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