openwrtv3/target/linux/generic/files/fs/yaffs2/yaffs_allocator.c

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/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
* Copyright (C) 2002-2011 Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "yaffs_allocator.h"
#include "yaffs_guts.h"
#include "yaffs_trace.h"
#include "yportenv.h"
/*
* Each entry in yaffs_tnode_list and yaffs_obj_list hold blocks
* of approx 100 objects that are themn allocated singly.
* This is basically a simplified slab allocator.
*
* We don't use the Linux slab allocator because slab does not allow
* us to dump all the objects in one hit when we do a umount and tear
* down all the tnodes and objects. slab requires that we first free
* the individual objects.
*
* Once yaffs has been mainlined I shall try to motivate for a change
* to slab to provide the extra features we need here.
*/
struct yaffs_tnode_list {
struct yaffs_tnode_list *next;
struct yaffs_tnode *tnodes;
};
struct yaffs_obj_list {
struct yaffs_obj_list *next;
struct yaffs_obj *objects;
};
struct yaffs_allocator {
int n_tnodes_created;
struct yaffs_tnode *free_tnodes;
int n_free_tnodes;
struct yaffs_tnode_list *alloc_tnode_list;
int n_obj_created;
struct list_head free_objs;
int n_free_objects;
struct yaffs_obj_list *allocated_obj_list;
};
static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator =
(struct yaffs_allocator *)dev->allocator;
struct yaffs_tnode_list *tmp;
if (!allocator) {
BUG();
return;
}
while (allocator->alloc_tnode_list) {
tmp = allocator->alloc_tnode_list->next;
kfree(allocator->alloc_tnode_list->tnodes);
kfree(allocator->alloc_tnode_list);
allocator->alloc_tnode_list = tmp;
}
allocator->free_tnodes = NULL;
allocator->n_free_tnodes = 0;
allocator->n_tnodes_created = 0;
}
static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator = dev->allocator;
if (!allocator) {
BUG();
return;
}
allocator->alloc_tnode_list = NULL;
allocator->free_tnodes = NULL;
allocator->n_free_tnodes = 0;
allocator->n_tnodes_created = 0;
}
static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
{
struct yaffs_allocator *allocator =
(struct yaffs_allocator *)dev->allocator;
int i;
struct yaffs_tnode *new_tnodes;
u8 *mem;
struct yaffs_tnode *curr;
struct yaffs_tnode *next;
struct yaffs_tnode_list *tnl;
if (!allocator) {
BUG();
return YAFFS_FAIL;
}
if (n_tnodes < 1)
return YAFFS_OK;
/* make these things */
new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
mem = (u8 *) new_tnodes;
if (!new_tnodes) {
yaffs_trace(YAFFS_TRACE_ERROR,
"yaffs: Could not allocate Tnodes");
return YAFFS_FAIL;
}
/* New hookup for wide tnodes */
for (i = 0; i < n_tnodes - 1; i++) {
curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
curr->internal[0] = next;
}
curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
curr->internal[0] = allocator->free_tnodes;
allocator->free_tnodes = (struct yaffs_tnode *)mem;
allocator->n_free_tnodes += n_tnodes;
allocator->n_tnodes_created += n_tnodes;
/* Now add this bunch of tnodes to a list for freeing up.
* NB If we can't add this to the management list it isn't fatal
* but it just means we can't free this bunch of tnodes later.
*/
tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
if (!tnl) {
yaffs_trace(YAFFS_TRACE_ERROR,
"Could not add tnodes to management list");
return YAFFS_FAIL;
} else {
tnl->tnodes = new_tnodes;
tnl->next = allocator->alloc_tnode_list;
allocator->alloc_tnode_list = tnl;
}
yaffs_trace(YAFFS_TRACE_ALLOCATE, "Tnodes added");
return YAFFS_OK;
}
struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator =
(struct yaffs_allocator *)dev->allocator;
struct yaffs_tnode *tn = NULL;
if (!allocator) {
BUG();
return NULL;
}
/* If there are none left make more */
if (!allocator->free_tnodes)
yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
if (allocator->free_tnodes) {
tn = allocator->free_tnodes;
allocator->free_tnodes = allocator->free_tnodes->internal[0];
allocator->n_free_tnodes--;
}
return tn;
}
/* FreeTnode frees up a tnode and puts it back on the free list */
void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
{
struct yaffs_allocator *allocator = dev->allocator;
if (!allocator) {
BUG();
return;
}
if (tn) {
tn->internal[0] = allocator->free_tnodes;
allocator->free_tnodes = tn;
allocator->n_free_tnodes++;
}
dev->checkpoint_blocks_required = 0; /* force recalculation */
}
/*--------------- yaffs_obj alloaction ------------------------
*
* Free yaffs_objs are stored in a list using obj->siblings.
* The blocks of allocated objects are stored in a linked list.
*/
static void yaffs_init_raw_objs(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator = dev->allocator;
if (!allocator) {
BUG();
return;
}
allocator->allocated_obj_list = NULL;
INIT_LIST_HEAD(&allocator->free_objs);
allocator->n_free_objects = 0;
}
static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator = dev->allocator;
struct yaffs_obj_list *tmp;
if (!allocator) {
BUG();
return;
}
while (allocator->allocated_obj_list) {
tmp = allocator->allocated_obj_list->next;
kfree(allocator->allocated_obj_list->objects);
kfree(allocator->allocated_obj_list);
allocator->allocated_obj_list = tmp;
}
INIT_LIST_HEAD(&allocator->free_objs);
allocator->n_free_objects = 0;
allocator->n_obj_created = 0;
}
static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
{
struct yaffs_allocator *allocator = dev->allocator;
int i;
struct yaffs_obj *new_objs;
struct yaffs_obj_list *list;
if (!allocator) {
BUG();
return YAFFS_FAIL;
}
if (n_obj < 1)
return YAFFS_OK;
/* make these things */
new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
if (!new_objs || !list) {
kfree(new_objs);
new_objs = NULL;
kfree(list);
list = NULL;
yaffs_trace(YAFFS_TRACE_ALLOCATE,
"Could not allocate more objects");
return YAFFS_FAIL;
}
/* Hook them into the free list */
for (i = 0; i < n_obj; i++)
list_add(&new_objs[i].siblings, &allocator->free_objs);
allocator->n_free_objects += n_obj;
allocator->n_obj_created += n_obj;
/* Now add this bunch of Objects to a list for freeing up. */
list->objects = new_objs;
list->next = allocator->allocated_obj_list;
allocator->allocated_obj_list = list;
return YAFFS_OK;
}
struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
{
struct yaffs_obj *obj = NULL;
struct list_head *lh;
struct yaffs_allocator *allocator = dev->allocator;
if (!allocator) {
BUG();
return obj;
}
/* If there are none left make more */
if (list_empty(&allocator->free_objs))
yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
if (!list_empty(&allocator->free_objs)) {
lh = allocator->free_objs.next;
obj = list_entry(lh, struct yaffs_obj, siblings);
list_del_init(lh);
allocator->n_free_objects--;
}
return obj;
}
void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
{
struct yaffs_allocator *allocator = dev->allocator;
if (!allocator) {
BUG();
return;
}
/* Link into the free list. */
list_add(&obj->siblings, &allocator->free_objs);
allocator->n_free_objects++;
}
void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
{
if (!dev->allocator) {
BUG();
return;
}
yaffs_deinit_raw_tnodes(dev);
yaffs_deinit_raw_objs(dev);
kfree(dev->allocator);
dev->allocator = NULL;
}
void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
{
struct yaffs_allocator *allocator;
if (dev->allocator) {
BUG();
return;
}
allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
if (allocator) {
dev->allocator = allocator;
yaffs_init_raw_tnodes(dev);
yaffs_init_raw_objs(dev);
}
}