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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 (at) 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