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/*
* QNX4 file system, Linux implementation.
*
* Version : 0.2.1
*
* Using parts of the xiafs filesystem.
*
* History :
*
* 28-05-1998 by Richard Frowijn : first release.
* 20-06-1998 by Frank Denis : basic optimisations.
* 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
* 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
*/
#include <linux/buffer_head.h>
#include <linux/bitops.h>
#include "qnx4.h"
#if 0
int qnx4_new_block(struct super_block *sb)
{
return 0;
}
#endif /* 0 */
static void count_bits(register const char *bmPart, register int size,
int *const tf)
{
char b;
int tot = *tf;
if (size > QNX4_BLOCK_SIZE) {
size = QNX4_BLOCK_SIZE;
}
do {
b = *bmPart++;
if ((b & 1) == 0)
tot++;
if ((b & 2) == 0)
tot++;
if ((b & 4) == 0)
tot++;
if ((b & 8) == 0)
tot++;
if ((b & 16) == 0)
tot++;
if ((b & 32) == 0)
tot++;
if ((b & 64) == 0)
tot++;
if ((b & 128) == 0)
tot++;
size--;
} while (size != 0);
*tf = tot;
}
unsigned long qnx4_count_free_blocks(struct super_block *sb)
{
int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
int total = 0;
int total_free = 0;
int offset = 0;
int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
struct buffer_head *bh;
while (total < size) {
if ((bh = sb_bread(sb, start + offset)) == NULL) {
printk("qnx4: I/O error in counting free blocks\n");
break;
}
count_bits(bh->b_data, size - total, &total_free);
brelse(bh);
total += QNX4_BLOCK_SIZE;
offset++;
}
return total_free;
}
#ifdef CONFIG_QNX4FS_RW
int qnx4_is_free(struct super_block *sb, long block)
{
int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
struct buffer_head *bh;
const char *g;
int ret = -EIO;
start += block / (QNX4_BLOCK_SIZE * 8);
QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n",
(unsigned long) block, (unsigned long) start));
(void) size; /* CHECKME */
bh = sb_bread(sb, start);
if (bh == NULL) {
return -EIO;
}
g = bh->b_data + (block % QNX4_BLOCK_SIZE);
if (((*g) & (1 << (block % 8))) == 0) {
QNX4DEBUG(("qnx4: is_free -> block is free\n"));
ret = 1;
} else {
QNX4DEBUG(("qnx4: is_free -> block is busy\n"));
ret = 0;
}
brelse(bh);
return ret;
}
int qnx4_set_bitmap(struct super_block *sb, long block, int busy)
{
int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
struct buffer_head *bh;
char *g;
start += block / (QNX4_BLOCK_SIZE * 8);
QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n",
(unsigned long) block, (unsigned long) start));
(void) size; /* CHECKME */
bh = sb_bread(sb, start);
if (bh == NULL) {
return -EIO;
}
g = bh->b_data + (block % QNX4_BLOCK_SIZE);
if (busy == 0) {
(*g) &= ~(1 << (block % 8));
} else {
(*g) |= (1 << (block % 8));
}
mark_buffer_dirty(bh);
brelse(bh);
return 0;
}
static void qnx4_clear_inode(struct inode *inode)
{
struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode);
/* What for? */
memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname);
qnx4_ino->di_size = 0;
qnx4_ino->di_num_xtnts = 0;
qnx4_ino->di_mode = 0;
qnx4_ino->di_status = 0;
}
void qnx4_free_inode(struct inode *inode)
{
if (inode->i_ino < 1) {
printk("free_inode: inode 0 or nonexistent inode\n");
return;
}
qnx4_clear_inode(inode);
clear_inode(inode);
}
#endif
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