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|
#!/bin/bash
# Simple management of null_blk devices, useful for zoned device testing
# Version: 0.1
#
# Commands:
#
# nullb setup
# - load required modules and mount configfs
#
# nullb create [-s size] [-z zonesize]
# - create a new device with given sizes, allocating the first free indes, #
# device is /dev/nullb$index
#
# nullb ls
# nullb list
# - show table of created null_blk devices, size and zone sizes
#
# nullb rm NAME
# nullb delete NAME
# - delete existing null_blk device by name, must match the device node name
# like 'nullb0'
CMD="$1"
DEBUG=false
# Defaults
SIZE='2048'
ZONESIZE='256'
SYSFS='/sys/kernel/config/nullb'
# create
# list
# delete
# setup
function _error() {
echo "ERROR: $@"
exit 1
}
function _warn() {
echo "WARNING: $@"
}
function _msg() {
echo "INFO: $@"
}
function _dbg() {
$DEBUG && echo "DEBUG: $@" > /dev/tty
}
function _check_setup() {
if ! grep -q null_blk /proc/modules; then
_error "module not loaded"
fi
if ! grep -q configfs /proc/filesystems; then
_error "configfs not mounted"
fi
if ! grep -q zoned "$SYSFS/features"; then
_warn "null_blk module does not support zoned devices"
fi
}
function _check_cd() {
if ! [ -d "$1" ]; then
_error "$1 not accessible"
fi
cd "$1"
}
function _find_free_index() {
_check_cd "$SYSFS"
found=-1
for index in `seq 0 1 10`; do
_dbg "index $index"
ok=true
for dir in $(ls -df1 * 2>/dev/null); do
if ! [ -d "$dir" ]; then
continue
fi
_dbg "found $dir"
idx=$(cat "$dir/index")
if [ "$idx" = "$index" ]; then
ok=false
break
fi
done
if $ok; then
found=$index
break
fi
done
if [ "$found" = "-1" ]; then
_error "no free index found"
fi
_dbg "first free index: $found"
echo -n "$found"
}
function _parse_device_size() {
local size="$SIZE"
_dbg "parse size $@"
while [ $# -gt 0 ]; do
_dbg "ARG: $1"
if [ "$1" = '-s' ]; then
size="$2"
if [ -z "$size" ]; then
_error "-s requires size"
fi
shift
fi
shift
done
echo -en "$size"
}
function _parse_zone_size() {
local zonesize="$ZONESIZE"
_dbg "parse zone size $@"
while [ $# -gt 0 ]; do
_dbg "ARG: $1"
if [ "$1" = '-z' ]; then
zonesize="$2"
if [ -z "$size" ]; then
_error "-z requires size"
fi
shift
fi
shift
done
echo -en "$zonesize"
}
# main()
if [ "$CMD" = 'setup' ]; then
_msg "setup module and mounts"
modprobe configfs
modprobe null_blk nr_devices=0
_check_setup
fi
if [ "$CMD" = 'create' ]; then
_check_setup
index=$(_find_free_index)
name="nullb$index"
# size in MB
size=$(_parse_device_size "$@")
# size in MB
zonesize=$(_parse_zone_size "$@")
_msg "Create nullb$index"
_check_cd "$SYSFS"
if mkdir "$name"; then
_check_cd "$name"
echo "$size" > size
echo 1 > zoned
echo 1 > memory_backed
echo "$zonesize" > zone_size
echo 1 > power
node=$(cat "$SYSFS/$name/index")
node="nullb${node}"
_msg "name=$node"
_msg "size=${size}M zone_size=${zonesize}M"
# last printed line is the exact name for later use
echo "/dev/$node"
else
_error "already exists"
fi
fi
if [ "$CMD" = 'ls' -o "$CMD" = 'list' ]; then
_msg "device nodes:"
ls /dev/nullb* 2>/dev/null
_msg "created devices:"
_check_cd "$SYSFS"
printf '%-2s %-8s %-16s %11s %11s %-2s
' \
"No" \
"Name" \
"Device" \
"Size" \
"Zone size" \
"On"
for dir in $(ls -df1 * 2>/dev/null); do
[ -d "$dir" ] || continue
printf '%2d %-8s %-16s %10dM %10dM %2d
' \
$(cat "$dir/index") \
"$dir" \
"/dev/nullb"$(cat "$dir/index") \
$(cat "$dir/size") \
$(cat "$dir/zone_size") \
$(cat "$dir/power")
done
fi
if [ "$CMD" = 'rm' -o "$CMD" = 'delete' ]; then
_check_cd "$SYSFS"
name="$2"
_dbg "deleting $name"
if [ -d "$name" ]; then
_msg "check mounts"
mount | grep -- "$name"
_msg "removing $name"
rmdir -- "$SYSFS/$name"
else
_error "no such device name: $name"
fi
fi
|
