[linux.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>
#include <linux/sched.h>

static const 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>
e8edc6e0	18	#include <linux/sched.h>
1da177e4	19
febfcf91	20	static const int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };
1da177e4 LT	21
	22	static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
	23	{
	24	unsigned i, j, sum = 0;
	25	struct buffer_head *bh;
	26
	27	for (i=0; i<numblocks-1; i++) {
	28	if (!(bh=map[i]))
	29	return(0);
939b00df	30	for (j=0; j<bh->b_size; j++)
1da177e4 LT	31	sum += nibblemap[bh->b_data[j] & 0xf]
	32	+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	33	}
	34
	35	if (numblocks==0 \|\| !(bh=map[numblocks-1]))
	36	return(0);
939b00df	37	i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2;
1da177e4 LT	38	for (j=0; j<i; j++) {
	39	sum += nibblemap[bh->b_data[j] & 0xf]
	40	+ nibblemap[(bh->b_data[j]>>4) & 0xf];
	41	}
	42
	43	i = numbits%16;
	44	if (i!=0) {
	45	i = (__u16 )(&bh->b_data[j]) \| ~((1<<i) - 1);
	46	sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
	47	sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
	48	}
	49	return(sum);
	50	}
	51
939b00df	52	void minix_free_block(struct inode *inode, unsigned long block)
1da177e4	53	{
939b00df AB	54	struct super_block *sb = inode->i_sb;
	55	struct minix_sb_info *sbi = minix_sb(sb);
	56	struct buffer_head *bh;
	57	int k = sb->s_blocksize_bits + 3;
	58	unsigned long bit, zone;
1da177e4 LT	59
1da177e4 LT	60	if (block < sbi->s_firstdatazone \|\| block >= sbi->s_nzones) {
11b84487	61	printk("Trying to free block not in datazone\n");
1da177e4 LT	62	return;
	63	}
	64	zone = block - sbi->s_firstdatazone + 1;
939b00df AB	65	bit = zone & ((1<<k) - 1);
939b00df AB	66	zone >>= k;
1da177e4 LT	67	if (zone >= sbi->s_zmap_blocks) {
	68	printk("minix_free_block: nonexistent bitmap buffer\n");
	69	return;
	70	}
	71	bh = sbi->s_zmap[zone];
	72	lock_kernel();
939b00df AB	73	if (!minix_test_and_clear_bit(bit, bh->b_data))
939b00df AB	74	printk("minix_free_block (%s:%lu): bit already cleared\n",
1da177e4 LT	75	sb->s_id, block);
	76	unlock_kernel();
	77	mark_buffer_dirty(bh);
	78	return;
	79	}
	80
	81	int minix_new_block(struct inode * inode)
	82	{
	83	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
939b00df	84	int bits_per_zone = 8 * inode->i_sb->s_blocksize;
1da177e4 LT	85	int i;
	86
	87	for (i = 0; i < sbi->s_zmap_blocks; i++) {
	88	struct buffer_head *bh = sbi->s_zmap[i];
	89	int j;
	90
	91	lock_kernel();
939b00df AB	92	j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
	93	if (j < bits_per_zone) {
	94	minix_set_bit(j, bh->b_data);
1da177e4 LT	95	unlock_kernel();
1da177e4 LT	96	mark_buffer_dirty(bh);
939b00df	97	j += i * bits_per_zone + sbi->s_firstdatazone-1;
1da177e4 LT	98	if (j < sbi->s_firstdatazone \|\| j >= sbi->s_nzones)
	99	break;
	100	return j;
	101	}
	102	unlock_kernel();
	103	}
	104	return 0;
	105	}
	106
	107	unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
	108	{
	109	return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
	110	sbi->s_nzones - sbi->s_firstdatazone + 1)
	111	<< sbi->s_log_zone_size);
	112	}
	113
	114	struct minix_inode *
	115	minix_V1_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	116	{
	117	int block;
	118	struct minix_sb_info *sbi = minix_sb(sb);
	119	struct minix_inode *p;
	120
	121	if (!ino \|\| ino > sbi->s_ninodes) {
	122	printk("Bad inode number on dev %s: %ld is out of range\n",
	123	sb->s_id, (long)ino);
	124	return NULL;
	125	}
	126	ino--;
	127	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
	128	ino / MINIX_INODES_PER_BLOCK;
	129	*bh = sb_bread(sb, block);
	130	if (!*bh) {
11b84487	131	printk("Unable to read inode block\n");
1da177e4 LT	132	return NULL;
	133	}
	134	p = (void )(bh)->b_data;
	135	return p + ino % MINIX_INODES_PER_BLOCK;
	136	}
	137
	138	struct minix2_inode *
	139	minix_V2_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	140	{
	141	int block;
	142	struct minix_sb_info *sbi = minix_sb(sb);
	143	struct minix2_inode *p;
939b00df	144	int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);
1da177e4 LT	145
	146	*bh = NULL;
	147	if (!ino \|\| ino > sbi->s_ninodes) {
	148	printk("Bad inode number on dev %s: %ld is out of range\n",
	149	sb->s_id, (long)ino);
	150	return NULL;
	151	}
	152	ino--;
	153	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
939b00df	154	ino / minix2_inodes_per_block;
1da177e4 LT	155	*bh = sb_bread(sb, block);
1da177e4 LT	156	if (!*bh) {
11b84487	157	printk("Unable to read inode block\n");
1da177e4 LT	158	return NULL;
	159	}
	160	p = (void )(bh)->b_data;
939b00df	161	return p + ino % minix2_inodes_per_block;
1da177e4 LT	162	}
	163
	164	/* Clear the link count and mode of a deleted inode on disk. */
	165
	166	static void minix_clear_inode(struct inode *inode)
	167	{
	168	struct buffer_head *bh = NULL;
	169
	170	if (INODE_VERSION(inode) == MINIX_V1) {
	171	struct minix_inode *raw_inode;
	172	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
	173	if (raw_inode) {
	174	raw_inode->i_nlinks = 0;
	175	raw_inode->i_mode = 0;
	176	}
	177	} else {
	178	struct minix2_inode *raw_inode;
	179	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
	180	if (raw_inode) {
	181	raw_inode->i_nlinks = 0;
	182	raw_inode->i_mode = 0;
	183	}
	184	}
	185	if (bh) {
	186	mark_buffer_dirty(bh);
	187	brelse (bh);
	188	}
	189	}
	190
	191	void minix_free_inode(struct inode * inode)
	192	{
939b00df	193	struct super_block *sb = inode->i_sb;
1da177e4	194	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
939b00df AB	195	struct buffer_head *bh;
	196	int k = sb->s_blocksize_bits + 3;
	197	unsigned long ino, bit;
1da177e4 LT	198
	199	ino = inode->i_ino;
	200	if (ino < 1 \|\| ino > sbi->s_ninodes) {
	201	printk("minix_free_inode: inode 0 or nonexistent inode\n");
	202	goto out;
	203	}
939b00df AB	204	bit = ino & ((1<<k) - 1);
	205	ino >>= k;
	206	if (ino >= sbi->s_imap_blocks) {
1da177e4 LT	207	printk("minix_free_inode: nonexistent imap in superblock\n");
	208	goto out;
	209	}
	210
	211	minix_clear_inode(inode); /* clear on-disk copy */
	212
939b00df	213	bh = sbi->s_imap[ino];
1da177e4	214	lock_kernel();
939b00df AB	215	if (!minix_test_and_clear_bit(bit, bh->b_data))
939b00df AB	216	printk("minix_free_inode: bit %lu already cleared\n", bit);
1da177e4 LT	217	unlock_kernel();
	218	mark_buffer_dirty(bh);
	219	out:
	220	clear_inode(inode); /* clear in-memory copy */
	221	}
	222
	223	struct inode * minix_new_inode(const struct inode * dir, int * error)
	224	{
	225	struct super_block *sb = dir->i_sb;
	226	struct minix_sb_info *sbi = minix_sb(sb);
	227	struct inode *inode = new_inode(sb);
	228	struct buffer_head * bh;
939b00df AB	229	int bits_per_zone = 8 * sb->s_blocksize;
	230	unsigned long j;
	231	int i;
1da177e4 LT	232
	233	if (!inode) {
	234	*error = -ENOMEM;
	235	return NULL;
	236	}
939b00df	237	j = bits_per_zone;
1da177e4 LT	238	bh = NULL;
	239	*error = -ENOSPC;
	240	lock_kernel();
	241	for (i = 0; i < sbi->s_imap_blocks; i++) {
	242	bh = sbi->s_imap[i];
939b00df AB	243	j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
939b00df AB	244	if (j < bits_per_zone)
1da177e4 LT	245	break;
1da177e4 LT	246	}
939b00df	247	if (!bh \|\| j >= bits_per_zone) {
1da177e4 LT	248	unlock_kernel();
	249	iput(inode);
	250	return NULL;
	251	}
939b00df	252	if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */
1da177e4	253	unlock_kernel();
939b00df	254	printk("minix_new_inode: bit already set\n");
1da177e4 LT	255	iput(inode);
	256	return NULL;
	257	}
	258	unlock_kernel();
	259	mark_buffer_dirty(bh);
939b00df	260	j += i * bits_per_zone;
1da177e4 LT	261	if (!j \|\| j > sbi->s_ninodes) {
	262	iput(inode);
	263	return NULL;
	264	}
	265	inode->i_uid = current->fsuid;
	266	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	267	inode->i_ino = j;
	268	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
ba52de12	269	inode->i_blocks = 0;
1da177e4 LT	270	memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
	271	insert_inode_hash(inode);
	272	mark_inode_dirty(inode);
	273
	274	*error = 0;
	275	return inode;
	276	}
	277
	278	unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
	279	{
	280	return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
	281	}