+# let's start slowly here...
+START=`date +%s`
+log "touching $MOUNT at `date`"
+touch $MOUNT || error "can't touch $MOUNT" 2
+HOSTS=$MOUNT/hosts.$$
+TRUNCSIZE=123
+
+if [ $COUNT -gt 10 -o $COUNT -eq 0 ]; then
+ # this will cause the following cp to trigger bug #620096
+ log "create an empty file $HOSTS"
+ mcreate $HOSTS
+ log "copying /etc/hosts to $HOSTS"
+ cp /etc/hosts $HOSTS || error "can't cp /etc/hosts to $HOSTS" 3
+ log "comparing /etc/hosts and $HOSTS"
+ diff -u /etc/hosts $HOSTS || error "$HOSTS different" 4
+ log "renaming $HOSTS to $HOSTS.ren"
+ mv $HOSTS $HOSTS.ren || error "can't rename $HOSTS to $HOSTS.ren" 5
+ log "copying /etc/hosts to $HOSTS again"
+ cp /etc/hosts $HOSTS || error "can't cp /etc/hosts to $HOSTS again" 6
+ log "truncating $HOSTS"
+ > $HOSTS || error "can't truncate $HOSTS" 8
+ log "removing $HOSTS"
+ rm $HOSTS || error "can't remove $HOSTS" 9
+ cp /etc/hosts $HOSTS.2 || error "can't cp /etc/hosts to $HOSTS.2" 7
+ log "truncating $HOSTS.2 to $TRUNCSIZE bytes"
+ $TRUNCATE $HOSTS.2 $TRUNCSIZE
+fi
+
+DST=$MOUNT/runtest.$$
+# let's start slowly here...
+log "creating $DST"
+mkdir $DST || error "can't mkdir $DST" 10
+
+# ok, that hopefully worked, so let's do a little more, with files that
+# haven't changed in the last day (hopefully they don't change during test)
+FILES=$TMP/runtests.files
+# use "NUL" instead of newline as filename terminator, bug 19702
+find $RUNTESTS_SRC -type f -mtime +1 | head -n $COUNT | tr '\n' '\0' > $FILES
+[ -s "$FILES" ] ||
+ error "$RUNTESTS_SRC contains only files modifed less than 2 days ago"
+COUNT=$(xargs -0 -n 1 echo < $FILES | wc -l)
+
+log "copying $COUNT files from $RUNTESTS_SRC to $DST$RUNTESTS_SRC at `date`"
+tar cf - --null --files-from $FILES | tar xvf - -C $DST > /dev/null ||
+ error "copying $RUNTESTS_SRC" 11
+
+log "comparing $COUNT newly copied files at `date`"
+
+cat $FILES | tr "\0" "\n" | ( rc=0; while read f; do
+ [ $V ] && log "verifying $DST/$f"
+ diff -q "$f" "$DST/$f" || rc=11