#
# Common btrfs specific functions
#

. common/module

# The recommended way to execute simple "btrfs" command.
_btrfs()
{
	run_check $BTRFS_UTIL_PROG $*
}

_btrfs_get_subvolid()
{
	local mnt=$1
	local name=$2

	$BTRFS_UTIL_PROG subvolume list $mnt | grep -E "\s$name$" | $AWK_PROG '{ print $2 }'
}

# _require_btrfs_command <command> [<subcommand>|<option>]
# We check for btrfs and (optionally) features of the btrfs command
# This function support both subfunction like "inspect-internal dump-tree" and
# options like "check --qgroup-report", and also subfunction options like
# "subvolume delete --subvolid"
_require_btrfs_command()
{
	local cmd=$1
	local param=$2
	local param_arg=$3
	local safe_param

	_require_command "$BTRFS_UTIL_PROG" btrfs
	if [ -z "$1" ]; then
		return 1;
	fi
	$BTRFS_UTIL_PROG $cmd --help &> /dev/null
	[ $? -eq 0 ] || _notrun "$BTRFS_UTIL_PROG too old (must support $cmd)"

	test -z "$param" && return

	# If $param is an option, replace leading "-"s for grep
	if [ ${param:0:1} == "-" ]; then
		safe_param=$(echo $param | sed 's/^-*//')
		$BTRFS_UTIL_PROG $cmd --help | grep -wq $safe_param || \
			_notrun "$BTRFS_UTIL_PROG too old (must support $cmd $param)"
		return
	fi

	$BTRFS_UTIL_PROG $cmd $param --help &> /dev/null
	[ $? -eq 0 ] || _notrun "$BTRFS_UTIL_PROG too old (must support $cmd $param)"

	test -z "$param_arg" && return

	# replace leading "-"s for grep
	safe_param=$(echo $param_arg | sed 's/^-*//')
	$BTRFS_UTIL_PROG $cmd $param --help | grep -wq $safe_param || \
		_notrun "$BTRFS_UTIL_PROG too old (must support $cmd $param $param_arg)"
}

# Require extra check on btrfs qgroup numbers
_require_btrfs_qgroup_report()
{
	_require_btrfs_command check --qgroup-report
	touch ${RESULT_DIR}/require_scratch.require_qgroup_report
}

_require_btrfs_dump_super()
{
	if [ ! -x "$BTRFS_SHOW_SUPER_PROG" ]; then
		_require_command "$BTRFS_UTIL_PROG" btrfs
		if ! $BTRFS_UTIL_PROG inspect-internal dump-super --help >& /dev/null; then
			_notrun "Missing btrfs-show-super or inspect-internal dump-super"
		fi
		BTRFS_SHOW_SUPER_PROG="$BTRFS_UTIL_PROG inspect-internal dump-super"
	fi
}

_require_btrfs_mkfs_feature()
{
	if [ -z $1 ]; then
		echo "Missing feature name argument for _require_btrfs_mkfs_feature"
		exit 1
	fi
	feat=$1
	$MKFS_BTRFS_PROG -O list-all 2>&1 | \
		grep '^[ \t]*'"$feat"'\b' > /dev/null 2>&1
	[ $? -eq 0 ] || \
		_notrun "Feature $feat not supported in the available version of mkfs.btrfs"
}

_require_btrfs_mkfs_uuid_option()
{
	local cnt

	cnt=$($MKFS_BTRFS_PROG --help 2>&1 | \
				grep -E --count -- "--uuid|--device-uuid")
	if [ $cnt != 2 ]; then
		_notrun "Require $MKFS_BTRFS_PROG with --uuid and --device-uuid options"
	fi
}

_require_btrfs_fs_feature()
{
	if [ -z $1 ]; then
		echo "Missing feature name argument for _require_btrfs_fs_feature"
		exit 1
	fi
	feat=$1
	modprobe btrfs > /dev/null 2>&1
	[ -e /sys/fs/btrfs/features/$feat ] || \
		_notrun "Feature $feat not supported by the available btrfs version"
}

_require_btrfs_fs_sysfs()
{
	modprobe btrfs > /dev/null 2>&1
	[ -e /sys/fs/btrfs/features ] || \
		_notrun "Sysfs not supported by the available btrfs version"

}

_require_btrfs_no_compress()
{
	if _normalize_mount_options "$MOUNT_OPTIONS" | grep -q "compress"; then
		_notrun "This test requires no compression enabled"
	fi
}

_require_btrfs_no_nodatacow()
{
	if _normalize_mount_options "$MOUNT_OPTIONS" | grep -q "nodatacow"; then
		_notrun "This test requires no nodatacow enabled"
	fi
}

_require_btrfs_free_space_tree()
{
	_scratch_mkfs > /dev/null 2>&1
	if ! $BTRFS_UTIL_PROG inspect-internal dump-super $SCRATCH_DEV | \
		grep -q "FREE_SPACE_TREE"
	then
		_notrun "This test requires a free-space-tree"
	fi
}

_require_btrfs_no_block_group_tree()
{
	_scratch_mkfs > /dev/null 2>&1
	if $BTRFS_UTIL_PROG inspect-internal dump-super $SCRATCH_DEV | \
		grep -q "BLOCK_GROUP_TREE"
	then
		_notrun "This test requires no block-group-tree"
	fi
}

_check_btrfs_filesystem()
{
	device=$1

	# If type is set, we're mounted
	type=`_fs_type $device`
	ok=1

	if [ "$type" = "$FSTYP" ]; then
		# mounted ...
		mountpoint=`_umount_or_remount_ro $device`
	fi

	if [ -f ${RESULT_DIR}/require_scratch.require_qgroup_report ]; then
		$BTRFS_UTIL_PROG check $device --qgroup-report > $tmp.qgroup_report 2>&1
		if grep -qE "Counts for qgroup.*are different" $tmp.qgroup_report ; then
			_log_err "_check_btrfs_filesystem: filesystem on $device has wrong qgroup numbers"
			echo "*** qgroup_report.$FSTYP output ***"	>>$seqres.full
			cat $tmp.qgroup_report				>>$seqres.full
			echo "*** qgroup_report.$FSTYP output ***"	>>$seqres.full
		fi
		rm -f $tmp.qgroup_report
	fi

	$BTRFS_UTIL_PROG check $device >$tmp.fsck 2>&1
	if [ $? -ne 0 ]; then
		_log_err "_check_btrfs_filesystem: filesystem on $device is inconsistent"
		echo "*** fsck.$FSTYP output ***"	>>$seqres.full
		cat $tmp.fsck				>>$seqres.full
		echo "*** end fsck.$FSTYP output"	>>$seqres.full

		ok=0
	fi
	rm -f $tmp.fsck

	if [ $ok -eq 0 ] && [ "$DUMP_CORRUPT_FS" = "1" ]; then
		local flatdev="$(basename "$device")"
		_btrfs_metadump "$device" "$seqres.$flatdev.check.md" >>$seqres.full
	fi

	if [ $ok -eq 0 ]; then
		echo "*** mount output ***"		>>$seqres.full
		_mount					>>$seqres.full
		echo "*** end mount output"		>>$seqres.full
	elif [ "$type" = "$FSTYP" ]; then
		# was mounted ...
		_mount_or_remount_rw "$MOUNT_OPTIONS" $device $mountpoint
		ok=$?
	fi

	if [ $ok -eq 0 ]; then
		status=1
		if [ "$iam" != "check" ]; then
			exit 1
		fi
		return 1
	fi

	return 0
}

_require_btrfs_dev_del_by_devid()
{
	$BTRFS_UTIL_PROG device delete --help | grep -E devid > /dev/null 2>&1
	[ $? -eq 0 ] || _notrun "$BTRFS_UTIL_PROG too old "\
			"(must support 'btrfs device delete <devid> /<mnt>')"
}

# get btrfs profile configs being tested
#
# A set of pre-set profile configs are exported via _btrfs_profile_configs
# array. Default configs can be overridden by setting BTRFS_PROFILE_CONFIGS
# var in the format "metadata_profile:data_profile", multiple configs can be
# seperated by space, e.g.
# export BTRFS_PROFILE_CONFIGS="raid0:raid0 raid1:raid1 dup:single"
_btrfs_get_profile_configs()
{
	if [ "$FSTYP" != "btrfs" ]; then
		return
	fi

	modprobe btrfs > /dev/null 2>&1

	local unsupported=()
	if [ "$1" == "replace" ]; then
		# We can't do replace with these profiles because they
		# imply only one device ($SCRATCH_DEV), and we need to
		# keep $SCRATCH_DEV around for _scratch_mount
		# and _check_scratch_fs.
		unsupported+=(
			"dup"
		)
	elif [ "$1" == "replace-missing" ]; then
		# We can't replace missing devices with these profiles
		# because there isn't enough redundancy.
		unsupported+=(
			"single"
			"dup"
			"raid0"
		)
	fi

	if [ ! -e /sys/fs/btrfs/features/raid56 ]; then
		# We don't have raid56 compiled in, remove them
		unsupported+=(
			"raid5"
			"raid6"
		)
	fi

	if _scratch_btrfs_is_zoned; then
		# Zoned btrfs only supports SINGLE profile
		unsupported+=(
			"dup"
			"raid0"
			"raid1"
			"raid1c3"
			"raid1c4"
			"raid10"
			"raid5"
			"raid6"
		)
	fi

	if [ -z "$BTRFS_PROFILE_CONFIGS" ]; then
		# Default configurations to test.
		local configs=(
			"single:single"
			"dup:single"
			"raid0:raid0"
			"raid1:raid0"
			"raid1:raid1"
			"raid10:raid10"
			"raid5:raid5"
			"raid6:raid6"
		)
		if [ "$1" == "dup" ]; then
			configs+=("dup:dup")
		fi
	else
		# User-provided configurations.
		local configs=(${BTRFS_PROFILE_CONFIGS[@]})
	fi

	_btrfs_profile_configs=()
	for cfg in "${configs[@]}"; do
		local supported=true
		local profiles=(${cfg/:/ })

		for unsupp in "${unsupported[@]}"; do
			if [ "${profiles[0]}" == "$unsupp" -o "${profiles[1]}" == "$unsupp" ]; then
				supported=false
			fi
		done
		if "$supported"; then
			_btrfs_profile_configs+=("-m ${profiles[0]} -d ${profiles[1]}")
		fi
	done
	export _btrfs_profile_configs
}

# stress btrfs by running balance operation in a loop
_btrfs_stress_balance()
{
	local options=$@
	while true; do
		_run_btrfs_balance_start $options >> $seqres.full
	done
}

# Kill a background process running _btrfs_stress_balance()
_btrfs_kill_stress_balance_pid()
{
	local balance_pid=$1

	# Ignore if process already died.
	kill $balance_pid &> /dev/null
	wait $balance_pid &> /dev/null
	# Wait for the balance operation to finish.
	while pgrep -f "btrfs balance start" > /dev/null; do
		sleep 1
	done
}

# stress btrfs by creating/mounting/umounting/deleting subvolume in a loop
_btrfs_stress_subvolume()
{
	local btrfs_dev=$1
	local btrfs_mnt=$2
	local subvol_name=$3
	local subvol_mnt=$4
	local stop_file=$5

	rm -f $stop_file
	mkdir -p $subvol_mnt
	while [ ! -e $stop_file ]; do
		$BTRFS_UTIL_PROG subvolume create $btrfs_mnt/$subvol_name
		$MOUNT_PROG -o subvol=$subvol_name $btrfs_dev $subvol_mnt
		$UMOUNT_PROG $subvol_mnt
		$BTRFS_UTIL_PROG subvolume delete $btrfs_mnt/$subvol_name
	done
}

# Kill a background process running _btrfs_stress_subvolume()
_btrfs_kill_stress_subvolume_pid()
{
	local subvol_pid=$1
	local stop_file=$2

	touch $stop_file
	# Ignore if process already died.
	wait $subvol_pid &> /dev/null
	rm -f $stop_file
}

# stress btrfs by running scrub in a loop
_btrfs_stress_scrub()
{
	local btrfs_mnt=$1
	while true; do
		$BTRFS_UTIL_PROG scrub start -B $btrfs_mnt
	done
}

# Kill a background process running _btrfs_stress_scrub()
_btrfs_kill_stress_scrub_pid()
{
       local scrub_pid=$1

       # Ignore if process already died.
       kill $scrub_pid &> /dev/null
       wait $scrub_pid &> /dev/null
       # Wait for the scrub operation to finish.
       while pgrep -f "btrfs scrub start" > /dev/null; do
               sleep 1
       done
}

# stress btrfs by defragmenting every file/dir in a loop and compress file
# contents while defragmenting if second argument is not "nocompress"
_btrfs_stress_defrag()
{
	local btrfs_mnt=$1
	local compress=$2

	while true; do
		if [ "$compress" == "nocompress" ]; then
			find $btrfs_mnt \( -type f -o -type d \) -exec \
			$BTRFS_UTIL_PROG filesystem defrag {} \;
		else
			find $btrfs_mnt \( -type f -o -type d \) -exec \
			$BTRFS_UTIL_PROG filesystem defrag -clzo {} \;
			find $btrfs_mnt \( -type f -o -type d \) -exec \
			$BTRFS_UTIL_PROG filesystem defrag -czlib {} \;
		fi
	done
}

# Kill a background process running _btrfs_stress_defrag()
_btrfs_kill_stress_defrag_pid()
{
       local defrag_pid=$1

       # Ignore if process already died.
       kill $defrag_pid &> /dev/null
       wait $defrag_pid &> /dev/null
       # Wait for the defrag operation to finish.
       while pgrep -f "btrfs filesystem defrag" > /dev/null; do
               sleep 1
       done
}

# stress btrfs by remounting it with different compression algorithms in a loop
# run this with fsstress running at background could exercise the compression
# code path and ensure no race when switching compression algorithm with constant
# I/O activity.
_btrfs_stress_remount_compress()
{
	local btrfs_mnt=$1
	while true; do
		for algo in no zlib lzo; do
			$MOUNT_PROG -o remount,compress=$algo $btrfs_mnt
		done
	done
}

# Kill a background process running _btrfs_stress_remount_compress()
_btrfs_kill_stress_remount_compress_pid()
{
	local remount_pid=$1
	local btrfs_mnt=$2

	# Ignore if process already died.
	kill $remount_pid &> /dev/null
	wait $remount_pid &> /dev/null
	# Wait for the remount loop to finish.
	while pgrep -f "mount.*${btrfs_mnt}" > /dev/null; do
		sleep 1
	done
}

# stress btrfs by replacing devices in a loop
# Note that at least 3 devices are needed in SCRATCH_DEV_POOL and the last
# device should be free(not used by btrfs)
_btrfs_stress_replace()
{
	local btrfs_mnt=$1

	# The device number in SCRATCH_DEV_POOL should be at least 3,
	# one is SCRATCH_DEV, one is to be replaced, one is free device
	# we won't replace SCRATCH_DEV, see below for reason
	if [ "`echo $SCRATCH_DEV_POOL | wc -w`" -lt 3 ]; then
		echo "_btrfs_stress_replace requires at least 3 devices in SCRATCH_DEV_POOL"
		return
	fi

	# take the last device as the first free_dev
	local free_dev="`echo $SCRATCH_DEV_POOL | $AWK_PROG '{print $NF}'`"

	# free_dev should be really free
	if $BTRFS_UTIL_PROG filesystem show $btrfs_mnt | grep -q "$free_dev"; then
		echo "_btrfs_stress_replace: $free_dev is used by btrfs"
		return
	fi

	# dev_pool is device list being currently used by btrfs (excluding SCRATCH_DEV)
	# and can be replaced. We don't replace SCRATCH_DEV because it will be used in
	# _scratch_mount and _check_scratch_fs etc.
	local dev_pool=`echo $SCRATCH_DEV_POOL | sed -e "s# *$SCRATCH_DEV *##" \
			-e "s# *$free_dev *##"`

	# set the first device in dev_pool as the first src_dev to be replaced
	local src_dev=`echo $dev_pool | $AWK_PROG '{print $1}'`

	echo "dev_pool=$dev_pool"
	echo "free_dev=$free_dev, src_dev=$src_dev"
	while true; do
		echo "Replacing $src_dev with $free_dev"
		$BTRFS_UTIL_PROG replace start -fB $src_dev $free_dev $btrfs_mnt
		if [ $? -ne 0 ]; then
			# don't update src_dev and free_dev if replace failed
			continue
		fi
		dev_pool="$dev_pool $free_dev"
		dev_pool=`echo $dev_pool | sed -e "s# *$src_dev *##"`
		free_dev=$src_dev
		src_dev=`echo $dev_pool | $AWK_PROG '{print $1}'`
	done
}

# Kill a background process running _btrfs_stress_replace()
_btrfs_kill_stress_replace_pid()
{
       local replace_pid=$1

       # Ignore if process already died.
       kill $replace_pid &> /dev/null
       wait $replace_pid &> /dev/null
       # Wait for the replace operation to finish.
       while pgrep -f "btrfs replace start" > /dev/null; do
               sleep 1
       done
}

# find the right option to force output in bytes, older versions of btrfs-progs
# print that by default, newer print human readable numbers with unit suffix
_btrfs_qgroup_units()
{
	$BTRFS_UTIL_PROG qgroup show --help 2>&1 | grep -q -- --raw && echo "--raw"
}

_btrfs_compression_algos()
{
	echo zlib
	for feature in /sys/fs/btrfs/features/compress_*; do
		echo "${feature#/sys/fs/btrfs/features/compress_}"
	done
}

# run btrfs balance start with required --full-balance if available.
_run_btrfs_balance_start()
{
	local bal_opt=""

	$BTRFS_UTIL_PROG balance start --help | grep -q "full-balance"
	(( $? == 0 )) && bal_opt="--full-balance"

	$BTRFS_UTIL_PROG balance start $bal_opt $*
}

#return the sector size of the btrfs scratch fs
_scratch_btrfs_sectorsize()
{
	$BTRFS_UTIL_PROG inspect-internal dump-super $SCRATCH_DEV |\
		grep sectorsize | $AWK_PROG '{print $2}'
}

_btrfs_supports_forget()
{
	$BTRFS_UTIL_PROG device scan --help | grep -wq forget && \
		$BTRFS_UTIL_PROG device scan --forget > /dev/null 2>&1
}

_require_btrfs_forget_or_module_loadable()
{
	_btrfs_supports_forget && return

	_require_loadable_fs_module "btrfs"
}

_btrfs_forget_or_module_reload()
{
	_btrfs_supports_forget && return

	_reload_fs_module "btrfs"
}

# Test cases which utilized _btrfs_forget_or_module_reload() must call this
# to make sure TEST_DEV can still be mounted. As TEST_DEV can be part of a
# multi-device btrfs.
_btrfs_rescan_devices()
{
	$BTRFS_UTIL_PROG device scan &> /dev/null
}

_scratch_btrfs_is_zoned()
{
	[ `_zone_type ${SCRATCH_DEV}` != "none" ] && return 0
	return 1
}

_btrfs_get_fsid()
{
	local fsid
	local mnt=$1

	fsid=$($BTRFS_UTIL_PROG filesystem show $mnt |grep uuid: |\
	       $AWK_PROG '{print $NF}')

	echo $fsid
}

_require_btrfs_sysfs_fsid()
{
	local fsid

	fsid=$(_btrfs_get_fsid $TEST_DIR)

	# Check if the kernel has sysfs fsid support.
	# Following kernel patch adds it:
	#   btrfs: sysfs add devinfo/fsid to retrieve fsid from the device
	test -f /sys/fs/btrfs/$fsid/devinfo/1/fsid ||\
		_notrun "Need btrfs sysfs fsid support"
}

# If test doesn't want v1 cache to take up data space, there's no longer need
# the "nospace_cache" mount option if the filesystem is already using v2 cache.
# Since v2 cache is using metadata space, it will no longer take up data space.
_btrfs_no_v1_cache_opt()
{
	if $BTRFS_UTIL_PROG inspect-internal dump-tree $SCRATCH_DEV |\
	   grep -q "FREE_SPACE_TREE"; then
		return
	fi
	echo -n "-onospace_cache"
}

# Require certain sectorsize support
_require_btrfs_support_sectorsize()
{
	local sectorsize=$1

	# PAGE_SIZE as sectorsize is always supported
	if [ $sectorsize -eq $(_get_page_size) ]; then
		return
	fi

	test -f /sys/fs/btrfs/features/supported_sectorsizes || \
		_notrun "no subpage support found"
	grep -wq $sectorsize /sys/fs/btrfs/features/supported_sectorsizes || \
		_notrun "sectorsize $sectorsize is not supported"
}

_require_btrfs_inline_extents_creation()
{
	local ino

	_require_xfs_io_command fiemap
	_require_scratch

	_scratch_mkfs &> /dev/null
	_scratch_mount -o max_inline=2048,compress=none
	_pwrite_byte 0x00 0 1024 $SCRATCH_MNT/inline &> /dev/null
	sync
	$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/inline | tail -n 1 > $tmp.fiemap
	_scratch_unmount
	# 0x200 means inlined, 0x100 means not block aligned, 0x1 means
	# the last extent.
	if ! grep -q "0x301" $tmp.fiemap; then
		rm -f -- $tmp.fiemap
		_notrun "No inline extent creation support, maybe subpage?"
	fi
	rm -f -- $tmp.fiemap
}

_btrfs_metadump()
{
	local device="$1"
	local dumpfile="$2"

	test -n "$BTRFS_IMAGE_PROG" || _fail "btrfs-image not installed"
	$BTRFS_IMAGE_PROG "$device" "$dumpfile"
	[ -n "$DUMP_COMPRESSOR" ] && $DUMP_COMPRESSOR -f "$dumpfile" &> /dev/null
}

# Return the btrfs logical address for the first block in a file
_btrfs_get_first_logical()
{
	local file=$1
	_require_command "$FILEFRAG_PROG" filefrag

	${FILEFRAG_PROG} -v $file >> $seqres.full
	${FILEFRAG_PROG} -v $file | _filter_filefrag | cut -d '#' -f 1
}

# Find the device path for a btrfs logical offset
_btrfs_get_device_path()
{
	local logical=$1
	local stripe=$2

	_require_command "$BTRFS_MAP_LOGICAL_PROG" btrfs-map-logical

	$BTRFS_MAP_LOGICAL_PROG -l $logical $SCRATCH_DEV | \
		$AWK_PROG "(\$1 ~ /mirror/ && \$2 ~ /$stripe/) { print \$8 }"
}


# Find the device physical sector for a btrfs logical offset
_btrfs_get_physical()
{
	local logical=$1
	local stripe=$2

	_require_command "$BTRFS_MAP_LOGICAL_PROG" btrfs-map-logical

	$BTRFS_MAP_LOGICAL_PROG -l $logical $SCRATCH_DEV >> $seqres.full 2>&1
	$BTRFS_MAP_LOGICAL_PROG -l $logical $SCRATCH_DEV | \
		$AWK_PROG "(\$1 ~ /mirror/ && \$2 ~ /$stripe/) { print \$6 }"
}

# Read from a specific stripe to test read recovery that corrupted a specific
# stripe.  Btrfs uses the PID to select the mirror, so keep reading until the
# xfs_io process that performed the read was executed with a PID that ends up
# on the intended mirror.
_btrfs_direct_read_on_mirror()
{
	local mirror=$1
	local nr_mirrors=$2
	local file=$3
	local offset=$4
	local size=$5

	while [[ -z $( (( BASHPID % nr_mirrors == mirror )) &&
		exec $XFS_IO_PROG -d \
			-c "pread -b $size $offset $size" $file) ]]; do
		:
	done
}

# Read from a specific stripe to test read recovery that corrupted a specific
# stripe.  Btrfs uses the PID to select the mirror, so keep reading until the
# xfs_io process that performed the read was executed with a PID that ends up
# on the intended mirror.
_btrfs_buffered_read_on_mirror()
{
	local mirror=$1
	local nr_mirrors=$2
	local file=$3
	local offset=$4
	local size=$5

	# The drop_caches doesn't seem to drop every pages on aarch64 with
	# 64K page size.
	# So here as another workaround, cycle mount the SCRATCH_MNT to ensure
	# the cache are dropped, but we can not use _scratch_cycle_mount, as
	# we may mount whatever dm device at SCRATCH_MNT.
	# So here we grab the mounted block device and its mount options, then
	# unmount and re-mount with the same device and options.
	local dev=$(findmnt -n -T $SCRATCH_MNT -o SOURCE)
	local opts=$(findmnt -n -T $SCRATCH_MNT -o OPTIONS)
	if [ -z "$dev" -o -z "$opts" ]; then
		_fail "failed to grab mount info of $SCRATCH_MNT"
	fi
	_scratch_unmount
	_mount $dev -o $opts $SCRATCH_MNT
	while [[ -z $( (( BASHPID % nr_mirrors == mirror )) &&
		exec $XFS_IO_PROG \
			-c "pread -b $size $offset $size" $file) ]]; do
		:
	done
}

_require_btrfs_corrupt_block()
{
	# An optional arg1 argument to also check the option.
	local opt=$1

	_require_command "$BTRFS_CORRUPT_BLOCK_PROG" btrfs-corrupt-block

	if [ -z "$opt" ]; then
		return
	fi

	$BTRFS_CORRUPT_BLOCK_PROG -h 2>&1 | grep -wq -- "--$opt"
	if [ $? != 0 ]; then
		_notrun "Require $BTRFS_CORRUPT_BLOCK_PROG option --$opt"
	fi
}

_require_btrfs_send_version()
{
	local version=$1

	# Check first if btrfs-progs supports the v2 stream.
	_require_btrfs_command send --compressed-data

	# Now check the kernel support. If send_stream_version does not exists,
	# then it's a kernel that only supports v1.
	[ -f /sys/fs/btrfs/features/send_stream_version ] || \
		_notrun "kernel does not support send stream $version"

	[ $(cat /sys/fs/btrfs/features/send_stream_version) -ge $version ] || \
		_notrun "kernel does not support send stream $version"
}

# Get the bytenr associated to a file extent item at a given file offset.
#
# NOTE: At the moment this only works if the file is on a filesystem on top of
#       the scratch device and the file is in the default subvolume (tree id 5).
_btrfs_get_file_extent_item_bytenr()
{
	local file="$1"
	local offset="$2"
	local ino=$(stat -c "%i" "$file")
	local file_extent_key="($ino EXTENT_DATA $offset)"

	_require_btrfs_command inspect-internal dump-tree

	# The tree dump command below works on committed roots, by reading from
	# a device directly, so we have to sync the filesystem to commit any
	# open transaction.
	$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT

	$BTRFS_UTIL_PROG inspect-internal dump-tree -t 5 $SCRATCH_DEV | \
		grep -A4 "$file_extent_key" | grep "disk byte" | \
		$AWK_PROG '{ print $5 }'
}

# Check that btrfs-progs has support for the logical-resolve command, with the
# -o option, and that the kernel supports the logical to ino ioctl v2 (which
# adds the ignore offset parameter).
_require_btrfs_scratch_logical_resolve_v2()
{
	local bytenr

	# First check if we have support for calling the v2 logical resolve
	# ioctl in btrfs-progs. Check if the -o options exists, which makes
	# btrfs-progs call v2 of the ioctl (because the flag
	# BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET is only supported in v2).
	_require_btrfs_command inspect-internal logical-resolve -o
	_require_scratch

	_scratch_mkfs > /dev/null || \
		_fail "_require_btrfs_scratch_logical_resolve_v2: mkfs failed"
	_scratch_mount

	$XFS_IO_PROG -f -c "pwrite -q 0 128K" "$SCRATCH_MNT/file1"
	bytenr=$(_btrfs_get_file_extent_item_bytenr "$SCRATCH_MNT/file1" 0)
	$BTRFS_UTIL_PROG inspect-internal logical-resolve -o $bytenr \
			 $SCRATCH_MNT > /dev/null
	if [ $? -ne 0 ]; then
		_scratch_unmount
		_notrun "Logical resolve ioctl v2 not supported in the kernel"
	fi
	_scratch_unmount
}

_qgroup_mode()
{
	local dev=$1

	if [ ! -b "$dev" ]; then
		_fail "Usage: _qgroup_mode <mounted_device>"
	fi

	if _has_fs_sysfs_attr $dev /qgroups/mode; then
		_get_fs_sysfs_attr $dev qgroups/mode
	else
		echo "qgroup"
	fi
}

_check_regular_qgroup()
{
	_qgroup_mode "$@" | grep -q 'qgroup'
}

_qgroup_rescan()
{
	local mnt=$1
	local dev=$(findmnt -n -o SOURCE $mnt)

	_check_regular_qgroup $dev || return 1
	_btrfs quota rescan -w $mnt
}

_require_qgroup_rescan()
{
	_scratch_mkfs >>$seqres.full 2>&1
	_scratch_mount
	_btrfs quota enable $SCRATCH_MNT
	# Wait for the first rescan.
	$BTRFS_UTIL_PROG quota rescan -W $SCRATCH_MNT || \
				_notrun "not able to wait on a quota rescan"
	# Make sure we can start a rescan.
	$BTRFS_UTIL_PROG quota rescan -w $SCRATCH_MNT >> $seqres.full || \
					_notrun "not able to run quota rescan"
	_scratch_unmount
}

_require_scratch_qgroup()
{
	_scratch_mkfs >>$seqres.full 2>&1
	_scratch_mount
	$BTRFS_UTIL_PROG quota enable $SCRATCH_MNT
	_check_regular_qgroup $SCRATCH_DEV || \
					_notrun "not running normal qgroups"
	_scratch_unmount
}

_require_scratch_enable_simple_quota()
{
	_scratch_mkfs >>$seqres.full 2>&1
	_scratch_mount
	_qgroup_mode $SCRATCH_DEV | grep 'squota' && \
			_notrun "cannot enable simple quota; on by default"
	$BTRFS_UTIL_PROG quota enable --simple $SCRATCH_MNT || \
					_notrun "simple quotas not available"
	_scratch_unmount
}

_has_btrfs_sysfs_feature_attr()
{
	local feature_attr=$1

	[ -z $feature_attr ] && \
		_fail "Missing feature name argument for _has_btrfs_sysfs_attr"

	modprobe btrfs &> /dev/null

	test -e /sys/fs/btrfs/features/$feature_attr
}

# Print the fsid and metadata uuid replaced with constant strings FSID and
# METADATA_UUID. Compare temp_fsid with fsid and metadata_uuid, then echo what
# it matches to or TEMP_FSID. This helps in comparing with the golden output.
check_fsid()
{
	local dev1=$1
	local fsid
	local metadata_uuid

	_require_btrfs_fs_sysfs
	_require_btrfs_fs_feature temp_fsid
	_require_btrfs_fs_feature metadata_uuid
	_require_btrfs_command inspect-internal dump-super

	# on disk fsid
	fsid=$($BTRFS_UTIL_PROG inspect-internal dump-super $dev1 | \
				grep ^fsid | $AWK_PROG -d" " '{print $2}')
	echo -e "On disk fsid:\t\t$fsid" | sed -e "s/$fsid/FSID/g"

	# Print FSID even if it is not the same as metadata_uuid because it has
	# to match in the golden output.
	metadata_uuid=$(cat /sys/fs/btrfs/$fsid/metadata_uuid)
	echo -e "Metadata uuid:\t\tFSID"

	# This returns the temp_fsid if set
	tempfsid=$(_btrfs_get_fsid $dev1)
	if [[ $tempfsid == $fsid ]]; then
		echo -e "Temp fsid:\t\tFSID"
	elif [[ $tempfsid == $metadata_uuid ]]; then
		# If we are here, it means there is a bug; let it not match with
		# the golden output.
		echo -e "Temp fsid:\t\t$metadata_uuid"
	else
		echo -e "Temp fsid:\t\tTEMPFSID"
	fi

	echo -e -n "Tempfsid status:\t"
	cat /sys/fs/btrfs/$tempfsid/temp_fsid
}

mkfs_clone()
{
	local fsid
	local uuid
	local dev1=$1
	local dev2=$2

	_require_btrfs_command inspect-internal dump-super
	_require_btrfs_mkfs_uuid_option

	[[ -z $dev1 || -z $dev2 ]] && \
		_fail "mkfs_clone requires two devices as arguments"

	_mkfs_dev -fq $dev1

	fsid=$($BTRFS_UTIL_PROG inspect-internal dump-super $dev1 | \
					grep -E ^fsid | $AWK_PROG '{print $2}')
	uuid=$($BTRFS_UTIL_PROG inspect-internal dump-super $dev1 | \
				grep -E ^dev_item.uuid | $AWK_PROG '{print $2}')

	_mkfs_dev -fq --uuid $fsid --device-uuid $uuid $dev2
}

_check_btrfs_raid_type()
{
	_btrfs_get_profile_configs
	if [[ ! "${_btrfs_profile_configs[@]}" =~ "$1" ]]; then
		return 1
	fi
	return 0
}

_require_btrfs_raid_type()
{
	_check_btrfs_raid_type $1 || \
		_notrun "$1 isn't supported by the profile config or scratch device"
}