More formatting
[yaffs2.git] / yaffs_packedtags2.c
index f734882..a78c03c 100644 (file)
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * 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 General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
 #include "yaffs_packedtags2.h"
 #include "yportenv.h"
+#include "yaffs_tagsvalidity.h"
+
+/* 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_SHADOWS_FLAG     0x20000000
+#define EXTRA_SPARE_FLAGS      0x10000000
+
+#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)
 
 
-void yaffs_PackTags2(yaffs_PackedTags2 *pt, yaffs_ExtendedTags *t)
+static void yaffs_DumpPackedTags2TagsPart(const yaffs_PackedTags2TagsPart *ptt)
 {
-       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);
-       
+       T(YAFFS_TRACE_MTD,
+         (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
+          ptt->objectId, ptt->chunkId, ptt->byteCount,
+          ptt->sequenceNumber));
+}
+static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 *pt)
+{
+       yaffs_DumpPackedTags2TagsPart(&pt->t);
 }
 
-void yaffs_UnpackTags2(yaffs_ExtendedTags *t, yaffs_PackedTags2 *pt)
+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));
 
-       
-       if(pt->t.sequenceNumber == 0xFFFFFFFF)
-       {
-               memset(t,0,sizeof(yaffs_ExtendedTags));
-               
+}
+
+void yaffs_PackTags2TagsPart(yaffs_PackedTags2TagsPart *ptt,
+               const yaffs_ExtendedTags *t)
+{
+       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 */
+               ptt->chunkId = EXTRA_HEADER_INFO_FLAG
+                       | t->extraParentObjectId;
+               if (t->extraIsShrinkHeader)
+                       ptt->chunkId |= EXTRA_SHRINK_FLAG;
+               if (t->extraShadows)
+                       ptt->chunkId |= EXTRA_SHADOWS_FLAG;
+
+               ptt->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+               ptt->objectId |=
+                   (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
+
+               if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK)
+                       ptt->byteCount = t->extraEquivalentObjectId;
+               else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE)
+                       ptt->byteCount = t->extraFileLength;
+               else
+                       ptt->byteCount = 0;
        }
-       else
+
+       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
        {
-               // 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);
+               yaffs_ECCCalculateOther((unsigned char *)&pt->t,
+                                       sizeof(yaffs_PackedTags2TagsPart),
+                                       &pt->ecc);
+       }
+#endif
+}
+
+
+void yaffs_UnpackTags2TagsPart(yaffs_ExtendedTags *t,
+               yaffs_PackedTags2TagsPart *ptt)
+{
+
+       memset(t, 0, sizeof(yaffs_ExtendedTags));
+
+       yaffs_InitialiseTags(t);
+
+       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 (ptt->chunkId & EXTRA_HEADER_INFO_FLAG) {
+                       t->chunkId = 0;
+                       t->byteCount = 0;
+
+                       t->extraHeaderInfoAvailable = 1;
+                       t->extraParentObjectId =
+                           ptt->chunkId & (~(ALL_EXTRA_FLAGS));
+                       t->extraIsShrinkHeader =
+                           (ptt->chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                       t->extraShadows =
+                           (ptt->chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+                       t->extraObjectType =
+                           ptt->objectId >> EXTRA_OBJECT_TYPE_SHIFT;
+                       t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+
+                       if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK)
+                               t->extraEquivalentObjectId = ptt->byteCount;
+                       else
+                               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);
+
 }