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From:   Daeho Jeong <daeho43@gmail.com>
Date:   Wed, 27 Oct 2021 11:36:41 -0700
Message-ID: <CACOAw_xunxNZz9zNHOJgLzWsGRnKHvpum5+kkizrx8pKCtgqaw@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH] f2fs: remove circular locking between
 sb_internal and fs_reclaim
To:     Chao Yu <chao@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com,
        Daeho Jeong <daehojeong@google.com>
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On Tue, Oct 26, 2021 at 10:56 AM Daeho Jeong <daeho43@gmail.com> wrote:
>
> > Yes, I doubt the problem may also happen in f2fs_evict_inode() with below
> > callpath:
> >
> > - evict_inode
> >   - dquot_initialize failed
> >   - sb_start_intwrite
> >   - f2fs_truncate
> >    - dquot_initialize lock dqio_sem
> >
> > How about this?
> >
>
> Got it~
> Then we need this in both f2fs_evict_inode() and f2fs_drop_inode().
>

It turns out this deadlock issue was related to the Android kernel only. :(
That was related to one of Android tracepoints, which triggered
internal memory reclaim inside of it.
We made a workaround for that in Android kernel.

Thanks,