run the testparm commands in 50.samba in the background, only running

in the foreground if something fails

(This used to be ctdb commit b1fed105ad780e89a128a611ef0bd659818eeebf)

diff --git a/ctdb/config/events.d/50.samba b/ctdb/config/events.d/50.samba
index 9aa21e2ece030268f81fd8c0eb1223c65e2a1c39..498aa1704ba19aba4d02aff17e0598133a29f3c5 100755 (executable)
--- a/ctdb/config/events.d/50.samba
+++ b/ctdb/config/events.d/50.samba
@@ -17,10 +17,81 @@ shift
     SAMBA_CLEANUP_PERIOD=10
 }
 
+# we keep a cached copy of smb.conf here
+smbconf_cache="$CTDB_BASE/state/samba/smb.conf.cache"
+
+
+#############################################
+# update the smb.conf cache in the foreground
+testparm_foreground_update() {
+    mkdir -p "$CTDB_BASE/state/samba" || exit 1
+    testparm -s 2> /dev/null | egrep -v 'registry.shares.=|include.=' > "$smbconf_cache"
+}
+
+#############################################
+# update the smb.conf cache in the background
+testparm_background_update() {
+    # if the cache doesn't exist, then update in the foreground
+    [ -f $smbconf_cache ] || {
+       testparm_foreground_update
+    }
+    # otherwise do a background update
+    (
+       tmpfile="${smbconf_cache}.$$"
+       testparm -s > $tmpfile 2> /dev/null &
+       # remember the pid of the teamparm process
+       pid="$!"
+       # give it 10 seconds to run
+       timeleft=10
+       while [ $timeleft -gt 0 ]; do
+           timeleft=$(($timeleft - 1))
+           # see if the process still exists
+           kill -0 $pid > /dev/null 2>&1 || {
+               # it doesn't exist, grab its exit status
+               wait $pid
+               [ $? = 0 ] || {
+                   echo "50.samba: smb.conf background update exited with status $?"
+                   rm -f "${tmpfile}"
+                   exit 1
+               }               
+               # put the new smb.conf contents in the cache (atomic rename)
+               # make sure we remove references to the registry while doing 
+               # this to ensure that running testparm on the cache does
+               # not use the registry
+               egrep -v 'registry.shares.=|include.=' < "$tmpfile" > "${tmpfile}.2"
+               rm -f "$tmpfile"
+               mv -f "${tmpfile}.2" "$smbconf_cache" || {
+                   echo "50.samba: failed to update background cache"
+                   rm -f "${tmpfile}.2"
+                   exit 1
+               }
+               exit 0
+           }
+           # keep waiting for testparm to finish
+           sleep 1
+       done
+       # it took more than 10 seconds - kill it off
+       rm -f "${tmpfile}"
+       kill -9 "$pid" > /dev/null 2>&1
+       echo "50.samba: timed out updating smbconf cache in background"
+       exit 1
+    ) &
+}
+
+##################################################
+# show the testparm output using a cached smb.conf 
+# to avoid registry access
+testparm_cat() {
+    [ -f $smbconf_cache ] || {
+       testparm_foreground_update
+    }
+    testparm -s "$smbconf_cache" "$@" 2>/dev/null
+}
+
 # function to see if ctdb manages winbind
 check_ctdb_manages_winbind() {
   [ -z "$CTDB_MANAGES_WINBIND" ] && {
-    secmode=`testparm -s --parameter-name=security 2> /dev/null`
+    secmode=`testparm_cat --parameter-name=security`
     case $secmode in
        ADS|DOMAIN)
            CTDB_MANAGES_WINBIND="yes";
@@ -108,21 +179,26 @@ case $cmd in
                touch $CTDB_BASE/state/samba/periodic_cleanup
        }
 
-       [ "$CTDB_SAMBA_SKIP_CONF_CHECK" != "yes" ] && {
-               testparm -s 2>&1 | egrep '^WARNING|^ERROR|^Unknown' && {
-                       echo "ERROR: testparm shows smb.conf is not clean"
-                       exit 1
-               }
+       testparm_background_update
+
+       testparm_cat | egrep '^WARNING|^ERROR|^Unknown' && {
+           testparm_foreground_update
+           testparm_cat | egrep '^WARNING|^ERROR|^Unknown' && {
+               echo "ERROR: testparm shows smb.conf is not clean"
+               exit 1
+           }
        }
 
-       [ "$CTDB_SAMBA_SKIP_SHARE_CHECK" != "yes" ] && {
-               smb_dirs=`testparm -s 2> /dev/null | egrep '^[[:space:]]*path = '  | cut -d= -f2`
-               ctdb_check_directories "Samba" $smb_dirs        
+       smb_dirs=`testparm_cat | egrep '^[[:space:]]*path = ' | cut -d= -f2`
+       ctdb_check_directories_probe "Samba" $smb_dirs || {
+           testparm_foreground_update
+           smb_dirs=`testparm_cat | egrep '^[[:space:]]*path = ' | cut -d= -f2`
+           ctdb_check_directories "Samba" $smb_dirs
        }
 
        smb_ports="$CTDB_SAMBA_CHECK_PORTS"
        [ -z "$smb_ports" ] && {
-               smb_ports=`testparm -s --parameter-name="smb ports" 2> /dev/null`
+               smb_ports=`testparm_cat --parameter-name="smb ports"`
        }
        ctdb_check_tcp_ports "Samba" $smb_ports