1 /* 2 * raid5.c : Multiple Devices driver for Linux 3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman 4 * Copyright (C) 1999, 2000 Ingo Molnar 5 * Copyright (C) 2002, 2003 H. Peter Anvin 6 * 7 * RAID-4/5/6 management functions. 8 * Thanks to Penguin Computing for making the RAID-6 development possible 9 * by donating a test server! 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2, or (at your option) 14 * any later version. 15 * 16 * You should have received a copy of the GNU General Public License 17 * (for example /usr/src/linux/COPYING); if not, write to the Free 18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 /* 22 * BITMAP UNPLUGGING: 23 * 24 * The sequencing for updating the bitmap reliably is a little 25 * subtle (and I got it wrong the first time) so it deserves some 26 * explanation. 27 * 28 * We group bitmap updates into batches. Each batch has a number. 29 * We may write out several batches at once, but that isn't very important. 30 * conf->seq_write is the number of the last batch successfully written. 31 * conf->seq_flush is the number of the last batch that was closed to 32 * new additions. 33 * When we discover that we will need to write to any block in a stripe 34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq 35 * the number of the batch it will be in. This is seq_flush+1. 36 * When we are ready to do a write, if that batch hasn't been written yet, 37 * we plug the array and queue the stripe for later. 38 * When an unplug happens, we increment bm_flush, thus closing the current 39 * batch. 40 * When we notice that bm_flush > bm_write, we write out all pending updates 41 * to the bitmap, and advance bm_write to where bm_flush was. 42 * This may occasionally write a bit out twice, but is sure never to 43 * miss any bits. 44 */ 45 46 #include <linux/blkdev.h> 47 #include <linux/kthread.h> 48 #include <linux/raid/pq.h> 49 #include <linux/async_tx.h> 50 #include <linux/module.h> 51 #include <linux/async.h> 52 #include <linux/seq_file.h> 53 #include <linux/cpu.h> 54 #include <linux/slab.h> 55 #include <linux/ratelimit.h> 56 #include "md.h" 57 #include "raid5.h" 58 #include "raid0.h" 59 #include "bitmap.h" 60 61 /* 62 * Stripe cache 63 */ 64 65 #define NR_STRIPES 256 66 #define STRIPE_SIZE PAGE_SIZE 67 #define STRIPE_SHIFT (PAGE_SHIFT - 9) 68 #define STRIPE_SECTORS (STRIPE_SIZE>>9) 69 #define IO_THRESHOLD 1 70 #define BYPASS_THRESHOLD 1 71 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) 72 #define HASH_MASK (NR_HASH - 1) 73 74 static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect) 75 { 76 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK; 77 return &conf->stripe_hashtbl[hash]; 78 } 79 80 /* bio's attached to a stripe+device for I/O are linked together in bi_sector 81 * order without overlap. There may be several bio's per stripe+device, and 82 * a bio could span several devices. 83 * When walking this list for a particular stripe+device, we must never proceed 84 * beyond a bio that extends past this device, as the next bio might no longer 85 * be valid. 86 * This function is used to determine the 'next' bio in the list, given the sector 87 * of the current stripe+device 88 */ 89 static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector) 90 { 91 int sectors = bio->bi_size >> 9; 92 if (bio->bi_sector + sectors < sector + STRIPE_SECTORS) 93 return bio->bi_next; 94 else 95 return NULL; 96 } 97 98 /* 99 * We maintain a biased count of active stripes in the bottom 16 bits of 100 * bi_phys_segments, and a count of processed stripes in the upper 16 bits 101 */ 102 static inline int raid5_bi_phys_segments(struct bio *bio) 103 { 104 return bio->bi_phys_segments & 0xffff; 105 } 106 107 static inline int raid5_bi_hw_segments(struct bio *bio) 108 { 109 return (bio->bi_phys_segments >> 16) & 0xffff; 110 } 111 112 static inline int raid5_dec_bi_phys_segments(struct bio *bio) 113 { 114 --bio->bi_phys_segments; 115 return raid5_bi_phys_segments(bio); 116 } 117 118 static inline int raid5_dec_bi_hw_segments(struct bio *bio) 119 { 120 unsigned short val = raid5_bi_hw_segments(bio); 121 122 --val; 123 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); 124 return val; 125 } 126 127 static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) 128 { 129 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16); 130 } 131 132 /* Find first data disk in a raid6 stripe */ 133 static inline int raid6_d0(struct stripe_head *sh) 134 { 135 if (sh->ddf_layout) 136 /* ddf always start from first device */ 137 return 0; 138 /* md starts just after Q block */ 139 if (sh->qd_idx == sh->disks - 1) 140 return 0; 141 else 142 return sh->qd_idx + 1; 143 } 144 static inline int raid6_next_disk(int disk, int raid_disks) 145 { 146 disk++; 147 return (disk < raid_disks) ? disk : 0; 148 } 149 150 /* When walking through the disks in a raid5, starting at raid6_d0, 151 * We need to map each disk to a 'slot', where the data disks are slot 152 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk 153 * is raid_disks-1. This help does that mapping. 154 */ 155 static int raid6_idx_to_slot(int idx, struct stripe_head *sh, 156 int *count, int syndrome_disks) 157 { 158 int slot = *count; 159 160 if (sh->ddf_layout) 161 (*count)++; 162 if (idx == sh->pd_idx) 163 return syndrome_disks; 164 if (idx == sh->qd_idx) 165 return syndrome_disks + 1; 166 if (!sh->ddf_layout) 167 (*count)++; 168 return slot; 169 } 170 171 static void return_io(struct bio *return_bi) 172 { 173 struct bio *bi = return_bi; 174 while (bi) { 175 176 return_bi = bi->bi_next; 177 bi->bi_next = NULL; 178 bi->bi_size = 0; 179 bio_endio(bi, 0); 180 bi = return_bi; 181 } 182 } 183 184 static void print_raid5_conf (struct r5conf *conf); 185 186 static int stripe_operations_active(struct stripe_head *sh) 187 { 188 return sh->check_state || sh->reconstruct_state || 189 test_bit(STRIPE_BIOFILL_RUN, &sh->state) || 190 test_bit(STRIPE_COMPUTE_RUN, &sh->state); 191 } 192 193 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh) 194 { 195 if (atomic_dec_and_test(&sh->count)) { 196 BUG_ON(!list_empty(&sh->lru)); 197 BUG_ON(atomic_read(&conf->active_stripes)==0); 198 if (test_bit(STRIPE_HANDLE, &sh->state)) { 199 if (test_bit(STRIPE_DELAYED, &sh->state)) 200 list_add_tail(&sh->lru, &conf->delayed_list); 201 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && 202 sh->bm_seq - conf->seq_write > 0) 203 list_add_tail(&sh->lru, &conf->bitmap_list); 204 else { 205 clear_bit(STRIPE_BIT_DELAY, &sh->state); 206 list_add_tail(&sh->lru, &conf->handle_list); 207 } 208 md_wakeup_thread(conf->mddev->thread); 209 } else { 210 BUG_ON(stripe_operations_active(sh)); 211 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 212 if (atomic_dec_return(&conf->preread_active_stripes) 213 < IO_THRESHOLD) 214 md_wakeup_thread(conf->mddev->thread); 215 atomic_dec(&conf->active_stripes); 216 if (!test_bit(STRIPE_EXPANDING, &sh->state)) { 217 list_add_tail(&sh->lru, &conf->inactive_list); 218 wake_up(&conf->wait_for_stripe); 219 if (conf->retry_read_aligned) 220 md_wakeup_thread(conf->mddev->thread); 221 } 222 } 223 } 224 } 225 226 static void release_stripe(struct stripe_head *sh) 227 { 228 struct r5conf *conf = sh->raid_conf; 229 unsigned long flags; 230 231 spin_lock_irqsave(&conf->device_lock, flags); 232 __release_stripe(conf, sh); 233 spin_unlock_irqrestore(&conf->device_lock, flags); 234 } 235 236 static inline void remove_hash(struct stripe_head *sh) 237 { 238 pr_debug("remove_hash(), stripe %llu\n", 239 (unsigned long long)sh->sector); 240 241 hlist_del_init(&sh->hash); 242 } 243 244 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh) 245 { 246 struct hlist_head *hp = stripe_hash(conf, sh->sector); 247 248 pr_debug("insert_hash(), stripe %llu\n", 249 (unsigned long long)sh->sector); 250 251 hlist_add_head(&sh->hash, hp); 252 } 253 254 255 /* find an idle stripe, make sure it is unhashed, and return it. */ 256 static struct stripe_head *get_free_stripe(struct r5conf *conf) 257 { 258 struct stripe_head *sh = NULL; 259 struct list_head *first; 260 261 if (list_empty(&conf->inactive_list)) 262 goto out; 263 first = conf->inactive_list.next; 264 sh = list_entry(first, struct stripe_head, lru); 265 list_del_init(first); 266 remove_hash(sh); 267 atomic_inc(&conf->active_stripes); 268 out: 269 return sh; 270 } 271 272 static void shrink_buffers(struct stripe_head *sh) 273 { 274 struct page *p; 275 int i; 276 int num = sh->raid_conf->pool_size; 277 278 for (i = 0; i < num ; i++) { 279 p = sh->dev[i].page; 280 if (!p) 281 continue; 282 sh->dev[i].page = NULL; 283 put_page(p); 284 } 285 } 286 287 static int grow_buffers(struct stripe_head *sh) 288 { 289 int i; 290 int num = sh->raid_conf->pool_size; 291 292 for (i = 0; i < num; i++) { 293 struct page *page; 294 295 if (!(page = alloc_page(GFP_KERNEL))) { 296 return 1; 297 } 298 sh->dev[i].page = page; 299 } 300 return 0; 301 } 302 303 static void raid5_build_block(struct stripe_head *sh, int i, int previous); 304 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, 305 struct stripe_head *sh); 306 307 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) 308 { 309 struct r5conf *conf = sh->raid_conf; 310 int i; 311 312 BUG_ON(atomic_read(&sh->count) != 0); 313 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); 314 BUG_ON(stripe_operations_active(sh)); 315 316 pr_debug("init_stripe called, stripe %llu\n", 317 (unsigned long long)sh->sector); 318 319 remove_hash(sh); 320 321 sh->generation = conf->generation - previous; 322 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; 323 sh->sector = sector; 324 stripe_set_idx(sector, conf, previous, sh); 325 sh->state = 0; 326 327 328 for (i = sh->disks; i--; ) { 329 struct r5dev *dev = &sh->dev[i]; 330 331 if (dev->toread || dev->read || dev->towrite || dev->written || 332 test_bit(R5_LOCKED, &dev->flags)) { 333 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", 334 (unsigned long long)sh->sector, i, dev->toread, 335 dev->read, dev->towrite, dev->written, 336 test_bit(R5_LOCKED, &dev->flags)); 337 WARN_ON(1); 338 } 339 dev->flags = 0; 340 raid5_build_block(sh, i, previous); 341 } 342 insert_hash(conf, sh); 343 } 344 345 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, 346 short generation) 347 { 348 struct stripe_head *sh; 349 struct hlist_node *hn; 350 351 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); 352 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) 353 if (sh->sector == sector && sh->generation == generation) 354 return sh; 355 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); 356 return NULL; 357 } 358 359 /* 360 * Need to check if array has failed when deciding whether to: 361 * - start an array 362 * - remove non-faulty devices 363 * - add a spare 364 * - allow a reshape 365 * This determination is simple when no reshape is happening. 366 * However if there is a reshape, we need to carefully check 367 * both the before and after sections. 368 * This is because some failed devices may only affect one 369 * of the two sections, and some non-in_sync devices may 370 * be insync in the section most affected by failed devices. 371 */ 372 static int calc_degraded(struct r5conf *conf) 373 { 374 int degraded, degraded2; 375 int i; 376 377 rcu_read_lock(); 378 degraded = 0; 379 for (i = 0; i < conf->previous_raid_disks; i++) { 380 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); 381 if (!rdev || test_bit(Faulty, &rdev->flags)) 382 degraded++; 383 else if (test_bit(In_sync, &rdev->flags)) 384 ; 385 else 386 /* not in-sync or faulty. 387 * If the reshape increases the number of devices, 388 * this is being recovered by the reshape, so 389 * this 'previous' section is not in_sync. 390 * If the number of devices is being reduced however, 391 * the device can only be part of the array if 392 * we are reverting a reshape, so this section will 393 * be in-sync. 394 */ 395 if (conf->raid_disks >= conf->previous_raid_disks) 396 degraded++; 397 } 398 rcu_read_unlock(); 399 if (conf->raid_disks == conf->previous_raid_disks) 400 return degraded; 401 rcu_read_lock(); 402 degraded2 = 0; 403 for (i = 0; i < conf->raid_disks; i++) { 404 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); 405 if (!rdev || test_bit(Faulty, &rdev->flags)) 406 degraded2++; 407 else if (test_bit(In_sync, &rdev->flags)) 408 ; 409 else 410 /* not in-sync or faulty. 411 * If reshape increases the number of devices, this 412 * section has already been recovered, else it 413 * almost certainly hasn't. 414 */ 415 if (conf->raid_disks <= conf->previous_raid_disks) 416 degraded2++; 417 } 418 rcu_read_unlock(); 419 if (degraded2 > degraded) 420 return degraded2; 421 return degraded; 422 } 423 424 static int has_failed(struct r5conf *conf) 425 { 426 int degraded; 427 428 if (conf->mddev->reshape_position == MaxSector) 429 return conf->mddev->degraded > conf->max_degraded; 430 431 degraded = calc_degraded(conf); 432 if (degraded > conf->max_degraded) 433 return 1; 434 return 0; 435 } 436 437 static struct stripe_head * 438 get_active_stripe(struct r5conf *conf, sector_t sector, 439 int previous, int noblock, int noquiesce) 440 { 441 struct stripe_head *sh; 442 443 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); 444 445 spin_lock_irq(&conf->device_lock); 446 447 do { 448 wait_event_lock_irq(conf->wait_for_stripe, 449 conf->quiesce == 0 || noquiesce, 450 conf->device_lock, /* nothing */); 451 sh = __find_stripe(conf, sector, conf->generation - previous); 452 if (!sh) { 453 if (!conf->inactive_blocked) 454 sh = get_free_stripe(conf); 455 if (noblock && sh == NULL) 456 break; 457 if (!sh) { 458 conf->inactive_blocked = 1; 459 wait_event_lock_irq(conf->wait_for_stripe, 460 !list_empty(&conf->inactive_list) && 461 (atomic_read(&conf->active_stripes) 462 < (conf->max_nr_stripes *3/4) 463 || !conf->inactive_blocked), 464 conf->device_lock, 465 ); 466 conf->inactive_blocked = 0; 467 } else 468 init_stripe(sh, sector, previous); 469 } else { 470 if (atomic_read(&sh->count)) { 471 BUG_ON(!list_empty(&sh->lru) 472 && !test_bit(STRIPE_EXPANDING, &sh->state)); 473 } else { 474 if (!test_bit(STRIPE_HANDLE, &sh->state)) 475 atomic_inc(&conf->active_stripes); 476 if (list_empty(&sh->lru) && 477 !test_bit(STRIPE_EXPANDING, &sh->state)) 478 BUG(); 479 list_del_init(&sh->lru); 480 } 481 } 482 } while (sh == NULL); 483 484 if (sh) 485 atomic_inc(&sh->count); 486 487 spin_unlock_irq(&conf->device_lock); 488 return sh; 489 } 490 491 /* Determine if 'data_offset' or 'new_data_offset' should be used 492 * in this stripe_head. 493 */ 494 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh) 495 { 496 sector_t progress = conf->reshape_progress; 497 /* Need a memory barrier to make sure we see the value 498 * of conf->generation, or ->data_offset that was set before 499 * reshape_progress was updated. 500 */ 501 smp_rmb(); 502 if (progress == MaxSector) 503 return 0; 504 if (sh->generation == conf->generation - 1) 505 return 0; 506 /* We are in a reshape, and this is a new-generation stripe, 507 * so use new_data_offset. 508 */ 509 return 1; 510 } 511 512 static void 513 raid5_end_read_request(struct bio *bi, int error); 514 static void 515 raid5_end_write_request(struct bio *bi, int error); 516 517 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 518 { 519 struct r5conf *conf = sh->raid_conf; 520 int i, disks = sh->disks; 521 522 might_sleep(); 523 524 for (i = disks; i--; ) { 525 int rw; 526 int replace_only = 0; 527 struct bio *bi, *rbi; 528 struct md_rdev *rdev, *rrdev = NULL; 529 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { 530 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) 531 rw = WRITE_FUA; 532 else 533 rw = WRITE; 534 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 535 rw = READ; 536 else if (test_and_clear_bit(R5_WantReplace, 537 &sh->dev[i].flags)) { 538 rw = WRITE; 539 replace_only = 1; 540 } else 541 continue; 542 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags)) 543 rw |= REQ_SYNC; 544 545 bi = &sh->dev[i].req; 546 rbi = &sh->dev[i].rreq; /* For writing to replacement */ 547 548 bi->bi_rw = rw; 549 rbi->bi_rw = rw; 550 if (rw & WRITE) { 551 bi->bi_end_io = raid5_end_write_request; 552 rbi->bi_end_io = raid5_end_write_request; 553 } else 554 bi->bi_end_io = raid5_end_read_request; 555 556 rcu_read_lock(); 557 rrdev = rcu_dereference(conf->disks[i].replacement); 558 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */ 559 rdev = rcu_dereference(conf->disks[i].rdev); 560 if (!rdev) { 561 rdev = rrdev; 562 rrdev = NULL; 563 } 564 if (rw & WRITE) { 565 if (replace_only) 566 rdev = NULL; 567 if (rdev == rrdev) 568 /* We raced and saw duplicates */ 569 rrdev = NULL; 570 } else { 571 if (test_bit(R5_ReadRepl, &sh->dev[i].flags) && rrdev) 572 rdev = rrdev; 573 rrdev = NULL; 574 } 575 576 if (rdev && test_bit(Faulty, &rdev->flags)) 577 rdev = NULL; 578 if (rdev) 579 atomic_inc(&rdev->nr_pending); 580 if (rrdev && test_bit(Faulty, &rrdev->flags)) 581 rrdev = NULL; 582 if (rrdev) 583 atomic_inc(&rrdev->nr_pending); 584 rcu_read_unlock(); 585 586 /* We have already checked bad blocks for reads. Now 587 * need to check for writes. We never accept write errors 588 * on the replacement, so we don't to check rrdev. 589 */ 590 while ((rw & WRITE) && rdev && 591 test_bit(WriteErrorSeen, &rdev->flags)) { 592 sector_t first_bad; 593 int bad_sectors; 594 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 595 &first_bad, &bad_sectors); 596 if (!bad) 597 break; 598 599 if (bad < 0) { 600 set_bit(BlockedBadBlocks, &rdev->flags); 601 if (!conf->mddev->external && 602 conf->mddev->flags) { 603 /* It is very unlikely, but we might 604 * still need to write out the 605 * bad block log - better give it 606 * a chance*/ 607 md_check_recovery(conf->mddev); 608 } 609 md_wait_for_blocked_rdev(rdev, conf->mddev); 610 } else { 611 /* Acknowledged bad block - skip the write */ 612 rdev_dec_pending(rdev, conf->mddev); 613 rdev = NULL; 614 } 615 } 616 617 if (rdev) { 618 if (s->syncing || s->expanding || s->expanded 619 || s->replacing) 620 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 621 622 set_bit(STRIPE_IO_STARTED, &sh->state); 623 624 bi->bi_bdev = rdev->bdev; 625 pr_debug("%s: for %llu schedule op %ld on disc %d\n", 626 __func__, (unsigned long long)sh->sector, 627 bi->bi_rw, i); 628 atomic_inc(&sh->count); 629 if (use_new_offset(conf, sh)) 630 bi->bi_sector = (sh->sector 631 + rdev->new_data_offset); 632 else 633 bi->bi_sector = (sh->sector 634 + rdev->data_offset); 635 bi->bi_flags = 1 << BIO_UPTODATE; 636 bi->bi_idx = 0; 637 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 638 bi->bi_io_vec[0].bv_offset = 0; 639 bi->bi_size = STRIPE_SIZE; 640 bi->bi_next = NULL; 641 if (rrdev) 642 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); 643 generic_make_request(bi); 644 } 645 if (rrdev) { 646 if (s->syncing || s->expanding || s->expanded 647 || s->replacing) 648 md_sync_acct(rrdev->bdev, STRIPE_SECTORS); 649 650 set_bit(STRIPE_IO_STARTED, &sh->state); 651 652 rbi->bi_bdev = rrdev->bdev; 653 pr_debug("%s: for %llu schedule op %ld on " 654 "replacement disc %d\n", 655 __func__, (unsigned long long)sh->sector, 656 rbi->bi_rw, i); 657 atomic_inc(&sh->count); 658 if (use_new_offset(conf, sh)) 659 rbi->bi_sector = (sh->sector 660 + rrdev->new_data_offset); 661 else 662 rbi->bi_sector = (sh->sector 663 + rrdev->data_offset); 664 rbi->bi_flags = 1 << BIO_UPTODATE; 665 rbi->bi_idx = 0; 666 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; 667 rbi->bi_io_vec[0].bv_offset = 0; 668 rbi->bi_size = STRIPE_SIZE; 669 rbi->bi_next = NULL; 670 generic_make_request(rbi); 671 } 672 if (!rdev && !rrdev) { 673 if (rw & WRITE) 674 set_bit(STRIPE_DEGRADED, &sh->state); 675 pr_debug("skip op %ld on disc %d for sector %llu\n", 676 bi->bi_rw, i, (unsigned long long)sh->sector); 677 clear_bit(R5_LOCKED, &sh->dev[i].flags); 678 set_bit(STRIPE_HANDLE, &sh->state); 679 } 680 } 681 } 682 683 static struct dma_async_tx_descriptor * 684 async_copy_data(int frombio, struct bio *bio, struct page *page, 685 sector_t sector, struct dma_async_tx_descriptor *tx) 686 { 687 struct bio_vec *bvl; 688 struct page *bio_page; 689 int i; 690 int page_offset; 691 struct async_submit_ctl submit; 692 enum async_tx_flags flags = 0; 693 694 if (bio->bi_sector >= sector) 695 page_offset = (signed)(bio->bi_sector - sector) * 512; 696 else 697 page_offset = (signed)(sector - bio->bi_sector) * -512; 698 699 if (frombio) 700 flags |= ASYNC_TX_FENCE; 701 init_async_submit(&submit, flags, tx, NULL, NULL, NULL); 702 703 bio_for_each_segment(bvl, bio, i) { 704 int len = bvl->bv_len; 705 int clen; 706 int b_offset = 0; 707 708 if (page_offset < 0) { 709 b_offset = -page_offset; 710 page_offset += b_offset; 711 len -= b_offset; 712 } 713 714 if (len > 0 && page_offset + len > STRIPE_SIZE) 715 clen = STRIPE_SIZE - page_offset; 716 else 717 clen = len; 718 719 if (clen > 0) { 720 b_offset += bvl->bv_offset; 721 bio_page = bvl->bv_page; 722 if (frombio) 723 tx = async_memcpy(page, bio_page, page_offset, 724 b_offset, clen, &submit); 725 else 726 tx = async_memcpy(bio_page, page, b_offset, 727 page_offset, clen, &submit); 728 } 729 /* chain the operations */ 730 submit.depend_tx = tx; 731 732 if (clen < len) /* hit end of page */ 733 break; 734 page_offset += len; 735 } 736 737 return tx; 738 } 739 740 static void ops_complete_biofill(void *stripe_head_ref) 741 { 742 struct stripe_head *sh = stripe_head_ref; 743 struct bio *return_bi = NULL; 744 struct r5conf *conf = sh->raid_conf; 745 int i; 746 747 pr_debug("%s: stripe %llu\n", __func__, 748 (unsigned long long)sh->sector); 749 750 /* clear completed biofills */ 751 spin_lock_irq(&conf->device_lock); 752 for (i = sh->disks; i--; ) { 753 struct r5dev *dev = &sh->dev[i]; 754 755 /* acknowledge completion of a biofill operation */ 756 /* and check if we need to reply to a read request, 757 * new R5_Wantfill requests are held off until 758 * !STRIPE_BIOFILL_RUN 759 */ 760 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { 761 struct bio *rbi, *rbi2; 762 763 BUG_ON(!dev->read); 764 rbi = dev->read; 765 dev->read = NULL; 766 while (rbi && rbi->bi_sector < 767 dev->sector + STRIPE_SECTORS) { 768 rbi2 = r5_next_bio(rbi, dev->sector); 769 if (!raid5_dec_bi_phys_segments(rbi)) { 770 rbi->bi_next = return_bi; 771 return_bi = rbi; 772 } 773 rbi = rbi2; 774 } 775 } 776 } 777 spin_unlock_irq(&conf->device_lock); 778 clear_bit(STRIPE_BIOFILL_RUN, &sh->state); 779 780 return_io(return_bi); 781 782 set_bit(STRIPE_HANDLE, &sh->state); 783 release_stripe(sh); 784 } 785 786 static void ops_run_biofill(struct stripe_head *sh) 787 { 788 struct dma_async_tx_descriptor *tx = NULL; 789 struct r5conf *conf = sh->raid_conf; 790 struct async_submit_ctl submit; 791 int i; 792 793 pr_debug("%s: stripe %llu\n", __func__, 794 (unsigned long long)sh->sector); 795 796 for (i = sh->disks; i--; ) { 797 struct r5dev *dev = &sh->dev[i]; 798 if (test_bit(R5_Wantfill, &dev->flags)) { 799 struct bio *rbi; 800 spin_lock_irq(&conf->device_lock); 801 dev->read = rbi = dev->toread; 802 dev->toread = NULL; 803 spin_unlock_irq(&conf->device_lock); 804 while (rbi && rbi->bi_sector < 805 dev->sector + STRIPE_SECTORS) { 806 tx = async_copy_data(0, rbi, dev->page, 807 dev->sector, tx); 808 rbi = r5_next_bio(rbi, dev->sector); 809 } 810 } 811 } 812 813 atomic_inc(&sh->count); 814 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); 815 async_trigger_callback(&submit); 816 } 817 818 static void mark_target_uptodate(struct stripe_head *sh, int target) 819 { 820 struct r5dev *tgt; 821 822 if (target < 0) 823 return; 824 825 tgt = &sh->dev[target]; 826 set_bit(R5_UPTODATE, &tgt->flags); 827 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 828 clear_bit(R5_Wantcompute, &tgt->flags); 829 } 830 831 static void ops_complete_compute(void *stripe_head_ref) 832 { 833 struct stripe_head *sh = stripe_head_ref; 834 835 pr_debug("%s: stripe %llu\n", __func__, 836 (unsigned long long)sh->sector); 837 838 /* mark the computed target(s) as uptodate */ 839 mark_target_uptodate(sh, sh->ops.target); 840 mark_target_uptodate(sh, sh->ops.target2); 841 842 clear_bit(STRIPE_COMPUTE_RUN, &sh->state); 843 if (sh->check_state == check_state_compute_run) 844 sh->check_state = check_state_compute_result; 845 set_bit(STRIPE_HANDLE, &sh->state); 846 release_stripe(sh); 847 } 848 849 /* return a pointer to the address conversion region of the scribble buffer */ 850 static addr_conv_t *to_addr_conv(struct stripe_head *sh, 851 struct raid5_percpu *percpu) 852 { 853 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); 854 } 855 856 static struct dma_async_tx_descriptor * 857 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 858 { 859 int disks = sh->disks; 860 struct page **xor_srcs = percpu->scribble; 861 int target = sh->ops.target; 862 struct r5dev *tgt = &sh->dev[target]; 863 struct page *xor_dest = tgt->page; 864 int count = 0; 865 struct dma_async_tx_descriptor *tx; 866 struct async_submit_ctl submit; 867 int i; 868 869 pr_debug("%s: stripe %llu block: %d\n", 870 __func__, (unsigned long long)sh->sector, target); 871 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 872 873 for (i = disks; i--; ) 874 if (i != target) 875 xor_srcs[count++] = sh->dev[i].page; 876 877 atomic_inc(&sh->count); 878 879 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, 880 ops_complete_compute, sh, to_addr_conv(sh, percpu)); 881 if (unlikely(count == 1)) 882 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 883 else 884 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 885 886 return tx; 887 } 888 889 /* set_syndrome_sources - populate source buffers for gen_syndrome 890 * @srcs - (struct page *) array of size sh->disks 891 * @sh - stripe_head to parse 892 * 893 * Populates srcs in proper layout order for the stripe and returns the 894 * 'count' of sources to be used in a call to async_gen_syndrome. The P 895 * destination buffer is recorded in srcs[count] and the Q destination 896 * is recorded in srcs[count+1]]. 897 */ 898 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) 899 { 900 int disks = sh->disks; 901 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); 902 int d0_idx = raid6_d0(sh); 903 int count; 904 int i; 905 906 for (i = 0; i < disks; i++) 907 srcs[i] = NULL; 908 909 count = 0; 910 i = d0_idx; 911 do { 912 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 913 914 srcs[slot] = sh->dev[i].page; 915 i = raid6_next_disk(i, disks); 916 } while (i != d0_idx); 917 918 return syndrome_disks; 919 } 920 921 static struct dma_async_tx_descriptor * 922 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) 923 { 924 int disks = sh->disks; 925 struct page **blocks = percpu->scribble; 926 int target; 927 int qd_idx = sh->qd_idx; 928 struct dma_async_tx_descriptor *tx; 929 struct async_submit_ctl submit; 930 struct r5dev *tgt; 931 struct page *dest; 932 int i; 933 int count; 934 935 if (sh->ops.target < 0) 936 target = sh->ops.target2; 937 else if (sh->ops.target2 < 0) 938 target = sh->ops.target; 939 else 940 /* we should only have one valid target */ 941 BUG(); 942 BUG_ON(target < 0); 943 pr_debug("%s: stripe %llu block: %d\n", 944 __func__, (unsigned long long)sh->sector, target); 945 946 tgt = &sh->dev[target]; 947 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 948 dest = tgt->page; 949 950 atomic_inc(&sh->count); 951 952 if (target == qd_idx) { 953 count = set_syndrome_sources(blocks, sh); 954 blocks[count] = NULL; /* regenerating p is not necessary */ 955 BUG_ON(blocks[count+1] != dest); /* q should already be set */ 956 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 957 ops_complete_compute, sh, 958 to_addr_conv(sh, percpu)); 959 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 960 } else { 961 /* Compute any data- or p-drive using XOR */ 962 count = 0; 963 for (i = disks; i-- ; ) { 964 if (i == target || i == qd_idx) 965 continue; 966 blocks[count++] = sh->dev[i].page; 967 } 968 969 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 970 NULL, ops_complete_compute, sh, 971 to_addr_conv(sh, percpu)); 972 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); 973 } 974 975 return tx; 976 } 977 978 static struct dma_async_tx_descriptor * 979 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) 980 { 981 int i, count, disks = sh->disks; 982 int syndrome_disks = sh->ddf_layout ? disks : disks-2; 983 int d0_idx = raid6_d0(sh); 984 int faila = -1, failb = -1; 985 int target = sh->ops.target; 986 int target2 = sh->ops.target2; 987 struct r5dev *tgt = &sh->dev[target]; 988 struct r5dev *tgt2 = &sh->dev[target2]; 989 struct dma_async_tx_descriptor *tx; 990 struct page **blocks = percpu->scribble; 991 struct async_submit_ctl submit; 992 993 pr_debug("%s: stripe %llu block1: %d block2: %d\n", 994 __func__, (unsigned long long)sh->sector, target, target2); 995 BUG_ON(target < 0 || target2 < 0); 996 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 997 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); 998 999 /* we need to open-code set_syndrome_sources to handle the 1000 * slot number conversion for 'faila' and 'failb' 1001 */ 1002 for (i = 0; i < disks ; i++) 1003 blocks[i] = NULL; 1004 count = 0; 1005 i = d0_idx; 1006 do { 1007 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 1008 1009 blocks[slot] = sh->dev[i].page; 1010 1011 if (i == target) 1012 faila = slot; 1013 if (i == target2) 1014 failb = slot; 1015 i = raid6_next_disk(i, disks); 1016 } while (i != d0_idx); 1017 1018 BUG_ON(faila == failb); 1019 if (failb < faila) 1020 swap(faila, failb); 1021 pr_debug("%s: stripe: %llu faila: %d failb: %d\n", 1022 __func__, (unsigned long long)sh->sector, faila, failb); 1023 1024 atomic_inc(&sh->count); 1025 1026 if (failb == syndrome_disks+1) { 1027 /* Q disk is one of the missing disks */ 1028 if (faila == syndrome_disks) { 1029 /* Missing P+Q, just recompute */ 1030 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 1031 ops_complete_compute, sh, 1032 to_addr_conv(sh, percpu)); 1033 return async_gen_syndrome(blocks, 0, syndrome_disks+2, 1034 STRIPE_SIZE, &submit); 1035 } else { 1036 struct page *dest; 1037 int data_target; 1038 int qd_idx = sh->qd_idx; 1039 1040 /* Missing D+Q: recompute D from P, then recompute Q */ 1041 if (target == qd_idx) 1042 data_target = target2; 1043 else 1044 data_target = target; 1045 1046 count = 0; 1047 for (i = disks; i-- ; ) { 1048 if (i == data_target || i == qd_idx) 1049 continue; 1050 blocks[count++] = sh->dev[i].page; 1051 } 1052 dest = sh->dev[data_target].page; 1053 init_async_submit(&submit, 1054 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 1055 NULL, NULL, NULL, 1056 to_addr_conv(sh, percpu)); 1057 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, 1058 &submit); 1059 1060 count = set_syndrome_sources(blocks, sh); 1061 init_async_submit(&submit, ASYNC_TX_FENCE, tx, 1062 ops_complete_compute, sh, 1063 to_addr_conv(sh, percpu)); 1064 return async_gen_syndrome(blocks, 0, count+2, 1065 STRIPE_SIZE, &submit); 1066 } 1067 } else { 1068 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 1069 ops_complete_compute, sh, 1070 to_addr_conv(sh, percpu)); 1071 if (failb == syndrome_disks) { 1072 /* We're missing D+P. */ 1073 return async_raid6_datap_recov(syndrome_disks+2, 1074 STRIPE_SIZE, faila, 1075 blocks, &submit); 1076 } else { 1077 /* We're missing D+D. */ 1078 return async_raid6_2data_recov(syndrome_disks+2, 1079 STRIPE_SIZE, faila, failb, 1080 blocks, &submit); 1081 } 1082 } 1083 } 1084 1085 1086 static void ops_complete_prexor(void *stripe_head_ref) 1087 { 1088 struct stripe_head *sh = stripe_head_ref; 1089 1090 pr_debug("%s: stripe %llu\n", __func__, 1091 (unsigned long long)sh->sector); 1092 } 1093 1094 static struct dma_async_tx_descriptor * 1095 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu, 1096 struct dma_async_tx_descriptor *tx) 1097 { 1098 int disks = sh->disks; 1099 struct page **xor_srcs = percpu->scribble; 1100 int count = 0, pd_idx = sh->pd_idx, i; 1101 struct async_submit_ctl submit; 1102 1103 /* existing parity data subtracted */ 1104 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1105 1106 pr_debug("%s: stripe %llu\n", __func__, 1107 (unsigned long long)sh->sector); 1108 1109 for (i = disks; i--; ) { 1110 struct r5dev *dev = &sh->dev[i]; 1111 /* Only process blocks that are known to be uptodate */ 1112 if (test_bit(R5_Wantdrain, &dev->flags)) 1113 xor_srcs[count++] = dev->page; 1114 } 1115 1116 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, 1117 ops_complete_prexor, sh, to_addr_conv(sh, percpu)); 1118 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1119 1120 return tx; 1121 } 1122 1123 static struct dma_async_tx_descriptor * 1124 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 1125 { 1126 int disks = sh->disks; 1127 int i; 1128 1129 pr_debug("%s: stripe %llu\n", __func__, 1130 (unsigned long long)sh->sector); 1131 1132 for (i = disks; i--; ) { 1133 struct r5dev *dev = &sh->dev[i]; 1134 struct bio *chosen; 1135 1136 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { 1137 struct bio *wbi; 1138 1139 spin_lock_irq(&sh->raid_conf->device_lock); 1140 chosen = dev->towrite; 1141 dev->towrite = NULL; 1142 BUG_ON(dev->written); 1143 wbi = dev->written = chosen; 1144 spin_unlock_irq(&sh->raid_conf->device_lock); 1145 1146 while (wbi && wbi->bi_sector < 1147 dev->sector + STRIPE_SECTORS) { 1148 if (wbi->bi_rw & REQ_FUA) 1149 set_bit(R5_WantFUA, &dev->flags); 1150 if (wbi->bi_rw & REQ_SYNC) 1151 set_bit(R5_SyncIO, &dev->flags); 1152 tx = async_copy_data(1, wbi, dev->page, 1153 dev->sector, tx); 1154 wbi = r5_next_bio(wbi, dev->sector); 1155 } 1156 } 1157 } 1158 1159 return tx; 1160 } 1161 1162 static void ops_complete_reconstruct(void *stripe_head_ref) 1163 { 1164 struct stripe_head *sh = stripe_head_ref; 1165 int disks = sh->disks; 1166 int pd_idx = sh->pd_idx; 1167 int qd_idx = sh->qd_idx; 1168 int i; 1169 bool fua = false, sync = false; 1170 1171 pr_debug("%s: stripe %llu\n", __func__, 1172 (unsigned long long)sh->sector); 1173 1174 for (i = disks; i--; ) { 1175 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); 1176 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags); 1177 } 1178 1179 for (i = disks; i--; ) { 1180 struct r5dev *dev = &sh->dev[i]; 1181 1182 if (dev->written || i == pd_idx || i == qd_idx) { 1183 set_bit(R5_UPTODATE, &dev->flags); 1184 if (fua) 1185 set_bit(R5_WantFUA, &dev->flags); 1186 if (sync) 1187 set_bit(R5_SyncIO, &dev->flags); 1188 } 1189 } 1190 1191 if (sh->reconstruct_state == reconstruct_state_drain_run) 1192 sh->reconstruct_state = reconstruct_state_drain_result; 1193 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) 1194 sh->reconstruct_state = reconstruct_state_prexor_drain_result; 1195 else { 1196 BUG_ON(sh->reconstruct_state != reconstruct_state_run); 1197 sh->reconstruct_state = reconstruct_state_result; 1198 } 1199 1200 set_bit(STRIPE_HANDLE, &sh->state); 1201 release_stripe(sh); 1202 } 1203 1204 static void 1205 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 1206 struct dma_async_tx_descriptor *tx) 1207 { 1208 int disks = sh->disks; 1209 struct page **xor_srcs = percpu->scribble; 1210 struct async_submit_ctl submit; 1211 int count = 0, pd_idx = sh->pd_idx, i; 1212 struct page *xor_dest; 1213 int prexor = 0; 1214 unsigned long flags; 1215 1216 pr_debug("%s: stripe %llu\n", __func__, 1217 (unsigned long long)sh->sector); 1218 1219 /* check if prexor is active which means only process blocks 1220 * that are part of a read-modify-write (written) 1221 */ 1222 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { 1223 prexor = 1; 1224 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1225 for (i = disks; i--; ) { 1226 struct r5dev *dev = &sh->dev[i]; 1227 if (dev->written) 1228 xor_srcs[count++] = dev->page; 1229 } 1230 } else { 1231 xor_dest = sh->dev[pd_idx].page; 1232 for (i = disks; i--; ) { 1233 struct r5dev *dev = &sh->dev[i]; 1234 if (i != pd_idx) 1235 xor_srcs[count++] = dev->page; 1236 } 1237 } 1238 1239 /* 1/ if we prexor'd then the dest is reused as a source 1240 * 2/ if we did not prexor then we are redoing the parity 1241 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST 1242 * for the synchronous xor case 1243 */ 1244 flags = ASYNC_TX_ACK | 1245 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); 1246 1247 atomic_inc(&sh->count); 1248 1249 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, 1250 to_addr_conv(sh, percpu)); 1251 if (unlikely(count == 1)) 1252 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 1253 else 1254 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1255 } 1256 1257 static void 1258 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, 1259 struct dma_async_tx_descriptor *tx) 1260 { 1261 struct async_submit_ctl submit; 1262 struct page **blocks = percpu->scribble; 1263 int count; 1264 1265 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); 1266 1267 count = set_syndrome_sources(blocks, sh); 1268 1269 atomic_inc(&sh->count); 1270 1271 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, 1272 sh, to_addr_conv(sh, percpu)); 1273 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 1274 } 1275 1276 static void ops_complete_check(void *stripe_head_ref) 1277 { 1278 struct stripe_head *sh = stripe_head_ref; 1279 1280 pr_debug("%s: stripe %llu\n", __func__, 1281 (unsigned long long)sh->sector); 1282 1283 sh->check_state = check_state_check_result; 1284 set_bit(STRIPE_HANDLE, &sh->state); 1285 release_stripe(sh); 1286 } 1287 1288 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) 1289 { 1290 int disks = sh->disks; 1291 int pd_idx = sh->pd_idx; 1292 int qd_idx = sh->qd_idx; 1293 struct page *xor_dest; 1294 struct page **xor_srcs = percpu->scribble; 1295 struct dma_async_tx_descriptor *tx; 1296 struct async_submit_ctl submit; 1297 int count; 1298 int i; 1299 1300 pr_debug("%s: stripe %llu\n", __func__, 1301 (unsigned long long)sh->sector); 1302 1303 count = 0; 1304 xor_dest = sh->dev[pd_idx].page; 1305 xor_srcs[count++] = xor_dest; 1306 for (i = disks; i--; ) { 1307 if (i == pd_idx || i == qd_idx) 1308 continue; 1309 xor_srcs[count++] = sh->dev[i].page; 1310 } 1311 1312 init_async_submit(&submit, 0, NULL, NULL, NULL, 1313 to_addr_conv(sh, percpu)); 1314 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, 1315 &sh->ops.zero_sum_result, &submit); 1316 1317 atomic_inc(&sh->count); 1318 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); 1319 tx = async_trigger_callback(&submit); 1320 } 1321 1322 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) 1323 { 1324 struct page **srcs = percpu->scribble; 1325 struct async_submit_ctl submit; 1326 int count; 1327 1328 pr_debug("%s: stripe %llu checkp: %d\n", __func__, 1329 (unsigned long long)sh->sector, checkp); 1330 1331 count = set_syndrome_sources(srcs, sh); 1332 if (!checkp) 1333 srcs[count] = NULL; 1334 1335 atomic_inc(&sh->count); 1336 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, 1337 sh, to_addr_conv(sh, percpu)); 1338 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, 1339 &sh->ops.zero_sum_result, percpu->spare_page, &submit); 1340 } 1341 1342 static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1343 { 1344 int overlap_clear = 0, i, disks = sh->disks; 1345 struct dma_async_tx_descriptor *tx = NULL; 1346 struct r5conf *conf = sh->raid_conf; 1347 int level = conf->level; 1348 struct raid5_percpu *percpu; 1349 unsigned long cpu; 1350 1351 cpu = get_cpu(); 1352 percpu = per_cpu_ptr(conf->percpu, cpu); 1353 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { 1354 ops_run_biofill(sh); 1355 overlap_clear++; 1356 } 1357 1358 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { 1359 if (level < 6) 1360 tx = ops_run_compute5(sh, percpu); 1361 else { 1362 if (sh->ops.target2 < 0 || sh->ops.target < 0) 1363 tx = ops_run_compute6_1(sh, percpu); 1364 else 1365 tx = ops_run_compute6_2(sh, percpu); 1366 } 1367 /* terminate the chain if reconstruct is not set to be run */ 1368 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) 1369 async_tx_ack(tx); 1370 } 1371 1372 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) 1373 tx = ops_run_prexor(sh, percpu, tx); 1374 1375 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { 1376 tx = ops_run_biodrain(sh, tx); 1377 overlap_clear++; 1378 } 1379 1380 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { 1381 if (level < 6) 1382 ops_run_reconstruct5(sh, percpu, tx); 1383 else 1384 ops_run_reconstruct6(sh, percpu, tx); 1385 } 1386 1387 if (test_bit(STRIPE_OP_CHECK, &ops_request)) { 1388 if (sh->check_state == check_state_run) 1389 ops_run_check_p(sh, percpu); 1390 else if (sh->check_state == check_state_run_q) 1391 ops_run_check_pq(sh, percpu, 0); 1392 else if (sh->check_state == check_state_run_pq) 1393 ops_run_check_pq(sh, percpu, 1); 1394 else 1395 BUG(); 1396 } 1397 1398 if (overlap_clear) 1399 for (i = disks; i--; ) { 1400 struct r5dev *dev = &sh->dev[i]; 1401 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1402 wake_up(&sh->raid_conf->wait_for_overlap); 1403 } 1404 put_cpu(); 1405 } 1406 1407 #ifdef CONFIG_MULTICORE_RAID456 1408 static void async_run_ops(void *param, async_cookie_t cookie) 1409 { 1410 struct stripe_head *sh = param; 1411 unsigned long ops_request = sh->ops.request; 1412 1413 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); 1414 wake_up(&sh->ops.wait_for_ops); 1415 1416 __raid_run_ops(sh, ops_request); 1417 release_stripe(sh); 1418 } 1419 1420 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1421 { 1422 /* since handle_stripe can be called outside of raid5d context 1423 * we need to ensure sh->ops.request is de-staged before another 1424 * request arrives 1425 */ 1426 wait_event(sh->ops.wait_for_ops, 1427 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); 1428 sh->ops.request = ops_request; 1429 1430 atomic_inc(&sh->count); 1431 async_schedule(async_run_ops, sh); 1432 } 1433 #else 1434 #define raid_run_ops __raid_run_ops 1435 #endif 1436 1437 static int grow_one_stripe(struct r5conf *conf) 1438 { 1439 struct stripe_head *sh; 1440 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL); 1441 if (!sh) 1442 return 0; 1443 1444 sh->raid_conf = conf; 1445 #ifdef CONFIG_MULTICORE_RAID456 1446 init_waitqueue_head(&sh->ops.wait_for_ops); 1447 #endif 1448 1449 if (grow_buffers(sh)) { 1450 shrink_buffers(sh); 1451 kmem_cache_free(conf->slab_cache, sh); 1452 return 0; 1453 } 1454 /* we just created an active stripe so... */ 1455 atomic_set(&sh->count, 1); 1456 atomic_inc(&conf->active_stripes); 1457 INIT_LIST_HEAD(&sh->lru); 1458 release_stripe(sh); 1459 return 1; 1460 } 1461 1462 static int grow_stripes(struct r5conf *conf, int num) 1463 { 1464 struct kmem_cache *sc; 1465 int devs = max(conf->raid_disks, conf->previous_raid_disks); 1466 1467 if (conf->mddev->gendisk) 1468 sprintf(conf->cache_name[0], 1469 "raid%d-%s", conf->level, mdname(conf->mddev)); 1470 else 1471 sprintf(conf->cache_name[0], 1472 "raid%d-%p", conf->level, conf->mddev); 1473 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]); 1474 1475 conf->active_name = 0; 1476 sc = kmem_cache_create(conf->cache_name[conf->active_name], 1477 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 1478 0, 0, NULL); 1479 if (!sc) 1480 return 1; 1481 conf->slab_cache = sc; 1482 conf->pool_size = devs; 1483 while (num--) 1484 if (!grow_one_stripe(conf)) 1485 return 1; 1486 return 0; 1487 } 1488 1489 /** 1490 * scribble_len - return the required size of the scribble region 1491 * @num - total number of disks in the array 1492 * 1493 * The size must be enough to contain: 1494 * 1/ a struct page pointer for each device in the array +2 1495 * 2/ room to convert each entry in (1) to its corresponding dma 1496 * (dma_map_page()) or page (page_address()) address. 1497 * 1498 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we 1499 * calculate over all devices (not just the data blocks), using zeros in place 1500 * of the P and Q blocks. 1501 */ 1502 static size_t scribble_len(int num) 1503 { 1504 size_t len; 1505 1506 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); 1507 1508 return len; 1509 } 1510 1511 static int resize_stripes(struct r5conf *conf, int newsize) 1512 { 1513 /* Make all the stripes able to hold 'newsize' devices. 1514 * New slots in each stripe get 'page' set to a new page. 1515 * 1516 * This happens in stages: 1517 * 1/ create a new kmem_cache and allocate the required number of 1518 * stripe_heads. 1519 * 2/ gather all the old stripe_heads and tranfer the pages across 1520 * to the new stripe_heads. This will have the side effect of 1521 * freezing the array as once all stripe_heads have been collected, 1522 * no IO will be possible. Old stripe heads are freed once their 1523 * pages have been transferred over, and the old kmem_cache is 1524 * freed when all stripes are done. 1525 * 3/ reallocate conf->disks to be suitable bigger. If this fails, 1526 * we simple return a failre status - no need to clean anything up. 1527 * 4/ allocate new pages for the new slots in the new stripe_heads. 1528 * If this fails, we don't bother trying the shrink the 1529 * stripe_heads down again, we just leave them as they are. 1530 * As each stripe_head is processed the new one is released into 1531 * active service. 1532 * 1533 * Once step2 is started, we cannot afford to wait for a write, 1534 * so we use GFP_NOIO allocations. 1535 */ 1536 struct stripe_head *osh, *nsh; 1537 LIST_HEAD(newstripes); 1538 struct disk_info *ndisks; 1539 unsigned long cpu; 1540 int err; 1541 struct kmem_cache *sc; 1542 int i; 1543 1544 if (newsize <= conf->pool_size) 1545 return 0; /* never bother to shrink */ 1546 1547 err = md_allow_write(conf->mddev); 1548 if (err) 1549 return err; 1550 1551 /* Step 1 */ 1552 sc = kmem_cache_create(conf->cache_name[1-conf->active_name], 1553 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), 1554 0, 0, NULL); 1555 if (!sc) 1556 return -ENOMEM; 1557 1558 for (i = conf->max_nr_stripes; i; i--) { 1559 nsh = kmem_cache_zalloc(sc, GFP_KERNEL); 1560 if (!nsh) 1561 break; 1562 1563 nsh->raid_conf = conf; 1564 #ifdef CONFIG_MULTICORE_RAID456 1565 init_waitqueue_head(&nsh->ops.wait_for_ops); 1566 #endif 1567 1568 list_add(&nsh->lru, &newstripes); 1569 } 1570 if (i) { 1571 /* didn't get enough, give up */ 1572 while (!list_empty(&newstripes)) { 1573 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1574 list_del(&nsh->lru); 1575 kmem_cache_free(sc, nsh); 1576 } 1577 kmem_cache_destroy(sc); 1578 return -ENOMEM; 1579 } 1580 /* Step 2 - Must use GFP_NOIO now. 1581 * OK, we have enough stripes, start collecting inactive 1582 * stripes and copying them over 1583 */ 1584 list_for_each_entry(nsh, &newstripes, lru) { 1585 spin_lock_irq(&conf->device_lock); 1586 wait_event_lock_irq(conf->wait_for_stripe, 1587 !list_empty(&conf->inactive_list), 1588 conf->device_lock, 1589 ); 1590 osh = get_free_stripe(conf); 1591 spin_unlock_irq(&conf->device_lock); 1592 atomic_set(&nsh->count, 1); 1593 for(i=0; i<conf->pool_size; i++) 1594 nsh->dev[i].page = osh->dev[i].page; 1595 for( ; i<newsize; i++) 1596 nsh->dev[i].page = NULL; 1597 kmem_cache_free(conf->slab_cache, osh); 1598 } 1599 kmem_cache_destroy(conf->slab_cache); 1600 1601 /* Step 3. 1602 * At this point, we are holding all the stripes so the array 1603 * is completely stalled, so now is a good time to resize 1604 * conf->disks and the scribble region 1605 */ 1606 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); 1607 if (ndisks) { 1608 for (i=0; i<conf->raid_disks; i++) 1609 ndisks[i] = conf->disks[i]; 1610 kfree(conf->disks); 1611 conf->disks = ndisks; 1612 } else 1613 err = -ENOMEM; 1614 1615 get_online_cpus(); 1616 conf->scribble_len = scribble_len(newsize); 1617 for_each_present_cpu(cpu) { 1618 struct raid5_percpu *percpu; 1619 void *scribble; 1620 1621 percpu = per_cpu_ptr(conf->percpu, cpu); 1622 scribble = kmalloc(conf->scribble_len, GFP_NOIO); 1623 1624 if (scribble) { 1625 kfree(percpu->scribble); 1626 percpu->scribble = scribble; 1627 } else { 1628 err = -ENOMEM; 1629 break; 1630 } 1631 } 1632 put_online_cpus(); 1633 1634 /* Step 4, return new stripes to service */ 1635 while(!list_empty(&newstripes)) { 1636 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1637 list_del_init(&nsh->lru); 1638 1639 for (i=conf->raid_disks; i < newsize; i++) 1640 if (nsh->dev[i].page == NULL) { 1641 struct page *p = alloc_page(GFP_NOIO); 1642 nsh->dev[i].page = p; 1643 if (!p) 1644 err = -ENOMEM; 1645 } 1646 release_stripe(nsh); 1647 } 1648 /* critical section pass, GFP_NOIO no longer needed */ 1649 1650 conf->slab_cache = sc; 1651 conf->active_name = 1-conf->active_name; 1652 conf->pool_size = newsize; 1653 return err; 1654 } 1655 1656 static int drop_one_stripe(struct r5conf *conf) 1657 { 1658 struct stripe_head *sh; 1659 1660 spin_lock_irq(&conf->device_lock); 1661 sh = get_free_stripe(conf); 1662 spin_unlock_irq(&conf->device_lock); 1663 if (!sh) 1664 return 0; 1665 BUG_ON(atomic_read(&sh->count)); 1666 shrink_buffers(sh); 1667 kmem_cache_free(conf->slab_cache, sh); 1668 atomic_dec(&conf->active_stripes); 1669 return 1; 1670 } 1671 1672 static void shrink_stripes(struct r5conf *conf) 1673 { 1674 while (drop_one_stripe(conf)) 1675 ; 1676 1677 if (conf->slab_cache) 1678 kmem_cache_destroy(conf->slab_cache); 1679 conf->slab_cache = NULL; 1680 } 1681 1682 static void raid5_end_read_request(struct bio * bi, int error) 1683 { 1684 struct stripe_head *sh = bi->bi_private; 1685 struct r5conf *conf = sh->raid_conf; 1686 int disks = sh->disks, i; 1687 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1688 char b[BDEVNAME_SIZE]; 1689 struct md_rdev *rdev = NULL; 1690 sector_t s; 1691 1692 for (i=0 ; i<disks; i++) 1693 if (bi == &sh->dev[i].req) 1694 break; 1695 1696 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", 1697 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1698 uptodate); 1699 if (i == disks) { 1700 BUG(); 1701 return; 1702 } 1703 if (test_bit(R5_ReadRepl, &sh->dev[i].flags)) 1704 /* If replacement finished while this request was outstanding, 1705 * 'replacement' might be NULL already. 1706 * In that case it moved down to 'rdev'. 1707 * rdev is not removed until all requests are finished. 1708 */ 1709 rdev = conf->disks[i].replacement; 1710 if (!rdev) 1711 rdev = conf->disks[i].rdev; 1712 1713 if (use_new_offset(conf, sh)) 1714 s = sh->sector + rdev->new_data_offset; 1715 else 1716 s = sh->sector + rdev->data_offset; 1717 if (uptodate) { 1718 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1719 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 1720 /* Note that this cannot happen on a 1721 * replacement device. We just fail those on 1722 * any error 1723 */ 1724 printk_ratelimited( 1725 KERN_INFO 1726 "md/raid:%s: read error corrected" 1727 " (%lu sectors at %llu on %s)\n", 1728 mdname(conf->mddev), STRIPE_SECTORS, 1729 (unsigned long long)s, 1730 bdevname(rdev->bdev, b)); 1731 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); 1732 clear_bit(R5_ReadError, &sh->dev[i].flags); 1733 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1734 } 1735 if (atomic_read(&rdev->read_errors)) 1736 atomic_set(&rdev->read_errors, 0); 1737 } else { 1738 const char *bdn = bdevname(rdev->bdev, b); 1739 int retry = 0; 1740 1741 clear_bit(R5_UPTODATE, &sh->dev[i].flags); 1742 atomic_inc(&rdev->read_errors); 1743 if (test_bit(R5_ReadRepl, &sh->dev[i].flags)) 1744 printk_ratelimited( 1745 KERN_WARNING 1746 "md/raid:%s: read error on replacement device " 1747 "(sector %llu on %s).\n", 1748 mdname(conf->mddev), 1749 (unsigned long long)s, 1750 bdn); 1751 else if (conf->mddev->degraded >= conf->max_degraded) 1752 printk_ratelimited( 1753 KERN_WARNING 1754 "md/raid:%s: read error not correctable " 1755 "(sector %llu on %s).\n", 1756 mdname(conf->mddev), 1757 (unsigned long long)s, 1758 bdn); 1759 else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) 1760 /* Oh, no!!! */ 1761 printk_ratelimited( 1762 KERN_WARNING 1763 "md/raid:%s: read error NOT corrected!! " 1764 "(sector %llu on %s).\n", 1765 mdname(conf->mddev), 1766 (unsigned long long)s, 1767 bdn); 1768 else if (atomic_read(&rdev->read_errors) 1769 > conf->max_nr_stripes) 1770 printk(KERN_WARNING 1771 "md/raid:%s: Too many read errors, failing device %s.\n", 1772 mdname(conf->mddev), bdn); 1773 else 1774 retry = 1; 1775 if (retry) 1776 set_bit(R5_ReadError, &sh->dev[i].flags); 1777 else { 1778 clear_bit(R5_ReadError, &sh->dev[i].flags); 1779 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1780 md_error(conf->mddev, rdev); 1781 } 1782 } 1783 rdev_dec_pending(rdev, conf->mddev); 1784 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1785 set_bit(STRIPE_HANDLE, &sh->state); 1786 release_stripe(sh); 1787 } 1788 1789 static void raid5_end_write_request(struct bio *bi, int error) 1790 { 1791 struct stripe_head *sh = bi->bi_private; 1792 struct r5conf *conf = sh->raid_conf; 1793 int disks = sh->disks, i; 1794 struct md_rdev *uninitialized_var(rdev); 1795 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1796 sector_t first_bad; 1797 int bad_sectors; 1798 int replacement = 0; 1799 1800 for (i = 0 ; i < disks; i++) { 1801 if (bi == &sh->dev[i].req) { 1802 rdev = conf->disks[i].rdev; 1803 break; 1804 } 1805 if (bi == &sh->dev[i].rreq) { 1806 rdev = conf->disks[i].replacement; 1807 if (rdev) 1808 replacement = 1; 1809 else 1810 /* rdev was removed and 'replacement' 1811 * replaced it. rdev is not removed 1812 * until all requests are finished. 1813 */ 1814 rdev = conf->disks[i].rdev; 1815 break; 1816 } 1817 } 1818 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", 1819 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1820 uptodate); 1821 if (i == disks) { 1822 BUG(); 1823 return; 1824 } 1825 1826 if (replacement) { 1827 if (!uptodate) 1828 md_error(conf->mddev, rdev); 1829 else if (is_badblock(rdev, sh->sector, 1830 STRIPE_SECTORS, 1831 &first_bad, &bad_sectors)) 1832 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags); 1833 } else { 1834 if (!uptodate) { 1835 set_bit(WriteErrorSeen, &rdev->flags); 1836 set_bit(R5_WriteError, &sh->dev[i].flags); 1837 if (!test_and_set_bit(WantReplacement, &rdev->flags)) 1838 set_bit(MD_RECOVERY_NEEDED, 1839 &rdev->mddev->recovery); 1840 } else if (is_badblock(rdev, sh->sector, 1841 STRIPE_SECTORS, 1842 &first_bad, &bad_sectors)) 1843 set_bit(R5_MadeGood, &sh->dev[i].flags); 1844 } 1845 rdev_dec_pending(rdev, conf->mddev); 1846 1847 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags)) 1848 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1849 set_bit(STRIPE_HANDLE, &sh->state); 1850 release_stripe(sh); 1851 } 1852 1853 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous); 1854 1855 static void raid5_build_block(struct stripe_head *sh, int i, int previous) 1856 { 1857 struct r5dev *dev = &sh->dev[i]; 1858 1859 bio_init(&dev->req); 1860 dev->req.bi_io_vec = &dev->vec; 1861 dev->req.bi_vcnt++; 1862 dev->req.bi_max_vecs++; 1863 dev->req.bi_private = sh; 1864 dev->vec.bv_page = dev->page; 1865 1866 bio_init(&dev->rreq); 1867 dev->rreq.bi_io_vec = &dev->rvec; 1868 dev->rreq.bi_vcnt++; 1869 dev->rreq.bi_max_vecs++; 1870 dev->rreq.bi_private = sh; 1871 dev->rvec.bv_page = dev->page; 1872 1873 dev->flags = 0; 1874 dev->sector = compute_blocknr(sh, i, previous); 1875 } 1876 1877 static void error(struct mddev *mddev, struct md_rdev *rdev) 1878 { 1879 char b[BDEVNAME_SIZE]; 1880 struct r5conf *conf = mddev->private; 1881 unsigned long flags; 1882 pr_debug("raid456: error called\n"); 1883 1884 spin_lock_irqsave(&conf->device_lock, flags); 1885 clear_bit(In_sync, &rdev->flags); 1886 mddev->degraded = calc_degraded(conf); 1887 spin_unlock_irqrestore(&conf->device_lock, flags); 1888 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1889 1890 set_bit(Blocked, &rdev->flags); 1891 set_bit(Faulty, &rdev->flags); 1892 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1893 printk(KERN_ALERT 1894 "md/raid:%s: Disk failure on %s, disabling device.\n" 1895 "md/raid:%s: Operation continuing on %d devices.\n", 1896 mdname(mddev), 1897 bdevname(rdev->bdev, b), 1898 mdname(mddev), 1899 conf->raid_disks - mddev->degraded); 1900 } 1901 1902 /* 1903 * Input: a 'big' sector number, 1904 * Output: index of the data and parity disk, and the sector # in them. 1905 */ 1906 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector, 1907 int previous, int *dd_idx, 1908 struct stripe_head *sh) 1909 { 1910 sector_t stripe, stripe2; 1911 sector_t chunk_number; 1912 unsigned int chunk_offset; 1913 int pd_idx, qd_idx; 1914 int ddf_layout = 0; 1915 sector_t new_sector; 1916 int algorithm = previous ? conf->prev_algo 1917 : conf->algorithm; 1918 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1919 : conf->chunk_sectors; 1920 int raid_disks = previous ? conf->previous_raid_disks 1921 : conf->raid_disks; 1922 int data_disks = raid_disks - conf->max_degraded; 1923 1924 /* First compute the information on this sector */ 1925 1926 /* 1927 * Compute the chunk number and the sector offset inside the chunk 1928 */ 1929 chunk_offset = sector_div(r_sector, sectors_per_chunk); 1930 chunk_number = r_sector; 1931 1932 /* 1933 * Compute the stripe number 1934 */ 1935 stripe = chunk_number; 1936 *dd_idx = sector_div(stripe, data_disks); 1937 stripe2 = stripe; 1938 /* 1939 * Select the parity disk based on the user selected algorithm. 1940 */ 1941 pd_idx = qd_idx = -1; 1942 switch(conf->level) { 1943 case 4: 1944 pd_idx = data_disks; 1945 break; 1946 case 5: 1947 switch (algorithm) { 1948 case ALGORITHM_LEFT_ASYMMETRIC: 1949 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1950 if (*dd_idx >= pd_idx) 1951 (*dd_idx)++; 1952 break; 1953 case ALGORITHM_RIGHT_ASYMMETRIC: 1954 pd_idx = sector_div(stripe2, raid_disks); 1955 if (*dd_idx >= pd_idx) 1956 (*dd_idx)++; 1957 break; 1958 case ALGORITHM_LEFT_SYMMETRIC: 1959 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1960 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1961 break; 1962 case ALGORITHM_RIGHT_SYMMETRIC: 1963 pd_idx = sector_div(stripe2, raid_disks); 1964 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1965 break; 1966 case ALGORITHM_PARITY_0: 1967 pd_idx = 0; 1968 (*dd_idx)++; 1969 break; 1970 case ALGORITHM_PARITY_N: 1971 pd_idx = data_disks; 1972 break; 1973 default: 1974 BUG(); 1975 } 1976 break; 1977 case 6: 1978 1979 switch (algorithm) { 1980 case ALGORITHM_LEFT_ASYMMETRIC: 1981 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1982 qd_idx = pd_idx + 1; 1983 if (pd_idx == raid_disks-1) { 1984 (*dd_idx)++; /* Q D D D P */ 1985 qd_idx = 0; 1986 } else if (*dd_idx >= pd_idx) 1987 (*dd_idx) += 2; /* D D P Q D */ 1988 break; 1989 case ALGORITHM_RIGHT_ASYMMETRIC: 1990 pd_idx = sector_div(stripe2, raid_disks); 1991 qd_idx = pd_idx + 1; 1992 if (pd_idx == raid_disks-1) { 1993 (*dd_idx)++; /* Q D D D P */ 1994 qd_idx = 0; 1995 } else if (*dd_idx >= pd_idx) 1996 (*dd_idx) += 2; /* D D P Q D */ 1997 break; 1998 case ALGORITHM_LEFT_SYMMETRIC: 1999 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 2000 qd_idx = (pd_idx + 1) % raid_disks; 2001 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 2002 break; 2003 case ALGORITHM_RIGHT_SYMMETRIC: 2004 pd_idx = sector_div(stripe2, raid_disks); 2005 qd_idx = (pd_idx + 1) % raid_disks; 2006 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 2007 break; 2008 2009 case ALGORITHM_PARITY_0: 2010 pd_idx = 0; 2011 qd_idx = 1; 2012 (*dd_idx) += 2; 2013 break; 2014 case ALGORITHM_PARITY_N: 2015 pd_idx = data_disks; 2016 qd_idx = data_disks + 1; 2017 break; 2018 2019 case ALGORITHM_ROTATING_ZERO_RESTART: 2020 /* Exactly the same as RIGHT_ASYMMETRIC, but or 2021 * of blocks for computing Q is different. 2022 */ 2023 pd_idx = sector_div(stripe2, raid_disks); 2024 qd_idx = pd_idx + 1; 2025 if (pd_idx == raid_disks-1) { 2026 (*dd_idx)++; /* Q D D D P */ 2027 qd_idx = 0; 2028 } else if (*dd_idx >= pd_idx) 2029 (*dd_idx) += 2; /* D D P Q D */ 2030 ddf_layout = 1; 2031 break; 2032 2033 case ALGORITHM_ROTATING_N_RESTART: 2034 /* Same a left_asymmetric, by first stripe is 2035 * D D D P Q rather than 2036 * Q D D D P 2037 */ 2038 stripe2 += 1; 2039 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 2040 qd_idx = pd_idx + 1; 2041 if (pd_idx == raid_disks-1) { 2042 (*dd_idx)++; /* Q D D D P */ 2043 qd_idx = 0; 2044 } else if (*dd_idx >= pd_idx) 2045 (*dd_idx) += 2; /* D D P Q D */ 2046 ddf_layout = 1; 2047 break; 2048 2049 case ALGORITHM_ROTATING_N_CONTINUE: 2050 /* Same as left_symmetric but Q is before P */ 2051 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 2052 qd_idx = (pd_idx + raid_disks - 1) % raid_disks; 2053 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 2054 ddf_layout = 1; 2055 break; 2056 2057 case ALGORITHM_LEFT_ASYMMETRIC_6: 2058 /* RAID5 left_asymmetric, with Q on last device */ 2059 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 2060 if (*dd_idx >= pd_idx) 2061 (*dd_idx)++; 2062 qd_idx = raid_disks - 1; 2063 break; 2064 2065 case ALGORITHM_RIGHT_ASYMMETRIC_6: 2066 pd_idx = sector_div(stripe2, raid_disks-1); 2067 if (*dd_idx >= pd_idx) 2068 (*dd_idx)++; 2069 qd_idx = raid_disks - 1; 2070 break; 2071 2072 case ALGORITHM_LEFT_SYMMETRIC_6: 2073 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 2074 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 2075 qd_idx = raid_disks - 1; 2076 break; 2077 2078 case ALGORITHM_RIGHT_SYMMETRIC_6: 2079 pd_idx = sector_div(stripe2, raid_disks-1); 2080 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 2081 qd_idx = raid_disks - 1; 2082 break; 2083 2084 case ALGORITHM_PARITY_0_6: 2085 pd_idx = 0; 2086 (*dd_idx)++; 2087 qd_idx = raid_disks - 1; 2088 break; 2089 2090 default: 2091 BUG(); 2092 } 2093 break; 2094 } 2095 2096 if (sh) { 2097 sh->pd_idx = pd_idx; 2098 sh->qd_idx = qd_idx; 2099 sh->ddf_layout = ddf_layout; 2100 } 2101 /* 2102 * Finally, compute the new sector number 2103 */ 2104 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; 2105 return new_sector; 2106 } 2107 2108 2109 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) 2110 { 2111 struct r5conf *conf = sh->raid_conf; 2112 int raid_disks = sh->disks; 2113 int data_disks = raid_disks - conf->max_degraded; 2114 sector_t new_sector = sh->sector, check; 2115 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 2116 : conf->chunk_sectors; 2117 int algorithm = previous ? conf->prev_algo 2118 : conf->algorithm; 2119 sector_t stripe; 2120 int chunk_offset; 2121 sector_t chunk_number; 2122 int dummy1, dd_idx = i; 2123 sector_t r_sector; 2124 struct stripe_head sh2; 2125 2126 2127 chunk_offset = sector_div(new_sector, sectors_per_chunk); 2128 stripe = new_sector; 2129 2130 if (i == sh->pd_idx) 2131 return 0; 2132 switch(conf->level) { 2133 case 4: break; 2134 case 5: 2135 switch (algorithm) { 2136 case ALGORITHM_LEFT_ASYMMETRIC: 2137 case ALGORITHM_RIGHT_ASYMMETRIC: 2138 if (i > sh->pd_idx) 2139 i--; 2140 break; 2141 case ALGORITHM_LEFT_SYMMETRIC: 2142 case ALGORITHM_RIGHT_SYMMETRIC: 2143 if (i < sh->pd_idx) 2144 i += raid_disks; 2145 i -= (sh->pd_idx + 1); 2146 break; 2147 case ALGORITHM_PARITY_0: 2148 i -= 1; 2149 break; 2150 case ALGORITHM_PARITY_N: 2151 break; 2152 default: 2153 BUG(); 2154 } 2155 break; 2156 case 6: 2157 if (i == sh->qd_idx) 2158 return 0; /* It is the Q disk */ 2159 switch (algorithm) { 2160 case ALGORITHM_LEFT_ASYMMETRIC: 2161 case ALGORITHM_RIGHT_ASYMMETRIC: 2162 case ALGORITHM_ROTATING_ZERO_RESTART: 2163 case ALGORITHM_ROTATING_N_RESTART: 2164 if (sh->pd_idx == raid_disks-1) 2165 i--; /* Q D D D P */ 2166 else if (i > sh->pd_idx) 2167 i -= 2; /* D D P Q D */ 2168 break; 2169 case ALGORITHM_LEFT_SYMMETRIC: 2170 case ALGORITHM_RIGHT_SYMMETRIC: 2171 if (sh->pd_idx == raid_disks-1) 2172 i--; /* Q D D D P */ 2173 else { 2174 /* D D P Q D */ 2175 if (i < sh->pd_idx) 2176 i += raid_disks; 2177 i -= (sh->pd_idx + 2); 2178 } 2179 break; 2180 case ALGORITHM_PARITY_0: 2181 i -= 2; 2182 break; 2183 case ALGORITHM_PARITY_N: 2184 break; 2185 case ALGORITHM_ROTATING_N_CONTINUE: 2186 /* Like left_symmetric, but P is before Q */ 2187 if (sh->pd_idx == 0) 2188 i--; /* P D D D Q */ 2189 else { 2190 /* D D Q P D */ 2191 if (i < sh->pd_idx) 2192 i += raid_disks; 2193 i -= (sh->pd_idx + 1); 2194 } 2195 break; 2196 case ALGORITHM_LEFT_ASYMMETRIC_6: 2197 case ALGORITHM_RIGHT_ASYMMETRIC_6: 2198 if (i > sh->pd_idx) 2199 i--; 2200 break; 2201 case ALGORITHM_LEFT_SYMMETRIC_6: 2202 case ALGORITHM_RIGHT_SYMMETRIC_6: 2203 if (i < sh->pd_idx) 2204 i += data_disks + 1; 2205 i -= (sh->pd_idx + 1); 2206 break; 2207 case ALGORITHM_PARITY_0_6: 2208 i -= 1; 2209 break; 2210 default: 2211 BUG(); 2212 } 2213 break; 2214 } 2215 2216 chunk_number = stripe * data_disks + i; 2217 r_sector = chunk_number * sectors_per_chunk + chunk_offset; 2218 2219 check = raid5_compute_sector(conf, r_sector, 2220 previous, &dummy1, &sh2); 2221 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx 2222 || sh2.qd_idx != sh->qd_idx) { 2223 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n", 2224 mdname(conf->mddev)); 2225 return 0; 2226 } 2227 return r_sector; 2228 } 2229 2230 2231 static void 2232 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, 2233 int rcw, int expand) 2234 { 2235 int i, pd_idx = sh->pd_idx, disks = sh->disks; 2236 struct r5conf *conf = sh->raid_conf; 2237 int level = conf->level; 2238 2239 if (rcw) { 2240 /* if we are not expanding this is a proper write request, and 2241 * there will be bios with new data to be drained into the 2242 * stripe cache 2243 */ 2244 if (!expand) { 2245 sh->reconstruct_state = reconstruct_state_drain_run; 2246 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2247 } else 2248 sh->reconstruct_state = reconstruct_state_run; 2249 2250 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2251 2252 for (i = disks; i--; ) { 2253 struct r5dev *dev = &sh->dev[i]; 2254 2255 if (dev->towrite) { 2256 set_bit(R5_LOCKED, &dev->flags); 2257 set_bit(R5_Wantdrain, &dev->flags); 2258 if (!expand) 2259 clear_bit(R5_UPTODATE, &dev->flags); 2260 s->locked++; 2261 } 2262 } 2263 if (s->locked + conf->max_degraded == disks) 2264 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) 2265 atomic_inc(&conf->pending_full_writes); 2266 } else { 2267 BUG_ON(level == 6); 2268 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || 2269 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); 2270 2271 sh->reconstruct_state = reconstruct_state_prexor_drain_run; 2272 set_bit(STRIPE_OP_PREXOR, &s->ops_request); 2273 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2274 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2275 2276 for (i = disks; i--; ) { 2277 struct r5dev *dev = &sh->dev[i]; 2278 if (i == pd_idx) 2279 continue; 2280 2281 if (dev->towrite && 2282 (test_bit(R5_UPTODATE, &dev->flags) || 2283 test_bit(R5_Wantcompute, &dev->flags))) { 2284 set_bit(R5_Wantdrain, &dev->flags); 2285 set_bit(R5_LOCKED, &dev->flags); 2286 clear_bit(R5_UPTODATE, &dev->flags); 2287 s->locked++; 2288 } 2289 } 2290 } 2291 2292 /* keep the parity disk(s) locked while asynchronous operations 2293 * are in flight 2294 */ 2295 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 2296 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2297 s->locked++; 2298 2299 if (level == 6) { 2300 int qd_idx = sh->qd_idx; 2301 struct r5dev *dev = &sh->dev[qd_idx]; 2302 2303 set_bit(R5_LOCKED, &dev->flags); 2304 clear_bit(R5_UPTODATE, &dev->flags); 2305 s->locked++; 2306 } 2307 2308 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", 2309 __func__, (unsigned long long)sh->sector, 2310 s->locked, s->ops_request); 2311 } 2312 2313 /* 2314 * Each stripe/dev can have one or more bion attached. 2315 * toread/towrite point to the first in a chain. 2316 * The bi_next chain must be in order. 2317 */ 2318 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 2319 { 2320 struct bio **bip; 2321 struct r5conf *conf = sh->raid_conf; 2322 int firstwrite=0; 2323 2324 pr_debug("adding bi b#%llu to stripe s#%llu\n", 2325 (unsigned long long)bi->bi_sector, 2326 (unsigned long long)sh->sector); 2327 2328 2329 spin_lock_irq(&conf->device_lock); 2330 if (forwrite) { 2331 bip = &sh->dev[dd_idx].towrite; 2332 if (*bip == NULL && sh->dev[dd_idx].written == NULL) 2333 firstwrite = 1; 2334 } else 2335 bip = &sh->dev[dd_idx].toread; 2336 while (*bip && (*bip)->bi_sector < bi->bi_sector) { 2337 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) 2338 goto overlap; 2339 bip = & (*bip)->bi_next; 2340 } 2341 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) 2342 goto overlap; 2343 2344 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); 2345 if (*bip) 2346 bi->bi_next = *bip; 2347 *bip = bi; 2348 bi->bi_phys_segments++; 2349 2350 if (forwrite) { 2351 /* check if page is covered */ 2352 sector_t sector = sh->dev[dd_idx].sector; 2353 for (bi=sh->dev[dd_idx].towrite; 2354 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && 2355 bi && bi->bi_sector <= sector; 2356 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { 2357 if (bi->bi_sector + (bi->bi_size>>9) >= sector) 2358 sector = bi->bi_sector + (bi->bi_size>>9); 2359 } 2360 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) 2361 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); 2362 } 2363 spin_unlock_irq(&conf->device_lock); 2364 2365 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", 2366 (unsigned long long)(*bip)->bi_sector, 2367 (unsigned long long)sh->sector, dd_idx); 2368 2369 if (conf->mddev->bitmap && firstwrite) { 2370 bitmap_startwrite(conf->mddev->bitmap, sh->sector, 2371 STRIPE_SECTORS, 0); 2372 sh->bm_seq = conf->seq_flush+1; 2373 set_bit(STRIPE_BIT_DELAY, &sh->state); 2374 } 2375 return 1; 2376 2377 overlap: 2378 set_bit(R5_Overlap, &sh->dev[dd_idx].flags); 2379 spin_unlock_irq(&conf->device_lock); 2380 return 0; 2381 } 2382 2383 static void end_reshape(struct r5conf *conf); 2384 2385 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous, 2386 struct stripe_head *sh) 2387 { 2388 int sectors_per_chunk = 2389 previous ? conf->prev_chunk_sectors : conf->chunk_sectors; 2390 int dd_idx; 2391 int chunk_offset = sector_div(stripe, sectors_per_chunk); 2392 int disks = previous ? conf->previous_raid_disks : conf->raid_disks; 2393 2394 raid5_compute_sector(conf, 2395 stripe * (disks - conf->max_degraded) 2396 *sectors_per_chunk + chunk_offset, 2397 previous, 2398 &dd_idx, sh); 2399 } 2400 2401 static void 2402 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, 2403 struct stripe_head_state *s, int disks, 2404 struct bio **return_bi) 2405 { 2406 int i; 2407 for (i = disks; i--; ) { 2408 struct bio *bi; 2409 int bitmap_end = 0; 2410 2411 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 2412 struct md_rdev *rdev; 2413 rcu_read_lock(); 2414 rdev = rcu_dereference(conf->disks[i].rdev); 2415 if (rdev && test_bit(In_sync, &rdev->flags)) 2416 atomic_inc(&rdev->nr_pending); 2417 else 2418 rdev = NULL; 2419 rcu_read_unlock(); 2420 if (rdev) { 2421 if (!rdev_set_badblocks( 2422 rdev, 2423 sh->sector, 2424 STRIPE_SECTORS, 0)) 2425 md_error(conf->mddev, rdev); 2426 rdev_dec_pending(rdev, conf->mddev); 2427 } 2428 } 2429 spin_lock_irq(&conf->device_lock); 2430 /* fail all writes first */ 2431 bi = sh->dev[i].towrite; 2432 sh->dev[i].towrite = NULL; 2433 if (bi) { 2434 s->to_write--; 2435 bitmap_end = 1; 2436 } 2437 2438 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2439 wake_up(&conf->wait_for_overlap); 2440 2441 while (bi && bi->bi_sector < 2442 sh->dev[i].sector + STRIPE_SECTORS) { 2443 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2444 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2445 if (!raid5_dec_bi_phys_segments(bi)) { 2446 md_write_end(conf->mddev); 2447 bi->bi_next = *return_bi; 2448 *return_bi = bi; 2449 } 2450 bi = nextbi; 2451 } 2452 /* and fail all 'written' */ 2453 bi = sh->dev[i].written; 2454 sh->dev[i].written = NULL; 2455 if (bi) bitmap_end = 1; 2456 while (bi && bi->bi_sector < 2457 sh->dev[i].sector + STRIPE_SECTORS) { 2458 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 2459 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2460 if (!raid5_dec_bi_phys_segments(bi)) { 2461 md_write_end(conf->mddev); 2462 bi->bi_next = *return_bi; 2463 *return_bi = bi; 2464 } 2465 bi = bi2; 2466 } 2467 2468 /* fail any reads if this device is non-operational and 2469 * the data has not reached the cache yet. 2470 */ 2471 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && 2472 (!test_bit(R5_Insync, &sh->dev[i].flags) || 2473 test_bit(R5_ReadError, &sh->dev[i].flags))) { 2474 bi = sh->dev[i].toread; 2475 sh->dev[i].toread = NULL; 2476 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2477 wake_up(&conf->wait_for_overlap); 2478 if (bi) s->to_read--; 2479 while (bi && bi->bi_sector < 2480 sh->dev[i].sector + STRIPE_SECTORS) { 2481 struct bio *nextbi = 2482 r5_next_bio(bi, sh->dev[i].sector); 2483 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2484 if (!raid5_dec_bi_phys_segments(bi)) { 2485 bi->bi_next = *return_bi; 2486 *return_bi = bi; 2487 } 2488 bi = nextbi; 2489 } 2490 } 2491 spin_unlock_irq(&conf->device_lock); 2492 if (bitmap_end) 2493 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2494 STRIPE_SECTORS, 0, 0); 2495 /* If we were in the middle of a write the parity block might 2496 * still be locked - so just clear all R5_LOCKED flags 2497 */ 2498 clear_bit(R5_LOCKED, &sh->dev[i].flags); 2499 } 2500 2501 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2502 if (atomic_dec_and_test(&conf->pending_full_writes)) 2503 md_wakeup_thread(conf->mddev->thread); 2504 } 2505 2506 static void 2507 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh, 2508 struct stripe_head_state *s) 2509 { 2510 int abort = 0; 2511 int i; 2512 2513 clear_bit(STRIPE_SYNCING, &sh->state); 2514 s->syncing = 0; 2515 s->replacing = 0; 2516 /* There is nothing more to do for sync/check/repair. 2517 * Don't even need to abort as that is handled elsewhere 2518 * if needed, and not always wanted e.g. if there is a known 2519 * bad block here. 2520 * For recover/replace we need to record a bad block on all 2521 * non-sync devices, or abort the recovery 2522 */ 2523 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) { 2524 /* During recovery devices cannot be removed, so 2525 * locking and refcounting of rdevs is not needed 2526 */ 2527 for (i = 0; i < conf->raid_disks; i++) { 2528 struct md_rdev *rdev = conf->disks[i].rdev; 2529 if (rdev 2530 && !test_bit(Faulty, &rdev->flags) 2531 && !test_bit(In_sync, &rdev->flags) 2532 && !rdev_set_badblocks(rdev, sh->sector, 2533 STRIPE_SECTORS, 0)) 2534 abort = 1; 2535 rdev = conf->disks[i].replacement; 2536 if (rdev 2537 && !test_bit(Faulty, &rdev->flags) 2538 && !test_bit(In_sync, &rdev->flags) 2539 && !rdev_set_badblocks(rdev, sh->sector, 2540 STRIPE_SECTORS, 0)) 2541 abort = 1; 2542 } 2543 if (abort) 2544 conf->recovery_disabled = 2545 conf->mddev->recovery_disabled; 2546 } 2547 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort); 2548 } 2549 2550 static int want_replace(struct stripe_head *sh, int disk_idx) 2551 { 2552 struct md_rdev *rdev; 2553 int rv = 0; 2554 /* Doing recovery so rcu locking not required */ 2555 rdev = sh->raid_conf->disks[disk_idx].replacement; 2556 if (rdev 2557 && !test_bit(Faulty, &rdev->flags) 2558 && !test_bit(In_sync, &rdev->flags) 2559 && (rdev->recovery_offset <= sh->sector 2560 || rdev->mddev->recovery_cp <= sh->sector)) 2561 rv = 1; 2562 2563 return rv; 2564 } 2565 2566 /* fetch_block - checks the given member device to see if its data needs 2567 * to be read or computed to satisfy a request. 2568 * 2569 * Returns 1 when no more member devices need to be checked, otherwise returns 2570 * 0 to tell the loop in handle_stripe_fill to continue 2571 */ 2572 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, 2573 int disk_idx, int disks) 2574 { 2575 struct r5dev *dev = &sh->dev[disk_idx]; 2576 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], 2577 &sh->dev[s->failed_num[1]] }; 2578 2579 /* is the data in this block needed, and can we get it? */ 2580 if (!test_bit(R5_LOCKED, &dev->flags) && 2581 !test_bit(R5_UPTODATE, &dev->flags) && 2582 (dev->toread || 2583 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 2584 s->syncing || s->expanding || 2585 (s->replacing && want_replace(sh, disk_idx)) || 2586 (s->failed >= 1 && fdev[0]->toread) || 2587 (s->failed >= 2 && fdev[1]->toread) || 2588 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && 2589 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || 2590 (sh->raid_conf->level == 6 && s->failed && s->to_write))) { 2591 /* we would like to get this block, possibly by computing it, 2592 * otherwise read it if the backing disk is insync 2593 */ 2594 BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); 2595 BUG_ON(test_bit(R5_Wantread, &dev->flags)); 2596 if ((s->uptodate == disks - 1) && 2597 (s->failed && (disk_idx == s->failed_num[0] || 2598 disk_idx == s->failed_num[1]))) { 2599 /* have disk failed, and we're requested to fetch it; 2600 * do compute it 2601 */ 2602 pr_debug("Computing stripe %llu block %d\n", 2603 (unsigned long long)sh->sector, disk_idx); 2604 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2605 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2606 set_bit(R5_Wantcompute, &dev->flags); 2607 sh->ops.target = disk_idx; 2608 sh->ops.target2 = -1; /* no 2nd target */ 2609 s->req_compute = 1; 2610 /* Careful: from this point on 'uptodate' is in the eye 2611 * of raid_run_ops which services 'compute' operations 2612 * before writes. R5_Wantcompute flags a block that will 2613 * be R5_UPTODATE by the time it is needed for a 2614 * subsequent operation. 2615 */ 2616 s->uptodate++; 2617 return 1; 2618 } else if (s->uptodate == disks-2 && s->failed >= 2) { 2619 /* Computing 2-failure is *very* expensive; only 2620 * do it if failed >= 2 2621 */ 2622 int other; 2623 for (other = disks; other--; ) { 2624 if (other == disk_idx) 2625 continue; 2626 if (!test_bit(R5_UPTODATE, 2627 &sh->dev[other].flags)) 2628 break; 2629 } 2630 BUG_ON(other < 0); 2631 pr_debug("Computing stripe %llu blocks %d,%d\n", 2632 (unsigned long long)sh->sector, 2633 disk_idx, other); 2634 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2635 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2636 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); 2637 set_bit(R5_Wantcompute, &sh->dev[other].flags); 2638 sh->ops.target = disk_idx; 2639 sh->ops.target2 = other; 2640 s->uptodate += 2; 2641 s->req_compute = 1; 2642 return 1; 2643 } else if (test_bit(R5_Insync, &dev->flags)) { 2644 set_bit(R5_LOCKED, &dev->flags); 2645 set_bit(R5_Wantread, &dev->flags); 2646 s->locked++; 2647 pr_debug("Reading block %d (sync=%d)\n", 2648 disk_idx, s->syncing); 2649 } 2650 } 2651 2652 return 0; 2653 } 2654 2655 /** 2656 * handle_stripe_fill - read or compute data to satisfy pending requests. 2657 */ 2658 static void handle_stripe_fill(struct stripe_head *sh, 2659 struct stripe_head_state *s, 2660 int disks) 2661 { 2662 int i; 2663 2664 /* look for blocks to read/compute, skip this if a compute 2665 * is already in flight, or if the stripe contents are in the 2666 * midst of changing due to a write 2667 */ 2668 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && 2669 !sh->reconstruct_state) 2670 for (i = disks; i--; ) 2671 if (fetch_block(sh, s, i, disks)) 2672 break; 2673 set_bit(STRIPE_HANDLE, &sh->state); 2674 } 2675 2676 2677 /* handle_stripe_clean_event 2678 * any written block on an uptodate or failed drive can be returned. 2679 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 2680 * never LOCKED, so we don't need to test 'failed' directly. 2681 */ 2682 static void handle_stripe_clean_event(struct r5conf *conf, 2683 struct stripe_head *sh, int disks, struct bio **return_bi) 2684 { 2685 int i; 2686 struct r5dev *dev; 2687 2688 for (i = disks; i--; ) 2689 if (sh->dev[i].written) { 2690 dev = &sh->dev[i]; 2691 if (!test_bit(R5_LOCKED, &dev->flags) && 2692 test_bit(R5_UPTODATE, &dev->flags)) { 2693 /* We can return any write requests */ 2694 struct bio *wbi, *wbi2; 2695 int bitmap_end = 0; 2696 pr_debug("Return write for disc %d\n", i); 2697 spin_lock_irq(&conf->device_lock); 2698 wbi = dev->written; 2699 dev->written = NULL; 2700 while (wbi && wbi->bi_sector < 2701 dev->sector + STRIPE_SECTORS) { 2702 wbi2 = r5_next_bio(wbi, dev->sector); 2703 if (!raid5_dec_bi_phys_segments(wbi)) { 2704 md_write_end(conf->mddev); 2705 wbi->bi_next = *return_bi; 2706 *return_bi = wbi; 2707 } 2708 wbi = wbi2; 2709 } 2710 if (dev->towrite == NULL) 2711 bitmap_end = 1; 2712 spin_unlock_irq(&conf->device_lock); 2713 if (bitmap_end) 2714 bitmap_endwrite(conf->mddev->bitmap, 2715 sh->sector, 2716 STRIPE_SECTORS, 2717 !test_bit(STRIPE_DEGRADED, &sh->state), 2718 0); 2719 } 2720 } 2721 2722 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2723 if (atomic_dec_and_test(&conf->pending_full_writes)) 2724 md_wakeup_thread(conf->mddev->thread); 2725 } 2726 2727 static void handle_stripe_dirtying(struct r5conf *conf, 2728 struct stripe_head *sh, 2729 struct stripe_head_state *s, 2730 int disks) 2731 { 2732 int rmw = 0, rcw = 0, i; 2733 if (conf->max_degraded == 2) { 2734 /* RAID6 requires 'rcw' in current implementation 2735 * Calculate the real rcw later - for now fake it 2736 * look like rcw is cheaper 2737 */ 2738 rcw = 1; rmw = 2; 2739 } else for (i = disks; i--; ) { 2740 /* would I have to read this buffer for read_modify_write */ 2741 struct r5dev *dev = &sh->dev[i]; 2742 if ((dev->towrite || i == sh->pd_idx) && 2743 !test_bit(R5_LOCKED, &dev->flags) && 2744 !(test_bit(R5_UPTODATE, &dev->flags) || 2745 test_bit(R5_Wantcompute, &dev->flags))) { 2746 if (test_bit(R5_Insync, &dev->flags)) 2747 rmw++; 2748 else 2749 rmw += 2*disks; /* cannot read it */ 2750 } 2751 /* Would I have to read this buffer for reconstruct_write */ 2752 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 2753 !test_bit(R5_LOCKED, &dev->flags) && 2754 !(test_bit(R5_UPTODATE, &dev->flags) || 2755 test_bit(R5_Wantcompute, &dev->flags))) { 2756 if (test_bit(R5_Insync, &dev->flags)) rcw++; 2757 else 2758 rcw += 2*disks; 2759 } 2760 } 2761 pr_debug("for sector %llu, rmw=%d rcw=%d\n", 2762 (unsigned long long)sh->sector, rmw, rcw); 2763 set_bit(STRIPE_HANDLE, &sh->state); 2764 if (rmw < rcw && rmw > 0) 2765 /* prefer read-modify-write, but need to get some data */ 2766 for (i = disks; i--; ) { 2767 struct r5dev *dev = &sh->dev[i]; 2768 if ((dev->towrite || i == sh->pd_idx) && 2769 !test_bit(R5_LOCKED, &dev->flags) && 2770 !(test_bit(R5_UPTODATE, &dev->flags) || 2771 test_bit(R5_Wantcompute, &dev->flags)) && 2772 test_bit(R5_Insync, &dev->flags)) { 2773 if ( 2774 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2775 pr_debug("Read_old block " 2776 "%d for r-m-w\n", i); 2777 set_bit(R5_LOCKED, &dev->flags); 2778 set_bit(R5_Wantread, &dev->flags); 2779 s->locked++; 2780 } else { 2781 set_bit(STRIPE_DELAYED, &sh->state); 2782 set_bit(STRIPE_HANDLE, &sh->state); 2783 } 2784 } 2785 } 2786 if (rcw <= rmw && rcw > 0) { 2787 /* want reconstruct write, but need to get some data */ 2788 rcw = 0; 2789 for (i = disks; i--; ) { 2790 struct r5dev *dev = &sh->dev[i]; 2791 if (!test_bit(R5_OVERWRITE, &dev->flags) && 2792 i != sh->pd_idx && i != sh->qd_idx && 2793 !test_bit(R5_LOCKED, &dev->flags) && 2794 !(test_bit(R5_UPTODATE, &dev->flags) || 2795 test_bit(R5_Wantcompute, &dev->flags))) { 2796 rcw++; 2797 if (!test_bit(R5_Insync, &dev->flags)) 2798 continue; /* it's a failed drive */ 2799 if ( 2800 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2801 pr_debug("Read_old block " 2802 "%d for Reconstruct\n", i); 2803 set_bit(R5_LOCKED, &dev->flags); 2804 set_bit(R5_Wantread, &dev->flags); 2805 s->locked++; 2806 } else { 2807 set_bit(STRIPE_DELAYED, &sh->state); 2808 set_bit(STRIPE_HANDLE, &sh->state); 2809 } 2810 } 2811 } 2812 } 2813 /* now if nothing is locked, and if we have enough data, 2814 * we can start a write request 2815 */ 2816 /* since handle_stripe can be called at any time we need to handle the 2817 * case where a compute block operation has been submitted and then a 2818 * subsequent call wants to start a write request. raid_run_ops only 2819 * handles the case where compute block and reconstruct are requested 2820 * simultaneously. If this is not the case then new writes need to be 2821 * held off until the compute completes. 2822 */ 2823 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && 2824 (s->locked == 0 && (rcw == 0 || rmw == 0) && 2825 !test_bit(STRIPE_BIT_DELAY, &sh->state))) 2826 schedule_reconstruction(sh, s, rcw == 0, 0); 2827 } 2828 2829 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh, 2830 struct stripe_head_state *s, int disks) 2831 { 2832 struct r5dev *dev = NULL; 2833 2834 set_bit(STRIPE_HANDLE, &sh->state); 2835 2836 switch (sh->check_state) { 2837 case check_state_idle: 2838 /* start a new check operation if there are no failures */ 2839 if (s->failed == 0) { 2840 BUG_ON(s->uptodate != disks); 2841 sh->check_state = check_state_run; 2842 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2843 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); 2844 s->uptodate--; 2845 break; 2846 } 2847 dev = &sh->dev[s->failed_num[0]]; 2848 /* fall through */ 2849 case check_state_compute_result: 2850 sh->check_state = check_state_idle; 2851 if (!dev) 2852 dev = &sh->dev[sh->pd_idx]; 2853 2854 /* check that a write has not made the stripe insync */ 2855 if (test_bit(STRIPE_INSYNC, &sh->state)) 2856 break; 2857 2858 /* either failed parity check, or recovery is happening */ 2859 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); 2860 BUG_ON(s->uptodate != disks); 2861 2862 set_bit(R5_LOCKED, &dev->flags); 2863 s->locked++; 2864 set_bit(R5_Wantwrite, &dev->flags); 2865 2866 clear_bit(STRIPE_DEGRADED, &sh->state); 2867 set_bit(STRIPE_INSYNC, &sh->state); 2868 break; 2869 case check_state_run: 2870 break; /* we will be called again upon completion */ 2871 case check_state_check_result: 2872 sh->check_state = check_state_idle; 2873 2874 /* if a failure occurred during the check operation, leave 2875 * STRIPE_INSYNC not set and let the stripe be handled again 2876 */ 2877 if (s->failed) 2878 break; 2879 2880 /* handle a successful check operation, if parity is correct 2881 * we are done. Otherwise update the mismatch count and repair 2882 * parity if !MD_RECOVERY_CHECK 2883 */ 2884 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0) 2885 /* parity is correct (on disc, 2886 * not in buffer any more) 2887 */ 2888 set_bit(STRIPE_INSYNC, &sh->state); 2889 else { 2890 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2891 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2892 /* don't try to repair!! */ 2893 set_bit(STRIPE_INSYNC, &sh->state); 2894 else { 2895 sh->check_state = check_state_compute_run; 2896 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2897 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2898 set_bit(R5_Wantcompute, 2899 &sh->dev[sh->pd_idx].flags); 2900 sh->ops.target = sh->pd_idx; 2901 sh->ops.target2 = -1; 2902 s->uptodate++; 2903 } 2904 } 2905 break; 2906 case check_state_compute_run: 2907 break; 2908 default: 2909 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2910 __func__, sh->check_state, 2911 (unsigned long long) sh->sector); 2912 BUG(); 2913 } 2914 } 2915 2916 2917 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh, 2918 struct stripe_head_state *s, 2919 int disks) 2920 { 2921 int pd_idx = sh->pd_idx; 2922 int qd_idx = sh->qd_idx; 2923 struct r5dev *dev; 2924 2925 set_bit(STRIPE_HANDLE, &sh->state); 2926 2927 BUG_ON(s->failed > 2); 2928 2929 /* Want to check and possibly repair P and Q. 2930 * However there could be one 'failed' device, in which 2931 * case we can only check one of them, possibly using the 2932 * other to generate missing data 2933 */ 2934 2935 switch (sh->check_state) { 2936 case check_state_idle: 2937 /* start a new check operation if there are < 2 failures */ 2938 if (s->failed == s->q_failed) { 2939 /* The only possible failed device holds Q, so it 2940 * makes sense to check P (If anything else were failed, 2941 * we would have used P to recreate it). 2942 */ 2943 sh->check_state = check_state_run; 2944 } 2945 if (!s->q_failed && s->failed < 2) { 2946 /* Q is not failed, and we didn't use it to generate 2947 * anything, so it makes sense to check it 2948 */ 2949 if (sh->check_state == check_state_run) 2950 sh->check_state = check_state_run_pq; 2951 else 2952 sh->check_state = check_state_run_q; 2953 } 2954 2955 /* discard potentially stale zero_sum_result */ 2956 sh->ops.zero_sum_result = 0; 2957 2958 if (sh->check_state == check_state_run) { 2959 /* async_xor_zero_sum destroys the contents of P */ 2960 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2961 s->uptodate--; 2962 } 2963 if (sh->check_state >= check_state_run && 2964 sh->check_state <= check_state_run_pq) { 2965 /* async_syndrome_zero_sum preserves P and Q, so 2966 * no need to mark them !uptodate here 2967 */ 2968 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2969 break; 2970 } 2971 2972 /* we have 2-disk failure */ 2973 BUG_ON(s->failed != 2); 2974 /* fall through */ 2975 case check_state_compute_result: 2976 sh->check_state = check_state_idle; 2977 2978 /* check that a write has not made the stripe insync */ 2979 if (test_bit(STRIPE_INSYNC, &sh->state)) 2980 break; 2981 2982 /* now write out any block on a failed drive, 2983 * or P or Q if they were recomputed 2984 */ 2985 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ 2986 if (s->failed == 2) { 2987 dev = &sh->dev[s->failed_num[1]]; 2988 s->locked++; 2989 set_bit(R5_LOCKED, &dev->flags); 2990 set_bit(R5_Wantwrite, &dev->flags); 2991 } 2992 if (s->failed >= 1) { 2993 dev = &sh->dev[s->failed_num[0]]; 2994 s->locked++; 2995 set_bit(R5_LOCKED, &dev->flags); 2996 set_bit(R5_Wantwrite, &dev->flags); 2997 } 2998 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2999 dev = &sh->dev[pd_idx]; 3000 s->locked++; 3001 set_bit(R5_LOCKED, &dev->flags); 3002 set_bit(R5_Wantwrite, &dev->flags); 3003 } 3004 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 3005 dev = &sh->dev[qd_idx]; 3006 s->locked++; 3007 set_bit(R5_LOCKED, &dev->flags); 3008 set_bit(R5_Wantwrite, &dev->flags); 3009 } 3010 clear_bit(STRIPE_DEGRADED, &sh->state); 3011 3012 set_bit(STRIPE_INSYNC, &sh->state); 3013 break; 3014 case check_state_run: 3015 case check_state_run_q: 3016 case check_state_run_pq: 3017 break; /* we will be called again upon completion */ 3018 case check_state_check_result: 3019 sh->check_state = check_state_idle; 3020 3021 /* handle a successful check operation, if parity is correct 3022 * we are done. Otherwise update the mismatch count and repair 3023 * parity if !MD_RECOVERY_CHECK 3024 */ 3025 if (sh->ops.zero_sum_result == 0) { 3026 /* both parities are correct */ 3027 if (!s->failed) 3028 set_bit(STRIPE_INSYNC, &sh->state); 3029 else { 3030 /* in contrast to the raid5 case we can validate 3031 * parity, but still have a failure to write 3032 * back 3033 */ 3034 sh->check_state = check_state_compute_result; 3035 /* Returning at this point means that we may go 3036 * off and bring p and/or q uptodate again so 3037 * we make sure to check zero_sum_result again 3038 * to verify if p or q need writeback 3039 */ 3040 } 3041 } else { 3042 conf->mddev->resync_mismatches += STRIPE_SECTORS; 3043 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 3044 /* don't try to repair!! */ 3045 set_bit(STRIPE_INSYNC, &sh->state); 3046 else { 3047 int *target = &sh->ops.target; 3048 3049 sh->ops.target = -1; 3050 sh->ops.target2 = -1; 3051 sh->check_state = check_state_compute_run; 3052 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 3053 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 3054 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 3055 set_bit(R5_Wantcompute, 3056 &sh->dev[pd_idx].flags); 3057 *target = pd_idx; 3058 target = &sh->ops.target2; 3059 s->uptodate++; 3060 } 3061 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 3062 set_bit(R5_Wantcompute, 3063 &sh->dev[qd_idx].flags); 3064 *target = qd_idx; 3065 s->uptodate++; 3066 } 3067 } 3068 } 3069 break; 3070 case check_state_compute_run: 3071 break; 3072 default: 3073 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 3074 __func__, sh->check_state, 3075 (unsigned long long) sh->sector); 3076 BUG(); 3077 } 3078 } 3079 3080 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh) 3081 { 3082 int i; 3083 3084 /* We have read all the blocks in this stripe and now we need to 3085 * copy some of them into a target stripe for expand. 3086 */ 3087 struct dma_async_tx_descriptor *tx = NULL; 3088 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); 3089 for (i = 0; i < sh->disks; i++) 3090 if (i != sh->pd_idx && i != sh->qd_idx) { 3091 int dd_idx, j; 3092 struct stripe_head *sh2; 3093 struct async_submit_ctl submit; 3094 3095 sector_t bn = compute_blocknr(sh, i, 1); 3096 sector_t s = raid5_compute_sector(conf, bn, 0, 3097 &dd_idx, NULL); 3098 sh2 = get_active_stripe(conf, s, 0, 1, 1); 3099 if (sh2 == NULL) 3100 /* so far only the early blocks of this stripe 3101 * have been requested. When later blocks 3102 * get requested, we will try again 3103 */ 3104 continue; 3105 if (!test_bit(STRIPE_EXPANDING, &sh2->state) || 3106 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { 3107 /* must have already done this block */ 3108 release_stripe(sh2); 3109 continue; 3110 } 3111 3112 /* place all the copies on one channel */ 3113 init_async_submit(&submit, 0, tx, NULL, NULL, NULL); 3114 tx = async_memcpy(sh2->dev[dd_idx].page, 3115 sh->dev[i].page, 0, 0, STRIPE_SIZE, 3116 &submit); 3117 3118 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); 3119 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); 3120 for (j = 0; j < conf->raid_disks; j++) 3121 if (j != sh2->pd_idx && 3122 j != sh2->qd_idx && 3123 !test_bit(R5_Expanded, &sh2->dev[j].flags)) 3124 break; 3125 if (j == conf->raid_disks) { 3126 set_bit(STRIPE_EXPAND_READY, &sh2->state); 3127 set_bit(STRIPE_HANDLE, &sh2->state); 3128 } 3129 release_stripe(sh2); 3130 3131 } 3132 /* done submitting copies, wait for them to complete */ 3133 if (tx) { 3134 async_tx_ack(tx); 3135 dma_wait_for_async_tx(tx); 3136 } 3137 } 3138 3139 /* 3140 * handle_stripe - do things to a stripe. 3141 * 3142 * We lock the stripe by setting STRIPE_ACTIVE and then examine the 3143 * state of various bits to see what needs to be done. 3144 * Possible results: 3145 * return some read requests which now have data 3146 * return some write requests which are safely on storage 3147 * schedule a read on some buffers 3148 * schedule a write of some buffers 3149 * return confirmation of parity correctness 3150 * 3151 */ 3152 3153 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) 3154 { 3155 struct r5conf *conf = sh->raid_conf; 3156 int disks = sh->disks; 3157 struct r5dev *dev; 3158 int i; 3159 int do_recovery = 0; 3160 3161 memset(s, 0, sizeof(*s)); 3162 3163 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); 3164 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); 3165 s->failed_num[0] = -1; 3166 s->failed_num[1] = -1; 3167 3168 /* Now to look around and see what can be done */ 3169 rcu_read_lock(); 3170 spin_lock_irq(&conf->device_lock); 3171 for (i=disks; i--; ) { 3172 struct md_rdev *rdev; 3173 sector_t first_bad; 3174 int bad_sectors; 3175 int is_bad = 0; 3176 3177 dev = &sh->dev[i]; 3178 3179 pr_debug("check %d: state 0x%lx read %p write %p written %p\n", 3180 i, dev->flags, 3181 dev->toread, dev->towrite, dev->written); 3182 /* maybe we can reply to a read 3183 * 3184 * new wantfill requests are only permitted while 3185 * ops_complete_biofill is guaranteed to be inactive 3186 */ 3187 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && 3188 !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) 3189 set_bit(R5_Wantfill, &dev->flags); 3190 3191 /* now count some things */ 3192 if (test_bit(R5_LOCKED, &dev->flags)) 3193 s->locked++; 3194 if (test_bit(R5_UPTODATE, &dev->flags)) 3195 s->uptodate++; 3196 if (test_bit(R5_Wantcompute, &dev->flags)) { 3197 s->compute++; 3198 BUG_ON(s->compute > 2); 3199 } 3200 3201 if (test_bit(R5_Wantfill, &dev->flags)) 3202 s->to_fill++; 3203 else if (dev->toread) 3204 s->to_read++; 3205 if (dev->towrite) { 3206 s->to_write++; 3207 if (!test_bit(R5_OVERWRITE, &dev->flags)) 3208 s->non_overwrite++; 3209 } 3210 if (dev->written) 3211 s->written++; 3212 /* Prefer to use the replacement for reads, but only 3213 * if it is recovered enough and has no bad blocks. 3214 */ 3215 rdev = rcu_dereference(conf->disks[i].replacement); 3216 if (rdev && !test_bit(Faulty, &rdev->flags) && 3217 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS && 3218 !is_badblock(rdev, sh->sector, STRIPE_SECTORS, 3219 &first_bad, &bad_sectors)) 3220 set_bit(R5_ReadRepl, &dev->flags); 3221 else { 3222 if (rdev) 3223 set_bit(R5_NeedReplace, &dev->flags); 3224 rdev = rcu_dereference(conf->disks[i].rdev); 3225 clear_bit(R5_ReadRepl, &dev->flags); 3226 } 3227 if (rdev && test_bit(Faulty, &rdev->flags)) 3228 rdev = NULL; 3229 if (rdev) { 3230 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 3231 &first_bad, &bad_sectors); 3232 if (s->blocked_rdev == NULL 3233 && (test_bit(Blocked, &rdev->flags) 3234 || is_bad < 0)) { 3235 if (is_bad < 0) 3236 set_bit(BlockedBadBlocks, 3237 &rdev->flags); 3238 s->blocked_rdev = rdev; 3239 atomic_inc(&rdev->nr_pending); 3240 } 3241 } 3242 clear_bit(R5_Insync, &dev->flags); 3243 if (!rdev) 3244 /* Not in-sync */; 3245 else if (is_bad) { 3246 /* also not in-sync */ 3247 if (!test_bit(WriteErrorSeen, &rdev->flags) && 3248 test_bit(R5_UPTODATE, &dev->flags)) { 3249 /* treat as in-sync, but with a read error 3250 * which we can now try to correct 3251 */ 3252 set_bit(R5_Insync, &dev->flags); 3253 set_bit(R5_ReadError, &dev->flags); 3254 } 3255 } else if (test_bit(In_sync, &rdev->flags)) 3256 set_bit(R5_Insync, &dev->flags); 3257 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) 3258 /* in sync if before recovery_offset */ 3259 set_bit(R5_Insync, &dev->flags); 3260 else if (test_bit(R5_UPTODATE, &dev->flags) && 3261 test_bit(R5_Expanded, &dev->flags)) 3262 /* If we've reshaped into here, we assume it is Insync. 3263 * We will shortly update recovery_offset to make 3264 * it official. 3265 */ 3266 set_bit(R5_Insync, &dev->flags); 3267 3268 if (rdev && test_bit(R5_WriteError, &dev->flags)) { 3269 /* This flag does not apply to '.replacement' 3270 * only to .rdev, so make sure to check that*/ 3271 struct md_rdev *rdev2 = rcu_dereference( 3272 conf->disks[i].rdev); 3273 if (rdev2 == rdev) 3274 clear_bit(R5_Insync, &dev->flags); 3275 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { 3276 s->handle_bad_blocks = 1; 3277 atomic_inc(&rdev2->nr_pending); 3278 } else 3279 clear_bit(R5_WriteError, &dev->flags); 3280 } 3281 if (rdev && test_bit(R5_MadeGood, &dev->flags)) { 3282 /* This flag does not apply to '.replacement' 3283 * only to .rdev, so make sure to check that*/ 3284 struct md_rdev *rdev2 = rcu_dereference( 3285 conf->disks[i].rdev); 3286 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { 3287 s->handle_bad_blocks = 1; 3288 atomic_inc(&rdev2->nr_pending); 3289 } else 3290 clear_bit(R5_MadeGood, &dev->flags); 3291 } 3292 if (test_bit(R5_MadeGoodRepl, &dev->flags)) { 3293 struct md_rdev *rdev2 = rcu_dereference( 3294 conf->disks[i].replacement); 3295 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) { 3296 s->handle_bad_blocks = 1; 3297 atomic_inc(&rdev2->nr_pending); 3298 } else 3299 clear_bit(R5_MadeGoodRepl, &dev->flags); 3300 } 3301 if (!test_bit(R5_Insync, &dev->flags)) { 3302 /* The ReadError flag will just be confusing now */ 3303 clear_bit(R5_ReadError, &dev->flags); 3304 clear_bit(R5_ReWrite, &dev->flags); 3305 } 3306 if (test_bit(R5_ReadError, &dev->flags)) 3307 clear_bit(R5_Insync, &dev->flags); 3308 if (!test_bit(R5_Insync, &dev->flags)) { 3309 if (s->failed < 2) 3310 s->failed_num[s->failed] = i; 3311 s->failed++; 3312 if (rdev && !test_bit(Faulty, &rdev->flags)) 3313 do_recovery = 1; 3314 } 3315 } 3316 spin_unlock_irq(&conf->device_lock); 3317 if (test_bit(STRIPE_SYNCING, &sh->state)) { 3318 /* If there is a failed device being replaced, 3319 * we must be recovering. 3320 * else if we are after recovery_cp, we must be syncing 3321 * else if MD_RECOVERY_REQUESTED is set, we also are syncing. 3322 * else we can only be replacing 3323 * sync and recovery both need to read all devices, and so 3324 * use the same flag. 3325 */ 3326 if (do_recovery || 3327 sh->sector >= conf->mddev->recovery_cp || 3328 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery))) 3329 s->syncing = 1; 3330 else 3331 s->replacing = 1; 3332 } 3333 rcu_read_unlock(); 3334 } 3335 3336 static void handle_stripe(struct stripe_head *sh) 3337 { 3338 struct stripe_head_state s; 3339 struct r5conf *conf = sh->raid_conf; 3340 int i; 3341 int prexor; 3342 int disks = sh->disks; 3343 struct r5dev *pdev, *qdev; 3344 3345 clear_bit(STRIPE_HANDLE, &sh->state); 3346 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) { 3347 /* already being handled, ensure it gets handled 3348 * again when current action finishes */ 3349 set_bit(STRIPE_HANDLE, &sh->state); 3350 return; 3351 } 3352 3353 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { 3354 set_bit(STRIPE_SYNCING, &sh->state); 3355 clear_bit(STRIPE_INSYNC, &sh->state); 3356 } 3357 clear_bit(STRIPE_DELAYED, &sh->state); 3358 3359 pr_debug("handling stripe %llu, state=%#lx cnt=%d, " 3360 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", 3361 (unsigned long long)sh->sector, sh->state, 3362 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, 3363 sh->check_state, sh->reconstruct_state); 3364 3365 analyse_stripe(sh, &s); 3366 3367 if (s.handle_bad_blocks) { 3368 set_bit(STRIPE_HANDLE, &sh->state); 3369 goto finish; 3370 } 3371 3372 if (unlikely(s.blocked_rdev)) { 3373 if (s.syncing || s.expanding || s.expanded || 3374 s.replacing || s.to_write || s.written) { 3375 set_bit(STRIPE_HANDLE, &sh->state); 3376 goto finish; 3377 } 3378 /* There is nothing for the blocked_rdev to block */ 3379 rdev_dec_pending(s.blocked_rdev, conf->mddev); 3380 s.blocked_rdev = NULL; 3381 } 3382 3383 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { 3384 set_bit(STRIPE_OP_BIOFILL, &s.ops_request); 3385 set_bit(STRIPE_BIOFILL_RUN, &sh->state); 3386 } 3387 3388 pr_debug("locked=%d uptodate=%d to_read=%d" 3389 " to_write=%d failed=%d failed_num=%d,%d\n", 3390 s.locked, s.uptodate, s.to_read, s.to_write, s.failed, 3391 s.failed_num[0], s.failed_num[1]); 3392 /* check if the array has lost more than max_degraded devices and, 3393 * if so, some requests might need to be failed. 3394 */ 3395 if (s.failed > conf->max_degraded) { 3396 sh->check_state = 0; 3397 sh->reconstruct_state = 0; 3398 if (s.to_read+s.to_write+s.written) 3399 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi); 3400 if (s.syncing + s.replacing) 3401 handle_failed_sync(conf, sh, &s); 3402 } 3403 3404 /* 3405 * might be able to return some write requests if the parity blocks 3406 * are safe, or on a failed drive 3407 */ 3408 pdev = &sh->dev[sh->pd_idx]; 3409 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx) 3410 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx); 3411 qdev = &sh->dev[sh->qd_idx]; 3412 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx) 3413 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx) 3414 || conf->level < 6; 3415 3416 if (s.written && 3417 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags) 3418 && !test_bit(R5_LOCKED, &pdev->flags) 3419 && test_bit(R5_UPTODATE, &pdev->flags)))) && 3420 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags) 3421 && !test_bit(R5_LOCKED, &qdev->flags) 3422 && test_bit(R5_UPTODATE, &qdev->flags))))) 3423 handle_stripe_clean_event(conf, sh, disks, &s.return_bi); 3424 3425 /* Now we might consider reading some blocks, either to check/generate 3426 * parity, or to satisfy requests 3427 * or to load a block that is being partially written. 3428 */ 3429 if (s.to_read || s.non_overwrite 3430 || (conf->level == 6 && s.to_write && s.failed) 3431 || (s.syncing && (s.uptodate + s.compute < disks)) 3432 || s.replacing 3433 || s.expanding) 3434 handle_stripe_fill(sh, &s, disks); 3435 3436 /* Now we check to see if any write operations have recently 3437 * completed 3438 */ 3439 prexor = 0; 3440 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) 3441 prexor = 1; 3442 if (sh->reconstruct_state == reconstruct_state_drain_result || 3443 sh->reconstruct_state == reconstruct_state_prexor_drain_result) { 3444 sh->reconstruct_state = reconstruct_state_idle; 3445 3446 /* All the 'written' buffers and the parity block are ready to 3447 * be written back to disk 3448 */ 3449 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); 3450 BUG_ON(sh->qd_idx >= 0 && 3451 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags)); 3452 for (i = disks; i--; ) { 3453 struct r5dev *dev = &sh->dev[i]; 3454 if (test_bit(R5_LOCKED, &dev->flags) && 3455 (i == sh->pd_idx || i == sh->qd_idx || 3456 dev->written)) { 3457 pr_debug("Writing block %d\n", i); 3458 set_bit(R5_Wantwrite, &dev->flags); 3459 if (prexor) 3460 continue; 3461 if (!test_bit(R5_Insync, &dev->flags) || 3462 ((i == sh->pd_idx || i == sh->qd_idx) && 3463 s.failed == 0)) 3464 set_bit(STRIPE_INSYNC, &sh->state); 3465 } 3466 } 3467 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3468 s.dec_preread_active = 1; 3469 } 3470 3471 /* Now to consider new write requests and what else, if anything 3472 * should be read. We do not handle new writes when: 3473 * 1/ A 'write' operation (copy+xor) is already in flight. 3474 * 2/ A 'check' operation is in flight, as it may clobber the parity 3475 * block. 3476 */ 3477 if (s.to_write && !sh->reconstruct_state && !sh->check_state) 3478 handle_stripe_dirtying(conf, sh, &s, disks); 3479 3480 /* maybe we need to check and possibly fix the parity for this stripe 3481 * Any reads will already have been scheduled, so we just see if enough 3482 * data is available. The parity check is held off while parity 3483 * dependent operations are in flight. 3484 */ 3485 if (sh->check_state || 3486 (s.syncing && s.locked == 0 && 3487 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && 3488 !test_bit(STRIPE_INSYNC, &sh->state))) { 3489 if (conf->level == 6) 3490 handle_parity_checks6(conf, sh, &s, disks); 3491 else 3492 handle_parity_checks5(conf, sh, &s, disks); 3493 } 3494 3495 if (s.replacing && s.locked == 0 3496 && !test_bit(STRIPE_INSYNC, &sh->state)) { 3497 /* Write out to replacement devices where possible */ 3498 for (i = 0; i < conf->raid_disks; i++) 3499 if (test_bit(R5_UPTODATE, &sh->dev[i].flags) && 3500 test_bit(R5_NeedReplace, &sh->dev[i].flags)) { 3501 set_bit(R5_WantReplace, &sh->dev[i].flags); 3502 set_bit(R5_LOCKED, &sh->dev[i].flags); 3503 s.locked++; 3504 } 3505 set_bit(STRIPE_INSYNC, &sh->state); 3506 } 3507 if ((s.syncing || s.replacing) && s.locked == 0 && 3508 test_bit(STRIPE_INSYNC, &sh->state)) { 3509 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3510 clear_bit(STRIPE_SYNCING, &sh->state); 3511 } 3512 3513 /* If the failed drives are just a ReadError, then we might need 3514 * to progress the repair/check process 3515 */ 3516 if (s.failed <= conf->max_degraded && !conf->mddev->ro) 3517 for (i = 0; i < s.failed; i++) { 3518 struct r5dev *dev = &sh->dev[s.failed_num[i]]; 3519 if (test_bit(R5_ReadError, &dev->flags) 3520 && !test_bit(R5_LOCKED, &dev->flags) 3521 && test_bit(R5_UPTODATE, &dev->flags) 3522 ) { 3523 if (!test_bit(R5_ReWrite, &dev->flags)) { 3524 set_bit(R5_Wantwrite, &dev->flags); 3525 set_bit(R5_ReWrite, &dev->flags); 3526 set_bit(R5_LOCKED, &dev->flags); 3527 s.locked++; 3528 } else { 3529 /* let's read it back */ 3530 set_bit(R5_Wantread, &dev->flags); 3531 set_bit(R5_LOCKED, &dev->flags); 3532 s.locked++; 3533 } 3534 } 3535 } 3536 3537 3538 /* Finish reconstruct operations initiated by the expansion process */ 3539 if (sh->reconstruct_state == reconstruct_state_result) { 3540 struct stripe_head *sh_src 3541 = get_active_stripe(conf, sh->sector, 1, 1, 1); 3542 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) { 3543 /* sh cannot be written until sh_src has been read. 3544 * so arrange for sh to be delayed a little 3545 */ 3546 set_bit(STRIPE_DELAYED, &sh->state); 3547 set_bit(STRIPE_HANDLE, &sh->state); 3548 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, 3549 &sh_src->state)) 3550 atomic_inc(&conf->preread_active_stripes); 3551 release_stripe(sh_src); 3552 goto finish; 3553 } 3554 if (sh_src) 3555 release_stripe(sh_src); 3556 3557 sh->reconstruct_state = reconstruct_state_idle; 3558 clear_bit(STRIPE_EXPANDING, &sh->state); 3559 for (i = conf->raid_disks; i--; ) { 3560 set_bit(R5_Wantwrite, &sh->dev[i].flags); 3561 set_bit(R5_LOCKED, &sh->dev[i].flags); 3562 s.locked++; 3563 } 3564 } 3565 3566 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && 3567 !sh->reconstruct_state) { 3568 /* Need to write out all blocks after computing parity */ 3569 sh->disks = conf->raid_disks; 3570 stripe_set_idx(sh->sector, conf, 0, sh); 3571 schedule_reconstruction(sh, &s, 1, 1); 3572 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { 3573 clear_bit(STRIPE_EXPAND_READY, &sh->state); 3574 atomic_dec(&conf->reshape_stripes); 3575 wake_up(&conf->wait_for_overlap); 3576 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3577 } 3578 3579 if (s.expanding && s.locked == 0 && 3580 !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) 3581 handle_stripe_expansion(conf, sh); 3582 3583 finish: 3584 /* wait for this device to become unblocked */ 3585 if (conf->mddev->external && unlikely(s.blocked_rdev)) 3586 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev); 3587 3588 if (s.handle_bad_blocks) 3589 for (i = disks; i--; ) { 3590 struct md_rdev *rdev; 3591 struct r5dev *dev = &sh->dev[i]; 3592 if (test_and_clear_bit(R5_WriteError, &dev->flags)) { 3593 /* We own a safe reference to the rdev */ 3594 rdev = conf->disks[i].rdev; 3595 if (!rdev_set_badblocks(rdev, sh->sector, 3596 STRIPE_SECTORS, 0)) 3597 md_error(conf->mddev, rdev); 3598 rdev_dec_pending(rdev, conf->mddev); 3599 } 3600 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) { 3601 rdev = conf->disks[i].rdev; 3602 rdev_clear_badblocks(rdev, sh->sector, 3603 STRIPE_SECTORS, 0); 3604 rdev_dec_pending(rdev, conf->mddev); 3605 } 3606 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) { 3607 rdev = conf->disks[i].replacement; 3608 if (!rdev) 3609 /* rdev have been moved down */ 3610 rdev = conf->disks[i].rdev; 3611 rdev_clear_badblocks(rdev, sh->sector, 3612 STRIPE_SECTORS, 0); 3613 rdev_dec_pending(rdev, conf->mddev); 3614 } 3615 } 3616 3617 if (s.ops_request) 3618 raid_run_ops(sh, s.ops_request); 3619 3620 ops_run_io(sh, &s); 3621 3622 if (s.dec_preread_active) { 3623 /* We delay this until after ops_run_io so that if make_request 3624 * is waiting on a flush, it won't continue until the writes 3625 * have actually been submitted. 3626 */ 3627 atomic_dec(&conf->preread_active_stripes); 3628 if (atomic_read(&conf->preread_active_stripes) < 3629 IO_THRESHOLD) 3630 md_wakeup_thread(conf->mddev->thread); 3631 } 3632 3633 return_io(s.return_bi); 3634 3635 clear_bit_unlock(STRIPE_ACTIVE, &sh->state); 3636 } 3637 3638 static void raid5_activate_delayed(struct r5conf *conf) 3639 { 3640 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 3641 while (!list_empty(&conf->delayed_list)) { 3642 struct list_head *l = conf->delayed_list.next; 3643 struct stripe_head *sh; 3644 sh = list_entry(l, struct stripe_head, lru); 3645 list_del_init(l); 3646 clear_bit(STRIPE_DELAYED, &sh->state); 3647 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3648 atomic_inc(&conf->preread_active_stripes); 3649 list_add_tail(&sh->lru, &conf->hold_list); 3650 } 3651 } 3652 } 3653 3654 static void activate_bit_delay(struct r5conf *conf) 3655 { 3656 /* device_lock is held */ 3657 struct list_head head; 3658 list_add(&head, &conf->bitmap_list); 3659 list_del_init(&conf->bitmap_list); 3660 while (!list_empty(&head)) { 3661 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); 3662 list_del_init(&sh->lru); 3663 atomic_inc(&sh->count); 3664 __release_stripe(conf, sh); 3665 } 3666 } 3667 3668 int md_raid5_congested(struct mddev *mddev, int bits) 3669 { 3670 struct r5conf *conf = mddev->private; 3671 3672 /* No difference between reads and writes. Just check 3673 * how busy the stripe_cache is 3674 */ 3675 3676 if (conf->inactive_blocked) 3677 return 1; 3678 if (conf->quiesce) 3679 return 1; 3680 if (list_empty_careful(&conf->inactive_list)) 3681 return 1; 3682 3683 return 0; 3684 } 3685 EXPORT_SYMBOL_GPL(md_raid5_congested); 3686 3687 static int raid5_congested(void *data, int bits) 3688 { 3689 struct mddev *mddev = data; 3690 3691 return mddev_congested(mddev, bits) || 3692 md_raid5_congested(mddev, bits); 3693 } 3694 3695 /* We want read requests to align with chunks where possible, 3696 * but write requests don't need to. 3697 */ 3698 static int raid5_mergeable_bvec(struct request_queue *q, 3699 struct bvec_merge_data *bvm, 3700 struct bio_vec *biovec) 3701 { 3702 struct mddev *mddev = q->queuedata; 3703 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 3704 int max; 3705 unsigned int chunk_sectors = mddev->chunk_sectors; 3706 unsigned int bio_sectors = bvm->bi_size >> 9; 3707 3708 if ((bvm->bi_rw & 1) == WRITE) 3709 return biovec->bv_len; /* always allow writes to be mergeable */ 3710 3711 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3712 chunk_sectors = mddev->new_chunk_sectors; 3713 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; 3714 if (max < 0) max = 0; 3715 if (max <= biovec->bv_len && bio_sectors == 0) 3716 return biovec->bv_len; 3717 else 3718 return max; 3719 } 3720 3721 3722 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio) 3723 { 3724 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); 3725 unsigned int chunk_sectors = mddev->chunk_sectors; 3726 unsigned int bio_sectors = bio->bi_size >> 9; 3727 3728 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3729 chunk_sectors = mddev->new_chunk_sectors; 3730 return chunk_sectors >= 3731 ((sector & (chunk_sectors - 1)) + bio_sectors); 3732 } 3733 3734 /* 3735 * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) 3736 * later sampled by raid5d. 3737 */ 3738 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf) 3739 { 3740 unsigned long flags; 3741 3742 spin_lock_irqsave(&conf->device_lock, flags); 3743 3744 bi->bi_next = conf->retry_read_aligned_list; 3745 conf->retry_read_aligned_list = bi; 3746 3747 spin_unlock_irqrestore(&conf->device_lock, flags); 3748 md_wakeup_thread(conf->mddev->thread); 3749 } 3750 3751 3752 static struct bio *remove_bio_from_retry(struct r5conf *conf) 3753 { 3754 struct bio *bi; 3755 3756 bi = conf->retry_read_aligned; 3757 if (bi) { 3758 conf->retry_read_aligned = NULL; 3759 return bi; 3760 } 3761 bi = conf->retry_read_aligned_list; 3762 if(bi) { 3763 conf->retry_read_aligned_list = bi->bi_next; 3764 bi->bi_next = NULL; 3765 /* 3766 * this sets the active strip count to 1 and the processed 3767 * strip count to zero (upper 8 bits) 3768 */ 3769 bi->bi_phys_segments = 1; /* biased count of active stripes */ 3770 } 3771 3772 return bi; 3773 } 3774 3775 3776 /* 3777 * The "raid5_align_endio" should check if the read succeeded and if it 3778 * did, call bio_endio on the original bio (having bio_put the new bio 3779 * first). 3780 * If the read failed.. 3781 */ 3782 static void raid5_align_endio(struct bio *bi, int error) 3783 { 3784 struct bio* raid_bi = bi->bi_private; 3785 struct mddev *mddev; 3786 struct r5conf *conf; 3787 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 3788 struct md_rdev *rdev; 3789 3790 bio_put(bi); 3791 3792 rdev = (void*)raid_bi->bi_next; 3793 raid_bi->bi_next = NULL; 3794 mddev = rdev->mddev; 3795 conf = mddev->private; 3796 3797 rdev_dec_pending(rdev, conf->mddev); 3798 3799 if (!error && uptodate) { 3800 bio_endio(raid_bi, 0); 3801 if (atomic_dec_and_test(&conf->active_aligned_reads)) 3802 wake_up(&conf->wait_for_stripe); 3803 return; 3804 } 3805 3806 3807 pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); 3808 3809 add_bio_to_retry(raid_bi, conf); 3810 } 3811 3812 static int bio_fits_rdev(struct bio *bi) 3813 { 3814 struct request_queue *q = bdev_get_queue(bi->bi_bdev); 3815 3816 if ((bi->bi_size>>9) > queue_max_sectors(q)) 3817 return 0; 3818 blk_recount_segments(q, bi); 3819 if (bi->bi_phys_segments > queue_max_segments(q)) 3820 return 0; 3821 3822 if (q->merge_bvec_fn) 3823 /* it's too hard to apply the merge_bvec_fn at this stage, 3824 * just just give up 3825 */ 3826 return 0; 3827 3828 return 1; 3829 } 3830 3831 3832 static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio) 3833 { 3834 struct r5conf *conf = mddev->private; 3835 int dd_idx; 3836 struct bio* align_bi; 3837 struct md_rdev *rdev; 3838 sector_t end_sector; 3839 3840 if (!in_chunk_boundary(mddev, raid_bio)) { 3841 pr_debug("chunk_aligned_read : non aligned\n"); 3842 return 0; 3843 } 3844 /* 3845 * use bio_clone_mddev to make a copy of the bio 3846 */ 3847 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev); 3848 if (!align_bi) 3849 return 0; 3850 /* 3851 * set bi_end_io to a new function, and set bi_private to the 3852 * original bio. 3853 */ 3854 align_bi->bi_end_io = raid5_align_endio; 3855 align_bi->bi_private = raid_bio; 3856 /* 3857 * compute position 3858 */ 3859 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, 3860 0, 3861 &dd_idx, NULL); 3862 3863 end_sector = align_bi->bi_sector + (align_bi->bi_size >> 9); 3864 rcu_read_lock(); 3865 rdev = rcu_dereference(conf->disks[dd_idx].replacement); 3866 if (!rdev || test_bit(Faulty, &rdev->flags) || 3867 rdev->recovery_offset < end_sector) { 3868 rdev = rcu_dereference(conf->disks[dd_idx].rdev); 3869 if (rdev && 3870 (test_bit(Faulty, &rdev->flags) || 3871 !(test_bit(In_sync, &rdev->flags) || 3872 rdev->recovery_offset >= end_sector))) 3873 rdev = NULL; 3874 } 3875 if (rdev) { 3876 sector_t first_bad; 3877 int bad_sectors; 3878 3879 atomic_inc(&rdev->nr_pending); 3880 rcu_read_unlock(); 3881 raid_bio->bi_next = (void*)rdev; 3882 align_bi->bi_bdev = rdev->bdev; 3883 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); 3884 /* No reshape active, so we can trust rdev->data_offset */ 3885 align_bi->bi_sector += rdev->data_offset; 3886 3887 if (!bio_fits_rdev(align_bi) || 3888 is_badblock(rdev, align_bi->bi_sector, align_bi->bi_size>>9, 3889 &first_bad, &bad_sectors)) { 3890 /* too big in some way, or has a known bad block */ 3891 bio_put(align_bi); 3892 rdev_dec_pending(rdev, mddev); 3893 return 0; 3894 } 3895 3896 spin_lock_irq(&conf->device_lock); 3897 wait_event_lock_irq(conf->wait_for_stripe, 3898 conf->quiesce == 0, 3899 conf->device_lock, /* nothing */); 3900 atomic_inc(&conf->active_aligned_reads); 3901 spin_unlock_irq(&conf->device_lock); 3902 3903 generic_make_request(align_bi); 3904 return 1; 3905 } else { 3906 rcu_read_unlock(); 3907 bio_put(align_bi); 3908 return 0; 3909 } 3910 } 3911 3912 /* __get_priority_stripe - get the next stripe to process 3913 * 3914 * Full stripe writes are allowed to pass preread active stripes up until 3915 * the bypass_threshold is exceeded. In general the bypass_count 3916 * increments when the handle_list is handled before the hold_list; however, it 3917 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a 3918 * stripe with in flight i/o. The bypass_count will be reset when the 3919 * head of the hold_list has changed, i.e. the head was promoted to the 3920 * handle_list. 3921 */ 3922 static struct stripe_head *__get_priority_stripe(struct r5conf *conf) 3923 { 3924 struct stripe_head *sh; 3925 3926 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", 3927 __func__, 3928 list_empty(&conf->handle_list) ? "empty" : "busy", 3929 list_empty(&conf->hold_list) ? "empty" : "busy", 3930 atomic_read(&conf->pending_full_writes), conf->bypass_count); 3931 3932 if (!list_empty(&conf->handle_list)) { 3933 sh = list_entry(conf->handle_list.next, typeof(*sh), lru); 3934 3935 if (list_empty(&conf->hold_list)) 3936 conf->bypass_count = 0; 3937 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { 3938 if (conf->hold_list.next == conf->last_hold) 3939 conf->bypass_count++; 3940 else { 3941 conf->last_hold = conf->hold_list.next; 3942 conf->bypass_count -= conf->bypass_threshold; 3943 if (conf->bypass_count < 0) 3944 conf->bypass_count = 0; 3945 } 3946 } 3947 } else if (!list_empty(&conf->hold_list) && 3948 ((conf->bypass_threshold && 3949 conf->bypass_count > conf->bypass_threshold) || 3950 atomic_read(&conf->pending_full_writes) == 0)) { 3951 sh = list_entry(conf->hold_list.next, 3952 typeof(*sh), lru); 3953 conf->bypass_count -= conf->bypass_threshold; 3954 if (conf->bypass_count < 0) 3955 conf->bypass_count = 0; 3956 } else 3957 return NULL; 3958 3959 list_del_init(&sh->lru); 3960 atomic_inc(&sh->count); 3961 BUG_ON(atomic_read(&sh->count) != 1); 3962 return sh; 3963 } 3964 3965 static void make_request(struct mddev *mddev, struct bio * bi) 3966 { 3967 struct r5conf *conf = mddev->private; 3968 int dd_idx; 3969 sector_t new_sector; 3970 sector_t logical_sector, last_sector; 3971 struct stripe_head *sh; 3972 const int rw = bio_data_dir(bi); 3973 int remaining; 3974 int plugged; 3975 3976 if (unlikely(bi->bi_rw & REQ_FLUSH)) { 3977 md_flush_request(mddev, bi); 3978 return; 3979 } 3980 3981 md_write_start(mddev, bi); 3982 3983 if (rw == READ && 3984 mddev->reshape_position == MaxSector && 3985 chunk_aligned_read(mddev,bi)) 3986 return; 3987 3988 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 3989 last_sector = bi->bi_sector + (bi->bi_size>>9); 3990 bi->bi_next = NULL; 3991 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ 3992 3993 plugged = mddev_check_plugged(mddev); 3994 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 3995 DEFINE_WAIT(w); 3996 int previous; 3997 3998 retry: 3999 previous = 0; 4000 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 4001 if (unlikely(conf->reshape_progress != MaxSector)) { 4002 /* spinlock is needed as reshape_progress may be 4003 * 64bit on a 32bit platform, and so it might be 4004 * possible to see a half-updated value 4005 * Of course reshape_progress could change after 4006 * the lock is dropped, so once we get a reference 4007 * to the stripe that we think it is, we will have 4008 * to check again. 4009 */ 4010 spin_lock_irq(&conf->device_lock); 4011 if (mddev->reshape_backwards 4012 ? logical_sector < conf->reshape_progress 4013 : logical_sector >= conf->reshape_progress) { 4014 previous = 1; 4015 } else { 4016 if (mddev->reshape_backwards 4017 ? logical_sector < conf->reshape_safe 4018 : logical_sector >= conf->reshape_safe) { 4019 spin_unlock_irq(&conf->device_lock); 4020 schedule(); 4021 goto retry; 4022 } 4023 } 4024 spin_unlock_irq(&conf->device_lock); 4025 } 4026 4027 new_sector = raid5_compute_sector(conf, logical_sector, 4028 previous, 4029 &dd_idx, NULL); 4030 pr_debug("raid456: make_request, sector %llu logical %llu\n", 4031 (unsigned long long)new_sector, 4032 (unsigned long long)logical_sector); 4033 4034 sh = get_active_stripe(conf, new_sector, previous, 4035 (bi->bi_rw&RWA_MASK), 0); 4036 if (sh) { 4037 if (unlikely(previous)) { 4038 /* expansion might have moved on while waiting for a 4039 * stripe, so we must do the range check again. 4040 * Expansion could still move past after this 4041 * test, but as we are holding a reference to 4042 * 'sh', we know that if that happens, 4043 * STRIPE_EXPANDING will get set and the expansion 4044 * won't proceed until we finish with the stripe. 4045 */ 4046 int must_retry = 0; 4047 spin_lock_irq(&conf->device_lock); 4048 if (mddev->reshape_backwards 4049 ? logical_sector >= conf->reshape_progress 4050 : logical_sector < conf->reshape_progress) 4051 /* mismatch, need to try again */ 4052 must_retry = 1; 4053 spin_unlock_irq(&conf->device_lock); 4054 if (must_retry) { 4055 release_stripe(sh); 4056 schedule(); 4057 goto retry; 4058 } 4059 } 4060 4061 if (rw == WRITE && 4062 logical_sector >= mddev->suspend_lo && 4063 logical_sector < mddev->suspend_hi) { 4064 release_stripe(sh); 4065 /* As the suspend_* range is controlled by 4066 * userspace, we want an interruptible 4067 * wait. 4068 */ 4069 flush_signals(current); 4070 prepare_to_wait(&conf->wait_for_overlap, 4071 &w, TASK_INTERRUPTIBLE); 4072 if (logical_sector >= mddev->suspend_lo && 4073 logical_sector < mddev->suspend_hi) 4074 schedule(); 4075 goto retry; 4076 } 4077 4078 if (test_bit(STRIPE_EXPANDING, &sh->state) || 4079 !add_stripe_bio(sh, bi, dd_idx, rw)) { 4080 /* Stripe is busy expanding or 4081 * add failed due to overlap. Flush everything 4082 * and wait a while 4083 */ 4084 md_wakeup_thread(mddev->thread); 4085 release_stripe(sh); 4086 schedule(); 4087 goto retry; 4088 } 4089 finish_wait(&conf->wait_for_overlap, &w); 4090 set_bit(STRIPE_HANDLE, &sh->state); 4091 clear_bit(STRIPE_DELAYED, &sh->state); 4092 if ((bi->bi_rw & REQ_SYNC) && 4093 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 4094 atomic_inc(&conf->preread_active_stripes); 4095 release_stripe(sh); 4096 } else { 4097 /* cannot get stripe for read-ahead, just give-up */ 4098 clear_bit(BIO_UPTODATE, &bi->bi_flags); 4099 finish_wait(&conf->wait_for_overlap, &w); 4100 break; 4101 } 4102 4103 } 4104 if (!plugged) 4105 md_wakeup_thread(mddev->thread); 4106 4107 spin_lock_irq(&conf->device_lock); 4108 remaining = raid5_dec_bi_phys_segments(bi); 4109 spin_unlock_irq(&conf->device_lock); 4110 if (remaining == 0) { 4111 4112 if ( rw == WRITE ) 4113 md_write_end(mddev); 4114 4115 bio_endio(bi, 0); 4116 } 4117 } 4118 4119 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks); 4120 4121 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped) 4122 { 4123 /* reshaping is quite different to recovery/resync so it is 4124 * handled quite separately ... here. 4125 * 4126 * On each call to sync_request, we gather one chunk worth of 4127 * destination stripes and flag them as expanding. 4128 * Then we find all the source stripes and request reads. 4129 * As the reads complete, handle_stripe will copy the data 4130 * into the destination stripe and release that stripe. 4131 */ 4132 struct r5conf *conf = mddev->private; 4133 struct stripe_head *sh; 4134 sector_t first_sector, last_sector; 4135 int raid_disks = conf->previous_raid_disks; 4136 int data_disks = raid_disks - conf->max_degraded; 4137 int new_data_disks = conf->raid_disks - conf->max_degraded; 4138 int i; 4139 int dd_idx; 4140 sector_t writepos, readpos, safepos; 4141 sector_t stripe_addr; 4142 int reshape_sectors; 4143 struct list_head stripes; 4144 4145 if (sector_nr == 0) { 4146 /* If restarting in the middle, skip the initial sectors */ 4147 if (mddev->reshape_backwards && 4148 conf->reshape_progress < raid5_size(mddev, 0, 0)) { 4149 sector_nr = raid5_size(mddev, 0, 0) 4150 - conf->reshape_progress; 4151 } else if (!mddev->reshape_backwards && 4152 conf->reshape_progress > 0) 4153 sector_nr = conf->reshape_progress; 4154 sector_div(sector_nr, new_data_disks); 4155 if (sector_nr) { 4156 mddev->curr_resync_completed = sector_nr; 4157 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 4158 *skipped = 1; 4159 return sector_nr; 4160 } 4161 } 4162 4163 /* We need to process a full chunk at a time. 4164 * If old and new chunk sizes differ, we need to process the 4165 * largest of these 4166 */ 4167 if (mddev->new_chunk_sectors > mddev->chunk_sectors) 4168 reshape_sectors = mddev->new_chunk_sectors; 4169 else 4170 reshape_sectors = mddev->chunk_sectors; 4171 4172 /* We update the metadata at least every 10 seconds, or when 4173 * the data about to be copied would over-write the source of 4174 * the data at the front of the range. i.e. one new_stripe 4175 * along from reshape_progress new_maps to after where 4176 * reshape_safe old_maps to 4177 */ 4178 writepos = conf->reshape_progress; 4179 sector_div(writepos, new_data_disks); 4180 readpos = conf->reshape_progress; 4181 sector_div(readpos, data_disks); 4182 safepos = conf->reshape_safe; 4183 sector_div(safepos, data_disks); 4184 if (mddev->reshape_backwards) { 4185 writepos -= min_t(sector_t, reshape_sectors, writepos); 4186 readpos += reshape_sectors; 4187 safepos += reshape_sectors; 4188 } else { 4189 writepos += reshape_sectors; 4190 readpos -= min_t(sector_t, reshape_sectors, readpos); 4191 safepos -= min_t(sector_t, reshape_sectors, safepos); 4192 } 4193 4194 /* Having calculated the 'writepos' possibly use it 4195 * to set 'stripe_addr' which is where we will write to. 4196 */ 4197 if (mddev->reshape_backwards) { 4198 BUG_ON(conf->reshape_progress == 0); 4199 stripe_addr = writepos; 4200 BUG_ON((mddev->dev_sectors & 4201 ~((sector_t)reshape_sectors - 1)) 4202 - reshape_sectors - stripe_addr 4203 != sector_nr); 4204 } else { 4205 BUG_ON(writepos != sector_nr + reshape_sectors); 4206 stripe_addr = sector_nr; 4207 } 4208 4209 /* 'writepos' is the most advanced device address we might write. 4210 * 'readpos' is the least advanced device address we might read. 4211 * 'safepos' is the least address recorded in the metadata as having 4212 * been reshaped. 4213 * If there is a min_offset_diff, these are adjusted either by 4214 * increasing the safepos/readpos if diff is negative, or 4215 * increasing writepos if diff is positive. 4216 * If 'readpos' is then behind 'writepos', there is no way that we can 4217 * ensure safety in the face of a crash - that must be done by userspace 4218 * making a backup of the data. So in that case there is no particular 4219 * rush to update metadata. 4220 * Otherwise if 'safepos' is behind 'writepos', then we really need to 4221 * update the metadata to advance 'safepos' to match 'readpos' so that 4222 * we can be safe in the event of a crash. 4223 * So we insist on updating metadata if safepos is behind writepos and 4224 * readpos is beyond writepos. 4225 * In any case, update the metadata every 10 seconds. 4226 * Maybe that number should be configurable, but I'm not sure it is 4227 * worth it.... maybe it could be a multiple of safemode_delay??? 4228 */ 4229 if (conf->min_offset_diff < 0) { 4230 safepos += -conf->min_offset_diff; 4231 readpos += -conf->min_offset_diff; 4232 } else 4233 writepos += conf->min_offset_diff; 4234 4235 if ((mddev->reshape_backwards 4236 ? (safepos > writepos && readpos < writepos) 4237 : (safepos < writepos && readpos > writepos)) || 4238 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { 4239 /* Cannot proceed until we've updated the superblock... */ 4240 wait_event(conf->wait_for_overlap, 4241 atomic_read(&conf->reshape_stripes)==0); 4242 mddev->reshape_position = conf->reshape_progress; 4243 mddev->curr_resync_completed = sector_nr; 4244 conf->reshape_checkpoint = jiffies; 4245 set_bit(MD_CHANGE_DEVS, &mddev->flags); 4246 md_wakeup_thread(mddev->thread); 4247 wait_event(mddev->sb_wait, mddev->flags == 0 || 4248 kthread_should_stop()); 4249 spin_lock_irq(&conf->device_lock); 4250 conf->reshape_safe = mddev->reshape_position; 4251 spin_unlock_irq(&conf->device_lock); 4252 wake_up(&conf->wait_for_overlap); 4253 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 4254 } 4255 4256 INIT_LIST_HEAD(&stripes); 4257 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { 4258 int j; 4259 int skipped_disk = 0; 4260 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1); 4261 set_bit(STRIPE_EXPANDING, &sh->state); 4262 atomic_inc(&conf->reshape_stripes); 4263 /* If any of this stripe is beyond the end of the old 4264 * array, then we need to zero those blocks 4265 */ 4266 for (j=sh->disks; j--;) { 4267 sector_t s; 4268 if (j == sh->pd_idx) 4269 continue; 4270 if (conf->level == 6 && 4271 j == sh->qd_idx) 4272 continue; 4273 s = compute_blocknr(sh, j, 0); 4274 if (s < raid5_size(mddev, 0, 0)) { 4275 skipped_disk = 1; 4276 continue; 4277 } 4278 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); 4279 set_bit(R5_Expanded, &sh->dev[j].flags); 4280 set_bit(R5_UPTODATE, &sh->dev[j].flags); 4281 } 4282 if (!skipped_disk) { 4283 set_bit(STRIPE_EXPAND_READY, &sh->state); 4284 set_bit(STRIPE_HANDLE, &sh->state); 4285 } 4286 list_add(&sh->lru, &stripes); 4287 } 4288 spin_lock_irq(&conf->device_lock); 4289 if (mddev->reshape_backwards) 4290 conf->reshape_progress -= reshape_sectors * new_data_disks; 4291 else 4292 conf->reshape_progress += reshape_sectors * new_data_disks; 4293 spin_unlock_irq(&conf->device_lock); 4294 /* Ok, those stripe are ready. We can start scheduling 4295 * reads on the source stripes. 4296 * The source stripes are determined by mapping the first and last 4297 * block on the destination stripes. 4298 */ 4299 first_sector = 4300 raid5_compute_sector(conf, stripe_addr*(new_data_disks), 4301 1, &dd_idx, NULL); 4302 last_sector = 4303 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) 4304 * new_data_disks - 1), 4305 1, &dd_idx, NULL); 4306 if (last_sector >= mddev->dev_sectors) 4307 last_sector = mddev->dev_sectors - 1; 4308 while (first_sector <= last_sector) { 4309 sh = get_active_stripe(conf, first_sector, 1, 0, 1); 4310 set_bit(STRIPE_EXPAND_SOURCE, &sh->state); 4311 set_bit(STRIPE_HANDLE, &sh->state); 4312 release_stripe(sh); 4313 first_sector += STRIPE_SECTORS; 4314 } 4315 /* Now that the sources are clearly marked, we can release 4316 * the destination stripes 4317 */ 4318 while (!list_empty(&stripes)) { 4319 sh = list_entry(stripes.next, struct stripe_head, lru); 4320 list_del_init(&sh->lru); 4321 release_stripe(sh); 4322 } 4323 /* If this takes us to the resync_max point where we have to pause, 4324 * then we need to write out the superblock. 4325 */ 4326 sector_nr += reshape_sectors; 4327 if ((sector_nr - mddev->curr_resync_completed) * 2 4328 >= mddev->resync_max - mddev->curr_resync_completed) { 4329 /* Cannot proceed until we've updated the superblock... */ 4330 wait_event(conf->wait_for_overlap, 4331 atomic_read(&conf->reshape_stripes) == 0); 4332 mddev->reshape_position = conf->reshape_progress; 4333 mddev->curr_resync_completed = sector_nr; 4334 conf->reshape_checkpoint = jiffies; 4335 set_bit(MD_CHANGE_DEVS, &mddev->flags); 4336 md_wakeup_thread(mddev->thread); 4337 wait_event(mddev->sb_wait, 4338 !test_bit(MD_CHANGE_DEVS, &mddev->flags) 4339 || kthread_should_stop()); 4340 spin_lock_irq(&conf->device_lock); 4341 conf->reshape_safe = mddev->reshape_position; 4342 spin_unlock_irq(&conf->device_lock); 4343 wake_up(&conf->wait_for_overlap); 4344 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 4345 } 4346 return reshape_sectors; 4347 } 4348 4349 /* FIXME go_faster isn't used */ 4350 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster) 4351 { 4352 struct r5conf *conf = mddev->private; 4353 struct stripe_head *sh; 4354 sector_t max_sector = mddev->dev_sectors; 4355 sector_t sync_blocks; 4356 int still_degraded = 0; 4357 int i; 4358 4359 if (sector_nr >= max_sector) { 4360 /* just being told to finish up .. nothing much to do */ 4361 4362 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { 4363 end_reshape(conf); 4364 return 0; 4365 } 4366 4367 if (mddev->curr_resync < max_sector) /* aborted */ 4368 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 4369 &sync_blocks, 1); 4370 else /* completed sync */ 4371 conf->fullsync = 0; 4372 bitmap_close_sync(mddev->bitmap); 4373 4374 return 0; 4375 } 4376 4377 /* Allow raid5_quiesce to complete */ 4378 wait_event(conf->wait_for_overlap, conf->quiesce != 2); 4379 4380 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) 4381 return reshape_request(mddev, sector_nr, skipped); 4382 4383 /* No need to check resync_max as we never do more than one 4384 * stripe, and as resync_max will always be on a chunk boundary, 4385 * if the check in md_do_sync didn't fire, there is no chance 4386 * of overstepping resync_max here 4387 */ 4388 4389 /* if there is too many failed drives and we are trying 4390 * to resync, then assert that we are finished, because there is 4391 * nothing we can do. 4392 */ 4393 if (mddev->degraded >= conf->max_degraded && 4394 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 4395 sector_t rv = mddev->dev_sectors - sector_nr; 4396 *skipped = 1; 4397 return rv; 4398 } 4399 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 4400 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 4401 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { 4402 /* we can skip this block, and probably more */ 4403 sync_blocks /= STRIPE_SECTORS; 4404 *skipped = 1; 4405 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ 4406 } 4407 4408 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 4409 4410 sh = get_active_stripe(conf, sector_nr, 0, 1, 0); 4411 if (sh == NULL) { 4412 sh = get_active_stripe(conf, sector_nr, 0, 0, 0); 4413 /* make sure we don't swamp the stripe cache if someone else 4414 * is trying to get access 4415 */ 4416 schedule_timeout_uninterruptible(1); 4417 } 4418 /* Need to check if array will still be degraded after recovery/resync 4419 * We don't need to check the 'failed' flag as when that gets set, 4420 * recovery aborts. 4421 */ 4422 for (i = 0; i < conf->raid_disks; i++) 4423 if (conf->disks[i].rdev == NULL) 4424 still_degraded = 1; 4425 4426 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); 4427 4428 set_bit(STRIPE_SYNC_REQUESTED, &sh->state); 4429 4430 handle_stripe(sh); 4431 release_stripe(sh); 4432 4433 return STRIPE_SECTORS; 4434 } 4435 4436 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) 4437 { 4438 /* We may not be able to submit a whole bio at once as there 4439 * may not be enough stripe_heads available. 4440 * We cannot pre-allocate enough stripe_heads as we may need 4441 * more than exist in the cache (if we allow ever large chunks). 4442 * So we do one stripe head at a time and record in 4443 * ->bi_hw_segments how many have been done. 4444 * 4445 * We *know* that this entire raid_bio is in one chunk, so 4446 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. 4447 */ 4448 struct stripe_head *sh; 4449 int dd_idx; 4450 sector_t sector, logical_sector, last_sector; 4451 int scnt = 0; 4452 int remaining; 4453 int handled = 0; 4454 4455 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 4456 sector = raid5_compute_sector(conf, logical_sector, 4457 0, &dd_idx, NULL); 4458 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); 4459 4460 for (; logical_sector < last_sector; 4461 logical_sector += STRIPE_SECTORS, 4462 sector += STRIPE_SECTORS, 4463 scnt++) { 4464 4465 if (scnt < raid5_bi_hw_segments(raid_bio)) 4466 /* already done this stripe */ 4467 continue; 4468 4469 sh = get_active_stripe(conf, sector, 0, 1, 0); 4470 4471 if (!sh) { 4472 /* failed to get a stripe - must wait */ 4473 raid5_set_bi_hw_segments(raid_bio, scnt); 4474 conf->retry_read_aligned = raid_bio; 4475 return handled; 4476 } 4477 4478 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { 4479 release_stripe(sh); 4480 raid5_set_bi_hw_segments(raid_bio, scnt); 4481 conf->retry_read_aligned = raid_bio; 4482 return handled; 4483 } 4484 4485 handle_stripe(sh); 4486 release_stripe(sh); 4487 handled++; 4488 } 4489 spin_lock_irq(&conf->device_lock); 4490 remaining = raid5_dec_bi_phys_segments(raid_bio); 4491 spin_unlock_irq(&conf->device_lock); 4492 if (remaining == 0) 4493 bio_endio(raid_bio, 0); 4494 if (atomic_dec_and_test(&conf->active_aligned_reads)) 4495 wake_up(&conf->wait_for_stripe); 4496 return handled; 4497 } 4498 4499 4500 /* 4501 * This is our raid5 kernel thread. 4502 * 4503 * We scan the hash table for stripes which can be handled now. 4504 * During the scan, completed stripes are saved for us by the interrupt 4505 * handler, so that they will not have to wait for our next wakeup. 4506 */ 4507 static void raid5d(struct mddev *mddev) 4508 { 4509 struct stripe_head *sh; 4510 struct r5conf *conf = mddev->private; 4511 int handled; 4512 struct blk_plug plug; 4513 4514 pr_debug("+++ raid5d active\n"); 4515 4516 md_check_recovery(mddev); 4517 4518 blk_start_plug(&plug); 4519 handled = 0; 4520 spin_lock_irq(&conf->device_lock); 4521 while (1) { 4522 struct bio *bio; 4523 4524 if (atomic_read(&mddev->plug_cnt) == 0 && 4525 !list_empty(&conf->bitmap_list)) { 4526 /* Now is a good time to flush some bitmap updates */ 4527 conf->seq_flush++; 4528 spin_unlock_irq(&conf->device_lock); 4529 bitmap_unplug(mddev->bitmap); 4530 spin_lock_irq(&conf->device_lock); 4531 conf->seq_write = conf->seq_flush; 4532 activate_bit_delay(conf); 4533 } 4534 if (atomic_read(&mddev->plug_cnt) == 0) 4535 raid5_activate_delayed(conf); 4536 4537 while ((bio = remove_bio_from_retry(conf))) { 4538 int ok; 4539 spin_unlock_irq(&conf->device_lock); 4540 ok = retry_aligned_read(conf, bio); 4541 spin_lock_irq(&conf->device_lock); 4542 if (!ok) 4543 break; 4544 handled++; 4545 } 4546 4547 sh = __get_priority_stripe(conf); 4548 4549 if (!sh) 4550 break; 4551 spin_unlock_irq(&conf->device_lock); 4552 4553 handled++; 4554 handle_stripe(sh); 4555 release_stripe(sh); 4556 cond_resched(); 4557 4558 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) 4559 md_check_recovery(mddev); 4560 4561 spin_lock_irq(&conf->device_lock); 4562 } 4563 pr_debug("%d stripes handled\n", handled); 4564 4565 spin_unlock_irq(&conf->device_lock); 4566 4567 async_tx_issue_pending_all(); 4568 blk_finish_plug(&plug); 4569 4570 pr_debug("--- raid5d inactive\n"); 4571 } 4572 4573 static ssize_t 4574 raid5_show_stripe_cache_size(struct mddev *mddev, char *page) 4575 { 4576 struct r5conf *conf = mddev->private; 4577 if (conf) 4578 return sprintf(page, "%d\n", conf->max_nr_stripes); 4579 else 4580 return 0; 4581 } 4582 4583 int 4584 raid5_set_cache_size(struct mddev *mddev, int size) 4585 { 4586 struct r5conf *conf = mddev->private; 4587 int err; 4588 4589 if (size <= 16 || size > 32768) 4590 return -EINVAL; 4591 while (size < conf->max_nr_stripes) { 4592 if (drop_one_stripe(conf)) 4593 conf->max_nr_stripes--; 4594 else 4595 break; 4596 } 4597 err = md_allow_write(mddev); 4598 if (err) 4599 return err; 4600 while (size > conf->max_nr_stripes) { 4601 if (grow_one_stripe(conf)) 4602 conf->max_nr_stripes++; 4603 else break; 4604 } 4605 return 0; 4606 } 4607 EXPORT_SYMBOL(raid5_set_cache_size); 4608 4609 static ssize_t 4610 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len) 4611 { 4612 struct r5conf *conf = mddev->private; 4613 unsigned long new; 4614 int err; 4615 4616 if (len >= PAGE_SIZE) 4617 return -EINVAL; 4618 if (!conf) 4619 return -ENODEV; 4620 4621 if (strict_strtoul(page, 10, &new)) 4622 return -EINVAL; 4623 err = raid5_set_cache_size(mddev, new); 4624 if (err) 4625 return err; 4626 return len; 4627 } 4628 4629 static struct md_sysfs_entry 4630 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, 4631 raid5_show_stripe_cache_size, 4632 raid5_store_stripe_cache_size); 4633 4634 static ssize_t 4635 raid5_show_preread_threshold(struct mddev *mddev, char *page) 4636 { 4637 struct r5conf *conf = mddev->private; 4638 if (conf) 4639 return sprintf(page, "%d\n", conf->bypass_threshold); 4640 else 4641 return 0; 4642 } 4643 4644 static ssize_t 4645 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len) 4646 { 4647 struct r5conf *conf = mddev->private; 4648 unsigned long new; 4649 if (len >= PAGE_SIZE) 4650 return -EINVAL; 4651 if (!conf) 4652 return -ENODEV; 4653 4654 if (strict_strtoul(page, 10, &new)) 4655 return -EINVAL; 4656 if (new > conf->max_nr_stripes) 4657 return -EINVAL; 4658 conf->bypass_threshold = new; 4659 return len; 4660 } 4661 4662 static struct md_sysfs_entry 4663 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, 4664 S_IRUGO | S_IWUSR, 4665 raid5_show_preread_threshold, 4666 raid5_store_preread_threshold); 4667 4668 static ssize_t 4669 stripe_cache_active_show(struct mddev *mddev, char *page) 4670 { 4671 struct r5conf *conf = mddev->private; 4672 if (conf) 4673 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); 4674 else 4675 return 0; 4676 } 4677 4678 static struct md_sysfs_entry 4679 raid5_stripecache_active = __ATTR_RO(stripe_cache_active); 4680 4681 static struct attribute *raid5_attrs[] = { 4682 &raid5_stripecache_size.attr, 4683 &raid5_stripecache_active.attr, 4684 &raid5_preread_bypass_threshold.attr, 4685 NULL, 4686 }; 4687 static struct attribute_group raid5_attrs_group = { 4688 .name = NULL, 4689 .attrs = raid5_attrs, 4690 }; 4691 4692 static sector_t 4693 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks) 4694 { 4695 struct r5conf *conf = mddev->private; 4696 4697 if (!sectors) 4698 sectors = mddev->dev_sectors; 4699 if (!raid_disks) 4700 /* size is defined by the smallest of previous and new size */ 4701 raid_disks = min(conf->raid_disks, conf->previous_raid_disks); 4702 4703 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 4704 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); 4705 return sectors * (raid_disks - conf->max_degraded); 4706 } 4707 4708 static void raid5_free_percpu(struct r5conf *conf) 4709 { 4710 struct raid5_percpu *percpu; 4711 unsigned long cpu; 4712 4713 if (!conf->percpu) 4714 return; 4715 4716 get_online_cpus(); 4717 for_each_possible_cpu(cpu) { 4718 percpu = per_cpu_ptr(conf->percpu, cpu); 4719 safe_put_page(percpu->spare_page); 4720 kfree(percpu->scribble); 4721 } 4722 #ifdef CONFIG_HOTPLUG_CPU 4723 unregister_cpu_notifier(&conf->cpu_notify); 4724 #endif 4725 put_online_cpus(); 4726 4727 free_percpu(conf->percpu); 4728 } 4729 4730 static void free_conf(struct r5conf *conf) 4731 { 4732 shrink_stripes(conf); 4733 raid5_free_percpu(conf); 4734 kfree(conf->disks); 4735 kfree(conf->stripe_hashtbl); 4736 kfree(conf); 4737 } 4738 4739 #ifdef CONFIG_HOTPLUG_CPU 4740 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, 4741 void *hcpu) 4742 { 4743 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify); 4744 long cpu = (long)hcpu; 4745 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); 4746 4747 switch (action) { 4748 case CPU_UP_PREPARE: 4749 case CPU_UP_PREPARE_FROZEN: 4750 if (conf->level == 6 && !percpu->spare_page) 4751 percpu->spare_page = alloc_page(GFP_KERNEL); 4752 if (!percpu->scribble) 4753 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4754 4755 if (!percpu->scribble || 4756 (conf->level == 6 && !percpu->spare_page)) { 4757 safe_put_page(percpu->spare_page); 4758 kfree(percpu->scribble); 4759 pr_err("%s: failed memory allocation for cpu%ld\n", 4760 __func__, cpu); 4761 return notifier_from_errno(-ENOMEM); 4762 } 4763 break; 4764 case CPU_DEAD: 4765 case CPU_DEAD_FROZEN: 4766 safe_put_page(percpu->spare_page); 4767 kfree(percpu->scribble); 4768 percpu->spare_page = NULL; 4769 percpu->scribble = NULL; 4770 break; 4771 default: 4772 break; 4773 } 4774 return NOTIFY_OK; 4775 } 4776 #endif 4777 4778 static int raid5_alloc_percpu(struct r5conf *conf) 4779 { 4780 unsigned long cpu; 4781 struct page *spare_page; 4782 struct raid5_percpu __percpu *allcpus; 4783 void *scribble; 4784 int err; 4785 4786 allcpus = alloc_percpu(struct raid5_percpu); 4787 if (!allcpus) 4788 return -ENOMEM; 4789 conf->percpu = allcpus; 4790 4791 get_online_cpus(); 4792 err = 0; 4793 for_each_present_cpu(cpu) { 4794 if (conf->level == 6) { 4795 spare_page = alloc_page(GFP_KERNEL); 4796 if (!spare_page) { 4797 err = -ENOMEM; 4798 break; 4799 } 4800 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page; 4801 } 4802 scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4803 if (!scribble) { 4804 err = -ENOMEM; 4805 break; 4806 } 4807 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; 4808 } 4809 #ifdef CONFIG_HOTPLUG_CPU 4810 conf->cpu_notify.notifier_call = raid456_cpu_notify; 4811 conf->cpu_notify.priority = 0; 4812 if (err == 0) 4813 err = register_cpu_notifier(&conf->cpu_notify); 4814 #endif 4815 put_online_cpus(); 4816 4817 return err; 4818 } 4819 4820 static struct r5conf *setup_conf(struct mddev *mddev) 4821 { 4822 struct r5conf *conf; 4823 int raid_disk, memory, max_disks; 4824 struct md_rdev *rdev; 4825 struct disk_info *disk; 4826 4827 if (mddev->new_level != 5 4828 && mddev->new_level != 4 4829 && mddev->new_level != 6) { 4830 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n", 4831 mdname(mddev), mddev->new_level); 4832 return ERR_PTR(-EIO); 4833 } 4834 if ((mddev->new_level == 5 4835 && !algorithm_valid_raid5(mddev->new_layout)) || 4836 (mddev->new_level == 6 4837 && !algorithm_valid_raid6(mddev->new_layout))) { 4838 printk(KERN_ERR "md/raid:%s: layout %d not supported\n", 4839 mdname(mddev), mddev->new_layout); 4840 return ERR_PTR(-EIO); 4841 } 4842 if (mddev->new_level == 6 && mddev->raid_disks < 4) { 4843 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n", 4844 mdname(mddev), mddev->raid_disks); 4845 return ERR_PTR(-EINVAL); 4846 } 4847 4848 if (!mddev->new_chunk_sectors || 4849 (mddev->new_chunk_sectors << 9) % PAGE_SIZE || 4850 !is_power_of_2(mddev->new_chunk_sectors)) { 4851 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n", 4852 mdname(mddev), mddev->new_chunk_sectors << 9); 4853 return ERR_PTR(-EINVAL); 4854 } 4855 4856 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL); 4857 if (conf == NULL) 4858 goto abort; 4859 spin_lock_init(&conf->device_lock); 4860 init_waitqueue_head(&conf->wait_for_stripe); 4861 init_waitqueue_head(&conf->wait_for_overlap); 4862 INIT_LIST_HEAD(&conf->handle_list); 4863 INIT_LIST_HEAD(&conf->hold_list); 4864 INIT_LIST_HEAD(&conf->delayed_list); 4865 INIT_LIST_HEAD(&conf->bitmap_list); 4866 INIT_LIST_HEAD(&conf->inactive_list); 4867 atomic_set(&conf->active_stripes, 0); 4868 atomic_set(&conf->preread_active_stripes, 0); 4869 atomic_set(&conf->active_aligned_reads, 0); 4870 conf->bypass_threshold = BYPASS_THRESHOLD; 4871 conf->recovery_disabled = mddev->recovery_disabled - 1; 4872 4873 conf->raid_disks = mddev->raid_disks; 4874 if (mddev->reshape_position == MaxSector) 4875 conf->previous_raid_disks = mddev->raid_disks; 4876 else 4877 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; 4878 max_disks = max(conf->raid_disks, conf->previous_raid_disks); 4879 conf->scribble_len = scribble_len(max_disks); 4880 4881 conf->disks = kzalloc(max_disks * sizeof(struct disk_info), 4882 GFP_KERNEL); 4883 if (!conf->disks) 4884 goto abort; 4885 4886 conf->mddev = mddev; 4887 4888 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 4889 goto abort; 4890 4891 conf->level = mddev->new_level; 4892 if (raid5_alloc_percpu(conf) != 0) 4893 goto abort; 4894 4895 pr_debug("raid456: run(%s) called.\n", mdname(mddev)); 4896 4897 rdev_for_each(rdev, mddev) { 4898 raid_disk = rdev->raid_disk; 4899 if (raid_disk >= max_disks 4900 || raid_disk < 0) 4901 continue; 4902 disk = conf->disks + raid_disk; 4903 4904 if (test_bit(Replacement, &rdev->flags)) { 4905 if (disk->replacement) 4906 goto abort; 4907 disk->replacement = rdev; 4908 } else { 4909 if (disk->rdev) 4910 goto abort; 4911 disk->rdev = rdev; 4912 } 4913 4914 if (test_bit(In_sync, &rdev->flags)) { 4915 char b[BDEVNAME_SIZE]; 4916 printk(KERN_INFO "md/raid:%s: device %s operational as raid" 4917 " disk %d\n", 4918 mdname(mddev), bdevname(rdev->bdev, b), raid_disk); 4919 } else if (rdev->saved_raid_disk != raid_disk) 4920 /* Cannot rely on bitmap to complete recovery */ 4921 conf->fullsync = 1; 4922 } 4923 4924 conf->chunk_sectors = mddev->new_chunk_sectors; 4925 conf->level = mddev->new_level; 4926 if (conf->level == 6) 4927 conf->max_degraded = 2; 4928 else 4929 conf->max_degraded = 1; 4930 conf->algorithm = mddev->new_layout; 4931 conf->max_nr_stripes = NR_STRIPES; 4932 conf->reshape_progress = mddev->reshape_position; 4933 if (conf->reshape_progress != MaxSector) { 4934 conf->prev_chunk_sectors = mddev->chunk_sectors; 4935 conf->prev_algo = mddev->layout; 4936 } 4937 4938 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 4939 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; 4940 if (grow_stripes(conf, conf->max_nr_stripes)) { 4941 printk(KERN_ERR 4942 "md/raid:%s: couldn't allocate %dkB for buffers\n", 4943 mdname(mddev), memory); 4944 goto abort; 4945 } else 4946 printk(KERN_INFO "md/raid:%s: allocated %dkB\n", 4947 mdname(mddev), memory); 4948 4949 conf->thread = md_register_thread(raid5d, mddev, NULL); 4950 if (!conf->thread) { 4951 printk(KERN_ERR 4952 "md/raid:%s: couldn't allocate thread.\n", 4953 mdname(mddev)); 4954 goto abort; 4955 } 4956 4957 return conf; 4958 4959 abort: 4960 if (conf) { 4961 free_conf(conf); 4962 return ERR_PTR(-EIO); 4963 } else 4964 return ERR_PTR(-ENOMEM); 4965 } 4966 4967 4968 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) 4969 { 4970 switch (algo) { 4971 case ALGORITHM_PARITY_0: 4972 if (raid_disk < max_degraded) 4973 return 1; 4974 break; 4975 case ALGORITHM_PARITY_N: 4976 if (raid_disk >= raid_disks - max_degraded) 4977 return 1; 4978 break; 4979 case ALGORITHM_PARITY_0_6: 4980 if (raid_disk == 0 || 4981 raid_disk == raid_disks - 1) 4982 return 1; 4983 break; 4984 case ALGORITHM_LEFT_ASYMMETRIC_6: 4985 case ALGORITHM_RIGHT_ASYMMETRIC_6: 4986 case ALGORITHM_LEFT_SYMMETRIC_6: 4987 case ALGORITHM_RIGHT_SYMMETRIC_6: 4988 if (raid_disk == raid_disks - 1) 4989 return 1; 4990 } 4991 return 0; 4992 } 4993 4994 static int run(struct mddev *mddev) 4995 { 4996 struct r5conf *conf; 4997 int working_disks = 0; 4998 int dirty_parity_disks = 0; 4999 struct md_rdev *rdev; 5000 sector_t reshape_offset = 0; 5001 int i; 5002 long long min_offset_diff = 0; 5003 int first = 1; 5004 5005 if (mddev->recovery_cp != MaxSector) 5006 printk(KERN_NOTICE "md/raid:%s: not clean" 5007 " -- starting background reconstruction\n", 5008 mdname(mddev)); 5009 5010 rdev_for_each(rdev, mddev) { 5011 long long diff; 5012 if (rdev->raid_disk < 0) 5013 continue; 5014 diff = (rdev->new_data_offset - rdev->data_offset); 5015 if (first) { 5016 min_offset_diff = diff; 5017 first = 0; 5018 } else if (mddev->reshape_backwards && 5019 diff < min_offset_diff) 5020 min_offset_diff = diff; 5021 else if (!mddev->reshape_backwards && 5022 diff > min_offset_diff) 5023 min_offset_diff = diff; 5024 } 5025 5026 if (mddev->reshape_position != MaxSector) { 5027 /* Check that we can continue the reshape. 5028 * Difficulties arise if the stripe we would write to 5029 * next is at or after the stripe we would read from next. 5030 * For a reshape that changes the number of devices, this 5031 * is only possible for a very short time, and mdadm makes 5032 * sure that time appears to have past before assembling 5033 * the array. So we fail if that time hasn't passed. 5034 * For a reshape that keeps the number of devices the same 5035 * mdadm must be monitoring the reshape can keeping the 5036 * critical areas read-only and backed up. It will start 5037 * the array in read-only mode, so we check for that. 5038 */ 5039 sector_t here_new, here_old; 5040 int old_disks; 5041 int max_degraded = (mddev->level == 6 ? 2 : 1); 5042 5043 if (mddev->new_level != mddev->level) { 5044 printk(KERN_ERR "md/raid:%s: unsupported reshape " 5045 "required - aborting.\n", 5046 mdname(mddev)); 5047 return -EINVAL; 5048 } 5049 old_disks = mddev->raid_disks - mddev->delta_disks; 5050 /* reshape_position must be on a new-stripe boundary, and one 5051 * further up in new geometry must map after here in old 5052 * geometry. 5053 */ 5054 here_new = mddev->reshape_position; 5055 if (sector_div(here_new, mddev->new_chunk_sectors * 5056 (mddev->raid_disks - max_degraded))) { 5057 printk(KERN_ERR "md/raid:%s: reshape_position not " 5058 "on a stripe boundary\n", mdname(mddev)); 5059 return -EINVAL; 5060 } 5061 reshape_offset = here_new * mddev->new_chunk_sectors; 5062 /* here_new is the stripe we will write to */ 5063 here_old = mddev->reshape_position; 5064 sector_div(here_old, mddev->chunk_sectors * 5065 (old_disks-max_degraded)); 5066 /* here_old is the first stripe that we might need to read 5067 * from */ 5068 if (mddev->delta_disks == 0) { 5069 if ((here_new * mddev->new_chunk_sectors != 5070 here_old * mddev->chunk_sectors)) { 5071 printk(KERN_ERR "md/raid:%s: reshape position is" 5072 " confused - aborting\n", mdname(mddev)); 5073 return -EINVAL; 5074 } 5075 /* We cannot be sure it is safe to start an in-place 5076 * reshape. It is only safe if user-space is monitoring 5077 * and taking constant backups. 5078 * mdadm always starts a situation like this in 5079 * readonly mode so it can take control before 5080 * allowing any writes. So just check for that. 5081 */ 5082 if (abs(min_offset_diff) >= mddev->chunk_sectors && 5083 abs(min_offset_diff) >= mddev->new_chunk_sectors) 5084 /* not really in-place - so OK */; 5085 else if (mddev->ro == 0) { 5086 printk(KERN_ERR "md/raid:%s: in-place reshape " 5087 "must be started in read-only mode " 5088 "- aborting\n", 5089 mdname(mddev)); 5090 return -EINVAL; 5091 } 5092 } else if (mddev->reshape_backwards 5093 ? (here_new * mddev->new_chunk_sectors + min_offset_diff <= 5094 here_old * mddev->chunk_sectors) 5095 : (here_new * mddev->new_chunk_sectors >= 5096 here_old * mddev->chunk_sectors + (-min_offset_diff))) { 5097 /* Reading from the same stripe as writing to - bad */ 5098 printk(KERN_ERR "md/raid:%s: reshape_position too early for " 5099 "auto-recovery - aborting.\n", 5100 mdname(mddev)); 5101 return -EINVAL; 5102 } 5103 printk(KERN_INFO "md/raid:%s: reshape will continue\n", 5104 mdname(mddev)); 5105 /* OK, we should be able to continue; */ 5106 } else { 5107 BUG_ON(mddev->level != mddev->new_level); 5108 BUG_ON(mddev->layout != mddev->new_layout); 5109 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); 5110 BUG_ON(mddev->delta_disks != 0); 5111 } 5112 5113 if (mddev->private == NULL) 5114 conf = setup_conf(mddev); 5115 else 5116 conf = mddev->private; 5117 5118 if (IS_ERR(conf)) 5119 return PTR_ERR(conf); 5120 5121 conf->min_offset_diff = min_offset_diff; 5122 mddev->thread = conf->thread; 5123 conf->thread = NULL; 5124 mddev->private = conf; 5125 5126 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks; 5127 i++) { 5128 rdev = conf->disks[i].rdev; 5129 if (!rdev && conf->disks[i].replacement) { 5130 /* The replacement is all we have yet */ 5131 rdev = conf->disks[i].replacement; 5132 conf->disks[i].replacement = NULL; 5133 clear_bit(Replacement, &rdev->flags); 5134 conf->disks[i].rdev = rdev; 5135 } 5136 if (!rdev) 5137 continue; 5138 if (conf->disks[i].replacement && 5139 conf->reshape_progress != MaxSector) { 5140 /* replacements and reshape simply do not mix. */ 5141 printk(KERN_ERR "md: cannot handle concurrent " 5142 "replacement and reshape.\n"); 5143 goto abort; 5144 } 5145 if (test_bit(In_sync, &rdev->flags)) { 5146 working_disks++; 5147 continue; 5148 } 5149 /* This disc is not fully in-sync. However if it 5150 * just stored parity (beyond the recovery_offset), 5151 * when we don't need to be concerned about the 5152 * array being dirty. 5153 * When reshape goes 'backwards', we never have 5154 * partially completed devices, so we only need 5155 * to worry about reshape going forwards. 5156 */ 5157 /* Hack because v0.91 doesn't store recovery_offset properly. */ 5158 if (mddev->major_version == 0 && 5159 mddev->minor_version > 90) 5160 rdev->recovery_offset = reshape_offset; 5161 5162 if (rdev->recovery_offset < reshape_offset) { 5163 /* We need to check old and new layout */ 5164 if (!only_parity(rdev->raid_disk, 5165 conf->algorithm, 5166 conf->raid_disks, 5167 conf->max_degraded)) 5168 continue; 5169 } 5170 if (!only_parity(rdev->raid_disk, 5171 conf->prev_algo, 5172 conf->previous_raid_disks, 5173 conf->max_degraded)) 5174 continue; 5175 dirty_parity_disks++; 5176 } 5177 5178 /* 5179 * 0 for a fully functional array, 1 or 2 for a degraded array. 5180 */ 5181 mddev->degraded = calc_degraded(conf); 5182 5183 if (has_failed(conf)) { 5184 printk(KERN_ERR "md/raid:%s: not enough operational devices" 5185 " (%d/%d failed)\n", 5186 mdname(mddev), mddev->degraded, conf->raid_disks); 5187 goto abort; 5188 } 5189 5190 /* device size must be a multiple of chunk size */ 5191 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); 5192 mddev->resync_max_sectors = mddev->dev_sectors; 5193 5194 if (mddev->degraded > dirty_parity_disks && 5195 mddev->recovery_cp != MaxSector) { 5196 if (mddev->ok_start_degraded) 5197 printk(KERN_WARNING 5198 "md/raid:%s: starting dirty degraded array" 5199 " - data corruption possible.\n", 5200 mdname(mddev)); 5201 else { 5202 printk(KERN_ERR 5203 "md/raid:%s: cannot start dirty degraded array.\n", 5204 mdname(mddev)); 5205 goto abort; 5206 } 5207 } 5208 5209 if (mddev->degraded == 0) 5210 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d" 5211 " devices, algorithm %d\n", mdname(mddev), conf->level, 5212 mddev->raid_disks-mddev->degraded, mddev->raid_disks, 5213 mddev->new_layout); 5214 else 5215 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d" 5216 " out of %d devices, algorithm %d\n", 5217 mdname(mddev), conf->level, 5218 mddev->raid_disks - mddev->degraded, 5219 mddev->raid_disks, mddev->new_layout); 5220 5221 print_raid5_conf(conf); 5222 5223 if (conf->reshape_progress != MaxSector) { 5224 conf->reshape_safe = conf->reshape_progress; 5225 atomic_set(&conf->reshape_stripes, 0); 5226 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 5227 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 5228 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 5229 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 5230 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 5231 "reshape"); 5232 } 5233 5234 5235 /* Ok, everything is just fine now */ 5236 if (mddev->to_remove == &raid5_attrs_group) 5237 mddev->to_remove = NULL; 5238 else if (mddev->kobj.sd && 5239 sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) 5240 printk(KERN_WARNING 5241 "raid5: failed to create sysfs attributes for %s\n", 5242 mdname(mddev)); 5243 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 5244 5245 if (mddev->queue) { 5246 int chunk_size; 5247 /* read-ahead size must cover two whole stripes, which 5248 * is 2 * (datadisks) * chunksize where 'n' is the 5249 * number of raid devices 5250 */ 5251 int data_disks = conf->previous_raid_disks - conf->max_degraded; 5252 int stripe = data_disks * 5253 ((mddev->chunk_sectors << 9) / PAGE_SIZE); 5254 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 5255 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 5256 5257 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); 5258 5259 mddev->queue->backing_dev_info.congested_data = mddev; 5260 mddev->queue->backing_dev_info.congested_fn = raid5_congested; 5261 5262 chunk_size = mddev->chunk_sectors << 9; 5263 blk_queue_io_min(mddev->queue, chunk_size); 5264 blk_queue_io_opt(mddev->queue, chunk_size * 5265 (conf->raid_disks - conf->max_degraded)); 5266 5267 rdev_for_each(rdev, mddev) { 5268 disk_stack_limits(mddev->gendisk, rdev->bdev, 5269 rdev->data_offset << 9); 5270 disk_stack_limits(mddev->gendisk, rdev->bdev, 5271 rdev->new_data_offset << 9); 5272 } 5273 } 5274 5275 return 0; 5276 abort: 5277 md_unregister_thread(&mddev->thread); 5278 print_raid5_conf(conf); 5279 free_conf(conf); 5280 mddev->private = NULL; 5281 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev)); 5282 return -EIO; 5283 } 5284 5285 static int stop(struct mddev *mddev) 5286 { 5287 struct r5conf *conf = mddev->private; 5288 5289 md_unregister_thread(&mddev->thread); 5290 if (mddev->queue) 5291 mddev->queue->backing_dev_info.congested_fn = NULL; 5292 free_conf(conf); 5293 mddev->private = NULL; 5294 mddev->to_remove = &raid5_attrs_group; 5295 return 0; 5296 } 5297 5298 static void status(struct seq_file *seq, struct mddev *mddev) 5299 { 5300 struct r5conf *conf = mddev->private; 5301 int i; 5302 5303 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, 5304 mddev->chunk_sectors / 2, mddev->layout); 5305 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); 5306 for (i = 0; i < conf->raid_disks; i++) 5307 seq_printf (seq, "%s", 5308 conf->disks[i].rdev && 5309 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 5310 seq_printf (seq, "]"); 5311 } 5312 5313 static void print_raid5_conf (struct r5conf *conf) 5314 { 5315 int i; 5316 struct disk_info *tmp; 5317 5318 printk(KERN_DEBUG "RAID conf printout:\n"); 5319 if (!conf) { 5320 printk("(conf==NULL)\n"); 5321 return; 5322 } 5323 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level, 5324 conf->raid_disks, 5325 conf->raid_disks - conf->mddev->degraded); 5326 5327 for (i = 0; i < conf->raid_disks; i++) { 5328 char b[BDEVNAME_SIZE]; 5329 tmp = conf->disks + i; 5330 if (tmp->rdev) 5331 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n", 5332 i, !test_bit(Faulty, &tmp->rdev->flags), 5333 bdevname(tmp->rdev->bdev, b)); 5334 } 5335 } 5336 5337 static int raid5_spare_active(struct mddev *mddev) 5338 { 5339 int i; 5340 struct r5conf *conf = mddev->private; 5341 struct disk_info *tmp; 5342 int count = 0; 5343 unsigned long flags; 5344 5345 for (i = 0; i < conf->raid_disks; i++) { 5346 tmp = conf->disks + i; 5347 if (tmp->replacement 5348 && tmp->replacement->recovery_offset == MaxSector 5349 && !test_bit(Faulty, &tmp->replacement->flags) 5350 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) { 5351 /* Replacement has just become active. */ 5352 if (!tmp->rdev 5353 || !test_and_clear_bit(In_sync, &tmp->rdev->flags)) 5354 count++; 5355 if (tmp->rdev) { 5356 /* Replaced device not technically faulty, 5357 * but we need to be sure it gets removed 5358 * and never re-added. 5359 */ 5360 set_bit(Faulty, &tmp->rdev->flags); 5361 sysfs_notify_dirent_safe( 5362 tmp->rdev->sysfs_state); 5363 } 5364 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state); 5365 } else if (tmp->rdev 5366 && tmp->rdev->recovery_offset == MaxSector 5367 && !test_bit(Faulty, &tmp->rdev->flags) 5368 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { 5369 count++; 5370 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); 5371 } 5372 } 5373 spin_lock_irqsave(&conf->device_lock, flags); 5374 mddev->degraded = calc_degraded(conf); 5375 spin_unlock_irqrestore(&conf->device_lock, flags); 5376 print_raid5_conf(conf); 5377 return count; 5378 } 5379 5380 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) 5381 { 5382 struct r5conf *conf = mddev->private; 5383 int err = 0; 5384 int number = rdev->raid_disk; 5385 struct md_rdev **rdevp; 5386 struct disk_info *p = conf->disks + number; 5387 5388 print_raid5_conf(conf); 5389 if (rdev == p->rdev) 5390 rdevp = &p->rdev; 5391 else if (rdev == p->replacement) 5392 rdevp = &p->replacement; 5393 else 5394 return 0; 5395 5396 if (number >= conf->raid_disks && 5397 conf->reshape_progress == MaxSector) 5398 clear_bit(In_sync, &rdev->flags); 5399 5400 if (test_bit(In_sync, &rdev->flags) || 5401 atomic_read(&rdev->nr_pending)) { 5402 err = -EBUSY; 5403 goto abort; 5404 } 5405 /* Only remove non-faulty devices if recovery 5406 * isn't possible. 5407 */ 5408 if (!test_bit(Faulty, &rdev->flags) && 5409 mddev->recovery_disabled != conf->recovery_disabled && 5410 !has_failed(conf) && 5411 (!p->replacement || p->replacement == rdev) && 5412 number < conf->raid_disks) { 5413 err = -EBUSY; 5414 goto abort; 5415 } 5416 *rdevp = NULL; 5417 synchronize_rcu(); 5418 if (atomic_read(&rdev->nr_pending)) { 5419 /* lost the race, try later */ 5420 err = -EBUSY; 5421 *rdevp = rdev; 5422 } else if (p->replacement) { 5423 /* We must have just cleared 'rdev' */ 5424 p->rdev = p->replacement; 5425 clear_bit(Replacement, &p->replacement->flags); 5426 smp_mb(); /* Make sure other CPUs may see both as identical 5427 * but will never see neither - if they are careful 5428 */ 5429 p->replacement = NULL; 5430 clear_bit(WantReplacement, &rdev->flags); 5431 } else 5432 /* We might have just removed the Replacement as faulty- 5433 * clear the bit just in case 5434 */ 5435 clear_bit(WantReplacement, &rdev->flags); 5436 abort: 5437 5438 print_raid5_conf(conf); 5439 return err; 5440 } 5441 5442 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev) 5443 { 5444 struct r5conf *conf = mddev->private; 5445 int err = -EEXIST; 5446 int disk; 5447 struct disk_info *p; 5448 int first = 0; 5449 int last = conf->raid_disks - 1; 5450 5451 if (mddev->recovery_disabled == conf->recovery_disabled) 5452 return -EBUSY; 5453 5454 if (rdev->saved_raid_disk < 0 && has_failed(conf)) 5455 /* no point adding a device */ 5456 return -EINVAL; 5457 5458 if (rdev->raid_disk >= 0) 5459 first = last = rdev->raid_disk; 5460 5461 /* 5462 * find the disk ... but prefer rdev->saved_raid_disk 5463 * if possible. 5464 */ 5465 if (rdev->saved_raid_disk >= 0 && 5466 rdev->saved_raid_disk >= first && 5467 conf->disks[rdev->saved_raid_disk].rdev == NULL) 5468 disk = rdev->saved_raid_disk; 5469 else 5470 disk = first; 5471 for ( ; disk <= last ; disk++) { 5472 p = conf->disks + disk; 5473 if (p->rdev == NULL) { 5474 clear_bit(In_sync, &rdev->flags); 5475 rdev->raid_disk = disk; 5476 err = 0; 5477 if (rdev->saved_raid_disk != disk) 5478 conf->fullsync = 1; 5479 rcu_assign_pointer(p->rdev, rdev); 5480 break; 5481 } 5482 if (test_bit(WantReplacement, &p->rdev->flags) && 5483 p->replacement == NULL) { 5484 clear_bit(In_sync, &rdev->flags); 5485 set_bit(Replacement, &rdev->flags); 5486 rdev->raid_disk = disk; 5487 err = 0; 5488 conf->fullsync = 1; 5489 rcu_assign_pointer(p->replacement, rdev); 5490 break; 5491 } 5492 } 5493 print_raid5_conf(conf); 5494 return err; 5495 } 5496 5497 static int raid5_resize(struct mddev *mddev, sector_t sectors) 5498 { 5499 /* no resync is happening, and there is enough space 5500 * on all devices, so we can resize. 5501 * We need to make sure resync covers any new space. 5502 * If the array is shrinking we should possibly wait until 5503 * any io in the removed space completes, but it hardly seems 5504 * worth it. 5505 */ 5506 sector_t newsize; 5507 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 5508 newsize = raid5_size(mddev, sectors, mddev->raid_disks); 5509 if (mddev->external_size && 5510 mddev->array_sectors > newsize) 5511 return -EINVAL; 5512 if (mddev->bitmap) { 5513 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0); 5514 if (ret) 5515 return ret; 5516 } 5517 md_set_array_sectors(mddev, newsize); 5518 set_capacity(mddev->gendisk, mddev->array_sectors); 5519 revalidate_disk(mddev->gendisk); 5520 if (sectors > mddev->dev_sectors && 5521 mddev->recovery_cp > mddev->dev_sectors) { 5522 mddev->recovery_cp = mddev->dev_sectors; 5523 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 5524 } 5525 mddev->dev_sectors = sectors; 5526 mddev->resync_max_sectors = sectors; 5527 return 0; 5528 } 5529 5530 static int check_stripe_cache(struct mddev *mddev) 5531 { 5532 /* Can only proceed if there are plenty of stripe_heads. 5533 * We need a minimum of one full stripe,, and for sensible progress 5534 * it is best to have about 4 times that. 5535 * If we require 4 times, then the default 256 4K stripe_heads will 5536 * allow for chunk sizes up to 256K, which is probably OK. 5537 * If the chunk size is greater, user-space should request more 5538 * stripe_heads first. 5539 */ 5540 struct r5conf *conf = mddev->private; 5541 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 5542 > conf->max_nr_stripes || 5543 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 5544 > conf->max_nr_stripes) { 5545 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n", 5546 mdname(mddev), 5547 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) 5548 / STRIPE_SIZE)*4); 5549 return 0; 5550 } 5551 return 1; 5552 } 5553 5554 static int check_reshape(struct mddev *mddev) 5555 { 5556 struct r5conf *conf = mddev->private; 5557 5558 if (mddev->delta_disks == 0 && 5559 mddev->new_layout == mddev->layout && 5560 mddev->new_chunk_sectors == mddev->chunk_sectors) 5561 return 0; /* nothing to do */ 5562 if (has_failed(conf)) 5563 return -EINVAL; 5564 if (mddev->delta_disks < 0) { 5565 /* We might be able to shrink, but the devices must 5566 * be made bigger first. 5567 * For raid6, 4 is the minimum size. 5568 * Otherwise 2 is the minimum 5569 */ 5570 int min = 2; 5571 if (mddev->level == 6) 5572 min = 4; 5573 if (mddev->raid_disks + mddev->delta_disks < min) 5574 return -EINVAL; 5575 } 5576 5577 if (!check_stripe_cache(mddev)) 5578 return -ENOSPC; 5579 5580 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); 5581 } 5582 5583 static int raid5_start_reshape(struct mddev *mddev) 5584 { 5585 struct r5conf *conf = mddev->private; 5586 struct md_rdev *rdev; 5587 int spares = 0; 5588 unsigned long flags; 5589 5590 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 5591 return -EBUSY; 5592 5593 if (!check_stripe_cache(mddev)) 5594 return -ENOSPC; 5595 5596 if (has_failed(conf)) 5597 return -EINVAL; 5598 5599 rdev_for_each(rdev, mddev) { 5600 if (!test_bit(In_sync, &rdev->flags) 5601 && !test_bit(Faulty, &rdev->flags)) 5602 spares++; 5603 } 5604 5605 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) 5606 /* Not enough devices even to make a degraded array 5607 * of that size 5608 */ 5609 return -EINVAL; 5610 5611 /* Refuse to reduce size of the array. Any reductions in 5612 * array size must be through explicit setting of array_size 5613 * attribute. 5614 */ 5615 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) 5616 < mddev->array_sectors) { 5617 printk(KERN_ERR "md/raid:%s: array size must be reduced " 5618 "before number of disks\n", mdname(mddev)); 5619 return -EINVAL; 5620 } 5621 5622 atomic_set(&conf->reshape_stripes, 0); 5623 spin_lock_irq(&conf->device_lock); 5624 conf->previous_raid_disks = conf->raid_disks; 5625 conf->raid_disks += mddev->delta_disks; 5626 conf->prev_chunk_sectors = conf->chunk_sectors; 5627 conf->chunk_sectors = mddev->new_chunk_sectors; 5628 conf->prev_algo = conf->algorithm; 5629 conf->algorithm = mddev->new_layout; 5630 conf->generation++; 5631 /* Code that selects data_offset needs to see the generation update 5632 * if reshape_progress has been set - so a memory barrier needed. 5633 */ 5634 smp_mb(); 5635 if (mddev->reshape_backwards) 5636 conf->reshape_progress = raid5_size(mddev, 0, 0); 5637 else 5638 conf->reshape_progress = 0; 5639 conf->reshape_safe = conf->reshape_progress; 5640 spin_unlock_irq(&conf->device_lock); 5641 5642 /* Add some new drives, as many as will fit. 5643 * We know there are enough to make the newly sized array work. 5644 * Don't add devices if we are reducing the number of 5645 * devices in the array. This is because it is not possible 5646 * to correctly record the "partially reconstructed" state of 5647 * such devices during the reshape and confusion could result. 5648 */ 5649 if (mddev->delta_disks >= 0) { 5650 rdev_for_each(rdev, mddev) 5651 if (rdev->raid_disk < 0 && 5652 !test_bit(Faulty, &rdev->flags)) { 5653 if (raid5_add_disk(mddev, rdev) == 0) { 5654 if (rdev->raid_disk 5655 >= conf->previous_raid_disks) 5656 set_bit(In_sync, &rdev->flags); 5657 else 5658 rdev->recovery_offset = 0; 5659 5660 if (sysfs_link_rdev(mddev, rdev)) 5661 /* Failure here is OK */; 5662 } 5663 } else if (rdev->raid_disk >= conf->previous_raid_disks 5664 && !test_bit(Faulty, &rdev->flags)) { 5665 /* This is a spare that was manually added */ 5666 set_bit(In_sync, &rdev->flags); 5667 } 5668 5669 /* When a reshape changes the number of devices, 5670 * ->degraded is measured against the larger of the 5671 * pre and post number of devices. 5672 */ 5673 spin_lock_irqsave(&conf->device_lock, flags); 5674 mddev->degraded = calc_degraded(conf); 5675 spin_unlock_irqrestore(&conf->device_lock, flags); 5676 } 5677 mddev->raid_disks = conf->raid_disks; 5678 mddev->reshape_position = conf->reshape_progress; 5679 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5680 5681 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 5682 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 5683 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 5684 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 5685 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 5686 "reshape"); 5687 if (!mddev->sync_thread) { 5688 mddev->recovery = 0; 5689 spin_lock_irq(&conf->device_lock); 5690 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; 5691 rdev_for_each(rdev, mddev) 5692 rdev->new_data_offset = rdev->data_offset; 5693 smp_wmb(); 5694 conf->reshape_progress = MaxSector; 5695 mddev->reshape_position = MaxSector; 5696 spin_unlock_irq(&conf->device_lock); 5697 return -EAGAIN; 5698 } 5699 conf->reshape_checkpoint = jiffies; 5700 md_wakeup_thread(mddev->sync_thread); 5701 md_new_event(mddev); 5702 return 0; 5703 } 5704 5705 /* This is called from the reshape thread and should make any 5706 * changes needed in 'conf' 5707 */ 5708 static void end_reshape(struct r5conf *conf) 5709 { 5710 5711 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { 5712 struct md_rdev *rdev; 5713 5714 spin_lock_irq(&conf->device_lock); 5715 conf->previous_raid_disks = conf->raid_disks; 5716 rdev_for_each(rdev, conf->mddev) 5717 rdev->data_offset = rdev->new_data_offset; 5718 smp_wmb(); 5719 conf->reshape_progress = MaxSector; 5720 spin_unlock_irq(&conf->device_lock); 5721 wake_up(&conf->wait_for_overlap); 5722 5723 /* read-ahead size must cover two whole stripes, which is 5724 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 5725 */ 5726 if (conf->mddev->queue) { 5727 int data_disks = conf->raid_disks - conf->max_degraded; 5728 int stripe = data_disks * ((conf->chunk_sectors << 9) 5729 / PAGE_SIZE); 5730 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 5731 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 5732 } 5733 } 5734 } 5735 5736 /* This is called from the raid5d thread with mddev_lock held. 5737 * It makes config changes to the device. 5738 */ 5739 static void raid5_finish_reshape(struct mddev *mddev) 5740 { 5741 struct r5conf *conf = mddev->private; 5742 5743 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { 5744 5745 if (mddev->delta_disks > 0) { 5746 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 5747 set_capacity(mddev->gendisk, mddev->array_sectors); 5748 revalidate_disk(mddev->gendisk); 5749 } else { 5750 int d; 5751 spin_lock_irq(&conf->device_lock); 5752 mddev->degraded = calc_degraded(conf); 5753 spin_unlock_irq(&conf->device_lock); 5754 for (d = conf->raid_disks ; 5755 d < conf->raid_disks - mddev->delta_disks; 5756 d++) { 5757 struct md_rdev *rdev = conf->disks[d].rdev; 5758 if (rdev) 5759 clear_bit(In_sync, &rdev->flags); 5760 rdev = conf->disks[d].replacement; 5761 if (rdev) 5762 clear_bit(In_sync, &rdev->flags); 5763 } 5764 } 5765 mddev->layout = conf->algorithm; 5766 mddev->chunk_sectors = conf->chunk_sectors; 5767 mddev->reshape_position = MaxSector; 5768 mddev->delta_disks = 0; 5769 mddev->reshape_backwards = 0; 5770 } 5771 } 5772 5773 static void raid5_quiesce(struct mddev *mddev, int state) 5774 { 5775 struct r5conf *conf = mddev->private; 5776 5777 switch(state) { 5778 case 2: /* resume for a suspend */ 5779 wake_up(&conf->wait_for_overlap); 5780 break; 5781 5782 case 1: /* stop all writes */ 5783 spin_lock_irq(&conf->device_lock); 5784 /* '2' tells resync/reshape to pause so that all 5785 * active stripes can drain 5786 */ 5787 conf->quiesce = 2; 5788 wait_event_lock_irq(conf->wait_for_stripe, 5789 atomic_read(&conf->active_stripes) == 0 && 5790 atomic_read(&conf->active_aligned_reads) == 0, 5791 conf->device_lock, /* nothing */); 5792 conf->quiesce = 1; 5793 spin_unlock_irq(&conf->device_lock); 5794 /* allow reshape to continue */ 5795 wake_up(&conf->wait_for_overlap); 5796 break; 5797 5798 case 0: /* re-enable writes */ 5799 spin_lock_irq(&conf->device_lock); 5800 conf->quiesce = 0; 5801 wake_up(&conf->wait_for_stripe); 5802 wake_up(&conf->wait_for_overlap); 5803 spin_unlock_irq(&conf->device_lock); 5804 break; 5805 } 5806 } 5807 5808 5809 static void *raid45_takeover_raid0(struct mddev *mddev, int level) 5810 { 5811 struct r0conf *raid0_conf = mddev->private; 5812 sector_t sectors; 5813 5814 /* for raid0 takeover only one zone is supported */ 5815 if (raid0_conf->nr_strip_zones > 1) { 5816 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n", 5817 mdname(mddev)); 5818 return ERR_PTR(-EINVAL); 5819 } 5820 5821 sectors = raid0_conf->strip_zone[0].zone_end; 5822 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev); 5823 mddev->dev_sectors = sectors; 5824 mddev->new_level = level; 5825 mddev->new_layout = ALGORITHM_PARITY_N; 5826 mddev->new_chunk_sectors = mddev->chunk_sectors; 5827 mddev->raid_disks += 1; 5828 mddev->delta_disks = 1; 5829 /* make sure it will be not marked as dirty */ 5830 mddev->recovery_cp = MaxSector; 5831 5832 return setup_conf(mddev); 5833 } 5834 5835 5836 static void *raid5_takeover_raid1(struct mddev *mddev) 5837 { 5838 int chunksect; 5839 5840 if (mddev->raid_disks != 2 || 5841 mddev->degraded > 1) 5842 return ERR_PTR(-EINVAL); 5843 5844 /* Should check if there are write-behind devices? */ 5845 5846 chunksect = 64*2; /* 64K by default */ 5847 5848 /* The array must be an exact multiple of chunksize */ 5849 while (chunksect && (mddev->array_sectors & (chunksect-1))) 5850 chunksect >>= 1; 5851 5852 if ((chunksect<<9) < STRIPE_SIZE) 5853 /* array size does not allow a suitable chunk size */ 5854 return ERR_PTR(-EINVAL); 5855 5856 mddev->new_level = 5; 5857 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; 5858 mddev->new_chunk_sectors = chunksect; 5859 5860 return setup_conf(mddev); 5861 } 5862 5863 static void *raid5_takeover_raid6(struct mddev *mddev) 5864 { 5865 int new_layout; 5866 5867 switch (mddev->layout) { 5868 case ALGORITHM_LEFT_ASYMMETRIC_6: 5869 new_layout = ALGORITHM_LEFT_ASYMMETRIC; 5870 break; 5871 case ALGORITHM_RIGHT_ASYMMETRIC_6: 5872 new_layout = ALGORITHM_RIGHT_ASYMMETRIC; 5873 break; 5874 case ALGORITHM_LEFT_SYMMETRIC_6: 5875 new_layout = ALGORITHM_LEFT_SYMMETRIC; 5876 break; 5877 case ALGORITHM_RIGHT_SYMMETRIC_6: 5878 new_layout = ALGORITHM_RIGHT_SYMMETRIC; 5879 break; 5880 case ALGORITHM_PARITY_0_6: 5881 new_layout = ALGORITHM_PARITY_0; 5882 break; 5883 case ALGORITHM_PARITY_N: 5884 new_layout = ALGORITHM_PARITY_N; 5885 break; 5886 default: 5887 return ERR_PTR(-EINVAL); 5888 } 5889 mddev->new_level = 5; 5890 mddev->new_layout = new_layout; 5891 mddev->delta_disks = -1; 5892 mddev->raid_disks -= 1; 5893 return setup_conf(mddev); 5894 } 5895 5896 5897 static int raid5_check_reshape(struct mddev *mddev) 5898 { 5899 /* For a 2-drive array, the layout and chunk size can be changed 5900 * immediately as not restriping is needed. 5901 * For larger arrays we record the new value - after validation 5902 * to be used by a reshape pass. 5903 */ 5904 struct r5conf *conf = mddev->private; 5905 int new_chunk = mddev->new_chunk_sectors; 5906 5907 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) 5908 return -EINVAL; 5909 if (new_chunk > 0) { 5910 if (!is_power_of_2(new_chunk)) 5911 return -EINVAL; 5912 if (new_chunk < (PAGE_SIZE>>9)) 5913 return -EINVAL; 5914 if (mddev->array_sectors & (new_chunk-1)) 5915 /* not factor of array size */ 5916 return -EINVAL; 5917 } 5918 5919 /* They look valid */ 5920 5921 if (mddev->raid_disks == 2) { 5922 /* can make the change immediately */ 5923 if (mddev->new_layout >= 0) { 5924 conf->algorithm = mddev->new_layout; 5925 mddev->layout = mddev->new_layout; 5926 } 5927 if (new_chunk > 0) { 5928 conf->chunk_sectors = new_chunk ; 5929 mddev->chunk_sectors = new_chunk; 5930 } 5931 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5932 md_wakeup_thread(mddev->thread); 5933 } 5934 return check_reshape(mddev); 5935 } 5936 5937 static int raid6_check_reshape(struct mddev *mddev) 5938 { 5939 int new_chunk = mddev->new_chunk_sectors; 5940 5941 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) 5942 return -EINVAL; 5943 if (new_chunk > 0) { 5944 if (!is_power_of_2(new_chunk)) 5945 return -EINVAL; 5946 if (new_chunk < (PAGE_SIZE >> 9)) 5947 return -EINVAL; 5948 if (mddev->array_sectors & (new_chunk-1)) 5949 /* not factor of array size */ 5950 return -EINVAL; 5951 } 5952 5953 /* They look valid */ 5954 return check_reshape(mddev); 5955 } 5956 5957 static void *raid5_takeover(struct mddev *mddev) 5958 { 5959 /* raid5 can take over: 5960 * raid0 - if there is only one strip zone - make it a raid4 layout 5961 * raid1 - if there are two drives. We need to know the chunk size 5962 * raid4 - trivial - just use a raid4 layout. 5963 * raid6 - Providing it is a *_6 layout 5964 */ 5965 if (mddev->level == 0) 5966 return raid45_takeover_raid0(mddev, 5); 5967 if (mddev->level == 1) 5968 return raid5_takeover_raid1(mddev); 5969 if (mddev->level == 4) { 5970 mddev->new_layout = ALGORITHM_PARITY_N; 5971 mddev->new_level = 5; 5972 return setup_conf(mddev); 5973 } 5974 if (mddev->level == 6) 5975 return raid5_takeover_raid6(mddev); 5976 5977 return ERR_PTR(-EINVAL); 5978 } 5979 5980 static void *raid4_takeover(struct mddev *mddev) 5981 { 5982 /* raid4 can take over: 5983 * raid0 - if there is only one strip zone 5984 * raid5 - if layout is right 5985 */ 5986 if (mddev->level == 0) 5987 return raid45_takeover_raid0(mddev, 4); 5988 if (mddev->level == 5 && 5989 mddev->layout == ALGORITHM_PARITY_N) { 5990 mddev->new_layout = 0; 5991 mddev->new_level = 4; 5992 return setup_conf(mddev); 5993 } 5994 return ERR_PTR(-EINVAL); 5995 } 5996 5997 static struct md_personality raid5_personality; 5998 5999 static void *raid6_takeover(struct mddev *mddev) 6000 { 6001 /* Currently can only take over a raid5. We map the 6002 * personality to an equivalent raid6 personality 6003 * with the Q block at the end. 6004 */ 6005 int new_layout; 6006 6007 if (mddev->pers != &raid5_personality) 6008 return ERR_PTR(-EINVAL); 6009 if (mddev->degraded > 1) 6010 return ERR_PTR(-EINVAL); 6011 if (mddev->raid_disks > 253) 6012 return ERR_PTR(-EINVAL); 6013 if (mddev->raid_disks < 3) 6014 return ERR_PTR(-EINVAL); 6015 6016 switch (mddev->layout) { 6017 case ALGORITHM_LEFT_ASYMMETRIC: 6018 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; 6019 break; 6020 case ALGORITHM_RIGHT_ASYMMETRIC: 6021 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; 6022 break; 6023 case ALGORITHM_LEFT_SYMMETRIC: 6024 new_layout = ALGORITHM_LEFT_SYMMETRIC_6; 6025 break; 6026 case ALGORITHM_RIGHT_SYMMETRIC: 6027 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; 6028 break; 6029 case ALGORITHM_PARITY_0: 6030 new_layout = ALGORITHM_PARITY_0_6; 6031 break; 6032 case ALGORITHM_PARITY_N: 6033 new_layout = ALGORITHM_PARITY_N; 6034 break; 6035 default: 6036 return ERR_PTR(-EINVAL); 6037 } 6038 mddev->new_level = 6; 6039 mddev->new_layout = new_layout; 6040 mddev->delta_disks = 1; 6041 mddev->raid_disks += 1; 6042 return setup_conf(mddev); 6043 } 6044 6045 6046 static struct md_personality raid6_personality = 6047 { 6048 .name = "raid6", 6049 .level = 6, 6050 .owner = THIS_MODULE, 6051 .make_request = make_request, 6052 .run = run, 6053 .stop = stop, 6054 .status = status, 6055 .error_handler = error, 6056 .hot_add_disk = raid5_add_disk, 6057 .hot_remove_disk= raid5_remove_disk, 6058 .spare_active = raid5_spare_active, 6059 .sync_request = sync_request, 6060 .resize = raid5_resize, 6061 .size = raid5_size, 6062 .check_reshape = raid6_check_reshape, 6063 .start_reshape = raid5_start_reshape, 6064 .finish_reshape = raid5_finish_reshape, 6065 .quiesce = raid5_quiesce, 6066 .takeover = raid6_takeover, 6067 }; 6068 static struct md_personality raid5_personality = 6069 { 6070 .name = "raid5", 6071 .level = 5, 6072 .owner = THIS_MODULE, 6073 .make_request = make_request, 6074 .run = run, 6075 .stop = stop, 6076 .status = status, 6077 .error_handler = error, 6078 .hot_add_disk = raid5_add_disk, 6079 .hot_remove_disk= raid5_remove_disk, 6080 .spare_active = raid5_spare_active, 6081 .sync_request = sync_request, 6082 .resize = raid5_resize, 6083 .size = raid5_size, 6084 .check_reshape = raid5_check_reshape, 6085 .start_reshape = raid5_start_reshape, 6086 .finish_reshape = raid5_finish_reshape, 6087 .quiesce = raid5_quiesce, 6088 .takeover = raid5_takeover, 6089 }; 6090 6091 static struct md_personality raid4_personality = 6092 { 6093 .name = "raid4", 6094 .level = 4, 6095 .owner = THIS_MODULE, 6096 .make_request = make_request, 6097 .run = run, 6098 .stop = stop, 6099 .status = status, 6100 .error_handler = error, 6101 .hot_add_disk = raid5_add_disk, 6102 .hot_remove_disk= raid5_remove_disk, 6103 .spare_active = raid5_spare_active, 6104 .sync_request = sync_request, 6105 .resize = raid5_resize, 6106 .size = raid5_size, 6107 .check_reshape = raid5_check_reshape, 6108 .start_reshape = raid5_start_reshape, 6109 .finish_reshape = raid5_finish_reshape, 6110 .quiesce = raid5_quiesce, 6111 .takeover = raid4_takeover, 6112 }; 6113 6114 static int __init raid5_init(void) 6115 { 6116 register_md_personality(&raid6_personality); 6117 register_md_personality(&raid5_personality); 6118 register_md_personality(&raid4_personality); 6119 return 0; 6120 } 6121 6122 static void raid5_exit(void) 6123 { 6124 unregister_md_personality(&raid6_personality); 6125 unregister_md_personality(&raid5_personality); 6126 unregister_md_personality(&raid4_personality); 6127 } 6128 6129 module_init(raid5_init); 6130 module_exit(raid5_exit); 6131 MODULE_LICENSE("GPL"); 6132 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD"); 6133 MODULE_ALIAS("md-personality-4"); /* RAID5 */ 6134 MODULE_ALIAS("md-raid5"); 6135 MODULE_ALIAS("md-raid4"); 6136 MODULE_ALIAS("md-level-5"); 6137 MODULE_ALIAS("md-level-4"); 6138 MODULE_ALIAS("md-personality-8"); /* RAID6 */ 6139 MODULE_ALIAS("md-raid6"); 6140 MODULE_ALIAS("md-level-6"); 6141 6142 /* This used to be two separate modules, they were: */ 6143 MODULE_ALIAS("raid5"); 6144 MODULE_ALIAS("raid6"); 6145