ctdb-scripts: Add exportfs cache to NFS Linux kernel callout
[obnox/samba/samba-obnox.git] / ctdb / config / nfs-linux-kernel-callout
1 #!/bin/sh
2
3 # Exit on 1st error
4 set -e
5
6 # NFS exports file.  Some code below keeps a cache of output derived
7 # from exportfs(8).  When this file is updated the cache is invalid
8 # and needs to be regenerated.
9 #
10 # To change the file, edit the default value below.  Do not set
11 # CTDB_NFS_EXPORTS_FILE - it isn't a configuration variable, just a
12 # hook for testing.
13 nfs_exports_file="${CTDB_NFS_EXPORTS_FILE:-/var/lib/nfs/etab}"
14
15 # Red Hat
16 nfs_service="nfs"
17 nfslock_service="nfslock"
18 nfs_config="/etc/sysconfig/nfs"
19
20 # SUSE
21 #nfs_service="nfsserver"
22 #nfslock_service=""
23 #nfs_config="/etc/sysconfig/nfs"
24
25 # Debian
26 #nfs_service="nfs-kernel-server"
27 #nfslock_service=""
28 #nfs_config="/etc/default/nfs-kernel-server"
29
30 # Override for unit testing
31 if [ -z "$PROCFS_PATH" ] ; then
32     PROCFS_PATH="/proc"
33 fi
34
35 ##################################################
36
37 usage ()
38 {
39     _c=$(basename $0)
40     cat <<EOF
41 usage: $_c { shutdown | startup }
42        $_c { stop | start } { nfs | nlockmgr }
43        $_c { monitor-list-shares | monitor-post }
44        $_c { register }
45 EOF
46     exit 1
47 }
48
49
50 ##################################################
51 # Basic service stop and start
52
53 basic_stop ()
54 {
55     case "$1" in
56         nfs)
57             service "$nfs_service" stop
58             if [ -n "$nfslock_service" ] ; then
59                 service "$nfslock_service" stop
60             fi
61             ;;
62         nfslock)
63             if [ -n "$nfslock_service" ] ; then
64                 service "$nfslock_service" stop
65             else
66                 service "$nfs_service" stop
67             fi
68             ;;
69         *)
70             usage
71     esac
72 }
73
74 basic_start ()
75 {
76     case "$1" in
77         nfs)
78             if [ -n "$nfslock_service" ] ; then
79                 service "$nfslock_service" start
80             fi
81             service "$nfs_service" start
82             ;;
83         nfslock)
84             if [ -n "$nfslock_service" ] ; then
85                 service "$nfslock_service" start
86             else
87                 service "$nfs_service" start
88             fi
89             ;;
90         *)
91             usage
92     esac
93 }
94
95 ##################################################
96 # service "stop" and "start" options for restarting
97
98 service_stop ()
99 {
100     case "$1" in
101         nfs)
102             echo 0 >"${PROCFS_PATH}/fs/nfsd/threads"
103             basic_stop "nfs" >/dev/null 2>&1 || true
104             pkill -9 nfsd
105             ;;
106         nlockmgr)
107             basic_stop "nfslock" >/dev/null 2>&1 || true
108             ;;
109         *)
110             usage
111     esac
112 }
113
114 service_start ()
115 {
116     case "$1" in
117         nfs)
118             basic_start "nfs"
119             ;;
120         nlockmgr)
121             basic_start "nfslock"
122             ;;
123         *)
124             usage
125     esac
126 }
127
128 ##################################################
129 # service init startup and final shutdown
130
131 nfs_shutdown ()
132 {
133     basic_stop "nfs"
134 }
135
136 nfs_startup ()
137 {
138     basic_stop "nfs" || true
139     basic_start "nfs"
140     _f="${PROCFS_PATH}/sys/net/ipv4/tcp_tw_recycle"
141     if [ "$_f" ] ; then
142         echo 1 >"$_f"
143     fi
144 }
145
146 ##################################################
147 # monitor-post support
148
149 nfs_check_thread_count ()
150 {
151     # Load NFS configuration to get desired number of threads.
152     if [ -r "$nfs_config" ] ; then
153         . "$nfs_config"
154     fi
155
156     # If $RPCNFSDCOUNT/$USE_KERNEL_NFSD_NUMBER isn't set then we could
157     # guess the default from the initscript.  However, let's just
158     # assume that those using the default don't care about the number
159     # of threads and that they have switched on this feature in error.
160     _configured_threads="${RPCNFSDCOUNT:-${USE_KERNEL_NFSD_NUMBER}}"
161     [ -n "$_configured_threads" ] || return 0
162
163     _threads_file="${PROCFS_PATH}/fs/nfsd/threads"
164
165     # nfsd should be running the configured number of threads.  If
166     # there are a different number of threads then tell nfsd the
167     # correct number.
168     read _running_threads <"$_threads_file"
169     # Intentionally not arithmetic comparison - avoids extra errors
170     # when above fails...
171     if [ "$_running_threads" != "$_configured_threads" ] ; then
172         echo "Attempting to correct number of nfsd threads from ${_running_threads} to ${_configured_threads}"
173         echo "$_configured_threads" >"$_threads_file"
174     fi
175 }
176
177 ##################################################
178 # list share directories
179
180 nfs_monitor_list_shares ()
181 {
182     _cache_file="${CTDB_NFS_CALLOUT_STATE_DIR}/list_shares_cache"
183     if  [ ! -r "$nfs_exports_file" ] || [ ! -r "$_cache_file" ] || \
184             [ "$nfs_exports_file" -nt "$_cache_file" ] ; then
185         mkdir -p "$CTDB_NFS_CALLOUT_STATE_DIR"
186         # We could just use the contents of $nfs_exports_file.
187         # However, let's regard that file as internal to NFS and use
188         # exportfs, which is the public API.
189         if ! _exports=$(exportfs -v) ; then
190             echo "WARNING: failed to run exportfs to list NFS shares" >&2
191             return
192         fi
193
194         echo "$_exports" |
195             grep '^/' |
196             sed -e 's@[[:space:]][[:space:]]*[^[:space:]()][^[:space:]()]*([^[:space:]()][^[:space:]()]*)$@@' |
197             sort -u >"$_cache_file"
198     fi
199
200     cat "$_cache_file"
201 }
202
203 ##################################################
204
205 nfs_register ()
206 {
207     cat <<EOF
208 shutdown
209 startup
210 stop
211 start
212 monitor-list-shares
213 monitor-post
214 EOF
215 }
216
217 ##################################################
218
219 case "$1" in
220     shutdown)
221         nfs_shutdown
222         ;;
223     startup)
224         nfs_startup
225         ;;
226     stop)
227         service_stop "$2"
228         ;;
229     start)
230         service_start "$2"
231         ;;
232     monitor-list-shares)
233         nfs_monitor_list_shares
234         ;;
235     monitor-post)
236         nfs_check_thread_count
237         ;;
238     register)
239         nfs_register
240         ;;
241     monitor-pre|releaseip|takeip)
242         # Not required/implemented
243         :
244         ;;
245     *)
246         usage
247 esac