diff options
Diffstat (limited to 'fs/yaffs2/yaffs_packedtags2.c')
| -rw-r--r-- | fs/yaffs2/yaffs_packedtags2.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_packedtags2.c b/fs/yaffs2/yaffs_packedtags2.c new file mode 100644 index 000000000000..f8ae94ccddb4 --- /dev/null +++ b/fs/yaffs2/yaffs_packedtags2.c @@ -0,0 +1,198 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2010 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_trace.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) + + +static void yaffs_DumpPackedTags2TagsPart(const yaffs_PackedTags2TagsPart *ptt) +{ + 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); +} + +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_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; + } + + yaffs_DumpPackedTags2TagsPart(ptt); + yaffs_DumpTags2(t); +} + + +void yaffs_PackTags2(yaffs_PackedTags2 *pt, const yaffs_ExtendedTags *t, int tagsECC) +{ + yaffs_PackTags2TagsPart(&pt->t, t); + + if(tagsECC) + yaffs_ECCCalculateOther((unsigned char *)&pt->t, + sizeof(yaffs_PackedTags2TagsPart), + &pt->ecc); +} + + +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 = ptt->objectId; + t->chunkId = ptt->chunkId; + t->byteCount = ptt->byteCount; + t->chunkDeleted = 0; + t->serialNumber = 0; + 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, int tagsECC) +{ + + yaffs_ECCResult eccResult = YAFFS_ECC_RESULT_NO_ERROR; + + if (pt->t.sequenceNumber != 0xFFFFFFFF && + tagsECC){ + /* Chunk is in use and we need to do 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; + } + } + + yaffs_UnpackTags2TagsPart(t, &pt->t); + + t->eccResult = eccResult; + + yaffs_DumpPackedTags2(pt); + yaffs_DumpTags2(t); +} + |