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Subject: Re: [PATCH 1/2] netfs: release the folio lock and put the folio
 before retrying
To:     David Howells <dhowells@redhat.com>,
        Jeff Layton <jlayton@kernel.org>
Cc:     idryomov@gmail.com, vshankar@redhat.com,
        linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org,
        willy@infradead.org, keescook@chromium.org,
        linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com
References: <30a4bd0e19626f5fb30f19f0ae70fba2debb361a.camel@kernel.org>
 <20220701022947.10716-1-xiubli@redhat.com>
 <20220701022947.10716-2-xiubli@redhat.com>
 <2187946.1657027284@warthog.procyon.org.uk>
From:   Xiubo Li <xiubli@redhat.com>
Message-ID: <8ce8c30f-8a33-87e7-1bdc-b73d5b933c85@redhat.com>
Date:   Wed, 6 Jul 2022 08:58:40 +0800
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On 7/5/22 9:21 PM, David Howells wrote:
> Jeff Layton <jlayton@kernel.org> wrote:
>
>> I don't know here... I think it might be better to just expect that when
>> this function returns an error that the folio has already been unlocked.
>> Doing it this way will mean that you will lock and unlock the folio a
>> second time for no reason.
> I seem to remember there was some reason you wanted the folio unlocking and
> putting.  I guess you need to drop the ref to flush it.
>
> Would it make sense for ->check_write_begin() to be passed a "struct folio
> **folio" rather than "struct folio *folio" and then the filesystem can clear
> *folio if it disposes of the page?

Yeah, this also sounds good to me.

-- Xiubo


> David
>