Various fixes:

o  BSD disklabels have relative offsets. Even for the BSD in MBR slice
   setup, except when the mbroffset ioctl is supported. Since we don't
   support that ioctl, bsdlabel(8) expects relative offsets. So, when
   reading an existing disklabel, correct for disklabels that mistakenly
   have the mbroffset offsets.
o  Don't take the geometry seriously, because it's untrustworthy. We do
   expect the numbers to be within range. This means that the secperunit
   field will not be computed from secpercyl and ncyls, but simply is
   the mediasize in sectors.
o  Don't enforce partitions to be aligned to track boundaries. The
   default label, constructed by bsdlabel(8), puts partition a at offset
   BBSIZE bytes, which commonly means sector 16.

1 files changed, 25 insertions, 41 deletions

diff --git a/sys/geom/part/g_part_bsd.c b/sys/geom/part/g_part_bsd.c
index 474d16f..b7018c6 100644
--- a/sys/geom/part/g_part_bsd.c
+++ b/sys/geom/part/g_part_bsd.c
@@ -48,6 +48,7 @@ __FBSDID("$FreeBSD$");
 struct g_part_bsd_table {
 	struct g_part_table	base;
 	u_char			*label;
+	uint32_t		offset;
 };
 
 struct g_part_bsd_entry {
@@ -137,35 +138,15 @@ g_part_bsd_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
 {
 	struct g_part_bsd_entry *entry;
 	struct g_part_bsd_table *table;
-	uint32_t start, size, sectors;
 
 	if (gpp->gpp_parms & G_PART_PARM_LABEL)
 		return (EINVAL);
 
-	sectors = basetable->gpt_sectors;
-
 	entry = (struct g_part_bsd_entry *)baseentry;
 	table = (struct g_part_bsd_table *)basetable;
 
-	start = gpp->gpp_start;
-	size = gpp->gpp_size;
-	if (size < sectors)
-		return (EINVAL);
-	if (start % sectors) {
-		size = size - sectors + (start % sectors);
-		start = start - (start % sectors) + sectors;
-	}
-	if (size % sectors)
-		size = size - (size % sectors);
-	if (size < sectors)
-		return (EINVAL);
-
-	KASSERT(baseentry->gpe_start <= start, (__func__));
-	KASSERT(baseentry->gpe_end >= start + size - 1, (__func__));
-	baseentry->gpe_start = start;
-	baseentry->gpe_end = start + size - 1;
-	entry->part.p_size = size;
-	entry->part.p_offset = start + basetable->gpt_offset;
+	entry->part.p_size = gpp->gpp_size;
+	entry->part.p_offset = gpp->gpp_start + table->offset;
 	entry->part.p_fsize = 0;
 	entry->part.p_frag = 0;
 	entry->part.p_cpg = 0;
@@ -203,14 +184,14 @@ g_part_bsd_create(struct g_part_table *basetable, struct g_part_parms *gpp)
 	le32enc(ptr + 48, basetable->gpt_heads);	/* d_ntracks */
 	le32enc(ptr + 52, ncyls);			/* d_ncylinders */
 	le32enc(ptr + 56, secpercyl);			/* d_secpercyl */
-	le32enc(ptr + 60, ncyls * secpercyl);		/* d_secperunit */
+	le32enc(ptr + 60, msize);			/* d_secperunit */
 	le16enc(ptr + 72, 3600);			/* d_rpm */
 	le32enc(ptr + 132, DISKMAGIC);			/* d_magic2 */
 	le16enc(ptr + 138, basetable->gpt_entries);	/* d_npartitions */
 	le32enc(ptr + 140, BBSIZE);			/* d_bbsize */
 
 	basetable->gpt_first = 0;
-	basetable->gpt_last = ncyls * secpercyl - 1;
+	basetable->gpt_last = msize - 1;
 	basetable->gpt_isleaf = 1;
 
 	baseentry = g_part_new_entry(basetable, RAW_PART + 1,
@@ -218,7 +199,7 @@ g_part_bsd_create(struct g_part_table *basetable, struct g_part_parms *gpp)
 	baseentry->gpe_internal = 1;
 	entry = (struct g_part_bsd_entry *)baseentry;
 	entry->part.p_size = basetable->gpt_last + 1;
-	entry->part.p_offset = basetable->gpt_offset;
+	entry->part.p_offset = table->offset;
 
 	return (0);
 }
@@ -320,29 +301,31 @@ g_part_bsd_read(struct g_part_table *basetable, struct g_consumer *cp)
 	sectors = le32dec(buf + 44);
 	if (sectors < 1 || sectors > 63)
 		goto invalid_label;
-	if (sectors != basetable->gpt_sectors) {
-		if (basetable->gpt_fixgeom)
-			goto invalid_label;
+	if (sectors != basetable->gpt_sectors && !basetable->gpt_fixgeom) {
 		g_part_geometry_heads(msize, sectors, &chs, &heads);
-		if (chs == 0)
-			goto invalid_label;
-		basetable->gpt_sectors = sectors;
-		basetable->gpt_heads = heads;
+		if (chs != 0) {
+			basetable->gpt_sectors = sectors;
+			basetable->gpt_heads = heads;
+		}
 	}
 	heads = le32dec(buf + 48);
 	if (heads < 1 || heads > 255)
 		goto invalid_label;
-	if (heads != basetable->gpt_heads) {
-		if (basetable->gpt_fixgeom)
-			goto invalid_label;
+	if (heads != basetable->gpt_heads && !basetable->gpt_fixgeom)
 		basetable->gpt_heads = heads;
-	}
-	chs = le32dec(buf + 52) * heads * sectors;
+	if (sectors != basetable->gpt_sectors ||
+	    heads != basetable->gpt_heads)
+		printf("GEOM: %s: geometry does not match label.\n", pp->name);
+
+	chs = le32dec(buf + 60);
 	if (chs < 1 || chs > msize)
 		goto invalid_label;
+	if (chs != msize)
+		printf("GEOM: %s: media size does not match label.\n",
+		    pp->name);
 
 	basetable->gpt_first = 0;
-	basetable->gpt_last = chs - 1;
+	basetable->gpt_last = msize - 1;
 	basetable->gpt_isleaf = 1;
 
 	basetable->gpt_entries = le16dec(buf + 138);
@@ -350,6 +333,7 @@ g_part_bsd_read(struct g_part_table *basetable, struct g_consumer *cp)
 	    basetable->gpt_entries > g_part_bsd_scheme.gps_maxent)
 		goto invalid_label;
 
+	table->offset = le32dec(buf + 148 + RAW_PART * 16 + 4);
 	for (index = basetable->gpt_entries - 1; index >= 0; index--) {
 		p = buf + 148 + index * 16;
 		part.p_size = le32dec(p + 0);
@@ -362,11 +346,11 @@ g_part_bsd_read(struct g_part_table *basetable, struct g_consumer *cp)
 			continue;
 		if (part.p_fstype == FS_UNUSED && index != RAW_PART)
 			continue;
-		if (part.p_offset < basetable->gpt_offset)
+		if (part.p_offset < table->offset)
 			continue;
 		baseentry = g_part_new_entry(basetable, index + 1,
-		    part.p_offset - basetable->gpt_offset,
-		    part.p_offset - basetable->gpt_offset + part.p_size - 1);
+		    part.p_offset - table->offset,
+		    part.p_offset - table->offset + part.p_size - 1);
 		entry = (struct g_part_bsd_entry *)baseentry;
 		entry->part = part;
 		if (part.p_fstype == FS_UNUSED)