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 1.7 2007/11/27 07:48:52 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         ++lock->lockcount;
  60         crit_exit();
  61 }
  62
  63 /*
  64  * Try to obtain an exclusive lock
  65  */
  66 int
  67 hammer_lock_ex_try(struct hammer_lock *lock)
  68 {
  69         thread_t td = curthread;
  70
  71         KKASSERT(lock->refs > 0);
  72         crit_enter();
  73         if (lock->locktd != td) {
  74                 if (lock->locktd != NULL || lock->lockcount)
  75                         return(EAGAIN);
  76                 lock->locktd = td;
  77         }
  78         ++lock->lockcount;
  79         crit_exit();
  80         return(0);
  81 }
  82
  83
  84 void
  85 hammer_lock_sh(struct hammer_lock *lock)
  86 {
  87         KKASSERT(lock->refs > 0);
  88         crit_enter();
  89         while (lock->locktd != NULL) {
  90                 if (lock->locktd == curthread) {
  91                         ++lock->lockcount;
  92                         crit_exit();
  93                         return;
  94                 }
  95                 lock->wanted = 1;
  96                 tsleep(lock, 0, "hmrlck", 0);
  97         }
  98         KKASSERT(lock->lockcount <= 0);
  99         --lock->lockcount;
 100         crit_exit();
 101 }
 102
 103 void
 104 hammer_downgrade(struct hammer_lock *lock)
 105 {
 106         KKASSERT(lock->lockcount == 1);
 107         crit_enter();
 108         lock->lockcount = -1;
 109         lock->locktd = NULL;
 110         if (lock->wanted) {
 111                 lock->wanted = 0;
 112                 wakeup(lock);
 113         }
 114         crit_exit();
 115         /* XXX memory barrier */
 116 }
 117
 118 void
 119 hammer_unlock(struct hammer_lock *lock)
 120 {
 121         crit_enter();
 122         KKASSERT(lock->lockcount != 0);
 123         if (lock->lockcount < 0) {
 124                 if (++lock->lockcount == 0 && lock->wanted) {
 125                         lock->wanted = 0;
 126                         wakeup(lock);
 127                 }
 128         } else {
 129                 KKASSERT(lock->locktd == curthread);
 130                 if (--lock->lockcount == 0) {
 131                         lock->locktd = NULL;
 132                         if (lock->wanted) {
 133                                 lock->wanted = 0;
 134                                 wakeup(lock);
 135                         }
 136                 }
 137
 138         }
 139         crit_exit();
 140 }
 141
 142 void
 143 hammer_ref(struct hammer_lock *lock)
 144 {
 145         crit_enter();
 146         ++lock->refs;
 147         crit_exit();
 148 }
 149
 150 void
 151 hammer_unref(struct hammer_lock *lock)
 152 {
 153         crit_enter();
 154         KKASSERT(lock->refs > 0);
 155         --lock->refs;
 156         crit_exit();
 157 }
 158
 159 u_int32_t
 160 hammer_to_unix_xid(uuid_t *uuid)
 161 {
 162         return(*(u_int32_t *)&uuid->node[2]);
 163 }
 164
 165 void
 166 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
 167 {
 168         bzero(uuid, sizeof(*uuid));
 169         *(u_int32_t *)&uuid->node[2] = guid;
 170 }
 171
 172 void
 173 hammer_to_timespec(hammer_tid_t tid, struct timespec *ts)
 174 {
 175         ts->tv_sec = tid / 1000000000;
 176         ts->tv_nsec = tid % 1000000000;
 177 }
 178
 179 hammer_tid_t
 180 hammer_timespec_to_transid(struct timespec *ts)
 181 {
 182         hammer_tid_t tid;
 183
 184         tid = ts->tv_nsec + (unsigned long)ts->tv_sec * 1000000000LL;
 185         return(tid);
 186 }
 187
 188
 189 /*
 190  * Convert a HAMMER filesystem object type to a vnode type
 191  */
 192 enum vtype
 193 hammer_get_vnode_type(u_int8_t obj_type)
 194 {
 195         switch(obj_type) {
 196         case HAMMER_OBJTYPE_DIRECTORY:
 197                 return(VDIR);
 198         case HAMMER_OBJTYPE_REGFILE:
 199                 return(VREG);
 200         case HAMMER_OBJTYPE_DBFILE:
 201                 return(VDATABASE);
 202         case HAMMER_OBJTYPE_FIFO:
 203                 return(VFIFO);
 204         case HAMMER_OBJTYPE_CDEV:
 205                 return(VCHR);
 206         case HAMMER_OBJTYPE_BDEV:
 207                 return(VBLK);
 208         case HAMMER_OBJTYPE_SOFTLINK:
 209                 return(VLNK);
 210         default:
 211                 return(VBAD);
 212         }
 213         /* not reached */
 214 }
 215
 216 int
 217 hammer_get_dtype(u_int8_t obj_type)
 218 {
 219         switch(obj_type) {
 220         case HAMMER_OBJTYPE_DIRECTORY:
 221                 return(DT_DIR);
 222         case HAMMER_OBJTYPE_REGFILE:
 223                 return(DT_REG);
 224         case HAMMER_OBJTYPE_DBFILE:
 225                 return(DT_DBF);
 226         case HAMMER_OBJTYPE_FIFO:
 227                 return(DT_FIFO);
 228         case HAMMER_OBJTYPE_CDEV:
 229                 return(DT_CHR);
 230         case HAMMER_OBJTYPE_BDEV:
 231                 return(DT_BLK);
 232         case HAMMER_OBJTYPE_SOFTLINK:
 233                 return(DT_LNK);
 234         default:
 235                 return(DT_UNKNOWN);
 236         }
 237         /* not reached */
 238 }
 239
 240 u_int8_t
 241 hammer_get_obj_type(enum vtype vtype)
 242 {
 243         switch(vtype) {
 244         case VDIR:
 245                 return(HAMMER_OBJTYPE_DIRECTORY);
 246         case VREG:
 247                 return(HAMMER_OBJTYPE_REGFILE);
 248         case VDATABASE:
 249                 return(HAMMER_OBJTYPE_DBFILE);
 250         case VFIFO:
 251                 return(HAMMER_OBJTYPE_FIFO);
 252         case VCHR:
 253                 return(HAMMER_OBJTYPE_CDEV);
 254         case VBLK:
 255                 return(HAMMER_OBJTYPE_BDEV);
 256         case VLNK:
 257                 return(HAMMER_OBJTYPE_SOFTLINK);
 258         default:
 259                 return(HAMMER_OBJTYPE_UNKNOWN);
 260         }
 261         /* not reached */
 262 }
 263
 264 /*
 265  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
 266  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
 267  * generate a unique key and will scan all entries with the same upper
 268  * 32 bits when issuing a lookup.
 269  *
 270  * We strip bit 63 in order to provide a positive key, this way a seek
 271  * offset of 0 will represent the base of the directory.
 272  */
 273 int64_t
 274 hammer_directory_namekey(void *name, int len)
 275 {
 276         int64_t key;
 277
 278         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
 279         return(key);
 280 }
 281
 282 hammer_tid_t
 283 hammer_now_tid(void)
 284 {
 285         struct timespec ts;
 286         hammer_tid_t tid;
 287
 288         getnanotime(&ts);
 289         tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
 290         return(tid);
 291 }
 292