2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
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3 * yaffs_guts.h: Configuration etc for yaffs_guts
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5 * Copyright (C) 2002 Aleph One Ltd.
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6 * for Toby Churchill Ltd and Brightstar Engineering
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8 * Created by Charles Manning <charles@aleph1.co.uk>
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10 * This program is free software; you can redistribute it and/or modify
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11 * it under the terms of the GNU General Public License version 2 as
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12 * published by the Free Software Foundation.
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16 #ifndef __YAFFS_GUTS_H__
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17 #define __YAFFS_GUTS_H__
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19 #include "devextras.h"
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23 #define YAFFS_FAIL 0
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25 // Y=0x59, A=0x41, S=0x53
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26 #define YAFFS_MAGIC 0x5941FF53
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28 #define YAFFS_NTNODES_LEVEL0 16
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29 #define YAFFS_TNODES_LEVEL0_BITS 4
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30 #define YAFFS_TNODES_LEVEL0_MASK 0xf
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32 #define YAFFS_NTNODES_INTERNAL (YAFFS_NTNODES_LEVEL0 / 2)
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33 #define YAFFS_TNODES_INTERNAL_BITS (YAFFS_TNODES_LEVEL0_BITS - 1)
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34 #define YAFFS_TNODES_INTERNAL_MASK 0x7
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35 #define YAFFS_TNODES_MAX_LEVEL 6
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37 #define YAFFS_BYTES_PER_CHUNK 512
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38 #define YAFFS_CHUNK_SIZE_SHIFT 9
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40 #define YAFFS_BYTES_PER_SPARE 16
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42 #define YAFFS_CHUNKS_PER_BLOCK 32
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43 #define YAFFS_BYTES_PER_BLOCK (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
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45 #define YAFFS_MAX_CHUNK_ID 0x000FFFFF
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47 #define YAFFS_UNUSED_OBJECT_ID 0x0003FFFF
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49 #define YAFFS_ALLOCATION_NOBJECTS 100
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50 #define YAFFS_ALLOCATION_NTNODES 100
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51 #define YAFFS_ALLOCATION_NLINKS 100
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53 #define YAFFS_NOBJECT_BUCKETS 256
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56 #define YAFFS_RESERVED_BLOCKS 5
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58 #define YAFFS_OBJECT_SPACE 0x40000
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59 #define YAFFS_MAX_NAME_LENGTH 255
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61 #define YAFFS_MAX_ALIAS_LENGTH 159
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63 #define YAFFS_OBJECTID_ROOT 1
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64 #define YAFFS_OBJECTID_LOSTNFOUND 2
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66 // Tags structures in RAM
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67 // NB This uses bitfield. Bitfields should not stradle a u32 boundary otherwise
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68 // the structure size will get blown out.
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72 unsigned chunkId:20;
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73 unsigned serialNumber:2;
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74 unsigned byteCount:10;
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75 unsigned objectId:18;
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77 unsigned unusedStuff:2;
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94 __u8 pageStatus; // Currently unused, but sort of set aside to distinguish
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95 // unused - vs- used -vs- deleted chunks. We achieve this by
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96 // using the objectId tags.
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106 // Block data in RAM
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109 YAFFS_BLOCK_STATE_UddNKNOWN = 0,
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110 YAFFS_BLOCK_STATE_SCANNING, // Used while the block is being scanned.
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111 // NB Don't erase blocks while they're being scanned
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113 YAFFS_BLOCK_STATE_EMPTY, // This block is empty
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115 YAFFS_BLOCK_STATE_ALLOCATING, // This block is partially allocated.
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116 // This is the one currently being used for page
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117 // allocation. Should never be more than one of these
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120 YAFFS_BLOCK_STATE_FULL, // All the pages in this block have been allocated.
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121 // At least one page holds valid data.
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123 YAFFS_BLOCK_STATE_DIRTY, // All pages have been allocated and deleted.
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124 // Erase me, reuse me.
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126 YAFFS_BLOCK_STATE_DEAD = 0x77 // This block has failed and is not in use
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128 } yaffs_BlockState;
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135 __u32 pageBits; // bitmap of pages in use
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136 __u8 blockState; // One of the above block states
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137 __u8 pagesInUse; // number of pages in use
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138 __u8 needsRetiring:1; // Data has failed on this block, need to get valid data off
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139 // and retire the block.
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143 //////////////////// Object structure ///////////////////////////
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144 // This is the object structure as stored on NAND
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148 YAFFS_OBJECT_TYPE_UNKNOWN,
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149 YAFFS_OBJECT_TYPE_FILE,
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150 YAFFS_OBJECT_TYPE_SYMLINK,
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151 YAFFS_OBJECT_TYPE_DIRECTORY,
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152 YAFFS_OBJECT_TYPE_HARDLINK,
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153 YAFFS_OBJECT_TYPE_SPECIAL
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154 } yaffs_ObjectType;
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158 yaffs_ObjectType type;
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160 // Apply to everything
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161 int parentObjectId;
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162 __u16 sum; // checksum of name
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163 char name[YAFFS_MAX_NAME_LENGTH + 1];
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165 // Thes following apply to directories, files, symlinks - not hard links
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166 __u32 st_mode; // protection
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167 __u32 st_uid; // user ID of owner
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168 __u32 st_gid; // group ID of owner
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169 __u32 st_atime; // time of last access
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170 __u32 st_mtime; // time of last modification
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171 __u32 st_ctime; // time of last change
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173 // File size applies to files only
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176 // Equivalent object id applies to hard links only.
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177 int equivalentObjectId;
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179 // Alias is for symlinks only.
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180 char alias[YAFFS_MAX_ALIAS_LENGTH + 1];
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182 __u32 st_rdev; // device stuff for block and char devices (maj/min)
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183 // Roowm to grow...
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184 __u32 roomToGrow[12];
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186 } yaffs_ObjectHeader;
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190 //////////////////// Tnode ///////////////////////////
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192 union yaffs_Tnode_union
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194 union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
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195 __u16 level0[YAFFS_NTNODES_LEVEL0];
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199 typedef union yaffs_Tnode_union yaffs_Tnode;
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201 struct yaffs_TnodeList_struct
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203 struct yaffs_TnodeList_struct *next;
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204 yaffs_Tnode *tnodes;
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207 typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
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211 /////////////////// Object ////////////////////////////////
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212 // An object can be one of:
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213 // - a directory (no data, has children links
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214 // - a regular file (data.... not prunes :->).
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215 // - a symlink [symbolic link] (the alias).
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222 __u32 scannedFileSize;
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225 } yaffs_FileStructure;
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229 struct list_head children; // list of child links
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230 } yaffs_DirectoryStructure;
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235 } yaffs_SymLinkStructure;
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239 struct yaffs_ObjectStruct *equivalentObject;
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240 __u32 equivalentObjectId;
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241 } yaffs_HardLinkStructure;
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245 yaffs_FileStructure fileVariant;
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246 yaffs_DirectoryStructure directoryVariant;
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247 yaffs_SymLinkStructure symLinkVariant;
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248 yaffs_HardLinkStructure hardLinkVariant;
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249 } yaffs_ObjectVariant;
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252 struct yaffs_ObjectStruct
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254 __u8 fake:1; // A fake object has no presence on NAND.
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255 __u8 renameAllowed:1;
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256 __u8 unlinkAllowed:1;
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257 __u8 dirty:1; // the object needs to be written to flash
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258 __u8 valid:1; // When the file system is being loaded up, this
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259 // object might be created before the data
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260 // is available (ie. file data records appear before the header).
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261 __u8 serial; // serial number of chunk in NAND. Store here so we don't have to
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262 // read back the old one to update.
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263 __u16 sum; // sum of the name to speed searching
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265 struct yaffs_DeviceStruct *myDev; // The device I'm on
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268 struct list_head hashLink; // list of objects in this hash bucket
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271 struct list_head hardLinks; // all the equivalent hard linked objects
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272 // live on this list
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273 // directory structure stuff
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274 struct yaffs_ObjectStruct *parent; //my parent directory
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275 struct list_head siblings; // siblings in a directory
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276 // also used for linking up the free list
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278 // Where's my data in NAND?
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279 int chunkId; // where it lives
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281 int nDataChunks; // really only for debugging.
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283 __u32 objectId; // the object id value
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286 __u32 st_mode; // protection
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287 __u32 st_uid; // user ID of owner
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288 __u32 st_gid; // group ID of owner
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289 __u32 st_atime; // time of last access
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290 __u32 st_mtime; // time of last modification
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291 __u32 st_ctime; // time of last change
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292 __u32 st_rdev; // device stuff for block and char devices
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299 yaffs_ObjectType variantType;
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301 yaffs_ObjectVariant variant;
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307 typedef struct yaffs_ObjectStruct yaffs_Object;
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310 struct yaffs_ObjectList_struct
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312 yaffs_Object *objects;
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313 struct yaffs_ObjectList_struct *next;
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316 typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
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320 struct list_head list;
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322 } yaffs_ObjectBucket;
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325 //////////////////// Device ////////////////////////////////
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327 struct yaffs_DeviceStruct
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329 // Entry parameters set up way early. Yaffs sets up the rest.
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330 __u32 nBlocks; // Size of whole device in blocks
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331 __u32 startBlock; // Start block we're allowed to use
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332 __u32 endBlock; // End block we're allowed to use
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333 __u16 chunkGroupBits; // 0 for devices <= 32MB. else log2(nchunks) - 16
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334 __u16 chunkGroupSize; // == 2^^chunkGroupBits
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337 void *genericDevice; // Pointer to device context
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338 // On an mtd this holds the mtd pointer.
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342 struct semaphore sem;// Semaphore for waiting on erasure.
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347 // NAND access functions (Must be set before calling YAFFS)
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349 int (*writeChunkToNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
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350 int (*readChunkFromNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
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351 int (*eraseBlockInNAND)(struct yaffs_DeviceStruct *dev,int blockInNAND);
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352 int (*initialiseNAND)(struct yaffs_DeviceStruct *dev);
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355 void (*putSuperFunc)(struct super_block *sb);
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358 // Runtime parameters.
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359 yaffs_BlockInfo *blockInfo;
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361 int allocationBlock;
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362 __u32 allocationPage;
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365 int nTnodesCreated;
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366 yaffs_Tnode *freeTnodes;
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368 yaffs_TnodeList *allocatedTnodeList;
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371 int nObjectsCreated;
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372 yaffs_Object *freeObjects;
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375 yaffs_ObjectList *allocatedObjectList;
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377 yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
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381 int currentDirtyChecker; // Used to find current dirtiest block
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383 int garbageCollectionRequired;
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385 // Operations since mount
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388 int nBlockErasures;
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390 int nRetriedWrites;
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391 int nRetiredBlocks;
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393 yaffs_Object *rootDir;
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394 yaffs_Object *lostNFoundDir;
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396 // Buffer areas for storing data to recover from write failures
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397 __u8 bufferedData[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
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398 yaffs_Spare bufferedSpare[YAFFS_CHUNKS_PER_BLOCK];
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399 int bufferedBlock; // Which block is buffered here?
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400 int doingBufferedBlockRewrite;
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402 int blockSelectedForGC;
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407 typedef struct yaffs_DeviceStruct yaffs_Device;
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411 //////////// YAFFS Functions //////////////////
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413 int yaffs_GutsInitialise(yaffs_Device *dev);
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414 void yaffs_Deinitialise(yaffs_Device *dev);
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416 int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev);
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420 int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName);
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422 // generic Object functions
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423 int yaffs_Unlink(yaffs_Object *dir, const char *name);
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425 // Object access functions.
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426 int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize);
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427 int yaffs_GetObjectFileLength(yaffs_Object *obj);
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428 int yaffs_GetObjectInode(yaffs_Object *obj);
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429 unsigned yaffs_GetObjectType(yaffs_Object *obj);
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430 int yaffs_GetObjectLinkCount(yaffs_Object *obj);
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432 // Change inode attributes
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433 int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr);
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434 int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr);
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437 int yaffs_ReadDataFromFile(yaffs_Object *obj, __u8 *buffer, __u32 offset, int nBytes);
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438 int yaffs_WriteDataToFile(yaffs_Object *obj, const __u8 *buffer, __u32 offset, int nBytes);
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439 int yaffs_ResizeFile(yaffs_Object *obj, int newSize);
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441 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
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442 int yaffs_FlushFile(yaffs_Object *obj);
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445 // Directory operations
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446 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
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447 yaffs_Object *yaffs_FindObjectByName(yaffs_Object *theDir,const char *name);
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448 int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *));
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450 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number);
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453 yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject);
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455 yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj);
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457 // Symlink operations
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458 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const char *name, __u32 mode, __u32 uid, __u32 gid, const char *alias);
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459 char *yaffs_GetSymlinkAlias(yaffs_Object *obj);
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461 // Special inodes (fifos, sockets and devices)
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462 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid,__u32 rdev);
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465 // Special directories
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466 yaffs_Object *yaffs_Root(yaffs_Device *dev);
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467 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev);
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471 int yaffs_DumpObject(yaffs_Object *obj);
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474 void yaffs_GutsTest(yaffs_Device *dev);
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