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To: Ming Lin <mlin@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
        Mike Snitzer <snitzer@redhat.com>, axboe@fb.com,
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Subject: Re: [PATCH v5 01/11] block: make generic_make_request handle arbitrarily sized bios
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Organization: Oracle Corporation
References: <CAF1ivSZbMDgyo_-wFGusSNSZ1fonSMWmNU9aVavGFaQsmEyYmQ@mail.gmail.com>
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Date: Mon, 10 Aug 2015 22:00:44 -0400
In-Reply-To: <1439230696.26458.6.camel@ssi> (Ming Lin's message of "Mon, 10
	Aug 2015 11:18:16 -0700")
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>>>>> "Ming" == Ming Lin <mlin@kernel.org> writes:

Ming> Did you mean still use (UINT_MAX >> 9) in blkdev_issue_discard()?

Ming> But that doesn't work for dm-thinp. See Kent's suggestion to use
Ming> 1<<31.

I'm not sure why things are not working for dm-thinp. Presumably Kent's
code would split the discard at a granularity boundary so why would that
cause problems for dm?

In looking at this I just found out that we'll corrupt data on certain
SCSI configs with the granularity enforcement in place. I'll have to
conjure up a fix for that...

-- 
Martin K. Petersen	Oracle Linux Engineering
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