xref: /openbmc/u-boot/fs/yaffs2/yaffs_guts.h (revision dd1033e4)
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