From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 E72303E00A5 for ; Fri, 14 Aug 2026 08:12:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786695130; cv=none; b=bTkh+mBNlRlQQXhJHjyOScbNHH0vzSGQcXZ4Dfhhec9e2tyc96A8ApL/GUeNrdl4/thFbSTMJSplVtciMgthiF5G285wLEkExhuXjSohYXHbQR4nDivae9gyl6pTIi4wR579BSyaIkGVfBaBkoFxe/Rr+fsZkSW5RmoC+Q97Rug= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786695130; c=relaxed/simple; bh=9JYfE6tnahry8X0k+IgN6EW/bHkh7IZx52Pa3bkGtgE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GUNw/L4Fz3DPfcPPizQSQtEs/G9f9UoYNzZT02iJJhSoA+yVo+goHHM8MxHARxM0ez/y04P2UK5qN8IxT/9+QGr2z6KFeJ+Xsc/2/5pXT8ZxlEXdD8Xu25EXvfzJBXr1qDGDSofrrEHd8gUkngjt7q7TpJfnfiNNc/daP2g9x8Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 689C768B05; Fri, 14 Aug 2026 10:12:05 +0200 (CEST) Date: Fri, 14 Aug 2026 10:12:05 +0200 From: Christoph Hellwig To: Damien Le Moal Cc: Jens Axboe , linux-block@vger.kernel.org Subject: Re: [PATCH v4 13/13] block: flag zoned disks with GENHD_FL_NO_PART Message-ID: <20260814081205.GH12566@lst.de> References: <20260814063201.1762743-1-dlemoal@kernel.org> <20260814063201.1762743-14-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: linux-block@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: <20260814063201.1762743-14-dlemoal@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) On Fri, Aug 14, 2026 at 03:32:01PM +0900, Damien Le Moal wrote: > Zoned block devices do not support partitions. However, the partition > table is nevertheless still inspected, and any partition found ignored > with a warning in add_partition(). While this is generally not a problem, > and in fact beneficial to the user as it indicates an invalid use of a > zoned block device, scanning for a partition table on the device may > result in issuing read operations to offline zones (e.g. after a disk head > is depopulated for disks that support head management operations). > > Since partitions are ignored anyway, completely disable partition scanning > for zoned gendisks by setting the flag GENHD_FL_NO_PART in __add_disk(). > The existing check in add_partition() is left as-is to ensure that we > still get a warning if for whatever reason, despite GENHD_FL_NO_PART, we > still endup trying to add partitions. > > Flagging zoned disks with GENHD_FL_NO_PART also has the benefit to expose > through sysfs the ext_range attribute with the value of 1 instead of the > default DISK_MAX_PARTS, thus correctly advertizing the fact that zoned > disks do not support partitions. > > Signed-off-by: Damien Le Moal > Reviewed-by: Bart Van Assche > Reviewed-by: Hannes Reinecke This really should get a Fixes for my original patch that skipped partitions and go to -stable (and into 7.3 even if Jens won't take the whole series) as it causes totally pointless I/O. I also suspect the partition scanning and blkid interaction might be related to some of the weirdo xfstests failure I see where blkid doesn't detect xfs file systems in synthetic devices. Reviewed-by: Christoph Hellwig