sys/vfs/hammer/hammer_subs.c

   1 /*
   2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/vfs/hammer/hammer_subs.c,v 1.35 2008/10/15 22:38:37 dillon Exp $
  35  */
  36 /*
  37  * HAMMER structural locking
  38  */
  39
  40 #include "hammer.h"
  41 #include <sys/dirent.h>
  42
  43 void
  44 hammer_lock_ex_ident(struct hammer_lock *lock, const char *ident)
  45 {
  46         thread_t td = curthread;
  47
  48         KKASSERT(lock->refs > 0);
  49         crit_enter();
  50         if (lock->locktd != td) {
  51                 while (lock->locktd != NULL || lock->lockcount) {
  52                         ++lock->exwanted;
  53                         lock->wanted = 1;
  54                         if (hammer_debug_locks) {
  55                                 kprintf("hammer_lock_ex: held by %p\n",
  56                                         lock->locktd);
  57                         }
  58                         ++hammer_contention_count;
  59                         tsleep(lock, 0, ident, 0);
  60                         if (hammer_debug_locks)
  61                                 kprintf("hammer_lock_ex: try again\n");
  62                         --lock->exwanted;
  63                 }
  64                 lock->locktd = td;
  65         }
  66         KKASSERT(lock->lockcount >= 0);
  67         ++lock->lockcount;
  68         crit_exit();
  69 }
  70
  71 /*
  72  * Try to obtain an exclusive lock
  73  */
  74 int
  75 hammer_lock_ex_try(struct hammer_lock *lock)
  76 {
  77         thread_t td = curthread;
  78
  79         KKASSERT(lock->refs > 0);
  80         crit_enter();
  81         if (lock->locktd != td) {
  82                 if (lock->locktd != NULL || lock->lockcount) {
  83                         crit_exit();
  84                         return(EAGAIN);
  85                 }
  86                 lock->locktd = td;
  87         }
  88         KKASSERT(lock->lockcount >= 0);
  89         ++lock->lockcount;
  90         crit_exit();
  91         return(0);
  92 }
  93
  94 /*
  95  * Obtain a shared lock
  96  *
  97  * We do not give pending exclusive locks priority over shared locks as
  98  * doing so could lead to a deadlock.
  99  */
 100 void
 101 hammer_lock_sh(struct hammer_lock *lock)
 102 {
 103         KKASSERT(lock->refs > 0);
 104         crit_enter();
 105         while (lock->locktd != NULL) {
 106                 if (lock->locktd == curthread) {
 107                         Debugger("hammer_lock_sh: lock_sh on exclusive");
 108                         ++lock->lockcount;
 109                         crit_exit();
 110                         return;
 111                 }
 112                 lock->wanted = 1;
 113                 tsleep(lock, 0, "hmrlck", 0);
 114         }
 115         KKASSERT(lock->lockcount <= 0);
 116         --lock->lockcount;
 117         crit_exit();
 118 }
 119
 120 int
 121 hammer_lock_sh_try(struct hammer_lock *lock)
 122 {
 123         KKASSERT(lock->refs > 0);
 124         crit_enter();
 125         if (lock->locktd) {
 126                 crit_exit();
 127                 return(EAGAIN);
 128         }
 129         KKASSERT(lock->lockcount <= 0);
 130         --lock->lockcount;
 131         crit_exit();
 132         return(0);
 133 }
 134
 135 /*
 136  * Upgrade a shared lock to an exclusively held lock.  This function will
 137  * return EDEADLK If there is more then one shared holder.
 138  *
 139  * No error occurs and no action is taken if the lock is already exclusively
 140  * held by the caller.  If the lock is not held at all or held exclusively
 141  * by someone else, this function will panic.
 142  */
 143 int
 144 hammer_lock_upgrade(struct hammer_lock *lock)
 145 {
 146         int error;
 147
 148         crit_enter();
 149         if (lock->lockcount > 0) {
 150                 if (lock->locktd != curthread)
 151                         panic("hammer_lock_upgrade: illegal lock state");
 152                 error = 0;
 153         } else if (lock->lockcount == -1) {
 154                 lock->lockcount = 1;
 155                 lock->locktd = curthread;
 156                 error = 0;
 157         } else if (lock->lockcount != 0) {
 158                 error = EDEADLK;
 159         } else {
 160                 panic("hammer_lock_upgrade: lock is not held");
 161                 /* NOT REACHED */
 162                 error = 0;
 163         }
 164         crit_exit();
 165         return(error);
 166 }
 167
 168 /*
 169  * Downgrade an exclusively held lock to a shared lock.
 170  */
 171 void
 172 hammer_lock_downgrade(struct hammer_lock *lock)
 173 {
 174         KKASSERT(lock->lockcount == 1 && lock->locktd == curthread);
 175         crit_enter();
 176         lock->lockcount = -1;
 177         lock->locktd = NULL;
 178         if (lock->wanted) {
 179                 lock->wanted = 0;
 180                 wakeup(lock);
 181         }
 182         crit_exit();
 183         /* XXX memory barrier */
 184 }
 185
 186 void
 187 hammer_unlock(struct hammer_lock *lock)
 188 {
 189         crit_enter();
 190         KKASSERT(lock->lockcount != 0);
 191         if (lock->lockcount < 0) {
 192                 if (++lock->lockcount == 0 && lock->wanted) {
 193                         lock->wanted = 0;
 194                         wakeup(lock);
 195                 }
 196         } else {
 197                 KKASSERT(lock->locktd == curthread);
 198                 if (--lock->lockcount == 0) {
 199                         lock->locktd = NULL;
 200                         if (lock->wanted) {
 201                                 lock->wanted = 0;
 202                                 wakeup(lock);
 203                         }
 204                 }
 205
 206         }
 207         crit_exit();
 208 }
 209
 210 /*
 211  * The calling thread must be holding a shared or exclusive lock.
 212  * Returns < 0 if lock is held shared, and > 0 if held exlusively.
 213  */
 214 int
 215 hammer_lock_status(struct hammer_lock *lock)
 216 {
 217         if (lock->lockcount < 0)
 218                 return(-1);
 219         if (lock->lockcount > 0)
 220                 return(1);
 221         panic("hammer_lock_status: lock must be held: %p", lock);
 222 }
 223
 224 void
 225 hammer_ref(struct hammer_lock *lock)
 226 {
 227         KKASSERT(lock->refs >= 0);
 228         crit_enter();
 229         ++lock->refs;
 230         crit_exit();
 231 }
 232
 233 void
 234 hammer_unref(struct hammer_lock *lock)
 235 {
 236         KKASSERT(lock->refs > 0);
 237         crit_enter();
 238         --lock->refs;
 239         crit_exit();
 240 }
 241
 242 /*
 243  * The sync_lock must be held when doing any modifying operations on
 244  * meta-data.  It does not have to be held when modifying non-meta-data buffers
 245  * (backend or frontend).
 246  *
 247  * The flusher holds the lock exclusively while all other consumers hold it
 248  * shared.  All modifying operations made while holding the lock are atomic
 249  * in that they will be made part of the same flush group.
 250  *
 251  * Due to the atomicy requirement deadlock recovery code CANNOT release the
 252  * sync lock, nor can we give pending exclusive sync locks priority over
 253  * a shared sync lock as this could lead to a 3-way deadlock.
 254  */
 255 void
 256 hammer_sync_lock_ex(hammer_transaction_t trans)
 257 {
 258         ++trans->sync_lock_refs;
 259         hammer_lock_ex(&trans->hmp->sync_lock);
 260 }
 261
 262 void
 263 hammer_sync_lock_sh(hammer_transaction_t trans)
 264 {
 265         ++trans->sync_lock_refs;
 266         hammer_lock_sh(&trans->hmp->sync_lock);
 267 }
 268
 269 int
 270 hammer_sync_lock_sh_try(hammer_transaction_t trans)
 271 {
 272         int error;
 273
 274         ++trans->sync_lock_refs;
 275         if ((error = hammer_lock_sh_try(&trans->hmp->sync_lock)) != 0)
 276                 --trans->sync_lock_refs;
 277         return (error);
 278 }
 279
 280 void
 281 hammer_sync_unlock(hammer_transaction_t trans)
 282 {
 283         --trans->sync_lock_refs;
 284         hammer_unlock(&trans->hmp->sync_lock);
 285 }
 286
 287 /*
 288  * Misc
 289  */
 290 u_int32_t
 291 hammer_to_unix_xid(uuid_t *uuid)
 292 {
 293         return(*(u_int32_t *)&uuid->node[2]);
 294 }
 295
 296 void
 297 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 298 {
 299         bzero(uuid, sizeof(*uuid));
 300         *(u_int32_t *)&uuid->node[2] = guid;
 301 }
 302
 303 void
 304 hammer_time_to_timespec(u_int64_t xtime, struct timespec *ts)
 305 {
 306         ts->tv_sec = (unsigned long)(xtime / 1000000);
 307         ts->tv_nsec = (unsigned int)(xtime % 1000000) * 1000L;
 308 }
 309
 310 u_int64_t
 311 hammer_timespec_to_time(struct timespec *ts)
 312 {
 313         u_int64_t xtime;
 314
 315         xtime = (unsigned)(ts->tv_nsec / 1000) +
 316                 (unsigned long)ts->tv_sec * 1000000ULL;
 317         return(xtime);
 318 }
 319
 320
 321 /*
 322  * Convert a HAMMER filesystem object type to a vnode type
 323  */
 324 enum vtype
 325 hammer_get_vnode_type(u_int8_t obj_type)
 326 {
 327         switch(obj_type) {
 328         case HAMMER_OBJTYPE_DIRECTORY:
 329                 return(VDIR);
 330         case HAMMER_OBJTYPE_REGFILE:
 331                 return(VREG);
 332         case HAMMER_OBJTYPE_DBFILE:
 333                 return(VDATABASE);
 334         case HAMMER_OBJTYPE_FIFO:
 335                 return(VFIFO);
 336         case HAMMER_OBJTYPE_SOCKET:
 337                 return(VSOCK);
 338         case HAMMER_OBJTYPE_CDEV:
 339                 return(VCHR);
 340         case HAMMER_OBJTYPE_BDEV:
 341                 return(VBLK);
 342         case HAMMER_OBJTYPE_SOFTLINK:
 343                 return(VLNK);
 344         default:
 345                 return(VBAD);
 346         }
 347         /* not reached */
 348 }
 349
 350 int
 351 hammer_get_dtype(u_int8_t obj_type)
 352 {
 353         switch(obj_type) {
 354         case HAMMER_OBJTYPE_DIRECTORY:
 355                 return(DT_DIR);
 356         case HAMMER_OBJTYPE_REGFILE:
 357                 return(DT_REG);
 358         case HAMMER_OBJTYPE_DBFILE:
 359                 return(DT_DBF);
 360         case HAMMER_OBJTYPE_FIFO:
 361                 return(DT_FIFO);
 362         case HAMMER_OBJTYPE_SOCKET:
 363                 return(DT_SOCK);
 364         case HAMMER_OBJTYPE_CDEV:
 365                 return(DT_CHR);
 366         case HAMMER_OBJTYPE_BDEV:
 367                 return(DT_BLK);
 368         case HAMMER_OBJTYPE_SOFTLINK:
 369                 return(DT_LNK);
 370         default:
 371                 return(DT_UNKNOWN);
 372         }
 373         /* not reached */
 374 }
 375
 376 u_int8_t
 377 hammer_get_obj_type(enum vtype vtype)
 378 {
 379         switch(vtype) {
 380         case VDIR:
 381                 return(HAMMER_OBJTYPE_DIRECTORY);
 382         case VREG:
 383                 return(HAMMER_OBJTYPE_REGFILE);
 384         case VDATABASE:
 385                 return(HAMMER_OBJTYPE_DBFILE);
 386         case VFIFO:
 387                 return(HAMMER_OBJTYPE_FIFO);
 388         case VSOCK:
 389                 return(HAMMER_OBJTYPE_SOCKET);
 390         case VCHR:
 391                 return(HAMMER_OBJTYPE_CDEV);
 392         case VBLK:
 393                 return(HAMMER_OBJTYPE_BDEV);
 394         case VLNK:
 395                 return(HAMMER_OBJTYPE_SOFTLINK);
 396         default:
 397                 return(HAMMER_OBJTYPE_UNKNOWN);
 398         }
 399         /* not reached */
 400 }
 401
 402 /*
 403  * Return flags for hammer_delete_at_cursor()
 404  */
 405 int
 406 hammer_nohistory(hammer_inode_t ip)
 407 {
 408         if (ip->hmp->hflags & HMNT_NOHISTORY)
 409                 return(HAMMER_DELETE_DESTROY);
 410         if (ip->ino_data.uflags & (SF_NOHISTORY|UF_NOHISTORY))
 411                 return(HAMMER_DELETE_DESTROY);
 412         return(0);
 413 }
 414
 415 /*
 416  * ALGORITHM VERSION 1:
 417  *      Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 418  *      crc in the MSB and 0 in the LSB.  The caller will use the low 32 bits
 419  *      to generate a unique key and will scan all entries with the same upper
 420  *      32 bits when issuing a lookup.
 421  *
 422  *      0hhhhhhhhhhhhhhh hhhhhhhhhhhhhhhh 0000000000000000 0000000000000000
 423  *
 424  * ALGORITHM VERSION 2:
 425  *
 426  *      The 64 bit hash key is generated from the following components.  The
 427  *      first three characters are encoded as 5-bit quantities, the middle
 428  *      N characters are hashed into a 6 bit quantity, and the last two
 429  *      characters are encoded as 5-bit quantities.  A 32 bit hash of the
 430  *      entire filename is encoded in the low 32 bits.  Bit 0 is set to
 431  *      0 to guarantee us a 2^24 bit iteration space.
 432  *
 433  *      0aaaaabbbbbccccc mmmmmmyyyyyzzzzz hhhhhhhhhhhhhhhh hhhhhhhhhhhhhhh0
 434  *
 435  *      This gives us a domain sort for the first three characters, the last
 436  *      two characters, and breaks the middle space into 64 random domains.
 437  *      The domain sort folds upper case, lower case, digits, and punctuation
 438  *      spaces together, the idea being the filenames tend to not be a mix
 439  *      of those domains.
 440  *
 441  *      The 64 random domains act as a sub-sort for the middle characters
 442  *      but may cause a random seek.  If the filesystem is being accessed
 443  *      in sorted order we should tend to get very good linearity for most
 444  *      filenames and devolve into more random seeks otherwise.
 445  *
 446  * We strip bit 63 in order to provide a positive key, this way a seek
 447  * offset of 0 will represent the base of the directory.
 448  *
 449  * This function can never return 0.  We use the MSB-0 space to synthesize
 450  * artificial directory entries such as "." and "..".
 451  */
 452 int64_t
 453 hammer_directory_namekey(hammer_inode_t dip, const void *name, int len,
 454                          u_int32_t *max_iterationsp)
 455 {
 456         int64_t key;
 457         int32_t crcx;
 458         const char *aname = name;
 459
 460         switch (dip->ino_data.cap_flags & HAMMER_INODE_CAP_DIRHASH_MASK) {
 461         case HAMMER_INODE_CAP_DIRHASH_ALG0:
 462                 key = (int64_t)(crc32(aname, len) & 0x7FFFFFFF) << 32;
 463                 if (key == 0)
 464                         key |= 0x100000000LL;
 465                 *max_iterationsp = 0xFFFFFFFFU;
 466                 break;
 467         case HAMMER_INODE_CAP_DIRHASH_ALG1:
 468                 key = (u_int32_t)crc32(aname, len) & 0xFFFFFFFEU;
 469
 470                 switch(len) {
 471                 default:
 472                         crcx = crc32(aname + 3, len - 5);
 473                         crcx = crcx ^ (crcx >> 6) ^ (crcx >> 12);
 474                         key |=  (int64_t)(crcx & 0x3F) << 42;
 475                         /* fall through */
 476                 case 5:
 477                 case 4:
 478                         /* fall through */
 479                 case 3:
 480                         key |= ((int64_t)(aname[2] & 0x1F) << 48);
 481                         /* fall through */
 482                 case 2:
 483                         key |= ((int64_t)(aname[1] & 0x1F) << 53) |
 484                                ((int64_t)(aname[len-2] & 0x1F) << 37);
 485                         /* fall through */
 486                 case 1:
 487                         key |= ((int64_t)(aname[0] & 0x1F) << 58) |
 488                                ((int64_t)(aname[len-1] & 0x1F) << 32);
 489                         /* fall through */
 490                 case 0:
 491                         break;
 492                 }
 493                 if ((key & 0xFFFFFFFF00000000LL) == 0)
 494                         key |= 0x100000000LL;
 495                 if (hammer_debug_general & 0x0400) {
 496                         kprintf("namekey2: 0x%016llx %*.*s\n",
 497                                 key, len, len, aname);
 498                 }
 499                 *max_iterationsp = 0x00FFFFFF;
 500                 break;
 501         case HAMMER_INODE_CAP_DIRHASH_ALG2:
 502         case HAMMER_INODE_CAP_DIRHASH_ALG3:
 503         default:
 504                 key = 0;                        /* compiler warning */
 505                 *max_iterationsp = 1;           /* sanity */
 506                 panic("hammer_directory_namekey: bad algorithm %p\n", dip);
 507                 break;
 508         }
 509         return(key);
 510 }
 511
 512 /*
 513  * Convert string after @@ (@@ not included) to TID.  Returns 0 on success,
 514  * EINVAL on failure.
 515  *
 516  * If this function fails *ispfs, *tidp, and *localizationp will not
 517  * be modified.
 518  */
 519 int
 520 hammer_str_to_tid(const char *str, int *ispfsp,
 521                   hammer_tid_t *tidp, u_int32_t *localizationp)
 522 {
 523         hammer_tid_t tid;
 524         u_int32_t localization;
 525         char *ptr;
 526         int ispfs;
 527         int n;
 528
 529         /*
 530          * Forms allowed for TID:  "0x%016llx"
 531          *                         "-1"
 532          */
 533         tid = strtouq(str, &ptr, 0);
 534         n = ptr - str;
 535         if (n == 2 && str[0] == '-' && str[1] == '1') {
 536                 /* ok */
 537         } else if (n == 18 && str[0] == '0' && (str[1] | 0x20) == 'x') {
 538                 /* ok */
 539         } else {
 540                 return(EINVAL);
 541         }
 542
 543         /*
 544          * Forms allowed for PFS:  ":%05d"  (i.e. "...:0" would be illegal).
 545          */
 546         str = ptr;
 547         if (*str == ':') {
 548                 localization = strtoul(str + 1, &ptr, 10) << 16;
 549                 if (ptr - str != 6)
 550                         return(EINVAL);
 551                 str = ptr;
 552                 ispfs = 1;
 553         } else {
 554                 localization = *localizationp;
 555                 ispfs = 0;
 556         }
 557
 558         /*
 559          * Any trailing junk invalidates special extension handling.
 560          */
 561         if (*str)
 562                 return(EINVAL);
 563         *tidp = tid;
 564         *localizationp = localization;
 565         *ispfsp = ispfs;
 566         return(0);
 567 }
 568
 569 void
 570 hammer_crc_set_blockmap(hammer_blockmap_t blockmap)
 571 {
 572         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 573 }
 574
 575 void
 576 hammer_crc_set_volume(hammer_volume_ondisk_t ondisk)
 577 {
 578         ondisk->vol_crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 579                           crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 580 }
 581
 582 int
 583 hammer_crc_test_blockmap(hammer_blockmap_t blockmap)
 584 {
 585         hammer_crc_t crc;
 586
 587         crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 588         return (blockmap->entry_crc == crc);
 589 }
 590
 591 int
 592 hammer_crc_test_volume(hammer_volume_ondisk_t ondisk)
 593 {
 594         hammer_crc_t crc;
 595
 596         crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 597               crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 598         return (ondisk->vol_crc == crc);
 599 }
 600
 601 int
 602 hammer_crc_test_btree(hammer_node_ondisk_t ondisk)
 603 {
 604         hammer_crc_t crc;
 605
 606         crc = crc32(&ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
 607         return (ondisk->crc == crc);
 608 }
 609
 610 /*
 611  * Test or set the leaf->data_crc field.  Deal with any special cases given
 612  * a generic B-Tree leaf element and its data.
 613  *
 614  * NOTE: Inode-data: the atime and mtime fields are not CRCd, allowing them
 615  *       to be updated in-place.
 616  */
 617 int
 618 hammer_crc_test_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 619 {
 620         hammer_crc_t crc;
 621
 622         if (leaf->data_len == 0) {
 623                 crc = 0;
 624         } else {
 625                 switch(leaf->base.rec_type) {
 626                 case HAMMER_RECTYPE_INODE:
 627                         if (leaf->data_len != sizeof(struct hammer_inode_data))
 628                                 return(0);
 629                         crc = crc32(data, HAMMER_INODE_CRCSIZE);
 630                         break;
 631                 default:
 632                         crc = crc32(data, leaf->data_len);
 633                         break;
 634                 }
 635         }
 636         return (leaf->data_crc == crc);
 637 }
 638
 639 void
 640 hammer_crc_set_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 641 {
 642         if (leaf->data_len == 0) {
 643                 leaf->data_crc = 0;
 644         } else {
 645                 switch(leaf->base.rec_type) {
 646                 case HAMMER_RECTYPE_INODE:
 647                         KKASSERT(leaf->data_len ==
 648                                   sizeof(struct hammer_inode_data));
 649                         leaf->data_crc = crc32(data, HAMMER_INODE_CRCSIZE);
 650                         break;
 651                 default:
 652                         leaf->data_crc = crc32(data, leaf->data_len);
 653                         break;
 654                 }
 655         }
 656 }
 657
 658 void
 659 hkprintf(const char *ctl, ...)
 660 {
 661         __va_list va;
 662
 663         if (hammer_debug_debug) {
 664                 __va_start(va, ctl);
 665                 kvprintf(ctl, va);
 666                 __va_end(va);
 667         }
 668 }
 669
 670 /*
 671  * Return the block size at the specified file offset.
 672  */
 673 int
 674 hammer_blocksize(int64_t file_offset)
 675 {
 676         if (file_offset < HAMMER_XDEMARC)
 677                 return(HAMMER_BUFSIZE);
 678         else
 679                 return(HAMMER_XBUFSIZE);
 680 }
 681
 682 /*
 683  * Return the demarkation point between the two offsets where
 684  * the block size changes.
 685  */
 686 int64_t
 687 hammer_blockdemarc(int64_t file_offset1, int64_t file_offset2)
 688 {
 689         if (file_offset1 < HAMMER_XDEMARC) {
 690                 if (file_offset2 <= HAMMER_XDEMARC)
 691                         return(file_offset2);
 692                 return(HAMMER_XDEMARC);
 693         }
 694         panic("hammer_blockdemarc: illegal range %lld %lld\n",
 695               file_offset1, file_offset2);
 696 }
 697
 698 udev_t
 699 hammer_fsid_to_udev(uuid_t *uuid)
 700 {
 701         u_int32_t crc;
 702
 703         crc = crc32(uuid, sizeof(*uuid));
 704         return((udev_t)crc);
 705 }
 706