cgroups: switch to flag-based checking

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 523283452ebff3e71d6c68f068f205816d100703..8cb94edafa514f5cd2a7ae8f46c40bf6d7b84461 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1791,7 +1791,8 @@ static int __cg_mount_direct(int cg_flags, struct hierarchy *h,
        flags |= MOUNT_ATTR_NODEV;
        flags |= MOUNT_ATTR_RELATIME;
 
-       if (cg_flags == LXC_AUTO_CGROUP_RO || cg_flags == LXC_AUTO_CGROUP_FULL_RO)
+       if ((cg_flags & LXC_AUTO_CGROUP_RO) ||
+           (cg_flags & LXC_AUTO_CGROUP_FULL_RO))
                flags |= MOUNT_ATTR_RDONLY;
 
        if (is_unified_hierarchy(h)) {
@@ -1860,7 +1861,8 @@ static inline int cg_mount_cgroup_full(int cg_flags, struct hierarchy *h,
                                       int dfd_mnt_cgroupfs,
                                       const char *hierarchy_mnt)
 {
-       if (cg_flags < LXC_AUTO_CGROUP_FULL_RO || cg_flags > LXC_AUTO_CGROUP_FULL_MIXED)
+       if (!(cg_flags & LXC_AUTO_CGROUP_FULL_RO) &&
+           !(cg_flags & LXC_AUTO_CGROUP_FULL_MIXED))
                return 0;
 
        return __cg_mount_direct(cg_flags, h, rootfs, dfd_mnt_cgroupfs, hierarchy_mnt);
@@ -1887,7 +1889,7 @@ __cgfsng_ops static bool cgfsng_mount(struct cgroup_ops *ops,
                return ret_set_errno(false, EINVAL);
 
        if ((cg_flags & LXC_AUTO_CGROUP_MASK) == 0)
-               return true;
+               return log_trace(true, "No cgroup mounts requested");
 
        if (cg_flags & LXC_AUTO_CGROUP_FORCE)
                wants_force_mount = true;
@@ -1914,9 +1916,13 @@ __cgfsng_ops static bool cgfsng_mount(struct cgroup_ops *ops,
        if (in_cgroup_ns && !wants_force_mount)
                return true;
 
-       if (cg_flags == LXC_AUTO_CGROUP_NOSPEC)
+       /*
+        * Fallback to a mixed layout when the user did not specify what cgroup
+        * layout they want.
+        */
+       if ((cg_flags & LXC_AUTO_CGROUP_NOSPEC))
                cg_flags = LXC_AUTO_CGROUP_MIXED;
-       else if (cg_flags == LXC_AUTO_CGROUP_FULL_NOSPEC)
+       else if (cg_flags & LXC_AUTO_CGROUP_FULL_NOSPEC)
                cg_flags = LXC_AUTO_CGROUP_FULL_MIXED;
 
        /* This is really the codepath that we want. */