hfs.h

嵌入式系统设计与实验教材二源码linux内核移植与编译

	int			bitmap_lock;
        struct list_head        entry_dirty;
};

/*
 * struct hfs_extent
 *
 * The offset to allocation block mapping for a given file is
 * contained in a series of these structures.  Each (struct
 * hfs_extent) records up to three runs of contiguous allocation
 * blocks.  An allocation block is a contiguous group of physical
 * blocks.
 */
struct hfs_extent {
	int		   magic;     /* A magic number */
	unsigned short	   start;     /* Where in the file this record
					 begins (in allocation blocks) */
	unsigned short	   end;	      /* Where in the file this record
					 ends (in allocation blocks) */
	unsigned short	   block[3];  /* The allocation block on disk which
					 begins this extent */
	unsigned short	   length[3]; /* The number of allocation blocks
					 in this extent */
	struct hfs_extent  *next;     /* Next extent record for this file */
	struct hfs_extent  *prev;     /* Previous extent record for this file */
	int		   count;     /* Number of times it is used */
};

/*
 * struct hfs_dir 
 *
 * This structure holds information specific
 * to a directory in an HFS filesystem.
 */
struct hfs_dir {		
	int		magic;		/* A magic number */
	hfs_u16		flags;
	hfs_u16		dirs;		/* Number of directories in this one */
	hfs_u16		files;		/* Number of files in this directory */
	int		readers;
	hfs_wait_queue	read_wait;
	int		writers;
	hfs_wait_queue	write_wait;
};

/*
 * struct hfs_fork
 *
 * This structure holds the information
 * specific to a single fork of a file.
 */
struct hfs_fork {
	struct hfs_cat_entry	*entry;    /* The file this fork is part of */
	struct hfs_extent	first;     /* The first extent record for
						 this fork */
	struct hfs_extent	*cache;    /* The most-recently accessed
						 extent record for this fork */
	hfs_u32			lsize;     /* The logical size in bytes */
	hfs_u32			psize;     /* The phys size (512-byte blocks) */
        hfs_u8			fork;      /* Which fork is this? */
};

/*
 * struct hfs_file 
 *
 * This structure holds information specific
 * to a file in an HFS filesystem.
 */
struct hfs_file {
	int		   magic;
	struct hfs_fork    data_fork;
	struct hfs_fork    rsrc_fork;
	hfs_u16		   clumpablks;
	hfs_u8		   flags;
};

/*
 * struct hfs_file 
 *
 * This structure holds information about a
 * file or directory in an HFS filesystem.
 *
 * 'wait' must remain 1st and 'hash' 2nd since we do some pointer arithmetic.
 */
struct hfs_cat_entry {
	hfs_wait_queue		wait;
        struct list_head        hash;
        struct list_head        list;
	struct hfs_mdb		*mdb;
	hfs_sysentry		sys_entry;
	struct hfs_cat_key	key;
	union hfs_finder_info	info;
	hfs_u32			cnid;		/* In network byte-order */
	hfs_u32			create_date;	/* In network byte-order */
	hfs_u32			modify_date;	/* In network byte-order */
	hfs_u32			backup_date;	/* In network byte-order */
	unsigned short		count;
        unsigned long           state;
	hfs_u8			type;
	union {
		struct hfs_dir	dir;
		struct hfs_file file;
	} u;
};

/* hfs entry state bits */
#define HFS_DIRTY        1
#define HFS_KEYDIRTY     2
#define HFS_LOCK         4
#define HFS_DELETED      8

/* 
 * struct hfs_bnode_ref
 *
 * A pointer to a (struct hfs_bnode) and the type of lock held on it.
 */
struct hfs_bnode_ref {
        struct hfs_bnode *bn;
        int lock_type;
};

/*
 * struct hfs_belem
 *
 * An element of the path from the root of a B-tree to a leaf.
 * Includes the reference to a (struct hfs_bnode), the index of
 * the appropriate record in that node, and some flags.
 */
struct hfs_belem {
	struct hfs_bnode_ref	bnr;
	int			record;
	int			flags;
};

/*
 * struct hfs_brec
 *
 * The structure returned by hfs_bfind() to describe the requested record.
 */
struct hfs_brec {
	int			keep_flags;
	struct hfs_btree	*tree;
	struct hfs_belem	*top;
	struct hfs_belem	*bottom;
	struct hfs_belem	elem[9];
	struct hfs_bkey		*key;
	void			*data;	/* The actual data */
};

/*================ Function prototypes ================*/

/* bdelete.c */
extern int hfs_bdelete(struct hfs_btree *, const struct hfs_bkey *);

/* bfind.c */
extern void hfs_brec_relse(struct hfs_brec *, struct hfs_belem *);
extern int hfs_bsucc(struct hfs_brec *, int);
extern int hfs_bfind(struct hfs_brec *, struct hfs_btree *,
		     const struct hfs_bkey *, int);
 
/* binsert.c */
extern int hfs_binsert(struct hfs_btree *, const struct hfs_bkey *,
		       const void *, hfs_u16);

/* bitmap.c */
extern hfs_u16 hfs_vbm_count_free(const struct hfs_mdb *, hfs_u16);
extern hfs_u16 hfs_vbm_search_free(const struct hfs_mdb *, hfs_u16 *);
extern int hfs_set_vbm_bits(struct hfs_mdb *, hfs_u16, hfs_u16);
extern int hfs_clear_vbm_bits(struct hfs_mdb *, hfs_u16, hfs_u16);

/* bitops.c */
extern hfs_u32 hfs_find_zero_bit(const hfs_u32 *, hfs_u32, hfs_u32);
extern hfs_u32 hfs_count_zero_bits(const hfs_u32 *, hfs_u32, hfs_u32);

/* btree.c */
extern struct hfs_btree *hfs_btree_init(struct hfs_mdb *, ino_t,
				        hfs_byte_t *, hfs_u32, hfs_u32);
extern void hfs_btree_free(struct hfs_btree *);
extern void hfs_btree_commit(struct hfs_btree *, hfs_byte_t *, hfs_lword_t);

/* catalog.c */
extern void hfs_cat_init(void);
extern void hfs_cat_put(struct hfs_cat_entry *);
extern void hfs_cat_mark_dirty(struct hfs_cat_entry *);
extern struct hfs_cat_entry *hfs_cat_get(struct hfs_mdb *,
					 const struct hfs_cat_key *);

extern void hfs_cat_invalidate(struct hfs_mdb *);
extern void hfs_cat_commit(struct hfs_mdb *);
extern void hfs_cat_free(void);

extern int hfs_cat_compare(const struct hfs_cat_key *,
			   const struct hfs_cat_key *);
extern void hfs_cat_build_key(hfs_u32, const struct hfs_name *,
			      struct hfs_cat_key *);
extern struct hfs_cat_entry *hfs_cat_parent(struct hfs_cat_entry *);

extern int hfs_cat_open(struct hfs_cat_entry *, struct hfs_brec *);
extern int hfs_cat_next(struct hfs_cat_entry *, struct hfs_brec *,
			hfs_u16, hfs_u32 *, hfs_u8 *);
extern void hfs_cat_close(struct hfs_cat_entry *, struct hfs_brec *);

extern int hfs_cat_create(struct hfs_cat_entry *, struct hfs_cat_key *,
			  hfs_u8, hfs_u32, hfs_u32, struct hfs_cat_entry **);
extern int hfs_cat_mkdir(struct hfs_cat_entry *, struct hfs_cat_key *,
			 struct hfs_cat_entry **);
extern int hfs_cat_delete(struct hfs_cat_entry *, struct hfs_cat_entry *, int);
extern int hfs_cat_move(struct hfs_cat_entry *, struct hfs_cat_entry *,
			struct hfs_cat_entry *, struct hfs_cat_key *,
			struct hfs_cat_entry **);

/* extent.c */
extern int hfs_ext_compare(const struct hfs_ext_key *,
			   const struct hfs_ext_key *);
extern void hfs_extent_in(struct hfs_fork *, const hfs_byte_t *);
extern void hfs_extent_out(const struct hfs_fork *, hfs_byte_t *);
extern int hfs_extent_map(struct hfs_fork *, int, int);
extern void hfs_extent_adj(struct hfs_fork *);
extern void hfs_extent_free(struct hfs_fork *);

/* file.c */
extern int hfs_get_block(struct inode *, long, struct buffer_head *, int);

/* mdb.c */
extern struct hfs_mdb *hfs_mdb_get(hfs_sysmdb, int, hfs_s32);
extern void hfs_mdb_commit(struct hfs_mdb *, int);
extern void hfs_mdb_put(struct hfs_mdb *, int);

/* part_tbl.c */
extern int hfs_part_find(hfs_sysmdb, int, int, hfs_s32 *, hfs_s32 *);

/* string.c */
extern unsigned int hfs_strhash(const unsigned char *, unsigned int);
extern int hfs_strcmp(const unsigned char *, unsigned int, 
		      const unsigned char *, unsigned int);
extern int hfs_streq(const unsigned char *, unsigned int, 
		     const unsigned char *, unsigned int);
extern void hfs_tolower(unsigned char *, int);

static __inline__ struct dentry 
*hfs_lookup_dentry(struct dentry *base, const char *name, const int len)
{
  struct qstr this;

  this.name = name;
  this.len = len;
  this.hash = hfs_strhash(name, len);

  return d_lookup(base, &this);
}

/* drop a dentry for one of the special directories.
 * it's in the form of base/name/dentry. */
static __inline__ void hfs_drop_special(struct dentry *base,
					const struct hfs_name *name,
					struct dentry *dentry)
{
  struct dentry *dparent, *de;
  
  dparent = hfs_lookup_dentry(base, name->Name, name->Len);
  if (dparent) {
	  de = hfs_lookup_dentry(dparent, dentry->d_name.name, 
				 dentry->d_name.len);
	  if (de) {
		  if (!de->d_inode)
			  d_drop(de);
		  dput(de);
	  }
	  dput(dparent);
  }
}

extern struct dentry_operations hfs_dentry_operations;
#endif