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