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Date:   Thu, 23 Mar 2023 15:33:19 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Pankaj Raghav <p.raghav@samsung.com>
Cc:     senozhatsky@chromium.org, viro@zeniv.linux.org.uk, axboe@kernel.dk,
        brauner@kernel.org, akpm@linux-foundation.org, minchan@kernel.org,
        hubcap@omnibond.com, martin@omnibond.com, mcgrof@kernel.org,
        devel@lists.orangefs.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-block@vger.kernel.org, gost.dev@samsung.com
Subject: Re: [RFC v2 0/5] remove page_endio()
Message-ID: <ZBxxPw9BTdkE4KF0@casper.infradead.org>
References: <CGME20230322135015eucas1p2ff980e76159f0ceef7bf66934580bd6c@eucas1p2.samsung.com>
 <20230322135013.197076-1-p.raghav@samsung.com>
 <ZBtSevjWLybE6S07@casper.infradead.org>
 <fbf5bc8a-6c82-a43e-dd96-8a9d2b7d3bf4@samsung.com>
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On Thu, Mar 23, 2023 at 04:00:37PM +0100, Pankaj Raghav wrote:
> > We don't need to set the error flag.  Only some filesystems still use
> > the error flag, and orangefs isn't one of them.  I'd like to get rid
> > of the error flag altogether, and I've sent patches in the past which
> > get us a lot closer to that desired outcome.  Not sure we're there yet.
> > Regardless, generic code doesn't check the error flag.
> 
> Thanks for the explanation. I think found the series you are referring here.
> 
> https://lore.kernel.org/linux-mm/20220527155036.524743-1-willy@infradead.org/#t
> 
> I see orangefs is still setting the error flag in orangefs_read_folio(), so
> it should be removed at some point?

Yes, OrangeFS only sets the error flag, it never checks it, so it never
needs to set it.

> I also changed mpage to **not set** the error flag in the read path. It does beg
> the question whether block_read_full_folio() and iomap_finish_folio_read() should
> also follow the suit.

Wrong.  mpage is used by filesystems which *DO* check the error flag.
You can't remove it being set until they're fixed to not check it.