+/*
+ * yaffs_FindRefreshBlock()
+ * periodically finds the oldest full block by sequence number for refreshing.
+ * Only for yaffs2.
+ */
+static __u32 yaffs_FindRefreshBlock(yaffs_Device *dev)
+{
+ __u32 b ;
+
+ __u32 oldest = 0;
+ __u32 oldestSequence = 0;
+
+ yaffs_BlockInfo *bi;
+
+ /*
+ * If refresh period < 10 then refreshing is disabled.
+ */
+ if(dev->param.refreshPeriod < 10 ||
+ !dev->param.isYaffs2)
+ return oldest;
+
+ /*
+ * Fix broken values.
+ */
+ if(dev->refreshSkip > dev->param.refreshPeriod)
+ dev->refreshSkip = dev->param.refreshPeriod;
+
+ if(dev->refreshSkip > 0){
+ dev->refreshSkip--;
+ return oldest;
+ }
+
+ /*
+ * Refresh skip is now zero.
+ * We'll do a refresh this time around....
+ * Update the refresh skip and find the oldest block.
+ */
+ dev->refreshSkip = dev->param.refreshPeriod;
+ dev->refreshCount++;
+
+ for (b = dev->internalStartBlock; b <=dev->internalEndBlock; b++){
+
+ bi = yaffs_GetBlockInfo(dev, b);
+
+
+ if (bi->blockState == YAFFS_BLOCK_STATE_FULL){
+
+ if(oldest < 1 ||
+ bi->sequenceNumber < oldestSequence){
+ oldest = b;
+ oldestSequence = bi->sequenceNumber;
+ }
+ }
+ }
+
+ if (oldest > 0) {
+ T(YAFFS_TRACE_GC,
+ (TSTR("GC refresh count %d selected block %d with sequenceNumber %d" TENDSTR),
+ dev->refreshCount, oldest, oldestSequence));
+ }
+
+ return oldest;
+}
+
+/*
+ * FindDiretiestBlock is used to select the dirtiest block (or close enough)