Attachment 173357 Details for Bug 211361 – Proposed fix

[patch] Proposed fix

file_211361.txt (text/plain), 1.73 KB, created by Dag-Erling Smørgrav on 2016-08-06 14:23:31 UTC

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Creator: Dag-Erling Smørgrav

Created: 2016-08-06 14:23:31 UTC

Size: 1.73 KB

patch

obsolete

>Index: usr.sbin/bsdinstall/partedit/gpart_ops.c
>===================================================================
>--- usr.sbin/bsdinstall/partedit/gpart_ops.c	(revision 303770)
>+++ usr.sbin/bsdinstall/partedit/gpart_ops.c	(working copy)
>@@ -795,6 +795,7 @@
> {
> 	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 @@
> 
> 	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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Attachments on bug 211361: 173357