On Wed, Aug 15, 2012 at 04:29:53PM +0800, Anand jain wrote:

From: Anand Jain <redacted>

btrfs f l /
No valid Btrfs found on /
Segmentation fault (core dumped)

Patches fixing this have been sent like 4 times, last one was from
Alexander's 'btrfs prop', that modified it a bit more (to return the
label instead of printing it).

http://permalink.gmane.org/gmane.comp.file-systems.btrfs/18287

while Danny fixes more instances of unhandled error code from open_ctree

http://permalink.gmane.org/gmane.comp.file-systems.btrfs/15305

JFYI,
david