From owner-freebsd-fs Tue Sep 5 7:11:20 2000 Delivered-To: freebsd-fs@freebsd.org Received: from relay.butya.kz (butya-gw.butya.kz [212.154.129.94]) by hub.freebsd.org (Postfix) with ESMTP id AD20B37B43E; Tue, 5 Sep 2000 07:11:14 -0700 (PDT) Received: by relay.butya.kz (Postfix, from userid 1000) id E885228AAD; Tue, 5 Sep 2000 21:11:11 +0700 (ALMST) Received: from localhost (localhost [127.0.0.1]) by relay.butya.kz (Postfix) with ESMTP id D521D288C7; Tue, 5 Sep 2000 21:11:11 +0700 (ALMST) Date: Tue, 5 Sep 2000 21:11:11 +0700 (ALMST) From: Boris Popov To: "Daniel C. Sobral" Cc: freebsd-fs@FreeBSD.ORG, dillon@FreeBSD.ORG, semenu@FreeBSD.ORG, tegge@FreeBSD.ORG Subject: Re: CFR: nullfs, vm_objects and locks... (patch) In-Reply-To: <39B4EBBB.9C7A5CAB@newsguy.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 5 Sep 2000, Daniel C. Sobral wrote: > > The simple solution for it is to integrate lock structure into > > vnode and making vnode.v_vnlock initially point to it. Any filesystem > > above can pickup the pointer and assign it to v_vnlock field in its own > > vnode structure. If underlying filesystem doesn't provide any lock > > structure then bad times are coming and each layer can maintain its own > > lock state. > > How can it handle fs multiplexing? Ie, a single underlying layer with > multiple non-stacked layers above? Just like in the stacking case: access to vnode on the underlying filesystem should be serialized which is done by proper(shared) locking. -- Boris Popov http://www.butya.kz/~bp/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message