/**
* @file
*
* @brief RTEMS File Systems Group Routines
* @ingroup rtems_rfs
*
* These functions open and close a group as well as manage bit allocations
* within a group.
*/
/*
* 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 HAVE_CONFIG_H
#include "config.h"
#endif
#include <inttypes.h>
#include <string.h>
#include <rtems/rfs/rtems-rfs-file-system.h>
#include <rtems/rfs/rtems-rfs-group.h>
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)
{
int rc;
if (base >= rtems_rfs_fs_blocks (fs))
{
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: base outside file system range: %d: %s\n",
EIO, strerror (EIO));
return EIO;
}
if ((base + size) >= rtems_rfs_fs_blocks (fs))
size = rtems_rfs_fs_blocks (fs) - base;
/*
* Limit the inodes to the same size as the blocks. This is what the
* format does and if this is not done the accounting of inodes does
* not work. If we are so pushed for inodes that this makes a difference
* the format configuration needs reviewing.
*/
if (inodes > size)
inodes = size;
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: base=%" PRId32 ", blocks=%zd inodes=%zd\n",
base, size, inodes);
group->base = base;
group->size = size;
rc = rtems_rfs_buffer_handle_open (fs, &group->block_bitmap_buffer);
if (rc > 0)
{
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: could not open block bitmap handle: %d: %s\n",
rc, strerror (rc));
return rc;
}
rc = rtems_rfs_bitmap_open (&group->block_bitmap, fs,
&group->block_bitmap_buffer, size,
group->base + RTEMS_RFS_GROUP_BLOCK_BITMAP_BLOCK);
if (rc > 0)
{
rtems_rfs_buffer_handle_close (fs, &group->block_bitmap_buffer);
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: could not open block bitmap: %d: %s\n",
rc, strerror (rc));
return rc;
}
rc = rtems_rfs_buffer_handle_open (fs, &group->inode_bitmap_buffer);
if (rc > 0)
{
rtems_rfs_bitmap_close (&group->block_bitmap);
rtems_rfs_buffer_handle_close (fs, &group->block_bitmap_buffer);
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: could not open inode bitmap handle: %d: %s\n",
rc, strerror (rc));
return rc;
}
rc = rtems_rfs_bitmap_open (&group->inode_bitmap, fs,
&group->inode_bitmap_buffer, inodes,
group->base + RTEMS_RFS_GROUP_INODE_BITMAP_BLOCK);
if (rc > 0)
{
rtems_rfs_buffer_handle_close (fs, &group->inode_bitmap_buffer);
rtems_rfs_bitmap_close (&group->block_bitmap);
rtems_rfs_buffer_handle_close (fs, &group->block_bitmap_buffer);
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_OPEN))
printf ("rtems-rfs: group-open: could not open inode bitmap: %d: %s\n",
rc, strerror (rc));
return rc;
}
if (rtems_rfs_fs_release_bitmaps (fs))
{
rtems_rfs_bitmap_release_buffer (fs, &group->block_bitmap);
rtems_rfs_bitmap_release_buffer (fs, &group->inode_bitmap);
}
return 0;
}
int
rtems_rfs_group_close (rtems_rfs_file_system* fs, rtems_rfs_group* group)
{
int result = 0;
int rc;
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_CLOSE))
printf ("rtems-rfs: group-close: base=%" PRId32 "\n", group->base);
/*
* We need to close as much as possible and also return any error if one
* occurs but this may result in one even more important error being lost but
* we cannot OR the errors together so this is a reasonable compromise.
*/
rc = rtems_rfs_bitmap_close (&group->inode_bitmap);
if (rc > 0)
result = rc;
rc = rtems_rfs_buffer_handle_close (fs, &group->inode_bitmap_buffer);
if (rc > 0)
result = rc;
rc = rtems_rfs_bitmap_close (&group->block_bitmap);
if (rc > 0)
result = rc;
rc = rtems_rfs_buffer_handle_close (fs, &group->block_bitmap_buffer);
if (rc > 0)
result = rc;
return result;
}
int
rtems_rfs_group_bitmap_alloc (rtems_rfs_file_system* fs,
rtems_rfs_bitmap_bit goal,
bool inode,
rtems_rfs_bitmap_bit* result)
{
int group_start;
size_t size;
rtems_rfs_bitmap_bit bit;
int offset;
bool updown;
int direction;
if (inode)
{
size = fs->group_inodes;
goal -= RTEMS_RFS_ROOT_INO;
}
else
size = fs->group_blocks;
group_start = goal / size;
bit = (rtems_rfs_bitmap_bit) (goal % size);
offset = 0;
updown = true;
direction = 1;
/*
* Try the goal group first and if that group fails try the groups either
* side until the whole file system has be tried.
*/
while (true)
{
rtems_rfs_bitmap_control* bitmap;
int group;
bool allocated = false;
int rc;
/*
* We can start at any location and we move out from that point in each
* direction. The offset grows until we find a free bit or we hit an end.
*/
group = group_start + (direction * offset);
if (offset)
bit = direction > 0 ? 0 : size - 1;
/*
* If we are still looking up and down and if the group is out of range we
* have reached one end. Stopping looking up and down and just move in the
* one direction one group at a time.
*/
if ((group < 0) || (group >= fs->group_count))
{
if (!updown)
break;
direction = direction > 0 ? -1 : 1;
updown = false;
continue;
}
if (inode)
bitmap = &fs->groups[group].inode_bitmap;
else
bitmap = &fs->groups[group].block_bitmap;
rc = rtems_rfs_bitmap_map_alloc (bitmap, bit, &allocated, &bit);
if (rc > 0)
return rc;
if (rtems_rfs_fs_release_bitmaps (fs))
rtems_rfs_bitmap_release_buffer (fs, bitmap);
if (allocated)
{
if (inode)
*result = rtems_rfs_group_inode (fs, group, bit);
else
*result = rtems_rfs_group_block (&fs->groups[group], bit);
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_BITMAPS))
printf ("rtems-rfs: group-bitmap-alloc: %s allocated: %" PRId32 "\n",
inode ? "inode" : "block", *result);
return 0;
}
/*
* If we are still looking back and forth around the
* group_start, then alternate the direction and
* increment the offset on every other iteration.
* Otherwise we are marching through the groups, so just
* increment the offset.
*/
if (updown)
{
direction = direction > 0 ? -1 : 1;
if ( direction == -1 )
offset++;
}
else
{
offset++;
}
}
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_BITMAPS))
printf ("rtems-rfs: group-bitmap-alloc: no blocks available\n");
return ENOSPC;
}
int
rtems_rfs_group_bitmap_free (rtems_rfs_file_system* fs,
bool inode,
rtems_rfs_bitmap_bit no)
{
rtems_rfs_bitmap_control* bitmap;
unsigned int group;
rtems_rfs_bitmap_bit bit;
size_t size;
int rc;
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_BITMAPS))
printf ("rtems-rfs: group-bitmap-free: %s free: %" PRId32 "\n",
inode ? "inode" : "block", no);
if (inode)
{
no -= RTEMS_RFS_ROOT_INO;
size = fs->group_inodes;
}
else
{
no -= RTEMS_RFS_SUPERBLOCK_SIZE;
size = fs->group_blocks;
}
group = no / size;
bit = (rtems_rfs_bitmap_bit) (no % size);
if (inode)
bitmap = &fs->groups[group].inode_bitmap;
else
bitmap = &fs->groups[group].block_bitmap;
rc = rtems_rfs_bitmap_map_clear (bitmap, bit);
rtems_rfs_bitmap_release_buffer (fs, bitmap);
return rc;
}
int
rtems_rfs_group_bitmap_test (rtems_rfs_file_system* fs,
bool inode,
rtems_rfs_bitmap_bit no,
bool* state)
{
rtems_rfs_bitmap_control* bitmap;
unsigned int group;
rtems_rfs_bitmap_bit bit;
size_t size;
int rc;
if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_BITMAPS))
printf ("rtems-rfs: group-bitmap-test: %s test: %" PRId32 "\n",
inode ? "inode" : "block", no);
if (inode)
{
if ((no < RTEMS_RFS_ROOT_INO) || (no > rtems_rfs_fs_inodes (fs)))
return EINVAL;
no -= RTEMS_RFS_ROOT_INO;
size = fs->group_inodes;
}
else
{
if (no >= rtems_rfs_fs_blocks (fs))
return EINVAL;
size = fs->group_blocks;
}
group = no / size;
bit = (rtems_rfs_bitmap_bit) (no % size);
if (inode)
bitmap = &fs->groups[group].inode_bitmap;
else
bitmap = &fs->groups[group].block_bitmap;
rc = rtems_rfs_bitmap_map_test (bitmap, bit, state);
rtems_rfs_bitmap_release_buffer (fs, bitmap);
return rc;
}
int
rtems_rfs_group_usage (rtems_rfs_file_system* fs,
size_t* blocks,
size_t* inodes)
{
int g;
*blocks = 0;
*inodes = 0;
for (g = 0; g < fs->group_count; g++)
{
rtems_rfs_group* group = &fs->groups[g];
*blocks +=
rtems_rfs_bitmap_map_size(&group->block_bitmap) -
rtems_rfs_bitmap_map_free (&group->block_bitmap);
*inodes +=
rtems_rfs_bitmap_map_size (&group->inode_bitmap) -
rtems_rfs_bitmap_map_free (&group->inode_bitmap);
}
if (*blocks > rtems_rfs_fs_blocks (fs))
*blocks = rtems_rfs_fs_blocks (fs);
if (*inodes > rtems_rfs_fs_inodes (fs))
*inodes = rtems_rfs_fs_inodes (fs);
return 0;
}
