+ return cache;
+ } else
+ return NULL;
+
+}
+
+/* Find a cached chunk */
+static yaffs_ChunkCache *yaffs_FindChunkCache(const yaffs_Object * obj,
+ int chunkId)
+{
+ yaffs_Device *dev = obj->myDev;
+ int i;
+ if (dev->nShortOpCaches > 0) {
+ for (i = 0; i < dev->nShortOpCaches; i++) {
+ if (dev->srCache[i].object == obj &&
+ dev->srCache[i].chunkId == chunkId) {
+ dev->cacheHits++;
+
+ return &dev->srCache[i];
+ }
+ }
+ }
+ return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_UseChunkCache(yaffs_Device * dev, yaffs_ChunkCache * cache,
+ int isAWrite)
+{
+
+ if (dev->nShortOpCaches > 0) {
+ if (dev->srLastUse < 0 || dev->srLastUse > 100000000) {
+ /* Reset the cache usages */
+ int i;
+ for (i = 1; i < dev->nShortOpCaches; i++) {
+ dev->srCache[i].lastUse = 0;
+ }
+ dev->srLastUse = 0;
+ }
+
+ dev->srLastUse++;
+
+ cache->lastUse = dev->srLastUse;
+
+ if (isAWrite) {
+ cache->dirty = 1;
+ }
+ }
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId)
+{
+ if (object->myDev->nShortOpCaches > 0) {
+ yaffs_ChunkCache *cache = yaffs_FindChunkCache(object, chunkId);
+
+ if (cache) {
+ cache->object = NULL;
+ }
+ }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in)
+{
+ int i;
+ yaffs_Device *dev = in->myDev;
+
+ if (dev->nShortOpCaches > 0) {
+ /* Invalidate it. */
+ for (i = 0; i < dev->nShortOpCaches; i++) {
+ if (dev->srCache[i].object == in) {
+ dev->srCache[i].object = NULL;
+ }
+ }
+ }
+}
+
+/*--------------------- Checkpointing --------------------*/
+
+
+static int yaffs_WriteCheckpointValidityMarker(yaffs_Device *dev,int head)
+{
+ yaffs_CheckpointValidity cp;
+
+ memset(&cp,0,sizeof(cp));
+
+ cp.structType = sizeof(cp);
+ cp.magic = YAFFS_MAGIC;
+ cp.version = YAFFS_CHECKPOINT_VERSION;
+ cp.head = (head) ? 1 : 0;
+
+ return (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp))?
+ 1 : 0;
+}
+
+static int yaffs_ReadCheckpointValidityMarker(yaffs_Device *dev, int head)
+{
+ yaffs_CheckpointValidity cp;
+ int ok;
+
+ ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
+
+ if(ok)
+ ok = (cp.structType == sizeof(cp)) &&
+ (cp.magic == YAFFS_MAGIC) &&
+ (cp.version == YAFFS_CHECKPOINT_VERSION) &&
+ (cp.head == ((head) ? 1 : 0));
+ return ok ? 1 : 0;
+}
+
+static void yaffs_DeviceToCheckpointDevice(yaffs_CheckpointDevice *cp,
+ yaffs_Device *dev)
+{
+ cp->nErasedBlocks = dev->nErasedBlocks;
+ cp->allocationBlock = dev->allocationBlock;
+ cp->allocationPage = dev->allocationPage;
+ cp->nFreeChunks = dev->nFreeChunks;
+
+ cp->nDeletedFiles = dev->nDeletedFiles;
+ cp->nUnlinkedFiles = dev->nUnlinkedFiles;
+ cp->nBackgroundDeletions = dev->nBackgroundDeletions;
+ cp->sequenceNumber = dev->sequenceNumber;
+ cp->oldestDirtySequence = dev->oldestDirtySequence;
+
+}
+
+static void yaffs_CheckpointDeviceToDevice(yaffs_Device *dev,
+ yaffs_CheckpointDevice *cp)
+{
+ dev->nErasedBlocks = cp->nErasedBlocks;
+ dev->allocationBlock = cp->allocationBlock;
+ dev->allocationPage = cp->allocationPage;
+ dev->nFreeChunks = cp->nFreeChunks;
+
+ dev->nDeletedFiles = cp->nDeletedFiles;
+ dev->nUnlinkedFiles = cp->nUnlinkedFiles;
+ dev->nBackgroundDeletions = cp->nBackgroundDeletions;
+ dev->sequenceNumber = cp->sequenceNumber;
+ dev->oldestDirtySequence = cp->oldestDirtySequence;
+}
+
+
+static int yaffs_WriteCheckpointDevice(yaffs_Device *dev)
+{
+ yaffs_CheckpointDevice cp;
+ __u32 nBytes;
+ __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);
+
+ int ok;
+
+ /* Write device runtime values*/
+ yaffs_DeviceToCheckpointDevice(&cp,dev);
+ cp.structType = sizeof(cp);
+
+ ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));
+
+ /* Write block info */
+ if(ok) {
+ nBytes = nBlocks * sizeof(yaffs_BlockInfo);
+ ok = (yaffs_CheckpointWrite(dev,dev->blockInfo,nBytes) == nBytes);
+ }