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 B996A364023 for ; Wed, 22 Apr 2026 10:31:56 +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=1776853916; cv=none; b=TB0a4Rar+R0Qk+xYDm2069pptSzkFczryjSGKAxCbnHDaIr/7986AvBfHoTURTEd/El4LH5RX/h+QGFt0g0y7lt64NF8mAJkU9jzongGaDPD5aRfNW7PMlwXaWR4O6UoKy69t7fCK2RI6NtpzJ0LvNUunh0OBlR4SjG/gec2vDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776853916; c=relaxed/simple; bh=auORzdCjJvvMpVrHWbHvzVmLzuyBkEv09gxaa6XyIu8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CUZ4KFlzxNx9GOCPqpIyh5W/Uhh8yv6pDOxQzeUCfB4stZTAkCcbD8xXf0xrA/hjGC/Nt+a+A4aaiKSObwfrg3k8zSfY1Qpj3Rfn+L6hQNNhy9IXnNcEGvgxQinRG77yGTfEBjj8ZPEEJFYDGK4VYrTzccIrQdFjxLwYBKGuO+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sfxmFJuy; 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="sfxmFJuy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18886C2BCF4; Wed, 22 Apr 2026 10:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776853916; bh=auORzdCjJvvMpVrHWbHvzVmLzuyBkEv09gxaa6XyIu8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sfxmFJuy4M8S5WLWKkL53XQQA+V0pLc1t1R2zeJdjQfsdRYrOj+0hmpFGtngTMrRL qzrYpLvvj3PB++gy2/gQfip0hQpw9s1vLq2zESkKWhtcIOz/osMt/C86fa9bOWnUcn SHdKrRvVWud35eUQFH163b6ExKzFy3/x4Jhs8M7McjiFDwza5S/J5srX/OAkxecA3v fKCOC8QOuI/16WeJhUzGi369TbueJJm31W7dUpeIFgwOM1hVpQlAxRmIT06aGS3x9o zMLaQapRdero0kaMf8hsnOQKUBMTw6v43n5CPm+L6fL/0B3TRygiQeG/TMSAGKejd0 AJFrS8SGAH5Mg== Date: Wed, 22 Apr 2026 12:31:52 +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 2/2] xfs: expose the current zonegc required status in sysfs Message-ID: References: <20260420135011.624587-4-cassel@kernel.org> <20260420135011.624587-6-cassel@kernel.org> <20260422060417.GD5391@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: <20260422060417.GD5391@lst.de> On Wed, Apr 22, 2026 at 08:04:17AM +0200, Christoph Hellwig wrote: > On Mon, Apr 20, 2026 at 03:50:14PM +0200, Niklas Cassel wrote: > > The current zonegc required status is currently available in > > /proc//mountstats (which contains stats for all mounted zoned XFS > > filesystems), under "RT GC required:". > > > > Add a sysfs attribute /sys/fs/xfs//zoned/zonegc_required for the same. > > This makes it trivial for monitoring software to read the value, for a > > specific filesystem, without any complex parsing. > > GC needed is a very complex internal condition, and I don't think > exposing the current value as a stable ABI is a good idea. So we have the following options: 1) /sys/fs/xfs//zoned/ 2) /sys/fs/xfs//stats/stats 3) /sys/kernel/debug/xfs// In my mind, debugfs is usually used for sensitive stuff, however, considering that the information exposed in this patch is exactly the same information as "GC required:" in /proc//mountstats, I assume that the sensitive argument is not really applicable here. Like you say, debugfs can also be used in order to avoid exposing the current value as a stable ABI. However, since the information exposed in this patch is accessed using the exact same function call: xfs_zoned_need_gc() as "GC required:" in /proc//mountstats, isn't the current value already exposed as a stable ABI? Or perhaps I am missing something here, and for some reason, unlike a sysfs attribute, the information exposed in /proc//mountstats is not considered a stable ABI ? That said, if you prefer 2) or 3) over 1) for exposing zonegc_required, please tell me which you prefer, and I can send a V2 with that. Kind regards, Niklas