From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH 1/1] sd: fix lbprz discard granularity as expected
Date: Mon, 14 Mar 2016 16:07:19 -0400
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	(Tom Yan's message of "Sat, 12 Mar 2016 13:43:02 +0800")
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To: Tom Yan <tom.ty89@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>, linux-scsi@vger.kernel.org

>>>>> "Tom" == Tom Yan <tom.ty89@gmail.com> writes:

Tom,

Tom> But yeah if it has unmap granularity reported to be, for example,
Tom> 16, then it will not be correctly set with min_not_zero().

Tom> Wait, shouldn't it be:

Tom> max(sdkp->logical_block_size, sdkp->unmap_granularity * logical_block_size);

Tom> then?

Let's take the your example of a drive with 512-byte logical blocks and
4096-byte physical blocks. How would a drive partially unmap a sector?

-- 
Martin K. Petersen	Oracle Linux Engineering