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Date: Mon, 4 Nov 2024 08:47:06 +0100
From: Christoph Hellwig <hch@lst.de>
To: John Garry <john.g.garry@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>, axboe@kernel.dk,
	linux-block@vger.kernel.org
Subject: Re: [PATCH] loop: Use bdev limit helpers for configuring discard
Message-ID: <20241104074706.GA20887@lst.de>
References: <20241030111900.3981223-1-john.g.garry@oracle.com> <20241030140601.GA29107@lst.de> <27a2e5e7-9dbc-4fa6-81c2-1a8df906187b@oracle.com> <629883c0-9269-4820-801c-a5ed6e4b2803@oracle.com>
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On Fri, Nov 01, 2024 at 09:08:51AM +0000, John Garry wrote:
>> ok, I see that set in blk_validate_limits()
>
> BTW, can the check for granularity ever fail in 
> queue_limit_discard_alignment()
>
> static unsigned int queue_limit_discard_alignment(...)
> {
> 	...
>
> 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
> 	if (!granularity)
> 		return 0;

lim->discard_granularity is always set to SECTOR_SIZE or large,
so granularity can't be 0 here.