aufs as root vor openvz CT

[Sergey Korshunoff]

   Hi!
   I use aufs (openvz kernel 2.6.32) for mounting root fs for containers (CT).
   And faced a problem with checkpoint/restore. When NFS is used between an
   aufs mount point and  CT root, then checkpoint/restore is working fine
   (aufs is compiled with AUFS_EXPORTS=y). But whithout NFS there are found a
   following problems:
   -- file is referenced outside
   [code]
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â          if        (obj->o_count        !=
   atomic_long_read(&file->f_count)) {
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  eprintk_ctx("file struct is
   referenced outside %d %ld\n", obj->o_count, atomic_long_read(&file->f_c
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
   cpt_printk_dentry(file->f_dentry, file->f_vfsmnt);
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  return -EBUSY;
   [/code]
   -- file is from FSMAGIC_SQUASH
   -- file can not be accesed from ve
   [code]
   Â Â Â Â Â  if (!(oldmnt->mnt_sb->s_flags & MS_NOUSER) &&
   Â Â Â Â Â Â Â Â Â!ve_accessible_veid(vfsmnt->owner,get_exec_env()->veid))
   {
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  retval = ERR_PTR(-EINVAL);
   Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  goto out_err;
   Â Â Â Â Â Â Â  }
   [/code]
   -- name of file is
   [code]
   Restore error, undump failed: No such file or directory
   Error: rst_open_file: failed to lookup path
   '/livecd/images/_vz_private_202/ct-202-01-base.lzm/lib/[1]libnss_files-2.12.
   so':
   [/code]
   (aufs   mount   pount  is  /vz/private/202,  squashfs  is  mounted  at
   /livecd/images/_vz_private_202/ct-202-01-base.lzm)
   A question: is it possible to hide internal aufs files from the rest of the
   kernel? And represent this files as aufs files?

References

   1. http://libnss_files-2.12.so/

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