sys/vfs/hammer2/hammer2_subr.c

   1 /*
   2  * Copyright (c) 2011-2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35 #include <sys/cdefs.h>
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/types.h>
  39 #include <sys/lock.h>
  40 #include <sys/uuid.h>
  41 #include <sys/dirent.h>
  42
  43 #include "hammer2.h"
  44
  45 /*
  46  * HAMMER2 inode locks
  47  *
  48  * HAMMER2 offers shared locks and exclusive locks on inodes.
  49  *
  50  * An inode's ip->chain pointer is resolved and stable while an inode is
  51  * locked, and can be cleaned out at any time (become NULL) when an inode
  52  * is not locked.
  53  *
  54  * The underlying chain is also locked and returned.
  55  *
  56  * NOTE: We don't combine the inode/chain lock because putting away an
  57  *       inode would otherwise confuse multiple lock holders of the inode.
  58  */
  59 hammer2_chain_t *
  60 hammer2_inode_lock_ex(hammer2_inode_t *ip)
  61 {
  62         hammer2_chain_t *chain;
  63
  64         hammer2_inode_ref(ip);
  65         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_EXCLUSIVE);
  66
  67         /*
  68          * ip->chain fixup.  Certain duplications used to move inodes
  69          * into indirect blocks (for example) can cause ip->chain to
  70          * become stale.
  71          */
  72 again:
  73         chain = ip->chain;
  74         while (chain->duplink && (chain->flags & HAMMER2_CHAIN_DELETED))
  75                 chain = chain->duplink;
  76         if (ip->chain != chain) {
  77                 hammer2_chain_ref(chain);
  78                 hammer2_chain_drop(ip->chain);
  79                 ip->chain = chain;
  80         }
  81
  82         KKASSERT(chain != NULL);        /* for now */
  83         hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS);
  84
  85         /*
  86          * Resolve duplication races
  87          */
  88         if (chain->duplink && (chain->flags & HAMMER2_CHAIN_DELETED)) {
  89                 hammer2_chain_unlock(chain);
  90                 goto again;
  91         }
  92         return (chain);
  93 }
  94
  95 void
  96 hammer2_inode_unlock_ex(hammer2_inode_t *ip, hammer2_chain_t *chain)
  97 {
  98         /*
  99          * XXX this will catch parent directories too which we don't
 100          *     really want.
 101          */
 102         if (chain)
 103                 hammer2_chain_unlock(chain);
 104
 105         /*
 106          * Recalculate ip->chain on exclusive unlock too, it may
 107          * allow us to free stale chains more quickly.
 108          */
 109         if ((chain = ip->chain) != NULL) {
 110                 while (chain->duplink && (chain->flags & HAMMER2_CHAIN_DELETED))
 111                         chain = chain->duplink;
 112                 if (ip->chain != chain) {
 113                         hammer2_chain_ref(chain);
 114                         hammer2_chain_drop(ip->chain);
 115                         ip->chain = chain;
 116                 }
 117         }
 118
 119         ccms_thread_unlock(&ip->topo_cst);
 120         hammer2_inode_drop(ip);
 121 }
 122
 123 /*
 124  * NOTE: We don't combine the inode/chain lock because putting away an
 125  *       inode would otherwise confuse multiple lock holders of the inode.
 126  *
 127  *       Shared locks are especially sensitive to having too many shared
 128  *       lock counts (from the same thread) on certain paths which might
 129  *       need to upgrade them.  Only one count of a shared lock can be
 130  *       upgraded.
 131  */
 132 hammer2_chain_t *
 133 hammer2_inode_lock_sh(hammer2_inode_t *ip)
 134 {
 135         hammer2_chain_t *chain;
 136
 137         hammer2_inode_ref(ip);
 138 again:
 139         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_SHARED);
 140
 141         chain = ip->chain;
 142         KKASSERT(chain != NULL);        /* for now */
 143         hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 144                                   HAMMER2_RESOLVE_SHARED);
 145
 146         /*
 147          * Resolve duplication races
 148          */
 149         if (chain->duplink && (chain->flags & HAMMER2_CHAIN_DELETED)) {
 150                 hammer2_chain_unlock(chain);
 151                 ccms_thread_unlock(&ip->topo_cst);
 152                 chain = hammer2_inode_lock_ex(ip);
 153                 hammer2_inode_unlock_ex(ip, chain);
 154                 goto again;
 155         }
 156         return (chain);
 157 }
 158
 159 void
 160 hammer2_inode_unlock_sh(hammer2_inode_t *ip, hammer2_chain_t *chain)
 161 {
 162         if (chain)
 163                 hammer2_chain_unlock(chain);
 164         ccms_thread_unlock(&ip->topo_cst);
 165         hammer2_inode_drop(ip);
 166 }
 167
 168 ccms_state_t
 169 hammer2_inode_lock_temp_release(hammer2_inode_t *ip)
 170 {
 171         return(ccms_thread_lock_temp_release(&ip->topo_cst));
 172 }
 173
 174 void
 175 hammer2_inode_lock_temp_restore(hammer2_inode_t *ip, ccms_state_t ostate)
 176 {
 177         ccms_thread_lock_temp_restore(&ip->topo_cst, ostate);
 178 }
 179
 180 ccms_state_t
 181 hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
 182 {
 183         return(ccms_thread_lock_upgrade(&ip->topo_cst));
 184 }
 185
 186 void
 187 hammer2_inode_lock_downgrade(hammer2_inode_t *ip, ccms_state_t ostate)
 188 {
 189         ccms_thread_lock_downgrade(&ip->topo_cst, ostate);
 190 }
 191
 192 /*
 193  * Mount-wide locks
 194  */
 195
 196 void
 197 hammer2_mount_exlock(hammer2_mount_t *hmp)
 198 {
 199         ccms_thread_lock(&hmp->vchain.core->cst, CCMS_STATE_EXCLUSIVE);
 200 }
 201
 202 void
 203 hammer2_mount_shlock(hammer2_mount_t *hmp)
 204 {
 205         ccms_thread_lock(&hmp->vchain.core->cst, CCMS_STATE_SHARED);
 206 }
 207
 208 void
 209 hammer2_mount_unlock(hammer2_mount_t *hmp)
 210 {
 211         ccms_thread_unlock(&hmp->vchain.core->cst);
 212 }
 213
 214 void
 215 hammer2_voldata_lock(hammer2_mount_t *hmp)
 216 {
 217         lockmgr(&hmp->voldatalk, LK_EXCLUSIVE);
 218 }
 219
 220 void
 221 hammer2_voldata_unlock(hammer2_mount_t *hmp, int modify)
 222 {
 223         if (modify &&
 224             (hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) {
 225                 atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
 226                 hammer2_chain_ref(&hmp->vchain);
 227         }
 228         lockmgr(&hmp->voldatalk, LK_RELEASE);
 229 }
 230
 231 /*
 232  * Return the directory entry type for an inode.
 233  *
 234  * ip must be locked sh/ex.
 235  */
 236 int
 237 hammer2_get_dtype(hammer2_chain_t *chain)
 238 {
 239         uint8_t type;
 240
 241         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 242
 243         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK)
 244                 type = chain->data->ipdata.target_type;
 245
 246         switch(type) {
 247         case HAMMER2_OBJTYPE_UNKNOWN:
 248                 return (DT_UNKNOWN);
 249         case HAMMER2_OBJTYPE_DIRECTORY:
 250                 return (DT_DIR);
 251         case HAMMER2_OBJTYPE_REGFILE:
 252                 return (DT_REG);
 253         case HAMMER2_OBJTYPE_FIFO:
 254                 return (DT_FIFO);
 255         case HAMMER2_OBJTYPE_CDEV:      /* not supported */
 256                 return (DT_CHR);
 257         case HAMMER2_OBJTYPE_BDEV:      /* not supported */
 258                 return (DT_BLK);
 259         case HAMMER2_OBJTYPE_SOFTLINK:
 260                 return (DT_LNK);
 261         case HAMMER2_OBJTYPE_HARDLINK:  /* (never directly associated w/vp) */
 262                 return (DT_UNKNOWN);
 263         case HAMMER2_OBJTYPE_SOCKET:
 264                 return (DT_SOCK);
 265         case HAMMER2_OBJTYPE_WHITEOUT:  /* not supported */
 266                 return (DT_UNKNOWN);
 267         default:
 268                 return (DT_UNKNOWN);
 269         }
 270         /* not reached */
 271 }
 272
 273 /*
 274  * Return the directory entry type for an inode
 275  */
 276 int
 277 hammer2_get_vtype(hammer2_chain_t *chain)
 278 {
 279         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 280
 281         switch(chain->data->ipdata.type) {
 282         case HAMMER2_OBJTYPE_UNKNOWN:
 283                 return (VBAD);
 284         case HAMMER2_OBJTYPE_DIRECTORY:
 285                 return (VDIR);
 286         case HAMMER2_OBJTYPE_REGFILE:
 287                 return (VREG);
 288         case HAMMER2_OBJTYPE_FIFO:
 289                 return (VFIFO);
 290         case HAMMER2_OBJTYPE_CDEV:      /* not supported */
 291                 return (VCHR);
 292         case HAMMER2_OBJTYPE_BDEV:      /* not supported */
 293                 return (VBLK);
 294         case HAMMER2_OBJTYPE_SOFTLINK:
 295                 return (VLNK);
 296         case HAMMER2_OBJTYPE_HARDLINK:  /* XXX */
 297                 return (VBAD);
 298         case HAMMER2_OBJTYPE_SOCKET:
 299                 return (VSOCK);
 300         case HAMMER2_OBJTYPE_WHITEOUT:  /* not supported */
 301                 return (DT_UNKNOWN);
 302         default:
 303                 return (DT_UNKNOWN);
 304         }
 305         /* not reached */
 306 }
 307
 308 u_int8_t
 309 hammer2_get_obj_type(enum vtype vtype)
 310 {
 311         switch(vtype) {
 312         case VDIR:
 313                 return(HAMMER2_OBJTYPE_DIRECTORY);
 314         case VREG:
 315                 return(HAMMER2_OBJTYPE_REGFILE);
 316         case VFIFO:
 317                 return(HAMMER2_OBJTYPE_FIFO);
 318         case VSOCK:
 319                 return(HAMMER2_OBJTYPE_SOCKET);
 320         case VCHR:
 321                 return(HAMMER2_OBJTYPE_CDEV);
 322         case VBLK:
 323                 return(HAMMER2_OBJTYPE_BDEV);
 324         case VLNK:
 325                 return(HAMMER2_OBJTYPE_SOFTLINK);
 326         default:
 327                 return(HAMMER2_OBJTYPE_UNKNOWN);
 328         }
 329         /* not reached */
 330 }
 331
 332 /*
 333  * Convert a hammer2 64-bit time to a timespec.
 334  */
 335 void
 336 hammer2_time_to_timespec(u_int64_t xtime, struct timespec *ts)
 337 {
 338         ts->tv_sec = (unsigned long)(xtime / 1000000);
 339         ts->tv_nsec = (unsigned int)(xtime % 1000000) * 1000L;
 340 }
 341
 342 u_int64_t
 343 hammer2_timespec_to_time(struct timespec *ts)
 344 {
 345         u_int64_t xtime;
 346
 347         xtime = (unsigned)(ts->tv_nsec / 1000) +
 348                 (unsigned long)ts->tv_sec * 1000000ULL;
 349         return(xtime);
 350 }
 351
 352 /*
 353  * Convert a uuid to a unix uid or gid
 354  */
 355 u_int32_t
 356 hammer2_to_unix_xid(uuid_t *uuid)
 357 {
 358         return(*(u_int32_t *)&uuid->node[2]);
 359 }
 360
 361 void
 362 hammer2_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 363 {
 364         bzero(uuid, sizeof(*uuid));
 365         *(u_int32_t *)&uuid->node[2] = guid;
 366 }
 367
 368 /*
 369  * Borrow HAMMER1's directory hash algorithm #1 with a few modifications.
 370  * The filename is split into fields which are hashed separately and then
 371  * added together.
 372  *
 373  * Differences include: bit 63 must be set to 1 for HAMMER2 (HAMMER1 sets
 374  * it to 0), this is because bit63=0 is used for hidden hardlinked inodes.
 375  * (This means we do not need to do a 0-check/or-with-0x100000000 either).
 376  *
 377  * Also, the iscsi crc code is used instead of the old crc32 code.
 378  */
 379 hammer2_key_t
 380 hammer2_dirhash(const unsigned char *name, size_t len)
 381 {
 382         const unsigned char *aname = name;
 383         uint32_t crcx;
 384         uint64_t key;
 385         size_t i;
 386         size_t j;
 387
 388         key = 0;
 389
 390         /*
 391          * m32
 392          */
 393         crcx = 0;
 394         for (i = j = 0; i < len; ++i) {
 395                 if (aname[i] == '.' ||
 396                     aname[i] == '-' ||
 397                     aname[i] == '_' ||
 398                     aname[i] == '~') {
 399                         if (i != j)
 400                                 crcx += hammer2_icrc32(aname + j, i - j);
 401                         j = i + 1;
 402                 }
 403         }
 404         if (i != j)
 405                 crcx += hammer2_icrc32(aname + j, i - j);
 406
 407         /*
 408          * The directory hash utilizes the top 32 bits of the 64-bit key.
 409          * Bit 63 must be set to 1.
 410          */
 411         crcx |= 0x80000000U;
 412         key |= (uint64_t)crcx << 32;
 413
 414         /*
 415          * l16 - crc of entire filename
 416          *
 417          * This crc reduces degenerate hash collision conditions
 418          */
 419         crcx = hammer2_icrc32(aname, len);
 420         crcx = crcx ^ (crcx << 16);
 421         key |= crcx & 0xFFFF0000U;
 422
 423         /*
 424          * Set bit 15.  This allows readdir to strip bit 63 so a positive
 425          * 64-bit cookie/offset can always be returned, and still guarantee
 426          * that the values 0x0000-0x7FFF are available for artificial entries.
 427          * ('.' and '..').
 428          */
 429         key |= 0x8000U;
 430
 431         return (key);
 432 }
 433
 434 /*
 435  * Return the power-of-2 radix greater or equal to
 436  * the specified number of bytes.
 437  *
 438  * Always returns at least the minimum media allocation
 439  * size radix, HAMMER2_MIN_RADIX (10), which is 1KB.
 440  */
 441 int
 442 hammer2_allocsize(size_t bytes)
 443 {
 444         int radix;
 445
 446         if (bytes < HAMMER2_MIN_ALLOC)
 447                 bytes = HAMMER2_MIN_ALLOC;
 448         if (bytes == HAMMER2_PBUFSIZE)
 449                 radix = HAMMER2_PBUFRADIX;
 450         else if (bytes >= 16384)
 451                 radix = 14;
 452         else if (bytes >= 1024)
 453                 radix = 10;
 454         else
 455                 radix = HAMMER2_MIN_RADIX;
 456
 457         while (((size_t)1 << radix) < bytes)
 458                 ++radix;
 459         return (radix);
 460 }
 461
 462 /*
 463  * ip must be locked sh/ex
 464  */
 465 int
 466 hammer2_calc_logical(hammer2_inode_t *ip, hammer2_off_t uoff,
 467                      hammer2_key_t *lbasep, hammer2_key_t *leofp)
 468 {
 469         hammer2_inode_data_t *ipdata = &ip->chain->data->ipdata;
 470         int radix;
 471
 472         *lbasep = uoff & ~HAMMER2_PBUFMASK64;
 473         *leofp = ipdata->size & ~HAMMER2_PBUFMASK64;
 474         KKASSERT(*lbasep <= *leofp);
 475         if (*lbasep == *leofp /*&& *leofp < 1024 * 1024*/) {
 476                 radix = hammer2_allocsize((size_t)(ipdata->size - *leofp));
 477                 if (radix < HAMMER2_MINALLOCRADIX)
 478                         radix = HAMMER2_MINALLOCRADIX;
 479                 *leofp += 1U << radix;
 480                 return (1U << radix);
 481         } else {
 482                 return (HAMMER2_PBUFSIZE);
 483         }
 484 }
 485
 486 void
 487 hammer2_update_time(uint64_t *timep)
 488 {
 489         struct timeval tv;
 490
 491         getmicrotime(&tv);
 492         *timep = (unsigned long)tv.tv_sec * 1000000 + tv.tv_usec;
 493 }