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/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map-common.h"
#include "dm-space-map-disk.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "space map disk"
/*----------------------------------------------------------------*/
/*
* Space map interface.
*/
struct sm_disk {
struct dm_space_map sm;
struct ll_disk ll;
struct ll_disk old_ll;
dm_block_t begin;
dm_block_t nr_allocated_this_transaction;
};
static void sm_disk_destroy(struct dm_space_map *sm)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
kfree(smd);
}
static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
return sm_ll_extend(&smd->ll, extra_blocks);
}
static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
*count = smd->old_ll.nr_blocks;
return 0;
}
static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
return 0;
}
static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
uint32_t *result)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
return sm_ll_lookup(&smd->ll, b, result);
}
static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
int *result)
{
int r;
uint32_t count;
r = sm_disk_get_count(sm, b, &count);
if (r)
return r;
return count > 1;
}
static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
uint32_t count)
{
int r;
uint32_t old_count;
enum allocation_event ev;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_insert(&smd->ll, b, count, &ev);
if (!r) {
switch (ev) {
case SM_NONE:
break;
case SM_ALLOC:
/*
* This _must_ be free in the prior transaction
* otherwise we've lost atomicity.
*/
smd->nr_allocated_this_transaction++;
break;
case SM_FREE:
/*
* It's only free if it's also free in the last
* transaction.
*/
r = sm_ll_lookup(&smd->old_ll, b, &old_count);
if (r)
return r;
if (!old_count)
smd->nr_allocated_this_transaction--;
break;
}
}
return r;
}
static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
{
int r;
enum allocation_event ev;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_inc(&smd->ll, b, &ev);
if (!r && (ev == SM_ALLOC))
/*
* This _must_ be free in the prior transaction
* otherwise we've lost atomicity.
*/
smd->nr_allocated_this_transaction++;
return r;
}
static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
{
int r;
uint32_t old_count;
enum allocation_event ev;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_dec(&smd->ll, b, &ev);
if (!r && (ev == SM_FREE)) {
/*
* It's only free if it's also free in the last
* transaction.
*/
r = sm_ll_lookup(&smd->old_ll, b, &old_count);
if (r)
return r;
if (!old_count)
smd->nr_allocated_this_transaction--;
}
return r;
}
static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
{
int r;
enum allocation_event ev;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
/* FIXME: we should loop round a couple of times */
r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
if (r)
return r;
smd->begin = *b + 1;
r = sm_ll_inc(&smd->ll, *b, &ev);
if (!r) {
BUG_ON(ev != SM_ALLOC);
smd->nr_allocated_this_transaction++;
}
return r;
}
static int sm_disk_commit(struct dm_space_map *sm)
{
int r;
dm_block_t nr_free;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_disk_get_nr_free(sm, &nr_free);
if (r)
return r;
r = sm_ll_commit(&smd->ll);
if (r)
return r;
memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
smd->begin = 0;
smd->nr_allocated_this_transaction = 0;
r = sm_disk_get_nr_free(sm, &nr_free);
if (r)
return r;
return 0;
}
static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
{
*result = sizeof(struct disk_sm_root);
return 0;
}
static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
struct disk_sm_root root_le;
root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
root_le.ref_count_root = cpu_to_le64(smd->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_disk_destroy,
.extend = sm_disk_extend,
.get_nr_blocks = sm_disk_get_nr_blocks,
.get_nr_free = sm_disk_get_nr_free,
.get_count = sm_disk_get_count,
.count_is_more_than_one = sm_disk_count_is_more_than_one,
.set_count = sm_disk_set_count,
.inc_block = sm_disk_inc_block,
.dec_block = sm_disk_dec_block,
.new_block = sm_disk_new_block,
.commit = sm_disk_commit,
.root_size = sm_disk_root_size,
.copy_root = sm_disk_copy_root,
.register_threshold_callback = NULL
};
struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
dm_block_t nr_blocks)
{
int r;
struct sm_disk *smd;
smd = kmalloc(sizeof(*smd), GFP_KERNEL);
if (!smd)
return ERR_PTR(-ENOMEM);
smd->begin = 0;
smd->nr_allocated_this_transaction = 0;
memcpy(&smd->sm, &ops, sizeof(smd->sm));
r = sm_ll_new_disk(&smd->ll, tm);
if (r)
goto bad;
r = sm_ll_extend(&smd->ll, nr_blocks);
if (r)
goto bad;
r = sm_disk_commit(&smd->sm);
if (r)
goto bad;
return &smd->sm;
bad:
kfree(smd);
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_sm_disk_create);
struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct sm_disk *smd;
smd = kmalloc(sizeof(*smd), GFP_KERNEL);
if (!smd)
return ERR_PTR(-ENOMEM);
smd->begin = 0;
smd->nr_allocated_this_transaction = 0;
memcpy(&smd->sm, &ops, sizeof(smd->sm));
r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
if (r)
goto bad;
r = sm_disk_commit(&smd->sm);
if (r)
goto bad;
return &smd->sm;
bad:
kfree(smd);
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_sm_disk_open);
/*----------------------------------------------------------------*/
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