[PATCH V2 13/23] metadump: Add support for passing version option

From: Chandan Babu R <chandan.babu@oracle.com>
To: linux-xfs@vger.kernel.org
Cc: Chandan Babu R <chandan.babu@oracle.com>,
	djwong@kernel.org, cem@kernel.org
Subject: [PATCH V2 13/23] metadump: Add support for passing version option
Date: Tue,  6 Jun 2023 14:57:56 +0530	[thread overview]
Message-ID: <20230606092806.1604491-14-chandan.babu@oracle.com> (raw)
In-Reply-To: <20230606092806.1604491-1-chandan.babu@oracle.com>

The new option allows the user to explicitly specify the version of metadump
to use. However, we will default to using the v1 format.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 db/io.h                 |  2 ++
 db/metadump.c           | 53 ++++++++++++++++++++++++++++++++++-------
 db/xfs_metadump.sh      |  3 ++-
 man/man8/xfs_metadump.8 | 14 +++++++++++
 4 files changed, 62 insertions(+), 10 deletions(-)

diff --git a/db/io.h b/db/io.h
index c29a7488..bd86c31f 100644
--- a/db/io.h
+++ b/db/io.h
@@ -49,6 +49,8 @@ extern void	push_cur_and_set_type(void);
 extern void	write_cur(void);
 extern void	set_cur(const struct typ *type, xfs_daddr_t blknum,
 			int len, int ring_add, bbmap_t *bbmap);
+extern void	set_log_cur(const struct typ *type, xfs_daddr_t blknum,
+			int len, int ring_add, bbmap_t *bbmap);
 extern void     ring_add(void);
 extern void	set_iocur_type(const struct typ *type);
 extern void	xfs_dummy_verify(struct xfs_buf *bp);
diff --git a/db/metadump.c b/db/metadump.c
index 537c37f7..a9b27e95 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -37,7 +37,7 @@ static void	metadump_help(void);
 
 static const cmdinfo_t	metadump_cmd =
 	{ "metadump", NULL, metadump_f, 0, -1, 0,
-		N_("[-a] [-e] [-g] [-m max_extent] [-w] [-o] filename"),
+		N_("[-a] [-e] [-g] [-m max_extent] [-w] [-o] [-v 1|2] filename"),
 		N_("dump metadata to a file"), metadump_help };
 
 struct metadump_ops {
@@ -74,6 +74,7 @@ static struct metadump {
 	bool			zero_stale_data;
 	bool			progress_since_warning;
 	bool			dirty_log;
+	bool			external_log;
 	bool			stdout_metadump;
 	xfs_ino_t		cur_ino;
 	/* Metadump file */
@@ -107,6 +108,7 @@ metadump_help(void)
 "   -g -- Display dump progress\n"
 "   -m -- Specify max extent size in blocks to copy (default = %d blocks)\n"
 "   -o -- Don't obfuscate names and extended attributes\n"
+"   -v -- Metadump version to be used\n"
 "   -w -- Show warnings of bad metadata information\n"
 "\n"), DEFAULT_MAX_EXT_SIZE);
 }
@@ -2907,8 +2909,9 @@ copy_log(void)
 		print_progress("Copying log");
 
 	push_cur();
-	set_cur(&typtab[TYP_LOG], XFS_FSB_TO_DADDR(mp, mp->m_sb.sb_logstart),
-			mp->m_sb.sb_logblocks * blkbb, DB_RING_IGN, NULL);
+	set_log_cur(&typtab[TYP_LOG],
+		XFS_FSB_TO_DADDR(mp, mp->m_sb.sb_logstart),
+		mp->m_sb.sb_logblocks * blkbb, DB_RING_IGN, NULL);
 	if (iocur_top->data == NULL) {
 		pop_cur();
 		print_warning("cannot read log");
@@ -3069,6 +3072,8 @@ init_metadump_v2(void)
 		compat_flags |= XFS_MD2_INCOMPAT_FULLBLOCKS;
 	if (metadump.dirty_log)
 		compat_flags |= XFS_MD2_INCOMPAT_DIRTYLOG;
+	if (metadump.external_log)
+		compat_flags |= XFS_MD2_INCOMPAT_EXTERNALLOG;
 
 	xmh.xmh_compat_flags = cpu_to_be32(compat_flags);
 
@@ -3129,6 +3134,7 @@ metadump_f(
 	int		outfd = -1;
 	int		ret;
 	char		*p;
+	bool		version_opt_set = false;
 
 	exitcode = 1;
 
@@ -3140,6 +3146,7 @@ metadump_f(
 	metadump.obfuscate = true;
 	metadump.zero_stale_data = true;
 	metadump.dirty_log = false;
+	metadump.external_log = false;
 
 	if (mp->m_sb.sb_magicnum != XFS_SB_MAGIC) {
 		print_warning("bad superblock magic number %x, giving up",
@@ -3157,7 +3164,7 @@ metadump_f(
 		return 0;
 	}
 
-	while ((c = getopt(argc, argv, "aegm:ow")) != EOF) {
+	while ((c = getopt(argc, argv, "aegm:ov:w")) != EOF) {
 		switch (c) {
 			case 'a':
 				metadump.zero_stale_data = false;
@@ -3181,6 +3188,17 @@ metadump_f(
 			case 'o':
 				metadump.obfuscate = false;
 				break;
+			case 'v':
+				metadump.version = (int)strtol(optarg, &p, 0);
+				if (*p != '\0' ||
+					(metadump.version != 1 &&
+						metadump.version != 2)) {
+					print_warning("bad metadump version: %s",
+						optarg);
+					return 0;
+				}
+				version_opt_set = true;
+				break;
 			case 'w':
 				metadump.show_warnings = true;
 				break;
@@ -3195,10 +3213,27 @@ metadump_f(
 		return 0;
 	}
 
-	/* If we'll copy the log, see if the log is dirty */
-	if (mp->m_sb.sb_logstart) {
+	if (mp->m_logdev_targp->bt_bdev != mp->m_ddev_targp->bt_bdev)
+		metadump.external_log = true;
+
+	if (metadump.external_log && !version_opt_set)
+		metadump.version = 2;
+
+	if (metadump.version == 2 && mp->m_sb.sb_logstart == 0 &&
+		!metadump.external_log) {
+		print_warning("external log device not loaded, use -l");
+		return -ENODEV;
+	}
+
+	/*
+	 * If we'll copy the log, see if the log is dirty.
+	 *
+	 * Metadump v1 does not support dumping the contents of an external
+	 * log. Hence we skip the dirty log check.
+	 */
+	if (!(metadump.version == 1 && metadump.external_log)) {
 		push_cur();
-		set_cur(&typtab[TYP_LOG],
+		set_log_cur(&typtab[TYP_LOG],
 			XFS_FSB_TO_DADDR(mp, mp->m_sb.sb_logstart),
 			mp->m_sb.sb_logblocks * blkbb, DB_RING_IGN, NULL);
 		if (iocur_top->data) {	/* best effort */
@@ -3276,8 +3311,8 @@ metadump_f(
 	if (!exitcode)
 		exitcode = !copy_sb_inodes();
 
-	/* copy log if it's internal */
-	if ((mp->m_sb.sb_logstart != 0) && !exitcode)
+	/* copy log */
+	if (!exitcode && !(metadump.version == 1 && metadump.external_log))
 		exitcode = !copy_log();
 
 	/* write the remaining index */
diff --git a/db/xfs_metadump.sh b/db/xfs_metadump.sh
index 9852a5bc..9e8f86e5 100755
--- a/db/xfs_metadump.sh
+++ b/db/xfs_metadump.sh
@@ -8,7 +8,7 @@ OPTS=" "
 DBOPTS=" "
 USAGE="Usage: xfs_metadump [-aefFogwV] [-m max_extents] [-l logdev] source target"
 
-while getopts "aefgl:m:owFV" c
+while getopts "aefgl:m:owFv:V" c
 do
 	case $c in
 	a)	OPTS=$OPTS"-a ";;
@@ -20,6 +20,7 @@ do
 	f)	DBOPTS=$DBOPTS" -f";;
 	l)	DBOPTS=$DBOPTS" -l "$OPTARG" ";;
 	F)	DBOPTS=$DBOPTS" -F";;
+	v)	OPTS=$OPTS"-v "$OPTARG" ";;
 	V)	xfs_db -p xfs_metadump -V
 		status=$?
 		exit $status
diff --git a/man/man8/xfs_metadump.8 b/man/man8/xfs_metadump.8
index c0e79d77..1732012c 100644
--- a/man/man8/xfs_metadump.8
+++ b/man/man8/xfs_metadump.8
@@ -11,6 +11,9 @@ xfs_metadump \- copy XFS filesystem metadata to a file
 ] [
 .B \-l
 .I logdev
+] [
+.B \-v
+.I version
 ]
 .I source
 .I target
@@ -74,6 +77,12 @@ metadata such as filenames is not considered sensitive.  If obfuscation
 is required on a metadump with a dirty log, please inform the recipient
 of the metadump image about this situation.
 .PP
+The contents of an external log device can be dumped only when using the v2
+format.
+Metadump in v2 format can be generated by passing the "-v 2" option.
+Metadump in v2 format is generated by default if the filesystem has an
+external log and the metadump version to use is not explicitly mentioned.
+.PP
 .B xfs_metadump
 should not be used for any purposes other than for debugging and reporting
 filesystem problems. The most common usage scenario for this tool is when
@@ -134,6 +143,11 @@ this value.  The default size is 2097151 blocks.
 .B \-o
 Disables obfuscation of file names and extended attributes.
 .TP
+.B \-v
+The format of the metadump file to be produced.
+Valid values are 1 and 2.
+The default metadump format is 1.
+.TP
 .B \-w
 Prints warnings of inconsistent metadata encountered to stderr. Bad metadata
 is still copied.
-- 
2.39.1

