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/*
* 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mempool.h>
#include "netfs.h"
static struct kmem_cache *pohmelfs_mcache_cache;
static mempool_t *pohmelfs_mcache_pool;
static inline int pohmelfs_mcache_cmp(u64 gen, u64 new)
{
if (gen < new)
return 1;
if (gen > new)
return -1;
return 0;
}
struct pohmelfs_mcache *pohmelfs_mcache_search(struct pohmelfs_sb *psb, u64 gen)
{
struct rb_root *root = &psb->mcache_root;
struct rb_node *n = root->rb_node;
struct pohmelfs_mcache *tmp, *ret = NULL;
int cmp;
while (n) {
tmp = rb_entry(n, struct pohmelfs_mcache, mcache_entry);
cmp = pohmelfs_mcache_cmp(tmp->gen, gen);
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else {
ret = tmp;
pohmelfs_mcache_get(ret);
break;
}
}
return ret;
}
static int pohmelfs_mcache_insert(struct pohmelfs_sb *psb, struct pohmelfs_mcache *m)
{
struct rb_root *root = &psb->mcache_root;
struct rb_node **n = &root->rb_node, *parent = NULL;
struct pohmelfs_mcache *ret = NULL, *tmp;
int cmp;
while (*n) {
parent = *n;
tmp = rb_entry(parent, struct pohmelfs_mcache, mcache_entry);
cmp = pohmelfs_mcache_cmp(tmp->gen, m->gen);
if (cmp < 0)
n = &parent->rb_left;
else if (cmp > 0)
n = &parent->rb_right;
else {
ret = tmp;
break;
}
}
if (ret)
return -EEXIST;
rb_link_node(&m->mcache_entry, parent, n);
rb_insert_color(&m->mcache_entry, root);
return 0;
}
static int pohmelfs_mcache_remove(struct pohmelfs_sb *psb, struct pohmelfs_mcache *m)
{
if (m && m->mcache_entry.rb_parent_color) {
rb_erase(&m->mcache_entry, &psb->mcache_root);
m->mcache_entry.rb_parent_color = 0;
return 1;
}
return 0;
}
void pohmelfs_mcache_remove_locked(struct pohmelfs_sb *psb, struct pohmelfs_mcache *m)
{
mutex_lock(&psb->mcache_lock);
pohmelfs_mcache_remove(psb, m);
mutex_unlock(&psb->mcache_lock);
}
struct pohmelfs_mcache *pohmelfs_mcache_alloc(struct pohmelfs_sb *psb, u64 start,
unsigned int size, void *data)
{
struct pohmelfs_mcache *m;
int err = -ENOMEM;
m = mempool_alloc(pohmelfs_mcache_pool, GFP_KERNEL);
if (!m)
goto err_out_exit;
init_completion(&m->complete);
m->err = 0;
atomic_set(&m->refcnt, 1);
m->data = data;
m->start = start;
m->size = size;
m->gen = atomic_long_inc_return(&psb->mcache_gen);
mutex_lock(&psb->mcache_lock);
err = pohmelfs_mcache_insert(psb, m);
mutex_unlock(&psb->mcache_lock);
if (err)
goto err_out_free;
return m;
err_out_free:
mempool_free(m, pohmelfs_mcache_pool);
err_out_exit:
return ERR_PTR(err);
}
void pohmelfs_mcache_free(struct pohmelfs_sb *psb, struct pohmelfs_mcache *m)
{
pohmelfs_mcache_remove_locked(psb, m);
mempool_free(m, pohmelfs_mcache_pool);
}
int __init pohmelfs_mcache_init(void)
{
pohmelfs_mcache_cache = kmem_cache_create("pohmelfs_mcache_cache",
sizeof(struct pohmelfs_mcache),
0, (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD), NULL);
if (!pohmelfs_mcache_cache)
goto err_out_exit;
pohmelfs_mcache_pool = mempool_create_slab_pool(256, pohmelfs_mcache_cache);
if (!pohmelfs_mcache_pool)
goto err_out_free;
return 0;
err_out_free:
kmem_cache_destroy(pohmelfs_mcache_cache);
err_out_exit:
return -ENOMEM;
}
void pohmelfs_mcache_exit(void)
{
mempool_destroy(pohmelfs_mcache_pool);
kmem_cache_destroy(pohmelfs_mcache_cache);
}
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