Enable shellcheck to run for select scripts

Enable shellcheck to run on zed scripts,
paxcheck.sh, zfs-tests.sh, zfs.sh, and zloop.sh.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes #5812

Makefile.am

@@ -47,11 +47,14 @@ cstyle:
 
 shellcheck:
 	@if type shellcheck > /dev/null 2>&1; then \
-		(find ${top_srcdir} -type f -name '*.sh.in' -o -type f \
+		shellcheck --exclude=SC1090 --format gcc scripts/paxcheck.sh \
-		 -name '*.sh'; find etc/init.d/zfs*.in -type f) | \
+			scripts/zloop.sh \
+			scripts/zfs-tests.sh \
+			scripts/zfs.sh; \
+		(find cmd/zed/zed.d/*.sh -type f) | \
 		 grep -v 'zfs-script-config' | \
 		 while read file; do \
-			shellcheck --format gcc "$$file"; \
+			shellcheck --exclude=SC1090 --format gcc "$$file"; \
 		 done; \
 	 fi
 

cmd/zed/zed.d/statechange-led.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # Turn off/on the VDEV's enclosure fault LEDs when the pool's state changes.
 #
@@ -24,6 +24,7 @@
 #   2: enclosure leds administratively disabled
 #   3: The led sysfs path passed from ZFS does not exist
 #   4: $ZPOOL not set
+#   5: awk is not installed
 
 [ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
 . "${ZED_ZEDLET_DIR}/zed-functions.sh"
@@ -37,6 +38,7 @@ if [ "${ZED_USE_ENCLOSURE_LEDS}" != "1" ] ; then
 fi
 
 zed_check_cmd "$ZPOOL" || exit 4
+zed_check_cmd awk || exit 5
 
 # Global used in set_led debug print
 vdev=""
@@ -52,7 +54,7 @@ vdev=""
 # Return
 #  0 on success, 3 on missing sysfs path
 #
-function check_and_set_led
+check_and_set_led()
 {
 	file="$1"
 	val="$2"
@@ -86,12 +88,13 @@ function check_and_set_led
         done
 }
 
-function state_to_val {
+state_to_val()
+{
 	state="$1"
-	if [ "$state" == "FAULTED" ] || [ "$state" == "DEGRADED" ] || \
+	if [ "$state" = "FAULTED" ] || [ "$state" = "DEGRADED" ] || \
-	   [ "$state" == "UNAVAIL" ] ; then
+	   [ "$state" = "UNAVAIL" ] ; then
 		echo 1
-	elif [ "$state" == "ONLINE" ] ; then
+	elif [ "$state" = "ONLINE" ] ; then
 		echo 0
 	fi
 }
@@ -107,19 +110,26 @@ function state_to_val {
 # Return
 #  0 on success, 3 on missing sysfs path
 #
-function process_pool
+process_pool()
 {
 	pool="$1"
 	rc=0
 
 	# Lookup all the current LED values and paths in parallel
+	#shellcheck disable=SC2016
 	cmd='echo led_token=$(cat "$VDEV_ENC_SYSFS_PATH/fault"),"$VDEV_ENC_SYSFS_PATH",'
 	out=$($ZPOOL status -vc "$cmd" "$pool" | grep 'led_token=')
-	while read -r vdev state read write chksum therest ; do
 
+	#shellcheck disable=SC2034
+	echo "$out" | while read -r vdev state read write chksum therest; do
 		# Read out current LED value and path
 		tmp=$(echo "$therest" | sed 's/^.*led_token=//g')
-		IFS="," read -r current_val vdev_enc_sysfs_path <<< "$tmp"
+		vdev_enc_sysfs_path=$(echo "$tmp" | awk -F ',' '{print $2}')
+		current_val=$(echo "$tmp" | awk -F ',' '{print $1}')
+
+		if [ "$current_val" != "0" ] ; then
+			current_val=1
+		fi
 
 		if [ -z "$vdev_enc_sysfs_path" ] ; then
 			# Skip anything with no sysfs LED entries
@@ -127,6 +137,7 @@ function process_pool
 		fi
 
 		if [ ! -e "$vdev_enc_sysfs_path/fault" ] ; then
+			#shellcheck disable=SC2030
 			rc=1
 			zed_log_msg "vdev $vdev '$file/fault' doesn't exist"
 			continue;
@@ -134,17 +145,19 @@ function process_pool
 
 		val=$(state_to_val "$state")
 
-		if [ "$current_val" == "$val" ] ; then
+		if [ "$current_val" = "$val" ] ; then
 			# LED is already set correctly
 			continue;
 		fi
 
-		check_and_set_led "$vdev_enc_sysfs_path/fault" "$val"
+		if ! check_and_set_led "$vdev_enc_sysfs_path/fault" "$val"; then
-		(( rc |= $? ))
+			rc=1
+		fi
 
-	done <<< "$out"
+	done
 
-	if [ "$rc" == "0" ] ; then
+	#shellcheck disable=SC2031
+	if [ "$rc" = "0" ] ; then
 		return 0
 	else
 		# We didn't see a sysfs entry that we wanted to set
@@ -155,9 +168,10 @@ function process_pool
 if [ ! -z "$ZEVENT_VDEV_ENC_SYSFS_PATH" ] && [ ! -z "$ZEVENT_VDEV_STATE_STR" ] ; then
 	# Got a statechange for an individual VDEV
 	val=$(state_to_val "$ZEVENT_VDEV_STATE_STR")
-	vdev="$(basename $ZEVENT_VDEV_PATH)"
+	vdev=$(basename "$ZEVENT_VDEV_PATH")
 	check_and_set_led "$ZEVENT_VDEV_ENC_SYSFS_PATH/fault" "$val"
 else
 	# Process the entire pool
-	process_pool "$(zed_guid_to_pool $ZEVENT_POOL_GUID)"
+	poolname=$(zed_guid_to_pool "$ZEVENT_POOL_GUID")
+	process_pool "$poolname"
 fi

cmd/zed/zed.d/statechange-notify.sh

@@ -39,10 +39,10 @@ umask 077
 note_subject="ZFS device fault for pool ${ZEVENT_POOL_GUID} on $(hostname)"
 note_pathname="${TMPDIR:="/tmp"}/$(basename -- "$0").${ZEVENT_EID}.$$"
 {
-    if [ "${ZEVENT_VDEV_STATE_STR}" == "FAULTED" ] ; then
+    if [ "${ZEVENT_VDEV_STATE_STR}" = "FAULTED" ] ; then
         echo "The number of I/O errors associated with a ZFS device exceeded"
         echo "acceptable levels. ZFS has marked the device as faulted."
-    elif [ "${ZEVENT_VDEV_STATE_STR}" == "DEGRADED" ] ; then
+    elif [ "${ZEVENT_VDEV_STATE_STR}" = "DEGRADED" ] ; then
         echo "The number of checksum errors associated with a ZFS device"
         echo "exceeded acceptable levels. ZFS has marked the device as"
         echo "degraded."

cmd/zed/zed.d/zed-functions.sh

@@ -1,3 +1,5 @@
+#!/bin/sh
+# shellcheck disable=SC2039
 # zed-functions.sh
 #
 # ZED helper functions for use in ZEDLETs
@@ -126,6 +128,7 @@ zed_lock()
     #
     eval "exec ${fd}> '${lockfile}'"
     err="$(flock --exclusive "${fd}" 2>&1)"
+    # shellcheck disable=SC2181
     if [ $? -ne 0 ]; then
         zed_log_err "failed to lock \"${lockfile}\": ${err}"
     fi
@@ -162,8 +165,8 @@ zed_unlock()
     fi
 
     # Release the lock and close the file descriptor.
-    #
     err="$(flock --unlock "${fd}" 2>&1)"
+    # shellcheck disable=SC2181
     if [ $? -ne 0 ]; then
         zed_log_err "failed to unlock \"${lockfile}\": ${err}"
     fi
@@ -424,14 +427,14 @@ zed_rate_limit()
 # Return
 #   Pool name
 #
-function zed_guid_to_pool
+zed_guid_to_pool()
 {
 	if [ -z "$1" ] ; then
 		return
 	fi
 
-	guid=$(printf "%llu" $1)
+	guid=$(printf "%llu" "$1")
 	if [ ! -z "$guid" ] ; then
-		$ZPOOL get -H -ovalue,name guid | awk '$1=='$guid' {print $2}'
+		$ZPOOL get -H -ovalue,name guid | awk '$1=='"$guid"' {print $2}'
 	fi
 }

scripts/common.sh.in

@@ -21,7 +21,6 @@ VERBOSE=
 VERBOSE_FLAG=
 FORCE=
 FORCE_FLAG=
-DUMP_LOG=
 ERROR=
 RAID0S=()
 RAID10S=()
@@ -155,17 +154,6 @@ init() {
 	populate $SRC_DIR 10 100
 }
 
-spl_dump_log() {
-	${SYSCTL} -w kernel.spl.debug.dump=1 &>/dev/null
-	local NAME=`dmesg | tail -n 1 | cut -f5 -d' '`
-	${SPLBUILD}/cmd/spl ${NAME} >${NAME}.log
-	echo
-	echo "Dumped debug log: ${NAME}.log"
-	tail -n1 ${NAME}.log
-	echo
-	return 0
-}
-
 check_modules() {
 	local LOADED_MODULES=()
 	local MISSING_MODULES=()
@@ -265,11 +253,6 @@ unload_modules() {
 				egrep "^${NAME} "| ${AWK} '{print $3}'`
 
 		if [ "${USE_COUNT}" = 0 ] ; then
-
-			if [ "${DUMP_LOG}" -a ${NAME} = "spl" ]; then
-				spl_dump_log
-			fi
-
 			unload_module ${MOD} || return 1
 		fi
 	done

scripts/paxcheck.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
 
+# shellcheck disable=SC2039
 if ! type scanelf > /dev/null 2>&1; then
     echo "scanelf (from pax-utils) is required for these checks." >&2
     exit 3
@@ -8,7 +9,7 @@ fi
 RET=0
 
 # check for exec stacks
-OUT="$(scanelf -qyRAF '%e %p' $1)"
+OUT=$(scanelf -qyRAF '%e %p' "$1")
 
 if [ x"${OUT}" != x ]; then
     RET=2
@@ -24,7 +25,7 @@ fi
 
 
 # check for TEXTRELS
-OUT="$(scanelf -qyRAF '%T %p' $1)"
+OUT=$(scanelf -qyRAF '%T %p' "$1")
 
 if [ x"${OUT}" != x ]; then
     RET=2

scripts/zfs-tests.sh

@@ -20,7 +20,7 @@
 #
 # CDDL HEADER END
 #
-basedir="$(dirname $0)"
+basedir=$(dirname "$0")
 
 SCRIPT_COMMON=common.sh
 if [ -f "${basedir}/${SCRIPT_COMMON}" ]; then
@@ -29,7 +29,7 @@ else
 echo "Missing helper script ${SCRIPT_COMMON}" && exit 1
 fi
 
-. $STF_SUITE/include/default.cfg
+. "$STF_SUITE/include/default.cfg"
 
 PROG=zfs-tests.sh
 SUDO=/usr/bin/sudo
@@ -58,24 +58,24 @@ cleanup() {
 
 	if [ $LOOPBACK -eq 1 ]; then
 		for TEST_LOOPBACK in ${LOOPBACKS}; do
-			LOOP_DEV=$(basename $TEST_LOOPBACK)
+			LOOP_DEV=$(basename "$TEST_LOOPBACK")
-			DM_DEV=$(${SUDO} ${DMSETUP} ls 2>/dev/null | \
+			DM_DEV=$(${SUDO} "${DMSETUP}" ls 2>/dev/null | \
-			    grep ${LOOP_DEV} | cut -f1)
+			    grep "${LOOP_DEV}" | cut -f1)
 
 			if [ -n "$DM_DEV" ]; then
-				${SUDO} ${DMSETUP} remove ${DM_DEV} ||
+				${SUDO} "${DMSETUP}" remove "${DM_DEV}" ||
 				    echo "Failed to remove: ${DM_DEV}"
 			fi
 
 			if [ -n "${TEST_LOOPBACK}" ]; then
-				${SUDO} ${LOSETUP} -d ${TEST_LOOPBACK} ||
+				${SUDO} "${LOSETUP}" -d "${TEST_LOOPBACK}" ||
 				    echo "Failed to remove: ${TEST_LOOPBACK}"
 			fi
 		done
 	fi
 
 	for TEST_FILE in ${FILES}; do
-		rm -f ${TEST_FILE} &>/dev/null
+		rm -f "${TEST_FILE}" &>/dev/null
 	done
 }
 trap cleanup EXIT
@@ -87,29 +87,32 @@ trap cleanup EXIT
 # be dangerous and should only be used in a dedicated test environment.
 #
 cleanup_all() {
-	local TEST_POOLS=$(${SUDO} ${ZPOOL} list -H -o name | grep testpool)
+	local TEST_POOLS
-	local TEST_LOOPBACKS=$(${SUDO} ${LOSETUP} -a|grep file-vdev|cut -f1 -d:)
+	TEST_POOLS=$(${SUDO} "${ZPOOL}" list -H -o name | grep testpool)
-	local TEST_FILES=$(ls /var/tmp/file-vdev* 2>/dev/null)
+	local TEST_LOOPBACKS
+	TEST_LOOPBACKS=$(${SUDO} "${LOSETUP}" -a|grep file-vdev|cut -f1 -d:)
+	local TEST_FILES
+	TEST_FILES=$(ls /var/tmp/file-vdev* 2>/dev/null)
 
 	msg
 	msg "--- Cleanup ---"
-	msg "Removing pool(s):     $(echo ${TEST_POOLS} | tr '\n' ' ')"
+	msg "Removing pool(s):     $(echo "${TEST_POOLS}" | tr '\n' ' ')"
 	for TEST_POOL in $TEST_POOLS; do
-		${SUDO} ${ZPOOL} destroy ${TEST_POOL}
+		${SUDO} "${ZPOOL}" destroy "${TEST_POOL}"
 	done
 
-	msg "Removing dm(s):       $(${SUDO} ${DMSETUP} ls |
+	msg "Removing dm(s):       $(${SUDO} "${DMSETUP}" ls |
 	    grep loop | tr '\n' ' ')"
-	${SUDO} ${DMSETUP} remove_all
+	${SUDO} "${DMSETUP}" remove_all
 
-	msg "Removing loopback(s): $(echo ${TEST_LOOPBACKS} | tr '\n' ' ')"
+	msg "Removing loopback(s): $(echo "${TEST_LOOPBACKS}" | tr '\n' ' ')"
 	for TEST_LOOPBACK in $TEST_LOOPBACKS; do
-		${SUDO} ${LOSETUP} -d ${TEST_LOOPBACK}
+		${SUDO} "${LOSETUP}" -d "${TEST_LOOPBACK}"
 	done
 
-	msg "Removing files(s):    $(echo ${TEST_FILES} | tr '\n' ' ')"
+	msg "Removing files(s):    $(echo "${TEST_FILES}" | tr '\n' ' ')"
 	for TEST_FILE in $TEST_FILES; do
-		${SUDO} rm -f ${TEST_FILE}
+		${SUDO} rm -f "${TEST_FILE}"
 	done
 }
 
@@ -193,6 +196,7 @@ while getopts 'hvqxkfd:s:r:?t:u:' OPTION; do
 		exit 1
 		;;
 	v)
+		# shellcheck disable=SC2034
 		VERBOSE=1
 		;;
 	q)
@@ -300,11 +304,11 @@ fi
 # be a normal user account, needs to be configured such that it can
 # run commands via sudo passwordlessly.
 #
-if [ $(id -u) = "0" ]; then
+if [ "$(id -u)" = "0" ]; then
 	fail "This script must not be run as root."
 fi
 
-if [ $(sudo whoami) != "root" ]; then
+if [ "$(sudo whoami)" != "root" ]; then
 	fail "Passwordless sudo access required."
 fi
 
@@ -318,7 +322,7 @@ fi
 #
 # Verify the ZFS module stack if loaded.
 #
-${SUDO} ${ZFS_SH} &>/dev/null
+${SUDO} "${ZFS_SH}" &>/dev/null
 
 #
 # Attempt to cleanup all previous state for a new test run.
@@ -331,7 +335,7 @@ fi
 # By default preserve any existing pools
 #
 if [ -z "${KEEP}" ]; then
-	KEEP=$(${SUDO} ${ZPOOL} list -H -o name)
+	KEEP=$(${SUDO} "${ZPOOL}" list -H -o name)
 	if [ -z "${KEEP}" ]; then
 		KEEP="rpool"
 	fi
@@ -356,7 +360,7 @@ if [ -z "${DISKS}" ]; then
 	#
 	for TEST_FILE in ${FILES}; do
 		[ -f "$TEST_FILE" ] && fail "Failed file exists: ${TEST_FILE}"
-		truncate -s ${FILESIZE} ${TEST_FILE} ||
+		truncate -s "${FILESIZE}" "${TEST_FILE}" ||
 		    fail "Failed creating: ${TEST_FILE} ($?)"
 		DISKS="$DISKS$TEST_FILE "
 	done
@@ -369,17 +373,18 @@ if [ -z "${DISKS}" ]; then
 		check_loop_utils
 
 		for TEST_FILE in ${FILES}; do
-			TEST_LOOPBACK=$(${SUDO} ${LOSETUP} -f)
+			TEST_LOOPBACK=$(${SUDO} "${LOSETUP}" -f)
-			${SUDO} ${LOSETUP} ${TEST_LOOPBACK} ${TEST_FILE} ||
+			${SUDO} "${LOSETUP}" "${TEST_LOOPBACK}" "${TEST_FILE}" ||
 			    fail "Failed: ${TEST_FILE} -> ${TEST_LOOPBACK}"
 			LOOPBACKS="${LOOPBACKS}${TEST_LOOPBACK} "
-			DISKS="$DISKS$(basename $TEST_LOOPBACK) "
+			BASELOOPBACKS=$(basename "$TEST_LOOPBACK")
+			DISKS="$DISKS$BASELOOPBACKS "
 		done
 	fi
 fi
 
-NUM_DISKS=$(echo ${DISKS} | $AWK '{print NF}')
+NUM_DISKS=$(echo "${DISKS}" | $AWK '{print NF}')
-[ $NUM_DISKS -lt 3 ] && fail "Not enough disks ($NUM_DISKS/3 minimum)"
+[ "$NUM_DISKS" -lt 3 ] && fail "Not enough disks ($NUM_DISKS/3 minimum)"
 
 #
 # Disable SELinux until the ZFS Test Suite has been updated accordingly.
@@ -404,7 +409,7 @@ export KEEP
 export __ZFS_POOL_EXCLUDE
 
 msg "${TEST_RUNNER} ${QUIET} -c ${RUNFILE} -i ${STF_SUITE}"
-${TEST_RUNNER} ${QUIET} -c ${RUNFILE} -i ${STF_SUITE}
+${TEST_RUNNER} ${QUIET} -c "${RUNFILE}" -i "${STF_SUITE}"
 RESULT=$?
 echo
 

scripts/zfs.sh

@@ -2,7 +2,7 @@
 #
 # A simple script to simply the loading/unloading the ZFS module stack.
 
-basedir="$(dirname $0)"
+basedir=$(dirname "$0")
 
 SCRIPT_COMMON=common.sh
 if [ -f "${basedir}/${SCRIPT_COMMON}" ]; then
@@ -11,6 +11,7 @@ else
 echo "Missing helper script ${SCRIPT_COMMON}" && exit 1
 fi
 
+# shellcheck disable=SC2034
 PROG=zfs.sh
 UNLOAD=
 
@@ -26,7 +27,6 @@ OPTIONS:
 	-h      Show this message
 	-v      Verbose
 	-u      Unload modules
-	-d      Save debug log on unload
 
 MODULE-OPTIONS:
 	Must be of the from module="options", for example:
@@ -37,21 +37,19 @@ $0 zfs="zfs_prefetch_disable=1 zfs_mdcomp_disable=1"
 EOF
 }
 
-while getopts 'hvud' OPTION; do
+while getopts 'hvu' OPTION; do
 	case $OPTION in
 	h)
 		usage
 		exit 1
 		;;
 	v)
+		# shellcheck disable=SC2034
 		VERBOSE=1
 		;;
 	u)
 		UNLOAD=1
 		;;
-	d)
-		DUMP_LOG=1
-		;;
 	?)
 		usage
 		exit
@@ -59,7 +57,7 @@ while getopts 'hvud' OPTION; do
 	esac
 done
 
-if [ $(id -u) != 0 ]; then
+if [ "$(id -u)" != 0 ]; then
 	die "Must run as root"
 fi
 

scripts/zloop.sh

@@ -20,7 +20,7 @@
 # Copyright (C) 2016 Lawrence Livermore National Security, LLC.
 #
 
-basedir="$(dirname $0)"
+basedir=$(dirname "$0")
 
 SCRIPT_COMMON=common.sh
 if [ -f "${basedir}/${SCRIPT_COMMON}" ]; then
@@ -29,6 +29,7 @@ else
 	echo "Missing helper script ${SCRIPT_COMMON}" && exit 1
 fi
 
+# shellcheck disable=SC2034
 PROG=zloop.sh
 
 DEFAULTWORKDIR=/var/tmp
@@ -56,8 +57,11 @@ function usage
 
 function or_die
 {
+	# shellcheck disable=SC2068
 	$@
+	# shellcheck disable=SC2181
 	if [[ $? -ne 0 ]]; then
+		# shellcheck disable=SC2145
 		echo "Command failed: $@"
 		exit 1
 	fi
@@ -76,14 +80,16 @@ fi
 
 function core_file
 {
+	# shellcheck disable=SC2012 disable=2086
         printf "%s" "$(ls -tr1 $coreglob 2> /dev/null | head -1)"
 }
 
 function core_prog
 {
 	prog=$ZTEST
-	core_id=$($GDB --batch -c $1 | grep "Core was generated by" | \
+	core_id=$($GDB --batch -c "$1" | grep "Core was generated by" | \
 	    tr  \' ' ')
+	# shellcheck disable=SC2076
 	if [[ "$core_id" =~ "zdb "  ]]; then
 		prog=$ZDB
 	fi
@@ -95,23 +101,23 @@ function store_core
 	core="$(core_file)"
 	if [[ $ztrc -ne 0 ]] || [[ -f "$core" ]]; then
 		coreid=$(date "+zloop-%y%m%d-%H%M%S")
-		foundcrashes=$(($foundcrashes + 1))
+		foundcrashes=$((foundcrashes + 1))
 
 		dest=$coredir/$coreid
-		or_die mkdir -p $dest
+		or_die mkdir -p "$dest"
-		or_die mkdir -p $dest/vdev
+		or_die mkdir -p "$dest/vdev"
 
 		echo "*** ztest crash found - moving logs to $dest"
 
-		or_die mv ztest.history $dest/
+		or_die mv ztest.history "$dest/"
-		or_die mv ztest.ddt $dest/
+		or_die mv ztest.ddt "$dest/"
-		or_die mv ztest.out $dest/
+		or_die mv ztest.out "$dest/"
-		or_die mv $workdir/ztest* $dest/vdev/
+		or_die mv "$workdir/ztest*" "$dest/vdev/"
-		or_die mv $workdir/zpool.cache $dest/vdev/
+		or_die mv "$workdir/zpool.cache" "$dest/vdev/"
 
 		# check for core
 		if [[ -f "$core" ]]; then
-			coreprog=$(core_prog $core)
+			coreprog=$(core_prog "$core")
 			corestatus=$($GDB --batch --quiet \
 			    -ex "set print thread-events off" \
 			    -ex "printf \"*\n* Backtrace \n*\n\"" \
@@ -124,11 +130,11 @@ function store_core
 			    -ex "thread apply all bt" \
 			    -ex "printf \"*\n* Backtraces (full) \n*\n\"" \
 			    -ex "thread apply all bt full" \
-			    -ex "quit" $coreprog "$core" | grep -v "New LWP")
+			    -ex "quit" "$coreprog" "$core" | grep -v "New LWP")
 
 			# Dump core + logs to stored directory
-			echo "$corestatus" >>$dest/status
+			echo "$corestatus" >>"$dest/status"
-			or_die mv "$core" $dest/
+			or_die mv "$core" "$dest/"
 
 			# Record info in cores logfile
 			echo "*** core @ $coredir/$coreid/$core:" | \
@@ -149,7 +155,7 @@ while getopts ":ht:c:f:" opt; do
 	case $opt in
 		t ) [[ $OPTARG -gt 0 ]] && timeout=$OPTARG ;;
 		c ) [[ $OPTARG ]] && coredir=$OPTARG ;;
-		f ) [[ $OPTARG ]] && workdir=$(readlink -f $OPTARG) ;;
+		f ) [[ $OPTARG ]] && workdir=$(readlink -f "$OPTARG") ;;
 		h ) usage
 		    exit 2
 		    ;;
@@ -166,13 +172,13 @@ ulimit -c unlimited
 
 if [[ -f "$(core_file)" ]]; then
 	echo -n "There's a core dump here you might want to look at first... "
-	echo "$(core_file)"
+	core_file
 	exit 1
 fi
 
 if [[ ! -d $coredir ]]; then
 	echo "core dump directory ($coredir) does not exist, creating it."
-	or_die mkdir -p $coredir
+	or_die mkdir -p "$coredir"
 fi
 
 if [[ ! -w $coredir ]]; then
@@ -190,7 +196,7 @@ starttime=$(date +%s)
 curtime=$starttime
 
 # if no timeout was specified, loop forever.
-while [[ $timeout -eq 0 ]] || [[ $curtime -le $(($starttime + $timeout)) ]]; do
+while [[ $timeout -eq 0 ]] || [[ $curtime -le $((starttime + timeout)) ]]; do
 	zopt="-VVVVV"
 
 	# switch between common arrangements & fully randomized
@@ -220,6 +226,7 @@ while [[ $timeout -eq 0 ]] || [[ $curtime -le $(($starttime + $timeout)) ]]; do
 	zopt="$zopt -s $size"
 	zopt="$zopt -f $workdir"
 
+	# shellcheck disable=SC2124
 	cmd="$ZTEST $zopt $@"
 	desc="$(date '+%m/%d %T') $cmd"
 	echo "$desc" | tee -a ztest.history
@@ -227,7 +234,7 @@ while [[ $timeout -eq 0 ]] || [[ $curtime -le $(($starttime + $timeout)) ]]; do
 	$cmd >>ztest.out 2>&1
 	ztrc=$?
 	egrep '===|WARNING' ztest.out >>ztest.history
-	$ZDB -U $workdir/zpool.cache -DD ztest >>ztest.ddt
+	$ZDB -U "$workdir/zpool.cache" -DD ztest >>ztest.ddt
 
 	store_core