Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946280AbbEPBzq (ORCPT ); Fri, 15 May 2015 21:55:46 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:58743 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946121AbbEPBzn (ORCPT ); Fri, 15 May 2015 21:55:43 -0400 Date: Sat, 16 May 2015 02:55:40 +0100 From: Al Viro To: Linus Torvalds Cc: NeilBrown , Andreas Dilger , Dave Chinner , Linux Kernel Mailing List , linux-fsdevel , Christoph Hellwig Subject: Re: [RFC][PATCHSET v3] non-recursive pathname resolution & RCU symlinks Message-ID: <20150516015540.GP7232@ZenIV.linux.org.uk> References: <20150513222533.GA24192@ZenIV.linux.org.uk> <20150514033040.GF7232@ZenIV.linux.org.uk> <20150514112304.GT15721@dastard> <20150516093022.51e1464e@notabene.brown> <20150516112503.2f970573@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1026 Lines: 19 On Fri, May 15, 2015 at 06:47:04PM -0700, Linus Torvalds wrote: > Now, maybe we could solve it with a new sleeping lock in the dentry > itself. Maybe we could allocate the new dentry early, add it to the > directory the usual way, but mark it as being "not ready" (so that > d_lookup() wouldn't use it). And have the sleeping lock be a new > sleeping lock in the dentry. See upthread. It might be doable (provided that we turn ->i_mutex into rwsem, to keep the exclusion with directory _modifiers_), but it'll need a really non-trivial code review of a bunch of filesystems, especially ones that want to play with the list of children like ceph does. And things like sillyrename and dcache-populating readdir instances, albeit not as scary as ceph. And then there's lustre... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/