reiserfs_fs.h

linux得一些常用命令,以及linux环境下的c编程

   to it as that parameter. */
#define REISERFS_FULL_KEY_LEN     4
#define REISERFS_SHORT_KEY_LEN    2

/* The result of the key compare */
#define FIRST_GREATER 1
#define SECOND_GREATER -1
#define KEYS_IDENTICAL 0
#define KEY_FOUND 1
#define KEY_NOT_FOUND 0

#define KEY_SIZE (sizeof(struct key))
#define SHORT_KEY_SIZE (sizeof (__u32) + sizeof (__u32))

/* return values for search_by_key and clones */
#define ITEM_FOUND 1
#define ITEM_NOT_FOUND 0
#define ENTRY_FOUND 1
#define ENTRY_NOT_FOUND 0
#define DIRECTORY_NOT_FOUND -1
#define REGULAR_FILE_FOUND -2
#define DIRECTORY_FOUND -3
#define BYTE_FOUND 1
#define BYTE_NOT_FOUND 0
#define FILE_NOT_FOUND -1

#define POSITION_FOUND 1
#define POSITION_NOT_FOUND 0

// return values for reiserfs_find_entry and search_by_entry_key
#define NAME_FOUND 1
#define NAME_NOT_FOUND 0
#define GOTO_PREVIOUS_ITEM 2
#define NAME_FOUND_INVISIBLE 3

/*  Everything in the filesystem is stored as a set of items.  The
    item head contains the key of the item, its free space (for
    indirect items) and specifies the location of the item itself
    within the block.  */

struct item_head
{
	/* Everything in the tree is found by searching for it based on
	 * its key.*/
	struct key ih_key; 	
	union {
		/* The free space in the last unformatted node of an
		   indirect item if this is an indirect item.  This
		   equals 0xFFFF iff this is a direct item or stat data
		   item. Note that the key, not this field, is used to
		   determine the item type, and thus which field this
		   union contains. */
		__u16 ih_free_space_reserved; 
		/* Iff this is a directory item, this field equals the
		   number of directory entries in the directory item. */
		__u16 ih_entry_count; 
	} __attribute__ ((__packed__)) u;
	__u16 ih_item_len;           /* total size of the item body */
	__u16 ih_item_location;      /* an offset to the item body
				      * within the block */
	__u16 ih_version;	     /* 0 for all old items, 2 for new
					ones. Highest bit is set by fsck
					temporary, cleaned after all
					done */
} __attribute__ ((__packed__));
/* size of item header     */
#define IH_SIZE (sizeof(struct item_head))

#define ih_free_space(ih)            le16_to_cpu((ih)->u.ih_free_space_reserved)
#define ih_version(ih)               le16_to_cpu((ih)->ih_version)
#define ih_entry_count(ih)           le16_to_cpu((ih)->u.ih_entry_count)
#define ih_location(ih)              le16_to_cpu((ih)->ih_item_location)
#define ih_item_len(ih)              le16_to_cpu((ih)->ih_item_len)

#define put_ih_free_space(ih, val)   do { (ih)->u.ih_free_space_reserved = cpu_to_le16(val); } while(0)
#define put_ih_version(ih, val)      do { (ih)->ih_version = cpu_to_le16(val); } while (0)
#define put_ih_entry_count(ih, val)  do { (ih)->u.ih_entry_count = cpu_to_le16(val); } while (0)
#define put_ih_location(ih, val)     do { (ih)->ih_item_location = cpu_to_le16(val); } while (0)
#define put_ih_item_len(ih, val)     do { (ih)->ih_item_len = cpu_to_le16(val); } while (0)


#define unreachable_item(ih) (ih_version(ih) & (1 << 15))

#define get_ih_free_space(ih) (ih_version (ih) == KEY_FORMAT_3_6 ? 0 : ih_free_space (ih))
#define set_ih_free_space(ih,val) put_ih_free_space((ih), ((ih_version(ih) == KEY_FORMAT_3_6) ? 0 : (val)))

/* these operate on indirect items, where you've got an array of ints
** at a possibly unaligned location.  These are a noop on ia32
** 
** p is the array of __u32, i is the index into the array, v is the value
** to store there.
*/
#define get_block_num(p, i) le32_to_cpu(get_unaligned((p) + (i)))
#define put_block_num(p, i, v) put_unaligned(cpu_to_le32(v), (p) + (i))

//
// in old version uniqueness field shows key type
//
#define V1_SD_UNIQUENESS 0
#define V1_INDIRECT_UNIQUENESS 0xfffffffe
#define V1_DIRECT_UNIQUENESS 0xffffffff
#define V1_DIRENTRY_UNIQUENESS 500
#define V1_ANY_UNIQUENESS 555 // FIXME: comment is required

extern void reiserfs_warning (const char * fmt, ...);
/* __attribute__( ( format ( printf, 1, 2 ) ) ); */

//
// here are conversion routines
//
static inline int uniqueness2type (__u32 uniqueness) CONSTF;
static inline int uniqueness2type (__u32 uniqueness)
{
    switch (uniqueness) {
    case V1_SD_UNIQUENESS: return TYPE_STAT_DATA;
    case V1_INDIRECT_UNIQUENESS: return TYPE_INDIRECT;
    case V1_DIRECT_UNIQUENESS: return TYPE_DIRECT;
    case V1_DIRENTRY_UNIQUENESS: return TYPE_DIRENTRY;
    default:
	    reiserfs_warning( "vs-500: unknown uniqueness %d\n", uniqueness);
	case V1_ANY_UNIQUENESS:
	    return TYPE_ANY;
    }
}

static inline __u32 type2uniqueness (int type) CONSTF;
static inline __u32 type2uniqueness (int type)
{
    switch (type) {
    case TYPE_STAT_DATA: return V1_SD_UNIQUENESS;
    case TYPE_INDIRECT: return V1_INDIRECT_UNIQUENESS;
    case TYPE_DIRECT: return V1_DIRECT_UNIQUENESS;
    case TYPE_DIRENTRY: return V1_DIRENTRY_UNIQUENESS;
    default:
	    reiserfs_warning( "vs-501: unknown type %d\n", type);
	case TYPE_ANY:
	    return V1_ANY_UNIQUENESS;
    }
}

//
// key is pointer to on disk key which is stored in le, result is cpu,
// there is no way to get version of object from key, so, provide
// version to these defines
//
static inline loff_t le_key_k_offset (int version, const struct key * key)
{
    return (version == KEY_FORMAT_3_5) ?
        le32_to_cpu( key->u.k_offset_v1.k_offset ) :
	offset_v2_k_offset( &(key->u.k_offset_v2) );
}

static inline loff_t le_ih_k_offset (const struct item_head * ih)
{
    return le_key_k_offset (ih_version (ih), &(ih->ih_key));
}

static inline loff_t le_key_k_type (int version, const struct key * key)
{
    return (version == KEY_FORMAT_3_5) ?
        uniqueness2type( le32_to_cpu( key->u.k_offset_v1.k_uniqueness)) :
	offset_v2_k_type( &(key->u.k_offset_v2) );
}

static inline loff_t le_ih_k_type (const struct item_head * ih)
{
    return le_key_k_type (ih_version (ih), &(ih->ih_key));
}


static inline void set_le_key_k_offset (int version, struct key * key, loff_t offset)
{
    (version == KEY_FORMAT_3_5) ?
        (key->u.k_offset_v1.k_offset = cpu_to_le32 (offset)) : /* jdm check */
	(set_offset_v2_k_offset( &(key->u.k_offset_v2), offset ));
}


static inline void set_le_ih_k_offset (struct item_head * ih, loff_t offset)
{
    set_le_key_k_offset (ih_version (ih), &(ih->ih_key), offset);
}


static inline void set_le_key_k_type (int version, struct key * key, int type)
{
    (version == KEY_FORMAT_3_5) ?
        (key->u.k_offset_v1.k_uniqueness = cpu_to_le32(type2uniqueness(type))):
	(set_offset_v2_k_type( &(key->u.k_offset_v2), type ));
}
static inline void set_le_ih_k_type (struct item_head * ih, int type)
{
    set_le_key_k_type (ih_version (ih), &(ih->ih_key), type);
}


#define is_direntry_le_key(version,key) (le_key_k_type (version, key) == TYPE_DIRENTRY)
#define is_direct_le_key(version,key) (le_key_k_type (version, key) == TYPE_DIRECT)
#define is_indirect_le_key(version,key) (le_key_k_type (version, key) == TYPE_INDIRECT)
#define is_statdata_le_key(version,key) (le_key_k_type (version, key) == TYPE_STAT_DATA)

//
// item header has version.
//
#define is_direntry_le_ih(ih) is_direntry_le_key (ih_version (ih), &((ih)->ih_key))
#define is_direct_le_ih(ih) is_direct_le_key (ih_version (ih), &((ih)->ih_key))
#define is_indirect_le_ih(ih) is_indirect_le_key (ih_version(ih), &((ih)->ih_key))
#define is_statdata_le_ih(ih) is_statdata_le_key (ih_version (ih), &((ih)->ih_key))



//
// key is pointer to cpu key, result is cpu
//
static inline loff_t cpu_key_k_offset (const struct cpu_key * key)
{
    return (key->version == KEY_FORMAT_3_5) ?
        key->on_disk_key.u.k_offset_v1.k_offset :
	key->on_disk_key.u.k_offset_v2.k_offset;
}

static inline loff_t cpu_key_k_type (const struct cpu_key * key)
{
    return (key->version == KEY_FORMAT_3_5) ?
        uniqueness2type (key->on_disk_key.u.k_offset_v1.k_uniqueness) :
	key->on_disk_key.u.k_offset_v2.k_type;
}

static inline void set_cpu_key_k_offset (struct cpu_key * key, loff_t offset)
{
    (key->version == KEY_FORMAT_3_5) ?
        (key->on_disk_key.u.k_offset_v1.k_offset = offset) :
	(key->on_disk_key.u.k_offset_v2.k_offset = offset);
}


static inline void set_cpu_key_k_type (struct cpu_key * key, int type)
{
    (key->version == KEY_FORMAT_3_5) ?
        (key->on_disk_key.u.k_offset_v1.k_uniqueness = type2uniqueness (type)):
	(key->on_disk_key.u.k_offset_v2.k_type = type);
}


static inline void cpu_key_k_offset_dec (struct cpu_key * key)
{
    if (key->version == KEY_FORMAT_3_5)
	key->on_disk_key.u.k_offset_v1.k_offset --;
    else
	key->on_disk_key.u.k_offset_v2.k_offset --;
}


#define is_direntry_cpu_key(key) (cpu_key_k_type (key) == TYPE_DIRENTRY)
#define is_direct_cpu_key(key) (cpu_key_k_type (key) == TYPE_DIRECT)
#define is_indirect_cpu_key(key) (cpu_key_k_type (key) == TYPE_INDIRECT)
#define is_statdata_cpu_key(key) (cpu_key_k_type (key) == TYPE_STAT_DATA)


/* are these used ? */
#define is_direntry_cpu_ih(ih) (is_direntry_cpu_key (&((ih)->ih_key)))
#define is_direct_cpu_ih(ih) (is_direct_cpu_key (&((ih)->ih_key)))
#define is_indirect_cpu_ih(ih) (is_indirect_cpu_key (&((ih)->ih_key)))
#define is_statdata_cpu_ih(ih) (is_statdata_cpu_key (&((ih)->ih_key)))





#define I_K_KEY_IN_ITEM(p_s_ih, p_s_key, n_blocksize) \
    ( ! COMP_SHORT_KEYS(p_s_ih, p_s_key) && \
          I_OFF_BYTE_IN_ITEM(p_s_ih, k_offset (p_s_key), n_blocksize) )

/* maximal length of item */ 
#define MAX_ITEM_LEN(block_size) (block_size - BLKH_SIZE - IH_SIZE)
#define MIN_ITEM_LEN 1


/* object identifier for root dir */
#define REISERFS_ROOT_OBJECTID 2
#define REISERFS_ROOT_PARENT_OBJECTID 1
extern struct key root_key;




/* 
 * Picture represents a leaf of the S+tree
 *  ______________________________________________________
 * |      |  Array of     |                   |           |
 * |Block |  Object-Item  |      F r e e      |  Objects- |
 * | head |  Headers      |     S p a c e     |   Items   |
 * |______|_______________|___________________|___________|
 */

/* Header of a disk block.  More precisely, header of a formatted leaf
   or internal node, and not the header of an unformatted node. */
struct block_head {       
  __u16 blk_level;        /* Level of a block in the tree. */
  __u16 blk_nr_item;      /* Number of keys/items in a block. */
  __u16 blk_free_space;   /* Block free space in bytes. */
  __u16 blk_reserved;
				/* dump this in v4/planA */
  struct key  blk_right_delim_key; /* kept only for compatibility */
};

#define BLKH_SIZE                     (sizeof(struct block_head))
#define blkh_level(p_blkh)            (le16_to_cpu((p_blkh)->blk_level))
#define blkh_nr_item(p_blkh)          (le16_to_cpu((p_blkh)->blk_nr_item))
#define blkh_free_space(p_blkh)       (le16_to_cpu((p_blkh)->blk_free_space))
#define blkh_reserved(p_blkh)         (le16_to_cpu((p_blkh)->blk_reserved))
#define set_blkh_level(p_blkh,val)    ((p_blkh)->blk_level = cpu_to_le16(val))
#define set_blkh_nr_item(p_blkh,val)  ((p_blkh)->blk_nr_item = cpu_to_le16(val))
#define set_blkh_free_space(p_blkh,val) ((p_blkh)->blk_free_space = cpu_to_le16(val))
#define set_blkh_reserved(p_blkh,val) ((p_blkh)->blk_reserved = cpu_to_le16(val))
#define blkh_right_delim_key(p_blkh)  ((p_blkh)->blk_right_delim_key)
#define set_blkh_right_delim_key(p_blkh,val)  ((p_blkh)->blk_right_delim_key = val)