At Sun, 11 Apr 2021 16:06:27 -0000 (UTC), mlel...@serpens.de (Michael van Elst) wrote: Subject: Re: I think I've found why Xen domUs can't mount some file-backed disk images! (vnd(4) hides labels!) > > k...@munnari.oz.au (Robert Elz) writes: > > > Date: Sun, 11 Apr 2021 14:25:40 -0000 (UTC) > > From: mlel...@serpens.de (Michael van Elst) > > Message-ID: <s4v0t4$5c8$1...@serpens.de> > > > | + dg->dg_secperunit = vnd->sc_size / DEV_BSIZE; > > >While it shouldn't make any difference for any properly created image > >file, make it be > > > (vnd->sc_size + DEV_BSIZE - 1) / DEV_BSIZE; > > >so that any trailing partial sector remains in the image. > > > The trailing partial sector is already ignored. Fortunately no disk image > can even have a partial trailing sector and some magically implicit > padding would have unexpected side effects. > > But the code also needs to be adjusted for different sector sizes.
So since vnd->sc_size is in units of disk blocks....
dg->dg_secperunit =
((vnd->sc_size * DEV_BSIZE) + DEV_BSIZE - 1) /
vnd->sc_geom.vng_secsize;
right?
--
Greg A. Woods <gwo...@acm.org>
Kelowna, BC +1 250 762-7675 RoboHack <wo...@robohack.ca>
Planix, Inc. <wo...@planix.com> Avoncote Farms <wo...@avoncote.ca>
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