From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45552 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752814AbcGYU0b (ORCPT ); Mon, 25 Jul 2016 16:26:31 -0400 Subject: Patch "tmpfs: fix regression hang in fallocate undo" has been added to the 3.14-stable tree To: hughd@google.com, gregkh@linuxfoundation.org, torvalds@linux-foundation.org Cc: , From: Date: Mon, 25 Jul 2016 13:26:45 -0700 Message-ID: <1469478405215188@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 tmpfs: fix regression hang in fallocate undo to the 3.14-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: tmpfs-fix-regression-hang-in-fallocate-undo.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 7f556567036cb7f89aabe2f0954b08566b4efb53 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Sun, 10 Jul 2016 16:46:32 -0700 Subject: tmpfs: fix regression hang in fallocate undo From: Hugh Dickins commit 7f556567036cb7f89aabe2f0954b08566b4efb53 upstream. The well-spotted fallocate undo fix is good in most cases, but not when fallocate failed on the very first page. index 0 then passes lend -1 to shmem_undo_range(), and that has two bad effects: (a) that it will undo every fallocation throughout the file, unrestricted by the current range; but more importantly (b) it can cause the undo to hang, because lend -1 is treated as truncation, which makes it keep on retrying until every page has gone, but those already fully instantiated will never go away. Big thank you to xfstests generic/269 which demonstrates this. Fixes: b9b4bb26af01 ("tmpfs: don't undo fallocate past its last page") Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/shmem.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1893,9 +1893,11 @@ static long shmem_fallocate(struct file NULL); if (error) { /* Remove the !PageUptodate pages we added */ - shmem_undo_range(inode, - (loff_t)start << PAGE_CACHE_SHIFT, - ((loff_t)index << PAGE_CACHE_SHIFT) - 1, true); + if (index > start) { + shmem_undo_range(inode, + (loff_t)start << PAGE_CACHE_SHIFT, + ((loff_t)index << PAGE_CACHE_SHIFT) - 1, true); + } goto undone; } Patches currently in stable-queue which might be from hughd@google.com are queue-3.14/tmpfs-fix-regression-hang-in-fallocate-undo.patch queue-3.14/tmpfs-don-t-undo-fallocate-past-its-last-page.patch