cloudstack/scripts/vm/hypervisor/xenserver/xcpserver/nfs.py

137 lines
4.9 KiB
Python
Executable File

#!/usr/bin/python
# Copyright 2012 Citrix Systems, Inc. Licensed under the
# Apache License, Version 2.0 (the "License"); you may not use this
# file except in compliance with the License. Citrix Systems, Inc.
# reserves all rights not expressly granted by the License.
# You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License 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.
#
# Automatically generated by addcopyright.py at 04/03/2012
# nfs.py: NFS related utility functions
import util, errno, os, xml.dom.minidom
# NFS timeout on softmounts is as follows:
# UDP:
# As long as the request wasn't started more than timeo * (2 ^ retrans)
# TCP:
# As long as the request wasn't started more than timeo * (1 + retrans)
# The time when the retrans may retry has been made will be:
# For udp: timeo * (2 ^ retrans * 2 - 1)
# For tcp: timeo * n! where n is the smallest n for which n! > 1 + retrans
# (timeo+timeo).
SOFTMOUNT_TIMEOUT = int((40.0/3.0) * 10.0) # 1/10 s
SOFTMOUNT_RETRANS = 10
RPCINFO_BIN = "/usr/sbin/rpcinfo"
SHOWMOUNT_BIN = "/usr/sbin/showmount"
class NfsException(Exception):
def __init__(self, errstr):
self.errstr = errstr
def check_server_tcp(server):
"""Make sure that NFS over TCP/IP V3 is supported on the server.
Returns True if everything is OK, False otherwise."""
try:
util.ioretry(lambda: util.pread([RPCINFO_BIN,"-t",
"%s" % server, "nfs","3"]),
errlist=[errno.EPERM], maxretry=2, nofail=True)
except util.CommandException, inst:
raise NfsException("rpcinfo failed or timed out: return code %d" %
inst.code)
def soft_mount(mountpoint, remoteserver, remotepath, transport):
"""Mount the remote NFS export at 'mountpoint'"""
try:
if not util.ioretry(lambda: util.isdir(mountpoint)):
util.ioretry(lambda: util.makedirs(mountpoint))
except util.CommandException, inst:
raise NfsException("Failed to make directory: code is %d" %
inst.code)
options = "soft,timeo=%d,retrans=%d,%s,noac" % (SOFTMOUNT_TIMEOUT,
SOFTMOUNT_RETRANS,
transport)
try:
util.ioretry(lambda:
util.pread(["mount.nfs", "%s:%s"
% (remoteserver, remotepath),
mountpoint, "-o", options]),
errlist=[errno.EPIPE, errno.EIO],
maxretry=2, nofail=True)
except util.CommandException, inst:
raise NfsException("mount failed with return code %d" % inst.code)
def unmount(mountpoint, rmmountpoint):
"""Unmount the mounted mountpoint"""
try:
util.pread(["umount", mountpoint])
except util.CommandException, inst:
raise NfsException("umount failed with return code %d" % inst.code)
if rmmountpoint:
try:
os.rmdir(mountpoint)
except OSError, inst:
raise NfsException("rmdir failed with error '%s'" % inst.strerror)
def scan_exports(target):
util.SMlog("scanning")
cmd = [SHOWMOUNT_BIN, "--no-headers", "-e", target]
dom = xml.dom.minidom.Document()
element = dom.createElement("nfs-exports")
dom.appendChild(element)
for val in util.pread2(cmd).split('\n'):
if not len(val):
continue
entry = dom.createElement('Export')
element.appendChild(entry)
subentry = dom.createElement("Target")
entry.appendChild(subentry)
textnode = dom.createTextNode(target)
subentry.appendChild(textnode)
(path, access) = val.split()
subentry = dom.createElement("Path")
entry.appendChild(subentry)
textnode = dom.createTextNode(path)
subentry.appendChild(textnode)
subentry = dom.createElement("Accesslist")
entry.appendChild(subentry)
textnode = dom.createTextNode(access)
subentry.appendChild(textnode)
return dom
def scan_srlist(path):
dom = xml.dom.minidom.Document()
element = dom.createElement("SRlist")
dom.appendChild(element)
for val in filter(util.match_uuid, util.ioretry( \
lambda: util.listdir(path))):
fullpath = os.path.join(path, val)
if not util.ioretry(lambda: util.isdir(fullpath)):
continue
entry = dom.createElement('SR')
element.appendChild(entry)
subentry = dom.createElement("UUID")
entry.appendChild(subentry)
textnode = dom.createTextNode(val)
subentry.appendChild(textnode)
return dom.toprettyxml()