On 2020/2/3 下午9:58, Robert Klemme wrote: > 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? No, it should only be some bug inside btrfs, nothing to do with lower stack. > >> 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. For "some rolling distro", I mean Arch... Since you're just going to repair the fs, no need to stick to Ubuntu. Thanks, Qu > > 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 >>> >> > >
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