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lvm2/lib/format1/layout.c
2001-10-25 14:04:18 +00:00

152 lines
3.2 KiB
C

/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
*
* This file is released under the GPL.
*/
#include "disk-rep.h"
#include "log.h"
#include "dbg_malloc.h"
/*
* Only works with powers of 2.
*/
static inline ulong _round_up(ulong n, ulong size)
{
size--;
return (n + size) & ~size;
}
static inline ulong _div_up(ulong n, ulong size)
{
return _round_up(n, size) / size;
}
/*
* Each chunk of metadata should be aligned to
* METADATA_ALIGN.
*/
static uint32_t _next_base(struct data_area *area)
{
return _round_up(area->base + area->size, METADATA_ALIGN);
}
/*
* Quick calculation based on pe_start.
*/
static int _adjust_pe_on_disk(struct pv_disk *pvd)
{
uint32_t pe_start = pvd->pe_start * SECTOR_SIZE;
if (pe_start < pvd->pe_on_disk.base + pvd->pe_on_disk.size)
return 0;
pvd->pe_on_disk.size = pe_start - pvd->pe_on_disk.base;
return 1;
}
static void _calc_simple_layout(struct pv_disk *pvd)
{
pvd->pv_on_disk.base = METADATA_BASE;
pvd->pv_on_disk.size = PV_SIZE;
pvd->vg_on_disk.base = _next_base(&pvd->pv_on_disk);
pvd->vg_on_disk.size = VG_SIZE;
pvd->pv_uuidlist_on_disk.base = _next_base(&pvd->vg_on_disk);
pvd->pv_uuidlist_on_disk.size = MAX_PV * NAME_LEN;
pvd->lv_on_disk.base = _next_base(&pvd->pv_uuidlist_on_disk);
pvd->lv_on_disk.size = MAX_LV * sizeof(struct lv_disk);
pvd->pe_on_disk.base = _next_base(&pvd->lv_on_disk);
pvd->pe_on_disk.size = pvd->pe_total * sizeof(struct pe_disk);
}
int _check_vg_limits(struct disk_list *dl)
{
if (dl->vg.lv_max >= MAX_LV) {
log_error("MaxLogicalVolumes of %d exceeds format limit of %d "
"for VG '%s'", dl->vg.lv_max, MAX_LV - 1,
dl->pv.vg_name);
return 0;
}
if (dl->vg.pv_max >= MAX_PV) {
log_error("MaxPhysicalVolumes of %d exceeds format limit of %d "
"for VG '%s'", dl->vg.pv_max, MAX_PV - 1,
dl->pv.vg_name);
return 0;
}
return 1;
}
/*
* This assumes pe_count and pe_start have already
* been calculated correctly.
*/
int calculate_layout(struct disk_list *dl)
{
struct pv_disk *pvd = &dl->pv;
_calc_simple_layout(pvd);
if (!_adjust_pe_on_disk(pvd)) {
log_error("Insufficient space for metadata and PE's.");
return 0;
}
if (!_check_vg_limits(dl))
return 0;
return 1;
}
/*
* It may seem strange to have a struct
* physical_volume in here, but the number of
* extents that can fit on a disk *is* metadata
* format dependant.
*/
int calculate_extent_count(struct physical_volume *pv)
{
struct pv_disk *pvd = dbg_malloc(sizeof(*pvd));
uint32_t end;
if (!pvd) {
stack;
return 0;
}
/*
* Guess how many extents will fit,
* bearing in mind that one is going to be
* knocked off at the start of the next
* loop.
*/
pvd->pe_total = (pv->size / pv->pe_size);
if (pvd->pe_total < PE_SIZE_PV_SIZE_REL) {
log_error("Insufficient space for extents on %s",
dev_name(pv->dev));
return 0;
}
do {
pvd->pe_total--;
_calc_simple_layout(pvd);
end = ((pvd->pe_on_disk.base + pvd->pe_on_disk.size) /
SECTOR_SIZE);
pvd->pe_start = _round_up(end, PE_ALIGN);
} while((pvd->pe_start + (pvd->pe_total * pv->pe_size)) > pv->size);
pv->pe_count = pvd->pe_total;
pv->pe_start = pvd->pe_start;
dbg_free(pvd);
return 1;
}