From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:52239 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751538AbdFIUKs (ORCPT ); Fri, 9 Jun 2017 16:10:48 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1dJQEz-0007bo-46 for linux-btrfs@vger.kernel.org; Fri, 09 Jun 2017 22:10:41 +0200 To: linux-btrfs@vger.kernel.org From: Koen Kooi Subject: Re: Filesystem won't mount (open_ctree failed) or repair (BUG_ON) Date: Fri, 9 Jun 2017 22:10:40 +0200 Message-ID: References: <20170609195718.GC30723@carfax.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <20170609195718.GC30723@carfax.org.uk> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Op 09-06-17 om 21:57 schreef Hugo Mills: > On Fri, Jun 09, 2017 at 09:12:16PM +0200, Koen Kooi wrote: >> Hi, >> >> Today the kernel got wedged during shutdown (4.11.x tends to do that, haven't >> debugged) and I pressed the reset button. The next boot btrfs won't mount: >> >> [Fri Jun 9 20:46:07 2017] BTRFS error (device md0): parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> [Fri Jun 9 20:46:07 2017] BTRFS error (device md0): parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> [Fri Jun 9 20:46:07 2017] BTRFS error (device md0): failed to read block groups: -5 >> [Fri Jun 9 20:46:08 2017] BTRFS error (device md0): open_ctree failed > > With a transid failure on mount, about the only thing that's likely > to work is mounting with -o usebackuproot. If that doesn't work, then > a rebuild of the FS is almost certainly needed. Hrm, that is also a no-go: # mount /dev/md0 /media/data/ -o usebackuproot [ 740.294141] BTRFS info (device md0): trying to use backup root at mount time [ 740.294145] BTRFS info (device md0): using free space tree [ 740.294146] BTRFS info (device md0): has skinny extents [ 754.248228] BTRFS error (device md0): parent transid verify failed on 5840011722752 wanted 170755 found 170832 [ 754.449435] BTRFS error (device md0): parent transid verify failed on 5840011722752 wanted 170755 found 170832 [ 754.449527] BTRFS error (device md0): failed to read block groups: -5 [ 754.609960] BTRFS error (device md0): open_ctree failed So, any more suggestions of things to try? regards, Koen > > Hugo. > >> I tried repair, but that didn't work either: >> >> # btrfsck --repair /dev/md0 >> enabling repair mode >> couldn't open RDWR because of unsupported option features (3). >> ERROR: cannot open file system >> enabling repair mode >> >> Googling around it was suggested clearing the v2 space cache: >> >> # btrfsck --mode=lowmem --clear-space-cache v2 /dev/md0 >> parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> parent transid verify failed on 5840011722752 wanted 170755 found 170832 >> Ignoring transid failure >> leaf parent key incorrect 5840011722752 >> parent transid verify failed on 5367057465344 wanted 170755 found 170828 >> parent transid verify failed on 5367057465344 wanted 170755 found 170828 >> parent transid verify failed on 5367057465344 wanted 170755 found 170828 >> parent transid verify failed on 5367057465344 wanted 170755 found 170828 >> Ignoring transid failure >> leaf parent key incorrect 72105984 >> btrfs unable to find ref byte nr 4628577484800 parent 0 root 10 owner 0 offset 1 >> parent transid verify failed on 5366993256448 wanted 170755 found 170827 >> parent transid verify failed on 5366993256448 wanted 170755 found 170827 >> parent transid verify failed on 5366993256448 wanted 170755 found 170827 >> parent transid verify failed on 5366993256448 wanted 170755 found 170827 >> Ignoring transid failure >> leaf parent key incorrect 41287680 >> ERROR: failed to clear free space cache v2: -1 >> transaction.h:41: btrfs_start_transaction: BUG_ON `root->commit_root` triggered, value 22938400 >> btrfs check[0x411674] >> btrfs check(close_ctree_fs_info+0x125)[0x41368c] >> btrfs check(cmd_check+0x36d8)[0x45e8e8] >> btrfs check(main+0x15d)[0x40ac5c] >> /lib/libc.so.6(__libc_start_main+0xf0)[0x7f9b4cb060d0] >> btrfs check[0x40a729] >> Clear free space cache v2 >> >> The underlying md0 (raid6) doesn't report any errors, trying different kernels makes no difference, 4.10.17, 4.11.4 and 4.12.0-rc4 all give the same errors. Everything above was >> done with btrfs-progs 4.11. >> >> Any hints on how I can fix the errors in the filesystem? I don't mind loosing todays changes, but I would like to keep all the older data :) >> >> regards, >> >> Koen >> >