From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-2.arkena.net ([95.81.173.75]:50624 "EHLO smtp-2.arkena.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751057AbcAGQjl (ORCPT ); Thu, 7 Jan 2016 11:39:41 -0500 Received: from [10.201.4.47] (unknown [10.201.4.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-2.arkena.net (Postfix) with ESMTPSA id 3pbtZL5z8MzHkDZ for ; Thu, 7 Jan 2016 16:39:38 +0000 (UTC) Subject: Re: Broken RAID6, segfault on chunk-recover To: linux-btrfs@vger.kernel.org References: <568A7460.6070607@zeroloop.net> <9e61601b1589f0fd9381dc9cf0232e0e@mail.zeroloop.net> From: Abe Message-ID: <568E94CA.4070907@zeroloop.net> Date: Thu, 7 Jan 2016 17:39:38 +0100 MIME-Version: 1.0 In-Reply-To: <9e61601b1589f0fd9381dc9cf0232e0e@mail.zeroloop.net> Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: No wonder why chunck-recover crashed, superblocks are valid but they all contain a bogus chunk_root, it exceeds the total_bytes ! So all I need it to find where that btree root is on disk, right? Problem is almost every tool from btrfs-progs is unusuable because they try to read the chunck root at first. Do you know of any alternative tool that could scan devices and find where roots might be? All superblock copies for all devices look like this : # ./btrfs-show-super /dev/sdb1 superblock: bytenr=65536, device=/dev/sdb1 --------------------------------------------------------- csum 0x938855ef [match] bytenr 65536 flags 0x1 ( WRITTEN ) magic _BHRfS_M [match] fsid bec7b9a0-c56c-494e-8631-072d3f89c0c9 label hive generation 34245 root 6766859681792 sys_array_size 321 chunk_root_generation 32751 root_level 1 chunk_root 4415566151680 <--- Impossible Offset chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 4096872997376 <--- bytes_used 2438972817408 sectorsize 4096 nodesize 16384 leafsize 16384 stripesize 4096 root_dir 6 num_devices 8 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x1e1 ( MIXED_BACKREF | BIG_METADATA | EXTENDED_IREF | RAID56 | SKINNY_METADATA ) csum_type 0 csum_size 4 cache_generation 34245 uuid_tree_generation 34245 dev_item.uuid ea4a089b-c88c-4a6c-80e5-b2c93f0613f5 dev_item.fsid bec7b9a0-c56c-494e-8631-072d3f89c0c9 [match] dev_item.type 0 dev_item.total_bytes 512109125120 dev_item.bytes_used 349754621952 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 5 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 Best regards,