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 1.34 2008/07/11 01:22:29 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  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 417  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
 418  * generate a unique key and will scan all entries with the same upper
 419  * 32 bits when issuing a lookup.
 420  *
 421  * We strip bit 63 in order to provide a positive key, this way a seek
 422  * offset of 0 will represent the base of the directory.
 423  *
 424  * This function can never return 0.  We use the MSB-0 space to synthesize
 425  * artificial directory entries such as "." and "..".
 426  */
 427 int64_t
 428 hammer_directory_namekey(const void *name, int len)
 429 {
 430         int64_t key;
 431
 432         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
 433         if (key == 0)
 434                 key |= 0x100000000LL;
 435         return(key);
 436 }
 437
 438 hammer_tid_t
 439 hammer_str_to_tid(const char *str, int *ispfs, u_int32_t *localizationp)
 440
 441 {
 442         hammer_tid_t tid;
 443         char *ptr;
 444
 445         tid = strtouq(str, &ptr, 0);
 446         if (*ptr == ':') {
 447                 *ispfs = 1;
 448                 *localizationp = strtoul(ptr + 1, NULL, 10) << 16;
 449         } else {
 450                 *ispfs = 0;
 451         }
 452         return(tid);
 453 }
 454
 455 void
 456 hammer_crc_set_blockmap(hammer_blockmap_t blockmap)
 457 {
 458         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 459 }
 460
 461 void
 462 hammer_crc_set_volume(hammer_volume_ondisk_t ondisk)
 463 {
 464         ondisk->vol_crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 465                           crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 466 }
 467
 468 int
 469 hammer_crc_test_blockmap(hammer_blockmap_t blockmap)
 470 {
 471         hammer_crc_t crc;
 472
 473         crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 474         return (blockmap->entry_crc == crc);
 475 }
 476
 477 int
 478 hammer_crc_test_volume(hammer_volume_ondisk_t ondisk)
 479 {
 480         hammer_crc_t crc;
 481
 482         crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 483               crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 484         return (ondisk->vol_crc == crc);
 485 }
 486
 487 int
 488 hammer_crc_test_btree(hammer_node_ondisk_t ondisk)
 489 {
 490         hammer_crc_t crc;
 491
 492         crc = crc32(&ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
 493         return (ondisk->crc == crc);
 494 }
 495
 496 /*
 497  * Test or set the leaf->data_crc field.  Deal with any special cases given
 498  * a generic B-Tree leaf element and its data.
 499  *
 500  * NOTE: Inode-data: the atime and mtime fields are not CRCd, allowing them
 501  *       to be updated in-place.
 502  */
 503 int
 504 hammer_crc_test_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 505 {
 506         hammer_crc_t crc;
 507
 508         if (leaf->data_len == 0) {
 509                 crc = 0;
 510         } else {
 511                 switch(leaf->base.rec_type) {
 512                 case HAMMER_RECTYPE_INODE:
 513                         if (leaf->data_len != sizeof(struct hammer_inode_data))
 514                                 return(0);
 515                         crc = crc32(data, HAMMER_INODE_CRCSIZE);
 516                         break;
 517                 default:
 518                         crc = crc32(data, leaf->data_len);
 519                         break;
 520                 }
 521         }
 522         return (leaf->data_crc == crc);
 523 }
 524
 525 void
 526 hammer_crc_set_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 527 {
 528         if (leaf->data_len == 0) {
 529                 leaf->data_crc = 0;
 530         } else {
 531                 switch(leaf->base.rec_type) {
 532                 case HAMMER_RECTYPE_INODE:
 533                         KKASSERT(leaf->data_len ==
 534                                   sizeof(struct hammer_inode_data));
 535                         leaf->data_crc = crc32(data, HAMMER_INODE_CRCSIZE);
 536                         break;
 537                 default:
 538                         leaf->data_crc = crc32(data, leaf->data_len);
 539                         break;
 540                 }
 541         }
 542 }
 543
 544 void
 545 hkprintf(const char *ctl, ...)
 546 {
 547         __va_list va;
 548
 549         if (hammer_debug_debug) {
 550                 __va_start(va, ctl);
 551                 kvprintf(ctl, va);
 552                 __va_end(va);
 553         }
 554 }
 555
 556 /*
 557  * Return the block size at the specified file offset.
 558  */
 559 int
 560 hammer_blocksize(int64_t file_offset)
 561 {
 562         if (file_offset < HAMMER_XDEMARC)
 563                 return(HAMMER_BUFSIZE);
 564         else
 565                 return(HAMMER_XBUFSIZE);
 566 }
 567
 568 /*
 569  * Return the demarkation point between the two offsets where
 570  * the block size changes.
 571  */
 572 int64_t
 573 hammer_blockdemarc(int64_t file_offset1, int64_t file_offset2)
 574 {
 575         if (file_offset1 < HAMMER_XDEMARC) {
 576                 if (file_offset2 <= HAMMER_XDEMARC)
 577                         return(file_offset2);
 578                 return(HAMMER_XDEMARC);
 579         }
 580         panic("hammer_blockdemarc: illegal range %lld %lld\n",
 581               file_offset1, file_offset2);
 582 }
 583
 584 udev_t
 585 hammer_fsid_to_udev(uuid_t *uuid)
 586 {
 587         u_int32_t crc;
 588
 589         crc = crc32(uuid, sizeof(*uuid));
 590         return((udev_t)crc);
 591 }
 592