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 1.28 2008/06/23 21:42:48 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 void
  98 hammer_lock_sh(struct hammer_lock *lock)
  99 {
 100         KKASSERT(lock->refs > 0);
 101         crit_enter();
 102         while (lock->locktd != NULL) {
 103                 if (lock->locktd == curthread) {
 104                         Debugger("hammer_lock_sh: lock_sh on exclusive");
 105                         ++lock->lockcount;
 106                         crit_exit();
 107                         return;
 108                 }
 109                 lock->wanted = 1;
 110                 tsleep(lock, 0, "hmrlck", 0);
 111         }
 112         KKASSERT(lock->lockcount <= 0);
 113         --lock->lockcount;
 114         crit_exit();
 115 }
 116
 117 /*
 118  * Obtain a shared lock at a lower priority then thread waiting for an
 119  * exclusive lock.  To avoid a deadlock this may only be done if no other
 120  * shared locks are being held by the caller.
 121  */
 122 void
 123 hammer_lock_sh_lowpri(struct hammer_lock *lock)
 124 {
 125         KKASSERT(lock->refs > 0);
 126         crit_enter();
 127         while (lock->locktd != NULL || lock->exwanted) {
 128                 if (lock->locktd == curthread) {
 129                         Debugger("hammer_lock_sh: lock_sh on exclusive");
 130                         ++lock->lockcount;
 131                         crit_exit();
 132                         return;
 133                 }
 134                 lock->wanted = 1;
 135                 tsleep(lock, 0, "hmrlck", 0);
 136         }
 137         KKASSERT(lock->lockcount <= 0);
 138         --lock->lockcount;
 139         crit_exit();
 140 }
 141
 142 int
 143 hammer_lock_sh_try(struct hammer_lock *lock)
 144 {
 145         KKASSERT(lock->refs > 0);
 146         crit_enter();
 147         if (lock->locktd) {
 148                 crit_exit();
 149                 return(EAGAIN);
 150         }
 151         KKASSERT(lock->lockcount <= 0);
 152         --lock->lockcount;
 153         crit_exit();
 154         return(0);
 155 }
 156
 157 /*
 158  * Upgrade a shared lock to an exclusively held lock.  This function will
 159  * return EDEADLK If there is more then one shared holder.
 160  *
 161  * No error occurs and no action is taken if the lock is already exclusively
 162  * held by the caller.  If the lock is not held at all or held exclusively
 163  * by someone else, this function will panic.
 164  */
 165 int
 166 hammer_lock_upgrade(struct hammer_lock *lock)
 167 {
 168         int error;
 169
 170         crit_enter();
 171         if (lock->lockcount > 0) {
 172                 if (lock->locktd != curthread)
 173                         panic("hammer_lock_upgrade: illegal lock state");
 174                 error = 0;
 175         } else if (lock->lockcount == -1) {
 176                 lock->lockcount = 1;
 177                 lock->locktd = curthread;
 178                 error = 0;
 179         } else if (lock->lockcount != 0) {
 180                 error = EDEADLK;
 181         } else {
 182                 panic("hammer_lock_upgrade: lock is not held");
 183                 /* NOT REACHED */
 184                 error = 0;
 185         }
 186         crit_exit();
 187         return(error);
 188 }
 189
 190 /*
 191  * Downgrade an exclusively held lock to a shared lock.
 192  */
 193 void
 194 hammer_lock_downgrade(struct hammer_lock *lock)
 195 {
 196         KKASSERT(lock->lockcount == 1 && lock->locktd == curthread);
 197         crit_enter();
 198         lock->lockcount = -1;
 199         lock->locktd = NULL;
 200         if (lock->wanted) {
 201                 lock->wanted = 0;
 202                 wakeup(lock);
 203         }
 204         crit_exit();
 205         /* XXX memory barrier */
 206 }
 207
 208 void
 209 hammer_unlock(struct hammer_lock *lock)
 210 {
 211         crit_enter();
 212         KKASSERT(lock->lockcount != 0);
 213         if (lock->lockcount < 0) {
 214                 if (++lock->lockcount == 0 && lock->wanted) {
 215                         lock->wanted = 0;
 216                         wakeup(lock);
 217                 }
 218         } else {
 219                 KKASSERT(lock->locktd == curthread);
 220                 if (--lock->lockcount == 0) {
 221                         lock->locktd = NULL;
 222                         if (lock->wanted) {
 223                                 lock->wanted = 0;
 224                                 wakeup(lock);
 225                         }
 226                 }
 227
 228         }
 229         crit_exit();
 230 }
 231
 232 void
 233 hammer_ref(struct hammer_lock *lock)
 234 {
 235         KKASSERT(lock->refs >= 0);
 236         crit_enter();
 237         ++lock->refs;
 238         crit_exit();
 239 }
 240
 241 void
 242 hammer_unref(struct hammer_lock *lock)
 243 {
 244         KKASSERT(lock->refs > 0);
 245         crit_enter();
 246         --lock->refs;
 247         crit_exit();
 248 }
 249
 250 /*
 251  * The sync_lock must be held when doing any modifying operations on
 252  * meta-data.  The flusher holds the lock exclusively while the reblocker
 253  * and pruner use a shared lock.
 254  *
 255  * Modifying operations can run in parallel until the flusher needs to
 256  * sync the disk media.
 257  */
 258 void
 259 hammer_sync_lock_ex(hammer_transaction_t trans)
 260 {
 261         ++trans->sync_lock_refs;
 262         hammer_lock_ex(&trans->hmp->sync_lock);
 263 }
 264
 265 void
 266 hammer_sync_lock_sh(hammer_transaction_t trans)
 267 {
 268         ++trans->sync_lock_refs;
 269         hammer_lock_sh(&trans->hmp->sync_lock);
 270 }
 271
 272 int
 273 hammer_sync_lock_sh_try(hammer_transaction_t trans)
 274 {
 275         int error;
 276
 277         ++trans->sync_lock_refs;
 278         if ((error = hammer_lock_sh_try(&trans->hmp->sync_lock)) != 0)
 279                 --trans->sync_lock_refs;
 280         return (error);
 281 }
 282
 283 void
 284 hammer_sync_unlock(hammer_transaction_t trans)
 285 {
 286         --trans->sync_lock_refs;
 287         hammer_unlock(&trans->hmp->sync_lock);
 288 }
 289
 290 /*
 291  * Misc
 292  */
 293 u_int32_t
 294 hammer_to_unix_xid(uuid_t *uuid)
 295 {
 296         return(*(u_int32_t *)&uuid->node[2]);
 297 }
 298
 299 void
 300 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 301 {
 302         bzero(uuid, sizeof(*uuid));
 303         *(u_int32_t *)&uuid->node[2] = guid;
 304 }
 305
 306 void
 307 hammer_time_to_timespec(u_int64_t xtime, struct timespec *ts)
 308 {
 309         ts->tv_sec = (unsigned long)(xtime / 1000000);
 310         ts->tv_nsec = (unsigned int)(xtime % 1000000) * 1000L;
 311 }
 312
 313 u_int64_t
 314 hammer_timespec_to_time(struct timespec *ts)
 315 {
 316         u_int64_t xtime;
 317
 318         xtime = (unsigned)(ts->tv_nsec / 1000) +
 319                 (unsigned long)ts->tv_sec * 1000000ULL;
 320         return(xtime);
 321 }
 322
 323
 324 /*
 325  * Convert a HAMMER filesystem object type to a vnode type
 326  */
 327 enum vtype
 328 hammer_get_vnode_type(u_int8_t obj_type)
 329 {
 330         switch(obj_type) {
 331         case HAMMER_OBJTYPE_DIRECTORY:
 332                 return(VDIR);
 333         case HAMMER_OBJTYPE_REGFILE:
 334                 return(VREG);
 335         case HAMMER_OBJTYPE_DBFILE:
 336                 return(VDATABASE);
 337         case HAMMER_OBJTYPE_FIFO:
 338                 return(VFIFO);
 339         case HAMMER_OBJTYPE_CDEV:
 340                 return(VCHR);
 341         case HAMMER_OBJTYPE_BDEV:
 342                 return(VBLK);
 343         case HAMMER_OBJTYPE_SOFTLINK:
 344                 return(VLNK);
 345         default:
 346                 return(VBAD);
 347         }
 348         /* not reached */
 349 }
 350
 351 int
 352 hammer_get_dtype(u_int8_t obj_type)
 353 {
 354         switch(obj_type) {
 355         case HAMMER_OBJTYPE_DIRECTORY:
 356                 return(DT_DIR);
 357         case HAMMER_OBJTYPE_REGFILE:
 358                 return(DT_REG);
 359         case HAMMER_OBJTYPE_DBFILE:
 360                 return(DT_DBF);
 361         case HAMMER_OBJTYPE_FIFO:
 362                 return(DT_FIFO);
 363         case HAMMER_OBJTYPE_CDEV:
 364                 return(DT_CHR);
 365         case HAMMER_OBJTYPE_BDEV:
 366                 return(DT_BLK);
 367         case HAMMER_OBJTYPE_SOFTLINK:
 368                 return(DT_LNK);
 369         default:
 370                 return(DT_UNKNOWN);
 371         }
 372         /* not reached */
 373 }
 374
 375 u_int8_t
 376 hammer_get_obj_type(enum vtype vtype)
 377 {
 378         switch(vtype) {
 379         case VDIR:
 380                 return(HAMMER_OBJTYPE_DIRECTORY);
 381         case VREG:
 382                 return(HAMMER_OBJTYPE_REGFILE);
 383         case VDATABASE:
 384                 return(HAMMER_OBJTYPE_DBFILE);
 385         case VFIFO:
 386                 return(HAMMER_OBJTYPE_FIFO);
 387         case VCHR:
 388                 return(HAMMER_OBJTYPE_CDEV);
 389         case VBLK:
 390                 return(HAMMER_OBJTYPE_BDEV);
 391         case VLNK:
 392                 return(HAMMER_OBJTYPE_SOFTLINK);
 393         default:
 394                 return(HAMMER_OBJTYPE_UNKNOWN);
 395         }
 396         /* not reached */
 397 }
 398
 399 int
 400 hammer_nohistory(hammer_inode_t ip)
 401 {
 402         if (ip->hmp->hflags & HMNT_NOHISTORY)
 403                 return(1);
 404         if (ip->ino_data.uflags & (SF_NOHISTORY|UF_NOHISTORY))
 405                 return(1);
 406         return(0);
 407 }
 408
 409 /*
 410  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 411  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
 412  * generate a unique key and will scan all entries with the same upper
 413  * 32 bits when issuing a lookup.
 414  *
 415  * We strip bit 63 in order to provide a positive key, this way a seek
 416  * offset of 0 will represent the base of the directory.
 417  *
 418  * This function can never return 0.  We use the MSB-0 space to synthesize
 419  * artificial directory entries such as "." and "..".
 420  */
 421 int64_t
 422 hammer_directory_namekey(const void *name, int len)
 423 {
 424         int64_t key;
 425
 426         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
 427         if (key == 0)
 428                 key |= 0x100000000LL;
 429         return(key);
 430 }
 431
 432 hammer_tid_t
 433 hammer_str_to_tid(const char *str)
 434 {
 435         hammer_tid_t tid;
 436
 437         tid = strtouq(str, NULL, 0);                    /* full TID */
 438         return(tid);
 439 }
 440
 441 void
 442 hammer_crc_set_blockmap(hammer_blockmap_t blockmap)
 443 {
 444         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 445 }
 446
 447 void
 448 hammer_crc_set_volume(hammer_volume_ondisk_t ondisk)
 449 {
 450         ondisk->vol_crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 451                           crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 452 }
 453
 454 int
 455 hammer_crc_test_blockmap(hammer_blockmap_t blockmap)
 456 {
 457         hammer_crc_t crc;
 458
 459         crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 460         return (blockmap->entry_crc == crc);
 461 }
 462
 463 int
 464 hammer_crc_test_volume(hammer_volume_ondisk_t ondisk)
 465 {
 466         hammer_crc_t crc;
 467
 468         crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
 469               crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
 470         return (ondisk->vol_crc == crc);
 471 }
 472
 473 int
 474 hammer_crc_test_btree(hammer_node_ondisk_t ondisk)
 475 {
 476         hammer_crc_t crc;
 477
 478         crc = crc32(&ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
 479         return (ondisk->crc == crc);
 480 }
 481
 482 /*
 483  * Test or set the leaf->data_crc field.  Deal with any special cases given
 484  * a generic B-Tree leaf element and its data.
 485  *
 486  * NOTE: Inode-data: the atime and mtime fields are not CRCd, allowing them
 487  *       to be updated in-place.
 488  */
 489 int
 490 hammer_crc_test_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 491 {
 492         hammer_crc_t crc;
 493
 494         if (leaf->data_len == 0) {
 495                 crc = 0;
 496         } else {
 497                 switch(leaf->base.rec_type) {
 498                 case HAMMER_RECTYPE_INODE:
 499                         if (leaf->data_len != sizeof(struct hammer_inode_data))
 500                                 return(0);
 501                         crc = crc32(data, HAMMER_INODE_CRCSIZE);
 502                         break;
 503                 default:
 504                         crc = crc32(data, leaf->data_len);
 505                         break;
 506                 }
 507         }
 508         return (leaf->data_crc == crc);
 509 }
 510
 511 void
 512 hammer_crc_set_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 513 {
 514         if (leaf->data_len == 0) {
 515                 leaf->data_crc = 0;
 516         } else {
 517                 switch(leaf->base.rec_type) {
 518                 case HAMMER_RECTYPE_INODE:
 519                         KKASSERT(leaf->data_len ==
 520                                   sizeof(struct hammer_inode_data));
 521                         leaf->data_crc = crc32(data, HAMMER_INODE_CRCSIZE);
 522                         break;
 523                 default:
 524                         leaf->data_crc = crc32(data, leaf->data_len);
 525                         break;
 526                 }
 527         }
 528 }
 529
 530 void
 531 hkprintf(const char *ctl, ...)
 532 {
 533         __va_list va;
 534
 535         if (hammer_debug_debug) {
 536                 __va_start(va, ctl);
 537                 kvprintf(ctl, va);
 538                 __va_end(va);
 539         }
 540 }
 541
 542 /*
 543  * Return the block size at the specified file offset.
 544  */
 545 int
 546 hammer_blocksize(int64_t file_offset)
 547 {
 548         if (file_offset < HAMMER_XDEMARC)
 549                 return(HAMMER_BUFSIZE);
 550         else
 551                 return(HAMMER_XBUFSIZE);
 552 }
 553
 554 /*
 555  * Return the demarkation point between the two offsets where
 556  * the block size changes.
 557  */
 558 int64_t
 559 hammer_blockdemarc(int64_t file_offset1, int64_t file_offset2)
 560 {
 561         if (file_offset1 < HAMMER_XDEMARC) {
 562                 if (file_offset2 <= HAMMER_XDEMARC)
 563                         return(file_offset2);
 564                 return(HAMMER_XDEMARC);
 565         }
 566         panic("hammer_blockdemarc: illegal range %lld %lld\n",
 567               file_offset1, file_offset2);
 568 }
 569