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lvm2/lib/metadata/lv_manip.c
Alasdair Kergon faa556e759 Add internal cache holding a 'hint' list of the PVs belonging to each VG.
A substantial speed-up - particularly in readline mode.
If the hints turn out to be wrong, the relevant parts get thrown away.
vgscan destroys it totally.  In both cases it then rebuilds itself as
required.
2001-12-13 00:07:29 +00:00

517 lines
11 KiB
C

/*
* Copyright (C) 2001 Sistina Software
*
* This file is released under the LGPL.
*/
#include "metadata.h"
#include "pv_map.h"
#include "log.h"
#include "dbg_malloc.h"
#include <assert.h>
/*
* These functions adjust the pe counts in pv's
* after we've added or removed segments.
*/
static void _get_extents(struct stripe_segment *seg)
{
int s, count;
struct physical_volume *pv;
for (s = 0; s < seg->stripes; s++) {
pv = seg->area[s].pv;
count = seg->len / seg->stripes;
pv->pe_allocated += count;
}
}
static void _put_extents(struct stripe_segment *seg)
{
int s, count;
struct physical_volume *pv;
for (s = 0; s < seg->stripes; s++) {
pv = seg->area[s].pv;
count = seg->len / seg->stripes;
assert(pv->pe_allocated >= count);
pv->pe_allocated -= count;
}
}
static struct stripe_segment *_alloc_segment(struct pool *mem, int stripes)
{
struct stripe_segment *seg;
uint32_t len = sizeof(*seg) + (stripes * sizeof(seg->area[0]));
if (!(seg = pool_zalloc(mem, len))) {
stack;
return NULL;
}
return seg;
}
static int _alloc_stripe_area(struct logical_volume *lv, uint32_t stripes,
uint32_t stripe_size,
struct pv_area **areas, uint32_t *index)
{
uint32_t count = lv->le_count - *index;
uint32_t per_area = count / stripes;
uint32_t smallest = areas[stripes - 1]->count;
uint32_t s;
struct stripe_segment *seg;
if (smallest < per_area)
per_area = smallest;
if (!(seg = _alloc_segment(lv->vg->cmd->mem, stripes))) {
log_err("Couldn't allocate new stripe segment.");
return 0;
}
seg->lv = lv;
seg->le = *index;
seg->len = per_area * stripes;
seg->stripes = stripes;
seg->stripe_size = stripe_size;
for (s = 0; s < stripes; s++) {
struct pv_area *pva = areas[s];
seg->area[s].pv = pva->map->pv;
seg->area[s].pe = pva->start;
consume_pv_area(pva, per_area);
}
list_add(&lv->segments, &seg->list);
*index += seg->len;
return 1;
}
static int _comp_area(const void *l, const void *r)
{
struct pv_area *lhs = *((struct pv_area **) l);
struct pv_area *rhs = *((struct pv_area **) r);
if (lhs->count < rhs->count)
return 1;
else if (lhs->count > rhs->count)
return -1;
return 0;
}
static int _alloc_striped(struct logical_volume *lv,
struct list *pvms, uint32_t allocated,
uint32_t stripes, uint32_t stripe_size)
{
int r = 0;
struct list *pvmh;
struct pv_area **areas;
int pv_count = 0, index;
struct pv_map *pvm;
size_t len;
list_iterate (pvmh, pvms)
pv_count++;
/* allocate an array of pv_areas, one candidate per pv */
len = sizeof(*areas) * pv_count;
if (!(areas = dbg_malloc(sizeof(*areas) * pv_count))) {
log_err("Couldn't allocate areas array.");
return 0;
}
while (allocated != lv->le_count) {
index = 0;
list_iterate (pvmh, pvms) {
pvm = list_item(pvmh, struct pv_map);
if (list_empty(&pvm->areas))
continue;
areas[index++] = list_item(pvm->areas.n,
struct pv_area);
}
if (index < stripes) {
log_error("Insufficient free extents (suitable for "
"striping) to allocate logical volume "
"%s: %u required",
lv->name, lv->le_count);
goto out;
}
/* sort the areas so we allocate from the biggest */
qsort(areas, index, sizeof(*areas), _comp_area);
if (!_alloc_stripe_area(lv, stripes, stripe_size, areas,
&allocated)) {
stack;
goto out;
}
}
r = 1;
out:
dbg_free(areas);
return r;
}
/*
* The heart of the allocation code. This
* function takes a pv_area and allocates it to
* the lv. If the lv doesn't need the complete
* area then the area is split, otherwise the area
* is unlinked from the pv_map.
*/
static int _alloc_linear_area(struct logical_volume *lv, uint32_t *index,
struct pv_map *map, struct pv_area *pva)
{
uint32_t count, remaining;
struct stripe_segment *seg;
count = pva->count;
remaining = lv->le_count - *index;
if (count > remaining)
count = remaining;
if (!(seg = _alloc_segment(lv->vg->cmd->mem, 1))) {
log_err("Couldn't allocate new stripe segment.");
return 0;
}
seg->lv = lv;
seg->le = *index;
seg->len = count;
seg->stripe_size = 0;
seg->stripes = 1;
seg->area[0].pv = map->pv;
seg->area[0].pe = pva->start;
list_add(&lv->segments, &seg->list);
consume_pv_area(pva, count);
*index += count;
return 1;
}
/*
* Only one area per pv is allowed, so we search
* for the biggest area, or the first area that
* can complete the allocation.
*/
/*
* FIXME: subsequent lvextends may not be contiguous.
*/
static int _alloc_contiguous(struct logical_volume *lv,
struct list *pvms, uint32_t allocated)
{
struct list *tmp1;
struct pv_map *pvm;
struct pv_area *pva;
list_iterate(tmp1, pvms) {
pvm = list_item(tmp1, struct pv_map);
if (list_empty(&pvm->areas))
continue;
/* first item in the list is the biggest */
pva = list_item(pvm->areas.n, struct pv_area);
if (!_alloc_linear_area(lv, &allocated, pvm, pva)) {
stack;
return 0;
}
if (allocated == lv->le_count)
break;
}
if (allocated != lv->le_count) {
log_error("Insufficient free extents to "
"allocate logical volume %s: %u required",
lv->name, lv->le_count);
return 0;
}
return 1;
}
/*
* Areas just get allocated in order until the lv
* is full.
*/
static int _alloc_simple(struct logical_volume *lv,
struct list *pvms, uint32_t allocated)
{
struct list *tmp1, *tmp2;
struct pv_map *pvm;
struct pv_area *pva;
list_iterate(tmp1, pvms) {
pvm = list_item(tmp1, struct pv_map);
list_iterate(tmp2, &pvm->areas) {
pva = list_item(tmp2, struct pv_area);
if (!_alloc_linear_area(lv, &allocated, pvm, pva) ||
(allocated == lv->le_count))
goto done;
}
}
done:
if (allocated != lv->le_count) {
log_error("Insufficient free logical extents to "
"allocate logical volume %s: %u required",
lv->name, lv->le_count);
return 0;
}
return 1;
}
/*
* Chooses a correct allocation policy.
*/
static int _allocate(struct volume_group *vg, struct logical_volume *lv,
struct list *acceptable_pvs, uint32_t allocated,
uint32_t stripes, uint32_t stripe_size)
{
int r = 0;
struct pool *scratch;
struct list *pvms, *old_tail = lv->segments.p, *segh;
if (!(scratch = pool_create(1024))) {
stack;
return 0;
}
/*
* Build the sets of available areas on
* the pv's.
*/
if (!(pvms = create_pv_maps(scratch, vg, acceptable_pvs))) {
goto out;
}
if (stripes > 1)
r = _alloc_striped(lv, pvms, allocated, stripes, stripe_size);
else if (lv->status & ALLOC_CONTIGUOUS)
r = _alloc_contiguous(lv, pvms, allocated);
else if (lv->status & ALLOC_SIMPLE)
r = _alloc_simple(lv, pvms, allocated);
else {
log_error("Unknown allocation policy: "
"unable to setup logical volume.");
goto out;
}
if (r) {
vg->free_count -= lv->le_count - allocated;
/* Iterate through the new segments,
* updating pe counts in pv's. */
for (segh = lv->segments.p; segh != old_tail; segh = segh->p)
_get_extents(list_item(segh, struct stripe_segment));
} else {
/* Put the segment list back how
* we found it. */
old_tail->n = &lv->segments;
lv->segments.p = old_tail;
}
out:
pool_destroy(scratch);
return r;
}
static char *_generate_lv_name(struct volume_group *vg,
char *buffer, size_t len)
{
struct list *lvh;
struct logical_volume *lv;
int high = -1, i, s;
list_iterate(lvh, &vg->lvs) {
lv = &(list_item(lvh, struct lv_list)->lv);
if (sscanf(lv->name, "lvol%d", &i) != 1)
continue;
if (i > high)
high = i;
}
if ((s = snprintf(buffer, len, "lvol%d", high + 1)) < 0 || s >= len)
return NULL;
return buffer;
}
struct logical_volume *lv_create(const char *name,
uint32_t status,
uint32_t stripes,
uint32_t stripe_size,
uint32_t extents,
struct volume_group *vg,
struct list *acceptable_pvs)
{
struct cmd_context *cmd = vg->cmd;
struct lv_list *ll = NULL;
struct logical_volume *lv;
char dname[32];
if (!extents) {
log_error("Unable to create logical volume %s with no extents",
name);
return NULL;
}
if (vg->free_count < extents) {
log_error("Insufficient free extents (%u) in volume group %s: "
"%u required", vg->free_count, vg->name, extents);
return NULL;
}
if (vg->max_lv == vg->lv_count) {
log_error("Maximum number of logical volumes (%u) reached "
"in volume group %s", vg->max_lv, vg->name);
return NULL;
}
if (stripes > list_size(acceptable_pvs)) {
log_error("Number of stripes (%u) must not exceed "
"number of physical volumes (%d)", stripes,
list_size(acceptable_pvs));
return NULL;
}
if (!name && !(name = _generate_lv_name(vg, dname, sizeof(dname)))) {
log_error("Failed to generate unique name for the new "
"logical volume");
return NULL;
}
log_verbose("Creating logical volume %s", name);
if (!(ll = pool_zalloc(cmd->mem, sizeof(*ll)))) {
stack;
return NULL;
}
list_init(&ll->list);
lv = &ll->lv;
strcpy(lv->id.uuid, "");
if (!(lv->name = pool_strdup(cmd->mem, name))) {
stack;
goto bad;
}
lv->status = status;
lv->read_ahead = 0;
lv->size = extents * vg->extent_size;
lv->le_count = extents;
lv->vg = vg;
list_init(&lv->segments);
if (!_allocate(vg, lv, acceptable_pvs, 0u, stripes, stripe_size)) {
stack;
goto bad;
}
vg->lv_count++;
list_add(&vg->lvs, &ll->list);
return lv;
bad:
if (ll)
pool_free(cmd->mem, ll);
return NULL;
}
int lv_reduce(struct logical_volume *lv, uint32_t extents)
{
struct list *segh;
struct stripe_segment *seg;
uint32_t count = extents;
for (segh = lv->segments.p;
(segh != &lv->segments) && count;
segh = segh->p) {
seg = list_item(segh, struct stripe_segment);
if (seg->len <= count) {
/* remove this segment completely */
count -= seg->len;
_put_extents(seg);
list_del(segh);
} else {
/* reduce this segment */
_put_extents(seg);
seg->len -= count;
_get_extents(seg);
count = 0;
}
}
lv->le_count -= extents;
lv->size = lv->le_count * lv->vg->extent_size;
return 1;
}
int lv_extend(struct logical_volume *lv,
uint32_t stripes, uint32_t stripe_size,
uint32_t extents,
struct list *acceptable_pvs)
{
uint32_t old_le_count = lv->le_count;
uint64_t old_size = lv->size;
lv->le_count += extents;
lv->size += extents * lv->vg->extent_size;
/* FIXME: Format1 must ensure stripes is consistent with 1st seg */
if (!_allocate(lv->vg, lv, acceptable_pvs, old_le_count,
stripes, stripe_size)) {
lv->le_count = old_le_count;
lv->size = old_size;
return 0;
}
return 1;
}
int lv_remove(struct volume_group *vg, struct logical_volume *lv)
{
struct list *segh;
/* iterate through the lv's segments freeing off the pe's */
list_iterate (segh, &lv->segments)
_put_extents(list_item(segh, struct stripe_segment));
vg->lv_count--;
vg->free_count += lv->le_count;
list_del(&list_head(lv, struct lv_list, lv));
return 1;
}