1 /* 2 * raid1.c : Multiple Devices driver for Linux 3 * 4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat 5 * 6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman 7 * 8 * RAID-1 management functions. 9 * 10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000 11 * 12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk> 13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au> 14 * 15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support 16 * bitmapped intelligence in resync: 17 * 18 * - bitmap marked during normal i/o 19 * - bitmap used to skip nondirty blocks during sync 20 * 21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology: 22 * - persistent bitmap code 23 * 24 * This program is free software; you can redistribute it and/or modify 25 * it under the terms of the GNU General Public License as published by 26 * the Free Software Foundation; either version 2, or (at your option) 27 * any later version. 28 * 29 * You should have received a copy of the GNU General Public License 30 * (for example /usr/src/linux/COPYING); if not, write to the Free 31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 32 */ 33 34 #include <linux/slab.h> 35 #include <linux/delay.h> 36 #include <linux/blkdev.h> 37 #include <linux/module.h> 38 #include <linux/seq_file.h> 39 #include <linux/ratelimit.h> 40 #include <trace/events/block.h> 41 #include "md.h" 42 #include "raid1.h" 43 #include "bitmap.h" 44 45 #define UNSUPPORTED_MDDEV_FLAGS \ 46 ((1L << MD_HAS_JOURNAL) | \ 47 (1L << MD_JOURNAL_CLEAN)) 48 49 /* 50 * Number of guaranteed r1bios in case of extreme VM load: 51 */ 52 #define NR_RAID1_BIOS 256 53 54 /* when we get a read error on a read-only array, we redirect to another 55 * device without failing the first device, or trying to over-write to 56 * correct the read error. To keep track of bad blocks on a per-bio 57 * level, we store IO_BLOCKED in the appropriate 'bios' pointer 58 */ 59 #define IO_BLOCKED ((struct bio *)1) 60 /* When we successfully write to a known bad-block, we need to remove the 61 * bad-block marking which must be done from process context. So we record 62 * the success by setting devs[n].bio to IO_MADE_GOOD 63 */ 64 #define IO_MADE_GOOD ((struct bio *)2) 65 66 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) 67 68 /* When there are this many requests queue to be written by 69 * the raid1 thread, we become 'congested' to provide back-pressure 70 * for writeback. 71 */ 72 static int max_queued_requests = 1024; 73 74 static void allow_barrier(struct r1conf *conf, sector_t start_next_window, 75 sector_t bi_sector); 76 static void lower_barrier(struct r1conf *conf); 77 78 #define raid1_log(md, fmt, args...) \ 79 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0) 80 81 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) 82 { 83 struct pool_info *pi = data; 84 int size = offsetof(struct r1bio, bios[pi->raid_disks]); 85 86 /* allocate a r1bio with room for raid_disks entries in the bios array */ 87 return kzalloc(size, gfp_flags); 88 } 89 90 static void r1bio_pool_free(void *r1_bio, void *data) 91 { 92 kfree(r1_bio); 93 } 94 95 #define RESYNC_BLOCK_SIZE (64*1024) 96 #define RESYNC_DEPTH 32 97 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) 98 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) 99 #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH) 100 #define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9) 101 #define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW) 102 #define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9) 103 #define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS) 104 105 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) 106 { 107 struct pool_info *pi = data; 108 struct r1bio *r1_bio; 109 struct bio *bio; 110 int need_pages; 111 int i, j; 112 113 r1_bio = r1bio_pool_alloc(gfp_flags, pi); 114 if (!r1_bio) 115 return NULL; 116 117 /* 118 * Allocate bios : 1 for reading, n-1 for writing 119 */ 120 for (j = pi->raid_disks ; j-- ; ) { 121 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); 122 if (!bio) 123 goto out_free_bio; 124 r1_bio->bios[j] = bio; 125 } 126 /* 127 * Allocate RESYNC_PAGES data pages and attach them to 128 * the first bio. 129 * If this is a user-requested check/repair, allocate 130 * RESYNC_PAGES for each bio. 131 */ 132 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) 133 need_pages = pi->raid_disks; 134 else 135 need_pages = 1; 136 for (j = 0; j < need_pages; j++) { 137 bio = r1_bio->bios[j]; 138 bio->bi_vcnt = RESYNC_PAGES; 139 140 if (bio_alloc_pages(bio, gfp_flags)) 141 goto out_free_pages; 142 } 143 /* If not user-requests, copy the page pointers to all bios */ 144 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { 145 for (i=0; i<RESYNC_PAGES ; i++) 146 for (j=1; j<pi->raid_disks; j++) 147 r1_bio->bios[j]->bi_io_vec[i].bv_page = 148 r1_bio->bios[0]->bi_io_vec[i].bv_page; 149 } 150 151 r1_bio->master_bio = NULL; 152 153 return r1_bio; 154 155 out_free_pages: 156 while (--j >= 0) 157 bio_free_pages(r1_bio->bios[j]); 158 159 out_free_bio: 160 while (++j < pi->raid_disks) 161 bio_put(r1_bio->bios[j]); 162 r1bio_pool_free(r1_bio, data); 163 return NULL; 164 } 165 166 static void r1buf_pool_free(void *__r1_bio, void *data) 167 { 168 struct pool_info *pi = data; 169 int i,j; 170 struct r1bio *r1bio = __r1_bio; 171 172 for (i = 0; i < RESYNC_PAGES; i++) 173 for (j = pi->raid_disks; j-- ;) { 174 if (j == 0 || 175 r1bio->bios[j]->bi_io_vec[i].bv_page != 176 r1bio->bios[0]->bi_io_vec[i].bv_page) 177 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page); 178 } 179 for (i=0 ; i < pi->raid_disks; i++) 180 bio_put(r1bio->bios[i]); 181 182 r1bio_pool_free(r1bio, data); 183 } 184 185 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio) 186 { 187 int i; 188 189 for (i = 0; i < conf->raid_disks * 2; i++) { 190 struct bio **bio = r1_bio->bios + i; 191 if (!BIO_SPECIAL(*bio)) 192 bio_put(*bio); 193 *bio = NULL; 194 } 195 } 196 197 static void free_r1bio(struct r1bio *r1_bio) 198 { 199 struct r1conf *conf = r1_bio->mddev->private; 200 201 put_all_bios(conf, r1_bio); 202 mempool_free(r1_bio, conf->r1bio_pool); 203 } 204 205 static void put_buf(struct r1bio *r1_bio) 206 { 207 struct r1conf *conf = r1_bio->mddev->private; 208 int i; 209 210 for (i = 0; i < conf->raid_disks * 2; i++) { 211 struct bio *bio = r1_bio->bios[i]; 212 if (bio->bi_end_io) 213 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev); 214 } 215 216 mempool_free(r1_bio, conf->r1buf_pool); 217 218 lower_barrier(conf); 219 } 220 221 static void reschedule_retry(struct r1bio *r1_bio) 222 { 223 unsigned long flags; 224 struct mddev *mddev = r1_bio->mddev; 225 struct r1conf *conf = mddev->private; 226 227 spin_lock_irqsave(&conf->device_lock, flags); 228 list_add(&r1_bio->retry_list, &conf->retry_list); 229 conf->nr_queued ++; 230 spin_unlock_irqrestore(&conf->device_lock, flags); 231 232 wake_up(&conf->wait_barrier); 233 md_wakeup_thread(mddev->thread); 234 } 235 236 /* 237 * raid_end_bio_io() is called when we have finished servicing a mirrored 238 * operation and are ready to return a success/failure code to the buffer 239 * cache layer. 240 */ 241 static void call_bio_endio(struct r1bio *r1_bio) 242 { 243 struct bio *bio = r1_bio->master_bio; 244 int done; 245 struct r1conf *conf = r1_bio->mddev->private; 246 sector_t start_next_window = r1_bio->start_next_window; 247 sector_t bi_sector = bio->bi_iter.bi_sector; 248 249 if (bio->bi_phys_segments) { 250 unsigned long flags; 251 spin_lock_irqsave(&conf->device_lock, flags); 252 bio->bi_phys_segments--; 253 done = (bio->bi_phys_segments == 0); 254 spin_unlock_irqrestore(&conf->device_lock, flags); 255 /* 256 * make_request() might be waiting for 257 * bi_phys_segments to decrease 258 */ 259 wake_up(&conf->wait_barrier); 260 } else 261 done = 1; 262 263 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) 264 bio->bi_error = -EIO; 265 266 if (done) { 267 bio_endio(bio); 268 /* 269 * Wake up any possible resync thread that waits for the device 270 * to go idle. 271 */ 272 allow_barrier(conf, start_next_window, bi_sector); 273 } 274 } 275 276 static void raid_end_bio_io(struct r1bio *r1_bio) 277 { 278 struct bio *bio = r1_bio->master_bio; 279 280 /* if nobody has done the final endio yet, do it now */ 281 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 282 pr_debug("raid1: sync end %s on sectors %llu-%llu\n", 283 (bio_data_dir(bio) == WRITE) ? "write" : "read", 284 (unsigned long long) bio->bi_iter.bi_sector, 285 (unsigned long long) bio_end_sector(bio) - 1); 286 287 call_bio_endio(r1_bio); 288 } 289 free_r1bio(r1_bio); 290 } 291 292 /* 293 * Update disk head position estimator based on IRQ completion info. 294 */ 295 static inline void update_head_pos(int disk, struct r1bio *r1_bio) 296 { 297 struct r1conf *conf = r1_bio->mddev->private; 298 299 conf->mirrors[disk].head_position = 300 r1_bio->sector + (r1_bio->sectors); 301 } 302 303 /* 304 * Find the disk number which triggered given bio 305 */ 306 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio) 307 { 308 int mirror; 309 struct r1conf *conf = r1_bio->mddev->private; 310 int raid_disks = conf->raid_disks; 311 312 for (mirror = 0; mirror < raid_disks * 2; mirror++) 313 if (r1_bio->bios[mirror] == bio) 314 break; 315 316 BUG_ON(mirror == raid_disks * 2); 317 update_head_pos(mirror, r1_bio); 318 319 return mirror; 320 } 321 322 static void raid1_end_read_request(struct bio *bio) 323 { 324 int uptodate = !bio->bi_error; 325 struct r1bio *r1_bio = bio->bi_private; 326 struct r1conf *conf = r1_bio->mddev->private; 327 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev; 328 329 /* 330 * this branch is our 'one mirror IO has finished' event handler: 331 */ 332 update_head_pos(r1_bio->read_disk, r1_bio); 333 334 if (uptodate) 335 set_bit(R1BIO_Uptodate, &r1_bio->state); 336 else if (test_bit(FailFast, &rdev->flags) && 337 test_bit(R1BIO_FailFast, &r1_bio->state)) 338 /* This was a fail-fast read so we definitely 339 * want to retry */ 340 ; 341 else { 342 /* If all other devices have failed, we want to return 343 * the error upwards rather than fail the last device. 344 * Here we redefine "uptodate" to mean "Don't want to retry" 345 */ 346 unsigned long flags; 347 spin_lock_irqsave(&conf->device_lock, flags); 348 if (r1_bio->mddev->degraded == conf->raid_disks || 349 (r1_bio->mddev->degraded == conf->raid_disks-1 && 350 test_bit(In_sync, &rdev->flags))) 351 uptodate = 1; 352 spin_unlock_irqrestore(&conf->device_lock, flags); 353 } 354 355 if (uptodate) { 356 raid_end_bio_io(r1_bio); 357 rdev_dec_pending(rdev, conf->mddev); 358 } else { 359 /* 360 * oops, read error: 361 */ 362 char b[BDEVNAME_SIZE]; 363 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n", 364 mdname(conf->mddev), 365 bdevname(rdev->bdev, b), 366 (unsigned long long)r1_bio->sector); 367 set_bit(R1BIO_ReadError, &r1_bio->state); 368 reschedule_retry(r1_bio); 369 /* don't drop the reference on read_disk yet */ 370 } 371 } 372 373 static void close_write(struct r1bio *r1_bio) 374 { 375 /* it really is the end of this request */ 376 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 377 /* free extra copy of the data pages */ 378 int i = r1_bio->behind_page_count; 379 while (i--) 380 safe_put_page(r1_bio->behind_bvecs[i].bv_page); 381 kfree(r1_bio->behind_bvecs); 382 r1_bio->behind_bvecs = NULL; 383 } 384 /* clear the bitmap if all writes complete successfully */ 385 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, 386 r1_bio->sectors, 387 !test_bit(R1BIO_Degraded, &r1_bio->state), 388 test_bit(R1BIO_BehindIO, &r1_bio->state)); 389 md_write_end(r1_bio->mddev); 390 } 391 392 static void r1_bio_write_done(struct r1bio *r1_bio) 393 { 394 if (!atomic_dec_and_test(&r1_bio->remaining)) 395 return; 396 397 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 398 reschedule_retry(r1_bio); 399 else { 400 close_write(r1_bio); 401 if (test_bit(R1BIO_MadeGood, &r1_bio->state)) 402 reschedule_retry(r1_bio); 403 else 404 raid_end_bio_io(r1_bio); 405 } 406 } 407 408 static void raid1_end_write_request(struct bio *bio) 409 { 410 struct r1bio *r1_bio = bio->bi_private; 411 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state); 412 struct r1conf *conf = r1_bio->mddev->private; 413 struct bio *to_put = NULL; 414 int mirror = find_bio_disk(r1_bio, bio); 415 struct md_rdev *rdev = conf->mirrors[mirror].rdev; 416 bool discard_error; 417 418 discard_error = bio->bi_error && bio_op(bio) == REQ_OP_DISCARD; 419 420 /* 421 * 'one mirror IO has finished' event handler: 422 */ 423 if (bio->bi_error && !discard_error) { 424 set_bit(WriteErrorSeen, &rdev->flags); 425 if (!test_and_set_bit(WantReplacement, &rdev->flags)) 426 set_bit(MD_RECOVERY_NEEDED, & 427 conf->mddev->recovery); 428 429 if (test_bit(FailFast, &rdev->flags) && 430 (bio->bi_opf & MD_FAILFAST) && 431 /* We never try FailFast to WriteMostly devices */ 432 !test_bit(WriteMostly, &rdev->flags)) { 433 md_error(r1_bio->mddev, rdev); 434 if (!test_bit(Faulty, &rdev->flags)) 435 /* This is the only remaining device, 436 * We need to retry the write without 437 * FailFast 438 */ 439 set_bit(R1BIO_WriteError, &r1_bio->state); 440 else { 441 /* Finished with this branch */ 442 r1_bio->bios[mirror] = NULL; 443 to_put = bio; 444 } 445 } else 446 set_bit(R1BIO_WriteError, &r1_bio->state); 447 } else { 448 /* 449 * Set R1BIO_Uptodate in our master bio, so that we 450 * will return a good error code for to the higher 451 * levels even if IO on some other mirrored buffer 452 * fails. 453 * 454 * The 'master' represents the composite IO operation 455 * to user-side. So if something waits for IO, then it 456 * will wait for the 'master' bio. 457 */ 458 sector_t first_bad; 459 int bad_sectors; 460 461 r1_bio->bios[mirror] = NULL; 462 to_put = bio; 463 /* 464 * Do not set R1BIO_Uptodate if the current device is 465 * rebuilding or Faulty. This is because we cannot use 466 * such device for properly reading the data back (we could 467 * potentially use it, if the current write would have felt 468 * before rdev->recovery_offset, but for simplicity we don't 469 * check this here. 470 */ 471 if (test_bit(In_sync, &rdev->flags) && 472 !test_bit(Faulty, &rdev->flags)) 473 set_bit(R1BIO_Uptodate, &r1_bio->state); 474 475 /* Maybe we can clear some bad blocks. */ 476 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors, 477 &first_bad, &bad_sectors) && !discard_error) { 478 r1_bio->bios[mirror] = IO_MADE_GOOD; 479 set_bit(R1BIO_MadeGood, &r1_bio->state); 480 } 481 } 482 483 if (behind) { 484 if (test_bit(WriteMostly, &rdev->flags)) 485 atomic_dec(&r1_bio->behind_remaining); 486 487 /* 488 * In behind mode, we ACK the master bio once the I/O 489 * has safely reached all non-writemostly 490 * disks. Setting the Returned bit ensures that this 491 * gets done only once -- we don't ever want to return 492 * -EIO here, instead we'll wait 493 */ 494 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && 495 test_bit(R1BIO_Uptodate, &r1_bio->state)) { 496 /* Maybe we can return now */ 497 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 498 struct bio *mbio = r1_bio->master_bio; 499 pr_debug("raid1: behind end write sectors" 500 " %llu-%llu\n", 501 (unsigned long long) mbio->bi_iter.bi_sector, 502 (unsigned long long) bio_end_sector(mbio) - 1); 503 call_bio_endio(r1_bio); 504 } 505 } 506 } 507 if (r1_bio->bios[mirror] == NULL) 508 rdev_dec_pending(rdev, conf->mddev); 509 510 /* 511 * Let's see if all mirrored write operations have finished 512 * already. 513 */ 514 r1_bio_write_done(r1_bio); 515 516 if (to_put) 517 bio_put(to_put); 518 } 519 520 /* 521 * This routine returns the disk from which the requested read should 522 * be done. There is a per-array 'next expected sequential IO' sector 523 * number - if this matches on the next IO then we use the last disk. 524 * There is also a per-disk 'last know head position' sector that is 525 * maintained from IRQ contexts, both the normal and the resync IO 526 * completion handlers update this position correctly. If there is no 527 * perfect sequential match then we pick the disk whose head is closest. 528 * 529 * If there are 2 mirrors in the same 2 devices, performance degrades 530 * because position is mirror, not device based. 531 * 532 * The rdev for the device selected will have nr_pending incremented. 533 */ 534 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors) 535 { 536 const sector_t this_sector = r1_bio->sector; 537 int sectors; 538 int best_good_sectors; 539 int best_disk, best_dist_disk, best_pending_disk; 540 int has_nonrot_disk; 541 int disk; 542 sector_t best_dist; 543 unsigned int min_pending; 544 struct md_rdev *rdev; 545 int choose_first; 546 int choose_next_idle; 547 548 rcu_read_lock(); 549 /* 550 * Check if we can balance. We can balance on the whole 551 * device if no resync is going on, or below the resync window. 552 * We take the first readable disk when above the resync window. 553 */ 554 retry: 555 sectors = r1_bio->sectors; 556 best_disk = -1; 557 best_dist_disk = -1; 558 best_dist = MaxSector; 559 best_pending_disk = -1; 560 min_pending = UINT_MAX; 561 best_good_sectors = 0; 562 has_nonrot_disk = 0; 563 choose_next_idle = 0; 564 clear_bit(R1BIO_FailFast, &r1_bio->state); 565 566 if ((conf->mddev->recovery_cp < this_sector + sectors) || 567 (mddev_is_clustered(conf->mddev) && 568 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector, 569 this_sector + sectors))) 570 choose_first = 1; 571 else 572 choose_first = 0; 573 574 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { 575 sector_t dist; 576 sector_t first_bad; 577 int bad_sectors; 578 unsigned int pending; 579 bool nonrot; 580 581 rdev = rcu_dereference(conf->mirrors[disk].rdev); 582 if (r1_bio->bios[disk] == IO_BLOCKED 583 || rdev == NULL 584 || test_bit(Faulty, &rdev->flags)) 585 continue; 586 if (!test_bit(In_sync, &rdev->flags) && 587 rdev->recovery_offset < this_sector + sectors) 588 continue; 589 if (test_bit(WriteMostly, &rdev->flags)) { 590 /* Don't balance among write-mostly, just 591 * use the first as a last resort */ 592 if (best_dist_disk < 0) { 593 if (is_badblock(rdev, this_sector, sectors, 594 &first_bad, &bad_sectors)) { 595 if (first_bad <= this_sector) 596 /* Cannot use this */ 597 continue; 598 best_good_sectors = first_bad - this_sector; 599 } else 600 best_good_sectors = sectors; 601 best_dist_disk = disk; 602 best_pending_disk = disk; 603 } 604 continue; 605 } 606 /* This is a reasonable device to use. It might 607 * even be best. 608 */ 609 if (is_badblock(rdev, this_sector, sectors, 610 &first_bad, &bad_sectors)) { 611 if (best_dist < MaxSector) 612 /* already have a better device */ 613 continue; 614 if (first_bad <= this_sector) { 615 /* cannot read here. If this is the 'primary' 616 * device, then we must not read beyond 617 * bad_sectors from another device.. 618 */ 619 bad_sectors -= (this_sector - first_bad); 620 if (choose_first && sectors > bad_sectors) 621 sectors = bad_sectors; 622 if (best_good_sectors > sectors) 623 best_good_sectors = sectors; 624 625 } else { 626 sector_t good_sectors = first_bad - this_sector; 627 if (good_sectors > best_good_sectors) { 628 best_good_sectors = good_sectors; 629 best_disk = disk; 630 } 631 if (choose_first) 632 break; 633 } 634 continue; 635 } else 636 best_good_sectors = sectors; 637 638 if (best_disk >= 0) 639 /* At least two disks to choose from so failfast is OK */ 640 set_bit(R1BIO_FailFast, &r1_bio->state); 641 642 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev)); 643 has_nonrot_disk |= nonrot; 644 pending = atomic_read(&rdev->nr_pending); 645 dist = abs(this_sector - conf->mirrors[disk].head_position); 646 if (choose_first) { 647 best_disk = disk; 648 break; 649 } 650 /* Don't change to another disk for sequential reads */ 651 if (conf->mirrors[disk].next_seq_sect == this_sector 652 || dist == 0) { 653 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9; 654 struct raid1_info *mirror = &conf->mirrors[disk]; 655 656 best_disk = disk; 657 /* 658 * If buffered sequential IO size exceeds optimal 659 * iosize, check if there is idle disk. If yes, choose 660 * the idle disk. read_balance could already choose an 661 * idle disk before noticing it's a sequential IO in 662 * this disk. This doesn't matter because this disk 663 * will idle, next time it will be utilized after the 664 * first disk has IO size exceeds optimal iosize. In 665 * this way, iosize of the first disk will be optimal 666 * iosize at least. iosize of the second disk might be 667 * small, but not a big deal since when the second disk 668 * starts IO, the first disk is likely still busy. 669 */ 670 if (nonrot && opt_iosize > 0 && 671 mirror->seq_start != MaxSector && 672 mirror->next_seq_sect > opt_iosize && 673 mirror->next_seq_sect - opt_iosize >= 674 mirror->seq_start) { 675 choose_next_idle = 1; 676 continue; 677 } 678 break; 679 } 680 681 if (choose_next_idle) 682 continue; 683 684 if (min_pending > pending) { 685 min_pending = pending; 686 best_pending_disk = disk; 687 } 688 689 if (dist < best_dist) { 690 best_dist = dist; 691 best_dist_disk = disk; 692 } 693 } 694 695 /* 696 * If all disks are rotational, choose the closest disk. If any disk is 697 * non-rotational, choose the disk with less pending request even the 698 * disk is rotational, which might/might not be optimal for raids with 699 * mixed ratation/non-rotational disks depending on workload. 700 */ 701 if (best_disk == -1) { 702 if (has_nonrot_disk || min_pending == 0) 703 best_disk = best_pending_disk; 704 else 705 best_disk = best_dist_disk; 706 } 707 708 if (best_disk >= 0) { 709 rdev = rcu_dereference(conf->mirrors[best_disk].rdev); 710 if (!rdev) 711 goto retry; 712 atomic_inc(&rdev->nr_pending); 713 sectors = best_good_sectors; 714 715 if (conf->mirrors[best_disk].next_seq_sect != this_sector) 716 conf->mirrors[best_disk].seq_start = this_sector; 717 718 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors; 719 } 720 rcu_read_unlock(); 721 *max_sectors = sectors; 722 723 return best_disk; 724 } 725 726 static int raid1_congested(struct mddev *mddev, int bits) 727 { 728 struct r1conf *conf = mddev->private; 729 int i, ret = 0; 730 731 if ((bits & (1 << WB_async_congested)) && 732 conf->pending_count >= max_queued_requests) 733 return 1; 734 735 rcu_read_lock(); 736 for (i = 0; i < conf->raid_disks * 2; i++) { 737 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 738 if (rdev && !test_bit(Faulty, &rdev->flags)) { 739 struct request_queue *q = bdev_get_queue(rdev->bdev); 740 741 BUG_ON(!q); 742 743 /* Note the '|| 1' - when read_balance prefers 744 * non-congested targets, it can be removed 745 */ 746 if ((bits & (1 << WB_async_congested)) || 1) 747 ret |= bdi_congested(&q->backing_dev_info, bits); 748 else 749 ret &= bdi_congested(&q->backing_dev_info, bits); 750 } 751 } 752 rcu_read_unlock(); 753 return ret; 754 } 755 756 static void flush_pending_writes(struct r1conf *conf) 757 { 758 /* Any writes that have been queued but are awaiting 759 * bitmap updates get flushed here. 760 */ 761 spin_lock_irq(&conf->device_lock); 762 763 if (conf->pending_bio_list.head) { 764 struct bio *bio; 765 bio = bio_list_get(&conf->pending_bio_list); 766 conf->pending_count = 0; 767 spin_unlock_irq(&conf->device_lock); 768 /* flush any pending bitmap writes to 769 * disk before proceeding w/ I/O */ 770 bitmap_unplug(conf->mddev->bitmap); 771 wake_up(&conf->wait_barrier); 772 773 while (bio) { /* submit pending writes */ 774 struct bio *next = bio->bi_next; 775 struct md_rdev *rdev = (void*)bio->bi_bdev; 776 bio->bi_next = NULL; 777 bio->bi_bdev = rdev->bdev; 778 if (test_bit(Faulty, &rdev->flags)) { 779 bio->bi_error = -EIO; 780 bio_endio(bio); 781 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) && 782 !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) 783 /* Just ignore it */ 784 bio_endio(bio); 785 else 786 generic_make_request(bio); 787 bio = next; 788 } 789 } else 790 spin_unlock_irq(&conf->device_lock); 791 } 792 793 /* Barriers.... 794 * Sometimes we need to suspend IO while we do something else, 795 * either some resync/recovery, or reconfigure the array. 796 * To do this we raise a 'barrier'. 797 * The 'barrier' is a counter that can be raised multiple times 798 * to count how many activities are happening which preclude 799 * normal IO. 800 * We can only raise the barrier if there is no pending IO. 801 * i.e. if nr_pending == 0. 802 * We choose only to raise the barrier if no-one is waiting for the 803 * barrier to go down. This means that as soon as an IO request 804 * is ready, no other operations which require a barrier will start 805 * until the IO request has had a chance. 806 * 807 * So: regular IO calls 'wait_barrier'. When that returns there 808 * is no backgroup IO happening, It must arrange to call 809 * allow_barrier when it has finished its IO. 810 * backgroup IO calls must call raise_barrier. Once that returns 811 * there is no normal IO happeing. It must arrange to call 812 * lower_barrier when the particular background IO completes. 813 */ 814 static void raise_barrier(struct r1conf *conf, sector_t sector_nr) 815 { 816 spin_lock_irq(&conf->resync_lock); 817 818 /* Wait until no block IO is waiting */ 819 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, 820 conf->resync_lock); 821 822 /* block any new IO from starting */ 823 conf->barrier++; 824 conf->next_resync = sector_nr; 825 826 /* For these conditions we must wait: 827 * A: while the array is in frozen state 828 * B: while barrier >= RESYNC_DEPTH, meaning resync reach 829 * the max count which allowed. 830 * C: next_resync + RESYNC_SECTORS > start_next_window, meaning 831 * next resync will reach to the window which normal bios are 832 * handling. 833 * D: while there are any active requests in the current window. 834 */ 835 wait_event_lock_irq(conf->wait_barrier, 836 !conf->array_frozen && 837 conf->barrier < RESYNC_DEPTH && 838 conf->current_window_requests == 0 && 839 (conf->start_next_window >= 840 conf->next_resync + RESYNC_SECTORS), 841 conf->resync_lock); 842 843 conf->nr_pending++; 844 spin_unlock_irq(&conf->resync_lock); 845 } 846 847 static void lower_barrier(struct r1conf *conf) 848 { 849 unsigned long flags; 850 BUG_ON(conf->barrier <= 0); 851 spin_lock_irqsave(&conf->resync_lock, flags); 852 conf->barrier--; 853 conf->nr_pending--; 854 spin_unlock_irqrestore(&conf->resync_lock, flags); 855 wake_up(&conf->wait_barrier); 856 } 857 858 static bool need_to_wait_for_sync(struct r1conf *conf, struct bio *bio) 859 { 860 bool wait = false; 861 862 if (conf->array_frozen || !bio) 863 wait = true; 864 else if (conf->barrier && bio_data_dir(bio) == WRITE) { 865 if ((conf->mddev->curr_resync_completed 866 >= bio_end_sector(bio)) || 867 (conf->start_next_window + NEXT_NORMALIO_DISTANCE 868 <= bio->bi_iter.bi_sector)) 869 wait = false; 870 else 871 wait = true; 872 } 873 874 return wait; 875 } 876 877 static sector_t wait_barrier(struct r1conf *conf, struct bio *bio) 878 { 879 sector_t sector = 0; 880 881 spin_lock_irq(&conf->resync_lock); 882 if (need_to_wait_for_sync(conf, bio)) { 883 conf->nr_waiting++; 884 /* Wait for the barrier to drop. 885 * However if there are already pending 886 * requests (preventing the barrier from 887 * rising completely), and the 888 * per-process bio queue isn't empty, 889 * then don't wait, as we need to empty 890 * that queue to allow conf->start_next_window 891 * to increase. 892 */ 893 raid1_log(conf->mddev, "wait barrier"); 894 wait_event_lock_irq(conf->wait_barrier, 895 !conf->array_frozen && 896 (!conf->barrier || 897 ((conf->start_next_window < 898 conf->next_resync + RESYNC_SECTORS) && 899 current->bio_list && 900 !bio_list_empty(current->bio_list))), 901 conf->resync_lock); 902 conf->nr_waiting--; 903 } 904 905 if (bio && bio_data_dir(bio) == WRITE) { 906 if (bio->bi_iter.bi_sector >= conf->next_resync) { 907 if (conf->start_next_window == MaxSector) 908 conf->start_next_window = 909 conf->next_resync + 910 NEXT_NORMALIO_DISTANCE; 911 912 if ((conf->start_next_window + NEXT_NORMALIO_DISTANCE) 913 <= bio->bi_iter.bi_sector) 914 conf->next_window_requests++; 915 else 916 conf->current_window_requests++; 917 sector = conf->start_next_window; 918 } 919 } 920 921 conf->nr_pending++; 922 spin_unlock_irq(&conf->resync_lock); 923 return sector; 924 } 925 926 static void allow_barrier(struct r1conf *conf, sector_t start_next_window, 927 sector_t bi_sector) 928 { 929 unsigned long flags; 930 931 spin_lock_irqsave(&conf->resync_lock, flags); 932 conf->nr_pending--; 933 if (start_next_window) { 934 if (start_next_window == conf->start_next_window) { 935 if (conf->start_next_window + NEXT_NORMALIO_DISTANCE 936 <= bi_sector) 937 conf->next_window_requests--; 938 else 939 conf->current_window_requests--; 940 } else 941 conf->current_window_requests--; 942 943 if (!conf->current_window_requests) { 944 if (conf->next_window_requests) { 945 conf->current_window_requests = 946 conf->next_window_requests; 947 conf->next_window_requests = 0; 948 conf->start_next_window += 949 NEXT_NORMALIO_DISTANCE; 950 } else 951 conf->start_next_window = MaxSector; 952 } 953 } 954 spin_unlock_irqrestore(&conf->resync_lock, flags); 955 wake_up(&conf->wait_barrier); 956 } 957 958 static void freeze_array(struct r1conf *conf, int extra) 959 { 960 /* stop syncio and normal IO and wait for everything to 961 * go quite. 962 * We wait until nr_pending match nr_queued+extra 963 * This is called in the context of one normal IO request 964 * that has failed. Thus any sync request that might be pending 965 * will be blocked by nr_pending, and we need to wait for 966 * pending IO requests to complete or be queued for re-try. 967 * Thus the number queued (nr_queued) plus this request (extra) 968 * must match the number of pending IOs (nr_pending) before 969 * we continue. 970 */ 971 spin_lock_irq(&conf->resync_lock); 972 conf->array_frozen = 1; 973 raid1_log(conf->mddev, "wait freeze"); 974 wait_event_lock_irq_cmd(conf->wait_barrier, 975 conf->nr_pending == conf->nr_queued+extra, 976 conf->resync_lock, 977 flush_pending_writes(conf)); 978 spin_unlock_irq(&conf->resync_lock); 979 } 980 static void unfreeze_array(struct r1conf *conf) 981 { 982 /* reverse the effect of the freeze */ 983 spin_lock_irq(&conf->resync_lock); 984 conf->array_frozen = 0; 985 wake_up(&conf->wait_barrier); 986 spin_unlock_irq(&conf->resync_lock); 987 } 988 989 /* duplicate the data pages for behind I/O 990 */ 991 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio) 992 { 993 int i; 994 struct bio_vec *bvec; 995 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), 996 GFP_NOIO); 997 if (unlikely(!bvecs)) 998 return; 999 1000 bio_for_each_segment_all(bvec, bio, i) { 1001 bvecs[i] = *bvec; 1002 bvecs[i].bv_page = alloc_page(GFP_NOIO); 1003 if (unlikely(!bvecs[i].bv_page)) 1004 goto do_sync_io; 1005 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset, 1006 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); 1007 kunmap(bvecs[i].bv_page); 1008 kunmap(bvec->bv_page); 1009 } 1010 r1_bio->behind_bvecs = bvecs; 1011 r1_bio->behind_page_count = bio->bi_vcnt; 1012 set_bit(R1BIO_BehindIO, &r1_bio->state); 1013 return; 1014 1015 do_sync_io: 1016 for (i = 0; i < bio->bi_vcnt; i++) 1017 if (bvecs[i].bv_page) 1018 put_page(bvecs[i].bv_page); 1019 kfree(bvecs); 1020 pr_debug("%dB behind alloc failed, doing sync I/O\n", 1021 bio->bi_iter.bi_size); 1022 } 1023 1024 struct raid1_plug_cb { 1025 struct blk_plug_cb cb; 1026 struct bio_list pending; 1027 int pending_cnt; 1028 }; 1029 1030 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule) 1031 { 1032 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb, 1033 cb); 1034 struct mddev *mddev = plug->cb.data; 1035 struct r1conf *conf = mddev->private; 1036 struct bio *bio; 1037 1038 if (from_schedule || current->bio_list) { 1039 spin_lock_irq(&conf->device_lock); 1040 bio_list_merge(&conf->pending_bio_list, &plug->pending); 1041 conf->pending_count += plug->pending_cnt; 1042 spin_unlock_irq(&conf->device_lock); 1043 wake_up(&conf->wait_barrier); 1044 md_wakeup_thread(mddev->thread); 1045 kfree(plug); 1046 return; 1047 } 1048 1049 /* we aren't scheduling, so we can do the write-out directly. */ 1050 bio = bio_list_get(&plug->pending); 1051 bitmap_unplug(mddev->bitmap); 1052 wake_up(&conf->wait_barrier); 1053 1054 while (bio) { /* submit pending writes */ 1055 struct bio *next = bio->bi_next; 1056 struct md_rdev *rdev = (void*)bio->bi_bdev; 1057 bio->bi_next = NULL; 1058 bio->bi_bdev = rdev->bdev; 1059 if (test_bit(Faulty, &rdev->flags)) { 1060 bio->bi_error = -EIO; 1061 bio_endio(bio); 1062 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) && 1063 !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) 1064 /* Just ignore it */ 1065 bio_endio(bio); 1066 else 1067 generic_make_request(bio); 1068 bio = next; 1069 } 1070 kfree(plug); 1071 } 1072 1073 static void raid1_read_request(struct mddev *mddev, struct bio *bio, 1074 struct r1bio *r1_bio) 1075 { 1076 struct r1conf *conf = mddev->private; 1077 struct raid1_info *mirror; 1078 struct bio *read_bio; 1079 struct bitmap *bitmap = mddev->bitmap; 1080 const int op = bio_op(bio); 1081 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC); 1082 int sectors_handled; 1083 int max_sectors; 1084 int rdisk; 1085 1086 wait_barrier(conf, bio); 1087 1088 read_again: 1089 rdisk = read_balance(conf, r1_bio, &max_sectors); 1090 1091 if (rdisk < 0) { 1092 /* couldn't find anywhere to read from */ 1093 raid_end_bio_io(r1_bio); 1094 return; 1095 } 1096 mirror = conf->mirrors + rdisk; 1097 1098 if (test_bit(WriteMostly, &mirror->rdev->flags) && 1099 bitmap) { 1100 /* 1101 * Reading from a write-mostly device must take care not to 1102 * over-take any writes that are 'behind' 1103 */ 1104 raid1_log(mddev, "wait behind writes"); 1105 wait_event(bitmap->behind_wait, 1106 atomic_read(&bitmap->behind_writes) == 0); 1107 } 1108 r1_bio->read_disk = rdisk; 1109 r1_bio->start_next_window = 0; 1110 1111 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); 1112 bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector, 1113 max_sectors); 1114 1115 r1_bio->bios[rdisk] = read_bio; 1116 1117 read_bio->bi_iter.bi_sector = r1_bio->sector + 1118 mirror->rdev->data_offset; 1119 read_bio->bi_bdev = mirror->rdev->bdev; 1120 read_bio->bi_end_io = raid1_end_read_request; 1121 bio_set_op_attrs(read_bio, op, do_sync); 1122 if (test_bit(FailFast, &mirror->rdev->flags) && 1123 test_bit(R1BIO_FailFast, &r1_bio->state)) 1124 read_bio->bi_opf |= MD_FAILFAST; 1125 read_bio->bi_private = r1_bio; 1126 1127 if (mddev->gendisk) 1128 trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev), 1129 read_bio, disk_devt(mddev->gendisk), 1130 r1_bio->sector); 1131 1132 if (max_sectors < r1_bio->sectors) { 1133 /* 1134 * could not read all from this device, so we will need another 1135 * r1_bio. 1136 */ 1137 sectors_handled = (r1_bio->sector + max_sectors 1138 - bio->bi_iter.bi_sector); 1139 r1_bio->sectors = max_sectors; 1140 spin_lock_irq(&conf->device_lock); 1141 if (bio->bi_phys_segments == 0) 1142 bio->bi_phys_segments = 2; 1143 else 1144 bio->bi_phys_segments++; 1145 spin_unlock_irq(&conf->device_lock); 1146 1147 /* 1148 * Cannot call generic_make_request directly as that will be 1149 * queued in __make_request and subsequent mempool_alloc might 1150 * block waiting for it. So hand bio over to raid1d. 1151 */ 1152 reschedule_retry(r1_bio); 1153 1154 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1155 1156 r1_bio->master_bio = bio; 1157 r1_bio->sectors = bio_sectors(bio) - sectors_handled; 1158 r1_bio->state = 0; 1159 r1_bio->mddev = mddev; 1160 r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled; 1161 goto read_again; 1162 } else 1163 generic_make_request(read_bio); 1164 } 1165 1166 static void raid1_write_request(struct mddev *mddev, struct bio *bio, 1167 struct r1bio *r1_bio) 1168 { 1169 struct r1conf *conf = mddev->private; 1170 int i, disks; 1171 struct bitmap *bitmap = mddev->bitmap; 1172 unsigned long flags; 1173 const int op = bio_op(bio); 1174 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC); 1175 const unsigned long do_flush_fua = (bio->bi_opf & 1176 (REQ_PREFLUSH | REQ_FUA)); 1177 struct md_rdev *blocked_rdev; 1178 struct blk_plug_cb *cb; 1179 struct raid1_plug_cb *plug = NULL; 1180 int first_clone; 1181 int sectors_handled; 1182 int max_sectors; 1183 sector_t start_next_window; 1184 1185 /* 1186 * Register the new request and wait if the reconstruction 1187 * thread has put up a bar for new requests. 1188 * Continue immediately if no resync is active currently. 1189 */ 1190 1191 md_write_start(mddev, bio); /* wait on superblock update early */ 1192 1193 if ((bio_end_sector(bio) > mddev->suspend_lo && 1194 bio->bi_iter.bi_sector < mddev->suspend_hi) || 1195 (mddev_is_clustered(mddev) && 1196 md_cluster_ops->area_resyncing(mddev, WRITE, 1197 bio->bi_iter.bi_sector, bio_end_sector(bio)))) { 1198 1199 /* 1200 * As the suspend_* range is controlled by userspace, we want 1201 * an interruptible wait. 1202 */ 1203 DEFINE_WAIT(w); 1204 for (;;) { 1205 flush_signals(current); 1206 prepare_to_wait(&conf->wait_barrier, 1207 &w, TASK_INTERRUPTIBLE); 1208 if (bio_end_sector(bio) <= mddev->suspend_lo || 1209 bio->bi_iter.bi_sector >= mddev->suspend_hi || 1210 (mddev_is_clustered(mddev) && 1211 !md_cluster_ops->area_resyncing(mddev, WRITE, 1212 bio->bi_iter.bi_sector, 1213 bio_end_sector(bio)))) 1214 break; 1215 schedule(); 1216 } 1217 finish_wait(&conf->wait_barrier, &w); 1218 } 1219 start_next_window = wait_barrier(conf, bio); 1220 1221 if (conf->pending_count >= max_queued_requests) { 1222 md_wakeup_thread(mddev->thread); 1223 raid1_log(mddev, "wait queued"); 1224 wait_event(conf->wait_barrier, 1225 conf->pending_count < max_queued_requests); 1226 } 1227 /* first select target devices under rcu_lock and 1228 * inc refcount on their rdev. Record them by setting 1229 * bios[x] to bio 1230 * If there are known/acknowledged bad blocks on any device on 1231 * which we have seen a write error, we want to avoid writing those 1232 * blocks. 1233 * This potentially requires several writes to write around 1234 * the bad blocks. Each set of writes gets it's own r1bio 1235 * with a set of bios attached. 1236 */ 1237 1238 disks = conf->raid_disks * 2; 1239 retry_write: 1240 r1_bio->start_next_window = start_next_window; 1241 blocked_rdev = NULL; 1242 rcu_read_lock(); 1243 max_sectors = r1_bio->sectors; 1244 for (i = 0; i < disks; i++) { 1245 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1246 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { 1247 atomic_inc(&rdev->nr_pending); 1248 blocked_rdev = rdev; 1249 break; 1250 } 1251 r1_bio->bios[i] = NULL; 1252 if (!rdev || test_bit(Faulty, &rdev->flags)) { 1253 if (i < conf->raid_disks) 1254 set_bit(R1BIO_Degraded, &r1_bio->state); 1255 continue; 1256 } 1257 1258 atomic_inc(&rdev->nr_pending); 1259 if (test_bit(WriteErrorSeen, &rdev->flags)) { 1260 sector_t first_bad; 1261 int bad_sectors; 1262 int is_bad; 1263 1264 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors, 1265 &first_bad, &bad_sectors); 1266 if (is_bad < 0) { 1267 /* mustn't write here until the bad block is 1268 * acknowledged*/ 1269 set_bit(BlockedBadBlocks, &rdev->flags); 1270 blocked_rdev = rdev; 1271 break; 1272 } 1273 if (is_bad && first_bad <= r1_bio->sector) { 1274 /* Cannot write here at all */ 1275 bad_sectors -= (r1_bio->sector - first_bad); 1276 if (bad_sectors < max_sectors) 1277 /* mustn't write more than bad_sectors 1278 * to other devices yet 1279 */ 1280 max_sectors = bad_sectors; 1281 rdev_dec_pending(rdev, mddev); 1282 /* We don't set R1BIO_Degraded as that 1283 * only applies if the disk is 1284 * missing, so it might be re-added, 1285 * and we want to know to recover this 1286 * chunk. 1287 * In this case the device is here, 1288 * and the fact that this chunk is not 1289 * in-sync is recorded in the bad 1290 * block log 1291 */ 1292 continue; 1293 } 1294 if (is_bad) { 1295 int good_sectors = first_bad - r1_bio->sector; 1296 if (good_sectors < max_sectors) 1297 max_sectors = good_sectors; 1298 } 1299 } 1300 r1_bio->bios[i] = bio; 1301 } 1302 rcu_read_unlock(); 1303 1304 if (unlikely(blocked_rdev)) { 1305 /* Wait for this device to become unblocked */ 1306 int j; 1307 sector_t old = start_next_window; 1308 1309 for (j = 0; j < i; j++) 1310 if (r1_bio->bios[j]) 1311 rdev_dec_pending(conf->mirrors[j].rdev, mddev); 1312 r1_bio->state = 0; 1313 allow_barrier(conf, start_next_window, bio->bi_iter.bi_sector); 1314 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk); 1315 md_wait_for_blocked_rdev(blocked_rdev, mddev); 1316 start_next_window = wait_barrier(conf, bio); 1317 /* 1318 * We must make sure the multi r1bios of bio have 1319 * the same value of bi_phys_segments 1320 */ 1321 if (bio->bi_phys_segments && old && 1322 old != start_next_window) 1323 /* Wait for the former r1bio(s) to complete */ 1324 wait_event(conf->wait_barrier, 1325 bio->bi_phys_segments == 1); 1326 goto retry_write; 1327 } 1328 1329 if (max_sectors < r1_bio->sectors) { 1330 /* We are splitting this write into multiple parts, so 1331 * we need to prepare for allocating another r1_bio. 1332 */ 1333 r1_bio->sectors = max_sectors; 1334 spin_lock_irq(&conf->device_lock); 1335 if (bio->bi_phys_segments == 0) 1336 bio->bi_phys_segments = 2; 1337 else 1338 bio->bi_phys_segments++; 1339 spin_unlock_irq(&conf->device_lock); 1340 } 1341 sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector; 1342 1343 atomic_set(&r1_bio->remaining, 1); 1344 atomic_set(&r1_bio->behind_remaining, 0); 1345 1346 first_clone = 1; 1347 for (i = 0; i < disks; i++) { 1348 struct bio *mbio; 1349 if (!r1_bio->bios[i]) 1350 continue; 1351 1352 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); 1353 bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector, 1354 max_sectors); 1355 1356 if (first_clone) { 1357 /* do behind I/O ? 1358 * Not if there are too many, or cannot 1359 * allocate memory, or a reader on WriteMostly 1360 * is waiting for behind writes to flush */ 1361 if (bitmap && 1362 (atomic_read(&bitmap->behind_writes) 1363 < mddev->bitmap_info.max_write_behind) && 1364 !waitqueue_active(&bitmap->behind_wait)) 1365 alloc_behind_pages(mbio, r1_bio); 1366 1367 bitmap_startwrite(bitmap, r1_bio->sector, 1368 r1_bio->sectors, 1369 test_bit(R1BIO_BehindIO, 1370 &r1_bio->state)); 1371 first_clone = 0; 1372 } 1373 if (r1_bio->behind_bvecs) { 1374 struct bio_vec *bvec; 1375 int j; 1376 1377 /* 1378 * We trimmed the bio, so _all is legit 1379 */ 1380 bio_for_each_segment_all(bvec, mbio, j) 1381 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page; 1382 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) 1383 atomic_inc(&r1_bio->behind_remaining); 1384 } 1385 1386 r1_bio->bios[i] = mbio; 1387 1388 mbio->bi_iter.bi_sector = (r1_bio->sector + 1389 conf->mirrors[i].rdev->data_offset); 1390 mbio->bi_bdev = conf->mirrors[i].rdev->bdev; 1391 mbio->bi_end_io = raid1_end_write_request; 1392 bio_set_op_attrs(mbio, op, do_flush_fua | do_sync); 1393 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) && 1394 !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) && 1395 conf->raid_disks - mddev->degraded > 1) 1396 mbio->bi_opf |= MD_FAILFAST; 1397 mbio->bi_private = r1_bio; 1398 1399 atomic_inc(&r1_bio->remaining); 1400 1401 if (mddev->gendisk) 1402 trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev), 1403 mbio, disk_devt(mddev->gendisk), 1404 r1_bio->sector); 1405 /* flush_pending_writes() needs access to the rdev so...*/ 1406 mbio->bi_bdev = (void*)conf->mirrors[i].rdev; 1407 1408 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug)); 1409 if (cb) 1410 plug = container_of(cb, struct raid1_plug_cb, cb); 1411 else 1412 plug = NULL; 1413 spin_lock_irqsave(&conf->device_lock, flags); 1414 if (plug) { 1415 bio_list_add(&plug->pending, mbio); 1416 plug->pending_cnt++; 1417 } else { 1418 bio_list_add(&conf->pending_bio_list, mbio); 1419 conf->pending_count++; 1420 } 1421 spin_unlock_irqrestore(&conf->device_lock, flags); 1422 if (!plug) 1423 md_wakeup_thread(mddev->thread); 1424 } 1425 /* Mustn't call r1_bio_write_done before this next test, 1426 * as it could result in the bio being freed. 1427 */ 1428 if (sectors_handled < bio_sectors(bio)) { 1429 r1_bio_write_done(r1_bio); 1430 /* We need another r1_bio. It has already been counted 1431 * in bio->bi_phys_segments 1432 */ 1433 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1434 r1_bio->master_bio = bio; 1435 r1_bio->sectors = bio_sectors(bio) - sectors_handled; 1436 r1_bio->state = 0; 1437 r1_bio->mddev = mddev; 1438 r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled; 1439 goto retry_write; 1440 } 1441 1442 r1_bio_write_done(r1_bio); 1443 1444 /* In case raid1d snuck in to freeze_array */ 1445 wake_up(&conf->wait_barrier); 1446 } 1447 1448 static void raid1_make_request(struct mddev *mddev, struct bio *bio) 1449 { 1450 struct r1conf *conf = mddev->private; 1451 struct r1bio *r1_bio; 1452 1453 /* 1454 * make_request() can abort the operation when read-ahead is being 1455 * used and no empty request is available. 1456 * 1457 */ 1458 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1459 1460 r1_bio->master_bio = bio; 1461 r1_bio->sectors = bio_sectors(bio); 1462 r1_bio->state = 0; 1463 r1_bio->mddev = mddev; 1464 r1_bio->sector = bio->bi_iter.bi_sector; 1465 1466 /* 1467 * We might need to issue multiple reads to different devices if there 1468 * are bad blocks around, so we keep track of the number of reads in 1469 * bio->bi_phys_segments. If this is 0, there is only one r1_bio and 1470 * no locking will be needed when requests complete. If it is 1471 * non-zero, then it is the number of not-completed requests. 1472 */ 1473 bio->bi_phys_segments = 0; 1474 bio_clear_flag(bio, BIO_SEG_VALID); 1475 1476 if (bio_data_dir(bio) == READ) 1477 raid1_read_request(mddev, bio, r1_bio); 1478 else 1479 raid1_write_request(mddev, bio, r1_bio); 1480 } 1481 1482 static void raid1_status(struct seq_file *seq, struct mddev *mddev) 1483 { 1484 struct r1conf *conf = mddev->private; 1485 int i; 1486 1487 seq_printf(seq, " [%d/%d] [", conf->raid_disks, 1488 conf->raid_disks - mddev->degraded); 1489 rcu_read_lock(); 1490 for (i = 0; i < conf->raid_disks; i++) { 1491 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1492 seq_printf(seq, "%s", 1493 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); 1494 } 1495 rcu_read_unlock(); 1496 seq_printf(seq, "]"); 1497 } 1498 1499 static void raid1_error(struct mddev *mddev, struct md_rdev *rdev) 1500 { 1501 char b[BDEVNAME_SIZE]; 1502 struct r1conf *conf = mddev->private; 1503 unsigned long flags; 1504 1505 /* 1506 * If it is not operational, then we have already marked it as dead 1507 * else if it is the last working disks, ignore the error, let the 1508 * next level up know. 1509 * else mark the drive as failed 1510 */ 1511 spin_lock_irqsave(&conf->device_lock, flags); 1512 if (test_bit(In_sync, &rdev->flags) 1513 && (conf->raid_disks - mddev->degraded) == 1) { 1514 /* 1515 * Don't fail the drive, act as though we were just a 1516 * normal single drive. 1517 * However don't try a recovery from this drive as 1518 * it is very likely to fail. 1519 */ 1520 conf->recovery_disabled = mddev->recovery_disabled; 1521 spin_unlock_irqrestore(&conf->device_lock, flags); 1522 return; 1523 } 1524 set_bit(Blocked, &rdev->flags); 1525 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1526 mddev->degraded++; 1527 set_bit(Faulty, &rdev->flags); 1528 } else 1529 set_bit(Faulty, &rdev->flags); 1530 spin_unlock_irqrestore(&conf->device_lock, flags); 1531 /* 1532 * if recovery is running, make sure it aborts. 1533 */ 1534 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1535 set_mask_bits(&mddev->sb_flags, 0, 1536 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); 1537 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n" 1538 "md/raid1:%s: Operation continuing on %d devices.\n", 1539 mdname(mddev), bdevname(rdev->bdev, b), 1540 mdname(mddev), conf->raid_disks - mddev->degraded); 1541 } 1542 1543 static void print_conf(struct r1conf *conf) 1544 { 1545 int i; 1546 1547 pr_debug("RAID1 conf printout:\n"); 1548 if (!conf) { 1549 pr_debug("(!conf)\n"); 1550 return; 1551 } 1552 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, 1553 conf->raid_disks); 1554 1555 rcu_read_lock(); 1556 for (i = 0; i < conf->raid_disks; i++) { 1557 char b[BDEVNAME_SIZE]; 1558 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1559 if (rdev) 1560 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n", 1561 i, !test_bit(In_sync, &rdev->flags), 1562 !test_bit(Faulty, &rdev->flags), 1563 bdevname(rdev->bdev,b)); 1564 } 1565 rcu_read_unlock(); 1566 } 1567 1568 static void close_sync(struct r1conf *conf) 1569 { 1570 wait_barrier(conf, NULL); 1571 allow_barrier(conf, 0, 0); 1572 1573 mempool_destroy(conf->r1buf_pool); 1574 conf->r1buf_pool = NULL; 1575 1576 spin_lock_irq(&conf->resync_lock); 1577 conf->next_resync = MaxSector - 2 * NEXT_NORMALIO_DISTANCE; 1578 conf->start_next_window = MaxSector; 1579 conf->current_window_requests += 1580 conf->next_window_requests; 1581 conf->next_window_requests = 0; 1582 spin_unlock_irq(&conf->resync_lock); 1583 } 1584 1585 static int raid1_spare_active(struct mddev *mddev) 1586 { 1587 int i; 1588 struct r1conf *conf = mddev->private; 1589 int count = 0; 1590 unsigned long flags; 1591 1592 /* 1593 * Find all failed disks within the RAID1 configuration 1594 * and mark them readable. 1595 * Called under mddev lock, so rcu protection not needed. 1596 * device_lock used to avoid races with raid1_end_read_request 1597 * which expects 'In_sync' flags and ->degraded to be consistent. 1598 */ 1599 spin_lock_irqsave(&conf->device_lock, flags); 1600 for (i = 0; i < conf->raid_disks; i++) { 1601 struct md_rdev *rdev = conf->mirrors[i].rdev; 1602 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev; 1603 if (repl 1604 && !test_bit(Candidate, &repl->flags) 1605 && repl->recovery_offset == MaxSector 1606 && !test_bit(Faulty, &repl->flags) 1607 && !test_and_set_bit(In_sync, &repl->flags)) { 1608 /* replacement has just become active */ 1609 if (!rdev || 1610 !test_and_clear_bit(In_sync, &rdev->flags)) 1611 count++; 1612 if (rdev) { 1613 /* Replaced device not technically 1614 * faulty, but we need to be sure 1615 * it gets removed and never re-added 1616 */ 1617 set_bit(Faulty, &rdev->flags); 1618 sysfs_notify_dirent_safe( 1619 rdev->sysfs_state); 1620 } 1621 } 1622 if (rdev 1623 && rdev->recovery_offset == MaxSector 1624 && !test_bit(Faulty, &rdev->flags) 1625 && !test_and_set_bit(In_sync, &rdev->flags)) { 1626 count++; 1627 sysfs_notify_dirent_safe(rdev->sysfs_state); 1628 } 1629 } 1630 mddev->degraded -= count; 1631 spin_unlock_irqrestore(&conf->device_lock, flags); 1632 1633 print_conf(conf); 1634 return count; 1635 } 1636 1637 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev) 1638 { 1639 struct r1conf *conf = mddev->private; 1640 int err = -EEXIST; 1641 int mirror = 0; 1642 struct raid1_info *p; 1643 int first = 0; 1644 int last = conf->raid_disks - 1; 1645 1646 if (mddev->recovery_disabled == conf->recovery_disabled) 1647 return -EBUSY; 1648 1649 if (md_integrity_add_rdev(rdev, mddev)) 1650 return -ENXIO; 1651 1652 if (rdev->raid_disk >= 0) 1653 first = last = rdev->raid_disk; 1654 1655 /* 1656 * find the disk ... but prefer rdev->saved_raid_disk 1657 * if possible. 1658 */ 1659 if (rdev->saved_raid_disk >= 0 && 1660 rdev->saved_raid_disk >= first && 1661 conf->mirrors[rdev->saved_raid_disk].rdev == NULL) 1662 first = last = rdev->saved_raid_disk; 1663 1664 for (mirror = first; mirror <= last; mirror++) { 1665 p = conf->mirrors+mirror; 1666 if (!p->rdev) { 1667 1668 if (mddev->gendisk) 1669 disk_stack_limits(mddev->gendisk, rdev->bdev, 1670 rdev->data_offset << 9); 1671 1672 p->head_position = 0; 1673 rdev->raid_disk = mirror; 1674 err = 0; 1675 /* As all devices are equivalent, we don't need a full recovery 1676 * if this was recently any drive of the array 1677 */ 1678 if (rdev->saved_raid_disk < 0) 1679 conf->fullsync = 1; 1680 rcu_assign_pointer(p->rdev, rdev); 1681 break; 1682 } 1683 if (test_bit(WantReplacement, &p->rdev->flags) && 1684 p[conf->raid_disks].rdev == NULL) { 1685 /* Add this device as a replacement */ 1686 clear_bit(In_sync, &rdev->flags); 1687 set_bit(Replacement, &rdev->flags); 1688 rdev->raid_disk = mirror; 1689 err = 0; 1690 conf->fullsync = 1; 1691 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev); 1692 break; 1693 } 1694 } 1695 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) 1696 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 1697 print_conf(conf); 1698 return err; 1699 } 1700 1701 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev) 1702 { 1703 struct r1conf *conf = mddev->private; 1704 int err = 0; 1705 int number = rdev->raid_disk; 1706 struct raid1_info *p = conf->mirrors + number; 1707 1708 if (rdev != p->rdev) 1709 p = conf->mirrors + conf->raid_disks + number; 1710 1711 print_conf(conf); 1712 if (rdev == p->rdev) { 1713 if (test_bit(In_sync, &rdev->flags) || 1714 atomic_read(&rdev->nr_pending)) { 1715 err = -EBUSY; 1716 goto abort; 1717 } 1718 /* Only remove non-faulty devices if recovery 1719 * is not possible. 1720 */ 1721 if (!test_bit(Faulty, &rdev->flags) && 1722 mddev->recovery_disabled != conf->recovery_disabled && 1723 mddev->degraded < conf->raid_disks) { 1724 err = -EBUSY; 1725 goto abort; 1726 } 1727 p->rdev = NULL; 1728 if (!test_bit(RemoveSynchronized, &rdev->flags)) { 1729 synchronize_rcu(); 1730 if (atomic_read(&rdev->nr_pending)) { 1731 /* lost the race, try later */ 1732 err = -EBUSY; 1733 p->rdev = rdev; 1734 goto abort; 1735 } 1736 } 1737 if (conf->mirrors[conf->raid_disks + number].rdev) { 1738 /* We just removed a device that is being replaced. 1739 * Move down the replacement. We drain all IO before 1740 * doing this to avoid confusion. 1741 */ 1742 struct md_rdev *repl = 1743 conf->mirrors[conf->raid_disks + number].rdev; 1744 freeze_array(conf, 0); 1745 clear_bit(Replacement, &repl->flags); 1746 p->rdev = repl; 1747 conf->mirrors[conf->raid_disks + number].rdev = NULL; 1748 unfreeze_array(conf); 1749 clear_bit(WantReplacement, &rdev->flags); 1750 } else 1751 clear_bit(WantReplacement, &rdev->flags); 1752 err = md_integrity_register(mddev); 1753 } 1754 abort: 1755 1756 print_conf(conf); 1757 return err; 1758 } 1759 1760 static void end_sync_read(struct bio *bio) 1761 { 1762 struct r1bio *r1_bio = bio->bi_private; 1763 1764 update_head_pos(r1_bio->read_disk, r1_bio); 1765 1766 /* 1767 * we have read a block, now it needs to be re-written, 1768 * or re-read if the read failed. 1769 * We don't do much here, just schedule handling by raid1d 1770 */ 1771 if (!bio->bi_error) 1772 set_bit(R1BIO_Uptodate, &r1_bio->state); 1773 1774 if (atomic_dec_and_test(&r1_bio->remaining)) 1775 reschedule_retry(r1_bio); 1776 } 1777 1778 static void end_sync_write(struct bio *bio) 1779 { 1780 int uptodate = !bio->bi_error; 1781 struct r1bio *r1_bio = bio->bi_private; 1782 struct mddev *mddev = r1_bio->mddev; 1783 struct r1conf *conf = mddev->private; 1784 sector_t first_bad; 1785 int bad_sectors; 1786 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev; 1787 1788 if (!uptodate) { 1789 sector_t sync_blocks = 0; 1790 sector_t s = r1_bio->sector; 1791 long sectors_to_go = r1_bio->sectors; 1792 /* make sure these bits doesn't get cleared. */ 1793 do { 1794 bitmap_end_sync(mddev->bitmap, s, 1795 &sync_blocks, 1); 1796 s += sync_blocks; 1797 sectors_to_go -= sync_blocks; 1798 } while (sectors_to_go > 0); 1799 set_bit(WriteErrorSeen, &rdev->flags); 1800 if (!test_and_set_bit(WantReplacement, &rdev->flags)) 1801 set_bit(MD_RECOVERY_NEEDED, & 1802 mddev->recovery); 1803 set_bit(R1BIO_WriteError, &r1_bio->state); 1804 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors, 1805 &first_bad, &bad_sectors) && 1806 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev, 1807 r1_bio->sector, 1808 r1_bio->sectors, 1809 &first_bad, &bad_sectors) 1810 ) 1811 set_bit(R1BIO_MadeGood, &r1_bio->state); 1812 1813 if (atomic_dec_and_test(&r1_bio->remaining)) { 1814 int s = r1_bio->sectors; 1815 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 1816 test_bit(R1BIO_WriteError, &r1_bio->state)) 1817 reschedule_retry(r1_bio); 1818 else { 1819 put_buf(r1_bio); 1820 md_done_sync(mddev, s, uptodate); 1821 } 1822 } 1823 } 1824 1825 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector, 1826 int sectors, struct page *page, int rw) 1827 { 1828 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false)) 1829 /* success */ 1830 return 1; 1831 if (rw == WRITE) { 1832 set_bit(WriteErrorSeen, &rdev->flags); 1833 if (!test_and_set_bit(WantReplacement, 1834 &rdev->flags)) 1835 set_bit(MD_RECOVERY_NEEDED, & 1836 rdev->mddev->recovery); 1837 } 1838 /* need to record an error - either for the block or the device */ 1839 if (!rdev_set_badblocks(rdev, sector, sectors, 0)) 1840 md_error(rdev->mddev, rdev); 1841 return 0; 1842 } 1843 1844 static int fix_sync_read_error(struct r1bio *r1_bio) 1845 { 1846 /* Try some synchronous reads of other devices to get 1847 * good data, much like with normal read errors. Only 1848 * read into the pages we already have so we don't 1849 * need to re-issue the read request. 1850 * We don't need to freeze the array, because being in an 1851 * active sync request, there is no normal IO, and 1852 * no overlapping syncs. 1853 * We don't need to check is_badblock() again as we 1854 * made sure that anything with a bad block in range 1855 * will have bi_end_io clear. 1856 */ 1857 struct mddev *mddev = r1_bio->mddev; 1858 struct r1conf *conf = mddev->private; 1859 struct bio *bio = r1_bio->bios[r1_bio->read_disk]; 1860 sector_t sect = r1_bio->sector; 1861 int sectors = r1_bio->sectors; 1862 int idx = 0; 1863 struct md_rdev *rdev; 1864 1865 rdev = conf->mirrors[r1_bio->read_disk].rdev; 1866 if (test_bit(FailFast, &rdev->flags)) { 1867 /* Don't try recovering from here - just fail it 1868 * ... unless it is the last working device of course */ 1869 md_error(mddev, rdev); 1870 if (test_bit(Faulty, &rdev->flags)) 1871 /* Don't try to read from here, but make sure 1872 * put_buf does it's thing 1873 */ 1874 bio->bi_end_io = end_sync_write; 1875 } 1876 1877 while(sectors) { 1878 int s = sectors; 1879 int d = r1_bio->read_disk; 1880 int success = 0; 1881 int start; 1882 1883 if (s > (PAGE_SIZE>>9)) 1884 s = PAGE_SIZE >> 9; 1885 do { 1886 if (r1_bio->bios[d]->bi_end_io == end_sync_read) { 1887 /* No rcu protection needed here devices 1888 * can only be removed when no resync is 1889 * active, and resync is currently active 1890 */ 1891 rdev = conf->mirrors[d].rdev; 1892 if (sync_page_io(rdev, sect, s<<9, 1893 bio->bi_io_vec[idx].bv_page, 1894 REQ_OP_READ, 0, false)) { 1895 success = 1; 1896 break; 1897 } 1898 } 1899 d++; 1900 if (d == conf->raid_disks * 2) 1901 d = 0; 1902 } while (!success && d != r1_bio->read_disk); 1903 1904 if (!success) { 1905 char b[BDEVNAME_SIZE]; 1906 int abort = 0; 1907 /* Cannot read from anywhere, this block is lost. 1908 * Record a bad block on each device. If that doesn't 1909 * work just disable and interrupt the recovery. 1910 * Don't fail devices as that won't really help. 1911 */ 1912 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n", 1913 mdname(mddev), 1914 bdevname(bio->bi_bdev, b), 1915 (unsigned long long)r1_bio->sector); 1916 for (d = 0; d < conf->raid_disks * 2; d++) { 1917 rdev = conf->mirrors[d].rdev; 1918 if (!rdev || test_bit(Faulty, &rdev->flags)) 1919 continue; 1920 if (!rdev_set_badblocks(rdev, sect, s, 0)) 1921 abort = 1; 1922 } 1923 if (abort) { 1924 conf->recovery_disabled = 1925 mddev->recovery_disabled; 1926 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1927 md_done_sync(mddev, r1_bio->sectors, 0); 1928 put_buf(r1_bio); 1929 return 0; 1930 } 1931 /* Try next page */ 1932 sectors -= s; 1933 sect += s; 1934 idx++; 1935 continue; 1936 } 1937 1938 start = d; 1939 /* write it back and re-read */ 1940 while (d != r1_bio->read_disk) { 1941 if (d == 0) 1942 d = conf->raid_disks * 2; 1943 d--; 1944 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1945 continue; 1946 rdev = conf->mirrors[d].rdev; 1947 if (r1_sync_page_io(rdev, sect, s, 1948 bio->bi_io_vec[idx].bv_page, 1949 WRITE) == 0) { 1950 r1_bio->bios[d]->bi_end_io = NULL; 1951 rdev_dec_pending(rdev, mddev); 1952 } 1953 } 1954 d = start; 1955 while (d != r1_bio->read_disk) { 1956 if (d == 0) 1957 d = conf->raid_disks * 2; 1958 d--; 1959 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1960 continue; 1961 rdev = conf->mirrors[d].rdev; 1962 if (r1_sync_page_io(rdev, sect, s, 1963 bio->bi_io_vec[idx].bv_page, 1964 READ) != 0) 1965 atomic_add(s, &rdev->corrected_errors); 1966 } 1967 sectors -= s; 1968 sect += s; 1969 idx ++; 1970 } 1971 set_bit(R1BIO_Uptodate, &r1_bio->state); 1972 bio->bi_error = 0; 1973 return 1; 1974 } 1975 1976 static void process_checks(struct r1bio *r1_bio) 1977 { 1978 /* We have read all readable devices. If we haven't 1979 * got the block, then there is no hope left. 1980 * If we have, then we want to do a comparison 1981 * and skip the write if everything is the same. 1982 * If any blocks failed to read, then we need to 1983 * attempt an over-write 1984 */ 1985 struct mddev *mddev = r1_bio->mddev; 1986 struct r1conf *conf = mddev->private; 1987 int primary; 1988 int i; 1989 int vcnt; 1990 1991 /* Fix variable parts of all bios */ 1992 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); 1993 for (i = 0; i < conf->raid_disks * 2; i++) { 1994 int j; 1995 int size; 1996 int error; 1997 struct bio *b = r1_bio->bios[i]; 1998 if (b->bi_end_io != end_sync_read) 1999 continue; 2000 /* fixup the bio for reuse, but preserve errno */ 2001 error = b->bi_error; 2002 bio_reset(b); 2003 b->bi_error = error; 2004 b->bi_vcnt = vcnt; 2005 b->bi_iter.bi_size = r1_bio->sectors << 9; 2006 b->bi_iter.bi_sector = r1_bio->sector + 2007 conf->mirrors[i].rdev->data_offset; 2008 b->bi_bdev = conf->mirrors[i].rdev->bdev; 2009 b->bi_end_io = end_sync_read; 2010 b->bi_private = r1_bio; 2011 2012 size = b->bi_iter.bi_size; 2013 for (j = 0; j < vcnt ; j++) { 2014 struct bio_vec *bi; 2015 bi = &b->bi_io_vec[j]; 2016 bi->bv_offset = 0; 2017 if (size > PAGE_SIZE) 2018 bi->bv_len = PAGE_SIZE; 2019 else 2020 bi->bv_len = size; 2021 size -= PAGE_SIZE; 2022 } 2023 } 2024 for (primary = 0; primary < conf->raid_disks * 2; primary++) 2025 if (r1_bio->bios[primary]->bi_end_io == end_sync_read && 2026 !r1_bio->bios[primary]->bi_error) { 2027 r1_bio->bios[primary]->bi_end_io = NULL; 2028 rdev_dec_pending(conf->mirrors[primary].rdev, mddev); 2029 break; 2030 } 2031 r1_bio->read_disk = primary; 2032 for (i = 0; i < conf->raid_disks * 2; i++) { 2033 int j; 2034 struct bio *pbio = r1_bio->bios[primary]; 2035 struct bio *sbio = r1_bio->bios[i]; 2036 int error = sbio->bi_error; 2037 2038 if (sbio->bi_end_io != end_sync_read) 2039 continue; 2040 /* Now we can 'fixup' the error value */ 2041 sbio->bi_error = 0; 2042 2043 if (!error) { 2044 for (j = vcnt; j-- ; ) { 2045 struct page *p, *s; 2046 p = pbio->bi_io_vec[j].bv_page; 2047 s = sbio->bi_io_vec[j].bv_page; 2048 if (memcmp(page_address(p), 2049 page_address(s), 2050 sbio->bi_io_vec[j].bv_len)) 2051 break; 2052 } 2053 } else 2054 j = 0; 2055 if (j >= 0) 2056 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches); 2057 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) 2058 && !error)) { 2059 /* No need to write to this device. */ 2060 sbio->bi_end_io = NULL; 2061 rdev_dec_pending(conf->mirrors[i].rdev, mddev); 2062 continue; 2063 } 2064 2065 bio_copy_data(sbio, pbio); 2066 } 2067 } 2068 2069 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) 2070 { 2071 struct r1conf *conf = mddev->private; 2072 int i; 2073 int disks = conf->raid_disks * 2; 2074 struct bio *bio, *wbio; 2075 2076 bio = r1_bio->bios[r1_bio->read_disk]; 2077 2078 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) 2079 /* ouch - failed to read all of that. */ 2080 if (!fix_sync_read_error(r1_bio)) 2081 return; 2082 2083 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 2084 process_checks(r1_bio); 2085 2086 /* 2087 * schedule writes 2088 */ 2089 atomic_set(&r1_bio->remaining, 1); 2090 for (i = 0; i < disks ; i++) { 2091 wbio = r1_bio->bios[i]; 2092 if (wbio->bi_end_io == NULL || 2093 (wbio->bi_end_io == end_sync_read && 2094 (i == r1_bio->read_disk || 2095 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) 2096 continue; 2097 2098 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0); 2099 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags)) 2100 wbio->bi_opf |= MD_FAILFAST; 2101 2102 wbio->bi_end_io = end_sync_write; 2103 atomic_inc(&r1_bio->remaining); 2104 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio)); 2105 2106 generic_make_request(wbio); 2107 } 2108 2109 if (atomic_dec_and_test(&r1_bio->remaining)) { 2110 /* if we're here, all write(s) have completed, so clean up */ 2111 int s = r1_bio->sectors; 2112 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2113 test_bit(R1BIO_WriteError, &r1_bio->state)) 2114 reschedule_retry(r1_bio); 2115 else { 2116 put_buf(r1_bio); 2117 md_done_sync(mddev, s, 1); 2118 } 2119 } 2120 } 2121 2122 /* 2123 * This is a kernel thread which: 2124 * 2125 * 1. Retries failed read operations on working mirrors. 2126 * 2. Updates the raid superblock when problems encounter. 2127 * 3. Performs writes following reads for array synchronising. 2128 */ 2129 2130 static void fix_read_error(struct r1conf *conf, int read_disk, 2131 sector_t sect, int sectors) 2132 { 2133 struct mddev *mddev = conf->mddev; 2134 while(sectors) { 2135 int s = sectors; 2136 int d = read_disk; 2137 int success = 0; 2138 int start; 2139 struct md_rdev *rdev; 2140 2141 if (s > (PAGE_SIZE>>9)) 2142 s = PAGE_SIZE >> 9; 2143 2144 do { 2145 sector_t first_bad; 2146 int bad_sectors; 2147 2148 rcu_read_lock(); 2149 rdev = rcu_dereference(conf->mirrors[d].rdev); 2150 if (rdev && 2151 (test_bit(In_sync, &rdev->flags) || 2152 (!test_bit(Faulty, &rdev->flags) && 2153 rdev->recovery_offset >= sect + s)) && 2154 is_badblock(rdev, sect, s, 2155 &first_bad, &bad_sectors) == 0) { 2156 atomic_inc(&rdev->nr_pending); 2157 rcu_read_unlock(); 2158 if (sync_page_io(rdev, sect, s<<9, 2159 conf->tmppage, REQ_OP_READ, 0, false)) 2160 success = 1; 2161 rdev_dec_pending(rdev, mddev); 2162 if (success) 2163 break; 2164 } else 2165 rcu_read_unlock(); 2166 d++; 2167 if (d == conf->raid_disks * 2) 2168 d = 0; 2169 } while (!success && d != read_disk); 2170 2171 if (!success) { 2172 /* Cannot read from anywhere - mark it bad */ 2173 struct md_rdev *rdev = conf->mirrors[read_disk].rdev; 2174 if (!rdev_set_badblocks(rdev, sect, s, 0)) 2175 md_error(mddev, rdev); 2176 break; 2177 } 2178 /* write it back and re-read */ 2179 start = d; 2180 while (d != read_disk) { 2181 if (d==0) 2182 d = conf->raid_disks * 2; 2183 d--; 2184 rcu_read_lock(); 2185 rdev = rcu_dereference(conf->mirrors[d].rdev); 2186 if (rdev && 2187 !test_bit(Faulty, &rdev->flags)) { 2188 atomic_inc(&rdev->nr_pending); 2189 rcu_read_unlock(); 2190 r1_sync_page_io(rdev, sect, s, 2191 conf->tmppage, WRITE); 2192 rdev_dec_pending(rdev, mddev); 2193 } else 2194 rcu_read_unlock(); 2195 } 2196 d = start; 2197 while (d != read_disk) { 2198 char b[BDEVNAME_SIZE]; 2199 if (d==0) 2200 d = conf->raid_disks * 2; 2201 d--; 2202 rcu_read_lock(); 2203 rdev = rcu_dereference(conf->mirrors[d].rdev); 2204 if (rdev && 2205 !test_bit(Faulty, &rdev->flags)) { 2206 atomic_inc(&rdev->nr_pending); 2207 rcu_read_unlock(); 2208 if (r1_sync_page_io(rdev, sect, s, 2209 conf->tmppage, READ)) { 2210 atomic_add(s, &rdev->corrected_errors); 2211 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n", 2212 mdname(mddev), s, 2213 (unsigned long long)(sect + 2214 rdev->data_offset), 2215 bdevname(rdev->bdev, b)); 2216 } 2217 rdev_dec_pending(rdev, mddev); 2218 } else 2219 rcu_read_unlock(); 2220 } 2221 sectors -= s; 2222 sect += s; 2223 } 2224 } 2225 2226 static int narrow_write_error(struct r1bio *r1_bio, int i) 2227 { 2228 struct mddev *mddev = r1_bio->mddev; 2229 struct r1conf *conf = mddev->private; 2230 struct md_rdev *rdev = conf->mirrors[i].rdev; 2231 2232 /* bio has the data to be written to device 'i' where 2233 * we just recently had a write error. 2234 * We repeatedly clone the bio and trim down to one block, 2235 * then try the write. Where the write fails we record 2236 * a bad block. 2237 * It is conceivable that the bio doesn't exactly align with 2238 * blocks. We must handle this somehow. 2239 * 2240 * We currently own a reference on the rdev. 2241 */ 2242 2243 int block_sectors; 2244 sector_t sector; 2245 int sectors; 2246 int sect_to_write = r1_bio->sectors; 2247 int ok = 1; 2248 2249 if (rdev->badblocks.shift < 0) 2250 return 0; 2251 2252 block_sectors = roundup(1 << rdev->badblocks.shift, 2253 bdev_logical_block_size(rdev->bdev) >> 9); 2254 sector = r1_bio->sector; 2255 sectors = ((sector + block_sectors) 2256 & ~(sector_t)(block_sectors - 1)) 2257 - sector; 2258 2259 while (sect_to_write) { 2260 struct bio *wbio; 2261 if (sectors > sect_to_write) 2262 sectors = sect_to_write; 2263 /* Write at 'sector' for 'sectors'*/ 2264 2265 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 2266 unsigned vcnt = r1_bio->behind_page_count; 2267 struct bio_vec *vec = r1_bio->behind_bvecs; 2268 2269 while (!vec->bv_page) { 2270 vec++; 2271 vcnt--; 2272 } 2273 2274 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev); 2275 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec)); 2276 2277 wbio->bi_vcnt = vcnt; 2278 } else { 2279 wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); 2280 } 2281 2282 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0); 2283 wbio->bi_iter.bi_sector = r1_bio->sector; 2284 wbio->bi_iter.bi_size = r1_bio->sectors << 9; 2285 2286 bio_trim(wbio, sector - r1_bio->sector, sectors); 2287 wbio->bi_iter.bi_sector += rdev->data_offset; 2288 wbio->bi_bdev = rdev->bdev; 2289 2290 if (submit_bio_wait(wbio) < 0) 2291 /* failure! */ 2292 ok = rdev_set_badblocks(rdev, sector, 2293 sectors, 0) 2294 && ok; 2295 2296 bio_put(wbio); 2297 sect_to_write -= sectors; 2298 sector += sectors; 2299 sectors = block_sectors; 2300 } 2301 return ok; 2302 } 2303 2304 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2305 { 2306 int m; 2307 int s = r1_bio->sectors; 2308 for (m = 0; m < conf->raid_disks * 2 ; m++) { 2309 struct md_rdev *rdev = conf->mirrors[m].rdev; 2310 struct bio *bio = r1_bio->bios[m]; 2311 if (bio->bi_end_io == NULL) 2312 continue; 2313 if (!bio->bi_error && 2314 test_bit(R1BIO_MadeGood, &r1_bio->state)) { 2315 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0); 2316 } 2317 if (bio->bi_error && 2318 test_bit(R1BIO_WriteError, &r1_bio->state)) { 2319 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0)) 2320 md_error(conf->mddev, rdev); 2321 } 2322 } 2323 put_buf(r1_bio); 2324 md_done_sync(conf->mddev, s, 1); 2325 } 2326 2327 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2328 { 2329 int m; 2330 bool fail = false; 2331 for (m = 0; m < conf->raid_disks * 2 ; m++) 2332 if (r1_bio->bios[m] == IO_MADE_GOOD) { 2333 struct md_rdev *rdev = conf->mirrors[m].rdev; 2334 rdev_clear_badblocks(rdev, 2335 r1_bio->sector, 2336 r1_bio->sectors, 0); 2337 rdev_dec_pending(rdev, conf->mddev); 2338 } else if (r1_bio->bios[m] != NULL) { 2339 /* This drive got a write error. We need to 2340 * narrow down and record precise write 2341 * errors. 2342 */ 2343 fail = true; 2344 if (!narrow_write_error(r1_bio, m)) { 2345 md_error(conf->mddev, 2346 conf->mirrors[m].rdev); 2347 /* an I/O failed, we can't clear the bitmap */ 2348 set_bit(R1BIO_Degraded, &r1_bio->state); 2349 } 2350 rdev_dec_pending(conf->mirrors[m].rdev, 2351 conf->mddev); 2352 } 2353 if (fail) { 2354 spin_lock_irq(&conf->device_lock); 2355 list_add(&r1_bio->retry_list, &conf->bio_end_io_list); 2356 conf->nr_queued++; 2357 spin_unlock_irq(&conf->device_lock); 2358 md_wakeup_thread(conf->mddev->thread); 2359 } else { 2360 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 2361 close_write(r1_bio); 2362 raid_end_bio_io(r1_bio); 2363 } 2364 } 2365 2366 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio) 2367 { 2368 int disk; 2369 int max_sectors; 2370 struct mddev *mddev = conf->mddev; 2371 struct bio *bio; 2372 char b[BDEVNAME_SIZE]; 2373 struct md_rdev *rdev; 2374 dev_t bio_dev; 2375 sector_t bio_sector; 2376 2377 clear_bit(R1BIO_ReadError, &r1_bio->state); 2378 /* we got a read error. Maybe the drive is bad. Maybe just 2379 * the block and we can fix it. 2380 * We freeze all other IO, and try reading the block from 2381 * other devices. When we find one, we re-write 2382 * and check it that fixes the read error. 2383 * This is all done synchronously while the array is 2384 * frozen 2385 */ 2386 2387 bio = r1_bio->bios[r1_bio->read_disk]; 2388 bdevname(bio->bi_bdev, b); 2389 bio_dev = bio->bi_bdev->bd_dev; 2390 bio_sector = conf->mirrors[r1_bio->read_disk].rdev->data_offset + r1_bio->sector; 2391 bio_put(bio); 2392 r1_bio->bios[r1_bio->read_disk] = NULL; 2393 2394 rdev = conf->mirrors[r1_bio->read_disk].rdev; 2395 if (mddev->ro == 0 2396 && !test_bit(FailFast, &rdev->flags)) { 2397 freeze_array(conf, 1); 2398 fix_read_error(conf, r1_bio->read_disk, 2399 r1_bio->sector, r1_bio->sectors); 2400 unfreeze_array(conf); 2401 } else { 2402 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED; 2403 } 2404 2405 rdev_dec_pending(rdev, conf->mddev); 2406 2407 read_more: 2408 disk = read_balance(conf, r1_bio, &max_sectors); 2409 if (disk == -1) { 2410 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n", 2411 mdname(mddev), b, (unsigned long long)r1_bio->sector); 2412 raid_end_bio_io(r1_bio); 2413 } else { 2414 const unsigned long do_sync 2415 = r1_bio->master_bio->bi_opf & REQ_SYNC; 2416 r1_bio->read_disk = disk; 2417 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); 2418 bio_trim(bio, r1_bio->sector - bio->bi_iter.bi_sector, 2419 max_sectors); 2420 r1_bio->bios[r1_bio->read_disk] = bio; 2421 rdev = conf->mirrors[disk].rdev; 2422 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n", 2423 mdname(mddev), 2424 (unsigned long long)r1_bio->sector, 2425 bdevname(rdev->bdev, b)); 2426 bio->bi_iter.bi_sector = r1_bio->sector + rdev->data_offset; 2427 bio->bi_bdev = rdev->bdev; 2428 bio->bi_end_io = raid1_end_read_request; 2429 bio_set_op_attrs(bio, REQ_OP_READ, do_sync); 2430 if (test_bit(FailFast, &rdev->flags) && 2431 test_bit(R1BIO_FailFast, &r1_bio->state)) 2432 bio->bi_opf |= MD_FAILFAST; 2433 bio->bi_private = r1_bio; 2434 if (max_sectors < r1_bio->sectors) { 2435 /* Drat - have to split this up more */ 2436 struct bio *mbio = r1_bio->master_bio; 2437 int sectors_handled = (r1_bio->sector + max_sectors 2438 - mbio->bi_iter.bi_sector); 2439 r1_bio->sectors = max_sectors; 2440 spin_lock_irq(&conf->device_lock); 2441 if (mbio->bi_phys_segments == 0) 2442 mbio->bi_phys_segments = 2; 2443 else 2444 mbio->bi_phys_segments++; 2445 spin_unlock_irq(&conf->device_lock); 2446 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev), 2447 bio, bio_dev, bio_sector); 2448 generic_make_request(bio); 2449 bio = NULL; 2450 2451 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 2452 2453 r1_bio->master_bio = mbio; 2454 r1_bio->sectors = bio_sectors(mbio) - sectors_handled; 2455 r1_bio->state = 0; 2456 set_bit(R1BIO_ReadError, &r1_bio->state); 2457 r1_bio->mddev = mddev; 2458 r1_bio->sector = mbio->bi_iter.bi_sector + 2459 sectors_handled; 2460 2461 goto read_more; 2462 } else { 2463 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev), 2464 bio, bio_dev, bio_sector); 2465 generic_make_request(bio); 2466 } 2467 } 2468 } 2469 2470 static void raid1d(struct md_thread *thread) 2471 { 2472 struct mddev *mddev = thread->mddev; 2473 struct r1bio *r1_bio; 2474 unsigned long flags; 2475 struct r1conf *conf = mddev->private; 2476 struct list_head *head = &conf->retry_list; 2477 struct blk_plug plug; 2478 2479 md_check_recovery(mddev); 2480 2481 if (!list_empty_careful(&conf->bio_end_io_list) && 2482 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) { 2483 LIST_HEAD(tmp); 2484 spin_lock_irqsave(&conf->device_lock, flags); 2485 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) { 2486 while (!list_empty(&conf->bio_end_io_list)) { 2487 list_move(conf->bio_end_io_list.prev, &tmp); 2488 conf->nr_queued--; 2489 } 2490 } 2491 spin_unlock_irqrestore(&conf->device_lock, flags); 2492 while (!list_empty(&tmp)) { 2493 r1_bio = list_first_entry(&tmp, struct r1bio, 2494 retry_list); 2495 list_del(&r1_bio->retry_list); 2496 if (mddev->degraded) 2497 set_bit(R1BIO_Degraded, &r1_bio->state); 2498 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 2499 close_write(r1_bio); 2500 raid_end_bio_io(r1_bio); 2501 } 2502 } 2503 2504 blk_start_plug(&plug); 2505 for (;;) { 2506 2507 flush_pending_writes(conf); 2508 2509 spin_lock_irqsave(&conf->device_lock, flags); 2510 if (list_empty(head)) { 2511 spin_unlock_irqrestore(&conf->device_lock, flags); 2512 break; 2513 } 2514 r1_bio = list_entry(head->prev, struct r1bio, retry_list); 2515 list_del(head->prev); 2516 conf->nr_queued--; 2517 spin_unlock_irqrestore(&conf->device_lock, flags); 2518 2519 mddev = r1_bio->mddev; 2520 conf = mddev->private; 2521 if (test_bit(R1BIO_IsSync, &r1_bio->state)) { 2522 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2523 test_bit(R1BIO_WriteError, &r1_bio->state)) 2524 handle_sync_write_finished(conf, r1_bio); 2525 else 2526 sync_request_write(mddev, r1_bio); 2527 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2528 test_bit(R1BIO_WriteError, &r1_bio->state)) 2529 handle_write_finished(conf, r1_bio); 2530 else if (test_bit(R1BIO_ReadError, &r1_bio->state)) 2531 handle_read_error(conf, r1_bio); 2532 else 2533 /* just a partial read to be scheduled from separate 2534 * context 2535 */ 2536 generic_make_request(r1_bio->bios[r1_bio->read_disk]); 2537 2538 cond_resched(); 2539 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING)) 2540 md_check_recovery(mddev); 2541 } 2542 blk_finish_plug(&plug); 2543 } 2544 2545 static int init_resync(struct r1conf *conf) 2546 { 2547 int buffs; 2548 2549 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; 2550 BUG_ON(conf->r1buf_pool); 2551 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, 2552 conf->poolinfo); 2553 if (!conf->r1buf_pool) 2554 return -ENOMEM; 2555 conf->next_resync = 0; 2556 return 0; 2557 } 2558 2559 /* 2560 * perform a "sync" on one "block" 2561 * 2562 * We need to make sure that no normal I/O request - particularly write 2563 * requests - conflict with active sync requests. 2564 * 2565 * This is achieved by tracking pending requests and a 'barrier' concept 2566 * that can be installed to exclude normal IO requests. 2567 */ 2568 2569 static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr, 2570 int *skipped) 2571 { 2572 struct r1conf *conf = mddev->private; 2573 struct r1bio *r1_bio; 2574 struct bio *bio; 2575 sector_t max_sector, nr_sectors; 2576 int disk = -1; 2577 int i; 2578 int wonly = -1; 2579 int write_targets = 0, read_targets = 0; 2580 sector_t sync_blocks; 2581 int still_degraded = 0; 2582 int good_sectors = RESYNC_SECTORS; 2583 int min_bad = 0; /* number of sectors that are bad in all devices */ 2584 2585 if (!conf->r1buf_pool) 2586 if (init_resync(conf)) 2587 return 0; 2588 2589 max_sector = mddev->dev_sectors; 2590 if (sector_nr >= max_sector) { 2591 /* If we aborted, we need to abort the 2592 * sync on the 'current' bitmap chunk (there will 2593 * only be one in raid1 resync. 2594 * We can find the current addess in mddev->curr_resync 2595 */ 2596 if (mddev->curr_resync < max_sector) /* aborted */ 2597 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 2598 &sync_blocks, 1); 2599 else /* completed sync */ 2600 conf->fullsync = 0; 2601 2602 bitmap_close_sync(mddev->bitmap); 2603 close_sync(conf); 2604 2605 if (mddev_is_clustered(mddev)) { 2606 conf->cluster_sync_low = 0; 2607 conf->cluster_sync_high = 0; 2608 } 2609 return 0; 2610 } 2611 2612 if (mddev->bitmap == NULL && 2613 mddev->recovery_cp == MaxSector && 2614 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 2615 conf->fullsync == 0) { 2616 *skipped = 1; 2617 return max_sector - sector_nr; 2618 } 2619 /* before building a request, check if we can skip these blocks.. 2620 * This call the bitmap_start_sync doesn't actually record anything 2621 */ 2622 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 2623 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2624 /* We can skip this block, and probably several more */ 2625 *skipped = 1; 2626 return sync_blocks; 2627 } 2628 2629 /* 2630 * If there is non-resync activity waiting for a turn, then let it 2631 * though before starting on this new sync request. 2632 */ 2633 if (conf->nr_waiting) 2634 schedule_timeout_uninterruptible(1); 2635 2636 /* we are incrementing sector_nr below. To be safe, we check against 2637 * sector_nr + two times RESYNC_SECTORS 2638 */ 2639 2640 bitmap_cond_end_sync(mddev->bitmap, sector_nr, 2641 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high)); 2642 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); 2643 2644 raise_barrier(conf, sector_nr); 2645 2646 rcu_read_lock(); 2647 /* 2648 * If we get a correctably read error during resync or recovery, 2649 * we might want to read from a different device. So we 2650 * flag all drives that could conceivably be read from for READ, 2651 * and any others (which will be non-In_sync devices) for WRITE. 2652 * If a read fails, we try reading from something else for which READ 2653 * is OK. 2654 */ 2655 2656 r1_bio->mddev = mddev; 2657 r1_bio->sector = sector_nr; 2658 r1_bio->state = 0; 2659 set_bit(R1BIO_IsSync, &r1_bio->state); 2660 2661 for (i = 0; i < conf->raid_disks * 2; i++) { 2662 struct md_rdev *rdev; 2663 bio = r1_bio->bios[i]; 2664 bio_reset(bio); 2665 2666 rdev = rcu_dereference(conf->mirrors[i].rdev); 2667 if (rdev == NULL || 2668 test_bit(Faulty, &rdev->flags)) { 2669 if (i < conf->raid_disks) 2670 still_degraded = 1; 2671 } else if (!test_bit(In_sync, &rdev->flags)) { 2672 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 2673 bio->bi_end_io = end_sync_write; 2674 write_targets ++; 2675 } else { 2676 /* may need to read from here */ 2677 sector_t first_bad = MaxSector; 2678 int bad_sectors; 2679 2680 if (is_badblock(rdev, sector_nr, good_sectors, 2681 &first_bad, &bad_sectors)) { 2682 if (first_bad > sector_nr) 2683 good_sectors = first_bad - sector_nr; 2684 else { 2685 bad_sectors -= (sector_nr - first_bad); 2686 if (min_bad == 0 || 2687 min_bad > bad_sectors) 2688 min_bad = bad_sectors; 2689 } 2690 } 2691 if (sector_nr < first_bad) { 2692 if (test_bit(WriteMostly, &rdev->flags)) { 2693 if (wonly < 0) 2694 wonly = i; 2695 } else { 2696 if (disk < 0) 2697 disk = i; 2698 } 2699 bio_set_op_attrs(bio, REQ_OP_READ, 0); 2700 bio->bi_end_io = end_sync_read; 2701 read_targets++; 2702 } else if (!test_bit(WriteErrorSeen, &rdev->flags) && 2703 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && 2704 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) { 2705 /* 2706 * The device is suitable for reading (InSync), 2707 * but has bad block(s) here. Let's try to correct them, 2708 * if we are doing resync or repair. Otherwise, leave 2709 * this device alone for this sync request. 2710 */ 2711 bio_set_op_attrs(bio, REQ_OP_WRITE, 0); 2712 bio->bi_end_io = end_sync_write; 2713 write_targets++; 2714 } 2715 } 2716 if (bio->bi_end_io) { 2717 atomic_inc(&rdev->nr_pending); 2718 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset; 2719 bio->bi_bdev = rdev->bdev; 2720 bio->bi_private = r1_bio; 2721 if (test_bit(FailFast, &rdev->flags)) 2722 bio->bi_opf |= MD_FAILFAST; 2723 } 2724 } 2725 rcu_read_unlock(); 2726 if (disk < 0) 2727 disk = wonly; 2728 r1_bio->read_disk = disk; 2729 2730 if (read_targets == 0 && min_bad > 0) { 2731 /* These sectors are bad on all InSync devices, so we 2732 * need to mark them bad on all write targets 2733 */ 2734 int ok = 1; 2735 for (i = 0 ; i < conf->raid_disks * 2 ; i++) 2736 if (r1_bio->bios[i]->bi_end_io == end_sync_write) { 2737 struct md_rdev *rdev = conf->mirrors[i].rdev; 2738 ok = rdev_set_badblocks(rdev, sector_nr, 2739 min_bad, 0 2740 ) && ok; 2741 } 2742 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); 2743 *skipped = 1; 2744 put_buf(r1_bio); 2745 2746 if (!ok) { 2747 /* Cannot record the badblocks, so need to 2748 * abort the resync. 2749 * If there are multiple read targets, could just 2750 * fail the really bad ones ??? 2751 */ 2752 conf->recovery_disabled = mddev->recovery_disabled; 2753 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 2754 return 0; 2755 } else 2756 return min_bad; 2757 2758 } 2759 if (min_bad > 0 && min_bad < good_sectors) { 2760 /* only resync enough to reach the next bad->good 2761 * transition */ 2762 good_sectors = min_bad; 2763 } 2764 2765 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) 2766 /* extra read targets are also write targets */ 2767 write_targets += read_targets-1; 2768 2769 if (write_targets == 0 || read_targets == 0) { 2770 /* There is nowhere to write, so all non-sync 2771 * drives must be failed - so we are finished 2772 */ 2773 sector_t rv; 2774 if (min_bad > 0) 2775 max_sector = sector_nr + min_bad; 2776 rv = max_sector - sector_nr; 2777 *skipped = 1; 2778 put_buf(r1_bio); 2779 return rv; 2780 } 2781 2782 if (max_sector > mddev->resync_max) 2783 max_sector = mddev->resync_max; /* Don't do IO beyond here */ 2784 if (max_sector > sector_nr + good_sectors) 2785 max_sector = sector_nr + good_sectors; 2786 nr_sectors = 0; 2787 sync_blocks = 0; 2788 do { 2789 struct page *page; 2790 int len = PAGE_SIZE; 2791 if (sector_nr + (len>>9) > max_sector) 2792 len = (max_sector - sector_nr) << 9; 2793 if (len == 0) 2794 break; 2795 if (sync_blocks == 0) { 2796 if (!bitmap_start_sync(mddev->bitmap, sector_nr, 2797 &sync_blocks, still_degraded) && 2798 !conf->fullsync && 2799 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 2800 break; 2801 if ((len >> 9) > sync_blocks) 2802 len = sync_blocks<<9; 2803 } 2804 2805 for (i = 0 ; i < conf->raid_disks * 2; i++) { 2806 bio = r1_bio->bios[i]; 2807 if (bio->bi_end_io) { 2808 page = bio->bi_io_vec[bio->bi_vcnt].bv_page; 2809 if (bio_add_page(bio, page, len, 0) == 0) { 2810 /* stop here */ 2811 bio->bi_io_vec[bio->bi_vcnt].bv_page = page; 2812 while (i > 0) { 2813 i--; 2814 bio = r1_bio->bios[i]; 2815 if (bio->bi_end_io==NULL) 2816 continue; 2817 /* remove last page from this bio */ 2818 bio->bi_vcnt--; 2819 bio->bi_iter.bi_size -= len; 2820 bio_clear_flag(bio, BIO_SEG_VALID); 2821 } 2822 goto bio_full; 2823 } 2824 } 2825 } 2826 nr_sectors += len>>9; 2827 sector_nr += len>>9; 2828 sync_blocks -= (len>>9); 2829 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); 2830 bio_full: 2831 r1_bio->sectors = nr_sectors; 2832 2833 if (mddev_is_clustered(mddev) && 2834 conf->cluster_sync_high < sector_nr + nr_sectors) { 2835 conf->cluster_sync_low = mddev->curr_resync_completed; 2836 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS; 2837 /* Send resync message */ 2838 md_cluster_ops->resync_info_update(mddev, 2839 conf->cluster_sync_low, 2840 conf->cluster_sync_high); 2841 } 2842 2843 /* For a user-requested sync, we read all readable devices and do a 2844 * compare 2845 */ 2846 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2847 atomic_set(&r1_bio->remaining, read_targets); 2848 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) { 2849 bio = r1_bio->bios[i]; 2850 if (bio->bi_end_io == end_sync_read) { 2851 read_targets--; 2852 md_sync_acct(bio->bi_bdev, nr_sectors); 2853 if (read_targets == 1) 2854 bio->bi_opf &= ~MD_FAILFAST; 2855 generic_make_request(bio); 2856 } 2857 } 2858 } else { 2859 atomic_set(&r1_bio->remaining, 1); 2860 bio = r1_bio->bios[r1_bio->read_disk]; 2861 md_sync_acct(bio->bi_bdev, nr_sectors); 2862 if (read_targets == 1) 2863 bio->bi_opf &= ~MD_FAILFAST; 2864 generic_make_request(bio); 2865 2866 } 2867 return nr_sectors; 2868 } 2869 2870 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks) 2871 { 2872 if (sectors) 2873 return sectors; 2874 2875 return mddev->dev_sectors; 2876 } 2877 2878 static struct r1conf *setup_conf(struct mddev *mddev) 2879 { 2880 struct r1conf *conf; 2881 int i; 2882 struct raid1_info *disk; 2883 struct md_rdev *rdev; 2884 int err = -ENOMEM; 2885 2886 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL); 2887 if (!conf) 2888 goto abort; 2889 2890 conf->mirrors = kzalloc(sizeof(struct raid1_info) 2891 * mddev->raid_disks * 2, 2892 GFP_KERNEL); 2893 if (!conf->mirrors) 2894 goto abort; 2895 2896 conf->tmppage = alloc_page(GFP_KERNEL); 2897 if (!conf->tmppage) 2898 goto abort; 2899 2900 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); 2901 if (!conf->poolinfo) 2902 goto abort; 2903 conf->poolinfo->raid_disks = mddev->raid_disks * 2; 2904 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2905 r1bio_pool_free, 2906 conf->poolinfo); 2907 if (!conf->r1bio_pool) 2908 goto abort; 2909 2910 conf->poolinfo->mddev = mddev; 2911 2912 err = -EINVAL; 2913 spin_lock_init(&conf->device_lock); 2914 rdev_for_each(rdev, mddev) { 2915 struct request_queue *q; 2916 int disk_idx = rdev->raid_disk; 2917 if (disk_idx >= mddev->raid_disks 2918 || disk_idx < 0) 2919 continue; 2920 if (test_bit(Replacement, &rdev->flags)) 2921 disk = conf->mirrors + mddev->raid_disks + disk_idx; 2922 else 2923 disk = conf->mirrors + disk_idx; 2924 2925 if (disk->rdev) 2926 goto abort; 2927 disk->rdev = rdev; 2928 q = bdev_get_queue(rdev->bdev); 2929 2930 disk->head_position = 0; 2931 disk->seq_start = MaxSector; 2932 } 2933 conf->raid_disks = mddev->raid_disks; 2934 conf->mddev = mddev; 2935 INIT_LIST_HEAD(&conf->retry_list); 2936 INIT_LIST_HEAD(&conf->bio_end_io_list); 2937 2938 spin_lock_init(&conf->resync_lock); 2939 init_waitqueue_head(&conf->wait_barrier); 2940 2941 bio_list_init(&conf->pending_bio_list); 2942 conf->pending_count = 0; 2943 conf->recovery_disabled = mddev->recovery_disabled - 1; 2944 2945 conf->start_next_window = MaxSector; 2946 conf->current_window_requests = conf->next_window_requests = 0; 2947 2948 err = -EIO; 2949 for (i = 0; i < conf->raid_disks * 2; i++) { 2950 2951 disk = conf->mirrors + i; 2952 2953 if (i < conf->raid_disks && 2954 disk[conf->raid_disks].rdev) { 2955 /* This slot has a replacement. */ 2956 if (!disk->rdev) { 2957 /* No original, just make the replacement 2958 * a recovering spare 2959 */ 2960 disk->rdev = 2961 disk[conf->raid_disks].rdev; 2962 disk[conf->raid_disks].rdev = NULL; 2963 } else if (!test_bit(In_sync, &disk->rdev->flags)) 2964 /* Original is not in_sync - bad */ 2965 goto abort; 2966 } 2967 2968 if (!disk->rdev || 2969 !test_bit(In_sync, &disk->rdev->flags)) { 2970 disk->head_position = 0; 2971 if (disk->rdev && 2972 (disk->rdev->saved_raid_disk < 0)) 2973 conf->fullsync = 1; 2974 } 2975 } 2976 2977 err = -ENOMEM; 2978 conf->thread = md_register_thread(raid1d, mddev, "raid1"); 2979 if (!conf->thread) 2980 goto abort; 2981 2982 return conf; 2983 2984 abort: 2985 if (conf) { 2986 mempool_destroy(conf->r1bio_pool); 2987 kfree(conf->mirrors); 2988 safe_put_page(conf->tmppage); 2989 kfree(conf->poolinfo); 2990 kfree(conf); 2991 } 2992 return ERR_PTR(err); 2993 } 2994 2995 static void raid1_free(struct mddev *mddev, void *priv); 2996 static int raid1_run(struct mddev *mddev) 2997 { 2998 struct r1conf *conf; 2999 int i; 3000 struct md_rdev *rdev; 3001 int ret; 3002 bool discard_supported = false; 3003 3004 if (mddev->level != 1) { 3005 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n", 3006 mdname(mddev), mddev->level); 3007 return -EIO; 3008 } 3009 if (mddev->reshape_position != MaxSector) { 3010 pr_warn("md/raid1:%s: reshape_position set but not supported\n", 3011 mdname(mddev)); 3012 return -EIO; 3013 } 3014 /* 3015 * copy the already verified devices into our private RAID1 3016 * bookkeeping area. [whatever we allocate in run(), 3017 * should be freed in raid1_free()] 3018 */ 3019 if (mddev->private == NULL) 3020 conf = setup_conf(mddev); 3021 else 3022 conf = mddev->private; 3023 3024 if (IS_ERR(conf)) 3025 return PTR_ERR(conf); 3026 3027 if (mddev->queue) 3028 blk_queue_max_write_same_sectors(mddev->queue, 0); 3029 3030 rdev_for_each(rdev, mddev) { 3031 if (!mddev->gendisk) 3032 continue; 3033 disk_stack_limits(mddev->gendisk, rdev->bdev, 3034 rdev->data_offset << 9); 3035 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 3036 discard_supported = true; 3037 } 3038 3039 mddev->degraded = 0; 3040 for (i=0; i < conf->raid_disks; i++) 3041 if (conf->mirrors[i].rdev == NULL || 3042 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || 3043 test_bit(Faulty, &conf->mirrors[i].rdev->flags)) 3044 mddev->degraded++; 3045 3046 if (conf->raid_disks - mddev->degraded == 1) 3047 mddev->recovery_cp = MaxSector; 3048 3049 if (mddev->recovery_cp != MaxSector) 3050 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n", 3051 mdname(mddev)); 3052 pr_info("md/raid1:%s: active with %d out of %d mirrors\n", 3053 mdname(mddev), mddev->raid_disks - mddev->degraded, 3054 mddev->raid_disks); 3055 3056 /* 3057 * Ok, everything is just fine now 3058 */ 3059 mddev->thread = conf->thread; 3060 conf->thread = NULL; 3061 mddev->private = conf; 3062 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags); 3063 3064 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); 3065 3066 if (mddev->queue) { 3067 if (discard_supported) 3068 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, 3069 mddev->queue); 3070 else 3071 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, 3072 mddev->queue); 3073 } 3074 3075 ret = md_integrity_register(mddev); 3076 if (ret) { 3077 md_unregister_thread(&mddev->thread); 3078 raid1_free(mddev, conf); 3079 } 3080 return ret; 3081 } 3082 3083 static void raid1_free(struct mddev *mddev, void *priv) 3084 { 3085 struct r1conf *conf = priv; 3086 3087 mempool_destroy(conf->r1bio_pool); 3088 kfree(conf->mirrors); 3089 safe_put_page(conf->tmppage); 3090 kfree(conf->poolinfo); 3091 kfree(conf); 3092 } 3093 3094 static int raid1_resize(struct mddev *mddev, sector_t sectors) 3095 { 3096 /* no resync is happening, and there is enough space 3097 * on all devices, so we can resize. 3098 * We need to make sure resync covers any new space. 3099 * If the array is shrinking we should possibly wait until 3100 * any io in the removed space completes, but it hardly seems 3101 * worth it. 3102 */ 3103 sector_t newsize = raid1_size(mddev, sectors, 0); 3104 if (mddev->external_size && 3105 mddev->array_sectors > newsize) 3106 return -EINVAL; 3107 if (mddev->bitmap) { 3108 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0); 3109 if (ret) 3110 return ret; 3111 } 3112 md_set_array_sectors(mddev, newsize); 3113 set_capacity(mddev->gendisk, mddev->array_sectors); 3114 revalidate_disk(mddev->gendisk); 3115 if (sectors > mddev->dev_sectors && 3116 mddev->recovery_cp > mddev->dev_sectors) { 3117 mddev->recovery_cp = mddev->dev_sectors; 3118 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3119 } 3120 mddev->dev_sectors = sectors; 3121 mddev->resync_max_sectors = sectors; 3122 return 0; 3123 } 3124 3125 static int raid1_reshape(struct mddev *mddev) 3126 { 3127 /* We need to: 3128 * 1/ resize the r1bio_pool 3129 * 2/ resize conf->mirrors 3130 * 3131 * We allocate a new r1bio_pool if we can. 3132 * Then raise a device barrier and wait until all IO stops. 3133 * Then resize conf->mirrors and swap in the new r1bio pool. 3134 * 3135 * At the same time, we "pack" the devices so that all the missing 3136 * devices have the higher raid_disk numbers. 3137 */ 3138 mempool_t *newpool, *oldpool; 3139 struct pool_info *newpoolinfo; 3140 struct raid1_info *newmirrors; 3141 struct r1conf *conf = mddev->private; 3142 int cnt, raid_disks; 3143 unsigned long flags; 3144 int d, d2, err; 3145 3146 /* Cannot change chunk_size, layout, or level */ 3147 if (mddev->chunk_sectors != mddev->new_chunk_sectors || 3148 mddev->layout != mddev->new_layout || 3149 mddev->level != mddev->new_level) { 3150 mddev->new_chunk_sectors = mddev->chunk_sectors; 3151 mddev->new_layout = mddev->layout; 3152 mddev->new_level = mddev->level; 3153 return -EINVAL; 3154 } 3155 3156 if (!mddev_is_clustered(mddev)) { 3157 err = md_allow_write(mddev); 3158 if (err) 3159 return err; 3160 } 3161 3162 raid_disks = mddev->raid_disks + mddev->delta_disks; 3163 3164 if (raid_disks < conf->raid_disks) { 3165 cnt=0; 3166 for (d= 0; d < conf->raid_disks; d++) 3167 if (conf->mirrors[d].rdev) 3168 cnt++; 3169 if (cnt > raid_disks) 3170 return -EBUSY; 3171 } 3172 3173 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); 3174 if (!newpoolinfo) 3175 return -ENOMEM; 3176 newpoolinfo->mddev = mddev; 3177 newpoolinfo->raid_disks = raid_disks * 2; 3178 3179 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 3180 r1bio_pool_free, newpoolinfo); 3181 if (!newpool) { 3182 kfree(newpoolinfo); 3183 return -ENOMEM; 3184 } 3185 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2, 3186 GFP_KERNEL); 3187 if (!newmirrors) { 3188 kfree(newpoolinfo); 3189 mempool_destroy(newpool); 3190 return -ENOMEM; 3191 } 3192 3193 freeze_array(conf, 0); 3194 3195 /* ok, everything is stopped */ 3196 oldpool = conf->r1bio_pool; 3197 conf->r1bio_pool = newpool; 3198 3199 for (d = d2 = 0; d < conf->raid_disks; d++) { 3200 struct md_rdev *rdev = conf->mirrors[d].rdev; 3201 if (rdev && rdev->raid_disk != d2) { 3202 sysfs_unlink_rdev(mddev, rdev); 3203 rdev->raid_disk = d2; 3204 sysfs_unlink_rdev(mddev, rdev); 3205 if (sysfs_link_rdev(mddev, rdev)) 3206 pr_warn("md/raid1:%s: cannot register rd%d\n", 3207 mdname(mddev), rdev->raid_disk); 3208 } 3209 if (rdev) 3210 newmirrors[d2++].rdev = rdev; 3211 } 3212 kfree(conf->mirrors); 3213 conf->mirrors = newmirrors; 3214 kfree(conf->poolinfo); 3215 conf->poolinfo = newpoolinfo; 3216 3217 spin_lock_irqsave(&conf->device_lock, flags); 3218 mddev->degraded += (raid_disks - conf->raid_disks); 3219 spin_unlock_irqrestore(&conf->device_lock, flags); 3220 conf->raid_disks = mddev->raid_disks = raid_disks; 3221 mddev->delta_disks = 0; 3222 3223 unfreeze_array(conf); 3224 3225 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery); 3226 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3227 md_wakeup_thread(mddev->thread); 3228 3229 mempool_destroy(oldpool); 3230 return 0; 3231 } 3232 3233 static void raid1_quiesce(struct mddev *mddev, int state) 3234 { 3235 struct r1conf *conf = mddev->private; 3236 3237 switch(state) { 3238 case 2: /* wake for suspend */ 3239 wake_up(&conf->wait_barrier); 3240 break; 3241 case 1: 3242 freeze_array(conf, 0); 3243 break; 3244 case 0: 3245 unfreeze_array(conf); 3246 break; 3247 } 3248 } 3249 3250 static void *raid1_takeover(struct mddev *mddev) 3251 { 3252 /* raid1 can take over: 3253 * raid5 with 2 devices, any layout or chunk size 3254 */ 3255 if (mddev->level == 5 && mddev->raid_disks == 2) { 3256 struct r1conf *conf; 3257 mddev->new_level = 1; 3258 mddev->new_layout = 0; 3259 mddev->new_chunk_sectors = 0; 3260 conf = setup_conf(mddev); 3261 if (!IS_ERR(conf)) { 3262 /* Array must appear to be quiesced */ 3263 conf->array_frozen = 1; 3264 mddev_clear_unsupported_flags(mddev, 3265 UNSUPPORTED_MDDEV_FLAGS); 3266 } 3267 return conf; 3268 } 3269 return ERR_PTR(-EINVAL); 3270 } 3271 3272 static struct md_personality raid1_personality = 3273 { 3274 .name = "raid1", 3275 .level = 1, 3276 .owner = THIS_MODULE, 3277 .make_request = raid1_make_request, 3278 .run = raid1_run, 3279 .free = raid1_free, 3280 .status = raid1_status, 3281 .error_handler = raid1_error, 3282 .hot_add_disk = raid1_add_disk, 3283 .hot_remove_disk= raid1_remove_disk, 3284 .spare_active = raid1_spare_active, 3285 .sync_request = raid1_sync_request, 3286 .resize = raid1_resize, 3287 .size = raid1_size, 3288 .check_reshape = raid1_reshape, 3289 .quiesce = raid1_quiesce, 3290 .takeover = raid1_takeover, 3291 .congested = raid1_congested, 3292 }; 3293 3294 static int __init raid_init(void) 3295 { 3296 return register_md_personality(&raid1_personality); 3297 } 3298 3299 static void raid_exit(void) 3300 { 3301 unregister_md_personality(&raid1_personality); 3302 } 3303 3304 module_init(raid_init); 3305 module_exit(raid_exit); 3306 MODULE_LICENSE("GPL"); 3307 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); 3308 MODULE_ALIAS("md-personality-3"); /* RAID1 */ 3309 MODULE_ALIAS("md-raid1"); 3310 MODULE_ALIAS("md-level-1"); 3311 3312 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR); 3313