[PROBLEM] btrfs: mmcblk0p2 checksum verify failed

[mk01]

do you have anything connected in to the RPI ports without external power adapter (other as the usb mouse)?

seeing the boot time you don't have it even clocked higher than the default.

normally OC problem or memory or similar would just report lots of checksum errors, doing RO remount at the end. but you also have two unfinished IO operations aborted with error. this could mean SD card failing.

btrfs currently doesn't implement classical fsck, but … ok I'm not right anymore. checked "btrfs" man page currently and there are more options:
1) btrfs check [options] <device>
Check an unmounted btrfs filesystem.

- so you could drop to recovery shell (initramfs) and do the check on unmounted fs. you can invoke recovery shell by holding left shift key during initramfs stage, or by putting "rescue" into cmdline.txt

2) btrfs scrub start [-BdqrR] [-c ioprio_class -n ioprio_classdata] <path>|<device>
Start a new scrub
btrfs scrub cancel <path>|<device>
Cancel a running scrub
btrfs scrub resume [-BdqrR] [-c ioprio_class -n ioprio_classdata] <path>|<device>
Resume previously canceled or interrupted scrub
btrfs scrub status [-dR] <path>|<device>
Show status of running or finished scrub

- scrub is supposed for online run, should recheck all data against existing checksums.

this kind of errors are very rare since XBian went for btrfs (few month back). maybe I remember three or four. I experienced it once when clocked my RPI to 980,500,500 (normally running 920,420,500).

report back please.