From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42150 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752576AbdJSNOW (ORCPT ); Thu, 19 Oct 2017 09:14:22 -0400 Subject: Patch "f2fs: do not wait for writeback in write_begin" has been added to the 4.9-stable tree To: jaegeuk@kernel.org, alexander.levin@verizon.com, gregkh@linuxfoundation.org, yuchao0@huawei.com Cc: , From: Date: Thu, 19 Oct 2017 15:14:13 +0200 Message-ID: <1508418853119165@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 f2fs: do not wait for writeback in write_begin to the 4.9-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: f2fs-do-not-wait-for-writeback-in-write_begin.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Oct 19 15:04:02 CEST 2017 From: Jaegeuk Kim Date: Fri, 17 Feb 2017 09:55:55 -0800 Subject: f2fs: do not wait for writeback in write_begin From: Jaegeuk Kim [ Upstream commit 86d54795c94532075d862aa0a79f0c981dab4bdd ] Otherwise we can get livelock like below. [79880.428136] dbench D 0 18405 18404 0x00000000 [79880.428139] Call Trace: [79880.428142] __schedule+0x219/0x6b0 [79880.428144] schedule+0x36/0x80 [79880.428147] schedule_timeout+0x243/0x2e0 [79880.428152] ? update_sd_lb_stats+0x16b/0x5f0 [79880.428155] ? ktime_get+0x3c/0xb0 [79880.428157] io_schedule_timeout+0xa6/0x110 [79880.428161] __lock_page+0xf7/0x130 [79880.428164] ? unlock_page+0x30/0x30 [79880.428167] pagecache_get_page+0x16b/0x250 [79880.428171] grab_cache_page_write_begin+0x20/0x40 [79880.428182] f2fs_write_begin+0xa2/0xdb0 [f2fs] [79880.428192] ? f2fs_mark_inode_dirty_sync+0x16/0x30 [f2fs] [79880.428197] ? kmem_cache_free+0x79/0x200 [79880.428203] ? __mark_inode_dirty+0x17f/0x360 [79880.428206] generic_perform_write+0xbb/0x190 [79880.428213] ? file_update_time+0xa4/0xf0 [79880.428217] __generic_file_write_iter+0x19b/0x1e0 [79880.428226] f2fs_file_write_iter+0x9c/0x180 [f2fs] [79880.428231] __vfs_write+0xc5/0x140 [79880.428235] vfs_write+0xb2/0x1b0 [79880.428238] SyS_write+0x46/0xa0 [79880.428242] entry_SYSCALL_64_fastpath+0x1e/0xad Fixes: cae96a5c8ab6 ("f2fs: check io submission more precisely") Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/data.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1619,7 +1619,12 @@ static int f2fs_write_begin(struct file goto fail; } repeat: - page = grab_cache_page_write_begin(mapping, index, flags); + /* + * Do not use grab_cache_page_write_begin() to avoid deadlock due to + * wait_for_stable_page. Will wait that below with our IO control. + */ + page = pagecache_get_page(mapping, index, + FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS); if (!page) { err = -ENOMEM; goto fail; Patches currently in stable-queue which might be from jaegeuk@kernel.org are queue-4.9/f2fs-do-ssr-for-data-when-there-is-enough-free-space.patch queue-4.9/f2fs-do-not-wait-for-writeback-in-write_begin.patch