[PATCH 02/14] populate: create hardlinks for parent pointers

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Create some hardlinked files so that we can exercise parent pointers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 common/populate |   38 ++++++++++++++++++++++++++++++++++++++
 src/popdir.pl   |   11 +++++++++++
 2 files changed, 49 insertions(+)


diff --git a/common/populate b/common/populate
index 389a762329..d52167964c 100644
--- a/common/populate
+++ b/common/populate
@@ -376,6 +376,7 @@ _scratch_xfs_populate() {
 	is_rt="$(_xfs_get_rtextents "$SCRATCH_MNT")"
 	is_rmapbt="$(_xfs_has_feature "$SCRATCH_MNT" rmapbt -v)"
 	is_reflink="$(_xfs_has_feature "$SCRATCH_MNT" reflink -v)"
+	is_pptr="$(_xfs_has_feature "$SCRATCH_MNT" parent -v)"
 
 	# Reverse-mapping btree
 	if [ $is_rmapbt -gt 0 ]; then
@@ -412,6 +413,43 @@ _scratch_xfs_populate() {
 		cp --reflink=always "${SCRATCH_MNT}/REFCOUNTBT" "${SCRATCH_MNT}/REFCOUNTBT2"
 	fi
 
+	# Parent pointers
+	if [ $is_pptr -gt 0 ]; then
+		echo "+ parent pointers"
+
+		# Create a couple of parent pointers
+		__populate_create_dir "${SCRATCH_MNT}/PPTRS" 1 '' --hardlink --format "two_%d"
+
+		# Create one xattr leaf block of parent pointers
+		nr="$((blksz * 2 / 16))"
+		__populate_create_dir "${SCRATCH_MNT}/PPTRS" ${nr} '' --hardlink --format "many%04d"
+
+		# Create multiple xattr leaf blocks of large parent pointers
+		nr="$((blksz * 16 / 16))"
+		__populate_create_dir "${SCRATCH_MNT}/PPTRS" ${nr} '' --hardlink --format "y%0254d"
+
+		# Create multiple paths to a file
+		local moof="${SCRATCH_MNT}/PPTRS/moofile"
+		touch "${moof}"
+		for ((i = 0; i < 4; i++)); do
+			mkdir -p "${SCRATCH_MNT}/PPTRS/SUB${i}"
+			ln "${moof}" "${SCRATCH_MNT}/PPTRS/SUB${i}/moofile"
+		done
+
+		# Create parent pointers of various lengths
+		touch "${SCRATCH_MNT}/PPTRS/vlength"
+		local len_len
+		local tst
+		local fname
+		ln "${SCRATCH_MNT}/PPTRS/vlength" "${SCRATCH_MNT}/PPTRS/b"
+		for len in 32 64 96 128 160 192 224 250 255; do
+			len_len="${#len}"
+			tst="$(perl -e "print \"b\" x (${len} - (${len_len} + 1))")"
+			fname="v${tst}${len}"
+			ln "${SCRATCH_MNT}/PPTRS/vlength" "${SCRATCH_MNT}/PPTRS/${fname}"
+		done
+	fi
+
 	# Copy some real files (xfs tests, I guess...)
 	echo "+ real files"
 	test $fill -ne 0 && __populate_fill_fs "${SCRATCH_MNT}" 5
diff --git a/src/popdir.pl b/src/popdir.pl
index dc0c046b7d..950503c621 100755
--- a/src/popdir.pl
+++ b/src/popdir.pl
@@ -17,6 +17,7 @@ GetOptions("start=i" => \$start,
 	   "dir=s" => \$dir,
 	   "remove!" => \$remove,
 	   "help!" => \$help,
+	   "hardlink!" => \$hardlink,
 	   "verbose!" => \$verbose);
 
 
@@ -36,6 +37,7 @@ Options:
   --format=str      printf formatting string for file name ("%08d")
   --verbose         verbose output
   --help            this help screen
+  --hardlink        hardlink subsequent files to the first one created
 EOF
   exit(1) unless defined $help;
   # otherwise...
@@ -51,12 +53,21 @@ $file_mult = 20 if (!defined $file_mult);
 $format = "%08d" if (!defined $format);
 $incr = 1 if (!defined $incr);
 
+if ($hardlink) {
+	$file_mult = 0;
+	$link_fname = sprintf($format, $start);
+}
+
 for ($i = $start; $i <= $end; $i += $incr) {
 	$fname = sprintf($format, $i);
 
 	if ($remove) {
 		$verbose && print "rm $fname\n";
 		unlink($fname) or rmdir($fname) or die("unlink $fname");
+	} elsif ($hardlink && $i > $start) {
+		# hardlink the first file
+		$verbose && print "ln $link_fname $fname\n";
+		link $link_fname, $fname;
 	} elsif ($file_mult == 0 or ($i % $file_mult) == 0) {
 		# create a file
 		$verbose && print "touch $fname\n";