From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751164AbWEQVoK (ORCPT ); Wed, 17 May 2006 17:44:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751163AbWEQVoK (ORCPT ); Wed, 17 May 2006 17:44:10 -0400 Received: from wr-out-0506.google.com ([64.233.184.224]:22549 "EHLO wr-out-0506.google.com") by vger.kernel.org with ESMTP id S1751161AbWEQVoI convert rfc822-to-8bit (ORCPT ); Wed, 17 May 2006 17:44:08 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=aN0qEERS0KCR0X4Bf51EiePb8wQr4vmGKG222Iyvj0gKjF5X6MU9awmIlNjJMSVyIAM/Fdy5lqekcppyfbPqb6tlpDyUg7lPqRe1+3scRiQSByhNG64DykF6hi9P+yoxuJdu/uDdyLsSo1UVXrI6tqKlBskqHq+nzWjtlZp+23A= Message-ID: <4ae3c140605171444o66de4caqdbe38e028aed94bf@mail.gmail.com> Date: Wed, 17 May 2006 17:44:07 -0400 From: "Xin Zhao" To: "Chris Wedgwood" Subject: Re: HELP! vfs_readv() issue Cc: linux-kernel , linux-fsdevel@vger.kernel.org In-Reply-To: <20060516043107.GA5321@taniwha.stupidest.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <4ae3c140605151657m152c0e7bl7f52e2a2def0aeca@mail.gmail.com> <20060516043107.GA5321@taniwha.stupidest.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thank you for your care. What I am trying to do is to rewrite NFS in the virtual machine environment so that network communication can be replaced with inter-VM communication. But after I remove the original rpc stuff, I ran into some strange problem, including this one. Interesting thing is that I noticed that even with standard NFS implementation, it is still possible that nfsd_read() return resp->count to be 0. At this time, eof is also equal to 1. This seems to be right since NFSD already reach the end of the file. But question is since 0 byte is read this time, NFS should detect EOF in previous read. Why need one more read? Xin On 5/16/06, Chris Wedgwood wrote: > On Mon, May 15, 2006 at 07:57:21PM -0400, Xin Zhao wrote: > > > I am writing a file system, but vfs_read() sometimes return 0. What > > could cause this problem? > > EOF? >