From: Eric Sandeen <sandeen@sandeen.net>
Date: Wed, 29 Jul 2015 23:17:43 +0000 (+1000)
Subject: metadump: Add option to copy metadata blocks intact
X-Git-Tag: v3.2.4~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b09e839e3637203c16a9793d93cde78307f13d7b;p=thirdparty%2Fxfsprogs-dev.git

metadump: Add option to copy metadata blocks intact

By default we zero out unused portions of metadata blocks.
This adds an option to keep blocks intact, to better investigate
corruptions.

Nothing in this patch reads it, but subsequent patches add
users of the option.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
---

diff --git a/db/metadump.c b/db/metadump.c
index dd1d7ab9d..67d254567 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -57,7 +57,7 @@ static void	metadump_help(void);
 
 static const cmdinfo_t	metadump_cmd =
 	{ "metadump", NULL, metadump_f, 0, -1, 0,
-		N_("[-e] [-g] [-m max_extent] [-w] [-o] filename"),
+		N_("[-a] [-e] [-g] [-m max_extent] [-w] [-o] filename"),
 		N_("dump metadata to a file"), metadump_help };
 
 static FILE		*outf;		/* metadump file */
@@ -75,6 +75,7 @@ static int		show_progress = 0;
 static int		stop_on_read_error = 0;
 static int		max_extent_size = DEFAULT_MAX_EXT_SIZE;
 static int		obfuscate = 1;
+static int		zero_stale_data = 1;
 static int		show_warnings = 0;
 static int		progress_since_warning = 0;
 
@@ -93,6 +94,7 @@ metadump_help(void)
 " for compressing and sending to an XFS maintainer for corruption analysis \n"
 " or xfs_repair failures.\n\n"
 " Options:\n"
+"   -a -- Copy full metadata blocks without zeroing unused space\n"
 "   -e -- Ignore read errors and keep going\n"
 "   -g -- Display dump progress\n"
 "   -m -- Specify max extent size in blocks to copy (default = %d blocks)\n"
@@ -2256,8 +2258,11 @@ metadump_f(
 		return 0;
 	}
 
-	while ((c = getopt(argc, argv, "egm:ow")) != EOF) {
+	while ((c = getopt(argc, argv, "aegm:ow")) != EOF) {
 		switch (c) {
+			case 'a':
+				zero_stale_data = 0;
+				break;
 			case 'e':
 				stop_on_read_error = 1;
 				break;
diff --git a/db/xfs_metadump.sh b/db/xfs_metadump.sh
index a95d5a561..836d3aecf 100755
--- a/db/xfs_metadump.sh
+++ b/db/xfs_metadump.sh
@@ -5,11 +5,12 @@
 
 OPTS=" "
 DBOPTS=" "
-USAGE="Usage: xfs_metadump [-efFogwV] [-m max_extents] [-l logdev] source target"
+USAGE="Usage: xfs_metadump [-aefFogwV] [-m max_extents] [-l logdev] source target"
 
-while getopts "efgl:m:owFV" c
+while getopts "aefgl:m:owFV" c
 do
 	case $c in
+	a)	OPTS=$OPTS"-a ";;
 	e)	OPTS=$OPTS"-e ";;
 	g)	OPTS=$OPTS"-g ";;
 	m)	OPTS=$OPTS"-m "$OPTARG" ";;
diff --git a/man/man8/xfs_metadump.8 b/man/man8/xfs_metadump.8
index 077fff5f7..81a17a960 100644
--- a/man/man8/xfs_metadump.8
+++ b/man/man8/xfs_metadump.8
@@ -4,7 +4,7 @@ xfs_metadump \- copy XFS filesystem metadata to a file
 .SH SYNOPSIS
 .B xfs_metadump
 [
-.B \-efFgow
+.B \-aefFgow
 ] [
 .B \-m
 .I max_extents
@@ -74,6 +74,14 @@ tool.
 .PP
 .SH OPTIONS
 .TP
+.B \-a
+Copies entire metadata blocks.  Normally,
+.B xfs_metadump
+will zero any stale
+bytes interspersed with in-use metadata.  Use this option to copy full metadata
+blocks, to provide more debugging information for a corrupted filesystem.  Note
+that the extra data will be unobfuscated.
+.TP
 .B \-e
 Stops the dump on a read error. Normally, it will ignore read errors and copy
 all the metadata that is accessible.