Messages in this thread |  | | Subject | Re: [PATCH 3/4] loop: Add 'lo_logical_blocksize' | From | Hannes Reinecke <> | Date | Tue, 1 Nov 2016 17:57:08 +0100 |
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On 11/01/2016 03:01 PM, Christoph Hellwig wrote: > On Mon, Oct 31, 2016 at 08:37:18PM +0100, Hannes Reinecke wrote: >> Add a new field 'lo_logical_blocksize' to hold the logical >> blocksize of the loop device. > > Why do we use the same flag for both block sizes? If there is a good > reason for that it should be documented and both should be in the same > patch. > _Actually_ the flag enables you to set the logical blocksize. However, if you want to set the logical blocksize you also have to set a matching physical blocksize. And the physical blocksize itself isn't settable, rather taken from the underlying device/filesystem/whatever. So the flag itself does not have a dual purpose, it's just out of necessity that you have to set the physical blocksize if you want to change the logical blocksize.
And I got pushback when I proposed to set the physical blocksize always, so I made it dependent on the LO_BLOCKSIZE flag, too.
Cheers,
Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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