42:50 -0700510 enum async_tx_flags flags = 0;
Dan Williams91c00922007-01-02 13:52:30 -0700511
512 if (bio->bi_sector >= sector)
513 page_offset = (signed)(bio->bi_sector - sector) * 512;
514 else
515 page_offset = (signed)(sector - bio->bi_sector) * -512;
Dan Williamsa08abd82009-06-03 11:43:59 -0700516
Dan Williams0403e382009-09-08 17:42:50 -0700517 if (frombio)
518 flags |= ASYNC_TX_FENCE;
519 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
520
Dan Williams91c00922007-01-02 13:52:30 -0700521 bio_for_each_segment(bvl, bio, i) {
522 int len = bio_iovec_idx(bio, i)->bv_len;
523 int clen;
524 int b_offset = 0;
525
526 if (page_offset < 0) {
527 b_offset = -page_offset;
528 page_offset += b_offset;
529 len -= b_offset;
530 }
531
532 if (len > 0 && page_offset + len > STRIPE_SIZE)
533 clen = STRIPE_SIZE - page_offset;
534 else
535 clen = len;
536
537 if (clen > 0) {
538 b_offset += bio_iovec_idx(bio, i)->bv_offset;
539 bio_page = bio_iovec_idx(bio, i)->bv_page;
540 if (frombio)
541 tx = async_memcpy(page, bio_page, page_offset,
Dan Williamsa08abd82009-06-03 11:43:59 -0700542 b_offset, clen, &submit);
Dan Williams91c00922007-01-02 13:52:30 -0700543 else
544 tx = async_memcpy(bio_page, page, b_offset,
Dan Williamsa08abd82009-06-03 11:43:59 -0700545 page_offset, clen, &submit);
Dan Williams91c00922007-01-02 13:52:30 -0700546 }
Dan Williamsa08abd82009-06-03 11:43:59 -0700547 /* chain the operations */
548 submit.depend_tx = tx;
549
Dan Williams91c00922007-01-02 13:52:30 -0700550 if (clen < len) /* hit end of page */
551 break;
552 page_offset += len;
553 }
554
555 return tx;
556}
557
558static void ops_complete_biofill(void *stripe_head_ref)
559{
560 struct stripe_head *sh = stripe_head_ref;
561 struct bio *return_bi = NULL;
562 raid5_conf_t *conf = sh->raid_conf;
Dan Williamse4d84902007-09-24 10:06:13 -0700563 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700564
Harvey Harrisone46b2722008-04-28 02:15:50 -0700565 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700566 (unsigned long long)sh->sector);
567
568 /* clear completed biofills */
Dan Williams83de75c2008-06-28 08:31:58 +1000569 spin_lock_irq(&conf->device_lock);
Dan Williams91c00922007-01-02 13:52:30 -0700570 for (i = sh->disks; i--; ) {
571 struct r5dev *dev = &sh->dev[i];
Dan Williams91c00922007-01-02 13:52:30 -0700572
573 /* acknowledge completion of a biofill operation */
Dan Williamse4d84902007-09-24 10:06:13 -0700574 /* and check if we need to reply to a read request,
575 * new R5_Wantfill requests are held off until
Dan Williams83de75c2008-06-28 08:31:58 +1000576 * !STRIPE_BIOFILL_RUN
Dan Williamse4d84902007-09-24 10:06:13 -0700577 */
578 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700579 struct bio *rbi, *rbi2;
Dan Williams91c00922007-01-02 13:52:30 -0700580
Dan Williams91c00922007-01-02 13:52:30 -0700581 BUG_ON(!dev->read);
582 rbi = dev->read;
583 dev->read = NULL;
584 while (rbi && rbi->bi_sector <
585 dev->sector + STRIPE_SECTORS) {
586 rbi2 = r5_next_bio(rbi, dev->sector);
Jens Axboe960e7392008-08-15 10:41:18 +0200587 if (!raid5_dec_bi_phys_segments(rbi)) {
Dan Williams91c00922007-01-02 13:52:30 -0700588 rbi->bi_next = return_bi;
589 return_bi = rbi;
590 }
Dan Williams91c00922007-01-02 13:52:30 -0700591 rbi = rbi2;
592 }
593 }
594 }
Dan Williams83de75c2008-06-28 08:31:58 +1000595 spin_unlock_irq(&conf->device_lock);
596 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700597
598 return_io(return_bi);
599
Dan Williamse4d84902007-09-24 10:06:13 -0700600 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williams91c00922007-01-02 13:52:30 -0700601 release_stripe(sh);
602}
603
604static void ops_run_biofill(struct stripe_head *sh)
605{
606 struct dma_async_tx_descriptor *tx = NULL;
607 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa08abd82009-06-03 11:43:59 -0700608 struct async_submit_ctl submit;
Dan Williams91c00922007-01-02 13:52:30 -0700609 int i;
610
Harvey Harrisone46b2722008-04-28 02:15:50 -0700611 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700612 (unsigned long long)sh->sector);
613
614 for (i = sh->disks; i--; ) {
615 struct r5dev *dev = &sh->dev[i];
616 if (test_bit(R5_Wantfill, &dev->flags)) {
617 struct bio *rbi;
618 spin_lock_irq(&conf->device_lock);
619 dev->read = rbi = dev->toread;
620 dev->toread = NULL;
621 spin_unlock_irq(&conf->device_lock);
622 while (rbi && rbi->bi_sector <
623 dev->sector + STRIPE_SECTORS) {
624 tx = async_copy_data(0, rbi, dev->page,
625 dev->sector, tx);
626 rbi = r5_next_bio(rbi, dev->sector);
627 }
628 }
629 }
630
631 atomic_inc(&sh->count);
Dan Williamsa08abd82009-06-03 11:43:59 -0700632 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
633 async_trigger_callback(&submit);
Dan Williams91c00922007-01-02 13:52:30 -0700634}
635
Dan Williams4e7d2c02009-08-29 19:13:11 -0700636static void mark_target_uptodate(struct stripe_head *sh, int target)
637{
638 struct r5dev *tgt;
639
640 if (target < 0)
641 return;
642
643 tgt = &sh->dev[target];
644 set_bit(R5_UPTODATE, &tgt->flags);
645 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
646 clear_bit(R5_Wantcompute, &tgt->flags);
647}
648
Dan Williamsac6b53b2009-07-14 13:40:19 -0700649static void ops_complete_compute(void *stripe_head_ref)
Dan Williams91c00922007-01-02 13:52:30 -0700650{
651 struct stripe_head *sh = stripe_head_ref;
Dan Williams91c00922007-01-02 13:52:30 -0700652
Harvey Harrisone46b2722008-04-28 02:15:50 -0700653 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700654 (unsigned long long)sh->sector);
655
Dan Williamsac6b53b2009-07-14 13:40:19 -0700656 /* mark the computed target(s) as uptodate */
Dan Williams4e7d2c02009-08-29 19:13:11 -0700657 mark_target_uptodate(sh, sh->ops.target);
Dan Williamsac6b53b2009-07-14 13:40:19 -0700658 mark_target_uptodate(sh, sh->ops.target2);
Dan Williams4e7d2c02009-08-29 19:13:11 -0700659
Dan Williamsecc65c92008-06-28 08:31:57 +1000660 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
661 if (sh->check_state == check_state_compute_run)
662 sh->check_state = check_state_compute_result;
Dan Williams91c00922007-01-02 13:52:30 -0700663 set_bit(STRIPE_HANDLE, &sh->state);
664 release_stripe(sh);
665}
666
Dan Williamsd6f38f32009-07-14 11:50:52 -0700667/* return a pointer to the address conversion region of the scribble buffer */
668static addr_conv_t *to_addr_conv(struct stripe_head *sh,
669 struct raid5_percpu *percpu)
Dan Williams91c00922007-01-02 13:52:30 -0700670{
Dan Williamsd6f38f32009-07-14 11:50:52 -0700671 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
672}
673
674static struct dma_async_tx_descriptor *
675ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
676{
Dan Williams91c00922007-01-02 13:52:30 -0700677 int disks = sh->disks;
Dan Williamsd6f38f32009-07-14 11:50:52 -0700678 struct page **xor_srcs = percpu->scribble;
Dan Williams91c00922007-01-02 13:52:30 -0700679 int target = sh->ops.target;
680 struct r5dev *tgt = &sh->dev[target];
681 struct page *xor_dest = tgt->page;
682 int count = 0;
683 struct dma_async_tx_descriptor *tx;
Dan Williamsa08abd82009-06-03 11:43:59 -0700684 struct async_submit_ctl submit;
Dan Williams91c00922007-01-02 13:52:30 -0700685 int i;
686
687 pr_debug("%s: stripe %llu block: %d\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -0700688 __func__, (unsigned long long)sh->sector, target);
Dan Williams91c00922007-01-02 13:52:30 -0700689 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
690
691 for (i = disks; i--; )
692 if (i != target)
693 xor_srcs[count++] = sh->dev[i].page;
694
695 atomic_inc(&sh->count);
696
Dan Williams0403e382009-09-08 17:42:50 -0700697 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
Dan Williamsac6b53b2009-07-14 13:40:19 -0700698 ops_complete_compute, sh, to_addr_conv(sh, percpu));
Dan Williams91c00922007-01-02 13:52:30 -0700699 if (unlikely(count == 1))
Dan Williamsa08abd82009-06-03 11:43:59 -0700700 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
Dan Williams91c00922007-01-02 13:52:30 -0700701 else
Dan Williamsa08abd82009-06-03 11:43:59 -0700702 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
Dan Williams91c00922007-01-02 13:52:30 -0700703
Dan Williams91c00922007-01-02 13:52:30 -0700704 return tx;
705}
706
Dan Williamsac6b53b2009-07-14 13:40:19 -0700707/* set_syndrome_sources - populate source buffers for gen_syndrome
708 * @srcs - (struct page *) array of size sh->disks
709 * @sh - stripe_head to parse
710 *
711 * Populates srcs in proper layout order for the stripe and returns the
712 * 'count' of sources to be used in a call to async_gen_syndrome. The P
713 * destination buffer is recorded in srcs[count] and the Q destination
714 * is recorded in srcs[count+1]].
715 */
716static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
717{
718 int disks = sh->disks;
719 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
720 int d0_idx = raid6_d0(sh);
721 int count;
722 int i;
723
724 for (i = 0; i < disks; i++)
NeilBrown5dd33c92009-10-16 16:40:25 +1100725 srcs[i] = NULL;
Dan Williamsac6b53b2009-07-14 13:40:19 -0700726
727 count = 0;
728 i = d0_idx;
729 do {
730 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
731
732 srcs[slot] = sh->dev[i].page;
733 i = raid6_next_disk(i, disks);
734 } while (i != d0_idx);
Dan Williamsac6b53b2009-07-14 13:40:19 -0700735
NeilBrowne4424fe2009-10-16 16:27:34 +1100736 return syndrome_disks;
Dan Williamsac6b53b2009-07-14 13:40:19 -0700737}
738
739static struct dma_async_tx_descriptor *
740ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
741{
742 int disks = sh->disks;
743 struct page **blocks = percpu->scribble;
744 int target;
745 int qd_idx = sh->qd_idx;
746 struct dma_async_tx_descriptor *tx;
747 struct async_submit_ctl submit;
748 struct r5dev *tgt;
749 struct page *dest;
750 int i;
751 int count;
752
753 if (sh->ops.target < 0)
754 target = sh->ops.target2;
755 else if (sh->ops.target2 < 0)
756 target = sh->ops.target;
757 else
758 /* we should only have one valid target */
759 BUG();
760 BUG_ON(target < 0);
761 pr_debug("%s: stripe %llu block: %d\n",
762 __func__, (unsigned long long)sh->sector, target);
763
764 tgt = &sh->dev[target];
765 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
766 dest = tgt->page;
767
768 atomic_inc(&sh->count);
769
770 if (target == qd_idx) {
771 count = set_syndrome_sources(blocks, sh);
772 blocks[count] = NULL; /* regenerating p is not necessary */
773 BUG_ON(blocks[count+1] != dest); /* q should already be set */
Dan Williams0403e382009-09-08 17:42:50 -0700774 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
775 ops_complete_compute, sh,
Dan Williamsac6b53b2009-07-14 13:40:19 -0700776 to_addr_conv(sh, percpu));
777 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
778 } else {
779 /* Compute any data- or p-drive using XOR */
780 count = 0;
781 for (i = disks; i-- ; ) {
782 if (i == target || i == qd_idx)
783 continue;
784 blocks[count++] = sh->dev[i].page;
785 }
786
Dan Williams0403e382009-09-08 17:42:50 -0700787 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
788 NULL, ops_complete_compute, sh,
Dan Williamsac6b53b2009-07-14 13:40:19 -0700789 to_addr_conv(sh, percpu));
790 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
791 }
792
793 return tx;
794}
795
796static struct dma_async_tx_descriptor *
797ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
798{
799 int i, count, disks = sh->disks;
800 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
801 int d0_idx = raid6_d0(sh);
802 int faila = -1, failb = -1;
803 int target = sh->ops.target;
804 int target2 = sh->ops.target2;
805 struct r5dev *tgt = &sh->dev[target];
806 struct r5dev *tgt2 = &sh->dev[target2];
807 struct dma_async_tx_descriptor *tx;
808 struct page **blocks = percpu->scribble;
809 struct async_submit_ctl submit;
810
811 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
812 __func__, (unsigned long long)sh->sector, target, target2);
813 BUG_ON(target < 0 || target2 < 0);
814 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
815 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
816
Dan Williams6c910a72009-09-16 12:24:54 -0700817 /* we need to open-code set_syndrome_sources to handle the
Dan Williamsac6b53b2009-07-14 13:40:19 -0700818 * slot number conversion for 'faila' and 'failb'
819 */
820 for (i = 0; i < disks ; i++)
NeilBrown5dd33c92009-10-16 16:40:25 +1100821 blocks[i] = NULL;
Dan Williamsac6b53b2009-07-14 13:40:19 -0700822 count = 0;
823 i = d0_idx;
824 do {
825 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
826
827 blocks[slot] = sh->dev[i].page;
828
829 if (i == target)
830 faila = slot;
831 if (i == target2)
832 failb = slot;
833 i = raid6_next_disk(i, disks);
834 } while (i != d0_idx);
Dan Williamsac6b53b2009-07-14 13:40:19 -0700835
836 BUG_ON(faila == failb);
837 if (failb < faila)
838 swap(faila, failb);
839 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
840 __func__, (unsigned long long)sh->sector, faila, failb);
841
842 atomic_inc(&sh->count);
843
844 if (failb == syndrome_disks+1) {
845 /* Q disk is one of the missing disks */
846 if (faila == syndrome_disks) {
847 /* Missing P+Q, just recompute */
Dan Williams0403e382009-09-08 17:42:50 -0700848 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
849 ops_complete_compute, sh,
850 to_addr_conv(sh, percpu));
NeilBrowne4424fe2009-10-16 16:27:34 +1100851 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
Dan Williamsac6b53b2009-07-14 13:40:19 -0700852 STRIPE_SIZE, &submit);
853 } else {
854 struct page *dest;
855 int data_target;
856 int qd_idx = sh->qd_idx;
857
858 /* Missing D+Q: recompute D from P, then recompute Q */
859 if (target == qd_idx)
860 data_target = target2;
861 else
862 data_target = target;
863
864 count = 0;
865 for (i = disks; i-- ; ) {
866 if (i == data_target || i == qd_idx)
867 continue;
868 blocks[count++] = sh->dev[i].page;
869 }
870 dest = sh->dev[data_target].page;
Dan Williams0403e382009-09-08 17:42:50 -0700871 init_async_submit(&submit,
872 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
873 NULL, NULL, NULL,
874 to_addr_conv(sh, percpu));
Dan Williamsac6b53b2009-07-14 13:40:19 -0700875 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
876 &submit);
877
878 count = set_syndrome_sources(blocks, sh);
Dan Williams0403e382009-09-08 17:42:50 -0700879 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
880 ops_complete_compute, sh,
881 to_addr_conv(sh, percpu));
Dan Williamsac6b53b2009-07-14 13:40:19 -0700882 return async_gen_syndrome(blocks, 0, count+2,
883 STRIPE_SIZE, &submit);
884 }
Dan Williamsac6b53b2009-07-14 13:40:19 -0700885 } else {
Dan Williams6c910a72009-09-16 12:24:54 -0700886 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
887 ops_complete_compute, sh,
888 to_addr_conv(sh, percpu));
889 if (failb == syndrome_disks) {
890 /* We're missing D+P. */
891 return async_raid6_datap_recov(syndrome_disks+2,
892 STRIPE_SIZE, faila,
893 blocks, &submit);
894 } else {
895 /* We're missing D+D. */
896 return async_raid6_2data_recov(syndrome_disks+2,
897 STRIPE_SIZE, faila, failb,
898 blocks, &submit);
899 }
Dan Williamsac6b53b2009-07-14 13:40:19 -0700900 }
901}
902
903
Dan Williams91c00922007-01-02 13:52:30 -0700904static void ops_complete_prexor(void *stripe_head_ref)
905{
906 struct stripe_head *sh = stripe_head_ref;
907
Harvey Harrisone46b2722008-04-28 02:15:50 -0700908 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700909 (unsigned long long)sh->sector);
Dan Williams91c00922007-01-02 13:52:30 -0700910}
911
912static struct dma_async_tx_descriptor *
Dan Williamsd6f38f32009-07-14 11:50:52 -0700913ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
914 struct dma_async_tx_descriptor *tx)
Dan Williams91c00922007-01-02 13:52:30 -0700915{
Dan Williams91c00922007-01-02 13:52:30 -0700916 int disks = sh->disks;
Dan Williamsd6f38f32009-07-14 11:50:52 -0700917 struct page **xor_srcs = percpu->scribble;
Dan Williams91c00922007-01-02 13:52:30 -0700918 int count = 0, pd_idx = sh->pd_idx, i;
Dan Williamsa08abd82009-06-03 11:43:59 -0700919 struct async_submit_ctl submit;
Dan Williams91c00922007-01-02 13:52:30 -0700920
921 /* existing parity data subtracted */
922 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
923
Harvey Harrisone46b2722008-04-28 02:15:50 -0700924 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700925 (unsigned long long)sh->sector);
926
927 for (i = disks; i--; ) {
928 struct r5dev *dev = &sh->dev[i];
929 /* Only process blocks that are known to be uptodate */
Dan Williamsd8ee0722008-06-28 08:32:06 +1000930 if (test_bit(R5_Wantdrain, &dev->flags))
Dan Williams91c00922007-01-02 13:52:30 -0700931 xor_srcs[count++] = dev->page;
932 }
933
Dan Williams0403e382009-09-08 17:42:50 -0700934 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
Dan Williamsd6f38f32009-07-14 11:50:52 -0700935 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
Dan Williamsa08abd82009-06-03 11:43:59 -0700936 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
Dan Williams91c00922007-01-02 13:52:30 -0700937
938 return tx;
939}
940
941static struct dma_async_tx_descriptor *
Dan Williamsd8ee0722008-06-28 08:32:06 +1000942ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
Dan Williams91c00922007-01-02 13:52:30 -0700943{
944 int disks = sh->disks;
Dan Williamsd8ee0722008-06-28 08:32:06 +1000945 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700946
Harvey Harrisone46b2722008-04-28 02:15:50 -0700947 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700948 (unsigned long long)sh->sector);
949
950 for (i = disks; i--; ) {
951 struct r5dev *dev = &sh->dev[i];
952 struct bio *chosen;
Dan Williams91c00922007-01-02 13:52:30 -0700953
Dan Williamsd8ee0722008-06-28 08:32:06 +1000954 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
Dan Williams91c00922007-01-02 13:52:30 -0700955 struct bio *wbi;
956
957 spin_lock(&sh->lock);
958 chosen = dev->towrite;
959 dev->towrite = NULL;
960 BUG_ON(dev->written);
961 wbi = dev->written = chosen;
962 spin_unlock(&sh->lock);
963
964 while (wbi && wbi->bi_sector <
965 dev->sector + STRIPE_SECTORS) {
966 tx = async_copy_data(1, wbi, dev->page,
967 dev->sector, tx);
968 wbi = r5_next_bio(wbi, dev->sector);
969 }
970 }
971 }
972
973 return tx;
974}
975
Dan Williamsac6b53b2009-07-14 13:40:19 -0700976static void ops_complete_reconstruct(void *stripe_head_ref)
Dan Williams91c00922007-01-02 13:52:30 -0700977{
978 struct stripe_head *sh = stripe_head_ref;
Dan Williamsac6b53b2009-07-14 13:40:19 -0700979 int disks = sh->disks;
980 int pd_idx = sh->pd_idx;
981 int qd_idx = sh->qd_idx;
982 int i;
Dan Williams91c00922007-01-02 13:52:30 -0700983
Harvey Harrisone46b2722008-04-28 02:15:50 -0700984 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -0700985 (unsigned long long)sh->sector);
986
987 for (i = disks; i--; ) {
988 struct r5dev *dev = &sh->dev[i];
Dan Williamsac6b53b2009-07-14 13:40:19 -0700989
990 if (dev->written || i == pd_idx || i == qd_idx)
Dan Williams91c00922007-01-02 13:52:30 -0700991 set_bit(R5_UPTODATE, &dev->flags);
992 }
993
Dan Williamsd8ee0722008-06-28 08:32:06 +1000994 if (sh->reconstruct_state == reconstruct_state_drain_run)
995 sh->reconstruct_state = reconstruct_state_drain_result;
996 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
997 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
998 else {
999 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1000 sh->reconstruct_state = reconstruct_state_result;
1001 }
Dan Williams91c00922007-01-02 13:52:30 -07001002
1003 set_bit(STRIPE_HANDLE, &sh->state);
1004 release_stripe(sh);
1005}
1006
1007static void
Dan Williamsac6b53b2009-07-14 13:40:19 -07001008ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1009 struct dma_async_tx_descriptor *tx)
Dan Williams91c00922007-01-02 13:52:30 -07001010{
Dan Williams91c00922007-01-02 13:52:30 -07001011 int disks = sh->disks;
Dan Williamsd6f38f32009-07-14 11:50:52 -07001012 struct page **xor_srcs = percpu->scribble;
Dan Williamsa08abd82009-06-03 11:43:59 -07001013 struct async_submit_ctl submit;
Dan Williams91c00922007-01-02 13:52:30 -07001014 int count = 0, pd_idx = sh->pd_idx, i;
1015 struct page *xor_dest;
Dan Williamsd8ee0722008-06-28 08:32:06 +10001016 int prexor = 0;
Dan Williams91c00922007-01-02 13:52:30 -07001017 unsigned long flags;
Dan Williams91c00922007-01-02 13:52:30 -07001018
Harvey Harrisone46b2722008-04-28 02:15:50 -07001019 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -07001020 (unsigned long long)sh->sector);
1021
1022 /* check if prexor is active which means only process blocks
1023 * that are part of a read-modify-write (written)
1024 */
Dan Williamsd8ee0722008-06-28 08:32:06 +10001025 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1026 prexor = 1;
Dan Williams91c00922007-01-02 13:52:30 -07001027 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1028 for (i = disks; i--; ) {
1029 struct r5dev *dev = &sh->dev[i];
1030 if (dev->written)
1031 xor_srcs[count++] = dev->page;
1032 }
1033 } else {
1034 xor_dest = sh->dev[pd_idx].page;
1035 for (i = disks; i--; ) {
1036 struct r5dev *dev = &sh->dev[i];
1037 if (i != pd_idx)
1038 xor_srcs[count++] = dev->page;
1039 }
1040 }
1041
Dan Williams91c00922007-01-02 13:52:30 -07001042 /* 1/ if we prexor'd then the dest is reused as a source
1043 * 2/ if we did not prexor then we are redoing the parity
1044 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1045 * for the synchronous xor case
1046 */
Dan Williams88ba2aa2009-04-09 16:16:18 -07001047 flags = ASYNC_TX_ACK |
Dan Williams91c00922007-01-02 13:52:30 -07001048 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1049
1050 atomic_inc(&sh->count);
1051
Dan Williamsac6b53b2009-07-14 13:40:19 -07001052 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
Dan Williamsd6f38f32009-07-14 11:50:52 -07001053 to_addr_conv(sh, percpu));
Dan Williamsa08abd82009-06-03 11:43:59 -07001054 if (unlikely(count == 1))
1055 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1056 else
1057 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
Dan Williams91c00922007-01-02 13:52:30 -07001058}
1059
Dan Williamsac6b53b2009-07-14 13:40:19 -07001060static void
1061ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1062 struct dma_async_tx_descriptor *tx)
1063{
1064 struct async_submit_ctl submit;
1065 struct page **blocks = percpu->scribble;
1066 int count;
1067
1068 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1069
1070 count = set_syndrome_sources(blocks, sh);
1071
1072 atomic_inc(&sh->count);
1073
1074 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1075 sh, to_addr_conv(sh, percpu));
1076 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
Dan Williams91c00922007-01-02 13:52:30 -07001077}
1078
1079static void ops_complete_check(void *stripe_head_ref)
1080{
1081 struct stripe_head *sh = stripe_head_ref;
Dan Williams91c00922007-01-02 13:52:30 -07001082
Harvey Harrisone46b2722008-04-28 02:15:50 -07001083 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -07001084 (unsigned long long)sh->sector);
1085
Dan Williamsecc65c92008-06-28 08:31:57 +10001086 sh->check_state = check_state_check_result;
Dan Williams91c00922007-01-02 13:52:30 -07001087 set_bit(STRIPE_HANDLE, &sh->state);
1088 release_stripe(sh);
1089}
1090
Dan Williamsac6b53b2009-07-14 13:40:19 -07001091static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
Dan Williams91c00922007-01-02 13:52:30 -07001092{
Dan Williams91c00922007-01-02 13:52:30 -07001093 int disks = sh->disks;
Dan Williamsac6b53b2009-07-14 13:40:19 -07001094 int pd_idx = sh->pd_idx;
1095 int qd_idx = sh->qd_idx;
1096 struct page *xor_dest;
Dan Williamsd6f38f32009-07-14 11:50:52 -07001097 struct page **xor_srcs = percpu->scribble;
Dan Williams91c00922007-01-02 13:52:30 -07001098 struct dma_async_tx_descriptor *tx;
Dan Williamsa08abd82009-06-03 11:43:59 -07001099 struct async_submit_ctl submit;
Dan Williamsac6b53b2009-07-14 13:40:19 -07001100 int count;
1101 int i;
Dan Williams91c00922007-01-02 13:52:30 -07001102
Harvey Harrisone46b2722008-04-28 02:15:50 -07001103 pr_debug("%s: stripe %llu\n", __func__,
Dan Williams91c00922007-01-02 13:52:30 -07001104 (unsigned long long)sh->sector);
1105
Dan Williamsac6b53b2009-07-14 13:40:19 -07001106 count = 0;
1107 xor_dest = sh->dev[pd_idx].page;
1108 xor_srcs[count++] = xor_dest;
Dan Williams91c00922007-01-02 13:52:30 -07001109 for (i = disks; i--; ) {
Dan Williamsac6b53b2009-07-14 13:40:19 -07001110 if (i == pd_idx || i == qd_idx)
1111 continue;
1112 xor_srcs[count++] = sh->dev[i].page;
Dan Williams91c00922007-01-02 13:52:30 -07001113 }
1114
Dan Williamsd6f38f32009-07-14 11:50:52 -07001115 init_async_submit(&submit, 0, NULL, NULL, NULL,
1116 to_addr_conv(sh, percpu));
Dan Williams099f53c2009-04-08 14:28:37 -07001117 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
Dan Williamsa08abd82009-06-03 11:43:59 -07001118 &sh->ops.zero_sum_result, &submit);
Dan Williams91c00922007-01-02 13:52:30 -07001119
Dan Williams91c00922007-01-02 13:52:30 -07001120 atomic_inc(&sh->count);
Dan Williamsa08abd82009-06-03 11:43:59 -07001121 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1122 tx = async_trigger_callback(&submit);
Dan Williams91c00922007-01-02 13:52:30 -07001123}
1124
Dan Williamsac6b53b2009-07-14 13:40:19 -07001125static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1126{
1127 struct page **srcs = percpu->scribble;
1128 struct async_submit_ctl submit;
1129 int count;
1130
1131 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1132 (unsigned long long)sh->sector, checkp);
1133
1134 count = set_syndrome_sources(srcs, sh);
1135 if (!checkp)
1136 srcs[count] = NULL;
1137
1138 atomic_inc(&sh->count);
1139 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1140 sh, to_addr_conv(sh, percpu));
1141 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1142 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1143}
1144
Dan Williams417b8d42009-10-16 16:25:22 +11001145static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
Dan Williams91c00922007-01-02 13:52:30 -07001146{
1147 int overlap_clear = 0, i, disks = sh->disks;
1148 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsd6f38f32009-07-14 11:50:52 -07001149 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsac6b53b2009-07-14 13:40:19 -07001150 int level = conf->level;
Dan Williamsd6f38f32009-07-14 11:50:52 -07001151 struct raid5_percpu *percpu;
1152 unsigned long cpu;
Dan Williams91c00922007-01-02 13:52:30 -07001153
Dan Williamsd6f38f32009-07-14 11:50:52 -07001154 cpu = get_cpu();
1155 percpu = per_cpu_ptr(conf->percpu, cpu);
Dan Williams83de75c2008-06-28 08:31:58 +10001156 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
Dan Williams91c00922007-01-02 13:52:30 -07001157 ops_run_biofill(sh);
1158 overlap_clear++;
1159 }
1160
Dan Williams7b3a8712008-06-28 08:32:09 +10001161 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
Dan Williamsac6b53b2009-07-14 13:40:19 -07001162 if (level < 6)
1163 tx = ops_run_compute5(sh, percpu);
1164 else {
1165 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1166 tx = ops_run_compute6_1(sh, percpu);
1167 else
1168 tx = ops_run_compute6_2(sh, percpu);
1169 }
1170 /* terminate the chain if reconstruct is not set to be run */
1171 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
Dan Williams7b3a8712008-06-28 08:32:09 +10001172 async_tx_ack(tx);
1173 }
Dan Williams91c00922007-01-02 13:52:30 -07001174
Dan Williams600aa102008-06-28 08:32:05 +10001175 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
Dan Williamsd6f38f32009-07-14 11:50:52 -07001176 tx = ops_run_prexor(sh, percpu, tx);
Dan Williams91c00922007-01-02 13:52:30 -07001177
Dan Williams600aa102008-06-28 08:32:05 +10001178 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
Dan Williamsd8ee0722008-06-28 08:32:06 +10001179 tx = ops_run_biodrain(sh, tx);
Dan Williams91c00922007-01-02 13:52:30 -07001180 overlap_clear++;
1181 }
1182
Dan Williamsac6b53b2009-07-14 13:40:19 -07001183 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1184 if (level < 6)
1185 ops_run_reconstruct5(sh, percpu, tx);
1186 else
1187 ops_run_reconstruct6(sh, percpu, tx);
1188 }
Dan Williams91c00922007-01-02 13:52:30 -07001189
Dan Williamsac6b53b2009-07-14 13:40:19 -07001190 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1191 if (sh->check_state == check_state_run)
1192 ops_run_check_p(sh, percpu);
1193 else if (sh->check_state == check_state_run_q)
1194 ops_run_check_pq(sh, percpu, 0);
1195 else if (sh->check_state == check_state_run_pq)
1196 ops_run_check_pq(sh, percpu, 1);
1197 else
1198 BUG();
1199 }
Dan Williams91c00922007-01-02 13:52:30 -07001200
Dan Williams91c00922007-01-02 13:52:30 -07001201 if (overlap_clear)
1202 for (i = disks; i--; ) {
1203 struct r5dev *dev = &sh->dev[i];
1204 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1205 wake_up(&sh->raid_conf->wait_for_overlap);
1206 }
Dan Williamsd6f38f32009-07-14 11:50:52 -07001207 put_cpu();
Dan Williams91c00922007-01-02 13:52:30 -07001208}
1209
Dan Williams417b8d42009-10-16 16:25:22 +11001210#ifdef CONFIG_MULTICORE_RAID456
1211static void async_run_ops(void *param, async_cookie_t cookie)
1212{
1213 struct stripe_head *sh = param;
1214 unsigned long ops_request = sh->ops.request;
1215
1216 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
1217 wake_up(&sh->ops.wait_for_ops);
1218
1219 __raid_run_ops(sh, ops_request);
1220 release_stripe(sh);
1221}
1222
1223static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1224{
1225 /* since handle_stripe can be called outside of raid5d context
1226 * we need to ensure sh->ops.request is de-staged before another
1227 * request arrives
1228 */
1229 wait_event(sh->ops.wait_for_ops,
1230 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
1231 sh->ops.request = ops_request;
1232
1233 atomic_inc(&sh->count);
1234 async_schedule(async_run_ops, sh);
1235}
1236#else
1237#define raid_run_ops __raid_run_ops
1238#endif
1239
NeilBrown3f294f42005-11-08 21:39:25 -08001240static int grow_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241{
1242 struct stripe_head *sh;
NeilBrown5e5e3e72009-10-16 16:35:30 +11001243 int disks = max(conf->raid_disks, conf->previous_raid_disks);
NeilBrown3f294f42005-11-08 21:39:25 -08001244 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
1245 if (!sh)
1246 return 0;
NeilBrown5e5e3e72009-10-16 16:35:30 +11001247 memset(sh, 0, sizeof(*sh) + (disks-1)*sizeof(struct r5dev));
NeilBrown3f294f42005-11-08 21:39:25 -08001248 sh->raid_conf = conf;
1249 spin_lock_init(&sh->lock);
Dan Williams417b8d42009-10-16 16:25:22 +11001250 #ifdef CONFIG_MULTICORE_RAID456
1251 init_waitqueue_head(&sh->ops.wait_for_ops);
1252 #endif
NeilBrown3f294f42005-11-08 21:39:25 -08001253
NeilBrown5e5e3e72009-10-16 16:35:30 +11001254 if (grow_buffers(sh, disks)) {
1255 shrink_buffers(sh, disks);
NeilBrown3f294f42005-11-08 21:39:25 -08001256 kmem_cache_free(conf->slab_cache, sh);
1257 return 0;
1258 }
1259 /* we just created an active stripe so... */
1260 atomic_set(&sh->count, 1);
1261 atomic_inc(&conf->active_stripes);
1262 INIT_LIST_HEAD(&sh->lru);
1263 release_stripe(sh);
1264 return 1;
1265}
1266
1267static int grow_stripes(raid5_conf_t *conf, int num)
1268{
Christoph Lametere18b8902006-12-06 20:33:20 -08001269 struct kmem_cache *sc;
NeilBrown5e5e3e72009-10-16 16:35:30 +11001270 int devs = max(conf->raid_disks, conf->previous_raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271
NeilBrown245f46c2009-03-31 14:39:39 +11001272 sprintf(conf->cache_name[0],
1273 "raid%d-%s", conf->level, mdname(conf->mddev));
1274 sprintf(conf->cache_name[1],
1275 "raid%d-%s-alt", conf->level, mdname(conf->mddev));
NeilBrownad01c9e2006-03-27 01:18:07 -08001276 conf->active_name = 0;
1277 sc = kmem_cache_create(conf->cache_name[conf->active_name],
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +09001279 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 if (!sc)
1281 return 1;
1282 conf->slab_cache = sc;
NeilBrownad01c9e2006-03-27 01:18:07 -08001283 conf->pool_size = devs;
NeilBrown16a53ec2006-06-26 00:27:38 -07001284 while (num--)
NeilBrown3f294f42005-11-08 21:39:25 -08001285 if (!grow_one_stripe(conf))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 return 0;
1288}
NeilBrown29269552006-03-27 01:18:10 -08001289
Dan Williamsd6f38f32009-07-14 11:50:52 -07001290/**
1291 * scribble_len - return the required size of the scribble region
1292 * @num - total number of disks in the array
1293 *
1294 * The size must be enough to contain:
1295 * 1/ a struct page pointer for each device in the array +2
1296 * 2/ room to convert each entry in (1) to its corresponding dma
1297 * (dma_map_page()) or page (page_address()) address.
1298 *
1299 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1300 * calculate over all devices (not just the data blocks), using zeros in place
1301 * of the P and Q blocks.
1302 */
1303static size_t scribble_len(int num)
1304{
1305 size_t len;
1306
1307 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1308
1309 return len;
1310}
1311
NeilBrownad01c9e2006-03-27 01:18:07 -08001312static int resize_stripes(raid5_conf_t *conf, int newsize)
1313{
1314 /* Make all the stripes able to hold 'newsize' devices.
1315 * New slots in each stripe get 'page' set to a new page.
1316 *
1317 * This happens in stages:
1318 * 1/ create a new kmem_cache and allocate the required number of
1319 * stripe_heads.
1320 * 2/ gather all the old stripe_heads and tranfer the pages across
1321 * to the new stripe_heads. This will have the side effect of
1322 * freezing the array as once all stripe_heads have been collected,
1323 * no IO will be possible. Old stripe heads are freed once their
1324 * pages have been transferred over, and the old kmem_cache is
1325 * freed when all stripes are done.
1326 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1327 * we simple return a failre status - no need to clean anything up.
1328 * 4/ allocate new pages for the new slots in the new stripe_heads.
1329 * If this fails, we don't bother trying the shrink the
1330 * stripe_heads down again, we just leave them as they are.
1331 * As each stripe_head is processed the new one is released into
1332 * active service.
1333 *
1334 * Once step2 is started, we cannot afford to wait for a write,
1335 * so we use GFP_NOIO allocations.
1336 */
1337 struct stripe_head *osh, *nsh;
1338 LIST_HEAD(newstripes);
1339 struct disk_info *ndisks;
Dan Williamsd6f38f32009-07-14 11:50:52 -07001340 unsigned long cpu;
Dan Williamsb5470dc2008-06-27 21:44:04 -07001341 int err;
Christoph Lametere18b8902006-12-06 20:33:20 -08001342 struct kmem_cache *sc;
NeilBrownad01c9e2006-03-27 01:18:07 -08001343 int i;
1344
1345 if (newsize <= conf->pool_size)
1346 return 0; /* never bother to shrink */
1347
Dan Williamsb5470dc2008-06-27 21:44:04 -07001348 err = md_allow_write(conf->mddev);
1349 if (err)
1350 return err;
NeilBrown2a2275d2007-01-26 00:57:11 -08001351
NeilBrownad01c9e2006-03-27 01:18:07 -08001352 /* Step 1 */
1353 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1354 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
Paul Mundt20c2df82007-07-20 10:11:58 +09001355 0, 0, NULL);
NeilBrownad01c9e2006-03-27 01:18:07 -08001356 if (!sc)
1357 return -ENOMEM;
1358
1359 for (i = conf->max_nr_stripes; i; i--) {
1360 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1361 if (!nsh)
1362 break;
1363
1364 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1365
1366 nsh->raid_conf = conf;
1367 spin_lock_init(&nsh->lock);
Dan Williams417b8d42009-10-16 16:25:22 +11001368 #ifdef CONFIG_MULTICORE_RAID456
1369 init_waitqueue_head(&nsh->ops.wait_for_ops);
1370 #endif
NeilBrownad01c9e2006-03-27 01:18:07 -08001371
1372 list_add(&nsh->lru, &newstripes);
1373 }
1374 if (i) {
1375 /* didn't get enough, give up */
1376 while (!list_empty(&newstripes)) {
1377 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1378 list_del(&nsh->lru);
1379 kmem_cache_free(sc, nsh);
1380 }
1381 kmem_cache_destroy(sc);
1382 return -ENOMEM;
1383 }
1384 /* Step 2 - Must use GFP_NOIO now.
1385 * OK, we have enough stripes, start collecting inactive
1386 * stripes and copying them over
1387 */
1388 list_for_each_entry(nsh, &newstripes, lru) {
1389 spin_lock_irq(&conf->device_lock);
1390 wait_event_lock_irq(conf->wait_for_stripe,
1391 !list_empty(&conf->inactive_list),
1392 conf->device_lock,
NeilBrownb3b46be2006-03-27 01:18:16 -08001393 unplug_slaves(conf->mddev)
NeilBrownad01c9e2006-03-27 01:18:07 -08001394 );
1395 osh = get_free_stripe(conf);
1396 spin_unlock_irq(&conf->device_lock);
1397 atomic_set(&nsh->count, 1);
1398 for(i=0; i<conf->pool_size; i++)
1399 nsh->dev[i].page = osh->dev[i].page;
1400 for( ; i<newsize; i++)
1401 nsh->dev[i].page = NULL;
1402 kmem_cache_free(conf->slab_cache, osh);
1403 }
1404 kmem_cache_destroy(conf->slab_cache);
1405
1406 /* Step 3.
1407 * At this point, we are holding all the stripes so the array
1408 * is completely stalled, so now is a good time to resize
Dan Williamsd6f38f32009-07-14 11:50:52 -07001409 * conf->disks and the scribble region
NeilBrownad01c9e2006-03-27 01:18:07 -08001410 */
1411 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1412 if (ndisks) {
1413 for (i=0; i<conf->raid_disks; i++)
1414 ndisks[i] = conf->disks[i];
1415 kfree(conf->disks);
1416 conf->disks = ndisks;
1417 } else
1418 err = -ENOMEM;
1419
Dan Williamsd6f38f32009-07-14 11:50:52 -07001420 get_online_cpus();
1421 conf->scribble_len = scribble_len(newsize);
1422 for_each_present_cpu(cpu) {
1423 struct raid5_percpu *percpu;
1424 void *scribble;
1425
1426 percpu = per_cpu_ptr(conf->percpu, cpu);
1427 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1428
1429 if (scribble) {
1430 kfree(percpu->scribble);
1431 percpu->scribble = scribble;
1432 } else {
1433 err = -ENOMEM;
1434 break;
1435 }
1436 }
1437 put_online_cpus();
1438
NeilBrownad01c9e2006-03-27 01:18:07 -08001439 /* Step 4, return new stripes to service */
1440 while(!list_empty(&newstripes)) {
1441 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1442 list_del_init(&nsh->lru);
Dan Williamsd6f38f32009-07-14 11:50:52 -07001443
NeilBrownad01c9e2006-03-27 01:18:07 -08001444 for (i=conf->raid_disks; i < newsize; i++)
1445 if (nsh->dev[i].page == NULL) {
1446 struct page *p = alloc_page(GFP_NOIO);
1447 nsh->dev[i].page = p;
1448 if (!p)
1449 err = -ENOMEM;
1450 }
1451 release_stripe(nsh);
1452 }
1453 /* critical section pass, GFP_NOIO no longer needed */
1454
1455 conf->slab_cache = sc;
1456 conf->active_name = 1-conf->active_name;
1457 conf->pool_size = newsize;
1458 return err;
1459}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460
NeilBrown3f294f42005-11-08 21:39:25 -08001461static int drop_one_stripe(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462{
1463 struct stripe_head *sh;
1464
NeilBrown3f294f42005-11-08 21:39:25 -08001465 spin_lock_irq(&conf->device_lock);
1466 sh = get_free_stripe(conf);
1467 spin_unlock_irq(&conf->device_lock);
1468 if (!sh)
1469 return 0;
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02001470 BUG_ON(atomic_read(&sh->count));
NeilBrownad01c9e2006-03-27 01:18:07 -08001471 shrink_buffers(sh, conf->pool_size);
NeilBrown3f294f42005-11-08 21:39:25 -08001472 kmem_cache_free(conf->slab_cache, sh);
1473 atomic_dec(&conf->active_stripes);
1474 return 1;
1475}
1476
1477static void shrink_stripes(raid5_conf_t *conf)
1478{
1479 while (drop_one_stripe(conf))
1480 ;
1481
NeilBrown29fc7e32006-02-03 03:03:41 -08001482 if (conf->slab_cache)
1483 kmem_cache_destroy(conf->slab_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 conf->slab_cache = NULL;
1485}
1486
NeilBrown6712ecf2007-09-27 12:47:43 +02001487static void raid5_end_read_request(struct bio * bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488{
NeilBrown99c0fb52009-03-31 14:39:38 +11001489 struct stripe_head *sh = bi->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001491 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
NeilBrownd6950432006-07-10 04:44:20 -07001493 char b[BDEVNAME_SIZE];
1494 mdk_rdev_t *rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496
1497 for (i=0 ; i<disks; i++)
1498 if (bi == &sh->dev[i].req)
1499 break;
1500
Dan Williams45b42332007-07-09 11:56:43 -07001501 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1502 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 uptodate);
1504 if (i == disks) {
1505 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001506 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 }
1508
1509 if (uptodate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 set_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrown4e5314b2005-11-08 21:39:22 -08001511 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
NeilBrownd6950432006-07-10 04:44:20 -07001512 rdev = conf->disks[i].rdev;
NeilBrown0c55e022010-05-03 14:09:02 +10001513 printk_rl(KERN_INFO "md/raid:%s: read error corrected"
Bernd Schubert6be9d492008-05-23 13:04:34 -07001514 " (%lu sectors at %llu on %s)\n",
1515 mdname(conf->mddev), STRIPE_SECTORS,
1516 (unsigned long long)(sh->sector
1517 + rdev->data_offset),
1518 bdevname(rdev->bdev, b));
NeilBrown4e5314b2005-11-08 21:39:22 -08001519 clear_bit(R5_ReadError, &sh->dev[i].flags);
1520 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1521 }
NeilBrownba22dcb2005-11-08 21:39:31 -08001522 if (atomic_read(&conf->disks[i].rdev->read_errors))
1523 atomic_set(&conf->disks[i].rdev->read_errors, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 } else {
NeilBrownd6950432006-07-10 04:44:20 -07001525 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
NeilBrownba22dcb2005-11-08 21:39:31 -08001526 int retry = 0;
NeilBrownd6950432006-07-10 04:44:20 -07001527 rdev = conf->disks[i].rdev;
1528
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001530 atomic_inc(&rdev->read_errors);
Gabriele A. Trombetti7b0bb532010-04-28 11:51:17 +10001531 if (conf->mddev->degraded >= conf->max_degraded)
Bernd Schubert6be9d492008-05-23 13:04:34 -07001532 printk_rl(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10001533 "md/raid:%s: read error not correctable "
Bernd Schubert6be9d492008-05-23 13:04:34 -07001534 "(sector %llu on %s).\n",
1535 mdname(conf->mddev),
1536 (unsigned long long)(sh->sector
1537 + rdev->data_offset),
1538 bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001539 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
NeilBrown4e5314b2005-11-08 21:39:22 -08001540 /* Oh, no!!! */
Bernd Schubert6be9d492008-05-23 13:04:34 -07001541 printk_rl(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10001542 "md/raid:%s: read error NOT corrected!! "
Bernd Schubert6be9d492008-05-23 13:04:34 -07001543 "(sector %llu on %s).\n",
1544 mdname(conf->mddev),
1545 (unsigned long long)(sh->sector
1546 + rdev->data_offset),
1547 bdn);
NeilBrownd6950432006-07-10 04:44:20 -07001548 else if (atomic_read(&rdev->read_errors)
NeilBrownba22dcb2005-11-08 21:39:31 -08001549 > conf->max_nr_stripes)
NeilBrown14f8d262006-01-06 00:20:14 -08001550 printk(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10001551 "md/raid:%s: Too many read errors, failing device %s.\n",
NeilBrownd6950432006-07-10 04:44:20 -07001552 mdname(conf->mddev), bdn);
NeilBrownba22dcb2005-11-08 21:39:31 -08001553 else
1554 retry = 1;
1555 if (retry)
1556 set_bit(R5_ReadError, &sh->dev[i].flags);
1557 else {
NeilBrown4e5314b2005-11-08 21:39:22 -08001558 clear_bit(R5_ReadError, &sh->dev[i].flags);
1559 clear_bit(R5_ReWrite, &sh->dev[i].flags);
NeilBrownd6950432006-07-10 04:44:20 -07001560 md_error(conf->mddev, rdev);
NeilBrownba22dcb2005-11-08 21:39:31 -08001561 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 }
1563 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1565 set_bit(STRIPE_HANDLE, &sh->state);
1566 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567}
1568
NeilBrownd710e132008-10-13 11:55:12 +11001569static void raid5_end_write_request(struct bio *bi, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570{
NeilBrown99c0fb52009-03-31 14:39:38 +11001571 struct stripe_head *sh = bi->bi_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572 raid5_conf_t *conf = sh->raid_conf;
NeilBrown7ecaa1e2006-03-27 01:18:08 -08001573 int disks = sh->disks, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1575
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 for (i=0 ; i<disks; i++)
1577 if (bi == &sh->dev[i].req)
1578 break;
1579
Dan Williams45b42332007-07-09 11:56:43 -07001580 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1582 uptodate);
1583 if (i == disks) {
1584 BUG();
NeilBrown6712ecf2007-09-27 12:47:43 +02001585 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 }
1587
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 if (!uptodate)
1589 md_error(conf->mddev, conf->disks[i].rdev);
1590
1591 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1592
1593 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1594 set_bit(STRIPE_HANDLE, &sh->state);
NeilBrownc04be0a2006-10-03 01:15:53 -07001595 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596}
1597
1598
NeilBrown784052e2009-03-31 15:19:07 +11001599static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600
NeilBrown784052e2009-03-31 15:19:07 +11001601static void raid5_build_block(struct stripe_head *sh, int i, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602{
1603 struct r5dev *dev = &sh->dev[i];
1604
1605 bio_init(&dev->req);
1606 dev->req.bi_io_vec = &dev->vec;
1607 dev->req.bi_vcnt++;
1608 dev->req.bi_max_vecs++;
1609 dev->vec.bv_page = dev->page;
1610 dev->vec.bv_len = STRIPE_SIZE;
1611 dev->vec.bv_offset = 0;
1612
1613 dev->req.bi_sector = sh->sector;
1614 dev->req.bi_private = sh;
1615
1616 dev->flags = 0;
NeilBrown784052e2009-03-31 15:19:07 +11001617 dev->sector = compute_blocknr(sh, i, previous);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618}
1619
1620static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1621{
1622 char b[BDEVNAME_SIZE];
H Hartley Sweeten7b928132010-03-08 16:02:40 +11001623 raid5_conf_t *conf = mddev->private;
NeilBrown0c55e022010-05-03 14:09:02 +10001624 pr_debug("raid456: error called\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625
NeilBrownb2d444d2005-11-08 21:39:31 -08001626 if (!test_bit(Faulty, &rdev->flags)) {
NeilBrown850b2b42006-10-03 01:15:46 -07001627 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownc04be0a2006-10-03 01:15:53 -07001628 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1629 unsigned long flags;
1630 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 mddev->degraded++;
NeilBrownc04be0a2006-10-03 01:15:53 -07001632 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 /*
1634 * if recovery was running, make sure it aborts.
1635 */
NeilBrowndfc70642008-05-23 13:04:39 -07001636 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 }
NeilBrownb2d444d2005-11-08 21:39:31 -08001638 set_bit(Faulty, &rdev->flags);
NeilBrownd710e132008-10-13 11:55:12 +11001639 printk(KERN_ALERT
NeilBrown0c55e022010-05-03 14:09:02 +10001640 "md/raid:%s: Disk failure on %s, disabling device.\n"
1641 KERN_ALERT
1642 "md/raid:%s: Operation continuing on %d devices.\n",
1643 mdname(mddev),
1644 bdevname(rdev->bdev, b),
1645 mdname(mddev),
1646 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 }
NeilBrown16a53ec2006-06-26 00:27:38 -07001648}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649
1650/*
1651 * Input: a 'big' sector number,
1652 * Output: index of the data and parity disk, and the sector # in them.
1653 */
NeilBrown112bf892009-03-31 14:39:38 +11001654static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
NeilBrown911d4ee2009-03-31 14:39:38 +11001655 int previous, int *dd_idx,
1656 struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657{
NeilBrown6e3b96e2010-04-23 07:08:28 +10001658 sector_t stripe, stripe2;
NeilBrown35f2a592010-04-20 14:13:34 +10001659 sector_t chunk_number;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660 unsigned int chunk_offset;
NeilBrown911d4ee2009-03-31 14:39:38 +11001661 int pd_idx, qd_idx;
NeilBrown67cc2b82009-03-31 14:39:38 +11001662 int ddf_layout = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 sector_t new_sector;
NeilBrowne183eae2009-03-31 15:20:22 +11001664 int algorithm = previous ? conf->prev_algo
1665 : conf->algorithm;
Andre Noll09c9e5f2009-06-18 08:45:55 +10001666 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1667 : conf->chunk_sectors;
NeilBrown112bf892009-03-31 14:39:38 +11001668 int raid_disks = previous ? conf->previous_raid_disks
1669 : conf->raid_disks;
1670 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671
1672 /* First compute the information on this sector */
1673
1674 /*
1675 * Compute the chunk number and the sector offset inside the chunk
1676 */
1677 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1678 chunk_number = r_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679
1680 /*
1681 * Compute the stripe number
1682 */
NeilBrown35f2a592010-04-20 14:13:34 +10001683 stripe = chunk_number;
1684 *dd_idx = sector_div(stripe, data_disks);
NeilBrown6e3b96e2010-04-23 07:08:28 +10001685 stripe2 = stripe;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 /*
1687 * Select the parity disk based on the user selected algorithm.
1688 */
NeilBrown911d4ee2009-03-31 14:39:38 +11001689 pd_idx = qd_idx = ~0;
NeilBrown16a53ec2006-06-26 00:27:38 -07001690 switch(conf->level) {
1691 case 4:
NeilBrown911d4ee2009-03-31 14:39:38 +11001692 pd_idx = data_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001693 break;
1694 case 5:
NeilBrowne183eae2009-03-31 15:20:22 +11001695 switch (algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696 case ALGORITHM_LEFT_ASYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001697 pd_idx = data_disks - sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001698 if (*dd_idx >= pd_idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 (*dd_idx)++;
1700 break;
1701 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001702 pd_idx = sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001703 if (*dd_idx >= pd_idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 (*dd_idx)++;
1705 break;
1706 case ALGORITHM_LEFT_SYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001707 pd_idx = data_disks - sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001708 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709 break;
1710 case ALGORITHM_RIGHT_SYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001711 pd_idx = sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001712 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001714 case ALGORITHM_PARITY_0:
1715 pd_idx = 0;
1716 (*dd_idx)++;
1717 break;
1718 case ALGORITHM_PARITY_N:
1719 pd_idx = data_disks;
1720 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721 default:
NeilBrown99c0fb52009-03-31 14:39:38 +11001722 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001723 }
1724 break;
1725 case 6:
1726
NeilBrowne183eae2009-03-31 15:20:22 +11001727 switch (algorithm) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001728 case ALGORITHM_LEFT_ASYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001729 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001730 qd_idx = pd_idx + 1;
1731 if (pd_idx == raid_disks-1) {
NeilBrown99c0fb52009-03-31 14:39:38 +11001732 (*dd_idx)++; /* Q D D D P */
NeilBrown911d4ee2009-03-31 14:39:38 +11001733 qd_idx = 0;
1734 } else if (*dd_idx >= pd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001735 (*dd_idx) += 2; /* D D P Q D */
1736 break;
1737 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001738 pd_idx = sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001739 qd_idx = pd_idx + 1;
1740 if (pd_idx == raid_disks-1) {
NeilBrown99c0fb52009-03-31 14:39:38 +11001741 (*dd_idx)++; /* Q D D D P */
NeilBrown911d4ee2009-03-31 14:39:38 +11001742 qd_idx = 0;
1743 } else if (*dd_idx >= pd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001744 (*dd_idx) += 2; /* D D P Q D */
1745 break;
1746 case ALGORITHM_LEFT_SYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001747 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001748 qd_idx = (pd_idx + 1) % raid_disks;
1749 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001750 break;
1751 case ALGORITHM_RIGHT_SYMMETRIC:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001752 pd_idx = sector_div(stripe2, raid_disks);
NeilBrown911d4ee2009-03-31 14:39:38 +11001753 qd_idx = (pd_idx + 1) % raid_disks;
1754 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
NeilBrown16a53ec2006-06-26 00:27:38 -07001755 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001756
1757 case ALGORITHM_PARITY_0:
1758 pd_idx = 0;
1759 qd_idx = 1;
1760 (*dd_idx) += 2;
1761 break;
1762 case ALGORITHM_PARITY_N:
1763 pd_idx = data_disks;
1764 qd_idx = data_disks + 1;
1765 break;
1766
1767 case ALGORITHM_ROTATING_ZERO_RESTART:
1768 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1769 * of blocks for computing Q is different.
1770 */
NeilBrown6e3b96e2010-04-23 07:08:28 +10001771 pd_idx = sector_div(stripe2, raid_disks);
NeilBrown99c0fb52009-03-31 14:39:38 +11001772 qd_idx = pd_idx + 1;
1773 if (pd_idx == raid_disks-1) {
1774 (*dd_idx)++; /* Q D D D P */
1775 qd_idx = 0;
1776 } else if (*dd_idx >= pd_idx)
1777 (*dd_idx) += 2; /* D D P Q D */
NeilBrown67cc2b82009-03-31 14:39:38 +11001778 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001779 break;
1780
1781 case ALGORITHM_ROTATING_N_RESTART:
1782 /* Same a left_asymmetric, by first stripe is
1783 * D D D P Q rather than
1784 * Q D D D P
1785 */
NeilBrown6e3b96e2010-04-23 07:08:28 +10001786 stripe2 += 1;
1787 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
NeilBrown99c0fb52009-03-31 14:39:38 +11001788 qd_idx = pd_idx + 1;
1789 if (pd_idx == raid_disks-1) {
1790 (*dd_idx)++; /* Q D D D P */
1791 qd_idx = 0;
1792 } else if (*dd_idx >= pd_idx)
1793 (*dd_idx) += 2; /* D D P Q D */
NeilBrown67cc2b82009-03-31 14:39:38 +11001794 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001795 break;
1796
1797 case ALGORITHM_ROTATING_N_CONTINUE:
1798 /* Same as left_symmetric but Q is before P */
NeilBrown6e3b96e2010-04-23 07:08:28 +10001799 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
NeilBrown99c0fb52009-03-31 14:39:38 +11001800 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1801 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
NeilBrown67cc2b82009-03-31 14:39:38 +11001802 ddf_layout = 1;
NeilBrown99c0fb52009-03-31 14:39:38 +11001803 break;
1804
1805 case ALGORITHM_LEFT_ASYMMETRIC_6:
1806 /* RAID5 left_asymmetric, with Q on last device */
NeilBrown6e3b96e2010-04-23 07:08:28 +10001807 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
NeilBrown99c0fb52009-03-31 14:39:38 +11001808 if (*dd_idx >= pd_idx)
1809 (*dd_idx)++;
1810 qd_idx = raid_disks - 1;
1811 break;
1812
1813 case ALGORITHM_RIGHT_ASYMMETRIC_6:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001814 pd_idx = sector_div(stripe2, raid_disks-1);
NeilBrown99c0fb52009-03-31 14:39:38 +11001815 if (*dd_idx >= pd_idx)
1816 (*dd_idx)++;
1817 qd_idx = raid_disks - 1;
1818 break;
1819
1820 case ALGORITHM_LEFT_SYMMETRIC_6:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001821 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
NeilBrown99c0fb52009-03-31 14:39:38 +11001822 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1823 qd_idx = raid_disks - 1;
1824 break;
1825
1826 case ALGORITHM_RIGHT_SYMMETRIC_6:
NeilBrown6e3b96e2010-04-23 07:08:28 +10001827 pd_idx = sector_div(stripe2, raid_disks-1);
NeilBrown99c0fb52009-03-31 14:39:38 +11001828 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1829 qd_idx = raid_disks - 1;
1830 break;
1831
1832 case ALGORITHM_PARITY_0_6:
1833 pd_idx = 0;
1834 (*dd_idx)++;
1835 qd_idx = raid_disks - 1;
1836 break;
1837
NeilBrown16a53ec2006-06-26 00:27:38 -07001838 default:
NeilBrown99c0fb52009-03-31 14:39:38 +11001839 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001840 }
1841 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 }
1843
NeilBrown911d4ee2009-03-31 14:39:38 +11001844 if (sh) {
1845 sh->pd_idx = pd_idx;
1846 sh->qd_idx = qd_idx;
NeilBrown67cc2b82009-03-31 14:39:38 +11001847 sh->ddf_layout = ddf_layout;
NeilBrown911d4ee2009-03-31 14:39:38 +11001848 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 /*
1850 * Finally, compute the new sector number
1851 */
1852 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1853 return new_sector;
1854}
1855
1856
NeilBrown784052e2009-03-31 15:19:07 +11001857static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858{
1859 raid5_conf_t *conf = sh->raid_conf;
NeilBrownb875e532006-12-10 02:20:49 -08001860 int raid_disks = sh->disks;
1861 int data_disks = raid_disks - conf->max_degraded;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001862 sector_t new_sector = sh->sector, check;
Andre Noll09c9e5f2009-06-18 08:45:55 +10001863 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1864 : conf->chunk_sectors;
NeilBrowne183eae2009-03-31 15:20:22 +11001865 int algorithm = previous ? conf->prev_algo
1866 : conf->algorithm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001867 sector_t stripe;
1868 int chunk_offset;
NeilBrown35f2a592010-04-20 14:13:34 +10001869 sector_t chunk_number;
1870 int dummy1, dd_idx = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871 sector_t r_sector;
NeilBrown911d4ee2009-03-31 14:39:38 +11001872 struct stripe_head sh2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873
NeilBrown16a53ec2006-06-26 00:27:38 -07001874
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1876 stripe = new_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877
NeilBrown16a53ec2006-06-26 00:27:38 -07001878 if (i == sh->pd_idx)
1879 return 0;
1880 switch(conf->level) {
1881 case 4: break;
1882 case 5:
NeilBrowne183eae2009-03-31 15:20:22 +11001883 switch (algorithm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884 case ALGORITHM_LEFT_ASYMMETRIC:
1885 case ALGORITHM_RIGHT_ASYMMETRIC:
1886 if (i > sh->pd_idx)
1887 i--;
1888 break;
1889 case ALGORITHM_LEFT_SYMMETRIC:
1890 case ALGORITHM_RIGHT_SYMMETRIC:
1891 if (i < sh->pd_idx)
1892 i += raid_disks;
1893 i -= (sh->pd_idx + 1);
1894 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001895 case ALGORITHM_PARITY_0:
1896 i -= 1;
1897 break;
1898 case ALGORITHM_PARITY_N:
1899 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 default:
NeilBrown99c0fb52009-03-31 14:39:38 +11001901 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001902 }
1903 break;
1904 case 6:
NeilBrownd0dabf72009-03-31 14:39:38 +11001905 if (i == sh->qd_idx)
NeilBrown16a53ec2006-06-26 00:27:38 -07001906 return 0; /* It is the Q disk */
NeilBrowne183eae2009-03-31 15:20:22 +11001907 switch (algorithm) {
NeilBrown16a53ec2006-06-26 00:27:38 -07001908 case ALGORITHM_LEFT_ASYMMETRIC:
1909 case ALGORITHM_RIGHT_ASYMMETRIC:
NeilBrown99c0fb52009-03-31 14:39:38 +11001910 case ALGORITHM_ROTATING_ZERO_RESTART:
1911 case ALGORITHM_ROTATING_N_RESTART:
1912 if (sh->pd_idx == raid_disks-1)
1913 i--; /* Q D D D P */
NeilBrown16a53ec2006-06-26 00:27:38 -07001914 else if (i > sh->pd_idx)
1915 i -= 2; /* D D P Q D */
1916 break;
1917 case ALGORITHM_LEFT_SYMMETRIC:
1918 case ALGORITHM_RIGHT_SYMMETRIC:
1919 if (sh->pd_idx == raid_disks-1)
1920 i--; /* Q D D D P */
1921 else {
1922 /* D D P Q D */
1923 if (i < sh->pd_idx)
1924 i += raid_disks;
1925 i -= (sh->pd_idx + 2);
1926 }
1927 break;
NeilBrown99c0fb52009-03-31 14:39:38 +11001928 case ALGORITHM_PARITY_0:
1929 i -= 2;
1930 break;
1931 case ALGORITHM_PARITY_N:
1932 break;
1933 case ALGORITHM_ROTATING_N_CONTINUE:
NeilBrowne4424fe2009-10-16 16:27:34 +11001934 /* Like left_symmetric, but P is before Q */
NeilBrown99c0fb52009-03-31 14:39:38 +11001935 if (sh->pd_idx == 0)
1936 i--; /* P D D D Q */
NeilBrowne4424fe2009-10-16 16:27:34 +11001937 else {
1938 /* D D Q P D */
1939 if (i < sh->pd_idx)
1940 i += raid_disks;
1941 i -= (sh->pd_idx + 1);
1942 }
NeilBrown99c0fb52009-03-31 14:39:38 +11001943 break;
1944 case ALGORITHM_LEFT_ASYMMETRIC_6:
1945 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1946 if (i > sh->pd_idx)
1947 i--;
1948 break;
1949 case ALGORITHM_LEFT_SYMMETRIC_6:
1950 case ALGORITHM_RIGHT_SYMMETRIC_6:
1951 if (i < sh->pd_idx)
1952 i += data_disks + 1;
1953 i -= (sh->pd_idx + 1);
1954 break;
1955 case ALGORITHM_PARITY_0_6:
1956 i -= 1;
1957 break;
NeilBrown16a53ec2006-06-26 00:27:38 -07001958 default:
NeilBrown99c0fb52009-03-31 14:39:38 +11001959 BUG();
NeilBrown16a53ec2006-06-26 00:27:38 -07001960 }
1961 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001962 }
1963
1964 chunk_number = stripe * data_disks + i;
NeilBrown35f2a592010-04-20 14:13:34 +10001965 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001966
NeilBrown112bf892009-03-31 14:39:38 +11001967 check = raid5_compute_sector(conf, r_sector,
NeilBrown784052e2009-03-31 15:19:07 +11001968 previous, &dummy1, &sh2);
NeilBrown911d4ee2009-03-31 14:39:38 +11001969 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
1970 || sh2.qd_idx != sh->qd_idx) {
NeilBrown0c55e022010-05-03 14:09:02 +10001971 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
1972 mdname(conf->mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973 return 0;
1974 }
1975 return r_sector;
1976}
1977
1978
Dan Williams600aa102008-06-28 08:32:05 +10001979static void
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07001980schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
Dan Williams600aa102008-06-28 08:32:05 +10001981 int rcw, int expand)
Dan Williamse33129d2007-01-02 13:52:30 -07001982{
1983 int i, pd_idx = sh->pd_idx, disks = sh->disks;
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07001984 raid5_conf_t *conf = sh->raid_conf;
1985 int level = conf->level;
NeilBrown16a53ec2006-06-26 00:27:38 -07001986
Dan Williamse33129d2007-01-02 13:52:30 -07001987 if (rcw) {
1988 /* if we are not expanding this is a proper write request, and
1989 * there will be bios with new data to be drained into the
1990 * stripe cache
1991 */
1992 if (!expand) {
Dan Williams600aa102008-06-28 08:32:05 +10001993 sh->reconstruct_state = reconstruct_state_drain_run;
1994 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
1995 } else
1996 sh->reconstruct_state = reconstruct_state_run;
Dan Williamse33129d2007-01-02 13:52:30 -07001997
Dan Williamsac6b53b2009-07-14 13:40:19 -07001998 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07001999
2000 for (i = disks; i--; ) {
2001 struct r5dev *dev = &sh->dev[i];
2002
2003 if (dev->towrite) {
2004 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsd8ee0722008-06-28 08:32:06 +10002005 set_bit(R5_Wantdrain, &dev->flags);
Dan Williamse33129d2007-01-02 13:52:30 -07002006 if (!expand)
2007 clear_bit(R5_UPTODATE, &dev->flags);
Dan Williams600aa102008-06-28 08:32:05 +10002008 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07002009 }
2010 }
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002011 if (s->locked + conf->max_degraded == disks)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002012 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002013 atomic_inc(&conf->pending_full_writes);
Dan Williamse33129d2007-01-02 13:52:30 -07002014 } else {
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002015 BUG_ON(level == 6);
Dan Williamse33129d2007-01-02 13:52:30 -07002016 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2017 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2018
Dan Williamsd8ee0722008-06-28 08:32:06 +10002019 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
Dan Williams600aa102008-06-28 08:32:05 +10002020 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2021 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
Dan Williamsac6b53b2009-07-14 13:40:19 -07002022 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07002023
2024 for (i = disks; i--; ) {
2025 struct r5dev *dev = &sh->dev[i];
2026 if (i == pd_idx)
2027 continue;
2028
Dan Williamse33129d2007-01-02 13:52:30 -07002029 if (dev->towrite &&
2030 (test_bit(R5_UPTODATE, &dev->flags) ||
Dan Williamsd8ee0722008-06-28 08:32:06 +10002031 test_bit(R5_Wantcompute, &dev->flags))) {
2032 set_bit(R5_Wantdrain, &dev->flags);
Dan Williamse33129d2007-01-02 13:52:30 -07002033 set_bit(R5_LOCKED, &dev->flags);
2034 clear_bit(R5_UPTODATE, &dev->flags);
Dan Williams600aa102008-06-28 08:32:05 +10002035 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07002036 }
2037 }
2038 }
2039
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002040 /* keep the parity disk(s) locked while asynchronous operations
Dan Williamse33129d2007-01-02 13:52:30 -07002041 * are in flight
2042 */
2043 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2044 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
Dan Williams600aa102008-06-28 08:32:05 +10002045 s->locked++;
Dan Williamse33129d2007-01-02 13:52:30 -07002046
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002047 if (level == 6) {
2048 int qd_idx = sh->qd_idx;
2049 struct r5dev *dev = &sh->dev[qd_idx];
2050
2051 set_bit(R5_LOCKED, &dev->flags);
2052 clear_bit(R5_UPTODATE, &dev->flags);
2053 s->locked++;
2054 }
2055
Dan Williams600aa102008-06-28 08:32:05 +10002056 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
Harvey Harrisone46b2722008-04-28 02:15:50 -07002057 __func__, (unsigned long long)sh->sector,
Dan Williams600aa102008-06-28 08:32:05 +10002058 s->locked, s->ops_request);
Dan Williamse33129d2007-01-02 13:52:30 -07002059}
NeilBrown16a53ec2006-06-26 00:27:38 -07002060
Linus Torvalds1da177e2005-04-16 15:20:36 -07002061/*
2062 * Each stripe/dev can have one or more bion attached.
NeilBrown16a53ec2006-06-26 00:27:38 -07002063 * toread/towrite point to the first in a chain.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002064 * The bi_next chain must be in order.
2065 */
2066static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2067{
2068 struct bio **bip;
2069 raid5_conf_t *conf = sh->raid_conf;
NeilBrown72626682005-09-09 16:23:54 -07002070 int firstwrite=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002071
Dan Williams45b42332007-07-09 11:56:43 -07002072 pr_debug("adding bh b#%llu to stripe s#%llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 (unsigned long long)bi->bi_sector,
2074 (unsigned long long)sh->sector);
2075
2076
2077 spin_lock(&sh->lock);
2078 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07002079 if (forwrite) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002080 bip = &sh->dev[dd_idx].towrite;
NeilBrown72626682005-09-09 16:23:54 -07002081 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
2082 firstwrite = 1;
2083 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002084 bip = &sh->dev[dd_idx].toread;
2085 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2086 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
2087 goto overlap;
2088 bip = & (*bip)->bi_next;
2089 }
2090 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
2091 goto overlap;
2092
Eric Sesterhenn78bafeb2006-04-02 13:31:42 +02002093 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094 if (*bip)
2095 bi->bi_next = *bip;
2096 *bip = bi;
Jens Axboe960e7392008-08-15 10:41:18 +02002097 bi->bi_phys_segments++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098 spin_unlock_irq(&conf->device_lock);
2099 spin_unlock(&sh->lock);
2100
Dan Williams45b42332007-07-09 11:56:43 -07002101 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002102 (unsigned long long)bi->bi_sector,
2103 (unsigned long long)sh->sector, dd_idx);
2104
NeilBrown72626682005-09-09 16:23:54 -07002105 if (conf->mddev->bitmap && firstwrite) {
NeilBrown72626682005-09-09 16:23:54 -07002106 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2107 STRIPE_SECTORS, 0);
NeilBrownae3c20c2006-07-10 04:44:17 -07002108 sh->bm_seq = conf->seq_flush+1;
NeilBrown72626682005-09-09 16:23:54 -07002109 set_bit(STRIPE_BIT_DELAY, &sh->state);
2110 }
2111
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112 if (forwrite) {
2113 /* check if page is covered */
2114 sector_t sector = sh->dev[dd_idx].sector;
2115 for (bi=sh->dev[dd_idx].towrite;
2116 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2117 bi && bi->bi_sector <= sector;
2118 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2119 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
2120 sector = bi->bi_sector + (bi->bi_size>>9);
2121 }
2122 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2123 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2124 }
2125 return 1;
2126
2127 overlap:
2128 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2129 spin_unlock_irq(&conf->device_lock);
2130 spin_unlock(&sh->lock);
2131 return 0;
2132}
2133
NeilBrown29269552006-03-27 01:18:10 -08002134static void end_reshape(raid5_conf_t *conf);
2135
NeilBrown911d4ee2009-03-31 14:39:38 +11002136static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
2137 struct stripe_head *sh)
NeilBrownccfcc3c2006-03-27 01:18:09 -08002138{
NeilBrown784052e2009-03-31 15:19:07 +11002139 int sectors_per_chunk =
Andre Noll09c9e5f2009-06-18 08:45:55 +10002140 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
NeilBrown911d4ee2009-03-31 14:39:38 +11002141 int dd_idx;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002142 int chunk_offset = sector_div(stripe, sectors_per_chunk);
NeilBrown112bf892009-03-31 14:39:38 +11002143 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
Coywolf Qi Hunt2d2063c2006-10-03 01:15:50 -07002144
NeilBrown112bf892009-03-31 14:39:38 +11002145 raid5_compute_sector(conf,
2146 stripe * (disks - conf->max_degraded)
NeilBrownb875e532006-12-10 02:20:49 -08002147 *sectors_per_chunk + chunk_offset,
NeilBrown112bf892009-03-31 14:39:38 +11002148 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11002149 &dd_idx, sh);
NeilBrownccfcc3c2006-03-27 01:18:09 -08002150}
2151
Dan Williamsa4456852007-07-09 11:56:43 -07002152static void
Dan Williams1fe797e2008-06-28 09:16:30 +10002153handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002154 struct stripe_head_state *s, int disks,
2155 struct bio **return_bi)
2156{
2157 int i;
2158 for (i = disks; i--; ) {
2159 struct bio *bi;
2160 int bitmap_end = 0;
2161
2162 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2163 mdk_rdev_t *rdev;
2164 rcu_read_lock();
2165 rdev = rcu_dereference(conf->disks[i].rdev);
2166 if (rdev && test_bit(In_sync, &rdev->flags))
2167 /* multiple read failures in one stripe */
2168 md_error(conf->mddev, rdev);
2169 rcu_read_unlock();
2170 }
2171 spin_lock_irq(&conf->device_lock);
2172 /* fail all writes first */
2173 bi = sh->dev[i].towrite;
2174 sh->dev[i].towrite = NULL;
2175 if (bi) {
2176 s->to_write--;
2177 bitmap_end = 1;
2178 }
2179
2180 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2181 wake_up(&conf->wait_for_overlap);
2182
2183 while (bi && bi->bi_sector <
2184 sh->dev[i].sector + STRIPE_SECTORS) {
2185 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2186 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002187 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002188 md_write_end(conf->mddev);
2189 bi->bi_next = *return_bi;
2190 *return_bi = bi;
2191 }
2192 bi = nextbi;
2193 }
2194 /* and fail all 'written' */
2195 bi = sh->dev[i].written;
2196 sh->dev[i].written = NULL;
2197 if (bi) bitmap_end = 1;
2198 while (bi && bi->bi_sector <
2199 sh->dev[i].sector + STRIPE_SECTORS) {
2200 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2201 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002202 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002203 md_write_end(conf->mddev);
2204 bi->bi_next = *return_bi;
2205 *return_bi = bi;
2206 }
2207 bi = bi2;
2208 }
2209
Dan Williamsb5e98d62007-01-02 13:52:31 -07002210 /* fail any reads if this device is non-operational and
2211 * the data has not reached the cache yet.
2212 */
2213 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2214 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2215 test_bit(R5_ReadError, &sh->dev[i].flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002216 bi = sh->dev[i].toread;
2217 sh->dev[i].toread = NULL;
2218 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2219 wake_up(&conf->wait_for_overlap);
2220 if (bi) s->to_read--;
2221 while (bi && bi->bi_sector <
2222 sh->dev[i].sector + STRIPE_SECTORS) {
2223 struct bio *nextbi =
2224 r5_next_bio(bi, sh->dev[i].sector);
2225 clear_bit(BIO_UPTODATE, &bi->bi_flags);
Jens Axboe960e7392008-08-15 10:41:18 +02002226 if (!raid5_dec_bi_phys_segments(bi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002227 bi->bi_next = *return_bi;
2228 *return_bi = bi;
2229 }
2230 bi = nextbi;
2231 }
2232 }
2233 spin_unlock_irq(&conf->device_lock);
2234 if (bitmap_end)
2235 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2236 STRIPE_SECTORS, 0, 0);
2237 }
2238
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002239 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2240 if (atomic_dec_and_test(&conf->pending_full_writes))
2241 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002242}
2243
Dan Williams1fe797e2008-06-28 09:16:30 +10002244/* fetch_block5 - checks the given member device to see if its data needs
2245 * to be read or computed to satisfy a request.
2246 *
2247 * Returns 1 when no more member devices need to be checked, otherwise returns
2248 * 0 to tell the loop in handle_stripe_fill5 to continue
Dan Williamsf38e1212007-01-02 13:52:30 -07002249 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002250static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2251 int disk_idx, int disks)
Dan Williamsf38e1212007-01-02 13:52:30 -07002252{
2253 struct r5dev *dev = &sh->dev[disk_idx];
2254 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2255
Dan Williamsf38e1212007-01-02 13:52:30 -07002256 /* is the data in this block needed, and can we get it? */
2257 if (!test_bit(R5_LOCKED, &dev->flags) &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002258 !test_bit(R5_UPTODATE, &dev->flags) &&
2259 (dev->toread ||
2260 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2261 s->syncing || s->expanding ||
2262 (s->failed &&
2263 (failed_dev->toread ||
2264 (failed_dev->towrite &&
2265 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002266 /* We would like to get this block, possibly by computing it,
2267 * otherwise read it if the backing disk is insync
Dan Williamsf38e1212007-01-02 13:52:30 -07002268 */
2269 if ((s->uptodate == disks - 1) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10002270 (s->failed && disk_idx == s->failed_num)) {
Dan Williams976ea8d2008-06-28 08:32:03 +10002271 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2272 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
Dan Williamsf38e1212007-01-02 13:52:30 -07002273 set_bit(R5_Wantcompute, &dev->flags);
2274 sh->ops.target = disk_idx;
Dan Williamsac6b53b2009-07-14 13:40:19 -07002275 sh->ops.target2 = -1;
Dan Williamsf38e1212007-01-02 13:52:30 -07002276 s->req_compute = 1;
Dan Williamsf38e1212007-01-02 13:52:30 -07002277 /* Careful: from this point on 'uptodate' is in the eye
Dan Williamsac6b53b2009-07-14 13:40:19 -07002278 * of raid_run_ops which services 'compute' operations
Dan Williamsf38e1212007-01-02 13:52:30 -07002279 * before writes. R5_Wantcompute flags a block that will
2280 * be R5_UPTODATE by the time it is needed for a
2281 * subsequent operation.
2282 */
2283 s->uptodate++;
Dan Williams1fe797e2008-06-28 09:16:30 +10002284 return 1; /* uptodate + compute == disks */
Dan Williams7a1fc532008-07-10 04:54:57 -07002285 } else if (test_bit(R5_Insync, &dev->flags)) {
Dan Williamsf38e1212007-01-02 13:52:30 -07002286 set_bit(R5_LOCKED, &dev->flags);
2287 set_bit(R5_Wantread, &dev->flags);
Dan Williamsf38e1212007-01-02 13:52:30 -07002288 s->locked++;
2289 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2290 s->syncing);
2291 }
2292 }
2293
Dan Williams1fe797e2008-06-28 09:16:30 +10002294 return 0;
Dan Williamsf38e1212007-01-02 13:52:30 -07002295}
2296
Dan Williams1fe797e2008-06-28 09:16:30 +10002297/**
2298 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2299 */
2300static void handle_stripe_fill5(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002301 struct stripe_head_state *s, int disks)
2302{
2303 int i;
Dan Williamsf38e1212007-01-02 13:52:30 -07002304
Dan Williamsf38e1212007-01-02 13:52:30 -07002305 /* look for blocks to read/compute, skip this if a compute
2306 * is already in flight, or if the stripe contents are in the
2307 * midst of changing due to a write
2308 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002309 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
Dan Williams1fe797e2008-06-28 09:16:30 +10002310 !sh->reconstruct_state)
Dan Williamsf38e1212007-01-02 13:52:30 -07002311 for (i = disks; i--; )
Dan Williams1fe797e2008-06-28 09:16:30 +10002312 if (fetch_block5(sh, s, i, disks))
Dan Williamsf38e1212007-01-02 13:52:30 -07002313 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002314 set_bit(STRIPE_HANDLE, &sh->state);
2315}
2316
Yuri Tikhonov5599bec2009-08-29 19:13:12 -07002317/* fetch_block6 - checks the given member device to see if its data needs
2318 * to be read or computed to satisfy a request.
2319 *
2320 * Returns 1 when no more member devices need to be checked, otherwise returns
2321 * 0 to tell the loop in handle_stripe_fill6 to continue
2322 */
2323static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
2324 struct r6_state *r6s, int disk_idx, int disks)
2325{
2326 struct r5dev *dev = &sh->dev[disk_idx];
2327 struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]],
2328 &sh->dev[r6s->failed_num[1]] };
2329
2330 if (!test_bit(R5_LOCKED, &dev->flags) &&
2331 !test_bit(R5_UPTODATE, &dev->flags) &&
2332 (dev->toread ||
2333 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2334 s->syncing || s->expanding ||
2335 (s->failed >= 1 &&
2336 (fdev[0]->toread || s->to_write)) ||
2337 (s->failed >= 2 &&
2338 (fdev[1]->toread || s->to_write)))) {
2339 /* we would like to get this block, possibly by computing it,
2340 * otherwise read it if the backing disk is insync
2341 */
2342 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2343 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2344 if ((s->uptodate == disks - 1) &&
2345 (s->failed && (disk_idx == r6s->failed_num[0] ||
2346 disk_idx == r6s->failed_num[1]))) {
2347 /* have disk failed, and we're requested to fetch it;
2348 * do compute it
2349 */
2350 pr_debug("Computing stripe %llu block %d\n",
2351 (unsigned long long)sh->sector, disk_idx);
2352 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2353 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2354 set_bit(R5_Wantcompute, &dev->flags);
2355 sh->ops.target = disk_idx;
2356 sh->ops.target2 = -1; /* no 2nd target */
2357 s->req_compute = 1;
2358 s->uptodate++;
2359 return 1;
2360 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2361 /* Computing 2-failure is *very* expensive; only
2362 * do it if failed >= 2
2363 */
2364 int other;
2365 for (other = disks; other--; ) {
2366 if (other == disk_idx)
2367 continue;
2368 if (!test_bit(R5_UPTODATE,
2369 &sh->dev[other].flags))
2370 break;
2371 }
2372 BUG_ON(other < 0);
2373 pr_debug("Computing stripe %llu blocks %d,%d\n",
2374 (unsigned long long)sh->sector,
2375 disk_idx, other);
2376 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2377 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2378 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2379 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2380 sh->ops.target = disk_idx;
2381 sh->ops.target2 = other;
2382 s->uptodate += 2;
2383 s->req_compute = 1;
2384 return 1;
2385 } else if (test_bit(R5_Insync, &dev->flags)) {
2386 set_bit(R5_LOCKED, &dev->flags);
2387 set_bit(R5_Wantread, &dev->flags);
2388 s->locked++;
2389 pr_debug("Reading block %d (sync=%d)\n",
2390 disk_idx, s->syncing);
2391 }
2392 }
2393
2394 return 0;
2395}
2396
2397/**
2398 * handle_stripe_fill6 - read or compute data to satisfy pending requests.
2399 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002400static void handle_stripe_fill6(struct stripe_head *sh,
Dan Williamsa4456852007-07-09 11:56:43 -07002401 struct stripe_head_state *s, struct r6_state *r6s,
2402 int disks)
2403{
2404 int i;
Yuri Tikhonov5599bec2009-08-29 19:13:12 -07002405
2406 /* look for blocks to read/compute, skip this if a compute
2407 * is already in flight, or if the stripe contents are in the
2408 * midst of changing due to a write
2409 */
2410 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2411 !sh->reconstruct_state)
2412 for (i = disks; i--; )
2413 if (fetch_block6(sh, s, r6s, i, disks))
2414 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002415 set_bit(STRIPE_HANDLE, &sh->state);
2416}
2417
2418
Dan Williams1fe797e2008-06-28 09:16:30 +10002419/* handle_stripe_clean_event
Dan Williamsa4456852007-07-09 11:56:43 -07002420 * any written block on an uptodate or failed drive can be returned.
2421 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2422 * never LOCKED, so we don't need to test 'failed' directly.
2423 */
Dan Williams1fe797e2008-06-28 09:16:30 +10002424static void handle_stripe_clean_event(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002425 struct stripe_head *sh, int disks, struct bio **return_bi)
2426{
2427 int i;
2428 struct r5dev *dev;
2429
2430 for (i = disks; i--; )
2431 if (sh->dev[i].written) {
2432 dev = &sh->dev[i];
2433 if (!test_bit(R5_LOCKED, &dev->flags) &&
2434 test_bit(R5_UPTODATE, &dev->flags)) {
2435 /* We can return any write requests */
2436 struct bio *wbi, *wbi2;
2437 int bitmap_end = 0;
Dan Williams45b42332007-07-09 11:56:43 -07002438 pr_debug("Return write for disc %d\n", i);
Dan Williamsa4456852007-07-09 11:56:43 -07002439 spin_lock_irq(&conf->device_lock);
2440 wbi = dev->written;
2441 dev->written = NULL;
2442 while (wbi && wbi->bi_sector <
2443 dev->sector + STRIPE_SECTORS) {
2444 wbi2 = r5_next_bio(wbi, dev->sector);
Jens Axboe960e7392008-08-15 10:41:18 +02002445 if (!raid5_dec_bi_phys_segments(wbi)) {
Dan Williamsa4456852007-07-09 11:56:43 -07002446 md_write_end(conf->mddev);
2447 wbi->bi_next = *return_bi;
2448 *return_bi = wbi;
2449 }
2450 wbi = wbi2;
2451 }
2452 if (dev->towrite == NULL)
2453 bitmap_end = 1;
2454 spin_unlock_irq(&conf->device_lock);
2455 if (bitmap_end)
2456 bitmap_endwrite(conf->mddev->bitmap,
2457 sh->sector,
2458 STRIPE_SECTORS,
2459 !test_bit(STRIPE_DEGRADED, &sh->state),
2460 0);
2461 }
2462 }
Dan Williams8b3e6cd2008-04-28 02:15:53 -07002463
2464 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2465 if (atomic_dec_and_test(&conf->pending_full_writes))
2466 md_wakeup_thread(conf->mddev->thread);
Dan Williamsa4456852007-07-09 11:56:43 -07002467}
2468
Dan Williams1fe797e2008-06-28 09:16:30 +10002469static void handle_stripe_dirtying5(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002470 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2471{
2472 int rmw = 0, rcw = 0, i;
2473 for (i = disks; i--; ) {
2474 /* would I have to read this buffer for read_modify_write */
2475 struct r5dev *dev = &sh->dev[i];
2476 if ((dev->towrite || i == sh->pd_idx) &&
2477 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002478 !(test_bit(R5_UPTODATE, &dev->flags) ||
2479 test_bit(R5_Wantcompute, &dev->flags))) {
Dan Williamsa4456852007-07-09 11:56:43 -07002480 if (test_bit(R5_Insync, &dev->flags))
2481 rmw++;
2482 else
2483 rmw += 2*disks; /* cannot read it */
2484 }
2485 /* Would I have to read this buffer for reconstruct_write */
2486 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2487 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002488 !(test_bit(R5_UPTODATE, &dev->flags) ||
2489 test_bit(R5_Wantcompute, &dev->flags))) {
2490 if (test_bit(R5_Insync, &dev->flags)) rcw++;
Dan Williamsa4456852007-07-09 11:56:43 -07002491 else
2492 rcw += 2*disks;
2493 }
2494 }
Dan Williams45b42332007-07-09 11:56:43 -07002495 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07002496 (unsigned long long)sh->sector, rmw, rcw);
2497 set_bit(STRIPE_HANDLE, &sh->state);
2498 if (rmw < rcw && rmw > 0)
2499 /* prefer read-modify-write, but need to get some data */
2500 for (i = disks; i--; ) {
2501 struct r5dev *dev = &sh->dev[i];
2502 if ((dev->towrite || i == sh->pd_idx) &&
2503 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002504 !(test_bit(R5_UPTODATE, &dev->flags) ||
2505 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002506 test_bit(R5_Insync, &dev->flags)) {
2507 if (
2508 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002509 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002510 "%d for r-m-w\n", i);
2511 set_bit(R5_LOCKED, &dev->flags);
2512 set_bit(R5_Wantread, &dev->flags);
2513 s->locked++;
2514 } else {
2515 set_bit(STRIPE_DELAYED, &sh->state);
2516 set_bit(STRIPE_HANDLE, &sh->state);
2517 }
2518 }
2519 }
2520 if (rcw <= rmw && rcw > 0)
2521 /* want reconstruct write, but need to get some data */
2522 for (i = disks; i--; ) {
2523 struct r5dev *dev = &sh->dev[i];
2524 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2525 i != sh->pd_idx &&
2526 !test_bit(R5_LOCKED, &dev->flags) &&
Dan Williamsf38e1212007-01-02 13:52:30 -07002527 !(test_bit(R5_UPTODATE, &dev->flags) ||
2528 test_bit(R5_Wantcompute, &dev->flags)) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002529 test_bit(R5_Insync, &dev->flags)) {
2530 if (
2531 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
Dan Williams45b42332007-07-09 11:56:43 -07002532 pr_debug("Read_old block "
Dan Williamsa4456852007-07-09 11:56:43 -07002533 "%d for Reconstruct\n", i);
2534 set_bit(R5_LOCKED, &dev->flags);
2535 set_bit(R5_Wantread, &dev->flags);
2536 s->locked++;
2537 } else {
2538 set_bit(STRIPE_DELAYED, &sh->state);
2539 set_bit(STRIPE_HANDLE, &sh->state);
2540 }
2541 }
2542 }
2543 /* now if nothing is locked, and if we have enough data,
2544 * we can start a write request
2545 */
Dan Williamsf38e1212007-01-02 13:52:30 -07002546 /* since handle_stripe can be called at any time we need to handle the
2547 * case where a compute block operation has been submitted and then a
Dan Williamsac6b53b2009-07-14 13:40:19 -07002548 * subsequent call wants to start a write request. raid_run_ops only
2549 * handles the case where compute block and reconstruct are requested
Dan Williamsf38e1212007-01-02 13:52:30 -07002550 * simultaneously. If this is not the case then new writes need to be
2551 * held off until the compute completes.
2552 */
Dan Williams976ea8d2008-06-28 08:32:03 +10002553 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2554 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2555 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07002556 schedule_reconstruction(sh, s, rcw == 0, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002557}
2558
Dan Williams1fe797e2008-06-28 09:16:30 +10002559static void handle_stripe_dirtying6(raid5_conf_t *conf,
Dan Williamsa4456852007-07-09 11:56:43 -07002560 struct stripe_head *sh, struct stripe_head_state *s,
2561 struct r6_state *r6s, int disks)
2562{
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07002563 int rcw = 0, pd_idx = sh->pd_idx, i;
NeilBrown34e04e82009-03-31 15:10:16 +11002564 int qd_idx = sh->qd_idx;
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07002565
2566 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002567 for (i = disks; i--; ) {
2568 struct r5dev *dev = &sh->dev[i];
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07002569 /* check if we haven't enough data */
2570 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2571 i != pd_idx && i != qd_idx &&
2572 !test_bit(R5_LOCKED, &dev->flags) &&
2573 !(test_bit(R5_UPTODATE, &dev->flags) ||
2574 test_bit(R5_Wantcompute, &dev->flags))) {
2575 rcw++;
2576 if (!test_bit(R5_Insync, &dev->flags))
2577 continue; /* it's a failed drive */
2578
2579 if (
2580 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2581 pr_debug("Read_old stripe %llu "
2582 "block %d for Reconstruct\n",
2583 (unsigned long long)sh->sector, i);
2584 set_bit(R5_LOCKED, &dev->flags);
2585 set_bit(R5_Wantread, &dev->flags);
2586 s->locked++;
2587 } else {
2588 pr_debug("Request delayed stripe %llu "
2589 "block %d for Reconstruct\n",
2590 (unsigned long long)sh->sector, i);
2591 set_bit(STRIPE_DELAYED, &sh->state);
2592 set_bit(STRIPE_HANDLE, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002593 }
2594 }
2595 }
Dan Williamsa4456852007-07-09 11:56:43 -07002596 /* now if nothing is locked, and if we have enough data, we can start a
2597 * write request
2598 */
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07002599 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2600 s->locked == 0 && rcw == 0 &&
Dan Williamsa4456852007-07-09 11:56:43 -07002601 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07002602 schedule_reconstruction(sh, s, 1, 0);
Dan Williamsa4456852007-07-09 11:56:43 -07002603 }
2604}
2605
2606static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2607 struct stripe_head_state *s, int disks)
2608{
Dan Williamsecc65c92008-06-28 08:31:57 +10002609 struct r5dev *dev = NULL;
Dan Williamse89f8962007-01-02 13:52:31 -07002610
Dan Williamsbd2ab672008-04-10 21:29:27 -07002611 set_bit(STRIPE_HANDLE, &sh->state);
2612
Dan Williamsecc65c92008-06-28 08:31:57 +10002613 switch (sh->check_state) {
2614 case check_state_idle:
2615 /* start a new check operation if there are no failures */
Dan Williamsbd2ab672008-04-10 21:29:27 -07002616 if (s->failed == 0) {
Dan Williamsbd2ab672008-04-10 21:29:27 -07002617 BUG_ON(s->uptodate != disks);
Dan Williamsecc65c92008-06-28 08:31:57 +10002618 sh->check_state = check_state_run;
2619 set_bit(STRIPE_OP_CHECK, &s->ops_request);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002620 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
Dan Williamsbd2ab672008-04-10 21:29:27 -07002621 s->uptodate--;
Dan Williamsecc65c92008-06-28 08:31:57 +10002622 break;
Dan Williamsbd2ab672008-04-10 21:29:27 -07002623 }
Dan Williamsa4456852007-07-09 11:56:43 -07002624 dev = &sh->dev[s->failed_num];
Dan Williamsecc65c92008-06-28 08:31:57 +10002625 /* fall through */
2626 case check_state_compute_result:
2627 sh->check_state = check_state_idle;
2628 if (!dev)
2629 dev = &sh->dev[sh->pd_idx];
2630
2631 /* check that a write has not made the stripe insync */
2632 if (test_bit(STRIPE_INSYNC, &sh->state))
2633 break;
2634
2635 /* either failed parity check, or recovery is happening */
Dan Williamsa4456852007-07-09 11:56:43 -07002636 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2637 BUG_ON(s->uptodate != disks);
2638
2639 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsecc65c92008-06-28 08:31:57 +10002640 s->locked++;
Dan Williamsa4456852007-07-09 11:56:43 -07002641 set_bit(R5_Wantwrite, &dev->flags);
Dan Williams830ea012007-01-02 13:52:31 -07002642
Dan Williamsa4456852007-07-09 11:56:43 -07002643 clear_bit(STRIPE_DEGRADED, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07002644 set_bit(STRIPE_INSYNC, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002645 break;
2646 case check_state_run:
2647 break; /* we will be called again upon completion */
2648 case check_state_check_result:
2649 sh->check_state = check_state_idle;
2650
2651 /* if a failure occurred during the check operation, leave
2652 * STRIPE_INSYNC not set and let the stripe be handled again
2653 */
2654 if (s->failed)
2655 break;
2656
2657 /* handle a successful check operation, if parity is correct
2658 * we are done. Otherwise update the mismatch count and repair
2659 * parity if !MD_RECOVERY_CHECK
2660 */
Dan Williamsad283ea2009-08-29 19:09:26 -07002661 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
Dan Williamsecc65c92008-06-28 08:31:57 +10002662 /* parity is correct (on disc,
2663 * not in buffer any more)
2664 */
2665 set_bit(STRIPE_INSYNC, &sh->state);
2666 else {
2667 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2668 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2669 /* don't try to repair!! */
2670 set_bit(STRIPE_INSYNC, &sh->state);
2671 else {
2672 sh->check_state = check_state_compute_run;
Dan Williams976ea8d2008-06-28 08:32:03 +10002673 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
Dan Williamsecc65c92008-06-28 08:31:57 +10002674 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2675 set_bit(R5_Wantcompute,
2676 &sh->dev[sh->pd_idx].flags);
2677 sh->ops.target = sh->pd_idx;
Dan Williamsac6b53b2009-07-14 13:40:19 -07002678 sh->ops.target2 = -1;
Dan Williamsecc65c92008-06-28 08:31:57 +10002679 s->uptodate++;
2680 }
2681 }
2682 break;
2683 case check_state_compute_run:
2684 break;
2685 default:
2686 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2687 __func__, sh->check_state,
2688 (unsigned long long) sh->sector);
2689 BUG();
Dan Williamsa4456852007-07-09 11:56:43 -07002690 }
2691}
2692
2693
2694static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
Dan Williams36d1c642009-07-14 11:48:22 -07002695 struct stripe_head_state *s,
2696 struct r6_state *r6s, int disks)
Dan Williamsa4456852007-07-09 11:56:43 -07002697{
Dan Williamsa4456852007-07-09 11:56:43 -07002698 int pd_idx = sh->pd_idx;
NeilBrown34e04e82009-03-31 15:10:16 +11002699 int qd_idx = sh->qd_idx;
Dan Williamsd82dfee2009-07-14 13:40:57 -07002700 struct r5dev *dev;
Dan Williamsa4456852007-07-09 11:56:43 -07002701
2702 set_bit(STRIPE_HANDLE, &sh->state);
2703
2704 BUG_ON(s->failed > 2);
Dan Williamsd82dfee2009-07-14 13:40:57 -07002705
Dan Williamsa4456852007-07-09 11:56:43 -07002706 /* Want to check and possibly repair P and Q.
2707 * However there could be one 'failed' device, in which
2708 * case we can only check one of them, possibly using the
2709 * other to generate missing data
2710 */
2711
Dan Williamsd82dfee2009-07-14 13:40:57 -07002712 switch (sh->check_state) {
2713 case check_state_idle:
2714 /* start a new check operation if there are < 2 failures */
Dan Williamsa4456852007-07-09 11:56:43 -07002715 if (s->failed == r6s->q_failed) {
Dan Williamsd82dfee2009-07-14 13:40:57 -07002716 /* The only possible failed device holds Q, so it
Dan Williamsa4456852007-07-09 11:56:43 -07002717 * makes sense to check P (If anything else were failed,
2718 * we would have used P to recreate it).
2719 */
Dan Williamsd82dfee2009-07-14 13:40:57 -07002720 sh->check_state = check_state_run;
Dan Williamsa4456852007-07-09 11:56:43 -07002721 }
2722 if (!r6s->q_failed && s->failed < 2) {
Dan Williamsd82dfee2009-07-14 13:40:57 -07002723 /* Q is not failed, and we didn't use it to generate
Dan Williamsa4456852007-07-09 11:56:43 -07002724 * anything, so it makes sense to check it
2725 */
Dan Williamsd82dfee2009-07-14 13:40:57 -07002726 if (sh->check_state == check_state_run)
2727 sh->check_state = check_state_run_pq;
2728 else
2729 sh->check_state = check_state_run_q;
Dan Williamsa4456852007-07-09 11:56:43 -07002730 }
Dan Williams36d1c642009-07-14 11:48:22 -07002731
Dan Williamsd82dfee2009-07-14 13:40:57 -07002732 /* discard potentially stale zero_sum_result */
2733 sh->ops.zero_sum_result = 0;
Dan Williams36d1c642009-07-14 11:48:22 -07002734
Dan Williamsd82dfee2009-07-14 13:40:57 -07002735 if (sh->check_state == check_state_run) {
2736 /* async_xor_zero_sum destroys the contents of P */
2737 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2738 s->uptodate--;
Dan Williamsa4456852007-07-09 11:56:43 -07002739 }
Dan Williamsd82dfee2009-07-14 13:40:57 -07002740 if (sh->check_state >= check_state_run &&
2741 sh->check_state <= check_state_run_pq) {
2742 /* async_syndrome_zero_sum preserves P and Q, so
2743 * no need to mark them !uptodate here
2744 */
2745 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2746 break;
2747 }
Dan Williams36d1c642009-07-14 11:48:22 -07002748
Dan Williamsd82dfee2009-07-14 13:40:57 -07002749 /* we have 2-disk failure */
2750 BUG_ON(s->failed != 2);
2751 /* fall through */
2752 case check_state_compute_result:
2753 sh->check_state = check_state_idle;
Dan Williams36d1c642009-07-14 11:48:22 -07002754
Dan Williamsd82dfee2009-07-14 13:40:57 -07002755 /* check that a write has not made the stripe insync */
2756 if (test_bit(STRIPE_INSYNC, &sh->state))
2757 break;
Dan Williamsa4456852007-07-09 11:56:43 -07002758
2759 /* now write out any block on a failed drive,
Dan Williamsd82dfee2009-07-14 13:40:57 -07002760 * or P or Q if they were recomputed
Dan Williamsa4456852007-07-09 11:56:43 -07002761 */
Dan Williamsd82dfee2009-07-14 13:40:57 -07002762 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
Dan Williamsa4456852007-07-09 11:56:43 -07002763 if (s->failed == 2) {
2764 dev = &sh->dev[r6s->failed_num[1]];
2765 s->locked++;
2766 set_bit(R5_LOCKED, &dev->flags);
2767 set_bit(R5_Wantwrite, &dev->flags);
2768 }
2769 if (s->failed >= 1) {
2770 dev = &sh->dev[r6s->failed_num[0]];
2771 s->locked++;
2772 set_bit(R5_LOCKED, &dev->flags);
2773 set_bit(R5_Wantwrite, &dev->flags);
2774 }
Dan Williamsd82dfee2009-07-14 13:40:57 -07002775 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
Dan Williamsa4456852007-07-09 11:56:43 -07002776 dev = &sh->dev[pd_idx];
2777 s->locked++;
2778 set_bit(R5_LOCKED, &dev->flags);
2779 set_bit(R5_Wantwrite, &dev->flags);
2780 }
Dan Williamsd82dfee2009-07-14 13:40:57 -07002781 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
Dan Williamsa4456852007-07-09 11:56:43 -07002782 dev = &sh->dev[qd_idx];
2783 s->locked++;
2784 set_bit(R5_LOCKED, &dev->flags);
2785 set_bit(R5_Wantwrite, &dev->flags);
2786 }
2787 clear_bit(STRIPE_DEGRADED, &sh->state);
2788
2789 set_bit(STRIPE_INSYNC, &sh->state);
Dan Williamsd82dfee2009-07-14 13:40:57 -07002790 break;
2791 case check_state_run:
2792 case check_state_run_q:
2793 case check_state_run_pq:
2794 break; /* we will be called again upon completion */
2795 case check_state_check_result:
2796 sh->check_state = check_state_idle;
2797
2798 /* handle a successful check operation, if parity is correct
2799 * we are done. Otherwise update the mismatch count and repair
2800 * parity if !MD_RECOVERY_CHECK
2801 */
2802 if (sh->ops.zero_sum_result == 0) {
2803 /* both parities are correct */
2804 if (!s->failed)
2805 set_bit(STRIPE_INSYNC, &sh->state);
2806 else {
2807 /* in contrast to the raid5 case we can validate
2808 * parity, but still have a failure to write
2809 * back
2810 */
2811 sh->check_state = check_state_compute_result;
2812 /* Returning at this point means that we may go
2813 * off and bring p and/or q uptodate again so
2814 * we make sure to check zero_sum_result again
2815 * to verify if p or q need writeback
2816 */
2817 }
2818 } else {
2819 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2820 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2821 /* don't try to repair!! */
2822 set_bit(STRIPE_INSYNC, &sh->state);
2823 else {
2824 int *target = &sh->ops.target;
2825
2826 sh->ops.target = -1;
2827 sh->ops.target2 = -1;
2828 sh->check_state = check_state_compute_run;
2829 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2830 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2831 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2832 set_bit(R5_Wantcompute,
2833 &sh->dev[pd_idx].flags);
2834 *target = pd_idx;
2835 target = &sh->ops.target2;
2836 s->uptodate++;
2837 }
2838 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2839 set_bit(R5_Wantcompute,
2840 &sh->dev[qd_idx].flags);
2841 *target = qd_idx;
2842 s->uptodate++;
2843 }
2844 }
2845 }
2846 break;
2847 case check_state_compute_run:
2848 break;
2849 default:
2850 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2851 __func__, sh->check_state,
2852 (unsigned long long) sh->sector);
2853 BUG();
Dan Williamsa4456852007-07-09 11:56:43 -07002854 }
2855}
2856
2857static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2858 struct r6_state *r6s)
2859{
2860 int i;
2861
2862 /* We have read all the blocks in this stripe and now we need to
2863 * copy some of them into a target stripe for expand.
2864 */
Dan Williamsf0a50d32007-01-02 13:52:31 -07002865 struct dma_async_tx_descriptor *tx = NULL;
Dan Williamsa4456852007-07-09 11:56:43 -07002866 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2867 for (i = 0; i < sh->disks; i++)
NeilBrown34e04e82009-03-31 15:10:16 +11002868 if (i != sh->pd_idx && i != sh->qd_idx) {
NeilBrown911d4ee2009-03-31 14:39:38 +11002869 int dd_idx, j;
Dan Williamsa4456852007-07-09 11:56:43 -07002870 struct stripe_head *sh2;
Dan Williamsa08abd82009-06-03 11:43:59 -07002871 struct async_submit_ctl submit;
Dan Williamsa4456852007-07-09 11:56:43 -07002872
NeilBrown784052e2009-03-31 15:19:07 +11002873 sector_t bn = compute_blocknr(sh, i, 1);
NeilBrown911d4ee2009-03-31 14:39:38 +11002874 sector_t s = raid5_compute_sector(conf, bn, 0,
2875 &dd_idx, NULL);
NeilBrowna8c906c2009-06-09 14:39:59 +10002876 sh2 = get_active_stripe(conf, s, 0, 1, 1);
Dan Williamsa4456852007-07-09 11:56:43 -07002877 if (sh2 == NULL)
2878 /* so far only the early blocks of this stripe
2879 * have been requested. When later blocks
2880 * get requested, we will try again
2881 */
2882 continue;
2883 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2884 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2885 /* must have already done this block */
2886 release_stripe(sh2);
2887 continue;
2888 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07002889
2890 /* place all the copies on one channel */
Dan Williamsa08abd82009-06-03 11:43:59 -07002891 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002892 tx = async_memcpy(sh2->dev[dd_idx].page,
Dan Williams88ba2aa2009-04-09 16:16:18 -07002893 sh->dev[i].page, 0, 0, STRIPE_SIZE,
Dan Williamsa08abd82009-06-03 11:43:59 -07002894 &submit);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002895
Dan Williamsa4456852007-07-09 11:56:43 -07002896 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2897 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2898 for (j = 0; j < conf->raid_disks; j++)
2899 if (j != sh2->pd_idx &&
NeilBrownd0dabf72009-03-31 14:39:38 +11002900 (!r6s || j != sh2->qd_idx) &&
Dan Williamsa4456852007-07-09 11:56:43 -07002901 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2902 break;
2903 if (j == conf->raid_disks) {
2904 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2905 set_bit(STRIPE_HANDLE, &sh2->state);
2906 }
2907 release_stripe(sh2);
Dan Williamsf0a50d32007-01-02 13:52:31 -07002908
Dan Williamsa4456852007-07-09 11:56:43 -07002909 }
NeilBrowna2e08552007-09-11 15:23:36 -07002910 /* done submitting copies, wait for them to complete */
2911 if (tx) {
2912 async_tx_ack(tx);
2913 dma_wait_for_async_tx(tx);
2914 }
Dan Williamsa4456852007-07-09 11:56:43 -07002915}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002916
Dan Williams6bfe0b42008-04-30 00:52:32 -07002917
Linus Torvalds1da177e2005-04-16 15:20:36 -07002918/*
2919 * handle_stripe - do things to a stripe.
2920 *
2921 * We lock the stripe and then examine the state of various bits
2922 * to see what needs to be done.
2923 * Possible results:
2924 * return some read request which now have data
2925 * return some write requests which are safely on disc
2926 * schedule a read on some buffers
2927 * schedule a write of some buffers
2928 * return confirmation of parity correctness
2929 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07002930 * buffers are taken off read_list or write_list, and bh_cache buffers
2931 * get BH_Lock set before the stripe lock is released.
2932 *
2933 */
Dan Williamsa4456852007-07-09 11:56:43 -07002934
NeilBrown14425772009-10-16 15:55:25 +11002935static void handle_stripe5(struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002936{
2937 raid5_conf_t *conf = sh->raid_conf;
Dan Williamsa4456852007-07-09 11:56:43 -07002938 int disks = sh->disks, i;
2939 struct bio *return_bi = NULL;
2940 struct stripe_head_state s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002941 struct r5dev *dev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07002942 mdk_rdev_t *blocked_rdev = NULL;
Dan Williamse0a115e2008-06-05 22:45:52 -07002943 int prexor;
NeilBrown729a1862009-12-14 12:49:50 +11002944 int dec_preread_active = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002945
Dan Williamsa4456852007-07-09 11:56:43 -07002946 memset(&s, 0, sizeof(s));
Dan Williams600aa102008-06-28 08:32:05 +10002947 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2948 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
2949 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
2950 sh->reconstruct_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002951
2952 spin_lock(&sh->lock);
2953 clear_bit(STRIPE_HANDLE, &sh->state);
2954 clear_bit(STRIPE_DELAYED, &sh->state);
2955
Dan Williamsa4456852007-07-09 11:56:43 -07002956 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2957 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2958 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
Dan Williams83de75c2008-06-28 08:31:58 +10002959
Linus Torvalds1da177e2005-04-16 15:20:36 -07002960 /* Now to look around and see what can be done */
NeilBrown9910f162006-01-06 00:20:24 -08002961 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002962 for (i=disks; i--; ) {
2963 mdk_rdev_t *rdev;
NeilBrowna9f326e2009-09-23 18:06:41 +10002964
2965 dev = &sh->dev[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002966 clear_bit(R5_Insync, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002967
Dan Williamsb5e98d62007-01-02 13:52:31 -07002968 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2969 "written %p\n", i, dev->flags, dev->toread, dev->read,
2970 dev->towrite, dev->written);
2971
2972 /* maybe we can request a biofill operation
2973 *
2974 * new wantfill requests are only permitted while
Dan Williams83de75c2008-06-28 08:31:58 +10002975 * ops_complete_biofill is guaranteed to be inactive
Dan Williamsb5e98d62007-01-02 13:52:31 -07002976 */
2977 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
Dan Williams83de75c2008-06-28 08:31:58 +10002978 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
Dan Williamsb5e98d62007-01-02 13:52:31 -07002979 set_bit(R5_Wantfill, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002980
2981 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07002982 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2983 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williamsf38e1212007-01-02 13:52:30 -07002984 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002985
Dan Williamsb5e98d62007-01-02 13:52:31 -07002986 if (test_bit(R5_Wantfill, &dev->flags))
2987 s.to_fill++;
2988 else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07002989 s.to_read++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002990 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07002991 s.to_write++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002992 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07002993 s.non_overwrite++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002994 }
Dan Williamsa4456852007-07-09 11:56:43 -07002995 if (dev->written)
2996 s.written++;
NeilBrown9910f162006-01-06 00:20:24 -08002997 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10002998 if (blocked_rdev == NULL &&
2999 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07003000 blocked_rdev = rdev;
3001 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07003002 }
NeilBrownb2d444d2005-11-08 21:39:31 -08003003 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
NeilBrown14f8d262006-01-06 00:20:14 -08003004 /* The ReadError flag will just be confusing now */
NeilBrown4e5314b2005-11-08 21:39:22 -08003005 clear_bit(R5_ReadError, &dev->flags);
3006 clear_bit(R5_ReWrite, &dev->flags);
3007 }
NeilBrownb2d444d2005-11-08 21:39:31 -08003008 if (!rdev || !test_bit(In_sync, &rdev->flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08003009 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07003010 s.failed++;
3011 s.failed_num = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003012 } else
3013 set_bit(R5_Insync, &dev->flags);
3014 }
NeilBrown9910f162006-01-06 00:20:24 -08003015 rcu_read_unlock();
Dan Williamsb5e98d62007-01-02 13:52:31 -07003016
Dan Williams6bfe0b42008-04-30 00:52:32 -07003017 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10003018 if (s.syncing || s.expanding || s.expanded ||
3019 s.to_write || s.written) {
3020 set_bit(STRIPE_HANDLE, &sh->state);
3021 goto unlock;
3022 }
3023 /* There is nothing for the blocked_rdev to block */
3024 rdev_dec_pending(blocked_rdev, conf->mddev);
3025 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003026 }
3027
Dan Williams83de75c2008-06-28 08:31:58 +10003028 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3029 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3030 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3031 }
Dan Williamsb5e98d62007-01-02 13:52:31 -07003032
Dan Williams45b42332007-07-09 11:56:43 -07003033 pr_debug("locked=%d uptodate=%d to_read=%d"
Linus Torvalds1da177e2005-04-16 15:20:36 -07003034 " to_write=%d failed=%d failed_num=%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003035 s.locked, s.uptodate, s.to_read, s.to_write,
3036 s.failed, s.failed_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003037 /* check if the array has lost two devices and, if so, some requests might
3038 * need to be failed
3039 */
Dan Williamsa4456852007-07-09 11:56:43 -07003040 if (s.failed > 1 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10003041 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07003042 if (s.failed > 1 && s.syncing) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003043 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3044 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003045 s.syncing = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003046 }
3047
3048 /* might be able to return some write requests if the parity block
3049 * is safe, or on a failed drive
3050 */
3051 dev = &sh->dev[sh->pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07003052 if ( s.written &&
3053 ((test_bit(R5_Insync, &dev->flags) &&
3054 !test_bit(R5_LOCKED, &dev->flags) &&
3055 test_bit(R5_UPTODATE, &dev->flags)) ||
3056 (s.failed == 1 && s.failed_num == sh->pd_idx)))
Dan Williams1fe797e2008-06-28 09:16:30 +10003057 handle_stripe_clean_event(conf, sh, disks, &return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003058
3059 /* Now we might consider reading some blocks, either to check/generate
3060 * parity, or to satisfy requests
3061 * or to load a block that is being partially written.
3062 */
Dan Williamsa4456852007-07-09 11:56:43 -07003063 if (s.to_read || s.non_overwrite ||
Dan Williams976ea8d2008-06-28 08:32:03 +10003064 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10003065 handle_stripe_fill5(sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003066
Dan Williamse33129d2007-01-02 13:52:30 -07003067 /* Now we check to see if any write operations have recently
3068 * completed
3069 */
Dan Williamse0a115e2008-06-05 22:45:52 -07003070 prexor = 0;
Dan Williamsd8ee0722008-06-28 08:32:06 +10003071 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
Dan Williamse0a115e2008-06-05 22:45:52 -07003072 prexor = 1;
Dan Williamsd8ee0722008-06-28 08:32:06 +10003073 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3074 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
Dan Williams600aa102008-06-28 08:32:05 +10003075 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamse33129d2007-01-02 13:52:30 -07003076
3077 /* All the 'written' buffers and the parity block are ready to
3078 * be written back to disk
3079 */
3080 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3081 for (i = disks; i--; ) {
3082 dev = &sh->dev[i];
3083 if (test_bit(R5_LOCKED, &dev->flags) &&
3084 (i == sh->pd_idx || dev->written)) {
3085 pr_debug("Writing block %d\n", i);
3086 set_bit(R5_Wantwrite, &dev->flags);
Dan Williamse0a115e2008-06-05 22:45:52 -07003087 if (prexor)
3088 continue;
Dan Williamse33129d2007-01-02 13:52:30 -07003089 if (!test_bit(R5_Insync, &dev->flags) ||
3090 (i == sh->pd_idx && s.failed == 0))
3091 set_bit(STRIPE_INSYNC, &sh->state);
3092 }
3093 }
NeilBrown729a1862009-12-14 12:49:50 +11003094 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3095 dec_preread_active = 1;
Dan Williamse33129d2007-01-02 13:52:30 -07003096 }
3097
3098 /* Now to consider new write requests and what else, if anything
3099 * should be read. We do not handle new writes when:
3100 * 1/ A 'write' operation (copy+xor) is already in flight.
3101 * 2/ A 'check' operation is in flight, as it may clobber the parity
3102 * block.
3103 */
Dan Williams600aa102008-06-28 08:32:05 +10003104 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
Dan Williams1fe797e2008-06-28 09:16:30 +10003105 handle_stripe_dirtying5(conf, sh, &s, disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003106
3107 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamse89f8962007-01-02 13:52:31 -07003108 * Any reads will already have been scheduled, so we just see if enough
3109 * data is available. The parity check is held off while parity
3110 * dependent operations are in flight.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003111 */
Dan Williamsecc65c92008-06-28 08:31:57 +10003112 if (sh->check_state ||
3113 (s.syncing && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10003114 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
Dan Williamsecc65c92008-06-28 08:31:57 +10003115 !test_bit(STRIPE_INSYNC, &sh->state)))
Dan Williamsa4456852007-07-09 11:56:43 -07003116 handle_parity_checks5(conf, sh, &s, disks);
Dan Williamse89f8962007-01-02 13:52:31 -07003117
Dan Williamsa4456852007-07-09 11:56:43 -07003118 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003119 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3120 clear_bit(STRIPE_SYNCING, &sh->state);
3121 }
NeilBrown4e5314b2005-11-08 21:39:22 -08003122
3123 /* If the failed drive is just a ReadError, then we might need to progress
3124 * the repair/check process
3125 */
Dan Williamsa4456852007-07-09 11:56:43 -07003126 if (s.failed == 1 && !conf->mddev->ro &&
3127 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
3128 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
3129 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
NeilBrown4e5314b2005-11-08 21:39:22 -08003130 ) {
Dan Williamsa4456852007-07-09 11:56:43 -07003131 dev = &sh->dev[s.failed_num];
NeilBrown4e5314b2005-11-08 21:39:22 -08003132 if (!test_bit(R5_ReWrite, &dev->flags)) {
3133 set_bit(R5_Wantwrite, &dev->flags);
3134 set_bit(R5_ReWrite, &dev->flags);
3135 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003136 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08003137 } else {
3138 /* let's read it back */
3139 set_bit(R5_Wantread, &dev->flags);
3140 set_bit(R5_LOCKED, &dev->flags);
Dan Williamsa4456852007-07-09 11:56:43 -07003141 s.locked++;
NeilBrown4e5314b2005-11-08 21:39:22 -08003142 }
3143 }
3144
Dan Williams600aa102008-06-28 08:32:05 +10003145 /* Finish reconstruct operations initiated by the expansion process */
3146 if (sh->reconstruct_state == reconstruct_state_result) {
NeilBrownab69ae12009-03-31 15:26:47 +11003147 struct stripe_head *sh2
NeilBrowna8c906c2009-06-09 14:39:59 +10003148 = get_active_stripe(conf, sh->sector, 1, 1, 1);
NeilBrownab69ae12009-03-31 15:26:47 +11003149 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3150 /* sh cannot be written until sh2 has been read.
3151 * so arrange for sh to be delayed a little
3152 */
3153 set_bit(STRIPE_DELAYED, &sh->state);
3154 set_bit(STRIPE_HANDLE, &sh->state);
3155 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3156 &sh2->state))
3157 atomic_inc(&conf->preread_active_stripes);
3158 release_stripe(sh2);
3159 goto unlock;
3160 }
3161 if (sh2)
3162 release_stripe(sh2);
3163
Dan Williams600aa102008-06-28 08:32:05 +10003164 sh->reconstruct_state = reconstruct_state_idle;
Dan Williamsf0a50d32007-01-02 13:52:31 -07003165 clear_bit(STRIPE_EXPANDING, &sh->state);
Dan Williams23397882008-07-23 20:05:34 -07003166 for (i = conf->raid_disks; i--; ) {
Dan Williamsf0a50d32007-01-02 13:52:31 -07003167 set_bit(R5_Wantwrite, &sh->dev[i].flags);
Dan Williams23397882008-07-23 20:05:34 -07003168 set_bit(R5_LOCKED, &sh->dev[i].flags);
Neil Brownefe31142008-06-28 08:31:14 +10003169 s.locked++;
Dan Williams23397882008-07-23 20:05:34 -07003170 }
Dan Williamsf0a50d32007-01-02 13:52:31 -07003171 }
3172
3173 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
Dan Williams600aa102008-06-28 08:32:05 +10003174 !sh->reconstruct_state) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08003175 /* Need to write out all blocks after computing parity */
3176 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11003177 stripe_set_idx(sh->sector, conf, 0, sh);
Yuri Tikhonovc0f7bdd2009-08-29 19:13:12 -07003178 schedule_reconstruction(sh, &s, 1, 1);
Dan Williams600aa102008-06-28 08:32:05 +10003179 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
NeilBrownccfcc3c2006-03-27 01:18:09 -08003180 clear_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrownf6705572006-03-27 01:18:11 -08003181 atomic_dec(&conf->reshape_stripes);
NeilBrownccfcc3c2006-03-27 01:18:09 -08003182 wake_up(&conf->wait_for_overlap);
3183 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3184 }
3185
Dan Williams0f94e872008-01-08 15:32:53 -08003186 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10003187 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07003188 handle_stripe_expansion(conf, sh, NULL);
NeilBrownccfcc3c2006-03-27 01:18:09 -08003189
Dan Williams6bfe0b42008-04-30 00:52:32 -07003190 unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191 spin_unlock(&sh->lock);
3192
Dan Williams6bfe0b42008-04-30 00:52:32 -07003193 /* wait for this device to become unblocked */
3194 if (unlikely(blocked_rdev))
3195 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3196
Dan Williams600aa102008-06-28 08:32:05 +10003197 if (s.ops_request)
Dan Williamsac6b53b2009-07-14 13:40:19 -07003198 raid_run_ops(sh, s.ops_request);
Dan Williamsd84e0f12007-01-02 13:52:30 -07003199
Dan Williamsc4e5ac02008-06-28 08:31:53 +10003200 ops_run_io(sh, &s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003201
NeilBrown729a1862009-12-14 12:49:50 +11003202 if (dec_preread_active) {
3203 /* We delay this until after ops_run_io so that if make_request
3204 * is waiting on a barrier, it won't continue until the writes
3205 * have actually been submitted.
3206 */
3207 atomic_dec(&conf->preread_active_stripes);
3208 if (atomic_read(&conf->preread_active_stripes) <
3209 IO_THRESHOLD)
3210 md_wakeup_thread(conf->mddev->thread);
3211 }
Dan Williamsa4456852007-07-09 11:56:43 -07003212 return_io(return_bi);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003213}
3214
NeilBrown14425772009-10-16 15:55:25 +11003215static void handle_stripe6(struct stripe_head *sh)
NeilBrown16a53ec2006-06-26 00:27:38 -07003216{
NeilBrownbff61972009-03-31 14:33:13 +11003217 raid5_conf_t *conf = sh->raid_conf;
NeilBrownf4168852007-02-28 20:11:53 -08003218 int disks = sh->disks;
Dan Williamsa4456852007-07-09 11:56:43 -07003219 struct bio *return_bi = NULL;
NeilBrown34e04e82009-03-31 15:10:16 +11003220 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
Dan Williamsa4456852007-07-09 11:56:43 -07003221 struct stripe_head_state s;
3222 struct r6_state r6s;
NeilBrown16a53ec2006-06-26 00:27:38 -07003223 struct r5dev *dev, *pdev, *qdev;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003224 mdk_rdev_t *blocked_rdev = NULL;
NeilBrown729a1862009-12-14 12:49:50 +11003225 int dec_preread_active = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07003226
Dan Williams45b42332007-07-09 11:56:43 -07003227 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003228 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003229 (unsigned long long)sh->sector, sh->state,
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003230 atomic_read(&sh->count), pd_idx, qd_idx,
3231 sh->check_state, sh->reconstruct_state);
Dan Williamsa4456852007-07-09 11:56:43 -07003232 memset(&s, 0, sizeof(s));
NeilBrown16a53ec2006-06-26 00:27:38 -07003233
3234 spin_lock(&sh->lock);
3235 clear_bit(STRIPE_HANDLE, &sh->state);
3236 clear_bit(STRIPE_DELAYED, &sh->state);
3237
Dan Williamsa4456852007-07-09 11:56:43 -07003238 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3239 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3240 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
NeilBrown16a53ec2006-06-26 00:27:38 -07003241 /* Now to look around and see what can be done */
3242
3243 rcu_read_lock();
3244 for (i=disks; i--; ) {
3245 mdk_rdev_t *rdev;
3246 dev = &sh->dev[i];
3247 clear_bit(R5_Insync, &dev->flags);
3248
Dan Williams45b42332007-07-09 11:56:43 -07003249 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
NeilBrown16a53ec2006-06-26 00:27:38 -07003250 i, dev->flags, dev->toread, dev->towrite, dev->written);
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003251 /* maybe we can reply to a read
3252 *
3253 * new wantfill requests are only permitted while
3254 * ops_complete_biofill is guaranteed to be inactive
3255 */
3256 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3257 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3258 set_bit(R5_Wantfill, &dev->flags);
NeilBrown16a53ec2006-06-26 00:27:38 -07003259
3260 /* now count some things */
Dan Williamsa4456852007-07-09 11:56:43 -07003261 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3262 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
Dan Williams2d6e4ec2009-09-16 12:11:54 -07003263 if (test_bit(R5_Wantcompute, &dev->flags)) {
3264 s.compute++;
3265 BUG_ON(s.compute > 2);
3266 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003267
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003268 if (test_bit(R5_Wantfill, &dev->flags)) {
3269 s.to_fill++;
3270 } else if (dev->toread)
Dan Williamsa4456852007-07-09 11:56:43 -07003271 s.to_read++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003272 if (dev->towrite) {
Dan Williamsa4456852007-07-09 11:56:43 -07003273 s.to_write++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003274 if (!test_bit(R5_OVERWRITE, &dev->flags))
Dan Williamsa4456852007-07-09 11:56:43 -07003275 s.non_overwrite++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003276 }
Dan Williamsa4456852007-07-09 11:56:43 -07003277 if (dev->written)
3278 s.written++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003279 rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownac4090d2008-08-05 15:54:13 +10003280 if (blocked_rdev == NULL &&
3281 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
Dan Williams6bfe0b42008-04-30 00:52:32 -07003282 blocked_rdev = rdev;
3283 atomic_inc(&rdev->nr_pending);
Dan Williams6bfe0b42008-04-30 00:52:32 -07003284 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003285 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
3286 /* The ReadError flag will just be confusing now */
3287 clear_bit(R5_ReadError, &dev->flags);
3288 clear_bit(R5_ReWrite, &dev->flags);
3289 }
3290 if (!rdev || !test_bit(In_sync, &rdev->flags)
3291 || test_bit(R5_ReadError, &dev->flags)) {
Dan Williamsa4456852007-07-09 11:56:43 -07003292 if (s.failed < 2)
3293 r6s.failed_num[s.failed] = i;
3294 s.failed++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003295 } else
3296 set_bit(R5_Insync, &dev->flags);
3297 }
3298 rcu_read_unlock();
Dan Williams6bfe0b42008-04-30 00:52:32 -07003299
3300 if (unlikely(blocked_rdev)) {
NeilBrownac4090d2008-08-05 15:54:13 +10003301 if (s.syncing || s.expanding || s.expanded ||
3302 s.to_write || s.written) {
3303 set_bit(STRIPE_HANDLE, &sh->state);
3304 goto unlock;
3305 }
3306 /* There is nothing for the blocked_rdev to block */
3307 rdev_dec_pending(blocked_rdev, conf->mddev);
3308 blocked_rdev = NULL;
Dan Williams6bfe0b42008-04-30 00:52:32 -07003309 }
NeilBrownac4090d2008-08-05 15:54:13 +10003310
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003311 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3312 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3313 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3314 }
3315
Dan Williams45b42332007-07-09 11:56:43 -07003316 pr_debug("locked=%d uptodate=%d to_read=%d"
NeilBrown16a53ec2006-06-26 00:27:38 -07003317 " to_write=%d failed=%d failed_num=%d,%d\n",
Dan Williamsa4456852007-07-09 11:56:43 -07003318 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3319 r6s.failed_num[0], r6s.failed_num[1]);
3320 /* check if the array has lost >2 devices and, if so, some requests
3321 * might need to be failed
NeilBrown16a53ec2006-06-26 00:27:38 -07003322 */
Dan Williamsa4456852007-07-09 11:56:43 -07003323 if (s.failed > 2 && s.to_read+s.to_write+s.written)
Dan Williams1fe797e2008-06-28 09:16:30 +10003324 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
Dan Williamsa4456852007-07-09 11:56:43 -07003325 if (s.failed > 2 && s.syncing) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003326 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3327 clear_bit(STRIPE_SYNCING, &sh->state);
Dan Williamsa4456852007-07-09 11:56:43 -07003328 s.syncing = 0;
NeilBrown16a53ec2006-06-26 00:27:38 -07003329 }
3330
3331 /*
3332 * might be able to return some write requests if the parity blocks
3333 * are safe, or on a failed drive
3334 */
3335 pdev = &sh->dev[pd_idx];
Dan Williamsa4456852007-07-09 11:56:43 -07003336 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3337 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
NeilBrown34e04e82009-03-31 15:10:16 +11003338 qdev = &sh->dev[qd_idx];
3339 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3340 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
NeilBrown16a53ec2006-06-26 00:27:38 -07003341
Dan Williamsa4456852007-07-09 11:56:43 -07003342 if ( s.written &&
3343 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003344 && !test_bit(R5_LOCKED, &pdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003345 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3346 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
NeilBrown16a53ec2006-06-26 00:27:38 -07003347 && !test_bit(R5_LOCKED, &qdev->flags)
Dan Williamsa4456852007-07-09 11:56:43 -07003348 && test_bit(R5_UPTODATE, &qdev->flags)))))
Dan Williams1fe797e2008-06-28 09:16:30 +10003349 handle_stripe_clean_event(conf, sh, disks, &return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003350
3351 /* Now we might consider reading some blocks, either to check/generate
3352 * parity, or to satisfy requests
3353 * or to load a block that is being partially written.
3354 */
Dan Williamsa4456852007-07-09 11:56:43 -07003355 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003356 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
Dan Williams1fe797e2008-06-28 09:16:30 +10003357 handle_stripe_fill6(sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003358
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003359 /* Now we check to see if any write operations have recently
3360 * completed
3361 */
3362 if (sh->reconstruct_state == reconstruct_state_drain_result) {
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003363
3364 sh->reconstruct_state = reconstruct_state_idle;
3365 /* All the 'written' buffers and the parity blocks are ready to
3366 * be written back to disk
3367 */
3368 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3369 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
3370 for (i = disks; i--; ) {
3371 dev = &sh->dev[i];
3372 if (test_bit(R5_LOCKED, &dev->flags) &&
3373 (i == sh->pd_idx || i == qd_idx ||
3374 dev->written)) {
3375 pr_debug("Writing block %d\n", i);
3376 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3377 set_bit(R5_Wantwrite, &dev->flags);
3378 if (!test_bit(R5_Insync, &dev->flags) ||
3379 ((i == sh->pd_idx || i == qd_idx) &&
3380 s.failed == 0))
3381 set_bit(STRIPE_INSYNC, &sh->state);
3382 }
3383 }
NeilBrown729a1862009-12-14 12:49:50 +11003384 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3385 dec_preread_active = 1;
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003386 }
3387
Yuri Tikhonova9b39a72009-08-29 19:13:12 -07003388 /* Now to consider new write requests and what else, if anything
3389 * should be read. We do not handle new writes when:
3390 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3391 * 2/ A 'check' operation is in flight, as it may clobber the parity
3392 * block.
3393 */
3394 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
Dan Williams1fe797e2008-06-28 09:16:30 +10003395 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003396
3397 /* maybe we need to check and possibly fix the parity for this stripe
Dan Williamsa4456852007-07-09 11:56:43 -07003398 * Any reads will already have been scheduled, so we just see if enough
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003399 * data is available. The parity check is held off while parity
3400 * dependent operations are in flight.
NeilBrown16a53ec2006-06-26 00:27:38 -07003401 */
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003402 if (sh->check_state ||
3403 (s.syncing && s.locked == 0 &&
3404 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3405 !test_bit(STRIPE_INSYNC, &sh->state)))
Dan Williams36d1c642009-07-14 11:48:22 -07003406 handle_parity_checks6(conf, sh, &s, &r6s, disks);
NeilBrown16a53ec2006-06-26 00:27:38 -07003407
Dan Williamsa4456852007-07-09 11:56:43 -07003408 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
NeilBrown16a53ec2006-06-26 00:27:38 -07003409 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3410 clear_bit(STRIPE_SYNCING, &sh->state);
3411 }
3412
3413 /* If the failed drives are just a ReadError, then we might need
3414 * to progress the repair/check process
3415 */
Dan Williamsa4456852007-07-09 11:56:43 -07003416 if (s.failed <= 2 && !conf->mddev->ro)
3417 for (i = 0; i < s.failed; i++) {
3418 dev = &sh->dev[r6s.failed_num[i]];
NeilBrown16a53ec2006-06-26 00:27:38 -07003419 if (test_bit(R5_ReadError, &dev->flags)
3420 && !test_bit(R5_LOCKED, &dev->flags)
3421 && test_bit(R5_UPTODATE, &dev->flags)
3422 ) {
3423 if (!test_bit(R5_ReWrite, &dev->flags)) {
3424 set_bit(R5_Wantwrite, &dev->flags);
3425 set_bit(R5_ReWrite, &dev->flags);
3426 set_bit(R5_LOCKED, &dev->flags);
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003427 s.locked++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003428 } else {
3429 /* let's read it back */
3430 set_bit(R5_Wantread, &dev->flags);
3431 set_bit(R5_LOCKED, &dev->flags);
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003432 s.locked++;
NeilBrown16a53ec2006-06-26 00:27:38 -07003433 }
3434 }
3435 }
NeilBrownf4168852007-02-28 20:11:53 -08003436
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003437 /* Finish reconstruct operations initiated by the expansion process */
3438 if (sh->reconstruct_state == reconstruct_state_result) {
3439 sh->reconstruct_state = reconstruct_state_idle;
3440 clear_bit(STRIPE_EXPANDING, &sh->state);
3441 for (i = conf->raid_disks; i--; ) {
3442 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3443 set_bit(R5_LOCKED, &sh->dev[i].flags);
3444 s.locked++;
3445 }
3446 }
3447
3448 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3449 !sh->reconstruct_state) {
NeilBrownab69ae12009-03-31 15:26:47 +11003450 struct stripe_head *sh2
NeilBrowna8c906c2009-06-09 14:39:59 +10003451 = get_active_stripe(conf, sh->sector, 1, 1, 1);
NeilBrownab69ae12009-03-31 15:26:47 +11003452 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3453 /* sh cannot be written until sh2 has been read.
3454 * so arrange for sh to be delayed a little
3455 */
3456 set_bit(STRIPE_DELAYED, &sh->state);
3457 set_bit(STRIPE_HANDLE, &sh->state);
3458 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3459 &sh2->state))
3460 atomic_inc(&conf->preread_active_stripes);
3461 release_stripe(sh2);
3462 goto unlock;
3463 }
3464 if (sh2)
3465 release_stripe(sh2);
3466
NeilBrownf4168852007-02-28 20:11:53 -08003467 /* Need to write out all blocks after computing P&Q */
3468 sh->disks = conf->raid_disks;
NeilBrown911d4ee2009-03-31 14:39:38 +11003469 stripe_set_idx(sh->sector, conf, 0, sh);
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003470 schedule_reconstruction(sh, &s, 1, 1);
3471 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
NeilBrownf4168852007-02-28 20:11:53 -08003472 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3473 atomic_dec(&conf->reshape_stripes);
3474 wake_up(&conf->wait_for_overlap);
3475 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3476 }
3477
Dan Williams0f94e872008-01-08 15:32:53 -08003478 if (s.expanding && s.locked == 0 &&
Dan Williams976ea8d2008-06-28 08:32:03 +10003479 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
Dan Williamsa4456852007-07-09 11:56:43 -07003480 handle_stripe_expansion(conf, sh, &r6s);
NeilBrownf4168852007-02-28 20:11:53 -08003481
Dan Williams6bfe0b42008-04-30 00:52:32 -07003482 unlock:
NeilBrown16a53ec2006-06-26 00:27:38 -07003483 spin_unlock(&sh->lock);
3484
Dan Williams6bfe0b42008-04-30 00:52:32 -07003485 /* wait for this device to become unblocked */
3486 if (unlikely(blocked_rdev))
3487 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3488
Yuri Tikhonov6c0069c2009-08-29 19:13:13 -07003489 if (s.ops_request)
3490 raid_run_ops(sh, s.ops_request);
3491
Dan Williamsf0e43bc2008-06-28 08:31:55 +10003492 ops_run_io(sh, &s);
3493
NeilBrown729a1862009-12-14 12:49:50 +11003494
3495 if (dec_preread_active) {
3496 /* We delay this until after ops_run_io so that if make_request
3497 * is waiting on a barrier, it won't continue until the writes
3498 * have actually been submitted.
3499 */
3500 atomic_dec(&conf->preread_active_stripes);
3501 if (atomic_read(&conf->preread_active_stripes) <
3502 IO_THRESHOLD)
3503 md_wakeup_thread(conf->mddev->thread);
3504 }
3505
Dan Williamsa4456852007-07-09 11:56:43 -07003506 return_io(return_bi);
NeilBrown16a53ec2006-06-26 00:27:38 -07003507}
3508
NeilBrown14425772009-10-16 15:55:25 +11003509static void handle_stripe(struct stripe_head *sh)
NeilBrown16a53ec2006-06-26 00:27:38 -07003510{
3511 if (sh->raid_conf->level == 6)
NeilBrown14425772009-10-16 15:55:25 +11003512 handle_stripe6(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -07003513 else
NeilBrown14425772009-10-16 15:55:25 +11003514 handle_stripe5(sh);
NeilBrown16a53ec2006-06-26 00:27:38 -07003515}
3516
Arjan van de Ven858119e2006-01-14 13:20:43 -08003517static void raid5_activate_delayed(raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003518{
3519 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3520 while (!list_empty(&conf->delayed_list)) {
3521 struct list_head *l = conf->delayed_list.next;
3522 struct stripe_head *sh;
3523 sh = list_entry(l, struct stripe_head, lru);
3524 list_del_init(l);
3525 clear_bit(STRIPE_DELAYED, &sh->state);
3526 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3527 atomic_inc(&conf->preread_active_stripes);
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003528 list_add_tail(&sh->lru, &conf->hold_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003529 }
NeilBrown6ed30032008-02-06 01:40:00 -08003530 } else
3531 blk_plug_device(conf->mddev->queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003532}
3533
Arjan van de Ven858119e2006-01-14 13:20:43 -08003534static void activate_bit_delay(raid5_conf_t *conf)
NeilBrown72626682005-09-09 16:23:54 -07003535{
3536 /* device_lock is held */
3537 struct list_head head;
3538 list_add(&head, &conf->bitmap_list);
3539 list_del_init(&conf->bitmap_list);
3540 while (!list_empty(&head)) {
3541 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3542 list_del_init(&sh->lru);
3543 atomic_inc(&sh->count);
3544 __release_stripe(conf, sh);
3545 }
3546}
3547
Linus Torvalds1da177e2005-04-16 15:20:36 -07003548static void unplug_slaves(mddev_t *mddev)
3549{
NeilBrown070ec552009-06-16 16:54:21 +10003550 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003551 int i;
NeilBrown5e5e3e72009-10-16 16:35:30 +11003552 int devs = max(conf->raid_disks, conf->previous_raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003553
3554 rcu_read_lock();
NeilBrown5e5e3e72009-10-16 16:35:30 +11003555 for (i = 0; i < devs; i++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -08003556 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -08003557 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +02003558 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003559
3560 atomic_inc(&rdev->nr_pending);
3561 rcu_read_unlock();
3562
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -05003563 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003564
3565 rdev_dec_pending(rdev, mddev);
3566 rcu_read_lock();
3567 }
3568 }
3569 rcu_read_unlock();
3570}
3571
Jens Axboe165125e2007-07-24 09:28:11 +02003572static void raid5_unplug_device(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003573{
3574 mddev_t *mddev = q->queuedata;
NeilBrown070ec552009-06-16 16:54:21 +10003575 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003576 unsigned long flags;
3577
3578 spin_lock_irqsave(&conf->device_lock, flags);
3579
NeilBrown72626682005-09-09 16:23:54 -07003580 if (blk_remove_plug(q)) {
3581 conf->seq_flush++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003582 raid5_activate_delayed(conf);
NeilBrown72626682005-09-09 16:23:54 -07003583 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003584 md_wakeup_thread(mddev->thread);
3585
3586 spin_unlock_irqrestore(&conf->device_lock, flags);
3587
3588 unplug_slaves(mddev);
3589}
3590
NeilBrownf022b2f2006-10-03 01:15:56 -07003591static int raid5_congested(void *data, int bits)
3592{
3593 mddev_t *mddev = data;
NeilBrown070ec552009-06-16 16:54:21 +10003594 raid5_conf_t *conf = mddev->private;
NeilBrownf022b2f2006-10-03 01:15:56 -07003595
3596 /* No difference between reads and writes. Just check
3597 * how busy the stripe_cache is
3598 */
NeilBrown3fa841d2009-09-23 18:10:29 +10003599
3600 if (mddev_congested(mddev, bits))
3601 return 1;
NeilBrownf022b2f2006-10-03 01:15:56 -07003602 if (conf->inactive_blocked)
3603 return 1;
3604 if (conf->quiesce)
3605 return 1;
3606 if (list_empty_careful(&conf->inactive_list))
3607 return 1;
3608
3609 return 0;
3610}
3611
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003612/* We want read requests to align with chunks where possible,
3613 * but write requests don't need to.
3614 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003615static int raid5_mergeable_bvec(struct request_queue *q,
3616 struct bvec_merge_data *bvm,
3617 struct bio_vec *biovec)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003618{
3619 mddev_t *mddev = q->queuedata;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003620 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003621 int max;
Andre Noll9d8f0362009-06-18 08:45:01 +10003622 unsigned int chunk_sectors = mddev->chunk_sectors;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003623 unsigned int bio_sectors = bvm->bi_size >> 9;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003624
Alasdair G Kergoncc371e62008-07-03 09:53:43 +02003625 if ((bvm->bi_rw & 1) == WRITE)
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003626 return biovec->bv_len; /* always allow writes to be mergeable */
3627
Andre Noll664e7c42009-06-18 08:45:27 +10003628 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3629 chunk_sectors = mddev->new_chunk_sectors;
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08003630 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3631 if (max < 0) max = 0;
3632 if (max <= biovec->bv_len && bio_sectors == 0)
3633 return biovec->bv_len;
3634 else
3635 return max;
3636}
3637
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003638
3639static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3640{
3641 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
Andre Noll9d8f0362009-06-18 08:45:01 +10003642 unsigned int chunk_sectors = mddev->chunk_sectors;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003643 unsigned int bio_sectors = bio->bi_size >> 9;
3644
Andre Noll664e7c42009-06-18 08:45:27 +10003645 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3646 chunk_sectors = mddev->new_chunk_sectors;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003647 return chunk_sectors >=
3648 ((sector & (chunk_sectors - 1)) + bio_sectors);
3649}
3650
3651/*
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003652 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3653 * later sampled by raid5d.
3654 */
3655static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3656{
3657 unsigned long flags;
3658
3659 spin_lock_irqsave(&conf->device_lock, flags);
3660
3661 bi->bi_next = conf->retry_read_aligned_list;
3662 conf->retry_read_aligned_list = bi;
3663
3664 spin_unlock_irqrestore(&conf->device_lock, flags);
3665 md_wakeup_thread(conf->mddev->thread);
3666}
3667
3668
3669static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3670{
3671 struct bio *bi;
3672
3673 bi = conf->retry_read_aligned;
3674 if (bi) {
3675 conf->retry_read_aligned = NULL;
3676 return bi;
3677 }
3678 bi = conf->retry_read_aligned_list;
3679 if(bi) {
Neil Brown387bb172007-02-08 14:20:29 -08003680 conf->retry_read_aligned_list = bi->bi_next;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003681 bi->bi_next = NULL;
Jens Axboe960e7392008-08-15 10:41:18 +02003682 /*
3683 * this sets the active strip count to 1 and the processed
3684 * strip count to zero (upper 8 bits)
3685 */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003686 bi->bi_phys_segments = 1; /* biased count of active stripes */
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003687 }
3688
3689 return bi;
3690}
3691
3692
3693/*
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003694 * The "raid5_align_endio" should check if the read succeeded and if it
3695 * did, call bio_endio on the original bio (having bio_put the new bio
3696 * first).
3697 * If the read failed..
3698 */
NeilBrown6712ecf2007-09-27 12:47:43 +02003699static void raid5_align_endio(struct bio *bi, int error)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003700{
3701 struct bio* raid_bi = bi->bi_private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003702 mddev_t *mddev;
3703 raid5_conf_t *conf;
3704 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3705 mdk_rdev_t *rdev;
3706
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003707 bio_put(bi);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003708
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003709 rdev = (void*)raid_bi->bi_next;
3710 raid_bi->bi_next = NULL;
NeilBrown2b7f2222010-03-25 16:06:03 +11003711 mddev = rdev->mddev;
3712 conf = mddev->private;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003713
3714 rdev_dec_pending(rdev, conf->mddev);
3715
3716 if (!error && uptodate) {
NeilBrown6712ecf2007-09-27 12:47:43 +02003717 bio_endio(raid_bi, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003718 if (atomic_dec_and_test(&conf->active_aligned_reads))
3719 wake_up(&conf->wait_for_stripe);
NeilBrown6712ecf2007-09-27 12:47:43 +02003720 return;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003721 }
3722
3723
Dan Williams45b42332007-07-09 11:56:43 -07003724 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003725
3726 add_bio_to_retry(raid_bi, conf);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003727}
3728
Neil Brown387bb172007-02-08 14:20:29 -08003729static int bio_fits_rdev(struct bio *bi)
3730{
Jens Axboe165125e2007-07-24 09:28:11 +02003731 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
Neil Brown387bb172007-02-08 14:20:29 -08003732
Martin K. Petersenae03bf62009-05-22 17:17:50 -04003733 if ((bi->bi_size>>9) > queue_max_sectors(q))
Neil Brown387bb172007-02-08 14:20:29 -08003734 return 0;
3735 blk_recount_segments(q, bi);
Martin K. Petersen8a783622010-02-26 00:20:39 -05003736 if (bi->bi_phys_segments > queue_max_segments(q))
Neil Brown387bb172007-02-08 14:20:29 -08003737 return 0;
3738
3739 if (q->merge_bvec_fn)
3740 /* it's too hard to apply the merge_bvec_fn at this stage,
3741 * just just give up
3742 */
3743 return 0;
3744
3745 return 1;
3746}
3747
3748
NeilBrown21a52c62010-04-01 15:02:13 +11003749static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003750{
NeilBrown070ec552009-06-16 16:54:21 +10003751 raid5_conf_t *conf = mddev->private;
NeilBrown8553fe7ec2009-12-14 12:49:47 +11003752 int dd_idx;
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003753 struct bio* align_bi;
3754 mdk_rdev_t *rdev;
3755
3756 if (!in_chunk_boundary(mddev, raid_bio)) {
Dan Williams45b42332007-07-09 11:56:43 -07003757 pr_debug("chunk_aligned_read : non aligned\n");
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003758 return 0;
3759 }
3760 /*
NeilBrown99c0fb52009-03-31 14:39:38 +11003761 * use bio_clone to make a copy of the bio
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003762 */
3763 align_bi = bio_clone(raid_bio, GFP_NOIO);
3764 if (!align_bi)
3765 return 0;
3766 /*
3767 * set bi_end_io to a new function, and set bi_private to the
3768 * original bio.
3769 */
3770 align_bi->bi_end_io = raid5_align_endio;
3771 align_bi->bi_private = raid_bio;
3772 /*
3773 * compute position
3774 */
NeilBrown112bf892009-03-31 14:39:38 +11003775 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3776 0,
NeilBrown911d4ee2009-03-31 14:39:38 +11003777 &dd_idx, NULL);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003778
3779 rcu_read_lock();
3780 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3781 if (rdev && test_bit(In_sync, &rdev->flags)) {
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003782 atomic_inc(&rdev->nr_pending);
3783 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003784 raid_bio->bi_next = (void*)rdev;
3785 align_bi->bi_bdev = rdev->bdev;
3786 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3787 align_bi->bi_sector += rdev->data_offset;
3788
Neil Brown387bb172007-02-08 14:20:29 -08003789 if (!bio_fits_rdev(align_bi)) {
3790 /* too big in some way */
3791 bio_put(align_bi);
3792 rdev_dec_pending(rdev, mddev);
3793 return 0;
3794 }
3795
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003796 spin_lock_irq(&conf->device_lock);
3797 wait_event_lock_irq(conf->wait_for_stripe,
3798 conf->quiesce == 0,
3799 conf->device_lock, /* nothing */);
3800 atomic_inc(&conf->active_aligned_reads);
3801 spin_unlock_irq(&conf->device_lock);
3802
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003803 generic_make_request(align_bi);
3804 return 1;
3805 } else {
3806 rcu_read_unlock();
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08003807 bio_put(align_bi);
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003808 return 0;
3809 }
3810}
3811
Dan Williams8b3e6cd2008-04-28 02:15:53 -07003812/* __get_priority_stripe - get the next stripe to process
3813 *
3814 * Full stripe writes are allowed to pass preread active stripes up until
3815 * the bypass_threshold is exceeded. In general the bypass_count
3816 * increments when the handle_list is handled before the hold_list; however, it
3817 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3818 * stripe with in flight i/o. The bypass_count will be reset when the
3819 * head of the hold_list has changed, i.e. the head was promoted to the
3820 * handle_list.
3821 */
3822static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3823{
3824 struct stripe_head *sh;
3825
3826 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3827 __func__,
3828 list_empty(&conf->handle_list) ? "empty" : "busy",
3829 list_empty(&conf->hold_list) ? "empty" : "busy",
3830 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3831
3832 if (!list_empty(&conf->handle_list)) {
3833 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3834
3835 if (list_empty(&conf->hold_list))
3836 conf->bypass_count = 0;
3837 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3838 if (conf->hold_list.next == conf->last_hold)
3839 conf->bypass_count++;
3840 else {
3841 conf->last_hold = conf->hold_list.next;
3842 conf->bypass_count -= conf->bypass_threshold;
3843 if (conf->bypass_count < 0)
3844 conf->bypass_count = 0;
3845 }
3846 }
3847 } else if (!list_empty(&conf->hold_list) &&
3848 ((conf->bypass_threshold &&
3849 conf->bypass_count > conf->bypass_threshold) ||
3850 atomic_read(&conf->pending_full_writes) == 0)) {
3851 sh = list_entry(conf->hold_list.next,
3852 typeof(*sh), lru);
3853 conf->bypass_count -= conf->bypass_threshold;
3854 if (conf->bypass_count < 0)
3855 conf->bypass_count = 0;
3856 } else
3857 return NULL;
3858
3859 list_del_init(&sh->lru);
3860 atomic_inc(&sh->count);
3861 BUG_ON(atomic_read(&sh->count) != 1);
3862 return sh;
3863}
Raz Ben-Jehuda(caro)f6796232006-12-10 02:20:46 -08003864
NeilBrown21a52c62010-04-01 15:02:13 +11003865static int make_request(mddev_t *mddev, struct bio * bi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003866{
NeilBrown070ec552009-06-16 16:54:21 +10003867 raid5_conf_t *conf = mddev->private;
NeilBrown911d4ee2009-03-31 14:39:38 +11003868 int dd_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003869 sector_t new_sector;
3870 sector_t logical_sector, last_sector;
3871 struct stripe_head *sh;
Jens Axboea3623572005-11-01 09:26:16 +01003872 const int rw = bio_data_dir(bi);
NeilBrown49077322010-03-25 16:20:56 +11003873 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003874
Jens Axboe1f98a132009-09-11 14:32:04 +02003875 if (unlikely(bio_rw_flagged(bi, BIO_RW_BARRIER))) {
NeilBrowna2826aa2009-12-14 12:49:49 +11003876 /* Drain all pending writes. We only really need
3877 * to ensure they have been submitted, but this is
3878 * easier.
3879 */
3880 mddev->pers->quiesce(mddev, 1);
3881 mddev->pers->quiesce(mddev, 0);
3882 md_barrier_request(mddev, bi);
NeilBrowne5dcdd82005-09-09 16:23:41 -07003883 return 0;
3884 }
3885
NeilBrown3d310eb2005-06-21 17:17:26 -07003886 md_write_start(mddev, bi);
NeilBrown06d91a52005-06-21 17:17:12 -07003887
NeilBrown802ba062006-12-13 00:34:13 -08003888 if (rw == READ &&
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003889 mddev->reshape_position == MaxSector &&
NeilBrown21a52c62010-04-01 15:02:13 +11003890 chunk_aligned_read(mddev,bi))
NeilBrown99c0fb52009-03-31 14:39:38 +11003891 return 0;
Raz Ben-Jehuda(caro)52488612006-12-10 02:20:48 -08003892
Linus Torvalds1da177e2005-04-16 15:20:36 -07003893 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3894 last_sector = bi->bi_sector + (bi->bi_size>>9);
3895 bi->bi_next = NULL;
3896 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
NeilBrown06d91a52005-06-21 17:17:12 -07003897
Linus Torvalds1da177e2005-04-16 15:20:36 -07003898 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3899 DEFINE_WAIT(w);
NeilBrown16a53ec2006-06-26 00:27:38 -07003900 int disks, data_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003901 int previous;
NeilBrownb578d552006-03-27 01:18:12 -08003902
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003903 retry:
NeilBrownb5663ba2009-03-31 14:39:38 +11003904 previous = 0;
NeilBrownb0f9ec02009-03-31 15:27:18 +11003905 disks = conf->raid_disks;
NeilBrownb578d552006-03-27 01:18:12 -08003906 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003907 if (unlikely(conf->reshape_progress != MaxSector)) {
NeilBrownfef9c612009-03-31 15:16:46 +11003908 /* spinlock is needed as reshape_progress may be
NeilBrowndf8e7f72006-03-27 01:18:15 -08003909 * 64bit on a 32bit platform, and so it might be
3910 * possible to see a half-updated value
NeilBrownfef9c612009-03-31 15:16:46 +11003911 * Ofcourse reshape_progress could change after
NeilBrowndf8e7f72006-03-27 01:18:15 -08003912 * the lock is dropped, so once we get a reference
3913 * to the stripe that we think it is, we will have
3914 * to check again.
3915 */
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003916 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11003917 if (mddev->delta_disks < 0
3918 ? logical_sector < conf->reshape_progress
3919 : logical_sector >= conf->reshape_progress) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003920 disks = conf->previous_raid_disks;
NeilBrownb5663ba2009-03-31 14:39:38 +11003921 previous = 1;
3922 } else {
NeilBrownfef9c612009-03-31 15:16:46 +11003923 if (mddev->delta_disks < 0
3924 ? logical_sector < conf->reshape_safe
3925 : logical_sector >= conf->reshape_safe) {
NeilBrownb578d552006-03-27 01:18:12 -08003926 spin_unlock_irq(&conf->device_lock);
3927 schedule();
3928 goto retry;
3929 }
3930 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003931 spin_unlock_irq(&conf->device_lock);
3932 }
NeilBrown16a53ec2006-06-26 00:27:38 -07003933 data_disks = disks - conf->max_degraded;
3934
NeilBrown112bf892009-03-31 14:39:38 +11003935 new_sector = raid5_compute_sector(conf, logical_sector,
3936 previous,
NeilBrown911d4ee2009-03-31 14:39:38 +11003937 &dd_idx, NULL);
NeilBrown0c55e022010-05-03 14:09:02 +10003938 pr_debug("raid456: make_request, sector %llu logical %llu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07003939 (unsigned long long)new_sector,
3940 (unsigned long long)logical_sector);
3941
NeilBrownb5663ba2009-03-31 14:39:38 +11003942 sh = get_active_stripe(conf, new_sector, previous,
NeilBrowna8c906c2009-06-09 14:39:59 +10003943 (bi->bi_rw&RWA_MASK), 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003944 if (sh) {
NeilBrownb0f9ec02009-03-31 15:27:18 +11003945 if (unlikely(previous)) {
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003946 /* expansion might have moved on while waiting for a
NeilBrowndf8e7f72006-03-27 01:18:15 -08003947 * stripe, so we must do the range check again.
3948 * Expansion could still move past after this
3949 * test, but as we are holding a reference to
3950 * 'sh', we know that if that happens,
3951 * STRIPE_EXPANDING will get set and the expansion
3952 * won't proceed until we finish with the stripe.
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003953 */
3954 int must_retry = 0;
3955 spin_lock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11003956 if (mddev->delta_disks < 0
3957 ? logical_sector >= conf->reshape_progress
3958 : logical_sector < conf->reshape_progress)
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003959 /* mismatch, need to try again */
3960 must_retry = 1;
3961 spin_unlock_irq(&conf->device_lock);
3962 if (must_retry) {
3963 release_stripe(sh);
Dan Williams7a3ab902009-06-16 16:00:33 -07003964 schedule();
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003965 goto retry;
3966 }
3967 }
NeilBrowne62e58a2009-07-01 13:15:35 +10003968
NeilBrowna5c308d2009-07-01 13:15:35 +10003969 if (bio_data_dir(bi) == WRITE &&
3970 logical_sector >= mddev->suspend_lo &&
NeilBrowne464eaf2006-03-27 01:18:14 -08003971 logical_sector < mddev->suspend_hi) {
3972 release_stripe(sh);
NeilBrowne62e58a2009-07-01 13:15:35 +10003973 /* As the suspend_* range is controlled by
3974 * userspace, we want an interruptible
3975 * wait.
3976 */
3977 flush_signals(current);
3978 prepare_to_wait(&conf->wait_for_overlap,
3979 &w, TASK_INTERRUPTIBLE);
3980 if (logical_sector >= mddev->suspend_lo &&
3981 logical_sector < mddev->suspend_hi)
3982 schedule();
NeilBrowne464eaf2006-03-27 01:18:14 -08003983 goto retry;
3984 }
NeilBrown7ecaa1e2006-03-27 01:18:08 -08003985
3986 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3987 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3988 /* Stripe is busy expanding or
3989 * add failed due to overlap. Flush everything
Linus Torvalds1da177e2005-04-16 15:20:36 -07003990 * and wait a while
3991 */
3992 raid5_unplug_device(mddev->queue);
3993 release_stripe(sh);
3994 schedule();
3995 goto retry;
3996 }
3997 finish_wait(&conf->wait_for_overlap, &w);
NeilBrown6ed30032008-02-06 01:40:00 -08003998 set_bit(STRIPE_HANDLE, &sh->state);
3999 clear_bit(STRIPE_DELAYED, &sh->state);
NeilBrown729a1862009-12-14 12:49:50 +11004000 if (mddev->barrier &&
4001 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4002 atomic_inc(&conf->preread_active_stripes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004003 release_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004004 } else {
4005 /* cannot get stripe for read-ahead, just give-up */
4006 clear_bit(BIO_UPTODATE, &bi->bi_flags);
4007 finish_wait(&conf->wait_for_overlap, &w);
4008 break;
4009 }
4010
4011 }
4012 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02004013 remaining = raid5_dec_bi_phys_segments(bi);
NeilBrownf6344752006-03-27 01:18:17 -08004014 spin_unlock_irq(&conf->device_lock);
4015 if (remaining == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004016
NeilBrown16a53ec2006-06-26 00:27:38 -07004017 if ( rw == WRITE )
Linus Torvalds1da177e2005-04-16 15:20:36 -07004018 md_write_end(mddev);
NeilBrown6712ecf2007-09-27 12:47:43 +02004019
Neil Brown0e13fe232008-06-28 08:31:20 +10004020 bio_endio(bi, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004021 }
NeilBrown729a1862009-12-14 12:49:50 +11004022
4023 if (mddev->barrier) {
4024 /* We need to wait for the stripes to all be handled.
4025 * So: wait for preread_active_stripes to drop to 0.
4026 */
4027 wait_event(mddev->thread->wqueue,
4028 atomic_read(&conf->preread_active_stripes) == 0);
4029 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004030 return 0;
4031}
4032
Dan Williamsb522adc2009-03-31 15:00:31 +11004033static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
4034
NeilBrown52c03292006-06-26 00:27:43 -07004035static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004036{
NeilBrown52c03292006-06-26 00:27:43 -07004037 /* reshaping is quite different to recovery/resync so it is
4038 * handled quite separately ... here.
4039 *
4040 * On each call to sync_request, we gather one chunk worth of
4041 * destination stripes and flag them as expanding.
4042 * Then we find all the source stripes and request reads.
4043 * As the reads complete, handle_stripe will copy the data
4044 * into the destination stripe and release that stripe.
4045 */
H Hartley Sweeten7b928132010-03-08 16:02:40 +11004046 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004047 struct stripe_head *sh;
NeilBrownccfcc3c2006-03-27 01:18:09 -08004048 sector_t first_sector, last_sector;
NeilBrownf4168852007-02-28 20:11:53 -08004049 int raid_disks = conf->previous_raid_disks;
4050 int data_disks = raid_disks - conf->max_degraded;
4051 int new_data_disks = conf->raid_disks - conf->max_degraded;
NeilBrown52c03292006-06-26 00:27:43 -07004052 int i;
4053 int dd_idx;
NeilBrownc8f517c2009-03-31 15:28:40 +11004054 sector_t writepos, readpos, safepos;
NeilBrownec32a2b2009-03-31 15:17:38 +11004055 sector_t stripe_addr;
NeilBrown7a661382009-03-31 15:21:40 +11004056 int reshape_sectors;
NeilBrownab69ae12009-03-31 15:26:47 +11004057 struct list_head stripes;
NeilBrown52c03292006-06-26 00:27:43 -07004058
NeilBrownfef9c612009-03-31 15:16:46 +11004059 if (sector_nr == 0) {
4060 /* If restarting in the middle, skip the initial sectors */
4061 if (mddev->delta_disks < 0 &&
4062 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4063 sector_nr = raid5_size(mddev, 0, 0)
4064 - conf->reshape_progress;
NeilBrowna6397552009-08-13 10:13:00 +10004065 } else if (mddev->delta_disks >= 0 &&
NeilBrownfef9c612009-03-31 15:16:46 +11004066 conf->reshape_progress > 0)
4067 sector_nr = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08004068 sector_div(sector_nr, new_data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11004069 if (sector_nr) {
NeilBrown8dee7212009-11-06 14:59:29 +11004070 mddev->curr_resync_completed = sector_nr;
4071 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrownfef9c612009-03-31 15:16:46 +11004072 *skipped = 1;
4073 return sector_nr;
4074 }
NeilBrown52c03292006-06-26 00:27:43 -07004075 }
4076
NeilBrown7a661382009-03-31 15:21:40 +11004077 /* We need to process a full chunk at a time.
4078 * If old and new chunk sizes differ, we need to process the
4079 * largest of these
4080 */
Andre Noll664e7c42009-06-18 08:45:27 +10004081 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4082 reshape_sectors = mddev->new_chunk_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11004083 else
Andre Noll9d8f0362009-06-18 08:45:01 +10004084 reshape_sectors = mddev->chunk_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11004085
NeilBrown52c03292006-06-26 00:27:43 -07004086 /* we update the metadata when there is more than 3Meg
4087 * in the block range (that is rather arbitrary, should
4088 * probably be time based) or when the data about to be
4089 * copied would over-write the source of the data at
4090 * the front of the range.
NeilBrownfef9c612009-03-31 15:16:46 +11004091 * i.e. one new_stripe along from reshape_progress new_maps
4092 * to after where reshape_safe old_maps to
NeilBrown52c03292006-06-26 00:27:43 -07004093 */
NeilBrownfef9c612009-03-31 15:16:46 +11004094 writepos = conf->reshape_progress;
NeilBrownf4168852007-02-28 20:11:53 -08004095 sector_div(writepos, new_data_disks);
NeilBrownc8f517c2009-03-31 15:28:40 +11004096 readpos = conf->reshape_progress;
4097 sector_div(readpos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11004098 safepos = conf->reshape_safe;
NeilBrownf4168852007-02-28 20:11:53 -08004099 sector_div(safepos, data_disks);
NeilBrownfef9c612009-03-31 15:16:46 +11004100 if (mddev->delta_disks < 0) {
NeilBrowned37d832009-05-27 21:39:05 +10004101 writepos -= min_t(sector_t, reshape_sectors, writepos);
NeilBrownc8f517c2009-03-31 15:28:40 +11004102 readpos += reshape_sectors;
NeilBrown7a661382009-03-31 15:21:40 +11004103 safepos += reshape_sectors;
NeilBrownfef9c612009-03-31 15:16:46 +11004104 } else {
NeilBrown7a661382009-03-31 15:21:40 +11004105 writepos += reshape_sectors;
NeilBrowned37d832009-05-27 21:39:05 +10004106 readpos -= min_t(sector_t, reshape_sectors, readpos);
4107 safepos -= min_t(sector_t, reshape_sectors, safepos);
NeilBrownfef9c612009-03-31 15:16:46 +11004108 }
NeilBrown52c03292006-06-26 00:27:43 -07004109
NeilBrownc8f517c2009-03-31 15:28:40 +11004110 /* 'writepos' is the most advanced device address we might write.
4111 * 'readpos' is the least advanced device address we might read.
4112 * 'safepos' is the least address recorded in the metadata as having
4113 * been reshaped.
4114 * If 'readpos' is behind 'writepos', then there is no way that we can
4115 * ensure safety in the face of a crash - that must be done by userspace
4116 * making a backup of the data. So in that case there is no particular
4117 * rush to update metadata.
4118 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4119 * update the metadata to advance 'safepos' to match 'readpos' so that
4120 * we can be safe in the event of a crash.
4121 * So we insist on updating metadata if safepos is behind writepos and
4122 * readpos is beyond writepos.
4123 * In any case, update the metadata every 10 seconds.
4124 * Maybe that number should be configurable, but I'm not sure it is
4125 * worth it.... maybe it could be a multiple of safemode_delay???
4126 */
NeilBrownfef9c612009-03-31 15:16:46 +11004127 if ((mddev->delta_disks < 0
NeilBrownc8f517c2009-03-31 15:28:40 +11004128 ? (safepos > writepos && readpos < writepos)
4129 : (safepos < writepos && readpos > writepos)) ||
4130 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
NeilBrown52c03292006-06-26 00:27:43 -07004131 /* Cannot proceed until we've updated the superblock... */
4132 wait_event(conf->wait_for_overlap,
4133 atomic_read(&conf->reshape_stripes)==0);
NeilBrownfef9c612009-03-31 15:16:46 +11004134 mddev->reshape_position = conf->reshape_progress;
NeilBrownacb180b2009-04-14 16:28:34 +10004135 mddev->curr_resync_completed = mddev->curr_resync;
NeilBrownc8f517c2009-03-31 15:28:40 +11004136 conf->reshape_checkpoint = jiffies;
NeilBrown850b2b42006-10-03 01:15:46 -07004137 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrown52c03292006-06-26 00:27:43 -07004138 md_wakeup_thread(mddev->thread);
NeilBrown850b2b42006-10-03 01:15:46 -07004139 wait_event(mddev->sb_wait, mddev->flags == 0 ||
NeilBrown52c03292006-06-26 00:27:43 -07004140 kthread_should_stop());
4141 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11004142 conf->reshape_safe = mddev->reshape_position;
NeilBrown52c03292006-06-26 00:27:43 -07004143 spin_unlock_irq(&conf->device_lock);
4144 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10004145 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrown52c03292006-06-26 00:27:43 -07004146 }
4147
NeilBrownec32a2b2009-03-31 15:17:38 +11004148 if (mddev->delta_disks < 0) {
4149 BUG_ON(conf->reshape_progress == 0);
4150 stripe_addr = writepos;
4151 BUG_ON((mddev->dev_sectors &
NeilBrown7a661382009-03-31 15:21:40 +11004152 ~((sector_t)reshape_sectors - 1))
4153 - reshape_sectors - stripe_addr
NeilBrownec32a2b2009-03-31 15:17:38 +11004154 != sector_nr);
4155 } else {
NeilBrown7a661382009-03-31 15:21:40 +11004156 BUG_ON(writepos != sector_nr + reshape_sectors);
NeilBrownec32a2b2009-03-31 15:17:38 +11004157 stripe_addr = sector_nr;
4158 }
NeilBrownab69ae12009-03-31 15:26:47 +11004159 INIT_LIST_HEAD(&stripes);
NeilBrown7a661382009-03-31 15:21:40 +11004160 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
NeilBrown52c03292006-06-26 00:27:43 -07004161 int j;
NeilBrowna9f326e2009-09-23 18:06:41 +10004162 int skipped_disk = 0;
NeilBrowna8c906c2009-06-09 14:39:59 +10004163 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
NeilBrown52c03292006-06-26 00:27:43 -07004164 set_bit(STRIPE_EXPANDING, &sh->state);
4165 atomic_inc(&conf->reshape_stripes);
4166 /* If any of this stripe is beyond the end of the old
4167 * array, then we need to zero those blocks
4168 */
4169 for (j=sh->disks; j--;) {
4170 sector_t s;
4171 if (j == sh->pd_idx)
4172 continue;
NeilBrownf4168852007-02-28 20:11:53 -08004173 if (conf->level == 6 &&
NeilBrownd0dabf72009-03-31 14:39:38 +11004174 j == sh->qd_idx)
NeilBrownf4168852007-02-28 20:11:53 -08004175 continue;
NeilBrown784052e2009-03-31 15:19:07 +11004176 s = compute_blocknr(sh, j, 0);
Dan Williamsb522adc2009-03-31 15:00:31 +11004177 if (s < raid5_size(mddev, 0, 0)) {
NeilBrowna9f326e2009-09-23 18:06:41 +10004178 skipped_disk = 1;
NeilBrown52c03292006-06-26 00:27:43 -07004179 continue;
4180 }
4181 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4182 set_bit(R5_Expanded, &sh->dev[j].flags);
4183 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4184 }
NeilBrowna9f326e2009-09-23 18:06:41 +10004185 if (!skipped_disk) {
NeilBrown52c03292006-06-26 00:27:43 -07004186 set_bit(STRIPE_EXPAND_READY, &sh->state);
4187 set_bit(STRIPE_HANDLE, &sh->state);
4188 }
NeilBrownab69ae12009-03-31 15:26:47 +11004189 list_add(&sh->lru, &stripes);
NeilBrown52c03292006-06-26 00:27:43 -07004190 }
4191 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11004192 if (mddev->delta_disks < 0)
NeilBrown7a661382009-03-31 15:21:40 +11004193 conf->reshape_progress -= reshape_sectors * new_data_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11004194 else
NeilBrown7a661382009-03-31 15:21:40 +11004195 conf->reshape_progress += reshape_sectors * new_data_disks;
NeilBrown52c03292006-06-26 00:27:43 -07004196 spin_unlock_irq(&conf->device_lock);
4197 /* Ok, those stripe are ready. We can start scheduling
4198 * reads on the source stripes.
4199 * The source stripes are determined by mapping the first and last
4200 * block on the destination stripes.
4201 */
NeilBrown52c03292006-06-26 00:27:43 -07004202 first_sector =
NeilBrownec32a2b2009-03-31 15:17:38 +11004203 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
NeilBrown911d4ee2009-03-31 14:39:38 +11004204 1, &dd_idx, NULL);
NeilBrown52c03292006-06-26 00:27:43 -07004205 last_sector =
NeilBrown0e6e0272009-06-09 16:32:22 +10004206 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
Andre Noll09c9e5f2009-06-18 08:45:55 +10004207 * new_data_disks - 1),
NeilBrown911d4ee2009-03-31 14:39:38 +11004208 1, &dd_idx, NULL);
Andre Noll58c0fed2009-03-31 14:33:13 +11004209 if (last_sector >= mddev->dev_sectors)
4210 last_sector = mddev->dev_sectors - 1;
NeilBrown52c03292006-06-26 00:27:43 -07004211 while (first_sector <= last_sector) {
NeilBrowna8c906c2009-06-09 14:39:59 +10004212 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
NeilBrown52c03292006-06-26 00:27:43 -07004213 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4214 set_bit(STRIPE_HANDLE, &sh->state);
4215 release_stripe(sh);
4216 first_sector += STRIPE_SECTORS;
4217 }
NeilBrownab69ae12009-03-31 15:26:47 +11004218 /* Now that the sources are clearly marked, we can release
4219 * the destination stripes
4220 */
4221 while (!list_empty(&stripes)) {
4222 sh = list_entry(stripes.next, struct stripe_head, lru);
4223 list_del_init(&sh->lru);
4224 release_stripe(sh);
4225 }
NeilBrownc6207272008-02-06 01:39:52 -08004226 /* If this takes us to the resync_max point where we have to pause,
4227 * then we need to write out the superblock.
4228 */
NeilBrown7a661382009-03-31 15:21:40 +11004229 sector_nr += reshape_sectors;
NeilBrownc03f6a12009-04-17 11:06:30 +10004230 if ((sector_nr - mddev->curr_resync_completed) * 2
4231 >= mddev->resync_max - mddev->curr_resync_completed) {
NeilBrownc6207272008-02-06 01:39:52 -08004232 /* Cannot proceed until we've updated the superblock... */
4233 wait_event(conf->wait_for_overlap,
4234 atomic_read(&conf->reshape_stripes) == 0);
NeilBrownfef9c612009-03-31 15:16:46 +11004235 mddev->reshape_position = conf->reshape_progress;
NeilBrown48606a92009-06-18 09:14:12 +10004236 mddev->curr_resync_completed = mddev->curr_resync + reshape_sectors;
NeilBrownc8f517c2009-03-31 15:28:40 +11004237 conf->reshape_checkpoint = jiffies;
NeilBrownc6207272008-02-06 01:39:52 -08004238 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4239 md_wakeup_thread(mddev->thread);
4240 wait_event(mddev->sb_wait,
4241 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4242 || kthread_should_stop());
4243 spin_lock_irq(&conf->device_lock);
NeilBrownfef9c612009-03-31 15:16:46 +11004244 conf->reshape_safe = mddev->reshape_position;
NeilBrownc6207272008-02-06 01:39:52 -08004245 spin_unlock_irq(&conf->device_lock);
4246 wake_up(&conf->wait_for_overlap);
NeilBrownacb180b2009-04-14 16:28:34 +10004247 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
NeilBrownc6207272008-02-06 01:39:52 -08004248 }
NeilBrown7a661382009-03-31 15:21:40 +11004249 return reshape_sectors;
NeilBrown52c03292006-06-26 00:27:43 -07004250}
4251
4252/* FIXME go_faster isn't used */
4253static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
4254{
H Hartley Sweeten7b928132010-03-08 16:02:40 +11004255 raid5_conf_t *conf = mddev->private;
NeilBrown52c03292006-06-26 00:27:43 -07004256 struct stripe_head *sh;
Andre Noll58c0fed2009-03-31 14:33:13 +11004257 sector_t max_sector = mddev->dev_sectors;
NeilBrown72626682005-09-09 16:23:54 -07004258 int sync_blocks;
NeilBrown16a53ec2006-06-26 00:27:38 -07004259 int still_degraded = 0;
4260 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004261
NeilBrown72626682005-09-09 16:23:54 -07004262 if (sector_nr >= max_sector) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004263 /* just being told to finish up .. nothing much to do */
4264 unplug_slaves(mddev);
NeilBrowncea9c222009-03-31 15:15:05 +11004265
NeilBrown29269552006-03-27 01:18:10 -08004266 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4267 end_reshape(conf);
4268 return 0;
4269 }
NeilBrown72626682005-09-09 16:23:54 -07004270
4271 if (mddev->curr_resync < max_sector) /* aborted */
4272 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4273 &sync_blocks, 1);
NeilBrown16a53ec2006-06-26 00:27:38 -07004274 else /* completed sync */
NeilBrown72626682005-09-09 16:23:54 -07004275 conf->fullsync = 0;
4276 bitmap_close_sync(mddev->bitmap);
4277
Linus Torvalds1da177e2005-04-16 15:20:36 -07004278 return 0;
4279 }
NeilBrownccfcc3c2006-03-27 01:18:09 -08004280
NeilBrown64bd6602009-08-03 10:59:58 +10004281 /* Allow raid5_quiesce to complete */
4282 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4283
NeilBrown52c03292006-06-26 00:27:43 -07004284 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4285 return reshape_request(mddev, sector_nr, skipped);
NeilBrownf6705572006-03-27 01:18:11 -08004286
NeilBrownc6207272008-02-06 01:39:52 -08004287 /* No need to check resync_max as we never do more than one
4288 * stripe, and as resync_max will always be on a chunk boundary,
4289 * if the check in md_do_sync didn't fire, there is no chance
4290 * of overstepping resync_max here
4291 */
4292
NeilBrown16a53ec2006-06-26 00:27:38 -07004293 /* if there is too many failed drives and we are trying
Linus Torvalds1da177e2005-04-16 15:20:36 -07004294 * to resync, then assert that we are finished, because there is
4295 * nothing we can do.
4296 */
NeilBrown3285edf2006-06-26 00:27:55 -07004297 if (mddev->degraded >= conf->max_degraded &&
NeilBrown16a53ec2006-06-26 00:27:38 -07004298 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
Andre Noll58c0fed2009-03-31 14:33:13 +11004299 sector_t rv = mddev->dev_sectors - sector_nr;
NeilBrown57afd892005-06-21 17:17:13 -07004300 *skipped = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004301 return rv;
4302 }
NeilBrown72626682005-09-09 16:23:54 -07004303 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
NeilBrown3855ad92005-11-08 21:39:38 -08004304 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
NeilBrown72626682005-09-09 16:23:54 -07004305 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4306 /* we can skip this block, and probably more */
4307 sync_blocks /= STRIPE_SECTORS;
4308 *skipped = 1;
4309 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4310 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004311
NeilBrownb47490c2008-02-06 01:39:50 -08004312
4313 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4314
NeilBrowna8c906c2009-06-09 14:39:59 +10004315 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004316 if (sh == NULL) {
NeilBrowna8c906c2009-06-09 14:39:59 +10004317 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004318 /* make sure we don't swamp the stripe cache if someone else
NeilBrown16a53ec2006-06-26 00:27:38 -07004319 * is trying to get access
Linus Torvalds1da177e2005-04-16 15:20:36 -07004320 */
Nishanth Aravamudan66c006a2005-11-07 01:01:17 -08004321 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004322 }
NeilBrown16a53ec2006-06-26 00:27:38 -07004323 /* Need to check if array will still be degraded after recovery/resync
4324 * We don't need to check the 'failed' flag as when that gets set,
4325 * recovery aborts.
4326 */
NeilBrownf001a702009-06-09 14:30:31 +10004327 for (i = 0; i < conf->raid_disks; i++)
NeilBrown16a53ec2006-06-26 00:27:38 -07004328 if (conf->disks[i].rdev == NULL)
4329 still_degraded = 1;
4330
4331 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4332
4333 spin_lock(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004334 set_bit(STRIPE_SYNCING, &sh->state);
4335 clear_bit(STRIPE_INSYNC, &sh->state);
4336 spin_unlock(&sh->lock);
4337
NeilBrown14425772009-10-16 15:55:25 +11004338 handle_stripe(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004339 release_stripe(sh);
4340
4341 return STRIPE_SECTORS;
4342}
4343
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004344static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4345{
4346 /* We may not be able to submit a whole bio at once as there
4347 * may not be enough stripe_heads available.
4348 * We cannot pre-allocate enough stripe_heads as we may need
4349 * more than exist in the cache (if we allow ever large chunks).
4350 * So we do one stripe head at a time and record in
4351 * ->bi_hw_segments how many have been done.
4352 *
4353 * We *know* that this entire raid_bio is in one chunk, so
4354 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4355 */
4356 struct stripe_head *sh;
NeilBrown911d4ee2009-03-31 14:39:38 +11004357 int dd_idx;
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004358 sector_t sector, logical_sector, last_sector;
4359 int scnt = 0;
4360 int remaining;
4361 int handled = 0;
4362
4363 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
NeilBrown112bf892009-03-31 14:39:38 +11004364 sector = raid5_compute_sector(conf, logical_sector,
NeilBrown911d4ee2009-03-31 14:39:38 +11004365 0, &dd_idx, NULL);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004366 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4367
4368 for (; logical_sector < last_sector;
Neil Brown387bb172007-02-08 14:20:29 -08004369 logical_sector += STRIPE_SECTORS,
4370 sector += STRIPE_SECTORS,
4371 scnt++) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004372
Jens Axboe960e7392008-08-15 10:41:18 +02004373 if (scnt < raid5_bi_hw_segments(raid_bio))
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004374 /* already done this stripe */
4375 continue;
4376
NeilBrowna8c906c2009-06-09 14:39:59 +10004377 sh = get_active_stripe(conf, sector, 0, 1, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004378
4379 if (!sh) {
4380 /* failed to get a stripe - must wait */
Jens Axboe960e7392008-08-15 10:41:18 +02004381 raid5_set_bi_hw_segments(raid_bio, scnt);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004382 conf->retry_read_aligned = raid_bio;
4383 return handled;
4384 }
4385
4386 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
Neil Brown387bb172007-02-08 14:20:29 -08004387 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4388 release_stripe(sh);
Jens Axboe960e7392008-08-15 10:41:18 +02004389 raid5_set_bi_hw_segments(raid_bio, scnt);
Neil Brown387bb172007-02-08 14:20:29 -08004390 conf->retry_read_aligned = raid_bio;
4391 return handled;
4392 }
4393
Dan Williams36d1c642009-07-14 11:48:22 -07004394 handle_stripe(sh);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004395 release_stripe(sh);
4396 handled++;
4397 }
4398 spin_lock_irq(&conf->device_lock);
Jens Axboe960e7392008-08-15 10:41:18 +02004399 remaining = raid5_dec_bi_phys_segments(raid_bio);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004400 spin_unlock_irq(&conf->device_lock);
Neil Brown0e13fe232008-06-28 08:31:20 +10004401 if (remaining == 0)
4402 bio_endio(raid_bio, 0);
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004403 if (atomic_dec_and_test(&conf->active_aligned_reads))
4404 wake_up(&conf->wait_for_stripe);
4405 return handled;
4406}
4407
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004408
Linus Torvalds1da177e2005-04-16 15:20:36 -07004409/*
4410 * This is our raid5 kernel thread.
4411 *
4412 * We scan the hash table for stripes which can be handled now.
4413 * During the scan, completed stripes are saved for us by the interrupt
4414 * handler, so that they will not have to wait for our next wakeup.
4415 */
NeilBrown6ed30032008-02-06 01:40:00 -08004416static void raid5d(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004417{
4418 struct stripe_head *sh;
NeilBrown070ec552009-06-16 16:54:21 +10004419 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004420 int handled;
4421
Dan Williams45b42332007-07-09 11:56:43 -07004422 pr_debug("+++ raid5d active\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004423
4424 md_check_recovery(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004425
4426 handled = 0;
4427 spin_lock_irq(&conf->device_lock);
4428 while (1) {
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004429 struct bio *bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004430
NeilBrownae3c20c2006-07-10 04:44:17 -07004431 if (conf->seq_flush != conf->seq_write) {
NeilBrown72626682005-09-09 16:23:54 -07004432 int seq = conf->seq_flush;
NeilBrown700e4322005-11-28 13:44:10 -08004433 spin_unlock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004434 bitmap_unplug(mddev->bitmap);
NeilBrown700e4322005-11-28 13:44:10 -08004435 spin_lock_irq(&conf->device_lock);
NeilBrown72626682005-09-09 16:23:54 -07004436 conf->seq_write = seq;
4437 activate_bit_delay(conf);
4438 }
4439
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08004440 while ((bio = remove_bio_from_retry(conf))) {
4441 int ok;
4442 spin_unlock_irq(&conf->device_lock);
4443 ok = retry_aligned_read(conf, bio);
4444 spin_lock_irq(&conf->device_lock);
4445 if (!ok)
4446 break;
4447 handled++;
4448 }
4449
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004450 sh = __get_priority_stripe(conf);
4451
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004452 if (!sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004453 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004454 spin_unlock_irq(&conf->device_lock);
4455
4456 handled++;
Dan Williams417b8d42009-10-16 16:25:22 +11004457 handle_stripe(sh);
4458 release_stripe(sh);
4459 cond_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004460
4461 spin_lock_irq(&conf->device_lock);
4462 }
Dan Williams45b42332007-07-09 11:56:43 -07004463 pr_debug("%d stripes handled\n", handled);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004464
4465 spin_unlock_irq(&conf->device_lock);
4466
Dan Williamsc9f21aa2008-07-23 12:05:51 -07004467 async_tx_issue_pending_all();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004468 unplug_slaves(mddev);
4469
Dan Williams45b42332007-07-09 11:56:43 -07004470 pr_debug("--- raid5d inactive\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004471}
4472
NeilBrown3f294f42005-11-08 21:39:25 -08004473static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004474raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004475{
NeilBrown070ec552009-06-16 16:54:21 +10004476 raid5_conf_t *conf = mddev->private;
NeilBrown96de1e62005-11-08 21:39:39 -08004477 if (conf)
4478 return sprintf(page, "%d\n", conf->max_nr_stripes);
4479 else
4480 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004481}
4482
4483static ssize_t
NeilBrown007583c2005-11-08 21:39:30 -08004484raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
NeilBrown3f294f42005-11-08 21:39:25 -08004485{
NeilBrown070ec552009-06-16 16:54:21 +10004486 raid5_conf_t *conf = mddev->private;
Dan Williams4ef197d82008-04-28 02:15:54 -07004487 unsigned long new;
Dan Williamsb5470dc2008-06-27 21:44:04 -07004488 int err;
4489
NeilBrown3f294f42005-11-08 21:39:25 -08004490 if (len >= PAGE_SIZE)
4491 return -EINVAL;
NeilBrown96de1e62005-11-08 21:39:39 -08004492 if (!conf)
4493 return -ENODEV;
NeilBrown3f294f42005-11-08 21:39:25 -08004494
Dan Williams4ef197d82008-04-28 02:15:54 -07004495 if (strict_strtoul(page, 10, &new))
NeilBrown3f294f42005-11-08 21:39:25 -08004496 return -EINVAL;
4497 if (new <= 16 || new > 32768)
4498 return -EINVAL;
4499 while (new < conf->max_nr_stripes) {
4500 if (drop_one_stripe(conf))
4501 conf->max_nr_stripes--;
4502 else
4503 break;
4504 }
Dan Williamsb5470dc2008-06-27 21:44:04 -07004505 err = md_allow_write(mddev);
4506 if (err)
4507 return err;
NeilBrown3f294f42005-11-08 21:39:25 -08004508 while (new > conf->max_nr_stripes) {
4509 if (grow_one_stripe(conf))
4510 conf->max_nr_stripes++;
4511 else break;
4512 }
4513 return len;
4514}
NeilBrown007583c2005-11-08 21:39:30 -08004515
NeilBrown96de1e62005-11-08 21:39:39 -08004516static struct md_sysfs_entry
4517raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4518 raid5_show_stripe_cache_size,
4519 raid5_store_stripe_cache_size);
NeilBrown3f294f42005-11-08 21:39:25 -08004520
4521static ssize_t
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004522raid5_show_preread_threshold(mddev_t *mddev, char *page)
4523{
NeilBrown070ec552009-06-16 16:54:21 +10004524 raid5_conf_t *conf = mddev->private;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004525 if (conf)
4526 return sprintf(page, "%d\n", conf->bypass_threshold);
4527 else
4528 return 0;
4529}
4530
4531static ssize_t
4532raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4533{
NeilBrown070ec552009-06-16 16:54:21 +10004534 raid5_conf_t *conf = mddev->private;
Dan Williams4ef197d82008-04-28 02:15:54 -07004535 unsigned long new;
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004536 if (len >= PAGE_SIZE)
4537 return -EINVAL;
4538 if (!conf)
4539 return -ENODEV;
4540
Dan Williams4ef197d82008-04-28 02:15:54 -07004541 if (strict_strtoul(page, 10, &new))
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004542 return -EINVAL;
Dan Williams4ef197d82008-04-28 02:15:54 -07004543 if (new > conf->max_nr_stripes)
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004544 return -EINVAL;
4545 conf->bypass_threshold = new;
4546 return len;
4547}
4548
4549static struct md_sysfs_entry
4550raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4551 S_IRUGO | S_IWUSR,
4552 raid5_show_preread_threshold,
4553 raid5_store_preread_threshold);
4554
4555static ssize_t
NeilBrown96de1e62005-11-08 21:39:39 -08004556stripe_cache_active_show(mddev_t *mddev, char *page)
NeilBrown3f294f42005-11-08 21:39:25 -08004557{
NeilBrown070ec552009-06-16 16:54:21 +10004558 raid5_conf_t *conf = mddev->private;
NeilBrown96de1e62005-11-08 21:39:39 -08004559 if (conf)
4560 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4561 else
4562 return 0;
NeilBrown3f294f42005-11-08 21:39:25 -08004563}
4564
NeilBrown96de1e62005-11-08 21:39:39 -08004565static struct md_sysfs_entry
4566raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
NeilBrown3f294f42005-11-08 21:39:25 -08004567
NeilBrown007583c2005-11-08 21:39:30 -08004568static struct attribute *raid5_attrs[] = {
NeilBrown3f294f42005-11-08 21:39:25 -08004569 &raid5_stripecache_size.attr,
4570 &raid5_stripecache_active.attr,
Dan Williams8b3e6cd2008-04-28 02:15:53 -07004571 &raid5_preread_bypass_threshold.attr,
NeilBrown3f294f42005-11-08 21:39:25 -08004572 NULL,
4573};
NeilBrown007583c2005-11-08 21:39:30 -08004574static struct attribute_group raid5_attrs_group = {
4575 .name = NULL,
4576 .attrs = raid5_attrs,
NeilBrown3f294f42005-11-08 21:39:25 -08004577};
4578
Dan Williams80c3a6c2009-03-17 18:10:40 -07004579static sector_t
4580raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4581{
NeilBrown070ec552009-06-16 16:54:21 +10004582 raid5_conf_t *conf = mddev->private;
Dan Williams80c3a6c2009-03-17 18:10:40 -07004583
4584 if (!sectors)
4585 sectors = mddev->dev_sectors;
NeilBrown5e5e3e72009-10-16 16:35:30 +11004586 if (!raid_disks)
NeilBrown7ec05472009-03-31 15:10:36 +11004587 /* size is defined by the smallest of previous and new size */
NeilBrown5e5e3e72009-10-16 16:35:30 +11004588 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
Dan Williams80c3a6c2009-03-17 18:10:40 -07004589
Andre Noll9d8f0362009-06-18 08:45:01 +10004590 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
Andre Noll664e7c42009-06-18 08:45:27 +10004591 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
Dan Williams80c3a6c2009-03-17 18:10:40 -07004592 return sectors * (raid_disks - conf->max_degraded);
4593}
4594
Dan Williams36d1c642009-07-14 11:48:22 -07004595static void raid5_free_percpu(raid5_conf_t *conf)
4596{
4597 struct raid5_percpu *percpu;
4598 unsigned long cpu;
4599
4600 if (!conf->percpu)
4601 return;
4602
4603 get_online_cpus();
4604 for_each_possible_cpu(cpu) {
4605 percpu = per_cpu_ptr(conf->percpu, cpu);
4606 safe_put_page(percpu->spare_page);
Dan Williamsd6f38f32009-07-14 11:50:52 -07004607 kfree(percpu->scribble);
Dan Williams36d1c642009-07-14 11:48:22 -07004608 }
4609#ifdef CONFIG_HOTPLUG_CPU
4610 unregister_cpu_notifier(&conf->cpu_notify);
4611#endif
4612 put_online_cpus();
4613
4614 free_percpu(conf->percpu);
4615}
4616
Dan Williams95fc17a2009-07-31 12:39:15 +10004617static void free_conf(raid5_conf_t *conf)
4618{
4619 shrink_stripes(conf);
Dan Williams36d1c642009-07-14 11:48:22 -07004620 raid5_free_percpu(conf);
Dan Williams95fc17a2009-07-31 12:39:15 +10004621 kfree(conf->disks);
4622 kfree(conf->stripe_hashtbl);
4623 kfree(conf);
4624}
4625
Dan Williams36d1c642009-07-14 11:48:22 -07004626#ifdef CONFIG_HOTPLUG_CPU
4627static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
4628 void *hcpu)
4629{
4630 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify);
4631 long cpu = (long)hcpu;
4632 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
4633
4634 switch (action) {
4635 case CPU_UP_PREPARE:
4636 case CPU_UP_PREPARE_FROZEN:
Dan Williamsd6f38f32009-07-14 11:50:52 -07004637 if (conf->level == 6 && !percpu->spare_page)
Dan Williams36d1c642009-07-14 11:48:22 -07004638 percpu->spare_page = alloc_page(GFP_KERNEL);
Dan Williamsd6f38f32009-07-14 11:50:52 -07004639 if (!percpu->scribble)
4640 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4641
4642 if (!percpu->scribble ||
4643 (conf->level == 6 && !percpu->spare_page)) {
4644 safe_put_page(percpu->spare_page);
4645 kfree(percpu->scribble);
Dan Williams36d1c642009-07-14 11:48:22 -07004646 pr_err("%s: failed memory allocation for cpu%ld\n",
4647 __func__, cpu);
Akinobu Mita55af6bb2010-05-26 14:43:35 -07004648 return notifier_from_errno(-ENOMEM);
Dan Williams36d1c642009-07-14 11:48:22 -07004649 }
4650 break;
4651 case CPU_DEAD:
4652 case CPU_DEAD_FROZEN:
4653 safe_put_page(percpu->spare_page);
Dan Williamsd6f38f32009-07-14 11:50:52 -07004654 kfree(percpu->scribble);
Dan Williams36d1c642009-07-14 11:48:22 -07004655 percpu->spare_page = NULL;
Dan Williamsd6f38f32009-07-14 11:50:52 -07004656 percpu->scribble = NULL;
Dan Williams36d1c642009-07-14 11:48:22 -07004657 break;
4658 default:
4659 break;
4660 }
4661 return NOTIFY_OK;
4662}
4663#endif
4664
4665static int raid5_alloc_percpu(raid5_conf_t *conf)
4666{
4667 unsigned long cpu;
4668 struct page *spare_page;
Tejun Heoa29d8b82010-02-02 14:39:15 +09004669 struct raid5_percpu __percpu *allcpus;
Dan Williamsd6f38f32009-07-14 11:50:52 -07004670 void *scribble;
Dan Williams36d1c642009-07-14 11:48:22 -07004671 int err;
4672
Dan Williams36d1c642009-07-14 11:48:22 -07004673 allcpus = alloc_percpu(struct raid5_percpu);
4674 if (!allcpus)
4675 return -ENOMEM;
4676 conf->percpu = allcpus;
4677
4678 get_online_cpus();
4679 err = 0;
4680 for_each_present_cpu(cpu) {
Dan Williamsd6f38f32009-07-14 11:50:52 -07004681 if (conf->level == 6) {
4682 spare_page = alloc_page(GFP_KERNEL);
4683 if (!spare_page) {
4684 err = -ENOMEM;
4685 break;
4686 }
4687 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
4688 }
NeilBrown5e5e3e72009-10-16 16:35:30 +11004689 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
Dan Williamsd6f38f32009-07-14 11:50:52 -07004690 if (!scribble) {
Dan Williams36d1c642009-07-14 11:48:22 -07004691 err = -ENOMEM;
4692 break;
4693 }
Dan Williamsd6f38f32009-07-14 11:50:52 -07004694 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
Dan Williams36d1c642009-07-14 11:48:22 -07004695 }
4696#ifdef CONFIG_HOTPLUG_CPU
4697 conf->cpu_notify.notifier_call = raid456_cpu_notify;
4698 conf->cpu_notify.priority = 0;
4699 if (err == 0)
4700 err = register_cpu_notifier(&conf->cpu_notify);
4701#endif
4702 put_online_cpus();
4703
4704 return err;
4705}
4706
NeilBrown91adb562009-03-31 14:39:39 +11004707static raid5_conf_t *setup_conf(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004708{
4709 raid5_conf_t *conf;
NeilBrown5e5e3e72009-10-16 16:35:30 +11004710 int raid_disk, memory, max_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004711 mdk_rdev_t *rdev;
4712 struct disk_info *disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004713
NeilBrown91adb562009-03-31 14:39:39 +11004714 if (mddev->new_level != 5
4715 && mddev->new_level != 4
4716 && mddev->new_level != 6) {
NeilBrown0c55e022010-05-03 14:09:02 +10004717 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
NeilBrown91adb562009-03-31 14:39:39 +11004718 mdname(mddev), mddev->new_level);
4719 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004720 }
NeilBrown91adb562009-03-31 14:39:39 +11004721 if ((mddev->new_level == 5
4722 && !algorithm_valid_raid5(mddev->new_layout)) ||
4723 (mddev->new_level == 6
4724 && !algorithm_valid_raid6(mddev->new_layout))) {
NeilBrown0c55e022010-05-03 14:09:02 +10004725 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
NeilBrown91adb562009-03-31 14:39:39 +11004726 mdname(mddev), mddev->new_layout);
4727 return ERR_PTR(-EIO);
4728 }
4729 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
NeilBrown0c55e022010-05-03 14:09:02 +10004730 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
NeilBrown91adb562009-03-31 14:39:39 +11004731 mdname(mddev), mddev->raid_disks);
4732 return ERR_PTR(-EINVAL);
NeilBrown99c0fb52009-03-31 14:39:38 +11004733 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004734
Andre Noll664e7c42009-06-18 08:45:27 +10004735 if (!mddev->new_chunk_sectors ||
4736 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4737 !is_power_of_2(mddev->new_chunk_sectors)) {
NeilBrown0c55e022010-05-03 14:09:02 +10004738 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
4739 mdname(mddev), mddev->new_chunk_sectors << 9);
NeilBrown91adb562009-03-31 14:39:39 +11004740 return ERR_PTR(-EINVAL);
NeilBrown4bbf3772008-10-13 11:55:12 +11004741 }
4742
NeilBrown91adb562009-03-31 14:39:39 +11004743 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4744 if (conf == NULL)
4745 goto abort;
Dan Williamsf5efd452009-10-16 15:55:38 +11004746 spin_lock_init(&conf->device_lock);
4747 init_waitqueue_head(&conf->wait_for_stripe);
4748 init_waitqueue_head(&conf->wait_for_overlap);
4749 INIT_LIST_HEAD(&conf->handle_list);
4750 INIT_LIST_HEAD(&conf->hold_list);
4751 INIT_LIST_HEAD(&conf->delayed_list);
4752 INIT_LIST_HEAD(&conf->bitmap_list);
4753 INIT_LIST_HEAD(&conf->inactive_list);
4754 atomic_set(&conf->active_stripes, 0);
4755 atomic_set(&conf->preread_active_stripes, 0);
4756 atomic_set(&conf->active_aligned_reads, 0);
4757 conf->bypass_threshold = BYPASS_THRESHOLD;
NeilBrown91adb562009-03-31 14:39:39 +11004758
4759 conf->raid_disks = mddev->raid_disks;
4760 if (mddev->reshape_position == MaxSector)
4761 conf->previous_raid_disks = mddev->raid_disks;
4762 else
4763 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
NeilBrown5e5e3e72009-10-16 16:35:30 +11004764 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
4765 conf->scribble_len = scribble_len(max_disks);
NeilBrown91adb562009-03-31 14:39:39 +11004766
NeilBrown5e5e3e72009-10-16 16:35:30 +11004767 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
NeilBrown91adb562009-03-31 14:39:39 +11004768 GFP_KERNEL);
4769 if (!conf->disks)
4770 goto abort;
4771
4772 conf->mddev = mddev;
4773
4774 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4775 goto abort;
4776
Dan Williams36d1c642009-07-14 11:48:22 -07004777 conf->level = mddev->new_level;
4778 if (raid5_alloc_percpu(conf) != 0)
4779 goto abort;
4780
NeilBrown0c55e022010-05-03 14:09:02 +10004781 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
NeilBrown91adb562009-03-31 14:39:39 +11004782
4783 list_for_each_entry(rdev, &mddev->disks, same_set) {
4784 raid_disk = rdev->raid_disk;
NeilBrown5e5e3e72009-10-16 16:35:30 +11004785 if (raid_disk >= max_disks
NeilBrown91adb562009-03-31 14:39:39 +11004786 || raid_disk < 0)
4787 continue;
4788 disk = conf->disks + raid_disk;
4789
4790 disk->rdev = rdev;
4791
4792 if (test_bit(In_sync, &rdev->flags)) {
4793 char b[BDEVNAME_SIZE];
NeilBrown0c55e022010-05-03 14:09:02 +10004794 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
4795 " disk %d\n",
4796 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
NeilBrown91adb562009-03-31 14:39:39 +11004797 } else
4798 /* Cannot rely on bitmap to complete recovery */
4799 conf->fullsync = 1;
4800 }
4801
Andre Noll09c9e5f2009-06-18 08:45:55 +10004802 conf->chunk_sectors = mddev->new_chunk_sectors;
NeilBrown91adb562009-03-31 14:39:39 +11004803 conf->level = mddev->new_level;
4804 if (conf->level == 6)
4805 conf->max_degraded = 2;
4806 else
4807 conf->max_degraded = 1;
4808 conf->algorithm = mddev->new_layout;
4809 conf->max_nr_stripes = NR_STRIPES;
NeilBrownfef9c612009-03-31 15:16:46 +11004810 conf->reshape_progress = mddev->reshape_position;
NeilBrowne183eae2009-03-31 15:20:22 +11004811 if (conf->reshape_progress != MaxSector) {
Andre Noll09c9e5f2009-06-18 08:45:55 +10004812 conf->prev_chunk_sectors = mddev->chunk_sectors;
NeilBrowne183eae2009-03-31 15:20:22 +11004813 conf->prev_algo = mddev->layout;
4814 }
NeilBrown91adb562009-03-31 14:39:39 +11004815
4816 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
NeilBrown5e5e3e72009-10-16 16:35:30 +11004817 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
NeilBrown91adb562009-03-31 14:39:39 +11004818 if (grow_stripes(conf, conf->max_nr_stripes)) {
4819 printk(KERN_ERR
NeilBrown0c55e022010-05-03 14:09:02 +10004820 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4821 mdname(mddev), memory);
NeilBrown91adb562009-03-31 14:39:39 +11004822 goto abort;
4823 } else
NeilBrown0c55e022010-05-03 14:09:02 +10004824 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
4825 mdname(mddev), memory);
NeilBrown91adb562009-03-31 14:39:39 +11004826
NeilBrown0da3c612009-09-23 18:09:45 +10004827 conf->thread = md_register_thread(raid5d, mddev, NULL);
NeilBrown91adb562009-03-31 14:39:39 +11004828 if (!conf->thread) {
4829 printk(KERN_ERR
NeilBrown0c55e022010-05-03 14:09:02 +10004830 "md/raid:%s: couldn't allocate thread.\n",
NeilBrown91adb562009-03-31 14:39:39 +11004831 mdname(mddev));
4832 goto abort;
4833 }
4834
4835 return conf;
4836
4837 abort:
4838 if (conf) {
Dan Williams95fc17a2009-07-31 12:39:15 +10004839 free_conf(conf);
NeilBrown91adb562009-03-31 14:39:39 +11004840 return ERR_PTR(-EIO);
4841 } else
4842 return ERR_PTR(-ENOMEM);
4843}
4844
NeilBrownc148ffd2009-11-13 17:47:00 +11004845
4846static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
4847{
4848 switch (algo) {
4849 case ALGORITHM_PARITY_0:
4850 if (raid_disk < max_degraded)
4851 return 1;
4852 break;
4853 case ALGORITHM_PARITY_N:
4854 if (raid_disk >= raid_disks - max_degraded)
4855 return 1;
4856 break;
4857 case ALGORITHM_PARITY_0_6:
4858 if (raid_disk == 0 ||
4859 raid_disk == raid_disks - 1)
4860 return 1;
4861 break;
4862 case ALGORITHM_LEFT_ASYMMETRIC_6:
4863 case ALGORITHM_RIGHT_ASYMMETRIC_6:
4864 case ALGORITHM_LEFT_SYMMETRIC_6:
4865 case ALGORITHM_RIGHT_SYMMETRIC_6:
4866 if (raid_disk == raid_disks - 1)
4867 return 1;
4868 }
4869 return 0;
4870}
4871
NeilBrown91adb562009-03-31 14:39:39 +11004872static int run(mddev_t *mddev)
4873{
4874 raid5_conf_t *conf;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10004875 int working_disks = 0, chunk_size;
NeilBrownc148ffd2009-11-13 17:47:00 +11004876 int dirty_parity_disks = 0;
NeilBrown91adb562009-03-31 14:39:39 +11004877 mdk_rdev_t *rdev;
NeilBrownc148ffd2009-11-13 17:47:00 +11004878 sector_t reshape_offset = 0;
NeilBrown91adb562009-03-31 14:39:39 +11004879
Andre Noll8c6ac862009-06-18 08:48:06 +10004880 if (mddev->recovery_cp != MaxSector)
NeilBrown0c55e022010-05-03 14:09:02 +10004881 printk(KERN_NOTICE "md/raid:%s: not clean"
Andre Noll8c6ac862009-06-18 08:48:06 +10004882 " -- starting background reconstruction\n",
4883 mdname(mddev));
NeilBrownf6705572006-03-27 01:18:11 -08004884 if (mddev->reshape_position != MaxSector) {
4885 /* Check that we can continue the reshape.
4886 * Currently only disks can change, it must
4887 * increase, and we must be past the point where
4888 * a stripe over-writes itself
4889 */
4890 sector_t here_new, here_old;
4891 int old_disks;
Andre Noll18b00332009-03-31 15:00:56 +11004892 int max_degraded = (mddev->level == 6 ? 2 : 1);
NeilBrownf6705572006-03-27 01:18:11 -08004893
NeilBrown88ce4932009-03-31 15:24:23 +11004894 if (mddev->new_level != mddev->level) {
NeilBrown0c55e022010-05-03 14:09:02 +10004895 printk(KERN_ERR "md/raid:%s: unsupported reshape "
NeilBrownf4168852007-02-28 20:11:53 -08004896 "required - aborting.\n",
NeilBrownf6705572006-03-27 01:18:11 -08004897 mdname(mddev));
4898 return -EINVAL;
4899 }
NeilBrownf6705572006-03-27 01:18:11 -08004900 old_disks = mddev->raid_disks - mddev->delta_disks;
4901 /* reshape_position must be on a new-stripe boundary, and one
NeilBrownf4168852007-02-28 20:11:53 -08004902 * further up in new geometry must map after here in old
4903 * geometry.
NeilBrownf6705572006-03-27 01:18:11 -08004904 */
4905 here_new = mddev->reshape_position;
Andre Noll664e7c42009-06-18 08:45:27 +10004906 if (sector_div(here_new, mddev->new_chunk_sectors *
NeilBrownf4168852007-02-28 20:11:53 -08004907 (mddev->raid_disks - max_degraded))) {
NeilBrown0c55e022010-05-03 14:09:02 +10004908 printk(KERN_ERR "md/raid:%s: reshape_position not "
4909 "on a stripe boundary\n", mdname(mddev));
NeilBrownf6705572006-03-27 01:18:11 -08004910 return -EINVAL;
4911 }
NeilBrownc148ffd2009-11-13 17:47:00 +11004912 reshape_offset = here_new * mddev->new_chunk_sectors;
NeilBrownf6705572006-03-27 01:18:11 -08004913 /* here_new is the stripe we will write to */
4914 here_old = mddev->reshape_position;
Andre Noll9d8f0362009-06-18 08:45:01 +10004915 sector_div(here_old, mddev->chunk_sectors *
NeilBrownf4168852007-02-28 20:11:53 -08004916 (old_disks-max_degraded));
4917 /* here_old is the first stripe that we might need to read
4918 * from */
NeilBrown67ac6012009-08-13 10:06:24 +10004919 if (mddev->delta_disks == 0) {
4920 /* We cannot be sure it is safe to start an in-place
4921 * reshape. It is only safe if user-space if monitoring
4922 * and taking constant backups.
4923 * mdadm always starts a situation like this in
4924 * readonly mode so it can take control before
4925 * allowing any writes. So just check for that.
4926 */
4927 if ((here_new * mddev->new_chunk_sectors !=
4928 here_old * mddev->chunk_sectors) ||
4929 mddev->ro == 0) {
NeilBrown0c55e022010-05-03 14:09:02 +10004930 printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
4931 " in read-only mode - aborting\n",
4932 mdname(mddev));
NeilBrown67ac6012009-08-13 10:06:24 +10004933 return -EINVAL;
4934 }
4935 } else if (mddev->delta_disks < 0
4936 ? (here_new * mddev->new_chunk_sectors <=
4937 here_old * mddev->chunk_sectors)
4938 : (here_new * mddev->new_chunk_sectors >=
4939 here_old * mddev->chunk_sectors)) {
NeilBrownf6705572006-03-27 01:18:11 -08004940 /* Reading from the same stripe as writing to - bad */
NeilBrown0c55e022010-05-03 14:09:02 +10004941 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
4942 "auto-recovery - aborting.\n",
4943 mdname(mddev));
NeilBrownf6705572006-03-27 01:18:11 -08004944 return -EINVAL;
4945 }
NeilBrown0c55e022010-05-03 14:09:02 +10004946 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
4947 mdname(mddev));
NeilBrownf6705572006-03-27 01:18:11 -08004948 /* OK, we should be able to continue; */
NeilBrownf6705572006-03-27 01:18:11 -08004949 } else {
NeilBrown91adb562009-03-31 14:39:39 +11004950 BUG_ON(mddev->level != mddev->new_level);
4951 BUG_ON(mddev->layout != mddev->new_layout);
Andre Noll664e7c42009-06-18 08:45:27 +10004952 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
NeilBrown91adb562009-03-31 14:39:39 +11004953 BUG_ON(mddev->delta_disks != 0);
NeilBrownf6705572006-03-27 01:18:11 -08004954 }
4955
NeilBrown245f46c2009-03-31 14:39:39 +11004956 if (mddev->private == NULL)
4957 conf = setup_conf(mddev);
4958 else
4959 conf = mddev->private;
4960
NeilBrown91adb562009-03-31 14:39:39 +11004961 if (IS_ERR(conf))
4962 return PTR_ERR(conf);
NeilBrown9ffae0c2006-01-06 00:20:32 -08004963
NeilBrown91adb562009-03-31 14:39:39 +11004964 mddev->thread = conf->thread;
4965 conf->thread = NULL;
4966 mddev->private = conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004967
Linus Torvalds1da177e2005-04-16 15:20:36 -07004968 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07004969 * 0 for a fully functional array, 1 or 2 for a degraded array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004970 */
NeilBrownc148ffd2009-11-13 17:47:00 +11004971 list_for_each_entry(rdev, &mddev->disks, same_set) {
4972 if (rdev->raid_disk < 0)
4973 continue;
4974 if (test_bit(In_sync, &rdev->flags))
NeilBrown91adb562009-03-31 14:39:39 +11004975 working_disks++;
NeilBrownc148ffd2009-11-13 17:47:00 +11004976 /* This disc is not fully in-sync. However if it
4977 * just stored parity (beyond the recovery_offset),
4978 * when we don't need to be concerned about the
4979 * array being dirty.
4980 * When reshape goes 'backwards', we never have
4981 * partially completed devices, so we only need
4982 * to worry about reshape going forwards.
4983 */
4984 /* Hack because v0.91 doesn't store recovery_offset properly. */
4985 if (mddev->major_version == 0 &&
4986 mddev->minor_version > 90)
4987 rdev->recovery_offset = reshape_offset;
4988
NeilBrownc148ffd2009-11-13 17:47:00 +11004989 if (rdev->recovery_offset < reshape_offset) {
4990 /* We need to check old and new layout */
4991 if (!only_parity(rdev->raid_disk,
4992 conf->algorithm,
4993 conf->raid_disks,
4994 conf->max_degraded))
4995 continue;
4996 }
4997 if (!only_parity(rdev->raid_disk,
4998 conf->prev_algo,
4999 conf->previous_raid_disks,
5000 conf->max_degraded))
5001 continue;
5002 dirty_parity_disks++;
5003 }
NeilBrown91adb562009-03-31 14:39:39 +11005004
NeilBrown5e5e3e72009-10-16 16:35:30 +11005005 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
5006 - working_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005007
NeilBrown16a53ec2006-06-26 00:27:38 -07005008 if (mddev->degraded > conf->max_degraded) {
NeilBrown0c55e022010-05-03 14:09:02 +10005009 printk(KERN_ERR "md/raid:%s: not enough operational devices"
Linus Torvalds1da177e2005-04-16 15:20:36 -07005010 " (%d/%d failed)\n",
NeilBrown02c2de82006-10-03 01:15:47 -07005011 mdname(mddev), mddev->degraded, conf->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005012 goto abort;
5013 }
5014
NeilBrown91adb562009-03-31 14:39:39 +11005015 /* device size must be a multiple of chunk size */
Andre Noll9d8f0362009-06-18 08:45:01 +10005016 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
NeilBrown91adb562009-03-31 14:39:39 +11005017 mddev->resync_max_sectors = mddev->dev_sectors;
5018
NeilBrownc148ffd2009-11-13 17:47:00 +11005019 if (mddev->degraded > dirty_parity_disks &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07005020 mddev->recovery_cp != MaxSector) {
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08005021 if (mddev->ok_start_degraded)
5022 printk(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10005023 "md/raid:%s: starting dirty degraded array"
5024 " - data corruption possible.\n",
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08005025 mdname(mddev));
5026 else {
5027 printk(KERN_ERR
NeilBrown0c55e022010-05-03 14:09:02 +10005028 "md/raid:%s: cannot start dirty degraded array.\n",
NeilBrown6ff8d8ec2006-01-06 00:20:15 -08005029 mdname(mddev));
5030 goto abort;
5031 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005032 }
5033
Linus Torvalds1da177e2005-04-16 15:20:36 -07005034 if (mddev->degraded == 0)
NeilBrown0c55e022010-05-03 14:09:02 +10005035 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5036 " devices, algorithm %d\n", mdname(mddev), conf->level,
NeilBrowne183eae2009-03-31 15:20:22 +11005037 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5038 mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005039 else
NeilBrown0c55e022010-05-03 14:09:02 +10005040 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5041 " out of %d devices, algorithm %d\n",
5042 mdname(mddev), conf->level,
5043 mddev->raid_disks - mddev->degraded,
5044 mddev->raid_disks, mddev->new_layout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005045
5046 print_raid5_conf(conf);
5047
NeilBrownfef9c612009-03-31 15:16:46 +11005048 if (conf->reshape_progress != MaxSector) {
NeilBrownfef9c612009-03-31 15:16:46 +11005049 conf->reshape_safe = conf->reshape_progress;
NeilBrownf6705572006-03-27 01:18:11 -08005050 atomic_set(&conf->reshape_stripes, 0);
5051 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5052 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5053 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5054 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5055 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
NeilBrown0da3c612009-09-23 18:09:45 +10005056 "reshape");
NeilBrownf6705572006-03-27 01:18:11 -08005057 }
5058
Linus Torvalds1da177e2005-04-16 15:20:36 -07005059 /* read-ahead size must cover two whole stripes, which is
NeilBrown16a53ec2006-06-26 00:27:38 -07005060 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
Linus Torvalds1da177e2005-04-16 15:20:36 -07005061 */
5062 {
NeilBrown16a53ec2006-06-26 00:27:38 -07005063 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5064 int stripe = data_disks *
Andre Noll9d8f0362009-06-18 08:45:01 +10005065 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005066 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5067 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5068 }
5069
5070 /* Ok, everything is just fine now */
NeilBrowna64c8762010-04-14 17:15:37 +10005071 if (mddev->to_remove == &raid5_attrs_group)
5072 mddev->to_remove = NULL;
5073 else if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
NeilBrown5e55e2f2007-03-26 21:32:14 -08005074 printk(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10005075 "md/raid:%s: failed to create sysfs attributes.\n",
NeilBrown5e55e2f2007-03-26 21:32:14 -08005076 mdname(mddev));
NeilBrown7a5febe2005-05-16 21:53:16 -07005077
NeilBrown91adb562009-03-31 14:39:39 +11005078 mddev->queue->queue_lock = &conf->device_lock;
5079
NeilBrown7a5febe2005-05-16 21:53:16 -07005080 mddev->queue->unplug_fn = raid5_unplug_device;
NeilBrownf022b2f2006-10-03 01:15:56 -07005081 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown041ae522007-03-26 21:32:14 -08005082 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
NeilBrownf022b2f2006-10-03 01:15:56 -07005083
Dan Williams1f403622009-03-31 14:59:03 +11005084 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
NeilBrown7a5febe2005-05-16 21:53:16 -07005085
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08005086 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +10005087 chunk_size = mddev->chunk_sectors << 9;
5088 blk_queue_io_min(mddev->queue, chunk_size);
5089 blk_queue_io_opt(mddev->queue, chunk_size *
5090 (conf->raid_disks - conf->max_degraded));
5091
5092 list_for_each_entry(rdev, &mddev->disks, same_set)
5093 disk_stack_limits(mddev->gendisk, rdev->bdev,
5094 rdev->data_offset << 9);
Raz Ben-Jehuda(caro)23032a02006-12-10 02:20:45 -08005095
Linus Torvalds1da177e2005-04-16 15:20:36 -07005096 return 0;
5097abort:
NeilBrowne0cf8f02009-03-31 14:39:39 +11005098 md_unregister_thread(mddev->thread);
NeilBrown91adb562009-03-31 14:39:39 +11005099 mddev->thread = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005100 if (conf) {
5101 print_raid5_conf(conf);
Dan Williams95fc17a2009-07-31 12:39:15 +10005102 free_conf(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005103 }
5104 mddev->private = NULL;
NeilBrown0c55e022010-05-03 14:09:02 +10005105 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005106 return -EIO;
5107}
5108
NeilBrown3f294f42005-11-08 21:39:25 -08005109static int stop(mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005110{
H Hartley Sweeten7b928132010-03-08 16:02:40 +11005111 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005112
5113 md_unregister_thread(mddev->thread);
5114 mddev->thread = NULL;
NeilBrown041ae522007-03-26 21:32:14 -08005115 mddev->queue->backing_dev_info.congested_fn = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005116 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
Dan Williams95fc17a2009-07-31 12:39:15 +10005117 free_conf(conf);
NeilBrowna64c8762010-04-14 17:15:37 +10005118 mddev->private = NULL;
5119 mddev->to_remove = &raid5_attrs_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005120 return 0;
5121}
5122
Dan Williams45b42332007-07-09 11:56:43 -07005123#ifdef DEBUG
NeilBrownd710e132008-10-13 11:55:12 +11005124static void print_sh(struct seq_file *seq, struct stripe_head *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005125{
5126 int i;
5127
NeilBrown16a53ec2006-06-26 00:27:38 -07005128 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
5129 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
5130 seq_printf(seq, "sh %llu, count %d.\n",
5131 (unsigned long long)sh->sector, atomic_read(&sh->count));
5132 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
NeilBrown7ecaa1e2006-03-27 01:18:08 -08005133 for (i = 0; i < sh->disks; i++) {
NeilBrown16a53ec2006-06-26 00:27:38 -07005134 seq_printf(seq, "(cache%d: %p %ld) ",
5135 i, sh->dev[i].page, sh->dev[i].flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005136 }
NeilBrown16a53ec2006-06-26 00:27:38 -07005137 seq_printf(seq, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005138}
5139
NeilBrownd710e132008-10-13 11:55:12 +11005140static void printall(struct seq_file *seq, raid5_conf_t *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005141{
5142 struct stripe_head *sh;
NeilBrownfccddba2006-01-06 00:20:33 -08005143 struct hlist_node *hn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005144 int i;
5145
5146 spin_lock_irq(&conf->device_lock);
5147 for (i = 0; i < NR_HASH; i++) {
NeilBrownfccddba2006-01-06 00:20:33 -08005148 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005149 if (sh->raid_conf != conf)
5150 continue;
NeilBrown16a53ec2006-06-26 00:27:38 -07005151 print_sh(seq, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005152 }
5153 }
5154 spin_unlock_irq(&conf->device_lock);
5155}
5156#endif
5157
NeilBrownd710e132008-10-13 11:55:12 +11005158static void status(struct seq_file *seq, mddev_t *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005159{
H Hartley Sweeten7b928132010-03-08 16:02:40 +11005160 raid5_conf_t *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005161 int i;
5162
Andre Noll9d8f0362009-06-18 08:45:01 +10005163 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5164 mddev->chunk_sectors / 2, mddev->layout);
NeilBrown02c2de82006-10-03 01:15:47 -07005165 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005166 for (i = 0; i < conf->raid_disks; i++)
5167 seq_printf (seq, "%s",
5168 conf->disks[i].rdev &&
NeilBrownb2d444d2005-11-08 21:39:31 -08005169 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005170 seq_printf (seq, "]");
Dan Williams45b42332007-07-09 11:56:43 -07005171#ifdef DEBUG
NeilBrown16a53ec2006-06-26 00:27:38 -07005172 seq_printf (seq, "\n");
5173 printall(seq, conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005174#endif
5175}
5176
5177static void print_raid5_conf (raid5_conf_t *conf)
5178{
5179 int i;
5180 struct disk_info *tmp;
5181
NeilBrown0c55e022010-05-03 14:09:02 +10005182 printk(KERN_DEBUG "RAID conf printout:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005183 if (!conf) {
5184 printk("(conf==NULL)\n");
5185 return;
5186 }
NeilBrown0c55e022010-05-03 14:09:02 +10005187 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
5188 conf->raid_disks,
5189 conf->raid_disks - conf->mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005190
5191 for (i = 0; i < conf->raid_disks; i++) {
5192 char b[BDEVNAME_SIZE];
5193 tmp = conf->disks + i;
5194 if (tmp->rdev)
NeilBrown0c55e022010-05-03 14:09:02 +10005195 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
5196 i, !test_bit(Faulty, &tmp->rdev->flags),
5197 bdevname(tmp->rdev->bdev, b));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005198 }
5199}
5200
5201static int raid5_spare_active(mddev_t *mddev)
5202{
5203 int i;
5204 raid5_conf_t *conf = mddev->private;
5205 struct disk_info *tmp;
5206
5207 for (i = 0; i < conf->raid_disks; i++) {
5208 tmp = conf->disks + i;
5209 if (tmp->rdev
NeilBrownb2d444d2005-11-08 21:39:31 -08005210 && !test_bit(Faulty, &tmp->rdev->flags)
NeilBrownc04be0a2006-10-03 01:15:53 -07005211 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
5212 unsigned long flags;
5213 spin_lock_irqsave(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005214 mddev->degraded--;
NeilBrownc04be0a2006-10-03 01:15:53 -07005215 spin_unlock_irqrestore(&conf->device_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005216 }
5217 }
5218 print_raid5_conf(conf);
5219 return 0;
5220}
5221
5222static int raid5_remove_disk(mddev_t *mddev, int number)
5223{
5224 raid5_conf_t *conf = mddev->private;
5225 int err = 0;
5226 mdk_rdev_t *rdev;
5227 struct disk_info *p = conf->disks + number;
5228
5229 print_raid5_conf(conf);
5230 rdev = p->rdev;
5231 if (rdev) {
NeilBrownec32a2b2009-03-31 15:17:38 +11005232 if (number >= conf->raid_disks &&
5233 conf->reshape_progress == MaxSector)
5234 clear_bit(In_sync, &rdev->flags);
5235
NeilBrownb2d444d2005-11-08 21:39:31 -08005236 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07005237 atomic_read(&rdev->nr_pending)) {
5238 err = -EBUSY;
5239 goto abort;
5240 }
NeilBrowndfc70642008-05-23 13:04:39 -07005241 /* Only remove non-faulty devices if recovery
5242 * isn't possible.
5243 */
5244 if (!test_bit(Faulty, &rdev->flags) &&
NeilBrownec32a2b2009-03-31 15:17:38 +11005245 mddev->degraded <= conf->max_degraded &&
5246 number < conf->raid_disks) {
NeilBrowndfc70642008-05-23 13:04:39 -07005247 err = -EBUSY;
5248 goto abort;
5249 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005250 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -07005251 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005252 if (atomic_read(&rdev->nr_pending)) {
5253 /* lost the race, try later */
5254 err = -EBUSY;
5255 p->rdev = rdev;
5256 }
5257 }
5258abort:
5259
5260 print_raid5_conf(conf);
5261 return err;
5262}
5263
5264static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
5265{
5266 raid5_conf_t *conf = mddev->private;
Neil Brown199050e2008-06-28 08:31:33 +10005267 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005268 int disk;
5269 struct disk_info *p;
Neil Brown6c2fce22008-06-28 08:31:31 +10005270 int first = 0;
5271 int last = conf->raid_disks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005272
NeilBrown16a53ec2006-06-26 00:27:38 -07005273 if (mddev->degraded > conf->max_degraded)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005274 /* no point adding a device */
Neil Brown199050e2008-06-28 08:31:33 +10005275 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005276
Neil Brown6c2fce22008-06-28 08:31:31 +10005277 if (rdev->raid_disk >= 0)
5278 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005279
5280 /*
NeilBrown16a53ec2006-06-26 00:27:38 -07005281 * find the disk ... but prefer rdev->saved_raid_disk
5282 * if possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005283 */
NeilBrown16a53ec2006-06-26 00:27:38 -07005284 if (rdev->saved_raid_disk >= 0 &&
Neil Brown6c2fce22008-06-28 08:31:31 +10005285 rdev->saved_raid_disk >= first &&
NeilBrown16a53ec2006-06-26 00:27:38 -07005286 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5287 disk = rdev->saved_raid_disk;
5288 else
Neil Brown6c2fce22008-06-28 08:31:31 +10005289 disk = first;
5290 for ( ; disk <= last ; disk++)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005291 if ((p=conf->disks + disk)->rdev == NULL) {
NeilBrownb2d444d2005-11-08 21:39:31 -08005292 clear_bit(In_sync, &rdev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005293 rdev->raid_disk = disk;
Neil Brown199050e2008-06-28 08:31:33 +10005294 err = 0;
NeilBrown72626682005-09-09 16:23:54 -07005295 if (rdev->saved_raid_disk != disk)
5296 conf->fullsync = 1;
Suzanne Woodd6065f72005-11-08 21:39:27 -08005297 rcu_assign_pointer(p->rdev, rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005298 break;
5299 }
5300 print_raid5_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +10005301 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005302}
5303
5304static int raid5_resize(mddev_t *mddev, sector_t sectors)
5305{
5306 /* no resync is happening, and there is enough space
5307 * on all devices, so we can resize.
5308 * We need to make sure resync covers any new space.
5309 * If the array is shrinking we should possibly wait until
5310 * any io in the removed space completes, but it hardly seems
5311 * worth it.
5312 */
Andre Noll9d8f0362009-06-18 08:45:01 +10005313 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
Dan Williams1f403622009-03-31 14:59:03 +11005314 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
5315 mddev->raid_disks));
Dan Williamsb522adc2009-03-31 15:00:31 +11005316 if (mddev->array_sectors >
5317 raid5_size(mddev, sectors, mddev->raid_disks))
5318 return -EINVAL;
Andre Nollf233ea52008-07-21 17:05:22 +10005319 set_capacity(mddev->gendisk, mddev->array_sectors);
NeilBrown449aad32009-08-03 10:59:58 +10005320 revalidate_disk(mddev->gendisk);
Andre Noll58c0fed2009-03-31 14:33:13 +11005321 if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
5322 mddev->recovery_cp = mddev->dev_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005323 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5324 }
Andre Noll58c0fed2009-03-31 14:33:13 +11005325 mddev->dev_sectors = sectors;
NeilBrown4b5c7ae2005-07-27 11:43:28 -07005326 mddev->resync_max_sectors = sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005327 return 0;
5328}
5329
NeilBrown01ee22b2009-06-18 08:47:20 +10005330static int check_stripe_cache(mddev_t *mddev)
5331{
5332 /* Can only proceed if there are plenty of stripe_heads.
5333 * We need a minimum of one full stripe,, and for sensible progress
5334 * it is best to have about 4 times that.
5335 * If we require 4 times, then the default 256 4K stripe_heads will
5336 * allow for chunk sizes up to 256K, which is probably OK.
5337 * If the chunk size is greater, user-space should request more
5338 * stripe_heads first.
5339 */
5340 raid5_conf_t *conf = mddev->private;
5341 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5342 > conf->max_nr_stripes ||
5343 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5344 > conf->max_nr_stripes) {
NeilBrown0c55e022010-05-03 14:09:02 +10005345 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5346 mdname(mddev),
NeilBrown01ee22b2009-06-18 08:47:20 +10005347 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5348 / STRIPE_SIZE)*4);
5349 return 0;
5350 }
5351 return 1;
5352}
5353
NeilBrown50ac1682009-06-18 08:47:55 +10005354static int check_reshape(mddev_t *mddev)
NeilBrown29269552006-03-27 01:18:10 -08005355{
NeilBrown070ec552009-06-16 16:54:21 +10005356 raid5_conf_t *conf = mddev->private;
NeilBrown29269552006-03-27 01:18:10 -08005357
NeilBrown88ce4932009-03-31 15:24:23 +11005358 if (mddev->delta_disks == 0 &&
5359 mddev->new_layout == mddev->layout &&
Andre Noll664e7c42009-06-18 08:45:27 +10005360 mddev->new_chunk_sectors == mddev->chunk_sectors)
NeilBrown50ac1682009-06-18 08:47:55 +10005361 return 0; /* nothing to do */
NeilBrowndba034e2008-08-05 15:54:13 +10005362 if (mddev->bitmap)
5363 /* Cannot grow a bitmap yet */
5364 return -EBUSY;
NeilBrownec32a2b2009-03-31 15:17:38 +11005365 if (mddev->degraded > conf->max_degraded)
5366 return -EINVAL;
5367 if (mddev->delta_disks < 0) {
5368 /* We might be able to shrink, but the devices must
5369 * be made bigger first.
5370 * For raid6, 4 is the minimum size.
5371 * Otherwise 2 is the minimum
5372 */
5373 int min = 2;
5374 if (mddev->level == 6)
5375 min = 4;
5376 if (mddev->raid_disks + mddev->delta_disks < min)
5377 return -EINVAL;
5378 }
NeilBrown29269552006-03-27 01:18:10 -08005379
NeilBrown01ee22b2009-06-18 08:47:20 +10005380 if (!check_stripe_cache(mddev))
NeilBrown29269552006-03-27 01:18:10 -08005381 return -ENOSPC;
NeilBrown29269552006-03-27 01:18:10 -08005382
NeilBrownec32a2b2009-03-31 15:17:38 +11005383 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
NeilBrown63c70c42006-03-27 01:18:13 -08005384}
5385
5386static int raid5_start_reshape(mddev_t *mddev)
5387{
NeilBrown070ec552009-06-16 16:54:21 +10005388 raid5_conf_t *conf = mddev->private;
NeilBrown63c70c42006-03-27 01:18:13 -08005389 mdk_rdev_t *rdev;
NeilBrown63c70c42006-03-27 01:18:13 -08005390 int spares = 0;
5391 int added_devices = 0;
NeilBrownc04be0a2006-10-03 01:15:53 -07005392 unsigned long flags;
NeilBrown63c70c42006-03-27 01:18:13 -08005393
NeilBrownf4168852007-02-28 20:11:53 -08005394 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
NeilBrown63c70c42006-03-27 01:18:13 -08005395 return -EBUSY;
5396
NeilBrown01ee22b2009-06-18 08:47:20 +10005397 if (!check_stripe_cache(mddev))
5398 return -ENOSPC;
5399
Cheng Renquan159ec1f2009-01-09 08:31:08 +11005400 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08005401 if (rdev->raid_disk < 0 &&
5402 !test_bit(Faulty, &rdev->flags))
5403 spares++;
NeilBrown63c70c42006-03-27 01:18:13 -08005404
NeilBrownf4168852007-02-28 20:11:53 -08005405 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
NeilBrown29269552006-03-27 01:18:10 -08005406 /* Not enough devices even to make a degraded array
5407 * of that size
5408 */
5409 return -EINVAL;
5410
NeilBrownec32a2b2009-03-31 15:17:38 +11005411 /* Refuse to reduce size of the array. Any reductions in
5412 * array size must be through explicit setting of array_size
5413 * attribute.
5414 */
5415 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5416 < mddev->array_sectors) {
NeilBrown0c55e022010-05-03 14:09:02 +10005417 printk(KERN_ERR "md/raid:%s: array size must be reduced "
NeilBrownec32a2b2009-03-31 15:17:38 +11005418 "before number of disks\n", mdname(mddev));
5419 return -EINVAL;
5420 }
5421
NeilBrownf6705572006-03-27 01:18:11 -08005422 atomic_set(&conf->reshape_stripes, 0);
NeilBrown29269552006-03-27 01:18:10 -08005423 spin_lock_irq(&conf->device_lock);
5424 conf->previous_raid_disks = conf->raid_disks;
NeilBrown63c70c42006-03-27 01:18:13 -08005425 conf->raid_disks += mddev->delta_disks;
Andre Noll09c9e5f2009-06-18 08:45:55 +10005426 conf->prev_chunk_sectors = conf->chunk_sectors;
5427 conf->chunk_sectors = mddev->new_chunk_sectors;
NeilBrown88ce4932009-03-31 15:24:23 +11005428 conf->prev_algo = conf->algorithm;
5429 conf->algorithm = mddev->new_layout;
NeilBrownfef9c612009-03-31 15:16:46 +11005430 if (mddev->delta_disks < 0)
5431 conf->reshape_progress = raid5_size(mddev, 0, 0);
5432 else
5433 conf->reshape_progress = 0;
5434 conf->reshape_safe = conf->reshape_progress;
NeilBrown86b42c72009-03-31 15:19:03 +11005435 conf->generation++;
NeilBrown29269552006-03-27 01:18:10 -08005436 spin_unlock_irq(&conf->device_lock);
5437
5438 /* Add some new drives, as many as will fit.
5439 * We know there are enough to make the newly sized array work.
5440 */
Cheng Renquan159ec1f2009-01-09 08:31:08 +11005441 list_for_each_entry(rdev, &mddev->disks, same_set)
NeilBrown29269552006-03-27 01:18:10 -08005442 if (rdev->raid_disk < 0 &&
5443 !test_bit(Faulty, &rdev->flags)) {
Neil Brown199050e2008-06-28 08:31:33 +10005444 if (raid5_add_disk(mddev, rdev) == 0) {
NeilBrown29269552006-03-27 01:18:10 -08005445 char nm[20];
NeilBrown9eb07c22010-02-09 12:31:47 +11005446 if (rdev->raid_disk >= conf->previous_raid_disks) {
NeilBrown7ef90142009-11-13 17:40:51 +11005447 set_bit(In_sync, &rdev->flags);
NeilBrown9eb07c22010-02-09 12:31:47 +11005448 added_devices++;
5449 } else
NeilBrown7ef90142009-11-13 17:40:51 +11005450 rdev->recovery_offset = 0;
NeilBrown29269552006-03-27 01:18:10 -08005451 sprintf(nm, "rd%d", rdev->raid_disk);
NeilBrown5e55e2f2007-03-26 21:32:14 -08005452 if (sysfs_create_link(&mddev->kobj,
5453 &rdev->kobj, nm))
5454 printk(KERN_WARNING
NeilBrown0c55e022010-05-03 14:09:02 +10005455 "md/raid:%s: failed to create "
5456 " link %s\n",
5457 mdname(mddev), nm);
NeilBrown29269552006-03-27 01:18:10 -08005458 } else
5459 break;
5460 }
5461
NeilBrown9eb07c22010-02-09 12:31:47 +11005462 /* When a reshape changes the number of devices, ->degraded
5463 * is measured against the large of the pre and post number of
5464 * devices.*/
NeilBrownec32a2b2009-03-31 15:17:38 +11005465 if (mddev->delta_disks > 0) {
5466 spin_lock_irqsave(&conf->device_lock, flags);
NeilBrown9eb07c22010-02-09 12:31:47 +11005467 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
NeilBrownec32a2b2009-03-31 15:17:38 +11005468 - added_devices;
5469 spin_unlock_irqrestore(&conf->device_lock, flags);
5470 }
NeilBrown63c70c42006-03-27 01:18:13 -08005471 mddev->raid_disks = conf->raid_disks;
NeilBrowne5164022009-08-03 10:59:57 +10005472 mddev->reshape_position = conf->reshape_progress;
NeilBrown850b2b42006-10-03 01:15:46 -07005473 set_bit(MD_CHANGE_DEVS, &mddev->flags);
NeilBrownf6705572006-03-27 01:18:11 -08005474
NeilBrown29269552006-03-27 01:18:10 -08005475 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5476 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5477 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5478 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5479 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
NeilBrown0da3c612009-09-23 18:09:45 +10005480 "reshape");
NeilBrown29269552006-03-27 01:18:10 -08005481 if (!mddev->sync_thread) {
5482 mddev->recovery = 0;
5483 spin_lock_irq(&conf->device_lock);
5484 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11005485 conf->reshape_progress = MaxSector;
NeilBrown29269552006-03-27 01:18:10 -08005486 spin_unlock_irq(&conf->device_lock);
5487 return -EAGAIN;
5488 }
NeilBrownc8f517c2009-03-31 15:28:40 +11005489 conf->reshape_checkpoint = jiffies;
NeilBrown29269552006-03-27 01:18:10 -08005490 md_wakeup_thread(mddev->sync_thread);
5491 md_new_event(mddev);
5492 return 0;
5493}
NeilBrown29269552006-03-27 01:18:10 -08005494
NeilBrownec32a2b2009-03-31 15:17:38 +11005495/* This is called from the reshape thread and should make any
5496 * changes needed in 'conf'
5497 */
NeilBrown29269552006-03-27 01:18:10 -08005498static void end_reshape(raid5_conf_t *conf)
5499{
NeilBrown29269552006-03-27 01:18:10 -08005500
NeilBrownf6705572006-03-27 01:18:11 -08005501 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
Dan Williams80c3a6c2009-03-17 18:10:40 -07005502
NeilBrownf6705572006-03-27 01:18:11 -08005503 spin_lock_irq(&conf->device_lock);
NeilBrowncea9c222009-03-31 15:15:05 +11005504 conf->previous_raid_disks = conf->raid_disks;
NeilBrownfef9c612009-03-31 15:16:46 +11005505 conf->reshape_progress = MaxSector;
NeilBrownf6705572006-03-27 01:18:11 -08005506 spin_unlock_irq(&conf->device_lock);
NeilBrownb0f9ec02009-03-31 15:27:18 +11005507 wake_up(&conf->wait_for_overlap);
NeilBrown16a53ec2006-06-26 00:27:38 -07005508
5509 /* read-ahead size must cover two whole stripes, which is
5510 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5511 */
5512 {
NeilBrowncea9c222009-03-31 15:15:05 +11005513 int data_disks = conf->raid_disks - conf->max_degraded;
Andre Noll09c9e5f2009-06-18 08:45:55 +10005514 int stripe = data_disks * ((conf->chunk_sectors << 9)
NeilBrowncea9c222009-03-31 15:15:05 +11005515 / PAGE_SIZE);
NeilBrown16a53ec2006-06-26 00:27:38 -07005516 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5517 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5518 }
NeilBrown29269552006-03-27 01:18:10 -08005519 }
NeilBrown29269552006-03-27 01:18:10 -08005520}
5521
NeilBrownec32a2b2009-03-31 15:17:38 +11005522/* This is called from the raid5d thread with mddev_lock held.
5523 * It makes config changes to the device.
5524 */
NeilBrowncea9c222009-03-31 15:15:05 +11005525static void raid5_finish_reshape(mddev_t *mddev)
5526{
NeilBrown070ec552009-06-16 16:54:21 +10005527 raid5_conf_t *conf = mddev->private;
NeilBrowncea9c222009-03-31 15:15:05 +11005528
5529 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5530
NeilBrownec32a2b2009-03-31 15:17:38 +11005531 if (mddev->delta_disks > 0) {
5532 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5533 set_capacity(mddev->gendisk, mddev->array_sectors);
NeilBrown449aad32009-08-03 10:59:58 +10005534 revalidate_disk(mddev->gendisk);
NeilBrownec32a2b2009-03-31 15:17:38 +11005535 } else {
5536 int d;
NeilBrownec32a2b2009-03-31 15:17:38 +11005537 mddev->degraded = conf->raid_disks;
5538 for (d = 0; d < conf->raid_disks ; d++)
5539 if (conf->disks[d].rdev &&
5540 test_bit(In_sync,
5541 &conf->disks[d].rdev->flags))
5542 mddev->degraded--;
5543 for (d = conf->raid_disks ;
5544 d < conf->raid_disks - mddev->delta_disks;
NeilBrown1a67dde2009-08-13 10:41:49 +10005545 d++) {
5546 mdk_rdev_t *rdev = conf->disks[d].rdev;
5547 if (rdev && raid5_remove_disk(mddev, d) == 0) {
5548 char nm[20];
5549 sprintf(nm, "rd%d", rdev->raid_disk);
5550 sysfs_remove_link(&mddev->kobj, nm);
5551 rdev->raid_disk = -1;
5552 }
5553 }
NeilBrowncea9c222009-03-31 15:15:05 +11005554 }
NeilBrown88ce4932009-03-31 15:24:23 +11005555 mddev->layout = conf->algorithm;
Andre Noll09c9e5f2009-06-18 08:45:55 +10005556 mddev->chunk_sectors = conf->chunk_sectors;
NeilBrownec32a2b2009-03-31 15:17:38 +11005557 mddev->reshape_position = MaxSector;
5558 mddev->delta_disks = 0;
NeilBrowncea9c222009-03-31 15:15:05 +11005559 }
5560}
5561
NeilBrown72626682005-09-09 16:23:54 -07005562static void raid5_quiesce(mddev_t *mddev, int state)
5563{
NeilBrown070ec552009-06-16 16:54:21 +10005564 raid5_conf_t *conf = mddev->private;
NeilBrown72626682005-09-09 16:23:54 -07005565
5566 switch(state) {
NeilBrowne464eaf2006-03-27 01:18:14 -08005567 case 2: /* resume for a suspend */
5568 wake_up(&conf->wait_for_overlap);
5569 break;
5570
NeilBrown72626682005-09-09 16:23:54 -07005571 case 1: /* stop all writes */
5572 spin_lock_irq(&conf->device_lock);
NeilBrown64bd6602009-08-03 10:59:58 +10005573 /* '2' tells resync/reshape to pause so that all
5574 * active stripes can drain
5575 */
5576 conf->quiesce = 2;
NeilBrown72626682005-09-09 16:23:54 -07005577 wait_event_lock_irq(conf->wait_for_stripe,
Raz Ben-Jehuda(caro)46031f92006-12-10 02:20:47 -08005578 atomic_read(&conf->active_stripes) == 0 &&
5579 atomic_read(&conf->active_aligned_reads) == 0,
NeilBrown72626682005-09-09 16:23:54 -07005580 conf->device_lock, /* nothing */);
NeilBrown64bd6602009-08-03 10:59:58 +10005581 conf->quiesce = 1;
NeilBrown72626682005-09-09 16:23:54 -07005582 spin_unlock_irq(&conf->device_lock);
NeilBrown64bd6602009-08-03 10:59:58 +10005583 /* allow reshape to continue */
5584 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07005585 break;
5586
5587 case 0: /* re-enable writes */
5588 spin_lock_irq(&conf->device_lock);
5589 conf->quiesce = 0;
5590 wake_up(&conf->wait_for_stripe);
NeilBrowne464eaf2006-03-27 01:18:14 -08005591 wake_up(&conf->wait_for_overlap);
NeilBrown72626682005-09-09 16:23:54 -07005592 spin_unlock_irq(&conf->device_lock);
5593 break;
5594 }
NeilBrown72626682005-09-09 16:23:54 -07005595}
NeilBrownb15c2e52006-01-06 00:20:16 -08005596
NeilBrownd562b0c2009-03-31 14:39:39 +11005597
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005598static void *raid45_takeover_raid0(mddev_t *mddev, int level)
Trela Maciej54071b32010-03-08 16:02:42 +11005599{
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005600 struct raid0_private_data *raid0_priv = mddev->private;
Trela Maciej54071b32010-03-08 16:02:42 +11005601
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005602 /* for raid0 takeover only one zone is supported */
5603 if (raid0_priv->nr_strip_zones > 1) {
NeilBrown0c55e022010-05-03 14:09:02 +10005604 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5605 mdname(mddev));
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005606 return ERR_PTR(-EINVAL);
5607 }
5608
5609 mddev->new_level = level;
Trela Maciej54071b32010-03-08 16:02:42 +11005610 mddev->new_layout = ALGORITHM_PARITY_N;
5611 mddev->new_chunk_sectors = mddev->chunk_sectors;
5612 mddev->raid_disks += 1;
5613 mddev->delta_disks = 1;
5614 /* make sure it will be not marked as dirty */
5615 mddev->recovery_cp = MaxSector;
5616
5617 return setup_conf(mddev);
5618}
5619
5620
NeilBrownd562b0c2009-03-31 14:39:39 +11005621static void *raid5_takeover_raid1(mddev_t *mddev)
5622{
5623 int chunksect;
5624
5625 if (mddev->raid_disks != 2 ||
5626 mddev->degraded > 1)
5627 return ERR_PTR(-EINVAL);
5628
5629 /* Should check if there are write-behind devices? */
5630
5631 chunksect = 64*2; /* 64K by default */
5632
5633 /* The array must be an exact multiple of chunksize */
5634 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5635 chunksect >>= 1;
5636
5637 if ((chunksect<<9) < STRIPE_SIZE)
5638 /* array size does not allow a suitable chunk size */
5639 return ERR_PTR(-EINVAL);
5640
5641 mddev->new_level = 5;
5642 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
Andre Noll664e7c42009-06-18 08:45:27 +10005643 mddev->new_chunk_sectors = chunksect;
NeilBrownd562b0c2009-03-31 14:39:39 +11005644
5645 return setup_conf(mddev);
5646}
5647
NeilBrownfc9739c2009-03-31 14:57:20 +11005648static void *raid5_takeover_raid6(mddev_t *mddev)
5649{
5650 int new_layout;
5651
5652 switch (mddev->layout) {
5653 case ALGORITHM_LEFT_ASYMMETRIC_6:
5654 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5655 break;
5656 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5657 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5658 break;
5659 case ALGORITHM_LEFT_SYMMETRIC_6:
5660 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5661 break;
5662 case ALGORITHM_RIGHT_SYMMETRIC_6:
5663 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5664 break;
5665 case ALGORITHM_PARITY_0_6:
5666 new_layout = ALGORITHM_PARITY_0;
5667 break;
5668 case ALGORITHM_PARITY_N:
5669 new_layout = ALGORITHM_PARITY_N;
5670 break;
5671 default:
5672 return ERR_PTR(-EINVAL);
5673 }
5674 mddev->new_level = 5;
5675 mddev->new_layout = new_layout;
5676 mddev->delta_disks = -1;
5677 mddev->raid_disks -= 1;
5678 return setup_conf(mddev);
5679}
5680
NeilBrownd562b0c2009-03-31 14:39:39 +11005681
NeilBrown50ac1682009-06-18 08:47:55 +10005682static int raid5_check_reshape(mddev_t *mddev)
NeilBrownb3546032009-03-31 14:56:41 +11005683{
NeilBrown88ce4932009-03-31 15:24:23 +11005684 /* For a 2-drive array, the layout and chunk size can be changed
5685 * immediately as not restriping is needed.
5686 * For larger arrays we record the new value - after validation
5687 * to be used by a reshape pass.
NeilBrownb3546032009-03-31 14:56:41 +11005688 */
NeilBrown070ec552009-06-16 16:54:21 +10005689 raid5_conf_t *conf = mddev->private;
NeilBrown597a7112009-06-18 08:47:42 +10005690 int new_chunk = mddev->new_chunk_sectors;
NeilBrownb3546032009-03-31 14:56:41 +11005691
NeilBrown597a7112009-06-18 08:47:42 +10005692 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
NeilBrownb3546032009-03-31 14:56:41 +11005693 return -EINVAL;
5694 if (new_chunk > 0) {
Andre Noll0ba459d2009-06-18 08:46:10 +10005695 if (!is_power_of_2(new_chunk))
NeilBrownb3546032009-03-31 14:56:41 +11005696 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005697 if (new_chunk < (PAGE_SIZE>>9))
NeilBrownb3546032009-03-31 14:56:41 +11005698 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005699 if (mddev->array_sectors & (new_chunk-1))
NeilBrownb3546032009-03-31 14:56:41 +11005700 /* not factor of array size */
5701 return -EINVAL;
5702 }
5703
5704 /* They look valid */
5705
NeilBrown88ce4932009-03-31 15:24:23 +11005706 if (mddev->raid_disks == 2) {
NeilBrown597a7112009-06-18 08:47:42 +10005707 /* can make the change immediately */
5708 if (mddev->new_layout >= 0) {
5709 conf->algorithm = mddev->new_layout;
5710 mddev->layout = mddev->new_layout;
NeilBrown88ce4932009-03-31 15:24:23 +11005711 }
5712 if (new_chunk > 0) {
NeilBrown597a7112009-06-18 08:47:42 +10005713 conf->chunk_sectors = new_chunk ;
5714 mddev->chunk_sectors = new_chunk;
NeilBrown88ce4932009-03-31 15:24:23 +11005715 }
5716 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5717 md_wakeup_thread(mddev->thread);
NeilBrownb3546032009-03-31 14:56:41 +11005718 }
NeilBrown50ac1682009-06-18 08:47:55 +10005719 return check_reshape(mddev);
NeilBrown88ce4932009-03-31 15:24:23 +11005720}
5721
NeilBrown50ac1682009-06-18 08:47:55 +10005722static int raid6_check_reshape(mddev_t *mddev)
NeilBrown88ce4932009-03-31 15:24:23 +11005723{
NeilBrown597a7112009-06-18 08:47:42 +10005724 int new_chunk = mddev->new_chunk_sectors;
NeilBrown50ac1682009-06-18 08:47:55 +10005725
NeilBrown597a7112009-06-18 08:47:42 +10005726 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
NeilBrown88ce4932009-03-31 15:24:23 +11005727 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005728 if (new_chunk > 0) {
Andre Noll0ba459d2009-06-18 08:46:10 +10005729 if (!is_power_of_2(new_chunk))
NeilBrown88ce4932009-03-31 15:24:23 +11005730 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005731 if (new_chunk < (PAGE_SIZE >> 9))
NeilBrown88ce4932009-03-31 15:24:23 +11005732 return -EINVAL;
NeilBrown597a7112009-06-18 08:47:42 +10005733 if (mddev->array_sectors & (new_chunk-1))
NeilBrown88ce4932009-03-31 15:24:23 +11005734 /* not factor of array size */
5735 return -EINVAL;
NeilBrownb3546032009-03-31 14:56:41 +11005736 }
NeilBrown88ce4932009-03-31 15:24:23 +11005737
5738 /* They look valid */
NeilBrown50ac1682009-06-18 08:47:55 +10005739 return check_reshape(mddev);
NeilBrownb3546032009-03-31 14:56:41 +11005740}
5741
NeilBrownd562b0c2009-03-31 14:39:39 +11005742static void *raid5_takeover(mddev_t *mddev)
5743{
5744 /* raid5 can take over:
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005745 * raid0 - if there is only one strip zone - make it a raid4 layout
NeilBrownd562b0c2009-03-31 14:39:39 +11005746 * raid1 - if there are two drives. We need to know the chunk size
5747 * raid4 - trivial - just use a raid4 layout.
5748 * raid6 - Providing it is a *_6 layout
NeilBrownd562b0c2009-03-31 14:39:39 +11005749 */
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005750 if (mddev->level == 0)
5751 return raid45_takeover_raid0(mddev, 5);
NeilBrownd562b0c2009-03-31 14:39:39 +11005752 if (mddev->level == 1)
5753 return raid5_takeover_raid1(mddev);
NeilBrowne9d47582009-03-31 14:57:09 +11005754 if (mddev->level == 4) {
5755 mddev->new_layout = ALGORITHM_PARITY_N;
5756 mddev->new_level = 5;
5757 return setup_conf(mddev);
5758 }
NeilBrownfc9739c2009-03-31 14:57:20 +11005759 if (mddev->level == 6)
5760 return raid5_takeover_raid6(mddev);
NeilBrownd562b0c2009-03-31 14:39:39 +11005761
5762 return ERR_PTR(-EINVAL);
5763}
5764
NeilBrowna78d38a2010-03-22 16:53:49 +11005765static void *raid4_takeover(mddev_t *mddev)
5766{
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005767 /* raid4 can take over:
5768 * raid0 - if there is only one strip zone
5769 * raid5 - if layout is right
NeilBrowna78d38a2010-03-22 16:53:49 +11005770 */
Dan Williamsf1b29bc2010-05-01 18:09:05 -07005771 if (mddev->level == 0)
5772 return raid45_takeover_raid0(mddev, 4);
NeilBrowna78d38a2010-03-22 16:53:49 +11005773 if (mddev->level == 5 &&
5774 mddev->layout == ALGORITHM_PARITY_N) {
5775 mddev->new_layout = 0;
5776 mddev->new_level = 4;
5777 return setup_conf(mddev);
5778 }
5779 return ERR_PTR(-EINVAL);
5780}
NeilBrownd562b0c2009-03-31 14:39:39 +11005781
NeilBrown245f46c2009-03-31 14:39:39 +11005782static struct mdk_personality raid5_personality;
5783
5784static void *raid6_takeover(mddev_t *mddev)
5785{
5786 /* Currently can only take over a raid5. We map the
5787 * personality to an equivalent raid6 personality
5788 * with the Q block at the end.
5789 */
5790 int new_layout;
5791
5792 if (mddev->pers != &raid5_personality)
5793 return ERR_PTR(-EINVAL);
5794 if (mddev->degraded > 1)
5795 return ERR_PTR(-EINVAL);
5796 if (mddev->raid_disks > 253)
5797 return ERR_PTR(-EINVAL);
5798 if (mddev->raid_disks < 3)
5799 return ERR_PTR(-EINVAL);
5800
5801 switch (mddev->layout) {
5802 case ALGORITHM_LEFT_ASYMMETRIC:
5803 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5804 break;
5805 case ALGORITHM_RIGHT_ASYMMETRIC:
5806 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5807 break;
5808 case ALGORITHM_LEFT_SYMMETRIC:
5809 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5810 break;
5811 case ALGORITHM_RIGHT_SYMMETRIC:
5812 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5813 break;
5814 case ALGORITHM_PARITY_0:
5815 new_layout = ALGORITHM_PARITY_0_6;
5816 break;
5817 case ALGORITHM_PARITY_N:
5818 new_layout = ALGORITHM_PARITY_N;
5819 break;
5820 default:
5821 return ERR_PTR(-EINVAL);
5822 }
5823 mddev->new_level = 6;
5824 mddev->new_layout = new_layout;
5825 mddev->delta_disks = 1;
5826 mddev->raid_disks += 1;
5827 return setup_conf(mddev);
5828}
5829
5830
NeilBrown16a53ec2006-06-26 00:27:38 -07005831static struct mdk_personality raid6_personality =
5832{
5833 .name = "raid6",
5834 .level = 6,
5835 .owner = THIS_MODULE,
5836 .make_request = make_request,
5837 .run = run,
5838 .stop = stop,
5839 .status = status,
5840 .error_handler = error,
5841 .hot_add_disk = raid5_add_disk,
5842 .hot_remove_disk= raid5_remove_disk,
5843 .spare_active = raid5_spare_active,
5844 .sync_request = sync_request,
5845 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005846 .size = raid5_size,
NeilBrown50ac1682009-06-18 08:47:55 +10005847 .check_reshape = raid6_check_reshape,
NeilBrownf4168852007-02-28 20:11:53 -08005848 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005849 .finish_reshape = raid5_finish_reshape,
NeilBrown16a53ec2006-06-26 00:27:38 -07005850 .quiesce = raid5_quiesce,
NeilBrown245f46c2009-03-31 14:39:39 +11005851 .takeover = raid6_takeover,
NeilBrown16a53ec2006-06-26 00:27:38 -07005852};
NeilBrown2604b702006-01-06 00:20:36 -08005853static struct mdk_personality raid5_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005854{
5855 .name = "raid5",
NeilBrown2604b702006-01-06 00:20:36 -08005856 .level = 5,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005857 .owner = THIS_MODULE,
5858 .make_request = make_request,
5859 .run = run,
5860 .stop = stop,
5861 .status = status,
5862 .error_handler = error,
5863 .hot_add_disk = raid5_add_disk,
5864 .hot_remove_disk= raid5_remove_disk,
5865 .spare_active = raid5_spare_active,
5866 .sync_request = sync_request,
5867 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005868 .size = raid5_size,
NeilBrown63c70c42006-03-27 01:18:13 -08005869 .check_reshape = raid5_check_reshape,
5870 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005871 .finish_reshape = raid5_finish_reshape,
NeilBrown72626682005-09-09 16:23:54 -07005872 .quiesce = raid5_quiesce,
NeilBrownd562b0c2009-03-31 14:39:39 +11005873 .takeover = raid5_takeover,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005874};
5875
NeilBrown2604b702006-01-06 00:20:36 -08005876static struct mdk_personality raid4_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -07005877{
NeilBrown2604b702006-01-06 00:20:36 -08005878 .name = "raid4",
5879 .level = 4,
5880 .owner = THIS_MODULE,
5881 .make_request = make_request,
5882 .run = run,
5883 .stop = stop,
5884 .status = status,
5885 .error_handler = error,
5886 .hot_add_disk = raid5_add_disk,
5887 .hot_remove_disk= raid5_remove_disk,
5888 .spare_active = raid5_spare_active,
5889 .sync_request = sync_request,
5890 .resize = raid5_resize,
Dan Williams80c3a6c2009-03-17 18:10:40 -07005891 .size = raid5_size,
NeilBrown3d378902007-03-26 21:32:13 -08005892 .check_reshape = raid5_check_reshape,
5893 .start_reshape = raid5_start_reshape,
NeilBrowncea9c222009-03-31 15:15:05 +11005894 .finish_reshape = raid5_finish_reshape,
NeilBrown2604b702006-01-06 00:20:36 -08005895 .quiesce = raid5_quiesce,
NeilBrowna78d38a2010-03-22 16:53:49 +11005896 .takeover = raid4_takeover,
NeilBrown2604b702006-01-06 00:20:36 -08005897};
5898
5899static int __init raid5_init(void)
5900{
NeilBrown16a53ec2006-06-26 00:27:38 -07005901 register_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005902 register_md_personality(&raid5_personality);
5903 register_md_personality(&raid4_personality);
5904 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005905}
5906
NeilBrown2604b702006-01-06 00:20:36 -08005907static void raid5_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005908{
NeilBrown16a53ec2006-06-26 00:27:38 -07005909 unregister_md_personality(&raid6_personality);
NeilBrown2604b702006-01-06 00:20:36 -08005910 unregister_md_personality(&raid5_personality);
5911 unregister_md_personality(&raid4_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005912}
5913
5914module_init(raid5_init);
5915module_exit(raid5_exit);
5916MODULE_LICENSE("GPL");
NeilBrown0efb9e62009-12-14 12:49:58 +11005917MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005918MODULE_ALIAS("md-personality-4"); /* RAID5 */
NeilBrownd9d166c2006-01-06 00:20:51 -08005919MODULE_ALIAS("md-raid5");
5920MODULE_ALIAS("md-raid4");
NeilBrown2604b702006-01-06 00:20:36 -08005921MODULE_ALIAS("md-level-5");
5922MODULE_ALIAS("md-level-4");
NeilBrown16a53ec2006-06-26 00:27:38 -07005923MODULE_ALIAS("md-personality-8"); /* RAID6 */
5924MODULE_ALIAS("md-raid6");
5925MODULE_ALIAS("md-level-6");
5926
5927/* This used to be two separate modules, they were: */
5928MODULE_ALIAS("raid5");
5929MODULE_ALIAS("raid6");