* published by the Free Software Foundation.
*/
-/* Summaries write all the tags for the chunks in a block into packed tags
- * (just the tags part - no ECC) in the last n chunks of the block.
+/* 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 chunks that hold the summary are removed from free space and are marked
- * as being in use.
+ * The summary could also be used during gc.
*
- * THa above might need to be revisited.
*/
#include "yaffs_summary.h"
#include "yaffs_getblockinfo.h"
#include "yaffs_bitmap.h"
-/* Summary tags don't need the sequence number becase that is redundant. */
+/*
+ * 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)
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;
+ (dev->data_bytes_per_chunk -
+ sizeof(struct yaffs_summary_header));
+
dev->chunks_per_summary = dev->param.chunks_per_block - chunks_used;
- dev->sum_tags = kmalloc(sizeof(struct yaffs_summary_tags) *
- dev->chunks_per_summary, GFP_NOFS);
- dev->gc_sum_tags = kmalloc(sizeof(struct yaffs_summary_tags) *
- dev->chunks_per_summary, GFP_NOFS);
+ 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) {
- kfree(dev->sum_tags);
- kfree(dev->gc_sum_tags);
+ yaffs_summary_deinit(dev);
return YAFFS_FAIL;
}
return YAFFS_OK;
}
-void yaffs_summary_deinit(struct yaffs_dev *dev)
+static unsigned yaffs_summary_sum(struct yaffs_dev *dev)
{
- kfree(dev->sum_tags);
- dev->sum_tags = NULL;
- kfree(dev->sum_tags);
- dev->sum_tags = NULL;
- dev->chunks_per_summary = 0;
+ 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)
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;
+ 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_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 > dev->data_bytes_per_chunk)
- this_tx = dev->data_bytes_per_chunk;
- memcpy(buffer, sum_buffer, this_tx);
- tags.n_bytes = this_tx;
+ 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);
chunk_in_nand++;
chunk_in_block++;
tags.chunk_id++;
-
- chunk_in_block++;
} while (result == YAFFS_OK && n_bytes > 0);
yaffs_release_temp_buffer(dev, buffer);
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);
+ int sum_tags_bytes;
+ sum_tags_bytes = sizeof(struct yaffs_summary_tags) *
+ dev->chunks_per_summary;
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_id = 1;
do {
this_tx = n_bytes;
- if(this_tx > dev->data_bytes_per_chunk)
- this_tx = dev->data_bytes_per_chunk;
+ 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);
tags.obj_id != YAFFS_OBJECTID_SUMMARY ||
tags.chunk_used == 0 ||
tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
- this_tx != tags.n_bytes)
+ tags.n_bytes != (this_tx + sizeof(hdr)))
result = YAFFS_FAIL;
if (result != YAFFS_OK)
break;
yaffs_set_chunk_bit(dev, blk, chunk_in_block);
bi->pages_in_use++;
}
-
- memcpy(sum_buffer, buffer, this_tx);
+ memcpy(&hdr, buffer, sizeof(hdr));
+ memcpy(sum_buffer, buffer + sizeof(hdr), this_tx);
n_bytes -= this_tx;
sum_buffer += this_tx;
chunk_in_nand++;
} 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)
if (!bi->has_summary)
return;
- for (i = dev->chunks_per_summary; i < dev->param.chunks_per_block; i++)
- yaffs_clear_chunk_bit(dev, blk, i);
+ 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++;
+ }
+ }
+
}
projects / yaffs2.git / blobdiff