From 09665195439cd83720aebc2115b0636955965e3a Mon Sep 17 00:00:00 2001
From: Lukas Czerner <lczerner@redhat.com>
Date: Thu, 1 Mar 2012 09:15:16 +0100
Subject: [PATCH] 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>
---
 251 | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/251 b/251
index b54e4c36..f46b6e2c 100755
--- 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 ))
-- 
2.39.5