From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [LSF/MM TOPIC] [ATTEND] Direct IO Date: Thu, 16 Jan 2014 14:28:42 -0800 Message-ID: <20140116222842.GQ9037@kmo> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: lsf-pc@lists.linux-foundation.org, LKML , linux-fsdevel@vger.kernel.org Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hi, I'd like to discuss the current state and future direction of the DIO code. I and others have been kicking around the idea for some time now of reworking direct IO at the filesystem level in terms of bios; this will radically simplify fs/direct-IO.c, and solve some other longstanding issues, like double usage of the page cache by the loopback device - the goal will be for things like loop to just be able to submit bios to the filesystem code. Immutable biovecs are now almost upstream, which was a major prereq; this helps enables a DIO rewrite that basically pushes bios up a layer. Soon, we'll need to start reworking vfs interfaces, and input from the filesystem developers (especially btrfs) will be necessary there.