xref: /openbmc/u-boot/fs/yaffs2/yaffs_guts.h (revision 753ac610880e6e563d0384bb114f8b41df89e520)
1  /*
2   * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
3   *
4   * Copyright (C) 2002-2011 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 Lesser General Public License version 2.1 as
11   * published by the Free Software Foundation.
12   *
13   * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
14   */
15  
16  #ifndef __YAFFS_GUTS_H__
17  #define __YAFFS_GUTS_H__
18  
19  #include "yportenv.h"
20  
21  #define YAFFS_OK	1
22  #define YAFFS_FAIL  0
23  
24  /* Give us a  Y=0x59,
25   * Give us an A=0x41,
26   * Give us an FF=0xff
27   * Give us an S=0x53
28   * And what have we got...
29   */
30  #define YAFFS_MAGIC			0x5941ff53
31  
32  /*
33   * Tnodes form a tree with the tnodes in "levels"
34   * Levels greater than 0 hold 8 slots which point to other tnodes.
35   * Those at level 0 hold 16 slots which point to chunks in NAND.
36   *
37   * A maximum level of 8 thust supports files of size up to:
38   *
39   * 2^(3*MAX_LEVEL+4)
40   *
41   * Thus a max level of 8 supports files with up to 2^^28 chunks which gives
42   * a maximum file size of arounf 51Gbytees with 2k chunks.
43   */
44  #define YAFFS_NTNODES_LEVEL0		16
45  #define YAFFS_TNODES_LEVEL0_BITS	4
46  #define YAFFS_TNODES_LEVEL0_MASK	0xf
47  
48  #define YAFFS_NTNODES_INTERNAL		(YAFFS_NTNODES_LEVEL0 / 2)
49  #define YAFFS_TNODES_INTERNAL_BITS	(YAFFS_TNODES_LEVEL0_BITS - 1)
50  #define YAFFS_TNODES_INTERNAL_MASK	0x7
51  #define YAFFS_TNODES_MAX_LEVEL		8
52  #define YAFFS_TNODES_MAX_BITS		(YAFFS_TNODES_LEVEL0_BITS + \
53  					YAFFS_TNODES_INTERNAL_BITS * \
54  					YAFFS_TNODES_MAX_LEVEL)
55  #define YAFFS_MAX_CHUNK_ID		((1 << YAFFS_TNODES_MAX_BITS) - 1)
56  
57  /* Constants for YAFFS1 mode */
58  #define YAFFS_BYTES_PER_SPARE		16
59  #define YAFFS_BYTES_PER_CHUNK		512
60  #define YAFFS_CHUNK_SIZE_SHIFT		9
61  #define YAFFS_CHUNKS_PER_BLOCK		32
62  #define YAFFS_BYTES_PER_BLOCK	(YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
63  
64  #define YAFFS_MIN_YAFFS2_CHUNK_SIZE	1024
65  #define YAFFS_MIN_YAFFS2_SPARE_SIZE	32
66  
67  
68  
69  #define YAFFS_ALLOCATION_NOBJECTS	100
70  #define YAFFS_ALLOCATION_NTNODES	100
71  #define YAFFS_ALLOCATION_NLINKS		100
72  
73  #define YAFFS_NOBJECT_BUCKETS		256
74  
75  #define YAFFS_OBJECT_SPACE		0x40000
76  #define YAFFS_MAX_OBJECT_ID		(YAFFS_OBJECT_SPACE - 1)
77  
78  /* Binary data version stamps */
79  #define YAFFS_SUMMARY_VERSION		1
80  #define YAFFS_CHECKPOINT_VERSION	6
81  
82  #ifdef CONFIG_YAFFS_UNICODE
83  #define YAFFS_MAX_NAME_LENGTH		127
84  #define YAFFS_MAX_ALIAS_LENGTH		79
85  #else
86  #define YAFFS_MAX_NAME_LENGTH		255
87  #define YAFFS_MAX_ALIAS_LENGTH		159
88  #endif
89  
90  #define YAFFS_SHORT_NAME_LENGTH		15
91  
92  /* Some special object ids for pseudo objects */
93  #define YAFFS_OBJECTID_ROOT		1
94  #define YAFFS_OBJECTID_LOSTNFOUND	2
95  #define YAFFS_OBJECTID_UNLINKED		3
96  #define YAFFS_OBJECTID_DELETED		4
97  
98  /* Fake object Id for summary data */
99  #define YAFFS_OBJECTID_SUMMARY		0x10
100  
101  /* Pseudo object ids for checkpointing */
102  #define YAFFS_OBJECTID_CHECKPOINT_DATA	0x20
103  #define YAFFS_SEQUENCE_CHECKPOINT_DATA	0x21
104  
105  #define YAFFS_MAX_SHORT_OP_CACHES	20
106  
107  #define YAFFS_N_TEMP_BUFFERS		6
108  
109  /* We limit the number attempts at sucessfully saving a chunk of data.
110   * Small-page devices have 32 pages per block; large-page devices have 64.
111   * Default to something in the order of 5 to 10 blocks worth of chunks.
112   */
113  #define YAFFS_WR_ATTEMPTS		(5*64)
114  
115  /* Sequence numbers are used in YAFFS2 to determine block allocation order.
116   * The range is limited slightly to help distinguish bad numbers from good.
117   * This also allows us to perhaps in the future use special numbers for
118   * special purposes.
119   * EFFFFF00 allows the allocation of 8 blocks/second (~1Mbytes) for 15 years,
120   * and is a larger number than the lifetime of a 2GB device.
121   */
122  #define YAFFS_LOWEST_SEQUENCE_NUMBER	0x00001000
123  #define YAFFS_HIGHEST_SEQUENCE_NUMBER	0xefffff00
124  
125  /* Special sequence number for bad block that failed to be marked bad */
126  #define YAFFS_SEQUENCE_BAD_BLOCK	0xffff0000
127  
128  /* ChunkCache is used for short read/write operations.*/
129  struct yaffs_cache {
130  	struct yaffs_obj *object;
131  	int chunk_id;
132  	int last_use;
133  	int dirty;
134  	int n_bytes;		/* Only valid if the cache is dirty */
135  	int locked;		/* Can't push out or flush while locked. */
136  	u8 *data;
137  };
138  
139  /* yaffs1 tags structures in RAM
140   * NB This uses bitfield. Bitfields should not straddle a u32 boundary
141   * otherwise the structure size will get blown out.
142   */
143  
144  struct yaffs_tags {
145  	unsigned chunk_id:20;
146  	unsigned serial_number:2;
147  	unsigned n_bytes_lsb:10;
148  	unsigned obj_id:18;
149  	unsigned ecc:12;
150  	unsigned n_bytes_msb:2;
151  };
152  
153  union yaffs_tags_union {
154  	struct yaffs_tags as_tags;
155  	u8 as_bytes[8];
156  };
157  
158  
159  /* Stuff used for extended tags in YAFFS2 */
160  
161  enum yaffs_ecc_result {
162  	YAFFS_ECC_RESULT_UNKNOWN,
163  	YAFFS_ECC_RESULT_NO_ERROR,
164  	YAFFS_ECC_RESULT_FIXED,
165  	YAFFS_ECC_RESULT_UNFIXED
166  };
167  
168  enum yaffs_obj_type {
169  	YAFFS_OBJECT_TYPE_UNKNOWN,
170  	YAFFS_OBJECT_TYPE_FILE,
171  	YAFFS_OBJECT_TYPE_SYMLINK,
172  	YAFFS_OBJECT_TYPE_DIRECTORY,
173  	YAFFS_OBJECT_TYPE_HARDLINK,
174  	YAFFS_OBJECT_TYPE_SPECIAL
175  };
176  
177  #define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
178  
179  struct yaffs_ext_tags {
180  	unsigned chunk_used;	/*  Status of the chunk: used or unused */
181  	unsigned obj_id;	/* If 0 this is not used */
182  	unsigned chunk_id;	/* If 0 this is a header, else a data chunk */
183  	unsigned n_bytes;	/* Only valid for data chunks */
184  
185  	/* The following stuff only has meaning when we read */
186  	enum yaffs_ecc_result ecc_result;
187  	unsigned block_bad;
188  
189  	/* YAFFS 1 stuff */
190  	unsigned is_deleted;	/* The chunk is marked deleted */
191  	unsigned serial_number;	/* Yaffs1 2-bit serial number */
192  
193  	/* YAFFS2 stuff */
194  	unsigned seq_number;	/* The sequence number of this block */
195  
196  	/* Extra info if this is an object header (YAFFS2 only) */
197  
198  	unsigned extra_available;	/* Extra info available if not zero */
199  	unsigned extra_parent_id;	/* The parent object */
200  	unsigned extra_is_shrink;	/* Is it a shrink header? */
201  	unsigned extra_shadows;	/* Does this shadow another object? */
202  
203  	enum yaffs_obj_type extra_obj_type;	/* What object type? */
204  
205  	loff_t extra_file_size;		/* Length if it is a file */
206  	unsigned extra_equiv_id;	/* Equivalent object for a hard link */
207  };
208  
209  /* Spare structure for YAFFS1 */
210  struct yaffs_spare {
211  	u8 tb0;
212  	u8 tb1;
213  	u8 tb2;
214  	u8 tb3;
215  	u8 page_status;		/* set to 0 to delete the chunk */
216  	u8 block_status;
217  	u8 tb4;
218  	u8 tb5;
219  	u8 ecc1[3];
220  	u8 tb6;
221  	u8 tb7;
222  	u8 ecc2[3];
223  };
224  
225  /*Special structure for passing through to mtd */
226  struct yaffs_nand_spare {
227  	struct yaffs_spare spare;
228  	int eccres1;
229  	int eccres2;
230  };
231  
232  /* Block data in RAM */
233  
234  enum yaffs_block_state {
235  	YAFFS_BLOCK_STATE_UNKNOWN = 0,
236  
237  	YAFFS_BLOCK_STATE_SCANNING,
238  	/* Being scanned */
239  
240  	YAFFS_BLOCK_STATE_NEEDS_SCAN,
241  	/* The block might have something on it (ie it is allocating or full,
242  	 * perhaps empty) but it needs to be scanned to determine its true
243  	 * state.
244  	 * This state is only valid during scanning.
245  	 * NB We tolerate empty because the pre-scanner might be incapable of
246  	 * deciding
247  	 * However, if this state is returned on a YAFFS2 device,
248  	 * then we expect a sequence number
249  	 */
250  
251  	YAFFS_BLOCK_STATE_EMPTY,
252  	/* This block is empty */
253  
254  	YAFFS_BLOCK_STATE_ALLOCATING,
255  	/* This block is partially allocated.
256  	 * At least one page holds valid data.
257  	 * This is the one currently being used for page
258  	 * allocation. Should never be more than one of these.
259  	 * If a block is only partially allocated at mount it is treated as
260  	 * full.
261  	 */
262  
263  	YAFFS_BLOCK_STATE_FULL,
264  	/* All the pages in this block have been allocated.
265  	 * If a block was only partially allocated when mounted we treat
266  	 * it as fully allocated.
267  	 */
268  
269  	YAFFS_BLOCK_STATE_DIRTY,
270  	/* The block was full and now all chunks have been deleted.
271  	 * Erase me, reuse me.
272  	 */
273  
274  	YAFFS_BLOCK_STATE_CHECKPOINT,
275  	/* This block is assigned to holding checkpoint data. */
276  
277  	YAFFS_BLOCK_STATE_COLLECTING,
278  	/* This block is being garbage collected */
279  
280  	YAFFS_BLOCK_STATE_DEAD
281  	    /* This block has failed and is not in use */
282  };
283  
284  #define	YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
285  
286  struct yaffs_block_info {
287  
288  	int soft_del_pages:10;	/* number of soft deleted pages */
289  	int pages_in_use:10;	/* number of pages in use */
290  	unsigned block_state:4;	/* One of the above block states. */
291  				/* NB use unsigned because enum is sometimes
292  				 * an int */
293  	u32 needs_retiring:1;	/* Data has failed on this block, */
294  				/*need to get valid data off and retire*/
295  	u32 skip_erased_check:1;/* Skip the erased check on this block */
296  	u32 gc_prioritise:1;	/* An ECC check or blank check has failed.
297  				   Block should be prioritised for GC */
298  	u32 chunk_error_strikes:3;	/* How many times we've had ecc etc
299  				failures on this block and tried to reuse it */
300  	u32 has_summary:1;	/* The block has a summary */
301  
302  	u32 has_shrink_hdr:1;	/* This block has at least one shrink header */
303  	u32 seq_number;		/* block sequence number for yaffs2 */
304  
305  };
306  
307  /* -------------------------- Object structure -------------------------------*/
308  /* This is the object structure as stored on NAND */
309  
310  struct yaffs_obj_hdr {
311  	enum yaffs_obj_type type;
312  
313  	/* Apply to everything  */
314  	int parent_obj_id;
315  	u16 sum_no_longer_used;	/* checksum of name. No longer used */
316  	YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
317  
318  	/* The following apply to all object types except for hard links */
319  	u32 yst_mode;		/* protection */
320  
321  	u32 yst_uid;
322  	u32 yst_gid;
323  	u32 yst_atime;
324  	u32 yst_mtime;
325  	u32 yst_ctime;
326  
327  	/* File size  applies to files only */
328  	u32 file_size_low;
329  
330  	/* Equivalent object id applies to hard links only. */
331  	int equiv_id;
332  
333  	/* Alias is for symlinks only. */
334  	YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
335  
336  	u32 yst_rdev;	/* stuff for block and char devices (major/min) */
337  
338  	u32 win_ctime[2];
339  	u32 win_atime[2];
340  	u32 win_mtime[2];
341  
342  	u32 inband_shadowed_obj_id;
343  	u32 inband_is_shrink;
344  
345  	u32 file_size_high;
346  	u32 reserved[1];
347  	int shadows_obj;	/* This object header shadows the
348  				specified object if > 0 */
349  
350  	/* is_shrink applies to object headers written when wemake a hole. */
351  	u32 is_shrink;
352  
353  };
354  
355  /*--------------------------- Tnode -------------------------- */
356  
357  struct yaffs_tnode {
358  	struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
359  };
360  
361  /*------------------------  Object -----------------------------*/
362  /* An object can be one of:
363   * - a directory (no data, has children links
364   * - a regular file (data.... not prunes :->).
365   * - a symlink [symbolic link] (the alias).
366   * - a hard link
367   */
368  
369  struct yaffs_file_var {
370  	loff_t file_size;
371  	loff_t scanned_size;
372  	loff_t shrink_size;
373  	int top_level;
374  	struct yaffs_tnode *top;
375  };
376  
377  struct yaffs_dir_var {
378  	struct list_head children;	/* list of child links */
379  	struct list_head dirty;	/* Entry for list of dirty directories */
380  };
381  
382  struct yaffs_symlink_var {
383  	YCHAR *alias;
384  };
385  
386  struct yaffs_hardlink_var {
387  	struct yaffs_obj *equiv_obj;
388  	u32 equiv_id;
389  };
390  
391  union yaffs_obj_var {
392  	struct yaffs_file_var file_variant;
393  	struct yaffs_dir_var dir_variant;
394  	struct yaffs_symlink_var symlink_variant;
395  	struct yaffs_hardlink_var hardlink_variant;
396  };
397  
398  struct yaffs_obj {
399  	u8 deleted:1;		/* This should only apply to unlinked files. */
400  	u8 soft_del:1;		/* it has also been soft deleted */
401  	u8 unlinked:1;		/* An unlinked file.*/
402  	u8 fake:1;		/* A fake object has no presence on NAND. */
403  	u8 rename_allowed:1;	/* Some objects cannot be renamed. */
404  	u8 unlink_allowed:1;
405  	u8 dirty:1;		/* the object needs to be written to flash */
406  	u8 valid:1;		/* When the file system is being loaded up, this
407  				 * object might be created before the data
408  				 * is available
409  				 * ie. file data chunks encountered before
410  				* the header.
411  				 */
412  	u8 lazy_loaded:1;	/* This object has been lazy loaded and
413  				 * is missing some detail */
414  
415  	u8 defered_free:1;	/* Object is removed from NAND, but is
416  				 * still in the inode cache.
417  				 * Free of object is defered.
418  				 * until the inode is released.
419  				 */
420  	u8 being_created:1;	/* This object is still being created
421  				 * so skip some verification checks. */
422  	u8 is_shadowed:1;	/* This object is shadowed on the way
423  				 * to being renamed. */
424  
425  	u8 xattr_known:1;	/* We know if this has object has xattribs
426  				 * or not. */
427  	u8 has_xattr:1;		/* This object has xattribs.
428  				 * Only valid if xattr_known. */
429  
430  	u8 serial;		/* serial number of chunk in NAND.*/
431  	u16 sum;		/* sum of the name to speed searching */
432  
433  	struct yaffs_dev *my_dev;	/* The device I'm on */
434  
435  	struct list_head hash_link;	/* list of objects in hash bucket */
436  
437  	struct list_head hard_links;	/* hard linked object chain*/
438  
439  	/* directory structure stuff */
440  	/* also used for linking up the free list */
441  	struct yaffs_obj *parent;
442  	struct list_head siblings;
443  
444  	/* Where's my object header in NAND? */
445  	int hdr_chunk;
446  
447  	int n_data_chunks;	/* Number of data chunks for this file. */
448  
449  	u32 obj_id;		/* the object id value */
450  
451  	u32 yst_mode;
452  
453  	YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];
454  
455  #ifdef CONFIG_YAFFS_WINCE
456  	u32 win_ctime[2];
457  	u32 win_mtime[2];
458  	u32 win_atime[2];
459  #else
460  	u32 yst_uid;
461  	u32 yst_gid;
462  	u32 yst_atime;
463  	u32 yst_mtime;
464  	u32 yst_ctime;
465  #endif
466  
467  	u32 yst_rdev;
468  
469  	void *my_inode;
470  
471  	enum yaffs_obj_type variant_type;
472  
473  	union yaffs_obj_var variant;
474  
475  };
476  
477  struct yaffs_obj_bucket {
478  	struct list_head list;
479  	int count;
480  };
481  
482  /* yaffs_checkpt_obj holds the definition of an object as dumped
483   * by checkpointing.
484   */
485  
486  struct yaffs_checkpt_obj {
487  	int struct_type;
488  	u32 obj_id;
489  	u32 parent_id;
490  	int hdr_chunk;
491  	enum yaffs_obj_type variant_type:3;
492  	u8 deleted:1;
493  	u8 soft_del:1;
494  	u8 unlinked:1;
495  	u8 fake:1;
496  	u8 rename_allowed:1;
497  	u8 unlink_allowed:1;
498  	u8 serial;
499  	int n_data_chunks;
500  	loff_t size_or_equiv_obj;
501  };
502  
503  /*--------------------- Temporary buffers ----------------
504   *
505   * These are chunk-sized working buffers. Each device has a few.
506   */
507  
508  struct yaffs_buffer {
509  	u8 *buffer;
510  	int in_use;
511  };
512  
513  /*----------------- Device ---------------------------------*/
514  
515  struct yaffs_param {
516  	const YCHAR *name;
517  
518  	/*
519  	 * Entry parameters set up way early. Yaffs sets up the rest.
520  	 * The structure should be zeroed out before use so that unused
521  	 * and defualt values are zero.
522  	 */
523  
524  	int inband_tags;	/* Use unband tags */
525  	u32 total_bytes_per_chunk;	/* Should be >= 512, does not need to
526  					 be a power of 2 */
527  	int chunks_per_block;	/* does not need to be a power of 2 */
528  	int spare_bytes_per_chunk;	/* spare area size */
529  	int start_block;	/* Start block we're allowed to use */
530  	int end_block;		/* End block we're allowed to use */
531  	int n_reserved_blocks;	/* Tuneable so that we can reduce
532  				 * reserved blocks on NOR and RAM. */
533  
534  	int n_caches;		/* If <= 0, then short op caching is disabled,
535  				 * else the number of short op caches.
536  				 */
537  	int use_nand_ecc;	/* Flag to decide whether or not to use
538  				 * NAND driver ECC on data (yaffs1) */
539  	int tags_9bytes;	/* Use 9 byte tags */
540  	int no_tags_ecc;	/* Flag to decide whether or not to do ECC
541  				 * on packed tags (yaffs2) */
542  
543  	int is_yaffs2;		/* Use yaffs2 mode on this device */
544  
545  	int empty_lost_n_found;	/* Auto-empty lost+found directory on mount */
546  
547  	int refresh_period;	/* How often to check for a block refresh */
548  
549  	/* Checkpoint control. Can be set before or after initialisation */
550  	u8 skip_checkpt_rd;
551  	u8 skip_checkpt_wr;
552  
553  	int enable_xattr;	/* Enable xattribs */
554  
555  	/* NAND access functions (Must be set before calling YAFFS) */
556  
557  	int (*write_chunk_fn) (struct yaffs_dev *dev,
558  			       int nand_chunk, const u8 *data,
559  			       const struct yaffs_spare *spare);
560  	int (*read_chunk_fn) (struct yaffs_dev *dev,
561  			      int nand_chunk, u8 *data,
562  			      struct yaffs_spare *spare);
563  	int (*erase_fn) (struct yaffs_dev *dev, int flash_block);
564  	int (*initialise_flash_fn) (struct yaffs_dev *dev);
565  	int (*deinitialise_flash_fn) (struct yaffs_dev *dev);
566  
567  	/* yaffs2 mode functions */
568  	int (*write_chunk_tags_fn) (struct yaffs_dev *dev,
569  				    int nand_chunk, const u8 *data,
570  				    const struct yaffs_ext_tags *tags);
571  	int (*read_chunk_tags_fn) (struct yaffs_dev *dev,
572  				   int nand_chunk, u8 *data,
573  				   struct yaffs_ext_tags *tags);
574  	int (*bad_block_fn) (struct yaffs_dev *dev, int block_no);
575  	int (*query_block_fn) (struct yaffs_dev *dev, int block_no,
576  			       enum yaffs_block_state *state,
577  			       u32 *seq_number);
578  
579  	/* The remove_obj_fn function must be supplied by OS flavours that
580  	 * need it.
581  	 * yaffs direct uses it to implement the faster readdir.
582  	 * Linux uses it to protect the directory during unlocking.
583  	 */
584  	void (*remove_obj_fn) (struct yaffs_obj *obj);
585  
586  	/* Callback to mark the superblock dirty */
587  	void (*sb_dirty_fn) (struct yaffs_dev *dev);
588  
589  	/*  Callback to control garbage collection. */
590  	unsigned (*gc_control) (struct yaffs_dev *dev);
591  
592  	/* Debug control flags. Don't use unless you know what you're doing */
593  	int use_header_file_size;	/* Flag to determine if we should use
594  					 * file sizes from the header */
595  	int disable_lazy_load;	/* Disable lazy loading on this device */
596  	int wide_tnodes_disabled;	/* Set to disable wide tnodes */
597  	int disable_soft_del;	/* yaffs 1 only: Set to disable the use of
598  				 * softdeletion. */
599  
600  	int defered_dir_update;	/* Set to defer directory updates */
601  
602  #ifdef CONFIG_YAFFS_AUTO_UNICODE
603  	int auto_unicode;
604  #endif
605  	int always_check_erased;	/* Force chunk erased check always on */
606  
607  	int disable_summary;
608  
609  	int max_objects;	/*
610  				 * Set to limit the number of objects created.
611  				 * 0 = no limit.
612  				*/
613  };
614  
615  struct yaffs_dev {
616  	struct yaffs_param param;
617  
618  	/* Context storage. Holds extra OS specific data for this device */
619  
620  	void *os_context;
621  	void *driver_context;
622  
623  	struct list_head dev_list;
624  
625  	/* Runtime parameters. Set up by YAFFS. */
626  	int data_bytes_per_chunk;
627  
628  	/* Non-wide tnode stuff */
629  	u16 chunk_grp_bits;	/* Number of bits that need to be resolved if
630  				 * the tnodes are not wide enough.
631  				 */
632  	u16 chunk_grp_size;	/* == 2^^chunk_grp_bits */
633  
634  	/* Stuff to support wide tnodes */
635  	u32 tnode_width;
636  	u32 tnode_mask;
637  	u32 tnode_size;
638  
639  	/* Stuff for figuring out file offset to chunk conversions */
640  	u32 chunk_shift;	/* Shift value */
641  	u32 chunk_div;		/* Divisor after shifting: 1 for 2^n sizes */
642  	u32 chunk_mask;		/* Mask to use for power-of-2 case */
643  
644  	int is_mounted;
645  	int read_only;
646  	int is_checkpointed;
647  
648  	/* Stuff to support block offsetting to support start block zero */
649  	int internal_start_block;
650  	int internal_end_block;
651  	int block_offset;
652  	int chunk_offset;
653  
654  	/* Runtime checkpointing stuff */
655  	int checkpt_page_seq;	/* running sequence number of checkpt pages */
656  	int checkpt_byte_count;
657  	int checkpt_byte_offs;
658  	u8 *checkpt_buffer;
659  	int checkpt_open_write;
660  	int blocks_in_checkpt;
661  	int checkpt_cur_chunk;
662  	int checkpt_cur_block;
663  	int checkpt_next_block;
664  	int *checkpt_block_list;
665  	int checkpt_max_blocks;
666  	u32 checkpt_sum;
667  	u32 checkpt_xor;
668  
669  	int checkpoint_blocks_required;	/* Number of blocks needed to store
670  					 * current checkpoint set */
671  
672  	/* Block Info */
673  	struct yaffs_block_info *block_info;
674  	u8 *chunk_bits;		/* bitmap of chunks in use */
675  	unsigned block_info_alt:1;	/* allocated using alternative alloc */
676  	unsigned chunk_bits_alt:1;	/* allocated using alternative alloc */
677  	int chunk_bit_stride;	/* Number of bytes of chunk_bits per block.
678  				 * Must be consistent with chunks_per_block.
679  				 */
680  
681  	int n_erased_blocks;
682  	int alloc_block;	/* Current block being allocated off */
683  	u32 alloc_page;
684  	int alloc_block_finder;	/* Used to search for next allocation block */
685  
686  	/* Object and Tnode memory management */
687  	void *allocator;
688  	int n_obj;
689  	int n_tnodes;
690  
691  	int n_hardlinks;
692  
693  	struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
694  	u32 bucket_finder;
695  
696  	int n_free_chunks;
697  
698  	/* Garbage collection control */
699  	u32 *gc_cleanup_list;	/* objects to delete at the end of a GC. */
700  	u32 n_clean_ups;
701  
702  	unsigned has_pending_prioritised_gc;	/* We think this device might
703  						have pending prioritised gcs */
704  	unsigned gc_disable;
705  	unsigned gc_block_finder;
706  	unsigned gc_dirtiest;
707  	unsigned gc_pages_in_use;
708  	unsigned gc_not_done;
709  	unsigned gc_block;
710  	unsigned gc_chunk;
711  	unsigned gc_skip;
712  	struct yaffs_summary_tags *gc_sum_tags;
713  
714  	/* Special directories */
715  	struct yaffs_obj *root_dir;
716  	struct yaffs_obj *lost_n_found;
717  
718  	int buffered_block;	/* Which block is buffered here? */
719  	int doing_buffered_block_rewrite;
720  
721  	struct yaffs_cache *cache;
722  	int cache_last_use;
723  
724  	/* Stuff for background deletion and unlinked files. */
725  	struct yaffs_obj *unlinked_dir;	/* Directory where unlinked and deleted
726  					 files live. */
727  	struct yaffs_obj *del_dir;	/* Directory where deleted objects are
728  					sent to disappear. */
729  	struct yaffs_obj *unlinked_deletion;	/* Current file being
730  							background deleted. */
731  	int n_deleted_files;	/* Count of files awaiting deletion; */
732  	int n_unlinked_files;	/* Count of unlinked files. */
733  	int n_bg_deletions;	/* Count of background deletions. */
734  
735  	/* Temporary buffer management */
736  	struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
737  	int max_temp;
738  	int temp_in_use;
739  	int unmanaged_buffer_allocs;
740  	int unmanaged_buffer_deallocs;
741  
742  	/* yaffs2 runtime stuff */
743  	unsigned seq_number;	/* Sequence number of currently
744  					allocating block */
745  	unsigned oldest_dirty_seq;
746  	unsigned oldest_dirty_block;
747  
748  	/* Block refreshing */
749  	int refresh_skip;	/* A skip down counter.
750  				 * Refresh happens when this gets to zero. */
751  
752  	/* Dirty directory handling */
753  	struct list_head dirty_dirs;	/* List of dirty directories */
754  
755  	/* Summary */
756  	int chunks_per_summary;
757  	struct yaffs_summary_tags *sum_tags;
758  
759  	/* Statistics */
760  	u32 n_page_writes;
761  	u32 n_page_reads;
762  	u32 n_erasures;
763  	u32 n_erase_failures;
764  	u32 n_gc_copies;
765  	u32 all_gcs;
766  	u32 passive_gc_count;
767  	u32 oldest_dirty_gc_count;
768  	u32 n_gc_blocks;
769  	u32 bg_gcs;
770  	u32 n_retried_writes;
771  	u32 n_retired_blocks;
772  	u32 n_ecc_fixed;
773  	u32 n_ecc_unfixed;
774  	u32 n_tags_ecc_fixed;
775  	u32 n_tags_ecc_unfixed;
776  	u32 n_deletions;
777  	u32 n_unmarked_deletions;
778  	u32 refresh_count;
779  	u32 cache_hits;
780  	u32 tags_used;
781  	u32 summary_used;
782  
783  };
784  
785  /* The CheckpointDevice structure holds the device information that changes
786   *at runtime and must be preserved over unmount/mount cycles.
787   */
788  struct yaffs_checkpt_dev {
789  	int struct_type;
790  	int n_erased_blocks;
791  	int alloc_block;	/* Current block being allocated off */
792  	u32 alloc_page;
793  	int n_free_chunks;
794  
795  	int n_deleted_files;	/* Count of files awaiting deletion; */
796  	int n_unlinked_files;	/* Count of unlinked files. */
797  	int n_bg_deletions;	/* Count of background deletions. */
798  
799  	/* yaffs2 runtime stuff */
800  	unsigned seq_number;	/* Sequence number of currently
801  				 * allocating block */
802  
803  };
804  
805  struct yaffs_checkpt_validity {
806  	int struct_type;
807  	u32 magic;
808  	u32 version;
809  	u32 head;
810  };
811  
812  struct yaffs_shadow_fixer {
813  	int obj_id;
814  	int shadowed_id;
815  	struct yaffs_shadow_fixer *next;
816  };
817  
818  /* Structure for doing xattr modifications */
819  struct yaffs_xattr_mod {
820  	int set;		/* If 0 then this is a deletion */
821  	const YCHAR *name;
822  	const void *data;
823  	int size;
824  	int flags;
825  	int result;
826  };
827  
828  /*----------------------- YAFFS Functions -----------------------*/
829  
830  int yaffs_guts_initialise(struct yaffs_dev *dev);
831  void yaffs_deinitialise(struct yaffs_dev *dev);
832  
833  int yaffs_get_n_free_chunks(struct yaffs_dev *dev);
834  
835  int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
836  		     struct yaffs_obj *new_dir, const YCHAR * new_name);
837  
838  int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
839  int yaffs_del_obj(struct yaffs_obj *obj);
840  
841  int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
842  loff_t yaffs_get_obj_length(struct yaffs_obj *obj);
843  int yaffs_get_obj_inode(struct yaffs_obj *obj);
844  unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
845  int yaffs_get_obj_link_count(struct yaffs_obj *obj);
846  
847  /* File operations */
848  int yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, loff_t offset,
849  		  int n_bytes);
850  int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, loff_t offset,
851  		  int n_bytes, int write_trhrough);
852  int yaffs_resize_file(struct yaffs_obj *obj, loff_t new_size);
853  
854  struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
855  				    const YCHAR *name, u32 mode, u32 uid,
856  				    u32 gid);
857  
858  int yaffs_flush_file(struct yaffs_obj *obj, int update_time, int data_sync);
859  
860  /* Flushing and checkpointing */
861  void yaffs_flush_whole_cache(struct yaffs_dev *dev);
862  
863  int yaffs_checkpoint_save(struct yaffs_dev *dev);
864  int yaffs_checkpoint_restore(struct yaffs_dev *dev);
865  
866  /* Directory operations */
867  struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
868  				   u32 mode, u32 uid, u32 gid);
869  struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
870  				     const YCHAR *name);
871  struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);
872  
873  /* Link operations */
874  struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR *name,
875  				 struct yaffs_obj *equiv_obj);
876  
877  struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);
878  
879  /* Symlink operations */
880  struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
881  				       const YCHAR *name, u32 mode, u32 uid,
882  				       u32 gid, const YCHAR *alias);
883  YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);
884  
885  /* Special inodes (fifos, sockets and devices) */
886  struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
887  				       const YCHAR *name, u32 mode, u32 uid,
888  				       u32 gid, u32 rdev);
889  
890  int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR *name,
891  		      const void *value, int size, int flags);
892  int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR *name, void *value,
893  		      int size);
894  int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
895  int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR *name);
896  
897  /* Special directories */
898  struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
899  struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);
900  
901  void yaffs_handle_defered_free(struct yaffs_obj *obj);
902  
903  void yaffs_update_dirty_dirs(struct yaffs_dev *dev);
904  
905  int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);
906  
907  /* Debug dump  */
908  int yaffs_dump_obj(struct yaffs_obj *obj);
909  
910  void yaffs_guts_test(struct yaffs_dev *dev);
911  
912  /* A few useful functions to be used within the core files*/
913  void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
914  		     int lyn);
915  int yaffs_check_ff(u8 *buffer, int n_bytes);
916  void yaffs_handle_chunk_error(struct yaffs_dev *dev,
917  			      struct yaffs_block_info *bi);
918  
919  u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev);
920  void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer);
921  
922  struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
923  						 int number,
924  						 enum yaffs_obj_type type);
925  int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
926  			    int nand_chunk, int in_scan);
927  void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR *name);
928  void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
929  				const struct yaffs_obj_hdr *oh);
930  void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
931  YCHAR *yaffs_clone_str(const YCHAR *str);
932  void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list);
933  void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
934  int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name,
935  		    int force, int is_shrink, int shadows,
936  		    struct yaffs_xattr_mod *xop);
937  void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
938  			       int backward_scanning);
939  int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
940  struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
941  struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
942  					   struct yaffs_file_var *file_struct,
943  					   u32 chunk_id,
944  					   struct yaffs_tnode *passed_tn);
945  
946  int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
947  		     int n_bytes, int write_trhrough);
948  void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size);
949  void yaffs_skip_rest_of_block(struct yaffs_dev *dev);
950  
951  int yaffs_count_free_chunks(struct yaffs_dev *dev);
952  
953  struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
954  				       struct yaffs_file_var *file_struct,
955  				       u32 chunk_id);
956  
957  u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
958  			 unsigned pos);
959  
960  int yaffs_is_non_empty_dir(struct yaffs_obj *obj);
961  
962  void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
963  				int *chunk_out, u32 *offset_out);
964  /*
965   * Marshalling functions to get loff_t file sizes into aand out of
966   * object headers.
967   */
968  void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize);
969  loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh);
970  loff_t yaffs_max_file_size(struct yaffs_dev *dev);
971  
972  
973  #endif
974