From 63c4b435e0adb6a4b81c7b96637669371867167d Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <djwong@kernel.org>
Date: Thu, 20 Feb 2025 13:47:06 -0800
Subject: [PATCH] common/ext4: reformat external logs during mdrestore
 operations

The e2image file format doesn't support the capture of external log
devices, which means that mdrestore ought to reformat the external log
to get the restored filesystem to work again.  The common/populate code
could already do this, so push it to the common ext4 helper.

While we're at it, fix the uncareful usage of SCRATCH_LOGDEV in the
populate code.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zorro Lang <zlang@kernel.org>
---
 common/ext4     | 17 ++++++++++++++++-
 common/populate | 20 ++++++--------------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/common/ext4 b/common/ext4
index 13921bb8..e1b336d3 100644
--- a/common/ext4
+++ b/common/ext4
@@ -134,7 +134,8 @@ _ext4_mdrestore()
 {
 	local metadump="$1"
 	local device="$2"
-	shift; shift
+	local logdev="$3"
+	shift; shift; shift
 	local options="$@"
 
 	# If we're configured for compressed dumps and there isn't already an
@@ -148,6 +149,20 @@ _ext4_mdrestore()
 	test -r "$metadump" || return 1
 
 	$E2IMAGE_PROG $options -r "${metadump}" "${SCRATCH_DEV}"
+	res=$?
+	test $res -ne 0 && return $res
+
+	# ext4 cannot e2image external logs, so we have to reformat the log
+	# device to match the restored fs
+	if [ "${logdev}" != "none" ]; then
+		local fsuuid="$($DUMPE2FS_PROG -h "${SCRATCH_DEV}" 2>/dev/null | \
+				grep 'Journal UUID:' | \
+				sed -e 's/Journal UUID:[[:space:]]*//g')"
+		$MKFS_EXT4_PROG -O journal_dev "${logdev}" \
+				-F -U "${fsuuid}"
+		res=$?
+	fi
+	return $res
 }
 
 # this test requires the ext4 kernel support crc feature on scratch device
diff --git a/common/populate b/common/populate
index e6804cbc..32dc5275 100644
--- a/common/populate
+++ b/common/populate
@@ -1034,20 +1034,12 @@ _scratch_populate_restore_cached() {
 		return $?
 		;;
 	"ext2"|"ext3"|"ext4")
-		_ext4_mdrestore "${metadump}" "${SCRATCH_DEV}"
-		ret=$?
-		test $ret -ne 0 && return $ret
-
-		# ext4 cannot e2image external logs, so we have to reformat
-		# the scratch device to match the restored fs
-		if [ -n "${SCRATCH_LOGDEV}" ]; then
-			local fsuuid="$($DUMPE2FS_PROG -h "${SCRATCH_DEV}" 2>/dev/null | \
-					grep 'Journal UUID:' | \
-					sed -e 's/Journal UUID:[[:space:]]*//g')"
-			$MKFS_EXT4_PROG -O journal_dev "${SCRATCH_LOGDEV}" \
-					-F -U "${fsuuid}"
-		fi
-		return 0
+		local logdev=none
+		[ "$USE_EXTERNAL" = yes -a ! -z "$SCRATCH_LOGDEV" ] && \
+			logdev=$SCRATCH_LOGDEV
+
+		_ext4_mdrestore "${metadump}" "${SCRATCH_DEV}" "${logdev}"
+		return $?
 		;;
 	esac
 	return 1
-- 
2.39.5