fs/yaffs2/yaffs_summary.c - github/trini/u-boot - Gitiles

 /*
  * 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.
  */

 /* Summaries write the useful part of the tags for the chunks in a block into an
  * an array which is written to the last n chunks of the block.
  * Reading the summaries gives all the tags for the block in one read. Much
  * faster.
  *
  * Chunks holding summaries are marked with tags making it look like
  * they are part of a fake file.
  *
  * The summary could also be used during gc.
  *
  */

 #include "yaffs_summary.h"
 #include "yaffs_packedtags2.h"
 #include "yaffs_nand.h"
 #include "yaffs_getblockinfo.h"
 #include "yaffs_bitmap.h"

 /*
  * The summary is built up in an array of summary tags.
  * This gets written to the last one or two (maybe more) chunks in a block.
  * A summary header is written as the first part of each chunk of summary data.
  * The summary header must match or the summary is rejected.
  */

 /* Summary tags don't need the sequence number because that is redundant. */
 struct yaffs_summary_tags {
 	unsigned obj_id;
 	unsigned chunk_id;
 	unsigned n_bytes;
 };

 /* Summary header */
 struct yaffs_summary_header {
 	unsigned version;	/* Must match current version */
 	unsigned block;		/* Must be this block */
 	unsigned seq;		/* Must be this sequence number */
 	unsigned sum;		/* Just add up all the bytes in the tags */
 };


 static void yaffs_summary_clear(struct yaffs_dev *dev)
 {
 	if (!dev->sum_tags)
 		return;
 	memset(dev->sum_tags, 0, dev->chunks_per_summary *
 		sizeof(struct yaffs_summary_tags));
 }


 void yaffs_summary_deinit(struct yaffs_dev *dev)
 {
 	kfree(dev->sum_tags);
 	dev->sum_tags = NULL;
 	kfree(dev->gc_sum_tags);
 	dev->gc_sum_tags = NULL;
 	dev->chunks_per_summary = 0;
 }

 int yaffs_summary_init(struct yaffs_dev *dev)
 {
 	int sum_bytes;
 	int chunks_used; /* Number of chunks used by summary */
 	int sum_tags_bytes;

 	sum_bytes = dev->param.chunks_per_block *
 			sizeof(struct yaffs_summary_tags);

 	chunks_used = (sum_bytes + dev->data_bytes_per_chunk - 1)/
 			(dev->data_bytes_per_chunk -
 				sizeof(struct yaffs_summary_header));

 	dev->chunks_per_summary = dev->param.chunks_per_block - chunks_used;
 	sum_tags_bytes = sizeof(struct yaffs_summary_tags) *
 				dev->chunks_per_summary;
 	dev->sum_tags = kmalloc(sum_tags_bytes, GFP_NOFS);
 	dev->gc_sum_tags = kmalloc(sum_tags_bytes, GFP_NOFS);
 	if (!dev->sum_tags || !dev->gc_sum_tags) {
 		yaffs_summary_deinit(dev);
 		return YAFFS_FAIL;
 	}

 	yaffs_summary_clear(dev);

 	return YAFFS_OK;
 }

 static unsigned yaffs_summary_sum(struct yaffs_dev *dev)
 {
 	u8 *sum_buffer = (u8 *)dev->sum_tags;
 	int i;
 	unsigned sum = 0;

 	i = sizeof(struct yaffs_summary_tags) *
 				dev->chunks_per_summary;
 	while (i > 0) {
 		sum += *sum_buffer;
 		sum_buffer++;
 		i--;
 	}

 	return sum;
 }

 static int yaffs_summary_write(struct yaffs_dev *dev, int blk)
 {
 	struct yaffs_ext_tags tags;
 	u8 *buffer;
 	u8 *sum_buffer = (u8 *)dev->sum_tags;
 	int n_bytes;
 	int chunk_in_nand;
 	int chunk_in_block;
 	int result;
 	int this_tx;
 	struct yaffs_summary_header hdr;
 	int sum_bytes_per_chunk = dev->data_bytes_per_chunk - sizeof(hdr);
 	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);

 	buffer = yaffs_get_temp_buffer(dev);
 	n_bytes = sizeof(struct yaffs_summary_tags) *
 				dev->chunks_per_summary;
 	memset(&tags, 0, sizeof(struct yaffs_ext_tags));
 	tags.obj_id = YAFFS_OBJECTID_SUMMARY;
 	tags.chunk_id = 1;
 	chunk_in_block = dev->chunks_per_summary;
 	chunk_in_nand = dev->alloc_block * dev->param.chunks_per_block +
 						dev->chunks_per_summary;
 	hdr.version = YAFFS_SUMMARY_VERSION;
 	hdr.block = blk;
 	hdr.seq = bi->seq_number;
 	hdr.sum = yaffs_summary_sum(dev);

 	do {
 		this_tx = n_bytes;
 		if (this_tx > sum_bytes_per_chunk)
 			this_tx = sum_bytes_per_chunk;
 		memcpy(buffer, &hdr, sizeof(hdr));
 		memcpy(buffer + sizeof(hdr), sum_buffer, this_tx);
 		tags.n_bytes = this_tx + sizeof(hdr);
 		result = yaffs_wr_chunk_tags_nand(dev, chunk_in_nand,
 						buffer, &tags);

 		if (result != YAFFS_OK)
 			break;
 		yaffs_set_chunk_bit(dev, blk, chunk_in_block);
 		bi->pages_in_use++;
 		dev->n_free_chunks--;

 		n_bytes -= this_tx;
 		sum_buffer += this_tx;
 		chunk_in_nand++;
 		chunk_in_block++;
 		tags.chunk_id++;
 	} while (result == YAFFS_OK && n_bytes > 0);
 	yaffs_release_temp_buffer(dev, buffer);


 	if (result == YAFFS_OK)
 		bi->has_summary = 1;


 	return result;
 }

 int yaffs_summary_read(struct yaffs_dev *dev,
 			struct yaffs_summary_tags *st,
 			int blk)
 {
 	struct yaffs_ext_tags tags;
 	u8 *buffer;
 	u8 *sum_buffer = (u8 *)st;
 	int n_bytes;
 	int chunk_id;
 	int chunk_in_nand;
 	int chunk_in_block;
 	int result;
 	int this_tx;
 	struct yaffs_summary_header hdr;
 	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
 	int sum_bytes_per_chunk = dev->data_bytes_per_chunk - sizeof(hdr);

 	buffer = yaffs_get_temp_buffer(dev);
 	n_bytes = sizeof(struct yaffs_summary_tags) * dev->chunks_per_summary;
 	chunk_in_block = dev->chunks_per_summary;
 	chunk_in_nand = blk * dev->param.chunks_per_block +
 							dev->chunks_per_summary;
 	chunk_id = 1;
 	do {
 		this_tx = n_bytes;
 		if (this_tx > sum_bytes_per_chunk)
 			this_tx = sum_bytes_per_chunk;
 		result = yaffs_rd_chunk_tags_nand(dev, chunk_in_nand,
 						buffer, &tags);

 		if (tags.chunk_id != chunk_id ||
 			tags.obj_id != YAFFS_OBJECTID_SUMMARY ||
 			tags.chunk_used == 0 ||
 			tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
 			tags.n_bytes != (this_tx + sizeof(hdr)))
 				result = YAFFS_FAIL;
 		if (result != YAFFS_OK)
 			break;

 		if (st == dev->sum_tags) {
 			/* If we're scanning then update the block info */
 			yaffs_set_chunk_bit(dev, blk, chunk_in_block);
 			bi->pages_in_use++;
 		}
 		memcpy(&hdr, buffer, sizeof(hdr));
 		memcpy(sum_buffer, buffer + sizeof(hdr), this_tx);
 		n_bytes -= this_tx;
 		sum_buffer += this_tx;
 		chunk_in_nand++;
 		chunk_in_block++;
 		chunk_id++;
 	} while (result == YAFFS_OK && n_bytes > 0);
 	yaffs_release_temp_buffer(dev, buffer);

 	if (result == YAFFS_OK) {
 		/* Verify header */
 		if (hdr.version != YAFFS_SUMMARY_VERSION ||
 		    hdr.block != blk ||
 		    hdr.seq != bi->seq_number ||
 		    hdr.sum != yaffs_summary_sum(dev))
 			result = YAFFS_FAIL;
 	}

 	if (st == dev->sum_tags && result == YAFFS_OK)
 		bi->has_summary = 1;

 	return result;
 }

 int yaffs_summary_add(struct yaffs_dev *dev,
 			struct yaffs_ext_tags *tags,
 			int chunk_in_nand)
 {
 	struct yaffs_packed_tags2_tags_only tags_only;
 	struct yaffs_summary_tags *sum_tags;
 	int block_in_nand = chunk_in_nand / dev->param.chunks_per_block;
 	int chunk_in_block = chunk_in_nand % dev->param.chunks_per_block;

 	if (!dev->sum_tags)
 		return YAFFS_OK;

 	if (chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
 		yaffs_pack_tags2_tags_only(&tags_only, tags);
 		sum_tags = &dev->sum_tags[chunk_in_block];
 		sum_tags->chunk_id = tags_only.chunk_id;
 		sum_tags->n_bytes = tags_only.n_bytes;
 		sum_tags->obj_id = tags_only.obj_id;

 		if (chunk_in_block == dev->chunks_per_summary - 1) {
 			/* Time to write out the summary */
 			yaffs_summary_write(dev, block_in_nand);
 			yaffs_summary_clear(dev);
 			yaffs_skip_rest_of_block(dev);
 		}
 	}
 	return YAFFS_OK;
 }

 int yaffs_summary_fetch(struct yaffs_dev *dev,
 			struct yaffs_ext_tags *tags,
 			int chunk_in_block)
 {
 	struct yaffs_packed_tags2_tags_only tags_only;
 	struct yaffs_summary_tags *sum_tags;
 	if (chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
 		sum_tags = &dev->sum_tags[chunk_in_block];
 		tags_only.chunk_id = sum_tags->chunk_id;
 		tags_only.n_bytes = sum_tags->n_bytes;
 		tags_only.obj_id = sum_tags->obj_id;
 		yaffs_unpack_tags2_tags_only(tags, &tags_only);
 		return YAFFS_OK;
 	}
 	return YAFFS_FAIL;
 }

 void yaffs_summary_gc(struct yaffs_dev *dev, int blk)
 {
 	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
 	int i;

 	if (!bi->has_summary)
 		return;

 	for (i = dev->chunks_per_summary;
 	     i < dev->param.chunks_per_block;
 	     i++) {
 		if (yaffs_check_chunk_bit(dev, blk, i)) {
 			yaffs_clear_chunk_bit(dev, blk, i);
 			bi->pages_in_use--;
 			dev->n_free_chunks++;
 		}
 	}
 }
	/*
	* 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.
	*/

	/* Summaries write the useful part of the tags for the chunks in a block into an
	* an array which is written to the last n chunks of the block.
	* Reading the summaries gives all the tags for the block in one read. Much
	* faster.
	*
	* Chunks holding summaries are marked with tags making it look like
	* they are part of a fake file.
	*
	* The summary could also be used during gc.
	*
	*/

	#include "yaffs_summary.h"
	#include "yaffs_packedtags2.h"
	#include "yaffs_nand.h"
	#include "yaffs_getblockinfo.h"
	#include "yaffs_bitmap.h"

	/*
	* The summary is built up in an array of summary tags.
	* This gets written to the last one or two (maybe more) chunks in a block.
	* A summary header is written as the first part of each chunk of summary data.
	* The summary header must match or the summary is rejected.
	*/

	/* Summary tags don't need the sequence number because that is redundant. */
	struct yaffs_summary_tags {
	unsigned obj_id;
	unsigned chunk_id;
	unsigned n_bytes;
	};

	/* Summary header */
	struct yaffs_summary_header {
	unsigned version; /* Must match current version */
	unsigned block; /* Must be this block */
	unsigned seq; /* Must be this sequence number */
	unsigned sum; /* Just add up all the bytes in the tags */
	};


	static void yaffs_summary_clear(struct yaffs_dev *dev)
	{
	if (!dev->sum_tags)
	return;
	memset(dev->sum_tags, 0, dev->chunks_per_summary *
	sizeof(struct yaffs_summary_tags));
	}


	void yaffs_summary_deinit(struct yaffs_dev *dev)
	{
	kfree(dev->sum_tags);
	dev->sum_tags = NULL;
	kfree(dev->gc_sum_tags);
	dev->gc_sum_tags = NULL;
	dev->chunks_per_summary = 0;
	}

	int yaffs_summary_init(struct yaffs_dev *dev)
	{
	int sum_bytes;
	int chunks_used; /* Number of chunks used by summary */
	int sum_tags_bytes;

	sum_bytes = dev->param.chunks_per_block *
	sizeof(struct yaffs_summary_tags);

	chunks_used = (sum_bytes + dev->data_bytes_per_chunk - 1)/
	(dev->data_bytes_per_chunk -
	sizeof(struct yaffs_summary_header));

	dev->chunks_per_summary = dev->param.chunks_per_block - chunks_used;
	sum_tags_bytes = sizeof(struct yaffs_summary_tags) *
	dev->chunks_per_summary;
	dev->sum_tags = kmalloc(sum_tags_bytes, GFP_NOFS);
	dev->gc_sum_tags = kmalloc(sum_tags_bytes, GFP_NOFS);
	if (!dev->sum_tags \|\| !dev->gc_sum_tags) {
	yaffs_summary_deinit(dev);
	return YAFFS_FAIL;
	}

	yaffs_summary_clear(dev);

	return YAFFS_OK;
	}

	static unsigned yaffs_summary_sum(struct yaffs_dev *dev)
	{
	u8 sum_buffer = (u8 )dev->sum_tags;
	int i;
	unsigned sum = 0;

	i = sizeof(struct yaffs_summary_tags) *
	dev->chunks_per_summary;
	while (i > 0) {
	sum += *sum_buffer;
	sum_buffer++;
	i--;
	}

	return sum;
	}

	static int yaffs_summary_write(struct yaffs_dev *dev, int blk)
	{
	struct yaffs_ext_tags tags;
	u8 *buffer;
	u8 sum_buffer = (u8 )dev->sum_tags;
	int n_bytes;
	int chunk_in_nand;
	int chunk_in_block;
	int result;
	int this_tx;
	struct yaffs_summary_header hdr;
	int sum_bytes_per_chunk = dev->data_bytes_per_chunk - sizeof(hdr);
	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);

	buffer = yaffs_get_temp_buffer(dev);
	n_bytes = sizeof(struct yaffs_summary_tags) *
	dev->chunks_per_summary;
	memset(&tags, 0, sizeof(struct yaffs_ext_tags));
	tags.obj_id = YAFFS_OBJECTID_SUMMARY;
	tags.chunk_id = 1;
	chunk_in_block = dev->chunks_per_summary;
	chunk_in_nand = dev->alloc_block * dev->param.chunks_per_block +
	dev->chunks_per_summary;
	hdr.version = YAFFS_SUMMARY_VERSION;
	hdr.block = blk;
	hdr.seq = bi->seq_number;
	hdr.sum = yaffs_summary_sum(dev);

	do {
	this_tx = n_bytes;
	if (this_tx > sum_bytes_per_chunk)
	this_tx = sum_bytes_per_chunk;
	memcpy(buffer, &hdr, sizeof(hdr));
	memcpy(buffer + sizeof(hdr), sum_buffer, this_tx);
	tags.n_bytes = this_tx + sizeof(hdr);
	result = yaffs_wr_chunk_tags_nand(dev, chunk_in_nand,
	buffer, &tags);

	if (result != YAFFS_OK)
	break;
	yaffs_set_chunk_bit(dev, blk, chunk_in_block);
	bi->pages_in_use++;
	dev->n_free_chunks--;

	n_bytes -= this_tx;
	sum_buffer += this_tx;
	chunk_in_nand++;
	chunk_in_block++;
	tags.chunk_id++;
	} while (result == YAFFS_OK && n_bytes > 0);
	yaffs_release_temp_buffer(dev, buffer);


	if (result == YAFFS_OK)
	bi->has_summary = 1;


	return result;
	}

	int yaffs_summary_read(struct yaffs_dev *dev,
	struct yaffs_summary_tags *st,
	int blk)
	{
	struct yaffs_ext_tags tags;
	u8 *buffer;
	u8 sum_buffer = (u8 )st;
	int n_bytes;
	int chunk_id;
	int chunk_in_nand;
	int chunk_in_block;
	int result;
	int this_tx;
	struct yaffs_summary_header hdr;
	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
	int sum_bytes_per_chunk = dev->data_bytes_per_chunk - sizeof(hdr);

	buffer = yaffs_get_temp_buffer(dev);
	n_bytes = sizeof(struct yaffs_summary_tags) * dev->chunks_per_summary;
	chunk_in_block = dev->chunks_per_summary;
	chunk_in_nand = blk * dev->param.chunks_per_block +
	dev->chunks_per_summary;
	chunk_id = 1;
	do {
	this_tx = n_bytes;
	if (this_tx > sum_bytes_per_chunk)
	this_tx = sum_bytes_per_chunk;
	result = yaffs_rd_chunk_tags_nand(dev, chunk_in_nand,
	buffer, &tags);

	if (tags.chunk_id != chunk_id \|\|
	tags.obj_id != YAFFS_OBJECTID_SUMMARY \|\|
	tags.chunk_used == 0 \|\|
	tags.ecc_result > YAFFS_ECC_RESULT_FIXED \|\|
	tags.n_bytes != (this_tx + sizeof(hdr)))
	result = YAFFS_FAIL;
	if (result != YAFFS_OK)
	break;

	if (st == dev->sum_tags) {
	/* If we're scanning then update the block info */
	yaffs_set_chunk_bit(dev, blk, chunk_in_block);
	bi->pages_in_use++;
	}
	memcpy(&hdr, buffer, sizeof(hdr));
	memcpy(sum_buffer, buffer + sizeof(hdr), this_tx);
	n_bytes -= this_tx;
	sum_buffer += this_tx;
	chunk_in_nand++;
	chunk_in_block++;
	chunk_id++;
	} while (result == YAFFS_OK && n_bytes > 0);
	yaffs_release_temp_buffer(dev, buffer);

	if (result == YAFFS_OK) {
	/* Verify header */
	if (hdr.version != YAFFS_SUMMARY_VERSION \|\|
	hdr.block != blk \|\|
	hdr.seq != bi->seq_number \|\|
	hdr.sum != yaffs_summary_sum(dev))
	result = YAFFS_FAIL;
	}

	if (st == dev->sum_tags && result == YAFFS_OK)
	bi->has_summary = 1;

	return result;
	}

	int yaffs_summary_add(struct yaffs_dev *dev,
	struct yaffs_ext_tags *tags,
	int chunk_in_nand)
	{
	struct yaffs_packed_tags2_tags_only tags_only;
	struct yaffs_summary_tags *sum_tags;
	int block_in_nand = chunk_in_nand / dev->param.chunks_per_block;
	int chunk_in_block = chunk_in_nand % dev->param.chunks_per_block;

	if (!dev->sum_tags)
	return YAFFS_OK;

	if (chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
	yaffs_pack_tags2_tags_only(&tags_only, tags);
	sum_tags = &dev->sum_tags[chunk_in_block];
	sum_tags->chunk_id = tags_only.chunk_id;
	sum_tags->n_bytes = tags_only.n_bytes;
	sum_tags->obj_id = tags_only.obj_id;

	if (chunk_in_block == dev->chunks_per_summary - 1) {
	/* Time to write out the summary */
	yaffs_summary_write(dev, block_in_nand);
	yaffs_summary_clear(dev);
	yaffs_skip_rest_of_block(dev);
	}
	}
	return YAFFS_OK;
	}

	int yaffs_summary_fetch(struct yaffs_dev *dev,
	struct yaffs_ext_tags *tags,
	int chunk_in_block)
	{
	struct yaffs_packed_tags2_tags_only tags_only;
	struct yaffs_summary_tags *sum_tags;
	if (chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
	sum_tags = &dev->sum_tags[chunk_in_block];
	tags_only.chunk_id = sum_tags->chunk_id;
	tags_only.n_bytes = sum_tags->n_bytes;
	tags_only.obj_id = sum_tags->obj_id;
	yaffs_unpack_tags2_tags_only(tags, &tags_only);
	return YAFFS_OK;
	}
	return YAFFS_FAIL;
	}

	void yaffs_summary_gc(struct yaffs_dev *dev, int blk)
	{
	struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
	int i;

	if (!bi->has_summary)
	return;

	for (i = dev->chunks_per_summary;
	i < dev->param.chunks_per_block;
	i++) {
	if (yaffs_check_chunk_bit(dev, blk, i)) {
	yaffs_clear_chunk_bit(dev, blk, i);
	bi->pages_in_use--;
	dev->n_free_chunks++;
	}
	}
	}