From owner-freebsd-hackers@FreeBSD.ORG Wed Apr 20 17:29:12 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 73AF716A4CE; Wed, 20 Apr 2005 17:29:12 +0000 (GMT) Received: from khavrinen.csail.mit.edu (khavrinen.csail.mit.edu [128.30.28.20]) by mx1.FreeBSD.org (Postfix) with ESMTP id 08E5743D49; Wed, 20 Apr 2005 17:29:12 +0000 (GMT) (envelope-from wollman@khavrinen.csail.mit.edu) Received: from khavrinen.csail.mit.edu (localhost.csail.mit.edu [127.0.0.1]) j3KHTANG037030 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK CN=khavrinen.lcs.mit.edu issuer=SSL+20Client+20CA); Wed, 20 Apr 2005 13:29:11 -0400 (EDT) (envelope-from wollman@khavrinen.csail.mit.edu) Received: (from wollman@localhost) by khavrinen.csail.mit.edu (8.13.1/8.13.1/Submit) id j3KHTAmT037027; Wed, 20 Apr 2005 13:29:10 -0400 (EDT) (envelope-from wollman) From: Garrett Wollman MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16998.37222.529748.205885@khavrinen.csail.mit.edu> Date: Wed, 20 Apr 2005 13:29:10 -0400 To: Brian Fundakowski Feldman In-Reply-To: <20050420155233.GJ1157@green.homeunix.org> References: <20050419151800.GE1157@green.homeunix.org> <20050419160258.GA12287@stack.nl> <20050419160900.GB12287@stack.nl> <20050419161616.GF1157@green.homeunix.org> <20050419204723.GG1157@green.homeunix.org> <20050420140409.GA77731@stack.nl> <20050420142448.GH1157@green.homeunix.org> <20050420143842.GB77731@stack.nl> <20050420152038.GI1157@green.homeunix.org> <20050420153528.GC77731@stack.nl> <20050420155233.GJ1157@green.homeunix.org> X-Mailer: VM 7.17 under 21.4 (patch 17) "Jumbo Shrimp" XEmacs Lucid X-Greylist: Sender DNS name whitelisted, not delayed by milter-greylist-1.6 (khavrinen.csail.mit.edu [127.0.0.1]); Wed, 20 Apr 2005 13:29:11 -0400 (EDT) X-Virus-Scanned: ClamAV 0.83/842/Tue Apr 19 17:39:01 2005 on khavrinen.csail.mit.edu X-Virus-Status: Clean X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on khavrinen.csail.mit.edu X-Mailman-Approved-At: Thu, 21 Apr 2005 11:51:09 +0000 cc: freebsd-hackers@FreeBSD.ORG cc: freebsd-current@FreeBSD.ORG Subject: Re: NFS client/buffer cache deadlock X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Apr 2005 17:29:12 -0000 < said: > I think the first is more useful behavior than the last. Supporting it > should be exactly the same as supporting what happens if the actual > filesystem fills up. In this case, the filesystem is being requested to > write more "than there is room for." Returning a short write for operations on regular files would definitely be considered astonishing. The changes that you have made should be considered flow control, not admission control, and should appear to the user no differently than if we were waiting for a slow disk to write something; i.e., the user thread should be blocked until either the entire write completes, or the process is interrupted by a signal. -GAWollman