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 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 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 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 (rdev->raid_disk >= 0) 1593 first = last = rdev->raid_disk; 1594 1595 for (mirror = first; mirror <= last; mirror++) { 1596 p = conf->mirrors+mirror; 1597 if (!p->rdev) { 1598 1599 if (mddev->gendisk) 1600 disk_stack_limits(mddev->gendisk, rdev->bdev, 1601 rdev->data_offset << 9); 1602 1603 p->head_position = 0; 1604 rdev->raid_disk = mirror; 1605 err = 0; 1606 /* As all devices are equivalent, we don't need a full recovery 1607 * if this was recently any drive of the array 1608 */ 1609 if (rdev->saved_raid_disk < 0) 1610 conf->fullsync = 1; 1611 rcu_assign_pointer(p->rdev, rdev); 1612 break; 1613 } 1614 if (test_bit(WantReplacement, &p->rdev->flags) && 1615 p[conf->raid_disks].rdev == NULL) { 1616 /* Add this device as a replacement */ 1617 clear_bit(In_sync, &rdev->flags); 1618 set_bit(Replacement, &rdev->flags); 1619 rdev->raid_disk = mirror; 1620 err = 0; 1621 conf->fullsync = 1; 1622 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev); 1623 break; 1624 } 1625 } 1626 md_integrity_add_rdev(rdev, mddev); 1627 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) 1628 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 1629 print_conf(conf); 1630 return err; 1631 } 1632 1633 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev) 1634 { 1635 struct r1conf *conf = mddev->private; 1636 int err = 0; 1637 int number = rdev->raid_disk; 1638 struct raid1_info *p = conf->mirrors + number; 1639 1640 if (rdev != p->rdev) 1641 p = conf->mirrors + conf->raid_disks + number; 1642 1643 print_conf(conf); 1644 if (rdev == p->rdev) { 1645 if (test_bit(In_sync, &rdev->flags) || 1646 atomic_read(&rdev->nr_pending)) { 1647 err = -EBUSY; 1648 goto abort; 1649 } 1650 /* Only remove non-faulty devices if recovery 1651 * is not possible. 1652 */ 1653 if (!test_bit(Faulty, &rdev->flags) && 1654 mddev->recovery_disabled != conf->recovery_disabled && 1655 mddev->degraded < conf->raid_disks) { 1656 err = -EBUSY; 1657 goto abort; 1658 } 1659 p->rdev = NULL; 1660 synchronize_rcu(); 1661 if (atomic_read(&rdev->nr_pending)) { 1662 /* lost the race, try later */ 1663 err = -EBUSY; 1664 p->rdev = rdev; 1665 goto abort; 1666 } else if (conf->mirrors[conf->raid_disks + number].rdev) { 1667 /* We just removed a device that is being replaced. 1668 * Move down the replacement. We drain all IO before 1669 * doing this to avoid confusion. 1670 */ 1671 struct md_rdev *repl = 1672 conf->mirrors[conf->raid_disks + number].rdev; 1673 freeze_array(conf, 0); 1674 clear_bit(Replacement, &repl->flags); 1675 p->rdev = repl; 1676 conf->mirrors[conf->raid_disks + number].rdev = NULL; 1677 unfreeze_array(conf); 1678 clear_bit(WantReplacement, &rdev->flags); 1679 } else 1680 clear_bit(WantReplacement, &rdev->flags); 1681 err = md_integrity_register(mddev); 1682 } 1683 abort: 1684 1685 print_conf(conf); 1686 return err; 1687 } 1688 1689 static void end_sync_read(struct bio *bio) 1690 { 1691 struct r1bio *r1_bio = bio->bi_private; 1692 1693 update_head_pos(r1_bio->read_disk, r1_bio); 1694 1695 /* 1696 * we have read a block, now it needs to be re-written, 1697 * or re-read if the read failed. 1698 * We don't do much here, just schedule handling by raid1d 1699 */ 1700 if (!bio->bi_error) 1701 set_bit(R1BIO_Uptodate, &r1_bio->state); 1702 1703 if (atomic_dec_and_test(&r1_bio->remaining)) 1704 reschedule_retry(r1_bio); 1705 } 1706 1707 static void end_sync_write(struct bio *bio) 1708 { 1709 int uptodate = !bio->bi_error; 1710 struct r1bio *r1_bio = bio->bi_private; 1711 struct mddev *mddev = r1_bio->mddev; 1712 struct r1conf *conf = mddev->private; 1713 int mirror=0; 1714 sector_t first_bad; 1715 int bad_sectors; 1716 1717 mirror = find_bio_disk(r1_bio, bio); 1718 1719 if (!uptodate) { 1720 sector_t sync_blocks = 0; 1721 sector_t s = r1_bio->sector; 1722 long sectors_to_go = r1_bio->sectors; 1723 /* make sure these bits doesn't get cleared. */ 1724 do { 1725 bitmap_end_sync(mddev->bitmap, s, 1726 &sync_blocks, 1); 1727 s += sync_blocks; 1728 sectors_to_go -= sync_blocks; 1729 } while (sectors_to_go > 0); 1730 set_bit(WriteErrorSeen, 1731 &conf->mirrors[mirror].rdev->flags); 1732 if (!test_and_set_bit(WantReplacement, 1733 &conf->mirrors[mirror].rdev->flags)) 1734 set_bit(MD_RECOVERY_NEEDED, & 1735 mddev->recovery); 1736 set_bit(R1BIO_WriteError, &r1_bio->state); 1737 } else if (is_badblock(conf->mirrors[mirror].rdev, 1738 r1_bio->sector, 1739 r1_bio->sectors, 1740 &first_bad, &bad_sectors) && 1741 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev, 1742 r1_bio->sector, 1743 r1_bio->sectors, 1744 &first_bad, &bad_sectors) 1745 ) 1746 set_bit(R1BIO_MadeGood, &r1_bio->state); 1747 1748 if (atomic_dec_and_test(&r1_bio->remaining)) { 1749 int s = r1_bio->sectors; 1750 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 1751 test_bit(R1BIO_WriteError, &r1_bio->state)) 1752 reschedule_retry(r1_bio); 1753 else { 1754 put_buf(r1_bio); 1755 md_done_sync(mddev, s, uptodate); 1756 } 1757 } 1758 } 1759 1760 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector, 1761 int sectors, struct page *page, int rw) 1762 { 1763 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false)) 1764 /* success */ 1765 return 1; 1766 if (rw == WRITE) { 1767 set_bit(WriteErrorSeen, &rdev->flags); 1768 if (!test_and_set_bit(WantReplacement, 1769 &rdev->flags)) 1770 set_bit(MD_RECOVERY_NEEDED, & 1771 rdev->mddev->recovery); 1772 } 1773 /* need to record an error - either for the block or the device */ 1774 if (!rdev_set_badblocks(rdev, sector, sectors, 0)) 1775 md_error(rdev->mddev, rdev); 1776 return 0; 1777 } 1778 1779 static int fix_sync_read_error(struct r1bio *r1_bio) 1780 { 1781 /* Try some synchronous reads of other devices to get 1782 * good data, much like with normal read errors. Only 1783 * read into the pages we already have so we don't 1784 * need to re-issue the read request. 1785 * We don't need to freeze the array, because being in an 1786 * active sync request, there is no normal IO, and 1787 * no overlapping syncs. 1788 * We don't need to check is_badblock() again as we 1789 * made sure that anything with a bad block in range 1790 * will have bi_end_io clear. 1791 */ 1792 struct mddev *mddev = r1_bio->mddev; 1793 struct r1conf *conf = mddev->private; 1794 struct bio *bio = r1_bio->bios[r1_bio->read_disk]; 1795 sector_t sect = r1_bio->sector; 1796 int sectors = r1_bio->sectors; 1797 int idx = 0; 1798 1799 while(sectors) { 1800 int s = sectors; 1801 int d = r1_bio->read_disk; 1802 int success = 0; 1803 struct md_rdev *rdev; 1804 int start; 1805 1806 if (s > (PAGE_SIZE>>9)) 1807 s = PAGE_SIZE >> 9; 1808 do { 1809 if (r1_bio->bios[d]->bi_end_io == end_sync_read) { 1810 /* No rcu protection needed here devices 1811 * can only be removed when no resync is 1812 * active, and resync is currently active 1813 */ 1814 rdev = conf->mirrors[d].rdev; 1815 if (sync_page_io(rdev, sect, s<<9, 1816 bio->bi_io_vec[idx].bv_page, 1817 READ, false)) { 1818 success = 1; 1819 break; 1820 } 1821 } 1822 d++; 1823 if (d == conf->raid_disks * 2) 1824 d = 0; 1825 } while (!success && d != r1_bio->read_disk); 1826 1827 if (!success) { 1828 char b[BDEVNAME_SIZE]; 1829 int abort = 0; 1830 /* Cannot read from anywhere, this block is lost. 1831 * Record a bad block on each device. If that doesn't 1832 * work just disable and interrupt the recovery. 1833 * Don't fail devices as that won't really help. 1834 */ 1835 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error" 1836 " for block %llu\n", 1837 mdname(mddev), 1838 bdevname(bio->bi_bdev, b), 1839 (unsigned long long)r1_bio->sector); 1840 for (d = 0; d < conf->raid_disks * 2; d++) { 1841 rdev = conf->mirrors[d].rdev; 1842 if (!rdev || test_bit(Faulty, &rdev->flags)) 1843 continue; 1844 if (!rdev_set_badblocks(rdev, sect, s, 0)) 1845 abort = 1; 1846 } 1847 if (abort) { 1848 conf->recovery_disabled = 1849 mddev->recovery_disabled; 1850 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1851 md_done_sync(mddev, r1_bio->sectors, 0); 1852 put_buf(r1_bio); 1853 return 0; 1854 } 1855 /* Try next page */ 1856 sectors -= s; 1857 sect += s; 1858 idx++; 1859 continue; 1860 } 1861 1862 start = d; 1863 /* write it back and re-read */ 1864 while (d != r1_bio->read_disk) { 1865 if (d == 0) 1866 d = conf->raid_disks * 2; 1867 d--; 1868 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1869 continue; 1870 rdev = conf->mirrors[d].rdev; 1871 if (r1_sync_page_io(rdev, sect, s, 1872 bio->bi_io_vec[idx].bv_page, 1873 WRITE) == 0) { 1874 r1_bio->bios[d]->bi_end_io = NULL; 1875 rdev_dec_pending(rdev, mddev); 1876 } 1877 } 1878 d = start; 1879 while (d != r1_bio->read_disk) { 1880 if (d == 0) 1881 d = conf->raid_disks * 2; 1882 d--; 1883 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1884 continue; 1885 rdev = conf->mirrors[d].rdev; 1886 if (r1_sync_page_io(rdev, sect, s, 1887 bio->bi_io_vec[idx].bv_page, 1888 READ) != 0) 1889 atomic_add(s, &rdev->corrected_errors); 1890 } 1891 sectors -= s; 1892 sect += s; 1893 idx ++; 1894 } 1895 set_bit(R1BIO_Uptodate, &r1_bio->state); 1896 bio->bi_error = 0; 1897 return 1; 1898 } 1899 1900 static void process_checks(struct r1bio *r1_bio) 1901 { 1902 /* We have read all readable devices. If we haven't 1903 * got the block, then there is no hope left. 1904 * If we have, then we want to do a comparison 1905 * and skip the write if everything is the same. 1906 * If any blocks failed to read, then we need to 1907 * attempt an over-write 1908 */ 1909 struct mddev *mddev = r1_bio->mddev; 1910 struct r1conf *conf = mddev->private; 1911 int primary; 1912 int i; 1913 int vcnt; 1914 1915 /* Fix variable parts of all bios */ 1916 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); 1917 for (i = 0; i < conf->raid_disks * 2; i++) { 1918 int j; 1919 int size; 1920 int error; 1921 struct bio *b = r1_bio->bios[i]; 1922 if (b->bi_end_io != end_sync_read) 1923 continue; 1924 /* fixup the bio for reuse, but preserve errno */ 1925 error = b->bi_error; 1926 bio_reset(b); 1927 b->bi_error = error; 1928 b->bi_vcnt = vcnt; 1929 b->bi_iter.bi_size = r1_bio->sectors << 9; 1930 b->bi_iter.bi_sector = r1_bio->sector + 1931 conf->mirrors[i].rdev->data_offset; 1932 b->bi_bdev = conf->mirrors[i].rdev->bdev; 1933 b->bi_end_io = end_sync_read; 1934 b->bi_private = r1_bio; 1935 1936 size = b->bi_iter.bi_size; 1937 for (j = 0; j < vcnt ; j++) { 1938 struct bio_vec *bi; 1939 bi = &b->bi_io_vec[j]; 1940 bi->bv_offset = 0; 1941 if (size > PAGE_SIZE) 1942 bi->bv_len = PAGE_SIZE; 1943 else 1944 bi->bv_len = size; 1945 size -= PAGE_SIZE; 1946 } 1947 } 1948 for (primary = 0; primary < conf->raid_disks * 2; primary++) 1949 if (r1_bio->bios[primary]->bi_end_io == end_sync_read && 1950 !r1_bio->bios[primary]->bi_error) { 1951 r1_bio->bios[primary]->bi_end_io = NULL; 1952 rdev_dec_pending(conf->mirrors[primary].rdev, mddev); 1953 break; 1954 } 1955 r1_bio->read_disk = primary; 1956 for (i = 0; i < conf->raid_disks * 2; i++) { 1957 int j; 1958 struct bio *pbio = r1_bio->bios[primary]; 1959 struct bio *sbio = r1_bio->bios[i]; 1960 int error = sbio->bi_error; 1961 1962 if (sbio->bi_end_io != end_sync_read) 1963 continue; 1964 /* Now we can 'fixup' the error value */ 1965 sbio->bi_error = 0; 1966 1967 if (!error) { 1968 for (j = vcnt; j-- ; ) { 1969 struct page *p, *s; 1970 p = pbio->bi_io_vec[j].bv_page; 1971 s = sbio->bi_io_vec[j].bv_page; 1972 if (memcmp(page_address(p), 1973 page_address(s), 1974 sbio->bi_io_vec[j].bv_len)) 1975 break; 1976 } 1977 } else 1978 j = 0; 1979 if (j >= 0) 1980 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches); 1981 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) 1982 && !error)) { 1983 /* No need to write to this device. */ 1984 sbio->bi_end_io = NULL; 1985 rdev_dec_pending(conf->mirrors[i].rdev, mddev); 1986 continue; 1987 } 1988 1989 bio_copy_data(sbio, pbio); 1990 } 1991 } 1992 1993 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) 1994 { 1995 struct r1conf *conf = mddev->private; 1996 int i; 1997 int disks = conf->raid_disks * 2; 1998 struct bio *bio, *wbio; 1999 2000 bio = r1_bio->bios[r1_bio->read_disk]; 2001 2002 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) 2003 /* ouch - failed to read all of that. */ 2004 if (!fix_sync_read_error(r1_bio)) 2005 return; 2006 2007 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 2008 process_checks(r1_bio); 2009 2010 /* 2011 * schedule writes 2012 */ 2013 atomic_set(&r1_bio->remaining, 1); 2014 for (i = 0; i < disks ; i++) { 2015 wbio = r1_bio->bios[i]; 2016 if (wbio->bi_end_io == NULL || 2017 (wbio->bi_end_io == end_sync_read && 2018 (i == r1_bio->read_disk || 2019 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) 2020 continue; 2021 2022 wbio->bi_rw = WRITE; 2023 wbio->bi_end_io = end_sync_write; 2024 atomic_inc(&r1_bio->remaining); 2025 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio)); 2026 2027 generic_make_request(wbio); 2028 } 2029 2030 if (atomic_dec_and_test(&r1_bio->remaining)) { 2031 /* if we're here, all write(s) have completed, so clean up */ 2032 int s = r1_bio->sectors; 2033 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2034 test_bit(R1BIO_WriteError, &r1_bio->state)) 2035 reschedule_retry(r1_bio); 2036 else { 2037 put_buf(r1_bio); 2038 md_done_sync(mddev, s, 1); 2039 } 2040 } 2041 } 2042 2043 /* 2044 * This is a kernel thread which: 2045 * 2046 * 1. Retries failed read operations on working mirrors. 2047 * 2. Updates the raid superblock when problems encounter. 2048 * 3. Performs writes following reads for array synchronising. 2049 */ 2050 2051 static void fix_read_error(struct r1conf *conf, int read_disk, 2052 sector_t sect, int sectors) 2053 { 2054 struct mddev *mddev = conf->mddev; 2055 while(sectors) { 2056 int s = sectors; 2057 int d = read_disk; 2058 int success = 0; 2059 int start; 2060 struct md_rdev *rdev; 2061 2062 if (s > (PAGE_SIZE>>9)) 2063 s = PAGE_SIZE >> 9; 2064 2065 do { 2066 /* Note: no rcu protection needed here 2067 * as this is synchronous in the raid1d thread 2068 * which is the thread that might remove 2069 * a device. If raid1d ever becomes multi-threaded.... 2070 */ 2071 sector_t first_bad; 2072 int bad_sectors; 2073 2074 rdev = conf->mirrors[d].rdev; 2075 if (rdev && 2076 (test_bit(In_sync, &rdev->flags) || 2077 (!test_bit(Faulty, &rdev->flags) && 2078 rdev->recovery_offset >= sect + s)) && 2079 is_badblock(rdev, sect, s, 2080 &first_bad, &bad_sectors) == 0 && 2081 sync_page_io(rdev, sect, s<<9, 2082 conf->tmppage, READ, false)) 2083 success = 1; 2084 else { 2085 d++; 2086 if (d == conf->raid_disks * 2) 2087 d = 0; 2088 } 2089 } while (!success && d != read_disk); 2090 2091 if (!success) { 2092 /* Cannot read from anywhere - mark it bad */ 2093 struct md_rdev *rdev = conf->mirrors[read_disk].rdev; 2094 if (!rdev_set_badblocks(rdev, sect, s, 0)) 2095 md_error(mddev, rdev); 2096 break; 2097 } 2098 /* write it back and re-read */ 2099 start = d; 2100 while (d != read_disk) { 2101 if (d==0) 2102 d = conf->raid_disks * 2; 2103 d--; 2104 rdev = conf->mirrors[d].rdev; 2105 if (rdev && 2106 !test_bit(Faulty, &rdev->flags)) 2107 r1_sync_page_io(rdev, sect, s, 2108 conf->tmppage, WRITE); 2109 } 2110 d = start; 2111 while (d != read_disk) { 2112 char b[BDEVNAME_SIZE]; 2113 if (d==0) 2114 d = conf->raid_disks * 2; 2115 d--; 2116 rdev = conf->mirrors[d].rdev; 2117 if (rdev && 2118 !test_bit(Faulty, &rdev->flags)) { 2119 if (r1_sync_page_io(rdev, sect, s, 2120 conf->tmppage, READ)) { 2121 atomic_add(s, &rdev->corrected_errors); 2122 printk(KERN_INFO 2123 "md/raid1:%s: read error corrected " 2124 "(%d sectors at %llu on %s)\n", 2125 mdname(mddev), s, 2126 (unsigned long long)(sect + 2127 rdev->data_offset), 2128 bdevname(rdev->bdev, b)); 2129 } 2130 } 2131 } 2132 sectors -= s; 2133 sect += s; 2134 } 2135 } 2136 2137 static int narrow_write_error(struct r1bio *r1_bio, int i) 2138 { 2139 struct mddev *mddev = r1_bio->mddev; 2140 struct r1conf *conf = mddev->private; 2141 struct md_rdev *rdev = conf->mirrors[i].rdev; 2142 2143 /* bio has the data to be written to device 'i' where 2144 * we just recently had a write error. 2145 * We repeatedly clone the bio and trim down to one block, 2146 * then try the write. Where the write fails we record 2147 * a bad block. 2148 * It is conceivable that the bio doesn't exactly align with 2149 * blocks. We must handle this somehow. 2150 * 2151 * We currently own a reference on the rdev. 2152 */ 2153 2154 int block_sectors; 2155 sector_t sector; 2156 int sectors; 2157 int sect_to_write = r1_bio->sectors; 2158 int ok = 1; 2159 2160 if (rdev->badblocks.shift < 0) 2161 return 0; 2162 2163 block_sectors = roundup(1 << rdev->badblocks.shift, 2164 bdev_logical_block_size(rdev->bdev) >> 9); 2165 sector = r1_bio->sector; 2166 sectors = ((sector + block_sectors) 2167 & ~(sector_t)(block_sectors - 1)) 2168 - sector; 2169 2170 while (sect_to_write) { 2171 struct bio *wbio; 2172 if (sectors > sect_to_write) 2173 sectors = sect_to_write; 2174 /* Write at 'sector' for 'sectors'*/ 2175 2176 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 2177 unsigned vcnt = r1_bio->behind_page_count; 2178 struct bio_vec *vec = r1_bio->behind_bvecs; 2179 2180 while (!vec->bv_page) { 2181 vec++; 2182 vcnt--; 2183 } 2184 2185 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev); 2186 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec)); 2187 2188 wbio->bi_vcnt = vcnt; 2189 } else { 2190 wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); 2191 } 2192 2193 wbio->bi_rw = WRITE; 2194 wbio->bi_iter.bi_sector = r1_bio->sector; 2195 wbio->bi_iter.bi_size = r1_bio->sectors << 9; 2196 2197 bio_trim(wbio, sector - r1_bio->sector, sectors); 2198 wbio->bi_iter.bi_sector += rdev->data_offset; 2199 wbio->bi_bdev = rdev->bdev; 2200 if (submit_bio_wait(WRITE, wbio) == 0) 2201 /* failure! */ 2202 ok = rdev_set_badblocks(rdev, sector, 2203 sectors, 0) 2204 && ok; 2205 2206 bio_put(wbio); 2207 sect_to_write -= sectors; 2208 sector += sectors; 2209 sectors = block_sectors; 2210 } 2211 return ok; 2212 } 2213 2214 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2215 { 2216 int m; 2217 int s = r1_bio->sectors; 2218 for (m = 0; m < conf->raid_disks * 2 ; m++) { 2219 struct md_rdev *rdev = conf->mirrors[m].rdev; 2220 struct bio *bio = r1_bio->bios[m]; 2221 if (bio->bi_end_io == NULL) 2222 continue; 2223 if (!bio->bi_error && 2224 test_bit(R1BIO_MadeGood, &r1_bio->state)) { 2225 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0); 2226 } 2227 if (bio->bi_error && 2228 test_bit(R1BIO_WriteError, &r1_bio->state)) { 2229 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0)) 2230 md_error(conf->mddev, rdev); 2231 } 2232 } 2233 put_buf(r1_bio); 2234 md_done_sync(conf->mddev, s, 1); 2235 } 2236 2237 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2238 { 2239 int m; 2240 bool fail = false; 2241 for (m = 0; m < conf->raid_disks * 2 ; m++) 2242 if (r1_bio->bios[m] == IO_MADE_GOOD) { 2243 struct md_rdev *rdev = conf->mirrors[m].rdev; 2244 rdev_clear_badblocks(rdev, 2245 r1_bio->sector, 2246 r1_bio->sectors, 0); 2247 rdev_dec_pending(rdev, conf->mddev); 2248 } else if (r1_bio->bios[m] != NULL) { 2249 /* This drive got a write error. We need to 2250 * narrow down and record precise write 2251 * errors. 2252 */ 2253 fail = true; 2254 if (!narrow_write_error(r1_bio, m)) { 2255 md_error(conf->mddev, 2256 conf->mirrors[m].rdev); 2257 /* an I/O failed, we can't clear the bitmap */ 2258 set_bit(R1BIO_Degraded, &r1_bio->state); 2259 } 2260 rdev_dec_pending(conf->mirrors[m].rdev, 2261 conf->mddev); 2262 } 2263 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 2264 close_write(r1_bio); 2265 if (fail) { 2266 spin_lock_irq(&conf->device_lock); 2267 list_add(&r1_bio->retry_list, &conf->bio_end_io_list); 2268 spin_unlock_irq(&conf->device_lock); 2269 md_wakeup_thread(conf->mddev->thread); 2270 } else 2271 raid_end_bio_io(r1_bio); 2272 } 2273 2274 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio) 2275 { 2276 int disk; 2277 int max_sectors; 2278 struct mddev *mddev = conf->mddev; 2279 struct bio *bio; 2280 char b[BDEVNAME_SIZE]; 2281 struct md_rdev *rdev; 2282 2283 clear_bit(R1BIO_ReadError, &r1_bio->state); 2284 /* we got a read error. Maybe the drive is bad. Maybe just 2285 * the block and we can fix it. 2286 * We freeze all other IO, and try reading the block from 2287 * other devices. When we find one, we re-write 2288 * and check it that fixes the read error. 2289 * This is all done synchronously while the array is 2290 * frozen 2291 */ 2292 if (mddev->ro == 0) { 2293 freeze_array(conf, 1); 2294 fix_read_error(conf, r1_bio->read_disk, 2295 r1_bio->sector, r1_bio->sectors); 2296 unfreeze_array(conf); 2297 } else 2298 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); 2299 rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev); 2300 2301 bio = r1_bio->bios[r1_bio->read_disk]; 2302 bdevname(bio->bi_bdev, b); 2303 read_more: 2304 disk = read_balance(conf, r1_bio, &max_sectors); 2305 if (disk == -1) { 2306 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" 2307 " read error for block %llu\n", 2308 mdname(mddev), b, (unsigned long long)r1_bio->sector); 2309 raid_end_bio_io(r1_bio); 2310 } else { 2311 const unsigned long do_sync 2312 = r1_bio->master_bio->bi_rw & REQ_SYNC; 2313 if (bio) { 2314 r1_bio->bios[r1_bio->read_disk] = 2315 mddev->ro ? IO_BLOCKED : NULL; 2316 bio_put(bio); 2317 } 2318 r1_bio->read_disk = disk; 2319 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); 2320 bio_trim(bio, r1_bio->sector - bio->bi_iter.bi_sector, 2321 max_sectors); 2322 r1_bio->bios[r1_bio->read_disk] = bio; 2323 rdev = conf->mirrors[disk].rdev; 2324 printk_ratelimited(KERN_ERR 2325 "md/raid1:%s: redirecting sector %llu" 2326 " to other mirror: %s\n", 2327 mdname(mddev), 2328 (unsigned long long)r1_bio->sector, 2329 bdevname(rdev->bdev, b)); 2330 bio->bi_iter.bi_sector = r1_bio->sector + rdev->data_offset; 2331 bio->bi_bdev = rdev->bdev; 2332 bio->bi_end_io = raid1_end_read_request; 2333 bio->bi_rw = READ | do_sync; 2334 bio->bi_private = r1_bio; 2335 if (max_sectors < r1_bio->sectors) { 2336 /* Drat - have to split this up more */ 2337 struct bio *mbio = r1_bio->master_bio; 2338 int sectors_handled = (r1_bio->sector + max_sectors 2339 - mbio->bi_iter.bi_sector); 2340 r1_bio->sectors = max_sectors; 2341 spin_lock_irq(&conf->device_lock); 2342 if (mbio->bi_phys_segments == 0) 2343 mbio->bi_phys_segments = 2; 2344 else 2345 mbio->bi_phys_segments++; 2346 spin_unlock_irq(&conf->device_lock); 2347 generic_make_request(bio); 2348 bio = NULL; 2349 2350 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 2351 2352 r1_bio->master_bio = mbio; 2353 r1_bio->sectors = bio_sectors(mbio) - sectors_handled; 2354 r1_bio->state = 0; 2355 set_bit(R1BIO_ReadError, &r1_bio->state); 2356 r1_bio->mddev = mddev; 2357 r1_bio->sector = mbio->bi_iter.bi_sector + 2358 sectors_handled; 2359 2360 goto read_more; 2361 } else 2362 generic_make_request(bio); 2363 } 2364 } 2365 2366 static void raid1d(struct md_thread *thread) 2367 { 2368 struct mddev *mddev = thread->mddev; 2369 struct r1bio *r1_bio; 2370 unsigned long flags; 2371 struct r1conf *conf = mddev->private; 2372 struct list_head *head = &conf->retry_list; 2373 struct blk_plug plug; 2374 2375 md_check_recovery(mddev); 2376 2377 if (!list_empty_careful(&conf->bio_end_io_list) && 2378 !test_bit(MD_CHANGE_PENDING, &mddev->flags)) { 2379 LIST_HEAD(tmp); 2380 spin_lock_irqsave(&conf->device_lock, flags); 2381 if (!test_bit(MD_CHANGE_PENDING, &mddev->flags)) { 2382 list_add(&tmp, &conf->bio_end_io_list); 2383 list_del_init(&conf->bio_end_io_list); 2384 } 2385 spin_unlock_irqrestore(&conf->device_lock, flags); 2386 while (!list_empty(&tmp)) { 2387 r1_bio = list_first_entry(&conf->bio_end_io_list, 2388 struct r1bio, retry_list); 2389 list_del(&r1_bio->retry_list); 2390 raid_end_bio_io(r1_bio); 2391 } 2392 } 2393 2394 blk_start_plug(&plug); 2395 for (;;) { 2396 2397 flush_pending_writes(conf); 2398 2399 spin_lock_irqsave(&conf->device_lock, flags); 2400 if (list_empty(head)) { 2401 spin_unlock_irqrestore(&conf->device_lock, flags); 2402 break; 2403 } 2404 r1_bio = list_entry(head->prev, struct r1bio, retry_list); 2405 list_del(head->prev); 2406 conf->nr_queued--; 2407 spin_unlock_irqrestore(&conf->device_lock, flags); 2408 2409 mddev = r1_bio->mddev; 2410 conf = mddev->private; 2411 if (test_bit(R1BIO_IsSync, &r1_bio->state)) { 2412 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2413 test_bit(R1BIO_WriteError, &r1_bio->state)) 2414 handle_sync_write_finished(conf, r1_bio); 2415 else 2416 sync_request_write(mddev, r1_bio); 2417 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2418 test_bit(R1BIO_WriteError, &r1_bio->state)) 2419 handle_write_finished(conf, r1_bio); 2420 else if (test_bit(R1BIO_ReadError, &r1_bio->state)) 2421 handle_read_error(conf, r1_bio); 2422 else 2423 /* just a partial read to be scheduled from separate 2424 * context 2425 */ 2426 generic_make_request(r1_bio->bios[r1_bio->read_disk]); 2427 2428 cond_resched(); 2429 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) 2430 md_check_recovery(mddev); 2431 } 2432 blk_finish_plug(&plug); 2433 } 2434 2435 static int init_resync(struct r1conf *conf) 2436 { 2437 int buffs; 2438 2439 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; 2440 BUG_ON(conf->r1buf_pool); 2441 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, 2442 conf->poolinfo); 2443 if (!conf->r1buf_pool) 2444 return -ENOMEM; 2445 conf->next_resync = 0; 2446 return 0; 2447 } 2448 2449 /* 2450 * perform a "sync" on one "block" 2451 * 2452 * We need to make sure that no normal I/O request - particularly write 2453 * requests - conflict with active sync requests. 2454 * 2455 * This is achieved by tracking pending requests and a 'barrier' concept 2456 * that can be installed to exclude normal IO requests. 2457 */ 2458 2459 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped) 2460 { 2461 struct r1conf *conf = mddev->private; 2462 struct r1bio *r1_bio; 2463 struct bio *bio; 2464 sector_t max_sector, nr_sectors; 2465 int disk = -1; 2466 int i; 2467 int wonly = -1; 2468 int write_targets = 0, read_targets = 0; 2469 sector_t sync_blocks; 2470 int still_degraded = 0; 2471 int good_sectors = RESYNC_SECTORS; 2472 int min_bad = 0; /* number of sectors that are bad in all devices */ 2473 2474 if (!conf->r1buf_pool) 2475 if (init_resync(conf)) 2476 return 0; 2477 2478 max_sector = mddev->dev_sectors; 2479 if (sector_nr >= max_sector) { 2480 /* If we aborted, we need to abort the 2481 * sync on the 'current' bitmap chunk (there will 2482 * only be one in raid1 resync. 2483 * We can find the current addess in mddev->curr_resync 2484 */ 2485 if (mddev->curr_resync < max_sector) /* aborted */ 2486 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 2487 &sync_blocks, 1); 2488 else /* completed sync */ 2489 conf->fullsync = 0; 2490 2491 bitmap_close_sync(mddev->bitmap); 2492 close_sync(conf); 2493 2494 if (mddev_is_clustered(mddev)) { 2495 conf->cluster_sync_low = 0; 2496 conf->cluster_sync_high = 0; 2497 /* Send zeros to mark end of resync */ 2498 md_cluster_ops->resync_info_update(mddev, 0, 0); 2499 } 2500 return 0; 2501 } 2502 2503 if (mddev->bitmap == NULL && 2504 mddev->recovery_cp == MaxSector && 2505 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 2506 conf->fullsync == 0) { 2507 *skipped = 1; 2508 return max_sector - sector_nr; 2509 } 2510 /* before building a request, check if we can skip these blocks.. 2511 * This call the bitmap_start_sync doesn't actually record anything 2512 */ 2513 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 2514 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2515 /* We can skip this block, and probably several more */ 2516 *skipped = 1; 2517 return sync_blocks; 2518 } 2519 2520 /* we are incrementing sector_nr below. To be safe, we check against 2521 * sector_nr + two times RESYNC_SECTORS 2522 */ 2523 2524 bitmap_cond_end_sync(mddev->bitmap, sector_nr, 2525 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high)); 2526 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); 2527 2528 raise_barrier(conf, sector_nr); 2529 2530 rcu_read_lock(); 2531 /* 2532 * If we get a correctably read error during resync or recovery, 2533 * we might want to read from a different device. So we 2534 * flag all drives that could conceivably be read from for READ, 2535 * and any others (which will be non-In_sync devices) for WRITE. 2536 * If a read fails, we try reading from something else for which READ 2537 * is OK. 2538 */ 2539 2540 r1_bio->mddev = mddev; 2541 r1_bio->sector = sector_nr; 2542 r1_bio->state = 0; 2543 set_bit(R1BIO_IsSync, &r1_bio->state); 2544 2545 for (i = 0; i < conf->raid_disks * 2; i++) { 2546 struct md_rdev *rdev; 2547 bio = r1_bio->bios[i]; 2548 bio_reset(bio); 2549 2550 rdev = rcu_dereference(conf->mirrors[i].rdev); 2551 if (rdev == NULL || 2552 test_bit(Faulty, &rdev->flags)) { 2553 if (i < conf->raid_disks) 2554 still_degraded = 1; 2555 } else if (!test_bit(In_sync, &rdev->flags)) { 2556 bio->bi_rw = WRITE; 2557 bio->bi_end_io = end_sync_write; 2558 write_targets ++; 2559 } else { 2560 /* may need to read from here */ 2561 sector_t first_bad = MaxSector; 2562 int bad_sectors; 2563 2564 if (is_badblock(rdev, sector_nr, good_sectors, 2565 &first_bad, &bad_sectors)) { 2566 if (first_bad > sector_nr) 2567 good_sectors = first_bad - sector_nr; 2568 else { 2569 bad_sectors -= (sector_nr - first_bad); 2570 if (min_bad == 0 || 2571 min_bad > bad_sectors) 2572 min_bad = bad_sectors; 2573 } 2574 } 2575 if (sector_nr < first_bad) { 2576 if (test_bit(WriteMostly, &rdev->flags)) { 2577 if (wonly < 0) 2578 wonly = i; 2579 } else { 2580 if (disk < 0) 2581 disk = i; 2582 } 2583 bio->bi_rw = READ; 2584 bio->bi_end_io = end_sync_read; 2585 read_targets++; 2586 } else if (!test_bit(WriteErrorSeen, &rdev->flags) && 2587 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && 2588 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) { 2589 /* 2590 * The device is suitable for reading (InSync), 2591 * but has bad block(s) here. Let's try to correct them, 2592 * if we are doing resync or repair. Otherwise, leave 2593 * this device alone for this sync request. 2594 */ 2595 bio->bi_rw = WRITE; 2596 bio->bi_end_io = end_sync_write; 2597 write_targets++; 2598 } 2599 } 2600 if (bio->bi_end_io) { 2601 atomic_inc(&rdev->nr_pending); 2602 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset; 2603 bio->bi_bdev = rdev->bdev; 2604 bio->bi_private = r1_bio; 2605 } 2606 } 2607 rcu_read_unlock(); 2608 if (disk < 0) 2609 disk = wonly; 2610 r1_bio->read_disk = disk; 2611 2612 if (read_targets == 0 && min_bad > 0) { 2613 /* These sectors are bad on all InSync devices, so we 2614 * need to mark them bad on all write targets 2615 */ 2616 int ok = 1; 2617 for (i = 0 ; i < conf->raid_disks * 2 ; i++) 2618 if (r1_bio->bios[i]->bi_end_io == end_sync_write) { 2619 struct md_rdev *rdev = conf->mirrors[i].rdev; 2620 ok = rdev_set_badblocks(rdev, sector_nr, 2621 min_bad, 0 2622 ) && ok; 2623 } 2624 set_bit(MD_CHANGE_DEVS, &mddev->flags); 2625 *skipped = 1; 2626 put_buf(r1_bio); 2627 2628 if (!ok) { 2629 /* Cannot record the badblocks, so need to 2630 * abort the resync. 2631 * If there are multiple read targets, could just 2632 * fail the really bad ones ??? 2633 */ 2634 conf->recovery_disabled = mddev->recovery_disabled; 2635 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 2636 return 0; 2637 } else 2638 return min_bad; 2639 2640 } 2641 if (min_bad > 0 && min_bad < good_sectors) { 2642 /* only resync enough to reach the next bad->good 2643 * transition */ 2644 good_sectors = min_bad; 2645 } 2646 2647 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) 2648 /* extra read targets are also write targets */ 2649 write_targets += read_targets-1; 2650 2651 if (write_targets == 0 || read_targets == 0) { 2652 /* There is nowhere to write, so all non-sync 2653 * drives must be failed - so we are finished 2654 */ 2655 sector_t rv; 2656 if (min_bad > 0) 2657 max_sector = sector_nr + min_bad; 2658 rv = max_sector - sector_nr; 2659 *skipped = 1; 2660 put_buf(r1_bio); 2661 return rv; 2662 } 2663 2664 if (max_sector > mddev->resync_max) 2665 max_sector = mddev->resync_max; /* Don't do IO beyond here */ 2666 if (max_sector > sector_nr + good_sectors) 2667 max_sector = sector_nr + good_sectors; 2668 nr_sectors = 0; 2669 sync_blocks = 0; 2670 do { 2671 struct page *page; 2672 int len = PAGE_SIZE; 2673 if (sector_nr + (len>>9) > max_sector) 2674 len = (max_sector - sector_nr) << 9; 2675 if (len == 0) 2676 break; 2677 if (sync_blocks == 0) { 2678 if (!bitmap_start_sync(mddev->bitmap, sector_nr, 2679 &sync_blocks, still_degraded) && 2680 !conf->fullsync && 2681 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 2682 break; 2683 BUG_ON(sync_blocks < (PAGE_SIZE>>9)); 2684 if ((len >> 9) > sync_blocks) 2685 len = sync_blocks<<9; 2686 } 2687 2688 for (i = 0 ; i < conf->raid_disks * 2; i++) { 2689 bio = r1_bio->bios[i]; 2690 if (bio->bi_end_io) { 2691 page = bio->bi_io_vec[bio->bi_vcnt].bv_page; 2692 if (bio_add_page(bio, page, len, 0) == 0) { 2693 /* stop here */ 2694 bio->bi_io_vec[bio->bi_vcnt].bv_page = page; 2695 while (i > 0) { 2696 i--; 2697 bio = r1_bio->bios[i]; 2698 if (bio->bi_end_io==NULL) 2699 continue; 2700 /* remove last page from this bio */ 2701 bio->bi_vcnt--; 2702 bio->bi_iter.bi_size -= len; 2703 bio_clear_flag(bio, BIO_SEG_VALID); 2704 } 2705 goto bio_full; 2706 } 2707 } 2708 } 2709 nr_sectors += len>>9; 2710 sector_nr += len>>9; 2711 sync_blocks -= (len>>9); 2712 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); 2713 bio_full: 2714 r1_bio->sectors = nr_sectors; 2715 2716 if (mddev_is_clustered(mddev) && 2717 conf->cluster_sync_high < sector_nr + nr_sectors) { 2718 conf->cluster_sync_low = mddev->curr_resync_completed; 2719 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS; 2720 /* Send resync message */ 2721 md_cluster_ops->resync_info_update(mddev, 2722 conf->cluster_sync_low, 2723 conf->cluster_sync_high); 2724 } 2725 2726 /* For a user-requested sync, we read all readable devices and do a 2727 * compare 2728 */ 2729 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2730 atomic_set(&r1_bio->remaining, read_targets); 2731 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) { 2732 bio = r1_bio->bios[i]; 2733 if (bio->bi_end_io == end_sync_read) { 2734 read_targets--; 2735 md_sync_acct(bio->bi_bdev, nr_sectors); 2736 generic_make_request(bio); 2737 } 2738 } 2739 } else { 2740 atomic_set(&r1_bio->remaining, 1); 2741 bio = r1_bio->bios[r1_bio->read_disk]; 2742 md_sync_acct(bio->bi_bdev, nr_sectors); 2743 generic_make_request(bio); 2744 2745 } 2746 return nr_sectors; 2747 } 2748 2749 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks) 2750 { 2751 if (sectors) 2752 return sectors; 2753 2754 return mddev->dev_sectors; 2755 } 2756 2757 static struct r1conf *setup_conf(struct mddev *mddev) 2758 { 2759 struct r1conf *conf; 2760 int i; 2761 struct raid1_info *disk; 2762 struct md_rdev *rdev; 2763 int err = -ENOMEM; 2764 2765 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL); 2766 if (!conf) 2767 goto abort; 2768 2769 conf->mirrors = kzalloc(sizeof(struct raid1_info) 2770 * mddev->raid_disks * 2, 2771 GFP_KERNEL); 2772 if (!conf->mirrors) 2773 goto abort; 2774 2775 conf->tmppage = alloc_page(GFP_KERNEL); 2776 if (!conf->tmppage) 2777 goto abort; 2778 2779 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); 2780 if (!conf->poolinfo) 2781 goto abort; 2782 conf->poolinfo->raid_disks = mddev->raid_disks * 2; 2783 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2784 r1bio_pool_free, 2785 conf->poolinfo); 2786 if (!conf->r1bio_pool) 2787 goto abort; 2788 2789 conf->poolinfo->mddev = mddev; 2790 2791 err = -EINVAL; 2792 spin_lock_init(&conf->device_lock); 2793 rdev_for_each(rdev, mddev) { 2794 struct request_queue *q; 2795 int disk_idx = rdev->raid_disk; 2796 if (disk_idx >= mddev->raid_disks 2797 || disk_idx < 0) 2798 continue; 2799 if (test_bit(Replacement, &rdev->flags)) 2800 disk = conf->mirrors + mddev->raid_disks + disk_idx; 2801 else 2802 disk = conf->mirrors + disk_idx; 2803 2804 if (disk->rdev) 2805 goto abort; 2806 disk->rdev = rdev; 2807 q = bdev_get_queue(rdev->bdev); 2808 2809 disk->head_position = 0; 2810 disk->seq_start = MaxSector; 2811 } 2812 conf->raid_disks = mddev->raid_disks; 2813 conf->mddev = mddev; 2814 INIT_LIST_HEAD(&conf->retry_list); 2815 INIT_LIST_HEAD(&conf->bio_end_io_list); 2816 2817 spin_lock_init(&conf->resync_lock); 2818 init_waitqueue_head(&conf->wait_barrier); 2819 2820 bio_list_init(&conf->pending_bio_list); 2821 conf->pending_count = 0; 2822 conf->recovery_disabled = mddev->recovery_disabled - 1; 2823 2824 conf->start_next_window = MaxSector; 2825 conf->current_window_requests = conf->next_window_requests = 0; 2826 2827 err = -EIO; 2828 for (i = 0; i < conf->raid_disks * 2; i++) { 2829 2830 disk = conf->mirrors + i; 2831 2832 if (i < conf->raid_disks && 2833 disk[conf->raid_disks].rdev) { 2834 /* This slot has a replacement. */ 2835 if (!disk->rdev) { 2836 /* No original, just make the replacement 2837 * a recovering spare 2838 */ 2839 disk->rdev = 2840 disk[conf->raid_disks].rdev; 2841 disk[conf->raid_disks].rdev = NULL; 2842 } else if (!test_bit(In_sync, &disk->rdev->flags)) 2843 /* Original is not in_sync - bad */ 2844 goto abort; 2845 } 2846 2847 if (!disk->rdev || 2848 !test_bit(In_sync, &disk->rdev->flags)) { 2849 disk->head_position = 0; 2850 if (disk->rdev && 2851 (disk->rdev->saved_raid_disk < 0)) 2852 conf->fullsync = 1; 2853 } 2854 } 2855 2856 err = -ENOMEM; 2857 conf->thread = md_register_thread(raid1d, mddev, "raid1"); 2858 if (!conf->thread) { 2859 printk(KERN_ERR 2860 "md/raid1:%s: couldn't allocate thread\n", 2861 mdname(mddev)); 2862 goto abort; 2863 } 2864 2865 return conf; 2866 2867 abort: 2868 if (conf) { 2869 mempool_destroy(conf->r1bio_pool); 2870 kfree(conf->mirrors); 2871 safe_put_page(conf->tmppage); 2872 kfree(conf->poolinfo); 2873 kfree(conf); 2874 } 2875 return ERR_PTR(err); 2876 } 2877 2878 static void raid1_free(struct mddev *mddev, void *priv); 2879 static int run(struct mddev *mddev) 2880 { 2881 struct r1conf *conf; 2882 int i; 2883 struct md_rdev *rdev; 2884 int ret; 2885 bool discard_supported = false; 2886 2887 if (mddev->level != 1) { 2888 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n", 2889 mdname(mddev), mddev->level); 2890 return -EIO; 2891 } 2892 if (mddev->reshape_position != MaxSector) { 2893 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n", 2894 mdname(mddev)); 2895 return -EIO; 2896 } 2897 /* 2898 * copy the already verified devices into our private RAID1 2899 * bookkeeping area. [whatever we allocate in run(), 2900 * should be freed in raid1_free()] 2901 */ 2902 if (mddev->private == NULL) 2903 conf = setup_conf(mddev); 2904 else 2905 conf = mddev->private; 2906 2907 if (IS_ERR(conf)) 2908 return PTR_ERR(conf); 2909 2910 if (mddev->queue) 2911 blk_queue_max_write_same_sectors(mddev->queue, 0); 2912 2913 rdev_for_each(rdev, mddev) { 2914 if (!mddev->gendisk) 2915 continue; 2916 disk_stack_limits(mddev->gendisk, rdev->bdev, 2917 rdev->data_offset << 9); 2918 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 2919 discard_supported = true; 2920 } 2921 2922 mddev->degraded = 0; 2923 for (i=0; i < conf->raid_disks; i++) 2924 if (conf->mirrors[i].rdev == NULL || 2925 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || 2926 test_bit(Faulty, &conf->mirrors[i].rdev->flags)) 2927 mddev->degraded++; 2928 2929 if (conf->raid_disks - mddev->degraded == 1) 2930 mddev->recovery_cp = MaxSector; 2931 2932 if (mddev->recovery_cp != MaxSector) 2933 printk(KERN_NOTICE "md/raid1:%s: not clean" 2934 " -- starting background reconstruction\n", 2935 mdname(mddev)); 2936 printk(KERN_INFO 2937 "md/raid1:%s: active with %d out of %d mirrors\n", 2938 mdname(mddev), mddev->raid_disks - mddev->degraded, 2939 mddev->raid_disks); 2940 2941 /* 2942 * Ok, everything is just fine now 2943 */ 2944 mddev->thread = conf->thread; 2945 conf->thread = NULL; 2946 mddev->private = conf; 2947 2948 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); 2949 2950 if (mddev->queue) { 2951 if (discard_supported) 2952 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, 2953 mddev->queue); 2954 else 2955 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, 2956 mddev->queue); 2957 } 2958 2959 ret = md_integrity_register(mddev); 2960 if (ret) { 2961 md_unregister_thread(&mddev->thread); 2962 raid1_free(mddev, conf); 2963 } 2964 return ret; 2965 } 2966 2967 static void raid1_free(struct mddev *mddev, void *priv) 2968 { 2969 struct r1conf *conf = priv; 2970 2971 mempool_destroy(conf->r1bio_pool); 2972 kfree(conf->mirrors); 2973 safe_put_page(conf->tmppage); 2974 kfree(conf->poolinfo); 2975 kfree(conf); 2976 } 2977 2978 static int raid1_resize(struct mddev *mddev, sector_t sectors) 2979 { 2980 /* no resync is happening, and there is enough space 2981 * on all devices, so we can resize. 2982 * We need to make sure resync covers any new space. 2983 * If the array is shrinking we should possibly wait until 2984 * any io in the removed space completes, but it hardly seems 2985 * worth it. 2986 */ 2987 sector_t newsize = raid1_size(mddev, sectors, 0); 2988 if (mddev->external_size && 2989 mddev->array_sectors > newsize) 2990 return -EINVAL; 2991 if (mddev->bitmap) { 2992 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0); 2993 if (ret) 2994 return ret; 2995 } 2996 md_set_array_sectors(mddev, newsize); 2997 set_capacity(mddev->gendisk, mddev->array_sectors); 2998 revalidate_disk(mddev->gendisk); 2999 if (sectors > mddev->dev_sectors && 3000 mddev->recovery_cp > mddev->dev_sectors) { 3001 mddev->recovery_cp = mddev->dev_sectors; 3002 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3003 } 3004 mddev->dev_sectors = sectors; 3005 mddev->resync_max_sectors = sectors; 3006 return 0; 3007 } 3008 3009 static int raid1_reshape(struct mddev *mddev) 3010 { 3011 /* We need to: 3012 * 1/ resize the r1bio_pool 3013 * 2/ resize conf->mirrors 3014 * 3015 * We allocate a new r1bio_pool if we can. 3016 * Then raise a device barrier and wait until all IO stops. 3017 * Then resize conf->mirrors and swap in the new r1bio pool. 3018 * 3019 * At the same time, we "pack" the devices so that all the missing 3020 * devices have the higher raid_disk numbers. 3021 */ 3022 mempool_t *newpool, *oldpool; 3023 struct pool_info *newpoolinfo; 3024 struct raid1_info *newmirrors; 3025 struct r1conf *conf = mddev->private; 3026 int cnt, raid_disks; 3027 unsigned long flags; 3028 int d, d2, err; 3029 3030 /* Cannot change chunk_size, layout, or level */ 3031 if (mddev->chunk_sectors != mddev->new_chunk_sectors || 3032 mddev->layout != mddev->new_layout || 3033 mddev->level != mddev->new_level) { 3034 mddev->new_chunk_sectors = mddev->chunk_sectors; 3035 mddev->new_layout = mddev->layout; 3036 mddev->new_level = mddev->level; 3037 return -EINVAL; 3038 } 3039 3040 err = md_allow_write(mddev); 3041 if (err) 3042 return err; 3043 3044 raid_disks = mddev->raid_disks + mddev->delta_disks; 3045 3046 if (raid_disks < conf->raid_disks) { 3047 cnt=0; 3048 for (d= 0; d < conf->raid_disks; d++) 3049 if (conf->mirrors[d].rdev) 3050 cnt++; 3051 if (cnt > raid_disks) 3052 return -EBUSY; 3053 } 3054 3055 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); 3056 if (!newpoolinfo) 3057 return -ENOMEM; 3058 newpoolinfo->mddev = mddev; 3059 newpoolinfo->raid_disks = raid_disks * 2; 3060 3061 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 3062 r1bio_pool_free, newpoolinfo); 3063 if (!newpool) { 3064 kfree(newpoolinfo); 3065 return -ENOMEM; 3066 } 3067 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2, 3068 GFP_KERNEL); 3069 if (!newmirrors) { 3070 kfree(newpoolinfo); 3071 mempool_destroy(newpool); 3072 return -ENOMEM; 3073 } 3074 3075 freeze_array(conf, 0); 3076 3077 /* ok, everything is stopped */ 3078 oldpool = conf->r1bio_pool; 3079 conf->r1bio_pool = newpool; 3080 3081 for (d = d2 = 0; d < conf->raid_disks; d++) { 3082 struct md_rdev *rdev = conf->mirrors[d].rdev; 3083 if (rdev && rdev->raid_disk != d2) { 3084 sysfs_unlink_rdev(mddev, rdev); 3085 rdev->raid_disk = d2; 3086 sysfs_unlink_rdev(mddev, rdev); 3087 if (sysfs_link_rdev(mddev, rdev)) 3088 printk(KERN_WARNING 3089 "md/raid1:%s: cannot register rd%d\n", 3090 mdname(mddev), rdev->raid_disk); 3091 } 3092 if (rdev) 3093 newmirrors[d2++].rdev = rdev; 3094 } 3095 kfree(conf->mirrors); 3096 conf->mirrors = newmirrors; 3097 kfree(conf->poolinfo); 3098 conf->poolinfo = newpoolinfo; 3099 3100 spin_lock_irqsave(&conf->device_lock, flags); 3101 mddev->degraded += (raid_disks - conf->raid_disks); 3102 spin_unlock_irqrestore(&conf->device_lock, flags); 3103 conf->raid_disks = mddev->raid_disks = raid_disks; 3104 mddev->delta_disks = 0; 3105 3106 unfreeze_array(conf); 3107 3108 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery); 3109 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3110 md_wakeup_thread(mddev->thread); 3111 3112 mempool_destroy(oldpool); 3113 return 0; 3114 } 3115 3116 static void raid1_quiesce(struct mddev *mddev, int state) 3117 { 3118 struct r1conf *conf = mddev->private; 3119 3120 switch(state) { 3121 case 2: /* wake for suspend */ 3122 wake_up(&conf->wait_barrier); 3123 break; 3124 case 1: 3125 freeze_array(conf, 0); 3126 break; 3127 case 0: 3128 unfreeze_array(conf); 3129 break; 3130 } 3131 } 3132 3133 static void *raid1_takeover(struct mddev *mddev) 3134 { 3135 /* raid1 can take over: 3136 * raid5 with 2 devices, any layout or chunk size 3137 */ 3138 if (mddev->level == 5 && mddev->raid_disks == 2) { 3139 struct r1conf *conf; 3140 mddev->new_level = 1; 3141 mddev->new_layout = 0; 3142 mddev->new_chunk_sectors = 0; 3143 conf = setup_conf(mddev); 3144 if (!IS_ERR(conf)) 3145 /* Array must appear to be quiesced */ 3146 conf->array_frozen = 1; 3147 return conf; 3148 } 3149 return ERR_PTR(-EINVAL); 3150 } 3151 3152 static struct md_personality raid1_personality = 3153 { 3154 .name = "raid1", 3155 .level = 1, 3156 .owner = THIS_MODULE, 3157 .make_request = make_request, 3158 .run = run, 3159 .free = raid1_free, 3160 .status = status, 3161 .error_handler = error, 3162 .hot_add_disk = raid1_add_disk, 3163 .hot_remove_disk= raid1_remove_disk, 3164 .spare_active = raid1_spare_active, 3165 .sync_request = sync_request, 3166 .resize = raid1_resize, 3167 .size = raid1_size, 3168 .check_reshape = raid1_reshape, 3169 .quiesce = raid1_quiesce, 3170 .takeover = raid1_takeover, 3171 .congested = raid1_congested, 3172 }; 3173 3174 static int __init raid_init(void) 3175 { 3176 return register_md_personality(&raid1_personality); 3177 } 3178 3179 static void raid_exit(void) 3180 { 3181 unregister_md_personality(&raid1_personality); 3182 } 3183 3184 module_init(raid_init); 3185 module_exit(raid_exit); 3186 MODULE_LICENSE("GPL"); 3187 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); 3188 MODULE_ALIAS("md-personality-3"); /* RAID1 */ 3189 MODULE_ALIAS("md-raid1"); 3190 MODULE_ALIAS("md-level-1"); 3191 3192 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR); 3193