[net-next-2.6.git] / fs / minix / bitmap.c

/*
 *  linux/fs/minix/bitmap.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * Modified for 680x0 by Hamish Macdonald
 * Fixed for 680x0 by Andreas Schwab
 */

/* bitmap.c contains the code that handles the inode and block bitmaps */

#include "minix.h"
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/bitops.h>

static int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };

static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
{
	unsigned i, j, sum = 0;
	struct buffer_head *bh;
  
	for (i=0; i<numblocks-1; i++) {
		if (!(bh=map[i])) 
			return(0);
		for (j=0; j<bh->b_size; j++)
			sum += nibblemap[bh->b_data[j] & 0xf]
				+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	}

	if (numblocks==0 || !(bh=map[numblocks-1]))
		return(0);
	i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2;
	for (j=0; j<i; j++) {
		sum += nibblemap[bh->b_data[j] & 0xf]
			+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	}

	i = numbits%16;
	if (i!=0) {
		i = *(__u16 *)(&bh->b_data[j]) | ~((1<<i) - 1);
		sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
		sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
	}
	return(sum);
}

void minix_free_block(struct inode *inode, unsigned long block)
{
	struct super_block *sb = inode->i_sb;
	struct minix_sb_info *sbi = minix_sb(sb);
	struct buffer_head *bh;
	int k = sb->s_blocksize_bits + 3;
	unsigned long bit, zone;

	if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
		printk("Trying to free block not in datazone\n");
		return;
	}
	zone = block - sbi->s_firstdatazone + 1;
	bit = zone & ((1<<k) - 1);
	zone >>= k;
	if (zone >= sbi->s_zmap_blocks) {
		printk("minix_free_block: nonexistent bitmap buffer\n");
		return;
	}
	bh = sbi->s_zmap[zone];
	lock_kernel();
	if (!minix_test_and_clear_bit(bit, bh->b_data))
		printk("minix_free_block (%s:%lu): bit already cleared\n",
		       sb->s_id, block);
	unlock_kernel();
	mark_buffer_dirty(bh);
	return;
}

int minix_new_block(struct inode * inode)
{
	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	int bits_per_zone = 8 * inode->i_sb->s_blocksize;
	int i;

	for (i = 0; i < sbi->s_zmap_blocks; i++) {
		struct buffer_head *bh = sbi->s_zmap[i];
		int j;

		lock_kernel();
		j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
		if (j < bits_per_zone) {
			minix_set_bit(j, bh->b_data);
			unlock_kernel();
			mark_buffer_dirty(bh);
			j += i * bits_per_zone + sbi->s_firstdatazone-1;
			if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
				break;
			return j;
		}
		unlock_kernel();
	}
	return 0;
}

unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
{
	return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
		sbi->s_nzones - sbi->s_firstdatazone + 1)
		<< sbi->s_log_zone_size);
}

struct minix_inode *
minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
{
	int block;
	struct minix_sb_info *sbi = minix_sb(sb);
	struct minix_inode *p;

	if (!ino || ino > sbi->s_ninodes) {
		printk("Bad inode number on dev %s: %ld is out of range\n",
		       sb->s_id, (long)ino);
		return NULL;
	}
	ino--;
	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
		 ino / MINIX_INODES_PER_BLOCK;
	*bh = sb_bread(sb, block);
	if (!*bh) {
		printk("Unable to read inode block\n");
		return NULL;
	}
	p = (void *)(*bh)->b_data;
	return p + ino % MINIX_INODES_PER_BLOCK;
}

struct minix2_inode *
minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
{
	int block;
	struct minix_sb_info *sbi = minix_sb(sb);
	struct minix2_inode *p;
	int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);

	*bh = NULL;
	if (!ino || ino > sbi->s_ninodes) {
		printk("Bad inode number on dev %s: %ld is out of range\n",
		       sb->s_id, (long)ino);
		return NULL;
	}
	ino--;
	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
		 ino / minix2_inodes_per_block;
	*bh = sb_bread(sb, block);
	if (!*bh) {
		printk("Unable to read inode block\n");
		return NULL;
	}
	p = (void *)(*bh)->b_data;
	return p + ino % minix2_inodes_per_block;
}

/* Clear the link count and mode of a deleted inode on disk. */

static void minix_clear_inode(struct inode *inode)
{
	struct buffer_head *bh = NULL;

	if (INODE_VERSION(inode) == MINIX_V1) {
		struct minix_inode *raw_inode;
		raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
		if (raw_inode) {
			raw_inode->i_nlinks = 0;
			raw_inode->i_mode = 0;
		}
	} else {
		struct minix2_inode *raw_inode;
		raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
		if (raw_inode) {
			raw_inode->i_nlinks = 0;
			raw_inode->i_mode = 0;
		}
	}
	if (bh) {
		mark_buffer_dirty(bh);
		brelse (bh);
	}
}

void minix_free_inode(struct inode * inode)
{
	struct super_block *sb = inode->i_sb;
	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	struct buffer_head *bh;
	int k = sb->s_blocksize_bits + 3;
	unsigned long ino, bit;

	ino = inode->i_ino;
	if (ino < 1 || ino > sbi->s_ninodes) {
		printk("minix_free_inode: inode 0 or nonexistent inode\n");
		goto out;
	}
	bit = ino & ((1<<k) - 1);
	ino >>= k;
	if (ino >= sbi->s_imap_blocks) {
		printk("minix_free_inode: nonexistent imap in superblock\n");
		goto out;
	}

	minix_clear_inode(inode);	/* clear on-disk copy */

	bh = sbi->s_imap[ino];
	lock_kernel();
	if (!minix_test_and_clear_bit(bit, bh->b_data))
		printk("minix_free_inode: bit %lu already cleared\n", bit);
	unlock_kernel();
	mark_buffer_dirty(bh);
 out:
	clear_inode(inode);		/* clear in-memory copy */
}

struct inode * minix_new_inode(const struct inode * dir, int * error)
{
	struct super_block *sb = dir->i_sb;
	struct minix_sb_info *sbi = minix_sb(sb);
	struct inode *inode = new_inode(sb);
	struct buffer_head * bh;
	int bits_per_zone = 8 * sb->s_blocksize;
	unsigned long j;
	int i;

	if (!inode) {
		*error = -ENOMEM;
		return NULL;
	}
	j = bits_per_zone;
	bh = NULL;
	*error = -ENOSPC;
	lock_kernel();
	for (i = 0; i < sbi->s_imap_blocks; i++) {
		bh = sbi->s_imap[i];
		j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
		if (j < bits_per_zone)
			break;
	}
	if (!bh || j >= bits_per_zone) {
		unlock_kernel();
		iput(inode);
		return NULL;
	}
	if (minix_test_and_set_bit(j, bh->b_data)) {	/* shouldn't happen */
		unlock_kernel();
		printk("minix_new_inode: bit already set\n");
		iput(inode);
		return NULL;
	}
	unlock_kernel();
	mark_buffer_dirty(bh);
	j += i * bits_per_zone;
	if (!j || j > sbi->s_ninodes) {
		iput(inode);
		return NULL;
	}
	inode->i_uid = current->fsuid;
	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	inode->i_ino = j;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	inode->i_blocks = 0;
	memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
	insert_inode_hash(inode);
	mark_inode_dirty(inode);

	*error = 0;
	return inode;
}

unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
{
	return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/minix/bitmap.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
	7	/*
	8	* Modified for 680x0 by Hamish Macdonald
	9	* Fixed for 680x0 by Andreas Schwab
	10	*/
	11
	12	/* bitmap.c contains the code that handles the inode and block bitmaps */
	13
	14	#include "minix.h"
	15	#include <linux/smp_lock.h>
	16	#include <linux/buffer_head.h>
	17	#include <linux/bitops.h>
	18
	19	static int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };
	20
	21	static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
	22	{
	23	unsigned i, j, sum = 0;
	24	struct buffer_head *bh;
	25
	26	for (i=0; i<numblocks-1; i++) {
	27	if (!(bh=map[i]))
	28	return(0);
939b00df	29	for (j=0; j<bh->b_size; j++)
1da177e4 LT	30	sum += nibblemap[bh->b_data[j] & 0xf]
	31	+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	32	}
	33
	34	if (numblocks==0 \|\| !(bh=map[numblocks-1]))
	35	return(0);
939b00df	36	i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2;
1da177e4 LT	37	for (j=0; j<i; j++) {
	38	sum += nibblemap[bh->b_data[j] & 0xf]
	39	+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	40	}
	41
	42	i = numbits%16;
	43	if (i!=0) {
	44	i = (__u16 )(&bh->b_data[j]) \| ~((1<<i) - 1);
	45	sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
	46	sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
	47	}
	48	return(sum);
	49	}
	50
939b00df	51	void minix_free_block(struct inode *inode, unsigned long block)
1da177e4	52	{
939b00df AB	53	struct super_block *sb = inode->i_sb;
	54	struct minix_sb_info *sbi = minix_sb(sb);
	55	struct buffer_head *bh;
	56	int k = sb->s_blocksize_bits + 3;
	57	unsigned long bit, zone;
1da177e4 LT	58
1da177e4 LT	59	if (block < sbi->s_firstdatazone \|\| block >= sbi->s_nzones) {
11b84487	60	printk("Trying to free block not in datazone\n");
1da177e4 LT	61	return;
	62	}
	63	zone = block - sbi->s_firstdatazone + 1;
939b00df AB	64	bit = zone & ((1<<k) - 1);
939b00df AB	65	zone >>= k;
1da177e4 LT	66	if (zone >= sbi->s_zmap_blocks) {
	67	printk("minix_free_block: nonexistent bitmap buffer\n");
	68	return;
	69	}
	70	bh = sbi->s_zmap[zone];
	71	lock_kernel();
939b00df AB	72	if (!minix_test_and_clear_bit(bit, bh->b_data))
939b00df AB	73	printk("minix_free_block (%s:%lu): bit already cleared\n",
1da177e4 LT	74	sb->s_id, block);
	75	unlock_kernel();
	76	mark_buffer_dirty(bh);
	77	return;
	78	}
	79
	80	int minix_new_block(struct inode * inode)
	81	{
	82	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
939b00df	83	int bits_per_zone = 8 * inode->i_sb->s_blocksize;
1da177e4 LT	84	int i;
	85
	86	for (i = 0; i < sbi->s_zmap_blocks; i++) {
	87	struct buffer_head *bh = sbi->s_zmap[i];
	88	int j;
	89
	90	lock_kernel();
939b00df AB	91	j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
	92	if (j < bits_per_zone) {
	93	minix_set_bit(j, bh->b_data);
1da177e4 LT	94	unlock_kernel();
1da177e4 LT	95	mark_buffer_dirty(bh);
939b00df	96	j += i * bits_per_zone + sbi->s_firstdatazone-1;
1da177e4 LT	97	if (j < sbi->s_firstdatazone \|\| j >= sbi->s_nzones)
	98	break;
	99	return j;
	100	}
	101	unlock_kernel();
	102	}
	103	return 0;
	104	}
	105
	106	unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
	107	{
	108	return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
	109	sbi->s_nzones - sbi->s_firstdatazone + 1)
	110	<< sbi->s_log_zone_size);
	111	}
	112
	113	struct minix_inode *
	114	minix_V1_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	115	{
	116	int block;
	117	struct minix_sb_info *sbi = minix_sb(sb);
	118	struct minix_inode *p;
	119
	120	if (!ino \|\| ino > sbi->s_ninodes) {
	121	printk("Bad inode number on dev %s: %ld is out of range\n",
	122	sb->s_id, (long)ino);
	123	return NULL;
	124	}
	125	ino--;
	126	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
	127	ino / MINIX_INODES_PER_BLOCK;
	128	*bh = sb_bread(sb, block);
	129	if (!*bh) {
11b84487	130	printk("Unable to read inode block\n");
1da177e4 LT	131	return NULL;
	132	}
	133	p = (void )(bh)->b_data;
	134	return p + ino % MINIX_INODES_PER_BLOCK;
	135	}
	136
	137	struct minix2_inode *
	138	minix_V2_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	139	{
	140	int block;
	141	struct minix_sb_info *sbi = minix_sb(sb);
	142	struct minix2_inode *p;
939b00df	143	int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);
1da177e4 LT	144
	145	*bh = NULL;
	146	if (!ino \|\| ino > sbi->s_ninodes) {
	147	printk("Bad inode number on dev %s: %ld is out of range\n",
	148	sb->s_id, (long)ino);
	149	return NULL;
	150	}
	151	ino--;
	152	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
939b00df	153	ino / minix2_inodes_per_block;
1da177e4 LT	154	*bh = sb_bread(sb, block);
1da177e4 LT	155	if (!*bh) {
11b84487	156	printk("Unable to read inode block\n");
1da177e4 LT	157	return NULL;
	158	}
	159	p = (void )(bh)->b_data;
939b00df	160	return p + ino % minix2_inodes_per_block;
1da177e4 LT	161	}
	162
	163	/* Clear the link count and mode of a deleted inode on disk. */
	164
	165	static void minix_clear_inode(struct inode *inode)
	166	{
	167	struct buffer_head *bh = NULL;
	168
	169	if (INODE_VERSION(inode) == MINIX_V1) {
	170	struct minix_inode *raw_inode;
	171	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
	172	if (raw_inode) {
	173	raw_inode->i_nlinks = 0;
	174	raw_inode->i_mode = 0;
	175	}
	176	} else {
	177	struct minix2_inode *raw_inode;
	178	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
	179	if (raw_inode) {
	180	raw_inode->i_nlinks = 0;
	181	raw_inode->i_mode = 0;
	182	}
	183	}
	184	if (bh) {
	185	mark_buffer_dirty(bh);
	186	brelse (bh);
	187	}
	188	}
	189
	190	void minix_free_inode(struct inode * inode)
	191	{
939b00df	192	struct super_block *sb = inode->i_sb;
1da177e4	193	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
939b00df AB	194	struct buffer_head *bh;
	195	int k = sb->s_blocksize_bits + 3;
	196	unsigned long ino, bit;
1da177e4 LT	197
	198	ino = inode->i_ino;
	199	if (ino < 1 \|\| ino > sbi->s_ninodes) {
	200	printk("minix_free_inode: inode 0 or nonexistent inode\n");
	201	goto out;
	202	}
939b00df AB	203	bit = ino & ((1<<k) - 1);
	204	ino >>= k;
	205	if (ino >= sbi->s_imap_blocks) {
1da177e4 LT	206	printk("minix_free_inode: nonexistent imap in superblock\n");
	207	goto out;
	208	}
	209
	210	minix_clear_inode(inode); /* clear on-disk copy */
	211
939b00df	212	bh = sbi->s_imap[ino];
1da177e4	213	lock_kernel();
939b00df AB	214	if (!minix_test_and_clear_bit(bit, bh->b_data))
939b00df AB	215	printk("minix_free_inode: bit %lu already cleared\n", bit);
1da177e4 LT	216	unlock_kernel();
	217	mark_buffer_dirty(bh);
	218	out:
	219	clear_inode(inode); /* clear in-memory copy */
	220	}
	221
	222	struct inode * minix_new_inode(const struct inode * dir, int * error)
	223	{
	224	struct super_block *sb = dir->i_sb;
	225	struct minix_sb_info *sbi = minix_sb(sb);
	226	struct inode *inode = new_inode(sb);
	227	struct buffer_head * bh;
939b00df AB	228	int bits_per_zone = 8 * sb->s_blocksize;
	229	unsigned long j;
	230	int i;
1da177e4 LT	231
	232	if (!inode) {
	233	*error = -ENOMEM;
	234	return NULL;
	235	}
939b00df	236	j = bits_per_zone;
1da177e4 LT	237	bh = NULL;
	238	*error = -ENOSPC;
	239	lock_kernel();
	240	for (i = 0; i < sbi->s_imap_blocks; i++) {
	241	bh = sbi->s_imap[i];
939b00df AB	242	j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
939b00df AB	243	if (j < bits_per_zone)
1da177e4 LT	244	break;
1da177e4 LT	245	}
939b00df	246	if (!bh \|\| j >= bits_per_zone) {
1da177e4 LT	247	unlock_kernel();
	248	iput(inode);
	249	return NULL;
	250	}
939b00df	251	if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */
1da177e4	252	unlock_kernel();
939b00df	253	printk("minix_new_inode: bit already set\n");
1da177e4 LT	254	iput(inode);
	255	return NULL;
	256	}
	257	unlock_kernel();
	258	mark_buffer_dirty(bh);
939b00df	259	j += i * bits_per_zone;
1da177e4 LT	260	if (!j \|\| j > sbi->s_ninodes) {
	261	iput(inode);
	262	return NULL;
	263	}
	264	inode->i_uid = current->fsuid;
	265	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	266	inode->i_ino = j;
	267	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
ba52de12	268	inode->i_blocks = 0;
1da177e4 LT	269	memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
	270	insert_inode_hash(inode);
	271	mark_inode_dirty(inode);
	272
	273	*error = 0;
	274	return inode;
	275	}
	276
	277	unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
	278	{
	279	return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
	280	}