Comment 24 for bug 1788321

Fixed my problem.

While looking through /var/log/syslog, I noticed this line around the same time swap mount failed.

BTRFS warning (device sda3): swapfile must not be copy-on-write

Then a few lines later...

systemd[1]: swap.img.swap: Failed with result 'exit-code'.
systemd[1]: Failed to activate swap /swap.img.
systemd[1]: Dependency failed for Swap.
systemd[1]: swap.target: Job swap.target/start failed with result 'dependency'.

Yes my root is on btrfs and I did not see this error before. So I deleted /swap.img and started over.

$ sudo rm -rf /swap.img
$ sudo touch /swap.img
$ sudo chattr +C /swap.img
$ sudo fallocate -l 2G /swap.img
$ sudo chmod 600 /swap.img
$ sudo mkswap /swap.img
$ sudo swapon /swap.img

No error and "swapon --show" gives this:

NAME TYPE SIZE USED PRIO
/swap.img file 2G 0B -2

Just what I was expecting. So problem solved for me, maybe a check can be put in to see if it's on btrfs and apply the 'chattr +C' option.