From: Trond Myklebust Subject: Re: NFS file locking for clustered filesystems Date: Tue, 10 Aug 2004 17:43:14 -0700 Sender: nfs-admin@lists.sourceforge.net Message-ID: <1092184994.5857.19.camel@lade.trondhjem.org> References: <20040802105103.GJ25023@suse.de> <1091461098.3980.22.camel@lade.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Olaf Kirch , nfsv4@linux-nfs.org, nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1BuhDJ-0000xF-Rr for nfs@lists.sourceforge.net; Tue, 10 Aug 2004 17:43:33 -0700 Received: from adsl-207-214-87-84.dsl.snfc21.pacbell.net ([207.214.87.84] helo=lade.trondhjem.org) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:RC4-SHA:128) (Exim 4.34) id 1BuhDJ-0004vF-8c for nfs@lists.sourceforge.net; Tue, 10 Aug 2004 17:43:33 -0700 To: Sridhar Samudrala In-Reply-To: Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: P=E5 ty , 10/08/2004 klokka 17:15, skreiv Sridhar Samudrala: > I gathered the following from your suggestions to make the cluster filesy= stem > process the lock/unlock calls asynchronously, >=20 > NLM LOCK/UNLOCK Call on a file in a cluster filesystem exported from an N= FS > server will always respond with NLM LOCK/UNLOCK Reply with NLM_BLOCKED as= the > status. No. That would break the spec. See: http://www.opengroup.org/onlinepubs/9629799/NLM_LOCK.htm#tagcjh_11_11 NLM_BLOCKED is only a valid response if the client actually asked for blocking behaviour. In the case where the server is not able to reply in a timely fashion (I would suggest a short timeout period of a few seconds) it should reply with LCK_DENIED. (Note that when I talk about a "short timeout period", I do not mean that lockd itself is allowed to block.) > Once the cluster filesystem is done granting or denying the lock, the ser= ver > will send a NLM GRANTED_MSG/GRANTED_RES callbacks with the appropriate st= atus. >=20 > Is this correct? See above. That is only true if the client requested a blocking lock. > As Olaf suggested, can't we use the existing fl_notify callback instead o= f > setting up a new callback? Possibly. As long as the design remains clean... Cheers, Trond ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs