From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frankvm.xs4all.nl ([83.163.148.79]:60217 "EHLO janus.localdomain" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754522Ab1HDR1M (ORCPT ); Thu, 4 Aug 2011 13:27:12 -0400 Date: Thu, 4 Aug 2011 19:27:10 +0200 From: Frank van Maarseveen To: Trond Myklebust Cc: "J. Bruce Fields" , Linux NFS mailing list Subject: Re: [NLM] fcntl(F_SETLKW) yields -ENOLCK when grace period expires. Message-ID: <20110804172710.GB18087@janus> References: <20110804103018.GA11727@janus> <20110804163452.GE12445@fieldses.org> <20110804164313.GA17572@janus> <20110804164913.GG12445@fieldses.org> <1312477820.8919.5.camel@lade.trondhjem.org> Content-Type: text/plain; charset=us-ascii In-Reply-To: <1312477820.8919.5.camel@lade.trondhjem.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Thu, Aug 04, 2011 at 01:10:20PM -0400, Trond Myklebust wrote: > On Thu, 2011-08-04 at 12:49 -0400, J. Bruce Fields wrote: > > On Thu, Aug 04, 2011 at 06:43:13PM +0200, Frank van Maarseveen wrote: > > > On Thu, Aug 04, 2011 at 12:34:52PM -0400, J. Bruce Fields wrote: > > > > On Thu, Aug 04, 2011 at 12:30:19PM +0200, Frank van Maarseveen wrote: > > > > > Both client- and server run 2.6.39.3, NFSv3 over UDP (without the > > > > > relock_filesystem patch proposed earlier). > > > > > > > > > > A second client has an exclusive lock on a file on the server. The > > > > > client under test calls fcntl(F_SETLKW) to wait for the same exclusive > > > > > lock. Wireshark sees NLM V4 LOCK calls resulting in NLM_BLOCKED. > > > > > > > > > > Next the server is rebooted. The second client recovers the lock > > > > > correctly. The client under test now receives NLM_DENIED_GRACE_PERIOD for > > > > > every NLM V4 LOCK request resulting from the waiting fcntl(F_SETLKW). When > > > > > this changes to NLM_BLOCKED after grace period expiration the fcntl > > > > > returns -ENOLCK ("No locks available.") instead of continuing to wait. > > > > > > > > So that sounds like a client bug, and correct behavior from the server > > > > (assuming the second client was still holding the lock throughout). > > > > > > yes. > > Is the client actually asking for a blocking lock after the grace period > expires? yes, according to my interpretation of that of wireshark, see reply to Bruce. -- Frank