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lvm2/lib/device/dev-type.h
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

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3.8 KiB
C

/*
* Copyright (C) 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
*/
#ifndef _LVM_DEV_TYPE_H
#define _LVM_DEV_TYPE_H
#include "lib/device/device.h"
#include "lib/display/display.h"
#include "lib/label/label.h"
#define NUMBER_OF_MAJORS 4096
#ifdef __linux__
# include "libdm/misc/kdev_t.h"
#else
# define MAJOR(x) major((x))
# define MINOR(x) minor((x))
# define MKDEV(x,y) makedev((x),(y))
#endif
#define PARTITION_SCSI_DEVICE (1 << 0)
struct dev_type_def {
int max_partitions; /* 0 means LVM won't use this major number. */
int flags;
};
struct dev_types {
int md_major;
int blkext_major;
int drbd_major;
int device_mapper_major;
int emcpower_major;
int vxdmp_major;
int power2_major;
int dasd_major;
int loop_major;
struct dev_type_def dev_type_array[NUMBER_OF_MAJORS];
};
struct dev_types *create_dev_types(const char *proc_dir, const struct dm_config_node *cn);
/* Subsystems */
int dev_subsystem_part_major(struct dev_types *dt, struct device *dev);
const char *dev_subsystem_name(struct dev_types *dt, struct device *dev);
int major_is_scsi_device(struct dev_types *dt, int major);
/* Signature/superblock recognition with position returned where found. */
int dev_is_md_component(struct cmd_context *cmd, struct device *dev, uint64_t *sb, int full);
int dev_is_mpath_component(struct cmd_context *cmd, struct device *dev);
int dev_is_swap(struct cmd_context *cmd, struct device *dev, uint64_t *signature, int full);
int dev_is_luks(struct cmd_context *cmd, struct device *dev, uint64_t *signature, int full);
int dasd_is_cdl_formatted(struct device *dev);
int dev_is_lvm1(struct device *dev, char *buf, int buflen);
int dev_is_pool(struct device *dev, char *buf, int buflen);
/* Signature wiping. */
#define TYPE_LVM1_MEMBER 0x001
#define TYPE_LVM2_MEMBER 0x002
#define TYPE_DM_SNAPSHOT_COW 0x004
int wipe_known_signatures(struct cmd_context *cmd, struct device *dev, const char *name,
uint32_t types_to_exclude, uint32_t types_no_prompt,
int yes, force_t force, int *wiped);
/* Type-specific device properties */
unsigned long dev_md_stripe_width(struct dev_types *dt, struct device *dev);
int dev_is_md_with_end_superblock(struct dev_types *dt, struct device *dev);
/* Partitioning */
int major_max_partitions(struct dev_types *dt, int major);
int dev_is_partitioned(struct cmd_context *cmd, struct device *dev);
int dev_get_primary_dev(struct dev_types *dt, struct device *dev, dev_t *result);
int dev_get_partition_number(struct device *dev, int *num);
/* Various device properties */
unsigned long dev_alignment_offset(struct dev_types *dt, struct device *dev);
unsigned long dev_minimum_io_size(struct dev_types *dt, struct device *dev);
unsigned long dev_optimal_io_size(struct dev_types *dt, struct device *dev);
unsigned long dev_discard_max_bytes(struct dev_types *dt, struct device *dev);
unsigned long dev_discard_granularity(struct dev_types *dt, struct device *dev);
int dev_is_rotational(struct dev_types *dt, struct device *dev);
int dev_is_pmem(struct dev_types *dt, struct device *dev);
int dev_is_nvme(struct dev_types *dt, struct device *dev);
int dev_is_lv(struct device *dev);
int get_fs_block_size(const char *pathname, uint32_t *fs_block_size);
int dev_is_used_by_active_lv(struct cmd_context *cmd, struct device *dev, int *used_by_lv_count,
char **used_by_dm_name, char **used_by_vg_uuid, char **used_by_lv_uuid);
#endif