From: Eric Sandeen <sandeen@sgi.com>
Date: Mon, 3 May 2004 22:35:41 +0000 (+0000)
Subject: zero more at end of device at mkfs time, be sure to
X-Git-Tag: v2.7.0~103
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c617c87b784f94da0df75235df7a86e3d14d0f0;p=thirdparty%2Fxfsprogs-dev.git

zero more at end of device at mkfs time, be sure to
get any old md superblock (which throws off mount-by-label)
bump version
---

diff --git a/VERSION b/VERSION
index 80f357450..92b207540 100644
--- a/VERSION
+++ b/VERSION
@@ -3,5 +3,5 @@
 #
 PKG_MAJOR=2
 PKG_MINOR=6
-PKG_REVISION=12
+PKG_REVISION=13
 PKG_BUILD=1
diff --git a/doc/CHANGES b/doc/CHANGES
index ca91e93db..72383c687 100644
--- a/doc/CHANGES
+++ b/doc/CHANGES
@@ -1,3 +1,7 @@
+xfsprogs-2.6.13 (03 May 2004)
+	- zero out more at beginning and end of device at mkfs time
+	  (get all old MD superblocks at the end, for mount by label).
+
 xfsprogs-2.6.12 (30 April 2004)
 	- Extract stripe unit/width from device mapper devices
 	  (added libdisk infrastructure, used by mkfs.xfs).
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 61c1f65bc..10ca6ebcf 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -185,6 +185,11 @@ char	*sopts[] = {
 	((uint)(MKFS_BLOCKRES_INODE + XFS_DA_NODE_MAXDEPTH + \
 	(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) - 1) + (rb)))
 
+/* amount (in bytes) we zero at the beginning and end of the device to
+ * remove traces of other filesystems, raid superblocks, etc.
+ */
+#define WHACK_SIZE (128 * 1024)
+
 static void
 calc_stripe_factors(
 	int		dsu,
@@ -1934,13 +1939,13 @@ an AG size that is one stripe unit smaller, for example %llu.\n"),
 			(sectorsize != BBSIZE || lsectorsize != BBSIZE), 0);
 	sbp->sb_features2 = XFS_SB_VERSION2_MKFS(0);
 	/*
-	 * Zero out the first 68k in on the device, to obliterate any old 
+	 * Zero out the beginning of the device, to obliterate any old 
 	 * filesystem signatures out there.  This should take care of 
 	 * swap (somewhere around the page size), jfs (32k), 
 	 * ext[2,3] and reiserfs (64k) - and hopefully all else.
 	 */
-	buf = libxfs_getbuf(xi.ddev, 0, 136);
-	bzero(XFS_BUF_PTR(buf), 136*BBSIZE);
+	buf = libxfs_getbuf(xi.ddev, 0, BTOBB(WHACK_SIZE));
+	bzero(XFS_BUF_PTR(buf), WHACK_SIZE);
 	libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
 
 	/* OK, now write the superblock */
@@ -1962,13 +1967,14 @@ an AG size that is one stripe unit smaller, for example %llu.\n"),
 	}
 
 	/*
-	 * Zero out the last 64k on the device, to obliterate any
+	 * Zero out the end of the device, to obliterate any
 	 * old MD RAID (or other) metadata at the end of the device.
+ 	 * (MD sb is ~64k from the end, take out a wider swath to be sure)
 	 */
 	if (!xi.disfile) {
-		buf = libxfs_getbuf(xi.ddev, (xi.dsize - BTOBB(65536)), 
-				    BTOBB(65536));
-		bzero(XFS_BUF_PTR(buf), 65536);
+		buf = libxfs_getbuf(xi.ddev, (xi.dsize - BTOBB(WHACK_SIZE)), 
+				    BTOBB(WHACK_SIZE));
+		bzero(XFS_BUF_PTR(buf), WHACK_SIZE);
 		libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
 	}