/**
* @file
*
* @brief RTEMS File Systems Group Management
*
* @ingroup rtems_rfs
*
* RTEMS File Systems Group Management.
*
* These functions manage the groups used in the file system.
*/
/*
* COPYRIGHT (c) 2010 Chris Johns <chrisj@rtems.org>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if !defined (_RTEMS_RFS_GROUP_H_)
#define _RTEMS_RFS_GROUP_H_
/**
* @ingroup rtems_rfs
*
* RTEMS File System Group Management
*/
/**@{*/
#include <rtems/rfs/rtems-rfs-trace.h>
#include <rtems/rfs/rtems-rfs-bitmaps.h>
#include <rtems/rfs/rtems-rfs-buffer.h>
/**
* Block allocations for a group on disk.
*/
#define RTEMS_RFS_GROUP_BLOCK_BITMAP_BLOCK (0)
#define RTEMS_RFS_GROUP_INODE_BITMAP_BLOCK (1)
#define RTEMS_RFS_GROUP_INODE_BLOCK (2)
/**
* @brief Creates bit allocator for blocks in the group simpler.
*
* A group is a selection of blocks on the disk. Typically the number of blocks
* in a group is determined by the number of bits a block holds. This makes the
* bit allocator for blocks in the group simpler plus is allows a simple way to
* localise access to files and directories.
*/
typedef struct _rtems_rfs_group
{
/**
* Base block number.
*/
rtems_rfs_buffer_block base;
/**
* The number of blocks in the group. Groups may be different sizes.
*/
size_t size;
/**
* The block bitmap control.
*/
rtems_rfs_bitmap_control block_bitmap;
/**
* The handle to the block bitmap buffer.
*/
rtems_rfs_buffer_handle block_bitmap_buffer;
/**
* The inode bitmap control.
*/
rtems_rfs_bitmap_control inode_bitmap;
/**
* The handle to the inode bitmap buffer.
*/
rtems_rfs_buffer_handle inode_bitmap_buffer;
} rtems_rfs_group;
/**
* Return the disk's block for a block in a group.
*/
#define rtems_rfs_group_block(_g, _b) (((_g)->base) + (_b))
/**
* Return the file system inode for a inode in a group.
*/
#define rtems_rfs_group_inode(_f, _g, _i) \
(((_f)->group_inodes * (_g)) + (_i) + RTEMS_RFS_ROOT_INO)
/**
* @brief Open a group.
*
* Allocate all the resources including the bitmaps.
*
* @param fs The file system.
* @param base The base block number.
* @param size The number of blocks in the group.
* @param group Reference to the group to open.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_open (rtems_rfs_file_system* fs,
rtems_rfs_buffer_block base,
size_t size,
size_t inodes,
rtems_rfs_group* group);
/**
* @brief Close a group.
*
* Release all resources the group holds.
*
* @param fs The file system.
* @param group The group to close.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_close (rtems_rfs_file_system* fs,
rtems_rfs_group* group);
/**
* @brief Allocate an inode or block.
*
* The groups are searched to find the next
* available inode or block.
*
* @param fs The file system data.
* @param goal The goal to seed the bitmap search.
* @param inode If true allocate an inode else allocate a block.
* @param result The allocated bit in the bitmap.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_bitmap_alloc (rtems_rfs_file_system* fs,
rtems_rfs_bitmap_bit goal,
bool inode,
rtems_rfs_bitmap_bit* result);
/**
* @brief Free the group allocated bit.
*
* @param fs The file system data.
* @param inode If true the number to free is an inode else it is a block.
* @param block The inode or block number to free.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_bitmap_free (rtems_rfs_file_system* fs,
bool inode,
rtems_rfs_bitmap_bit no);
/**
* @brief Test the group allocated bit.
*
* @param fs The file system data.
* @param inode If true the number to free is an inode else it is a block.
* @param block The inode or block number to free.
* @param state Return the state of the bit.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_bitmap_test (rtems_rfs_file_system* fs,
bool inode,
rtems_rfs_bitmap_bit no,
bool* state);
/**
* @brief Determine the number of blocks and inodes used.
*
* @param fs The file system data.
* @param blocks The number of blocks used.
* @param inodes The number of inodes used.
* @retval int The error number (errno). No error if 0.
*/
int rtems_rfs_group_usage (rtems_rfs_file_system* fs,
size_t* blocks,
size_t* inodes);
/** @} */
#endif
