tests: factor out dl-linux-tarball.bash

This will be also used by the reverse benchmarks.

tests/canonical-benchmarks.bash

@@ -6,24 +6,20 @@
 #
 # This is called by the top-level script "benchmark.bash".
 
+cd "$(dirname "$0")"
+MYNAME=$(basename "$0")
+
 if [ $# -ne 1 ]; then
-	MYNAME=$(basename $0)
 	echo "usage: $MYNAME TESTDIR"
 	exit 1
 fi
 
+# Download /tmp/linux-3.0.tar.gz
+./dl-linux-tarball.bash
+
 # cd to TESTDIR
 cd "$1"
 
-TGZ=/tmp/linux-3.0.tar.gz
-
-if [ "$(md5sum /tmp/linux-3.0.tar.gz | cut -f1 -d' ')" != \
-	"f7e6591d86a9dbe123dfd1a0be054e7f" ]; then
-	echo "Downloading linux-3.0.tar.gz"
-	wget -nv --show-progress -c -O $TGZ \
-		https://cdn.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
-fi
-
 function etime {
 	LC_ALL=C /usr/bin/time -f %e 2>&1 $@ > /dev/null
 }
@@ -33,7 +29,7 @@ dd if=/dev/zero of=zero bs=131072 count=2000 2>&1 | tail -n 1
 rm zero
 sleep 1
 echo -n "UNTAR: "
-etime tar xzf $TGZ
+etime tar xzf /tmp/linux-3.0.tar.gz
 sleep 1
 echo -n "LS:    "
 etime ls -lR linux-3.0

tests/dl-linux-tarball.bash

@@ -0,0 +1,15 @@
+#!/bin/bash -eu
+#
+# This script checks the MD5 sum of /tmp/linux-3.0.tar.gz and downloads
+# a fresh copy if its incorrect or the file is missing.
+
+TGZ=/tmp/linux-3.0.tar.gz
+
+MD5_ACTUAL="$(md5sum $TGZ | cut -f1 -d' ')"
+MD5_WANT="f7e6591d86a9dbe123dfd1a0be054e7f"
+
+if [[ $MD5_ACTUAL != $MD5_WANT ]]; then
+	echo "Downloading linux-3.0.tar.gz"
+	wget -nv --show-progress -c -O $TGZ \
+		https://cdn.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
+fi