From c9e4a61574ac5113ed58751c96920a81bff39c67 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 21 Sep 2009 15:32:09 +0200
Subject: [PATCH] libblkid: add EVMS topology support (for old kernels)

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 shlibs/blkid/src/topology/Makefile.am |  3 +-
 shlibs/blkid/src/topology/evms.c      | 73 +++++++++++++++++++++++++++
 shlibs/blkid/src/topology/topology.c  |  3 +-
 shlibs/blkid/src/topology/topology.h  |  1 +
 4 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 shlibs/blkid/src/topology/evms.c

diff --git a/shlibs/blkid/src/topology/Makefile.am b/shlibs/blkid/src/topology/Makefile.am
index 06927b28..ffaf58dc 100644
--- a/shlibs/blkid/src/topology/Makefile.am
+++ b/shlibs/blkid/src/topology/Makefile.am
@@ -8,4 +8,5 @@ libblkid_topology_la_SOURCES =	topology.c \
 				topology.h \
 				sysfs.c \
 				md.c \
-				dm.c
+				dm.c \
+				evms.c
diff --git a/shlibs/blkid/src/topology/evms.c b/shlibs/blkid/src/topology/evms.c
new file mode 100644
index 00000000..9f6c48df
--- /dev/null
+++ b/shlibs/blkid/src/topology/evms.c
@@ -0,0 +1,73 @@
+/*
+ * Evms topology
+ * -- this is fallback for old systems where the toplogy information are not
+ *    exporte dy sysfs
+ *
+ * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ *
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "topology.h"
+
+#define EVMS_MAJOR		117
+#define EVMS_GET_STRIPE_INFO	_IOR(EVMS_MAJOR, 0xF0, struct evms_stripe_info)
+
+struct evms_stripe_info {
+	u_int32_t	size;		/* stripe unit 512-byte blocks */
+	u_int32_t	width;		/* the number of stripe members or RAID data disks */
+} evms_stripe_info;
+
+static int is_evms_device(dev_t devno)
+{
+	if (major(devno) == EVMS_MAJOR)
+		return 1;
+	if (blkid_driver_has_major("evms", major(devno)))
+		return 1;
+	return 0;
+}
+
+static int probe_evms_tp(blkid_probe pr, const struct blkid_idmag *mag)
+{
+	struct evms_stripe_info evms;
+	dev_t devno = blkid_probe_get_devno(pr);
+
+	if (!devno)
+		goto nothing;		/* probably not a block device */
+
+	if (!is_evms_device(devno))
+		goto nothing;
+
+	memset(&evms, 0, sizeof(evms));
+
+	if (ioctl(pr->fd, EVMS_GET_STRIPE_INFO, &evms))
+		goto nothing;
+
+	blkid_topology_set_minimum_io_size(pr, evms.size << 9);
+	blkid_topology_set_optimal_io_size(pr, (evms.size * evms.width) << 9);
+
+	return 0;
+
+nothing:
+	return 1;
+}
+
+const struct blkid_idinfo evms_tp_idinfo =
+{
+	.name		= "evms",
+	.probefunc	= probe_evms_tp,
+	.magics		= BLKID_NONE_MAGIC
+};
+
diff --git a/shlibs/blkid/src/topology/topology.c b/shlibs/blkid/src/topology/topology.c
index d6132a8f..ab2ecd0d 100644
--- a/shlibs/blkid/src/topology/topology.c
+++ b/shlibs/blkid/src/topology/topology.c
@@ -61,7 +61,8 @@ static const struct blkid_idinfo *idinfos[] =
 {
 	&sysfs_tp_idinfo,
 	&md_tp_idinfo,
-	&dm_tp_idinfo
+	&dm_tp_idinfo,
+	&evms_tp_idinfo
 };
 
 
diff --git a/shlibs/blkid/src/topology/topology.h b/shlibs/blkid/src/topology/topology.h
index 8cfcaf98..48d3f26f 100644
--- a/shlibs/blkid/src/topology/topology.h
+++ b/shlibs/blkid/src/topology/topology.h
@@ -13,6 +13,7 @@ extern int blkid_topology_set_optimal_io_size(blkid_probe pr, unsigned long val)
 extern const struct blkid_idinfo sysfs_tp_idinfo;
 extern const struct blkid_idinfo md_tp_idinfo;
 extern const struct blkid_idinfo dm_tp_idinfo;
+extern const struct blkid_idinfo evms_tp_idinfo;
 
 #endif /* BLKID_TOPOLOGY_H */
 
-- 
2.39.5