1 /* 2 * raid5.c : Multiple Devices driver for Linux 3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman 4 * Copyright (C) 1999, 2000 Ingo Molnar 5 * Copyright (C) 2002, 2003 H. Peter Anvin 6 * 7 * RAID-4/5/6 management functions. 8 * Thanks to Penguin Computing for making the RAID-6 development possible 9 * by donating a test server! 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2, or (at your option) 14 * any later version. 15 * 16 * You should have received a copy of the GNU General Public License 17 * (for example /usr/src/linux/COPYING); if not, write to the Free 18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 /* 22 * BITMAP UNPLUGGING: 23 * 24 * The sequencing for updating the bitmap reliably is a little 25 * subtle (and I got it wrong the first time) so it deserves some 26 * explanation. 27 * 28 * We group bitmap updates into batches. Each batch has a number. 29 * We may write out several batches at once, but that isn't very important. 30 * conf->seq_write is the number of the last batch successfully written. 31 * conf->seq_flush is the number of the last batch that was closed to 32 * new additions. 33 * When we discover that we will need to write to any block in a stripe 34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq 35 * the number of the batch it will be in. This is seq_flush+1. 36 * When we are ready to do a write, if that batch hasn't been written yet, 37 * we plug the array and queue the stripe for later. 38 * When an unplug happens, we increment bm_flush, thus closing the current 39 * batch. 40 * When we notice that bm_flush > bm_write, we write out all pending updates 41 * to the bitmap, and advance bm_write to where bm_flush was. 42 * This may occasionally write a bit out twice, but is sure never to 43 * miss any bits. 44 */ 45 46 #include <linux/blkdev.h> 47 #include <linux/kthread.h> 48 #include <linux/raid/pq.h> 49 #include <linux/async_tx.h> 50 #include <linux/async.h> 51 #include <linux/seq_file.h> 52 #include <linux/cpu.h> 53 #include <linux/slab.h> 54 #include <linux/ratelimit.h> 55 #include "md.h" 56 #include "raid5.h" 57 #include "raid0.h" 58 #include "bitmap.h" 59 60 /* 61 * Stripe cache 62 */ 63 64 #define NR_STRIPES 256 65 #define STRIPE_SIZE PAGE_SIZE 66 #define STRIPE_SHIFT (PAGE_SHIFT - 9) 67 #define STRIPE_SECTORS (STRIPE_SIZE>>9) 68 #define IO_THRESHOLD 1 69 #define BYPASS_THRESHOLD 1 70 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head)) 71 #define HASH_MASK (NR_HASH - 1) 72 73 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])) 74 75 /* bio's attached to a stripe+device for I/O are linked together in bi_sector 76 * order without overlap. There may be several bio's per stripe+device, and 77 * a bio could span several devices. 78 * When walking this list for a particular stripe+device, we must never proceed 79 * beyond a bio that extends past this device, as the next bio might no longer 80 * be valid. 81 * This macro is used to determine the 'next' bio in the list, given the sector 82 * of the current stripe+device 83 */ 84 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL) 85 /* 86 * The following can be used to debug the driver 87 */ 88 #define RAID5_PARANOIA 1 89 #if RAID5_PARANOIA && defined(CONFIG_SMP) 90 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) 91 #else 92 # define CHECK_DEVLOCK() 93 #endif 94 95 #ifdef DEBUG 96 #define inline 97 #define __inline__ 98 #endif 99 100 /* 101 * We maintain a biased count of active stripes in the bottom 16 bits of 102 * bi_phys_segments, and a count of processed stripes in the upper 16 bits 103 */ 104 static inline int raid5_bi_phys_segments(struct bio *bio) 105 { 106 return bio->bi_phys_segments & 0xffff; 107 } 108 109 static inline int raid5_bi_hw_segments(struct bio *bio) 110 { 111 return (bio->bi_phys_segments >> 16) & 0xffff; 112 } 113 114 static inline int raid5_dec_bi_phys_segments(struct bio *bio) 115 { 116 --bio->bi_phys_segments; 117 return raid5_bi_phys_segments(bio); 118 } 119 120 static inline int raid5_dec_bi_hw_segments(struct bio *bio) 121 { 122 unsigned short val = raid5_bi_hw_segments(bio); 123 124 --val; 125 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); 126 return val; 127 } 128 129 static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) 130 { 131 bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16); 132 } 133 134 /* Find first data disk in a raid6 stripe */ 135 static inline int raid6_d0(struct stripe_head *sh) 136 { 137 if (sh->ddf_layout) 138 /* ddf always start from first device */ 139 return 0; 140 /* md starts just after Q block */ 141 if (sh->qd_idx == sh->disks - 1) 142 return 0; 143 else 144 return sh->qd_idx + 1; 145 } 146 static inline int raid6_next_disk(int disk, int raid_disks) 147 { 148 disk++; 149 return (disk < raid_disks) ? disk : 0; 150 } 151 152 /* When walking through the disks in a raid5, starting at raid6_d0, 153 * We need to map each disk to a 'slot', where the data disks are slot 154 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk 155 * is raid_disks-1. This help does that mapping. 156 */ 157 static int raid6_idx_to_slot(int idx, struct stripe_head *sh, 158 int *count, int syndrome_disks) 159 { 160 int slot = *count; 161 162 if (sh->ddf_layout) 163 (*count)++; 164 if (idx == sh->pd_idx) 165 return syndrome_disks; 166 if (idx == sh->qd_idx) 167 return syndrome_disks + 1; 168 if (!sh->ddf_layout) 169 (*count)++; 170 return slot; 171 } 172 173 static void return_io(struct bio *return_bi) 174 { 175 struct bio *bi = return_bi; 176 while (bi) { 177 178 return_bi = bi->bi_next; 179 bi->bi_next = NULL; 180 bi->bi_size = 0; 181 bio_endio(bi, 0); 182 bi = return_bi; 183 } 184 } 185 186 static void print_raid5_conf (raid5_conf_t *conf); 187 188 static int stripe_operations_active(struct stripe_head *sh) 189 { 190 return sh->check_state || sh->reconstruct_state || 191 test_bit(STRIPE_BIOFILL_RUN, &sh->state) || 192 test_bit(STRIPE_COMPUTE_RUN, &sh->state); 193 } 194 195 static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) 196 { 197 if (atomic_dec_and_test(&sh->count)) { 198 BUG_ON(!list_empty(&sh->lru)); 199 BUG_ON(atomic_read(&conf->active_stripes)==0); 200 if (test_bit(STRIPE_HANDLE, &sh->state)) { 201 if (test_bit(STRIPE_DELAYED, &sh->state)) 202 list_add_tail(&sh->lru, &conf->delayed_list); 203 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && 204 sh->bm_seq - conf->seq_write > 0) 205 list_add_tail(&sh->lru, &conf->bitmap_list); 206 else { 207 clear_bit(STRIPE_BIT_DELAY, &sh->state); 208 list_add_tail(&sh->lru, &conf->handle_list); 209 } 210 md_wakeup_thread(conf->mddev->thread); 211 } else { 212 BUG_ON(stripe_operations_active(sh)); 213 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 214 atomic_dec(&conf->preread_active_stripes); 215 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) 216 md_wakeup_thread(conf->mddev->thread); 217 } 218 atomic_dec(&conf->active_stripes); 219 if (!test_bit(STRIPE_EXPANDING, &sh->state)) { 220 list_add_tail(&sh->lru, &conf->inactive_list); 221 wake_up(&conf->wait_for_stripe); 222 if (conf->retry_read_aligned) 223 md_wakeup_thread(conf->mddev->thread); 224 } 225 } 226 } 227 } 228 229 static void release_stripe(struct stripe_head *sh) 230 { 231 raid5_conf_t *conf = sh->raid_conf; 232 unsigned long flags; 233 234 spin_lock_irqsave(&conf->device_lock, flags); 235 __release_stripe(conf, sh); 236 spin_unlock_irqrestore(&conf->device_lock, flags); 237 } 238 239 static inline void remove_hash(struct stripe_head *sh) 240 { 241 pr_debug("remove_hash(), stripe %llu\n", 242 (unsigned long long)sh->sector); 243 244 hlist_del_init(&sh->hash); 245 } 246 247 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) 248 { 249 struct hlist_head *hp = stripe_hash(conf, sh->sector); 250 251 pr_debug("insert_hash(), stripe %llu\n", 252 (unsigned long long)sh->sector); 253 254 CHECK_DEVLOCK(); 255 hlist_add_head(&sh->hash, hp); 256 } 257 258 259 /* find an idle stripe, make sure it is unhashed, and return it. */ 260 static struct stripe_head *get_free_stripe(raid5_conf_t *conf) 261 { 262 struct stripe_head *sh = NULL; 263 struct list_head *first; 264 265 CHECK_DEVLOCK(); 266 if (list_empty(&conf->inactive_list)) 267 goto out; 268 first = conf->inactive_list.next; 269 sh = list_entry(first, struct stripe_head, lru); 270 list_del_init(first); 271 remove_hash(sh); 272 atomic_inc(&conf->active_stripes); 273 out: 274 return sh; 275 } 276 277 static void shrink_buffers(struct stripe_head *sh) 278 { 279 struct page *p; 280 int i; 281 int num = sh->raid_conf->pool_size; 282 283 for (i = 0; i < num ; i++) { 284 p = sh->dev[i].page; 285 if (!p) 286 continue; 287 sh->dev[i].page = NULL; 288 put_page(p); 289 } 290 } 291 292 static int grow_buffers(struct stripe_head *sh) 293 { 294 int i; 295 int num = sh->raid_conf->pool_size; 296 297 for (i = 0; i < num; i++) { 298 struct page *page; 299 300 if (!(page = alloc_page(GFP_KERNEL))) { 301 return 1; 302 } 303 sh->dev[i].page = page; 304 } 305 return 0; 306 } 307 308 static void raid5_build_block(struct stripe_head *sh, int i, int previous); 309 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, 310 struct stripe_head *sh); 311 312 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) 313 { 314 raid5_conf_t *conf = sh->raid_conf; 315 int i; 316 317 BUG_ON(atomic_read(&sh->count) != 0); 318 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); 319 BUG_ON(stripe_operations_active(sh)); 320 321 CHECK_DEVLOCK(); 322 pr_debug("init_stripe called, stripe %llu\n", 323 (unsigned long long)sh->sector); 324 325 remove_hash(sh); 326 327 sh->generation = conf->generation - previous; 328 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; 329 sh->sector = sector; 330 stripe_set_idx(sector, conf, previous, sh); 331 sh->state = 0; 332 333 334 for (i = sh->disks; i--; ) { 335 struct r5dev *dev = &sh->dev[i]; 336 337 if (dev->toread || dev->read || dev->towrite || dev->written || 338 test_bit(R5_LOCKED, &dev->flags)) { 339 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n", 340 (unsigned long long)sh->sector, i, dev->toread, 341 dev->read, dev->towrite, dev->written, 342 test_bit(R5_LOCKED, &dev->flags)); 343 WARN_ON(1); 344 } 345 dev->flags = 0; 346 raid5_build_block(sh, i, previous); 347 } 348 insert_hash(conf, sh); 349 } 350 351 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, 352 short generation) 353 { 354 struct stripe_head *sh; 355 struct hlist_node *hn; 356 357 CHECK_DEVLOCK(); 358 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); 359 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash) 360 if (sh->sector == sector && sh->generation == generation) 361 return sh; 362 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); 363 return NULL; 364 } 365 366 /* 367 * Need to check if array has failed when deciding whether to: 368 * - start an array 369 * - remove non-faulty devices 370 * - add a spare 371 * - allow a reshape 372 * This determination is simple when no reshape is happening. 373 * However if there is a reshape, we need to carefully check 374 * both the before and after sections. 375 * This is because some failed devices may only affect one 376 * of the two sections, and some non-in_sync devices may 377 * be insync in the section most affected by failed devices. 378 */ 379 static int has_failed(raid5_conf_t *conf) 380 { 381 int degraded; 382 int i; 383 if (conf->mddev->reshape_position == MaxSector) 384 return conf->mddev->degraded > conf->max_degraded; 385 386 rcu_read_lock(); 387 degraded = 0; 388 for (i = 0; i < conf->previous_raid_disks; i++) { 389 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 390 if (!rdev || test_bit(Faulty, &rdev->flags)) 391 degraded++; 392 else if (test_bit(In_sync, &rdev->flags)) 393 ; 394 else 395 /* not in-sync or faulty. 396 * If the reshape increases the number of devices, 397 * this is being recovered by the reshape, so 398 * this 'previous' section is not in_sync. 399 * If the number of devices is being reduced however, 400 * the device can only be part of the array if 401 * we are reverting a reshape, so this section will 402 * be in-sync. 403 */ 404 if (conf->raid_disks >= conf->previous_raid_disks) 405 degraded++; 406 } 407 rcu_read_unlock(); 408 if (degraded > conf->max_degraded) 409 return 1; 410 rcu_read_lock(); 411 degraded = 0; 412 for (i = 0; i < conf->raid_disks; i++) { 413 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev); 414 if (!rdev || test_bit(Faulty, &rdev->flags)) 415 degraded++; 416 else if (test_bit(In_sync, &rdev->flags)) 417 ; 418 else 419 /* not in-sync or faulty. 420 * If reshape increases the number of devices, this 421 * section has already been recovered, else it 422 * almost certainly hasn't. 423 */ 424 if (conf->raid_disks <= conf->previous_raid_disks) 425 degraded++; 426 } 427 rcu_read_unlock(); 428 if (degraded > conf->max_degraded) 429 return 1; 430 return 0; 431 } 432 433 static struct stripe_head * 434 get_active_stripe(raid5_conf_t *conf, sector_t sector, 435 int previous, int noblock, int noquiesce) 436 { 437 struct stripe_head *sh; 438 439 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); 440 441 spin_lock_irq(&conf->device_lock); 442 443 do { 444 wait_event_lock_irq(conf->wait_for_stripe, 445 conf->quiesce == 0 || noquiesce, 446 conf->device_lock, /* nothing */); 447 sh = __find_stripe(conf, sector, conf->generation - previous); 448 if (!sh) { 449 if (!conf->inactive_blocked) 450 sh = get_free_stripe(conf); 451 if (noblock && sh == NULL) 452 break; 453 if (!sh) { 454 conf->inactive_blocked = 1; 455 wait_event_lock_irq(conf->wait_for_stripe, 456 !list_empty(&conf->inactive_list) && 457 (atomic_read(&conf->active_stripes) 458 < (conf->max_nr_stripes *3/4) 459 || !conf->inactive_blocked), 460 conf->device_lock, 461 ); 462 conf->inactive_blocked = 0; 463 } else 464 init_stripe(sh, sector, previous); 465 } else { 466 if (atomic_read(&sh->count)) { 467 BUG_ON(!list_empty(&sh->lru) 468 && !test_bit(STRIPE_EXPANDING, &sh->state)); 469 } else { 470 if (!test_bit(STRIPE_HANDLE, &sh->state)) 471 atomic_inc(&conf->active_stripes); 472 if (list_empty(&sh->lru) && 473 !test_bit(STRIPE_EXPANDING, &sh->state)) 474 BUG(); 475 list_del_init(&sh->lru); 476 } 477 } 478 } while (sh == NULL); 479 480 if (sh) 481 atomic_inc(&sh->count); 482 483 spin_unlock_irq(&conf->device_lock); 484 return sh; 485 } 486 487 static void 488 raid5_end_read_request(struct bio *bi, int error); 489 static void 490 raid5_end_write_request(struct bio *bi, int error); 491 492 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 493 { 494 raid5_conf_t *conf = sh->raid_conf; 495 int i, disks = sh->disks; 496 497 might_sleep(); 498 499 for (i = disks; i--; ) { 500 int rw; 501 struct bio *bi; 502 mdk_rdev_t *rdev; 503 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { 504 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) 505 rw = WRITE_FUA; 506 else 507 rw = WRITE; 508 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) 509 rw = READ; 510 else 511 continue; 512 513 bi = &sh->dev[i].req; 514 515 bi->bi_rw = rw; 516 if (rw & WRITE) 517 bi->bi_end_io = raid5_end_write_request; 518 else 519 bi->bi_end_io = raid5_end_read_request; 520 521 rcu_read_lock(); 522 rdev = rcu_dereference(conf->disks[i].rdev); 523 if (rdev && test_bit(Faulty, &rdev->flags)) 524 rdev = NULL; 525 if (rdev) 526 atomic_inc(&rdev->nr_pending); 527 rcu_read_unlock(); 528 529 /* We have already checked bad blocks for reads. Now 530 * need to check for writes. 531 */ 532 while ((rw & WRITE) && rdev && 533 test_bit(WriteErrorSeen, &rdev->flags)) { 534 sector_t first_bad; 535 int bad_sectors; 536 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 537 &first_bad, &bad_sectors); 538 if (!bad) 539 break; 540 541 if (bad < 0) { 542 set_bit(BlockedBadBlocks, &rdev->flags); 543 if (!conf->mddev->external && 544 conf->mddev->flags) { 545 /* It is very unlikely, but we might 546 * still need to write out the 547 * bad block log - better give it 548 * a chance*/ 549 md_check_recovery(conf->mddev); 550 } 551 md_wait_for_blocked_rdev(rdev, conf->mddev); 552 } else { 553 /* Acknowledged bad block - skip the write */ 554 rdev_dec_pending(rdev, conf->mddev); 555 rdev = NULL; 556 } 557 } 558 559 if (rdev) { 560 if (s->syncing || s->expanding || s->expanded) 561 md_sync_acct(rdev->bdev, STRIPE_SECTORS); 562 563 set_bit(STRIPE_IO_STARTED, &sh->state); 564 565 bi->bi_bdev = rdev->bdev; 566 pr_debug("%s: for %llu schedule op %ld on disc %d\n", 567 __func__, (unsigned long long)sh->sector, 568 bi->bi_rw, i); 569 atomic_inc(&sh->count); 570 bi->bi_sector = sh->sector + rdev->data_offset; 571 bi->bi_flags = 1 << BIO_UPTODATE; 572 bi->bi_vcnt = 1; 573 bi->bi_max_vecs = 1; 574 bi->bi_idx = 0; 575 bi->bi_io_vec = &sh->dev[i].vec; 576 bi->bi_io_vec[0].bv_len = STRIPE_SIZE; 577 bi->bi_io_vec[0].bv_offset = 0; 578 bi->bi_size = STRIPE_SIZE; 579 bi->bi_next = NULL; 580 generic_make_request(bi); 581 } else { 582 if (rw & WRITE) 583 set_bit(STRIPE_DEGRADED, &sh->state); 584 pr_debug("skip op %ld on disc %d for sector %llu\n", 585 bi->bi_rw, i, (unsigned long long)sh->sector); 586 clear_bit(R5_LOCKED, &sh->dev[i].flags); 587 set_bit(STRIPE_HANDLE, &sh->state); 588 } 589 } 590 } 591 592 static struct dma_async_tx_descriptor * 593 async_copy_data(int frombio, struct bio *bio, struct page *page, 594 sector_t sector, struct dma_async_tx_descriptor *tx) 595 { 596 struct bio_vec *bvl; 597 struct page *bio_page; 598 int i; 599 int page_offset; 600 struct async_submit_ctl submit; 601 enum async_tx_flags flags = 0; 602 603 if (bio->bi_sector >= sector) 604 page_offset = (signed)(bio->bi_sector - sector) * 512; 605 else 606 page_offset = (signed)(sector - bio->bi_sector) * -512; 607 608 if (frombio) 609 flags |= ASYNC_TX_FENCE; 610 init_async_submit(&submit, flags, tx, NULL, NULL, NULL); 611 612 bio_for_each_segment(bvl, bio, i) { 613 int len = bvl->bv_len; 614 int clen; 615 int b_offset = 0; 616 617 if (page_offset < 0) { 618 b_offset = -page_offset; 619 page_offset += b_offset; 620 len -= b_offset; 621 } 622 623 if (len > 0 && page_offset + len > STRIPE_SIZE) 624 clen = STRIPE_SIZE - page_offset; 625 else 626 clen = len; 627 628 if (clen > 0) { 629 b_offset += bvl->bv_offset; 630 bio_page = bvl->bv_page; 631 if (frombio) 632 tx = async_memcpy(page, bio_page, page_offset, 633 b_offset, clen, &submit); 634 else 635 tx = async_memcpy(bio_page, page, b_offset, 636 page_offset, clen, &submit); 637 } 638 /* chain the operations */ 639 submit.depend_tx = tx; 640 641 if (clen < len) /* hit end of page */ 642 break; 643 page_offset += len; 644 } 645 646 return tx; 647 } 648 649 static void ops_complete_biofill(void *stripe_head_ref) 650 { 651 struct stripe_head *sh = stripe_head_ref; 652 struct bio *return_bi = NULL; 653 raid5_conf_t *conf = sh->raid_conf; 654 int i; 655 656 pr_debug("%s: stripe %llu\n", __func__, 657 (unsigned long long)sh->sector); 658 659 /* clear completed biofills */ 660 spin_lock_irq(&conf->device_lock); 661 for (i = sh->disks; i--; ) { 662 struct r5dev *dev = &sh->dev[i]; 663 664 /* acknowledge completion of a biofill operation */ 665 /* and check if we need to reply to a read request, 666 * new R5_Wantfill requests are held off until 667 * !STRIPE_BIOFILL_RUN 668 */ 669 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) { 670 struct bio *rbi, *rbi2; 671 672 BUG_ON(!dev->read); 673 rbi = dev->read; 674 dev->read = NULL; 675 while (rbi && rbi->bi_sector < 676 dev->sector + STRIPE_SECTORS) { 677 rbi2 = r5_next_bio(rbi, dev->sector); 678 if (!raid5_dec_bi_phys_segments(rbi)) { 679 rbi->bi_next = return_bi; 680 return_bi = rbi; 681 } 682 rbi = rbi2; 683 } 684 } 685 } 686 spin_unlock_irq(&conf->device_lock); 687 clear_bit(STRIPE_BIOFILL_RUN, &sh->state); 688 689 return_io(return_bi); 690 691 set_bit(STRIPE_HANDLE, &sh->state); 692 release_stripe(sh); 693 } 694 695 static void ops_run_biofill(struct stripe_head *sh) 696 { 697 struct dma_async_tx_descriptor *tx = NULL; 698 raid5_conf_t *conf = sh->raid_conf; 699 struct async_submit_ctl submit; 700 int i; 701 702 pr_debug("%s: stripe %llu\n", __func__, 703 (unsigned long long)sh->sector); 704 705 for (i = sh->disks; i--; ) { 706 struct r5dev *dev = &sh->dev[i]; 707 if (test_bit(R5_Wantfill, &dev->flags)) { 708 struct bio *rbi; 709 spin_lock_irq(&conf->device_lock); 710 dev->read = rbi = dev->toread; 711 dev->toread = NULL; 712 spin_unlock_irq(&conf->device_lock); 713 while (rbi && rbi->bi_sector < 714 dev->sector + STRIPE_SECTORS) { 715 tx = async_copy_data(0, rbi, dev->page, 716 dev->sector, tx); 717 rbi = r5_next_bio(rbi, dev->sector); 718 } 719 } 720 } 721 722 atomic_inc(&sh->count); 723 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); 724 async_trigger_callback(&submit); 725 } 726 727 static void mark_target_uptodate(struct stripe_head *sh, int target) 728 { 729 struct r5dev *tgt; 730 731 if (target < 0) 732 return; 733 734 tgt = &sh->dev[target]; 735 set_bit(R5_UPTODATE, &tgt->flags); 736 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 737 clear_bit(R5_Wantcompute, &tgt->flags); 738 } 739 740 static void ops_complete_compute(void *stripe_head_ref) 741 { 742 struct stripe_head *sh = stripe_head_ref; 743 744 pr_debug("%s: stripe %llu\n", __func__, 745 (unsigned long long)sh->sector); 746 747 /* mark the computed target(s) as uptodate */ 748 mark_target_uptodate(sh, sh->ops.target); 749 mark_target_uptodate(sh, sh->ops.target2); 750 751 clear_bit(STRIPE_COMPUTE_RUN, &sh->state); 752 if (sh->check_state == check_state_compute_run) 753 sh->check_state = check_state_compute_result; 754 set_bit(STRIPE_HANDLE, &sh->state); 755 release_stripe(sh); 756 } 757 758 /* return a pointer to the address conversion region of the scribble buffer */ 759 static addr_conv_t *to_addr_conv(struct stripe_head *sh, 760 struct raid5_percpu *percpu) 761 { 762 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2); 763 } 764 765 static struct dma_async_tx_descriptor * 766 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 767 { 768 int disks = sh->disks; 769 struct page **xor_srcs = percpu->scribble; 770 int target = sh->ops.target; 771 struct r5dev *tgt = &sh->dev[target]; 772 struct page *xor_dest = tgt->page; 773 int count = 0; 774 struct dma_async_tx_descriptor *tx; 775 struct async_submit_ctl submit; 776 int i; 777 778 pr_debug("%s: stripe %llu block: %d\n", 779 __func__, (unsigned long long)sh->sector, target); 780 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 781 782 for (i = disks; i--; ) 783 if (i != target) 784 xor_srcs[count++] = sh->dev[i].page; 785 786 atomic_inc(&sh->count); 787 788 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, 789 ops_complete_compute, sh, to_addr_conv(sh, percpu)); 790 if (unlikely(count == 1)) 791 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 792 else 793 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 794 795 return tx; 796 } 797 798 /* set_syndrome_sources - populate source buffers for gen_syndrome 799 * @srcs - (struct page *) array of size sh->disks 800 * @sh - stripe_head to parse 801 * 802 * Populates srcs in proper layout order for the stripe and returns the 803 * 'count' of sources to be used in a call to async_gen_syndrome. The P 804 * destination buffer is recorded in srcs[count] and the Q destination 805 * is recorded in srcs[count+1]]. 806 */ 807 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) 808 { 809 int disks = sh->disks; 810 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2); 811 int d0_idx = raid6_d0(sh); 812 int count; 813 int i; 814 815 for (i = 0; i < disks; i++) 816 srcs[i] = NULL; 817 818 count = 0; 819 i = d0_idx; 820 do { 821 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 822 823 srcs[slot] = sh->dev[i].page; 824 i = raid6_next_disk(i, disks); 825 } while (i != d0_idx); 826 827 return syndrome_disks; 828 } 829 830 static struct dma_async_tx_descriptor * 831 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) 832 { 833 int disks = sh->disks; 834 struct page **blocks = percpu->scribble; 835 int target; 836 int qd_idx = sh->qd_idx; 837 struct dma_async_tx_descriptor *tx; 838 struct async_submit_ctl submit; 839 struct r5dev *tgt; 840 struct page *dest; 841 int i; 842 int count; 843 844 if (sh->ops.target < 0) 845 target = sh->ops.target2; 846 else if (sh->ops.target2 < 0) 847 target = sh->ops.target; 848 else 849 /* we should only have one valid target */ 850 BUG(); 851 BUG_ON(target < 0); 852 pr_debug("%s: stripe %llu block: %d\n", 853 __func__, (unsigned long long)sh->sector, target); 854 855 tgt = &sh->dev[target]; 856 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 857 dest = tgt->page; 858 859 atomic_inc(&sh->count); 860 861 if (target == qd_idx) { 862 count = set_syndrome_sources(blocks, sh); 863 blocks[count] = NULL; /* regenerating p is not necessary */ 864 BUG_ON(blocks[count+1] != dest); /* q should already be set */ 865 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 866 ops_complete_compute, sh, 867 to_addr_conv(sh, percpu)); 868 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 869 } else { 870 /* Compute any data- or p-drive using XOR */ 871 count = 0; 872 for (i = disks; i-- ; ) { 873 if (i == target || i == qd_idx) 874 continue; 875 blocks[count++] = sh->dev[i].page; 876 } 877 878 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 879 NULL, ops_complete_compute, sh, 880 to_addr_conv(sh, percpu)); 881 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit); 882 } 883 884 return tx; 885 } 886 887 static struct dma_async_tx_descriptor * 888 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) 889 { 890 int i, count, disks = sh->disks; 891 int syndrome_disks = sh->ddf_layout ? disks : disks-2; 892 int d0_idx = raid6_d0(sh); 893 int faila = -1, failb = -1; 894 int target = sh->ops.target; 895 int target2 = sh->ops.target2; 896 struct r5dev *tgt = &sh->dev[target]; 897 struct r5dev *tgt2 = &sh->dev[target2]; 898 struct dma_async_tx_descriptor *tx; 899 struct page **blocks = percpu->scribble; 900 struct async_submit_ctl submit; 901 902 pr_debug("%s: stripe %llu block1: %d block2: %d\n", 903 __func__, (unsigned long long)sh->sector, target, target2); 904 BUG_ON(target < 0 || target2 < 0); 905 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); 906 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags)); 907 908 /* we need to open-code set_syndrome_sources to handle the 909 * slot number conversion for 'faila' and 'failb' 910 */ 911 for (i = 0; i < disks ; i++) 912 blocks[i] = NULL; 913 count = 0; 914 i = d0_idx; 915 do { 916 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks); 917 918 blocks[slot] = sh->dev[i].page; 919 920 if (i == target) 921 faila = slot; 922 if (i == target2) 923 failb = slot; 924 i = raid6_next_disk(i, disks); 925 } while (i != d0_idx); 926 927 BUG_ON(faila == failb); 928 if (failb < faila) 929 swap(faila, failb); 930 pr_debug("%s: stripe: %llu faila: %d failb: %d\n", 931 __func__, (unsigned long long)sh->sector, faila, failb); 932 933 atomic_inc(&sh->count); 934 935 if (failb == syndrome_disks+1) { 936 /* Q disk is one of the missing disks */ 937 if (faila == syndrome_disks) { 938 /* Missing P+Q, just recompute */ 939 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 940 ops_complete_compute, sh, 941 to_addr_conv(sh, percpu)); 942 return async_gen_syndrome(blocks, 0, syndrome_disks+2, 943 STRIPE_SIZE, &submit); 944 } else { 945 struct page *dest; 946 int data_target; 947 int qd_idx = sh->qd_idx; 948 949 /* Missing D+Q: recompute D from P, then recompute Q */ 950 if (target == qd_idx) 951 data_target = target2; 952 else 953 data_target = target; 954 955 count = 0; 956 for (i = disks; i-- ; ) { 957 if (i == data_target || i == qd_idx) 958 continue; 959 blocks[count++] = sh->dev[i].page; 960 } 961 dest = sh->dev[data_target].page; 962 init_async_submit(&submit, 963 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, 964 NULL, NULL, NULL, 965 to_addr_conv(sh, percpu)); 966 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, 967 &submit); 968 969 count = set_syndrome_sources(blocks, sh); 970 init_async_submit(&submit, ASYNC_TX_FENCE, tx, 971 ops_complete_compute, sh, 972 to_addr_conv(sh, percpu)); 973 return async_gen_syndrome(blocks, 0, count+2, 974 STRIPE_SIZE, &submit); 975 } 976 } else { 977 init_async_submit(&submit, ASYNC_TX_FENCE, NULL, 978 ops_complete_compute, sh, 979 to_addr_conv(sh, percpu)); 980 if (failb == syndrome_disks) { 981 /* We're missing D+P. */ 982 return async_raid6_datap_recov(syndrome_disks+2, 983 STRIPE_SIZE, faila, 984 blocks, &submit); 985 } else { 986 /* We're missing D+D. */ 987 return async_raid6_2data_recov(syndrome_disks+2, 988 STRIPE_SIZE, faila, failb, 989 blocks, &submit); 990 } 991 } 992 } 993 994 995 static void ops_complete_prexor(void *stripe_head_ref) 996 { 997 struct stripe_head *sh = stripe_head_ref; 998 999 pr_debug("%s: stripe %llu\n", __func__, 1000 (unsigned long long)sh->sector); 1001 } 1002 1003 static struct dma_async_tx_descriptor * 1004 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu, 1005 struct dma_async_tx_descriptor *tx) 1006 { 1007 int disks = sh->disks; 1008 struct page **xor_srcs = percpu->scribble; 1009 int count = 0, pd_idx = sh->pd_idx, i; 1010 struct async_submit_ctl submit; 1011 1012 /* existing parity data subtracted */ 1013 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1014 1015 pr_debug("%s: stripe %llu\n", __func__, 1016 (unsigned long long)sh->sector); 1017 1018 for (i = disks; i--; ) { 1019 struct r5dev *dev = &sh->dev[i]; 1020 /* Only process blocks that are known to be uptodate */ 1021 if (test_bit(R5_Wantdrain, &dev->flags)) 1022 xor_srcs[count++] = dev->page; 1023 } 1024 1025 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, 1026 ops_complete_prexor, sh, to_addr_conv(sh, percpu)); 1027 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1028 1029 return tx; 1030 } 1031 1032 static struct dma_async_tx_descriptor * 1033 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 1034 { 1035 int disks = sh->disks; 1036 int i; 1037 1038 pr_debug("%s: stripe %llu\n", __func__, 1039 (unsigned long long)sh->sector); 1040 1041 for (i = disks; i--; ) { 1042 struct r5dev *dev = &sh->dev[i]; 1043 struct bio *chosen; 1044 1045 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) { 1046 struct bio *wbi; 1047 1048 spin_lock_irq(&sh->raid_conf->device_lock); 1049 chosen = dev->towrite; 1050 dev->towrite = NULL; 1051 BUG_ON(dev->written); 1052 wbi = dev->written = chosen; 1053 spin_unlock_irq(&sh->raid_conf->device_lock); 1054 1055 while (wbi && wbi->bi_sector < 1056 dev->sector + STRIPE_SECTORS) { 1057 if (wbi->bi_rw & REQ_FUA) 1058 set_bit(R5_WantFUA, &dev->flags); 1059 tx = async_copy_data(1, wbi, dev->page, 1060 dev->sector, tx); 1061 wbi = r5_next_bio(wbi, dev->sector); 1062 } 1063 } 1064 } 1065 1066 return tx; 1067 } 1068 1069 static void ops_complete_reconstruct(void *stripe_head_ref) 1070 { 1071 struct stripe_head *sh = stripe_head_ref; 1072 int disks = sh->disks; 1073 int pd_idx = sh->pd_idx; 1074 int qd_idx = sh->qd_idx; 1075 int i; 1076 bool fua = false; 1077 1078 pr_debug("%s: stripe %llu\n", __func__, 1079 (unsigned long long)sh->sector); 1080 1081 for (i = disks; i--; ) 1082 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); 1083 1084 for (i = disks; i--; ) { 1085 struct r5dev *dev = &sh->dev[i]; 1086 1087 if (dev->written || i == pd_idx || i == qd_idx) { 1088 set_bit(R5_UPTODATE, &dev->flags); 1089 if (fua) 1090 set_bit(R5_WantFUA, &dev->flags); 1091 } 1092 } 1093 1094 if (sh->reconstruct_state == reconstruct_state_drain_run) 1095 sh->reconstruct_state = reconstruct_state_drain_result; 1096 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) 1097 sh->reconstruct_state = reconstruct_state_prexor_drain_result; 1098 else { 1099 BUG_ON(sh->reconstruct_state != reconstruct_state_run); 1100 sh->reconstruct_state = reconstruct_state_result; 1101 } 1102 1103 set_bit(STRIPE_HANDLE, &sh->state); 1104 release_stripe(sh); 1105 } 1106 1107 static void 1108 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 1109 struct dma_async_tx_descriptor *tx) 1110 { 1111 int disks = sh->disks; 1112 struct page **xor_srcs = percpu->scribble; 1113 struct async_submit_ctl submit; 1114 int count = 0, pd_idx = sh->pd_idx, i; 1115 struct page *xor_dest; 1116 int prexor = 0; 1117 unsigned long flags; 1118 1119 pr_debug("%s: stripe %llu\n", __func__, 1120 (unsigned long long)sh->sector); 1121 1122 /* check if prexor is active which means only process blocks 1123 * that are part of a read-modify-write (written) 1124 */ 1125 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) { 1126 prexor = 1; 1127 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page; 1128 for (i = disks; i--; ) { 1129 struct r5dev *dev = &sh->dev[i]; 1130 if (dev->written) 1131 xor_srcs[count++] = dev->page; 1132 } 1133 } else { 1134 xor_dest = sh->dev[pd_idx].page; 1135 for (i = disks; i--; ) { 1136 struct r5dev *dev = &sh->dev[i]; 1137 if (i != pd_idx) 1138 xor_srcs[count++] = dev->page; 1139 } 1140 } 1141 1142 /* 1/ if we prexor'd then the dest is reused as a source 1143 * 2/ if we did not prexor then we are redoing the parity 1144 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST 1145 * for the synchronous xor case 1146 */ 1147 flags = ASYNC_TX_ACK | 1148 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); 1149 1150 atomic_inc(&sh->count); 1151 1152 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, 1153 to_addr_conv(sh, percpu)); 1154 if (unlikely(count == 1)) 1155 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); 1156 else 1157 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); 1158 } 1159 1160 static void 1161 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, 1162 struct dma_async_tx_descriptor *tx) 1163 { 1164 struct async_submit_ctl submit; 1165 struct page **blocks = percpu->scribble; 1166 int count; 1167 1168 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); 1169 1170 count = set_syndrome_sources(blocks, sh); 1171 1172 atomic_inc(&sh->count); 1173 1174 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct, 1175 sh, to_addr_conv(sh, percpu)); 1176 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit); 1177 } 1178 1179 static void ops_complete_check(void *stripe_head_ref) 1180 { 1181 struct stripe_head *sh = stripe_head_ref; 1182 1183 pr_debug("%s: stripe %llu\n", __func__, 1184 (unsigned long long)sh->sector); 1185 1186 sh->check_state = check_state_check_result; 1187 set_bit(STRIPE_HANDLE, &sh->state); 1188 release_stripe(sh); 1189 } 1190 1191 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) 1192 { 1193 int disks = sh->disks; 1194 int pd_idx = sh->pd_idx; 1195 int qd_idx = sh->qd_idx; 1196 struct page *xor_dest; 1197 struct page **xor_srcs = percpu->scribble; 1198 struct dma_async_tx_descriptor *tx; 1199 struct async_submit_ctl submit; 1200 int count; 1201 int i; 1202 1203 pr_debug("%s: stripe %llu\n", __func__, 1204 (unsigned long long)sh->sector); 1205 1206 count = 0; 1207 xor_dest = sh->dev[pd_idx].page; 1208 xor_srcs[count++] = xor_dest; 1209 for (i = disks; i--; ) { 1210 if (i == pd_idx || i == qd_idx) 1211 continue; 1212 xor_srcs[count++] = sh->dev[i].page; 1213 } 1214 1215 init_async_submit(&submit, 0, NULL, NULL, NULL, 1216 to_addr_conv(sh, percpu)); 1217 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, 1218 &sh->ops.zero_sum_result, &submit); 1219 1220 atomic_inc(&sh->count); 1221 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); 1222 tx = async_trigger_callback(&submit); 1223 } 1224 1225 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp) 1226 { 1227 struct page **srcs = percpu->scribble; 1228 struct async_submit_ctl submit; 1229 int count; 1230 1231 pr_debug("%s: stripe %llu checkp: %d\n", __func__, 1232 (unsigned long long)sh->sector, checkp); 1233 1234 count = set_syndrome_sources(srcs, sh); 1235 if (!checkp) 1236 srcs[count] = NULL; 1237 1238 atomic_inc(&sh->count); 1239 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, 1240 sh, to_addr_conv(sh, percpu)); 1241 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, 1242 &sh->ops.zero_sum_result, percpu->spare_page, &submit); 1243 } 1244 1245 static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1246 { 1247 int overlap_clear = 0, i, disks = sh->disks; 1248 struct dma_async_tx_descriptor *tx = NULL; 1249 raid5_conf_t *conf = sh->raid_conf; 1250 int level = conf->level; 1251 struct raid5_percpu *percpu; 1252 unsigned long cpu; 1253 1254 cpu = get_cpu(); 1255 percpu = per_cpu_ptr(conf->percpu, cpu); 1256 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { 1257 ops_run_biofill(sh); 1258 overlap_clear++; 1259 } 1260 1261 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) { 1262 if (level < 6) 1263 tx = ops_run_compute5(sh, percpu); 1264 else { 1265 if (sh->ops.target2 < 0 || sh->ops.target < 0) 1266 tx = ops_run_compute6_1(sh, percpu); 1267 else 1268 tx = ops_run_compute6_2(sh, percpu); 1269 } 1270 /* terminate the chain if reconstruct is not set to be run */ 1271 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) 1272 async_tx_ack(tx); 1273 } 1274 1275 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) 1276 tx = ops_run_prexor(sh, percpu, tx); 1277 1278 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { 1279 tx = ops_run_biodrain(sh, tx); 1280 overlap_clear++; 1281 } 1282 1283 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { 1284 if (level < 6) 1285 ops_run_reconstruct5(sh, percpu, tx); 1286 else 1287 ops_run_reconstruct6(sh, percpu, tx); 1288 } 1289 1290 if (test_bit(STRIPE_OP_CHECK, &ops_request)) { 1291 if (sh->check_state == check_state_run) 1292 ops_run_check_p(sh, percpu); 1293 else if (sh->check_state == check_state_run_q) 1294 ops_run_check_pq(sh, percpu, 0); 1295 else if (sh->check_state == check_state_run_pq) 1296 ops_run_check_pq(sh, percpu, 1); 1297 else 1298 BUG(); 1299 } 1300 1301 if (overlap_clear) 1302 for (i = disks; i--; ) { 1303 struct r5dev *dev = &sh->dev[i]; 1304 if (test_and_clear_bit(R5_Overlap, &dev->flags)) 1305 wake_up(&sh->raid_conf->wait_for_overlap); 1306 } 1307 put_cpu(); 1308 } 1309 1310 #ifdef CONFIG_MULTICORE_RAID456 1311 static void async_run_ops(void *param, async_cookie_t cookie) 1312 { 1313 struct stripe_head *sh = param; 1314 unsigned long ops_request = sh->ops.request; 1315 1316 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state); 1317 wake_up(&sh->ops.wait_for_ops); 1318 1319 __raid_run_ops(sh, ops_request); 1320 release_stripe(sh); 1321 } 1322 1323 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 1324 { 1325 /* since handle_stripe can be called outside of raid5d context 1326 * we need to ensure sh->ops.request is de-staged before another 1327 * request arrives 1328 */ 1329 wait_event(sh->ops.wait_for_ops, 1330 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state)); 1331 sh->ops.request = ops_request; 1332 1333 atomic_inc(&sh->count); 1334 async_schedule(async_run_ops, sh); 1335 } 1336 #else 1337 #define raid_run_ops __raid_run_ops 1338 #endif 1339 1340 static int grow_one_stripe(raid5_conf_t *conf) 1341 { 1342 struct stripe_head *sh; 1343 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL); 1344 if (!sh) 1345 return 0; 1346 1347 sh->raid_conf = conf; 1348 #ifdef CONFIG_MULTICORE_RAID456 1349 init_waitqueue_head(&sh->ops.wait_for_ops); 1350 #endif 1351 1352 if (grow_buffers(sh)) { 1353 shrink_buffers(sh); 1354 kmem_cache_free(conf->slab_cache, sh); 1355 return 0; 1356 } 1357 /* we just created an active stripe so... */ 1358 atomic_set(&sh->count, 1); 1359 atomic_inc(&conf->active_stripes); 1360 INIT_LIST_HEAD(&sh->lru); 1361 release_stripe(sh); 1362 return 1; 1363 } 1364 1365 static int grow_stripes(raid5_conf_t *conf, int num) 1366 { 1367 struct kmem_cache *sc; 1368 int devs = max(conf->raid_disks, conf->previous_raid_disks); 1369 1370 if (conf->mddev->gendisk) 1371 sprintf(conf->cache_name[0], 1372 "raid%d-%s", conf->level, mdname(conf->mddev)); 1373 else 1374 sprintf(conf->cache_name[0], 1375 "raid%d-%p", conf->level, conf->mddev); 1376 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]); 1377 1378 conf->active_name = 0; 1379 sc = kmem_cache_create(conf->cache_name[conf->active_name], 1380 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), 1381 0, 0, NULL); 1382 if (!sc) 1383 return 1; 1384 conf->slab_cache = sc; 1385 conf->pool_size = devs; 1386 while (num--) 1387 if (!grow_one_stripe(conf)) 1388 return 1; 1389 return 0; 1390 } 1391 1392 /** 1393 * scribble_len - return the required size of the scribble region 1394 * @num - total number of disks in the array 1395 * 1396 * The size must be enough to contain: 1397 * 1/ a struct page pointer for each device in the array +2 1398 * 2/ room to convert each entry in (1) to its corresponding dma 1399 * (dma_map_page()) or page (page_address()) address. 1400 * 1401 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we 1402 * calculate over all devices (not just the data blocks), using zeros in place 1403 * of the P and Q blocks. 1404 */ 1405 static size_t scribble_len(int num) 1406 { 1407 size_t len; 1408 1409 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2); 1410 1411 return len; 1412 } 1413 1414 static int resize_stripes(raid5_conf_t *conf, int newsize) 1415 { 1416 /* Make all the stripes able to hold 'newsize' devices. 1417 * New slots in each stripe get 'page' set to a new page. 1418 * 1419 * This happens in stages: 1420 * 1/ create a new kmem_cache and allocate the required number of 1421 * stripe_heads. 1422 * 2/ gather all the old stripe_heads and tranfer the pages across 1423 * to the new stripe_heads. This will have the side effect of 1424 * freezing the array as once all stripe_heads have been collected, 1425 * no IO will be possible. Old stripe heads are freed once their 1426 * pages have been transferred over, and the old kmem_cache is 1427 * freed when all stripes are done. 1428 * 3/ reallocate conf->disks to be suitable bigger. If this fails, 1429 * we simple return a failre status - no need to clean anything up. 1430 * 4/ allocate new pages for the new slots in the new stripe_heads. 1431 * If this fails, we don't bother trying the shrink the 1432 * stripe_heads down again, we just leave them as they are. 1433 * As each stripe_head is processed the new one is released into 1434 * active service. 1435 * 1436 * Once step2 is started, we cannot afford to wait for a write, 1437 * so we use GFP_NOIO allocations. 1438 */ 1439 struct stripe_head *osh, *nsh; 1440 LIST_HEAD(newstripes); 1441 struct disk_info *ndisks; 1442 unsigned long cpu; 1443 int err; 1444 struct kmem_cache *sc; 1445 int i; 1446 1447 if (newsize <= conf->pool_size) 1448 return 0; /* never bother to shrink */ 1449 1450 err = md_allow_write(conf->mddev); 1451 if (err) 1452 return err; 1453 1454 /* Step 1 */ 1455 sc = kmem_cache_create(conf->cache_name[1-conf->active_name], 1456 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev), 1457 0, 0, NULL); 1458 if (!sc) 1459 return -ENOMEM; 1460 1461 for (i = conf->max_nr_stripes; i; i--) { 1462 nsh = kmem_cache_zalloc(sc, GFP_KERNEL); 1463 if (!nsh) 1464 break; 1465 1466 nsh->raid_conf = conf; 1467 #ifdef CONFIG_MULTICORE_RAID456 1468 init_waitqueue_head(&nsh->ops.wait_for_ops); 1469 #endif 1470 1471 list_add(&nsh->lru, &newstripes); 1472 } 1473 if (i) { 1474 /* didn't get enough, give up */ 1475 while (!list_empty(&newstripes)) { 1476 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1477 list_del(&nsh->lru); 1478 kmem_cache_free(sc, nsh); 1479 } 1480 kmem_cache_destroy(sc); 1481 return -ENOMEM; 1482 } 1483 /* Step 2 - Must use GFP_NOIO now. 1484 * OK, we have enough stripes, start collecting inactive 1485 * stripes and copying them over 1486 */ 1487 list_for_each_entry(nsh, &newstripes, lru) { 1488 spin_lock_irq(&conf->device_lock); 1489 wait_event_lock_irq(conf->wait_for_stripe, 1490 !list_empty(&conf->inactive_list), 1491 conf->device_lock, 1492 ); 1493 osh = get_free_stripe(conf); 1494 spin_unlock_irq(&conf->device_lock); 1495 atomic_set(&nsh->count, 1); 1496 for(i=0; i<conf->pool_size; i++) 1497 nsh->dev[i].page = osh->dev[i].page; 1498 for( ; i<newsize; i++) 1499 nsh->dev[i].page = NULL; 1500 kmem_cache_free(conf->slab_cache, osh); 1501 } 1502 kmem_cache_destroy(conf->slab_cache); 1503 1504 /* Step 3. 1505 * At this point, we are holding all the stripes so the array 1506 * is completely stalled, so now is a good time to resize 1507 * conf->disks and the scribble region 1508 */ 1509 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO); 1510 if (ndisks) { 1511 for (i=0; i<conf->raid_disks; i++) 1512 ndisks[i] = conf->disks[i]; 1513 kfree(conf->disks); 1514 conf->disks = ndisks; 1515 } else 1516 err = -ENOMEM; 1517 1518 get_online_cpus(); 1519 conf->scribble_len = scribble_len(newsize); 1520 for_each_present_cpu(cpu) { 1521 struct raid5_percpu *percpu; 1522 void *scribble; 1523 1524 percpu = per_cpu_ptr(conf->percpu, cpu); 1525 scribble = kmalloc(conf->scribble_len, GFP_NOIO); 1526 1527 if (scribble) { 1528 kfree(percpu->scribble); 1529 percpu->scribble = scribble; 1530 } else { 1531 err = -ENOMEM; 1532 break; 1533 } 1534 } 1535 put_online_cpus(); 1536 1537 /* Step 4, return new stripes to service */ 1538 while(!list_empty(&newstripes)) { 1539 nsh = list_entry(newstripes.next, struct stripe_head, lru); 1540 list_del_init(&nsh->lru); 1541 1542 for (i=conf->raid_disks; i < newsize; i++) 1543 if (nsh->dev[i].page == NULL) { 1544 struct page *p = alloc_page(GFP_NOIO); 1545 nsh->dev[i].page = p; 1546 if (!p) 1547 err = -ENOMEM; 1548 } 1549 release_stripe(nsh); 1550 } 1551 /* critical section pass, GFP_NOIO no longer needed */ 1552 1553 conf->slab_cache = sc; 1554 conf->active_name = 1-conf->active_name; 1555 conf->pool_size = newsize; 1556 return err; 1557 } 1558 1559 static int drop_one_stripe(raid5_conf_t *conf) 1560 { 1561 struct stripe_head *sh; 1562 1563 spin_lock_irq(&conf->device_lock); 1564 sh = get_free_stripe(conf); 1565 spin_unlock_irq(&conf->device_lock); 1566 if (!sh) 1567 return 0; 1568 BUG_ON(atomic_read(&sh->count)); 1569 shrink_buffers(sh); 1570 kmem_cache_free(conf->slab_cache, sh); 1571 atomic_dec(&conf->active_stripes); 1572 return 1; 1573 } 1574 1575 static void shrink_stripes(raid5_conf_t *conf) 1576 { 1577 while (drop_one_stripe(conf)) 1578 ; 1579 1580 if (conf->slab_cache) 1581 kmem_cache_destroy(conf->slab_cache); 1582 conf->slab_cache = NULL; 1583 } 1584 1585 static void raid5_end_read_request(struct bio * bi, int error) 1586 { 1587 struct stripe_head *sh = bi->bi_private; 1588 raid5_conf_t *conf = sh->raid_conf; 1589 int disks = sh->disks, i; 1590 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1591 char b[BDEVNAME_SIZE]; 1592 mdk_rdev_t *rdev; 1593 1594 1595 for (i=0 ; i<disks; i++) 1596 if (bi == &sh->dev[i].req) 1597 break; 1598 1599 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", 1600 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1601 uptodate); 1602 if (i == disks) { 1603 BUG(); 1604 return; 1605 } 1606 1607 if (uptodate) { 1608 set_bit(R5_UPTODATE, &sh->dev[i].flags); 1609 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 1610 rdev = conf->disks[i].rdev; 1611 printk_ratelimited( 1612 KERN_INFO 1613 "md/raid:%s: read error corrected" 1614 " (%lu sectors at %llu on %s)\n", 1615 mdname(conf->mddev), STRIPE_SECTORS, 1616 (unsigned long long)(sh->sector 1617 + rdev->data_offset), 1618 bdevname(rdev->bdev, b)); 1619 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); 1620 clear_bit(R5_ReadError, &sh->dev[i].flags); 1621 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1622 } 1623 if (atomic_read(&conf->disks[i].rdev->read_errors)) 1624 atomic_set(&conf->disks[i].rdev->read_errors, 0); 1625 } else { 1626 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b); 1627 int retry = 0; 1628 rdev = conf->disks[i].rdev; 1629 1630 clear_bit(R5_UPTODATE, &sh->dev[i].flags); 1631 atomic_inc(&rdev->read_errors); 1632 if (conf->mddev->degraded >= conf->max_degraded) 1633 printk_ratelimited( 1634 KERN_WARNING 1635 "md/raid:%s: read error not correctable " 1636 "(sector %llu on %s).\n", 1637 mdname(conf->mddev), 1638 (unsigned long long)(sh->sector 1639 + rdev->data_offset), 1640 bdn); 1641 else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) 1642 /* Oh, no!!! */ 1643 printk_ratelimited( 1644 KERN_WARNING 1645 "md/raid:%s: read error NOT corrected!! " 1646 "(sector %llu on %s).\n", 1647 mdname(conf->mddev), 1648 (unsigned long long)(sh->sector 1649 + rdev->data_offset), 1650 bdn); 1651 else if (atomic_read(&rdev->read_errors) 1652 > conf->max_nr_stripes) 1653 printk(KERN_WARNING 1654 "md/raid:%s: Too many read errors, failing device %s.\n", 1655 mdname(conf->mddev), bdn); 1656 else 1657 retry = 1; 1658 if (retry) 1659 set_bit(R5_ReadError, &sh->dev[i].flags); 1660 else { 1661 clear_bit(R5_ReadError, &sh->dev[i].flags); 1662 clear_bit(R5_ReWrite, &sh->dev[i].flags); 1663 md_error(conf->mddev, rdev); 1664 } 1665 } 1666 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1667 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1668 set_bit(STRIPE_HANDLE, &sh->state); 1669 release_stripe(sh); 1670 } 1671 1672 static void raid5_end_write_request(struct bio *bi, int error) 1673 { 1674 struct stripe_head *sh = bi->bi_private; 1675 raid5_conf_t *conf = sh->raid_conf; 1676 int disks = sh->disks, i; 1677 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 1678 sector_t first_bad; 1679 int bad_sectors; 1680 1681 for (i=0 ; i<disks; i++) 1682 if (bi == &sh->dev[i].req) 1683 break; 1684 1685 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", 1686 (unsigned long long)sh->sector, i, atomic_read(&sh->count), 1687 uptodate); 1688 if (i == disks) { 1689 BUG(); 1690 return; 1691 } 1692 1693 if (!uptodate) { 1694 set_bit(WriteErrorSeen, &conf->disks[i].rdev->flags); 1695 set_bit(R5_WriteError, &sh->dev[i].flags); 1696 } else if (is_badblock(conf->disks[i].rdev, sh->sector, STRIPE_SECTORS, 1697 &first_bad, &bad_sectors)) 1698 set_bit(R5_MadeGood, &sh->dev[i].flags); 1699 1700 rdev_dec_pending(conf->disks[i].rdev, conf->mddev); 1701 1702 clear_bit(R5_LOCKED, &sh->dev[i].flags); 1703 set_bit(STRIPE_HANDLE, &sh->state); 1704 release_stripe(sh); 1705 } 1706 1707 1708 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous); 1709 1710 static void raid5_build_block(struct stripe_head *sh, int i, int previous) 1711 { 1712 struct r5dev *dev = &sh->dev[i]; 1713 1714 bio_init(&dev->req); 1715 dev->req.bi_io_vec = &dev->vec; 1716 dev->req.bi_vcnt++; 1717 dev->req.bi_max_vecs++; 1718 dev->vec.bv_page = dev->page; 1719 dev->vec.bv_len = STRIPE_SIZE; 1720 dev->vec.bv_offset = 0; 1721 1722 dev->req.bi_sector = sh->sector; 1723 dev->req.bi_private = sh; 1724 1725 dev->flags = 0; 1726 dev->sector = compute_blocknr(sh, i, previous); 1727 } 1728 1729 static void error(mddev_t *mddev, mdk_rdev_t *rdev) 1730 { 1731 char b[BDEVNAME_SIZE]; 1732 raid5_conf_t *conf = mddev->private; 1733 pr_debug("raid456: error called\n"); 1734 1735 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1736 unsigned long flags; 1737 spin_lock_irqsave(&conf->device_lock, flags); 1738 mddev->degraded++; 1739 spin_unlock_irqrestore(&conf->device_lock, flags); 1740 /* 1741 * if recovery was running, make sure it aborts. 1742 */ 1743 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1744 } 1745 set_bit(Blocked, &rdev->flags); 1746 set_bit(Faulty, &rdev->flags); 1747 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1748 printk(KERN_ALERT 1749 "md/raid:%s: Disk failure on %s, disabling device.\n" 1750 "md/raid:%s: Operation continuing on %d devices.\n", 1751 mdname(mddev), 1752 bdevname(rdev->bdev, b), 1753 mdname(mddev), 1754 conf->raid_disks - mddev->degraded); 1755 } 1756 1757 /* 1758 * Input: a 'big' sector number, 1759 * Output: index of the data and parity disk, and the sector # in them. 1760 */ 1761 static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, 1762 int previous, int *dd_idx, 1763 struct stripe_head *sh) 1764 { 1765 sector_t stripe, stripe2; 1766 sector_t chunk_number; 1767 unsigned int chunk_offset; 1768 int pd_idx, qd_idx; 1769 int ddf_layout = 0; 1770 sector_t new_sector; 1771 int algorithm = previous ? conf->prev_algo 1772 : conf->algorithm; 1773 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1774 : conf->chunk_sectors; 1775 int raid_disks = previous ? conf->previous_raid_disks 1776 : conf->raid_disks; 1777 int data_disks = raid_disks - conf->max_degraded; 1778 1779 /* First compute the information on this sector */ 1780 1781 /* 1782 * Compute the chunk number and the sector offset inside the chunk 1783 */ 1784 chunk_offset = sector_div(r_sector, sectors_per_chunk); 1785 chunk_number = r_sector; 1786 1787 /* 1788 * Compute the stripe number 1789 */ 1790 stripe = chunk_number; 1791 *dd_idx = sector_div(stripe, data_disks); 1792 stripe2 = stripe; 1793 /* 1794 * Select the parity disk based on the user selected algorithm. 1795 */ 1796 pd_idx = qd_idx = -1; 1797 switch(conf->level) { 1798 case 4: 1799 pd_idx = data_disks; 1800 break; 1801 case 5: 1802 switch (algorithm) { 1803 case ALGORITHM_LEFT_ASYMMETRIC: 1804 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1805 if (*dd_idx >= pd_idx) 1806 (*dd_idx)++; 1807 break; 1808 case ALGORITHM_RIGHT_ASYMMETRIC: 1809 pd_idx = sector_div(stripe2, raid_disks); 1810 if (*dd_idx >= pd_idx) 1811 (*dd_idx)++; 1812 break; 1813 case ALGORITHM_LEFT_SYMMETRIC: 1814 pd_idx = data_disks - sector_div(stripe2, raid_disks); 1815 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1816 break; 1817 case ALGORITHM_RIGHT_SYMMETRIC: 1818 pd_idx = sector_div(stripe2, raid_disks); 1819 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1820 break; 1821 case ALGORITHM_PARITY_0: 1822 pd_idx = 0; 1823 (*dd_idx)++; 1824 break; 1825 case ALGORITHM_PARITY_N: 1826 pd_idx = data_disks; 1827 break; 1828 default: 1829 BUG(); 1830 } 1831 break; 1832 case 6: 1833 1834 switch (algorithm) { 1835 case ALGORITHM_LEFT_ASYMMETRIC: 1836 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1837 qd_idx = pd_idx + 1; 1838 if (pd_idx == raid_disks-1) { 1839 (*dd_idx)++; /* Q D D D P */ 1840 qd_idx = 0; 1841 } else if (*dd_idx >= pd_idx) 1842 (*dd_idx) += 2; /* D D P Q D */ 1843 break; 1844 case ALGORITHM_RIGHT_ASYMMETRIC: 1845 pd_idx = sector_div(stripe2, raid_disks); 1846 qd_idx = pd_idx + 1; 1847 if (pd_idx == raid_disks-1) { 1848 (*dd_idx)++; /* Q D D D P */ 1849 qd_idx = 0; 1850 } else if (*dd_idx >= pd_idx) 1851 (*dd_idx) += 2; /* D D P Q D */ 1852 break; 1853 case ALGORITHM_LEFT_SYMMETRIC: 1854 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1855 qd_idx = (pd_idx + 1) % raid_disks; 1856 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1857 break; 1858 case ALGORITHM_RIGHT_SYMMETRIC: 1859 pd_idx = sector_div(stripe2, raid_disks); 1860 qd_idx = (pd_idx + 1) % raid_disks; 1861 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; 1862 break; 1863 1864 case ALGORITHM_PARITY_0: 1865 pd_idx = 0; 1866 qd_idx = 1; 1867 (*dd_idx) += 2; 1868 break; 1869 case ALGORITHM_PARITY_N: 1870 pd_idx = data_disks; 1871 qd_idx = data_disks + 1; 1872 break; 1873 1874 case ALGORITHM_ROTATING_ZERO_RESTART: 1875 /* Exactly the same as RIGHT_ASYMMETRIC, but or 1876 * of blocks for computing Q is different. 1877 */ 1878 pd_idx = sector_div(stripe2, raid_disks); 1879 qd_idx = pd_idx + 1; 1880 if (pd_idx == raid_disks-1) { 1881 (*dd_idx)++; /* Q D D D P */ 1882 qd_idx = 0; 1883 } else if (*dd_idx >= pd_idx) 1884 (*dd_idx) += 2; /* D D P Q D */ 1885 ddf_layout = 1; 1886 break; 1887 1888 case ALGORITHM_ROTATING_N_RESTART: 1889 /* Same a left_asymmetric, by first stripe is 1890 * D D D P Q rather than 1891 * Q D D D P 1892 */ 1893 stripe2 += 1; 1894 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1895 qd_idx = pd_idx + 1; 1896 if (pd_idx == raid_disks-1) { 1897 (*dd_idx)++; /* Q D D D P */ 1898 qd_idx = 0; 1899 } else if (*dd_idx >= pd_idx) 1900 (*dd_idx) += 2; /* D D P Q D */ 1901 ddf_layout = 1; 1902 break; 1903 1904 case ALGORITHM_ROTATING_N_CONTINUE: 1905 /* Same as left_symmetric but Q is before P */ 1906 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks); 1907 qd_idx = (pd_idx + raid_disks - 1) % raid_disks; 1908 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; 1909 ddf_layout = 1; 1910 break; 1911 1912 case ALGORITHM_LEFT_ASYMMETRIC_6: 1913 /* RAID5 left_asymmetric, with Q on last device */ 1914 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1915 if (*dd_idx >= pd_idx) 1916 (*dd_idx)++; 1917 qd_idx = raid_disks - 1; 1918 break; 1919 1920 case ALGORITHM_RIGHT_ASYMMETRIC_6: 1921 pd_idx = sector_div(stripe2, raid_disks-1); 1922 if (*dd_idx >= pd_idx) 1923 (*dd_idx)++; 1924 qd_idx = raid_disks - 1; 1925 break; 1926 1927 case ALGORITHM_LEFT_SYMMETRIC_6: 1928 pd_idx = data_disks - sector_div(stripe2, raid_disks-1); 1929 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1930 qd_idx = raid_disks - 1; 1931 break; 1932 1933 case ALGORITHM_RIGHT_SYMMETRIC_6: 1934 pd_idx = sector_div(stripe2, raid_disks-1); 1935 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); 1936 qd_idx = raid_disks - 1; 1937 break; 1938 1939 case ALGORITHM_PARITY_0_6: 1940 pd_idx = 0; 1941 (*dd_idx)++; 1942 qd_idx = raid_disks - 1; 1943 break; 1944 1945 default: 1946 BUG(); 1947 } 1948 break; 1949 } 1950 1951 if (sh) { 1952 sh->pd_idx = pd_idx; 1953 sh->qd_idx = qd_idx; 1954 sh->ddf_layout = ddf_layout; 1955 } 1956 /* 1957 * Finally, compute the new sector number 1958 */ 1959 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset; 1960 return new_sector; 1961 } 1962 1963 1964 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) 1965 { 1966 raid5_conf_t *conf = sh->raid_conf; 1967 int raid_disks = sh->disks; 1968 int data_disks = raid_disks - conf->max_degraded; 1969 sector_t new_sector = sh->sector, check; 1970 int sectors_per_chunk = previous ? conf->prev_chunk_sectors 1971 : conf->chunk_sectors; 1972 int algorithm = previous ? conf->prev_algo 1973 : conf->algorithm; 1974 sector_t stripe; 1975 int chunk_offset; 1976 sector_t chunk_number; 1977 int dummy1, dd_idx = i; 1978 sector_t r_sector; 1979 struct stripe_head sh2; 1980 1981 1982 chunk_offset = sector_div(new_sector, sectors_per_chunk); 1983 stripe = new_sector; 1984 1985 if (i == sh->pd_idx) 1986 return 0; 1987 switch(conf->level) { 1988 case 4: break; 1989 case 5: 1990 switch (algorithm) { 1991 case ALGORITHM_LEFT_ASYMMETRIC: 1992 case ALGORITHM_RIGHT_ASYMMETRIC: 1993 if (i > sh->pd_idx) 1994 i--; 1995 break; 1996 case ALGORITHM_LEFT_SYMMETRIC: 1997 case ALGORITHM_RIGHT_SYMMETRIC: 1998 if (i < sh->pd_idx) 1999 i += raid_disks; 2000 i -= (sh->pd_idx + 1); 2001 break; 2002 case ALGORITHM_PARITY_0: 2003 i -= 1; 2004 break; 2005 case ALGORITHM_PARITY_N: 2006 break; 2007 default: 2008 BUG(); 2009 } 2010 break; 2011 case 6: 2012 if (i == sh->qd_idx) 2013 return 0; /* It is the Q disk */ 2014 switch (algorithm) { 2015 case ALGORITHM_LEFT_ASYMMETRIC: 2016 case ALGORITHM_RIGHT_ASYMMETRIC: 2017 case ALGORITHM_ROTATING_ZERO_RESTART: 2018 case ALGORITHM_ROTATING_N_RESTART: 2019 if (sh->pd_idx == raid_disks-1) 2020 i--; /* Q D D D P */ 2021 else if (i > sh->pd_idx) 2022 i -= 2; /* D D P Q D */ 2023 break; 2024 case ALGORITHM_LEFT_SYMMETRIC: 2025 case ALGORITHM_RIGHT_SYMMETRIC: 2026 if (sh->pd_idx == raid_disks-1) 2027 i--; /* Q D D D P */ 2028 else { 2029 /* D D P Q D */ 2030 if (i < sh->pd_idx) 2031 i += raid_disks; 2032 i -= (sh->pd_idx + 2); 2033 } 2034 break; 2035 case ALGORITHM_PARITY_0: 2036 i -= 2; 2037 break; 2038 case ALGORITHM_PARITY_N: 2039 break; 2040 case ALGORITHM_ROTATING_N_CONTINUE: 2041 /* Like left_symmetric, but P is before Q */ 2042 if (sh->pd_idx == 0) 2043 i--; /* P D D D Q */ 2044 else { 2045 /* D D Q P D */ 2046 if (i < sh->pd_idx) 2047 i += raid_disks; 2048 i -= (sh->pd_idx + 1); 2049 } 2050 break; 2051 case ALGORITHM_LEFT_ASYMMETRIC_6: 2052 case ALGORITHM_RIGHT_ASYMMETRIC_6: 2053 if (i > sh->pd_idx) 2054 i--; 2055 break; 2056 case ALGORITHM_LEFT_SYMMETRIC_6: 2057 case ALGORITHM_RIGHT_SYMMETRIC_6: 2058 if (i < sh->pd_idx) 2059 i += data_disks + 1; 2060 i -= (sh->pd_idx + 1); 2061 break; 2062 case ALGORITHM_PARITY_0_6: 2063 i -= 1; 2064 break; 2065 default: 2066 BUG(); 2067 } 2068 break; 2069 } 2070 2071 chunk_number = stripe * data_disks + i; 2072 r_sector = chunk_number * sectors_per_chunk + chunk_offset; 2073 2074 check = raid5_compute_sector(conf, r_sector, 2075 previous, &dummy1, &sh2); 2076 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx 2077 || sh2.qd_idx != sh->qd_idx) { 2078 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n", 2079 mdname(conf->mddev)); 2080 return 0; 2081 } 2082 return r_sector; 2083 } 2084 2085 2086 static void 2087 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, 2088 int rcw, int expand) 2089 { 2090 int i, pd_idx = sh->pd_idx, disks = sh->disks; 2091 raid5_conf_t *conf = sh->raid_conf; 2092 int level = conf->level; 2093 2094 if (rcw) { 2095 /* if we are not expanding this is a proper write request, and 2096 * there will be bios with new data to be drained into the 2097 * stripe cache 2098 */ 2099 if (!expand) { 2100 sh->reconstruct_state = reconstruct_state_drain_run; 2101 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2102 } else 2103 sh->reconstruct_state = reconstruct_state_run; 2104 2105 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2106 2107 for (i = disks; i--; ) { 2108 struct r5dev *dev = &sh->dev[i]; 2109 2110 if (dev->towrite) { 2111 set_bit(R5_LOCKED, &dev->flags); 2112 set_bit(R5_Wantdrain, &dev->flags); 2113 if (!expand) 2114 clear_bit(R5_UPTODATE, &dev->flags); 2115 s->locked++; 2116 } 2117 } 2118 if (s->locked + conf->max_degraded == disks) 2119 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) 2120 atomic_inc(&conf->pending_full_writes); 2121 } else { 2122 BUG_ON(level == 6); 2123 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || 2124 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); 2125 2126 sh->reconstruct_state = reconstruct_state_prexor_drain_run; 2127 set_bit(STRIPE_OP_PREXOR, &s->ops_request); 2128 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); 2129 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); 2130 2131 for (i = disks; i--; ) { 2132 struct r5dev *dev = &sh->dev[i]; 2133 if (i == pd_idx) 2134 continue; 2135 2136 if (dev->towrite && 2137 (test_bit(R5_UPTODATE, &dev->flags) || 2138 test_bit(R5_Wantcompute, &dev->flags))) { 2139 set_bit(R5_Wantdrain, &dev->flags); 2140 set_bit(R5_LOCKED, &dev->flags); 2141 clear_bit(R5_UPTODATE, &dev->flags); 2142 s->locked++; 2143 } 2144 } 2145 } 2146 2147 /* keep the parity disk(s) locked while asynchronous operations 2148 * are in flight 2149 */ 2150 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); 2151 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2152 s->locked++; 2153 2154 if (level == 6) { 2155 int qd_idx = sh->qd_idx; 2156 struct r5dev *dev = &sh->dev[qd_idx]; 2157 2158 set_bit(R5_LOCKED, &dev->flags); 2159 clear_bit(R5_UPTODATE, &dev->flags); 2160 s->locked++; 2161 } 2162 2163 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", 2164 __func__, (unsigned long long)sh->sector, 2165 s->locked, s->ops_request); 2166 } 2167 2168 /* 2169 * Each stripe/dev can have one or more bion attached. 2170 * toread/towrite point to the first in a chain. 2171 * The bi_next chain must be in order. 2172 */ 2173 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 2174 { 2175 struct bio **bip; 2176 raid5_conf_t *conf = sh->raid_conf; 2177 int firstwrite=0; 2178 2179 pr_debug("adding bi b#%llu to stripe s#%llu\n", 2180 (unsigned long long)bi->bi_sector, 2181 (unsigned long long)sh->sector); 2182 2183 2184 spin_lock_irq(&conf->device_lock); 2185 if (forwrite) { 2186 bip = &sh->dev[dd_idx].towrite; 2187 if (*bip == NULL && sh->dev[dd_idx].written == NULL) 2188 firstwrite = 1; 2189 } else 2190 bip = &sh->dev[dd_idx].toread; 2191 while (*bip && (*bip)->bi_sector < bi->bi_sector) { 2192 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector) 2193 goto overlap; 2194 bip = & (*bip)->bi_next; 2195 } 2196 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9)) 2197 goto overlap; 2198 2199 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); 2200 if (*bip) 2201 bi->bi_next = *bip; 2202 *bip = bi; 2203 bi->bi_phys_segments++; 2204 2205 if (forwrite) { 2206 /* check if page is covered */ 2207 sector_t sector = sh->dev[dd_idx].sector; 2208 for (bi=sh->dev[dd_idx].towrite; 2209 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS && 2210 bi && bi->bi_sector <= sector; 2211 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) { 2212 if (bi->bi_sector + (bi->bi_size>>9) >= sector) 2213 sector = bi->bi_sector + (bi->bi_size>>9); 2214 } 2215 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS) 2216 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags); 2217 } 2218 spin_unlock_irq(&conf->device_lock); 2219 2220 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", 2221 (unsigned long long)(*bip)->bi_sector, 2222 (unsigned long long)sh->sector, dd_idx); 2223 2224 if (conf->mddev->bitmap && firstwrite) { 2225 bitmap_startwrite(conf->mddev->bitmap, sh->sector, 2226 STRIPE_SECTORS, 0); 2227 sh->bm_seq = conf->seq_flush+1; 2228 set_bit(STRIPE_BIT_DELAY, &sh->state); 2229 } 2230 return 1; 2231 2232 overlap: 2233 set_bit(R5_Overlap, &sh->dev[dd_idx].flags); 2234 spin_unlock_irq(&conf->device_lock); 2235 return 0; 2236 } 2237 2238 static void end_reshape(raid5_conf_t *conf); 2239 2240 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, 2241 struct stripe_head *sh) 2242 { 2243 int sectors_per_chunk = 2244 previous ? conf->prev_chunk_sectors : conf->chunk_sectors; 2245 int dd_idx; 2246 int chunk_offset = sector_div(stripe, sectors_per_chunk); 2247 int disks = previous ? conf->previous_raid_disks : conf->raid_disks; 2248 2249 raid5_compute_sector(conf, 2250 stripe * (disks - conf->max_degraded) 2251 *sectors_per_chunk + chunk_offset, 2252 previous, 2253 &dd_idx, sh); 2254 } 2255 2256 static void 2257 handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, 2258 struct stripe_head_state *s, int disks, 2259 struct bio **return_bi) 2260 { 2261 int i; 2262 for (i = disks; i--; ) { 2263 struct bio *bi; 2264 int bitmap_end = 0; 2265 2266 if (test_bit(R5_ReadError, &sh->dev[i].flags)) { 2267 mdk_rdev_t *rdev; 2268 rcu_read_lock(); 2269 rdev = rcu_dereference(conf->disks[i].rdev); 2270 if (rdev && test_bit(In_sync, &rdev->flags)) 2271 atomic_inc(&rdev->nr_pending); 2272 else 2273 rdev = NULL; 2274 rcu_read_unlock(); 2275 if (rdev) { 2276 if (!rdev_set_badblocks( 2277 rdev, 2278 sh->sector, 2279 STRIPE_SECTORS, 0)) 2280 md_error(conf->mddev, rdev); 2281 rdev_dec_pending(rdev, conf->mddev); 2282 } 2283 } 2284 spin_lock_irq(&conf->device_lock); 2285 /* fail all writes first */ 2286 bi = sh->dev[i].towrite; 2287 sh->dev[i].towrite = NULL; 2288 if (bi) { 2289 s->to_write--; 2290 bitmap_end = 1; 2291 } 2292 2293 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2294 wake_up(&conf->wait_for_overlap); 2295 2296 while (bi && bi->bi_sector < 2297 sh->dev[i].sector + STRIPE_SECTORS) { 2298 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); 2299 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2300 if (!raid5_dec_bi_phys_segments(bi)) { 2301 md_write_end(conf->mddev); 2302 bi->bi_next = *return_bi; 2303 *return_bi = bi; 2304 } 2305 bi = nextbi; 2306 } 2307 /* and fail all 'written' */ 2308 bi = sh->dev[i].written; 2309 sh->dev[i].written = NULL; 2310 if (bi) bitmap_end = 1; 2311 while (bi && bi->bi_sector < 2312 sh->dev[i].sector + STRIPE_SECTORS) { 2313 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); 2314 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2315 if (!raid5_dec_bi_phys_segments(bi)) { 2316 md_write_end(conf->mddev); 2317 bi->bi_next = *return_bi; 2318 *return_bi = bi; 2319 } 2320 bi = bi2; 2321 } 2322 2323 /* fail any reads if this device is non-operational and 2324 * the data has not reached the cache yet. 2325 */ 2326 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && 2327 (!test_bit(R5_Insync, &sh->dev[i].flags) || 2328 test_bit(R5_ReadError, &sh->dev[i].flags))) { 2329 bi = sh->dev[i].toread; 2330 sh->dev[i].toread = NULL; 2331 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) 2332 wake_up(&conf->wait_for_overlap); 2333 if (bi) s->to_read--; 2334 while (bi && bi->bi_sector < 2335 sh->dev[i].sector + STRIPE_SECTORS) { 2336 struct bio *nextbi = 2337 r5_next_bio(bi, sh->dev[i].sector); 2338 clear_bit(BIO_UPTODATE, &bi->bi_flags); 2339 if (!raid5_dec_bi_phys_segments(bi)) { 2340 bi->bi_next = *return_bi; 2341 *return_bi = bi; 2342 } 2343 bi = nextbi; 2344 } 2345 } 2346 spin_unlock_irq(&conf->device_lock); 2347 if (bitmap_end) 2348 bitmap_endwrite(conf->mddev->bitmap, sh->sector, 2349 STRIPE_SECTORS, 0, 0); 2350 /* If we were in the middle of a write the parity block might 2351 * still be locked - so just clear all R5_LOCKED flags 2352 */ 2353 clear_bit(R5_LOCKED, &sh->dev[i].flags); 2354 } 2355 2356 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2357 if (atomic_dec_and_test(&conf->pending_full_writes)) 2358 md_wakeup_thread(conf->mddev->thread); 2359 } 2360 2361 static void 2362 handle_failed_sync(raid5_conf_t *conf, struct stripe_head *sh, 2363 struct stripe_head_state *s) 2364 { 2365 int abort = 0; 2366 int i; 2367 2368 md_done_sync(conf->mddev, STRIPE_SECTORS, 0); 2369 clear_bit(STRIPE_SYNCING, &sh->state); 2370 s->syncing = 0; 2371 /* There is nothing more to do for sync/check/repair. 2372 * For recover we need to record a bad block on all 2373 * non-sync devices, or abort the recovery 2374 */ 2375 if (!test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) 2376 return; 2377 /* During recovery devices cannot be removed, so locking and 2378 * refcounting of rdevs is not needed 2379 */ 2380 for (i = 0; i < conf->raid_disks; i++) { 2381 mdk_rdev_t *rdev = conf->disks[i].rdev; 2382 if (!rdev 2383 || test_bit(Faulty, &rdev->flags) 2384 || test_bit(In_sync, &rdev->flags)) 2385 continue; 2386 if (!rdev_set_badblocks(rdev, sh->sector, 2387 STRIPE_SECTORS, 0)) 2388 abort = 1; 2389 } 2390 if (abort) { 2391 conf->recovery_disabled = conf->mddev->recovery_disabled; 2392 set_bit(MD_RECOVERY_INTR, &conf->mddev->recovery); 2393 } 2394 } 2395 2396 /* fetch_block - checks the given member device to see if its data needs 2397 * to be read or computed to satisfy a request. 2398 * 2399 * Returns 1 when no more member devices need to be checked, otherwise returns 2400 * 0 to tell the loop in handle_stripe_fill to continue 2401 */ 2402 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, 2403 int disk_idx, int disks) 2404 { 2405 struct r5dev *dev = &sh->dev[disk_idx]; 2406 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], 2407 &sh->dev[s->failed_num[1]] }; 2408 2409 /* is the data in this block needed, and can we get it? */ 2410 if (!test_bit(R5_LOCKED, &dev->flags) && 2411 !test_bit(R5_UPTODATE, &dev->flags) && 2412 (dev->toread || 2413 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || 2414 s->syncing || s->expanding || 2415 (s->failed >= 1 && fdev[0]->toread) || 2416 (s->failed >= 2 && fdev[1]->toread) || 2417 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && 2418 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || 2419 (sh->raid_conf->level == 6 && s->failed && s->to_write))) { 2420 /* we would like to get this block, possibly by computing it, 2421 * otherwise read it if the backing disk is insync 2422 */ 2423 BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); 2424 BUG_ON(test_bit(R5_Wantread, &dev->flags)); 2425 if ((s->uptodate == disks - 1) && 2426 (s->failed && (disk_idx == s->failed_num[0] || 2427 disk_idx == s->failed_num[1]))) { 2428 /* have disk failed, and we're requested to fetch it; 2429 * do compute it 2430 */ 2431 pr_debug("Computing stripe %llu block %d\n", 2432 (unsigned long long)sh->sector, disk_idx); 2433 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2434 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2435 set_bit(R5_Wantcompute, &dev->flags); 2436 sh->ops.target = disk_idx; 2437 sh->ops.target2 = -1; /* no 2nd target */ 2438 s->req_compute = 1; 2439 /* Careful: from this point on 'uptodate' is in the eye 2440 * of raid_run_ops which services 'compute' operations 2441 * before writes. R5_Wantcompute flags a block that will 2442 * be R5_UPTODATE by the time it is needed for a 2443 * subsequent operation. 2444 */ 2445 s->uptodate++; 2446 return 1; 2447 } else if (s->uptodate == disks-2 && s->failed >= 2) { 2448 /* Computing 2-failure is *very* expensive; only 2449 * do it if failed >= 2 2450 */ 2451 int other; 2452 for (other = disks; other--; ) { 2453 if (other == disk_idx) 2454 continue; 2455 if (!test_bit(R5_UPTODATE, 2456 &sh->dev[other].flags)) 2457 break; 2458 } 2459 BUG_ON(other < 0); 2460 pr_debug("Computing stripe %llu blocks %d,%d\n", 2461 (unsigned long long)sh->sector, 2462 disk_idx, other); 2463 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2464 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2465 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); 2466 set_bit(R5_Wantcompute, &sh->dev[other].flags); 2467 sh->ops.target = disk_idx; 2468 sh->ops.target2 = other; 2469 s->uptodate += 2; 2470 s->req_compute = 1; 2471 return 1; 2472 } else if (test_bit(R5_Insync, &dev->flags)) { 2473 set_bit(R5_LOCKED, &dev->flags); 2474 set_bit(R5_Wantread, &dev->flags); 2475 s->locked++; 2476 pr_debug("Reading block %d (sync=%d)\n", 2477 disk_idx, s->syncing); 2478 } 2479 } 2480 2481 return 0; 2482 } 2483 2484 /** 2485 * handle_stripe_fill - read or compute data to satisfy pending requests. 2486 */ 2487 static void handle_stripe_fill(struct stripe_head *sh, 2488 struct stripe_head_state *s, 2489 int disks) 2490 { 2491 int i; 2492 2493 /* look for blocks to read/compute, skip this if a compute 2494 * is already in flight, or if the stripe contents are in the 2495 * midst of changing due to a write 2496 */ 2497 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && 2498 !sh->reconstruct_state) 2499 for (i = disks; i--; ) 2500 if (fetch_block(sh, s, i, disks)) 2501 break; 2502 set_bit(STRIPE_HANDLE, &sh->state); 2503 } 2504 2505 2506 /* handle_stripe_clean_event 2507 * any written block on an uptodate or failed drive can be returned. 2508 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but 2509 * never LOCKED, so we don't need to test 'failed' directly. 2510 */ 2511 static void handle_stripe_clean_event(raid5_conf_t *conf, 2512 struct stripe_head *sh, int disks, struct bio **return_bi) 2513 { 2514 int i; 2515 struct r5dev *dev; 2516 2517 for (i = disks; i--; ) 2518 if (sh->dev[i].written) { 2519 dev = &sh->dev[i]; 2520 if (!test_bit(R5_LOCKED, &dev->flags) && 2521 test_bit(R5_UPTODATE, &dev->flags)) { 2522 /* We can return any write requests */ 2523 struct bio *wbi, *wbi2; 2524 int bitmap_end = 0; 2525 pr_debug("Return write for disc %d\n", i); 2526 spin_lock_irq(&conf->device_lock); 2527 wbi = dev->written; 2528 dev->written = NULL; 2529 while (wbi && wbi->bi_sector < 2530 dev->sector + STRIPE_SECTORS) { 2531 wbi2 = r5_next_bio(wbi, dev->sector); 2532 if (!raid5_dec_bi_phys_segments(wbi)) { 2533 md_write_end(conf->mddev); 2534 wbi->bi_next = *return_bi; 2535 *return_bi = wbi; 2536 } 2537 wbi = wbi2; 2538 } 2539 if (dev->towrite == NULL) 2540 bitmap_end = 1; 2541 spin_unlock_irq(&conf->device_lock); 2542 if (bitmap_end) 2543 bitmap_endwrite(conf->mddev->bitmap, 2544 sh->sector, 2545 STRIPE_SECTORS, 2546 !test_bit(STRIPE_DEGRADED, &sh->state), 2547 0); 2548 } 2549 } 2550 2551 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) 2552 if (atomic_dec_and_test(&conf->pending_full_writes)) 2553 md_wakeup_thread(conf->mddev->thread); 2554 } 2555 2556 static void handle_stripe_dirtying(raid5_conf_t *conf, 2557 struct stripe_head *sh, 2558 struct stripe_head_state *s, 2559 int disks) 2560 { 2561 int rmw = 0, rcw = 0, i; 2562 if (conf->max_degraded == 2) { 2563 /* RAID6 requires 'rcw' in current implementation 2564 * Calculate the real rcw later - for now fake it 2565 * look like rcw is cheaper 2566 */ 2567 rcw = 1; rmw = 2; 2568 } else for (i = disks; i--; ) { 2569 /* would I have to read this buffer for read_modify_write */ 2570 struct r5dev *dev = &sh->dev[i]; 2571 if ((dev->towrite || i == sh->pd_idx) && 2572 !test_bit(R5_LOCKED, &dev->flags) && 2573 !(test_bit(R5_UPTODATE, &dev->flags) || 2574 test_bit(R5_Wantcompute, &dev->flags))) { 2575 if (test_bit(R5_Insync, &dev->flags)) 2576 rmw++; 2577 else 2578 rmw += 2*disks; /* cannot read it */ 2579 } 2580 /* Would I have to read this buffer for reconstruct_write */ 2581 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx && 2582 !test_bit(R5_LOCKED, &dev->flags) && 2583 !(test_bit(R5_UPTODATE, &dev->flags) || 2584 test_bit(R5_Wantcompute, &dev->flags))) { 2585 if (test_bit(R5_Insync, &dev->flags)) rcw++; 2586 else 2587 rcw += 2*disks; 2588 } 2589 } 2590 pr_debug("for sector %llu, rmw=%d rcw=%d\n", 2591 (unsigned long long)sh->sector, rmw, rcw); 2592 set_bit(STRIPE_HANDLE, &sh->state); 2593 if (rmw < rcw && rmw > 0) 2594 /* prefer read-modify-write, but need to get some data */ 2595 for (i = disks; i--; ) { 2596 struct r5dev *dev = &sh->dev[i]; 2597 if ((dev->towrite || i == sh->pd_idx) && 2598 !test_bit(R5_LOCKED, &dev->flags) && 2599 !(test_bit(R5_UPTODATE, &dev->flags) || 2600 test_bit(R5_Wantcompute, &dev->flags)) && 2601 test_bit(R5_Insync, &dev->flags)) { 2602 if ( 2603 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2604 pr_debug("Read_old block " 2605 "%d for r-m-w\n", i); 2606 set_bit(R5_LOCKED, &dev->flags); 2607 set_bit(R5_Wantread, &dev->flags); 2608 s->locked++; 2609 } else { 2610 set_bit(STRIPE_DELAYED, &sh->state); 2611 set_bit(STRIPE_HANDLE, &sh->state); 2612 } 2613 } 2614 } 2615 if (rcw <= rmw && rcw > 0) { 2616 /* want reconstruct write, but need to get some data */ 2617 rcw = 0; 2618 for (i = disks; i--; ) { 2619 struct r5dev *dev = &sh->dev[i]; 2620 if (!test_bit(R5_OVERWRITE, &dev->flags) && 2621 i != sh->pd_idx && i != sh->qd_idx && 2622 !test_bit(R5_LOCKED, &dev->flags) && 2623 !(test_bit(R5_UPTODATE, &dev->flags) || 2624 test_bit(R5_Wantcompute, &dev->flags))) { 2625 rcw++; 2626 if (!test_bit(R5_Insync, &dev->flags)) 2627 continue; /* it's a failed drive */ 2628 if ( 2629 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { 2630 pr_debug("Read_old block " 2631 "%d for Reconstruct\n", i); 2632 set_bit(R5_LOCKED, &dev->flags); 2633 set_bit(R5_Wantread, &dev->flags); 2634 s->locked++; 2635 } else { 2636 set_bit(STRIPE_DELAYED, &sh->state); 2637 set_bit(STRIPE_HANDLE, &sh->state); 2638 } 2639 } 2640 } 2641 } 2642 /* now if nothing is locked, and if we have enough data, 2643 * we can start a write request 2644 */ 2645 /* since handle_stripe can be called at any time we need to handle the 2646 * case where a compute block operation has been submitted and then a 2647 * subsequent call wants to start a write request. raid_run_ops only 2648 * handles the case where compute block and reconstruct are requested 2649 * simultaneously. If this is not the case then new writes need to be 2650 * held off until the compute completes. 2651 */ 2652 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && 2653 (s->locked == 0 && (rcw == 0 || rmw == 0) && 2654 !test_bit(STRIPE_BIT_DELAY, &sh->state))) 2655 schedule_reconstruction(sh, s, rcw == 0, 0); 2656 } 2657 2658 static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, 2659 struct stripe_head_state *s, int disks) 2660 { 2661 struct r5dev *dev = NULL; 2662 2663 set_bit(STRIPE_HANDLE, &sh->state); 2664 2665 switch (sh->check_state) { 2666 case check_state_idle: 2667 /* start a new check operation if there are no failures */ 2668 if (s->failed == 0) { 2669 BUG_ON(s->uptodate != disks); 2670 sh->check_state = check_state_run; 2671 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2672 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags); 2673 s->uptodate--; 2674 break; 2675 } 2676 dev = &sh->dev[s->failed_num[0]]; 2677 /* fall through */ 2678 case check_state_compute_result: 2679 sh->check_state = check_state_idle; 2680 if (!dev) 2681 dev = &sh->dev[sh->pd_idx]; 2682 2683 /* check that a write has not made the stripe insync */ 2684 if (test_bit(STRIPE_INSYNC, &sh->state)) 2685 break; 2686 2687 /* either failed parity check, or recovery is happening */ 2688 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); 2689 BUG_ON(s->uptodate != disks); 2690 2691 set_bit(R5_LOCKED, &dev->flags); 2692 s->locked++; 2693 set_bit(R5_Wantwrite, &dev->flags); 2694 2695 clear_bit(STRIPE_DEGRADED, &sh->state); 2696 set_bit(STRIPE_INSYNC, &sh->state); 2697 break; 2698 case check_state_run: 2699 break; /* we will be called again upon completion */ 2700 case check_state_check_result: 2701 sh->check_state = check_state_idle; 2702 2703 /* if a failure occurred during the check operation, leave 2704 * STRIPE_INSYNC not set and let the stripe be handled again 2705 */ 2706 if (s->failed) 2707 break; 2708 2709 /* handle a successful check operation, if parity is correct 2710 * we are done. Otherwise update the mismatch count and repair 2711 * parity if !MD_RECOVERY_CHECK 2712 */ 2713 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0) 2714 /* parity is correct (on disc, 2715 * not in buffer any more) 2716 */ 2717 set_bit(STRIPE_INSYNC, &sh->state); 2718 else { 2719 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2720 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2721 /* don't try to repair!! */ 2722 set_bit(STRIPE_INSYNC, &sh->state); 2723 else { 2724 sh->check_state = check_state_compute_run; 2725 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2726 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2727 set_bit(R5_Wantcompute, 2728 &sh->dev[sh->pd_idx].flags); 2729 sh->ops.target = sh->pd_idx; 2730 sh->ops.target2 = -1; 2731 s->uptodate++; 2732 } 2733 } 2734 break; 2735 case check_state_compute_run: 2736 break; 2737 default: 2738 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2739 __func__, sh->check_state, 2740 (unsigned long long) sh->sector); 2741 BUG(); 2742 } 2743 } 2744 2745 2746 static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh, 2747 struct stripe_head_state *s, 2748 int disks) 2749 { 2750 int pd_idx = sh->pd_idx; 2751 int qd_idx = sh->qd_idx; 2752 struct r5dev *dev; 2753 2754 set_bit(STRIPE_HANDLE, &sh->state); 2755 2756 BUG_ON(s->failed > 2); 2757 2758 /* Want to check and possibly repair P and Q. 2759 * However there could be one 'failed' device, in which 2760 * case we can only check one of them, possibly using the 2761 * other to generate missing data 2762 */ 2763 2764 switch (sh->check_state) { 2765 case check_state_idle: 2766 /* start a new check operation if there are < 2 failures */ 2767 if (s->failed == s->q_failed) { 2768 /* The only possible failed device holds Q, so it 2769 * makes sense to check P (If anything else were failed, 2770 * we would have used P to recreate it). 2771 */ 2772 sh->check_state = check_state_run; 2773 } 2774 if (!s->q_failed && s->failed < 2) { 2775 /* Q is not failed, and we didn't use it to generate 2776 * anything, so it makes sense to check it 2777 */ 2778 if (sh->check_state == check_state_run) 2779 sh->check_state = check_state_run_pq; 2780 else 2781 sh->check_state = check_state_run_q; 2782 } 2783 2784 /* discard potentially stale zero_sum_result */ 2785 sh->ops.zero_sum_result = 0; 2786 2787 if (sh->check_state == check_state_run) { 2788 /* async_xor_zero_sum destroys the contents of P */ 2789 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 2790 s->uptodate--; 2791 } 2792 if (sh->check_state >= check_state_run && 2793 sh->check_state <= check_state_run_pq) { 2794 /* async_syndrome_zero_sum preserves P and Q, so 2795 * no need to mark them !uptodate here 2796 */ 2797 set_bit(STRIPE_OP_CHECK, &s->ops_request); 2798 break; 2799 } 2800 2801 /* we have 2-disk failure */ 2802 BUG_ON(s->failed != 2); 2803 /* fall through */ 2804 case check_state_compute_result: 2805 sh->check_state = check_state_idle; 2806 2807 /* check that a write has not made the stripe insync */ 2808 if (test_bit(STRIPE_INSYNC, &sh->state)) 2809 break; 2810 2811 /* now write out any block on a failed drive, 2812 * or P or Q if they were recomputed 2813 */ 2814 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ 2815 if (s->failed == 2) { 2816 dev = &sh->dev[s->failed_num[1]]; 2817 s->locked++; 2818 set_bit(R5_LOCKED, &dev->flags); 2819 set_bit(R5_Wantwrite, &dev->flags); 2820 } 2821 if (s->failed >= 1) { 2822 dev = &sh->dev[s->failed_num[0]]; 2823 s->locked++; 2824 set_bit(R5_LOCKED, &dev->flags); 2825 set_bit(R5_Wantwrite, &dev->flags); 2826 } 2827 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2828 dev = &sh->dev[pd_idx]; 2829 s->locked++; 2830 set_bit(R5_LOCKED, &dev->flags); 2831 set_bit(R5_Wantwrite, &dev->flags); 2832 } 2833 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2834 dev = &sh->dev[qd_idx]; 2835 s->locked++; 2836 set_bit(R5_LOCKED, &dev->flags); 2837 set_bit(R5_Wantwrite, &dev->flags); 2838 } 2839 clear_bit(STRIPE_DEGRADED, &sh->state); 2840 2841 set_bit(STRIPE_INSYNC, &sh->state); 2842 break; 2843 case check_state_run: 2844 case check_state_run_q: 2845 case check_state_run_pq: 2846 break; /* we will be called again upon completion */ 2847 case check_state_check_result: 2848 sh->check_state = check_state_idle; 2849 2850 /* handle a successful check operation, if parity is correct 2851 * we are done. Otherwise update the mismatch count and repair 2852 * parity if !MD_RECOVERY_CHECK 2853 */ 2854 if (sh->ops.zero_sum_result == 0) { 2855 /* both parities are correct */ 2856 if (!s->failed) 2857 set_bit(STRIPE_INSYNC, &sh->state); 2858 else { 2859 /* in contrast to the raid5 case we can validate 2860 * parity, but still have a failure to write 2861 * back 2862 */ 2863 sh->check_state = check_state_compute_result; 2864 /* Returning at this point means that we may go 2865 * off and bring p and/or q uptodate again so 2866 * we make sure to check zero_sum_result again 2867 * to verify if p or q need writeback 2868 */ 2869 } 2870 } else { 2871 conf->mddev->resync_mismatches += STRIPE_SECTORS; 2872 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) 2873 /* don't try to repair!! */ 2874 set_bit(STRIPE_INSYNC, &sh->state); 2875 else { 2876 int *target = &sh->ops.target; 2877 2878 sh->ops.target = -1; 2879 sh->ops.target2 = -1; 2880 sh->check_state = check_state_compute_run; 2881 set_bit(STRIPE_COMPUTE_RUN, &sh->state); 2882 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); 2883 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) { 2884 set_bit(R5_Wantcompute, 2885 &sh->dev[pd_idx].flags); 2886 *target = pd_idx; 2887 target = &sh->ops.target2; 2888 s->uptodate++; 2889 } 2890 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) { 2891 set_bit(R5_Wantcompute, 2892 &sh->dev[qd_idx].flags); 2893 *target = qd_idx; 2894 s->uptodate++; 2895 } 2896 } 2897 } 2898 break; 2899 case check_state_compute_run: 2900 break; 2901 default: 2902 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n", 2903 __func__, sh->check_state, 2904 (unsigned long long) sh->sector); 2905 BUG(); 2906 } 2907 } 2908 2909 static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh) 2910 { 2911 int i; 2912 2913 /* We have read all the blocks in this stripe and now we need to 2914 * copy some of them into a target stripe for expand. 2915 */ 2916 struct dma_async_tx_descriptor *tx = NULL; 2917 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2918 for (i = 0; i < sh->disks; i++) 2919 if (i != sh->pd_idx && i != sh->qd_idx) { 2920 int dd_idx, j; 2921 struct stripe_head *sh2; 2922 struct async_submit_ctl submit; 2923 2924 sector_t bn = compute_blocknr(sh, i, 1); 2925 sector_t s = raid5_compute_sector(conf, bn, 0, 2926 &dd_idx, NULL); 2927 sh2 = get_active_stripe(conf, s, 0, 1, 1); 2928 if (sh2 == NULL) 2929 /* so far only the early blocks of this stripe 2930 * have been requested. When later blocks 2931 * get requested, we will try again 2932 */ 2933 continue; 2934 if (!test_bit(STRIPE_EXPANDING, &sh2->state) || 2935 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) { 2936 /* must have already done this block */ 2937 release_stripe(sh2); 2938 continue; 2939 } 2940 2941 /* place all the copies on one channel */ 2942 init_async_submit(&submit, 0, tx, NULL, NULL, NULL); 2943 tx = async_memcpy(sh2->dev[dd_idx].page, 2944 sh->dev[i].page, 0, 0, STRIPE_SIZE, 2945 &submit); 2946 2947 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags); 2948 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags); 2949 for (j = 0; j < conf->raid_disks; j++) 2950 if (j != sh2->pd_idx && 2951 j != sh2->qd_idx && 2952 !test_bit(R5_Expanded, &sh2->dev[j].flags)) 2953 break; 2954 if (j == conf->raid_disks) { 2955 set_bit(STRIPE_EXPAND_READY, &sh2->state); 2956 set_bit(STRIPE_HANDLE, &sh2->state); 2957 } 2958 release_stripe(sh2); 2959 2960 } 2961 /* done submitting copies, wait for them to complete */ 2962 if (tx) { 2963 async_tx_ack(tx); 2964 dma_wait_for_async_tx(tx); 2965 } 2966 } 2967 2968 2969 /* 2970 * handle_stripe - do things to a stripe. 2971 * 2972 * We lock the stripe and then examine the state of various bits 2973 * to see what needs to be done. 2974 * Possible results: 2975 * return some read request which now have data 2976 * return some write requests which are safely on disc 2977 * schedule a read on some buffers 2978 * schedule a write of some buffers 2979 * return confirmation of parity correctness 2980 * 2981 * buffers are taken off read_list or write_list, and bh_cache buffers 2982 * get BH_Lock set before the stripe lock is released. 2983 * 2984 */ 2985 2986 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) 2987 { 2988 raid5_conf_t *conf = sh->raid_conf; 2989 int disks = sh->disks; 2990 struct r5dev *dev; 2991 int i; 2992 2993 memset(s, 0, sizeof(*s)); 2994 2995 s->syncing = test_bit(STRIPE_SYNCING, &sh->state); 2996 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); 2997 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); 2998 s->failed_num[0] = -1; 2999 s->failed_num[1] = -1; 3000 3001 /* Now to look around and see what can be done */ 3002 rcu_read_lock(); 3003 spin_lock_irq(&conf->device_lock); 3004 for (i=disks; i--; ) { 3005 mdk_rdev_t *rdev; 3006 sector_t first_bad; 3007 int bad_sectors; 3008 int is_bad = 0; 3009 3010 dev = &sh->dev[i]; 3011 3012 pr_debug("check %d: state 0x%lx read %p write %p written %p\n", 3013 i, dev->flags, dev->toread, dev->towrite, dev->written); 3014 /* maybe we can reply to a read 3015 * 3016 * new wantfill requests are only permitted while 3017 * ops_complete_biofill is guaranteed to be inactive 3018 */ 3019 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && 3020 !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) 3021 set_bit(R5_Wantfill, &dev->flags); 3022 3023 /* now count some things */ 3024 if (test_bit(R5_LOCKED, &dev->flags)) 3025 s->locked++; 3026 if (test_bit(R5_UPTODATE, &dev->flags)) 3027 s->uptodate++; 3028 if (test_bit(R5_Wantcompute, &dev->flags)) { 3029 s->compute++; 3030 BUG_ON(s->compute > 2); 3031 } 3032 3033 if (test_bit(R5_Wantfill, &dev->flags)) 3034 s->to_fill++; 3035 else if (dev->toread) 3036 s->to_read++; 3037 if (dev->towrite) { 3038 s->to_write++; 3039 if (!test_bit(R5_OVERWRITE, &dev->flags)) 3040 s->non_overwrite++; 3041 } 3042 if (dev->written) 3043 s->written++; 3044 rdev = rcu_dereference(conf->disks[i].rdev); 3045 if (rdev) { 3046 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS, 3047 &first_bad, &bad_sectors); 3048 if (s->blocked_rdev == NULL 3049 && (test_bit(Blocked, &rdev->flags) 3050 || is_bad < 0)) { 3051 if (is_bad < 0) 3052 set_bit(BlockedBadBlocks, 3053 &rdev->flags); 3054 s->blocked_rdev = rdev; 3055 atomic_inc(&rdev->nr_pending); 3056 } 3057 } 3058 clear_bit(R5_Insync, &dev->flags); 3059 if (!rdev) 3060 /* Not in-sync */; 3061 else if (is_bad) { 3062 /* also not in-sync */ 3063 if (!test_bit(WriteErrorSeen, &rdev->flags)) { 3064 /* treat as in-sync, but with a read error 3065 * which we can now try to correct 3066 */ 3067 set_bit(R5_Insync, &dev->flags); 3068 set_bit(R5_ReadError, &dev->flags); 3069 } 3070 } else if (test_bit(In_sync, &rdev->flags)) 3071 set_bit(R5_Insync, &dev->flags); 3072 else { 3073 /* in sync if before recovery_offset */ 3074 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) 3075 set_bit(R5_Insync, &dev->flags); 3076 } 3077 if (test_bit(R5_WriteError, &dev->flags)) { 3078 clear_bit(R5_Insync, &dev->flags); 3079 if (!test_bit(Faulty, &rdev->flags)) { 3080 s->handle_bad_blocks = 1; 3081 atomic_inc(&rdev->nr_pending); 3082 } else 3083 clear_bit(R5_WriteError, &dev->flags); 3084 } 3085 if (test_bit(R5_MadeGood, &dev->flags)) { 3086 if (!test_bit(Faulty, &rdev->flags)) { 3087 s->handle_bad_blocks = 1; 3088 atomic_inc(&rdev->nr_pending); 3089 } else 3090 clear_bit(R5_MadeGood, &dev->flags); 3091 } 3092 if (!test_bit(R5_Insync, &dev->flags)) { 3093 /* The ReadError flag will just be confusing now */ 3094 clear_bit(R5_ReadError, &dev->flags); 3095 clear_bit(R5_ReWrite, &dev->flags); 3096 } 3097 if (test_bit(R5_ReadError, &dev->flags)) 3098 clear_bit(R5_Insync, &dev->flags); 3099 if (!test_bit(R5_Insync, &dev->flags)) { 3100 if (s->failed < 2) 3101 s->failed_num[s->failed] = i; 3102 s->failed++; 3103 } 3104 } 3105 spin_unlock_irq(&conf->device_lock); 3106 rcu_read_unlock(); 3107 } 3108 3109 static void handle_stripe(struct stripe_head *sh) 3110 { 3111 struct stripe_head_state s; 3112 raid5_conf_t *conf = sh->raid_conf; 3113 int i; 3114 int prexor; 3115 int disks = sh->disks; 3116 struct r5dev *pdev, *qdev; 3117 3118 clear_bit(STRIPE_HANDLE, &sh->state); 3119 if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) { 3120 /* already being handled, ensure it gets handled 3121 * again when current action finishes */ 3122 set_bit(STRIPE_HANDLE, &sh->state); 3123 return; 3124 } 3125 3126 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { 3127 set_bit(STRIPE_SYNCING, &sh->state); 3128 clear_bit(STRIPE_INSYNC, &sh->state); 3129 } 3130 clear_bit(STRIPE_DELAYED, &sh->state); 3131 3132 pr_debug("handling stripe %llu, state=%#lx cnt=%d, " 3133 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", 3134 (unsigned long long)sh->sector, sh->state, 3135 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, 3136 sh->check_state, sh->reconstruct_state); 3137 3138 analyse_stripe(sh, &s); 3139 3140 if (s.handle_bad_blocks) { 3141 set_bit(STRIPE_HANDLE, &sh->state); 3142 goto finish; 3143 } 3144 3145 if (unlikely(s.blocked_rdev)) { 3146 if (s.syncing || s.expanding || s.expanded || 3147 s.to_write || s.written) { 3148 set_bit(STRIPE_HANDLE, &sh->state); 3149 goto finish; 3150 } 3151 /* There is nothing for the blocked_rdev to block */ 3152 rdev_dec_pending(s.blocked_rdev, conf->mddev); 3153 s.blocked_rdev = NULL; 3154 } 3155 3156 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { 3157 set_bit(STRIPE_OP_BIOFILL, &s.ops_request); 3158 set_bit(STRIPE_BIOFILL_RUN, &sh->state); 3159 } 3160 3161 pr_debug("locked=%d uptodate=%d to_read=%d" 3162 " to_write=%d failed=%d failed_num=%d,%d\n", 3163 s.locked, s.uptodate, s.to_read, s.to_write, s.failed, 3164 s.failed_num[0], s.failed_num[1]); 3165 /* check if the array has lost more than max_degraded devices and, 3166 * if so, some requests might need to be failed. 3167 */ 3168 if (s.failed > conf->max_degraded && s.to_read+s.to_write+s.written) 3169 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi); 3170 if (s.failed > conf->max_degraded && s.syncing) 3171 handle_failed_sync(conf, sh, &s); 3172 3173 /* 3174 * might be able to return some write requests if the parity blocks 3175 * are safe, or on a failed drive 3176 */ 3177 pdev = &sh->dev[sh->pd_idx]; 3178 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx) 3179 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx); 3180 qdev = &sh->dev[sh->qd_idx]; 3181 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx) 3182 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx) 3183 || conf->level < 6; 3184 3185 if (s.written && 3186 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags) 3187 && !test_bit(R5_LOCKED, &pdev->flags) 3188 && test_bit(R5_UPTODATE, &pdev->flags)))) && 3189 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags) 3190 && !test_bit(R5_LOCKED, &qdev->flags) 3191 && test_bit(R5_UPTODATE, &qdev->flags))))) 3192 handle_stripe_clean_event(conf, sh, disks, &s.return_bi); 3193 3194 /* Now we might consider reading some blocks, either to check/generate 3195 * parity, or to satisfy requests 3196 * or to load a block that is being partially written. 3197 */ 3198 if (s.to_read || s.non_overwrite 3199 || (conf->level == 6 && s.to_write && s.failed) 3200 || (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding) 3201 handle_stripe_fill(sh, &s, disks); 3202 3203 /* Now we check to see if any write operations have recently 3204 * completed 3205 */ 3206 prexor = 0; 3207 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result) 3208 prexor = 1; 3209 if (sh->reconstruct_state == reconstruct_state_drain_result || 3210 sh->reconstruct_state == reconstruct_state_prexor_drain_result) { 3211 sh->reconstruct_state = reconstruct_state_idle; 3212 3213 /* All the 'written' buffers and the parity block are ready to 3214 * be written back to disk 3215 */ 3216 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags)); 3217 BUG_ON(sh->qd_idx >= 0 && 3218 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags)); 3219 for (i = disks; i--; ) { 3220 struct r5dev *dev = &sh->dev[i]; 3221 if (test_bit(R5_LOCKED, &dev->flags) && 3222 (i == sh->pd_idx || i == sh->qd_idx || 3223 dev->written)) { 3224 pr_debug("Writing block %d\n", i); 3225 set_bit(R5_Wantwrite, &dev->flags); 3226 if (prexor) 3227 continue; 3228 if (!test_bit(R5_Insync, &dev->flags) || 3229 ((i == sh->pd_idx || i == sh->qd_idx) && 3230 s.failed == 0)) 3231 set_bit(STRIPE_INSYNC, &sh->state); 3232 } 3233 } 3234 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3235 s.dec_preread_active = 1; 3236 } 3237 3238 /* Now to consider new write requests and what else, if anything 3239 * should be read. We do not handle new writes when: 3240 * 1/ A 'write' operation (copy+xor) is already in flight. 3241 * 2/ A 'check' operation is in flight, as it may clobber the parity 3242 * block. 3243 */ 3244 if (s.to_write && !sh->reconstruct_state && !sh->check_state) 3245 handle_stripe_dirtying(conf, sh, &s, disks); 3246 3247 /* maybe we need to check and possibly fix the parity for this stripe 3248 * Any reads will already have been scheduled, so we just see if enough 3249 * data is available. The parity check is held off while parity 3250 * dependent operations are in flight. 3251 */ 3252 if (sh->check_state || 3253 (s.syncing && s.locked == 0 && 3254 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) && 3255 !test_bit(STRIPE_INSYNC, &sh->state))) { 3256 if (conf->level == 6) 3257 handle_parity_checks6(conf, sh, &s, disks); 3258 else 3259 handle_parity_checks5(conf, sh, &s, disks); 3260 } 3261 3262 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) { 3263 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3264 clear_bit(STRIPE_SYNCING, &sh->state); 3265 } 3266 3267 /* If the failed drives are just a ReadError, then we might need 3268 * to progress the repair/check process 3269 */ 3270 if (s.failed <= conf->max_degraded && !conf->mddev->ro) 3271 for (i = 0; i < s.failed; i++) { 3272 struct r5dev *dev = &sh->dev[s.failed_num[i]]; 3273 if (test_bit(R5_ReadError, &dev->flags) 3274 && !test_bit(R5_LOCKED, &dev->flags) 3275 && test_bit(R5_UPTODATE, &dev->flags) 3276 ) { 3277 if (!test_bit(R5_ReWrite, &dev->flags)) { 3278 set_bit(R5_Wantwrite, &dev->flags); 3279 set_bit(R5_ReWrite, &dev->flags); 3280 set_bit(R5_LOCKED, &dev->flags); 3281 s.locked++; 3282 } else { 3283 /* let's read it back */ 3284 set_bit(R5_Wantread, &dev->flags); 3285 set_bit(R5_LOCKED, &dev->flags); 3286 s.locked++; 3287 } 3288 } 3289 } 3290 3291 3292 /* Finish reconstruct operations initiated by the expansion process */ 3293 if (sh->reconstruct_state == reconstruct_state_result) { 3294 struct stripe_head *sh_src 3295 = get_active_stripe(conf, sh->sector, 1, 1, 1); 3296 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) { 3297 /* sh cannot be written until sh_src has been read. 3298 * so arrange for sh to be delayed a little 3299 */ 3300 set_bit(STRIPE_DELAYED, &sh->state); 3301 set_bit(STRIPE_HANDLE, &sh->state); 3302 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, 3303 &sh_src->state)) 3304 atomic_inc(&conf->preread_active_stripes); 3305 release_stripe(sh_src); 3306 goto finish; 3307 } 3308 if (sh_src) 3309 release_stripe(sh_src); 3310 3311 sh->reconstruct_state = reconstruct_state_idle; 3312 clear_bit(STRIPE_EXPANDING, &sh->state); 3313 for (i = conf->raid_disks; i--; ) { 3314 set_bit(R5_Wantwrite, &sh->dev[i].flags); 3315 set_bit(R5_LOCKED, &sh->dev[i].flags); 3316 s.locked++; 3317 } 3318 } 3319 3320 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && 3321 !sh->reconstruct_state) { 3322 /* Need to write out all blocks after computing parity */ 3323 sh->disks = conf->raid_disks; 3324 stripe_set_idx(sh->sector, conf, 0, sh); 3325 schedule_reconstruction(sh, &s, 1, 1); 3326 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { 3327 clear_bit(STRIPE_EXPAND_READY, &sh->state); 3328 atomic_dec(&conf->reshape_stripes); 3329 wake_up(&conf->wait_for_overlap); 3330 md_done_sync(conf->mddev, STRIPE_SECTORS, 1); 3331 } 3332 3333 if (s.expanding && s.locked == 0 && 3334 !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) 3335 handle_stripe_expansion(conf, sh); 3336 3337 finish: 3338 /* wait for this device to become unblocked */ 3339 if (conf->mddev->external && unlikely(s.blocked_rdev)) 3340 md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev); 3341 3342 if (s.handle_bad_blocks) 3343 for (i = disks; i--; ) { 3344 mdk_rdev_t *rdev; 3345 struct r5dev *dev = &sh->dev[i]; 3346 if (test_and_clear_bit(R5_WriteError, &dev->flags)) { 3347 /* We own a safe reference to the rdev */ 3348 rdev = conf->disks[i].rdev; 3349 if (!rdev_set_badblocks(rdev, sh->sector, 3350 STRIPE_SECTORS, 0)) 3351 md_error(conf->mddev, rdev); 3352 rdev_dec_pending(rdev, conf->mddev); 3353 } 3354 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) { 3355 rdev = conf->disks[i].rdev; 3356 rdev_clear_badblocks(rdev, sh->sector, 3357 STRIPE_SECTORS); 3358 rdev_dec_pending(rdev, conf->mddev); 3359 } 3360 } 3361 3362 if (s.ops_request) 3363 raid_run_ops(sh, s.ops_request); 3364 3365 ops_run_io(sh, &s); 3366 3367 if (s.dec_preread_active) { 3368 /* We delay this until after ops_run_io so that if make_request 3369 * is waiting on a flush, it won't continue until the writes 3370 * have actually been submitted. 3371 */ 3372 atomic_dec(&conf->preread_active_stripes); 3373 if (atomic_read(&conf->preread_active_stripes) < 3374 IO_THRESHOLD) 3375 md_wakeup_thread(conf->mddev->thread); 3376 } 3377 3378 return_io(s.return_bi); 3379 3380 clear_bit(STRIPE_ACTIVE, &sh->state); 3381 } 3382 3383 static void raid5_activate_delayed(raid5_conf_t *conf) 3384 { 3385 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 3386 while (!list_empty(&conf->delayed_list)) { 3387 struct list_head *l = conf->delayed_list.next; 3388 struct stripe_head *sh; 3389 sh = list_entry(l, struct stripe_head, lru); 3390 list_del_init(l); 3391 clear_bit(STRIPE_DELAYED, &sh->state); 3392 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3393 atomic_inc(&conf->preread_active_stripes); 3394 list_add_tail(&sh->lru, &conf->hold_list); 3395 } 3396 } 3397 } 3398 3399 static void activate_bit_delay(raid5_conf_t *conf) 3400 { 3401 /* device_lock is held */ 3402 struct list_head head; 3403 list_add(&head, &conf->bitmap_list); 3404 list_del_init(&conf->bitmap_list); 3405 while (!list_empty(&head)) { 3406 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); 3407 list_del_init(&sh->lru); 3408 atomic_inc(&sh->count); 3409 __release_stripe(conf, sh); 3410 } 3411 } 3412 3413 int md_raid5_congested(mddev_t *mddev, int bits) 3414 { 3415 raid5_conf_t *conf = mddev->private; 3416 3417 /* No difference between reads and writes. Just check 3418 * how busy the stripe_cache is 3419 */ 3420 3421 if (conf->inactive_blocked) 3422 return 1; 3423 if (conf->quiesce) 3424 return 1; 3425 if (list_empty_careful(&conf->inactive_list)) 3426 return 1; 3427 3428 return 0; 3429 } 3430 EXPORT_SYMBOL_GPL(md_raid5_congested); 3431 3432 static int raid5_congested(void *data, int bits) 3433 { 3434 mddev_t *mddev = data; 3435 3436 return mddev_congested(mddev, bits) || 3437 md_raid5_congested(mddev, bits); 3438 } 3439 3440 /* We want read requests to align with chunks where possible, 3441 * but write requests don't need to. 3442 */ 3443 static int raid5_mergeable_bvec(struct request_queue *q, 3444 struct bvec_merge_data *bvm, 3445 struct bio_vec *biovec) 3446 { 3447 mddev_t *mddev = q->queuedata; 3448 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 3449 int max; 3450 unsigned int chunk_sectors = mddev->chunk_sectors; 3451 unsigned int bio_sectors = bvm->bi_size >> 9; 3452 3453 if ((bvm->bi_rw & 1) == WRITE) 3454 return biovec->bv_len; /* always allow writes to be mergeable */ 3455 3456 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3457 chunk_sectors = mddev->new_chunk_sectors; 3458 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; 3459 if (max < 0) max = 0; 3460 if (max <= biovec->bv_len && bio_sectors == 0) 3461 return biovec->bv_len; 3462 else 3463 return max; 3464 } 3465 3466 3467 static int in_chunk_boundary(mddev_t *mddev, struct bio *bio) 3468 { 3469 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); 3470 unsigned int chunk_sectors = mddev->chunk_sectors; 3471 unsigned int bio_sectors = bio->bi_size >> 9; 3472 3473 if (mddev->new_chunk_sectors < mddev->chunk_sectors) 3474 chunk_sectors = mddev->new_chunk_sectors; 3475 return chunk_sectors >= 3476 ((sector & (chunk_sectors - 1)) + bio_sectors); 3477 } 3478 3479 /* 3480 * add bio to the retry LIFO ( in O(1) ... we are in interrupt ) 3481 * later sampled by raid5d. 3482 */ 3483 static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf) 3484 { 3485 unsigned long flags; 3486 3487 spin_lock_irqsave(&conf->device_lock, flags); 3488 3489 bi->bi_next = conf->retry_read_aligned_list; 3490 conf->retry_read_aligned_list = bi; 3491 3492 spin_unlock_irqrestore(&conf->device_lock, flags); 3493 md_wakeup_thread(conf->mddev->thread); 3494 } 3495 3496 3497 static struct bio *remove_bio_from_retry(raid5_conf_t *conf) 3498 { 3499 struct bio *bi; 3500 3501 bi = conf->retry_read_aligned; 3502 if (bi) { 3503 conf->retry_read_aligned = NULL; 3504 return bi; 3505 } 3506 bi = conf->retry_read_aligned_list; 3507 if(bi) { 3508 conf->retry_read_aligned_list = bi->bi_next; 3509 bi->bi_next = NULL; 3510 /* 3511 * this sets the active strip count to 1 and the processed 3512 * strip count to zero (upper 8 bits) 3513 */ 3514 bi->bi_phys_segments = 1; /* biased count of active stripes */ 3515 } 3516 3517 return bi; 3518 } 3519 3520 3521 /* 3522 * The "raid5_align_endio" should check if the read succeeded and if it 3523 * did, call bio_endio on the original bio (having bio_put the new bio 3524 * first). 3525 * If the read failed.. 3526 */ 3527 static void raid5_align_endio(struct bio *bi, int error) 3528 { 3529 struct bio* raid_bi = bi->bi_private; 3530 mddev_t *mddev; 3531 raid5_conf_t *conf; 3532 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); 3533 mdk_rdev_t *rdev; 3534 3535 bio_put(bi); 3536 3537 rdev = (void*)raid_bi->bi_next; 3538 raid_bi->bi_next = NULL; 3539 mddev = rdev->mddev; 3540 conf = mddev->private; 3541 3542 rdev_dec_pending(rdev, conf->mddev); 3543 3544 if (!error && uptodate) { 3545 bio_endio(raid_bi, 0); 3546 if (atomic_dec_and_test(&conf->active_aligned_reads)) 3547 wake_up(&conf->wait_for_stripe); 3548 return; 3549 } 3550 3551 3552 pr_debug("raid5_align_endio : io error...handing IO for a retry\n"); 3553 3554 add_bio_to_retry(raid_bi, conf); 3555 } 3556 3557 static int bio_fits_rdev(struct bio *bi) 3558 { 3559 struct request_queue *q = bdev_get_queue(bi->bi_bdev); 3560 3561 if ((bi->bi_size>>9) > queue_max_sectors(q)) 3562 return 0; 3563 blk_recount_segments(q, bi); 3564 if (bi->bi_phys_segments > queue_max_segments(q)) 3565 return 0; 3566 3567 if (q->merge_bvec_fn) 3568 /* it's too hard to apply the merge_bvec_fn at this stage, 3569 * just just give up 3570 */ 3571 return 0; 3572 3573 return 1; 3574 } 3575 3576 3577 static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio) 3578 { 3579 raid5_conf_t *conf = mddev->private; 3580 int dd_idx; 3581 struct bio* align_bi; 3582 mdk_rdev_t *rdev; 3583 3584 if (!in_chunk_boundary(mddev, raid_bio)) { 3585 pr_debug("chunk_aligned_read : non aligned\n"); 3586 return 0; 3587 } 3588 /* 3589 * use bio_clone_mddev to make a copy of the bio 3590 */ 3591 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev); 3592 if (!align_bi) 3593 return 0; 3594 /* 3595 * set bi_end_io to a new function, and set bi_private to the 3596 * original bio. 3597 */ 3598 align_bi->bi_end_io = raid5_align_endio; 3599 align_bi->bi_private = raid_bio; 3600 /* 3601 * compute position 3602 */ 3603 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, 3604 0, 3605 &dd_idx, NULL); 3606 3607 rcu_read_lock(); 3608 rdev = rcu_dereference(conf->disks[dd_idx].rdev); 3609 if (rdev && test_bit(In_sync, &rdev->flags)) { 3610 sector_t first_bad; 3611 int bad_sectors; 3612 3613 atomic_inc(&rdev->nr_pending); 3614 rcu_read_unlock(); 3615 raid_bio->bi_next = (void*)rdev; 3616 align_bi->bi_bdev = rdev->bdev; 3617 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID); 3618 align_bi->bi_sector += rdev->data_offset; 3619 3620 if (!bio_fits_rdev(align_bi) || 3621 is_badblock(rdev, align_bi->bi_sector, align_bi->bi_size>>9, 3622 &first_bad, &bad_sectors)) { 3623 /* too big in some way, or has a known bad block */ 3624 bio_put(align_bi); 3625 rdev_dec_pending(rdev, mddev); 3626 return 0; 3627 } 3628 3629 spin_lock_irq(&conf->device_lock); 3630 wait_event_lock_irq(conf->wait_for_stripe, 3631 conf->quiesce == 0, 3632 conf->device_lock, /* nothing */); 3633 atomic_inc(&conf->active_aligned_reads); 3634 spin_unlock_irq(&conf->device_lock); 3635 3636 generic_make_request(align_bi); 3637 return 1; 3638 } else { 3639 rcu_read_unlock(); 3640 bio_put(align_bi); 3641 return 0; 3642 } 3643 } 3644 3645 /* __get_priority_stripe - get the next stripe to process 3646 * 3647 * Full stripe writes are allowed to pass preread active stripes up until 3648 * the bypass_threshold is exceeded. In general the bypass_count 3649 * increments when the handle_list is handled before the hold_list; however, it 3650 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a 3651 * stripe with in flight i/o. The bypass_count will be reset when the 3652 * head of the hold_list has changed, i.e. the head was promoted to the 3653 * handle_list. 3654 */ 3655 static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf) 3656 { 3657 struct stripe_head *sh; 3658 3659 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n", 3660 __func__, 3661 list_empty(&conf->handle_list) ? "empty" : "busy", 3662 list_empty(&conf->hold_list) ? "empty" : "busy", 3663 atomic_read(&conf->pending_full_writes), conf->bypass_count); 3664 3665 if (!list_empty(&conf->handle_list)) { 3666 sh = list_entry(conf->handle_list.next, typeof(*sh), lru); 3667 3668 if (list_empty(&conf->hold_list)) 3669 conf->bypass_count = 0; 3670 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) { 3671 if (conf->hold_list.next == conf->last_hold) 3672 conf->bypass_count++; 3673 else { 3674 conf->last_hold = conf->hold_list.next; 3675 conf->bypass_count -= conf->bypass_threshold; 3676 if (conf->bypass_count < 0) 3677 conf->bypass_count = 0; 3678 } 3679 } 3680 } else if (!list_empty(&conf->hold_list) && 3681 ((conf->bypass_threshold && 3682 conf->bypass_count > conf->bypass_threshold) || 3683 atomic_read(&conf->pending_full_writes) == 0)) { 3684 sh = list_entry(conf->hold_list.next, 3685 typeof(*sh), lru); 3686 conf->bypass_count -= conf->bypass_threshold; 3687 if (conf->bypass_count < 0) 3688 conf->bypass_count = 0; 3689 } else 3690 return NULL; 3691 3692 list_del_init(&sh->lru); 3693 atomic_inc(&sh->count); 3694 BUG_ON(atomic_read(&sh->count) != 1); 3695 return sh; 3696 } 3697 3698 static int make_request(mddev_t *mddev, struct bio * bi) 3699 { 3700 raid5_conf_t *conf = mddev->private; 3701 int dd_idx; 3702 sector_t new_sector; 3703 sector_t logical_sector, last_sector; 3704 struct stripe_head *sh; 3705 const int rw = bio_data_dir(bi); 3706 int remaining; 3707 int plugged; 3708 3709 if (unlikely(bi->bi_rw & REQ_FLUSH)) { 3710 md_flush_request(mddev, bi); 3711 return 0; 3712 } 3713 3714 md_write_start(mddev, bi); 3715 3716 if (rw == READ && 3717 mddev->reshape_position == MaxSector && 3718 chunk_aligned_read(mddev,bi)) 3719 return 0; 3720 3721 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 3722 last_sector = bi->bi_sector + (bi->bi_size>>9); 3723 bi->bi_next = NULL; 3724 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ 3725 3726 plugged = mddev_check_plugged(mddev); 3727 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 3728 DEFINE_WAIT(w); 3729 int disks, data_disks; 3730 int previous; 3731 3732 retry: 3733 previous = 0; 3734 disks = conf->raid_disks; 3735 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 3736 if (unlikely(conf->reshape_progress != MaxSector)) { 3737 /* spinlock is needed as reshape_progress may be 3738 * 64bit on a 32bit platform, and so it might be 3739 * possible to see a half-updated value 3740 * Of course reshape_progress could change after 3741 * the lock is dropped, so once we get a reference 3742 * to the stripe that we think it is, we will have 3743 * to check again. 3744 */ 3745 spin_lock_irq(&conf->device_lock); 3746 if (mddev->delta_disks < 0 3747 ? logical_sector < conf->reshape_progress 3748 : logical_sector >= conf->reshape_progress) { 3749 disks = conf->previous_raid_disks; 3750 previous = 1; 3751 } else { 3752 if (mddev->delta_disks < 0 3753 ? logical_sector < conf->reshape_safe 3754 : logical_sector >= conf->reshape_safe) { 3755 spin_unlock_irq(&conf->device_lock); 3756 schedule(); 3757 goto retry; 3758 } 3759 } 3760 spin_unlock_irq(&conf->device_lock); 3761 } 3762 data_disks = disks - conf->max_degraded; 3763 3764 new_sector = raid5_compute_sector(conf, logical_sector, 3765 previous, 3766 &dd_idx, NULL); 3767 pr_debug("raid456: make_request, sector %llu logical %llu\n", 3768 (unsigned long long)new_sector, 3769 (unsigned long long)logical_sector); 3770 3771 sh = get_active_stripe(conf, new_sector, previous, 3772 (bi->bi_rw&RWA_MASK), 0); 3773 if (sh) { 3774 if (unlikely(previous)) { 3775 /* expansion might have moved on while waiting for a 3776 * stripe, so we must do the range check again. 3777 * Expansion could still move past after this 3778 * test, but as we are holding a reference to 3779 * 'sh', we know that if that happens, 3780 * STRIPE_EXPANDING will get set and the expansion 3781 * won't proceed until we finish with the stripe. 3782 */ 3783 int must_retry = 0; 3784 spin_lock_irq(&conf->device_lock); 3785 if (mddev->delta_disks < 0 3786 ? logical_sector >= conf->reshape_progress 3787 : logical_sector < conf->reshape_progress) 3788 /* mismatch, need to try again */ 3789 must_retry = 1; 3790 spin_unlock_irq(&conf->device_lock); 3791 if (must_retry) { 3792 release_stripe(sh); 3793 schedule(); 3794 goto retry; 3795 } 3796 } 3797 3798 if (rw == WRITE && 3799 logical_sector >= mddev->suspend_lo && 3800 logical_sector < mddev->suspend_hi) { 3801 release_stripe(sh); 3802 /* As the suspend_* range is controlled by 3803 * userspace, we want an interruptible 3804 * wait. 3805 */ 3806 flush_signals(current); 3807 prepare_to_wait(&conf->wait_for_overlap, 3808 &w, TASK_INTERRUPTIBLE); 3809 if (logical_sector >= mddev->suspend_lo && 3810 logical_sector < mddev->suspend_hi) 3811 schedule(); 3812 goto retry; 3813 } 3814 3815 if (test_bit(STRIPE_EXPANDING, &sh->state) || 3816 !add_stripe_bio(sh, bi, dd_idx, rw)) { 3817 /* Stripe is busy expanding or 3818 * add failed due to overlap. Flush everything 3819 * and wait a while 3820 */ 3821 md_wakeup_thread(mddev->thread); 3822 release_stripe(sh); 3823 schedule(); 3824 goto retry; 3825 } 3826 finish_wait(&conf->wait_for_overlap, &w); 3827 set_bit(STRIPE_HANDLE, &sh->state); 3828 clear_bit(STRIPE_DELAYED, &sh->state); 3829 if ((bi->bi_rw & REQ_SYNC) && 3830 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) 3831 atomic_inc(&conf->preread_active_stripes); 3832 release_stripe(sh); 3833 } else { 3834 /* cannot get stripe for read-ahead, just give-up */ 3835 clear_bit(BIO_UPTODATE, &bi->bi_flags); 3836 finish_wait(&conf->wait_for_overlap, &w); 3837 break; 3838 } 3839 3840 } 3841 if (!plugged) 3842 md_wakeup_thread(mddev->thread); 3843 3844 spin_lock_irq(&conf->device_lock); 3845 remaining = raid5_dec_bi_phys_segments(bi); 3846 spin_unlock_irq(&conf->device_lock); 3847 if (remaining == 0) { 3848 3849 if ( rw == WRITE ) 3850 md_write_end(mddev); 3851 3852 bio_endio(bi, 0); 3853 } 3854 3855 return 0; 3856 } 3857 3858 static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks); 3859 3860 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped) 3861 { 3862 /* reshaping is quite different to recovery/resync so it is 3863 * handled quite separately ... here. 3864 * 3865 * On each call to sync_request, we gather one chunk worth of 3866 * destination stripes and flag them as expanding. 3867 * Then we find all the source stripes and request reads. 3868 * As the reads complete, handle_stripe will copy the data 3869 * into the destination stripe and release that stripe. 3870 */ 3871 raid5_conf_t *conf = mddev->private; 3872 struct stripe_head *sh; 3873 sector_t first_sector, last_sector; 3874 int raid_disks = conf->previous_raid_disks; 3875 int data_disks = raid_disks - conf->max_degraded; 3876 int new_data_disks = conf->raid_disks - conf->max_degraded; 3877 int i; 3878 int dd_idx; 3879 sector_t writepos, readpos, safepos; 3880 sector_t stripe_addr; 3881 int reshape_sectors; 3882 struct list_head stripes; 3883 3884 if (sector_nr == 0) { 3885 /* If restarting in the middle, skip the initial sectors */ 3886 if (mddev->delta_disks < 0 && 3887 conf->reshape_progress < raid5_size(mddev, 0, 0)) { 3888 sector_nr = raid5_size(mddev, 0, 0) 3889 - conf->reshape_progress; 3890 } else if (mddev->delta_disks >= 0 && 3891 conf->reshape_progress > 0) 3892 sector_nr = conf->reshape_progress; 3893 sector_div(sector_nr, new_data_disks); 3894 if (sector_nr) { 3895 mddev->curr_resync_completed = sector_nr; 3896 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3897 *skipped = 1; 3898 return sector_nr; 3899 } 3900 } 3901 3902 /* We need to process a full chunk at a time. 3903 * If old and new chunk sizes differ, we need to process the 3904 * largest of these 3905 */ 3906 if (mddev->new_chunk_sectors > mddev->chunk_sectors) 3907 reshape_sectors = mddev->new_chunk_sectors; 3908 else 3909 reshape_sectors = mddev->chunk_sectors; 3910 3911 /* we update the metadata when there is more than 3Meg 3912 * in the block range (that is rather arbitrary, should 3913 * probably be time based) or when the data about to be 3914 * copied would over-write the source of the data at 3915 * the front of the range. 3916 * i.e. one new_stripe along from reshape_progress new_maps 3917 * to after where reshape_safe old_maps to 3918 */ 3919 writepos = conf->reshape_progress; 3920 sector_div(writepos, new_data_disks); 3921 readpos = conf->reshape_progress; 3922 sector_div(readpos, data_disks); 3923 safepos = conf->reshape_safe; 3924 sector_div(safepos, data_disks); 3925 if (mddev->delta_disks < 0) { 3926 writepos -= min_t(sector_t, reshape_sectors, writepos); 3927 readpos += reshape_sectors; 3928 safepos += reshape_sectors; 3929 } else { 3930 writepos += reshape_sectors; 3931 readpos -= min_t(sector_t, reshape_sectors, readpos); 3932 safepos -= min_t(sector_t, reshape_sectors, safepos); 3933 } 3934 3935 /* 'writepos' is the most advanced device address we might write. 3936 * 'readpos' is the least advanced device address we might read. 3937 * 'safepos' is the least address recorded in the metadata as having 3938 * been reshaped. 3939 * If 'readpos' is behind 'writepos', then there is no way that we can 3940 * ensure safety in the face of a crash - that must be done by userspace 3941 * making a backup of the data. So in that case there is no particular 3942 * rush to update metadata. 3943 * Otherwise if 'safepos' is behind 'writepos', then we really need to 3944 * update the metadata to advance 'safepos' to match 'readpos' so that 3945 * we can be safe in the event of a crash. 3946 * So we insist on updating metadata if safepos is behind writepos and 3947 * readpos is beyond writepos. 3948 * In any case, update the metadata every 10 seconds. 3949 * Maybe that number should be configurable, but I'm not sure it is 3950 * worth it.... maybe it could be a multiple of safemode_delay??? 3951 */ 3952 if ((mddev->delta_disks < 0 3953 ? (safepos > writepos && readpos < writepos) 3954 : (safepos < writepos && readpos > writepos)) || 3955 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { 3956 /* Cannot proceed until we've updated the superblock... */ 3957 wait_event(conf->wait_for_overlap, 3958 atomic_read(&conf->reshape_stripes)==0); 3959 mddev->reshape_position = conf->reshape_progress; 3960 mddev->curr_resync_completed = sector_nr; 3961 conf->reshape_checkpoint = jiffies; 3962 set_bit(MD_CHANGE_DEVS, &mddev->flags); 3963 md_wakeup_thread(mddev->thread); 3964 wait_event(mddev->sb_wait, mddev->flags == 0 || 3965 kthread_should_stop()); 3966 spin_lock_irq(&conf->device_lock); 3967 conf->reshape_safe = mddev->reshape_position; 3968 spin_unlock_irq(&conf->device_lock); 3969 wake_up(&conf->wait_for_overlap); 3970 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 3971 } 3972 3973 if (mddev->delta_disks < 0) { 3974 BUG_ON(conf->reshape_progress == 0); 3975 stripe_addr = writepos; 3976 BUG_ON((mddev->dev_sectors & 3977 ~((sector_t)reshape_sectors - 1)) 3978 - reshape_sectors - stripe_addr 3979 != sector_nr); 3980 } else { 3981 BUG_ON(writepos != sector_nr + reshape_sectors); 3982 stripe_addr = sector_nr; 3983 } 3984 INIT_LIST_HEAD(&stripes); 3985 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { 3986 int j; 3987 int skipped_disk = 0; 3988 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1); 3989 set_bit(STRIPE_EXPANDING, &sh->state); 3990 atomic_inc(&conf->reshape_stripes); 3991 /* If any of this stripe is beyond the end of the old 3992 * array, then we need to zero those blocks 3993 */ 3994 for (j=sh->disks; j--;) { 3995 sector_t s; 3996 if (j == sh->pd_idx) 3997 continue; 3998 if (conf->level == 6 && 3999 j == sh->qd_idx) 4000 continue; 4001 s = compute_blocknr(sh, j, 0); 4002 if (s < raid5_size(mddev, 0, 0)) { 4003 skipped_disk = 1; 4004 continue; 4005 } 4006 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE); 4007 set_bit(R5_Expanded, &sh->dev[j].flags); 4008 set_bit(R5_UPTODATE, &sh->dev[j].flags); 4009 } 4010 if (!skipped_disk) { 4011 set_bit(STRIPE_EXPAND_READY, &sh->state); 4012 set_bit(STRIPE_HANDLE, &sh->state); 4013 } 4014 list_add(&sh->lru, &stripes); 4015 } 4016 spin_lock_irq(&conf->device_lock); 4017 if (mddev->delta_disks < 0) 4018 conf->reshape_progress -= reshape_sectors * new_data_disks; 4019 else 4020 conf->reshape_progress += reshape_sectors * new_data_disks; 4021 spin_unlock_irq(&conf->device_lock); 4022 /* Ok, those stripe are ready. We can start scheduling 4023 * reads on the source stripes. 4024 * The source stripes are determined by mapping the first and last 4025 * block on the destination stripes. 4026 */ 4027 first_sector = 4028 raid5_compute_sector(conf, stripe_addr*(new_data_disks), 4029 1, &dd_idx, NULL); 4030 last_sector = 4031 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors) 4032 * new_data_disks - 1), 4033 1, &dd_idx, NULL); 4034 if (last_sector >= mddev->dev_sectors) 4035 last_sector = mddev->dev_sectors - 1; 4036 while (first_sector <= last_sector) { 4037 sh = get_active_stripe(conf, first_sector, 1, 0, 1); 4038 set_bit(STRIPE_EXPAND_SOURCE, &sh->state); 4039 set_bit(STRIPE_HANDLE, &sh->state); 4040 release_stripe(sh); 4041 first_sector += STRIPE_SECTORS; 4042 } 4043 /* Now that the sources are clearly marked, we can release 4044 * the destination stripes 4045 */ 4046 while (!list_empty(&stripes)) { 4047 sh = list_entry(stripes.next, struct stripe_head, lru); 4048 list_del_init(&sh->lru); 4049 release_stripe(sh); 4050 } 4051 /* If this takes us to the resync_max point where we have to pause, 4052 * then we need to write out the superblock. 4053 */ 4054 sector_nr += reshape_sectors; 4055 if ((sector_nr - mddev->curr_resync_completed) * 2 4056 >= mddev->resync_max - mddev->curr_resync_completed) { 4057 /* Cannot proceed until we've updated the superblock... */ 4058 wait_event(conf->wait_for_overlap, 4059 atomic_read(&conf->reshape_stripes) == 0); 4060 mddev->reshape_position = conf->reshape_progress; 4061 mddev->curr_resync_completed = sector_nr; 4062 conf->reshape_checkpoint = jiffies; 4063 set_bit(MD_CHANGE_DEVS, &mddev->flags); 4064 md_wakeup_thread(mddev->thread); 4065 wait_event(mddev->sb_wait, 4066 !test_bit(MD_CHANGE_DEVS, &mddev->flags) 4067 || kthread_should_stop()); 4068 spin_lock_irq(&conf->device_lock); 4069 conf->reshape_safe = mddev->reshape_position; 4070 spin_unlock_irq(&conf->device_lock); 4071 wake_up(&conf->wait_for_overlap); 4072 sysfs_notify(&mddev->kobj, NULL, "sync_completed"); 4073 } 4074 return reshape_sectors; 4075 } 4076 4077 /* FIXME go_faster isn't used */ 4078 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) 4079 { 4080 raid5_conf_t *conf = mddev->private; 4081 struct stripe_head *sh; 4082 sector_t max_sector = mddev->dev_sectors; 4083 sector_t sync_blocks; 4084 int still_degraded = 0; 4085 int i; 4086 4087 if (sector_nr >= max_sector) { 4088 /* just being told to finish up .. nothing much to do */ 4089 4090 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { 4091 end_reshape(conf); 4092 return 0; 4093 } 4094 4095 if (mddev->curr_resync < max_sector) /* aborted */ 4096 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 4097 &sync_blocks, 1); 4098 else /* completed sync */ 4099 conf->fullsync = 0; 4100 bitmap_close_sync(mddev->bitmap); 4101 4102 return 0; 4103 } 4104 4105 /* Allow raid5_quiesce to complete */ 4106 wait_event(conf->wait_for_overlap, conf->quiesce != 2); 4107 4108 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) 4109 return reshape_request(mddev, sector_nr, skipped); 4110 4111 /* No need to check resync_max as we never do more than one 4112 * stripe, and as resync_max will always be on a chunk boundary, 4113 * if the check in md_do_sync didn't fire, there is no chance 4114 * of overstepping resync_max here 4115 */ 4116 4117 /* if there is too many failed drives and we are trying 4118 * to resync, then assert that we are finished, because there is 4119 * nothing we can do. 4120 */ 4121 if (mddev->degraded >= conf->max_degraded && 4122 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 4123 sector_t rv = mddev->dev_sectors - sector_nr; 4124 *skipped = 1; 4125 return rv; 4126 } 4127 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 4128 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 4129 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) { 4130 /* we can skip this block, and probably more */ 4131 sync_blocks /= STRIPE_SECTORS; 4132 *skipped = 1; 4133 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */ 4134 } 4135 4136 4137 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 4138 4139 sh = get_active_stripe(conf, sector_nr, 0, 1, 0); 4140 if (sh == NULL) { 4141 sh = get_active_stripe(conf, sector_nr, 0, 0, 0); 4142 /* make sure we don't swamp the stripe cache if someone else 4143 * is trying to get access 4144 */ 4145 schedule_timeout_uninterruptible(1); 4146 } 4147 /* Need to check if array will still be degraded after recovery/resync 4148 * We don't need to check the 'failed' flag as when that gets set, 4149 * recovery aborts. 4150 */ 4151 for (i = 0; i < conf->raid_disks; i++) 4152 if (conf->disks[i].rdev == NULL) 4153 still_degraded = 1; 4154 4155 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); 4156 4157 set_bit(STRIPE_SYNC_REQUESTED, &sh->state); 4158 4159 handle_stripe(sh); 4160 release_stripe(sh); 4161 4162 return STRIPE_SECTORS; 4163 } 4164 4165 static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) 4166 { 4167 /* We may not be able to submit a whole bio at once as there 4168 * may not be enough stripe_heads available. 4169 * We cannot pre-allocate enough stripe_heads as we may need 4170 * more than exist in the cache (if we allow ever large chunks). 4171 * So we do one stripe head at a time and record in 4172 * ->bi_hw_segments how many have been done. 4173 * 4174 * We *know* that this entire raid_bio is in one chunk, so 4175 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. 4176 */ 4177 struct stripe_head *sh; 4178 int dd_idx; 4179 sector_t sector, logical_sector, last_sector; 4180 int scnt = 0; 4181 int remaining; 4182 int handled = 0; 4183 4184 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); 4185 sector = raid5_compute_sector(conf, logical_sector, 4186 0, &dd_idx, NULL); 4187 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); 4188 4189 for (; logical_sector < last_sector; 4190 logical_sector += STRIPE_SECTORS, 4191 sector += STRIPE_SECTORS, 4192 scnt++) { 4193 4194 if (scnt < raid5_bi_hw_segments(raid_bio)) 4195 /* already done this stripe */ 4196 continue; 4197 4198 sh = get_active_stripe(conf, sector, 0, 1, 0); 4199 4200 if (!sh) { 4201 /* failed to get a stripe - must wait */ 4202 raid5_set_bi_hw_segments(raid_bio, scnt); 4203 conf->retry_read_aligned = raid_bio; 4204 return handled; 4205 } 4206 4207 set_bit(R5_ReadError, &sh->dev[dd_idx].flags); 4208 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { 4209 release_stripe(sh); 4210 raid5_set_bi_hw_segments(raid_bio, scnt); 4211 conf->retry_read_aligned = raid_bio; 4212 return handled; 4213 } 4214 4215 handle_stripe(sh); 4216 release_stripe(sh); 4217 handled++; 4218 } 4219 spin_lock_irq(&conf->device_lock); 4220 remaining = raid5_dec_bi_phys_segments(raid_bio); 4221 spin_unlock_irq(&conf->device_lock); 4222 if (remaining == 0) 4223 bio_endio(raid_bio, 0); 4224 if (atomic_dec_and_test(&conf->active_aligned_reads)) 4225 wake_up(&conf->wait_for_stripe); 4226 return handled; 4227 } 4228 4229 4230 /* 4231 * This is our raid5 kernel thread. 4232 * 4233 * We scan the hash table for stripes which can be handled now. 4234 * During the scan, completed stripes are saved for us by the interrupt 4235 * handler, so that they will not have to wait for our next wakeup. 4236 */ 4237 static void raid5d(mddev_t *mddev) 4238 { 4239 struct stripe_head *sh; 4240 raid5_conf_t *conf = mddev->private; 4241 int handled; 4242 struct blk_plug plug; 4243 4244 pr_debug("+++ raid5d active\n"); 4245 4246 md_check_recovery(mddev); 4247 4248 blk_start_plug(&plug); 4249 handled = 0; 4250 spin_lock_irq(&conf->device_lock); 4251 while (1) { 4252 struct bio *bio; 4253 4254 if (atomic_read(&mddev->plug_cnt) == 0 && 4255 !list_empty(&conf->bitmap_list)) { 4256 /* Now is a good time to flush some bitmap updates */ 4257 conf->seq_flush++; 4258 spin_unlock_irq(&conf->device_lock); 4259 bitmap_unplug(mddev->bitmap); 4260 spin_lock_irq(&conf->device_lock); 4261 conf->seq_write = conf->seq_flush; 4262 activate_bit_delay(conf); 4263 } 4264 if (atomic_read(&mddev->plug_cnt) == 0) 4265 raid5_activate_delayed(conf); 4266 4267 while ((bio = remove_bio_from_retry(conf))) { 4268 int ok; 4269 spin_unlock_irq(&conf->device_lock); 4270 ok = retry_aligned_read(conf, bio); 4271 spin_lock_irq(&conf->device_lock); 4272 if (!ok) 4273 break; 4274 handled++; 4275 } 4276 4277 sh = __get_priority_stripe(conf); 4278 4279 if (!sh) 4280 break; 4281 spin_unlock_irq(&conf->device_lock); 4282 4283 handled++; 4284 handle_stripe(sh); 4285 release_stripe(sh); 4286 cond_resched(); 4287 4288 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) 4289 md_check_recovery(mddev); 4290 4291 spin_lock_irq(&conf->device_lock); 4292 } 4293 pr_debug("%d stripes handled\n", handled); 4294 4295 spin_unlock_irq(&conf->device_lock); 4296 4297 async_tx_issue_pending_all(); 4298 blk_finish_plug(&plug); 4299 4300 pr_debug("--- raid5d inactive\n"); 4301 } 4302 4303 static ssize_t 4304 raid5_show_stripe_cache_size(mddev_t *mddev, char *page) 4305 { 4306 raid5_conf_t *conf = mddev->private; 4307 if (conf) 4308 return sprintf(page, "%d\n", conf->max_nr_stripes); 4309 else 4310 return 0; 4311 } 4312 4313 int 4314 raid5_set_cache_size(mddev_t *mddev, int size) 4315 { 4316 raid5_conf_t *conf = mddev->private; 4317 int err; 4318 4319 if (size <= 16 || size > 32768) 4320 return -EINVAL; 4321 while (size < conf->max_nr_stripes) { 4322 if (drop_one_stripe(conf)) 4323 conf->max_nr_stripes--; 4324 else 4325 break; 4326 } 4327 err = md_allow_write(mddev); 4328 if (err) 4329 return err; 4330 while (size > conf->max_nr_stripes) { 4331 if (grow_one_stripe(conf)) 4332 conf->max_nr_stripes++; 4333 else break; 4334 } 4335 return 0; 4336 } 4337 EXPORT_SYMBOL(raid5_set_cache_size); 4338 4339 static ssize_t 4340 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) 4341 { 4342 raid5_conf_t *conf = mddev->private; 4343 unsigned long new; 4344 int err; 4345 4346 if (len >= PAGE_SIZE) 4347 return -EINVAL; 4348 if (!conf) 4349 return -ENODEV; 4350 4351 if (strict_strtoul(page, 10, &new)) 4352 return -EINVAL; 4353 err = raid5_set_cache_size(mddev, new); 4354 if (err) 4355 return err; 4356 return len; 4357 } 4358 4359 static struct md_sysfs_entry 4360 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, 4361 raid5_show_stripe_cache_size, 4362 raid5_store_stripe_cache_size); 4363 4364 static ssize_t 4365 raid5_show_preread_threshold(mddev_t *mddev, char *page) 4366 { 4367 raid5_conf_t *conf = mddev->private; 4368 if (conf) 4369 return sprintf(page, "%d\n", conf->bypass_threshold); 4370 else 4371 return 0; 4372 } 4373 4374 static ssize_t 4375 raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len) 4376 { 4377 raid5_conf_t *conf = mddev->private; 4378 unsigned long new; 4379 if (len >= PAGE_SIZE) 4380 return -EINVAL; 4381 if (!conf) 4382 return -ENODEV; 4383 4384 if (strict_strtoul(page, 10, &new)) 4385 return -EINVAL; 4386 if (new > conf->max_nr_stripes) 4387 return -EINVAL; 4388 conf->bypass_threshold = new; 4389 return len; 4390 } 4391 4392 static struct md_sysfs_entry 4393 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold, 4394 S_IRUGO | S_IWUSR, 4395 raid5_show_preread_threshold, 4396 raid5_store_preread_threshold); 4397 4398 static ssize_t 4399 stripe_cache_active_show(mddev_t *mddev, char *page) 4400 { 4401 raid5_conf_t *conf = mddev->private; 4402 if (conf) 4403 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); 4404 else 4405 return 0; 4406 } 4407 4408 static struct md_sysfs_entry 4409 raid5_stripecache_active = __ATTR_RO(stripe_cache_active); 4410 4411 static struct attribute *raid5_attrs[] = { 4412 &raid5_stripecache_size.attr, 4413 &raid5_stripecache_active.attr, 4414 &raid5_preread_bypass_threshold.attr, 4415 NULL, 4416 }; 4417 static struct attribute_group raid5_attrs_group = { 4418 .name = NULL, 4419 .attrs = raid5_attrs, 4420 }; 4421 4422 static sector_t 4423 raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks) 4424 { 4425 raid5_conf_t *conf = mddev->private; 4426 4427 if (!sectors) 4428 sectors = mddev->dev_sectors; 4429 if (!raid_disks) 4430 /* size is defined by the smallest of previous and new size */ 4431 raid_disks = min(conf->raid_disks, conf->previous_raid_disks); 4432 4433 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 4434 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); 4435 return sectors * (raid_disks - conf->max_degraded); 4436 } 4437 4438 static void raid5_free_percpu(raid5_conf_t *conf) 4439 { 4440 struct raid5_percpu *percpu; 4441 unsigned long cpu; 4442 4443 if (!conf->percpu) 4444 return; 4445 4446 get_online_cpus(); 4447 for_each_possible_cpu(cpu) { 4448 percpu = per_cpu_ptr(conf->percpu, cpu); 4449 safe_put_page(percpu->spare_page); 4450 kfree(percpu->scribble); 4451 } 4452 #ifdef CONFIG_HOTPLUG_CPU 4453 unregister_cpu_notifier(&conf->cpu_notify); 4454 #endif 4455 put_online_cpus(); 4456 4457 free_percpu(conf->percpu); 4458 } 4459 4460 static void free_conf(raid5_conf_t *conf) 4461 { 4462 shrink_stripes(conf); 4463 raid5_free_percpu(conf); 4464 kfree(conf->disks); 4465 kfree(conf->stripe_hashtbl); 4466 kfree(conf); 4467 } 4468 4469 #ifdef CONFIG_HOTPLUG_CPU 4470 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, 4471 void *hcpu) 4472 { 4473 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify); 4474 long cpu = (long)hcpu; 4475 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); 4476 4477 switch (action) { 4478 case CPU_UP_PREPARE: 4479 case CPU_UP_PREPARE_FROZEN: 4480 if (conf->level == 6 && !percpu->spare_page) 4481 percpu->spare_page = alloc_page(GFP_KERNEL); 4482 if (!percpu->scribble) 4483 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4484 4485 if (!percpu->scribble || 4486 (conf->level == 6 && !percpu->spare_page)) { 4487 safe_put_page(percpu->spare_page); 4488 kfree(percpu->scribble); 4489 pr_err("%s: failed memory allocation for cpu%ld\n", 4490 __func__, cpu); 4491 return notifier_from_errno(-ENOMEM); 4492 } 4493 break; 4494 case CPU_DEAD: 4495 case CPU_DEAD_FROZEN: 4496 safe_put_page(percpu->spare_page); 4497 kfree(percpu->scribble); 4498 percpu->spare_page = NULL; 4499 percpu->scribble = NULL; 4500 break; 4501 default: 4502 break; 4503 } 4504 return NOTIFY_OK; 4505 } 4506 #endif 4507 4508 static int raid5_alloc_percpu(raid5_conf_t *conf) 4509 { 4510 unsigned long cpu; 4511 struct page *spare_page; 4512 struct raid5_percpu __percpu *allcpus; 4513 void *scribble; 4514 int err; 4515 4516 allcpus = alloc_percpu(struct raid5_percpu); 4517 if (!allcpus) 4518 return -ENOMEM; 4519 conf->percpu = allcpus; 4520 4521 get_online_cpus(); 4522 err = 0; 4523 for_each_present_cpu(cpu) { 4524 if (conf->level == 6) { 4525 spare_page = alloc_page(GFP_KERNEL); 4526 if (!spare_page) { 4527 err = -ENOMEM; 4528 break; 4529 } 4530 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page; 4531 } 4532 scribble = kmalloc(conf->scribble_len, GFP_KERNEL); 4533 if (!scribble) { 4534 err = -ENOMEM; 4535 break; 4536 } 4537 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; 4538 } 4539 #ifdef CONFIG_HOTPLUG_CPU 4540 conf->cpu_notify.notifier_call = raid456_cpu_notify; 4541 conf->cpu_notify.priority = 0; 4542 if (err == 0) 4543 err = register_cpu_notifier(&conf->cpu_notify); 4544 #endif 4545 put_online_cpus(); 4546 4547 return err; 4548 } 4549 4550 static raid5_conf_t *setup_conf(mddev_t *mddev) 4551 { 4552 raid5_conf_t *conf; 4553 int raid_disk, memory, max_disks; 4554 mdk_rdev_t *rdev; 4555 struct disk_info *disk; 4556 4557 if (mddev->new_level != 5 4558 && mddev->new_level != 4 4559 && mddev->new_level != 6) { 4560 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n", 4561 mdname(mddev), mddev->new_level); 4562 return ERR_PTR(-EIO); 4563 } 4564 if ((mddev->new_level == 5 4565 && !algorithm_valid_raid5(mddev->new_layout)) || 4566 (mddev->new_level == 6 4567 && !algorithm_valid_raid6(mddev->new_layout))) { 4568 printk(KERN_ERR "md/raid:%s: layout %d not supported\n", 4569 mdname(mddev), mddev->new_layout); 4570 return ERR_PTR(-EIO); 4571 } 4572 if (mddev->new_level == 6 && mddev->raid_disks < 4) { 4573 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n", 4574 mdname(mddev), mddev->raid_disks); 4575 return ERR_PTR(-EINVAL); 4576 } 4577 4578 if (!mddev->new_chunk_sectors || 4579 (mddev->new_chunk_sectors << 9) % PAGE_SIZE || 4580 !is_power_of_2(mddev->new_chunk_sectors)) { 4581 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n", 4582 mdname(mddev), mddev->new_chunk_sectors << 9); 4583 return ERR_PTR(-EINVAL); 4584 } 4585 4586 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL); 4587 if (conf == NULL) 4588 goto abort; 4589 spin_lock_init(&conf->device_lock); 4590 init_waitqueue_head(&conf->wait_for_stripe); 4591 init_waitqueue_head(&conf->wait_for_overlap); 4592 INIT_LIST_HEAD(&conf->handle_list); 4593 INIT_LIST_HEAD(&conf->hold_list); 4594 INIT_LIST_HEAD(&conf->delayed_list); 4595 INIT_LIST_HEAD(&conf->bitmap_list); 4596 INIT_LIST_HEAD(&conf->inactive_list); 4597 atomic_set(&conf->active_stripes, 0); 4598 atomic_set(&conf->preread_active_stripes, 0); 4599 atomic_set(&conf->active_aligned_reads, 0); 4600 conf->bypass_threshold = BYPASS_THRESHOLD; 4601 4602 conf->raid_disks = mddev->raid_disks; 4603 if (mddev->reshape_position == MaxSector) 4604 conf->previous_raid_disks = mddev->raid_disks; 4605 else 4606 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks; 4607 max_disks = max(conf->raid_disks, conf->previous_raid_disks); 4608 conf->scribble_len = scribble_len(max_disks); 4609 4610 conf->disks = kzalloc(max_disks * sizeof(struct disk_info), 4611 GFP_KERNEL); 4612 if (!conf->disks) 4613 goto abort; 4614 4615 conf->mddev = mddev; 4616 4617 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 4618 goto abort; 4619 4620 conf->level = mddev->new_level; 4621 if (raid5_alloc_percpu(conf) != 0) 4622 goto abort; 4623 4624 pr_debug("raid456: run(%s) called.\n", mdname(mddev)); 4625 4626 list_for_each_entry(rdev, &mddev->disks, same_set) { 4627 raid_disk = rdev->raid_disk; 4628 if (raid_disk >= max_disks 4629 || raid_disk < 0) 4630 continue; 4631 disk = conf->disks + raid_disk; 4632 4633 disk->rdev = rdev; 4634 4635 if (test_bit(In_sync, &rdev->flags)) { 4636 char b[BDEVNAME_SIZE]; 4637 printk(KERN_INFO "md/raid:%s: device %s operational as raid" 4638 " disk %d\n", 4639 mdname(mddev), bdevname(rdev->bdev, b), raid_disk); 4640 } else if (rdev->saved_raid_disk != raid_disk) 4641 /* Cannot rely on bitmap to complete recovery */ 4642 conf->fullsync = 1; 4643 } 4644 4645 conf->chunk_sectors = mddev->new_chunk_sectors; 4646 conf->level = mddev->new_level; 4647 if (conf->level == 6) 4648 conf->max_degraded = 2; 4649 else 4650 conf->max_degraded = 1; 4651 conf->algorithm = mddev->new_layout; 4652 conf->max_nr_stripes = NR_STRIPES; 4653 conf->reshape_progress = mddev->reshape_position; 4654 if (conf->reshape_progress != MaxSector) { 4655 conf->prev_chunk_sectors = mddev->chunk_sectors; 4656 conf->prev_algo = mddev->layout; 4657 } 4658 4659 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 4660 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; 4661 if (grow_stripes(conf, conf->max_nr_stripes)) { 4662 printk(KERN_ERR 4663 "md/raid:%s: couldn't allocate %dkB for buffers\n", 4664 mdname(mddev), memory); 4665 goto abort; 4666 } else 4667 printk(KERN_INFO "md/raid:%s: allocated %dkB\n", 4668 mdname(mddev), memory); 4669 4670 conf->thread = md_register_thread(raid5d, mddev, NULL); 4671 if (!conf->thread) { 4672 printk(KERN_ERR 4673 "md/raid:%s: couldn't allocate thread.\n", 4674 mdname(mddev)); 4675 goto abort; 4676 } 4677 4678 return conf; 4679 4680 abort: 4681 if (conf) { 4682 free_conf(conf); 4683 return ERR_PTR(-EIO); 4684 } else 4685 return ERR_PTR(-ENOMEM); 4686 } 4687 4688 4689 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded) 4690 { 4691 switch (algo) { 4692 case ALGORITHM_PARITY_0: 4693 if (raid_disk < max_degraded) 4694 return 1; 4695 break; 4696 case ALGORITHM_PARITY_N: 4697 if (raid_disk >= raid_disks - max_degraded) 4698 return 1; 4699 break; 4700 case ALGORITHM_PARITY_0_6: 4701 if (raid_disk == 0 || 4702 raid_disk == raid_disks - 1) 4703 return 1; 4704 break; 4705 case ALGORITHM_LEFT_ASYMMETRIC_6: 4706 case ALGORITHM_RIGHT_ASYMMETRIC_6: 4707 case ALGORITHM_LEFT_SYMMETRIC_6: 4708 case ALGORITHM_RIGHT_SYMMETRIC_6: 4709 if (raid_disk == raid_disks - 1) 4710 return 1; 4711 } 4712 return 0; 4713 } 4714 4715 static int run(mddev_t *mddev) 4716 { 4717 raid5_conf_t *conf; 4718 int working_disks = 0; 4719 int dirty_parity_disks = 0; 4720 mdk_rdev_t *rdev; 4721 sector_t reshape_offset = 0; 4722 4723 if (mddev->recovery_cp != MaxSector) 4724 printk(KERN_NOTICE "md/raid:%s: not clean" 4725 " -- starting background reconstruction\n", 4726 mdname(mddev)); 4727 if (mddev->reshape_position != MaxSector) { 4728 /* Check that we can continue the reshape. 4729 * Currently only disks can change, it must 4730 * increase, and we must be past the point where 4731 * a stripe over-writes itself 4732 */ 4733 sector_t here_new, here_old; 4734 int old_disks; 4735 int max_degraded = (mddev->level == 6 ? 2 : 1); 4736 4737 if (mddev->new_level != mddev->level) { 4738 printk(KERN_ERR "md/raid:%s: unsupported reshape " 4739 "required - aborting.\n", 4740 mdname(mddev)); 4741 return -EINVAL; 4742 } 4743 old_disks = mddev->raid_disks - mddev->delta_disks; 4744 /* reshape_position must be on a new-stripe boundary, and one 4745 * further up in new geometry must map after here in old 4746 * geometry. 4747 */ 4748 here_new = mddev->reshape_position; 4749 if (sector_div(here_new, mddev->new_chunk_sectors * 4750 (mddev->raid_disks - max_degraded))) { 4751 printk(KERN_ERR "md/raid:%s: reshape_position not " 4752 "on a stripe boundary\n", mdname(mddev)); 4753 return -EINVAL; 4754 } 4755 reshape_offset = here_new * mddev->new_chunk_sectors; 4756 /* here_new is the stripe we will write to */ 4757 here_old = mddev->reshape_position; 4758 sector_div(here_old, mddev->chunk_sectors * 4759 (old_disks-max_degraded)); 4760 /* here_old is the first stripe that we might need to read 4761 * from */ 4762 if (mddev->delta_disks == 0) { 4763 /* We cannot be sure it is safe to start an in-place 4764 * reshape. It is only safe if user-space if monitoring 4765 * and taking constant backups. 4766 * mdadm always starts a situation like this in 4767 * readonly mode so it can take control before 4768 * allowing any writes. So just check for that. 4769 */ 4770 if ((here_new * mddev->new_chunk_sectors != 4771 here_old * mddev->chunk_sectors) || 4772 mddev->ro == 0) { 4773 printk(KERN_ERR "md/raid:%s: in-place reshape must be started" 4774 " in read-only mode - aborting\n", 4775 mdname(mddev)); 4776 return -EINVAL; 4777 } 4778 } else if (mddev->delta_disks < 0 4779 ? (here_new * mddev->new_chunk_sectors <= 4780 here_old * mddev->chunk_sectors) 4781 : (here_new * mddev->new_chunk_sectors >= 4782 here_old * mddev->chunk_sectors)) { 4783 /* Reading from the same stripe as writing to - bad */ 4784 printk(KERN_ERR "md/raid:%s: reshape_position too early for " 4785 "auto-recovery - aborting.\n", 4786 mdname(mddev)); 4787 return -EINVAL; 4788 } 4789 printk(KERN_INFO "md/raid:%s: reshape will continue\n", 4790 mdname(mddev)); 4791 /* OK, we should be able to continue; */ 4792 } else { 4793 BUG_ON(mddev->level != mddev->new_level); 4794 BUG_ON(mddev->layout != mddev->new_layout); 4795 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors); 4796 BUG_ON(mddev->delta_disks != 0); 4797 } 4798 4799 if (mddev->private == NULL) 4800 conf = setup_conf(mddev); 4801 else 4802 conf = mddev->private; 4803 4804 if (IS_ERR(conf)) 4805 return PTR_ERR(conf); 4806 4807 mddev->thread = conf->thread; 4808 conf->thread = NULL; 4809 mddev->private = conf; 4810 4811 /* 4812 * 0 for a fully functional array, 1 or 2 for a degraded array. 4813 */ 4814 list_for_each_entry(rdev, &mddev->disks, same_set) { 4815 if (rdev->raid_disk < 0) 4816 continue; 4817 if (test_bit(In_sync, &rdev->flags)) { 4818 working_disks++; 4819 continue; 4820 } 4821 /* This disc is not fully in-sync. However if it 4822 * just stored parity (beyond the recovery_offset), 4823 * when we don't need to be concerned about the 4824 * array being dirty. 4825 * When reshape goes 'backwards', we never have 4826 * partially completed devices, so we only need 4827 * to worry about reshape going forwards. 4828 */ 4829 /* Hack because v0.91 doesn't store recovery_offset properly. */ 4830 if (mddev->major_version == 0 && 4831 mddev->minor_version > 90) 4832 rdev->recovery_offset = reshape_offset; 4833 4834 if (rdev->recovery_offset < reshape_offset) { 4835 /* We need to check old and new layout */ 4836 if (!only_parity(rdev->raid_disk, 4837 conf->algorithm, 4838 conf->raid_disks, 4839 conf->max_degraded)) 4840 continue; 4841 } 4842 if (!only_parity(rdev->raid_disk, 4843 conf->prev_algo, 4844 conf->previous_raid_disks, 4845 conf->max_degraded)) 4846 continue; 4847 dirty_parity_disks++; 4848 } 4849 4850 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks) 4851 - working_disks); 4852 4853 if (has_failed(conf)) { 4854 printk(KERN_ERR "md/raid:%s: not enough operational devices" 4855 " (%d/%d failed)\n", 4856 mdname(mddev), mddev->degraded, conf->raid_disks); 4857 goto abort; 4858 } 4859 4860 /* device size must be a multiple of chunk size */ 4861 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1); 4862 mddev->resync_max_sectors = mddev->dev_sectors; 4863 4864 if (mddev->degraded > dirty_parity_disks && 4865 mddev->recovery_cp != MaxSector) { 4866 if (mddev->ok_start_degraded) 4867 printk(KERN_WARNING 4868 "md/raid:%s: starting dirty degraded array" 4869 " - data corruption possible.\n", 4870 mdname(mddev)); 4871 else { 4872 printk(KERN_ERR 4873 "md/raid:%s: cannot start dirty degraded array.\n", 4874 mdname(mddev)); 4875 goto abort; 4876 } 4877 } 4878 4879 if (mddev->degraded == 0) 4880 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d" 4881 " devices, algorithm %d\n", mdname(mddev), conf->level, 4882 mddev->raid_disks-mddev->degraded, mddev->raid_disks, 4883 mddev->new_layout); 4884 else 4885 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d" 4886 " out of %d devices, algorithm %d\n", 4887 mdname(mddev), conf->level, 4888 mddev->raid_disks - mddev->degraded, 4889 mddev->raid_disks, mddev->new_layout); 4890 4891 print_raid5_conf(conf); 4892 4893 if (conf->reshape_progress != MaxSector) { 4894 conf->reshape_safe = conf->reshape_progress; 4895 atomic_set(&conf->reshape_stripes, 0); 4896 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 4897 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 4898 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 4899 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 4900 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 4901 "reshape"); 4902 } 4903 4904 4905 /* Ok, everything is just fine now */ 4906 if (mddev->to_remove == &raid5_attrs_group) 4907 mddev->to_remove = NULL; 4908 else if (mddev->kobj.sd && 4909 sysfs_create_group(&mddev->kobj, &raid5_attrs_group)) 4910 printk(KERN_WARNING 4911 "raid5: failed to create sysfs attributes for %s\n", 4912 mdname(mddev)); 4913 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 4914 4915 if (mddev->queue) { 4916 int chunk_size; 4917 /* read-ahead size must cover two whole stripes, which 4918 * is 2 * (datadisks) * chunksize where 'n' is the 4919 * number of raid devices 4920 */ 4921 int data_disks = conf->previous_raid_disks - conf->max_degraded; 4922 int stripe = data_disks * 4923 ((mddev->chunk_sectors << 9) / PAGE_SIZE); 4924 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 4925 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 4926 4927 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); 4928 4929 mddev->queue->backing_dev_info.congested_data = mddev; 4930 mddev->queue->backing_dev_info.congested_fn = raid5_congested; 4931 4932 chunk_size = mddev->chunk_sectors << 9; 4933 blk_queue_io_min(mddev->queue, chunk_size); 4934 blk_queue_io_opt(mddev->queue, chunk_size * 4935 (conf->raid_disks - conf->max_degraded)); 4936 4937 list_for_each_entry(rdev, &mddev->disks, same_set) 4938 disk_stack_limits(mddev->gendisk, rdev->bdev, 4939 rdev->data_offset << 9); 4940 } 4941 4942 return 0; 4943 abort: 4944 md_unregister_thread(mddev->thread); 4945 mddev->thread = NULL; 4946 if (conf) { 4947 print_raid5_conf(conf); 4948 free_conf(conf); 4949 } 4950 mddev->private = NULL; 4951 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev)); 4952 return -EIO; 4953 } 4954 4955 static int stop(mddev_t *mddev) 4956 { 4957 raid5_conf_t *conf = mddev->private; 4958 4959 md_unregister_thread(mddev->thread); 4960 mddev->thread = NULL; 4961 if (mddev->queue) 4962 mddev->queue->backing_dev_info.congested_fn = NULL; 4963 free_conf(conf); 4964 mddev->private = NULL; 4965 mddev->to_remove = &raid5_attrs_group; 4966 return 0; 4967 } 4968 4969 #ifdef DEBUG 4970 static void print_sh(struct seq_file *seq, struct stripe_head *sh) 4971 { 4972 int i; 4973 4974 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n", 4975 (unsigned long long)sh->sector, sh->pd_idx, sh->state); 4976 seq_printf(seq, "sh %llu, count %d.\n", 4977 (unsigned long long)sh->sector, atomic_read(&sh->count)); 4978 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector); 4979 for (i = 0; i < sh->disks; i++) { 4980 seq_printf(seq, "(cache%d: %p %ld) ", 4981 i, sh->dev[i].page, sh->dev[i].flags); 4982 } 4983 seq_printf(seq, "\n"); 4984 } 4985 4986 static void printall(struct seq_file *seq, raid5_conf_t *conf) 4987 { 4988 struct stripe_head *sh; 4989 struct hlist_node *hn; 4990 int i; 4991 4992 spin_lock_irq(&conf->device_lock); 4993 for (i = 0; i < NR_HASH; i++) { 4994 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { 4995 if (sh->raid_conf != conf) 4996 continue; 4997 print_sh(seq, sh); 4998 } 4999 } 5000 spin_unlock_irq(&conf->device_lock); 5001 } 5002 #endif 5003 5004 static void status(struct seq_file *seq, mddev_t *mddev) 5005 { 5006 raid5_conf_t *conf = mddev->private; 5007 int i; 5008 5009 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, 5010 mddev->chunk_sectors / 2, mddev->layout); 5011 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); 5012 for (i = 0; i < conf->raid_disks; i++) 5013 seq_printf (seq, "%s", 5014 conf->disks[i].rdev && 5015 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 5016 seq_printf (seq, "]"); 5017 #ifdef DEBUG 5018 seq_printf (seq, "\n"); 5019 printall(seq, conf); 5020 #endif 5021 } 5022 5023 static void print_raid5_conf (raid5_conf_t *conf) 5024 { 5025 int i; 5026 struct disk_info *tmp; 5027 5028 printk(KERN_DEBUG "RAID conf printout:\n"); 5029 if (!conf) { 5030 printk("(conf==NULL)\n"); 5031 return; 5032 } 5033 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level, 5034 conf->raid_disks, 5035 conf->raid_disks - conf->mddev->degraded); 5036 5037 for (i = 0; i < conf->raid_disks; i++) { 5038 char b[BDEVNAME_SIZE]; 5039 tmp = conf->disks + i; 5040 if (tmp->rdev) 5041 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n", 5042 i, !test_bit(Faulty, &tmp->rdev->flags), 5043 bdevname(tmp->rdev->bdev, b)); 5044 } 5045 } 5046 5047 static int raid5_spare_active(mddev_t *mddev) 5048 { 5049 int i; 5050 raid5_conf_t *conf = mddev->private; 5051 struct disk_info *tmp; 5052 int count = 0; 5053 unsigned long flags; 5054 5055 for (i = 0; i < conf->raid_disks; i++) { 5056 tmp = conf->disks + i; 5057 if (tmp->rdev 5058 && tmp->rdev->recovery_offset == MaxSector 5059 && !test_bit(Faulty, &tmp->rdev->flags) 5060 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { 5061 count++; 5062 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); 5063 } 5064 } 5065 spin_lock_irqsave(&conf->device_lock, flags); 5066 mddev->degraded -= count; 5067 spin_unlock_irqrestore(&conf->device_lock, flags); 5068 print_raid5_conf(conf); 5069 return count; 5070 } 5071 5072 static int raid5_remove_disk(mddev_t *mddev, int number) 5073 { 5074 raid5_conf_t *conf = mddev->private; 5075 int err = 0; 5076 mdk_rdev_t *rdev; 5077 struct disk_info *p = conf->disks + number; 5078 5079 print_raid5_conf(conf); 5080 rdev = p->rdev; 5081 if (rdev) { 5082 if (number >= conf->raid_disks && 5083 conf->reshape_progress == MaxSector) 5084 clear_bit(In_sync, &rdev->flags); 5085 5086 if (test_bit(In_sync, &rdev->flags) || 5087 atomic_read(&rdev->nr_pending)) { 5088 err = -EBUSY; 5089 goto abort; 5090 } 5091 /* Only remove non-faulty devices if recovery 5092 * isn't possible. 5093 */ 5094 if (!test_bit(Faulty, &rdev->flags) && 5095 mddev->recovery_disabled != conf->recovery_disabled && 5096 !has_failed(conf) && 5097 number < conf->raid_disks) { 5098 err = -EBUSY; 5099 goto abort; 5100 } 5101 p->rdev = NULL; 5102 synchronize_rcu(); 5103 if (atomic_read(&rdev->nr_pending)) { 5104 /* lost the race, try later */ 5105 err = -EBUSY; 5106 p->rdev = rdev; 5107 } 5108 } 5109 abort: 5110 5111 print_raid5_conf(conf); 5112 return err; 5113 } 5114 5115 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) 5116 { 5117 raid5_conf_t *conf = mddev->private; 5118 int err = -EEXIST; 5119 int disk; 5120 struct disk_info *p; 5121 int first = 0; 5122 int last = conf->raid_disks - 1; 5123 5124 if (mddev->recovery_disabled == conf->recovery_disabled) 5125 return -EBUSY; 5126 5127 if (has_failed(conf)) 5128 /* no point adding a device */ 5129 return -EINVAL; 5130 5131 if (rdev->raid_disk >= 0) 5132 first = last = rdev->raid_disk; 5133 5134 /* 5135 * find the disk ... but prefer rdev->saved_raid_disk 5136 * if possible. 5137 */ 5138 if (rdev->saved_raid_disk >= 0 && 5139 rdev->saved_raid_disk >= first && 5140 conf->disks[rdev->saved_raid_disk].rdev == NULL) 5141 disk = rdev->saved_raid_disk; 5142 else 5143 disk = first; 5144 for ( ; disk <= last ; disk++) 5145 if ((p=conf->disks + disk)->rdev == NULL) { 5146 clear_bit(In_sync, &rdev->flags); 5147 rdev->raid_disk = disk; 5148 err = 0; 5149 if (rdev->saved_raid_disk != disk) 5150 conf->fullsync = 1; 5151 rcu_assign_pointer(p->rdev, rdev); 5152 break; 5153 } 5154 print_raid5_conf(conf); 5155 return err; 5156 } 5157 5158 static int raid5_resize(mddev_t *mddev, sector_t sectors) 5159 { 5160 /* no resync is happening, and there is enough space 5161 * on all devices, so we can resize. 5162 * We need to make sure resync covers any new space. 5163 * If the array is shrinking we should possibly wait until 5164 * any io in the removed space completes, but it hardly seems 5165 * worth it. 5166 */ 5167 sectors &= ~((sector_t)mddev->chunk_sectors - 1); 5168 md_set_array_sectors(mddev, raid5_size(mddev, sectors, 5169 mddev->raid_disks)); 5170 if (mddev->array_sectors > 5171 raid5_size(mddev, sectors, mddev->raid_disks)) 5172 return -EINVAL; 5173 set_capacity(mddev->gendisk, mddev->array_sectors); 5174 revalidate_disk(mddev->gendisk); 5175 if (sectors > mddev->dev_sectors && 5176 mddev->recovery_cp > mddev->dev_sectors) { 5177 mddev->recovery_cp = mddev->dev_sectors; 5178 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 5179 } 5180 mddev->dev_sectors = sectors; 5181 mddev->resync_max_sectors = sectors; 5182 return 0; 5183 } 5184 5185 static int check_stripe_cache(mddev_t *mddev) 5186 { 5187 /* Can only proceed if there are plenty of stripe_heads. 5188 * We need a minimum of one full stripe,, and for sensible progress 5189 * it is best to have about 4 times that. 5190 * If we require 4 times, then the default 256 4K stripe_heads will 5191 * allow for chunk sizes up to 256K, which is probably OK. 5192 * If the chunk size is greater, user-space should request more 5193 * stripe_heads first. 5194 */ 5195 raid5_conf_t *conf = mddev->private; 5196 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 5197 > conf->max_nr_stripes || 5198 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 5199 > conf->max_nr_stripes) { 5200 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n", 5201 mdname(mddev), 5202 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) 5203 / STRIPE_SIZE)*4); 5204 return 0; 5205 } 5206 return 1; 5207 } 5208 5209 static int check_reshape(mddev_t *mddev) 5210 { 5211 raid5_conf_t *conf = mddev->private; 5212 5213 if (mddev->delta_disks == 0 && 5214 mddev->new_layout == mddev->layout && 5215 mddev->new_chunk_sectors == mddev->chunk_sectors) 5216 return 0; /* nothing to do */ 5217 if (mddev->bitmap) 5218 /* Cannot grow a bitmap yet */ 5219 return -EBUSY; 5220 if (has_failed(conf)) 5221 return -EINVAL; 5222 if (mddev->delta_disks < 0) { 5223 /* We might be able to shrink, but the devices must 5224 * be made bigger first. 5225 * For raid6, 4 is the minimum size. 5226 * Otherwise 2 is the minimum 5227 */ 5228 int min = 2; 5229 if (mddev->level == 6) 5230 min = 4; 5231 if (mddev->raid_disks + mddev->delta_disks < min) 5232 return -EINVAL; 5233 } 5234 5235 if (!check_stripe_cache(mddev)) 5236 return -ENOSPC; 5237 5238 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); 5239 } 5240 5241 static int raid5_start_reshape(mddev_t *mddev) 5242 { 5243 raid5_conf_t *conf = mddev->private; 5244 mdk_rdev_t *rdev; 5245 int spares = 0; 5246 unsigned long flags; 5247 5248 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 5249 return -EBUSY; 5250 5251 if (!check_stripe_cache(mddev)) 5252 return -ENOSPC; 5253 5254 list_for_each_entry(rdev, &mddev->disks, same_set) 5255 if (!test_bit(In_sync, &rdev->flags) 5256 && !test_bit(Faulty, &rdev->flags)) 5257 spares++; 5258 5259 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded) 5260 /* Not enough devices even to make a degraded array 5261 * of that size 5262 */ 5263 return -EINVAL; 5264 5265 /* Refuse to reduce size of the array. Any reductions in 5266 * array size must be through explicit setting of array_size 5267 * attribute. 5268 */ 5269 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks) 5270 < mddev->array_sectors) { 5271 printk(KERN_ERR "md/raid:%s: array size must be reduced " 5272 "before number of disks\n", mdname(mddev)); 5273 return -EINVAL; 5274 } 5275 5276 atomic_set(&conf->reshape_stripes, 0); 5277 spin_lock_irq(&conf->device_lock); 5278 conf->previous_raid_disks = conf->raid_disks; 5279 conf->raid_disks += mddev->delta_disks; 5280 conf->prev_chunk_sectors = conf->chunk_sectors; 5281 conf->chunk_sectors = mddev->new_chunk_sectors; 5282 conf->prev_algo = conf->algorithm; 5283 conf->algorithm = mddev->new_layout; 5284 if (mddev->delta_disks < 0) 5285 conf->reshape_progress = raid5_size(mddev, 0, 0); 5286 else 5287 conf->reshape_progress = 0; 5288 conf->reshape_safe = conf->reshape_progress; 5289 conf->generation++; 5290 spin_unlock_irq(&conf->device_lock); 5291 5292 /* Add some new drives, as many as will fit. 5293 * We know there are enough to make the newly sized array work. 5294 * Don't add devices if we are reducing the number of 5295 * devices in the array. This is because it is not possible 5296 * to correctly record the "partially reconstructed" state of 5297 * such devices during the reshape and confusion could result. 5298 */ 5299 if (mddev->delta_disks >= 0) { 5300 int added_devices = 0; 5301 list_for_each_entry(rdev, &mddev->disks, same_set) 5302 if (rdev->raid_disk < 0 && 5303 !test_bit(Faulty, &rdev->flags)) { 5304 if (raid5_add_disk(mddev, rdev) == 0) { 5305 if (rdev->raid_disk 5306 >= conf->previous_raid_disks) { 5307 set_bit(In_sync, &rdev->flags); 5308 added_devices++; 5309 } else 5310 rdev->recovery_offset = 0; 5311 5312 if (sysfs_link_rdev(mddev, rdev)) 5313 /* Failure here is OK */; 5314 } 5315 } else if (rdev->raid_disk >= conf->previous_raid_disks 5316 && !test_bit(Faulty, &rdev->flags)) { 5317 /* This is a spare that was manually added */ 5318 set_bit(In_sync, &rdev->flags); 5319 added_devices++; 5320 } 5321 5322 /* When a reshape changes the number of devices, 5323 * ->degraded is measured against the larger of the 5324 * pre and post number of devices. 5325 */ 5326 spin_lock_irqsave(&conf->device_lock, flags); 5327 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks) 5328 - added_devices; 5329 spin_unlock_irqrestore(&conf->device_lock, flags); 5330 } 5331 mddev->raid_disks = conf->raid_disks; 5332 mddev->reshape_position = conf->reshape_progress; 5333 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5334 5335 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); 5336 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); 5337 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); 5338 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); 5339 mddev->sync_thread = md_register_thread(md_do_sync, mddev, 5340 "reshape"); 5341 if (!mddev->sync_thread) { 5342 mddev->recovery = 0; 5343 spin_lock_irq(&conf->device_lock); 5344 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks; 5345 conf->reshape_progress = MaxSector; 5346 spin_unlock_irq(&conf->device_lock); 5347 return -EAGAIN; 5348 } 5349 conf->reshape_checkpoint = jiffies; 5350 md_wakeup_thread(mddev->sync_thread); 5351 md_new_event(mddev); 5352 return 0; 5353 } 5354 5355 /* This is called from the reshape thread and should make any 5356 * changes needed in 'conf' 5357 */ 5358 static void end_reshape(raid5_conf_t *conf) 5359 { 5360 5361 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { 5362 5363 spin_lock_irq(&conf->device_lock); 5364 conf->previous_raid_disks = conf->raid_disks; 5365 conf->reshape_progress = MaxSector; 5366 spin_unlock_irq(&conf->device_lock); 5367 wake_up(&conf->wait_for_overlap); 5368 5369 /* read-ahead size must cover two whole stripes, which is 5370 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices 5371 */ 5372 if (conf->mddev->queue) { 5373 int data_disks = conf->raid_disks - conf->max_degraded; 5374 int stripe = data_disks * ((conf->chunk_sectors << 9) 5375 / PAGE_SIZE); 5376 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 5377 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 5378 } 5379 } 5380 } 5381 5382 /* This is called from the raid5d thread with mddev_lock held. 5383 * It makes config changes to the device. 5384 */ 5385 static void raid5_finish_reshape(mddev_t *mddev) 5386 { 5387 raid5_conf_t *conf = mddev->private; 5388 5389 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { 5390 5391 if (mddev->delta_disks > 0) { 5392 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); 5393 set_capacity(mddev->gendisk, mddev->array_sectors); 5394 revalidate_disk(mddev->gendisk); 5395 } else { 5396 int d; 5397 mddev->degraded = conf->raid_disks; 5398 for (d = 0; d < conf->raid_disks ; d++) 5399 if (conf->disks[d].rdev && 5400 test_bit(In_sync, 5401 &conf->disks[d].rdev->flags)) 5402 mddev->degraded--; 5403 for (d = conf->raid_disks ; 5404 d < conf->raid_disks - mddev->delta_disks; 5405 d++) { 5406 mdk_rdev_t *rdev = conf->disks[d].rdev; 5407 if (rdev && raid5_remove_disk(mddev, d) == 0) { 5408 sysfs_unlink_rdev(mddev, rdev); 5409 rdev->raid_disk = -1; 5410 } 5411 } 5412 } 5413 mddev->layout = conf->algorithm; 5414 mddev->chunk_sectors = conf->chunk_sectors; 5415 mddev->reshape_position = MaxSector; 5416 mddev->delta_disks = 0; 5417 } 5418 } 5419 5420 static void raid5_quiesce(mddev_t *mddev, int state) 5421 { 5422 raid5_conf_t *conf = mddev->private; 5423 5424 switch(state) { 5425 case 2: /* resume for a suspend */ 5426 wake_up(&conf->wait_for_overlap); 5427 break; 5428 5429 case 1: /* stop all writes */ 5430 spin_lock_irq(&conf->device_lock); 5431 /* '2' tells resync/reshape to pause so that all 5432 * active stripes can drain 5433 */ 5434 conf->quiesce = 2; 5435 wait_event_lock_irq(conf->wait_for_stripe, 5436 atomic_read(&conf->active_stripes) == 0 && 5437 atomic_read(&conf->active_aligned_reads) == 0, 5438 conf->device_lock, /* nothing */); 5439 conf->quiesce = 1; 5440 spin_unlock_irq(&conf->device_lock); 5441 /* allow reshape to continue */ 5442 wake_up(&conf->wait_for_overlap); 5443 break; 5444 5445 case 0: /* re-enable writes */ 5446 spin_lock_irq(&conf->device_lock); 5447 conf->quiesce = 0; 5448 wake_up(&conf->wait_for_stripe); 5449 wake_up(&conf->wait_for_overlap); 5450 spin_unlock_irq(&conf->device_lock); 5451 break; 5452 } 5453 } 5454 5455 5456 static void *raid45_takeover_raid0(mddev_t *mddev, int level) 5457 { 5458 struct raid0_private_data *raid0_priv = mddev->private; 5459 sector_t sectors; 5460 5461 /* for raid0 takeover only one zone is supported */ 5462 if (raid0_priv->nr_strip_zones > 1) { 5463 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n", 5464 mdname(mddev)); 5465 return ERR_PTR(-EINVAL); 5466 } 5467 5468 sectors = raid0_priv->strip_zone[0].zone_end; 5469 sector_div(sectors, raid0_priv->strip_zone[0].nb_dev); 5470 mddev->dev_sectors = sectors; 5471 mddev->new_level = level; 5472 mddev->new_layout = ALGORITHM_PARITY_N; 5473 mddev->new_chunk_sectors = mddev->chunk_sectors; 5474 mddev->raid_disks += 1; 5475 mddev->delta_disks = 1; 5476 /* make sure it will be not marked as dirty */ 5477 mddev->recovery_cp = MaxSector; 5478 5479 return setup_conf(mddev); 5480 } 5481 5482 5483 static void *raid5_takeover_raid1(mddev_t *mddev) 5484 { 5485 int chunksect; 5486 5487 if (mddev->raid_disks != 2 || 5488 mddev->degraded > 1) 5489 return ERR_PTR(-EINVAL); 5490 5491 /* Should check if there are write-behind devices? */ 5492 5493 chunksect = 64*2; /* 64K by default */ 5494 5495 /* The array must be an exact multiple of chunksize */ 5496 while (chunksect && (mddev->array_sectors & (chunksect-1))) 5497 chunksect >>= 1; 5498 5499 if ((chunksect<<9) < STRIPE_SIZE) 5500 /* array size does not allow a suitable chunk size */ 5501 return ERR_PTR(-EINVAL); 5502 5503 mddev->new_level = 5; 5504 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; 5505 mddev->new_chunk_sectors = chunksect; 5506 5507 return setup_conf(mddev); 5508 } 5509 5510 static void *raid5_takeover_raid6(mddev_t *mddev) 5511 { 5512 int new_layout; 5513 5514 switch (mddev->layout) { 5515 case ALGORITHM_LEFT_ASYMMETRIC_6: 5516 new_layout = ALGORITHM_LEFT_ASYMMETRIC; 5517 break; 5518 case ALGORITHM_RIGHT_ASYMMETRIC_6: 5519 new_layout = ALGORITHM_RIGHT_ASYMMETRIC; 5520 break; 5521 case ALGORITHM_LEFT_SYMMETRIC_6: 5522 new_layout = ALGORITHM_LEFT_SYMMETRIC; 5523 break; 5524 case ALGORITHM_RIGHT_SYMMETRIC_6: 5525 new_layout = ALGORITHM_RIGHT_SYMMETRIC; 5526 break; 5527 case ALGORITHM_PARITY_0_6: 5528 new_layout = ALGORITHM_PARITY_0; 5529 break; 5530 case ALGORITHM_PARITY_N: 5531 new_layout = ALGORITHM_PARITY_N; 5532 break; 5533 default: 5534 return ERR_PTR(-EINVAL); 5535 } 5536 mddev->new_level = 5; 5537 mddev->new_layout = new_layout; 5538 mddev->delta_disks = -1; 5539 mddev->raid_disks -= 1; 5540 return setup_conf(mddev); 5541 } 5542 5543 5544 static int raid5_check_reshape(mddev_t *mddev) 5545 { 5546 /* For a 2-drive array, the layout and chunk size can be changed 5547 * immediately as not restriping is needed. 5548 * For larger arrays we record the new value - after validation 5549 * to be used by a reshape pass. 5550 */ 5551 raid5_conf_t *conf = mddev->private; 5552 int new_chunk = mddev->new_chunk_sectors; 5553 5554 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout)) 5555 return -EINVAL; 5556 if (new_chunk > 0) { 5557 if (!is_power_of_2(new_chunk)) 5558 return -EINVAL; 5559 if (new_chunk < (PAGE_SIZE>>9)) 5560 return -EINVAL; 5561 if (mddev->array_sectors & (new_chunk-1)) 5562 /* not factor of array size */ 5563 return -EINVAL; 5564 } 5565 5566 /* They look valid */ 5567 5568 if (mddev->raid_disks == 2) { 5569 /* can make the change immediately */ 5570 if (mddev->new_layout >= 0) { 5571 conf->algorithm = mddev->new_layout; 5572 mddev->layout = mddev->new_layout; 5573 } 5574 if (new_chunk > 0) { 5575 conf->chunk_sectors = new_chunk ; 5576 mddev->chunk_sectors = new_chunk; 5577 } 5578 set_bit(MD_CHANGE_DEVS, &mddev->flags); 5579 md_wakeup_thread(mddev->thread); 5580 } 5581 return check_reshape(mddev); 5582 } 5583 5584 static int raid6_check_reshape(mddev_t *mddev) 5585 { 5586 int new_chunk = mddev->new_chunk_sectors; 5587 5588 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout)) 5589 return -EINVAL; 5590 if (new_chunk > 0) { 5591 if (!is_power_of_2(new_chunk)) 5592 return -EINVAL; 5593 if (new_chunk < (PAGE_SIZE >> 9)) 5594 return -EINVAL; 5595 if (mddev->array_sectors & (new_chunk-1)) 5596 /* not factor of array size */ 5597 return -EINVAL; 5598 } 5599 5600 /* They look valid */ 5601 return check_reshape(mddev); 5602 } 5603 5604 static void *raid5_takeover(mddev_t *mddev) 5605 { 5606 /* raid5 can take over: 5607 * raid0 - if there is only one strip zone - make it a raid4 layout 5608 * raid1 - if there are two drives. We need to know the chunk size 5609 * raid4 - trivial - just use a raid4 layout. 5610 * raid6 - Providing it is a *_6 layout 5611 */ 5612 if (mddev->level == 0) 5613 return raid45_takeover_raid0(mddev, 5); 5614 if (mddev->level == 1) 5615 return raid5_takeover_raid1(mddev); 5616 if (mddev->level == 4) { 5617 mddev->new_layout = ALGORITHM_PARITY_N; 5618 mddev->new_level = 5; 5619 return setup_conf(mddev); 5620 } 5621 if (mddev->level == 6) 5622 return raid5_takeover_raid6(mddev); 5623 5624 return ERR_PTR(-EINVAL); 5625 } 5626 5627 static void *raid4_takeover(mddev_t *mddev) 5628 { 5629 /* raid4 can take over: 5630 * raid0 - if there is only one strip zone 5631 * raid5 - if layout is right 5632 */ 5633 if (mddev->level == 0) 5634 return raid45_takeover_raid0(mddev, 4); 5635 if (mddev->level == 5 && 5636 mddev->layout == ALGORITHM_PARITY_N) { 5637 mddev->new_layout = 0; 5638 mddev->new_level = 4; 5639 return setup_conf(mddev); 5640 } 5641 return ERR_PTR(-EINVAL); 5642 } 5643 5644 static struct mdk_personality raid5_personality; 5645 5646 static void *raid6_takeover(mddev_t *mddev) 5647 { 5648 /* Currently can only take over a raid5. We map the 5649 * personality to an equivalent raid6 personality 5650 * with the Q block at the end. 5651 */ 5652 int new_layout; 5653 5654 if (mddev->pers != &raid5_personality) 5655 return ERR_PTR(-EINVAL); 5656 if (mddev->degraded > 1) 5657 return ERR_PTR(-EINVAL); 5658 if (mddev->raid_disks > 253) 5659 return ERR_PTR(-EINVAL); 5660 if (mddev->raid_disks < 3) 5661 return ERR_PTR(-EINVAL); 5662 5663 switch (mddev->layout) { 5664 case ALGORITHM_LEFT_ASYMMETRIC: 5665 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6; 5666 break; 5667 case ALGORITHM_RIGHT_ASYMMETRIC: 5668 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6; 5669 break; 5670 case ALGORITHM_LEFT_SYMMETRIC: 5671 new_layout = ALGORITHM_LEFT_SYMMETRIC_6; 5672 break; 5673 case ALGORITHM_RIGHT_SYMMETRIC: 5674 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6; 5675 break; 5676 case ALGORITHM_PARITY_0: 5677 new_layout = ALGORITHM_PARITY_0_6; 5678 break; 5679 case ALGORITHM_PARITY_N: 5680 new_layout = ALGORITHM_PARITY_N; 5681 break; 5682 default: 5683 return ERR_PTR(-EINVAL); 5684 } 5685 mddev->new_level = 6; 5686 mddev->new_layout = new_layout; 5687 mddev->delta_disks = 1; 5688 mddev->raid_disks += 1; 5689 return setup_conf(mddev); 5690 } 5691 5692 5693 static struct mdk_personality raid6_personality = 5694 { 5695 .name = "raid6", 5696 .level = 6, 5697 .owner = THIS_MODULE, 5698 .make_request = make_request, 5699 .run = run, 5700 .stop = stop, 5701 .status = status, 5702 .error_handler = error, 5703 .hot_add_disk = raid5_add_disk, 5704 .hot_remove_disk= raid5_remove_disk, 5705 .spare_active = raid5_spare_active, 5706 .sync_request = sync_request, 5707 .resize = raid5_resize, 5708 .size = raid5_size, 5709 .check_reshape = raid6_check_reshape, 5710 .start_reshape = raid5_start_reshape, 5711 .finish_reshape = raid5_finish_reshape, 5712 .quiesce = raid5_quiesce, 5713 .takeover = raid6_takeover, 5714 }; 5715 static struct mdk_personality raid5_personality = 5716 { 5717 .name = "raid5", 5718 .level = 5, 5719 .owner = THIS_MODULE, 5720 .make_request = make_request, 5721 .run = run, 5722 .stop = stop, 5723 .status = status, 5724 .error_handler = error, 5725 .hot_add_disk = raid5_add_disk, 5726 .hot_remove_disk= raid5_remove_disk, 5727 .spare_active = raid5_spare_active, 5728 .sync_request = sync_request, 5729 .resize = raid5_resize, 5730 .size = raid5_size, 5731 .check_reshape = raid5_check_reshape, 5732 .start_reshape = raid5_start_reshape, 5733 .finish_reshape = raid5_finish_reshape, 5734 .quiesce = raid5_quiesce, 5735 .takeover = raid5_takeover, 5736 }; 5737 5738 static struct mdk_personality raid4_personality = 5739 { 5740 .name = "raid4", 5741 .level = 4, 5742 .owner = THIS_MODULE, 5743 .make_request = make_request, 5744 .run = run, 5745 .stop = stop, 5746 .status = status, 5747 .error_handler = error, 5748 .hot_add_disk = raid5_add_disk, 5749 .hot_remove_disk= raid5_remove_disk, 5750 .spare_active = raid5_spare_active, 5751 .sync_request = sync_request, 5752 .resize = raid5_resize, 5753 .size = raid5_size, 5754 .check_reshape = raid5_check_reshape, 5755 .start_reshape = raid5_start_reshape, 5756 .finish_reshape = raid5_finish_reshape, 5757 .quiesce = raid5_quiesce, 5758 .takeover = raid4_takeover, 5759 }; 5760 5761 static int __init raid5_init(void) 5762 { 5763 register_md_personality(&raid6_personality); 5764 register_md_personality(&raid5_personality); 5765 register_md_personality(&raid4_personality); 5766 return 0; 5767 } 5768 5769 static void raid5_exit(void) 5770 { 5771 unregister_md_personality(&raid6_personality); 5772 unregister_md_personality(&raid5_personality); 5773 unregister_md_personality(&raid4_personality); 5774 } 5775 5776 module_init(raid5_init); 5777 module_exit(raid5_exit); 5778 MODULE_LICENSE("GPL"); 5779 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD"); 5780 MODULE_ALIAS("md-personality-4"); /* RAID5 */ 5781 MODULE_ALIAS("md-raid5"); 5782 MODULE_ALIAS("md-raid4"); 5783 MODULE_ALIAS("md-level-5"); 5784 MODULE_ALIAS("md-level-4"); 5785 MODULE_ALIAS("md-personality-8"); /* RAID6 */ 5786 MODULE_ALIAS("md-raid6"); 5787 MODULE_ALIAS("md-level-6"); 5788 5789 /* This used to be two separate modules, they were: */ 5790 MODULE_ALIAS("raid5"); 5791 MODULE_ALIAS("raid6"); 5792