Date: Mon, 15 Aug 2016 09:30:21 +0000 (UTC) From: =?UTF-8?Q?Dag-Erling_Sm=c3=b8rgrav?= <des@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304142 - head/usr.sbin/bsdinstall/partedit Message-ID: <201608150930.u7F9UL1V069576@repo.freebsd.org>
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Author: des Date: Mon Aug 15 09:30:21 2016 New Revision: 304142 URL: https://svnweb.freebsd.org/changeset/base/304142 Log: Ensure that the sector size is a multiple of 4096 to avoid creating unaligned partitions when the actual sector size is hidden from us. PR: 211361 MFC after: 3 days Modified: head/usr.sbin/bsdinstall/partedit/gpart_ops.c Modified: head/usr.sbin/bsdinstall/partedit/gpart_ops.c ============================================================================== --- head/usr.sbin/bsdinstall/partedit/gpart_ops.c Mon Aug 15 09:27:15 2016 (r304141) +++ head/usr.sbin/bsdinstall/partedit/gpart_ops.c Mon Aug 15 09:30:21 2016 (r304142) @@ -795,6 +795,7 @@ gpart_max_free(struct ggeom *geom, intma { struct gconfig *gc; struct gprovider *pp, **providers; + intmax_t sectorsize, stripesize, offset; intmax_t lastend; intmax_t start, end; intmax_t maxsize, maxstart; @@ -845,12 +846,25 @@ gpart_max_free(struct ggeom *geom, intma pp = LIST_FIRST(&geom->lg_consumer)->lg_provider; - /* Compute beginning of new partition and maximum available space */ - if (pp->lg_stripesize > 0 && - (maxstart*pp->lg_sectorsize % pp->lg_stripesize) != 0) { - intmax_t offset = (pp->lg_stripesize - - ((maxstart*pp->lg_sectorsize) % pp->lg_stripesize)) / - pp->lg_sectorsize; + /* + * Round the start and size of the largest available space up to + * the nearest multiple of the adjusted stripe size. + * + * The adjusted stripe size is the least common multiple of the + * actual stripe size, or the sector size if no stripe size was + * reported, and 4096. The reason for this is that contemporary + * disks often have 4096-byte physical sectors but report 512 + * bytes instead for compatibility with older / broken operating + * systems and BIOSes. For the same reasons, virtualized storage + * may also report a 512-byte stripe size, or none at all. + */ + sectorsize = pp->lg_sectorsize; + if ((stripesize = pp->lg_stripesize) == 0) + stripesize = sectorsize; + while (stripesize % 4096 != 0) + stripesize *= 2; + if ((offset = maxstart * sectorsize % stripesize) != 0) { + offset = (stripesize - offset) / sectorsize; maxstart += offset; maxsize -= offset; }
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