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lvm2/lib/metadata/lv_manip.c
Alasdair Kergon 4a624ca055 o ACTIVE is no longer a status flag - lv_active() used to check if an LV
is active in the device-mapper.
o Many operations can be carried out regardless of whether the VG is
  active or not.
o vgscan does not activate anything - use vgchange.
o Change lvrename to support renaming of active LVs.
o Remove '//' appearing in some pathnames.
o Dummy lv_check_segments() for compilation.
2002-01-10 23:21:07 +00:00

524 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 "lvm-string.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;
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 (lvm_snprintf(buffer, len, "lvol%d", high + 1) < 0)
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;
}
if (!lv_merge_segments(lv)) {
log_err("Couldn't merge segments after extending "
"logical volume.");
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;
}