After installing Linux 4.12-rc7 mainline I'm seeing more than 100 messages in the form of
[ 1066.717576] btrfs_printk: 22 callbacks suppressed [ 1066.717579] BTRFS warning (device sda5): unhandled fiemap cache detected: offset=0 phys=2900758618112 len=131072 flags=0x8
dmesg with different
phys values. What does that mean? Of course primarily I'm interested whether this calls for a repair or optimization, but also what it actually means in BTRFS's structure.
I'm using Ubuntu 17.04.