os-brick/os_brick/remotefs/remotefs.py
David Vallee Delisle f240960847 Read mounts from /proc/mounts instead of running mount
When creating multiple concurrent volumes, there's a lock
that prevents mount from returning quickly. Reading /proc/mounts
is way faster.

Change-Id: If31d120955eb216823a55005fdd3d24870aa6b9a
Closes-Bug: #1856889
2019-12-20 10:03:30 -05:00

279 lines
11 KiB
Python

# Copyright (c) 2013 OpenStack Foundation
# 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. 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.
"""Remote filesystem client utilities."""
import hashlib
import os
import re
import tempfile
from oslo_concurrency import processutils
from oslo_log import log as logging
import six
from os_brick import exception
from os_brick import executor
from os_brick.i18n import _
LOG = logging.getLogger(__name__)
class RemoteFsClient(executor.Executor):
def __init__(self, mount_type, root_helper,
execute=None, *args, **kwargs):
super(RemoteFsClient, self).__init__(root_helper, execute=execute,
*args, **kwargs)
mount_type_to_option_prefix = {
'nfs': 'nfs',
'cifs': 'smbfs',
'glusterfs': 'glusterfs',
'vzstorage': 'vzstorage',
'quobyte': 'quobyte',
'scality': 'scality'
}
if mount_type not in mount_type_to_option_prefix:
raise exception.ProtocolNotSupported(protocol=mount_type)
self._mount_type = mount_type
option_prefix = mount_type_to_option_prefix[mount_type]
self._mount_base = kwargs.get(option_prefix + '_mount_point_base')
if not self._mount_base:
raise exception.InvalidParameterValue(
err=_('%s_mount_point_base required') % option_prefix)
self._mount_options = kwargs.get(option_prefix + '_mount_options')
if mount_type == "nfs":
self._check_nfs_options()
def get_mount_base(self):
return self._mount_base
def _get_hash_str(self, base_str):
"""Return a string that represents hash of base_str (hex format)."""
if isinstance(base_str, six.text_type):
base_str = base_str.encode('utf-8')
return hashlib.md5(base_str).hexdigest()
def get_mount_point(self, device_name):
"""Get Mount Point.
:param device_name: example 172.18.194.100:/var/nfs
"""
return os.path.join(self._mount_base,
self._get_hash_str(device_name))
def _read_mounts(self):
"""Returns a dict of mounts and their mountpoint
Format reference:
http://man7.org/linux/man-pages/man5/fstab.5.html
"""
with open("/proc/mounts", "r") as mounts:
# Remove empty lines and split lines by whitespace
lines = [l.split() for l in mounts.read().splitlines()
if l.strip()]
# Return {mountpoint: mountdevice}. Fields 2nd and 1st as per
# http://man7.org/linux/man-pages/man5/fstab.5.html
return {line[1]: line[0] for line in lines if line[0] != '#'}
def mount(self, share, flags=None):
"""Mount given share."""
mount_path = self.get_mount_point(share)
if mount_path in self._read_mounts():
LOG.debug('Already mounted: %s', mount_path)
return
self._execute('mkdir', '-p', mount_path, check_exit_code=0)
if self._mount_type == 'nfs':
self._mount_nfs(share, mount_path, flags)
else:
self._do_mount(self._mount_type, share, mount_path,
self._mount_options, flags)
def _do_mount(self, mount_type, share, mount_path, mount_options=None,
flags=None):
"""Mounts share based on the specified params."""
mnt_cmd = ['mount', '-t', mount_type]
if mount_options is not None:
mnt_cmd.extend(['-o', mount_options])
if flags is not None:
mnt_cmd.extend(flags)
mnt_cmd.extend([share, mount_path])
try:
self._execute(*mnt_cmd, root_helper=self._root_helper,
run_as_root=True, check_exit_code=0)
except processutils.ProcessExecutionError as exc:
if 'already mounted' in exc.stderr:
LOG.debug("Already mounted: %s", share)
# The error message can say "busy or already mounted" when the
# share didn't actually mount, so look for it.
if share in self._read_mounts():
return
LOG.error("Failed to mount %(share)s, reason: %(reason)s",
{'share': share, 'reason': exc.stderr})
raise
def _mount_nfs(self, nfs_share, mount_path, flags=None):
"""Mount nfs share using present mount types."""
mnt_errors = {}
# This loop allows us to first try to mount with NFS 4.1 for pNFS
# support but falls back to mount NFS 4 or NFS 3 if either the client
# or server do not support it.
for mnt_type in sorted(self._nfs_mount_type_opts.keys(), reverse=True):
options = self._nfs_mount_type_opts[mnt_type]
try:
self._do_mount('nfs', nfs_share, mount_path, options, flags)
LOG.debug('Mounted %(sh)s using %(mnt_type)s.',
{'sh': nfs_share, 'mnt_type': mnt_type})
return
except Exception as e:
mnt_errors[mnt_type] = six.text_type(e)
LOG.debug('Failed to do %s mount.', mnt_type)
raise exception.BrickException(_("NFS mount failed for share %(sh)s. "
"Error - %(error)s")
% {'sh': nfs_share,
'error': mnt_errors})
def _check_nfs_options(self):
"""Checks and prepares nfs mount type options."""
self._nfs_mount_type_opts = {'nfs': self._mount_options}
nfs_vers_opt_patterns = ['^nfsvers', '^vers', r'^v[\d]']
for opt in nfs_vers_opt_patterns:
if self._option_exists(self._mount_options, opt):
return
# pNFS requires NFS 4.1. The mount.nfs4 utility does not automatically
# negotiate 4.1 support, we have to ask for it by specifying two
# options: vers=4 and minorversion=1.
pnfs_opts = self._update_option(self._mount_options, 'vers', '4')
pnfs_opts = self._update_option(pnfs_opts, 'minorversion', '1')
self._nfs_mount_type_opts['pnfs'] = pnfs_opts
def _option_exists(self, options, opt_pattern):
"""Checks if the option exists in nfs options and returns position."""
options = [x.strip() for x in options.split(',')] if options else []
pos = 0
for opt in options:
pos = pos + 1
if re.match(opt_pattern, opt, flags=0):
return pos
return 0
def _update_option(self, options, option, value=None):
"""Update option if exists else adds it and returns new options."""
opts = [x.strip() for x in options.split(',')] if options else []
pos = self._option_exists(options, option)
if pos:
opts.pop(pos - 1)
opt = '%s=%s' % (option, value) if value else option
opts.append(opt)
return ",".join(opts) if len(opts) > 1 else opts[0]
class ScalityRemoteFsClient(RemoteFsClient):
def __init__(self, mount_type, root_helper,
execute=None, *args, **kwargs):
super(ScalityRemoteFsClient, self).__init__(mount_type, root_helper,
execute=execute,
*args, **kwargs)
self._mount_type = mount_type
self._mount_base = kwargs.get(
'scality_mount_point_base', "").rstrip('/')
if not self._mount_base:
raise exception.InvalidParameterValue(
err=_('scality_mount_point_base required'))
self._mount_options = None
def get_mount_point(self, device_name):
return os.path.join(self._mount_base,
device_name,
"00")
def mount(self, share, flags=None):
"""Mount the Scality ScaleOut FS.
The `share` argument is ignored because you can't mount several
SOFS at the same type on a single server. But we want to keep the
same method signature for class inheritance purpose.
"""
if self._mount_base in self._read_mounts():
LOG.debug('Already mounted: %s', self._mount_base)
return
self._execute('mkdir', '-p', self._mount_base, check_exit_code=0)
super(ScalityRemoteFsClient, self)._do_mount(
'sofs', '/etc/sfused.conf', self._mount_base)
class VZStorageRemoteFSClient(RemoteFsClient):
def _vzstorage_write_mds_list(self, cluster_name, mdss):
tmp_dir = tempfile.mkdtemp(prefix='vzstorage-')
tmp_bs_path = os.path.join(tmp_dir, 'bs_list')
with open(tmp_bs_path, 'w') as f:
for mds in mdss:
f.write(mds + "\n")
conf_dir = os.path.join('/etc/pstorage/clusters', cluster_name)
if os.path.exists(conf_dir):
bs_path = os.path.join(conf_dir, 'bs_list')
self._execute('cp', '-f', tmp_bs_path, bs_path,
root_helper=self._root_helper, run_as_root=True)
else:
self._execute('cp', '-rf', tmp_dir, conf_dir,
root_helper=self._root_helper, run_as_root=True)
self._execute('chown', '-R', 'root:root', conf_dir,
root_helper=self._root_helper, run_as_root=True)
def _do_mount(self, mount_type, vz_share, mount_path,
mount_options=None, flags=None):
m = re.search(r"(?:(\S+):\/)?([a-zA-Z0-9_-]+)(?::(\S+))?", vz_share)
if not m:
msg = (_("Invalid Virtuozzo Storage share specification: %r."
"Must be: [MDS1[,MDS2],...:/]<CLUSTER NAME>[:PASSWORD].")
% vz_share)
raise exception.BrickException(msg)
mdss = m.group(1)
cluster_name = m.group(2)
passwd = m.group(3)
if mdss:
mdss = mdss.split(',')
self._vzstorage_write_mds_list(cluster_name, mdss)
if passwd:
self._execute('pstorage', '-c', cluster_name, 'auth-node', '-P',
process_input=passwd,
root_helper=self._root_helper, run_as_root=True)
mnt_cmd = ['pstorage-mount', '-c', cluster_name]
if flags:
mnt_cmd.extend(flags)
mnt_cmd.extend([mount_path])
self._execute(*mnt_cmd, root_helper=self._root_helper,
run_as_root=True, check_exit_code=0)