From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: which dentry a page belongs to Date: Fri, 23 Apr 2004 18:22:16 +0100 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <20040423182216.A4514@infradead.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jamie Lokier , linux-fsdevel@vger.kernel.org Return-path: Received: from phoenix.infradead.org ([213.86.99.234]:53008 "EHLO phoenix.infradead.org") by vger.kernel.org with ESMTP id S264879AbUDWRWR (ORCPT ); Fri, 23 Apr 2004 13:22:17 -0400 To: Shaya Potter Content-Disposition: inline In-Reply-To: <1082740707.1943.61.camel@zaphod>; from spotter@cs.columbia.edu on Fri, Apr 23, 2004 at 01:18:27PM -0400 List-Id: linux-fsdevel.vger.kernel.org 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. p.s. wondering what strange homework assignments they give these days..