rtems/rfs/rtems-rfs-group.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @brief RTEMS File Systems Group Management
0007  *
0008  * @ingroup rtems_rfs
0009  *
0010  * RTEMS File Systems Group Management.
0011  *
0012  * These functions manage the groups used in the file system.
0013  */
0014
0015 /*
0016  *  COPYRIGHT (c) 2010 Chris Johns <chrisj@rtems.org>
0017  *
0018  * Redistribution and use in source and binary forms, with or without
0019  * modification, are permitted provided that the following conditions
0020  * are met:
0021  * 1. Redistributions of source code must retain the above copyright
0022  *    notice, this list of conditions and the following disclaimer.
0023  * 2. Redistributions in binary form must reproduce the above copyright
0024  *    notice, this list of conditions and the following disclaimer in the
0025  *    documentation and/or other materials provided with the distribution.
0026  *
0027  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0028  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0029  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0030  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0031  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0032  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0033  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0034  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0035  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0036  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0037  * POSSIBILITY OF SUCH DAMAGE.
0038  */
0039
0040
0041 #if !defined (_RTEMS_RFS_GROUP_H_)
0042 #define _RTEMS_RFS_GROUP_H_
0043
0044 /**
0045  * @ingroup rtems_rfs
0046  *
0047  * RTEMS File System Group Management
0048  */
0049 /**@{*/
0050
0051 #include <rtems/rfs/rtems-rfs-trace.h>
0052 #include <rtems/rfs/rtems-rfs-bitmaps.h>
0053 #include <rtems/rfs/rtems-rfs-buffer.h>
0054
0055 /**
0056  * Block allocations for a group on disk.
0057  */
0058 #define RTEMS_RFS_GROUP_BLOCK_BITMAP_BLOCK (0)
0059 #define RTEMS_RFS_GROUP_INODE_BITMAP_BLOCK (1)
0060 #define RTEMS_RFS_GROUP_INODE_BLOCK        (2)
0061
0062 /**
0063  * @brief Creates bit allocator for blocks in the group simpler.
0064  *
0065  * A group is a selection of blocks on the disk. Typically the number of blocks
0066  * in a group is determined by the number of bits a block holds. This makes the
0067  * bit allocator for blocks in the group simpler plus is allows a simple way to
0068  * localise access to files and directories.
0069  */
0070 typedef struct _rtems_rfs_group
0071 {
0072   /**
0073    * Base block number.
0074    */
0075   rtems_rfs_buffer_block base;
0076
0077   /**
0078    * The number of blocks in the group. Groups may be different sizes.
0079    */
0080   size_t size;
0081
0082   /**
0083    * The block bitmap control.
0084    */
0085   rtems_rfs_bitmap_control block_bitmap;
0086
0087   /**
0088    * The handle to the block bitmap buffer.
0089    */
0090   rtems_rfs_buffer_handle block_bitmap_buffer;
0091
0092   /**
0093    * The inode bitmap control.
0094    */
0095   rtems_rfs_bitmap_control inode_bitmap;
0096
0097   /**
0098    * The handle to the inode bitmap buffer.
0099    */
0100   rtems_rfs_buffer_handle inode_bitmap_buffer;
0101
0102 } rtems_rfs_group;
0103
0104 /**
0105  * Return the disk's block for a block in a group.
0106  */
0107 #define rtems_rfs_group_block(_g, _b) (((_g)->base) + (_b))
0108
0109 /**
0110  * Return the file system inode for a inode in a group.
0111  */
0112 #define rtems_rfs_group_inode(_f, _g, _i) \
0113   (((_f)->group_inodes * (_g)) + (_i) + RTEMS_RFS_ROOT_INO)
0114
0115 /**
0116  * @brief Open a group.
0117  *
0118  * Allocate all the resources including the bitmaps.
0119  *
0120  * @param fs The file system.
0121  * @param base The base block number.
0122  * @param size The number of blocks in the group.
0123  * @param group Reference to the group to open.
0124  * @retval int The error number (errno). No error if 0.
0125  */
0126 int rtems_rfs_group_open (rtems_rfs_file_system* fs,
0127                           rtems_rfs_buffer_block base,
0128                           size_t                 size,
0129                           size_t                 inodes,
0130                           rtems_rfs_group*       group);
0131
0132 /**
0133  * @brief Close a group.
0134  *
0135  * Release all resources the group holds.
0136  *
0137  * @param fs The file system.
0138  * @param group The group to close.
0139  * @retval int The error number (errno). No error if 0.
0140  */
0141 int rtems_rfs_group_close (rtems_rfs_file_system* fs,
0142                            rtems_rfs_group*       group);
0143
0144 /**
0145  * @brief Allocate an inode or block.
0146  *
0147  * The groups are searched to find the next
0148  * available inode or block.
0149  *
0150  * @param fs The file system data.
0151  * @param goal The goal to seed the bitmap search.
0152  * @param inode If true allocate an inode else allocate a block.
0153  * @param result The allocated bit in the bitmap.
0154  * @retval int The error number (errno). No error if 0.
0155  */
0156 int rtems_rfs_group_bitmap_alloc (rtems_rfs_file_system* fs,
0157                                   rtems_rfs_bitmap_bit   goal,
0158                                   bool                   inode,
0159                                   rtems_rfs_bitmap_bit*  result);
0160
0161 /**
0162  * @brief Free the group allocated bit.
0163  *
0164  * @param fs The file system data.
0165  * @param inode If true the number to free is an inode else it is a block.
0166  * @param block The inode or block number to free.
0167  * @retval int The error number (errno). No error if 0.
0168  */
0169 int rtems_rfs_group_bitmap_free (rtems_rfs_file_system* fs,
0170                                  bool                   inode,
0171                                  rtems_rfs_bitmap_bit   no);
0172
0173 /**
0174  * @brief Test the group allocated bit.
0175  *
0176  * @param fs The file system data.
0177  * @param inode If true the number to free is an inode else it is a block.
0178  * @param block The inode or block number to free.
0179  * @param state Return the state of the bit.
0180  * @retval int The error number (errno). No error if 0.
0181  */
0182 int rtems_rfs_group_bitmap_test (rtems_rfs_file_system* fs,
0183                                  bool                   inode,
0184                                  rtems_rfs_bitmap_bit   no,
0185                                  bool*                  state);
0186
0187 /**
0188  * @brief Determine the number of blocks and inodes used.
0189  *
0190  * @param fs The file system data.
0191  * @param blocks The number of blocks used.
0192  * @param inodes The number of inodes used.
0193  * @retval int The error number (errno). No error if 0.
0194  */
0195 int rtems_rfs_group_usage (rtems_rfs_file_system* fs,
0196                            size_t*                blocks,
0197                            size_t*                inodes);
0198
0199 /** @} */
0200 #endif