From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 869F7C43441 for ; Thu, 29 Nov 2018 09:31:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 113CF2081B for ; Thu, 29 Nov 2018 09:31:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 113CF2081B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cn.fujitsu.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726706AbeK2Ug0 (ORCPT ); Thu, 29 Nov 2018 15:36:26 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:57797 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726008AbeK2UgZ (ORCPT ); Thu, 29 Nov 2018 15:36:25 -0500 X-IronPort-AV: E=Sophos;i="5.56,293,1539619200"; d="scan'208";a="48825111" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 29 Nov 2018 17:31:40 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 00ED44B734A5 for ; Thu, 29 Nov 2018 17:31:39 +0800 (CST) Received: from fnst.lan (10.167.226.155) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 29 Nov 2018 17:31:45 +0800 From: Lu Fengqi To: Subject: [PATCH] btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow Date: Thu, 29 Nov 2018 17:31:32 +0800 Message-ID: <20181129093132.25147-1-lufq.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.167.226.155] X-yoursite-MailScanner-ID: 00ED44B734A5.A19F0 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: lufq.fnst@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extents don't present on disk, and the btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b1eee ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") Signed-off-by: Lu Fengqi --- fs/btrfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d54bdef16d8d..9c5e9629eb6c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1369,7 +1369,8 @@ static noinline int run_delalloc_nocow(struct inode *inode, * Do the same check as in btrfs_cross_ref_exist but * without the unnecessary search. */ - if (btrfs_file_extent_generation(leaf, fi) <= + if (!nolock && + btrfs_file_extent_generation(leaf, fi) <= btrfs_root_last_snapshot(&root->root_item)) goto out_check; if (extent_type == BTRFS_FILE_EXTENT_REG && !force) -- 2.19.2