2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
3 * yaffs_guts.h: Configuration etc for yaffs_guts
5 * Copyright (C) 2002 Aleph One Ltd.
6 * for Toby Churchill Ltd and Brightstar Engineering
8 * Created by Charles Manning <charles@aleph1.co.uk>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
16 #ifndef __YAFFS_GUTS_H__
17 #define __YAFFS_GUTS_H__
19 #include "devextras.h"
25 // Y=0x59, A=0x41, S=0x53
26 #define YAFFS_MAGIC 0x5941FF53
28 #define YAFFS_NTNODES_LEVEL0 16
29 #define YAFFS_TNODES_LEVEL0_BITS 4
30 #define YAFFS_TNODES_LEVEL0_MASK 0xf
32 #define YAFFS_NTNODES_INTERNAL (YAFFS_NTNODES_LEVEL0 / 2)
33 #define YAFFS_TNODES_INTERNAL_BITS (YAFFS_TNODES_LEVEL0_BITS - 1)
34 #define YAFFS_TNODES_INTERNAL_MASK 0x7
35 #define YAFFS_TNODES_MAX_LEVEL 6
37 #define YAFFS_BYTES_PER_CHUNK 512
38 #define YAFFS_CHUNK_SIZE_SHIFT 9
40 #define YAFFS_BYTES_PER_SPARE 16
42 #define YAFFS_CHUNKS_PER_BLOCK 32
43 #define YAFFS_BYTES_PER_BLOCK (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
45 #define YAFFS_MAX_CHUNK_ID 0x000FFFFF
47 #define YAFFS_UNUSED_OBJECT_ID 0x0003FFFF
49 #define YAFFS_ALLOCATION_NOBJECTS 100
50 #define YAFFS_ALLOCATION_NTNODES 100
51 #define YAFFS_ALLOCATION_NLINKS 100
53 #define YAFFS_NOBJECT_BUCKETS 256
56 #define YAFFS_RESERVED_BLOCKS 5
58 #define YAFFS_OBJECT_SPACE 0x40000
59 #define YAFFS_MAX_NAME_LENGTH 255
61 #define YAFFS_MAX_ALIAS_LENGTH 211
63 #define YAFFS_OBJECTID_ROOT 1
64 #define YAFFS_ROOT_MODE 0666
65 #define YAFFS_OBJECTID_LOSTNFOUND 2
66 #define YAFFS_LOSTNFOUND_NAME "lost+found"
68 // Tags structures in RAM
69 // NB This uses bitfield. Bitfields should not stradle a u32 boundary otherwise
70 // the structure size will get blown out.
75 unsigned serialNumber:2;
76 unsigned byteCount:10;
79 unsigned unusedStuff:2;
96 __u8 pageStatus; // Currently unused, but sort of set aside to distinguish
97 // unused - vs- used -vs- deleted chunks. We achieve this by
98 // using the objectId tags.
111 YAFFS_BLOCK_STATE_UddNKNOWN = 0,
112 YAFFS_BLOCK_STATE_SCANNING, // Used while the block is being scanned.
113 // NB Don't erase blocks while they're being scanned
115 YAFFS_BLOCK_STATE_EMPTY, // This block is empty
117 YAFFS_BLOCK_STATE_ALLOCATING, // This block is partially allocated.
118 // This is the one currently being used for page
119 // allocation. Should never be more than one of these
122 YAFFS_BLOCK_STATE_FULL, // All the pages in this block have been allocated.
123 // At least one page holds valid data.
125 YAFFS_BLOCK_STATE_DIRTY, // All pages have been allocated and deleted.
126 // Erase me, reuse me.
128 YAFFS_BLOCK_STATE_DEAD = 0x99 // This block has failed and is not in use
137 __u32 pageBits; // bitmap of pages in use
138 __u8 blockState; // One of the above block states
139 __u8 pagesInUse; // number of pages in use
143 //////////////////// Object structure ///////////////////////////
144 // This is the object structure as stored on NAND
148 YAFFS_OBJECT_TYPE_UNKNOWN,
149 YAFFS_OBJECT_TYPE_FILE,
150 YAFFS_OBJECT_TYPE_SYMLINK,
151 YAFFS_OBJECT_TYPE_DIRECTORY,
152 YAFFS_OBJECT_TYPE_HARDLINK
157 yaffs_ObjectType type;
159 // Apply to everything
161 __u16 sum; // checksum of name
162 char name[YAFFS_MAX_NAME_LENGTH + 1];
164 // Thes following apply to directories, files, symlinks - not hard links
165 __u32 st_mode; // protection
166 __u32 st_uid; // user ID of owner
167 __u32 st_gid; // group ID of owner
168 __u32 st_atime; // time of last access
169 __u32 st_mtime; // time of last modification
170 __u32 st_ctime; // time of last change
172 // File size applies to files only
175 // Equivalent object id applies to hard links only.
176 int equivalentObjectId;
177 char alias[YAFFS_MAX_ALIAS_LENGTH + 1];
180 } yaffs_ObjectHeader;
184 //////////////////// Tnode ///////////////////////////
186 union yaffs_Tnode_union
188 union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
189 __u16 level0[YAFFS_NTNODES_LEVEL0];
193 typedef union yaffs_Tnode_union yaffs_Tnode;
195 struct yaffs_TnodeList_struct
197 struct yaffs_TnodeList_struct *next;
201 typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
205 /////////////////// Object ////////////////////////////////
206 // An object can be one of:
207 // - a directory (no data, has children links
208 // - a regular file (data.... not prunes :->).
209 // - a symlink [symbolic link] (the alias).
218 } yaffs_FileStructure;
222 struct list_head children; // list of child links
223 } yaffs_DirectoryStructure;
228 } yaffs_SymLinkStructure;
232 struct yaffs_ObjectStruct *equivalentObject;
233 __u32 equivalentObjectId;
234 } yaffs_HardLinkStructure;
238 yaffs_FileStructure fileVariant;
239 yaffs_DirectoryStructure directoryVariant;
240 yaffs_SymLinkStructure symLinkVariant;
241 yaffs_HardLinkStructure hardLinkVariant;
242 } yaffs_ObjectVariant;
245 struct yaffs_ObjectStruct
247 __u8 fake:1; // A fake object has no presence on NAND.
248 __u8 renameAllowed:1;
249 __u8 unlinkAllowed:1;
250 __u8 dirty:1; // the object needs to be written to flash
251 __u8 valid:1; // When the file system is being loaded up, this
252 // object might be created before the data
253 // is available (ie. file data records appear before the header).
254 __u8 serial; // serial number of chunk in NAND. Store here so we don't have to
255 // read back the old one to update.
256 __u16 sum; // sum of the name to speed searching
258 struct yaffs_DeviceStruct *myDev; // The device I'm on
261 struct list_head hashLink; // list of objects in this hash bucket
264 struct list_head hardLinks; // all the equivalent hard linked objects
266 // directory structure stuff
267 struct yaffs_ObjectStruct *parent; //my parent directory
268 struct list_head siblings; // siblings in a directory
269 // also used for linking up the free list
271 // Where's my data in NAND?
272 int chunkId; // where it lives
274 __u32 objectId; // the object id value
277 __u32 st_mode; // protection
278 __u32 st_uid; // user ID of owner
279 __u32 st_gid; // group ID of owner
280 __u32 st_atime; // time of last access
281 __u32 st_mtime; // time of last modification
282 __u32 st_ctime; // time of last change
285 yaffs_ObjectType variantType;
287 yaffs_ObjectVariant variant;
293 typedef struct yaffs_ObjectStruct yaffs_Object;
296 struct yaffs_ObjectList_struct
298 yaffs_Object *objects;
299 struct yaffs_ObjectList_struct *next;
302 typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
306 struct list_head list;
308 } yaffs_ObjectBucket;
311 //////////////////// Device ////////////////////////////////
313 struct yaffs_DeviceStruct
315 // Entry parameters set up way early. Yaffs sets up the rest.
316 __u32 nBlocks; // Size of whole device in blocks
317 __u32 startBlock; // Start block we're allowed to use
318 __u32 endBlock; // End block we're allowed to use
319 __u16 chunkGroupBits; // 0 for devices <= 32MB. else log2(nchunks) - 16
320 __u16 chunkGroupSize; // == 2^^chunkGroupBits
323 void *genericDevice; // Pointer to device context
324 // On an mtd this holds the mtd pointer.
328 struct semaphore sem;// Semaphore for waiting on erasure.
333 // NAND access functions (Must be set before calling YAFFS)
335 int (*writeChunkToNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
336 int (*readChunkFromNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
337 int (*eraseBlockInNAND)(struct yaffs_DeviceStruct *dev,int blockInNAND);
338 int (*initialiseNAND)(struct yaffs_DeviceStruct *dev);
341 void (*putSuperFunc)(struct super_block *sb);
344 // Runtime parameters.
345 yaffs_BlockInfo *blockInfo;
348 __u32 allocationPage;
352 yaffs_Tnode *freeTnodes;
354 yaffs_TnodeList *allocatedTnodeList;
358 yaffs_Object *freeObjects;
361 yaffs_ObjectList *allocatedObjectList;
363 yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
367 int currentDirtyChecker; // Used to find current dirtiest block
369 int garbageCollectionRequired;
371 yaffs_Object *rootDir;
372 yaffs_Object *lostNFoundDir;
377 typedef struct yaffs_DeviceStruct yaffs_Device;
381 //////////// YAFFS Functions //////////////////
383 int yaffs_GutsInitialise(yaffs_Device *dev);
384 void yaffs_Deinitialise(yaffs_Device *dev);
386 int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev);
390 int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName);
392 // generic Object functions
393 int yaffs_Unlink(yaffs_Object *dir, const char *name);
395 // Object access functions.
396 int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize);
397 int yaffs_GetObjectFileLength(yaffs_Object *obj);
398 int yaffs_GetObjectInode(yaffs_Object *obj);
399 unsigned yaffs_GetObjectType(yaffs_Object *obj);
400 int yaffs_GetObjectLinkCount(yaffs_Object *obj);
402 // Change inode attributes
403 int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr);
404 int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr);
407 int yaffs_ReadDataFromFile(yaffs_Object *obj, __u8 *buffer, __u32 offset, int nBytes);
408 int yaffs_WriteDataToFile(yaffs_Object *obj, const __u8 *buffer, __u32 offset, int nBytes);
409 int yaffs_ResizeFile(yaffs_Object *obj, int newSize);
411 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
412 int yaffs_FlushFile(yaffs_Object *obj);
415 // Directory operations
416 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
417 yaffs_Object *yaffs_FindObjectByName(yaffs_Object *theDir,const char *name);
418 int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *));
420 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number);
423 yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject);
425 yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj);
427 // Symlink operations
428 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const char *name, __u32 mode, __u32 uid, __u32 gid, const char *alias);
429 char *yaffs_GetSymlinkAlias(yaffs_Object *obj);
432 // Special directories
433 yaffs_Object *yaffs_Root(yaffs_Device *dev);
434 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev);
438 int yaffs_DumpObject(yaffs_Object *obj);
441 void yaffs_GutsTest(yaffs_Device *dev);