raid5.c revision acfe726bdd0000a9be1b308b29fad1e9ae62178c
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/async.h> 51#include <linux/seq_file.h> 52#include <linux/cpu.h> 53#include <linux/slab.h> 54#include "md.h" 55#include "raid5.h" 56#include "raid0.h" 57#include "bitmap.h" 58 59/* 60 * Stripe cache 61 */ 62 63#define NR_STRIPES 256 64#define STRIPE_SIZE PAGE_SIZE 65#define STRIPE_SHIFT (PAGE_SHIFT - 9) 66#define STRIPE_SECTORS (STRIPE_SIZE>>9) 67#define IO_THRESHOLD 1 68#define BYPASS_THRESHOLD 1 69#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) 70#define HASH_MASK (NR_HASH - 1) 71 72#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) 73 74/* bio's attached to a stripe+device for I/O are linked together in bi_sector 75 * order without overlap. There may be several bio's per stripe+device, and 76 * a bio could span several devices. 77 * When walking this list for a particular stripe+device, we must never proceed 78 * beyond a bio that extends past this device, as the next bio might no longer 79 * be valid. 80 * This macro is used to determine the 'next' bio in the list, given the sector 81 * of the current stripe+device 82 */ 83#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) 84/* 85 * The following can be used to debug the driver 86 */ 87#define RAID5_PARANOIA 1 88#if RAID5_PARANOIA && defined(CONFIG_SMP) 89# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) 90#else 91# define CHECK_DEVLOCK() 92#endif 93 94#ifdef DEBUG 95#define inline 96#define __inline__ 97#endif 98 99#define printk_rl(args...) ((void) (printk_ratelimit() && printk(args))) 100 101/* 102 * We maintain a biased count of active stripes in the bottom 16 bits of 103 * bi_phys_segments, and a count of processed stripes in the upper 16 bits 104 */ 105static inline int raid5_bi_phys_segments(struct bio *bio) 106{ 107 return bio->bi_phys_segments & 0xffff; 108} 109 110static inline int raid5_bi_hw_segments(struct bio *bio) 111{ 112 return (bio->bi_phys_segments >> 16) & 0xffff; 113} 114 115static inline int raid5_dec_bi_phys_segments(struct bio *bio) 116{ 117 --bio->bi_phys_segments; 118 return raid5_bi_phys_segments(bio); 119} 120 121static inline int raid5_dec_bi_hw_segments(struct bio *bio) 122{ 123 unsigned short val = raid5_bi_hw_segments(bio); 124 125 --val; 126 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); 127 return val; 128} 129 130static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) 131{ 132 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16); 133} 134 135/* Find first data disk in a raid6 stripe */ 136static inline int raid6_d0(struct stripe_head *sh) 137{ 138 if (sh->ddf_layout) 139 /* ddf always start from first device */ 140 return 0; 141 /* md starts just after Q block */ 142 if (sh->qd_idx == sh->disks - 1) 143 return 0; 144 else 145 return sh->qd_idx + 1; 146} 147static inline int raid6_next_disk(int disk, int raid_disks) 148{ 149 disk++; 150 return (disk < raid_disks) ? disk : 0; 151} 152 153/* When walking through the disks in a raid5, starting at raid6_d0, 154 * We need to map each disk to a 'slot', where the data disks are slot 155 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk 156 * is raid_disks-1. This help does that mapping. 157 */ 158static int raid6_idx_to_slot(int idx, struct stripe_head *sh, 159 int *count, int syndrome_disks) 160{ 161 int slot = *count; 162 163 if (sh->ddf_layout) 164 (*count)++; 165 if (idx == sh->pd_idx) 166 return syndrome_disks; 167 if (idx == sh->qd_idx) 168 return syndrome_disks + 1; 169 if (!sh->ddf_layout) 170 (*count)++; 171 return slot; 172} 173 174static void return_io(struct bio *return_bi) 175{ 176 struct bio *bi = return_bi; 177 while (bi) { 178 179 return_bi = bi->bi_next; 180 bi->bi_next = NULL; 181 bi->bi_size = 0; 182 bio_endio(bi, 0); 183 bi = return_bi; 184 } 185} 186 187static void print_raid5_conf (raid5_conf_t *conf); 188 189static int stripe_operations_active(struct stripe_head *sh) 190{ 191 return sh->check_state || sh->reconstruct_state || 192 test_bit(STRIPE_BIOFILL_RUN, &sh->state) || 193 test_bit(STRIPE_COMPUTE_RUN, &sh->state); 194} 195 196static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) 197{ 198 if (atomic_dec_and_test(&sh->count)) { 199 BUG_ON(!list_empty(&sh->lru)); 200 BUG_ON(atomic_read(&conf->active_stripes)==0); 201 if (test_bit(STRIPE_HANDLE, &sh->state)) { 202 if (test_bit(STRIPE_DELAYED, &sh->state)) 203 list_add_tail(&sh->lru, &conf->delayed_list); 204 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && 205 sh->bm_seq - conf->seq_write > 0) 206 list_add_tail(&sh->lru, &conf->bitmap_list); 207 else { 208 clear_bit(STRIPE_BIT_DELAY, &sh->state); 209 list_add_tail(&sh->lru, &conf->handle_list); 210 } 211 md_wakeup_thread(conf->mddev->thread); 212 } else { 213 BUG_ON(stripe_operations_active(sh)); 214 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 215 atomic_dec(&conf->preread_active_stripes); 216 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 217 md_wakeup_thread(conf->mddev->thread); 218 } 219 atomic_dec(&conf->active_stripes); 220 if (!test_bit(STRIPE_EXPANDING, &sh->state)) { 221 list_add_tail(&sh->lru, &conf->inactive_list); 222 wake_up(&conf->wait_for_stripe); 223 if (conf->retry_read_aligned) 224 md_wakeup_thread(conf->mddev->thread); 225 } 226 } 227 } 228} 229 230static void release_stripe(struct stripe_head *sh) 231{ 232 raid5_conf_t *conf = sh->raid_conf; 233 unsigned long flags; 234 235 spin_lock_irqsave(&conf->device_lock, flags); 236 __release_stripe(conf, sh); 237 spin_unlock_irqrestore(&conf->device_lock, flags); 238} 239 240static inline void remove_hash(struct stripe_head *sh) 241{ 242 pr_debug("remove_hash(), stripe %llu\n", 243 (unsigned long long)sh->sector); 244 245 hlist_del_init(&sh->hash); 246} 247 248static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) 249{ 250 struct hlist_head *hp = stripe_hash(conf, sh->sector); 251 252 pr_debug("insert_hash(), stripe %llu\n", 253 (unsigned long long)sh->sector); 254 255 CHECK_DEVLOCK(); 256 hlist_add_head(&sh->hash, hp); 257} 258 259 260/* find an idle stripe, make sure it is unhashed, and return it. */ 261static struct stripe_head *get_free_stripe(raid5_conf_t *conf) 262{ 263 struct stripe_head *sh = NULL; 264 struct list_head *first; 265 266 CHECK_DEVLOCK(); 267 if (list_empty(&conf->inactive_list)) 268 goto out; 269 first = conf->inactive_list.next; 270 sh = list_entry(first, struct stripe_head, lru); 271 list_del_init(first); 272 remove_hash(sh); 273 atomic_inc(&conf->active_stripes); 274out: 275 return sh; 276} 277 278static void shrink_buffers(struct stripe_head *sh) 279{ 280 struct page *p; 281 int i; 282 int num = sh->raid_conf->pool_size; 283 284 for (i = 0; i < num ; i++) { 285 p = sh->dev[i].page; 286 if (!p) 287 continue; 288 sh->dev[i].page = NULL; 289 put_page(p); 290 } 291} 292 293static int grow_buffers(struct stripe_head *sh) 294{ 295 int i; 296 int num = sh->raid_conf->pool_size; 297 298 for (i = 0; i < num; i++) { 299 struct page *page; 300 301 if (!(page = alloc_page(GFP_KERNEL))) { 302 return 1; 303 } 304 sh->dev[i].page = page; 305 } 306 return 0; 307} 308 309static void raid5_build_block(struct stripe_head *sh, int i, int previous); 310static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, 311 struct stripe_head *sh); 312 313static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) 314{ 315 raid5_conf_t *conf = sh->raid_conf; 316 int i; 317 318 BUG_ON(atomic_read(&sh->count) != 0); 319 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); 320 BUG_ON(stripe_operations_active(sh)); 321 322 CHECK_DEVLOCK(); 323 pr_debug("init_stripe called, stripe %llu\n", 324 (unsigned long long)sh->sector); 325 326 remove_hash(sh); 327 328 sh->generation = conf->generation - previous; 329 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; 330 sh->sector = sector; 331 stripe_set_idx(sector, conf, previous, sh); 332 sh->state = 0; 333 334 335 for (i = sh->disks; i--; ) { 336 struct r5dev *dev = &sh->dev[i]; 337 338 if (dev->toread || dev->read || dev->towrite || dev->written || 339 test_bit(R5_LOCKED, &dev->flags)) { 340 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", 341 (unsigned long long)sh->sector, i, dev->toread, 342 dev->read, dev->towrite, dev->written, 343 test_bit(R5_LOCKED, &dev->flags)); 344 BUG(); 345 } 346 dev->flags = 0; 347 raid5_build_block(sh, i, previous); 348 } 349 insert_hash(conf, sh); 350} 351 352static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, 353 short generation) 354{ 355 struct stripe_head *sh; 356 struct hlist_node *hn; 357 358 CHECK_DEVLOCK(); 359 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); 360 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) 361 if (sh->sector == sector && sh->generation == generation) 362 return sh; 363 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); 364 return NULL; 365} 366 367/* 368 * Need to check if array has failed when deciding whether to: 369 * - start an array 370 * - remove non-faulty devices 371 * - add a spare 372 * - allow a reshape 373 * This determination is simple when no reshape is happening. 374 * However if there is a reshape, we need to carefully check 375 * both the before and after sections. 376 * This is because some failed devices may only affect one 377 * of the two sections, and some non-in_sync devices may 378 * be insync in the section most affected by failed devices. 379 */ 380static int has_failed(raid5_conf_t *conf) 381{ 382 int degraded; 383 int i; 384 if (conf->mddev->reshape_position == MaxSector) 385 return conf->mddev->degraded > conf->max_degraded; 386 387 rcu_read_lock(); 388 degraded = 0; 389 for (i = 0; i < conf->previous_raid_disks; i++) { 390 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 391 if (!rdev || test_bit(Faulty, &rdev->flags)) 392 degraded++; 393 else if (test_bit(In_sync, &rdev->flags)) 394 ; 395 else 396 /* not in-sync or faulty. 397 * If the reshape increases the number of devices, 398 * this is being recovered by the reshape, so 399 * this 'previous' section is not in_sync. 400 * If the number of devices is being reduced however, 401 * the device can only be part of the array if 402 * we are reverting a reshape, so this section will 403 * be in-sync. 404 */ 405 if (conf->raid_disks >= conf->previous_raid_disks) 406 degraded++; 407 } 408 rcu_read_unlock(); 409 if (degraded > conf->max_degraded) 410 return 1; 411 rcu_read_lock(); 412 degraded = 0; 413 for (i = 0; i < conf->raid_disks; i++) { 414 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 415 if (!rdev || test_bit(Faulty, &rdev->flags)) 416 degraded++; 417 else if (test_bit(In_sync, &rdev->flags)) 418 ; 419 else 420 /* not in-sync or faulty. 421 * If reshape increases the number of devices, this 422 * section has already been recovered, else it 423 * almost certainly hasn't. 424 */ 425 if (conf->raid_disks <= conf->previous_raid_disks) 426 degraded++; 427 } 428 rcu_read_unlock(); 429 if (degraded > conf->max_degraded) 430 return 1; 431 return 0; 432} 433 434static struct stripe_head * 435get_active_stripe(raid5_conf_t *conf, sector_t sector, 436 int previous, int noblock, int noquiesce) 437{ 438 struct stripe_head *sh; 439 440 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); 441 442 spin_lock_irq(&conf->device_lock); 443 444 do { 445 wait_event_lock_irq(conf->wait_for_stripe, 446 conf->quiesce == 0 || noquiesce, 447 conf->device_lock, /* nothing */); 448 sh = __find_stripe(conf, sector, conf->generation - previous); 449 if (!sh) { 450 if (!conf->inactive_blocked) 451 sh = get_free_stripe(conf); 452 if (noblock && sh == NULL) 453 break; 454 if (!sh) { 455 conf->inactive_blocked = 1; 456 wait_event_lock_irq(conf->wait_for_stripe, 457 !list_empty(&conf->inactive_list) && 458 (atomic_read(&conf->active_stripes) 459 < (conf->max_nr_stripes *3/4) 460 || !conf->inactive_blocked), 461 conf->device_lock, 462 ); 463 conf->inactive_blocked = 0; 464 } else 465 init_stripe(sh, sector, previous); 466 } else { 467 if (atomic_read(&sh->count)) { 468 BUG_ON(!list_empty(&sh->lru) 469 && !test_bit(STRIPE_EXPANDING, &sh->state)); 470 } else { 471 if (!test_bit(STRIPE_HANDLE, &sh->state)) 472 atomic_inc(&conf->active_stripes); 473 if (list_empty(&sh->lru) && 474 !test_bit(STRIPE_EXPANDING, &sh->state)) 475 BUG(); 476 list_del_init(&sh->lru); 477 } 478 } 479 } while (sh == NULL); 480 481 if (sh) 482 atomic_inc(&sh->count); 483 484 spin_unlock_irq(&conf->device_lock); 485 return sh; 486} 487 488static void 489raid5_end_read_request(struct bio *bi, int error); 490static void 491raid5_end_write_request(struct bio *bi, int error); 492 493static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 494{ 495 raid5_conf_t *conf = sh->raid_conf; 496 int i, disks = sh->disks; 497 498 might_sleep(); 499 500 for (i = disks; i--; ) { 501 int rw; 502 struct bio *bi; 503 mdk_rdev_t *rdev; 504 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { 505 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) 506 rw = WRITE_FUA; 507 else 508 rw = WRITE; 509 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 510 rw = READ; 511 else 512 continue; 513 514 bi = &sh->dev[i].req; 515 516 bi->bi_rw = rw; 517 if (rw & WRITE) 518 bi->bi_end_io = raid5_end_write_request; 519 else 520 bi->bi_end_io = raid5_end_read_request; 521 522 rcu_read_lock(); 523 rdev = rcu_dereference(conf->disks[i].rdev); 524 if (rdev && test_bit(Faulty, &rdev->flags)) 525 rdev = NULL; 526 if (rdev) 527 atomic_inc(&rdev->nr_pending); 528 rcu_read_unlock(); 529 530 if (rdev) { 531 if (s->syncing || s->expanding || s->expanded) 532 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 533 534 set_bit(STRIPE_IO_STARTED, &sh->state); 535 536 bi->bi_bdev = rdev->bdev; 537 pr_debug("%s: for %llu schedule op %ld on disc %d\n", 538 __func__, (unsigned long long)sh->sector, 539 bi->bi_rw, i); 540 atomic_inc(&sh->count); 541 bi->bi_sector = sh->sector + rdev->data_offset; 542 bi->bi_flags = 1 << BIO_UPTODATE; 543 bi->bi_vcnt = 1; 544 bi->bi_max_vecs = 1; 545 bi->bi_idx = 0; 546 bi->bi_io_vec = &sh->dev[i].vec; 547 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 548 bi->bi_io_vec[0].bv_offset = 0; 549 bi->bi_size = STRIPE_SIZE; 550 bi->bi_next = NULL; 551 if ((rw & WRITE) && 552 test_bit(R5_ReWrite, &sh->dev[i].flags)) 553 atomic_add(STRIPE_SECTORS, 554 &rdev->corrected_errors); 555 generic_make_request(bi); 556 } else { 557 if (rw & WRITE) 558 set_bit(STRIPE_DEGRADED, &sh->state); 559 pr_debug("skip op %ld on disc %d for sector %llu\n", 560 bi->bi_rw, i, (unsigned long long)sh->sector); 561 clear_bit(R5_LOCKED, &sh->dev[i].flags); 562 set_bit(STRIPE_HANDLE, &sh->state); 563 } 564 } 565} 566 567static struct dma_async_tx_descriptor * 568async_copy_data(int frombio, struct bio *bio, struct page *page, 569 sector_t sector, struct dma_async_tx_descriptor *tx) 570{ 571 struct bio_vec *bvl; 572 struct page *bio_page; 573 int i; 574 int page_offset; 575 struct async_submit_ctl submit; 576 enum async_tx_flags flags = 0; 577 578 if (bio->bi_sector >= sector) 579 page_offset = (signed)(bio->bi_sector - sector) * 512; 580 else 581 page_offset = (signed)(sector - bio->bi_sector) * -512; 582 583 if (frombio) 584 flags |= ASYNC_TX_FENCE; 585 init_async_submit(&submit, flags, tx, NULL, NULL, NULL); 586 587 bio_for_each_segment(bvl, bio, i) { 588 int len = bvl->bv_len; 589 int clen; 590 int b_offset = 0; 591 592 if (page_offset < 0) { 593 b_offset = -page_offset; 594 page_offset += b_offset; 595 len -= b_offset; 596 } 597 598 if (len > 0 && page_offset + len > STRIPE_SIZE) 599 clen = STRIPE_SIZE - page_offset; 600 else 601 clen = len; 602 603 if (clen > 0) { 604 b_offset += bvl->bv_offset; 605 bio_page = bvl->bv_page; 606 if (frombio) 607 tx = async_memcpy(page, bio_page, page_offset, 608 b_offset, clen, &submit); 609 else 610 tx = async_memcpy(bio_page, page, b_offset, 611 page_offset, clen, &submit); 612 } 613 /* chain the operations */ 614 submit.depend_tx = tx; 615 616 if (clen < len) /* hit end of page */ 617 break; 618 page_offset += len; 619 } 620 621 return tx; 622} 623 624static void ops_complete_biofill(void *stripe_head_ref) 625{ 626 struct stripe_head *sh = stripe_head_ref; 627 struct bio *return_bi = NULL; 628 raid5_conf_t *conf = sh->raid_conf; 629 int i; 630 631 pr_debug("%s: stripe %llu\n", __func__, 632 (unsigned long long)sh->sector); 633 634 /* clear completed biofills */ 635 spin_lock_irq(&conf->device_lock); 636 for (i = sh->disks; i--; ) { 637 struct r5dev *dev = &sh->dev[i]; 638 639 /* acknowledge completion of a biofill operation */ 640 /* and check if we need to reply to a read request, 641 * new R5_Wantfill requests are held off until 642 * !STRIPE_BIOFILL_RUN 643 */ 644 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { 645 struct bio *rbi, *rbi2; 646 647 BUG_ON(!dev->read); 648 rbi = dev->read; 649 dev->read = NULL; 650 while (rbi && rbi->bi_sector < 651 dev->sector + STRIPE_SECTORS) { 652 rbi2 = r5_next_bio(rbi, dev->sector); 653 if (!raid5_dec_bi_phys_segments(rbi)) { 654 rbi->bi_next = return_bi; 655 return_bi = rbi; 656 } 657 rbi = rbi2; 658 } 659 } 660 } 661 spin_unlock_irq(&conf->device_lock); 662 clear_bit(STRIPE_BIOFILL_RUN, &sh->state); 663 664 return_io(return_bi); 665 666 set_bit(STRIPE_HANDLE, &sh->state); 667 release_stripe(sh); 668} 669 670static void ops_run_biofill(struct stripe_head *sh) 671{ 672 struct dma_async_tx_descriptor *tx = NULL; 673 raid5_conf_t *conf = sh->raid_conf; 674 struct async_submit_ctl submit; 675 int i; 676 677 pr_debug("%s: stripe %llu\n", __func__, 678 (unsigned long long)sh->sector); 679 680 for (i = sh->disks; i--; ) { 681 struct r5dev *dev = &sh->dev[i]; 682 if (test_bit(R5_Wantfill, &dev->flags)) { 683 struct bio *rbi; 684 spin_lock_irq(&conf->device_lock); 685 dev->read = rbi = dev->toread; 686 dev->toread = NULL; 687 spin_unlock_irq(&conf->device_lock); 688 while (rbi && rbi->bi_sector < 689 dev->sector + STRIPE_SECTORS) { 690 tx = async_copy_data(0, rbi, dev->page, 691 dev->sector, tx); 692 rbi = r5_next_bio(rbi, dev->sector); 693 } 694 } 695 } 696 697 atomic_inc(&sh->count); 698 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); 699 async_trigger_callback(&submit); 700} 701 702static void mark_target_uptodate(struct stripe_head *sh, int target) 703{ 704 struct r5dev *tgt; 705 706 if (target < 0) 707 return; 708 709 tgt = &sh->dev[target]; 710 set_bit(R5_UPTODATE, &tgt->flags); 711 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 712 clear_bit(R5_Wantcompute, &tgt->flags); 713} 714 715static void ops_complete_compute(void *stripe_head_ref) 716{ 717 struct stripe_head *sh = stripe_head_ref; 718 719 pr_debug("%s: stripe %llu\n", __func__, 720 (unsigned long long)sh->sector); 721 722 /* mark the computed target(s) as uptodate */ 723 mark_target_uptodate(sh, sh->ops.target); 724 mark_target_uptodate(sh, sh->ops.target2); 725 726 clear_bit(STRIPE_COMPUTE_RUN, &sh->state); 727 if (sh->check_state == check_state_compute_run) 728 sh->check_state = check_state_compute_result; 729 set_bit(STRIPE_HANDLE, &sh->state); 730 release_stripe(sh); 731} 732 733/* return a pointer to the address conversion region of the scribble buffer */ 734static addr_conv_t *to_addr_conv(struct stripe_head *sh, 735 struct raid5_percpu *percpu) 736{ 737 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); 738} 739 740static struct dma_async_tx_descriptor * 741ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 742{ 743 int disks = sh->disks; 744 struct page **xor_srcs = percpu->scribble; 745 int target = sh->ops.target; 746 struct r5dev *tgt = &sh->dev[target]; 747 struct page *xor_dest = tgt->page; 748 int count = 0; 749 struct dma_async_tx_descriptor *tx; 750 struct async_submit_ctl submit; 751 int i; 752 753 pr_debug("%s: stripe %llu block: %d\n", 754 __func__, (unsigned long long)sh->sector, target); 755 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 756 757 for (i = disks; i--; ) 758 if (i != target) 759 xor_srcs[count++] = sh->dev[i].page; 760 761 atomic_inc(&sh->count); 762 763 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, 764 ops_complete_compute, sh, to_addr_conv(sh, percpu)); 765 if (unlikely(count == 1)) 766 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 767 else 768 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 769 770 return tx; 771} 772 773/* set_syndrome_sources - populate source buffers for gen_syndrome 774 * @srcs - (struct page *) array of size sh->disks 775 * @sh - stripe_head to parse 776 * 777 * Populates srcs in proper layout order for the stripe and returns the 778 * 'count' of sources to be used in a call to async_gen_syndrome. The P 779 * destination buffer is recorded in srcs[count] and the Q destination 780 * is recorded in srcs[count+1]]. 781 */ 782static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) 783{ 784 int disks = sh->disks; 785 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); 786 int d0_idx = raid6_d0(sh); 787 int count; 788 int i; 789 790 for (i = 0; i < disks; i++) 791 srcs[i] = NULL; 792 793 count = 0; 794 i = d0_idx; 795 do { 796 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 797 798 srcs[slot] = sh->dev[i].page; 799 i = raid6_next_disk(i, disks); 800 } while (i != d0_idx); 801 802 return syndrome_disks; 803} 804 805static struct dma_async_tx_descriptor * 806ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) 807{ 808 int disks = sh->disks; 809 struct page **blocks = percpu->scribble; 810 int target; 811 int qd_idx = sh->qd_idx; 812 struct dma_async_tx_descriptor *tx; 813 struct async_submit_ctl submit; 814 struct r5dev *tgt; 815 struct page *dest; 816 int i; 817 int count; 818 819 if (sh->ops.target < 0) 820 target = sh->ops.target2; 821 else if (sh->ops.target2 < 0) 822 target = sh->ops.target; 823 else 824 /* we should only have one valid target */ 825 BUG(); 826 BUG_ON(target < 0); 827 pr_debug("%s: stripe %llu block: %d\n", 828 __func__, (unsigned long long)sh->sector, target); 829 830 tgt = &sh->dev[target]; 831 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 832 dest = tgt->page; 833 834 atomic_inc(&sh->count); 835 836 if (target == qd_idx) { 837 count = set_syndrome_sources(blocks, sh); 838 blocks[count] = NULL; /* regenerating p is not necessary */ 839 BUG_ON(blocks[count+1] != dest); /* q should already be set */ 840 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 841 ops_complete_compute, sh, 842 to_addr_conv(sh, percpu)); 843 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 844 } else { 845 /* Compute any data- or p-drive using XOR */ 846 count = 0; 847 for (i = disks; i-- ; ) { 848 if (i == target || i == qd_idx) 849 continue; 850 blocks[count++] = sh->dev[i].page; 851 } 852 853 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 854 NULL, ops_complete_compute, sh, 855 to_addr_conv(sh, percpu)); 856 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); 857 } 858 859 return tx; 860} 861 862static struct dma_async_tx_descriptor * 863ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) 864{ 865 int i, count, disks = sh->disks; 866 int syndrome_disks = sh->ddf_layout ? disks : disks-2; 867 int d0_idx = raid6_d0(sh); 868 int faila = -1, failb = -1; 869 int target = sh->ops.target; 870 int target2 = sh->ops.target2; 871 struct r5dev *tgt = &sh->dev[target]; 872 struct r5dev *tgt2 = &sh->dev[target2]; 873 struct dma_async_tx_descriptor *tx; 874 struct page **blocks = percpu->scribble; 875 struct async_submit_ctl submit; 876 877 pr_debug("%s: stripe %llu block1: %d block2: %d\n", 878 __func__, (unsigned long long)sh->sector, target, target2); 879 BUG_ON(target < 0 || target2 < 0); 880 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 881 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); 882 883 /* we need to open-code set_syndrome_sources to handle the 884 * slot number conversion for 'faila' and 'failb' 885 */ 886 for (i = 0; i < disks ; i++) 887 blocks[i] = NULL; 888 count = 0; 889 i = d0_idx; 890 do { 891 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 892 893 blocks[slot] = sh->dev[i].page; 894 895 if (i == target) 896 faila = slot; 897 if (i == target2) 898 failb = slot; 899 i = raid6_next_disk(i, disks); 900 } while (i != d0_idx); 901 902 BUG_ON(faila == failb); 903 if (failb < faila) 904 swap(faila, failb); 905 pr_debug("%s: stripe: %llu faila: %d failb: %d\n", 906 __func__, (unsigned long long)sh->sector, faila, failb); 907 908 atomic_inc(&sh->count); 909 910 if (failb == syndrome_disks+1) { 911 /* Q disk is one of the missing disks */ 912 if (faila == syndrome_disks) { 913 /* Missing P+Q, just recompute */ 914 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 915 ops_complete_compute, sh, 916 to_addr_conv(sh, percpu)); 917 return async_gen_syndrome(blocks, 0, syndrome_disks+2, 918 STRIPE_SIZE, &submit); 919 } else { 920 struct page *dest; 921 int data_target; 922 int qd_idx = sh->qd_idx; 923 924 /* Missing D+Q: recompute D from P, then recompute Q */ 925 if (target == qd_idx) 926 data_target = target2; 927 else 928 data_target = target; 929 930 count = 0; 931 for (i = disks; i-- ; ) { 932 if (i == data_target || i == qd_idx) 933 continue; 934 blocks[count++] = sh->dev[i].page; 935 } 936 dest = sh->dev[data_target].page; 937 init_async_submit(&submit, 938 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 939 NULL, NULL, NULL, 940 to_addr_conv(sh, percpu)); 941 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, 942 &submit); 943 944 count = set_syndrome_sources(blocks, sh); 945 init_async_submit(&submit, ASYNC_TX_FENCE, tx, 946 ops_complete_compute, sh, 947 to_addr_conv(sh, percpu)); 948 return async_gen_syndrome(blocks, 0, count+2, 949 STRIPE_SIZE, &submit); 950 } 951 } else { 952 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 953 ops_complete_compute, sh, 954 to_addr_conv(sh, percpu)); 955 if (failb == syndrome_disks) { 956 /* We're missing D+P. */ 957 return async_raid6_datap_recov(syndrome_disks+2, 958 STRIPE_SIZE, faila, 959 blocks, &submit); 960 } else { 961 /* We're missing D+D. */ 962 return async_raid6_2data_recov(syndrome_disks+2, 963 STRIPE_SIZE, faila, failb, 964 blocks, &submit); 965 } 966 } 967} 968 969 970static void ops_complete_prexor(void *stripe_head_ref) 971{ 972 struct stripe_head *sh = stripe_head_ref; 973 974 pr_debug("%s: stripe %llu\n", __func__, 975 (unsigned long long)sh->sector); 976} 977 978static struct dma_async_tx_descriptor * 979ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu, 980 struct dma_async_tx_descriptor *tx) 981{ 982 int disks = sh->disks; 983 struct page **xor_srcs = percpu->scribble; 984 int count = 0, pd_idx = sh->pd_idx, i; 985 struct async_submit_ctl submit; 986 987 /* existing parity data subtracted */ 988 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 989 990 pr_debug("%s: stripe %llu\n", __func__, 991 (unsigned long long)sh->sector); 992 993 for (i = disks; i--; ) { 994 struct r5dev *dev = &sh->dev[i]; 995 /* Only process blocks that are known to be uptodate */ 996 if (test_bit(R5_Wantdrain, &dev->flags)) 997 xor_srcs[count++] = dev->page; 998 } 999 1000 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, 1001 ops_complete_prexor, sh, to_addr_conv(sh, percpu)); 1002 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1003 1004 return tx; 1005} 1006 1007static struct dma_async_tx_descriptor * 1008ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 1009{ 1010 int disks = sh->disks; 1011 int i; 1012 1013 pr_debug("%s: stripe %llu\n", __func__, 1014 (unsigned long long)sh->sector); 1015 1016 for (i = disks; i--; ) { 1017 struct r5dev *dev = &sh->dev[i]; 1018 struct bio *chosen; 1019 1020 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { 1021 struct bio *wbi; 1022 1023 spin_lock_irq(&sh->raid_conf->device_lock); 1024 chosen = dev->towrite; 1025 dev->towrite = NULL; 1026 BUG_ON(dev->written); 1027 wbi = dev->written = chosen; 1028 spin_unlock_irq(&sh->raid_conf->device_lock); 1029 1030 while (wbi && wbi->bi_sector < 1031 dev->sector + STRIPE_SECTORS) { 1032 if (wbi->bi_rw & REQ_FUA) 1033 set_bit(R5_WantFUA, &dev->flags); 1034 tx = async_copy_data(1, wbi, dev->page, 1035 dev->sector, tx); 1036 wbi = r5_next_bio(wbi, dev->sector); 1037 } 1038 } 1039 } 1040 1041 return tx; 1042} 1043 1044static void ops_complete_reconstruct(void *stripe_head_ref) 1045{ 1046 struct stripe_head *sh = stripe_head_ref; 1047 int disks = sh->disks; 1048 int pd_idx = sh->pd_idx; 1049 int qd_idx = sh->qd_idx; 1050 int i; 1051 bool fua = false; 1052 1053 pr_debug("%s: stripe %llu\n", __func__, 1054 (unsigned long long)sh->sector); 1055 1056 for (i = disks; i--; ) 1057 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); 1058 1059 for (i = disks; i--; ) { 1060 struct r5dev *dev = &sh->dev[i]; 1061 1062 if (dev->written || i == pd_idx || i == qd_idx) { 1063 set_bit(R5_UPTODATE, &dev->flags); 1064 if (fua) 1065 set_bit(R5_WantFUA, &dev->flags); 1066 } 1067 } 1068 1069 if (sh->reconstruct_state == reconstruct_state_drain_run) 1070 sh->reconstruct_state = reconstruct_state_drain_result; 1071 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) 1072 sh->reconstruct_state = reconstruct_state_prexor_drain_result; 1073 else { 1074 BUG_ON(sh->reconstruct_state != reconstruct_state_run); 1075 sh->reconstruct_state = reconstruct_state_result; 1076 } 1077 1078 set_bit(STRIPE_HANDLE, &sh->state); 1079 release_stripe(sh); 1080} 1081 1082static void 1083ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 1084 struct dma_async_tx_descriptor *tx) 1085{ 1086 int disks = sh->disks; 1087 struct page **xor_srcs = percpu->scribble; 1088 struct async_submit_ctl submit; 1089 int count = 0, pd_idx = sh->pd_idx, i; 1090 struct page *xor_dest; 1091 int prexor = 0; 1092 unsigned long flags; 1093 1094 pr_debug("%s: stripe %llu\n", __func__, 1095 (unsigned long long)sh->sector); 1096 1097 /* check if prexor is active which means only process blocks 1098 * that are part of a read-modify-write (written) 1099 */ 1100 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { 1101 prexor = 1; 1102 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1103 for (i = disks; i--; ) { 1104 struct r5dev *dev = &sh->dev[i]; 1105 if (dev->written) 1106 xor_srcs[count++] = dev->page; 1107 } 1108 } else { 1109 xor_dest = sh->dev[pd_idx].page; 1110 for (i = disks; i--; ) { 1111 struct r5dev *dev = &sh->dev[i]; 1112 if (i != pd_idx) 1113 xor_srcs[count++] = dev->page; 1114 } 1115 } 1116 1117 /* 1/ if we prexor'd then the dest is reused as a source 1118 * 2/ if we did not prexor then we are redoing the parity 1119 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST 1120 * for the synchronous xor case 1121 */ 1122 flags = ASYNC_TX_ACK | 1123 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); 1124 1125 atomic_inc(&sh->count); 1126 1127 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, 1128 to_addr_conv(sh, percpu)); 1129 if (unlikely(count == 1)) 1130 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 1131 else 1132 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1133} 1134 1135static void 1136ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, 1137 struct dma_async_tx_descriptor *tx) 1138{ 1139 struct async_submit_ctl submit; 1140 struct page **blocks = percpu->scribble; 1141 int count; 1142 1143 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); 1144 1145 count = set_syndrome_sources(blocks, sh); 1146 1147 atomic_inc(&sh->count); 1148 1149 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, 1150 sh, to_addr_conv(sh, percpu)); 1151 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 1152} 1153 1154static void ops_complete_check(void *stripe_head_ref) 1155{ 1156 struct stripe_head *sh = stripe_head_ref; 1157 1158 pr_debug("%s: stripe %llu\n", __func__, 1159 (unsigned long long)sh->sector); 1160 1161 sh->check_state = check_state_check_result; 1162 set_bit(STRIPE_HANDLE, &sh->state); 1163 release_stripe(sh); 1164} 1165 1166static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) 1167{ 1168 int disks = sh->disks; 1169 int pd_idx = sh->pd_idx; 1170 int qd_idx = sh->qd_idx; 1171 struct page *xor_dest; 1172 struct page **xor_srcs = percpu->scribble; 1173 struct dma_async_tx_descriptor *tx; 1174 struct async_submit_ctl submit; 1175 int count; 1176 int i; 1177 1178 pr_debug("%s: stripe %llu\n", __func__, 1179 (unsigned long long)sh->sector); 1180 1181 count = 0; 1182 xor_dest = sh->dev[pd_idx].page; 1183 xor_srcs[count++] = xor_dest; 1184 for (i = disks; i--; ) { 1185 if (i == pd_idx || i == qd_idx) 1186 continue; 1187 xor_srcs[count++] = sh->dev[i].page; 1188 } 1189 1190 init_async_submit(&submit, 0, NULL, NULL, NULL, 1191 to_addr_conv(sh, percpu)); 1192 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, 1193 &sh->ops.zero_sum_result, &submit); 1194 1195 atomic_inc(&sh->count); 1196 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); 1197 tx = async_trigger_callback(&submit); 1198} 1199 1200static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) 1201{ 1202 struct page **srcs = percpu->scribble; 1203 struct async_submit_ctl submit; 1204 int count; 1205 1206 pr_debug("%s: stripe %llu checkp: %d\n", __func__, 1207 (unsigned long long)sh->sector, checkp); 1208 1209 count = set_syndrome_sources(srcs, sh); 1210 if (!checkp) 1211 srcs[count] = NULL; 1212 1213 atomic_inc(&sh->count); 1214 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, 1215 sh, to_addr_conv(sh, percpu)); 1216 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, 1217 &sh->ops.zero_sum_result, percpu->spare_page, &submit); 1218} 1219 1220static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1221{ 1222 int overlap_clear = 0, i, disks = sh->disks; 1223 struct dma_async_tx_descriptor *tx = NULL; 1224 raid5_conf_t *conf = sh->raid_conf; 1225 int level = conf->level; 1226 struct raid5_percpu *percpu; 1227 unsigned long cpu; 1228 1229 cpu = get_cpu(); 1230 percpu = per_cpu_ptr(conf->percpu, cpu); 1231 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { 1232 ops_run_biofill(sh); 1233 overlap_clear++; 1234 } 1235 1236 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { 1237 if (level < 6) 1238 tx = ops_run_compute5(sh, percpu); 1239 else { 1240 if (sh->ops.target2 < 0 || sh->ops.target < 0) 1241 tx = ops_run_compute6_1(sh, percpu); 1242 else 1243 tx = ops_run_compute6_2(sh, percpu); 1244 } 1245 /* terminate the chain if reconstruct is not set to be run */ 1246 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) 1247 async_tx_ack(tx); 1248 } 1249 1250 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) 1251 tx = ops_run_prexor(sh, percpu, tx); 1252 1253 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { 1254 tx = ops_run_biodrain(sh, tx); 1255 overlap_clear++; 1256 } 1257 1258 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { 1259 if (level < 6) 1260 ops_run_reconstruct5(sh, percpu, tx); 1261 else 1262 ops_run_reconstruct6(sh, percpu, tx); 1263 } 1264 1265 if (test_bit(STRIPE_OP_CHECK, &ops_request)) { 1266 if (sh->check_state == check_state_run) 1267 ops_run_check_p(sh, percpu); 1268 else if (sh->check_state == check_state_run_q) 1269 ops_run_check_pq(sh, percpu, 0); 1270 else if (sh->check_state == check_state_run_pq) 1271 ops_run_check_pq(sh, percpu, 1); 1272 else 1273 BUG(); 1274 } 1275 1276 if (overlap_clear) 1277 for (i = disks; i--; ) { 1278 struct r5dev *dev = &sh->dev[i]; 1279 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1280 wake_up(&sh->raid_conf->wait_for_overlap); 1281 } 1282 put_cpu(); 1283} 1284 1285#ifdef CONFIG_MULTICORE_RAID456 1286static void async_run_ops(void *param, async_cookie_t cookie) 1287{ 1288 struct stripe_head *sh = param; 1289 unsigned long ops_request = sh->ops.request; 1290 1291 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); 1292 wake_up(&sh->ops.wait_for_ops); 1293 1294 __raid_run_ops(sh, ops_request); 1295 release_stripe(sh); 1296} 1297 1298static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1299{ 1300 /* since handle_stripe can be called outside of raid5d context 1301 * we need to ensure sh->ops.request is de-staged before another 1302 * request arrives 1303 */ 1304 wait_event(sh->ops.wait_for_ops, 1305 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); 1306 sh->ops.request = ops_request; 1307 1308 atomic_inc(&sh->count); 1309 async_schedule(async_run_ops, sh); 1310} 1311#else 1312#define raid_run_ops __raid_run_ops 1313#endif 1314 1315static int grow_one_stripe(raid5_conf_t *conf) 1316{ 1317 struct stripe_head *sh; 1318 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL); 1319 if (!sh) 1320 return 0; 1321 1322 sh->raid_conf = conf; 1323 #ifdef CONFIG_MULTICORE_RAID456 1324 init_waitqueue_head(&sh->ops.wait_for_ops); 1325 #endif 1326 1327 if (grow_buffers(sh)) { 1328 shrink_buffers(sh); 1329 kmem_cache_free(conf->slab_cache, sh); 1330 return 0; 1331 } 1332 /* we just created an active stripe so... */ 1333 atomic_set(&sh->count, 1); 1334 atomic_inc(&conf->active_stripes); 1335 INIT_LIST_HEAD(&sh->lru); 1336 release_stripe(sh); 1337 return 1; 1338} 1339 1340static int grow_stripes(raid5_conf_t *conf, int num) 1341{ 1342 struct kmem_cache *sc; 1343 int devs = max(conf->raid_disks, conf->previous_raid_disks); 1344 1345 if (conf->mddev->gendisk) 1346 sprintf(conf->cache_name[0], 1347 "raid%d-%s", conf->level, mdname(conf->mddev)); 1348 else 1349 sprintf(conf->cache_name[0], 1350 "raid%d-%p", conf->level, conf->mddev); 1351 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]); 1352 1353 conf->active_name = 0; 1354 sc = kmem_cache_create(conf->cache_name[conf->active_name], 1355 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 1356 0, 0, NULL); 1357 if (!sc) 1358 return 1; 1359 conf->slab_cache = sc; 1360 conf->pool_size = devs; 1361 while (num--) 1362 if (!grow_one_stripe(conf)) 1363 return 1; 1364 return 0; 1365} 1366 1367/** 1368 * scribble_len - return the required size of the scribble region 1369 * @num - total number of disks in the array 1370 * 1371 * The size must be enough to contain: 1372 * 1/ a struct page pointer for each device in the array +2 1373 * 2/ room to convert each entry in (1) to its corresponding dma 1374 * (dma_map_page()) or page (page_address()) address. 1375 * 1376 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we 1377 * calculate over all devices (not just the data blocks), using zeros in place 1378 * of the P and Q blocks. 1379 */ 1380static size_t scribble_len(int num) 1381{ 1382 size_t len; 1383 1384 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); 1385 1386 return len; 1387} 1388 1389static int resize_stripes(raid5_conf_t *conf, int newsize) 1390{ 1391 /* Make all the stripes able to hold 'newsize' devices. 1392 * New slots in each stripe get 'page' set to a new page. 1393 * 1394 * This happens in stages: 1395 * 1/ create a new kmem_cache and allocate the required number of 1396 * stripe_heads. 1397 * 2/ gather all the old stripe_heads and tranfer the pages across 1398 * to the new stripe_heads. This will have the side effect of 1399 * freezing the array as once all stripe_heads have been collected, 1400 * no IO will be possible. Old stripe heads are freed once their 1401 * pages have been transferred over, and the old kmem_cache is 1402 * freed when all stripes are done. 1403 * 3/ reallocate conf->disks to be suitable bigger. If this fails, 1404 * we simple return a failre status - no need to clean anything up. 1405 * 4/ allocate new pages for the new slots in the new stripe_heads. 1406 * If this fails, we don't bother trying the shrink the 1407 * stripe_heads down again, we just leave them as they are. 1408 * As each stripe_head is processed the new one is released into 1409 * active service. 1410 * 1411 * Once step2 is started, we cannot afford to wait for a write, 1412 * so we use GFP_NOIO allocations. 1413 */ 1414 struct stripe_head *osh, *nsh; 1415 LIST_HEAD(newstripes); 1416 struct disk_info *ndisks; 1417 unsigned long cpu; 1418 int err; 1419 struct kmem_cache *sc; 1420 int i; 1421 1422 if (newsize <= conf->pool_size) 1423 return 0; /* never bother to shrink */ 1424 1425 err = md_allow_write(conf->mddev); 1426 if (err) 1427 return err; 1428 1429 /* Step 1 */ 1430 sc = kmem_cache_create(conf->cache_name[1-conf->active_name], 1431 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), 1432 0, 0, NULL); 1433 if (!sc) 1434 return -ENOMEM; 1435 1436 for (i = conf->max_nr_stripes; i; i--) { 1437 nsh = kmem_cache_zalloc(sc, GFP_KERNEL); 1438 if (!nsh) 1439 break; 1440 1441 nsh->raid_conf = conf; 1442 #ifdef CONFIG_MULTICORE_RAID456 1443 init_waitqueue_head(&nsh->ops.wait_for_ops); 1444 #endif 1445 1446 list_add(&nsh->lru, &newstripes); 1447 } 1448 if (i) { 1449 /* didn't get enough, give up */ 1450 while (!list_empty(&newstripes)) { 1451 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1452 list_del(&nsh->lru); 1453 kmem_cache_free(sc, nsh); 1454 } 1455 kmem_cache_destroy(sc); 1456 return -ENOMEM; 1457 } 1458 /* Step 2 - Must use GFP_NOIO now. 1459 * OK, we have enough stripes, start collecting inactive 1460 * stripes and copying them over 1461 */ 1462 list_for_each_entry(nsh, &newstripes, lru) { 1463 spin_lock_irq(&conf->device_lock); 1464 wait_event_lock_irq(conf->wait_for_stripe, 1465 !list_empty(&conf->inactive_list), 1466 conf->device_lock, 1467 ); 1468 osh = get_free_stripe(conf); 1469 spin_unlock_irq(&conf->device_lock); 1470 atomic_set(&nsh->count, 1); 1471 for(i=0; i<conf->pool_size; i++) 1472 nsh->dev[i].page = osh->dev[i].page; 1473 for( ; i<newsize; i++) 1474 nsh->dev[i].page = NULL; 1475 kmem_cache_free(conf->slab_cache, osh); 1476 } 1477 kmem_cache_destroy(conf->slab_cache); 1478 1479 /* Step 3. 1480 * At this point, we are holding all the stripes so the array 1481 * is completely stalled, so now is a good time to resize 1482 * conf->disks and the scribble region 1483 */ 1484 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); 1485 if (ndisks) { 1486 for (i=0; i<conf->raid_disks; i++) 1487 ndisks[i] = conf->disks[i]; 1488 kfree(conf->disks); 1489 conf->disks = ndisks; 1490 } else 1491 err = -ENOMEM; 1492 1493 get_online_cpus(); 1494 conf->scribble_len = scribble_len(newsize); 1495 for_each_present_cpu(cpu) { 1496 struct raid5_percpu *percpu; 1497 void *scribble; 1498 1499 percpu = per_cpu_ptr(conf->percpu, cpu); 1500 scribble = kmalloc(conf->scribble_len, GFP_NOIO); 1501 1502 if (scribble) { 1503 kfree(percpu->scribble); 1504 percpu->scribble = scribble; 1505 } else { 1506 err = -ENOMEM; 1507 break; 1508 } 1509 } 1510 put_online_cpus(); 1511 1512 /* Step 4, return new stripes to service */ 1513 while(!list_empty(&newstripes)) { 1514 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1515 list_del_init(&nsh->lru); 1516 1517 for (i=conf->raid_disks; i < newsize; i++) 1518 if (nsh->dev[i].page == NULL) { 1519 struct page *p = alloc_page(GFP_NOIO); 1520 nsh->dev[i].page = p; 1521 if (!p) 1522 err = -ENOMEM; 1523 } 1524 release_stripe(nsh); 1525 } 1526 /* critical section pass, GFP_NOIO no longer needed */ 1527 1528 conf->slab_cache = sc; 1529 conf->active_name = 1-conf->active_name; 1530 conf->pool_size = newsize; 1531 return err; 1532} 1533 1534static int drop_one_stripe(raid5_conf_t *conf) 1535{ 1536 struct stripe_head *sh; 1537 1538 spin_lock_irq(&conf->device_lock); 1539 sh = get_free_stripe(conf); 1540 spin_unlock_irq(&conf->device_lock); 1541 if (!sh) 1542 return 0; 1543 BUG_ON(atomic_read(&sh->count)); 1544 shrink_buffers(sh); 1545 kmem_cache_free(conf->slab_cache, sh); 1546 atomic_dec(&conf->active_stripes); 1547 return 1; 1548} 1549 1550static void shrink_stripes(raid5_conf_t *conf) 1551{ 1552 while (drop_one_stripe(conf)) 1553 ; 1554 1555 if (conf->slab_cache) 1556 kmem_cache_destroy(conf->slab_cache); 1557 conf->slab_cache = NULL; 1558} 1559 1560static void raid5_end_read_request(struct bio * bi, int error) 1561{ 1562 struct stripe_head *sh = bi->bi_private; 1563 raid5_conf_t *conf = sh->raid_conf; 1564 int disks = sh->disks, i; 1565 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1566 char b[BDEVNAME_SIZE]; 1567 mdk_rdev_t *rdev; 1568 1569 1570 for (i=0 ; i<disks; i++) 1571 if (bi == &sh->dev[i].req) 1572 break; 1573 1574 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", 1575 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1576 uptodate); 1577 if (i == disks) { 1578 BUG(); 1579 return; 1580 } 1581 1582 if (uptodate) { 1583 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1584 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 1585 rdev = conf->disks[i].rdev; 1586 printk_rl(KERN_INFO "md/raid:%s: read error corrected" 1587 " (%lu sectors at %llu on %s)\n", 1588 mdname(conf->mddev), STRIPE_SECTORS, 1589 (unsigned long long)(sh->sector 1590 + rdev->data_offset), 1591 bdevname(rdev->bdev, b)); 1592 clear_bit(R5_ReadError, &sh->dev[i].flags); 1593 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1594 } 1595 if (atomic_read(&conf->disks[i].rdev->read_errors)) 1596 atomic_set(&conf->disks[i].rdev->read_errors, 0); 1597 } else { 1598 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); 1599 int retry = 0; 1600 rdev = conf->disks[i].rdev; 1601 1602 clear_bit(R5_UPTODATE, &sh->dev[i].flags); 1603 atomic_inc(&rdev->read_errors); 1604 if (conf->mddev->degraded >= conf->max_degraded) 1605 printk_rl(KERN_WARNING 1606 "md/raid:%s: read error not correctable " 1607 "(sector %llu on %s).\n", 1608 mdname(conf->mddev), 1609 (unsigned long long)(sh->sector 1610 + rdev->data_offset), 1611 bdn); 1612 else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) 1613 /* Oh, no!!! */ 1614 printk_rl(KERN_WARNING 1615 "md/raid:%s: read error NOT corrected!! " 1616 "(sector %llu on %s).\n", 1617 mdname(conf->mddev), 1618 (unsigned long long)(sh->sector 1619 + rdev->data_offset), 1620 bdn); 1621 else if (atomic_read(&rdev->read_errors) 1622 > conf->max_nr_stripes) 1623 printk(KERN_WARNING 1624 "md/raid:%s: Too many read errors, failing device %s.\n", 1625 mdname(conf->mddev), bdn); 1626 else 1627 retry = 1; 1628 if (retry) 1629 set_bit(R5_ReadError, &sh->dev[i].flags); 1630 else { 1631 clear_bit(R5_ReadError, &sh->dev[i].flags); 1632 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1633 md_error(conf->mddev, rdev); 1634 } 1635 } 1636 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1637 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1638 set_bit(STRIPE_HANDLE, &sh->state); 1639 release_stripe(sh); 1640} 1641 1642static void raid5_end_write_request(struct bio *bi, int error) 1643{ 1644 struct stripe_head *sh = bi->bi_private; 1645 raid5_conf_t *conf = sh->raid_conf; 1646 int disks = sh->disks, i; 1647 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1648 1649 for (i=0 ; i<disks; i++) 1650 if (bi == &sh->dev[i].req) 1651 break; 1652 1653 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", 1654 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1655 uptodate); 1656 if (i == disks) { 1657 BUG(); 1658 return; 1659 } 1660 1661 if (!uptodate) 1662 md_error(conf->mddev, conf->disks[i].rdev); 1663 1664 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1665 1666 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1667 set_bit(STRIPE_HANDLE, &sh->state); 1668 release_stripe(sh); 1669} 1670 1671 1672static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous); 1673 1674static void raid5_build_block(struct stripe_head *sh, int i, int previous) 1675{ 1676 struct r5dev *dev = &sh->dev[i]; 1677 1678 bio_init(&dev->req); 1679 dev->req.bi_io_vec = &dev->vec; 1680 dev->req.bi_vcnt++; 1681 dev->req.bi_max_vecs++; 1682 dev->vec.bv_page = dev->page; 1683 dev->vec.bv_len = STRIPE_SIZE; 1684 dev->vec.bv_offset = 0; 1685 1686 dev->req.bi_sector = sh->sector; 1687 dev->req.bi_private = sh; 1688 1689 dev->flags = 0; 1690 dev->sector = compute_blocknr(sh, i, previous); 1691} 1692 1693static void error(mddev_t *mddev, mdk_rdev_t *rdev) 1694{ 1695 char b[BDEVNAME_SIZE]; 1696 raid5_conf_t *conf = mddev->private; 1697 pr_debug("raid456: error called\n"); 1698 1699 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1700 unsigned long flags; 1701 spin_lock_irqsave(&conf->device_lock, flags); 1702 mddev->degraded++; 1703 spin_unlock_irqrestore(&conf->device_lock, flags); 1704 /* 1705 * if recovery was running, make sure it aborts. 1706 */ 1707 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1708 } 1709 set_bit(Faulty, &rdev->flags); 1710 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1711 printk(KERN_ALERT 1712 "md/raid:%s: Disk failure on %s, disabling device.\n" 1713 "md/raid:%s: Operation continuing on %d devices.\n", 1714 mdname(mddev), 1715 bdevname(rdev->bdev, b), 1716 mdname(mddev), 1717 conf->raid_disks - mddev->degraded); 1718} 1719 1720/* 1721 * Input: a 'big' sector number, 1722 * Output: index of the data and parity disk, and the sector # in them. 1723 */ 1724static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, 1725 int previous, int *dd_idx, 1726 struct stripe_head *sh) 1727{ 1728 sector_t stripe, stripe2; 1729 sector_t chunk_number; 1730 unsigned int chunk_offset; 1731 int pd_idx, qd_idx; 1732 int ddf_layout = 0; 1733 sector_t new_sector; 1734 int algorithm = previous ? conf->prev_algo 1735 : conf->algorithm; 1736 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1737 : conf->chunk_sectors; 1738 int raid_disks = previous ? conf->previous_raid_disks 1739 : conf->raid_disks; 1740 int data_disks = raid_disks - conf->max_degraded; 1741 1742 /* First compute the information on this sector */ 1743 1744 /* 1745 * Compute the chunk number and the sector offset inside the chunk 1746 */ 1747 chunk_offset = sector_div(r_sector, sectors_per_chunk); 1748 chunk_number = r_sector; 1749 1750 /* 1751 * Compute the stripe number 1752 */ 1753 stripe = chunk_number; 1754 *dd_idx = sector_div(stripe, data_disks); 1755 stripe2 = stripe; 1756 /* 1757 * Select the parity disk based on the user selected algorithm. 1758 */ 1759 pd_idx = qd_idx = -1; 1760 switch(conf->level) { 1761 case 4: 1762 pd_idx = data_disks; 1763 break; 1764 case 5: 1765 switch (algorithm) { 1766 case ALGORITHM_LEFT_ASYMMETRIC: 1767 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1768 if (*dd_idx >= pd_idx) 1769 (*dd_idx)++; 1770 break; 1771 case ALGORITHM_RIGHT_ASYMMETRIC: 1772 pd_idx = sector_div(stripe2, raid_disks); 1773 if (*dd_idx >= pd_idx) 1774 (*dd_idx)++; 1775 break; 1776 case ALGORITHM_LEFT_SYMMETRIC: 1777 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1778 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1779 break; 1780 case ALGORITHM_RIGHT_SYMMETRIC: 1781 pd_idx = sector_div(stripe2, raid_disks); 1782 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1783 break; 1784 case ALGORITHM_PARITY_0: 1785 pd_idx = 0; 1786 (*dd_idx)++; 1787 break; 1788 case ALGORITHM_PARITY_N: 1789 pd_idx = data_disks; 1790 break; 1791 default: 1792 BUG(); 1793 } 1794 break; 1795 case 6: 1796 1797 switch (algorithm) { 1798 case ALGORITHM_LEFT_ASYMMETRIC: 1799 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1800 qd_idx = pd_idx + 1; 1801 if (pd_idx == raid_disks-1) { 1802 (*dd_idx)++; /* Q D D D P */ 1803 qd_idx = 0; 1804 } else if (*dd_idx >= pd_idx) 1805 (*dd_idx) += 2; /* D D P Q D */ 1806 break; 1807 case ALGORITHM_RIGHT_ASYMMETRIC: 1808 pd_idx = sector_div(stripe2, raid_disks); 1809 qd_idx = pd_idx + 1; 1810 if (pd_idx == raid_disks-1) { 1811 (*dd_idx)++; /* Q D D D P */ 1812 qd_idx = 0; 1813 } else if (*dd_idx >= pd_idx) 1814 (*dd_idx) += 2; /* D D P Q D */ 1815 break; 1816 case ALGORITHM_LEFT_SYMMETRIC: 1817 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1818 qd_idx = (pd_idx + 1) % raid_disks; 1819 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1820 break; 1821 case ALGORITHM_RIGHT_SYMMETRIC: 1822 pd_idx = sector_div(stripe2, raid_disks); 1823 qd_idx = (pd_idx + 1) % raid_disks; 1824 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1825 break; 1826 1827 case ALGORITHM_PARITY_0: 1828 pd_idx = 0; 1829 qd_idx = 1; 1830 (*dd_idx) += 2; 1831 break; 1832 case ALGORITHM_PARITY_N: 1833 pd_idx = data_disks; 1834 qd_idx = data_disks + 1; 1835 break; 1836 1837 case ALGORITHM_ROTATING_ZERO_RESTART: 1838 /* Exactly the same as RIGHT_ASYMMETRIC, but or 1839 * of blocks for computing Q is different. 1840 */ 1841 pd_idx = sector_div(stripe2, raid_disks); 1842 qd_idx = pd_idx + 1; 1843 if (pd_idx == raid_disks-1) { 1844 (*dd_idx)++; /* Q D D D P */ 1845 qd_idx = 0; 1846 } else if (*dd_idx >= pd_idx) 1847 (*dd_idx) += 2; /* D D P Q D */ 1848 ddf_layout = 1; 1849 break; 1850 1851 case ALGORITHM_ROTATING_N_RESTART: 1852 /* Same a left_asymmetric, by first stripe is 1853 * D D D P Q rather than 1854 * Q D D D P 1855 */ 1856 stripe2 += 1; 1857 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1858 qd_idx = pd_idx + 1; 1859 if (pd_idx == raid_disks-1) { 1860 (*dd_idx)++; /* Q D D D P */ 1861 qd_idx = 0; 1862 } else if (*dd_idx >= pd_idx) 1863 (*dd_idx) += 2; /* D D P Q D */ 1864 ddf_layout = 1; 1865 break; 1866 1867 case ALGORITHM_ROTATING_N_CONTINUE: 1868 /* Same as left_symmetric but Q is before P */ 1869 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1870 qd_idx = (pd_idx + raid_disks - 1) % raid_disks; 1871 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1872 ddf_layout = 1; 1873 break; 1874 1875 case ALGORITHM_LEFT_ASYMMETRIC_6: 1876 /* RAID5 left_asymmetric, with Q on last device */ 1877 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1878 if (*dd_idx >= pd_idx) 1879 (*dd_idx)++; 1880 qd_idx = raid_disks - 1; 1881 break; 1882 1883 case ALGORITHM_RIGHT_ASYMMETRIC_6: 1884 pd_idx = sector_div(stripe2, raid_disks-1); 1885 if (*dd_idx >= pd_idx) 1886 (*dd_idx)++; 1887 qd_idx = raid_disks - 1; 1888 break; 1889 1890 case ALGORITHM_LEFT_SYMMETRIC_6: 1891 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1892 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1893 qd_idx = raid_disks - 1; 1894 break; 1895 1896 case ALGORITHM_RIGHT_SYMMETRIC_6: 1897 pd_idx = sector_div(stripe2, raid_disks-1); 1898 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1899 qd_idx = raid_disks - 1; 1900 break; 1901 1902 case ALGORITHM_PARITY_0_6: 1903 pd_idx = 0; 1904 (*dd_idx)++; 1905 qd_idx = raid_disks - 1; 1906 break; 1907 1908 default: 1909 BUG(); 1910 } 1911 break; 1912 } 1913 1914 if (sh) { 1915 sh->pd_idx = pd_idx; 1916 sh->qd_idx = qd_idx; 1917 sh->ddf_layout = ddf_layout; 1918 } 1919 /* 1920 * Finally, compute the new sector number 1921 */ 1922 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; 1923 return new_sector; 1924} 1925 1926 1927static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) 1928{ 1929 raid5_conf_t *conf = sh->raid_conf; 1930 int raid_disks = sh->disks; 1931 int data_disks = raid_disks - conf->max_degraded; 1932 sector_t new_sector = sh->sector, check; 1933 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1934 : conf->chunk_sectors; 1935 int algorithm = previous ? conf->prev_algo 1936 : conf->algorithm; 1937 sector_t stripe; 1938 int chunk_offset; 1939 sector_t chunk_number; 1940 int dummy1, dd_idx = i; 1941 sector_t r_sector; 1942 struct stripe_head sh2; 1943 1944 1945 chunk_offset = sector_div(new_sector, sectors_per_chunk); 1946 stripe = new_sector; 1947 1948 if (i == sh->pd_idx) 1949 return 0; 1950 switch(conf->level) { 1951 case 4: break; 1952 case 5: 1953 switch (algorithm) { 1954 case ALGORITHM_LEFT_ASYMMETRIC: 1955 case ALGORITHM_RIGHT_ASYMMETRIC: 1956 if (i > sh->pd_idx) 1957 i--; 1958 break; 1959 case ALGORITHM_LEFT_SYMMETRIC: 1960 case ALGORITHM_RIGHT_SYMMETRIC: 1961 if (i < sh->pd_idx) 1962 i += raid_disks; 1963 i -= (sh->pd_idx + 1); 1964 break; 1965 case ALGORITHM_PARITY_0: 1966 i -= 1; 1967 break; 1968 case ALGORITHM_PARITY_N: 1969 break; 1970 default: 1971 BUG(); 1972 } 1973 break; 1974 case 6: 1975 if (i == sh->qd_idx) 1976 return 0; /* It is the Q disk */ 1977 switch (algorithm) { 1978 case ALGORITHM_LEFT_ASYMMETRIC: 1979 case ALGORITHM_RIGHT_ASYMMETRIC: 1980 case ALGORITHM_ROTATING_ZERO_RESTART: 1981 case ALGORITHM_ROTATING_N_RESTART: 1982 if (sh->pd_idx == raid_disks-1) 1983 i--; /* Q D D D P */ 1984 else if (i > sh->pd_idx) 1985 i -= 2; /* D D P Q D */ 1986 break; 1987 case ALGORITHM_LEFT_SYMMETRIC: 1988 case ALGORITHM_RIGHT_SYMMETRIC: 1989 if (sh->pd_idx == raid_disks-1) 1990 i--; /* Q D D D P */ 1991 else { 1992 /* D D P Q D */ 1993 if (i < sh->pd_idx) 1994 i += raid_disks; 1995 i -= (sh->pd_idx + 2); 1996 } 1997 break; 1998 case ALGORITHM_PARITY_0: 1999 i -= 2; 2000 break; 2001 case ALGORITHM_PARITY_N: 2002 break; 2003 case ALGORITHM_ROTATING_N_CONTINUE: 2004 /* Like left_symmetric, but P is before Q */ 2005 if (sh->pd_idx == 0) 2006 i--; /* P D D D Q */ 2007 else { 2008 /* D D Q P D */ 2009 if (i < sh->pd_idx) 2010 i += raid_disks; 2011 i -= (sh->pd_idx + 1); 2012 } 2013 break; 2014 case ALGORITHM_LEFT_ASYMMETRIC_6: 2015 case ALGORITHM_RIGHT_ASYMMETRIC_6: 2016 if (i > sh->pd_idx) 2017 i--; 2018 break; 2019 case ALGORITHM_LEFT_SYMMETRIC_6: 2020 case ALGORITHM_RIGHT_SYMMETRIC_6: 2021 if (i < sh->pd_idx) 2022 i += data_disks + 1; 2023 i -= (sh->pd_idx + 1); 2024 break; 2025 case ALGORITHM_PARITY_0_6: 2026 i -= 1; 2027 break; 2028 default: 2029 BUG(); 2030 } 2031 break; 2032 } 2033 2034 chunk_number = stripe * data_disks + i; 2035 r_sector = chunk_number * sectors_per_chunk + chunk_offset; 2036 2037 check = raid5_compute_sector(conf, r_sector, 2038 previous, &dummy1, &sh2); 2039 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx 2040 || sh2.qd_idx != sh->qd_idx) { 2041 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n", 2042 mdname(conf->mddev)); 2043 return 0; 2044 } 2045 return r_sector; 2046} 2047 2048 2049static void 2050schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, 2051 int rcw, int expand) 2052{ 2053 int i, pd_idx = sh->pd_idx, disks = sh->disks; 2054 raid5_conf_t *conf = sh->raid_conf; 2055 int level = conf->level; 2056 2057 if (rcw) { 2058 /* if we are not expanding this is a proper write request, and 2059 * there will be bios with new data to be drained into the 2060 * stripe cache 2061 */ 2062 if (!expand) { 2063 sh->reconstruct_state = reconstruct_state_drain_run; 2064 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2065 } else 2066 sh->reconstruct_state = reconstruct_state_run; 2067 2068 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2069 2070 for (i = disks; i--; ) { 2071 struct r5dev *dev = &sh->dev[i]; 2072 2073 if (dev->towrite) { 2074 set_bit(R5_LOCKED, &dev->flags); 2075 set_bit(R5_Wantdrain, &dev->flags); 2076 if (!expand) 2077 clear_bit(R5_UPTODATE, &dev->flags); 2078 s->locked++; 2079 } 2080 } 2081 if (s->locked + conf->max_degraded == disks) 2082 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) 2083 atomic_inc(&conf->pending_full_writes); 2084 } else { 2085 BUG_ON(level == 6); 2086 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || 2087 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); 2088 2089 sh->reconstruct_state = reconstruct_state_prexor_drain_run; 2090 set_bit(STRIPE_OP_PREXOR, &s->ops_request); 2091 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2092 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2093 2094 for (i = disks; i--; ) { 2095 struct r5dev *dev = &sh->dev[i]; 2096 if (i == pd_idx) 2097 continue; 2098 2099 if (dev->towrite && 2100 (test_bit(R5_UPTODATE, &dev->flags) || 2101 test_bit(R5_Wantcompute, &dev->flags))) { 2102 set_bit(R5_Wantdrain, &dev->flags); 2103 set_bit(R5_LOCKED, &dev->flags); 2104 clear_bit(R5_UPTODATE, &dev->flags); 2105 s->locked++; 2106 } 2107 } 2108 } 2109 2110 /* keep the parity disk(s) locked while asynchronous operations 2111 * are in flight 2112 */ 2113 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 2114 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2115 s->locked++; 2116 2117 if (level == 6) { 2118 int qd_idx = sh->qd_idx; 2119 struct r5dev *dev = &sh->dev[qd_idx]; 2120 2121 set_bit(R5_LOCKED, &dev->flags); 2122 clear_bit(R5_UPTODATE, &dev->flags); 2123 s->locked++; 2124 } 2125 2126 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", 2127 __func__, (unsigned long long)sh->sector, 2128 s->locked, s->ops_request); 2129} 2130 2131/* 2132 * Each stripe/dev can have one or more bion attached. 2133 * toread/towrite point to the first in a chain. 2134 * The bi_next chain must be in order. 2135 */ 2136static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 2137{ 2138 struct bio **bip; 2139 raid5_conf_t *conf = sh->raid_conf; 2140 int firstwrite=0; 2141 2142 pr_debug("adding bi b#%llu to stripe s#%llu\n", 2143 (unsigned long long)bi->bi_sector, 2144 (unsigned long long)sh->sector); 2145 2146 2147 spin_lock_irq(&conf->device_lock); 2148 if (forwrite) { 2149 bip = &sh->dev[dd_idx].towrite; 2150 if (*bip == NULL && sh->dev[dd_idx].written == NULL) 2151 firstwrite = 1; 2152 } else 2153 bip = &sh->dev[dd_idx].toread; 2154 while (*bip && (*bip)->bi_sector < bi->bi_sector) { 2155 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) 2156 goto overlap; 2157 bip = & (*bip)->bi_next; 2158 } 2159 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) 2160 goto overlap; 2161 2162 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); 2163 if (*bip) 2164 bi->bi_next = *bip; 2165 *bip = bi; 2166 bi->bi_phys_segments++; 2167 2168 if (forwrite) { 2169 /* check if page is covered */ 2170 sector_t sector = sh->dev[dd_idx].sector; 2171 for (bi=sh->dev[dd_idx].towrite; 2172 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && 2173 bi && bi->bi_sector <= sector; 2174 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { 2175 if (bi->bi_sector + (bi->bi_size>>9) >= sector) 2176 sector = bi->bi_sector + (bi->bi_size>>9); 2177 } 2178 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) 2179 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); 2180 } 2181 spin_unlock_irq(&conf->device_lock); 2182 2183 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", 2184 (unsigned long long)(*bip)->bi_sector, 2185 (unsigned long long)sh->sector, dd_idx); 2186 2187 if (conf->mddev->bitmap && firstwrite) { 2188 bitmap_startwrite(conf->mddev->bitmap, sh->sector, 2189 STRIPE_SECTORS, 0); 2190 sh->bm_seq = conf->seq_flush+1; 2191 set_bit(STRIPE_BIT_DELAY, &sh->state); 2192 } 2193 return 1; 2194 2195 overlap: 2196 set_bit(R5_Overlap, &sh->dev[dd_idx].flags); 2197 spin_unlock_irq(&conf->device_lock); 2198 return 0; 2199} 2200 2201static void end_reshape(raid5_conf_t *conf); 2202 2203static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, 2204 struct stripe_head *sh) 2205{ 2206 int sectors_per_chunk = 2207 previous ? conf->prev_chunk_sectors : conf->chunk_sectors; 2208 int dd_idx; 2209 int chunk_offset = sector_div(stripe, sectors_per_chunk); 2210 int disks = previous ? conf->previous_raid_disks : conf->raid_disks; 2211 2212 raid5_compute_sector(conf, 2213 stripe * (disks - conf->max_degraded) 2214 *sectors_per_chunk + chunk_offset, 2215 previous, 2216 &dd_idx, sh); 2217} 2218 2219static void 2220handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, 2221 struct stripe_head_state *s, int disks, 2222 struct bio **return_bi) 2223{ 2224 int i; 2225 for (i = disks; i--; ) { 2226 struct bio *bi; 2227 int bitmap_end = 0; 2228 2229 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 2230 mdk_rdev_t *rdev; 2231 rcu_read_lock(); 2232 rdev = rcu_dereference(conf->disks[i].rdev); 2233 if (rdev && test_bit(In_sync, &rdev->flags)) 2234 /* multiple read failures in one stripe */ 2235 md_error(conf->mddev, rdev); 2236 rcu_read_unlock(); 2237 } 2238 spin_lock_irq(&conf->device_lock); 2239 /* fail all writes first */ 2240 bi = sh->dev[i].towrite; 2241 sh->dev[i].towrite = NULL; 2242 if (bi) { 2243 s->to_write--; 2244 bitmap_end = 1; 2245 } 2246 2247 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2248 wake_up(&conf->wait_for_overlap); 2249 2250 while (bi && bi->bi_sector < 2251 sh->dev[i].sector + STRIPE_SECTORS) { 2252 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2253 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2254 if (!raid5_dec_bi_phys_segments(bi)) { 2255 md_write_end(conf->mddev); 2256 bi->bi_next = *return_bi; 2257 *return_bi = bi; 2258 } 2259 bi = nextbi; 2260 } 2261 /* and fail all 'written' */ 2262 bi = sh->dev[i].written; 2263 sh->dev[i].written = NULL; 2264 if (bi) bitmap_end = 1; 2265 while (bi && bi->bi_sector < 2266 sh->dev[i].sector + STRIPE_SECTORS) { 2267 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 2268 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2269 if (!raid5_dec_bi_phys_segments(bi)) { 2270 md_write_end(conf->mddev); 2271 bi->bi_next = *return_bi; 2272 *return_bi = bi; 2273 } 2274 bi = bi2; 2275 } 2276 2277 /* fail any reads if this device is non-operational and 2278 * the data has not reached the cache yet. 2279 */ 2280 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && 2281 (!test_bit(R5_Insync, &sh->dev[i].flags) || 2282 test_bit(R5_ReadError, &sh->dev[i].flags))) { 2283 bi = sh->dev[i].toread; 2284 sh->dev[i].toread = NULL; 2285 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2286 wake_up(&conf->wait_for_overlap); 2287 if (bi) s->to_read--; 2288 while (bi && bi->bi_sector < 2289 sh->dev[i].sector + STRIPE_SECTORS) { 2290 struct bio *nextbi = 2291 r5_next_bio(bi, sh->dev[i].sector); 2292 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2293 if (!raid5_dec_bi_phys_segments(bi)) { 2294 bi->bi_next = *return_bi; 2295 *return_bi = bi; 2296 } 2297 bi = nextbi; 2298 } 2299 } 2300 spin_unlock_irq(&conf->device_lock); 2301 if (bitmap_end) 2302 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2303 STRIPE_SECTORS, 0, 0); 2304 } 2305 2306 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2307 if (atomic_dec_and_test(&conf->pending_full_writes)) 2308 md_wakeup_thread(conf->mddev->thread); 2309} 2310 2311/* fetch_block - checks the given member device to see if its data needs 2312 * to be read or computed to satisfy a request. 2313 * 2314 * Returns 1 when no more member devices need to be checked, otherwise returns 2315 * 0 to tell the loop in handle_stripe_fill to continue 2316 */ 2317static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, 2318 int disk_idx, int disks) 2319{ 2320 struct r5dev *dev = &sh->dev[disk_idx]; 2321 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], 2322 &sh->dev[s->failed_num[1]] }; 2323 2324 /* is the data in this block needed, and can we get it? */ 2325 if (!test_bit(R5_LOCKED, &dev->flags) && 2326 !test_bit(R5_UPTODATE, &dev->flags) && 2327 (dev->toread || 2328 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 2329 s->syncing || s->expanding || 2330 (s->failed >= 1 && fdev[0]->toread) || 2331 (s->failed >= 2 && fdev[1]->toread) || 2332 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && 2333 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || 2334 (sh->raid_conf->level == 6 && s->failed && s->to_write))) { 2335 /* we would like to get this block, possibly by computing it, 2336 * otherwise read it if the backing disk is insync 2337 */ 2338 BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); 2339 BUG_ON(test_bit(R5_Wantread, &dev->flags)); 2340 if ((s->uptodate == disks - 1) && 2341 (s->failed && (disk_idx == s->failed_num[0] || 2342 disk_idx == s->failed_num[1]))) { 2343 /* have disk failed, and we're requested to fetch it; 2344 * do compute it 2345 */ 2346 pr_debug("Computing stripe %llu block %d\n", 2347 (unsigned long long)sh->sector, disk_idx); 2348 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2349 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2350 set_bit(R5_Wantcompute, &dev->flags); 2351 sh->ops.target = disk_idx; 2352 sh->ops.target2 = -1; /* no 2nd target */ 2353 s->req_compute = 1; 2354 /* Careful: from this point on 'uptodate' is in the eye 2355 * of raid_run_ops which services 'compute' operations 2356 * before writes. R5_Wantcompute flags a block that will 2357 * be R5_UPTODATE by the time it is needed for a 2358 * subsequent operation. 2359 */ 2360 s->uptodate++; 2361 return 1; 2362 } else if (s->uptodate == disks-2 && s->failed >= 2) { 2363 /* Computing 2-failure is *very* expensive; only 2364 * do it if failed >= 2 2365 */ 2366 int other; 2367 for (other = disks; other--; ) { 2368 if (other == disk_idx) 2369 continue; 2370 if (!test_bit(R5_UPTODATE, 2371 &sh->dev[other].flags)) 2372 break; 2373 } 2374 BUG_ON(other < 0); 2375 pr_debug("Computing stripe %llu blocks %d,%d\n", 2376 (unsigned long long)sh->sector, 2377 disk_idx, other); 2378 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2379 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2380 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); 2381 set_bit(R5_Wantcompute, &sh->dev[other].flags); 2382 sh->ops.target = disk_idx; 2383 sh->ops.target2 = other; 2384 s->uptodate += 2; 2385 s->req_compute = 1; 2386 return 1; 2387 } else if (test_bit(R5_Insync, &dev->flags)) { 2388 set_bit(R5_LOCKED, &dev->flags); 2389 set_bit(R5_Wantread, &dev->flags); 2390 s->locked++; 2391 pr_debug("Reading block %d (sync=%d)\n", 2392 disk_idx, s->syncing); 2393 } 2394 } 2395 2396 return 0; 2397} 2398 2399/** 2400 * handle_stripe_fill - read or compute data to satisfy pending requests. 2401 */ 2402static void handle_stripe_fill(struct stripe_head *sh, 2403 struct stripe_head_state *s, 2404 int disks) 2405{ 2406 int i; 2407 2408 /* look for blocks to read/compute, skip this if a compute 2409 * is already in flight, or if the stripe contents are in the 2410 * midst of changing due to a write 2411 */ 2412 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && 2413 !sh->reconstruct_state) 2414 for (i = disks; i--; ) 2415 if (fetch_block(sh, s, i, disks)) 2416 break; 2417 set_bit(STRIPE_HANDLE, &sh->state); 2418} 2419 2420 2421/* handle_stripe_clean_event 2422 * any written block on an uptodate or failed drive can be returned. 2423 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 2424 * never LOCKED, so we don't need to test 'failed' directly. 2425 */ 2426static void handle_stripe_clean_event(raid5_conf_t *conf, 2427 struct stripe_head *sh, int disks, struct bio **return_bi) 2428{ 2429 int i; 2430 struct r5dev *dev; 2431 2432 for (i = disks; i--; ) 2433 if (sh->dev[i].written) { 2434 dev = &sh->dev[i]; 2435 if (!test_bit(R5_LOCKED, &dev->flags) && 2436 test_bit(R5_UPTODATE, &dev->flags)) { 2437 /* We can return any write requests */ 2438 struct bio *wbi, *wbi2; 2439 int bitmap_end = 0; 2440 pr_debug("Return write for disc %d\n", i); 2441 spin_lock_irq(&conf->device_lock); 2442 wbi = dev->written; 2443 dev->written = NULL; 2444 while (wbi && wbi->bi_sector < 2445 dev->sector + STRIPE_SECTORS) { 2446 wbi2 = r5_next_bio(wbi, dev->sector); 2447 if (!raid5_dec_bi_phys_segments(wbi)) { 2448 md_write_end(conf->mddev); 2449 wbi->bi_next = *return_bi; 2450 *return_bi = wbi; 2451 } 2452 wbi = wbi2; 2453 } 2454 if (dev->towrite == NULL) 2455 bitmap_end = 1; 2456 spin_unlock_irq(&conf->device_lock); 2457 if (bitmap_end) 2458 bitmap_endwrite(conf->mddev->bitmap, 2459 sh->sector, 2460 STRIPE_SECTORS, 2461 !test_bit(STRIPE_DEGRADED, &sh->state), 2462 0); 2463 } 2464 } 2465 2466 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2467 if (atomic_dec_and_test(&conf->pending_full_writes)) 2468 md_wakeup_thread(conf->mddev->thread); 2469} 2470 2471static void handle_stripe_dirtying(raid5_conf_t *conf, 2472 struct stripe_head *sh, 2473 struct stripe_head_state *s, 2474 int disks) 2475{ 2476 int rmw = 0, rcw = 0, i; 2477 if (conf->max_degraded == 2) { 2478 /* RAID6 requires 'rcw' in current implementation 2479 * Calculate the real rcw later - for now fake it 2480 * look like rcw is cheaper 2481 */ 2482 rcw = 1; rmw = 2; 2483 } else for (i = disks; i--; ) { 2484 /* would I have to read this buffer for read_modify_write */ 2485 struct r5dev *dev = &sh->dev[i]; 2486 if ((dev->towrite || i == sh->pd_idx) && 2487 !test_bit(R5_LOCKED, &dev->flags) && 2488 !(test_bit(R5_UPTODATE, &dev->flags) || 2489 test_bit(R5_Wantcompute, &dev->flags))) { 2490 if (test_bit(R5_Insync, &dev->flags)) 2491 rmw++; 2492 else 2493 rmw += 2*disks; /* cannot read it */ 2494 } 2495 /* Would I have to read this buffer for reconstruct_write */ 2496 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 2497 !test_bit(R5_LOCKED, &dev->flags) && 2498 !(test_bit(R5_UPTODATE, &dev->flags) || 2499 test_bit(R5_Wantcompute, &dev->flags))) { 2500 if (test_bit(R5_Insync, &dev->flags)) rcw++; 2501 else 2502 rcw += 2*disks; 2503 } 2504 } 2505 pr_debug("for sector %llu, rmw=%d rcw=%d\n", 2506 (unsigned long long)sh->sector, rmw, rcw); 2507 set_bit(STRIPE_HANDLE, &sh->state); 2508 if (rmw < rcw && rmw > 0) 2509 /* prefer read-modify-write, but need to get some data */ 2510 for (i = disks; i--; ) { 2511 struct r5dev *dev = &sh->dev[i]; 2512 if ((dev->towrite || i == sh->pd_idx) && 2513 !test_bit(R5_LOCKED, &dev->flags) && 2514 !(test_bit(R5_UPTODATE, &dev->flags) || 2515 test_bit(R5_Wantcompute, &dev->flags)) && 2516 test_bit(R5_Insync, &dev->flags)) { 2517 if ( 2518 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2519 pr_debug("Read_old block " 2520 "%d for r-m-w\n", i); 2521 set_bit(R5_LOCKED, &dev->flags); 2522 set_bit(R5_Wantread, &dev->flags); 2523 s->locked++; 2524 } else { 2525 set_bit(STRIPE_DELAYED, &sh->state); 2526 set_bit(STRIPE_HANDLE, &sh->state); 2527 } 2528 } 2529 } 2530 if (rcw <= rmw && rcw > 0) { 2531 /* want reconstruct write, but need to get some data */ 2532 rcw = 0; 2533 for (i = disks; i--; ) { 2534 struct r5dev *dev = &sh->dev[i]; 2535 if (!test_bit(R5_OVERWRITE, &dev->flags) && 2536 i != sh->pd_idx && i != sh->qd_idx && 2537 !test_bit(R5_LOCKED, &dev->flags) && 2538 !(test_bit(R5_UPTODATE, &dev->flags) || 2539 test_bit(R5_Wantcompute, &dev->flags))) { 2540 rcw++; 2541 if (!test_bit(R5_Insync, &dev->flags)) 2542 continue; /* it's a failed drive */ 2543 if ( 2544 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2545 pr_debug("Read_old block " 2546 "%d for Reconstruct\n", i); 2547 set_bit(R5_LOCKED, &dev->flags); 2548 set_bit(R5_Wantread, &dev->flags); 2549 s->locked++; 2550 } else { 2551 set_bit(STRIPE_DELAYED, &sh->state); 2552 set_bit(STRIPE_HANDLE, &sh->state); 2553 } 2554 } 2555 } 2556 } 2557 /* now if nothing is locked, and if we have enough data, 2558 * we can start a write request 2559 */ 2560 /* since handle_stripe can be called at any time we need to handle the 2561 * case where a compute block operation has been submitted and then a 2562 * subsequent call wants to start a write request. raid_run_ops only 2563 * handles the case where compute block and reconstruct are requested 2564 * simultaneously. If this is not the case then new writes need to be 2565 * held off until the compute completes. 2566 */ 2567 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && 2568 (s->locked == 0 && (rcw == 0 || rmw == 0) && 2569 !test_bit(STRIPE_BIT_DELAY, &sh->state))) 2570 schedule_reconstruction(sh, s, rcw == 0, 0); 2571} 2572 2573static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, 2574 struct stripe_head_state *s, int disks) 2575{ 2576 struct r5dev *dev = NULL; 2577 2578 set_bit(STRIPE_HANDLE, &sh->state); 2579 2580 switch (sh->check_state) { 2581 case check_state_idle: 2582 /* start a new check operation if there are no failures */ 2583 if (s->failed == 0) { 2584 BUG_ON(s->uptodate != disks); 2585 sh->check_state = check_state_run; 2586 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2587 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); 2588 s->uptodate--; 2589 break; 2590 } 2591 dev = &sh->dev[s->failed_num[0]]; 2592 /* fall through */ 2593 case check_state_compute_result: 2594 sh->check_state = check_state_idle; 2595 if (!dev) 2596 dev = &sh->dev[sh->pd_idx]; 2597 2598 /* check that a write has not made the stripe insync */ 2599 if (test_bit(STRIPE_INSYNC, &sh->state)) 2600 break; 2601 2602 /* either failed parity check, or recovery is happening */ 2603 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); 2604 BUG_ON(s->uptodate != disks); 2605 2606 set_bit(R5_LOCKED, &dev->flags); 2607 s->locked++; 2608 set_bit(R5_Wantwrite, &dev->flags); 2609 2610 clear_bit(STRIPE_DEGRADED, &sh->state); 2611 set_bit(STRIPE_INSYNC, &sh->state); 2612 break; 2613 case check_state_run: 2614 break; /* we will be called again upon completion */ 2615 case check_state_check_result: 2616 sh->check_state = check_state_idle; 2617 2618 /* if a failure occurred during the check operation, leave 2619 * STRIPE_INSYNC not set and let the stripe be handled again 2620 */ 2621 if (s->failed) 2622 break; 2623 2624 /* handle a successful check operation, if parity is correct 2625 * we are done. Otherwise update the mismatch count and repair 2626 * parity if !MD_RECOVERY_CHECK 2627 */ 2628 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0) 2629 /* parity is correct (on disc, 2630 * not in buffer any more) 2631 */ 2632 set_bit(STRIPE_INSYNC, &sh->state); 2633 else { 2634 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2635 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2636 /* don't try to repair!! */ 2637 set_bit(STRIPE_INSYNC, &sh->state); 2638 else { 2639 sh->check_state = check_state_compute_run; 2640 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2641 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2642 set_bit(R5_Wantcompute, 2643 &sh->dev[sh->pd_idx].flags); 2644 sh->ops.target = sh->pd_idx; 2645 sh->ops.target2 = -1; 2646 s->uptodate++; 2647 } 2648 } 2649 break; 2650 case check_state_compute_run: 2651 break; 2652 default: 2653 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2654 __func__, sh->check_state, 2655 (unsigned long long) sh->sector); 2656 BUG(); 2657 } 2658} 2659 2660 2661static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh, 2662 struct stripe_head_state *s, 2663 int disks) 2664{ 2665 int pd_idx = sh->pd_idx; 2666 int qd_idx = sh->qd_idx; 2667 struct r5dev *dev; 2668 2669 set_bit(STRIPE_HANDLE, &sh->state); 2670 2671 BUG_ON(s->failed > 2); 2672 2673 /* Want to check and possibly repair P and Q. 2674 * However there could be one 'failed' device, in which 2675 * case we can only check one of them, possibly using the 2676 * other to generate missing data 2677 */ 2678 2679 switch (sh->check_state) { 2680 case check_state_idle: 2681 /* start a new check operation if there are < 2 failures */ 2682 if (s->failed == s->q_failed) { 2683 /* The only possible failed device holds Q, so it 2684 * makes sense to check P (If anything else were failed, 2685 * we would have used P to recreate it). 2686 */ 2687 sh->check_state = check_state_run; 2688 } 2689 if (!s->q_failed && s->failed < 2) { 2690 /* Q is not failed, and we didn't use it to generate 2691 * anything, so it makes sense to check it 2692 */ 2693 if (sh->check_state == check_state_run) 2694 sh->check_state = check_state_run_pq; 2695 else 2696 sh->check_state = check_state_run_q; 2697 } 2698 2699 /* discard potentially stale zero_sum_result */ 2700 sh->ops.zero_sum_result = 0; 2701 2702 if (sh->check_state == check_state_run) { 2703 /* async_xor_zero_sum destroys the contents of P */ 2704 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2705 s->uptodate--; 2706 } 2707 if (sh->check_state >= check_state_run && 2708 sh->check_state <= check_state_run_pq) { 2709 /* async_syndrome_zero_sum preserves P and Q, so 2710 * no need to mark them !uptodate here 2711 */ 2712 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2713 break; 2714 } 2715 2716 /* we have 2-disk failure */ 2717 BUG_ON(s->failed != 2); 2718 /* fall through */ 2719 case check_state_compute_result: 2720 sh->check_state = check_state_idle; 2721 2722 /* check that a write has not made the stripe insync */ 2723 if (test_bit(STRIPE_INSYNC, &sh->state)) 2724 break; 2725 2726 /* now write out any block on a failed drive, 2727 * or P or Q if they were recomputed 2728 */ 2729 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ 2730 if (s->failed == 2) { 2731 dev = &sh->dev[s->failed_num[1]]; 2732 s->locked++; 2733 set_bit(R5_LOCKED, &dev->flags); 2734 set_bit(R5_Wantwrite, &dev->flags); 2735 } 2736 if (s->failed >= 1) { 2737 dev = &sh->dev[s->failed_num[0]]; 2738 s->locked++; 2739 set_bit(R5_LOCKED, &dev->flags); 2740 set_bit(R5_Wantwrite, &dev->flags); 2741 } 2742 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2743 dev = &sh->dev[pd_idx]; 2744 s->locked++; 2745 set_bit(R5_LOCKED, &dev->flags); 2746 set_bit(R5_Wantwrite, &dev->flags); 2747 } 2748 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2749 dev = &sh->dev[qd_idx]; 2750 s->locked++; 2751 set_bit(R5_LOCKED, &dev->flags); 2752 set_bit(R5_Wantwrite, &dev->flags); 2753 } 2754 clear_bit(STRIPE_DEGRADED, &sh->state); 2755 2756 set_bit(STRIPE_INSYNC, &sh->state); 2757 break; 2758 case check_state_run: 2759 case check_state_run_q: 2760 case check_state_run_pq: 2761 break; /* we will be called again upon completion */ 2762 case check_state_check_result: 2763 sh->check_state = check_state_idle; 2764 2765 /* handle a successful check operation, if parity is correct 2766 * we are done. Otherwise update the mismatch count and repair 2767 * parity if !MD_RECOVERY_CHECK 2768 */ 2769 if (sh->ops.zero_sum_result == 0) { 2770 /* both parities are correct */ 2771 if (!s->failed) 2772 set_bit(STRIPE_INSYNC, &sh->state); 2773 else { 2774 /* in contrast to the raid5 case we can validate 2775 * parity, but still have a failure to write 2776 * back 2777 */ 2778 sh->check_state = check_state_compute_result; 2779 /* Returning at this point means that we may go 2780 * off and bring p and/or q uptodate again so 2781 * we make sure to check zero_sum_result again 2782 * to verify if p or q need writeback 2783 */ 2784 } 2785 } else { 2786 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2787 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2788 /* don't try to repair!! */ 2789 set_bit(STRIPE_INSYNC, &sh->state); 2790 else { 2791 int *target = &sh->ops.target; 2792 2793 sh->ops.target = -1; 2794 sh->ops.target2 = -1; 2795 sh->check_state = check_state_compute_run; 2796 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2797 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2798 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2799 set_bit(R5_Wantcompute, 2800 &sh->dev[pd_idx].flags); 2801 *target = pd_idx; 2802 target = &sh->ops.target2; 2803 s->uptodate++; 2804 } 2805 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2806 set_bit(R5_Wantcompute, 2807 &sh->dev[qd_idx].flags); 2808 *target = qd_idx; 2809 s->uptodate++; 2810 } 2811 } 2812 } 2813 break; 2814 case check_state_compute_run: 2815 break; 2816 default: 2817 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2818 __func__, sh->check_state, 2819 (unsigned long long) sh->sector); 2820 BUG(); 2821 } 2822} 2823 2824static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh) 2825{ 2826 int i; 2827 2828 /* We have read all the blocks in this stripe and now we need to 2829 * copy some of them into a target stripe for expand. 2830 */ 2831 struct dma_async_tx_descriptor *tx = NULL; 2832 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2833 for (i = 0; i < sh->disks; i++) 2834 if (i != sh->pd_idx && i != sh->qd_idx) { 2835 int dd_idx, j; 2836 struct stripe_head *sh2; 2837 struct async_submit_ctl submit; 2838 2839 sector_t bn = compute_blocknr(sh, i, 1); 2840 sector_t s = raid5_compute_sector(conf, bn, 0, 2841 &dd_idx, NULL); 2842 sh2 = get_active_stripe(conf, s, 0, 1, 1); 2843 if (sh2 == NULL) 2844 /* so far only the early blocks of this stripe 2845 * have been requested. When later blocks 2846 * get requested, we will try again 2847 */ 2848 continue; 2849 if (!test_bit(STRIPE_EXPANDING, &sh2->state) || 2850 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { 2851 /* must have already done this block */ 2852 release_stripe(sh2); 2853 continue; 2854 } 2855 2856 /* place all the copies on one channel */ 2857 init_async_submit(&submit, 0, tx, NULL, NULL, NULL); 2858 tx = async_memcpy(sh2->dev[dd_idx].page, 2859 sh->dev[i].page, 0, 0, STRIPE_SIZE, 2860 &submit); 2861 2862 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); 2863 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); 2864 for (j = 0; j < conf->raid_disks; j++) 2865 if (j != sh2->pd_idx && 2866 j != sh2->qd_idx && 2867 !test_bit(R5_Expanded, &sh2->dev[j].flags)) 2868 break; 2869 if (j == conf->raid_disks) { 2870 set_bit(STRIPE_EXPAND_READY, &sh2->state); 2871 set_bit(STRIPE_HANDLE, &sh2->state); 2872 } 2873 release_stripe(sh2); 2874 2875 } 2876 /* done submitting copies, wait for them to complete */ 2877 if (tx) { 2878 async_tx_ack(tx); 2879 dma_wait_for_async_tx(tx); 2880 } 2881} 2882 2883 2884/* 2885 * handle_stripe - do things to a stripe. 2886 * 2887 * We lock the stripe and then examine the state of various bits 2888 * to see what needs to be done. 2889 * Possible results: 2890 * return some read request which now have data 2891 * return some write requests which are safely on disc 2892 * schedule a read on some buffers 2893 * schedule a write of some buffers 2894 * return confirmation of parity correctness 2895 * 2896 * buffers are taken off read_list or write_list, and bh_cache buffers 2897 * get BH_Lock set before the stripe lock is released. 2898 * 2899 */ 2900 2901static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) 2902{ 2903 raid5_conf_t *conf = sh->raid_conf; 2904 int disks = sh->disks; 2905 struct r5dev *dev; 2906 int i; 2907 2908 memset(s, 0, sizeof(*s)); 2909 2910 s->syncing = test_bit(STRIPE_SYNCING, &sh->state); 2911 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2912 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); 2913 s->failed_num[0] = -1; 2914 s->failed_num[1] = -1; 2915 2916 /* Now to look around and see what can be done */ 2917 rcu_read_lock(); 2918 spin_lock_irq(&conf->device_lock); 2919 for (i=disks; i--; ) { 2920 mdk_rdev_t *rdev; 2921 2922 dev = &sh->dev[i]; 2923 2924 pr_debug("check %d: state 0x%lx read %p write %p written %p\n", 2925 i, dev->flags, dev->toread, dev->towrite, dev->written); 2926 /* maybe we can reply to a read 2927 * 2928 * new wantfill requests are only permitted while 2929 * ops_complete_biofill is guaranteed to be inactive 2930 */ 2931 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && 2932 !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) 2933 set_bit(R5_Wantfill, &dev->flags); 2934 2935 /* now count some things */ 2936 if (test_bit(R5_LOCKED, &dev->flags)) 2937 s->locked++; 2938 if (test_bit(R5_UPTODATE, &dev->flags)) 2939 s->uptodate++; 2940 if (test_bit(R5_Wantcompute, &dev->flags)) { 2941 s->compute++; 2942 BUG_ON(s->compute > 2); 2943 } 2944 2945 if (test_bit(R5_Wantfill, &dev->flags)) 2946 s->to_fill++; 2947 else if (dev->toread) 2948 s->to_read++; 2949 if (dev->towrite) { 2950 s->to_write++; 2951 if (!test_bit(R5_OVERWRITE, &dev->flags)) 2952 s->non_overwrite++; 2953 } 2954 if (dev->written) 2955 s->written++; 2956 rdev = rcu_dereference(conf->disks[i].rdev); 2957 if (s->blocked_rdev == NULL && 2958 rdev && unlikely(test_bit(Blocked, &rdev->flags))) { 2959 s->blocked_rdev = rdev; 2960 atomic_inc(&rdev->nr_pending); 2961 } 2962 clear_bit(R5_Insync, &dev->flags); 2963 if (!rdev) 2964 /* Not in-sync */; 2965 else if (test_bit(In_sync, &rdev->flags)) 2966 set_bit(R5_Insync, &dev->flags); 2967 else { 2968 /* in sync if before recovery_offset */ 2969 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) 2970 set_bit(R5_Insync, &dev->flags); 2971 } 2972 if (!test_bit(R5_Insync, &dev->flags)) { 2973 /* The ReadError flag will just be confusing now */ 2974 clear_bit(R5_ReadError, &dev->flags); 2975 clear_bit(R5_ReWrite, &dev->flags); 2976 } 2977 if (test_bit(R5_ReadError, &dev->flags)) 2978 clear_bit(R5_Insync, &dev->flags); 2979 if (!test_bit(R5_Insync, &dev->flags)) { 2980 if (s->failed < 2) 2981 s->failed_num[s->failed] = i; 2982 s->failed++; 2983 } 2984 } 2985 spin_unlock_irq(&conf->device_lock); 2986 rcu_read_unlock(); 2987} 2988 2989static void handle_stripe(struct stripe_head *sh) 2990{ 2991 struct stripe_head_state s; 2992 raid5_conf_t *conf = sh->raid_conf; 2993 int i; 2994 int prexor; 2995 int disks = sh->disks; 2996 struct r5dev *pdev, *qdev; 2997 2998 clear_bit(STRIPE_HANDLE, &sh->state); 2999 if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) { 3000 /* already being handled, ensure it gets handled 3001 * again when current action finishes */ 3002 set_bit(STRIPE_HANDLE, &sh->state); 3003 return; 3004 } 3005 3006 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { 3007 set_bit(STRIPE_SYNCING, &sh->state); 3008 clear_bit(STRIPE_INSYNC, &sh->state); 3009 } 3010 clear_bit(STRIPE_DELAYED, &sh->state); 3011 3012 pr_debug("handling stripe %llu, state=%#lx cnt=%d, " 3013 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", 3014 (unsigned long long)sh->sector, sh->state, 3015 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, 3016 sh->check_state, sh->reconstruct_state); 3017 3018 analyse_stripe(sh, &s); 3019 3020 if (unlikely(s.blocked_rdev)) { 3021 if (s.syncing || s.expanding || s.expanded || 3022 s.to_write || s.written) { 3023 set_bit(STRIPE_HANDLE, &sh->state); 3024 goto finish; 3025 } 3026 /* There is nothing for the blocked_rdev to block */ 3027 rdev_dec_pending(s.blocked_rdev, conf->mddev); 3028 s.blocked_rdev = NULL; 3029 } 3030 3031 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { 3032 set_bit(STRIPE_OP_BIOFILL, &s.ops_request); 3033 set_bit(STRIPE_BIOFILL_RUN, &sh->state); 3034 } 3035 3036 pr_debug("locked=%d uptodate=%d to_read=%d" 3037 " to_write=%d failed=%d failed_num=%d,%d\n", 3038 s.locked, s.uptodate, s.to_read, s.to_write, s.failed, 3039 s.failed_num[0], s.failed_num[1]); 3040 /* check if the array has lost more than max_degraded devices and, 3041 * if so, some requests might need to be failed. 3042 */ 3043 if (s.failed > conf->max_degraded && s.to_read+s.to_write+s.written) 3044 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi); 3045 if (s.failed > conf->max_degraded && s.syncing) { 3046 md_done_sync(conf->mddev, STRIPE_SECTORS, 0); 3047 clear_bit(STRIPE_SYNCING, &sh->state); 3048 s.syncing = 0; 3049 } 3050 3051 /* 3052 * might be able to return some write requests if the parity blocks 3053 * are safe, or on a failed drive 3054 */ 3055 pdev = &sh->dev[sh->pd_idx]; 3056 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx) 3057 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx); 3058 qdev = &sh->dev[sh->qd_idx]; 3059 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx) 3060 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx) 3061 || conf->level < 6; 3062 3063 if (s.written && 3064 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags) 3065 && !test_bit(R5_LOCKED, &pdev->flags) 3066 && test_bit(R5_UPTODATE, &pdev->flags)))) && 3067 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags) 3068 && !test_bit(R5_LOCKED, &qdev->flags) 3069 && test_bit(R5_UPTODATE, &qdev->flags))))) 3070 handle_stripe_clean_event(conf, sh, disks, &s.return_bi); 3071 3072 /* Now we might consider reading some blocks, either to check/generate 3073 * parity, or to satisfy requests 3074 * or to load a block that is being partially written. 3075 */ 3076 if (s.to_read || s.non_overwrite 3077 || (conf->level == 6 && s.to_write && s.failed) 3078 || (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) 3079 handle_stripe_fill(sh, &s, disks); 3080 3081 /* Now we check to see if any write operations have recently 3082 * completed 3083 */ 3084 prexor = 0; 3085 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) 3086 prexor = 1; 3087 if (sh->reconstruct_state == reconstruct_state_drain_result || 3088 sh->reconstruct_state == reconstruct_state_prexor_drain_result) { 3089 sh->reconstruct_state = reconstruct_state_idle; 3090 3091 /* All the 'written' buffers and the parity block are ready to 3092 * be written back to disk 3093 */ 3094 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); 3095 BUG_ON(sh->qd_idx >= 0 && 3096 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags)); 3097 for (i = disks; i--; ) { 3098 struct r5dev *dev = &sh->dev[i]; 3099 if (test_bit(R5_LOCKED, &dev->flags) && 3100 (i == sh->pd_idx || i == sh->qd_idx || 3101 dev->written)) { 3102 pr_debug("Writing block %d\n", i); 3103 set_bit(R5_Wantwrite, &dev->flags); 3104 if (prexor) 3105 continue; 3106 if (!test_bit(R5_Insync, &dev->flags) || 3107 ((i == sh->pd_idx || i == sh->qd_idx) && 3108 s.failed == 0)) 3109 set_bit(STRIPE_INSYNC, &sh->state); 3110 } 3111 } 3112 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3113 s.dec_preread_active = 1; 3114 } 3115 3116 /* Now to consider new write requests and what else, if anything 3117 * should be read. We do not handle new writes when: 3118 * 1/ A 'write' operation (copy+xor) is already in flight. 3119 * 2/ A 'check' operation is in flight, as it may clobber the parity 3120 * block. 3121 */ 3122 if (s.to_write && !sh->reconstruct_state && !sh->check_state) 3123 handle_stripe_dirtying(conf, sh, &s, disks); 3124 3125 /* maybe we need to check and possibly fix the parity for this stripe 3126 * Any reads will already have been scheduled, so we just see if enough 3127 * data is available. The parity check is held off while parity 3128 * dependent operations are in flight. 3129 */ 3130 if (sh->check_state || 3131 (s.syncing && s.locked == 0 && 3132 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && 3133 !test_bit(STRIPE_INSYNC, &sh->state))) { 3134 if (conf->level == 6) 3135 handle_parity_checks6(conf, sh, &s, disks); 3136 else 3137 handle_parity_checks5(conf, sh, &s, disks); 3138 } 3139 3140 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { 3141 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3142 clear_bit(STRIPE_SYNCING, &sh->state); 3143 } 3144 3145 /* If the failed drives are just a ReadError, then we might need 3146 * to progress the repair/check process 3147 */ 3148 if (s.failed <= conf->max_degraded && !conf->mddev->ro) 3149 for (i = 0; i < s.failed; i++) { 3150 struct r5dev *dev = &sh->dev[s.failed_num[i]]; 3151 if (test_bit(R5_ReadError, &dev->flags) 3152 && !test_bit(R5_LOCKED, &dev->flags) 3153 && test_bit(R5_UPTODATE, &dev->flags) 3154 ) { 3155 if (!test_bit(R5_ReWrite, &dev->flags)) { 3156 set_bit(R5_Wantwrite, &dev->flags); 3157 set_bit(R5_ReWrite, &dev->flags); 3158 set_bit(R5_LOCKED, &dev->flags); 3159 s.locked++; 3160 } else { 3161 /* let's read it back */ 3162 set_bit(R5_Wantread, &dev->flags); 3163 set_bit(R5_LOCKED, &dev->flags); 3164 s.locked++; 3165 } 3166 } 3167 } 3168 3169 3170 /* Finish reconstruct operations initiated by the expansion process */ 3171 if (sh->reconstruct_state == reconstruct_state_result) { 3172 struct stripe_head *sh_src 3173 = get_active_stripe(conf, sh->sector, 1, 1, 1); 3174 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) { 3175 /* sh cannot be written until sh_src has been read. 3176 * so arrange for sh to be delayed a little 3177 */ 3178 set_bit(STRIPE_DELAYED, &sh->state); 3179 set_bit(STRIPE_HANDLE, &sh->state); 3180 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, 3181 &sh_src->state)) 3182 atomic_inc(&conf->preread_active_stripes); 3183 release_stripe(sh_src); 3184 goto finish; 3185 } 3186 if (sh_src) 3187 release_stripe(sh_src); 3188 3189 sh->reconstruct_state = reconstruct_state_idle; 3190 clear_bit(STRIPE_EXPANDING, &sh->state); 3191 for (i = conf->raid_disks; i--; ) { 3192 set_bit(R5_Wantwrite, &sh->dev[i].flags); 3193 set_bit(R5_LOCKED, &sh->dev[i].flags); 3194 s.locked++; 3195 } 3196 } 3197 3198 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && 3199 !sh->reconstruct_state) { 3200 /* Need to write out all blocks after computing parity */ 3201 sh->disks = conf->raid_disks; 3202 stripe_set_idx(sh->sector, conf, 0, sh); 3203 schedule_reconstruction(sh, &s, 1, 1); 3204 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { 3205 clear_bit(STRIPE_EXPAND_READY, &sh->state); 3206 atomic_dec(&conf->reshape_stripes); 3207 wake_up(&conf->wait_for_overlap); 3208 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3209 } 3210 3211 if (s.expanding && s.locked == 0 && 3212 !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) 3213 handle_stripe_expansion(conf, sh); 3214 3215finish: 3216 /* wait for this device to become unblocked */ 3217 if (unlikely(s.blocked_rdev)) 3218 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev); 3219 3220 if (s.ops_request) 3221 raid_run_ops(sh, s.ops_request); 3222 3223 ops_run_io(sh, &s); 3224 3225 3226 if (s.dec_preread_active) { 3227 /* We delay this until after ops_run_io so that if make_request 3228 * is waiting on a flush, it won't continue until the writes 3229 * have actually been submitted. 3230 */ 3231 atomic_dec(&conf->preread_active_stripes); 3232 if (atomic_read(&conf->preread_active_stripes) < 3233 IO_THRESHOLD) 3234 md_wakeup_thread(conf->mddev->thread); 3235 } 3236 3237 return_io(s.return_bi); 3238 3239 clear_bit(STRIPE_ACTIVE, &sh->state); 3240} 3241 3242static void raid5_activate_delayed(raid5_conf_t *conf) 3243{ 3244 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 3245 while (!list_empty(&conf->delayed_list)) { 3246 struct list_head *l = conf->delayed_list.next; 3247 struct stripe_head *sh; 3248 sh = list_entry(l, struct stripe_head, lru); 3249 list_del_init(l); 3250 clear_bit(STRIPE_DELAYED, &sh->state); 3251 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3252 atomic_inc(&conf->preread_active_stripes); 3253 list_add_tail(&sh->lru, &conf->hold_list); 3254 } 3255 } 3256} 3257 3258static void activate_bit_delay(raid5_conf_t *conf) 3259{ 3260 /* device_lock is held */ 3261 struct list_head head; 3262 list_add(&head, &conf->bitmap_list); 3263 list_del_init(&conf->bitmap_list); 3264 while (!list_empty(&head)) { 3265 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); 3266 list_del_init(&sh->lru); 3267 atomic_inc(&sh->count); 3268 __release_stripe(conf, sh); 3269 } 3270} 3271 3272int md_raid5_congested(mddev_t *mddev, int bits) 3273{ 3274 raid5_conf_t *conf = mddev->private; 3275 3276 /* No difference between reads and writes. Just check 3277 * how busy the stripe_cache is 3278 */ 3279 3280 if (conf->inactive_blocked) 3281 return 1; 3282 if (conf->quiesce) 3283 return 1; 3284 if (list_empty_careful(&conf->inactive_list)) 3285 return 1; 3286 3287 return 0; 3288} 3289EXPORT_SYMBOL_GPL(md_raid5_congested); 3290 3291static int raid5_congested(void *data, int bits) 3292{ 3293 mddev_t *mddev = data; 3294 3295 return mddev_congested(mddev, bits) || 3296 md_raid5_congested(mddev, bits); 3297} 3298 3299/* We want read requests to align with chunks where possible, 3300 * but write requests don't need to. 3301 */ 3302static int raid5_mergeable_bvec(struct request_queue *q, 3303 struct bvec_merge_data *bvm, 3304 struct bio_vec *biovec) 3305{ 3306 mddev_t *mddev = q->queuedata; 3307 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 3308 int max; 3309 unsigned int chunk_sectors = mddev->chunk_sectors; 3310 unsigned int bio_sectors = bvm->bi_size >> 9; 3311 3312 if ((bvm->bi_rw & 1) == WRITE) 3313 return biovec->bv_len; /* always allow writes to be mergeable */ 3314 3315 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3316 chunk_sectors = mddev->new_chunk_sectors; 3317 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; 3318 if (max < 0) max = 0; 3319 if (max <= biovec->bv_len && bio_sectors == 0) 3320 return biovec->bv_len; 3321 else 3322 return max; 3323} 3324 3325 3326static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) 3327{ 3328 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); 3329 unsigned int chunk_sectors = mddev->chunk_sectors; 3330 unsigned int bio_sectors = bio->bi_size >> 9; 3331 3332 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3333 chunk_sectors = mddev->new_chunk_sectors; 3334 return chunk_sectors >= 3335 ((sector & (chunk_sectors - 1)) + bio_sectors); 3336} 3337 3338/* 3339 * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) 3340 * later sampled by raid5d. 3341 */ 3342static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) 3343{ 3344 unsigned long flags; 3345 3346 spin_lock_irqsave(&conf->device_lock, flags); 3347 3348 bi->bi_next = conf->retry_read_aligned_list; 3349 conf->retry_read_aligned_list = bi; 3350 3351 spin_unlock_irqrestore(&conf->device_lock, flags); 3352 md_wakeup_thread(conf->mddev->thread); 3353} 3354 3355 3356static struct bio *remove_bio_from_retry(raid5_conf_t *conf) 3357{ 3358 struct bio *bi; 3359 3360 bi = conf->retry_read_aligned; 3361 if (bi) { 3362 conf->retry_read_aligned = NULL; 3363 return bi; 3364 } 3365 bi = conf->retry_read_aligned_list; 3366 if(bi) { 3367 conf->retry_read_aligned_list = bi->bi_next; 3368 bi->bi_next = NULL; 3369 /* 3370 * this sets the active strip count to 1 and the processed 3371 * strip count to zero (upper 8 bits) 3372 */ 3373 bi->bi_phys_segments = 1; /* biased count of active stripes */ 3374 } 3375 3376 return bi; 3377} 3378 3379 3380/* 3381 * The "raid5_align_endio" should check if the read succeeded and if it 3382 * did, call bio_endio on the original bio (having bio_put the new bio 3383 * first). 3384 * If the read failed.. 3385 */ 3386static void raid5_align_endio(struct bio *bi, int error) 3387{ 3388 struct bio* raid_bi = bi->bi_private; 3389 mddev_t *mddev; 3390 raid5_conf_t *conf; 3391 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 3392 mdk_rdev_t *rdev; 3393 3394 bio_put(bi); 3395 3396 rdev = (void*)raid_bi->bi_next; 3397 raid_bi->bi_next = NULL; 3398 mddev = rdev->mddev; 3399 conf = mddev->private; 3400 3401 rdev_dec_pending(rdev, conf->mddev); 3402 3403 if (!error && uptodate) { 3404 bio_endio(raid_bi, 0); 3405 if (atomic_dec_and_test(&conf->active_aligned_reads)) 3406 wake_up(&conf->wait_for_stripe); 3407 return; 3408 } 3409 3410 3411 pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); 3412 3413 add_bio_to_retry(raid_bi, conf); 3414} 3415 3416static int bio_fits_rdev(struct bio *bi) 3417{ 3418 struct request_queue *q = bdev_get_queue(bi->bi_bdev); 3419 3420 if ((bi->bi_size>>9) > queue_max_sectors(q)) 3421 return 0; 3422 blk_recount_segments(q, bi); 3423 if (bi->bi_phys_segments > queue_max_segments(q)) 3424 return 0; 3425 3426 if (q->merge_bvec_fn) 3427 /* it's too hard to apply the merge_bvec_fn at this stage, 3428 * just just give up 3429 */ 3430 return 0; 3431 3432 return 1; 3433} 3434 3435 3436static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio) 3437{ 3438 raid5_conf_t *conf = mddev->private; 3439 int dd_idx; 3440 struct bio* align_bi; 3441 mdk_rdev_t *rdev; 3442 3443 if (!in_chunk_boundary(mddev, raid_bio)) { 3444 pr_debug("chunk_aligned_read : non aligned\n"); 3445 return 0; 3446 } 3447 /* 3448 * use bio_clone_mddev to make a copy of the bio 3449 */ 3450 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev); 3451 if (!align_bi) 3452 return 0; 3453 /* 3454 * set bi_end_io to a new function, and set bi_private to the 3455 * original bio. 3456 */ 3457 align_bi->bi_end_io = raid5_align_endio; 3458 align_bi->bi_private = raid_bio; 3459 /* 3460 * compute position 3461 */ 3462 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, 3463 0, 3464 &dd_idx, NULL); 3465 3466 rcu_read_lock(); 3467 rdev = rcu_dereference(conf->disks[dd_idx].rdev); 3468 if (rdev && test_bit(In_sync, &rdev->flags)) { 3469 atomic_inc(&rdev->nr_pending); 3470 rcu_read_unlock(); 3471 raid_bio->bi_next = (void*)rdev; 3472 align_bi->bi_bdev = rdev->bdev; 3473 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); 3474 align_bi->bi_sector += rdev->data_offset; 3475 3476 if (!bio_fits_rdev(align_bi)) { 3477 /* too big in some way */ 3478 bio_put(align_bi); 3479 rdev_dec_pending(rdev, mddev); 3480 return 0; 3481 } 3482 3483 spin_lock_irq(&conf->device_lock); 3484 wait_event_lock_irq(conf->wait_for_stripe, 3485 conf->quiesce == 0, 3486 conf->device_lock, /* nothing */); 3487 atomic_inc(&conf->active_aligned_reads); 3488 spin_unlock_irq(&conf->device_lock); 3489 3490 generic_make_request(align_bi); 3491 return 1; 3492 } else { 3493 rcu_read_unlock(); 3494 bio_put(align_bi); 3495 return 0; 3496 } 3497} 3498 3499/* __get_priority_stripe - get the next stripe to process 3500 * 3501 * Full stripe writes are allowed to pass preread active stripes up until 3502 * the bypass_threshold is exceeded. In general the bypass_count 3503 * increments when the handle_list is handled before the hold_list; however, it 3504 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a 3505 * stripe with in flight i/o. The bypass_count will be reset when the 3506 * head of the hold_list has changed, i.e. the head was promoted to the 3507 * handle_list. 3508 */ 3509static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf) 3510{ 3511 struct stripe_head *sh; 3512 3513 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", 3514 __func__, 3515 list_empty(&conf->handle_list) ? "empty" : "busy", 3516 list_empty(&conf->hold_list) ? "empty" : "busy", 3517 atomic_read(&conf->pending_full_writes), conf->bypass_count); 3518 3519 if (!list_empty(&conf->handle_list)) { 3520 sh = list_entry(conf->handle_list.next, typeof(*sh), lru); 3521 3522 if (list_empty(&conf->hold_list)) 3523 conf->bypass_count = 0; 3524 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { 3525 if (conf->hold_list.next == conf->last_hold) 3526 conf->bypass_count++; 3527 else { 3528 conf->last_hold = conf->hold_list.next; 3529 conf->bypass_count -= conf->bypass_threshold; 3530 if (conf->bypass_count < 0) 3531 conf->bypass_count = 0; 3532 } 3533 } 3534 } else if (!list_empty(&conf->hold_list) && 3535 ((conf->bypass_threshold && 3536 conf->bypass_count > conf->bypass_threshold) || 3537 atomic_read(&conf->pending_full_writes) == 0)) { 3538 sh = list_entry(conf->hold_list.next, 3539 typeof(*sh), lru); 3540 conf->bypass_count -= conf->bypass_threshold; 3541 if (conf->bypass_count < 0) 3542 conf->bypass_count = 0; 3543 } else 3544 return NULL; 3545 3546 list_del_init(&sh->lru); 3547 atomic_inc(&sh->count); 3548 BUG_ON(atomic_read(&sh->count) != 1); 3549 return sh; 3550} 3551 3552static int make_request(mddev_t *mddev, struct bio * bi) 3553{ 3554 raid5_conf_t *conf = mddev->private; 3555 int dd_idx; 3556 sector_t new_sector; 3557 sector_t logical_sector, last_sector; 3558 struct stripe_head *sh; 3559 const int rw = bio_data_dir(bi); 3560 int remaining; 3561 int plugged; 3562 3563 if (unlikely(bi->bi_rw & REQ_FLUSH)) { 3564 md_flush_request(mddev, bi); 3565 return 0; 3566 } 3567 3568 md_write_start(mddev, bi); 3569 3570 if (rw == READ && 3571 mddev->reshape_position == MaxSector && 3572 chunk_aligned_read(mddev,bi)) 3573 return 0; 3574 3575 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 3576 last_sector = bi->bi_sector + (bi->bi_size>>9); 3577 bi->bi_next = NULL; 3578 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ 3579 3580 plugged = mddev_check_plugged(mddev); 3581 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 3582 DEFINE_WAIT(w); 3583 int disks, data_disks; 3584 int previous; 3585 3586 retry: 3587 previous = 0; 3588 disks = conf->raid_disks; 3589 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 3590 if (unlikely(conf->reshape_progress != MaxSector)) { 3591 /* spinlock is needed as reshape_progress may be 3592 * 64bit on a 32bit platform, and so it might be 3593 * possible to see a half-updated value 3594 * Of course reshape_progress could change after 3595 * the lock is dropped, so once we get a reference 3596 * to the stripe that we think it is, we will have 3597 * to check again. 3598 */ 3599 spin_lock_irq(&conf->device_lock); 3600 if (mddev->delta_disks < 0 3601 ? logical_sector < conf->reshape_progress 3602 : logical_sector >= conf->reshape_progress) { 3603 disks = conf->previous_raid_disks; 3604 previous = 1; 3605 } else { 3606 if (mddev->delta_disks < 0 3607 ? logical_sector < conf->reshape_safe 3608 : logical_sector >= conf->reshape_safe) { 3609 spin_unlock_irq(&conf->device_lock); 3610 schedule(); 3611 goto retry; 3612 } 3613 } 3614 spin_unlock_irq(&conf->device_lock); 3615 } 3616 data_disks = disks - conf->max_degraded; 3617 3618 new_sector = raid5_compute_sector(conf, logical_sector, 3619 previous, 3620 &dd_idx, NULL); 3621 pr_debug("raid456: make_request, sector %llu logical %llu\n", 3622 (unsigned long long)new_sector, 3623 (unsigned long long)logical_sector); 3624 3625 sh = get_active_stripe(conf, new_sector, previous, 3626 (bi->bi_rw&RWA_MASK), 0); 3627 if (sh) { 3628 if (unlikely(previous)) { 3629 /* expansion might have moved on while waiting for a 3630 * stripe, so we must do the range check again. 3631 * Expansion could still move past after this 3632 * test, but as we are holding a reference to 3633 * 'sh', we know that if that happens, 3634 * STRIPE_EXPANDING will get set and the expansion 3635 * won't proceed until we finish with the stripe. 3636 */ 3637 int must_retry = 0; 3638 spin_lock_irq(&conf->device_lock); 3639 if (mddev->delta_disks < 0 3640 ? logical_sector >= conf->reshape_progress 3641 : logical_sector < conf->reshape_progress) 3642 /* mismatch, need to try again */ 3643 must_retry = 1; 3644 spin_unlock_irq(&conf->device_lock); 3645 if (must_retry) { 3646 release_stripe(sh); 3647 schedule(); 3648 goto retry; 3649 } 3650 } 3651 3652 if (rw == WRITE && 3653 logical_sector >= mddev->suspend_lo && 3654 logical_sector < mddev->suspend_hi) { 3655 release_stripe(sh); 3656 /* As the suspend_* range is controlled by 3657 * userspace, we want an interruptible 3658 * wait. 3659 */ 3660 flush_signals(current); 3661 prepare_to_wait(&conf->wait_for_overlap, 3662 &w, TASK_INTERRUPTIBLE); 3663 if (logical_sector >= mddev->suspend_lo && 3664 logical_sector < mddev->suspend_hi) 3665 schedule(); 3666 goto retry; 3667 } 3668 3669 if (test_bit(STRIPE_EXPANDING, &sh->state) || 3670 !add_stripe_bio(sh, bi, dd_idx, rw)) { 3671 /* Stripe is busy expanding or 3672 * add failed due to overlap. Flush everything 3673 * and wait a while 3674 */ 3675 md_wakeup_thread(mddev->thread); 3676 release_stripe(sh); 3677 schedule(); 3678 goto retry; 3679 } 3680 finish_wait(&conf->wait_for_overlap, &w); 3681 set_bit(STRIPE_HANDLE, &sh->state); 3682 clear_bit(STRIPE_DELAYED, &sh->state); 3683 if ((bi->bi_rw & REQ_SYNC) && 3684 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3685 atomic_inc(&conf->preread_active_stripes); 3686 release_stripe(sh); 3687 } else { 3688 /* cannot get stripe for read-ahead, just give-up */ 3689 clear_bit(BIO_UPTODATE, &bi->bi_flags); 3690 finish_wait(&conf->wait_for_overlap, &w); 3691 break; 3692 } 3693 3694 } 3695 if (!plugged) 3696 md_wakeup_thread(mddev->thread); 3697 3698 spin_lock_irq(&conf->device_lock); 3699 remaining = raid5_dec_bi_phys_segments(bi); 3700 spin_unlock_irq(&conf->device_lock); 3701 if (remaining == 0) { 3702 3703 if ( rw == WRITE ) 3704 md_write_end(mddev); 3705 3706 bio_endio(bi, 0); 3707 } 3708 3709 return 0; 3710} 3711 3712static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks); 3713 3714static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) 3715{ 3716 /* reshaping is quite different to recovery/resync so it is 3717 * handled quite separately ... here. 3718 * 3719 * On each call to sync_request, we gather one chunk worth of 3720 * destination stripes and flag them as expanding. 3721 * Then we find all the source stripes and request reads. 3722 * As the reads complete, handle_stripe will copy the data 3723 * into the destination stripe and release that stripe. 3724 */ 3725 raid5_conf_t *conf = mddev->private; 3726 struct stripe_head *sh; 3727 sector_t first_sector, last_sector; 3728 int raid_disks = conf->previous_raid_disks; 3729 int data_disks = raid_disks - conf->max_degraded; 3730 int new_data_disks = conf->raid_disks - conf->max_degraded; 3731 int i; 3732 int dd_idx; 3733 sector_t writepos, readpos, safepos; 3734 sector_t stripe_addr; 3735 int reshape_sectors; 3736 struct list_head stripes; 3737 3738 if (sector_nr == 0) { 3739 /* If restarting in the middle, skip the initial sectors */ 3740 if (mddev->delta_disks < 0 && 3741 conf->reshape_progress < raid5_size(mddev, 0, 0)) { 3742 sector_nr = raid5_size(mddev, 0, 0) 3743 - conf->reshape_progress; 3744 } else if (mddev->delta_disks >= 0 && 3745 conf->reshape_progress > 0) 3746 sector_nr = conf->reshape_progress; 3747 sector_div(sector_nr, new_data_disks); 3748 if (sector_nr) { 3749 mddev->curr_resync_completed = sector_nr; 3750 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3751 *skipped = 1; 3752 return sector_nr; 3753 } 3754 } 3755 3756 /* We need to process a full chunk at a time. 3757 * If old and new chunk sizes differ, we need to process the 3758 * largest of these 3759 */ 3760 if (mddev->new_chunk_sectors > mddev->chunk_sectors) 3761 reshape_sectors = mddev->new_chunk_sectors; 3762 else 3763 reshape_sectors = mddev->chunk_sectors; 3764 3765 /* we update the metadata when there is more than 3Meg 3766 * in the block range (that is rather arbitrary, should 3767 * probably be time based) or when the data about to be 3768 * copied would over-write the source of the data at 3769 * the front of the range. 3770 * i.e. one new_stripe along from reshape_progress new_maps 3771 * to after where reshape_safe old_maps to 3772 */ 3773 writepos = conf->reshape_progress; 3774 sector_div(writepos, new_data_disks); 3775 readpos = conf->reshape_progress; 3776 sector_div(readpos, data_disks); 3777 safepos = conf->reshape_safe; 3778 sector_div(safepos, data_disks); 3779 if (mddev->delta_disks < 0) { 3780 writepos -= min_t(sector_t, reshape_sectors, writepos); 3781 readpos += reshape_sectors; 3782 safepos += reshape_sectors; 3783 } else { 3784 writepos += reshape_sectors; 3785 readpos -= min_t(sector_t, reshape_sectors, readpos); 3786 safepos -= min_t(sector_t, reshape_sectors, safepos); 3787 } 3788 3789 /* 'writepos' is the most advanced device address we might write. 3790 * 'readpos' is the least advanced device address we might read. 3791 * 'safepos' is the least address recorded in the metadata as having 3792 * been reshaped. 3793 * If 'readpos' is behind 'writepos', then there is no way that we can 3794 * ensure safety in the face of a crash - that must be done by userspace 3795 * making a backup of the data. So in that case there is no particular 3796 * rush to update metadata. 3797 * Otherwise if 'safepos' is behind 'writepos', then we really need to 3798 * update the metadata to advance 'safepos' to match 'readpos' so that 3799 * we can be safe in the event of a crash. 3800 * So we insist on updating metadata if safepos is behind writepos and 3801 * readpos is beyond writepos. 3802 * In any case, update the metadata every 10 seconds. 3803 * Maybe that number should be configurable, but I'm not sure it is 3804 * worth it.... maybe it could be a multiple of safemode_delay??? 3805 */ 3806 if ((mddev->delta_disks < 0 3807 ? (safepos > writepos && readpos < writepos) 3808 : (safepos < writepos && readpos > writepos)) || 3809 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { 3810 /* Cannot proceed until we've updated the superblock... */ 3811 wait_event(conf->wait_for_overlap, 3812 atomic_read(&conf->reshape_stripes)==0); 3813 mddev->reshape_position = conf->reshape_progress; 3814 mddev->curr_resync_completed = sector_nr; 3815 conf->reshape_checkpoint = jiffies; 3816 set_bit(MD_CHANGE_DEVS, &mddev->flags); 3817 md_wakeup_thread(mddev->thread); 3818 wait_event(mddev->sb_wait, mddev->flags == 0 || 3819 kthread_should_stop()); 3820 spin_lock_irq(&conf->device_lock); 3821 conf->reshape_safe = mddev->reshape_position; 3822 spin_unlock_irq(&conf->device_lock); 3823 wake_up(&conf->wait_for_overlap); 3824 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3825 } 3826 3827 if (mddev->delta_disks < 0) { 3828 BUG_ON(conf->reshape_progress == 0); 3829 stripe_addr = writepos; 3830 BUG_ON((mddev->dev_sectors & 3831 ~((sector_t)reshape_sectors - 1)) 3832 - reshape_sectors - stripe_addr 3833 != sector_nr); 3834 } else { 3835 BUG_ON(writepos != sector_nr + reshape_sectors); 3836 stripe_addr = sector_nr; 3837 } 3838 INIT_LIST_HEAD(&stripes); 3839 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { 3840 int j; 3841 int skipped_disk = 0; 3842 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1); 3843 set_bit(STRIPE_EXPANDING, &sh->state); 3844 atomic_inc(&conf->reshape_stripes); 3845 /* If any of this stripe is beyond the end of the old 3846 * array, then we need to zero those blocks 3847 */ 3848 for (j=sh->disks; j--;) { 3849 sector_t s; 3850 if (j == sh->pd_idx) 3851 continue; 3852 if (conf->level == 6 && 3853 j == sh->qd_idx) 3854 continue; 3855 s = compute_blocknr(sh, j, 0); 3856 if (s < raid5_size(mddev, 0, 0)) { 3857 skipped_disk = 1; 3858 continue; 3859 } 3860 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); 3861 set_bit(R5_Expanded, &sh->dev[j].flags); 3862 set_bit(R5_UPTODATE, &sh->dev[j].flags); 3863 } 3864 if (!skipped_disk) { 3865 set_bit(STRIPE_EXPAND_READY, &sh->state); 3866 set_bit(STRIPE_HANDLE, &sh->state); 3867 } 3868 list_add(&sh->lru, &stripes); 3869 } 3870 spin_lock_irq(&conf->device_lock); 3871 if (mddev->delta_disks < 0) 3872 conf->reshape_progress -= reshape_sectors * new_data_disks; 3873 else 3874 conf->reshape_progress += reshape_sectors * new_data_disks; 3875 spin_unlock_irq(&conf->device_lock); 3876 /* Ok, those stripe are ready. We can start scheduling 3877 * reads on the source stripes. 3878 * The source stripes are determined by mapping the first and last 3879 * block on the destination stripes. 3880 */ 3881 first_sector = 3882 raid5_compute_sector(conf, stripe_addr*(new_data_disks), 3883 1, &dd_idx, NULL); 3884 last_sector = 3885 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) 3886 * new_data_disks - 1), 3887 1, &dd_idx, NULL); 3888 if (last_sector >= mddev->dev_sectors) 3889 last_sector = mddev->dev_sectors - 1; 3890 while (first_sector <= last_sector) { 3891 sh = get_active_stripe(conf, first_sector, 1, 0, 1); 3892 set_bit(STRIPE_EXPAND_SOURCE, &sh->state); 3893 set_bit(STRIPE_HANDLE, &sh->state); 3894 release_stripe(sh); 3895 first_sector += STRIPE_SECTORS; 3896 } 3897 /* Now that the sources are clearly marked, we can release 3898 * the destination stripes 3899 */ 3900 while (!list_empty(&stripes)) { 3901 sh = list_entry(stripes.next, struct stripe_head, lru); 3902 list_del_init(&sh->lru); 3903 release_stripe(sh); 3904 } 3905 /* If this takes us to the resync_max point where we have to pause, 3906 * then we need to write out the superblock. 3907 */ 3908 sector_nr += reshape_sectors; 3909 if ((sector_nr - mddev->curr_resync_completed) * 2 3910 >= mddev->resync_max - mddev->curr_resync_completed) { 3911 /* Cannot proceed until we've updated the superblock... */ 3912 wait_event(conf->wait_for_overlap, 3913 atomic_read(&conf->reshape_stripes) == 0); 3914 mddev->reshape_position = conf->reshape_progress; 3915 mddev->curr_resync_completed = sector_nr; 3916 conf->reshape_checkpoint = jiffies; 3917 set_bit(MD_CHANGE_DEVS, &mddev->flags); 3918 md_wakeup_thread(mddev->thread); 3919 wait_event(mddev->sb_wait, 3920 !test_bit(MD_CHANGE_DEVS, &mddev->flags) 3921 || kthread_should_stop()); 3922 spin_lock_irq(&conf->device_lock); 3923 conf->reshape_safe = mddev->reshape_position; 3924 spin_unlock_irq(&conf->device_lock); 3925 wake_up(&conf->wait_for_overlap); 3926 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3927 } 3928 return reshape_sectors; 3929} 3930 3931/* FIXME go_faster isn't used */ 3932static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) 3933{ 3934 raid5_conf_t *conf = mddev->private; 3935 struct stripe_head *sh; 3936 sector_t max_sector = mddev->dev_sectors; 3937 sector_t sync_blocks; 3938 int still_degraded = 0; 3939 int i; 3940 3941 if (sector_nr >= max_sector) { 3942 /* just being told to finish up .. nothing much to do */ 3943 3944 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { 3945 end_reshape(conf); 3946 return 0; 3947 } 3948 3949 if (mddev->curr_resync < max_sector) /* aborted */ 3950 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 3951 &sync_blocks, 1); 3952 else /* completed sync */ 3953 conf->fullsync = 0; 3954 bitmap_close_sync(mddev->bitmap); 3955 3956 return 0; 3957 } 3958 3959 /* Allow raid5_quiesce to complete */ 3960 wait_event(conf->wait_for_overlap, conf->quiesce != 2); 3961 3962 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) 3963 return reshape_request(mddev, sector_nr, skipped); 3964 3965 /* No need to check resync_max as we never do more than one 3966 * stripe, and as resync_max will always be on a chunk boundary, 3967 * if the check in md_do_sync didn't fire, there is no chance 3968 * of overstepping resync_max here 3969 */ 3970 3971 /* if there is too many failed drives and we are trying 3972 * to resync, then assert that we are finished, because there is 3973 * nothing we can do. 3974 */ 3975 if (mddev->degraded >= conf->max_degraded && 3976 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 3977 sector_t rv = mddev->dev_sectors - sector_nr; 3978 *skipped = 1; 3979 return rv; 3980 } 3981 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 3982 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 3983 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { 3984 /* we can skip this block, and probably more */ 3985 sync_blocks /= STRIPE_SECTORS; 3986 *skipped = 1; 3987 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ 3988 } 3989 3990 3991 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 3992 3993 sh = get_active_stripe(conf, sector_nr, 0, 1, 0); 3994 if (sh == NULL) { 3995 sh = get_active_stripe(conf, sector_nr, 0, 0, 0); 3996 /* make sure we don't swamp the stripe cache if someone else 3997 * is trying to get access 3998 */ 3999 schedule_timeout_uninterruptible(1); 4000 } 4001 /* Need to check if array will still be degraded after recovery/resync 4002 * We don't need to check the 'failed' flag as when that gets set, 4003 * recovery aborts. 4004 */ 4005 for (i = 0; i < conf->raid_disks; i++) 4006 if (conf->disks[i].rdev == NULL) 4007 still_degraded = 1; 4008 4009 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); 4010 4011 set_bit(STRIPE_SYNC_REQUESTED, &sh->state); 4012 4013 handle_stripe(sh); 4014 release_stripe(sh); 4015 4016 return STRIPE_SECTORS; 4017} 4018 4019static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) 4020{ 4021 /* We may not be able to submit a whole bio at once as there 4022 * may not be enough stripe_heads available. 4023 * We cannot pre-allocate enough stripe_heads as we may need 4024 * more than exist in the cache (if we allow ever large chunks). 4025 * So we do one stripe head at a time and record in 4026 * ->bi_hw_segments how many have been done. 4027 * 4028 * We *know* that this entire raid_bio is in one chunk, so 4029 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. 4030 */ 4031 struct stripe_head *sh; 4032 int dd_idx; 4033 sector_t sector, logical_sector, last_sector; 4034 int scnt = 0; 4035 int remaining; 4036 int handled = 0; 4037 4038 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 4039 sector = raid5_compute_sector(conf, logical_sector, 4040 0, &dd_idx, NULL); 4041 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); 4042 4043 for (; logical_sector < last_sector; 4044 logical_sector += STRIPE_SECTORS, 4045 sector += STRIPE_SECTORS, 4046 scnt++) { 4047 4048 if (scnt < raid5_bi_hw_segments(raid_bio)) 4049 /* already done this stripe */ 4050 continue; 4051 4052 sh = get_active_stripe(conf, sector, 0, 1, 0); 4053 4054 if (!sh) { 4055 /* failed to get a stripe - must wait */ 4056 raid5_set_bi_hw_segments(raid_bio, scnt); 4057 conf->retry_read_aligned = raid_bio; 4058 return handled; 4059 } 4060 4061 set_bit(R5_ReadError, &sh->dev[dd_idx].flags); 4062 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { 4063 release_stripe(sh); 4064 raid5_set_bi_hw_segments(raid_bio, scnt); 4065 conf->retry_read_aligned = raid_bio; 4066 return handled; 4067 } 4068 4069 handle_stripe(sh); 4070 release_stripe(sh); 4071 handled++; 4072 } 4073 spin_lock_irq(&conf->device_lock); 4074 remaining = raid5_dec_bi_phys_segments(raid_bio); 4075 spin_unlock_irq(&conf->device_lock); 4076 if (remaining == 0) 4077 bio_endio(raid_bio, 0); 4078 if (atomic_dec_and_test(&conf->active_aligned_reads)) 4079 wake_up(&conf->wait_for_stripe); 4080 return handled; 4081} 4082 4083 4084/* 4085 * This is our raid5 kernel thread. 4086 * 4087 * We scan the hash table for stripes which can be handled now. 4088 * During the scan, completed stripes are saved for us by the interrupt 4089 * handler, so that they will not have to wait for our next wakeup. 4090 */ 4091static void raid5d(mddev_t *mddev) 4092{ 4093 struct stripe_head *sh; 4094 raid5_conf_t *conf = mddev->private; 4095 int handled; 4096 struct blk_plug plug; 4097 4098 pr_debug("+++ raid5d active\n"); 4099 4100 md_check_recovery(mddev); 4101 4102 blk_start_plug(&plug); 4103 handled = 0; 4104 spin_lock_irq(&conf->device_lock); 4105 while (1) { 4106 struct bio *bio; 4107 4108 if (atomic_read(&mddev->plug_cnt) == 0 && 4109 !list_empty(&conf->bitmap_list)) { 4110 /* Now is a good time to flush some bitmap updates */ 4111 conf->seq_flush++; 4112 spin_unlock_irq(&conf->device_lock); 4113 bitmap_unplug(mddev->bitmap); 4114 spin_lock_irq(&conf->device_lock); 4115 conf->seq_write = conf->seq_flush; 4116 activate_bit_delay(conf); 4117 } 4118 if (atomic_read(&mddev->plug_cnt) == 0) 4119 raid5_activate_delayed(conf); 4120 4121 while ((bio = remove_bio_from_retry(conf))) { 4122 int ok; 4123 spin_unlock_irq(&conf->device_lock); 4124 ok = retry_aligned_read(conf, bio); 4125 spin_lock_irq(&conf->device_lock); 4126 if (!ok) 4127 break; 4128 handled++; 4129 } 4130 4131 sh = __get_priority_stripe(conf); 4132 4133 if (!sh) 4134 break; 4135 spin_unlock_irq(&conf->device_lock); 4136 4137 handled++; 4138 handle_stripe(sh); 4139 release_stripe(sh); 4140 cond_resched(); 4141 4142 spin_lock_irq(&conf->device_lock); 4143 } 4144 pr_debug("%d stripes handled\n", handled); 4145 4146 spin_unlock_irq(&conf->device_lock); 4147 4148 async_tx_issue_pending_all(); 4149 blk_finish_plug(&plug); 4150 4151 pr_debug("--- raid5d inactive\n"); 4152} 4153 4154static ssize_t 4155raid5_show_stripe_cache_size(mddev_t *mddev, char *page) 4156{ 4157 raid5_conf_t *conf = mddev->private; 4158 if (conf) 4159 return sprintf(page, "%d\n", conf->max_nr_stripes); 4160 else 4161 return 0; 4162} 4163 4164int 4165raid5_set_cache_size(mddev_t *mddev, int size) 4166{ 4167 raid5_conf_t *conf = mddev->private; 4168 int err; 4169 4170 if (size <= 16 || size > 32768) 4171 return -EINVAL; 4172 while (size < conf->max_nr_stripes) { 4173 if (drop_one_stripe(conf)) 4174 conf->max_nr_stripes--; 4175 else 4176 break; 4177 } 4178 err = md_allow_write(mddev); 4179 if (err) 4180 return err; 4181 while (size > conf->max_nr_stripes) { 4182 if (grow_one_stripe(conf)) 4183 conf->max_nr_stripes++; 4184 else break; 4185 } 4186 return 0; 4187} 4188EXPORT_SYMBOL(raid5_set_cache_size); 4189 4190static ssize_t 4191raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) 4192{ 4193 raid5_conf_t *conf = mddev->private; 4194 unsigned long new; 4195 int err; 4196 4197 if (len >= PAGE_SIZE) 4198 return -EINVAL; 4199 if (!conf) 4200 return -ENODEV; 4201 4202 if (strict_strtoul(page, 10, &new)) 4203 return -EINVAL; 4204 err = raid5_set_cache_size(mddev, new); 4205 if (err) 4206 return err; 4207 return len; 4208} 4209 4210static struct md_sysfs_entry 4211raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, 4212 raid5_show_stripe_cache_size, 4213 raid5_store_stripe_cache_size); 4214 4215static ssize_t 4216raid5_show_preread_threshold(mddev_t *mddev, char *page) 4217{ 4218 raid5_conf_t *conf = mddev->private; 4219 if (conf) 4220 return sprintf(page, "%d\n", conf->bypass_threshold); 4221 else 4222 return 0; 4223} 4224 4225static ssize_t 4226raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len) 4227{ 4228 raid5_conf_t *conf = mddev->private; 4229 unsigned long new; 4230 if (len >= PAGE_SIZE) 4231 return -EINVAL; 4232 if (!conf) 4233 return -ENODEV; 4234 4235 if (strict_strtoul(page, 10, &new)) 4236 return -EINVAL; 4237 if (new > conf->max_nr_stripes) 4238 return -EINVAL; 4239 conf->bypass_threshold = new; 4240 return len; 4241} 4242 4243static struct md_sysfs_entry 4244raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, 4245 S_IRUGO | S_IWUSR, 4246 raid5_show_preread_threshold, 4247 raid5_store_preread_threshold); 4248 4249static ssize_t 4250stripe_cache_active_show(mddev_t *mddev, char *page) 4251{ 4252 raid5_conf_t *conf = mddev->private; 4253 if (conf) 4254 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); 4255 else 4256 return 0; 4257} 4258 4259static struct md_sysfs_entry 4260raid5_stripecache_active = __ATTR_RO(stripe_cache_active); 4261 4262static struct attribute *raid5_attrs[] = { 4263 &raid5_stripecache_size.attr, 4264 &raid5_stripecache_active.attr, 4265 &raid5_preread_bypass_threshold.attr, 4266 NULL, 4267}; 4268static struct attribute_group raid5_attrs_group = { 4269 .name = NULL, 4270 .attrs = raid5_attrs, 4271}; 4272 4273static sector_t 4274raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks) 4275{ 4276 raid5_conf_t *conf = mddev->private; 4277 4278 if (!sectors) 4279 sectors = mddev->dev_sectors; 4280 if (!raid_disks) 4281 /* size is defined by the smallest of previous and new size */ 4282 raid_disks = min(conf->raid_disks, conf->previous_raid_disks); 4283 4284 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 4285 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); 4286 return sectors * (raid_disks - conf->max_degraded); 4287} 4288 4289static void raid5_free_percpu(raid5_conf_t *conf) 4290{ 4291 struct raid5_percpu *percpu; 4292 unsigned long cpu; 4293 4294 if (!conf->percpu) 4295 return; 4296 4297 get_online_cpus(); 4298 for_each_possible_cpu(cpu) { 4299 percpu = per_cpu_ptr(conf->percpu, cpu); 4300 safe_put_page(percpu->spare_page); 4301 kfree(percpu->scribble); 4302 } 4303#ifdef CONFIG_HOTPLUG_CPU 4304 unregister_cpu_notifier(&conf->cpu_notify); 4305#endif 4306 put_online_cpus(); 4307 4308 free_percpu(conf->percpu); 4309} 4310 4311static void free_conf(raid5_conf_t *conf) 4312{ 4313 shrink_stripes(conf); 4314 raid5_free_percpu(conf); 4315 kfree(conf->disks); 4316 kfree(conf->stripe_hashtbl); 4317 kfree(conf); 4318} 4319 4320#ifdef CONFIG_HOTPLUG_CPU 4321static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, 4322 void *hcpu) 4323{ 4324 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify); 4325 long cpu = (long)hcpu; 4326 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); 4327 4328 switch (action) { 4329 case CPU_UP_PREPARE: 4330 case CPU_UP_PREPARE_FROZEN: 4331 if (conf->level == 6 && !percpu->spare_page) 4332 percpu->spare_page = alloc_page(GFP_KERNEL); 4333 if (!percpu->scribble) 4334 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4335 4336 if (!percpu->scribble || 4337 (conf->level == 6 && !percpu->spare_page)) { 4338 safe_put_page(percpu->spare_page); 4339 kfree(percpu->scribble); 4340 pr_err("%s: failed memory allocation for cpu%ld\n", 4341 __func__, cpu); 4342 return notifier_from_errno(-ENOMEM); 4343 } 4344 break; 4345 case CPU_DEAD: 4346 case CPU_DEAD_FROZEN: 4347 safe_put_page(percpu->spare_page); 4348 kfree(percpu->scribble); 4349 percpu->spare_page = NULL; 4350 percpu->scribble = NULL; 4351 break; 4352 default: 4353 break; 4354 } 4355 return NOTIFY_OK; 4356} 4357#endif 4358 4359static int raid5_alloc_percpu(raid5_conf_t *conf) 4360{ 4361 unsigned long cpu; 4362 struct page *spare_page; 4363 struct raid5_percpu __percpu *allcpus; 4364 void *scribble; 4365 int err; 4366 4367 allcpus = alloc_percpu(struct raid5_percpu); 4368 if (!allcpus) 4369 return -ENOMEM; 4370 conf->percpu = allcpus; 4371 4372 get_online_cpus(); 4373 err = 0; 4374 for_each_present_cpu(cpu) { 4375 if (conf->level == 6) { 4376 spare_page = alloc_page(GFP_KERNEL); 4377 if (!spare_page) { 4378 err = -ENOMEM; 4379 break; 4380 } 4381 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page; 4382 } 4383 scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4384 if (!scribble) { 4385 err = -ENOMEM; 4386 break; 4387 } 4388 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; 4389 } 4390#ifdef CONFIG_HOTPLUG_CPU 4391 conf->cpu_notify.notifier_call = raid456_cpu_notify; 4392 conf->cpu_notify.priority = 0; 4393 if (err == 0) 4394 err = register_cpu_notifier(&conf->cpu_notify); 4395#endif 4396 put_online_cpus(); 4397 4398 return err; 4399} 4400 4401static raid5_conf_t *setup_conf(mddev_t *mddev) 4402{ 4403 raid5_conf_t *conf; 4404 int raid_disk, memory, max_disks; 4405 mdk_rdev_t *rdev; 4406 struct disk_info *disk; 4407 4408 if (mddev->new_level != 5 4409 && mddev->new_level != 4 4410 && mddev->new_level != 6) { 4411 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n", 4412 mdname(mddev), mddev->new_level); 4413 return ERR_PTR(-EIO); 4414 } 4415 if ((mddev->new_level == 5 4416 && !algorithm_valid_raid5(mddev->new_layout)) || 4417 (mddev->new_level == 6 4418 && !algorithm_valid_raid6(mddev->new_layout))) { 4419 printk(KERN_ERR "md/raid:%s: layout %d not supported\n", 4420 mdname(mddev), mddev->new_layout); 4421 return ERR_PTR(-EIO); 4422 } 4423 if (mddev->new_level == 6 && mddev->raid_disks < 4) { 4424 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n", 4425 mdname(mddev), mddev->raid_disks); 4426 return ERR_PTR(-EINVAL); 4427 } 4428 4429 if (!mddev->new_chunk_sectors || 4430 (mddev->new_chunk_sectors << 9) % PAGE_SIZE || 4431 !is_power_of_2(mddev->new_chunk_sectors)) { 4432 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n", 4433 mdname(mddev), mddev->new_chunk_sectors << 9); 4434 return ERR_PTR(-EINVAL); 4435 } 4436 4437 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL); 4438 if (conf == NULL) 4439 goto abort; 4440 spin_lock_init(&conf->device_lock); 4441 init_waitqueue_head(&conf->wait_for_stripe); 4442 init_waitqueue_head(&conf->wait_for_overlap); 4443 INIT_LIST_HEAD(&conf->handle_list); 4444 INIT_LIST_HEAD(&conf->hold_list); 4445 INIT_LIST_HEAD(&conf->delayed_list); 4446 INIT_LIST_HEAD(&conf->bitmap_list); 4447 INIT_LIST_HEAD(&conf->inactive_list); 4448 atomic_set(&conf->active_stripes, 0); 4449 atomic_set(&conf->preread_active_stripes, 0); 4450 atomic_set(&conf->active_aligned_reads, 0); 4451 conf->bypass_threshold = BYPASS_THRESHOLD; 4452 4453 conf->raid_disks = mddev->raid_disks; 4454 if (mddev->reshape_position == MaxSector) 4455 conf->previous_raid_disks = mddev->raid_disks; 4456 else 4457 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; 4458 max_disks = max(conf->raid_disks, conf->previous_raid_disks); 4459 conf->scribble_len = scribble_len(max_disks); 4460 4461 conf->disks = kzalloc(max_disks * sizeof(struct disk_info), 4462 GFP_KERNEL); 4463 if (!conf->disks) 4464 goto abort; 4465 4466 conf->mddev = mddev; 4467 4468 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 4469 goto abort; 4470 4471 conf->level = mddev->new_level; 4472 if (raid5_alloc_percpu(conf) != 0) 4473 goto abort; 4474 4475 pr_debug("raid456: run(%s) called.\n", mdname(mddev)); 4476 4477 list_for_each_entry(rdev, &mddev->disks, same_set) { 4478 raid_disk = rdev->raid_disk; 4479 if (raid_disk >= max_disks 4480 || raid_disk < 0) 4481 continue; 4482 disk = conf->disks + raid_disk; 4483 4484 disk->rdev = rdev; 4485 4486 if (test_bit(In_sync, &rdev->flags)) { 4487 char b[BDEVNAME_SIZE]; 4488 printk(KERN_INFO "md/raid:%s: device %s operational as raid" 4489 " disk %d\n", 4490 mdname(mddev), bdevname(rdev->bdev, b), raid_disk); 4491 } else if (rdev->saved_raid_disk != raid_disk) 4492 /* Cannot rely on bitmap to complete recovery */ 4493 conf->fullsync = 1; 4494 } 4495 4496 conf->chunk_sectors = mddev->new_chunk_sectors; 4497 conf->level = mddev->new_level; 4498 if (conf->level == 6) 4499 conf->max_degraded = 2; 4500 else 4501 conf->max_degraded = 1; 4502 conf->algorithm = mddev->new_layout; 4503 conf->max_nr_stripes = NR_STRIPES; 4504 conf->reshape_progress = mddev->reshape_position; 4505 if (conf->reshape_progress != MaxSector) { 4506 conf->prev_chunk_sectors = mddev->chunk_sectors; 4507 conf->prev_algo = mddev->layout; 4508 } 4509 4510 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 4511 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; 4512 if (grow_stripes(conf, conf->max_nr_stripes)) { 4513 printk(KERN_ERR 4514 "md/raid:%s: couldn't allocate %dkB for buffers\n", 4515 mdname(mddev), memory); 4516 goto abort; 4517 } else 4518 printk(KERN_INFO "md/raid:%s: allocated %dkB\n", 4519 mdname(mddev), memory); 4520 4521 conf->thread = md_register_thread(raid5d, mddev, NULL); 4522 if (!conf->thread) { 4523 printk(KERN_ERR 4524 "md/raid:%s: couldn't allocate thread.\n", 4525 mdname(mddev)); 4526 goto abort; 4527 } 4528 4529 return conf; 4530 4531 abort: 4532 if (conf) { 4533 free_conf(conf); 4534 return ERR_PTR(-EIO); 4535 } else 4536 return ERR_PTR(-ENOMEM); 4537} 4538 4539 4540static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) 4541{ 4542 switch (algo) { 4543 case ALGORITHM_PARITY_0: 4544 if (raid_disk < max_degraded) 4545 return 1; 4546 break; 4547 case ALGORITHM_PARITY_N: 4548 if (raid_disk >= raid_disks - max_degraded) 4549 return 1; 4550 break; 4551 case ALGORITHM_PARITY_0_6: 4552 if (raid_disk == 0 || 4553 raid_disk == raid_disks - 1) 4554 return 1; 4555 break; 4556 case ALGORITHM_LEFT_ASYMMETRIC_6: 4557 case ALGORITHM_RIGHT_ASYMMETRIC_6: 4558 case ALGORITHM_LEFT_SYMMETRIC_6: 4559 case ALGORITHM_RIGHT_SYMMETRIC_6: 4560 if (raid_disk == raid_disks - 1) 4561 return 1; 4562 } 4563 return 0; 4564} 4565 4566static int run(mddev_t *mddev) 4567{ 4568 raid5_conf_t *conf; 4569 int working_disks = 0; 4570 int dirty_parity_disks = 0; 4571 mdk_rdev_t *rdev; 4572 sector_t reshape_offset = 0; 4573 4574 if (mddev->recovery_cp != MaxSector) 4575 printk(KERN_NOTICE "md/raid:%s: not clean" 4576 " -- starting background reconstruction\n", 4577 mdname(mddev)); 4578 if (mddev->reshape_position != MaxSector) { 4579 /* Check that we can continue the reshape. 4580 * Currently only disks can change, it must 4581 * increase, and we must be past the point where 4582 * a stripe over-writes itself 4583 */ 4584 sector_t here_new, here_old; 4585 int old_disks; 4586 int max_degraded = (mddev->level == 6 ? 2 : 1); 4587 4588 if (mddev->new_level != mddev->level) { 4589 printk(KERN_ERR "md/raid:%s: unsupported reshape " 4590 "required - aborting.\n", 4591 mdname(mddev)); 4592 return -EINVAL; 4593 } 4594 old_disks = mddev->raid_disks - mddev->delta_disks; 4595 /* reshape_position must be on a new-stripe boundary, and one 4596 * further up in new geometry must map after here in old 4597 * geometry. 4598 */ 4599 here_new = mddev->reshape_position; 4600 if (sector_div(here_new, mddev->new_chunk_sectors * 4601 (mddev->raid_disks - max_degraded))) { 4602 printk(KERN_ERR "md/raid:%s: reshape_position not " 4603 "on a stripe boundary\n", mdname(mddev)); 4604 return -EINVAL; 4605 } 4606 reshape_offset = here_new * mddev->new_chunk_sectors; 4607 /* here_new is the stripe we will write to */ 4608 here_old = mddev->reshape_position; 4609 sector_div(here_old, mddev->chunk_sectors * 4610 (old_disks-max_degraded)); 4611 /* here_old is the first stripe that we might need to read 4612 * from */ 4613 if (mddev->delta_disks == 0) { 4614 /* We cannot be sure it is safe to start an in-place 4615 * reshape. It is only safe if user-space if monitoring 4616 * and taking constant backups. 4617 * mdadm always starts a situation like this in 4618 * readonly mode so it can take control before 4619 * allowing any writes. So just check for that. 4620 */ 4621 if ((here_new * mddev->new_chunk_sectors != 4622 here_old * mddev->chunk_sectors) || 4623 mddev->ro == 0) { 4624 printk(KERN_ERR "md/raid:%s: in-place reshape must be started" 4625 " in read-only mode - aborting\n", 4626 mdname(mddev)); 4627 return -EINVAL; 4628 } 4629 } else if (mddev->delta_disks < 0 4630 ? (here_new * mddev->new_chunk_sectors <= 4631 here_old * mddev->chunk_sectors) 4632 : (here_new * mddev->new_chunk_sectors >= 4633 here_old * mddev->chunk_sectors)) { 4634 /* Reading from the same stripe as writing to - bad */ 4635 printk(KERN_ERR "md/raid:%s: reshape_position too early for " 4636 "auto-recovery - aborting.\n", 4637 mdname(mddev)); 4638 return -EINVAL; 4639 } 4640 printk(KERN_INFO "md/raid:%s: reshape will continue\n", 4641 mdname(mddev)); 4642 /* OK, we should be able to continue; */ 4643 } else { 4644 BUG_ON(mddev->level != mddev->new_level); 4645 BUG_ON(mddev->layout != mddev->new_layout); 4646 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); 4647 BUG_ON(mddev->delta_disks != 0); 4648 } 4649 4650 if (mddev->private == NULL) 4651 conf = setup_conf(mddev); 4652 else 4653 conf = mddev->private; 4654 4655 if (IS_ERR(conf)) 4656 return PTR_ERR(conf); 4657 4658 mddev->thread = conf->thread; 4659 conf->thread = NULL; 4660 mddev->private = conf; 4661 4662 /* 4663 * 0 for a fully functional array, 1 or 2 for a degraded array. 4664 */ 4665 list_for_each_entry(rdev, &mddev->disks, same_set) { 4666 if (rdev->raid_disk < 0) 4667 continue; 4668 if (test_bit(In_sync, &rdev->flags)) { 4669 working_disks++; 4670 continue; 4671 } 4672 /* This disc is not fully in-sync. However if it 4673 * just stored parity (beyond the recovery_offset), 4674 * when we don't need to be concerned about the 4675 * array being dirty. 4676 * When reshape goes 'backwards', we never have 4677 * partially completed devices, so we only need 4678 * to worry about reshape going forwards. 4679 */ 4680 /* Hack because v0.91 doesn't store recovery_offset properly. */ 4681 if (mddev->major_version == 0 && 4682 mddev->minor_version > 90) 4683 rdev->recovery_offset = reshape_offset; 4684 4685 if (rdev->recovery_offset < reshape_offset) { 4686 /* We need to check old and new layout */ 4687 if (!only_parity(rdev->raid_disk, 4688 conf->algorithm, 4689 conf->raid_disks, 4690 conf->max_degraded)) 4691 continue; 4692 } 4693 if (!only_parity(rdev->raid_disk, 4694 conf->prev_algo, 4695 conf->previous_raid_disks, 4696 conf->max_degraded)) 4697 continue; 4698 dirty_parity_disks++; 4699 } 4700 4701 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks) 4702 - working_disks); 4703 4704 if (has_failed(conf)) { 4705 printk(KERN_ERR "md/raid:%s: not enough operational devices" 4706 " (%d/%d failed)\n", 4707 mdname(mddev), mddev->degraded, conf->raid_disks); 4708 goto abort; 4709 } 4710 4711 /* device size must be a multiple of chunk size */ 4712 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); 4713 mddev->resync_max_sectors = mddev->dev_sectors; 4714 4715 if (mddev->degraded > dirty_parity_disks && 4716 mddev->recovery_cp != MaxSector) { 4717 if (mddev->ok_start_degraded) 4718 printk(KERN_WARNING 4719 "md/raid:%s: starting dirty degraded array" 4720 " - data corruption possible.\n", 4721 mdname(mddev)); 4722 else { 4723 printk(KERN_ERR 4724 "md/raid:%s: cannot start dirty degraded array.\n", 4725 mdname(mddev)); 4726 goto abort; 4727 } 4728 } 4729 4730 if (mddev->degraded == 0) 4731 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d" 4732 " devices, algorithm %d\n", mdname(mddev), conf->level, 4733 mddev->raid_disks-mddev->degraded, mddev->raid_disks, 4734 mddev->new_layout); 4735 else 4736 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d" 4737 " out of %d devices, algorithm %d\n", 4738 mdname(mddev), conf->level, 4739 mddev->raid_disks - mddev->degraded, 4740 mddev->raid_disks, mddev->new_layout); 4741 4742 print_raid5_conf(conf); 4743 4744 if (conf->reshape_progress != MaxSector) { 4745 conf->reshape_safe = conf->reshape_progress; 4746 atomic_set(&conf->reshape_stripes, 0); 4747 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 4748 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 4749 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 4750 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 4751 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 4752 "reshape"); 4753 } 4754 4755 4756 /* Ok, everything is just fine now */ 4757 if (mddev->to_remove == &raid5_attrs_group) 4758 mddev->to_remove = NULL; 4759 else if (mddev->kobj.sd && 4760 sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) 4761 printk(KERN_WARNING 4762 "raid5: failed to create sysfs attributes for %s\n", 4763 mdname(mddev)); 4764 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 4765 4766 if (mddev->queue) { 4767 int chunk_size; 4768 /* read-ahead size must cover two whole stripes, which 4769 * is 2 * (datadisks) * chunksize where 'n' is the 4770 * number of raid devices 4771 */ 4772 int data_disks = conf->previous_raid_disks - conf->max_degraded; 4773 int stripe = data_disks * 4774 ((mddev->chunk_sectors << 9) / PAGE_SIZE); 4775 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 4776 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 4777 4778 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); 4779 4780 mddev->queue->backing_dev_info.congested_data = mddev; 4781 mddev->queue->backing_dev_info.congested_fn = raid5_congested; 4782 4783 chunk_size = mddev->chunk_sectors << 9; 4784 blk_queue_io_min(mddev->queue, chunk_size); 4785 blk_queue_io_opt(mddev->queue, chunk_size * 4786 (conf->raid_disks - conf->max_degraded)); 4787 4788 list_for_each_entry(rdev, &mddev->disks, same_set) 4789 disk_stack_limits(mddev->gendisk, rdev->bdev, 4790 rdev->data_offset << 9); 4791 } 4792 4793 return 0; 4794abort: 4795 md_unregister_thread(mddev->thread); 4796 mddev->thread = NULL; 4797 if (conf) { 4798 print_raid5_conf(conf); 4799 free_conf(conf); 4800 } 4801 mddev->private = NULL; 4802 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev)); 4803 return -EIO; 4804} 4805 4806static int stop(mddev_t *mddev) 4807{ 4808 raid5_conf_t *conf = mddev->private; 4809 4810 md_unregister_thread(mddev->thread); 4811 mddev->thread = NULL; 4812 if (mddev->queue) 4813 mddev->queue->backing_dev_info.congested_fn = NULL; 4814 free_conf(conf); 4815 mddev->private = NULL; 4816 mddev->to_remove = &raid5_attrs_group; 4817 return 0; 4818} 4819 4820#ifdef DEBUG 4821static void print_sh(struct seq_file *seq, struct stripe_head *sh) 4822{ 4823 int i; 4824 4825 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", 4826 (unsigned long long)sh->sector, sh->pd_idx, sh->state); 4827 seq_printf(seq, "sh %llu, count %d.\n", 4828 (unsigned long long)sh->sector, atomic_read(&sh->count)); 4829 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); 4830 for (i = 0; i < sh->disks; i++) { 4831 seq_printf(seq, "(cache%d: %p %ld) ", 4832 i, sh->dev[i].page, sh->dev[i].flags); 4833 } 4834 seq_printf(seq, "\n"); 4835} 4836 4837static void printall(struct seq_file *seq, raid5_conf_t *conf) 4838{ 4839 struct stripe_head *sh; 4840 struct hlist_node *hn; 4841 int i; 4842 4843 spin_lock_irq(&conf->device_lock); 4844 for (i = 0; i < NR_HASH; i++) { 4845 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { 4846 if (sh->raid_conf != conf) 4847 continue; 4848 print_sh(seq, sh); 4849 } 4850 } 4851 spin_unlock_irq(&conf->device_lock); 4852} 4853#endif 4854 4855static void status(struct seq_file *seq, mddev_t *mddev) 4856{ 4857 raid5_conf_t *conf = mddev->private; 4858 int i; 4859 4860 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, 4861 mddev->chunk_sectors / 2, mddev->layout); 4862 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); 4863 for (i = 0; i < conf->raid_disks; i++) 4864 seq_printf (seq, "%s", 4865 conf->disks[i].rdev && 4866 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 4867 seq_printf (seq, "]"); 4868#ifdef DEBUG 4869 seq_printf (seq, "\n"); 4870 printall(seq, conf); 4871#endif 4872} 4873 4874static void print_raid5_conf (raid5_conf_t *conf) 4875{ 4876 int i; 4877 struct disk_info *tmp; 4878 4879 printk(KERN_DEBUG "RAID conf printout:\n"); 4880 if (!conf) { 4881 printk("(conf==NULL)\n"); 4882 return; 4883 } 4884 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level, 4885 conf->raid_disks, 4886 conf->raid_disks - conf->mddev->degraded); 4887 4888 for (i = 0; i < conf->raid_disks; i++) { 4889 char b[BDEVNAME_SIZE]; 4890 tmp = conf->disks + i; 4891 if (tmp->rdev) 4892 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n", 4893 i, !test_bit(Faulty, &tmp->rdev->flags), 4894 bdevname(tmp->rdev->bdev, b)); 4895 } 4896} 4897 4898static int raid5_spare_active(mddev_t *mddev) 4899{ 4900 int i; 4901 raid5_conf_t *conf = mddev->private; 4902 struct disk_info *tmp; 4903 int count = 0; 4904 unsigned long flags; 4905 4906 for (i = 0; i < conf->raid_disks; i++) { 4907 tmp = conf->disks + i; 4908 if (tmp->rdev 4909 && tmp->rdev->recovery_offset == MaxSector 4910 && !test_bit(Faulty, &tmp->rdev->flags) 4911 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { 4912 count++; 4913 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); 4914 } 4915 } 4916 spin_lock_irqsave(&conf->device_lock, flags); 4917 mddev->degraded -= count; 4918 spin_unlock_irqrestore(&conf->device_lock, flags); 4919 print_raid5_conf(conf); 4920 return count; 4921} 4922 4923static int raid5_remove_disk(mddev_t *mddev, int number) 4924{ 4925 raid5_conf_t *conf = mddev->private; 4926 int err = 0; 4927 mdk_rdev_t *rdev; 4928 struct disk_info *p = conf->disks + number; 4929 4930 print_raid5_conf(conf); 4931 rdev = p->rdev; 4932 if (rdev) { 4933 if (number >= conf->raid_disks && 4934 conf->reshape_progress == MaxSector) 4935 clear_bit(In_sync, &rdev->flags); 4936 4937 if (test_bit(In_sync, &rdev->flags) || 4938 atomic_read(&rdev->nr_pending)) { 4939 err = -EBUSY; 4940 goto abort; 4941 } 4942 /* Only remove non-faulty devices if recovery 4943 * isn't possible. 4944 */ 4945 if (!test_bit(Faulty, &rdev->flags) && 4946 !has_failed(conf) && 4947 number < conf->raid_disks) { 4948 err = -EBUSY; 4949 goto abort; 4950 } 4951 p->rdev = NULL; 4952 synchronize_rcu(); 4953 if (atomic_read(&rdev->nr_pending)) { 4954 /* lost the race, try later */ 4955 err = -EBUSY; 4956 p->rdev = rdev; 4957 } 4958 } 4959abort: 4960 4961 print_raid5_conf(conf); 4962 return err; 4963} 4964 4965static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) 4966{ 4967 raid5_conf_t *conf = mddev->private; 4968 int err = -EEXIST; 4969 int disk; 4970 struct disk_info *p; 4971 int first = 0; 4972 int last = conf->raid_disks - 1; 4973 4974 if (has_failed(conf)) 4975 /* no point adding a device */ 4976 return -EINVAL; 4977 4978 if (rdev->raid_disk >= 0) 4979 first = last = rdev->raid_disk; 4980 4981 /* 4982 * find the disk ... but prefer rdev->saved_raid_disk 4983 * if possible. 4984 */ 4985 if (rdev->saved_raid_disk >= 0 && 4986 rdev->saved_raid_disk >= first && 4987 conf->disks[rdev->saved_raid_disk].rdev == NULL) 4988 disk = rdev->saved_raid_disk; 4989 else 4990 disk = first; 4991 for ( ; disk <= last ; disk++) 4992 if ((p=conf->disks + disk)->rdev == NULL) { 4993 clear_bit(In_sync, &rdev->flags); 4994 rdev->raid_disk = disk; 4995 err = 0; 4996 if (rdev->saved_raid_disk != disk) 4997 conf->fullsync = 1; 4998 rcu_assign_pointer(p->rdev, rdev); 4999 break; 5000 } 5001 print_raid5_conf(conf); 5002 return err; 5003} 5004 5005static int raid5_resize(mddev_t *mddev, sector_t sectors) 5006{ 5007 /* no resync is happening, and there is enough space 5008 * on all devices, so we can resize. 5009 * We need to make sure resync covers any new space. 5010 * If the array is shrinking we should possibly wait until 5011 * any io in the removed space completes, but it hardly seems 5012 * worth it. 5013 */ 5014 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 5015 md_set_array_sectors(mddev, raid5_size(mddev, sectors, 5016 mddev->raid_disks)); 5017 if (mddev->array_sectors > 5018 raid5_size(mddev, sectors, mddev->raid_disks)) 5019 return -EINVAL; 5020 set_capacity(mddev->gendisk, mddev->array_sectors); 5021 revalidate_disk(mddev->gendisk); 5022 if (sectors > mddev->dev_sectors && 5023 mddev->recovery_cp > mddev->dev_sectors) { 5024 mddev->recovery_cp = mddev->dev_sectors; 5025 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 5026 } 5027 mddev->dev_sectors = sectors; 5028 mddev->resync_max_sectors = sectors; 5029 return 0; 5030} 5031 5032static int check_stripe_cache(mddev_t *mddev) 5033{ 5034 /* Can only proceed if there are plenty of stripe_heads. 5035 * We need a minimum of one full stripe,, and for sensible progress 5036 * it is best to have about 4 times that. 5037 * If we require 4 times, then the default 256 4K stripe_heads will 5038 * allow for chunk sizes up to 256K, which is probably OK. 5039 * If the chunk size is greater, user-space should request more 5040 * stripe_heads first. 5041 */ 5042 raid5_conf_t *conf = mddev->private; 5043 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 5044 > conf->max_nr_stripes || 5045 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 5046 > conf->max_nr_stripes) { 5047 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n", 5048 mdname(mddev), 5049 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) 5050 / STRIPE_SIZE)*4); 5051 return 0; 5052 } 5053 return 1; 5054} 5055 5056static int check_reshape(mddev_t *mddev) 5057{ 5058 raid5_conf_t *conf = mddev->private; 5059 5060 if (mddev->delta_disks == 0 && 5061 mddev->new_layout == mddev->layout && 5062 mddev->new_chunk_sectors == mddev->chunk_sectors) 5063 return 0; /* nothing to do */ 5064 if (mddev->bitmap) 5065 /* Cannot grow a bitmap yet */ 5066 return -EBUSY; 5067 if (has_failed(conf)) 5068 return -EINVAL; 5069 if (mddev->delta_disks < 0) { 5070 /* We might be able to shrink, but the devices must 5071 * be made bigger first. 5072 * For raid6, 4 is the minimum size. 5073 * Otherwise 2 is the minimum 5074 */ 5075 int min = 2; 5076 if (mddev->level == 6) 5077 min = 4; 5078 if (mddev->raid_disks + mddev->delta_disks < min) 5079 return -EINVAL; 5080 } 5081 5082 if (!check_stripe_cache(mddev)) 5083 return -ENOSPC; 5084 5085 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); 5086} 5087 5088static int raid5_start_reshape(mddev_t *mddev) 5089{ 5090 raid5_conf_t *conf = mddev->private; 5091 mdk_rdev_t *rdev; 5092 int spares = 0; 5093 unsigned long flags; 5094 5095 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 5096 return -EBUSY; 5097 5098 if (!check_stripe_cache(mddev)) 5099 return -ENOSPC; 5100 5101 list_for_each_entry(rdev, &mddev->disks, same_set) 5102 if (!test_bit(In_sync, &rdev->flags) 5103 && !test_bit(Faulty, &rdev->flags)) 5104 spares++; 5105 5106 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) 5107 /* Not enough devices even to make a degraded array 5108 * of that size 5109 */ 5110 return -EINVAL; 5111 5112 /* Refuse to reduce size of the array. Any reductions in 5113 * array size must be through explicit setting of array_size 5114 * attribute. 5115 */ 5116 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) 5117 < mddev->array_sectors) { 5118 printk(KERN_ERR "md/raid:%s: array size must be reduced " 5119 "before number of disks\n", mdname(mddev)); 5120 return -EINVAL; 5121 } 5122 5123 atomic_set(&conf->reshape_stripes, 0); 5124 spin_lock_irq(&conf->device_lock); 5125 conf->previous_raid_disks = conf->raid_disks; 5126 conf->raid_disks += mddev->delta_disks; 5127 conf->prev_chunk_sectors = conf->chunk_sectors; 5128 conf->chunk_sectors = mddev->new_chunk_sectors; 5129 conf->prev_algo = conf->algorithm; 5130 conf->algorithm = mddev->new_layout; 5131 if (mddev->delta_disks < 0) 5132 conf->reshape_progress = raid5_size(mddev, 0, 0); 5133 else 5134 conf->reshape_progress = 0; 5135 conf->reshape_safe = conf->reshape_progress; 5136 conf->generation++; 5137 spin_unlock_irq(&conf->device_lock); 5138 5139 /* Add some new drives, as many as will fit. 5140 * We know there are enough to make the newly sized array work. 5141 * Don't add devices if we are reducing the number of 5142 * devices in the array. This is because it is not possible 5143 * to correctly record the "partially reconstructed" state of 5144 * such devices during the reshape and confusion could result. 5145 */ 5146 if (mddev->delta_disks >= 0) { 5147 int added_devices = 0; 5148 list_for_each_entry(rdev, &mddev->disks, same_set) 5149 if (rdev->raid_disk < 0 && 5150 !test_bit(Faulty, &rdev->flags)) { 5151 if (raid5_add_disk(mddev, rdev) == 0) { 5152 char nm[20]; 5153 if (rdev->raid_disk 5154 >= conf->previous_raid_disks) { 5155 set_bit(In_sync, &rdev->flags); 5156 added_devices++; 5157 } else 5158 rdev->recovery_offset = 0; 5159 sprintf(nm, "rd%d", rdev->raid_disk); 5160 if (sysfs_create_link(&mddev->kobj, 5161 &rdev->kobj, nm)) 5162 /* Failure here is OK */; 5163 } 5164 } else if (rdev->raid_disk >= conf->previous_raid_disks 5165 && !test_bit(Faulty, &rdev->flags)) { 5166 /* This is a spare that was manually added */ 5167 set_bit(In_sync, &rdev->flags); 5168 added_devices++; 5169 } 5170 5171 /* When a reshape changes the number of devices, 5172 * ->degraded is measured against the larger of the 5173 * pre and post number of devices. 5174 */ 5175 spin_lock_irqsave(&conf->device_lock, flags); 5176 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks) 5177 - added_devices; 5178 spin_unlock_irqrestore(&conf->device_lock, flags); 5179 } 5180 mddev->raid_disks = conf->raid_disks; 5181 mddev->reshape_position = conf->reshape_progress; 5182 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5183 5184 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 5185 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 5186 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 5187 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 5188 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 5189 "reshape"); 5190 if (!mddev->sync_thread) { 5191 mddev->recovery = 0; 5192 spin_lock_irq(&conf->device_lock); 5193 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; 5194 conf->reshape_progress = MaxSector; 5195 spin_unlock_irq(&conf->device_lock); 5196 return -EAGAIN; 5197 } 5198 conf->reshape_checkpoint = jiffies; 5199 md_wakeup_thread(mddev->sync_thread); 5200 md_new_event(mddev); 5201 return 0; 5202} 5203 5204/* This is called from the reshape thread and should make any 5205 * changes needed in 'conf' 5206 */ 5207static void end_reshape(raid5_conf_t *conf) 5208{ 5209 5210 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { 5211 5212 spin_lock_irq(&conf->device_lock); 5213 conf->previous_raid_disks = conf->raid_disks; 5214 conf->reshape_progress = MaxSector; 5215 spin_unlock_irq(&conf->device_lock); 5216 wake_up(&conf->wait_for_overlap); 5217 5218 /* read-ahead size must cover two whole stripes, which is 5219 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 5220 */ 5221 if (conf->mddev->queue) { 5222 int data_disks = conf->raid_disks - conf->max_degraded; 5223 int stripe = data_disks * ((conf->chunk_sectors << 9) 5224 / PAGE_SIZE); 5225 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 5226 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 5227 } 5228 } 5229} 5230 5231/* This is called from the raid5d thread with mddev_lock held. 5232 * It makes config changes to the device. 5233 */ 5234static void raid5_finish_reshape(mddev_t *mddev) 5235{ 5236 raid5_conf_t *conf = mddev->private; 5237 5238 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { 5239 5240 if (mddev->delta_disks > 0) { 5241 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 5242 set_capacity(mddev->gendisk, mddev->array_sectors); 5243 revalidate_disk(mddev->gendisk); 5244 } else { 5245 int d; 5246 mddev->degraded = conf->raid_disks; 5247 for (d = 0; d < conf->raid_disks ; d++) 5248 if (conf->disks[d].rdev && 5249 test_bit(In_sync, 5250 &conf->disks[d].rdev->flags)) 5251 mddev->degraded--; 5252 for (d = conf->raid_disks ; 5253 d < conf->raid_disks - mddev->delta_disks; 5254 d++) { 5255 mdk_rdev_t *rdev = conf->disks[d].rdev; 5256 if (rdev && raid5_remove_disk(mddev, d) == 0) { 5257 char nm[20]; 5258 sprintf(nm, "rd%d", rdev->raid_disk); 5259 sysfs_remove_link(&mddev->kobj, nm); 5260 rdev->raid_disk = -1; 5261 } 5262 } 5263 } 5264 mddev->layout = conf->algorithm; 5265 mddev->chunk_sectors = conf->chunk_sectors; 5266 mddev->reshape_position = MaxSector; 5267 mddev->delta_disks = 0; 5268 } 5269} 5270 5271static void raid5_quiesce(mddev_t *mddev, int state) 5272{ 5273 raid5_conf_t *conf = mddev->private; 5274 5275 switch(state) { 5276 case 2: /* resume for a suspend */ 5277 wake_up(&conf->wait_for_overlap); 5278 break; 5279 5280 case 1: /* stop all writes */ 5281 spin_lock_irq(&conf->device_lock); 5282 /* '2' tells resync/reshape to pause so that all 5283 * active stripes can drain 5284 */ 5285 conf->quiesce = 2; 5286 wait_event_lock_irq(conf->wait_for_stripe, 5287 atomic_read(&conf->active_stripes) == 0 && 5288 atomic_read(&conf->active_aligned_reads) == 0, 5289 conf->device_lock, /* nothing */); 5290 conf->quiesce = 1; 5291 spin_unlock_irq(&conf->device_lock); 5292 /* allow reshape to continue */ 5293 wake_up(&conf->wait_for_overlap); 5294 break; 5295 5296 case 0: /* re-enable writes */ 5297 spin_lock_irq(&conf->device_lock); 5298 conf->quiesce = 0; 5299 wake_up(&conf->wait_for_stripe); 5300 wake_up(&conf->wait_for_overlap); 5301 spin_unlock_irq(&conf->device_lock); 5302 break; 5303 } 5304} 5305 5306 5307static void *raid45_takeover_raid0(mddev_t *mddev, int level) 5308{ 5309 struct raid0_private_data *raid0_priv = mddev->private; 5310 sector_t sectors; 5311 5312 /* for raid0 takeover only one zone is supported */ 5313 if (raid0_priv->nr_strip_zones > 1) { 5314 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n", 5315 mdname(mddev)); 5316 return ERR_PTR(-EINVAL); 5317 } 5318 5319 sectors = raid0_priv->strip_zone[0].zone_end; 5320 sector_div(sectors, raid0_priv->strip_zone[0].nb_dev); 5321 mddev->dev_sectors = sectors; 5322 mddev->new_level = level; 5323 mddev->new_layout = ALGORITHM_PARITY_N; 5324 mddev->new_chunk_sectors = mddev->chunk_sectors; 5325 mddev->raid_disks += 1; 5326 mddev->delta_disks = 1; 5327 /* make sure it will be not marked as dirty */ 5328 mddev->recovery_cp = MaxSector; 5329 5330 return setup_conf(mddev); 5331} 5332 5333 5334static void *raid5_takeover_raid1(mddev_t *mddev) 5335{ 5336 int chunksect; 5337 5338 if (mddev->raid_disks != 2 || 5339 mddev->degraded > 1) 5340 return ERR_PTR(-EINVAL); 5341 5342 /* Should check if there are write-behind devices? */ 5343 5344 chunksect = 64*2; /* 64K by default */ 5345 5346 /* The array must be an exact multiple of chunksize */ 5347 while (chunksect && (mddev->array_sectors & (chunksect-1))) 5348 chunksect >>= 1; 5349 5350 if ((chunksect<<9) < STRIPE_SIZE) 5351 /* array size does not allow a suitable chunk size */ 5352 return ERR_PTR(-EINVAL); 5353 5354 mddev->new_level = 5; 5355 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; 5356 mddev->new_chunk_sectors = chunksect; 5357 5358 return setup_conf(mddev); 5359} 5360 5361static void *raid5_takeover_raid6(mddev_t *mddev) 5362{ 5363 int new_layout; 5364 5365 switch (mddev->layout) { 5366 case ALGORITHM_LEFT_ASYMMETRIC_6: 5367 new_layout = ALGORITHM_LEFT_ASYMMETRIC; 5368 break; 5369 case ALGORITHM_RIGHT_ASYMMETRIC_6: 5370 new_layout = ALGORITHM_RIGHT_ASYMMETRIC; 5371 break; 5372 case ALGORITHM_LEFT_SYMMETRIC_6: 5373 new_layout = ALGORITHM_LEFT_SYMMETRIC; 5374 break; 5375 case ALGORITHM_RIGHT_SYMMETRIC_6: 5376 new_layout = ALGORITHM_RIGHT_SYMMETRIC; 5377 break; 5378 case ALGORITHM_PARITY_0_6: 5379 new_layout = ALGORITHM_PARITY_0; 5380 break; 5381 case ALGORITHM_PARITY_N: 5382 new_layout = ALGORITHM_PARITY_N; 5383 break; 5384 default: 5385 return ERR_PTR(-EINVAL); 5386 } 5387 mddev->new_level = 5; 5388 mddev->new_layout = new_layout; 5389 mddev->delta_disks = -1; 5390 mddev->raid_disks -= 1; 5391 return setup_conf(mddev); 5392} 5393 5394 5395static int raid5_check_reshape(mddev_t *mddev) 5396{ 5397 /* For a 2-drive array, the layout and chunk size can be changed 5398 * immediately as not restriping is needed. 5399 * For larger arrays we record the new value - after validation 5400 * to be used by a reshape pass. 5401 */ 5402 raid5_conf_t *conf = mddev->private; 5403 int new_chunk = mddev->new_chunk_sectors; 5404 5405 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) 5406 return -EINVAL; 5407 if (new_chunk > 0) { 5408 if (!is_power_of_2(new_chunk)) 5409 return -EINVAL; 5410 if (new_chunk < (PAGE_SIZE>>9)) 5411 return -EINVAL; 5412 if (mddev->array_sectors & (new_chunk-1)) 5413 /* not factor of array size */ 5414 return -EINVAL; 5415 } 5416 5417 /* They look valid */ 5418 5419 if (mddev->raid_disks == 2) { 5420 /* can make the change immediately */ 5421 if (mddev->new_layout >= 0) { 5422 conf->algorithm = mddev->new_layout; 5423 mddev->layout = mddev->new_layout; 5424 } 5425 if (new_chunk > 0) { 5426 conf->chunk_sectors = new_chunk ; 5427 mddev->chunk_sectors = new_chunk; 5428 } 5429 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5430 md_wakeup_thread(mddev->thread); 5431 } 5432 return check_reshape(mddev); 5433} 5434 5435static int raid6_check_reshape(mddev_t *mddev) 5436{ 5437 int new_chunk = mddev->new_chunk_sectors; 5438 5439 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) 5440 return -EINVAL; 5441 if (new_chunk > 0) { 5442 if (!is_power_of_2(new_chunk)) 5443 return -EINVAL; 5444 if (new_chunk < (PAGE_SIZE >> 9)) 5445 return -EINVAL; 5446 if (mddev->array_sectors & (new_chunk-1)) 5447 /* not factor of array size */ 5448 return -EINVAL; 5449 } 5450 5451 /* They look valid */ 5452 return check_reshape(mddev); 5453} 5454 5455static void *raid5_takeover(mddev_t *mddev) 5456{ 5457 /* raid5 can take over: 5458 * raid0 - if there is only one strip zone - make it a raid4 layout 5459 * raid1 - if there are two drives. We need to know the chunk size 5460 * raid4 - trivial - just use a raid4 layout. 5461 * raid6 - Providing it is a *_6 layout 5462 */ 5463 if (mddev->level == 0) 5464 return raid45_takeover_raid0(mddev, 5); 5465 if (mddev->level == 1) 5466 return raid5_takeover_raid1(mddev); 5467 if (mddev->level == 4) { 5468 mddev->new_layout = ALGORITHM_PARITY_N; 5469 mddev->new_level = 5; 5470 return setup_conf(mddev); 5471 } 5472 if (mddev->level == 6) 5473 return raid5_takeover_raid6(mddev); 5474 5475 return ERR_PTR(-EINVAL); 5476} 5477 5478static void *raid4_takeover(mddev_t *mddev) 5479{ 5480 /* raid4 can take over: 5481 * raid0 - if there is only one strip zone 5482 * raid5 - if layout is right 5483 */ 5484 if (mddev->level == 0) 5485 return raid45_takeover_raid0(mddev, 4); 5486 if (mddev->level == 5 && 5487 mddev->layout == ALGORITHM_PARITY_N) { 5488 mddev->new_layout = 0; 5489 mddev->new_level = 4; 5490 return setup_conf(mddev); 5491 } 5492 return ERR_PTR(-EINVAL); 5493} 5494 5495static struct mdk_personality raid5_personality; 5496 5497static void *raid6_takeover(mddev_t *mddev) 5498{ 5499 /* Currently can only take over a raid5. We map the 5500 * personality to an equivalent raid6 personality 5501 * with the Q block at the end. 5502 */ 5503 int new_layout; 5504 5505 if (mddev->pers != &raid5_personality) 5506 return ERR_PTR(-EINVAL); 5507 if (mddev->degraded > 1) 5508 return ERR_PTR(-EINVAL); 5509 if (mddev->raid_disks > 253) 5510 return ERR_PTR(-EINVAL); 5511 if (mddev->raid_disks < 3) 5512 return ERR_PTR(-EINVAL); 5513 5514 switch (mddev->layout) { 5515 case ALGORITHM_LEFT_ASYMMETRIC: 5516 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; 5517 break; 5518 case ALGORITHM_RIGHT_ASYMMETRIC: 5519 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; 5520 break; 5521 case ALGORITHM_LEFT_SYMMETRIC: 5522 new_layout = ALGORITHM_LEFT_SYMMETRIC_6; 5523 break; 5524 case ALGORITHM_RIGHT_SYMMETRIC: 5525 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; 5526 break; 5527 case ALGORITHM_PARITY_0: 5528 new_layout = ALGORITHM_PARITY_0_6; 5529 break; 5530 case ALGORITHM_PARITY_N: 5531 new_layout = ALGORITHM_PARITY_N; 5532 break; 5533 default: 5534 return ERR_PTR(-EINVAL); 5535 } 5536 mddev->new_level = 6; 5537 mddev->new_layout = new_layout; 5538 mddev->delta_disks = 1; 5539 mddev->raid_disks += 1; 5540 return setup_conf(mddev); 5541} 5542 5543 5544static struct mdk_personality raid6_personality = 5545{ 5546 .name = "raid6", 5547 .level = 6, 5548 .owner = THIS_MODULE, 5549 .make_request = make_request, 5550 .run = run, 5551 .stop = stop, 5552 .status = status, 5553 .error_handler = error, 5554 .hot_add_disk = raid5_add_disk, 5555 .hot_remove_disk= raid5_remove_disk, 5556 .spare_active = raid5_spare_active, 5557 .sync_request = sync_request, 5558 .resize = raid5_resize, 5559 .size = raid5_size, 5560 .check_reshape = raid6_check_reshape, 5561 .start_reshape = raid5_start_reshape, 5562 .finish_reshape = raid5_finish_reshape, 5563 .quiesce = raid5_quiesce, 5564 .takeover = raid6_takeover, 5565}; 5566static struct mdk_personality raid5_personality = 5567{ 5568 .name = "raid5", 5569 .level = 5, 5570 .owner = THIS_MODULE, 5571 .make_request = make_request, 5572 .run = run, 5573 .stop = stop, 5574 .status = status, 5575 .error_handler = error, 5576 .hot_add_disk = raid5_add_disk, 5577 .hot_remove_disk= raid5_remove_disk, 5578 .spare_active = raid5_spare_active, 5579 .sync_request = sync_request, 5580 .resize = raid5_resize, 5581 .size = raid5_size, 5582 .check_reshape = raid5_check_reshape, 5583 .start_reshape = raid5_start_reshape, 5584 .finish_reshape = raid5_finish_reshape, 5585 .quiesce = raid5_quiesce, 5586 .takeover = raid5_takeover, 5587}; 5588 5589static struct mdk_personality raid4_personality = 5590{ 5591 .name = "raid4", 5592 .level = 4, 5593 .owner = THIS_MODULE, 5594 .make_request = make_request, 5595 .run = run, 5596 .stop = stop, 5597 .status = status, 5598 .error_handler = error, 5599 .hot_add_disk = raid5_add_disk, 5600 .hot_remove_disk= raid5_remove_disk, 5601 .spare_active = raid5_spare_active, 5602 .sync_request = sync_request, 5603 .resize = raid5_resize, 5604 .size = raid5_size, 5605 .check_reshape = raid5_check_reshape, 5606 .start_reshape = raid5_start_reshape, 5607 .finish_reshape = raid5_finish_reshape, 5608 .quiesce = raid5_quiesce, 5609 .takeover = raid4_takeover, 5610}; 5611 5612static int __init raid5_init(void) 5613{ 5614 register_md_personality(&raid6_personality); 5615 register_md_personality(&raid5_personality); 5616 register_md_personality(&raid4_personality); 5617 return 0; 5618} 5619 5620static void raid5_exit(void) 5621{ 5622 unregister_md_personality(&raid6_personality); 5623 unregister_md_personality(&raid5_personality); 5624 unregister_md_personality(&raid4_personality); 5625} 5626 5627module_init(raid5_init); 5628module_exit(raid5_exit); 5629MODULE_LICENSE("GPL"); 5630MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD"); 5631MODULE_ALIAS("md-personality-4"); /* RAID5 */ 5632MODULE_ALIAS("md-raid5"); 5633MODULE_ALIAS("md-raid4"); 5634MODULE_ALIAS("md-level-5"); 5635MODULE_ALIAS("md-level-4"); 5636MODULE_ALIAS("md-personality-8"); /* RAID6 */ 5637MODULE_ALIAS("md-raid6"); 5638MODULE_ALIAS("md-level-6"); 5639 5640/* This used to be two separate modules, they were: */ 5641MODULE_ALIAS("raid5"); 5642MODULE_ALIAS("raid6"); 5643