Re: [syzbot] possible deadlock in f2fs_write_checkpoint

[syzbot]

syzbot has bisected this issue to:

commit e4544b63a7ee49e7fbebf35ece0a6acd3b9617ae
Author: Tim Murray <timmurray@xxxxxxxxxx>
Date:   Fri Jan 7 20:48:44 2022 +0000

    f2fs: move f2fs to use reader-unfair rwsems

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=108e6078700000
start commit:   6abab1b81b65 Add linux-next specific files for 20220202
git tree:       linux-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=128e6078700000
console output: https://syzkaller.appspot.com/x/log.txt?x=148e6078700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b8d8750556896349
dashboard link: https://syzkaller.appspot.com/bug?extid=0b9cadf5fc45a98a5083
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12de9cb8700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11953798700000

Reported-by: syzbot+0b9cadf5fc45a98a5083@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: e4544b63a7ee ("f2fs: move f2fs to use reader-unfair rwsems")

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