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/delay.h> 35 #include <linux/blkdev.h> 36 #include <linux/seq_file.h> 37 #include "md.h" 38 #include "raid1.h" 39 #include "bitmap.h" 40 41 #define DEBUG 0 42 #if DEBUG 43 #define PRINTK(x...) printk(x) 44 #else 45 #define PRINTK(x...) 46 #endif 47 48 /* 49 * Number of guaranteed r1bios in case of extreme VM load: 50 */ 51 #define NR_RAID1_BIOS 256 52 53 54 static void unplug_slaves(mddev_t *mddev); 55 56 static void allow_barrier(conf_t *conf); 57 static void lower_barrier(conf_t *conf); 58 59 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) 60 { 61 struct pool_info *pi = data; 62 r1bio_t *r1_bio; 63 int size = offsetof(r1bio_t, bios[pi->raid_disks]); 64 65 /* allocate a r1bio with room for raid_disks entries in the bios array */ 66 r1_bio = kzalloc(size, gfp_flags); 67 if (!r1_bio) 68 unplug_slaves(pi->mddev); 69 70 return r1_bio; 71 } 72 73 static void r1bio_pool_free(void *r1_bio, void *data) 74 { 75 kfree(r1_bio); 76 } 77 78 #define RESYNC_BLOCK_SIZE (64*1024) 79 //#define RESYNC_BLOCK_SIZE PAGE_SIZE 80 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) 81 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) 82 #define RESYNC_WINDOW (2048*1024) 83 84 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) 85 { 86 struct pool_info *pi = data; 87 struct page *page; 88 r1bio_t *r1_bio; 89 struct bio *bio; 90 int i, j; 91 92 r1_bio = r1bio_pool_alloc(gfp_flags, pi); 93 if (!r1_bio) { 94 unplug_slaves(pi->mddev); 95 return NULL; 96 } 97 98 /* 99 * Allocate bios : 1 for reading, n-1 for writing 100 */ 101 for (j = pi->raid_disks ; j-- ; ) { 102 bio = bio_alloc(gfp_flags, RESYNC_PAGES); 103 if (!bio) 104 goto out_free_bio; 105 r1_bio->bios[j] = bio; 106 } 107 /* 108 * Allocate RESYNC_PAGES data pages and attach them to 109 * the first bio. 110 * If this is a user-requested check/repair, allocate 111 * RESYNC_PAGES for each bio. 112 */ 113 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) 114 j = pi->raid_disks; 115 else 116 j = 1; 117 while(j--) { 118 bio = r1_bio->bios[j]; 119 for (i = 0; i < RESYNC_PAGES; i++) { 120 page = alloc_page(gfp_flags); 121 if (unlikely(!page)) 122 goto out_free_pages; 123 124 bio->bi_io_vec[i].bv_page = page; 125 bio->bi_vcnt = i+1; 126 } 127 } 128 /* If not user-requests, copy the page pointers to all bios */ 129 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { 130 for (i=0; i<RESYNC_PAGES ; i++) 131 for (j=1; j<pi->raid_disks; j++) 132 r1_bio->bios[j]->bi_io_vec[i].bv_page = 133 r1_bio->bios[0]->bi_io_vec[i].bv_page; 134 } 135 136 r1_bio->master_bio = NULL; 137 138 return r1_bio; 139 140 out_free_pages: 141 for (j=0 ; j < pi->raid_disks; j++) 142 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++) 143 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page); 144 j = -1; 145 out_free_bio: 146 while ( ++j < pi->raid_disks ) 147 bio_put(r1_bio->bios[j]); 148 r1bio_pool_free(r1_bio, data); 149 return NULL; 150 } 151 152 static void r1buf_pool_free(void *__r1_bio, void *data) 153 { 154 struct pool_info *pi = data; 155 int i,j; 156 r1bio_t *r1bio = __r1_bio; 157 158 for (i = 0; i < RESYNC_PAGES; i++) 159 for (j = pi->raid_disks; j-- ;) { 160 if (j == 0 || 161 r1bio->bios[j]->bi_io_vec[i].bv_page != 162 r1bio->bios[0]->bi_io_vec[i].bv_page) 163 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page); 164 } 165 for (i=0 ; i < pi->raid_disks; i++) 166 bio_put(r1bio->bios[i]); 167 168 r1bio_pool_free(r1bio, data); 169 } 170 171 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio) 172 { 173 int i; 174 175 for (i = 0; i < conf->raid_disks; i++) { 176 struct bio **bio = r1_bio->bios + i; 177 if (*bio && *bio != IO_BLOCKED) 178 bio_put(*bio); 179 *bio = NULL; 180 } 181 } 182 183 static void free_r1bio(r1bio_t *r1_bio) 184 { 185 conf_t *conf = r1_bio->mddev->private; 186 187 /* 188 * Wake up any possible resync thread that waits for the device 189 * to go idle. 190 */ 191 allow_barrier(conf); 192 193 put_all_bios(conf, r1_bio); 194 mempool_free(r1_bio, conf->r1bio_pool); 195 } 196 197 static void put_buf(r1bio_t *r1_bio) 198 { 199 conf_t *conf = r1_bio->mddev->private; 200 int i; 201 202 for (i=0; i<conf->raid_disks; 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(r1bio_t *r1_bio) 214 { 215 unsigned long flags; 216 mddev_t *mddev = r1_bio->mddev; 217 conf_t *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 raid_end_bio_io(r1bio_t *r1_bio) 234 { 235 struct bio *bio = r1_bio->master_bio; 236 237 /* if nobody has done the final endio yet, do it now */ 238 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 239 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n", 240 (bio_data_dir(bio) == WRITE) ? "write" : "read", 241 (unsigned long long) bio->bi_sector, 242 (unsigned long long) bio->bi_sector + 243 (bio->bi_size >> 9) - 1); 244 245 bio_endio(bio, 246 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); 247 } 248 free_r1bio(r1_bio); 249 } 250 251 /* 252 * Update disk head position estimator based on IRQ completion info. 253 */ 254 static inline void update_head_pos(int disk, r1bio_t *r1_bio) 255 { 256 conf_t *conf = r1_bio->mddev->private; 257 258 conf->mirrors[disk].head_position = 259 r1_bio->sector + (r1_bio->sectors); 260 } 261 262 static void raid1_end_read_request(struct bio *bio, int error) 263 { 264 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 265 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 266 int mirror; 267 conf_t *conf = r1_bio->mddev->private; 268 269 mirror = r1_bio->read_disk; 270 /* 271 * this branch is our 'one mirror IO has finished' event handler: 272 */ 273 update_head_pos(mirror, r1_bio); 274 275 if (uptodate) 276 set_bit(R1BIO_Uptodate, &r1_bio->state); 277 else { 278 /* If all other devices have failed, we want to return 279 * the error upwards rather than fail the last device. 280 * Here we redefine "uptodate" to mean "Don't want to retry" 281 */ 282 unsigned long flags; 283 spin_lock_irqsave(&conf->device_lock, flags); 284 if (r1_bio->mddev->degraded == conf->raid_disks || 285 (r1_bio->mddev->degraded == conf->raid_disks-1 && 286 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))) 287 uptodate = 1; 288 spin_unlock_irqrestore(&conf->device_lock, flags); 289 } 290 291 if (uptodate) 292 raid_end_bio_io(r1_bio); 293 else { 294 /* 295 * oops, read error: 296 */ 297 char b[BDEVNAME_SIZE]; 298 if (printk_ratelimit()) 299 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n", 300 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector); 301 reschedule_retry(r1_bio); 302 } 303 304 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); 305 } 306 307 static void raid1_end_write_request(struct bio *bio, int error) 308 { 309 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 310 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 311 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state); 312 conf_t *conf = r1_bio->mddev->private; 313 struct bio *to_put = NULL; 314 315 316 for (mirror = 0; mirror < conf->raid_disks; mirror++) 317 if (r1_bio->bios[mirror] == bio) 318 break; 319 320 if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) { 321 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags); 322 set_bit(R1BIO_BarrierRetry, &r1_bio->state); 323 r1_bio->mddev->barriers_work = 0; 324 /* Don't rdev_dec_pending in this branch - keep it for the retry */ 325 } else { 326 /* 327 * this branch is our 'one mirror IO has finished' event handler: 328 */ 329 r1_bio->bios[mirror] = NULL; 330 to_put = bio; 331 if (!uptodate) { 332 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); 333 /* an I/O failed, we can't clear the bitmap */ 334 set_bit(R1BIO_Degraded, &r1_bio->state); 335 } else 336 /* 337 * Set R1BIO_Uptodate in our master bio, so that 338 * we will return a good error code for to the higher 339 * levels even if IO on some other mirrored buffer fails. 340 * 341 * The 'master' represents the composite IO operation to 342 * user-side. So if something waits for IO, then it will 343 * wait for the 'master' bio. 344 */ 345 set_bit(R1BIO_Uptodate, &r1_bio->state); 346 347 update_head_pos(mirror, r1_bio); 348 349 if (behind) { 350 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) 351 atomic_dec(&r1_bio->behind_remaining); 352 353 /* In behind mode, we ACK the master bio once the I/O has safely 354 * reached all non-writemostly disks. Setting the Returned bit 355 * ensures that this gets done only once -- we don't ever want to 356 * return -EIO here, instead we'll wait */ 357 358 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && 359 test_bit(R1BIO_Uptodate, &r1_bio->state)) { 360 /* Maybe we can return now */ 361 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { 362 struct bio *mbio = r1_bio->master_bio; 363 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", 364 (unsigned long long) mbio->bi_sector, 365 (unsigned long long) mbio->bi_sector + 366 (mbio->bi_size >> 9) - 1); 367 bio_endio(mbio, 0); 368 } 369 } 370 } 371 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); 372 } 373 /* 374 * 375 * Let's see if all mirrored write operations have finished 376 * already. 377 */ 378 if (atomic_dec_and_test(&r1_bio->remaining)) { 379 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) 380 reschedule_retry(r1_bio); 381 else { 382 /* it really is the end of this request */ 383 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { 384 /* free extra copy of the data pages */ 385 int i = bio->bi_vcnt; 386 while (i--) 387 safe_put_page(bio->bi_io_vec[i].bv_page); 388 } 389 /* clear the bitmap if all writes complete successfully */ 390 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, 391 r1_bio->sectors, 392 !test_bit(R1BIO_Degraded, &r1_bio->state), 393 behind); 394 md_write_end(r1_bio->mddev); 395 raid_end_bio_io(r1_bio); 396 } 397 } 398 399 if (to_put) 400 bio_put(to_put); 401 } 402 403 404 /* 405 * This routine returns the disk from which the requested read should 406 * be done. There is a per-array 'next expected sequential IO' sector 407 * number - if this matches on the next IO then we use the last disk. 408 * There is also a per-disk 'last know head position' sector that is 409 * maintained from IRQ contexts, both the normal and the resync IO 410 * completion handlers update this position correctly. If there is no 411 * perfect sequential match then we pick the disk whose head is closest. 412 * 413 * If there are 2 mirrors in the same 2 devices, performance degrades 414 * because position is mirror, not device based. 415 * 416 * The rdev for the device selected will have nr_pending incremented. 417 */ 418 static int read_balance(conf_t *conf, r1bio_t *r1_bio) 419 { 420 const unsigned long this_sector = r1_bio->sector; 421 int new_disk = conf->last_used, disk = new_disk; 422 int wonly_disk = -1; 423 const int sectors = r1_bio->sectors; 424 sector_t new_distance, current_distance; 425 mdk_rdev_t *rdev; 426 427 rcu_read_lock(); 428 /* 429 * Check if we can balance. We can balance on the whole 430 * device if no resync is going on, or below the resync window. 431 * We take the first readable disk when above the resync window. 432 */ 433 retry: 434 if (conf->mddev->recovery_cp < MaxSector && 435 (this_sector + sectors >= conf->next_resync)) { 436 /* Choose the first operation device, for consistancy */ 437 new_disk = 0; 438 439 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev); 440 r1_bio->bios[new_disk] == IO_BLOCKED || 441 !rdev || !test_bit(In_sync, &rdev->flags) 442 || test_bit(WriteMostly, &rdev->flags); 443 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) { 444 445 if (rdev && test_bit(In_sync, &rdev->flags) && 446 r1_bio->bios[new_disk] != IO_BLOCKED) 447 wonly_disk = new_disk; 448 449 if (new_disk == conf->raid_disks - 1) { 450 new_disk = wonly_disk; 451 break; 452 } 453 } 454 goto rb_out; 455 } 456 457 458 /* make sure the disk is operational */ 459 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev); 460 r1_bio->bios[new_disk] == IO_BLOCKED || 461 !rdev || !test_bit(In_sync, &rdev->flags) || 462 test_bit(WriteMostly, &rdev->flags); 463 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) { 464 465 if (rdev && test_bit(In_sync, &rdev->flags) && 466 r1_bio->bios[new_disk] != IO_BLOCKED) 467 wonly_disk = new_disk; 468 469 if (new_disk <= 0) 470 new_disk = conf->raid_disks; 471 new_disk--; 472 if (new_disk == disk) { 473 new_disk = wonly_disk; 474 break; 475 } 476 } 477 478 if (new_disk < 0) 479 goto rb_out; 480 481 disk = new_disk; 482 /* now disk == new_disk == starting point for search */ 483 484 /* 485 * Don't change to another disk for sequential reads: 486 */ 487 if (conf->next_seq_sect == this_sector) 488 goto rb_out; 489 if (this_sector == conf->mirrors[new_disk].head_position) 490 goto rb_out; 491 492 current_distance = abs(this_sector - conf->mirrors[disk].head_position); 493 494 /* Find the disk whose head is closest */ 495 496 do { 497 if (disk <= 0) 498 disk = conf->raid_disks; 499 disk--; 500 501 rdev = rcu_dereference(conf->mirrors[disk].rdev); 502 503 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED || 504 !test_bit(In_sync, &rdev->flags) || 505 test_bit(WriteMostly, &rdev->flags)) 506 continue; 507 508 if (!atomic_read(&rdev->nr_pending)) { 509 new_disk = disk; 510 break; 511 } 512 new_distance = abs(this_sector - conf->mirrors[disk].head_position); 513 if (new_distance < current_distance) { 514 current_distance = new_distance; 515 new_disk = disk; 516 } 517 } while (disk != conf->last_used); 518 519 rb_out: 520 521 522 if (new_disk >= 0) { 523 rdev = rcu_dereference(conf->mirrors[new_disk].rdev); 524 if (!rdev) 525 goto retry; 526 atomic_inc(&rdev->nr_pending); 527 if (!test_bit(In_sync, &rdev->flags)) { 528 /* cannot risk returning a device that failed 529 * before we inc'ed nr_pending 530 */ 531 rdev_dec_pending(rdev, conf->mddev); 532 goto retry; 533 } 534 conf->next_seq_sect = this_sector + sectors; 535 conf->last_used = new_disk; 536 } 537 rcu_read_unlock(); 538 539 return new_disk; 540 } 541 542 static void unplug_slaves(mddev_t *mddev) 543 { 544 conf_t *conf = mddev->private; 545 int i; 546 547 rcu_read_lock(); 548 for (i=0; i<mddev->raid_disks; i++) { 549 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 550 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { 551 struct request_queue *r_queue = bdev_get_queue(rdev->bdev); 552 553 atomic_inc(&rdev->nr_pending); 554 rcu_read_unlock(); 555 556 blk_unplug(r_queue); 557 558 rdev_dec_pending(rdev, mddev); 559 rcu_read_lock(); 560 } 561 } 562 rcu_read_unlock(); 563 } 564 565 static void raid1_unplug(struct request_queue *q) 566 { 567 mddev_t *mddev = q->queuedata; 568 569 unplug_slaves(mddev); 570 md_wakeup_thread(mddev->thread); 571 } 572 573 static int raid1_congested(void *data, int bits) 574 { 575 mddev_t *mddev = data; 576 conf_t *conf = mddev->private; 577 int i, ret = 0; 578 579 rcu_read_lock(); 580 for (i = 0; i < mddev->raid_disks; i++) { 581 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 582 if (rdev && !test_bit(Faulty, &rdev->flags)) { 583 struct request_queue *q = bdev_get_queue(rdev->bdev); 584 585 /* Note the '|| 1' - when read_balance prefers 586 * non-congested targets, it can be removed 587 */ 588 if ((bits & (1<<BDI_async_congested)) || 1) 589 ret |= bdi_congested(&q->backing_dev_info, bits); 590 else 591 ret &= bdi_congested(&q->backing_dev_info, bits); 592 } 593 } 594 rcu_read_unlock(); 595 return ret; 596 } 597 598 599 static int flush_pending_writes(conf_t *conf) 600 { 601 /* Any writes that have been queued but are awaiting 602 * bitmap updates get flushed here. 603 * We return 1 if any requests were actually submitted. 604 */ 605 int rv = 0; 606 607 spin_lock_irq(&conf->device_lock); 608 609 if (conf->pending_bio_list.head) { 610 struct bio *bio; 611 bio = bio_list_get(&conf->pending_bio_list); 612 blk_remove_plug(conf->mddev->queue); 613 spin_unlock_irq(&conf->device_lock); 614 /* flush any pending bitmap writes to 615 * disk before proceeding w/ I/O */ 616 bitmap_unplug(conf->mddev->bitmap); 617 618 while (bio) { /* submit pending writes */ 619 struct bio *next = bio->bi_next; 620 bio->bi_next = NULL; 621 generic_make_request(bio); 622 bio = next; 623 } 624 rv = 1; 625 } else 626 spin_unlock_irq(&conf->device_lock); 627 return rv; 628 } 629 630 /* Barriers.... 631 * Sometimes we need to suspend IO while we do something else, 632 * either some resync/recovery, or reconfigure the array. 633 * To do this we raise a 'barrier'. 634 * The 'barrier' is a counter that can be raised multiple times 635 * to count how many activities are happening which preclude 636 * normal IO. 637 * We can only raise the barrier if there is no pending IO. 638 * i.e. if nr_pending == 0. 639 * We choose only to raise the barrier if no-one is waiting for the 640 * barrier to go down. This means that as soon as an IO request 641 * is ready, no other operations which require a barrier will start 642 * until the IO request has had a chance. 643 * 644 * So: regular IO calls 'wait_barrier'. When that returns there 645 * is no backgroup IO happening, It must arrange to call 646 * allow_barrier when it has finished its IO. 647 * backgroup IO calls must call raise_barrier. Once that returns 648 * there is no normal IO happeing. It must arrange to call 649 * lower_barrier when the particular background IO completes. 650 */ 651 #define RESYNC_DEPTH 32 652 653 static void raise_barrier(conf_t *conf) 654 { 655 spin_lock_irq(&conf->resync_lock); 656 657 /* Wait until no block IO is waiting */ 658 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, 659 conf->resync_lock, 660 raid1_unplug(conf->mddev->queue)); 661 662 /* block any new IO from starting */ 663 conf->barrier++; 664 665 /* No wait for all pending IO to complete */ 666 wait_event_lock_irq(conf->wait_barrier, 667 !conf->nr_pending && conf->barrier < RESYNC_DEPTH, 668 conf->resync_lock, 669 raid1_unplug(conf->mddev->queue)); 670 671 spin_unlock_irq(&conf->resync_lock); 672 } 673 674 static void lower_barrier(conf_t *conf) 675 { 676 unsigned long flags; 677 spin_lock_irqsave(&conf->resync_lock, flags); 678 conf->barrier--; 679 spin_unlock_irqrestore(&conf->resync_lock, flags); 680 wake_up(&conf->wait_barrier); 681 } 682 683 static void wait_barrier(conf_t *conf) 684 { 685 spin_lock_irq(&conf->resync_lock); 686 if (conf->barrier) { 687 conf->nr_waiting++; 688 wait_event_lock_irq(conf->wait_barrier, !conf->barrier, 689 conf->resync_lock, 690 raid1_unplug(conf->mddev->queue)); 691 conf->nr_waiting--; 692 } 693 conf->nr_pending++; 694 spin_unlock_irq(&conf->resync_lock); 695 } 696 697 static void allow_barrier(conf_t *conf) 698 { 699 unsigned long flags; 700 spin_lock_irqsave(&conf->resync_lock, flags); 701 conf->nr_pending--; 702 spin_unlock_irqrestore(&conf->resync_lock, flags); 703 wake_up(&conf->wait_barrier); 704 } 705 706 static void freeze_array(conf_t *conf) 707 { 708 /* stop syncio and normal IO and wait for everything to 709 * go quite. 710 * We increment barrier and nr_waiting, and then 711 * wait until nr_pending match nr_queued+1 712 * This is called in the context of one normal IO request 713 * that has failed. Thus any sync request that might be pending 714 * will be blocked by nr_pending, and we need to wait for 715 * pending IO requests to complete or be queued for re-try. 716 * Thus the number queued (nr_queued) plus this request (1) 717 * must match the number of pending IOs (nr_pending) before 718 * we continue. 719 */ 720 spin_lock_irq(&conf->resync_lock); 721 conf->barrier++; 722 conf->nr_waiting++; 723 wait_event_lock_irq(conf->wait_barrier, 724 conf->nr_pending == conf->nr_queued+1, 725 conf->resync_lock, 726 ({ flush_pending_writes(conf); 727 raid1_unplug(conf->mddev->queue); })); 728 spin_unlock_irq(&conf->resync_lock); 729 } 730 static void unfreeze_array(conf_t *conf) 731 { 732 /* reverse the effect of the freeze */ 733 spin_lock_irq(&conf->resync_lock); 734 conf->barrier--; 735 conf->nr_waiting--; 736 wake_up(&conf->wait_barrier); 737 spin_unlock_irq(&conf->resync_lock); 738 } 739 740 741 /* duplicate the data pages for behind I/O */ 742 static struct page **alloc_behind_pages(struct bio *bio) 743 { 744 int i; 745 struct bio_vec *bvec; 746 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *), 747 GFP_NOIO); 748 if (unlikely(!pages)) 749 goto do_sync_io; 750 751 bio_for_each_segment(bvec, bio, i) { 752 pages[i] = alloc_page(GFP_NOIO); 753 if (unlikely(!pages[i])) 754 goto do_sync_io; 755 memcpy(kmap(pages[i]) + bvec->bv_offset, 756 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); 757 kunmap(pages[i]); 758 kunmap(bvec->bv_page); 759 } 760 761 return pages; 762 763 do_sync_io: 764 if (pages) 765 for (i = 0; i < bio->bi_vcnt && pages[i]; i++) 766 put_page(pages[i]); 767 kfree(pages); 768 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); 769 return NULL; 770 } 771 772 static int make_request(struct request_queue *q, struct bio * bio) 773 { 774 mddev_t *mddev = q->queuedata; 775 conf_t *conf = mddev->private; 776 mirror_info_t *mirror; 777 r1bio_t *r1_bio; 778 struct bio *read_bio; 779 int i, targets = 0, disks; 780 struct bitmap *bitmap; 781 unsigned long flags; 782 struct bio_list bl; 783 struct page **behind_pages = NULL; 784 const int rw = bio_data_dir(bio); 785 const bool do_sync = bio_rw_flagged(bio, BIO_RW_SYNCIO); 786 int cpu; 787 bool do_barriers; 788 mdk_rdev_t *blocked_rdev; 789 790 /* 791 * Register the new request and wait if the reconstruction 792 * thread has put up a bar for new requests. 793 * Continue immediately if no resync is active currently. 794 * We test barriers_work *after* md_write_start as md_write_start 795 * may cause the first superblock write, and that will check out 796 * if barriers work. 797 */ 798 799 md_write_start(mddev, bio); /* wait on superblock update early */ 800 801 if (unlikely(!mddev->barriers_work && 802 bio_rw_flagged(bio, BIO_RW_BARRIER))) { 803 if (rw == WRITE) 804 md_write_end(mddev); 805 bio_endio(bio, -EOPNOTSUPP); 806 return 0; 807 } 808 809 wait_barrier(conf); 810 811 bitmap = mddev->bitmap; 812 813 cpu = part_stat_lock(); 814 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); 815 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], 816 bio_sectors(bio)); 817 part_stat_unlock(); 818 819 /* 820 * make_request() can abort the operation when READA is being 821 * used and no empty request is available. 822 * 823 */ 824 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 825 826 r1_bio->master_bio = bio; 827 r1_bio->sectors = bio->bi_size >> 9; 828 r1_bio->state = 0; 829 r1_bio->mddev = mddev; 830 r1_bio->sector = bio->bi_sector; 831 832 if (rw == READ) { 833 /* 834 * read balancing logic: 835 */ 836 int rdisk = read_balance(conf, r1_bio); 837 838 if (rdisk < 0) { 839 /* couldn't find anywhere to read from */ 840 raid_end_bio_io(r1_bio); 841 return 0; 842 } 843 mirror = conf->mirrors + rdisk; 844 845 r1_bio->read_disk = rdisk; 846 847 read_bio = bio_clone(bio, GFP_NOIO); 848 849 r1_bio->bios[rdisk] = read_bio; 850 851 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; 852 read_bio->bi_bdev = mirror->rdev->bdev; 853 read_bio->bi_end_io = raid1_end_read_request; 854 read_bio->bi_rw = READ | do_sync; 855 read_bio->bi_private = r1_bio; 856 857 generic_make_request(read_bio); 858 return 0; 859 } 860 861 /* 862 * WRITE: 863 */ 864 /* first select target devices under spinlock and 865 * inc refcount on their rdev. Record them by setting 866 * bios[x] to bio 867 */ 868 disks = conf->raid_disks; 869 #if 0 870 { static int first=1; 871 if (first) printk("First Write sector %llu disks %d\n", 872 (unsigned long long)r1_bio->sector, disks); 873 first = 0; 874 } 875 #endif 876 retry_write: 877 blocked_rdev = NULL; 878 rcu_read_lock(); 879 for (i = 0; i < disks; i++) { 880 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 881 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { 882 atomic_inc(&rdev->nr_pending); 883 blocked_rdev = rdev; 884 break; 885 } 886 if (rdev && !test_bit(Faulty, &rdev->flags)) { 887 atomic_inc(&rdev->nr_pending); 888 if (test_bit(Faulty, &rdev->flags)) { 889 rdev_dec_pending(rdev, mddev); 890 r1_bio->bios[i] = NULL; 891 } else 892 r1_bio->bios[i] = bio; 893 targets++; 894 } else 895 r1_bio->bios[i] = NULL; 896 } 897 rcu_read_unlock(); 898 899 if (unlikely(blocked_rdev)) { 900 /* Wait for this device to become unblocked */ 901 int j; 902 903 for (j = 0; j < i; j++) 904 if (r1_bio->bios[j]) 905 rdev_dec_pending(conf->mirrors[j].rdev, mddev); 906 907 allow_barrier(conf); 908 md_wait_for_blocked_rdev(blocked_rdev, mddev); 909 wait_barrier(conf); 910 goto retry_write; 911 } 912 913 BUG_ON(targets == 0); /* we never fail the last device */ 914 915 if (targets < conf->raid_disks) { 916 /* array is degraded, we will not clear the bitmap 917 * on I/O completion (see raid1_end_write_request) */ 918 set_bit(R1BIO_Degraded, &r1_bio->state); 919 } 920 921 /* do behind I/O ? */ 922 if (bitmap && 923 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind && 924 (behind_pages = alloc_behind_pages(bio)) != NULL) 925 set_bit(R1BIO_BehindIO, &r1_bio->state); 926 927 atomic_set(&r1_bio->remaining, 0); 928 atomic_set(&r1_bio->behind_remaining, 0); 929 930 do_barriers = bio_rw_flagged(bio, BIO_RW_BARRIER); 931 if (do_barriers) 932 set_bit(R1BIO_Barrier, &r1_bio->state); 933 934 bio_list_init(&bl); 935 for (i = 0; i < disks; i++) { 936 struct bio *mbio; 937 if (!r1_bio->bios[i]) 938 continue; 939 940 mbio = bio_clone(bio, GFP_NOIO); 941 r1_bio->bios[i] = mbio; 942 943 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; 944 mbio->bi_bdev = conf->mirrors[i].rdev->bdev; 945 mbio->bi_end_io = raid1_end_write_request; 946 mbio->bi_rw = WRITE | do_barriers | do_sync; 947 mbio->bi_private = r1_bio; 948 949 if (behind_pages) { 950 struct bio_vec *bvec; 951 int j; 952 953 /* Yes, I really want the '__' version so that 954 * we clear any unused pointer in the io_vec, rather 955 * than leave them unchanged. This is important 956 * because when we come to free the pages, we won't 957 * know the originial bi_idx, so we just free 958 * them all 959 */ 960 __bio_for_each_segment(bvec, mbio, j, 0) 961 bvec->bv_page = behind_pages[j]; 962 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) 963 atomic_inc(&r1_bio->behind_remaining); 964 } 965 966 atomic_inc(&r1_bio->remaining); 967 968 bio_list_add(&bl, mbio); 969 } 970 kfree(behind_pages); /* the behind pages are attached to the bios now */ 971 972 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors, 973 test_bit(R1BIO_BehindIO, &r1_bio->state)); 974 spin_lock_irqsave(&conf->device_lock, flags); 975 bio_list_merge(&conf->pending_bio_list, &bl); 976 bio_list_init(&bl); 977 978 blk_plug_device(mddev->queue); 979 spin_unlock_irqrestore(&conf->device_lock, flags); 980 981 /* In case raid1d snuck into freeze_array */ 982 wake_up(&conf->wait_barrier); 983 984 if (do_sync) 985 md_wakeup_thread(mddev->thread); 986 #if 0 987 while ((bio = bio_list_pop(&bl)) != NULL) 988 generic_make_request(bio); 989 #endif 990 991 return 0; 992 } 993 994 static void status(struct seq_file *seq, mddev_t *mddev) 995 { 996 conf_t *conf = mddev->private; 997 int i; 998 999 seq_printf(seq, " [%d/%d] [", conf->raid_disks, 1000 conf->raid_disks - mddev->degraded); 1001 rcu_read_lock(); 1002 for (i = 0; i < conf->raid_disks; i++) { 1003 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 1004 seq_printf(seq, "%s", 1005 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); 1006 } 1007 rcu_read_unlock(); 1008 seq_printf(seq, "]"); 1009 } 1010 1011 1012 static void error(mddev_t *mddev, mdk_rdev_t *rdev) 1013 { 1014 char b[BDEVNAME_SIZE]; 1015 conf_t *conf = mddev->private; 1016 1017 /* 1018 * If it is not operational, then we have already marked it as dead 1019 * else if it is the last working disks, ignore the error, let the 1020 * next level up know. 1021 * else mark the drive as failed 1022 */ 1023 if (test_bit(In_sync, &rdev->flags) 1024 && (conf->raid_disks - mddev->degraded) == 1) { 1025 /* 1026 * Don't fail the drive, act as though we were just a 1027 * normal single drive. 1028 * However don't try a recovery from this drive as 1029 * it is very likely to fail. 1030 */ 1031 mddev->recovery_disabled = 1; 1032 return; 1033 } 1034 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1035 unsigned long flags; 1036 spin_lock_irqsave(&conf->device_lock, flags); 1037 mddev->degraded++; 1038 set_bit(Faulty, &rdev->flags); 1039 spin_unlock_irqrestore(&conf->device_lock, flags); 1040 /* 1041 * if recovery is running, make sure it aborts. 1042 */ 1043 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1044 } else 1045 set_bit(Faulty, &rdev->flags); 1046 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1047 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n" 1048 "raid1: Operation continuing on %d devices.\n", 1049 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); 1050 } 1051 1052 static void print_conf(conf_t *conf) 1053 { 1054 int i; 1055 1056 printk("RAID1 conf printout:\n"); 1057 if (!conf) { 1058 printk("(!conf)\n"); 1059 return; 1060 } 1061 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, 1062 conf->raid_disks); 1063 1064 rcu_read_lock(); 1065 for (i = 0; i < conf->raid_disks; i++) { 1066 char b[BDEVNAME_SIZE]; 1067 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 1068 if (rdev) 1069 printk(" disk %d, wo:%d, o:%d, dev:%s\n", 1070 i, !test_bit(In_sync, &rdev->flags), 1071 !test_bit(Faulty, &rdev->flags), 1072 bdevname(rdev->bdev,b)); 1073 } 1074 rcu_read_unlock(); 1075 } 1076 1077 static void close_sync(conf_t *conf) 1078 { 1079 wait_barrier(conf); 1080 allow_barrier(conf); 1081 1082 mempool_destroy(conf->r1buf_pool); 1083 conf->r1buf_pool = NULL; 1084 } 1085 1086 static int raid1_spare_active(mddev_t *mddev) 1087 { 1088 int i; 1089 conf_t *conf = mddev->private; 1090 1091 /* 1092 * Find all failed disks within the RAID1 configuration 1093 * and mark them readable. 1094 * Called under mddev lock, so rcu protection not needed. 1095 */ 1096 for (i = 0; i < conf->raid_disks; i++) { 1097 mdk_rdev_t *rdev = conf->mirrors[i].rdev; 1098 if (rdev 1099 && !test_bit(Faulty, &rdev->flags) 1100 && !test_and_set_bit(In_sync, &rdev->flags)) { 1101 unsigned long flags; 1102 spin_lock_irqsave(&conf->device_lock, flags); 1103 mddev->degraded--; 1104 spin_unlock_irqrestore(&conf->device_lock, flags); 1105 } 1106 } 1107 1108 print_conf(conf); 1109 return 0; 1110 } 1111 1112 1113 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) 1114 { 1115 conf_t *conf = mddev->private; 1116 int err = -EEXIST; 1117 int mirror = 0; 1118 mirror_info_t *p; 1119 int first = 0; 1120 int last = mddev->raid_disks - 1; 1121 1122 if (rdev->raid_disk >= 0) 1123 first = last = rdev->raid_disk; 1124 1125 for (mirror = first; mirror <= last; mirror++) 1126 if ( !(p=conf->mirrors+mirror)->rdev) { 1127 1128 disk_stack_limits(mddev->gendisk, rdev->bdev, 1129 rdev->data_offset << 9); 1130 /* as we don't honour merge_bvec_fn, we must never risk 1131 * violating it, so limit ->max_sector to one PAGE, as 1132 * a one page request is never in violation. 1133 */ 1134 if (rdev->bdev->bd_disk->queue->merge_bvec_fn && 1135 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) 1136 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); 1137 1138 p->head_position = 0; 1139 rdev->raid_disk = mirror; 1140 err = 0; 1141 /* As all devices are equivalent, we don't need a full recovery 1142 * if this was recently any drive of the array 1143 */ 1144 if (rdev->saved_raid_disk < 0) 1145 conf->fullsync = 1; 1146 rcu_assign_pointer(p->rdev, rdev); 1147 break; 1148 } 1149 md_integrity_add_rdev(rdev, mddev); 1150 print_conf(conf); 1151 return err; 1152 } 1153 1154 static int raid1_remove_disk(mddev_t *mddev, int number) 1155 { 1156 conf_t *conf = mddev->private; 1157 int err = 0; 1158 mdk_rdev_t *rdev; 1159 mirror_info_t *p = conf->mirrors+ number; 1160 1161 print_conf(conf); 1162 rdev = p->rdev; 1163 if (rdev) { 1164 if (test_bit(In_sync, &rdev->flags) || 1165 atomic_read(&rdev->nr_pending)) { 1166 err = -EBUSY; 1167 goto abort; 1168 } 1169 /* Only remove non-faulty devices is recovery 1170 * is not possible. 1171 */ 1172 if (!test_bit(Faulty, &rdev->flags) && 1173 mddev->degraded < conf->raid_disks) { 1174 err = -EBUSY; 1175 goto abort; 1176 } 1177 p->rdev = NULL; 1178 synchronize_rcu(); 1179 if (atomic_read(&rdev->nr_pending)) { 1180 /* lost the race, try later */ 1181 err = -EBUSY; 1182 p->rdev = rdev; 1183 goto abort; 1184 } 1185 md_integrity_register(mddev); 1186 } 1187 abort: 1188 1189 print_conf(conf); 1190 return err; 1191 } 1192 1193 1194 static void end_sync_read(struct bio *bio, int error) 1195 { 1196 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 1197 int i; 1198 1199 for (i=r1_bio->mddev->raid_disks; i--; ) 1200 if (r1_bio->bios[i] == bio) 1201 break; 1202 BUG_ON(i < 0); 1203 update_head_pos(i, r1_bio); 1204 /* 1205 * we have read a block, now it needs to be re-written, 1206 * or re-read if the read failed. 1207 * We don't do much here, just schedule handling by raid1d 1208 */ 1209 if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 1210 set_bit(R1BIO_Uptodate, &r1_bio->state); 1211 1212 if (atomic_dec_and_test(&r1_bio->remaining)) 1213 reschedule_retry(r1_bio); 1214 } 1215 1216 static void end_sync_write(struct bio *bio, int error) 1217 { 1218 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1219 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 1220 mddev_t *mddev = r1_bio->mddev; 1221 conf_t *conf = mddev->private; 1222 int i; 1223 int mirror=0; 1224 1225 for (i = 0; i < conf->raid_disks; i++) 1226 if (r1_bio->bios[i] == bio) { 1227 mirror = i; 1228 break; 1229 } 1230 if (!uptodate) { 1231 int sync_blocks = 0; 1232 sector_t s = r1_bio->sector; 1233 long sectors_to_go = r1_bio->sectors; 1234 /* make sure these bits doesn't get cleared. */ 1235 do { 1236 bitmap_end_sync(mddev->bitmap, s, 1237 &sync_blocks, 1); 1238 s += sync_blocks; 1239 sectors_to_go -= sync_blocks; 1240 } while (sectors_to_go > 0); 1241 md_error(mddev, conf->mirrors[mirror].rdev); 1242 } 1243 1244 update_head_pos(mirror, r1_bio); 1245 1246 if (atomic_dec_and_test(&r1_bio->remaining)) { 1247 sector_t s = r1_bio->sectors; 1248 put_buf(r1_bio); 1249 md_done_sync(mddev, s, uptodate); 1250 } 1251 } 1252 1253 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) 1254 { 1255 conf_t *conf = mddev->private; 1256 int i; 1257 int disks = conf->raid_disks; 1258 struct bio *bio, *wbio; 1259 1260 bio = r1_bio->bios[r1_bio->read_disk]; 1261 1262 1263 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1264 /* We have read all readable devices. If we haven't 1265 * got the block, then there is no hope left. 1266 * If we have, then we want to do a comparison 1267 * and skip the write if everything is the same. 1268 * If any blocks failed to read, then we need to 1269 * attempt an over-write 1270 */ 1271 int primary; 1272 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { 1273 for (i=0; i<mddev->raid_disks; i++) 1274 if (r1_bio->bios[i]->bi_end_io == end_sync_read) 1275 md_error(mddev, conf->mirrors[i].rdev); 1276 1277 md_done_sync(mddev, r1_bio->sectors, 1); 1278 put_buf(r1_bio); 1279 return; 1280 } 1281 for (primary=0; primary<mddev->raid_disks; primary++) 1282 if (r1_bio->bios[primary]->bi_end_io == end_sync_read && 1283 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { 1284 r1_bio->bios[primary]->bi_end_io = NULL; 1285 rdev_dec_pending(conf->mirrors[primary].rdev, mddev); 1286 break; 1287 } 1288 r1_bio->read_disk = primary; 1289 for (i=0; i<mddev->raid_disks; i++) 1290 if (r1_bio->bios[i]->bi_end_io == end_sync_read) { 1291 int j; 1292 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9); 1293 struct bio *pbio = r1_bio->bios[primary]; 1294 struct bio *sbio = r1_bio->bios[i]; 1295 1296 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { 1297 for (j = vcnt; j-- ; ) { 1298 struct page *p, *s; 1299 p = pbio->bi_io_vec[j].bv_page; 1300 s = sbio->bi_io_vec[j].bv_page; 1301 if (memcmp(page_address(p), 1302 page_address(s), 1303 PAGE_SIZE)) 1304 break; 1305 } 1306 } else 1307 j = 0; 1308 if (j >= 0) 1309 mddev->resync_mismatches += r1_bio->sectors; 1310 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) 1311 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { 1312 sbio->bi_end_io = NULL; 1313 rdev_dec_pending(conf->mirrors[i].rdev, mddev); 1314 } else { 1315 /* fixup the bio for reuse */ 1316 int size; 1317 sbio->bi_vcnt = vcnt; 1318 sbio->bi_size = r1_bio->sectors << 9; 1319 sbio->bi_idx = 0; 1320 sbio->bi_phys_segments = 0; 1321 sbio->bi_flags &= ~(BIO_POOL_MASK - 1); 1322 sbio->bi_flags |= 1 << BIO_UPTODATE; 1323 sbio->bi_next = NULL; 1324 sbio->bi_sector = r1_bio->sector + 1325 conf->mirrors[i].rdev->data_offset; 1326 sbio->bi_bdev = conf->mirrors[i].rdev->bdev; 1327 size = sbio->bi_size; 1328 for (j = 0; j < vcnt ; j++) { 1329 struct bio_vec *bi; 1330 bi = &sbio->bi_io_vec[j]; 1331 bi->bv_offset = 0; 1332 if (size > PAGE_SIZE) 1333 bi->bv_len = PAGE_SIZE; 1334 else 1335 bi->bv_len = size; 1336 size -= PAGE_SIZE; 1337 memcpy(page_address(bi->bv_page), 1338 page_address(pbio->bi_io_vec[j].bv_page), 1339 PAGE_SIZE); 1340 } 1341 1342 } 1343 } 1344 } 1345 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { 1346 /* ouch - failed to read all of that. 1347 * Try some synchronous reads of other devices to get 1348 * good data, much like with normal read errors. Only 1349 * read into the pages we already have so we don't 1350 * need to re-issue the read request. 1351 * We don't need to freeze the array, because being in an 1352 * active sync request, there is no normal IO, and 1353 * no overlapping syncs. 1354 */ 1355 sector_t sect = r1_bio->sector; 1356 int sectors = r1_bio->sectors; 1357 int idx = 0; 1358 1359 while(sectors) { 1360 int s = sectors; 1361 int d = r1_bio->read_disk; 1362 int success = 0; 1363 mdk_rdev_t *rdev; 1364 1365 if (s > (PAGE_SIZE>>9)) 1366 s = PAGE_SIZE >> 9; 1367 do { 1368 if (r1_bio->bios[d]->bi_end_io == end_sync_read) { 1369 /* No rcu protection needed here devices 1370 * can only be removed when no resync is 1371 * active, and resync is currently active 1372 */ 1373 rdev = conf->mirrors[d].rdev; 1374 if (sync_page_io(rdev->bdev, 1375 sect + rdev->data_offset, 1376 s<<9, 1377 bio->bi_io_vec[idx].bv_page, 1378 READ)) { 1379 success = 1; 1380 break; 1381 } 1382 } 1383 d++; 1384 if (d == conf->raid_disks) 1385 d = 0; 1386 } while (!success && d != r1_bio->read_disk); 1387 1388 if (success) { 1389 int start = d; 1390 /* write it back and re-read */ 1391 set_bit(R1BIO_Uptodate, &r1_bio->state); 1392 while (d != r1_bio->read_disk) { 1393 if (d == 0) 1394 d = conf->raid_disks; 1395 d--; 1396 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1397 continue; 1398 rdev = conf->mirrors[d].rdev; 1399 atomic_add(s, &rdev->corrected_errors); 1400 if (sync_page_io(rdev->bdev, 1401 sect + rdev->data_offset, 1402 s<<9, 1403 bio->bi_io_vec[idx].bv_page, 1404 WRITE) == 0) 1405 md_error(mddev, rdev); 1406 } 1407 d = start; 1408 while (d != r1_bio->read_disk) { 1409 if (d == 0) 1410 d = conf->raid_disks; 1411 d--; 1412 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1413 continue; 1414 rdev = conf->mirrors[d].rdev; 1415 if (sync_page_io(rdev->bdev, 1416 sect + rdev->data_offset, 1417 s<<9, 1418 bio->bi_io_vec[idx].bv_page, 1419 READ) == 0) 1420 md_error(mddev, rdev); 1421 } 1422 } else { 1423 char b[BDEVNAME_SIZE]; 1424 /* Cannot read from anywhere, array is toast */ 1425 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); 1426 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error" 1427 " for block %llu\n", 1428 bdevname(bio->bi_bdev,b), 1429 (unsigned long long)r1_bio->sector); 1430 md_done_sync(mddev, r1_bio->sectors, 0); 1431 put_buf(r1_bio); 1432 return; 1433 } 1434 sectors -= s; 1435 sect += s; 1436 idx ++; 1437 } 1438 } 1439 1440 /* 1441 * schedule writes 1442 */ 1443 atomic_set(&r1_bio->remaining, 1); 1444 for (i = 0; i < disks ; i++) { 1445 wbio = r1_bio->bios[i]; 1446 if (wbio->bi_end_io == NULL || 1447 (wbio->bi_end_io == end_sync_read && 1448 (i == r1_bio->read_disk || 1449 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) 1450 continue; 1451 1452 wbio->bi_rw = WRITE; 1453 wbio->bi_end_io = end_sync_write; 1454 atomic_inc(&r1_bio->remaining); 1455 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); 1456 1457 generic_make_request(wbio); 1458 } 1459 1460 if (atomic_dec_and_test(&r1_bio->remaining)) { 1461 /* if we're here, all write(s) have completed, so clean up */ 1462 md_done_sync(mddev, r1_bio->sectors, 1); 1463 put_buf(r1_bio); 1464 } 1465 } 1466 1467 /* 1468 * This is a kernel thread which: 1469 * 1470 * 1. Retries failed read operations on working mirrors. 1471 * 2. Updates the raid superblock when problems encounter. 1472 * 3. Performs writes following reads for array syncronising. 1473 */ 1474 1475 static void fix_read_error(conf_t *conf, int read_disk, 1476 sector_t sect, int sectors) 1477 { 1478 mddev_t *mddev = conf->mddev; 1479 while(sectors) { 1480 int s = sectors; 1481 int d = read_disk; 1482 int success = 0; 1483 int start; 1484 mdk_rdev_t *rdev; 1485 1486 if (s > (PAGE_SIZE>>9)) 1487 s = PAGE_SIZE >> 9; 1488 1489 do { 1490 /* Note: no rcu protection needed here 1491 * as this is synchronous in the raid1d thread 1492 * which is the thread that might remove 1493 * a device. If raid1d ever becomes multi-threaded.... 1494 */ 1495 rdev = conf->mirrors[d].rdev; 1496 if (rdev && 1497 test_bit(In_sync, &rdev->flags) && 1498 sync_page_io(rdev->bdev, 1499 sect + rdev->data_offset, 1500 s<<9, 1501 conf->tmppage, READ)) 1502 success = 1; 1503 else { 1504 d++; 1505 if (d == conf->raid_disks) 1506 d = 0; 1507 } 1508 } while (!success && d != read_disk); 1509 1510 if (!success) { 1511 /* Cannot read from anywhere -- bye bye array */ 1512 md_error(mddev, conf->mirrors[read_disk].rdev); 1513 break; 1514 } 1515 /* write it back and re-read */ 1516 start = d; 1517 while (d != read_disk) { 1518 if (d==0) 1519 d = conf->raid_disks; 1520 d--; 1521 rdev = conf->mirrors[d].rdev; 1522 if (rdev && 1523 test_bit(In_sync, &rdev->flags)) { 1524 if (sync_page_io(rdev->bdev, 1525 sect + rdev->data_offset, 1526 s<<9, conf->tmppage, WRITE) 1527 == 0) 1528 /* Well, this device is dead */ 1529 md_error(mddev, rdev); 1530 } 1531 } 1532 d = start; 1533 while (d != read_disk) { 1534 char b[BDEVNAME_SIZE]; 1535 if (d==0) 1536 d = conf->raid_disks; 1537 d--; 1538 rdev = conf->mirrors[d].rdev; 1539 if (rdev && 1540 test_bit(In_sync, &rdev->flags)) { 1541 if (sync_page_io(rdev->bdev, 1542 sect + rdev->data_offset, 1543 s<<9, conf->tmppage, READ) 1544 == 0) 1545 /* Well, this device is dead */ 1546 md_error(mddev, rdev); 1547 else { 1548 atomic_add(s, &rdev->corrected_errors); 1549 printk(KERN_INFO 1550 "raid1:%s: read error corrected " 1551 "(%d sectors at %llu on %s)\n", 1552 mdname(mddev), s, 1553 (unsigned long long)(sect + 1554 rdev->data_offset), 1555 bdevname(rdev->bdev, b)); 1556 } 1557 } 1558 } 1559 sectors -= s; 1560 sect += s; 1561 } 1562 } 1563 1564 static void raid1d(mddev_t *mddev) 1565 { 1566 r1bio_t *r1_bio; 1567 struct bio *bio; 1568 unsigned long flags; 1569 conf_t *conf = mddev->private; 1570 struct list_head *head = &conf->retry_list; 1571 int unplug=0; 1572 mdk_rdev_t *rdev; 1573 1574 md_check_recovery(mddev); 1575 1576 for (;;) { 1577 char b[BDEVNAME_SIZE]; 1578 1579 unplug += flush_pending_writes(conf); 1580 1581 spin_lock_irqsave(&conf->device_lock, flags); 1582 if (list_empty(head)) { 1583 spin_unlock_irqrestore(&conf->device_lock, flags); 1584 break; 1585 } 1586 r1_bio = list_entry(head->prev, r1bio_t, retry_list); 1587 list_del(head->prev); 1588 conf->nr_queued--; 1589 spin_unlock_irqrestore(&conf->device_lock, flags); 1590 1591 mddev = r1_bio->mddev; 1592 conf = mddev->private; 1593 if (test_bit(R1BIO_IsSync, &r1_bio->state)) { 1594 sync_request_write(mddev, r1_bio); 1595 unplug = 1; 1596 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) { 1597 /* some requests in the r1bio were BIO_RW_BARRIER 1598 * requests which failed with -EOPNOTSUPP. Hohumm.. 1599 * Better resubmit without the barrier. 1600 * We know which devices to resubmit for, because 1601 * all others have had their bios[] entry cleared. 1602 * We already have a nr_pending reference on these rdevs. 1603 */ 1604 int i; 1605 const bool do_sync = bio_rw_flagged(r1_bio->master_bio, BIO_RW_SYNCIO); 1606 clear_bit(R1BIO_BarrierRetry, &r1_bio->state); 1607 clear_bit(R1BIO_Barrier, &r1_bio->state); 1608 for (i=0; i < conf->raid_disks; i++) 1609 if (r1_bio->bios[i]) 1610 atomic_inc(&r1_bio->remaining); 1611 for (i=0; i < conf->raid_disks; i++) 1612 if (r1_bio->bios[i]) { 1613 struct bio_vec *bvec; 1614 int j; 1615 1616 bio = bio_clone(r1_bio->master_bio, GFP_NOIO); 1617 /* copy pages from the failed bio, as 1618 * this might be a write-behind device */ 1619 __bio_for_each_segment(bvec, bio, j, 0) 1620 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page; 1621 bio_put(r1_bio->bios[i]); 1622 bio->bi_sector = r1_bio->sector + 1623 conf->mirrors[i].rdev->data_offset; 1624 bio->bi_bdev = conf->mirrors[i].rdev->bdev; 1625 bio->bi_end_io = raid1_end_write_request; 1626 bio->bi_rw = WRITE | do_sync; 1627 bio->bi_private = r1_bio; 1628 r1_bio->bios[i] = bio; 1629 generic_make_request(bio); 1630 } 1631 } else { 1632 int disk; 1633 1634 /* we got a read error. Maybe the drive is bad. Maybe just 1635 * the block and we can fix it. 1636 * We freeze all other IO, and try reading the block from 1637 * other devices. When we find one, we re-write 1638 * and check it that fixes the read error. 1639 * This is all done synchronously while the array is 1640 * frozen 1641 */ 1642 if (mddev->ro == 0) { 1643 freeze_array(conf); 1644 fix_read_error(conf, r1_bio->read_disk, 1645 r1_bio->sector, 1646 r1_bio->sectors); 1647 unfreeze_array(conf); 1648 } 1649 1650 bio = r1_bio->bios[r1_bio->read_disk]; 1651 if ((disk=read_balance(conf, r1_bio)) == -1 || 1652 disk == r1_bio->read_disk) { 1653 printk(KERN_ALERT "raid1: %s: unrecoverable I/O" 1654 " read error for block %llu\n", 1655 bdevname(bio->bi_bdev,b), 1656 (unsigned long long)r1_bio->sector); 1657 raid_end_bio_io(r1_bio); 1658 } else { 1659 const bool do_sync = bio_rw_flagged(r1_bio->master_bio, BIO_RW_SYNCIO); 1660 r1_bio->bios[r1_bio->read_disk] = 1661 mddev->ro ? IO_BLOCKED : NULL; 1662 r1_bio->read_disk = disk; 1663 bio_put(bio); 1664 bio = bio_clone(r1_bio->master_bio, GFP_NOIO); 1665 r1_bio->bios[r1_bio->read_disk] = bio; 1666 rdev = conf->mirrors[disk].rdev; 1667 if (printk_ratelimit()) 1668 printk(KERN_ERR "raid1: %s: redirecting sector %llu to" 1669 " another mirror\n", 1670 bdevname(rdev->bdev,b), 1671 (unsigned long long)r1_bio->sector); 1672 bio->bi_sector = r1_bio->sector + rdev->data_offset; 1673 bio->bi_bdev = rdev->bdev; 1674 bio->bi_end_io = raid1_end_read_request; 1675 bio->bi_rw = READ | do_sync; 1676 bio->bi_private = r1_bio; 1677 unplug = 1; 1678 generic_make_request(bio); 1679 } 1680 } 1681 } 1682 if (unplug) 1683 unplug_slaves(mddev); 1684 } 1685 1686 1687 static int init_resync(conf_t *conf) 1688 { 1689 int buffs; 1690 1691 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; 1692 BUG_ON(conf->r1buf_pool); 1693 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, 1694 conf->poolinfo); 1695 if (!conf->r1buf_pool) 1696 return -ENOMEM; 1697 conf->next_resync = 0; 1698 return 0; 1699 } 1700 1701 /* 1702 * perform a "sync" on one "block" 1703 * 1704 * We need to make sure that no normal I/O request - particularly write 1705 * requests - conflict with active sync requests. 1706 * 1707 * This is achieved by tracking pending requests and a 'barrier' concept 1708 * that can be installed to exclude normal IO requests. 1709 */ 1710 1711 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) 1712 { 1713 conf_t *conf = mddev->private; 1714 r1bio_t *r1_bio; 1715 struct bio *bio; 1716 sector_t max_sector, nr_sectors; 1717 int disk = -1; 1718 int i; 1719 int wonly = -1; 1720 int write_targets = 0, read_targets = 0; 1721 int sync_blocks; 1722 int still_degraded = 0; 1723 1724 if (!conf->r1buf_pool) 1725 { 1726 /* 1727 printk("sync start - bitmap %p\n", mddev->bitmap); 1728 */ 1729 if (init_resync(conf)) 1730 return 0; 1731 } 1732 1733 max_sector = mddev->dev_sectors; 1734 if (sector_nr >= max_sector) { 1735 /* If we aborted, we need to abort the 1736 * sync on the 'current' bitmap chunk (there will 1737 * only be one in raid1 resync. 1738 * We can find the current addess in mddev->curr_resync 1739 */ 1740 if (mddev->curr_resync < max_sector) /* aborted */ 1741 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 1742 &sync_blocks, 1); 1743 else /* completed sync */ 1744 conf->fullsync = 0; 1745 1746 bitmap_close_sync(mddev->bitmap); 1747 close_sync(conf); 1748 return 0; 1749 } 1750 1751 if (mddev->bitmap == NULL && 1752 mddev->recovery_cp == MaxSector && 1753 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 1754 conf->fullsync == 0) { 1755 *skipped = 1; 1756 return max_sector - sector_nr; 1757 } 1758 /* before building a request, check if we can skip these blocks.. 1759 * This call the bitmap_start_sync doesn't actually record anything 1760 */ 1761 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 1762 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1763 /* We can skip this block, and probably several more */ 1764 *skipped = 1; 1765 return sync_blocks; 1766 } 1767 /* 1768 * If there is non-resync activity waiting for a turn, 1769 * and resync is going fast enough, 1770 * then let it though before starting on this new sync request. 1771 */ 1772 if (!go_faster && conf->nr_waiting) 1773 msleep_interruptible(1000); 1774 1775 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 1776 raise_barrier(conf); 1777 1778 conf->next_resync = sector_nr; 1779 1780 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); 1781 rcu_read_lock(); 1782 /* 1783 * If we get a correctably read error during resync or recovery, 1784 * we might want to read from a different device. So we 1785 * flag all drives that could conceivably be read from for READ, 1786 * and any others (which will be non-In_sync devices) for WRITE. 1787 * If a read fails, we try reading from something else for which READ 1788 * is OK. 1789 */ 1790 1791 r1_bio->mddev = mddev; 1792 r1_bio->sector = sector_nr; 1793 r1_bio->state = 0; 1794 set_bit(R1BIO_IsSync, &r1_bio->state); 1795 1796 for (i=0; i < conf->raid_disks; i++) { 1797 mdk_rdev_t *rdev; 1798 bio = r1_bio->bios[i]; 1799 1800 /* take from bio_init */ 1801 bio->bi_next = NULL; 1802 bio->bi_flags |= 1 << BIO_UPTODATE; 1803 bio->bi_rw = READ; 1804 bio->bi_vcnt = 0; 1805 bio->bi_idx = 0; 1806 bio->bi_phys_segments = 0; 1807 bio->bi_size = 0; 1808 bio->bi_end_io = NULL; 1809 bio->bi_private = NULL; 1810 1811 rdev = rcu_dereference(conf->mirrors[i].rdev); 1812 if (rdev == NULL || 1813 test_bit(Faulty, &rdev->flags)) { 1814 still_degraded = 1; 1815 continue; 1816 } else if (!test_bit(In_sync, &rdev->flags)) { 1817 bio->bi_rw = WRITE; 1818 bio->bi_end_io = end_sync_write; 1819 write_targets ++; 1820 } else { 1821 /* may need to read from here */ 1822 bio->bi_rw = READ; 1823 bio->bi_end_io = end_sync_read; 1824 if (test_bit(WriteMostly, &rdev->flags)) { 1825 if (wonly < 0) 1826 wonly = i; 1827 } else { 1828 if (disk < 0) 1829 disk = i; 1830 } 1831 read_targets++; 1832 } 1833 atomic_inc(&rdev->nr_pending); 1834 bio->bi_sector = sector_nr + rdev->data_offset; 1835 bio->bi_bdev = rdev->bdev; 1836 bio->bi_private = r1_bio; 1837 } 1838 rcu_read_unlock(); 1839 if (disk < 0) 1840 disk = wonly; 1841 r1_bio->read_disk = disk; 1842 1843 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) 1844 /* extra read targets are also write targets */ 1845 write_targets += read_targets-1; 1846 1847 if (write_targets == 0 || read_targets == 0) { 1848 /* There is nowhere to write, so all non-sync 1849 * drives must be failed - so we are finished 1850 */ 1851 sector_t rv = max_sector - sector_nr; 1852 *skipped = 1; 1853 put_buf(r1_bio); 1854 return rv; 1855 } 1856 1857 if (max_sector > mddev->resync_max) 1858 max_sector = mddev->resync_max; /* Don't do IO beyond here */ 1859 nr_sectors = 0; 1860 sync_blocks = 0; 1861 do { 1862 struct page *page; 1863 int len = PAGE_SIZE; 1864 if (sector_nr + (len>>9) > max_sector) 1865 len = (max_sector - sector_nr) << 9; 1866 if (len == 0) 1867 break; 1868 if (sync_blocks == 0) { 1869 if (!bitmap_start_sync(mddev->bitmap, sector_nr, 1870 &sync_blocks, still_degraded) && 1871 !conf->fullsync && 1872 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 1873 break; 1874 BUG_ON(sync_blocks < (PAGE_SIZE>>9)); 1875 if (len > (sync_blocks<<9)) 1876 len = sync_blocks<<9; 1877 } 1878 1879 for (i=0 ; i < conf->raid_disks; i++) { 1880 bio = r1_bio->bios[i]; 1881 if (bio->bi_end_io) { 1882 page = bio->bi_io_vec[bio->bi_vcnt].bv_page; 1883 if (bio_add_page(bio, page, len, 0) == 0) { 1884 /* stop here */ 1885 bio->bi_io_vec[bio->bi_vcnt].bv_page = page; 1886 while (i > 0) { 1887 i--; 1888 bio = r1_bio->bios[i]; 1889 if (bio->bi_end_io==NULL) 1890 continue; 1891 /* remove last page from this bio */ 1892 bio->bi_vcnt--; 1893 bio->bi_size -= len; 1894 bio->bi_flags &= ~(1<< BIO_SEG_VALID); 1895 } 1896 goto bio_full; 1897 } 1898 } 1899 } 1900 nr_sectors += len>>9; 1901 sector_nr += len>>9; 1902 sync_blocks -= (len>>9); 1903 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); 1904 bio_full: 1905 r1_bio->sectors = nr_sectors; 1906 1907 /* For a user-requested sync, we read all readable devices and do a 1908 * compare 1909 */ 1910 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1911 atomic_set(&r1_bio->remaining, read_targets); 1912 for (i=0; i<conf->raid_disks; i++) { 1913 bio = r1_bio->bios[i]; 1914 if (bio->bi_end_io == end_sync_read) { 1915 md_sync_acct(bio->bi_bdev, nr_sectors); 1916 generic_make_request(bio); 1917 } 1918 } 1919 } else { 1920 atomic_set(&r1_bio->remaining, 1); 1921 bio = r1_bio->bios[r1_bio->read_disk]; 1922 md_sync_acct(bio->bi_bdev, nr_sectors); 1923 generic_make_request(bio); 1924 1925 } 1926 return nr_sectors; 1927 } 1928 1929 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks) 1930 { 1931 if (sectors) 1932 return sectors; 1933 1934 return mddev->dev_sectors; 1935 } 1936 1937 static int run(mddev_t *mddev) 1938 { 1939 conf_t *conf; 1940 int i, j, disk_idx; 1941 mirror_info_t *disk; 1942 mdk_rdev_t *rdev; 1943 1944 if (mddev->level != 1) { 1945 printk("raid1: %s: raid level not set to mirroring (%d)\n", 1946 mdname(mddev), mddev->level); 1947 goto out; 1948 } 1949 if (mddev->reshape_position != MaxSector) { 1950 printk("raid1: %s: reshape_position set but not supported\n", 1951 mdname(mddev)); 1952 goto out; 1953 } 1954 /* 1955 * copy the already verified devices into our private RAID1 1956 * bookkeeping area. [whatever we allocate in run(), 1957 * should be freed in stop()] 1958 */ 1959 conf = kzalloc(sizeof(conf_t), GFP_KERNEL); 1960 mddev->private = conf; 1961 if (!conf) 1962 goto out_no_mem; 1963 1964 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, 1965 GFP_KERNEL); 1966 if (!conf->mirrors) 1967 goto out_no_mem; 1968 1969 conf->tmppage = alloc_page(GFP_KERNEL); 1970 if (!conf->tmppage) 1971 goto out_no_mem; 1972 1973 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL); 1974 if (!conf->poolinfo) 1975 goto out_no_mem; 1976 conf->poolinfo->mddev = mddev; 1977 conf->poolinfo->raid_disks = mddev->raid_disks; 1978 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 1979 r1bio_pool_free, 1980 conf->poolinfo); 1981 if (!conf->r1bio_pool) 1982 goto out_no_mem; 1983 1984 spin_lock_init(&conf->device_lock); 1985 mddev->queue->queue_lock = &conf->device_lock; 1986 1987 list_for_each_entry(rdev, &mddev->disks, same_set) { 1988 disk_idx = rdev->raid_disk; 1989 if (disk_idx >= mddev->raid_disks 1990 || disk_idx < 0) 1991 continue; 1992 disk = conf->mirrors + disk_idx; 1993 1994 disk->rdev = rdev; 1995 disk_stack_limits(mddev->gendisk, rdev->bdev, 1996 rdev->data_offset << 9); 1997 /* as we don't honour merge_bvec_fn, we must never risk 1998 * violating it, so limit ->max_sector to one PAGE, as 1999 * a one page request is never in violation. 2000 */ 2001 if (rdev->bdev->bd_disk->queue->merge_bvec_fn && 2002 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) 2003 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); 2004 2005 disk->head_position = 0; 2006 } 2007 conf->raid_disks = mddev->raid_disks; 2008 conf->mddev = mddev; 2009 INIT_LIST_HEAD(&conf->retry_list); 2010 2011 spin_lock_init(&conf->resync_lock); 2012 init_waitqueue_head(&conf->wait_barrier); 2013 2014 bio_list_init(&conf->pending_bio_list); 2015 bio_list_init(&conf->flushing_bio_list); 2016 2017 2018 mddev->degraded = 0; 2019 for (i = 0; i < conf->raid_disks; i++) { 2020 2021 disk = conf->mirrors + i; 2022 2023 if (!disk->rdev || 2024 !test_bit(In_sync, &disk->rdev->flags)) { 2025 disk->head_position = 0; 2026 mddev->degraded++; 2027 if (disk->rdev) 2028 conf->fullsync = 1; 2029 } 2030 } 2031 if (mddev->degraded == conf->raid_disks) { 2032 printk(KERN_ERR "raid1: no operational mirrors for %s\n", 2033 mdname(mddev)); 2034 goto out_free_conf; 2035 } 2036 if (conf->raid_disks - mddev->degraded == 1) 2037 mddev->recovery_cp = MaxSector; 2038 2039 /* 2040 * find the first working one and use it as a starting point 2041 * to read balancing. 2042 */ 2043 for (j = 0; j < conf->raid_disks && 2044 (!conf->mirrors[j].rdev || 2045 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++) 2046 /* nothing */; 2047 conf->last_used = j; 2048 2049 2050 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1"); 2051 if (!mddev->thread) { 2052 printk(KERN_ERR 2053 "raid1: couldn't allocate thread for %s\n", 2054 mdname(mddev)); 2055 goto out_free_conf; 2056 } 2057 2058 if (mddev->recovery_cp != MaxSector) 2059 printk(KERN_NOTICE "raid1: %s is not clean" 2060 " -- starting background reconstruction\n", 2061 mdname(mddev)); 2062 printk(KERN_INFO 2063 "raid1: raid set %s active with %d out of %d mirrors\n", 2064 mdname(mddev), mddev->raid_disks - mddev->degraded, 2065 mddev->raid_disks); 2066 /* 2067 * Ok, everything is just fine now 2068 */ 2069 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); 2070 2071 mddev->queue->unplug_fn = raid1_unplug; 2072 mddev->queue->backing_dev_info.congested_fn = raid1_congested; 2073 mddev->queue->backing_dev_info.congested_data = mddev; 2074 md_integrity_register(mddev); 2075 return 0; 2076 2077 out_no_mem: 2078 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n", 2079 mdname(mddev)); 2080 2081 out_free_conf: 2082 if (conf) { 2083 if (conf->r1bio_pool) 2084 mempool_destroy(conf->r1bio_pool); 2085 kfree(conf->mirrors); 2086 safe_put_page(conf->tmppage); 2087 kfree(conf->poolinfo); 2088 kfree(conf); 2089 mddev->private = NULL; 2090 } 2091 out: 2092 return -EIO; 2093 } 2094 2095 static int stop(mddev_t *mddev) 2096 { 2097 conf_t *conf = mddev->private; 2098 struct bitmap *bitmap = mddev->bitmap; 2099 int behind_wait = 0; 2100 2101 /* wait for behind writes to complete */ 2102 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) { 2103 behind_wait++; 2104 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait); 2105 set_current_state(TASK_UNINTERRUPTIBLE); 2106 schedule_timeout(HZ); /* wait a second */ 2107 /* need to kick something here to make sure I/O goes? */ 2108 } 2109 2110 raise_barrier(conf); 2111 lower_barrier(conf); 2112 2113 md_unregister_thread(mddev->thread); 2114 mddev->thread = NULL; 2115 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 2116 if (conf->r1bio_pool) 2117 mempool_destroy(conf->r1bio_pool); 2118 kfree(conf->mirrors); 2119 kfree(conf->poolinfo); 2120 kfree(conf); 2121 mddev->private = NULL; 2122 return 0; 2123 } 2124 2125 static int raid1_resize(mddev_t *mddev, sector_t sectors) 2126 { 2127 /* no resync is happening, and there is enough space 2128 * on all devices, so we can resize. 2129 * We need to make sure resync covers any new space. 2130 * If the array is shrinking we should possibly wait until 2131 * any io in the removed space completes, but it hardly seems 2132 * worth it. 2133 */ 2134 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0)); 2135 if (mddev->array_sectors > raid1_size(mddev, sectors, 0)) 2136 return -EINVAL; 2137 set_capacity(mddev->gendisk, mddev->array_sectors); 2138 mddev->changed = 1; 2139 revalidate_disk(mddev->gendisk); 2140 if (sectors > mddev->dev_sectors && 2141 mddev->recovery_cp == MaxSector) { 2142 mddev->recovery_cp = mddev->dev_sectors; 2143 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 2144 } 2145 mddev->dev_sectors = sectors; 2146 mddev->resync_max_sectors = sectors; 2147 return 0; 2148 } 2149 2150 static int raid1_reshape(mddev_t *mddev) 2151 { 2152 /* We need to: 2153 * 1/ resize the r1bio_pool 2154 * 2/ resize conf->mirrors 2155 * 2156 * We allocate a new r1bio_pool if we can. 2157 * Then raise a device barrier and wait until all IO stops. 2158 * Then resize conf->mirrors and swap in the new r1bio pool. 2159 * 2160 * At the same time, we "pack" the devices so that all the missing 2161 * devices have the higher raid_disk numbers. 2162 */ 2163 mempool_t *newpool, *oldpool; 2164 struct pool_info *newpoolinfo; 2165 mirror_info_t *newmirrors; 2166 conf_t *conf = mddev->private; 2167 int cnt, raid_disks; 2168 unsigned long flags; 2169 int d, d2, err; 2170 2171 /* Cannot change chunk_size, layout, or level */ 2172 if (mddev->chunk_sectors != mddev->new_chunk_sectors || 2173 mddev->layout != mddev->new_layout || 2174 mddev->level != mddev->new_level) { 2175 mddev->new_chunk_sectors = mddev->chunk_sectors; 2176 mddev->new_layout = mddev->layout; 2177 mddev->new_level = mddev->level; 2178 return -EINVAL; 2179 } 2180 2181 err = md_allow_write(mddev); 2182 if (err) 2183 return err; 2184 2185 raid_disks = mddev->raid_disks + mddev->delta_disks; 2186 2187 if (raid_disks < conf->raid_disks) { 2188 cnt=0; 2189 for (d= 0; d < conf->raid_disks; d++) 2190 if (conf->mirrors[d].rdev) 2191 cnt++; 2192 if (cnt > raid_disks) 2193 return -EBUSY; 2194 } 2195 2196 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); 2197 if (!newpoolinfo) 2198 return -ENOMEM; 2199 newpoolinfo->mddev = mddev; 2200 newpoolinfo->raid_disks = raid_disks; 2201 2202 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2203 r1bio_pool_free, newpoolinfo); 2204 if (!newpool) { 2205 kfree(newpoolinfo); 2206 return -ENOMEM; 2207 } 2208 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL); 2209 if (!newmirrors) { 2210 kfree(newpoolinfo); 2211 mempool_destroy(newpool); 2212 return -ENOMEM; 2213 } 2214 2215 raise_barrier(conf); 2216 2217 /* ok, everything is stopped */ 2218 oldpool = conf->r1bio_pool; 2219 conf->r1bio_pool = newpool; 2220 2221 for (d = d2 = 0; d < conf->raid_disks; d++) { 2222 mdk_rdev_t *rdev = conf->mirrors[d].rdev; 2223 if (rdev && rdev->raid_disk != d2) { 2224 char nm[20]; 2225 sprintf(nm, "rd%d", rdev->raid_disk); 2226 sysfs_remove_link(&mddev->kobj, nm); 2227 rdev->raid_disk = d2; 2228 sprintf(nm, "rd%d", rdev->raid_disk); 2229 sysfs_remove_link(&mddev->kobj, nm); 2230 if (sysfs_create_link(&mddev->kobj, 2231 &rdev->kobj, nm)) 2232 printk(KERN_WARNING 2233 "md/raid1: cannot register " 2234 "%s for %s\n", 2235 nm, mdname(mddev)); 2236 } 2237 if (rdev) 2238 newmirrors[d2++].rdev = rdev; 2239 } 2240 kfree(conf->mirrors); 2241 conf->mirrors = newmirrors; 2242 kfree(conf->poolinfo); 2243 conf->poolinfo = newpoolinfo; 2244 2245 spin_lock_irqsave(&conf->device_lock, flags); 2246 mddev->degraded += (raid_disks - conf->raid_disks); 2247 spin_unlock_irqrestore(&conf->device_lock, flags); 2248 conf->raid_disks = mddev->raid_disks = raid_disks; 2249 mddev->delta_disks = 0; 2250 2251 conf->last_used = 0; /* just make sure it is in-range */ 2252 lower_barrier(conf); 2253 2254 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 2255 md_wakeup_thread(mddev->thread); 2256 2257 mempool_destroy(oldpool); 2258 return 0; 2259 } 2260 2261 static void raid1_quiesce(mddev_t *mddev, int state) 2262 { 2263 conf_t *conf = mddev->private; 2264 2265 switch(state) { 2266 case 1: 2267 raise_barrier(conf); 2268 break; 2269 case 0: 2270 lower_barrier(conf); 2271 break; 2272 } 2273 } 2274 2275 2276 static struct mdk_personality raid1_personality = 2277 { 2278 .name = "raid1", 2279 .level = 1, 2280 .owner = THIS_MODULE, 2281 .make_request = make_request, 2282 .run = run, 2283 .stop = stop, 2284 .status = status, 2285 .error_handler = error, 2286 .hot_add_disk = raid1_add_disk, 2287 .hot_remove_disk= raid1_remove_disk, 2288 .spare_active = raid1_spare_active, 2289 .sync_request = sync_request, 2290 .resize = raid1_resize, 2291 .size = raid1_size, 2292 .check_reshape = raid1_reshape, 2293 .quiesce = raid1_quiesce, 2294 }; 2295 2296 static int __init raid_init(void) 2297 { 2298 return register_md_personality(&raid1_personality); 2299 } 2300 2301 static void raid_exit(void) 2302 { 2303 unregister_md_personality(&raid1_personality); 2304 } 2305 2306 module_init(raid_init); 2307 module_exit(raid_exit); 2308 MODULE_LICENSE("GPL"); 2309 MODULE_ALIAS("md-personality-3"); /* RAID1 */ 2310 MODULE_ALIAS("md-raid1"); 2311 MODULE_ALIAS("md-level-1"); 2312