From: Johannes Hirte <johannes.hirte@datenkhaos.de>
To: linux-btrfs@vger.kernel.org
Subject: failed to read block groups: Operation not permitted
Date: Tue, 6 Oct 2020 11:09:18 +0200 [thread overview]
Message-ID: <20201006090918.GA269054@latitude> (raw)
I recently encountered filesystem damage on a VM. During normal
operation, the filesystem was remounted ro suddenly. Dmesg showed me
some errors about parent transid verify failed. I've forced of the VM
and tried to mount the image on the host, but failed with:
[ 340.702391] BTRFS info (device loop0p1): disk space caching is enabled
[ 340.702393] BTRFS info (device loop0p1): has skinny extents
[ 341.815890] BTRFS error (device loop0p1): parent transid verify failed on 152064327680 wanted 323984 found 323888
[ 341.831183] BTRFS error (device loop0p1): parent transid verify failed on 152064327680 wanted 323984 found 323888
[ 341.831194] BTRFS error (device loop0p1): failed to read block groups: -5
[ 341.851954] BTRFS error (device loop0p1): open_ctree failed
A btrfs check resulted in:
btrfs check /dev/loop0p1
Opening filesystem to check...
parent transid verify failed on 152064327680 wanted 323984 found 323888
parent transid verify failed on 152064327680 wanted 323984 found 323888
parent transid verify failed on 152064327680 wanted 323984 found 323888
Ignoring transid failure
leaf parent key incorrect 152064327680
ERROR: failed to read block groups: Operation not permitted
ERROR: cannot open file system
The host is running libvirt with kvm, btrfs with RAID1. The VMs are raw
images, with btrfs too. I've switche this VM from io=native to
io=io_uring, and suspect that this caused the damage. All machines are
running kernel 5.8.13.
I was able to recover most of the damaged filesystem with btrfs recover.
Is there anything I can do for repair it? And why does the damage happen
at all with io_uring?
--
Regards,
Johannes Hirte
next reply other threads:[~2020-10-06 9:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-06 9:09 Johannes Hirte [this message]
2020-10-06 12:06 ` failed to read block groups: Operation not permitted Qu Wenruo
2020-10-08 9:24 ` Johannes Hirte
2020-10-08 9:35 ` Johannes Hirte
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