From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark B Subject: same page access Date: Wed, 22 Oct 2003 10:15:17 +0200 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <200310221015.17946.mark@lemna.hr> References: <1065553341.8172.45.camel@patehci2> <1065635511.7602.38.camel@patehci2> <1066773266.2888.83.camel@patehci2> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from as102.hinet.hr ([195.29.150.42]:44038 "EHLO as102.htnet.hr") by vger.kernel.org with ESMTP id S263356AbTJVJxg (ORCPT ); Wed, 22 Oct 2003 05:53:36 -0400 Received: from ss402.hinet.hr (ss402.hinet.hr [195.29.150.2]) by as102.htnet.hr (0.0.0/8.12.10) with ESMTP id h9M9sn52238743 for ; Wed, 22 Oct 2003 11:54:49 +0200 (CEST) Received: from trinity.lemna.hr (206-20.adsl.net.hinet.hr [194.152.206.20]) by ss402.hinet.hr (0.0.0/8.12.10) with ESMTP id h9M9pMim028840 for ; Wed, 22 Oct 2003 11:53:30 +0200 (MEST) Received: from merneith.lemna.hr (infinity.lemna.hr [10.10.15.21]) by trinity.lemna.hr (8.12.2/8.12.2/SuSE Linux 0.6) with ESMTP id h9M8DFOb003773 for ; Wed, 22 Oct 2003 10:13:52 +0200 To: linux-fsdevel@vger.kernel.org In-Reply-To: <1066773266.2888.83.camel@patehci2> Content-Disposition: inline List-Id: linux-fsdevel.vger.kernel.org Hello all! I usually dig around kernel code to find answers, but I think this would take alot more time to dig than to explain from someone. Process 1 opens a file x, and does a read on the first few bytes, which in turn causes kernel to load the first page from the file (if the filesystem is using address_space_operations for all of it's access to files) Now a process 2 opens the same file and overwrites a few first bytes. Now, how does the kernel update the Process 1's page if it is already loaded? Mark Burazin -- Mark Burazin mark@lemna.hr ---<>---<>---<>---<>---<>---<>---<>---<>---<> Lemna d.o.o. http://www.lemna.biz - info@lemna.hr <>---<>---<>---<>---<>---<>---<>---<>---<>---