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References: <20221117115023.1350181-1-dwysocha@redhat.com> <20221117115023.1350181-2-dwysocha@redhat.com>
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From:   David Wysochanski <dwysocha@redhat.com>
Date:   Thu, 17 Nov 2022 09:10:57 -0500
Message-ID: <CALF+zOme4qF1y5ZLuhNO8Cahn-YCDnNCRQ4WN75C9cp69B6KPA@mail.gmail.com>
Subject: Re: [PATCH 1/1] fscache: Fix oops due to race with cookie_lru and use_cookie
To:     David Howells <dhowells@redhat.com>
Cc:     Daire Byrne <daire.byrne@gmail.com>,
        Benjamin Maynard <benmaynard@google.com>,
        linux-cachefs@redhat.com, linux-nfs@vger.kernel.org
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On Thu, Nov 17, 2022 at 8:52 AM David Howells <dhowells@redhat.com> wrote:
>
> Dave Wysochanski <dwysocha@redhat.com> wrote:
>
> > +             clear_bit(FSCACHE_COOKIE_DO_LRU_DISCARD, &cookie->flags);
>
> Actually, can you do test_and_clear_bit() and then log a trace point, say:
>
>         fscache_see_cookie(cookie, fscache_cookie_see_lru_discard_cancel);
>
> if the bit was set.
>
> David
>

Ok sure.  I will post a v2 with the trace point and the test_and_clear_bit.