- return theOne >= 0 ? &dev->srCache[theOne] : NULL;
- } else {
- return NULL;
- }
-
-}
-
-static yaffs_ChunkCache *yaffs_GrabChunkCache(yaffs_Device * dev)
-{
- yaffs_ChunkCache *cache;
- yaffs_Object *theObj;
- int usage;
- int i;
- int pushout;
-
- if (dev->nShortOpCaches > 0) {
- /* Try find a non-dirty one... */
-
- cache = yaffs_GrabChunkCacheWorker(dev);
-
- if (!cache) {
- /* They were all dirty, find the last recently used object and flush
- * its cache, then find again.
- * NB what's here is not very accurate, we actually flush the object
- * the last recently used page.
- */
-
- /* With locking we can't assume we can use entry zero */
-
- theObj = NULL;
- usage = -1;
- cache = NULL;
- pushout = -1;
-
- for (i = 0; i < dev->nShortOpCaches; i++) {
- if (dev->srCache[i].object &&
- !dev->srCache[i].locked &&
- (dev->srCache[i].lastUse < usage || !cache))
- {
- usage = dev->srCache[i].lastUse;
- theObj = dev->srCache[i].object;
- cache = &dev->srCache[i];
- pushout = i;
- }
- }
-
- if (!cache || cache->dirty) {
- /* Flush and try again */
- yaffs_FlushFilesChunkCache(theObj);
- cache = yaffs_GrabChunkCacheWorker(dev);
- }
-
- }
- 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- * ie the short cache for this page is no longer valid.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;
- }
- }
- }
-}
-
-/*--------------------- File read/write ------------------------
- * Read and write have very similar structures.
- * In general the read/write has three parts to it
- * An incomplete chunk to start with (if the read/write is not chunk-aligned)
- * Some complete chunks
- * An incomplete chunk to end off with
- *
- * Curve-balls: the first chunk might also be the last chunk.
- */
-
-int yaffs_ReadDataFromFile(yaffs_Object * in, __u8 * buffer, __u32 offset,
- int nBytes)
-{
-
- int chunk;
- int start;
- int nToCopy;
- int n = nBytes;
- int nDone = 0;
- yaffs_ChunkCache *cache;
-
- yaffs_Device *dev;
-
- dev = in->myDev;
-
- while (n > 0) {
- chunk = offset / dev->nBytesPerChunk + 1; /* The first chunk is 1 */
- start = offset % dev->nBytesPerChunk;
-
- /* OK now check for the curveball where the start and end are in
- * the same chunk.
- */
- if ((start + n) < dev->nBytesPerChunk) {
- nToCopy = n;
- } else {
- nToCopy = dev->nBytesPerChunk - start;
- }
-
- cache = yaffs_FindChunkCache(in, chunk);
-
- /* If the chunk is already in the cache or it is less than a whole chunk
- * then use the cache (if there is caching)
- * else bypass the cache.
- */
- if (cache || nToCopy != dev->nBytesPerChunk) {
- if (dev->nShortOpCaches > 0) {
-
- /* If we can't find the data in the cache, then load it up. */
-
- if (!cache) {
- cache = yaffs_GrabChunkCache(in->myDev);
- cache->object = in;
- cache->chunkId = chunk;
- cache->dirty = 0;
- cache->locked = 0;
- yaffs_ReadChunkDataFromObject(in, chunk,
- cache->
- data);
- cache->nBytes = 0;
- }
-
- yaffs_UseChunkCache(dev, cache, 0);
-
- cache->locked = 1;
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
- memcpy(buffer, &cache->data[start], nToCopy);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
-#endif
- cache->locked = 0;
- } else {
- /* Read into the local buffer then copy..*/
-
- __u8 *localBuffer =
- yaffs_GetTempBuffer(dev, __LINE__);
- yaffs_ReadChunkDataFromObject(in, chunk,
- localBuffer);
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
- memcpy(buffer, &localBuffer[start], nToCopy);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
-#endif
- yaffs_ReleaseTempBuffer(dev, localBuffer,
- __LINE__);
- }
-
- } else {
-#ifdef CONFIG_YAFFS_WINCE
- __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
-
- /* Under WinCE can't do direct transfer. Need to use a local buffer.
- * This is because we otherwise screw up WinCE's memory mapper
- */
- yaffs_ReadChunkDataFromObject(in, chunk, localBuffer);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
- memcpy(buffer, localBuffer, dev->nBytesPerChunk);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
- yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
-#endif
-
-#else
- /* A full chunk. Read directly into the supplied buffer. */
- yaffs_ReadChunkDataFromObject(in, chunk, buffer);
-#endif
- }
-
- n -= nToCopy;
- offset += nToCopy;
- buffer += nToCopy;
- nDone += nToCopy;
-
- }
-
- return nDone;
-}
-
-int yaffs_WriteDataToFile(yaffs_Object * in, const __u8 * buffer, __u32 offset,
- int nBytes, int writeThrough)
-{
-
- int chunk;
- int start;
- int nToCopy;
- int n = nBytes;
- int nDone = 0;
- int nToWriteBack;
- int startOfWrite = offset;
- int chunkWritten = 0;
- int nBytesRead;
-
- yaffs_Device *dev;
-
- dev = in->myDev;
-
- while (n > 0 && chunkWritten >= 0) {
- chunk = offset / dev->nBytesPerChunk + 1;
- start = offset % dev->nBytesPerChunk;
-
- /* OK now check for the curveball where the start and end are in
- * the same chunk.
- */
-
- if ((start + n) < dev->nBytesPerChunk) {
- nToCopy = n;
-
- /* Now folks, to calculate how many bytes to write back....
- * If we're overwriting and not writing to then end of file then
- * we need to write back as much as was there before.
- */
-
- nBytesRead =
- in->variant.fileVariant.fileSize -
- ((chunk - 1) * dev->nBytesPerChunk);
-
- if (nBytesRead > dev->nBytesPerChunk) {
- nBytesRead = dev->nBytesPerChunk;
- }
-
- nToWriteBack =
- (nBytesRead >
- (start + n)) ? nBytesRead : (start + n);
-
- } else {
- nToCopy = dev->nBytesPerChunk - start;
- nToWriteBack = dev->nBytesPerChunk;
- }
-
- if (nToCopy != dev->nBytesPerChunk) {
- /* An incomplete start or end chunk (or maybe both start and end chunk) */
- if (dev->nShortOpCaches > 0) {
- yaffs_ChunkCache *cache;
- /* If we can't find the data in the cache, then load the cache */
- cache = yaffs_FindChunkCache(in, chunk);
- if (!cache
- && yaffs_CheckSpaceForAllocation(in->
- myDev)) {
- cache = yaffs_GrabChunkCache(in->myDev);
- cache->object = in;
- cache->chunkId = chunk;
- cache->dirty = 0;
- cache->locked = 0;
- yaffs_ReadChunkDataFromObject(in, chunk,
- cache->
- data);
- }
-
- if (cache) {
- yaffs_UseChunkCache(dev, cache, 1);
- cache->locked = 1;
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
-
- memcpy(&cache->data[start], buffer,
- nToCopy);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
-#endif
- cache->locked = 0;
- cache->nBytes = nToWriteBack;
-
- if (writeThrough) {
- chunkWritten =
- yaffs_WriteChunkDataToObject
- (cache->object,
- cache->chunkId,
- cache->data, cache->nBytes,
- 1);
- cache->dirty = 0;
- }
-
- } else {
- chunkWritten = -1; /* fail the write */
- }
- } else {
- /* An incomplete start or end chunk (or maybe both start and end chunk)
- * Read into the local buffer then copy, then copy over and write back.
- */
-
- __u8 *localBuffer =
- yaffs_GetTempBuffer(dev, __LINE__);
-
- yaffs_ReadChunkDataFromObject(in, chunk,
- localBuffer);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
-
- memcpy(&localBuffer[start], buffer, nToCopy);
-
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
-#endif
- chunkWritten =
- yaffs_WriteChunkDataToObject(in, chunk,
- localBuffer,
- nToWriteBack,
- 0);
-
- yaffs_ReleaseTempBuffer(dev, localBuffer,
- __LINE__);
-
- }
-
- } else {
-
-#ifdef CONFIG_YAFFS_WINCE
- /* Under WinCE can't do direct transfer. Need to use a local buffer.
- * This is because we otherwise screw up WinCE's memory mapper
- */
- __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_UnlockYAFFS(TRUE);
-#endif
- memcpy(localBuffer, buffer, dev->nBytesPerChunk);
-#ifdef CONFIG_YAFFS_WINCE
- yfsd_LockYAFFS(TRUE);
-#endif
- chunkWritten =
- yaffs_WriteChunkDataToObject(in, chunk, localBuffer,
- dev->nBytesPerChunk,
- 0);
- yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
-#else
- /* A full chunk. Write directly from the supplied buffer. */
- chunkWritten =
- yaffs_WriteChunkDataToObject(in, chunk, buffer,
- dev->nBytesPerChunk,
- 0);
-#endif
- /* Since we've overwritten the cached data, we better invalidate it. */
- yaffs_InvalidateChunkCache(in, chunk);
- }
-
- if (chunkWritten >= 0) {
- n -= nToCopy;
- offset += nToCopy;
- buffer += nToCopy;
- nDone += nToCopy;
- }
-
- }
-
- /* Update file object */
-
- if ((startOfWrite + nDone) > in->variant.fileVariant.fileSize) {
- in->variant.fileVariant.fileSize = (startOfWrite + nDone);
- }
-
- in->dirty = 1;
-
- return nDone;
-}
-
-
-/* ---------------------- File resizing stuff ------------------ */
-
-static void yaffs_PruneResizedChunks(yaffs_Object * in, int newSize)
-{
-
- yaffs_Device *dev = in->myDev;
- int oldFileSize = in->variant.fileVariant.fileSize;
-
- int lastDel = 1 + (oldFileSize - 1) / dev->nBytesPerChunk;
-
- int startDel = 1 + (newSize + dev->nBytesPerChunk - 1) /
- dev->nBytesPerChunk;
- int i;
- int chunkId;
-