From: Dave Chinner Subject: Re: [PATCH v5 00/22] Rewrite XIP code and add XIP support to ext4 Date: Thu, 23 Jan 2014 18:48:25 +1100 Message-ID: <20140123074825.GL13997@dastard> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org To: Matthew Wilcox Return-path: Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Wed, Jan 15, 2014 at 08:24:18PM -0500, Matthew Wilcox wrote: > This series of patches add support for XIP to ext4. Unfortunately, > it turns out to be necessary to rewrite the existing XIP support code > first due to races that are unfixable in the current design. > > Since v4 of this patchset, I've improved the documentation, fixed a > couple of warnings that a newer version of gcc emitted, and fixed a > bug where we would read/write the wrong address for I/Os that were not > aligned to PAGE_SIZE. > > I've dropped the PMD fault patch from this set since there are some > places where we would need to split a PMD page and there's no way to do > that right now. In its place, I've added a patch which attempts to add > support for unwritten extents. I'm still in two minds about this; on the > one hand, it's clearly a win for reads and writes. On the other hand, > it adds a lot of complexity, and it probably isn't a win for pagefaults. FYI, this may just be pure coincidence, but shortly after the first boot of a machine with this patchset on 3.13 the root *ext3* filesystem started having problems. It now gives persistent ENOSPC errors when there's 2.3GB of space free (on a 8GB partition), even though e2fsck says the filesystem is clean and error free. Fmeh. Update: I've just removed the patchset, rebuilt the kernel and the ENOSPC problem is still there. So it may be co-incidence, but given that it is persistent something is screwed got screwed up in the filesytem. Cheers, Dave. -- Dave Chinner david@fromorbit.com -- 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