#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2014 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test No. xfs/013
#
# Exercise the free inode btree (finobt). XFS allocates physical inodes in
# chunks of 64. Inode records with at least one free inode are stored in the
# finobt to optimize free inode lookup. This test runs a workload that creates
# and modifies a sparsely allocated set of inodes in combination with an
# fsstress workload.
#
. ./common/preamble
_begin_fstest auto metadata stress

# Import common functions.
. ./common/filter

# Override the default cleanup function.
_cleanup()
{
	$KILLALL_PROG -9 fsstress 2>/dev/null
	wait
	cd /
	_scratch_unmount 2>/dev/null
	rm -f $tmp.*
}

filter_enospc() {
	sed -e '/^.*No space left on device.*/d'
}

_create()
{
	dir=$1
	count=$2

	mkdir -p $dir
	for i in $(seq 0 $count)
	do
		touch $dir/$i 2>&1 | filter_enospc
	done
}

_rand_replace()
{
	dir=$1
	count=$2

	# replace 5% of the dataset
	for i in $(seq 0 $((count / 20)))
	do
		file=$((RANDOM % count))
		rm -f $dir/$file
		touch $dir/$file 2>&1 | filter_enospc
	done
}

_cleaner()
{
	dir=$1
	iters=$2
	mindirs=$3

	iters=$((iters - mindirs))

	for i in $(seq 1 $iters)
	do
		need=$dir/dir$((i + mindirs))
		while [ ! -e $need ]
		do
			sleep 3
			if ! pgrep fsstress > /dev/null 2>&1; then
				echo "fsstress died?"
				return
			fi
		done

		rm -rf $dir/dir$i
	done
}

# real QA test starts here
_supported_fs xfs

_require_scratch
_require_xfs_mkfs_finobt
_require_xfs_finobt
_require_command "$KILLALL_PROG" killall

_scratch_mkfs_xfs "-m crc=1,finobt=1 -d agcount=2" | \
	_filter_mkfs 2>> $seqres.full
_scratch_mount

COUNT=20000	# number of files per directory
LOOPS=15	# last loop iteration
MINDIRS=2	# number of dirs for the cleaner to leave trailing behind the
		# most recent (no less than 2 to prevent an rm from trampling a
		# clone)

# create initial directory
_create $SCRATCH_MNT/dir1 $COUNT

# start background cleaner to remove old directories as new ones are created
_cleaner $SCRATCH_MNT $LOOPS $MINDIRS &

# start a background stress workload on the fs
$FSSTRESS_PROG -d $SCRATCH_MNT/fsstress -n 9999999 -p 2 -S t \
	>> $seqres.full 2>&1 &

# Each cycle clones the current directory and makes a random file replacement
# pass on the new directory. The directory is copied to the next using hard
# links. The replacement pass then randomly removes and replaces ~5% of the
# content in the directory. Files replaced as such are effectively marked to be
# freed by the background cleaner as it moves forward and removes all of the
# previous hard links to the inode. Over several iterations, this workload
# creates a sparsely located set of a free inodes across the set and uses the
# finobt to allocate new inodes for replacement.

for i in $(seq 1 $LOOPS)
do
	# hard link the content of the current directory to the next
	while ! test -d $SCRATCH_MNT/dir$((i+1)); do
		cp -Rl $SCRATCH_MNT/dir$i $SCRATCH_MNT/dir$((i+1)) 2>&1 | \
			filter_enospc
	done

	# do a random replacement of files in the new directory
	_rand_replace $SCRATCH_MNT/dir$((i+1)) $COUNT
done

$KILLALL_PROG fsstress
wait

# clean out the competing fsstress allocations, then everything else
rm -rf $SCRATCH_MNT/fsstress
rm -rf $SCRATCH_MNT/dir*

_scratch_unmount

status=0
exit