btrfs-progs: tests: Add testcase for rootdir inline extent size

Add a test case for mkfs --rootdir, using files with different file
sizes to check if invalid large inline extent could exist.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/mkfs-tests/014-rootdir-inline-extent/test.sh

@@ -0,0 +1,47 @@
+#!/bin/bash
+# Regression test for mkfs.btrfs --rootdir with inline file extents
+# For any large inline file extent, btrfs check could already report it
+
+source "$TEST_TOP/common"
+
+check_global_prereq fallocate
+check_prereq mkfs.btrfs
+
+prepare_test_dev
+
+tmp=$(mktemp -d --tmpdir btrfs-progs-mkfs.rootdirXXXXXXX)
+
+pagesize=$(getconf PAGESIZE)
+create_file()
+{
+	local size=$1
+	# Reuse size as filename
+	run_check fallocate -l $size "$tmp/$size"
+}
+
+test_mkfs_rootdir()
+{
+	nodesize=$1
+	run_check "$TOP/mkfs.btrfs" --nodesize $nodesize -f --rootdir "$tmp" \
+		"$TEST_DEV"
+	run_check $SUDO_HELPER "$TOP/btrfs" check "$TEST_DEV"
+}
+
+# Use power of 2 from 512 to 64K (maximum node size) as base file size
+for i in 512 1024 2048 4096 8192 16384 32768; do
+	create_file $(($i - 102))
+	# 101 is the overhead size for max inline extent
+	create_file $(($i - 101))
+	create_file $(($i - 100))
+
+	create_file $(($i - 1))
+	create_file $i
+	create_file $(($i + 1))
+done
+
+for nodesize in 4096 8192 16384 32768 65536; do
+	if [ $nodesize -ge $pagesize ]; then
+		test_mkfs_rootdir $nodesize
+	fi
+done
+rm -rf -- "$tmp"