Hi, I have a raid10-like setup that is failing to mount in rw mode with the error
mount: /mnt/media: wrong fs type, bad option, bad superblock on /dev/mapper/em1, missing codepage or helper program, or other error read-only mounts seem to work and the files seem to be there. I started having issues after a system crash during the process of deleting a number of large files. After this (Ubuntu 16.04/Kernel 4.4), any attempt to mount the array in rw mode would cause a similar crash. I did an upgrade to Ubuntu 18.04/Kernel 4.15 and now get the error above. I have looked through a variety of posts on the mailing list, but couldn't find anything with the same issue. I have done a scrub on the array that resulted in 6 verify errors with dmesg showing something about extent trees. It didn't list them as uncorrectable errors, but couldn't correct them either as I can't mount in rw. I also tried `btrfs rescue zero-log /dev/mapper/em1`, which changes the above to (say) em5, but then zero-log on em5 causes it to go back to em1. Any direction would be appreciated. From what I could tell, my next steps would be a check with --repair or --init-extent-tree, though I'm reluctant to try those without being explicitly told to do so. I have attached a dmesg.log file and hope I haven't greped out anything important. Thanks, Daniel -- Daniel Underwood
dmesg.log
Description: Binary data
