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 1.8 2007/12/30 08:49:20 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                         return(EAGAIN);
  77                 lock->locktd = td;
  78         }
  79         KKASSERT(lock->lockcount >= 0);
  80         ++lock->lockcount;
  81         crit_exit();
  82         return(0);
  83 }
  84
  85 void
  86 hammer_lock_sh(struct hammer_lock *lock)
  87 {
  88         KKASSERT(lock->refs > 0);
  89         crit_enter();
  90         while (lock->locktd != NULL) {
  91                 if (lock->locktd == curthread) {
  92                         ++lock->lockcount;
  93                         crit_exit();
  94                         return;
  95                 }
  96                 lock->wanted = 1;
  97                 tsleep(lock, 0, "hmrlck", 0);
  98         }
  99         KKASSERT(lock->lockcount <= 0);
 100         --lock->lockcount;
 101         crit_exit();
 102 }
 103
 104 void
 105 hammer_downgrade(struct hammer_lock *lock)
 106 {
 107         KKASSERT(lock->lockcount == 1);
 108         crit_enter();
 109         lock->lockcount = -1;
 110         lock->locktd = NULL;
 111         if (lock->wanted) {
 112                 lock->wanted = 0;
 113                 wakeup(lock);
 114         }
 115         crit_exit();
 116         /* XXX memory barrier */
 117 }
 118
 119 void
 120 hammer_unlock(struct hammer_lock *lock)
 121 {
 122         crit_enter();
 123         KKASSERT(lock->lockcount != 0);
 124         if (lock->lockcount < 0) {
 125                 if (++lock->lockcount == 0 && lock->wanted) {
 126                         lock->wanted = 0;
 127                         wakeup(lock);
 128                 }
 129         } else {
 130                 KKASSERT(lock->locktd == curthread);
 131                 if (--lock->lockcount == 0) {
 132                         lock->locktd = NULL;
 133                         if (lock->wanted) {
 134                                 lock->wanted = 0;
 135                                 wakeup(lock);
 136                         }
 137                 }
 138
 139         }
 140         crit_exit();
 141 }
 142
 143 void
 144 hammer_ref(struct hammer_lock *lock)
 145 {
 146         KKASSERT(lock->refs >= 0);
 147         crit_enter();
 148         ++lock->refs;
 149         crit_exit();
 150 }
 151
 152 void
 153 hammer_unref(struct hammer_lock *lock)
 154 {
 155         KKASSERT(lock->refs > 0);
 156         crit_enter();
 157         --lock->refs;
 158         crit_exit();
 159 }
 160
 161 u_int32_t
 162 hammer_to_unix_xid(uuid_t *uuid)
 163 {
 164         return(*(u_int32_t *)&uuid->node[2]);
 165 }
 166
 167 void
 168 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 169 {
 170         bzero(uuid, sizeof(*uuid));
 171         *(u_int32_t *)&uuid->node[2] = guid;
 172 }
 173
 174 void
 175 hammer_to_timespec(hammer_tid_t tid, struct timespec *ts)
 176 {
 177         ts->tv_sec = tid / 1000000000;
 178         ts->tv_nsec = tid % 1000000000;
 179 }
 180
 181 hammer_tid_t
 182 hammer_timespec_to_transid(struct timespec *ts)
 183 {
 184         hammer_tid_t tid;
 185
 186         tid = ts->tv_nsec + (unsigned long)ts->tv_sec * 1000000000LL;
 187         return(tid);
 188 }
 189
 190
 191 /*
 192  * Convert a HAMMER filesystem object type to a vnode type
 193  */
 194 enum vtype
 195 hammer_get_vnode_type(u_int8_t obj_type)
 196 {
 197         switch(obj_type) {
 198         case HAMMER_OBJTYPE_DIRECTORY:
 199                 return(VDIR);
 200         case HAMMER_OBJTYPE_REGFILE:
 201                 return(VREG);
 202         case HAMMER_OBJTYPE_DBFILE:
 203                 return(VDATABASE);
 204         case HAMMER_OBJTYPE_FIFO:
 205                 return(VFIFO);
 206         case HAMMER_OBJTYPE_CDEV:
 207                 return(VCHR);
 208         case HAMMER_OBJTYPE_BDEV:
 209                 return(VBLK);
 210         case HAMMER_OBJTYPE_SOFTLINK:
 211                 return(VLNK);
 212         default:
 213                 return(VBAD);
 214         }
 215         /* not reached */
 216 }
 217
 218 int
 219 hammer_get_dtype(u_int8_t obj_type)
 220 {
 221         switch(obj_type) {
 222         case HAMMER_OBJTYPE_DIRECTORY:
 223                 return(DT_DIR);
 224         case HAMMER_OBJTYPE_REGFILE:
 225                 return(DT_REG);
 226         case HAMMER_OBJTYPE_DBFILE:
 227                 return(DT_DBF);
 228         case HAMMER_OBJTYPE_FIFO:
 229                 return(DT_FIFO);
 230         case HAMMER_OBJTYPE_CDEV:
 231                 return(DT_CHR);
 232         case HAMMER_OBJTYPE_BDEV:
 233                 return(DT_BLK);
 234         case HAMMER_OBJTYPE_SOFTLINK:
 235                 return(DT_LNK);
 236         default:
 237                 return(DT_UNKNOWN);
 238         }
 239         /* not reached */
 240 }
 241
 242 u_int8_t
 243 hammer_get_obj_type(enum vtype vtype)
 244 {
 245         switch(vtype) {
 246         case VDIR:
 247                 return(HAMMER_OBJTYPE_DIRECTORY);
 248         case VREG:
 249                 return(HAMMER_OBJTYPE_REGFILE);
 250         case VDATABASE:
 251                 return(HAMMER_OBJTYPE_DBFILE);
 252         case VFIFO:
 253                 return(HAMMER_OBJTYPE_FIFO);
 254         case VCHR:
 255                 return(HAMMER_OBJTYPE_CDEV);
 256         case VBLK:
 257                 return(HAMMER_OBJTYPE_BDEV);
 258         case VLNK:
 259                 return(HAMMER_OBJTYPE_SOFTLINK);
 260         default:
 261                 return(HAMMER_OBJTYPE_UNKNOWN);
 262         }
 263         /* not reached */
 264 }
 265
 266 /*
 267  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 268  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
 269  * generate a unique key and will scan all entries with the same upper
 270  * 32 bits when issuing a lookup.
 271  *
 272  * We strip bit 63 in order to provide a positive key, this way a seek
 273  * offset of 0 will represent the base of the directory.
 274  */
 275 int64_t
 276 hammer_directory_namekey(void *name, int len)
 277 {
 278         int64_t key;
 279
 280         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
 281         return(key);
 282 }
 283
 284 hammer_tid_t
 285 hammer_now_tid(void)
 286 {
 287         struct timespec ts;
 288         hammer_tid_t tid;
 289
 290         getnanotime(&ts);
 291         tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
 292         return(tid);
 293 }
 294