Hi,

Bernhard Bock [off-list ref] wrote:

I found one of our servers with a read-only btrfs this morning.
dmesg says:

BTRFS critical (device dm-1): corrupt leaf: block=6404379377664  
slot=66 extent bytenr=3138606432256 len=18446619972284938920 invalid  
extent length, have 18446619972284938920 expect aligned to 4096
...
BTRFS error (device dm-1): block=6404379377664 write time tree block  
corruption detected

looks like all is well.

After a reboot, btrfsck didn't find any errors any more. Additionally,
btfs-scrub also completed without errors.

Seems like the write time btrfs corruption checks found everything before
committing to disk. Possibly a memory error despite ECC RAM?

To any future readers having similar problems: Do not trust any checks / log
statements before reboot if you encounter possible btrfs corruption.

All the best,
Bernhard