Re: Uncorrectable errors after rebooting with Magic Sysrq Keys

["Niccolò Belli" <darkbasic@linuxsystems.it>]

Finally my external drive arrived and I've been able to make a backup and 
try btrfs check --repair.
Unfortunately btrfs check --repair got stuck in an infinite loop like this 
one (https://www.spinics.net/lists/linux-btrfs/msg54146.html) and after 
several hours of looping and several Gigabytes of logs I had to kill it, 
which gave me a completely fucked fs.
I still have backup images, so I can restore the old state and try again 
with updated tools (I used latest btrfs-progs 4.5.1, but I also tried 
4.4.1).
For those who didn't read the whole thread I can mount the fs, but it hangs 
while trying to read certain files and sometimes it remounts read-only. I'm 
pretty sure the culprit was a bug in 4.6-rc because problems started 
roughly after upgrading. Disk (an SSD) is fine. The fs is on top of 
dm-crypt and I always mounted it with 
"rw,relatime,ssd,space_cache,discard,compress=lzo,autodefrag".

You can find the whole logs here: 
https://drive.google.com/open?id=0Bwe9Wtc-5xF1Z2YwN1Y4U0ROSUU

01_scrub is the scrub output
02_check is the btrfs check output (14MB)
03_repair_short is the btrfs check --repair output truncated to 14MB

I hope someone will be able to help me recover my data, otherwise I will 
have to backup just the most important files and reinstall the whole system 
from scratch. Mounting the fs and doing a backup with cp -a wasn't a viable 
solution because it got stuck after several GBs.

Niccolò

P.S.
I changed my spf/dkim/dmarc settings, this email should no longer go into 
the spam folder, if it does please let me know. Thanks.