Re: WARNING in percpu_ref_exit (2)

syzbot suspects this issue was fixed by commit:

commit c1e2148f8ecb26863b899d402a823dab8e26efd1
Author: Jens Axboe [off-list ref]
Date:   Wed Mar 4 14:25:50 2020 +0000

    io_uring: free fixed_file_data after RCU grace period

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=161ea46e500000
start commit:   63849c8f Merge tag 'linux-kselftest-5.6-rc5' of git://git...
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=4527d1e2fb19fd5c
dashboard link: https://syzkaller.appspot.com/bug?extid=8c4a14856e657b43487c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13c30061e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1251b731e00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: io_uring: free fixed_file_data after RCU grace period

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