251: make fstrim call a bit more random

To cover cases when fstrim arguments are not block/block group/file
system size aligned, we can be a bit more random. This commit changes
fstrim argument computing to use $RANDOM bash variable in order to have
different minlen, start, len argument settings and change the full fs
fstrim to be called randomly as well.

Also make kill and wait not complain about non existent process, since
it may have already finished before we attempt to kill it and wait for
it. No reason to fail the test.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/251 b/251
index b54e4c369a80b5553fa29fba2b6597266bd43ad0..f46b6e2c6888698b65d0175d96debf3efb32dc71 100755 (executable)
--- a/251
+++ b/251
@@ -54,21 +54,21 @@ _cleanup()
 
 _destroy()
 {
-       kill $pids $fstrim_pid
-       wait $pids $fstrim_pid
+       kill $pids $fstrim_pid 2> /dev/null
+       wait $pids $fstrim_pid 2> /dev/null
        rm -rf $tmp
 }
 
 _destroy_fstrim()
 {
-       kill $fpid
-       wait $fpid
+       kill $fpid 2> /dev/null
+       wait $fpid 2> /dev/null
 }
 
 _fail()
 {
        echo "$1"
-       kill $mypid
+       kill $mypid 2> /dev/null
 }
 
 _check_fstrim_support()
@@ -76,6 +76,16 @@ _check_fstrim_support()
        $here/src/fstrim -l 10M $SCRATCH_MNT &> /dev/null
 }
 
+_guess_max_minlen()
+{
+       mmlen=100000
+       while [ $mmlen -gt 1 ]; do
+               $here/src/fstrim -l $(($mmlen*2))k -m ${mmlen}k $SCRATCH_MNT &> /dev/null && break
+               mmlen=$(($mmlen/2))
+       done
+       echo $mmlen
+}
+
 ##
 # Background FSTRIM loop. We are trimming the device in the loop and for
 # test coverage, we are doing whole device trim followed by several smaller
@@ -85,15 +95,19 @@ fstrim_loop()
 {
        trap "_destroy_fstrim; exit \$status" 2 15
        fsize=$(df | grep $SCRATCH_MNT | grep $SCRATCH_DEV  | awk '{print $2}')
+       mmlen=$(_guess_max_minlen)
 
        while true ; do
-               step=1048576
-               start=0
-               $here/src/fstrim $SCRATCH_MNT &
-               fpid=$!
-               wait $fpid
+               step=$((RANDOM*$RANDOM))
+               minlen=$(((RANDOM*($RANDOM%2+1))%$mmlen))
+               start=$RANDOM
+               if [ $((RANDOM%10)) -gt 7 ]; then
+                       $here/src/fstrim $SCRATCH_MNT &
+                       fpid=$!
+                       wait $fpid
+               fi
                while [ $start -lt $fsize ] ; do
-                       $here/src/fstrim -s ${start}k -l ${step}k $SCRATCH_MNT &
+                       $here/src/fstrim -m ${minlen}k -s ${start}k -l ${step}k $SCRATCH_MNT &
                        fpid=$!
                        wait $fpid
                        start=$(( $start + $step ))