Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 23 Mar 2023 15:14:59 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Hans Holmberg <hans.holmberg@wdc.com>, Chao Yu <chao@kernel.org>,
        linux-f2fs-devel@lists.sourceforge.net, damien.lemoal@wdc.com,
        aravind.ramesh@wdc.com, hans@owltronix.com,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] f2fs: preserve direct write semantics when buffering
 is forced
Message-ID: <ZBzPYwcoLXkFngz8@google.com>
References: <20230220122004.26555-1-hans.holmberg@wdc.com>
 <ZBhisCo7gTitmKeO@infradead.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZBhisCo7gTitmKeO@infradead.org>
Precedence: bulk

On 03/20, Christoph Hellwig wrote:
> On Mon, Feb 20, 2023 at 01:20:04PM +0100, Hans Holmberg wrote:
> > A) Supporting proper direct writes for zoned block devices would
> > be the best, but it is currently not supported (probably for
> > a good but non-obvious reason). Would it be feasible to
> > implement proper direct IO?
> 
> I don't think why not.  In many ways direct writes to zoned devices
> should be easier than non-direct writes.
> 
> Any comments from the maintainers why the direct I/O writes to zoned
> devices are disabled?  I could not find anything helpful in the comments
> or commit logs.

The direct IO wants to overwrite the data on the same block address, while
zoned device does not support it?