contrib/amd/amd/srvr_amfs_auto.c

   1 /*
   2  * Copyright (c) 1997-1999 Erez Zadok
   3  * Copyright (c) 1989 Jan-Simon Pendry
   4  * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
   5  * Copyright (c) 1989 The Regents of the University of California.
   6  * All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Jan-Simon Pendry at Imperial College, London.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgment:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  *      %W% (Berkeley) %G%
  40  *
  41  * $Id: srvr_amfs_auto.c,v 1.2 1999/01/10 21:53:53 ezk Exp $
  42  *
  43  */
  44
  45 /*
  46  * Automount FS server ("localhost") modeling
  47  */
  48
  49 #ifdef HAVE_CONFIG_H
  50 # include <config.h>
  51 #endif /* HAVE_CONFIG_H */
  52 #include <am_defs.h>
  53 #include <amd.h>
  54
  55 /* globals */
  56 qelem amfs_auto_srvr_list = {&amfs_auto_srvr_list, &amfs_auto_srvr_list};
  57
  58 /* statics */
  59 static fserver *localhost;
  60
  61
  62 /*
  63  * Find an nfs server for the local host
  64  */
  65 fserver *
  66 find_amfs_auto_srvr(mntfs *mf)
  67 {
  68   fserver *fs = localhost;
  69
  70   if (!fs) {
  71     fs = ALLOC(struct fserver);
  72     fs->fs_refc = 0;
  73     fs->fs_host = strdup("localhost");
  74     fs->fs_ip = 0;
  75     fs->fs_cid = 0;
  76     fs->fs_pinger = 0;
  77     fs->fs_flags = FSF_VALID;
  78     fs->fs_type = "local";
  79     fs->fs_private = 0;
  80     fs->fs_prfree = 0;
  81
  82     ins_que(&fs->fs_q, &amfs_auto_srvr_list);
  83
  84     srvrlog(fs, "starts up");
  85
  86     localhost = fs;
  87   }
  88   fs->fs_refc++;
  89
  90   return fs;
  91 }
  92
  93
  94 /*****************************************************************************
  95  *** GENERIC ROUTINES FOLLOW
  96  *****************************************************************************/
  97
  98 /*
  99  * Wakeup anything waiting for this server
 100  */
 101 void
 102 wakeup_srvr(fserver *fs)
 103 {
 104   fs->fs_flags &= ~FSF_WANT;
 105   wakeup((voidp) fs);
 106 }
 107
 108
 109 /*
 110  * Called when final ttl of server has expired
 111  */
 112 static void
 113 timeout_srvr(voidp v)
 114 {
 115   fserver *fs = v;
 116
 117   /*
 118    * If the reference count is still zero then
 119    * we are free to remove this node
 120    */
 121   if (fs->fs_refc == 0) {
 122 #ifdef DEBUG
 123     dlog("Deleting file server %s", fs->fs_host);
 124 #endif /* DEBUG */
 125     if (fs->fs_flags & FSF_WANT)
 126       wakeup_srvr(fs);
 127
 128     /*
 129      * Remove from queue.
 130      */
 131     rem_que(&fs->fs_q);
 132     /*
 133      * (Possibly) call the private free routine.
 134      */
 135     if (fs->fs_private && fs->fs_prfree)
 136       (*fs->fs_prfree) (fs->fs_private);
 137
 138     /*
 139      * Free the net address
 140      */
 141     if (fs->fs_ip)
 142       XFREE(fs->fs_ip);
 143
 144     /*
 145      * Free the host name.
 146      */
 147     XFREE(fs->fs_host);
 148
 149     /*
 150      * Discard the fserver object.
 151      */
 152     XFREE(fs);
 153   }
 154 }
 155
 156
 157 /*
 158  * Free a file server
 159  */
 160 void
 161 free_srvr(fserver *fs)
 162 {
 163   if (--fs->fs_refc == 0) {
 164     /*
 165      * The reference count is now zero,
 166      * so arrange for this node to be
 167      * removed in AM_TTL seconds if no
 168      * other mntfs is referencing it.
 169      */
 170     int ttl = (fs->fs_flags & (FSF_DOWN | FSF_ERROR)) ? 19 : AM_TTL;
 171
 172 #ifdef DEBUG
 173     dlog("Last hard reference to file server %s - will timeout in %ds", fs->fs_host, ttl);
 174 #endif /* DEBUG */
 175     if (fs->fs_cid) {
 176       untimeout(fs->fs_cid);
 177       /*
 178        * Turn off pinging - XXX
 179        */
 180       fs->fs_flags &= ~FSF_PINGING;
 181     }
 182
 183     /*
 184      * Keep structure lying around for a while
 185      */
 186     fs->fs_cid = timeout(ttl, timeout_srvr, (voidp) fs);
 187
 188     /*
 189      * Mark the fileserver down and invalid again
 190      */
 191     fs->fs_flags &= ~FSF_VALID;
 192     fs->fs_flags |= FSF_DOWN;
 193   }
 194 }
 195
 196
 197 /*
 198  * Make a duplicate fserver reference
 199  */
 200 fserver *
 201 dup_srvr(fserver *fs)
 202 {
 203   fs->fs_refc++;
 204   return fs;
 205 }
 206
 207
 208 /*
 209  * Log state change
 210  */
 211 void srvrlog(fserver *fs, char *state)
 212 {
 213   plog(XLOG_INFO, "file server %s type %s %s", fs->fs_host, fs->fs_type, state);
 214 }