[Devel] [PATCH RHEL7 COMMIT] ve/fs/overlay: allow overlayfs to be used inside a Container

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.18.2.vz7.14.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.18.2.vz7.14.5
------>
commit deacc4de82d5bff2ce0136429fc2e3b8cd186812
Author: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
Date:   Mon May 23 13:29:54 2016 +0400

    ve/fs/overlay: allow overlayfs to be used inside a Container
    
    This is temporary decision to make Docker in CT work with overlayfs
    storage driver, it can be unsafe to give access to fs-overlay module
    from container.
    
    Note: "overlay" kernel module must be pre-loaded on the Host,
          it is _not_ autoloaded from inside a Container.
    
    https://jira.sw.ru/browse/PSBM-47280
    
    Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
    
    khorenko@: overlayfs stibility in current RHEL7 kernel has not been checked
    yet, so it can be used for testing purposes only for now.
---
 fs/overlayfs/super.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 7e0388b..c20cfe9 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1129,6 +1129,7 @@ static struct file_system_type ovl_fs_type = {
 	.name		= "overlay",
 	.mount		= ovl_mount,
 	.kill_sb	= kill_anon_super,
+	.fs_flags       = FS_VIRTUALIZED,
 };
 MODULE_ALIAS_FS("overlay");