1 /* 2 * raid5.c : Multiple Devices driver for Linux 3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman 4 * Copyright (C) 1999, 2000 Ingo Molnar 5 * Copyright (C) 2002, 2003 H. Peter Anvin 6 * 7 * RAID-4/5/6 management functions. 8 * Thanks to Penguin Computing for making the RAID-6 development possible 9 * by donating a test server! 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2, or (at your option) 14 * any later version. 15 * 16 * You should have received a copy of the GNU General Public License 17 * (for example /usr/src/linux/COPYING); if not, write to the Free 18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 /* 22 * BITMAP UNPLUGGING: 23 * 24 * The sequencing for updating the bitmap reliably is a little 25 * subtle (and I got it wrong the first time) so it deserves some 26 * explanation. 27 * 28 * We group bitmap updates into batches. Each batch has a number. 29 * We may write out several batches at once, but that isn't very important. 30 * conf->bm_write is the number of the last batch successfully written. 31 * conf->bm_flush is the number of the last batch that was closed to 32 * new additions. 33 * When we discover that we will need to write to any block in a stripe 34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq 35 * the number of the batch it will be in. This is bm_flush+1. 36 * When we are ready to do a write, if that batch hasn't been written yet, 37 * we plug the array and queue the stripe for later. 38 * When an unplug happens, we increment bm_flush, thus closing the current 39 * batch. 40 * When we notice that bm_flush > bm_write, we write out all pending updates 41 * to the bitmap, and advance bm_write to where bm_flush was. 42 * This may occasionally write a bit out twice, but is sure never to 43 * miss any bits. 44 */ 45 46 #include <linux/module.h> 47 #include <linux/slab.h> 48 #include <linux/highmem.h> 49 #include <linux/bitops.h> 50 #include <linux/kthread.h> 51 #include <asm/atomic.h> 52 #include "raid6.h" 53 54 #include <linux/raid/bitmap.h> 55 56 /* 57 * Stripe cache 58 */ 59 60 #define NR_STRIPES 256 61 #define STRIPE_SIZE PAGE_SIZE 62 #define STRIPE_SHIFT (PAGE_SHIFT - 9) 63 #define STRIPE_SECTORS (STRIPE_SIZE>>9) 64 #define IO_THRESHOLD 1 65 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) 66 #define HASH_MASK (NR_HASH - 1) 67 68 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) 69 70 /* bio's attached to a stripe+device for I/O are linked together in bi_sector 71 * order without overlap. There may be several bio's per stripe+device, and 72 * a bio could span several devices. 73 * When walking this list for a particular stripe+device, we must never proceed 74 * beyond a bio that extends past this device, as the next bio might no longer 75 * be valid. 76 * This macro is used to determine the 'next' bio in the list, given the sector 77 * of the current stripe+device 78 */ 79 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) 80 /* 81 * The following can be used to debug the driver 82 */ 83 #define RAID5_DEBUG 0 84 #define RAID5_PARANOIA 1 85 #if RAID5_PARANOIA && defined(CONFIG_SMP) 86 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) 87 #else 88 # define CHECK_DEVLOCK() 89 #endif 90 91 #define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x))) 92 #if RAID5_DEBUG 93 #define inline 94 #define __inline__ 95 #endif 96 97 #if !RAID6_USE_EMPTY_ZERO_PAGE 98 /* In .bss so it's zeroed */ 99 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); 100 #endif 101 102 static inline int raid6_next_disk(int disk, int raid_disks) 103 { 104 disk++; 105 return (disk < raid_disks) ? disk : 0; 106 } 107 static void print_raid5_conf (raid5_conf_t *conf); 108 109 static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) 110 { 111 if (atomic_dec_and_test(&sh->count)) { 112 BUG_ON(!list_empty(&sh->lru)); 113 BUG_ON(atomic_read(&conf->active_stripes)==0); 114 if (test_bit(STRIPE_HANDLE, &sh->state)) { 115 if (test_bit(STRIPE_DELAYED, &sh->state)) { 116 list_add_tail(&sh->lru, &conf->delayed_list); 117 blk_plug_device(conf->mddev->queue); 118 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && 119 sh->bm_seq - conf->seq_write > 0) { 120 list_add_tail(&sh->lru, &conf->bitmap_list); 121 blk_plug_device(conf->mddev->queue); 122 } else { 123 clear_bit(STRIPE_BIT_DELAY, &sh->state); 124 list_add_tail(&sh->lru, &conf->handle_list); 125 } 126 md_wakeup_thread(conf->mddev->thread); 127 } else { 128 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 129 atomic_dec(&conf->preread_active_stripes); 130 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 131 md_wakeup_thread(conf->mddev->thread); 132 } 133 atomic_dec(&conf->active_stripes); 134 if (!test_bit(STRIPE_EXPANDING, &sh->state)) { 135 list_add_tail(&sh->lru, &conf->inactive_list); 136 wake_up(&conf->wait_for_stripe); 137 } 138 } 139 } 140 } 141 static void release_stripe(struct stripe_head *sh) 142 { 143 raid5_conf_t *conf = sh->raid_conf; 144 unsigned long flags; 145 146 spin_lock_irqsave(&conf->device_lock, flags); 147 __release_stripe(conf, sh); 148 spin_unlock_irqrestore(&conf->device_lock, flags); 149 } 150 151 static inline void remove_hash(struct stripe_head *sh) 152 { 153 PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); 154 155 hlist_del_init(&sh->hash); 156 } 157 158 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) 159 { 160 struct hlist_head *hp = stripe_hash(conf, sh->sector); 161 162 PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); 163 164 CHECK_DEVLOCK(); 165 hlist_add_head(&sh->hash, hp); 166 } 167 168 169 /* find an idle stripe, make sure it is unhashed, and return it. */ 170 static struct stripe_head *get_free_stripe(raid5_conf_t *conf) 171 { 172 struct stripe_head *sh = NULL; 173 struct list_head *first; 174 175 CHECK_DEVLOCK(); 176 if (list_empty(&conf->inactive_list)) 177 goto out; 178 first = conf->inactive_list.next; 179 sh = list_entry(first, struct stripe_head, lru); 180 list_del_init(first); 181 remove_hash(sh); 182 atomic_inc(&conf->active_stripes); 183 out: 184 return sh; 185 } 186 187 static void shrink_buffers(struct stripe_head *sh, int num) 188 { 189 struct page *p; 190 int i; 191 192 for (i=0; i<num ; i++) { 193 p = sh->dev[i].page; 194 if (!p) 195 continue; 196 sh->dev[i].page = NULL; 197 put_page(p); 198 } 199 } 200 201 static int grow_buffers(struct stripe_head *sh, int num) 202 { 203 int i; 204 205 for (i=0; i<num; i++) { 206 struct page *page; 207 208 if (!(page = alloc_page(GFP_KERNEL))) { 209 return 1; 210 } 211 sh->dev[i].page = page; 212 } 213 return 0; 214 } 215 216 static void raid5_build_block (struct stripe_head *sh, int i); 217 218 static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) 219 { 220 raid5_conf_t *conf = sh->raid_conf; 221 int i; 222 223 BUG_ON(atomic_read(&sh->count) != 0); 224 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); 225 226 CHECK_DEVLOCK(); 227 PRINTK("init_stripe called, stripe %llu\n", 228 (unsigned long long)sh->sector); 229 230 remove_hash(sh); 231 232 sh->sector = sector; 233 sh->pd_idx = pd_idx; 234 sh->state = 0; 235 236 sh->disks = disks; 237 238 for (i = sh->disks; i--; ) { 239 struct r5dev *dev = &sh->dev[i]; 240 241 if (dev->toread || dev->towrite || dev->written || 242 test_bit(R5_LOCKED, &dev->flags)) { 243 printk("sector=%llx i=%d %p %p %p %d\n", 244 (unsigned long long)sh->sector, i, dev->toread, 245 dev->towrite, dev->written, 246 test_bit(R5_LOCKED, &dev->flags)); 247 BUG(); 248 } 249 dev->flags = 0; 250 raid5_build_block(sh, i); 251 } 252 insert_hash(conf, sh); 253 } 254 255 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks) 256 { 257 struct stripe_head *sh; 258 struct hlist_node *hn; 259 260 CHECK_DEVLOCK(); 261 PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); 262 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) 263 if (sh->sector == sector && sh->disks == disks) 264 return sh; 265 PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); 266 return NULL; 267 } 268 269 static void unplug_slaves(mddev_t *mddev); 270 static void raid5_unplug_device(request_queue_t *q); 271 272 static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks, 273 int pd_idx, int noblock) 274 { 275 struct stripe_head *sh; 276 277 PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector); 278 279 spin_lock_irq(&conf->device_lock); 280 281 do { 282 wait_event_lock_irq(conf->wait_for_stripe, 283 conf->quiesce == 0, 284 conf->device_lock, /* nothing */); 285 sh = __find_stripe(conf, sector, disks); 286 if (!sh) { 287 if (!conf->inactive_blocked) 288 sh = get_free_stripe(conf); 289 if (noblock && sh == NULL) 290 break; 291 if (!sh) { 292 conf->inactive_blocked = 1; 293 wait_event_lock_irq(conf->wait_for_stripe, 294 !list_empty(&conf->inactive_list) && 295 (atomic_read(&conf->active_stripes) 296 < (conf->max_nr_stripes *3/4) 297 || !conf->inactive_blocked), 298 conf->device_lock, 299 raid5_unplug_device(conf->mddev->queue) 300 ); 301 conf->inactive_blocked = 0; 302 } else 303 init_stripe(sh, sector, pd_idx, disks); 304 } else { 305 if (atomic_read(&sh->count)) { 306 BUG_ON(!list_empty(&sh->lru)); 307 } else { 308 if (!test_bit(STRIPE_HANDLE, &sh->state)) 309 atomic_inc(&conf->active_stripes); 310 if (list_empty(&sh->lru) && 311 !test_bit(STRIPE_EXPANDING, &sh->state)) 312 BUG(); 313 list_del_init(&sh->lru); 314 } 315 } 316 } while (sh == NULL); 317 318 if (sh) 319 atomic_inc(&sh->count); 320 321 spin_unlock_irq(&conf->device_lock); 322 return sh; 323 } 324 325 static int grow_one_stripe(raid5_conf_t *conf) 326 { 327 struct stripe_head *sh; 328 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); 329 if (!sh) 330 return 0; 331 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); 332 sh->raid_conf = conf; 333 spin_lock_init(&sh->lock); 334 335 if (grow_buffers(sh, conf->raid_disks)) { 336 shrink_buffers(sh, conf->raid_disks); 337 kmem_cache_free(conf->slab_cache, sh); 338 return 0; 339 } 340 sh->disks = conf->raid_disks; 341 /* we just created an active stripe so... */ 342 atomic_set(&sh->count, 1); 343 atomic_inc(&conf->active_stripes); 344 INIT_LIST_HEAD(&sh->lru); 345 release_stripe(sh); 346 return 1; 347 } 348 349 static int grow_stripes(raid5_conf_t *conf, int num) 350 { 351 kmem_cache_t *sc; 352 int devs = conf->raid_disks; 353 354 sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev)); 355 sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev)); 356 conf->active_name = 0; 357 sc = kmem_cache_create(conf->cache_name[conf->active_name], 358 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 359 0, 0, NULL, NULL); 360 if (!sc) 361 return 1; 362 conf->slab_cache = sc; 363 conf->pool_size = devs; 364 while (num--) 365 if (!grow_one_stripe(conf)) 366 return 1; 367 return 0; 368 } 369 370 #ifdef CONFIG_MD_RAID5_RESHAPE 371 static int resize_stripes(raid5_conf_t *conf, int newsize) 372 { 373 /* Make all the stripes able to hold 'newsize' devices. 374 * New slots in each stripe get 'page' set to a new page. 375 * 376 * This happens in stages: 377 * 1/ create a new kmem_cache and allocate the required number of 378 * stripe_heads. 379 * 2/ gather all the old stripe_heads and tranfer the pages across 380 * to the new stripe_heads. This will have the side effect of 381 * freezing the array as once all stripe_heads have been collected, 382 * no IO will be possible. Old stripe heads are freed once their 383 * pages have been transferred over, and the old kmem_cache is 384 * freed when all stripes are done. 385 * 3/ reallocate conf->disks to be suitable bigger. If this fails, 386 * we simple return a failre status - no need to clean anything up. 387 * 4/ allocate new pages for the new slots in the new stripe_heads. 388 * If this fails, we don't bother trying the shrink the 389 * stripe_heads down again, we just leave them as they are. 390 * As each stripe_head is processed the new one is released into 391 * active service. 392 * 393 * Once step2 is started, we cannot afford to wait for a write, 394 * so we use GFP_NOIO allocations. 395 */ 396 struct stripe_head *osh, *nsh; 397 LIST_HEAD(newstripes); 398 struct disk_info *ndisks; 399 int err = 0; 400 kmem_cache_t *sc; 401 int i; 402 403 if (newsize <= conf->pool_size) 404 return 0; /* never bother to shrink */ 405 406 /* Step 1 */ 407 sc = kmem_cache_create(conf->cache_name[1-conf->active_name], 408 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), 409 0, 0, NULL, NULL); 410 if (!sc) 411 return -ENOMEM; 412 413 for (i = conf->max_nr_stripes; i; i--) { 414 nsh = kmem_cache_alloc(sc, GFP_KERNEL); 415 if (!nsh) 416 break; 417 418 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev)); 419 420 nsh->raid_conf = conf; 421 spin_lock_init(&nsh->lock); 422 423 list_add(&nsh->lru, &newstripes); 424 } 425 if (i) { 426 /* didn't get enough, give up */ 427 while (!list_empty(&newstripes)) { 428 nsh = list_entry(newstripes.next, struct stripe_head, lru); 429 list_del(&nsh->lru); 430 kmem_cache_free(sc, nsh); 431 } 432 kmem_cache_destroy(sc); 433 return -ENOMEM; 434 } 435 /* Step 2 - Must use GFP_NOIO now. 436 * OK, we have enough stripes, start collecting inactive 437 * stripes and copying them over 438 */ 439 list_for_each_entry(nsh, &newstripes, lru) { 440 spin_lock_irq(&conf->device_lock); 441 wait_event_lock_irq(conf->wait_for_stripe, 442 !list_empty(&conf->inactive_list), 443 conf->device_lock, 444 unplug_slaves(conf->mddev) 445 ); 446 osh = get_free_stripe(conf); 447 spin_unlock_irq(&conf->device_lock); 448 atomic_set(&nsh->count, 1); 449 for(i=0; i<conf->pool_size; i++) 450 nsh->dev[i].page = osh->dev[i].page; 451 for( ; i<newsize; i++) 452 nsh->dev[i].page = NULL; 453 kmem_cache_free(conf->slab_cache, osh); 454 } 455 kmem_cache_destroy(conf->slab_cache); 456 457 /* Step 3. 458 * At this point, we are holding all the stripes so the array 459 * is completely stalled, so now is a good time to resize 460 * conf->disks. 461 */ 462 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); 463 if (ndisks) { 464 for (i=0; i<conf->raid_disks; i++) 465 ndisks[i] = conf->disks[i]; 466 kfree(conf->disks); 467 conf->disks = ndisks; 468 } else 469 err = -ENOMEM; 470 471 /* Step 4, return new stripes to service */ 472 while(!list_empty(&newstripes)) { 473 nsh = list_entry(newstripes.next, struct stripe_head, lru); 474 list_del_init(&nsh->lru); 475 for (i=conf->raid_disks; i < newsize; i++) 476 if (nsh->dev[i].page == NULL) { 477 struct page *p = alloc_page(GFP_NOIO); 478 nsh->dev[i].page = p; 479 if (!p) 480 err = -ENOMEM; 481 } 482 release_stripe(nsh); 483 } 484 /* critical section pass, GFP_NOIO no longer needed */ 485 486 conf->slab_cache = sc; 487 conf->active_name = 1-conf->active_name; 488 conf->pool_size = newsize; 489 return err; 490 } 491 #endif 492 493 static int drop_one_stripe(raid5_conf_t *conf) 494 { 495 struct stripe_head *sh; 496 497 spin_lock_irq(&conf->device_lock); 498 sh = get_free_stripe(conf); 499 spin_unlock_irq(&conf->device_lock); 500 if (!sh) 501 return 0; 502 BUG_ON(atomic_read(&sh->count)); 503 shrink_buffers(sh, conf->pool_size); 504 kmem_cache_free(conf->slab_cache, sh); 505 atomic_dec(&conf->active_stripes); 506 return 1; 507 } 508 509 static void shrink_stripes(raid5_conf_t *conf) 510 { 511 while (drop_one_stripe(conf)) 512 ; 513 514 if (conf->slab_cache) 515 kmem_cache_destroy(conf->slab_cache); 516 conf->slab_cache = NULL; 517 } 518 519 static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done, 520 int error) 521 { 522 struct stripe_head *sh = bi->bi_private; 523 raid5_conf_t *conf = sh->raid_conf; 524 int disks = sh->disks, i; 525 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 526 char b[BDEVNAME_SIZE]; 527 mdk_rdev_t *rdev; 528 529 if (bi->bi_size) 530 return 1; 531 532 for (i=0 ; i<disks; i++) 533 if (bi == &sh->dev[i].req) 534 break; 535 536 PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n", 537 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 538 uptodate); 539 if (i == disks) { 540 BUG(); 541 return 0; 542 } 543 544 if (uptodate) { 545 #if 0 546 struct bio *bio; 547 unsigned long flags; 548 spin_lock_irqsave(&conf->device_lock, flags); 549 /* we can return a buffer if we bypassed the cache or 550 * if the top buffer is not in highmem. If there are 551 * multiple buffers, leave the extra work to 552 * handle_stripe 553 */ 554 buffer = sh->bh_read[i]; 555 if (buffer && 556 (!PageHighMem(buffer->b_page) 557 || buffer->b_page == bh->b_page ) 558 ) { 559 sh->bh_read[i] = buffer->b_reqnext; 560 buffer->b_reqnext = NULL; 561 } else 562 buffer = NULL; 563 spin_unlock_irqrestore(&conf->device_lock, flags); 564 if (sh->bh_page[i]==bh->b_page) 565 set_buffer_uptodate(bh); 566 if (buffer) { 567 if (buffer->b_page != bh->b_page) 568 memcpy(buffer->b_data, bh->b_data, bh->b_size); 569 buffer->b_end_io(buffer, 1); 570 } 571 #else 572 set_bit(R5_UPTODATE, &sh->dev[i].flags); 573 #endif 574 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 575 rdev = conf->disks[i].rdev; 576 printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n", 577 mdname(conf->mddev), STRIPE_SECTORS, 578 (unsigned long long)sh->sector + rdev->data_offset, 579 bdevname(rdev->bdev, b)); 580 clear_bit(R5_ReadError, &sh->dev[i].flags); 581 clear_bit(R5_ReWrite, &sh->dev[i].flags); 582 } 583 if (atomic_read(&conf->disks[i].rdev->read_errors)) 584 atomic_set(&conf->disks[i].rdev->read_errors, 0); 585 } else { 586 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); 587 int retry = 0; 588 rdev = conf->disks[i].rdev; 589 590 clear_bit(R5_UPTODATE, &sh->dev[i].flags); 591 atomic_inc(&rdev->read_errors); 592 if (conf->mddev->degraded) 593 printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n", 594 mdname(conf->mddev), 595 (unsigned long long)sh->sector + rdev->data_offset, 596 bdn); 597 else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) 598 /* Oh, no!!! */ 599 printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n", 600 mdname(conf->mddev), 601 (unsigned long long)sh->sector + rdev->data_offset, 602 bdn); 603 else if (atomic_read(&rdev->read_errors) 604 > conf->max_nr_stripes) 605 printk(KERN_WARNING 606 "raid5:%s: Too many read errors, failing device %s.\n", 607 mdname(conf->mddev), bdn); 608 else 609 retry = 1; 610 if (retry) 611 set_bit(R5_ReadError, &sh->dev[i].flags); 612 else { 613 clear_bit(R5_ReadError, &sh->dev[i].flags); 614 clear_bit(R5_ReWrite, &sh->dev[i].flags); 615 md_error(conf->mddev, rdev); 616 } 617 } 618 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 619 #if 0 620 /* must restore b_page before unlocking buffer... */ 621 if (sh->bh_page[i] != bh->b_page) { 622 bh->b_page = sh->bh_page[i]; 623 bh->b_data = page_address(bh->b_page); 624 clear_buffer_uptodate(bh); 625 } 626 #endif 627 clear_bit(R5_LOCKED, &sh->dev[i].flags); 628 set_bit(STRIPE_HANDLE, &sh->state); 629 release_stripe(sh); 630 return 0; 631 } 632 633 static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done, 634 int error) 635 { 636 struct stripe_head *sh = bi->bi_private; 637 raid5_conf_t *conf = sh->raid_conf; 638 int disks = sh->disks, i; 639 unsigned long flags; 640 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 641 642 if (bi->bi_size) 643 return 1; 644 645 for (i=0 ; i<disks; i++) 646 if (bi == &sh->dev[i].req) 647 break; 648 649 PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", 650 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 651 uptodate); 652 if (i == disks) { 653 BUG(); 654 return 0; 655 } 656 657 spin_lock_irqsave(&conf->device_lock, flags); 658 if (!uptodate) 659 md_error(conf->mddev, conf->disks[i].rdev); 660 661 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 662 663 clear_bit(R5_LOCKED, &sh->dev[i].flags); 664 set_bit(STRIPE_HANDLE, &sh->state); 665 __release_stripe(conf, sh); 666 spin_unlock_irqrestore(&conf->device_lock, flags); 667 return 0; 668 } 669 670 671 static sector_t compute_blocknr(struct stripe_head *sh, int i); 672 673 static void raid5_build_block (struct stripe_head *sh, int i) 674 { 675 struct r5dev *dev = &sh->dev[i]; 676 677 bio_init(&dev->req); 678 dev->req.bi_io_vec = &dev->vec; 679 dev->req.bi_vcnt++; 680 dev->req.bi_max_vecs++; 681 dev->vec.bv_page = dev->page; 682 dev->vec.bv_len = STRIPE_SIZE; 683 dev->vec.bv_offset = 0; 684 685 dev->req.bi_sector = sh->sector; 686 dev->req.bi_private = sh; 687 688 dev->flags = 0; 689 dev->sector = compute_blocknr(sh, i); 690 } 691 692 static void error(mddev_t *mddev, mdk_rdev_t *rdev) 693 { 694 char b[BDEVNAME_SIZE]; 695 raid5_conf_t *conf = (raid5_conf_t *) mddev->private; 696 PRINTK("raid5: error called\n"); 697 698 if (!test_bit(Faulty, &rdev->flags)) { 699 mddev->sb_dirty = 1; 700 if (test_bit(In_sync, &rdev->flags)) { 701 conf->working_disks--; 702 mddev->degraded++; 703 conf->failed_disks++; 704 clear_bit(In_sync, &rdev->flags); 705 /* 706 * if recovery was running, make sure it aborts. 707 */ 708 set_bit(MD_RECOVERY_ERR, &mddev->recovery); 709 } 710 set_bit(Faulty, &rdev->flags); 711 printk (KERN_ALERT 712 "raid5: Disk failure on %s, disabling device." 713 " Operation continuing on %d devices\n", 714 bdevname(rdev->bdev,b), conf->working_disks); 715 } 716 } 717 718 /* 719 * Input: a 'big' sector number, 720 * Output: index of the data and parity disk, and the sector # in them. 721 */ 722 static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks, 723 unsigned int data_disks, unsigned int * dd_idx, 724 unsigned int * pd_idx, raid5_conf_t *conf) 725 { 726 long stripe; 727 unsigned long chunk_number; 728 unsigned int chunk_offset; 729 sector_t new_sector; 730 int sectors_per_chunk = conf->chunk_size >> 9; 731 732 /* First compute the information on this sector */ 733 734 /* 735 * Compute the chunk number and the sector offset inside the chunk 736 */ 737 chunk_offset = sector_div(r_sector, sectors_per_chunk); 738 chunk_number = r_sector; 739 BUG_ON(r_sector != chunk_number); 740 741 /* 742 * Compute the stripe number 743 */ 744 stripe = chunk_number / data_disks; 745 746 /* 747 * Compute the data disk and parity disk indexes inside the stripe 748 */ 749 *dd_idx = chunk_number % data_disks; 750 751 /* 752 * Select the parity disk based on the user selected algorithm. 753 */ 754 switch(conf->level) { 755 case 4: 756 *pd_idx = data_disks; 757 break; 758 case 5: 759 switch (conf->algorithm) { 760 case ALGORITHM_LEFT_ASYMMETRIC: 761 *pd_idx = data_disks - stripe % raid_disks; 762 if (*dd_idx >= *pd_idx) 763 (*dd_idx)++; 764 break; 765 case ALGORITHM_RIGHT_ASYMMETRIC: 766 *pd_idx = stripe % raid_disks; 767 if (*dd_idx >= *pd_idx) 768 (*dd_idx)++; 769 break; 770 case ALGORITHM_LEFT_SYMMETRIC: 771 *pd_idx = data_disks - stripe % raid_disks; 772 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; 773 break; 774 case ALGORITHM_RIGHT_SYMMETRIC: 775 *pd_idx = stripe % raid_disks; 776 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; 777 break; 778 default: 779 printk(KERN_ERR "raid5: unsupported algorithm %d\n", 780 conf->algorithm); 781 } 782 break; 783 case 6: 784 785 /**** FIX THIS ****/ 786 switch (conf->algorithm) { 787 case ALGORITHM_LEFT_ASYMMETRIC: 788 *pd_idx = raid_disks - 1 - (stripe % raid_disks); 789 if (*pd_idx == raid_disks-1) 790 (*dd_idx)++; /* Q D D D P */ 791 else if (*dd_idx >= *pd_idx) 792 (*dd_idx) += 2; /* D D P Q D */ 793 break; 794 case ALGORITHM_RIGHT_ASYMMETRIC: 795 *pd_idx = stripe % raid_disks; 796 if (*pd_idx == raid_disks-1) 797 (*dd_idx)++; /* Q D D D P */ 798 else if (*dd_idx >= *pd_idx) 799 (*dd_idx) += 2; /* D D P Q D */ 800 break; 801 case ALGORITHM_LEFT_SYMMETRIC: 802 *pd_idx = raid_disks - 1 - (stripe % raid_disks); 803 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; 804 break; 805 case ALGORITHM_RIGHT_SYMMETRIC: 806 *pd_idx = stripe % raid_disks; 807 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; 808 break; 809 default: 810 printk (KERN_CRIT "raid6: unsupported algorithm %d\n", 811 conf->algorithm); 812 } 813 break; 814 } 815 816 /* 817 * Finally, compute the new sector number 818 */ 819 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; 820 return new_sector; 821 } 822 823 824 static sector_t compute_blocknr(struct stripe_head *sh, int i) 825 { 826 raid5_conf_t *conf = sh->raid_conf; 827 int raid_disks = sh->disks, data_disks = raid_disks - 1; 828 sector_t new_sector = sh->sector, check; 829 int sectors_per_chunk = conf->chunk_size >> 9; 830 sector_t stripe; 831 int chunk_offset; 832 int chunk_number, dummy1, dummy2, dd_idx = i; 833 sector_t r_sector; 834 835 836 chunk_offset = sector_div(new_sector, sectors_per_chunk); 837 stripe = new_sector; 838 BUG_ON(new_sector != stripe); 839 840 if (i == sh->pd_idx) 841 return 0; 842 switch(conf->level) { 843 case 4: break; 844 case 5: 845 switch (conf->algorithm) { 846 case ALGORITHM_LEFT_ASYMMETRIC: 847 case ALGORITHM_RIGHT_ASYMMETRIC: 848 if (i > sh->pd_idx) 849 i--; 850 break; 851 case ALGORITHM_LEFT_SYMMETRIC: 852 case ALGORITHM_RIGHT_SYMMETRIC: 853 if (i < sh->pd_idx) 854 i += raid_disks; 855 i -= (sh->pd_idx + 1); 856 break; 857 default: 858 printk(KERN_ERR "raid5: unsupported algorithm %d\n", 859 conf->algorithm); 860 } 861 break; 862 case 6: 863 data_disks = raid_disks - 2; 864 if (i == raid6_next_disk(sh->pd_idx, raid_disks)) 865 return 0; /* It is the Q disk */ 866 switch (conf->algorithm) { 867 case ALGORITHM_LEFT_ASYMMETRIC: 868 case ALGORITHM_RIGHT_ASYMMETRIC: 869 if (sh->pd_idx == raid_disks-1) 870 i--; /* Q D D D P */ 871 else if (i > sh->pd_idx) 872 i -= 2; /* D D P Q D */ 873 break; 874 case ALGORITHM_LEFT_SYMMETRIC: 875 case ALGORITHM_RIGHT_SYMMETRIC: 876 if (sh->pd_idx == raid_disks-1) 877 i--; /* Q D D D P */ 878 else { 879 /* D D P Q D */ 880 if (i < sh->pd_idx) 881 i += raid_disks; 882 i -= (sh->pd_idx + 2); 883 } 884 break; 885 default: 886 printk (KERN_CRIT "raid6: unsupported algorithm %d\n", 887 conf->algorithm); 888 } 889 break; 890 } 891 892 chunk_number = stripe * data_disks + i; 893 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset; 894 895 check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf); 896 if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { 897 printk(KERN_ERR "compute_blocknr: map not correct\n"); 898 return 0; 899 } 900 return r_sector; 901 } 902 903 904 905 /* 906 * Copy data between a page in the stripe cache, and one or more bion 907 * The page could align with the middle of the bio, or there could be 908 * several bion, each with several bio_vecs, which cover part of the page 909 * Multiple bion are linked together on bi_next. There may be extras 910 * at the end of this list. We ignore them. 911 */ 912 static void copy_data(int frombio, struct bio *bio, 913 struct page *page, 914 sector_t sector) 915 { 916 char *pa = page_address(page); 917 struct bio_vec *bvl; 918 int i; 919 int page_offset; 920 921 if (bio->bi_sector >= sector) 922 page_offset = (signed)(bio->bi_sector - sector) * 512; 923 else 924 page_offset = (signed)(sector - bio->bi_sector) * -512; 925 bio_for_each_segment(bvl, bio, i) { 926 int len = bio_iovec_idx(bio,i)->bv_len; 927 int clen; 928 int b_offset = 0; 929 930 if (page_offset < 0) { 931 b_offset = -page_offset; 932 page_offset += b_offset; 933 len -= b_offset; 934 } 935 936 if (len > 0 && page_offset + len > STRIPE_SIZE) 937 clen = STRIPE_SIZE - page_offset; 938 else clen = len; 939 940 if (clen > 0) { 941 char *ba = __bio_kmap_atomic(bio, i, KM_USER0); 942 if (frombio) 943 memcpy(pa+page_offset, ba+b_offset, clen); 944 else 945 memcpy(ba+b_offset, pa+page_offset, clen); 946 __bio_kunmap_atomic(ba, KM_USER0); 947 } 948 if (clen < len) /* hit end of page */ 949 break; 950 page_offset += len; 951 } 952 } 953 954 #define check_xor() do { \ 955 if (count == MAX_XOR_BLOCKS) { \ 956 xor_block(count, STRIPE_SIZE, ptr); \ 957 count = 1; \ 958 } \ 959 } while(0) 960 961 962 static void compute_block(struct stripe_head *sh, int dd_idx) 963 { 964 int i, count, disks = sh->disks; 965 void *ptr[MAX_XOR_BLOCKS], *p; 966 967 PRINTK("compute_block, stripe %llu, idx %d\n", 968 (unsigned long long)sh->sector, dd_idx); 969 970 ptr[0] = page_address(sh->dev[dd_idx].page); 971 memset(ptr[0], 0, STRIPE_SIZE); 972 count = 1; 973 for (i = disks ; i--; ) { 974 if (i == dd_idx) 975 continue; 976 p = page_address(sh->dev[i].page); 977 if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) 978 ptr[count++] = p; 979 else 980 printk(KERN_ERR "compute_block() %d, stripe %llu, %d" 981 " not present\n", dd_idx, 982 (unsigned long long)sh->sector, i); 983 984 check_xor(); 985 } 986 if (count != 1) 987 xor_block(count, STRIPE_SIZE, ptr); 988 set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); 989 } 990 991 static void compute_parity5(struct stripe_head *sh, int method) 992 { 993 raid5_conf_t *conf = sh->raid_conf; 994 int i, pd_idx = sh->pd_idx, disks = sh->disks, count; 995 void *ptr[MAX_XOR_BLOCKS]; 996 struct bio *chosen; 997 998 PRINTK("compute_parity5, stripe %llu, method %d\n", 999 (unsigned long long)sh->sector, method); 1000 1001 count = 1; 1002 ptr[0] = page_address(sh->dev[pd_idx].page); 1003 switch(method) { 1004 case READ_MODIFY_WRITE: 1005 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags)); 1006 for (i=disks ; i-- ;) { 1007 if (i==pd_idx) 1008 continue; 1009 if (sh->dev[i].towrite && 1010 test_bit(R5_UPTODATE, &sh->dev[i].flags)) { 1011 ptr[count++] = page_address(sh->dev[i].page); 1012 chosen = sh->dev[i].towrite; 1013 sh->dev[i].towrite = NULL; 1014 1015 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 1016 wake_up(&conf->wait_for_overlap); 1017 1018 BUG_ON(sh->dev[i].written); 1019 sh->dev[i].written = chosen; 1020 check_xor(); 1021 } 1022 } 1023 break; 1024 case RECONSTRUCT_WRITE: 1025 memset(ptr[0], 0, STRIPE_SIZE); 1026 for (i= disks; i-- ;) 1027 if (i!=pd_idx && sh->dev[i].towrite) { 1028 chosen = sh->dev[i].towrite; 1029 sh->dev[i].towrite = NULL; 1030 1031 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 1032 wake_up(&conf->wait_for_overlap); 1033 1034 BUG_ON(sh->dev[i].written); 1035 sh->dev[i].written = chosen; 1036 } 1037 break; 1038 case CHECK_PARITY: 1039 break; 1040 } 1041 if (count>1) { 1042 xor_block(count, STRIPE_SIZE, ptr); 1043 count = 1; 1044 } 1045 1046 for (i = disks; i--;) 1047 if (sh->dev[i].written) { 1048 sector_t sector = sh->dev[i].sector; 1049 struct bio *wbi = sh->dev[i].written; 1050 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { 1051 copy_data(1, wbi, sh->dev[i].page, sector); 1052 wbi = r5_next_bio(wbi, sector); 1053 } 1054 1055 set_bit(R5_LOCKED, &sh->dev[i].flags); 1056 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1057 } 1058 1059 switch(method) { 1060 case RECONSTRUCT_WRITE: 1061 case CHECK_PARITY: 1062 for (i=disks; i--;) 1063 if (i != pd_idx) { 1064 ptr[count++] = page_address(sh->dev[i].page); 1065 check_xor(); 1066 } 1067 break; 1068 case READ_MODIFY_WRITE: 1069 for (i = disks; i--;) 1070 if (sh->dev[i].written) { 1071 ptr[count++] = page_address(sh->dev[i].page); 1072 check_xor(); 1073 } 1074 } 1075 if (count != 1) 1076 xor_block(count, STRIPE_SIZE, ptr); 1077 1078 if (method != CHECK_PARITY) { 1079 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 1080 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 1081 } else 1082 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 1083 } 1084 1085 static void compute_parity6(struct stripe_head *sh, int method) 1086 { 1087 raid6_conf_t *conf = sh->raid_conf; 1088 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count; 1089 struct bio *chosen; 1090 /**** FIX THIS: This could be very bad if disks is close to 256 ****/ 1091 void *ptrs[disks]; 1092 1093 qd_idx = raid6_next_disk(pd_idx, disks); 1094 d0_idx = raid6_next_disk(qd_idx, disks); 1095 1096 PRINTK("compute_parity, stripe %llu, method %d\n", 1097 (unsigned long long)sh->sector, method); 1098 1099 switch(method) { 1100 case READ_MODIFY_WRITE: 1101 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */ 1102 case RECONSTRUCT_WRITE: 1103 for (i= disks; i-- ;) 1104 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) { 1105 chosen = sh->dev[i].towrite; 1106 sh->dev[i].towrite = NULL; 1107 1108 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 1109 wake_up(&conf->wait_for_overlap); 1110 1111 if (sh->dev[i].written) BUG(); 1112 sh->dev[i].written = chosen; 1113 } 1114 break; 1115 case CHECK_PARITY: 1116 BUG(); /* Not implemented yet */ 1117 } 1118 1119 for (i = disks; i--;) 1120 if (sh->dev[i].written) { 1121 sector_t sector = sh->dev[i].sector; 1122 struct bio *wbi = sh->dev[i].written; 1123 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) { 1124 copy_data(1, wbi, sh->dev[i].page, sector); 1125 wbi = r5_next_bio(wbi, sector); 1126 } 1127 1128 set_bit(R5_LOCKED, &sh->dev[i].flags); 1129 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1130 } 1131 1132 // switch(method) { 1133 // case RECONSTRUCT_WRITE: 1134 // case CHECK_PARITY: 1135 // case UPDATE_PARITY: 1136 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */ 1137 /* FIX: Is this ordering of drives even remotely optimal? */ 1138 count = 0; 1139 i = d0_idx; 1140 do { 1141 ptrs[count++] = page_address(sh->dev[i].page); 1142 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags)) 1143 printk("block %d/%d not uptodate on parity calc\n", i,count); 1144 i = raid6_next_disk(i, disks); 1145 } while ( i != d0_idx ); 1146 // break; 1147 // } 1148 1149 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs); 1150 1151 switch(method) { 1152 case RECONSTRUCT_WRITE: 1153 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 1154 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); 1155 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 1156 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags); 1157 break; 1158 case UPDATE_PARITY: 1159 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 1160 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags); 1161 break; 1162 } 1163 } 1164 1165 1166 /* Compute one missing block */ 1167 static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero) 1168 { 1169 raid6_conf_t *conf = sh->raid_conf; 1170 int i, count, disks = conf->raid_disks; 1171 void *ptr[MAX_XOR_BLOCKS], *p; 1172 int pd_idx = sh->pd_idx; 1173 int qd_idx = raid6_next_disk(pd_idx, disks); 1174 1175 PRINTK("compute_block_1, stripe %llu, idx %d\n", 1176 (unsigned long long)sh->sector, dd_idx); 1177 1178 if ( dd_idx == qd_idx ) { 1179 /* We're actually computing the Q drive */ 1180 compute_parity6(sh, UPDATE_PARITY); 1181 } else { 1182 ptr[0] = page_address(sh->dev[dd_idx].page); 1183 if (!nozero) memset(ptr[0], 0, STRIPE_SIZE); 1184 count = 1; 1185 for (i = disks ; i--; ) { 1186 if (i == dd_idx || i == qd_idx) 1187 continue; 1188 p = page_address(sh->dev[i].page); 1189 if (test_bit(R5_UPTODATE, &sh->dev[i].flags)) 1190 ptr[count++] = p; 1191 else 1192 printk("compute_block() %d, stripe %llu, %d" 1193 " not present\n", dd_idx, 1194 (unsigned long long)sh->sector, i); 1195 1196 check_xor(); 1197 } 1198 if (count != 1) 1199 xor_block(count, STRIPE_SIZE, ptr); 1200 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); 1201 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); 1202 } 1203 } 1204 1205 /* Compute two missing blocks */ 1206 static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) 1207 { 1208 raid6_conf_t *conf = sh->raid_conf; 1209 int i, count, disks = conf->raid_disks; 1210 int pd_idx = sh->pd_idx; 1211 int qd_idx = raid6_next_disk(pd_idx, disks); 1212 int d0_idx = raid6_next_disk(qd_idx, disks); 1213 int faila, failb; 1214 1215 /* faila and failb are disk numbers relative to d0_idx */ 1216 /* pd_idx become disks-2 and qd_idx become disks-1 */ 1217 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx; 1218 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx; 1219 1220 BUG_ON(faila == failb); 1221 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; } 1222 1223 PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n", 1224 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb); 1225 1226 if ( failb == disks-1 ) { 1227 /* Q disk is one of the missing disks */ 1228 if ( faila == disks-2 ) { 1229 /* Missing P+Q, just recompute */ 1230 compute_parity6(sh, UPDATE_PARITY); 1231 return; 1232 } else { 1233 /* We're missing D+Q; recompute D from P */ 1234 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0); 1235 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */ 1236 return; 1237 } 1238 } 1239 1240 /* We're missing D+P or D+D; build pointer table */ 1241 { 1242 /**** FIX THIS: This could be very bad if disks is close to 256 ****/ 1243 void *ptrs[disks]; 1244 1245 count = 0; 1246 i = d0_idx; 1247 do { 1248 ptrs[count++] = page_address(sh->dev[i].page); 1249 i = raid6_next_disk(i, disks); 1250 if (i != dd_idx1 && i != dd_idx2 && 1251 !test_bit(R5_UPTODATE, &sh->dev[i].flags)) 1252 printk("compute_2 with missing block %d/%d\n", count, i); 1253 } while ( i != d0_idx ); 1254 1255 if ( failb == disks-2 ) { 1256 /* We're missing D+P. */ 1257 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs); 1258 } else { 1259 /* We're missing D+D. */ 1260 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs); 1261 } 1262 1263 /* Both the above update both missing blocks */ 1264 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags); 1265 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags); 1266 } 1267 } 1268 1269 1270 1271 /* 1272 * Each stripe/dev can have one or more bion attached. 1273 * toread/towrite point to the first in a chain. 1274 * The bi_next chain must be in order. 1275 */ 1276 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 1277 { 1278 struct bio **bip; 1279 raid5_conf_t *conf = sh->raid_conf; 1280 int firstwrite=0; 1281 1282 PRINTK("adding bh b#%llu to stripe s#%llu\n", 1283 (unsigned long long)bi->bi_sector, 1284 (unsigned long long)sh->sector); 1285 1286 1287 spin_lock(&sh->lock); 1288 spin_lock_irq(&conf->device_lock); 1289 if (forwrite) { 1290 bip = &sh->dev[dd_idx].towrite; 1291 if (*bip == NULL && sh->dev[dd_idx].written == NULL) 1292 firstwrite = 1; 1293 } else 1294 bip = &sh->dev[dd_idx].toread; 1295 while (*bip && (*bip)->bi_sector < bi->bi_sector) { 1296 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) 1297 goto overlap; 1298 bip = & (*bip)->bi_next; 1299 } 1300 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) 1301 goto overlap; 1302 1303 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); 1304 if (*bip) 1305 bi->bi_next = *bip; 1306 *bip = bi; 1307 bi->bi_phys_segments ++; 1308 spin_unlock_irq(&conf->device_lock); 1309 spin_unlock(&sh->lock); 1310 1311 PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n", 1312 (unsigned long long)bi->bi_sector, 1313 (unsigned long long)sh->sector, dd_idx); 1314 1315 if (conf->mddev->bitmap && firstwrite) { 1316 bitmap_startwrite(conf->mddev->bitmap, sh->sector, 1317 STRIPE_SECTORS, 0); 1318 sh->bm_seq = conf->seq_flush+1; 1319 set_bit(STRIPE_BIT_DELAY, &sh->state); 1320 } 1321 1322 if (forwrite) { 1323 /* check if page is covered */ 1324 sector_t sector = sh->dev[dd_idx].sector; 1325 for (bi=sh->dev[dd_idx].towrite; 1326 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && 1327 bi && bi->bi_sector <= sector; 1328 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { 1329 if (bi->bi_sector + (bi->bi_size>>9) >= sector) 1330 sector = bi->bi_sector + (bi->bi_size>>9); 1331 } 1332 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) 1333 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); 1334 } 1335 return 1; 1336 1337 overlap: 1338 set_bit(R5_Overlap, &sh->dev[dd_idx].flags); 1339 spin_unlock_irq(&conf->device_lock); 1340 spin_unlock(&sh->lock); 1341 return 0; 1342 } 1343 1344 static void end_reshape(raid5_conf_t *conf); 1345 1346 static int page_is_zero(struct page *p) 1347 { 1348 char *a = page_address(p); 1349 return ((*(u32*)a) == 0 && 1350 memcmp(a, a+4, STRIPE_SIZE-4)==0); 1351 } 1352 1353 static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) 1354 { 1355 int sectors_per_chunk = conf->chunk_size >> 9; 1356 sector_t x = stripe; 1357 int pd_idx, dd_idx; 1358 int chunk_offset = sector_div(x, sectors_per_chunk); 1359 stripe = x; 1360 raid5_compute_sector(stripe*(disks-1)*sectors_per_chunk 1361 + chunk_offset, disks, disks-1, &dd_idx, &pd_idx, conf); 1362 return pd_idx; 1363 } 1364 1365 1366 /* 1367 * handle_stripe - do things to a stripe. 1368 * 1369 * We lock the stripe and then examine the state of various bits 1370 * to see what needs to be done. 1371 * Possible results: 1372 * return some read request which now have data 1373 * return some write requests which are safely on disc 1374 * schedule a read on some buffers 1375 * schedule a write of some buffers 1376 * return confirmation of parity correctness 1377 * 1378 * Parity calculations are done inside the stripe lock 1379 * buffers are taken off read_list or write_list, and bh_cache buffers 1380 * get BH_Lock set before the stripe lock is released. 1381 * 1382 */ 1383 1384 static void handle_stripe5(struct stripe_head *sh) 1385 { 1386 raid5_conf_t *conf = sh->raid_conf; 1387 int disks = sh->disks; 1388 struct bio *return_bi= NULL; 1389 struct bio *bi; 1390 int i; 1391 int syncing, expanding, expanded; 1392 int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; 1393 int non_overwrite = 0; 1394 int failed_num=0; 1395 struct r5dev *dev; 1396 1397 PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n", 1398 (unsigned long long)sh->sector, atomic_read(&sh->count), 1399 sh->pd_idx); 1400 1401 spin_lock(&sh->lock); 1402 clear_bit(STRIPE_HANDLE, &sh->state); 1403 clear_bit(STRIPE_DELAYED, &sh->state); 1404 1405 syncing = test_bit(STRIPE_SYNCING, &sh->state); 1406 expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); 1407 expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); 1408 /* Now to look around and see what can be done */ 1409 1410 rcu_read_lock(); 1411 for (i=disks; i--; ) { 1412 mdk_rdev_t *rdev; 1413 dev = &sh->dev[i]; 1414 clear_bit(R5_Insync, &dev->flags); 1415 1416 PRINTK("check %d: state 0x%lx read %p write %p written %p\n", 1417 i, dev->flags, dev->toread, dev->towrite, dev->written); 1418 /* maybe we can reply to a read */ 1419 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { 1420 struct bio *rbi, *rbi2; 1421 PRINTK("Return read for disc %d\n", i); 1422 spin_lock_irq(&conf->device_lock); 1423 rbi = dev->toread; 1424 dev->toread = NULL; 1425 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1426 wake_up(&conf->wait_for_overlap); 1427 spin_unlock_irq(&conf->device_lock); 1428 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { 1429 copy_data(0, rbi, dev->page, dev->sector); 1430 rbi2 = r5_next_bio(rbi, dev->sector); 1431 spin_lock_irq(&conf->device_lock); 1432 if (--rbi->bi_phys_segments == 0) { 1433 rbi->bi_next = return_bi; 1434 return_bi = rbi; 1435 } 1436 spin_unlock_irq(&conf->device_lock); 1437 rbi = rbi2; 1438 } 1439 } 1440 1441 /* now count some things */ 1442 if (test_bit(R5_LOCKED, &dev->flags)) locked++; 1443 if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; 1444 1445 1446 if (dev->toread) to_read++; 1447 if (dev->towrite) { 1448 to_write++; 1449 if (!test_bit(R5_OVERWRITE, &dev->flags)) 1450 non_overwrite++; 1451 } 1452 if (dev->written) written++; 1453 rdev = rcu_dereference(conf->disks[i].rdev); 1454 if (!rdev || !test_bit(In_sync, &rdev->flags)) { 1455 /* The ReadError flag will just be confusing now */ 1456 clear_bit(R5_ReadError, &dev->flags); 1457 clear_bit(R5_ReWrite, &dev->flags); 1458 } 1459 if (!rdev || !test_bit(In_sync, &rdev->flags) 1460 || test_bit(R5_ReadError, &dev->flags)) { 1461 failed++; 1462 failed_num = i; 1463 } else 1464 set_bit(R5_Insync, &dev->flags); 1465 } 1466 rcu_read_unlock(); 1467 PRINTK("locked=%d uptodate=%d to_read=%d" 1468 " to_write=%d failed=%d failed_num=%d\n", 1469 locked, uptodate, to_read, to_write, failed, failed_num); 1470 /* check if the array has lost two devices and, if so, some requests might 1471 * need to be failed 1472 */ 1473 if (failed > 1 && to_read+to_write+written) { 1474 for (i=disks; i--; ) { 1475 int bitmap_end = 0; 1476 1477 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 1478 mdk_rdev_t *rdev; 1479 rcu_read_lock(); 1480 rdev = rcu_dereference(conf->disks[i].rdev); 1481 if (rdev && test_bit(In_sync, &rdev->flags)) 1482 /* multiple read failures in one stripe */ 1483 md_error(conf->mddev, rdev); 1484 rcu_read_unlock(); 1485 } 1486 1487 spin_lock_irq(&conf->device_lock); 1488 /* fail all writes first */ 1489 bi = sh->dev[i].towrite; 1490 sh->dev[i].towrite = NULL; 1491 if (bi) { to_write--; bitmap_end = 1; } 1492 1493 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 1494 wake_up(&conf->wait_for_overlap); 1495 1496 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ 1497 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 1498 clear_bit(BIO_UPTODATE, &bi->bi_flags); 1499 if (--bi->bi_phys_segments == 0) { 1500 md_write_end(conf->mddev); 1501 bi->bi_next = return_bi; 1502 return_bi = bi; 1503 } 1504 bi = nextbi; 1505 } 1506 /* and fail all 'written' */ 1507 bi = sh->dev[i].written; 1508 sh->dev[i].written = NULL; 1509 if (bi) bitmap_end = 1; 1510 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { 1511 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 1512 clear_bit(BIO_UPTODATE, &bi->bi_flags); 1513 if (--bi->bi_phys_segments == 0) { 1514 md_write_end(conf->mddev); 1515 bi->bi_next = return_bi; 1516 return_bi = bi; 1517 } 1518 bi = bi2; 1519 } 1520 1521 /* fail any reads if this device is non-operational */ 1522 if (!test_bit(R5_Insync, &sh->dev[i].flags) || 1523 test_bit(R5_ReadError, &sh->dev[i].flags)) { 1524 bi = sh->dev[i].toread; 1525 sh->dev[i].toread = NULL; 1526 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 1527 wake_up(&conf->wait_for_overlap); 1528 if (bi) to_read--; 1529 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ 1530 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 1531 clear_bit(BIO_UPTODATE, &bi->bi_flags); 1532 if (--bi->bi_phys_segments == 0) { 1533 bi->bi_next = return_bi; 1534 return_bi = bi; 1535 } 1536 bi = nextbi; 1537 } 1538 } 1539 spin_unlock_irq(&conf->device_lock); 1540 if (bitmap_end) 1541 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 1542 STRIPE_SECTORS, 0, 0); 1543 } 1544 } 1545 if (failed > 1 && syncing) { 1546 md_done_sync(conf->mddev, STRIPE_SECTORS,0); 1547 clear_bit(STRIPE_SYNCING, &sh->state); 1548 syncing = 0; 1549 } 1550 1551 /* might be able to return some write requests if the parity block 1552 * is safe, or on a failed drive 1553 */ 1554 dev = &sh->dev[sh->pd_idx]; 1555 if ( written && 1556 ( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) && 1557 test_bit(R5_UPTODATE, &dev->flags)) 1558 || (failed == 1 && failed_num == sh->pd_idx)) 1559 ) { 1560 /* any written block on an uptodate or failed drive can be returned. 1561 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 1562 * never LOCKED, so we don't need to test 'failed' directly. 1563 */ 1564 for (i=disks; i--; ) 1565 if (sh->dev[i].written) { 1566 dev = &sh->dev[i]; 1567 if (!test_bit(R5_LOCKED, &dev->flags) && 1568 test_bit(R5_UPTODATE, &dev->flags) ) { 1569 /* We can return any write requests */ 1570 struct bio *wbi, *wbi2; 1571 int bitmap_end = 0; 1572 PRINTK("Return write for disc %d\n", i); 1573 spin_lock_irq(&conf->device_lock); 1574 wbi = dev->written; 1575 dev->written = NULL; 1576 while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { 1577 wbi2 = r5_next_bio(wbi, dev->sector); 1578 if (--wbi->bi_phys_segments == 0) { 1579 md_write_end(conf->mddev); 1580 wbi->bi_next = return_bi; 1581 return_bi = wbi; 1582 } 1583 wbi = wbi2; 1584 } 1585 if (dev->towrite == NULL) 1586 bitmap_end = 1; 1587 spin_unlock_irq(&conf->device_lock); 1588 if (bitmap_end) 1589 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 1590 STRIPE_SECTORS, 1591 !test_bit(STRIPE_DEGRADED, &sh->state), 0); 1592 } 1593 } 1594 } 1595 1596 /* Now we might consider reading some blocks, either to check/generate 1597 * parity, or to satisfy requests 1598 * or to load a block that is being partially written. 1599 */ 1600 if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) { 1601 for (i=disks; i--;) { 1602 dev = &sh->dev[i]; 1603 if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && 1604 (dev->toread || 1605 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 1606 syncing || 1607 expanding || 1608 (failed && (sh->dev[failed_num].toread || 1609 (sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags)))) 1610 ) 1611 ) { 1612 /* we would like to get this block, possibly 1613 * by computing it, but we might not be able to 1614 */ 1615 if (uptodate == disks-1) { 1616 PRINTK("Computing block %d\n", i); 1617 compute_block(sh, i); 1618 uptodate++; 1619 } else if (test_bit(R5_Insync, &dev->flags)) { 1620 set_bit(R5_LOCKED, &dev->flags); 1621 set_bit(R5_Wantread, &dev->flags); 1622 #if 0 1623 /* if I am just reading this block and we don't have 1624 a failed drive, or any pending writes then sidestep the cache */ 1625 if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && 1626 ! syncing && !failed && !to_write) { 1627 sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; 1628 sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; 1629 } 1630 #endif 1631 locked++; 1632 PRINTK("Reading block %d (sync=%d)\n", 1633 i, syncing); 1634 } 1635 } 1636 } 1637 set_bit(STRIPE_HANDLE, &sh->state); 1638 } 1639 1640 /* now to consider writing and what else, if anything should be read */ 1641 if (to_write) { 1642 int rmw=0, rcw=0; 1643 for (i=disks ; i--;) { 1644 /* would I have to read this buffer for read_modify_write */ 1645 dev = &sh->dev[i]; 1646 if ((dev->towrite || i == sh->pd_idx) && 1647 (!test_bit(R5_LOCKED, &dev->flags) 1648 #if 0 1649 || sh->bh_page[i]!=bh->b_page 1650 #endif 1651 ) && 1652 !test_bit(R5_UPTODATE, &dev->flags)) { 1653 if (test_bit(R5_Insync, &dev->flags) 1654 /* && !(!mddev->insync && i == sh->pd_idx) */ 1655 ) 1656 rmw++; 1657 else rmw += 2*disks; /* cannot read it */ 1658 } 1659 /* Would I have to read this buffer for reconstruct_write */ 1660 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 1661 (!test_bit(R5_LOCKED, &dev->flags) 1662 #if 0 1663 || sh->bh_page[i] != bh->b_page 1664 #endif 1665 ) && 1666 !test_bit(R5_UPTODATE, &dev->flags)) { 1667 if (test_bit(R5_Insync, &dev->flags)) rcw++; 1668 else rcw += 2*disks; 1669 } 1670 } 1671 PRINTK("for sector %llu, rmw=%d rcw=%d\n", 1672 (unsigned long long)sh->sector, rmw, rcw); 1673 set_bit(STRIPE_HANDLE, &sh->state); 1674 if (rmw < rcw && rmw > 0) 1675 /* prefer read-modify-write, but need to get some data */ 1676 for (i=disks; i--;) { 1677 dev = &sh->dev[i]; 1678 if ((dev->towrite || i == sh->pd_idx) && 1679 !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && 1680 test_bit(R5_Insync, &dev->flags)) { 1681 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 1682 { 1683 PRINTK("Read_old block %d for r-m-w\n", i); 1684 set_bit(R5_LOCKED, &dev->flags); 1685 set_bit(R5_Wantread, &dev->flags); 1686 locked++; 1687 } else { 1688 set_bit(STRIPE_DELAYED, &sh->state); 1689 set_bit(STRIPE_HANDLE, &sh->state); 1690 } 1691 } 1692 } 1693 if (rcw <= rmw && rcw > 0) 1694 /* want reconstruct write, but need to get some data */ 1695 for (i=disks; i--;) { 1696 dev = &sh->dev[i]; 1697 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 1698 !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && 1699 test_bit(R5_Insync, &dev->flags)) { 1700 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 1701 { 1702 PRINTK("Read_old block %d for Reconstruct\n", i); 1703 set_bit(R5_LOCKED, &dev->flags); 1704 set_bit(R5_Wantread, &dev->flags); 1705 locked++; 1706 } else { 1707 set_bit(STRIPE_DELAYED, &sh->state); 1708 set_bit(STRIPE_HANDLE, &sh->state); 1709 } 1710 } 1711 } 1712 /* now if nothing is locked, and if we have enough data, we can start a write request */ 1713 if (locked == 0 && (rcw == 0 ||rmw == 0) && 1714 !test_bit(STRIPE_BIT_DELAY, &sh->state)) { 1715 PRINTK("Computing parity...\n"); 1716 compute_parity5(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); 1717 /* now every locked buffer is ready to be written */ 1718 for (i=disks; i--;) 1719 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { 1720 PRINTK("Writing block %d\n", i); 1721 locked++; 1722 set_bit(R5_Wantwrite, &sh->dev[i].flags); 1723 if (!test_bit(R5_Insync, &sh->dev[i].flags) 1724 || (i==sh->pd_idx && failed == 0)) 1725 set_bit(STRIPE_INSYNC, &sh->state); 1726 } 1727 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 1728 atomic_dec(&conf->preread_active_stripes); 1729 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 1730 md_wakeup_thread(conf->mddev->thread); 1731 } 1732 } 1733 } 1734 1735 /* maybe we need to check and possibly fix the parity for this stripe 1736 * Any reads will already have been scheduled, so we just see if enough data 1737 * is available 1738 */ 1739 if (syncing && locked == 0 && 1740 !test_bit(STRIPE_INSYNC, &sh->state)) { 1741 set_bit(STRIPE_HANDLE, &sh->state); 1742 if (failed == 0) { 1743 BUG_ON(uptodate != disks); 1744 compute_parity5(sh, CHECK_PARITY); 1745 uptodate--; 1746 if (page_is_zero(sh->dev[sh->pd_idx].page)) { 1747 /* parity is correct (on disc, not in buffer any more) */ 1748 set_bit(STRIPE_INSYNC, &sh->state); 1749 } else { 1750 conf->mddev->resync_mismatches += STRIPE_SECTORS; 1751 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 1752 /* don't try to repair!! */ 1753 set_bit(STRIPE_INSYNC, &sh->state); 1754 else { 1755 compute_block(sh, sh->pd_idx); 1756 uptodate++; 1757 } 1758 } 1759 } 1760 if (!test_bit(STRIPE_INSYNC, &sh->state)) { 1761 /* either failed parity check, or recovery is happening */ 1762 if (failed==0) 1763 failed_num = sh->pd_idx; 1764 dev = &sh->dev[failed_num]; 1765 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); 1766 BUG_ON(uptodate != disks); 1767 1768 set_bit(R5_LOCKED, &dev->flags); 1769 set_bit(R5_Wantwrite, &dev->flags); 1770 clear_bit(STRIPE_DEGRADED, &sh->state); 1771 locked++; 1772 set_bit(STRIPE_INSYNC, &sh->state); 1773 } 1774 } 1775 if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { 1776 md_done_sync(conf->mddev, STRIPE_SECTORS,1); 1777 clear_bit(STRIPE_SYNCING, &sh->state); 1778 } 1779 1780 /* If the failed drive is just a ReadError, then we might need to progress 1781 * the repair/check process 1782 */ 1783 if (failed == 1 && ! conf->mddev->ro && 1784 test_bit(R5_ReadError, &sh->dev[failed_num].flags) 1785 && !test_bit(R5_LOCKED, &sh->dev[failed_num].flags) 1786 && test_bit(R5_UPTODATE, &sh->dev[failed_num].flags) 1787 ) { 1788 dev = &sh->dev[failed_num]; 1789 if (!test_bit(R5_ReWrite, &dev->flags)) { 1790 set_bit(R5_Wantwrite, &dev->flags); 1791 set_bit(R5_ReWrite, &dev->flags); 1792 set_bit(R5_LOCKED, &dev->flags); 1793 locked++; 1794 } else { 1795 /* let's read it back */ 1796 set_bit(R5_Wantread, &dev->flags); 1797 set_bit(R5_LOCKED, &dev->flags); 1798 locked++; 1799 } 1800 } 1801 1802 if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { 1803 /* Need to write out all blocks after computing parity */ 1804 sh->disks = conf->raid_disks; 1805 sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); 1806 compute_parity5(sh, RECONSTRUCT_WRITE); 1807 for (i= conf->raid_disks; i--;) { 1808 set_bit(R5_LOCKED, &sh->dev[i].flags); 1809 locked++; 1810 set_bit(R5_Wantwrite, &sh->dev[i].flags); 1811 } 1812 clear_bit(STRIPE_EXPANDING, &sh->state); 1813 } else if (expanded) { 1814 clear_bit(STRIPE_EXPAND_READY, &sh->state); 1815 atomic_dec(&conf->reshape_stripes); 1816 wake_up(&conf->wait_for_overlap); 1817 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 1818 } 1819 1820 if (expanding && locked == 0) { 1821 /* We have read all the blocks in this stripe and now we need to 1822 * copy some of them into a target stripe for expand. 1823 */ 1824 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); 1825 for (i=0; i< sh->disks; i++) 1826 if (i != sh->pd_idx) { 1827 int dd_idx, pd_idx, j; 1828 struct stripe_head *sh2; 1829 1830 sector_t bn = compute_blocknr(sh, i); 1831 sector_t s = raid5_compute_sector(bn, conf->raid_disks, 1832 conf->raid_disks-1, 1833 &dd_idx, &pd_idx, conf); 1834 sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1); 1835 if (sh2 == NULL) 1836 /* so far only the early blocks of this stripe 1837 * have been requested. When later blocks 1838 * get requested, we will try again 1839 */ 1840 continue; 1841 if(!test_bit(STRIPE_EXPANDING, &sh2->state) || 1842 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { 1843 /* must have already done this block */ 1844 release_stripe(sh2); 1845 continue; 1846 } 1847 memcpy(page_address(sh2->dev[dd_idx].page), 1848 page_address(sh->dev[i].page), 1849 STRIPE_SIZE); 1850 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); 1851 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); 1852 for (j=0; j<conf->raid_disks; j++) 1853 if (j != sh2->pd_idx && 1854 !test_bit(R5_Expanded, &sh2->dev[j].flags)) 1855 break; 1856 if (j == conf->raid_disks) { 1857 set_bit(STRIPE_EXPAND_READY, &sh2->state); 1858 set_bit(STRIPE_HANDLE, &sh2->state); 1859 } 1860 release_stripe(sh2); 1861 } 1862 } 1863 1864 spin_unlock(&sh->lock); 1865 1866 while ((bi=return_bi)) { 1867 int bytes = bi->bi_size; 1868 1869 return_bi = bi->bi_next; 1870 bi->bi_next = NULL; 1871 bi->bi_size = 0; 1872 bi->bi_end_io(bi, bytes, 0); 1873 } 1874 for (i=disks; i-- ;) { 1875 int rw; 1876 struct bio *bi; 1877 mdk_rdev_t *rdev; 1878 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) 1879 rw = 1; 1880 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 1881 rw = 0; 1882 else 1883 continue; 1884 1885 bi = &sh->dev[i].req; 1886 1887 bi->bi_rw = rw; 1888 if (rw) 1889 bi->bi_end_io = raid5_end_write_request; 1890 else 1891 bi->bi_end_io = raid5_end_read_request; 1892 1893 rcu_read_lock(); 1894 rdev = rcu_dereference(conf->disks[i].rdev); 1895 if (rdev && test_bit(Faulty, &rdev->flags)) 1896 rdev = NULL; 1897 if (rdev) 1898 atomic_inc(&rdev->nr_pending); 1899 rcu_read_unlock(); 1900 1901 if (rdev) { 1902 if (syncing || expanding || expanded) 1903 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 1904 1905 bi->bi_bdev = rdev->bdev; 1906 PRINTK("for %llu schedule op %ld on disc %d\n", 1907 (unsigned long long)sh->sector, bi->bi_rw, i); 1908 atomic_inc(&sh->count); 1909 bi->bi_sector = sh->sector + rdev->data_offset; 1910 bi->bi_flags = 1 << BIO_UPTODATE; 1911 bi->bi_vcnt = 1; 1912 bi->bi_max_vecs = 1; 1913 bi->bi_idx = 0; 1914 bi->bi_io_vec = &sh->dev[i].vec; 1915 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 1916 bi->bi_io_vec[0].bv_offset = 0; 1917 bi->bi_size = STRIPE_SIZE; 1918 bi->bi_next = NULL; 1919 if (rw == WRITE && 1920 test_bit(R5_ReWrite, &sh->dev[i].flags)) 1921 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); 1922 generic_make_request(bi); 1923 } else { 1924 if (rw == 1) 1925 set_bit(STRIPE_DEGRADED, &sh->state); 1926 PRINTK("skip op %ld on disc %d for sector %llu\n", 1927 bi->bi_rw, i, (unsigned long long)sh->sector); 1928 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1929 set_bit(STRIPE_HANDLE, &sh->state); 1930 } 1931 } 1932 } 1933 1934 static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page) 1935 { 1936 raid6_conf_t *conf = sh->raid_conf; 1937 int disks = conf->raid_disks; 1938 struct bio *return_bi= NULL; 1939 struct bio *bi; 1940 int i; 1941 int syncing; 1942 int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; 1943 int non_overwrite = 0; 1944 int failed_num[2] = {0, 0}; 1945 struct r5dev *dev, *pdev, *qdev; 1946 int pd_idx = sh->pd_idx; 1947 int qd_idx = raid6_next_disk(pd_idx, disks); 1948 int p_failed, q_failed; 1949 1950 PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n", 1951 (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count), 1952 pd_idx, qd_idx); 1953 1954 spin_lock(&sh->lock); 1955 clear_bit(STRIPE_HANDLE, &sh->state); 1956 clear_bit(STRIPE_DELAYED, &sh->state); 1957 1958 syncing = test_bit(STRIPE_SYNCING, &sh->state); 1959 /* Now to look around and see what can be done */ 1960 1961 rcu_read_lock(); 1962 for (i=disks; i--; ) { 1963 mdk_rdev_t *rdev; 1964 dev = &sh->dev[i]; 1965 clear_bit(R5_Insync, &dev->flags); 1966 1967 PRINTK("check %d: state 0x%lx read %p write %p written %p\n", 1968 i, dev->flags, dev->toread, dev->towrite, dev->written); 1969 /* maybe we can reply to a read */ 1970 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { 1971 struct bio *rbi, *rbi2; 1972 PRINTK("Return read for disc %d\n", i); 1973 spin_lock_irq(&conf->device_lock); 1974 rbi = dev->toread; 1975 dev->toread = NULL; 1976 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1977 wake_up(&conf->wait_for_overlap); 1978 spin_unlock_irq(&conf->device_lock); 1979 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { 1980 copy_data(0, rbi, dev->page, dev->sector); 1981 rbi2 = r5_next_bio(rbi, dev->sector); 1982 spin_lock_irq(&conf->device_lock); 1983 if (--rbi->bi_phys_segments == 0) { 1984 rbi->bi_next = return_bi; 1985 return_bi = rbi; 1986 } 1987 spin_unlock_irq(&conf->device_lock); 1988 rbi = rbi2; 1989 } 1990 } 1991 1992 /* now count some things */ 1993 if (test_bit(R5_LOCKED, &dev->flags)) locked++; 1994 if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; 1995 1996 1997 if (dev->toread) to_read++; 1998 if (dev->towrite) { 1999 to_write++; 2000 if (!test_bit(R5_OVERWRITE, &dev->flags)) 2001 non_overwrite++; 2002 } 2003 if (dev->written) written++; 2004 rdev = rcu_dereference(conf->disks[i].rdev); 2005 if (!rdev || !test_bit(In_sync, &rdev->flags)) { 2006 /* The ReadError flag will just be confusing now */ 2007 clear_bit(R5_ReadError, &dev->flags); 2008 clear_bit(R5_ReWrite, &dev->flags); 2009 } 2010 if (!rdev || !test_bit(In_sync, &rdev->flags) 2011 || test_bit(R5_ReadError, &dev->flags)) { 2012 if ( failed < 2 ) 2013 failed_num[failed] = i; 2014 failed++; 2015 } else 2016 set_bit(R5_Insync, &dev->flags); 2017 } 2018 rcu_read_unlock(); 2019 PRINTK("locked=%d uptodate=%d to_read=%d" 2020 " to_write=%d failed=%d failed_num=%d,%d\n", 2021 locked, uptodate, to_read, to_write, failed, 2022 failed_num[0], failed_num[1]); 2023 /* check if the array has lost >2 devices and, if so, some requests might 2024 * need to be failed 2025 */ 2026 if (failed > 2 && to_read+to_write+written) { 2027 for (i=disks; i--; ) { 2028 int bitmap_end = 0; 2029 2030 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 2031 mdk_rdev_t *rdev; 2032 rcu_read_lock(); 2033 rdev = rcu_dereference(conf->disks[i].rdev); 2034 if (rdev && test_bit(In_sync, &rdev->flags)) 2035 /* multiple read failures in one stripe */ 2036 md_error(conf->mddev, rdev); 2037 rcu_read_unlock(); 2038 } 2039 2040 spin_lock_irq(&conf->device_lock); 2041 /* fail all writes first */ 2042 bi = sh->dev[i].towrite; 2043 sh->dev[i].towrite = NULL; 2044 if (bi) { to_write--; bitmap_end = 1; } 2045 2046 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2047 wake_up(&conf->wait_for_overlap); 2048 2049 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ 2050 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2051 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2052 if (--bi->bi_phys_segments == 0) { 2053 md_write_end(conf->mddev); 2054 bi->bi_next = return_bi; 2055 return_bi = bi; 2056 } 2057 bi = nextbi; 2058 } 2059 /* and fail all 'written' */ 2060 bi = sh->dev[i].written; 2061 sh->dev[i].written = NULL; 2062 if (bi) bitmap_end = 1; 2063 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { 2064 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 2065 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2066 if (--bi->bi_phys_segments == 0) { 2067 md_write_end(conf->mddev); 2068 bi->bi_next = return_bi; 2069 return_bi = bi; 2070 } 2071 bi = bi2; 2072 } 2073 2074 /* fail any reads if this device is non-operational */ 2075 if (!test_bit(R5_Insync, &sh->dev[i].flags) || 2076 test_bit(R5_ReadError, &sh->dev[i].flags)) { 2077 bi = sh->dev[i].toread; 2078 sh->dev[i].toread = NULL; 2079 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2080 wake_up(&conf->wait_for_overlap); 2081 if (bi) to_read--; 2082 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){ 2083 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2084 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2085 if (--bi->bi_phys_segments == 0) { 2086 bi->bi_next = return_bi; 2087 return_bi = bi; 2088 } 2089 bi = nextbi; 2090 } 2091 } 2092 spin_unlock_irq(&conf->device_lock); 2093 if (bitmap_end) 2094 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2095 STRIPE_SECTORS, 0, 0); 2096 } 2097 } 2098 if (failed > 2 && syncing) { 2099 md_done_sync(conf->mddev, STRIPE_SECTORS,0); 2100 clear_bit(STRIPE_SYNCING, &sh->state); 2101 syncing = 0; 2102 } 2103 2104 /* 2105 * might be able to return some write requests if the parity blocks 2106 * are safe, or on a failed drive 2107 */ 2108 pdev = &sh->dev[pd_idx]; 2109 p_failed = (failed >= 1 && failed_num[0] == pd_idx) 2110 || (failed >= 2 && failed_num[1] == pd_idx); 2111 qdev = &sh->dev[qd_idx]; 2112 q_failed = (failed >= 1 && failed_num[0] == qd_idx) 2113 || (failed >= 2 && failed_num[1] == qd_idx); 2114 2115 if ( written && 2116 ( p_failed || ((test_bit(R5_Insync, &pdev->flags) 2117 && !test_bit(R5_LOCKED, &pdev->flags) 2118 && test_bit(R5_UPTODATE, &pdev->flags))) ) && 2119 ( q_failed || ((test_bit(R5_Insync, &qdev->flags) 2120 && !test_bit(R5_LOCKED, &qdev->flags) 2121 && test_bit(R5_UPTODATE, &qdev->flags))) ) ) { 2122 /* any written block on an uptodate or failed drive can be 2123 * returned. Note that if we 'wrote' to a failed drive, 2124 * it will be UPTODATE, but never LOCKED, so we don't need 2125 * to test 'failed' directly. 2126 */ 2127 for (i=disks; i--; ) 2128 if (sh->dev[i].written) { 2129 dev = &sh->dev[i]; 2130 if (!test_bit(R5_LOCKED, &dev->flags) && 2131 test_bit(R5_UPTODATE, &dev->flags) ) { 2132 /* We can return any write requests */ 2133 int bitmap_end = 0; 2134 struct bio *wbi, *wbi2; 2135 PRINTK("Return write for stripe %llu disc %d\n", 2136 (unsigned long long)sh->sector, i); 2137 spin_lock_irq(&conf->device_lock); 2138 wbi = dev->written; 2139 dev->written = NULL; 2140 while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { 2141 wbi2 = r5_next_bio(wbi, dev->sector); 2142 if (--wbi->bi_phys_segments == 0) { 2143 md_write_end(conf->mddev); 2144 wbi->bi_next = return_bi; 2145 return_bi = wbi; 2146 } 2147 wbi = wbi2; 2148 } 2149 if (dev->towrite == NULL) 2150 bitmap_end = 1; 2151 spin_unlock_irq(&conf->device_lock); 2152 if (bitmap_end) 2153 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2154 STRIPE_SECTORS, 2155 !test_bit(STRIPE_DEGRADED, &sh->state), 0); 2156 } 2157 } 2158 } 2159 2160 /* Now we might consider reading some blocks, either to check/generate 2161 * parity, or to satisfy requests 2162 * or to load a block that is being partially written. 2163 */ 2164 if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) { 2165 for (i=disks; i--;) { 2166 dev = &sh->dev[i]; 2167 if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && 2168 (dev->toread || 2169 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 2170 syncing || 2171 (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) || 2172 (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write)) 2173 ) 2174 ) { 2175 /* we would like to get this block, possibly 2176 * by computing it, but we might not be able to 2177 */ 2178 if (uptodate == disks-1) { 2179 PRINTK("Computing stripe %llu block %d\n", 2180 (unsigned long long)sh->sector, i); 2181 compute_block_1(sh, i, 0); 2182 uptodate++; 2183 } else if ( uptodate == disks-2 && failed >= 2 ) { 2184 /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */ 2185 int other; 2186 for (other=disks; other--;) { 2187 if ( other == i ) 2188 continue; 2189 if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) ) 2190 break; 2191 } 2192 BUG_ON(other < 0); 2193 PRINTK("Computing stripe %llu blocks %d,%d\n", 2194 (unsigned long long)sh->sector, i, other); 2195 compute_block_2(sh, i, other); 2196 uptodate += 2; 2197 } else if (test_bit(R5_Insync, &dev->flags)) { 2198 set_bit(R5_LOCKED, &dev->flags); 2199 set_bit(R5_Wantread, &dev->flags); 2200 #if 0 2201 /* if I am just reading this block and we don't have 2202 a failed drive, or any pending writes then sidestep the cache */ 2203 if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext && 2204 ! syncing && !failed && !to_write) { 2205 sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page; 2206 sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data; 2207 } 2208 #endif 2209 locked++; 2210 PRINTK("Reading block %d (sync=%d)\n", 2211 i, syncing); 2212 } 2213 } 2214 } 2215 set_bit(STRIPE_HANDLE, &sh->state); 2216 } 2217 2218 /* now to consider writing and what else, if anything should be read */ 2219 if (to_write) { 2220 int rcw=0, must_compute=0; 2221 for (i=disks ; i--;) { 2222 dev = &sh->dev[i]; 2223 /* Would I have to read this buffer for reconstruct_write */ 2224 if (!test_bit(R5_OVERWRITE, &dev->flags) 2225 && i != pd_idx && i != qd_idx 2226 && (!test_bit(R5_LOCKED, &dev->flags) 2227 #if 0 2228 || sh->bh_page[i] != bh->b_page 2229 #endif 2230 ) && 2231 !test_bit(R5_UPTODATE, &dev->flags)) { 2232 if (test_bit(R5_Insync, &dev->flags)) rcw++; 2233 else { 2234 PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags); 2235 must_compute++; 2236 } 2237 } 2238 } 2239 PRINTK("for sector %llu, rcw=%d, must_compute=%d\n", 2240 (unsigned long long)sh->sector, rcw, must_compute); 2241 set_bit(STRIPE_HANDLE, &sh->state); 2242 2243 if (rcw > 0) 2244 /* want reconstruct write, but need to get some data */ 2245 for (i=disks; i--;) { 2246 dev = &sh->dev[i]; 2247 if (!test_bit(R5_OVERWRITE, &dev->flags) 2248 && !(failed == 0 && (i == pd_idx || i == qd_idx)) 2249 && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && 2250 test_bit(R5_Insync, &dev->flags)) { 2251 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 2252 { 2253 PRINTK("Read_old stripe %llu block %d for Reconstruct\n", 2254 (unsigned long long)sh->sector, i); 2255 set_bit(R5_LOCKED, &dev->flags); 2256 set_bit(R5_Wantread, &dev->flags); 2257 locked++; 2258 } else { 2259 PRINTK("Request delayed stripe %llu block %d for Reconstruct\n", 2260 (unsigned long long)sh->sector, i); 2261 set_bit(STRIPE_DELAYED, &sh->state); 2262 set_bit(STRIPE_HANDLE, &sh->state); 2263 } 2264 } 2265 } 2266 /* now if nothing is locked, and if we have enough data, we can start a write request */ 2267 if (locked == 0 && rcw == 0 && 2268 !test_bit(STRIPE_BIT_DELAY, &sh->state)) { 2269 if ( must_compute > 0 ) { 2270 /* We have failed blocks and need to compute them */ 2271 switch ( failed ) { 2272 case 0: BUG(); 2273 case 1: compute_block_1(sh, failed_num[0], 0); break; 2274 case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break; 2275 default: BUG(); /* This request should have been failed? */ 2276 } 2277 } 2278 2279 PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector); 2280 compute_parity6(sh, RECONSTRUCT_WRITE); 2281 /* now every locked buffer is ready to be written */ 2282 for (i=disks; i--;) 2283 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { 2284 PRINTK("Writing stripe %llu block %d\n", 2285 (unsigned long long)sh->sector, i); 2286 locked++; 2287 set_bit(R5_Wantwrite, &sh->dev[i].flags); 2288 } 2289 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */ 2290 set_bit(STRIPE_INSYNC, &sh->state); 2291 2292 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2293 atomic_dec(&conf->preread_active_stripes); 2294 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 2295 md_wakeup_thread(conf->mddev->thread); 2296 } 2297 } 2298 } 2299 2300 /* maybe we need to check and possibly fix the parity for this stripe 2301 * Any reads will already have been scheduled, so we just see if enough data 2302 * is available 2303 */ 2304 if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) { 2305 int update_p = 0, update_q = 0; 2306 struct r5dev *dev; 2307 2308 set_bit(STRIPE_HANDLE, &sh->state); 2309 2310 BUG_ON(failed>2); 2311 BUG_ON(uptodate < disks); 2312 /* Want to check and possibly repair P and Q. 2313 * However there could be one 'failed' device, in which 2314 * case we can only check one of them, possibly using the 2315 * other to generate missing data 2316 */ 2317 2318 /* If !tmp_page, we cannot do the calculations, 2319 * but as we have set STRIPE_HANDLE, we will soon be called 2320 * by stripe_handle with a tmp_page - just wait until then. 2321 */ 2322 if (tmp_page) { 2323 if (failed == q_failed) { 2324 /* The only possible failed device holds 'Q', so it makes 2325 * sense to check P (If anything else were failed, we would 2326 * have used P to recreate it). 2327 */ 2328 compute_block_1(sh, pd_idx, 1); 2329 if (!page_is_zero(sh->dev[pd_idx].page)) { 2330 compute_block_1(sh,pd_idx,0); 2331 update_p = 1; 2332 } 2333 } 2334 if (!q_failed && failed < 2) { 2335 /* q is not failed, and we didn't use it to generate 2336 * anything, so it makes sense to check it 2337 */ 2338 memcpy(page_address(tmp_page), 2339 page_address(sh->dev[qd_idx].page), 2340 STRIPE_SIZE); 2341 compute_parity6(sh, UPDATE_PARITY); 2342 if (memcmp(page_address(tmp_page), 2343 page_address(sh->dev[qd_idx].page), 2344 STRIPE_SIZE)!= 0) { 2345 clear_bit(STRIPE_INSYNC, &sh->state); 2346 update_q = 1; 2347 } 2348 } 2349 if (update_p || update_q) { 2350 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2351 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2352 /* don't try to repair!! */ 2353 update_p = update_q = 0; 2354 } 2355 2356 /* now write out any block on a failed drive, 2357 * or P or Q if they need it 2358 */ 2359 2360 if (failed == 2) { 2361 dev = &sh->dev[failed_num[1]]; 2362 locked++; 2363 set_bit(R5_LOCKED, &dev->flags); 2364 set_bit(R5_Wantwrite, &dev->flags); 2365 } 2366 if (failed >= 1) { 2367 dev = &sh->dev[failed_num[0]]; 2368 locked++; 2369 set_bit(R5_LOCKED, &dev->flags); 2370 set_bit(R5_Wantwrite, &dev->flags); 2371 } 2372 2373 if (update_p) { 2374 dev = &sh->dev[pd_idx]; 2375 locked ++; 2376 set_bit(R5_LOCKED, &dev->flags); 2377 set_bit(R5_Wantwrite, &dev->flags); 2378 } 2379 if (update_q) { 2380 dev = &sh->dev[qd_idx]; 2381 locked++; 2382 set_bit(R5_LOCKED, &dev->flags); 2383 set_bit(R5_Wantwrite, &dev->flags); 2384 } 2385 clear_bit(STRIPE_DEGRADED, &sh->state); 2386 2387 set_bit(STRIPE_INSYNC, &sh->state); 2388 } 2389 } 2390 2391 if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { 2392 md_done_sync(conf->mddev, STRIPE_SECTORS,1); 2393 clear_bit(STRIPE_SYNCING, &sh->state); 2394 } 2395 2396 /* If the failed drives are just a ReadError, then we might need 2397 * to progress the repair/check process 2398 */ 2399 if (failed <= 2 && ! conf->mddev->ro) 2400 for (i=0; i<failed;i++) { 2401 dev = &sh->dev[failed_num[i]]; 2402 if (test_bit(R5_ReadError, &dev->flags) 2403 && !test_bit(R5_LOCKED, &dev->flags) 2404 && test_bit(R5_UPTODATE, &dev->flags) 2405 ) { 2406 if (!test_bit(R5_ReWrite, &dev->flags)) { 2407 set_bit(R5_Wantwrite, &dev->flags); 2408 set_bit(R5_ReWrite, &dev->flags); 2409 set_bit(R5_LOCKED, &dev->flags); 2410 } else { 2411 /* let's read it back */ 2412 set_bit(R5_Wantread, &dev->flags); 2413 set_bit(R5_LOCKED, &dev->flags); 2414 } 2415 } 2416 } 2417 spin_unlock(&sh->lock); 2418 2419 while ((bi=return_bi)) { 2420 int bytes = bi->bi_size; 2421 2422 return_bi = bi->bi_next; 2423 bi->bi_next = NULL; 2424 bi->bi_size = 0; 2425 bi->bi_end_io(bi, bytes, 0); 2426 } 2427 for (i=disks; i-- ;) { 2428 int rw; 2429 struct bio *bi; 2430 mdk_rdev_t *rdev; 2431 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) 2432 rw = 1; 2433 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 2434 rw = 0; 2435 else 2436 continue; 2437 2438 bi = &sh->dev[i].req; 2439 2440 bi->bi_rw = rw; 2441 if (rw) 2442 bi->bi_end_io = raid5_end_write_request; 2443 else 2444 bi->bi_end_io = raid5_end_read_request; 2445 2446 rcu_read_lock(); 2447 rdev = rcu_dereference(conf->disks[i].rdev); 2448 if (rdev && test_bit(Faulty, &rdev->flags)) 2449 rdev = NULL; 2450 if (rdev) 2451 atomic_inc(&rdev->nr_pending); 2452 rcu_read_unlock(); 2453 2454 if (rdev) { 2455 if (syncing) 2456 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 2457 2458 bi->bi_bdev = rdev->bdev; 2459 PRINTK("for %llu schedule op %ld on disc %d\n", 2460 (unsigned long long)sh->sector, bi->bi_rw, i); 2461 atomic_inc(&sh->count); 2462 bi->bi_sector = sh->sector + rdev->data_offset; 2463 bi->bi_flags = 1 << BIO_UPTODATE; 2464 bi->bi_vcnt = 1; 2465 bi->bi_max_vecs = 1; 2466 bi->bi_idx = 0; 2467 bi->bi_io_vec = &sh->dev[i].vec; 2468 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 2469 bi->bi_io_vec[0].bv_offset = 0; 2470 bi->bi_size = STRIPE_SIZE; 2471 bi->bi_next = NULL; 2472 if (rw == WRITE && 2473 test_bit(R5_ReWrite, &sh->dev[i].flags)) 2474 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); 2475 generic_make_request(bi); 2476 } else { 2477 if (rw == 1) 2478 set_bit(STRIPE_DEGRADED, &sh->state); 2479 PRINTK("skip op %ld on disc %d for sector %llu\n", 2480 bi->bi_rw, i, (unsigned long long)sh->sector); 2481 clear_bit(R5_LOCKED, &sh->dev[i].flags); 2482 set_bit(STRIPE_HANDLE, &sh->state); 2483 } 2484 } 2485 } 2486 2487 static void handle_stripe(struct stripe_head *sh, struct page *tmp_page) 2488 { 2489 if (sh->raid_conf->level == 6) 2490 handle_stripe6(sh, tmp_page); 2491 else 2492 handle_stripe5(sh); 2493 } 2494 2495 2496 2497 static void raid5_activate_delayed(raid5_conf_t *conf) 2498 { 2499 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 2500 while (!list_empty(&conf->delayed_list)) { 2501 struct list_head *l = conf->delayed_list.next; 2502 struct stripe_head *sh; 2503 sh = list_entry(l, struct stripe_head, lru); 2504 list_del_init(l); 2505 clear_bit(STRIPE_DELAYED, &sh->state); 2506 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 2507 atomic_inc(&conf->preread_active_stripes); 2508 list_add_tail(&sh->lru, &conf->handle_list); 2509 } 2510 } 2511 } 2512 2513 static void activate_bit_delay(raid5_conf_t *conf) 2514 { 2515 /* device_lock is held */ 2516 struct list_head head; 2517 list_add(&head, &conf->bitmap_list); 2518 list_del_init(&conf->bitmap_list); 2519 while (!list_empty(&head)) { 2520 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); 2521 list_del_init(&sh->lru); 2522 atomic_inc(&sh->count); 2523 __release_stripe(conf, sh); 2524 } 2525 } 2526 2527 static void unplug_slaves(mddev_t *mddev) 2528 { 2529 raid5_conf_t *conf = mddev_to_conf(mddev); 2530 int i; 2531 2532 rcu_read_lock(); 2533 for (i=0; i<mddev->raid_disks; i++) { 2534 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 2535 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { 2536 request_queue_t *r_queue = bdev_get_queue(rdev->bdev); 2537 2538 atomic_inc(&rdev->nr_pending); 2539 rcu_read_unlock(); 2540 2541 if (r_queue->unplug_fn) 2542 r_queue->unplug_fn(r_queue); 2543 2544 rdev_dec_pending(rdev, mddev); 2545 rcu_read_lock(); 2546 } 2547 } 2548 rcu_read_unlock(); 2549 } 2550 2551 static void raid5_unplug_device(request_queue_t *q) 2552 { 2553 mddev_t *mddev = q->queuedata; 2554 raid5_conf_t *conf = mddev_to_conf(mddev); 2555 unsigned long flags; 2556 2557 spin_lock_irqsave(&conf->device_lock, flags); 2558 2559 if (blk_remove_plug(q)) { 2560 conf->seq_flush++; 2561 raid5_activate_delayed(conf); 2562 } 2563 md_wakeup_thread(mddev->thread); 2564 2565 spin_unlock_irqrestore(&conf->device_lock, flags); 2566 2567 unplug_slaves(mddev); 2568 } 2569 2570 static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk, 2571 sector_t *error_sector) 2572 { 2573 mddev_t *mddev = q->queuedata; 2574 raid5_conf_t *conf = mddev_to_conf(mddev); 2575 int i, ret = 0; 2576 2577 rcu_read_lock(); 2578 for (i=0; i<mddev->raid_disks && ret == 0; i++) { 2579 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 2580 if (rdev && !test_bit(Faulty, &rdev->flags)) { 2581 struct block_device *bdev = rdev->bdev; 2582 request_queue_t *r_queue = bdev_get_queue(bdev); 2583 2584 if (!r_queue->issue_flush_fn) 2585 ret = -EOPNOTSUPP; 2586 else { 2587 atomic_inc(&rdev->nr_pending); 2588 rcu_read_unlock(); 2589 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, 2590 error_sector); 2591 rdev_dec_pending(rdev, mddev); 2592 rcu_read_lock(); 2593 } 2594 } 2595 } 2596 rcu_read_unlock(); 2597 return ret; 2598 } 2599 2600 static int make_request(request_queue_t *q, struct bio * bi) 2601 { 2602 mddev_t *mddev = q->queuedata; 2603 raid5_conf_t *conf = mddev_to_conf(mddev); 2604 unsigned int dd_idx, pd_idx; 2605 sector_t new_sector; 2606 sector_t logical_sector, last_sector; 2607 struct stripe_head *sh; 2608 const int rw = bio_data_dir(bi); 2609 int remaining; 2610 2611 if (unlikely(bio_barrier(bi))) { 2612 bio_endio(bi, bi->bi_size, -EOPNOTSUPP); 2613 return 0; 2614 } 2615 2616 md_write_start(mddev, bi); 2617 2618 disk_stat_inc(mddev->gendisk, ios[rw]); 2619 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi)); 2620 2621 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 2622 last_sector = bi->bi_sector + (bi->bi_size>>9); 2623 bi->bi_next = NULL; 2624 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ 2625 2626 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 2627 DEFINE_WAIT(w); 2628 int disks, data_disks; 2629 2630 retry: 2631 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 2632 if (likely(conf->expand_progress == MaxSector)) 2633 disks = conf->raid_disks; 2634 else { 2635 /* spinlock is needed as expand_progress may be 2636 * 64bit on a 32bit platform, and so it might be 2637 * possible to see a half-updated value 2638 * Ofcourse expand_progress could change after 2639 * the lock is dropped, so once we get a reference 2640 * to the stripe that we think it is, we will have 2641 * to check again. 2642 */ 2643 spin_lock_irq(&conf->device_lock); 2644 disks = conf->raid_disks; 2645 if (logical_sector >= conf->expand_progress) 2646 disks = conf->previous_raid_disks; 2647 else { 2648 if (logical_sector >= conf->expand_lo) { 2649 spin_unlock_irq(&conf->device_lock); 2650 schedule(); 2651 goto retry; 2652 } 2653 } 2654 spin_unlock_irq(&conf->device_lock); 2655 } 2656 data_disks = disks - conf->max_degraded; 2657 2658 new_sector = raid5_compute_sector(logical_sector, disks, data_disks, 2659 &dd_idx, &pd_idx, conf); 2660 PRINTK("raid5: make_request, sector %llu logical %llu\n", 2661 (unsigned long long)new_sector, 2662 (unsigned long long)logical_sector); 2663 2664 sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); 2665 if (sh) { 2666 if (unlikely(conf->expand_progress != MaxSector)) { 2667 /* expansion might have moved on while waiting for a 2668 * stripe, so we must do the range check again. 2669 * Expansion could still move past after this 2670 * test, but as we are holding a reference to 2671 * 'sh', we know that if that happens, 2672 * STRIPE_EXPANDING will get set and the expansion 2673 * won't proceed until we finish with the stripe. 2674 */ 2675 int must_retry = 0; 2676 spin_lock_irq(&conf->device_lock); 2677 if (logical_sector < conf->expand_progress && 2678 disks == conf->previous_raid_disks) 2679 /* mismatch, need to try again */ 2680 must_retry = 1; 2681 spin_unlock_irq(&conf->device_lock); 2682 if (must_retry) { 2683 release_stripe(sh); 2684 goto retry; 2685 } 2686 } 2687 /* FIXME what if we get a false positive because these 2688 * are being updated. 2689 */ 2690 if (logical_sector >= mddev->suspend_lo && 2691 logical_sector < mddev->suspend_hi) { 2692 release_stripe(sh); 2693 schedule(); 2694 goto retry; 2695 } 2696 2697 if (test_bit(STRIPE_EXPANDING, &sh->state) || 2698 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) { 2699 /* Stripe is busy expanding or 2700 * add failed due to overlap. Flush everything 2701 * and wait a while 2702 */ 2703 raid5_unplug_device(mddev->queue); 2704 release_stripe(sh); 2705 schedule(); 2706 goto retry; 2707 } 2708 finish_wait(&conf->wait_for_overlap, &w); 2709 handle_stripe(sh, NULL); 2710 release_stripe(sh); 2711 } else { 2712 /* cannot get stripe for read-ahead, just give-up */ 2713 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2714 finish_wait(&conf->wait_for_overlap, &w); 2715 break; 2716 } 2717 2718 } 2719 spin_lock_irq(&conf->device_lock); 2720 remaining = --bi->bi_phys_segments; 2721 spin_unlock_irq(&conf->device_lock); 2722 if (remaining == 0) { 2723 int bytes = bi->bi_size; 2724 2725 if ( rw == WRITE ) 2726 md_write_end(mddev); 2727 bi->bi_size = 0; 2728 bi->bi_end_io(bi, bytes, 0); 2729 } 2730 return 0; 2731 } 2732 2733 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) 2734 { 2735 /* reshaping is quite different to recovery/resync so it is 2736 * handled quite separately ... here. 2737 * 2738 * On each call to sync_request, we gather one chunk worth of 2739 * destination stripes and flag them as expanding. 2740 * Then we find all the source stripes and request reads. 2741 * As the reads complete, handle_stripe will copy the data 2742 * into the destination stripe and release that stripe. 2743 */ 2744 raid5_conf_t *conf = (raid5_conf_t *) mddev->private; 2745 struct stripe_head *sh; 2746 int pd_idx; 2747 sector_t first_sector, last_sector; 2748 int raid_disks; 2749 int data_disks; 2750 int i; 2751 int dd_idx; 2752 sector_t writepos, safepos, gap; 2753 2754 if (sector_nr == 0 && 2755 conf->expand_progress != 0) { 2756 /* restarting in the middle, skip the initial sectors */ 2757 sector_nr = conf->expand_progress; 2758 sector_div(sector_nr, conf->raid_disks-1); 2759 *skipped = 1; 2760 return sector_nr; 2761 } 2762 2763 /* we update the metadata when there is more than 3Meg 2764 * in the block range (that is rather arbitrary, should 2765 * probably be time based) or when the data about to be 2766 * copied would over-write the source of the data at 2767 * the front of the range. 2768 * i.e. one new_stripe forward from expand_progress new_maps 2769 * to after where expand_lo old_maps to 2770 */ 2771 writepos = conf->expand_progress + 2772 conf->chunk_size/512*(conf->raid_disks-1); 2773 sector_div(writepos, conf->raid_disks-1); 2774 safepos = conf->expand_lo; 2775 sector_div(safepos, conf->previous_raid_disks-1); 2776 gap = conf->expand_progress - conf->expand_lo; 2777 2778 if (writepos >= safepos || 2779 gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) { 2780 /* Cannot proceed until we've updated the superblock... */ 2781 wait_event(conf->wait_for_overlap, 2782 atomic_read(&conf->reshape_stripes)==0); 2783 mddev->reshape_position = conf->expand_progress; 2784 mddev->sb_dirty = 1; 2785 md_wakeup_thread(mddev->thread); 2786 wait_event(mddev->sb_wait, mddev->sb_dirty == 0 || 2787 kthread_should_stop()); 2788 spin_lock_irq(&conf->device_lock); 2789 conf->expand_lo = mddev->reshape_position; 2790 spin_unlock_irq(&conf->device_lock); 2791 wake_up(&conf->wait_for_overlap); 2792 } 2793 2794 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { 2795 int j; 2796 int skipped = 0; 2797 pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks); 2798 sh = get_active_stripe(conf, sector_nr+i, 2799 conf->raid_disks, pd_idx, 0); 2800 set_bit(STRIPE_EXPANDING, &sh->state); 2801 atomic_inc(&conf->reshape_stripes); 2802 /* If any of this stripe is beyond the end of the old 2803 * array, then we need to zero those blocks 2804 */ 2805 for (j=sh->disks; j--;) { 2806 sector_t s; 2807 if (j == sh->pd_idx) 2808 continue; 2809 s = compute_blocknr(sh, j); 2810 if (s < (mddev->array_size<<1)) { 2811 skipped = 1; 2812 continue; 2813 } 2814 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); 2815 set_bit(R5_Expanded, &sh->dev[j].flags); 2816 set_bit(R5_UPTODATE, &sh->dev[j].flags); 2817 } 2818 if (!skipped) { 2819 set_bit(STRIPE_EXPAND_READY, &sh->state); 2820 set_bit(STRIPE_HANDLE, &sh->state); 2821 } 2822 release_stripe(sh); 2823 } 2824 spin_lock_irq(&conf->device_lock); 2825 conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1); 2826 spin_unlock_irq(&conf->device_lock); 2827 /* Ok, those stripe are ready. We can start scheduling 2828 * reads on the source stripes. 2829 * The source stripes are determined by mapping the first and last 2830 * block on the destination stripes. 2831 */ 2832 raid_disks = conf->previous_raid_disks; 2833 data_disks = raid_disks - 1; 2834 first_sector = 2835 raid5_compute_sector(sector_nr*(conf->raid_disks-1), 2836 raid_disks, data_disks, 2837 &dd_idx, &pd_idx, conf); 2838 last_sector = 2839 raid5_compute_sector((sector_nr+conf->chunk_size/512) 2840 *(conf->raid_disks-1) -1, 2841 raid_disks, data_disks, 2842 &dd_idx, &pd_idx, conf); 2843 if (last_sector >= (mddev->size<<1)) 2844 last_sector = (mddev->size<<1)-1; 2845 while (first_sector <= last_sector) { 2846 pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks); 2847 sh = get_active_stripe(conf, first_sector, 2848 conf->previous_raid_disks, pd_idx, 0); 2849 set_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2850 set_bit(STRIPE_HANDLE, &sh->state); 2851 release_stripe(sh); 2852 first_sector += STRIPE_SECTORS; 2853 } 2854 return conf->chunk_size>>9; 2855 } 2856 2857 /* FIXME go_faster isn't used */ 2858 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) 2859 { 2860 raid5_conf_t *conf = (raid5_conf_t *) mddev->private; 2861 struct stripe_head *sh; 2862 int pd_idx; 2863 int raid_disks = conf->raid_disks; 2864 sector_t max_sector = mddev->size << 1; 2865 int sync_blocks; 2866 int still_degraded = 0; 2867 int i; 2868 2869 if (sector_nr >= max_sector) { 2870 /* just being told to finish up .. nothing much to do */ 2871 unplug_slaves(mddev); 2872 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { 2873 end_reshape(conf); 2874 return 0; 2875 } 2876 2877 if (mddev->curr_resync < max_sector) /* aborted */ 2878 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 2879 &sync_blocks, 1); 2880 else /* completed sync */ 2881 conf->fullsync = 0; 2882 bitmap_close_sync(mddev->bitmap); 2883 2884 return 0; 2885 } 2886 2887 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) 2888 return reshape_request(mddev, sector_nr, skipped); 2889 2890 /* if there is too many failed drives and we are trying 2891 * to resync, then assert that we are finished, because there is 2892 * nothing we can do. 2893 */ 2894 if (mddev->degraded >= conf->max_degraded && 2895 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 2896 sector_t rv = (mddev->size << 1) - sector_nr; 2897 *skipped = 1; 2898 return rv; 2899 } 2900 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 2901 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 2902 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { 2903 /* we can skip this block, and probably more */ 2904 sync_blocks /= STRIPE_SECTORS; 2905 *skipped = 1; 2906 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ 2907 } 2908 2909 pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks); 2910 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1); 2911 if (sh == NULL) { 2912 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); 2913 /* make sure we don't swamp the stripe cache if someone else 2914 * is trying to get access 2915 */ 2916 schedule_timeout_uninterruptible(1); 2917 } 2918 /* Need to check if array will still be degraded after recovery/resync 2919 * We don't need to check the 'failed' flag as when that gets set, 2920 * recovery aborts. 2921 */ 2922 for (i=0; i<mddev->raid_disks; i++) 2923 if (conf->disks[i].rdev == NULL) 2924 still_degraded = 1; 2925 2926 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); 2927 2928 spin_lock(&sh->lock); 2929 set_bit(STRIPE_SYNCING, &sh->state); 2930 clear_bit(STRIPE_INSYNC, &sh->state); 2931 spin_unlock(&sh->lock); 2932 2933 handle_stripe(sh, NULL); 2934 release_stripe(sh); 2935 2936 return STRIPE_SECTORS; 2937 } 2938 2939 /* 2940 * This is our raid5 kernel thread. 2941 * 2942 * We scan the hash table for stripes which can be handled now. 2943 * During the scan, completed stripes are saved for us by the interrupt 2944 * handler, so that they will not have to wait for our next wakeup. 2945 */ 2946 static void raid5d (mddev_t *mddev) 2947 { 2948 struct stripe_head *sh; 2949 raid5_conf_t *conf = mddev_to_conf(mddev); 2950 int handled; 2951 2952 PRINTK("+++ raid5d active\n"); 2953 2954 md_check_recovery(mddev); 2955 2956 handled = 0; 2957 spin_lock_irq(&conf->device_lock); 2958 while (1) { 2959 struct list_head *first; 2960 2961 if (conf->seq_flush != conf->seq_write) { 2962 int seq = conf->seq_flush; 2963 spin_unlock_irq(&conf->device_lock); 2964 bitmap_unplug(mddev->bitmap); 2965 spin_lock_irq(&conf->device_lock); 2966 conf->seq_write = seq; 2967 activate_bit_delay(conf); 2968 } 2969 2970 if (list_empty(&conf->handle_list) && 2971 atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD && 2972 !blk_queue_plugged(mddev->queue) && 2973 !list_empty(&conf->delayed_list)) 2974 raid5_activate_delayed(conf); 2975 2976 if (list_empty(&conf->handle_list)) 2977 break; 2978 2979 first = conf->handle_list.next; 2980 sh = list_entry(first, struct stripe_head, lru); 2981 2982 list_del_init(first); 2983 atomic_inc(&sh->count); 2984 BUG_ON(atomic_read(&sh->count)!= 1); 2985 spin_unlock_irq(&conf->device_lock); 2986 2987 handled++; 2988 handle_stripe(sh, conf->spare_page); 2989 release_stripe(sh); 2990 2991 spin_lock_irq(&conf->device_lock); 2992 } 2993 PRINTK("%d stripes handled\n", handled); 2994 2995 spin_unlock_irq(&conf->device_lock); 2996 2997 unplug_slaves(mddev); 2998 2999 PRINTK("--- raid5d inactive\n"); 3000 } 3001 3002 static ssize_t 3003 raid5_show_stripe_cache_size(mddev_t *mddev, char *page) 3004 { 3005 raid5_conf_t *conf = mddev_to_conf(mddev); 3006 if (conf) 3007 return sprintf(page, "%d\n", conf->max_nr_stripes); 3008 else 3009 return 0; 3010 } 3011 3012 static ssize_t 3013 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) 3014 { 3015 raid5_conf_t *conf = mddev_to_conf(mddev); 3016 char *end; 3017 int new; 3018 if (len >= PAGE_SIZE) 3019 return -EINVAL; 3020 if (!conf) 3021 return -ENODEV; 3022 3023 new = simple_strtoul(page, &end, 10); 3024 if (!*page || (*end && *end != '\n') ) 3025 return -EINVAL; 3026 if (new <= 16 || new > 32768) 3027 return -EINVAL; 3028 while (new < conf->max_nr_stripes) { 3029 if (drop_one_stripe(conf)) 3030 conf->max_nr_stripes--; 3031 else 3032 break; 3033 } 3034 while (new > conf->max_nr_stripes) { 3035 if (grow_one_stripe(conf)) 3036 conf->max_nr_stripes++; 3037 else break; 3038 } 3039 return len; 3040 } 3041 3042 static struct md_sysfs_entry 3043 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, 3044 raid5_show_stripe_cache_size, 3045 raid5_store_stripe_cache_size); 3046 3047 static ssize_t 3048 stripe_cache_active_show(mddev_t *mddev, char *page) 3049 { 3050 raid5_conf_t *conf = mddev_to_conf(mddev); 3051 if (conf) 3052 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); 3053 else 3054 return 0; 3055 } 3056 3057 static struct md_sysfs_entry 3058 raid5_stripecache_active = __ATTR_RO(stripe_cache_active); 3059 3060 static struct attribute *raid5_attrs[] = { 3061 &raid5_stripecache_size.attr, 3062 &raid5_stripecache_active.attr, 3063 NULL, 3064 }; 3065 static struct attribute_group raid5_attrs_group = { 3066 .name = NULL, 3067 .attrs = raid5_attrs, 3068 }; 3069 3070 static int run(mddev_t *mddev) 3071 { 3072 raid5_conf_t *conf; 3073 int raid_disk, memory; 3074 mdk_rdev_t *rdev; 3075 struct disk_info *disk; 3076 struct list_head *tmp; 3077 3078 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) { 3079 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n", 3080 mdname(mddev), mddev->level); 3081 return -EIO; 3082 } 3083 3084 if (mddev->reshape_position != MaxSector) { 3085 /* Check that we can continue the reshape. 3086 * Currently only disks can change, it must 3087 * increase, and we must be past the point where 3088 * a stripe over-writes itself 3089 */ 3090 sector_t here_new, here_old; 3091 int old_disks; 3092 3093 if (mddev->new_level != mddev->level || 3094 mddev->new_layout != mddev->layout || 3095 mddev->new_chunk != mddev->chunk_size) { 3096 printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n", 3097 mdname(mddev)); 3098 return -EINVAL; 3099 } 3100 if (mddev->delta_disks <= 0) { 3101 printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n", 3102 mdname(mddev)); 3103 return -EINVAL; 3104 } 3105 old_disks = mddev->raid_disks - mddev->delta_disks; 3106 /* reshape_position must be on a new-stripe boundary, and one 3107 * further up in new geometry must map after here in old geometry. 3108 */ 3109 here_new = mddev->reshape_position; 3110 if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) { 3111 printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n"); 3112 return -EINVAL; 3113 } 3114 /* here_new is the stripe we will write to */ 3115 here_old = mddev->reshape_position; 3116 sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1)); 3117 /* here_old is the first stripe that we might need to read from */ 3118 if (here_new >= here_old) { 3119 /* Reading from the same stripe as writing to - bad */ 3120 printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n"); 3121 return -EINVAL; 3122 } 3123 printk(KERN_INFO "raid5: reshape will continue\n"); 3124 /* OK, we should be able to continue; */ 3125 } 3126 3127 3128 mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL); 3129 if ((conf = mddev->private) == NULL) 3130 goto abort; 3131 if (mddev->reshape_position == MaxSector) { 3132 conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks; 3133 } else { 3134 conf->raid_disks = mddev->raid_disks; 3135 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; 3136 } 3137 3138 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info), 3139 GFP_KERNEL); 3140 if (!conf->disks) 3141 goto abort; 3142 3143 conf->mddev = mddev; 3144 3145 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 3146 goto abort; 3147 3148 if (mddev->level == 6) { 3149 conf->spare_page = alloc_page(GFP_KERNEL); 3150 if (!conf->spare_page) 3151 goto abort; 3152 } 3153 spin_lock_init(&conf->device_lock); 3154 init_waitqueue_head(&conf->wait_for_stripe); 3155 init_waitqueue_head(&conf->wait_for_overlap); 3156 INIT_LIST_HEAD(&conf->handle_list); 3157 INIT_LIST_HEAD(&conf->delayed_list); 3158 INIT_LIST_HEAD(&conf->bitmap_list); 3159 INIT_LIST_HEAD(&conf->inactive_list); 3160 atomic_set(&conf->active_stripes, 0); 3161 atomic_set(&conf->preread_active_stripes, 0); 3162 3163 PRINTK("raid5: run(%s) called.\n", mdname(mddev)); 3164 3165 ITERATE_RDEV(mddev,rdev,tmp) { 3166 raid_disk = rdev->raid_disk; 3167 if (raid_disk >= conf->raid_disks 3168 || raid_disk < 0) 3169 continue; 3170 disk = conf->disks + raid_disk; 3171 3172 disk->rdev = rdev; 3173 3174 if (test_bit(In_sync, &rdev->flags)) { 3175 char b[BDEVNAME_SIZE]; 3176 printk(KERN_INFO "raid5: device %s operational as raid" 3177 " disk %d\n", bdevname(rdev->bdev,b), 3178 raid_disk); 3179 conf->working_disks++; 3180 } 3181 } 3182 3183 /* 3184 * 0 for a fully functional array, 1 or 2 for a degraded array. 3185 */ 3186 mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; 3187 conf->mddev = mddev; 3188 conf->chunk_size = mddev->chunk_size; 3189 conf->level = mddev->level; 3190 if (conf->level == 6) 3191 conf->max_degraded = 2; 3192 else 3193 conf->max_degraded = 1; 3194 conf->algorithm = mddev->layout; 3195 conf->max_nr_stripes = NR_STRIPES; 3196 conf->expand_progress = mddev->reshape_position; 3197 3198 /* device size must be a multiple of chunk size */ 3199 mddev->size &= ~(mddev->chunk_size/1024 -1); 3200 mddev->resync_max_sectors = mddev->size << 1; 3201 3202 if (conf->level == 6 && conf->raid_disks < 4) { 3203 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n", 3204 mdname(mddev), conf->raid_disks); 3205 goto abort; 3206 } 3207 if (!conf->chunk_size || conf->chunk_size % 4) { 3208 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", 3209 conf->chunk_size, mdname(mddev)); 3210 goto abort; 3211 } 3212 if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { 3213 printk(KERN_ERR 3214 "raid5: unsupported parity algorithm %d for %s\n", 3215 conf->algorithm, mdname(mddev)); 3216 goto abort; 3217 } 3218 if (mddev->degraded > conf->max_degraded) { 3219 printk(KERN_ERR "raid5: not enough operational devices for %s" 3220 " (%d/%d failed)\n", 3221 mdname(mddev), conf->failed_disks, conf->raid_disks); 3222 goto abort; 3223 } 3224 3225 if (mddev->degraded > 0 && 3226 mddev->recovery_cp != MaxSector) { 3227 if (mddev->ok_start_degraded) 3228 printk(KERN_WARNING 3229 "raid5: starting dirty degraded array: %s" 3230 "- data corruption possible.\n", 3231 mdname(mddev)); 3232 else { 3233 printk(KERN_ERR 3234 "raid5: cannot start dirty degraded array for %s\n", 3235 mdname(mddev)); 3236 goto abort; 3237 } 3238 } 3239 3240 { 3241 mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5"); 3242 if (!mddev->thread) { 3243 printk(KERN_ERR 3244 "raid5: couldn't allocate thread for %s\n", 3245 mdname(mddev)); 3246 goto abort; 3247 } 3248 } 3249 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 3250 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; 3251 if (grow_stripes(conf, conf->max_nr_stripes)) { 3252 printk(KERN_ERR 3253 "raid5: couldn't allocate %dkB for buffers\n", memory); 3254 shrink_stripes(conf); 3255 md_unregister_thread(mddev->thread); 3256 goto abort; 3257 } else 3258 printk(KERN_INFO "raid5: allocated %dkB for %s\n", 3259 memory, mdname(mddev)); 3260 3261 if (mddev->degraded == 0) 3262 printk("raid5: raid level %d set %s active with %d out of %d" 3263 " devices, algorithm %d\n", conf->level, mdname(mddev), 3264 mddev->raid_disks-mddev->degraded, mddev->raid_disks, 3265 conf->algorithm); 3266 else 3267 printk(KERN_ALERT "raid5: raid level %d set %s active with %d" 3268 " out of %d devices, algorithm %d\n", conf->level, 3269 mdname(mddev), mddev->raid_disks - mddev->degraded, 3270 mddev->raid_disks, conf->algorithm); 3271 3272 print_raid5_conf(conf); 3273 3274 if (conf->expand_progress != MaxSector) { 3275 printk("...ok start reshape thread\n"); 3276 conf->expand_lo = conf->expand_progress; 3277 atomic_set(&conf->reshape_stripes, 0); 3278 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 3279 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 3280 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 3281 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 3282 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 3283 "%s_reshape"); 3284 } 3285 3286 /* read-ahead size must cover two whole stripes, which is 3287 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 3288 */ 3289 { 3290 int data_disks = conf->previous_raid_disks - conf->max_degraded; 3291 int stripe = data_disks * 3292 (mddev->chunk_size / PAGE_SIZE); 3293 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 3294 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 3295 } 3296 3297 /* Ok, everything is just fine now */ 3298 sysfs_create_group(&mddev->kobj, &raid5_attrs_group); 3299 3300 mddev->queue->unplug_fn = raid5_unplug_device; 3301 mddev->queue->issue_flush_fn = raid5_issue_flush; 3302 mddev->array_size = mddev->size * (conf->previous_raid_disks - 3303 conf->max_degraded); 3304 3305 return 0; 3306 abort: 3307 if (conf) { 3308 print_raid5_conf(conf); 3309 safe_put_page(conf->spare_page); 3310 kfree(conf->disks); 3311 kfree(conf->stripe_hashtbl); 3312 kfree(conf); 3313 } 3314 mddev->private = NULL; 3315 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev)); 3316 return -EIO; 3317 } 3318 3319 3320 3321 static int stop(mddev_t *mddev) 3322 { 3323 raid5_conf_t *conf = (raid5_conf_t *) mddev->private; 3324 3325 md_unregister_thread(mddev->thread); 3326 mddev->thread = NULL; 3327 shrink_stripes(conf); 3328 kfree(conf->stripe_hashtbl); 3329 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 3330 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); 3331 kfree(conf->disks); 3332 kfree(conf); 3333 mddev->private = NULL; 3334 return 0; 3335 } 3336 3337 #if RAID5_DEBUG 3338 static void print_sh (struct seq_file *seq, struct stripe_head *sh) 3339 { 3340 int i; 3341 3342 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", 3343 (unsigned long long)sh->sector, sh->pd_idx, sh->state); 3344 seq_printf(seq, "sh %llu, count %d.\n", 3345 (unsigned long long)sh->sector, atomic_read(&sh->count)); 3346 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); 3347 for (i = 0; i < sh->disks; i++) { 3348 seq_printf(seq, "(cache%d: %p %ld) ", 3349 i, sh->dev[i].page, sh->dev[i].flags); 3350 } 3351 seq_printf(seq, "\n"); 3352 } 3353 3354 static void printall (struct seq_file *seq, raid5_conf_t *conf) 3355 { 3356 struct stripe_head *sh; 3357 struct hlist_node *hn; 3358 int i; 3359 3360 spin_lock_irq(&conf->device_lock); 3361 for (i = 0; i < NR_HASH; i++) { 3362 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { 3363 if (sh->raid_conf != conf) 3364 continue; 3365 print_sh(seq, sh); 3366 } 3367 } 3368 spin_unlock_irq(&conf->device_lock); 3369 } 3370 #endif 3371 3372 static void status (struct seq_file *seq, mddev_t *mddev) 3373 { 3374 raid5_conf_t *conf = (raid5_conf_t *) mddev->private; 3375 int i; 3376 3377 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout); 3378 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); 3379 for (i = 0; i < conf->raid_disks; i++) 3380 seq_printf (seq, "%s", 3381 conf->disks[i].rdev && 3382 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 3383 seq_printf (seq, "]"); 3384 #if RAID5_DEBUG 3385 seq_printf (seq, "\n"); 3386 printall(seq, conf); 3387 #endif 3388 } 3389 3390 static void print_raid5_conf (raid5_conf_t *conf) 3391 { 3392 int i; 3393 struct disk_info *tmp; 3394 3395 printk("RAID5 conf printout:\n"); 3396 if (!conf) { 3397 printk("(conf==NULL)\n"); 3398 return; 3399 } 3400 printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks, 3401 conf->working_disks, conf->failed_disks); 3402 3403 for (i = 0; i < conf->raid_disks; i++) { 3404 char b[BDEVNAME_SIZE]; 3405 tmp = conf->disks + i; 3406 if (tmp->rdev) 3407 printk(" disk %d, o:%d, dev:%s\n", 3408 i, !test_bit(Faulty, &tmp->rdev->flags), 3409 bdevname(tmp->rdev->bdev,b)); 3410 } 3411 } 3412 3413 static int raid5_spare_active(mddev_t *mddev) 3414 { 3415 int i; 3416 raid5_conf_t *conf = mddev->private; 3417 struct disk_info *tmp; 3418 3419 for (i = 0; i < conf->raid_disks; i++) { 3420 tmp = conf->disks + i; 3421 if (tmp->rdev 3422 && !test_bit(Faulty, &tmp->rdev->flags) 3423 && !test_bit(In_sync, &tmp->rdev->flags)) { 3424 mddev->degraded--; 3425 conf->failed_disks--; 3426 conf->working_disks++; 3427 set_bit(In_sync, &tmp->rdev->flags); 3428 } 3429 } 3430 print_raid5_conf(conf); 3431 return 0; 3432 } 3433 3434 static int raid5_remove_disk(mddev_t *mddev, int number) 3435 { 3436 raid5_conf_t *conf = mddev->private; 3437 int err = 0; 3438 mdk_rdev_t *rdev; 3439 struct disk_info *p = conf->disks + number; 3440 3441 print_raid5_conf(conf); 3442 rdev = p->rdev; 3443 if (rdev) { 3444 if (test_bit(In_sync, &rdev->flags) || 3445 atomic_read(&rdev->nr_pending)) { 3446 err = -EBUSY; 3447 goto abort; 3448 } 3449 p->rdev = NULL; 3450 synchronize_rcu(); 3451 if (atomic_read(&rdev->nr_pending)) { 3452 /* lost the race, try later */ 3453 err = -EBUSY; 3454 p->rdev = rdev; 3455 } 3456 } 3457 abort: 3458 3459 print_raid5_conf(conf); 3460 return err; 3461 } 3462 3463 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) 3464 { 3465 raid5_conf_t *conf = mddev->private; 3466 int found = 0; 3467 int disk; 3468 struct disk_info *p; 3469 3470 if (mddev->degraded > conf->max_degraded) 3471 /* no point adding a device */ 3472 return 0; 3473 3474 /* 3475 * find the disk ... but prefer rdev->saved_raid_disk 3476 * if possible. 3477 */ 3478 if (rdev->saved_raid_disk >= 0 && 3479 conf->disks[rdev->saved_raid_disk].rdev == NULL) 3480 disk = rdev->saved_raid_disk; 3481 else 3482 disk = 0; 3483 for ( ; disk < conf->raid_disks; disk++) 3484 if ((p=conf->disks + disk)->rdev == NULL) { 3485 clear_bit(In_sync, &rdev->flags); 3486 rdev->raid_disk = disk; 3487 found = 1; 3488 if (rdev->saved_raid_disk != disk) 3489 conf->fullsync = 1; 3490 rcu_assign_pointer(p->rdev, rdev); 3491 break; 3492 } 3493 print_raid5_conf(conf); 3494 return found; 3495 } 3496 3497 static int raid5_resize(mddev_t *mddev, sector_t sectors) 3498 { 3499 /* no resync is happening, and there is enough space 3500 * on all devices, so we can resize. 3501 * We need to make sure resync covers any new space. 3502 * If the array is shrinking we should possibly wait until 3503 * any io in the removed space completes, but it hardly seems 3504 * worth it. 3505 */ 3506 raid5_conf_t *conf = mddev_to_conf(mddev); 3507 3508 sectors &= ~((sector_t)mddev->chunk_size/512 - 1); 3509 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1; 3510 set_capacity(mddev->gendisk, mddev->array_size << 1); 3511 mddev->changed = 1; 3512 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { 3513 mddev->recovery_cp = mddev->size << 1; 3514 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3515 } 3516 mddev->size = sectors /2; 3517 mddev->resync_max_sectors = sectors; 3518 return 0; 3519 } 3520 3521 #ifdef CONFIG_MD_RAID5_RESHAPE 3522 static int raid5_check_reshape(mddev_t *mddev) 3523 { 3524 raid5_conf_t *conf = mddev_to_conf(mddev); 3525 int err; 3526 3527 if (mddev->delta_disks < 0 || 3528 mddev->new_level != mddev->level) 3529 return -EINVAL; /* Cannot shrink array or change level yet */ 3530 if (mddev->delta_disks == 0) 3531 return 0; /* nothing to do */ 3532 3533 /* Can only proceed if there are plenty of stripe_heads. 3534 * We need a minimum of one full stripe,, and for sensible progress 3535 * it is best to have about 4 times that. 3536 * If we require 4 times, then the default 256 4K stripe_heads will 3537 * allow for chunk sizes up to 256K, which is probably OK. 3538 * If the chunk size is greater, user-space should request more 3539 * stripe_heads first. 3540 */ 3541 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes || 3542 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) { 3543 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", 3544 (mddev->chunk_size / STRIPE_SIZE)*4); 3545 return -ENOSPC; 3546 } 3547 3548 err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks); 3549 if (err) 3550 return err; 3551 3552 /* looks like we might be able to manage this */ 3553 return 0; 3554 } 3555 3556 static int raid5_start_reshape(mddev_t *mddev) 3557 { 3558 raid5_conf_t *conf = mddev_to_conf(mddev); 3559 mdk_rdev_t *rdev; 3560 struct list_head *rtmp; 3561 int spares = 0; 3562 int added_devices = 0; 3563 3564 if (mddev->degraded || 3565 test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 3566 return -EBUSY; 3567 3568 ITERATE_RDEV(mddev, rdev, rtmp) 3569 if (rdev->raid_disk < 0 && 3570 !test_bit(Faulty, &rdev->flags)) 3571 spares++; 3572 3573 if (spares < mddev->delta_disks-1) 3574 /* Not enough devices even to make a degraded array 3575 * of that size 3576 */ 3577 return -EINVAL; 3578 3579 atomic_set(&conf->reshape_stripes, 0); 3580 spin_lock_irq(&conf->device_lock); 3581 conf->previous_raid_disks = conf->raid_disks; 3582 conf->raid_disks += mddev->delta_disks; 3583 conf->expand_progress = 0; 3584 conf->expand_lo = 0; 3585 spin_unlock_irq(&conf->device_lock); 3586 3587 /* Add some new drives, as many as will fit. 3588 * We know there are enough to make the newly sized array work. 3589 */ 3590 ITERATE_RDEV(mddev, rdev, rtmp) 3591 if (rdev->raid_disk < 0 && 3592 !test_bit(Faulty, &rdev->flags)) { 3593 if (raid5_add_disk(mddev, rdev)) { 3594 char nm[20]; 3595 set_bit(In_sync, &rdev->flags); 3596 conf->working_disks++; 3597 added_devices++; 3598 rdev->recovery_offset = 0; 3599 sprintf(nm, "rd%d", rdev->raid_disk); 3600 sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); 3601 } else 3602 break; 3603 } 3604 3605 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices; 3606 mddev->raid_disks = conf->raid_disks; 3607 mddev->reshape_position = 0; 3608 mddev->sb_dirty = 1; 3609 3610 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 3611 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 3612 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 3613 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 3614 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 3615 "%s_reshape"); 3616 if (!mddev->sync_thread) { 3617 mddev->recovery = 0; 3618 spin_lock_irq(&conf->device_lock); 3619 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; 3620 conf->expand_progress = MaxSector; 3621 spin_unlock_irq(&conf->device_lock); 3622 return -EAGAIN; 3623 } 3624 md_wakeup_thread(mddev->sync_thread); 3625 md_new_event(mddev); 3626 return 0; 3627 } 3628 #endif 3629 3630 static void end_reshape(raid5_conf_t *conf) 3631 { 3632 struct block_device *bdev; 3633 3634 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { 3635 conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1); 3636 set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1); 3637 conf->mddev->changed = 1; 3638 3639 bdev = bdget_disk(conf->mddev->gendisk, 0); 3640 if (bdev) { 3641 mutex_lock(&bdev->bd_inode->i_mutex); 3642 i_size_write(bdev->bd_inode, conf->mddev->array_size << 10); 3643 mutex_unlock(&bdev->bd_inode->i_mutex); 3644 bdput(bdev); 3645 } 3646 spin_lock_irq(&conf->device_lock); 3647 conf->expand_progress = MaxSector; 3648 spin_unlock_irq(&conf->device_lock); 3649 conf->mddev->reshape_position = MaxSector; 3650 3651 /* read-ahead size must cover two whole stripes, which is 3652 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 3653 */ 3654 { 3655 int data_disks = conf->previous_raid_disks - conf->max_degraded; 3656 int stripe = data_disks * 3657 (conf->mddev->chunk_size / PAGE_SIZE); 3658 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 3659 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 3660 } 3661 } 3662 } 3663 3664 static void raid5_quiesce(mddev_t *mddev, int state) 3665 { 3666 raid5_conf_t *conf = mddev_to_conf(mddev); 3667 3668 switch(state) { 3669 case 2: /* resume for a suspend */ 3670 wake_up(&conf->wait_for_overlap); 3671 break; 3672 3673 case 1: /* stop all writes */ 3674 spin_lock_irq(&conf->device_lock); 3675 conf->quiesce = 1; 3676 wait_event_lock_irq(conf->wait_for_stripe, 3677 atomic_read(&conf->active_stripes) == 0, 3678 conf->device_lock, /* nothing */); 3679 spin_unlock_irq(&conf->device_lock); 3680 break; 3681 3682 case 0: /* re-enable writes */ 3683 spin_lock_irq(&conf->device_lock); 3684 conf->quiesce = 0; 3685 wake_up(&conf->wait_for_stripe); 3686 wake_up(&conf->wait_for_overlap); 3687 spin_unlock_irq(&conf->device_lock); 3688 break; 3689 } 3690 } 3691 3692 static struct mdk_personality raid6_personality = 3693 { 3694 .name = "raid6", 3695 .level = 6, 3696 .owner = THIS_MODULE, 3697 .make_request = make_request, 3698 .run = run, 3699 .stop = stop, 3700 .status = status, 3701 .error_handler = error, 3702 .hot_add_disk = raid5_add_disk, 3703 .hot_remove_disk= raid5_remove_disk, 3704 .spare_active = raid5_spare_active, 3705 .sync_request = sync_request, 3706 .resize = raid5_resize, 3707 .quiesce = raid5_quiesce, 3708 }; 3709 static struct mdk_personality raid5_personality = 3710 { 3711 .name = "raid5", 3712 .level = 5, 3713 .owner = THIS_MODULE, 3714 .make_request = make_request, 3715 .run = run, 3716 .stop = stop, 3717 .status = status, 3718 .error_handler = error, 3719 .hot_add_disk = raid5_add_disk, 3720 .hot_remove_disk= raid5_remove_disk, 3721 .spare_active = raid5_spare_active, 3722 .sync_request = sync_request, 3723 .resize = raid5_resize, 3724 #ifdef CONFIG_MD_RAID5_RESHAPE 3725 .check_reshape = raid5_check_reshape, 3726 .start_reshape = raid5_start_reshape, 3727 #endif 3728 .quiesce = raid5_quiesce, 3729 }; 3730 3731 static struct mdk_personality raid4_personality = 3732 { 3733 .name = "raid4", 3734 .level = 4, 3735 .owner = THIS_MODULE, 3736 .make_request = make_request, 3737 .run = run, 3738 .stop = stop, 3739 .status = status, 3740 .error_handler = error, 3741 .hot_add_disk = raid5_add_disk, 3742 .hot_remove_disk= raid5_remove_disk, 3743 .spare_active = raid5_spare_active, 3744 .sync_request = sync_request, 3745 .resize = raid5_resize, 3746 .quiesce = raid5_quiesce, 3747 }; 3748 3749 static int __init raid5_init(void) 3750 { 3751 int e; 3752 3753 e = raid6_select_algo(); 3754 if ( e ) 3755 return e; 3756 register_md_personality(&raid6_personality); 3757 register_md_personality(&raid5_personality); 3758 register_md_personality(&raid4_personality); 3759 return 0; 3760 } 3761 3762 static void raid5_exit(void) 3763 { 3764 unregister_md_personality(&raid6_personality); 3765 unregister_md_personality(&raid5_personality); 3766 unregister_md_personality(&raid4_personality); 3767 } 3768 3769 module_init(raid5_init); 3770 module_exit(raid5_exit); 3771 MODULE_LICENSE("GPL"); 3772 MODULE_ALIAS("md-personality-4"); /* RAID5 */ 3773 MODULE_ALIAS("md-raid5"); 3774 MODULE_ALIAS("md-raid4"); 3775 MODULE_ALIAS("md-level-5"); 3776 MODULE_ALIAS("md-level-4"); 3777 MODULE_ALIAS("md-personality-8"); /* RAID6 */ 3778 MODULE_ALIAS("md-raid6"); 3779 MODULE_ALIAS("md-level-6"); 3780 3781 /* This used to be two separate modules, they were: */ 3782 MODULE_ALIAS("raid5"); 3783 MODULE_ALIAS("raid6"); 3784