/*
* 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;
yaffs_trace(YAFFS_TRACE_SCAN,
"yaffs1_scan starts intstartblk %d intendblk %d...",
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;
yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
"Block scanning block %d state %d seq %d",
blk, state, seq_number);
if (state == YAFFS_BLOCK_STATE_DEAD) {
yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
"block %d is bad", blk);
} else if (state == YAFFS_BLOCK_STATE_EMPTY) {
yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
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++) {
cond_resched();
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 */
yaffs_trace(YAFFS_TRACE_SCAN,
" Allocating from %d %d",
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 =
kmalloc(sizeof
(struct yaffs_shadow_fixer),
GFP_NOFS);
if (fixer) {
fixer->next = shadow_fixers;
shadow_fixers = fixer;
fixer->obj_id = tags.obj_id;
fixer->shadowed_id =
oh->shadows_obj;
yaffs_trace(YAFFS_TRACE_SCAN,
" Shadow fixer: %d shadows %d",
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
*/
yaffs_trace(YAFFS_TRACE_ERROR,
"yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
);
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);
kfree(fixer);
}
}
yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
if (alloc_failed)
return YAFFS_FAIL;
yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
return YAFFS_OK;
}