drivers/md/md.c

   1 /*
   2    md.c : Multiple Devices driver for Linux
   3           Copyright (C) 1998, 1999, 2000 Ingo Molnar
   4
   5      completely rewritten, based on the MD driver code from Marc Zyngier
   6
   7    Changes:
   8
   9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
  10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
  11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
  12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
  13    - kmod support by: Cyrus Durgin
  14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
  15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
  16
  17    - lots of fixes and improvements to the RAID1/RAID5 and generic
  18      RAID code (such as request based resynchronization):
  19
  20      Neil Brown <neilb@cse.unsw.edu.au>.
  21
  22    - persistent bitmap code
  23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
  24
  25    This program is free software; you can redistribute it and/or modify
  26    it under the terms of the GNU General Public License as published by
  27    the Free Software Foundation; either version 2, or (at your option)
  28    any later version.
  29
  30    You should have received a copy of the GNU General Public License
  31    (for example /usr/src/linux/COPYING); if not, write to the Free
  32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  33 */
  34
  35 #include <linux/module.h>
  36 #include <linux/config.h>
  37 #include <linux/kthread.h>
  38 #include <linux/linkage.h>
  39 #include <linux/raid/md.h>
  40 #include <linux/raid/bitmap.h>
  41 #include <linux/sysctl.h>
  42 #include <linux/devfs_fs_kernel.h>
  43 #include <linux/buffer_head.h> /* for invalidate_bdev */
  44 #include <linux/suspend.h>
  45
  46 #include <linux/init.h>
  47
  48 #include <linux/file.h>
  49
  50 #ifdef CONFIG_KMOD
  51 #include <linux/kmod.h>
  52 #endif
  53
  54 #include <asm/unaligned.h>
  55
  56 #define MAJOR_NR MD_MAJOR
  57 #define MD_DRIVER
  58
  59 /* 63 partitions with the alternate major number (mdp) */
  60 #define MdpMinorShift 6
  61
  62 #define DEBUG 0
  63 #define dprintk(x...) ((void)(DEBUG && printk(x)))
  64
  65
  66 #ifndef MODULE
  67 static void autostart_arrays (int part);
  68 #endif
  69
  70 static mdk_personality_t *pers[MAX_PERSONALITY];
  71 static DEFINE_SPINLOCK(pers_lock);
  72
  73 /*
  74  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
  75  * is 1000 KB/sec, so the extra system load does not show up that much.
  76  * Increase it if you want to have more _guaranteed_ speed. Note that
  77  * the RAID driver will use the maximum available bandwidth if the IO
  78  * subsystem is idle. There is also an 'absolute maximum' reconstruction
  79  * speed limit - in case reconstruction slows down your system despite
  80  * idle IO detection.
  81  *
  82  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
  83  */
  84
  85 static int sysctl_speed_limit_min = 1000;
  86 static int sysctl_speed_limit_max = 200000;
  87
  88 static struct ctl_table_header *raid_table_header;
  89
  90 static ctl_table raid_table[] = {
  91         {
  92                 .ctl_name       = DEV_RAID_SPEED_LIMIT_MIN,
  93                 .procname       = "speed_limit_min",
  94                 .data           = &sysctl_speed_limit_min,
  95                 .maxlen         = sizeof(int),
  96                 .mode           = 0644,
  97                 .proc_handler   = &proc_dointvec,
  98         },
  99         {
 100                 .ctl_name       = DEV_RAID_SPEED_LIMIT_MAX,
 101                 .procname       = "speed_limit_max",
 102                 .data           = &sysctl_speed_limit_max,
 103                 .maxlen         = sizeof(int),
 104                 .mode           = 0644,
 105                 .proc_handler   = &proc_dointvec,
 106         },
 107         { .ctl_name = 0 }
 108 };
 109
 110 static ctl_table raid_dir_table[] = {
 111         {
 112                 .ctl_name       = DEV_RAID,
 113                 .procname       = "raid",
 114                 .maxlen         = 0,
 115                 .mode           = 0555,
 116                 .child          = raid_table,
 117         },
 118         { .ctl_name = 0 }
 119 };
 120
 121 static ctl_table raid_root_table[] = {
 122         {
 123                 .ctl_name       = CTL_DEV,
 124                 .procname       = "dev",
 125                 .maxlen         = 0,
 126                 .mode           = 0555,
 127                 .child          = raid_dir_table,
 128         },
 129         { .ctl_name = 0 }
 130 };
 131
 132 static struct block_device_operations md_fops;
 133
 134 /*
 135  * Enables to iterate over all existing md arrays
 136  * all_mddevs_lock protects this list.
 137  */
 138 static LIST_HEAD(all_mddevs);
 139 static DEFINE_SPINLOCK(all_mddevs_lock);
 140
 141
 142 /*
 143  * iterates through all used mddevs in the system.
 144  * We take care to grab the all_mddevs_lock whenever navigating
 145  * the list, and to always hold a refcount when unlocked.
 146  * Any code which breaks out of this loop while own
 147  * a reference to the current mddev and must mddev_put it.
 148  */
 149 #define ITERATE_MDDEV(mddev,tmp)                                        \
 150                                                                         \
 151         for (({ spin_lock(&all_mddevs_lock);                            \
 152                 tmp = all_mddevs.next;                                  \
 153                 mddev = NULL;});                                        \
 154              ({ if (tmp != &all_mddevs)                                 \
 155                         mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
 156                 spin_unlock(&all_mddevs_lock);                          \
 157                 if (mddev) mddev_put(mddev);                            \
 158                 mddev = list_entry(tmp, mddev_t, all_mddevs);           \
 159                 tmp != &all_mddevs;});                                  \
 160              ({ spin_lock(&all_mddevs_lock);                            \
 161                 tmp = tmp->next;})                                      \
 162                 )
 163
 164
 165 static int md_fail_request (request_queue_t *q, struct bio *bio)
 166 {
 167         bio_io_error(bio, bio->bi_size);
 168         return 0;
 169 }
 170
 171 static inline mddev_t *mddev_get(mddev_t *mddev)
 172 {
 173         atomic_inc(&mddev->active);
 174         return mddev;
 175 }
 176
 177 static void mddev_put(mddev_t *mddev)
 178 {
 179         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
 180                 return;
 181         if (!mddev->raid_disks && list_empty(&mddev->disks)) {
 182                 list_del(&mddev->all_mddevs);
 183                 blk_put_queue(mddev->queue);
 184                 kobject_unregister(&mddev->kobj);
 185         }
 186         spin_unlock(&all_mddevs_lock);
 187 }
 188
 189 static mddev_t * mddev_find(dev_t unit)
 190 {
 191         mddev_t *mddev, *new = NULL;
 192
 193  retry:
 194         spin_lock(&all_mddevs_lock);
 195         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
 196                 if (mddev->unit == unit) {
 197                         mddev_get(mddev);
 198                         spin_unlock(&all_mddevs_lock);
 199                         kfree(new);
 200                         return mddev;
 201                 }
 202
 203         if (new) {
 204                 list_add(&new->all_mddevs, &all_mddevs);
 205                 spin_unlock(&all_mddevs_lock);
 206                 return new;
 207         }
 208         spin_unlock(&all_mddevs_lock);
 209
 210         new = (mddev_t *) kmalloc(sizeof(*new), GFP_KERNEL);
 211         if (!new)
 212                 return NULL;
 213
 214         memset(new, 0, sizeof(*new));
 215
 216         new->unit = unit;
 217         if (MAJOR(unit) == MD_MAJOR)
 218                 new->md_minor = MINOR(unit);
 219         else
 220                 new->md_minor = MINOR(unit) >> MdpMinorShift;
 221
 222         init_MUTEX(&new->reconfig_sem);
 223         INIT_LIST_HEAD(&new->disks);
 224         INIT_LIST_HEAD(&new->all_mddevs);
 225         init_timer(&new->safemode_timer);
 226         atomic_set(&new->active, 1);
 227         spin_lock_init(&new->write_lock);
 228         init_waitqueue_head(&new->sb_wait);
 229
 230         new->queue = blk_alloc_queue(GFP_KERNEL);
 231         if (!new->queue) {
 232                 kfree(new);
 233                 return NULL;
 234         }
 235
 236         blk_queue_make_request(new->queue, md_fail_request);
 237
 238         goto retry;
 239 }
 240
 241 static inline int mddev_lock(mddev_t * mddev)
 242 {
 243         return down_interruptible(&mddev->reconfig_sem);
 244 }
 245
 246 static inline void mddev_lock_uninterruptible(mddev_t * mddev)
 247 {
 248         down(&mddev->reconfig_sem);
 249 }
 250
 251 static inline int mddev_trylock(mddev_t * mddev)
 252 {
 253         return down_trylock(&mddev->reconfig_sem);
 254 }
 255
 256 static inline void mddev_unlock(mddev_t * mddev)
 257 {
 258         up(&mddev->reconfig_sem);
 259
 260         md_wakeup_thread(mddev->thread);
 261 }
 262
 263 mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
 264 {
 265         mdk_rdev_t * rdev;
 266         struct list_head *tmp;
 267
 268         ITERATE_RDEV(mddev,rdev,tmp) {
 269                 if (rdev->desc_nr == nr)
 270                         return rdev;
 271         }
 272         return NULL;
 273 }
 274
 275 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
 276 {
 277         struct list_head *tmp;
 278         mdk_rdev_t *rdev;
 279
 280         ITERATE_RDEV(mddev,rdev,tmp) {
 281                 if (rdev->bdev->bd_dev == dev)
 282                         return rdev;
 283         }
 284         return NULL;
 285 }
 286
 287 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
 288 {
 289         sector_t size = bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
 290         return MD_NEW_SIZE_BLOCKS(size);
 291 }
 292
 293 static sector_t calc_dev_size(mdk_rdev_t *rdev, unsigned chunk_size)
 294 {
 295         sector_t size;
 296
 297         size = rdev->sb_offset;
 298
 299         if (chunk_size)
 300                 size &= ~((sector_t)chunk_size/1024 - 1);
 301         return size;
 302 }
 303
 304 static int alloc_disk_sb(mdk_rdev_t * rdev)
 305 {
 306         if (rdev->sb_page)
 307                 MD_BUG();
 308
 309         rdev->sb_page = alloc_page(GFP_KERNEL);
 310         if (!rdev->sb_page) {
 311                 printk(KERN_ALERT "md: out of memory.\n");
 312                 return -EINVAL;
 313         }
 314
 315         return 0;
 316 }
 317
 318 static void free_disk_sb(mdk_rdev_t * rdev)
 319 {
 320         if (rdev->sb_page) {
 321                 page_cache_release(rdev->sb_page);
 322                 rdev->sb_loaded = 0;
 323                 rdev->sb_page = NULL;
 324                 rdev->sb_offset = 0;
 325                 rdev->size = 0;
 326         }
 327 }
 328
 329
 330 static int super_written(struct bio *bio, unsigned int bytes_done, int error)
 331 {
 332         mdk_rdev_t *rdev = bio->bi_private;
 333         if (bio->bi_size)
 334                 return 1;
 335
 336         if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags))
 337                 md_error(rdev->mddev, rdev);
 338
 339         if (atomic_dec_and_test(&rdev->mddev->pending_writes))
 340                 wake_up(&rdev->mddev->sb_wait);
 341         bio_put(bio);
 342         return 0;
 343 }
 344
 345 void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
 346                    sector_t sector, int size, struct page *page)
 347 {
 348         /* write first size bytes of page to sector of rdev
 349          * Increment mddev->pending_writes before returning
 350          * and decrement it on completion, waking up sb_wait
 351          * if zero is reached.
 352          * If an error occurred, call md_error
 353          */
 354         struct bio *bio = bio_alloc(GFP_NOIO, 1);
 355
 356         bio->bi_bdev = rdev->bdev;
 357         bio->bi_sector = sector;
 358         bio_add_page(bio, page, size, 0);
 359         bio->bi_private = rdev;
 360         bio->bi_end_io = super_written;
 361         atomic_inc(&mddev->pending_writes);
 362         submit_bio((1<<BIO_RW)|(1<<BIO_RW_SYNC), bio);
 363 }
 364
 365 static int bi_complete(struct bio *bio, unsigned int bytes_done, int error)
 366 {
 367         if (bio->bi_size)
 368                 return 1;
 369
 370         complete((struct completion*)bio->bi_private);
 371         return 0;
 372 }
 373
 374 int sync_page_io(struct block_device *bdev, sector_t sector, int size,
 375                    struct page *page, int rw)
 376 {
 377         struct bio *bio = bio_alloc(GFP_NOIO, 1);
 378         struct completion event;
 379         int ret;
 380
 381         rw |= (1 << BIO_RW_SYNC);
 382
 383         bio->bi_bdev = bdev;
 384         bio->bi_sector = sector;
 385         bio_add_page(bio, page, size, 0);
 386         init_completion(&event);
 387         bio->bi_private = &event;
 388         bio->bi_end_io = bi_complete;
 389         submit_bio(rw, bio);
 390         wait_for_completion(&event);
 391
 392         ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
 393         bio_put(bio);
 394         return ret;
 395 }
 396
 397 static int read_disk_sb(mdk_rdev_t * rdev, int size)
 398 {
 399         char b[BDEVNAME_SIZE];
 400         if (!rdev->sb_page) {
 401                 MD_BUG();
 402                 return -EINVAL;
 403         }
 404         if (rdev->sb_loaded)
 405                 return 0;
 406
 407
 408         if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, size, rdev->sb_page, READ))
 409                 goto fail;
 410         rdev->sb_loaded = 1;
 411         return 0;
 412
 413 fail:
 414         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
 415                 bdevname(rdev->bdev,b));
 416         return -EINVAL;
 417 }
 418
 419 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
 420 {
 421         if (    (sb1->set_uuid0 == sb2->set_uuid0) &&
 422                 (sb1->set_uuid1 == sb2->set_uuid1) &&
 423                 (sb1->set_uuid2 == sb2->set_uuid2) &&
 424                 (sb1->set_uuid3 == sb2->set_uuid3))
 425
 426                 return 1;
 427
 428         return 0;
 429 }
 430
 431
 432 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
 433 {
 434         int ret;
 435         mdp_super_t *tmp1, *tmp2;
 436
 437         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
 438         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
 439
 440         if (!tmp1 || !tmp2) {
 441                 ret = 0;
 442                 printk(KERN_INFO "md.c: sb1 is not equal to sb2!\n");
 443                 goto abort;
 444         }
 445
 446         *tmp1 = *sb1;
 447         *tmp2 = *sb2;
 448
 449         /*
 450          * nr_disks is not constant
 451          */
 452         tmp1->nr_disks = 0;
 453         tmp2->nr_disks = 0;
 454
 455         if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
 456                 ret = 0;
 457         else
 458                 ret = 1;
 459
 460 abort:
 461         kfree(tmp1);
 462         kfree(tmp2);
 463         return ret;
 464 }
 465
 466 static unsigned int calc_sb_csum(mdp_super_t * sb)
 467 {
 468         unsigned int disk_csum, csum;
 469
 470         disk_csum = sb->sb_csum;
 471         sb->sb_csum = 0;
 472         csum = csum_partial((void *)sb, MD_SB_BYTES, 0);
 473         sb->sb_csum = disk_csum;
 474         return csum;
 475 }
 476
 477
 478 /*
 479  * Handle superblock details.
 480  * We want to be able to handle multiple superblock formats
 481  * so we have a common interface to them all, and an array of
 482  * different handlers.
 483  * We rely on user-space to write the initial superblock, and support
 484  * reading and updating of superblocks.
 485  * Interface methods are:
 486  *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
 487  *      loads and validates a superblock on dev.
 488  *      if refdev != NULL, compare superblocks on both devices
 489  *    Return:
 490  *      0 - dev has a superblock that is compatible with refdev
 491  *      1 - dev has a superblock that is compatible and newer than refdev
 492  *          so dev should be used as the refdev in future
 493  *     -EINVAL superblock incompatible or invalid
 494  *     -othererror e.g. -EIO
 495  *
 496  *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
 497  *      Verify that dev is acceptable into mddev.
 498  *       The first time, mddev->raid_disks will be 0, and data from
 499  *       dev should be merged in.  Subsequent calls check that dev
 500  *       is new enough.  Return 0 or -EINVAL
 501  *
 502  *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
 503  *     Update the superblock for rdev with data in mddev
 504  *     This does not write to disc.
 505  *
 506  */
 507
 508 struct super_type  {
 509         char            *name;
 510         struct module   *owner;
 511         int             (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version);
 512         int             (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
 513         void            (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
 514 };
 515
 516 /*
 517  * load_super for 0.90.0
 518  */
 519 static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
 520 {
 521         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
 522         mdp_super_t *sb;
 523         int ret;
 524         sector_t sb_offset;
 525
 526         /*
 527          * Calculate the position of the superblock,
 528          * it's at the end of the disk.
 529          *
 530          * It also happens to be a multiple of 4Kb.
 531          */
 532         sb_offset = calc_dev_sboffset(rdev->bdev);
 533         rdev->sb_offset = sb_offset;
 534
 535         ret = read_disk_sb(rdev, MD_SB_BYTES);
 536         if (ret) return ret;
 537
 538         ret = -EINVAL;
 539
 540         bdevname(rdev->bdev, b);
 541         sb = (mdp_super_t*)page_address(rdev->sb_page);
 542
 543         if (sb->md_magic != MD_SB_MAGIC) {
 544                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
 545                        b);
 546                 goto abort;
 547         }
 548
 549         if (sb->major_version != 0 ||
 550             sb->minor_version != 90) {
 551                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
 552                         sb->major_version, sb->minor_version,
 553                         b);
 554                 goto abort;
 555         }
 556
 557         if (sb->raid_disks <= 0)
 558                 goto abort;
 559
 560         if (csum_fold(calc_sb_csum(sb)) != csum_fold(sb->sb_csum)) {
 561                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
 562                         b);
 563                 goto abort;
 564         }
 565
 566         rdev->preferred_minor = sb->md_minor;
 567         rdev->data_offset = 0;
 568         rdev->sb_size = MD_SB_BYTES;
 569
 570         if (sb->level == LEVEL_MULTIPATH)
 571                 rdev->desc_nr = -1;
 572         else
 573                 rdev->desc_nr = sb->this_disk.number;
 574
 575         if (refdev == 0)
 576                 ret = 1;
 577         else {
 578                 __u64 ev1, ev2;
 579                 mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
 580                 if (!uuid_equal(refsb, sb)) {
 581                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
 582                                 b, bdevname(refdev->bdev,b2));
 583                         goto abort;
 584                 }
 585                 if (!sb_equal(refsb, sb)) {
 586                         printk(KERN_WARNING "md: %s has same UUID"
 587                                " but different superblock to %s\n",
 588                                b, bdevname(refdev->bdev, b2));
 589                         goto abort;
 590                 }
 591                 ev1 = md_event(sb);
 592                 ev2 = md_event(refsb);
 593                 if (ev1 > ev2)
 594                         ret = 1;
 595                 else
 596                         ret = 0;
 597         }
 598         rdev->size = calc_dev_size(rdev, sb->chunk_size);
 599
 600  abort:
 601         return ret;
 602 }
 603
 604 /*
 605  * validate_super for 0.90.0
 606  */
 607 static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 608 {
 609         mdp_disk_t *desc;
 610         mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
 611
 612         rdev->raid_disk = -1;
 613         rdev->in_sync = 0;
 614         if (mddev->raid_disks == 0) {
 615                 mddev->major_version = 0;
 616                 mddev->minor_version = sb->minor_version;
 617                 mddev->patch_version = sb->patch_version;
 618                 mddev->persistent = ! sb->not_persistent;
 619                 mddev->chunk_size = sb->chunk_size;
 620                 mddev->ctime = sb->ctime;
 621                 mddev->utime = sb->utime;
 622                 mddev->level = sb->level;
 623                 mddev->layout = sb->layout;
 624                 mddev->raid_disks = sb->raid_disks;
 625                 mddev->size = sb->size;
 626                 mddev->events = md_event(sb);
 627                 mddev->bitmap_offset = 0;
 628                 mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
 629
 630                 if (sb->state & (1<<MD_SB_CLEAN))
 631                         mddev->recovery_cp = MaxSector;
 632                 else {
 633                         if (sb->events_hi == sb->cp_events_hi &&
 634                                 sb->events_lo == sb->cp_events_lo) {
 635                                 mddev->recovery_cp = sb->recovery_cp;
 636                         } else
 637                                 mddev->recovery_cp = 0;
 638                 }
 639
 640                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
 641                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
 642                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
 643                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
 644
 645                 mddev->max_disks = MD_SB_DISKS;
 646
 647                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
 648                     mddev->bitmap_file == NULL) {
 649                         if (mddev->level != 1 && mddev->level != 5 && mddev->level != 6) {
 650                                 /* FIXME use a better test */
 651                                 printk(KERN_WARNING "md: bitmaps only support for raid1\n");
 652                                 return -EINVAL;
 653                         }
 654                         mddev->bitmap_offset = mddev->default_bitmap_offset;
 655                 }
 656
 657         } else if (mddev->pers == NULL) {
 658                 /* Insist on good event counter while assembling */
 659                 __u64 ev1 = md_event(sb);
 660                 ++ev1;
 661                 if (ev1 < mddev->events)
 662                         return -EINVAL;
 663         } else if (mddev->bitmap) {
 664                 /* if adding to array with a bitmap, then we can accept an
 665                  * older device ... but not too old.
 666                  */
 667                 __u64 ev1 = md_event(sb);
 668                 if (ev1 < mddev->bitmap->events_cleared)
 669                         return 0;
 670         } else /* just a hot-add of a new device, leave raid_disk at -1 */
 671                 return 0;
 672
 673         if (mddev->level != LEVEL_MULTIPATH) {
 674                 rdev->faulty = 0;
 675                 rdev->flags = 0;
 676                 desc = sb->disks + rdev->desc_nr;
 677
 678                 if (desc->state & (1<<MD_DISK_FAULTY))
 679                         rdev->faulty = 1;
 680                 else if (desc->state & (1<<MD_DISK_SYNC) &&
 681                          desc->raid_disk < mddev->raid_disks) {
 682                         rdev->in_sync = 1;
 683                         rdev->raid_disk = desc->raid_disk;
 684                 }
 685                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
 686                         set_bit(WriteMostly, &rdev->flags);
 687         } else /* MULTIPATH are always insync */
 688                 rdev->in_sync = 1;
 689         return 0;
 690 }
 691
 692 /*
 693  * sync_super for 0.90.0
 694  */
 695 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 696 {
 697         mdp_super_t *sb;
 698         struct list_head *tmp;
 699         mdk_rdev_t *rdev2;
 700         int next_spare = mddev->raid_disks;
 701
 702         /* make rdev->sb match mddev data..
 703          *
 704          * 1/ zero out disks
 705          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
 706          * 3/ any empty disks < next_spare become removed
 707          *
 708          * disks[0] gets initialised to REMOVED because
 709          * we cannot be sure from other fields if it has
 710          * been initialised or not.
 711          */
 712         int i;
 713         int active=0, working=0,failed=0,spare=0,nr_disks=0;
 714
 715         rdev->sb_size = MD_SB_BYTES;
 716
 717         sb = (mdp_super_t*)page_address(rdev->sb_page);
 718
 719         memset(sb, 0, sizeof(*sb));
 720
 721         sb->md_magic = MD_SB_MAGIC;
 722         sb->major_version = mddev->major_version;
 723         sb->minor_version = mddev->minor_version;
 724         sb->patch_version = mddev->patch_version;
 725         sb->gvalid_words  = 0; /* ignored */
 726         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
 727         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
 728         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
 729         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
 730
 731         sb->ctime = mddev->ctime;
 732         sb->level = mddev->level;
 733         sb->size  = mddev->size;
 734         sb->raid_disks = mddev->raid_disks;
 735         sb->md_minor = mddev->md_minor;
 736         sb->not_persistent = !mddev->persistent;
 737         sb->utime = mddev->utime;
 738         sb->state = 0;
 739         sb->events_hi = (mddev->events>>32);
 740         sb->events_lo = (u32)mddev->events;
 741
 742         if (mddev->in_sync)
 743         {
 744                 sb->recovery_cp = mddev->recovery_cp;
 745                 sb->cp_events_hi = (mddev->events>>32);
 746                 sb->cp_events_lo = (u32)mddev->events;
 747                 if (mddev->recovery_cp == MaxSector)
 748                         sb->state = (1<< MD_SB_CLEAN);
 749         } else
 750                 sb->recovery_cp = 0;
 751
 752         sb->layout = mddev->layout;
 753         sb->chunk_size = mddev->chunk_size;
 754
 755         if (mddev->bitmap && mddev->bitmap_file == NULL)
 756                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
 757
 758         sb->disks[0].state = (1<<MD_DISK_REMOVED);
 759         ITERATE_RDEV(mddev,rdev2,tmp) {
 760                 mdp_disk_t *d;
 761                 if (rdev2->raid_disk >= 0 && rdev2->in_sync && !rdev2->faulty)
 762                         rdev2->desc_nr = rdev2->raid_disk;
 763                 else
 764                         rdev2->desc_nr = next_spare++;
 765                 d = &sb->disks[rdev2->desc_nr];
 766                 nr_disks++;
 767                 d->number = rdev2->desc_nr;
 768                 d->major = MAJOR(rdev2->bdev->bd_dev);
 769                 d->minor = MINOR(rdev2->bdev->bd_dev);
 770                 if (rdev2->raid_disk >= 0 && rdev->in_sync && !rdev2->faulty)
 771                         d->raid_disk = rdev2->raid_disk;
 772                 else
 773                         d->raid_disk = rdev2->desc_nr; /* compatibility */
 774                 if (rdev2->faulty) {
 775                         d->state = (1<<MD_DISK_FAULTY);
 776                         failed++;
 777                 } else if (rdev2->in_sync) {
 778                         d->state = (1<<MD_DISK_ACTIVE);
 779                         d->state |= (1<<MD_DISK_SYNC);
 780                         active++;
 781                         working++;
 782                 } else {
 783                         d->state = 0;
 784                         spare++;
 785                         working++;
 786                 }
 787                 if (test_bit(WriteMostly, &rdev2->flags))
 788                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
 789         }
 790
 791         /* now set the "removed" and "faulty" bits on any missing devices */
 792         for (i=0 ; i < mddev->raid_disks ; i++) {
 793                 mdp_disk_t *d = &sb->disks[i];
 794                 if (d->state == 0 && d->number == 0) {
 795                         d->number = i;
 796                         d->raid_disk = i;
 797                         d->state = (1<<MD_DISK_REMOVED);
 798                         d->state |= (1<<MD_DISK_FAULTY);
 799                         failed++;
 800                 }
 801         }
 802         sb->nr_disks = nr_disks;
 803         sb->active_disks = active;
 804         sb->working_disks = working;
 805         sb->failed_disks = failed;
 806         sb->spare_disks = spare;
 807
 808         sb->this_disk = sb->disks[rdev->desc_nr];
 809         sb->sb_csum = calc_sb_csum(sb);
 810 }
 811
 812 /*
 813  * version 1 superblock
 814  */
 815
 816 static unsigned int calc_sb_1_csum(struct mdp_superblock_1 * sb)
 817 {
 818         unsigned int disk_csum, csum;
 819         unsigned long long newcsum;
 820         int size = 256 + le32_to_cpu(sb->max_dev)*2;
 821         unsigned int *isuper = (unsigned int*)sb;
 822         int i;
 823
 824         disk_csum = sb->sb_csum;
 825         sb->sb_csum = 0;
 826         newcsum = 0;
 827         for (i=0; size>=4; size -= 4 )
 828                 newcsum += le32_to_cpu(*isuper++);
 829
 830         if (size == 2)
 831                 newcsum += le16_to_cpu(*(unsigned short*) isuper);
 832
 833         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
 834         sb->sb_csum = disk_csum;
 835         return cpu_to_le32(csum);
 836 }
 837
 838 static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
 839 {
 840         struct mdp_superblock_1 *sb;
 841         int ret;
 842         sector_t sb_offset;
 843         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
 844         int bmask;
 845
 846         /*
 847          * Calculate the position of the superblock.
 848          * It is always aligned to a 4K boundary and
 849          * depeding on minor_version, it can be:
 850          * 0: At least 8K, but less than 12K, from end of device
 851          * 1: At start of device
 852          * 2: 4K from start of device.
 853          */
 854         switch(minor_version) {
 855         case 0:
 856                 sb_offset = rdev->bdev->bd_inode->i_size >> 9;
 857                 sb_offset -= 8*2;
 858                 sb_offset &= ~(sector_t)(4*2-1);
 859                 /* convert from sectors to K */
 860                 sb_offset /= 2;
 861                 break;
 862         case 1:
 863                 sb_offset = 0;
 864                 break;
 865         case 2:
 866                 sb_offset = 4;
 867                 break;
 868         default:
 869                 return -EINVAL;
 870         }
 871         rdev->sb_offset = sb_offset;
 872
 873         /* superblock is rarely larger than 1K, but it can be larger,
 874          * and it is safe to read 4k, so we do that
 875          */
 876         ret = read_disk_sb(rdev, 4096);
 877         if (ret) return ret;
 878
 879
 880         sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
 881
 882         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
 883             sb->major_version != cpu_to_le32(1) ||
 884             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
 885             le64_to_cpu(sb->super_offset) != (rdev->sb_offset<<1) ||
 886             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
 887                 return -EINVAL;
 888
 889         if (calc_sb_1_csum(sb) != sb->sb_csum) {
 890                 printk("md: invalid superblock checksum on %s\n",
 891                         bdevname(rdev->bdev,b));
 892                 return -EINVAL;
 893         }
 894         if (le64_to_cpu(sb->data_size) < 10) {
 895                 printk("md: data_size too small on %s\n",
 896                        bdevname(rdev->bdev,b));
 897                 return -EINVAL;
 898         }
 899         rdev->preferred_minor = 0xffff;
 900         rdev->data_offset = le64_to_cpu(sb->data_offset);
 901
 902         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
 903         bmask = queue_hardsect_size(rdev->bdev->bd_disk->queue)-1;
 904         if (rdev->sb_size & bmask)
 905                 rdev-> sb_size = (rdev->sb_size | bmask)+1;
 906
 907         if (refdev == 0)
 908                 return 1;
 909         else {
 910                 __u64 ev1, ev2;
 911                 struct mdp_superblock_1 *refsb =
 912                         (struct mdp_superblock_1*)page_address(refdev->sb_page);
 913
 914                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
 915                     sb->level != refsb->level ||
 916                     sb->layout != refsb->layout ||
 917                     sb->chunksize != refsb->chunksize) {
 918                         printk(KERN_WARNING "md: %s has strangely different"
 919                                 " superblock to %s\n",
 920                                 bdevname(rdev->bdev,b),
 921                                 bdevname(refdev->bdev,b2));
 922                         return -EINVAL;
 923                 }
 924                 ev1 = le64_to_cpu(sb->events);
 925                 ev2 = le64_to_cpu(refsb->events);
 926
 927                 if (ev1 > ev2)
 928                         return 1;
 929         }
 930         if (minor_version)
 931                 rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
 932         else
 933                 rdev->size = rdev->sb_offset;
 934         if (rdev->size < le64_to_cpu(sb->data_size)/2)
 935                 return -EINVAL;
 936         rdev->size = le64_to_cpu(sb->data_size)/2;
 937         if (le32_to_cpu(sb->chunksize))
 938                 rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
 939         return 0;
 940 }
 941
 942 static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 943 {
 944         struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
 945
 946         rdev->raid_disk = -1;
 947         rdev->in_sync = 0;
 948         if (mddev->raid_disks == 0) {
 949                 mddev->major_version = 1;
 950                 mddev->patch_version = 0;
 951                 mddev->persistent = 1;
 952                 mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9;
 953                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
 954                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
 955                 mddev->level = le32_to_cpu(sb->level);
 956                 mddev->layout = le32_to_cpu(sb->layout);
 957                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
 958                 mddev->size = le64_to_cpu(sb->size)/2;
 959                 mddev->events = le64_to_cpu(sb->events);
 960                 mddev->bitmap_offset = 0;
 961                 mddev->default_bitmap_offset = 0;
 962                 mddev->default_bitmap_offset = 1024;
 963
 964                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
 965                 memcpy(mddev->uuid, sb->set_uuid, 16);
 966
 967                 mddev->max_disks =  (4096-256)/2;
 968
 969                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
 970                     mddev->bitmap_file == NULL ) {
 971                         if (mddev->level != 1) {
 972                                 printk(KERN_WARNING "md: bitmaps only supported for raid1\n");
 973                                 return -EINVAL;
 974                         }
 975                         mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
 976                 }
 977         } else if (mddev->pers == NULL) {
 978                 /* Insist of good event counter while assembling */
 979                 __u64 ev1 = le64_to_cpu(sb->events);
 980                 ++ev1;
 981                 if (ev1 < mddev->events)
 982                         return -EINVAL;
 983         } else if (mddev->bitmap) {
 984                 /* If adding to array with a bitmap, then we can accept an
 985                  * older device, but not too old.
 986                  */
 987                 __u64 ev1 = le64_to_cpu(sb->events);
 988                 if (ev1 < mddev->bitmap->events_cleared)
 989                         return 0;
 990         } else /* just a hot-add of a new device, leave raid_disk at -1 */
 991                 return 0;
 992
 993         if (mddev->level != LEVEL_MULTIPATH) {
 994                 int role;
 995                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
 996                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
 997                 switch(role) {
 998                 case 0xffff: /* spare */
 999                         rdev->faulty = 0;
1000                         break;
1001                 case 0xfffe: /* faulty */
1002                         rdev->faulty = 1;
1003                         break;
1004                 default:
1005                         rdev->in_sync = 1;
1006                         rdev->faulty = 0;
1007                         rdev->raid_disk = role;
1008                         break;
1009                 }
1010                 rdev->flags = 0;
1011                 if (sb->devflags & WriteMostly1)
1012                         set_bit(WriteMostly, &rdev->flags);
1013         } else /* MULTIPATH are always insync */
1014                 rdev->in_sync = 1;
1015
1016         return 0;
1017 }
1018
1019 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
1020 {
1021         struct mdp_superblock_1 *sb;
1022         struct list_head *tmp;
1023         mdk_rdev_t *rdev2;
1024         int max_dev, i;
1025         /* make rdev->sb match mddev and rdev data. */
1026
1027         sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
1028
1029         sb->feature_map = 0;
1030         sb->pad0 = 0;
1031         memset(sb->pad1, 0, sizeof(sb->pad1));
1032         memset(sb->pad2, 0, sizeof(sb->pad2));
1033         memset(sb->pad3, 0, sizeof(sb->pad3));
1034
1035         sb->utime = cpu_to_le64((__u64)mddev->utime);
1036         sb->events = cpu_to_le64(mddev->events);
1037         if (mddev->in_sync)
1038                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1039         else
1040                 sb->resync_offset = cpu_to_le64(0);
1041
1042         if (mddev->bitmap && mddev->bitmap_file == NULL) {
1043                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
1044                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1045         }
1046
1047         max_dev = 0;
1048         ITERATE_RDEV(mddev,rdev2,tmp)
1049                 if (rdev2->desc_nr+1 > max_dev)
1050                         max_dev = rdev2->desc_nr+1;
1051
1052         sb->max_dev = cpu_to_le32(max_dev);
1053         for (i=0; i<max_dev;i++)
1054                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
1055
1056         ITERATE_RDEV(mddev,rdev2,tmp) {
1057                 i = rdev2->desc_nr;
1058                 if (rdev2->faulty)
1059                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
1060                 else if (rdev2->in_sync)
1061                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1062                 else
1063                         sb->dev_roles[i] = cpu_to_le16(0xffff);
1064         }
1065
1066         sb->recovery_offset = cpu_to_le64(0); /* not supported yet */
1067         sb->sb_csum = calc_sb_1_csum(sb);
1068 }
1069
1070
1071 static struct super_type super_types[] = {
1072         [0] = {
1073                 .name   = "0.90.0",
1074                 .owner  = THIS_MODULE,
1075                 .load_super     = super_90_load,
1076                 .validate_super = super_90_validate,
1077                 .sync_super     = super_90_sync,
1078         },
1079         [1] = {
1080                 .name   = "md-1",
1081                 .owner  = THIS_MODULE,
1082                 .load_super     = super_1_load,
1083                 .validate_super = super_1_validate,
1084                 .sync_super     = super_1_sync,
1085         },
1086 };
1087
1088 static mdk_rdev_t * match_dev_unit(mddev_t *mddev, mdk_rdev_t *dev)
1089 {
1090         struct list_head *tmp;
1091         mdk_rdev_t *rdev;
1092
1093         ITERATE_RDEV(mddev,rdev,tmp)
1094                 if (rdev->bdev->bd_contains == dev->bdev->bd_contains)
1095                         return rdev;
1096
1097         return NULL;
1098 }
1099
1100 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
1101 {
1102         struct list_head *tmp;
1103         mdk_rdev_t *rdev;
1104
1105         ITERATE_RDEV(mddev1,rdev,tmp)
1106                 if (match_dev_unit(mddev2, rdev))
1107                         return 1;
1108
1109         return 0;
1110 }
1111
1112 static LIST_HEAD(pending_raid_disks);
1113
1114 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
1115 {
1116         mdk_rdev_t *same_pdev;
1117         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1118
1119         if (rdev->mddev) {
1120                 MD_BUG();
1121                 return -EINVAL;
1122         }
1123         same_pdev = match_dev_unit(mddev, rdev);
1124         if (same_pdev)
1125                 printk(KERN_WARNING
1126                         "%s: WARNING: %s appears to be on the same physical"
1127                         " disk as %s. True\n     protection against single-disk"
1128                         " failure might be compromised.\n",
1129                         mdname(mddev), bdevname(rdev->bdev,b),
1130                         bdevname(same_pdev->bdev,b2));
1131
1132         /* Verify rdev->desc_nr is unique.
1133          * If it is -1, assign a free number, else
1134          * check number is not in use
1135          */
1136         if (rdev->desc_nr < 0) {
1137                 int choice = 0;
1138                 if (mddev->pers) choice = mddev->raid_disks;
1139                 while (find_rdev_nr(mddev, choice))
1140                         choice++;
1141                 rdev->desc_nr = choice;
1142         } else {
1143                 if (find_rdev_nr(mddev, rdev->desc_nr))
1144                         return -EBUSY;
1145         }
1146
1147         list_add(&rdev->same_set, &mddev->disks);
1148         rdev->mddev = mddev;
1149         printk(KERN_INFO "md: bind<%s>\n", bdevname(rdev->bdev,b));
1150         return 0;
1151 }
1152
1153 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
1154 {
1155         char b[BDEVNAME_SIZE];
1156         if (!rdev->mddev) {
1157                 MD_BUG();
1158                 return;
1159         }
1160         list_del_init(&rdev->same_set);
1161         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
1162         rdev->mddev = NULL;
1163 }
1164
1165 /*
1166  * prevent the device from being mounted, repartitioned or
1167  * otherwise reused by a RAID array (or any other kernel
1168  * subsystem), by bd_claiming the device.
1169  */
1170 static int lock_rdev(mdk_rdev_t *rdev, dev_t dev)
1171 {
1172         int err = 0;
1173         struct block_device *bdev;
1174         char b[BDEVNAME_SIZE];
1175
1176         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
1177         if (IS_ERR(bdev)) {
1178                 printk(KERN_ERR "md: could not open %s.\n",
1179                         __bdevname(dev, b));
1180                 return PTR_ERR(bdev);
1181         }
1182         err = bd_claim(bdev, rdev);
1183         if (err) {
1184                 printk(KERN_ERR "md: could not bd_claim %s.\n",
1185                         bdevname(bdev, b));
1186                 blkdev_put(bdev);
1187                 return err;
1188         }
1189         rdev->bdev = bdev;
1190         return err;
1191 }
1192
1193 static void unlock_rdev(mdk_rdev_t *rdev)
1194 {
1195         struct block_device *bdev = rdev->bdev;
1196         rdev->bdev = NULL;
1197         if (!bdev)
1198                 MD_BUG();
1199         bd_release(bdev);
1200         blkdev_put(bdev);
1201 }
1202
1203 void md_autodetect_dev(dev_t dev);
1204
1205 static void export_rdev(mdk_rdev_t * rdev)
1206 {
1207         char b[BDEVNAME_SIZE];
1208         printk(KERN_INFO "md: export_rdev(%s)\n",
1209                 bdevname(rdev->bdev,b));
1210         if (rdev->mddev)
1211                 MD_BUG();
1212         free_disk_sb(rdev);
1213         list_del_init(&rdev->same_set);
1214 #ifndef MODULE
1215         md_autodetect_dev(rdev->bdev->bd_dev);
1216 #endif
1217         unlock_rdev(rdev);
1218         kfree(rdev);
1219 }
1220
1221 static void kick_rdev_from_array(mdk_rdev_t * rdev)
1222 {
1223         unbind_rdev_from_array(rdev);
1224         export_rdev(rdev);
1225 }
1226
1227 static void export_array(mddev_t *mddev)
1228 {
1229         struct list_head *tmp;
1230         mdk_rdev_t *rdev;
1231
1232         ITERATE_RDEV(mddev,rdev,tmp) {
1233                 if (!rdev->mddev) {
1234                         MD_BUG();
1235                         continue;
1236                 }
1237                 kick_rdev_from_array(rdev);
1238         }
1239         if (!list_empty(&mddev->disks))
1240                 MD_BUG();
1241         mddev->raid_disks = 0;
1242         mddev->major_version = 0;
1243 }
1244
1245 static void print_desc(mdp_disk_t *desc)
1246 {
1247         printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
1248                 desc->major,desc->minor,desc->raid_disk,desc->state);
1249 }
1250
1251 static void print_sb(mdp_super_t *sb)
1252 {
1253         int i;
1254
1255         printk(KERN_INFO
1256                 "md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
1257                 sb->major_version, sb->minor_version, sb->patch_version,
1258                 sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
1259                 sb->ctime);
1260         printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n",
1261                 sb->level, sb->size, sb->nr_disks, sb->raid_disks,
1262                 sb->md_minor, sb->layout, sb->chunk_size);
1263         printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d"
1264                 " FD:%d SD:%d CSUM:%08x E:%08lx\n",
1265                 sb->utime, sb->state, sb->active_disks, sb->working_disks,
1266                 sb->failed_disks, sb->spare_disks,
1267                 sb->sb_csum, (unsigned long)sb->events_lo);
1268
1269         printk(KERN_INFO);
1270         for (i = 0; i < MD_SB_DISKS; i++) {
1271                 mdp_disk_t *desc;
1272
1273                 desc = sb->disks + i;
1274                 if (desc->number || desc->major || desc->minor ||
1275                     desc->raid_disk || (desc->state && (desc->state != 4))) {
1276                         printk("     D %2d: ", i);
1277                         print_desc(desc);
1278                 }
1279         }
1280         printk(KERN_INFO "md:     THIS: ");
1281         print_desc(&sb->this_disk);
1282
1283 }
1284
1285 static void print_rdev(mdk_rdev_t *rdev)
1286 {
1287         char b[BDEVNAME_SIZE];
1288         printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
1289                 bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
1290                 rdev->faulty, rdev->in_sync, rdev->desc_nr);
1291         if (rdev->sb_loaded) {
1292                 printk(KERN_INFO "md: rdev superblock:\n");
1293                 print_sb((mdp_super_t*)page_address(rdev->sb_page));
1294         } else
1295                 printk(KERN_INFO "md: no rdev superblock!\n");
1296 }
1297
1298 void md_print_devices(void)
1299 {
1300         struct list_head *tmp, *tmp2;
1301         mdk_rdev_t *rdev;
1302         mddev_t *mddev;
1303         char b[BDEVNAME_SIZE];
1304
1305         printk("\n");
1306         printk("md:     **********************************\n");
1307         printk("md:     * <COMPLETE RAID STATE PRINTOUT> *\n");
1308         printk("md:     **********************************\n");
1309         ITERATE_MDDEV(mddev,tmp) {
1310
1311                 if (mddev->bitmap)
1312                         bitmap_print_sb(mddev->bitmap);
1313                 else
1314                         printk("%s: ", mdname(mddev));
1315                 ITERATE_RDEV(mddev,rdev,tmp2)
1316                         printk("<%s>", bdevname(rdev->bdev,b));
1317                 printk("\n");
1318
1319                 ITERATE_RDEV(mddev,rdev,tmp2)
1320                         print_rdev(rdev);
1321         }
1322         printk("md:     **********************************\n");
1323         printk("\n");
1324 }
1325
1326
1327 static void sync_sbs(mddev_t * mddev)
1328 {
1329         mdk_rdev_t *rdev;
1330         struct list_head *tmp;
1331
1332         ITERATE_RDEV(mddev,rdev,tmp) {
1333                 super_types[mddev->major_version].
1334                         sync_super(mddev, rdev);
1335                 rdev->sb_loaded = 1;
1336         }
1337 }
1338
1339 static void md_update_sb(mddev_t * mddev)
1340 {
1341         int err;
1342         struct list_head *tmp;
1343         mdk_rdev_t *rdev;
1344         int sync_req;
1345
1346 repeat:
1347         spin_lock(&mddev->write_lock);
1348         sync_req = mddev->in_sync;
1349         mddev->utime = get_seconds();
1350         mddev->events ++;
1351
1352         if (!mddev->events) {
1353                 /*
1354                  * oops, this 64-bit counter should never wrap.
1355                  * Either we are in around ~1 trillion A.C., assuming
1356                  * 1 reboot per second, or we have a bug:
1357                  */
1358                 MD_BUG();
1359                 mddev->events --;
1360         }
1361         mddev->sb_dirty = 2;
1362         sync_sbs(mddev);
1363
1364         /*
1365          * do not write anything to disk if using
1366          * nonpersistent superblocks
1367          */
1368         if (!mddev->persistent) {
1369                 mddev->sb_dirty = 0;
1370                 spin_unlock(&mddev->write_lock);
1371                 wake_up(&mddev->sb_wait);
1372                 return;
1373         }
1374         spin_unlock(&mddev->write_lock);
1375
1376         dprintk(KERN_INFO
1377                 "md: updating %s RAID superblock on device (in sync %d)\n",
1378                 mdname(mddev),mddev->in_sync);
1379
1380         err = bitmap_update_sb(mddev->bitmap);
1381         ITERATE_RDEV(mddev,rdev,tmp) {
1382                 char b[BDEVNAME_SIZE];
1383                 dprintk(KERN_INFO "md: ");
1384                 if (rdev->faulty)
1385                         dprintk("(skipping faulty ");
1386
1387                 dprintk("%s ", bdevname(rdev->bdev,b));
1388                 if (!rdev->faulty) {
1389                         md_super_write(mddev,rdev,
1390                                        rdev->sb_offset<<1, rdev->sb_size,
1391                                        rdev->sb_page);
1392                         dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
1393                                 bdevname(rdev->bdev,b),
1394                                 (unsigned long long)rdev->sb_offset);
1395
1396                 } else
1397                         dprintk(")\n");
1398                 if (mddev->level == LEVEL_MULTIPATH)
1399                         /* only need to write one superblock... */
1400                         break;
1401         }
1402         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
1403         /* if there was a failure, sb_dirty was set to 1, and we re-write super */
1404
1405         spin_lock(&mddev->write_lock);
1406         if (mddev->in_sync != sync_req|| mddev->sb_dirty == 1) {
1407                 /* have to write it out again */
1408                 spin_unlock(&mddev->write_lock);
1409                 goto repeat;
1410         }
1411         mddev->sb_dirty = 0;
1412         spin_unlock(&mddev->write_lock);
1413         wake_up(&mddev->sb_wait);
1414
1415 }
1416
1417 /*
1418  * Import a device. If 'super_format' >= 0, then sanity check the superblock
1419  *
1420  * mark the device faulty if:
1421  *
1422  *   - the device is nonexistent (zero size)
1423  *   - the device has no valid superblock
1424  *
1425  * a faulty rdev _never_ has rdev->sb set.
1426  */
1427 static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
1428 {
1429         char b[BDEVNAME_SIZE];
1430         int err;
1431         mdk_rdev_t *rdev;
1432         sector_t size;
1433
1434         rdev = (mdk_rdev_t *) kmalloc(sizeof(*rdev), GFP_KERNEL);
1435         if (!rdev) {
1436                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
1437                 return ERR_PTR(-ENOMEM);
1438         }
1439         memset(rdev, 0, sizeof(*rdev));
1440
1441         if ((err = alloc_disk_sb(rdev)))
1442                 goto abort_free;
1443
1444         err = lock_rdev(rdev, newdev);
1445         if (err)
1446                 goto abort_free;
1447
1448         rdev->desc_nr = -1;
1449         rdev->faulty = 0;
1450         rdev->in_sync = 0;
1451         rdev->data_offset = 0;
1452         atomic_set(&rdev->nr_pending, 0);
1453
1454         size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
1455         if (!size) {
1456                 printk(KERN_WARNING
1457                         "md: %s has zero or unknown size, marking faulty!\n",
1458                         bdevname(rdev->bdev,b));
1459                 err = -EINVAL;
1460                 goto abort_free;
1461         }
1462
1463         if (super_format >= 0) {
1464                 err = super_types[super_format].
1465                         load_super(rdev, NULL, super_minor);
1466                 if (err == -EINVAL) {
1467                         printk(KERN_WARNING
1468                                 "md: %s has invalid sb, not importing!\n",
1469                                 bdevname(rdev->bdev,b));
1470                         goto abort_free;
1471                 }
1472                 if (err < 0) {
1473                         printk(KERN_WARNING
1474                                 "md: could not read %s's sb, not importing!\n",
1475                                 bdevname(rdev->bdev,b));
1476                         goto abort_free;
1477                 }
1478         }
1479         INIT_LIST_HEAD(&rdev->same_set);
1480
1481         return rdev;
1482
1483 abort_free:
1484         if (rdev->sb_page) {
1485                 if (rdev->bdev)
1486                         unlock_rdev(rdev);
1487                 free_disk_sb(rdev);
1488         }
1489         kfree(rdev);
1490         return ERR_PTR(err);
1491 }
1492
1493 /*
1494  * Check a full RAID array for plausibility
1495  */
1496
1497
1498 static void analyze_sbs(mddev_t * mddev)
1499 {
1500         int i;
1501         struct list_head *tmp;
1502         mdk_rdev_t *rdev, *freshest;
1503         char b[BDEVNAME_SIZE];
1504
1505         freshest = NULL;
1506         ITERATE_RDEV(mddev,rdev,tmp)
1507                 switch (super_types[mddev->major_version].
1508                         load_super(rdev, freshest, mddev->minor_version)) {
1509                 case 1:
1510                         freshest = rdev;
1511                         break;
1512                 case 0:
1513                         break;
1514                 default:
1515                         printk( KERN_ERR \
1516                                 "md: fatal superblock inconsistency in %s"
1517                                 " -- removing from array\n",
1518                                 bdevname(rdev->bdev,b));
1519                         kick_rdev_from_array(rdev);
1520                 }
1521
1522
1523         super_types[mddev->major_version].
1524                 validate_super(mddev, freshest);
1525
1526         i = 0;
1527         ITERATE_RDEV(mddev,rdev,tmp) {
1528                 if (rdev != freshest)
1529                         if (super_types[mddev->major_version].
1530                             validate_super(mddev, rdev)) {
1531                                 printk(KERN_WARNING "md: kicking non-fresh %s"
1532                                         " from array!\n",
1533                                         bdevname(rdev->bdev,b));
1534                                 kick_rdev_from_array(rdev);
1535                                 continue;
1536                         }
1537                 if (mddev->level == LEVEL_MULTIPATH) {
1538                         rdev->desc_nr = i++;
1539                         rdev->raid_disk = rdev->desc_nr;
1540                         rdev->in_sync = 1;
1541                 }
1542         }
1543
1544
1545
1546         if (mddev->recovery_cp != MaxSector &&
1547             mddev->level >= 1)
1548                 printk(KERN_ERR "md: %s: raid array is not clean"
1549                        " -- starting background reconstruction\n",
1550                        mdname(mddev));
1551
1552 }
1553
1554 struct md_sysfs_entry {
1555         struct attribute attr;
1556         ssize_t (*show)(mddev_t *, char *);
1557         ssize_t (*store)(mddev_t *, const char *, size_t);
1558 };
1559
1560 static ssize_t
1561 md_show_level(mddev_t *mddev, char *page)
1562 {
1563         mdk_personality_t *p = mddev->pers;
1564         if (p == NULL)
1565                 return 0;
1566         if (mddev->level >= 0)
1567                 return sprintf(page, "RAID-%d\n", mddev->level);
1568         else
1569                 return sprintf(page, "%s\n", p->name);
1570 }
1571
1572 static struct md_sysfs_entry md_level = {
1573         .attr = {.name = "level", .mode = S_IRUGO },
1574         .show = md_show_level,
1575 };
1576
1577 static ssize_t
1578 md_show_rdisks(mddev_t *mddev, char *page)
1579 {
1580         return sprintf(page, "%d\n", mddev->raid_disks);
1581 }
1582
1583 static struct md_sysfs_entry md_raid_disks = {
1584         .attr = {.name = "raid_disks", .mode = S_IRUGO },
1585         .show = md_show_rdisks,
1586 };
1587
1588 static struct attribute *md_default_attrs[] = {
1589         &md_level.attr,
1590         &md_raid_disks.attr,
1591         NULL,
1592 };
1593
1594 static ssize_t
1595 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
1596 {
1597         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
1598         mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
1599
1600         if (!entry->show)
1601                 return -EIO;
1602         return entry->show(mddev, page);
1603 }
1604
1605 static ssize_t
1606 md_attr_store(struct kobject *kobj, struct attribute *attr,
1607               const char *page, size_t length)
1608 {
1609         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
1610         mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
1611
1612         if (!entry->store)
1613                 return -EIO;
1614         return entry->store(mddev, page, length);
1615 }
1616
1617 static void md_free(struct kobject *ko)
1618 {
1619         mddev_t *mddev = container_of(ko, mddev_t, kobj);
1620         kfree(mddev);
1621 }
1622
1623 static struct sysfs_ops md_sysfs_ops = {
1624         .show   = md_attr_show,
1625         .store  = md_attr_store,
1626 };
1627 static struct kobj_type md_ktype = {
1628         .release        = md_free,
1629         .sysfs_ops      = &md_sysfs_ops,
1630         .default_attrs  = md_default_attrs,
1631 };
1632
1633 int mdp_major = 0;
1634
1635 static struct kobject *md_probe(dev_t dev, int *part, void *data)
1636 {
1637         static DECLARE_MUTEX(disks_sem);
1638         mddev_t *mddev = mddev_find(dev);
1639         struct gendisk *disk;
1640         int partitioned = (MAJOR(dev) != MD_MAJOR);
1641         int shift = partitioned ? MdpMinorShift : 0;
1642         int unit = MINOR(dev) >> shift;
1643
1644         if (!mddev)
1645                 return NULL;
1646
1647         down(&disks_sem);
1648         if (mddev->gendisk) {
1649                 up(&disks_sem);
1650                 mddev_put(mddev);
1651                 return NULL;
1652         }
1653         disk = alloc_disk(1 << shift);
1654         if (!disk) {
1655                 up(&disks_sem);
1656                 mddev_put(mddev);
1657                 return NULL;
1658         }
1659         disk->major = MAJOR(dev);
1660         disk->first_minor = unit << shift;
1661         if (partitioned) {
1662                 sprintf(disk->disk_name, "md_d%d", unit);
1663                 sprintf(disk->devfs_name, "md/d%d", unit);
1664         } else {
1665                 sprintf(disk->disk_name, "md%d", unit);
1666                 sprintf(disk->devfs_name, "md/%d", unit);
1667         }
1668         disk->fops = &md_fops;
1669         disk->private_data = mddev;
1670         disk->queue = mddev->queue;
1671         add_disk(disk);
1672         mddev->gendisk = disk;
1673         up(&disks_sem);
1674         mddev->kobj.parent = kobject_get(&disk->kobj);
1675         mddev->kobj.k_name = NULL;
1676         snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
1677         mddev->kobj.ktype = &md_ktype;
1678         kobject_register(&mddev->kobj);
1679         return NULL;
1680 }
1681
1682 void md_wakeup_thread(mdk_thread_t *thread);
1683
1684 static void md_safemode_timeout(unsigned long data)
1685 {
1686         mddev_t *mddev = (mddev_t *) data;
1687
1688         mddev->safemode = 1;
1689         md_wakeup_thread(mddev->thread);
1690 }
1691
1692
1693 static int do_md_run(mddev_t * mddev)
1694 {
1695         int pnum, err;
1696         int chunk_size;
1697         struct list_head *tmp;
1698         mdk_rdev_t *rdev;
1699         struct gendisk *disk;
1700         char b[BDEVNAME_SIZE];
1701
1702         if (list_empty(&mddev->disks))
1703                 /* cannot run an array with no devices.. */
1704                 return -EINVAL;
1705
1706         if (mddev->pers)
1707                 return -EBUSY;
1708
1709         /*
1710          * Analyze all RAID superblock(s)
1711          */
1712         if (!mddev->raid_disks)
1713                 analyze_sbs(mddev);
1714
1715         chunk_size = mddev->chunk_size;
1716         pnum = level_to_pers(mddev->level);
1717
1718         if ((pnum != MULTIPATH) && (pnum != RAID1)) {
1719                 if (!chunk_size) {
1720                         /*
1721                          * 'default chunksize' in the old md code used to
1722                          * be PAGE_SIZE, baaad.
1723                          * we abort here to be on the safe side. We don't
1724                          * want to continue the bad practice.
1725                          */
1726                         printk(KERN_ERR
1727                                 "no chunksize specified, see 'man raidtab'\n");
1728                         return -EINVAL;
1729                 }
1730                 if (chunk_size > MAX_CHUNK_SIZE) {
1731                         printk(KERN_ERR "too big chunk_size: %d > %d\n",
1732                                 chunk_size, MAX_CHUNK_SIZE);
1733                         return -EINVAL;
1734                 }
1735                 /*
1736                  * chunk-size has to be a power of 2 and multiples of PAGE_SIZE
1737                  */
1738                 if ( (1 << ffz(~chunk_size)) != chunk_size) {
1739                         printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
1740                         return -EINVAL;
1741                 }
1742                 if (chunk_size < PAGE_SIZE) {
1743                         printk(KERN_ERR "too small chunk_size: %d < %ld\n",
1744                                 chunk_size, PAGE_SIZE);
1745                         return -EINVAL;
1746                 }
1747
1748                 /* devices must have minimum size of one chunk */
1749                 ITERATE_RDEV(mddev,rdev,tmp) {
1750                         if (rdev->faulty)
1751                                 continue;
1752                         if (rdev->size < chunk_size / 1024) {
1753                                 printk(KERN_WARNING
1754                                         "md: Dev %s smaller than chunk_size:"
1755                                         " %lluk < %dk\n",
1756                                         bdevname(rdev->bdev,b),
1757                                         (unsigned long long)rdev->size,
1758                                         chunk_size / 1024);
1759                                 return -EINVAL;
1760                         }
1761                 }
1762         }
1763
1764 #ifdef CONFIG_KMOD
1765         if (!pers[pnum])
1766         {
1767                 request_module("md-personality-%d", pnum);
1768         }
1769 #endif
1770
1771         /*
1772          * Drop all container device buffers, from now on
1773          * the only valid external interface is through the md
1774          * device.
1775          * Also find largest hardsector size
1776          */
1777         ITERATE_RDEV(mddev,rdev,tmp) {
1778                 if (rdev->faulty)
1779                         continue;
1780                 sync_blockdev(rdev->bdev);
1781                 invalidate_bdev(rdev->bdev, 0);
1782         }
1783
1784         md_probe(mddev->unit, NULL, NULL);
1785         disk = mddev->gendisk;
1786         if (!disk)
1787                 return -ENOMEM;
1788
1789         spin_lock(&pers_lock);
1790         if (!pers[pnum] || !try_module_get(pers[pnum]->owner)) {
1791                 spin_unlock(&pers_lock);
1792                 printk(KERN_WARNING "md: personality %d is not loaded!\n",
1793                        pnum);
1794                 return -EINVAL;
1795         }
1796
1797         mddev->pers = pers[pnum];
1798         spin_unlock(&pers_lock);
1799
1800         mddev->recovery = 0;
1801         mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
1802
1803         /* before we start the array running, initialise the bitmap */
1804         err = bitmap_create(mddev);
1805         if (err)
1806                 printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
1807                         mdname(mddev), err);
1808         else
1809                 err = mddev->pers->run(mddev);
1810         if (err) {
1811                 printk(KERN_ERR "md: pers->run() failed ...\n");
1812                 module_put(mddev->pers->owner);
1813                 mddev->pers = NULL;
1814                 bitmap_destroy(mddev);
1815                 return err;
1816         }
1817         atomic_set(&mddev->writes_pending,0);
1818         mddev->safemode = 0;
1819         mddev->safemode_timer.function = md_safemode_timeout;
1820         mddev->safemode_timer.data = (unsigned long) mddev;
1821         mddev->safemode_delay = (20 * HZ)/1000 +1; /* 20 msec delay */
1822         mddev->in_sync = 1;
1823
1824         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1825         md_wakeup_thread(mddev->thread);
1826
1827         if (mddev->sb_dirty)
1828                 md_update_sb(mddev);
1829
1830         set_capacity(disk, mddev->array_size<<1);
1831
1832         /* If we call blk_queue_make_request here, it will
1833          * re-initialise max_sectors etc which may have been
1834          * refined inside -> run.  So just set the bits we need to set.
1835          * Most initialisation happended when we called
1836          * blk_queue_make_request(..., md_fail_request)
1837          * earlier.
1838          */
1839         mddev->queue->queuedata = mddev;
1840         mddev->queue->make_request_fn = mddev->pers->make_request;
1841
1842         mddev->changed = 1;
1843         return 0;
1844 }
1845
1846 static int restart_array(mddev_t *mddev)
1847 {
1848         struct gendisk *disk = mddev->gendisk;
1849         int err;
1850
1851         /*
1852          * Complain if it has no devices
1853          */
1854         err = -ENXIO;
1855         if (list_empty(&mddev->disks))
1856                 goto out;
1857
1858         if (mddev->pers) {
1859                 err = -EBUSY;
1860                 if (!mddev->ro)
1861                         goto out;
1862
1863                 mddev->safemode = 0;
1864                 mddev->ro = 0;
1865                 set_disk_ro(disk, 0);
1866
1867                 printk(KERN_INFO "md: %s switched to read-write mode.\n",
1868                         mdname(mddev));
1869                 /*
1870                  * Kick recovery or resync if necessary
1871                  */
1872                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1873                 md_wakeup_thread(mddev->thread);
1874                 err = 0;
1875         } else {
1876                 printk(KERN_ERR "md: %s has no personality assigned.\n",
1877                         mdname(mddev));
1878                 err = -EINVAL;
1879         }
1880
1881 out:
1882         return err;
1883 }
1884
1885 static int do_md_stop(mddev_t * mddev, int ro)
1886 {
1887         int err = 0;
1888         struct gendisk *disk = mddev->gendisk;
1889
1890         if (mddev->pers) {
1891                 if (atomic_read(&mddev->active)>2) {
1892                         printk("md: %s still in use.\n",mdname(mddev));
1893                         return -EBUSY;
1894                 }
1895
1896                 if (mddev->sync_thread) {
1897                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1898                         md_unregister_thread(mddev->sync_thread);
1899                         mddev->sync_thread = NULL;
1900                 }
1901
1902                 del_timer_sync(&mddev->safemode_timer);
1903
1904                 invalidate_partition(disk, 0);
1905
1906                 if (ro) {
1907                         err  = -ENXIO;
1908                         if (mddev->ro)
1909                                 goto out;
1910                         mddev->ro = 1;
1911                 } else {
1912                         bitmap_flush(mddev);
1913                         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
1914                         if (mddev->ro)
1915                                 set_disk_ro(disk, 0);
1916                         blk_queue_make_request(mddev->queue, md_fail_request);
1917                         mddev->pers->stop(mddev);
1918                         module_put(mddev->pers->owner);
1919                         mddev->pers = NULL;
1920                         if (mddev->ro)
1921                                 mddev->ro = 0;
1922                 }
1923                 if (!mddev->in_sync) {
1924                         /* mark array as shutdown cleanly */
1925                         mddev->in_sync = 1;
1926                         md_update_sb(mddev);
1927                 }
1928                 if (ro)
1929                         set_disk_ro(disk, 1);
1930         }
1931
1932         bitmap_destroy(mddev);
1933         if (mddev->bitmap_file) {
1934                 atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
1935                 fput(mddev->bitmap_file);
1936                 mddev->bitmap_file = NULL;
1937         }
1938         mddev->bitmap_offset = 0;
1939
1940         /*
1941          * Free resources if final stop
1942          */
1943         if (!ro) {
1944                 struct gendisk *disk;
1945                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
1946
1947                 export_array(mddev);
1948
1949                 mddev->array_size = 0;
1950                 disk = mddev->gendisk;
1951                 if (disk)
1952                         set_capacity(disk, 0);
1953                 mddev->changed = 1;
1954         } else
1955                 printk(KERN_INFO "md: %s switched to read-only mode.\n",
1956                         mdname(mddev));
1957         err = 0;
1958 out:
1959         return err;
1960 }
1961
1962 static void autorun_array(mddev_t *mddev)
1963 {
1964         mdk_rdev_t *rdev;
1965         struct list_head *tmp;
1966         int err;
1967
1968         if (list_empty(&mddev->disks))
1969                 return;
1970
1971         printk(KERN_INFO "md: running: ");
1972
1973         ITERATE_RDEV(mddev,rdev,tmp) {
1974                 char b[BDEVNAME_SIZE];
1975                 printk("<%s>", bdevname(rdev->bdev,b));
1976         }
1977         printk("\n");
1978
1979         err = do_md_run (mddev);
1980         if (err) {
1981                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
1982                 do_md_stop (mddev, 0);
1983         }
1984 }
1985
1986 /*
1987  * lets try to run arrays based on all disks that have arrived
1988  * until now. (those are in pending_raid_disks)
1989  *
1990  * the method: pick the first pending disk, collect all disks with
1991  * the same UUID, remove all from the pending list and put them into
1992  * the 'same_array' list. Then order this list based on superblock
1993  * update time (freshest comes first), kick out 'old' disks and
1994  * compare superblocks. If everything's fine then run it.
1995  *
1996  * If "unit" is allocated, then bump its reference count
1997  */
1998 static void autorun_devices(int part)
1999 {
2000         struct list_head candidates;
2001         struct list_head *tmp;
2002         mdk_rdev_t *rdev0, *rdev;
2003         mddev_t *mddev;
2004         char b[BDEVNAME_SIZE];
2005
2006         printk(KERN_INFO "md: autorun ...\n");
2007         while (!list_empty(&pending_raid_disks)) {
2008                 dev_t dev;
2009                 rdev0 = list_entry(pending_raid_disks.next,
2010                                          mdk_rdev_t, same_set);
2011
2012                 printk(KERN_INFO "md: considering %s ...\n",
2013                         bdevname(rdev0->bdev,b));
2014                 INIT_LIST_HEAD(&candidates);
2015                 ITERATE_RDEV_PENDING(rdev,tmp)
2016                         if (super_90_load(rdev, rdev0, 0) >= 0) {
2017                                 printk(KERN_INFO "md:  adding %s ...\n",
2018                                         bdevname(rdev->bdev,b));
2019                                 list_move(&rdev->same_set, &candidates);
2020                         }
2021                 /*
2022                  * now we have a set of devices, with all of them having
2023                  * mostly sane superblocks. It's time to allocate the
2024                  * mddev.
2025                  */
2026                 if (rdev0->preferred_minor < 0 || rdev0->preferred_minor >= MAX_MD_DEVS) {
2027                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
2028                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
2029                         break;
2030                 }
2031                 if (part)
2032                         dev = MKDEV(mdp_major,
2033                                     rdev0->preferred_minor << MdpMinorShift);
2034                 else
2035                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
2036
2037                 md_probe(dev, NULL, NULL);
2038                 mddev = mddev_find(dev);
2039                 if (!mddev) {
2040                         printk(KERN_ERR
2041                                 "md: cannot allocate memory for md drive.\n");
2042                         break;
2043                 }
2044                 if (mddev_lock(mddev))
2045                         printk(KERN_WARNING "md: %s locked, cannot run\n",
2046                                mdname(mddev));
2047                 else if (mddev->raid_disks || mddev->major_version
2048                          || !list_empty(&mddev->disks)) {
2049                         printk(KERN_WARNING
2050                                 "md: %s already running, cannot run %s\n",
2051                                 mdname(mddev), bdevname(rdev0->bdev,b));
2052                         mddev_unlock(mddev);
2053                 } else {
2054                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
2055                         ITERATE_RDEV_GENERIC(candidates,rdev,tmp) {
2056                                 list_del_init(&rdev->same_set);
2057                                 if (bind_rdev_to_array(rdev, mddev))
2058                                         export_rdev(rdev);
2059                         }
2060                         autorun_array(mddev);
2061                         mddev_unlock(mddev);
2062                 }
2063                 /* on success, candidates will be empty, on error
2064                  * it won't...
2065                  */
2066                 ITERATE_RDEV_GENERIC(candidates,rdev,tmp)
2067                         export_rdev(rdev);
2068                 mddev_put(mddev);
2069         }
2070         printk(KERN_INFO "md: ... autorun DONE.\n");
2071 }
2072
2073 /*
2074  * import RAID devices based on one partition
2075  * if possible, the array gets run as well.
2076  */
2077
2078 static int autostart_array(dev_t startdev)
2079 {
2080         char b[BDEVNAME_SIZE];
2081         int err = -EINVAL, i;
2082         mdp_super_t *sb = NULL;
2083         mdk_rdev_t *start_rdev = NULL, *rdev;
2084
2085         start_rdev = md_import_device(startdev, 0, 0);
2086         if (IS_ERR(start_rdev))
2087                 return err;
2088
2089
2090         /* NOTE: this can only work for 0.90.0 superblocks */
2091         sb = (mdp_super_t*)page_address(start_rdev->sb_page);
2092         if (sb->major_version != 0 ||
2093             sb->minor_version != 90 ) {
2094                 printk(KERN_WARNING "md: can only autostart 0.90.0 arrays\n");
2095                 export_rdev(start_rdev);
2096                 return err;
2097         }
2098
2099         if (start_rdev->faulty) {
2100                 printk(KERN_WARNING
2101                         "md: can not autostart based on faulty %s!\n",
2102                         bdevname(start_rdev->bdev,b));
2103                 export_rdev(start_rdev);
2104                 return err;
2105         }
2106         list_add(&start_rdev->same_set, &pending_raid_disks);
2107
2108         for (i = 0; i < MD_SB_DISKS; i++) {
2109                 mdp_disk_t *desc = sb->disks + i;
2110                 dev_t dev = MKDEV(desc->major, desc->minor);
2111
2112                 if (!dev)
2113                         continue;
2114                 if (dev == startdev)
2115                         continue;
2116                 if (MAJOR(dev) != desc->major || MINOR(dev) != desc->minor)
2117                         continue;
2118                 rdev = md_import_device(dev, 0, 0);
2119                 if (IS_ERR(rdev))
2120                         continue;
2121
2122                 list_add(&rdev->same_set, &pending_raid_disks);
2123         }
2124
2125         /*
2126          * possibly return codes
2127          */
2128         autorun_devices(0);
2129         return 0;
2130
2131 }
2132
2133
2134 static int get_version(void __user * arg)
2135 {
2136         mdu_version_t ver;
2137
2138         ver.major = MD_MAJOR_VERSION;
2139         ver.minor = MD_MINOR_VERSION;
2140         ver.patchlevel = MD_PATCHLEVEL_VERSION;
2141
2142         if (copy_to_user(arg, &ver, sizeof(ver)))
2143                 return -EFAULT;
2144
2145         return 0;
2146 }
2147
2148 static int get_array_info(mddev_t * mddev, void __user * arg)
2149 {
2150         mdu_array_info_t info;
2151         int nr,working,active,failed,spare;
2152         mdk_rdev_t *rdev;
2153         struct list_head *tmp;
2154
2155         nr=working=active=failed=spare=0;
2156         ITERATE_RDEV(mddev,rdev,tmp) {
2157                 nr++;
2158                 if (rdev->faulty)
2159                         failed++;
2160                 else {
2161                         working++;
2162                         if (rdev->in_sync)
2163                                 active++;
2164                         else
2165                                 spare++;
2166                 }
2167         }
2168
2169         info.major_version = mddev->major_version;
2170         info.minor_version = mddev->minor_version;
2171         info.patch_version = MD_PATCHLEVEL_VERSION;
2172         info.ctime         = mddev->ctime;
2173         info.level         = mddev->level;
2174         info.size          = mddev->size;
2175         info.nr_disks      = nr;
2176         info.raid_disks    = mddev->raid_disks;
2177         info.md_minor      = mddev->md_minor;
2178         info.not_persistent= !mddev->persistent;
2179
2180         info.utime         = mddev->utime;
2181         info.state         = 0;
2182         if (mddev->in_sync)
2183                 info.state = (1<<MD_SB_CLEAN);
2184         if (mddev->bitmap && mddev->bitmap_offset)
2185                 info.state = (1<<MD_SB_BITMAP_PRESENT);
2186         info.active_disks  = active;
2187         info.working_disks = working;
2188         info.failed_disks  = failed;
2189         info.spare_disks   = spare;
2190
2191         info.layout        = mddev->layout;
2192         info.chunk_size    = mddev->chunk_size;
2193
2194         if (copy_to_user(arg, &info, sizeof(info)))
2195                 return -EFAULT;
2196
2197         return 0;
2198 }
2199
2200 static int get_bitmap_file(mddev_t * mddev, void __user * arg)
2201 {
2202         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
2203         char *ptr, *buf = NULL;
2204         int err = -ENOMEM;
2205
2206         file = kmalloc(sizeof(*file), GFP_KERNEL);
2207         if (!file)
2208                 goto out;
2209
2210         /* bitmap disabled, zero the first byte and copy out */
2211         if (!mddev->bitmap || !mddev->bitmap->file) {
2212                 file->pathname[0] = '\0';
2213                 goto copy_out;
2214         }
2215
2216         buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
2217         if (!buf)
2218                 goto out;
2219
2220         ptr = file_path(mddev->bitmap->file, buf, sizeof(file->pathname));
2221         if (!ptr)
2222                 goto out;
2223
2224         strcpy(file->pathname, ptr);
2225
2226 copy_out:
2227         err = 0;
2228         if (copy_to_user(arg, file, sizeof(*file)))
2229                 err = -EFAULT;
2230 out:
2231         kfree(buf);
2232         kfree(file);
2233         return err;
2234 }
2235
2236 static int get_disk_info(mddev_t * mddev, void __user * arg)
2237 {
2238         mdu_disk_info_t info;
2239         unsigned int nr;
2240         mdk_rdev_t *rdev;
2241
2242         if (copy_from_user(&info, arg, sizeof(info)))
2243                 return -EFAULT;
2244
2245         nr = info.number;
2246
2247         rdev = find_rdev_nr(mddev, nr);
2248         if (rdev) {
2249                 info.major = MAJOR(rdev->bdev->bd_dev);
2250                 info.minor = MINOR(rdev->bdev->bd_dev);
2251                 info.raid_disk = rdev->raid_disk;
2252                 info.state = 0;
2253                 if (rdev->faulty)
2254                         info.state |= (1<<MD_DISK_FAULTY);
2255                 else if (rdev->in_sync) {
2256                         info.state |= (1<<MD_DISK_ACTIVE);
2257                         info.state |= (1<<MD_DISK_SYNC);
2258                 }
2259                 if (test_bit(WriteMostly, &rdev->flags))
2260                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
2261         } else {
2262                 info.major = info.minor = 0;
2263                 info.raid_disk = -1;
2264                 info.state = (1<<MD_DISK_REMOVED);
2265         }
2266
2267         if (copy_to_user(arg, &info, sizeof(info)))
2268                 return -EFAULT;
2269
2270         return 0;
2271 }
2272
2273 static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
2274 {
2275         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
2276         mdk_rdev_t *rdev;
2277         dev_t dev = MKDEV(info->major,info->minor);
2278
2279         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
2280                 return -EOVERFLOW;
2281
2282         if (!mddev->raid_disks) {
2283                 int err;
2284                 /* expecting a device which has a superblock */
2285                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
2286                 if (IS_ERR(rdev)) {
2287                         printk(KERN_WARNING
2288                                 "md: md_import_device returned %ld\n",
2289                                 PTR_ERR(rdev));
2290                         return PTR_ERR(rdev);
2291                 }
2292                 if (!list_empty(&mddev->disks)) {
2293                         mdk_rdev_t *rdev0 = list_entry(mddev->disks.next,
2294                                                         mdk_rdev_t, same_set);
2295                         int err = super_types[mddev->major_version]
2296                                 .load_super(rdev, rdev0, mddev->minor_version);
2297                         if (err < 0) {
2298                                 printk(KERN_WARNING
2299                                         "md: %s has different UUID to %s\n",
2300                                         bdevname(rdev->bdev,b),
2301                                         bdevname(rdev0->bdev,b2));
2302                                 export_rdev(rdev);
2303                                 return -EINVAL;
2304                         }
2305                 }
2306                 err = bind_rdev_to_array(rdev, mddev);
2307                 if (err)
2308                         export_rdev(rdev);
2309                 return err;
2310         }
2311
2312         /*
2313          * add_new_disk can be used once the array is assembled
2314          * to add "hot spares".  They must already have a superblock
2315          * written
2316          */
2317         if (mddev->pers) {
2318                 int err;
2319                 if (!mddev->pers->hot_add_disk) {
2320                         printk(KERN_WARNING
2321                                 "%s: personality does not support diskops!\n",
2322                                mdname(mddev));
2323                         return -EINVAL;
2324                 }
2325                 if (mddev->persistent)
2326                         rdev = md_import_device(dev, mddev->major_version,
2327                                                 mddev->minor_version);
2328                 else
2329                         rdev = md_import_device(dev, -1, -1);
2330                 if (IS_ERR(rdev)) {
2331                         printk(KERN_WARNING
2332                                 "md: md_import_device returned %ld\n",
2333                                 PTR_ERR(rdev));
2334                         return PTR_ERR(rdev);
2335                 }
2336                 /* set save_raid_disk if appropriate */
2337                 if (!mddev->persistent) {
2338                         if (info->state & (1<<MD_DISK_SYNC)  &&
2339                             info->raid_disk < mddev->raid_disks)
2340                                 rdev->raid_disk = info->raid_disk;
2341                         else
2342                                 rdev->raid_disk = -1;
2343                 } else
2344                         super_types[mddev->major_version].
2345                                 validate_super(mddev, rdev);
2346                 rdev->saved_raid_disk = rdev->raid_disk;
2347
2348                 rdev->in_sync = 0; /* just to be sure */
2349                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
2350                         set_bit(WriteMostly, &rdev->flags);
2351
2352                 rdev->raid_disk = -1;
2353                 err = bind_rdev_to_array(rdev, mddev);
2354                 if (err)
2355                         export_rdev(rdev);
2356
2357                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2358                 md_wakeup_thread(mddev->thread);
2359                 return err;
2360         }
2361
2362         /* otherwise, add_new_disk is only allowed
2363          * for major_version==0 superblocks
2364          */
2365         if (mddev->major_version != 0) {
2366                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
2367                        mdname(mddev));
2368                 return -EINVAL;
2369         }
2370
2371         if (!(info->state & (1<<MD_DISK_FAULTY))) {
2372                 int err;
2373                 rdev = md_import_device (dev, -1, 0);
2374                 if (IS_ERR(rdev)) {
2375                         printk(KERN_WARNING
2376                                 "md: error, md_import_device() returned %ld\n",
2377                                 PTR_ERR(rdev));
2378                         return PTR_ERR(rdev);
2379                 }
2380                 rdev->desc_nr = info->number;
2381                 if (info->raid_disk < mddev->raid_disks)
2382                         rdev->raid_disk = info->raid_disk;
2383                 else
2384                         rdev->raid_disk = -1;
2385
2386                 rdev->faulty = 0;
2387                 if (rdev->raid_disk < mddev->raid_disks)
2388                         rdev->in_sync = (info->state & (1<<MD_DISK_SYNC));
2389                 else
2390                         rdev->in_sync = 0;
2391
2392                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
2393                         set_bit(WriteMostly, &rdev->flags);
2394
2395                 err = bind_rdev_to_array(rdev, mddev);
2396                 if (err) {
2397                         export_rdev(rdev);
2398                         return err;
2399                 }
2400
2401                 if (!mddev->persistent) {
2402                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
2403                         rdev->sb_offset = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2404                 } else
2405                         rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
2406                 rdev->size = calc_dev_size(rdev, mddev->chunk_size);
2407
2408                 if (!mddev->size || (mddev->size > rdev->size))
2409                         mddev->size = rdev->size;
2410         }
2411
2412         return 0;
2413 }
2414
2415 static int hot_remove_disk(mddev_t * mddev, dev_t dev)
2416 {
2417         char b[BDEVNAME_SIZE];
2418         mdk_rdev_t *rdev;
2419
2420         if (!mddev->pers)
2421                 return -ENODEV;
2422
2423         rdev = find_rdev(mddev, dev);
2424         if (!rdev)
2425                 return -ENXIO;
2426
2427         if (rdev->raid_disk >= 0)
2428                 goto busy;
2429
2430         kick_rdev_from_array(rdev);
2431         md_update_sb(mddev);
2432
2433         return 0;
2434 busy:
2435         printk(KERN_WARNING "md: cannot remove active disk %s from %s ... \n",
2436                 bdevname(rdev->bdev,b), mdname(mddev));
2437         return -EBUSY;
2438 }
2439
2440 static int hot_add_disk(mddev_t * mddev, dev_t dev)
2441 {
2442         char b[BDEVNAME_SIZE];
2443         int err;
2444         unsigned int size;
2445         mdk_rdev_t *rdev;
2446
2447         if (!mddev->pers)
2448                 return -ENODEV;
2449
2450         if (mddev->major_version != 0) {
2451                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
2452                         " version-0 superblocks.\n",
2453                         mdname(mddev));
2454                 return -EINVAL;
2455         }
2456         if (!mddev->pers->hot_add_disk) {
2457                 printk(KERN_WARNING
2458                         "%s: personality does not support diskops!\n",
2459                         mdname(mddev));
2460                 return -EINVAL;
2461         }
2462
2463         rdev = md_import_device (dev, -1, 0);
2464         if (IS_ERR(rdev)) {
2465                 printk(KERN_WARNING
2466                         "md: error, md_import_device() returned %ld\n",
2467                         PTR_ERR(rdev));
2468                 return -EINVAL;
2469         }
2470
2471         if (mddev->persistent)
2472                 rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
2473         else
2474                 rdev->sb_offset =
2475                         rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
2476
2477         size = calc_dev_size(rdev, mddev->chunk_size);
2478         rdev->size = size;
2479
2480         if (size < mddev->size) {
2481                 printk(KERN_WARNING
2482                         "%s: disk size %llu blocks < array size %llu\n",
2483                         mdname(mddev), (unsigned long long)size,
2484                         (unsigned long long)mddev->size);
2485                 err = -ENOSPC;
2486                 goto abort_export;
2487         }
2488
2489         if (rdev->faulty) {
2490                 printk(KERN_WARNING
2491                         "md: can not hot-add faulty %s disk to %s!\n",
2492                         bdevname(rdev->bdev,b), mdname(mddev));
2493                 err = -EINVAL;
2494                 goto abort_export;
2495         }
2496         rdev->in_sync = 0;
2497         rdev->desc_nr = -1;
2498         bind_rdev_to_array(rdev, mddev);
2499
2500         /*
2501          * The rest should better be atomic, we can have disk failures
2502          * noticed in interrupt contexts ...
2503          */
2504
2505         if (rdev->desc_nr == mddev->max_disks) {
2506                 printk(KERN_WARNING "%s: can not hot-add to full array!\n",
2507                         mdname(mddev));
2508                 err = -EBUSY;
2509                 goto abort_unbind_export;
2510         }
2511
2512         rdev->raid_disk = -1;
2513
2514         md_update_sb(mddev);
2515
2516         /*
2517          * Kick recovery, maybe this spare has to be added to the
2518          * array immediately.
2519          */
2520         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2521         md_wakeup_thread(mddev->thread);
2522
2523         return 0;
2524
2525 abort_unbind_export:
2526         unbind_rdev_from_array(rdev);
2527
2528 abort_export:
2529         export_rdev(rdev);
2530         return err;
2531 }
2532
2533 /* similar to deny_write_access, but accounts for our holding a reference
2534  * to the file ourselves */
2535 static int deny_bitmap_write_access(struct file * file)
2536 {
2537         struct inode *inode = file->f_mapping->host;
2538
2539         spin_lock(&inode->i_lock);
2540         if (atomic_read(&inode->i_writecount) > 1) {
2541                 spin_unlock(&inode->i_lock);
2542                 return -ETXTBSY;
2543         }
2544         atomic_set(&inode->i_writecount, -1);
2545         spin_unlock(&inode->i_lock);
2546
2547         return 0;
2548 }
2549
2550 static int set_bitmap_file(mddev_t *mddev, int fd)
2551 {
2552         int err;
2553
2554         if (mddev->pers) {
2555                 if (!mddev->pers->quiesce)
2556                         return -EBUSY;
2557                 if (mddev->recovery || mddev->sync_thread)
2558                         return -EBUSY;
2559                 /* we should be able to change the bitmap.. */
2560         }
2561
2562
2563         if (fd >= 0) {
2564                 if (mddev->bitmap)
2565                         return -EEXIST; /* cannot add when bitmap is present */
2566                 mddev->bitmap_file = fget(fd);
2567
2568                 if (mddev->bitmap_file == NULL) {
2569                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
2570                                mdname(mddev));
2571                         return -EBADF;
2572                 }
2573
2574                 err = deny_bitmap_write_access(mddev->bitmap_file);
2575                 if (err) {
2576                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
2577                                mdname(mddev));
2578                         fput(mddev->bitmap_file);
2579                         mddev->bitmap_file = NULL;
2580                         return err;
2581                 }
2582                 mddev->bitmap_offset = 0; /* file overrides offset */
2583         } else if (mddev->bitmap == NULL)
2584                 return -ENOENT; /* cannot remove what isn't there */
2585         err = 0;
2586         if (mddev->pers) {
2587                 mddev->pers->quiesce(mddev, 1);
2588                 if (fd >= 0)
2589                         err = bitmap_create(mddev);
2590                 if (fd < 0 || err)
2591                         bitmap_destroy(mddev);
2592                 mddev->pers->quiesce(mddev, 0);
2593         } else if (fd < 0) {
2594                 if (mddev->bitmap_file)
2595                         fput(mddev->bitmap_file);
2596                 mddev->bitmap_file = NULL;
2597         }
2598
2599         return err;
2600 }
2601
2602 /*
2603  * set_array_info is used two different ways
2604  * The original usage is when creating a new array.
2605  * In this usage, raid_disks is > 0 and it together with
2606  *  level, size, not_persistent,layout,chunksize determine the
2607  *  shape of the array.
2608  *  This will always create an array with a type-0.90.0 superblock.
2609  * The newer usage is when assembling an array.
2610  *  In this case raid_disks will be 0, and the major_version field is
2611  *  use to determine which style super-blocks are to be found on the devices.
2612  *  The minor and patch _version numbers are also kept incase the
2613  *  super_block handler wishes to interpret them.
2614  */
2615 static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
2616 {
2617
2618         if (info->raid_disks == 0) {
2619                 /* just setting version number for superblock loading */
2620                 if (info->major_version < 0 ||
2621                     info->major_version >= sizeof(super_types)/sizeof(super_types[0]) ||
2622                     super_types[info->major_version].name == NULL) {
2623                         /* maybe try to auto-load a module? */
2624                         printk(KERN_INFO
2625                                 "md: superblock version %d not known\n",
2626                                 info->major_version);
2627                         return -EINVAL;
2628                 }
2629                 mddev->major_version = info->major_version;
2630                 mddev->minor_version = info->minor_version;
2631                 mddev->patch_version = info->patch_version;
2632                 return 0;
2633         }
2634         mddev->major_version = MD_MAJOR_VERSION;
2635         mddev->minor_version = MD_MINOR_VERSION;
2636         mddev->patch_version = MD_PATCHLEVEL_VERSION;
2637         mddev->ctime         = get_seconds();
2638
2639         mddev->level         = info->level;
2640         mddev->size          = info->size;
2641         mddev->raid_disks    = info->raid_disks;
2642         /* don't set md_minor, it is determined by which /dev/md* was
2643          * openned
2644          */
2645         if (info->state & (1<<MD_SB_CLEAN))
2646                 mddev->recovery_cp = MaxSector;
2647         else
2648                 mddev->recovery_cp = 0;
2649         mddev->persistent    = ! info->not_persistent;
2650
2651         mddev->layout        = info->layout;
2652         mddev->chunk_size    = info->chunk_size;
2653
2654         mddev->max_disks     = MD_SB_DISKS;
2655
2656         mddev->sb_dirty      = 1;
2657
2658         /*
2659          * Generate a 128 bit UUID
2660          */
2661         get_random_bytes(mddev->uuid, 16);
2662
2663         return 0;
2664 }
2665
2666 /*
2667  * update_array_info is used to change the configuration of an
2668  * on-line array.
2669  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
2670  * fields in the info are checked against the array.
2671  * Any differences that cannot be handled will cause an error.
2672  * Normally, only one change can be managed at a time.
2673  */
2674 static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
2675 {
2676         int rv = 0;
2677         int cnt = 0;
2678         int state = 0;
2679
2680         /* calculate expected state,ignoring low bits */
2681         if (mddev->bitmap && mddev->bitmap_offset)
2682                 state |= (1 << MD_SB_BITMAP_PRESENT);
2683
2684         if (mddev->major_version != info->major_version ||
2685             mddev->minor_version != info->minor_version ||
2686 /*          mddev->patch_version != info->patch_version || */
2687             mddev->ctime         != info->ctime         ||
2688             mddev->level         != info->level         ||
2689 /*          mddev->layout        != info->layout        || */
2690             !mddev->persistent   != info->not_persistent||
2691             mddev->chunk_size    != info->chunk_size    ||
2692             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
2693             ((state^info->state) & 0xfffffe00)
2694                 )
2695                 return -EINVAL;
2696         /* Check there is only one change */
2697         if (mddev->size != info->size) cnt++;
2698         if (mddev->raid_disks != info->raid_disks) cnt++;
2699         if (mddev->layout != info->layout) cnt++;
2700         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
2701         if (cnt == 0) return 0;
2702         if (cnt > 1) return -EINVAL;
2703
2704         if (mddev->layout != info->layout) {
2705                 /* Change layout
2706                  * we don't need to do anything at the md level, the
2707                  * personality will take care of it all.
2708                  */
2709                 if (mddev->pers->reconfig == NULL)
2710                         return -EINVAL;
2711                 else
2712                         return mddev->pers->reconfig(mddev, info->layout, -1);
2713         }
2714         if (mddev->size != info->size) {
2715                 mdk_rdev_t * rdev;
2716                 struct list_head *tmp;
2717                 if (mddev->pers->resize == NULL)
2718                         return -EINVAL;
2719                 /* The "size" is the amount of each device that is used.
2720                  * This can only make sense for arrays with redundancy.
2721                  * linear and raid0 always use whatever space is available
2722                  * We can only consider changing the size if no resync
2723                  * or reconstruction is happening, and if the new size
2724                  * is acceptable. It must fit before the sb_offset or,
2725                  * if that is <data_offset, it must fit before the
2726                  * size of each device.
2727                  * If size is zero, we find the largest size that fits.
2728                  */
2729                 if (mddev->sync_thread)
2730                         return -EBUSY;
2731                 ITERATE_RDEV(mddev,rdev,tmp) {
2732                         sector_t avail;
2733                         int fit = (info->size == 0);
2734                         if (rdev->sb_offset > rdev->data_offset)
2735                                 avail = (rdev->sb_offset*2) - rdev->data_offset;
2736                         else
2737                                 avail = get_capacity(rdev->bdev->bd_disk)
2738                                         - rdev->data_offset;
2739                         if (fit && (info->size == 0 || info->size > avail/2))
2740                                 info->size = avail/2;
2741                         if (avail < ((sector_t)info->size << 1))
2742                                 return -ENOSPC;
2743                 }
2744                 rv = mddev->pers->resize(mddev, (sector_t)info->size *2);
2745                 if (!rv) {
2746                         struct block_device *bdev;
2747
2748                         bdev = bdget_disk(mddev->gendisk, 0);
2749                         if (bdev) {
2750                                 down(&bdev->bd_inode->i_sem);
2751                                 i_size_write(bdev->bd_inode, mddev->array_size << 10);
2752                                 up(&bdev->bd_inode->i_sem);
2753                                 bdput(bdev);
2754                         }
2755                 }
2756         }
2757         if (mddev->raid_disks    != info->raid_disks) {
2758                 /* change the number of raid disks */
2759                 if (mddev->pers->reshape == NULL)
2760                         return -EINVAL;
2761                 if (info->raid_disks <= 0 ||
2762                     info->raid_disks >= mddev->max_disks)
2763                         return -EINVAL;
2764                 if (mddev->sync_thread)
2765                         return -EBUSY;
2766                 rv = mddev->pers->reshape(mddev, info->raid_disks);
2767                 if (!rv) {
2768                         struct block_device *bdev;
2769
2770                         bdev = bdget_disk(mddev->gendisk, 0);
2771                         if (bdev) {
2772                                 down(&bdev->bd_inode->i_sem);
2773                                 i_size_write(bdev->bd_inode, mddev->array_size << 10);
2774                                 up(&bdev->bd_inode->i_sem);
2775                                 bdput(bdev);
2776                         }
2777                 }
2778         }
2779         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
2780                 if (mddev->pers->quiesce == NULL)
2781                         return -EINVAL;
2782                 if (mddev->recovery || mddev->sync_thread)
2783                         return -EBUSY;
2784                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
2785                         /* add the bitmap */
2786                         if (mddev->bitmap)
2787                                 return -EEXIST;
2788                         if (mddev->default_bitmap_offset == 0)
2789                                 return -EINVAL;
2790                         mddev->bitmap_offset = mddev->default_bitmap_offset;
2791                         mddev->pers->quiesce(mddev, 1);
2792                         rv = bitmap_create(mddev);
2793                         if (rv)
2794                                 bitmap_destroy(mddev);
2795                         mddev->pers->quiesce(mddev, 0);
2796                 } else {
2797                         /* remove the bitmap */
2798                         if (!mddev->bitmap)
2799                                 return -ENOENT;
2800                         if (mddev->bitmap->file)
2801                                 return -EINVAL;
2802                         mddev->pers->quiesce(mddev, 1);
2803                         bitmap_destroy(mddev);
2804                         mddev->pers->quiesce(mddev, 0);
2805                         mddev->bitmap_offset = 0;
2806                 }
2807         }
2808         md_update_sb(mddev);
2809         return rv;
2810 }
2811
2812 static int set_disk_faulty(mddev_t *mddev, dev_t dev)
2813 {
2814         mdk_rdev_t *rdev;
2815
2816         if (mddev->pers == NULL)
2817                 return -ENODEV;
2818
2819         rdev = find_rdev(mddev, dev);
2820         if (!rdev)
2821                 return -ENODEV;
2822
2823         md_error(mddev, rdev);
2824         return 0;
2825 }
2826
2827 static int md_ioctl(struct inode *inode, struct file *file,
2828                         unsigned int cmd, unsigned long arg)
2829 {
2830         int err = 0;
2831         void __user *argp = (void __user *)arg;
2832         struct hd_geometry __user *loc = argp;
2833         mddev_t *mddev = NULL;
2834
2835         if (!capable(CAP_SYS_ADMIN))
2836                 return -EACCES;
2837
2838         /*
2839          * Commands dealing with the RAID driver but not any
2840          * particular array:
2841          */
2842         switch (cmd)
2843         {
2844                 case RAID_VERSION:
2845                         err = get_version(argp);
2846                         goto done;
2847
2848                 case PRINT_RAID_DEBUG:
2849                         err = 0;
2850                         md_print_devices();
2851                         goto done;
2852
2853 #ifndef MODULE
2854                 case RAID_AUTORUN:
2855                         err = 0;
2856                         autostart_arrays(arg);
2857                         goto done;
2858 #endif
2859                 default:;
2860         }
2861
2862         /*
2863          * Commands creating/starting a new array:
2864          */
2865
2866         mddev = inode->i_bdev->bd_disk->private_data;
2867
2868         if (!mddev) {
2869                 BUG();
2870                 goto abort;
2871         }
2872
2873
2874         if (cmd == START_ARRAY) {
2875                 /* START_ARRAY doesn't need to lock the array as autostart_array
2876                  * does the locking, and it could even be a different array
2877                  */
2878                 static int cnt = 3;
2879                 if (cnt > 0 ) {
2880                         printk(KERN_WARNING
2881                                "md: %s(pid %d) used deprecated START_ARRAY ioctl. "
2882                                "This will not be supported beyond 2.6\n",
2883                                current->comm, current->pid);
2884                         cnt--;
2885                 }
2886                 err = autostart_array(new_decode_dev(arg));
2887                 if (err) {
2888                         printk(KERN_WARNING "md: autostart failed!\n");
2889                         goto abort;
2890                 }
2891                 goto done;
2892         }
2893
2894         err = mddev_lock(mddev);
2895         if (err) {
2896                 printk(KERN_INFO
2897                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
2898                         err, cmd);
2899                 goto abort;
2900         }
2901
2902         switch (cmd)
2903         {
2904                 case SET_ARRAY_INFO:
2905                         {
2906                                 mdu_array_info_t info;
2907                                 if (!arg)
2908                                         memset(&info, 0, sizeof(info));
2909                                 else if (copy_from_user(&info, argp, sizeof(info))) {
2910                                         err = -EFAULT;
2911                                         goto abort_unlock;
2912                                 }
2913                                 if (mddev->pers) {
2914                                         err = update_array_info(mddev, &info);
2915                                         if (err) {
2916                                                 printk(KERN_WARNING "md: couldn't update"
2917                                                        " array info. %d\n", err);
2918                                                 goto abort_unlock;
2919                                         }
2920                                         goto done_unlock;
2921                                 }
2922                                 if (!list_empty(&mddev->disks)) {
2923                                         printk(KERN_WARNING
2924                                                "md: array %s already has disks!\n",
2925                                                mdname(mddev));
2926                                         err = -EBUSY;
2927                                         goto abort_unlock;
2928                                 }
2929                                 if (mddev->raid_disks) {
2930                                         printk(KERN_WARNING
2931                                                "md: array %s already initialised!\n",
2932                                                mdname(mddev));
2933                                         err = -EBUSY;
2934                                         goto abort_unlock;
2935                                 }
2936                                 err = set_array_info(mddev, &info);
2937                                 if (err) {
2938                                         printk(KERN_WARNING "md: couldn't set"
2939                                                " array info. %d\n", err);
2940                                         goto abort_unlock;
2941                                 }
2942                         }
2943                         goto done_unlock;
2944
2945                 default:;
2946         }
2947
2948         /*
2949          * Commands querying/configuring an existing array:
2950          */
2951         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
2952          * RUN_ARRAY, and SET_BITMAP_FILE are allowed */
2953         if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
2954                         && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE) {
2955                 err = -ENODEV;
2956                 goto abort_unlock;
2957         }
2958
2959         /*
2960          * Commands even a read-only array can execute:
2961          */
2962         switch (cmd)
2963         {
2964                 case GET_ARRAY_INFO:
2965                         err = get_array_info(mddev, argp);
2966                         goto done_unlock;
2967
2968                 case GET_BITMAP_FILE:
2969                         err = get_bitmap_file(mddev, argp);
2970                         goto done_unlock;
2971
2972                 case GET_DISK_INFO:
2973                         err = get_disk_info(mddev, argp);
2974                         goto done_unlock;
2975
2976                 case RESTART_ARRAY_RW:
2977                         err = restart_array(mddev);
2978                         goto done_unlock;
2979
2980                 case STOP_ARRAY:
2981                         err = do_md_stop (mddev, 0);
2982                         goto done_unlock;
2983
2984                 case STOP_ARRAY_RO:
2985                         err = do_md_stop (mddev, 1);
2986                         goto done_unlock;
2987
2988         /*
2989          * We have a problem here : there is no easy way to give a CHS
2990          * virtual geometry. We currently pretend that we have a 2 heads
2991          * 4 sectors (with a BIG number of cylinders...). This drives
2992          * dosfs just mad... ;-)
2993          */
2994                 case HDIO_GETGEO:
2995                         if (!loc) {
2996                                 err = -EINVAL;
2997                                 goto abort_unlock;
2998                         }
2999                         err = put_user (2, (char __user *) &loc->heads);
3000                         if (err)
3001                                 goto abort_unlock;
3002                         err = put_user (4, (char __user *) &loc->sectors);
3003                         if (err)
3004                                 goto abort_unlock;
3005                         err = put_user(get_capacity(mddev->gendisk)/8,
3006                                         (short __user *) &loc->cylinders);
3007                         if (err)
3008                                 goto abort_unlock;
3009                         err = put_user (get_start_sect(inode->i_bdev),
3010                                                 (long __user *) &loc->start);
3011                         goto done_unlock;
3012         }
3013
3014         /*
3015          * The remaining ioctls are changing the state of the
3016          * superblock, so we do not allow read-only arrays
3017          * here:
3018          */
3019         if (mddev->ro) {
3020                 err = -EROFS;
3021                 goto abort_unlock;
3022         }
3023
3024         switch (cmd)
3025         {
3026                 case ADD_NEW_DISK:
3027                 {
3028                         mdu_disk_info_t info;
3029                         if (copy_from_user(&info, argp, sizeof(info)))
3030                                 err = -EFAULT;
3031                         else
3032                                 err = add_new_disk(mddev, &info);
3033                         goto done_unlock;
3034                 }
3035
3036                 case HOT_REMOVE_DISK:
3037                         err = hot_remove_disk(mddev, new_decode_dev(arg));
3038                         goto done_unlock;
3039
3040                 case HOT_ADD_DISK:
3041                         err = hot_add_disk(mddev, new_decode_dev(arg));
3042                         goto done_unlock;
3043
3044                 case SET_DISK_FAULTY:
3045                         err = set_disk_faulty(mddev, new_decode_dev(arg));
3046                         goto done_unlock;
3047
3048                 case RUN_ARRAY:
3049                         err = do_md_run (mddev);
3050                         goto done_unlock;
3051
3052                 case SET_BITMAP_FILE:
3053                         err = set_bitmap_file(mddev, (int)arg);
3054                         goto done_unlock;
3055
3056                 default:
3057                         if (_IOC_TYPE(cmd) == MD_MAJOR)
3058                                 printk(KERN_WARNING "md: %s(pid %d) used"
3059                                         " obsolete MD ioctl, upgrade your"
3060                                         " software to use new ictls.\n",
3061                                         current->comm, current->pid);
3062                         err = -EINVAL;
3063                         goto abort_unlock;
3064         }
3065
3066 done_unlock:
3067 abort_unlock:
3068         mddev_unlock(mddev);
3069
3070         return err;
3071 done:
3072         if (err)
3073                 MD_BUG();
3074 abort:
3075         return err;
3076 }
3077
3078 static int md_open(struct inode *inode, struct file *file)
3079 {
3080         /*
3081          * Succeed if we can lock the mddev, which confirms that
3082          * it isn't being stopped right now.
3083          */
3084         mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
3085         int err;
3086
3087         if ((err = mddev_lock(mddev)))
3088                 goto out;
3089
3090         err = 0;
3091         mddev_get(mddev);
3092         mddev_unlock(mddev);
3093
3094         check_disk_change(inode->i_bdev);
3095  out:
3096         return err;
3097 }
3098
3099 static int md_release(struct inode *inode, struct file * file)
3100 {
3101         mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
3102
3103         if (!mddev)
3104                 BUG();
3105         mddev_put(mddev);
3106
3107         return 0;
3108 }
3109
3110 static int md_media_changed(struct gendisk *disk)
3111 {
3112         mddev_t *mddev = disk->private_data;
3113
3114         return mddev->changed;
3115 }
3116
3117 static int md_revalidate(struct gendisk *disk)
3118 {
3119         mddev_t *mddev = disk->private_data;
3120
3121         mddev->changed = 0;
3122         return 0;
3123 }
3124 static struct block_device_operations md_fops =
3125 {
3126         .owner          = THIS_MODULE,
3127         .open           = md_open,
3128         .release        = md_release,
3129         .ioctl          = md_ioctl,
3130         .media_changed  = md_media_changed,
3131         .revalidate_disk= md_revalidate,
3132 };
3133
3134 static int md_thread(void * arg)
3135 {
3136         mdk_thread_t *thread = arg;
3137
3138         /*
3139          * md_thread is a 'system-thread', it's priority should be very
3140          * high. We avoid resource deadlocks individually in each
3141          * raid personality. (RAID5 does preallocation) We also use RR and
3142          * the very same RT priority as kswapd, thus we will never get
3143          * into a priority inversion deadlock.
3144          *
3145          * we definitely have to have equal or higher priority than
3146          * bdflush, otherwise bdflush will deadlock if there are too
3147          * many dirty RAID5 blocks.
3148          */
3149
3150         allow_signal(SIGKILL);
3151         complete(thread->event);
3152         while (!kthread_should_stop()) {
3153                 void (*run)(mddev_t *);
3154
3155                 wait_event_interruptible_timeout(thread->wqueue,
3156                                                  test_bit(THREAD_WAKEUP, &thread->flags)
3157                                                  || kthread_should_stop(),
3158                                                  thread->timeout);
3159                 try_to_freeze();
3160
3161                 clear_bit(THREAD_WAKEUP, &thread->flags);
3162
3163                 run = thread->run;
3164                 if (run)
3165                         run(thread->mddev);
3166         }
3167
3168         return 0;
3169 }
3170
3171 void md_wakeup_thread(mdk_thread_t *thread)
3172 {
3173         if (thread) {
3174                 dprintk("md: waking up MD thread %s.\n", thread->tsk->comm);
3175                 set_bit(THREAD_WAKEUP, &thread->flags);
3176                 wake_up(&thread->wqueue);
3177         }
3178 }
3179
3180 mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
3181                                  const char *name)
3182 {
3183         mdk_thread_t *thread;
3184         struct completion event;
3185
3186         thread = kmalloc(sizeof(mdk_thread_t), GFP_KERNEL);
3187         if (!thread)
3188                 return NULL;
3189
3190         memset(thread, 0, sizeof(mdk_thread_t));
3191         init_waitqueue_head(&thread->wqueue);
3192
3193         init_completion(&event);
3194         thread->event = &event;
3195         thread->run = run;
3196         thread->mddev = mddev;
3197         thread->name = name;
3198         thread->timeout = MAX_SCHEDULE_TIMEOUT;
3199         thread->tsk = kthread_run(md_thread, thread, name, mdname(thread->mddev));
3200         if (IS_ERR(thread->tsk)) {
3201                 kfree(thread);
3202                 return NULL;
3203         }
3204         wait_for_completion(&event);
3205         return thread;
3206 }
3207
3208 void md_unregister_thread(mdk_thread_t *thread)
3209 {
3210         dprintk("interrupting MD-thread pid %d\n", thread->tsk->pid);
3211
3212         kthread_stop(thread->tsk);
3213         kfree(thread);
3214 }
3215
3216 void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
3217 {
3218         if (!mddev) {
3219                 MD_BUG();
3220                 return;
3221         }
3222
3223         if (!rdev || rdev->faulty)
3224                 return;
3225 /*
3226         dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
3227                 mdname(mddev),
3228                 MAJOR(rdev->bdev->bd_dev), MINOR(rdev->bdev->bd_dev),
3229                 __builtin_return_address(0),__builtin_return_address(1),
3230                 __builtin_return_address(2),__builtin_return_address(3));
3231 */
3232         if (!mddev->pers->error_handler)
3233                 return;
3234         mddev->pers->error_handler(mddev,rdev);
3235         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3236         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3237         md_wakeup_thread(mddev->thread);
3238 }
3239
3240 /* seq_file implementation /proc/mdstat */
3241
3242 static void status_unused(struct seq_file *seq)
3243 {
3244         int i = 0;
3245         mdk_rdev_t *rdev;
3246         struct list_head *tmp;
3247
3248         seq_printf(seq, "unused devices: ");
3249
3250         ITERATE_RDEV_PENDING(rdev,tmp) {
3251                 char b[BDEVNAME_SIZE];
3252                 i++;
3253                 seq_printf(seq, "%s ",
3254                               bdevname(rdev->bdev,b));
3255         }
3256         if (!i)
3257                 seq_printf(seq, "<none>");
3258
3259         seq_printf(seq, "\n");
3260 }
3261
3262
3263 static void status_resync(struct seq_file *seq, mddev_t * mddev)
3264 {
3265         unsigned long max_blocks, resync, res, dt, db, rt;
3266
3267         resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
3268
3269         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3270                 max_blocks = mddev->resync_max_sectors >> 1;
3271         else
3272                 max_blocks = mddev->size;
3273
3274         /*
3275          * Should not happen.
3276          */
3277         if (!max_blocks) {
3278                 MD_BUG();
3279                 return;
3280         }
3281         res = (resync/1024)*1000/(max_blocks/1024 + 1);
3282         {
3283                 int i, x = res/50, y = 20-x;
3284                 seq_printf(seq, "[");
3285                 for (i = 0; i < x; i++)
3286                         seq_printf(seq, "=");
3287                 seq_printf(seq, ">");
3288                 for (i = 0; i < y; i++)
3289                         seq_printf(seq, ".");
3290                 seq_printf(seq, "] ");
3291         }
3292         seq_printf(seq, " %s =%3lu.%lu%% (%lu/%lu)",
3293                       (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
3294                        "resync" : "recovery"),
3295                       res/10, res % 10, resync, max_blocks);
3296
3297         /*
3298          * We do not want to overflow, so the order of operands and
3299          * the * 100 / 100 trick are important. We do a +1 to be
3300          * safe against division by zero. We only estimate anyway.
3301          *
3302          * dt: time from mark until now
3303          * db: blocks written from mark until now
3304          * rt: remaining time
3305          */
3306         dt = ((jiffies - mddev->resync_mark) / HZ);
3307         if (!dt) dt++;
3308         db = resync - (mddev->resync_mark_cnt/2);
3309         rt = (dt * ((max_blocks-resync) / (db/100+1)))/100;
3310
3311         seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
3312
3313         seq_printf(seq, " speed=%ldK/sec", db/dt);
3314 }
3315
3316 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
3317 {
3318         struct list_head *tmp;
3319         loff_t l = *pos;
3320         mddev_t *mddev;
3321
3322         if (l >= 0x10000)
3323                 return NULL;
3324         if (!l--)
3325                 /* header */
3326                 return (void*)1;
3327
3328         spin_lock(&all_mddevs_lock);
3329         list_for_each(tmp,&all_mddevs)
3330                 if (!l--) {
3331                         mddev = list_entry(tmp, mddev_t, all_mddevs);
3332                         mddev_get(mddev);
3333                         spin_unlock(&all_mddevs_lock);
3334                         return mddev;
3335                 }
3336         spin_unlock(&all_mddevs_lock);
3337         if (!l--)
3338                 return (void*)2;/* tail */
3339         return NULL;
3340 }
3341
3342 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3343 {
3344         struct list_head *tmp;
3345         mddev_t *next_mddev, *mddev = v;
3346
3347         ++*pos;
3348         if (v == (void*)2)
3349                 return NULL;
3350
3351         spin_lock(&all_mddevs_lock);
3352         if (v == (void*)1)
3353                 tmp = all_mddevs.next;
3354         else
3355                 tmp = mddev->all_mddevs.next;
3356         if (tmp != &all_mddevs)
3357                 next_mddev = mddev_get(list_entry(tmp,mddev_t,all_mddevs));
3358         else {
3359                 next_mddev = (void*)2;
3360                 *pos = 0x10000;
3361         }
3362         spin_unlock(&all_mddevs_lock);
3363
3364         if (v != (void*)1)
3365                 mddev_put(mddev);
3366         return next_mddev;
3367
3368 }
3369
3370 static void md_seq_stop(struct seq_file *seq, void *v)
3371 {
3372         mddev_t *mddev = v;
3373
3374         if (mddev && v != (void*)1 && v != (void*)2)
3375                 mddev_put(mddev);
3376 }
3377
3378 static int md_seq_show(struct seq_file *seq, void *v)
3379 {
3380         mddev_t *mddev = v;
3381         sector_t size;
3382         struct list_head *tmp2;
3383         mdk_rdev_t *rdev;
3384         int i;
3385         struct bitmap *bitmap;
3386
3387         if (v == (void*)1) {
3388                 seq_printf(seq, "Personalities : ");
3389                 spin_lock(&pers_lock);
3390                 for (i = 0; i < MAX_PERSONALITY; i++)
3391                         if (pers[i])
3392                                 seq_printf(seq, "[%s] ", pers[i]->name);
3393
3394                 spin_unlock(&pers_lock);
3395                 seq_printf(seq, "\n");
3396                 return 0;
3397         }
3398         if (v == (void*)2) {
3399                 status_unused(seq);
3400                 return 0;
3401         }
3402
3403         if (mddev_lock(mddev)!=0)
3404                 return -EINTR;
3405         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
3406                 seq_printf(seq, "%s : %sactive", mdname(mddev),
3407                                                 mddev->pers ? "" : "in");
3408                 if (mddev->pers) {
3409                         if (mddev->ro)
3410                                 seq_printf(seq, " (read-only)");
3411                         seq_printf(seq, " %s", mddev->pers->name);
3412                 }
3413
3414                 size = 0;
3415                 ITERATE_RDEV(mddev,rdev,tmp2) {
3416                         char b[BDEVNAME_SIZE];
3417                         seq_printf(seq, " %s[%d]",
3418                                 bdevname(rdev->bdev,b), rdev->desc_nr);
3419                         if (test_bit(WriteMostly, &rdev->flags))
3420                                 seq_printf(seq, "(W)");
3421                         if (rdev->faulty) {
3422                                 seq_printf(seq, "(F)");
3423                                 continue;
3424                         } else if (rdev->raid_disk < 0)
3425                                 seq_printf(seq, "(S)"); /* spare */
3426                         size += rdev->size;
3427                 }
3428
3429                 if (!list_empty(&mddev->disks)) {
3430                         if (mddev->pers)
3431                                 seq_printf(seq, "\n      %llu blocks",
3432                                         (unsigned long long)mddev->array_size);
3433                         else
3434                                 seq_printf(seq, "\n      %llu blocks",
3435                                         (unsigned long long)size);
3436                 }
3437                 if (mddev->persistent) {
3438                         if (mddev->major_version != 0 ||
3439                             mddev->minor_version != 90) {
3440                                 seq_printf(seq," super %d.%d",
3441                                            mddev->major_version,
3442                                            mddev->minor_version);
3443                         }
3444                 } else
3445                         seq_printf(seq, " super non-persistent");
3446
3447                 if (mddev->pers) {
3448                         mddev->pers->status (seq, mddev);
3449                         seq_printf(seq, "\n      ");
3450                         if (mddev->curr_resync > 2) {
3451                                 status_resync (seq, mddev);
3452                                 seq_printf(seq, "\n      ");
3453                         } else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
3454                                 seq_printf(seq, "       resync=DELAYED\n      ");
3455                 } else
3456                         seq_printf(seq, "\n       ");
3457
3458                 if ((bitmap = mddev->bitmap)) {
3459                         unsigned long chunk_kb;
3460                         unsigned long flags;
3461                         spin_lock_irqsave(&bitmap->lock, flags);
3462                         chunk_kb = bitmap->chunksize >> 10;
3463                         seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
3464                                 "%lu%s chunk",
3465                                 bitmap->pages - bitmap->missing_pages,
3466                                 bitmap->pages,
3467                                 (bitmap->pages - bitmap->missing_pages)
3468                                         << (PAGE_SHIFT - 10),
3469                                 chunk_kb ? chunk_kb : bitmap->chunksize,
3470                                 chunk_kb ? "KB" : "B");
3471                         if (bitmap->file) {
3472                                 seq_printf(seq, ", file: ");
3473                                 seq_path(seq, bitmap->file->f_vfsmnt,
3474                                          bitmap->file->f_dentry," \t\n");
3475                         }
3476
3477                         seq_printf(seq, "\n");
3478                         spin_unlock_irqrestore(&bitmap->lock, flags);
3479                 }
3480
3481                 seq_printf(seq, "\n");
3482         }
3483         mddev_unlock(mddev);
3484
3485         return 0;
3486 }
3487
3488 static struct seq_operations md_seq_ops = {
3489         .start  = md_seq_start,
3490         .next   = md_seq_next,
3491         .stop   = md_seq_stop,
3492         .show   = md_seq_show,
3493 };
3494
3495 static int md_seq_open(struct inode *inode, struct file *file)
3496 {
3497         int error;
3498
3499         error = seq_open(file, &md_seq_ops);
3500         return error;
3501 }
3502
3503 static struct file_operations md_seq_fops = {
3504         .open           = md_seq_open,
3505         .read           = seq_read,
3506         .llseek         = seq_lseek,
3507         .release        = seq_release,
3508 };
3509
3510 int register_md_personality(int pnum, mdk_personality_t *p)
3511 {
3512         if (pnum >= MAX_PERSONALITY) {
3513                 printk(KERN_ERR
3514                        "md: tried to install personality %s as nr %d, but max is %lu\n",
3515                        p->name, pnum, MAX_PERSONALITY-1);
3516                 return -EINVAL;
3517         }
3518
3519         spin_lock(&pers_lock);
3520         if (pers[pnum]) {
3521                 spin_unlock(&pers_lock);
3522                 return -EBUSY;
3523         }
3524
3525         pers[pnum] = p;
3526         printk(KERN_INFO "md: %s personality registered as nr %d\n", p->name, pnum);
3527         spin_unlock(&pers_lock);
3528         return 0;
3529 }
3530
3531 int unregister_md_personality(int pnum)
3532 {
3533         if (pnum >= MAX_PERSONALITY)
3534                 return -EINVAL;
3535
3536         printk(KERN_INFO "md: %s personality unregistered\n", pers[pnum]->name);
3537         spin_lock(&pers_lock);
3538         pers[pnum] = NULL;
3539         spin_unlock(&pers_lock);
3540         return 0;
3541 }
3542
3543 static int is_mddev_idle(mddev_t *mddev)
3544 {
3545         mdk_rdev_t * rdev;
3546         struct list_head *tmp;
3547         int idle;
3548         unsigned long curr_events;
3549
3550         idle = 1;
3551         ITERATE_RDEV(mddev,rdev,tmp) {
3552                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
3553                 curr_events = disk_stat_read(disk, sectors[0]) +
3554                                 disk_stat_read(disk, sectors[1]) -
3555                                 atomic_read(&disk->sync_io);
3556                 /* Allow some slack between valud of curr_events and last_events,
3557                  * as there are some uninteresting races.
3558                  * Note: the following is an unsigned comparison.
3559                  */
3560                 if ((curr_events - rdev->last_events + 32) > 64) {
3561                         rdev->last_events = curr_events;
3562                         idle = 0;
3563                 }
3564         }
3565         return idle;
3566 }
3567
3568 void md_done_sync(mddev_t *mddev, int blocks, int ok)
3569 {
3570         /* another "blocks" (512byte) blocks have been synced */
3571         atomic_sub(blocks, &mddev->recovery_active);
3572         wake_up(&mddev->recovery_wait);
3573         if (!ok) {
3574                 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
3575                 md_wakeup_thread(mddev->thread);
3576                 // stop recovery, signal do_sync ....
3577         }
3578 }
3579
3580
3581 /* md_write_start(mddev, bi)
3582  * If we need to update some array metadata (e.g. 'active' flag
3583  * in superblock) before writing, schedule a superblock update
3584  * and wait for it to complete.
3585  */
3586 void md_write_start(mddev_t *mddev, struct bio *bi)
3587 {
3588         if (bio_data_dir(bi) != WRITE)
3589                 return;
3590
3591         atomic_inc(&mddev->writes_pending);
3592         if (mddev->in_sync) {
3593                 spin_lock(&mddev->write_lock);
3594                 if (mddev->in_sync) {
3595                         mddev->in_sync = 0;
3596                         mddev->sb_dirty = 1;
3597                         md_wakeup_thread(mddev->thread);
3598                 }
3599                 spin_unlock(&mddev->write_lock);
3600         }
3601         wait_event(mddev->sb_wait, mddev->sb_dirty==0);
3602 }
3603
3604 void md_write_end(mddev_t *mddev)
3605 {
3606         if (atomic_dec_and_test(&mddev->writes_pending)) {
3607                 if (mddev->safemode == 2)
3608                         md_wakeup_thread(mddev->thread);
3609                 else
3610                         mod_timer(&mddev->safemode_timer, jiffies + mddev->safemode_delay);
3611         }
3612 }
3613
3614 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
3615
3616 #define SYNC_MARKS      10
3617 #define SYNC_MARK_STEP  (3*HZ)
3618 static void md_do_sync(mddev_t *mddev)
3619 {
3620         mddev_t *mddev2;
3621         unsigned int currspeed = 0,
3622                  window;
3623         sector_t max_sectors,j, io_sectors;
3624         unsigned long mark[SYNC_MARKS];
3625         sector_t mark_cnt[SYNC_MARKS];
3626         int last_mark,m;
3627         struct list_head *tmp;
3628         sector_t last_check;
3629         int skipped = 0;
3630
3631         /* just incase thread restarts... */
3632         if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
3633                 return;
3634
3635         /* we overload curr_resync somewhat here.
3636          * 0 == not engaged in resync at all
3637          * 2 == checking that there is no conflict with another sync
3638          * 1 == like 2, but have yielded to allow conflicting resync to
3639          *              commense
3640          * other == active in resync - this many blocks
3641          *
3642          * Before starting a resync we must have set curr_resync to
3643          * 2, and then checked that every "conflicting" array has curr_resync
3644          * less than ours.  When we find one that is the same or higher
3645          * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
3646          * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
3647          * This will mean we have to start checking from the beginning again.
3648          *
3649          */
3650
3651         do {
3652                 mddev->curr_resync = 2;
3653
3654         try_again:
3655                 if (signal_pending(current) ||
3656                     kthread_should_stop()) {
3657                         flush_signals(current);
3658                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3659                         goto skip;
3660                 }
3661                 ITERATE_MDDEV(mddev2,tmp) {
3662                         if (mddev2 == mddev)
3663                                 continue;
3664                         if (mddev2->curr_resync &&
3665                             match_mddev_units(mddev,mddev2)) {
3666                                 DEFINE_WAIT(wq);
3667                                 if (mddev < mddev2 && mddev->curr_resync == 2) {
3668                                         /* arbitrarily yield */
3669                                         mddev->curr_resync = 1;
3670                                         wake_up(&resync_wait);
3671                                 }
3672                                 if (mddev > mddev2 && mddev->curr_resync == 1)
3673                                         /* no need to wait here, we can wait the next
3674                                          * time 'round when curr_resync == 2
3675                                          */
3676                                         continue;
3677                                 prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
3678                                 if (!signal_pending(current) &&
3679                                     !kthread_should_stop() &&
3680                                     mddev2->curr_resync >= mddev->curr_resync) {
3681                                         printk(KERN_INFO "md: delaying resync of %s"
3682                                                " until %s has finished resync (they"
3683                                                " share one or more physical units)\n",
3684                                                mdname(mddev), mdname(mddev2));
3685                                         mddev_put(mddev2);
3686                                         schedule();
3687                                         finish_wait(&resync_wait, &wq);
3688                                         goto try_again;
3689                                 }
3690                                 finish_wait(&resync_wait, &wq);
3691                         }
3692                 }
3693         } while (mddev->curr_resync < 2);
3694
3695         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
3696                 /* resync follows the size requested by the personality,
3697                  * which defaults to physical size, but can be virtual size
3698                  */
3699                 max_sectors = mddev->resync_max_sectors;
3700         else
3701                 /* recovery follows the physical size of devices */
3702                 max_sectors = mddev->size << 1;
3703
3704         printk(KERN_INFO "md: syncing RAID array %s\n", mdname(mddev));
3705         printk(KERN_INFO "md: minimum _guaranteed_ reconstruction speed:"
3706                 " %d KB/sec/disc.\n", sysctl_speed_limit_min);
3707         printk(KERN_INFO "md: using maximum available idle IO bandwidth "
3708                "(but not more than %d KB/sec) for reconstruction.\n",
3709                sysctl_speed_limit_max);
3710
3711         is_mddev_idle(mddev); /* this also initializes IO event counters */
3712         /* we don't use the checkpoint if there's a bitmap */
3713         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && !mddev->bitmap)
3714                 j = mddev->recovery_cp;
3715         else
3716                 j = 0;
3717         io_sectors = 0;
3718         for (m = 0; m < SYNC_MARKS; m++) {
3719                 mark[m] = jiffies;
3720                 mark_cnt[m] = io_sectors;
3721         }
3722         last_mark = 0;
3723         mddev->resync_mark = mark[last_mark];
3724         mddev->resync_mark_cnt = mark_cnt[last_mark];
3725
3726         /*
3727          * Tune reconstruction:
3728          */
3729         window = 32*(PAGE_SIZE/512);
3730         printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
3731                 window/2,(unsigned long long) max_sectors/2);
3732
3733         atomic_set(&mddev->recovery_active, 0);
3734         init_waitqueue_head(&mddev->recovery_wait);
3735         last_check = 0;
3736
3737         if (j>2) {
3738                 printk(KERN_INFO
3739                         "md: resuming recovery of %s from checkpoint.\n",
3740                         mdname(mddev));
3741                 mddev->curr_resync = j;
3742         }
3743
3744         while (j < max_sectors) {
3745                 sector_t sectors;
3746
3747                 skipped = 0;
3748                 sectors = mddev->pers->sync_request(mddev, j, &skipped,
3749                                             currspeed < sysctl_speed_limit_min);
3750                 if (sectors == 0) {
3751                         set_bit(MD_RECOVERY_ERR, &mddev->recovery);
3752                         goto out;
3753                 }
3754
3755                 if (!skipped) { /* actual IO requested */
3756                         io_sectors += sectors;
3757                         atomic_add(sectors, &mddev->recovery_active);
3758                 }
3759
3760                 j += sectors;
3761                 if (j>1) mddev->curr_resync = j;
3762
3763
3764                 if (last_check + window > io_sectors || j == max_sectors)
3765                         continue;
3766
3767                 last_check = io_sectors;
3768
3769                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
3770                     test_bit(MD_RECOVERY_ERR, &mddev->recovery))
3771                         break;
3772
3773         repeat:
3774                 if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
3775                         /* step marks */
3776                         int next = (last_mark+1) % SYNC_MARKS;
3777
3778                         mddev->resync_mark = mark[next];
3779                         mddev->resync_mark_cnt = mark_cnt[next];
3780                         mark[next] = jiffies;
3781                         mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
3782                         last_mark = next;
3783                 }
3784
3785
3786                 if (signal_pending(current) || kthread_should_stop()) {
3787                         /*
3788                          * got a signal, exit.
3789                          */
3790                         printk(KERN_INFO
3791                                 "md: md_do_sync() got signal ... exiting\n");
3792                         flush_signals(current);
3793                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3794                         goto out;
3795                 }
3796
3797                 /*
3798                  * this loop exits only if either when we are slower than
3799                  * the 'hard' speed limit, or the system was IO-idle for
3800                  * a jiffy.
3801                  * the system might be non-idle CPU-wise, but we only care
3802                  * about not overloading the IO subsystem. (things like an
3803                  * e2fsck being done on the RAID array should execute fast)
3804                  */
3805                 mddev->queue->unplug_fn(mddev->queue);
3806                 cond_resched();
3807
3808                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
3809                         /((jiffies-mddev->resync_mark)/HZ +1) +1;
3810
3811                 if (currspeed > sysctl_speed_limit_min) {
3812                         if ((currspeed > sysctl_speed_limit_max) ||
3813                                         !is_mddev_idle(mddev)) {
3814                                 msleep_interruptible(250);
3815                                 goto repeat;
3816                         }
3817                 }
3818         }
3819         printk(KERN_INFO "md: %s: sync done.\n",mdname(mddev));
3820         /*
3821          * this also signals 'finished resyncing' to md_stop
3822          */
3823  out:
3824         mddev->queue->unplug_fn(mddev->queue);
3825
3826         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
3827
3828         /* tell personality that we are finished */
3829         mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
3830
3831         if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
3832             mddev->curr_resync > 2 &&
3833             mddev->curr_resync >= mddev->recovery_cp) {
3834                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
3835                         printk(KERN_INFO
3836                                 "md: checkpointing recovery of %s.\n",
3837                                 mdname(mddev));
3838                         mddev->recovery_cp = mddev->curr_resync;
3839                 } else
3840                         mddev->recovery_cp = MaxSector;
3841         }
3842
3843  skip:
3844         mddev->curr_resync = 0;
3845         wake_up(&resync_wait);
3846         set_bit(MD_RECOVERY_DONE, &mddev->recovery);
3847         md_wakeup_thread(mddev->thread);
3848 }
3849
3850
3851 /*
3852  * This routine is regularly called by all per-raid-array threads to
3853  * deal with generic issues like resync and super-block update.
3854  * Raid personalities that don't have a thread (linear/raid0) do not
3855  * need this as they never do any recovery or update the superblock.
3856  *
3857  * It does not do any resync itself, but rather "forks" off other threads
3858  * to do that as needed.
3859  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
3860  * "->recovery" and create a thread at ->sync_thread.
3861  * When the thread finishes it sets MD_RECOVERY_DONE (and might set MD_RECOVERY_ERR)
3862  * and wakeups up this thread which will reap the thread and finish up.
3863  * This thread also removes any faulty devices (with nr_pending == 0).
3864  *
3865  * The overall approach is:
3866  *  1/ if the superblock needs updating, update it.
3867  *  2/ If a recovery thread is running, don't do anything else.
3868  *  3/ If recovery has finished, clean up, possibly marking spares active.
3869  *  4/ If there are any faulty devices, remove them.
3870  *  5/ If array is degraded, try to add spares devices
3871  *  6/ If array has spares or is not in-sync, start a resync thread.
3872  */
3873 void md_check_recovery(mddev_t *mddev)
3874 {
3875         mdk_rdev_t *rdev;
3876         struct list_head *rtmp;
3877
3878
3879         if (mddev->bitmap)
3880                 bitmap_daemon_work(mddev->bitmap);
3881
3882         if (mddev->ro)
3883                 return;
3884
3885         if (signal_pending(current)) {
3886                 if (mddev->pers->sync_request) {
3887                         printk(KERN_INFO "md: %s in immediate safe mode\n",
3888                                mdname(mddev));
3889                         mddev->safemode = 2;
3890                 }
3891                 flush_signals(current);
3892         }
3893
3894         if ( ! (
3895                 mddev->sb_dirty ||
3896                 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
3897                 test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
3898                 (mddev->safemode == 1) ||
3899                 (mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
3900                  && !mddev->in_sync && mddev->recovery_cp == MaxSector)
3901                 ))
3902                 return;
3903
3904         if (mddev_trylock(mddev)==0) {
3905                 int spares =0;
3906
3907                 spin_lock(&mddev->write_lock);
3908                 if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
3909                     !mddev->in_sync && mddev->recovery_cp == MaxSector) {
3910                         mddev->in_sync = 1;
3911                         mddev->sb_dirty = 1;
3912                 }
3913                 if (mddev->safemode == 1)
3914                         mddev->safemode = 0;
3915                 spin_unlock(&mddev->write_lock);
3916
3917                 if (mddev->sb_dirty)
3918                         md_update_sb(mddev);
3919
3920
3921                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
3922                     !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
3923                         /* resync/recovery still happening */
3924                         clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3925                         goto unlock;
3926                 }
3927                 if (mddev->sync_thread) {
3928                         /* resync has finished, collect result */
3929                         md_unregister_thread(mddev->sync_thread);
3930                         mddev->sync_thread = NULL;
3931                         if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
3932                             !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
3933                                 /* success...*/
3934                                 /* activate any spares */
3935                                 mddev->pers->spare_active(mddev);
3936                         }
3937                         md_update_sb(mddev);
3938
3939                         /* if array is no-longer degraded, then any saved_raid_disk
3940                          * information must be scrapped
3941                          */
3942                         if (!mddev->degraded)
3943                                 ITERATE_RDEV(mddev,rdev,rtmp)
3944                                         rdev->saved_raid_disk = -1;
3945
3946                         mddev->recovery = 0;
3947                         /* flag recovery needed just to double check */
3948                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3949                         goto unlock;
3950                 }
3951                 if (mddev->recovery)
3952                         /* probably just the RECOVERY_NEEDED flag */
3953                         mddev->recovery = 0;
3954
3955                 /* no recovery is running.
3956                  * remove any failed drives, then
3957                  * add spares if possible.
3958                  * Spare are also removed and re-added, to allow
3959                  * the personality to fail the re-add.
3960                  */
3961                 ITERATE_RDEV(mddev,rdev,rtmp)
3962                         if (rdev->raid_disk >= 0 &&
3963                             (rdev->faulty || ! rdev->in_sync) &&
3964                             atomic_read(&rdev->nr_pending)==0) {
3965                                 if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0)
3966                                         rdev->raid_disk = -1;
3967                         }
3968
3969                 if (mddev->degraded) {
3970                         ITERATE_RDEV(mddev,rdev,rtmp)
3971                                 if (rdev->raid_disk < 0
3972                                     && !rdev->faulty) {
3973                                         if (mddev->pers->hot_add_disk(mddev,rdev))
3974                                                 spares++;
3975                                         else
3976                                                 break;
3977                                 }
3978                 }
3979
3980                 if (!spares && (mddev->recovery_cp == MaxSector )) {
3981                         /* nothing we can do ... */
3982                         goto unlock;
3983                 }
3984                 if (mddev->pers->sync_request) {
3985                         set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3986                         if (!spares)
3987                                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3988                         if (spares && mddev->bitmap && ! mddev->bitmap->file) {
3989                                 /* We are adding a device or devices to an array
3990                                  * which has the bitmap stored on all devices.
3991                                  * So make sure all bitmap pages get written
3992                                  */
3993                                 bitmap_write_all(mddev->bitmap);
3994                         }
3995                         mddev->sync_thread = md_register_thread(md_do_sync,
3996                                                                 mddev,
3997                                                                 "%s_resync");
3998                         if (!mddev->sync_thread) {
3999                                 printk(KERN_ERR "%s: could not start resync"
4000                                         " thread...\n",
4001                                         mdname(mddev));
4002                                 /* leave the spares where they are, it shouldn't hurt */
4003                                 mddev->recovery = 0;
4004                         } else {
4005                                 md_wakeup_thread(mddev->sync_thread);
4006                         }
4007                 }
4008         unlock:
4009                 mddev_unlock(mddev);
4010         }
4011 }
4012
4013 static int md_notify_reboot(struct notifier_block *this,
4014                             unsigned long code, void *x)
4015 {
4016         struct list_head *tmp;
4017         mddev_t *mddev;
4018
4019         if ((code == SYS_DOWN) || (code == SYS_HALT) || (code == SYS_POWER_OFF)) {
4020
4021                 printk(KERN_INFO "md: stopping all md devices.\n");
4022
4023                 ITERATE_MDDEV(mddev,tmp)
4024                         if (mddev_trylock(mddev)==0)
4025                                 do_md_stop (mddev, 1);
4026                 /*
4027                  * certain more exotic SCSI devices are known to be
4028                  * volatile wrt too early system reboots. While the
4029                  * right place to handle this issue is the given
4030                  * driver, we do want to have a safe RAID driver ...
4031                  */
4032                 mdelay(1000*1);
4033         }
4034         return NOTIFY_DONE;
4035 }
4036
4037 static struct notifier_block md_notifier = {
4038         .notifier_call  = md_notify_reboot,
4039         .next           = NULL,
4040         .priority       = INT_MAX, /* before any real devices */
4041 };
4042
4043 static void md_geninit(void)
4044 {
4045         struct proc_dir_entry *p;
4046
4047         dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
4048
4049         p = create_proc_entry("mdstat", S_IRUGO, NULL);
4050         if (p)
4051                 p->proc_fops = &md_seq_fops;
4052 }
4053
4054 static int __init md_init(void)
4055 {
4056         int minor;
4057
4058         printk(KERN_INFO "md: md driver %d.%d.%d MAX_MD_DEVS=%d,"
4059                         " MD_SB_DISKS=%d\n",
4060                         MD_MAJOR_VERSION, MD_MINOR_VERSION,
4061                         MD_PATCHLEVEL_VERSION, MAX_MD_DEVS, MD_SB_DISKS);
4062         printk(KERN_INFO "md: bitmap version %d.%d\n", BITMAP_MAJOR,
4063                         BITMAP_MINOR);
4064
4065         if (register_blkdev(MAJOR_NR, "md"))
4066                 return -1;
4067         if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
4068                 unregister_blkdev(MAJOR_NR, "md");
4069                 return -1;
4070         }
4071         devfs_mk_dir("md");
4072         blk_register_region(MKDEV(MAJOR_NR, 0), MAX_MD_DEVS, THIS_MODULE,
4073                                 md_probe, NULL, NULL);
4074         blk_register_region(MKDEV(mdp_major, 0), MAX_MD_DEVS<<MdpMinorShift, THIS_MODULE,
4075                             md_probe, NULL, NULL);
4076
4077         for (minor=0; minor < MAX_MD_DEVS; ++minor)
4078                 devfs_mk_bdev(MKDEV(MAJOR_NR, minor),
4079                                 S_IFBLK|S_IRUSR|S_IWUSR,
4080                                 "md/%d", minor);
4081
4082         for (minor=0; minor < MAX_MD_DEVS; ++minor)
4083                 devfs_mk_bdev(MKDEV(mdp_major, minor<<MdpMinorShift),
4084                               S_IFBLK|S_IRUSR|S_IWUSR,
4085                               "md/mdp%d", minor);
4086
4087
4088         register_reboot_notifier(&md_notifier);
4089         raid_table_header = register_sysctl_table(raid_root_table, 1);
4090
4091         md_geninit();
4092         return (0);
4093 }
4094
4095
4096 #ifndef MODULE
4097
4098 /*
4099  * Searches all registered partitions for autorun RAID arrays
4100  * at boot time.
4101  */
4102 static dev_t detected_devices[128];
4103 static int dev_cnt;
4104
4105 void md_autodetect_dev(dev_t dev)
4106 {
4107         if (dev_cnt >= 0 && dev_cnt < 127)
4108                 detected_devices[dev_cnt++] = dev;
4109 }
4110
4111
4112 static void autostart_arrays(int part)
4113 {
4114         mdk_rdev_t *rdev;
4115         int i;
4116
4117         printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
4118
4119         for (i = 0; i < dev_cnt; i++) {
4120                 dev_t dev = detected_devices[i];
4121
4122                 rdev = md_import_device(dev,0, 0);
4123                 if (IS_ERR(rdev))
4124                         continue;
4125
4126                 if (rdev->faulty) {
4127                         MD_BUG();
4128                         continue;
4129                 }
4130                 list_add(&rdev->same_set, &pending_raid_disks);
4131         }
4132         dev_cnt = 0;
4133
4134         autorun_devices(part);
4135 }
4136
4137 #endif
4138
4139 static __exit void md_exit(void)
4140 {
4141         mddev_t *mddev;
4142         struct list_head *tmp;
4143         int i;
4144         blk_unregister_region(MKDEV(MAJOR_NR,0), MAX_MD_DEVS);
4145         blk_unregister_region(MKDEV(mdp_major,0), MAX_MD_DEVS << MdpMinorShift);
4146         for (i=0; i < MAX_MD_DEVS; i++)
4147                 devfs_remove("md/%d", i);
4148         for (i=0; i < MAX_MD_DEVS; i++)
4149                 devfs_remove("md/d%d", i);
4150
4151         devfs_remove("md");
4152
4153         unregister_blkdev(MAJOR_NR,"md");
4154         unregister_blkdev(mdp_major, "mdp");
4155         unregister_reboot_notifier(&md_notifier);
4156         unregister_sysctl_table(raid_table_header);
4157         remove_proc_entry("mdstat", NULL);
4158         ITERATE_MDDEV(mddev,tmp) {
4159                 struct gendisk *disk = mddev->gendisk;
4160                 if (!disk)
4161                         continue;
4162                 export_array(mddev);
4163                 del_gendisk(disk);
4164                 put_disk(disk);
4165                 mddev->gendisk = NULL;
4166                 mddev_put(mddev);
4167         }
4168 }
4169
4170 module_init(md_init)
4171 module_exit(md_exit)
4172
4173 EXPORT_SYMBOL(register_md_personality);
4174 EXPORT_SYMBOL(unregister_md_personality);
4175 EXPORT_SYMBOL(md_error);
4176 EXPORT_SYMBOL(md_done_sync);
4177 EXPORT_SYMBOL(md_write_start);
4178 EXPORT_SYMBOL(md_write_end);
4179 EXPORT_SYMBOL(md_register_thread);
4180 EXPORT_SYMBOL(md_unregister_thread);
4181 EXPORT_SYMBOL(md_wakeup_thread);
4182 EXPORT_SYMBOL(md_print_devices);
4183 EXPORT_SYMBOL(md_check_recovery);
4184 MODULE_LICENSE("GPL");
4185 MODULE_ALIAS("md");
4186 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);