From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48640 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932174AbcIEN5T (ORCPT ); Mon, 5 Sep 2016 09:57:19 -0400 Subject: Patch "mm: silently skip readahead for DAX inodes" has been added to the 4.7-stable tree To: ross.zwisler@linux.intel.com, akpm@linux-foundation.org, dan.j.williams@intel.com, dave.hansen@linux.intel.com, david@fromorbit.com, gregkh@linuxfoundation.org, jack@suse.com, jmoyer@redhat.com, torvalds@linux-foundation.org Cc: , From: Date: Mon, 05 Sep 2016 15:55:27 +0200 Message-ID: <1473083727173231@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mm: silently skip readahead for DAX inodes to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-silently-skip-readahead-for-dax-inodes.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 11bd969fdefea3ac0cb9791224f1e09784e21e58 Mon Sep 17 00:00:00 2001 From: Ross Zwisler Date: Thu, 25 Aug 2016 15:17:17 -0700 Subject: mm: silently skip readahead for DAX inodes From: Ross Zwisler commit 11bd969fdefea3ac0cb9791224f1e09784e21e58 upstream. For DAX inodes we need to be careful to never have page cache pages in the mapping->page_tree. This radix tree should be composed only of DAX exceptional entries and zero pages. ltp's readahead02 test was triggering a warning because we were trying to insert a DAX exceptional entry but found that a page cache page had already been inserted into the tree. This page was being inserted into the radix tree in response to a readahead(2) call. Readahead doesn't make sense for DAX inodes, but we don't want it to report a failure either. Instead, we just return success and don't do any work. Link: http://lkml.kernel.org/r/20160824221429.21158-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler Reported-by: Jeff Moyer Cc: Dan Williams Cc: Dave Chinner Cc: Dave Hansen Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/readahead.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/mm/readahead.c +++ b/mm/readahead.c @@ -8,6 +8,7 @@ */ #include +#include #include #include #include @@ -545,6 +546,14 @@ do_readahead(struct address_space *mappi if (!mapping || !mapping->a_ops) return -EINVAL; + /* + * Readahead doesn't make sense for DAX inodes, but we don't want it + * to report a failure either. Instead, we just return success and + * don't do any work. + */ + if (dax_mapping(mapping)) + return 0; + return force_page_cache_readahead(mapping, filp, index, nr); } Patches currently in stable-queue which might be from ross.zwisler@linux.intel.com are queue-4.7/libnvdimm-nd_blk-mask-off-reserved-status-bits.patch queue-4.7/mm-silently-skip-readahead-for-dax-inodes.patch