Add the EBR scheme. The EBR scheme supports the Extended Boot Records

found inside extended partitions and used to create logical partitions.
At this time write/modify support is not (yet) present.
The EBR and MBR schemes both check the parent scheme. The MBR will
back-off when nested under another MBR, whereas the EBR only nests
under a MBR.

4 files changed, 358 insertions, 0 deletions

diff --git a/sys/geom/part/g_part_ebr.c b/sys/geom/part/g_part_ebr.c
new file mode 100644
index 0000000..64534fe
--- /dev/null
+++ b/sys/geom/part/g_part_ebr.c
@@ -0,0 +1,339 @@
+/*-
+ * Copyright (c) 2007-2009 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bio.h>
+#include <sys/diskmbr.h>
+#include <sys/endian.h>
+#include <sys/kernel.h>
+#include <sys/kobj.h>
+#include <sys/limits.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/queue.h>
+#include <sys/sbuf.h>
+#include <sys/syscallsubr.h>
+#include <sys/systm.h>
+#include <geom/geom.h>
+#include <geom/part/g_part.h>
+
+#include "g_part_if.h"
+
+#define	EBRSIZE		512
+
+struct g_part_ebr_table {
+	struct g_part_table	base;
+};
+
+struct g_part_ebr_entry {
+	struct g_part_entry	base;
+	struct dos_partition	ent;
+};
+
+static int g_part_ebr_add(struct g_part_table *, struct g_part_entry *,
+    struct g_part_parms *);
+static int g_part_ebr_create(struct g_part_table *, struct g_part_parms *);
+static int g_part_ebr_destroy(struct g_part_table *, struct g_part_parms *);
+static void g_part_ebr_dumpconf(struct g_part_table *, struct g_part_entry *,
+    struct sbuf *, const char *);
+static int g_part_ebr_dumpto(struct g_part_table *, struct g_part_entry *);
+static int g_part_ebr_modify(struct g_part_table *, struct g_part_entry *,  
+    struct g_part_parms *);
+static const char *g_part_ebr_name(struct g_part_table *, struct g_part_entry *,
+    char *, size_t);
+static int g_part_ebr_probe(struct g_part_table *, struct g_consumer *);
+static int g_part_ebr_read(struct g_part_table *, struct g_consumer *);
+static int g_part_ebr_setunset(struct g_part_table *, struct g_part_entry *,
+    const char *, unsigned int);
+static const char *g_part_ebr_type(struct g_part_table *, struct g_part_entry *,
+    char *, size_t);
+static int g_part_ebr_write(struct g_part_table *, struct g_consumer *);
+
+static kobj_method_t g_part_ebr_methods[] = {
+	KOBJMETHOD(g_part_add,		g_part_ebr_add),
+	KOBJMETHOD(g_part_create,	g_part_ebr_create),
+	KOBJMETHOD(g_part_destroy,	g_part_ebr_destroy),
+	KOBJMETHOD(g_part_dumpconf,	g_part_ebr_dumpconf),
+	KOBJMETHOD(g_part_dumpto,	g_part_ebr_dumpto),
+	KOBJMETHOD(g_part_modify,	g_part_ebr_modify),
+	KOBJMETHOD(g_part_name,		g_part_ebr_name),
+	KOBJMETHOD(g_part_probe,	g_part_ebr_probe),
+	KOBJMETHOD(g_part_read,		g_part_ebr_read),
+	KOBJMETHOD(g_part_setunset,	g_part_ebr_setunset),
+	KOBJMETHOD(g_part_type,		g_part_ebr_type),
+	KOBJMETHOD(g_part_write,	g_part_ebr_write),
+	{ 0, 0 }
+};
+
+static struct g_part_scheme g_part_ebr_scheme = {
+	"EBR",
+	g_part_ebr_methods,
+	sizeof(struct g_part_ebr_table),
+	.gps_entrysz = sizeof(struct g_part_ebr_entry),
+	.gps_minent = 1,
+	.gps_maxent = INT_MAX,
+};
+G_PART_SCHEME_DECLARE(g_part_ebr);
+
+static void
+ebr_entry_decode(const char *p, struct dos_partition *ent)
+{
+	ent->dp_flag = p[0];
+	ent->dp_shd = p[1];
+	ent->dp_ssect = p[2];
+	ent->dp_scyl = p[3];
+	ent->dp_typ = p[4];
+	ent->dp_ehd = p[5];
+	ent->dp_esect = p[6];
+	ent->dp_ecyl = p[7];
+	ent->dp_start = le32dec(p + 8);
+	ent->dp_size = le32dec(p + 12);
+}
+
+static int
+g_part_ebr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
+    struct g_part_parms *gpp)
+{
+
+	return (ENOSYS);
+}
+
+static int
+g_part_ebr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
+{
+
+	return (ENOSYS);
+}
+
+static int
+g_part_ebr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
+{
+
+	/* Wipe the first sector to clear the partitioning. */
+	basetable->gpt_smhead |= 1;
+	return (0);
+}
+
+static void
+g_part_ebr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 
+    struct sbuf *sb, const char *indent)
+{
+	struct g_part_ebr_entry *entry;
+ 
+	entry = (struct g_part_ebr_entry *)baseentry;
+	if (indent == NULL) {
+		/* conftxt: libdisk compatibility */
+		sbuf_printf(sb, " xs MBREXT xt %u", entry->ent.dp_typ);
+	} else if (entry != NULL) {
+		/* confxml: partition entry information */
+		sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
+		    entry->ent.dp_typ);
+		if (entry->ent.dp_flag & 0x80)
+			sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
+	} else {
+		/* confxml: scheme information */
+	}
+}
+
+static int
+g_part_ebr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)  
+{
+	struct g_part_ebr_entry *entry;
+
+	/* Allow dumping to a FreeBSD partition only. */
+	entry = (struct g_part_ebr_entry *)baseentry;
+	return ((entry->ent.dp_typ == DOSPTYP_386BSD) ? 1 : 0);
+}
+
+static int
+g_part_ebr_modify(struct g_part_table *basetable,
+    struct g_part_entry *baseentry, struct g_part_parms *gpp)
+{
+
+	return (ENOSYS);
+}
+
+static const char *
+g_part_ebr_name(struct g_part_table *table, struct g_part_entry *entry,
+    char *buf, size_t bufsz)
+{
+
+	snprintf(buf, bufsz, ".%08u", entry->gpe_index);
+	return (buf);
+}
+
+static int
+g_part_ebr_probe(struct g_part_table *table, struct g_consumer *cp)
+{
+	char psn[8];
+	struct g_provider *pp;
+	u_char *buf, *p;
+	int error, index, res, sum;
+	uint16_t magic;
+
+	pp = cp->provider;
+
+	/* Sanity-check the provider. */
+	if (pp->sectorsize < EBRSIZE || pp->mediasize < pp->sectorsize)
+		return (ENOSPC);
+	if (pp->sectorsize > 4096)
+		return (ENXIO);
+
+	/* Check that we have a parent and that it's a MBR. */
+	if (table->gpt_depth == 0)
+		return (ENXIO);
+	error = g_getattr("PART::scheme", cp, &psn);
+	if (error)
+		return (error);
+	if (strcmp(psn, "MBR"))
+		return (ENXIO);
+
+	/* Check that there's a EBR. */
+	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
+	if (buf == NULL)
+		return (error);
+
+	/* We goto out on mismatch. */
+	res = ENXIO;
+
+	magic = le16dec(buf + DOSMAGICOFFSET);
+	if (magic != DOSMAGIC)
+		goto out;
+
+	/* The sector is all zeroes, except for the partition entries. */
+	sum = 0;
+	for (index = 0; index < DOSPARTOFF; index++)
+		sum += buf[index];
+	if (sum != 0)
+		goto out;
+
+	for (index = 0; index < NDOSPART; index++) {
+		p = buf + DOSPARTOFF + index * DOSPARTSIZE;
+		if (p[0] != 0 && p[0] != 0x80)
+			goto out;
+		if (index < 2)
+			continue;
+		/* The 3rd & 4th entries are always zero. */
+		if ((le64dec(p+0) + le64dec(p+8)) != 0)
+			goto out;
+	}
+
+	res = G_PART_PROBE_PRI_HIGH;
+
+ out:
+	g_free(buf);
+	return (res);
+}
+
+static int
+g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
+{
+	struct dos_partition ent[2];
+	struct g_provider *pp;
+	struct g_part_entry *baseentry;
+	struct g_part_ebr_table *table;
+	struct g_part_ebr_entry *entry;
+	u_char *buf;
+	off_t ofs, msize;
+	u_int lba;
+	int error, index;
+
+	pp = cp->provider;
+	table = (struct g_part_ebr_table *)basetable;
+	msize = pp->mediasize / pp->sectorsize;
+
+	lba = 0;
+	while (1) {
+		ofs = (off_t)lba * pp->sectorsize;
+		buf = g_read_data(cp, ofs, pp->sectorsize, &error);
+		if (buf == NULL)
+			return (error);
+
+		ebr_entry_decode(buf + DOSPARTOFF + 0 * DOSPARTSIZE, ent + 0);
+		ebr_entry_decode(buf + DOSPARTOFF + 1 * DOSPARTSIZE, ent + 1);
+		g_free(buf);
+
+		if (ent[0].dp_typ == 0)
+			break;
+
+		if (ent[0].dp_typ == 5 && ent[1].dp_typ == 0) {
+			lba = ent[0].dp_start;
+			continue;
+		}
+
+		index = (lba / basetable->gpt_sectors) + 1;
+		baseentry = (struct g_part_entry *)g_part_new_entry(basetable,
+		    index, lba, lba + ent[0].dp_start + ent[0].dp_size - 1);
+		baseentry->gpe_offset = (off_t)(lba + ent[0].dp_start) *
+		    pp->sectorsize;
+		entry = (struct g_part_ebr_entry *)baseentry;
+		entry->ent = ent[0];
+
+		if (ent[1].dp_typ == 0)
+			break;
+
+		lba = ent[1].dp_start;
+	}
+
+	basetable->gpt_entries = msize / basetable->gpt_sectors;
+	basetable->gpt_first = 0;
+	basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1;
+	return (0);
+}
+
+static int
+g_part_ebr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
+    const char *attrib, unsigned int set)
+{
+
+	return (ENOSYS);
+}
+
+static const char *
+g_part_ebr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 
+    char *buf, size_t bufsz)
+{
+	struct g_part_ebr_entry *entry;
+	int type;
+
+	entry = (struct g_part_ebr_entry *)baseentry;
+	type = entry->ent.dp_typ;
+	if (type == DOSPTYP_386BSD)
+		return (g_part_alias_name(G_PART_ALIAS_FREEBSD));
+	snprintf(buf, bufsz, "!%d", type);
+	return (buf);
+}
+
+static int
+g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
+{
+
+	return (ENOSYS);
+}
diff --git a/sys/geom/part/g_part_mbr.c b/sys/geom/part/g_part_mbr.c
index 19341ff..e058b05 100644
--- a/sys/geom/part/g_part_mbr.c
+++ b/sys/geom/part/g_part_mbr.c
@@ -314,6 +314,7 @@ g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry,
 static int
 g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
 {
+	char psn[8];
 	struct g_provider *pp;
 	u_char *buf, *p;
 	int error, index, res, sum;
@@ -327,6 +328,11 @@ g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
 	if (pp->sectorsize > 4096)
 		return (ENXIO);
 
+	/* We don't nest under an MBR (see EBR instead). */
+	error = g_getattr("PART::scheme", cp, &psn);
+	if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0)
+		return (ELOOP);
+
 	/* Check that there's a MBR. */
 	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
 	if (buf == NULL)
diff --git a/sys/modules/geom/geom_part/Makefile b/sys/modules/geom/geom_part/Makefile
index 63a4374..898eccc 100644
--- a/sys/modules/geom/geom_part/Makefile
+++ b/sys/modules/geom/geom_part/Makefile
@@ -2,6 +2,7 @@
 
 SUBDIR=	geom_part_apm \
 	geom_part_bsd \
+	geom_part_ebr \
 	geom_part_gpt \
 	geom_part_mbr \
 	geom_part_pc98 \
diff --git a/sys/modules/geom/geom_part/geom_part_ebr/Makefile b/sys/modules/geom/geom_part/geom_part_ebr/Makefile
new file mode 100644
index 0000000..4b773e6
--- /dev/null
+++ b/sys/modules/geom/geom_part/geom_part_ebr/Makefile
@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../../../geom/part
+
+KMOD=	geom_part_ebr
+SRCS=	g_part_ebr.c
+
+SRCS+=	bus_if.h device_if.h g_part_if.h
+
+MFILES=	kern/bus_if.m kern/device_if.m geom/part/g_part_if.m
+
+.include <bsd.kmod.mk>