From patchwork Tue Jul 26 09:38:20 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9247955 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C6FDE6077C for ; Tue, 26 Jul 2016 09:38:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B515A26A4D for ; Tue, 26 Jul 2016 09:38:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A9AA126B39; Tue, 26 Jul 2016 09:38:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 19F9626A4D for ; Tue, 26 Jul 2016 09:38:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752943AbcGZJi2 (ORCPT ); Tue, 26 Jul 2016 05:38:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:54792 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751692AbcGZJi1 (ORCPT ); Tue, 26 Jul 2016 05:38:27 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 56364AC9F; Tue, 26 Jul 2016 09:38:25 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 0DD3F1E0F0F; Tue, 26 Jul 2016 11:38:24 +0200 (CEST) From: Jan Kara To: Jens Axboe Cc: Tejun Heo , Laurent Dufour , Ted Tso , Dmitry Vyukov , linux-fsdevel@vger.kernel.org, Jan Kara Subject: [PATCH] writeback: Write dirty times for WB_SYNC_ALL writeback Date: Tue, 26 Jul 2016 11:38:20 +0200 Message-Id: <1469525900-9212-1-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently we take care to handle I_DIRTY_TIME in vfs_fsync() and queue_io() so that inodes which have only dirty timestamps are properly written on fsync(2) and sync(2). However there are other call sites - most notably going through write_inode_now() - which expect inode to be clean after WB_SYNC_ALL writeback. This is not currently true as we do not clear I_DIRTY_TIME in __writeback_single_inode() even for WB_SYNC_ALL writeback in all the cases. This then resulted in the following oops because bdev_write_inode() did not clean the inode and writeback code later stumbled over a dirty inode with detached wb. general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN Modules linked in: CPU: 3 PID: 32 Comm: kworker/u10:1 Not tainted 4.6.0-rc3+ #349 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: writeback wb_workfn (flush-11:0) task: ffff88006ccf1840 ti: ffff88006cda8000 task.ti: ffff88006cda8000 RIP: 0010:[] [] locked_inode_to_wb_and_lock_list+0xa2/0x750 RSP: 0018:ffff88006cdaf7d0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88006ccf2050 RDX: 0000000000000000 RSI: 000000114c8a8484 RDI: 0000000000000286 RBP: ffff88006cdaf820 R08: ffff88006ccf1840 R09: 0000000000000000 R10: 000229915090805f R11: 0000000000000001 R12: ffff88006a72f5e0 R13: dffffc0000000000 R14: ffffed000d4e5eed R15: ffffffff8830cf40 FS: 0000000000000000(0000) GS:ffff88006d500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000003301bf8 CR3: 000000006368f000 CR4: 00000000000006e0 DR0: 0000000000001ec9 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Stack: ffff88006a72f680 ffff88006a72f768 ffff8800671230d8 03ff88006cdaf948 ffff88006a72f668 ffff88006a72f5e0 ffff8800671230d8 ffff88006cdaf948 ffff880065b90cc8 ffff880067123100 ffff88006cdaf970 ffffffff8188e12e Call Trace: [< inline >] inode_to_wb_and_lock_list fs/fs-writeback.c:309 [] writeback_sb_inodes+0x4de/0x1250 fs/fs-writeback.c:1554 [] __writeback_inodes_wb+0x104/0x1e0 fs/fs-writeback.c:1600 [] wb_writeback+0x7ce/0xc90 fs/fs-writeback.c:1709 [< inline >] wb_do_writeback fs/fs-writeback.c:1844 [] wb_workfn+0x2f9/0x1000 fs/fs-writeback.c:1884 [] process_one_work+0x78e/0x15c0 kernel/workqueue.c:2094 [] worker_thread+0xdb/0xfc0 kernel/workqueue.c:2228 [] kthread+0x23f/0x2d0 drivers/block/aoe/aoecmd.c:1303 [] ret_from_fork+0x22/0x50 arch/x86/entry/entry_64.S:392 Code: 05 94 4a a8 06 85 c0 0f 85 03 03 00 00 e8 07 15 d0 ff 41 80 3e 00 0f 85 64 06 00 00 49 8b 9c 24 88 01 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 0f 85 17 06 00 00 48 8b 03 48 83 c0 50 48 39 c3 RIP [< inline >] wb_get include/linux/backing-dev-defs.h:212 RIP [] locked_inode_to_wb_and_lock_list+0xa2/0x750 fs/fs-writeback.c:281 RSP ---[ end trace 986a4d314dcb2694 ]--- Fix the problem by making sure __writeback_single_inode() writes inode only with dirty times in WB_SYNC_ALL mode. Reported-by: Dmitry Vyukov Tested-by: Laurent Dufour Signed-off-by: Jan Kara --- fs/fs-writeback.c | 1 + 1 file changed, 1 insertion(+) Jens, can you please take this patch? Thanks! Honza diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 989a2cef6b76..51efb644410a 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1291,6 +1291,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) dirty = inode->i_state & I_DIRTY; if (inode->i_state & I_DIRTY_TIME) { if ((dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) || + wbc->sync_mode == WB_SYNC_ALL || unlikely(inode->i_state & I_DIRTY_TIME_EXPIRED) || unlikely(time_after(jiffies, (inode->dirtied_time_when +