Greetings.. I was running btrfs receive to apply snapshots from another machine and the receiving machine locked up with only a few KB received (tracked with pv). I left it for ~ 4 hours with no change, and tried to abort the receive and it would not exit. I then tried to "ls -al" on the snapshot directory and that froze as well. I then triggered a sysrq w, and have pastebined the latter section of the output: https://pastebin.com/fQFWq307 (I included everything after boot, there was no abnormal bits in the boot and I didn't want to have to filter everything for PII) Now it is ~16 hours later and both the "btrfs receive" and "ls" processes are still locked in "D" state, but I don't know if I should just reboot the machine (preferably not with a hard reset) or not. I do have a keyboard attached so I can possibly do a SysRq forced unmount if provided with "safe" instruction as I have never done that before. I do find that I can list files in other snapshot subvolumes, so the base FS isn't completely blocked, but is around this new snapshot. Other (possibly pertinent) info: - Both machines are running the latest ArchLinux provided kernel of 4.19.8-arch1 and btrfs-progs 4.19-1 - The receiving machine had just replaced a failing disk with a new one (via btrfs disk replace) and all indications were that it completed successfully, correcting errors reading from the old disk as they were encountered. - I had also just deleted two snapshots which were of suspect completeness and was re-sending one of those. So that is the scenario. Happy to get more logs if needed, but would welcome advice on how to proceed. Thanks, - mike
