cgroups: switch tmpfs mounting to new mount api

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

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index e07047da253853ff844f026b370e5c14ba622153..7a7e6283856e91b7bb31eec22d53dec36d2923a3 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1831,7 +1831,7 @@ static inline int cg_mount_cgroup_full(int type, struct hierarchy *h,
 __cgfsng_ops static bool cgfsng_mount(struct cgroup_ops *ops,
                                      struct lxc_conf *conf, int type)
 {
-       __do_close int dfd_mnt_cgroupfs = -EBADF;
+       __do_close int dfd_mnt_cgroupfs = -EBADF, fd_fs = -EBADF;
        __do_free char *cgroup_root = NULL;
        bool has_cgns = false, wants_force_mount = false;
        struct lxc_rootfs *rootfs = &conf->rootfs;
@@ -1908,16 +1908,25 @@ __cgfsng_ops static bool cgfsng_mount(struct cgroup_ops *ops,
         * relying on RESOLVE_BENEATH so we need to skip the leading "/" in the
         * DEFAULT_CGROUP_MOUNTPOINT define.
         */
-       ret = mount_at(rootfs->dfd_mnt, NULL, DEFAULT_CGROUP_MOUNTPOINT_RELATIVE,
-                      PROTECT_OPATH_DIRECTORY, PROTECT_LOOKUP_BENEATH_XDEV,
-                      "tmpfs", MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_RELATIME,
-                      "size=10240k,mode=755");
-       if (ret < 0 && errno == ENOSYS) {
+       fd_fs = fs_prepare("tmpfs", -EBADF, "", 0, 0);
+       if (fd_fs < 0) {
                cgroup_root = must_make_path(rootfs_mnt, DEFAULT_CGROUP_MOUNTPOINT, NULL);
-
                ret = safe_mount(NULL, cgroup_root, "tmpfs",
                                 MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_RELATIME,
                                 "size=10240k,mode=755", rootfs_mnt);
+       } else {
+               ret = fs_set_property(fd_fs, "mode", "0755");
+               if (ret < 0)
+                       return log_error_errno(-errno, errno, "Failed to mount tmpfs onto %d(dev)", fd_fs);
+
+               ret = fs_set_property(fd_fs, "size", "10240k");
+               if (ret < 0)
+                       return log_error_errno(-errno, errno, "Failed to mount tmpfs onto %d(dev)", fd_fs);
+
+               ret = fs_attach(fd_fs, rootfs->dfd_mnt, DEFAULT_CGROUP_MOUNTPOINT_RELATIVE,
+                               PROTECT_OPATH_DIRECTORY, PROTECT_LOOKUP_BENEATH_XDEV,
+                               MOUNT_ATTR_NOSUID | MOUNT_ATTR_NODEV |
+                               MOUNT_ATTR_NOEXEC | MOUNT_ATTR_RELATIME);
        }
        if (ret < 0)
                return log_error_errno(false, errno, "Failed to mount tmpfs on %s",