sys/vfs/hammer/hammer_subs.c

   1 /*
   2  * Copyright (c) 2007 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 1.11 2008/01/09 00:46:22 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(struct hammer_lock *lock)
  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->wanted = 1;
  53                         kprintf("hammer_lock_ex: held by %p\n", lock->locktd);
  54                         tsleep(lock, 0, "hmrlck", 0);
  55                         kprintf("hammer_lock_ex: try again\n");
  56                 }
  57                 lock->locktd = td;
  58         }
  59         KKASSERT(lock->lockcount >= 0);
  60         ++lock->lockcount;
  61         crit_exit();
  62 }
  63
  64 /*
  65  * Try to obtain an exclusive lock
  66  */
  67 int
  68 hammer_lock_ex_try(struct hammer_lock *lock)
  69 {
  70         thread_t td = curthread;
  71
  72         KKASSERT(lock->refs > 0);
  73         crit_enter();
  74         if (lock->locktd != td) {
  75                 if (lock->locktd != NULL || lock->lockcount) {
  76                         crit_exit();
  77                         return(EAGAIN);
  78                 }
  79                 lock->locktd = td;
  80         }
  81         KKASSERT(lock->lockcount >= 0);
  82         ++lock->lockcount;
  83         crit_exit();
  84         return(0);
  85 }
  86
  87 void
  88 hammer_lock_sh(struct hammer_lock *lock)
  89 {
  90         KKASSERT(lock->refs > 0);
  91         crit_enter();
  92         while (lock->locktd != NULL) {
  93                 if (lock->locktd == curthread) {
  94                         ++lock->lockcount;
  95                         crit_exit();
  96                         return;
  97                 }
  98                 lock->wanted = 1;
  99                 tsleep(lock, 0, "hmrlck", 0);
 100         }
 101         KKASSERT(lock->lockcount <= 0);
 102         --lock->lockcount;
 103         crit_exit();
 104 }
 105
 106 void
 107 hammer_downgrade(struct hammer_lock *lock)
 108 {
 109         KKASSERT(lock->lockcount == 1);
 110         crit_enter();
 111         lock->lockcount = -1;
 112         lock->locktd = NULL;
 113         if (lock->wanted) {
 114                 lock->wanted = 0;
 115                 wakeup(lock);
 116         }
 117         crit_exit();
 118         /* XXX memory barrier */
 119 }
 120
 121 void
 122 hammer_unlock(struct hammer_lock *lock)
 123 {
 124         crit_enter();
 125         KKASSERT(lock->lockcount != 0);
 126         if (lock->lockcount < 0) {
 127                 if (++lock->lockcount == 0 && lock->wanted) {
 128                         lock->wanted = 0;
 129                         wakeup(lock);
 130                 }
 131         } else {
 132                 KKASSERT(lock->locktd == curthread);
 133                 if (--lock->lockcount == 0) {
 134                         lock->locktd = NULL;
 135                         if (lock->wanted) {
 136                                 lock->wanted = 0;
 137                                 wakeup(lock);
 138                         }
 139                 }
 140
 141         }
 142         crit_exit();
 143 }
 144
 145 void
 146 hammer_ref(struct hammer_lock *lock)
 147 {
 148         KKASSERT(lock->refs >= 0);
 149         crit_enter();
 150         ++lock->refs;
 151         crit_exit();
 152 }
 153
 154 void
 155 hammer_unref(struct hammer_lock *lock)
 156 {
 157         KKASSERT(lock->refs > 0);
 158         crit_enter();
 159         --lock->refs;
 160         crit_exit();
 161 }
 162
 163 u_int32_t
 164 hammer_to_unix_xid(uuid_t *uuid)
 165 {
 166         return(*(u_int32_t *)&uuid->node[2]);
 167 }
 168
 169 void
 170 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 171 {
 172         bzero(uuid, sizeof(*uuid));
 173         *(u_int32_t *)&uuid->node[2] = guid;
 174 }
 175
 176 void
 177 hammer_to_timespec(hammer_tid_t tid, struct timespec *ts)
 178 {
 179         ts->tv_sec = tid / 1000000000;
 180         ts->tv_nsec = tid % 1000000000;
 181 }
 182
 183 hammer_tid_t
 184 hammer_timespec_to_transid(struct timespec *ts)
 185 {
 186         hammer_tid_t tid;
 187
 188         tid = ts->tv_nsec + (unsigned long)ts->tv_sec * 1000000000LL;
 189         return(tid);
 190 }
 191
 192
 193 /*
 194  * Convert a HAMMER filesystem object type to a vnode type
 195  */
 196 enum vtype
 197 hammer_get_vnode_type(u_int8_t obj_type)
 198 {
 199         switch(obj_type) {
 200         case HAMMER_OBJTYPE_DIRECTORY:
 201                 return(VDIR);
 202         case HAMMER_OBJTYPE_REGFILE:
 203                 return(VREG);
 204         case HAMMER_OBJTYPE_DBFILE:
 205                 return(VDATABASE);
 206         case HAMMER_OBJTYPE_FIFO:
 207                 return(VFIFO);
 208         case HAMMER_OBJTYPE_CDEV:
 209                 return(VCHR);
 210         case HAMMER_OBJTYPE_BDEV:
 211                 return(VBLK);
 212         case HAMMER_OBJTYPE_SOFTLINK:
 213                 return(VLNK);
 214         default:
 215                 return(VBAD);
 216         }
 217         /* not reached */
 218 }
 219
 220 int
 221 hammer_get_dtype(u_int8_t obj_type)
 222 {
 223         switch(obj_type) {
 224         case HAMMER_OBJTYPE_DIRECTORY:
 225                 return(DT_DIR);
 226         case HAMMER_OBJTYPE_REGFILE:
 227                 return(DT_REG);
 228         case HAMMER_OBJTYPE_DBFILE:
 229                 return(DT_DBF);
 230         case HAMMER_OBJTYPE_FIFO:
 231                 return(DT_FIFO);
 232         case HAMMER_OBJTYPE_CDEV:
 233                 return(DT_CHR);
 234         case HAMMER_OBJTYPE_BDEV:
 235                 return(DT_BLK);
 236         case HAMMER_OBJTYPE_SOFTLINK:
 237                 return(DT_LNK);
 238         default:
 239                 return(DT_UNKNOWN);
 240         }
 241         /* not reached */
 242 }
 243
 244 u_int8_t
 245 hammer_get_obj_type(enum vtype vtype)
 246 {
 247         switch(vtype) {
 248         case VDIR:
 249                 return(HAMMER_OBJTYPE_DIRECTORY);
 250         case VREG:
 251                 return(HAMMER_OBJTYPE_REGFILE);
 252         case VDATABASE:
 253                 return(HAMMER_OBJTYPE_DBFILE);
 254         case VFIFO:
 255                 return(HAMMER_OBJTYPE_FIFO);
 256         case VCHR:
 257                 return(HAMMER_OBJTYPE_CDEV);
 258         case VBLK:
 259                 return(HAMMER_OBJTYPE_BDEV);
 260         case VLNK:
 261                 return(HAMMER_OBJTYPE_SOFTLINK);
 262         default:
 263                 return(HAMMER_OBJTYPE_UNKNOWN);
 264         }
 265         /* not reached */
 266 }
 267
 268 /*
 269  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 270  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
 271  * generate a unique key and will scan all entries with the same upper
 272  * 32 bits when issuing a lookup.
 273  *
 274  * We strip bit 63 in order to provide a positive key, this way a seek
 275  * offset of 0 will represent the base of the directory.
 276  *
 277  * This function can never return 0.  We use the MSB-0 space to synthesize
 278  * artificial directory entries such as "." and "..".
 279  */
 280 int64_t
 281 hammer_directory_namekey(void *name, int len)
 282 {
 283         int64_t key;
 284
 285         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
 286         if (key == 0)
 287                 key |= 0x100000000LL;
 288         return(key);
 289 }
 290
 291 hammer_tid_t
 292 hammer_now_tid(void)
 293 {
 294         struct timespec ts;
 295         hammer_tid_t tid;
 296
 297         getnanotime(&ts);
 298         tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
 299         return(tid);
 300 }
 301
 302 hammer_tid_t
 303 hammer_str_to_tid(const char *str)
 304 {
 305         hammer_tid_t tid;
 306
 307         tid = strtoq(str, NULL, 16) * 1000000000LL;
 308         return(tid);
 309 }
 310