loop: test if closing an unbound device is too slow

Based on a patch from James Wang.

Signed-off-by: Omar Sandoval <osandov@fb.com>

diff --git a/tests/loop/003 b/tests/loop/003
new file mode 100755 (executable)
index 0000000..8f638b2
--- /dev/null
+++ b/tests/loop/003
@@ -0,0 +1,41 @@
+#!/bin/bash
+#
+# Regression test for commit 6460495709ae ("Fix loop device flush before
+# configure v3").
+#
+# Copyright (C) 2017 Omar Sandoval
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+DESCRIPTION="time opening and closing an unbound loop device"
+QUICK=1
+
+test() {
+       local loop_dev
+       echo "Running ${TEST_NAME}"
+
+       loop_dev="$(losetup -f)"
+
+       # In a subshell so TIMEFORMAT doesn't get clobbered.
+       (
+       TIMEFORMAT="Test took %0R seconds"
+       {FD}<>"$loop_dev"
+       time for ((i = 0; i < 500; i++)); do
+               $FD>&-
+               $FD<>"$loop_dev"
+       done
+       )
+
+       echo "Test complete"
+}

diff --git a/tests/loop/003.out b/tests/loop/003.out
new file mode 100644 (file)
index 0000000..05ce4e6
--- /dev/null
+++ b/tests/loop/003.out
@@ -0,0 +1,3 @@
+Running loop/003
+Test took 0 seconds
+Test complete