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Date: Fri, 14 Jan 2011 16:06:02 +1300
From: Charles Manning <cdhmanning@...il.com>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
akpm@...ux-foundation.org
Cc: Charles Manning <cdhmanning@...il.com>
Subject: [PATCH 03/10] Add yaffs2 file system: Checkpoint handing code
Signed-off-by: Charles Manning <cdhmanning@...il.com>
---
fs/yaffs2/yaffs_checkptrw.c | 407 +++++++++++++++++++++++++++++++++++++++++++
fs/yaffs2/yaffs_checkptrw.h | 33 ++++
2 files changed, 440 insertions(+), 0 deletions(-)
create mode 100644 fs/yaffs2/yaffs_checkptrw.c
create mode 100644 fs/yaffs2/yaffs_checkptrw.h
diff --git a/fs/yaffs2/yaffs_checkptrw.c b/fs/yaffs2/yaffs_checkptrw.c
new file mode 100644
index 0000000..711df13
--- /dev/null
+++ b/fs/yaffs2/yaffs_checkptrw.c
@@ -0,0 +1,407 @@
+/*
+ * 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@...ph1.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;
+ }
+ 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);
+}
diff --git a/fs/yaffs2/yaffs_checkptrw.h b/fs/yaffs2/yaffs_checkptrw.h
new file mode 100644
index 0000000..361c606
--- /dev/null
+++ b/fs/yaffs2/yaffs_checkptrw.h
@@ -0,0 +1,33 @@
+/*
+ * 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@...ph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CHECKPTRW_H__
+#define __YAFFS_CHECKPTRW_H__
+
+#include "yaffs_guts.h"
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing);
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes);
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes);
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum);
+
+int yaffs_checkpt_close(struct yaffs_dev *dev);
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev);
+
+#endif
--
1.7.1
--
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