From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:45400 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbcJKOEx (ORCPT ); Tue, 11 Oct 2016 10:04:53 -0400 Date: Tue, 11 Oct 2016 07:09:49 -0700 From: Liu Bo To: dsterba@suse.cz Cc: aron@aron.ws, linux-btrfs@vger.kernel.org Subject: Re: corrupt leaf, slot offset bad Message-ID: <20161011140949.GA5284@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <57e7870b981160be5fabc63c4967e90f@aron.ws> <20161010210346.GA8381@localhost.localdomain> <20161011124809.GN11398@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20161011124809.GN11398@twin.jikos.cz> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Oct 11, 2016 at 02:48:09PM +0200, David Sterba wrote: > Hi, > > looks like a lot of random bitflips. > > On Mon, Oct 10, 2016 at 11:50:14PM +0200, aron@aron.ws wrote: > > item 109 has a few strange chars in its name (and it's truncated): > > 1-x86_64.pkg.tar.xz 0x62 0x14 0x0a 0x0a > > > > item 105 key (261 DIR_ITEM 54556048) itemoff 11723 itemsize 72 > > location key (606286 INODE_ITEM 0) type FILE > > namelen 42 datalen 0 name: python2-gobject-3.20.1-1-x86_64.pkg.tar.xz > > item 106 key (261 DIR_ITEM 56363628) itemoff 11660 itemsize 63 > > location key (894298 INODE_ITEM 0) type FILE > > namelen 33 datalen 0 name: unrar-1:5.4.5-1-x86_64.pkg.tar.xz > > item 107 key (261 DIR_ITEM 66963651) itemoff 11600 itemsize 60 > > location key (1178 INODE_ITEM 0) type FILE > > namelen 30 datalen 0 name: glibc-2.23-5-x86_64.pkg.tar.xz > > item 108 key (261 DIR_ITEM 68561395) itemoff 11532 itemsize 68 > > location key (660578 INODE_ITEM 0) type FILE > > namelen 38 datalen 0 name: squashfs-tools-4.3-4-x86_64.pkg.tar.xz > > item 109 key (261 DIR_ITEM 76859450) itemoff 11483 itemsize 65 > > location key (2397184 UNKNOWN.0 7091317839824617472) type 45 > > namelen 13102 datalen 13358 name: 1-x86_64.pkg.tar.xzb > > namelen must be smaller than 255, but the number itself does not look > like a bitflip (0x332e), the name looks like a fragment of. > > The location key is random garbage, likely an overwritten memory, > 7091317839824617472 == 0x62696c0100230000 contains ascii 'bil', the key > type is unknown but should be INODE_ITEM. > > > data > > item 110 key (261 DIR_ITEM 9799832789237604651) itemoff 11405 itemsize > > 62 > > location key (388547 INODE_ITEM 0) type FILE > > namelen 32 datalen 0 name: intltool-0.51.0-1-any.pkg.tar.xz > > item 111 key (261 DIR_ITEM 81211850) itemoff 11344 itemsize 131133 > > itemsize 131133 == 0x2003d is a clear bitflip, 0x3d == 61, corresponds > to the expected item size. > > There's possibly other random bitflips in the keys or other structures. > It's hard to estimate the damage and thus the scope of restorable data. It makes sense since this's a ssd we may have only one copy for metadata. Thanks, -liubo