Allowing tmpfs to be mounted in jail?

[Slawa Olhovchenkov]

On Fri, Aug 23, 2013 at 12:37:32AM +0300, Konstantin Belousov wrote:

> On Thu, Aug 22, 2013 at 12:15:29PM -0700, Xin Li wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA512
> > 
> > Hi,
> > 
> > Do anybody have concerns if I would commit this?
> > 
> > Index: sys/fs/tmpfs/tmpfs_vfsops.c
> > ===================================================================
> > - --- sys/fs/tmpfs/tmpfs_vfsops.c	(revision 254663)
> > +++ sys/fs/tmpfs/tmpfs_vfsops.c	(working copy)
> > @@ -420,4 +420,4 @@ struct vfsops tmpfs_vfsops = {
> >  	.vfs_statfs =			tmpfs_statfs,
> >  	.vfs_fhtovp =			tmpfs_fhtovp,
> >  };
> > - -VFS_SET(tmpfs_vfsops, tmpfs, 0);
> > +VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
> > 
> 
> Unrestricted tmpfs mounts can easily consume all available memory,
> making the host unusable.  But the change is probably fine, since
> we have global 'disable mount from the jail' flag.

tmpfs in jail must use memory limit from rctl memoryuse, I think.