Improve handling of ecc on tags
[yaffs2.git] / yaffs_packedtags2.c
index 5cc68af..3f9a815 100644 (file)
@@ -1,16 +1,14 @@
 /*
- * YAFFS: Yet another FFS. A NAND-flash specific file system. 
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
  *
- * yaffs_packedtags2.c: Tags packing for YAFFS2
- *
- * Copyright (C) 2002 Aleph One Ltd.
+ * Copyright (C) 2002-2007 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 Lesser General Public License
- * version 2.1 as published by the Free Software Foundation.
+ * 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_packedtags2.h"
 #define EXTRA_OBJECT_TYPE_SHIFT (28)
 #define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
 
-static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
+
+static void yaffs_DumpPackedTags2TagsPart(const yaffs_PackedTags2TagsPart * ptt)
 {
        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));
+          ptt->objectId, ptt->chunkId, ptt->byteCount,
+          ptt->sequenceNumber));
+}
+static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
+{
+       yaffs_DumpPackedTags2TagsPart(&pt->t);
 }
 
 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"
+          ("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)
+void yaffs_PackTags2TagsPart(yaffs_PackedTags2TagsPart * ptt, const yaffs_ExtendedTags * t)
 {
-       pt->t.chunkId = t->chunkId;
-       pt->t.sequenceNumber = t->sequenceNumber;
-       pt->t.byteCount = t->byteCount;
-       pt->t.objectId = t->objectId;
+       ptt->chunkId = t->chunkId;
+       ptt->sequenceNumber = t->sequenceNumber;
+       ptt->byteCount = t->byteCount;
+       ptt->objectId = t->objectId;
 
        if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
                /* Store the extra header info instead */
                /* We save the parent object in the chunkId */
-               pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
+               ptt->chunkId = EXTRA_HEADER_INFO_FLAG
                        | t->extraParentObjectId;
                if (t->extraIsShrinkHeader) {
-                       pt->t.chunkId |= EXTRA_SHRINK_FLAG;
+                       ptt->chunkId |= EXTRA_SHRINK_FLAG;
                }
                if (t->extraShadows) {
-                       pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
+                       ptt->chunkId |= EXTRA_SHADOWS_FLAG;
                }
 
-               pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
-               pt->t.objectId |=
+               ptt->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+               ptt->objectId |=
                    (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
 
                if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
-                       pt->t.byteCount = t->extraEquivalentObjectId;
+                       ptt->byteCount = t->extraEquivalentObjectId;
                } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
-                       pt->t.byteCount = t->extraFileLength;
+                       ptt->byteCount = t->extraFileLength;
                } else {
-                       pt->t.byteCount = 0;
+                       ptt->byteCount = 0;
                }
        }
 
-       yaffs_DumpPackedTags2(pt);
+       yaffs_DumpPackedTags2TagsPart(ptt);
        yaffs_DumpTags2(t);
+}
+
+
+void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
+{
+       yaffs_PackTags2TagsPart(&pt->t,t);
 
 #ifndef YAFFS_IGNORE_TAGS_ECC
        {
@@ -103,68 +111,98 @@ void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
 #endif
 }
 
-void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
+
+void yaffs_UnpackTags2TagsPart(yaffs_ExtendedTags * t, yaffs_PackedTags2TagsPart * ptt)
 {
 
        memset(t, 0, sizeof(yaffs_ExtendedTags));
 
        yaffs_InitialiseTags(t);
 
-       if (pt->t.sequenceNumber != 0xFFFFFFFF) {
-               /* Page is in use */
-#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
+       if (ptt->sequenceNumber != 0xFFFFFFFF) {
                t->blockBad = 0;
                t->chunkUsed = 1;
-               t->objectId = pt->t.objectId;
-               t->chunkId = pt->t.chunkId;
-               t->byteCount = pt->t.byteCount;
+               t->objectId = ptt->objectId;
+               t->chunkId = ptt->chunkId;
+               t->byteCount = ptt->byteCount;
                t->chunkDeleted = 0;
                t->serialNumber = 0;
-               t->sequenceNumber = pt->t.sequenceNumber;
+               t->sequenceNumber = ptt->sequenceNumber;
 
                /* Do extra header info stuff */
 
-               if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
+               if (ptt->chunkId & EXTRA_HEADER_INFO_FLAG) {
                        t->chunkId = 0;
                        t->byteCount = 0;
 
                        t->extraHeaderInfoAvailable = 1;
                        t->extraParentObjectId =
-                           pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
+                           ptt->chunkId & (~(ALL_EXTRA_FLAGS));
                        t->extraIsShrinkHeader =
-                           (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                           (ptt->chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
                        t->extraShadows =
-                           (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+                           (ptt->chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
                        t->extraObjectType =
-                           pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
+                           ptt->objectId >> EXTRA_OBJECT_TYPE_SHIFT;
                        t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
 
                        if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
-                               t->extraEquivalentObjectId = pt->t.byteCount;
+                               t->extraEquivalentObjectId = ptt->byteCount;
                        } else {
-                               t->extraFileLength = pt->t.byteCount;
+                               t->extraFileLength = ptt->byteCount;
+                       }
+               }
+       }
+
+       yaffs_DumpPackedTags2TagsPart(ptt);
+       yaffs_DumpTags2(t);
+
+}
+
+
+void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
+{
+
+       yaffs_ECCResult eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+       
+       if (pt->t.sequenceNumber != 0xFFFFFFFF) {
+               /* Page is in use */
+#ifndef YAFFS_IGNORE_TAGS_ECC
+               {
+                       yaffs_ECCOther ecc;
+                       int result;
+                       yaffs_ECCCalculateOther((unsigned char *)&pt->t,
+                                               sizeof
+                                               (yaffs_PackedTags2TagsPart),
+                                               &ecc);
+                       result =
+                           yaffs_ECCCorrectOther((unsigned char *)&pt->t,
+                                                 sizeof
+                                                 (yaffs_PackedTags2TagsPart),
+                                                 &pt->ecc, &ecc);
+                       switch(result){
+                               case 0:
+                                       eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+                                       break;
+                               case 1:
+                                       eccResult = YAFFS_ECC_RESULT_FIXED;
+                                       break;
+                               case -1:
+                                       eccResult = YAFFS_ECC_RESULT_UNFIXED;
+                                       break;
+                               default:
+                                       eccResult = YAFFS_ECC_RESULT_UNKNOWN;
                        }
                }
+#endif
        }
 
+       yaffs_UnpackTags2TagsPart(t,&pt->t);
+       
+       t->eccResult = eccResult;
+
        yaffs_DumpPackedTags2(pt);
        yaffs_DumpTags2(t);
 
 }
+