btrfs-progs: tests: mkfs: don't overwrite first 1M for single

Add test case to check if the first device extent is occupying reserved
0~1M range.

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

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/mkfs-tests/013-reserved-1M-for-single/test.sh b/tests/mkfs-tests/013-reserved-1M-for-single/test.sh
new file mode 100755
index 00000000..775573e0
--- /dev/null
+++ b/tests/mkfs-tests/013-reserved-1M-for-single/test.sh
@@ -0,0 +1,38 @@
+#!/bin/bash
+# Test if "-m single" or "--mixed" can cause dev extent to use the reserved 1M
+# range
+#
+# Other profiles will cause mkfs.btrfs to allocate new meta/sys chunks
+# using btrfs_alloc_chunk() which won't use the 0~1M range, so other profiles
+# are safe.
+
+source "$TOP/tests/common"
+
+check_prereq mkfs.btrfs
+check_prereq btrfs
+
+prepare_test_dev
+
+do_one_test ()
+{
+	run_check "$TOP/mkfs.btrfs" -f "$@" "$TEST_DEV"
+
+	# Use dev-extent tree to find first device extent
+	first_dev_extent=$(run_check_stdout "$TOP/btrfs" inspect-internal \
+		dump-tree -t device "$TEST_DEV" | \
+		grep -oP '(?<=DEV_EXTENT )[[:digit:]]*' | head -n1)
+
+	if [ -z $first_dev_extent ]; then
+		_fail "failed to get first device extent"
+	fi
+
+	echo "first dev extent starts at $first_dev_extent" >> "$RESULTS"
+	echo "reserved range is [0, $(( 1024 * 1024)))" >> "$RESULTS"
+	# First device extent should not start below 1M
+	if [ $first_dev_extent -lt $(( 1024 * 1024 )) ]; then
+		_fail "first device extent occupies reserved 0~1M range"
+	fi
+}
+
+do_one_test --mixed
+do_one_test -m single