[RFC PATCH v4 1/8] ext4: add common helper to check whether dirdata is applied

From: Artem Blagodarenko <[email protected]>

Add a helper that lists a directory with the -lD flags and checks
whether any dirdata fields exist.

This helper will be used by subsequent dirdata-related patches.

Signed-off-by: Artem Blagodarenko <[email protected]>
---
 common/ext4 | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/common/ext4 b/common/ext4
index a2ce456d..d36ae40a 100644
--- a/common/ext4
+++ b/common/ext4
@@ -242,3 +242,66 @@ _ext4_get_inum_iflags() {
 	debugfs -R "stat <${inumber}>" "${dev}" 2> /dev/null | \
 			sed -n 's/^.*Flags: \([0-9a-fx]*\).*$/\1/p'
 }
+
+# Helper to dump directory structure with hash info (requires dirdata feature)
+# This is useful for verifying that dirdata is storing hash information
+_dump_dir_structure()
+{
+	local dir=$1
+	local filename=$2
+	local dir_name=$(basename $dir)
+	local expected=$3
+
+	# Flush dirty filesystem buffers before reading the raw device via debugfs.
+	# ext4 with journaling writes directory-block changes to the journal first;
+	# the actual block in the backing file is not updated until checkpoint/sync.
+	# Without this sync, debugfs (which reads the loop device directly) may see
+	# stale pre-transaction data and show empty or missing dirdata fields.
+	sync
+
+	local debugfs_output=$({
+		echo "cd $dir_name"
+		echo "ls -lD ."
+		echo "quit"
+	} | debugfs $SCRATCH_DEV 2>/dev/null)
+
+	echo "  [DEBUG] debugfs output for $dir_name:" >>$seqres.full
+	echo "$debugfs_output" | grep -v "^debugfs:" | sed 's/^/    /' >>$seqres.full
+
+	# When a specific filename is given, restrict to that entry's line only.
+	# For encrypted directories the on-disk name is ciphertext, so match by
+	# inode number (first field in debugfs ls -lD output) instead of name.
+	local search_scope="$debugfs_output"
+	if [ -n "$filename" ]; then
+		local inum
+		inum=$(stat -c '%i' "$dir/$filename" 2>/dev/null)
+		if [ -n "$inum" ]; then
+			search_scope=$(echo "$debugfs_output" | awk -v n="$inum" '$1 == n')
+			# Plain-text fallback: if inode match is empty (old debugfs
+			# format or different column order) try by filename.
+			[ -z "$search_scope" ] && \
+				search_scope=$(echo "$debugfs_output" | grep -F " $filename")
+		else
+			search_scope=$(echo "$debugfs_output" | grep -F " $filename")
+		fi
+	fi
+
+	# Check if hash data is present (encryption+casefold+dirdata case)
+	# or if fid data is present (dirdata+encryption or dirdata only case)
+	if echo "$search_scope" | grep -q "fid="; then
+		local fid_value=$(echo "$search_scope" | grep -o "fid=[^ ]*" | head -1 | sed 's/^fid=//')
+		if [ "$fid_value" = "$expected" ]; then
+			echo "  Directory structure of $dir_name: OK (dirdata verified)"
+			return 0
+		else
+			echo "  Directory structure of $dir_name: FAILED (fid mismatch: got '$fid_value', expected '$expected')"
+			return 1
+		fi
+	elif echo "$search_scope" | grep -q "hash="; then
+		echo "  Directory structure of $dir_name: OK (dirdata verified)"
+		return 0
+	else
+		echo "  Directory structure of $dir_name: FAILED (no dirdata)"
+		return 1
+	fi
+}
-- 
2.43.7