btrfs-progs: tests: add 006-partitioned-loopdev

Create filesystem on a partitioned loop device, test for "btrfs-progs:
Fix partitioned loop devices resolving".

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

tests/mkfs-tests/006-partitioned-loopdev/test.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+# recognize partitioned loop devices
+
+source $TOP/tests/common
+
+check_prereq mkfs.btrfs
+check_prereq btrfs
+setup_root_helper
+
+run_check truncate -s0 img
+chmod a+w img
+cp partition-1g-1g img
+run_check truncate -s2g img
+
+loopdev=$(run_check_stdout $SUDO_HELPER losetup --partscan --find --show img)
+base=$(basename $loopdev)
+
+# expect partitions named like loop0p1 etc
+for looppart in $(ls /dev/$base?*); do
+	run_check $SUDO_HELPER $TOP/mkfs.btrfs -f $looppart
+	run_check $TOP/btrfs-show-super $looppart
+done
+
+# cleanup
+run_check $SUDO_HELPER losetup -d $loopdev
+run_check truncate -s0 img