Re: [PATCH -mm 5/7] add user namespace

Eric W. Biederman
2006-07-14T17:16:01Z

Dave Hansen <haveblue@us.ibm.com> writes:

> On Fri, 2006-07-14 at 10:49 -0600, Eric W. Biederman wrote:
>> - if (current->fsuid == inode->i_uid)
>> + if ((current->fsuid == inode->i_uid) &&
>> + (current->nsproxy->user_ns == inode->i_sb->user_ns))
>> mode >>= 6;
>
> I really don't think assigning a user namespace to a superblock is the
> right way to go. Seems to me like the _view_ into the filesystem is
> what you want to modify. That would seem to me to mean that each
> 'struct namespace' (filesystem namespace) or vfsmount would be assigned
> a corresponding user namespace, *not* the superblock.

I guess since you can't bind mount across filesystem namespaces looking
at the vfsmount is ok, and more flexible.

But inode->i_sb->user_ns or nd->mnt->user_ns isn't nearly as important
as simply comparing some the appropriate user_ns values.

Eric