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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 around 512Gbytees 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 #define YAFFS_MAX_FILE_SIZE_32		0x7fffffff
58 
59 /* Constants for YAFFS1 mode */
60 #define YAFFS_BYTES_PER_SPARE		16
61 #define YAFFS_BYTES_PER_CHUNK		512
62 #define YAFFS_CHUNK_SIZE_SHIFT		9
63 #define YAFFS_CHUNKS_PER_BLOCK		32
64 #define YAFFS_BYTES_PER_BLOCK	(YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
65 
66 #define YAFFS_MIN_YAFFS2_CHUNK_SIZE	1024
67 #define YAFFS_MIN_YAFFS2_SPARE_SIZE	32
68 
69 
70 
71 #define YAFFS_ALLOCATION_NOBJECTS	100
72 #define YAFFS_ALLOCATION_NTNODES	100
73 #define YAFFS_ALLOCATION_NLINKS		100
74 
75 #define YAFFS_NOBJECT_BUCKETS		256
76 
77 #define YAFFS_OBJECT_SPACE		0x40000
78 #define YAFFS_MAX_OBJECT_ID		(YAFFS_OBJECT_SPACE - 1)
79 
80 /* Binary data version stamps */
81 #define YAFFS_SUMMARY_VERSION		1
82 #define YAFFS_CHECKPOINT_VERSION	7
83 
84 #ifdef CONFIG_YAFFS_UNICODE
85 #define YAFFS_MAX_NAME_LENGTH		127
86 #define YAFFS_MAX_ALIAS_LENGTH		79
87 #else
88 #define YAFFS_MAX_NAME_LENGTH		255
89 #define YAFFS_MAX_ALIAS_LENGTH		159
90 #endif
91 
92 #define YAFFS_SHORT_NAME_LENGTH		15
93 
94 /* Some special object ids for pseudo objects */
95 #define YAFFS_OBJECTID_ROOT		1
96 #define YAFFS_OBJECTID_LOSTNFOUND	2
97 #define YAFFS_OBJECTID_UNLINKED		3
98 #define YAFFS_OBJECTID_DELETED		4
99 
100 /* Fake object Id for summary data */
101 #define YAFFS_OBJECTID_SUMMARY		0x10
102 
103 /* Pseudo object ids for checkpointing */
104 #define YAFFS_OBJECTID_CHECKPOINT_DATA	0x20
105 #define YAFFS_SEQUENCE_CHECKPOINT_DATA	0x21
106 
107 #define YAFFS_MAX_SHORT_OP_CACHES	20
108 
109 #define YAFFS_N_TEMP_BUFFERS		6
110 
111 /* We limit the number attempts at sucessfully saving a chunk of data.
112  * Small-page devices have 32 pages per block; large-page devices have 64.
113  * Default to something in the order of 5 to 10 blocks worth of chunks.
114  */
115 #define YAFFS_WR_ATTEMPTS		(5*64)
116 
117 /* Sequence numbers are used in YAFFS2 to determine block allocation order.
118  * The range is limited slightly to help distinguish bad numbers from good.
119  * This also allows us to perhaps in the future use special numbers for
120  * special purposes.
121  * EFFFFF00 allows the allocation of 8 blocks/second (~1Mbytes) for 15 years,
122  * and is a larger number than the lifetime of a 2GB device.
123  */
124 #define YAFFS_LOWEST_SEQUENCE_NUMBER	0x00001000
125 #define YAFFS_HIGHEST_SEQUENCE_NUMBER	0xefffff00
126 
127 /* Special sequence number for bad block that failed to be marked bad */
128 #define YAFFS_SEQUENCE_BAD_BLOCK	0xffff0000
129 
130 /* ChunkCache is used for short read/write operations.*/
131 struct yaffs_cache {
132 	struct yaffs_obj *object;
133 	int chunk_id;
134 	int last_use;
135 	int dirty;
136 	int n_bytes;		/* Only valid if the cache is dirty */
137 	int locked;		/* Can't push out or flush while locked. */
138 	u8 *data;
139 };
140 
141 /* yaffs1 tags structures in RAM
142  * NB This uses bitfield. Bitfields should not straddle a u32 boundary
143  * otherwise the structure size will get blown out.
144  */
145 
146 struct yaffs_tags {
147 	unsigned chunk_id:20;
148 	unsigned serial_number:2;
149 	unsigned n_bytes_lsb:10;
150 	unsigned obj_id:18;
151 	unsigned ecc:12;
152 	unsigned n_bytes_msb:2;
153 };
154 
155 union yaffs_tags_union {
156 	struct yaffs_tags as_tags;
157 	u8 as_bytes[8];
158 };
159 
160 
161 /* Stuff used for extended tags in YAFFS2 */
162 
163 enum yaffs_ecc_result {
164 	YAFFS_ECC_RESULT_UNKNOWN,
165 	YAFFS_ECC_RESULT_NO_ERROR,
166 	YAFFS_ECC_RESULT_FIXED,
167 	YAFFS_ECC_RESULT_UNFIXED
168 };
169 
170 enum yaffs_obj_type {
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
177 };
178 
179 #define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
180 
181 struct yaffs_ext_tags {
182 	unsigned chunk_used;	/*  Status of the chunk: used or unused */
183 	unsigned obj_id;	/* If 0 this is not used */
184 	unsigned chunk_id;	/* If 0 this is a header, else a data chunk */
185 	unsigned n_bytes;	/* Only valid for data chunks */
186 
187 	/* The following stuff only has meaning when we read */
188 	enum yaffs_ecc_result ecc_result;
189 	unsigned block_bad;
190 
191 	/* YAFFS 1 stuff */
192 	unsigned is_deleted;	/* The chunk is marked deleted */
193 	unsigned serial_number;	/* Yaffs1 2-bit serial number */
194 
195 	/* YAFFS2 stuff */
196 	unsigned seq_number;	/* The sequence number of this block */
197 
198 	/* Extra info if this is an object header (YAFFS2 only) */
199 
200 	unsigned extra_available;	/* Extra info available if not zero */
201 	unsigned extra_parent_id;	/* The parent object */
202 	unsigned extra_is_shrink;	/* Is it a shrink header? */
203 	unsigned extra_shadows;	/* Does this shadow another object? */
204 
205 	enum yaffs_obj_type extra_obj_type;	/* What object type? */
206 
207 	loff_t extra_file_size;		/* Length if it is a file */
208 	unsigned extra_equiv_id;	/* Equivalent object for a hard link */
209 };
210 
211 /* Spare structure for YAFFS1 */
212 struct yaffs_spare {
213 	u8 tb0;
214 	u8 tb1;
215 	u8 tb2;
216 	u8 tb3;
217 	u8 page_status;		/* set to 0 to delete the chunk */
218 	u8 block_status;
219 	u8 tb4;
220 	u8 tb5;
221 	u8 ecc1[3];
222 	u8 tb6;
223 	u8 tb7;
224 	u8 ecc2[3];
225 };
226 
227 /*Special structure for passing through to mtd */
228 struct yaffs_nand_spare {
229 	struct yaffs_spare spare;
230 	int eccres1;
231 	int eccres2;
232 };
233 
234 /* Block data in RAM */
235 
236 enum yaffs_block_state {
237 	YAFFS_BLOCK_STATE_UNKNOWN = 0,
238 
239 	YAFFS_BLOCK_STATE_SCANNING,
240 	/* Being scanned */
241 
242 	YAFFS_BLOCK_STATE_NEEDS_SCAN,
243 	/* The block might have something on it (ie it is allocating or full,
244 	 * perhaps empty) but it needs to be scanned to determine its true
245 	 * state.
246 	 * This state is only valid during scanning.
247 	 * NB We tolerate empty because the pre-scanner might be incapable of
248 	 * deciding
249 	 * However, if this state is returned on a YAFFS2 device,
250 	 * then we expect a sequence number
251 	 */
252 
253 	YAFFS_BLOCK_STATE_EMPTY,
254 	/* This block is empty */
255 
256 	YAFFS_BLOCK_STATE_ALLOCATING,
257 	/* This block is partially allocated.
258 	 * At least one page holds valid data.
259 	 * This is the one currently being used for page
260 	 * allocation. Should never be more than one of these.
261 	 * If a block is only partially allocated at mount it is treated as
262 	 * full.
263 	 */
264 
265 	YAFFS_BLOCK_STATE_FULL,
266 	/* All the pages in this block have been allocated.
267 	 * If a block was only partially allocated when mounted we treat
268 	 * it as fully allocated.
269 	 */
270 
271 	YAFFS_BLOCK_STATE_DIRTY,
272 	/* The block was full and now all chunks have been deleted.
273 	 * Erase me, reuse me.
274 	 */
275 
276 	YAFFS_BLOCK_STATE_CHECKPOINT,
277 	/* This block is assigned to holding checkpoint data. */
278 
279 	YAFFS_BLOCK_STATE_COLLECTING,
280 	/* This block is being garbage collected */
281 
282 	YAFFS_BLOCK_STATE_DEAD
283 	    /* This block has failed and is not in use */
284 };
285 
286 #define	YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
287 
288 struct yaffs_block_info {
289 
290 	int soft_del_pages:10;	/* number of soft deleted pages */
291 	int pages_in_use:10;	/* number of pages in use */
292 	unsigned block_state:4;	/* One of the above block states. */
293 				/* NB use unsigned because enum is sometimes
294 				 * an int */
295 	u32 needs_retiring:1;	/* Data has failed on this block, */
296 				/*need to get valid data off and retire*/
297 	u32 skip_erased_check:1;/* Skip the erased check on this block */
298 	u32 gc_prioritise:1;	/* An ECC check or blank check has failed.
299 				   Block should be prioritised for GC */
300 	u32 chunk_error_strikes:3;	/* How many times we've had ecc etc
301 				failures on this block and tried to reuse it */
302 	u32 has_summary:1;	/* The block has a summary */
303 
304 	u32 has_shrink_hdr:1;	/* This block has at least one shrink header */
305 	u32 seq_number;		/* block sequence number for yaffs2 */
306 
307 };
308 
309 /* -------------------------- Object structure -------------------------------*/
310 /* This is the object structure as stored on NAND */
311 
312 struct yaffs_obj_hdr {
313 	enum yaffs_obj_type type;
314 
315 	/* Apply to everything  */
316 	int parent_obj_id;
317 	u16 sum_no_longer_used;	/* checksum of name. No longer used */
318 	YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
319 
320 	/* The following apply to all object types except for hard links */
321 	u32 yst_mode;		/* protection */
322 
323 	u32 yst_uid;
324 	u32 yst_gid;
325 	u32 yst_atime;
326 	u32 yst_mtime;
327 	u32 yst_ctime;
328 
329 	/* File size  applies to files only */
330 	u32 file_size_low;
331 
332 	/* Equivalent object id applies to hard links only. */
333 	int equiv_id;
334 
335 	/* Alias is for symlinks only. */
336 	YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
337 
338 	u32 yst_rdev;	/* stuff for block and char devices (major/min) */
339 
340 	u32 win_ctime[2];
341 	u32 win_atime[2];
342 	u32 win_mtime[2];
343 
344 	u32 inband_shadowed_obj_id;
345 	u32 inband_is_shrink;
346 
347 	u32 file_size_high;
348 	u32 reserved[1];
349 	int shadows_obj;	/* This object header shadows the
350 				specified object if > 0 */
351 
352 	/* is_shrink applies to object headers written when wemake a hole. */
353 	u32 is_shrink;
354 
355 };
356 
357 /*--------------------------- Tnode -------------------------- */
358 
359 struct yaffs_tnode {
360 	struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
361 };
362 
363 /*------------------------  Object -----------------------------*/
364 /* An object can be one of:
365  * - a directory (no data, has children links
366  * - a regular file (data.... not prunes :->).
367  * - a symlink [symbolic link] (the alias).
368  * - a hard link
369  */
370 
371 struct yaffs_file_var {
372 	loff_t file_size;
373 	loff_t scanned_size;
374 	loff_t shrink_size;
375 	int top_level;
376 	struct yaffs_tnode *top;
377 };
378 
379 struct yaffs_dir_var {
380 	struct list_head children;	/* list of child links */
381 	struct list_head dirty;	/* Entry for list of dirty directories */
382 };
383 
384 struct yaffs_symlink_var {
385 	YCHAR *alias;
386 };
387 
388 struct yaffs_hardlink_var {
389 	struct yaffs_obj *equiv_obj;
390 	u32 equiv_id;
391 };
392 
393 union yaffs_obj_var {
394 	struct yaffs_file_var file_variant;
395 	struct yaffs_dir_var dir_variant;
396 	struct yaffs_symlink_var symlink_variant;
397 	struct yaffs_hardlink_var hardlink_variant;
398 };
399 
400 struct yaffs_obj {
401 	u8 deleted:1;		/* This should only apply to unlinked files. */
402 	u8 soft_del:1;		/* it has also been soft deleted */
403 	u8 unlinked:1;		/* An unlinked file.*/
404 	u8 fake:1;		/* A fake object has no presence on NAND. */
405 	u8 rename_allowed:1;	/* Some objects cannot be renamed. */
406 	u8 unlink_allowed:1;
407 	u8 dirty:1;		/* the object needs to be written to flash */
408 	u8 valid:1;		/* When the file system is being loaded up, this
409 				 * object might be created before the data
410 				 * is available
411 				 * ie. file data chunks encountered before
412 				* the header.
413 				 */
414 	u8 lazy_loaded:1;	/* This object has been lazy loaded and
415 				 * is missing some detail */
416 
417 	u8 defered_free:1;	/* Object is removed from NAND, but is
418 				 * still in the inode cache.
419 				 * Free of object is defered.
420 				 * until the inode is released.
421 				 */
422 	u8 being_created:1;	/* This object is still being created
423 				 * so skip some verification checks. */
424 	u8 is_shadowed:1;	/* This object is shadowed on the way
425 				 * to being renamed. */
426 
427 	u8 xattr_known:1;	/* We know if this has object has xattribs
428 				 * or not. */
429 	u8 has_xattr:1;		/* This object has xattribs.
430 				 * Only valid if xattr_known. */
431 
432 	u8 serial;		/* serial number of chunk in NAND.*/
433 	u16 sum;		/* sum of the name to speed searching */
434 
435 	struct yaffs_dev *my_dev;	/* The device I'm on */
436 
437 	struct list_head hash_link;	/* list of objects in hash bucket */
438 
439 	struct list_head hard_links;	/* hard linked object chain*/
440 
441 	/* directory structure stuff */
442 	/* also used for linking up the free list */
443 	struct yaffs_obj *parent;
444 	struct list_head siblings;
445 
446 	/* Where's my object header in NAND? */
447 	int hdr_chunk;
448 
449 	int n_data_chunks;	/* Number of data chunks for this file. */
450 
451 	u32 obj_id;		/* the object id value */
452 
453 	u32 yst_mode;
454 
455 	YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];
456 
457 #ifdef CONFIG_YAFFS_WINCE
458 	u32 win_ctime[2];
459 	u32 win_mtime[2];
460 	u32 win_atime[2];
461 #else
462 	u32 yst_uid;
463 	u32 yst_gid;
464 	u32 yst_atime;
465 	u32 yst_mtime;
466 	u32 yst_ctime;
467 #endif
468 
469 	u32 yst_rdev;
470 
471 	void *my_inode;
472 
473 	enum yaffs_obj_type variant_type;
474 
475 	union yaffs_obj_var variant;
476 
477 };
478 
479 struct yaffs_obj_bucket {
480 	struct list_head list;
481 	int count;
482 };
483 
484 /* yaffs_checkpt_obj holds the definition of an object as dumped
485  * by checkpointing.
486  */
487 
488 struct yaffs_checkpt_obj {
489 	int struct_type;
490 	u32 obj_id;
491 	u32 parent_id;
492 	int hdr_chunk;
493 	enum yaffs_obj_type variant_type:3;
494 	u8 deleted:1;
495 	u8 soft_del:1;
496 	u8 unlinked:1;
497 	u8 fake:1;
498 	u8 rename_allowed:1;
499 	u8 unlink_allowed:1;
500 	u8 serial;
501 	int n_data_chunks;
502 	loff_t size_or_equiv_obj;
503 };
504 
505 /*--------------------- Temporary buffers ----------------
506  *
507  * These are chunk-sized working buffers. Each device has a few.
508  */
509 
510 struct yaffs_buffer {
511 	u8 *buffer;
512 	int in_use;
513 };
514 
515 /*----------------- Device ---------------------------------*/
516 
517 struct yaffs_param {
518 	const YCHAR *name;
519 
520 	/*
521 	 * Entry parameters set up way early. Yaffs sets up the rest.
522 	 * The structure should be zeroed out before use so that unused
523 	 * and default values are zero.
524 	 */
525 
526 	int inband_tags;	/* Use unband tags */
527 	u32 total_bytes_per_chunk;	/* Should be >= 512, does not need to
528 					 be a power of 2 */
529 	int chunks_per_block;	/* does not need to be a power of 2 */
530 	int spare_bytes_per_chunk;	/* spare area size */
531 	int start_block;	/* Start block we're allowed to use */
532 	int end_block;		/* End block we're allowed to use */
533 	int n_reserved_blocks;	/* Tuneable so that we can reduce
534 				 * reserved blocks on NOR and RAM. */
535 
536 	int n_caches;		/* If <= 0, then short op caching is disabled,
537 				 * else the number of short op caches.
538 				 */
539 	int cache_bypass_aligned; /* If non-zero then bypass the cache for
540 				   * aligned writes.
541 				   */
542 
543 	int use_nand_ecc;	/* Flag to decide whether or not to use
544 				 * NAND driver ECC on data (yaffs1) */
545 	int tags_9bytes;	/* Use 9 byte tags */
546 	int no_tags_ecc;	/* Flag to decide whether or not to do ECC
547 				 * on packed tags (yaffs2) */
548 
549 	int is_yaffs2;		/* Use yaffs2 mode on this device */
550 
551 	int empty_lost_n_found;	/* Auto-empty lost+found directory on mount */
552 
553 	int refresh_period;	/* How often to check for a block refresh */
554 
555 	/* Checkpoint control. Can be set before or after initialisation */
556 	u8 skip_checkpt_rd;
557 	u8 skip_checkpt_wr;
558 
559 	int enable_xattr;	/* Enable xattribs */
560 
561 	int max_objects;	/*
562 				 * Set to limit the number of objects created.
563 				 * 0 = no limit.
564 				*/
565 
566 	/* The remove_obj_fn function must be supplied by OS flavours that
567 	 * need it.
568 	 * yaffs direct uses it to implement the faster readdir.
569 	 * Linux uses it to protect the directory during unlocking.
570 	 */
571 	void (*remove_obj_fn) (struct yaffs_obj *obj);
572 
573 	/* Callback to mark the superblock dirty */
574 	void (*sb_dirty_fn) (struct yaffs_dev *dev);
575 
576 	/*  Callback to control garbage collection. */
577 	unsigned (*gc_control_fn) (struct yaffs_dev *dev);
578 
579 	/* Debug control flags. Don't use unless you know what you're doing */
580 	int use_header_file_size;	/* Flag to determine if we should use
581 					 * file sizes from the header */
582 	int disable_lazy_load;	/* Disable lazy loading on this device */
583 	int wide_tnodes_disabled;	/* Set to disable wide tnodes */
584 	int disable_soft_del;	/* yaffs 1 only: Set to disable the use of
585 				 * softdeletion. */
586 
587 	int defered_dir_update;	/* Set to defer directory updates */
588 
589 #ifdef CONFIG_YAFFS_AUTO_UNICODE
590 	int auto_unicode;
591 #endif
592 	int always_check_erased;	/* Force chunk erased check always on */
593 
594 	int disable_summary;
595 
596 };
597 
598 struct yaffs_driver {
599 	int (*drv_write_chunk_fn) (struct yaffs_dev *dev, int nand_chunk,
600 				   const u8 *data, int data_len,
601 				   const u8 *oob, int oob_len);
602 	int (*drv_read_chunk_fn) (struct yaffs_dev *dev, int nand_chunk,
603 				   u8 *data, int data_len,
604 				   u8 *oob, int oob_len,
605 				   enum yaffs_ecc_result *ecc_result);
606 	int (*drv_erase_fn) (struct yaffs_dev *dev, int block_no);
607 	int (*drv_mark_bad_fn) (struct yaffs_dev *dev, int block_no);
608 	int (*drv_check_bad_fn) (struct yaffs_dev *dev, int block_no);
609 	int (*drv_initialise_fn) (struct yaffs_dev *dev);
610 	int (*drv_deinitialise_fn) (struct yaffs_dev *dev);
611 };
612 
613 struct yaffs_tags_handler {
614 	int (*write_chunk_tags_fn) (struct yaffs_dev *dev,
615 				    int nand_chunk, const u8 *data,
616 				    const struct yaffs_ext_tags *tags);
617 	int (*read_chunk_tags_fn) (struct yaffs_dev *dev,
618 				   int nand_chunk, u8 *data,
619 				   struct yaffs_ext_tags *tags);
620 
621 	int (*query_block_fn) (struct yaffs_dev *dev, int block_no,
622 			       enum yaffs_block_state *state,
623 			       u32 *seq_number);
624 	int (*mark_bad_fn) (struct yaffs_dev *dev, int block_no);
625 };
626 
627 struct yaffs_dev {
628 	struct yaffs_param param;
629 	struct yaffs_driver drv;
630 	struct yaffs_tags_handler tagger;
631 
632 	/* Context storage. Holds extra OS specific data for this device */
633 
634 	void *os_context;
635 	void *driver_context;
636 
637 	struct list_head dev_list;
638 
639 	/* Runtime parameters. Set up by YAFFS. */
640 	int data_bytes_per_chunk;
641 
642 	/* Non-wide tnode stuff */
643 	u16 chunk_grp_bits;	/* Number of bits that need to be resolved if
644 				 * the tnodes are not wide enough.
645 				 */
646 	u16 chunk_grp_size;	/* == 2^^chunk_grp_bits */
647 
648 	/* Stuff to support wide tnodes */
649 	u32 tnode_width;
650 	u32 tnode_mask;
651 	u32 tnode_size;
652 
653 	/* Stuff for figuring out file offset to chunk conversions */
654 	u32 chunk_shift;	/* Shift value */
655 	u32 chunk_div;		/* Divisor after shifting: 1 for 2^n sizes */
656 	u32 chunk_mask;		/* Mask to use for power-of-2 case */
657 
658 	int is_mounted;
659 	int read_only;
660 	int is_checkpointed;
661 
662 	/* Stuff to support block offsetting to support start block zero */
663 	int internal_start_block;
664 	int internal_end_block;
665 	int block_offset;
666 	int chunk_offset;
667 
668 	/* Runtime checkpointing stuff */
669 	int checkpt_page_seq;	/* running sequence number of checkpt pages */
670 	int checkpt_byte_count;
671 	int checkpt_byte_offs;
672 	u8 *checkpt_buffer;
673 	int checkpt_open_write;
674 	int blocks_in_checkpt;
675 	int checkpt_cur_chunk;
676 	int checkpt_cur_block;
677 	int checkpt_next_block;
678 	int *checkpt_block_list;
679 	int checkpt_max_blocks;
680 	u32 checkpt_sum;
681 	u32 checkpt_xor;
682 
683 	int checkpoint_blocks_required;	/* Number of blocks needed to store
684 					 * current checkpoint set */
685 
686 	/* Block Info */
687 	struct yaffs_block_info *block_info;
688 	u8 *chunk_bits;		/* bitmap of chunks in use */
689 	unsigned block_info_alt:1;	/* allocated using alternative alloc */
690 	unsigned chunk_bits_alt:1;	/* allocated using alternative alloc */
691 	int chunk_bit_stride;	/* Number of bytes of chunk_bits per block.
692 				 * Must be consistent with chunks_per_block.
693 				 */
694 
695 	int n_erased_blocks;
696 	int alloc_block;	/* Current block being allocated off */
697 	u32 alloc_page;
698 	int alloc_block_finder;	/* Used to search for next allocation block */
699 
700 	/* Object and Tnode memory management */
701 	void *allocator;
702 	int n_obj;
703 	int n_tnodes;
704 
705 	int n_hardlinks;
706 
707 	struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
708 	u32 bucket_finder;
709 
710 	int n_free_chunks;
711 
712 	/* Garbage collection control */
713 	u32 *gc_cleanup_list;	/* objects to delete at the end of a GC. */
714 	u32 n_clean_ups;
715 
716 	unsigned has_pending_prioritised_gc;	/* We think this device might
717 						have pending prioritised gcs */
718 	unsigned gc_disable;
719 	unsigned gc_block_finder;
720 	unsigned gc_dirtiest;
721 	unsigned gc_pages_in_use;
722 	unsigned gc_not_done;
723 	unsigned gc_block;
724 	unsigned gc_chunk;
725 	unsigned gc_skip;
726 	struct yaffs_summary_tags *gc_sum_tags;
727 
728 	/* Special directories */
729 	struct yaffs_obj *root_dir;
730 	struct yaffs_obj *lost_n_found;
731 
732 	int buffered_block;	/* Which block is buffered here? */
733 	int doing_buffered_block_rewrite;
734 
735 	struct yaffs_cache *cache;
736 	int cache_last_use;
737 
738 	/* Stuff for background deletion and unlinked files. */
739 	struct yaffs_obj *unlinked_dir;	/* Directory where unlinked and deleted
740 					 files live. */
741 	struct yaffs_obj *del_dir;	/* Directory where deleted objects are
742 					sent to disappear. */
743 	struct yaffs_obj *unlinked_deletion;	/* Current file being
744 							background deleted. */
745 	int n_deleted_files;	/* Count of files awaiting deletion; */
746 	int n_unlinked_files;	/* Count of unlinked files. */
747 	int n_bg_deletions;	/* Count of background deletions. */
748 
749 	/* Temporary buffer management */
750 	struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
751 	int max_temp;
752 	int temp_in_use;
753 	int unmanaged_buffer_allocs;
754 	int unmanaged_buffer_deallocs;
755 
756 	/* yaffs2 runtime stuff */
757 	unsigned seq_number;	/* Sequence number of currently
758 					allocating block */
759 	unsigned oldest_dirty_seq;
760 	unsigned oldest_dirty_block;
761 
762 	/* Block refreshing */
763 	int refresh_skip;	/* A skip down counter.
764 				 * Refresh happens when this gets to zero. */
765 
766 	/* Dirty directory handling */
767 	struct list_head dirty_dirs;	/* List of dirty directories */
768 
769 	/* Summary */
770 	int chunks_per_summary;
771 	struct yaffs_summary_tags *sum_tags;
772 
773 	/* Statistics */
774 	u32 n_page_writes;
775 	u32 n_page_reads;
776 	u32 n_erasures;
777 	u32 n_bad_markings;
778 	u32 n_erase_failures;
779 	u32 n_gc_copies;
780 	u32 all_gcs;
781 	u32 passive_gc_count;
782 	u32 oldest_dirty_gc_count;
783 	u32 n_gc_blocks;
784 	u32 bg_gcs;
785 	u32 n_retried_writes;
786 	u32 n_retired_blocks;
787 	u32 n_ecc_fixed;
788 	u32 n_ecc_unfixed;
789 	u32 n_tags_ecc_fixed;
790 	u32 n_tags_ecc_unfixed;
791 	u32 n_deletions;
792 	u32 n_unmarked_deletions;
793 	u32 refresh_count;
794 	u32 cache_hits;
795 	u32 tags_used;
796 	u32 summary_used;
797 
798 };
799 
800 /* The CheckpointDevice structure holds the device information that changes
801  *at runtime and must be preserved over unmount/mount cycles.
802  */
803 struct yaffs_checkpt_dev {
804 	int struct_type;
805 	int n_erased_blocks;
806 	int alloc_block;	/* Current block being allocated off */
807 	u32 alloc_page;
808 	int n_free_chunks;
809 
810 	int n_deleted_files;	/* Count of files awaiting deletion; */
811 	int n_unlinked_files;	/* Count of unlinked files. */
812 	int n_bg_deletions;	/* Count of background deletions. */
813 
814 	/* yaffs2 runtime stuff */
815 	unsigned seq_number;	/* Sequence number of currently
816 				 * allocating block */
817 
818 };
819 
820 struct yaffs_checkpt_validity {
821 	int struct_type;
822 	u32 magic;
823 	u32 version;
824 	u32 head;
825 };
826 
827 struct yaffs_shadow_fixer {
828 	int obj_id;
829 	int shadowed_id;
830 	struct yaffs_shadow_fixer *next;
831 };
832 
833 /* Structure for doing xattr modifications */
834 struct yaffs_xattr_mod {
835 	int set;		/* If 0 then this is a deletion */
836 	const YCHAR *name;
837 	const void *data;
838 	int size;
839 	int flags;
840 	int result;
841 };
842 
843 /*----------------------- YAFFS Functions -----------------------*/
844 
845 int yaffs_guts_initialise(struct yaffs_dev *dev);
846 void yaffs_deinitialise(struct yaffs_dev *dev);
847 
848 int yaffs_get_n_free_chunks(struct yaffs_dev *dev);
849 
850 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
851 		     struct yaffs_obj *new_dir, const YCHAR * new_name);
852 
853 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
854 int yaffs_del_obj(struct yaffs_obj *obj);
855 
856 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
857 loff_t yaffs_get_obj_length(struct yaffs_obj *obj);
858 int yaffs_get_obj_inode(struct yaffs_obj *obj);
859 unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
860 int yaffs_get_obj_link_count(struct yaffs_obj *obj);
861 
862 /* File operations */
863 int yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, loff_t offset,
864 		  int n_bytes);
865 int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, loff_t offset,
866 		  int n_bytes, int write_trhrough);
867 int yaffs_resize_file(struct yaffs_obj *obj, loff_t new_size);
868 
869 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
870 				    const YCHAR *name, u32 mode, u32 uid,
871 				    u32 gid);
872 
873 int yaffs_flush_file(struct yaffs_obj *obj, int update_time, int data_sync);
874 
875 /* Flushing and checkpointing */
876 void yaffs_flush_whole_cache(struct yaffs_dev *dev);
877 
878 int yaffs_checkpoint_save(struct yaffs_dev *dev);
879 int yaffs_checkpoint_restore(struct yaffs_dev *dev);
880 
881 /* Directory operations */
882 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
883 				   u32 mode, u32 uid, u32 gid);
884 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
885 				     const YCHAR *name);
886 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);
887 
888 /* Link operations */
889 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR *name,
890 				 struct yaffs_obj *equiv_obj);
891 
892 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);
893 
894 /* Symlink operations */
895 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
896 				       const YCHAR *name, u32 mode, u32 uid,
897 				       u32 gid, const YCHAR *alias);
898 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);
899 
900 /* Special inodes (fifos, sockets and devices) */
901 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
902 				       const YCHAR *name, u32 mode, u32 uid,
903 				       u32 gid, u32 rdev);
904 
905 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR *name,
906 		      const void *value, int size, int flags);
907 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR *name, void *value,
908 		      int size);
909 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
910 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR *name);
911 
912 /* Special directories */
913 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
914 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);
915 
916 void yaffs_handle_defered_free(struct yaffs_obj *obj);
917 
918 void yaffs_update_dirty_dirs(struct yaffs_dev *dev);
919 
920 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);
921 
922 /* Debug dump  */
923 int yaffs_dump_obj(struct yaffs_obj *obj);
924 
925 void yaffs_guts_test(struct yaffs_dev *dev);
926 
927 /* A few useful functions to be used within the core files*/
928 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
929 		     int lyn);
930 int yaffs_check_ff(u8 *buffer, int n_bytes);
931 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
932 			      struct yaffs_block_info *bi);
933 
934 u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev);
935 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer);
936 
937 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
938 						 int number,
939 						 enum yaffs_obj_type type);
940 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
941 			    int nand_chunk, int in_scan);
942 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR *name);
943 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
944 				const struct yaffs_obj_hdr *oh);
945 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
946 YCHAR *yaffs_clone_str(const YCHAR *str);
947 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list);
948 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
949 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name,
950 		    int force, int is_shrink, int shadows,
951 		    struct yaffs_xattr_mod *xop);
952 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
953 			       int backward_scanning);
954 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
955 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
956 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
957 					   struct yaffs_file_var *file_struct,
958 					   u32 chunk_id,
959 					   struct yaffs_tnode *passed_tn);
960 
961 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
962 		     int n_bytes, int write_trhrough);
963 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size);
964 void yaffs_skip_rest_of_block(struct yaffs_dev *dev);
965 
966 int yaffs_count_free_chunks(struct yaffs_dev *dev);
967 
968 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
969 				       struct yaffs_file_var *file_struct,
970 				       u32 chunk_id);
971 
972 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
973 			 unsigned pos);
974 
975 int yaffs_is_non_empty_dir(struct yaffs_obj *obj);
976 
977 int yaffs_format_dev(struct yaffs_dev *dev);
978 
979 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
980 				int *chunk_out, u32 *offset_out);
981 /*
982  * Marshalling functions to get loff_t file sizes into aand out of
983  * object headers.
984  */
985 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize);
986 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh);
987 loff_t yaffs_max_file_size(struct yaffs_dev *dev);
988 
989 
990 #endif
991