| 1 | /* |
| 2 | * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. |
| 3 | * |
| 4 | * Copyright (C) 2002-2010 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_trace.h" |
| 17 | #include "yaffs_tagsvalidity.h" |
| 18 | |
| 19 | /* This code packs a set of extended tags into a binary structure for |
| 20 | * NAND storage |
| 21 | */ |
| 22 | |
| 23 | /* Some of the information is "extra" struff which can be packed in to |
| 24 | * speed scanning |
| 25 | * This is defined by having the EXTRA_HEADER_INFO_FLAG set. |
| 26 | */ |
| 27 | |
| 28 | /* Extra flags applied to chunk_id */ |
| 29 | |
| 30 | #define EXTRA_HEADER_INFO_FLAG 0x80000000 |
| 31 | #define EXTRA_SHRINK_FLAG 0x40000000 |
| 32 | #define EXTRA_SHADOWS_FLAG 0x20000000 |
| 33 | #define EXTRA_SPARE_FLAGS 0x10000000 |
| 34 | |
| 35 | #define ALL_EXTRA_FLAGS 0xF0000000 |
| 36 | |
| 37 | /* Also, the top 4 bits of the object Id are set to the object type. */ |
| 38 | #define EXTRA_OBJECT_TYPE_SHIFT (28) |
| 39 | #define EXTRA_OBJECT_TYPE_MASK ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT) |
| 40 | |
| 41 | |
| 42 | static void yaffs_DumpPackedTags2TagsPart(const yaffs_PackedTags2TagsPart *ptt) |
| 43 | { |
| 44 | T(YAFFS_TRACE_MTD, |
| 45 | (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR), |
| 46 | ptt->obj_id, ptt->chunk_id, ptt->n_bytes, |
| 47 | ptt->seq_number)); |
| 48 | } |
| 49 | static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 *pt) |
| 50 | { |
| 51 | yaffs_DumpPackedTags2TagsPart(&pt->t); |
| 52 | } |
| 53 | |
| 54 | static void yaffs_DumpTags2(const yaffs_ext_tags *t) |
| 55 | { |
| 56 | T(YAFFS_TRACE_MTD, |
| 57 | (TSTR |
| 58 | ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d" |
| 59 | TENDSTR), t->ecc_result, t->block_bad, t->chunk_used, t->obj_id, |
| 60 | t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number, |
| 61 | t->seq_number)); |
| 62 | |
| 63 | } |
| 64 | |
| 65 | void yaffs_PackTags2TagsPart(yaffs_PackedTags2TagsPart *ptt, |
| 66 | const yaffs_ext_tags *t) |
| 67 | { |
| 68 | ptt->chunk_id = t->chunk_id; |
| 69 | ptt->seq_number = t->seq_number; |
| 70 | ptt->n_bytes = t->n_bytes; |
| 71 | ptt->obj_id = t->obj_id; |
| 72 | |
| 73 | if (t->chunk_id == 0 && t->extra_available) { |
| 74 | /* Store the extra header info instead */ |
| 75 | /* We save the parent object in the chunk_id */ |
| 76 | ptt->chunk_id = EXTRA_HEADER_INFO_FLAG |
| 77 | | t->extra_parent_id; |
| 78 | if (t->extra_is_shrink) |
| 79 | ptt->chunk_id |= EXTRA_SHRINK_FLAG; |
| 80 | if (t->extra_shadows) |
| 81 | ptt->chunk_id |= EXTRA_SHADOWS_FLAG; |
| 82 | |
| 83 | ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK; |
| 84 | ptt->obj_id |= |
| 85 | (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT); |
| 86 | |
| 87 | if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK) |
| 88 | ptt->n_bytes = t->extra_equiv_id; |
| 89 | else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE) |
| 90 | ptt->n_bytes = t->extra_length; |
| 91 | else |
| 92 | ptt->n_bytes = 0; |
| 93 | } |
| 94 | |
| 95 | yaffs_DumpPackedTags2TagsPart(ptt); |
| 96 | yaffs_DumpTags2(t); |
| 97 | } |
| 98 | |
| 99 | |
| 100 | void yaffs_PackTags2(yaffs_PackedTags2 *pt, const yaffs_ext_tags *t, int tagsECC) |
| 101 | { |
| 102 | yaffs_PackTags2TagsPart(&pt->t, t); |
| 103 | |
| 104 | if(tagsECC) |
| 105 | yaffs_ecc_calc_other((unsigned char *)&pt->t, |
| 106 | sizeof(yaffs_PackedTags2TagsPart), |
| 107 | &pt->ecc); |
| 108 | } |
| 109 | |
| 110 | |
| 111 | void yaffs_unpack_tags2tags_part(yaffs_ext_tags *t, |
| 112 | yaffs_PackedTags2TagsPart *ptt) |
| 113 | { |
| 114 | |
| 115 | memset(t, 0, sizeof(yaffs_ext_tags)); |
| 116 | |
| 117 | yaffs_init_tags(t); |
| 118 | |
| 119 | if (ptt->seq_number != 0xFFFFFFFF) { |
| 120 | t->block_bad = 0; |
| 121 | t->chunk_used = 1; |
| 122 | t->obj_id = ptt->obj_id; |
| 123 | t->chunk_id = ptt->chunk_id; |
| 124 | t->n_bytes = ptt->n_bytes; |
| 125 | t->is_deleted = 0; |
| 126 | t->serial_number = 0; |
| 127 | t->seq_number = ptt->seq_number; |
| 128 | |
| 129 | /* Do extra header info stuff */ |
| 130 | |
| 131 | if (ptt->chunk_id & EXTRA_HEADER_INFO_FLAG) { |
| 132 | t->chunk_id = 0; |
| 133 | t->n_bytes = 0; |
| 134 | |
| 135 | t->extra_available = 1; |
| 136 | t->extra_parent_id = |
| 137 | ptt->chunk_id & (~(ALL_EXTRA_FLAGS)); |
| 138 | t->extra_is_shrink = |
| 139 | (ptt->chunk_id & EXTRA_SHRINK_FLAG) ? 1 : 0; |
| 140 | t->extra_shadows = |
| 141 | (ptt->chunk_id & EXTRA_SHADOWS_FLAG) ? 1 : 0; |
| 142 | t->extra_obj_type = |
| 143 | ptt->obj_id >> EXTRA_OBJECT_TYPE_SHIFT; |
| 144 | t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK; |
| 145 | |
| 146 | if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK) |
| 147 | t->extra_equiv_id = ptt->n_bytes; |
| 148 | else |
| 149 | t->extra_length = ptt->n_bytes; |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | yaffs_DumpPackedTags2TagsPart(ptt); |
| 154 | yaffs_DumpTags2(t); |
| 155 | |
| 156 | } |
| 157 | |
| 158 | |
| 159 | void yaffs_unpack_tags2(yaffs_ext_tags *t, yaffs_PackedTags2 *pt, int tagsECC) |
| 160 | { |
| 161 | |
| 162 | yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR; |
| 163 | |
| 164 | if (pt->t.seq_number != 0xFFFFFFFF && |
| 165 | tagsECC){ |
| 166 | /* Chunk is in use and we need to do ECC */ |
| 167 | |
| 168 | yaffs_ECCOther ecc; |
| 169 | int result; |
| 170 | yaffs_ecc_calc_other((unsigned char *)&pt->t, |
| 171 | sizeof(yaffs_PackedTags2TagsPart), |
| 172 | &ecc); |
| 173 | result = yaffs_ecc_correct_other((unsigned char *)&pt->t, |
| 174 | sizeof(yaffs_PackedTags2TagsPart), |
| 175 | &pt->ecc, &ecc); |
| 176 | switch (result) { |
| 177 | case 0: |
| 178 | ecc_result = YAFFS_ECC_RESULT_NO_ERROR; |
| 179 | break; |
| 180 | case 1: |
| 181 | ecc_result = YAFFS_ECC_RESULT_FIXED; |
| 182 | break; |
| 183 | case -1: |
| 184 | ecc_result = YAFFS_ECC_RESULT_UNFIXED; |
| 185 | break; |
| 186 | default: |
| 187 | ecc_result = YAFFS_ECC_RESULT_UNKNOWN; |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | yaffs_unpack_tags2tags_part(t, &pt->t); |
| 192 | |
| 193 | t->ecc_result = ecc_result; |
| 194 | |
| 195 | yaffs_DumpPackedTags2(pt); |
| 196 | yaffs_DumpTags2(t); |
| 197 | } |
| 198 | |
| 199 | |
