1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-06 10:00:40 +03:00
lvm2/lib/filters/filter-mpath.c
David Teigland 9048565093 devices: rework libudev usage
related to config settings:
  obtain_device_info_from_udev (controls if lvm gets
    a list of devices from readdir /dev or from libudev)
  external_device_info_source (controls if lvm asks
    libudev for device information)

. Make the obtain_device_list_from_udev setting
  affect only the choice of readdir /dev vs libudev.
  The setting no longer controls if udev is used for
  device type checks.

. Change obtain_device_list_from_udev default to 0.
  This helps avoid boot timeouts due to slow libudev
  queries, avoids reported failures from
  udev_enumerate_scan_devices, and avoids delays from
  "device not initialized in udev database" errors.
  Even without errors, for a system booting with 1024 PVs,
  lvm2-pvscan times improve from about 100 sec to 15 sec,
  and the pvscan command from about 64 sec to about 4 sec.

. For external_device_info_source="none", remove all
  libudev device info queries, and use only lvm
  native device info.

. For external_device_info_source="udev", first check
  lvm native device info, then check libudev info.

. Remove sleep/retry loop when attempting libudev
  queries for device info.  udev info will simply
  be skipped if it's not immediately available.

. Only set up a libdev connection if it will be used by
  obtain_device_list_from_udev/external_device_info_source.

. For native multipath component detection, use
  /etc/multipath/wwids.  If a device has a wwid
  matching an entry in the wwids file, then it's
  considered a multipath component.  This is
  necessary to natively detect multipath
  components when the mpath device is not set up.
2021-07-13 11:11:23 -05:00

77 lines
1.8 KiB
C

/*
* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "base/memory/zalloc.h"
#include "lib/misc/lib.h"
#include "lib/filters/filter.h"
#include "lib/activate/activate.h"
#include "lib/commands/toolcontext.h"
#ifdef __linux__
#include <dirent.h>
static int _ignore_mpath_component(struct cmd_context *cmd, struct dev_filter *f, struct device *dev, const char *use_filter_name)
{
dev->filtered_flags &= ~DEV_FILTERED_MPATH_COMPONENT;
if (dev_is_mpath_component(cmd, dev)) {
log_debug_devs("%s: Skipping mpath component device", dev_name(dev));
dev->filtered_flags |= DEV_FILTERED_MPATH_COMPONENT;
return 0;
}
return 1;
}
static void _destroy(struct dev_filter *f)
{
if (f->use_count)
log_error(INTERNAL_ERROR "Destroying mpath filter while in use %u times.", f->use_count);
}
struct dev_filter *mpath_filter_create(struct dev_types *dt)
{
struct dev_filter *f;
const char *sysfs_dir = dm_sysfs_dir();
if (!*sysfs_dir) {
log_verbose("No proc filesystem found: skipping multipath filter");
return NULL;
}
if (!(f = zalloc(sizeof(*f)))) {
log_error("mpath filter allocation failed");
return NULL;
}
f->passes_filter = _ignore_mpath_component;
f->destroy = _destroy;
f->use_count = 0;
f->name = "mpath";
log_debug_devs("mpath filter initialised.");
return f;
}
#else
struct dev_filter *mpath_filter_create(struct dev_types *dt)
{
return NULL;
}
#endif