Re: [lkp] [nfsd] b44061d0b9: BUG: Dentry ffff880027d7c540{i=1846f,n=0a} still in use (1) [unmount of btrfs vda]

[Linus Torvalds]

On Tue, Aug 9, 2016 at 10:39 PM, kernel test robot
<xiaolong.ye@xxxxxxxxx> wrote:
>
> [ 1537.558739] nfsd: last server has exited, flushing export cache
> [ 1540.627795] BUG: Dentry ffff880027d7c540{i=1846f,n=0a}  still in use (1) [unmount of btrfs vda]
> [ 1540.633915] ------------[ cut here ]------------
> [ 1540.636551] WARNING: CPU: 0 PID: 20552 at fs/dcache.c:1474 umount_check+0x72/0x80

Hmm. Adding Al and the btrfs people to the cc, and expanding the nfs
list. Unlike the flakey-IO warning, this one sounds like a real issue.
Whether it's some dentry leak by nfsd or a VFS or btrfs issue, I can't
begin to guess. Al, ideas?

More information in the original email on lkml.

                 Linus