Check for newer mount options in regression test

The mount options MS_LAZYTIME and MS_NOSYMFOLLOW were added in
kernels 4.0 and 5.10, respectively. Update the mount test script
and helper to skip testing those options if they are not available.

Signed-off-by: Jon Tourville <jon.tourville@canonical.com>
(cherry picked from commit 9a760def8d)
Signed-off-by: Jon Tourville <jon.tourville@canonical.com>

tests/regression/apparmor/Makefile

@@ -328,6 +328,9 @@ unix_fd_client: unix_fd_client.c unix_fd_common.o
 attach_disconnected: attach_disconnected.c unix_fd_common.o
 	${CC} ${CFLAGS} ${LDFLAGS} $^ -o $@ ${LDLIBS}
 
+mount: mount.c
+	${CC} ${CFLAGS} -std=gnu99 ${LDFLAGS} $^ -o $@ ${LDLIBS}
+
 build-dep:
 	@if [ `whoami` = "root" ] ;\
 	then \

tests/regression/apparmor/mount.c

@@ -56,8 +56,11 @@ static struct mnt_keyword_table mnt_opts_table[] = {
 	{ "nostrictatime", 0, MS_STRICTATIME }, /* kernel default atime */
 	{ "strictatime",   MS_STRICTATIME, 0 }, /* strict atime semantics */
 
+/* MS_LAZYTIME added in 4.0 kernel */
+#ifdef MS_LAZYTIME
 	{ "nolazytime", 0, MS_LAZYTIME },
 	{ "lazytime",   MS_LAZYTIME, 0 }, /* update {a,m,c}time on the in-memory inode only */
+#endif
 
 	{ "acl",   MS_POSIXACL, 0 },
 	{ "noacl", 0, MS_POSIXACL },
@@ -68,8 +71,11 @@ static struct mnt_keyword_table mnt_opts_table[] = {
 	{ "dirsync", MS_DIRSYNC, 0 }, /* synchronous directory modifications */
 	{ "nodirsync", 0, MS_DIRSYNC },
 
+/* MS_NOSYMFOLLOW added in 5.10 kernel */
+#ifdef MS_NOSYMFOLLOW
 	{ "nosymfollow", MS_NOSYMFOLLOW, 0 },
 	{ "symfollow",   0, MS_NOSYMFOLLOW },
+#endif
 
 	{ "bind",        MS_BIND,                0 }, /* remount part of the tree elsewhere */
 	{ "rbind",       MS_BIND | MS_REC,       0 }, /* idem, plus mounted subtrees */

tests/regression/apparmor/mount.sh

@@ -111,10 +111,14 @@ options=(
 	"noiversion,iversion"
 	"diratime,nodiratime"
 	"nostrictatime,strictatime"
-	"nolazytime,lazytime"
 	"norelatime,relatime"
 	"nodirsync,dirsync"
 	"noacl,acl"
+)
+
+# Options added in newer kernels
+new_options=(
+	"nolazytime,lazytime"
 	"symfollow,nosymfollow"
 )
 
@@ -270,6 +274,17 @@ setup_mnt
 runchecktest "UMOUNT (unconfined)" pass umount ${loop_device} ${mount_point}
 remove_mnt
 
+# Check mount options that may not be available on this kernel
+for i in "${new_options[@]}"; do
+	default="${i%,*}"
+	if "$bin/mount" mount ${loop_device} ${mount_point} -o $default > /dev/null 2>&1; then
+		remove_mnt
+		options+=($i)
+	else
+		echo "    not supported by kernel - skipping mount options=($i),"
+	fi
+done
+
 for i in "${options[@]}"; do
 	default="${i%,*}"
 	nondefault="${i#*,}"