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Date: Fri, 13 Jun 2025 07:56:30 +0200
From: Christoph Hellwig <hch@lst.de>
To: Zhang Yi <yi.zhang@huaweicloud.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>, Christoph Hellwig <hch@lst.de>,
	linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
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	brauner@kernel.org, martin.petersen@oracle.com, yi.zhang@huawei.com,
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Subject: Re: [PATCH 01/10] block: introduce BLK_FEAT_WRITE_ZEROES_UNMAP to
 queue limits features
Message-ID: <20250613055630.GA9119@lst.de>
References: <20250604020850.1304633-1-yi.zhang@huaweicloud.com> <20250604020850.1304633-2-yi.zhang@huaweicloud.com> <20250611060900.GA4613@lst.de> <343f7f06-9bf6-442f-8e77-0a774203ec3f@huaweicloud.com> <20250612044744.GA12828@lst.de> <41c21e20-5439-4157-ad73-6f133df42d28@huaweicloud.com> <20250612150347.GK6138@frogsfrogsfrogs> <3569a77f-1f38-4764-b1e3-d0075775c7bb@huaweicloud.com>
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On Fri, Jun 13, 2025 at 11:15:41AM +0800, Zhang Yi wrote:
> Yeah, this solution looks good to me. However, we currently have only
> two selections (none and unmap). What if we keep it as is and simply
> hide this interface if BLK_FEAT_WRITE_ZEROES_UNMAP is not set, making
> it visible only when the device supports this feature? Something like
> below:

I really hate having all kinds of different interfaces for configurations.
Maybe we should redo this similar to the other hardware/software interfaces
and have a hw_ limit that is exposed by the driver and re-only in
sysfs, and then the user configurable one without _hw.  Setting it to
zero disables the feature.