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 Lesser General Public License version 2.1 as
12 * published by the Free Software Foundation.
16 #ifndef __YAFFS_GUTS_H__
17 #define __YAFFS_GUTS_H__
19 #include "devextras.h"
29 // And what have we got...
30 #define YAFFS_MAGIC 0x5941FF53
32 #define YAFFS_NTNODES_LEVEL0 16
33 #define YAFFS_TNODES_LEVEL0_BITS 4
34 #define YAFFS_TNODES_LEVEL0_MASK 0xf
36 #define YAFFS_NTNODES_INTERNAL (YAFFS_NTNODES_LEVEL0 / 2)
37 #define YAFFS_TNODES_INTERNAL_BITS (YAFFS_TNODES_LEVEL0_BITS - 1)
38 #define YAFFS_TNODES_INTERNAL_MASK 0x7
39 #define YAFFS_TNODES_MAX_LEVEL 6
41 #define YAFFS_BYTES_PER_CHUNK 512
42 #define YAFFS_CHUNK_SIZE_SHIFT 9
44 #define YAFFS_BYTES_PER_SPARE 16
46 #define YAFFS_CHUNKS_PER_BLOCK 32
47 #define YAFFS_BYTES_PER_BLOCK (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
49 #define YAFFS_MAX_CHUNK_ID 0x000FFFFF
51 #define YAFFS_UNUSED_OBJECT_ID 0x0003FFFF
53 #define YAFFS_ALLOCATION_NOBJECTS 100
54 #define YAFFS_ALLOCATION_NTNODES 100
55 #define YAFFS_ALLOCATION_NLINKS 100
57 #define YAFFS_NOBJECT_BUCKETS 256
60 #define YAFFS_RESERVED_BLOCKS 5
62 #define YAFFS_OBJECT_SPACE 0x40000
63 #define YAFFS_MAX_NAME_LENGTH 255
65 #define YAFFS_MAX_ALIAS_LENGTH 159
67 #define YAFFS_OBJECTID_ROOT 1
68 #define YAFFS_OBJECTID_LOSTNFOUND 2
69 #define YAFFS_OBJECTID_UNLINKED 3
71 #define YAFFS_N_CACHE_CHUNKS 10
75 // Force the short operation cache on for WinCE
77 #define CONFIG_YAFFS_SHORT_OP_CACHE
81 // ChunkCache is used for short read/write operations.
88 __u8 data[YAFFS_BYTES_PER_CHUNK];
91 // Tags structures in RAM
92 // NB This uses bitfield. Bitfields should not stradle a u32 boundary otherwise
93 // the structure size will get blown out.
98 unsigned serialNumber:2;
99 unsigned byteCount:10;
100 unsigned objectId:18;
102 unsigned unusedStuff:2;
119 __u8 pageStatus; // set to 0 to delete the chunk
132 YAFFS_BLOCK_STATE_UddNKNOWN = 0,
133 YAFFS_BLOCK_STATE_SCANNING, // Used while the block is being scanned.
134 // NB Don't erase blocks while they're being scanned
136 YAFFS_BLOCK_STATE_EMPTY, // This block is empty
138 YAFFS_BLOCK_STATE_ALLOCATING, // This block is partially allocated.
139 // This is the one currently being used for page
140 // allocation. Should never be more than one of these
143 YAFFS_BLOCK_STATE_FULL, // All the pages in this block have been allocated.
144 // At least one page holds valid data.
146 YAFFS_BLOCK_STATE_DIRTY, // All pages have been allocated and deleted.
147 // Erase me, reuse me.
149 YAFFS_BLOCK_STATE_DEAD = 0x77 // This block has failed and is not in use
158 __u32 pageBits; // bitmap of pages in use
159 __u8 blockState; // One of the above block states
160 __u8 pagesInUse; // number of pages in use
161 __u8 needsRetiring:1; // Data has failed on this block, need to get valid data off
162 // and retire the block.
166 //////////////////// Object structure ///////////////////////////
167 // This is the object structure as stored on NAND
171 YAFFS_OBJECT_TYPE_UNKNOWN,
172 YAFFS_OBJECT_TYPE_FILE,
173 YAFFS_OBJECT_TYPE_SYMLINK,
174 YAFFS_OBJECT_TYPE_DIRECTORY,
175 YAFFS_OBJECT_TYPE_HARDLINK,
176 YAFFS_OBJECT_TYPE_SPECIAL
181 yaffs_ObjectType type;
183 // Apply to everything
185 __u16 sum; // checksum of name
186 char name[YAFFS_MAX_NAME_LENGTH + 1];
188 // Thes following apply to directories, files, symlinks - not hard links
189 __u32 st_mode; // protection
190 __u32 st_uid; // user ID of owner
191 __u32 st_gid; // group ID of owner
192 __u32 st_atime; // time of last access
193 __u32 st_mtime; // time of last modification
194 __u32 st_ctime; // time of last change
196 // File size applies to files only
199 // Equivalent object id applies to hard links only.
200 int equivalentObjectId;
202 // Alias is for symlinks only.
203 char alias[YAFFS_MAX_ALIAS_LENGTH + 1];
205 __u32 st_rdev; // device stuff for block and char devices (maj/min)
207 __u32 roomToGrow[12];
209 } yaffs_ObjectHeader;
213 //////////////////// Tnode ///////////////////////////
215 union yaffs_Tnode_union
217 union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
218 __u16 level0[YAFFS_NTNODES_LEVEL0];
222 typedef union yaffs_Tnode_union yaffs_Tnode;
224 struct yaffs_TnodeList_struct
226 struct yaffs_TnodeList_struct *next;
230 typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
234 /////////////////// Object ////////////////////////////////
235 // An object can be one of:
236 // - a directory (no data, has children links
237 // - a regular file (data.... not prunes :->).
238 // - a symlink [symbolic link] (the alias).
245 __u32 scannedFileSize;
248 } yaffs_FileStructure;
252 struct list_head children; // list of child links
253 } yaffs_DirectoryStructure;
258 } yaffs_SymLinkStructure;
262 struct yaffs_ObjectStruct *equivalentObject;
263 __u32 equivalentObjectId;
264 } yaffs_HardLinkStructure;
268 yaffs_FileStructure fileVariant;
269 yaffs_DirectoryStructure directoryVariant;
270 yaffs_SymLinkStructure symLinkVariant;
271 yaffs_HardLinkStructure hardLinkVariant;
272 } yaffs_ObjectVariant;
275 struct yaffs_ObjectStruct
277 __u8 deleted: 1; // This should only apply to unlinked files.
278 __u8 unlinked: 1; // An unlinked file. The file should be in the unlinked pseudo directory.
279 __u8 fake:1; // A fake object has no presence on NAND.
280 __u8 renameAllowed:1;
281 __u8 unlinkAllowed:1;
282 __u8 dirty:1; // the object needs to be written to flash
283 __u8 valid:1; // When the file system is being loaded up, this
284 // object might be created before the data
285 // is available (ie. file data records appear before the header).
286 __u8 serial; // serial number of chunk in NAND. Store here so we don't have to
287 // read back the old one to update.
288 __u16 sum; // sum of the name to speed searching
290 struct yaffs_DeviceStruct *myDev; // The device I'm on
293 struct list_head hashLink; // list of objects in this hash bucket
296 struct list_head hardLinks; // all the equivalent hard linked objects
298 // directory structure stuff
299 struct yaffs_ObjectStruct *parent; //my parent directory
300 struct list_head siblings; // siblings in a directory
301 // also used for linking up the free list
303 // Where's my data in NAND?
304 int chunkId; // where it lives
308 __u32 objectId; // the object id value
311 __u32 st_mode; // protection
312 __u32 st_uid; // user ID of owner
313 __u32 st_gid; // group ID of owner
314 __u32 st_atime; // time of last access
315 __u32 st_mtime; // time of last modification
316 __u32 st_ctime; // time of last change
317 __u32 st_rdev; // device stuff for block and char devices
324 struct inode *myInode;
329 yaffs_ObjectType variantType;
331 yaffs_ObjectVariant variant;
337 typedef struct yaffs_ObjectStruct yaffs_Object;
340 struct yaffs_ObjectList_struct
342 yaffs_Object *objects;
343 struct yaffs_ObjectList_struct *next;
346 typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
350 struct list_head list;
352 } yaffs_ObjectBucket;
355 //////////////////// Device ////////////////////////////////
357 struct yaffs_DeviceStruct
359 // Entry parameters set up way early. Yaffs sets up the rest.
360 // __u32 nBlocks; // Size of whole device in blocks
361 __u32 startBlock; // Start block we're allowed to use
362 __u32 endBlock; // End block we're allowed to use
363 __u16 chunkGroupBits; // 0 for devices <= 32MB. else log2(nchunks) - 16
364 __u16 chunkGroupSize; // == 2^^chunkGroupBits
367 void *genericDevice; // Pointer to device context
368 // On an mtd this holds the mtd pointer.
372 struct semaphore sem;// Semaphore for waiting on erasure.
373 struct semaphore grossLock; // Gross locking semaphore
378 // NAND access functions (Must be set before calling YAFFS)
380 int (*writeChunkToNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
381 int (*readChunkFromNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
382 int (*eraseBlockInNAND)(struct yaffs_DeviceStruct *dev,int blockInNAND);
383 int (*initialiseNAND)(struct yaffs_DeviceStruct *dev);
386 void (*putSuperFunc)(struct super_block *sb);
389 // Runtime parameters.
390 yaffs_BlockInfo *blockInfo;
393 __u32 allocationPage;
397 yaffs_Tnode *freeTnodes;
399 yaffs_TnodeList *allocatedTnodeList;
403 yaffs_Object *freeObjects;
406 yaffs_ObjectList *allocatedObjectList;
408 yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
412 int currentDirtyChecker; // Used to find current dirtiest block
414 int garbageCollectionRequired;
416 // Operations since mount
421 int garbageCollections;
425 yaffs_Object *rootDir;
426 yaffs_Object *lostNFoundDir;
428 // Buffer areas for storing data to recover from write failures
429 __u8 bufferedData[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
430 yaffs_Spare bufferedSpare[YAFFS_CHUNKS_PER_BLOCK];
431 int bufferedBlock; // Which block is buffered here?
432 int doingBufferedBlockRewrite;
434 int blockSelectedForGC;
436 #ifdef CONFIG_YAFFS_SHORT_OP_CACHE
437 yaffs_ChunkCache srCache[YAFFS_N_CACHE_CHUNKS];
442 // Stuff for background deletion and unlinked files.
443 yaffs_Object *unlinkedDir; // Directory where unlinked and deleted files live.
444 yaffs_Object *unlinkedDeletion; // Current file being background deleted.
445 int nDeletedFiles; // Count of files awaiting deletion;
450 typedef struct yaffs_DeviceStruct yaffs_Device;
454 //////////// YAFFS Functions //////////////////
456 int yaffs_GutsInitialise(yaffs_Device *dev);
457 void yaffs_Deinitialise(yaffs_Device *dev);
459 int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev);
463 int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName);
465 // generic Object functions
466 int yaffs_Unlink(yaffs_Object *dir, const char *name);
467 int yaffs_DeleteFile(yaffs_Object *obj);
469 // Object access functions.
470 int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize);
471 int yaffs_GetObjectFileLength(yaffs_Object *obj);
472 int yaffs_GetObjectInode(yaffs_Object *obj);
473 unsigned yaffs_GetObjectType(yaffs_Object *obj);
474 int yaffs_GetObjectLinkCount(yaffs_Object *obj);
476 // Change inode attributes
477 int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr);
478 int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr);
481 int yaffs_ReadDataFromFile(yaffs_Object *obj, __u8 *buffer, __u32 offset, int nBytes);
482 int yaffs_WriteDataToFile(yaffs_Object *obj, const __u8 *buffer, __u32 offset, int nBytes);
483 int yaffs_ResizeFile(yaffs_Object *obj, int newSize);
485 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
486 int yaffs_FlushFile(yaffs_Object *obj);
489 // Directory operations
490 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
491 yaffs_Object *yaffs_FindObjectByName(yaffs_Object *theDir,const char *name);
492 int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *));
494 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number);
497 yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject);
499 yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj);
501 // Symlink operations
502 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const char *name, __u32 mode, __u32 uid, __u32 gid, const char *alias);
503 char *yaffs_GetSymlinkAlias(yaffs_Object *obj);
505 // Special inodes (fifos, sockets and devices)
506 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid,__u32 rdev);
509 // Special directories
510 yaffs_Object *yaffs_Root(yaffs_Device *dev);
511 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev);
515 int yaffs_DumpObject(yaffs_Object *obj);
518 void yaffs_GutsTest(yaffs_Device *dev);