On Mon, Feb 27, 2017 at 07:53:48AM -0800, Liu Bo wrote:
 > On Sun, Feb 26, 2017 at 07:18:42PM -0500, Dave Jones wrote:
 > > Hitting this fairly frequently.. I'm not sure if this is the same bug I've
 > > been hitting occasionally since 4.9. The assertion looks new to me at least.
 > >
 > 
 > It was recently introduced by my commit and used to catch data loss at truncate.
 > 
 > Were you running the test with a mkfs.btrfs -O NO_HOLES?
 > (We just queued a fix for the NO_HOLES case in btrfs-next.)

No, a fs created with default mkfs.btrfs options.

	Dave