drivers/md/raid1.c

   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  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2, or (at your option)
  18  * any later version.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * (for example /usr/src/linux/COPYING); if not, write to the Free
  22  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/raid/raid1.h>
  26
  27 /*
  28  * Number of guaranteed r1bios in case of extreme VM load:
  29  */
  30 #define NR_RAID1_BIOS 256
  31
  32 static mdk_personality_t raid1_personality;
  33
  34 static void unplug_slaves(mddev_t *mddev);
  35
  36
  37 static void * r1bio_pool_alloc(unsigned int __nocast gfp_flags, void *data)
  38 {
  39         struct pool_info *pi = data;
  40         r1bio_t *r1_bio;
  41         int size = offsetof(r1bio_t, bios[pi->raid_disks]);
  42
  43         /* allocate a r1bio with room for raid_disks entries in the bios array */
  44         r1_bio = kmalloc(size, gfp_flags);
  45         if (r1_bio)
  46                 memset(r1_bio, 0, size);
  47         else
  48                 unplug_slaves(pi->mddev);
  49
  50         return r1_bio;
  51 }
  52
  53 static void r1bio_pool_free(void *r1_bio, void *data)
  54 {
  55         kfree(r1_bio);
  56 }
  57
  58 #define RESYNC_BLOCK_SIZE (64*1024)
  59 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
  60 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
  61 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
  62 #define RESYNC_WINDOW (2048*1024)
  63
  64 static void * r1buf_pool_alloc(unsigned int __nocast gfp_flags, void *data)
  65 {
  66         struct pool_info *pi = data;
  67         struct page *page;
  68         r1bio_t *r1_bio;
  69         struct bio *bio;
  70         int i, j;
  71
  72         r1_bio = r1bio_pool_alloc(gfp_flags, pi);
  73         if (!r1_bio) {
  74                 unplug_slaves(pi->mddev);
  75                 return NULL;
  76         }
  77
  78         /*
  79          * Allocate bios : 1 for reading, n-1 for writing
  80          */
  81         for (j = pi->raid_disks ; j-- ; ) {
  82                 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
  83                 if (!bio)
  84                         goto out_free_bio;
  85                 r1_bio->bios[j] = bio;
  86         }
  87         /*
  88          * Allocate RESYNC_PAGES data pages and attach them to
  89          * the first bio;
  90          */
  91         bio = r1_bio->bios[0];
  92         for (i = 0; i < RESYNC_PAGES; i++) {
  93                 page = alloc_page(gfp_flags);
  94                 if (unlikely(!page))
  95                         goto out_free_pages;
  96
  97                 bio->bi_io_vec[i].bv_page = page;
  98         }
  99
 100         r1_bio->master_bio = NULL;
 101
 102         return r1_bio;
 103
 104 out_free_pages:
 105         for ( ; i > 0 ; i--)
 106                 __free_page(bio->bi_io_vec[i-1].bv_page);
 107 out_free_bio:
 108         while ( ++j < pi->raid_disks )
 109                 bio_put(r1_bio->bios[j]);
 110         r1bio_pool_free(r1_bio, data);
 111         return NULL;
 112 }
 113
 114 static void r1buf_pool_free(void *__r1_bio, void *data)
 115 {
 116         struct pool_info *pi = data;
 117         int i;
 118         r1bio_t *r1bio = __r1_bio;
 119         struct bio *bio = r1bio->bios[0];
 120
 121         for (i = 0; i < RESYNC_PAGES; i++) {
 122                 __free_page(bio->bi_io_vec[i].bv_page);
 123                 bio->bi_io_vec[i].bv_page = NULL;
 124         }
 125         for (i=0 ; i < pi->raid_disks; i++)
 126                 bio_put(r1bio->bios[i]);
 127
 128         r1bio_pool_free(r1bio, data);
 129 }
 130
 131 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
 132 {
 133         int i;
 134
 135         for (i = 0; i < conf->raid_disks; i++) {
 136                 struct bio **bio = r1_bio->bios + i;
 137                 if (*bio)
 138                         bio_put(*bio);
 139                 *bio = NULL;
 140         }
 141 }
 142
 143 static inline void free_r1bio(r1bio_t *r1_bio)
 144 {
 145         unsigned long flags;
 146
 147         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 148
 149         /*
 150          * Wake up any possible resync thread that waits for the device
 151          * to go idle.
 152          */
 153         spin_lock_irqsave(&conf->resync_lock, flags);
 154         if (!--conf->nr_pending) {
 155                 wake_up(&conf->wait_idle);
 156                 wake_up(&conf->wait_resume);
 157         }
 158         spin_unlock_irqrestore(&conf->resync_lock, flags);
 159
 160         put_all_bios(conf, r1_bio);
 161         mempool_free(r1_bio, conf->r1bio_pool);
 162 }
 163
 164 static inline void put_buf(r1bio_t *r1_bio)
 165 {
 166         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 167         unsigned long flags;
 168
 169         mempool_free(r1_bio, conf->r1buf_pool);
 170
 171         spin_lock_irqsave(&conf->resync_lock, flags);
 172         if (!conf->barrier)
 173                 BUG();
 174         --conf->barrier;
 175         wake_up(&conf->wait_resume);
 176         wake_up(&conf->wait_idle);
 177
 178         if (!--conf->nr_pending) {
 179                 wake_up(&conf->wait_idle);
 180                 wake_up(&conf->wait_resume);
 181         }
 182         spin_unlock_irqrestore(&conf->resync_lock, flags);
 183 }
 184
 185 static void reschedule_retry(r1bio_t *r1_bio)
 186 {
 187         unsigned long flags;
 188         mddev_t *mddev = r1_bio->mddev;
 189         conf_t *conf = mddev_to_conf(mddev);
 190
 191         spin_lock_irqsave(&conf->device_lock, flags);
 192         list_add(&r1_bio->retry_list, &conf->retry_list);
 193         spin_unlock_irqrestore(&conf->device_lock, flags);
 194
 195         md_wakeup_thread(mddev->thread);
 196 }
 197
 198 /*
 199  * raid_end_bio_io() is called when we have finished servicing a mirrored
 200  * operation and are ready to return a success/failure code to the buffer
 201  * cache layer.
 202  */
 203 static void raid_end_bio_io(r1bio_t *r1_bio)
 204 {
 205         struct bio *bio = r1_bio->master_bio;
 206
 207         bio_endio(bio, bio->bi_size,
 208                 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
 209         free_r1bio(r1_bio);
 210 }
 211
 212 /*
 213  * Update disk head position estimator based on IRQ completion info.
 214  */
 215 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
 216 {
 217         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 218
 219         conf->mirrors[disk].head_position =
 220                 r1_bio->sector + (r1_bio->sectors);
 221 }
 222
 223 static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
 224 {
 225         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 226         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
 227         int mirror;
 228         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 229
 230         if (bio->bi_size)
 231                 return 1;
 232
 233         mirror = r1_bio->read_disk;
 234         /*
 235          * this branch is our 'one mirror IO has finished' event handler:
 236          */
 237         if (!uptodate)
 238                 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
 239         else
 240                 /*
 241                  * Set R1BIO_Uptodate in our master bio, so that
 242                  * we will return a good error code for to the higher
 243                  * levels even if IO on some other mirrored buffer fails.
 244                  *
 245                  * The 'master' represents the composite IO operation to
 246                  * user-side. So if something waits for IO, then it will
 247                  * wait for the 'master' bio.
 248                  */
 249                 set_bit(R1BIO_Uptodate, &r1_bio->state);
 250
 251         update_head_pos(mirror, r1_bio);
 252
 253         /*
 254          * we have only one bio on the read side
 255          */
 256         if (uptodate)
 257                 raid_end_bio_io(r1_bio);
 258         else {
 259                 /*
 260                  * oops, read error:
 261                  */
 262                 char b[BDEVNAME_SIZE];
 263                 if (printk_ratelimit())
 264                         printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
 265                                bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
 266                 reschedule_retry(r1_bio);
 267         }
 268
 269         rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
 270         return 0;
 271 }
 272
 273 static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
 274 {
 275         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 276         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
 277         int mirror;
 278         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 279
 280         if (bio->bi_size)
 281                 return 1;
 282
 283         for (mirror = 0; mirror < conf->raid_disks; mirror++)
 284                 if (r1_bio->bios[mirror] == bio)
 285                         break;
 286
 287         /*
 288          * this branch is our 'one mirror IO has finished' event handler:
 289          */
 290         if (!uptodate)
 291                 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
 292         else
 293                 /*
 294                  * Set R1BIO_Uptodate in our master bio, so that
 295                  * we will return a good error code for to the higher
 296                  * levels even if IO on some other mirrored buffer fails.
 297                  *
 298                  * The 'master' represents the composite IO operation to
 299                  * user-side. So if something waits for IO, then it will
 300                  * wait for the 'master' bio.
 301                  */
 302                 set_bit(R1BIO_Uptodate, &r1_bio->state);
 303
 304         update_head_pos(mirror, r1_bio);
 305
 306         /*
 307          *
 308          * Let's see if all mirrored write operations have finished
 309          * already.
 310          */
 311         if (atomic_dec_and_test(&r1_bio->remaining)) {
 312                 md_write_end(r1_bio->mddev);
 313                 raid_end_bio_io(r1_bio);
 314         }
 315
 316         rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
 317         return 0;
 318 }
 319
 320
 321 /*
 322  * This routine returns the disk from which the requested read should
 323  * be done. There is a per-array 'next expected sequential IO' sector
 324  * number - if this matches on the next IO then we use the last disk.
 325  * There is also a per-disk 'last know head position' sector that is
 326  * maintained from IRQ contexts, both the normal and the resync IO
 327  * completion handlers update this position correctly. If there is no
 328  * perfect sequential match then we pick the disk whose head is closest.
 329  *
 330  * If there are 2 mirrors in the same 2 devices, performance degrades
 331  * because position is mirror, not device based.
 332  *
 333  * The rdev for the device selected will have nr_pending incremented.
 334  */
 335 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
 336 {
 337         const unsigned long this_sector = r1_bio->sector;
 338         int new_disk = conf->last_used, disk = new_disk;
 339         const int sectors = r1_bio->sectors;
 340         sector_t new_distance, current_distance;
 341         mdk_rdev_t *new_rdev, *rdev;
 342
 343         rcu_read_lock();
 344         /*
 345          * Check if it if we can balance. We can balance on the whole
 346          * device if no resync is going on, or below the resync window.
 347          * We take the first readable disk when above the resync window.
 348          */
 349  retry:
 350         if (conf->mddev->recovery_cp < MaxSector &&
 351             (this_sector + sectors >= conf->next_resync)) {
 352                 /* Choose the first operation device, for consistancy */
 353                 new_disk = 0;
 354
 355                 while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL ||
 356                        !new_rdev->in_sync) {
 357                         new_disk++;
 358                         if (new_disk == conf->raid_disks) {
 359                                 new_disk = -1;
 360                                 break;
 361                         }
 362                 }
 363                 goto rb_out;
 364         }
 365
 366
 367         /* make sure the disk is operational */
 368         while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL ||
 369                !new_rdev->in_sync) {
 370                 if (new_disk <= 0)
 371                         new_disk = conf->raid_disks;
 372                 new_disk--;
 373                 if (new_disk == disk) {
 374                         new_disk = -1;
 375                         goto rb_out;
 376                 }
 377         }
 378         disk = new_disk;
 379         /* now disk == new_disk == starting point for search */
 380
 381         /*
 382          * Don't change to another disk for sequential reads:
 383          */
 384         if (conf->next_seq_sect == this_sector)
 385                 goto rb_out;
 386         if (this_sector == conf->mirrors[new_disk].head_position)
 387                 goto rb_out;
 388
 389         current_distance = abs(this_sector - conf->mirrors[disk].head_position);
 390
 391         /* Find the disk whose head is closest */
 392
 393         do {
 394                 if (disk <= 0)
 395                         disk = conf->raid_disks;
 396                 disk--;
 397
 398                 if ((rdev=conf->mirrors[disk].rdev) == NULL ||
 399                     !rdev->in_sync)
 400                         continue;
 401
 402                 if (!atomic_read(&rdev->nr_pending)) {
 403                         new_disk = disk;
 404                         new_rdev = rdev;
 405                         break;
 406                 }
 407                 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
 408                 if (new_distance < current_distance) {
 409                         current_distance = new_distance;
 410                         new_disk = disk;
 411                         new_rdev = rdev;
 412                 }
 413         } while (disk != conf->last_used);
 414
 415 rb_out:
 416
 417
 418         if (new_disk >= 0) {
 419                 conf->next_seq_sect = this_sector + sectors;
 420                 conf->last_used = new_disk;
 421                 atomic_inc(&new_rdev->nr_pending);
 422                 if (!new_rdev->in_sync) {
 423                         /* cannot risk returning a device that failed
 424                          * before we inc'ed nr_pending
 425                          */
 426                         atomic_dec(&new_rdev->nr_pending);
 427                         goto retry;
 428                 }
 429         }
 430         rcu_read_unlock();
 431
 432         return new_disk;
 433 }
 434
 435 static void unplug_slaves(mddev_t *mddev)
 436 {
 437         conf_t *conf = mddev_to_conf(mddev);
 438         int i;
 439
 440         rcu_read_lock();
 441         for (i=0; i<mddev->raid_disks; i++) {
 442                 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
 443                 if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) {
 444                         request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
 445
 446                         atomic_inc(&rdev->nr_pending);
 447                         rcu_read_unlock();
 448
 449                         if (r_queue->unplug_fn)
 450                                 r_queue->unplug_fn(r_queue);
 451
 452                         rdev_dec_pending(rdev, mddev);
 453                         rcu_read_lock();
 454                 }
 455         }
 456         rcu_read_unlock();
 457 }
 458
 459 static void raid1_unplug(request_queue_t *q)
 460 {
 461         unplug_slaves(q->queuedata);
 462 }
 463
 464 static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
 465                              sector_t *error_sector)
 466 {
 467         mddev_t *mddev = q->queuedata;
 468         conf_t *conf = mddev_to_conf(mddev);
 469         int i, ret = 0;
 470
 471         rcu_read_lock();
 472         for (i=0; i<mddev->raid_disks && ret == 0; i++) {
 473                 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
 474                 if (rdev && !rdev->faulty) {
 475                         struct block_device *bdev = rdev->bdev;
 476                         request_queue_t *r_queue = bdev_get_queue(bdev);
 477
 478                         if (!r_queue->issue_flush_fn)
 479                                 ret = -EOPNOTSUPP;
 480                         else {
 481                                 atomic_inc(&rdev->nr_pending);
 482                                 rcu_read_unlock();
 483                                 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
 484                                                               error_sector);
 485                                 rdev_dec_pending(rdev, mddev);
 486                                 rcu_read_lock();
 487                         }
 488                 }
 489         }
 490         rcu_read_unlock();
 491         return ret;
 492 }
 493
 494 /*
 495  * Throttle resync depth, so that we can both get proper overlapping of
 496  * requests, but are still able to handle normal requests quickly.
 497  */
 498 #define RESYNC_DEPTH 32
 499
 500 static void device_barrier(conf_t *conf, sector_t sect)
 501 {
 502         spin_lock_irq(&conf->resync_lock);
 503         wait_event_lock_irq(conf->wait_idle, !waitqueue_active(&conf->wait_resume),
 504                             conf->resync_lock, unplug_slaves(conf->mddev));
 505
 506         if (!conf->barrier++) {
 507                 wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
 508                                     conf->resync_lock, unplug_slaves(conf->mddev));
 509                 if (conf->nr_pending)
 510                         BUG();
 511         }
 512         wait_event_lock_irq(conf->wait_resume, conf->barrier < RESYNC_DEPTH,
 513                             conf->resync_lock, unplug_slaves(conf->mddev));
 514         conf->next_resync = sect;
 515         spin_unlock_irq(&conf->resync_lock);
 516 }
 517
 518 static int make_request(request_queue_t *q, struct bio * bio)
 519 {
 520         mddev_t *mddev = q->queuedata;
 521         conf_t *conf = mddev_to_conf(mddev);
 522         mirror_info_t *mirror;
 523         r1bio_t *r1_bio;
 524         struct bio *read_bio;
 525         int i, disks;
 526         mdk_rdev_t *rdev;
 527
 528         /*
 529          * Register the new request and wait if the reconstruction
 530          * thread has put up a bar for new requests.
 531          * Continue immediately if no resync is active currently.
 532          */
 533         spin_lock_irq(&conf->resync_lock);
 534         wait_event_lock_irq(conf->wait_resume, !conf->barrier, conf->resync_lock, );
 535         conf->nr_pending++;
 536         spin_unlock_irq(&conf->resync_lock);
 537
 538         if (bio_data_dir(bio)==WRITE) {
 539                 disk_stat_inc(mddev->gendisk, writes);
 540                 disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio));
 541         } else {
 542                 disk_stat_inc(mddev->gendisk, reads);
 543                 disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio));
 544         }
 545
 546         /*
 547          * make_request() can abort the operation when READA is being
 548          * used and no empty request is available.
 549          *
 550          */
 551         r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
 552
 553         r1_bio->master_bio = bio;
 554         r1_bio->sectors = bio->bi_size >> 9;
 555
 556         r1_bio->mddev = mddev;
 557         r1_bio->sector = bio->bi_sector;
 558
 559         r1_bio->state = 0;
 560
 561         if (bio_data_dir(bio) == READ) {
 562                 /*
 563                  * read balancing logic:
 564                  */
 565                 int rdisk = read_balance(conf, r1_bio);
 566
 567                 if (rdisk < 0) {
 568                         /* couldn't find anywhere to read from */
 569                         raid_end_bio_io(r1_bio);
 570                         return 0;
 571                 }
 572                 mirror = conf->mirrors + rdisk;
 573
 574                 r1_bio->read_disk = rdisk;
 575
 576                 read_bio = bio_clone(bio, GFP_NOIO);
 577
 578                 r1_bio->bios[rdisk] = read_bio;
 579
 580                 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
 581                 read_bio->bi_bdev = mirror->rdev->bdev;
 582                 read_bio->bi_end_io = raid1_end_read_request;
 583                 read_bio->bi_rw = READ;
 584                 read_bio->bi_private = r1_bio;
 585
 586                 generic_make_request(read_bio);
 587                 return 0;
 588         }
 589
 590         /*
 591          * WRITE:
 592          */
 593         /* first select target devices under spinlock and
 594          * inc refcount on their rdev.  Record them by setting
 595          * bios[x] to bio
 596          */
 597         disks = conf->raid_disks;
 598         rcu_read_lock();
 599         for (i = 0;  i < disks; i++) {
 600                 if ((rdev=conf->mirrors[i].rdev) != NULL &&
 601                     !rdev->faulty) {
 602                         atomic_inc(&rdev->nr_pending);
 603                         if (rdev->faulty) {
 604                                 atomic_dec(&rdev->nr_pending);
 605                                 r1_bio->bios[i] = NULL;
 606                         } else
 607                                 r1_bio->bios[i] = bio;
 608                 } else
 609                         r1_bio->bios[i] = NULL;
 610         }
 611         rcu_read_unlock();
 612
 613         atomic_set(&r1_bio->remaining, 1);
 614         md_write_start(mddev);
 615         for (i = 0; i < disks; i++) {
 616                 struct bio *mbio;
 617                 if (!r1_bio->bios[i])
 618                         continue;
 619
 620                 mbio = bio_clone(bio, GFP_NOIO);
 621                 r1_bio->bios[i] = mbio;
 622
 623                 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
 624                 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
 625                 mbio->bi_end_io = raid1_end_write_request;
 626                 mbio->bi_rw = WRITE;
 627                 mbio->bi_private = r1_bio;
 628
 629                 atomic_inc(&r1_bio->remaining);
 630                 generic_make_request(mbio);
 631         }
 632
 633         if (atomic_dec_and_test(&r1_bio->remaining)) {
 634                 md_write_end(mddev);
 635                 raid_end_bio_io(r1_bio);
 636         }
 637
 638         return 0;
 639 }
 640
 641 static void status(struct seq_file *seq, mddev_t *mddev)
 642 {
 643         conf_t *conf = mddev_to_conf(mddev);
 644         int i;
 645
 646         seq_printf(seq, " [%d/%d] [", conf->raid_disks,
 647                                                 conf->working_disks);
 648         for (i = 0; i < conf->raid_disks; i++)
 649                 seq_printf(seq, "%s",
 650                               conf->mirrors[i].rdev &&
 651                               conf->mirrors[i].rdev->in_sync ? "U" : "_");
 652         seq_printf(seq, "]");
 653 }
 654
 655
 656 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
 657 {
 658         char b[BDEVNAME_SIZE];
 659         conf_t *conf = mddev_to_conf(mddev);
 660
 661         /*
 662          * If it is not operational, then we have already marked it as dead
 663          * else if it is the last working disks, ignore the error, let the
 664          * next level up know.
 665          * else mark the drive as failed
 666          */
 667         if (rdev->in_sync
 668             && conf->working_disks == 1)
 669                 /*
 670                  * Don't fail the drive, act as though we were just a
 671                  * normal single drive
 672                  */
 673                 return;
 674         if (rdev->in_sync) {
 675                 mddev->degraded++;
 676                 conf->working_disks--;
 677                 /*
 678                  * if recovery is running, make sure it aborts.
 679                  */
 680                 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
 681         }
 682         rdev->in_sync = 0;
 683         rdev->faulty = 1;
 684         mddev->sb_dirty = 1;
 685         printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
 686                 "       Operation continuing on %d devices\n",
 687                 bdevname(rdev->bdev,b), conf->working_disks);
 688 }
 689
 690 static void print_conf(conf_t *conf)
 691 {
 692         int i;
 693         mirror_info_t *tmp;
 694
 695         printk("RAID1 conf printout:\n");
 696         if (!conf) {
 697                 printk("(!conf)\n");
 698                 return;
 699         }
 700         printk(" --- wd:%d rd:%d\n", conf->working_disks,
 701                 conf->raid_disks);
 702
 703         for (i = 0; i < conf->raid_disks; i++) {
 704                 char b[BDEVNAME_SIZE];
 705                 tmp = conf->mirrors + i;
 706                 if (tmp->rdev)
 707                         printk(" disk %d, wo:%d, o:%d, dev:%s\n",
 708                                 i, !tmp->rdev->in_sync, !tmp->rdev->faulty,
 709                                 bdevname(tmp->rdev->bdev,b));
 710         }
 711 }
 712
 713 static void close_sync(conf_t *conf)
 714 {
 715         spin_lock_irq(&conf->resync_lock);
 716         wait_event_lock_irq(conf->wait_resume, !conf->barrier,
 717                             conf->resync_lock,  unplug_slaves(conf->mddev));
 718         spin_unlock_irq(&conf->resync_lock);
 719
 720         if (conf->barrier) BUG();
 721         if (waitqueue_active(&conf->wait_idle)) BUG();
 722
 723         mempool_destroy(conf->r1buf_pool);
 724         conf->r1buf_pool = NULL;
 725 }
 726
 727 static int raid1_spare_active(mddev_t *mddev)
 728 {
 729         int i;
 730         conf_t *conf = mddev->private;
 731         mirror_info_t *tmp;
 732
 733         /*
 734          * Find all failed disks within the RAID1 configuration
 735          * and mark them readable
 736          */
 737         for (i = 0; i < conf->raid_disks; i++) {
 738                 tmp = conf->mirrors + i;
 739                 if (tmp->rdev
 740                     && !tmp->rdev->faulty
 741                     && !tmp->rdev->in_sync) {
 742                         conf->working_disks++;
 743                         mddev->degraded--;
 744                         tmp->rdev->in_sync = 1;
 745                 }
 746         }
 747
 748         print_conf(conf);
 749         return 0;
 750 }
 751
 752
 753 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 754 {
 755         conf_t *conf = mddev->private;
 756         int found = 0;
 757         int mirror;
 758         mirror_info_t *p;
 759
 760         for (mirror=0; mirror < mddev->raid_disks; mirror++)
 761                 if ( !(p=conf->mirrors+mirror)->rdev) {
 762
 763                         blk_queue_stack_limits(mddev->queue,
 764                                                rdev->bdev->bd_disk->queue);
 765                         /* as we don't honour merge_bvec_fn, we must never risk
 766                          * violating it, so limit ->max_sector to one PAGE, as
 767                          * a one page request is never in violation.
 768                          */
 769                         if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
 770                             mddev->queue->max_sectors > (PAGE_SIZE>>9))
 771                                 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
 772
 773                         p->head_position = 0;
 774                         rdev->raid_disk = mirror;
 775                         found = 1;
 776                         p->rdev = rdev;
 777                         break;
 778                 }
 779
 780         print_conf(conf);
 781         return found;
 782 }
 783
 784 static int raid1_remove_disk(mddev_t *mddev, int number)
 785 {
 786         conf_t *conf = mddev->private;
 787         int err = 0;
 788         mdk_rdev_t *rdev;
 789         mirror_info_t *p = conf->mirrors+ number;
 790
 791         print_conf(conf);
 792         rdev = p->rdev;
 793         if (rdev) {
 794                 if (rdev->in_sync ||
 795                     atomic_read(&rdev->nr_pending)) {
 796                         err = -EBUSY;
 797                         goto abort;
 798                 }
 799                 p->rdev = NULL;
 800                 synchronize_kernel();
 801                 if (atomic_read(&rdev->nr_pending)) {
 802                         /* lost the race, try later */
 803                         err = -EBUSY;
 804                         p->rdev = rdev;
 805                 }
 806         }
 807 abort:
 808
 809         print_conf(conf);
 810         return err;
 811 }
 812
 813
 814 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
 815 {
 816         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 817         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
 818         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 819
 820         if (bio->bi_size)
 821                 return 1;
 822
 823         if (r1_bio->bios[r1_bio->read_disk] != bio)
 824                 BUG();
 825         update_head_pos(r1_bio->read_disk, r1_bio);
 826         /*
 827          * we have read a block, now it needs to be re-written,
 828          * or re-read if the read failed.
 829          * We don't do much here, just schedule handling by raid1d
 830          */
 831         if (!uptodate)
 832                 md_error(r1_bio->mddev,
 833                          conf->mirrors[r1_bio->read_disk].rdev);
 834         else
 835                 set_bit(R1BIO_Uptodate, &r1_bio->state);
 836         rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
 837         reschedule_retry(r1_bio);
 838         return 0;
 839 }
 840
 841 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
 842 {
 843         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 844         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
 845         mddev_t *mddev = r1_bio->mddev;
 846         conf_t *conf = mddev_to_conf(mddev);
 847         int i;
 848         int mirror=0;
 849
 850         if (bio->bi_size)
 851                 return 1;
 852
 853         for (i = 0; i < conf->raid_disks; i++)
 854                 if (r1_bio->bios[i] == bio) {
 855                         mirror = i;
 856                         break;
 857                 }
 858         if (!uptodate)
 859                 md_error(mddev, conf->mirrors[mirror].rdev);
 860         update_head_pos(mirror, r1_bio);
 861
 862         if (atomic_dec_and_test(&r1_bio->remaining)) {
 863                 md_done_sync(mddev, r1_bio->sectors, uptodate);
 864                 put_buf(r1_bio);
 865         }
 866         rdev_dec_pending(conf->mirrors[mirror].rdev, mddev);
 867         return 0;
 868 }
 869
 870 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
 871 {
 872         conf_t *conf = mddev_to_conf(mddev);
 873         int i;
 874         int disks = conf->raid_disks;
 875         struct bio *bio, *wbio;
 876
 877         bio = r1_bio->bios[r1_bio->read_disk];
 878
 879         /*
 880          * schedule writes
 881          */
 882         if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
 883                 /*
 884                  * There is no point trying a read-for-reconstruct as
 885                  * reconstruct is about to be aborted
 886                  */
 887                 char b[BDEVNAME_SIZE];
 888                 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
 889                         " for block %llu\n",
 890                         bdevname(bio->bi_bdev,b),
 891                         (unsigned long long)r1_bio->sector);
 892                 md_done_sync(mddev, r1_bio->sectors, 0);
 893                 put_buf(r1_bio);
 894                 return;
 895         }
 896
 897         atomic_set(&r1_bio->remaining, 1);
 898         for (i = 0; i < disks ; i++) {
 899                 wbio = r1_bio->bios[i];
 900                 if (wbio->bi_end_io != end_sync_write)
 901                         continue;
 902
 903                 atomic_inc(&conf->mirrors[i].rdev->nr_pending);
 904                 atomic_inc(&r1_bio->remaining);
 905                 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
 906                 generic_make_request(wbio);
 907         }
 908
 909         if (atomic_dec_and_test(&r1_bio->remaining)) {
 910                 md_done_sync(mddev, r1_bio->sectors, 1);
 911                 put_buf(r1_bio);
 912         }
 913 }
 914
 915 /*
 916  * This is a kernel thread which:
 917  *
 918  *      1.      Retries failed read operations on working mirrors.
 919  *      2.      Updates the raid superblock when problems encounter.
 920  *      3.      Performs writes following reads for array syncronising.
 921  */
 922
 923 static void raid1d(mddev_t *mddev)
 924 {
 925         r1bio_t *r1_bio;
 926         struct bio *bio;
 927         unsigned long flags;
 928         conf_t *conf = mddev_to_conf(mddev);
 929         struct list_head *head = &conf->retry_list;
 930         int unplug=0;
 931         mdk_rdev_t *rdev;
 932
 933         md_check_recovery(mddev);
 934         md_handle_safemode(mddev);
 935
 936         for (;;) {
 937                 char b[BDEVNAME_SIZE];
 938                 spin_lock_irqsave(&conf->device_lock, flags);
 939                 if (list_empty(head))
 940                         break;
 941                 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
 942                 list_del(head->prev);
 943                 spin_unlock_irqrestore(&conf->device_lock, flags);
 944
 945                 mddev = r1_bio->mddev;
 946                 conf = mddev_to_conf(mddev);
 947                 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
 948                         sync_request_write(mddev, r1_bio);
 949                         unplug = 1;
 950                 } else {
 951                         int disk;
 952                         bio = r1_bio->bios[r1_bio->read_disk];
 953                         if ((disk=read_balance(conf, r1_bio)) == -1) {
 954                                 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
 955                                        " read error for block %llu\n",
 956                                        bdevname(bio->bi_bdev,b),
 957                                        (unsigned long long)r1_bio->sector);
 958                                 raid_end_bio_io(r1_bio);
 959                         } else {
 960                                 r1_bio->bios[r1_bio->read_disk] = NULL;
 961                                 r1_bio->read_disk = disk;
 962                                 bio_put(bio);
 963                                 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
 964                                 r1_bio->bios[r1_bio->read_disk] = bio;
 965                                 rdev = conf->mirrors[disk].rdev;
 966                                 if (printk_ratelimit())
 967                                         printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
 968                                                " another mirror\n",
 969                                                bdevname(rdev->bdev,b),
 970                                                (unsigned long long)r1_bio->sector);
 971                                 bio->bi_sector = r1_bio->sector + rdev->data_offset;
 972                                 bio->bi_bdev = rdev->bdev;
 973                                 bio->bi_end_io = raid1_end_read_request;
 974                                 bio->bi_rw = READ;
 975                                 bio->bi_private = r1_bio;
 976                                 unplug = 1;
 977                                 generic_make_request(bio);
 978                         }
 979                 }
 980         }
 981         spin_unlock_irqrestore(&conf->device_lock, flags);
 982         if (unplug)
 983                 unplug_slaves(mddev);
 984 }
 985
 986
 987 static int init_resync(conf_t *conf)
 988 {
 989         int buffs;
 990
 991         buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
 992         if (conf->r1buf_pool)
 993                 BUG();
 994         conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
 995                                           conf->poolinfo);
 996         if (!conf->r1buf_pool)
 997                 return -ENOMEM;
 998         conf->next_resync = 0;
 999         return 0;
1000 }
1001
1002 /*
1003  * perform a "sync" on one "block"
1004  *
1005  * We need to make sure that no normal I/O request - particularly write
1006  * requests - conflict with active sync requests.
1007  *
1008  * This is achieved by tracking pending requests and a 'barrier' concept
1009  * that can be installed to exclude normal IO requests.
1010  */
1011
1012 static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
1013 {
1014         conf_t *conf = mddev_to_conf(mddev);
1015         mirror_info_t *mirror;
1016         r1bio_t *r1_bio;
1017         struct bio *bio;
1018         sector_t max_sector, nr_sectors;
1019         int disk;
1020         int i;
1021         int write_targets = 0;
1022
1023         if (!conf->r1buf_pool)
1024                 if (init_resync(conf))
1025                         return -ENOMEM;
1026
1027         max_sector = mddev->size << 1;
1028         if (sector_nr >= max_sector) {
1029                 close_sync(conf);
1030                 return 0;
1031         }
1032
1033         /*
1034          * If there is non-resync activity waiting for us then
1035          * put in a delay to throttle resync.
1036          */
1037         if (!go_faster && waitqueue_active(&conf->wait_resume))
1038                 msleep_interruptible(1000);
1039         device_barrier(conf, sector_nr + RESYNC_SECTORS);
1040
1041         /*
1042          * If reconstructing, and >1 working disc,
1043          * could dedicate one to rebuild and others to
1044          * service read requests ..
1045          */
1046         disk = conf->last_used;
1047         /* make sure disk is operational */
1048
1049         while (conf->mirrors[disk].rdev == NULL ||
1050                !conf->mirrors[disk].rdev->in_sync) {
1051                 if (disk <= 0)
1052                         disk = conf->raid_disks;
1053                 disk--;
1054                 if (disk == conf->last_used)
1055                         break;
1056         }
1057         conf->last_used = disk;
1058         atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
1059
1060
1061         mirror = conf->mirrors + disk;
1062
1063         r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1064
1065         spin_lock_irq(&conf->resync_lock);
1066         conf->nr_pending++;
1067         spin_unlock_irq(&conf->resync_lock);
1068
1069         r1_bio->mddev = mddev;
1070         r1_bio->sector = sector_nr;
1071         set_bit(R1BIO_IsSync, &r1_bio->state);
1072         r1_bio->read_disk = disk;
1073
1074         for (i=0; i < conf->raid_disks; i++) {
1075                 bio = r1_bio->bios[i];
1076
1077                 /* take from bio_init */
1078                 bio->bi_next = NULL;
1079                 bio->bi_flags |= 1 << BIO_UPTODATE;
1080                 bio->bi_rw = 0;
1081                 bio->bi_vcnt = 0;
1082                 bio->bi_idx = 0;
1083                 bio->bi_phys_segments = 0;
1084                 bio->bi_hw_segments = 0;
1085                 bio->bi_size = 0;
1086                 bio->bi_end_io = NULL;
1087                 bio->bi_private = NULL;
1088
1089                 if (i == disk) {
1090                         bio->bi_rw = READ;
1091                         bio->bi_end_io = end_sync_read;
1092                 } else if (conf->mirrors[i].rdev &&
1093                            !conf->mirrors[i].rdev->faulty &&
1094                            (!conf->mirrors[i].rdev->in_sync ||
1095                             sector_nr + RESYNC_SECTORS > mddev->recovery_cp)) {
1096                         bio->bi_rw = WRITE;
1097                         bio->bi_end_io = end_sync_write;
1098                         write_targets ++;
1099                 } else
1100                         continue;
1101                 bio->bi_sector = sector_nr + conf->mirrors[i].rdev->data_offset;
1102                 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1103                 bio->bi_private = r1_bio;
1104         }
1105         if (write_targets == 0) {
1106                 /* There is nowhere to write, so all non-sync
1107                  * drives must be failed - so we are finished
1108                  */
1109                 int rv = max_sector - sector_nr;
1110                 md_done_sync(mddev, rv, 1);
1111                 put_buf(r1_bio);
1112                 rdev_dec_pending(conf->mirrors[disk].rdev, mddev);
1113                 return rv;
1114         }
1115
1116         nr_sectors = 0;
1117         do {
1118                 struct page *page;
1119                 int len = PAGE_SIZE;
1120                 if (sector_nr + (len>>9) > max_sector)
1121                         len = (max_sector - sector_nr) << 9;
1122                 if (len == 0)
1123                         break;
1124                 for (i=0 ; i < conf->raid_disks; i++) {
1125                         bio = r1_bio->bios[i];
1126                         if (bio->bi_end_io) {
1127                                 page = r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page;
1128                                 if (bio_add_page(bio, page, len, 0) == 0) {
1129                                         /* stop here */
1130                                         r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page = page;
1131                                         while (i > 0) {
1132                                                 i--;
1133                                                 bio = r1_bio->bios[i];
1134                                                 if (bio->bi_end_io==NULL) continue;
1135                                                 /* remove last page from this bio */
1136                                                 bio->bi_vcnt--;
1137                                                 bio->bi_size -= len;
1138                                                 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1139                                         }
1140                                         goto bio_full;
1141                                 }
1142                         }
1143                 }
1144                 nr_sectors += len>>9;
1145                 sector_nr += len>>9;
1146         } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1147  bio_full:
1148         bio = r1_bio->bios[disk];
1149         r1_bio->sectors = nr_sectors;
1150
1151         md_sync_acct(mirror->rdev->bdev, nr_sectors);
1152
1153         generic_make_request(bio);
1154
1155         return nr_sectors;
1156 }
1157
1158 static int run(mddev_t *mddev)
1159 {
1160         conf_t *conf;
1161         int i, j, disk_idx;
1162         mirror_info_t *disk;
1163         mdk_rdev_t *rdev;
1164         struct list_head *tmp;
1165
1166         if (mddev->level != 1) {
1167                 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1168                        mdname(mddev), mddev->level);
1169                 goto out;
1170         }
1171         /*
1172          * copy the already verified devices into our private RAID1
1173          * bookkeeping area. [whatever we allocate in run(),
1174          * should be freed in stop()]
1175          */
1176         conf = kmalloc(sizeof(conf_t), GFP_KERNEL);
1177         mddev->private = conf;
1178         if (!conf)
1179                 goto out_no_mem;
1180
1181         memset(conf, 0, sizeof(*conf));
1182         conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1183                                  GFP_KERNEL);
1184         if (!conf->mirrors)
1185                 goto out_no_mem;
1186
1187         memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks);
1188
1189         conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1190         if (!conf->poolinfo)
1191                 goto out_no_mem;
1192         conf->poolinfo->mddev = mddev;
1193         conf->poolinfo->raid_disks = mddev->raid_disks;
1194         conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1195                                           r1bio_pool_free,
1196                                           conf->poolinfo);
1197         if (!conf->r1bio_pool)
1198                 goto out_no_mem;
1199
1200         mddev->queue->unplug_fn = raid1_unplug;
1201
1202         mddev->queue->issue_flush_fn = raid1_issue_flush;
1203
1204         ITERATE_RDEV(mddev, rdev, tmp) {
1205                 disk_idx = rdev->raid_disk;
1206                 if (disk_idx >= mddev->raid_disks
1207                     || disk_idx < 0)
1208                         continue;
1209                 disk = conf->mirrors + disk_idx;
1210
1211                 disk->rdev = rdev;
1212
1213                 blk_queue_stack_limits(mddev->queue,
1214                                        rdev->bdev->bd_disk->queue);
1215                 /* as we don't honour merge_bvec_fn, we must never risk
1216                  * violating it, so limit ->max_sector to one PAGE, as
1217                  * a one page request is never in violation.
1218                  */
1219                 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1220                     mddev->queue->max_sectors > (PAGE_SIZE>>9))
1221                         blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1222
1223                 disk->head_position = 0;
1224                 if (!rdev->faulty && rdev->in_sync)
1225                         conf->working_disks++;
1226         }
1227         conf->raid_disks = mddev->raid_disks;
1228         conf->mddev = mddev;
1229         spin_lock_init(&conf->device_lock);
1230         INIT_LIST_HEAD(&conf->retry_list);
1231         if (conf->working_disks == 1)
1232                 mddev->recovery_cp = MaxSector;
1233
1234         spin_lock_init(&conf->resync_lock);
1235         init_waitqueue_head(&conf->wait_idle);
1236         init_waitqueue_head(&conf->wait_resume);
1237
1238         if (!conf->working_disks) {
1239                 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1240                         mdname(mddev));
1241                 goto out_free_conf;
1242         }
1243
1244         mddev->degraded = 0;
1245         for (i = 0; i < conf->raid_disks; i++) {
1246
1247                 disk = conf->mirrors + i;
1248
1249                 if (!disk->rdev) {
1250                         disk->head_position = 0;
1251                         mddev->degraded++;
1252                 }
1253         }
1254
1255         /*
1256          * find the first working one and use it as a starting point
1257          * to read balancing.
1258          */
1259         for (j = 0; j < conf->raid_disks &&
1260                      (!conf->mirrors[j].rdev ||
1261                       !conf->mirrors[j].rdev->in_sync) ; j++)
1262                 /* nothing */;
1263         conf->last_used = j;
1264
1265
1266
1267         {
1268                 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1269                 if (!mddev->thread) {
1270                         printk(KERN_ERR
1271                                 "raid1: couldn't allocate thread for %s\n",
1272                                 mdname(mddev));
1273                         goto out_free_conf;
1274                 }
1275         }
1276         printk(KERN_INFO
1277                 "raid1: raid set %s active with %d out of %d mirrors\n",
1278                 mdname(mddev), mddev->raid_disks - mddev->degraded,
1279                 mddev->raid_disks);
1280         /*
1281          * Ok, everything is just fine now
1282          */
1283         mddev->array_size = mddev->size;
1284
1285         return 0;
1286
1287 out_no_mem:
1288         printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1289                mdname(mddev));
1290
1291 out_free_conf:
1292         if (conf) {
1293                 if (conf->r1bio_pool)
1294                         mempool_destroy(conf->r1bio_pool);
1295                 if (conf->mirrors)
1296                         kfree(conf->mirrors);
1297                 if (conf->poolinfo)
1298                         kfree(conf->poolinfo);
1299                 kfree(conf);
1300                 mddev->private = NULL;
1301         }
1302 out:
1303         return -EIO;
1304 }
1305
1306 static int stop(mddev_t *mddev)
1307 {
1308         conf_t *conf = mddev_to_conf(mddev);
1309
1310         md_unregister_thread(mddev->thread);
1311         mddev->thread = NULL;
1312         blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1313         if (conf->r1bio_pool)
1314                 mempool_destroy(conf->r1bio_pool);
1315         if (conf->mirrors)
1316                 kfree(conf->mirrors);
1317         if (conf->poolinfo)
1318                 kfree(conf->poolinfo);
1319         kfree(conf);
1320         mddev->private = NULL;
1321         return 0;
1322 }
1323
1324 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1325 {
1326         /* no resync is happening, and there is enough space
1327          * on all devices, so we can resize.
1328          * We need to make sure resync covers any new space.
1329          * If the array is shrinking we should possibly wait until
1330          * any io in the removed space completes, but it hardly seems
1331          * worth it.
1332          */
1333         mddev->array_size = sectors>>1;
1334         set_capacity(mddev->gendisk, mddev->array_size << 1);
1335         mddev->changed = 1;
1336         if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1337                 mddev->recovery_cp = mddev->size << 1;
1338                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1339         }
1340         mddev->size = mddev->array_size;
1341         return 0;
1342 }
1343
1344 static int raid1_reshape(mddev_t *mddev, int raid_disks)
1345 {
1346         /* We need to:
1347          * 1/ resize the r1bio_pool
1348          * 2/ resize conf->mirrors
1349          *
1350          * We allocate a new r1bio_pool if we can.
1351          * Then raise a device barrier and wait until all IO stops.
1352          * Then resize conf->mirrors and swap in the new r1bio pool.
1353          */
1354         mempool_t *newpool, *oldpool;
1355         struct pool_info *newpoolinfo;
1356         mirror_info_t *newmirrors;
1357         conf_t *conf = mddev_to_conf(mddev);
1358
1359         int d;
1360
1361         for (d= raid_disks; d < conf->raid_disks; d++)
1362                 if (conf->mirrors[d].rdev)
1363                         return -EBUSY;
1364
1365         newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
1366         if (!newpoolinfo)
1367                 return -ENOMEM;
1368         newpoolinfo->mddev = mddev;
1369         newpoolinfo->raid_disks = raid_disks;
1370
1371         newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1372                                  r1bio_pool_free, newpoolinfo);
1373         if (!newpool) {
1374                 kfree(newpoolinfo);
1375                 return -ENOMEM;
1376         }
1377         newmirrors = kmalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
1378         if (!newmirrors) {
1379                 kfree(newpoolinfo);
1380                 mempool_destroy(newpool);
1381                 return -ENOMEM;
1382         }
1383         memset(newmirrors, 0, sizeof(struct mirror_info)*raid_disks);
1384
1385         spin_lock_irq(&conf->resync_lock);
1386         conf->barrier++;
1387         wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
1388                             conf->resync_lock, unplug_slaves(mddev));
1389         spin_unlock_irq(&conf->resync_lock);
1390
1391         /* ok, everything is stopped */
1392         oldpool = conf->r1bio_pool;
1393         conf->r1bio_pool = newpool;
1394         for (d=0; d < raid_disks && d < conf->raid_disks; d++)
1395                 newmirrors[d] = conf->mirrors[d];
1396         kfree(conf->mirrors);
1397         conf->mirrors = newmirrors;
1398         kfree(conf->poolinfo);
1399         conf->poolinfo = newpoolinfo;
1400
1401         mddev->degraded += (raid_disks - conf->raid_disks);
1402         conf->raid_disks = mddev->raid_disks = raid_disks;
1403
1404         spin_lock_irq(&conf->resync_lock);
1405         conf->barrier--;
1406         spin_unlock_irq(&conf->resync_lock);
1407         wake_up(&conf->wait_resume);
1408         wake_up(&conf->wait_idle);
1409
1410
1411         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1412         md_wakeup_thread(mddev->thread);
1413
1414         mempool_destroy(oldpool);
1415         return 0;
1416 }
1417
1418
1419 static mdk_personality_t raid1_personality =
1420 {
1421         .name           = "raid1",
1422         .owner          = THIS_MODULE,
1423         .make_request   = make_request,
1424         .run            = run,
1425         .stop           = stop,
1426         .status         = status,
1427         .error_handler  = error,
1428         .hot_add_disk   = raid1_add_disk,
1429         .hot_remove_disk= raid1_remove_disk,
1430         .spare_active   = raid1_spare_active,
1431         .sync_request   = sync_request,
1432         .resize         = raid1_resize,
1433         .reshape        = raid1_reshape,
1434 };
1435
1436 static int __init raid_init(void)
1437 {
1438         return register_md_personality(RAID1, &raid1_personality);
1439 }
1440
1441 static void raid_exit(void)
1442 {
1443         unregister_md_personality(RAID1);
1444 }
1445
1446 module_init(raid_init);
1447 module_exit(raid_exit);
1448 MODULE_LICENSE("GPL");
1449 MODULE_ALIAS("md-personality-3"); /* RAID1 */