If kernel/config.h is included in yportenv.h, then yportenv.h must be

[yaffs2.git] / yaffs_packedtags2.c

diff --git a/yaffs_packedtags2.c b/yaffs_packedtags2.c
index f734882e47245fed67187ee72721fb3abe7beeda..342e550e24420e4ee6d8ec0fce9c0b1c8aee88b3 100644 (file)
--- a/yaffs_packedtags2.c
+++ b/yaffs_packedtags2.c
@@ -1,34 +1,123 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system. 
+ *
+ * yaffs_packedtags2.c: Tags packing for YAFFS2
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *
+ * 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 Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ */
+ 
 #include "yaffs_packedtags2.h"
 #include "yportenv.h"
+#include "yaffs_tagsvalidity.h"
 
 
 
-void yaffs_PackTags2(yaffs_PackedTags2 *pt, yaffs_ExtendedTags *t)
+// This code packs a set of extended tags into a binary structure for NAND storage
+
+// Some of the information is "extra" struff which can be packed in to speed scanning
+// This is defined by having the EXTRA_HEADER_INFO_FLAG set.
+
+
+// Extra flags applied to chunkId
+
+#define EXTRA_HEADER_INFO_FLAG 0x80000000
+#define EXTRA_SHRINK_FLAG      0x40000000
+#define EXTRA_SPARE_FLAGS      0x30000000
+
+#define ALL_EXTRA_FLAGS                0xF0000000
+
+
+
+// Also, the top 4 bits of the object Id are set to the object type.
+#define EXTRA_OBJECT_TYPE_SHIFT (28)
+#define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
+
+
+
+static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 *pt)
+{
+       T(YAFFS_TRACE_MTD,(TSTR("packed tags obj %d chunk %d byte %d seq %d"TENDSTR),pt->t.objectId,pt->t.chunkId,pt->t.byteCount,pt->t.sequenceNumber));
+}
+
+static void yaffs_DumpTags2(const yaffs_ExtendedTags *t)
+{
+       T(YAFFS_TRACE_MTD,(TSTR("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d"TENDSTR),
+            t->eccResult, t->blockBad, t->chunkUsed, t->objectId, t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber, t->sequenceNumber));
+         
+}
+
+void yaffs_PackTags2(yaffs_PackedTags2 *pt, const yaffs_ExtendedTags *t)
 {
        pt->t.chunkId = t->chunkId;
        pt->t.sequenceNumber = t->sequenceNumber;
        pt->t.byteCount = t->byteCount;
        pt->t.objectId = t->objectId;
        
-       yaffs_ECCCalculateOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&pt->ecc);
+       if(t->chunkId == 0 && t->extraHeaderInfoAvailable)
+       {
+               // Store the extra header info instead
+               pt->t.chunkId = EXTRA_HEADER_INFO_FLAG | t->extraParentObjectId; // We save the parent object in the chunkId
+               if(t->extraIsShrinkHeader) 
+               {
+                   pt->t.chunkId |= EXTRA_SHRINK_FLAG;
+               }
+               
+               pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+               pt->t.objectId |= (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
+                
+               if(t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK)
+               {
+                  pt->t.byteCount = t->extraEquivalentObjectId;
+               }
+               else if(t->extraObjectType == YAFFS_OBJECT_TYPE_FILE)
+               {
+                  pt->t.byteCount = t->extraFileLength;
+               }
+               else
+               {
+                  pt->t.byteCount = 0;
+               }
+       }
+       
+       yaffs_DumpPackedTags2(pt);
+       yaffs_DumpTags2(t);
        
+#ifndef YAFFS_IGNORE_TAGS_ECC
+       { 
+         yaffs_ECCCalculateOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&pt->ecc);
+       }
+#endif
 }
 
 void yaffs_UnpackTags2(yaffs_ExtendedTags *t, yaffs_PackedTags2 *pt)
 {
 
        
-       if(pt->t.sequenceNumber == 0xFFFFFFFF)
-       {
-               memset(t,0,sizeof(yaffs_ExtendedTags));
-               
-       }
-       else
+       memset(t,0,sizeof(yaffs_ExtendedTags));
+       
+       yaffs_InitialiseTags(t);
+       
+       if(pt->t.sequenceNumber != 0xFFFFFFFF)
        {
                // Page is in use
-               yaffs_ECCOther ecc;
-               yaffs_ECCCalculateOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&ecc);
-               t->eccResult = yaffs_ECCCorrectOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&pt->ecc,&ecc);
+#ifdef YAFFS_IGNORE_TAGS_ECC
+               {
+                       t->eccResult = 0;
+               }
+#else
+               {
+                       yaffs_ECCOther ecc;
+                       yaffs_ECCCalculateOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&ecc);
+                       t->eccResult = yaffs_ECCCorrectOther((unsigned char *)&pt->t,sizeof(yaffs_PackedTags2TagsPart),&pt->ecc,&ecc);
+               }
+#endif
                t->blockBad = 0;
                t->chunkUsed = 1;
                t->objectId = pt->t.objectId;
@@ -37,6 +126,33 @@ void yaffs_UnpackTags2(yaffs_ExtendedTags *t, yaffs_PackedTags2 *pt)
                t->chunkDeleted = 0;
                t->serialNumber = 0;
                t->sequenceNumber = pt->t.sequenceNumber;
+               
+               // Do extra header info stuff
+               
+               if(pt->t.chunkId & EXTRA_HEADER_INFO_FLAG)
+               {
+                       t->chunkId = 0;
+                       t->byteCount = 0;
+                       
+                       t->extraHeaderInfoAvailable = 1;
+                       t->extraParentObjectId = pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
+                       t->extraIsShrinkHeader =  (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                       t->extraObjectType = pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
+                       t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+                       
+                       if(t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK)
+                       {
+                           t->extraEquivalentObjectId = pt->t.byteCount;
+                       }
+                       else 
+                       {
+                           t->extraFileLength = pt->t.byteCount;
+                       }
+               }
        }
+
+       yaffs_DumpPackedTags2(pt);
+       yaffs_DumpTags2(t);
+
 }