Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 18 Jan 2023 11:50:26 -0500
From:   Brian Foster <bfoster@redhat.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>,
        Hugh Dickins <hughd@google.com>, linux-afs@lists.infradead.org,
        linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org,
        cluster-devel@redhat.com, linux-mm@kvack.org,
        linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-nilfs@vger.kernel.org
Subject: Re: [PATCH 4/9] shmem: remove shmem_get_partial_folio
Message-ID: <Y8gjUhcRYkRuxLDq@bfoster>
References: <20230118094329.9553-1-hch@lst.de>
 <20230118094329.9553-5-hch@lst.de>
 <Y8f6sShghKuFim5E@bfoster>
 <20230118164358.GD7584@lst.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230118164358.GD7584@lst.de>
Precedence: bulk

On Wed, Jan 18, 2023 at 05:43:58PM +0100, Christoph Hellwig wrote:
> On Wed, Jan 18, 2023 at 08:57:05AM -0500, Brian Foster wrote:
> > This all seems reasonable to me at a glance, FWIW, but I am a little
> > curious why this wouldn't split up into two changes. I.e., switch this
> > over to filemap_get_entry() to minimally remove the FGP_ENTRY dependency
> > without a behavior change, then (perhaps after the next patch) introduce
> > SGP_FIND in a separate patch. That makes it easier to review and
> > potentially undo if it happens to pose a problem in the future. Hm?
> 
> The minimal change to filemap_get_entry would require to add the
> lock, check mapping and retry loop and thus add a fair amount of
> code.  So I looked for ways to avoid that and came up with this
> version.  But if there is a strong preference to first open code
> the logic and then later consolidate it I could do that.
> 

Ok. Not a strong preference from me. I don't think it's worth
complicating that much just to split up.

Brian