Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * raid6main.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 |
| 5 | * Copyright (C) 2002, 2003 H. Peter Anvin |
| 6 | * |
| 7 | * RAID-6 management functions. This code is derived from raid5.c. |
| 8 | * Last merge from raid5.c bkcvs version 1.79 (kernel 2.6.1). |
| 9 | * |
| 10 | * Thanks to Penguin Computing for making the RAID-6 development possible |
| 11 | * by donating a test server! |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2, or (at your option) |
| 16 | * any later version. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * (for example /usr/src/linux/COPYING); if not, write to the Free |
| 20 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 21 | */ |
| 22 | |
| 23 | |
| 24 | #include <linux/config.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/highmem.h> |
| 28 | #include <linux/bitops.h> |
| 29 | #include <asm/atomic.h> |
| 30 | #include "raid6.h" |
| 31 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 32 | #include <linux/raid/bitmap.h> |
| 33 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | /* |
| 35 | * Stripe cache |
| 36 | */ |
| 37 | |
| 38 | #define NR_STRIPES 256 |
| 39 | #define STRIPE_SIZE PAGE_SIZE |
| 40 | #define STRIPE_SHIFT (PAGE_SHIFT - 9) |
| 41 | #define STRIPE_SECTORS (STRIPE_SIZE>>9) |
| 42 | #define IO_THRESHOLD 1 |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 43 | #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #define HASH_MASK (NR_HASH - 1) |
| 45 | |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 46 | #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | /* bio's attached to a stripe+device for I/O are linked together in bi_sector |
| 49 | * order without overlap. There may be several bio's per stripe+device, and |
| 50 | * a bio could span several devices. |
| 51 | * When walking this list for a particular stripe+device, we must never proceed |
| 52 | * beyond a bio that extends past this device, as the next bio might no longer |
| 53 | * be valid. |
| 54 | * This macro is used to determine the 'next' bio in the list, given the sector |
| 55 | * of the current stripe+device |
| 56 | */ |
| 57 | #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) |
| 58 | /* |
| 59 | * The following can be used to debug the driver |
| 60 | */ |
| 61 | #define RAID6_DEBUG 0 /* Extremely verbose printk */ |
| 62 | #define RAID6_PARANOIA 1 /* Check spinlocks */ |
| 63 | #define RAID6_DUMPSTATE 0 /* Include stripe cache state in /proc/mdstat */ |
| 64 | #if RAID6_PARANOIA && defined(CONFIG_SMP) |
| 65 | # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) |
| 66 | #else |
| 67 | # define CHECK_DEVLOCK() |
| 68 | #endif |
| 69 | |
| 70 | #define PRINTK(x...) ((void)(RAID6_DEBUG && printk(KERN_DEBUG x))) |
| 71 | #if RAID6_DEBUG |
| 72 | #undef inline |
| 73 | #undef __inline__ |
| 74 | #define inline |
| 75 | #define __inline__ |
| 76 | #endif |
| 77 | |
| 78 | #if !RAID6_USE_EMPTY_ZERO_PAGE |
| 79 | /* In .bss so it's zeroed */ |
| 80 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); |
| 81 | #endif |
| 82 | |
| 83 | static inline int raid6_next_disk(int disk, int raid_disks) |
| 84 | { |
| 85 | disk++; |
| 86 | return (disk < raid_disks) ? disk : 0; |
| 87 | } |
| 88 | |
| 89 | static void print_raid6_conf (raid6_conf_t *conf); |
| 90 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 91 | static void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | { |
| 93 | if (atomic_dec_and_test(&sh->count)) { |
| 94 | if (!list_empty(&sh->lru)) |
| 95 | BUG(); |
| 96 | if (atomic_read(&conf->active_stripes)==0) |
| 97 | BUG(); |
| 98 | if (test_bit(STRIPE_HANDLE, &sh->state)) { |
| 99 | if (test_bit(STRIPE_DELAYED, &sh->state)) |
| 100 | list_add_tail(&sh->lru, &conf->delayed_list); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 101 | else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && |
| 102 | conf->seq_write == sh->bm_seq) |
| 103 | list_add_tail(&sh->lru, &conf->bitmap_list); |
| 104 | else { |
| 105 | clear_bit(STRIPE_BIT_DELAY, &sh->state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | list_add_tail(&sh->lru, &conf->handle_list); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 107 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | md_wakeup_thread(conf->mddev->thread); |
| 109 | } else { |
| 110 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
| 111 | atomic_dec(&conf->preread_active_stripes); |
| 112 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) |
| 113 | md_wakeup_thread(conf->mddev->thread); |
| 114 | } |
| 115 | list_add_tail(&sh->lru, &conf->inactive_list); |
| 116 | atomic_dec(&conf->active_stripes); |
| 117 | if (!conf->inactive_blocked || |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 118 | atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | wake_up(&conf->wait_for_stripe); |
| 120 | } |
| 121 | } |
| 122 | } |
| 123 | static void release_stripe(struct stripe_head *sh) |
| 124 | { |
| 125 | raid6_conf_t *conf = sh->raid_conf; |
| 126 | unsigned long flags; |
| 127 | |
| 128 | spin_lock_irqsave(&conf->device_lock, flags); |
| 129 | __release_stripe(conf, sh); |
| 130 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 131 | } |
| 132 | |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 133 | static inline void remove_hash(struct stripe_head *sh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | { |
| 135 | PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); |
| 136 | |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 137 | hlist_del_init(&sh->hash); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | } |
| 139 | |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 140 | static inline void insert_hash(raid6_conf_t *conf, struct stripe_head *sh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | { |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 142 | struct hlist_head *hp = stripe_hash(conf, sh->sector); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
| 144 | PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); |
| 145 | |
| 146 | CHECK_DEVLOCK(); |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 147 | hlist_add_head(&sh->hash, hp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | } |
| 149 | |
| 150 | |
| 151 | /* find an idle stripe, make sure it is unhashed, and return it. */ |
| 152 | static struct stripe_head *get_free_stripe(raid6_conf_t *conf) |
| 153 | { |
| 154 | struct stripe_head *sh = NULL; |
| 155 | struct list_head *first; |
| 156 | |
| 157 | CHECK_DEVLOCK(); |
| 158 | if (list_empty(&conf->inactive_list)) |
| 159 | goto out; |
| 160 | first = conf->inactive_list.next; |
| 161 | sh = list_entry(first, struct stripe_head, lru); |
| 162 | list_del_init(first); |
| 163 | remove_hash(sh); |
| 164 | atomic_inc(&conf->active_stripes); |
| 165 | out: |
| 166 | return sh; |
| 167 | } |
| 168 | |
| 169 | static void shrink_buffers(struct stripe_head *sh, int num) |
| 170 | { |
| 171 | struct page *p; |
| 172 | int i; |
| 173 | |
| 174 | for (i=0; i<num ; i++) { |
| 175 | p = sh->dev[i].page; |
| 176 | if (!p) |
| 177 | continue; |
| 178 | sh->dev[i].page = NULL; |
NeilBrown | 2d1f3b5 | 2006-01-06 00:20:31 -0800 | [diff] [blame] | 179 | put_page(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | } |
| 181 | } |
| 182 | |
| 183 | static int grow_buffers(struct stripe_head *sh, int num) |
| 184 | { |
| 185 | int i; |
| 186 | |
| 187 | for (i=0; i<num; i++) { |
| 188 | struct page *page; |
| 189 | |
| 190 | if (!(page = alloc_page(GFP_KERNEL))) { |
| 191 | return 1; |
| 192 | } |
| 193 | sh->dev[i].page = page; |
| 194 | } |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | static void raid6_build_block (struct stripe_head *sh, int i); |
| 199 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 200 | static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | { |
| 202 | raid6_conf_t *conf = sh->raid_conf; |
| 203 | int disks = conf->raid_disks, i; |
| 204 | |
| 205 | if (atomic_read(&sh->count) != 0) |
| 206 | BUG(); |
| 207 | if (test_bit(STRIPE_HANDLE, &sh->state)) |
| 208 | BUG(); |
| 209 | |
| 210 | CHECK_DEVLOCK(); |
| 211 | PRINTK("init_stripe called, stripe %llu\n", |
| 212 | (unsigned long long)sh->sector); |
| 213 | |
| 214 | remove_hash(sh); |
| 215 | |
| 216 | sh->sector = sector; |
| 217 | sh->pd_idx = pd_idx; |
| 218 | sh->state = 0; |
| 219 | |
| 220 | for (i=disks; i--; ) { |
| 221 | struct r5dev *dev = &sh->dev[i]; |
| 222 | |
| 223 | if (dev->toread || dev->towrite || dev->written || |
| 224 | test_bit(R5_LOCKED, &dev->flags)) { |
| 225 | PRINTK("sector=%llx i=%d %p %p %p %d\n", |
| 226 | (unsigned long long)sh->sector, i, dev->toread, |
| 227 | dev->towrite, dev->written, |
| 228 | test_bit(R5_LOCKED, &dev->flags)); |
| 229 | BUG(); |
| 230 | } |
| 231 | dev->flags = 0; |
| 232 | raid6_build_block(sh, i); |
| 233 | } |
| 234 | insert_hash(conf, sh); |
| 235 | } |
| 236 | |
| 237 | static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector) |
| 238 | { |
| 239 | struct stripe_head *sh; |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 240 | struct hlist_node *hn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | |
| 242 | CHECK_DEVLOCK(); |
| 243 | PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 244 | hlist_for_each_entry (sh, hn, stripe_hash(conf, sector), hash) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | if (sh->sector == sector) |
| 246 | return sh; |
| 247 | PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); |
| 248 | return NULL; |
| 249 | } |
| 250 | |
| 251 | static void unplug_slaves(mddev_t *mddev); |
| 252 | |
| 253 | static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector, |
| 254 | int pd_idx, int noblock) |
| 255 | { |
| 256 | struct stripe_head *sh; |
| 257 | |
| 258 | PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); |
| 259 | |
| 260 | spin_lock_irq(&conf->device_lock); |
| 261 | |
| 262 | do { |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 263 | wait_event_lock_irq(conf->wait_for_stripe, |
| 264 | conf->quiesce == 0, |
| 265 | conf->device_lock, /* nothing */); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | sh = __find_stripe(conf, sector); |
| 267 | if (!sh) { |
| 268 | if (!conf->inactive_blocked) |
| 269 | sh = get_free_stripe(conf); |
| 270 | if (noblock && sh == NULL) |
| 271 | break; |
| 272 | if (!sh) { |
| 273 | conf->inactive_blocked = 1; |
| 274 | wait_event_lock_irq(conf->wait_for_stripe, |
| 275 | !list_empty(&conf->inactive_list) && |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 276 | (atomic_read(&conf->active_stripes) |
| 277 | < (conf->max_nr_stripes *3/4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | || !conf->inactive_blocked), |
| 279 | conf->device_lock, |
| 280 | unplug_slaves(conf->mddev); |
| 281 | ); |
| 282 | conf->inactive_blocked = 0; |
| 283 | } else |
| 284 | init_stripe(sh, sector, pd_idx); |
| 285 | } else { |
| 286 | if (atomic_read(&sh->count)) { |
| 287 | if (!list_empty(&sh->lru)) |
| 288 | BUG(); |
| 289 | } else { |
| 290 | if (!test_bit(STRIPE_HANDLE, &sh->state)) |
| 291 | atomic_inc(&conf->active_stripes); |
| 292 | if (list_empty(&sh->lru)) |
| 293 | BUG(); |
| 294 | list_del_init(&sh->lru); |
| 295 | } |
| 296 | } |
| 297 | } while (sh == NULL); |
| 298 | |
| 299 | if (sh) |
| 300 | atomic_inc(&sh->count); |
| 301 | |
| 302 | spin_unlock_irq(&conf->device_lock); |
| 303 | return sh; |
| 304 | } |
| 305 | |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 306 | static int grow_one_stripe(raid6_conf_t *conf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | { |
| 308 | struct stripe_head *sh; |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 309 | sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); |
| 310 | if (!sh) |
| 311 | return 0; |
| 312 | memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); |
| 313 | sh->raid_conf = conf; |
| 314 | spin_lock_init(&sh->lock); |
| 315 | |
| 316 | if (grow_buffers(sh, conf->raid_disks)) { |
| 317 | shrink_buffers(sh, conf->raid_disks); |
| 318 | kmem_cache_free(conf->slab_cache, sh); |
| 319 | return 0; |
| 320 | } |
| 321 | /* we just created an active stripe so... */ |
| 322 | atomic_set(&sh->count, 1); |
| 323 | atomic_inc(&conf->active_stripes); |
| 324 | INIT_LIST_HEAD(&sh->lru); |
| 325 | release_stripe(sh); |
| 326 | return 1; |
| 327 | } |
| 328 | |
| 329 | static int grow_stripes(raid6_conf_t *conf, int num) |
| 330 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | kmem_cache_t *sc; |
| 332 | int devs = conf->raid_disks; |
| 333 | |
NeilBrown | ad01c9e | 2006-03-27 01:18:07 -0800 | [diff] [blame] | 334 | sprintf(conf->cache_name[0], "raid6/%s", mdname(conf->mddev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | |
NeilBrown | ad01c9e | 2006-03-27 01:18:07 -0800 | [diff] [blame] | 336 | sc = kmem_cache_create(conf->cache_name[0], |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), |
| 338 | 0, 0, NULL, NULL); |
| 339 | if (!sc) |
| 340 | return 1; |
| 341 | conf->slab_cache = sc; |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 342 | while (num--) |
| 343 | if (!grow_one_stripe(conf)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | return 0; |
| 346 | } |
| 347 | |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 348 | static int drop_one_stripe(raid6_conf_t *conf) |
| 349 | { |
| 350 | struct stripe_head *sh; |
| 351 | spin_lock_irq(&conf->device_lock); |
| 352 | sh = get_free_stripe(conf); |
| 353 | spin_unlock_irq(&conf->device_lock); |
| 354 | if (!sh) |
| 355 | return 0; |
| 356 | if (atomic_read(&sh->count)) |
| 357 | BUG(); |
| 358 | shrink_buffers(sh, conf->raid_disks); |
| 359 | kmem_cache_free(conf->slab_cache, sh); |
| 360 | atomic_dec(&conf->active_stripes); |
| 361 | return 1; |
| 362 | } |
| 363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | static void shrink_stripes(raid6_conf_t *conf) |
| 365 | { |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 366 | while (drop_one_stripe(conf)) |
| 367 | ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | |
NeilBrown | 29fc7e3 | 2006-02-03 03:03:41 -0800 | [diff] [blame] | 369 | if (conf->slab_cache) |
| 370 | kmem_cache_destroy(conf->slab_cache); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | conf->slab_cache = NULL; |
| 372 | } |
| 373 | |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 374 | static int raid6_end_read_request(struct bio * bi, unsigned int bytes_done, |
| 375 | int error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | { |
| 377 | struct stripe_head *sh = bi->bi_private; |
| 378 | raid6_conf_t *conf = sh->raid_conf; |
| 379 | int disks = conf->raid_disks, i; |
| 380 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| 381 | |
| 382 | if (bi->bi_size) |
| 383 | return 1; |
| 384 | |
| 385 | for (i=0 ; i<disks; i++) |
| 386 | if (bi == &sh->dev[i].req) |
| 387 | break; |
| 388 | |
| 389 | PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", |
| 390 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), |
| 391 | uptodate); |
| 392 | if (i == disks) { |
| 393 | BUG(); |
| 394 | return 0; |
| 395 | } |
| 396 | |
| 397 | if (uptodate) { |
| 398 | #if 0 |
| 399 | struct bio *bio; |
| 400 | unsigned long flags; |
| 401 | spin_lock_irqsave(&conf->device_lock, flags); |
| 402 | /* we can return a buffer if we bypassed the cache or |
| 403 | * if the top buffer is not in highmem. If there are |
| 404 | * multiple buffers, leave the extra work to |
| 405 | * handle_stripe |
| 406 | */ |
| 407 | buffer = sh->bh_read[i]; |
| 408 | if (buffer && |
| 409 | (!PageHighMem(buffer->b_page) |
| 410 | || buffer->b_page == bh->b_page ) |
| 411 | ) { |
| 412 | sh->bh_read[i] = buffer->b_reqnext; |
| 413 | buffer->b_reqnext = NULL; |
| 414 | } else |
| 415 | buffer = NULL; |
| 416 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 417 | if (sh->bh_page[i]==bh->b_page) |
| 418 | set_buffer_uptodate(bh); |
| 419 | if (buffer) { |
| 420 | if (buffer->b_page != bh->b_page) |
| 421 | memcpy(buffer->b_data, bh->b_data, bh->b_size); |
| 422 | buffer->b_end_io(buffer, 1); |
| 423 | } |
| 424 | #else |
| 425 | set_bit(R5_UPTODATE, &sh->dev[i].flags); |
| 426 | #endif |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 427 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
| 428 | printk(KERN_INFO "raid6: read error corrected!!\n"); |
| 429 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
| 430 | clear_bit(R5_ReWrite, &sh->dev[i].flags); |
| 431 | } |
| 432 | if (atomic_read(&conf->disks[i].rdev->read_errors)) |
| 433 | atomic_set(&conf->disks[i].rdev->read_errors, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | } else { |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 435 | int retry = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | clear_bit(R5_UPTODATE, &sh->dev[i].flags); |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 437 | atomic_inc(&conf->disks[i].rdev->read_errors); |
| 438 | if (conf->mddev->degraded) |
| 439 | printk(KERN_WARNING "raid6: read error not correctable.\n"); |
| 440 | else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) |
| 441 | /* Oh, no!!! */ |
| 442 | printk(KERN_WARNING "raid6: read error NOT corrected!!\n"); |
| 443 | else if (atomic_read(&conf->disks[i].rdev->read_errors) |
| 444 | > conf->max_nr_stripes) |
| 445 | printk(KERN_WARNING |
| 446 | "raid6: Too many read errors, failing device.\n"); |
| 447 | else |
| 448 | retry = 1; |
| 449 | if (retry) |
| 450 | set_bit(R5_ReadError, &sh->dev[i].flags); |
| 451 | else { |
| 452 | clear_bit(R5_ReadError, &sh->dev[i].flags); |
| 453 | clear_bit(R5_ReWrite, &sh->dev[i].flags); |
| 454 | md_error(conf->mddev, conf->disks[i].rdev); |
| 455 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); |
| 458 | #if 0 |
| 459 | /* must restore b_page before unlocking buffer... */ |
| 460 | if (sh->bh_page[i] != bh->b_page) { |
| 461 | bh->b_page = sh->bh_page[i]; |
| 462 | bh->b_data = page_address(bh->b_page); |
| 463 | clear_buffer_uptodate(bh); |
| 464 | } |
| 465 | #endif |
| 466 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
| 467 | set_bit(STRIPE_HANDLE, &sh->state); |
| 468 | release_stripe(sh); |
| 469 | return 0; |
| 470 | } |
| 471 | |
| 472 | static int raid6_end_write_request (struct bio *bi, unsigned int bytes_done, |
| 473 | int error) |
| 474 | { |
| 475 | struct stripe_head *sh = bi->bi_private; |
| 476 | raid6_conf_t *conf = sh->raid_conf; |
| 477 | int disks = conf->raid_disks, i; |
| 478 | unsigned long flags; |
| 479 | int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); |
| 480 | |
| 481 | if (bi->bi_size) |
| 482 | return 1; |
| 483 | |
| 484 | for (i=0 ; i<disks; i++) |
| 485 | if (bi == &sh->dev[i].req) |
| 486 | break; |
| 487 | |
| 488 | PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", |
| 489 | (unsigned long long)sh->sector, i, atomic_read(&sh->count), |
| 490 | uptodate); |
| 491 | if (i == disks) { |
| 492 | BUG(); |
| 493 | return 0; |
| 494 | } |
| 495 | |
| 496 | spin_lock_irqsave(&conf->device_lock, flags); |
| 497 | if (!uptodate) |
| 498 | md_error(conf->mddev, conf->disks[i].rdev); |
| 499 | |
| 500 | rdev_dec_pending(conf->disks[i].rdev, conf->mddev); |
| 501 | |
| 502 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
| 503 | set_bit(STRIPE_HANDLE, &sh->state); |
| 504 | __release_stripe(conf, sh); |
| 505 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 506 | return 0; |
| 507 | } |
| 508 | |
| 509 | |
| 510 | static sector_t compute_blocknr(struct stripe_head *sh, int i); |
| 511 | |
| 512 | static void raid6_build_block (struct stripe_head *sh, int i) |
| 513 | { |
| 514 | struct r5dev *dev = &sh->dev[i]; |
| 515 | int pd_idx = sh->pd_idx; |
| 516 | int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks); |
| 517 | |
| 518 | bio_init(&dev->req); |
| 519 | dev->req.bi_io_vec = &dev->vec; |
| 520 | dev->req.bi_vcnt++; |
| 521 | dev->req.bi_max_vecs++; |
| 522 | dev->vec.bv_page = dev->page; |
| 523 | dev->vec.bv_len = STRIPE_SIZE; |
| 524 | dev->vec.bv_offset = 0; |
| 525 | |
| 526 | dev->req.bi_sector = sh->sector; |
| 527 | dev->req.bi_private = sh; |
| 528 | |
| 529 | dev->flags = 0; |
| 530 | if (i != pd_idx && i != qd_idx) |
| 531 | dev->sector = compute_blocknr(sh, i); |
| 532 | } |
| 533 | |
| 534 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) |
| 535 | { |
| 536 | char b[BDEVNAME_SIZE]; |
| 537 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; |
| 538 | PRINTK("raid6: error called\n"); |
| 539 | |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 540 | if (!test_bit(Faulty, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | mddev->sb_dirty = 1; |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 542 | if (test_bit(In_sync, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | conf->working_disks--; |
| 544 | mddev->degraded++; |
| 545 | conf->failed_disks++; |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 546 | clear_bit(In_sync, &rdev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | /* |
| 548 | * if recovery was running, make sure it aborts. |
| 549 | */ |
| 550 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); |
| 551 | } |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 552 | set_bit(Faulty, &rdev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | printk (KERN_ALERT |
| 554 | "raid6: Disk failure on %s, disabling device." |
| 555 | " Operation continuing on %d devices\n", |
| 556 | bdevname(rdev->bdev,b), conf->working_disks); |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | /* |
| 561 | * Input: a 'big' sector number, |
| 562 | * Output: index of the data and parity disk, and the sector # in them. |
| 563 | */ |
| 564 | static sector_t raid6_compute_sector(sector_t r_sector, unsigned int raid_disks, |
| 565 | unsigned int data_disks, unsigned int * dd_idx, |
| 566 | unsigned int * pd_idx, raid6_conf_t *conf) |
| 567 | { |
| 568 | long stripe; |
| 569 | unsigned long chunk_number; |
| 570 | unsigned int chunk_offset; |
| 571 | sector_t new_sector; |
| 572 | int sectors_per_chunk = conf->chunk_size >> 9; |
| 573 | |
| 574 | /* First compute the information on this sector */ |
| 575 | |
| 576 | /* |
| 577 | * Compute the chunk number and the sector offset inside the chunk |
| 578 | */ |
| 579 | chunk_offset = sector_div(r_sector, sectors_per_chunk); |
| 580 | chunk_number = r_sector; |
| 581 | if ( r_sector != chunk_number ) { |
| 582 | printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n", |
| 583 | (unsigned long long)r_sector, (unsigned long)chunk_number); |
| 584 | BUG(); |
| 585 | } |
| 586 | |
| 587 | /* |
| 588 | * Compute the stripe number |
| 589 | */ |
| 590 | stripe = chunk_number / data_disks; |
| 591 | |
| 592 | /* |
| 593 | * Compute the data disk and parity disk indexes inside the stripe |
| 594 | */ |
| 595 | *dd_idx = chunk_number % data_disks; |
| 596 | |
| 597 | /* |
| 598 | * Select the parity disk based on the user selected algorithm. |
| 599 | */ |
| 600 | |
| 601 | /**** FIX THIS ****/ |
| 602 | switch (conf->algorithm) { |
| 603 | case ALGORITHM_LEFT_ASYMMETRIC: |
| 604 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); |
| 605 | if (*pd_idx == raid_disks-1) |
| 606 | (*dd_idx)++; /* Q D D D P */ |
| 607 | else if (*dd_idx >= *pd_idx) |
| 608 | (*dd_idx) += 2; /* D D P Q D */ |
| 609 | break; |
| 610 | case ALGORITHM_RIGHT_ASYMMETRIC: |
| 611 | *pd_idx = stripe % raid_disks; |
| 612 | if (*pd_idx == raid_disks-1) |
| 613 | (*dd_idx)++; /* Q D D D P */ |
| 614 | else if (*dd_idx >= *pd_idx) |
| 615 | (*dd_idx) += 2; /* D D P Q D */ |
| 616 | break; |
| 617 | case ALGORITHM_LEFT_SYMMETRIC: |
| 618 | *pd_idx = raid_disks - 1 - (stripe % raid_disks); |
| 619 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; |
| 620 | break; |
| 621 | case ALGORITHM_RIGHT_SYMMETRIC: |
| 622 | *pd_idx = stripe % raid_disks; |
| 623 | *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; |
| 624 | break; |
| 625 | default: |
| 626 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", |
| 627 | conf->algorithm); |
| 628 | } |
| 629 | |
| 630 | PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n", |
| 631 | chunk_number, *pd_idx, *dd_idx); |
| 632 | |
| 633 | /* |
| 634 | * Finally, compute the new sector number |
| 635 | */ |
| 636 | new_sector = (sector_t) stripe * sectors_per_chunk + chunk_offset; |
| 637 | return new_sector; |
| 638 | } |
| 639 | |
| 640 | |
| 641 | static sector_t compute_blocknr(struct stripe_head *sh, int i) |
| 642 | { |
| 643 | raid6_conf_t *conf = sh->raid_conf; |
| 644 | int raid_disks = conf->raid_disks, data_disks = raid_disks - 2; |
| 645 | sector_t new_sector = sh->sector, check; |
| 646 | int sectors_per_chunk = conf->chunk_size >> 9; |
| 647 | sector_t stripe; |
| 648 | int chunk_offset; |
| 649 | int chunk_number, dummy1, dummy2, dd_idx = i; |
| 650 | sector_t r_sector; |
| 651 | int i0 = i; |
| 652 | |
| 653 | chunk_offset = sector_div(new_sector, sectors_per_chunk); |
| 654 | stripe = new_sector; |
| 655 | if ( new_sector != stripe ) { |
| 656 | printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n", |
| 657 | (unsigned long long)new_sector, (unsigned long)stripe); |
| 658 | BUG(); |
| 659 | } |
| 660 | |
| 661 | switch (conf->algorithm) { |
| 662 | case ALGORITHM_LEFT_ASYMMETRIC: |
| 663 | case ALGORITHM_RIGHT_ASYMMETRIC: |
| 664 | if (sh->pd_idx == raid_disks-1) |
| 665 | i--; /* Q D D D P */ |
| 666 | else if (i > sh->pd_idx) |
| 667 | i -= 2; /* D D P Q D */ |
| 668 | break; |
| 669 | case ALGORITHM_LEFT_SYMMETRIC: |
| 670 | case ALGORITHM_RIGHT_SYMMETRIC: |
| 671 | if (sh->pd_idx == raid_disks-1) |
| 672 | i--; /* Q D D D P */ |
| 673 | else { |
| 674 | /* D D P Q D */ |
| 675 | if (i < sh->pd_idx) |
| 676 | i += raid_disks; |
| 677 | i -= (sh->pd_idx + 2); |
| 678 | } |
| 679 | break; |
| 680 | default: |
| 681 | printk (KERN_CRIT "raid6: unsupported algorithm %d\n", |
| 682 | conf->algorithm); |
| 683 | } |
| 684 | |
| 685 | PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i); |
| 686 | |
| 687 | chunk_number = stripe * data_disks + i; |
| 688 | r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; |
| 689 | |
| 690 | check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); |
| 691 | if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { |
| 692 | printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n"); |
| 693 | return 0; |
| 694 | } |
| 695 | return r_sector; |
| 696 | } |
| 697 | |
| 698 | |
| 699 | |
| 700 | /* |
| 701 | * Copy data between a page in the stripe cache, and one or more bion |
| 702 | * The page could align with the middle of the bio, or there could be |
| 703 | * several bion, each with several bio_vecs, which cover part of the page |
| 704 | * Multiple bion are linked together on bi_next. There may be extras |
| 705 | * at the end of this list. We ignore them. |
| 706 | */ |
| 707 | static void copy_data(int frombio, struct bio *bio, |
| 708 | struct page *page, |
| 709 | sector_t sector) |
| 710 | { |
| 711 | char *pa = page_address(page); |
| 712 | struct bio_vec *bvl; |
| 713 | int i; |
| 714 | int page_offset; |
| 715 | |
| 716 | if (bio->bi_sector >= sector) |
| 717 | page_offset = (signed)(bio->bi_sector - sector) * 512; |
| 718 | else |
| 719 | page_offset = (signed)(sector - bio->bi_sector) * -512; |
| 720 | bio_for_each_segment(bvl, bio, i) { |
| 721 | int len = bio_iovec_idx(bio,i)->bv_len; |
| 722 | int clen; |
| 723 | int b_offset = 0; |
| 724 | |
| 725 | if (page_offset < 0) { |
| 726 | b_offset = -page_offset; |
| 727 | page_offset += b_offset; |
| 728 | len -= b_offset; |
| 729 | } |
| 730 | |
| 731 | if (len > 0 && page_offset + len > STRIPE_SIZE) |
| 732 | clen = STRIPE_SIZE - page_offset; |
| 733 | else clen = len; |
| 734 | |
| 735 | if (clen > 0) { |
| 736 | char *ba = __bio_kmap_atomic(bio, i, KM_USER0); |
| 737 | if (frombio) |
| 738 | memcpy(pa+page_offset, ba+b_offset, clen); |
| 739 | else |
| 740 | memcpy(ba+b_offset, pa+page_offset, clen); |
| 741 | __bio_kunmap_atomic(ba, KM_USER0); |
| 742 | } |
| 743 | if (clen < len) /* hit end of page */ |
| 744 | break; |
| 745 | page_offset += len; |
| 746 | } |
| 747 | } |
| 748 | |
| 749 | #define check_xor() do { \ |
| 750 | if (count == MAX_XOR_BLOCKS) { \ |
| 751 | xor_block(count, STRIPE_SIZE, ptr); \ |
| 752 | count = 1; \ |
| 753 | } \ |
| 754 | } while(0) |
| 755 | |
| 756 | /* Compute P and Q syndromes */ |
| 757 | static void compute_parity(struct stripe_head *sh, int method) |
| 758 | { |
| 759 | raid6_conf_t *conf = sh->raid_conf; |
| 760 | int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; |
| 761 | struct bio *chosen; |
| 762 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ |
| 763 | void *ptrs[disks]; |
| 764 | |
| 765 | qd_idx = raid6_next_disk(pd_idx, disks); |
| 766 | d0_idx = raid6_next_disk(qd_idx, disks); |
| 767 | |
| 768 | PRINTK("compute_parity, stripe %llu, method %d\n", |
| 769 | (unsigned long long)sh->sector, method); |
| 770 | |
| 771 | switch(method) { |
| 772 | case READ_MODIFY_WRITE: |
| 773 | BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ |
| 774 | case RECONSTRUCT_WRITE: |
| 775 | for (i= disks; i-- ;) |
| 776 | if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { |
| 777 | chosen = sh->dev[i].towrite; |
| 778 | sh->dev[i].towrite = NULL; |
| 779 | |
| 780 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
| 781 | wake_up(&conf->wait_for_overlap); |
| 782 | |
| 783 | if (sh->dev[i].written) BUG(); |
| 784 | sh->dev[i].written = chosen; |
| 785 | } |
| 786 | break; |
| 787 | case CHECK_PARITY: |
| 788 | BUG(); /* Not implemented yet */ |
| 789 | } |
| 790 | |
| 791 | for (i = disks; i--;) |
| 792 | if (sh->dev[i].written) { |
| 793 | sector_t sector = sh->dev[i].sector; |
| 794 | struct bio *wbi = sh->dev[i].written; |
| 795 | while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { |
| 796 | copy_data(1, wbi, sh->dev[i].page, sector); |
| 797 | wbi = r5_next_bio(wbi, sector); |
| 798 | } |
| 799 | |
| 800 | set_bit(R5_LOCKED, &sh->dev[i].flags); |
| 801 | set_bit(R5_UPTODATE, &sh->dev[i].flags); |
| 802 | } |
| 803 | |
| 804 | // switch(method) { |
| 805 | // case RECONSTRUCT_WRITE: |
| 806 | // case CHECK_PARITY: |
| 807 | // case UPDATE_PARITY: |
| 808 | /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ |
| 809 | /* FIX: Is this ordering of drives even remotely optimal? */ |
| 810 | count = 0; |
| 811 | i = d0_idx; |
| 812 | do { |
| 813 | ptrs[count++] = page_address(sh->dev[i].page); |
| 814 | if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) |
| 815 | printk("block %d/%d not uptodate on parity calc\n", i,count); |
| 816 | i = raid6_next_disk(i, disks); |
| 817 | } while ( i != d0_idx ); |
| 818 | // break; |
| 819 | // } |
| 820 | |
| 821 | raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); |
| 822 | |
| 823 | switch(method) { |
| 824 | case RECONSTRUCT_WRITE: |
| 825 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); |
| 826 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); |
| 827 | set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); |
| 828 | set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); |
| 829 | break; |
| 830 | case UPDATE_PARITY: |
| 831 | set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); |
| 832 | set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); |
| 833 | break; |
| 834 | } |
| 835 | } |
| 836 | |
| 837 | /* Compute one missing block */ |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 838 | static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | { |
| 840 | raid6_conf_t *conf = sh->raid_conf; |
| 841 | int i, count, disks = conf->raid_disks; |
| 842 | void *ptr[MAX_XOR_BLOCKS], *p; |
| 843 | int pd_idx = sh->pd_idx; |
| 844 | int qd_idx = raid6_next_disk(pd_idx, disks); |
| 845 | |
| 846 | PRINTK("compute_block_1, stripe %llu, idx %d\n", |
| 847 | (unsigned long long)sh->sector, dd_idx); |
| 848 | |
| 849 | if ( dd_idx == qd_idx ) { |
| 850 | /* We're actually computing the Q drive */ |
| 851 | compute_parity(sh, UPDATE_PARITY); |
| 852 | } else { |
| 853 | ptr[0] = page_address(sh->dev[dd_idx].page); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 854 | if (!nozero) memset(ptr[0], 0, STRIPE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | count = 1; |
| 856 | for (i = disks ; i--; ) { |
| 857 | if (i == dd_idx || i == qd_idx) |
| 858 | continue; |
| 859 | p = page_address(sh->dev[i].page); |
| 860 | if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) |
| 861 | ptr[count++] = p; |
| 862 | else |
| 863 | printk("compute_block() %d, stripe %llu, %d" |
| 864 | " not present\n", dd_idx, |
| 865 | (unsigned long long)sh->sector, i); |
| 866 | |
| 867 | check_xor(); |
| 868 | } |
| 869 | if (count != 1) |
| 870 | xor_block(count, STRIPE_SIZE, ptr); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 871 | if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); |
| 872 | else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | } |
| 874 | } |
| 875 | |
| 876 | /* Compute two missing blocks */ |
| 877 | static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) |
| 878 | { |
| 879 | raid6_conf_t *conf = sh->raid_conf; |
| 880 | int i, count, disks = conf->raid_disks; |
| 881 | int pd_idx = sh->pd_idx; |
| 882 | int qd_idx = raid6_next_disk(pd_idx, disks); |
| 883 | int d0_idx = raid6_next_disk(qd_idx, disks); |
| 884 | int faila, failb; |
| 885 | |
| 886 | /* faila and failb are disk numbers relative to d0_idx */ |
| 887 | /* pd_idx become disks-2 and qd_idx become disks-1 */ |
| 888 | faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; |
| 889 | failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; |
| 890 | |
| 891 | BUG_ON(faila == failb); |
| 892 | if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } |
| 893 | |
| 894 | PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", |
| 895 | (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); |
| 896 | |
| 897 | if ( failb == disks-1 ) { |
| 898 | /* Q disk is one of the missing disks */ |
| 899 | if ( faila == disks-2 ) { |
| 900 | /* Missing P+Q, just recompute */ |
| 901 | compute_parity(sh, UPDATE_PARITY); |
| 902 | return; |
| 903 | } else { |
| 904 | /* We're missing D+Q; recompute D from P */ |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 905 | compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 906 | compute_parity(sh, UPDATE_PARITY); /* Is this necessary? */ |
| 907 | return; |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | /* We're missing D+P or D+D; build pointer table */ |
| 912 | { |
| 913 | /**** FIX THIS: This could be very bad if disks is close to 256 ****/ |
| 914 | void *ptrs[disks]; |
| 915 | |
| 916 | count = 0; |
| 917 | i = d0_idx; |
| 918 | do { |
| 919 | ptrs[count++] = page_address(sh->dev[i].page); |
| 920 | i = raid6_next_disk(i, disks); |
| 921 | if (i != dd_idx1 && i != dd_idx2 && |
| 922 | !test_bit(R5_UPTODATE, &sh->dev[i].flags)) |
| 923 | printk("compute_2 with missing block %d/%d\n", count, i); |
| 924 | } while ( i != d0_idx ); |
| 925 | |
| 926 | if ( failb == disks-2 ) { |
| 927 | /* We're missing D+P. */ |
| 928 | raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); |
| 929 | } else { |
| 930 | /* We're missing D+D. */ |
| 931 | raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); |
| 932 | } |
| 933 | |
| 934 | /* Both the above update both missing blocks */ |
| 935 | set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); |
| 936 | set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | |
| 941 | /* |
| 942 | * Each stripe/dev can have one or more bion attached. |
| 943 | * toread/towrite point to the first in a chain. |
| 944 | * The bi_next chain must be in order. |
| 945 | */ |
| 946 | static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) |
| 947 | { |
| 948 | struct bio **bip; |
| 949 | raid6_conf_t *conf = sh->raid_conf; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 950 | int firstwrite=0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 951 | |
| 952 | PRINTK("adding bh b#%llu to stripe s#%llu\n", |
| 953 | (unsigned long long)bi->bi_sector, |
| 954 | (unsigned long long)sh->sector); |
| 955 | |
| 956 | |
| 957 | spin_lock(&sh->lock); |
| 958 | spin_lock_irq(&conf->device_lock); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 959 | if (forwrite) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 960 | bip = &sh->dev[dd_idx].towrite; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 961 | if (*bip == NULL && sh->dev[dd_idx].written == NULL) |
| 962 | firstwrite = 1; |
| 963 | } else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | bip = &sh->dev[dd_idx].toread; |
| 965 | while (*bip && (*bip)->bi_sector < bi->bi_sector) { |
| 966 | if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) |
| 967 | goto overlap; |
| 968 | bip = &(*bip)->bi_next; |
| 969 | } |
| 970 | if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) |
| 971 | goto overlap; |
| 972 | |
| 973 | if (*bip && bi->bi_next && (*bip) != bi->bi_next) |
| 974 | BUG(); |
| 975 | if (*bip) |
| 976 | bi->bi_next = *bip; |
| 977 | *bip = bi; |
| 978 | bi->bi_phys_segments ++; |
| 979 | spin_unlock_irq(&conf->device_lock); |
| 980 | spin_unlock(&sh->lock); |
| 981 | |
| 982 | PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", |
| 983 | (unsigned long long)bi->bi_sector, |
| 984 | (unsigned long long)sh->sector, dd_idx); |
| 985 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 986 | if (conf->mddev->bitmap && firstwrite) { |
| 987 | sh->bm_seq = conf->seq_write; |
| 988 | bitmap_startwrite(conf->mddev->bitmap, sh->sector, |
| 989 | STRIPE_SECTORS, 0); |
| 990 | set_bit(STRIPE_BIT_DELAY, &sh->state); |
| 991 | } |
| 992 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | if (forwrite) { |
| 994 | /* check if page is covered */ |
| 995 | sector_t sector = sh->dev[dd_idx].sector; |
| 996 | for (bi=sh->dev[dd_idx].towrite; |
| 997 | sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && |
| 998 | bi && bi->bi_sector <= sector; |
| 999 | bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { |
| 1000 | if (bi->bi_sector + (bi->bi_size>>9) >= sector) |
| 1001 | sector = bi->bi_sector + (bi->bi_size>>9); |
| 1002 | } |
| 1003 | if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) |
| 1004 | set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); |
| 1005 | } |
| 1006 | return 1; |
| 1007 | |
| 1008 | overlap: |
| 1009 | set_bit(R5_Overlap, &sh->dev[dd_idx].flags); |
| 1010 | spin_unlock_irq(&conf->device_lock); |
| 1011 | spin_unlock(&sh->lock); |
| 1012 | return 0; |
| 1013 | } |
| 1014 | |
| 1015 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1016 | static int page_is_zero(struct page *p) |
| 1017 | { |
| 1018 | char *a = page_address(p); |
| 1019 | return ((*(u32*)a) == 0 && |
| 1020 | memcmp(a, a+4, STRIPE_SIZE-4)==0); |
| 1021 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | /* |
| 1023 | * handle_stripe - do things to a stripe. |
| 1024 | * |
| 1025 | * We lock the stripe and then examine the state of various bits |
| 1026 | * to see what needs to be done. |
| 1027 | * Possible results: |
| 1028 | * return some read request which now have data |
| 1029 | * return some write requests which are safely on disc |
| 1030 | * schedule a read on some buffers |
| 1031 | * schedule a write of some buffers |
| 1032 | * return confirmation of parity correctness |
| 1033 | * |
| 1034 | * Parity calculations are done inside the stripe lock |
| 1035 | * buffers are taken off read_list or write_list, and bh_cache buffers |
| 1036 | * get BH_Lock set before the stripe lock is released. |
| 1037 | * |
| 1038 | */ |
| 1039 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1040 | static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1041 | { |
| 1042 | raid6_conf_t *conf = sh->raid_conf; |
| 1043 | int disks = conf->raid_disks; |
| 1044 | struct bio *return_bi= NULL; |
| 1045 | struct bio *bi; |
| 1046 | int i; |
| 1047 | int syncing; |
| 1048 | int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; |
| 1049 | int non_overwrite = 0; |
| 1050 | int failed_num[2] = {0, 0}; |
| 1051 | struct r5dev *dev, *pdev, *qdev; |
| 1052 | int pd_idx = sh->pd_idx; |
| 1053 | int qd_idx = raid6_next_disk(pd_idx, disks); |
| 1054 | int p_failed, q_failed; |
| 1055 | |
| 1056 | PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", |
| 1057 | (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), |
| 1058 | pd_idx, qd_idx); |
| 1059 | |
| 1060 | spin_lock(&sh->lock); |
| 1061 | clear_bit(STRIPE_HANDLE, &sh->state); |
| 1062 | clear_bit(STRIPE_DELAYED, &sh->state); |
| 1063 | |
| 1064 | syncing = test_bit(STRIPE_SYNCING, &sh->state); |
| 1065 | /* Now to look around and see what can be done */ |
| 1066 | |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1067 | rcu_read_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | for (i=disks; i--; ) { |
| 1069 | mdk_rdev_t *rdev; |
| 1070 | dev = &sh->dev[i]; |
| 1071 | clear_bit(R5_Insync, &dev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1072 | |
| 1073 | PRINTK("check %d: state 0x%lx read %p write %p written %p\n", |
| 1074 | i, dev->flags, dev->toread, dev->towrite, dev->written); |
| 1075 | /* maybe we can reply to a read */ |
| 1076 | if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { |
| 1077 | struct bio *rbi, *rbi2; |
| 1078 | PRINTK("Return read for disc %d\n", i); |
| 1079 | spin_lock_irq(&conf->device_lock); |
| 1080 | rbi = dev->toread; |
| 1081 | dev->toread = NULL; |
| 1082 | if (test_and_clear_bit(R5_Overlap, &dev->flags)) |
| 1083 | wake_up(&conf->wait_for_overlap); |
| 1084 | spin_unlock_irq(&conf->device_lock); |
| 1085 | while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { |
| 1086 | copy_data(0, rbi, dev->page, dev->sector); |
| 1087 | rbi2 = r5_next_bio(rbi, dev->sector); |
| 1088 | spin_lock_irq(&conf->device_lock); |
| 1089 | if (--rbi->bi_phys_segments == 0) { |
| 1090 | rbi->bi_next = return_bi; |
| 1091 | return_bi = rbi; |
| 1092 | } |
| 1093 | spin_unlock_irq(&conf->device_lock); |
| 1094 | rbi = rbi2; |
| 1095 | } |
| 1096 | } |
| 1097 | |
| 1098 | /* now count some things */ |
| 1099 | if (test_bit(R5_LOCKED, &dev->flags)) locked++; |
| 1100 | if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; |
| 1101 | |
| 1102 | |
| 1103 | if (dev->toread) to_read++; |
| 1104 | if (dev->towrite) { |
| 1105 | to_write++; |
| 1106 | if (!test_bit(R5_OVERWRITE, &dev->flags)) |
| 1107 | non_overwrite++; |
| 1108 | } |
| 1109 | if (dev->written) written++; |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1110 | rdev = rcu_dereference(conf->disks[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 1111 | if (!rdev || !test_bit(In_sync, &rdev->flags)) { |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1112 | /* The ReadError flag will just be confusing now */ |
| 1113 | clear_bit(R5_ReadError, &dev->flags); |
| 1114 | clear_bit(R5_ReWrite, &dev->flags); |
| 1115 | } |
| 1116 | if (!rdev || !test_bit(In_sync, &rdev->flags) |
| 1117 | || test_bit(R5_ReadError, &dev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | if ( failed < 2 ) |
| 1119 | failed_num[failed] = i; |
| 1120 | failed++; |
| 1121 | } else |
| 1122 | set_bit(R5_Insync, &dev->flags); |
| 1123 | } |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1124 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1125 | PRINTK("locked=%d uptodate=%d to_read=%d" |
| 1126 | " to_write=%d failed=%d failed_num=%d,%d\n", |
| 1127 | locked, uptodate, to_read, to_write, failed, |
| 1128 | failed_num[0], failed_num[1]); |
| 1129 | /* check if the array has lost >2 devices and, if so, some requests might |
| 1130 | * need to be failed |
| 1131 | */ |
| 1132 | if (failed > 2 && to_read+to_write+written) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | for (i=disks; i--; ) { |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1134 | int bitmap_end = 0; |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1135 | |
| 1136 | if (test_bit(R5_ReadError, &sh->dev[i].flags)) { |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1137 | mdk_rdev_t *rdev; |
| 1138 | rcu_read_lock(); |
| 1139 | rdev = rcu_dereference(conf->disks[i].rdev); |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1140 | if (rdev && test_bit(In_sync, &rdev->flags)) |
| 1141 | /* multiple read failures in one stripe */ |
| 1142 | md_error(conf->mddev, rdev); |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1143 | rcu_read_unlock(); |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1144 | } |
| 1145 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1146 | spin_lock_irq(&conf->device_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | /* fail all writes first */ |
| 1148 | bi = sh->dev[i].towrite; |
| 1149 | sh->dev[i].towrite = NULL; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1150 | if (bi) { to_write--; bitmap_end = 1; } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | |
| 1152 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
| 1153 | wake_up(&conf->wait_for_overlap); |
| 1154 | |
| 1155 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ |
| 1156 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); |
| 1157 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
| 1158 | if (--bi->bi_phys_segments == 0) { |
| 1159 | md_write_end(conf->mddev); |
| 1160 | bi->bi_next = return_bi; |
| 1161 | return_bi = bi; |
| 1162 | } |
| 1163 | bi = nextbi; |
| 1164 | } |
| 1165 | /* and fail all 'written' */ |
| 1166 | bi = sh->dev[i].written; |
| 1167 | sh->dev[i].written = NULL; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1168 | if (bi) bitmap_end = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { |
| 1170 | struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); |
| 1171 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
| 1172 | if (--bi->bi_phys_segments == 0) { |
| 1173 | md_write_end(conf->mddev); |
| 1174 | bi->bi_next = return_bi; |
| 1175 | return_bi = bi; |
| 1176 | } |
| 1177 | bi = bi2; |
| 1178 | } |
| 1179 | |
| 1180 | /* fail any reads if this device is non-operational */ |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1181 | if (!test_bit(R5_Insync, &sh->dev[i].flags) || |
| 1182 | test_bit(R5_ReadError, &sh->dev[i].flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1183 | bi = sh->dev[i].toread; |
| 1184 | sh->dev[i].toread = NULL; |
| 1185 | if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
| 1186 | wake_up(&conf->wait_for_overlap); |
| 1187 | if (bi) to_read--; |
| 1188 | while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ |
| 1189 | struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); |
| 1190 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
| 1191 | if (--bi->bi_phys_segments == 0) { |
| 1192 | bi->bi_next = return_bi; |
| 1193 | return_bi = bi; |
| 1194 | } |
| 1195 | bi = nextbi; |
| 1196 | } |
| 1197 | } |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1198 | spin_unlock_irq(&conf->device_lock); |
| 1199 | if (bitmap_end) |
| 1200 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
| 1201 | STRIPE_SECTORS, 0, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | } |
| 1204 | if (failed > 2 && syncing) { |
| 1205 | md_done_sync(conf->mddev, STRIPE_SECTORS,0); |
| 1206 | clear_bit(STRIPE_SYNCING, &sh->state); |
| 1207 | syncing = 0; |
| 1208 | } |
| 1209 | |
| 1210 | /* |
| 1211 | * might be able to return some write requests if the parity blocks |
| 1212 | * are safe, or on a failed drive |
| 1213 | */ |
| 1214 | pdev = &sh->dev[pd_idx]; |
| 1215 | p_failed = (failed >= 1 && failed_num[0] == pd_idx) |
| 1216 | || (failed >= 2 && failed_num[1] == pd_idx); |
| 1217 | qdev = &sh->dev[qd_idx]; |
| 1218 | q_failed = (failed >= 1 && failed_num[0] == qd_idx) |
| 1219 | || (failed >= 2 && failed_num[1] == qd_idx); |
| 1220 | |
| 1221 | if ( written && |
| 1222 | ( p_failed || ((test_bit(R5_Insync, &pdev->flags) |
| 1223 | && !test_bit(R5_LOCKED, &pdev->flags) |
| 1224 | && test_bit(R5_UPTODATE, &pdev->flags))) ) && |
| 1225 | ( q_failed || ((test_bit(R5_Insync, &qdev->flags) |
| 1226 | && !test_bit(R5_LOCKED, &qdev->flags) |
| 1227 | && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { |
| 1228 | /* any written block on an uptodate or failed drive can be |
| 1229 | * returned. Note that if we 'wrote' to a failed drive, |
| 1230 | * it will be UPTODATE, but never LOCKED, so we don't need |
| 1231 | * to test 'failed' directly. |
| 1232 | */ |
| 1233 | for (i=disks; i--; ) |
| 1234 | if (sh->dev[i].written) { |
| 1235 | dev = &sh->dev[i]; |
| 1236 | if (!test_bit(R5_LOCKED, &dev->flags) && |
| 1237 | test_bit(R5_UPTODATE, &dev->flags) ) { |
| 1238 | /* We can return any write requests */ |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1239 | int bitmap_end = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1240 | struct bio *wbi, *wbi2; |
| 1241 | PRINTK("Return write for stripe %llu disc %d\n", |
| 1242 | (unsigned long long)sh->sector, i); |
| 1243 | spin_lock_irq(&conf->device_lock); |
| 1244 | wbi = dev->written; |
| 1245 | dev->written = NULL; |
| 1246 | while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { |
| 1247 | wbi2 = r5_next_bio(wbi, dev->sector); |
| 1248 | if (--wbi->bi_phys_segments == 0) { |
| 1249 | md_write_end(conf->mddev); |
| 1250 | wbi->bi_next = return_bi; |
| 1251 | return_bi = wbi; |
| 1252 | } |
| 1253 | wbi = wbi2; |
| 1254 | } |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1255 | if (dev->towrite == NULL) |
| 1256 | bitmap_end = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1257 | spin_unlock_irq(&conf->device_lock); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1258 | if (bitmap_end) |
| 1259 | bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
| 1260 | STRIPE_SECTORS, |
| 1261 | !test_bit(STRIPE_DEGRADED, &sh->state), 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1262 | } |
| 1263 | } |
| 1264 | } |
| 1265 | |
| 1266 | /* Now we might consider reading some blocks, either to check/generate |
| 1267 | * parity, or to satisfy requests |
| 1268 | * or to load a block that is being partially written. |
| 1269 | */ |
| 1270 | if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { |
| 1271 | for (i=disks; i--;) { |
| 1272 | dev = &sh->dev[i]; |
| 1273 | if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && |
| 1274 | (dev->toread || |
| 1275 | (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || |
| 1276 | syncing || |
| 1277 | (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || |
| 1278 | (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) |
| 1279 | ) |
| 1280 | ) { |
| 1281 | /* we would like to get this block, possibly |
| 1282 | * by computing it, but we might not be able to |
| 1283 | */ |
| 1284 | if (uptodate == disks-1) { |
| 1285 | PRINTK("Computing stripe %llu block %d\n", |
| 1286 | (unsigned long long)sh->sector, i); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1287 | compute_block_1(sh, i, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | uptodate++; |
| 1289 | } else if ( uptodate == disks-2 && failed >= 2 ) { |
| 1290 | /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ |
| 1291 | int other; |
| 1292 | for (other=disks; other--;) { |
| 1293 | if ( other == i ) |
| 1294 | continue; |
| 1295 | if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) |
| 1296 | break; |
| 1297 | } |
| 1298 | BUG_ON(other < 0); |
| 1299 | PRINTK("Computing stripe %llu blocks %d,%d\n", |
| 1300 | (unsigned long long)sh->sector, i, other); |
| 1301 | compute_block_2(sh, i, other); |
| 1302 | uptodate += 2; |
| 1303 | } else if (test_bit(R5_Insync, &dev->flags)) { |
| 1304 | set_bit(R5_LOCKED, &dev->flags); |
| 1305 | set_bit(R5_Wantread, &dev->flags); |
| 1306 | #if 0 |
| 1307 | /* if I am just reading this block and we don't have |
| 1308 | a failed drive, or any pending writes then sidestep the cache */ |
| 1309 | if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && |
| 1310 | ! syncing && !failed && !to_write) { |
| 1311 | sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; |
| 1312 | sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; |
| 1313 | } |
| 1314 | #endif |
| 1315 | locked++; |
| 1316 | PRINTK("Reading block %d (sync=%d)\n", |
| 1317 | i, syncing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | } |
| 1319 | } |
| 1320 | } |
| 1321 | set_bit(STRIPE_HANDLE, &sh->state); |
| 1322 | } |
| 1323 | |
| 1324 | /* now to consider writing and what else, if anything should be read */ |
| 1325 | if (to_write) { |
| 1326 | int rcw=0, must_compute=0; |
| 1327 | for (i=disks ; i--;) { |
| 1328 | dev = &sh->dev[i]; |
| 1329 | /* Would I have to read this buffer for reconstruct_write */ |
| 1330 | if (!test_bit(R5_OVERWRITE, &dev->flags) |
| 1331 | && i != pd_idx && i != qd_idx |
| 1332 | && (!test_bit(R5_LOCKED, &dev->flags) |
| 1333 | #if 0 |
| 1334 | || sh->bh_page[i] != bh->b_page |
| 1335 | #endif |
| 1336 | ) && |
| 1337 | !test_bit(R5_UPTODATE, &dev->flags)) { |
| 1338 | if (test_bit(R5_Insync, &dev->flags)) rcw++; |
| 1339 | else { |
| 1340 | PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); |
| 1341 | must_compute++; |
| 1342 | } |
| 1343 | } |
| 1344 | } |
| 1345 | PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", |
| 1346 | (unsigned long long)sh->sector, rcw, must_compute); |
| 1347 | set_bit(STRIPE_HANDLE, &sh->state); |
| 1348 | |
| 1349 | if (rcw > 0) |
| 1350 | /* want reconstruct write, but need to get some data */ |
| 1351 | for (i=disks; i--;) { |
| 1352 | dev = &sh->dev[i]; |
| 1353 | if (!test_bit(R5_OVERWRITE, &dev->flags) |
| 1354 | && !(failed == 0 && (i == pd_idx || i == qd_idx)) |
| 1355 | && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && |
| 1356 | test_bit(R5_Insync, &dev->flags)) { |
| 1357 | if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) |
| 1358 | { |
| 1359 | PRINTK("Read_old stripe %llu block %d for Reconstruct\n", |
| 1360 | (unsigned long long)sh->sector, i); |
| 1361 | set_bit(R5_LOCKED, &dev->flags); |
| 1362 | set_bit(R5_Wantread, &dev->flags); |
| 1363 | locked++; |
| 1364 | } else { |
| 1365 | PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", |
| 1366 | (unsigned long long)sh->sector, i); |
| 1367 | set_bit(STRIPE_DELAYED, &sh->state); |
| 1368 | set_bit(STRIPE_HANDLE, &sh->state); |
| 1369 | } |
| 1370 | } |
| 1371 | } |
| 1372 | /* now if nothing is locked, and if we have enough data, we can start a write request */ |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1373 | if (locked == 0 && rcw == 0 && |
| 1374 | !test_bit(STRIPE_BIT_DELAY, &sh->state)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | if ( must_compute > 0 ) { |
| 1376 | /* We have failed blocks and need to compute them */ |
| 1377 | switch ( failed ) { |
| 1378 | case 0: BUG(); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1379 | case 1: compute_block_1(sh, failed_num[0], 0); break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; |
| 1381 | default: BUG(); /* This request should have been failed? */ |
| 1382 | } |
| 1383 | } |
| 1384 | |
| 1385 | PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); |
| 1386 | compute_parity(sh, RECONSTRUCT_WRITE); |
| 1387 | /* now every locked buffer is ready to be written */ |
| 1388 | for (i=disks; i--;) |
| 1389 | if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { |
| 1390 | PRINTK("Writing stripe %llu block %d\n", |
| 1391 | (unsigned long long)sh->sector, i); |
| 1392 | locked++; |
| 1393 | set_bit(R5_Wantwrite, &sh->dev[i].flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | } |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1395 | /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ |
| 1396 | set_bit(STRIPE_INSYNC, &sh->state); |
| 1397 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1398 | if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { |
| 1399 | atomic_dec(&conf->preread_active_stripes); |
| 1400 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) |
| 1401 | md_wakeup_thread(conf->mddev->thread); |
| 1402 | } |
| 1403 | } |
| 1404 | } |
| 1405 | |
| 1406 | /* maybe we need to check and possibly fix the parity for this stripe |
| 1407 | * Any reads will already have been scheduled, so we just see if enough data |
| 1408 | * is available |
| 1409 | */ |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1410 | if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) { |
| 1411 | int update_p = 0, update_q = 0; |
| 1412 | struct r5dev *dev; |
| 1413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | set_bit(STRIPE_HANDLE, &sh->state); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1415 | |
| 1416 | BUG_ON(failed>2); |
| 1417 | BUG_ON(uptodate < disks); |
| 1418 | /* Want to check and possibly repair P and Q. |
| 1419 | * However there could be one 'failed' device, in which |
| 1420 | * case we can only check one of them, possibly using the |
| 1421 | * other to generate missing data |
| 1422 | */ |
| 1423 | |
| 1424 | /* If !tmp_page, we cannot do the calculations, |
| 1425 | * but as we have set STRIPE_HANDLE, we will soon be called |
| 1426 | * by stripe_handle with a tmp_page - just wait until then. |
| 1427 | */ |
| 1428 | if (tmp_page) { |
| 1429 | if (failed == q_failed) { |
| 1430 | /* The only possible failed device holds 'Q', so it makes |
| 1431 | * sense to check P (If anything else were failed, we would |
| 1432 | * have used P to recreate it). |
| 1433 | */ |
| 1434 | compute_block_1(sh, pd_idx, 1); |
| 1435 | if (!page_is_zero(sh->dev[pd_idx].page)) { |
| 1436 | compute_block_1(sh,pd_idx,0); |
| 1437 | update_p = 1; |
| 1438 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | } |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1440 | if (!q_failed && failed < 2) { |
| 1441 | /* q is not failed, and we didn't use it to generate |
| 1442 | * anything, so it makes sense to check it |
| 1443 | */ |
| 1444 | memcpy(page_address(tmp_page), |
| 1445 | page_address(sh->dev[qd_idx].page), |
| 1446 | STRIPE_SIZE); |
| 1447 | compute_parity(sh, UPDATE_PARITY); |
| 1448 | if (memcmp(page_address(tmp_page), |
| 1449 | page_address(sh->dev[qd_idx].page), |
| 1450 | STRIPE_SIZE)!= 0) { |
| 1451 | clear_bit(STRIPE_INSYNC, &sh->state); |
| 1452 | update_q = 1; |
| 1453 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | } |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1455 | if (update_p || update_q) { |
| 1456 | conf->mddev->resync_mismatches += STRIPE_SECTORS; |
| 1457 | if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) |
| 1458 | /* don't try to repair!! */ |
| 1459 | update_p = update_q = 0; |
| 1460 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1462 | /* now write out any block on a failed drive, |
| 1463 | * or P or Q if they need it |
| 1464 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1466 | if (failed == 2) { |
| 1467 | dev = &sh->dev[failed_num[1]]; |
| 1468 | locked++; |
| 1469 | set_bit(R5_LOCKED, &dev->flags); |
| 1470 | set_bit(R5_Wantwrite, &dev->flags); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1471 | } |
| 1472 | if (failed >= 1) { |
| 1473 | dev = &sh->dev[failed_num[0]]; |
| 1474 | locked++; |
| 1475 | set_bit(R5_LOCKED, &dev->flags); |
| 1476 | set_bit(R5_Wantwrite, &dev->flags); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1477 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1479 | if (update_p) { |
| 1480 | dev = &sh->dev[pd_idx]; |
| 1481 | locked ++; |
| 1482 | set_bit(R5_LOCKED, &dev->flags); |
| 1483 | set_bit(R5_Wantwrite, &dev->flags); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1484 | } |
| 1485 | if (update_q) { |
| 1486 | dev = &sh->dev[qd_idx]; |
| 1487 | locked++; |
| 1488 | set_bit(R5_LOCKED, &dev->flags); |
| 1489 | set_bit(R5_Wantwrite, &dev->flags); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1490 | } |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1491 | clear_bit(STRIPE_DEGRADED, &sh->state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | |
| 1493 | set_bit(STRIPE_INSYNC, &sh->state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | } |
| 1495 | } |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1496 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { |
| 1498 | md_done_sync(conf->mddev, STRIPE_SECTORS,1); |
| 1499 | clear_bit(STRIPE_SYNCING, &sh->state); |
| 1500 | } |
| 1501 | |
NeilBrown | d69762e | 2006-01-06 00:20:18 -0800 | [diff] [blame] | 1502 | /* If the failed drives are just a ReadError, then we might need |
| 1503 | * to progress the repair/check process |
| 1504 | */ |
| 1505 | if (failed <= 2 && ! conf->mddev->ro) |
| 1506 | for (i=0; i<failed;i++) { |
| 1507 | dev = &sh->dev[failed_num[i]]; |
| 1508 | if (test_bit(R5_ReadError, &dev->flags) |
| 1509 | && !test_bit(R5_LOCKED, &dev->flags) |
| 1510 | && test_bit(R5_UPTODATE, &dev->flags) |
| 1511 | ) { |
| 1512 | if (!test_bit(R5_ReWrite, &dev->flags)) { |
| 1513 | set_bit(R5_Wantwrite, &dev->flags); |
| 1514 | set_bit(R5_ReWrite, &dev->flags); |
| 1515 | set_bit(R5_LOCKED, &dev->flags); |
| 1516 | } else { |
| 1517 | /* let's read it back */ |
| 1518 | set_bit(R5_Wantread, &dev->flags); |
| 1519 | set_bit(R5_LOCKED, &dev->flags); |
| 1520 | } |
| 1521 | } |
| 1522 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1523 | spin_unlock(&sh->lock); |
| 1524 | |
| 1525 | while ((bi=return_bi)) { |
| 1526 | int bytes = bi->bi_size; |
| 1527 | |
| 1528 | return_bi = bi->bi_next; |
| 1529 | bi->bi_next = NULL; |
| 1530 | bi->bi_size = 0; |
| 1531 | bi->bi_end_io(bi, bytes, 0); |
| 1532 | } |
| 1533 | for (i=disks; i-- ;) { |
| 1534 | int rw; |
| 1535 | struct bio *bi; |
| 1536 | mdk_rdev_t *rdev; |
| 1537 | if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) |
| 1538 | rw = 1; |
| 1539 | else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) |
| 1540 | rw = 0; |
| 1541 | else |
| 1542 | continue; |
| 1543 | |
| 1544 | bi = &sh->dev[i].req; |
| 1545 | |
| 1546 | bi->bi_rw = rw; |
| 1547 | if (rw) |
| 1548 | bi->bi_end_io = raid6_end_write_request; |
| 1549 | else |
| 1550 | bi->bi_end_io = raid6_end_read_request; |
| 1551 | |
| 1552 | rcu_read_lock(); |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 1553 | rdev = rcu_dereference(conf->disks[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 1554 | if (rdev && test_bit(Faulty, &rdev->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | rdev = NULL; |
| 1556 | if (rdev) |
| 1557 | atomic_inc(&rdev->nr_pending); |
| 1558 | rcu_read_unlock(); |
| 1559 | |
| 1560 | if (rdev) { |
NeilBrown | 9910f16 | 2006-01-06 00:20:24 -0800 | [diff] [blame] | 1561 | if (syncing) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | md_sync_acct(rdev->bdev, STRIPE_SECTORS); |
| 1563 | |
| 1564 | bi->bi_bdev = rdev->bdev; |
| 1565 | PRINTK("for %llu schedule op %ld on disc %d\n", |
| 1566 | (unsigned long long)sh->sector, bi->bi_rw, i); |
| 1567 | atomic_inc(&sh->count); |
| 1568 | bi->bi_sector = sh->sector + rdev->data_offset; |
| 1569 | bi->bi_flags = 1 << BIO_UPTODATE; |
| 1570 | bi->bi_vcnt = 1; |
| 1571 | bi->bi_max_vecs = 1; |
| 1572 | bi->bi_idx = 0; |
| 1573 | bi->bi_io_vec = &sh->dev[i].vec; |
| 1574 | bi->bi_io_vec[0].bv_len = STRIPE_SIZE; |
| 1575 | bi->bi_io_vec[0].bv_offset = 0; |
| 1576 | bi->bi_size = STRIPE_SIZE; |
| 1577 | bi->bi_next = NULL; |
NeilBrown | 4dbcdc7 | 2006-01-06 00:20:52 -0800 | [diff] [blame] | 1578 | if (rw == WRITE && |
| 1579 | test_bit(R5_ReWrite, &sh->dev[i].flags)) |
| 1580 | atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1581 | generic_make_request(bi); |
| 1582 | } else { |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1583 | if (rw == 1) |
| 1584 | set_bit(STRIPE_DEGRADED, &sh->state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1585 | PRINTK("skip op %ld on disc %d for sector %llu\n", |
| 1586 | bi->bi_rw, i, (unsigned long long)sh->sector); |
| 1587 | clear_bit(R5_LOCKED, &sh->dev[i].flags); |
| 1588 | set_bit(STRIPE_HANDLE, &sh->state); |
| 1589 | } |
| 1590 | } |
| 1591 | } |
| 1592 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1593 | static void raid6_activate_delayed(raid6_conf_t *conf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | { |
| 1595 | if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { |
| 1596 | while (!list_empty(&conf->delayed_list)) { |
| 1597 | struct list_head *l = conf->delayed_list.next; |
| 1598 | struct stripe_head *sh; |
| 1599 | sh = list_entry(l, struct stripe_head, lru); |
| 1600 | list_del_init(l); |
| 1601 | clear_bit(STRIPE_DELAYED, &sh->state); |
| 1602 | if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) |
| 1603 | atomic_inc(&conf->preread_active_stripes); |
| 1604 | list_add_tail(&sh->lru, &conf->handle_list); |
| 1605 | } |
| 1606 | } |
| 1607 | } |
| 1608 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1609 | static void activate_bit_delay(raid6_conf_t *conf) |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1610 | { |
| 1611 | /* device_lock is held */ |
| 1612 | struct list_head head; |
| 1613 | list_add(&head, &conf->bitmap_list); |
| 1614 | list_del_init(&conf->bitmap_list); |
| 1615 | while (!list_empty(&head)) { |
| 1616 | struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); |
| 1617 | list_del_init(&sh->lru); |
| 1618 | atomic_inc(&sh->count); |
| 1619 | __release_stripe(conf, sh); |
| 1620 | } |
| 1621 | } |
| 1622 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1623 | static void unplug_slaves(mddev_t *mddev) |
| 1624 | { |
| 1625 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1626 | int i; |
| 1627 | |
| 1628 | rcu_read_lock(); |
| 1629 | for (i=0; i<mddev->raid_disks; i++) { |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 1630 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 1631 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1632 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
| 1633 | |
| 1634 | atomic_inc(&rdev->nr_pending); |
| 1635 | rcu_read_unlock(); |
| 1636 | |
| 1637 | if (r_queue->unplug_fn) |
| 1638 | r_queue->unplug_fn(r_queue); |
| 1639 | |
| 1640 | rdev_dec_pending(rdev, mddev); |
| 1641 | rcu_read_lock(); |
| 1642 | } |
| 1643 | } |
| 1644 | rcu_read_unlock(); |
| 1645 | } |
| 1646 | |
| 1647 | static void raid6_unplug_device(request_queue_t *q) |
| 1648 | { |
| 1649 | mddev_t *mddev = q->queuedata; |
| 1650 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1651 | unsigned long flags; |
| 1652 | |
| 1653 | spin_lock_irqsave(&conf->device_lock, flags); |
| 1654 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1655 | if (blk_remove_plug(q)) { |
| 1656 | conf->seq_flush++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | raid6_activate_delayed(conf); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1658 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | md_wakeup_thread(mddev->thread); |
| 1660 | |
| 1661 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 1662 | |
| 1663 | unplug_slaves(mddev); |
| 1664 | } |
| 1665 | |
| 1666 | static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk, |
| 1667 | sector_t *error_sector) |
| 1668 | { |
| 1669 | mddev_t *mddev = q->queuedata; |
| 1670 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1671 | int i, ret = 0; |
| 1672 | |
| 1673 | rcu_read_lock(); |
| 1674 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 1675 | mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 1676 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1677 | struct block_device *bdev = rdev->bdev; |
| 1678 | request_queue_t *r_queue = bdev_get_queue(bdev); |
| 1679 | |
| 1680 | if (!r_queue->issue_flush_fn) |
| 1681 | ret = -EOPNOTSUPP; |
| 1682 | else { |
| 1683 | atomic_inc(&rdev->nr_pending); |
| 1684 | rcu_read_unlock(); |
| 1685 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, |
| 1686 | error_sector); |
| 1687 | rdev_dec_pending(rdev, mddev); |
| 1688 | rcu_read_lock(); |
| 1689 | } |
| 1690 | } |
| 1691 | } |
| 1692 | rcu_read_unlock(); |
| 1693 | return ret; |
| 1694 | } |
| 1695 | |
| 1696 | static inline void raid6_plug_device(raid6_conf_t *conf) |
| 1697 | { |
| 1698 | spin_lock_irq(&conf->device_lock); |
| 1699 | blk_plug_device(conf->mddev->queue); |
| 1700 | spin_unlock_irq(&conf->device_lock); |
| 1701 | } |
| 1702 | |
| 1703 | static int make_request (request_queue_t *q, struct bio * bi) |
| 1704 | { |
| 1705 | mddev_t *mddev = q->queuedata; |
| 1706 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1707 | const unsigned int raid_disks = conf->raid_disks; |
| 1708 | const unsigned int data_disks = raid_disks - 2; |
| 1709 | unsigned int dd_idx, pd_idx; |
| 1710 | sector_t new_sector; |
| 1711 | sector_t logical_sector, last_sector; |
| 1712 | struct stripe_head *sh; |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 1713 | const int rw = bio_data_dir(bi); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1714 | |
NeilBrown | e5dcdd8 | 2005-09-09 16:23:41 -0700 | [diff] [blame] | 1715 | if (unlikely(bio_barrier(bi))) { |
| 1716 | bio_endio(bi, bi->bi_size, -EOPNOTSUPP); |
| 1717 | return 0; |
| 1718 | } |
| 1719 | |
NeilBrown | 3d310eb | 2005-06-21 17:17:26 -0700 | [diff] [blame] | 1720 | md_write_start(mddev, bi); |
NeilBrown | 06d91a5 | 2005-06-21 17:17:12 -0700 | [diff] [blame] | 1721 | |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 1722 | disk_stat_inc(mddev->gendisk, ios[rw]); |
| 1723 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | |
| 1725 | logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); |
| 1726 | last_sector = bi->bi_sector + (bi->bi_size>>9); |
| 1727 | |
| 1728 | bi->bi_next = NULL; |
| 1729 | bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ |
NeilBrown | 06d91a5 | 2005-06-21 17:17:12 -0700 | [diff] [blame] | 1730 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1731 | for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { |
| 1732 | DEFINE_WAIT(w); |
| 1733 | |
| 1734 | new_sector = raid6_compute_sector(logical_sector, |
| 1735 | raid_disks, data_disks, &dd_idx, &pd_idx, conf); |
| 1736 | |
| 1737 | PRINTK("raid6: make_request, sector %llu logical %llu\n", |
| 1738 | (unsigned long long)new_sector, |
| 1739 | (unsigned long long)logical_sector); |
| 1740 | |
| 1741 | retry: |
| 1742 | prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); |
| 1743 | sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK)); |
| 1744 | if (sh) { |
| 1745 | if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { |
| 1746 | /* Add failed due to overlap. Flush everything |
| 1747 | * and wait a while |
| 1748 | */ |
| 1749 | raid6_unplug_device(mddev->queue); |
| 1750 | release_stripe(sh); |
| 1751 | schedule(); |
| 1752 | goto retry; |
| 1753 | } |
| 1754 | finish_wait(&conf->wait_for_overlap, &w); |
| 1755 | raid6_plug_device(conf); |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1756 | handle_stripe(sh, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1757 | release_stripe(sh); |
| 1758 | } else { |
| 1759 | /* cannot get stripe for read-ahead, just give-up */ |
| 1760 | clear_bit(BIO_UPTODATE, &bi->bi_flags); |
| 1761 | finish_wait(&conf->wait_for_overlap, &w); |
| 1762 | break; |
| 1763 | } |
| 1764 | |
| 1765 | } |
| 1766 | spin_lock_irq(&conf->device_lock); |
| 1767 | if (--bi->bi_phys_segments == 0) { |
| 1768 | int bytes = bi->bi_size; |
| 1769 | |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 1770 | if (rw == WRITE ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1771 | md_write_end(mddev); |
| 1772 | bi->bi_size = 0; |
| 1773 | bi->bi_end_io(bi, bytes, 0); |
| 1774 | } |
| 1775 | spin_unlock_irq(&conf->device_lock); |
| 1776 | return 0; |
| 1777 | } |
| 1778 | |
| 1779 | /* FIXME go_faster isn't used */ |
NeilBrown | 57afd89 | 2005-06-21 17:17:13 -0700 | [diff] [blame] | 1780 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1781 | { |
| 1782 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; |
| 1783 | struct stripe_head *sh; |
| 1784 | int sectors_per_chunk = conf->chunk_size >> 9; |
| 1785 | sector_t x; |
| 1786 | unsigned long stripe; |
| 1787 | int chunk_offset; |
| 1788 | int dd_idx, pd_idx; |
| 1789 | sector_t first_sector; |
| 1790 | int raid_disks = conf->raid_disks; |
| 1791 | int data_disks = raid_disks - 2; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1792 | sector_t max_sector = mddev->size << 1; |
| 1793 | int sync_blocks; |
NeilBrown | b5ab28a | 2005-11-28 13:44:11 -0800 | [diff] [blame] | 1794 | int still_degraded = 0; |
| 1795 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1796 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1797 | if (sector_nr >= max_sector) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1798 | /* just being told to finish up .. nothing much to do */ |
| 1799 | unplug_slaves(mddev); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1800 | |
| 1801 | if (mddev->curr_resync < max_sector) /* aborted */ |
| 1802 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, |
| 1803 | &sync_blocks, 1); |
NeilBrown | b5ab28a | 2005-11-28 13:44:11 -0800 | [diff] [blame] | 1804 | else /* completed sync */ |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1805 | conf->fullsync = 0; |
| 1806 | bitmap_close_sync(mddev->bitmap); |
| 1807 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | return 0; |
| 1809 | } |
| 1810 | /* if there are 2 or more failed drives and we are trying |
| 1811 | * to resync, then assert that we are finished, because there is |
| 1812 | * nothing we can do. |
| 1813 | */ |
| 1814 | if (mddev->degraded >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { |
NeilBrown | 57afd89 | 2005-06-21 17:17:13 -0700 | [diff] [blame] | 1815 | sector_t rv = (mddev->size << 1) - sector_nr; |
| 1816 | *skipped = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1817 | return rv; |
| 1818 | } |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1819 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1820 | !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1821 | !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { |
| 1822 | /* we can skip this block, and probably more */ |
| 1823 | sync_blocks /= STRIPE_SECTORS; |
| 1824 | *skipped = 1; |
| 1825 | return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ |
| 1826 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | |
| 1828 | x = sector_nr; |
| 1829 | chunk_offset = sector_div(x, sectors_per_chunk); |
| 1830 | stripe = x; |
| 1831 | BUG_ON(x != stripe); |
| 1832 | |
| 1833 | first_sector = raid6_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk |
| 1834 | + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); |
| 1835 | sh = get_active_stripe(conf, sector_nr, pd_idx, 1); |
| 1836 | if (sh == NULL) { |
| 1837 | sh = get_active_stripe(conf, sector_nr, pd_idx, 0); |
| 1838 | /* make sure we don't swamp the stripe cache if someone else |
| 1839 | * is trying to get access |
| 1840 | */ |
Nishanth Aravamudan | 66c006a | 2005-11-07 01:01:17 -0800 | [diff] [blame] | 1841 | schedule_timeout_uninterruptible(1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1842 | } |
NeilBrown | b5ab28a | 2005-11-28 13:44:11 -0800 | [diff] [blame] | 1843 | /* Need to check if array will still be degraded after recovery/resync |
| 1844 | * We don't need to check the 'failed' flag as when that gets set, |
| 1845 | * recovery aborts. |
| 1846 | */ |
| 1847 | for (i=0; i<mddev->raid_disks; i++) |
| 1848 | if (conf->disks[i].rdev == NULL) |
| 1849 | still_degraded = 1; |
| 1850 | |
| 1851 | bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); |
| 1852 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | spin_lock(&sh->lock); |
| 1854 | set_bit(STRIPE_SYNCING, &sh->state); |
| 1855 | clear_bit(STRIPE_INSYNC, &sh->state); |
| 1856 | spin_unlock(&sh->lock); |
| 1857 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1858 | handle_stripe(sh, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1859 | release_stripe(sh); |
| 1860 | |
| 1861 | return STRIPE_SECTORS; |
| 1862 | } |
| 1863 | |
| 1864 | /* |
| 1865 | * This is our raid6 kernel thread. |
| 1866 | * |
| 1867 | * We scan the hash table for stripes which can be handled now. |
| 1868 | * During the scan, completed stripes are saved for us by the interrupt |
| 1869 | * handler, so that they will not have to wait for our next wakeup. |
| 1870 | */ |
| 1871 | static void raid6d (mddev_t *mddev) |
| 1872 | { |
| 1873 | struct stripe_head *sh; |
| 1874 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1875 | int handled; |
| 1876 | |
| 1877 | PRINTK("+++ raid6d active\n"); |
| 1878 | |
| 1879 | md_check_recovery(mddev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1880 | |
| 1881 | handled = 0; |
| 1882 | spin_lock_irq(&conf->device_lock); |
| 1883 | while (1) { |
| 1884 | struct list_head *first; |
| 1885 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1886 | if (conf->seq_flush - conf->seq_write > 0) { |
| 1887 | int seq = conf->seq_flush; |
NeilBrown | 700e432 | 2005-11-28 13:44:10 -0800 | [diff] [blame] | 1888 | spin_unlock_irq(&conf->device_lock); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1889 | bitmap_unplug(mddev->bitmap); |
NeilBrown | 700e432 | 2005-11-28 13:44:10 -0800 | [diff] [blame] | 1890 | spin_lock_irq(&conf->device_lock); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1891 | conf->seq_write = seq; |
| 1892 | activate_bit_delay(conf); |
| 1893 | } |
| 1894 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1895 | if (list_empty(&conf->handle_list) && |
| 1896 | atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && |
| 1897 | !blk_queue_plugged(mddev->queue) && |
| 1898 | !list_empty(&conf->delayed_list)) |
| 1899 | raid6_activate_delayed(conf); |
| 1900 | |
| 1901 | if (list_empty(&conf->handle_list)) |
| 1902 | break; |
| 1903 | |
| 1904 | first = conf->handle_list.next; |
| 1905 | sh = list_entry(first, struct stripe_head, lru); |
| 1906 | |
| 1907 | list_del_init(first); |
| 1908 | atomic_inc(&sh->count); |
| 1909 | if (atomic_read(&sh->count)!= 1) |
| 1910 | BUG(); |
| 1911 | spin_unlock_irq(&conf->device_lock); |
| 1912 | |
| 1913 | handled++; |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 1914 | handle_stripe(sh, conf->spare_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1915 | release_stripe(sh); |
| 1916 | |
| 1917 | spin_lock_irq(&conf->device_lock); |
| 1918 | } |
| 1919 | PRINTK("%d stripes handled\n", handled); |
| 1920 | |
| 1921 | spin_unlock_irq(&conf->device_lock); |
| 1922 | |
| 1923 | unplug_slaves(mddev); |
| 1924 | |
| 1925 | PRINTK("--- raid6d inactive\n"); |
| 1926 | } |
| 1927 | |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 1928 | static ssize_t |
| 1929 | raid6_show_stripe_cache_size(mddev_t *mddev, char *page) |
| 1930 | { |
| 1931 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1932 | if (conf) |
| 1933 | return sprintf(page, "%d\n", conf->max_nr_stripes); |
| 1934 | else |
| 1935 | return 0; |
| 1936 | } |
| 1937 | |
| 1938 | static ssize_t |
| 1939 | raid6_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) |
| 1940 | { |
| 1941 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1942 | char *end; |
| 1943 | int new; |
| 1944 | if (len >= PAGE_SIZE) |
| 1945 | return -EINVAL; |
| 1946 | if (!conf) |
| 1947 | return -ENODEV; |
| 1948 | |
| 1949 | new = simple_strtoul(page, &end, 10); |
| 1950 | if (!*page || (*end && *end != '\n') ) |
| 1951 | return -EINVAL; |
| 1952 | if (new <= 16 || new > 32768) |
| 1953 | return -EINVAL; |
| 1954 | while (new < conf->max_nr_stripes) { |
| 1955 | if (drop_one_stripe(conf)) |
| 1956 | conf->max_nr_stripes--; |
| 1957 | else |
| 1958 | break; |
| 1959 | } |
| 1960 | while (new > conf->max_nr_stripes) { |
| 1961 | if (grow_one_stripe(conf)) |
| 1962 | conf->max_nr_stripes++; |
| 1963 | else break; |
| 1964 | } |
| 1965 | return len; |
| 1966 | } |
| 1967 | |
| 1968 | static struct md_sysfs_entry |
| 1969 | raid6_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, |
| 1970 | raid6_show_stripe_cache_size, |
| 1971 | raid6_store_stripe_cache_size); |
| 1972 | |
| 1973 | static ssize_t |
| 1974 | stripe_cache_active_show(mddev_t *mddev, char *page) |
| 1975 | { |
| 1976 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 1977 | if (conf) |
| 1978 | return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); |
| 1979 | else |
| 1980 | return 0; |
| 1981 | } |
| 1982 | |
| 1983 | static struct md_sysfs_entry |
| 1984 | raid6_stripecache_active = __ATTR_RO(stripe_cache_active); |
| 1985 | |
| 1986 | static struct attribute *raid6_attrs[] = { |
| 1987 | &raid6_stripecache_size.attr, |
| 1988 | &raid6_stripecache_active.attr, |
| 1989 | NULL, |
| 1990 | }; |
| 1991 | static struct attribute_group raid6_attrs_group = { |
| 1992 | .name = NULL, |
| 1993 | .attrs = raid6_attrs, |
| 1994 | }; |
| 1995 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 1996 | static int run(mddev_t *mddev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1997 | { |
| 1998 | raid6_conf_t *conf; |
| 1999 | int raid_disk, memory; |
| 2000 | mdk_rdev_t *rdev; |
| 2001 | struct disk_info *disk; |
| 2002 | struct list_head *tmp; |
| 2003 | |
| 2004 | if (mddev->level != 6) { |
| 2005 | PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level); |
| 2006 | return -EIO; |
| 2007 | } |
| 2008 | |
NeilBrown | b55e6bf | 2006-03-27 01:18:06 -0800 | [diff] [blame] | 2009 | mddev->private = kzalloc(sizeof (raid6_conf_t), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2010 | if ((conf = mddev->private) == NULL) |
| 2011 | goto abort; |
NeilBrown | b55e6bf | 2006-03-27 01:18:06 -0800 | [diff] [blame] | 2012 | conf->disks = kzalloc(mddev->raid_disks * sizeof(struct disk_info), |
| 2013 | GFP_KERNEL); |
| 2014 | if (!conf->disks) |
| 2015 | goto abort; |
| 2016 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | conf->mddev = mddev; |
| 2018 | |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 2019 | if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2020 | goto abort; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2021 | |
NeilBrown | ca65b73 | 2006-01-06 00:20:17 -0800 | [diff] [blame] | 2022 | conf->spare_page = alloc_page(GFP_KERNEL); |
| 2023 | if (!conf->spare_page) |
| 2024 | goto abort; |
| 2025 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2026 | spin_lock_init(&conf->device_lock); |
| 2027 | init_waitqueue_head(&conf->wait_for_stripe); |
| 2028 | init_waitqueue_head(&conf->wait_for_overlap); |
| 2029 | INIT_LIST_HEAD(&conf->handle_list); |
| 2030 | INIT_LIST_HEAD(&conf->delayed_list); |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 2031 | INIT_LIST_HEAD(&conf->bitmap_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2032 | INIT_LIST_HEAD(&conf->inactive_list); |
| 2033 | atomic_set(&conf->active_stripes, 0); |
| 2034 | atomic_set(&conf->preread_active_stripes, 0); |
| 2035 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2036 | PRINTK("raid6: run(%s) called.\n", mdname(mddev)); |
| 2037 | |
| 2038 | ITERATE_RDEV(mddev,rdev,tmp) { |
| 2039 | raid_disk = rdev->raid_disk; |
| 2040 | if (raid_disk >= mddev->raid_disks |
| 2041 | || raid_disk < 0) |
| 2042 | continue; |
| 2043 | disk = conf->disks + raid_disk; |
| 2044 | |
| 2045 | disk->rdev = rdev; |
| 2046 | |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2047 | if (test_bit(In_sync, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2048 | char b[BDEVNAME_SIZE]; |
| 2049 | printk(KERN_INFO "raid6: device %s operational as raid" |
| 2050 | " disk %d\n", bdevname(rdev->bdev,b), |
| 2051 | raid_disk); |
| 2052 | conf->working_disks++; |
| 2053 | } |
| 2054 | } |
| 2055 | |
| 2056 | conf->raid_disks = mddev->raid_disks; |
| 2057 | |
| 2058 | /* |
| 2059 | * 0 for a fully functional array, 1 or 2 for a degraded array. |
| 2060 | */ |
| 2061 | mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; |
| 2062 | conf->mddev = mddev; |
| 2063 | conf->chunk_size = mddev->chunk_size; |
| 2064 | conf->level = mddev->level; |
| 2065 | conf->algorithm = mddev->layout; |
| 2066 | conf->max_nr_stripes = NR_STRIPES; |
| 2067 | |
| 2068 | /* device size must be a multiple of chunk size */ |
| 2069 | mddev->size &= ~(mddev->chunk_size/1024 -1); |
NeilBrown | b158156 | 2005-07-31 22:34:50 -0700 | [diff] [blame] | 2070 | mddev->resync_max_sectors = mddev->size << 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2071 | |
| 2072 | if (conf->raid_disks < 4) { |
| 2073 | printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", |
| 2074 | mdname(mddev), conf->raid_disks); |
| 2075 | goto abort; |
| 2076 | } |
| 2077 | if (!conf->chunk_size || conf->chunk_size % 4) { |
| 2078 | printk(KERN_ERR "raid6: invalid chunk size %d for %s\n", |
| 2079 | conf->chunk_size, mdname(mddev)); |
| 2080 | goto abort; |
| 2081 | } |
| 2082 | if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { |
| 2083 | printk(KERN_ERR |
| 2084 | "raid6: unsupported parity algorithm %d for %s\n", |
| 2085 | conf->algorithm, mdname(mddev)); |
| 2086 | goto abort; |
| 2087 | } |
| 2088 | if (mddev->degraded > 2) { |
| 2089 | printk(KERN_ERR "raid6: not enough operational devices for %s" |
| 2090 | " (%d/%d failed)\n", |
| 2091 | mdname(mddev), conf->failed_disks, conf->raid_disks); |
| 2092 | goto abort; |
| 2093 | } |
| 2094 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2095 | if (mddev->degraded > 0 && |
| 2096 | mddev->recovery_cp != MaxSector) { |
NeilBrown | 6ff8d8ec | 2006-01-06 00:20:15 -0800 | [diff] [blame] | 2097 | if (mddev->ok_start_degraded) |
| 2098 | printk(KERN_WARNING "raid6: starting dirty degraded array:%s" |
| 2099 | "- data corruption possible.\n", |
| 2100 | mdname(mddev)); |
| 2101 | else { |
| 2102 | printk(KERN_ERR "raid6: cannot start dirty degraded array" |
| 2103 | " for %s\n", mdname(mddev)); |
| 2104 | goto abort; |
| 2105 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2106 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2107 | |
| 2108 | { |
| 2109 | mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6"); |
| 2110 | if (!mddev->thread) { |
| 2111 | printk(KERN_ERR |
| 2112 | "raid6: couldn't allocate thread for %s\n", |
| 2113 | mdname(mddev)); |
| 2114 | goto abort; |
| 2115 | } |
| 2116 | } |
| 2117 | |
| 2118 | memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + |
| 2119 | conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; |
| 2120 | if (grow_stripes(conf, conf->max_nr_stripes)) { |
| 2121 | printk(KERN_ERR |
| 2122 | "raid6: couldn't allocate %dkB for buffers\n", memory); |
| 2123 | shrink_stripes(conf); |
| 2124 | md_unregister_thread(mddev->thread); |
| 2125 | goto abort; |
| 2126 | } else |
| 2127 | printk(KERN_INFO "raid6: allocated %dkB for %s\n", |
| 2128 | memory, mdname(mddev)); |
| 2129 | |
| 2130 | if (mddev->degraded == 0) |
| 2131 | printk(KERN_INFO "raid6: raid level %d set %s active with %d out of %d" |
| 2132 | " devices, algorithm %d\n", conf->level, mdname(mddev), |
| 2133 | mddev->raid_disks-mddev->degraded, mddev->raid_disks, |
| 2134 | conf->algorithm); |
| 2135 | else |
| 2136 | printk(KERN_ALERT "raid6: raid level %d set %s active with %d" |
| 2137 | " out of %d devices, algorithm %d\n", conf->level, |
| 2138 | mdname(mddev), mddev->raid_disks - mddev->degraded, |
| 2139 | mddev->raid_disks, conf->algorithm); |
| 2140 | |
| 2141 | print_raid6_conf(conf); |
| 2142 | |
| 2143 | /* read-ahead size must cover two whole stripes, which is |
| 2144 | * 2 * (n-2) * chunksize where 'n' is the number of raid devices |
| 2145 | */ |
| 2146 | { |
| 2147 | int stripe = (mddev->raid_disks-2) * mddev->chunk_size |
NeilBrown | 2d1f3b5 | 2006-01-06 00:20:31 -0800 | [diff] [blame] | 2148 | / PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2149 | if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) |
| 2150 | mddev->queue->backing_dev_info.ra_pages = 2 * stripe; |
| 2151 | } |
| 2152 | |
| 2153 | /* Ok, everything is just fine now */ |
NeilBrown | ec350a7 | 2006-03-31 02:32:06 -0800 | [diff] [blame] | 2154 | sysfs_create_group(&mddev->kobj, &raid6_attrs_group); |
| 2155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2156 | mddev->array_size = mddev->size * (mddev->raid_disks - 2); |
NeilBrown | 7a5febe | 2005-05-16 21:53:16 -0700 | [diff] [blame] | 2157 | |
| 2158 | mddev->queue->unplug_fn = raid6_unplug_device; |
| 2159 | mddev->queue->issue_flush_fn = raid6_issue_flush; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2160 | return 0; |
| 2161 | abort: |
| 2162 | if (conf) { |
| 2163 | print_raid6_conf(conf); |
NeilBrown | 1345b1d | 2006-01-06 00:20:40 -0800 | [diff] [blame] | 2164 | safe_put_page(conf->spare_page); |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 2165 | kfree(conf->stripe_hashtbl); |
NeilBrown | b55e6bf | 2006-03-27 01:18:06 -0800 | [diff] [blame] | 2166 | kfree(conf->disks); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2167 | kfree(conf); |
| 2168 | } |
| 2169 | mddev->private = NULL; |
| 2170 | printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev)); |
| 2171 | return -EIO; |
| 2172 | } |
| 2173 | |
| 2174 | |
| 2175 | |
| 2176 | static int stop (mddev_t *mddev) |
| 2177 | { |
| 2178 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; |
| 2179 | |
| 2180 | md_unregister_thread(mddev->thread); |
| 2181 | mddev->thread = NULL; |
| 2182 | shrink_stripes(conf); |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 2183 | kfree(conf->stripe_hashtbl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2184 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
NeilBrown | 35849c7 | 2006-02-02 14:28:06 -0800 | [diff] [blame] | 2185 | sysfs_remove_group(&mddev->kobj, &raid6_attrs_group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2186 | kfree(conf); |
| 2187 | mddev->private = NULL; |
| 2188 | return 0; |
| 2189 | } |
| 2190 | |
| 2191 | #if RAID6_DUMPSTATE |
| 2192 | static void print_sh (struct seq_file *seq, struct stripe_head *sh) |
| 2193 | { |
| 2194 | int i; |
| 2195 | |
| 2196 | seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", |
| 2197 | (unsigned long long)sh->sector, sh->pd_idx, sh->state); |
| 2198 | seq_printf(seq, "sh %llu, count %d.\n", |
| 2199 | (unsigned long long)sh->sector, atomic_read(&sh->count)); |
| 2200 | seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); |
| 2201 | for (i = 0; i < sh->raid_conf->raid_disks; i++) { |
| 2202 | seq_printf(seq, "(cache%d: %p %ld) ", |
| 2203 | i, sh->dev[i].page, sh->dev[i].flags); |
| 2204 | } |
| 2205 | seq_printf(seq, "\n"); |
| 2206 | } |
| 2207 | |
| 2208 | static void printall (struct seq_file *seq, raid6_conf_t *conf) |
| 2209 | { |
| 2210 | struct stripe_head *sh; |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 2211 | struct hlist_node *hn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2212 | int i; |
| 2213 | |
| 2214 | spin_lock_irq(&conf->device_lock); |
| 2215 | for (i = 0; i < NR_HASH; i++) { |
| 2216 | sh = conf->stripe_hashtbl[i]; |
NeilBrown | fccddba | 2006-01-06 00:20:33 -0800 | [diff] [blame] | 2217 | hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2218 | if (sh->raid_conf != conf) |
| 2219 | continue; |
| 2220 | print_sh(seq, sh); |
| 2221 | } |
| 2222 | } |
| 2223 | spin_unlock_irq(&conf->device_lock); |
| 2224 | } |
| 2225 | #endif |
| 2226 | |
| 2227 | static void status (struct seq_file *seq, mddev_t *mddev) |
| 2228 | { |
| 2229 | raid6_conf_t *conf = (raid6_conf_t *) mddev->private; |
| 2230 | int i; |
| 2231 | |
| 2232 | seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); |
| 2233 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); |
| 2234 | for (i = 0; i < conf->raid_disks; i++) |
| 2235 | seq_printf (seq, "%s", |
| 2236 | conf->disks[i].rdev && |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2237 | test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2238 | seq_printf (seq, "]"); |
| 2239 | #if RAID6_DUMPSTATE |
| 2240 | seq_printf (seq, "\n"); |
| 2241 | printall(seq, conf); |
| 2242 | #endif |
| 2243 | } |
| 2244 | |
| 2245 | static void print_raid6_conf (raid6_conf_t *conf) |
| 2246 | { |
| 2247 | int i; |
| 2248 | struct disk_info *tmp; |
| 2249 | |
| 2250 | printk("RAID6 conf printout:\n"); |
| 2251 | if (!conf) { |
| 2252 | printk("(conf==NULL)\n"); |
| 2253 | return; |
| 2254 | } |
| 2255 | printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, |
| 2256 | conf->working_disks, conf->failed_disks); |
| 2257 | |
| 2258 | for (i = 0; i < conf->raid_disks; i++) { |
| 2259 | char b[BDEVNAME_SIZE]; |
| 2260 | tmp = conf->disks + i; |
| 2261 | if (tmp->rdev) |
| 2262 | printk(" disk %d, o:%d, dev:%s\n", |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2263 | i, !test_bit(Faulty, &tmp->rdev->flags), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2264 | bdevname(tmp->rdev->bdev,b)); |
| 2265 | } |
| 2266 | } |
| 2267 | |
| 2268 | static int raid6_spare_active(mddev_t *mddev) |
| 2269 | { |
| 2270 | int i; |
| 2271 | raid6_conf_t *conf = mddev->private; |
| 2272 | struct disk_info *tmp; |
| 2273 | |
| 2274 | for (i = 0; i < conf->raid_disks; i++) { |
| 2275 | tmp = conf->disks + i; |
| 2276 | if (tmp->rdev |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2277 | && !test_bit(Faulty, &tmp->rdev->flags) |
| 2278 | && !test_bit(In_sync, &tmp->rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2279 | mddev->degraded--; |
| 2280 | conf->failed_disks--; |
| 2281 | conf->working_disks++; |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2282 | set_bit(In_sync, &tmp->rdev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2283 | } |
| 2284 | } |
| 2285 | print_raid6_conf(conf); |
| 2286 | return 0; |
| 2287 | } |
| 2288 | |
| 2289 | static int raid6_remove_disk(mddev_t *mddev, int number) |
| 2290 | { |
| 2291 | raid6_conf_t *conf = mddev->private; |
| 2292 | int err = 0; |
| 2293 | mdk_rdev_t *rdev; |
| 2294 | struct disk_info *p = conf->disks + number; |
| 2295 | |
| 2296 | print_raid6_conf(conf); |
| 2297 | rdev = p->rdev; |
| 2298 | if (rdev) { |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2299 | if (test_bit(In_sync, &rdev->flags) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2300 | atomic_read(&rdev->nr_pending)) { |
| 2301 | err = -EBUSY; |
| 2302 | goto abort; |
| 2303 | } |
| 2304 | p->rdev = NULL; |
Paul E. McKenney | fbd568a3e | 2005-05-01 08:59:04 -0700 | [diff] [blame] | 2305 | synchronize_rcu(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2306 | if (atomic_read(&rdev->nr_pending)) { |
| 2307 | /* lost the race, try later */ |
| 2308 | err = -EBUSY; |
| 2309 | p->rdev = rdev; |
| 2310 | } |
| 2311 | } |
| 2312 | |
| 2313 | abort: |
| 2314 | |
| 2315 | print_raid6_conf(conf); |
| 2316 | return err; |
| 2317 | } |
| 2318 | |
| 2319 | static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) |
| 2320 | { |
| 2321 | raid6_conf_t *conf = mddev->private; |
| 2322 | int found = 0; |
| 2323 | int disk; |
| 2324 | struct disk_info *p; |
| 2325 | |
| 2326 | if (mddev->degraded > 2) |
| 2327 | /* no point adding a device */ |
| 2328 | return 0; |
| 2329 | /* |
NeilBrown | 6aea114a | 2005-11-28 13:44:13 -0800 | [diff] [blame] | 2330 | * find the disk ... but prefer rdev->saved_raid_disk |
| 2331 | * if possible. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2332 | */ |
NeilBrown | 6aea114a | 2005-11-28 13:44:13 -0800 | [diff] [blame] | 2333 | if (rdev->saved_raid_disk >= 0 && |
| 2334 | conf->disks[rdev->saved_raid_disk].rdev == NULL) |
| 2335 | disk = rdev->saved_raid_disk; |
| 2336 | else |
| 2337 | disk = 0; |
| 2338 | for ( ; disk < mddev->raid_disks; disk++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2339 | if ((p=conf->disks + disk)->rdev == NULL) { |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 2340 | clear_bit(In_sync, &rdev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2341 | rdev->raid_disk = disk; |
| 2342 | found = 1; |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 2343 | if (rdev->saved_raid_disk != disk) |
| 2344 | conf->fullsync = 1; |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 2345 | rcu_assign_pointer(p->rdev, rdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2346 | break; |
| 2347 | } |
| 2348 | print_raid6_conf(conf); |
| 2349 | return found; |
| 2350 | } |
| 2351 | |
| 2352 | static int raid6_resize(mddev_t *mddev, sector_t sectors) |
| 2353 | { |
| 2354 | /* no resync is happening, and there is enough space |
| 2355 | * on all devices, so we can resize. |
| 2356 | * We need to make sure resync covers any new space. |
| 2357 | * If the array is shrinking we should possibly wait until |
| 2358 | * any io in the removed space completes, but it hardly seems |
| 2359 | * worth it. |
| 2360 | */ |
| 2361 | sectors &= ~((sector_t)mddev->chunk_size/512 - 1); |
| 2362 | mddev->array_size = (sectors * (mddev->raid_disks-2))>>1; |
| 2363 | set_capacity(mddev->gendisk, mddev->array_size << 1); |
| 2364 | mddev->changed = 1; |
| 2365 | if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { |
| 2366 | mddev->recovery_cp = mddev->size << 1; |
| 2367 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); |
| 2368 | } |
| 2369 | mddev->size = sectors /2; |
NeilBrown | 4b5c7ae | 2005-07-27 11:43:28 -0700 | [diff] [blame] | 2370 | mddev->resync_max_sectors = sectors; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2371 | return 0; |
| 2372 | } |
| 2373 | |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 2374 | static void raid6_quiesce(mddev_t *mddev, int state) |
| 2375 | { |
| 2376 | raid6_conf_t *conf = mddev_to_conf(mddev); |
| 2377 | |
| 2378 | switch(state) { |
| 2379 | case 1: /* stop all writes */ |
| 2380 | spin_lock_irq(&conf->device_lock); |
| 2381 | conf->quiesce = 1; |
| 2382 | wait_event_lock_irq(conf->wait_for_stripe, |
| 2383 | atomic_read(&conf->active_stripes) == 0, |
| 2384 | conf->device_lock, /* nothing */); |
| 2385 | spin_unlock_irq(&conf->device_lock); |
| 2386 | break; |
| 2387 | |
| 2388 | case 0: /* re-enable writes */ |
| 2389 | spin_lock_irq(&conf->device_lock); |
| 2390 | conf->quiesce = 0; |
| 2391 | wake_up(&conf->wait_for_stripe); |
| 2392 | spin_unlock_irq(&conf->device_lock); |
| 2393 | break; |
| 2394 | } |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 2395 | } |
NeilBrown | b15c2e5 | 2006-01-06 00:20:16 -0800 | [diff] [blame] | 2396 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2397 | static struct mdk_personality raid6_personality = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2398 | { |
| 2399 | .name = "raid6", |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2400 | .level = 6, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2401 | .owner = THIS_MODULE, |
| 2402 | .make_request = make_request, |
| 2403 | .run = run, |
| 2404 | .stop = stop, |
| 2405 | .status = status, |
| 2406 | .error_handler = error, |
| 2407 | .hot_add_disk = raid6_add_disk, |
| 2408 | .hot_remove_disk= raid6_remove_disk, |
| 2409 | .spare_active = raid6_spare_active, |
| 2410 | .sync_request = sync_request, |
| 2411 | .resize = raid6_resize, |
NeilBrown | 934ce7c | 2005-09-09 16:23:55 -0700 | [diff] [blame] | 2412 | .quiesce = raid6_quiesce, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2413 | }; |
| 2414 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2415 | static int __init raid6_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2416 | { |
| 2417 | int e; |
| 2418 | |
| 2419 | e = raid6_select_algo(); |
| 2420 | if ( e ) |
| 2421 | return e; |
| 2422 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2423 | return register_md_personality(&raid6_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2424 | } |
| 2425 | |
| 2426 | static void raid6_exit (void) |
| 2427 | { |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2428 | unregister_md_personality(&raid6_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2429 | } |
| 2430 | |
| 2431 | module_init(raid6_init); |
| 2432 | module_exit(raid6_exit); |
| 2433 | MODULE_LICENSE("GPL"); |
| 2434 | MODULE_ALIAS("md-personality-8"); /* RAID6 */ |
NeilBrown | d9d166c | 2006-01-06 00:20:51 -0800 | [diff] [blame] | 2435 | MODULE_ALIAS("md-raid6"); |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 2436 | MODULE_ALIAS("md-level-6"); |