1 files changed, 83 insertions, 0 deletions
diff --git a/tests/rm/ext3-perf.sh b/tests/rm/ext3-perf.sh
new file mode 100755
index 0000000..744298a
--- /dev/null
+++ b/tests/rm/ext3-perf.sh
@@ -0,0 +1,83 @@
+#!/bin/sh
+# ensure that "rm -rf DIR-with-many-entries" is not O(N^2)
+
+# Copyright (C) 2008-2022 Free Software Foundation, Inc.
+
+# 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 <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ rm
+
+very_expensive_
+
+# In a circa 2008 benchmark, using rm -rf to remove a 400k-entry directory took:
+# - 9 seconds with the patch, on a 2-yr-old system
+# - 350 seconds without the patch, on a high-end system (disk 20-30% faster)
+threshold_seconds=60
+
+# The number of entries in our test directory.
+n=400000
+
+# Choose a value that is large enough to ensure an accidentally
+# regressed rm would require much longer than $threshold_seconds to remove
+# the directory.  With n=400k, pre-patch GNU rm would require about 350
+# seconds even on a fast disk.  On a circa 2006 system, the
+# patched version of rm requires about 10 seconds, so even if you
+# choose to enable very expensive tests with a device that is much slower,
+# the test should still succeed.
+
+# Skip unless "." is on an ext[34] file system.
+# FIXME-maybe: try to find a suitable file system or allow
+# the user to specify it via an envvar.
+df -T -t ext3 -t ext4dev -t ext4 . \
+  || skip_ 'this test runs only on an ext3 or ext4 file system'
+
+# Skip if there are too few inodes free.  Require some slack.
+free_inodes=$(stat -f --format=%d .) || framework_failure_
+min_free_inodes=$(expr 12 \* $n / 10)
+test $min_free_inodes -lt $free_inodes \
+  || skip_ "too few free inodes on '.': $free_inodes;" \
+      "this test requires at least $min_free_inodes"
+
+ok=0
+start=$(date +%s)
+mkdir d &&
+  cd d &&
+    seq $n | xargs touch &&
+    test -f 1 &&
+    test -f $n &&
+  cd .. &&
+  ok=1
+test $ok = 1 || framework_failure_
+setup_duration=$(expr $(date +%s) - $start)
+echo creating a $n-entry directory took $setup_duration seconds
+
+# If set-up took longer than the default $threshold_seconds,
+# use the longer set-up duration as the limit.
+test $threshold_seconds -lt $setup_duration \
+  && threshold_seconds=$setup_duration
+
+start=$(date +%s)
+timeout ${threshold_seconds}s rm -rf d; err=$?
+duration=$(expr $(date +%s) - $start)
+
+case $err in
+  124) fail=1; echo rm took longer than $threshold_seconds seconds;;
+  0) ;;
+  *) fail=1;;
+esac
+
+echo removing a $n-entry directory took $duration seconds
+
+Exit $fail