mdcheck: reset sync_action to "idle" when stopped

When the mdcheck script stops because the pre-set duration is exceeded, it
will also set the sync action in the kernel to "idle". But when it is
stopped by a signal (e.g. when the systemd service running it is stopped),
it doesn't.  This is inconsistent behavior.

Move the code that switches the sync_action to "idle" into a cleanup
function that is always executed on exit. This requires separate "trap"
statements for EXIT(0) and signals, because otherwise a race condition may
arise between the cleanup code and the script body.

Signed-off-by: Martin Wilck <mwilck@suse.com>

diff --git a/misc/mdcheck b/misc/mdcheck
index 5f068121b924540210a0414c4f013185f7128d3f..aa2096612e560508bc4ed7796b7f4f49f343635e 100644 (file)
--- a/misc/mdcheck
+++ b/misc/mdcheck
@@ -66,15 +66,40 @@ shift
 
 # We need a temp file occasionally...
 tmp=/var/lib/mdcheck/.md-check-$$
-trap 'rm -f "$tmp"' 0 2 3 15
+cnt=0
+
+cleanup() {
+    # We've waited, and there are still checks running.
+    # Time to stop them.
+    for i in `eval echo {1..$cnt}`
+    do
+       eval fl=\$MD_${i}_fl
+       eval sys=\$MD_${i}_sys
+       eval dev=\$MD_${i}_dev
+
+       if [ -z "$fl" ]; then continue; fi
+
+       if [ "`cat $sys/md/sync_action`" != 'check' ]
+       then
+           eval MD_${i}_fl=
+           rm -f $fl
+           continue;
+       fi
+       echo idle > $sys/md/sync_action
+       cat $sys/md/sync_min > $fl
+       logger -p daemon.info pause checking $dev at `cat $fl`
+    done
+    rm -f "$tmp"
+}
 
+trap 'exit 129' 2 3 15
+trap 'cleanup' 0
 
 # firstly, clean out really old state files
 mkdir -p /var/lib/mdcheck
 find /var/lib/mdcheck -name "MD_UUID*" -type f -mtime +180 -exec rm {} \;
 
 # Now look at each md device.
-cnt=0
 for dev in /dev/md?*
 do
        [ -e "$dev" ] || continue
@@ -149,24 +174,3 @@ do
        fi
        sleep 220
 done
-
-# We've waited, and there are still checks running.
-# Time to stop them.
-for i in `eval echo {1..$cnt}`
-do
-       eval fl=\$MD_${i}_fl
-       eval sys=\$MD_${i}_sys
-       eval dev=\$MD_${i}_dev
-
-       if [ -z "$fl" ]; then continue; fi
-
-       if [ "`cat $sys/md/sync_action`" != 'check' ]
-       then
-               eval MD_${i}_fl=
-               rm -f $fl
-               continue;
-       fi
-       echo idle > $sys/md/sync_action
-       cat $sys/md/sync_min > $fl
-       logger -p daemon.info pause checking $dev at `cat $fl`
-done