- 根目录:
- fs
- yaffs2
- yaffs_checkptrw.c
/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
* Copyright (C) 2002-2010 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_checkptrw.h"
#include "yaffs_getblockinfo.h"
static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
{
int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"checkpt blocks_avail = %d", blocks_avail);
return (blocks_avail <= 0) ? 0 : 1;
}
static int yaffs_checkpt_erase(struct yaffs_dev *dev)
{
int i;
if (!dev->param.erase_fn)
return 0;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"checking blocks %d to %d",
dev->internal_start_block, dev->internal_end_block);
for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"erasing checkpt block %d", i);
dev->n_erasures++;
if (dev->param.
erase_fn(dev,
i - dev->block_offset /* realign */ )) {
bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
dev->n_erased_blocks++;
dev->n_free_chunks +=
dev->param.chunks_per_block;
} else {
dev->param.bad_block_fn(dev, i);
bi->block_state = YAFFS_BLOCK_STATE_DEAD;
}
}
}
dev->blocks_in_checkpt = 0;
return 1;
}
static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
{
int i;
int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"allocating checkpt block: erased %d reserved %d avail %d next %d ",
dev->n_erased_blocks, dev->param.n_reserved_blocks,
blocks_avail, dev->checkpt_next_block);
if (dev->checkpt_next_block >= 0 &&
dev->checkpt_next_block <= dev->internal_end_block &&
blocks_avail > 0) {
for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
i++) {
struct yaffs_block_info *bi =
yaffs_get_block_info(dev, i);
if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
dev->checkpt_next_block = i + 1;
dev->checkpt_cur_block = i;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"allocating checkpt block %d", i);
return;
}
}
}
yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
dev->checkpt_next_block = -1;
dev->checkpt_cur_block = -1;
}
static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
{
int i;
struct yaffs_ext_tags tags;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"find next checkpt block: start: blocks %d next %d",
dev->blocks_in_checkpt, dev->checkpt_next_block);
if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
i++) {
int chunk = i * dev->param.chunks_per_block;
int realigned_chunk = chunk - dev->chunk_offset;
dev->param.read_chunk_tags_fn(dev, realigned_chunk,
NULL, &tags);
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"find next checkpt block: search: block %d oid %d seq %d eccr %d",
i, tags.obj_id, tags.seq_number,
tags.ecc_result);
if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
/* Right kind of block */
dev->checkpt_next_block = tags.obj_id;
dev->checkpt_cur_block = i;
dev->checkpt_block_list[dev->
blocks_in_checkpt] = i;
dev->blocks_in_checkpt++;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"found checkpt block %d", i);
return;
}
}
yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
dev->checkpt_next_block = -1;
dev->checkpt_cur_block = -1;
}
int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
{
dev->checkpt_open_write = writing;
/* Got the functions we need? */
if (!dev->param.write_chunk_tags_fn ||
!dev->param.read_chunk_tags_fn ||
!dev->param.erase_fn || !dev->param.bad_block_fn)
return 0;
if (writing && !yaffs2_checkpt_space_ok(dev))
return 0;
if (!dev->checkpt_buffer)
dev->checkpt_buffer =
kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
if (!dev->checkpt_buffer)
return 0;
dev->checkpt_page_seq = 0;
dev->checkpt_byte_count = 0;
dev->checkpt_sum = 0;
dev->checkpt_xor = 0;
dev->checkpt_cur_block = -1;
dev->checkpt_cur_chunk = -1;
dev->checkpt_next_block = dev->internal_start_block;
/* Erase all the blocks in the checkpoint area */
if (writing) {
memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
dev->checkpt_byte_offs = 0;
return yaffs_checkpt_erase(dev);
} else {
int i;
/* Set to a value that will kick off a read */
dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
/* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
* going to be way more than we need */
dev->blocks_in_checkpt = 0;
dev->checkpt_max_blocks =
(dev->internal_end_block - dev->internal_start_block) / 16 +
2;
dev->checkpt_block_list =
kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
if (!dev->checkpt_block_list)
return 0;
for (i = 0; i < dev->checkpt_max_blocks; i++)
dev->checkpt_block_list[i] = -1;
}
return 1;
}
int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
{
u32 composite_sum;
composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xFF);
*sum = composite_sum;
return 1;
}
static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
{
int chunk;
int realigned_chunk;
struct yaffs_ext_tags tags;
if (dev->checkpt_cur_block < 0) {
yaffs2_checkpt_find_erased_block(dev);
dev->checkpt_cur_chunk = 0;
}
if (dev->checkpt_cur_block < 0)
return 0;
tags.is_deleted = 0;
tags.obj_id = dev->checkpt_next_block; /* Hint to next place to look */
tags.chunk_id = dev->checkpt_page_seq + 1;
tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
tags.n_bytes = dev->data_bytes_per_chunk;
if (dev->checkpt_cur_chunk == 0) {
/* First chunk we write for the block? Set block state to
checkpoint */
struct yaffs_block_info *bi =
yaffs_get_block_info(dev, dev->checkpt_cur_block);
bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
dev->blocks_in_checkpt++;
}
chunk =
dev->checkpt_cur_block * dev->param.chunks_per_block +
dev->checkpt_cur_chunk;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
tags.obj_id, tags.chunk_id);
realigned_chunk = chunk - dev->chunk_offset;
dev->n_page_writes++;
dev->param.write_chunk_tags_fn(dev, realigned_chunk,
dev->checkpt_buffer, &tags);
dev->checkpt_byte_offs = 0;
dev->checkpt_page_seq++;
dev->checkpt_cur_chunk++;
if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
dev->checkpt_cur_chunk = 0;
dev->checkpt_cur_block = -1;
}
memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
return 1;
}
int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
{
int i = 0;
int ok = 1;
u8 *data_bytes = (u8 *) data;
if (!dev->checkpt_buffer)
return 0;
if (!dev->checkpt_open_write)
return -1;
while (i < n_bytes && ok) {
dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
dev->checkpt_sum += *data_bytes;
dev->checkpt_xor ^= *data_bytes;
dev->checkpt_byte_offs++;
i++;
data_bytes++;
dev->checkpt_byte_count++;
if (dev->checkpt_byte_offs < 0 ||
dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
ok = yaffs2_checkpt_flush_buffer(dev);
}
return i;
}
int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
{
int i = 0;
int ok = 1;
struct yaffs_ext_tags tags;
int chunk;
int realigned_chunk;
u8 *data_bytes = (u8 *) data;
if (!dev->checkpt_buffer)
return 0;
if (dev->checkpt_open_write)
return -1;
while (i < n_bytes && ok) {
if (dev->checkpt_byte_offs < 0 ||
dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
if (dev->checkpt_cur_block < 0) {
yaffs2_checkpt_find_block(dev);
dev->checkpt_cur_chunk = 0;
}
if (dev->checkpt_cur_block < 0)
ok = 0;
else {
chunk = dev->checkpt_cur_block *
dev->param.chunks_per_block +
dev->checkpt_cur_chunk;
realigned_chunk = chunk - dev->chunk_offset;
dev->n_page_reads++;
/* read in the next chunk */
dev->param.read_chunk_tags_fn(dev,
realigned_chunk,
dev->
checkpt_buffer,
&tags);
if (tags.chunk_id != (dev->checkpt_page_seq + 1)
|| tags.ecc_result > YAFFS_ECC_RESULT_FIXED
|| tags.seq_number !=
YAFFS_SEQUENCE_CHECKPOINT_DATA)
ok = 0;
dev->checkpt_byte_offs = 0;
dev->checkpt_page_seq++;
dev->checkpt_cur_chunk++;
if (dev->checkpt_cur_chunk >=
dev->param.chunks_per_block)
dev->checkpt_cur_block = -1;
}
}
if (ok) {
*data_bytes =
dev->checkpt_buffer[dev->checkpt_byte_offs];
dev->checkpt_sum += *data_bytes;
dev->checkpt_xor ^= *data_bytes;
dev->checkpt_byte_offs++;
i++;
data_bytes++;
dev->checkpt_byte_count++;
}
}
return i;
}
int yaffs_checkpt_close(struct yaffs_dev *dev)
{
if (dev->checkpt_open_write) {
if (dev->checkpt_byte_offs != 0)
yaffs2_checkpt_flush_buffer(dev);
} else if (dev->checkpt_block_list) {
int i;
for (i = 0;
i < dev->blocks_in_checkpt
&& dev->checkpt_block_list[i] >= 0; i++) {
int blk = dev->checkpt_block_list[i];
struct yaffs_block_info *bi = NULL;
if (dev->internal_start_block <= blk
&& blk <= dev->internal_end_block)
bi = yaffs_get_block_info(dev, blk);
if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
else {
/* Todo this looks odd... */
}
}
kfree(dev->checkpt_block_list);
dev->checkpt_block_list = NULL;
}
dev->n_free_chunks -=
dev->blocks_in_checkpt * dev->param.chunks_per_block;
dev->n_erased_blocks -= dev->blocks_in_checkpt;
yaffs_trace(YAFFS_TRACE_CHECKPOINT,"checkpoint byte count %d",
dev->checkpt_byte_count);
if (dev->checkpt_buffer) {
/* free the buffer */
kfree(dev->checkpt_buffer);
dev->checkpt_buffer = NULL;
return 1;
} else {
return 0;
}
}
int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
{
/* Erase the checkpoint data */
yaffs_trace(YAFFS_TRACE_CHECKPOINT,
"checkpoint invalidate of %d blocks",
dev->blocks_in_checkpt);
return yaffs_checkpt_erase(dev);
}