yaffs Reactoring WIP
[yaffs2.git] / yaffs_yaffs1.c
diff --git a/yaffs_yaffs1.c b/yaffs_yaffs1.c
new file mode 100644 (file)
index 0000000..bcfd594
--- /dev/null
@@ -0,0 +1,460 @@
+/*
+ * 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;
+                                       }
+
+                               }
+
+                               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_SetObjectName(in, oh->name);
+                                       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;
+}
+