raid5.c revision 671488cc25f7c194c7c7a9f258bab1df17a6ff69
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->seq_write is the number of the last batch successfully written. 31 * conf->seq_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 seq_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/blkdev.h> 47#include <linux/kthread.h> 48#include <linux/raid/pq.h> 49#include <linux/async_tx.h> 50#include <linux/module.h> 51#include <linux/async.h> 52#include <linux/seq_file.h> 53#include <linux/cpu.h> 54#include <linux/slab.h> 55#include <linux/ratelimit.h> 56#include "md.h" 57#include "raid5.h" 58#include "raid0.h" 59#include "bitmap.h" 60 61/* 62 * Stripe cache 63 */ 64 65#define NR_STRIPES 256 66#define STRIPE_SIZE PAGE_SIZE 67#define STRIPE_SHIFT (PAGE_SHIFT - 9) 68#define STRIPE_SECTORS (STRIPE_SIZE>>9) 69#define IO_THRESHOLD 1 70#define BYPASS_THRESHOLD 1 71#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) 72#define HASH_MASK (NR_HASH - 1) 73 74static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect) 75{ 76 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK; 77 return &conf->stripe_hashtbl[hash]; 78} 79 80/* bio's attached to a stripe+device for I/O are linked together in bi_sector 81 * order without overlap. There may be several bio's per stripe+device, and 82 * a bio could span several devices. 83 * When walking this list for a particular stripe+device, we must never proceed 84 * beyond a bio that extends past this device, as the next bio might no longer 85 * be valid. 86 * This function is used to determine the 'next' bio in the list, given the sector 87 * of the current stripe+device 88 */ 89static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector) 90{ 91 int sectors = bio->bi_size >> 9; 92 if (bio->bi_sector + sectors < sector + STRIPE_SECTORS) 93 return bio->bi_next; 94 else 95 return NULL; 96} 97 98/* 99 * We maintain a biased count of active stripes in the bottom 16 bits of 100 * bi_phys_segments, and a count of processed stripes in the upper 16 bits 101 */ 102static inline int raid5_bi_phys_segments(struct bio *bio) 103{ 104 return bio->bi_phys_segments & 0xffff; 105} 106 107static inline int raid5_bi_hw_segments(struct bio *bio) 108{ 109 return (bio->bi_phys_segments >> 16) & 0xffff; 110} 111 112static inline int raid5_dec_bi_phys_segments(struct bio *bio) 113{ 114 --bio->bi_phys_segments; 115 return raid5_bi_phys_segments(bio); 116} 117 118static inline int raid5_dec_bi_hw_segments(struct bio *bio) 119{ 120 unsigned short val = raid5_bi_hw_segments(bio); 121 122 --val; 123 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); 124 return val; 125} 126 127static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) 128{ 129 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16); 130} 131 132/* Find first data disk in a raid6 stripe */ 133static inline int raid6_d0(struct stripe_head *sh) 134{ 135 if (sh->ddf_layout) 136 /* ddf always start from first device */ 137 return 0; 138 /* md starts just after Q block */ 139 if (sh->qd_idx == sh->disks - 1) 140 return 0; 141 else 142 return sh->qd_idx + 1; 143} 144static inline int raid6_next_disk(int disk, int raid_disks) 145{ 146 disk++; 147 return (disk < raid_disks) ? disk : 0; 148} 149 150/* When walking through the disks in a raid5, starting at raid6_d0, 151 * We need to map each disk to a 'slot', where the data disks are slot 152 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk 153 * is raid_disks-1. This help does that mapping. 154 */ 155static int raid6_idx_to_slot(int idx, struct stripe_head *sh, 156 int *count, int syndrome_disks) 157{ 158 int slot = *count; 159 160 if (sh->ddf_layout) 161 (*count)++; 162 if (idx == sh->pd_idx) 163 return syndrome_disks; 164 if (idx == sh->qd_idx) 165 return syndrome_disks + 1; 166 if (!sh->ddf_layout) 167 (*count)++; 168 return slot; 169} 170 171static void return_io(struct bio *return_bi) 172{ 173 struct bio *bi = return_bi; 174 while (bi) { 175 176 return_bi = bi->bi_next; 177 bi->bi_next = NULL; 178 bi->bi_size = 0; 179 bio_endio(bi, 0); 180 bi = return_bi; 181 } 182} 183 184static void print_raid5_conf (struct r5conf *conf); 185 186static int stripe_operations_active(struct stripe_head *sh) 187{ 188 return sh->check_state || sh->reconstruct_state || 189 test_bit(STRIPE_BIOFILL_RUN, &sh->state) || 190 test_bit(STRIPE_COMPUTE_RUN, &sh->state); 191} 192 193static void __release_stripe(struct r5conf *conf, struct stripe_head *sh) 194{ 195 if (atomic_dec_and_test(&sh->count)) { 196 BUG_ON(!list_empty(&sh->lru)); 197 BUG_ON(atomic_read(&conf->active_stripes)==0); 198 if (test_bit(STRIPE_HANDLE, &sh->state)) { 199 if (test_bit(STRIPE_DELAYED, &sh->state)) 200 list_add_tail(&sh->lru, &conf->delayed_list); 201 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && 202 sh->bm_seq - conf->seq_write > 0) 203 list_add_tail(&sh->lru, &conf->bitmap_list); 204 else { 205 clear_bit(STRIPE_BIT_DELAY, &sh->state); 206 list_add_tail(&sh->lru, &conf->handle_list); 207 } 208 md_wakeup_thread(conf->mddev->thread); 209 } else { 210 BUG_ON(stripe_operations_active(sh)); 211 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 212 atomic_dec(&conf->preread_active_stripes); 213 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 214 md_wakeup_thread(conf->mddev->thread); 215 } 216 atomic_dec(&conf->active_stripes); 217 if (!test_bit(STRIPE_EXPANDING, &sh->state)) { 218 list_add_tail(&sh->lru, &conf->inactive_list); 219 wake_up(&conf->wait_for_stripe); 220 if (conf->retry_read_aligned) 221 md_wakeup_thread(conf->mddev->thread); 222 } 223 } 224 } 225} 226 227static void release_stripe(struct stripe_head *sh) 228{ 229 struct r5conf *conf = sh->raid_conf; 230 unsigned long flags; 231 232 spin_lock_irqsave(&conf->device_lock, flags); 233 __release_stripe(conf, sh); 234 spin_unlock_irqrestore(&conf->device_lock, flags); 235} 236 237static inline void remove_hash(struct stripe_head *sh) 238{ 239 pr_debug("remove_hash(), stripe %llu\n", 240 (unsigned long long)sh->sector); 241 242 hlist_del_init(&sh->hash); 243} 244 245static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh) 246{ 247 struct hlist_head *hp = stripe_hash(conf, sh->sector); 248 249 pr_debug("insert_hash(), stripe %llu\n", 250 (unsigned long long)sh->sector); 251 252 hlist_add_head(&sh->hash, hp); 253} 254 255 256/* find an idle stripe, make sure it is unhashed, and return it. */ 257static struct stripe_head *get_free_stripe(struct r5conf *conf) 258{ 259 struct stripe_head *sh = NULL; 260 struct list_head *first; 261 262 if (list_empty(&conf->inactive_list)) 263 goto out; 264 first = conf->inactive_list.next; 265 sh = list_entry(first, struct stripe_head, lru); 266 list_del_init(first); 267 remove_hash(sh); 268 atomic_inc(&conf->active_stripes); 269out: 270 return sh; 271} 272 273static void shrink_buffers(struct stripe_head *sh) 274{ 275 struct page *p; 276 int i; 277 int num = sh->raid_conf->pool_size; 278 279 for (i = 0; i < num ; i++) { 280 p = sh->dev[i].page; 281 if (!p) 282 continue; 283 sh->dev[i].page = NULL; 284 put_page(p); 285 } 286} 287 288static int grow_buffers(struct stripe_head *sh) 289{ 290 int i; 291 int num = sh->raid_conf->pool_size; 292 293 for (i = 0; i < num; i++) { 294 struct page *page; 295 296 if (!(page = alloc_page(GFP_KERNEL))) { 297 return 1; 298 } 299 sh->dev[i].page = page; 300 } 301 return 0; 302} 303 304static void raid5_build_block(struct stripe_head *sh, int i, int previous); 305static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, 306 struct stripe_head *sh); 307 308static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) 309{ 310 struct r5conf *conf = sh->raid_conf; 311 int i; 312 313 BUG_ON(atomic_read(&sh->count) != 0); 314 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); 315 BUG_ON(stripe_operations_active(sh)); 316 317 pr_debug("init_stripe called, stripe %llu\n", 318 (unsigned long long)sh->sector); 319 320 remove_hash(sh); 321 322 sh->generation = conf->generation - previous; 323 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; 324 sh->sector = sector; 325 stripe_set_idx(sector, conf, previous, sh); 326 sh->state = 0; 327 328 329 for (i = sh->disks; i--; ) { 330 struct r5dev *dev = &sh->dev[i]; 331 332 if (dev->toread || dev->read || dev->towrite || dev->written || 333 test_bit(R5_LOCKED, &dev->flags)) { 334 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", 335 (unsigned long long)sh->sector, i, dev->toread, 336 dev->read, dev->towrite, dev->written, 337 test_bit(R5_LOCKED, &dev->flags)); 338 WARN_ON(1); 339 } 340 dev->flags = 0; 341 raid5_build_block(sh, i, previous); 342 } 343 insert_hash(conf, sh); 344} 345 346static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, 347 short generation) 348{ 349 struct stripe_head *sh; 350 struct hlist_node *hn; 351 352 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); 353 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) 354 if (sh->sector == sector && sh->generation == generation) 355 return sh; 356 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); 357 return NULL; 358} 359 360/* 361 * Need to check if array has failed when deciding whether to: 362 * - start an array 363 * - remove non-faulty devices 364 * - add a spare 365 * - allow a reshape 366 * This determination is simple when no reshape is happening. 367 * However if there is a reshape, we need to carefully check 368 * both the before and after sections. 369 * This is because some failed devices may only affect one 370 * of the two sections, and some non-in_sync devices may 371 * be insync in the section most affected by failed devices. 372 */ 373static int calc_degraded(struct r5conf *conf) 374{ 375 int degraded, degraded2; 376 int i; 377 378 rcu_read_lock(); 379 degraded = 0; 380 for (i = 0; i < conf->previous_raid_disks; i++) { 381 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); 382 if (!rdev || test_bit(Faulty, &rdev->flags)) 383 degraded++; 384 else if (test_bit(In_sync, &rdev->flags)) 385 ; 386 else 387 /* not in-sync or faulty. 388 * If the reshape increases the number of devices, 389 * this is being recovered by the reshape, so 390 * this 'previous' section is not in_sync. 391 * If the number of devices is being reduced however, 392 * the device can only be part of the array if 393 * we are reverting a reshape, so this section will 394 * be in-sync. 395 */ 396 if (conf->raid_disks >= conf->previous_raid_disks) 397 degraded++; 398 } 399 rcu_read_unlock(); 400 if (conf->raid_disks == conf->previous_raid_disks) 401 return degraded; 402 rcu_read_lock(); 403 degraded2 = 0; 404 for (i = 0; i < conf->raid_disks; i++) { 405 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); 406 if (!rdev || test_bit(Faulty, &rdev->flags)) 407 degraded2++; 408 else if (test_bit(In_sync, &rdev->flags)) 409 ; 410 else 411 /* not in-sync or faulty. 412 * If reshape increases the number of devices, this 413 * section has already been recovered, else it 414 * almost certainly hasn't. 415 */ 416 if (conf->raid_disks <= conf->previous_raid_disks) 417 degraded2++; 418 } 419 rcu_read_unlock(); 420 if (degraded2 > degraded) 421 return degraded2; 422 return degraded; 423} 424 425static int has_failed(struct r5conf *conf) 426{ 427 int degraded; 428 429 if (conf->mddev->reshape_position == MaxSector) 430 return conf->mddev->degraded > conf->max_degraded; 431 432 degraded = calc_degraded(conf); 433 if (degraded > conf->max_degraded) 434 return 1; 435 return 0; 436} 437 438static struct stripe_head * 439get_active_stripe(struct r5conf *conf, sector_t sector, 440 int previous, int noblock, int noquiesce) 441{ 442 struct stripe_head *sh; 443 444 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); 445 446 spin_lock_irq(&conf->device_lock); 447 448 do { 449 wait_event_lock_irq(conf->wait_for_stripe, 450 conf->quiesce == 0 || noquiesce, 451 conf->device_lock, /* nothing */); 452 sh = __find_stripe(conf, sector, conf->generation - previous); 453 if (!sh) { 454 if (!conf->inactive_blocked) 455 sh = get_free_stripe(conf); 456 if (noblock && sh == NULL) 457 break; 458 if (!sh) { 459 conf->inactive_blocked = 1; 460 wait_event_lock_irq(conf->wait_for_stripe, 461 !list_empty(&conf->inactive_list) && 462 (atomic_read(&conf->active_stripes) 463 < (conf->max_nr_stripes *3/4) 464 || !conf->inactive_blocked), 465 conf->device_lock, 466 ); 467 conf->inactive_blocked = 0; 468 } else 469 init_stripe(sh, sector, previous); 470 } else { 471 if (atomic_read(&sh->count)) { 472 BUG_ON(!list_empty(&sh->lru) 473 && !test_bit(STRIPE_EXPANDING, &sh->state)); 474 } else { 475 if (!test_bit(STRIPE_HANDLE, &sh->state)) 476 atomic_inc(&conf->active_stripes); 477 if (list_empty(&sh->lru) && 478 !test_bit(STRIPE_EXPANDING, &sh->state)) 479 BUG(); 480 list_del_init(&sh->lru); 481 } 482 } 483 } while (sh == NULL); 484 485 if (sh) 486 atomic_inc(&sh->count); 487 488 spin_unlock_irq(&conf->device_lock); 489 return sh; 490} 491 492static void 493raid5_end_read_request(struct bio *bi, int error); 494static void 495raid5_end_write_request(struct bio *bi, int error); 496 497static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 498{ 499 struct r5conf *conf = sh->raid_conf; 500 int i, disks = sh->disks; 501 502 might_sleep(); 503 504 for (i = disks; i--; ) { 505 int rw; 506 struct bio *bi; 507 struct md_rdev *rdev; 508 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { 509 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) 510 rw = WRITE_FUA; 511 else 512 rw = WRITE; 513 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 514 rw = READ; 515 else 516 continue; 517 518 bi = &sh->dev[i].req; 519 520 bi->bi_rw = rw; 521 if (rw & WRITE) 522 bi->bi_end_io = raid5_end_write_request; 523 else 524 bi->bi_end_io = raid5_end_read_request; 525 526 rcu_read_lock(); 527 rdev = rcu_dereference(conf->disks[i].rdev); 528 if (rdev && test_bit(Faulty, &rdev->flags)) 529 rdev = NULL; 530 if (rdev) 531 atomic_inc(&rdev->nr_pending); 532 rcu_read_unlock(); 533 534 /* We have already checked bad blocks for reads. Now 535 * need to check for writes. 536 */ 537 while ((rw & WRITE) && rdev && 538 test_bit(WriteErrorSeen, &rdev->flags)) { 539 sector_t first_bad; 540 int bad_sectors; 541 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 542 &first_bad, &bad_sectors); 543 if (!bad) 544 break; 545 546 if (bad < 0) { 547 set_bit(BlockedBadBlocks, &rdev->flags); 548 if (!conf->mddev->external && 549 conf->mddev->flags) { 550 /* It is very unlikely, but we might 551 * still need to write out the 552 * bad block log - better give it 553 * a chance*/ 554 md_check_recovery(conf->mddev); 555 } 556 md_wait_for_blocked_rdev(rdev, conf->mddev); 557 } else { 558 /* Acknowledged bad block - skip the write */ 559 rdev_dec_pending(rdev, conf->mddev); 560 rdev = NULL; 561 } 562 } 563 564 if (rdev) { 565 if (s->syncing || s->expanding || s->expanded) 566 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 567 568 set_bit(STRIPE_IO_STARTED, &sh->state); 569 570 bi->bi_bdev = rdev->bdev; 571 pr_debug("%s: for %llu schedule op %ld on disc %d\n", 572 __func__, (unsigned long long)sh->sector, 573 bi->bi_rw, i); 574 atomic_inc(&sh->count); 575 bi->bi_sector = sh->sector + rdev->data_offset; 576 bi->bi_flags = 1 << BIO_UPTODATE; 577 bi->bi_vcnt = 1; 578 bi->bi_max_vecs = 1; 579 bi->bi_idx = 0; 580 bi->bi_io_vec = &sh->dev[i].vec; 581 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 582 bi->bi_io_vec[0].bv_offset = 0; 583 bi->bi_size = STRIPE_SIZE; 584 bi->bi_next = NULL; 585 generic_make_request(bi); 586 } else { 587 if (rw & WRITE) 588 set_bit(STRIPE_DEGRADED, &sh->state); 589 pr_debug("skip op %ld on disc %d for sector %llu\n", 590 bi->bi_rw, i, (unsigned long long)sh->sector); 591 clear_bit(R5_LOCKED, &sh->dev[i].flags); 592 set_bit(STRIPE_HANDLE, &sh->state); 593 } 594 } 595} 596 597static struct dma_async_tx_descriptor * 598async_copy_data(int frombio, struct bio *bio, struct page *page, 599 sector_t sector, struct dma_async_tx_descriptor *tx) 600{ 601 struct bio_vec *bvl; 602 struct page *bio_page; 603 int i; 604 int page_offset; 605 struct async_submit_ctl submit; 606 enum async_tx_flags flags = 0; 607 608 if (bio->bi_sector >= sector) 609 page_offset = (signed)(bio->bi_sector - sector) * 512; 610 else 611 page_offset = (signed)(sector - bio->bi_sector) * -512; 612 613 if (frombio) 614 flags |= ASYNC_TX_FENCE; 615 init_async_submit(&submit, flags, tx, NULL, NULL, NULL); 616 617 bio_for_each_segment(bvl, bio, i) { 618 int len = bvl->bv_len; 619 int clen; 620 int b_offset = 0; 621 622 if (page_offset < 0) { 623 b_offset = -page_offset; 624 page_offset += b_offset; 625 len -= b_offset; 626 } 627 628 if (len > 0 && page_offset + len > STRIPE_SIZE) 629 clen = STRIPE_SIZE - page_offset; 630 else 631 clen = len; 632 633 if (clen > 0) { 634 b_offset += bvl->bv_offset; 635 bio_page = bvl->bv_page; 636 if (frombio) 637 tx = async_memcpy(page, bio_page, page_offset, 638 b_offset, clen, &submit); 639 else 640 tx = async_memcpy(bio_page, page, b_offset, 641 page_offset, clen, &submit); 642 } 643 /* chain the operations */ 644 submit.depend_tx = tx; 645 646 if (clen < len) /* hit end of page */ 647 break; 648 page_offset += len; 649 } 650 651 return tx; 652} 653 654static void ops_complete_biofill(void *stripe_head_ref) 655{ 656 struct stripe_head *sh = stripe_head_ref; 657 struct bio *return_bi = NULL; 658 struct r5conf *conf = sh->raid_conf; 659 int i; 660 661 pr_debug("%s: stripe %llu\n", __func__, 662 (unsigned long long)sh->sector); 663 664 /* clear completed biofills */ 665 spin_lock_irq(&conf->device_lock); 666 for (i = sh->disks; i--; ) { 667 struct r5dev *dev = &sh->dev[i]; 668 669 /* acknowledge completion of a biofill operation */ 670 /* and check if we need to reply to a read request, 671 * new R5_Wantfill requests are held off until 672 * !STRIPE_BIOFILL_RUN 673 */ 674 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { 675 struct bio *rbi, *rbi2; 676 677 BUG_ON(!dev->read); 678 rbi = dev->read; 679 dev->read = NULL; 680 while (rbi && rbi->bi_sector < 681 dev->sector + STRIPE_SECTORS) { 682 rbi2 = r5_next_bio(rbi, dev->sector); 683 if (!raid5_dec_bi_phys_segments(rbi)) { 684 rbi->bi_next = return_bi; 685 return_bi = rbi; 686 } 687 rbi = rbi2; 688 } 689 } 690 } 691 spin_unlock_irq(&conf->device_lock); 692 clear_bit(STRIPE_BIOFILL_RUN, &sh->state); 693 694 return_io(return_bi); 695 696 set_bit(STRIPE_HANDLE, &sh->state); 697 release_stripe(sh); 698} 699 700static void ops_run_biofill(struct stripe_head *sh) 701{ 702 struct dma_async_tx_descriptor *tx = NULL; 703 struct r5conf *conf = sh->raid_conf; 704 struct async_submit_ctl submit; 705 int i; 706 707 pr_debug("%s: stripe %llu\n", __func__, 708 (unsigned long long)sh->sector); 709 710 for (i = sh->disks; i--; ) { 711 struct r5dev *dev = &sh->dev[i]; 712 if (test_bit(R5_Wantfill, &dev->flags)) { 713 struct bio *rbi; 714 spin_lock_irq(&conf->device_lock); 715 dev->read = rbi = dev->toread; 716 dev->toread = NULL; 717 spin_unlock_irq(&conf->device_lock); 718 while (rbi && rbi->bi_sector < 719 dev->sector + STRIPE_SECTORS) { 720 tx = async_copy_data(0, rbi, dev->page, 721 dev->sector, tx); 722 rbi = r5_next_bio(rbi, dev->sector); 723 } 724 } 725 } 726 727 atomic_inc(&sh->count); 728 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); 729 async_trigger_callback(&submit); 730} 731 732static void mark_target_uptodate(struct stripe_head *sh, int target) 733{ 734 struct r5dev *tgt; 735 736 if (target < 0) 737 return; 738 739 tgt = &sh->dev[target]; 740 set_bit(R5_UPTODATE, &tgt->flags); 741 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 742 clear_bit(R5_Wantcompute, &tgt->flags); 743} 744 745static void ops_complete_compute(void *stripe_head_ref) 746{ 747 struct stripe_head *sh = stripe_head_ref; 748 749 pr_debug("%s: stripe %llu\n", __func__, 750 (unsigned long long)sh->sector); 751 752 /* mark the computed target(s) as uptodate */ 753 mark_target_uptodate(sh, sh->ops.target); 754 mark_target_uptodate(sh, sh->ops.target2); 755 756 clear_bit(STRIPE_COMPUTE_RUN, &sh->state); 757 if (sh->check_state == check_state_compute_run) 758 sh->check_state = check_state_compute_result; 759 set_bit(STRIPE_HANDLE, &sh->state); 760 release_stripe(sh); 761} 762 763/* return a pointer to the address conversion region of the scribble buffer */ 764static addr_conv_t *to_addr_conv(struct stripe_head *sh, 765 struct raid5_percpu *percpu) 766{ 767 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); 768} 769 770static struct dma_async_tx_descriptor * 771ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 772{ 773 int disks = sh->disks; 774 struct page **xor_srcs = percpu->scribble; 775 int target = sh->ops.target; 776 struct r5dev *tgt = &sh->dev[target]; 777 struct page *xor_dest = tgt->page; 778 int count = 0; 779 struct dma_async_tx_descriptor *tx; 780 struct async_submit_ctl submit; 781 int i; 782 783 pr_debug("%s: stripe %llu block: %d\n", 784 __func__, (unsigned long long)sh->sector, target); 785 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 786 787 for (i = disks; i--; ) 788 if (i != target) 789 xor_srcs[count++] = sh->dev[i].page; 790 791 atomic_inc(&sh->count); 792 793 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, 794 ops_complete_compute, sh, to_addr_conv(sh, percpu)); 795 if (unlikely(count == 1)) 796 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 797 else 798 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 799 800 return tx; 801} 802 803/* set_syndrome_sources - populate source buffers for gen_syndrome 804 * @srcs - (struct page *) array of size sh->disks 805 * @sh - stripe_head to parse 806 * 807 * Populates srcs in proper layout order for the stripe and returns the 808 * 'count' of sources to be used in a call to async_gen_syndrome. The P 809 * destination buffer is recorded in srcs[count] and the Q destination 810 * is recorded in srcs[count+1]]. 811 */ 812static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) 813{ 814 int disks = sh->disks; 815 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); 816 int d0_idx = raid6_d0(sh); 817 int count; 818 int i; 819 820 for (i = 0; i < disks; i++) 821 srcs[i] = NULL; 822 823 count = 0; 824 i = d0_idx; 825 do { 826 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 827 828 srcs[slot] = sh->dev[i].page; 829 i = raid6_next_disk(i, disks); 830 } while (i != d0_idx); 831 832 return syndrome_disks; 833} 834 835static struct dma_async_tx_descriptor * 836ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) 837{ 838 int disks = sh->disks; 839 struct page **blocks = percpu->scribble; 840 int target; 841 int qd_idx = sh->qd_idx; 842 struct dma_async_tx_descriptor *tx; 843 struct async_submit_ctl submit; 844 struct r5dev *tgt; 845 struct page *dest; 846 int i; 847 int count; 848 849 if (sh->ops.target < 0) 850 target = sh->ops.target2; 851 else if (sh->ops.target2 < 0) 852 target = sh->ops.target; 853 else 854 /* we should only have one valid target */ 855 BUG(); 856 BUG_ON(target < 0); 857 pr_debug("%s: stripe %llu block: %d\n", 858 __func__, (unsigned long long)sh->sector, target); 859 860 tgt = &sh->dev[target]; 861 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 862 dest = tgt->page; 863 864 atomic_inc(&sh->count); 865 866 if (target == qd_idx) { 867 count = set_syndrome_sources(blocks, sh); 868 blocks[count] = NULL; /* regenerating p is not necessary */ 869 BUG_ON(blocks[count+1] != dest); /* q should already be set */ 870 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 871 ops_complete_compute, sh, 872 to_addr_conv(sh, percpu)); 873 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 874 } else { 875 /* Compute any data- or p-drive using XOR */ 876 count = 0; 877 for (i = disks; i-- ; ) { 878 if (i == target || i == qd_idx) 879 continue; 880 blocks[count++] = sh->dev[i].page; 881 } 882 883 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 884 NULL, ops_complete_compute, sh, 885 to_addr_conv(sh, percpu)); 886 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); 887 } 888 889 return tx; 890} 891 892static struct dma_async_tx_descriptor * 893ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) 894{ 895 int i, count, disks = sh->disks; 896 int syndrome_disks = sh->ddf_layout ? disks : disks-2; 897 int d0_idx = raid6_d0(sh); 898 int faila = -1, failb = -1; 899 int target = sh->ops.target; 900 int target2 = sh->ops.target2; 901 struct r5dev *tgt = &sh->dev[target]; 902 struct r5dev *tgt2 = &sh->dev[target2]; 903 struct dma_async_tx_descriptor *tx; 904 struct page **blocks = percpu->scribble; 905 struct async_submit_ctl submit; 906 907 pr_debug("%s: stripe %llu block1: %d block2: %d\n", 908 __func__, (unsigned long long)sh->sector, target, target2); 909 BUG_ON(target < 0 || target2 < 0); 910 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 911 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); 912 913 /* we need to open-code set_syndrome_sources to handle the 914 * slot number conversion for 'faila' and 'failb' 915 */ 916 for (i = 0; i < disks ; i++) 917 blocks[i] = NULL; 918 count = 0; 919 i = d0_idx; 920 do { 921 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 922 923 blocks[slot] = sh->dev[i].page; 924 925 if (i == target) 926 faila = slot; 927 if (i == target2) 928 failb = slot; 929 i = raid6_next_disk(i, disks); 930 } while (i != d0_idx); 931 932 BUG_ON(faila == failb); 933 if (failb < faila) 934 swap(faila, failb); 935 pr_debug("%s: stripe: %llu faila: %d failb: %d\n", 936 __func__, (unsigned long long)sh->sector, faila, failb); 937 938 atomic_inc(&sh->count); 939 940 if (failb == syndrome_disks+1) { 941 /* Q disk is one of the missing disks */ 942 if (faila == syndrome_disks) { 943 /* Missing P+Q, just recompute */ 944 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 945 ops_complete_compute, sh, 946 to_addr_conv(sh, percpu)); 947 return async_gen_syndrome(blocks, 0, syndrome_disks+2, 948 STRIPE_SIZE, &submit); 949 } else { 950 struct page *dest; 951 int data_target; 952 int qd_idx = sh->qd_idx; 953 954 /* Missing D+Q: recompute D from P, then recompute Q */ 955 if (target == qd_idx) 956 data_target = target2; 957 else 958 data_target = target; 959 960 count = 0; 961 for (i = disks; i-- ; ) { 962 if (i == data_target || i == qd_idx) 963 continue; 964 blocks[count++] = sh->dev[i].page; 965 } 966 dest = sh->dev[data_target].page; 967 init_async_submit(&submit, 968 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 969 NULL, NULL, NULL, 970 to_addr_conv(sh, percpu)); 971 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, 972 &submit); 973 974 count = set_syndrome_sources(blocks, sh); 975 init_async_submit(&submit, ASYNC_TX_FENCE, tx, 976 ops_complete_compute, sh, 977 to_addr_conv(sh, percpu)); 978 return async_gen_syndrome(blocks, 0, count+2, 979 STRIPE_SIZE, &submit); 980 } 981 } else { 982 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 983 ops_complete_compute, sh, 984 to_addr_conv(sh, percpu)); 985 if (failb == syndrome_disks) { 986 /* We're missing D+P. */ 987 return async_raid6_datap_recov(syndrome_disks+2, 988 STRIPE_SIZE, faila, 989 blocks, &submit); 990 } else { 991 /* We're missing D+D. */ 992 return async_raid6_2data_recov(syndrome_disks+2, 993 STRIPE_SIZE, faila, failb, 994 blocks, &submit); 995 } 996 } 997} 998 999 1000static void ops_complete_prexor(void *stripe_head_ref) 1001{ 1002 struct stripe_head *sh = stripe_head_ref; 1003 1004 pr_debug("%s: stripe %llu\n", __func__, 1005 (unsigned long long)sh->sector); 1006} 1007 1008static struct dma_async_tx_descriptor * 1009ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu, 1010 struct dma_async_tx_descriptor *tx) 1011{ 1012 int disks = sh->disks; 1013 struct page **xor_srcs = percpu->scribble; 1014 int count = 0, pd_idx = sh->pd_idx, i; 1015 struct async_submit_ctl submit; 1016 1017 /* existing parity data subtracted */ 1018 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1019 1020 pr_debug("%s: stripe %llu\n", __func__, 1021 (unsigned long long)sh->sector); 1022 1023 for (i = disks; i--; ) { 1024 struct r5dev *dev = &sh->dev[i]; 1025 /* Only process blocks that are known to be uptodate */ 1026 if (test_bit(R5_Wantdrain, &dev->flags)) 1027 xor_srcs[count++] = dev->page; 1028 } 1029 1030 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, 1031 ops_complete_prexor, sh, to_addr_conv(sh, percpu)); 1032 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1033 1034 return tx; 1035} 1036 1037static struct dma_async_tx_descriptor * 1038ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 1039{ 1040 int disks = sh->disks; 1041 int i; 1042 1043 pr_debug("%s: stripe %llu\n", __func__, 1044 (unsigned long long)sh->sector); 1045 1046 for (i = disks; i--; ) { 1047 struct r5dev *dev = &sh->dev[i]; 1048 struct bio *chosen; 1049 1050 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { 1051 struct bio *wbi; 1052 1053 spin_lock_irq(&sh->raid_conf->device_lock); 1054 chosen = dev->towrite; 1055 dev->towrite = NULL; 1056 BUG_ON(dev->written); 1057 wbi = dev->written = chosen; 1058 spin_unlock_irq(&sh->raid_conf->device_lock); 1059 1060 while (wbi && wbi->bi_sector < 1061 dev->sector + STRIPE_SECTORS) { 1062 if (wbi->bi_rw & REQ_FUA) 1063 set_bit(R5_WantFUA, &dev->flags); 1064 tx = async_copy_data(1, wbi, dev->page, 1065 dev->sector, tx); 1066 wbi = r5_next_bio(wbi, dev->sector); 1067 } 1068 } 1069 } 1070 1071 return tx; 1072} 1073 1074static void ops_complete_reconstruct(void *stripe_head_ref) 1075{ 1076 struct stripe_head *sh = stripe_head_ref; 1077 int disks = sh->disks; 1078 int pd_idx = sh->pd_idx; 1079 int qd_idx = sh->qd_idx; 1080 int i; 1081 bool fua = false; 1082 1083 pr_debug("%s: stripe %llu\n", __func__, 1084 (unsigned long long)sh->sector); 1085 1086 for (i = disks; i--; ) 1087 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); 1088 1089 for (i = disks; i--; ) { 1090 struct r5dev *dev = &sh->dev[i]; 1091 1092 if (dev->written || i == pd_idx || i == qd_idx) { 1093 set_bit(R5_UPTODATE, &dev->flags); 1094 if (fua) 1095 set_bit(R5_WantFUA, &dev->flags); 1096 } 1097 } 1098 1099 if (sh->reconstruct_state == reconstruct_state_drain_run) 1100 sh->reconstruct_state = reconstruct_state_drain_result; 1101 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) 1102 sh->reconstruct_state = reconstruct_state_prexor_drain_result; 1103 else { 1104 BUG_ON(sh->reconstruct_state != reconstruct_state_run); 1105 sh->reconstruct_state = reconstruct_state_result; 1106 } 1107 1108 set_bit(STRIPE_HANDLE, &sh->state); 1109 release_stripe(sh); 1110} 1111 1112static void 1113ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 1114 struct dma_async_tx_descriptor *tx) 1115{ 1116 int disks = sh->disks; 1117 struct page **xor_srcs = percpu->scribble; 1118 struct async_submit_ctl submit; 1119 int count = 0, pd_idx = sh->pd_idx, i; 1120 struct page *xor_dest; 1121 int prexor = 0; 1122 unsigned long flags; 1123 1124 pr_debug("%s: stripe %llu\n", __func__, 1125 (unsigned long long)sh->sector); 1126 1127 /* check if prexor is active which means only process blocks 1128 * that are part of a read-modify-write (written) 1129 */ 1130 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { 1131 prexor = 1; 1132 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1133 for (i = disks; i--; ) { 1134 struct r5dev *dev = &sh->dev[i]; 1135 if (dev->written) 1136 xor_srcs[count++] = dev->page; 1137 } 1138 } else { 1139 xor_dest = sh->dev[pd_idx].page; 1140 for (i = disks; i--; ) { 1141 struct r5dev *dev = &sh->dev[i]; 1142 if (i != pd_idx) 1143 xor_srcs[count++] = dev->page; 1144 } 1145 } 1146 1147 /* 1/ if we prexor'd then the dest is reused as a source 1148 * 2/ if we did not prexor then we are redoing the parity 1149 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST 1150 * for the synchronous xor case 1151 */ 1152 flags = ASYNC_TX_ACK | 1153 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); 1154 1155 atomic_inc(&sh->count); 1156 1157 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, 1158 to_addr_conv(sh, percpu)); 1159 if (unlikely(count == 1)) 1160 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 1161 else 1162 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1163} 1164 1165static void 1166ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, 1167 struct dma_async_tx_descriptor *tx) 1168{ 1169 struct async_submit_ctl submit; 1170 struct page **blocks = percpu->scribble; 1171 int count; 1172 1173 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); 1174 1175 count = set_syndrome_sources(blocks, sh); 1176 1177 atomic_inc(&sh->count); 1178 1179 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, 1180 sh, to_addr_conv(sh, percpu)); 1181 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 1182} 1183 1184static void ops_complete_check(void *stripe_head_ref) 1185{ 1186 struct stripe_head *sh = stripe_head_ref; 1187 1188 pr_debug("%s: stripe %llu\n", __func__, 1189 (unsigned long long)sh->sector); 1190 1191 sh->check_state = check_state_check_result; 1192 set_bit(STRIPE_HANDLE, &sh->state); 1193 release_stripe(sh); 1194} 1195 1196static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) 1197{ 1198 int disks = sh->disks; 1199 int pd_idx = sh->pd_idx; 1200 int qd_idx = sh->qd_idx; 1201 struct page *xor_dest; 1202 struct page **xor_srcs = percpu->scribble; 1203 struct dma_async_tx_descriptor *tx; 1204 struct async_submit_ctl submit; 1205 int count; 1206 int i; 1207 1208 pr_debug("%s: stripe %llu\n", __func__, 1209 (unsigned long long)sh->sector); 1210 1211 count = 0; 1212 xor_dest = sh->dev[pd_idx].page; 1213 xor_srcs[count++] = xor_dest; 1214 for (i = disks; i--; ) { 1215 if (i == pd_idx || i == qd_idx) 1216 continue; 1217 xor_srcs[count++] = sh->dev[i].page; 1218 } 1219 1220 init_async_submit(&submit, 0, NULL, NULL, NULL, 1221 to_addr_conv(sh, percpu)); 1222 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, 1223 &sh->ops.zero_sum_result, &submit); 1224 1225 atomic_inc(&sh->count); 1226 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); 1227 tx = async_trigger_callback(&submit); 1228} 1229 1230static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) 1231{ 1232 struct page **srcs = percpu->scribble; 1233 struct async_submit_ctl submit; 1234 int count; 1235 1236 pr_debug("%s: stripe %llu checkp: %d\n", __func__, 1237 (unsigned long long)sh->sector, checkp); 1238 1239 count = set_syndrome_sources(srcs, sh); 1240 if (!checkp) 1241 srcs[count] = NULL; 1242 1243 atomic_inc(&sh->count); 1244 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, 1245 sh, to_addr_conv(sh, percpu)); 1246 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, 1247 &sh->ops.zero_sum_result, percpu->spare_page, &submit); 1248} 1249 1250static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1251{ 1252 int overlap_clear = 0, i, disks = sh->disks; 1253 struct dma_async_tx_descriptor *tx = NULL; 1254 struct r5conf *conf = sh->raid_conf; 1255 int level = conf->level; 1256 struct raid5_percpu *percpu; 1257 unsigned long cpu; 1258 1259 cpu = get_cpu(); 1260 percpu = per_cpu_ptr(conf->percpu, cpu); 1261 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { 1262 ops_run_biofill(sh); 1263 overlap_clear++; 1264 } 1265 1266 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { 1267 if (level < 6) 1268 tx = ops_run_compute5(sh, percpu); 1269 else { 1270 if (sh->ops.target2 < 0 || sh->ops.target < 0) 1271 tx = ops_run_compute6_1(sh, percpu); 1272 else 1273 tx = ops_run_compute6_2(sh, percpu); 1274 } 1275 /* terminate the chain if reconstruct is not set to be run */ 1276 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) 1277 async_tx_ack(tx); 1278 } 1279 1280 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) 1281 tx = ops_run_prexor(sh, percpu, tx); 1282 1283 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { 1284 tx = ops_run_biodrain(sh, tx); 1285 overlap_clear++; 1286 } 1287 1288 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { 1289 if (level < 6) 1290 ops_run_reconstruct5(sh, percpu, tx); 1291 else 1292 ops_run_reconstruct6(sh, percpu, tx); 1293 } 1294 1295 if (test_bit(STRIPE_OP_CHECK, &ops_request)) { 1296 if (sh->check_state == check_state_run) 1297 ops_run_check_p(sh, percpu); 1298 else if (sh->check_state == check_state_run_q) 1299 ops_run_check_pq(sh, percpu, 0); 1300 else if (sh->check_state == check_state_run_pq) 1301 ops_run_check_pq(sh, percpu, 1); 1302 else 1303 BUG(); 1304 } 1305 1306 if (overlap_clear) 1307 for (i = disks; i--; ) { 1308 struct r5dev *dev = &sh->dev[i]; 1309 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1310 wake_up(&sh->raid_conf->wait_for_overlap); 1311 } 1312 put_cpu(); 1313} 1314 1315#ifdef CONFIG_MULTICORE_RAID456 1316static void async_run_ops(void *param, async_cookie_t cookie) 1317{ 1318 struct stripe_head *sh = param; 1319 unsigned long ops_request = sh->ops.request; 1320 1321 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); 1322 wake_up(&sh->ops.wait_for_ops); 1323 1324 __raid_run_ops(sh, ops_request); 1325 release_stripe(sh); 1326} 1327 1328static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1329{ 1330 /* since handle_stripe can be called outside of raid5d context 1331 * we need to ensure sh->ops.request is de-staged before another 1332 * request arrives 1333 */ 1334 wait_event(sh->ops.wait_for_ops, 1335 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); 1336 sh->ops.request = ops_request; 1337 1338 atomic_inc(&sh->count); 1339 async_schedule(async_run_ops, sh); 1340} 1341#else 1342#define raid_run_ops __raid_run_ops 1343#endif 1344 1345static int grow_one_stripe(struct r5conf *conf) 1346{ 1347 struct stripe_head *sh; 1348 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL); 1349 if (!sh) 1350 return 0; 1351 1352 sh->raid_conf = conf; 1353 #ifdef CONFIG_MULTICORE_RAID456 1354 init_waitqueue_head(&sh->ops.wait_for_ops); 1355 #endif 1356 1357 if (grow_buffers(sh)) { 1358 shrink_buffers(sh); 1359 kmem_cache_free(conf->slab_cache, sh); 1360 return 0; 1361 } 1362 /* we just created an active stripe so... */ 1363 atomic_set(&sh->count, 1); 1364 atomic_inc(&conf->active_stripes); 1365 INIT_LIST_HEAD(&sh->lru); 1366 release_stripe(sh); 1367 return 1; 1368} 1369 1370static int grow_stripes(struct r5conf *conf, int num) 1371{ 1372 struct kmem_cache *sc; 1373 int devs = max(conf->raid_disks, conf->previous_raid_disks); 1374 1375 if (conf->mddev->gendisk) 1376 sprintf(conf->cache_name[0], 1377 "raid%d-%s", conf->level, mdname(conf->mddev)); 1378 else 1379 sprintf(conf->cache_name[0], 1380 "raid%d-%p", conf->level, conf->mddev); 1381 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]); 1382 1383 conf->active_name = 0; 1384 sc = kmem_cache_create(conf->cache_name[conf->active_name], 1385 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 1386 0, 0, NULL); 1387 if (!sc) 1388 return 1; 1389 conf->slab_cache = sc; 1390 conf->pool_size = devs; 1391 while (num--) 1392 if (!grow_one_stripe(conf)) 1393 return 1; 1394 return 0; 1395} 1396 1397/** 1398 * scribble_len - return the required size of the scribble region 1399 * @num - total number of disks in the array 1400 * 1401 * The size must be enough to contain: 1402 * 1/ a struct page pointer for each device in the array +2 1403 * 2/ room to convert each entry in (1) to its corresponding dma 1404 * (dma_map_page()) or page (page_address()) address. 1405 * 1406 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we 1407 * calculate over all devices (not just the data blocks), using zeros in place 1408 * of the P and Q blocks. 1409 */ 1410static size_t scribble_len(int num) 1411{ 1412 size_t len; 1413 1414 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); 1415 1416 return len; 1417} 1418 1419static int resize_stripes(struct r5conf *conf, int newsize) 1420{ 1421 /* Make all the stripes able to hold 'newsize' devices. 1422 * New slots in each stripe get 'page' set to a new page. 1423 * 1424 * This happens in stages: 1425 * 1/ create a new kmem_cache and allocate the required number of 1426 * stripe_heads. 1427 * 2/ gather all the old stripe_heads and tranfer the pages across 1428 * to the new stripe_heads. This will have the side effect of 1429 * freezing the array as once all stripe_heads have been collected, 1430 * no IO will be possible. Old stripe heads are freed once their 1431 * pages have been transferred over, and the old kmem_cache is 1432 * freed when all stripes are done. 1433 * 3/ reallocate conf->disks to be suitable bigger. If this fails, 1434 * we simple return a failre status - no need to clean anything up. 1435 * 4/ allocate new pages for the new slots in the new stripe_heads. 1436 * If this fails, we don't bother trying the shrink the 1437 * stripe_heads down again, we just leave them as they are. 1438 * As each stripe_head is processed the new one is released into 1439 * active service. 1440 * 1441 * Once step2 is started, we cannot afford to wait for a write, 1442 * so we use GFP_NOIO allocations. 1443 */ 1444 struct stripe_head *osh, *nsh; 1445 LIST_HEAD(newstripes); 1446 struct disk_info *ndisks; 1447 unsigned long cpu; 1448 int err; 1449 struct kmem_cache *sc; 1450 int i; 1451 1452 if (newsize <= conf->pool_size) 1453 return 0; /* never bother to shrink */ 1454 1455 err = md_allow_write(conf->mddev); 1456 if (err) 1457 return err; 1458 1459 /* Step 1 */ 1460 sc = kmem_cache_create(conf->cache_name[1-conf->active_name], 1461 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), 1462 0, 0, NULL); 1463 if (!sc) 1464 return -ENOMEM; 1465 1466 for (i = conf->max_nr_stripes; i; i--) { 1467 nsh = kmem_cache_zalloc(sc, GFP_KERNEL); 1468 if (!nsh) 1469 break; 1470 1471 nsh->raid_conf = conf; 1472 #ifdef CONFIG_MULTICORE_RAID456 1473 init_waitqueue_head(&nsh->ops.wait_for_ops); 1474 #endif 1475 1476 list_add(&nsh->lru, &newstripes); 1477 } 1478 if (i) { 1479 /* didn't get enough, give up */ 1480 while (!list_empty(&newstripes)) { 1481 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1482 list_del(&nsh->lru); 1483 kmem_cache_free(sc, nsh); 1484 } 1485 kmem_cache_destroy(sc); 1486 return -ENOMEM; 1487 } 1488 /* Step 2 - Must use GFP_NOIO now. 1489 * OK, we have enough stripes, start collecting inactive 1490 * stripes and copying them over 1491 */ 1492 list_for_each_entry(nsh, &newstripes, lru) { 1493 spin_lock_irq(&conf->device_lock); 1494 wait_event_lock_irq(conf->wait_for_stripe, 1495 !list_empty(&conf->inactive_list), 1496 conf->device_lock, 1497 ); 1498 osh = get_free_stripe(conf); 1499 spin_unlock_irq(&conf->device_lock); 1500 atomic_set(&nsh->count, 1); 1501 for(i=0; i<conf->pool_size; i++) 1502 nsh->dev[i].page = osh->dev[i].page; 1503 for( ; i<newsize; i++) 1504 nsh->dev[i].page = NULL; 1505 kmem_cache_free(conf->slab_cache, osh); 1506 } 1507 kmem_cache_destroy(conf->slab_cache); 1508 1509 /* Step 3. 1510 * At this point, we are holding all the stripes so the array 1511 * is completely stalled, so now is a good time to resize 1512 * conf->disks and the scribble region 1513 */ 1514 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); 1515 if (ndisks) { 1516 for (i=0; i<conf->raid_disks; i++) 1517 ndisks[i] = conf->disks[i]; 1518 kfree(conf->disks); 1519 conf->disks = ndisks; 1520 } else 1521 err = -ENOMEM; 1522 1523 get_online_cpus(); 1524 conf->scribble_len = scribble_len(newsize); 1525 for_each_present_cpu(cpu) { 1526 struct raid5_percpu *percpu; 1527 void *scribble; 1528 1529 percpu = per_cpu_ptr(conf->percpu, cpu); 1530 scribble = kmalloc(conf->scribble_len, GFP_NOIO); 1531 1532 if (scribble) { 1533 kfree(percpu->scribble); 1534 percpu->scribble = scribble; 1535 } else { 1536 err = -ENOMEM; 1537 break; 1538 } 1539 } 1540 put_online_cpus(); 1541 1542 /* Step 4, return new stripes to service */ 1543 while(!list_empty(&newstripes)) { 1544 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1545 list_del_init(&nsh->lru); 1546 1547 for (i=conf->raid_disks; i < newsize; i++) 1548 if (nsh->dev[i].page == NULL) { 1549 struct page *p = alloc_page(GFP_NOIO); 1550 nsh->dev[i].page = p; 1551 if (!p) 1552 err = -ENOMEM; 1553 } 1554 release_stripe(nsh); 1555 } 1556 /* critical section pass, GFP_NOIO no longer needed */ 1557 1558 conf->slab_cache = sc; 1559 conf->active_name = 1-conf->active_name; 1560 conf->pool_size = newsize; 1561 return err; 1562} 1563 1564static int drop_one_stripe(struct r5conf *conf) 1565{ 1566 struct stripe_head *sh; 1567 1568 spin_lock_irq(&conf->device_lock); 1569 sh = get_free_stripe(conf); 1570 spin_unlock_irq(&conf->device_lock); 1571 if (!sh) 1572 return 0; 1573 BUG_ON(atomic_read(&sh->count)); 1574 shrink_buffers(sh); 1575 kmem_cache_free(conf->slab_cache, sh); 1576 atomic_dec(&conf->active_stripes); 1577 return 1; 1578} 1579 1580static void shrink_stripes(struct r5conf *conf) 1581{ 1582 while (drop_one_stripe(conf)) 1583 ; 1584 1585 if (conf->slab_cache) 1586 kmem_cache_destroy(conf->slab_cache); 1587 conf->slab_cache = NULL; 1588} 1589 1590static void raid5_end_read_request(struct bio * bi, int error) 1591{ 1592 struct stripe_head *sh = bi->bi_private; 1593 struct r5conf *conf = sh->raid_conf; 1594 int disks = sh->disks, i; 1595 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1596 char b[BDEVNAME_SIZE]; 1597 struct md_rdev *rdev; 1598 1599 1600 for (i=0 ; i<disks; i++) 1601 if (bi == &sh->dev[i].req) 1602 break; 1603 1604 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", 1605 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1606 uptodate); 1607 if (i == disks) { 1608 BUG(); 1609 return; 1610 } 1611 1612 if (uptodate) { 1613 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1614 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 1615 rdev = conf->disks[i].rdev; 1616 printk_ratelimited( 1617 KERN_INFO 1618 "md/raid:%s: read error corrected" 1619 " (%lu sectors at %llu on %s)\n", 1620 mdname(conf->mddev), STRIPE_SECTORS, 1621 (unsigned long long)(sh->sector 1622 + rdev->data_offset), 1623 bdevname(rdev->bdev, b)); 1624 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); 1625 clear_bit(R5_ReadError, &sh->dev[i].flags); 1626 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1627 } 1628 if (atomic_read(&conf->disks[i].rdev->read_errors)) 1629 atomic_set(&conf->disks[i].rdev->read_errors, 0); 1630 } else { 1631 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); 1632 int retry = 0; 1633 rdev = conf->disks[i].rdev; 1634 1635 clear_bit(R5_UPTODATE, &sh->dev[i].flags); 1636 atomic_inc(&rdev->read_errors); 1637 if (conf->mddev->degraded >= conf->max_degraded) 1638 printk_ratelimited( 1639 KERN_WARNING 1640 "md/raid:%s: read error not correctable " 1641 "(sector %llu on %s).\n", 1642 mdname(conf->mddev), 1643 (unsigned long long)(sh->sector 1644 + rdev->data_offset), 1645 bdn); 1646 else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) 1647 /* Oh, no!!! */ 1648 printk_ratelimited( 1649 KERN_WARNING 1650 "md/raid:%s: read error NOT corrected!! " 1651 "(sector %llu on %s).\n", 1652 mdname(conf->mddev), 1653 (unsigned long long)(sh->sector 1654 + rdev->data_offset), 1655 bdn); 1656 else if (atomic_read(&rdev->read_errors) 1657 > conf->max_nr_stripes) 1658 printk(KERN_WARNING 1659 "md/raid:%s: Too many read errors, failing device %s.\n", 1660 mdname(conf->mddev), bdn); 1661 else 1662 retry = 1; 1663 if (retry) 1664 set_bit(R5_ReadError, &sh->dev[i].flags); 1665 else { 1666 clear_bit(R5_ReadError, &sh->dev[i].flags); 1667 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1668 md_error(conf->mddev, rdev); 1669 } 1670 } 1671 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1672 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1673 set_bit(STRIPE_HANDLE, &sh->state); 1674 release_stripe(sh); 1675} 1676 1677static void raid5_end_write_request(struct bio *bi, int error) 1678{ 1679 struct stripe_head *sh = bi->bi_private; 1680 struct r5conf *conf = sh->raid_conf; 1681 int disks = sh->disks, i; 1682 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1683 sector_t first_bad; 1684 int bad_sectors; 1685 1686 for (i=0 ; i<disks; i++) 1687 if (bi == &sh->dev[i].req) 1688 break; 1689 1690 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", 1691 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1692 uptodate); 1693 if (i == disks) { 1694 BUG(); 1695 return; 1696 } 1697 1698 if (!uptodate) { 1699 set_bit(WriteErrorSeen, &conf->disks[i].rdev->flags); 1700 set_bit(R5_WriteError, &sh->dev[i].flags); 1701 } else if (is_badblock(conf->disks[i].rdev, sh->sector, STRIPE_SECTORS, 1702 &first_bad, &bad_sectors)) 1703 set_bit(R5_MadeGood, &sh->dev[i].flags); 1704 1705 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1706 1707 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1708 set_bit(STRIPE_HANDLE, &sh->state); 1709 release_stripe(sh); 1710} 1711 1712 1713static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous); 1714 1715static void raid5_build_block(struct stripe_head *sh, int i, int previous) 1716{ 1717 struct r5dev *dev = &sh->dev[i]; 1718 1719 bio_init(&dev->req); 1720 dev->req.bi_io_vec = &dev->vec; 1721 dev->req.bi_vcnt++; 1722 dev->req.bi_max_vecs++; 1723 dev->vec.bv_page = dev->page; 1724 dev->vec.bv_len = STRIPE_SIZE; 1725 dev->vec.bv_offset = 0; 1726 1727 dev->req.bi_sector = sh->sector; 1728 dev->req.bi_private = sh; 1729 1730 dev->flags = 0; 1731 dev->sector = compute_blocknr(sh, i, previous); 1732} 1733 1734static void error(struct mddev *mddev, struct md_rdev *rdev) 1735{ 1736 char b[BDEVNAME_SIZE]; 1737 struct r5conf *conf = mddev->private; 1738 unsigned long flags; 1739 pr_debug("raid456: error called\n"); 1740 1741 spin_lock_irqsave(&conf->device_lock, flags); 1742 clear_bit(In_sync, &rdev->flags); 1743 mddev->degraded = calc_degraded(conf); 1744 spin_unlock_irqrestore(&conf->device_lock, flags); 1745 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1746 1747 set_bit(Blocked, &rdev->flags); 1748 set_bit(Faulty, &rdev->flags); 1749 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1750 printk(KERN_ALERT 1751 "md/raid:%s: Disk failure on %s, disabling device.\n" 1752 "md/raid:%s: Operation continuing on %d devices.\n", 1753 mdname(mddev), 1754 bdevname(rdev->bdev, b), 1755 mdname(mddev), 1756 conf->raid_disks - mddev->degraded); 1757} 1758 1759/* 1760 * Input: a 'big' sector number, 1761 * Output: index of the data and parity disk, and the sector # in them. 1762 */ 1763static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector, 1764 int previous, int *dd_idx, 1765 struct stripe_head *sh) 1766{ 1767 sector_t stripe, stripe2; 1768 sector_t chunk_number; 1769 unsigned int chunk_offset; 1770 int pd_idx, qd_idx; 1771 int ddf_layout = 0; 1772 sector_t new_sector; 1773 int algorithm = previous ? conf->prev_algo 1774 : conf->algorithm; 1775 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1776 : conf->chunk_sectors; 1777 int raid_disks = previous ? conf->previous_raid_disks 1778 : conf->raid_disks; 1779 int data_disks = raid_disks - conf->max_degraded; 1780 1781 /* First compute the information on this sector */ 1782 1783 /* 1784 * Compute the chunk number and the sector offset inside the chunk 1785 */ 1786 chunk_offset = sector_div(r_sector, sectors_per_chunk); 1787 chunk_number = r_sector; 1788 1789 /* 1790 * Compute the stripe number 1791 */ 1792 stripe = chunk_number; 1793 *dd_idx = sector_div(stripe, data_disks); 1794 stripe2 = stripe; 1795 /* 1796 * Select the parity disk based on the user selected algorithm. 1797 */ 1798 pd_idx = qd_idx = -1; 1799 switch(conf->level) { 1800 case 4: 1801 pd_idx = data_disks; 1802 break; 1803 case 5: 1804 switch (algorithm) { 1805 case ALGORITHM_LEFT_ASYMMETRIC: 1806 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1807 if (*dd_idx >= pd_idx) 1808 (*dd_idx)++; 1809 break; 1810 case ALGORITHM_RIGHT_ASYMMETRIC: 1811 pd_idx = sector_div(stripe2, raid_disks); 1812 if (*dd_idx >= pd_idx) 1813 (*dd_idx)++; 1814 break; 1815 case ALGORITHM_LEFT_SYMMETRIC: 1816 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1817 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1818 break; 1819 case ALGORITHM_RIGHT_SYMMETRIC: 1820 pd_idx = sector_div(stripe2, raid_disks); 1821 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1822 break; 1823 case ALGORITHM_PARITY_0: 1824 pd_idx = 0; 1825 (*dd_idx)++; 1826 break; 1827 case ALGORITHM_PARITY_N: 1828 pd_idx = data_disks; 1829 break; 1830 default: 1831 BUG(); 1832 } 1833 break; 1834 case 6: 1835 1836 switch (algorithm) { 1837 case ALGORITHM_LEFT_ASYMMETRIC: 1838 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1839 qd_idx = pd_idx + 1; 1840 if (pd_idx == raid_disks-1) { 1841 (*dd_idx)++; /* Q D D D P */ 1842 qd_idx = 0; 1843 } else if (*dd_idx >= pd_idx) 1844 (*dd_idx) += 2; /* D D P Q D */ 1845 break; 1846 case ALGORITHM_RIGHT_ASYMMETRIC: 1847 pd_idx = sector_div(stripe2, raid_disks); 1848 qd_idx = pd_idx + 1; 1849 if (pd_idx == raid_disks-1) { 1850 (*dd_idx)++; /* Q D D D P */ 1851 qd_idx = 0; 1852 } else if (*dd_idx >= pd_idx) 1853 (*dd_idx) += 2; /* D D P Q D */ 1854 break; 1855 case ALGORITHM_LEFT_SYMMETRIC: 1856 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1857 qd_idx = (pd_idx + 1) % raid_disks; 1858 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1859 break; 1860 case ALGORITHM_RIGHT_SYMMETRIC: 1861 pd_idx = sector_div(stripe2, raid_disks); 1862 qd_idx = (pd_idx + 1) % raid_disks; 1863 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1864 break; 1865 1866 case ALGORITHM_PARITY_0: 1867 pd_idx = 0; 1868 qd_idx = 1; 1869 (*dd_idx) += 2; 1870 break; 1871 case ALGORITHM_PARITY_N: 1872 pd_idx = data_disks; 1873 qd_idx = data_disks + 1; 1874 break; 1875 1876 case ALGORITHM_ROTATING_ZERO_RESTART: 1877 /* Exactly the same as RIGHT_ASYMMETRIC, but or 1878 * of blocks for computing Q is different. 1879 */ 1880 pd_idx = sector_div(stripe2, raid_disks); 1881 qd_idx = pd_idx + 1; 1882 if (pd_idx == raid_disks-1) { 1883 (*dd_idx)++; /* Q D D D P */ 1884 qd_idx = 0; 1885 } else if (*dd_idx >= pd_idx) 1886 (*dd_idx) += 2; /* D D P Q D */ 1887 ddf_layout = 1; 1888 break; 1889 1890 case ALGORITHM_ROTATING_N_RESTART: 1891 /* Same a left_asymmetric, by first stripe is 1892 * D D D P Q rather than 1893 * Q D D D P 1894 */ 1895 stripe2 += 1; 1896 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1897 qd_idx = pd_idx + 1; 1898 if (pd_idx == raid_disks-1) { 1899 (*dd_idx)++; /* Q D D D P */ 1900 qd_idx = 0; 1901 } else if (*dd_idx >= pd_idx) 1902 (*dd_idx) += 2; /* D D P Q D */ 1903 ddf_layout = 1; 1904 break; 1905 1906 case ALGORITHM_ROTATING_N_CONTINUE: 1907 /* Same as left_symmetric but Q is before P */ 1908 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1909 qd_idx = (pd_idx + raid_disks - 1) % raid_disks; 1910 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1911 ddf_layout = 1; 1912 break; 1913 1914 case ALGORITHM_LEFT_ASYMMETRIC_6: 1915 /* RAID5 left_asymmetric, with Q on last device */ 1916 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1917 if (*dd_idx >= pd_idx) 1918 (*dd_idx)++; 1919 qd_idx = raid_disks - 1; 1920 break; 1921 1922 case ALGORITHM_RIGHT_ASYMMETRIC_6: 1923 pd_idx = sector_div(stripe2, raid_disks-1); 1924 if (*dd_idx >= pd_idx) 1925 (*dd_idx)++; 1926 qd_idx = raid_disks - 1; 1927 break; 1928 1929 case ALGORITHM_LEFT_SYMMETRIC_6: 1930 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1931 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1932 qd_idx = raid_disks - 1; 1933 break; 1934 1935 case ALGORITHM_RIGHT_SYMMETRIC_6: 1936 pd_idx = sector_div(stripe2, raid_disks-1); 1937 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1938 qd_idx = raid_disks - 1; 1939 break; 1940 1941 case ALGORITHM_PARITY_0_6: 1942 pd_idx = 0; 1943 (*dd_idx)++; 1944 qd_idx = raid_disks - 1; 1945 break; 1946 1947 default: 1948 BUG(); 1949 } 1950 break; 1951 } 1952 1953 if (sh) { 1954 sh->pd_idx = pd_idx; 1955 sh->qd_idx = qd_idx; 1956 sh->ddf_layout = ddf_layout; 1957 } 1958 /* 1959 * Finally, compute the new sector number 1960 */ 1961 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; 1962 return new_sector; 1963} 1964 1965 1966static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) 1967{ 1968 struct r5conf *conf = sh->raid_conf; 1969 int raid_disks = sh->disks; 1970 int data_disks = raid_disks - conf->max_degraded; 1971 sector_t new_sector = sh->sector, check; 1972 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1973 : conf->chunk_sectors; 1974 int algorithm = previous ? conf->prev_algo 1975 : conf->algorithm; 1976 sector_t stripe; 1977 int chunk_offset; 1978 sector_t chunk_number; 1979 int dummy1, dd_idx = i; 1980 sector_t r_sector; 1981 struct stripe_head sh2; 1982 1983 1984 chunk_offset = sector_div(new_sector, sectors_per_chunk); 1985 stripe = new_sector; 1986 1987 if (i == sh->pd_idx) 1988 return 0; 1989 switch(conf->level) { 1990 case 4: break; 1991 case 5: 1992 switch (algorithm) { 1993 case ALGORITHM_LEFT_ASYMMETRIC: 1994 case ALGORITHM_RIGHT_ASYMMETRIC: 1995 if (i > sh->pd_idx) 1996 i--; 1997 break; 1998 case ALGORITHM_LEFT_SYMMETRIC: 1999 case ALGORITHM_RIGHT_SYMMETRIC: 2000 if (i < sh->pd_idx) 2001 i += raid_disks; 2002 i -= (sh->pd_idx + 1); 2003 break; 2004 case ALGORITHM_PARITY_0: 2005 i -= 1; 2006 break; 2007 case ALGORITHM_PARITY_N: 2008 break; 2009 default: 2010 BUG(); 2011 } 2012 break; 2013 case 6: 2014 if (i == sh->qd_idx) 2015 return 0; /* It is the Q disk */ 2016 switch (algorithm) { 2017 case ALGORITHM_LEFT_ASYMMETRIC: 2018 case ALGORITHM_RIGHT_ASYMMETRIC: 2019 case ALGORITHM_ROTATING_ZERO_RESTART: 2020 case ALGORITHM_ROTATING_N_RESTART: 2021 if (sh->pd_idx == raid_disks-1) 2022 i--; /* Q D D D P */ 2023 else if (i > sh->pd_idx) 2024 i -= 2; /* D D P Q D */ 2025 break; 2026 case ALGORITHM_LEFT_SYMMETRIC: 2027 case ALGORITHM_RIGHT_SYMMETRIC: 2028 if (sh->pd_idx == raid_disks-1) 2029 i--; /* Q D D D P */ 2030 else { 2031 /* D D P Q D */ 2032 if (i < sh->pd_idx) 2033 i += raid_disks; 2034 i -= (sh->pd_idx + 2); 2035 } 2036 break; 2037 case ALGORITHM_PARITY_0: 2038 i -= 2; 2039 break; 2040 case ALGORITHM_PARITY_N: 2041 break; 2042 case ALGORITHM_ROTATING_N_CONTINUE: 2043 /* Like left_symmetric, but P is before Q */ 2044 if (sh->pd_idx == 0) 2045 i--; /* P D D D Q */ 2046 else { 2047 /* D D Q P D */ 2048 if (i < sh->pd_idx) 2049 i += raid_disks; 2050 i -= (sh->pd_idx + 1); 2051 } 2052 break; 2053 case ALGORITHM_LEFT_ASYMMETRIC_6: 2054 case ALGORITHM_RIGHT_ASYMMETRIC_6: 2055 if (i > sh->pd_idx) 2056 i--; 2057 break; 2058 case ALGORITHM_LEFT_SYMMETRIC_6: 2059 case ALGORITHM_RIGHT_SYMMETRIC_6: 2060 if (i < sh->pd_idx) 2061 i += data_disks + 1; 2062 i -= (sh->pd_idx + 1); 2063 break; 2064 case ALGORITHM_PARITY_0_6: 2065 i -= 1; 2066 break; 2067 default: 2068 BUG(); 2069 } 2070 break; 2071 } 2072 2073 chunk_number = stripe * data_disks + i; 2074 r_sector = chunk_number * sectors_per_chunk + chunk_offset; 2075 2076 check = raid5_compute_sector(conf, r_sector, 2077 previous, &dummy1, &sh2); 2078 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx 2079 || sh2.qd_idx != sh->qd_idx) { 2080 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n", 2081 mdname(conf->mddev)); 2082 return 0; 2083 } 2084 return r_sector; 2085} 2086 2087 2088static void 2089schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, 2090 int rcw, int expand) 2091{ 2092 int i, pd_idx = sh->pd_idx, disks = sh->disks; 2093 struct r5conf *conf = sh->raid_conf; 2094 int level = conf->level; 2095 2096 if (rcw) { 2097 /* if we are not expanding this is a proper write request, and 2098 * there will be bios with new data to be drained into the 2099 * stripe cache 2100 */ 2101 if (!expand) { 2102 sh->reconstruct_state = reconstruct_state_drain_run; 2103 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2104 } else 2105 sh->reconstruct_state = reconstruct_state_run; 2106 2107 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2108 2109 for (i = disks; i--; ) { 2110 struct r5dev *dev = &sh->dev[i]; 2111 2112 if (dev->towrite) { 2113 set_bit(R5_LOCKED, &dev->flags); 2114 set_bit(R5_Wantdrain, &dev->flags); 2115 if (!expand) 2116 clear_bit(R5_UPTODATE, &dev->flags); 2117 s->locked++; 2118 } 2119 } 2120 if (s->locked + conf->max_degraded == disks) 2121 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) 2122 atomic_inc(&conf->pending_full_writes); 2123 } else { 2124 BUG_ON(level == 6); 2125 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || 2126 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); 2127 2128 sh->reconstruct_state = reconstruct_state_prexor_drain_run; 2129 set_bit(STRIPE_OP_PREXOR, &s->ops_request); 2130 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2131 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2132 2133 for (i = disks; i--; ) { 2134 struct r5dev *dev = &sh->dev[i]; 2135 if (i == pd_idx) 2136 continue; 2137 2138 if (dev->towrite && 2139 (test_bit(R5_UPTODATE, &dev->flags) || 2140 test_bit(R5_Wantcompute, &dev->flags))) { 2141 set_bit(R5_Wantdrain, &dev->flags); 2142 set_bit(R5_LOCKED, &dev->flags); 2143 clear_bit(R5_UPTODATE, &dev->flags); 2144 s->locked++; 2145 } 2146 } 2147 } 2148 2149 /* keep the parity disk(s) locked while asynchronous operations 2150 * are in flight 2151 */ 2152 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 2153 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2154 s->locked++; 2155 2156 if (level == 6) { 2157 int qd_idx = sh->qd_idx; 2158 struct r5dev *dev = &sh->dev[qd_idx]; 2159 2160 set_bit(R5_LOCKED, &dev->flags); 2161 clear_bit(R5_UPTODATE, &dev->flags); 2162 s->locked++; 2163 } 2164 2165 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", 2166 __func__, (unsigned long long)sh->sector, 2167 s->locked, s->ops_request); 2168} 2169 2170/* 2171 * Each stripe/dev can have one or more bion attached. 2172 * toread/towrite point to the first in a chain. 2173 * The bi_next chain must be in order. 2174 */ 2175static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 2176{ 2177 struct bio **bip; 2178 struct r5conf *conf = sh->raid_conf; 2179 int firstwrite=0; 2180 2181 pr_debug("adding bi b#%llu to stripe s#%llu\n", 2182 (unsigned long long)bi->bi_sector, 2183 (unsigned long long)sh->sector); 2184 2185 2186 spin_lock_irq(&conf->device_lock); 2187 if (forwrite) { 2188 bip = &sh->dev[dd_idx].towrite; 2189 if (*bip == NULL && sh->dev[dd_idx].written == NULL) 2190 firstwrite = 1; 2191 } else 2192 bip = &sh->dev[dd_idx].toread; 2193 while (*bip && (*bip)->bi_sector < bi->bi_sector) { 2194 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) 2195 goto overlap; 2196 bip = & (*bip)->bi_next; 2197 } 2198 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) 2199 goto overlap; 2200 2201 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); 2202 if (*bip) 2203 bi->bi_next = *bip; 2204 *bip = bi; 2205 bi->bi_phys_segments++; 2206 2207 if (forwrite) { 2208 /* check if page is covered */ 2209 sector_t sector = sh->dev[dd_idx].sector; 2210 for (bi=sh->dev[dd_idx].towrite; 2211 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && 2212 bi && bi->bi_sector <= sector; 2213 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { 2214 if (bi->bi_sector + (bi->bi_size>>9) >= sector) 2215 sector = bi->bi_sector + (bi->bi_size>>9); 2216 } 2217 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) 2218 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); 2219 } 2220 spin_unlock_irq(&conf->device_lock); 2221 2222 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", 2223 (unsigned long long)(*bip)->bi_sector, 2224 (unsigned long long)sh->sector, dd_idx); 2225 2226 if (conf->mddev->bitmap && firstwrite) { 2227 bitmap_startwrite(conf->mddev->bitmap, sh->sector, 2228 STRIPE_SECTORS, 0); 2229 sh->bm_seq = conf->seq_flush+1; 2230 set_bit(STRIPE_BIT_DELAY, &sh->state); 2231 } 2232 return 1; 2233 2234 overlap: 2235 set_bit(R5_Overlap, &sh->dev[dd_idx].flags); 2236 spin_unlock_irq(&conf->device_lock); 2237 return 0; 2238} 2239 2240static void end_reshape(struct r5conf *conf); 2241 2242static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, 2243 struct stripe_head *sh) 2244{ 2245 int sectors_per_chunk = 2246 previous ? conf->prev_chunk_sectors : conf->chunk_sectors; 2247 int dd_idx; 2248 int chunk_offset = sector_div(stripe, sectors_per_chunk); 2249 int disks = previous ? conf->previous_raid_disks : conf->raid_disks; 2250 2251 raid5_compute_sector(conf, 2252 stripe * (disks - conf->max_degraded) 2253 *sectors_per_chunk + chunk_offset, 2254 previous, 2255 &dd_idx, sh); 2256} 2257 2258static void 2259handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, 2260 struct stripe_head_state *s, int disks, 2261 struct bio **return_bi) 2262{ 2263 int i; 2264 for (i = disks; i--; ) { 2265 struct bio *bi; 2266 int bitmap_end = 0; 2267 2268 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 2269 struct md_rdev *rdev; 2270 rcu_read_lock(); 2271 rdev = rcu_dereference(conf->disks[i].rdev); 2272 if (rdev && test_bit(In_sync, &rdev->flags)) 2273 atomic_inc(&rdev->nr_pending); 2274 else 2275 rdev = NULL; 2276 rcu_read_unlock(); 2277 if (rdev) { 2278 if (!rdev_set_badblocks( 2279 rdev, 2280 sh->sector, 2281 STRIPE_SECTORS, 0)) 2282 md_error(conf->mddev, rdev); 2283 rdev_dec_pending(rdev, conf->mddev); 2284 } 2285 } 2286 spin_lock_irq(&conf->device_lock); 2287 /* fail all writes first */ 2288 bi = sh->dev[i].towrite; 2289 sh->dev[i].towrite = NULL; 2290 if (bi) { 2291 s->to_write--; 2292 bitmap_end = 1; 2293 } 2294 2295 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2296 wake_up(&conf->wait_for_overlap); 2297 2298 while (bi && bi->bi_sector < 2299 sh->dev[i].sector + STRIPE_SECTORS) { 2300 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2301 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2302 if (!raid5_dec_bi_phys_segments(bi)) { 2303 md_write_end(conf->mddev); 2304 bi->bi_next = *return_bi; 2305 *return_bi = bi; 2306 } 2307 bi = nextbi; 2308 } 2309 /* and fail all 'written' */ 2310 bi = sh->dev[i].written; 2311 sh->dev[i].written = NULL; 2312 if (bi) bitmap_end = 1; 2313 while (bi && bi->bi_sector < 2314 sh->dev[i].sector + STRIPE_SECTORS) { 2315 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 2316 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2317 if (!raid5_dec_bi_phys_segments(bi)) { 2318 md_write_end(conf->mddev); 2319 bi->bi_next = *return_bi; 2320 *return_bi = bi; 2321 } 2322 bi = bi2; 2323 } 2324 2325 /* fail any reads if this device is non-operational and 2326 * the data has not reached the cache yet. 2327 */ 2328 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && 2329 (!test_bit(R5_Insync, &sh->dev[i].flags) || 2330 test_bit(R5_ReadError, &sh->dev[i].flags))) { 2331 bi = sh->dev[i].toread; 2332 sh->dev[i].toread = NULL; 2333 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2334 wake_up(&conf->wait_for_overlap); 2335 if (bi) s->to_read--; 2336 while (bi && bi->bi_sector < 2337 sh->dev[i].sector + STRIPE_SECTORS) { 2338 struct bio *nextbi = 2339 r5_next_bio(bi, sh->dev[i].sector); 2340 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2341 if (!raid5_dec_bi_phys_segments(bi)) { 2342 bi->bi_next = *return_bi; 2343 *return_bi = bi; 2344 } 2345 bi = nextbi; 2346 } 2347 } 2348 spin_unlock_irq(&conf->device_lock); 2349 if (bitmap_end) 2350 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2351 STRIPE_SECTORS, 0, 0); 2352 /* If we were in the middle of a write the parity block might 2353 * still be locked - so just clear all R5_LOCKED flags 2354 */ 2355 clear_bit(R5_LOCKED, &sh->dev[i].flags); 2356 } 2357 2358 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2359 if (atomic_dec_and_test(&conf->pending_full_writes)) 2360 md_wakeup_thread(conf->mddev->thread); 2361} 2362 2363static void 2364handle_failed_sync(struct r5conf *conf, struct stripe_head *sh, 2365 struct stripe_head_state *s) 2366{ 2367 int abort = 0; 2368 int i; 2369 2370 md_done_sync(conf->mddev, STRIPE_SECTORS, 0); 2371 clear_bit(STRIPE_SYNCING, &sh->state); 2372 s->syncing = 0; 2373 /* There is nothing more to do for sync/check/repair. 2374 * For recover we need to record a bad block on all 2375 * non-sync devices, or abort the recovery 2376 */ 2377 if (!test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) 2378 return; 2379 /* During recovery devices cannot be removed, so locking and 2380 * refcounting of rdevs is not needed 2381 */ 2382 for (i = 0; i < conf->raid_disks; i++) { 2383 struct md_rdev *rdev = conf->disks[i].rdev; 2384 if (!rdev 2385 || test_bit(Faulty, &rdev->flags) 2386 || test_bit(In_sync, &rdev->flags)) 2387 continue; 2388 if (!rdev_set_badblocks(rdev, sh->sector, 2389 STRIPE_SECTORS, 0)) 2390 abort = 1; 2391 } 2392 if (abort) { 2393 conf->recovery_disabled = conf->mddev->recovery_disabled; 2394 set_bit(MD_RECOVERY_INTR, &conf->mddev->recovery); 2395 } 2396} 2397 2398/* fetch_block - checks the given member device to see if its data needs 2399 * to be read or computed to satisfy a request. 2400 * 2401 * Returns 1 when no more member devices need to be checked, otherwise returns 2402 * 0 to tell the loop in handle_stripe_fill to continue 2403 */ 2404static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, 2405 int disk_idx, int disks) 2406{ 2407 struct r5dev *dev = &sh->dev[disk_idx]; 2408 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], 2409 &sh->dev[s->failed_num[1]] }; 2410 2411 /* is the data in this block needed, and can we get it? */ 2412 if (!test_bit(R5_LOCKED, &dev->flags) && 2413 !test_bit(R5_UPTODATE, &dev->flags) && 2414 (dev->toread || 2415 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 2416 s->syncing || s->expanding || 2417 (s->failed >= 1 && fdev[0]->toread) || 2418 (s->failed >= 2 && fdev[1]->toread) || 2419 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && 2420 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || 2421 (sh->raid_conf->level == 6 && s->failed && s->to_write))) { 2422 /* we would like to get this block, possibly by computing it, 2423 * otherwise read it if the backing disk is insync 2424 */ 2425 BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); 2426 BUG_ON(test_bit(R5_Wantread, &dev->flags)); 2427 if ((s->uptodate == disks - 1) && 2428 (s->failed && (disk_idx == s->failed_num[0] || 2429 disk_idx == s->failed_num[1]))) { 2430 /* have disk failed, and we're requested to fetch it; 2431 * do compute it 2432 */ 2433 pr_debug("Computing stripe %llu block %d\n", 2434 (unsigned long long)sh->sector, disk_idx); 2435 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2436 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2437 set_bit(R5_Wantcompute, &dev->flags); 2438 sh->ops.target = disk_idx; 2439 sh->ops.target2 = -1; /* no 2nd target */ 2440 s->req_compute = 1; 2441 /* Careful: from this point on 'uptodate' is in the eye 2442 * of raid_run_ops which services 'compute' operations 2443 * before writes. R5_Wantcompute flags a block that will 2444 * be R5_UPTODATE by the time it is needed for a 2445 * subsequent operation. 2446 */ 2447 s->uptodate++; 2448 return 1; 2449 } else if (s->uptodate == disks-2 && s->failed >= 2) { 2450 /* Computing 2-failure is *very* expensive; only 2451 * do it if failed >= 2 2452 */ 2453 int other; 2454 for (other = disks; other--; ) { 2455 if (other == disk_idx) 2456 continue; 2457 if (!test_bit(R5_UPTODATE, 2458 &sh->dev[other].flags)) 2459 break; 2460 } 2461 BUG_ON(other < 0); 2462 pr_debug("Computing stripe %llu blocks %d,%d\n", 2463 (unsigned long long)sh->sector, 2464 disk_idx, other); 2465 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2466 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2467 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); 2468 set_bit(R5_Wantcompute, &sh->dev[other].flags); 2469 sh->ops.target = disk_idx; 2470 sh->ops.target2 = other; 2471 s->uptodate += 2; 2472 s->req_compute = 1; 2473 return 1; 2474 } else if (test_bit(R5_Insync, &dev->flags)) { 2475 set_bit(R5_LOCKED, &dev->flags); 2476 set_bit(R5_Wantread, &dev->flags); 2477 s->locked++; 2478 pr_debug("Reading block %d (sync=%d)\n", 2479 disk_idx, s->syncing); 2480 } 2481 } 2482 2483 return 0; 2484} 2485 2486/** 2487 * handle_stripe_fill - read or compute data to satisfy pending requests. 2488 */ 2489static void handle_stripe_fill(struct stripe_head *sh, 2490 struct stripe_head_state *s, 2491 int disks) 2492{ 2493 int i; 2494 2495 /* look for blocks to read/compute, skip this if a compute 2496 * is already in flight, or if the stripe contents are in the 2497 * midst of changing due to a write 2498 */ 2499 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && 2500 !sh->reconstruct_state) 2501 for (i = disks; i--; ) 2502 if (fetch_block(sh, s, i, disks)) 2503 break; 2504 set_bit(STRIPE_HANDLE, &sh->state); 2505} 2506 2507 2508/* handle_stripe_clean_event 2509 * any written block on an uptodate or failed drive can be returned. 2510 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 2511 * never LOCKED, so we don't need to test 'failed' directly. 2512 */ 2513static void handle_stripe_clean_event(struct r5conf *conf, 2514 struct stripe_head *sh, int disks, struct bio **return_bi) 2515{ 2516 int i; 2517 struct r5dev *dev; 2518 2519 for (i = disks; i--; ) 2520 if (sh->dev[i].written) { 2521 dev = &sh->dev[i]; 2522 if (!test_bit(R5_LOCKED, &dev->flags) && 2523 test_bit(R5_UPTODATE, &dev->flags)) { 2524 /* We can return any write requests */ 2525 struct bio *wbi, *wbi2; 2526 int bitmap_end = 0; 2527 pr_debug("Return write for disc %d\n", i); 2528 spin_lock_irq(&conf->device_lock); 2529 wbi = dev->written; 2530 dev->written = NULL; 2531 while (wbi && wbi->bi_sector < 2532 dev->sector + STRIPE_SECTORS) { 2533 wbi2 = r5_next_bio(wbi, dev->sector); 2534 if (!raid5_dec_bi_phys_segments(wbi)) { 2535 md_write_end(conf->mddev); 2536 wbi->bi_next = *return_bi; 2537 *return_bi = wbi; 2538 } 2539 wbi = wbi2; 2540 } 2541 if (dev->towrite == NULL) 2542 bitmap_end = 1; 2543 spin_unlock_irq(&conf->device_lock); 2544 if (bitmap_end) 2545 bitmap_endwrite(conf->mddev->bitmap, 2546 sh->sector, 2547 STRIPE_SECTORS, 2548 !test_bit(STRIPE_DEGRADED, &sh->state), 2549 0); 2550 } 2551 } 2552 2553 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2554 if (atomic_dec_and_test(&conf->pending_full_writes)) 2555 md_wakeup_thread(conf->mddev->thread); 2556} 2557 2558static void handle_stripe_dirtying(struct r5conf *conf, 2559 struct stripe_head *sh, 2560 struct stripe_head_state *s, 2561 int disks) 2562{ 2563 int rmw = 0, rcw = 0, i; 2564 if (conf->max_degraded == 2) { 2565 /* RAID6 requires 'rcw' in current implementation 2566 * Calculate the real rcw later - for now fake it 2567 * look like rcw is cheaper 2568 */ 2569 rcw = 1; rmw = 2; 2570 } else for (i = disks; i--; ) { 2571 /* would I have to read this buffer for read_modify_write */ 2572 struct r5dev *dev = &sh->dev[i]; 2573 if ((dev->towrite || i == sh->pd_idx) && 2574 !test_bit(R5_LOCKED, &dev->flags) && 2575 !(test_bit(R5_UPTODATE, &dev->flags) || 2576 test_bit(R5_Wantcompute, &dev->flags))) { 2577 if (test_bit(R5_Insync, &dev->flags)) 2578 rmw++; 2579 else 2580 rmw += 2*disks; /* cannot read it */ 2581 } 2582 /* Would I have to read this buffer for reconstruct_write */ 2583 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 2584 !test_bit(R5_LOCKED, &dev->flags) && 2585 !(test_bit(R5_UPTODATE, &dev->flags) || 2586 test_bit(R5_Wantcompute, &dev->flags))) { 2587 if (test_bit(R5_Insync, &dev->flags)) rcw++; 2588 else 2589 rcw += 2*disks; 2590 } 2591 } 2592 pr_debug("for sector %llu, rmw=%d rcw=%d\n", 2593 (unsigned long long)sh->sector, rmw, rcw); 2594 set_bit(STRIPE_HANDLE, &sh->state); 2595 if (rmw < rcw && rmw > 0) 2596 /* prefer read-modify-write, but need to get some data */ 2597 for (i = disks; i--; ) { 2598 struct r5dev *dev = &sh->dev[i]; 2599 if ((dev->towrite || i == sh->pd_idx) && 2600 !test_bit(R5_LOCKED, &dev->flags) && 2601 !(test_bit(R5_UPTODATE, &dev->flags) || 2602 test_bit(R5_Wantcompute, &dev->flags)) && 2603 test_bit(R5_Insync, &dev->flags)) { 2604 if ( 2605 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2606 pr_debug("Read_old block " 2607 "%d for r-m-w\n", i); 2608 set_bit(R5_LOCKED, &dev->flags); 2609 set_bit(R5_Wantread, &dev->flags); 2610 s->locked++; 2611 } else { 2612 set_bit(STRIPE_DELAYED, &sh->state); 2613 set_bit(STRIPE_HANDLE, &sh->state); 2614 } 2615 } 2616 } 2617 if (rcw <= rmw && rcw > 0) { 2618 /* want reconstruct write, but need to get some data */ 2619 rcw = 0; 2620 for (i = disks; i--; ) { 2621 struct r5dev *dev = &sh->dev[i]; 2622 if (!test_bit(R5_OVERWRITE, &dev->flags) && 2623 i != sh->pd_idx && i != sh->qd_idx && 2624 !test_bit(R5_LOCKED, &dev->flags) && 2625 !(test_bit(R5_UPTODATE, &dev->flags) || 2626 test_bit(R5_Wantcompute, &dev->flags))) { 2627 rcw++; 2628 if (!test_bit(R5_Insync, &dev->flags)) 2629 continue; /* it's a failed drive */ 2630 if ( 2631 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2632 pr_debug("Read_old block " 2633 "%d for Reconstruct\n", i); 2634 set_bit(R5_LOCKED, &dev->flags); 2635 set_bit(R5_Wantread, &dev->flags); 2636 s->locked++; 2637 } else { 2638 set_bit(STRIPE_DELAYED, &sh->state); 2639 set_bit(STRIPE_HANDLE, &sh->state); 2640 } 2641 } 2642 } 2643 } 2644 /* now if nothing is locked, and if we have enough data, 2645 * we can start a write request 2646 */ 2647 /* since handle_stripe can be called at any time we need to handle the 2648 * case where a compute block operation has been submitted and then a 2649 * subsequent call wants to start a write request. raid_run_ops only 2650 * handles the case where compute block and reconstruct are requested 2651 * simultaneously. If this is not the case then new writes need to be 2652 * held off until the compute completes. 2653 */ 2654 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && 2655 (s->locked == 0 && (rcw == 0 || rmw == 0) && 2656 !test_bit(STRIPE_BIT_DELAY, &sh->state))) 2657 schedule_reconstruction(sh, s, rcw == 0, 0); 2658} 2659 2660static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh, 2661 struct stripe_head_state *s, int disks) 2662{ 2663 struct r5dev *dev = NULL; 2664 2665 set_bit(STRIPE_HANDLE, &sh->state); 2666 2667 switch (sh->check_state) { 2668 case check_state_idle: 2669 /* start a new check operation if there are no failures */ 2670 if (s->failed == 0) { 2671 BUG_ON(s->uptodate != disks); 2672 sh->check_state = check_state_run; 2673 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2674 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); 2675 s->uptodate--; 2676 break; 2677 } 2678 dev = &sh->dev[s->failed_num[0]]; 2679 /* fall through */ 2680 case check_state_compute_result: 2681 sh->check_state = check_state_idle; 2682 if (!dev) 2683 dev = &sh->dev[sh->pd_idx]; 2684 2685 /* check that a write has not made the stripe insync */ 2686 if (test_bit(STRIPE_INSYNC, &sh->state)) 2687 break; 2688 2689 /* either failed parity check, or recovery is happening */ 2690 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); 2691 BUG_ON(s->uptodate != disks); 2692 2693 set_bit(R5_LOCKED, &dev->flags); 2694 s->locked++; 2695 set_bit(R5_Wantwrite, &dev->flags); 2696 2697 clear_bit(STRIPE_DEGRADED, &sh->state); 2698 set_bit(STRIPE_INSYNC, &sh->state); 2699 break; 2700 case check_state_run: 2701 break; /* we will be called again upon completion */ 2702 case check_state_check_result: 2703 sh->check_state = check_state_idle; 2704 2705 /* if a failure occurred during the check operation, leave 2706 * STRIPE_INSYNC not set and let the stripe be handled again 2707 */ 2708 if (s->failed) 2709 break; 2710 2711 /* handle a successful check operation, if parity is correct 2712 * we are done. Otherwise update the mismatch count and repair 2713 * parity if !MD_RECOVERY_CHECK 2714 */ 2715 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0) 2716 /* parity is correct (on disc, 2717 * not in buffer any more) 2718 */ 2719 set_bit(STRIPE_INSYNC, &sh->state); 2720 else { 2721 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2722 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2723 /* don't try to repair!! */ 2724 set_bit(STRIPE_INSYNC, &sh->state); 2725 else { 2726 sh->check_state = check_state_compute_run; 2727 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2728 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2729 set_bit(R5_Wantcompute, 2730 &sh->dev[sh->pd_idx].flags); 2731 sh->ops.target = sh->pd_idx; 2732 sh->ops.target2 = -1; 2733 s->uptodate++; 2734 } 2735 } 2736 break; 2737 case check_state_compute_run: 2738 break; 2739 default: 2740 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2741 __func__, sh->check_state, 2742 (unsigned long long) sh->sector); 2743 BUG(); 2744 } 2745} 2746 2747 2748static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh, 2749 struct stripe_head_state *s, 2750 int disks) 2751{ 2752 int pd_idx = sh->pd_idx; 2753 int qd_idx = sh->qd_idx; 2754 struct r5dev *dev; 2755 2756 set_bit(STRIPE_HANDLE, &sh->state); 2757 2758 BUG_ON(s->failed > 2); 2759 2760 /* Want to check and possibly repair P and Q. 2761 * However there could be one 'failed' device, in which 2762 * case we can only check one of them, possibly using the 2763 * other to generate missing data 2764 */ 2765 2766 switch (sh->check_state) { 2767 case check_state_idle: 2768 /* start a new check operation if there are < 2 failures */ 2769 if (s->failed == s->q_failed) { 2770 /* The only possible failed device holds Q, so it 2771 * makes sense to check P (If anything else were failed, 2772 * we would have used P to recreate it). 2773 */ 2774 sh->check_state = check_state_run; 2775 } 2776 if (!s->q_failed && s->failed < 2) { 2777 /* Q is not failed, and we didn't use it to generate 2778 * anything, so it makes sense to check it 2779 */ 2780 if (sh->check_state == check_state_run) 2781 sh->check_state = check_state_run_pq; 2782 else 2783 sh->check_state = check_state_run_q; 2784 } 2785 2786 /* discard potentially stale zero_sum_result */ 2787 sh->ops.zero_sum_result = 0; 2788 2789 if (sh->check_state == check_state_run) { 2790 /* async_xor_zero_sum destroys the contents of P */ 2791 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2792 s->uptodate--; 2793 } 2794 if (sh->check_state >= check_state_run && 2795 sh->check_state <= check_state_run_pq) { 2796 /* async_syndrome_zero_sum preserves P and Q, so 2797 * no need to mark them !uptodate here 2798 */ 2799 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2800 break; 2801 } 2802 2803 /* we have 2-disk failure */ 2804 BUG_ON(s->failed != 2); 2805 /* fall through */ 2806 case check_state_compute_result: 2807 sh->check_state = check_state_idle; 2808 2809 /* check that a write has not made the stripe insync */ 2810 if (test_bit(STRIPE_INSYNC, &sh->state)) 2811 break; 2812 2813 /* now write out any block on a failed drive, 2814 * or P or Q if they were recomputed 2815 */ 2816 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ 2817 if (s->failed == 2) { 2818 dev = &sh->dev[s->failed_num[1]]; 2819 s->locked++; 2820 set_bit(R5_LOCKED, &dev->flags); 2821 set_bit(R5_Wantwrite, &dev->flags); 2822 } 2823 if (s->failed >= 1) { 2824 dev = &sh->dev[s->failed_num[0]]; 2825 s->locked++; 2826 set_bit(R5_LOCKED, &dev->flags); 2827 set_bit(R5_Wantwrite, &dev->flags); 2828 } 2829 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2830 dev = &sh->dev[pd_idx]; 2831 s->locked++; 2832 set_bit(R5_LOCKED, &dev->flags); 2833 set_bit(R5_Wantwrite, &dev->flags); 2834 } 2835 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2836 dev = &sh->dev[qd_idx]; 2837 s->locked++; 2838 set_bit(R5_LOCKED, &dev->flags); 2839 set_bit(R5_Wantwrite, &dev->flags); 2840 } 2841 clear_bit(STRIPE_DEGRADED, &sh->state); 2842 2843 set_bit(STRIPE_INSYNC, &sh->state); 2844 break; 2845 case check_state_run: 2846 case check_state_run_q: 2847 case check_state_run_pq: 2848 break; /* we will be called again upon completion */ 2849 case check_state_check_result: 2850 sh->check_state = check_state_idle; 2851 2852 /* handle a successful check operation, if parity is correct 2853 * we are done. Otherwise update the mismatch count and repair 2854 * parity if !MD_RECOVERY_CHECK 2855 */ 2856 if (sh->ops.zero_sum_result == 0) { 2857 /* both parities are correct */ 2858 if (!s->failed) 2859 set_bit(STRIPE_INSYNC, &sh->state); 2860 else { 2861 /* in contrast to the raid5 case we can validate 2862 * parity, but still have a failure to write 2863 * back 2864 */ 2865 sh->check_state = check_state_compute_result; 2866 /* Returning at this point means that we may go 2867 * off and bring p and/or q uptodate again so 2868 * we make sure to check zero_sum_result again 2869 * to verify if p or q need writeback 2870 */ 2871 } 2872 } else { 2873 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2874 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2875 /* don't try to repair!! */ 2876 set_bit(STRIPE_INSYNC, &sh->state); 2877 else { 2878 int *target = &sh->ops.target; 2879 2880 sh->ops.target = -1; 2881 sh->ops.target2 = -1; 2882 sh->check_state = check_state_compute_run; 2883 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2884 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2885 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2886 set_bit(R5_Wantcompute, 2887 &sh->dev[pd_idx].flags); 2888 *target = pd_idx; 2889 target = &sh->ops.target2; 2890 s->uptodate++; 2891 } 2892 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2893 set_bit(R5_Wantcompute, 2894 &sh->dev[qd_idx].flags); 2895 *target = qd_idx; 2896 s->uptodate++; 2897 } 2898 } 2899 } 2900 break; 2901 case check_state_compute_run: 2902 break; 2903 default: 2904 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2905 __func__, sh->check_state, 2906 (unsigned long long) sh->sector); 2907 BUG(); 2908 } 2909} 2910 2911static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh) 2912{ 2913 int i; 2914 2915 /* We have read all the blocks in this stripe and now we need to 2916 * copy some of them into a target stripe for expand. 2917 */ 2918 struct dma_async_tx_descriptor *tx = NULL; 2919 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2920 for (i = 0; i < sh->disks; i++) 2921 if (i != sh->pd_idx && i != sh->qd_idx) { 2922 int dd_idx, j; 2923 struct stripe_head *sh2; 2924 struct async_submit_ctl submit; 2925 2926 sector_t bn = compute_blocknr(sh, i, 1); 2927 sector_t s = raid5_compute_sector(conf, bn, 0, 2928 &dd_idx, NULL); 2929 sh2 = get_active_stripe(conf, s, 0, 1, 1); 2930 if (sh2 == NULL) 2931 /* so far only the early blocks of this stripe 2932 * have been requested. When later blocks 2933 * get requested, we will try again 2934 */ 2935 continue; 2936 if (!test_bit(STRIPE_EXPANDING, &sh2->state) || 2937 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { 2938 /* must have already done this block */ 2939 release_stripe(sh2); 2940 continue; 2941 } 2942 2943 /* place all the copies on one channel */ 2944 init_async_submit(&submit, 0, tx, NULL, NULL, NULL); 2945 tx = async_memcpy(sh2->dev[dd_idx].page, 2946 sh->dev[i].page, 0, 0, STRIPE_SIZE, 2947 &submit); 2948 2949 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); 2950 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); 2951 for (j = 0; j < conf->raid_disks; j++) 2952 if (j != sh2->pd_idx && 2953 j != sh2->qd_idx && 2954 !test_bit(R5_Expanded, &sh2->dev[j].flags)) 2955 break; 2956 if (j == conf->raid_disks) { 2957 set_bit(STRIPE_EXPAND_READY, &sh2->state); 2958 set_bit(STRIPE_HANDLE, &sh2->state); 2959 } 2960 release_stripe(sh2); 2961 2962 } 2963 /* done submitting copies, wait for them to complete */ 2964 if (tx) { 2965 async_tx_ack(tx); 2966 dma_wait_for_async_tx(tx); 2967 } 2968} 2969 2970 2971/* 2972 * handle_stripe - do things to a stripe. 2973 * 2974 * We lock the stripe and then examine the state of various bits 2975 * to see what needs to be done. 2976 * Possible results: 2977 * return some read request which now have data 2978 * return some write requests which are safely on disc 2979 * schedule a read on some buffers 2980 * schedule a write of some buffers 2981 * return confirmation of parity correctness 2982 * 2983 * buffers are taken off read_list or write_list, and bh_cache buffers 2984 * get BH_Lock set before the stripe lock is released. 2985 * 2986 */ 2987 2988static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) 2989{ 2990 struct r5conf *conf = sh->raid_conf; 2991 int disks = sh->disks; 2992 struct r5dev *dev; 2993 int i; 2994 2995 memset(s, 0, sizeof(*s)); 2996 2997 s->syncing = test_bit(STRIPE_SYNCING, &sh->state); 2998 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2999 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); 3000 s->failed_num[0] = -1; 3001 s->failed_num[1] = -1; 3002 3003 /* Now to look around and see what can be done */ 3004 rcu_read_lock(); 3005 spin_lock_irq(&conf->device_lock); 3006 for (i=disks; i--; ) { 3007 struct md_rdev *rdev; 3008 sector_t first_bad; 3009 int bad_sectors; 3010 int is_bad = 0; 3011 3012 dev = &sh->dev[i]; 3013 3014 pr_debug("check %d: state 0x%lx read %p write %p written %p\n", 3015 i, dev->flags, dev->toread, dev->towrite, dev->written); 3016 /* maybe we can reply to a read 3017 * 3018 * new wantfill requests are only permitted while 3019 * ops_complete_biofill is guaranteed to be inactive 3020 */ 3021 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && 3022 !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) 3023 set_bit(R5_Wantfill, &dev->flags); 3024 3025 /* now count some things */ 3026 if (test_bit(R5_LOCKED, &dev->flags)) 3027 s->locked++; 3028 if (test_bit(R5_UPTODATE, &dev->flags)) 3029 s->uptodate++; 3030 if (test_bit(R5_Wantcompute, &dev->flags)) { 3031 s->compute++; 3032 BUG_ON(s->compute > 2); 3033 } 3034 3035 if (test_bit(R5_Wantfill, &dev->flags)) 3036 s->to_fill++; 3037 else if (dev->toread) 3038 s->to_read++; 3039 if (dev->towrite) { 3040 s->to_write++; 3041 if (!test_bit(R5_OVERWRITE, &dev->flags)) 3042 s->non_overwrite++; 3043 } 3044 if (dev->written) 3045 s->written++; 3046 rdev = rcu_dereference(conf->disks[i].rdev); 3047 if (rdev && test_bit(Faulty, &rdev->flags)) 3048 rdev = NULL; 3049 if (rdev) { 3050 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 3051 &first_bad, &bad_sectors); 3052 if (s->blocked_rdev == NULL 3053 && (test_bit(Blocked, &rdev->flags) 3054 || is_bad < 0)) { 3055 if (is_bad < 0) 3056 set_bit(BlockedBadBlocks, 3057 &rdev->flags); 3058 s->blocked_rdev = rdev; 3059 atomic_inc(&rdev->nr_pending); 3060 } 3061 } 3062 clear_bit(R5_Insync, &dev->flags); 3063 if (!rdev) 3064 /* Not in-sync */; 3065 else if (is_bad) { 3066 /* also not in-sync */ 3067 if (!test_bit(WriteErrorSeen, &rdev->flags)) { 3068 /* treat as in-sync, but with a read error 3069 * which we can now try to correct 3070 */ 3071 set_bit(R5_Insync, &dev->flags); 3072 set_bit(R5_ReadError, &dev->flags); 3073 } 3074 } else if (test_bit(In_sync, &rdev->flags)) 3075 set_bit(R5_Insync, &dev->flags); 3076 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) 3077 /* in sync if before recovery_offset */ 3078 set_bit(R5_Insync, &dev->flags); 3079 else if (test_bit(R5_UPTODATE, &dev->flags) && 3080 test_bit(R5_Expanded, &dev->flags)) 3081 /* If we've reshaped into here, we assume it is Insync. 3082 * We will shortly update recovery_offset to make 3083 * it official. 3084 */ 3085 set_bit(R5_Insync, &dev->flags); 3086 3087 if (rdev && test_bit(R5_WriteError, &dev->flags)) { 3088 clear_bit(R5_Insync, &dev->flags); 3089 if (!test_bit(Faulty, &rdev->flags)) { 3090 s->handle_bad_blocks = 1; 3091 atomic_inc(&rdev->nr_pending); 3092 } else 3093 clear_bit(R5_WriteError, &dev->flags); 3094 } 3095 if (rdev && test_bit(R5_MadeGood, &dev->flags)) { 3096 if (!test_bit(Faulty, &rdev->flags)) { 3097 s->handle_bad_blocks = 1; 3098 atomic_inc(&rdev->nr_pending); 3099 } else 3100 clear_bit(R5_MadeGood, &dev->flags); 3101 } 3102 if (!test_bit(R5_Insync, &dev->flags)) { 3103 /* The ReadError flag will just be confusing now */ 3104 clear_bit(R5_ReadError, &dev->flags); 3105 clear_bit(R5_ReWrite, &dev->flags); 3106 } 3107 if (test_bit(R5_ReadError, &dev->flags)) 3108 clear_bit(R5_Insync, &dev->flags); 3109 if (!test_bit(R5_Insync, &dev->flags)) { 3110 if (s->failed < 2) 3111 s->failed_num[s->failed] = i; 3112 s->failed++; 3113 } 3114 } 3115 spin_unlock_irq(&conf->device_lock); 3116 rcu_read_unlock(); 3117} 3118 3119static void handle_stripe(struct stripe_head *sh) 3120{ 3121 struct stripe_head_state s; 3122 struct r5conf *conf = sh->raid_conf; 3123 int i; 3124 int prexor; 3125 int disks = sh->disks; 3126 struct r5dev *pdev, *qdev; 3127 3128 clear_bit(STRIPE_HANDLE, &sh->state); 3129 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) { 3130 /* already being handled, ensure it gets handled 3131 * again when current action finishes */ 3132 set_bit(STRIPE_HANDLE, &sh->state); 3133 return; 3134 } 3135 3136 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { 3137 set_bit(STRIPE_SYNCING, &sh->state); 3138 clear_bit(STRIPE_INSYNC, &sh->state); 3139 } 3140 clear_bit(STRIPE_DELAYED, &sh->state); 3141 3142 pr_debug("handling stripe %llu, state=%#lx cnt=%d, " 3143 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", 3144 (unsigned long long)sh->sector, sh->state, 3145 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, 3146 sh->check_state, sh->reconstruct_state); 3147 3148 analyse_stripe(sh, &s); 3149 3150 if (s.handle_bad_blocks) { 3151 set_bit(STRIPE_HANDLE, &sh->state); 3152 goto finish; 3153 } 3154 3155 if (unlikely(s.blocked_rdev)) { 3156 if (s.syncing || s.expanding || s.expanded || 3157 s.to_write || s.written) { 3158 set_bit(STRIPE_HANDLE, &sh->state); 3159 goto finish; 3160 } 3161 /* There is nothing for the blocked_rdev to block */ 3162 rdev_dec_pending(s.blocked_rdev, conf->mddev); 3163 s.blocked_rdev = NULL; 3164 } 3165 3166 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { 3167 set_bit(STRIPE_OP_BIOFILL, &s.ops_request); 3168 set_bit(STRIPE_BIOFILL_RUN, &sh->state); 3169 } 3170 3171 pr_debug("locked=%d uptodate=%d to_read=%d" 3172 " to_write=%d failed=%d failed_num=%d,%d\n", 3173 s.locked, s.uptodate, s.to_read, s.to_write, s.failed, 3174 s.failed_num[0], s.failed_num[1]); 3175 /* check if the array has lost more than max_degraded devices and, 3176 * if so, some requests might need to be failed. 3177 */ 3178 if (s.failed > conf->max_degraded) { 3179 sh->check_state = 0; 3180 sh->reconstruct_state = 0; 3181 if (s.to_read+s.to_write+s.written) 3182 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi); 3183 if (s.syncing) 3184 handle_failed_sync(conf, sh, &s); 3185 } 3186 3187 /* 3188 * might be able to return some write requests if the parity blocks 3189 * are safe, or on a failed drive 3190 */ 3191 pdev = &sh->dev[sh->pd_idx]; 3192 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx) 3193 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx); 3194 qdev = &sh->dev[sh->qd_idx]; 3195 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx) 3196 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx) 3197 || conf->level < 6; 3198 3199 if (s.written && 3200 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags) 3201 && !test_bit(R5_LOCKED, &pdev->flags) 3202 && test_bit(R5_UPTODATE, &pdev->flags)))) && 3203 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags) 3204 && !test_bit(R5_LOCKED, &qdev->flags) 3205 && test_bit(R5_UPTODATE, &qdev->flags))))) 3206 handle_stripe_clean_event(conf, sh, disks, &s.return_bi); 3207 3208 /* Now we might consider reading some blocks, either to check/generate 3209 * parity, or to satisfy requests 3210 * or to load a block that is being partially written. 3211 */ 3212 if (s.to_read || s.non_overwrite 3213 || (conf->level == 6 && s.to_write && s.failed) 3214 || (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) 3215 handle_stripe_fill(sh, &s, disks); 3216 3217 /* Now we check to see if any write operations have recently 3218 * completed 3219 */ 3220 prexor = 0; 3221 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) 3222 prexor = 1; 3223 if (sh->reconstruct_state == reconstruct_state_drain_result || 3224 sh->reconstruct_state == reconstruct_state_prexor_drain_result) { 3225 sh->reconstruct_state = reconstruct_state_idle; 3226 3227 /* All the 'written' buffers and the parity block are ready to 3228 * be written back to disk 3229 */ 3230 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); 3231 BUG_ON(sh->qd_idx >= 0 && 3232 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags)); 3233 for (i = disks; i--; ) { 3234 struct r5dev *dev = &sh->dev[i]; 3235 if (test_bit(R5_LOCKED, &dev->flags) && 3236 (i == sh->pd_idx || i == sh->qd_idx || 3237 dev->written)) { 3238 pr_debug("Writing block %d\n", i); 3239 set_bit(R5_Wantwrite, &dev->flags); 3240 if (prexor) 3241 continue; 3242 if (!test_bit(R5_Insync, &dev->flags) || 3243 ((i == sh->pd_idx || i == sh->qd_idx) && 3244 s.failed == 0)) 3245 set_bit(STRIPE_INSYNC, &sh->state); 3246 } 3247 } 3248 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3249 s.dec_preread_active = 1; 3250 } 3251 3252 /* Now to consider new write requests and what else, if anything 3253 * should be read. We do not handle new writes when: 3254 * 1/ A 'write' operation (copy+xor) is already in flight. 3255 * 2/ A 'check' operation is in flight, as it may clobber the parity 3256 * block. 3257 */ 3258 if (s.to_write && !sh->reconstruct_state && !sh->check_state) 3259 handle_stripe_dirtying(conf, sh, &s, disks); 3260 3261 /* maybe we need to check and possibly fix the parity for this stripe 3262 * Any reads will already have been scheduled, so we just see if enough 3263 * data is available. The parity check is held off while parity 3264 * dependent operations are in flight. 3265 */ 3266 if (sh->check_state || 3267 (s.syncing && s.locked == 0 && 3268 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && 3269 !test_bit(STRIPE_INSYNC, &sh->state))) { 3270 if (conf->level == 6) 3271 handle_parity_checks6(conf, sh, &s, disks); 3272 else 3273 handle_parity_checks5(conf, sh, &s, disks); 3274 } 3275 3276 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { 3277 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3278 clear_bit(STRIPE_SYNCING, &sh->state); 3279 } 3280 3281 /* If the failed drives are just a ReadError, then we might need 3282 * to progress the repair/check process 3283 */ 3284 if (s.failed <= conf->max_degraded && !conf->mddev->ro) 3285 for (i = 0; i < s.failed; i++) { 3286 struct r5dev *dev = &sh->dev[s.failed_num[i]]; 3287 if (test_bit(R5_ReadError, &dev->flags) 3288 && !test_bit(R5_LOCKED, &dev->flags) 3289 && test_bit(R5_UPTODATE, &dev->flags) 3290 ) { 3291 if (!test_bit(R5_ReWrite, &dev->flags)) { 3292 set_bit(R5_Wantwrite, &dev->flags); 3293 set_bit(R5_ReWrite, &dev->flags); 3294 set_bit(R5_LOCKED, &dev->flags); 3295 s.locked++; 3296 } else { 3297 /* let's read it back */ 3298 set_bit(R5_Wantread, &dev->flags); 3299 set_bit(R5_LOCKED, &dev->flags); 3300 s.locked++; 3301 } 3302 } 3303 } 3304 3305 3306 /* Finish reconstruct operations initiated by the expansion process */ 3307 if (sh->reconstruct_state == reconstruct_state_result) { 3308 struct stripe_head *sh_src 3309 = get_active_stripe(conf, sh->sector, 1, 1, 1); 3310 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) { 3311 /* sh cannot be written until sh_src has been read. 3312 * so arrange for sh to be delayed a little 3313 */ 3314 set_bit(STRIPE_DELAYED, &sh->state); 3315 set_bit(STRIPE_HANDLE, &sh->state); 3316 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, 3317 &sh_src->state)) 3318 atomic_inc(&conf->preread_active_stripes); 3319 release_stripe(sh_src); 3320 goto finish; 3321 } 3322 if (sh_src) 3323 release_stripe(sh_src); 3324 3325 sh->reconstruct_state = reconstruct_state_idle; 3326 clear_bit(STRIPE_EXPANDING, &sh->state); 3327 for (i = conf->raid_disks; i--; ) { 3328 set_bit(R5_Wantwrite, &sh->dev[i].flags); 3329 set_bit(R5_LOCKED, &sh->dev[i].flags); 3330 s.locked++; 3331 } 3332 } 3333 3334 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && 3335 !sh->reconstruct_state) { 3336 /* Need to write out all blocks after computing parity */ 3337 sh->disks = conf->raid_disks; 3338 stripe_set_idx(sh->sector, conf, 0, sh); 3339 schedule_reconstruction(sh, &s, 1, 1); 3340 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { 3341 clear_bit(STRIPE_EXPAND_READY, &sh->state); 3342 atomic_dec(&conf->reshape_stripes); 3343 wake_up(&conf->wait_for_overlap); 3344 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3345 } 3346 3347 if (s.expanding && s.locked == 0 && 3348 !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) 3349 handle_stripe_expansion(conf, sh); 3350 3351finish: 3352 /* wait for this device to become unblocked */ 3353 if (conf->mddev->external && unlikely(s.blocked_rdev)) 3354 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev); 3355 3356 if (s.handle_bad_blocks) 3357 for (i = disks; i--; ) { 3358 struct md_rdev *rdev; 3359 struct r5dev *dev = &sh->dev[i]; 3360 if (test_and_clear_bit(R5_WriteError, &dev->flags)) { 3361 /* We own a safe reference to the rdev */ 3362 rdev = conf->disks[i].rdev; 3363 if (!rdev_set_badblocks(rdev, sh->sector, 3364 STRIPE_SECTORS, 0)) 3365 md_error(conf->mddev, rdev); 3366 rdev_dec_pending(rdev, conf->mddev); 3367 } 3368 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) { 3369 rdev = conf->disks[i].rdev; 3370 rdev_clear_badblocks(rdev, sh->sector, 3371 STRIPE_SECTORS); 3372 rdev_dec_pending(rdev, conf->mddev); 3373 } 3374 } 3375 3376 if (s.ops_request) 3377 raid_run_ops(sh, s.ops_request); 3378 3379 ops_run_io(sh, &s); 3380 3381 if (s.dec_preread_active) { 3382 /* We delay this until after ops_run_io so that if make_request 3383 * is waiting on a flush, it won't continue until the writes 3384 * have actually been submitted. 3385 */ 3386 atomic_dec(&conf->preread_active_stripes); 3387 if (atomic_read(&conf->preread_active_stripes) < 3388 IO_THRESHOLD) 3389 md_wakeup_thread(conf->mddev->thread); 3390 } 3391 3392 return_io(s.return_bi); 3393 3394 clear_bit_unlock(STRIPE_ACTIVE, &sh->state); 3395} 3396 3397static void raid5_activate_delayed(struct r5conf *conf) 3398{ 3399 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 3400 while (!list_empty(&conf->delayed_list)) { 3401 struct list_head *l = conf->delayed_list.next; 3402 struct stripe_head *sh; 3403 sh = list_entry(l, struct stripe_head, lru); 3404 list_del_init(l); 3405 clear_bit(STRIPE_DELAYED, &sh->state); 3406 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3407 atomic_inc(&conf->preread_active_stripes); 3408 list_add_tail(&sh->lru, &conf->hold_list); 3409 } 3410 } 3411} 3412 3413static void activate_bit_delay(struct r5conf *conf) 3414{ 3415 /* device_lock is held */ 3416 struct list_head head; 3417 list_add(&head, &conf->bitmap_list); 3418 list_del_init(&conf->bitmap_list); 3419 while (!list_empty(&head)) { 3420 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); 3421 list_del_init(&sh->lru); 3422 atomic_inc(&sh->count); 3423 __release_stripe(conf, sh); 3424 } 3425} 3426 3427int md_raid5_congested(struct mddev *mddev, int bits) 3428{ 3429 struct r5conf *conf = mddev->private; 3430 3431 /* No difference between reads and writes. Just check 3432 * how busy the stripe_cache is 3433 */ 3434 3435 if (conf->inactive_blocked) 3436 return 1; 3437 if (conf->quiesce) 3438 return 1; 3439 if (list_empty_careful(&conf->inactive_list)) 3440 return 1; 3441 3442 return 0; 3443} 3444EXPORT_SYMBOL_GPL(md_raid5_congested); 3445 3446static int raid5_congested(void *data, int bits) 3447{ 3448 struct mddev *mddev = data; 3449 3450 return mddev_congested(mddev, bits) || 3451 md_raid5_congested(mddev, bits); 3452} 3453 3454/* We want read requests to align with chunks where possible, 3455 * but write requests don't need to. 3456 */ 3457static int raid5_mergeable_bvec(struct request_queue *q, 3458 struct bvec_merge_data *bvm, 3459 struct bio_vec *biovec) 3460{ 3461 struct mddev *mddev = q->queuedata; 3462 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 3463 int max; 3464 unsigned int chunk_sectors = mddev->chunk_sectors; 3465 unsigned int bio_sectors = bvm->bi_size >> 9; 3466 3467 if ((bvm->bi_rw & 1) == WRITE) 3468 return biovec->bv_len; /* always allow writes to be mergeable */ 3469 3470 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3471 chunk_sectors = mddev->new_chunk_sectors; 3472 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; 3473 if (max < 0) max = 0; 3474 if (max <= biovec->bv_len && bio_sectors == 0) 3475 return biovec->bv_len; 3476 else 3477 return max; 3478} 3479 3480 3481static int in_chunk_boundary(struct mddev *mddev, struct bio *bio) 3482{ 3483 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); 3484 unsigned int chunk_sectors = mddev->chunk_sectors; 3485 unsigned int bio_sectors = bio->bi_size >> 9; 3486 3487 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3488 chunk_sectors = mddev->new_chunk_sectors; 3489 return chunk_sectors >= 3490 ((sector & (chunk_sectors - 1)) + bio_sectors); 3491} 3492 3493/* 3494 * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) 3495 * later sampled by raid5d. 3496 */ 3497static void add_bio_to_retry(struct bio *bi,struct r5conf *conf) 3498{ 3499 unsigned long flags; 3500 3501 spin_lock_irqsave(&conf->device_lock, flags); 3502 3503 bi->bi_next = conf->retry_read_aligned_list; 3504 conf->retry_read_aligned_list = bi; 3505 3506 spin_unlock_irqrestore(&conf->device_lock, flags); 3507 md_wakeup_thread(conf->mddev->thread); 3508} 3509 3510 3511static struct bio *remove_bio_from_retry(struct r5conf *conf) 3512{ 3513 struct bio *bi; 3514 3515 bi = conf->retry_read_aligned; 3516 if (bi) { 3517 conf->retry_read_aligned = NULL; 3518 return bi; 3519 } 3520 bi = conf->retry_read_aligned_list; 3521 if(bi) { 3522 conf->retry_read_aligned_list = bi->bi_next; 3523 bi->bi_next = NULL; 3524 /* 3525 * this sets the active strip count to 1 and the processed 3526 * strip count to zero (upper 8 bits) 3527 */ 3528 bi->bi_phys_segments = 1; /* biased count of active stripes */ 3529 } 3530 3531 return bi; 3532} 3533 3534 3535/* 3536 * The "raid5_align_endio" should check if the read succeeded and if it 3537 * did, call bio_endio on the original bio (having bio_put the new bio 3538 * first). 3539 * If the read failed.. 3540 */ 3541static void raid5_align_endio(struct bio *bi, int error) 3542{ 3543 struct bio* raid_bi = bi->bi_private; 3544 struct mddev *mddev; 3545 struct r5conf *conf; 3546 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 3547 struct md_rdev *rdev; 3548 3549 bio_put(bi); 3550 3551 rdev = (void*)raid_bi->bi_next; 3552 raid_bi->bi_next = NULL; 3553 mddev = rdev->mddev; 3554 conf = mddev->private; 3555 3556 rdev_dec_pending(rdev, conf->mddev); 3557 3558 if (!error && uptodate) { 3559 bio_endio(raid_bi, 0); 3560 if (atomic_dec_and_test(&conf->active_aligned_reads)) 3561 wake_up(&conf->wait_for_stripe); 3562 return; 3563 } 3564 3565 3566 pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); 3567 3568 add_bio_to_retry(raid_bi, conf); 3569} 3570 3571static int bio_fits_rdev(struct bio *bi) 3572{ 3573 struct request_queue *q = bdev_get_queue(bi->bi_bdev); 3574 3575 if ((bi->bi_size>>9) > queue_max_sectors(q)) 3576 return 0; 3577 blk_recount_segments(q, bi); 3578 if (bi->bi_phys_segments > queue_max_segments(q)) 3579 return 0; 3580 3581 if (q->merge_bvec_fn) 3582 /* it's too hard to apply the merge_bvec_fn at this stage, 3583 * just just give up 3584 */ 3585 return 0; 3586 3587 return 1; 3588} 3589 3590 3591static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio) 3592{ 3593 struct r5conf *conf = mddev->private; 3594 int dd_idx; 3595 struct bio* align_bi; 3596 struct md_rdev *rdev; 3597 sector_t end_sector; 3598 3599 if (!in_chunk_boundary(mddev, raid_bio)) { 3600 pr_debug("chunk_aligned_read : non aligned\n"); 3601 return 0; 3602 } 3603 /* 3604 * use bio_clone_mddev to make a copy of the bio 3605 */ 3606 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev); 3607 if (!align_bi) 3608 return 0; 3609 /* 3610 * set bi_end_io to a new function, and set bi_private to the 3611 * original bio. 3612 */ 3613 align_bi->bi_end_io = raid5_align_endio; 3614 align_bi->bi_private = raid_bio; 3615 /* 3616 * compute position 3617 */ 3618 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, 3619 0, 3620 &dd_idx, NULL); 3621 3622 end_sector = align_bi->bi_sector + (align_bi->bi_size >> 9); 3623 rcu_read_lock(); 3624 rdev = rcu_dereference(conf->disks[dd_idx].replacement); 3625 if (!rdev || test_bit(Faulty, &rdev->flags) || 3626 rdev->recovery_offset < end_sector) { 3627 rdev = rcu_dereference(conf->disks[dd_idx].rdev); 3628 if (rdev && 3629 (test_bit(Faulty, &rdev->flags) || 3630 !(test_bit(In_sync, &rdev->flags) || 3631 rdev->recovery_offset >= end_sector))) 3632 rdev = NULL; 3633 } 3634 if (rdev) { 3635 sector_t first_bad; 3636 int bad_sectors; 3637 3638 atomic_inc(&rdev->nr_pending); 3639 rcu_read_unlock(); 3640 raid_bio->bi_next = (void*)rdev; 3641 align_bi->bi_bdev = rdev->bdev; 3642 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); 3643 align_bi->bi_sector += rdev->data_offset; 3644 3645 if (!bio_fits_rdev(align_bi) || 3646 is_badblock(rdev, align_bi->bi_sector, align_bi->bi_size>>9, 3647 &first_bad, &bad_sectors)) { 3648 /* too big in some way, or has a known bad block */ 3649 bio_put(align_bi); 3650 rdev_dec_pending(rdev, mddev); 3651 return 0; 3652 } 3653 3654 spin_lock_irq(&conf->device_lock); 3655 wait_event_lock_irq(conf->wait_for_stripe, 3656 conf->quiesce == 0, 3657 conf->device_lock, /* nothing */); 3658 atomic_inc(&conf->active_aligned_reads); 3659 spin_unlock_irq(&conf->device_lock); 3660 3661 generic_make_request(align_bi); 3662 return 1; 3663 } else { 3664 rcu_read_unlock(); 3665 bio_put(align_bi); 3666 return 0; 3667 } 3668} 3669 3670/* __get_priority_stripe - get the next stripe to process 3671 * 3672 * Full stripe writes are allowed to pass preread active stripes up until 3673 * the bypass_threshold is exceeded. In general the bypass_count 3674 * increments when the handle_list is handled before the hold_list; however, it 3675 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a 3676 * stripe with in flight i/o. The bypass_count will be reset when the 3677 * head of the hold_list has changed, i.e. the head was promoted to the 3678 * handle_list. 3679 */ 3680static struct stripe_head *__get_priority_stripe(struct r5conf *conf) 3681{ 3682 struct stripe_head *sh; 3683 3684 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", 3685 __func__, 3686 list_empty(&conf->handle_list) ? "empty" : "busy", 3687 list_empty(&conf->hold_list) ? "empty" : "busy", 3688 atomic_read(&conf->pending_full_writes), conf->bypass_count); 3689 3690 if (!list_empty(&conf->handle_list)) { 3691 sh = list_entry(conf->handle_list.next, typeof(*sh), lru); 3692 3693 if (list_empty(&conf->hold_list)) 3694 conf->bypass_count = 0; 3695 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { 3696 if (conf->hold_list.next == conf->last_hold) 3697 conf->bypass_count++; 3698 else { 3699 conf->last_hold = conf->hold_list.next; 3700 conf->bypass_count -= conf->bypass_threshold; 3701 if (conf->bypass_count < 0) 3702 conf->bypass_count = 0; 3703 } 3704 } 3705 } else if (!list_empty(&conf->hold_list) && 3706 ((conf->bypass_threshold && 3707 conf->bypass_count > conf->bypass_threshold) || 3708 atomic_read(&conf->pending_full_writes) == 0)) { 3709 sh = list_entry(conf->hold_list.next, 3710 typeof(*sh), lru); 3711 conf->bypass_count -= conf->bypass_threshold; 3712 if (conf->bypass_count < 0) 3713 conf->bypass_count = 0; 3714 } else 3715 return NULL; 3716 3717 list_del_init(&sh->lru); 3718 atomic_inc(&sh->count); 3719 BUG_ON(atomic_read(&sh->count) != 1); 3720 return sh; 3721} 3722 3723static void make_request(struct mddev *mddev, struct bio * bi) 3724{ 3725 struct r5conf *conf = mddev->private; 3726 int dd_idx; 3727 sector_t new_sector; 3728 sector_t logical_sector, last_sector; 3729 struct stripe_head *sh; 3730 const int rw = bio_data_dir(bi); 3731 int remaining; 3732 int plugged; 3733 3734 if (unlikely(bi->bi_rw & REQ_FLUSH)) { 3735 md_flush_request(mddev, bi); 3736 return; 3737 } 3738 3739 md_write_start(mddev, bi); 3740 3741 if (rw == READ && 3742 mddev->reshape_position == MaxSector && 3743 chunk_aligned_read(mddev,bi)) 3744 return; 3745 3746 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 3747 last_sector = bi->bi_sector + (bi->bi_size>>9); 3748 bi->bi_next = NULL; 3749 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ 3750 3751 plugged = mddev_check_plugged(mddev); 3752 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 3753 DEFINE_WAIT(w); 3754 int disks, data_disks; 3755 int previous; 3756 3757 retry: 3758 previous = 0; 3759 disks = conf->raid_disks; 3760 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 3761 if (unlikely(conf->reshape_progress != MaxSector)) { 3762 /* spinlock is needed as reshape_progress may be 3763 * 64bit on a 32bit platform, and so it might be 3764 * possible to see a half-updated value 3765 * Of course reshape_progress could change after 3766 * the lock is dropped, so once we get a reference 3767 * to the stripe that we think it is, we will have 3768 * to check again. 3769 */ 3770 spin_lock_irq(&conf->device_lock); 3771 if (mddev->delta_disks < 0 3772 ? logical_sector < conf->reshape_progress 3773 : logical_sector >= conf->reshape_progress) { 3774 disks = conf->previous_raid_disks; 3775 previous = 1; 3776 } else { 3777 if (mddev->delta_disks < 0 3778 ? logical_sector < conf->reshape_safe 3779 : logical_sector >= conf->reshape_safe) { 3780 spin_unlock_irq(&conf->device_lock); 3781 schedule(); 3782 goto retry; 3783 } 3784 } 3785 spin_unlock_irq(&conf->device_lock); 3786 } 3787 data_disks = disks - conf->max_degraded; 3788 3789 new_sector = raid5_compute_sector(conf, logical_sector, 3790 previous, 3791 &dd_idx, NULL); 3792 pr_debug("raid456: make_request, sector %llu logical %llu\n", 3793 (unsigned long long)new_sector, 3794 (unsigned long long)logical_sector); 3795 3796 sh = get_active_stripe(conf, new_sector, previous, 3797 (bi->bi_rw&RWA_MASK), 0); 3798 if (sh) { 3799 if (unlikely(previous)) { 3800 /* expansion might have moved on while waiting for a 3801 * stripe, so we must do the range check again. 3802 * Expansion could still move past after this 3803 * test, but as we are holding a reference to 3804 * 'sh', we know that if that happens, 3805 * STRIPE_EXPANDING will get set and the expansion 3806 * won't proceed until we finish with the stripe. 3807 */ 3808 int must_retry = 0; 3809 spin_lock_irq(&conf->device_lock); 3810 if (mddev->delta_disks < 0 3811 ? logical_sector >= conf->reshape_progress 3812 : logical_sector < conf->reshape_progress) 3813 /* mismatch, need to try again */ 3814 must_retry = 1; 3815 spin_unlock_irq(&conf->device_lock); 3816 if (must_retry) { 3817 release_stripe(sh); 3818 schedule(); 3819 goto retry; 3820 } 3821 } 3822 3823 if (rw == WRITE && 3824 logical_sector >= mddev->suspend_lo && 3825 logical_sector < mddev->suspend_hi) { 3826 release_stripe(sh); 3827 /* As the suspend_* range is controlled by 3828 * userspace, we want an interruptible 3829 * wait. 3830 */ 3831 flush_signals(current); 3832 prepare_to_wait(&conf->wait_for_overlap, 3833 &w, TASK_INTERRUPTIBLE); 3834 if (logical_sector >= mddev->suspend_lo && 3835 logical_sector < mddev->suspend_hi) 3836 schedule(); 3837 goto retry; 3838 } 3839 3840 if (test_bit(STRIPE_EXPANDING, &sh->state) || 3841 !add_stripe_bio(sh, bi, dd_idx, rw)) { 3842 /* Stripe is busy expanding or 3843 * add failed due to overlap. Flush everything 3844 * and wait a while 3845 */ 3846 md_wakeup_thread(mddev->thread); 3847 release_stripe(sh); 3848 schedule(); 3849 goto retry; 3850 } 3851 finish_wait(&conf->wait_for_overlap, &w); 3852 set_bit(STRIPE_HANDLE, &sh->state); 3853 clear_bit(STRIPE_DELAYED, &sh->state); 3854 if ((bi->bi_rw & REQ_SYNC) && 3855 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3856 atomic_inc(&conf->preread_active_stripes); 3857 release_stripe(sh); 3858 } else { 3859 /* cannot get stripe for read-ahead, just give-up */ 3860 clear_bit(BIO_UPTODATE, &bi->bi_flags); 3861 finish_wait(&conf->wait_for_overlap, &w); 3862 break; 3863 } 3864 3865 } 3866 if (!plugged) 3867 md_wakeup_thread(mddev->thread); 3868 3869 spin_lock_irq(&conf->device_lock); 3870 remaining = raid5_dec_bi_phys_segments(bi); 3871 spin_unlock_irq(&conf->device_lock); 3872 if (remaining == 0) { 3873 3874 if ( rw == WRITE ) 3875 md_write_end(mddev); 3876 3877 bio_endio(bi, 0); 3878 } 3879} 3880 3881static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks); 3882 3883static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped) 3884{ 3885 /* reshaping is quite different to recovery/resync so it is 3886 * handled quite separately ... here. 3887 * 3888 * On each call to sync_request, we gather one chunk worth of 3889 * destination stripes and flag them as expanding. 3890 * Then we find all the source stripes and request reads. 3891 * As the reads complete, handle_stripe will copy the data 3892 * into the destination stripe and release that stripe. 3893 */ 3894 struct r5conf *conf = mddev->private; 3895 struct stripe_head *sh; 3896 sector_t first_sector, last_sector; 3897 int raid_disks = conf->previous_raid_disks; 3898 int data_disks = raid_disks - conf->max_degraded; 3899 int new_data_disks = conf->raid_disks - conf->max_degraded; 3900 int i; 3901 int dd_idx; 3902 sector_t writepos, readpos, safepos; 3903 sector_t stripe_addr; 3904 int reshape_sectors; 3905 struct list_head stripes; 3906 3907 if (sector_nr == 0) { 3908 /* If restarting in the middle, skip the initial sectors */ 3909 if (mddev->delta_disks < 0 && 3910 conf->reshape_progress < raid5_size(mddev, 0, 0)) { 3911 sector_nr = raid5_size(mddev, 0, 0) 3912 - conf->reshape_progress; 3913 } else if (mddev->delta_disks >= 0 && 3914 conf->reshape_progress > 0) 3915 sector_nr = conf->reshape_progress; 3916 sector_div(sector_nr, new_data_disks); 3917 if (sector_nr) { 3918 mddev->curr_resync_completed = sector_nr; 3919 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3920 *skipped = 1; 3921 return sector_nr; 3922 } 3923 } 3924 3925 /* We need to process a full chunk at a time. 3926 * If old and new chunk sizes differ, we need to process the 3927 * largest of these 3928 */ 3929 if (mddev->new_chunk_sectors > mddev->chunk_sectors) 3930 reshape_sectors = mddev->new_chunk_sectors; 3931 else 3932 reshape_sectors = mddev->chunk_sectors; 3933 3934 /* we update the metadata when there is more than 3Meg 3935 * in the block range (that is rather arbitrary, should 3936 * probably be time based) or when the data about to be 3937 * copied would over-write the source of the data at 3938 * the front of the range. 3939 * i.e. one new_stripe along from reshape_progress new_maps 3940 * to after where reshape_safe old_maps to 3941 */ 3942 writepos = conf->reshape_progress; 3943 sector_div(writepos, new_data_disks); 3944 readpos = conf->reshape_progress; 3945 sector_div(readpos, data_disks); 3946 safepos = conf->reshape_safe; 3947 sector_div(safepos, data_disks); 3948 if (mddev->delta_disks < 0) { 3949 writepos -= min_t(sector_t, reshape_sectors, writepos); 3950 readpos += reshape_sectors; 3951 safepos += reshape_sectors; 3952 } else { 3953 writepos += reshape_sectors; 3954 readpos -= min_t(sector_t, reshape_sectors, readpos); 3955 safepos -= min_t(sector_t, reshape_sectors, safepos); 3956 } 3957 3958 /* 'writepos' is the most advanced device address we might write. 3959 * 'readpos' is the least advanced device address we might read. 3960 * 'safepos' is the least address recorded in the metadata as having 3961 * been reshaped. 3962 * If 'readpos' is behind 'writepos', then there is no way that we can 3963 * ensure safety in the face of a crash - that must be done by userspace 3964 * making a backup of the data. So in that case there is no particular 3965 * rush to update metadata. 3966 * Otherwise if 'safepos' is behind 'writepos', then we really need to 3967 * update the metadata to advance 'safepos' to match 'readpos' so that 3968 * we can be safe in the event of a crash. 3969 * So we insist on updating metadata if safepos is behind writepos and 3970 * readpos is beyond writepos. 3971 * In any case, update the metadata every 10 seconds. 3972 * Maybe that number should be configurable, but I'm not sure it is 3973 * worth it.... maybe it could be a multiple of safemode_delay??? 3974 */ 3975 if ((mddev->delta_disks < 0 3976 ? (safepos > writepos && readpos < writepos) 3977 : (safepos < writepos && readpos > writepos)) || 3978 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { 3979 /* Cannot proceed until we've updated the superblock... */ 3980 wait_event(conf->wait_for_overlap, 3981 atomic_read(&conf->reshape_stripes)==0); 3982 mddev->reshape_position = conf->reshape_progress; 3983 mddev->curr_resync_completed = sector_nr; 3984 conf->reshape_checkpoint = jiffies; 3985 set_bit(MD_CHANGE_DEVS, &mddev->flags); 3986 md_wakeup_thread(mddev->thread); 3987 wait_event(mddev->sb_wait, mddev->flags == 0 || 3988 kthread_should_stop()); 3989 spin_lock_irq(&conf->device_lock); 3990 conf->reshape_safe = mddev->reshape_position; 3991 spin_unlock_irq(&conf->device_lock); 3992 wake_up(&conf->wait_for_overlap); 3993 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3994 } 3995 3996 if (mddev->delta_disks < 0) { 3997 BUG_ON(conf->reshape_progress == 0); 3998 stripe_addr = writepos; 3999 BUG_ON((mddev->dev_sectors & 4000 ~((sector_t)reshape_sectors - 1)) 4001 - reshape_sectors - stripe_addr 4002 != sector_nr); 4003 } else { 4004 BUG_ON(writepos != sector_nr + reshape_sectors); 4005 stripe_addr = sector_nr; 4006 } 4007 INIT_LIST_HEAD(&stripes); 4008 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { 4009 int j; 4010 int skipped_disk = 0; 4011 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1); 4012 set_bit(STRIPE_EXPANDING, &sh->state); 4013 atomic_inc(&conf->reshape_stripes); 4014 /* If any of this stripe is beyond the end of the old 4015 * array, then we need to zero those blocks 4016 */ 4017 for (j=sh->disks; j--;) { 4018 sector_t s; 4019 if (j == sh->pd_idx) 4020 continue; 4021 if (conf->level == 6 && 4022 j == sh->qd_idx) 4023 continue; 4024 s = compute_blocknr(sh, j, 0); 4025 if (s < raid5_size(mddev, 0, 0)) { 4026 skipped_disk = 1; 4027 continue; 4028 } 4029 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); 4030 set_bit(R5_Expanded, &sh->dev[j].flags); 4031 set_bit(R5_UPTODATE, &sh->dev[j].flags); 4032 } 4033 if (!skipped_disk) { 4034 set_bit(STRIPE_EXPAND_READY, &sh->state); 4035 set_bit(STRIPE_HANDLE, &sh->state); 4036 } 4037 list_add(&sh->lru, &stripes); 4038 } 4039 spin_lock_irq(&conf->device_lock); 4040 if (mddev->delta_disks < 0) 4041 conf->reshape_progress -= reshape_sectors * new_data_disks; 4042 else 4043 conf->reshape_progress += reshape_sectors * new_data_disks; 4044 spin_unlock_irq(&conf->device_lock); 4045 /* Ok, those stripe are ready. We can start scheduling 4046 * reads on the source stripes. 4047 * The source stripes are determined by mapping the first and last 4048 * block on the destination stripes. 4049 */ 4050 first_sector = 4051 raid5_compute_sector(conf, stripe_addr*(new_data_disks), 4052 1, &dd_idx, NULL); 4053 last_sector = 4054 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) 4055 * new_data_disks - 1), 4056 1, &dd_idx, NULL); 4057 if (last_sector >= mddev->dev_sectors) 4058 last_sector = mddev->dev_sectors - 1; 4059 while (first_sector <= last_sector) { 4060 sh = get_active_stripe(conf, first_sector, 1, 0, 1); 4061 set_bit(STRIPE_EXPAND_SOURCE, &sh->state); 4062 set_bit(STRIPE_HANDLE, &sh->state); 4063 release_stripe(sh); 4064 first_sector += STRIPE_SECTORS; 4065 } 4066 /* Now that the sources are clearly marked, we can release 4067 * the destination stripes 4068 */ 4069 while (!list_empty(&stripes)) { 4070 sh = list_entry(stripes.next, struct stripe_head, lru); 4071 list_del_init(&sh->lru); 4072 release_stripe(sh); 4073 } 4074 /* If this takes us to the resync_max point where we have to pause, 4075 * then we need to write out the superblock. 4076 */ 4077 sector_nr += reshape_sectors; 4078 if ((sector_nr - mddev->curr_resync_completed) * 2 4079 >= mddev->resync_max - mddev->curr_resync_completed) { 4080 /* Cannot proceed until we've updated the superblock... */ 4081 wait_event(conf->wait_for_overlap, 4082 atomic_read(&conf->reshape_stripes) == 0); 4083 mddev->reshape_position = conf->reshape_progress; 4084 mddev->curr_resync_completed = sector_nr; 4085 conf->reshape_checkpoint = jiffies; 4086 set_bit(MD_CHANGE_DEVS, &mddev->flags); 4087 md_wakeup_thread(mddev->thread); 4088 wait_event(mddev->sb_wait, 4089 !test_bit(MD_CHANGE_DEVS, &mddev->flags) 4090 || kthread_should_stop()); 4091 spin_lock_irq(&conf->device_lock); 4092 conf->reshape_safe = mddev->reshape_position; 4093 spin_unlock_irq(&conf->device_lock); 4094 wake_up(&conf->wait_for_overlap); 4095 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 4096 } 4097 return reshape_sectors; 4098} 4099 4100/* FIXME go_faster isn't used */ 4101static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster) 4102{ 4103 struct r5conf *conf = mddev->private; 4104 struct stripe_head *sh; 4105 sector_t max_sector = mddev->dev_sectors; 4106 sector_t sync_blocks; 4107 int still_degraded = 0; 4108 int i; 4109 4110 if (sector_nr >= max_sector) { 4111 /* just being told to finish up .. nothing much to do */ 4112 4113 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { 4114 end_reshape(conf); 4115 return 0; 4116 } 4117 4118 if (mddev->curr_resync < max_sector) /* aborted */ 4119 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 4120 &sync_blocks, 1); 4121 else /* completed sync */ 4122 conf->fullsync = 0; 4123 bitmap_close_sync(mddev->bitmap); 4124 4125 return 0; 4126 } 4127 4128 /* Allow raid5_quiesce to complete */ 4129 wait_event(conf->wait_for_overlap, conf->quiesce != 2); 4130 4131 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) 4132 return reshape_request(mddev, sector_nr, skipped); 4133 4134 /* No need to check resync_max as we never do more than one 4135 * stripe, and as resync_max will always be on a chunk boundary, 4136 * if the check in md_do_sync didn't fire, there is no chance 4137 * of overstepping resync_max here 4138 */ 4139 4140 /* if there is too many failed drives and we are trying 4141 * to resync, then assert that we are finished, because there is 4142 * nothing we can do. 4143 */ 4144 if (mddev->degraded >= conf->max_degraded && 4145 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 4146 sector_t rv = mddev->dev_sectors - sector_nr; 4147 *skipped = 1; 4148 return rv; 4149 } 4150 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 4151 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 4152 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { 4153 /* we can skip this block, and probably more */ 4154 sync_blocks /= STRIPE_SECTORS; 4155 *skipped = 1; 4156 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ 4157 } 4158 4159 4160 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 4161 4162 sh = get_active_stripe(conf, sector_nr, 0, 1, 0); 4163 if (sh == NULL) { 4164 sh = get_active_stripe(conf, sector_nr, 0, 0, 0); 4165 /* make sure we don't swamp the stripe cache if someone else 4166 * is trying to get access 4167 */ 4168 schedule_timeout_uninterruptible(1); 4169 } 4170 /* Need to check if array will still be degraded after recovery/resync 4171 * We don't need to check the 'failed' flag as when that gets set, 4172 * recovery aborts. 4173 */ 4174 for (i = 0; i < conf->raid_disks; i++) 4175 if (conf->disks[i].rdev == NULL) 4176 still_degraded = 1; 4177 4178 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); 4179 4180 set_bit(STRIPE_SYNC_REQUESTED, &sh->state); 4181 4182 handle_stripe(sh); 4183 release_stripe(sh); 4184 4185 return STRIPE_SECTORS; 4186} 4187 4188static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) 4189{ 4190 /* We may not be able to submit a whole bio at once as there 4191 * may not be enough stripe_heads available. 4192 * We cannot pre-allocate enough stripe_heads as we may need 4193 * more than exist in the cache (if we allow ever large chunks). 4194 * So we do one stripe head at a time and record in 4195 * ->bi_hw_segments how many have been done. 4196 * 4197 * We *know* that this entire raid_bio is in one chunk, so 4198 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. 4199 */ 4200 struct stripe_head *sh; 4201 int dd_idx; 4202 sector_t sector, logical_sector, last_sector; 4203 int scnt = 0; 4204 int remaining; 4205 int handled = 0; 4206 4207 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 4208 sector = raid5_compute_sector(conf, logical_sector, 4209 0, &dd_idx, NULL); 4210 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); 4211 4212 for (; logical_sector < last_sector; 4213 logical_sector += STRIPE_SECTORS, 4214 sector += STRIPE_SECTORS, 4215 scnt++) { 4216 4217 if (scnt < raid5_bi_hw_segments(raid_bio)) 4218 /* already done this stripe */ 4219 continue; 4220 4221 sh = get_active_stripe(conf, sector, 0, 1, 0); 4222 4223 if (!sh) { 4224 /* failed to get a stripe - must wait */ 4225 raid5_set_bi_hw_segments(raid_bio, scnt); 4226 conf->retry_read_aligned = raid_bio; 4227 return handled; 4228 } 4229 4230 set_bit(R5_ReadError, &sh->dev[dd_idx].flags); 4231 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { 4232 release_stripe(sh); 4233 raid5_set_bi_hw_segments(raid_bio, scnt); 4234 conf->retry_read_aligned = raid_bio; 4235 return handled; 4236 } 4237 4238 handle_stripe(sh); 4239 release_stripe(sh); 4240 handled++; 4241 } 4242 spin_lock_irq(&conf->device_lock); 4243 remaining = raid5_dec_bi_phys_segments(raid_bio); 4244 spin_unlock_irq(&conf->device_lock); 4245 if (remaining == 0) 4246 bio_endio(raid_bio, 0); 4247 if (atomic_dec_and_test(&conf->active_aligned_reads)) 4248 wake_up(&conf->wait_for_stripe); 4249 return handled; 4250} 4251 4252 4253/* 4254 * This is our raid5 kernel thread. 4255 * 4256 * We scan the hash table for stripes which can be handled now. 4257 * During the scan, completed stripes are saved for us by the interrupt 4258 * handler, so that they will not have to wait for our next wakeup. 4259 */ 4260static void raid5d(struct mddev *mddev) 4261{ 4262 struct stripe_head *sh; 4263 struct r5conf *conf = mddev->private; 4264 int handled; 4265 struct blk_plug plug; 4266 4267 pr_debug("+++ raid5d active\n"); 4268 4269 md_check_recovery(mddev); 4270 4271 blk_start_plug(&plug); 4272 handled = 0; 4273 spin_lock_irq(&conf->device_lock); 4274 while (1) { 4275 struct bio *bio; 4276 4277 if (atomic_read(&mddev->plug_cnt) == 0 && 4278 !list_empty(&conf->bitmap_list)) { 4279 /* Now is a good time to flush some bitmap updates */ 4280 conf->seq_flush++; 4281 spin_unlock_irq(&conf->device_lock); 4282 bitmap_unplug(mddev->bitmap); 4283 spin_lock_irq(&conf->device_lock); 4284 conf->seq_write = conf->seq_flush; 4285 activate_bit_delay(conf); 4286 } 4287 if (atomic_read(&mddev->plug_cnt) == 0) 4288 raid5_activate_delayed(conf); 4289 4290 while ((bio = remove_bio_from_retry(conf))) { 4291 int ok; 4292 spin_unlock_irq(&conf->device_lock); 4293 ok = retry_aligned_read(conf, bio); 4294 spin_lock_irq(&conf->device_lock); 4295 if (!ok) 4296 break; 4297 handled++; 4298 } 4299 4300 sh = __get_priority_stripe(conf); 4301 4302 if (!sh) 4303 break; 4304 spin_unlock_irq(&conf->device_lock); 4305 4306 handled++; 4307 handle_stripe(sh); 4308 release_stripe(sh); 4309 cond_resched(); 4310 4311 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) 4312 md_check_recovery(mddev); 4313 4314 spin_lock_irq(&conf->device_lock); 4315 } 4316 pr_debug("%d stripes handled\n", handled); 4317 4318 spin_unlock_irq(&conf->device_lock); 4319 4320 async_tx_issue_pending_all(); 4321 blk_finish_plug(&plug); 4322 4323 pr_debug("--- raid5d inactive\n"); 4324} 4325 4326static ssize_t 4327raid5_show_stripe_cache_size(struct mddev *mddev, char *page) 4328{ 4329 struct r5conf *conf = mddev->private; 4330 if (conf) 4331 return sprintf(page, "%d\n", conf->max_nr_stripes); 4332 else 4333 return 0; 4334} 4335 4336int 4337raid5_set_cache_size(struct mddev *mddev, int size) 4338{ 4339 struct r5conf *conf = mddev->private; 4340 int err; 4341 4342 if (size <= 16 || size > 32768) 4343 return -EINVAL; 4344 while (size < conf->max_nr_stripes) { 4345 if (drop_one_stripe(conf)) 4346 conf->max_nr_stripes--; 4347 else 4348 break; 4349 } 4350 err = md_allow_write(mddev); 4351 if (err) 4352 return err; 4353 while (size > conf->max_nr_stripes) { 4354 if (grow_one_stripe(conf)) 4355 conf->max_nr_stripes++; 4356 else break; 4357 } 4358 return 0; 4359} 4360EXPORT_SYMBOL(raid5_set_cache_size); 4361 4362static ssize_t 4363raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len) 4364{ 4365 struct r5conf *conf = mddev->private; 4366 unsigned long new; 4367 int err; 4368 4369 if (len >= PAGE_SIZE) 4370 return -EINVAL; 4371 if (!conf) 4372 return -ENODEV; 4373 4374 if (strict_strtoul(page, 10, &new)) 4375 return -EINVAL; 4376 err = raid5_set_cache_size(mddev, new); 4377 if (err) 4378 return err; 4379 return len; 4380} 4381 4382static struct md_sysfs_entry 4383raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, 4384 raid5_show_stripe_cache_size, 4385 raid5_store_stripe_cache_size); 4386 4387static ssize_t 4388raid5_show_preread_threshold(struct mddev *mddev, char *page) 4389{ 4390 struct r5conf *conf = mddev->private; 4391 if (conf) 4392 return sprintf(page, "%d\n", conf->bypass_threshold); 4393 else 4394 return 0; 4395} 4396 4397static ssize_t 4398raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len) 4399{ 4400 struct r5conf *conf = mddev->private; 4401 unsigned long new; 4402 if (len >= PAGE_SIZE) 4403 return -EINVAL; 4404 if (!conf) 4405 return -ENODEV; 4406 4407 if (strict_strtoul(page, 10, &new)) 4408 return -EINVAL; 4409 if (new > conf->max_nr_stripes) 4410 return -EINVAL; 4411 conf->bypass_threshold = new; 4412 return len; 4413} 4414 4415static struct md_sysfs_entry 4416raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, 4417 S_IRUGO | S_IWUSR, 4418 raid5_show_preread_threshold, 4419 raid5_store_preread_threshold); 4420 4421static ssize_t 4422stripe_cache_active_show(struct mddev *mddev, char *page) 4423{ 4424 struct r5conf *conf = mddev->private; 4425 if (conf) 4426 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); 4427 else 4428 return 0; 4429} 4430 4431static struct md_sysfs_entry 4432raid5_stripecache_active = __ATTR_RO(stripe_cache_active); 4433 4434static struct attribute *raid5_attrs[] = { 4435 &raid5_stripecache_size.attr, 4436 &raid5_stripecache_active.attr, 4437 &raid5_preread_bypass_threshold.attr, 4438 NULL, 4439}; 4440static struct attribute_group raid5_attrs_group = { 4441 .name = NULL, 4442 .attrs = raid5_attrs, 4443}; 4444 4445static sector_t 4446raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks) 4447{ 4448 struct r5conf *conf = mddev->private; 4449 4450 if (!sectors) 4451 sectors = mddev->dev_sectors; 4452 if (!raid_disks) 4453 /* size is defined by the smallest of previous and new size */ 4454 raid_disks = min(conf->raid_disks, conf->previous_raid_disks); 4455 4456 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 4457 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); 4458 return sectors * (raid_disks - conf->max_degraded); 4459} 4460 4461static void raid5_free_percpu(struct r5conf *conf) 4462{ 4463 struct raid5_percpu *percpu; 4464 unsigned long cpu; 4465 4466 if (!conf->percpu) 4467 return; 4468 4469 get_online_cpus(); 4470 for_each_possible_cpu(cpu) { 4471 percpu = per_cpu_ptr(conf->percpu, cpu); 4472 safe_put_page(percpu->spare_page); 4473 kfree(percpu->scribble); 4474 } 4475#ifdef CONFIG_HOTPLUG_CPU 4476 unregister_cpu_notifier(&conf->cpu_notify); 4477#endif 4478 put_online_cpus(); 4479 4480 free_percpu(conf->percpu); 4481} 4482 4483static void free_conf(struct r5conf *conf) 4484{ 4485 shrink_stripes(conf); 4486 raid5_free_percpu(conf); 4487 kfree(conf->disks); 4488 kfree(conf->stripe_hashtbl); 4489 kfree(conf); 4490} 4491 4492#ifdef CONFIG_HOTPLUG_CPU 4493static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, 4494 void *hcpu) 4495{ 4496 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify); 4497 long cpu = (long)hcpu; 4498 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); 4499 4500 switch (action) { 4501 case CPU_UP_PREPARE: 4502 case CPU_UP_PREPARE_FROZEN: 4503 if (conf->level == 6 && !percpu->spare_page) 4504 percpu->spare_page = alloc_page(GFP_KERNEL); 4505 if (!percpu->scribble) 4506 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4507 4508 if (!percpu->scribble || 4509 (conf->level == 6 && !percpu->spare_page)) { 4510 safe_put_page(percpu->spare_page); 4511 kfree(percpu->scribble); 4512 pr_err("%s: failed memory allocation for cpu%ld\n", 4513 __func__, cpu); 4514 return notifier_from_errno(-ENOMEM); 4515 } 4516 break; 4517 case CPU_DEAD: 4518 case CPU_DEAD_FROZEN: 4519 safe_put_page(percpu->spare_page); 4520 kfree(percpu->scribble); 4521 percpu->spare_page = NULL; 4522 percpu->scribble = NULL; 4523 break; 4524 default: 4525 break; 4526 } 4527 return NOTIFY_OK; 4528} 4529#endif 4530 4531static int raid5_alloc_percpu(struct r5conf *conf) 4532{ 4533 unsigned long cpu; 4534 struct page *spare_page; 4535 struct raid5_percpu __percpu *allcpus; 4536 void *scribble; 4537 int err; 4538 4539 allcpus = alloc_percpu(struct raid5_percpu); 4540 if (!allcpus) 4541 return -ENOMEM; 4542 conf->percpu = allcpus; 4543 4544 get_online_cpus(); 4545 err = 0; 4546 for_each_present_cpu(cpu) { 4547 if (conf->level == 6) { 4548 spare_page = alloc_page(GFP_KERNEL); 4549 if (!spare_page) { 4550 err = -ENOMEM; 4551 break; 4552 } 4553 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page; 4554 } 4555 scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4556 if (!scribble) { 4557 err = -ENOMEM; 4558 break; 4559 } 4560 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; 4561 } 4562#ifdef CONFIG_HOTPLUG_CPU 4563 conf->cpu_notify.notifier_call = raid456_cpu_notify; 4564 conf->cpu_notify.priority = 0; 4565 if (err == 0) 4566 err = register_cpu_notifier(&conf->cpu_notify); 4567#endif 4568 put_online_cpus(); 4569 4570 return err; 4571} 4572 4573static struct r5conf *setup_conf(struct mddev *mddev) 4574{ 4575 struct r5conf *conf; 4576 int raid_disk, memory, max_disks; 4577 struct md_rdev *rdev; 4578 struct disk_info *disk; 4579 4580 if (mddev->new_level != 5 4581 && mddev->new_level != 4 4582 && mddev->new_level != 6) { 4583 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n", 4584 mdname(mddev), mddev->new_level); 4585 return ERR_PTR(-EIO); 4586 } 4587 if ((mddev->new_level == 5 4588 && !algorithm_valid_raid5(mddev->new_layout)) || 4589 (mddev->new_level == 6 4590 && !algorithm_valid_raid6(mddev->new_layout))) { 4591 printk(KERN_ERR "md/raid:%s: layout %d not supported\n", 4592 mdname(mddev), mddev->new_layout); 4593 return ERR_PTR(-EIO); 4594 } 4595 if (mddev->new_level == 6 && mddev->raid_disks < 4) { 4596 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n", 4597 mdname(mddev), mddev->raid_disks); 4598 return ERR_PTR(-EINVAL); 4599 } 4600 4601 if (!mddev->new_chunk_sectors || 4602 (mddev->new_chunk_sectors << 9) % PAGE_SIZE || 4603 !is_power_of_2(mddev->new_chunk_sectors)) { 4604 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n", 4605 mdname(mddev), mddev->new_chunk_sectors << 9); 4606 return ERR_PTR(-EINVAL); 4607 } 4608 4609 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL); 4610 if (conf == NULL) 4611 goto abort; 4612 spin_lock_init(&conf->device_lock); 4613 init_waitqueue_head(&conf->wait_for_stripe); 4614 init_waitqueue_head(&conf->wait_for_overlap); 4615 INIT_LIST_HEAD(&conf->handle_list); 4616 INIT_LIST_HEAD(&conf->hold_list); 4617 INIT_LIST_HEAD(&conf->delayed_list); 4618 INIT_LIST_HEAD(&conf->bitmap_list); 4619 INIT_LIST_HEAD(&conf->inactive_list); 4620 atomic_set(&conf->active_stripes, 0); 4621 atomic_set(&conf->preread_active_stripes, 0); 4622 atomic_set(&conf->active_aligned_reads, 0); 4623 conf->bypass_threshold = BYPASS_THRESHOLD; 4624 conf->recovery_disabled = mddev->recovery_disabled - 1; 4625 4626 conf->raid_disks = mddev->raid_disks; 4627 if (mddev->reshape_position == MaxSector) 4628 conf->previous_raid_disks = mddev->raid_disks; 4629 else 4630 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; 4631 max_disks = max(conf->raid_disks, conf->previous_raid_disks); 4632 conf->scribble_len = scribble_len(max_disks); 4633 4634 conf->disks = kzalloc(max_disks * sizeof(struct disk_info), 4635 GFP_KERNEL); 4636 if (!conf->disks) 4637 goto abort; 4638 4639 conf->mddev = mddev; 4640 4641 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 4642 goto abort; 4643 4644 conf->level = mddev->new_level; 4645 if (raid5_alloc_percpu(conf) != 0) 4646 goto abort; 4647 4648 pr_debug("raid456: run(%s) called.\n", mdname(mddev)); 4649 4650 list_for_each_entry(rdev, &mddev->disks, same_set) { 4651 raid_disk = rdev->raid_disk; 4652 if (raid_disk >= max_disks 4653 || raid_disk < 0) 4654 continue; 4655 disk = conf->disks + raid_disk; 4656 4657 disk->rdev = rdev; 4658 4659 if (test_bit(In_sync, &rdev->flags)) { 4660 char b[BDEVNAME_SIZE]; 4661 printk(KERN_INFO "md/raid:%s: device %s operational as raid" 4662 " disk %d\n", 4663 mdname(mddev), bdevname(rdev->bdev, b), raid_disk); 4664 } else if (rdev->saved_raid_disk != raid_disk) 4665 /* Cannot rely on bitmap to complete recovery */ 4666 conf->fullsync = 1; 4667 } 4668 4669 conf->chunk_sectors = mddev->new_chunk_sectors; 4670 conf->level = mddev->new_level; 4671 if (conf->level == 6) 4672 conf->max_degraded = 2; 4673 else 4674 conf->max_degraded = 1; 4675 conf->algorithm = mddev->new_layout; 4676 conf->max_nr_stripes = NR_STRIPES; 4677 conf->reshape_progress = mddev->reshape_position; 4678 if (conf->reshape_progress != MaxSector) { 4679 conf->prev_chunk_sectors = mddev->chunk_sectors; 4680 conf->prev_algo = mddev->layout; 4681 } 4682 4683 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 4684 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; 4685 if (grow_stripes(conf, conf->max_nr_stripes)) { 4686 printk(KERN_ERR 4687 "md/raid:%s: couldn't allocate %dkB for buffers\n", 4688 mdname(mddev), memory); 4689 goto abort; 4690 } else 4691 printk(KERN_INFO "md/raid:%s: allocated %dkB\n", 4692 mdname(mddev), memory); 4693 4694 conf->thread = md_register_thread(raid5d, mddev, NULL); 4695 if (!conf->thread) { 4696 printk(KERN_ERR 4697 "md/raid:%s: couldn't allocate thread.\n", 4698 mdname(mddev)); 4699 goto abort; 4700 } 4701 4702 return conf; 4703 4704 abort: 4705 if (conf) { 4706 free_conf(conf); 4707 return ERR_PTR(-EIO); 4708 } else 4709 return ERR_PTR(-ENOMEM); 4710} 4711 4712 4713static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) 4714{ 4715 switch (algo) { 4716 case ALGORITHM_PARITY_0: 4717 if (raid_disk < max_degraded) 4718 return 1; 4719 break; 4720 case ALGORITHM_PARITY_N: 4721 if (raid_disk >= raid_disks - max_degraded) 4722 return 1; 4723 break; 4724 case ALGORITHM_PARITY_0_6: 4725 if (raid_disk == 0 || 4726 raid_disk == raid_disks - 1) 4727 return 1; 4728 break; 4729 case ALGORITHM_LEFT_ASYMMETRIC_6: 4730 case ALGORITHM_RIGHT_ASYMMETRIC_6: 4731 case ALGORITHM_LEFT_SYMMETRIC_6: 4732 case ALGORITHM_RIGHT_SYMMETRIC_6: 4733 if (raid_disk == raid_disks - 1) 4734 return 1; 4735 } 4736 return 0; 4737} 4738 4739static int run(struct mddev *mddev) 4740{ 4741 struct r5conf *conf; 4742 int working_disks = 0; 4743 int dirty_parity_disks = 0; 4744 struct md_rdev *rdev; 4745 sector_t reshape_offset = 0; 4746 4747 if (mddev->recovery_cp != MaxSector) 4748 printk(KERN_NOTICE "md/raid:%s: not clean" 4749 " -- starting background reconstruction\n", 4750 mdname(mddev)); 4751 if (mddev->reshape_position != MaxSector) { 4752 /* Check that we can continue the reshape. 4753 * Currently only disks can change, it must 4754 * increase, and we must be past the point where 4755 * a stripe over-writes itself 4756 */ 4757 sector_t here_new, here_old; 4758 int old_disks; 4759 int max_degraded = (mddev->level == 6 ? 2 : 1); 4760 4761 if (mddev->new_level != mddev->level) { 4762 printk(KERN_ERR "md/raid:%s: unsupported reshape " 4763 "required - aborting.\n", 4764 mdname(mddev)); 4765 return -EINVAL; 4766 } 4767 old_disks = mddev->raid_disks - mddev->delta_disks; 4768 /* reshape_position must be on a new-stripe boundary, and one 4769 * further up in new geometry must map after here in old 4770 * geometry. 4771 */ 4772 here_new = mddev->reshape_position; 4773 if (sector_div(here_new, mddev->new_chunk_sectors * 4774 (mddev->raid_disks - max_degraded))) { 4775 printk(KERN_ERR "md/raid:%s: reshape_position not " 4776 "on a stripe boundary\n", mdname(mddev)); 4777 return -EINVAL; 4778 } 4779 reshape_offset = here_new * mddev->new_chunk_sectors; 4780 /* here_new is the stripe we will write to */ 4781 here_old = mddev->reshape_position; 4782 sector_div(here_old, mddev->chunk_sectors * 4783 (old_disks-max_degraded)); 4784 /* here_old is the first stripe that we might need to read 4785 * from */ 4786 if (mddev->delta_disks == 0) { 4787 /* We cannot be sure it is safe to start an in-place 4788 * reshape. It is only safe if user-space if monitoring 4789 * and taking constant backups. 4790 * mdadm always starts a situation like this in 4791 * readonly mode so it can take control before 4792 * allowing any writes. So just check for that. 4793 */ 4794 if ((here_new * mddev->new_chunk_sectors != 4795 here_old * mddev->chunk_sectors) || 4796 mddev->ro == 0) { 4797 printk(KERN_ERR "md/raid:%s: in-place reshape must be started" 4798 " in read-only mode - aborting\n", 4799 mdname(mddev)); 4800 return -EINVAL; 4801 } 4802 } else if (mddev->delta_disks < 0 4803 ? (here_new * mddev->new_chunk_sectors <= 4804 here_old * mddev->chunk_sectors) 4805 : (here_new * mddev->new_chunk_sectors >= 4806 here_old * mddev->chunk_sectors)) { 4807 /* Reading from the same stripe as writing to - bad */ 4808 printk(KERN_ERR "md/raid:%s: reshape_position too early for " 4809 "auto-recovery - aborting.\n", 4810 mdname(mddev)); 4811 return -EINVAL; 4812 } 4813 printk(KERN_INFO "md/raid:%s: reshape will continue\n", 4814 mdname(mddev)); 4815 /* OK, we should be able to continue; */ 4816 } else { 4817 BUG_ON(mddev->level != mddev->new_level); 4818 BUG_ON(mddev->layout != mddev->new_layout); 4819 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); 4820 BUG_ON(mddev->delta_disks != 0); 4821 } 4822 4823 if (mddev->private == NULL) 4824 conf = setup_conf(mddev); 4825 else 4826 conf = mddev->private; 4827 4828 if (IS_ERR(conf)) 4829 return PTR_ERR(conf); 4830 4831 mddev->thread = conf->thread; 4832 conf->thread = NULL; 4833 mddev->private = conf; 4834 4835 /* 4836 * 0 for a fully functional array, 1 or 2 for a degraded array. 4837 */ 4838 list_for_each_entry(rdev, &mddev->disks, same_set) { 4839 if (rdev->raid_disk < 0) 4840 continue; 4841 if (test_bit(In_sync, &rdev->flags)) { 4842 working_disks++; 4843 continue; 4844 } 4845 /* This disc is not fully in-sync. However if it 4846 * just stored parity (beyond the recovery_offset), 4847 * when we don't need to be concerned about the 4848 * array being dirty. 4849 * When reshape goes 'backwards', we never have 4850 * partially completed devices, so we only need 4851 * to worry about reshape going forwards. 4852 */ 4853 /* Hack because v0.91 doesn't store recovery_offset properly. */ 4854 if (mddev->major_version == 0 && 4855 mddev->minor_version > 90) 4856 rdev->recovery_offset = reshape_offset; 4857 4858 if (rdev->recovery_offset < reshape_offset) { 4859 /* We need to check old and new layout */ 4860 if (!only_parity(rdev->raid_disk, 4861 conf->algorithm, 4862 conf->raid_disks, 4863 conf->max_degraded)) 4864 continue; 4865 } 4866 if (!only_parity(rdev->raid_disk, 4867 conf->prev_algo, 4868 conf->previous_raid_disks, 4869 conf->max_degraded)) 4870 continue; 4871 dirty_parity_disks++; 4872 } 4873 4874 mddev->degraded = calc_degraded(conf); 4875 4876 if (has_failed(conf)) { 4877 printk(KERN_ERR "md/raid:%s: not enough operational devices" 4878 " (%d/%d failed)\n", 4879 mdname(mddev), mddev->degraded, conf->raid_disks); 4880 goto abort; 4881 } 4882 4883 /* device size must be a multiple of chunk size */ 4884 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); 4885 mddev->resync_max_sectors = mddev->dev_sectors; 4886 4887 if (mddev->degraded > dirty_parity_disks && 4888 mddev->recovery_cp != MaxSector) { 4889 if (mddev->ok_start_degraded) 4890 printk(KERN_WARNING 4891 "md/raid:%s: starting dirty degraded array" 4892 " - data corruption possible.\n", 4893 mdname(mddev)); 4894 else { 4895 printk(KERN_ERR 4896 "md/raid:%s: cannot start dirty degraded array.\n", 4897 mdname(mddev)); 4898 goto abort; 4899 } 4900 } 4901 4902 if (mddev->degraded == 0) 4903 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d" 4904 " devices, algorithm %d\n", mdname(mddev), conf->level, 4905 mddev->raid_disks-mddev->degraded, mddev->raid_disks, 4906 mddev->new_layout); 4907 else 4908 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d" 4909 " out of %d devices, algorithm %d\n", 4910 mdname(mddev), conf->level, 4911 mddev->raid_disks - mddev->degraded, 4912 mddev->raid_disks, mddev->new_layout); 4913 4914 print_raid5_conf(conf); 4915 4916 if (conf->reshape_progress != MaxSector) { 4917 conf->reshape_safe = conf->reshape_progress; 4918 atomic_set(&conf->reshape_stripes, 0); 4919 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 4920 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 4921 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 4922 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 4923 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 4924 "reshape"); 4925 } 4926 4927 4928 /* Ok, everything is just fine now */ 4929 if (mddev->to_remove == &raid5_attrs_group) 4930 mddev->to_remove = NULL; 4931 else if (mddev->kobj.sd && 4932 sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) 4933 printk(KERN_WARNING 4934 "raid5: failed to create sysfs attributes for %s\n", 4935 mdname(mddev)); 4936 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 4937 4938 if (mddev->queue) { 4939 int chunk_size; 4940 /* read-ahead size must cover two whole stripes, which 4941 * is 2 * (datadisks) * chunksize where 'n' is the 4942 * number of raid devices 4943 */ 4944 int data_disks = conf->previous_raid_disks - conf->max_degraded; 4945 int stripe = data_disks * 4946 ((mddev->chunk_sectors << 9) / PAGE_SIZE); 4947 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 4948 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 4949 4950 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); 4951 4952 mddev->queue->backing_dev_info.congested_data = mddev; 4953 mddev->queue->backing_dev_info.congested_fn = raid5_congested; 4954 4955 chunk_size = mddev->chunk_sectors << 9; 4956 blk_queue_io_min(mddev->queue, chunk_size); 4957 blk_queue_io_opt(mddev->queue, chunk_size * 4958 (conf->raid_disks - conf->max_degraded)); 4959 4960 list_for_each_entry(rdev, &mddev->disks, same_set) 4961 disk_stack_limits(mddev->gendisk, rdev->bdev, 4962 rdev->data_offset << 9); 4963 } 4964 4965 return 0; 4966abort: 4967 md_unregister_thread(&mddev->thread); 4968 print_raid5_conf(conf); 4969 free_conf(conf); 4970 mddev->private = NULL; 4971 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev)); 4972 return -EIO; 4973} 4974 4975static int stop(struct mddev *mddev) 4976{ 4977 struct r5conf *conf = mddev->private; 4978 4979 md_unregister_thread(&mddev->thread); 4980 if (mddev->queue) 4981 mddev->queue->backing_dev_info.congested_fn = NULL; 4982 free_conf(conf); 4983 mddev->private = NULL; 4984 mddev->to_remove = &raid5_attrs_group; 4985 return 0; 4986} 4987 4988static void status(struct seq_file *seq, struct mddev *mddev) 4989{ 4990 struct r5conf *conf = mddev->private; 4991 int i; 4992 4993 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, 4994 mddev->chunk_sectors / 2, mddev->layout); 4995 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); 4996 for (i = 0; i < conf->raid_disks; i++) 4997 seq_printf (seq, "%s", 4998 conf->disks[i].rdev && 4999 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 5000 seq_printf (seq, "]"); 5001} 5002 5003static void print_raid5_conf (struct r5conf *conf) 5004{ 5005 int i; 5006 struct disk_info *tmp; 5007 5008 printk(KERN_DEBUG "RAID conf printout:\n"); 5009 if (!conf) { 5010 printk("(conf==NULL)\n"); 5011 return; 5012 } 5013 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level, 5014 conf->raid_disks, 5015 conf->raid_disks - conf->mddev->degraded); 5016 5017 for (i = 0; i < conf->raid_disks; i++) { 5018 char b[BDEVNAME_SIZE]; 5019 tmp = conf->disks + i; 5020 if (tmp->rdev) 5021 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n", 5022 i, !test_bit(Faulty, &tmp->rdev->flags), 5023 bdevname(tmp->rdev->bdev, b)); 5024 } 5025} 5026 5027static int raid5_spare_active(struct mddev *mddev) 5028{ 5029 int i; 5030 struct r5conf *conf = mddev->private; 5031 struct disk_info *tmp; 5032 int count = 0; 5033 unsigned long flags; 5034 5035 for (i = 0; i < conf->raid_disks; i++) { 5036 tmp = conf->disks + i; 5037 if (tmp->rdev 5038 && tmp->rdev->recovery_offset == MaxSector 5039 && !test_bit(Faulty, &tmp->rdev->flags) 5040 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { 5041 count++; 5042 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); 5043 } 5044 } 5045 spin_lock_irqsave(&conf->device_lock, flags); 5046 mddev->degraded = calc_degraded(conf); 5047 spin_unlock_irqrestore(&conf->device_lock, flags); 5048 print_raid5_conf(conf); 5049 return count; 5050} 5051 5052static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) 5053{ 5054 struct r5conf *conf = mddev->private; 5055 int err = 0; 5056 int number = rdev->raid_disk; 5057 struct disk_info *p = conf->disks + number; 5058 5059 print_raid5_conf(conf); 5060 if (rdev == p->rdev) { 5061 if (number >= conf->raid_disks && 5062 conf->reshape_progress == MaxSector) 5063 clear_bit(In_sync, &rdev->flags); 5064 5065 if (test_bit(In_sync, &rdev->flags) || 5066 atomic_read(&rdev->nr_pending)) { 5067 err = -EBUSY; 5068 goto abort; 5069 } 5070 /* Only remove non-faulty devices if recovery 5071 * isn't possible. 5072 */ 5073 if (!test_bit(Faulty, &rdev->flags) && 5074 mddev->recovery_disabled != conf->recovery_disabled && 5075 !has_failed(conf) && 5076 number < conf->raid_disks) { 5077 err = -EBUSY; 5078 goto abort; 5079 } 5080 p->rdev = NULL; 5081 synchronize_rcu(); 5082 if (atomic_read(&rdev->nr_pending)) { 5083 /* lost the race, try later */ 5084 err = -EBUSY; 5085 p->rdev = rdev; 5086 } 5087 } 5088abort: 5089 5090 print_raid5_conf(conf); 5091 return err; 5092} 5093 5094static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev) 5095{ 5096 struct r5conf *conf = mddev->private; 5097 int err = -EEXIST; 5098 int disk; 5099 struct disk_info *p; 5100 int first = 0; 5101 int last = conf->raid_disks - 1; 5102 5103 if (mddev->recovery_disabled == conf->recovery_disabled) 5104 return -EBUSY; 5105 5106 if (has_failed(conf)) 5107 /* no point adding a device */ 5108 return -EINVAL; 5109 5110 if (rdev->raid_disk >= 0) 5111 first = last = rdev->raid_disk; 5112 5113 /* 5114 * find the disk ... but prefer rdev->saved_raid_disk 5115 * if possible. 5116 */ 5117 if (rdev->saved_raid_disk >= 0 && 5118 rdev->saved_raid_disk >= first && 5119 conf->disks[rdev->saved_raid_disk].rdev == NULL) 5120 disk = rdev->saved_raid_disk; 5121 else 5122 disk = first; 5123 for ( ; disk <= last ; disk++) 5124 if ((p=conf->disks + disk)->rdev == NULL) { 5125 clear_bit(In_sync, &rdev->flags); 5126 rdev->raid_disk = disk; 5127 err = 0; 5128 if (rdev->saved_raid_disk != disk) 5129 conf->fullsync = 1; 5130 rcu_assign_pointer(p->rdev, rdev); 5131 break; 5132 } 5133 print_raid5_conf(conf); 5134 return err; 5135} 5136 5137static int raid5_resize(struct mddev *mddev, sector_t sectors) 5138{ 5139 /* no resync is happening, and there is enough space 5140 * on all devices, so we can resize. 5141 * We need to make sure resync covers any new space. 5142 * If the array is shrinking we should possibly wait until 5143 * any io in the removed space completes, but it hardly seems 5144 * worth it. 5145 */ 5146 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 5147 md_set_array_sectors(mddev, raid5_size(mddev, sectors, 5148 mddev->raid_disks)); 5149 if (mddev->array_sectors > 5150 raid5_size(mddev, sectors, mddev->raid_disks)) 5151 return -EINVAL; 5152 set_capacity(mddev->gendisk, mddev->array_sectors); 5153 revalidate_disk(mddev->gendisk); 5154 if (sectors > mddev->dev_sectors && 5155 mddev->recovery_cp > mddev->dev_sectors) { 5156 mddev->recovery_cp = mddev->dev_sectors; 5157 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 5158 } 5159 mddev->dev_sectors = sectors; 5160 mddev->resync_max_sectors = sectors; 5161 return 0; 5162} 5163 5164static int check_stripe_cache(struct mddev *mddev) 5165{ 5166 /* Can only proceed if there are plenty of stripe_heads. 5167 * We need a minimum of one full stripe,, and for sensible progress 5168 * it is best to have about 4 times that. 5169 * If we require 4 times, then the default 256 4K stripe_heads will 5170 * allow for chunk sizes up to 256K, which is probably OK. 5171 * If the chunk size is greater, user-space should request more 5172 * stripe_heads first. 5173 */ 5174 struct r5conf *conf = mddev->private; 5175 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 5176 > conf->max_nr_stripes || 5177 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 5178 > conf->max_nr_stripes) { 5179 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n", 5180 mdname(mddev), 5181 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) 5182 / STRIPE_SIZE)*4); 5183 return 0; 5184 } 5185 return 1; 5186} 5187 5188static int check_reshape(struct mddev *mddev) 5189{ 5190 struct r5conf *conf = mddev->private; 5191 5192 if (mddev->delta_disks == 0 && 5193 mddev->new_layout == mddev->layout && 5194 mddev->new_chunk_sectors == mddev->chunk_sectors) 5195 return 0; /* nothing to do */ 5196 if (mddev->bitmap) 5197 /* Cannot grow a bitmap yet */ 5198 return -EBUSY; 5199 if (has_failed(conf)) 5200 return -EINVAL; 5201 if (mddev->delta_disks < 0) { 5202 /* We might be able to shrink, but the devices must 5203 * be made bigger first. 5204 * For raid6, 4 is the minimum size. 5205 * Otherwise 2 is the minimum 5206 */ 5207 int min = 2; 5208 if (mddev->level == 6) 5209 min = 4; 5210 if (mddev->raid_disks + mddev->delta_disks < min) 5211 return -EINVAL; 5212 } 5213 5214 if (!check_stripe_cache(mddev)) 5215 return -ENOSPC; 5216 5217 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); 5218} 5219 5220static int raid5_start_reshape(struct mddev *mddev) 5221{ 5222 struct r5conf *conf = mddev->private; 5223 struct md_rdev *rdev; 5224 int spares = 0; 5225 unsigned long flags; 5226 5227 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 5228 return -EBUSY; 5229 5230 if (!check_stripe_cache(mddev)) 5231 return -ENOSPC; 5232 5233 list_for_each_entry(rdev, &mddev->disks, same_set) 5234 if (!test_bit(In_sync, &rdev->flags) 5235 && !test_bit(Faulty, &rdev->flags)) 5236 spares++; 5237 5238 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) 5239 /* Not enough devices even to make a degraded array 5240 * of that size 5241 */ 5242 return -EINVAL; 5243 5244 /* Refuse to reduce size of the array. Any reductions in 5245 * array size must be through explicit setting of array_size 5246 * attribute. 5247 */ 5248 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) 5249 < mddev->array_sectors) { 5250 printk(KERN_ERR "md/raid:%s: array size must be reduced " 5251 "before number of disks\n", mdname(mddev)); 5252 return -EINVAL; 5253 } 5254 5255 atomic_set(&conf->reshape_stripes, 0); 5256 spin_lock_irq(&conf->device_lock); 5257 conf->previous_raid_disks = conf->raid_disks; 5258 conf->raid_disks += mddev->delta_disks; 5259 conf->prev_chunk_sectors = conf->chunk_sectors; 5260 conf->chunk_sectors = mddev->new_chunk_sectors; 5261 conf->prev_algo = conf->algorithm; 5262 conf->algorithm = mddev->new_layout; 5263 if (mddev->delta_disks < 0) 5264 conf->reshape_progress = raid5_size(mddev, 0, 0); 5265 else 5266 conf->reshape_progress = 0; 5267 conf->reshape_safe = conf->reshape_progress; 5268 conf->generation++; 5269 spin_unlock_irq(&conf->device_lock); 5270 5271 /* Add some new drives, as many as will fit. 5272 * We know there are enough to make the newly sized array work. 5273 * Don't add devices if we are reducing the number of 5274 * devices in the array. This is because it is not possible 5275 * to correctly record the "partially reconstructed" state of 5276 * such devices during the reshape and confusion could result. 5277 */ 5278 if (mddev->delta_disks >= 0) { 5279 int added_devices = 0; 5280 list_for_each_entry(rdev, &mddev->disks, same_set) 5281 if (rdev->raid_disk < 0 && 5282 !test_bit(Faulty, &rdev->flags)) { 5283 if (raid5_add_disk(mddev, rdev) == 0) { 5284 if (rdev->raid_disk 5285 >= conf->previous_raid_disks) { 5286 set_bit(In_sync, &rdev->flags); 5287 added_devices++; 5288 } else 5289 rdev->recovery_offset = 0; 5290 5291 if (sysfs_link_rdev(mddev, rdev)) 5292 /* Failure here is OK */; 5293 } 5294 } else if (rdev->raid_disk >= conf->previous_raid_disks 5295 && !test_bit(Faulty, &rdev->flags)) { 5296 /* This is a spare that was manually added */ 5297 set_bit(In_sync, &rdev->flags); 5298 added_devices++; 5299 } 5300 5301 /* When a reshape changes the number of devices, 5302 * ->degraded is measured against the larger of the 5303 * pre and post number of devices. 5304 */ 5305 spin_lock_irqsave(&conf->device_lock, flags); 5306 mddev->degraded = calc_degraded(conf); 5307 spin_unlock_irqrestore(&conf->device_lock, flags); 5308 } 5309 mddev->raid_disks = conf->raid_disks; 5310 mddev->reshape_position = conf->reshape_progress; 5311 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5312 5313 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 5314 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 5315 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 5316 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 5317 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 5318 "reshape"); 5319 if (!mddev->sync_thread) { 5320 mddev->recovery = 0; 5321 spin_lock_irq(&conf->device_lock); 5322 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; 5323 conf->reshape_progress = MaxSector; 5324 spin_unlock_irq(&conf->device_lock); 5325 return -EAGAIN; 5326 } 5327 conf->reshape_checkpoint = jiffies; 5328 md_wakeup_thread(mddev->sync_thread); 5329 md_new_event(mddev); 5330 return 0; 5331} 5332 5333/* This is called from the reshape thread and should make any 5334 * changes needed in 'conf' 5335 */ 5336static void end_reshape(struct r5conf *conf) 5337{ 5338 5339 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { 5340 5341 spin_lock_irq(&conf->device_lock); 5342 conf->previous_raid_disks = conf->raid_disks; 5343 conf->reshape_progress = MaxSector; 5344 spin_unlock_irq(&conf->device_lock); 5345 wake_up(&conf->wait_for_overlap); 5346 5347 /* read-ahead size must cover two whole stripes, which is 5348 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 5349 */ 5350 if (conf->mddev->queue) { 5351 int data_disks = conf->raid_disks - conf->max_degraded; 5352 int stripe = data_disks * ((conf->chunk_sectors << 9) 5353 / PAGE_SIZE); 5354 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 5355 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 5356 } 5357 } 5358} 5359 5360/* This is called from the raid5d thread with mddev_lock held. 5361 * It makes config changes to the device. 5362 */ 5363static void raid5_finish_reshape(struct mddev *mddev) 5364{ 5365 struct r5conf *conf = mddev->private; 5366 5367 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { 5368 5369 if (mddev->delta_disks > 0) { 5370 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 5371 set_capacity(mddev->gendisk, mddev->array_sectors); 5372 revalidate_disk(mddev->gendisk); 5373 } else { 5374 int d; 5375 spin_lock_irq(&conf->device_lock); 5376 mddev->degraded = calc_degraded(conf); 5377 spin_unlock_irq(&conf->device_lock); 5378 for (d = conf->raid_disks ; 5379 d < conf->raid_disks - mddev->delta_disks; 5380 d++) { 5381 struct md_rdev *rdev = conf->disks[d].rdev; 5382 if (rdev && 5383 raid5_remove_disk(mddev, rdev) == 0) { 5384 sysfs_unlink_rdev(mddev, rdev); 5385 rdev->raid_disk = -1; 5386 } 5387 } 5388 } 5389 mddev->layout = conf->algorithm; 5390 mddev->chunk_sectors = conf->chunk_sectors; 5391 mddev->reshape_position = MaxSector; 5392 mddev->delta_disks = 0; 5393 } 5394} 5395 5396static void raid5_quiesce(struct mddev *mddev, int state) 5397{ 5398 struct r5conf *conf = mddev->private; 5399 5400 switch(state) { 5401 case 2: /* resume for a suspend */ 5402 wake_up(&conf->wait_for_overlap); 5403 break; 5404 5405 case 1: /* stop all writes */ 5406 spin_lock_irq(&conf->device_lock); 5407 /* '2' tells resync/reshape to pause so that all 5408 * active stripes can drain 5409 */ 5410 conf->quiesce = 2; 5411 wait_event_lock_irq(conf->wait_for_stripe, 5412 atomic_read(&conf->active_stripes) == 0 && 5413 atomic_read(&conf->active_aligned_reads) == 0, 5414 conf->device_lock, /* nothing */); 5415 conf->quiesce = 1; 5416 spin_unlock_irq(&conf->device_lock); 5417 /* allow reshape to continue */ 5418 wake_up(&conf->wait_for_overlap); 5419 break; 5420 5421 case 0: /* re-enable writes */ 5422 spin_lock_irq(&conf->device_lock); 5423 conf->quiesce = 0; 5424 wake_up(&conf->wait_for_stripe); 5425 wake_up(&conf->wait_for_overlap); 5426 spin_unlock_irq(&conf->device_lock); 5427 break; 5428 } 5429} 5430 5431 5432static void *raid45_takeover_raid0(struct mddev *mddev, int level) 5433{ 5434 struct r0conf *raid0_conf = mddev->private; 5435 sector_t sectors; 5436 5437 /* for raid0 takeover only one zone is supported */ 5438 if (raid0_conf->nr_strip_zones > 1) { 5439 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n", 5440 mdname(mddev)); 5441 return ERR_PTR(-EINVAL); 5442 } 5443 5444 sectors = raid0_conf->strip_zone[0].zone_end; 5445 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev); 5446 mddev->dev_sectors = sectors; 5447 mddev->new_level = level; 5448 mddev->new_layout = ALGORITHM_PARITY_N; 5449 mddev->new_chunk_sectors = mddev->chunk_sectors; 5450 mddev->raid_disks += 1; 5451 mddev->delta_disks = 1; 5452 /* make sure it will be not marked as dirty */ 5453 mddev->recovery_cp = MaxSector; 5454 5455 return setup_conf(mddev); 5456} 5457 5458 5459static void *raid5_takeover_raid1(struct mddev *mddev) 5460{ 5461 int chunksect; 5462 5463 if (mddev->raid_disks != 2 || 5464 mddev->degraded > 1) 5465 return ERR_PTR(-EINVAL); 5466 5467 /* Should check if there are write-behind devices? */ 5468 5469 chunksect = 64*2; /* 64K by default */ 5470 5471 /* The array must be an exact multiple of chunksize */ 5472 while (chunksect && (mddev->array_sectors & (chunksect-1))) 5473 chunksect >>= 1; 5474 5475 if ((chunksect<<9) < STRIPE_SIZE) 5476 /* array size does not allow a suitable chunk size */ 5477 return ERR_PTR(-EINVAL); 5478 5479 mddev->new_level = 5; 5480 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; 5481 mddev->new_chunk_sectors = chunksect; 5482 5483 return setup_conf(mddev); 5484} 5485 5486static void *raid5_takeover_raid6(struct mddev *mddev) 5487{ 5488 int new_layout; 5489 5490 switch (mddev->layout) { 5491 case ALGORITHM_LEFT_ASYMMETRIC_6: 5492 new_layout = ALGORITHM_LEFT_ASYMMETRIC; 5493 break; 5494 case ALGORITHM_RIGHT_ASYMMETRIC_6: 5495 new_layout = ALGORITHM_RIGHT_ASYMMETRIC; 5496 break; 5497 case ALGORITHM_LEFT_SYMMETRIC_6: 5498 new_layout = ALGORITHM_LEFT_SYMMETRIC; 5499 break; 5500 case ALGORITHM_RIGHT_SYMMETRIC_6: 5501 new_layout = ALGORITHM_RIGHT_SYMMETRIC; 5502 break; 5503 case ALGORITHM_PARITY_0_6: 5504 new_layout = ALGORITHM_PARITY_0; 5505 break; 5506 case ALGORITHM_PARITY_N: 5507 new_layout = ALGORITHM_PARITY_N; 5508 break; 5509 default: 5510 return ERR_PTR(-EINVAL); 5511 } 5512 mddev->new_level = 5; 5513 mddev->new_layout = new_layout; 5514 mddev->delta_disks = -1; 5515 mddev->raid_disks -= 1; 5516 return setup_conf(mddev); 5517} 5518 5519 5520static int raid5_check_reshape(struct mddev *mddev) 5521{ 5522 /* For a 2-drive array, the layout and chunk size can be changed 5523 * immediately as not restriping is needed. 5524 * For larger arrays we record the new value - after validation 5525 * to be used by a reshape pass. 5526 */ 5527 struct r5conf *conf = mddev->private; 5528 int new_chunk = mddev->new_chunk_sectors; 5529 5530 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) 5531 return -EINVAL; 5532 if (new_chunk > 0) { 5533 if (!is_power_of_2(new_chunk)) 5534 return -EINVAL; 5535 if (new_chunk < (PAGE_SIZE>>9)) 5536 return -EINVAL; 5537 if (mddev->array_sectors & (new_chunk-1)) 5538 /* not factor of array size */ 5539 return -EINVAL; 5540 } 5541 5542 /* They look valid */ 5543 5544 if (mddev->raid_disks == 2) { 5545 /* can make the change immediately */ 5546 if (mddev->new_layout >= 0) { 5547 conf->algorithm = mddev->new_layout; 5548 mddev->layout = mddev->new_layout; 5549 } 5550 if (new_chunk > 0) { 5551 conf->chunk_sectors = new_chunk ; 5552 mddev->chunk_sectors = new_chunk; 5553 } 5554 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5555 md_wakeup_thread(mddev->thread); 5556 } 5557 return check_reshape(mddev); 5558} 5559 5560static int raid6_check_reshape(struct mddev *mddev) 5561{ 5562 int new_chunk = mddev->new_chunk_sectors; 5563 5564 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) 5565 return -EINVAL; 5566 if (new_chunk > 0) { 5567 if (!is_power_of_2(new_chunk)) 5568 return -EINVAL; 5569 if (new_chunk < (PAGE_SIZE >> 9)) 5570 return -EINVAL; 5571 if (mddev->array_sectors & (new_chunk-1)) 5572 /* not factor of array size */ 5573 return -EINVAL; 5574 } 5575 5576 /* They look valid */ 5577 return check_reshape(mddev); 5578} 5579 5580static void *raid5_takeover(struct mddev *mddev) 5581{ 5582 /* raid5 can take over: 5583 * raid0 - if there is only one strip zone - make it a raid4 layout 5584 * raid1 - if there are two drives. We need to know the chunk size 5585 * raid4 - trivial - just use a raid4 layout. 5586 * raid6 - Providing it is a *_6 layout 5587 */ 5588 if (mddev->level == 0) 5589 return raid45_takeover_raid0(mddev, 5); 5590 if (mddev->level == 1) 5591 return raid5_takeover_raid1(mddev); 5592 if (mddev->level == 4) { 5593 mddev->new_layout = ALGORITHM_PARITY_N; 5594 mddev->new_level = 5; 5595 return setup_conf(mddev); 5596 } 5597 if (mddev->level == 6) 5598 return raid5_takeover_raid6(mddev); 5599 5600 return ERR_PTR(-EINVAL); 5601} 5602 5603static void *raid4_takeover(struct mddev *mddev) 5604{ 5605 /* raid4 can take over: 5606 * raid0 - if there is only one strip zone 5607 * raid5 - if layout is right 5608 */ 5609 if (mddev->level == 0) 5610 return raid45_takeover_raid0(mddev, 4); 5611 if (mddev->level == 5 && 5612 mddev->layout == ALGORITHM_PARITY_N) { 5613 mddev->new_layout = 0; 5614 mddev->new_level = 4; 5615 return setup_conf(mddev); 5616 } 5617 return ERR_PTR(-EINVAL); 5618} 5619 5620static struct md_personality raid5_personality; 5621 5622static void *raid6_takeover(struct mddev *mddev) 5623{ 5624 /* Currently can only take over a raid5. We map the 5625 * personality to an equivalent raid6 personality 5626 * with the Q block at the end. 5627 */ 5628 int new_layout; 5629 5630 if (mddev->pers != &raid5_personality) 5631 return ERR_PTR(-EINVAL); 5632 if (mddev->degraded > 1) 5633 return ERR_PTR(-EINVAL); 5634 if (mddev->raid_disks > 253) 5635 return ERR_PTR(-EINVAL); 5636 if (mddev->raid_disks < 3) 5637 return ERR_PTR(-EINVAL); 5638 5639 switch (mddev->layout) { 5640 case ALGORITHM_LEFT_ASYMMETRIC: 5641 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; 5642 break; 5643 case ALGORITHM_RIGHT_ASYMMETRIC: 5644 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; 5645 break; 5646 case ALGORITHM_LEFT_SYMMETRIC: 5647 new_layout = ALGORITHM_LEFT_SYMMETRIC_6; 5648 break; 5649 case ALGORITHM_RIGHT_SYMMETRIC: 5650 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; 5651 break; 5652 case ALGORITHM_PARITY_0: 5653 new_layout = ALGORITHM_PARITY_0_6; 5654 break; 5655 case ALGORITHM_PARITY_N: 5656 new_layout = ALGORITHM_PARITY_N; 5657 break; 5658 default: 5659 return ERR_PTR(-EINVAL); 5660 } 5661 mddev->new_level = 6; 5662 mddev->new_layout = new_layout; 5663 mddev->delta_disks = 1; 5664 mddev->raid_disks += 1; 5665 return setup_conf(mddev); 5666} 5667 5668 5669static struct md_personality raid6_personality = 5670{ 5671 .name = "raid6", 5672 .level = 6, 5673 .owner = THIS_MODULE, 5674 .make_request = make_request, 5675 .run = run, 5676 .stop = stop, 5677 .status = status, 5678 .error_handler = error, 5679 .hot_add_disk = raid5_add_disk, 5680 .hot_remove_disk= raid5_remove_disk, 5681 .spare_active = raid5_spare_active, 5682 .sync_request = sync_request, 5683 .resize = raid5_resize, 5684 .size = raid5_size, 5685 .check_reshape = raid6_check_reshape, 5686 .start_reshape = raid5_start_reshape, 5687 .finish_reshape = raid5_finish_reshape, 5688 .quiesce = raid5_quiesce, 5689 .takeover = raid6_takeover, 5690}; 5691static struct md_personality raid5_personality = 5692{ 5693 .name = "raid5", 5694 .level = 5, 5695 .owner = THIS_MODULE, 5696 .make_request = make_request, 5697 .run = run, 5698 .stop = stop, 5699 .status = status, 5700 .error_handler = error, 5701 .hot_add_disk = raid5_add_disk, 5702 .hot_remove_disk= raid5_remove_disk, 5703 .spare_active = raid5_spare_active, 5704 .sync_request = sync_request, 5705 .resize = raid5_resize, 5706 .size = raid5_size, 5707 .check_reshape = raid5_check_reshape, 5708 .start_reshape = raid5_start_reshape, 5709 .finish_reshape = raid5_finish_reshape, 5710 .quiesce = raid5_quiesce, 5711 .takeover = raid5_takeover, 5712}; 5713 5714static struct md_personality raid4_personality = 5715{ 5716 .name = "raid4", 5717 .level = 4, 5718 .owner = THIS_MODULE, 5719 .make_request = make_request, 5720 .run = run, 5721 .stop = stop, 5722 .status = status, 5723 .error_handler = error, 5724 .hot_add_disk = raid5_add_disk, 5725 .hot_remove_disk= raid5_remove_disk, 5726 .spare_active = raid5_spare_active, 5727 .sync_request = sync_request, 5728 .resize = raid5_resize, 5729 .size = raid5_size, 5730 .check_reshape = raid5_check_reshape, 5731 .start_reshape = raid5_start_reshape, 5732 .finish_reshape = raid5_finish_reshape, 5733 .quiesce = raid5_quiesce, 5734 .takeover = raid4_takeover, 5735}; 5736 5737static int __init raid5_init(void) 5738{ 5739 register_md_personality(&raid6_personality); 5740 register_md_personality(&raid5_personality); 5741 register_md_personality(&raid4_personality); 5742 return 0; 5743} 5744 5745static void raid5_exit(void) 5746{ 5747 unregister_md_personality(&raid6_personality); 5748 unregister_md_personality(&raid5_personality); 5749 unregister_md_personality(&raid4_personality); 5750} 5751 5752module_init(raid5_init); 5753module_exit(raid5_exit); 5754MODULE_LICENSE("GPL"); 5755MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD"); 5756MODULE_ALIAS("md-personality-4"); /* RAID5 */ 5757MODULE_ALIAS("md-raid5"); 5758MODULE_ALIAS("md-raid4"); 5759MODULE_ALIAS("md-level-5"); 5760MODULE_ALIAS("md-level-4"); 5761MODULE_ALIAS("md-personality-8"); /* RAID6 */ 5762MODULE_ALIAS("md-raid6"); 5763MODULE_ALIAS("md-level-6"); 5764 5765/* This used to be two separate modules, they were: */ 5766MODULE_ALIAS("raid5"); 5767MODULE_ALIAS("raid6"); 5768