selinux: prepare for anon inode controls enablement

We plan to start labeling anon inodes (userfaultfd and io_uring file
descriptors) properly in selinux-policy, which means that domains using
these will need new rules.

See: fedora-selinux/selinux-policy#1351

Since ceph may optionally use io_uring, this patch adds the necessary
interface call to its policy to avoid a regression. As the new interface
call is put under a conditional, the policy package will be buildable
against selinux-policy with or without the above PR merged, but it will
need to be rebuilt against the updated selinux-policy to actually pick
up the new rules.

I tested this on a minimal ceph cluster with 'bdev_ioring = true' added
to ceph.conf. I got io_uring denials without this patch + with
selinux-policy with PR#1351 and no denials with ceph rebuilt with this
patch.

Signed-off-by: Ondrej Mosnacek <[email protected]>

selinux/ceph.te

@@ -75,6 +75,9 @@ manage_lnk_files_pattern(ceph_t, ceph_var_run_t, ceph_var_run_t)
 
 kernel_read_system_state(ceph_t)
 kernel_read_network_state(ceph_t)
+ifdef(`kernel_io_uring_use',`
+	kernel_io_uring_use(ceph_t)
+')
 allow ceph_t kernel_t:system module_request;
 
 corenet_all_recvfrom_unlabeled(ceph_t)