From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [PATCH 0/18] export operations rewrite Date: Fri, 4 May 2007 16:49:50 +1000 Message-ID: <17978.55182.198497.902215@notabene.brown> References: <20070317010946.GA24947@infradead.org> <17932.34141.590792.120454@notabene.brown> <20070501103905.GA30906@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: linux-fsdevel@vger.kernel.org, nfs@lists.sourceforge.net To: Christoph Hellwig Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1HjrcV-0003Qv-5J for nfs@lists.sourceforge.net; Thu, 03 May 2007 23:50:23 -0700 Received: from mx1.suse.de ([195.135.220.2]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1HjrcX-0000sW-Jm for nfs@lists.sourceforge.net; Thu, 03 May 2007 23:50:25 -0700 In-Reply-To: message from Christoph Hellwig on Tuesday May 1 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net On Tuesday May 1, hch@infradead.org wrote: > On Fri, Mar 30, 2007 at 01:34:53PM +1000, Neil Brown wrote: > > On Saturday March 17, hch@infradead.org wrote: > > > > less that 2 weeks later.... > > more than one month later.... :) > Thanks for your explanations. > - the calling conversion on the decode side where we first call > ->decode_fh to split the filehandle into two blobs only to > recurse back into exportfs and then recurse back into the filesystem > seems rather odd. By having two methods to get the dentry and > parent directly from the on the wire file handle this big callstack > collapses to a very simple one. This is the bit I was particularly missing. I see now how this aspect was awkward before, and how your changes make the flow clearer. Getting rid of s_export_op->find_exported_dentry is something I'm very happy about. There was actually bug lurking there that I never got around to fixing. The code: - /* Ok, we can export it */; - if (!inode->i_sb->s_export_op->find_exported_dentry) - inode->i_sb->s_export_op->find_exported_dentry = - find_exported_dentry; assumes that the address of find_exported_dentry will never change. But if you unload nfsd.ko, then re-load it. it could be different, yet a filesystem could still have to old value in it's s_export_op. That would be bad. I'm glad it is gone. Thanks, NeilBrown ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs