/*
* alloc.c --- allocate new inodes, blocks for ext2fs
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <time.h>
#include <string.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
/*
* Check for uninit block bitmaps and deal with them appropriately
*/
static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
dgrp_t group)
{
blk_t i;
blk64_t blk, super_blk, old_desc_blk, new_desc_blk;
int old_desc_blocks;
if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
!(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
return;
blk = ext2fs_group_first_block2(fs, group);
ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
&old_desc_blk, &new_desc_blk, 0);
if (fs->super->s_feature_incompat &
EXT2_FEATURE_INCOMPAT_META_BG)
old_desc_blocks = fs->super->s_first_meta_bg;
else
old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
for (i=0; i < fs->super->s_blocks_per_group; i++, blk++)
ext2fs_fast_unmark_block_bitmap2(map, blk);
blk = ext2fs_group_first_block2(fs, group);
for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
if ((blk == super_blk) ||
(old_desc_blk && old_desc_blocks &&
(blk >= old_desc_blk) &&
(blk < old_desc_blk + old_desc_blocks)) ||
(new_desc_blk && (blk == new_desc_blk)) ||
(blk == ext2fs_block_bitmap_loc(fs, group)) ||
(blk == ext2fs_inode_bitmap_loc(fs, group)) ||
(blk >= ext2fs_inode_table_loc(fs, group) &&
(blk < ext2fs_inode_table_loc(fs, group)
+ fs->inode_blocks_per_group)))
ext2fs_fast_mark_block_bitmap2(map, blk);
}
ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
ext2fs_group_desc_csum_set(fs, group);
ext2fs_mark_super_dirty(fs);
ext2fs_mark_bb_dirty(fs);
}
/*
* Check for uninit inode bitmaps and deal with them appropriately
*/
static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
dgrp_t group)
{
ext2_ino_t i, ino;
if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
!(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
return;
ino = (group * fs->super->s_inodes_per_group) + 1;
for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
ext2fs_fast_unmark_inode_bitmap2(map, ino);
ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
ext2fs_group_desc_csum_set(fs, group);
ext2fs_mark_ib_dirty(fs);
ext2fs_mark_super_dirty(fs);
check_block_uninit(fs, fs->block_map, group);
}
/*
* Right now, just search forward from the parent directory's block
* group to find the next free inode.
*
* Should have a special policy for directories.
*/
errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
int mode EXT2FS_ATTR((unused)),
ext2fs_inode_bitmap map, ext2_ino_t *ret)
{
ext2_ino_t start_inode = 0;
ext2_ino_t i, ino_in_group, upto, first_zero;
errcode_t retval;
dgrp_t group;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->inode_map;
if (!map)
return EXT2_ET_NO_INODE_BITMAP;
if (dir > 0) {
group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
}
if (start_inode < EXT2_FIRST_INODE(fs->super))
start_inode = EXT2_FIRST_INODE(fs->super);
if (start_inode > fs->super->s_inodes_count)
return EXT2_ET_INODE_ALLOC_FAIL;
i = start_inode;
do {
ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super);
group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super);
check_inode_uninit(fs, map, group);
upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group);
if (i < start_inode && upto >= start_inode)
upto = start_inode - 1;
if (upto > fs->super->s_inodes_count)
upto = fs->super->s_inodes_count;
retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto,
&first_zero);
if (retval == 0) {
i = first_zero;
break;
}
if (retval != ENOENT)
return EXT2_ET_INODE_ALLOC_FAIL;
i = upto + 1;
if (i > fs->super->s_inodes_count)
i = EXT2_FIRST_INODE(fs->super);
} while (i != start_inode);
if (ext2fs_test_inode_bitmap2(map, i))
return EXT2_ET_INODE_ALLOC_FAIL;
*ret = i;
return 0;
}
/*
* Stupid algorithm --- we now just search forward starting from the
* goal. Should put in a smarter one someday....
*/
errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
ext2fs_block_bitmap map, blk64_t *ret)
{
blk64_t i;
int c_ratio;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
goal = fs->super->s_first_data_block;
i = goal;
c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
if (c_ratio > 1)
goal &= ~EXT2FS_CLUSTER_MASK(fs);
check_block_uninit(fs, map,
(i - fs->super->s_first_data_block) /
EXT2_BLOCKS_PER_GROUP(fs->super));
do {
if (((i - fs->super->s_first_data_block) %
EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
check_block_uninit(fs, map,
(i - fs->super->s_first_data_block) /
EXT2_BLOCKS_PER_GROUP(fs->super));
if (!ext2fs_fast_test_block_bitmap2(map, i)) {
*ret = i;
return 0;
}
i = (i + c_ratio) & ~(c_ratio - 1);
if (i >= ext2fs_blocks_count(fs->super))
i = fs->super->s_first_data_block;
} while (i != goal);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
ext2fs_block_bitmap map, blk_t *ret)
{
errcode_t retval;
blk64_t val;
retval = ext2fs_new_block2(fs, goal, map, &val);
if (!retval)
*ret = (blk_t) val;
return retval;
}
/*
* This function zeros out the allocated block, and updates all of the
* appropriate filesystem records.
*/
errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
char *block_buf, blk64_t *ret)
{
errcode_t retval;
blk64_t block;
char *buf = 0;
if (!block_buf) {
retval = ext2fs_get_mem(fs->blocksize, &buf);
if (retval)
return retval;
block_buf = buf;
}
memset(block_buf, 0, fs->blocksize);
if (fs->get_alloc_block) {
retval = (fs->get_alloc_block)(fs, goal, &block);
if (retval)
goto fail;
} else {
if (!fs->block_map) {
retval = ext2fs_read_block_bitmap(fs);
if (retval)
goto fail;
}
retval = ext2fs_new_block2(fs, goal, 0, &block);
if (retval)
goto fail;
}
retval = io_channel_write_blk64(fs->io, block, 1, block_buf);
if (retval)
goto fail;
ext2fs_block_alloc_stats2(fs, block, +1);
*ret = block;
fail:
if (buf)
ext2fs_free_mem(&buf);
return retval;
}
errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
char *block_buf, blk_t *ret)
{
errcode_t retval;
blk64_t val;
retval = ext2fs_alloc_block2(fs, goal, block_buf, &val);
if (!retval)
*ret = (blk_t) val;
return retval;
}
errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
int num, ext2fs_block_bitmap map, blk64_t *ret)
{
blk64_t b = start;
int c_ratio;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!b)
b = fs->super->s_first_data_block;
if (!finish)
finish = start;
if (!num)
num = 1;
c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
b &= ~(c_ratio - 1);
finish &= ~(c_ratio -1);
do {
if (b+num-1 > ext2fs_blocks_count(fs->super))
b = fs->super->s_first_data_block;
if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
*ret = b;
return 0;
}
b += c_ratio;
} while (b != finish);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
int num, ext2fs_block_bitmap map, blk_t *ret)
{
errcode_t retval;
blk64_t val;
retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val);
if(!retval)
*ret = (blk_t) val;
return retval;
}
void ext2fs_set_alloc_block_callback(ext2_filsys fs,
errcode_t (*func)(ext2_filsys fs,
blk64_t goal,
blk64_t *ret),
errcode_t (**old)(ext2_filsys fs,
blk64_t goal,
blk64_t *ret))
{
if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
return;
if (old)
*old = fs->get_alloc_block;
fs->get_alloc_block = func;
}