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 int do_sync = bio_sync(bio); 786 int cpu, do_barriers; 787 mdk_rdev_t *blocked_rdev; 788 789 /* 790 * Register the new request and wait if the reconstruction 791 * thread has put up a bar for new requests. 792 * Continue immediately if no resync is active currently. 793 * We test barriers_work *after* md_write_start as md_write_start 794 * may cause the first superblock write, and that will check out 795 * if barriers work. 796 */ 797 798 md_write_start(mddev, bio); /* wait on superblock update early */ 799 800 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) { 801 if (rw == WRITE) 802 md_write_end(mddev); 803 bio_endio(bio, -EOPNOTSUPP); 804 return 0; 805 } 806 807 wait_barrier(conf); 808 809 bitmap = mddev->bitmap; 810 811 cpu = part_stat_lock(); 812 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); 813 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], 814 bio_sectors(bio)); 815 part_stat_unlock(); 816 817 /* 818 * make_request() can abort the operation when READA is being 819 * used and no empty request is available. 820 * 821 */ 822 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); 823 824 r1_bio->master_bio = bio; 825 r1_bio->sectors = bio->bi_size >> 9; 826 r1_bio->state = 0; 827 r1_bio->mddev = mddev; 828 r1_bio->sector = bio->bi_sector; 829 830 if (rw == READ) { 831 /* 832 * read balancing logic: 833 */ 834 int rdisk = read_balance(conf, r1_bio); 835 836 if (rdisk < 0) { 837 /* couldn't find anywhere to read from */ 838 raid_end_bio_io(r1_bio); 839 return 0; 840 } 841 mirror = conf->mirrors + rdisk; 842 843 r1_bio->read_disk = rdisk; 844 845 read_bio = bio_clone(bio, GFP_NOIO); 846 847 r1_bio->bios[rdisk] = read_bio; 848 849 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; 850 read_bio->bi_bdev = mirror->rdev->bdev; 851 read_bio->bi_end_io = raid1_end_read_request; 852 read_bio->bi_rw = READ | do_sync; 853 read_bio->bi_private = r1_bio; 854 855 generic_make_request(read_bio); 856 return 0; 857 } 858 859 /* 860 * WRITE: 861 */ 862 /* first select target devices under spinlock and 863 * inc refcount on their rdev. Record them by setting 864 * bios[x] to bio 865 */ 866 disks = conf->raid_disks; 867 #if 0 868 { static int first=1; 869 if (first) printk("First Write sector %llu disks %d\n", 870 (unsigned long long)r1_bio->sector, disks); 871 first = 0; 872 } 873 #endif 874 retry_write: 875 blocked_rdev = NULL; 876 rcu_read_lock(); 877 for (i = 0; i < disks; i++) { 878 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 879 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { 880 atomic_inc(&rdev->nr_pending); 881 blocked_rdev = rdev; 882 break; 883 } 884 if (rdev && !test_bit(Faulty, &rdev->flags)) { 885 atomic_inc(&rdev->nr_pending); 886 if (test_bit(Faulty, &rdev->flags)) { 887 rdev_dec_pending(rdev, mddev); 888 r1_bio->bios[i] = NULL; 889 } else 890 r1_bio->bios[i] = bio; 891 targets++; 892 } else 893 r1_bio->bios[i] = NULL; 894 } 895 rcu_read_unlock(); 896 897 if (unlikely(blocked_rdev)) { 898 /* Wait for this device to become unblocked */ 899 int j; 900 901 for (j = 0; j < i; j++) 902 if (r1_bio->bios[j]) 903 rdev_dec_pending(conf->mirrors[j].rdev, mddev); 904 905 allow_barrier(conf); 906 md_wait_for_blocked_rdev(blocked_rdev, mddev); 907 wait_barrier(conf); 908 goto retry_write; 909 } 910 911 BUG_ON(targets == 0); /* we never fail the last device */ 912 913 if (targets < conf->raid_disks) { 914 /* array is degraded, we will not clear the bitmap 915 * on I/O completion (see raid1_end_write_request) */ 916 set_bit(R1BIO_Degraded, &r1_bio->state); 917 } 918 919 /* do behind I/O ? */ 920 if (bitmap && 921 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind && 922 (behind_pages = alloc_behind_pages(bio)) != NULL) 923 set_bit(R1BIO_BehindIO, &r1_bio->state); 924 925 atomic_set(&r1_bio->remaining, 0); 926 atomic_set(&r1_bio->behind_remaining, 0); 927 928 do_barriers = bio_barrier(bio); 929 if (do_barriers) 930 set_bit(R1BIO_Barrier, &r1_bio->state); 931 932 bio_list_init(&bl); 933 for (i = 0; i < disks; i++) { 934 struct bio *mbio; 935 if (!r1_bio->bios[i]) 936 continue; 937 938 mbio = bio_clone(bio, GFP_NOIO); 939 r1_bio->bios[i] = mbio; 940 941 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; 942 mbio->bi_bdev = conf->mirrors[i].rdev->bdev; 943 mbio->bi_end_io = raid1_end_write_request; 944 mbio->bi_rw = WRITE | do_barriers | do_sync; 945 mbio->bi_private = r1_bio; 946 947 if (behind_pages) { 948 struct bio_vec *bvec; 949 int j; 950 951 /* Yes, I really want the '__' version so that 952 * we clear any unused pointer in the io_vec, rather 953 * than leave them unchanged. This is important 954 * because when we come to free the pages, we won't 955 * know the originial bi_idx, so we just free 956 * them all 957 */ 958 __bio_for_each_segment(bvec, mbio, j, 0) 959 bvec->bv_page = behind_pages[j]; 960 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) 961 atomic_inc(&r1_bio->behind_remaining); 962 } 963 964 atomic_inc(&r1_bio->remaining); 965 966 bio_list_add(&bl, mbio); 967 } 968 kfree(behind_pages); /* the behind pages are attached to the bios now */ 969 970 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors, 971 test_bit(R1BIO_BehindIO, &r1_bio->state)); 972 spin_lock_irqsave(&conf->device_lock, flags); 973 bio_list_merge(&conf->pending_bio_list, &bl); 974 bio_list_init(&bl); 975 976 blk_plug_device(mddev->queue); 977 spin_unlock_irqrestore(&conf->device_lock, flags); 978 979 /* In case raid1d snuck into freeze_array */ 980 wake_up(&conf->wait_barrier); 981 982 if (do_sync) 983 md_wakeup_thread(mddev->thread); 984 #if 0 985 while ((bio = bio_list_pop(&bl)) != NULL) 986 generic_make_request(bio); 987 #endif 988 989 return 0; 990 } 991 992 static void status(struct seq_file *seq, mddev_t *mddev) 993 { 994 conf_t *conf = mddev->private; 995 int i; 996 997 seq_printf(seq, " [%d/%d] [", conf->raid_disks, 998 conf->raid_disks - mddev->degraded); 999 rcu_read_lock(); 1000 for (i = 0; i < conf->raid_disks; i++) { 1001 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 1002 seq_printf(seq, "%s", 1003 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); 1004 } 1005 rcu_read_unlock(); 1006 seq_printf(seq, "]"); 1007 } 1008 1009 1010 static void error(mddev_t *mddev, mdk_rdev_t *rdev) 1011 { 1012 char b[BDEVNAME_SIZE]; 1013 conf_t *conf = mddev->private; 1014 1015 /* 1016 * If it is not operational, then we have already marked it as dead 1017 * else if it is the last working disks, ignore the error, let the 1018 * next level up know. 1019 * else mark the drive as failed 1020 */ 1021 if (test_bit(In_sync, &rdev->flags) 1022 && (conf->raid_disks - mddev->degraded) == 1) { 1023 /* 1024 * Don't fail the drive, act as though we were just a 1025 * normal single drive. 1026 * However don't try a recovery from this drive as 1027 * it is very likely to fail. 1028 */ 1029 mddev->recovery_disabled = 1; 1030 return; 1031 } 1032 if (test_and_clear_bit(In_sync, &rdev->flags)) { 1033 unsigned long flags; 1034 spin_lock_irqsave(&conf->device_lock, flags); 1035 mddev->degraded++; 1036 set_bit(Faulty, &rdev->flags); 1037 spin_unlock_irqrestore(&conf->device_lock, flags); 1038 /* 1039 * if recovery is running, make sure it aborts. 1040 */ 1041 set_bit(MD_RECOVERY_INTR, &mddev->recovery); 1042 } else 1043 set_bit(Faulty, &rdev->flags); 1044 set_bit(MD_CHANGE_DEVS, &mddev->flags); 1045 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n" 1046 "raid1: Operation continuing on %d devices.\n", 1047 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); 1048 } 1049 1050 static void print_conf(conf_t *conf) 1051 { 1052 int i; 1053 1054 printk("RAID1 conf printout:\n"); 1055 if (!conf) { 1056 printk("(!conf)\n"); 1057 return; 1058 } 1059 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, 1060 conf->raid_disks); 1061 1062 rcu_read_lock(); 1063 for (i = 0; i < conf->raid_disks; i++) { 1064 char b[BDEVNAME_SIZE]; 1065 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); 1066 if (rdev) 1067 printk(" disk %d, wo:%d, o:%d, dev:%s\n", 1068 i, !test_bit(In_sync, &rdev->flags), 1069 !test_bit(Faulty, &rdev->flags), 1070 bdevname(rdev->bdev,b)); 1071 } 1072 rcu_read_unlock(); 1073 } 1074 1075 static void close_sync(conf_t *conf) 1076 { 1077 wait_barrier(conf); 1078 allow_barrier(conf); 1079 1080 mempool_destroy(conf->r1buf_pool); 1081 conf->r1buf_pool = NULL; 1082 } 1083 1084 static int raid1_spare_active(mddev_t *mddev) 1085 { 1086 int i; 1087 conf_t *conf = mddev->private; 1088 1089 /* 1090 * Find all failed disks within the RAID1 configuration 1091 * and mark them readable. 1092 * Called under mddev lock, so rcu protection not needed. 1093 */ 1094 for (i = 0; i < conf->raid_disks; i++) { 1095 mdk_rdev_t *rdev = conf->mirrors[i].rdev; 1096 if (rdev 1097 && !test_bit(Faulty, &rdev->flags) 1098 && !test_and_set_bit(In_sync, &rdev->flags)) { 1099 unsigned long flags; 1100 spin_lock_irqsave(&conf->device_lock, flags); 1101 mddev->degraded--; 1102 spin_unlock_irqrestore(&conf->device_lock, flags); 1103 } 1104 } 1105 1106 print_conf(conf); 1107 return 0; 1108 } 1109 1110 1111 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) 1112 { 1113 conf_t *conf = mddev->private; 1114 int err = -EEXIST; 1115 int mirror = 0; 1116 mirror_info_t *p; 1117 int first = 0; 1118 int last = mddev->raid_disks - 1; 1119 1120 if (rdev->raid_disk >= 0) 1121 first = last = rdev->raid_disk; 1122 1123 for (mirror = first; mirror <= last; mirror++) 1124 if ( !(p=conf->mirrors+mirror)->rdev) { 1125 1126 disk_stack_limits(mddev->gendisk, rdev->bdev, 1127 rdev->data_offset << 9); 1128 /* as we don't honour merge_bvec_fn, we must never risk 1129 * violating it, so limit ->max_sector to one PAGE, as 1130 * a one page request is never in violation. 1131 */ 1132 if (rdev->bdev->bd_disk->queue->merge_bvec_fn && 1133 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) 1134 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); 1135 1136 p->head_position = 0; 1137 rdev->raid_disk = mirror; 1138 err = 0; 1139 /* As all devices are equivalent, we don't need a full recovery 1140 * if this was recently any drive of the array 1141 */ 1142 if (rdev->saved_raid_disk < 0) 1143 conf->fullsync = 1; 1144 rcu_assign_pointer(p->rdev, rdev); 1145 break; 1146 } 1147 md_integrity_add_rdev(rdev, mddev); 1148 print_conf(conf); 1149 return err; 1150 } 1151 1152 static int raid1_remove_disk(mddev_t *mddev, int number) 1153 { 1154 conf_t *conf = mddev->private; 1155 int err = 0; 1156 mdk_rdev_t *rdev; 1157 mirror_info_t *p = conf->mirrors+ number; 1158 1159 print_conf(conf); 1160 rdev = p->rdev; 1161 if (rdev) { 1162 if (test_bit(In_sync, &rdev->flags) || 1163 atomic_read(&rdev->nr_pending)) { 1164 err = -EBUSY; 1165 goto abort; 1166 } 1167 /* Only remove non-faulty devices is recovery 1168 * is not possible. 1169 */ 1170 if (!test_bit(Faulty, &rdev->flags) && 1171 mddev->degraded < conf->raid_disks) { 1172 err = -EBUSY; 1173 goto abort; 1174 } 1175 p->rdev = NULL; 1176 synchronize_rcu(); 1177 if (atomic_read(&rdev->nr_pending)) { 1178 /* lost the race, try later */ 1179 err = -EBUSY; 1180 p->rdev = rdev; 1181 goto abort; 1182 } 1183 md_integrity_register(mddev); 1184 } 1185 abort: 1186 1187 print_conf(conf); 1188 return err; 1189 } 1190 1191 1192 static void end_sync_read(struct bio *bio, int error) 1193 { 1194 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 1195 int i; 1196 1197 for (i=r1_bio->mddev->raid_disks; i--; ) 1198 if (r1_bio->bios[i] == bio) 1199 break; 1200 BUG_ON(i < 0); 1201 update_head_pos(i, r1_bio); 1202 /* 1203 * we have read a block, now it needs to be re-written, 1204 * or re-read if the read failed. 1205 * We don't do much here, just schedule handling by raid1d 1206 */ 1207 if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 1208 set_bit(R1BIO_Uptodate, &r1_bio->state); 1209 1210 if (atomic_dec_and_test(&r1_bio->remaining)) 1211 reschedule_retry(r1_bio); 1212 } 1213 1214 static void end_sync_write(struct bio *bio, int error) 1215 { 1216 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 1217 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); 1218 mddev_t *mddev = r1_bio->mddev; 1219 conf_t *conf = mddev->private; 1220 int i; 1221 int mirror=0; 1222 1223 for (i = 0; i < conf->raid_disks; i++) 1224 if (r1_bio->bios[i] == bio) { 1225 mirror = i; 1226 break; 1227 } 1228 if (!uptodate) { 1229 int sync_blocks = 0; 1230 sector_t s = r1_bio->sector; 1231 long sectors_to_go = r1_bio->sectors; 1232 /* make sure these bits doesn't get cleared. */ 1233 do { 1234 bitmap_end_sync(mddev->bitmap, s, 1235 &sync_blocks, 1); 1236 s += sync_blocks; 1237 sectors_to_go -= sync_blocks; 1238 } while (sectors_to_go > 0); 1239 md_error(mddev, conf->mirrors[mirror].rdev); 1240 } 1241 1242 update_head_pos(mirror, r1_bio); 1243 1244 if (atomic_dec_and_test(&r1_bio->remaining)) { 1245 sector_t s = r1_bio->sectors; 1246 put_buf(r1_bio); 1247 md_done_sync(mddev, s, uptodate); 1248 } 1249 } 1250 1251 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) 1252 { 1253 conf_t *conf = mddev->private; 1254 int i; 1255 int disks = conf->raid_disks; 1256 struct bio *bio, *wbio; 1257 1258 bio = r1_bio->bios[r1_bio->read_disk]; 1259 1260 1261 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1262 /* We have read all readable devices. If we haven't 1263 * got the block, then there is no hope left. 1264 * If we have, then we want to do a comparison 1265 * and skip the write if everything is the same. 1266 * If any blocks failed to read, then we need to 1267 * attempt an over-write 1268 */ 1269 int primary; 1270 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { 1271 for (i=0; i<mddev->raid_disks; i++) 1272 if (r1_bio->bios[i]->bi_end_io == end_sync_read) 1273 md_error(mddev, conf->mirrors[i].rdev); 1274 1275 md_done_sync(mddev, r1_bio->sectors, 1); 1276 put_buf(r1_bio); 1277 return; 1278 } 1279 for (primary=0; primary<mddev->raid_disks; primary++) 1280 if (r1_bio->bios[primary]->bi_end_io == end_sync_read && 1281 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { 1282 r1_bio->bios[primary]->bi_end_io = NULL; 1283 rdev_dec_pending(conf->mirrors[primary].rdev, mddev); 1284 break; 1285 } 1286 r1_bio->read_disk = primary; 1287 for (i=0; i<mddev->raid_disks; i++) 1288 if (r1_bio->bios[i]->bi_end_io == end_sync_read) { 1289 int j; 1290 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9); 1291 struct bio *pbio = r1_bio->bios[primary]; 1292 struct bio *sbio = r1_bio->bios[i]; 1293 1294 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { 1295 for (j = vcnt; j-- ; ) { 1296 struct page *p, *s; 1297 p = pbio->bi_io_vec[j].bv_page; 1298 s = sbio->bi_io_vec[j].bv_page; 1299 if (memcmp(page_address(p), 1300 page_address(s), 1301 PAGE_SIZE)) 1302 break; 1303 } 1304 } else 1305 j = 0; 1306 if (j >= 0) 1307 mddev->resync_mismatches += r1_bio->sectors; 1308 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) 1309 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { 1310 sbio->bi_end_io = NULL; 1311 rdev_dec_pending(conf->mirrors[i].rdev, mddev); 1312 } else { 1313 /* fixup the bio for reuse */ 1314 int size; 1315 sbio->bi_vcnt = vcnt; 1316 sbio->bi_size = r1_bio->sectors << 9; 1317 sbio->bi_idx = 0; 1318 sbio->bi_phys_segments = 0; 1319 sbio->bi_flags &= ~(BIO_POOL_MASK - 1); 1320 sbio->bi_flags |= 1 << BIO_UPTODATE; 1321 sbio->bi_next = NULL; 1322 sbio->bi_sector = r1_bio->sector + 1323 conf->mirrors[i].rdev->data_offset; 1324 sbio->bi_bdev = conf->mirrors[i].rdev->bdev; 1325 size = sbio->bi_size; 1326 for (j = 0; j < vcnt ; j++) { 1327 struct bio_vec *bi; 1328 bi = &sbio->bi_io_vec[j]; 1329 bi->bv_offset = 0; 1330 if (size > PAGE_SIZE) 1331 bi->bv_len = PAGE_SIZE; 1332 else 1333 bi->bv_len = size; 1334 size -= PAGE_SIZE; 1335 memcpy(page_address(bi->bv_page), 1336 page_address(pbio->bi_io_vec[j].bv_page), 1337 PAGE_SIZE); 1338 } 1339 1340 } 1341 } 1342 } 1343 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { 1344 /* ouch - failed to read all of that. 1345 * Try some synchronous reads of other devices to get 1346 * good data, much like with normal read errors. Only 1347 * read into the pages we already have so we don't 1348 * need to re-issue the read request. 1349 * We don't need to freeze the array, because being in an 1350 * active sync request, there is no normal IO, and 1351 * no overlapping syncs. 1352 */ 1353 sector_t sect = r1_bio->sector; 1354 int sectors = r1_bio->sectors; 1355 int idx = 0; 1356 1357 while(sectors) { 1358 int s = sectors; 1359 int d = r1_bio->read_disk; 1360 int success = 0; 1361 mdk_rdev_t *rdev; 1362 1363 if (s > (PAGE_SIZE>>9)) 1364 s = PAGE_SIZE >> 9; 1365 do { 1366 if (r1_bio->bios[d]->bi_end_io == end_sync_read) { 1367 /* No rcu protection needed here devices 1368 * can only be removed when no resync is 1369 * active, and resync is currently active 1370 */ 1371 rdev = conf->mirrors[d].rdev; 1372 if (sync_page_io(rdev->bdev, 1373 sect + rdev->data_offset, 1374 s<<9, 1375 bio->bi_io_vec[idx].bv_page, 1376 READ)) { 1377 success = 1; 1378 break; 1379 } 1380 } 1381 d++; 1382 if (d == conf->raid_disks) 1383 d = 0; 1384 } while (!success && d != r1_bio->read_disk); 1385 1386 if (success) { 1387 int start = d; 1388 /* write it back and re-read */ 1389 set_bit(R1BIO_Uptodate, &r1_bio->state); 1390 while (d != r1_bio->read_disk) { 1391 if (d == 0) 1392 d = conf->raid_disks; 1393 d--; 1394 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1395 continue; 1396 rdev = conf->mirrors[d].rdev; 1397 atomic_add(s, &rdev->corrected_errors); 1398 if (sync_page_io(rdev->bdev, 1399 sect + rdev->data_offset, 1400 s<<9, 1401 bio->bi_io_vec[idx].bv_page, 1402 WRITE) == 0) 1403 md_error(mddev, rdev); 1404 } 1405 d = start; 1406 while (d != r1_bio->read_disk) { 1407 if (d == 0) 1408 d = conf->raid_disks; 1409 d--; 1410 if (r1_bio->bios[d]->bi_end_io != end_sync_read) 1411 continue; 1412 rdev = conf->mirrors[d].rdev; 1413 if (sync_page_io(rdev->bdev, 1414 sect + rdev->data_offset, 1415 s<<9, 1416 bio->bi_io_vec[idx].bv_page, 1417 READ) == 0) 1418 md_error(mddev, rdev); 1419 } 1420 } else { 1421 char b[BDEVNAME_SIZE]; 1422 /* Cannot read from anywhere, array is toast */ 1423 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); 1424 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error" 1425 " for block %llu\n", 1426 bdevname(bio->bi_bdev,b), 1427 (unsigned long long)r1_bio->sector); 1428 md_done_sync(mddev, r1_bio->sectors, 0); 1429 put_buf(r1_bio); 1430 return; 1431 } 1432 sectors -= s; 1433 sect += s; 1434 idx ++; 1435 } 1436 } 1437 1438 /* 1439 * schedule writes 1440 */ 1441 atomic_set(&r1_bio->remaining, 1); 1442 for (i = 0; i < disks ; i++) { 1443 wbio = r1_bio->bios[i]; 1444 if (wbio->bi_end_io == NULL || 1445 (wbio->bi_end_io == end_sync_read && 1446 (i == r1_bio->read_disk || 1447 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) 1448 continue; 1449 1450 wbio->bi_rw = WRITE; 1451 wbio->bi_end_io = end_sync_write; 1452 atomic_inc(&r1_bio->remaining); 1453 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); 1454 1455 generic_make_request(wbio); 1456 } 1457 1458 if (atomic_dec_and_test(&r1_bio->remaining)) { 1459 /* if we're here, all write(s) have completed, so clean up */ 1460 md_done_sync(mddev, r1_bio->sectors, 1); 1461 put_buf(r1_bio); 1462 } 1463 } 1464 1465 /* 1466 * This is a kernel thread which: 1467 * 1468 * 1. Retries failed read operations on working mirrors. 1469 * 2. Updates the raid superblock when problems encounter. 1470 * 3. Performs writes following reads for array syncronising. 1471 */ 1472 1473 static void fix_read_error(conf_t *conf, int read_disk, 1474 sector_t sect, int sectors) 1475 { 1476 mddev_t *mddev = conf->mddev; 1477 while(sectors) { 1478 int s = sectors; 1479 int d = read_disk; 1480 int success = 0; 1481 int start; 1482 mdk_rdev_t *rdev; 1483 1484 if (s > (PAGE_SIZE>>9)) 1485 s = PAGE_SIZE >> 9; 1486 1487 do { 1488 /* Note: no rcu protection needed here 1489 * as this is synchronous in the raid1d thread 1490 * which is the thread that might remove 1491 * a device. If raid1d ever becomes multi-threaded.... 1492 */ 1493 rdev = conf->mirrors[d].rdev; 1494 if (rdev && 1495 test_bit(In_sync, &rdev->flags) && 1496 sync_page_io(rdev->bdev, 1497 sect + rdev->data_offset, 1498 s<<9, 1499 conf->tmppage, READ)) 1500 success = 1; 1501 else { 1502 d++; 1503 if (d == conf->raid_disks) 1504 d = 0; 1505 } 1506 } while (!success && d != read_disk); 1507 1508 if (!success) { 1509 /* Cannot read from anywhere -- bye bye array */ 1510 md_error(mddev, conf->mirrors[read_disk].rdev); 1511 break; 1512 } 1513 /* write it back and re-read */ 1514 start = d; 1515 while (d != read_disk) { 1516 if (d==0) 1517 d = conf->raid_disks; 1518 d--; 1519 rdev = conf->mirrors[d].rdev; 1520 if (rdev && 1521 test_bit(In_sync, &rdev->flags)) { 1522 if (sync_page_io(rdev->bdev, 1523 sect + rdev->data_offset, 1524 s<<9, conf->tmppage, WRITE) 1525 == 0) 1526 /* Well, this device is dead */ 1527 md_error(mddev, rdev); 1528 } 1529 } 1530 d = start; 1531 while (d != read_disk) { 1532 char b[BDEVNAME_SIZE]; 1533 if (d==0) 1534 d = conf->raid_disks; 1535 d--; 1536 rdev = conf->mirrors[d].rdev; 1537 if (rdev && 1538 test_bit(In_sync, &rdev->flags)) { 1539 if (sync_page_io(rdev->bdev, 1540 sect + rdev->data_offset, 1541 s<<9, conf->tmppage, READ) 1542 == 0) 1543 /* Well, this device is dead */ 1544 md_error(mddev, rdev); 1545 else { 1546 atomic_add(s, &rdev->corrected_errors); 1547 printk(KERN_INFO 1548 "raid1:%s: read error corrected " 1549 "(%d sectors at %llu on %s)\n", 1550 mdname(mddev), s, 1551 (unsigned long long)(sect + 1552 rdev->data_offset), 1553 bdevname(rdev->bdev, b)); 1554 } 1555 } 1556 } 1557 sectors -= s; 1558 sect += s; 1559 } 1560 } 1561 1562 static void raid1d(mddev_t *mddev) 1563 { 1564 r1bio_t *r1_bio; 1565 struct bio *bio; 1566 unsigned long flags; 1567 conf_t *conf = mddev->private; 1568 struct list_head *head = &conf->retry_list; 1569 int unplug=0; 1570 mdk_rdev_t *rdev; 1571 1572 md_check_recovery(mddev); 1573 1574 for (;;) { 1575 char b[BDEVNAME_SIZE]; 1576 1577 unplug += flush_pending_writes(conf); 1578 1579 spin_lock_irqsave(&conf->device_lock, flags); 1580 if (list_empty(head)) { 1581 spin_unlock_irqrestore(&conf->device_lock, flags); 1582 break; 1583 } 1584 r1_bio = list_entry(head->prev, r1bio_t, retry_list); 1585 list_del(head->prev); 1586 conf->nr_queued--; 1587 spin_unlock_irqrestore(&conf->device_lock, flags); 1588 1589 mddev = r1_bio->mddev; 1590 conf = mddev->private; 1591 if (test_bit(R1BIO_IsSync, &r1_bio->state)) { 1592 sync_request_write(mddev, r1_bio); 1593 unplug = 1; 1594 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) { 1595 /* some requests in the r1bio were BIO_RW_BARRIER 1596 * requests which failed with -EOPNOTSUPP. Hohumm.. 1597 * Better resubmit without the barrier. 1598 * We know which devices to resubmit for, because 1599 * all others have had their bios[] entry cleared. 1600 * We already have a nr_pending reference on these rdevs. 1601 */ 1602 int i; 1603 const int do_sync = bio_sync(r1_bio->master_bio); 1604 clear_bit(R1BIO_BarrierRetry, &r1_bio->state); 1605 clear_bit(R1BIO_Barrier, &r1_bio->state); 1606 for (i=0; i < conf->raid_disks; i++) 1607 if (r1_bio->bios[i]) 1608 atomic_inc(&r1_bio->remaining); 1609 for (i=0; i < conf->raid_disks; i++) 1610 if (r1_bio->bios[i]) { 1611 struct bio_vec *bvec; 1612 int j; 1613 1614 bio = bio_clone(r1_bio->master_bio, GFP_NOIO); 1615 /* copy pages from the failed bio, as 1616 * this might be a write-behind device */ 1617 __bio_for_each_segment(bvec, bio, j, 0) 1618 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page; 1619 bio_put(r1_bio->bios[i]); 1620 bio->bi_sector = r1_bio->sector + 1621 conf->mirrors[i].rdev->data_offset; 1622 bio->bi_bdev = conf->mirrors[i].rdev->bdev; 1623 bio->bi_end_io = raid1_end_write_request; 1624 bio->bi_rw = WRITE | do_sync; 1625 bio->bi_private = r1_bio; 1626 r1_bio->bios[i] = bio; 1627 generic_make_request(bio); 1628 } 1629 } else { 1630 int disk; 1631 1632 /* we got a read error. Maybe the drive is bad. Maybe just 1633 * the block and we can fix it. 1634 * We freeze all other IO, and try reading the block from 1635 * other devices. When we find one, we re-write 1636 * and check it that fixes the read error. 1637 * This is all done synchronously while the array is 1638 * frozen 1639 */ 1640 if (mddev->ro == 0) { 1641 freeze_array(conf); 1642 fix_read_error(conf, r1_bio->read_disk, 1643 r1_bio->sector, 1644 r1_bio->sectors); 1645 unfreeze_array(conf); 1646 } 1647 1648 bio = r1_bio->bios[r1_bio->read_disk]; 1649 if ((disk=read_balance(conf, r1_bio)) == -1 || 1650 disk == r1_bio->read_disk) { 1651 printk(KERN_ALERT "raid1: %s: unrecoverable I/O" 1652 " read error for block %llu\n", 1653 bdevname(bio->bi_bdev,b), 1654 (unsigned long long)r1_bio->sector); 1655 raid_end_bio_io(r1_bio); 1656 } else { 1657 const int do_sync = bio_sync(r1_bio->master_bio); 1658 r1_bio->bios[r1_bio->read_disk] = 1659 mddev->ro ? IO_BLOCKED : NULL; 1660 r1_bio->read_disk = disk; 1661 bio_put(bio); 1662 bio = bio_clone(r1_bio->master_bio, GFP_NOIO); 1663 r1_bio->bios[r1_bio->read_disk] = bio; 1664 rdev = conf->mirrors[disk].rdev; 1665 if (printk_ratelimit()) 1666 printk(KERN_ERR "raid1: %s: redirecting sector %llu to" 1667 " another mirror\n", 1668 bdevname(rdev->bdev,b), 1669 (unsigned long long)r1_bio->sector); 1670 bio->bi_sector = r1_bio->sector + rdev->data_offset; 1671 bio->bi_bdev = rdev->bdev; 1672 bio->bi_end_io = raid1_end_read_request; 1673 bio->bi_rw = READ | do_sync; 1674 bio->bi_private = r1_bio; 1675 unplug = 1; 1676 generic_make_request(bio); 1677 } 1678 } 1679 } 1680 if (unplug) 1681 unplug_slaves(mddev); 1682 } 1683 1684 1685 static int init_resync(conf_t *conf) 1686 { 1687 int buffs; 1688 1689 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; 1690 BUG_ON(conf->r1buf_pool); 1691 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, 1692 conf->poolinfo); 1693 if (!conf->r1buf_pool) 1694 return -ENOMEM; 1695 conf->next_resync = 0; 1696 return 0; 1697 } 1698 1699 /* 1700 * perform a "sync" on one "block" 1701 * 1702 * We need to make sure that no normal I/O request - particularly write 1703 * requests - conflict with active sync requests. 1704 * 1705 * This is achieved by tracking pending requests and a 'barrier' concept 1706 * that can be installed to exclude normal IO requests. 1707 */ 1708 1709 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) 1710 { 1711 conf_t *conf = mddev->private; 1712 r1bio_t *r1_bio; 1713 struct bio *bio; 1714 sector_t max_sector, nr_sectors; 1715 int disk = -1; 1716 int i; 1717 int wonly = -1; 1718 int write_targets = 0, read_targets = 0; 1719 int sync_blocks; 1720 int still_degraded = 0; 1721 1722 if (!conf->r1buf_pool) 1723 { 1724 /* 1725 printk("sync start - bitmap %p\n", mddev->bitmap); 1726 */ 1727 if (init_resync(conf)) 1728 return 0; 1729 } 1730 1731 max_sector = mddev->dev_sectors; 1732 if (sector_nr >= max_sector) { 1733 /* If we aborted, we need to abort the 1734 * sync on the 'current' bitmap chunk (there will 1735 * only be one in raid1 resync. 1736 * We can find the current addess in mddev->curr_resync 1737 */ 1738 if (mddev->curr_resync < max_sector) /* aborted */ 1739 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 1740 &sync_blocks, 1); 1741 else /* completed sync */ 1742 conf->fullsync = 0; 1743 1744 bitmap_close_sync(mddev->bitmap); 1745 close_sync(conf); 1746 return 0; 1747 } 1748 1749 if (mddev->bitmap == NULL && 1750 mddev->recovery_cp == MaxSector && 1751 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && 1752 conf->fullsync == 0) { 1753 *skipped = 1; 1754 return max_sector - sector_nr; 1755 } 1756 /* before building a request, check if we can skip these blocks.. 1757 * This call the bitmap_start_sync doesn't actually record anything 1758 */ 1759 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && 1760 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1761 /* We can skip this block, and probably several more */ 1762 *skipped = 1; 1763 return sync_blocks; 1764 } 1765 /* 1766 * If there is non-resync activity waiting for a turn, 1767 * and resync is going fast enough, 1768 * then let it though before starting on this new sync request. 1769 */ 1770 if (!go_faster && conf->nr_waiting) 1771 msleep_interruptible(1000); 1772 1773 bitmap_cond_end_sync(mddev->bitmap, sector_nr); 1774 raise_barrier(conf); 1775 1776 conf->next_resync = sector_nr; 1777 1778 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); 1779 rcu_read_lock(); 1780 /* 1781 * If we get a correctably read error during resync or recovery, 1782 * we might want to read from a different device. So we 1783 * flag all drives that could conceivably be read from for READ, 1784 * and any others (which will be non-In_sync devices) for WRITE. 1785 * If a read fails, we try reading from something else for which READ 1786 * is OK. 1787 */ 1788 1789 r1_bio->mddev = mddev; 1790 r1_bio->sector = sector_nr; 1791 r1_bio->state = 0; 1792 set_bit(R1BIO_IsSync, &r1_bio->state); 1793 1794 for (i=0; i < conf->raid_disks; i++) { 1795 mdk_rdev_t *rdev; 1796 bio = r1_bio->bios[i]; 1797 1798 /* take from bio_init */ 1799 bio->bi_next = NULL; 1800 bio->bi_flags |= 1 << BIO_UPTODATE; 1801 bio->bi_rw = READ; 1802 bio->bi_vcnt = 0; 1803 bio->bi_idx = 0; 1804 bio->bi_phys_segments = 0; 1805 bio->bi_size = 0; 1806 bio->bi_end_io = NULL; 1807 bio->bi_private = NULL; 1808 1809 rdev = rcu_dereference(conf->mirrors[i].rdev); 1810 if (rdev == NULL || 1811 test_bit(Faulty, &rdev->flags)) { 1812 still_degraded = 1; 1813 continue; 1814 } else if (!test_bit(In_sync, &rdev->flags)) { 1815 bio->bi_rw = WRITE; 1816 bio->bi_end_io = end_sync_write; 1817 write_targets ++; 1818 } else { 1819 /* may need to read from here */ 1820 bio->bi_rw = READ; 1821 bio->bi_end_io = end_sync_read; 1822 if (test_bit(WriteMostly, &rdev->flags)) { 1823 if (wonly < 0) 1824 wonly = i; 1825 } else { 1826 if (disk < 0) 1827 disk = i; 1828 } 1829 read_targets++; 1830 } 1831 atomic_inc(&rdev->nr_pending); 1832 bio->bi_sector = sector_nr + rdev->data_offset; 1833 bio->bi_bdev = rdev->bdev; 1834 bio->bi_private = r1_bio; 1835 } 1836 rcu_read_unlock(); 1837 if (disk < 0) 1838 disk = wonly; 1839 r1_bio->read_disk = disk; 1840 1841 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) 1842 /* extra read targets are also write targets */ 1843 write_targets += read_targets-1; 1844 1845 if (write_targets == 0 || read_targets == 0) { 1846 /* There is nowhere to write, so all non-sync 1847 * drives must be failed - so we are finished 1848 */ 1849 sector_t rv = max_sector - sector_nr; 1850 *skipped = 1; 1851 put_buf(r1_bio); 1852 return rv; 1853 } 1854 1855 if (max_sector > mddev->resync_max) 1856 max_sector = mddev->resync_max; /* Don't do IO beyond here */ 1857 nr_sectors = 0; 1858 sync_blocks = 0; 1859 do { 1860 struct page *page; 1861 int len = PAGE_SIZE; 1862 if (sector_nr + (len>>9) > max_sector) 1863 len = (max_sector - sector_nr) << 9; 1864 if (len == 0) 1865 break; 1866 if (sync_blocks == 0) { 1867 if (!bitmap_start_sync(mddev->bitmap, sector_nr, 1868 &sync_blocks, still_degraded) && 1869 !conf->fullsync && 1870 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) 1871 break; 1872 BUG_ON(sync_blocks < (PAGE_SIZE>>9)); 1873 if (len > (sync_blocks<<9)) 1874 len = sync_blocks<<9; 1875 } 1876 1877 for (i=0 ; i < conf->raid_disks; i++) { 1878 bio = r1_bio->bios[i]; 1879 if (bio->bi_end_io) { 1880 page = bio->bi_io_vec[bio->bi_vcnt].bv_page; 1881 if (bio_add_page(bio, page, len, 0) == 0) { 1882 /* stop here */ 1883 bio->bi_io_vec[bio->bi_vcnt].bv_page = page; 1884 while (i > 0) { 1885 i--; 1886 bio = r1_bio->bios[i]; 1887 if (bio->bi_end_io==NULL) 1888 continue; 1889 /* remove last page from this bio */ 1890 bio->bi_vcnt--; 1891 bio->bi_size -= len; 1892 bio->bi_flags &= ~(1<< BIO_SEG_VALID); 1893 } 1894 goto bio_full; 1895 } 1896 } 1897 } 1898 nr_sectors += len>>9; 1899 sector_nr += len>>9; 1900 sync_blocks -= (len>>9); 1901 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); 1902 bio_full: 1903 r1_bio->sectors = nr_sectors; 1904 1905 /* For a user-requested sync, we read all readable devices and do a 1906 * compare 1907 */ 1908 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { 1909 atomic_set(&r1_bio->remaining, read_targets); 1910 for (i=0; i<conf->raid_disks; i++) { 1911 bio = r1_bio->bios[i]; 1912 if (bio->bi_end_io == end_sync_read) { 1913 md_sync_acct(bio->bi_bdev, nr_sectors); 1914 generic_make_request(bio); 1915 } 1916 } 1917 } else { 1918 atomic_set(&r1_bio->remaining, 1); 1919 bio = r1_bio->bios[r1_bio->read_disk]; 1920 md_sync_acct(bio->bi_bdev, nr_sectors); 1921 generic_make_request(bio); 1922 1923 } 1924 return nr_sectors; 1925 } 1926 1927 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks) 1928 { 1929 if (sectors) 1930 return sectors; 1931 1932 return mddev->dev_sectors; 1933 } 1934 1935 static int run(mddev_t *mddev) 1936 { 1937 conf_t *conf; 1938 int i, j, disk_idx; 1939 mirror_info_t *disk; 1940 mdk_rdev_t *rdev; 1941 1942 if (mddev->level != 1) { 1943 printk("raid1: %s: raid level not set to mirroring (%d)\n", 1944 mdname(mddev), mddev->level); 1945 goto out; 1946 } 1947 if (mddev->reshape_position != MaxSector) { 1948 printk("raid1: %s: reshape_position set but not supported\n", 1949 mdname(mddev)); 1950 goto out; 1951 } 1952 /* 1953 * copy the already verified devices into our private RAID1 1954 * bookkeeping area. [whatever we allocate in run(), 1955 * should be freed in stop()] 1956 */ 1957 conf = kzalloc(sizeof(conf_t), GFP_KERNEL); 1958 mddev->private = conf; 1959 if (!conf) 1960 goto out_no_mem; 1961 1962 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, 1963 GFP_KERNEL); 1964 if (!conf->mirrors) 1965 goto out_no_mem; 1966 1967 conf->tmppage = alloc_page(GFP_KERNEL); 1968 if (!conf->tmppage) 1969 goto out_no_mem; 1970 1971 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL); 1972 if (!conf->poolinfo) 1973 goto out_no_mem; 1974 conf->poolinfo->mddev = mddev; 1975 conf->poolinfo->raid_disks = mddev->raid_disks; 1976 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 1977 r1bio_pool_free, 1978 conf->poolinfo); 1979 if (!conf->r1bio_pool) 1980 goto out_no_mem; 1981 1982 spin_lock_init(&conf->device_lock); 1983 mddev->queue->queue_lock = &conf->device_lock; 1984 1985 list_for_each_entry(rdev, &mddev->disks, same_set) { 1986 disk_idx = rdev->raid_disk; 1987 if (disk_idx >= mddev->raid_disks 1988 || disk_idx < 0) 1989 continue; 1990 disk = conf->mirrors + disk_idx; 1991 1992 disk->rdev = rdev; 1993 disk_stack_limits(mddev->gendisk, rdev->bdev, 1994 rdev->data_offset << 9); 1995 /* as we don't honour merge_bvec_fn, we must never risk 1996 * violating it, so limit ->max_sector to one PAGE, as 1997 * a one page request is never in violation. 1998 */ 1999 if (rdev->bdev->bd_disk->queue->merge_bvec_fn && 2000 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) 2001 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); 2002 2003 disk->head_position = 0; 2004 } 2005 conf->raid_disks = mddev->raid_disks; 2006 conf->mddev = mddev; 2007 INIT_LIST_HEAD(&conf->retry_list); 2008 2009 spin_lock_init(&conf->resync_lock); 2010 init_waitqueue_head(&conf->wait_barrier); 2011 2012 bio_list_init(&conf->pending_bio_list); 2013 bio_list_init(&conf->flushing_bio_list); 2014 2015 2016 mddev->degraded = 0; 2017 for (i = 0; i < conf->raid_disks; i++) { 2018 2019 disk = conf->mirrors + i; 2020 2021 if (!disk->rdev || 2022 !test_bit(In_sync, &disk->rdev->flags)) { 2023 disk->head_position = 0; 2024 mddev->degraded++; 2025 if (disk->rdev) 2026 conf->fullsync = 1; 2027 } 2028 } 2029 if (mddev->degraded == conf->raid_disks) { 2030 printk(KERN_ERR "raid1: no operational mirrors for %s\n", 2031 mdname(mddev)); 2032 goto out_free_conf; 2033 } 2034 if (conf->raid_disks - mddev->degraded == 1) 2035 mddev->recovery_cp = MaxSector; 2036 2037 /* 2038 * find the first working one and use it as a starting point 2039 * to read balancing. 2040 */ 2041 for (j = 0; j < conf->raid_disks && 2042 (!conf->mirrors[j].rdev || 2043 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++) 2044 /* nothing */; 2045 conf->last_used = j; 2046 2047 2048 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1"); 2049 if (!mddev->thread) { 2050 printk(KERN_ERR 2051 "raid1: couldn't allocate thread for %s\n", 2052 mdname(mddev)); 2053 goto out_free_conf; 2054 } 2055 2056 if (mddev->recovery_cp != MaxSector) 2057 printk(KERN_NOTICE "raid1: %s is not clean" 2058 " -- starting background reconstruction\n", 2059 mdname(mddev)); 2060 printk(KERN_INFO 2061 "raid1: raid set %s active with %d out of %d mirrors\n", 2062 mdname(mddev), mddev->raid_disks - mddev->degraded, 2063 mddev->raid_disks); 2064 /* 2065 * Ok, everything is just fine now 2066 */ 2067 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); 2068 2069 mddev->queue->unplug_fn = raid1_unplug; 2070 mddev->queue->backing_dev_info.congested_fn = raid1_congested; 2071 mddev->queue->backing_dev_info.congested_data = mddev; 2072 md_integrity_register(mddev); 2073 return 0; 2074 2075 out_no_mem: 2076 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n", 2077 mdname(mddev)); 2078 2079 out_free_conf: 2080 if (conf) { 2081 if (conf->r1bio_pool) 2082 mempool_destroy(conf->r1bio_pool); 2083 kfree(conf->mirrors); 2084 safe_put_page(conf->tmppage); 2085 kfree(conf->poolinfo); 2086 kfree(conf); 2087 mddev->private = NULL; 2088 } 2089 out: 2090 return -EIO; 2091 } 2092 2093 static int stop(mddev_t *mddev) 2094 { 2095 conf_t *conf = mddev->private; 2096 struct bitmap *bitmap = mddev->bitmap; 2097 int behind_wait = 0; 2098 2099 /* wait for behind writes to complete */ 2100 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) { 2101 behind_wait++; 2102 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait); 2103 set_current_state(TASK_UNINTERRUPTIBLE); 2104 schedule_timeout(HZ); /* wait a second */ 2105 /* need to kick something here to make sure I/O goes? */ 2106 } 2107 2108 raise_barrier(conf); 2109 lower_barrier(conf); 2110 2111 md_unregister_thread(mddev->thread); 2112 mddev->thread = NULL; 2113 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 2114 if (conf->r1bio_pool) 2115 mempool_destroy(conf->r1bio_pool); 2116 kfree(conf->mirrors); 2117 kfree(conf->poolinfo); 2118 kfree(conf); 2119 mddev->private = NULL; 2120 return 0; 2121 } 2122 2123 static int raid1_resize(mddev_t *mddev, sector_t sectors) 2124 { 2125 /* no resync is happening, and there is enough space 2126 * on all devices, so we can resize. 2127 * We need to make sure resync covers any new space. 2128 * If the array is shrinking we should possibly wait until 2129 * any io in the removed space completes, but it hardly seems 2130 * worth it. 2131 */ 2132 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0)); 2133 if (mddev->array_sectors > raid1_size(mddev, sectors, 0)) 2134 return -EINVAL; 2135 set_capacity(mddev->gendisk, mddev->array_sectors); 2136 mddev->changed = 1; 2137 revalidate_disk(mddev->gendisk); 2138 if (sectors > mddev->dev_sectors && 2139 mddev->recovery_cp == MaxSector) { 2140 mddev->recovery_cp = mddev->dev_sectors; 2141 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 2142 } 2143 mddev->dev_sectors = sectors; 2144 mddev->resync_max_sectors = sectors; 2145 return 0; 2146 } 2147 2148 static int raid1_reshape(mddev_t *mddev) 2149 { 2150 /* We need to: 2151 * 1/ resize the r1bio_pool 2152 * 2/ resize conf->mirrors 2153 * 2154 * We allocate a new r1bio_pool if we can. 2155 * Then raise a device barrier and wait until all IO stops. 2156 * Then resize conf->mirrors and swap in the new r1bio pool. 2157 * 2158 * At the same time, we "pack" the devices so that all the missing 2159 * devices have the higher raid_disk numbers. 2160 */ 2161 mempool_t *newpool, *oldpool; 2162 struct pool_info *newpoolinfo; 2163 mirror_info_t *newmirrors; 2164 conf_t *conf = mddev->private; 2165 int cnt, raid_disks; 2166 unsigned long flags; 2167 int d, d2, err; 2168 2169 /* Cannot change chunk_size, layout, or level */ 2170 if (mddev->chunk_sectors != mddev->new_chunk_sectors || 2171 mddev->layout != mddev->new_layout || 2172 mddev->level != mddev->new_level) { 2173 mddev->new_chunk_sectors = mddev->chunk_sectors; 2174 mddev->new_layout = mddev->layout; 2175 mddev->new_level = mddev->level; 2176 return -EINVAL; 2177 } 2178 2179 err = md_allow_write(mddev); 2180 if (err) 2181 return err; 2182 2183 raid_disks = mddev->raid_disks + mddev->delta_disks; 2184 2185 if (raid_disks < conf->raid_disks) { 2186 cnt=0; 2187 for (d= 0; d < conf->raid_disks; d++) 2188 if (conf->mirrors[d].rdev) 2189 cnt++; 2190 if (cnt > raid_disks) 2191 return -EBUSY; 2192 } 2193 2194 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); 2195 if (!newpoolinfo) 2196 return -ENOMEM; 2197 newpoolinfo->mddev = mddev; 2198 newpoolinfo->raid_disks = raid_disks; 2199 2200 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, 2201 r1bio_pool_free, newpoolinfo); 2202 if (!newpool) { 2203 kfree(newpoolinfo); 2204 return -ENOMEM; 2205 } 2206 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL); 2207 if (!newmirrors) { 2208 kfree(newpoolinfo); 2209 mempool_destroy(newpool); 2210 return -ENOMEM; 2211 } 2212 2213 raise_barrier(conf); 2214 2215 /* ok, everything is stopped */ 2216 oldpool = conf->r1bio_pool; 2217 conf->r1bio_pool = newpool; 2218 2219 for (d = d2 = 0; d < conf->raid_disks; d++) { 2220 mdk_rdev_t *rdev = conf->mirrors[d].rdev; 2221 if (rdev && rdev->raid_disk != d2) { 2222 char nm[20]; 2223 sprintf(nm, "rd%d", rdev->raid_disk); 2224 sysfs_remove_link(&mddev->kobj, nm); 2225 rdev->raid_disk = d2; 2226 sprintf(nm, "rd%d", rdev->raid_disk); 2227 sysfs_remove_link(&mddev->kobj, nm); 2228 if (sysfs_create_link(&mddev->kobj, 2229 &rdev->kobj, nm)) 2230 printk(KERN_WARNING 2231 "md/raid1: cannot register " 2232 "%s for %s\n", 2233 nm, mdname(mddev)); 2234 } 2235 if (rdev) 2236 newmirrors[d2++].rdev = rdev; 2237 } 2238 kfree(conf->mirrors); 2239 conf->mirrors = newmirrors; 2240 kfree(conf->poolinfo); 2241 conf->poolinfo = newpoolinfo; 2242 2243 spin_lock_irqsave(&conf->device_lock, flags); 2244 mddev->degraded += (raid_disks - conf->raid_disks); 2245 spin_unlock_irqrestore(&conf->device_lock, flags); 2246 conf->raid_disks = mddev->raid_disks = raid_disks; 2247 mddev->delta_disks = 0; 2248 2249 conf->last_used = 0; /* just make sure it is in-range */ 2250 lower_barrier(conf); 2251 2252 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 2253 md_wakeup_thread(mddev->thread); 2254 2255 mempool_destroy(oldpool); 2256 return 0; 2257 } 2258 2259 static void raid1_quiesce(mddev_t *mddev, int state) 2260 { 2261 conf_t *conf = mddev->private; 2262 2263 switch(state) { 2264 case 1: 2265 raise_barrier(conf); 2266 break; 2267 case 0: 2268 lower_barrier(conf); 2269 break; 2270 } 2271 } 2272 2273 2274 static struct mdk_personality raid1_personality = 2275 { 2276 .name = "raid1", 2277 .level = 1, 2278 .owner = THIS_MODULE, 2279 .make_request = make_request, 2280 .run = run, 2281 .stop = stop, 2282 .status = status, 2283 .error_handler = error, 2284 .hot_add_disk = raid1_add_disk, 2285 .hot_remove_disk= raid1_remove_disk, 2286 .spare_active = raid1_spare_active, 2287 .sync_request = sync_request, 2288 .resize = raid1_resize, 2289 .size = raid1_size, 2290 .check_reshape = raid1_reshape, 2291 .quiesce = raid1_quiesce, 2292 }; 2293 2294 static int __init raid_init(void) 2295 { 2296 return register_md_personality(&raid1_personality); 2297 } 2298 2299 static void raid_exit(void) 2300 { 2301 unregister_md_personality(&raid1_personality); 2302 } 2303 2304 module_init(raid_init); 2305 module_exit(raid_exit); 2306 MODULE_LICENSE("GPL"); 2307 MODULE_ALIAS("md-personality-3"); /* RAID1 */ 2308 MODULE_ALIAS("md-raid1"); 2309 MODULE_ALIAS("md-level-1"); 2310