Add basic ACL consistency test case.

This test case is used to detect and reproduce a customer issue we're
seeing where the new .get_acl() method API and underlying changes in
el9_6+ are causing ACL cache fetching to return inconsistent results,
which shows as missing ACLs on directories.

This particular sequence is consistent enough that it warrants making
it into a specific test.

Signed-off-by: Auke Kok <auke.kok@versity.com>

tests/golden/basic-acl-consistency

@@ -0,0 +1,6 @@
+== make scratch fs
+== create uid/gids
+== set acls and permissions
+== compare output
+== drop caches and compare again
+== cleanup scratch fs

tests/sequence

@@ -2,6 +2,7 @@ export-get-name-parent.sh
 basic-block-counts.sh
 basic-bad-mounts.sh
 basic-posix-acl.sh
+basic-acl-consistency.sh
 inode-items-updated.sh
 simple-inode-index.sh
 simple-staging.sh

tests/tests/basic-acl-consistency.sh

@@ -0,0 +1,117 @@
+
+#
+# Test basic clustered posix acl consistency.
+#
+
+t_require_commands getfacl setfacl
+
+GETFACL="getfacl --absolute-names"
+
+filter_scratch() {
+	sed "s@$T_MSCR@t_mscr@g"
+}
+
+acl_compare()
+{
+	diff -u - <($GETFACL $T_MSCR/data/dir_a/dir_b | filter_scratch) <<EOF1
+# file: t_mscr/data/dir_a/dir_b
+# owner: t_usr_3
+# group: t_grp_3
+# flags: -s-
+user::rwx
+group::rwx
+group:t_grp_2:r-x
+mask::rwx
+other::---
+default:user::rwx
+default:group::rwx
+default:group:t_grp_2:r-x
+default:group:t_grp_3:rwx
+default:mask::rwx
+default:other::---
+
+EOF1
+
+	test $? -eq 0 || t_fail "dir_b differs"
+
+	diff -u - <($GETFACL -p $T_MSCR/data/dir_a/dir_b/dir_c/dir_d | filter_scratch) <<EOF3
+# file: t_mscr/data/dir_a/dir_b/dir_c/dir_d
+# owner: t_usr_1
+# group: t_grp_1
+# flags: -s-
+user::rwx
+group::rwx
+group:t_grp_2:r-x
+mask::rwx
+other::---
+default:user::rwx
+default:group::rwx
+default:group:t_grp_2:r-x
+default:group:t_grp_3:rwx
+default:mask::rwx
+default:other::---
+
+EOF3
+	test $? -eq 0 || t_fail "dir_d differs"
+
+	diff -u - <($GETFACL $T_MSCR/data/dir_a/dir_b/dir_c | filter_scratch) <<EOF2
+# file: t_mscr/data/dir_a/dir_b/dir_c
+# owner: t_usr_3
+# group: t_grp_2
+# flags: -s-
+user::rwx
+group::rwx
+group:t_grp_2:r-x
+mask::rwx
+other::---
+default:user::rwx
+default:group::rwx
+default:group:t_grp_2:r-x
+default:group:t_grp_3:rwx
+default:mask::rwx
+default:other::---
+
+EOF2
+	test $? -eq 0 || t_fail "dir_c differs"
+}
+echo "== make scratch fs"
+t_scratch_mkfs
+t_scratch_mount
+
+rm -rf $T_MSCR/data
+
+echo "== create uid/gids"
+groupadd -g 7101 t_grp_1 > /dev/null 2>&1
+useradd -g 7101 -u 7101 t_usr_1 > /dev/null 2>&1
+groupadd -g 7102 t_grp_2 > /dev/null 2>&1
+groupadd -g 7103 t_grp_3 > /dev/null 2>&1
+useradd -g 7103 -u 7103 t_usr_3 > /dev/null 2>&1
+
+echo "== set acls and permissions"
+mkdir -p $T_MSCR/data/dir_a/dir_b
+chown t_usr_3:t_grp_3 $T_MSCR/data/dir_a/dir_b
+chmod 2770 $T_MSCR/data/dir_a/dir_b
+setfacl -m g:t_grp_2:rx $T_MSCR/data/dir_a/dir_b
+setfacl -m d:g:t_grp_2:rx $T_MSCR/data/dir_a/dir_b
+setfacl -m d:g:t_grp_3:rwx $T_MSCR/data/dir_a/dir_b
+
+mkdir -p $T_MSCR/data/dir_a/dir_b/dir_c
+chown t_usr_3:t_grp_2 $T_MSCR/data/dir_a/dir_b/dir_c
+setfacl -x g:t_grp_3 $T_MSCR/data/dir_a/dir_b/dir_c
+
+mkdir -p $T_MSCR/data/dir_a/dir_b/dir_c/dir_d
+chown t_usr_1:t_grp_1 $T_MSCR/data/dir_a/dir_b/dir_c/dir_d
+setfacl -x g:t_grp_3 $T_MSCR/data/dir_a/dir_b/dir_c/dir_d
+
+echo "== compare output"
+acl_compare
+
+echo "== drop caches and compare again"
+sync
+echo 3 > /proc/sys/vm/drop_caches
+acl_compare
+
+echo "== cleanup scratch fs"
+t_scratch_umount
+
+t_pass