From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:34143 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726597AbeLKOAT (ORCPT ); Tue, 11 Dec 2018 09:00:19 -0500 Subject: FAILED: patch "[PATCH] dax: Check page->mapping isn't NULL" failed to apply to 4.19-stable tree To: willy@infradead.org, dan.j.williams@intel.com, jack@suse.cz, jthumshirn@suse.de, stable@vger.kernel.org Cc: From: Date: Tue, 11 Dec 2018 15:00:15 +0100 Message-ID: <154453681519414@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: The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From c93db7bb6ef3251e0ea48ade311d3e9942748e1c Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 27 Nov 2018 13:16:33 -0800 Subject: [PATCH] dax: Check page->mapping isn't NULL If we race with inode destroy, it's possible for page->mapping to be NULL before we even enter this routine, as well as after having slept waiting for the dax entry to become unlocked. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: Reported-by: Jan Kara Signed-off-by: Matthew Wilcox Reviewed-by: Johannes Thumshirn Reviewed-by: Jan Kara Signed-off-by: Dan Williams diff --git a/fs/dax.c b/fs/dax.c index 9bcce89ea18e..e69fc231833b 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -365,7 +365,7 @@ bool dax_lock_mapping_entry(struct page *page) struct address_space *mapping = READ_ONCE(page->mapping); locked = false; - if (!dax_mapping(mapping)) + if (!mapping || !dax_mapping(mapping)) break; /*