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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ext4_utils.h"
#include "backed_block.h"
#include <stdlib.h>
struct data_block {
u32 block;
u32 len;
u8 *data;
const char *filename;
off64_t offset;
struct data_block *next;
u32 fill_val;
u8 fill;
u8 pad1;
u16 pad2;
};
static struct data_block *data_blocks = NULL;
static struct data_block *last_used = NULL;
static void queue_db(struct data_block *new_db)
{
struct data_block *db;
if (data_blocks == NULL) {
data_blocks = new_db;
return;
}
if (data_blocks->block > new_db->block) {
new_db->next = data_blocks;
data_blocks = new_db;
return;
}
/* Optimization: blocks are mostly queued in sequence, so save the
pointer to the last db that was added, and start searching from
there if the next block number is higher */
if (last_used && new_db->block > last_used->block)
db = last_used;
else
db = data_blocks;
last_used = new_db;
for (; db->next && db->next->block < new_db->block; db = db->next)
;
if (db->next == NULL) {
db->next = new_db;
} else {
new_db->next = db->next;
db->next = new_db;
}
}
/* Queues a fill block of memory to be written to the specified data blocks */
void queue_fill_block(u32 fill_val, u32 len, u32 block)
{
struct data_block *db = malloc(sizeof(struct data_block));
if (db == NULL)
critical_error_errno("malloc");
db->block = block;
db->len = len;
db->fill = 1;
db->fill_val = fill_val;
db->data = NULL;
db->filename = NULL;
db->next = NULL;
queue_db(db);
}
/* Queues a block of memory to be written to the specified data blocks */
void queue_data_block(u8 *data, u32 len, u32 block)
{
struct data_block *db = malloc(sizeof(struct data_block));
if (db == NULL)
critical_error_errno("malloc");
db->block = block;
db->len = len;
db->data = data;
db->filename = NULL;
db->fill = 0;
db->next = NULL;
queue_db(db);
}
/* Queues a chunk of a file on disk to be written to the specified data blocks */
void queue_data_file(const char *filename, off64_t offset, u32 len,
u32 block)
{
struct data_block *db = malloc(sizeof(struct data_block));
if (db == NULL)
critical_error_errno("malloc");
db->block = block;
db->len = len;
db->filename = strdup(filename);
db->offset = offset;
db->data = NULL;
db->fill = 0;
db->next = NULL;
queue_db(db);
}
/* Iterates over the queued data blocks, calling data_func for each contiguous
data block, and file_func for each contiguous file block */
void for_each_data_block(data_block_callback_t data_func,
data_block_file_callback_t file_func,
data_block_fill_callback_t fill_func, void *priv)
{
struct data_block *db;
u32 last_block = 0;
for (db = data_blocks; db; db = db->next) {
if (db->block < last_block)
error("data blocks out of order: %u < %u", db->block, last_block);
last_block = db->block + DIV_ROUND_UP(db->len, info.block_size) - 1;
if (db->filename)
file_func(priv, (u64)db->block * info.block_size, db->filename, db->offset, db->len);
else if (db->fill)
fill_func(priv, (u64)db->block * info.block_size, db->fill_val, db->len);
else
data_func(priv, (u64)db->block * info.block_size, db->data, db->len);
}
}
/* Frees the memory used by the linked list of data blocks */
void free_data_blocks()
{
if (!data_blocks) return;
struct data_block *db = data_blocks;
while (db) {
struct data_block *next = db->next;
free((void*)db->filename);
// There used to be a free() of db->data here, but it
// made the function crash since queue_data_block() is
// sometimes passed pointers it can't take ownership of
// (like a pointer into the middle of an allocated
// block). It's not clear what the queue_data_block
// contract is supposed to be, but we'd rather leak
// memory than crash.
free(db);
db = next;
}
data_blocks = NULL;
last_used = NULL;
}
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