[linux.git] / fs / qnx4 / bitmap.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/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>

#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
Commit	Line	Data
1da177e4 LT	1	/*
	2	* QNX4 file system, Linux implementation.
	3	*
	4	* Version : 0.2.1
	5	*
	6	* Using parts of the xiafs filesystem.
	7	*
	8	* History :
	9	*
	10	* 28-05-1998 by Richard Frowijn : first release.
	11	* 20-06-1998 by Frank Denis : basic optimisations.
	12	* 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
	13	* 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
	14	*/
	15
1da177e4 LT	16	#include <linux/time.h>
	17	#include <linux/fs.h>
	18	#include <linux/qnx4_fs.h>
	19	#include <linux/stat.h>
	20	#include <linux/kernel.h>
	21	#include <linux/string.h>
	22	#include <linux/buffer_head.h>
	23	#include <linux/bitops.h>
	24
7a1119b1	25	#if 0
1da177e4 LT	26	int qnx4_new_block(struct super_block *sb)
	27	{
	28	return 0;
	29	}
7a1119b1	30	#endif /* 0 */
1da177e4 LT	31
	32	static void count_bits(register const char *bmPart, register int size,
	33	int *const tf)
	34	{
	35	char b;
	36	int tot = *tf;
	37
	38	if (size > QNX4_BLOCK_SIZE) {
	39	size = QNX4_BLOCK_SIZE;
	40	}
	41	do {
	42	b = *bmPart++;
	43	if ((b & 1) == 0)
	44	tot++;
	45	if ((b & 2) == 0)
	46	tot++;
	47	if ((b & 4) == 0)
	48	tot++;
	49	if ((b & 8) == 0)
	50	tot++;
	51	if ((b & 16) == 0)
	52	tot++;
	53	if ((b & 32) == 0)
	54	tot++;
	55	if ((b & 64) == 0)
	56	tot++;
	57	if ((b & 128) == 0)
	58	tot++;
	59	size--;
	60	} while (size != 0);
	61	*tf = tot;
	62	}
	63
	64	unsigned long qnx4_count_free_blocks(struct super_block *sb)
	65	{
	66	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
	67	int total = 0;
	68	int total_free = 0;
	69	int offset = 0;
	70	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
	71	struct buffer_head *bh;
	72
	73	while (total < size) {
	74	if ((bh = sb_bread(sb, start + offset)) == NULL) {
	75	printk("qnx4: I/O error in counting free blocks\n");
	76	break;
	77	}
	78	count_bits(bh->b_data, size - total, &total_free);
	79	brelse(bh);
	80	total += QNX4_BLOCK_SIZE;
	81	offset++;
	82	}
	83
	84	return total_free;
	85	}
	86
	87	#ifdef CONFIG_QNX4FS_RW
	88
	89	int qnx4_is_free(struct super_block *sb, long block)
	90	{
	91	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
	92	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
	93	struct buffer_head *bh;
	94	const char *g;
95	int ret = -EIO;
96
97	start += block / (QNX4_BLOCK_SIZE * 8);
98	QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n",
99	(unsigned long) block, (unsigned long) start));
100	(void) size; /* CHECKME */
101	bh = sb_bread(sb, start);
102	if (bh == NULL) {
103	return -EIO;
104	}
105	g = bh->b_data + (block % QNX4_BLOCK_SIZE);
106	if (((*g) & (1 << (block % 8))) == 0) {
107	QNX4DEBUG(("qnx4: is_free -> block is free\n"));
108	ret = 1;
109	} else {
110	QNX4DEBUG(("qnx4: is_free -> block is busy\n"));
111	ret = 0;
112	}
113	brelse(bh);
114
115	return ret;
116	}
117
118	int qnx4_set_bitmap(struct super_block *sb, long block, int busy)
119	{
120	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
121	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
122	struct buffer_head *bh;
123	char *g;
124
125	start += block / (QNX4_BLOCK_SIZE * 8);
126	QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n",
127	(unsigned long) block, (unsigned long) start));
128	(void) size; /* CHECKME */
129	bh = sb_bread(sb, start);
130	if (bh == NULL) {
131	return -EIO;
132	}
133	g = bh->b_data + (block % QNX4_BLOCK_SIZE);
134	if (busy == 0) {
135	(*g) &= ~(1 << (block % 8));
136	} else {
137	(*g) \|= (1 << (block % 8));
138	}
139	mark_buffer_dirty(bh);
140	brelse(bh);
141
142	return 0;
143	}
144
145	static void qnx4_clear_inode(struct inode *inode)
146	{
147	struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode);
148	/* What for? */
149	memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname);
150	qnx4_ino->di_size = 0;
151	qnx4_ino->di_num_xtnts = 0;
152	qnx4_ino->di_mode = 0;
153	qnx4_ino->di_status = 0;
154	}
155
156	void qnx4_free_inode(struct inode *inode)
157	{
158	if (inode->i_ino < 1) {
159	printk("free_inode: inode 0 or nonexistent inode\n");
160	return;
161	}
162	qnx4_clear_inode(inode);
163	clear_inode(inode);
164	}
165
166	#endif