mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-17 01:34:00 +08:00
3241b1d3e0
The persistent-data library offers a re-usable framework for the storage and management of on-disk metadata in device-mapper targets. It's used by the thin-provisioning target in the next patch and in an upcoming hierarchical storage target. For further information, please read Documentation/device-mapper/persistent-data.txt Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
597 lines
12 KiB
C
597 lines
12 KiB
C
/*
|
|
* Copyright (C) 2011 Red Hat, Inc.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#include "dm-space-map.h"
|
|
#include "dm-space-map-common.h"
|
|
#include "dm-space-map-metadata.h"
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/device-mapper.h>
|
|
|
|
#define DM_MSG_PREFIX "space map metadata"
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* Space map interface.
|
|
*
|
|
* The low level disk format is written using the standard btree and
|
|
* transaction manager. This means that performing disk operations may
|
|
* cause us to recurse into the space map in order to allocate new blocks.
|
|
* For this reason we have a pool of pre-allocated blocks large enough to
|
|
* service any metadata_ll_disk operation.
|
|
*/
|
|
|
|
/*
|
|
* FIXME: we should calculate this based on the size of the device.
|
|
* Only the metadata space map needs this functionality.
|
|
*/
|
|
#define MAX_RECURSIVE_ALLOCATIONS 1024
|
|
|
|
enum block_op_type {
|
|
BOP_INC,
|
|
BOP_DEC
|
|
};
|
|
|
|
struct block_op {
|
|
enum block_op_type type;
|
|
dm_block_t block;
|
|
};
|
|
|
|
struct sm_metadata {
|
|
struct dm_space_map sm;
|
|
|
|
struct ll_disk ll;
|
|
struct ll_disk old_ll;
|
|
|
|
dm_block_t begin;
|
|
|
|
unsigned recursion_count;
|
|
unsigned allocated_this_transaction;
|
|
unsigned nr_uncommitted;
|
|
struct block_op uncommitted[MAX_RECURSIVE_ALLOCATIONS];
|
|
};
|
|
|
|
static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b)
|
|
{
|
|
struct block_op *op;
|
|
|
|
if (smm->nr_uncommitted == MAX_RECURSIVE_ALLOCATIONS) {
|
|
DMERR("too many recursive allocations");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
op = smm->uncommitted + smm->nr_uncommitted++;
|
|
op->type = type;
|
|
op->block = b;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int commit_bop(struct sm_metadata *smm, struct block_op *op)
|
|
{
|
|
int r = 0;
|
|
enum allocation_event ev;
|
|
|
|
switch (op->type) {
|
|
case BOP_INC:
|
|
r = sm_ll_inc(&smm->ll, op->block, &ev);
|
|
break;
|
|
|
|
case BOP_DEC:
|
|
r = sm_ll_dec(&smm->ll, op->block, &ev);
|
|
break;
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
static void in(struct sm_metadata *smm)
|
|
{
|
|
smm->recursion_count++;
|
|
}
|
|
|
|
static int out(struct sm_metadata *smm)
|
|
{
|
|
int r = 0;
|
|
|
|
/*
|
|
* If we're not recursing then very bad things are happening.
|
|
*/
|
|
if (!smm->recursion_count) {
|
|
DMERR("lost track of recursion depth");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (smm->recursion_count == 1 && smm->nr_uncommitted) {
|
|
while (smm->nr_uncommitted && !r) {
|
|
smm->nr_uncommitted--;
|
|
r = commit_bop(smm, smm->uncommitted +
|
|
smm->nr_uncommitted);
|
|
if (r)
|
|
break;
|
|
}
|
|
}
|
|
|
|
smm->recursion_count--;
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* When using the out() function above, we often want to combine an error
|
|
* code for the operation run in the recursive context with that from
|
|
* out().
|
|
*/
|
|
static int combine_errors(int r1, int r2)
|
|
{
|
|
return r1 ? r1 : r2;
|
|
}
|
|
|
|
static int recursing(struct sm_metadata *smm)
|
|
{
|
|
return smm->recursion_count;
|
|
}
|
|
|
|
static void sm_metadata_destroy(struct dm_space_map *sm)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
kfree(smm);
|
|
}
|
|
|
|
static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
|
|
{
|
|
DMERR("doesn't support extend");
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int sm_metadata_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
*count = smm->ll.nr_blocks;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
*count = smm->old_ll.nr_blocks - smm->old_ll.nr_allocated -
|
|
smm->allocated_this_transaction;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b,
|
|
uint32_t *result)
|
|
{
|
|
int r, i;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
unsigned adjustment = 0;
|
|
|
|
/*
|
|
* We may have some uncommitted adjustments to add. This list
|
|
* should always be really short.
|
|
*/
|
|
for (i = 0; i < smm->nr_uncommitted; i++) {
|
|
struct block_op *op = smm->uncommitted + i;
|
|
|
|
if (op->block != b)
|
|
continue;
|
|
|
|
switch (op->type) {
|
|
case BOP_INC:
|
|
adjustment++;
|
|
break;
|
|
|
|
case BOP_DEC:
|
|
adjustment--;
|
|
break;
|
|
}
|
|
}
|
|
|
|
r = sm_ll_lookup(&smm->ll, b, result);
|
|
if (r)
|
|
return r;
|
|
|
|
*result += adjustment;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_count_is_more_than_one(struct dm_space_map *sm,
|
|
dm_block_t b, int *result)
|
|
{
|
|
int r, i, adjustment = 0;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
uint32_t rc;
|
|
|
|
/*
|
|
* We may have some uncommitted adjustments to add. This list
|
|
* should always be really short.
|
|
*/
|
|
for (i = 0; i < smm->nr_uncommitted; i++) {
|
|
struct block_op *op = smm->uncommitted + i;
|
|
|
|
if (op->block != b)
|
|
continue;
|
|
|
|
switch (op->type) {
|
|
case BOP_INC:
|
|
adjustment++;
|
|
break;
|
|
|
|
case BOP_DEC:
|
|
adjustment--;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (adjustment > 1) {
|
|
*result = 1;
|
|
return 0;
|
|
}
|
|
|
|
r = sm_ll_lookup_bitmap(&smm->ll, b, &rc);
|
|
if (r)
|
|
return r;
|
|
|
|
if (rc == 3)
|
|
/*
|
|
* We err on the side of caution, and always return true.
|
|
*/
|
|
*result = 1;
|
|
else
|
|
*result = rc + adjustment > 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_set_count(struct dm_space_map *sm, dm_block_t b,
|
|
uint32_t count)
|
|
{
|
|
int r, r2;
|
|
enum allocation_event ev;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
if (smm->recursion_count) {
|
|
DMERR("cannot recurse set_count()");
|
|
return -EINVAL;
|
|
}
|
|
|
|
in(smm);
|
|
r = sm_ll_insert(&smm->ll, b, count, &ev);
|
|
r2 = out(smm);
|
|
|
|
return combine_errors(r, r2);
|
|
}
|
|
|
|
static int sm_metadata_inc_block(struct dm_space_map *sm, dm_block_t b)
|
|
{
|
|
int r, r2 = 0;
|
|
enum allocation_event ev;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
if (recursing(smm))
|
|
r = add_bop(smm, BOP_INC, b);
|
|
else {
|
|
in(smm);
|
|
r = sm_ll_inc(&smm->ll, b, &ev);
|
|
r2 = out(smm);
|
|
}
|
|
|
|
return combine_errors(r, r2);
|
|
}
|
|
|
|
static int sm_metadata_dec_block(struct dm_space_map *sm, dm_block_t b)
|
|
{
|
|
int r, r2 = 0;
|
|
enum allocation_event ev;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
if (recursing(smm))
|
|
r = add_bop(smm, BOP_DEC, b);
|
|
else {
|
|
in(smm);
|
|
r = sm_ll_dec(&smm->ll, b, &ev);
|
|
r2 = out(smm);
|
|
}
|
|
|
|
return combine_errors(r, r2);
|
|
}
|
|
|
|
static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
|
|
{
|
|
int r, r2 = 0;
|
|
enum allocation_event ev;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
r = sm_ll_find_free_block(&smm->old_ll, smm->begin, smm->old_ll.nr_blocks, b);
|
|
if (r)
|
|
return r;
|
|
|
|
smm->begin = *b + 1;
|
|
|
|
if (recursing(smm))
|
|
r = add_bop(smm, BOP_INC, *b);
|
|
else {
|
|
in(smm);
|
|
r = sm_ll_inc(&smm->ll, *b, &ev);
|
|
r2 = out(smm);
|
|
}
|
|
|
|
if (!r)
|
|
smm->allocated_this_transaction++;
|
|
|
|
return combine_errors(r, r2);
|
|
}
|
|
|
|
static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
|
|
{
|
|
int r = sm_metadata_new_block_(sm, b);
|
|
if (r)
|
|
DMERR("out of metadata space");
|
|
return r;
|
|
}
|
|
|
|
static int sm_metadata_commit(struct dm_space_map *sm)
|
|
{
|
|
int r;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
r = sm_ll_commit(&smm->ll);
|
|
if (r)
|
|
return r;
|
|
|
|
memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
|
|
smm->begin = 0;
|
|
smm->allocated_this_transaction = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
|
|
{
|
|
*result = sizeof(struct disk_sm_root);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
struct disk_sm_root root_le;
|
|
|
|
root_le.nr_blocks = cpu_to_le64(smm->ll.nr_blocks);
|
|
root_le.nr_allocated = cpu_to_le64(smm->ll.nr_allocated);
|
|
root_le.bitmap_root = cpu_to_le64(smm->ll.bitmap_root);
|
|
root_le.ref_count_root = cpu_to_le64(smm->ll.ref_count_root);
|
|
|
|
if (max < sizeof(root_le))
|
|
return -ENOSPC;
|
|
|
|
memcpy(where_le, &root_le, sizeof(root_le));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dm_space_map ops = {
|
|
.destroy = sm_metadata_destroy,
|
|
.extend = sm_metadata_extend,
|
|
.get_nr_blocks = sm_metadata_get_nr_blocks,
|
|
.get_nr_free = sm_metadata_get_nr_free,
|
|
.get_count = sm_metadata_get_count,
|
|
.count_is_more_than_one = sm_metadata_count_is_more_than_one,
|
|
.set_count = sm_metadata_set_count,
|
|
.inc_block = sm_metadata_inc_block,
|
|
.dec_block = sm_metadata_dec_block,
|
|
.new_block = sm_metadata_new_block,
|
|
.commit = sm_metadata_commit,
|
|
.root_size = sm_metadata_root_size,
|
|
.copy_root = sm_metadata_copy_root
|
|
};
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* When a new space map is created that manages its own space. We use
|
|
* this tiny bootstrap allocator.
|
|
*/
|
|
static void sm_bootstrap_destroy(struct dm_space_map *sm)
|
|
{
|
|
}
|
|
|
|
static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
|
|
{
|
|
DMERR("boostrap doesn't support extend");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int sm_bootstrap_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
return smm->ll.nr_blocks;
|
|
}
|
|
|
|
static int sm_bootstrap_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
*count = smm->ll.nr_blocks - smm->begin;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_bootstrap_get_count(struct dm_space_map *sm, dm_block_t b,
|
|
uint32_t *result)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
return b < smm->begin ? 1 : 0;
|
|
}
|
|
|
|
static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
|
|
dm_block_t b, int *result)
|
|
{
|
|
*result = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
|
|
uint32_t count)
|
|
{
|
|
DMERR("boostrap doesn't support set_count");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int sm_bootstrap_new_block(struct dm_space_map *sm, dm_block_t *b)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
/*
|
|
* We know the entire device is unused.
|
|
*/
|
|
if (smm->begin == smm->ll.nr_blocks)
|
|
return -ENOSPC;
|
|
|
|
*b = smm->begin++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sm_bootstrap_inc_block(struct dm_space_map *sm, dm_block_t b)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
return add_bop(smm, BOP_INC, b);
|
|
}
|
|
|
|
static int sm_bootstrap_dec_block(struct dm_space_map *sm, dm_block_t b)
|
|
{
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
return add_bop(smm, BOP_DEC, b);
|
|
}
|
|
|
|
static int sm_bootstrap_commit(struct dm_space_map *sm)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
|
|
{
|
|
DMERR("boostrap doesn't support root_size");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
|
|
size_t max)
|
|
{
|
|
DMERR("boostrap doesn't support copy_root");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct dm_space_map bootstrap_ops = {
|
|
.destroy = sm_bootstrap_destroy,
|
|
.extend = sm_bootstrap_extend,
|
|
.get_nr_blocks = sm_bootstrap_get_nr_blocks,
|
|
.get_nr_free = sm_bootstrap_get_nr_free,
|
|
.get_count = sm_bootstrap_get_count,
|
|
.count_is_more_than_one = sm_bootstrap_count_is_more_than_one,
|
|
.set_count = sm_bootstrap_set_count,
|
|
.inc_block = sm_bootstrap_inc_block,
|
|
.dec_block = sm_bootstrap_dec_block,
|
|
.new_block = sm_bootstrap_new_block,
|
|
.commit = sm_bootstrap_commit,
|
|
.root_size = sm_bootstrap_root_size,
|
|
.copy_root = sm_bootstrap_copy_root
|
|
};
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
struct dm_space_map *dm_sm_metadata_init(void)
|
|
{
|
|
struct sm_metadata *smm;
|
|
|
|
smm = kmalloc(sizeof(*smm), GFP_KERNEL);
|
|
if (!smm)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
memcpy(&smm->sm, &ops, sizeof(smm->sm));
|
|
|
|
return &smm->sm;
|
|
}
|
|
|
|
int dm_sm_metadata_create(struct dm_space_map *sm,
|
|
struct dm_transaction_manager *tm,
|
|
dm_block_t nr_blocks,
|
|
dm_block_t superblock)
|
|
{
|
|
int r;
|
|
dm_block_t i;
|
|
enum allocation_event ev;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
smm->begin = superblock + 1;
|
|
smm->recursion_count = 0;
|
|
smm->allocated_this_transaction = 0;
|
|
smm->nr_uncommitted = 0;
|
|
|
|
memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
|
|
|
|
r = sm_ll_new_metadata(&smm->ll, tm);
|
|
if (r)
|
|
return r;
|
|
|
|
r = sm_ll_extend(&smm->ll, nr_blocks);
|
|
if (r)
|
|
return r;
|
|
|
|
memcpy(&smm->sm, &ops, sizeof(smm->sm));
|
|
|
|
/*
|
|
* Now we need to update the newly created data structures with the
|
|
* allocated blocks that they were built from.
|
|
*/
|
|
for (i = superblock; !r && i < smm->begin; i++)
|
|
r = sm_ll_inc(&smm->ll, i, &ev);
|
|
|
|
if (r)
|
|
return r;
|
|
|
|
return sm_metadata_commit(sm);
|
|
}
|
|
|
|
int dm_sm_metadata_open(struct dm_space_map *sm,
|
|
struct dm_transaction_manager *tm,
|
|
void *root_le, size_t len)
|
|
{
|
|
int r;
|
|
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
|
|
|
|
r = sm_ll_open_metadata(&smm->ll, tm, root_le, len);
|
|
if (r)
|
|
return r;
|
|
|
|
smm->begin = 0;
|
|
smm->recursion_count = 0;
|
|
smm->allocated_this_transaction = 0;
|
|
smm->nr_uncommitted = 0;
|
|
|
|
memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
|
|
return 0;
|
|
}
|