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); 70 static void lower_barrier(struct r1conf *conf); 71 72 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) 73 { 74 struct pool_info *pi = data; 75 int size = offsetof(struct r1bio, bios[pi->raid_disks]); 76 77 /* allocate a r1bio with room for raid_disks entries in the bios array */ 78 return kzalloc(size, gfp_flags); 79 } 80 81 static void r1bio_pool_free(void *r1_bio, void *data) 82 { 83 kfree(r1_bio); 84 } 85 86 #define RESYNC_BLOCK_SIZE (64*1024) 87 //#define RESYNC_BLOCK_SIZE PAGE_SIZE 88 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) 89 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) 90 #define RESYNC_WINDOW (2048*1024) 91 92 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) 93 { 94 struct pool_info *pi = data; 95 struct page *page; 96 struct r1bio *r1_bio; 97 struct bio *bio; 98 int i, j; 99 100 r1_bio = r1bio_pool_alloc(gfp_flags, pi); 101 if (!r1_bio) 102 return NULL; 103 104 /* 105 * Allocate bios : 1 for reading, n-1 for writing 106 */ 107 for (j = pi->raid_disks ; j-- ; ) { 108 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); 109 if (!bio) 110 goto out_free_bio; 111 r1_bio->bios[j] = bio; 112 } 113 /* 114 * Allocate RESYNC_PAGES data pages and attach them to 115 * the first bio. 116 * If this is a user-requested check/repair, allocate 117 * RESYNC_PAGES for each bio. 118 */ 119 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) 120 j = pi->raid_disks; 121 else 122 j = 1; 123 while(j--) { 124 bio = r1_bio->bios[j]; 125 for (i = 0; i < RESYNC_PAGES; i++) { 126 page = alloc_page(gfp_flags); 127 if (unlikely(!page)) 128 goto out_free_pages; 129 130 bio->bi_io_vec[i].bv_page = page; 131 bio->bi_vcnt = i+1; 132 } 133 } 134 /* If not user-requests, copy the page pointers to all bios */ 135 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { 136 for (i=0; i<RESYNC_PAGES ; i++) 137 for (j=1; j<pi->raid_disks; j++) 138 r1_bio->bios[j]->bi_io_vec[i].bv_page = 139 r1_bio->bios[0]->bi_io_vec[i].bv_page; 140 } 141 142 r1_bio->master_bio = NULL; 143 144 return r1_bio; 145 146 out_free_pages: 147 for (j=0 ; j < pi->raid_disks; j++) 148 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++) 149 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page); 150 j = -1; 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; 238 239 if (bio->bi_phys_segments) { 240 unsigned long flags; 241 spin_lock_irqsave(&conf->device_lock, flags); 242 bio->bi_phys_segments--; 243 done = (bio->bi_phys_segments == 0); 244 spin_unlock_irqrestore(&conf->device_lock, flags); 245 } else 246 done = 1; 247 248 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) 249 clear_bit(BIO_UPTODATE, &bio->bi_flags); 250 if (done) { 251 bio_endio(bio, 0); 252 /* 253 * Wake up any possible resync thread that waits for the device 254 * to go idle. 255 */ 256 allow_barrier(conf); 257 } 258 } 259 260 static void raid_end_bio_io(struct r1bio *r1_bio) 261 { 262 struct bio *bio = r1_bio->master_bio; 263 264 /* if nobody has done the final endio yet, do it now */ 265 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 266 pr_debug("raid1: sync end %s on sectors %llu-%llu\n", 267 (bio_data_dir(bio) == WRITE) ? "write" : "read", 268 (unsigned long long) bio->bi_sector, 269 (unsigned long long) bio->bi_sector + 270 (bio->bi_size >> 9) - 1); 271 272 call_bio_endio(r1_bio); 273 } 274 free_r1bio(r1_bio); 275 } 276 277 /* 278 * Update disk head position estimator based on IRQ completion info. 279 */ 280 static inline void update_head_pos(int disk, struct r1bio *r1_bio) 281 { 282 struct r1conf *conf = r1_bio->mddev->private; 283 284 conf->mirrors[disk].head_position = 285 r1_bio->sector + (r1_bio->sectors); 286 } 287 288 /* 289 * Find the disk number which triggered given bio 290 */ 291 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio) 292 { 293 int mirror; 294 struct r1conf *conf = r1_bio->mddev->private; 295 int raid_disks = conf->raid_disks; 296 297 for (mirror = 0; mirror < raid_disks * 2; mirror++) 298 if (r1_bio->bios[mirror] == bio) 299 break; 300 301 BUG_ON(mirror == raid_disks * 2); 302 update_head_pos(mirror, r1_bio); 303 304 return mirror; 305 } 306 307 static void raid1_end_read_request(struct bio *bio, int error) 308 { 309 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 310 struct r1bio *r1_bio = bio->bi_private; 311 int mirror; 312 struct r1conf *conf = r1_bio->mddev->private; 313 314 mirror = r1_bio->read_disk; 315 /* 316 * this branch is our 'one mirror IO has finished' event handler: 317 */ 318 update_head_pos(mirror, r1_bio); 319 320 if (uptodate) 321 set_bit(R1BIO_Uptodate, &r1_bio->state); 322 else { 323 /* If all other devices have failed, we want to return 324 * the error upwards rather than fail the last device. 325 * Here we redefine "uptodate" to mean "Don't want to retry" 326 */ 327 unsigned long flags; 328 spin_lock_irqsave(&conf->device_lock, flags); 329 if (r1_bio->mddev->degraded == conf->raid_disks || 330 (r1_bio->mddev->degraded == conf->raid_disks-1 && 331 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))) 332 uptodate = 1; 333 spin_unlock_irqrestore(&conf->device_lock, flags); 334 } 335 336 if (uptodate) { 337 raid_end_bio_io(r1_bio); 338 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); 339 } else { 340 /* 341 * oops, read error: 342 */ 343 char b[BDEVNAME_SIZE]; 344 printk_ratelimited( 345 KERN_ERR "md/raid1:%s: %s: " 346 "rescheduling sector %llu\n", 347 mdname(conf->mddev), 348 bdevname(conf->mirrors[mirror].rdev->bdev, 349 b), 350 (unsigned long long)r1_bio->sector); 351 set_bit(R1BIO_ReadError, &r1_bio->state); 352 reschedule_retry(r1_bio); 353 /* don't drop the reference on read_disk yet */ 354 } 355 } 356 357 static void close_write(struct r1bio *r1_bio) 358 { 359 /* it really is the end of this request */ 360 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 361 /* free extra copy of the data pages */ 362 int i = r1_bio->behind_page_count; 363 while (i--) 364 safe_put_page(r1_bio->behind_bvecs[i].bv_page); 365 kfree(r1_bio->behind_bvecs); 366 r1_bio->behind_bvecs = NULL; 367 } 368 /* clear the bitmap if all writes complete successfully */ 369 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, 370 r1_bio->sectors, 371 !test_bit(R1BIO_Degraded, &r1_bio->state), 372 test_bit(R1BIO_BehindIO, &r1_bio->state)); 373 md_write_end(r1_bio->mddev); 374 } 375 376 static void r1_bio_write_done(struct r1bio *r1_bio) 377 { 378 if (!atomic_dec_and_test(&r1_bio->remaining)) 379 return; 380 381 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 382 reschedule_retry(r1_bio); 383 else { 384 close_write(r1_bio); 385 if (test_bit(R1BIO_MadeGood, &r1_bio->state)) 386 reschedule_retry(r1_bio); 387 else 388 raid_end_bio_io(r1_bio); 389 } 390 } 391 392 static void raid1_end_write_request(struct bio *bio, int error) 393 { 394 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 395 struct r1bio *r1_bio = bio->bi_private; 396 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state); 397 struct r1conf *conf = r1_bio->mddev->private; 398 struct bio *to_put = NULL; 399 400 mirror = find_bio_disk(r1_bio, bio); 401 402 /* 403 * 'one mirror IO has finished' event handler: 404 */ 405 if (!uptodate) { 406 set_bit(WriteErrorSeen, 407 &conf->mirrors[mirror].rdev->flags); 408 if (!test_and_set_bit(WantReplacement, 409 &conf->mirrors[mirror].rdev->flags)) 410 set_bit(MD_RECOVERY_NEEDED, & 411 conf->mddev->recovery); 412 413 set_bit(R1BIO_WriteError, &r1_bio->state); 414 } else { 415 /* 416 * Set R1BIO_Uptodate in our master bio, so that we 417 * will return a good error code for to the higher 418 * levels even if IO on some other mirrored buffer 419 * fails. 420 * 421 * The 'master' represents the composite IO operation 422 * to user-side. So if something waits for IO, then it 423 * will wait for the 'master' bio. 424 */ 425 sector_t first_bad; 426 int bad_sectors; 427 428 r1_bio->bios[mirror] = NULL; 429 to_put = bio; 430 set_bit(R1BIO_Uptodate, &r1_bio->state); 431 432 /* Maybe we can clear some bad blocks. */ 433 if (is_badblock(conf->mirrors[mirror].rdev, 434 r1_bio->sector, r1_bio->sectors, 435 &first_bad, &bad_sectors)) { 436 r1_bio->bios[mirror] = IO_MADE_GOOD; 437 set_bit(R1BIO_MadeGood, &r1_bio->state); 438 } 439 } 440 441 if (behind) { 442 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) 443 atomic_dec(&r1_bio->behind_remaining); 444 445 /* 446 * In behind mode, we ACK the master bio once the I/O 447 * has safely reached all non-writemostly 448 * disks. Setting the Returned bit ensures that this 449 * gets done only once -- we don't ever want to return 450 * -EIO here, instead we'll wait 451 */ 452 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && 453 test_bit(R1BIO_Uptodate, &r1_bio->state)) { 454 /* Maybe we can return now */ 455 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 456 struct bio *mbio = r1_bio->master_bio; 457 pr_debug("raid1: behind end write sectors" 458 " %llu-%llu\n", 459 (unsigned long long) mbio->bi_sector, 460 (unsigned long long) mbio->bi_sector + 461 (mbio->bi_size >> 9) - 1); 462 call_bio_endio(r1_bio); 463 } 464 } 465 } 466 if (r1_bio->bios[mirror] == NULL) 467 rdev_dec_pending(conf->mirrors[mirror].rdev, 468 conf->mddev); 469 470 /* 471 * Let's see if all mirrored write operations have finished 472 * already. 473 */ 474 r1_bio_write_done(r1_bio); 475 476 if (to_put) 477 bio_put(to_put); 478 } 479 480 481 /* 482 * This routine returns the disk from which the requested read should 483 * be done. There is a per-array 'next expected sequential IO' sector 484 * number - if this matches on the next IO then we use the last disk. 485 * There is also a per-disk 'last know head position' sector that is 486 * maintained from IRQ contexts, both the normal and the resync IO 487 * completion handlers update this position correctly. If there is no 488 * perfect sequential match then we pick the disk whose head is closest. 489 * 490 * If there are 2 mirrors in the same 2 devices, performance degrades 491 * because position is mirror, not device based. 492 * 493 * The rdev for the device selected will have nr_pending incremented. 494 */ 495 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors) 496 { 497 const sector_t this_sector = r1_bio->sector; 498 int sectors; 499 int best_good_sectors; 500 int best_disk, best_dist_disk, best_pending_disk; 501 int has_nonrot_disk; 502 int disk; 503 sector_t best_dist; 504 unsigned int min_pending; 505 struct md_rdev *rdev; 506 int choose_first; 507 int choose_next_idle; 508 509 rcu_read_lock(); 510 /* 511 * Check if we can balance. We can balance on the whole 512 * device if no resync is going on, or below the resync window. 513 * We take the first readable disk when above the resync window. 514 */ 515 retry: 516 sectors = r1_bio->sectors; 517 best_disk = -1; 518 best_dist_disk = -1; 519 best_dist = MaxSector; 520 best_pending_disk = -1; 521 min_pending = UINT_MAX; 522 best_good_sectors = 0; 523 has_nonrot_disk = 0; 524 choose_next_idle = 0; 525 526 if (conf->mddev->recovery_cp < MaxSector && 527 (this_sector + sectors >= conf->next_resync)) 528 choose_first = 1; 529 else 530 choose_first = 0; 531 532 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { 533 sector_t dist; 534 sector_t first_bad; 535 int bad_sectors; 536 unsigned int pending; 537 bool nonrot; 538 539 rdev = rcu_dereference(conf->mirrors[disk].rdev); 540 if (r1_bio->bios[disk] == IO_BLOCKED 541 || rdev == NULL 542 || test_bit(Unmerged, &rdev->flags) 543 || test_bit(Faulty, &rdev->flags)) 544 continue; 545 if (!test_bit(In_sync, &rdev->flags) && 546 rdev->recovery_offset < this_sector + sectors) 547 continue; 548 if (test_bit(WriteMostly, &rdev->flags)) { 549 /* Don't balance among write-mostly, just 550 * use the first as a last resort */ 551 if (best_disk < 0) { 552 if (is_badblock(rdev, this_sector, sectors, 553 &first_bad, &bad_sectors)) { 554 if (first_bad < this_sector) 555 /* Cannot use this */ 556 continue; 557 best_good_sectors = first_bad - this_sector; 558 } else 559 best_good_sectors = sectors; 560 best_disk = disk; 561 } 562 continue; 563 } 564 /* This is a reasonable device to use. It might 565 * even be best. 566 */ 567 if (is_badblock(rdev, this_sector, sectors, 568 &first_bad, &bad_sectors)) { 569 if (best_dist < MaxSector) 570 /* already have a better device */ 571 continue; 572 if (first_bad <= this_sector) { 573 /* cannot read here. If this is the 'primary' 574 * device, then we must not read beyond 575 * bad_sectors from another device.. 576 */ 577 bad_sectors -= (this_sector - first_bad); 578 if (choose_first && sectors > bad_sectors) 579 sectors = bad_sectors; 580 if (best_good_sectors > sectors) 581 best_good_sectors = sectors; 582 583 } else { 584 sector_t good_sectors = first_bad - this_sector; 585 if (good_sectors > best_good_sectors) { 586 best_good_sectors = good_sectors; 587 best_disk = disk; 588 } 589 if (choose_first) 590 break; 591 } 592 continue; 593 } else 594 best_good_sectors = sectors; 595 596 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev)); 597 has_nonrot_disk |= nonrot; 598 pending = atomic_read(&rdev->nr_pending); 599 dist = abs(this_sector - conf->mirrors[disk].head_position); 600 if (choose_first) { 601 best_disk = disk; 602 break; 603 } 604 /* Don't change to another disk for sequential reads */ 605 if (conf->mirrors[disk].next_seq_sect == this_sector 606 || dist == 0) { 607 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9; 608 struct raid1_info *mirror = &conf->mirrors[disk]; 609 610 best_disk = disk; 611 /* 612 * If buffered sequential IO size exceeds optimal 613 * iosize, check if there is idle disk. If yes, choose 614 * the idle disk. read_balance could already choose an 615 * idle disk before noticing it's a sequential IO in 616 * this disk. This doesn't matter because this disk 617 * will idle, next time it will be utilized after the 618 * first disk has IO size exceeds optimal iosize. In 619 * this way, iosize of the first disk will be optimal 620 * iosize at least. iosize of the second disk might be 621 * small, but not a big deal since when the second disk 622 * starts IO, the first disk is likely still busy. 623 */ 624 if (nonrot && opt_iosize > 0 && 625 mirror->seq_start != MaxSector && 626 mirror->next_seq_sect > opt_iosize && 627 mirror->next_seq_sect - opt_iosize >= 628 mirror->seq_start) { 629 choose_next_idle = 1; 630 continue; 631 } 632 break; 633 } 634 /* If device is idle, use it */ 635 if (pending == 0) { 636 best_disk = disk; 637 break; 638 } 639 640 if (choose_next_idle) 641 continue; 642 643 if (min_pending > pending) { 644 min_pending = pending; 645 best_pending_disk = disk; 646 } 647 648 if (dist < best_dist) { 649 best_dist = dist; 650 best_dist_disk = disk; 651 } 652 } 653 654 /* 655 * If all disks are rotational, choose the closest disk. If any disk is 656 * non-rotational, choose the disk with less pending request even the 657 * disk is rotational, which might/might not be optimal for raids with 658 * mixed ratation/non-rotational disks depending on workload. 659 */ 660 if (best_disk == -1) { 661 if (has_nonrot_disk) 662 best_disk = best_pending_disk; 663 else 664 best_disk = best_dist_disk; 665 } 666 667 if (best_disk >= 0) { 668 rdev = rcu_dereference(conf->mirrors[best_disk].rdev); 669 if (!rdev) 670 goto retry; 671 atomic_inc(&rdev->nr_pending); 672 if (test_bit(Faulty, &rdev->flags)) { 673 /* cannot risk returning a device that failed 674 * before we inc'ed nr_pending 675 */ 676 rdev_dec_pending(rdev, conf->mddev); 677 goto retry; 678 } 679 sectors = best_good_sectors; 680 681 if (conf->mirrors[best_disk].next_seq_sect != this_sector) 682 conf->mirrors[best_disk].seq_start = this_sector; 683 684 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors; 685 } 686 rcu_read_unlock(); 687 *max_sectors = sectors; 688 689 return best_disk; 690 } 691 692 static int raid1_mergeable_bvec(struct request_queue *q, 693 struct bvec_merge_data *bvm, 694 struct bio_vec *biovec) 695 { 696 struct mddev *mddev = q->queuedata; 697 struct r1conf *conf = mddev->private; 698 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 699 int max = biovec->bv_len; 700 701 if (mddev->merge_check_needed) { 702 int disk; 703 rcu_read_lock(); 704 for (disk = 0; disk < conf->raid_disks * 2; disk++) { 705 struct md_rdev *rdev = rcu_dereference( 706 conf->mirrors[disk].rdev); 707 if (rdev && !test_bit(Faulty, &rdev->flags)) { 708 struct request_queue *q = 709 bdev_get_queue(rdev->bdev); 710 if (q->merge_bvec_fn) { 711 bvm->bi_sector = sector + 712 rdev->data_offset; 713 bvm->bi_bdev = rdev->bdev; 714 max = min(max, q->merge_bvec_fn( 715 q, bvm, biovec)); 716 } 717 } 718 } 719 rcu_read_unlock(); 720 } 721 return max; 722 723 } 724 725 int md_raid1_congested(struct mddev *mddev, int bits) 726 { 727 struct r1conf *conf = mddev->private; 728 int i, ret = 0; 729 730 if ((bits & (1 << BDI_async_congested)) && 731 conf->pending_count >= max_queued_requests) 732 return 1; 733 734 rcu_read_lock(); 735 for (i = 0; i < conf->raid_disks * 2; i++) { 736 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 737 if (rdev && !test_bit(Faulty, &rdev->flags)) { 738 struct request_queue *q = bdev_get_queue(rdev->bdev); 739 740 BUG_ON(!q); 741 742 /* Note the '|| 1' - when read_balance prefers 743 * non-congested targets, it can be removed 744 */ 745 if ((bits & (1<<BDI_async_congested)) || 1) 746 ret |= bdi_congested(&q->backing_dev_info, bits); 747 else 748 ret &= bdi_congested(&q->backing_dev_info, bits); 749 } 750 } 751 rcu_read_unlock(); 752 return ret; 753 } 754 EXPORT_SYMBOL_GPL(md_raid1_congested); 755 756 static int raid1_congested(void *data, int bits) 757 { 758 struct mddev *mddev = data; 759 760 return mddev_congested(mddev, bits) || 761 md_raid1_congested(mddev, bits); 762 } 763 764 static void flush_pending_writes(struct r1conf *conf) 765 { 766 /* Any writes that have been queued but are awaiting 767 * bitmap updates get flushed here. 768 */ 769 spin_lock_irq(&conf->device_lock); 770 771 if (conf->pending_bio_list.head) { 772 struct bio *bio; 773 bio = bio_list_get(&conf->pending_bio_list); 774 conf->pending_count = 0; 775 spin_unlock_irq(&conf->device_lock); 776 /* flush any pending bitmap writes to 777 * disk before proceeding w/ I/O */ 778 bitmap_unplug(conf->mddev->bitmap); 779 wake_up(&conf->wait_barrier); 780 781 while (bio) { /* submit pending writes */ 782 struct bio *next = bio->bi_next; 783 bio->bi_next = NULL; 784 if (unlikely((bio->bi_rw & REQ_DISCARD) && 785 !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) 786 /* Just ignore it */ 787 bio_endio(bio, 0); 788 else 789 generic_make_request(bio); 790 bio = next; 791 } 792 } else 793 spin_unlock_irq(&conf->device_lock); 794 } 795 796 /* Barriers.... 797 * Sometimes we need to suspend IO while we do something else, 798 * either some resync/recovery, or reconfigure the array. 799 * To do this we raise a 'barrier'. 800 * The 'barrier' is a counter that can be raised multiple times 801 * to count how many activities are happening which preclude 802 * normal IO. 803 * We can only raise the barrier if there is no pending IO. 804 * i.e. if nr_pending == 0. 805 * We choose only to raise the barrier if no-one is waiting for the 806 * barrier to go down. This means that as soon as an IO request 807 * is ready, no other operations which require a barrier will start 808 * until the IO request has had a chance. 809 * 810 * So: regular IO calls 'wait_barrier'. When that returns there 811 * is no backgroup IO happening, It must arrange to call 812 * allow_barrier when it has finished its IO. 813 * backgroup IO calls must call raise_barrier. Once that returns 814 * there is no normal IO happeing. It must arrange to call 815 * lower_barrier when the particular background IO completes. 816 */ 817 #define RESYNC_DEPTH 32 818 819 static void raise_barrier(struct r1conf *conf) 820 { 821 spin_lock_irq(&conf->resync_lock); 822 823 /* Wait until no block IO is waiting */ 824 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, 825 conf->resync_lock); 826 827 /* block any new IO from starting */ 828 conf->barrier++; 829 830 /* Now wait for all pending IO to complete */ 831 wait_event_lock_irq(conf->wait_barrier, 832 !conf->nr_pending && conf->barrier < RESYNC_DEPTH, 833 conf->resync_lock); 834 835 spin_unlock_irq(&conf->resync_lock); 836 } 837 838 static void lower_barrier(struct r1conf *conf) 839 { 840 unsigned long flags; 841 BUG_ON(conf->barrier <= 0); 842 spin_lock_irqsave(&conf->resync_lock, flags); 843 conf->barrier--; 844 spin_unlock_irqrestore(&conf->resync_lock, flags); 845 wake_up(&conf->wait_barrier); 846 } 847 848 static void wait_barrier(struct r1conf *conf) 849 { 850 spin_lock_irq(&conf->resync_lock); 851 if (conf->barrier) { 852 conf->nr_waiting++; 853 /* Wait for the barrier to drop. 854 * However if there are already pending 855 * requests (preventing the barrier from 856 * rising completely), and the 857 * pre-process bio queue isn't empty, 858 * then don't wait, as we need to empty 859 * that queue to get the nr_pending 860 * count down. 861 */ 862 wait_event_lock_irq(conf->wait_barrier, 863 !conf->barrier || 864 (conf->nr_pending && 865 current->bio_list && 866 !bio_list_empty(current->bio_list)), 867 conf->resync_lock); 868 conf->nr_waiting--; 869 } 870 conf->nr_pending++; 871 spin_unlock_irq(&conf->resync_lock); 872 } 873 874 static void allow_barrier(struct r1conf *conf) 875 { 876 unsigned long flags; 877 spin_lock_irqsave(&conf->resync_lock, flags); 878 conf->nr_pending--; 879 spin_unlock_irqrestore(&conf->resync_lock, flags); 880 wake_up(&conf->wait_barrier); 881 } 882 883 static void freeze_array(struct r1conf *conf) 884 { 885 /* stop syncio and normal IO and wait for everything to 886 * go quite. 887 * We increment barrier and nr_waiting, and then 888 * wait until nr_pending match nr_queued+1 889 * This is called in the context of one normal IO request 890 * that has failed. Thus any sync request that might be pending 891 * will be blocked by nr_pending, and we need to wait for 892 * pending IO requests to complete or be queued for re-try. 893 * Thus the number queued (nr_queued) plus this request (1) 894 * must match the number of pending IOs (nr_pending) before 895 * we continue. 896 */ 897 spin_lock_irq(&conf->resync_lock); 898 conf->barrier++; 899 conf->nr_waiting++; 900 wait_event_lock_irq_cmd(conf->wait_barrier, 901 conf->nr_pending == conf->nr_queued+1, 902 conf->resync_lock, 903 flush_pending_writes(conf)); 904 spin_unlock_irq(&conf->resync_lock); 905 } 906 static void unfreeze_array(struct r1conf *conf) 907 { 908 /* reverse the effect of the freeze */ 909 spin_lock_irq(&conf->resync_lock); 910 conf->barrier--; 911 conf->nr_waiting--; 912 wake_up(&conf->wait_barrier); 913 spin_unlock_irq(&conf->resync_lock); 914 } 915 916 917 /* duplicate the data pages for behind I/O 918 */ 919 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio) 920 { 921 int i; 922 struct bio_vec *bvec; 923 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), 924 GFP_NOIO); 925 if (unlikely(!bvecs)) 926 return; 927 928 bio_for_each_segment(bvec, bio, i) { 929 bvecs[i] = *bvec; 930 bvecs[i].bv_page = alloc_page(GFP_NOIO); 931 if (unlikely(!bvecs[i].bv_page)) 932 goto do_sync_io; 933 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset, 934 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); 935 kunmap(bvecs[i].bv_page); 936 kunmap(bvec->bv_page); 937 } 938 r1_bio->behind_bvecs = bvecs; 939 r1_bio->behind_page_count = bio->bi_vcnt; 940 set_bit(R1BIO_BehindIO, &r1_bio->state); 941 return; 942 943 do_sync_io: 944 for (i = 0; i < bio->bi_vcnt; i++) 945 if (bvecs[i].bv_page) 946 put_page(bvecs[i].bv_page); 947 kfree(bvecs); 948 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); 949 } 950 951 struct raid1_plug_cb { 952 struct blk_plug_cb cb; 953 struct bio_list pending; 954 int pending_cnt; 955 }; 956 957 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule) 958 { 959 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb, 960 cb); 961 struct mddev *mddev = plug->cb.data; 962 struct r1conf *conf = mddev->private; 963 struct bio *bio; 964 965 if (from_schedule || current->bio_list) { 966 spin_lock_irq(&conf->device_lock); 967 bio_list_merge(&conf->pending_bio_list, &plug->pending); 968 conf->pending_count += plug->pending_cnt; 969 spin_unlock_irq(&conf->device_lock); 970 md_wakeup_thread(mddev->thread); 971 kfree(plug); 972 return; 973 } 974 975 /* we aren't scheduling, so we can do the write-out directly. */ 976 bio = bio_list_get(&plug->pending); 977 bitmap_unplug(mddev->bitmap); 978 wake_up(&conf->wait_barrier); 979 980 while (bio) { /* submit pending writes */ 981 struct bio *next = bio->bi_next; 982 bio->bi_next = NULL; 983 generic_make_request(bio); 984 bio = next; 985 } 986 kfree(plug); 987 } 988 989 static void make_request(struct mddev *mddev, struct bio * bio) 990 { 991 struct r1conf *conf = mddev->private; 992 struct raid1_info *mirror; 993 struct r1bio *r1_bio; 994 struct bio *read_bio; 995 int i, disks; 996 struct bitmap *bitmap; 997 unsigned long flags; 998 const int rw = bio_data_dir(bio); 999 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); 1000 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA)); 1001 const unsigned long do_discard = (bio->bi_rw 1002 & (REQ_DISCARD | REQ_SECURE)); 1003 struct md_rdev *blocked_rdev; 1004 struct blk_plug_cb *cb; 1005 struct raid1_plug_cb *plug = NULL; 1006 int first_clone; 1007 int sectors_handled; 1008 int max_sectors; 1009 1010 /* 1011 * Register the new request and wait if the reconstruction 1012 * thread has put up a bar for new requests. 1013 * Continue immediately if no resync is active currently. 1014 */ 1015 1016 md_write_start(mddev, bio); /* wait on superblock update early */ 1017 1018 if (bio_data_dir(bio) == WRITE && 1019 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo && 1020 bio->bi_sector < mddev->suspend_hi) { 1021 /* As the suspend_* range is controlled by 1022 * userspace, we want an interruptible 1023 * wait. 1024 */ 1025 DEFINE_WAIT(w); 1026 for (;;) { 1027 flush_signals(current); 1028 prepare_to_wait(&conf->wait_barrier, 1029 &w, TASK_INTERRUPTIBLE); 1030 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo || 1031 bio->bi_sector >= mddev->suspend_hi) 1032 break; 1033 schedule(); 1034 } 1035 finish_wait(&conf->wait_barrier, &w); 1036 } 1037 1038 wait_barrier(conf); 1039 1040 bitmap = mddev->bitmap; 1041 1042 /* 1043 * make_request() can abort the operation when READA is being 1044 * used and no empty request is available. 1045 * 1046 */ 1047 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1048 1049 r1_bio->master_bio = bio; 1050 r1_bio->sectors = bio->bi_size >> 9; 1051 r1_bio->state = 0; 1052 r1_bio->mddev = mddev; 1053 r1_bio->sector = bio->bi_sector; 1054 1055 /* We might need to issue multiple reads to different 1056 * devices if there are bad blocks around, so we keep 1057 * track of the number of reads in bio->bi_phys_segments. 1058 * If this is 0, there is only one r1_bio and no locking 1059 * will be needed when requests complete. If it is 1060 * non-zero, then it is the number of not-completed requests. 1061 */ 1062 bio->bi_phys_segments = 0; 1063 clear_bit(BIO_SEG_VALID, &bio->bi_flags); 1064 1065 if (rw == READ) { 1066 /* 1067 * read balancing logic: 1068 */ 1069 int rdisk; 1070 1071 read_again: 1072 rdisk = read_balance(conf, r1_bio, &max_sectors); 1073 1074 if (rdisk < 0) { 1075 /* couldn't find anywhere to read from */ 1076 raid_end_bio_io(r1_bio); 1077 return; 1078 } 1079 mirror = conf->mirrors + rdisk; 1080 1081 if (test_bit(WriteMostly, &mirror->rdev->flags) && 1082 bitmap) { 1083 /* Reading from a write-mostly device must 1084 * take care not to over-take any writes 1085 * that are 'behind' 1086 */ 1087 wait_event(bitmap->behind_wait, 1088 atomic_read(&bitmap->behind_writes) == 0); 1089 } 1090 r1_bio->read_disk = rdisk; 1091 1092 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); 1093 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector, 1094 max_sectors); 1095 1096 r1_bio->bios[rdisk] = read_bio; 1097 1098 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; 1099 read_bio->bi_bdev = mirror->rdev->bdev; 1100 read_bio->bi_end_io = raid1_end_read_request; 1101 read_bio->bi_rw = READ | do_sync; 1102 read_bio->bi_private = r1_bio; 1103 1104 if (max_sectors < r1_bio->sectors) { 1105 /* could not read all from this device, so we will 1106 * need another r1_bio. 1107 */ 1108 1109 sectors_handled = (r1_bio->sector + max_sectors 1110 - bio->bi_sector); 1111 r1_bio->sectors = max_sectors; 1112 spin_lock_irq(&conf->device_lock); 1113 if (bio->bi_phys_segments == 0) 1114 bio->bi_phys_segments = 2; 1115 else 1116 bio->bi_phys_segments++; 1117 spin_unlock_irq(&conf->device_lock); 1118 /* Cannot call generic_make_request directly 1119 * as that will be queued in __make_request 1120 * and subsequent mempool_alloc might block waiting 1121 * for it. So hand bio over to raid1d. 1122 */ 1123 reschedule_retry(r1_bio); 1124 1125 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1126 1127 r1_bio->master_bio = bio; 1128 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled; 1129 r1_bio->state = 0; 1130 r1_bio->mddev = mddev; 1131 r1_bio->sector = bio->bi_sector + sectors_handled; 1132 goto read_again; 1133 } else 1134 generic_make_request(read_bio); 1135 return; 1136 } 1137 1138 /* 1139 * WRITE: 1140 */ 1141 if (conf->pending_count >= max_queued_requests) { 1142 md_wakeup_thread(mddev->thread); 1143 wait_event(conf->wait_barrier, 1144 conf->pending_count < max_queued_requests); 1145 } 1146 /* first select target devices under rcu_lock and 1147 * inc refcount on their rdev. Record them by setting 1148 * bios[x] to bio 1149 * If there are known/acknowledged bad blocks on any device on 1150 * which we have seen a write error, we want to avoid writing those 1151 * blocks. 1152 * This potentially requires several writes to write around 1153 * the bad blocks. Each set of writes gets it's own r1bio 1154 * with a set of bios attached. 1155 */ 1156 1157 disks = conf->raid_disks * 2; 1158 retry_write: 1159 blocked_rdev = NULL; 1160 rcu_read_lock(); 1161 max_sectors = r1_bio->sectors; 1162 for (i = 0; i < disks; i++) { 1163 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1164 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { 1165 atomic_inc(&rdev->nr_pending); 1166 blocked_rdev = rdev; 1167 break; 1168 } 1169 r1_bio->bios[i] = NULL; 1170 if (!rdev || test_bit(Faulty, &rdev->flags) 1171 || test_bit(Unmerged, &rdev->flags)) { 1172 if (i < conf->raid_disks) 1173 set_bit(R1BIO_Degraded, &r1_bio->state); 1174 continue; 1175 } 1176 1177 atomic_inc(&rdev->nr_pending); 1178 if (test_bit(WriteErrorSeen, &rdev->flags)) { 1179 sector_t first_bad; 1180 int bad_sectors; 1181 int is_bad; 1182 1183 is_bad = is_badblock(rdev, r1_bio->sector, 1184 max_sectors, 1185 &first_bad, &bad_sectors); 1186 if (is_bad < 0) { 1187 /* mustn't write here until the bad block is 1188 * acknowledged*/ 1189 set_bit(BlockedBadBlocks, &rdev->flags); 1190 blocked_rdev = rdev; 1191 break; 1192 } 1193 if (is_bad && first_bad <= r1_bio->sector) { 1194 /* Cannot write here at all */ 1195 bad_sectors -= (r1_bio->sector - first_bad); 1196 if (bad_sectors < max_sectors) 1197 /* mustn't write more than bad_sectors 1198 * to other devices yet 1199 */ 1200 max_sectors = bad_sectors; 1201 rdev_dec_pending(rdev, mddev); 1202 /* We don't set R1BIO_Degraded as that 1203 * only applies if the disk is 1204 * missing, so it might be re-added, 1205 * and we want to know to recover this 1206 * chunk. 1207 * In this case the device is here, 1208 * and the fact that this chunk is not 1209 * in-sync is recorded in the bad 1210 * block log 1211 */ 1212 continue; 1213 } 1214 if (is_bad) { 1215 int good_sectors = first_bad - r1_bio->sector; 1216 if (good_sectors < max_sectors) 1217 max_sectors = good_sectors; 1218 } 1219 } 1220 r1_bio->bios[i] = bio; 1221 } 1222 rcu_read_unlock(); 1223 1224 if (unlikely(blocked_rdev)) { 1225 /* Wait for this device to become unblocked */ 1226 int j; 1227 1228 for (j = 0; j < i; j++) 1229 if (r1_bio->bios[j]) 1230 rdev_dec_pending(conf->mirrors[j].rdev, mddev); 1231 r1_bio->state = 0; 1232 allow_barrier(conf); 1233 md_wait_for_blocked_rdev(blocked_rdev, mddev); 1234 wait_barrier(conf); 1235 goto retry_write; 1236 } 1237 1238 if (max_sectors < r1_bio->sectors) { 1239 /* We are splitting this write into multiple parts, so 1240 * we need to prepare for allocating another r1_bio. 1241 */ 1242 r1_bio->sectors = max_sectors; 1243 spin_lock_irq(&conf->device_lock); 1244 if (bio->bi_phys_segments == 0) 1245 bio->bi_phys_segments = 2; 1246 else 1247 bio->bi_phys_segments++; 1248 spin_unlock_irq(&conf->device_lock); 1249 } 1250 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector; 1251 1252 atomic_set(&r1_bio->remaining, 1); 1253 atomic_set(&r1_bio->behind_remaining, 0); 1254 1255 first_clone = 1; 1256 for (i = 0; i < disks; i++) { 1257 struct bio *mbio; 1258 if (!r1_bio->bios[i]) 1259 continue; 1260 1261 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); 1262 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors); 1263 1264 if (first_clone) { 1265 /* do behind I/O ? 1266 * Not if there are too many, or cannot 1267 * allocate memory, or a reader on WriteMostly 1268 * is waiting for behind writes to flush */ 1269 if (bitmap && 1270 (atomic_read(&bitmap->behind_writes) 1271 < mddev->bitmap_info.max_write_behind) && 1272 !waitqueue_active(&bitmap->behind_wait)) 1273 alloc_behind_pages(mbio, r1_bio); 1274 1275 bitmap_startwrite(bitmap, r1_bio->sector, 1276 r1_bio->sectors, 1277 test_bit(R1BIO_BehindIO, 1278 &r1_bio->state)); 1279 first_clone = 0; 1280 } 1281 if (r1_bio->behind_bvecs) { 1282 struct bio_vec *bvec; 1283 int j; 1284 1285 /* Yes, I really want the '__' version so that 1286 * we clear any unused pointer in the io_vec, rather 1287 * than leave them unchanged. This is important 1288 * because when we come to free the pages, we won't 1289 * know the original bi_idx, so we just free 1290 * them all 1291 */ 1292 __bio_for_each_segment(bvec, mbio, j, 0) 1293 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page; 1294 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) 1295 atomic_inc(&r1_bio->behind_remaining); 1296 } 1297 1298 r1_bio->bios[i] = mbio; 1299 1300 mbio->bi_sector = (r1_bio->sector + 1301 conf->mirrors[i].rdev->data_offset); 1302 mbio->bi_bdev = conf->mirrors[i].rdev->bdev; 1303 mbio->bi_end_io = raid1_end_write_request; 1304 mbio->bi_rw = WRITE | do_flush_fua | do_sync | do_discard; 1305 mbio->bi_private = r1_bio; 1306 1307 atomic_inc(&r1_bio->remaining); 1308 1309 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug)); 1310 if (cb) 1311 plug = container_of(cb, struct raid1_plug_cb, cb); 1312 else 1313 plug = NULL; 1314 spin_lock_irqsave(&conf->device_lock, flags); 1315 if (plug) { 1316 bio_list_add(&plug->pending, mbio); 1317 plug->pending_cnt++; 1318 } else { 1319 bio_list_add(&conf->pending_bio_list, mbio); 1320 conf->pending_count++; 1321 } 1322 spin_unlock_irqrestore(&conf->device_lock, flags); 1323 if (!plug) 1324 md_wakeup_thread(mddev->thread); 1325 } 1326 /* Mustn't call r1_bio_write_done before this next test, 1327 * as it could result in the bio being freed. 1328 */ 1329 if (sectors_handled < (bio->bi_size >> 9)) { 1330 r1_bio_write_done(r1_bio); 1331 /* We need another r1_bio. It has already been counted 1332 * in bio->bi_phys_segments 1333 */ 1334 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 1335 r1_bio->master_bio = bio; 1336 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled; 1337 r1_bio->state = 0; 1338 r1_bio->mddev = mddev; 1339 r1_bio->sector = bio->bi_sector + sectors_handled; 1340 goto retry_write; 1341 } 1342 1343 r1_bio_write_done(r1_bio); 1344 1345 /* In case raid1d snuck in to freeze_array */ 1346 wake_up(&conf->wait_barrier); 1347 } 1348 1349 static void status(struct seq_file *seq, struct mddev *mddev) 1350 { 1351 struct r1conf *conf = mddev->private; 1352 int i; 1353 1354 seq_printf(seq, " [%d/%d] [", conf->raid_disks, 1355 conf->raid_disks - mddev->degraded); 1356 rcu_read_lock(); 1357 for (i = 0; i < conf->raid_disks; i++) { 1358 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1359 seq_printf(seq, "%s", 1360 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); 1361 } 1362 rcu_read_unlock(); 1363 seq_printf(seq, "]"); 1364 } 1365 1366 1367 static void error(struct mddev *mddev, struct md_rdev *rdev) 1368 { 1369 char b[BDEVNAME_SIZE]; 1370 struct r1conf *conf = mddev->private; 1371 1372 /* 1373 * If it is not operational, then we have already marked it as dead 1374 * else if it is the last working disks, ignore the error, let the 1375 * next level up know. 1376 * else mark the drive as failed 1377 */ 1378 if (test_bit(In_sync, &rdev->flags) 1379 && (conf->raid_disks - mddev->degraded) == 1) { 1380 /* 1381 * Don't fail the drive, act as though we were just a 1382 * normal single drive. 1383 * However don't try a recovery from this drive as 1384 * it is very likely to fail. 1385 */ 1386 conf->recovery_disabled = mddev->recovery_disabled; 1387 return; 1388 } 1389 set_bit(Blocked, &rdev->flags); 1390 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1391 unsigned long flags; 1392 spin_lock_irqsave(&conf->device_lock, flags); 1393 mddev->degraded++; 1394 set_bit(Faulty, &rdev->flags); 1395 spin_unlock_irqrestore(&conf->device_lock, flags); 1396 /* 1397 * if recovery is running, make sure it aborts. 1398 */ 1399 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1400 } else 1401 set_bit(Faulty, &rdev->flags); 1402 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1403 printk(KERN_ALERT 1404 "md/raid1:%s: Disk failure on %s, disabling device.\n" 1405 "md/raid1:%s: Operation continuing on %d devices.\n", 1406 mdname(mddev), bdevname(rdev->bdev, b), 1407 mdname(mddev), conf->raid_disks - mddev->degraded); 1408 } 1409 1410 static void print_conf(struct r1conf *conf) 1411 { 1412 int i; 1413 1414 printk(KERN_DEBUG "RAID1 conf printout:\n"); 1415 if (!conf) { 1416 printk(KERN_DEBUG "(!conf)\n"); 1417 return; 1418 } 1419 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, 1420 conf->raid_disks); 1421 1422 rcu_read_lock(); 1423 for (i = 0; i < conf->raid_disks; i++) { 1424 char b[BDEVNAME_SIZE]; 1425 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); 1426 if (rdev) 1427 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", 1428 i, !test_bit(In_sync, &rdev->flags), 1429 !test_bit(Faulty, &rdev->flags), 1430 bdevname(rdev->bdev,b)); 1431 } 1432 rcu_read_unlock(); 1433 } 1434 1435 static void close_sync(struct r1conf *conf) 1436 { 1437 wait_barrier(conf); 1438 allow_barrier(conf); 1439 1440 mempool_destroy(conf->r1buf_pool); 1441 conf->r1buf_pool = NULL; 1442 } 1443 1444 static int raid1_spare_active(struct mddev *mddev) 1445 { 1446 int i; 1447 struct r1conf *conf = mddev->private; 1448 int count = 0; 1449 unsigned long flags; 1450 1451 /* 1452 * Find all failed disks within the RAID1 configuration 1453 * and mark them readable. 1454 * Called under mddev lock, so rcu protection not needed. 1455 */ 1456 for (i = 0; i < conf->raid_disks; i++) { 1457 struct md_rdev *rdev = conf->mirrors[i].rdev; 1458 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev; 1459 if (repl 1460 && repl->recovery_offset == MaxSector 1461 && !test_bit(Faulty, &repl->flags) 1462 && !test_and_set_bit(In_sync, &repl->flags)) { 1463 /* replacement has just become active */ 1464 if (!rdev || 1465 !test_and_clear_bit(In_sync, &rdev->flags)) 1466 count++; 1467 if (rdev) { 1468 /* Replaced device not technically 1469 * faulty, but we need to be sure 1470 * it gets removed and never re-added 1471 */ 1472 set_bit(Faulty, &rdev->flags); 1473 sysfs_notify_dirent_safe( 1474 rdev->sysfs_state); 1475 } 1476 } 1477 if (rdev 1478 && !test_bit(Faulty, &rdev->flags) 1479 && !test_and_set_bit(In_sync, &rdev->flags)) { 1480 count++; 1481 sysfs_notify_dirent_safe(rdev->sysfs_state); 1482 } 1483 } 1484 spin_lock_irqsave(&conf->device_lock, flags); 1485 mddev->degraded -= count; 1486 spin_unlock_irqrestore(&conf->device_lock, flags); 1487 1488 print_conf(conf); 1489 return count; 1490 } 1491 1492 1493 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev) 1494 { 1495 struct r1conf *conf = mddev->private; 1496 int err = -EEXIST; 1497 int mirror = 0; 1498 struct raid1_info *p; 1499 int first = 0; 1500 int last = conf->raid_disks - 1; 1501 struct request_queue *q = bdev_get_queue(rdev->bdev); 1502 1503 if (mddev->recovery_disabled == conf->recovery_disabled) 1504 return -EBUSY; 1505 1506 if (rdev->raid_disk >= 0) 1507 first = last = rdev->raid_disk; 1508 1509 if (q->merge_bvec_fn) { 1510 set_bit(Unmerged, &rdev->flags); 1511 mddev->merge_check_needed = 1; 1512 } 1513 1514 for (mirror = first; mirror <= last; mirror++) { 1515 p = conf->mirrors+mirror; 1516 if (!p->rdev) { 1517 1518 disk_stack_limits(mddev->gendisk, rdev->bdev, 1519 rdev->data_offset << 9); 1520 1521 p->head_position = 0; 1522 rdev->raid_disk = mirror; 1523 err = 0; 1524 /* As all devices are equivalent, we don't need a full recovery 1525 * if this was recently any drive of the array 1526 */ 1527 if (rdev->saved_raid_disk < 0) 1528 conf->fullsync = 1; 1529 rcu_assign_pointer(p->rdev, rdev); 1530 break; 1531 } 1532 if (test_bit(WantReplacement, &p->rdev->flags) && 1533 p[conf->raid_disks].rdev == NULL) { 1534 /* Add this device as a replacement */ 1535 clear_bit(In_sync, &rdev->flags); 1536 set_bit(Replacement, &rdev->flags); 1537 rdev->raid_disk = mirror; 1538 err = 0; 1539 conf->fullsync = 1; 1540 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev); 1541 break; 1542 } 1543 } 1544 if (err == 0 && test_bit(Unmerged, &rdev->flags)) { 1545 /* Some requests might not have seen this new 1546 * merge_bvec_fn. We must wait for them to complete 1547 * before merging the device fully. 1548 * First we make sure any code which has tested 1549 * our function has submitted the request, then 1550 * we wait for all outstanding requests to complete. 1551 */ 1552 synchronize_sched(); 1553 raise_barrier(conf); 1554 lower_barrier(conf); 1555 clear_bit(Unmerged, &rdev->flags); 1556 } 1557 md_integrity_add_rdev(rdev, mddev); 1558 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 1559 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 1560 print_conf(conf); 1561 return err; 1562 } 1563 1564 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev) 1565 { 1566 struct r1conf *conf = mddev->private; 1567 int err = 0; 1568 int number = rdev->raid_disk; 1569 struct raid1_info *p = conf->mirrors + number; 1570 1571 if (rdev != p->rdev) 1572 p = conf->mirrors + conf->raid_disks + number; 1573 1574 print_conf(conf); 1575 if (rdev == p->rdev) { 1576 if (test_bit(In_sync, &rdev->flags) || 1577 atomic_read(&rdev->nr_pending)) { 1578 err = -EBUSY; 1579 goto abort; 1580 } 1581 /* Only remove non-faulty devices if recovery 1582 * is not possible. 1583 */ 1584 if (!test_bit(Faulty, &rdev->flags) && 1585 mddev->recovery_disabled != conf->recovery_disabled && 1586 mddev->degraded < conf->raid_disks) { 1587 err = -EBUSY; 1588 goto abort; 1589 } 1590 p->rdev = NULL; 1591 synchronize_rcu(); 1592 if (atomic_read(&rdev->nr_pending)) { 1593 /* lost the race, try later */ 1594 err = -EBUSY; 1595 p->rdev = rdev; 1596 goto abort; 1597 } else if (conf->mirrors[conf->raid_disks + number].rdev) { 1598 /* We just removed a device that is being replaced. 1599 * Move down the replacement. We drain all IO before 1600 * doing this to avoid confusion. 1601 */ 1602 struct md_rdev *repl = 1603 conf->mirrors[conf->raid_disks + number].rdev; 1604 raise_barrier(conf); 1605 clear_bit(Replacement, &repl->flags); 1606 p->rdev = repl; 1607 conf->mirrors[conf->raid_disks + number].rdev = NULL; 1608 lower_barrier(conf); 1609 clear_bit(WantReplacement, &rdev->flags); 1610 } else 1611 clear_bit(WantReplacement, &rdev->flags); 1612 err = md_integrity_register(mddev); 1613 } 1614 abort: 1615 1616 print_conf(conf); 1617 return err; 1618 } 1619 1620 1621 static void end_sync_read(struct bio *bio, int error) 1622 { 1623 struct r1bio *r1_bio = bio->bi_private; 1624 1625 update_head_pos(r1_bio->read_disk, r1_bio); 1626 1627 /* 1628 * we have read a block, now it needs to be re-written, 1629 * or re-read if the read failed. 1630 * We don't do much here, just schedule handling by raid1d 1631 */ 1632 if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 1633 set_bit(R1BIO_Uptodate, &r1_bio->state); 1634 1635 if (atomic_dec_and_test(&r1_bio->remaining)) 1636 reschedule_retry(r1_bio); 1637 } 1638 1639 static void end_sync_write(struct bio *bio, int error) 1640 { 1641 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1642 struct r1bio *r1_bio = bio->bi_private; 1643 struct mddev *mddev = r1_bio->mddev; 1644 struct r1conf *conf = mddev->private; 1645 int mirror=0; 1646 sector_t first_bad; 1647 int bad_sectors; 1648 1649 mirror = find_bio_disk(r1_bio, bio); 1650 1651 if (!uptodate) { 1652 sector_t sync_blocks = 0; 1653 sector_t s = r1_bio->sector; 1654 long sectors_to_go = r1_bio->sectors; 1655 /* make sure these bits doesn't get cleared. */ 1656 do { 1657 bitmap_end_sync(mddev->bitmap, s, 1658 &sync_blocks, 1); 1659 s += sync_blocks; 1660 sectors_to_go -= sync_blocks; 1661 } while (sectors_to_go > 0); 1662 set_bit(WriteErrorSeen, 1663 &conf->mirrors[mirror].rdev->flags); 1664 if (!test_and_set_bit(WantReplacement, 1665 &conf->mirrors[mirror].rdev->flags)) 1666 set_bit(MD_RECOVERY_NEEDED, & 1667 mddev->recovery); 1668 set_bit(R1BIO_WriteError, &r1_bio->state); 1669 } else if (is_badblock(conf->mirrors[mirror].rdev, 1670 r1_bio->sector, 1671 r1_bio->sectors, 1672 &first_bad, &bad_sectors) && 1673 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev, 1674 r1_bio->sector, 1675 r1_bio->sectors, 1676 &first_bad, &bad_sectors) 1677 ) 1678 set_bit(R1BIO_MadeGood, &r1_bio->state); 1679 1680 if (atomic_dec_and_test(&r1_bio->remaining)) { 1681 int s = r1_bio->sectors; 1682 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 1683 test_bit(R1BIO_WriteError, &r1_bio->state)) 1684 reschedule_retry(r1_bio); 1685 else { 1686 put_buf(r1_bio); 1687 md_done_sync(mddev, s, uptodate); 1688 } 1689 } 1690 } 1691 1692 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector, 1693 int sectors, struct page *page, int rw) 1694 { 1695 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false)) 1696 /* success */ 1697 return 1; 1698 if (rw == WRITE) { 1699 set_bit(WriteErrorSeen, &rdev->flags); 1700 if (!test_and_set_bit(WantReplacement, 1701 &rdev->flags)) 1702 set_bit(MD_RECOVERY_NEEDED, & 1703 rdev->mddev->recovery); 1704 } 1705 /* need to record an error - either for the block or the device */ 1706 if (!rdev_set_badblocks(rdev, sector, sectors, 0)) 1707 md_error(rdev->mddev, rdev); 1708 return 0; 1709 } 1710 1711 static int fix_sync_read_error(struct r1bio *r1_bio) 1712 { 1713 /* Try some synchronous reads of other devices to get 1714 * good data, much like with normal read errors. Only 1715 * read into the pages we already have so we don't 1716 * need to re-issue the read request. 1717 * We don't need to freeze the array, because being in an 1718 * active sync request, there is no normal IO, and 1719 * no overlapping syncs. 1720 * We don't need to check is_badblock() again as we 1721 * made sure that anything with a bad block in range 1722 * will have bi_end_io clear. 1723 */ 1724 struct mddev *mddev = r1_bio->mddev; 1725 struct r1conf *conf = mddev->private; 1726 struct bio *bio = r1_bio->bios[r1_bio->read_disk]; 1727 sector_t sect = r1_bio->sector; 1728 int sectors = r1_bio->sectors; 1729 int idx = 0; 1730 1731 while(sectors) { 1732 int s = sectors; 1733 int d = r1_bio->read_disk; 1734 int success = 0; 1735 struct md_rdev *rdev; 1736 int start; 1737 1738 if (s > (PAGE_SIZE>>9)) 1739 s = PAGE_SIZE >> 9; 1740 do { 1741 if (r1_bio->bios[d]->bi_end_io == end_sync_read) { 1742 /* No rcu protection needed here devices 1743 * can only be removed when no resync is 1744 * active, and resync is currently active 1745 */ 1746 rdev = conf->mirrors[d].rdev; 1747 if (sync_page_io(rdev, sect, s<<9, 1748 bio->bi_io_vec[idx].bv_page, 1749 READ, false)) { 1750 success = 1; 1751 break; 1752 } 1753 } 1754 d++; 1755 if (d == conf->raid_disks * 2) 1756 d = 0; 1757 } while (!success && d != r1_bio->read_disk); 1758 1759 if (!success) { 1760 char b[BDEVNAME_SIZE]; 1761 int abort = 0; 1762 /* Cannot read from anywhere, this block is lost. 1763 * Record a bad block on each device. If that doesn't 1764 * work just disable and interrupt the recovery. 1765 * Don't fail devices as that won't really help. 1766 */ 1767 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error" 1768 " for block %llu\n", 1769 mdname(mddev), 1770 bdevname(bio->bi_bdev, b), 1771 (unsigned long long)r1_bio->sector); 1772 for (d = 0; d < conf->raid_disks * 2; d++) { 1773 rdev = conf->mirrors[d].rdev; 1774 if (!rdev || test_bit(Faulty, &rdev->flags)) 1775 continue; 1776 if (!rdev_set_badblocks(rdev, sect, s, 0)) 1777 abort = 1; 1778 } 1779 if (abort) { 1780 conf->recovery_disabled = 1781 mddev->recovery_disabled; 1782 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1783 md_done_sync(mddev, r1_bio->sectors, 0); 1784 put_buf(r1_bio); 1785 return 0; 1786 } 1787 /* Try next page */ 1788 sectors -= s; 1789 sect += s; 1790 idx++; 1791 continue; 1792 } 1793 1794 start = d; 1795 /* write it back and re-read */ 1796 while (d != r1_bio->read_disk) { 1797 if (d == 0) 1798 d = conf->raid_disks * 2; 1799 d--; 1800 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1801 continue; 1802 rdev = conf->mirrors[d].rdev; 1803 if (r1_sync_page_io(rdev, sect, s, 1804 bio->bi_io_vec[idx].bv_page, 1805 WRITE) == 0) { 1806 r1_bio->bios[d]->bi_end_io = NULL; 1807 rdev_dec_pending(rdev, mddev); 1808 } 1809 } 1810 d = start; 1811 while (d != r1_bio->read_disk) { 1812 if (d == 0) 1813 d = conf->raid_disks * 2; 1814 d--; 1815 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1816 continue; 1817 rdev = conf->mirrors[d].rdev; 1818 if (r1_sync_page_io(rdev, sect, s, 1819 bio->bi_io_vec[idx].bv_page, 1820 READ) != 0) 1821 atomic_add(s, &rdev->corrected_errors); 1822 } 1823 sectors -= s; 1824 sect += s; 1825 idx ++; 1826 } 1827 set_bit(R1BIO_Uptodate, &r1_bio->state); 1828 set_bit(BIO_UPTODATE, &bio->bi_flags); 1829 return 1; 1830 } 1831 1832 static int process_checks(struct r1bio *r1_bio) 1833 { 1834 /* We have read all readable devices. If we haven't 1835 * got the block, then there is no hope left. 1836 * If we have, then we want to do a comparison 1837 * and skip the write if everything is the same. 1838 * If any blocks failed to read, then we need to 1839 * attempt an over-write 1840 */ 1841 struct mddev *mddev = r1_bio->mddev; 1842 struct r1conf *conf = mddev->private; 1843 int primary; 1844 int i; 1845 int vcnt; 1846 1847 for (primary = 0; primary < conf->raid_disks * 2; primary++) 1848 if (r1_bio->bios[primary]->bi_end_io == end_sync_read && 1849 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { 1850 r1_bio->bios[primary]->bi_end_io = NULL; 1851 rdev_dec_pending(conf->mirrors[primary].rdev, mddev); 1852 break; 1853 } 1854 r1_bio->read_disk = primary; 1855 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); 1856 for (i = 0; i < conf->raid_disks * 2; i++) { 1857 int j; 1858 struct bio *pbio = r1_bio->bios[primary]; 1859 struct bio *sbio = r1_bio->bios[i]; 1860 int size; 1861 1862 if (r1_bio->bios[i]->bi_end_io != end_sync_read) 1863 continue; 1864 1865 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { 1866 for (j = vcnt; j-- ; ) { 1867 struct page *p, *s; 1868 p = pbio->bi_io_vec[j].bv_page; 1869 s = sbio->bi_io_vec[j].bv_page; 1870 if (memcmp(page_address(p), 1871 page_address(s), 1872 sbio->bi_io_vec[j].bv_len)) 1873 break; 1874 } 1875 } else 1876 j = 0; 1877 if (j >= 0) 1878 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches); 1879 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) 1880 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { 1881 /* No need to write to this device. */ 1882 sbio->bi_end_io = NULL; 1883 rdev_dec_pending(conf->mirrors[i].rdev, mddev); 1884 continue; 1885 } 1886 /* fixup the bio for reuse */ 1887 sbio->bi_vcnt = vcnt; 1888 sbio->bi_size = r1_bio->sectors << 9; 1889 sbio->bi_idx = 0; 1890 sbio->bi_phys_segments = 0; 1891 sbio->bi_flags &= ~(BIO_POOL_MASK - 1); 1892 sbio->bi_flags |= 1 << BIO_UPTODATE; 1893 sbio->bi_next = NULL; 1894 sbio->bi_sector = r1_bio->sector + 1895 conf->mirrors[i].rdev->data_offset; 1896 sbio->bi_bdev = conf->mirrors[i].rdev->bdev; 1897 size = sbio->bi_size; 1898 for (j = 0; j < vcnt ; j++) { 1899 struct bio_vec *bi; 1900 bi = &sbio->bi_io_vec[j]; 1901 bi->bv_offset = 0; 1902 if (size > PAGE_SIZE) 1903 bi->bv_len = PAGE_SIZE; 1904 else 1905 bi->bv_len = size; 1906 size -= PAGE_SIZE; 1907 memcpy(page_address(bi->bv_page), 1908 page_address(pbio->bi_io_vec[j].bv_page), 1909 PAGE_SIZE); 1910 } 1911 } 1912 return 0; 1913 } 1914 1915 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) 1916 { 1917 struct r1conf *conf = mddev->private; 1918 int i; 1919 int disks = conf->raid_disks * 2; 1920 struct bio *bio, *wbio; 1921 1922 bio = r1_bio->bios[r1_bio->read_disk]; 1923 1924 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) 1925 /* ouch - failed to read all of that. */ 1926 if (!fix_sync_read_error(r1_bio)) 1927 return; 1928 1929 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 1930 if (process_checks(r1_bio) < 0) 1931 return; 1932 /* 1933 * schedule writes 1934 */ 1935 atomic_set(&r1_bio->remaining, 1); 1936 for (i = 0; i < disks ; i++) { 1937 wbio = r1_bio->bios[i]; 1938 if (wbio->bi_end_io == NULL || 1939 (wbio->bi_end_io == end_sync_read && 1940 (i == r1_bio->read_disk || 1941 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) 1942 continue; 1943 1944 wbio->bi_rw = WRITE; 1945 wbio->bi_end_io = end_sync_write; 1946 atomic_inc(&r1_bio->remaining); 1947 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); 1948 1949 generic_make_request(wbio); 1950 } 1951 1952 if (atomic_dec_and_test(&r1_bio->remaining)) { 1953 /* if we're here, all write(s) have completed, so clean up */ 1954 int s = r1_bio->sectors; 1955 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 1956 test_bit(R1BIO_WriteError, &r1_bio->state)) 1957 reschedule_retry(r1_bio); 1958 else { 1959 put_buf(r1_bio); 1960 md_done_sync(mddev, s, 1); 1961 } 1962 } 1963 } 1964 1965 /* 1966 * This is a kernel thread which: 1967 * 1968 * 1. Retries failed read operations on working mirrors. 1969 * 2. Updates the raid superblock when problems encounter. 1970 * 3. Performs writes following reads for array synchronising. 1971 */ 1972 1973 static void fix_read_error(struct r1conf *conf, int read_disk, 1974 sector_t sect, int sectors) 1975 { 1976 struct mddev *mddev = conf->mddev; 1977 while(sectors) { 1978 int s = sectors; 1979 int d = read_disk; 1980 int success = 0; 1981 int start; 1982 struct md_rdev *rdev; 1983 1984 if (s > (PAGE_SIZE>>9)) 1985 s = PAGE_SIZE >> 9; 1986 1987 do { 1988 /* Note: no rcu protection needed here 1989 * as this is synchronous in the raid1d thread 1990 * which is the thread that might remove 1991 * a device. If raid1d ever becomes multi-threaded.... 1992 */ 1993 sector_t first_bad; 1994 int bad_sectors; 1995 1996 rdev = conf->mirrors[d].rdev; 1997 if (rdev && 1998 (test_bit(In_sync, &rdev->flags) || 1999 (!test_bit(Faulty, &rdev->flags) && 2000 rdev->recovery_offset >= sect + s)) && 2001 is_badblock(rdev, sect, s, 2002 &first_bad, &bad_sectors) == 0 && 2003 sync_page_io(rdev, sect, s<<9, 2004 conf->tmppage, READ, false)) 2005 success = 1; 2006 else { 2007 d++; 2008 if (d == conf->raid_disks * 2) 2009 d = 0; 2010 } 2011 } while (!success && d != read_disk); 2012 2013 if (!success) { 2014 /* Cannot read from anywhere - mark it bad */ 2015 struct md_rdev *rdev = conf->mirrors[read_disk].rdev; 2016 if (!rdev_set_badblocks(rdev, sect, s, 0)) 2017 md_error(mddev, rdev); 2018 break; 2019 } 2020 /* write it back and re-read */ 2021 start = d; 2022 while (d != read_disk) { 2023 if (d==0) 2024 d = conf->raid_disks * 2; 2025 d--; 2026 rdev = conf->mirrors[d].rdev; 2027 if (rdev && 2028 test_bit(In_sync, &rdev->flags)) 2029 r1_sync_page_io(rdev, sect, s, 2030 conf->tmppage, WRITE); 2031 } 2032 d = start; 2033 while (d != read_disk) { 2034 char b[BDEVNAME_SIZE]; 2035 if (d==0) 2036 d = conf->raid_disks * 2; 2037 d--; 2038 rdev = conf->mirrors[d].rdev; 2039 if (rdev && 2040 test_bit(In_sync, &rdev->flags)) { 2041 if (r1_sync_page_io(rdev, sect, s, 2042 conf->tmppage, READ)) { 2043 atomic_add(s, &rdev->corrected_errors); 2044 printk(KERN_INFO 2045 "md/raid1:%s: read error corrected " 2046 "(%d sectors at %llu on %s)\n", 2047 mdname(mddev), s, 2048 (unsigned long long)(sect + 2049 rdev->data_offset), 2050 bdevname(rdev->bdev, b)); 2051 } 2052 } 2053 } 2054 sectors -= s; 2055 sect += s; 2056 } 2057 } 2058 2059 static void bi_complete(struct bio *bio, int error) 2060 { 2061 complete((struct completion *)bio->bi_private); 2062 } 2063 2064 static int submit_bio_wait(int rw, struct bio *bio) 2065 { 2066 struct completion event; 2067 rw |= REQ_SYNC; 2068 2069 init_completion(&event); 2070 bio->bi_private = &event; 2071 bio->bi_end_io = bi_complete; 2072 submit_bio(rw, bio); 2073 wait_for_completion(&event); 2074 2075 return test_bit(BIO_UPTODATE, &bio->bi_flags); 2076 } 2077 2078 static int narrow_write_error(struct r1bio *r1_bio, int i) 2079 { 2080 struct mddev *mddev = r1_bio->mddev; 2081 struct r1conf *conf = mddev->private; 2082 struct md_rdev *rdev = conf->mirrors[i].rdev; 2083 int vcnt, idx; 2084 struct bio_vec *vec; 2085 2086 /* bio has the data to be written to device 'i' where 2087 * we just recently had a write error. 2088 * We repeatedly clone the bio and trim down to one block, 2089 * then try the write. Where the write fails we record 2090 * a bad block. 2091 * It is conceivable that the bio doesn't exactly align with 2092 * blocks. We must handle this somehow. 2093 * 2094 * We currently own a reference on the rdev. 2095 */ 2096 2097 int block_sectors; 2098 sector_t sector; 2099 int sectors; 2100 int sect_to_write = r1_bio->sectors; 2101 int ok = 1; 2102 2103 if (rdev->badblocks.shift < 0) 2104 return 0; 2105 2106 block_sectors = 1 << rdev->badblocks.shift; 2107 sector = r1_bio->sector; 2108 sectors = ((sector + block_sectors) 2109 & ~(sector_t)(block_sectors - 1)) 2110 - sector; 2111 2112 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 2113 vcnt = r1_bio->behind_page_count; 2114 vec = r1_bio->behind_bvecs; 2115 idx = 0; 2116 while (vec[idx].bv_page == NULL) 2117 idx++; 2118 } else { 2119 vcnt = r1_bio->master_bio->bi_vcnt; 2120 vec = r1_bio->master_bio->bi_io_vec; 2121 idx = r1_bio->master_bio->bi_idx; 2122 } 2123 while (sect_to_write) { 2124 struct bio *wbio; 2125 if (sectors > sect_to_write) 2126 sectors = sect_to_write; 2127 /* Write at 'sector' for 'sectors'*/ 2128 2129 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev); 2130 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec)); 2131 wbio->bi_sector = r1_bio->sector; 2132 wbio->bi_rw = WRITE; 2133 wbio->bi_vcnt = vcnt; 2134 wbio->bi_size = r1_bio->sectors << 9; 2135 wbio->bi_idx = idx; 2136 2137 md_trim_bio(wbio, sector - r1_bio->sector, sectors); 2138 wbio->bi_sector += rdev->data_offset; 2139 wbio->bi_bdev = rdev->bdev; 2140 if (submit_bio_wait(WRITE, wbio) == 0) 2141 /* failure! */ 2142 ok = rdev_set_badblocks(rdev, sector, 2143 sectors, 0) 2144 && ok; 2145 2146 bio_put(wbio); 2147 sect_to_write -= sectors; 2148 sector += sectors; 2149 sectors = block_sectors; 2150 } 2151 return ok; 2152 } 2153 2154 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2155 { 2156 int m; 2157 int s = r1_bio->sectors; 2158 for (m = 0; m < conf->raid_disks * 2 ; m++) { 2159 struct md_rdev *rdev = conf->mirrors[m].rdev; 2160 struct bio *bio = r1_bio->bios[m]; 2161 if (bio->bi_end_io == NULL) 2162 continue; 2163 if (test_bit(BIO_UPTODATE, &bio->bi_flags) && 2164 test_bit(R1BIO_MadeGood, &r1_bio->state)) { 2165 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0); 2166 } 2167 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && 2168 test_bit(R1BIO_WriteError, &r1_bio->state)) { 2169 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0)) 2170 md_error(conf->mddev, rdev); 2171 } 2172 } 2173 put_buf(r1_bio); 2174 md_done_sync(conf->mddev, s, 1); 2175 } 2176 2177 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio) 2178 { 2179 int m; 2180 for (m = 0; m < conf->raid_disks * 2 ; m++) 2181 if (r1_bio->bios[m] == IO_MADE_GOOD) { 2182 struct md_rdev *rdev = conf->mirrors[m].rdev; 2183 rdev_clear_badblocks(rdev, 2184 r1_bio->sector, 2185 r1_bio->sectors, 0); 2186 rdev_dec_pending(rdev, conf->mddev); 2187 } else if (r1_bio->bios[m] != NULL) { 2188 /* This drive got a write error. We need to 2189 * narrow down and record precise write 2190 * errors. 2191 */ 2192 if (!narrow_write_error(r1_bio, m)) { 2193 md_error(conf->mddev, 2194 conf->mirrors[m].rdev); 2195 /* an I/O failed, we can't clear the bitmap */ 2196 set_bit(R1BIO_Degraded, &r1_bio->state); 2197 } 2198 rdev_dec_pending(conf->mirrors[m].rdev, 2199 conf->mddev); 2200 } 2201 if (test_bit(R1BIO_WriteError, &r1_bio->state)) 2202 close_write(r1_bio); 2203 raid_end_bio_io(r1_bio); 2204 } 2205 2206 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio) 2207 { 2208 int disk; 2209 int max_sectors; 2210 struct mddev *mddev = conf->mddev; 2211 struct bio *bio; 2212 char b[BDEVNAME_SIZE]; 2213 struct md_rdev *rdev; 2214 2215 clear_bit(R1BIO_ReadError, &r1_bio->state); 2216 /* we got a read error. Maybe the drive is bad. Maybe just 2217 * the block and we can fix it. 2218 * We freeze all other IO, and try reading the block from 2219 * other devices. When we find one, we re-write 2220 * and check it that fixes the read error. 2221 * This is all done synchronously while the array is 2222 * frozen 2223 */ 2224 if (mddev->ro == 0) { 2225 freeze_array(conf); 2226 fix_read_error(conf, r1_bio->read_disk, 2227 r1_bio->sector, r1_bio->sectors); 2228 unfreeze_array(conf); 2229 } else 2230 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); 2231 rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev); 2232 2233 bio = r1_bio->bios[r1_bio->read_disk]; 2234 bdevname(bio->bi_bdev, b); 2235 read_more: 2236 disk = read_balance(conf, r1_bio, &max_sectors); 2237 if (disk == -1) { 2238 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" 2239 " read error for block %llu\n", 2240 mdname(mddev), b, (unsigned long long)r1_bio->sector); 2241 raid_end_bio_io(r1_bio); 2242 } else { 2243 const unsigned long do_sync 2244 = r1_bio->master_bio->bi_rw & REQ_SYNC; 2245 if (bio) { 2246 r1_bio->bios[r1_bio->read_disk] = 2247 mddev->ro ? IO_BLOCKED : NULL; 2248 bio_put(bio); 2249 } 2250 r1_bio->read_disk = disk; 2251 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); 2252 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors); 2253 r1_bio->bios[r1_bio->read_disk] = bio; 2254 rdev = conf->mirrors[disk].rdev; 2255 printk_ratelimited(KERN_ERR 2256 "md/raid1:%s: redirecting sector %llu" 2257 " to other mirror: %s\n", 2258 mdname(mddev), 2259 (unsigned long long)r1_bio->sector, 2260 bdevname(rdev->bdev, b)); 2261 bio->bi_sector = r1_bio->sector + rdev->data_offset; 2262 bio->bi_bdev = rdev->bdev; 2263 bio->bi_end_io = raid1_end_read_request; 2264 bio->bi_rw = READ | do_sync; 2265 bio->bi_private = r1_bio; 2266 if (max_sectors < r1_bio->sectors) { 2267 /* Drat - have to split this up more */ 2268 struct bio *mbio = r1_bio->master_bio; 2269 int sectors_handled = (r1_bio->sector + max_sectors 2270 - mbio->bi_sector); 2271 r1_bio->sectors = max_sectors; 2272 spin_lock_irq(&conf->device_lock); 2273 if (mbio->bi_phys_segments == 0) 2274 mbio->bi_phys_segments = 2; 2275 else 2276 mbio->bi_phys_segments++; 2277 spin_unlock_irq(&conf->device_lock); 2278 generic_make_request(bio); 2279 bio = NULL; 2280 2281 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 2282 2283 r1_bio->master_bio = mbio; 2284 r1_bio->sectors = (mbio->bi_size >> 9) 2285 - sectors_handled; 2286 r1_bio->state = 0; 2287 set_bit(R1BIO_ReadError, &r1_bio->state); 2288 r1_bio->mddev = mddev; 2289 r1_bio->sector = mbio->bi_sector + sectors_handled; 2290 2291 goto read_more; 2292 } else 2293 generic_make_request(bio); 2294 } 2295 } 2296 2297 static void raid1d(struct md_thread *thread) 2298 { 2299 struct mddev *mddev = thread->mddev; 2300 struct r1bio *r1_bio; 2301 unsigned long flags; 2302 struct r1conf *conf = mddev->private; 2303 struct list_head *head = &conf->retry_list; 2304 struct blk_plug plug; 2305 2306 md_check_recovery(mddev); 2307 2308 blk_start_plug(&plug); 2309 for (;;) { 2310 2311 flush_pending_writes(conf); 2312 2313 spin_lock_irqsave(&conf->device_lock, flags); 2314 if (list_empty(head)) { 2315 spin_unlock_irqrestore(&conf->device_lock, flags); 2316 break; 2317 } 2318 r1_bio = list_entry(head->prev, struct r1bio, retry_list); 2319 list_del(head->prev); 2320 conf->nr_queued--; 2321 spin_unlock_irqrestore(&conf->device_lock, flags); 2322 2323 mddev = r1_bio->mddev; 2324 conf = mddev->private; 2325 if (test_bit(R1BIO_IsSync, &r1_bio->state)) { 2326 if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2327 test_bit(R1BIO_WriteError, &r1_bio->state)) 2328 handle_sync_write_finished(conf, r1_bio); 2329 else 2330 sync_request_write(mddev, r1_bio); 2331 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) || 2332 test_bit(R1BIO_WriteError, &r1_bio->state)) 2333 handle_write_finished(conf, r1_bio); 2334 else if (test_bit(R1BIO_ReadError, &r1_bio->state)) 2335 handle_read_error(conf, r1_bio); 2336 else 2337 /* just a partial read to be scheduled from separate 2338 * context 2339 */ 2340 generic_make_request(r1_bio->bios[r1_bio->read_disk]); 2341 2342 cond_resched(); 2343 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) 2344 md_check_recovery(mddev); 2345 } 2346 blk_finish_plug(&plug); 2347 } 2348 2349 2350 static int init_resync(struct r1conf *conf) 2351 { 2352 int buffs; 2353 2354 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; 2355 BUG_ON(conf->r1buf_pool); 2356 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, 2357 conf->poolinfo); 2358 if (!conf->r1buf_pool) 2359 return -ENOMEM; 2360 conf->next_resync = 0; 2361 return 0; 2362 } 2363 2364 /* 2365 * perform a "sync" on one "block" 2366 * 2367 * We need to make sure that no normal I/O request - particularly write 2368 * requests - conflict with active sync requests. 2369 * 2370 * This is achieved by tracking pending requests and a 'barrier' concept 2371 * that can be installed to exclude normal IO requests. 2372 */ 2373 2374 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster) 2375 { 2376 struct r1conf *conf = mddev->private; 2377 struct r1bio *r1_bio; 2378 struct bio *bio; 2379 sector_t max_sector, nr_sectors; 2380 int disk = -1; 2381 int i; 2382 int wonly = -1; 2383 int write_targets = 0, read_targets = 0; 2384 sector_t sync_blocks; 2385 int still_degraded = 0; 2386 int good_sectors = RESYNC_SECTORS; 2387 int min_bad = 0; /* number of sectors that are bad in all devices */ 2388 2389 if (!conf->r1buf_pool) 2390 if (init_resync(conf)) 2391 return 0; 2392 2393 max_sector = mddev->dev_sectors; 2394 if (sector_nr >= max_sector) { 2395 /* If we aborted, we need to abort the 2396 * sync on the 'current' bitmap chunk (there will 2397 * only be one in raid1 resync. 2398 * We can find the current addess in mddev->curr_resync 2399 */ 2400 if (mddev->curr_resync < max_sector) /* aborted */ 2401 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 2402 &sync_blocks, 1); 2403 else /* completed sync */ 2404 conf->fullsync = 0; 2405 2406 bitmap_close_sync(mddev->bitmap); 2407 close_sync(conf); 2408 return 0; 2409 } 2410 2411 if (mddev->bitmap == NULL && 2412 mddev->recovery_cp == MaxSector && 2413 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 2414 conf->fullsync == 0) { 2415 *skipped = 1; 2416 return max_sector - sector_nr; 2417 } 2418 /* before building a request, check if we can skip these blocks.. 2419 * This call the bitmap_start_sync doesn't actually record anything 2420 */ 2421 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 2422 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2423 /* We can skip this block, and probably several more */ 2424 *skipped = 1; 2425 return sync_blocks; 2426 } 2427 /* 2428 * If there is non-resync activity waiting for a turn, 2429 * and resync is going fast enough, 2430 * then let it though before starting on this new sync request. 2431 */ 2432 if (!go_faster && conf->nr_waiting) 2433 msleep_interruptible(1000); 2434 2435 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 2436 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); 2437 raise_barrier(conf); 2438 2439 conf->next_resync = sector_nr; 2440 2441 rcu_read_lock(); 2442 /* 2443 * If we get a correctably read error during resync or recovery, 2444 * we might want to read from a different device. So we 2445 * flag all drives that could conceivably be read from for READ, 2446 * and any others (which will be non-In_sync devices) for WRITE. 2447 * If a read fails, we try reading from something else for which READ 2448 * is OK. 2449 */ 2450 2451 r1_bio->mddev = mddev; 2452 r1_bio->sector = sector_nr; 2453 r1_bio->state = 0; 2454 set_bit(R1BIO_IsSync, &r1_bio->state); 2455 2456 for (i = 0; i < conf->raid_disks * 2; i++) { 2457 struct md_rdev *rdev; 2458 bio = r1_bio->bios[i]; 2459 2460 /* take from bio_init */ 2461 bio->bi_next = NULL; 2462 bio->bi_flags &= ~(BIO_POOL_MASK-1); 2463 bio->bi_flags |= 1 << BIO_UPTODATE; 2464 bio->bi_rw = READ; 2465 bio->bi_vcnt = 0; 2466 bio->bi_idx = 0; 2467 bio->bi_phys_segments = 0; 2468 bio->bi_size = 0; 2469 bio->bi_end_io = NULL; 2470 bio->bi_private = NULL; 2471 2472 rdev = rcu_dereference(conf->mirrors[i].rdev); 2473 if (rdev == NULL || 2474 test_bit(Faulty, &rdev->flags)) { 2475 if (i < conf->raid_disks) 2476 still_degraded = 1; 2477 } else if (!test_bit(In_sync, &rdev->flags)) { 2478 bio->bi_rw = WRITE; 2479 bio->bi_end_io = end_sync_write; 2480 write_targets ++; 2481 } else { 2482 /* may need to read from here */ 2483 sector_t first_bad = MaxSector; 2484 int bad_sectors; 2485 2486 if (is_badblock(rdev, sector_nr, good_sectors, 2487 &first_bad, &bad_sectors)) { 2488 if (first_bad > sector_nr) 2489 good_sectors = first_bad - sector_nr; 2490 else { 2491 bad_sectors -= (sector_nr - first_bad); 2492 if (min_bad == 0 || 2493 min_bad > bad_sectors) 2494 min_bad = bad_sectors; 2495 } 2496 } 2497 if (sector_nr < first_bad) { 2498 if (test_bit(WriteMostly, &rdev->flags)) { 2499 if (wonly < 0) 2500 wonly = i; 2501 } else { 2502 if (disk < 0) 2503 disk = i; 2504 } 2505 bio->bi_rw = READ; 2506 bio->bi_end_io = end_sync_read; 2507 read_targets++; 2508 } else if (!test_bit(WriteErrorSeen, &rdev->flags) && 2509 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && 2510 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) { 2511 /* 2512 * The device is suitable for reading (InSync), 2513 * but has bad block(s) here. Let's try to correct them, 2514 * if we are doing resync or repair. Otherwise, leave 2515 * this device alone for this sync request. 2516 */ 2517 bio->bi_rw = WRITE; 2518 bio->bi_end_io = end_sync_write; 2519 write_targets++; 2520 } 2521 } 2522 if (bio->bi_end_io) { 2523 atomic_inc(&rdev->nr_pending); 2524 bio->bi_sector = sector_nr + rdev->data_offset; 2525 bio->bi_bdev = rdev->bdev; 2526 bio->bi_private = r1_bio; 2527 } 2528 } 2529 rcu_read_unlock(); 2530 if (disk < 0) 2531 disk = wonly; 2532 r1_bio->read_disk = disk; 2533 2534 if (read_targets == 0 && min_bad > 0) { 2535 /* These sectors are bad on all InSync devices, so we 2536 * need to mark them bad on all write targets 2537 */ 2538 int ok = 1; 2539 for (i = 0 ; i < conf->raid_disks * 2 ; i++) 2540 if (r1_bio->bios[i]->bi_end_io == end_sync_write) { 2541 struct md_rdev *rdev = conf->mirrors[i].rdev; 2542 ok = rdev_set_badblocks(rdev, sector_nr, 2543 min_bad, 0 2544 ) && ok; 2545 } 2546 set_bit(MD_CHANGE_DEVS, &mddev->flags); 2547 *skipped = 1; 2548 put_buf(r1_bio); 2549 2550 if (!ok) { 2551 /* Cannot record the badblocks, so need to 2552 * abort the resync. 2553 * If there are multiple read targets, could just 2554 * fail the really bad ones ??? 2555 */ 2556 conf->recovery_disabled = mddev->recovery_disabled; 2557 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 2558 return 0; 2559 } else 2560 return min_bad; 2561 2562 } 2563 if (min_bad > 0 && min_bad < good_sectors) { 2564 /* only resync enough to reach the next bad->good 2565 * transition */ 2566 good_sectors = min_bad; 2567 } 2568 2569 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) 2570 /* extra read targets are also write targets */ 2571 write_targets += read_targets-1; 2572 2573 if (write_targets == 0 || read_targets == 0) { 2574 /* There is nowhere to write, so all non-sync 2575 * drives must be failed - so we are finished 2576 */ 2577 sector_t rv; 2578 if (min_bad > 0) 2579 max_sector = sector_nr + min_bad; 2580 rv = max_sector - sector_nr; 2581 *skipped = 1; 2582 put_buf(r1_bio); 2583 return rv; 2584 } 2585 2586 if (max_sector > mddev->resync_max) 2587 max_sector = mddev->resync_max; /* Don't do IO beyond here */ 2588 if (max_sector > sector_nr + good_sectors) 2589 max_sector = sector_nr + good_sectors; 2590 nr_sectors = 0; 2591 sync_blocks = 0; 2592 do { 2593 struct page *page; 2594 int len = PAGE_SIZE; 2595 if (sector_nr + (len>>9) > max_sector) 2596 len = (max_sector - sector_nr) << 9; 2597 if (len == 0) 2598 break; 2599 if (sync_blocks == 0) { 2600 if (!bitmap_start_sync(mddev->bitmap, sector_nr, 2601 &sync_blocks, still_degraded) && 2602 !conf->fullsync && 2603 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 2604 break; 2605 BUG_ON(sync_blocks < (PAGE_SIZE>>9)); 2606 if ((len >> 9) > sync_blocks) 2607 len = sync_blocks<<9; 2608 } 2609 2610 for (i = 0 ; i < conf->raid_disks * 2; i++) { 2611 bio = r1_bio->bios[i]; 2612 if (bio->bi_end_io) { 2613 page = bio->bi_io_vec[bio->bi_vcnt].bv_page; 2614 if (bio_add_page(bio, page, len, 0) == 0) { 2615 /* stop here */ 2616 bio->bi_io_vec[bio->bi_vcnt].bv_page = page; 2617 while (i > 0) { 2618 i--; 2619 bio = r1_bio->bios[i]; 2620 if (bio->bi_end_io==NULL) 2621 continue; 2622 /* remove last page from this bio */ 2623 bio->bi_vcnt--; 2624 bio->bi_size -= len; 2625 bio->bi_flags &= ~(1<< BIO_SEG_VALID); 2626 } 2627 goto bio_full; 2628 } 2629 } 2630 } 2631 nr_sectors += len>>9; 2632 sector_nr += len>>9; 2633 sync_blocks -= (len>>9); 2634 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); 2635 bio_full: 2636 r1_bio->sectors = nr_sectors; 2637 2638 /* For a user-requested sync, we read all readable devices and do a 2639 * compare 2640 */ 2641 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 2642 atomic_set(&r1_bio->remaining, read_targets); 2643 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) { 2644 bio = r1_bio->bios[i]; 2645 if (bio->bi_end_io == end_sync_read) { 2646 read_targets--; 2647 md_sync_acct(bio->bi_bdev, nr_sectors); 2648 generic_make_request(bio); 2649 } 2650 } 2651 } else { 2652 atomic_set(&r1_bio->remaining, 1); 2653 bio = r1_bio->bios[r1_bio->read_disk]; 2654 md_sync_acct(bio->bi_bdev, nr_sectors); 2655 generic_make_request(bio); 2656 2657 } 2658 return nr_sectors; 2659 } 2660 2661 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks) 2662 { 2663 if (sectors) 2664 return sectors; 2665 2666 return mddev->dev_sectors; 2667 } 2668 2669 static struct r1conf *setup_conf(struct mddev *mddev) 2670 { 2671 struct r1conf *conf; 2672 int i; 2673 struct raid1_info *disk; 2674 struct md_rdev *rdev; 2675 int err = -ENOMEM; 2676 2677 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL); 2678 if (!conf) 2679 goto abort; 2680 2681 conf->mirrors = kzalloc(sizeof(struct raid1_info) 2682 * mddev->raid_disks * 2, 2683 GFP_KERNEL); 2684 if (!conf->mirrors) 2685 goto abort; 2686 2687 conf->tmppage = alloc_page(GFP_KERNEL); 2688 if (!conf->tmppage) 2689 goto abort; 2690 2691 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); 2692 if (!conf->poolinfo) 2693 goto abort; 2694 conf->poolinfo->raid_disks = mddev->raid_disks * 2; 2695 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2696 r1bio_pool_free, 2697 conf->poolinfo); 2698 if (!conf->r1bio_pool) 2699 goto abort; 2700 2701 conf->poolinfo->mddev = mddev; 2702 2703 err = -EINVAL; 2704 spin_lock_init(&conf->device_lock); 2705 rdev_for_each(rdev, mddev) { 2706 struct request_queue *q; 2707 int disk_idx = rdev->raid_disk; 2708 if (disk_idx >= mddev->raid_disks 2709 || disk_idx < 0) 2710 continue; 2711 if (test_bit(Replacement, &rdev->flags)) 2712 disk = conf->mirrors + mddev->raid_disks + disk_idx; 2713 else 2714 disk = conf->mirrors + disk_idx; 2715 2716 if (disk->rdev) 2717 goto abort; 2718 disk->rdev = rdev; 2719 q = bdev_get_queue(rdev->bdev); 2720 if (q->merge_bvec_fn) 2721 mddev->merge_check_needed = 1; 2722 2723 disk->head_position = 0; 2724 disk->seq_start = MaxSector; 2725 } 2726 conf->raid_disks = mddev->raid_disks; 2727 conf->mddev = mddev; 2728 INIT_LIST_HEAD(&conf->retry_list); 2729 2730 spin_lock_init(&conf->resync_lock); 2731 init_waitqueue_head(&conf->wait_barrier); 2732 2733 bio_list_init(&conf->pending_bio_list); 2734 conf->pending_count = 0; 2735 conf->recovery_disabled = mddev->recovery_disabled - 1; 2736 2737 err = -EIO; 2738 for (i = 0; i < conf->raid_disks * 2; i++) { 2739 2740 disk = conf->mirrors + i; 2741 2742 if (i < conf->raid_disks && 2743 disk[conf->raid_disks].rdev) { 2744 /* This slot has a replacement. */ 2745 if (!disk->rdev) { 2746 /* No original, just make the replacement 2747 * a recovering spare 2748 */ 2749 disk->rdev = 2750 disk[conf->raid_disks].rdev; 2751 disk[conf->raid_disks].rdev = NULL; 2752 } else if (!test_bit(In_sync, &disk->rdev->flags)) 2753 /* Original is not in_sync - bad */ 2754 goto abort; 2755 } 2756 2757 if (!disk->rdev || 2758 !test_bit(In_sync, &disk->rdev->flags)) { 2759 disk->head_position = 0; 2760 if (disk->rdev && 2761 (disk->rdev->saved_raid_disk < 0)) 2762 conf->fullsync = 1; 2763 } 2764 } 2765 2766 err = -ENOMEM; 2767 conf->thread = md_register_thread(raid1d, mddev, "raid1"); 2768 if (!conf->thread) { 2769 printk(KERN_ERR 2770 "md/raid1:%s: couldn't allocate thread\n", 2771 mdname(mddev)); 2772 goto abort; 2773 } 2774 2775 return conf; 2776 2777 abort: 2778 if (conf) { 2779 if (conf->r1bio_pool) 2780 mempool_destroy(conf->r1bio_pool); 2781 kfree(conf->mirrors); 2782 safe_put_page(conf->tmppage); 2783 kfree(conf->poolinfo); 2784 kfree(conf); 2785 } 2786 return ERR_PTR(err); 2787 } 2788 2789 static int stop(struct mddev *mddev); 2790 static int run(struct mddev *mddev) 2791 { 2792 struct r1conf *conf; 2793 int i; 2794 struct md_rdev *rdev; 2795 int ret; 2796 bool discard_supported = false; 2797 2798 if (mddev->level != 1) { 2799 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n", 2800 mdname(mddev), mddev->level); 2801 return -EIO; 2802 } 2803 if (mddev->reshape_position != MaxSector) { 2804 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n", 2805 mdname(mddev)); 2806 return -EIO; 2807 } 2808 /* 2809 * copy the already verified devices into our private RAID1 2810 * bookkeeping area. [whatever we allocate in run(), 2811 * should be freed in stop()] 2812 */ 2813 if (mddev->private == NULL) 2814 conf = setup_conf(mddev); 2815 else 2816 conf = mddev->private; 2817 2818 if (IS_ERR(conf)) 2819 return PTR_ERR(conf); 2820 2821 rdev_for_each(rdev, mddev) { 2822 if (!mddev->gendisk) 2823 continue; 2824 disk_stack_limits(mddev->gendisk, rdev->bdev, 2825 rdev->data_offset << 9); 2826 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 2827 discard_supported = true; 2828 } 2829 2830 mddev->degraded = 0; 2831 for (i=0; i < conf->raid_disks; i++) 2832 if (conf->mirrors[i].rdev == NULL || 2833 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || 2834 test_bit(Faulty, &conf->mirrors[i].rdev->flags)) 2835 mddev->degraded++; 2836 2837 if (conf->raid_disks - mddev->degraded == 1) 2838 mddev->recovery_cp = MaxSector; 2839 2840 if (mddev->recovery_cp != MaxSector) 2841 printk(KERN_NOTICE "md/raid1:%s: not clean" 2842 " -- starting background reconstruction\n", 2843 mdname(mddev)); 2844 printk(KERN_INFO 2845 "md/raid1:%s: active with %d out of %d mirrors\n", 2846 mdname(mddev), mddev->raid_disks - mddev->degraded, 2847 mddev->raid_disks); 2848 2849 /* 2850 * Ok, everything is just fine now 2851 */ 2852 mddev->thread = conf->thread; 2853 conf->thread = NULL; 2854 mddev->private = conf; 2855 2856 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); 2857 2858 if (mddev->queue) { 2859 mddev->queue->backing_dev_info.congested_fn = raid1_congested; 2860 mddev->queue->backing_dev_info.congested_data = mddev; 2861 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec); 2862 2863 if (discard_supported) 2864 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, 2865 mddev->queue); 2866 else 2867 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, 2868 mddev->queue); 2869 } 2870 2871 ret = md_integrity_register(mddev); 2872 if (ret) 2873 stop(mddev); 2874 return ret; 2875 } 2876 2877 static int stop(struct mddev *mddev) 2878 { 2879 struct r1conf *conf = mddev->private; 2880 struct bitmap *bitmap = mddev->bitmap; 2881 2882 /* wait for behind writes to complete */ 2883 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) { 2884 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n", 2885 mdname(mddev)); 2886 /* need to kick something here to make sure I/O goes? */ 2887 wait_event(bitmap->behind_wait, 2888 atomic_read(&bitmap->behind_writes) == 0); 2889 } 2890 2891 raise_barrier(conf); 2892 lower_barrier(conf); 2893 2894 md_unregister_thread(&mddev->thread); 2895 if (conf->r1bio_pool) 2896 mempool_destroy(conf->r1bio_pool); 2897 kfree(conf->mirrors); 2898 kfree(conf->poolinfo); 2899 kfree(conf); 2900 mddev->private = NULL; 2901 return 0; 2902 } 2903 2904 static int raid1_resize(struct mddev *mddev, sector_t sectors) 2905 { 2906 /* no resync is happening, and there is enough space 2907 * on all devices, so we can resize. 2908 * We need to make sure resync covers any new space. 2909 * If the array is shrinking we should possibly wait until 2910 * any io in the removed space completes, but it hardly seems 2911 * worth it. 2912 */ 2913 sector_t newsize = raid1_size(mddev, sectors, 0); 2914 if (mddev->external_size && 2915 mddev->array_sectors > newsize) 2916 return -EINVAL; 2917 if (mddev->bitmap) { 2918 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0); 2919 if (ret) 2920 return ret; 2921 } 2922 md_set_array_sectors(mddev, newsize); 2923 set_capacity(mddev->gendisk, mddev->array_sectors); 2924 revalidate_disk(mddev->gendisk); 2925 if (sectors > mddev->dev_sectors && 2926 mddev->recovery_cp > mddev->dev_sectors) { 2927 mddev->recovery_cp = mddev->dev_sectors; 2928 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 2929 } 2930 mddev->dev_sectors = sectors; 2931 mddev->resync_max_sectors = sectors; 2932 return 0; 2933 } 2934 2935 static int raid1_reshape(struct mddev *mddev) 2936 { 2937 /* We need to: 2938 * 1/ resize the r1bio_pool 2939 * 2/ resize conf->mirrors 2940 * 2941 * We allocate a new r1bio_pool if we can. 2942 * Then raise a device barrier and wait until all IO stops. 2943 * Then resize conf->mirrors and swap in the new r1bio pool. 2944 * 2945 * At the same time, we "pack" the devices so that all the missing 2946 * devices have the higher raid_disk numbers. 2947 */ 2948 mempool_t *newpool, *oldpool; 2949 struct pool_info *newpoolinfo; 2950 struct raid1_info *newmirrors; 2951 struct r1conf *conf = mddev->private; 2952 int cnt, raid_disks; 2953 unsigned long flags; 2954 int d, d2, err; 2955 2956 /* Cannot change chunk_size, layout, or level */ 2957 if (mddev->chunk_sectors != mddev->new_chunk_sectors || 2958 mddev->layout != mddev->new_layout || 2959 mddev->level != mddev->new_level) { 2960 mddev->new_chunk_sectors = mddev->chunk_sectors; 2961 mddev->new_layout = mddev->layout; 2962 mddev->new_level = mddev->level; 2963 return -EINVAL; 2964 } 2965 2966 err = md_allow_write(mddev); 2967 if (err) 2968 return err; 2969 2970 raid_disks = mddev->raid_disks + mddev->delta_disks; 2971 2972 if (raid_disks < conf->raid_disks) { 2973 cnt=0; 2974 for (d= 0; d < conf->raid_disks; d++) 2975 if (conf->mirrors[d].rdev) 2976 cnt++; 2977 if (cnt > raid_disks) 2978 return -EBUSY; 2979 } 2980 2981 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); 2982 if (!newpoolinfo) 2983 return -ENOMEM; 2984 newpoolinfo->mddev = mddev; 2985 newpoolinfo->raid_disks = raid_disks * 2; 2986 2987 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2988 r1bio_pool_free, newpoolinfo); 2989 if (!newpool) { 2990 kfree(newpoolinfo); 2991 return -ENOMEM; 2992 } 2993 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2, 2994 GFP_KERNEL); 2995 if (!newmirrors) { 2996 kfree(newpoolinfo); 2997 mempool_destroy(newpool); 2998 return -ENOMEM; 2999 } 3000 3001 raise_barrier(conf); 3002 3003 /* ok, everything is stopped */ 3004 oldpool = conf->r1bio_pool; 3005 conf->r1bio_pool = newpool; 3006 3007 for (d = d2 = 0; d < conf->raid_disks; d++) { 3008 struct md_rdev *rdev = conf->mirrors[d].rdev; 3009 if (rdev && rdev->raid_disk != d2) { 3010 sysfs_unlink_rdev(mddev, rdev); 3011 rdev->raid_disk = d2; 3012 sysfs_unlink_rdev(mddev, rdev); 3013 if (sysfs_link_rdev(mddev, rdev)) 3014 printk(KERN_WARNING 3015 "md/raid1:%s: cannot register rd%d\n", 3016 mdname(mddev), rdev->raid_disk); 3017 } 3018 if (rdev) 3019 newmirrors[d2++].rdev = rdev; 3020 } 3021 kfree(conf->mirrors); 3022 conf->mirrors = newmirrors; 3023 kfree(conf->poolinfo); 3024 conf->poolinfo = newpoolinfo; 3025 3026 spin_lock_irqsave(&conf->device_lock, flags); 3027 mddev->degraded += (raid_disks - conf->raid_disks); 3028 spin_unlock_irqrestore(&conf->device_lock, flags); 3029 conf->raid_disks = mddev->raid_disks = raid_disks; 3030 mddev->delta_disks = 0; 3031 3032 lower_barrier(conf); 3033 3034 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 3035 md_wakeup_thread(mddev->thread); 3036 3037 mempool_destroy(oldpool); 3038 return 0; 3039 } 3040 3041 static void raid1_quiesce(struct mddev *mddev, int state) 3042 { 3043 struct r1conf *conf = mddev->private; 3044 3045 switch(state) { 3046 case 2: /* wake for suspend */ 3047 wake_up(&conf->wait_barrier); 3048 break; 3049 case 1: 3050 raise_barrier(conf); 3051 break; 3052 case 0: 3053 lower_barrier(conf); 3054 break; 3055 } 3056 } 3057 3058 static void *raid1_takeover(struct mddev *mddev) 3059 { 3060 /* raid1 can take over: 3061 * raid5 with 2 devices, any layout or chunk size 3062 */ 3063 if (mddev->level == 5 && mddev->raid_disks == 2) { 3064 struct r1conf *conf; 3065 mddev->new_level = 1; 3066 mddev->new_layout = 0; 3067 mddev->new_chunk_sectors = 0; 3068 conf = setup_conf(mddev); 3069 if (!IS_ERR(conf)) 3070 conf->barrier = 1; 3071 return conf; 3072 } 3073 return ERR_PTR(-EINVAL); 3074 } 3075 3076 static struct md_personality raid1_personality = 3077 { 3078 .name = "raid1", 3079 .level = 1, 3080 .owner = THIS_MODULE, 3081 .make_request = make_request, 3082 .run = run, 3083 .stop = stop, 3084 .status = status, 3085 .error_handler = error, 3086 .hot_add_disk = raid1_add_disk, 3087 .hot_remove_disk= raid1_remove_disk, 3088 .spare_active = raid1_spare_active, 3089 .sync_request = sync_request, 3090 .resize = raid1_resize, 3091 .size = raid1_size, 3092 .check_reshape = raid1_reshape, 3093 .quiesce = raid1_quiesce, 3094 .takeover = raid1_takeover, 3095 }; 3096 3097 static int __init raid_init(void) 3098 { 3099 return register_md_personality(&raid1_personality); 3100 } 3101 3102 static void raid_exit(void) 3103 { 3104 unregister_md_personality(&raid1_personality); 3105 } 3106 3107 module_init(raid_init); 3108 module_exit(raid_exit); 3109 MODULE_LICENSE("GPL"); 3110 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); 3111 MODULE_ALIAS("md-personality-3"); /* RAID1 */ 3112 MODULE_ALIAS("md-raid1"); 3113 MODULE_ALIAS("md-level-1"); 3114 3115 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR); 3116