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/**
* @file
*
* @brief RTEMS File System Data
*
* @ingroup rtems_rfs
*
* RTEMS File System Data
*
* This file defines the file system data.
*/
/*
* 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_FILE_SYSTEM_H_)
#define _RTEMS_RFS_FILE_SYSTEM_H_
#include <rtems/rfs/rtems-rfs-group.h>
/**
* Superblock offsets and values.
*/
#define RTEMS_RFS_SB_OFFSET_MAGIC (0)
#define RTEMS_RFS_SB_MAGIC (0x28092001)
#define RTEMS_RFS_SB_OFFSET_VERSION (RTEMS_RFS_SB_OFFSET_MAGIC + 4)
#define RTEMS_RFS_SB_OFFSET_BLOCK_SIZE (RTEMS_RFS_SB_OFFSET_VERSION + 4)
#define RTEMS_RFS_SB_OFFSET_BLOCKS (RTEMS_RFS_SB_OFFSET_BLOCK_SIZE + 4)
#define RTEMS_RFS_SB_OFFSET_BAD_BLOCKS (RTEMS_RFS_SB_OFFSET_BLOCKS + 4)
#define RTEMS_RFS_SB_OFFSET_MAX_NAME_LENGTH (RTEMS_RFS_SB_OFFSET_BAD_BLOCKS + 4)
#define RTEMS_RFS_SB_OFFSET_GROUPS (RTEMS_RFS_SB_OFFSET_MAX_NAME_LENGTH + 4)
#define RTEMS_RFS_SB_OFFSET_GROUP_BLOCKS (RTEMS_RFS_SB_OFFSET_GROUPS + 4)
#define RTEMS_RFS_SB_OFFSET_GROUP_INODES (RTEMS_RFS_SB_OFFSET_GROUP_BLOCKS + 4)
#define RTEMS_RFS_SB_OFFSET_INODE_SIZE (RTEMS_RFS_SB_OFFSET_GROUP_INODES + 4)
/**
* RFS Version Number.
*/
#define RTEMS_RFS_VERSION (0x00000000)
/**
* RFS Version Number Mask. The mask determines which bits of the version
* number indicate compatility issues.
*/
#define RTEMS_RFS_VERSION_MASK INT32_C(0x00000000)
/**
* The root inode number. Do not use 0 as this has special meaning in some
* Unix operating systems.
*/
#define RTEMS_RFS_ROOT_INO (1)
/**
* Empty inode number.
*/
#define RTEMS_RFS_EMPTY_INO (0)
/**
* The number of blocks in the inode. This number effects the size of the
* inode and that effects the overhead of the inode tables in a group.
*/
#define RTEMS_RFS_INODE_BLOCKS (5)
/**
* The inode overhead is the percentage of space reserved for inodes. It is
* calculated as the percentage number of blocks in a group. The number of
* blocks in a group is the number of bits a block can hold.
*/
#define RTEMS_RFS_INODE_OVERHEAD_PERCENTAGE (1)
/**
* Number of blocks in the superblock. Yes I know it is a superblock and not
* superblocks but if for any reason this needs to change it is handled.
*/
#define RTEMS_RFS_SUPERBLOCK_SIZE (1)
/**
* The maximum number of buffers held by the file system at any one time.
*/
#define RTEMS_RFS_FS_MAX_HELD_BUFFERS (5)
/**
* Absolute position. Make a 64bit value.
*/
typedef uint64_t rtems_rfs_pos;
/**
* Relative position. Make a 64bit value.
*/
typedef int64_t rtems_rfs_pos_rel;
/**
* Flags to control the file system.
*/
#define RTEMS_RFS_FS_BITMAPS_HOLD (1 << 0) /**< Do not release bitmaps
* when finished. Default is
* off so they are released. */
#define RTEMS_RFS_FS_NO_LOCAL_CACHE (1 << 1) /**< Do not cache the buffers
* and release directly to the
* buffer support layer. The
* default is to hold buffers. */
#define RTEMS_RFS_FS_FORCE_OPEN (1 << 2) /**< Force open and ignore any
* errors. */
#define RTEMS_RFS_FS_READ_ONLY (1 << 3) /**< Make the mount
* read-only. Currently not
* supported. */
/**
* RFS File System data.
*/
struct _rtems_rfs_file_system
{
/**
* Flags to control the file system. Some can be controlled via the ioctl.
*/
uint32_t flags;
/**
* The number of blocks in the disk. The size of the disk is the number of
* blocks by the block size. This should be within a block size of the size
* returned by the media driver.
*/
size_t blocks;
/**
* The size of a block. This must be a multiple of the disk's media block
* size.
*/
size_t block_size;
/**
* The file descriptor for device I/O.
*/
int device;
#if RTEMS_RFS_USE_LIBBLOCK
/**
* The disk device. This is the data about the block device this file system
* is mounted on. We access the data held in this structure rather than
* making an extra copy in this structure.
*/
rtems_disk_device* disk;
#else
/**
* The number of blocks in the file system.
*/
size_t size;
#endif
/**
* Inode count.
*/
uint32_t inodes;
/**
* Bad block blocks. This is a table of blocks that have been found to be
* bad.
*/
uint32_t bad_blocks;
/**
* Maximum length of names supported by this file system.
*/
uint32_t max_name_length;
/**
* A disk is broken down into a series of groups.
*/
rtems_rfs_group* groups;
/**
* Number of groups.
*/
int group_count;
/**
* Number of blocks in a group.
*/
size_t group_blocks;
/**
* Number of inodes in a group.
*/
size_t group_inodes;
/**
* Number of inodes in each block.
*/
size_t inodes_per_block;
/**
* Number of block numbers in a block.
*/
size_t blocks_per_block;
/**
* Block map single indirect count. This is the block number per block
* multiplied but the slots in the inode.
*/
size_t block_map_singly_blocks;
/**
* Block map double indirect count. This is the block number per block
* squared and multiplied by the slots in the inode. It is the maximum
* number of blocks a map (file/directory) can have.
*/
size_t block_map_doubly_blocks;
/**
* Number of buffers held before releasing back to the cache.
*/
uint32_t max_held_buffers;
/**
* List of buffers attached to buffer handles. Allows sharing.
*/
rtems_chain_control buffers;
/**
* Number of buffers held on the buffers list.
*/
uint32_t buffers_count;
/**
* List of buffers that need to be released when the processing of a file
* system request has completed.
*/
rtems_chain_control release;
/**
* Number of buffers held on the release list.
*/
uint32_t release_count;
/**
* List of buffers that need to be released modified when the processing of a
* file system request has completed.
*/
rtems_chain_control release_modified;
/**
* Number of buffers held on the release modified list.
*/
uint32_t release_modified_count;
/**
* List of open shared file node data. The shared node data such as the inode
* and block map allows a single file to be open more than once.
*/
rtems_chain_control file_shares;
/**
* Pointer to user data supplied when opening.
*/
void* user;
};
/**
* Return the flags.
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_flags(_f) ((_f)->flags)
/**
* Should bitmap buffers be released when finished ?
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_release_bitmaps(_f) (!((_f)->flags & RTEMS_RFS_FS_BITMAPS_HOLD))
/**
* Are the buffers locally cache or released back to the buffering layer ?
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_no_local_cache(_f) ((_f)->flags & RTEMS_RFS_FS_NO_LOCAL_CACHE)
/**
* The disk device number.
*
* @param[in] _fs is a pointer to the file system.
*/
#if RTEMS_RFS_USE_LIBBLOCK
#define rtems_rfs_fs_device(_fs) ((_fs)->disk)
#else
#define rtems_rfs_fs_device(_fs) ((_fs)->device)
#endif
/**
* The size of the disk in blocks.
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_blocks(_fs) ((_fs)->blocks)
/**
* The block size.
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_block_size(_fs) ((_fs)->block_size)
/**
* The number of inodes.
*
* @param[in] _fs is a pointer to the file system.
*/
#define rtems_rfs_fs_inodes(_fs) ((_fs)->inodes)
/**
* Calculate a block in the file system given the group and the block within
* the group.
*
* @param[in] _fs is a pointer to the file system.
* @param[in] _grp is the group.
* @param[in] _blk is the block within the group.
* @return The absolute block number.
*/
#define rtems_rfs_fs_block(_fs, _grp, _blk) \
((((_fs)->group_blocks) * (_grp)) + (_blk) + 1)
/**
* The media size of the disk in media size blocks.
*
* @param[in] _fs is a pointer to the file system.
*/
#if RTEMS_RFS_USE_LIBBLOCK
#define rtems_rfs_fs_media_blocks(_fs) ((_fs)->disk->size)
#else
#define rtems_rfs_fs_media_blocks(_fs) ((_fs)->media_size)
#endif
/**
* The media block size. This is the size of a block on disk. For a device I/O
* this value is 1.
*
* @param[in] _fs is a pointer to the file system.
*/
#if RTEMS_RFS_USE_LIBBLOCK
#define rtems_rfs_fs_media_block_size(_fs) ((_fs)->disk->media_block_size)
#else
#define rtems_rfs_fs_media_block_size(_fs) (1)
#endif
/**
* The maximum length of a name supported by the file system.
*/
#define rtems_rfs_fs_max_name(_fs) ((_fs)->max_name_length)
/**
* Return the maximum number of blocks in a block map.
*
* @return uint32_t The maximum number of blocks possible.
*/
#define rtems_rfs_fs_max_block_map_blocks(_fs) ((_fs)->block_map_doubly_blocks)
/**
* Return the user pointer.
*/
#define rtems_rfs_fs_user(_fs) ((_fs)->user)
/**
* Return the size of the disk in bytes.
*
* @param[in] fs is a pointer to the file system.
* @return uint64_t The size of the disk in bytes.
*/
uint64_t rtems_rfs_fs_size(rtems_rfs_file_system* fs);
/**
* The size of the disk in bytes calculated from the media parameters..
*
* @param[in] fs is a pointer to the file system.
* @return uint64_t The size of the disk in bytes.
*/
uint64_t rtems_rfs_fs_media_size (rtems_rfs_file_system* fs);
/**
* Open the file system given a file path.
*
* @param[in] name is a pointer to the device to open.
* @param[in] fs is the file system data filled in by this call.
* @param[in] user is a pointer to the user data.
* @param[in] flags is a initial set of user flags for the file system.
* @param[in] max_held_buffers is the maximum number of buffers the RFS holds.
*
* @retval 0 Successful operation.
* @retval -1 Error. See errno
*/
int rtems_rfs_fs_open (const char* name,
void* user,
uint32_t flags,
uint32_t max_held_buffers,
rtems_rfs_file_system** fs);
/**
* Close the file system.
*
* @param[in] fs is the file system data.
*
* @retval 0 Successful operation.
* @retval -1 Error. See errno
*/
int rtems_rfs_fs_close (rtems_rfs_file_system* fs);
#endif
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