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      1 /*	$NetBSD: srvr_amfs_auto.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997-2014 Erez Zadok
      5  * Copyright (c) 1989 Jan-Simon Pendry
      6  * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
      7  * Copyright (c) 1989 The Regents of the University of California.
      8  * All rights reserved.
      9  *
     10  * This code is derived from software contributed to Berkeley by
     11  * Jan-Simon Pendry at Imperial College, London.
     12  *
     13  * Redistribution and use in source and binary forms, with or without
     14  * modification, are permitted provided that the following conditions
     15  * are met:
     16  * 1. Redistributions of source code must retain the above copyright
     17  *    notice, this list of conditions and the following disclaimer.
     18  * 2. Redistributions in binary form must reproduce the above copyright
     19  *    notice, this list of conditions and the following disclaimer in the
     20  *    documentation and/or other materials provided with the distribution.
     21  * 3. Neither the name of the University nor the names of its contributors
     22  *    may be used to endorse or promote products derived from this software
     23  *    without specific prior written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     35  * SUCH DAMAGE.
     36  *
     37  *
     38  * File: am-utils/amd/srvr_amfs_auto.c
     39  *
     40  */
     41 
     42 /*
     43  * Automount FS server ("localhost") modeling
     44  */
     45 
     46 #ifdef HAVE_CONFIG_H
     47 # include <config.h>
     48 #endif /* HAVE_CONFIG_H */
     49 #include <am_defs.h>
     50 #include <amd.h>
     51 
     52 /* globals */
     53 
     54 /* statics */
     55 static qelem amfs_auto_srvr_list = {&amfs_auto_srvr_list, &amfs_auto_srvr_list};
     56 static fserver *localhost;
     57 
     58 
     59 /*
     60  * Find an nfs server for the local host
     61  */
     62 fserver *
     63 amfs_generic_find_srvr(mntfs *mf)
     64 {
     65   fserver *fs = localhost;
     66 
     67   if (!fs) {
     68     fs = ALLOC(struct fserver);
     69     fs->fs_refc = 0;
     70     fs->fs_host = xstrdup("localhost");
     71     fs->fs_ip = NULL;
     72     fs->fs_cid = 0;
     73     fs->fs_pinger = AM_PINGER;
     74     fs->fs_flags = FSF_VALID | FSF_PING_UNINIT;
     75     fs->fs_type = "local";
     76     fs->fs_private = NULL;
     77     fs->fs_prfree = NULL;
     78 
     79     ins_que(&fs->fs_q, &amfs_auto_srvr_list);
     80 
     81     srvrlog(fs, "starts up");
     82 
     83     localhost = fs;
     84   }
     85   fs->fs_refc++;
     86 
     87   return fs;
     88 }
     89 
     90 
     91 /*****************************************************************************
     92  *** GENERIC ROUTINES FOLLOW
     93  *****************************************************************************/
     94 
     95 /*
     96  * Wakeup anything waiting for this server
     97  */
     98 void
     99 wakeup_srvr(fserver *fs)
    100 {
    101   fs->fs_flags &= ~FSF_WANT;
    102   wakeup((voidp) fs);
    103 }
    104 
    105 
    106 /*
    107  * Called when final ttl of server has expired
    108  */
    109 static void
    110 timeout_srvr(voidp v)
    111 {
    112   fserver *fs = v;
    113 
    114   /*
    115    * If the reference count is still zero then
    116    * we are free to remove this node
    117    */
    118   if (fs->fs_refc == 0) {
    119     dlog("Deleting file server %s", fs->fs_host);
    120     if (fs->fs_flags & FSF_WANT)
    121       wakeup_srvr(fs);
    122 
    123     /*
    124      * Remove from queue.
    125      */
    126     rem_que(&fs->fs_q);
    127     /*
    128      * (Possibly) call the private free routine.
    129      */
    130     if (fs->fs_private && fs->fs_prfree)
    131       (*fs->fs_prfree) (fs->fs_private);
    132 
    133     /*
    134      * Free the net address
    135      */
    136     XFREE(fs->fs_ip);
    137 
    138     /*
    139      * Free the host name.
    140      */
    141     XFREE(fs->fs_host);
    142 
    143     /*
    144      * Discard the fserver object.
    145      */
    146     XFREE(fs);
    147   }
    148 }
    149 
    150 
    151 /*
    152  * Free a file server
    153  */
    154 void
    155 free_srvr(fserver *fs)
    156 {
    157   if (--fs->fs_refc == 0) {
    158     /*
    159      * The reference count is now zero,
    160      * so arrange for this node to be
    161      * removed in AM_TTL seconds if no
    162      * other mntfs is referencing it.
    163      */
    164     int ttl = (FSRV_ERROR(fs) || FSRV_ISDOWN(fs)) ? 19 : AM_TTL;
    165 
    166     dlog("Last hard reference to file server %s - will timeout in %ds", fs->fs_host, ttl);
    167     if (fs->fs_cid) {
    168       untimeout(fs->fs_cid);
    169       /*
    170        * Turn off pinging - XXX
    171        */
    172       fs->fs_flags &= ~FSF_PINGING;
    173     }
    174 
    175     /*
    176      * Keep structure lying around for a while
    177      */
    178     fs->fs_cid = timeout(ttl, timeout_srvr, (voidp) fs);
    179 
    180     /*
    181      * Mark the fileserver down and invalid again
    182      */
    183     fs->fs_flags &= ~FSF_VALID;
    184     fs->fs_flags |= FSF_DOWN;
    185   }
    186 }
    187 
    188 
    189 /*
    190  * Make a duplicate fserver reference
    191  */
    192 fserver *
    193 dup_srvr(fserver *fs)
    194 {
    195   fs->fs_refc++;
    196   return fs;
    197 }
    198 
    199 
    200 /*
    201  * Log state change
    202  */
    203 void
    204 srvrlog(fserver *fs, char *state)
    205 {
    206   plog(XLOG_INFO, "file server %s, type %s, state %s", fs->fs_host, fs->fs_type, state);
    207 }
    208