From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaya Potter Subject: Re: which dentry a page belongs to Date: Fri, 23 Apr 2004 13:32:52 -0400 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <1082741571.1943.66.camel@zaphod> References: <1082732223.1943.11.camel@zaphod> <20040423151458.GC6300@mail.shareable.org> <1082734938.1943.26.camel@zaphod> <20040423173738.A3812@infradead.org> <1082739174.1943.49.camel@zaphod> <20040423180130.A4255@infradead.org> <1082740707.1943.61.camel@zaphod> <20040423182216.A4514@infradead.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Jamie Lokier , linux-fsdevel@vger.kernel.org Return-path: Received: from opus.cs.columbia.edu ([128.59.20.100]:54942 "EHLO opus.cs.columbia.edu") by vger.kernel.org with ESMTP id S264886AbUDWRdT (ORCPT ); Fri, 23 Apr 2004 13:33:19 -0400 To: Christoph Hellwig In-Reply-To: <20040423182216.A4514@infradead.org> List-Id: linux-fsdevel.vger.kernel.org On Fri, 2004-04-23 at 18:22 +0100, Christoph Hellwig wrote: > On Fri, Apr 23, 2004 at 01:18:27PM -0400, Shaya Potter wrote: > > > you can be in writepage with page->mapping->i_mmap{,shared} beeing empty. > > > No way in hell you'll ever get to a dentry. > > > > the question being in what cases will that happen, so I can make a > > determination if I care about those cases. (i.e. if the dentry is > > deleted, I don't particularly care, as since I am versioning, if it's > > already been deleted, don't care) > > > > i.e. how can I determine where i_mmap{,shared} exist and when does't it? > > (in file system page context). > > if there's no mapping anymore at the point of the writeback. e.g. when > an munmap happened before the writeback is scheduled. And you can't > determine it except by checking whether it's empty. so that could be very repeatable if a process does a write to memory and then quits. hmm. > p.s. wondering what strange homework assignments they give these days.. not homework, research project. and yes, it is strange. :) I'm finished w/ my course work.