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lvm2/lib/metadata/metadata.h
2002-02-21 10:16:33 +00:00

353 lines
8.4 KiB
C

/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
*
* This file is released under the LGPL.
*
* This is the in core representation of a volume group and its
* associated physical and logical volumes.
*/
#ifndef _LVM_METADATA_H
#define _LVM_METADATA_H
#include <sys/types.h>
#include <asm/page.h>
#include "dev-cache.h"
#include "list.h"
#include "uuid.h"
#define NAME_LEN 128
#define MAX_STRIPES 128
#define SECTOR_SIZE 512
#define STRIPE_SIZE_DEFAULT 16 /* 16KB */
#define STRIPE_SIZE_MIN ( PAGE_SIZE/SECTOR_SIZE) /* PAGESIZE in sectors */
#define STRIPE_SIZE_MAX ( 512L * 1024 / SECTOR_SIZE) /* 512 KB in sectors */
#define PV_MIN_SIZE ( 512L * 1024 / SECTOR_SIZE) /* 512 KB in sectors */
/* Various flags */
/* Note that the bits no longer necessarily correspond to LVM1 disk format */
#define EXPORTED_VG 0x00000002 /* VG PV */
#define RESIZEABLE_VG 0x00000004 /* VG */
#define PARTIAL_VG 0x00000040 /* VG */
/* May any free extents on this PV be used or must they be left free? */
#define ALLOCATABLE_PV 0x00000008 /* PV */
#define SPINDOWN_LV 0x00000010 /* LV */
#define BADBLOCK_ON 0x00000020 /* LV */
#define FIXED_MINOR 0x00000080 /* LV */
/* FIXME: do we really set read/write for a whole vg ? */
#define LVM_READ 0x00000100 /* LV VG */
#define LVM_WRITE 0x00000200 /* LV VG */
#define CLUSTERED 0x00000400 /* VG */
#define SHARED 0x00000800 /* VG */
/* FIXME: This should be an enum rather than a bitset,
remove from status - EJT */
#define ALLOC_SIMPLE 0x00001000 /* LV */
#define ALLOC_STRICT 0x00002000 /* LV */
#define ALLOC_CONTIGUOUS 0x00004000 /* LV */
struct physical_volume {
struct id id;
struct device *dev;
char *vg_name;
uint32_t status;
uint64_t size;
/* physical extents */
uint64_t pe_size;
uint64_t pe_start;
uint32_t pe_count;
uint32_t pe_allocated; /* FIXME: change the name to alloc_count ? */
};
struct cmd_context;
struct volume_group {
struct cmd_context *cmd;
struct id id;
char *name;
char *system_id;
uint32_t status;
uint32_t extent_size;
uint32_t extent_count;
uint32_t free_count;
uint32_t max_lv;
uint32_t max_pv;
/* physical volumes */
uint32_t pv_count;
struct list pvs;
/* logical volumes */
uint32_t lv_count;
struct list lvs;
/* snapshots */
uint32_t snapshot_count;
struct list snapshots;
};
struct stripe_segment {
struct list list;
struct logical_volume *lv;
uint32_t le;
uint32_t len;
uint32_t stripe_size;
uint32_t stripes;
/* There will be one area for each stripe */
struct {
struct physical_volume *pv;
uint32_t pe;
} area[0];
};
struct logical_volume {
struct id id;
char *name;
struct volume_group *vg;
uint32_t status;
uint32_t read_ahead;
int32_t minor;
uint64_t size;
uint32_t le_count;
struct list segments;
};
struct snapshot {
int persistent; /* boolean */
uint32_t chunk_size; /* in 512 byte sectors */
struct logical_volume *origin;
struct logical_volume *cow;
};
struct name_list {
struct list list;
char *name;
};
struct pv_list {
struct list list;
struct physical_volume *pv;
};
struct lv_list {
struct list list;
struct logical_volume *lv;
};
struct snapshot_list {
struct list list;
struct snapshot *snapshot;
};
struct format_instance {
struct cmd_context *cmd;
struct format_handler *ops;
void *private;
};
/*
* Ownership of objects passes to caller.
*/
struct format_handler {
/*
* Returns a name_list of vg's.
*/
struct list *(*get_vgs)(struct format_instance *fi);
/*
* Returns pv_list of fully-populated pv structures.
*/
struct list *(*get_pvs)(struct format_instance *fi);
/*
* Return PV with given path.
*/
struct physical_volume *(*pv_read)(struct format_instance *fi,
const char *pv_name);
/*
* Tweak an already filled out a pv ready for importing into a
* vg. eg. pe_count is format specific.
*/
int (*pv_setup)(struct format_instance *fi, struct physical_volume *pv,
struct volume_group *vg);
/*
* Write a PV structure to disk. Fails if the PV is in a VG ie
* pv->vg_name must be null.
*/
int (*pv_write)(struct format_instance *fi,
struct physical_volume *pv);
/*
* Tweak an already filled out a lv eg, check there
* aren't too many extents.
*/
int (*lv_setup)(struct format_instance *fi, struct logical_volume *lv);
/*
* Tweak an already filled out vg. eg, max_pv is format
* specific.
*/
int (*vg_setup)(struct format_instance *fi, struct volume_group *vg);
/*
* The name may be prefixed with the dev_dir from the
* job_context.
*/
struct volume_group *(*vg_read)(struct format_instance *fi,
const char *vg_name);
/*
* Write out complete VG metadata. You must ensure internal
* consistency before calling. eg. PEs can't refer to PVs not
* part of the VG.
*
* It is also the responsibility of the caller to ensure external
* consistency, eg by calling pv_write() if removing PVs from
* a VG or calling vg_write() a second time if splitting a VG
* into two.
*
* vg_write() must not read or write from any PVs not included
* in the volume_group structure it is handed. Note: format1
* does read all pv's currently.
*/
int (*vg_write)(struct format_instance *fi, struct volume_group *vg);
/*
* Destructor for this object.
*/
void (*destroy)(struct format_instance *fi);
};
/*
* Utility functions
*/
struct physical_volume *pv_create(struct format_instance *fi,
const char *name,
struct id *id,
uint64_t size);
struct volume_group *vg_create(struct format_instance *fi, const char *name,
uint32_t extent_size, int max_pv, int max_lv,
int pv_count, char **pv_names);
/*
* This needs the format instance to check the
* pv's are orphaned.
*/
int vg_extend(struct format_instance *fi,
struct volume_group *vg, int pv_count, char **pv_names);
/*
* Create a new LV within a given volume group.
*
*/
struct logical_volume *lv_create(struct format_instance *fi,
const char *name,
uint32_t status,
uint32_t stripes,
uint32_t stripe_size,
uint32_t extents,
struct volume_group *vg,
struct list *acceptable_pvs);
int lv_reduce(struct format_instance *fi,
struct logical_volume *lv, uint32_t extents);
int lv_extend(struct format_instance *fi,
struct logical_volume *lv,
uint32_t stripes,
uint32_t stripe_size,
uint32_t extents,
struct list *allocatable_pvs);
/* lv must be part of vg->lvs */
int lv_remove(struct volume_group *vg, struct logical_volume *lv);
/* FIXME: Move to other files */
int id_eq(struct id *op1, struct id *op2);
/* Manipulate PV structures */
int pv_add(struct volume_group *vg, struct physical_volume *pv);
int pv_remove(struct volume_group *vg, struct physical_volume *pv);
struct physical_volume *pv_find(struct volume_group *vg,
const char *pv_name);
/* Find a PV within a given VG */
struct pv_list *find_pv_in_vg(struct volume_group *vg, const char *pv_name);
/* Find an LV within a given VG */
struct lv_list *find_lv_in_vg(struct volume_group *vg, const char *lv_name);
/* Return the VG that contains a given LV (based on path given in lv_name) */
/* or environment var */
struct volume_group *find_vg_with_lv(const char *lv_name);
/* FIXME Merge these functions with ones above */
struct physical_volume *find_pv(struct volume_group *vg, struct device *dev);
struct logical_volume *find_lv(struct volume_group *vg, const char *lv_name);
/*
* Remove a dev_dir if present.
*/
const char *strip_dir(const char *vg_name, const char *dir);
/*
* Checks that an lv has no gaps or overlapping segments.
*/
int lv_check_segments(struct logical_volume *lv);
/*
* Sometimes (eg, after an lvextend), it is possible to merge two
* adjacent segments into a single segment. This function trys
* to merge as many segments as possible.
*/
int lv_merge_segments(struct logical_volume *lv);
/*
* Useful functions for managing snapshots.
*/
int lv_is_origin(struct logical_volume *lv);
int lv_is_cow(struct logical_volume *lv);
struct snapshot *find_cow(struct volume_group *vg, struct logical_volume *lv);
int vg_add_snapshot(struct volume_group *vg,
struct logical_volume *origin,
struct logical_volume *cow,
int persistent,
uint32_t chunk_size);
int vg_remove_snapshot(struct volume_group *vg, struct logical_volume *cow);
#endif