Received-SPF: pass (google.com: best guess record for domain of linux-ext4-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 26 Feb 2020 07:55:21 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Kirill Tkhai <ktkhai@virtuozzo.com>
Cc:     tytso@mit.edu, viro@zeniv.linux.org.uk, adilger.kernel@dilger.ca,
        snitzer@redhat.com, jack@suse.cz, ebiggers@google.com,
        riteshh@linux.ibm.com, krisman@collabora.com, surajjs@amazon.com,
        dmonakhov@gmail.com, mbobrowski@mbobrowski.org, enwlinux@gmail.com,
        sblbir@amazon.com, khazhy@google.com, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH RFC 5/5] ext4: Add fallocate2() support
Message-ID: <20200226155521.GA24724@infradead.org>
References: <158272427715.281342.10873281294835953645.stgit@localhost.localdomain>
 <158272447616.281342.14858371265376818660.stgit@localhost.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <158272447616.281342.14858371265376818660.stgit@localhost.localdomain>
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

On Wed, Feb 26, 2020 at 04:41:16PM +0300, Kirill Tkhai wrote:
> This adds a support of physical hint for fallocate2() syscall.
> In case of @physical argument is set for ext4_fallocate(),
> we try to allocate blocks only from [@phisical, @physical + len]
> range, while other blocks are not used.

Sorry, but this is a complete bullshit interface.  Userspace has
absolutely no business even thinking of physical placement.  If you
want to align allocations to physical block granularity boundaries
that is the file systems job, not the applications job.