Disable nbmand tests on kernels w/o support

This change allows mountpoint_003_pos and send-c_props
to run on Linux kernels that do not support mandatory
locking. Linux kernel versions greater than or equal to
4.4 no longer support mandatory locking and the test
suite will now account for that.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes #6346 
Closes #6347 
Closes #6362

tests/zfs-tests/include/libtest.shlib

@@ -40,6 +40,29 @@ if [ -n "$STF_PATH" ]; then
 	PATH="$STF_PATH"
 fi
 
+# Linux kernel version comparison function
+#
+# $1 Linux version ("4.10", "2.6.32") or blank for installed Linux version
+#
+# Used for comparison: if [ $(linux_version) -ge $(linux_version "2.6.32") ]
+#
+function linux_version
+{
+	typeset ver="$1"
+
+	[[ -z "$ver" ]] && ver=$(uname -r | grep -Eo "^[0-9]+\.[0-9]+\.[0-9]+")
+
+	typeset version=$(echo $ver | cut -d '.' -f 1)
+	typeset major=$(echo $ver | cut -d '.' -f 2)
+	typeset minor=$(echo $ver | cut -d '.' -f 3)
+
+	[[ -z "$version" ]] && version=0
+	[[ -z "$major" ]] && major=0
+	[[ -z "$minor" ]] && minor=0
+
+	echo $((version * 10000 + major * 100 + minor))
+}
+
 # Determine if this is a Linux test system
 #
 # Return 0 if platform Linux, 1 if otherwise

tests/zfs-tests/include/properties.shlib

@@ -91,8 +91,17 @@ function get_rand_large_recsize
 #
 # Functions to toggle on/off properties
 #
-typeset -a binary_props=('atime' 'devices' 'exec' 'nbmand' 'readonly' 'setuid'
+typeset -a binary_props=('atime' 'devices' 'exec' 'readonly' 'setuid' 'xattr'
-    'xattr' 'zoned')
+    'zoned')
+
+if is_linux; then
+	# Only older kernels support non-blocking mandatory locks
+	if [[ $(linux_version) -lt $(linux_version "4.4") ]]; then
+		binary_props+=('nbmand')
+	fi
+else
+	binary_props+=('nbmand')
+fi
 
 function toggle_prop
 {

tests/zfs-tests/tests/functional/cli_root/zfs_set/mountpoint_003_pos.ksh

@@ -67,11 +67,15 @@ if is_linux; then
 	set -A args \
 	"nodev"		"dev"	\
 	"noexec"	"exec"	\
-	"mand"		"nomand"	\
 	"ro"		"rw"	\
 	"nosuid"	"suid"	\
 	"xattr"		"noxattr"	\
 	"atime"		"noatime"
+
+	# Only older kernels support non-blocking mandatory locks
+	if [[ $(linux_version) -lt $(linux_version "4.4") ]]; then
+		args+=("mand" "nomand")
+	fi
 else
 	set -A args \
 	"devices"	"/devices/"	"nodevices"	"/nodevices/"	\