From b4ebb02af54257d582b9e9d823dbaab5bad63fb7 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Tue, 5 Jan 2010 13:25:12 +0000
Subject: [PATCH] For completeness, add -s argument, manually specifying array
 block size.

---
 sbin/geom/class/raid3/geom_raid3.c | 7 +++++--
 sbin/geom/class/raid3/graid3.8     | 9 ++++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/sbin/geom/class/raid3/geom_raid3.c b/sbin/geom/class/raid3/geom_raid3.c
index 4a2dbe201ef2..89ce1689ba83 100644
--- a/sbin/geom/class/raid3/geom_raid3.c
+++ b/sbin/geom/class/raid3/geom_raid3.c
@@ -45,6 +45,8 @@ __FBSDID("$FreeBSD$");
 uint32_t lib_version = G_LIB_VERSION;
 uint32_t version = G_RAID3_VERSION;
 
+static intmax_t default_blocksize = 0;
+
 static void raid3_main(struct gctl_req *req, unsigned f);
 static void raid3_clear(struct gctl_req *req);
 static void raid3_dump(struct gctl_req *req);
@@ -87,10 +89,11 @@ struct g_command class_commands[] = {
 		{ 'F', "nofailsync", NULL, G_TYPE_BOOL },
 		{ 'n', "noautosync", NULL, G_TYPE_BOOL },
 		{ 'r', "round_robin", NULL, G_TYPE_BOOL },
+		{ 's', "blocksize", &default_blocksize, G_TYPE_NUMBER },
 		{ 'w', "verify", NULL, G_TYPE_BOOL },
 		G_OPT_SENTINEL
 	    },
-	    NULL, "[-hFnrvw] name prov prov prov ..."
+	    NULL, "[-hFnrvw] [-s blocksize] name prov prov prov ..."
 	},
 	{ "rebuild", G_FLAG_VERBOSE, NULL, G_NULL_OPTS, NULL,
 	    "[-v] name prov"
@@ -190,7 +193,7 @@ raid3_label(struct gctl_req *req)
 	 * sectorsizes of every disk and find the smallest mediasize.
 	 */
 	mediasize = 0;
-	sectorsize = 0;
+	sectorsize = gctl_get_intmax(req, "blocksize");
 	for (i = 1; i < nargs; i++) {
 		str = gctl_get_ascii(req, "arg%d", i);
 		msize = g_get_mediasize(str);
diff --git a/sbin/geom/class/raid3/graid3.8 b/sbin/geom/class/raid3/graid3.8
index 21c6f181e773..f9ea0cace592 100644
--- a/sbin/geom/class/raid3/graid3.8
+++ b/sbin/geom/class/raid3/graid3.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 1, 2006
+.Dd January 5, 2010
 .Dt GRAID3 8
 .Os
 .Sh NAME
@@ -34,6 +34,7 @@
 .Nm
 .Cm label
 .Op Fl Fhnrvw
+.Op Fl s Ar blocksize
 .Ar name
 .Ar prov prov prov ...
 .Nm
@@ -113,6 +114,12 @@ but sequential reads are slower.
 One cannot use this option if the
 .Fl w
 option is also specified.
+.It Fl s
+Manually specify array block size. Block size will be set equal to least
+common multiple of all component's sector sizes and specified value.
+Note that array sector size calculated as multiple of block size and number
+of regular data components. Big values may decrease performance and compatibility,
+as all I/O requests have to be multiple of sector size.
 .It Fl w
 Use verify reading feature.
 When reading from a device in a complete state, also read data from the parity component