Re: possible deadlock in flush_workqueue (2)

syzbot suspects this bug was fixed by commit:

commit e7c58097793ef15d58fadf190ee58738fbf447cd
Author: Mike Kravetz [off-list ref]
Date:   Tue Jan 8 23:23:32 2019 +0000

     hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate race"

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14ec0d2c600000
start commit:   ca9eb48f Merge tag 'regulator-v5.0' of git://git.kernel.or..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=963b24abf3f7c2d8
dashboard link: https://syzkaller.appspot.com/bug?extid=a50c7541a4a55cd49b02
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12097f03400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10b55ac5400000

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

#syz fix: hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate  
race"

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