xref: /netbsd-src/external/bsd/am-utils/dist/amd/srvr_amfs_auto.c (revision 8bae5d409deb915cf7c8f0539fae22ff2cb8a313)
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 *
amfs_generic_find_srvr(mntfs * mf)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
wakeup_srvr(fserver * fs)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
timeout_srvr(voidp v)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
free_srvr(fserver * fs)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 *
dup_srvr(fserver * fs)193 dup_srvr(fserver *fs)
194 {
195   fs->fs_refc++;
196   return fs;
197 }
198 
199 
200 /*
201  * Log state change
202  */
203 void
srvrlog(fserver * fs,char * state)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