From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C4262F25F5 for ; Thu, 23 Apr 2026 09:14:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776935668; cv=none; b=l9hgrQ/9QGaQoA1Q+tsLW9GVxwciL2EVM1ed0+0tYR7M++HNQVv6uTZ0rtwyfzfMe9upp35jSUInce8w0HY+sAv6TaBGrSFxb6cOxp2PC/iMMjBl2sMO7i3A0QSd83OknWHin9wQwnqh2/egEOK/JGV7tGTAB96eQlOwGHZH0xc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776935668; c=relaxed/simple; bh=pG405HgpTHn8xSoGQOSjF0HV1vp1rsuTL+xmgci9u/Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ull0pFnXdHhD30brdk1UiS9MSlqaSfoeQNjbVvIXO73M3MGs4gXxZX0fdQZ8SxCKNPP95ySitnNX+5nOaIY5jeXcwDMesogM5nel7MbX62gfLX8hkH2vNVxLNnMR8AT2wOqlqrw4k9pbMJNgc/lDESjULjBc1cqsUwcVnSYwgdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OGpKRJ05; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OGpKRJ05" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD8FFC2BCAF; Thu, 23 Apr 2026 09:14:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776935668; bh=pG405HgpTHn8xSoGQOSjF0HV1vp1rsuTL+xmgci9u/Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OGpKRJ05uESfRZBJ7R3OXLjCl3NSeUJJ5KM9SzajOQhx9b9bNjoOHkLf6jfxChBK2 PdRQdML88VcVBisJbBhAh3hOfuJCRYzMDR/urC0Q+oEiwW5eKgvsGto1Ubc0D3M0QA Yh31LJYZZU0QpKmVUv79AKhNyhrUAelSmk+AC1KUozwyRYPkD+yqHhzrhuuTdG2Sp3 /zgoaeVeoROORNZulILBYhWZ90ZuZkF6rxA7Kqi6Y9kD0QZwjHIeVGN4usx+OUBrjb rcyY0BqyBrQI2QUXQFLjH+iNAYN1z5WDvBFPkDkDLhWfqAO1Rp6fbtLjpFICFgm3uY 3FioLjOzbj1TA== Date: Thu, 23 Apr 2026 11:14:24 +0200 From: Niklas Cassel To: Christoph Hellwig Cc: Carlos Maiolino , Damien Le Moal , Hans Holmberg , Johannes Thumshirn , linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/2] xfs: expose the number of free zones in sysfs Message-ID: References: <20260420135011.624587-4-cassel@kernel.org> <20260420135011.624587-5-cassel@kernel.org> <20260422060322.GC5391@lst.de> <20260423051142.GA27929@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260423051142.GA27929@lst.de> On Thu, Apr 23, 2026 at 07:11:42AM +0200, Christoph Hellwig wrote: > On Wed, Apr 22, 2026 at 12:29:14PM +0200, Niklas Cassel wrote: > > You say that the usual way to expose stats is through 2) > > but e.g. nr_open_zones is exposed via 1), introduced in commit > > 62c89988dc19 ("xfs: expose the number of open zones in sysfs") > > (You are the author of that commit btw :)) > > nr_open_zones is important for applications as it tells them how many > different placement points we can have. nr_free is really just > an implementation detail. The commit message for 62c89988dc19 ("xfs: expose the number of open zones in sysfs") motivated the change by saying that nr_open_zones could be used in monitoring or testing software. Which seemed like the same reason/purpose why I wanted to add nr_free_zones. Your commit message did not mention that user space software could also use nr_open_zones to calculate the number of different placement points. Anyway, I can continue with the current (somewhat fragile) way of parsing /proc//mountstats. It is just a bit unfortunate that you can't get it for a specific mountpoint only. The "mountstats" command: https://man7.org/linux/man-pages/man8/mountstats.8.html seems to be able to display the mountstats for a specific mountpoint only, but it seems to be for NFS only. Carlos, please disregard this series. Kind regards, Niklas