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/* $OpenBSD: tmpfs_mem.c,v 1.7 2015/03/14 03:38:52 jsg Exp $ */
/* $NetBSD: tmpfs_mem.c,v 1.4 2011/05/24 01:09:47 rmind Exp $ */
/*
* Copyright (c) 2010, 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mindaugas Rasiukevicius.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* tmpfs memory allocation routines.
* Implements memory usage accounting and limiting.
*/
#include <sys/param.h>
#include <sys/namei.h>
#include <sys/pool.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <tmpfs/tmpfs.h>
extern struct pool tmpfs_dirent_pool;
extern struct pool tmpfs_node_pool;
void
tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit)
{
rw_init(&mp->tm_acc_lock, "tacclk");
mp->tm_mem_limit = memlimit;
mp->tm_bytes_used = 0;
}
void
tmpfs_mntmem_destroy(struct tmpfs_mount *mp)
{
KASSERT(mp->tm_bytes_used == 0);
/* mutex_destroy(&mp->tm_acc_lock); */
}
/*
* tmpfs_mem_info: return the number of available memory pages.
*
* => If 'total' is true, then return _total_ amount of pages.
* => If false, then return the amount of _free_ memory pages.
*
* Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid
* excessive memory usage.
*/
size_t
tmpfs_mem_info(int total)
{
int size = 0;
/* XXX: unlocked */
size += uvmexp.swpages;
if (!total) {
size -= uvmexp.swpgonly;
}
size += uvmexp.free;
/* size += uvmexp.filepages; */
if (size > uvmexp.wired) {
size -= uvmexp.wired;
} else {
size = 0;
}
KASSERT(size >= 0);
return (size_t)size;
}
uint64_t
tmpfs_bytes_max(struct tmpfs_mount *mp)
{
size_t freepages = tmpfs_mem_info(0);
uint64_t avail_mem;
if (freepages < TMPFS_PAGES_RESERVED) {
freepages = 0;
} else {
freepages -= TMPFS_PAGES_RESERVED;
}
avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT);
return MIN(mp->tm_mem_limit, avail_mem);
}
uint64_t
tmpfs_pages_avail(struct tmpfs_mount *mp)
{
return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT;
}
int
tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz)
{
uint64_t lim;
rw_enter_write(&mp->tm_acc_lock);
lim = tmpfs_bytes_max(mp);
if (mp->tm_bytes_used + sz >= lim) {
rw_exit_write(&mp->tm_acc_lock);
return 0;
}
mp->tm_bytes_used += sz;
rw_exit_write(&mp->tm_acc_lock);
return 1;
}
void
tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz)
{
rw_enter_write(&mp->tm_acc_lock);
KASSERT(mp->tm_bytes_used >= sz);
mp->tm_bytes_used -= sz;
rw_exit_write(&mp->tm_acc_lock);
}
struct tmpfs_dirent *
tmpfs_dirent_get(struct tmpfs_mount *mp)
{
if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) {
return NULL;
}
return pool_get(&tmpfs_dirent_pool, PR_WAITOK);
}
void
tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de)
{
tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent));
pool_put(&tmpfs_dirent_pool, de);
}
struct tmpfs_node *
tmpfs_node_get(struct tmpfs_mount *mp)
{
mp->tm_nodes_cnt++;
if (mp->tm_nodes_cnt > mp->tm_nodes_max) {
mp->tm_nodes_cnt--;
return NULL;
}
if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) {
return NULL;
}
return pool_get(&tmpfs_node_pool, PR_WAITOK);
}
void
tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn)
{
mp->tm_nodes_cnt--;
tmpfs_mem_decr(mp, sizeof(struct tmpfs_node));
pool_put(&tmpfs_node_pool, tn);
}
/*
* Quantum size to round-up the tmpfs names in order to reduce re-allocations.
*/
#define TMPFS_NAME_QUANTUM (32)
#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
char *
tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len)
{
const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM);
KASSERT(sz > 0 && sz <= 1024);
if (!tmpfs_mem_incr(mp, sz)) {
return NULL;
}
return malloc(sz, M_TEMP, M_WAITOK); /* XXX */
}
void
tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len)
{
const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM);
KASSERT(sz > 0 && sz <= 1024);
tmpfs_mem_decr(mp, sz);
free(str, M_TEMP, sz);
}
int
tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp)
{
const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM);
const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM);
return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln);
}
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