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/* Fetching and storing the hypermetadata (superblock and bg summary info).
Copyright (C) 1994, 1995 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <string.h>
#include <stdio.h>
#include "ext2fs.h"
void
get_hypermetadata (void)
{
assert (!diskfs_catch_exception ());
sblock = boffs_ptr(SBLOCK_OFFS);
if (sblock->s_magic != EXT2_SUPER_MAGIC
#ifdef EXT2FS_PRE_02B_COMPAT
&& sblock->s_magic != EXT2_PRE_02B_MAGIC
#endif
)
ext2_panic("get_hypermetadata",
"Bad magic number %#x (should be %#x)",
sblock->s_magic, EXT2_SUPER_MAGIC);
block_size = EXT2_MIN_BLOCK_SIZE << sblock->s_log_block_size;
if (block_size > 8192)
ext2_panic("get_hypermetadata",
"Block size %ld is too big (max is 8192 bytes)", block_size);
if (block_size < SBLOCK_SIZE)
ext2_panic ("get_hypermetadata",
"Block size %ld is too small (min is %ld bytes)",
block_size, SBLOCK_SIZE);
log2_dev_blocks_per_fs_block = 0;
while ((device_block_size << log2_dev_blocks_per_fs_block) < block_size)
log2_dev_blocks_per_fs_block++;
if ((device_block_size << log2_dev_blocks_per_fs_block) != block_size)
ext2_panic("get_hypermetadata",
"Block size %ld isn't a power-of-two multiple of the device"
" block size (%d)!",
block_size, device_block_size);
log2_block_size = 0;
while ((1 << log2_block_size) < block_size)
log2_block_size++;
if ((1 << log2_block_size) != block_size)
ext2_panic("get_hypermetadata",
"Block size %ld isn't a power of two!", block_size);
/* Set these handy variables. */
inodes_per_block = block_size / sizeof (struct ext2_inode);
frag_size = EXT2_MIN_FRAG_SIZE << sblock->s_log_frag_size;
if (frag_size)
frags_per_block = block_size / frag_size;
else
ext2_panic("get_hypermetadata", "Frag size is zero!");
groups_count =
((sblock->s_blocks_count - sblock->s_first_data_block +
sblock->s_blocks_per_group - 1)
/ sblock->s_blocks_per_group);
itb_per_group = sblock->s_inodes_per_group / inodes_per_block;
desc_per_block = block_size / sizeof (struct ext2_group_desc);
addr_per_block = block_size / sizeof (u32);
db_per_group = (groups_count + desc_per_block - 1) / desc_per_block;
diskfs_end_catch_exception ();
}
void
diskfs_set_hypermetadata (int wait, int clean)
{
if (clean && !(sblock->s_state & EXT2_VALID_FS))
/* The filesystem is clean, so we need to set the clean flag. We
just write the superblock directly, without using the paged copy. */
{
struct ext2_super_block clean_sblock;
bcopy (sblock, clean_sblock, SBLOCK_SIZE);
clean_sblock->s_state |= EXT2_VALID_FS;
dev_write_sync (SBLOCK_OFFS / device_block_size,
(vm_address_t)clean_sblock, SBLOCK_SIZE);
}
}
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