When configuring kernel for hibernation,
RESUME boot option has to be provided with UUID for the swap partition.
If you're using a sawpfile instead of a swap partition, you have to go through a lot of hoops and still it isn't a stable setup if you're on SSD which trims regularly.
btrfs subvolumes also have UUIDs. I'm wondering, if I could use a subvolume as a swap partition for all intents and purposes? (or house a single swapfile in it. weirdly,
mkswap also output a UUID when making the swapfile, which confused me a little)
I have no idea if the btrfs-related modules are loaded first or if kernel just wants to read blocks directly from disk first before doing anything else. Is this possible?