#! /bin/bash
# SPDX-License-Identifier: GPL-2.0+
# Copyright (c) 2019 Oracle, Inc.  All Rights Reserved.
#
# FS QA Test No. 531
#
# Stress test creating a lot of unlinked O_TMPFILE files and closing them
# all at once, checking that we don't blow up the filesystem.  This is sort
# of a performance test for the xfs unlinked inode backref patchset, but it
# applies to most other filesystems.
#
# Use every CPU possible to stress the filesystem.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1	# failure is the default!
testfile=$TEST_DIR/$seq.txt
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	cd /
	rm -f $tmp.*
}

# get standard environment, filters and checks
. ./common/rc

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch
_require_test_program "t_open_tmpfiles"

rm -f $seqres.full
_scratch_mkfs >> $seqres.full 2>&1
_scratch_mount

# Try to load up all the CPUs, two threads per CPU.
nr_cpus=$(( $(getconf _NPROCESSORS_ONLN) * 2 ))

# Set ULIMIT_NOFILE to min(file-max / $nr_cpus / 2, 50000 files per LOAD_FACTOR)
# so that this test doesn't take forever or OOM the box
max_files=$((50000 * LOAD_FACTOR))
max_allowable_files=$(( $(cat /proc/sys/fs/file-max) / $nr_cpus / 2 ))
test $max_allowable_files -gt 0 && test $max_files -gt $max_allowable_files && \
	max_files=$max_allowable_files
ulimit -n $max_files

# Open a lot of unlinked files
echo create >> $seqres.full
for i in $(seq 1 $nr_cpus); do
	mkdir $SCRATCH_MNT/$i
	$here/src/t_open_tmpfiles $SCRATCH_MNT/$i >> $seqres.full &
done
wait

# Unmount to prove that we can clean it all
echo umount >> $seqres.full
before=$(date +%s)
_scratch_unmount
after=$(date +%s)
echo "Unmount took $((after - before))s." >> $seqres.full

# Mount so that we can run the usual checks
echo silence is golden
_scratch_mount
status=0
exit