On my install, I've set my fstab entry for my btrfs mount points pass num to 0 so there is no attempt to run fsck.brtrfs on boot. btrfsck is still being developed, and I'm not sure it is wise to have a scan done automatically on boot... especially since its being developed in a tree on github titled "dangerdonteveruse"
[Phoronix] The Btrfs File-System Repair Tool Is Available- Code: Select all
# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
/dev/sda1 / btrfs defaults,subvol=@ 0 0
/dev/sda1 /home btrfs defaults,subvol=home 0 0