common/rc,fio: factor out _compare_three_version_numbers()

The helper functions _have_kver() and _have_fio_ver() have the common
logic that compares three numbers with the version string in the format
"a.b.c". Factor out the common logic to the new helper function
_compare_three_version_numbers(). This prepares for to introduce more
functions for version checks.

Signed-off-by: Shin'ichiro Kawasaki <[email protected]>

Author: kawasaki

common/fio

@@ -28,14 +28,11 @@ _have_fio_zbd_zonemode() {
 
 # Check whether the version of the fio is greater than or equal to $1.$2.$3
 _have_fio_ver() {
-	local d=$1 e=$2 f=$3
-
 	_have_fio || return $?
 
-	IFS='.' read -r a b c < <(fio --version | cut -c 5- | sed 's/-.*//')
-	if [ $((a * 65536 + b * 256 + c)) -lt $((d * 65536 + e * 256 + f)) ];
-	then
-		SKIP_REASONS+=("fio version too old")
+	if _compare_three_version_numbers \
+	     "$(fio --version | cut -c 5- | sed 's/-.*//')" "$1" "$2" "$3"; then
+		SKIP_REASONS+=("fio version is older than ${1}.${2}.${3:-0}")
 		return 1
 	fi
 	return 0

common/rc

@@ -226,15 +226,28 @@ _have_kernel_option() {
 	return 0
 }
 
+# Compare the version string in $1 in "a.b.c" format with "$2.$3.$4".
+# If "a.b.c" is smaller than "$2.$3.$4", return true. Otherwise, return
+# false.
+_compare_three_version_numbers() {
+	local -i a b c d e f
+
+	IFS='.' read -r a b c <<< "$1"
+	d=${2:0}
+	e=${3:0}
+	f=${4:0}
+	if ((a * 65536 + b * 256 + c < d * 65536 + e * 256 + f)); then
+		return 0
+	fi
+	return 1
+}
+
 # Check whether the version of the running kernel is greater than or equal to
 # $1.$2.$3
 _have_kver() {
-	local d=$1 e=$2 f=$3
-
-	IFS='.' read -r a b c < <(uname -r | sed 's/-.*//;s/[^.0-9]//')
-	if [ $((a * 65536 + b * 256 + c)) -lt $((d * 65536 + e * 256 + f)) ];
-	then
-		SKIP_REASONS+=("Kernel version too old")
+	if _compare_three_version_numbers \
+	     "$(uname -r | sed 's/-.*//;s/[^.0-9]//')" "$1" "$2" "$3"; then
+		SKIP_REASONS+=("Kernel version is older than ${1}.${2}.${3}")
 		return 1
 	fi
 }