Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031209AbcDMOTH (ORCPT ); Wed, 13 Apr 2016 10:19:07 -0400 Received: from g9t5009.houston.hp.com ([15.240.92.67]:54021 "EHLO g9t5009.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031045AbcDMOTF (ORCPT ); Wed, 13 Apr 2016 10:19:05 -0400 Message-ID: <1460556627.24985.28.camel@hpe.com> Subject: Re: ext4 error From: Toshi Kani To: Eric Shang , Matthew Wilcox Cc: "akpm@linux-foundation.org" , "dan.j.williams@intel.com" , "viro@zeniv.linux.org.uk" , "ross.zwisler@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "david@fromorbit.com" , "jack@suse.cz" , "tytso@mit.edu" , "adilger.kernel@dilger.ca" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" , "linux-ext4@vger.kernel.org" , "xfs@oss.sgi.com" , "linux-kernel@vger.kernel.org" Date: Wed, 13 Apr 2016 08:10:27 -0600 In-Reply-To: <0255994B402DE243B1DFC1057A00655201AC6F@ZXSHMBX02.zhaoxin.com> References: <0255994B402DE243B1DFC1057A00655201AC6F@ZXSHMBX02.zhaoxin.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1171 Lines: 22 On Wed, 2016-04-13 at 13:44 +0000, Eric Shang wrote: > HI All: >   I meet an ext4 error, following is the error log. After panic, I check the > emmc by the tool debufs, the inode 69878 i_nlink is not zero. And this inode > don't belong to parent dir 6987, it belong to other file(this inode belong to > two files when check by debugfs ncheck), I guess than this inode has beed > deleted in memory and already used by other file. But the parent dentry > buff_head not flush to emmc. But when lookup this dentry can't find it' in > dentry cache, and then lookup_real, read the dentry from emmc, get the file > inode which already be deleted. >   Can any give me some help how to check this issue. My kernel version is 3.18 > form Android . I thinks something wrong with dentry cache flush and dirty > buff_head flush to emmc. Thanks all! Are you somehow using DAX and my dax_get_unmapped_area patches in your Android 3.18 kernel? I doubt this is the case, but I thought I should check since you reported it to me and Matthew with the same cc list. If you are simply using a distributed Android kernel, you should report it to Android email list or bug tracker. -Toshi