[8.09] [kernel] generic-2.6: rename "files" directory to "files-2.6.24" to be consistent
[openwrt/svn-archive/archive.git] / target / linux / generic-2.6 / files-2.6.24 / fs / yaffs2 / yaffs_packedtags2.c
1 /*
2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3 *
4 * Copyright (C) 2002-2007 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include "yaffs_packedtags2.h"
15 #include "yportenv.h"
16 #include "yaffs_tagsvalidity.h"
17
18 /* This code packs a set of extended tags into a binary structure for
19 * NAND storage
20 */
21
22 /* Some of the information is "extra" struff which can be packed in to
23 * speed scanning
24 * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
25 */
26
27 /* Extra flags applied to chunkId */
28
29 #define EXTRA_HEADER_INFO_FLAG 0x80000000
30 #define EXTRA_SHRINK_FLAG 0x40000000
31 #define EXTRA_SHADOWS_FLAG 0x20000000
32 #define EXTRA_SPARE_FLAGS 0x10000000
33
34 #define ALL_EXTRA_FLAGS 0xF0000000
35
36 /* Also, the top 4 bits of the object Id are set to the object type. */
37 #define EXTRA_OBJECT_TYPE_SHIFT (28)
38 #define EXTRA_OBJECT_TYPE_MASK ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
39
40 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
41 {
42 T(YAFFS_TRACE_MTD,
43 (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
44 pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
45 pt->t.sequenceNumber));
46 }
47
48 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
49 {
50 T(YAFFS_TRACE_MTD,
51 (TSTR
52 ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
53 "%d del %d ser %d seq %d"
54 TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
55 t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
56 t->sequenceNumber));
57
58 }
59
60 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
61 {
62 pt->t.chunkId = t->chunkId;
63 pt->t.sequenceNumber = t->sequenceNumber;
64 pt->t.byteCount = t->byteCount;
65 pt->t.objectId = t->objectId;
66
67 if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
68 /* Store the extra header info instead */
69 /* We save the parent object in the chunkId */
70 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
71 | t->extraParentObjectId;
72 if (t->extraIsShrinkHeader) {
73 pt->t.chunkId |= EXTRA_SHRINK_FLAG;
74 }
75 if (t->extraShadows) {
76 pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
77 }
78
79 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
80 pt->t.objectId |=
81 (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
82
83 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
84 pt->t.byteCount = t->extraEquivalentObjectId;
85 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
86 pt->t.byteCount = t->extraFileLength;
87 } else {
88 pt->t.byteCount = 0;
89 }
90 }
91
92 yaffs_DumpPackedTags2(pt);
93 yaffs_DumpTags2(t);
94
95 #ifndef YAFFS_IGNORE_TAGS_ECC
96 {
97 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
98 sizeof(yaffs_PackedTags2TagsPart),
99 &pt->ecc);
100 }
101 #endif
102 }
103
104 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
105 {
106
107 memset(t, 0, sizeof(yaffs_ExtendedTags));
108
109 yaffs_InitialiseTags(t);
110
111 if (pt->t.sequenceNumber != 0xFFFFFFFF) {
112 /* Page is in use */
113 #ifdef YAFFS_IGNORE_TAGS_ECC
114 {
115 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
116 }
117 #else
118 {
119 yaffs_ECCOther ecc;
120 int result;
121 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
122 sizeof
123 (yaffs_PackedTags2TagsPart),
124 &ecc);
125 result =
126 yaffs_ECCCorrectOther((unsigned char *)&pt->t,
127 sizeof
128 (yaffs_PackedTags2TagsPart),
129 &pt->ecc, &ecc);
130 switch(result){
131 case 0:
132 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
133 break;
134 case 1:
135 t->eccResult = YAFFS_ECC_RESULT_FIXED;
136 break;
137 case -1:
138 t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
139 break;
140 default:
141 t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
142 }
143 }
144 #endif
145 t->blockBad = 0;
146 t->chunkUsed = 1;
147 t->objectId = pt->t.objectId;
148 t->chunkId = pt->t.chunkId;
149 t->byteCount = pt->t.byteCount;
150 t->chunkDeleted = 0;
151 t->serialNumber = 0;
152 t->sequenceNumber = pt->t.sequenceNumber;
153
154 /* Do extra header info stuff */
155
156 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
157 t->chunkId = 0;
158 t->byteCount = 0;
159
160 t->extraHeaderInfoAvailable = 1;
161 t->extraParentObjectId =
162 pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
163 t->extraIsShrinkHeader =
164 (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
165 t->extraShadows =
166 (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
167 t->extraObjectType =
168 pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
169 t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
170
171 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
172 t->extraEquivalentObjectId = pt->t.byteCount;
173 } else {
174 t->extraFileLength = pt->t.byteCount;
175 }
176 }
177 }
178
179 yaffs_DumpPackedTags2(pt);
180 yaffs_DumpTags2(t);
181
182 }