1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00
lvm2/lib/label/label.h
David Teigland a7cb76ae94 scan: use bcache for label scan and vg read
New label_scan function populates bcache for each device
on the system.

The two read paths are updated to get data from bcache.

The bcache is not yet used for writing.  bcache blocks
for a device are invalidated when the device is written.
2018-04-20 11:19:24 -05:00

113 lines
2.9 KiB
C

/*
* Copyright (C) 2002-2004 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_LABEL_H
#define _LVM_LABEL_H
#include "uuid.h"
#include "device.h"
#include "bcache.h"
#include "toolcontext.h"
#define LABEL_ID "LABELONE"
#define LABEL_SIZE SECTOR_SIZE /* Think very carefully before changing this */
#define LABEL_SCAN_SECTORS 4L
#define LABEL_SCAN_SIZE (LABEL_SCAN_SECTORS << SECTOR_SHIFT)
struct labeller;
void allow_reads_with_lvmetad(void);
/* On disk - 32 bytes */
struct label_header {
int8_t id[8]; /* LABELONE */
uint64_t sector_xl; /* Sector number of this label */
uint32_t crc_xl; /* From next field to end of sector */
uint32_t offset_xl; /* Offset from start of struct to contents */
int8_t type[8]; /* LVM2 001 */
} __attribute__ ((packed));
/* In core */
struct label {
char type[8];
uint64_t sector;
struct labeller *labeller;
struct device *dev;
void *info;
};
struct labeller;
struct label_ops {
/*
* Is the device labelled with this format ?
*/
int (*can_handle) (struct labeller * l, void *buf, uint64_t sector);
/*
* Write a label to a volume.
*/
int (*write) (struct label * label, void *buf);
/*
* Read a label from a volume.
*/
int (*read) (struct labeller * l, struct device * dev,
void *label_buf, struct label ** label);
/*
* Populate label_type etc.
*/
int (*initialise_label) (struct labeller * l, struct label * label);
/*
* Destroy a previously read label.
*/
void (*destroy_label) (struct labeller * l, struct label * label);
/*
* Destructor.
*/
void (*destroy) (struct labeller * l);
};
struct labeller {
struct label_ops *ops;
const struct format_type *fmt;
};
int label_init(void);
void label_exit(void);
int label_register_handler(struct labeller *handler);
struct labeller *label_get_handler(const char *name);
int label_remove(struct device *dev);
int label_write(struct device *dev, struct label *label);
struct label *label_create(struct labeller *labeller);
void label_destroy(struct label *label);
extern struct bcache *scan_bcache;
int label_scan(struct cmd_context *cmd);
int label_scan_devs(struct cmd_context *cmd, struct dm_list *devs);
void label_scan_invalidate(struct device *dev);
void label_scan_destroy(struct cmd_context *cmd);
int label_read(struct device *dev, struct label **labelp, uint64_t unused_sector);
int label_read_sector(struct device *dev, struct label **labelp, uint64_t scan_sector);
#endif