From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753430AbcJEFu0 (ORCPT ); Wed, 5 Oct 2016 01:50:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:57210 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751393AbcJEFuY (ORCPT ); Wed, 5 Oct 2016 01:50:24 -0400 Date: Wed, 5 Oct 2016 07:50:20 +0200 From: Jan Kara To: Ross Zwisler Cc: Jan Kara , linux-kernel@vger.kernel.org, "Theodore Ts'o" , Alexander Viro , Andreas Dilger , Andrew Morton , Christoph Hellwig , Dan Williams , Dave Chinner , Jan Kara , Matthew Wilcox , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@ml01.01.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Message-ID: <20161005055020.GB20752@quack2.suse.cz> References: <1475189370-31634-1-git-send-email-ross.zwisler@linux.intel.com> <1475189370-31634-11-git-send-email-ross.zwisler@linux.intel.com> <20161003105949.GP6457@quack2.suse.cz> <20161003210557.GA28177@linux.intel.com> <20161004055557.GB17515@quack2.suse.cz> <20161004153948.GA21248@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161004153948.GA21248@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 04-10-16 09:39:48, Ross Zwisler wrote: > > The gfp_mask that propagates from __do_fault() or do_page_mkwrite() is fine > > because at that point it is correct. But once we grab filesystem locks > > which are not reclaim safe, we should update vmf->gfp_mask we pass further > > down into DAX code to not contain __GFP_FS (that's a bug we apparently have > > there). And inside DAX code, we definitely are not generally safe to add > > __GFP_FS to mapping_gfp_mask(). Maybe we'd be better off propagating struct > > vm_fault into this function, using passed gfp_mask there and make sure > > callers update gfp_mask as appropriate. > > Yep, that makes sense to me. In reviewing your set it also occurred to me that > we might want to stick a struct vm_area_struct *vma pointer in the vmf, since > you always need a vma when you are using a vmf, but we pass them as a pair > everywhere. Actually, vma pointer will be in struct vm_fault after my DAX write-protection series. So once that lands, we can clean up whatever duplicit function parameters... Honza -- Jan Kara SUSE Labs, CR