ec2 vbd and NVMe udev rules and helpers

52-ec2-xen-vbd-devices.rules

# ensure any xen virtual block devices named xvdN get a sdN symlink for consistency
KERNEL=="xvd*", PROGRAM="/sbin/ec2udev-vbd %k", SYMLINK+="%c"

70-ec2-nvme-devices.rules

# Copyright (C) 2006-2016 Amazon.com, Inc. or its affiliates.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
#    http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
# OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the
# License.

#nvme-ns-* devices
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{serial}=="?*", ATTRS{model}=="?*", SYMLINK+="disk/by-id/nvme-$attr{model}_$attr{serial}-ns-%n", OPTIONS+="string_escape=replace"

#nvme partitions
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{serial}=="?*", ATTRS{model}=="?*",  IMPORT{program}="ec2nvme-nsid %k"
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{serial}=="?*", ATTRS{model}=="?*",  ENV{_NS_ID}=="?*", SYMLINK+="disk/by-id/nvme-$attr{model}_$attr{serial}-ns-$env{_NS_ID}-part%n", OPTIONS+="string_escape=replace"


# ebs nvme devices
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{model}=="Amazon Elastic Block Store", IMPORT{program}="ec2nvme-id -u %k"
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{model}=="Amazon Elastic Block Store", ENV{_EBS_ALIAS_SD}=="?*", SYMLINK+="$env{_EBS_ALIAS_SD}"
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{model}=="Amazon Elastic Block Store", ENV{_EBS_ALIAS_XVD}=="?*", SYMLINK+="$env{_EBS_ALIAS_XVD}"

# ebs nvme device partitions
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{model}=="Amazon Elastic Block Store", IMPORT{program}="ec2nvme-id -u /dev/%k"
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{model}=="Amazon Elastic Block Store", ENV{_EBS_ALIAS_SD}=="?*", SYMLINK+="$env{_EBS_ALIAS_SD}%n"
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{model}=="Amazon Elastic Block Store", ENV{_EBS_ALIAS_XVD}=="?*", SYMLINK+="$env{_EBS_ALIAS_XVD}%n"


# instance-store nvme devices
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{model}=="Amazon EC2 NVMe Instance Storage", IMPORT{program}="ec2nvme-id -u /dev/%k"
KERNEL=="nvme[0-9]*n[0-9]*", ENV{DEVTYPE}=="disk", ATTRS{model}=="Amazon EC2 NVMe Instance Storage", ENV{_ISTORE_ALIAS}=="?*", SYMLINK+="$env{_ISTORE_ALIAS}"

# instance-store nvme device partitions
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{model}=="Amazon EC2 NVMe Instance Storage", IMPORT{program}="ec2nvme-id -u /dev/%k"
KERNEL=="nvme[0-9]*n[0-9]*p[0-9]*", ENV{DEVTYPE}=="partition", ATTRS{model}=="Amazon EC2 NVMe Instance Storage", ENV{_ISTORE_ALIAS}=="?*", SYMLINK+="$env{_ISTORE_ALIAS}p%n"

ec2nvme-id

#!/usr/bin/env python3

# Copyright (C) 2017 Amazon.com, Inc. or its affiliates.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
#    http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
# OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the
# License.

"""
Usage:
Read EBS device information and provide information about
the volume.

Modified from original Amazon source to support python3 and flesh out
structures in case this becomes useful in other contexts.
"""

import argparse
import sys

from collections import namedtuple
from ctypes import c_uint8, c_uint16, c_uint32, c_uint64, c_char
from ctypes import addressof, sizeof
from ctypes import Structure
from enum import Enum, unique
from fcntl import ioctl
from pathlib import Path


NVME_ADMIN_IDENTIFY = 0x06
NVME_IOCTL_ADMIN_CMD = 0xC0484E41
AMZN_NVME_VID = 0x1D0F
AMZN_NVME_EBS_MN = 'Amazon Elastic Block Store'
AMZN_NVME_ISTORE_MN = 'Amazon EC2 NVMe Instance Storage'
NVME_FILENAME_PATTERN = 'nvme[0-9]*n[0-9]*'
ISTORE_ALIAS_PREFIX = 'ec2_ephemeral_nvme'


# linux/nvme_ioctl.h
class NvmePassthruCmd(Structure):
    _pack_ = 1
    _fields_ = [
        ('opcode', c_uint8),
        ('flags', c_uint8),
        ('rsvd1', c_uint16),
        ('nsid', c_uint32),
        ('cdw2', c_uint32),
        ('cdw3', c_uint32),
        ('metadata', c_uint64),
        ('addr', c_uint64),
        ('metadata_len', c_uint32),
        ('data_len', c_uint32),
        ('cdw10', c_uint32),
        ('cdw11', c_uint32),
        ('cdw12', c_uint32),
        ('cdw13', c_uint32),
        ('cdw14', c_uint32),
        ('cdw15', c_uint32),
        ('timeout_ms', c_uint32),
        ('result', c_uint32),
    ]


# /usr/src/<linux headers>/linux/nvme.h
class NvmeIdPowerState(Structure):
    _pack_ = 1
    _fields_ = [
        ('max_power', c_uint16),
        ('rsvd2', c_uint8),
        ('flags', c_uint8),
        ('entry_lat', c_uint32),
        ('exit_lat', c_uint32),
        ('read_tput', c_uint8),
        ('read_lat', c_uint8),
        ('write_tput', c_uint8),
        ('write_lat', c_uint8),
        ('idle_power', c_uint16),
        ('idle_scale', c_uint8),
        ('rsvd19', c_uint8),
        ('active_power', c_uint16),
        ('active_work_scale', c_uint8),
        ('rsvd23', c_uint8 * 9),
    ]


class NvmeIdVsAmzn(Structure):
    _pack_ = 1
    _fields_ = [
        ('bdev', c_char * 32),  # block device name
        ('reserved0', c_char * (1024 - 32)),
    ]


# /usr/src/<linux headers>/linux/nvme.h
class NvmeIdCtrl(Structure):
    _pack_ = 1
    _fields_ = [
        ('vid', c_uint16),
        ('ssvid', c_uint16),
        ('sn', c_char * 20),
        ('mn', c_char * 40),
        ('fr', c_char * 8),
        ('rab', c_uint8),
        ('ieee', c_uint8 * 3),
        ('cmic', c_uint8),
        ('mdts', c_uint8),
        ('cntlid', c_uint16),
        ('ver', c_uint32),
        ('rtd3r', c_uint32),
        ('rtd3e', c_uint32),
        ('oaes', c_uint32),
        ('ctratt', c_uint32),
        ('rsvd100', c_uint8 * 156),
        ('oacs', c_uint16),
        ('acl', c_uint8),
        ('aerl', c_uint8),
        ('frmw', c_uint8),
        ('lpa', c_uint8),
        ('elpe', c_uint8),
        ('npss', c_uint8),
        ('avscc', c_uint8),
        ('apsta', c_uint8),
        ('wctemp', c_uint16),
        ('cctemp', c_uint16),
        ('mtfa', c_uint16),
        ('hmpre', c_uint32),
        ('hmmin', c_uint32),
        ('tnvmcap', c_uint8 * 16),
        ('unvmcap', c_uint8 * 16),
        ('rpmbs', c_uint32),
        ('edstt', c_uint16),
        ('dsto', c_uint8),
        ('fwug', c_uint8),
        ('kas', c_uint16),
        ('hctma', c_uint16),
        ('mntmt', c_uint16),
        ('mxtmt', c_uint16),
        ('sanicap', c_uint32),
        ('hmminds', c_uint32),
        ('hmmaxd', c_uint16),
        ('rsvd338', c_uint8 * 174),
        ('sqes', c_uint8),
        ('cqes', c_uint8),
        ('maxcmd', c_uint16),
        ('nn', c_uint32),
        ('oncs', c_uint16),
        ('fuses', c_uint16),
        ('fna', c_uint8),
        ('vwc', c_uint8),
        ('awun', c_uint16),
        ('awupf', c_uint16),
        ('nvscc', c_uint8),
        ('rsvd531', c_uint8),
        ('acwu', c_uint16),
        ('rsvd534', c_uint8 * 2),
        ('sgls', c_uint32),
        ('rsvd540', c_uint8 * 228),
        ('subnqn', c_char * 256),
        ('rsvd1024', c_uint8 * 768),
        ('ioccsz', c_uint32),
        ('iorcsz', c_uint32),
        ('icdoff', c_uint16),
        ('ctrattr', c_uint8),
        ('msdbd', c_uint8),
        ('rsvd1804', c_uint8 * 244),
        ('psd', NvmeIdPowerState * 32),
        ('vs', NvmeIdVsAmzn),
    ]


def nvme_id_ctrl(device):
    id_ctrl = NvmeIdCtrl()
    id_ctrl_addr = addressof(id_ctrl)
    id_ctrl_len = sizeof(id_ctrl)
    command = NvmePassthruCmd(
        opcode=NVME_ADMIN_IDENTIFY,
        addr=id_ctrl_addr,
        data_len=id_ctrl_len,
        cdw10=1
    )
    with device.open('r+b') as blockdev:
        ioctl(blockdev, NVME_IOCTL_ADMIN_CMD, command)
    return id_ctrl


@unique
class Ec2NvmeDeviceType(Enum):
    instance_store = 1
    ebs = 2
    invalid = -1


Ec2NvmeEbsAliases = namedtuple('Ec2NvmeEbsAliases', ['sd', 'xvd'])


class NvmeDevice:
    def __init__(self, device):
        self._controller = None
        self._device = Path(device)
        self._model = None
        self._vendor_id = None
        self._serial_number = None
        self._kind = None
        self._volume_id = None
        self._ebs_block_device = None
        self._instance_store_alias = None
        self._udev_aliases = None

    @property
    def device(self):
        return str(self._device)

    @property
    def path(self):
        return self._device

    @property
    def controller(self):
        if self._controller is None:
            self._controller = nvme_id_ctrl(self.path)
        return self._controller

    @property
    def model(self):
        if self._model is None:
            self._model = self.controller.mn.decode().strip()
        return self._model

    @property
    def vendor_id(self):
        if self._vendor_id is None:
            self._vendor_id = self.controller.vid
        return self._vendor_id

    @property
    def serial_number(self):
        if self._serial_number is None:
            self._serial_number = self.controller.sn.decode().strip()
        return self._serial_number

    @property
    def kind(self):
        if self._kind is None:
            kind = Ec2NvmeDeviceType.invalid
            if self.vendor_id == AMZN_NVME_VID:
                if self.model == AMZN_NVME_EBS_MN:
                    kind = Ec2NvmeDeviceType.ebs
                elif self.model == AMZN_NVME_ISTORE_MN:
                    kind = Ec2NvmeDeviceType.instance_store
            self._kind = kind
        return self._kind

    @property
    def volume_id(self):
        if self.kind is not Ec2NvmeDeviceType.ebs:
            return None
        if self._volume_id is None:
            vol = self.serial_number
            if vol.startswith('vol') and vol[3] != '-':
                vol = 'vol-' + vol[3:]
            self._volume_id = vol
        return self._volume_id

    @property
    def ebs_block_device(self):
        if self.kind is not Ec2NvmeDeviceType.ebs:
            return None
        if self._ebs_block_device is None:
            bdev = Path(self.controller.vs.bdev.decode().strip())
            self._ebs_block_device = bdev.name
        return self._ebs_block_device

    @property
    def instance_store_alias(self):
        # For instance-store devices, nvmeXn1 -> {ISTORE_ALIAS_PREFIX}X
        if self.kind is not Ec2NvmeDeviceType.instance_store:
            return None
        if self._instance_store_alias is None:
            devname = self.path.name
            devnum = devname[4]
            self._instance_store_alias = [ISTORE_ALIAS_PREFIX + devnum]
        return self._instance_store_alias

    @property
    def udev_aliases(self):
        if self._udev_aliases is None:
            if self.kind is Ec2NvmeDeviceType.instance_store:
                self._udev_aliases = self.instance_store_alias
            elif self.kind is Ec2NvmeDeviceType.ebs:
                if self.ebs_block_device.startswith('xvd'):
                    self._udev_aliases = Ec2NvmeEbsAliases(
                        xvd=self.ebs_block_device.replace('xvd', 'sd', 1),
                        sd=self.ebs_block_device
                    )
                elif self.ebs_block_device.startswith('sd'):
                    self._udev_aliases = Ec2NvmeEbsAliases(
                        sd=self.ebs_block_device,
                        xvd=self.ebs_block_device.replace('sd', 'xvd', 1)
                    )
                else:
                    return None
            else:
                return None
        return self._udev_aliases

    @property
    def block_device_aliases(self):
        return (None if self.udev_aliases is None
                else ['/dev/' + dev for dev in self.udev_aliases])


def handle_args():
    parser = argparse.ArgumentParser(
        description='Reads EBS or instance-store information from NVMe devices.')
    parser.add_argument('device', type=Path, help='Device to query')

    display = parser.add_argument_group(
        title='Output Options',
        description=('Options may not be combined. '
                     'Default is to return both volume and block device'))
    dgrp = display.add_mutually_exclusive_group()
    dgrp.add_argument('-v', '--volume', action='store_true',
                      help='Return volume-id')
    dgrp.add_argument('-b', '--block-dev-aliases', action='store_true',
                      help='Return block device aliases')
    dgrp.add_argument('-u', '--udev', action='store_true',
                      help='Output block device aliases in format suitable for udev rules')

    args = parser.parse_args()

    if args.device.parent != Path('/dev/'):
        args.device = Path('/dev', args.device)
    device = args.device
    devstr = str(device)

    if not device.exists():
        err = "No such file or directory: '{}'"
        print(err.format(devstr), file=sys.stderr)
        return None

    if not device.is_block_device():
        err = "Provided device is not a block device: '{}'"
        print(err.format(devstr), file=sys.stderr)
        return None

    if not device.resolve().match(NVME_FILENAME_PATTERN):
        err = "Device (or symlink target) is not a nvme device: '{}'"
        print(err.format(devstr), file=sys.stderr)
        return None

    return args


def main():
    args = handle_args()
    if args is None:
        sys.exit(1)

    device = NvmeDevice(args.device)
    if device.kind is Ec2NvmeDeviceType.invalid:
        err = "Device is NVMe but is neither EBS nor instance-store: '{}'"
        print(err.format(str(device.path)), file=sys.stderr)
        sys.exit(1)

    show_both = not any([args.volume, args.block_dev_aliases, args.udev])

    if show_both or args.volume:
        volume_id = device.volume_id
        if volume_id is None:
            print('Device {} is instance-store NVMe, '
                  'no volume ID available'.format(str(device.path)))
        else:
            print('Volume ID: {}'.format(volume_id))

    if show_both or args.block_dev_aliases:
        aliases = ' '.join(device.block_device_aliases)
        print('Block Device Aliases: {}'.format(aliases))

    if args.udev:
        if device.kind is Ec2NvmeDeviceType.instance_store:
            dev = device.udev_aliases[0]
            print('_ISTORE_ALIAS={}'.format(dev))
        elif device.kind is Ec2NvmeDeviceType.ebs:
            print('_EBS_ALIAS_SD={}'.format(device.udev_aliases.sd))
            print('_EBS_ALIAS_XVD={}'.format(device.udev_aliases.xvd))


if __name__ == '__main__':
    main()

ec2nvme-nsid

#!/bin/bash

# Copyright (C) 2006-2016 Amazon.com, Inc. or its affiliates.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
#    http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
# OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the
# License.

#Expected input if partition's kernel name like nvme0n1p2
if (( $# == 0 )); then
  exit 1
fi

# extract ns id from partition's kernel name and export it
NSID=$(echo -n "$@" | cut -f 3 -d 'n' | cut -f 1 -d 'p')
echo "_NS_ID=${NSID}"

ec2udev-vbd

#!/bin/bash
# Maintain consistent naming scheme with current EC2 devices

if (( $# != 1 )); then
    echo "$0 <device>" >&2
    exit 1
fi

if [[ $1 =~ xvd[a-z][0-9]? ]]
then
    echo "${1/xvd/sd}"
else
    echo "$1"
fi