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.
15 * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
18 #ifndef __YAFFS_GUTS_H__
19 #define __YAFFS_GUTS_H__
21 #include "devextras.h"
31 // And what have we got...
32 #define YAFFS_MAGIC 0x5941FF53
34 #define YAFFS_NTNODES_LEVEL0 16
35 #define YAFFS_TNODES_LEVEL0_BITS 4
36 #define YAFFS_TNODES_LEVEL0_MASK 0xf
38 #define YAFFS_NTNODES_INTERNAL (YAFFS_NTNODES_LEVEL0 / 2)
39 #define YAFFS_TNODES_INTERNAL_BITS (YAFFS_TNODES_LEVEL0_BITS - 1)
40 #define YAFFS_TNODES_INTERNAL_MASK 0x7
41 #define YAFFS_TNODES_MAX_LEVEL 6
43 #define YAFFS_BYTES_PER_CHUNK 512
44 #define YAFFS_CHUNK_SIZE_SHIFT 9
46 #define YAFFS_BYTES_PER_SPARE 16
48 #define YAFFS_CHUNKS_PER_BLOCK 32
49 #define YAFFS_BYTES_PER_BLOCK (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
51 #define YAFFS_MAX_CHUNK_ID 0x000FFFFF
53 #define YAFFS_UNUSED_OBJECT_ID 0x0003FFFF
55 #define YAFFS_ALLOCATION_NOBJECTS 100
56 #define YAFFS_ALLOCATION_NTNODES 100
57 #define YAFFS_ALLOCATION_NLINKS 100
59 #define YAFFS_NOBJECT_BUCKETS 256
62 #define YAFFS_RESERVED_BLOCKS 5
64 #define YAFFS_OBJECT_SPACE 0x40000
65 #define YAFFS_MAX_NAME_LENGTH 255
67 #define YAFFS_MAX_ALIAS_LENGTH 159
69 #define YAFFS_OBJECTID_ROOT 1
70 #define YAFFS_OBJECTID_LOSTNFOUND 2
71 #define YAFFS_OBJECTID_UNLINKED 3
73 #define YAFFS_N_CACHE_CHUNKS 10
77 // Force the short operation cache on for WinCE
79 #define CONFIG_YAFFS_SHORT_OP_CACHE
83 // ChunkCache is used for short read/write operations.
90 __u8 data[YAFFS_BYTES_PER_CHUNK];
93 // Tags structures in RAM
94 // NB This uses bitfield. Bitfields should not stradle a u32 boundary otherwise
95 // the structure size will get blown out.
100 unsigned serialNumber:2;
101 unsigned byteCount:10;
102 unsigned objectId:18;
104 unsigned unusedStuff:2;
121 __u8 pageStatus; // set to 0 to delete the chunk
134 YAFFS_BLOCK_STATE_UddNKNOWN = 0,
135 YAFFS_BLOCK_STATE_SCANNING, // Used while the block is being scanned.
136 // NB Don't erase blocks while they're being scanned
138 YAFFS_BLOCK_STATE_EMPTY, // This block is empty
140 YAFFS_BLOCK_STATE_ALLOCATING, // This block is partially allocated.
141 // This is the one currently being used for page
142 // allocation. Should never be more than one of these
145 YAFFS_BLOCK_STATE_FULL, // All the pages in this block have been allocated.
146 // At least one page holds valid data.
148 YAFFS_BLOCK_STATE_DIRTY, // All pages have been allocated and deleted.
149 // Erase me, reuse me.
151 YAFFS_BLOCK_STATE_DEAD = 0x77 // This block has failed and is not in use
160 __u32 pageBits; // bitmap of pages in use
161 __u8 blockState; // One of the above block states
162 __u8 pagesInUse; // number of pages in use
163 __u8 needsRetiring:1; // Data has failed on this block, need to get valid data off
164 // and retire the block.
168 //////////////////// Object structure ///////////////////////////
169 // This is the object structure as stored on NAND
173 YAFFS_OBJECT_TYPE_UNKNOWN,
174 YAFFS_OBJECT_TYPE_FILE,
175 YAFFS_OBJECT_TYPE_SYMLINK,
176 YAFFS_OBJECT_TYPE_DIRECTORY,
177 YAFFS_OBJECT_TYPE_HARDLINK,
178 YAFFS_OBJECT_TYPE_SPECIAL
183 yaffs_ObjectType type;
185 // Apply to everything
187 __u16 sum; // checksum of name
188 char name[YAFFS_MAX_NAME_LENGTH + 1];
190 // Thes following apply to directories, files, symlinks - not hard links
191 __u32 st_mode; // protection
192 __u32 st_uid; // user ID of owner
193 __u32 st_gid; // group ID of owner
194 __u32 st_atime; // time of last access
195 __u32 st_mtime; // time of last modification
196 __u32 st_ctime; // time of last change
198 // File size applies to files only
201 // Equivalent object id applies to hard links only.
202 int equivalentObjectId;
204 // Alias is for symlinks only.
205 char alias[YAFFS_MAX_ALIAS_LENGTH + 1];
207 __u32 st_rdev; // device stuff for block and char devices (maj/min)
209 __u32 roomToGrow[12];
211 } yaffs_ObjectHeader;
215 //////////////////// Tnode ///////////////////////////
217 union yaffs_Tnode_union
219 union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
220 __u16 level0[YAFFS_NTNODES_LEVEL0];
224 typedef union yaffs_Tnode_union yaffs_Tnode;
226 struct yaffs_TnodeList_struct
228 struct yaffs_TnodeList_struct *next;
232 typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
236 /////////////////// Object ////////////////////////////////
237 // An object can be one of:
238 // - a directory (no data, has children links
239 // - a regular file (data.... not prunes :->).
240 // - a symlink [symbolic link] (the alias).
247 __u32 scannedFileSize;
250 } yaffs_FileStructure;
254 struct list_head children; // list of child links
255 } yaffs_DirectoryStructure;
260 } yaffs_SymLinkStructure;
264 struct yaffs_ObjectStruct *equivalentObject;
265 __u32 equivalentObjectId;
266 } yaffs_HardLinkStructure;
270 yaffs_FileStructure fileVariant;
271 yaffs_DirectoryStructure directoryVariant;
272 yaffs_SymLinkStructure symLinkVariant;
273 yaffs_HardLinkStructure hardLinkVariant;
274 } yaffs_ObjectVariant;
277 struct yaffs_ObjectStruct
279 __u8 deleted: 1; // This should only apply to unlinked files.
280 __u8 unlinked: 1; // An unlinked file. The file should be in the unlinked pseudo directory.
281 __u8 fake:1; // A fake object has no presence on NAND.
282 __u8 renameAllowed:1;
283 __u8 unlinkAllowed:1;
284 __u8 dirty:1; // the object needs to be written to flash
285 __u8 valid:1; // When the file system is being loaded up, this
286 // object might be created before the data
287 // is available (ie. file data records appear before the header).
288 __u8 serial; // serial number of chunk in NAND. Store here so we don't have to
289 // read back the old one to update.
290 __u16 sum; // sum of the name to speed searching
292 struct yaffs_DeviceStruct *myDev; // The device I'm on
295 struct list_head hashLink; // list of objects in this hash bucket
298 struct list_head hardLinks; // all the equivalent hard linked objects
300 // directory structure stuff
301 struct yaffs_ObjectStruct *parent; //my parent directory
302 struct list_head siblings; // siblings in a directory
303 // also used for linking up the free list
305 // Where's my data in NAND?
306 int chunkId; // where it lives
310 __u32 objectId; // the object id value
313 __u32 st_mode; // protection
314 __u32 st_uid; // user ID of owner
315 __u32 st_gid; // group ID of owner
316 __u32 st_atime; // time of last access
317 __u32 st_mtime; // time of last modification
318 __u32 st_ctime; // time of last change
319 __u32 st_rdev; // device stuff for block and char devices
326 struct inode *myInode;
331 yaffs_ObjectType variantType;
333 yaffs_ObjectVariant variant;
339 typedef struct yaffs_ObjectStruct yaffs_Object;
342 struct yaffs_ObjectList_struct
344 yaffs_Object *objects;
345 struct yaffs_ObjectList_struct *next;
348 typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
352 struct list_head list;
354 } yaffs_ObjectBucket;
357 //////////////////// Device ////////////////////////////////
359 struct yaffs_DeviceStruct
361 // Entry parameters set up way early. Yaffs sets up the rest.
362 // __u32 nBlocks; // Size of whole device in blocks
363 __u32 startBlock; // Start block we're allowed to use
364 __u32 endBlock; // End block we're allowed to use
365 __u16 chunkGroupBits; // 0 for devices <= 32MB. else log2(nchunks) - 16
366 __u16 chunkGroupSize; // == 2^^chunkGroupBits
369 void *genericDevice; // Pointer to device context
370 // On an mtd this holds the mtd pointer.
374 struct semaphore sem;// Semaphore for waiting on erasure.
375 struct semaphore grossLock; // Gross locking semaphore
380 // NAND access functions (Must be set before calling YAFFS)
382 int (*writeChunkToNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
383 int (*readChunkFromNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
384 int (*eraseBlockInNAND)(struct yaffs_DeviceStruct *dev,int blockInNAND);
385 int (*initialiseNAND)(struct yaffs_DeviceStruct *dev);
388 void (*putSuperFunc)(struct super_block *sb);
391 // Runtime parameters.
392 yaffs_BlockInfo *blockInfo;
395 __u32 allocationPage;
399 yaffs_Tnode *freeTnodes;
401 yaffs_TnodeList *allocatedTnodeList;
405 yaffs_Object *freeObjects;
408 yaffs_ObjectList *allocatedObjectList;
410 yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
414 int currentDirtyChecker; // Used to find current dirtiest block
416 int garbageCollectionRequired;
418 // Operations since mount
423 int garbageCollections;
427 yaffs_Object *rootDir;
428 yaffs_Object *lostNFoundDir;
430 // Buffer areas for storing data to recover from write failures
431 __u8 bufferedData[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
432 yaffs_Spare bufferedSpare[YAFFS_CHUNKS_PER_BLOCK];
433 int bufferedBlock; // Which block is buffered here?
434 int doingBufferedBlockRewrite;
436 int blockSelectedForGC;
438 #ifdef CONFIG_YAFFS_SHORT_OP_CACHE
439 yaffs_ChunkCache srCache[YAFFS_N_CACHE_CHUNKS];
444 // Stuff for background deletion and unlinked files.
445 yaffs_Object *unlinkedDir; // Directory where unlinked and deleted files live.
446 yaffs_Object *unlinkedDeletion; // Current file being background deleted.
447 int nDeletedFiles; // Count of files awaiting deletion;
448 int nUnlinkedFiles; // Count of unlinked files.
449 int nBackgroundDeletions; // Count of background deletions.
453 typedef struct yaffs_DeviceStruct yaffs_Device;
457 //////////// YAFFS Functions //////////////////
459 int yaffs_GutsInitialise(yaffs_Device *dev);
460 void yaffs_Deinitialise(yaffs_Device *dev);
462 int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev);
466 int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName);
468 // generic Object functions
469 int yaffs_Unlink(yaffs_Object *dir, const char *name);
470 int yaffs_DeleteFile(yaffs_Object *obj);
472 // Object access functions.
473 int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize);
474 int yaffs_GetObjectFileLength(yaffs_Object *obj);
475 int yaffs_GetObjectInode(yaffs_Object *obj);
476 unsigned yaffs_GetObjectType(yaffs_Object *obj);
477 int yaffs_GetObjectLinkCount(yaffs_Object *obj);
479 // Change inode attributes
480 int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr);
481 int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr);
484 int yaffs_ReadDataFromFile(yaffs_Object *obj, __u8 *buffer, __u32 offset, int nBytes);
485 int yaffs_WriteDataToFile(yaffs_Object *obj, const __u8 *buffer, __u32 offset, int nBytes);
486 int yaffs_ResizeFile(yaffs_Object *obj, int newSize);
488 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
489 int yaffs_FlushFile(yaffs_Object *obj);
492 // Directory operations
493 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
494 yaffs_Object *yaffs_FindObjectByName(yaffs_Object *theDir,const char *name);
495 int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *));
497 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number);
500 yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject);
502 yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj);
504 // Symlink operations
505 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const char *name, __u32 mode, __u32 uid, __u32 gid, const char *alias);
506 char *yaffs_GetSymlinkAlias(yaffs_Object *obj);
508 // Special inodes (fifos, sockets and devices)
509 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid,__u32 rdev);
512 // Special directories
513 yaffs_Object *yaffs_Root(yaffs_Device *dev);
514 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev);
518 int yaffs_DumpObject(yaffs_Object *obj);
521 void yaffs_GutsTest(yaffs_Device *dev);