166 строки
3.6 KiB
C
166 строки
3.6 KiB
C
/*
|
|
* 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/config.h>
|
|
#include <linux/time.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/qnx4_fs.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/bitops.h>
|
|
|
|
int qnx4_new_block(struct super_block *sb)
|
|
{
|
|
return 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
|