On 08/03/2017 11:25 AM, Wang Shilong wrote:

On Thu, Aug 3, 2017 at 11:00 PM, Chris Mason [off-list ref] wrote:

quoted

On 07/27/2017 02:52 PM, fdmanana@kernel.org wrote:

quoted

From: Filipe Manana <redacted>

If the range being cleared was not marked for defrag and we are not
about to clear the range from the defrag status, we don't need to
lock and unlock the inode.

Signed-off-by: Filipe Manana <redacted>

Thanks Filipe, looks like it goes all the way back to:

commit 47059d930f0e002ff851beea87d738146804726d
Author: Wang Shilong [off-list ref]
Date:   Thu Jul 3 18:22:07 2014 +0800

     Btrfs: make defragment work with nodatacow option

I can't see how the inode lock is required here.

This blames to me, thanks for fixing it.

No blame ;)  I'll take code that works any day.

-chris