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