1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-29 15:22:30 +03:00
lvm2/lib/device/device.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

212 lines
6.9 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2007 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_DEVICE_H
#define _LVM_DEVICE_H
#include "lib/uuid/uuid.h"
#include <fcntl.h>
#define DEV_REGULAR 0x00000002 /* Regular file? */
#define DEV_ALLOCED 0x00000004 /* malloc used */
#define DEV_OPENED_RW 0x00000008 /* Opened RW */
#define DEV_OPENED_EXCL 0x00000010 /* Opened EXCL */
#define DEV_O_DIRECT 0x00000020 /* Use O_DIRECT */
#define DEV_O_DIRECT_TESTED 0x00000040 /* DEV_O_DIRECT is reliable */
#define DEV_OPEN_FAILURE 0x00000080 /* Has last open failed? */
#define DEV_USED_FOR_LV 0x00000100 /* Is device used for an LV */
#define DEV_ASSUMED_FOR_LV 0x00000200 /* Is device assumed for an LV */
#define DEV_NOT_O_NOATIME 0x00000400 /* Don't use O_NOATIME */
#define DEV_IN_BCACHE 0x00000800 /* dev fd is open and used in bcache */
#define DEV_BCACHE_EXCL 0x00001000 /* bcache_fd should be open EXCL */
#define DEV_FILTER_AFTER_SCAN 0x00002000 /* apply filter after bcache has data */
#define DEV_FILTER_OUT_SCAN 0x00004000 /* filtered out during label scan */
#define DEV_BCACHE_WRITE 0x00008000 /* bcache_fd is open with RDWR */
#define DEV_SCAN_FOUND_LABEL 0x00010000 /* label scan read dev and found label */
#define DEV_IS_MD_COMPONENT 0x00020000 /* device is an md component */
#define DEV_IS_NVME 0x00040000 /* set if dev is nvme */
#define DEV_MATCHED_USE_ID 0x00080000 /* matched an entry from cmd->use_devices */
/*
* Support for external device info.
* Any new external device info source needs to be
* registered using EXT_REGISTER macro in dev-ext.c.
*/
typedef enum dev_ext_e {
DEV_EXT_NONE,
DEV_EXT_UDEV,
DEV_EXT_NUM
} dev_ext_t;
struct dev_ext {
int enabled;
dev_ext_t src;
void *handle;
};
#define DEV_ID_TYPE_SYS_WWID 0x0001
#define DEV_ID_TYPE_SYS_SERIAL 0x0002
#define DEV_ID_TYPE_MPATH_UUID 0x0003
#define DEV_ID_TYPE_MD_UUID 0x0004
#define DEV_ID_TYPE_LOOP_FILE 0x0005
#define DEV_ID_TYPE_CRYPT_UUID 0x0006
#define DEV_ID_TYPE_LVMLV_UUID 0x0007
#define DEV_ID_TYPE_DEVNAME 0x0008
/*
* A device ID of a certain type for a device.
* A struct device may have multiple dev_id structs on dev->ids.
* One of them will be the one that's used, pointed to by dev->id.
*/
struct dev_id {
struct dm_list list;
struct device *dev;
uint16_t idtype; /* DEV_ID_TYPE_ */
char *idname; /* id string determined by idtype */
};
/*
* A device listed in devices file that lvm should use.
* Each entry in the devices file is represented by a struct dev_use.
* The structs are kept on cmd->use_devices.
* idtype/idname/pvid/part are set when reading the devices file.
* du->dev is set when a struct dev_use is matched to a struct device.
*/
struct dev_use {
struct dm_list list;
struct device *dev;
int part;
uint16_t idtype;
char *idname;
char *devname;
char *pvid;
};
/*
* All devices in LVM will be represented by one of these.
* pointer comparisons are valid.
*/
struct device {
struct dm_list aliases; /* struct dm_str_list */
struct dm_list ids; /* struct dev_id, different entries for different idtypes */
struct dev_id *id; /* points to the the ids entry being used for this dev */
dev_t dev;
/* private */
int fd;
int open_count;
int physical_block_size; /* From BLKPBSZGET: lowest possible sector size that the hardware can operate on without reverting to read-modify-write operations */
int logical_block_size; /* From BLKSSZGET: lowest possible block size that the storage device can address */
int read_ahead;
int bcache_fd;
int bcache_di;
int part; /* partition number */
uint32_t flags;
uint32_t filtered_flags;
unsigned size_seqno;
uint64_t size;
uint64_t end;
struct dev_ext ext;
const char *duplicate_prefer_reason;
const char *vgid; /* if device is an LV */
const char *lvid; /* if device is an LV */
char pvid[ID_LEN + 1]; /* if device is a PV */
char _padding[7];
};
/*
* All I/O is annotated with the reason it is performed.
*/
typedef enum dev_io_reason {
DEV_IO_SIGNATURES = 0, /* Scanning device signatures */
DEV_IO_LABEL, /* LVM PV disk label */
DEV_IO_MDA_HEADER, /* Text format metadata area header */
DEV_IO_MDA_CONTENT, /* Text format metadata area content */
DEV_IO_MDA_EXTRA_HEADER, /* Header of any extra metadata areas on device */
DEV_IO_MDA_EXTRA_CONTENT, /* Content of any extra metadata areas on device */
DEV_IO_FMT1, /* Original LVM1 metadata format */
DEV_IO_POOL, /* Pool metadata format */
DEV_IO_LV, /* Content written to an LV */
DEV_IO_LOG /* Logging messages */
} dev_io_reason_t;
struct device_list {
struct dm_list list;
struct device *dev;
};
struct device_area {
struct device *dev;
uint64_t start; /* Bytes */
uint64_t size; /* Bytes */
};
/*
* Support for external device info.
*/
const char *dev_ext_name(struct device *dev);
int dev_ext_enable(struct device *dev, dev_ext_t src);
int dev_ext_disable(struct device *dev);
struct dev_ext *dev_ext_get(struct device *dev);
int dev_ext_release(struct device *dev);
/*
* Increment current dev_size_seqno.
* This is used to control lifetime
* of cached device size.
*/
void dev_size_seqno_inc(void);
/*
* All io should use these routines.
*/
int dev_get_direct_block_sizes(struct device *dev, unsigned int *physical_block_size,
unsigned int *logical_block_size);
int dev_get_size(struct device *dev, uint64_t *size);
int dev_get_read_ahead(struct device *dev, uint32_t *read_ahead);
int dev_discard_blocks(struct device *dev, uint64_t offset_bytes, uint64_t size_bytes);
/* Use quiet version if device number could change e.g. when opening LV */
int dev_open(struct device *dev);
int dev_open_quiet(struct device *dev);
int dev_open_flags(struct device *dev, int flags, int direct, int quiet);
int dev_open_readonly(struct device *dev);
int dev_open_readonly_buffered(struct device *dev);
int dev_open_readonly_quiet(struct device *dev);
int dev_close(struct device *dev);
int dev_close_immediate(struct device *dev);
int dev_fd(struct device *dev);
const char *dev_name(const struct device *dev);
void dev_flush(struct device *dev);
struct device *dev_create_file(const char *filename, struct device *dev,
struct dm_str_list *alias, int use_malloc);
void dev_destroy_file(struct device *dev);
/* Return a valid device name from the alias list; NULL otherwise */
const char *dev_name_confirmed(struct device *dev, int quiet);
int dev_mpath_init(const char *config_wwids_file);
void dev_mpath_exit(void);
#endif