From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Provide vfs support for NFSv4 delegations Date: Fri, 3 Feb 2012 16:09:51 -0500 Message-ID: <1328303397-3872-1-git-send-email-bfields@redhat.com> References: <20120203205818.GE2999@fieldses.org> Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christoph Hellwig To: Al Viro Return-path: In-Reply-To: <20120203205818.GE2999-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org The following patches provide vfs support for NFSv4 delegations. If they look sane then I'd like to get some version of them merged into 3.4. I'm assuming Al would be the one to do that. Currently nfsd implements delegations as leases. However, leases don't have quite the same semantics, which means that delegations are currently enforced correctly only for conflicts between NFSv4 clients. So, I define a new FL_DELEG flag to mark NFSv4 delegations. In most respects delegations behave just like leases, but they need to be broken on more operations. Delegations aren't exposed to userspace; nfsd is the only user. In theory this code allows both read and write delegations, but I'm only using read delegations for now--write delegations are a project for another day. (At which point write leases will probably need some fixing too, while we're at it.) --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html