FM / btrfs-control

/sys/devices/virtual/misc/btrfs-control

Name	Size	Mode	Actions
power/	-	0755	rm
subsystem/	-	0755	rm
dev	4096	0444	edit dl rm
uevent	4096	0644	edit dl rm

Edit: /sys/devices/virtual/misc/btrfs-control/uevent (4096B)

MAJOR=10 MINOR=234 DEVNAME=btrfs-control