466 lines
12 KiB
C

/*
* 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"
int yaffs1_Scan(yaffs_Device *dev)
{
yaffs_ExtendedTags tags;
int blk;
int blockIterator;
int startIterator;
int endIterator;
int result;
int chunk;
int c;
int deleted;
yaffs_BlockState state;
yaffs_Object *hardList = NULL;
yaffs_BlockInfo *bi;
__u32 sequenceNumber;
yaffs_ObjectHeader *oh;
yaffs_Object *in;
yaffs_Object *parent;
int alloc_failed = 0;
struct yaffs_ShadowFixerStruct *shadowFixerList = NULL;
__u8 *chunkData;
T(YAFFS_TRACE_SCAN,
(TSTR("yaffs1_Scan starts intstartblk %d intendblk %d..." TENDSTR),
dev->internalStartBlock, dev->internalEndBlock));
chunkData = yaffs_GetTempBuffer(dev, __LINE__);
dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
/* Scan all the blocks to determine their state */
bi = dev->blockInfo;
for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
yaffs_ClearChunkBits(dev, blk);
bi->pagesInUse = 0;
bi->softDeletions = 0;
yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);
bi->blockState = state;
bi->sequenceNumber = sequenceNumber;
if (bi->sequenceNumber == YAFFS_SEQUENCE_BAD_BLOCK)
bi->blockState = state = YAFFS_BLOCK_STATE_DEAD;
T(YAFFS_TRACE_SCAN_DEBUG,
(TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
state, sequenceNumber));
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->nErasedBlocks++;
dev->nFreeChunks += dev->param.nChunksPerBlock;
}
bi++;
}
startIterator = dev->internalStartBlock;
endIterator = dev->internalEndBlock;
/* For each block.... */
for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
blockIterator++) {
YYIELD();
YYIELD();
blk = blockIterator;
bi = yaffs_GetBlockInfo(dev, blk);
state = bi->blockState;
deleted = 0;
/* For each chunk in each block that needs scanning....*/
for (c = 0; !alloc_failed && c < dev->param.nChunksPerBlock &&
state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
/* Read the tags and decide what to do */
chunk = blk * dev->param.nChunksPerBlock + c;
result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
&tags);
/* Let's have a good look at this chunk... */
if (tags.eccResult == YAFFS_ECC_RESULT_UNFIXED || tags.chunkDeleted) {
/* YAFFS1 only...
* A deleted chunk
*/
deleted++;
dev->nFreeChunks++;
/*T((" %d %d deleted\n",blk,c)); */
} else if (!tags.chunkUsed) {
/* 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->nErasedBlocks++;
} 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->allocationBlock = blk;
dev->allocationPage = c;
dev->allocationBlockFinder = blk;
/* Set block finder here to encourage the allocator to go forth from here. */
}
dev->nFreeChunks += (dev->param.nChunksPerBlock - c);
} else if (tags.chunkId > 0) {
/* chunkId > 0 so it is a data chunk... */
unsigned int endpos;
yaffs_SetChunkBit(dev, blk, c);
bi->pagesInUse++;
in = yaffs_FindOrCreateObjectByNumber(dev,
tags.
objectId,
YAFFS_OBJECT_TYPE_FILE);
/* PutChunkIntoFile checks for a clash (two data chunks with
* the same chunkId).
*/
if (!in)
alloc_failed = 1;
if (in) {
if (!yaffs_PutChunkIntoFile(in, tags.chunkId, chunk, 1))
alloc_failed = 1;
}
endpos =
(tags.chunkId - 1) * dev->nDataBytesPerChunk +
tags.byteCount;
if (in &&
in->variantType == YAFFS_OBJECT_TYPE_FILE
&& in->variant.fileVariant.scannedFileSize <
endpos) {
in->variant.fileVariant.
scannedFileSize = endpos;
if (!dev->param.useHeaderFileSize) {
in->variant.fileVariant.
fileSize =
in->variant.fileVariant.
scannedFileSize;
}
}
/* T((" %d %d data %d %d\n",blk,c,tags.objectId,tags.chunkId)); */
} else {
/* chunkId == 0, so it is an ObjectHeader.
* Thus, we read in the object header and make the object
*/
yaffs_SetChunkBit(dev, blk, c);
bi->pagesInUse++;
result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk,
chunkData,
NULL);
oh = (yaffs_ObjectHeader *) chunkData;
in = yaffs_FindObjectByNumber(dev,
tags.objectId);
if (in && in->variantType != oh->type) {
/* This should not happen, but somehow
* Wev'e ended up with an objectId that has been reused but not yet
* deleted, and worse still it has changed type. Delete the old object.
*/
yaffs_DeleteObject(in);
in = 0;
}
in = yaffs_FindOrCreateObjectByNumber(dev,
tags.
objectId,
oh->type);
if (!in)
alloc_failed = 1;
if (in && oh->shadowsObject > 0) {
struct yaffs_ShadowFixerStruct *fixer;
fixer = YMALLOC(sizeof(struct yaffs_ShadowFixerStruct));
if (fixer) {
fixer->next = shadowFixerList;
shadowFixerList = fixer;
fixer->objectId = tags.objectId;
fixer->shadowedId = oh->shadowsObject;
T(YAFFS_TRACE_SCAN,
(TSTR
(" Shadow fixer: %d shadows %d" TENDSTR),
fixer->objectId, fixer->shadowedId));
}
}
if (in && in->valid) {
/* We have already filled this one. We have a duplicate and need to resolve it. */
unsigned existingSerial = in->serial;
unsigned newSerial = tags.serialNumber;
if (((existingSerial + 1) & 3) == newSerial) {
/* Use new one - destroy the exisiting one */
yaffs_DeleteChunk(dev,
in->hdrChunk,
1, __LINE__);
in->valid = 0;
} else {
/* Use existing - destroy this one. */
yaffs_DeleteChunk(dev, chunk, 1,
__LINE__);
}
}
if (in && !in->valid &&
(tags.objectId == YAFFS_OBJECTID_ROOT ||
tags.objectId == YAFFS_OBJECTID_LOSTNFOUND)) {
/* We only load some info, don't fiddle with directory structure */
in->valid = 1;
in->variantType = oh->type;
in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
in->win_atime[0] = oh->win_atime[0];
in->win_ctime[0] = oh->win_ctime[0];
in->win_mtime[0] = oh->win_mtime[0];
in->win_atime[1] = oh->win_atime[1];
in->win_ctime[1] = oh->win_ctime[1];
in->win_mtime[1] = oh->win_mtime[1];
#else
in->yst_uid = oh->yst_uid;
in->yst_gid = oh->yst_gid;
in->yst_atime = oh->yst_atime;
in->yst_mtime = oh->yst_mtime;
in->yst_ctime = oh->yst_ctime;
in->yst_rdev = oh->yst_rdev;
#endif
in->hdrChunk = chunk;
in->serial = tags.serialNumber;
} else if (in && !in->valid) {
/* we need to load this info */
in->valid = 1;
in->variantType = oh->type;
in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
in->win_atime[0] = oh->win_atime[0];
in->win_ctime[0] = oh->win_ctime[0];
in->win_mtime[0] = oh->win_mtime[0];
in->win_atime[1] = oh->win_atime[1];
in->win_ctime[1] = oh->win_ctime[1];
in->win_mtime[1] = oh->win_mtime[1];
#else
in->yst_uid = oh->yst_uid;
in->yst_gid = oh->yst_gid;
in->yst_atime = oh->yst_atime;
in->yst_mtime = oh->yst_mtime;
in->yst_ctime = oh->yst_ctime;
in->yst_rdev = oh->yst_rdev;
#endif
in->hdrChunk = chunk;
in->serial = tags.serialNumber;
yaffs_SetObjectNameFromOH(in, oh);
in->dirty = 0;
/* directory stuff...
* hook up to parent
*/
parent =
yaffs_FindOrCreateObjectByNumber
(dev, oh->parentObjectId,
YAFFS_OBJECT_TYPE_DIRECTORY);
if (!parent)
alloc_failed = 1;
if (parent && parent->variantType ==
YAFFS_OBJECT_TYPE_UNKNOWN) {
/* Set up as a directory */
parent->variantType =
YAFFS_OBJECT_TYPE_DIRECTORY;
YINIT_LIST_HEAD(&parent->variant.
directoryVariant.
children);
} else if (!parent || parent->variantType !=
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->lostNFoundDir;
}
yaffs_AddObjectToDirectory(parent, in);
if (0 && (parent == dev->deletedDir ||
parent == dev->unlinkedDir)) {
in->deleted = 1; /* If it is unlinked at start up then it wants deleting */
dev->nDeletedFiles++;
}
/* 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->variantType) {
case YAFFS_OBJECT_TYPE_UNKNOWN:
/* Todo got a problem */
break;
case YAFFS_OBJECT_TYPE_FILE:
if (dev->param.useHeaderFileSize)
in->variant.fileVariant.
fileSize =
oh->fileSize;
break;
case YAFFS_OBJECT_TYPE_HARDLINK:
in->variant.hardLinkVariant.
equivalentObjectId =
oh->equivalentObjectId;
in->hardLinks.next =
(struct ylist_head *)
hardList;
hardList = 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.symLinkVariant.alias =
yaffs_CloneString(oh->alias);
if (!in->variant.symLinkVariant.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->allocationBlock = -1;
}
bi->blockState = state;
/* Now let's see if it was dirty */
if (bi->pagesInUse == 0 &&
!bi->hasShrinkHeader &&
bi->blockState == YAFFS_BLOCK_STATE_FULL) {
yaffs_BlockBecameDirty(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_HardlinkFixup(dev, hardList);
/* Fix up any shadowed objects */
{
struct yaffs_ShadowFixerStruct *fixer;
yaffs_Object *obj;
while (shadowFixerList) {
fixer = shadowFixerList;
shadowFixerList = fixer->next;
/* Complete the rename transaction by deleting the shadowed object
* then setting the object header to unshadowed.
*/
obj = yaffs_FindObjectByNumber(dev, fixer->shadowedId);
if (obj)
yaffs_DeleteObject(obj);
obj = yaffs_FindObjectByNumber(dev, fixer->objectId);
if (obj)
yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0, NULL);
YFREE(fixer);
}
}
yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
if (alloc_failed)
return YAFFS_FAIL;
T(YAFFS_TRACE_SCAN, (TSTR("yaffs1_Scan ends" TENDSTR)));
return YAFFS_OK;
}