Re: WARNING in __kernel_write

syzbot has bisected this issue to:

commit 81238b2cff1469ff5b94390d026cd075105d6dcd
Author: Christoph Hellwig [off-list ref]
Date:   Thu May 7 17:33:03 2020 +0000

    fs: implement kernel_write using __kernel_write

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10d829bf100000
start commit:   be978f8f Add linux-next specific files for 20200713
git tree:       linux-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=12d829bf100000
console output: https://syzkaller.appspot.com/x/log.txt?x=14d829bf100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3fe4fccb94cbc1a6
dashboard link: https://syzkaller.appspot.com/bug?extid=e6f77e16ff68b2434a2c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11fe004f100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16d35f33100000

Reported-by: syzbot+e6f77e16ff68b2434a2c@syzkaller.appspotmail.com
Fixes: 81238b2cff14 ("fs: implement kernel_write using __kernel_write")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection