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lvm2/lib/filters/filter-composite.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

102 lines
2.7 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2013 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/device/device.h"
static int _and_p(struct cmd_context *cmd, struct dev_filter *f, struct device *dev, const char *use_filter_name)
{
struct dev_filter **filters;
int ret = 1;
dev_ext_enable(dev, external_device_info_source());
for (filters = (struct dev_filter **) f->private; *filters; ++filters) {
if (use_filter_name && strcmp((*filters)->name, use_filter_name))
continue;
ret = (*filters)->passes_filter(cmd, *filters, dev, use_filter_name);
if (!ret) {
ret = 0; /* No 'stack': a filter, not an error. */
break;
}
}
dev_ext_disable(dev);
return ret;
}
static void _composite_destroy(struct dev_filter *f)
{
struct dev_filter **filters;
if (f->use_count)
log_error(INTERNAL_ERROR "Destroying composite filter while in use %u times.", f->use_count);
for (filters = (struct dev_filter **) f->private; *filters; ++filters)
(*filters)->destroy(*filters);
free(f->private);
free(f);
}
static void _wipe(struct cmd_context *cmd, struct dev_filter *f, struct device *dev, const char *use_filter_name)
{
struct dev_filter **filters;
for (filters = (struct dev_filter **) f->private; *filters; ++filters) {
if (use_filter_name && strcmp((*filters)->name, use_filter_name))
continue;
if ((*filters)->wipe)
(*filters)->wipe(cmd, *filters, dev, use_filter_name);
}
}
struct dev_filter *composite_filter_create(int n, struct dev_filter **filters)
{
struct dev_filter **filters_copy, *cft;
if (!filters)
return_NULL;
if (!(filters_copy = malloc(sizeof(*filters) * (n + 1)))) {
log_error("Composite filters allocation failed.");
return NULL;
}
memcpy(filters_copy, filters, sizeof(*filters) * n);
filters_copy[n] = NULL;
if (!(cft = zalloc(sizeof(*cft)))) {
log_error("Composite filters allocation failed.");
free(filters_copy);
return NULL;
}
cft->passes_filter = _and_p;
cft->destroy = _composite_destroy;
cft->wipe = _wipe;
cft->use_count = 0;
cft->private = filters_copy;
cft->name = "composite";
log_debug_devs("Composite filter initialised.");
return cft;
}