From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 816A06B0069 for ; Thu, 1 Dec 2016 17:24:49 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id a8so367323312pfg.0 for ; Thu, 01 Dec 2016 14:24:49 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id p2si1860316pge.244.2016.12.01.14.24.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Dec 2016 14:24:48 -0800 (PST) Date: Thu, 1 Dec 2016 15:24:47 -0700 From: Ross Zwisler Subject: Re: [PATCH 5/6] dax: Call ->iomap_begin without entry lock during dax fault Message-ID: <20161201222447.GB13739@linux.intel.com> References: <1479980796-26161-1-git-send-email-jack@suse.cz> <1479980796-26161-6-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1479980796-26161-6-git-send-email-jack@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: linux-fsdevel@vger.kernel.org, Ross Zwisler , linux-ext4@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, Johannes Weiner On Thu, Nov 24, 2016 at 10:46:35AM +0100, Jan Kara wrote: > Currently ->iomap_begin() handler is called with entry lock held. If the > filesystem held any locks between ->iomap_begin() and ->iomap_end() > (such as ext4 which will want to hold transaction open), this would cause > lock inversion with the iomap_apply() from standard IO path which first > calls ->iomap_begin() and only then calls ->actor() callback which grabs > entry locks for DAX. I don't see the dax_iomap_actor() grabbing any entry locks for DAX? Is this an issue currently, or are you just trying to make the code consistent so we don't run into issues in the future? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org