93 lines
3.1 KiB
Python
93 lines
3.1 KiB
Python
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# udev.py
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# Python module for querying the udev database for device information.
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#
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# Copyright (C) 2009 Red Hat, Inc.
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#
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# This copyrighted material is made available to anyone wishing to use,
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# modify, copy, or redistribute it subject to the terms and conditions of
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# the GNU General Public License v.2, or (at your option) any later version.
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# This program is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY expressed or implied, including the implied warranties of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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# Public License for more details. You should have received a copy of the
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# GNU General Public License along with this program; if not, write to the
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# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
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# source code or documentation are not subject to the GNU General Public
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# License and may only be used or replicated with the express permission of
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# Red Hat, Inc.
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#
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# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
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# Chris Lumens <clumens@redhat.com>
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#
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import iutil
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import os
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import pyudev
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global_udev = pyudev.Udev()
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import logging
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log = logging.getLogger("storage")
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def udev_enumerate_devices(deviceClass="block"):
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devices = global_udev.enumerate_devices(subsystem=deviceClass)
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return [path[4:] for path in devices]
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def udev_get_device(sysfs_path):
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if not os.path.exists("/sys%s" % sysfs_path):
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log.debug("%s does not exist" % sysfs_path)
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return None
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# XXX we remove the /sys part when enumerating devices,
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# so we have to prepend it when creating the device
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dev = global_udev.create_device("/sys" + sysfs_path)
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if dev:
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dev["name"] = dev.sysname
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dev["sysfs_path"] = sysfs_path
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# now add in the contents of the uevent file since they're handy
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dev = udev_parse_uevent_file(dev)
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return dev
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def udev_get_devices(deviceClass="block"):
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udev_settle()
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entries = []
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for path in udev_enumerate_devices(deviceClass):
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entry = udev_get_device(path)
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if entry:
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entries.append(entry)
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return entries
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def udev_parse_uevent_file(dev):
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path = os.path.normpath("/sys/%s/uevent" % dev['sysfs_path'])
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if not os.access(path, os.R_OK):
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return dev
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with open(path) as f:
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for line in f.readlines():
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(key, equals, value) = line.strip().partition("=")
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if not equals:
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continue
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dev[key] = value
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return dev
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def udev_settle():
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# wait maximal 300 seconds for udev to be done running blkid, lvm,
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# mdadm etc. This large timeout is needed when running on machines with
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# lots of disks, or with slow disks
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argv = ["settle", "--timeout=300"]
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iutil.execWithRedirect("udevadm", argv, stderr="/dev/null")
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def udev_trigger(subsystem=None, action="add"):
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argv = ["trigger", "--action=%s" % action]
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if subsystem:
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argv.append("--subsystem-match=%s" % subsystem)
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iutil.execWithRedirect("udevadm", argv, stderr="/dev/null")
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