usbloadergx/source/libntfs/cache.c
dimok321 64f8406b07 *Mem2 fix
*updated libntfs (write fix)
*updated libfat
*lots of changes in the startup code, removed almost everything. This might cause problems for some drives at loading the gamelist and needs to be adjusted later but better this time. more cleanup is needed in main.cpp and will come.
*using libogc sd/usb for config loading and reload to cIOS afterwards
*added missing boothomebrew stuff pune forgot

NOTE: From now on we will be doing a lot of revs which we won't be compiling and releasing. This revs are officially not available for public so don't making issues regarding those revs. Those will be closed right away. We need first to cleanup a lot of crap and update loader to new standards before releasing stuff again.
2010-09-16 19:59:41 +00:00

610 lines
15 KiB
C

/**
* cache.c : deal with LRU caches
*
* Copyright (c) 2008-2009 Jean-Pierre Andre
*
* This program/include file 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/include file 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.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "types.h"
#include "security.h"
#include "cache.h"
#include "misc.h"
#include "logging.h"
/*
* General functions to deal with LRU caches
*
* The cached data have to be organized in a structure in which
* the first fields must follow a mandatory pattern and further
* fields may contain any fixed size data. They are stored in an
* LRU list.
*
* A compare function must be provided for finding a wanted entry
* in the cache. Another function may be provided for invalidating
* an entry to facilitate multiple invalidation.
*
* These functions never return error codes. When there is a
* shortage of memory, data is simply not cached.
* When there is a hashing bug, hashing is dropped, and sequential
* searches are used.
*/
/*
* Enter a new hash index, after a new record has been inserted
*
* Do not call when a record has been modified (with no key change)
*/
static void inserthashindex(struct CACHE_HEADER *cache,
struct CACHED_GENERIC *current)
{
int h;
struct HASH_ENTRY *link;
struct HASH_ENTRY *first;
if (cache->dohash) {
h = cache->dohash(current);
if ((h >= 0) && (h < cache->max_hash)) {
/* get a free link and insert at top of hash list */
link = cache->free_hash;
if (link) {
cache->free_hash = link->next;
first = cache->first_hash[h];
if (first)
link->next = first;
else
link->next = NULL;
link->entry = current;
cache->first_hash[h] = link;
} else {
ntfs_log_error("No more hash entries,"
" cache %s hashing dropped\n",
cache->name);
cache->dohash = (cache_hash)NULL;
}
} else {
ntfs_log_error("Illegal hash value,"
" cache %s hashing dropped\n",
cache->name);
cache->dohash = (cache_hash)NULL;
}
}
}
/*
* Drop a hash index when a record is about to be deleted
*/
static void drophashindex(struct CACHE_HEADER *cache,
const struct CACHED_GENERIC *current, int hash)
{
struct HASH_ENTRY *link;
struct HASH_ENTRY *previous;
if (cache->dohash) {
if ((hash >= 0) && (hash < cache->max_hash)) {
/* find the link and unlink */
link = cache->first_hash[hash];
previous = (struct HASH_ENTRY*)NULL;
while (link && (link->entry != current)) {
previous = link;
link = link->next;
}
if (link) {
if (previous)
previous->next = link->next;
else
cache->first_hash[hash] = link->next;
link->next = cache->free_hash;
cache->free_hash = link;
} else {
ntfs_log_error("Bad hash list,"
" cache %s hashing dropped\n",
cache->name);
cache->dohash = (cache_hash)NULL;
}
} else {
ntfs_log_error("Illegal hash value,"
" cache %s hashing dropped\n",
cache->name);
cache->dohash = (cache_hash)NULL;
}
}
}
/*
* Fetch an entry from cache
*
* returns the cache entry, or NULL if not available
* The returned entry may be modified, but not freed
*/
struct CACHED_GENERIC *ntfs_fetch_cache(struct CACHE_HEADER *cache,
const struct CACHED_GENERIC *wanted, cache_compare compare)
{
struct CACHED_GENERIC *current;
struct CACHED_GENERIC *previous;
struct HASH_ENTRY *link;
int h;
current = (struct CACHED_GENERIC*)NULL;
if (cache) {
if (cache->dohash) {
/*
* When possible, use the hash table to
* locate the entry if present
*/
h = cache->dohash(wanted);
link = cache->first_hash[h];
while (link && compare(link->entry, wanted))
link = link->next;
if (link)
current = link->entry;
}
if (!cache->dohash) {
/*
* Search sequentially in LRU list if no hash table
* or if hashing has just failed
*/
current = cache->most_recent_entry;
while (current
&& compare(current, wanted)) {
current = current->next;
}
}
if (current) {
previous = current->previous;
cache->hits++;
if (previous) {
/*
* found and not at head of list, unlink from current
* position and relink as head of list
*/
previous->next = current->next;
if (current->next)
current->next->previous
= current->previous;
else
cache->oldest_entry
= current->previous;
current->next = cache->most_recent_entry;
current->previous
= (struct CACHED_GENERIC*)NULL;
cache->most_recent_entry->previous = current;
cache->most_recent_entry = current;
}
}
cache->reads++;
}
return (current);
}
/*
* Enter an inode number into cache
* returns the cache entry or NULL if not possible
*/
struct CACHED_GENERIC *ntfs_enter_cache(struct CACHE_HEADER *cache,
const struct CACHED_GENERIC *item,
cache_compare compare)
{
struct CACHED_GENERIC *current;
struct CACHED_GENERIC *before;
struct HASH_ENTRY *link;
int h;
current = (struct CACHED_GENERIC*)NULL;
if (cache) {
if (cache->dohash) {
/*
* When possible, use the hash table to
* find out whether the entry if present
*/
h = cache->dohash(item);
link = cache->first_hash[h];
while (link && compare(link->entry, item))
link = link->next;
if (link) {
current = link->entry;
}
}
if (!cache->dohash) {
/*
* Search sequentially in LRU list to locate the end,
* and find out whether the entry is already in list
* As we normally go to the end, no statistics is
* kept.
*/
current = cache->most_recent_entry;
while (current
&& compare(current, item)) {
current = current->next;
}
}
if (!current) {
/*
* Not in list, get a free entry or reuse the
* last entry, and relink as head of list
* Note : we assume at least three entries, so
* before, previous and first are different when
* an entry is reused.
*/
if (cache->free_entry) {
current = cache->free_entry;
cache->free_entry = cache->free_entry->next;
if (item->varsize) {
current->variable = ntfs_malloc(
item->varsize);
} else
current->variable = (void*)NULL;
current->varsize = item->varsize;
if (!cache->oldest_entry)
cache->oldest_entry = current;
} else {
/* reusing the oldest entry */
current = cache->oldest_entry;
before = current->previous;
before->next = (struct CACHED_GENERIC*)NULL;
if (cache->dohash)
drophashindex(cache,current,
cache->dohash(current));
if (cache->dofree)
cache->dofree(current);
cache->oldest_entry = current->previous;
if (item->varsize) {
if (current->varsize)
current->variable = realloc(
current->variable,
item->varsize);
else
current->variable = ntfs_malloc(
item->varsize);
} else {
if (current->varsize)
free(current->variable);
current->variable = (void*)NULL;
}
current->varsize = item->varsize;
}
current->next = cache->most_recent_entry;
current->previous = (struct CACHED_GENERIC*)NULL;
if (cache->most_recent_entry)
cache->most_recent_entry->previous = current;
cache->most_recent_entry = current;
memcpy(current->fixed, item->fixed, cache->fixed_size);
if (item->varsize) {
if (current->variable) {
memcpy(current->variable,
item->variable, item->varsize);
} else {
/*
* no more memory for variable part
* recycle entry in free list
* not an error, just uncacheable
*/
cache->most_recent_entry = current->next;
current->next = cache->free_entry;
cache->free_entry = current;
current = (struct CACHED_GENERIC*)NULL;
}
} else {
current->variable = (void*)NULL;
current->varsize = 0;
}
if (cache->dohash && current)
inserthashindex(cache,current);
}
cache->writes++;
}
return (current);
}
/*
* Invalidate a cache entry
* The entry is moved to the free entry list
* A specific function may be called for entry deletion
*/
static void do_invalidate(struct CACHE_HEADER *cache,
struct CACHED_GENERIC *current, int flags)
{
struct CACHED_GENERIC *previous;
previous = current->previous;
if ((flags & CACHE_FREE) && cache->dofree)
cache->dofree(current);
/*
* Relink into free list
*/
if (current->next)
current->next->previous = current->previous;
else
cache->oldest_entry = current->previous;
if (previous)
previous->next = current->next;
else
cache->most_recent_entry = current->next;
current->next = cache->free_entry;
cache->free_entry = current;
if (current->variable)
free(current->variable);
current->varsize = 0;
}
/*
* Invalidate entries in cache
*
* Several entries may have to be invalidated (at least for inodes
* associated to directories which have been renamed), a different
* compare function may be provided to select entries to invalidate
*
* Returns the number of deleted entries, this can be used by
* the caller to signal a cache corruption if the entry was
* supposed to be found.
*/
int ntfs_invalidate_cache(struct CACHE_HEADER *cache,
const struct CACHED_GENERIC *item, cache_compare compare,
int flags)
{
struct CACHED_GENERIC *current;
struct CACHED_GENERIC *previous;
struct CACHED_GENERIC *next;
struct HASH_ENTRY *link;
int count;
int h;
current = (struct CACHED_GENERIC*)NULL;
count = 0;
if (cache) {
if (!(flags & CACHE_NOHASH) && cache->dohash) {
/*
* When possible, use the hash table to
* find out whether the entry if present
*/
h = cache->dohash(item);
link = cache->first_hash[h];
while (link) {
if (compare(link->entry, item))
link = link->next;
else {
current = link->entry;
link = link->next;
if (current) {
drophashindex(cache,current,h);
do_invalidate(cache,
current,flags);
count++;
}
}
}
}
if ((flags & CACHE_NOHASH) || !cache->dohash) {
/*
* Search sequentially in LRU list
*/
current = cache->most_recent_entry;
previous = (struct CACHED_GENERIC*)NULL;
while (current) {
if (!compare(current, item)) {
next = current->next;
if (cache->dohash)
drophashindex(cache,current,
cache->dohash(current));
do_invalidate(cache,current,flags);
current = next;
count++;
} else {
previous = current;
current = current->next;
}
}
}
}
return (count);
}
int ntfs_remove_cache(struct CACHE_HEADER *cache,
struct CACHED_GENERIC *item, int flags)
{
int count;
count = 0;
if (cache) {
if (cache->dohash)
drophashindex(cache,item,cache->dohash(item));
do_invalidate(cache,item,flags);
count++;
}
return (count);
}
/*
* Free memory allocated to a cache
*/
static void ntfs_free_cache(struct CACHE_HEADER *cache)
{
struct CACHED_GENERIC *entry;
if (cache) {
for (entry=cache->most_recent_entry; entry; entry=entry->next) {
if (cache->dofree)
cache->dofree(entry);
if (entry->variable)
free(entry->variable);
}
free(cache);
}
}
/*
* Create a cache
*
* Returns the cache header, or NULL if the cache could not be created
*/
static struct CACHE_HEADER *ntfs_create_cache(const char *name,
cache_free dofree, cache_hash dohash,
int full_item_size,
int item_count, int max_hash)
{
struct CACHE_HEADER *cache;
struct CACHED_GENERIC *pc;
struct CACHED_GENERIC *qc;
struct HASH_ENTRY *ph;
struct HASH_ENTRY *qh;
struct HASH_ENTRY **px;
size_t size;
int i;
size = sizeof(struct CACHE_HEADER) + item_count*full_item_size;
if (max_hash)
size += item_count*sizeof(struct HASH_ENTRY)
+ max_hash*sizeof(struct HASH_ENTRY*);
cache = (struct CACHE_HEADER*)ntfs_malloc(size);
if (cache) {
/* header */
cache->name = name;
cache->dofree = dofree;
if (dohash && max_hash) {
cache->dohash = dohash;
cache->max_hash = max_hash;
} else {
cache->dohash = (cache_hash)NULL;
cache->max_hash = 0;
}
cache->fixed_size = full_item_size - sizeof(struct CACHED_GENERIC);
cache->reads = 0;
cache->writes = 0;
cache->hits = 0;
/* chain the data entries, and mark an invalid entry */
cache->most_recent_entry = (struct CACHED_GENERIC*)NULL;
cache->oldest_entry = (struct CACHED_GENERIC*)NULL;
cache->free_entry = &cache->entry[0];
pc = &cache->entry[0];
for (i=0; i<(item_count - 1); i++) {
qc = (struct CACHED_GENERIC*)((char*)pc
+ full_item_size);
pc->next = qc;
pc->variable = (void*)NULL;
pc->varsize = 0;
pc = qc;
}
/* special for the last entry */
pc->next = (struct CACHED_GENERIC*)NULL;
pc->variable = (void*)NULL;
pc->varsize = 0;
if (max_hash) {
/* chain the hash entries */
ph = (struct HASH_ENTRY*)(((char*)pc) + full_item_size);
cache->free_hash = ph;
for (i=0; i<(item_count - 1); i++) {
qh = &ph[1];
ph->next = qh;
ph = qh;
}
/* special for the last entry */
if (item_count) {
ph->next = (struct HASH_ENTRY*)NULL;
}
/* create and initialize the hash indexes */
px = (struct HASH_ENTRY**)&ph[1];
cache->first_hash = px;
for (i=0; i<max_hash; i++)
px[i] = (struct HASH_ENTRY*)NULL;
} else {
cache->free_hash = (struct HASH_ENTRY*)NULL;
cache->first_hash = (struct HASH_ENTRY**)NULL;
}
}
return (cache);
}
/*
* Create all LRU caches
*
* No error return, if creation is not possible, cacheing will
* just be not available
*/
void ntfs_create_lru_caches(ntfs_volume *vol)
{
#if CACHE_INODE_SIZE
/* inode cache */
vol->xinode_cache = ntfs_create_cache("inode",(cache_free)NULL,
ntfs_dir_inode_hash, sizeof(struct CACHED_INODE),
CACHE_INODE_SIZE, 2*CACHE_INODE_SIZE);
#endif
#if CACHE_NIDATA_SIZE
/* idata cache */
vol->nidata_cache = ntfs_create_cache("nidata",
ntfs_inode_nidata_free, ntfs_inode_nidata_hash,
sizeof(struct CACHED_NIDATA),
CACHE_NIDATA_SIZE, 2*CACHE_NIDATA_SIZE);
#endif
#if CACHE_LOOKUP_SIZE
/* lookup cache */
vol->lookup_cache = ntfs_create_cache("lookup",
(cache_free)NULL, ntfs_dir_lookup_hash,
sizeof(struct CACHED_LOOKUP),
CACHE_LOOKUP_SIZE, 2*CACHE_LOOKUP_SIZE);
#endif
vol->securid_cache = ntfs_create_cache("securid",(cache_free)NULL,
(cache_hash)NULL,sizeof(struct CACHED_SECURID), CACHE_SECURID_SIZE, 0);
#if CACHE_LEGACY_SIZE
vol->legacy_cache = ntfs_create_cache("legacy",(cache_free)NULL,
(cache_hash)NULL, sizeof(struct CACHED_PERMISSIONS_LEGACY), CACHE_LEGACY_SIZE, 0);
#endif
}
/*
* Free all LRU caches
*/
void ntfs_free_lru_caches(ntfs_volume *vol)
{
#if CACHE_INODE_SIZE
ntfs_free_cache(vol->xinode_cache);
#endif
#if CACHE_NIDATA_SIZE
ntfs_free_cache(vol->nidata_cache);
#endif
#if CACHE_LOOKUP_SIZE
ntfs_free_cache(vol->lookup_cache);
#endif
ntfs_free_cache(vol->securid_cache);
#if CACHE_LEGACY_SIZE
ntfs_free_cache(vol->legacy_cache);
#endif
}