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    Subject[PATCH 8/9] Add yaffs verification and version specific code.
    Date
    From: Charles Manning <cdhmanning@gmail.com>

    Adding yaffs2 file system.

    Signed-off-by: Charles Manning <cdhmanning@gmail.com>
    ---
    fs/yaffs2/yaffs_verify.c | 546 ++++++++++++++++
    fs/yaffs2/yaffs_verify.h | 43 ++
    fs/yaffs2/yaffs_yaffs1.c | 438 +++++++++++++
    fs/yaffs2/yaffs_yaffs1.h | 22 +
    fs/yaffs2/yaffs_yaffs2.c | 1618 ++++++++++++++++++++++++++++++++++++++++++++++
    fs/yaffs2/yaffs_yaffs2.h | 39 ++
    6 files changed, 2706 insertions(+), 0 deletions(-)
    create mode 100644 fs/yaffs2/yaffs_verify.c
    create mode 100644 fs/yaffs2/yaffs_verify.h
    create mode 100644 fs/yaffs2/yaffs_yaffs1.c
    create mode 100644 fs/yaffs2/yaffs_yaffs1.h
    create mode 100644 fs/yaffs2/yaffs_yaffs2.c
    create mode 100644 fs/yaffs2/yaffs_yaffs2.h

    diff --git a/fs/yaffs2/yaffs_verify.c b/fs/yaffs2/yaffs_verify.c
    new file mode 100644
    index 0000000..fee3a1e
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_verify.c
    @@ -0,0 +1,546 @@
    +/*
    + * 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_verify.h"
    +#include "yaffs_trace.h"
    +#include "yaffs_bitmap.h"
    +#include "yaffs_getblockinfo.h"
    +#include "yaffs_nand.h"
    +
    +int yaffs_skip_verification(struct yaffs_dev *dev)
    +{
    + dev = dev;
    + return !(yaffs_trace_mask &
    + (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
    +}
    +
    +static int yaffs_skip_full_verification(struct yaffs_dev *dev)
    +{
    + dev = dev;
    + return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_FULL));
    +}
    +
    +static int yaffs_skip_nand_verification(struct yaffs_dev *dev)
    +{
    + dev = dev;
    + return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_NAND));
    +}
    +
    +static const char *block_state_name[] = {
    + "Unknown",
    + "Needs scanning",
    + "Scanning",
    + "Empty",
    + "Allocating",
    + "Full",
    + "Dirty",
    + "Checkpoint",
    + "Collecting",
    + "Dead"
    +};
    +
    +void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi, int n)
    +{
    + int actually_used;
    + int in_use;
    +
    + if (yaffs_skip_verification(dev))
    + return;
    +
    + /* Report illegal runtime states */
    + if (bi->block_state >= YAFFS_NUMBER_OF_BLOCK_STATES)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Block %d has undefined state %d" TENDSTR), n,
    + bi->block_state));
    +
    + switch (bi->block_state) {
    + case YAFFS_BLOCK_STATE_UNKNOWN:
    + case YAFFS_BLOCK_STATE_SCANNING:
    + case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Block %d has bad run-state %s" TENDSTR), n,
    + block_state_name[bi->block_state]));
    + }
    +
    + /* Check pages in use and soft deletions are legal */
    +
    + actually_used = bi->pages_in_use - bi->soft_del_pages;
    +
    + if (bi->pages_in_use < 0
    + || bi->pages_in_use > dev->param.chunks_per_block
    + || bi->soft_del_pages < 0
    + || bi->soft_del_pages > dev->param.chunks_per_block
    + || actually_used < 0 || actually_used > dev->param.chunks_per_block)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR
    + ("Block %d has illegal values pages_in_used %d soft_del_pages %d"
    + TENDSTR), n, bi->pages_in_use, bi->soft_del_pages));
    +
    + /* Check chunk bitmap legal */
    + in_use = yaffs_count_chunk_bits(dev, n);
    + if (in_use != bi->pages_in_use)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR
    + ("Block %d has inconsistent values pages_in_use %d counted chunk bits %d"
    + TENDSTR), n, bi->pages_in_use, in_use));
    +
    +}
    +
    +void yaffs_verify_collected_blk(struct yaffs_dev *dev,
    + struct yaffs_block_info *bi, int n)
    +{
    + yaffs_verify_blk(dev, bi, n);
    +
    + /* After collection the block should be in the erased state */
    +
    + if (bi->block_state != YAFFS_BLOCK_STATE_COLLECTING &&
    + bi->block_state != YAFFS_BLOCK_STATE_EMPTY) {
    + T(YAFFS_TRACE_ERROR,
    + (TSTR
    + ("Block %d is in state %d after gc, should be erased"
    + TENDSTR), n, bi->block_state));
    + }
    +}
    +
    +void yaffs_verify_blocks(struct yaffs_dev *dev)
    +{
    + int i;
    + int state_count[YAFFS_NUMBER_OF_BLOCK_STATES];
    + int illegal_states = 0;
    +
    + if (yaffs_skip_verification(dev))
    + return;
    +
    + memset(state_count, 0, sizeof(state_count));
    +
    + for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
    + struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
    + yaffs_verify_blk(dev, bi, i);
    +
    + if (bi->block_state < YAFFS_NUMBER_OF_BLOCK_STATES)
    + state_count[bi->block_state]++;
    + else
    + illegal_states++;
    + }
    +
    + T(YAFFS_TRACE_VERIFY, (TSTR("" TENDSTR)));
    + T(YAFFS_TRACE_VERIFY, (TSTR("Block summary" TENDSTR)));
    +
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("%d blocks have illegal states" TENDSTR), illegal_states));
    + if (state_count[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Too many allocating blocks" TENDSTR)));
    +
    + for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("%s %d blocks" TENDSTR),
    + block_state_name[i], state_count[i]));
    +
    + if (dev->blocks_in_checkpt != state_count[YAFFS_BLOCK_STATE_CHECKPOINT])
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Checkpoint block count wrong dev %d count %d" TENDSTR),
    + dev->blocks_in_checkpt,
    + state_count[YAFFS_BLOCK_STATE_CHECKPOINT]));
    +
    + if (dev->n_erased_blocks != state_count[YAFFS_BLOCK_STATE_EMPTY])
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Erased block count wrong dev %d count %d" TENDSTR),
    + dev->n_erased_blocks, state_count[YAFFS_BLOCK_STATE_EMPTY]));
    +
    + if (state_count[YAFFS_BLOCK_STATE_COLLECTING] > 1)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Too many collecting blocks %d (max is 1)" TENDSTR),
    + state_count[YAFFS_BLOCK_STATE_COLLECTING]));
    +
    + T(YAFFS_TRACE_VERIFY, (TSTR("" TENDSTR)));
    +
    +}
    +
    +/*
    + * Verify the object header. oh must be valid, but obj and tags may be NULL in which
    + * case those tests will not be performed.
    + */
    +void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
    + struct yaffs_ext_tags *tags, int parent_check)
    +{
    + if (obj && yaffs_skip_verification(obj->my_dev))
    + return;
    +
    + if (!(tags && obj && oh)) {
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Verifying object header tags %p obj %p oh %p" TENDSTR),
    + tags, obj, oh));
    + return;
    + }
    +
    + if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
    + oh->type > YAFFS_OBJECT_TYPE_MAX)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d header type is illegal value 0x%x" TENDSTR),
    + tags->obj_id, oh->type));
    +
    + if (tags->obj_id != obj->obj_id)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d header mismatch obj_id %d" TENDSTR),
    + tags->obj_id, obj->obj_id));
    +
    + /*
    + * Check that the object's parent ids match if parent_check requested.
    + *
    + * Tests do not apply to the root object.
    + */
    +
    + if (parent_check && tags->obj_id > 1 && !obj->parent)
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR
    + ("Obj %d header mismatch parent_id %d obj->parent is NULL"
    + TENDSTR), tags->obj_id, oh->parent_obj_id));
    +
    + if (parent_check && obj->parent &&
    + oh->parent_obj_id != obj->parent->obj_id &&
    + (oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED ||
    + obj->parent->obj_id != YAFFS_OBJECTID_DELETED))
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR
    + ("Obj %d header mismatch parent_id %d parent_obj_id %d"
    + TENDSTR), tags->obj_id, oh->parent_obj_id,
    + obj->parent->obj_id));
    +
    + if (tags->obj_id > 1 && oh->name[0] == 0) /* Null name */
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d header name is NULL" TENDSTR), obj->obj_id));
    +
    + if (tags->obj_id > 1 && ((u8) (oh->name[0])) == 0xff) /* Trashed name */
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d header name is 0xFF" TENDSTR), obj->obj_id));
    +}
    +
    +void yaffs_verify_file(struct yaffs_obj *obj)
    +{
    + int required_depth;
    + int actual_depth;
    + u32 last_chunk;
    + u32 x;
    + u32 i;
    + struct yaffs_dev *dev;
    + struct yaffs_ext_tags tags;
    + struct yaffs_tnode *tn;
    + u32 obj_id;
    +
    + if (!obj)
    + return;
    +
    + if (yaffs_skip_verification(obj->my_dev))
    + return;
    +
    + dev = obj->my_dev;
    + obj_id = obj->obj_id;
    +
    + /* Check file size is consistent with tnode depth */
    + last_chunk =
    + obj->variant.file_variant.file_size / dev->data_bytes_per_chunk + 1;
    + x = last_chunk >> YAFFS_TNODES_LEVEL0_BITS;
    + required_depth = 0;
    + while (x > 0) {
    + x >>= YAFFS_TNODES_INTERNAL_BITS;
    + required_depth++;
    + }
    +
    + actual_depth = obj->variant.file_variant.top_level;
    +
    + /* Check that the chunks in the tnode tree are all correct.
    + * We do this by scanning through the tnode tree and
    + * checking the tags for every chunk match.
    + */
    +
    + if (yaffs_skip_nand_verification(dev))
    + return;
    +
    + for (i = 1; i <= last_chunk; i++) {
    + tn = yaffs_find_tnode_0(dev, &obj->variant.file_variant, i);
    +
    + if (tn) {
    + u32 the_chunk = yaffs_get_group_base(dev, tn, i);
    + if (the_chunk > 0) {
    + /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),obj_id,i,the_chunk)); */
    + yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
    + &tags);
    + if (tags.obj_id != obj_id || tags.chunk_id != i) {
    + T(~0,
    + (TSTR
    + ("Object %d chunk_id %d NAND mismatch chunk %d tags (%d:%d)"
    + TENDSTR), obj_id, i, the_chunk,
    + tags.obj_id, tags.chunk_id));
    + }
    + }
    + }
    + }
    +}
    +
    +void yaffs_verify_link(struct yaffs_obj *obj)
    +{
    + if (obj && yaffs_skip_verification(obj->my_dev))
    + return;
    +
    + /* Verify sane equivalent object */
    +}
    +
    +void yaffs_verify_symlink(struct yaffs_obj *obj)
    +{
    + if (obj && yaffs_skip_verification(obj->my_dev))
    + return;
    +
    + /* Verify symlink string */
    +}
    +
    +void yaffs_verify_special(struct yaffs_obj *obj)
    +{
    + if (obj && yaffs_skip_verification(obj->my_dev))
    + return;
    +}
    +
    +void yaffs_verify_obj(struct yaffs_obj *obj)
    +{
    + struct yaffs_dev *dev;
    +
    + u32 chunk_min;
    + u32 chunk_max;
    +
    + u32 chunk_id_ok;
    + u32 chunk_in_range;
    + u32 chunk_wrongly_deleted;
    + u32 chunk_valid;
    +
    + if (!obj)
    + return;
    +
    + if (obj->being_created)
    + return;
    +
    + dev = obj->my_dev;
    +
    + if (yaffs_skip_verification(dev))
    + return;
    +
    + /* Check sane object header chunk */
    +
    + chunk_min = dev->internal_start_block * dev->param.chunks_per_block;
    + chunk_max =
    + (dev->internal_end_block + 1) * dev->param.chunks_per_block - 1;
    +
    + chunk_in_range = (((unsigned)(obj->hdr_chunk)) >= chunk_min &&
    + ((unsigned)(obj->hdr_chunk)) <= chunk_max);
    + chunk_id_ok = chunk_in_range || (obj->hdr_chunk == 0);
    + chunk_valid = chunk_in_range &&
    + yaffs_check_chunk_bit(dev,
    + obj->hdr_chunk / dev->param.chunks_per_block,
    + obj->hdr_chunk % dev->param.chunks_per_block);
    + chunk_wrongly_deleted = chunk_in_range && !chunk_valid;
    +
    + if (!obj->fake && (!chunk_id_ok || chunk_wrongly_deleted)) {
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d has chunk_id %d %s %s" TENDSTR),
    + obj->obj_id, obj->hdr_chunk,
    + chunk_id_ok ? "" : ",out of range",
    + chunk_wrongly_deleted ? ",marked as deleted" : ""));
    + }
    +
    + if (chunk_valid && !yaffs_skip_nand_verification(dev)) {
    + struct yaffs_ext_tags tags;
    + struct yaffs_obj_hdr *oh;
    + u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
    +
    + oh = (struct yaffs_obj_hdr *)buffer;
    +
    + yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, buffer, &tags);
    +
    + yaffs_verify_oh(obj, oh, &tags, 1);
    +
    + yaffs_release_temp_buffer(dev, buffer, __LINE__);
    + }
    +
    + /* Verify it has a parent */
    + if (obj && !obj->fake && (!obj->parent || obj->parent->my_dev != dev)) {
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR
    + ("Obj %d has parent pointer %p which does not look like an object"
    + TENDSTR), obj->obj_id, obj->parent));
    + }
    +
    + /* Verify parent is a directory */
    + if (obj->parent
    + && obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d's parent is not a directory (type %d)" TENDSTR),
    + obj->obj_id, obj->parent->variant_type));
    + }
    +
    + switch (obj->variant_type) {
    + case YAFFS_OBJECT_TYPE_FILE:
    + yaffs_verify_file(obj);
    + break;
    + case YAFFS_OBJECT_TYPE_SYMLINK:
    + yaffs_verify_symlink(obj);
    + break;
    + case YAFFS_OBJECT_TYPE_DIRECTORY:
    + yaffs_verify_dir(obj);
    + break;
    + case YAFFS_OBJECT_TYPE_HARDLINK:
    + yaffs_verify_link(obj);
    + break;
    + case YAFFS_OBJECT_TYPE_SPECIAL:
    + yaffs_verify_special(obj);
    + break;
    + case YAFFS_OBJECT_TYPE_UNKNOWN:
    + default:
    + T(YAFFS_TRACE_VERIFY,
    + (TSTR("Obj %d has illegaltype %d" TENDSTR),
    + obj->obj_id, obj->variant_type));
    + break;
    + }
    +}
    +
    +void yaffs_verify_objects(struct yaffs_dev *dev)
    +{
    + struct yaffs_obj *obj;
    + int i;
    + struct list_head *lh;
    +
    + if (yaffs_skip_verification(dev))
    + return;
    +
    + /* Iterate through the objects in each hash entry */
    +
    + for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
    + list_for_each(lh, &dev->obj_bucket[i].list) {
    + if (lh) {
    + obj =
    + list_entry(lh, struct yaffs_obj, hash_link);
    + yaffs_verify_obj(obj);
    + }
    + }
    + }
    +}
    +
    +void yaffs_verify_obj_in_dir(struct yaffs_obj *obj)
    +{
    + struct list_head *lh;
    + struct yaffs_obj *list_obj;
    +
    + int count = 0;
    +
    + if (!obj) {
    + T(YAFFS_TRACE_ALWAYS, (TSTR("No object to verify" TENDSTR)));
    + YBUG();
    + return;
    + }
    +
    + if (yaffs_skip_verification(obj->my_dev))
    + return;
    +
    + if (!obj->parent) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("Object does not have parent" TENDSTR)));
    + YBUG();
    + return;
    + }
    +
    + if (obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("Parent is not directory" TENDSTR)));
    + YBUG();
    + }
    +
    + /* Iterate through the objects in each hash entry */
    +
    + list_for_each(lh, &obj->parent->variant.dir_variant.children) {
    + if (lh) {
    + list_obj = list_entry(lh, struct yaffs_obj, siblings);
    + yaffs_verify_obj(list_obj);
    + if (obj == list_obj)
    + count++;
    + }
    + }
    +
    + if (count != 1) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("Object in directory %d times" TENDSTR), count));
    + YBUG();
    + }
    +}
    +
    +void yaffs_verify_dir(struct yaffs_obj *directory)
    +{
    + struct list_head *lh;
    + struct yaffs_obj *list_obj;
    +
    + if (!directory) {
    + YBUG();
    + return;
    + }
    +
    + if (yaffs_skip_full_verification(directory->my_dev))
    + return;
    +
    + if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("Directory has wrong type: %d" TENDSTR),
    + directory->variant_type));
    + YBUG();
    + }
    +
    + /* Iterate through the objects in each hash entry */
    +
    + list_for_each(lh, &directory->variant.dir_variant.children) {
    + if (lh) {
    + list_obj = list_entry(lh, struct yaffs_obj, siblings);
    + if (list_obj->parent != directory) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR
    + ("Object in directory list has wrong parent %p"
    + TENDSTR), list_obj->parent));
    + YBUG();
    + }
    + yaffs_verify_obj_in_dir(list_obj);
    + }
    + }
    +}
    +
    +static int yaffs_free_verification_failures;
    +
    +void yaffs_verify_free_chunks(struct yaffs_dev *dev)
    +{
    + int counted;
    + int difference;
    +
    + if (yaffs_skip_verification(dev))
    + return;
    +
    + counted = yaffs_count_free_chunks(dev);
    +
    + difference = dev->n_free_chunks - counted;
    +
    + if (difference) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("Freechunks verification failure %d %d %d" TENDSTR),
    + dev->n_free_chunks, counted, difference));
    + yaffs_free_verification_failures++;
    + }
    +}
    +
    +int yaffs_verify_file_sane(struct yaffs_obj *in)
    +{
    + in = in;
    + return YAFFS_OK;
    +}
    diff --git a/fs/yaffs2/yaffs_verify.h b/fs/yaffs2/yaffs_verify.h
    new file mode 100644
    index 0000000..cc6f889
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_verify.h
    @@ -0,0 +1,43 @@
    +/*
    + * 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 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_VERIFY_H__
    +#define __YAFFS_VERIFY_H__
    +
    +#include "yaffs_guts.h"
    +
    +void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi,
    + int n);
    +void yaffs_verify_collected_blk(struct yaffs_dev *dev,
    + struct yaffs_block_info *bi, int n);
    +void yaffs_verify_blocks(struct yaffs_dev *dev);
    +
    +void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
    + struct yaffs_ext_tags *tags, int parent_check);
    +void yaffs_verify_file(struct yaffs_obj *obj);
    +void yaffs_verify_link(struct yaffs_obj *obj);
    +void yaffs_verify_symlink(struct yaffs_obj *obj);
    +void yaffs_verify_special(struct yaffs_obj *obj);
    +void yaffs_verify_obj(struct yaffs_obj *obj);
    +void yaffs_verify_objects(struct yaffs_dev *dev);
    +void yaffs_verify_obj_in_dir(struct yaffs_obj *obj);
    +void yaffs_verify_dir(struct yaffs_obj *directory);
    +void yaffs_verify_free_chunks(struct yaffs_dev *dev);
    +
    +int yaffs_verify_file_sane(struct yaffs_obj *obj);
    +
    +int yaffs_skip_verification(struct yaffs_dev *dev);
    +
    +#endif
    diff --git a/fs/yaffs2/yaffs_yaffs1.c b/fs/yaffs2/yaffs_yaffs1.c
    new file mode 100644
    index 0000000..4ab0f22
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_yaffs1.c
    @@ -0,0 +1,438 @@
    +/*
    + * 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_yaffs1.h"
    +#include "yportenv.h"
    +#include "yaffs_trace.h"
    +#include "yaffs_bitmap.h"
    +#include "yaffs_getblockinfo.h"
    +#include "yaffs_nand.h"
    +#include "yaffs_attribs.h"
    +
    +int yaffs1_scan(struct yaffs_dev *dev)
    +{
    + struct yaffs_ext_tags tags;
    + int blk;
    + int result;
    +
    + int chunk;
    + int c;
    + int deleted;
    + enum yaffs_block_state state;
    + struct yaffs_obj *hard_list = NULL;
    + struct yaffs_block_info *bi;
    + u32 seq_number;
    + struct yaffs_obj_hdr *oh;
    + struct yaffs_obj *in;
    + struct yaffs_obj *parent;
    +
    + int alloc_failed = 0;
    +
    + struct yaffs_shadow_fixer *shadow_fixers = NULL;
    +
    + u8 *chunk_data;
    +
    + T(YAFFS_TRACE_SCAN,
    + (TSTR("yaffs1_scan starts intstartblk %d intendblk %d..." TENDSTR),
    + dev->internal_start_block, dev->internal_end_block));
    +
    + chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
    +
    + dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
    +
    + /* Scan all the blocks to determine their state */
    + bi = dev->block_info;
    + for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
    + blk++) {
    + yaffs_clear_chunk_bits(dev, blk);
    + bi->pages_in_use = 0;
    + bi->soft_del_pages = 0;
    +
    + yaffs_query_init_block_state(dev, blk, &state, &seq_number);
    +
    + bi->block_state = state;
    + bi->seq_number = seq_number;
    +
    + if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
    + bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
    +
    + T(YAFFS_TRACE_SCAN_DEBUG,
    + (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
    + state, seq_number));
    +
    + if (state == YAFFS_BLOCK_STATE_DEAD) {
    + T(YAFFS_TRACE_BAD_BLOCKS,
    + (TSTR("block %d is bad" TENDSTR), blk));
    + } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
    + T(YAFFS_TRACE_SCAN_DEBUG,
    + (TSTR("Block empty " TENDSTR)));
    + dev->n_erased_blocks++;
    + dev->n_free_chunks += dev->param.chunks_per_block;
    + }
    + bi++;
    + }
    +
    + /* For each block.... */
    + for (blk = dev->internal_start_block;
    + !alloc_failed && blk <= dev->internal_end_block; blk++) {
    +
    + YYIELD();
    +
    + bi = yaffs_get_block_info(dev, blk);
    + state = bi->block_state;
    +
    + deleted = 0;
    +
    + /* For each chunk in each block that needs scanning.... */
    + for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
    + state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
    + /* Read the tags and decide what to do */
    + chunk = blk * dev->param.chunks_per_block + c;
    +
    + result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
    + &tags);
    +
    + /* Let's have a good look at this chunk... */
    +
    + if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED
    + || tags.is_deleted) {
    + /* YAFFS1 only...
    + * A deleted chunk
    + */
    + deleted++;
    + dev->n_free_chunks++;
    + /*T((" %d %d deleted\n",blk,c)); */
    + } else if (!tags.chunk_used) {
    + /* An unassigned chunk in the block
    + * This means that either the block is empty or
    + * this is the one being allocated from
    + */
    +
    + if (c == 0) {
    + /* We're looking at the first chunk in the block so the block is unused */
    + state = YAFFS_BLOCK_STATE_EMPTY;
    + dev->n_erased_blocks++;
    + } else {
    + /* this is the block being allocated from */
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + (" Allocating from %d %d" TENDSTR),
    + blk, c));
    + state = YAFFS_BLOCK_STATE_ALLOCATING;
    + dev->alloc_block = blk;
    + dev->alloc_page = c;
    + dev->alloc_block_finder = blk;
    + /* Set block finder here to encourage the allocator to go forth from here. */
    +
    + }
    +
    + dev->n_free_chunks +=
    + (dev->param.chunks_per_block - c);
    + } else if (tags.chunk_id > 0) {
    + /* chunk_id > 0 so it is a data chunk... */
    + unsigned int endpos;
    +
    + yaffs_set_chunk_bit(dev, blk, c);
    + bi->pages_in_use++;
    +
    + in = yaffs_find_or_create_by_number(dev,
    + tags.obj_id,
    + YAFFS_OBJECT_TYPE_FILE);
    + /* PutChunkIntoFile checks for a clash (two data chunks with
    + * the same chunk_id).
    + */
    +
    + if (!in)
    + alloc_failed = 1;
    +
    + if (in) {
    + if (!yaffs_put_chunk_in_file
    + (in, tags.chunk_id, chunk, 1))
    + alloc_failed = 1;
    + }
    +
    + endpos =
    + (tags.chunk_id -
    + 1) * dev->data_bytes_per_chunk +
    + tags.n_bytes;
    + if (in
    + && in->variant_type ==
    + YAFFS_OBJECT_TYPE_FILE
    + && in->variant.file_variant.scanned_size <
    + endpos) {
    + in->variant.file_variant.scanned_size =
    + endpos;
    + if (!dev->param.use_header_file_size) {
    + in->variant.
    + file_variant.file_size =
    + in->variant.
    + file_variant.scanned_size;
    + }
    +
    + }
    + /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id)); */
    + } else {
    + /* chunk_id == 0, so it is an ObjectHeader.
    + * Thus, we read in the object header and make the object
    + */
    + yaffs_set_chunk_bit(dev, blk, c);
    + bi->pages_in_use++;
    +
    + result = yaffs_rd_chunk_tags_nand(dev, chunk,
    + chunk_data,
    + NULL);
    +
    + oh = (struct yaffs_obj_hdr *)chunk_data;
    +
    + in = yaffs_find_by_number(dev, tags.obj_id);
    + if (in && in->variant_type != oh->type) {
    + /* This should not happen, but somehow
    + * Wev'e ended up with an obj_id that has been reused but not yet
    + * deleted, and worse still it has changed type. Delete the old object.
    + */
    +
    + yaffs_del_obj(in);
    +
    + in = 0;
    + }
    +
    + in = yaffs_find_or_create_by_number(dev,
    + tags.obj_id,
    + oh->type);
    +
    + if (!in)
    + alloc_failed = 1;
    +
    + if (in && oh->shadows_obj > 0) {
    +
    + struct yaffs_shadow_fixer *fixer;
    + fixer =
    + YMALLOC(sizeof
    + (struct
    + yaffs_shadow_fixer));
    + if (fixer) {
    + fixer->next = shadow_fixers;
    + shadow_fixers = fixer;
    + fixer->obj_id = tags.obj_id;
    + fixer->shadowed_id =
    + oh->shadows_obj;
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + (" Shadow fixer: %d shadows %d"
    + TENDSTR), fixer->obj_id,
    + fixer->shadowed_id));
    +
    + }
    +
    + }
    +
    + if (in && in->valid) {
    + /* We have already filled this one. We have a duplicate and need to resolve it. */
    +
    + unsigned existing_serial = in->serial;
    + unsigned new_serial =
    + tags.serial_number;
    +
    + if (((existing_serial + 1) & 3) ==
    + new_serial) {
    + /* Use new one - destroy the exisiting one */
    + yaffs_chunk_del(dev,
    + in->hdr_chunk,
    + 1, __LINE__);
    + in->valid = 0;
    + } else {
    + /* Use existing - destroy this one. */
    + yaffs_chunk_del(dev, chunk, 1,
    + __LINE__);
    + }
    + }
    +
    + if (in && !in->valid &&
    + (tags.obj_id == YAFFS_OBJECTID_ROOT ||
    + tags.obj_id ==
    + YAFFS_OBJECTID_LOSTNFOUND)) {
    + /* We only load some info, don't fiddle with directory structure */
    + in->valid = 1;
    + in->variant_type = oh->type;
    +
    + in->yst_mode = oh->yst_mode;
    + yaffs_load_attribs(in, oh);
    + in->hdr_chunk = chunk;
    + in->serial = tags.serial_number;
    +
    + } else if (in && !in->valid) {
    + /* we need to load this info */
    +
    + in->valid = 1;
    + in->variant_type = oh->type;
    +
    + in->yst_mode = oh->yst_mode;
    + yaffs_load_attribs(in, oh);
    + in->hdr_chunk = chunk;
    + in->serial = tags.serial_number;
    +
    + yaffs_set_obj_name_from_oh(in, oh);
    + in->dirty = 0;
    +
    + /* directory stuff...
    + * hook up to parent
    + */
    +
    + parent =
    + yaffs_find_or_create_by_number
    + (dev, oh->parent_obj_id,
    + YAFFS_OBJECT_TYPE_DIRECTORY);
    + if (!parent)
    + alloc_failed = 1;
    + if (parent && parent->variant_type ==
    + YAFFS_OBJECT_TYPE_UNKNOWN) {
    + /* Set up as a directory */
    + parent->variant_type =
    + YAFFS_OBJECT_TYPE_DIRECTORY;
    + INIT_LIST_HEAD(&parent->
    + variant.dir_variant.children);
    + } else if (!parent
    + || parent->variant_type !=
    + YAFFS_OBJECT_TYPE_DIRECTORY)
    + {
    + /* Hoosterman, another problem....
    + * We're trying to use a non-directory as a directory
    + */
    +
    + T(YAFFS_TRACE_ERROR,
    + (TSTR
    + ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
    + TENDSTR)));
    + parent = dev->lost_n_found;
    + }
    +
    + yaffs_add_obj_to_dir(parent, in);
    +
    + if (0 && (parent == dev->del_dir ||
    + parent ==
    + dev->unlinked_dir)) {
    + in->deleted = 1; /* If it is unlinked at start up then it wants deleting */
    + dev->n_deleted_files++;
    + }
    + /* Note re hardlinks.
    + * Since we might scan a hardlink before its equivalent object is scanned
    + * we put them all in a list.
    + * After scanning is complete, we should have all the objects, so we run through this
    + * list and fix up all the chains.
    + */
    +
    + switch (in->variant_type) {
    + case YAFFS_OBJECT_TYPE_UNKNOWN:
    + /* Todo got a problem */
    + break;
    + case YAFFS_OBJECT_TYPE_FILE:
    + if (dev->param.
    + use_header_file_size)
    +
    + in->variant.
    + file_variant.file_size
    + = oh->file_size;
    +
    + break;
    + case YAFFS_OBJECT_TYPE_HARDLINK:
    + in->variant.
    + hardlink_variant.equiv_id =
    + oh->equiv_id;
    + in->hard_links.next =
    + (struct list_head *)
    + hard_list;
    + hard_list = in;
    + break;
    + case YAFFS_OBJECT_TYPE_DIRECTORY:
    + /* Do nothing */
    + break;
    + case YAFFS_OBJECT_TYPE_SPECIAL:
    + /* Do nothing */
    + break;
    + case YAFFS_OBJECT_TYPE_SYMLINK:
    + in->variant.symlink_variant.
    + alias =
    + yaffs_clone_str(oh->alias);
    + if (!in->variant.
    + symlink_variant.alias)
    + alloc_failed = 1;
    + break;
    + }
    +
    + }
    + }
    + }
    +
    + if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
    + /* If we got this far while scanning, then the block is fully allocated. */
    + state = YAFFS_BLOCK_STATE_FULL;
    + }
    +
    + if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
    + /* If the block was partially allocated then treat it as fully allocated. */
    + state = YAFFS_BLOCK_STATE_FULL;
    + dev->alloc_block = -1;
    + }
    +
    + bi->block_state = state;
    +
    + /* Now let's see if it was dirty */
    + if (bi->pages_in_use == 0 &&
    + !bi->has_shrink_hdr &&
    + bi->block_state == YAFFS_BLOCK_STATE_FULL) {
    + yaffs_block_became_dirty(dev, blk);
    + }
    +
    + }
    +
    + /* Ok, we've done all the scanning.
    + * Fix up the hard link chains.
    + * We should now have scanned all the objects, now it's time to add these
    + * hardlinks.
    + */
    +
    + yaffs_link_fixup(dev, hard_list);
    +
    + /* Fix up any shadowed objects */
    + {
    + struct yaffs_shadow_fixer *fixer;
    + struct yaffs_obj *obj;
    +
    + while (shadow_fixers) {
    + fixer = shadow_fixers;
    + shadow_fixers = fixer->next;
    + /* Complete the rename transaction by deleting the shadowed object
    + * then setting the object header to unshadowed.
    + */
    + obj = yaffs_find_by_number(dev, fixer->shadowed_id);
    + if (obj)
    + yaffs_del_obj(obj);
    +
    + obj = yaffs_find_by_number(dev, fixer->obj_id);
    +
    + if (obj)
    + yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
    +
    + YFREE(fixer);
    + }
    + }
    +
    + yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
    +
    + if (alloc_failed)
    + return YAFFS_FAIL;
    +
    + T(YAFFS_TRACE_SCAN, (TSTR("yaffs1_scan ends" TENDSTR)));
    +
    + return YAFFS_OK;
    +}
    diff --git a/fs/yaffs2/yaffs_yaffs1.h b/fs/yaffs2/yaffs_yaffs1.h
    new file mode 100644
    index 0000000..db23e04
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_yaffs1.h
    @@ -0,0 +1,22 @@
    +/*
    + * 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 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_YAFFS1_H__
    +#define __YAFFS_YAFFS1_H__
    +
    +#include "yaffs_guts.h"
    +int yaffs1_scan(struct yaffs_dev *dev);
    +
    +#endif
    diff --git a/fs/yaffs2/yaffs_yaffs2.c b/fs/yaffs2/yaffs_yaffs2.c
    new file mode 100644
    index 0000000..97dac45
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_yaffs2.c
    @@ -0,0 +1,1618 @@
    +/*
    + * 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_guts.h"
    +#include "yaffs_trace.h"
    +#include "yaffs_yaffs2.h"
    +#include "yaffs_checkptrw.h"
    +#include "yaffs_bitmap.h"
    +#include "yaffs_nand.h"
    +#include "yaffs_getblockinfo.h"
    +#include "yaffs_verify.h"
    +#include "yaffs_attribs.h"
    +
    +/*
    + * Checkpoints are really no benefit on very small partitions.
    + *
    + * To save space on small partitions don't bother with checkpoints unless
    + * the partition is at least this big.
    + */
    +#define YAFFS_CHECKPOINT_MIN_BLOCKS 60
    +
    +#define YAFFS_SMALL_HOLE_THRESHOLD 4
    +
    +/*
    + * Oldest Dirty Sequence Number handling.
    + */
    +
    +/* yaffs_calc_oldest_dirty_seq()
    + * yaffs2_find_oldest_dirty_seq()
    + * Calculate the oldest dirty sequence number if we don't know it.
    + */
    +void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
    +{
    + int i;
    + unsigned seq;
    + unsigned block_no = 0;
    + struct yaffs_block_info *b;
    +
    + if (!dev->param.is_yaffs2)
    + return;
    +
    + /* Find the oldest dirty sequence number. */
    + seq = dev->seq_number + 1;
    + b = dev->block_info;
    + for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
    + if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
    + (b->pages_in_use - b->soft_del_pages) <
    + dev->param.chunks_per_block && b->seq_number < seq) {
    + seq = b->seq_number;
    + block_no = i;
    + }
    + b++;
    + }
    +
    + if (block_no) {
    + dev->oldest_dirty_seq = seq;
    + dev->oldest_dirty_block = block_no;
    + }
    +
    +}
    +
    +void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
    +{
    + if (!dev->param.is_yaffs2)
    + return;
    +
    + if (!dev->oldest_dirty_seq)
    + yaffs_calc_oldest_dirty_seq(dev);
    +}
    +
    +/*
    + * yaffs_clear_oldest_dirty_seq()
    + * Called when a block is erased or marked bad. (ie. when its seq_number
    + * becomes invalid). If the value matches the oldest then we clear
    + * dev->oldest_dirty_seq to force its recomputation.
    + */
    +void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
    + struct yaffs_block_info *bi)
    +{
    +
    + if (!dev->param.is_yaffs2)
    + return;
    +
    + if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
    + dev->oldest_dirty_seq = 0;
    + dev->oldest_dirty_block = 0;
    + }
    +}
    +
    +/*
    + * yaffs2_update_oldest_dirty_seq()
    + * Update the oldest dirty sequence number whenever we dirty a block.
    + * Only do this if the oldest_dirty_seq is actually being tracked.
    + */
    +void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
    + struct yaffs_block_info *bi)
    +{
    + if (!dev->param.is_yaffs2)
    + return;
    +
    + if (dev->oldest_dirty_seq) {
    + if (dev->oldest_dirty_seq > bi->seq_number) {
    + dev->oldest_dirty_seq = bi->seq_number;
    + dev->oldest_dirty_block = block_no;
    + }
    + }
    +}
    +
    +int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
    +{
    +
    + if (!dev->param.is_yaffs2)
    + return 1; /* disqualification only applies to yaffs2. */
    +
    + if (!bi->has_shrink_hdr)
    + return 1; /* can gc */
    +
    + yaffs2_find_oldest_dirty_seq(dev);
    +
    + /* Can't do gc of this block if there are any blocks older than this one that have
    + * discarded pages.
    + */
    + return (bi->seq_number <= dev->oldest_dirty_seq);
    +}
    +
    +/*
    + * yaffs2_find_refresh_block()
    + * periodically finds the oldest full block by sequence number for refreshing.
    + * Only for yaffs2.
    + */
    +u32 yaffs2_find_refresh_block(struct yaffs_dev * dev)
    +{
    + u32 b;
    +
    + u32 oldest = 0;
    + u32 oldest_seq = 0;
    +
    + struct yaffs_block_info *bi;
    +
    + if (!dev->param.is_yaffs2)
    + return oldest;
    +
    + /*
    + * If refresh period < 10 then refreshing is disabled.
    + */
    + if (dev->param.refresh_period < 10)
    + return oldest;
    +
    + /*
    + * Fix broken values.
    + */
    + if (dev->refresh_skip > dev->param.refresh_period)
    + dev->refresh_skip = dev->param.refresh_period;
    +
    + if (dev->refresh_skip > 0)
    + return oldest;
    +
    + /*
    + * Refresh skip is now zero.
    + * We'll do a refresh this time around....
    + * Update the refresh skip and find the oldest block.
    + */
    + dev->refresh_skip = dev->param.refresh_period;
    + dev->refresh_count++;
    + bi = dev->block_info;
    + for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
    +
    + if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
    +
    + if (oldest < 1 || bi->seq_number < oldest_seq) {
    + oldest = b;
    + oldest_seq = bi->seq_number;
    + }
    + }
    + bi++;
    + }
    +
    + if (oldest > 0) {
    + T(YAFFS_TRACE_GC,
    + (TSTR
    + ("GC refresh count %d selected block %d with seq_number %d"
    + TENDSTR), dev->refresh_count, oldest, oldest_seq));
    + }
    +
    + return oldest;
    +}
    +
    +int yaffs2_checkpt_required(struct yaffs_dev *dev)
    +{
    + int nblocks;
    +
    + if (!dev->param.is_yaffs2)
    + return 0;
    +
    + nblocks = dev->internal_end_block - dev->internal_start_block + 1;
    +
    + return !dev->param.skip_checkpt_wr &&
    + !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
    +}
    +
    +int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
    +{
    + int retval;
    +
    + if (!dev->param.is_yaffs2)
    + return 0;
    +
    + if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
    + /* Not a valid value so recalculate */
    + int n_bytes = 0;
    + int n_blocks;
    + int dev_blocks =
    + (dev->param.end_block - dev->param.start_block + 1);
    +
    + n_bytes += sizeof(struct yaffs_checkpt_validity);
    + n_bytes += sizeof(struct yaffs_checkpt_dev);
    + n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
    + n_bytes += dev_blocks * dev->chunk_bit_stride;
    + n_bytes +=
    + (sizeof(struct yaffs_checkpt_obj) +
    + sizeof(u32)) * (dev->n_obj);
    + n_bytes += (dev->tnode_size + sizeof(u32)) * (dev->n_tnodes);
    + n_bytes += sizeof(struct yaffs_checkpt_validity);
    + n_bytes += sizeof(u32); /* checksum */
    +
    + /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
    +
    + n_blocks =
    + (n_bytes /
    + (dev->data_bytes_per_chunk *
    + dev->param.chunks_per_block)) + 3;
    +
    + dev->checkpoint_blocks_required = n_blocks;
    + }
    +
    + retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
    + if (retval < 0)
    + retval = 0;
    + return retval;
    +}
    +
    +/*--------------------- Checkpointing --------------------*/
    +
    +static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
    +{
    + struct yaffs_checkpt_validity cp;
    +
    + memset(&cp, 0, sizeof(cp));
    +
    + cp.struct_type = sizeof(cp);
    + cp.magic = YAFFS_MAGIC;
    + cp.version = YAFFS_CHECKPOINT_VERSION;
    + cp.head = (head) ? 1 : 0;
    +
    + return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
    +}
    +
    +static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
    +{
    + struct yaffs_checkpt_validity cp;
    + int ok;
    +
    + ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
    +
    + if (ok)
    + ok = (cp.struct_type == sizeof(cp)) &&
    + (cp.magic == YAFFS_MAGIC) &&
    + (cp.version == YAFFS_CHECKPOINT_VERSION) &&
    + (cp.head == ((head) ? 1 : 0));
    + return ok ? 1 : 0;
    +}
    +
    +static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
    + struct yaffs_dev *dev)
    +{
    + cp->n_erased_blocks = dev->n_erased_blocks;
    + cp->alloc_block = dev->alloc_block;
    + cp->alloc_page = dev->alloc_page;
    + cp->n_free_chunks = dev->n_free_chunks;
    +
    + cp->n_deleted_files = dev->n_deleted_files;
    + cp->n_unlinked_files = dev->n_unlinked_files;
    + cp->n_bg_deletions = dev->n_bg_deletions;
    + cp->seq_number = dev->seq_number;
    +
    +}
    +
    +static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
    + struct yaffs_checkpt_dev *cp)
    +{
    + dev->n_erased_blocks = cp->n_erased_blocks;
    + dev->alloc_block = cp->alloc_block;
    + dev->alloc_page = cp->alloc_page;
    + dev->n_free_chunks = cp->n_free_chunks;
    +
    + dev->n_deleted_files = cp->n_deleted_files;
    + dev->n_unlinked_files = cp->n_unlinked_files;
    + dev->n_bg_deletions = cp->n_bg_deletions;
    + dev->seq_number = cp->seq_number;
    +}
    +
    +static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
    +{
    + struct yaffs_checkpt_dev cp;
    + u32 n_bytes;
    + u32 n_blocks =
    + (dev->internal_end_block - dev->internal_start_block + 1);
    +
    + int ok;
    +
    + /* Write device runtime values */
    + yaffs2_dev_to_checkpt_dev(&cp, dev);
    + cp.struct_type = sizeof(cp);
    +
    + ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
    +
    + /* Write block info */
    + if (ok) {
    + n_bytes = n_blocks * sizeof(struct yaffs_block_info);
    + ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) ==
    + n_bytes);
    + }
    +
    + /* Write chunk bits */
    + if (ok) {
    + n_bytes = n_blocks * dev->chunk_bit_stride;
    + ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) ==
    + n_bytes);
    + }
    + return ok ? 1 : 0;
    +
    +}
    +
    +static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
    +{
    + struct yaffs_checkpt_dev cp;
    + u32 n_bytes;
    + u32 n_blocks =
    + (dev->internal_end_block - dev->internal_start_block + 1);
    +
    + int ok;
    +
    + ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
    + if (!ok)
    + return 0;
    +
    + if (cp.struct_type != sizeof(cp))
    + return 0;
    +
    + yaffs_checkpt_dev_to_dev(dev, &cp);
    +
    + n_bytes = n_blocks * sizeof(struct yaffs_block_info);
    +
    + ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);
    +
    + if (!ok)
    + return 0;
    + n_bytes = n_blocks * dev->chunk_bit_stride;
    +
    + ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);
    +
    + return ok ? 1 : 0;
    +}
    +
    +static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
    + struct yaffs_obj *obj)
    +{
    +
    + cp->obj_id = obj->obj_id;
    + cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
    + cp->hdr_chunk = obj->hdr_chunk;
    + cp->variant_type = obj->variant_type;
    + cp->deleted = obj->deleted;
    + cp->soft_del = obj->soft_del;
    + cp->unlinked = obj->unlinked;
    + cp->fake = obj->fake;
    + cp->rename_allowed = obj->rename_allowed;
    + cp->unlink_allowed = obj->unlink_allowed;
    + cp->serial = obj->serial;
    + cp->n_data_chunks = obj->n_data_chunks;
    +
    + if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
    + cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
    + else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
    + cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
    +}
    +
    +static int taffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
    + struct yaffs_checkpt_obj *cp)
    +{
    +
    + struct yaffs_obj *parent;
    +
    + if (obj->variant_type != cp->variant_type) {
    + T(YAFFS_TRACE_ERROR, (TSTR("Checkpoint read object %d type %d "
    + TCONT
    + ("chunk %d does not match existing object type %d")
    + TENDSTR), cp->obj_id,
    + cp->variant_type, cp->hdr_chunk,
    + obj->variant_type));
    + return 0;
    + }
    +
    + obj->obj_id = cp->obj_id;
    +
    + if (cp->parent_id)
    + parent = yaffs_find_or_create_by_number(obj->my_dev,
    + cp->parent_id,
    + YAFFS_OBJECT_TYPE_DIRECTORY);
    + else
    + parent = NULL;
    +
    + if (parent) {
    + if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR
    + ("Checkpoint read object %d parent %d type %d"
    + TCONT(" chunk %d Parent type, %d, not directory")
    + TENDSTR), cp->obj_id, cp->parent_id,
    + cp->variant_type, cp->hdr_chunk,
    + parent->variant_type));
    + return 0;
    + }
    + yaffs_add_obj_to_dir(parent, obj);
    + }
    +
    + obj->hdr_chunk = cp->hdr_chunk;
    + obj->variant_type = cp->variant_type;
    + obj->deleted = cp->deleted;
    + obj->soft_del = cp->soft_del;
    + obj->unlinked = cp->unlinked;
    + obj->fake = cp->fake;
    + obj->rename_allowed = cp->rename_allowed;
    + obj->unlink_allowed = cp->unlink_allowed;
    + obj->serial = cp->serial;
    + obj->n_data_chunks = cp->n_data_chunks;
    +
    + if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
    + obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
    + else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
    + obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
    +
    + if (obj->hdr_chunk > 0)
    + obj->lazy_loaded = 1;
    + return 1;
    +}
    +
    +static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
    + struct yaffs_tnode *tn, u32 level,
    + int chunk_offset)
    +{
    + int i;
    + struct yaffs_dev *dev = in->my_dev;
    + int ok = 1;
    +
    + if (tn) {
    + if (level > 0) {
    +
    + for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
    + if (tn->internal[i]) {
    + ok = yaffs2_checkpt_tnode_worker(in,
    + tn->
    + internal
    + [i],
    + level -
    + 1,
    + (chunk_offset
    + <<
    + YAFFS_TNODES_INTERNAL_BITS)
    + + i);
    + }
    + }
    + } else if (level == 0) {
    + u32 base_offset =
    + chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
    + ok = (yaffs2_checkpt_wr
    + (dev, &base_offset,
    + sizeof(base_offset)) == sizeof(base_offset));
    + if (ok)
    + ok = (yaffs2_checkpt_wr
    + (dev, tn,
    + dev->tnode_size) == dev->tnode_size);
    + }
    + }
    +
    + return ok;
    +
    +}
    +
    +static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
    +{
    + u32 end_marker = ~0;
    + int ok = 1;
    +
    + if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
    + ok = yaffs2_checkpt_tnode_worker(obj,
    + obj->variant.file_variant.top,
    + obj->variant.file_variant.
    + top_level, 0);
    + if (ok)
    + ok = (yaffs2_checkpt_wr
    + (obj->my_dev, &end_marker,
    + sizeof(end_marker)) == sizeof(end_marker));
    + }
    +
    + return ok ? 1 : 0;
    +}
    +
    +static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
    +{
    + u32 base_chunk;
    + int ok = 1;
    + struct yaffs_dev *dev = obj->my_dev;
    + struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
    + struct yaffs_tnode *tn;
    + int nread = 0;
    +
    + ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
    + sizeof(base_chunk));
    +
    + while (ok && (~base_chunk)) {
    + nread++;
    + /* Read level 0 tnode */
    +
    + tn = yaffs_get_tnode(dev);
    + if (tn) {
    + ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
    + dev->tnode_size);
    + } else
    + ok = 0;
    +
    + if (tn && ok)
    + ok = yaffs_add_find_tnode_0(dev,
    + file_stuct_ptr,
    + base_chunk, tn) ? 1 : 0;
    +
    + if (ok)
    + ok = (yaffs2_checkpt_rd
    + (dev, &base_chunk,
    + sizeof(base_chunk)) == sizeof(base_chunk));
    +
    + }
    +
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
    + nread, base_chunk, ok));
    +
    + return ok ? 1 : 0;
    +}
    +
    +static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
    +{
    + struct yaffs_obj *obj;
    + struct yaffs_checkpt_obj cp;
    + int i;
    + int ok = 1;
    + struct list_head *lh;
    +
    + /* Iterate through the objects in each hash entry,
    + * dumping them to the checkpointing stream.
    + */
    +
    + for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
    + list_for_each(lh, &dev->obj_bucket[i].list) {
    + if (lh) {
    + obj =
    + list_entry(lh, struct yaffs_obj, hash_link);
    + if (!obj->defered_free) {
    + yaffs2_obj_checkpt_obj(&cp, obj);
    + cp.struct_type = sizeof(cp);
    +
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR
    + ("Checkpoint write object %d parent %d type %d chunk %d obj addr %p"
    + TENDSTR), cp.obj_id, cp.parent_id,
    + cp.variant_type, cp.hdr_chunk, obj));
    +
    + ok = (yaffs2_checkpt_wr
    + (dev, &cp,
    + sizeof(cp)) == sizeof(cp));
    +
    + if (ok
    + && obj->variant_type ==
    + YAFFS_OBJECT_TYPE_FILE)
    + ok = yaffs2_wr_checkpt_tnodes
    + (obj);
    + }
    + }
    + }
    + }
    +
    + /* Dump end of list */
    + memset(&cp, 0xFF, sizeof(struct yaffs_checkpt_obj));
    + cp.struct_type = sizeof(cp);
    +
    + if (ok)
    + ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
    +
    + return ok ? 1 : 0;
    +}
    +
    +static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
    +{
    + struct yaffs_obj *obj;
    + struct yaffs_checkpt_obj cp;
    + int ok = 1;
    + int done = 0;
    + struct yaffs_obj *hard_list = NULL;
    +
    + while (ok && !done) {
    + ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
    + if (cp.struct_type != sizeof(cp)) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("struct size %d instead of %d ok %d" TENDSTR),
    + cp.struct_type, (int)sizeof(cp), ok));
    + ok = 0;
    + }
    +
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR
    + ("Checkpoint read object %d parent %d type %d chunk %d "
    + TENDSTR), cp.obj_id, cp.parent_id, cp.variant_type,
    + cp.hdr_chunk));
    +
    + if (ok && cp.obj_id == ~0)
    + done = 1;
    + else if (ok) {
    + obj =
    + yaffs_find_or_create_by_number(dev, cp.obj_id,
    + cp.variant_type);
    + if (obj) {
    + ok = taffs2_checkpt_obj_to_obj(obj, &cp);
    + if (!ok)
    + break;
    + if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
    + ok = yaffs2_rd_checkpt_tnodes(obj);
    + } else if (obj->variant_type ==
    + YAFFS_OBJECT_TYPE_HARDLINK) {
    + obj->hard_links.next =
    + (struct list_head *)hard_list;
    + hard_list = obj;
    + }
    + } else
    + ok = 0;
    + }
    + }
    +
    + if (ok)
    + yaffs_link_fixup(dev, hard_list);
    +
    + return ok ? 1 : 0;
    +}
    +
    +static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
    +{
    + u32 checkpt_sum;
    + int ok;
    +
    + yaffs2_get_checkpt_sum(dev, &checkpt_sum);
    +
    + ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
    + sizeof(checkpt_sum));
    +
    + if (!ok)
    + return 0;
    +
    + return 1;
    +}
    +
    +static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
    +{
    + u32 checkpt_sum0;
    + u32 checkpt_sum1;
    + int ok;
    +
    + yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
    +
    + ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
    + sizeof(checkpt_sum1));
    +
    + if (!ok)
    + return 0;
    +
    + if (checkpt_sum0 != checkpt_sum1)
    + return 0;
    +
    + return 1;
    +}
    +
    +static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
    +{
    + int ok = 1;
    +
    + if (!yaffs2_checkpt_required(dev)) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("skipping checkpoint write" TENDSTR)));
    + ok = 0;
    + }
    +
    + if (ok)
    + ok = yaffs2_checkpt_open(dev, 1);
    +
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("write checkpoint validity" TENDSTR)));
    + ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("write checkpoint device" TENDSTR)));
    + ok = yaffs2_wr_checkpt_dev(dev);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("write checkpoint objects" TENDSTR)));
    + ok = yaffs2_wr_checkpt_objs(dev);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("write checkpoint validity" TENDSTR)));
    + ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
    + }
    +
    + if (ok)
    + ok = yaffs2_wr_checkpt_sum(dev);
    +
    + if (!yaffs_checkpt_close(dev))
    + ok = 0;
    +
    + if (ok)
    + dev->is_checkpointed = 1;
    + else
    + dev->is_checkpointed = 0;
    +
    + return dev->is_checkpointed;
    +}
    +
    +static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
    +{
    + int ok = 1;
    +
    + if (!dev->param.is_yaffs2)
    + ok = 0;
    +
    + if (ok && dev->param.skip_checkpt_rd) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("skipping checkpoint read" TENDSTR)));
    + ok = 0;
    + }
    +
    + if (ok)
    + ok = yaffs2_checkpt_open(dev, 0); /* open for read */
    +
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("read checkpoint validity" TENDSTR)));
    + ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("read checkpoint device" TENDSTR)));
    + ok = yaffs2_rd_checkpt_dev(dev);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("read checkpoint objects" TENDSTR)));
    + ok = yaffs2_rd_checkpt_objs(dev);
    + }
    + if (ok) {
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("read checkpoint validity" TENDSTR)));
    + ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
    + }
    +
    + if (ok) {
    + ok = yaffs2_rd_checkpt_sum(dev);
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("read checkpoint checksum %d" TENDSTR), ok));
    + }
    +
    + if (!yaffs_checkpt_close(dev))
    + ok = 0;
    +
    + if (ok)
    + dev->is_checkpointed = 1;
    + else
    + dev->is_checkpointed = 0;
    +
    + return ok ? 1 : 0;
    +
    +}
    +
    +void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
    +{
    + if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
    + dev->is_checkpointed = 0;
    + yaffs2_checkpt_invalidate_stream(dev);
    + }
    + if (dev->param.sb_dirty_fn)
    + dev->param.sb_dirty_fn(dev);
    +}
    +
    +int yaffs_checkpoint_save(struct yaffs_dev *dev)
    +{
    +
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("save entry: is_checkpointed %d" TENDSTR),
    + dev->is_checkpointed));
    +
    + yaffs_verify_objects(dev);
    + yaffs_verify_blocks(dev);
    + yaffs_verify_free_chunks(dev);
    +
    + if (!dev->is_checkpointed) {
    + yaffs2_checkpt_invalidate(dev);
    + yaffs2_wr_checkpt_data(dev);
    + }
    +
    + T(YAFFS_TRACE_ALWAYS,
    + (TSTR("save exit: is_checkpointed %d" TENDSTR),
    + dev->is_checkpointed));
    +
    + return dev->is_checkpointed;
    +}
    +
    +int yaffs2_checkpt_restore(struct yaffs_dev *dev)
    +{
    + int retval;
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("restore entry: is_checkpointed %d" TENDSTR),
    + dev->is_checkpointed));
    +
    + retval = yaffs2_rd_checkpt_data(dev);
    +
    + if (dev->is_checkpointed) {
    + yaffs_verify_objects(dev);
    + yaffs_verify_blocks(dev);
    + yaffs_verify_free_chunks(dev);
    + }
    +
    + T(YAFFS_TRACE_CHECKPOINT,
    + (TSTR("restore exit: is_checkpointed %d" TENDSTR),
    + dev->is_checkpointed));
    +
    + return retval;
    +}
    +
    +int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
    +{
    + /* if new_size > old_file_size.
    + * We're going to be writing a hole.
    + * If the hole is small then write zeros otherwise write a start of hole marker.
    + */
    +
    + loff_t old_file_size;
    + int increase;
    + int small_hole;
    + int result = YAFFS_OK;
    + struct yaffs_dev *dev = NULL;
    +
    + u8 *local_buffer = NULL;
    +
    + int small_increase_ok = 0;
    +
    + if (!obj)
    + return YAFFS_FAIL;
    +
    + if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
    + return YAFFS_FAIL;
    +
    + dev = obj->my_dev;
    +
    + /* Bail out if not yaffs2 mode */
    + if (!dev->param.is_yaffs2)
    + return YAFFS_OK;
    +
    + old_file_size = obj->variant.file_variant.file_size;
    +
    + if (new_size <= old_file_size)
    + return YAFFS_OK;
    +
    + increase = new_size - old_file_size;
    +
    + if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
    + yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
    + small_hole = 1;
    + else
    + small_hole = 0;
    +
    + if (small_hole)
    + local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
    +
    + if (local_buffer) {
    + /* fill hole with zero bytes */
    + int pos = old_file_size;
    + int this_write;
    + int written;
    + memset(local_buffer, 0, dev->data_bytes_per_chunk);
    + small_increase_ok = 1;
    +
    + while (increase > 0 && small_increase_ok) {
    + this_write = increase;
    + if (this_write > dev->data_bytes_per_chunk)
    + this_write = dev->data_bytes_per_chunk;
    + written =
    + yaffs_do_file_wr(obj, local_buffer, pos, this_write,
    + 0);
    + if (written == this_write) {
    + pos += this_write;
    + increase -= this_write;
    + } else
    + small_increase_ok = 0;
    + }
    +
    + yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
    +
    + /* If we were out of space then reverse any chunks we've added */
    + if (!small_increase_ok)
    + yaffs_resize_file_down(obj, old_file_size);
    + }
    +
    + if (!small_increase_ok &&
    + obj->parent &&
    + obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
    + obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
    + /* Write a hole start header with the old file size */
    + yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
    + }
    +
    + return result;
    +
    +}
    +
    +struct yaffs_block_index {
    + int seq;
    + int block;
    +};
    +
    +static int yaffs2_ybicmp(const void *a, const void *b)
    +{
    + int aseq = ((struct yaffs_block_index *)a)->seq;
    + int bseq = ((struct yaffs_block_index *)b)->seq;
    + int ablock = ((struct yaffs_block_index *)a)->block;
    + int bblock = ((struct yaffs_block_index *)b)->block;
    + if (aseq == bseq)
    + return ablock - bblock;
    + else
    + return aseq - bseq;
    +}
    +
    +int yaffs2_scan_backwards(struct yaffs_dev *dev)
    +{
    + struct yaffs_ext_tags tags;
    + int blk;
    + int block_iter;
    + int start_iter;
    + int end_iter;
    + int n_to_scan = 0;
    +
    + int chunk;
    + int result;
    + int c;
    + int deleted;
    + enum yaffs_block_state state;
    + struct yaffs_obj *hard_list = NULL;
    + struct yaffs_block_info *bi;
    + u32 seq_number;
    + struct yaffs_obj_hdr *oh;
    + struct yaffs_obj *in;
    + struct yaffs_obj *parent;
    + int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
    + int is_unlinked;
    + u8 *chunk_data;
    +
    + int file_size;
    + int is_shrink;
    + int found_chunks;
    + int equiv_id;
    + int alloc_failed = 0;
    +
    + struct yaffs_block_index *block_index = NULL;
    + int alt_block_index = 0;
    +
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + ("yaffs2_scan_backwards starts intstartblk %d intendblk %d..."
    + TENDSTR), dev->internal_start_block, dev->internal_end_block));
    +
    + dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
    +
    + block_index = YMALLOC(n_blocks * sizeof(struct yaffs_block_index));
    +
    + if (!block_index) {
    + block_index =
    + YMALLOC_ALT(n_blocks * sizeof(struct yaffs_block_index));
    + alt_block_index = 1;
    + }
    +
    + if (!block_index) {
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + ("yaffs2_scan_backwards() could not allocate block index!"
    + TENDSTR)));
    + return YAFFS_FAIL;
    + }
    +
    + dev->blocks_in_checkpt = 0;
    +
    + chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
    +
    + /* Scan all the blocks to determine their state */
    + bi = dev->block_info;
    + for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
    + blk++) {
    + yaffs_clear_chunk_bits(dev, blk);
    + bi->pages_in_use = 0;
    + bi->soft_del_pages = 0;
    +
    + yaffs_query_init_block_state(dev, blk, &state, &seq_number);
    +
    + bi->block_state = state;
    + bi->seq_number = seq_number;
    +
    + if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
    + bi->block_state = state = YAFFS_BLOCK_STATE_CHECKPOINT;
    + if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
    + bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
    +
    + T(YAFFS_TRACE_SCAN_DEBUG,
    + (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
    + state, seq_number));
    +
    + if (state == YAFFS_BLOCK_STATE_CHECKPOINT) {
    + dev->blocks_in_checkpt++;
    +
    + } else if (state == YAFFS_BLOCK_STATE_DEAD) {
    + T(YAFFS_TRACE_BAD_BLOCKS,
    + (TSTR("block %d is bad" TENDSTR), blk));
    + } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
    + T(YAFFS_TRACE_SCAN_DEBUG,
    + (TSTR("Block empty " TENDSTR)));
    + dev->n_erased_blocks++;
    + dev->n_free_chunks += dev->param.chunks_per_block;
    + } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
    +
    + /* Determine the highest sequence number */
    + if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
    + seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
    +
    + block_index[n_to_scan].seq = seq_number;
    + block_index[n_to_scan].block = blk;
    +
    + n_to_scan++;
    +
    + if (seq_number >= dev->seq_number)
    + dev->seq_number = seq_number;
    + } else {
    + /* TODO: Nasty sequence number! */
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + ("Block scanning block %d has bad sequence number %d"
    + TENDSTR), blk, seq_number));
    +
    + }
    + }
    + bi++;
    + }
    +
    + T(YAFFS_TRACE_SCAN,
    + (TSTR("%d blocks to be sorted..." TENDSTR), n_to_scan));
    +
    + YYIELD();
    +
    + /* Sort the blocks by sequence number */
    + yaffs_sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
    + yaffs2_ybicmp);
    +
    + YYIELD();
    +
    + T(YAFFS_TRACE_SCAN, (TSTR("...done" TENDSTR)));
    +
    + /* Now scan the blocks looking at the data. */
    + start_iter = 0;
    + end_iter = n_to_scan - 1;
    + T(YAFFS_TRACE_SCAN_DEBUG,
    + (TSTR("%d blocks to be scanned" TENDSTR), n_to_scan));
    +
    + /* For each block.... backwards */
    + for (block_iter = end_iter; !alloc_failed && block_iter >= start_iter;
    + block_iter--) {
    + /* Cooperative multitasking! This loop can run for so
    + long that watchdog timers expire. */
    + YYIELD();
    +
    + /* get the block to scan in the correct order */
    + blk = block_index[block_iter].block;
    +
    + bi = yaffs_get_block_info(dev, blk);
    +
    + state = bi->block_state;
    +
    + deleted = 0;
    +
    + /* For each chunk in each block that needs scanning.... */
    + found_chunks = 0;
    + for (c = dev->param.chunks_per_block - 1;
    + !alloc_failed && c >= 0 &&
    + (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
    + state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
    + /* Scan backwards...
    + * Read the tags and decide what to do
    + */
    +
    + chunk = blk * dev->param.chunks_per_block + c;
    +
    + result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
    + &tags);
    +
    + /* Let's have a good look at this chunk... */
    +
    + if (!tags.chunk_used) {
    + /* An unassigned chunk in the block.
    + * If there are used chunks after this one, then
    + * it is a chunk that was skipped due to failing the erased
    + * check. Just skip it so that it can be deleted.
    + * But, more typically, We get here when this is an unallocated
    + * chunk and his means that either the block is empty or
    + * this is the one being allocated from
    + */
    +
    + if (found_chunks) {
    + /* This is a chunk that was skipped due to failing the erased check */
    + } else if (c == 0) {
    + /* We're looking at the first chunk in the block so the block is unused */
    + state = YAFFS_BLOCK_STATE_EMPTY;
    + dev->n_erased_blocks++;
    + } else {
    + if (state ==
    + YAFFS_BLOCK_STATE_NEEDS_SCANNING
    + || state ==
    + YAFFS_BLOCK_STATE_ALLOCATING) {
    + if (dev->seq_number ==
    + bi->seq_number) {
    + /* this is the block being allocated from */
    +
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + (" Allocating from %d %d"
    + TENDSTR), blk, c));
    +
    + state =
    + YAFFS_BLOCK_STATE_ALLOCATING;
    + dev->alloc_block = blk;
    + dev->alloc_page = c;
    + dev->
    + alloc_block_finder =
    + blk;
    + } else {
    + /* This is a partially written block that is not
    + * the current allocation block.
    + */
    +
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + ("Partially written block %d detected"
    + TENDSTR), blk));
    + }
    + }
    + }
    +
    + dev->n_free_chunks++;
    +
    + } else if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED) {
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + (" Unfixed ECC in chunk(%d:%d), chunk ignored"
    + TENDSTR), blk, c));
    +
    + dev->n_free_chunks++;
    +
    + } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
    + tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
    + (tags.chunk_id > 0
    + && tags.n_bytes > dev->data_bytes_per_chunk)
    + || tags.seq_number != bi->seq_number) {
    + T(YAFFS_TRACE_SCAN,
    + (TSTR
    + ("Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored"
    + TENDSTR), blk, c, tags.obj_id,
    + tags.chunk_id, tags.n_bytes));
    +
    + dev->n_free_chunks++;
    +
    + } else if (tags.chunk_id > 0) {
    + /* chunk_id > 0 so it is a data chunk... */
    + unsigned int endpos;
    + u32 chunk_base =
    + (tags.chunk_id -
    + 1) * dev->data_bytes_per_chunk;
    +
    + found_chunks = 1;
    +
    + yaffs_set_chunk_bit(dev, blk, c);
    + bi->pages_in_use++;
    +
    + in = yaffs_find_or_create_by_number(dev,
    + tags.obj_id,
    + YAFFS_OBJECT_TYPE_FILE);
    + if (!in) {
    + /* Out of memory */
    + alloc_failed = 1;
    + }
    +
    + if (in &&
    + in->variant_type == YAFFS_OBJECT_TYPE_FILE
    + && chunk_base <
    + in->variant.file_variant.shrink_size) {
    + /* This has not been invalidated by a resize */
    + if (!yaffs_put_chunk_in_file
    + (in, tags.chunk_id, chunk, -1)) {
    + alloc_failed = 1;
    + }
    +
    + /* File size is calculated by looking at the data chunks if we have not
    + * seen an object header yet. Stop this practice once we find an object header.
    + */
    + endpos = chunk_base + tags.n_bytes;
    +
    + if (!in->valid && /* have not got an object header yet */
    + in->variant.file_variant.
    + scanned_size < endpos) {
    + in->variant.file_variant.
    + scanned_size = endpos;
    + in->variant.file_variant.
    + file_size = endpos;
    + }
    +
    + } else if (in) {
    + /* This chunk has been invalidated by a resize, or a past file deletion
    + * so delete the chunk*/
    + yaffs_chunk_del(dev, chunk, 1,
    + __LINE__);
    +
    + }
    + } else {
    + /* chunk_id == 0, so it is an ObjectHeader.
    + * Thus, we read in the object header and make the object
    + */
    + found_chunks = 1;
    +
    + yaffs_set_chunk_bit(dev, blk, c);
    + bi->pages_in_use++;
    +
    + oh = NULL;
    + in = NULL;
    +
    + if (tags.extra_available) {
    + in = yaffs_find_or_create_by_number(dev,
    + tags.
    + obj_id,
    + tags.
    + extra_obj_type);
    + if (!in)
    + alloc_failed = 1;
    + }
    +
    + if (!in ||
    + (!in->valid && dev->param.disable_lazy_load)
    + || tags.extra_shadows || (!in->valid
    + && (tags.obj_id ==
    + YAFFS_OBJECTID_ROOT
    + || tags.
    + obj_id ==
    + YAFFS_OBJECTID_LOSTNFOUND)))
    + {
    +
    + /* If we don't have valid info then we need to read the chunk
    + * TODO In future we can probably defer reading the chunk and
    + * living with invalid data until needed.
    + */
    +
    + result = yaffs_rd_chunk_tags_nand(dev,
    + chunk,
    + chunk_data,
    + NULL);
    +
    + oh = (struct yaffs_obj_hdr *)chunk_data;
    +
    + if (dev->param.inband_tags) {
    + /* Fix up the header if they got corrupted by inband tags */
    + oh->shadows_obj =
    + oh->inband_shadowed_obj_id;
    + oh->is_shrink =
    + oh->inband_is_shrink;
    + }
    +
    + if (!in) {
    + in = yaffs_find_or_create_by_number(dev, tags.obj_id, oh->type);
    + if (!in)
    + alloc_failed = 1;
    + }
    +
    + }
    +
    + if (!in) {
    + /* TODO Hoosterman we have a problem! */
    + T(YAFFS_TRACE_ERROR,
    + (TSTR
    + ("yaffs tragedy: Could not make object for object %d at chunk %d during scan"
    + TENDSTR), tags.obj_id, chunk));
    + continue;
    + }
    +
    + if (in->valid) {
    + /* We have already filled this one.
    + * We have a duplicate that will be discarded, but
    + * we first have to suck out resize info if it is a file.
    + */
    +
    + if ((in->variant_type ==
    + YAFFS_OBJECT_TYPE_FILE) && ((oh
    + &&
    + oh->
    + type
    + ==
    + YAFFS_OBJECT_TYPE_FILE)
    + ||
    + (tags.
    + extra_available
    + &&
    + tags.
    + extra_obj_type
    + ==
    + YAFFS_OBJECT_TYPE_FILE)))
    + {
    + u32 this_size =
    + (oh) ? oh->
    + file_size :
    + tags.extra_length;
    + u32 parent_obj_id =
    + (oh) ? oh->parent_obj_id :
    + tags.extra_parent_id;
    +
    + is_shrink =
    + (oh) ? oh->
    + is_shrink :
    + tags.extra_is_shrink;
    +
    + /* If it is deleted (unlinked at start also means deleted)
    + * we treat the file size as being zeroed at this point.
    + */
    + if (parent_obj_id ==
    + YAFFS_OBJECTID_DELETED
    + || parent_obj_id ==
    + YAFFS_OBJECTID_UNLINKED) {
    + this_size = 0;
    + is_shrink = 1;
    + }
    +
    + if (is_shrink
    + && in->variant.file_variant.
    + shrink_size > this_size)
    + in->variant.
    + file_variant.
    + shrink_size =
    + this_size;
    +
    + if (is_shrink)
    + bi->has_shrink_hdr = 1;
    +
    + }
    + /* Use existing - destroy this one. */
    + yaffs_chunk_del(dev, chunk, 1,
    + __LINE__);
    +
    + }
    +
    + if (!in->valid && in->variant_type !=
    + (oh ? oh->type : tags.extra_obj_type))
    + T(YAFFS_TRACE_ERROR,
    + (TSTR
    + ("yaffs tragedy: Bad object type, "
    + TCONT
    + ("%d != %d, for object %d at chunk ")
    + TCONT("%d during scan")
    + TENDSTR), oh ?
    + oh->type : tags.extra_obj_type,
    + in->variant_type, tags.obj_id,
    + chunk));
    +
    + if (!in->valid &&
    + (tags.obj_id == YAFFS_OBJECTID_ROOT ||
    + tags.obj_id ==
    + YAFFS_OBJECTID_LOSTNFOUND)) {
    + /* We only load some info, don't fiddle with directory structure */
    + in->valid = 1;
    +
    + if (oh) {
    +
    + in->yst_mode = oh->yst_mode;
    + yaffs_load_attribs(in, oh);
    + in->lazy_loaded = 0;
    + } else
    + in->lazy_loaded = 1;
    +
    + in->hdr_chunk = chunk;
    +
    + } else if (!in->valid) {
    + /* we need to load this info */
    +
    + in->valid = 1;
    + in->hdr_chunk = chunk;
    +
    + if (oh) {
    + in->variant_type = oh->type;
    +
    + in->yst_mode = oh->yst_mode;
    + yaffs_load_attribs(in, oh);
    +
    + if (oh->shadows_obj > 0)
    + yaffs_handle_shadowed_obj
    + (dev,
    + oh->shadows_obj,
    + 1);
    +
    + yaffs_set_obj_name_from_oh(in,
    + oh);
    + parent =
    + yaffs_find_or_create_by_number
    + (dev, oh->parent_obj_id,
    + YAFFS_OBJECT_TYPE_DIRECTORY);
    +
    + file_size = oh->file_size;
    + is_shrink = oh->is_shrink;
    + equiv_id = oh->equiv_id;
    +
    + } else {
    + in->variant_type =
    + tags.extra_obj_type;
    + parent =
    + yaffs_find_or_create_by_number
    + (dev, tags.extra_parent_id,
    + YAFFS_OBJECT_TYPE_DIRECTORY);
    + file_size = tags.extra_length;
    + is_shrink =
    + tags.extra_is_shrink;
    + equiv_id = tags.extra_equiv_id;
    + in->lazy_loaded = 1;
    +
    + }
    + in->dirty = 0;
    +
    + if (!parent)
    + alloc_failed = 1;
    +
    + /* directory stuff...
    + * hook up to parent
    + */
    +
    + if (parent && parent->variant_type ==
    + YAFFS_OBJECT_TYPE_UNKNOWN) {
    + /* Set up as a directory */
    + parent->variant_type =
    + YAFFS_OBJECT_TYPE_DIRECTORY;
    + INIT_LIST_HEAD(&parent->
    + variant.dir_variant.children);
    + } else if (!parent
    + || parent->variant_type !=
    + YAFFS_OBJECT_TYPE_DIRECTORY)
    + {
    + /* Hoosterman, another problem....
    + * We're trying to use a non-directory as a directory
    + */
    +
    + T(YAFFS_TRACE_ERROR,
    + (TSTR
    + ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
    + TENDSTR)));
    + parent = dev->lost_n_found;
    + }
    +
    + yaffs_add_obj_to_dir(parent, in);
    +
    + is_unlinked = (parent == dev->del_dir)
    + || (parent == dev->unlinked_dir);
    +
    + if (is_shrink) {
    + /* Mark the block as having a shrink header */
    + bi->has_shrink_hdr = 1;
    + }
    +
    + /* Note re hardlinks.
    + * Since we might scan a hardlink before its equivalent object is scanned
    + * we put them all in a list.
    + * After scanning is complete, we should have all the objects, so we run
    + * through this list and fix up all the chains.
    + */
    +
    + switch (in->variant_type) {
    + case YAFFS_OBJECT_TYPE_UNKNOWN:
    + /* Todo got a problem */
    + break;
    + case YAFFS_OBJECT_TYPE_FILE:
    +
    + if (in->variant.
    + file_variant.scanned_size <
    + file_size) {
    + /* This covers the case where the file size is greater
    + * than where the data is
    + * This will happen if the file is resized to be larger
    + * than its current data extents.
    + */
    + in->variant.
    + file_variant.
    + file_size =
    + file_size;
    + in->variant.
    + file_variant.
    + scanned_size =
    + file_size;
    + }
    +
    + if (in->variant.file_variant.
    + shrink_size > file_size)
    + in->variant.
    + file_variant.
    + shrink_size =
    + file_size;
    +
    + break;
    + case YAFFS_OBJECT_TYPE_HARDLINK:
    + if (!is_unlinked) {
    + in->variant.
    + hardlink_variant.
    + equiv_id = equiv_id;
    + in->hard_links.next =
    + (struct list_head *)
    + hard_list;
    + hard_list = in;
    + }
    + break;
    + case YAFFS_OBJECT_TYPE_DIRECTORY:
    + /* Do nothing */
    + break;
    + case YAFFS_OBJECT_TYPE_SPECIAL:
    + /* Do nothing */
    + break;
    + case YAFFS_OBJECT_TYPE_SYMLINK:
    + if (oh) {
    + in->variant.
    + symlink_variant.
    + alias =
    + yaffs_clone_str(oh->
    + alias);
    + if (!in->variant.
    + symlink_variant.
    + alias)
    + alloc_failed =
    + 1;
    + }
    + break;
    + }
    +
    + }
    +
    + }
    +
    + } /* End of scanning for each chunk */
    +
    + if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
    + /* If we got this far while scanning, then the block is fully allocated. */
    + state = YAFFS_BLOCK_STATE_FULL;
    + }
    +
    + bi->block_state = state;
    +
    + /* Now let's see if it was dirty */
    + if (bi->pages_in_use == 0 &&
    + !bi->has_shrink_hdr &&
    + bi->block_state == YAFFS_BLOCK_STATE_FULL) {
    + yaffs_block_became_dirty(dev, blk);
    + }
    +
    + }
    +
    + yaffs_skip_rest_of_block(dev);
    +
    + if (alt_block_index)
    + YFREE_ALT(block_index);
    + else
    + YFREE(block_index);
    +
    + /* Ok, we've done all the scanning.
    + * Fix up the hard link chains.
    + * We should now have scanned all the objects, now it's time to add these
    + * hardlinks.
    + */
    + yaffs_link_fixup(dev, hard_list);
    +
    + yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
    +
    + if (alloc_failed)
    + return YAFFS_FAIL;
    +
    + T(YAFFS_TRACE_SCAN, (TSTR("yaffs2_scan_backwards ends" TENDSTR)));
    +
    + return YAFFS_OK;
    +}
    diff --git a/fs/yaffs2/yaffs_yaffs2.h b/fs/yaffs2/yaffs_yaffs2.h
    new file mode 100644
    index 0000000..e1a9287
    --- /dev/null
    +++ b/fs/yaffs2/yaffs_yaffs2.h
    @@ -0,0 +1,39 @@
    +/*
    + * 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 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_YAFFS2_H__
    +#define __YAFFS_YAFFS2_H__
    +
    +#include "yaffs_guts.h"
    +
    +void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev);
    +void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev);
    +void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
    + struct yaffs_block_info *bi);
    +void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
    + struct yaffs_block_info *bi);
    +int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi);
    +u32 yaffs2_find_refresh_block(struct yaffs_dev *dev);
    +int yaffs2_checkpt_required(struct yaffs_dev *dev);
    +int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev);
    +
    +void yaffs2_checkpt_invalidate(struct yaffs_dev *dev);
    +int yaffs2_checkpt_save(struct yaffs_dev *dev);
    +int yaffs2_checkpt_restore(struct yaffs_dev *dev);
    +
    +int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size);
    +int yaffs2_scan_backwards(struct yaffs_dev *dev);
    +
    +#endif
    --
    1.7.1


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