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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"
#define SBSIZE (sizeof (struct ext2_super_block))
void
get_hypermetadata (void)
{
sblock = malloc (SBSIZE);
disk_sblock = baddr(1);
assert (!diskfs_catch_exception ());
bcopy (disk_sblock, sblock, SBSIZE);
diskfs_end_catch_exception ();
if (sblock->s_magic != EXT2_SUPER_MAGIC
#ifdef EXT2FS_PRE_02B_COMPAT
&& sblock->s_magic != EXT2_PRE_02B_MAGIC
#endif
)
ext2_panic("Bad magic number %#lx (should be %#x)",
sblock->s_magic, EXT2_SUPER_MAGIC);
block_size = EXT2_MIN_BLOCK_SIZE << sblock->s_log_block_size;
if (block_size != BLOCK_SIZE
&& (sb->s_block_size == 1024 || sb->s_block_size == 2048
|| sb->s_block_size == 4096))
{
int offset = (sb_block_num * BLOCK_SIZE) % block_size;
unsigned long logical_sb_block_num =
(sb_block_num * BLOCK_SIZE) / block_size;
disk_sblock = baddr(logical_sb_block_num) + offset;
assert (!diskfs_catch_exception ());
bcopy (disk_sblock, sblock, SBSIZE);
diskfs_end_catch_exception ();
if (sblock->s_magic != EXT2_SUPER_MAGIC)
ext2_panic("Bad magic number %#lx (should be %#x)"
" in logical superblock!",
sblock->s_magic, EXT2_SUPER_MAGIC);
}
if (block_size > 8192)
ext2_panic("Block size %ld is too big (max is 8192 bytes)", block_size);
if (block_size < SBSIZE)
ext2_panic ("Block size %ld is too small (min is %ld bytes)",
block_size, SBSIZE);
assert ((vm_page_size % DEV_BSIZE) == 0);
assert ((sblock->fs_bsize % DEV_BSIZE) == 0);
assert (vm_page_size <= sblock->fs_bsize);
}
/* Write the csum data. This isn't backed by a pager because it is
taken from ordinary data blocks and might not be an even number
of pages; in that case writing it through the pager would nuke whatever
pages came after it on the disk and were backed by file pagers. */
void
diskfs_set_hypermetadata (int wait, int clean)
{
#if 0
vm_address_t buf;
vm_size_t bufsize;
error_t err;
spin_lock (&alloclock);
if (!csum_dirty)
{
spin_unlock (&alloclock);
return;
}
/* Copy into a page-aligned buffer to avoid bugs in kernel device code. */
bufsize = round_page (fragroundup (sblock, sblock->fs_cssize));
err = dev_read_sync (fsbtodb (sblock, sblock->fs_csaddr), &buf, bufsize);
if (!err)
{
bcopy (csum, (void *) buf, sblock->fs_cssize);
dev_write_sync (fsbtodb (sblock, sblock->fs_csaddr), buf, bufsize);
csum_dirty = 0;
vm_deallocate (mach_task_self (), buf, bufsize);
}
spin_unlock (&alloclock);
#endif
}
/* Copy the sblock into the disk */
void
copy_sblock ()
{
int clean = 1; /* XXX wrong... */
assert (!diskfs_catch_exception ());
spin_lock (&alloclock);
if (clean && !diskfs_readonly)
{
sblock->s_state |= EXT2_VALID_FS;
sblock_dirty = 1;
}
if (sblock_dirty)
{
bcopy (sblock, disk_sblock, SBSIZE);
record_poke (disk_sblock, SBSIZE);
sblock_dirty = 0;
}
if (clean && !diskfs_readonly)
{
sblock->s_state &= ~EXT2_VALID_FS;
sblock_dirty = 1;
}
spin_unlock (&alloclock);
diskfs_end_catch_exception ();
}
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