Hey, thank you! That was quick! Some comments inline below. On Mon, Feb 3, 2020 at 2:44 PM Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > > On 2020/2/3 下午9:33, Robert Klemme wrote: > > I have an issue with one of my desktop systems. Besides the usual > > information below I have attached output of btrfsck and dmesg. The > > system did not crash but was up for about a week. > > > > My questions: > > 1. And ideas what is wrong? > > One data extent lost its backref in extent tree. > So btrfs is unable to delete it, and will fallback to RO, to avoid > further corruption. > > I have no idea how this happened, but I'm pretty confident it's caused > by btrfs itself, not some hardware nor disk problems. I would assume as much as there were no power outages or crashes. I read about a bug recently (probably on https://www.reddit.com/r/btrfs/) that had to do with btrfs on LUKS and / or LVM. Could this be an explanation? > Any history about the fs? It may be caused by some older btrfs bug. > > > 2. Should I file a bug > > If you have an idea how to reproduce such problem. Not at the moment as I did not observe any unusual circumstances. Having the system up and running for a while is probably not a useful test. :-) > Or we can only help you to fix the fs, not really to locate the cause. OK, let's take that route. > > 3. can I safely repair with --repair or what else do I have to do to repair? > > Btrfs check --repair should be able to repair that, but not recommended > for your btrfs-progs version. > > There is a bug that any power loss or transaction abort in btrfs-progs > can further screw up your fs. That explains why a repair I recently attempted elsewhere did make things worse... > That bug is solved in v5.1 btrfs-progs. > I doubt it's backported for any btrfs-progs at all. > > So please use latest btrfs-progs to fix it. > A liveiso from some rolling distro would help. Is there a PPA? I could not find one so far. Thank you! robert > > Thanks, > Qu > > > > > Thank you! > > > > Kind regards > > > > robert > > > > This is a Xubuntu and I am using btrfs on top of lvm on top of LUKS. > > > > $ lsb_release -a > > No LSB modules are available. > > Distributor ID: Ubuntu > > Description: Ubuntu 18.04.3 LTS > > Release: 18.04 > > Codename: bionic > > $ uname -a > > Linux robunt-01 4.15.0-76-generic #86-Ubuntu SMP Fri Jan 17 17:24:28 > > UTC 2020 x86_64 x86_64 x86_64 GNU/Linux > > $ btrfs --version > > btrfs-progs v4.15.1 > > $ sudo btrfs fi show > > Label: none uuid: 0da6c6f7-d42e-4096-8690-97daf14d70e7 > > Total devices 1 FS bytes used 12.64GiB > > devid 1 size 30.00GiB used 15.54GiB path > > /dev/mapper/main--vg-main--root > > > > Label: 'home' uuid: cfb8c776-0dab-4596-af5b-276f0db46f79 > > Total devices 1 FS bytes used 50.73GiB > > devid 1 size 161.57GiB used 53.07GiB path > > /dev/mapper/main--vg-main--home > > > > $ sudo btrfs fi df / > > Data, single: total=14.01GiB, used=11.83GiB > > System, single: total=32.00MiB, used=16.00KiB > > Metadata, single: total=1.50GiB, used=820.30MiB > > GlobalReserve, single: total=39.19MiB, used=0.00B > > > -- [guy, jim, charlie, sho].each {|him| remember.him do |as, often| as.you_can - without end} http://blog.rubybestpractices.com/
